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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Simplified MAC Kernel (smack) security module
4 *
5 * This file contains the smack hook function implementations.
6 *
7 * Authors:
8 * Casey Schaufler <casey@schaufler-ca.com>
9 * Jarkko Sakkinen <jarkko.sakkinen@intel.com>
10 *
11 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
12 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
13 * Paul Moore <paul@paul-moore.com>
14 * Copyright (C) 2010 Nokia Corporation
15 * Copyright (C) 2011 Intel Corporation.
16 */
17
18#include <linux/xattr.h>
19#include <linux/pagemap.h>
20#include <linux/mount.h>
21#include <linux/stat.h>
22#include <linux/kd.h>
23#include <asm/ioctls.h>
24#include <linux/ip.h>
25#include <linux/tcp.h>
26#include <linux/udp.h>
27#include <linux/dccp.h>
28#include <linux/icmpv6.h>
29#include <linux/slab.h>
30#include <linux/mutex.h>
31#include <net/cipso_ipv4.h>
32#include <net/ip.h>
33#include <net/ipv6.h>
34#include <linux/audit.h>
35#include <linux/magic.h>
36#include <linux/dcache.h>
37#include <linux/personality.h>
38#include <linux/msg.h>
39#include <linux/shm.h>
40#include <linux/binfmts.h>
41#include <linux/parser.h>
42#include <linux/fs_context.h>
43#include <linux/fs_parser.h>
44#include <linux/watch_queue.h>
45#include <linux/io_uring.h>
46#include "smack.h"
47
48#define TRANS_TRUE "TRUE"
49#define TRANS_TRUE_SIZE 4
50
51#define SMK_CONNECTING 0
52#define SMK_RECEIVING 1
53#define SMK_SENDING 2
54
55#ifdef SMACK_IPV6_PORT_LABELING
56static DEFINE_MUTEX(smack_ipv6_lock);
57static LIST_HEAD(smk_ipv6_port_list);
58#endif
59struct kmem_cache *smack_rule_cache;
60int smack_enabled __initdata;
61
62#define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
63static struct {
64 const char *name;
65 int len;
66 int opt;
67} smk_mount_opts[] = {
68 {"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault},
69 A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute)
70};
71#undef A
72
73static int match_opt_prefix(char *s, int l, char **arg)
74{
75 int i;
76
77 for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) {
78 size_t len = smk_mount_opts[i].len;
79 if (len > l || memcmp(s, smk_mount_opts[i].name, len))
80 continue;
81 if (len == l || s[len] != '=')
82 continue;
83 *arg = s + len + 1;
84 return smk_mount_opts[i].opt;
85 }
86 return Opt_error;
87}
88
89#ifdef CONFIG_SECURITY_SMACK_BRINGUP
90static char *smk_bu_mess[] = {
91 "Bringup Error", /* Unused */
92 "Bringup", /* SMACK_BRINGUP_ALLOW */
93 "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */
94 "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */
95};
96
97static void smk_bu_mode(int mode, char *s)
98{
99 int i = 0;
100
101 if (mode & MAY_READ)
102 s[i++] = 'r';
103 if (mode & MAY_WRITE)
104 s[i++] = 'w';
105 if (mode & MAY_EXEC)
106 s[i++] = 'x';
107 if (mode & MAY_APPEND)
108 s[i++] = 'a';
109 if (mode & MAY_TRANSMUTE)
110 s[i++] = 't';
111 if (mode & MAY_LOCK)
112 s[i++] = 'l';
113 if (i == 0)
114 s[i++] = '-';
115 s[i] = '\0';
116}
117#endif
118
119#ifdef CONFIG_SECURITY_SMACK_BRINGUP
120static int smk_bu_note(char *note, struct smack_known *sskp,
121 struct smack_known *oskp, int mode, int rc)
122{
123 char acc[SMK_NUM_ACCESS_TYPE + 1];
124
125 if (rc <= 0)
126 return rc;
127 if (rc > SMACK_UNCONFINED_OBJECT)
128 rc = 0;
129
130 smk_bu_mode(mode, acc);
131 pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
132 sskp->smk_known, oskp->smk_known, acc, note);
133 return 0;
134}
135#else
136#define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
137#endif
138
139#ifdef CONFIG_SECURITY_SMACK_BRINGUP
140static int smk_bu_current(char *note, struct smack_known *oskp,
141 int mode, int rc)
142{
143 struct task_smack *tsp = smack_cred(current_cred());
144 char acc[SMK_NUM_ACCESS_TYPE + 1];
145
146 if (rc <= 0)
147 return rc;
148 if (rc > SMACK_UNCONFINED_OBJECT)
149 rc = 0;
150
151 smk_bu_mode(mode, acc);
152 pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
153 tsp->smk_task->smk_known, oskp->smk_known,
154 acc, current->comm, note);
155 return 0;
156}
157#else
158#define smk_bu_current(note, oskp, mode, RC) (RC)
159#endif
160
161#ifdef CONFIG_SECURITY_SMACK_BRINGUP
162static int smk_bu_task(struct task_struct *otp, int mode, int rc)
163{
164 struct task_smack *tsp = smack_cred(current_cred());
165 struct smack_known *smk_task = smk_of_task_struct_obj(otp);
166 char acc[SMK_NUM_ACCESS_TYPE + 1];
167
168 if (rc <= 0)
169 return rc;
170 if (rc > SMACK_UNCONFINED_OBJECT)
171 rc = 0;
172
173 smk_bu_mode(mode, acc);
174 pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
175 tsp->smk_task->smk_known, smk_task->smk_known, acc,
176 current->comm, otp->comm);
177 return 0;
178}
179#else
180#define smk_bu_task(otp, mode, RC) (RC)
181#endif
182
183#ifdef CONFIG_SECURITY_SMACK_BRINGUP
184static int smk_bu_inode(struct inode *inode, int mode, int rc)
185{
186 struct task_smack *tsp = smack_cred(current_cred());
187 struct inode_smack *isp = smack_inode(inode);
188 char acc[SMK_NUM_ACCESS_TYPE + 1];
189
190 if (isp->smk_flags & SMK_INODE_IMPURE)
191 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
192 inode->i_sb->s_id, inode->i_ino, current->comm);
193
194 if (rc <= 0)
195 return rc;
196 if (rc > SMACK_UNCONFINED_OBJECT)
197 rc = 0;
198 if (rc == SMACK_UNCONFINED_SUBJECT &&
199 (mode & (MAY_WRITE | MAY_APPEND)))
200 isp->smk_flags |= SMK_INODE_IMPURE;
201
202 smk_bu_mode(mode, acc);
203
204 pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
205 tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
206 inode->i_sb->s_id, inode->i_ino, current->comm);
207 return 0;
208}
209#else
210#define smk_bu_inode(inode, mode, RC) (RC)
211#endif
212
213#ifdef CONFIG_SECURITY_SMACK_BRINGUP
214static int smk_bu_file(struct file *file, int mode, int rc)
215{
216 struct task_smack *tsp = smack_cred(current_cred());
217 struct smack_known *sskp = tsp->smk_task;
218 struct inode *inode = file_inode(file);
219 struct inode_smack *isp = smack_inode(inode);
220 char acc[SMK_NUM_ACCESS_TYPE + 1];
221
222 if (isp->smk_flags & SMK_INODE_IMPURE)
223 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
224 inode->i_sb->s_id, inode->i_ino, current->comm);
225
226 if (rc <= 0)
227 return rc;
228 if (rc > SMACK_UNCONFINED_OBJECT)
229 rc = 0;
230
231 smk_bu_mode(mode, acc);
232 pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
233 sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
234 inode->i_sb->s_id, inode->i_ino, file,
235 current->comm);
236 return 0;
237}
238#else
239#define smk_bu_file(file, mode, RC) (RC)
240#endif
241
242#ifdef CONFIG_SECURITY_SMACK_BRINGUP
243static int smk_bu_credfile(const struct cred *cred, struct file *file,
244 int mode, int rc)
245{
246 struct task_smack *tsp = smack_cred(cred);
247 struct smack_known *sskp = tsp->smk_task;
248 struct inode *inode = file_inode(file);
249 struct inode_smack *isp = smack_inode(inode);
250 char acc[SMK_NUM_ACCESS_TYPE + 1];
251
252 if (isp->smk_flags & SMK_INODE_IMPURE)
253 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
254 inode->i_sb->s_id, inode->i_ino, current->comm);
255
256 if (rc <= 0)
257 return rc;
258 if (rc > SMACK_UNCONFINED_OBJECT)
259 rc = 0;
260
261 smk_bu_mode(mode, acc);
262 pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
263 sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
264 inode->i_sb->s_id, inode->i_ino, file,
265 current->comm);
266 return 0;
267}
268#else
269#define smk_bu_credfile(cred, file, mode, RC) (RC)
270#endif
271
272/**
273 * smk_fetch - Fetch the smack label from a file.
274 * @name: type of the label (attribute)
275 * @ip: a pointer to the inode
276 * @dp: a pointer to the dentry
277 *
278 * Returns a pointer to the master list entry for the Smack label,
279 * NULL if there was no label to fetch, or an error code.
280 */
281static struct smack_known *smk_fetch(const char *name, struct inode *ip,
282 struct dentry *dp)
283{
284 int rc;
285 char *buffer;
286 struct smack_known *skp = NULL;
287
288 if (!(ip->i_opflags & IOP_XATTR))
289 return ERR_PTR(-EOPNOTSUPP);
290
291 buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS);
292 if (buffer == NULL)
293 return ERR_PTR(-ENOMEM);
294
295 rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
296 if (rc < 0)
297 skp = ERR_PTR(rc);
298 else if (rc == 0)
299 skp = NULL;
300 else
301 skp = smk_import_entry(buffer, rc);
302
303 kfree(buffer);
304
305 return skp;
306}
307
308/**
309 * init_inode_smack - initialize an inode security blob
310 * @inode: inode to extract the info from
311 * @skp: a pointer to the Smack label entry to use in the blob
312 *
313 */
314static void init_inode_smack(struct inode *inode, struct smack_known *skp)
315{
316 struct inode_smack *isp = smack_inode(inode);
317
318 isp->smk_inode = skp;
319 isp->smk_flags = 0;
320}
321
322/**
323 * init_task_smack - initialize a task security blob
324 * @tsp: blob to initialize
325 * @task: a pointer to the Smack label for the running task
326 * @forked: a pointer to the Smack label for the forked task
327 *
328 */
329static void init_task_smack(struct task_smack *tsp, struct smack_known *task,
330 struct smack_known *forked)
331{
332 tsp->smk_task = task;
333 tsp->smk_forked = forked;
334 INIT_LIST_HEAD(&tsp->smk_rules);
335 INIT_LIST_HEAD(&tsp->smk_relabel);
336 mutex_init(&tsp->smk_rules_lock);
337}
338
339/**
340 * smk_copy_rules - copy a rule set
341 * @nhead: new rules header pointer
342 * @ohead: old rules header pointer
343 * @gfp: type of the memory for the allocation
344 *
345 * Returns 0 on success, -ENOMEM on error
346 */
347static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
348 gfp_t gfp)
349{
350 struct smack_rule *nrp;
351 struct smack_rule *orp;
352 int rc = 0;
353
354 list_for_each_entry_rcu(orp, ohead, list) {
355 nrp = kmem_cache_zalloc(smack_rule_cache, gfp);
356 if (nrp == NULL) {
357 rc = -ENOMEM;
358 break;
359 }
360 *nrp = *orp;
361 list_add_rcu(&nrp->list, nhead);
362 }
363 return rc;
364}
365
366/**
367 * smk_copy_relabel - copy smk_relabel labels list
368 * @nhead: new rules header pointer
369 * @ohead: old rules header pointer
370 * @gfp: type of the memory for the allocation
371 *
372 * Returns 0 on success, -ENOMEM on error
373 */
374static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
375 gfp_t gfp)
376{
377 struct smack_known_list_elem *nklep;
378 struct smack_known_list_elem *oklep;
379
380 list_for_each_entry(oklep, ohead, list) {
381 nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
382 if (nklep == NULL) {
383 smk_destroy_label_list(nhead);
384 return -ENOMEM;
385 }
386 nklep->smk_label = oklep->smk_label;
387 list_add(&nklep->list, nhead);
388 }
389
390 return 0;
391}
392
393/**
394 * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
395 * @mode: input mode in form of PTRACE_MODE_*
396 *
397 * Returns a converted MAY_* mode usable by smack rules
398 */
399static inline unsigned int smk_ptrace_mode(unsigned int mode)
400{
401 if (mode & PTRACE_MODE_ATTACH)
402 return MAY_READWRITE;
403 if (mode & PTRACE_MODE_READ)
404 return MAY_READ;
405
406 return 0;
407}
408
409/**
410 * smk_ptrace_rule_check - helper for ptrace access
411 * @tracer: tracer process
412 * @tracee_known: label entry of the process that's about to be traced
413 * @mode: ptrace attachment mode (PTRACE_MODE_*)
414 * @func: name of the function that called us, used for audit
415 *
416 * Returns 0 on access granted, -error on error
417 */
418static int smk_ptrace_rule_check(struct task_struct *tracer,
419 struct smack_known *tracee_known,
420 unsigned int mode, const char *func)
421{
422 int rc;
423 struct smk_audit_info ad, *saip = NULL;
424 struct task_smack *tsp;
425 struct smack_known *tracer_known;
426 const struct cred *tracercred;
427
428 if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
429 smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
430 smk_ad_setfield_u_tsk(&ad, tracer);
431 saip = &ad;
432 }
433
434 rcu_read_lock();
435 tracercred = __task_cred(tracer);
436 tsp = smack_cred(tracercred);
437 tracer_known = smk_of_task(tsp);
438
439 if ((mode & PTRACE_MODE_ATTACH) &&
440 (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
441 smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
442 if (tracer_known->smk_known == tracee_known->smk_known)
443 rc = 0;
444 else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
445 rc = -EACCES;
446 else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred))
447 rc = 0;
448 else
449 rc = -EACCES;
450
451 if (saip)
452 smack_log(tracer_known->smk_known,
453 tracee_known->smk_known,
454 0, rc, saip);
455
456 rcu_read_unlock();
457 return rc;
458 }
459
460 /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
461 rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
462
463 rcu_read_unlock();
464 return rc;
465}
466
467/*
468 * LSM hooks.
469 * We he, that is fun!
470 */
471
472/**
473 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
474 * @ctp: child task pointer
475 * @mode: ptrace attachment mode (PTRACE_MODE_*)
476 *
477 * Returns 0 if access is OK, an error code otherwise
478 *
479 * Do the capability checks.
480 */
481static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
482{
483 struct smack_known *skp;
484
485 skp = smk_of_task_struct_obj(ctp);
486
487 return smk_ptrace_rule_check(current, skp, mode, __func__);
488}
489
490/**
491 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
492 * @ptp: parent task pointer
493 *
494 * Returns 0 if access is OK, an error code otherwise
495 *
496 * Do the capability checks, and require PTRACE_MODE_ATTACH.
497 */
498static int smack_ptrace_traceme(struct task_struct *ptp)
499{
500 struct smack_known *skp;
501
502 skp = smk_of_task(smack_cred(current_cred()));
503
504 return smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
505}
506
507/**
508 * smack_syslog - Smack approval on syslog
509 * @typefrom_file: unused
510 *
511 * Returns 0 on success, error code otherwise.
512 */
513static int smack_syslog(int typefrom_file)
514{
515 int rc = 0;
516 struct smack_known *skp = smk_of_current();
517
518 if (smack_privileged(CAP_MAC_OVERRIDE))
519 return 0;
520
521 if (smack_syslog_label != NULL && smack_syslog_label != skp)
522 rc = -EACCES;
523
524 return rc;
525}
526
527/*
528 * Superblock Hooks.
529 */
530
531/**
532 * smack_sb_alloc_security - allocate a superblock blob
533 * @sb: the superblock getting the blob
534 *
535 * Returns 0 on success or -ENOMEM on error.
536 */
537static int smack_sb_alloc_security(struct super_block *sb)
538{
539 struct superblock_smack *sbsp = smack_superblock(sb);
540
541 sbsp->smk_root = &smack_known_floor;
542 sbsp->smk_default = &smack_known_floor;
543 sbsp->smk_floor = &smack_known_floor;
544 sbsp->smk_hat = &smack_known_hat;
545 /*
546 * SMK_SB_INITIALIZED will be zero from kzalloc.
547 */
548
549 return 0;
550}
551
552struct smack_mnt_opts {
553 const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute;
554};
555
556static void smack_free_mnt_opts(void *mnt_opts)
557{
558 struct smack_mnt_opts *opts = mnt_opts;
559 kfree(opts->fsdefault);
560 kfree(opts->fsfloor);
561 kfree(opts->fshat);
562 kfree(opts->fsroot);
563 kfree(opts->fstransmute);
564 kfree(opts);
565}
566
567static int smack_add_opt(int token, const char *s, void **mnt_opts)
568{
569 struct smack_mnt_opts *opts = *mnt_opts;
570
571 if (!opts) {
572 opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
573 if (!opts)
574 return -ENOMEM;
575 *mnt_opts = opts;
576 }
577 if (!s)
578 return -ENOMEM;
579
580 switch (token) {
581 case Opt_fsdefault:
582 if (opts->fsdefault)
583 goto out_opt_err;
584 opts->fsdefault = s;
585 break;
586 case Opt_fsfloor:
587 if (opts->fsfloor)
588 goto out_opt_err;
589 opts->fsfloor = s;
590 break;
591 case Opt_fshat:
592 if (opts->fshat)
593 goto out_opt_err;
594 opts->fshat = s;
595 break;
596 case Opt_fsroot:
597 if (opts->fsroot)
598 goto out_opt_err;
599 opts->fsroot = s;
600 break;
601 case Opt_fstransmute:
602 if (opts->fstransmute)
603 goto out_opt_err;
604 opts->fstransmute = s;
605 break;
606 }
607 return 0;
608
609out_opt_err:
610 pr_warn("Smack: duplicate mount options\n");
611 return -EINVAL;
612}
613
614/**
615 * smack_fs_context_dup - Duplicate the security data on fs_context duplication
616 * @fc: The new filesystem context.
617 * @src_fc: The source filesystem context being duplicated.
618 *
619 * Returns 0 on success or -ENOMEM on error.
620 */
621static int smack_fs_context_dup(struct fs_context *fc,
622 struct fs_context *src_fc)
623{
624 struct smack_mnt_opts *dst, *src = src_fc->security;
625
626 if (!src)
627 return 0;
628
629 fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
630 if (!fc->security)
631 return -ENOMEM;
632 dst = fc->security;
633
634 if (src->fsdefault) {
635 dst->fsdefault = kstrdup(src->fsdefault, GFP_KERNEL);
636 if (!dst->fsdefault)
637 return -ENOMEM;
638 }
639 if (src->fsfloor) {
640 dst->fsfloor = kstrdup(src->fsfloor, GFP_KERNEL);
641 if (!dst->fsfloor)
642 return -ENOMEM;
643 }
644 if (src->fshat) {
645 dst->fshat = kstrdup(src->fshat, GFP_KERNEL);
646 if (!dst->fshat)
647 return -ENOMEM;
648 }
649 if (src->fsroot) {
650 dst->fsroot = kstrdup(src->fsroot, GFP_KERNEL);
651 if (!dst->fsroot)
652 return -ENOMEM;
653 }
654 if (src->fstransmute) {
655 dst->fstransmute = kstrdup(src->fstransmute, GFP_KERNEL);
656 if (!dst->fstransmute)
657 return -ENOMEM;
658 }
659 return 0;
660}
661
662static const struct fs_parameter_spec smack_fs_parameters[] = {
663 fsparam_string("smackfsdef", Opt_fsdefault),
664 fsparam_string("smackfsdefault", Opt_fsdefault),
665 fsparam_string("smackfsfloor", Opt_fsfloor),
666 fsparam_string("smackfshat", Opt_fshat),
667 fsparam_string("smackfsroot", Opt_fsroot),
668 fsparam_string("smackfstransmute", Opt_fstransmute),
669 {}
670};
671
672/**
673 * smack_fs_context_parse_param - Parse a single mount parameter
674 * @fc: The new filesystem context being constructed.
675 * @param: The parameter.
676 *
677 * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on
678 * error.
679 */
680static int smack_fs_context_parse_param(struct fs_context *fc,
681 struct fs_parameter *param)
682{
683 struct fs_parse_result result;
684 int opt, rc;
685
686 opt = fs_parse(fc, smack_fs_parameters, param, &result);
687 if (opt < 0)
688 return opt;
689
690 rc = smack_add_opt(opt, param->string, &fc->security);
691 if (!rc)
692 param->string = NULL;
693 return rc;
694}
695
696static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
697{
698 char *from = options, *to = options;
699 bool first = true;
700
701 while (1) {
702 char *next = strchr(from, ',');
703 int token, len, rc;
704 char *arg = NULL;
705
706 if (next)
707 len = next - from;
708 else
709 len = strlen(from);
710
711 token = match_opt_prefix(from, len, &arg);
712 if (token != Opt_error) {
713 arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
714 rc = smack_add_opt(token, arg, mnt_opts);
715 if (unlikely(rc)) {
716 kfree(arg);
717 if (*mnt_opts)
718 smack_free_mnt_opts(*mnt_opts);
719 *mnt_opts = NULL;
720 return rc;
721 }
722 } else {
723 if (!first) { // copy with preceding comma
724 from--;
725 len++;
726 }
727 if (to != from)
728 memmove(to, from, len);
729 to += len;
730 first = false;
731 }
732 if (!from[len])
733 break;
734 from += len + 1;
735 }
736 *to = '\0';
737 return 0;
738}
739
740/**
741 * smack_set_mnt_opts - set Smack specific mount options
742 * @sb: the file system superblock
743 * @mnt_opts: Smack mount options
744 * @kern_flags: mount option from kernel space or user space
745 * @set_kern_flags: where to store converted mount opts
746 *
747 * Returns 0 on success, an error code on failure
748 *
749 * Allow filesystems with binary mount data to explicitly set Smack mount
750 * labels.
751 */
752static int smack_set_mnt_opts(struct super_block *sb,
753 void *mnt_opts,
754 unsigned long kern_flags,
755 unsigned long *set_kern_flags)
756{
757 struct dentry *root = sb->s_root;
758 struct inode *inode = d_backing_inode(root);
759 struct superblock_smack *sp = smack_superblock(sb);
760 struct inode_smack *isp;
761 struct smack_known *skp;
762 struct smack_mnt_opts *opts = mnt_opts;
763 bool transmute = false;
764
765 if (sp->smk_flags & SMK_SB_INITIALIZED)
766 return 0;
767
768 if (!smack_privileged(CAP_MAC_ADMIN)) {
769 /*
770 * Unprivileged mounts don't get to specify Smack values.
771 */
772 if (opts)
773 return -EPERM;
774 /*
775 * Unprivileged mounts get root and default from the caller.
776 */
777 skp = smk_of_current();
778 sp->smk_root = skp;
779 sp->smk_default = skp;
780 /*
781 * For a handful of fs types with no user-controlled
782 * backing store it's okay to trust security labels
783 * in the filesystem. The rest are untrusted.
784 */
785 if (sb->s_user_ns != &init_user_ns &&
786 sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
787 sb->s_magic != RAMFS_MAGIC) {
788 transmute = true;
789 sp->smk_flags |= SMK_SB_UNTRUSTED;
790 }
791 }
792
793 sp->smk_flags |= SMK_SB_INITIALIZED;
794
795 if (opts) {
796 if (opts->fsdefault) {
797 skp = smk_import_entry(opts->fsdefault, 0);
798 if (IS_ERR(skp))
799 return PTR_ERR(skp);
800 sp->smk_default = skp;
801 }
802 if (opts->fsfloor) {
803 skp = smk_import_entry(opts->fsfloor, 0);
804 if (IS_ERR(skp))
805 return PTR_ERR(skp);
806 sp->smk_floor = skp;
807 }
808 if (opts->fshat) {
809 skp = smk_import_entry(opts->fshat, 0);
810 if (IS_ERR(skp))
811 return PTR_ERR(skp);
812 sp->smk_hat = skp;
813 }
814 if (opts->fsroot) {
815 skp = smk_import_entry(opts->fsroot, 0);
816 if (IS_ERR(skp))
817 return PTR_ERR(skp);
818 sp->smk_root = skp;
819 }
820 if (opts->fstransmute) {
821 skp = smk_import_entry(opts->fstransmute, 0);
822 if (IS_ERR(skp))
823 return PTR_ERR(skp);
824 sp->smk_root = skp;
825 transmute = true;
826 }
827 }
828
829 /*
830 * Initialize the root inode.
831 */
832 init_inode_smack(inode, sp->smk_root);
833
834 if (transmute) {
835 isp = smack_inode(inode);
836 isp->smk_flags |= SMK_INODE_TRANSMUTE;
837 }
838
839 return 0;
840}
841
842/**
843 * smack_sb_statfs - Smack check on statfs
844 * @dentry: identifies the file system in question
845 *
846 * Returns 0 if current can read the floor of the filesystem,
847 * and error code otherwise
848 */
849static int smack_sb_statfs(struct dentry *dentry)
850{
851 struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
852 int rc;
853 struct smk_audit_info ad;
854
855 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
856 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
857
858 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
859 rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
860 return rc;
861}
862
863/*
864 * BPRM hooks
865 */
866
867/**
868 * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec
869 * @bprm: the exec information
870 *
871 * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
872 */
873static int smack_bprm_creds_for_exec(struct linux_binprm *bprm)
874{
875 struct inode *inode = file_inode(bprm->file);
876 struct task_smack *bsp = smack_cred(bprm->cred);
877 struct inode_smack *isp;
878 struct superblock_smack *sbsp;
879 int rc;
880
881 isp = smack_inode(inode);
882 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
883 return 0;
884
885 sbsp = smack_superblock(inode->i_sb);
886 if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
887 isp->smk_task != sbsp->smk_root)
888 return 0;
889
890 if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
891 struct task_struct *tracer;
892 rc = 0;
893
894 rcu_read_lock();
895 tracer = ptrace_parent(current);
896 if (likely(tracer != NULL))
897 rc = smk_ptrace_rule_check(tracer,
898 isp->smk_task,
899 PTRACE_MODE_ATTACH,
900 __func__);
901 rcu_read_unlock();
902
903 if (rc != 0)
904 return rc;
905 }
906 if (bprm->unsafe & ~LSM_UNSAFE_PTRACE)
907 return -EPERM;
908
909 bsp->smk_task = isp->smk_task;
910 bprm->per_clear |= PER_CLEAR_ON_SETID;
911
912 /* Decide if this is a secure exec. */
913 if (bsp->smk_task != bsp->smk_forked)
914 bprm->secureexec = 1;
915
916 return 0;
917}
918
919/*
920 * Inode hooks
921 */
922
923/**
924 * smack_inode_alloc_security - allocate an inode blob
925 * @inode: the inode in need of a blob
926 *
927 * Returns 0
928 */
929static int smack_inode_alloc_security(struct inode *inode)
930{
931 struct smack_known *skp = smk_of_current();
932
933 init_inode_smack(inode, skp);
934 return 0;
935}
936
937/**
938 * smack_inode_init_security - copy out the smack from an inode
939 * @inode: the newly created inode
940 * @dir: containing directory object
941 * @qstr: unused
942 * @name: where to put the attribute name
943 * @value: where to put the attribute value
944 * @len: where to put the length of the attribute
945 *
946 * Returns 0 if it all works out, -ENOMEM if there's no memory
947 */
948static int smack_inode_init_security(struct inode *inode, struct inode *dir,
949 const struct qstr *qstr, const char **name,
950 void **value, size_t *len)
951{
952 struct inode_smack *issp = smack_inode(inode);
953 struct smack_known *skp = smk_of_current();
954 struct smack_known *isp = smk_of_inode(inode);
955 struct smack_known *dsp = smk_of_inode(dir);
956 int may;
957
958 if (name)
959 *name = XATTR_SMACK_SUFFIX;
960
961 if (value && len) {
962 rcu_read_lock();
963 may = smk_access_entry(skp->smk_known, dsp->smk_known,
964 &skp->smk_rules);
965 rcu_read_unlock();
966
967 /*
968 * If the access rule allows transmutation and
969 * the directory requests transmutation then
970 * by all means transmute.
971 * Mark the inode as changed.
972 */
973 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
974 smk_inode_transmutable(dir)) {
975 isp = dsp;
976 issp->smk_flags |= SMK_INODE_CHANGED;
977 }
978
979 *value = kstrdup(isp->smk_known, GFP_NOFS);
980 if (*value == NULL)
981 return -ENOMEM;
982
983 *len = strlen(isp->smk_known);
984 }
985
986 return 0;
987}
988
989/**
990 * smack_inode_link - Smack check on link
991 * @old_dentry: the existing object
992 * @dir: unused
993 * @new_dentry: the new object
994 *
995 * Returns 0 if access is permitted, an error code otherwise
996 */
997static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
998 struct dentry *new_dentry)
999{
1000 struct smack_known *isp;
1001 struct smk_audit_info ad;
1002 int rc;
1003
1004 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1005 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1006
1007 isp = smk_of_inode(d_backing_inode(old_dentry));
1008 rc = smk_curacc(isp, MAY_WRITE, &ad);
1009 rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
1010
1011 if (rc == 0 && d_is_positive(new_dentry)) {
1012 isp = smk_of_inode(d_backing_inode(new_dentry));
1013 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1014 rc = smk_curacc(isp, MAY_WRITE, &ad);
1015 rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
1016 }
1017
1018 return rc;
1019}
1020
1021/**
1022 * smack_inode_unlink - Smack check on inode deletion
1023 * @dir: containing directory object
1024 * @dentry: file to unlink
1025 *
1026 * Returns 0 if current can write the containing directory
1027 * and the object, error code otherwise
1028 */
1029static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
1030{
1031 struct inode *ip = d_backing_inode(dentry);
1032 struct smk_audit_info ad;
1033 int rc;
1034
1035 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1036 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1037
1038 /*
1039 * You need write access to the thing you're unlinking
1040 */
1041 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
1042 rc = smk_bu_inode(ip, MAY_WRITE, rc);
1043 if (rc == 0) {
1044 /*
1045 * You also need write access to the containing directory
1046 */
1047 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1048 smk_ad_setfield_u_fs_inode(&ad, dir);
1049 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1050 rc = smk_bu_inode(dir, MAY_WRITE, rc);
1051 }
1052 return rc;
1053}
1054
1055/**
1056 * smack_inode_rmdir - Smack check on directory deletion
1057 * @dir: containing directory object
1058 * @dentry: directory to unlink
1059 *
1060 * Returns 0 if current can write the containing directory
1061 * and the directory, error code otherwise
1062 */
1063static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
1064{
1065 struct smk_audit_info ad;
1066 int rc;
1067
1068 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1069 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1070
1071 /*
1072 * You need write access to the thing you're removing
1073 */
1074 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1075 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1076 if (rc == 0) {
1077 /*
1078 * You also need write access to the containing directory
1079 */
1080 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1081 smk_ad_setfield_u_fs_inode(&ad, dir);
1082 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1083 rc = smk_bu_inode(dir, MAY_WRITE, rc);
1084 }
1085
1086 return rc;
1087}
1088
1089/**
1090 * smack_inode_rename - Smack check on rename
1091 * @old_inode: unused
1092 * @old_dentry: the old object
1093 * @new_inode: unused
1094 * @new_dentry: the new object
1095 *
1096 * Read and write access is required on both the old and
1097 * new directories.
1098 *
1099 * Returns 0 if access is permitted, an error code otherwise
1100 */
1101static int smack_inode_rename(struct inode *old_inode,
1102 struct dentry *old_dentry,
1103 struct inode *new_inode,
1104 struct dentry *new_dentry)
1105{
1106 int rc;
1107 struct smack_known *isp;
1108 struct smk_audit_info ad;
1109
1110 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1111 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1112
1113 isp = smk_of_inode(d_backing_inode(old_dentry));
1114 rc = smk_curacc(isp, MAY_READWRITE, &ad);
1115 rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
1116
1117 if (rc == 0 && d_is_positive(new_dentry)) {
1118 isp = smk_of_inode(d_backing_inode(new_dentry));
1119 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1120 rc = smk_curacc(isp, MAY_READWRITE, &ad);
1121 rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
1122 }
1123 return rc;
1124}
1125
1126/**
1127 * smack_inode_permission - Smack version of permission()
1128 * @inode: the inode in question
1129 * @mask: the access requested
1130 *
1131 * This is the important Smack hook.
1132 *
1133 * Returns 0 if access is permitted, an error code otherwise
1134 */
1135static int smack_inode_permission(struct inode *inode, int mask)
1136{
1137 struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
1138 struct smk_audit_info ad;
1139 int no_block = mask & MAY_NOT_BLOCK;
1140 int rc;
1141
1142 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
1143 /*
1144 * No permission to check. Existence test. Yup, it's there.
1145 */
1146 if (mask == 0)
1147 return 0;
1148
1149 if (sbsp->smk_flags & SMK_SB_UNTRUSTED) {
1150 if (smk_of_inode(inode) != sbsp->smk_root)
1151 return -EACCES;
1152 }
1153
1154 /* May be droppable after audit */
1155 if (no_block)
1156 return -ECHILD;
1157 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1158 smk_ad_setfield_u_fs_inode(&ad, inode);
1159 rc = smk_curacc(smk_of_inode(inode), mask, &ad);
1160 rc = smk_bu_inode(inode, mask, rc);
1161 return rc;
1162}
1163
1164/**
1165 * smack_inode_setattr - Smack check for setting attributes
1166 * @dentry: the object
1167 * @iattr: for the force flag
1168 *
1169 * Returns 0 if access is permitted, an error code otherwise
1170 */
1171static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
1172{
1173 struct smk_audit_info ad;
1174 int rc;
1175
1176 /*
1177 * Need to allow for clearing the setuid bit.
1178 */
1179 if (iattr->ia_valid & ATTR_FORCE)
1180 return 0;
1181 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1182 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1183
1184 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1185 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1186 return rc;
1187}
1188
1189/**
1190 * smack_inode_getattr - Smack check for getting attributes
1191 * @path: path to extract the info from
1192 *
1193 * Returns 0 if access is permitted, an error code otherwise
1194 */
1195static int smack_inode_getattr(const struct path *path)
1196{
1197 struct smk_audit_info ad;
1198 struct inode *inode = d_backing_inode(path->dentry);
1199 int rc;
1200
1201 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1202 smk_ad_setfield_u_fs_path(&ad, *path);
1203 rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1204 rc = smk_bu_inode(inode, MAY_READ, rc);
1205 return rc;
1206}
1207
1208/**
1209 * smack_inode_setxattr - Smack check for setting xattrs
1210 * @mnt_userns: active user namespace
1211 * @dentry: the object
1212 * @name: name of the attribute
1213 * @value: value of the attribute
1214 * @size: size of the value
1215 * @flags: unused
1216 *
1217 * This protects the Smack attribute explicitly.
1218 *
1219 * Returns 0 if access is permitted, an error code otherwise
1220 */
1221static int smack_inode_setxattr(struct user_namespace *mnt_userns,
1222 struct dentry *dentry, const char *name,
1223 const void *value, size_t size, int flags)
1224{
1225 struct smk_audit_info ad;
1226 struct smack_known *skp;
1227 int check_priv = 0;
1228 int check_import = 0;
1229 int check_star = 0;
1230 int rc = 0;
1231
1232 /*
1233 * Check label validity here so import won't fail in post_setxattr
1234 */
1235 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1236 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1237 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
1238 check_priv = 1;
1239 check_import = 1;
1240 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1241 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1242 check_priv = 1;
1243 check_import = 1;
1244 check_star = 1;
1245 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1246 check_priv = 1;
1247 if (size != TRANS_TRUE_SIZE ||
1248 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
1249 rc = -EINVAL;
1250 } else
1251 rc = cap_inode_setxattr(dentry, name, value, size, flags);
1252
1253 if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
1254 rc = -EPERM;
1255
1256 if (rc == 0 && check_import) {
1257 skp = size ? smk_import_entry(value, size) : NULL;
1258 if (IS_ERR(skp))
1259 rc = PTR_ERR(skp);
1260 else if (skp == NULL || (check_star &&
1261 (skp == &smack_known_star || skp == &smack_known_web)))
1262 rc = -EINVAL;
1263 }
1264
1265 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1266 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1267
1268 if (rc == 0) {
1269 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1270 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1271 }
1272
1273 return rc;
1274}
1275
1276/**
1277 * smack_inode_post_setxattr - Apply the Smack update approved above
1278 * @dentry: object
1279 * @name: attribute name
1280 * @value: attribute value
1281 * @size: attribute size
1282 * @flags: unused
1283 *
1284 * Set the pointer in the inode blob to the entry found
1285 * in the master label list.
1286 */
1287static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
1288 const void *value, size_t size, int flags)
1289{
1290 struct smack_known *skp;
1291 struct inode_smack *isp = smack_inode(d_backing_inode(dentry));
1292
1293 if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1294 isp->smk_flags |= SMK_INODE_TRANSMUTE;
1295 return;
1296 }
1297
1298 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1299 skp = smk_import_entry(value, size);
1300 if (!IS_ERR(skp))
1301 isp->smk_inode = skp;
1302 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1303 skp = smk_import_entry(value, size);
1304 if (!IS_ERR(skp))
1305 isp->smk_task = skp;
1306 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1307 skp = smk_import_entry(value, size);
1308 if (!IS_ERR(skp))
1309 isp->smk_mmap = skp;
1310 }
1311
1312 return;
1313}
1314
1315/**
1316 * smack_inode_getxattr - Smack check on getxattr
1317 * @dentry: the object
1318 * @name: unused
1319 *
1320 * Returns 0 if access is permitted, an error code otherwise
1321 */
1322static int smack_inode_getxattr(struct dentry *dentry, const char *name)
1323{
1324 struct smk_audit_info ad;
1325 int rc;
1326
1327 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1328 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1329
1330 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1331 rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1332 return rc;
1333}
1334
1335/**
1336 * smack_inode_removexattr - Smack check on removexattr
1337 * @mnt_userns: active user namespace
1338 * @dentry: the object
1339 * @name: name of the attribute
1340 *
1341 * Removing the Smack attribute requires CAP_MAC_ADMIN
1342 *
1343 * Returns 0 if access is permitted, an error code otherwise
1344 */
1345static int smack_inode_removexattr(struct user_namespace *mnt_userns,
1346 struct dentry *dentry, const char *name)
1347{
1348 struct inode_smack *isp;
1349 struct smk_audit_info ad;
1350 int rc = 0;
1351
1352 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1353 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1354 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1355 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1356 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
1357 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1358 if (!smack_privileged(CAP_MAC_ADMIN))
1359 rc = -EPERM;
1360 } else
1361 rc = cap_inode_removexattr(mnt_userns, dentry, name);
1362
1363 if (rc != 0)
1364 return rc;
1365
1366 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1367 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1368
1369 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1370 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1371 if (rc != 0)
1372 return rc;
1373
1374 isp = smack_inode(d_backing_inode(dentry));
1375 /*
1376 * Don't do anything special for these.
1377 * XATTR_NAME_SMACKIPIN
1378 * XATTR_NAME_SMACKIPOUT
1379 */
1380 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1381 struct super_block *sbp = dentry->d_sb;
1382 struct superblock_smack *sbsp = smack_superblock(sbp);
1383
1384 isp->smk_inode = sbsp->smk_default;
1385 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
1386 isp->smk_task = NULL;
1387 else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1388 isp->smk_mmap = NULL;
1389 else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
1390 isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1391
1392 return 0;
1393}
1394
1395/**
1396 * smack_inode_set_acl - Smack check for setting posix acls
1397 * @mnt_userns: the userns attached to the mnt this request came from
1398 * @dentry: the object
1399 * @acl_name: name of the posix acl
1400 * @kacl: the posix acls
1401 *
1402 * Returns 0 if access is permitted, an error code otherwise
1403 */
1404static int smack_inode_set_acl(struct user_namespace *mnt_userns,
1405 struct dentry *dentry, const char *acl_name,
1406 struct posix_acl *kacl)
1407{
1408 struct smk_audit_info ad;
1409 int rc;
1410
1411 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1412 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1413
1414 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1415 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1416 return rc;
1417}
1418
1419/**
1420 * smack_inode_get_acl - Smack check for getting posix acls
1421 * @mnt_userns: the userns attached to the mnt this request came from
1422 * @dentry: the object
1423 * @acl_name: name of the posix acl
1424 *
1425 * Returns 0 if access is permitted, an error code otherwise
1426 */
1427static int smack_inode_get_acl(struct user_namespace *mnt_userns,
1428 struct dentry *dentry, const char *acl_name)
1429{
1430 struct smk_audit_info ad;
1431 int rc;
1432
1433 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1434 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1435
1436 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1437 rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1438 return rc;
1439}
1440
1441/**
1442 * smack_inode_remove_acl - Smack check for getting posix acls
1443 * @mnt_userns: the userns attached to the mnt this request came from
1444 * @dentry: the object
1445 * @acl_name: name of the posix acl
1446 *
1447 * Returns 0 if access is permitted, an error code otherwise
1448 */
1449static int smack_inode_remove_acl(struct user_namespace *mnt_userns,
1450 struct dentry *dentry, const char *acl_name)
1451{
1452 struct smk_audit_info ad;
1453 int rc;
1454
1455 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1456 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1457
1458 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1459 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1460 return rc;
1461}
1462
1463/**
1464 * smack_inode_getsecurity - get smack xattrs
1465 * @mnt_userns: active user namespace
1466 * @inode: the object
1467 * @name: attribute name
1468 * @buffer: where to put the result
1469 * @alloc: duplicate memory
1470 *
1471 * Returns the size of the attribute or an error code
1472 */
1473static int smack_inode_getsecurity(struct user_namespace *mnt_userns,
1474 struct inode *inode, const char *name,
1475 void **buffer, bool alloc)
1476{
1477 struct socket_smack *ssp;
1478 struct socket *sock;
1479 struct super_block *sbp;
1480 struct inode *ip = (struct inode *)inode;
1481 struct smack_known *isp;
1482
1483 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0)
1484 isp = smk_of_inode(inode);
1485 else {
1486 /*
1487 * The rest of the Smack xattrs are only on sockets.
1488 */
1489 sbp = ip->i_sb;
1490 if (sbp->s_magic != SOCKFS_MAGIC)
1491 return -EOPNOTSUPP;
1492
1493 sock = SOCKET_I(ip);
1494 if (sock == NULL || sock->sk == NULL)
1495 return -EOPNOTSUPP;
1496
1497 ssp = sock->sk->sk_security;
1498
1499 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1500 isp = ssp->smk_in;
1501 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1502 isp = ssp->smk_out;
1503 else
1504 return -EOPNOTSUPP;
1505 }
1506
1507 if (alloc) {
1508 *buffer = kstrdup(isp->smk_known, GFP_KERNEL);
1509 if (*buffer == NULL)
1510 return -ENOMEM;
1511 }
1512
1513 return strlen(isp->smk_known);
1514}
1515
1516
1517/**
1518 * smack_inode_listsecurity - list the Smack attributes
1519 * @inode: the object
1520 * @buffer: where they go
1521 * @buffer_size: size of buffer
1522 */
1523static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1524 size_t buffer_size)
1525{
1526 int len = sizeof(XATTR_NAME_SMACK);
1527
1528 if (buffer != NULL && len <= buffer_size)
1529 memcpy(buffer, XATTR_NAME_SMACK, len);
1530
1531 return len;
1532}
1533
1534/**
1535 * smack_inode_getsecid - Extract inode's security id
1536 * @inode: inode to extract the info from
1537 * @secid: where result will be saved
1538 */
1539static void smack_inode_getsecid(struct inode *inode, u32 *secid)
1540{
1541 struct smack_known *skp = smk_of_inode(inode);
1542
1543 *secid = skp->smk_secid;
1544}
1545
1546/*
1547 * File Hooks
1548 */
1549
1550/*
1551 * There is no smack_file_permission hook
1552 *
1553 * Should access checks be done on each read or write?
1554 * UNICOS and SELinux say yes.
1555 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1556 *
1557 * I'll say no for now. Smack does not do the frequent
1558 * label changing that SELinux does.
1559 */
1560
1561/**
1562 * smack_file_alloc_security - assign a file security blob
1563 * @file: the object
1564 *
1565 * The security blob for a file is a pointer to the master
1566 * label list, so no allocation is done.
1567 *
1568 * f_security is the owner security information. It
1569 * isn't used on file access checks, it's for send_sigio.
1570 *
1571 * Returns 0
1572 */
1573static int smack_file_alloc_security(struct file *file)
1574{
1575 struct smack_known **blob = smack_file(file);
1576
1577 *blob = smk_of_current();
1578 return 0;
1579}
1580
1581/**
1582 * smack_file_ioctl - Smack check on ioctls
1583 * @file: the object
1584 * @cmd: what to do
1585 * @arg: unused
1586 *
1587 * Relies heavily on the correct use of the ioctl command conventions.
1588 *
1589 * Returns 0 if allowed, error code otherwise
1590 */
1591static int smack_file_ioctl(struct file *file, unsigned int cmd,
1592 unsigned long arg)
1593{
1594 int rc = 0;
1595 struct smk_audit_info ad;
1596 struct inode *inode = file_inode(file);
1597
1598 if (unlikely(IS_PRIVATE(inode)))
1599 return 0;
1600
1601 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1602 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1603
1604 if (_IOC_DIR(cmd) & _IOC_WRITE) {
1605 rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1606 rc = smk_bu_file(file, MAY_WRITE, rc);
1607 }
1608
1609 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
1610 rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1611 rc = smk_bu_file(file, MAY_READ, rc);
1612 }
1613
1614 return rc;
1615}
1616
1617/**
1618 * smack_file_lock - Smack check on file locking
1619 * @file: the object
1620 * @cmd: unused
1621 *
1622 * Returns 0 if current has lock access, error code otherwise
1623 */
1624static int smack_file_lock(struct file *file, unsigned int cmd)
1625{
1626 struct smk_audit_info ad;
1627 int rc;
1628 struct inode *inode = file_inode(file);
1629
1630 if (unlikely(IS_PRIVATE(inode)))
1631 return 0;
1632
1633 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1634 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1635 rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1636 rc = smk_bu_file(file, MAY_LOCK, rc);
1637 return rc;
1638}
1639
1640/**
1641 * smack_file_fcntl - Smack check on fcntl
1642 * @file: the object
1643 * @cmd: what action to check
1644 * @arg: unused
1645 *
1646 * Generally these operations are harmless.
1647 * File locking operations present an obvious mechanism
1648 * for passing information, so they require write access.
1649 *
1650 * Returns 0 if current has access, error code otherwise
1651 */
1652static int smack_file_fcntl(struct file *file, unsigned int cmd,
1653 unsigned long arg)
1654{
1655 struct smk_audit_info ad;
1656 int rc = 0;
1657 struct inode *inode = file_inode(file);
1658
1659 if (unlikely(IS_PRIVATE(inode)))
1660 return 0;
1661
1662 switch (cmd) {
1663 case F_GETLK:
1664 break;
1665 case F_SETLK:
1666 case F_SETLKW:
1667 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1668 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1669 rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1670 rc = smk_bu_file(file, MAY_LOCK, rc);
1671 break;
1672 case F_SETOWN:
1673 case F_SETSIG:
1674 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1675 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1676 rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1677 rc = smk_bu_file(file, MAY_WRITE, rc);
1678 break;
1679 default:
1680 break;
1681 }
1682
1683 return rc;
1684}
1685
1686/**
1687 * smack_mmap_file - Check permissions for a mmap operation.
1688 * @file: contains the file structure for file to map (may be NULL).
1689 * @reqprot: contains the protection requested by the application.
1690 * @prot: contains the protection that will be applied by the kernel.
1691 * @flags: contains the operational flags.
1692 *
1693 * The @file may be NULL, e.g. if mapping anonymous memory.
1694 *
1695 * Return 0 if permission is granted.
1696 */
1697static int smack_mmap_file(struct file *file,
1698 unsigned long reqprot, unsigned long prot,
1699 unsigned long flags)
1700{
1701 struct smack_known *skp;
1702 struct smack_known *mkp;
1703 struct smack_rule *srp;
1704 struct task_smack *tsp;
1705 struct smack_known *okp;
1706 struct inode_smack *isp;
1707 struct superblock_smack *sbsp;
1708 int may;
1709 int mmay;
1710 int tmay;
1711 int rc;
1712
1713 if (file == NULL)
1714 return 0;
1715
1716 if (unlikely(IS_PRIVATE(file_inode(file))))
1717 return 0;
1718
1719 isp = smack_inode(file_inode(file));
1720 if (isp->smk_mmap == NULL)
1721 return 0;
1722 sbsp = smack_superblock(file_inode(file)->i_sb);
1723 if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
1724 isp->smk_mmap != sbsp->smk_root)
1725 return -EACCES;
1726 mkp = isp->smk_mmap;
1727
1728 tsp = smack_cred(current_cred());
1729 skp = smk_of_current();
1730 rc = 0;
1731
1732 rcu_read_lock();
1733 /*
1734 * For each Smack rule associated with the subject
1735 * label verify that the SMACK64MMAP also has access
1736 * to that rule's object label.
1737 */
1738 list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1739 okp = srp->smk_object;
1740 /*
1741 * Matching labels always allows access.
1742 */
1743 if (mkp->smk_known == okp->smk_known)
1744 continue;
1745 /*
1746 * If there is a matching local rule take
1747 * that into account as well.
1748 */
1749 may = smk_access_entry(srp->smk_subject->smk_known,
1750 okp->smk_known,
1751 &tsp->smk_rules);
1752 if (may == -ENOENT)
1753 may = srp->smk_access;
1754 else
1755 may &= srp->smk_access;
1756 /*
1757 * If may is zero the SMACK64MMAP subject can't
1758 * possibly have less access.
1759 */
1760 if (may == 0)
1761 continue;
1762
1763 /*
1764 * Fetch the global list entry.
1765 * If there isn't one a SMACK64MMAP subject
1766 * can't have as much access as current.
1767 */
1768 mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1769 &mkp->smk_rules);
1770 if (mmay == -ENOENT) {
1771 rc = -EACCES;
1772 break;
1773 }
1774 /*
1775 * If there is a local entry it modifies the
1776 * potential access, too.
1777 */
1778 tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1779 &tsp->smk_rules);
1780 if (tmay != -ENOENT)
1781 mmay &= tmay;
1782
1783 /*
1784 * If there is any access available to current that is
1785 * not available to a SMACK64MMAP subject
1786 * deny access.
1787 */
1788 if ((may | mmay) != mmay) {
1789 rc = -EACCES;
1790 break;
1791 }
1792 }
1793
1794 rcu_read_unlock();
1795
1796 return rc;
1797}
1798
1799/**
1800 * smack_file_set_fowner - set the file security blob value
1801 * @file: object in question
1802 *
1803 */
1804static void smack_file_set_fowner(struct file *file)
1805{
1806 struct smack_known **blob = smack_file(file);
1807
1808 *blob = smk_of_current();
1809}
1810
1811/**
1812 * smack_file_send_sigiotask - Smack on sigio
1813 * @tsk: The target task
1814 * @fown: the object the signal come from
1815 * @signum: unused
1816 *
1817 * Allow a privileged task to get signals even if it shouldn't
1818 *
1819 * Returns 0 if a subject with the object's smack could
1820 * write to the task, an error code otherwise.
1821 */
1822static int smack_file_send_sigiotask(struct task_struct *tsk,
1823 struct fown_struct *fown, int signum)
1824{
1825 struct smack_known **blob;
1826 struct smack_known *skp;
1827 struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred));
1828 const struct cred *tcred;
1829 struct file *file;
1830 int rc;
1831 struct smk_audit_info ad;
1832
1833 /*
1834 * struct fown_struct is never outside the context of a struct file
1835 */
1836 file = container_of(fown, struct file, f_owner);
1837
1838 /* we don't log here as rc can be overriden */
1839 blob = smack_file(file);
1840 skp = *blob;
1841 rc = smk_access(skp, tkp, MAY_DELIVER, NULL);
1842 rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc);
1843
1844 rcu_read_lock();
1845 tcred = __task_cred(tsk);
1846 if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred))
1847 rc = 0;
1848 rcu_read_unlock();
1849
1850 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1851 smk_ad_setfield_u_tsk(&ad, tsk);
1852 smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad);
1853 return rc;
1854}
1855
1856/**
1857 * smack_file_receive - Smack file receive check
1858 * @file: the object
1859 *
1860 * Returns 0 if current has access, error code otherwise
1861 */
1862static int smack_file_receive(struct file *file)
1863{
1864 int rc;
1865 int may = 0;
1866 struct smk_audit_info ad;
1867 struct inode *inode = file_inode(file);
1868 struct socket *sock;
1869 struct task_smack *tsp;
1870 struct socket_smack *ssp;
1871
1872 if (unlikely(IS_PRIVATE(inode)))
1873 return 0;
1874
1875 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1876 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1877
1878 if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
1879 sock = SOCKET_I(inode);
1880 ssp = sock->sk->sk_security;
1881 tsp = smack_cred(current_cred());
1882 /*
1883 * If the receiving process can't write to the
1884 * passed socket or if the passed socket can't
1885 * write to the receiving process don't accept
1886 * the passed socket.
1887 */
1888 rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad);
1889 rc = smk_bu_file(file, may, rc);
1890 if (rc < 0)
1891 return rc;
1892 rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad);
1893 rc = smk_bu_file(file, may, rc);
1894 return rc;
1895 }
1896 /*
1897 * This code relies on bitmasks.
1898 */
1899 if (file->f_mode & FMODE_READ)
1900 may = MAY_READ;
1901 if (file->f_mode & FMODE_WRITE)
1902 may |= MAY_WRITE;
1903
1904 rc = smk_curacc(smk_of_inode(inode), may, &ad);
1905 rc = smk_bu_file(file, may, rc);
1906 return rc;
1907}
1908
1909/**
1910 * smack_file_open - Smack dentry open processing
1911 * @file: the object
1912 *
1913 * Set the security blob in the file structure.
1914 * Allow the open only if the task has read access. There are
1915 * many read operations (e.g. fstat) that you can do with an
1916 * fd even if you have the file open write-only.
1917 *
1918 * Returns 0 if current has access, error code otherwise
1919 */
1920static int smack_file_open(struct file *file)
1921{
1922 struct task_smack *tsp = smack_cred(file->f_cred);
1923 struct inode *inode = file_inode(file);
1924 struct smk_audit_info ad;
1925 int rc;
1926
1927 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1928 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1929 rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
1930 rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
1931
1932 return rc;
1933}
1934
1935/*
1936 * Task hooks
1937 */
1938
1939/**
1940 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1941 * @cred: the new credentials
1942 * @gfp: the atomicity of any memory allocations
1943 *
1944 * Prepare a blank set of credentials for modification. This must allocate all
1945 * the memory the LSM module might require such that cred_transfer() can
1946 * complete without error.
1947 */
1948static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1949{
1950 init_task_smack(smack_cred(cred), NULL, NULL);
1951 return 0;
1952}
1953
1954
1955/**
1956 * smack_cred_free - "free" task-level security credentials
1957 * @cred: the credentials in question
1958 *
1959 */
1960static void smack_cred_free(struct cred *cred)
1961{
1962 struct task_smack *tsp = smack_cred(cred);
1963 struct smack_rule *rp;
1964 struct list_head *l;
1965 struct list_head *n;
1966
1967 smk_destroy_label_list(&tsp->smk_relabel);
1968
1969 list_for_each_safe(l, n, &tsp->smk_rules) {
1970 rp = list_entry(l, struct smack_rule, list);
1971 list_del(&rp->list);
1972 kmem_cache_free(smack_rule_cache, rp);
1973 }
1974}
1975
1976/**
1977 * smack_cred_prepare - prepare new set of credentials for modification
1978 * @new: the new credentials
1979 * @old: the original credentials
1980 * @gfp: the atomicity of any memory allocations
1981 *
1982 * Prepare a new set of credentials for modification.
1983 */
1984static int smack_cred_prepare(struct cred *new, const struct cred *old,
1985 gfp_t gfp)
1986{
1987 struct task_smack *old_tsp = smack_cred(old);
1988 struct task_smack *new_tsp = smack_cred(new);
1989 int rc;
1990
1991 init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
1992
1993 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1994 if (rc != 0)
1995 return rc;
1996
1997 rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
1998 gfp);
1999 return rc;
2000}
2001
2002/**
2003 * smack_cred_transfer - Transfer the old credentials to the new credentials
2004 * @new: the new credentials
2005 * @old: the original credentials
2006 *
2007 * Fill in a set of blank credentials from another set of credentials.
2008 */
2009static void smack_cred_transfer(struct cred *new, const struct cred *old)
2010{
2011 struct task_smack *old_tsp = smack_cred(old);
2012 struct task_smack *new_tsp = smack_cred(new);
2013
2014 new_tsp->smk_task = old_tsp->smk_task;
2015 new_tsp->smk_forked = old_tsp->smk_task;
2016 mutex_init(&new_tsp->smk_rules_lock);
2017 INIT_LIST_HEAD(&new_tsp->smk_rules);
2018
2019 /* cbs copy rule list */
2020}
2021
2022/**
2023 * smack_cred_getsecid - get the secid corresponding to a creds structure
2024 * @cred: the object creds
2025 * @secid: where to put the result
2026 *
2027 * Sets the secid to contain a u32 version of the smack label.
2028 */
2029static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
2030{
2031 struct smack_known *skp;
2032
2033 rcu_read_lock();
2034 skp = smk_of_task(smack_cred(cred));
2035 *secid = skp->smk_secid;
2036 rcu_read_unlock();
2037}
2038
2039/**
2040 * smack_kernel_act_as - Set the subjective context in a set of credentials
2041 * @new: points to the set of credentials to be modified.
2042 * @secid: specifies the security ID to be set
2043 *
2044 * Set the security data for a kernel service.
2045 */
2046static int smack_kernel_act_as(struct cred *new, u32 secid)
2047{
2048 struct task_smack *new_tsp = smack_cred(new);
2049
2050 new_tsp->smk_task = smack_from_secid(secid);
2051 return 0;
2052}
2053
2054/**
2055 * smack_kernel_create_files_as - Set the file creation label in a set of creds
2056 * @new: points to the set of credentials to be modified
2057 * @inode: points to the inode to use as a reference
2058 *
2059 * Set the file creation context in a set of credentials to the same
2060 * as the objective context of the specified inode
2061 */
2062static int smack_kernel_create_files_as(struct cred *new,
2063 struct inode *inode)
2064{
2065 struct inode_smack *isp = smack_inode(inode);
2066 struct task_smack *tsp = smack_cred(new);
2067
2068 tsp->smk_forked = isp->smk_inode;
2069 tsp->smk_task = tsp->smk_forked;
2070 return 0;
2071}
2072
2073/**
2074 * smk_curacc_on_task - helper to log task related access
2075 * @p: the task object
2076 * @access: the access requested
2077 * @caller: name of the calling function for audit
2078 *
2079 * Return 0 if access is permitted
2080 */
2081static int smk_curacc_on_task(struct task_struct *p, int access,
2082 const char *caller)
2083{
2084 struct smk_audit_info ad;
2085 struct smack_known *skp = smk_of_task_struct_obj(p);
2086 int rc;
2087
2088 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
2089 smk_ad_setfield_u_tsk(&ad, p);
2090 rc = smk_curacc(skp, access, &ad);
2091 rc = smk_bu_task(p, access, rc);
2092 return rc;
2093}
2094
2095/**
2096 * smack_task_setpgid - Smack check on setting pgid
2097 * @p: the task object
2098 * @pgid: unused
2099 *
2100 * Return 0 if write access is permitted
2101 */
2102static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
2103{
2104 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2105}
2106
2107/**
2108 * smack_task_getpgid - Smack access check for getpgid
2109 * @p: the object task
2110 *
2111 * Returns 0 if current can read the object task, error code otherwise
2112 */
2113static int smack_task_getpgid(struct task_struct *p)
2114{
2115 return smk_curacc_on_task(p, MAY_READ, __func__);
2116}
2117
2118/**
2119 * smack_task_getsid - Smack access check for getsid
2120 * @p: the object task
2121 *
2122 * Returns 0 if current can read the object task, error code otherwise
2123 */
2124static int smack_task_getsid(struct task_struct *p)
2125{
2126 return smk_curacc_on_task(p, MAY_READ, __func__);
2127}
2128
2129/**
2130 * smack_current_getsecid_subj - get the subjective secid of the current task
2131 * @secid: where to put the result
2132 *
2133 * Sets the secid to contain a u32 version of the task's subjective smack label.
2134 */
2135static void smack_current_getsecid_subj(u32 *secid)
2136{
2137 struct smack_known *skp = smk_of_current();
2138
2139 *secid = skp->smk_secid;
2140}
2141
2142/**
2143 * smack_task_getsecid_obj - get the objective secid of the task
2144 * @p: the task
2145 * @secid: where to put the result
2146 *
2147 * Sets the secid to contain a u32 version of the task's objective smack label.
2148 */
2149static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid)
2150{
2151 struct smack_known *skp = smk_of_task_struct_obj(p);
2152
2153 *secid = skp->smk_secid;
2154}
2155
2156/**
2157 * smack_task_setnice - Smack check on setting nice
2158 * @p: the task object
2159 * @nice: unused
2160 *
2161 * Return 0 if write access is permitted
2162 */
2163static int smack_task_setnice(struct task_struct *p, int nice)
2164{
2165 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2166}
2167
2168/**
2169 * smack_task_setioprio - Smack check on setting ioprio
2170 * @p: the task object
2171 * @ioprio: unused
2172 *
2173 * Return 0 if write access is permitted
2174 */
2175static int smack_task_setioprio(struct task_struct *p, int ioprio)
2176{
2177 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2178}
2179
2180/**
2181 * smack_task_getioprio - Smack check on reading ioprio
2182 * @p: the task object
2183 *
2184 * Return 0 if read access is permitted
2185 */
2186static int smack_task_getioprio(struct task_struct *p)
2187{
2188 return smk_curacc_on_task(p, MAY_READ, __func__);
2189}
2190
2191/**
2192 * smack_task_setscheduler - Smack check on setting scheduler
2193 * @p: the task object
2194 *
2195 * Return 0 if read access is permitted
2196 */
2197static int smack_task_setscheduler(struct task_struct *p)
2198{
2199 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2200}
2201
2202/**
2203 * smack_task_getscheduler - Smack check on reading scheduler
2204 * @p: the task object
2205 *
2206 * Return 0 if read access is permitted
2207 */
2208static int smack_task_getscheduler(struct task_struct *p)
2209{
2210 return smk_curacc_on_task(p, MAY_READ, __func__);
2211}
2212
2213/**
2214 * smack_task_movememory - Smack check on moving memory
2215 * @p: the task object
2216 *
2217 * Return 0 if write access is permitted
2218 */
2219static int smack_task_movememory(struct task_struct *p)
2220{
2221 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2222}
2223
2224/**
2225 * smack_task_kill - Smack check on signal delivery
2226 * @p: the task object
2227 * @info: unused
2228 * @sig: unused
2229 * @cred: identifies the cred to use in lieu of current's
2230 *
2231 * Return 0 if write access is permitted
2232 *
2233 */
2234static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
2235 int sig, const struct cred *cred)
2236{
2237 struct smk_audit_info ad;
2238 struct smack_known *skp;
2239 struct smack_known *tkp = smk_of_task_struct_obj(p);
2240 int rc;
2241
2242 if (!sig)
2243 return 0; /* null signal; existence test */
2244
2245 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
2246 smk_ad_setfield_u_tsk(&ad, p);
2247 /*
2248 * Sending a signal requires that the sender
2249 * can write the receiver.
2250 */
2251 if (cred == NULL) {
2252 rc = smk_curacc(tkp, MAY_DELIVER, &ad);
2253 rc = smk_bu_task(p, MAY_DELIVER, rc);
2254 return rc;
2255 }
2256 /*
2257 * If the cred isn't NULL we're dealing with some USB IO
2258 * specific behavior. This is not clean. For one thing
2259 * we can't take privilege into account.
2260 */
2261 skp = smk_of_task(smack_cred(cred));
2262 rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
2263 rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
2264 return rc;
2265}
2266
2267/**
2268 * smack_task_to_inode - copy task smack into the inode blob
2269 * @p: task to copy from
2270 * @inode: inode to copy to
2271 *
2272 * Sets the smack pointer in the inode security blob
2273 */
2274static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
2275{
2276 struct inode_smack *isp = smack_inode(inode);
2277 struct smack_known *skp = smk_of_task_struct_obj(p);
2278
2279 isp->smk_inode = skp;
2280 isp->smk_flags |= SMK_INODE_INSTANT;
2281}
2282
2283/*
2284 * Socket hooks.
2285 */
2286
2287/**
2288 * smack_sk_alloc_security - Allocate a socket blob
2289 * @sk: the socket
2290 * @family: unused
2291 * @gfp_flags: memory allocation flags
2292 *
2293 * Assign Smack pointers to current
2294 *
2295 * Returns 0 on success, -ENOMEM is there's no memory
2296 */
2297static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
2298{
2299 struct smack_known *skp = smk_of_current();
2300 struct socket_smack *ssp;
2301
2302 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
2303 if (ssp == NULL)
2304 return -ENOMEM;
2305
2306 /*
2307 * Sockets created by kernel threads receive web label.
2308 */
2309 if (unlikely(current->flags & PF_KTHREAD)) {
2310 ssp->smk_in = &smack_known_web;
2311 ssp->smk_out = &smack_known_web;
2312 } else {
2313 ssp->smk_in = skp;
2314 ssp->smk_out = skp;
2315 }
2316 ssp->smk_packet = NULL;
2317
2318 sk->sk_security = ssp;
2319
2320 return 0;
2321}
2322
2323/**
2324 * smack_sk_free_security - Free a socket blob
2325 * @sk: the socket
2326 *
2327 * Clears the blob pointer
2328 */
2329static void smack_sk_free_security(struct sock *sk)
2330{
2331#ifdef SMACK_IPV6_PORT_LABELING
2332 struct smk_port_label *spp;
2333
2334 if (sk->sk_family == PF_INET6) {
2335 rcu_read_lock();
2336 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2337 if (spp->smk_sock != sk)
2338 continue;
2339 spp->smk_can_reuse = 1;
2340 break;
2341 }
2342 rcu_read_unlock();
2343 }
2344#endif
2345 kfree(sk->sk_security);
2346}
2347
2348/**
2349 * smack_sk_clone_security - Copy security context
2350 * @sk: the old socket
2351 * @newsk: the new socket
2352 *
2353 * Copy the security context of the old socket pointer to the cloned
2354 */
2355static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk)
2356{
2357 struct socket_smack *ssp_old = sk->sk_security;
2358 struct socket_smack *ssp_new = newsk->sk_security;
2359
2360 *ssp_new = *ssp_old;
2361}
2362
2363/**
2364* smack_ipv4host_label - check host based restrictions
2365* @sip: the object end
2366*
2367* looks for host based access restrictions
2368*
2369* This version will only be appropriate for really small sets of single label
2370* hosts. The caller is responsible for ensuring that the RCU read lock is
2371* taken before calling this function.
2372*
2373* Returns the label of the far end or NULL if it's not special.
2374*/
2375static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
2376{
2377 struct smk_net4addr *snp;
2378 struct in_addr *siap = &sip->sin_addr;
2379
2380 if (siap->s_addr == 0)
2381 return NULL;
2382
2383 list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
2384 /*
2385 * we break after finding the first match because
2386 * the list is sorted from longest to shortest mask
2387 * so we have found the most specific match
2388 */
2389 if (snp->smk_host.s_addr ==
2390 (siap->s_addr & snp->smk_mask.s_addr))
2391 return snp->smk_label;
2392
2393 return NULL;
2394}
2395
2396/*
2397 * smk_ipv6_localhost - Check for local ipv6 host address
2398 * @sip: the address
2399 *
2400 * Returns boolean true if this is the localhost address
2401 */
2402static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
2403{
2404 __be16 *be16p = (__be16 *)&sip->sin6_addr;
2405 __be32 *be32p = (__be32 *)&sip->sin6_addr;
2406
2407 if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
2408 ntohs(be16p[7]) == 1)
2409 return true;
2410 return false;
2411}
2412
2413/**
2414* smack_ipv6host_label - check host based restrictions
2415* @sip: the object end
2416*
2417* looks for host based access restrictions
2418*
2419* This version will only be appropriate for really small sets of single label
2420* hosts. The caller is responsible for ensuring that the RCU read lock is
2421* taken before calling this function.
2422*
2423* Returns the label of the far end or NULL if it's not special.
2424*/
2425static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
2426{
2427 struct smk_net6addr *snp;
2428 struct in6_addr *sap = &sip->sin6_addr;
2429 int i;
2430 int found = 0;
2431
2432 /*
2433 * It's local. Don't look for a host label.
2434 */
2435 if (smk_ipv6_localhost(sip))
2436 return NULL;
2437
2438 list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
2439 /*
2440 * If the label is NULL the entry has
2441 * been renounced. Ignore it.
2442 */
2443 if (snp->smk_label == NULL)
2444 continue;
2445 /*
2446 * we break after finding the first match because
2447 * the list is sorted from longest to shortest mask
2448 * so we have found the most specific match
2449 */
2450 for (found = 1, i = 0; i < 8; i++) {
2451 if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
2452 snp->smk_host.s6_addr16[i]) {
2453 found = 0;
2454 break;
2455 }
2456 }
2457 if (found)
2458 return snp->smk_label;
2459 }
2460
2461 return NULL;
2462}
2463
2464/**
2465 * smack_netlbl_add - Set the secattr on a socket
2466 * @sk: the socket
2467 *
2468 * Attach the outbound smack value (smk_out) to the socket.
2469 *
2470 * Returns 0 on success or an error code
2471 */
2472static int smack_netlbl_add(struct sock *sk)
2473{
2474 struct socket_smack *ssp = sk->sk_security;
2475 struct smack_known *skp = ssp->smk_out;
2476 int rc;
2477
2478 local_bh_disable();
2479 bh_lock_sock_nested(sk);
2480
2481 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2482 switch (rc) {
2483 case 0:
2484 ssp->smk_state = SMK_NETLBL_LABELED;
2485 break;
2486 case -EDESTADDRREQ:
2487 ssp->smk_state = SMK_NETLBL_REQSKB;
2488 rc = 0;
2489 break;
2490 }
2491
2492 bh_unlock_sock(sk);
2493 local_bh_enable();
2494
2495 return rc;
2496}
2497
2498/**
2499 * smack_netlbl_delete - Remove the secattr from a socket
2500 * @sk: the socket
2501 *
2502 * Remove the outbound smack value from a socket
2503 */
2504static void smack_netlbl_delete(struct sock *sk)
2505{
2506 struct socket_smack *ssp = sk->sk_security;
2507
2508 /*
2509 * Take the label off the socket if one is set.
2510 */
2511 if (ssp->smk_state != SMK_NETLBL_LABELED)
2512 return;
2513
2514 local_bh_disable();
2515 bh_lock_sock_nested(sk);
2516 netlbl_sock_delattr(sk);
2517 bh_unlock_sock(sk);
2518 local_bh_enable();
2519 ssp->smk_state = SMK_NETLBL_UNLABELED;
2520}
2521
2522/**
2523 * smk_ipv4_check - Perform IPv4 host access checks
2524 * @sk: the socket
2525 * @sap: the destination address
2526 *
2527 * Set the correct secattr for the given socket based on the destination
2528 * address and perform any outbound access checks needed.
2529 *
2530 * Returns 0 on success or an error code.
2531 *
2532 */
2533static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
2534{
2535 struct smack_known *skp;
2536 int rc = 0;
2537 struct smack_known *hkp;
2538 struct socket_smack *ssp = sk->sk_security;
2539 struct smk_audit_info ad;
2540
2541 rcu_read_lock();
2542 hkp = smack_ipv4host_label(sap);
2543 if (hkp != NULL) {
2544#ifdef CONFIG_AUDIT
2545 struct lsm_network_audit net;
2546
2547 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2548 ad.a.u.net->family = sap->sin_family;
2549 ad.a.u.net->dport = sap->sin_port;
2550 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
2551#endif
2552 skp = ssp->smk_out;
2553 rc = smk_access(skp, hkp, MAY_WRITE, &ad);
2554 rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2555 /*
2556 * Clear the socket netlabel if it's set.
2557 */
2558 if (!rc)
2559 smack_netlbl_delete(sk);
2560 }
2561 rcu_read_unlock();
2562
2563 return rc;
2564}
2565
2566/**
2567 * smk_ipv6_check - check Smack access
2568 * @subject: subject Smack label
2569 * @object: object Smack label
2570 * @address: address
2571 * @act: the action being taken
2572 *
2573 * Check an IPv6 access
2574 */
2575static int smk_ipv6_check(struct smack_known *subject,
2576 struct smack_known *object,
2577 struct sockaddr_in6 *address, int act)
2578{
2579#ifdef CONFIG_AUDIT
2580 struct lsm_network_audit net;
2581#endif
2582 struct smk_audit_info ad;
2583 int rc;
2584
2585#ifdef CONFIG_AUDIT
2586 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2587 ad.a.u.net->family = PF_INET6;
2588 ad.a.u.net->dport = address->sin6_port;
2589 if (act == SMK_RECEIVING)
2590 ad.a.u.net->v6info.saddr = address->sin6_addr;
2591 else
2592 ad.a.u.net->v6info.daddr = address->sin6_addr;
2593#endif
2594 rc = smk_access(subject, object, MAY_WRITE, &ad);
2595 rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
2596 return rc;
2597}
2598
2599#ifdef SMACK_IPV6_PORT_LABELING
2600/**
2601 * smk_ipv6_port_label - Smack port access table management
2602 * @sock: socket
2603 * @address: address
2604 *
2605 * Create or update the port list entry
2606 */
2607static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
2608{
2609 struct sock *sk = sock->sk;
2610 struct sockaddr_in6 *addr6;
2611 struct socket_smack *ssp = sock->sk->sk_security;
2612 struct smk_port_label *spp;
2613 unsigned short port = 0;
2614
2615 if (address == NULL) {
2616 /*
2617 * This operation is changing the Smack information
2618 * on the bound socket. Take the changes to the port
2619 * as well.
2620 */
2621 rcu_read_lock();
2622 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2623 if (sk != spp->smk_sock)
2624 continue;
2625 spp->smk_in = ssp->smk_in;
2626 spp->smk_out = ssp->smk_out;
2627 rcu_read_unlock();
2628 return;
2629 }
2630 /*
2631 * A NULL address is only used for updating existing
2632 * bound entries. If there isn't one, it's OK.
2633 */
2634 rcu_read_unlock();
2635 return;
2636 }
2637
2638 addr6 = (struct sockaddr_in6 *)address;
2639 port = ntohs(addr6->sin6_port);
2640 /*
2641 * This is a special case that is safely ignored.
2642 */
2643 if (port == 0)
2644 return;
2645
2646 /*
2647 * Look for an existing port list entry.
2648 * This is an indication that a port is getting reused.
2649 */
2650 rcu_read_lock();
2651 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2652 if (spp->smk_port != port || spp->smk_sock_type != sock->type)
2653 continue;
2654 if (spp->smk_can_reuse != 1) {
2655 rcu_read_unlock();
2656 return;
2657 }
2658 spp->smk_port = port;
2659 spp->smk_sock = sk;
2660 spp->smk_in = ssp->smk_in;
2661 spp->smk_out = ssp->smk_out;
2662 spp->smk_can_reuse = 0;
2663 rcu_read_unlock();
2664 return;
2665 }
2666 rcu_read_unlock();
2667 /*
2668 * A new port entry is required.
2669 */
2670 spp = kzalloc(sizeof(*spp), GFP_KERNEL);
2671 if (spp == NULL)
2672 return;
2673
2674 spp->smk_port = port;
2675 spp->smk_sock = sk;
2676 spp->smk_in = ssp->smk_in;
2677 spp->smk_out = ssp->smk_out;
2678 spp->smk_sock_type = sock->type;
2679 spp->smk_can_reuse = 0;
2680
2681 mutex_lock(&smack_ipv6_lock);
2682 list_add_rcu(&spp->list, &smk_ipv6_port_list);
2683 mutex_unlock(&smack_ipv6_lock);
2684 return;
2685}
2686
2687/**
2688 * smk_ipv6_port_check - check Smack port access
2689 * @sk: socket
2690 * @address: address
2691 * @act: the action being taken
2692 *
2693 * Create or update the port list entry
2694 */
2695static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2696 int act)
2697{
2698 struct smk_port_label *spp;
2699 struct socket_smack *ssp = sk->sk_security;
2700 struct smack_known *skp = NULL;
2701 unsigned short port;
2702 struct smack_known *object;
2703
2704 if (act == SMK_RECEIVING) {
2705 skp = smack_ipv6host_label(address);
2706 object = ssp->smk_in;
2707 } else {
2708 skp = ssp->smk_out;
2709 object = smack_ipv6host_label(address);
2710 }
2711
2712 /*
2713 * The other end is a single label host.
2714 */
2715 if (skp != NULL && object != NULL)
2716 return smk_ipv6_check(skp, object, address, act);
2717 if (skp == NULL)
2718 skp = smack_net_ambient;
2719 if (object == NULL)
2720 object = smack_net_ambient;
2721
2722 /*
2723 * It's remote, so port lookup does no good.
2724 */
2725 if (!smk_ipv6_localhost(address))
2726 return smk_ipv6_check(skp, object, address, act);
2727
2728 /*
2729 * It's local so the send check has to have passed.
2730 */
2731 if (act == SMK_RECEIVING)
2732 return 0;
2733
2734 port = ntohs(address->sin6_port);
2735 rcu_read_lock();
2736 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2737 if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type)
2738 continue;
2739 object = spp->smk_in;
2740 if (act == SMK_CONNECTING)
2741 ssp->smk_packet = spp->smk_out;
2742 break;
2743 }
2744 rcu_read_unlock();
2745
2746 return smk_ipv6_check(skp, object, address, act);
2747}
2748#endif
2749
2750/**
2751 * smack_inode_setsecurity - set smack xattrs
2752 * @inode: the object
2753 * @name: attribute name
2754 * @value: attribute value
2755 * @size: size of the attribute
2756 * @flags: unused
2757 *
2758 * Sets the named attribute in the appropriate blob
2759 *
2760 * Returns 0 on success, or an error code
2761 */
2762static int smack_inode_setsecurity(struct inode *inode, const char *name,
2763 const void *value, size_t size, int flags)
2764{
2765 struct smack_known *skp;
2766 struct inode_smack *nsp = smack_inode(inode);
2767 struct socket_smack *ssp;
2768 struct socket *sock;
2769 int rc = 0;
2770
2771 if (value == NULL || size > SMK_LONGLABEL || size == 0)
2772 return -EINVAL;
2773
2774 skp = smk_import_entry(value, size);
2775 if (IS_ERR(skp))
2776 return PTR_ERR(skp);
2777
2778 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2779 nsp->smk_inode = skp;
2780 nsp->smk_flags |= SMK_INODE_INSTANT;
2781 return 0;
2782 }
2783 /*
2784 * The rest of the Smack xattrs are only on sockets.
2785 */
2786 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
2787 return -EOPNOTSUPP;
2788
2789 sock = SOCKET_I(inode);
2790 if (sock == NULL || sock->sk == NULL)
2791 return -EOPNOTSUPP;
2792
2793 ssp = sock->sk->sk_security;
2794
2795 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2796 ssp->smk_in = skp;
2797 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2798 ssp->smk_out = skp;
2799 if (sock->sk->sk_family == PF_INET) {
2800 rc = smack_netlbl_add(sock->sk);
2801 if (rc != 0)
2802 printk(KERN_WARNING
2803 "Smack: \"%s\" netlbl error %d.\n",
2804 __func__, -rc);
2805 }
2806 } else
2807 return -EOPNOTSUPP;
2808
2809#ifdef SMACK_IPV6_PORT_LABELING
2810 if (sock->sk->sk_family == PF_INET6)
2811 smk_ipv6_port_label(sock, NULL);
2812#endif
2813
2814 return 0;
2815}
2816
2817/**
2818 * smack_socket_post_create - finish socket setup
2819 * @sock: the socket
2820 * @family: protocol family
2821 * @type: unused
2822 * @protocol: unused
2823 * @kern: unused
2824 *
2825 * Sets the netlabel information on the socket
2826 *
2827 * Returns 0 on success, and error code otherwise
2828 */
2829static int smack_socket_post_create(struct socket *sock, int family,
2830 int type, int protocol, int kern)
2831{
2832 struct socket_smack *ssp;
2833
2834 if (sock->sk == NULL)
2835 return 0;
2836
2837 /*
2838 * Sockets created by kernel threads receive web label.
2839 */
2840 if (unlikely(current->flags & PF_KTHREAD)) {
2841 ssp = sock->sk->sk_security;
2842 ssp->smk_in = &smack_known_web;
2843 ssp->smk_out = &smack_known_web;
2844 }
2845
2846 if (family != PF_INET)
2847 return 0;
2848 /*
2849 * Set the outbound netlbl.
2850 */
2851 return smack_netlbl_add(sock->sk);
2852}
2853
2854/**
2855 * smack_socket_socketpair - create socket pair
2856 * @socka: one socket
2857 * @sockb: another socket
2858 *
2859 * Cross reference the peer labels for SO_PEERSEC
2860 *
2861 * Returns 0
2862 */
2863static int smack_socket_socketpair(struct socket *socka,
2864 struct socket *sockb)
2865{
2866 struct socket_smack *asp = socka->sk->sk_security;
2867 struct socket_smack *bsp = sockb->sk->sk_security;
2868
2869 asp->smk_packet = bsp->smk_out;
2870 bsp->smk_packet = asp->smk_out;
2871
2872 return 0;
2873}
2874
2875#ifdef SMACK_IPV6_PORT_LABELING
2876/**
2877 * smack_socket_bind - record port binding information.
2878 * @sock: the socket
2879 * @address: the port address
2880 * @addrlen: size of the address
2881 *
2882 * Records the label bound to a port.
2883 *
2884 * Returns 0 on success, and error code otherwise
2885 */
2886static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
2887 int addrlen)
2888{
2889 if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) {
2890 if (addrlen < SIN6_LEN_RFC2133 ||
2891 address->sa_family != AF_INET6)
2892 return -EINVAL;
2893 smk_ipv6_port_label(sock, address);
2894 }
2895 return 0;
2896}
2897#endif /* SMACK_IPV6_PORT_LABELING */
2898
2899/**
2900 * smack_socket_connect - connect access check
2901 * @sock: the socket
2902 * @sap: the other end
2903 * @addrlen: size of sap
2904 *
2905 * Verifies that a connection may be possible
2906 *
2907 * Returns 0 on success, and error code otherwise
2908 */
2909static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2910 int addrlen)
2911{
2912 int rc = 0;
2913
2914 if (sock->sk == NULL)
2915 return 0;
2916 if (sock->sk->sk_family != PF_INET &&
2917 (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6))
2918 return 0;
2919 if (addrlen < offsetofend(struct sockaddr, sa_family))
2920 return 0;
2921 if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) {
2922 struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
2923 struct smack_known *rsp = NULL;
2924
2925 if (addrlen < SIN6_LEN_RFC2133)
2926 return 0;
2927 if (__is_defined(SMACK_IPV6_SECMARK_LABELING))
2928 rsp = smack_ipv6host_label(sip);
2929 if (rsp != NULL) {
2930 struct socket_smack *ssp = sock->sk->sk_security;
2931
2932 rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
2933 SMK_CONNECTING);
2934 }
2935#ifdef SMACK_IPV6_PORT_LABELING
2936 rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
2937#endif
2938
2939 return rc;
2940 }
2941 if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
2942 return 0;
2943 rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap);
2944 return rc;
2945}
2946
2947/**
2948 * smack_flags_to_may - convert S_ to MAY_ values
2949 * @flags: the S_ value
2950 *
2951 * Returns the equivalent MAY_ value
2952 */
2953static int smack_flags_to_may(int flags)
2954{
2955 int may = 0;
2956
2957 if (flags & S_IRUGO)
2958 may |= MAY_READ;
2959 if (flags & S_IWUGO)
2960 may |= MAY_WRITE;
2961 if (flags & S_IXUGO)
2962 may |= MAY_EXEC;
2963
2964 return may;
2965}
2966
2967/**
2968 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2969 * @msg: the object
2970 *
2971 * Returns 0
2972 */
2973static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2974{
2975 struct smack_known **blob = smack_msg_msg(msg);
2976
2977 *blob = smk_of_current();
2978 return 0;
2979}
2980
2981/**
2982 * smack_of_ipc - the smack pointer for the ipc
2983 * @isp: the object
2984 *
2985 * Returns a pointer to the smack value
2986 */
2987static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp)
2988{
2989 struct smack_known **blob = smack_ipc(isp);
2990
2991 return *blob;
2992}
2993
2994/**
2995 * smack_ipc_alloc_security - Set the security blob for ipc
2996 * @isp: the object
2997 *
2998 * Returns 0
2999 */
3000static int smack_ipc_alloc_security(struct kern_ipc_perm *isp)
3001{
3002 struct smack_known **blob = smack_ipc(isp);
3003
3004 *blob = smk_of_current();
3005 return 0;
3006}
3007
3008/**
3009 * smk_curacc_shm : check if current has access on shm
3010 * @isp : the object
3011 * @access : access requested
3012 *
3013 * Returns 0 if current has the requested access, error code otherwise
3014 */
3015static int smk_curacc_shm(struct kern_ipc_perm *isp, int access)
3016{
3017 struct smack_known *ssp = smack_of_ipc(isp);
3018 struct smk_audit_info ad;
3019 int rc;
3020
3021#ifdef CONFIG_AUDIT
3022 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3023 ad.a.u.ipc_id = isp->id;
3024#endif
3025 rc = smk_curacc(ssp, access, &ad);
3026 rc = smk_bu_current("shm", ssp, access, rc);
3027 return rc;
3028}
3029
3030/**
3031 * smack_shm_associate - Smack access check for shm
3032 * @isp: the object
3033 * @shmflg: access requested
3034 *
3035 * Returns 0 if current has the requested access, error code otherwise
3036 */
3037static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg)
3038{
3039 int may;
3040
3041 may = smack_flags_to_may(shmflg);
3042 return smk_curacc_shm(isp, may);
3043}
3044
3045/**
3046 * smack_shm_shmctl - Smack access check for shm
3047 * @isp: the object
3048 * @cmd: what it wants to do
3049 *
3050 * Returns 0 if current has the requested access, error code otherwise
3051 */
3052static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd)
3053{
3054 int may;
3055
3056 switch (cmd) {
3057 case IPC_STAT:
3058 case SHM_STAT:
3059 case SHM_STAT_ANY:
3060 may = MAY_READ;
3061 break;
3062 case IPC_SET:
3063 case SHM_LOCK:
3064 case SHM_UNLOCK:
3065 case IPC_RMID:
3066 may = MAY_READWRITE;
3067 break;
3068 case IPC_INFO:
3069 case SHM_INFO:
3070 /*
3071 * System level information.
3072 */
3073 return 0;
3074 default:
3075 return -EINVAL;
3076 }
3077 return smk_curacc_shm(isp, may);
3078}
3079
3080/**
3081 * smack_shm_shmat - Smack access for shmat
3082 * @isp: the object
3083 * @shmaddr: unused
3084 * @shmflg: access requested
3085 *
3086 * Returns 0 if current has the requested access, error code otherwise
3087 */
3088static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr,
3089 int shmflg)
3090{
3091 int may;
3092
3093 may = smack_flags_to_may(shmflg);
3094 return smk_curacc_shm(isp, may);
3095}
3096
3097/**
3098 * smk_curacc_sem : check if current has access on sem
3099 * @isp : the object
3100 * @access : access requested
3101 *
3102 * Returns 0 if current has the requested access, error code otherwise
3103 */
3104static int smk_curacc_sem(struct kern_ipc_perm *isp, int access)
3105{
3106 struct smack_known *ssp = smack_of_ipc(isp);
3107 struct smk_audit_info ad;
3108 int rc;
3109
3110#ifdef CONFIG_AUDIT
3111 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3112 ad.a.u.ipc_id = isp->id;
3113#endif
3114 rc = smk_curacc(ssp, access, &ad);
3115 rc = smk_bu_current("sem", ssp, access, rc);
3116 return rc;
3117}
3118
3119/**
3120 * smack_sem_associate - Smack access check for sem
3121 * @isp: the object
3122 * @semflg: access requested
3123 *
3124 * Returns 0 if current has the requested access, error code otherwise
3125 */
3126static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg)
3127{
3128 int may;
3129
3130 may = smack_flags_to_may(semflg);
3131 return smk_curacc_sem(isp, may);
3132}
3133
3134/**
3135 * smack_sem_semctl - Smack access check for sem
3136 * @isp: the object
3137 * @cmd: what it wants to do
3138 *
3139 * Returns 0 if current has the requested access, error code otherwise
3140 */
3141static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd)
3142{
3143 int may;
3144
3145 switch (cmd) {
3146 case GETPID:
3147 case GETNCNT:
3148 case GETZCNT:
3149 case GETVAL:
3150 case GETALL:
3151 case IPC_STAT:
3152 case SEM_STAT:
3153 case SEM_STAT_ANY:
3154 may = MAY_READ;
3155 break;
3156 case SETVAL:
3157 case SETALL:
3158 case IPC_RMID:
3159 case IPC_SET:
3160 may = MAY_READWRITE;
3161 break;
3162 case IPC_INFO:
3163 case SEM_INFO:
3164 /*
3165 * System level information
3166 */
3167 return 0;
3168 default:
3169 return -EINVAL;
3170 }
3171
3172 return smk_curacc_sem(isp, may);
3173}
3174
3175/**
3176 * smack_sem_semop - Smack checks of semaphore operations
3177 * @isp: the object
3178 * @sops: unused
3179 * @nsops: unused
3180 * @alter: unused
3181 *
3182 * Treated as read and write in all cases.
3183 *
3184 * Returns 0 if access is allowed, error code otherwise
3185 */
3186static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops,
3187 unsigned nsops, int alter)
3188{
3189 return smk_curacc_sem(isp, MAY_READWRITE);
3190}
3191
3192/**
3193 * smk_curacc_msq : helper to check if current has access on msq
3194 * @isp : the msq
3195 * @access : access requested
3196 *
3197 * return 0 if current has access, error otherwise
3198 */
3199static int smk_curacc_msq(struct kern_ipc_perm *isp, int access)
3200{
3201 struct smack_known *msp = smack_of_ipc(isp);
3202 struct smk_audit_info ad;
3203 int rc;
3204
3205#ifdef CONFIG_AUDIT
3206 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3207 ad.a.u.ipc_id = isp->id;
3208#endif
3209 rc = smk_curacc(msp, access, &ad);
3210 rc = smk_bu_current("msq", msp, access, rc);
3211 return rc;
3212}
3213
3214/**
3215 * smack_msg_queue_associate - Smack access check for msg_queue
3216 * @isp: the object
3217 * @msqflg: access requested
3218 *
3219 * Returns 0 if current has the requested access, error code otherwise
3220 */
3221static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg)
3222{
3223 int may;
3224
3225 may = smack_flags_to_may(msqflg);
3226 return smk_curacc_msq(isp, may);
3227}
3228
3229/**
3230 * smack_msg_queue_msgctl - Smack access check for msg_queue
3231 * @isp: the object
3232 * @cmd: what it wants to do
3233 *
3234 * Returns 0 if current has the requested access, error code otherwise
3235 */
3236static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd)
3237{
3238 int may;
3239
3240 switch (cmd) {
3241 case IPC_STAT:
3242 case MSG_STAT:
3243 case MSG_STAT_ANY:
3244 may = MAY_READ;
3245 break;
3246 case IPC_SET:
3247 case IPC_RMID:
3248 may = MAY_READWRITE;
3249 break;
3250 case IPC_INFO:
3251 case MSG_INFO:
3252 /*
3253 * System level information
3254 */
3255 return 0;
3256 default:
3257 return -EINVAL;
3258 }
3259
3260 return smk_curacc_msq(isp, may);
3261}
3262
3263/**
3264 * smack_msg_queue_msgsnd - Smack access check for msg_queue
3265 * @isp: the object
3266 * @msg: unused
3267 * @msqflg: access requested
3268 *
3269 * Returns 0 if current has the requested access, error code otherwise
3270 */
3271static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg,
3272 int msqflg)
3273{
3274 int may;
3275
3276 may = smack_flags_to_may(msqflg);
3277 return smk_curacc_msq(isp, may);
3278}
3279
3280/**
3281 * smack_msg_queue_msgrcv - Smack access check for msg_queue
3282 * @isp: the object
3283 * @msg: unused
3284 * @target: unused
3285 * @type: unused
3286 * @mode: unused
3287 *
3288 * Returns 0 if current has read and write access, error code otherwise
3289 */
3290static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp,
3291 struct msg_msg *msg,
3292 struct task_struct *target, long type,
3293 int mode)
3294{
3295 return smk_curacc_msq(isp, MAY_READWRITE);
3296}
3297
3298/**
3299 * smack_ipc_permission - Smack access for ipc_permission()
3300 * @ipp: the object permissions
3301 * @flag: access requested
3302 *
3303 * Returns 0 if current has read and write access, error code otherwise
3304 */
3305static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
3306{
3307 struct smack_known **blob = smack_ipc(ipp);
3308 struct smack_known *iskp = *blob;
3309 int may = smack_flags_to_may(flag);
3310 struct smk_audit_info ad;
3311 int rc;
3312
3313#ifdef CONFIG_AUDIT
3314 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3315 ad.a.u.ipc_id = ipp->id;
3316#endif
3317 rc = smk_curacc(iskp, may, &ad);
3318 rc = smk_bu_current("svipc", iskp, may, rc);
3319 return rc;
3320}
3321
3322/**
3323 * smack_ipc_getsecid - Extract smack security id
3324 * @ipp: the object permissions
3325 * @secid: where result will be saved
3326 */
3327static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
3328{
3329 struct smack_known **blob = smack_ipc(ipp);
3330 struct smack_known *iskp = *blob;
3331
3332 *secid = iskp->smk_secid;
3333}
3334
3335/**
3336 * smack_d_instantiate - Make sure the blob is correct on an inode
3337 * @opt_dentry: dentry where inode will be attached
3338 * @inode: the object
3339 *
3340 * Set the inode's security blob if it hasn't been done already.
3341 */
3342static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
3343{
3344 struct super_block *sbp;
3345 struct superblock_smack *sbsp;
3346 struct inode_smack *isp;
3347 struct smack_known *skp;
3348 struct smack_known *ckp = smk_of_current();
3349 struct smack_known *final;
3350 char trattr[TRANS_TRUE_SIZE];
3351 int transflag = 0;
3352 int rc;
3353 struct dentry *dp;
3354
3355 if (inode == NULL)
3356 return;
3357
3358 isp = smack_inode(inode);
3359
3360 /*
3361 * If the inode is already instantiated
3362 * take the quick way out
3363 */
3364 if (isp->smk_flags & SMK_INODE_INSTANT)
3365 return;
3366
3367 sbp = inode->i_sb;
3368 sbsp = smack_superblock(sbp);
3369 /*
3370 * We're going to use the superblock default label
3371 * if there's no label on the file.
3372 */
3373 final = sbsp->smk_default;
3374
3375 /*
3376 * If this is the root inode the superblock
3377 * may be in the process of initialization.
3378 * If that is the case use the root value out
3379 * of the superblock.
3380 */
3381 if (opt_dentry->d_parent == opt_dentry) {
3382 switch (sbp->s_magic) {
3383 case CGROUP_SUPER_MAGIC:
3384 case CGROUP2_SUPER_MAGIC:
3385 /*
3386 * The cgroup filesystem is never mounted,
3387 * so there's no opportunity to set the mount
3388 * options.
3389 */
3390 sbsp->smk_root = &smack_known_star;
3391 sbsp->smk_default = &smack_known_star;
3392 isp->smk_inode = sbsp->smk_root;
3393 break;
3394 case TMPFS_MAGIC:
3395 /*
3396 * What about shmem/tmpfs anonymous files with dentry
3397 * obtained from d_alloc_pseudo()?
3398 */
3399 isp->smk_inode = smk_of_current();
3400 break;
3401 case PIPEFS_MAGIC:
3402 isp->smk_inode = smk_of_current();
3403 break;
3404 case SOCKFS_MAGIC:
3405 /*
3406 * Socket access is controlled by the socket
3407 * structures associated with the task involved.
3408 */
3409 isp->smk_inode = &smack_known_star;
3410 break;
3411 default:
3412 isp->smk_inode = sbsp->smk_root;
3413 break;
3414 }
3415 isp->smk_flags |= SMK_INODE_INSTANT;
3416 return;
3417 }
3418
3419 /*
3420 * This is pretty hackish.
3421 * Casey says that we shouldn't have to do
3422 * file system specific code, but it does help
3423 * with keeping it simple.
3424 */
3425 switch (sbp->s_magic) {
3426 case SMACK_MAGIC:
3427 case CGROUP_SUPER_MAGIC:
3428 case CGROUP2_SUPER_MAGIC:
3429 /*
3430 * Casey says that it's a little embarrassing
3431 * that the smack file system doesn't do
3432 * extended attributes.
3433 *
3434 * Cgroupfs is special
3435 */
3436 final = &smack_known_star;
3437 break;
3438 case DEVPTS_SUPER_MAGIC:
3439 /*
3440 * devpts seems content with the label of the task.
3441 * Programs that change smack have to treat the
3442 * pty with respect.
3443 */
3444 final = ckp;
3445 break;
3446 case PROC_SUPER_MAGIC:
3447 /*
3448 * Casey says procfs appears not to care.
3449 * The superblock default suffices.
3450 */
3451 break;
3452 case TMPFS_MAGIC:
3453 /*
3454 * Device labels should come from the filesystem,
3455 * but watch out, because they're volitile,
3456 * getting recreated on every reboot.
3457 */
3458 final = &smack_known_star;
3459 /*
3460 * If a smack value has been set we want to use it,
3461 * but since tmpfs isn't giving us the opportunity
3462 * to set mount options simulate setting the
3463 * superblock default.
3464 */
3465 fallthrough;
3466 default:
3467 /*
3468 * This isn't an understood special case.
3469 * Get the value from the xattr.
3470 */
3471
3472 /*
3473 * UNIX domain sockets use lower level socket data.
3474 */
3475 if (S_ISSOCK(inode->i_mode)) {
3476 final = &smack_known_star;
3477 break;
3478 }
3479 /*
3480 * No xattr support means, alas, no SMACK label.
3481 * Use the aforeapplied default.
3482 * It would be curious if the label of the task
3483 * does not match that assigned.
3484 */
3485 if (!(inode->i_opflags & IOP_XATTR))
3486 break;
3487 /*
3488 * Get the dentry for xattr.
3489 */
3490 dp = dget(opt_dentry);
3491 skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
3492 if (!IS_ERR_OR_NULL(skp))
3493 final = skp;
3494
3495 /*
3496 * Transmuting directory
3497 */
3498 if (S_ISDIR(inode->i_mode)) {
3499 /*
3500 * If this is a new directory and the label was
3501 * transmuted when the inode was initialized
3502 * set the transmute attribute on the directory
3503 * and mark the inode.
3504 *
3505 * If there is a transmute attribute on the
3506 * directory mark the inode.
3507 */
3508 if (isp->smk_flags & SMK_INODE_CHANGED) {
3509 isp->smk_flags &= ~SMK_INODE_CHANGED;
3510 rc = __vfs_setxattr(&init_user_ns, dp, inode,
3511 XATTR_NAME_SMACKTRANSMUTE,
3512 TRANS_TRUE, TRANS_TRUE_SIZE,
3513 0);
3514 } else {
3515 rc = __vfs_getxattr(dp, inode,
3516 XATTR_NAME_SMACKTRANSMUTE, trattr,
3517 TRANS_TRUE_SIZE);
3518 if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
3519 TRANS_TRUE_SIZE) != 0)
3520 rc = -EINVAL;
3521 }
3522 if (rc >= 0)
3523 transflag = SMK_INODE_TRANSMUTE;
3524 }
3525 /*
3526 * Don't let the exec or mmap label be "*" or "@".
3527 */
3528 skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
3529 if (IS_ERR(skp) || skp == &smack_known_star ||
3530 skp == &smack_known_web)
3531 skp = NULL;
3532 isp->smk_task = skp;
3533
3534 skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
3535 if (IS_ERR(skp) || skp == &smack_known_star ||
3536 skp == &smack_known_web)
3537 skp = NULL;
3538 isp->smk_mmap = skp;
3539
3540 dput(dp);
3541 break;
3542 }
3543
3544 if (final == NULL)
3545 isp->smk_inode = ckp;
3546 else
3547 isp->smk_inode = final;
3548
3549 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3550
3551 return;
3552}
3553
3554/**
3555 * smack_getprocattr - Smack process attribute access
3556 * @p: the object task
3557 * @name: the name of the attribute in /proc/.../attr
3558 * @value: where to put the result
3559 *
3560 * Places a copy of the task Smack into value
3561 *
3562 * Returns the length of the smack label or an error code
3563 */
3564static int smack_getprocattr(struct task_struct *p, const char *name, char **value)
3565{
3566 struct smack_known *skp = smk_of_task_struct_obj(p);
3567 char *cp;
3568 int slen;
3569
3570 if (strcmp(name, "current") != 0)
3571 return -EINVAL;
3572
3573 cp = kstrdup(skp->smk_known, GFP_KERNEL);
3574 if (cp == NULL)
3575 return -ENOMEM;
3576
3577 slen = strlen(cp);
3578 *value = cp;
3579 return slen;
3580}
3581
3582/**
3583 * smack_setprocattr - Smack process attribute setting
3584 * @name: the name of the attribute in /proc/.../attr
3585 * @value: the value to set
3586 * @size: the size of the value
3587 *
3588 * Sets the Smack value of the task. Only setting self
3589 * is permitted and only with privilege
3590 *
3591 * Returns the length of the smack label or an error code
3592 */
3593static int smack_setprocattr(const char *name, void *value, size_t size)
3594{
3595 struct task_smack *tsp = smack_cred(current_cred());
3596 struct cred *new;
3597 struct smack_known *skp;
3598 struct smack_known_list_elem *sklep;
3599 int rc;
3600
3601 if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
3602 return -EPERM;
3603
3604 if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3605 return -EINVAL;
3606
3607 if (strcmp(name, "current") != 0)
3608 return -EINVAL;
3609
3610 skp = smk_import_entry(value, size);
3611 if (IS_ERR(skp))
3612 return PTR_ERR(skp);
3613
3614 /*
3615 * No process is ever allowed the web ("@") label
3616 * and the star ("*") label.
3617 */
3618 if (skp == &smack_known_web || skp == &smack_known_star)
3619 return -EINVAL;
3620
3621 if (!smack_privileged(CAP_MAC_ADMIN)) {
3622 rc = -EPERM;
3623 list_for_each_entry(sklep, &tsp->smk_relabel, list)
3624 if (sklep->smk_label == skp) {
3625 rc = 0;
3626 break;
3627 }
3628 if (rc)
3629 return rc;
3630 }
3631
3632 new = prepare_creds();
3633 if (new == NULL)
3634 return -ENOMEM;
3635
3636 tsp = smack_cred(new);
3637 tsp->smk_task = skp;
3638 /*
3639 * process can change its label only once
3640 */
3641 smk_destroy_label_list(&tsp->smk_relabel);
3642
3643 commit_creds(new);
3644 return size;
3645}
3646
3647/**
3648 * smack_unix_stream_connect - Smack access on UDS
3649 * @sock: one sock
3650 * @other: the other sock
3651 * @newsk: unused
3652 *
3653 * Return 0 if a subject with the smack of sock could access
3654 * an object with the smack of other, otherwise an error code
3655 */
3656static int smack_unix_stream_connect(struct sock *sock,
3657 struct sock *other, struct sock *newsk)
3658{
3659 struct smack_known *skp;
3660 struct smack_known *okp;
3661 struct socket_smack *ssp = sock->sk_security;
3662 struct socket_smack *osp = other->sk_security;
3663 struct socket_smack *nsp = newsk->sk_security;
3664 struct smk_audit_info ad;
3665 int rc = 0;
3666#ifdef CONFIG_AUDIT
3667 struct lsm_network_audit net;
3668#endif
3669
3670 if (!smack_privileged(CAP_MAC_OVERRIDE)) {
3671 skp = ssp->smk_out;
3672 okp = osp->smk_in;
3673#ifdef CONFIG_AUDIT
3674 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3675 smk_ad_setfield_u_net_sk(&ad, other);
3676#endif
3677 rc = smk_access(skp, okp, MAY_WRITE, &ad);
3678 rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
3679 if (rc == 0) {
3680 okp = osp->smk_out;
3681 skp = ssp->smk_in;
3682 rc = smk_access(okp, skp, MAY_WRITE, &ad);
3683 rc = smk_bu_note("UDS connect", okp, skp,
3684 MAY_WRITE, rc);
3685 }
3686 }
3687
3688 /*
3689 * Cross reference the peer labels for SO_PEERSEC.
3690 */
3691 if (rc == 0) {
3692 nsp->smk_packet = ssp->smk_out;
3693 ssp->smk_packet = osp->smk_out;
3694 }
3695
3696 return rc;
3697}
3698
3699/**
3700 * smack_unix_may_send - Smack access on UDS
3701 * @sock: one socket
3702 * @other: the other socket
3703 *
3704 * Return 0 if a subject with the smack of sock could access
3705 * an object with the smack of other, otherwise an error code
3706 */
3707static int smack_unix_may_send(struct socket *sock, struct socket *other)
3708{
3709 struct socket_smack *ssp = sock->sk->sk_security;
3710 struct socket_smack *osp = other->sk->sk_security;
3711 struct smk_audit_info ad;
3712 int rc;
3713
3714#ifdef CONFIG_AUDIT
3715 struct lsm_network_audit net;
3716
3717 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3718 smk_ad_setfield_u_net_sk(&ad, other->sk);
3719#endif
3720
3721 if (smack_privileged(CAP_MAC_OVERRIDE))
3722 return 0;
3723
3724 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
3725 rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
3726 return rc;
3727}
3728
3729/**
3730 * smack_socket_sendmsg - Smack check based on destination host
3731 * @sock: the socket
3732 * @msg: the message
3733 * @size: the size of the message
3734 *
3735 * Return 0 if the current subject can write to the destination host.
3736 * For IPv4 this is only a question if the destination is a single label host.
3737 * For IPv6 this is a check against the label of the port.
3738 */
3739static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3740 int size)
3741{
3742 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3743#if IS_ENABLED(CONFIG_IPV6)
3744 struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3745#endif
3746#ifdef SMACK_IPV6_SECMARK_LABELING
3747 struct socket_smack *ssp = sock->sk->sk_security;
3748 struct smack_known *rsp;
3749#endif
3750 int rc = 0;
3751
3752 /*
3753 * Perfectly reasonable for this to be NULL
3754 */
3755 if (sip == NULL)
3756 return 0;
3757
3758 switch (sock->sk->sk_family) {
3759 case AF_INET:
3760 if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
3761 sip->sin_family != AF_INET)
3762 return -EINVAL;
3763 rc = smk_ipv4_check(sock->sk, sip);
3764 break;
3765#if IS_ENABLED(CONFIG_IPV6)
3766 case AF_INET6:
3767 if (msg->msg_namelen < SIN6_LEN_RFC2133 ||
3768 sap->sin6_family != AF_INET6)
3769 return -EINVAL;
3770#ifdef SMACK_IPV6_SECMARK_LABELING
3771 rsp = smack_ipv6host_label(sap);
3772 if (rsp != NULL)
3773 rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
3774 SMK_CONNECTING);
3775#endif
3776#ifdef SMACK_IPV6_PORT_LABELING
3777 rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3778#endif
3779#endif /* IS_ENABLED(CONFIG_IPV6) */
3780 break;
3781 }
3782 return rc;
3783}
3784
3785/**
3786 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3787 * @sap: netlabel secattr
3788 * @ssp: socket security information
3789 *
3790 * Returns a pointer to a Smack label entry found on the label list.
3791 */
3792static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
3793 struct socket_smack *ssp)
3794{
3795 struct smack_known *skp;
3796 int found = 0;
3797 int acat;
3798 int kcat;
3799
3800 /*
3801 * Netlabel found it in the cache.
3802 */
3803 if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
3804 return (struct smack_known *)sap->cache->data;
3805
3806 if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
3807 /*
3808 * Looks like a fallback, which gives us a secid.
3809 */
3810 return smack_from_secid(sap->attr.secid);
3811
3812 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3813 /*
3814 * Looks like a CIPSO packet.
3815 * If there are flags but no level netlabel isn't
3816 * behaving the way we expect it to.
3817 *
3818 * Look it up in the label table
3819 * Without guidance regarding the smack value
3820 * for the packet fall back on the network
3821 * ambient value.
3822 */
3823 rcu_read_lock();
3824 list_for_each_entry_rcu(skp, &smack_known_list, list) {
3825 if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3826 continue;
3827 /*
3828 * Compare the catsets. Use the netlbl APIs.
3829 */
3830 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
3831 if ((skp->smk_netlabel.flags &
3832 NETLBL_SECATTR_MLS_CAT) == 0)
3833 found = 1;
3834 break;
3835 }
3836 for (acat = -1, kcat = -1; acat == kcat; ) {
3837 acat = netlbl_catmap_walk(sap->attr.mls.cat,
3838 acat + 1);
3839 kcat = netlbl_catmap_walk(
3840 skp->smk_netlabel.attr.mls.cat,
3841 kcat + 1);
3842 if (acat < 0 || kcat < 0)
3843 break;
3844 }
3845 if (acat == kcat) {
3846 found = 1;
3847 break;
3848 }
3849 }
3850 rcu_read_unlock();
3851
3852 if (found)
3853 return skp;
3854
3855 if (ssp != NULL && ssp->smk_in == &smack_known_star)
3856 return &smack_known_web;
3857 return &smack_known_star;
3858 }
3859 /*
3860 * Without guidance regarding the smack value
3861 * for the packet fall back on the network
3862 * ambient value.
3863 */
3864 return smack_net_ambient;
3865}
3866
3867#if IS_ENABLED(CONFIG_IPV6)
3868static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3869{
3870 u8 nexthdr;
3871 int offset;
3872 int proto = -EINVAL;
3873 struct ipv6hdr _ipv6h;
3874 struct ipv6hdr *ip6;
3875 __be16 frag_off;
3876 struct tcphdr _tcph, *th;
3877 struct udphdr _udph, *uh;
3878 struct dccp_hdr _dccph, *dh;
3879
3880 sip->sin6_port = 0;
3881
3882 offset = skb_network_offset(skb);
3883 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3884 if (ip6 == NULL)
3885 return -EINVAL;
3886 sip->sin6_addr = ip6->saddr;
3887
3888 nexthdr = ip6->nexthdr;
3889 offset += sizeof(_ipv6h);
3890 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3891 if (offset < 0)
3892 return -EINVAL;
3893
3894 proto = nexthdr;
3895 switch (proto) {
3896 case IPPROTO_TCP:
3897 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3898 if (th != NULL)
3899 sip->sin6_port = th->source;
3900 break;
3901 case IPPROTO_UDP:
3902 case IPPROTO_UDPLITE:
3903 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3904 if (uh != NULL)
3905 sip->sin6_port = uh->source;
3906 break;
3907 case IPPROTO_DCCP:
3908 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3909 if (dh != NULL)
3910 sip->sin6_port = dh->dccph_sport;
3911 break;
3912 }
3913 return proto;
3914}
3915#endif /* CONFIG_IPV6 */
3916
3917/**
3918 * smack_from_skb - Smack data from the secmark in an skb
3919 * @skb: packet
3920 *
3921 * Returns smack_known of the secmark or NULL if that won't work.
3922 */
3923#ifdef CONFIG_NETWORK_SECMARK
3924static struct smack_known *smack_from_skb(struct sk_buff *skb)
3925{
3926 if (skb == NULL || skb->secmark == 0)
3927 return NULL;
3928
3929 return smack_from_secid(skb->secmark);
3930}
3931#else
3932static inline struct smack_known *smack_from_skb(struct sk_buff *skb)
3933{
3934 return NULL;
3935}
3936#endif
3937
3938/**
3939 * smack_from_netlbl - Smack data from the IP options in an skb
3940 * @sk: socket data came in on
3941 * @family: address family
3942 * @skb: packet
3943 *
3944 * Find the Smack label in the IP options. If it hasn't been
3945 * added to the netlabel cache, add it here.
3946 *
3947 * Returns smack_known of the IP options or NULL if that won't work.
3948 */
3949static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
3950 struct sk_buff *skb)
3951{
3952 struct netlbl_lsm_secattr secattr;
3953 struct socket_smack *ssp = NULL;
3954 struct smack_known *skp = NULL;
3955
3956 netlbl_secattr_init(&secattr);
3957
3958 if (sk)
3959 ssp = sk->sk_security;
3960
3961 if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
3962 skp = smack_from_secattr(&secattr, ssp);
3963 if (secattr.flags & NETLBL_SECATTR_CACHEABLE)
3964 netlbl_cache_add(skb, family, &skp->smk_netlabel);
3965 }
3966
3967 netlbl_secattr_destroy(&secattr);
3968
3969 return skp;
3970}
3971
3972/**
3973 * smack_socket_sock_rcv_skb - Smack packet delivery access check
3974 * @sk: socket
3975 * @skb: packet
3976 *
3977 * Returns 0 if the packet should be delivered, an error code otherwise
3978 */
3979static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
3980{
3981 struct socket_smack *ssp = sk->sk_security;
3982 struct smack_known *skp = NULL;
3983 int rc = 0;
3984 struct smk_audit_info ad;
3985 u16 family = sk->sk_family;
3986#ifdef CONFIG_AUDIT
3987 struct lsm_network_audit net;
3988#endif
3989#if IS_ENABLED(CONFIG_IPV6)
3990 struct sockaddr_in6 sadd;
3991 int proto;
3992
3993 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3994 family = PF_INET;
3995#endif /* CONFIG_IPV6 */
3996
3997 switch (family) {
3998 case PF_INET:
3999 /*
4000 * If there is a secmark use it rather than the CIPSO label.
4001 * If there is no secmark fall back to CIPSO.
4002 * The secmark is assumed to reflect policy better.
4003 */
4004 skp = smack_from_skb(skb);
4005 if (skp == NULL) {
4006 skp = smack_from_netlbl(sk, family, skb);
4007 if (skp == NULL)
4008 skp = smack_net_ambient;
4009 }
4010
4011#ifdef CONFIG_AUDIT
4012 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4013 ad.a.u.net->family = family;
4014 ad.a.u.net->netif = skb->skb_iif;
4015 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4016#endif
4017 /*
4018 * Receiving a packet requires that the other end
4019 * be able to write here. Read access is not required.
4020 * This is the simplist possible security model
4021 * for networking.
4022 */
4023 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4024 rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
4025 MAY_WRITE, rc);
4026 if (rc != 0)
4027 netlbl_skbuff_err(skb, family, rc, 0);
4028 break;
4029#if IS_ENABLED(CONFIG_IPV6)
4030 case PF_INET6:
4031 proto = smk_skb_to_addr_ipv6(skb, &sadd);
4032 if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE &&
4033 proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
4034 break;
4035#ifdef SMACK_IPV6_SECMARK_LABELING
4036 skp = smack_from_skb(skb);
4037 if (skp == NULL) {
4038 if (smk_ipv6_localhost(&sadd))
4039 break;
4040 skp = smack_ipv6host_label(&sadd);
4041 if (skp == NULL)
4042 skp = smack_net_ambient;
4043 }
4044#ifdef CONFIG_AUDIT
4045 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4046 ad.a.u.net->family = family;
4047 ad.a.u.net->netif = skb->skb_iif;
4048 ipv6_skb_to_auditdata(skb, &ad.a, NULL);
4049#endif /* CONFIG_AUDIT */
4050 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4051 rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
4052 MAY_WRITE, rc);
4053#endif /* SMACK_IPV6_SECMARK_LABELING */
4054#ifdef SMACK_IPV6_PORT_LABELING
4055 rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
4056#endif /* SMACK_IPV6_PORT_LABELING */
4057 if (rc != 0)
4058 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
4059 ICMPV6_ADM_PROHIBITED, 0);
4060 break;
4061#endif /* CONFIG_IPV6 */
4062 }
4063
4064 return rc;
4065}
4066
4067/**
4068 * smack_socket_getpeersec_stream - pull in packet label
4069 * @sock: the socket
4070 * @optval: user's destination
4071 * @optlen: size thereof
4072 * @len: max thereof
4073 *
4074 * returns zero on success, an error code otherwise
4075 */
4076static int smack_socket_getpeersec_stream(struct socket *sock,
4077 sockptr_t optval, sockptr_t optlen,
4078 unsigned int len)
4079{
4080 struct socket_smack *ssp;
4081 char *rcp = "";
4082 u32 slen = 1;
4083 int rc = 0;
4084
4085 ssp = sock->sk->sk_security;
4086 if (ssp->smk_packet != NULL) {
4087 rcp = ssp->smk_packet->smk_known;
4088 slen = strlen(rcp) + 1;
4089 }
4090 if (slen > len) {
4091 rc = -ERANGE;
4092 goto out_len;
4093 }
4094
4095 if (copy_to_sockptr(optval, rcp, slen))
4096 rc = -EFAULT;
4097out_len:
4098 if (copy_to_sockptr(optlen, &slen, sizeof(slen)))
4099 rc = -EFAULT;
4100 return rc;
4101}
4102
4103
4104/**
4105 * smack_socket_getpeersec_dgram - pull in packet label
4106 * @sock: the peer socket
4107 * @skb: packet data
4108 * @secid: pointer to where to put the secid of the packet
4109 *
4110 * Sets the netlabel socket state on sk from parent
4111 */
4112static int smack_socket_getpeersec_dgram(struct socket *sock,
4113 struct sk_buff *skb, u32 *secid)
4114
4115{
4116 struct socket_smack *ssp = NULL;
4117 struct smack_known *skp;
4118 struct sock *sk = NULL;
4119 int family = PF_UNSPEC;
4120 u32 s = 0; /* 0 is the invalid secid */
4121
4122 if (skb != NULL) {
4123 if (skb->protocol == htons(ETH_P_IP))
4124 family = PF_INET;
4125#if IS_ENABLED(CONFIG_IPV6)
4126 else if (skb->protocol == htons(ETH_P_IPV6))
4127 family = PF_INET6;
4128#endif /* CONFIG_IPV6 */
4129 }
4130 if (family == PF_UNSPEC && sock != NULL)
4131 family = sock->sk->sk_family;
4132
4133 switch (family) {
4134 case PF_UNIX:
4135 ssp = sock->sk->sk_security;
4136 s = ssp->smk_out->smk_secid;
4137 break;
4138 case PF_INET:
4139 skp = smack_from_skb(skb);
4140 if (skp) {
4141 s = skp->smk_secid;
4142 break;
4143 }
4144 /*
4145 * Translate what netlabel gave us.
4146 */
4147 if (sock != NULL)
4148 sk = sock->sk;
4149 skp = smack_from_netlbl(sk, family, skb);
4150 if (skp != NULL)
4151 s = skp->smk_secid;
4152 break;
4153 case PF_INET6:
4154#ifdef SMACK_IPV6_SECMARK_LABELING
4155 skp = smack_from_skb(skb);
4156 if (skp)
4157 s = skp->smk_secid;
4158#endif
4159 break;
4160 }
4161 *secid = s;
4162 if (s == 0)
4163 return -EINVAL;
4164 return 0;
4165}
4166
4167/**
4168 * smack_sock_graft - Initialize a newly created socket with an existing sock
4169 * @sk: child sock
4170 * @parent: parent socket
4171 *
4172 * Set the smk_{in,out} state of an existing sock based on the process that
4173 * is creating the new socket.
4174 */
4175static void smack_sock_graft(struct sock *sk, struct socket *parent)
4176{
4177 struct socket_smack *ssp;
4178 struct smack_known *skp = smk_of_current();
4179
4180 if (sk == NULL ||
4181 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
4182 return;
4183
4184 ssp = sk->sk_security;
4185 ssp->smk_in = skp;
4186 ssp->smk_out = skp;
4187 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
4188}
4189
4190/**
4191 * smack_inet_conn_request - Smack access check on connect
4192 * @sk: socket involved
4193 * @skb: packet
4194 * @req: unused
4195 *
4196 * Returns 0 if a task with the packet label could write to
4197 * the socket, otherwise an error code
4198 */
4199static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
4200 struct request_sock *req)
4201{
4202 u16 family = sk->sk_family;
4203 struct smack_known *skp;
4204 struct socket_smack *ssp = sk->sk_security;
4205 struct sockaddr_in addr;
4206 struct iphdr *hdr;
4207 struct smack_known *hskp;
4208 int rc;
4209 struct smk_audit_info ad;
4210#ifdef CONFIG_AUDIT
4211 struct lsm_network_audit net;
4212#endif
4213
4214#if IS_ENABLED(CONFIG_IPV6)
4215 if (family == PF_INET6) {
4216 /*
4217 * Handle mapped IPv4 packets arriving
4218 * via IPv6 sockets. Don't set up netlabel
4219 * processing on IPv6.
4220 */
4221 if (skb->protocol == htons(ETH_P_IP))
4222 family = PF_INET;
4223 else
4224 return 0;
4225 }
4226#endif /* CONFIG_IPV6 */
4227
4228 /*
4229 * If there is a secmark use it rather than the CIPSO label.
4230 * If there is no secmark fall back to CIPSO.
4231 * The secmark is assumed to reflect policy better.
4232 */
4233 skp = smack_from_skb(skb);
4234 if (skp == NULL) {
4235 skp = smack_from_netlbl(sk, family, skb);
4236 if (skp == NULL)
4237 skp = &smack_known_huh;
4238 }
4239
4240#ifdef CONFIG_AUDIT
4241 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4242 ad.a.u.net->family = family;
4243 ad.a.u.net->netif = skb->skb_iif;
4244 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4245#endif
4246 /*
4247 * Receiving a packet requires that the other end be able to write
4248 * here. Read access is not required.
4249 */
4250 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4251 rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
4252 if (rc != 0)
4253 return rc;
4254
4255 /*
4256 * Save the peer's label in the request_sock so we can later setup
4257 * smk_packet in the child socket so that SO_PEERCRED can report it.
4258 */
4259 req->peer_secid = skp->smk_secid;
4260
4261 /*
4262 * We need to decide if we want to label the incoming connection here
4263 * if we do we only need to label the request_sock and the stack will
4264 * propagate the wire-label to the sock when it is created.
4265 */
4266 hdr = ip_hdr(skb);
4267 addr.sin_addr.s_addr = hdr->saddr;
4268 rcu_read_lock();
4269 hskp = smack_ipv4host_label(&addr);
4270 rcu_read_unlock();
4271
4272 if (hskp == NULL)
4273 rc = netlbl_req_setattr(req, &skp->smk_netlabel);
4274 else
4275 netlbl_req_delattr(req);
4276
4277 return rc;
4278}
4279
4280/**
4281 * smack_inet_csk_clone - Copy the connection information to the new socket
4282 * @sk: the new socket
4283 * @req: the connection's request_sock
4284 *
4285 * Transfer the connection's peer label to the newly created socket.
4286 */
4287static void smack_inet_csk_clone(struct sock *sk,
4288 const struct request_sock *req)
4289{
4290 struct socket_smack *ssp = sk->sk_security;
4291 struct smack_known *skp;
4292
4293 if (req->peer_secid != 0) {
4294 skp = smack_from_secid(req->peer_secid);
4295 ssp->smk_packet = skp;
4296 } else
4297 ssp->smk_packet = NULL;
4298}
4299
4300/*
4301 * Key management security hooks
4302 *
4303 * Casey has not tested key support very heavily.
4304 * The permission check is most likely too restrictive.
4305 * If you care about keys please have a look.
4306 */
4307#ifdef CONFIG_KEYS
4308
4309/**
4310 * smack_key_alloc - Set the key security blob
4311 * @key: object
4312 * @cred: the credentials to use
4313 * @flags: unused
4314 *
4315 * No allocation required
4316 *
4317 * Returns 0
4318 */
4319static int smack_key_alloc(struct key *key, const struct cred *cred,
4320 unsigned long flags)
4321{
4322 struct smack_known *skp = smk_of_task(smack_cred(cred));
4323
4324 key->security = skp;
4325 return 0;
4326}
4327
4328/**
4329 * smack_key_free - Clear the key security blob
4330 * @key: the object
4331 *
4332 * Clear the blob pointer
4333 */
4334static void smack_key_free(struct key *key)
4335{
4336 key->security = NULL;
4337}
4338
4339/**
4340 * smack_key_permission - Smack access on a key
4341 * @key_ref: gets to the object
4342 * @cred: the credentials to use
4343 * @need_perm: requested key permission
4344 *
4345 * Return 0 if the task has read and write to the object,
4346 * an error code otherwise
4347 */
4348static int smack_key_permission(key_ref_t key_ref,
4349 const struct cred *cred,
4350 enum key_need_perm need_perm)
4351{
4352 struct key *keyp;
4353 struct smk_audit_info ad;
4354 struct smack_known *tkp = smk_of_task(smack_cred(cred));
4355 int request = 0;
4356 int rc;
4357
4358 /*
4359 * Validate requested permissions
4360 */
4361 switch (need_perm) {
4362 case KEY_NEED_READ:
4363 case KEY_NEED_SEARCH:
4364 case KEY_NEED_VIEW:
4365 request |= MAY_READ;
4366 break;
4367 case KEY_NEED_WRITE:
4368 case KEY_NEED_LINK:
4369 case KEY_NEED_SETATTR:
4370 request |= MAY_WRITE;
4371 break;
4372 case KEY_NEED_UNSPECIFIED:
4373 case KEY_NEED_UNLINK:
4374 case KEY_SYSADMIN_OVERRIDE:
4375 case KEY_AUTHTOKEN_OVERRIDE:
4376 case KEY_DEFER_PERM_CHECK:
4377 return 0;
4378 default:
4379 return -EINVAL;
4380 }
4381
4382 keyp = key_ref_to_ptr(key_ref);
4383 if (keyp == NULL)
4384 return -EINVAL;
4385 /*
4386 * If the key hasn't been initialized give it access so that
4387 * it may do so.
4388 */
4389 if (keyp->security == NULL)
4390 return 0;
4391 /*
4392 * This should not occur
4393 */
4394 if (tkp == NULL)
4395 return -EACCES;
4396
4397 if (smack_privileged(CAP_MAC_OVERRIDE))
4398 return 0;
4399
4400#ifdef CONFIG_AUDIT
4401 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4402 ad.a.u.key_struct.key = keyp->serial;
4403 ad.a.u.key_struct.key_desc = keyp->description;
4404#endif
4405 rc = smk_access(tkp, keyp->security, request, &ad);
4406 rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
4407 return rc;
4408}
4409
4410/*
4411 * smack_key_getsecurity - Smack label tagging the key
4412 * @key points to the key to be queried
4413 * @_buffer points to a pointer that should be set to point to the
4414 * resulting string (if no label or an error occurs).
4415 * Return the length of the string (including terminating NUL) or -ve if
4416 * an error.
4417 * May also return 0 (and a NULL buffer pointer) if there is no label.
4418 */
4419static int smack_key_getsecurity(struct key *key, char **_buffer)
4420{
4421 struct smack_known *skp = key->security;
4422 size_t length;
4423 char *copy;
4424
4425 if (key->security == NULL) {
4426 *_buffer = NULL;
4427 return 0;
4428 }
4429
4430 copy = kstrdup(skp->smk_known, GFP_KERNEL);
4431 if (copy == NULL)
4432 return -ENOMEM;
4433 length = strlen(copy) + 1;
4434
4435 *_buffer = copy;
4436 return length;
4437}
4438
4439
4440#ifdef CONFIG_KEY_NOTIFICATIONS
4441/**
4442 * smack_watch_key - Smack access to watch a key for notifications.
4443 * @key: The key to be watched
4444 *
4445 * Return 0 if the @watch->cred has permission to read from the key object and
4446 * an error otherwise.
4447 */
4448static int smack_watch_key(struct key *key)
4449{
4450 struct smk_audit_info ad;
4451 struct smack_known *tkp = smk_of_current();
4452 int rc;
4453
4454 if (key == NULL)
4455 return -EINVAL;
4456 /*
4457 * If the key hasn't been initialized give it access so that
4458 * it may do so.
4459 */
4460 if (key->security == NULL)
4461 return 0;
4462 /*
4463 * This should not occur
4464 */
4465 if (tkp == NULL)
4466 return -EACCES;
4467
4468 if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4469 return 0;
4470
4471#ifdef CONFIG_AUDIT
4472 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4473 ad.a.u.key_struct.key = key->serial;
4474 ad.a.u.key_struct.key_desc = key->description;
4475#endif
4476 rc = smk_access(tkp, key->security, MAY_READ, &ad);
4477 rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc);
4478 return rc;
4479}
4480#endif /* CONFIG_KEY_NOTIFICATIONS */
4481#endif /* CONFIG_KEYS */
4482
4483#ifdef CONFIG_WATCH_QUEUE
4484/**
4485 * smack_post_notification - Smack access to post a notification to a queue
4486 * @w_cred: The credentials of the watcher.
4487 * @cred: The credentials of the event source (may be NULL).
4488 * @n: The notification message to be posted.
4489 */
4490static int smack_post_notification(const struct cred *w_cred,
4491 const struct cred *cred,
4492 struct watch_notification *n)
4493{
4494 struct smk_audit_info ad;
4495 struct smack_known *subj, *obj;
4496 int rc;
4497
4498 /* Always let maintenance notifications through. */
4499 if (n->type == WATCH_TYPE_META)
4500 return 0;
4501
4502 if (!cred)
4503 return 0;
4504 subj = smk_of_task(smack_cred(cred));
4505 obj = smk_of_task(smack_cred(w_cred));
4506
4507 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION);
4508 rc = smk_access(subj, obj, MAY_WRITE, &ad);
4509 rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc);
4510 return rc;
4511}
4512#endif /* CONFIG_WATCH_QUEUE */
4513
4514/*
4515 * Smack Audit hooks
4516 *
4517 * Audit requires a unique representation of each Smack specific
4518 * rule. This unique representation is used to distinguish the
4519 * object to be audited from remaining kernel objects and also
4520 * works as a glue between the audit hooks.
4521 *
4522 * Since repository entries are added but never deleted, we'll use
4523 * the smack_known label address related to the given audit rule as
4524 * the needed unique representation. This also better fits the smack
4525 * model where nearly everything is a label.
4526 */
4527#ifdef CONFIG_AUDIT
4528
4529/**
4530 * smack_audit_rule_init - Initialize a smack audit rule
4531 * @field: audit rule fields given from user-space (audit.h)
4532 * @op: required testing operator (=, !=, >, <, ...)
4533 * @rulestr: smack label to be audited
4534 * @vrule: pointer to save our own audit rule representation
4535 *
4536 * Prepare to audit cases where (@field @op @rulestr) is true.
4537 * The label to be audited is created if necessay.
4538 */
4539static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
4540{
4541 struct smack_known *skp;
4542 char **rule = (char **)vrule;
4543 *rule = NULL;
4544
4545 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4546 return -EINVAL;
4547
4548 if (op != Audit_equal && op != Audit_not_equal)
4549 return -EINVAL;
4550
4551 skp = smk_import_entry(rulestr, 0);
4552 if (IS_ERR(skp))
4553 return PTR_ERR(skp);
4554
4555 *rule = skp->smk_known;
4556
4557 return 0;
4558}
4559
4560/**
4561 * smack_audit_rule_known - Distinguish Smack audit rules
4562 * @krule: rule of interest, in Audit kernel representation format
4563 *
4564 * This is used to filter Smack rules from remaining Audit ones.
4565 * If it's proved that this rule belongs to us, the
4566 * audit_rule_match hook will be called to do the final judgement.
4567 */
4568static int smack_audit_rule_known(struct audit_krule *krule)
4569{
4570 struct audit_field *f;
4571 int i;
4572
4573 for (i = 0; i < krule->field_count; i++) {
4574 f = &krule->fields[i];
4575
4576 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
4577 return 1;
4578 }
4579
4580 return 0;
4581}
4582
4583/**
4584 * smack_audit_rule_match - Audit given object ?
4585 * @secid: security id for identifying the object to test
4586 * @field: audit rule flags given from user-space
4587 * @op: required testing operator
4588 * @vrule: smack internal rule presentation
4589 *
4590 * The core Audit hook. It's used to take the decision of
4591 * whether to audit or not to audit a given object.
4592 */
4593static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
4594{
4595 struct smack_known *skp;
4596 char *rule = vrule;
4597
4598 if (unlikely(!rule)) {
4599 WARN_ONCE(1, "Smack: missing rule\n");
4600 return -ENOENT;
4601 }
4602
4603 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4604 return 0;
4605
4606 skp = smack_from_secid(secid);
4607
4608 /*
4609 * No need to do string comparisons. If a match occurs,
4610 * both pointers will point to the same smack_known
4611 * label.
4612 */
4613 if (op == Audit_equal)
4614 return (rule == skp->smk_known);
4615 if (op == Audit_not_equal)
4616 return (rule != skp->smk_known);
4617
4618 return 0;
4619}
4620
4621/*
4622 * There is no need for a smack_audit_rule_free hook.
4623 * No memory was allocated.
4624 */
4625
4626#endif /* CONFIG_AUDIT */
4627
4628/**
4629 * smack_ismaclabel - check if xattr @name references a smack MAC label
4630 * @name: Full xattr name to check.
4631 */
4632static int smack_ismaclabel(const char *name)
4633{
4634 return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
4635}
4636
4637
4638/**
4639 * smack_secid_to_secctx - return the smack label for a secid
4640 * @secid: incoming integer
4641 * @secdata: destination
4642 * @seclen: how long it is
4643 *
4644 * Exists for networking code.
4645 */
4646static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
4647{
4648 struct smack_known *skp = smack_from_secid(secid);
4649
4650 if (secdata)
4651 *secdata = skp->smk_known;
4652 *seclen = strlen(skp->smk_known);
4653 return 0;
4654}
4655
4656/**
4657 * smack_secctx_to_secid - return the secid for a smack label
4658 * @secdata: smack label
4659 * @seclen: how long result is
4660 * @secid: outgoing integer
4661 *
4662 * Exists for audit and networking code.
4663 */
4664static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4665{
4666 struct smack_known *skp = smk_find_entry(secdata);
4667
4668 if (skp)
4669 *secid = skp->smk_secid;
4670 else
4671 *secid = 0;
4672 return 0;
4673}
4674
4675/*
4676 * There used to be a smack_release_secctx hook
4677 * that did nothing back when hooks were in a vector.
4678 * Now that there's a list such a hook adds cost.
4679 */
4680
4681static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
4682{
4683 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx,
4684 ctxlen, 0);
4685}
4686
4687static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
4688{
4689 return __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_SMACK,
4690 ctx, ctxlen, 0);
4691}
4692
4693static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
4694{
4695 struct smack_known *skp = smk_of_inode(inode);
4696
4697 *ctx = skp->smk_known;
4698 *ctxlen = strlen(skp->smk_known);
4699 return 0;
4700}
4701
4702static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
4703{
4704
4705 struct task_smack *tsp;
4706 struct smack_known *skp;
4707 struct inode_smack *isp;
4708 struct cred *new_creds = *new;
4709
4710 if (new_creds == NULL) {
4711 new_creds = prepare_creds();
4712 if (new_creds == NULL)
4713 return -ENOMEM;
4714 }
4715
4716 tsp = smack_cred(new_creds);
4717
4718 /*
4719 * Get label from overlay inode and set it in create_sid
4720 */
4721 isp = smack_inode(d_inode(dentry));
4722 skp = isp->smk_inode;
4723 tsp->smk_task = skp;
4724 *new = new_creds;
4725 return 0;
4726}
4727
4728static int smack_inode_copy_up_xattr(const char *name)
4729{
4730 /*
4731 * Return 1 if this is the smack access Smack attribute.
4732 */
4733 if (strcmp(name, XATTR_NAME_SMACK) == 0)
4734 return 1;
4735
4736 return -EOPNOTSUPP;
4737}
4738
4739static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
4740 struct qstr *name,
4741 const struct cred *old,
4742 struct cred *new)
4743{
4744 struct task_smack *otsp = smack_cred(old);
4745 struct task_smack *ntsp = smack_cred(new);
4746 struct inode_smack *isp;
4747 int may;
4748
4749 /*
4750 * Use the process credential unless all of
4751 * the transmuting criteria are met
4752 */
4753 ntsp->smk_task = otsp->smk_task;
4754
4755 /*
4756 * the attribute of the containing directory
4757 */
4758 isp = smack_inode(d_inode(dentry->d_parent));
4759
4760 if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
4761 rcu_read_lock();
4762 may = smk_access_entry(otsp->smk_task->smk_known,
4763 isp->smk_inode->smk_known,
4764 &otsp->smk_task->smk_rules);
4765 rcu_read_unlock();
4766
4767 /*
4768 * If the directory is transmuting and the rule
4769 * providing access is transmuting use the containing
4770 * directory label instead of the process label.
4771 */
4772 if (may > 0 && (may & MAY_TRANSMUTE))
4773 ntsp->smk_task = isp->smk_inode;
4774 }
4775 return 0;
4776}
4777
4778#ifdef CONFIG_IO_URING
4779/**
4780 * smack_uring_override_creds - Is io_uring cred override allowed?
4781 * @new: the target creds
4782 *
4783 * Check to see if the current task is allowed to override it's credentials
4784 * to service an io_uring operation.
4785 */
4786static int smack_uring_override_creds(const struct cred *new)
4787{
4788 struct task_smack *tsp = smack_cred(current_cred());
4789 struct task_smack *nsp = smack_cred(new);
4790
4791 /*
4792 * Allow the degenerate case where the new Smack value is
4793 * the same as the current Smack value.
4794 */
4795 if (tsp->smk_task == nsp->smk_task)
4796 return 0;
4797
4798 if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4799 return 0;
4800
4801 return -EPERM;
4802}
4803
4804/**
4805 * smack_uring_sqpoll - check if a io_uring polling thread can be created
4806 *
4807 * Check to see if the current task is allowed to create a new io_uring
4808 * kernel polling thread.
4809 */
4810static int smack_uring_sqpoll(void)
4811{
4812 if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred()))
4813 return 0;
4814
4815 return -EPERM;
4816}
4817
4818/**
4819 * smack_uring_cmd - check on file operations for io_uring
4820 * @ioucmd: the command in question
4821 *
4822 * Make a best guess about whether a io_uring "command" should
4823 * be allowed. Use the same logic used for determining if the
4824 * file could be opened for read in the absence of better criteria.
4825 */
4826static int smack_uring_cmd(struct io_uring_cmd *ioucmd)
4827{
4828 struct file *file = ioucmd->file;
4829 struct smk_audit_info ad;
4830 struct task_smack *tsp;
4831 struct inode *inode;
4832 int rc;
4833
4834 if (!file)
4835 return -EINVAL;
4836
4837 tsp = smack_cred(file->f_cred);
4838 inode = file_inode(file);
4839
4840 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
4841 smk_ad_setfield_u_fs_path(&ad, file->f_path);
4842 rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
4843 rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
4844
4845 return rc;
4846}
4847
4848#endif /* CONFIG_IO_URING */
4849
4850struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
4851 .lbs_cred = sizeof(struct task_smack),
4852 .lbs_file = sizeof(struct smack_known *),
4853 .lbs_inode = sizeof(struct inode_smack),
4854 .lbs_ipc = sizeof(struct smack_known *),
4855 .lbs_msg_msg = sizeof(struct smack_known *),
4856 .lbs_superblock = sizeof(struct superblock_smack),
4857};
4858
4859static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
4860 LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
4861 LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
4862 LSM_HOOK_INIT(syslog, smack_syslog),
4863
4864 LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
4865 LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
4866
4867 LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
4868 LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
4869 LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
4870 LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
4871 LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
4872
4873 LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec),
4874
4875 LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
4876 LSM_HOOK_INIT(inode_init_security, smack_inode_init_security),
4877 LSM_HOOK_INIT(inode_link, smack_inode_link),
4878 LSM_HOOK_INIT(inode_unlink, smack_inode_unlink),
4879 LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir),
4880 LSM_HOOK_INIT(inode_rename, smack_inode_rename),
4881 LSM_HOOK_INIT(inode_permission, smack_inode_permission),
4882 LSM_HOOK_INIT(inode_setattr, smack_inode_setattr),
4883 LSM_HOOK_INIT(inode_getattr, smack_inode_getattr),
4884 LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr),
4885 LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr),
4886 LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr),
4887 LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr),
4888 LSM_HOOK_INIT(inode_set_acl, smack_inode_set_acl),
4889 LSM_HOOK_INIT(inode_get_acl, smack_inode_get_acl),
4890 LSM_HOOK_INIT(inode_remove_acl, smack_inode_remove_acl),
4891 LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity),
4892 LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity),
4893 LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity),
4894 LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid),
4895
4896 LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security),
4897 LSM_HOOK_INIT(file_ioctl, smack_file_ioctl),
4898 LSM_HOOK_INIT(file_lock, smack_file_lock),
4899 LSM_HOOK_INIT(file_fcntl, smack_file_fcntl),
4900 LSM_HOOK_INIT(mmap_file, smack_mmap_file),
4901 LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
4902 LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner),
4903 LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask),
4904 LSM_HOOK_INIT(file_receive, smack_file_receive),
4905
4906 LSM_HOOK_INIT(file_open, smack_file_open),
4907
4908 LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank),
4909 LSM_HOOK_INIT(cred_free, smack_cred_free),
4910 LSM_HOOK_INIT(cred_prepare, smack_cred_prepare),
4911 LSM_HOOK_INIT(cred_transfer, smack_cred_transfer),
4912 LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid),
4913 LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as),
4914 LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as),
4915 LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
4916 LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
4917 LSM_HOOK_INIT(task_getsid, smack_task_getsid),
4918 LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj),
4919 LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj),
4920 LSM_HOOK_INIT(task_setnice, smack_task_setnice),
4921 LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
4922 LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),
4923 LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler),
4924 LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler),
4925 LSM_HOOK_INIT(task_movememory, smack_task_movememory),
4926 LSM_HOOK_INIT(task_kill, smack_task_kill),
4927 LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),
4928
4929 LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
4930 LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),
4931
4932 LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
4933
4934 LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security),
4935 LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate),
4936 LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl),
4937 LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd),
4938 LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv),
4939
4940 LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security),
4941 LSM_HOOK_INIT(shm_associate, smack_shm_associate),
4942 LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl),
4943 LSM_HOOK_INIT(shm_shmat, smack_shm_shmat),
4944
4945 LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security),
4946 LSM_HOOK_INIT(sem_associate, smack_sem_associate),
4947 LSM_HOOK_INIT(sem_semctl, smack_sem_semctl),
4948 LSM_HOOK_INIT(sem_semop, smack_sem_semop),
4949
4950 LSM_HOOK_INIT(d_instantiate, smack_d_instantiate),
4951
4952 LSM_HOOK_INIT(getprocattr, smack_getprocattr),
4953 LSM_HOOK_INIT(setprocattr, smack_setprocattr),
4954
4955 LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect),
4956 LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
4957
4958 LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
4959 LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair),
4960#ifdef SMACK_IPV6_PORT_LABELING
4961 LSM_HOOK_INIT(socket_bind, smack_socket_bind),
4962#endif
4963 LSM_HOOK_INIT(socket_connect, smack_socket_connect),
4964 LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
4965 LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
4966 LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
4967 LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
4968 LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
4969 LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
4970 LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security),
4971 LSM_HOOK_INIT(sock_graft, smack_sock_graft),
4972 LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
4973 LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
4974
4975 /* key management security hooks */
4976#ifdef CONFIG_KEYS
4977 LSM_HOOK_INIT(key_alloc, smack_key_alloc),
4978 LSM_HOOK_INIT(key_free, smack_key_free),
4979 LSM_HOOK_INIT(key_permission, smack_key_permission),
4980 LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
4981#ifdef CONFIG_KEY_NOTIFICATIONS
4982 LSM_HOOK_INIT(watch_key, smack_watch_key),
4983#endif
4984#endif /* CONFIG_KEYS */
4985
4986#ifdef CONFIG_WATCH_QUEUE
4987 LSM_HOOK_INIT(post_notification, smack_post_notification),
4988#endif
4989
4990 /* Audit hooks */
4991#ifdef CONFIG_AUDIT
4992 LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init),
4993 LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known),
4994 LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match),
4995#endif /* CONFIG_AUDIT */
4996
4997 LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
4998 LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
4999 LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
5000 LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
5001 LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
5002 LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
5003 LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up),
5004 LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr),
5005 LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as),
5006#ifdef CONFIG_IO_URING
5007 LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds),
5008 LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll),
5009 LSM_HOOK_INIT(uring_cmd, smack_uring_cmd),
5010#endif
5011};
5012
5013
5014static __init void init_smack_known_list(void)
5015{
5016 /*
5017 * Initialize rule list locks
5018 */
5019 mutex_init(&smack_known_huh.smk_rules_lock);
5020 mutex_init(&smack_known_hat.smk_rules_lock);
5021 mutex_init(&smack_known_floor.smk_rules_lock);
5022 mutex_init(&smack_known_star.smk_rules_lock);
5023 mutex_init(&smack_known_web.smk_rules_lock);
5024 /*
5025 * Initialize rule lists
5026 */
5027 INIT_LIST_HEAD(&smack_known_huh.smk_rules);
5028 INIT_LIST_HEAD(&smack_known_hat.smk_rules);
5029 INIT_LIST_HEAD(&smack_known_star.smk_rules);
5030 INIT_LIST_HEAD(&smack_known_floor.smk_rules);
5031 INIT_LIST_HEAD(&smack_known_web.smk_rules);
5032 /*
5033 * Create the known labels list
5034 */
5035 smk_insert_entry(&smack_known_huh);
5036 smk_insert_entry(&smack_known_hat);
5037 smk_insert_entry(&smack_known_star);
5038 smk_insert_entry(&smack_known_floor);
5039 smk_insert_entry(&smack_known_web);
5040}
5041
5042/**
5043 * smack_init - initialize the smack system
5044 *
5045 * Returns 0 on success, -ENOMEM is there's no memory
5046 */
5047static __init int smack_init(void)
5048{
5049 struct cred *cred = (struct cred *) current->cred;
5050 struct task_smack *tsp;
5051
5052 smack_rule_cache = KMEM_CACHE(smack_rule, 0);
5053 if (!smack_rule_cache)
5054 return -ENOMEM;
5055
5056 /*
5057 * Set the security state for the initial task.
5058 */
5059 tsp = smack_cred(cred);
5060 init_task_smack(tsp, &smack_known_floor, &smack_known_floor);
5061
5062 /*
5063 * Register with LSM
5064 */
5065 security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
5066 smack_enabled = 1;
5067
5068 pr_info("Smack: Initializing.\n");
5069#ifdef CONFIG_SECURITY_SMACK_NETFILTER
5070 pr_info("Smack: Netfilter enabled.\n");
5071#endif
5072#ifdef SMACK_IPV6_PORT_LABELING
5073 pr_info("Smack: IPv6 port labeling enabled.\n");
5074#endif
5075#ifdef SMACK_IPV6_SECMARK_LABELING
5076 pr_info("Smack: IPv6 Netfilter enabled.\n");
5077#endif
5078
5079 /* initialize the smack_known_list */
5080 init_smack_known_list();
5081
5082 return 0;
5083}
5084
5085/*
5086 * Smack requires early initialization in order to label
5087 * all processes and objects when they are created.
5088 */
5089DEFINE_LSM(smack) = {
5090 .name = "smack",
5091 .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
5092 .blobs = &smack_blob_sizes,
5093 .init = smack_init,
5094};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Simplified MAC Kernel (smack) security module
4 *
5 * This file contains the smack hook function implementations.
6 *
7 * Authors:
8 * Casey Schaufler <casey@schaufler-ca.com>
9 * Jarkko Sakkinen <jarkko.sakkinen@intel.com>
10 *
11 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
12 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
13 * Paul Moore <paul@paul-moore.com>
14 * Copyright (C) 2010 Nokia Corporation
15 * Copyright (C) 2011 Intel Corporation.
16 */
17
18#include <linux/xattr.h>
19#include <linux/pagemap.h>
20#include <linux/mount.h>
21#include <linux/stat.h>
22#include <linux/kd.h>
23#include <asm/ioctls.h>
24#include <linux/ip.h>
25#include <linux/tcp.h>
26#include <linux/udp.h>
27#include <linux/dccp.h>
28#include <linux/icmpv6.h>
29#include <linux/slab.h>
30#include <linux/mutex.h>
31#include <net/cipso_ipv4.h>
32#include <net/ip.h>
33#include <net/ipv6.h>
34#include <linux/audit.h>
35#include <linux/magic.h>
36#include <linux/dcache.h>
37#include <linux/personality.h>
38#include <linux/msg.h>
39#include <linux/shm.h>
40#include <uapi/linux/shm.h>
41#include <linux/binfmts.h>
42#include <linux/parser.h>
43#include <linux/fs_context.h>
44#include <linux/fs_parser.h>
45#include <linux/watch_queue.h>
46#include <linux/io_uring/cmd.h>
47#include <uapi/linux/lsm.h>
48#include "smack.h"
49
50#define TRANS_TRUE "TRUE"
51#define TRANS_TRUE_SIZE 4
52
53#define SMK_CONNECTING 0
54#define SMK_RECEIVING 1
55#define SMK_SENDING 2
56
57/*
58 * Smack uses multiple xattrs.
59 * SMACK64 - for access control,
60 * SMACK64TRANSMUTE - label initialization,
61 * Not saved on files - SMACK64IPIN and SMACK64IPOUT,
62 * Must be set explicitly - SMACK64EXEC and SMACK64MMAP
63 */
64#define SMACK_INODE_INIT_XATTRS 2
65
66#ifdef SMACK_IPV6_PORT_LABELING
67static DEFINE_MUTEX(smack_ipv6_lock);
68static LIST_HEAD(smk_ipv6_port_list);
69#endif
70struct kmem_cache *smack_rule_cache;
71int smack_enabled __initdata;
72
73#define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
74static struct {
75 const char *name;
76 int len;
77 int opt;
78} smk_mount_opts[] = {
79 {"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault},
80 A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute)
81};
82#undef A
83
84static int match_opt_prefix(char *s, int l, char **arg)
85{
86 int i;
87
88 for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) {
89 size_t len = smk_mount_opts[i].len;
90 if (len > l || memcmp(s, smk_mount_opts[i].name, len))
91 continue;
92 if (len == l || s[len] != '=')
93 continue;
94 *arg = s + len + 1;
95 return smk_mount_opts[i].opt;
96 }
97 return Opt_error;
98}
99
100#ifdef CONFIG_SECURITY_SMACK_BRINGUP
101static char *smk_bu_mess[] = {
102 "Bringup Error", /* Unused */
103 "Bringup", /* SMACK_BRINGUP_ALLOW */
104 "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */
105 "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */
106};
107
108static void smk_bu_mode(int mode, char *s)
109{
110 int i = 0;
111
112 if (mode & MAY_READ)
113 s[i++] = 'r';
114 if (mode & MAY_WRITE)
115 s[i++] = 'w';
116 if (mode & MAY_EXEC)
117 s[i++] = 'x';
118 if (mode & MAY_APPEND)
119 s[i++] = 'a';
120 if (mode & MAY_TRANSMUTE)
121 s[i++] = 't';
122 if (mode & MAY_LOCK)
123 s[i++] = 'l';
124 if (i == 0)
125 s[i++] = '-';
126 s[i] = '\0';
127}
128#endif
129
130#ifdef CONFIG_SECURITY_SMACK_BRINGUP
131static int smk_bu_note(char *note, struct smack_known *sskp,
132 struct smack_known *oskp, int mode, int rc)
133{
134 char acc[SMK_NUM_ACCESS_TYPE + 1];
135
136 if (rc <= 0)
137 return rc;
138 if (rc > SMACK_UNCONFINED_OBJECT)
139 rc = 0;
140
141 smk_bu_mode(mode, acc);
142 pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
143 sskp->smk_known, oskp->smk_known, acc, note);
144 return 0;
145}
146#else
147#define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
148#endif
149
150#ifdef CONFIG_SECURITY_SMACK_BRINGUP
151static int smk_bu_current(char *note, struct smack_known *oskp,
152 int mode, int rc)
153{
154 struct task_smack *tsp = smack_cred(current_cred());
155 char acc[SMK_NUM_ACCESS_TYPE + 1];
156
157 if (rc <= 0)
158 return rc;
159 if (rc > SMACK_UNCONFINED_OBJECT)
160 rc = 0;
161
162 smk_bu_mode(mode, acc);
163 pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
164 tsp->smk_task->smk_known, oskp->smk_known,
165 acc, current->comm, note);
166 return 0;
167}
168#else
169#define smk_bu_current(note, oskp, mode, RC) (RC)
170#endif
171
172#ifdef CONFIG_SECURITY_SMACK_BRINGUP
173static int smk_bu_task(struct task_struct *otp, int mode, int rc)
174{
175 struct task_smack *tsp = smack_cred(current_cred());
176 struct smack_known *smk_task = smk_of_task_struct_obj(otp);
177 char acc[SMK_NUM_ACCESS_TYPE + 1];
178
179 if (rc <= 0)
180 return rc;
181 if (rc > SMACK_UNCONFINED_OBJECT)
182 rc = 0;
183
184 smk_bu_mode(mode, acc);
185 pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
186 tsp->smk_task->smk_known, smk_task->smk_known, acc,
187 current->comm, otp->comm);
188 return 0;
189}
190#else
191#define smk_bu_task(otp, mode, RC) (RC)
192#endif
193
194#ifdef CONFIG_SECURITY_SMACK_BRINGUP
195static int smk_bu_inode(struct inode *inode, int mode, int rc)
196{
197 struct task_smack *tsp = smack_cred(current_cred());
198 struct inode_smack *isp = smack_inode(inode);
199 char acc[SMK_NUM_ACCESS_TYPE + 1];
200
201 if (isp->smk_flags & SMK_INODE_IMPURE)
202 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
203 inode->i_sb->s_id, inode->i_ino, current->comm);
204
205 if (rc <= 0)
206 return rc;
207 if (rc > SMACK_UNCONFINED_OBJECT)
208 rc = 0;
209 if (rc == SMACK_UNCONFINED_SUBJECT &&
210 (mode & (MAY_WRITE | MAY_APPEND)))
211 isp->smk_flags |= SMK_INODE_IMPURE;
212
213 smk_bu_mode(mode, acc);
214
215 pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
216 tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
217 inode->i_sb->s_id, inode->i_ino, current->comm);
218 return 0;
219}
220#else
221#define smk_bu_inode(inode, mode, RC) (RC)
222#endif
223
224#ifdef CONFIG_SECURITY_SMACK_BRINGUP
225static int smk_bu_file(struct file *file, int mode, int rc)
226{
227 struct task_smack *tsp = smack_cred(current_cred());
228 struct smack_known *sskp = tsp->smk_task;
229 struct inode *inode = file_inode(file);
230 struct inode_smack *isp = smack_inode(inode);
231 char acc[SMK_NUM_ACCESS_TYPE + 1];
232
233 if (isp->smk_flags & SMK_INODE_IMPURE)
234 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
235 inode->i_sb->s_id, inode->i_ino, current->comm);
236
237 if (rc <= 0)
238 return rc;
239 if (rc > SMACK_UNCONFINED_OBJECT)
240 rc = 0;
241
242 smk_bu_mode(mode, acc);
243 pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
244 sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
245 inode->i_sb->s_id, inode->i_ino, file,
246 current->comm);
247 return 0;
248}
249#else
250#define smk_bu_file(file, mode, RC) (RC)
251#endif
252
253#ifdef CONFIG_SECURITY_SMACK_BRINGUP
254static int smk_bu_credfile(const struct cred *cred, struct file *file,
255 int mode, int rc)
256{
257 struct task_smack *tsp = smack_cred(cred);
258 struct smack_known *sskp = tsp->smk_task;
259 struct inode *inode = file_inode(file);
260 struct inode_smack *isp = smack_inode(inode);
261 char acc[SMK_NUM_ACCESS_TYPE + 1];
262
263 if (isp->smk_flags & SMK_INODE_IMPURE)
264 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
265 inode->i_sb->s_id, inode->i_ino, current->comm);
266
267 if (rc <= 0)
268 return rc;
269 if (rc > SMACK_UNCONFINED_OBJECT)
270 rc = 0;
271
272 smk_bu_mode(mode, acc);
273 pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
274 sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
275 inode->i_sb->s_id, inode->i_ino, file,
276 current->comm);
277 return 0;
278}
279#else
280#define smk_bu_credfile(cred, file, mode, RC) (RC)
281#endif
282
283/**
284 * smk_fetch - Fetch the smack label from a file.
285 * @name: type of the label (attribute)
286 * @ip: a pointer to the inode
287 * @dp: a pointer to the dentry
288 *
289 * Returns a pointer to the master list entry for the Smack label,
290 * NULL if there was no label to fetch, or an error code.
291 */
292static struct smack_known *smk_fetch(const char *name, struct inode *ip,
293 struct dentry *dp)
294{
295 int rc;
296 char *buffer;
297 struct smack_known *skp = NULL;
298
299 if (!(ip->i_opflags & IOP_XATTR))
300 return ERR_PTR(-EOPNOTSUPP);
301
302 buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS);
303 if (buffer == NULL)
304 return ERR_PTR(-ENOMEM);
305
306 rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
307 if (rc < 0)
308 skp = ERR_PTR(rc);
309 else if (rc == 0)
310 skp = NULL;
311 else
312 skp = smk_import_entry(buffer, rc);
313
314 kfree(buffer);
315
316 return skp;
317}
318
319/**
320 * init_inode_smack - initialize an inode security blob
321 * @inode: inode to extract the info from
322 * @skp: a pointer to the Smack label entry to use in the blob
323 *
324 */
325static void init_inode_smack(struct inode *inode, struct smack_known *skp)
326{
327 struct inode_smack *isp = smack_inode(inode);
328
329 isp->smk_inode = skp;
330 isp->smk_flags = 0;
331}
332
333/**
334 * init_task_smack - initialize a task security blob
335 * @tsp: blob to initialize
336 * @task: a pointer to the Smack label for the running task
337 * @forked: a pointer to the Smack label for the forked task
338 *
339 */
340static void init_task_smack(struct task_smack *tsp, struct smack_known *task,
341 struct smack_known *forked)
342{
343 tsp->smk_task = task;
344 tsp->smk_forked = forked;
345 INIT_LIST_HEAD(&tsp->smk_rules);
346 INIT_LIST_HEAD(&tsp->smk_relabel);
347 mutex_init(&tsp->smk_rules_lock);
348}
349
350/**
351 * smk_copy_rules - copy a rule set
352 * @nhead: new rules header pointer
353 * @ohead: old rules header pointer
354 * @gfp: type of the memory for the allocation
355 *
356 * Returns 0 on success, -ENOMEM on error
357 */
358static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
359 gfp_t gfp)
360{
361 struct smack_rule *nrp;
362 struct smack_rule *orp;
363 int rc = 0;
364
365 list_for_each_entry_rcu(orp, ohead, list) {
366 nrp = kmem_cache_zalloc(smack_rule_cache, gfp);
367 if (nrp == NULL) {
368 rc = -ENOMEM;
369 break;
370 }
371 *nrp = *orp;
372 list_add_rcu(&nrp->list, nhead);
373 }
374 return rc;
375}
376
377/**
378 * smk_copy_relabel - copy smk_relabel labels list
379 * @nhead: new rules header pointer
380 * @ohead: old rules header pointer
381 * @gfp: type of the memory for the allocation
382 *
383 * Returns 0 on success, -ENOMEM on error
384 */
385static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
386 gfp_t gfp)
387{
388 struct smack_known_list_elem *nklep;
389 struct smack_known_list_elem *oklep;
390
391 list_for_each_entry(oklep, ohead, list) {
392 nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
393 if (nklep == NULL) {
394 smk_destroy_label_list(nhead);
395 return -ENOMEM;
396 }
397 nklep->smk_label = oklep->smk_label;
398 list_add(&nklep->list, nhead);
399 }
400
401 return 0;
402}
403
404/**
405 * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
406 * @mode: input mode in form of PTRACE_MODE_*
407 *
408 * Returns a converted MAY_* mode usable by smack rules
409 */
410static inline unsigned int smk_ptrace_mode(unsigned int mode)
411{
412 if (mode & PTRACE_MODE_ATTACH)
413 return MAY_READWRITE;
414 if (mode & PTRACE_MODE_READ)
415 return MAY_READ;
416
417 return 0;
418}
419
420/**
421 * smk_ptrace_rule_check - helper for ptrace access
422 * @tracer: tracer process
423 * @tracee_known: label entry of the process that's about to be traced
424 * @mode: ptrace attachment mode (PTRACE_MODE_*)
425 * @func: name of the function that called us, used for audit
426 *
427 * Returns 0 on access granted, -error on error
428 */
429static int smk_ptrace_rule_check(struct task_struct *tracer,
430 struct smack_known *tracee_known,
431 unsigned int mode, const char *func)
432{
433 int rc;
434 struct smk_audit_info ad, *saip = NULL;
435 struct task_smack *tsp;
436 struct smack_known *tracer_known;
437 const struct cred *tracercred;
438
439 if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
440 smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
441 smk_ad_setfield_u_tsk(&ad, tracer);
442 saip = &ad;
443 }
444
445 rcu_read_lock();
446 tracercred = __task_cred(tracer);
447 tsp = smack_cred(tracercred);
448 tracer_known = smk_of_task(tsp);
449
450 if ((mode & PTRACE_MODE_ATTACH) &&
451 (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
452 smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
453 if (tracer_known->smk_known == tracee_known->smk_known)
454 rc = 0;
455 else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
456 rc = -EACCES;
457 else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred))
458 rc = 0;
459 else
460 rc = -EACCES;
461
462 if (saip)
463 smack_log(tracer_known->smk_known,
464 tracee_known->smk_known,
465 0, rc, saip);
466
467 rcu_read_unlock();
468 return rc;
469 }
470
471 /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
472 rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
473
474 rcu_read_unlock();
475 return rc;
476}
477
478/*
479 * LSM hooks.
480 * We he, that is fun!
481 */
482
483/**
484 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
485 * @ctp: child task pointer
486 * @mode: ptrace attachment mode (PTRACE_MODE_*)
487 *
488 * Returns 0 if access is OK, an error code otherwise
489 *
490 * Do the capability checks.
491 */
492static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
493{
494 struct smack_known *skp;
495
496 skp = smk_of_task_struct_obj(ctp);
497
498 return smk_ptrace_rule_check(current, skp, mode, __func__);
499}
500
501/**
502 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
503 * @ptp: parent task pointer
504 *
505 * Returns 0 if access is OK, an error code otherwise
506 *
507 * Do the capability checks, and require PTRACE_MODE_ATTACH.
508 */
509static int smack_ptrace_traceme(struct task_struct *ptp)
510{
511 struct smack_known *skp;
512
513 skp = smk_of_task(smack_cred(current_cred()));
514
515 return smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
516}
517
518/**
519 * smack_syslog - Smack approval on syslog
520 * @typefrom_file: unused
521 *
522 * Returns 0 on success, error code otherwise.
523 */
524static int smack_syslog(int typefrom_file)
525{
526 int rc = 0;
527 struct smack_known *skp = smk_of_current();
528
529 if (smack_privileged(CAP_MAC_OVERRIDE))
530 return 0;
531
532 if (smack_syslog_label != NULL && smack_syslog_label != skp)
533 rc = -EACCES;
534
535 return rc;
536}
537
538/*
539 * Superblock Hooks.
540 */
541
542/**
543 * smack_sb_alloc_security - allocate a superblock blob
544 * @sb: the superblock getting the blob
545 *
546 * Returns 0 on success or -ENOMEM on error.
547 */
548static int smack_sb_alloc_security(struct super_block *sb)
549{
550 struct superblock_smack *sbsp = smack_superblock(sb);
551
552 sbsp->smk_root = &smack_known_floor;
553 sbsp->smk_default = &smack_known_floor;
554 sbsp->smk_floor = &smack_known_floor;
555 sbsp->smk_hat = &smack_known_hat;
556 /*
557 * SMK_SB_INITIALIZED will be zero from kzalloc.
558 */
559
560 return 0;
561}
562
563struct smack_mnt_opts {
564 const char *fsdefault;
565 const char *fsfloor;
566 const char *fshat;
567 const char *fsroot;
568 const char *fstransmute;
569};
570
571static void smack_free_mnt_opts(void *mnt_opts)
572{
573 kfree(mnt_opts);
574}
575
576static int smack_add_opt(int token, const char *s, void **mnt_opts)
577{
578 struct smack_mnt_opts *opts = *mnt_opts;
579 struct smack_known *skp;
580
581 if (!opts) {
582 opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
583 if (!opts)
584 return -ENOMEM;
585 *mnt_opts = opts;
586 }
587 if (!s)
588 return -ENOMEM;
589
590 skp = smk_import_entry(s, 0);
591 if (IS_ERR(skp))
592 return PTR_ERR(skp);
593
594 switch (token) {
595 case Opt_fsdefault:
596 if (opts->fsdefault)
597 goto out_opt_err;
598 opts->fsdefault = skp->smk_known;
599 break;
600 case Opt_fsfloor:
601 if (opts->fsfloor)
602 goto out_opt_err;
603 opts->fsfloor = skp->smk_known;
604 break;
605 case Opt_fshat:
606 if (opts->fshat)
607 goto out_opt_err;
608 opts->fshat = skp->smk_known;
609 break;
610 case Opt_fsroot:
611 if (opts->fsroot)
612 goto out_opt_err;
613 opts->fsroot = skp->smk_known;
614 break;
615 case Opt_fstransmute:
616 if (opts->fstransmute)
617 goto out_opt_err;
618 opts->fstransmute = skp->smk_known;
619 break;
620 }
621 return 0;
622
623out_opt_err:
624 pr_warn("Smack: duplicate mount options\n");
625 return -EINVAL;
626}
627
628/**
629 * smack_fs_context_submount - Initialise security data for a filesystem context
630 * @fc: The filesystem context.
631 * @reference: reference superblock
632 *
633 * Returns 0 on success or -ENOMEM on error.
634 */
635static int smack_fs_context_submount(struct fs_context *fc,
636 struct super_block *reference)
637{
638 struct superblock_smack *sbsp;
639 struct smack_mnt_opts *ctx;
640 struct inode_smack *isp;
641
642 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
643 if (!ctx)
644 return -ENOMEM;
645 fc->security = ctx;
646
647 sbsp = smack_superblock(reference);
648 isp = smack_inode(reference->s_root->d_inode);
649
650 if (sbsp->smk_default) {
651 ctx->fsdefault = kstrdup(sbsp->smk_default->smk_known, GFP_KERNEL);
652 if (!ctx->fsdefault)
653 return -ENOMEM;
654 }
655
656 if (sbsp->smk_floor) {
657 ctx->fsfloor = kstrdup(sbsp->smk_floor->smk_known, GFP_KERNEL);
658 if (!ctx->fsfloor)
659 return -ENOMEM;
660 }
661
662 if (sbsp->smk_hat) {
663 ctx->fshat = kstrdup(sbsp->smk_hat->smk_known, GFP_KERNEL);
664 if (!ctx->fshat)
665 return -ENOMEM;
666 }
667
668 if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
669 if (sbsp->smk_root) {
670 ctx->fstransmute = kstrdup(sbsp->smk_root->smk_known, GFP_KERNEL);
671 if (!ctx->fstransmute)
672 return -ENOMEM;
673 }
674 }
675 return 0;
676}
677
678/**
679 * smack_fs_context_dup - Duplicate the security data on fs_context duplication
680 * @fc: The new filesystem context.
681 * @src_fc: The source filesystem context being duplicated.
682 *
683 * Returns 0 on success or -ENOMEM on error.
684 */
685static int smack_fs_context_dup(struct fs_context *fc,
686 struct fs_context *src_fc)
687{
688 struct smack_mnt_opts *dst, *src = src_fc->security;
689
690 if (!src)
691 return 0;
692
693 fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
694 if (!fc->security)
695 return -ENOMEM;
696
697 dst = fc->security;
698 dst->fsdefault = src->fsdefault;
699 dst->fsfloor = src->fsfloor;
700 dst->fshat = src->fshat;
701 dst->fsroot = src->fsroot;
702 dst->fstransmute = src->fstransmute;
703
704 return 0;
705}
706
707static const struct fs_parameter_spec smack_fs_parameters[] = {
708 fsparam_string("smackfsdef", Opt_fsdefault),
709 fsparam_string("smackfsdefault", Opt_fsdefault),
710 fsparam_string("smackfsfloor", Opt_fsfloor),
711 fsparam_string("smackfshat", Opt_fshat),
712 fsparam_string("smackfsroot", Opt_fsroot),
713 fsparam_string("smackfstransmute", Opt_fstransmute),
714 {}
715};
716
717/**
718 * smack_fs_context_parse_param - Parse a single mount parameter
719 * @fc: The new filesystem context being constructed.
720 * @param: The parameter.
721 *
722 * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on
723 * error.
724 */
725static int smack_fs_context_parse_param(struct fs_context *fc,
726 struct fs_parameter *param)
727{
728 struct fs_parse_result result;
729 int opt, rc;
730
731 opt = fs_parse(fc, smack_fs_parameters, param, &result);
732 if (opt < 0)
733 return opt;
734
735 rc = smack_add_opt(opt, param->string, &fc->security);
736 if (!rc)
737 param->string = NULL;
738 return rc;
739}
740
741static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
742{
743 char *from = options, *to = options;
744 bool first = true;
745
746 while (1) {
747 char *next = strchr(from, ',');
748 int token, len, rc;
749 char *arg = NULL;
750
751 if (next)
752 len = next - from;
753 else
754 len = strlen(from);
755
756 token = match_opt_prefix(from, len, &arg);
757 if (token != Opt_error) {
758 arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
759 rc = smack_add_opt(token, arg, mnt_opts);
760 kfree(arg);
761 if (unlikely(rc)) {
762 if (*mnt_opts)
763 smack_free_mnt_opts(*mnt_opts);
764 *mnt_opts = NULL;
765 return rc;
766 }
767 } else {
768 if (!first) { // copy with preceding comma
769 from--;
770 len++;
771 }
772 if (to != from)
773 memmove(to, from, len);
774 to += len;
775 first = false;
776 }
777 if (!from[len])
778 break;
779 from += len + 1;
780 }
781 *to = '\0';
782 return 0;
783}
784
785/**
786 * smack_set_mnt_opts - set Smack specific mount options
787 * @sb: the file system superblock
788 * @mnt_opts: Smack mount options
789 * @kern_flags: mount option from kernel space or user space
790 * @set_kern_flags: where to store converted mount opts
791 *
792 * Returns 0 on success, an error code on failure
793 *
794 * Allow filesystems with binary mount data to explicitly set Smack mount
795 * labels.
796 */
797static int smack_set_mnt_opts(struct super_block *sb,
798 void *mnt_opts,
799 unsigned long kern_flags,
800 unsigned long *set_kern_flags)
801{
802 struct dentry *root = sb->s_root;
803 struct inode *inode = d_backing_inode(root);
804 struct superblock_smack *sp = smack_superblock(sb);
805 struct inode_smack *isp;
806 struct smack_known *skp;
807 struct smack_mnt_opts *opts = mnt_opts;
808 bool transmute = false;
809
810 if (sp->smk_flags & SMK_SB_INITIALIZED)
811 return 0;
812
813 if (!smack_privileged(CAP_MAC_ADMIN)) {
814 /*
815 * Unprivileged mounts don't get to specify Smack values.
816 */
817 if (opts)
818 return -EPERM;
819 /*
820 * Unprivileged mounts get root and default from the caller.
821 */
822 skp = smk_of_current();
823 sp->smk_root = skp;
824 sp->smk_default = skp;
825 /*
826 * For a handful of fs types with no user-controlled
827 * backing store it's okay to trust security labels
828 * in the filesystem. The rest are untrusted.
829 */
830 if (sb->s_user_ns != &init_user_ns &&
831 sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
832 sb->s_magic != RAMFS_MAGIC) {
833 transmute = true;
834 sp->smk_flags |= SMK_SB_UNTRUSTED;
835 }
836 }
837
838 sp->smk_flags |= SMK_SB_INITIALIZED;
839
840 if (opts) {
841 if (opts->fsdefault) {
842 skp = smk_import_entry(opts->fsdefault, 0);
843 if (IS_ERR(skp))
844 return PTR_ERR(skp);
845 sp->smk_default = skp;
846 }
847 if (opts->fsfloor) {
848 skp = smk_import_entry(opts->fsfloor, 0);
849 if (IS_ERR(skp))
850 return PTR_ERR(skp);
851 sp->smk_floor = skp;
852 }
853 if (opts->fshat) {
854 skp = smk_import_entry(opts->fshat, 0);
855 if (IS_ERR(skp))
856 return PTR_ERR(skp);
857 sp->smk_hat = skp;
858 }
859 if (opts->fsroot) {
860 skp = smk_import_entry(opts->fsroot, 0);
861 if (IS_ERR(skp))
862 return PTR_ERR(skp);
863 sp->smk_root = skp;
864 }
865 if (opts->fstransmute) {
866 skp = smk_import_entry(opts->fstransmute, 0);
867 if (IS_ERR(skp))
868 return PTR_ERR(skp);
869 sp->smk_root = skp;
870 transmute = true;
871 }
872 }
873
874 /*
875 * Initialize the root inode.
876 */
877 init_inode_smack(inode, sp->smk_root);
878
879 if (transmute) {
880 isp = smack_inode(inode);
881 isp->smk_flags |= SMK_INODE_TRANSMUTE;
882 }
883
884 return 0;
885}
886
887/**
888 * smack_sb_statfs - Smack check on statfs
889 * @dentry: identifies the file system in question
890 *
891 * Returns 0 if current can read the floor of the filesystem,
892 * and error code otherwise
893 */
894static int smack_sb_statfs(struct dentry *dentry)
895{
896 struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
897 int rc;
898 struct smk_audit_info ad;
899
900 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
901 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
902
903 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
904 rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
905 return rc;
906}
907
908/*
909 * BPRM hooks
910 */
911
912/**
913 * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec
914 * @bprm: the exec information
915 *
916 * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
917 */
918static int smack_bprm_creds_for_exec(struct linux_binprm *bprm)
919{
920 struct inode *inode = file_inode(bprm->file);
921 struct task_smack *bsp = smack_cred(bprm->cred);
922 struct inode_smack *isp;
923 struct superblock_smack *sbsp;
924 int rc;
925
926 isp = smack_inode(inode);
927 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
928 return 0;
929
930 sbsp = smack_superblock(inode->i_sb);
931 if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
932 isp->smk_task != sbsp->smk_root)
933 return 0;
934
935 if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
936 struct task_struct *tracer;
937 rc = 0;
938
939 rcu_read_lock();
940 tracer = ptrace_parent(current);
941 if (likely(tracer != NULL))
942 rc = smk_ptrace_rule_check(tracer,
943 isp->smk_task,
944 PTRACE_MODE_ATTACH,
945 __func__);
946 rcu_read_unlock();
947
948 if (rc != 0)
949 return rc;
950 }
951 if (bprm->unsafe & ~LSM_UNSAFE_PTRACE)
952 return -EPERM;
953
954 bsp->smk_task = isp->smk_task;
955 bprm->per_clear |= PER_CLEAR_ON_SETID;
956
957 /* Decide if this is a secure exec. */
958 if (bsp->smk_task != bsp->smk_forked)
959 bprm->secureexec = 1;
960
961 return 0;
962}
963
964/*
965 * Inode hooks
966 */
967
968/**
969 * smack_inode_alloc_security - allocate an inode blob
970 * @inode: the inode in need of a blob
971 *
972 * Returns 0
973 */
974static int smack_inode_alloc_security(struct inode *inode)
975{
976 struct smack_known *skp = smk_of_current();
977
978 init_inode_smack(inode, skp);
979 return 0;
980}
981
982/**
983 * smack_inode_init_security - copy out the smack from an inode
984 * @inode: the newly created inode
985 * @dir: containing directory object
986 * @qstr: unused
987 * @xattrs: where to put the attributes
988 * @xattr_count: current number of LSM-provided xattrs (updated)
989 *
990 * Returns 0 if it all works out, -ENOMEM if there's no memory
991 */
992static int smack_inode_init_security(struct inode *inode, struct inode *dir,
993 const struct qstr *qstr,
994 struct xattr *xattrs, int *xattr_count)
995{
996 struct task_smack *tsp = smack_cred(current_cred());
997 struct inode_smack *issp = smack_inode(inode);
998 struct smack_known *skp = smk_of_task(tsp);
999 struct smack_known *isp = smk_of_inode(inode);
1000 struct smack_known *dsp = smk_of_inode(dir);
1001 struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
1002 int may;
1003
1004 /*
1005 * If equal, transmuting already occurred in
1006 * smack_dentry_create_files_as(). No need to check again.
1007 */
1008 if (tsp->smk_task != tsp->smk_transmuted) {
1009 rcu_read_lock();
1010 may = smk_access_entry(skp->smk_known, dsp->smk_known,
1011 &skp->smk_rules);
1012 rcu_read_unlock();
1013 }
1014
1015 /*
1016 * In addition to having smk_task equal to smk_transmuted,
1017 * if the access rule allows transmutation and the directory
1018 * requests transmutation then by all means transmute.
1019 * Mark the inode as changed.
1020 */
1021 if ((tsp->smk_task == tsp->smk_transmuted) ||
1022 (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
1023 smk_inode_transmutable(dir))) {
1024 struct xattr *xattr_transmute;
1025
1026 /*
1027 * The caller of smack_dentry_create_files_as()
1028 * should have overridden the current cred, so the
1029 * inode label was already set correctly in
1030 * smack_inode_alloc_security().
1031 */
1032 if (tsp->smk_task != tsp->smk_transmuted)
1033 isp = issp->smk_inode = dsp;
1034
1035 issp->smk_flags |= SMK_INODE_TRANSMUTE;
1036 xattr_transmute = lsm_get_xattr_slot(xattrs,
1037 xattr_count);
1038 if (xattr_transmute) {
1039 xattr_transmute->value = kmemdup(TRANS_TRUE,
1040 TRANS_TRUE_SIZE,
1041 GFP_NOFS);
1042 if (!xattr_transmute->value)
1043 return -ENOMEM;
1044
1045 xattr_transmute->value_len = TRANS_TRUE_SIZE;
1046 xattr_transmute->name = XATTR_SMACK_TRANSMUTE;
1047 }
1048 }
1049
1050 issp->smk_flags |= SMK_INODE_INSTANT;
1051
1052 if (xattr) {
1053 xattr->value = kstrdup(isp->smk_known, GFP_NOFS);
1054 if (!xattr->value)
1055 return -ENOMEM;
1056
1057 xattr->value_len = strlen(isp->smk_known);
1058 xattr->name = XATTR_SMACK_SUFFIX;
1059 }
1060
1061 return 0;
1062}
1063
1064/**
1065 * smack_inode_link - Smack check on link
1066 * @old_dentry: the existing object
1067 * @dir: unused
1068 * @new_dentry: the new object
1069 *
1070 * Returns 0 if access is permitted, an error code otherwise
1071 */
1072static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
1073 struct dentry *new_dentry)
1074{
1075 struct smack_known *isp;
1076 struct smk_audit_info ad;
1077 int rc;
1078
1079 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1080 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1081
1082 isp = smk_of_inode(d_backing_inode(old_dentry));
1083 rc = smk_curacc(isp, MAY_WRITE, &ad);
1084 rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
1085
1086 if (rc == 0 && d_is_positive(new_dentry)) {
1087 isp = smk_of_inode(d_backing_inode(new_dentry));
1088 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1089 rc = smk_curacc(isp, MAY_WRITE, &ad);
1090 rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
1091 }
1092
1093 return rc;
1094}
1095
1096/**
1097 * smack_inode_unlink - Smack check on inode deletion
1098 * @dir: containing directory object
1099 * @dentry: file to unlink
1100 *
1101 * Returns 0 if current can write the containing directory
1102 * and the object, error code otherwise
1103 */
1104static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
1105{
1106 struct inode *ip = d_backing_inode(dentry);
1107 struct smk_audit_info ad;
1108 int rc;
1109
1110 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1111 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1112
1113 /*
1114 * You need write access to the thing you're unlinking
1115 */
1116 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
1117 rc = smk_bu_inode(ip, MAY_WRITE, rc);
1118 if (rc == 0) {
1119 /*
1120 * You also need write access to the containing directory
1121 */
1122 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1123 smk_ad_setfield_u_fs_inode(&ad, dir);
1124 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1125 rc = smk_bu_inode(dir, MAY_WRITE, rc);
1126 }
1127 return rc;
1128}
1129
1130/**
1131 * smack_inode_rmdir - Smack check on directory deletion
1132 * @dir: containing directory object
1133 * @dentry: directory to unlink
1134 *
1135 * Returns 0 if current can write the containing directory
1136 * and the directory, error code otherwise
1137 */
1138static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
1139{
1140 struct smk_audit_info ad;
1141 int rc;
1142
1143 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1144 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1145
1146 /*
1147 * You need write access to the thing you're removing
1148 */
1149 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1150 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1151 if (rc == 0) {
1152 /*
1153 * You also need write access to the containing directory
1154 */
1155 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1156 smk_ad_setfield_u_fs_inode(&ad, dir);
1157 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1158 rc = smk_bu_inode(dir, MAY_WRITE, rc);
1159 }
1160
1161 return rc;
1162}
1163
1164/**
1165 * smack_inode_rename - Smack check on rename
1166 * @old_inode: unused
1167 * @old_dentry: the old object
1168 * @new_inode: unused
1169 * @new_dentry: the new object
1170 *
1171 * Read and write access is required on both the old and
1172 * new directories.
1173 *
1174 * Returns 0 if access is permitted, an error code otherwise
1175 */
1176static int smack_inode_rename(struct inode *old_inode,
1177 struct dentry *old_dentry,
1178 struct inode *new_inode,
1179 struct dentry *new_dentry)
1180{
1181 int rc;
1182 struct smack_known *isp;
1183 struct smk_audit_info ad;
1184
1185 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1186 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1187
1188 isp = smk_of_inode(d_backing_inode(old_dentry));
1189 rc = smk_curacc(isp, MAY_READWRITE, &ad);
1190 rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
1191
1192 if (rc == 0 && d_is_positive(new_dentry)) {
1193 isp = smk_of_inode(d_backing_inode(new_dentry));
1194 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1195 rc = smk_curacc(isp, MAY_READWRITE, &ad);
1196 rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
1197 }
1198 return rc;
1199}
1200
1201/**
1202 * smack_inode_permission - Smack version of permission()
1203 * @inode: the inode in question
1204 * @mask: the access requested
1205 *
1206 * This is the important Smack hook.
1207 *
1208 * Returns 0 if access is permitted, an error code otherwise
1209 */
1210static int smack_inode_permission(struct inode *inode, int mask)
1211{
1212 struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
1213 struct smk_audit_info ad;
1214 int no_block = mask & MAY_NOT_BLOCK;
1215 int rc;
1216
1217 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
1218 /*
1219 * No permission to check. Existence test. Yup, it's there.
1220 */
1221 if (mask == 0)
1222 return 0;
1223
1224 if (sbsp->smk_flags & SMK_SB_UNTRUSTED) {
1225 if (smk_of_inode(inode) != sbsp->smk_root)
1226 return -EACCES;
1227 }
1228
1229 /* May be droppable after audit */
1230 if (no_block)
1231 return -ECHILD;
1232 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1233 smk_ad_setfield_u_fs_inode(&ad, inode);
1234 rc = smk_curacc(smk_of_inode(inode), mask, &ad);
1235 rc = smk_bu_inode(inode, mask, rc);
1236 return rc;
1237}
1238
1239/**
1240 * smack_inode_setattr - Smack check for setting attributes
1241 * @idmap: idmap of the mount
1242 * @dentry: the object
1243 * @iattr: for the force flag
1244 *
1245 * Returns 0 if access is permitted, an error code otherwise
1246 */
1247static int smack_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
1248 struct iattr *iattr)
1249{
1250 struct smk_audit_info ad;
1251 int rc;
1252
1253 /*
1254 * Need to allow for clearing the setuid bit.
1255 */
1256 if (iattr->ia_valid & ATTR_FORCE)
1257 return 0;
1258 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1259 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1260
1261 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1262 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1263 return rc;
1264}
1265
1266/**
1267 * smack_inode_getattr - Smack check for getting attributes
1268 * @path: path to extract the info from
1269 *
1270 * Returns 0 if access is permitted, an error code otherwise
1271 */
1272static int smack_inode_getattr(const struct path *path)
1273{
1274 struct smk_audit_info ad;
1275 struct inode *inode = d_backing_inode(path->dentry);
1276 int rc;
1277
1278 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1279 smk_ad_setfield_u_fs_path(&ad, *path);
1280 rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1281 rc = smk_bu_inode(inode, MAY_READ, rc);
1282 return rc;
1283}
1284
1285/**
1286 * smack_inode_setxattr - Smack check for setting xattrs
1287 * @idmap: idmap of the mount
1288 * @dentry: the object
1289 * @name: name of the attribute
1290 * @value: value of the attribute
1291 * @size: size of the value
1292 * @flags: unused
1293 *
1294 * This protects the Smack attribute explicitly.
1295 *
1296 * Returns 0 if access is permitted, an error code otherwise
1297 */
1298static int smack_inode_setxattr(struct mnt_idmap *idmap,
1299 struct dentry *dentry, const char *name,
1300 const void *value, size_t size, int flags)
1301{
1302 struct smk_audit_info ad;
1303 struct smack_known *skp;
1304 int check_priv = 0;
1305 int check_import = 0;
1306 int check_star = 0;
1307 int rc = 0;
1308
1309 /*
1310 * Check label validity here so import won't fail in post_setxattr
1311 */
1312 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1313 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1314 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
1315 check_priv = 1;
1316 check_import = 1;
1317 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1318 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1319 check_priv = 1;
1320 check_import = 1;
1321 check_star = 1;
1322 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1323 check_priv = 1;
1324 if (!S_ISDIR(d_backing_inode(dentry)->i_mode) ||
1325 size != TRANS_TRUE_SIZE ||
1326 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
1327 rc = -EINVAL;
1328 } else
1329 rc = cap_inode_setxattr(dentry, name, value, size, flags);
1330
1331 if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
1332 rc = -EPERM;
1333
1334 if (rc == 0 && check_import) {
1335 skp = size ? smk_import_entry(value, size) : NULL;
1336 if (IS_ERR(skp))
1337 rc = PTR_ERR(skp);
1338 else if (skp == NULL || (check_star &&
1339 (skp == &smack_known_star || skp == &smack_known_web)))
1340 rc = -EINVAL;
1341 }
1342
1343 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1344 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1345
1346 if (rc == 0) {
1347 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1348 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1349 }
1350
1351 return rc;
1352}
1353
1354/**
1355 * smack_inode_post_setxattr - Apply the Smack update approved above
1356 * @dentry: object
1357 * @name: attribute name
1358 * @value: attribute value
1359 * @size: attribute size
1360 * @flags: unused
1361 *
1362 * Set the pointer in the inode blob to the entry found
1363 * in the master label list.
1364 */
1365static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
1366 const void *value, size_t size, int flags)
1367{
1368 struct smack_known *skp;
1369 struct inode_smack *isp = smack_inode(d_backing_inode(dentry));
1370
1371 if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1372 isp->smk_flags |= SMK_INODE_TRANSMUTE;
1373 return;
1374 }
1375
1376 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1377 skp = smk_import_entry(value, size);
1378 if (!IS_ERR(skp))
1379 isp->smk_inode = skp;
1380 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1381 skp = smk_import_entry(value, size);
1382 if (!IS_ERR(skp))
1383 isp->smk_task = skp;
1384 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1385 skp = smk_import_entry(value, size);
1386 if (!IS_ERR(skp))
1387 isp->smk_mmap = skp;
1388 }
1389
1390 return;
1391}
1392
1393/**
1394 * smack_inode_getxattr - Smack check on getxattr
1395 * @dentry: the object
1396 * @name: unused
1397 *
1398 * Returns 0 if access is permitted, an error code otherwise
1399 */
1400static int smack_inode_getxattr(struct dentry *dentry, const char *name)
1401{
1402 struct smk_audit_info ad;
1403 int rc;
1404
1405 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1406 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1407
1408 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1409 rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1410 return rc;
1411}
1412
1413/**
1414 * smack_inode_removexattr - Smack check on removexattr
1415 * @idmap: idmap of the mount
1416 * @dentry: the object
1417 * @name: name of the attribute
1418 *
1419 * Removing the Smack attribute requires CAP_MAC_ADMIN
1420 *
1421 * Returns 0 if access is permitted, an error code otherwise
1422 */
1423static int smack_inode_removexattr(struct mnt_idmap *idmap,
1424 struct dentry *dentry, const char *name)
1425{
1426 struct inode_smack *isp;
1427 struct smk_audit_info ad;
1428 int rc = 0;
1429
1430 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1431 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1432 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1433 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1434 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
1435 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1436 if (!smack_privileged(CAP_MAC_ADMIN))
1437 rc = -EPERM;
1438 } else
1439 rc = cap_inode_removexattr(idmap, dentry, name);
1440
1441 if (rc != 0)
1442 return rc;
1443
1444 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1445 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1446
1447 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1448 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1449 if (rc != 0)
1450 return rc;
1451
1452 isp = smack_inode(d_backing_inode(dentry));
1453 /*
1454 * Don't do anything special for these.
1455 * XATTR_NAME_SMACKIPIN
1456 * XATTR_NAME_SMACKIPOUT
1457 */
1458 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1459 struct super_block *sbp = dentry->d_sb;
1460 struct superblock_smack *sbsp = smack_superblock(sbp);
1461
1462 isp->smk_inode = sbsp->smk_default;
1463 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
1464 isp->smk_task = NULL;
1465 else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1466 isp->smk_mmap = NULL;
1467 else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
1468 isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1469
1470 return 0;
1471}
1472
1473/**
1474 * smack_inode_set_acl - Smack check for setting posix acls
1475 * @idmap: idmap of the mnt this request came from
1476 * @dentry: the object
1477 * @acl_name: name of the posix acl
1478 * @kacl: the posix acls
1479 *
1480 * Returns 0 if access is permitted, an error code otherwise
1481 */
1482static int smack_inode_set_acl(struct mnt_idmap *idmap,
1483 struct dentry *dentry, const char *acl_name,
1484 struct posix_acl *kacl)
1485{
1486 struct smk_audit_info ad;
1487 int rc;
1488
1489 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1490 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1491
1492 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1493 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1494 return rc;
1495}
1496
1497/**
1498 * smack_inode_get_acl - Smack check for getting posix acls
1499 * @idmap: idmap of the mnt this request came from
1500 * @dentry: the object
1501 * @acl_name: name of the posix acl
1502 *
1503 * Returns 0 if access is permitted, an error code otherwise
1504 */
1505static int smack_inode_get_acl(struct mnt_idmap *idmap,
1506 struct dentry *dentry, const char *acl_name)
1507{
1508 struct smk_audit_info ad;
1509 int rc;
1510
1511 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1512 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1513
1514 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1515 rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1516 return rc;
1517}
1518
1519/**
1520 * smack_inode_remove_acl - Smack check for getting posix acls
1521 * @idmap: idmap of the mnt this request came from
1522 * @dentry: the object
1523 * @acl_name: name of the posix acl
1524 *
1525 * Returns 0 if access is permitted, an error code otherwise
1526 */
1527static int smack_inode_remove_acl(struct mnt_idmap *idmap,
1528 struct dentry *dentry, const char *acl_name)
1529{
1530 struct smk_audit_info ad;
1531 int rc;
1532
1533 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1534 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1535
1536 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1537 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1538 return rc;
1539}
1540
1541/**
1542 * smack_inode_getsecurity - get smack xattrs
1543 * @idmap: idmap of the mount
1544 * @inode: the object
1545 * @name: attribute name
1546 * @buffer: where to put the result
1547 * @alloc: duplicate memory
1548 *
1549 * Returns the size of the attribute or an error code
1550 */
1551static int smack_inode_getsecurity(struct mnt_idmap *idmap,
1552 struct inode *inode, const char *name,
1553 void **buffer, bool alloc)
1554{
1555 struct socket_smack *ssp;
1556 struct socket *sock;
1557 struct super_block *sbp;
1558 struct inode *ip = inode;
1559 struct smack_known *isp;
1560 struct inode_smack *ispp;
1561 size_t label_len;
1562 char *label = NULL;
1563
1564 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1565 isp = smk_of_inode(inode);
1566 } else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) {
1567 ispp = smack_inode(inode);
1568 if (ispp->smk_flags & SMK_INODE_TRANSMUTE)
1569 label = TRANS_TRUE;
1570 else
1571 label = "";
1572 } else {
1573 /*
1574 * The rest of the Smack xattrs are only on sockets.
1575 */
1576 sbp = ip->i_sb;
1577 if (sbp->s_magic != SOCKFS_MAGIC)
1578 return -EOPNOTSUPP;
1579
1580 sock = SOCKET_I(ip);
1581 if (sock == NULL || sock->sk == NULL)
1582 return -EOPNOTSUPP;
1583
1584 ssp = sock->sk->sk_security;
1585
1586 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1587 isp = ssp->smk_in;
1588 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1589 isp = ssp->smk_out;
1590 else
1591 return -EOPNOTSUPP;
1592 }
1593
1594 if (!label)
1595 label = isp->smk_known;
1596
1597 label_len = strlen(label);
1598
1599 if (alloc) {
1600 *buffer = kstrdup(label, GFP_KERNEL);
1601 if (*buffer == NULL)
1602 return -ENOMEM;
1603 }
1604
1605 return label_len;
1606}
1607
1608
1609/**
1610 * smack_inode_listsecurity - list the Smack attributes
1611 * @inode: the object
1612 * @buffer: where they go
1613 * @buffer_size: size of buffer
1614 */
1615static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1616 size_t buffer_size)
1617{
1618 int len = sizeof(XATTR_NAME_SMACK);
1619
1620 if (buffer != NULL && len <= buffer_size)
1621 memcpy(buffer, XATTR_NAME_SMACK, len);
1622
1623 return len;
1624}
1625
1626/**
1627 * smack_inode_getsecid - Extract inode's security id
1628 * @inode: inode to extract the info from
1629 * @secid: where result will be saved
1630 */
1631static void smack_inode_getsecid(struct inode *inode, u32 *secid)
1632{
1633 struct smack_known *skp = smk_of_inode(inode);
1634
1635 *secid = skp->smk_secid;
1636}
1637
1638/*
1639 * File Hooks
1640 */
1641
1642/*
1643 * There is no smack_file_permission hook
1644 *
1645 * Should access checks be done on each read or write?
1646 * UNICOS and SELinux say yes.
1647 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1648 *
1649 * I'll say no for now. Smack does not do the frequent
1650 * label changing that SELinux does.
1651 */
1652
1653/**
1654 * smack_file_alloc_security - assign a file security blob
1655 * @file: the object
1656 *
1657 * The security blob for a file is a pointer to the master
1658 * label list, so no allocation is done.
1659 *
1660 * f_security is the owner security information. It
1661 * isn't used on file access checks, it's for send_sigio.
1662 *
1663 * Returns 0
1664 */
1665static int smack_file_alloc_security(struct file *file)
1666{
1667 struct smack_known **blob = smack_file(file);
1668
1669 *blob = smk_of_current();
1670 return 0;
1671}
1672
1673/**
1674 * smack_file_ioctl - Smack check on ioctls
1675 * @file: the object
1676 * @cmd: what to do
1677 * @arg: unused
1678 *
1679 * Relies heavily on the correct use of the ioctl command conventions.
1680 *
1681 * Returns 0 if allowed, error code otherwise
1682 */
1683static int smack_file_ioctl(struct file *file, unsigned int cmd,
1684 unsigned long arg)
1685{
1686 int rc = 0;
1687 struct smk_audit_info ad;
1688 struct inode *inode = file_inode(file);
1689
1690 if (unlikely(IS_PRIVATE(inode)))
1691 return 0;
1692
1693 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1694 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1695
1696 if (_IOC_DIR(cmd) & _IOC_WRITE) {
1697 rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1698 rc = smk_bu_file(file, MAY_WRITE, rc);
1699 }
1700
1701 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
1702 rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1703 rc = smk_bu_file(file, MAY_READ, rc);
1704 }
1705
1706 return rc;
1707}
1708
1709/**
1710 * smack_file_lock - Smack check on file locking
1711 * @file: the object
1712 * @cmd: unused
1713 *
1714 * Returns 0 if current has lock access, error code otherwise
1715 */
1716static int smack_file_lock(struct file *file, unsigned int cmd)
1717{
1718 struct smk_audit_info ad;
1719 int rc;
1720 struct inode *inode = file_inode(file);
1721
1722 if (unlikely(IS_PRIVATE(inode)))
1723 return 0;
1724
1725 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1726 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1727 rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1728 rc = smk_bu_file(file, MAY_LOCK, rc);
1729 return rc;
1730}
1731
1732/**
1733 * smack_file_fcntl - Smack check on fcntl
1734 * @file: the object
1735 * @cmd: what action to check
1736 * @arg: unused
1737 *
1738 * Generally these operations are harmless.
1739 * File locking operations present an obvious mechanism
1740 * for passing information, so they require write access.
1741 *
1742 * Returns 0 if current has access, error code otherwise
1743 */
1744static int smack_file_fcntl(struct file *file, unsigned int cmd,
1745 unsigned long arg)
1746{
1747 struct smk_audit_info ad;
1748 int rc = 0;
1749 struct inode *inode = file_inode(file);
1750
1751 if (unlikely(IS_PRIVATE(inode)))
1752 return 0;
1753
1754 switch (cmd) {
1755 case F_GETLK:
1756 break;
1757 case F_SETLK:
1758 case F_SETLKW:
1759 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1760 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1761 rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1762 rc = smk_bu_file(file, MAY_LOCK, rc);
1763 break;
1764 case F_SETOWN:
1765 case F_SETSIG:
1766 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1767 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1768 rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1769 rc = smk_bu_file(file, MAY_WRITE, rc);
1770 break;
1771 default:
1772 break;
1773 }
1774
1775 return rc;
1776}
1777
1778/**
1779 * smack_mmap_file - Check permissions for a mmap operation.
1780 * @file: contains the file structure for file to map (may be NULL).
1781 * @reqprot: contains the protection requested by the application.
1782 * @prot: contains the protection that will be applied by the kernel.
1783 * @flags: contains the operational flags.
1784 *
1785 * The @file may be NULL, e.g. if mapping anonymous memory.
1786 *
1787 * Return 0 if permission is granted.
1788 */
1789static int smack_mmap_file(struct file *file,
1790 unsigned long reqprot, unsigned long prot,
1791 unsigned long flags)
1792{
1793 struct smack_known *skp;
1794 struct smack_known *mkp;
1795 struct smack_rule *srp;
1796 struct task_smack *tsp;
1797 struct smack_known *okp;
1798 struct inode_smack *isp;
1799 struct superblock_smack *sbsp;
1800 int may;
1801 int mmay;
1802 int tmay;
1803 int rc;
1804
1805 if (file == NULL)
1806 return 0;
1807
1808 if (unlikely(IS_PRIVATE(file_inode(file))))
1809 return 0;
1810
1811 isp = smack_inode(file_inode(file));
1812 if (isp->smk_mmap == NULL)
1813 return 0;
1814 sbsp = smack_superblock(file_inode(file)->i_sb);
1815 if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
1816 isp->smk_mmap != sbsp->smk_root)
1817 return -EACCES;
1818 mkp = isp->smk_mmap;
1819
1820 tsp = smack_cred(current_cred());
1821 skp = smk_of_current();
1822 rc = 0;
1823
1824 rcu_read_lock();
1825 /*
1826 * For each Smack rule associated with the subject
1827 * label verify that the SMACK64MMAP also has access
1828 * to that rule's object label.
1829 */
1830 list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1831 okp = srp->smk_object;
1832 /*
1833 * Matching labels always allows access.
1834 */
1835 if (mkp->smk_known == okp->smk_known)
1836 continue;
1837 /*
1838 * If there is a matching local rule take
1839 * that into account as well.
1840 */
1841 may = smk_access_entry(srp->smk_subject->smk_known,
1842 okp->smk_known,
1843 &tsp->smk_rules);
1844 if (may == -ENOENT)
1845 may = srp->smk_access;
1846 else
1847 may &= srp->smk_access;
1848 /*
1849 * If may is zero the SMACK64MMAP subject can't
1850 * possibly have less access.
1851 */
1852 if (may == 0)
1853 continue;
1854
1855 /*
1856 * Fetch the global list entry.
1857 * If there isn't one a SMACK64MMAP subject
1858 * can't have as much access as current.
1859 */
1860 mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1861 &mkp->smk_rules);
1862 if (mmay == -ENOENT) {
1863 rc = -EACCES;
1864 break;
1865 }
1866 /*
1867 * If there is a local entry it modifies the
1868 * potential access, too.
1869 */
1870 tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1871 &tsp->smk_rules);
1872 if (tmay != -ENOENT)
1873 mmay &= tmay;
1874
1875 /*
1876 * If there is any access available to current that is
1877 * not available to a SMACK64MMAP subject
1878 * deny access.
1879 */
1880 if ((may | mmay) != mmay) {
1881 rc = -EACCES;
1882 break;
1883 }
1884 }
1885
1886 rcu_read_unlock();
1887
1888 return rc;
1889}
1890
1891/**
1892 * smack_file_set_fowner - set the file security blob value
1893 * @file: object in question
1894 *
1895 */
1896static void smack_file_set_fowner(struct file *file)
1897{
1898 struct smack_known **blob = smack_file(file);
1899
1900 *blob = smk_of_current();
1901}
1902
1903/**
1904 * smack_file_send_sigiotask - Smack on sigio
1905 * @tsk: The target task
1906 * @fown: the object the signal come from
1907 * @signum: unused
1908 *
1909 * Allow a privileged task to get signals even if it shouldn't
1910 *
1911 * Returns 0 if a subject with the object's smack could
1912 * write to the task, an error code otherwise.
1913 */
1914static int smack_file_send_sigiotask(struct task_struct *tsk,
1915 struct fown_struct *fown, int signum)
1916{
1917 struct smack_known **blob;
1918 struct smack_known *skp;
1919 struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred));
1920 const struct cred *tcred;
1921 struct file *file;
1922 int rc;
1923 struct smk_audit_info ad;
1924
1925 /*
1926 * struct fown_struct is never outside the context of a struct file
1927 */
1928 file = container_of(fown, struct file, f_owner);
1929
1930 /* we don't log here as rc can be overriden */
1931 blob = smack_file(file);
1932 skp = *blob;
1933 rc = smk_access(skp, tkp, MAY_DELIVER, NULL);
1934 rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc);
1935
1936 rcu_read_lock();
1937 tcred = __task_cred(tsk);
1938 if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred))
1939 rc = 0;
1940 rcu_read_unlock();
1941
1942 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1943 smk_ad_setfield_u_tsk(&ad, tsk);
1944 smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad);
1945 return rc;
1946}
1947
1948/**
1949 * smack_file_receive - Smack file receive check
1950 * @file: the object
1951 *
1952 * Returns 0 if current has access, error code otherwise
1953 */
1954static int smack_file_receive(struct file *file)
1955{
1956 int rc;
1957 int may = 0;
1958 struct smk_audit_info ad;
1959 struct inode *inode = file_inode(file);
1960 struct socket *sock;
1961 struct task_smack *tsp;
1962 struct socket_smack *ssp;
1963
1964 if (unlikely(IS_PRIVATE(inode)))
1965 return 0;
1966
1967 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1968 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1969
1970 if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
1971 sock = SOCKET_I(inode);
1972 ssp = sock->sk->sk_security;
1973 tsp = smack_cred(current_cred());
1974 /*
1975 * If the receiving process can't write to the
1976 * passed socket or if the passed socket can't
1977 * write to the receiving process don't accept
1978 * the passed socket.
1979 */
1980 rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad);
1981 rc = smk_bu_file(file, may, rc);
1982 if (rc < 0)
1983 return rc;
1984 rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad);
1985 rc = smk_bu_file(file, may, rc);
1986 return rc;
1987 }
1988 /*
1989 * This code relies on bitmasks.
1990 */
1991 if (file->f_mode & FMODE_READ)
1992 may = MAY_READ;
1993 if (file->f_mode & FMODE_WRITE)
1994 may |= MAY_WRITE;
1995
1996 rc = smk_curacc(smk_of_inode(inode), may, &ad);
1997 rc = smk_bu_file(file, may, rc);
1998 return rc;
1999}
2000
2001/**
2002 * smack_file_open - Smack dentry open processing
2003 * @file: the object
2004 *
2005 * Set the security blob in the file structure.
2006 * Allow the open only if the task has read access. There are
2007 * many read operations (e.g. fstat) that you can do with an
2008 * fd even if you have the file open write-only.
2009 *
2010 * Returns 0 if current has access, error code otherwise
2011 */
2012static int smack_file_open(struct file *file)
2013{
2014 struct task_smack *tsp = smack_cred(file->f_cred);
2015 struct inode *inode = file_inode(file);
2016 struct smk_audit_info ad;
2017 int rc;
2018
2019 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
2020 smk_ad_setfield_u_fs_path(&ad, file->f_path);
2021 rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
2022 rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
2023
2024 return rc;
2025}
2026
2027/*
2028 * Task hooks
2029 */
2030
2031/**
2032 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
2033 * @cred: the new credentials
2034 * @gfp: the atomicity of any memory allocations
2035 *
2036 * Prepare a blank set of credentials for modification. This must allocate all
2037 * the memory the LSM module might require such that cred_transfer() can
2038 * complete without error.
2039 */
2040static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
2041{
2042 init_task_smack(smack_cred(cred), NULL, NULL);
2043 return 0;
2044}
2045
2046
2047/**
2048 * smack_cred_free - "free" task-level security credentials
2049 * @cred: the credentials in question
2050 *
2051 */
2052static void smack_cred_free(struct cred *cred)
2053{
2054 struct task_smack *tsp = smack_cred(cred);
2055 struct smack_rule *rp;
2056 struct list_head *l;
2057 struct list_head *n;
2058
2059 smk_destroy_label_list(&tsp->smk_relabel);
2060
2061 list_for_each_safe(l, n, &tsp->smk_rules) {
2062 rp = list_entry(l, struct smack_rule, list);
2063 list_del(&rp->list);
2064 kmem_cache_free(smack_rule_cache, rp);
2065 }
2066}
2067
2068/**
2069 * smack_cred_prepare - prepare new set of credentials for modification
2070 * @new: the new credentials
2071 * @old: the original credentials
2072 * @gfp: the atomicity of any memory allocations
2073 *
2074 * Prepare a new set of credentials for modification.
2075 */
2076static int smack_cred_prepare(struct cred *new, const struct cred *old,
2077 gfp_t gfp)
2078{
2079 struct task_smack *old_tsp = smack_cred(old);
2080 struct task_smack *new_tsp = smack_cred(new);
2081 int rc;
2082
2083 init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
2084
2085 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
2086 if (rc != 0)
2087 return rc;
2088
2089 rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
2090 gfp);
2091 return rc;
2092}
2093
2094/**
2095 * smack_cred_transfer - Transfer the old credentials to the new credentials
2096 * @new: the new credentials
2097 * @old: the original credentials
2098 *
2099 * Fill in a set of blank credentials from another set of credentials.
2100 */
2101static void smack_cred_transfer(struct cred *new, const struct cred *old)
2102{
2103 struct task_smack *old_tsp = smack_cred(old);
2104 struct task_smack *new_tsp = smack_cred(new);
2105
2106 init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
2107}
2108
2109/**
2110 * smack_cred_getsecid - get the secid corresponding to a creds structure
2111 * @cred: the object creds
2112 * @secid: where to put the result
2113 *
2114 * Sets the secid to contain a u32 version of the smack label.
2115 */
2116static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
2117{
2118 struct smack_known *skp;
2119
2120 rcu_read_lock();
2121 skp = smk_of_task(smack_cred(cred));
2122 *secid = skp->smk_secid;
2123 rcu_read_unlock();
2124}
2125
2126/**
2127 * smack_kernel_act_as - Set the subjective context in a set of credentials
2128 * @new: points to the set of credentials to be modified.
2129 * @secid: specifies the security ID to be set
2130 *
2131 * Set the security data for a kernel service.
2132 */
2133static int smack_kernel_act_as(struct cred *new, u32 secid)
2134{
2135 struct task_smack *new_tsp = smack_cred(new);
2136
2137 new_tsp->smk_task = smack_from_secid(secid);
2138 return 0;
2139}
2140
2141/**
2142 * smack_kernel_create_files_as - Set the file creation label in a set of creds
2143 * @new: points to the set of credentials to be modified
2144 * @inode: points to the inode to use as a reference
2145 *
2146 * Set the file creation context in a set of credentials to the same
2147 * as the objective context of the specified inode
2148 */
2149static int smack_kernel_create_files_as(struct cred *new,
2150 struct inode *inode)
2151{
2152 struct inode_smack *isp = smack_inode(inode);
2153 struct task_smack *tsp = smack_cred(new);
2154
2155 tsp->smk_forked = isp->smk_inode;
2156 tsp->smk_task = tsp->smk_forked;
2157 return 0;
2158}
2159
2160/**
2161 * smk_curacc_on_task - helper to log task related access
2162 * @p: the task object
2163 * @access: the access requested
2164 * @caller: name of the calling function for audit
2165 *
2166 * Return 0 if access is permitted
2167 */
2168static int smk_curacc_on_task(struct task_struct *p, int access,
2169 const char *caller)
2170{
2171 struct smk_audit_info ad;
2172 struct smack_known *skp = smk_of_task_struct_obj(p);
2173 int rc;
2174
2175 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
2176 smk_ad_setfield_u_tsk(&ad, p);
2177 rc = smk_curacc(skp, access, &ad);
2178 rc = smk_bu_task(p, access, rc);
2179 return rc;
2180}
2181
2182/**
2183 * smack_task_setpgid - Smack check on setting pgid
2184 * @p: the task object
2185 * @pgid: unused
2186 *
2187 * Return 0 if write access is permitted
2188 */
2189static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
2190{
2191 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2192}
2193
2194/**
2195 * smack_task_getpgid - Smack access check for getpgid
2196 * @p: the object task
2197 *
2198 * Returns 0 if current can read the object task, error code otherwise
2199 */
2200static int smack_task_getpgid(struct task_struct *p)
2201{
2202 return smk_curacc_on_task(p, MAY_READ, __func__);
2203}
2204
2205/**
2206 * smack_task_getsid - Smack access check for getsid
2207 * @p: the object task
2208 *
2209 * Returns 0 if current can read the object task, error code otherwise
2210 */
2211static int smack_task_getsid(struct task_struct *p)
2212{
2213 return smk_curacc_on_task(p, MAY_READ, __func__);
2214}
2215
2216/**
2217 * smack_current_getsecid_subj - get the subjective secid of the current task
2218 * @secid: where to put the result
2219 *
2220 * Sets the secid to contain a u32 version of the task's subjective smack label.
2221 */
2222static void smack_current_getsecid_subj(u32 *secid)
2223{
2224 struct smack_known *skp = smk_of_current();
2225
2226 *secid = skp->smk_secid;
2227}
2228
2229/**
2230 * smack_task_getsecid_obj - get the objective secid of the task
2231 * @p: the task
2232 * @secid: where to put the result
2233 *
2234 * Sets the secid to contain a u32 version of the task's objective smack label.
2235 */
2236static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid)
2237{
2238 struct smack_known *skp = smk_of_task_struct_obj(p);
2239
2240 *secid = skp->smk_secid;
2241}
2242
2243/**
2244 * smack_task_setnice - Smack check on setting nice
2245 * @p: the task object
2246 * @nice: unused
2247 *
2248 * Return 0 if write access is permitted
2249 */
2250static int smack_task_setnice(struct task_struct *p, int nice)
2251{
2252 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2253}
2254
2255/**
2256 * smack_task_setioprio - Smack check on setting ioprio
2257 * @p: the task object
2258 * @ioprio: unused
2259 *
2260 * Return 0 if write access is permitted
2261 */
2262static int smack_task_setioprio(struct task_struct *p, int ioprio)
2263{
2264 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2265}
2266
2267/**
2268 * smack_task_getioprio - Smack check on reading ioprio
2269 * @p: the task object
2270 *
2271 * Return 0 if read access is permitted
2272 */
2273static int smack_task_getioprio(struct task_struct *p)
2274{
2275 return smk_curacc_on_task(p, MAY_READ, __func__);
2276}
2277
2278/**
2279 * smack_task_setscheduler - Smack check on setting scheduler
2280 * @p: the task object
2281 *
2282 * Return 0 if read access is permitted
2283 */
2284static int smack_task_setscheduler(struct task_struct *p)
2285{
2286 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2287}
2288
2289/**
2290 * smack_task_getscheduler - Smack check on reading scheduler
2291 * @p: the task object
2292 *
2293 * Return 0 if read access is permitted
2294 */
2295static int smack_task_getscheduler(struct task_struct *p)
2296{
2297 return smk_curacc_on_task(p, MAY_READ, __func__);
2298}
2299
2300/**
2301 * smack_task_movememory - Smack check on moving memory
2302 * @p: the task object
2303 *
2304 * Return 0 if write access is permitted
2305 */
2306static int smack_task_movememory(struct task_struct *p)
2307{
2308 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2309}
2310
2311/**
2312 * smack_task_kill - Smack check on signal delivery
2313 * @p: the task object
2314 * @info: unused
2315 * @sig: unused
2316 * @cred: identifies the cred to use in lieu of current's
2317 *
2318 * Return 0 if write access is permitted
2319 *
2320 */
2321static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
2322 int sig, const struct cred *cred)
2323{
2324 struct smk_audit_info ad;
2325 struct smack_known *skp;
2326 struct smack_known *tkp = smk_of_task_struct_obj(p);
2327 int rc;
2328
2329 if (!sig)
2330 return 0; /* null signal; existence test */
2331
2332 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
2333 smk_ad_setfield_u_tsk(&ad, p);
2334 /*
2335 * Sending a signal requires that the sender
2336 * can write the receiver.
2337 */
2338 if (cred == NULL) {
2339 rc = smk_curacc(tkp, MAY_DELIVER, &ad);
2340 rc = smk_bu_task(p, MAY_DELIVER, rc);
2341 return rc;
2342 }
2343 /*
2344 * If the cred isn't NULL we're dealing with some USB IO
2345 * specific behavior. This is not clean. For one thing
2346 * we can't take privilege into account.
2347 */
2348 skp = smk_of_task(smack_cred(cred));
2349 rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
2350 rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
2351 return rc;
2352}
2353
2354/**
2355 * smack_task_to_inode - copy task smack into the inode blob
2356 * @p: task to copy from
2357 * @inode: inode to copy to
2358 *
2359 * Sets the smack pointer in the inode security blob
2360 */
2361static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
2362{
2363 struct inode_smack *isp = smack_inode(inode);
2364 struct smack_known *skp = smk_of_task_struct_obj(p);
2365
2366 isp->smk_inode = skp;
2367 isp->smk_flags |= SMK_INODE_INSTANT;
2368}
2369
2370/*
2371 * Socket hooks.
2372 */
2373
2374/**
2375 * smack_sk_alloc_security - Allocate a socket blob
2376 * @sk: the socket
2377 * @family: unused
2378 * @gfp_flags: memory allocation flags
2379 *
2380 * Assign Smack pointers to current
2381 *
2382 * Returns 0 on success, -ENOMEM is there's no memory
2383 */
2384static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
2385{
2386 struct smack_known *skp = smk_of_current();
2387 struct socket_smack *ssp;
2388
2389 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
2390 if (ssp == NULL)
2391 return -ENOMEM;
2392
2393 /*
2394 * Sockets created by kernel threads receive web label.
2395 */
2396 if (unlikely(current->flags & PF_KTHREAD)) {
2397 ssp->smk_in = &smack_known_web;
2398 ssp->smk_out = &smack_known_web;
2399 } else {
2400 ssp->smk_in = skp;
2401 ssp->smk_out = skp;
2402 }
2403 ssp->smk_packet = NULL;
2404
2405 sk->sk_security = ssp;
2406
2407 return 0;
2408}
2409
2410/**
2411 * smack_sk_free_security - Free a socket blob
2412 * @sk: the socket
2413 *
2414 * Clears the blob pointer
2415 */
2416static void smack_sk_free_security(struct sock *sk)
2417{
2418#ifdef SMACK_IPV6_PORT_LABELING
2419 struct smk_port_label *spp;
2420
2421 if (sk->sk_family == PF_INET6) {
2422 rcu_read_lock();
2423 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2424 if (spp->smk_sock != sk)
2425 continue;
2426 spp->smk_can_reuse = 1;
2427 break;
2428 }
2429 rcu_read_unlock();
2430 }
2431#endif
2432 kfree(sk->sk_security);
2433}
2434
2435/**
2436 * smack_sk_clone_security - Copy security context
2437 * @sk: the old socket
2438 * @newsk: the new socket
2439 *
2440 * Copy the security context of the old socket pointer to the cloned
2441 */
2442static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk)
2443{
2444 struct socket_smack *ssp_old = sk->sk_security;
2445 struct socket_smack *ssp_new = newsk->sk_security;
2446
2447 *ssp_new = *ssp_old;
2448}
2449
2450/**
2451* smack_ipv4host_label - check host based restrictions
2452* @sip: the object end
2453*
2454* looks for host based access restrictions
2455*
2456* This version will only be appropriate for really small sets of single label
2457* hosts. The caller is responsible for ensuring that the RCU read lock is
2458* taken before calling this function.
2459*
2460* Returns the label of the far end or NULL if it's not special.
2461*/
2462static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
2463{
2464 struct smk_net4addr *snp;
2465 struct in_addr *siap = &sip->sin_addr;
2466
2467 if (siap->s_addr == 0)
2468 return NULL;
2469
2470 list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
2471 /*
2472 * we break after finding the first match because
2473 * the list is sorted from longest to shortest mask
2474 * so we have found the most specific match
2475 */
2476 if (snp->smk_host.s_addr ==
2477 (siap->s_addr & snp->smk_mask.s_addr))
2478 return snp->smk_label;
2479
2480 return NULL;
2481}
2482
2483/*
2484 * smk_ipv6_localhost - Check for local ipv6 host address
2485 * @sip: the address
2486 *
2487 * Returns boolean true if this is the localhost address
2488 */
2489static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
2490{
2491 __be16 *be16p = (__be16 *)&sip->sin6_addr;
2492 __be32 *be32p = (__be32 *)&sip->sin6_addr;
2493
2494 if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
2495 ntohs(be16p[7]) == 1)
2496 return true;
2497 return false;
2498}
2499
2500/**
2501* smack_ipv6host_label - check host based restrictions
2502* @sip: the object end
2503*
2504* looks for host based access restrictions
2505*
2506* This version will only be appropriate for really small sets of single label
2507* hosts. The caller is responsible for ensuring that the RCU read lock is
2508* taken before calling this function.
2509*
2510* Returns the label of the far end or NULL if it's not special.
2511*/
2512static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
2513{
2514 struct smk_net6addr *snp;
2515 struct in6_addr *sap = &sip->sin6_addr;
2516 int i;
2517 int found = 0;
2518
2519 /*
2520 * It's local. Don't look for a host label.
2521 */
2522 if (smk_ipv6_localhost(sip))
2523 return NULL;
2524
2525 list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
2526 /*
2527 * If the label is NULL the entry has
2528 * been renounced. Ignore it.
2529 */
2530 if (snp->smk_label == NULL)
2531 continue;
2532 /*
2533 * we break after finding the first match because
2534 * the list is sorted from longest to shortest mask
2535 * so we have found the most specific match
2536 */
2537 for (found = 1, i = 0; i < 8; i++) {
2538 if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
2539 snp->smk_host.s6_addr16[i]) {
2540 found = 0;
2541 break;
2542 }
2543 }
2544 if (found)
2545 return snp->smk_label;
2546 }
2547
2548 return NULL;
2549}
2550
2551/**
2552 * smack_netlbl_add - Set the secattr on a socket
2553 * @sk: the socket
2554 *
2555 * Attach the outbound smack value (smk_out) to the socket.
2556 *
2557 * Returns 0 on success or an error code
2558 */
2559static int smack_netlbl_add(struct sock *sk)
2560{
2561 struct socket_smack *ssp = sk->sk_security;
2562 struct smack_known *skp = ssp->smk_out;
2563 int rc;
2564
2565 local_bh_disable();
2566 bh_lock_sock_nested(sk);
2567
2568 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2569 switch (rc) {
2570 case 0:
2571 ssp->smk_state = SMK_NETLBL_LABELED;
2572 break;
2573 case -EDESTADDRREQ:
2574 ssp->smk_state = SMK_NETLBL_REQSKB;
2575 rc = 0;
2576 break;
2577 }
2578
2579 bh_unlock_sock(sk);
2580 local_bh_enable();
2581
2582 return rc;
2583}
2584
2585/**
2586 * smack_netlbl_delete - Remove the secattr from a socket
2587 * @sk: the socket
2588 *
2589 * Remove the outbound smack value from a socket
2590 */
2591static void smack_netlbl_delete(struct sock *sk)
2592{
2593 struct socket_smack *ssp = sk->sk_security;
2594
2595 /*
2596 * Take the label off the socket if one is set.
2597 */
2598 if (ssp->smk_state != SMK_NETLBL_LABELED)
2599 return;
2600
2601 local_bh_disable();
2602 bh_lock_sock_nested(sk);
2603 netlbl_sock_delattr(sk);
2604 bh_unlock_sock(sk);
2605 local_bh_enable();
2606 ssp->smk_state = SMK_NETLBL_UNLABELED;
2607}
2608
2609/**
2610 * smk_ipv4_check - Perform IPv4 host access checks
2611 * @sk: the socket
2612 * @sap: the destination address
2613 *
2614 * Set the correct secattr for the given socket based on the destination
2615 * address and perform any outbound access checks needed.
2616 *
2617 * Returns 0 on success or an error code.
2618 *
2619 */
2620static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
2621{
2622 struct smack_known *skp;
2623 int rc = 0;
2624 struct smack_known *hkp;
2625 struct socket_smack *ssp = sk->sk_security;
2626 struct smk_audit_info ad;
2627
2628 rcu_read_lock();
2629 hkp = smack_ipv4host_label(sap);
2630 if (hkp != NULL) {
2631#ifdef CONFIG_AUDIT
2632 struct lsm_network_audit net;
2633
2634 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2635 ad.a.u.net->family = sap->sin_family;
2636 ad.a.u.net->dport = sap->sin_port;
2637 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
2638#endif
2639 skp = ssp->smk_out;
2640 rc = smk_access(skp, hkp, MAY_WRITE, &ad);
2641 rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2642 /*
2643 * Clear the socket netlabel if it's set.
2644 */
2645 if (!rc)
2646 smack_netlbl_delete(sk);
2647 }
2648 rcu_read_unlock();
2649
2650 return rc;
2651}
2652
2653/**
2654 * smk_ipv6_check - check Smack access
2655 * @subject: subject Smack label
2656 * @object: object Smack label
2657 * @address: address
2658 * @act: the action being taken
2659 *
2660 * Check an IPv6 access
2661 */
2662static int smk_ipv6_check(struct smack_known *subject,
2663 struct smack_known *object,
2664 struct sockaddr_in6 *address, int act)
2665{
2666#ifdef CONFIG_AUDIT
2667 struct lsm_network_audit net;
2668#endif
2669 struct smk_audit_info ad;
2670 int rc;
2671
2672#ifdef CONFIG_AUDIT
2673 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2674 ad.a.u.net->family = PF_INET6;
2675 ad.a.u.net->dport = address->sin6_port;
2676 if (act == SMK_RECEIVING)
2677 ad.a.u.net->v6info.saddr = address->sin6_addr;
2678 else
2679 ad.a.u.net->v6info.daddr = address->sin6_addr;
2680#endif
2681 rc = smk_access(subject, object, MAY_WRITE, &ad);
2682 rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
2683 return rc;
2684}
2685
2686#ifdef SMACK_IPV6_PORT_LABELING
2687/**
2688 * smk_ipv6_port_label - Smack port access table management
2689 * @sock: socket
2690 * @address: address
2691 *
2692 * Create or update the port list entry
2693 */
2694static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
2695{
2696 struct sock *sk = sock->sk;
2697 struct sockaddr_in6 *addr6;
2698 struct socket_smack *ssp = sock->sk->sk_security;
2699 struct smk_port_label *spp;
2700 unsigned short port = 0;
2701
2702 if (address == NULL) {
2703 /*
2704 * This operation is changing the Smack information
2705 * on the bound socket. Take the changes to the port
2706 * as well.
2707 */
2708 rcu_read_lock();
2709 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2710 if (sk != spp->smk_sock)
2711 continue;
2712 spp->smk_in = ssp->smk_in;
2713 spp->smk_out = ssp->smk_out;
2714 rcu_read_unlock();
2715 return;
2716 }
2717 /*
2718 * A NULL address is only used for updating existing
2719 * bound entries. If there isn't one, it's OK.
2720 */
2721 rcu_read_unlock();
2722 return;
2723 }
2724
2725 addr6 = (struct sockaddr_in6 *)address;
2726 port = ntohs(addr6->sin6_port);
2727 /*
2728 * This is a special case that is safely ignored.
2729 */
2730 if (port == 0)
2731 return;
2732
2733 /*
2734 * Look for an existing port list entry.
2735 * This is an indication that a port is getting reused.
2736 */
2737 rcu_read_lock();
2738 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2739 if (spp->smk_port != port || spp->smk_sock_type != sock->type)
2740 continue;
2741 if (spp->smk_can_reuse != 1) {
2742 rcu_read_unlock();
2743 return;
2744 }
2745 spp->smk_port = port;
2746 spp->smk_sock = sk;
2747 spp->smk_in = ssp->smk_in;
2748 spp->smk_out = ssp->smk_out;
2749 spp->smk_can_reuse = 0;
2750 rcu_read_unlock();
2751 return;
2752 }
2753 rcu_read_unlock();
2754 /*
2755 * A new port entry is required.
2756 */
2757 spp = kzalloc(sizeof(*spp), GFP_KERNEL);
2758 if (spp == NULL)
2759 return;
2760
2761 spp->smk_port = port;
2762 spp->smk_sock = sk;
2763 spp->smk_in = ssp->smk_in;
2764 spp->smk_out = ssp->smk_out;
2765 spp->smk_sock_type = sock->type;
2766 spp->smk_can_reuse = 0;
2767
2768 mutex_lock(&smack_ipv6_lock);
2769 list_add_rcu(&spp->list, &smk_ipv6_port_list);
2770 mutex_unlock(&smack_ipv6_lock);
2771 return;
2772}
2773
2774/**
2775 * smk_ipv6_port_check - check Smack port access
2776 * @sk: socket
2777 * @address: address
2778 * @act: the action being taken
2779 *
2780 * Create or update the port list entry
2781 */
2782static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2783 int act)
2784{
2785 struct smk_port_label *spp;
2786 struct socket_smack *ssp = sk->sk_security;
2787 struct smack_known *skp = NULL;
2788 unsigned short port;
2789 struct smack_known *object;
2790
2791 if (act == SMK_RECEIVING) {
2792 skp = smack_ipv6host_label(address);
2793 object = ssp->smk_in;
2794 } else {
2795 skp = ssp->smk_out;
2796 object = smack_ipv6host_label(address);
2797 }
2798
2799 /*
2800 * The other end is a single label host.
2801 */
2802 if (skp != NULL && object != NULL)
2803 return smk_ipv6_check(skp, object, address, act);
2804 if (skp == NULL)
2805 skp = smack_net_ambient;
2806 if (object == NULL)
2807 object = smack_net_ambient;
2808
2809 /*
2810 * It's remote, so port lookup does no good.
2811 */
2812 if (!smk_ipv6_localhost(address))
2813 return smk_ipv6_check(skp, object, address, act);
2814
2815 /*
2816 * It's local so the send check has to have passed.
2817 */
2818 if (act == SMK_RECEIVING)
2819 return 0;
2820
2821 port = ntohs(address->sin6_port);
2822 rcu_read_lock();
2823 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2824 if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type)
2825 continue;
2826 object = spp->smk_in;
2827 if (act == SMK_CONNECTING)
2828 ssp->smk_packet = spp->smk_out;
2829 break;
2830 }
2831 rcu_read_unlock();
2832
2833 return smk_ipv6_check(skp, object, address, act);
2834}
2835#endif
2836
2837/**
2838 * smack_inode_setsecurity - set smack xattrs
2839 * @inode: the object
2840 * @name: attribute name
2841 * @value: attribute value
2842 * @size: size of the attribute
2843 * @flags: unused
2844 *
2845 * Sets the named attribute in the appropriate blob
2846 *
2847 * Returns 0 on success, or an error code
2848 */
2849static int smack_inode_setsecurity(struct inode *inode, const char *name,
2850 const void *value, size_t size, int flags)
2851{
2852 struct smack_known *skp;
2853 struct inode_smack *nsp = smack_inode(inode);
2854 struct socket_smack *ssp;
2855 struct socket *sock;
2856 int rc = 0;
2857
2858 if (value == NULL || size > SMK_LONGLABEL || size == 0)
2859 return -EINVAL;
2860
2861 if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) {
2862 if (!S_ISDIR(inode->i_mode) || size != TRANS_TRUE_SIZE ||
2863 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
2864 return -EINVAL;
2865
2866 nsp->smk_flags |= SMK_INODE_TRANSMUTE;
2867 return 0;
2868 }
2869
2870 skp = smk_import_entry(value, size);
2871 if (IS_ERR(skp))
2872 return PTR_ERR(skp);
2873
2874 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2875 nsp->smk_inode = skp;
2876 nsp->smk_flags |= SMK_INODE_INSTANT;
2877 return 0;
2878 }
2879 /*
2880 * The rest of the Smack xattrs are only on sockets.
2881 */
2882 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
2883 return -EOPNOTSUPP;
2884
2885 sock = SOCKET_I(inode);
2886 if (sock == NULL || sock->sk == NULL)
2887 return -EOPNOTSUPP;
2888
2889 ssp = sock->sk->sk_security;
2890
2891 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2892 ssp->smk_in = skp;
2893 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2894 ssp->smk_out = skp;
2895 if (sock->sk->sk_family == PF_INET) {
2896 rc = smack_netlbl_add(sock->sk);
2897 if (rc != 0)
2898 printk(KERN_WARNING
2899 "Smack: \"%s\" netlbl error %d.\n",
2900 __func__, -rc);
2901 }
2902 } else
2903 return -EOPNOTSUPP;
2904
2905#ifdef SMACK_IPV6_PORT_LABELING
2906 if (sock->sk->sk_family == PF_INET6)
2907 smk_ipv6_port_label(sock, NULL);
2908#endif
2909
2910 return 0;
2911}
2912
2913/**
2914 * smack_socket_post_create - finish socket setup
2915 * @sock: the socket
2916 * @family: protocol family
2917 * @type: unused
2918 * @protocol: unused
2919 * @kern: unused
2920 *
2921 * Sets the netlabel information on the socket
2922 *
2923 * Returns 0 on success, and error code otherwise
2924 */
2925static int smack_socket_post_create(struct socket *sock, int family,
2926 int type, int protocol, int kern)
2927{
2928 struct socket_smack *ssp;
2929
2930 if (sock->sk == NULL)
2931 return 0;
2932
2933 /*
2934 * Sockets created by kernel threads receive web label.
2935 */
2936 if (unlikely(current->flags & PF_KTHREAD)) {
2937 ssp = sock->sk->sk_security;
2938 ssp->smk_in = &smack_known_web;
2939 ssp->smk_out = &smack_known_web;
2940 }
2941
2942 if (family != PF_INET)
2943 return 0;
2944 /*
2945 * Set the outbound netlbl.
2946 */
2947 return smack_netlbl_add(sock->sk);
2948}
2949
2950/**
2951 * smack_socket_socketpair - create socket pair
2952 * @socka: one socket
2953 * @sockb: another socket
2954 *
2955 * Cross reference the peer labels for SO_PEERSEC
2956 *
2957 * Returns 0
2958 */
2959static int smack_socket_socketpair(struct socket *socka,
2960 struct socket *sockb)
2961{
2962 struct socket_smack *asp = socka->sk->sk_security;
2963 struct socket_smack *bsp = sockb->sk->sk_security;
2964
2965 asp->smk_packet = bsp->smk_out;
2966 bsp->smk_packet = asp->smk_out;
2967
2968 return 0;
2969}
2970
2971#ifdef SMACK_IPV6_PORT_LABELING
2972/**
2973 * smack_socket_bind - record port binding information.
2974 * @sock: the socket
2975 * @address: the port address
2976 * @addrlen: size of the address
2977 *
2978 * Records the label bound to a port.
2979 *
2980 * Returns 0 on success, and error code otherwise
2981 */
2982static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
2983 int addrlen)
2984{
2985 if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) {
2986 if (addrlen < SIN6_LEN_RFC2133 ||
2987 address->sa_family != AF_INET6)
2988 return -EINVAL;
2989 smk_ipv6_port_label(sock, address);
2990 }
2991 return 0;
2992}
2993#endif /* SMACK_IPV6_PORT_LABELING */
2994
2995/**
2996 * smack_socket_connect - connect access check
2997 * @sock: the socket
2998 * @sap: the other end
2999 * @addrlen: size of sap
3000 *
3001 * Verifies that a connection may be possible
3002 *
3003 * Returns 0 on success, and error code otherwise
3004 */
3005static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
3006 int addrlen)
3007{
3008 int rc = 0;
3009
3010 if (sock->sk == NULL)
3011 return 0;
3012 if (sock->sk->sk_family != PF_INET &&
3013 (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6))
3014 return 0;
3015 if (addrlen < offsetofend(struct sockaddr, sa_family))
3016 return 0;
3017 if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) {
3018 struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
3019 struct smack_known *rsp = NULL;
3020
3021 if (addrlen < SIN6_LEN_RFC2133)
3022 return 0;
3023 if (__is_defined(SMACK_IPV6_SECMARK_LABELING))
3024 rsp = smack_ipv6host_label(sip);
3025 if (rsp != NULL) {
3026 struct socket_smack *ssp = sock->sk->sk_security;
3027
3028 rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
3029 SMK_CONNECTING);
3030 }
3031#ifdef SMACK_IPV6_PORT_LABELING
3032 rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
3033#endif
3034
3035 return rc;
3036 }
3037 if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
3038 return 0;
3039 rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap);
3040 return rc;
3041}
3042
3043/**
3044 * smack_flags_to_may - convert S_ to MAY_ values
3045 * @flags: the S_ value
3046 *
3047 * Returns the equivalent MAY_ value
3048 */
3049static int smack_flags_to_may(int flags)
3050{
3051 int may = 0;
3052
3053 if (flags & S_IRUGO)
3054 may |= MAY_READ;
3055 if (flags & S_IWUGO)
3056 may |= MAY_WRITE;
3057 if (flags & S_IXUGO)
3058 may |= MAY_EXEC;
3059
3060 return may;
3061}
3062
3063/**
3064 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
3065 * @msg: the object
3066 *
3067 * Returns 0
3068 */
3069static int smack_msg_msg_alloc_security(struct msg_msg *msg)
3070{
3071 struct smack_known **blob = smack_msg_msg(msg);
3072
3073 *blob = smk_of_current();
3074 return 0;
3075}
3076
3077/**
3078 * smack_of_ipc - the smack pointer for the ipc
3079 * @isp: the object
3080 *
3081 * Returns a pointer to the smack value
3082 */
3083static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp)
3084{
3085 struct smack_known **blob = smack_ipc(isp);
3086
3087 return *blob;
3088}
3089
3090/**
3091 * smack_ipc_alloc_security - Set the security blob for ipc
3092 * @isp: the object
3093 *
3094 * Returns 0
3095 */
3096static int smack_ipc_alloc_security(struct kern_ipc_perm *isp)
3097{
3098 struct smack_known **blob = smack_ipc(isp);
3099
3100 *blob = smk_of_current();
3101 return 0;
3102}
3103
3104/**
3105 * smk_curacc_shm : check if current has access on shm
3106 * @isp : the object
3107 * @access : access requested
3108 *
3109 * Returns 0 if current has the requested access, error code otherwise
3110 */
3111static int smk_curacc_shm(struct kern_ipc_perm *isp, int access)
3112{
3113 struct smack_known *ssp = smack_of_ipc(isp);
3114 struct smk_audit_info ad;
3115 int rc;
3116
3117#ifdef CONFIG_AUDIT
3118 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3119 ad.a.u.ipc_id = isp->id;
3120#endif
3121 rc = smk_curacc(ssp, access, &ad);
3122 rc = smk_bu_current("shm", ssp, access, rc);
3123 return rc;
3124}
3125
3126/**
3127 * smack_shm_associate - Smack access check for shm
3128 * @isp: the object
3129 * @shmflg: access requested
3130 *
3131 * Returns 0 if current has the requested access, error code otherwise
3132 */
3133static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg)
3134{
3135 int may;
3136
3137 may = smack_flags_to_may(shmflg);
3138 return smk_curacc_shm(isp, may);
3139}
3140
3141/**
3142 * smack_shm_shmctl - Smack access check for shm
3143 * @isp: the object
3144 * @cmd: what it wants to do
3145 *
3146 * Returns 0 if current has the requested access, error code otherwise
3147 */
3148static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd)
3149{
3150 int may;
3151
3152 switch (cmd) {
3153 case IPC_STAT:
3154 case SHM_STAT:
3155 case SHM_STAT_ANY:
3156 may = MAY_READ;
3157 break;
3158 case IPC_SET:
3159 case SHM_LOCK:
3160 case SHM_UNLOCK:
3161 case IPC_RMID:
3162 may = MAY_READWRITE;
3163 break;
3164 case IPC_INFO:
3165 case SHM_INFO:
3166 /*
3167 * System level information.
3168 */
3169 return 0;
3170 default:
3171 return -EINVAL;
3172 }
3173 return smk_curacc_shm(isp, may);
3174}
3175
3176/**
3177 * smack_shm_shmat - Smack access for shmat
3178 * @isp: the object
3179 * @shmaddr: unused
3180 * @shmflg: access requested
3181 *
3182 * Returns 0 if current has the requested access, error code otherwise
3183 */
3184static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr,
3185 int shmflg)
3186{
3187 int may;
3188
3189 may = smack_flags_to_may(shmflg);
3190 return smk_curacc_shm(isp, may);
3191}
3192
3193/**
3194 * smk_curacc_sem : check if current has access on sem
3195 * @isp : the object
3196 * @access : access requested
3197 *
3198 * Returns 0 if current has the requested access, error code otherwise
3199 */
3200static int smk_curacc_sem(struct kern_ipc_perm *isp, int access)
3201{
3202 struct smack_known *ssp = smack_of_ipc(isp);
3203 struct smk_audit_info ad;
3204 int rc;
3205
3206#ifdef CONFIG_AUDIT
3207 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3208 ad.a.u.ipc_id = isp->id;
3209#endif
3210 rc = smk_curacc(ssp, access, &ad);
3211 rc = smk_bu_current("sem", ssp, access, rc);
3212 return rc;
3213}
3214
3215/**
3216 * smack_sem_associate - Smack access check for sem
3217 * @isp: the object
3218 * @semflg: access requested
3219 *
3220 * Returns 0 if current has the requested access, error code otherwise
3221 */
3222static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg)
3223{
3224 int may;
3225
3226 may = smack_flags_to_may(semflg);
3227 return smk_curacc_sem(isp, may);
3228}
3229
3230/**
3231 * smack_sem_semctl - Smack access check for sem
3232 * @isp: the object
3233 * @cmd: what it wants to do
3234 *
3235 * Returns 0 if current has the requested access, error code otherwise
3236 */
3237static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd)
3238{
3239 int may;
3240
3241 switch (cmd) {
3242 case GETPID:
3243 case GETNCNT:
3244 case GETZCNT:
3245 case GETVAL:
3246 case GETALL:
3247 case IPC_STAT:
3248 case SEM_STAT:
3249 case SEM_STAT_ANY:
3250 may = MAY_READ;
3251 break;
3252 case SETVAL:
3253 case SETALL:
3254 case IPC_RMID:
3255 case IPC_SET:
3256 may = MAY_READWRITE;
3257 break;
3258 case IPC_INFO:
3259 case SEM_INFO:
3260 /*
3261 * System level information
3262 */
3263 return 0;
3264 default:
3265 return -EINVAL;
3266 }
3267
3268 return smk_curacc_sem(isp, may);
3269}
3270
3271/**
3272 * smack_sem_semop - Smack checks of semaphore operations
3273 * @isp: the object
3274 * @sops: unused
3275 * @nsops: unused
3276 * @alter: unused
3277 *
3278 * Treated as read and write in all cases.
3279 *
3280 * Returns 0 if access is allowed, error code otherwise
3281 */
3282static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops,
3283 unsigned nsops, int alter)
3284{
3285 return smk_curacc_sem(isp, MAY_READWRITE);
3286}
3287
3288/**
3289 * smk_curacc_msq : helper to check if current has access on msq
3290 * @isp : the msq
3291 * @access : access requested
3292 *
3293 * return 0 if current has access, error otherwise
3294 */
3295static int smk_curacc_msq(struct kern_ipc_perm *isp, int access)
3296{
3297 struct smack_known *msp = smack_of_ipc(isp);
3298 struct smk_audit_info ad;
3299 int rc;
3300
3301#ifdef CONFIG_AUDIT
3302 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3303 ad.a.u.ipc_id = isp->id;
3304#endif
3305 rc = smk_curacc(msp, access, &ad);
3306 rc = smk_bu_current("msq", msp, access, rc);
3307 return rc;
3308}
3309
3310/**
3311 * smack_msg_queue_associate - Smack access check for msg_queue
3312 * @isp: the object
3313 * @msqflg: access requested
3314 *
3315 * Returns 0 if current has the requested access, error code otherwise
3316 */
3317static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg)
3318{
3319 int may;
3320
3321 may = smack_flags_to_may(msqflg);
3322 return smk_curacc_msq(isp, may);
3323}
3324
3325/**
3326 * smack_msg_queue_msgctl - Smack access check for msg_queue
3327 * @isp: the object
3328 * @cmd: what it wants to do
3329 *
3330 * Returns 0 if current has the requested access, error code otherwise
3331 */
3332static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd)
3333{
3334 int may;
3335
3336 switch (cmd) {
3337 case IPC_STAT:
3338 case MSG_STAT:
3339 case MSG_STAT_ANY:
3340 may = MAY_READ;
3341 break;
3342 case IPC_SET:
3343 case IPC_RMID:
3344 may = MAY_READWRITE;
3345 break;
3346 case IPC_INFO:
3347 case MSG_INFO:
3348 /*
3349 * System level information
3350 */
3351 return 0;
3352 default:
3353 return -EINVAL;
3354 }
3355
3356 return smk_curacc_msq(isp, may);
3357}
3358
3359/**
3360 * smack_msg_queue_msgsnd - Smack access check for msg_queue
3361 * @isp: the object
3362 * @msg: unused
3363 * @msqflg: access requested
3364 *
3365 * Returns 0 if current has the requested access, error code otherwise
3366 */
3367static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg,
3368 int msqflg)
3369{
3370 int may;
3371
3372 may = smack_flags_to_may(msqflg);
3373 return smk_curacc_msq(isp, may);
3374}
3375
3376/**
3377 * smack_msg_queue_msgrcv - Smack access check for msg_queue
3378 * @isp: the object
3379 * @msg: unused
3380 * @target: unused
3381 * @type: unused
3382 * @mode: unused
3383 *
3384 * Returns 0 if current has read and write access, error code otherwise
3385 */
3386static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp,
3387 struct msg_msg *msg,
3388 struct task_struct *target, long type,
3389 int mode)
3390{
3391 return smk_curacc_msq(isp, MAY_READWRITE);
3392}
3393
3394/**
3395 * smack_ipc_permission - Smack access for ipc_permission()
3396 * @ipp: the object permissions
3397 * @flag: access requested
3398 *
3399 * Returns 0 if current has read and write access, error code otherwise
3400 */
3401static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
3402{
3403 struct smack_known **blob = smack_ipc(ipp);
3404 struct smack_known *iskp = *blob;
3405 int may = smack_flags_to_may(flag);
3406 struct smk_audit_info ad;
3407 int rc;
3408
3409#ifdef CONFIG_AUDIT
3410 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3411 ad.a.u.ipc_id = ipp->id;
3412#endif
3413 rc = smk_curacc(iskp, may, &ad);
3414 rc = smk_bu_current("svipc", iskp, may, rc);
3415 return rc;
3416}
3417
3418/**
3419 * smack_ipc_getsecid - Extract smack security id
3420 * @ipp: the object permissions
3421 * @secid: where result will be saved
3422 */
3423static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
3424{
3425 struct smack_known **blob = smack_ipc(ipp);
3426 struct smack_known *iskp = *blob;
3427
3428 *secid = iskp->smk_secid;
3429}
3430
3431/**
3432 * smack_d_instantiate - Make sure the blob is correct on an inode
3433 * @opt_dentry: dentry where inode will be attached
3434 * @inode: the object
3435 *
3436 * Set the inode's security blob if it hasn't been done already.
3437 */
3438static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
3439{
3440 struct super_block *sbp;
3441 struct superblock_smack *sbsp;
3442 struct inode_smack *isp;
3443 struct smack_known *skp;
3444 struct smack_known *ckp = smk_of_current();
3445 struct smack_known *final;
3446 char trattr[TRANS_TRUE_SIZE];
3447 int transflag = 0;
3448 int rc;
3449 struct dentry *dp;
3450
3451 if (inode == NULL)
3452 return;
3453
3454 isp = smack_inode(inode);
3455
3456 /*
3457 * If the inode is already instantiated
3458 * take the quick way out
3459 */
3460 if (isp->smk_flags & SMK_INODE_INSTANT)
3461 return;
3462
3463 sbp = inode->i_sb;
3464 sbsp = smack_superblock(sbp);
3465 /*
3466 * We're going to use the superblock default label
3467 * if there's no label on the file.
3468 */
3469 final = sbsp->smk_default;
3470
3471 /*
3472 * If this is the root inode the superblock
3473 * may be in the process of initialization.
3474 * If that is the case use the root value out
3475 * of the superblock.
3476 */
3477 if (opt_dentry->d_parent == opt_dentry) {
3478 switch (sbp->s_magic) {
3479 case CGROUP_SUPER_MAGIC:
3480 case CGROUP2_SUPER_MAGIC:
3481 /*
3482 * The cgroup filesystem is never mounted,
3483 * so there's no opportunity to set the mount
3484 * options.
3485 */
3486 sbsp->smk_root = &smack_known_star;
3487 sbsp->smk_default = &smack_known_star;
3488 isp->smk_inode = sbsp->smk_root;
3489 break;
3490 case TMPFS_MAGIC:
3491 /*
3492 * What about shmem/tmpfs anonymous files with dentry
3493 * obtained from d_alloc_pseudo()?
3494 */
3495 isp->smk_inode = smk_of_current();
3496 break;
3497 case PIPEFS_MAGIC:
3498 isp->smk_inode = smk_of_current();
3499 break;
3500 case SOCKFS_MAGIC:
3501 /*
3502 * Socket access is controlled by the socket
3503 * structures associated with the task involved.
3504 */
3505 isp->smk_inode = &smack_known_star;
3506 break;
3507 default:
3508 isp->smk_inode = sbsp->smk_root;
3509 break;
3510 }
3511 isp->smk_flags |= SMK_INODE_INSTANT;
3512 return;
3513 }
3514
3515 /*
3516 * This is pretty hackish.
3517 * Casey says that we shouldn't have to do
3518 * file system specific code, but it does help
3519 * with keeping it simple.
3520 */
3521 switch (sbp->s_magic) {
3522 case SMACK_MAGIC:
3523 case CGROUP_SUPER_MAGIC:
3524 case CGROUP2_SUPER_MAGIC:
3525 /*
3526 * Casey says that it's a little embarrassing
3527 * that the smack file system doesn't do
3528 * extended attributes.
3529 *
3530 * Cgroupfs is special
3531 */
3532 final = &smack_known_star;
3533 break;
3534 case DEVPTS_SUPER_MAGIC:
3535 /*
3536 * devpts seems content with the label of the task.
3537 * Programs that change smack have to treat the
3538 * pty with respect.
3539 */
3540 final = ckp;
3541 break;
3542 case PROC_SUPER_MAGIC:
3543 /*
3544 * Casey says procfs appears not to care.
3545 * The superblock default suffices.
3546 */
3547 break;
3548 case TMPFS_MAGIC:
3549 /*
3550 * Device labels should come from the filesystem,
3551 * but watch out, because they're volitile,
3552 * getting recreated on every reboot.
3553 */
3554 final = &smack_known_star;
3555 /*
3556 * If a smack value has been set we want to use it,
3557 * but since tmpfs isn't giving us the opportunity
3558 * to set mount options simulate setting the
3559 * superblock default.
3560 */
3561 fallthrough;
3562 default:
3563 /*
3564 * This isn't an understood special case.
3565 * Get the value from the xattr.
3566 */
3567
3568 /*
3569 * UNIX domain sockets use lower level socket data.
3570 */
3571 if (S_ISSOCK(inode->i_mode)) {
3572 final = &smack_known_star;
3573 break;
3574 }
3575 /*
3576 * No xattr support means, alas, no SMACK label.
3577 * Use the aforeapplied default.
3578 * It would be curious if the label of the task
3579 * does not match that assigned.
3580 */
3581 if (!(inode->i_opflags & IOP_XATTR))
3582 break;
3583 /*
3584 * Get the dentry for xattr.
3585 */
3586 dp = dget(opt_dentry);
3587 skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
3588 if (!IS_ERR_OR_NULL(skp))
3589 final = skp;
3590
3591 /*
3592 * Transmuting directory
3593 */
3594 if (S_ISDIR(inode->i_mode)) {
3595 /*
3596 * If this is a new directory and the label was
3597 * transmuted when the inode was initialized
3598 * set the transmute attribute on the directory
3599 * and mark the inode.
3600 *
3601 * If there is a transmute attribute on the
3602 * directory mark the inode.
3603 */
3604 rc = __vfs_getxattr(dp, inode,
3605 XATTR_NAME_SMACKTRANSMUTE, trattr,
3606 TRANS_TRUE_SIZE);
3607 if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
3608 TRANS_TRUE_SIZE) != 0)
3609 rc = -EINVAL;
3610 if (rc >= 0)
3611 transflag = SMK_INODE_TRANSMUTE;
3612 }
3613 /*
3614 * Don't let the exec or mmap label be "*" or "@".
3615 */
3616 skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
3617 if (IS_ERR(skp) || skp == &smack_known_star ||
3618 skp == &smack_known_web)
3619 skp = NULL;
3620 isp->smk_task = skp;
3621
3622 skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
3623 if (IS_ERR(skp) || skp == &smack_known_star ||
3624 skp == &smack_known_web)
3625 skp = NULL;
3626 isp->smk_mmap = skp;
3627
3628 dput(dp);
3629 break;
3630 }
3631
3632 if (final == NULL)
3633 isp->smk_inode = ckp;
3634 else
3635 isp->smk_inode = final;
3636
3637 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3638
3639 return;
3640}
3641
3642/**
3643 * smack_getselfattr - Smack current process attribute
3644 * @attr: which attribute to fetch
3645 * @ctx: buffer to receive the result
3646 * @size: available size in, actual size out
3647 * @flags: unused
3648 *
3649 * Fill the passed user space @ctx with the details of the requested
3650 * attribute.
3651 *
3652 * Returns the number of attributes on success, an error code otherwise.
3653 * There will only ever be one attribute.
3654 */
3655static int smack_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
3656 u32 *size, u32 flags)
3657{
3658 int rc;
3659 struct smack_known *skp;
3660
3661 if (attr != LSM_ATTR_CURRENT)
3662 return -EOPNOTSUPP;
3663
3664 skp = smk_of_current();
3665 rc = lsm_fill_user_ctx(ctx, size,
3666 skp->smk_known, strlen(skp->smk_known) + 1,
3667 LSM_ID_SMACK, 0);
3668 return (!rc ? 1 : rc);
3669}
3670
3671/**
3672 * smack_getprocattr - Smack process attribute access
3673 * @p: the object task
3674 * @name: the name of the attribute in /proc/.../attr
3675 * @value: where to put the result
3676 *
3677 * Places a copy of the task Smack into value
3678 *
3679 * Returns the length of the smack label or an error code
3680 */
3681static int smack_getprocattr(struct task_struct *p, const char *name, char **value)
3682{
3683 struct smack_known *skp = smk_of_task_struct_obj(p);
3684 char *cp;
3685 int slen;
3686
3687 if (strcmp(name, "current") != 0)
3688 return -EINVAL;
3689
3690 cp = kstrdup(skp->smk_known, GFP_KERNEL);
3691 if (cp == NULL)
3692 return -ENOMEM;
3693
3694 slen = strlen(cp);
3695 *value = cp;
3696 return slen;
3697}
3698
3699/**
3700 * do_setattr - Smack process attribute setting
3701 * @attr: the ID of the attribute
3702 * @value: the value to set
3703 * @size: the size of the value
3704 *
3705 * Sets the Smack value of the task. Only setting self
3706 * is permitted and only with privilege
3707 *
3708 * Returns the length of the smack label or an error code
3709 */
3710static int do_setattr(u64 attr, void *value, size_t size)
3711{
3712 struct task_smack *tsp = smack_cred(current_cred());
3713 struct cred *new;
3714 struct smack_known *skp;
3715 struct smack_known_list_elem *sklep;
3716 int rc;
3717
3718 if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
3719 return -EPERM;
3720
3721 if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3722 return -EINVAL;
3723
3724 if (attr != LSM_ATTR_CURRENT)
3725 return -EOPNOTSUPP;
3726
3727 skp = smk_import_entry(value, size);
3728 if (IS_ERR(skp))
3729 return PTR_ERR(skp);
3730
3731 /*
3732 * No process is ever allowed the web ("@") label
3733 * and the star ("*") label.
3734 */
3735 if (skp == &smack_known_web || skp == &smack_known_star)
3736 return -EINVAL;
3737
3738 if (!smack_privileged(CAP_MAC_ADMIN)) {
3739 rc = -EPERM;
3740 list_for_each_entry(sklep, &tsp->smk_relabel, list)
3741 if (sklep->smk_label == skp) {
3742 rc = 0;
3743 break;
3744 }
3745 if (rc)
3746 return rc;
3747 }
3748
3749 new = prepare_creds();
3750 if (new == NULL)
3751 return -ENOMEM;
3752
3753 tsp = smack_cred(new);
3754 tsp->smk_task = skp;
3755 /*
3756 * process can change its label only once
3757 */
3758 smk_destroy_label_list(&tsp->smk_relabel);
3759
3760 commit_creds(new);
3761 return size;
3762}
3763
3764/**
3765 * smack_setselfattr - Set a Smack process attribute
3766 * @attr: which attribute to set
3767 * @ctx: buffer containing the data
3768 * @size: size of @ctx
3769 * @flags: unused
3770 *
3771 * Fill the passed user space @ctx with the details of the requested
3772 * attribute.
3773 *
3774 * Returns 0 on success, an error code otherwise.
3775 */
3776static int smack_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
3777 u32 size, u32 flags)
3778{
3779 int rc;
3780
3781 rc = do_setattr(attr, ctx->ctx, ctx->ctx_len);
3782 if (rc > 0)
3783 return 0;
3784 return rc;
3785}
3786
3787/**
3788 * smack_setprocattr - Smack process attribute setting
3789 * @name: the name of the attribute in /proc/.../attr
3790 * @value: the value to set
3791 * @size: the size of the value
3792 *
3793 * Sets the Smack value of the task. Only setting self
3794 * is permitted and only with privilege
3795 *
3796 * Returns the length of the smack label or an error code
3797 */
3798static int smack_setprocattr(const char *name, void *value, size_t size)
3799{
3800 int attr = lsm_name_to_attr(name);
3801
3802 if (attr != LSM_ATTR_UNDEF)
3803 return do_setattr(attr, value, size);
3804 return -EINVAL;
3805}
3806
3807/**
3808 * smack_unix_stream_connect - Smack access on UDS
3809 * @sock: one sock
3810 * @other: the other sock
3811 * @newsk: unused
3812 *
3813 * Return 0 if a subject with the smack of sock could access
3814 * an object with the smack of other, otherwise an error code
3815 */
3816static int smack_unix_stream_connect(struct sock *sock,
3817 struct sock *other, struct sock *newsk)
3818{
3819 struct smack_known *skp;
3820 struct smack_known *okp;
3821 struct socket_smack *ssp = sock->sk_security;
3822 struct socket_smack *osp = other->sk_security;
3823 struct socket_smack *nsp = newsk->sk_security;
3824 struct smk_audit_info ad;
3825 int rc = 0;
3826#ifdef CONFIG_AUDIT
3827 struct lsm_network_audit net;
3828#endif
3829
3830 if (!smack_privileged(CAP_MAC_OVERRIDE)) {
3831 skp = ssp->smk_out;
3832 okp = osp->smk_in;
3833#ifdef CONFIG_AUDIT
3834 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3835 smk_ad_setfield_u_net_sk(&ad, other);
3836#endif
3837 rc = smk_access(skp, okp, MAY_WRITE, &ad);
3838 rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
3839 if (rc == 0) {
3840 okp = osp->smk_out;
3841 skp = ssp->smk_in;
3842 rc = smk_access(okp, skp, MAY_WRITE, &ad);
3843 rc = smk_bu_note("UDS connect", okp, skp,
3844 MAY_WRITE, rc);
3845 }
3846 }
3847
3848 /*
3849 * Cross reference the peer labels for SO_PEERSEC.
3850 */
3851 if (rc == 0) {
3852 nsp->smk_packet = ssp->smk_out;
3853 ssp->smk_packet = osp->smk_out;
3854 }
3855
3856 return rc;
3857}
3858
3859/**
3860 * smack_unix_may_send - Smack access on UDS
3861 * @sock: one socket
3862 * @other: the other socket
3863 *
3864 * Return 0 if a subject with the smack of sock could access
3865 * an object with the smack of other, otherwise an error code
3866 */
3867static int smack_unix_may_send(struct socket *sock, struct socket *other)
3868{
3869 struct socket_smack *ssp = sock->sk->sk_security;
3870 struct socket_smack *osp = other->sk->sk_security;
3871 struct smk_audit_info ad;
3872 int rc;
3873
3874#ifdef CONFIG_AUDIT
3875 struct lsm_network_audit net;
3876
3877 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3878 smk_ad_setfield_u_net_sk(&ad, other->sk);
3879#endif
3880
3881 if (smack_privileged(CAP_MAC_OVERRIDE))
3882 return 0;
3883
3884 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
3885 rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
3886 return rc;
3887}
3888
3889/**
3890 * smack_socket_sendmsg - Smack check based on destination host
3891 * @sock: the socket
3892 * @msg: the message
3893 * @size: the size of the message
3894 *
3895 * Return 0 if the current subject can write to the destination host.
3896 * For IPv4 this is only a question if the destination is a single label host.
3897 * For IPv6 this is a check against the label of the port.
3898 */
3899static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3900 int size)
3901{
3902 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3903#if IS_ENABLED(CONFIG_IPV6)
3904 struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3905#endif
3906#ifdef SMACK_IPV6_SECMARK_LABELING
3907 struct socket_smack *ssp = sock->sk->sk_security;
3908 struct smack_known *rsp;
3909#endif
3910 int rc = 0;
3911
3912 /*
3913 * Perfectly reasonable for this to be NULL
3914 */
3915 if (sip == NULL)
3916 return 0;
3917
3918 switch (sock->sk->sk_family) {
3919 case AF_INET:
3920 if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
3921 sip->sin_family != AF_INET)
3922 return -EINVAL;
3923 rc = smk_ipv4_check(sock->sk, sip);
3924 break;
3925#if IS_ENABLED(CONFIG_IPV6)
3926 case AF_INET6:
3927 if (msg->msg_namelen < SIN6_LEN_RFC2133 ||
3928 sap->sin6_family != AF_INET6)
3929 return -EINVAL;
3930#ifdef SMACK_IPV6_SECMARK_LABELING
3931 rsp = smack_ipv6host_label(sap);
3932 if (rsp != NULL)
3933 rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
3934 SMK_CONNECTING);
3935#endif
3936#ifdef SMACK_IPV6_PORT_LABELING
3937 rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3938#endif
3939#endif /* IS_ENABLED(CONFIG_IPV6) */
3940 break;
3941 }
3942 return rc;
3943}
3944
3945/**
3946 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3947 * @sap: netlabel secattr
3948 * @ssp: socket security information
3949 *
3950 * Returns a pointer to a Smack label entry found on the label list.
3951 */
3952static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
3953 struct socket_smack *ssp)
3954{
3955 struct smack_known *skp;
3956 int found = 0;
3957 int acat;
3958 int kcat;
3959
3960 /*
3961 * Netlabel found it in the cache.
3962 */
3963 if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
3964 return (struct smack_known *)sap->cache->data;
3965
3966 if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
3967 /*
3968 * Looks like a fallback, which gives us a secid.
3969 */
3970 return smack_from_secid(sap->attr.secid);
3971
3972 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3973 /*
3974 * Looks like a CIPSO packet.
3975 * If there are flags but no level netlabel isn't
3976 * behaving the way we expect it to.
3977 *
3978 * Look it up in the label table
3979 * Without guidance regarding the smack value
3980 * for the packet fall back on the network
3981 * ambient value.
3982 */
3983 rcu_read_lock();
3984 list_for_each_entry_rcu(skp, &smack_known_list, list) {
3985 if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3986 continue;
3987 /*
3988 * Compare the catsets. Use the netlbl APIs.
3989 */
3990 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
3991 if ((skp->smk_netlabel.flags &
3992 NETLBL_SECATTR_MLS_CAT) == 0)
3993 found = 1;
3994 break;
3995 }
3996 for (acat = -1, kcat = -1; acat == kcat; ) {
3997 acat = netlbl_catmap_walk(sap->attr.mls.cat,
3998 acat + 1);
3999 kcat = netlbl_catmap_walk(
4000 skp->smk_netlabel.attr.mls.cat,
4001 kcat + 1);
4002 if (acat < 0 || kcat < 0)
4003 break;
4004 }
4005 if (acat == kcat) {
4006 found = 1;
4007 break;
4008 }
4009 }
4010 rcu_read_unlock();
4011
4012 if (found)
4013 return skp;
4014
4015 if (ssp != NULL && ssp->smk_in == &smack_known_star)
4016 return &smack_known_web;
4017 return &smack_known_star;
4018 }
4019 /*
4020 * Without guidance regarding the smack value
4021 * for the packet fall back on the network
4022 * ambient value.
4023 */
4024 return smack_net_ambient;
4025}
4026
4027#if IS_ENABLED(CONFIG_IPV6)
4028static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
4029{
4030 u8 nexthdr;
4031 int offset;
4032 int proto = -EINVAL;
4033 struct ipv6hdr _ipv6h;
4034 struct ipv6hdr *ip6;
4035 __be16 frag_off;
4036 struct tcphdr _tcph, *th;
4037 struct udphdr _udph, *uh;
4038 struct dccp_hdr _dccph, *dh;
4039
4040 sip->sin6_port = 0;
4041
4042 offset = skb_network_offset(skb);
4043 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4044 if (ip6 == NULL)
4045 return -EINVAL;
4046 sip->sin6_addr = ip6->saddr;
4047
4048 nexthdr = ip6->nexthdr;
4049 offset += sizeof(_ipv6h);
4050 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4051 if (offset < 0)
4052 return -EINVAL;
4053
4054 proto = nexthdr;
4055 switch (proto) {
4056 case IPPROTO_TCP:
4057 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4058 if (th != NULL)
4059 sip->sin6_port = th->source;
4060 break;
4061 case IPPROTO_UDP:
4062 case IPPROTO_UDPLITE:
4063 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4064 if (uh != NULL)
4065 sip->sin6_port = uh->source;
4066 break;
4067 case IPPROTO_DCCP:
4068 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4069 if (dh != NULL)
4070 sip->sin6_port = dh->dccph_sport;
4071 break;
4072 }
4073 return proto;
4074}
4075#endif /* CONFIG_IPV6 */
4076
4077/**
4078 * smack_from_skb - Smack data from the secmark in an skb
4079 * @skb: packet
4080 *
4081 * Returns smack_known of the secmark or NULL if that won't work.
4082 */
4083#ifdef CONFIG_NETWORK_SECMARK
4084static struct smack_known *smack_from_skb(struct sk_buff *skb)
4085{
4086 if (skb == NULL || skb->secmark == 0)
4087 return NULL;
4088
4089 return smack_from_secid(skb->secmark);
4090}
4091#else
4092static inline struct smack_known *smack_from_skb(struct sk_buff *skb)
4093{
4094 return NULL;
4095}
4096#endif
4097
4098/**
4099 * smack_from_netlbl - Smack data from the IP options in an skb
4100 * @sk: socket data came in on
4101 * @family: address family
4102 * @skb: packet
4103 *
4104 * Find the Smack label in the IP options. If it hasn't been
4105 * added to the netlabel cache, add it here.
4106 *
4107 * Returns smack_known of the IP options or NULL if that won't work.
4108 */
4109static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
4110 struct sk_buff *skb)
4111{
4112 struct netlbl_lsm_secattr secattr;
4113 struct socket_smack *ssp = NULL;
4114 struct smack_known *skp = NULL;
4115
4116 netlbl_secattr_init(&secattr);
4117
4118 if (sk)
4119 ssp = sk->sk_security;
4120
4121 if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
4122 skp = smack_from_secattr(&secattr, ssp);
4123 if (secattr.flags & NETLBL_SECATTR_CACHEABLE)
4124 netlbl_cache_add(skb, family, &skp->smk_netlabel);
4125 }
4126
4127 netlbl_secattr_destroy(&secattr);
4128
4129 return skp;
4130}
4131
4132/**
4133 * smack_socket_sock_rcv_skb - Smack packet delivery access check
4134 * @sk: socket
4135 * @skb: packet
4136 *
4137 * Returns 0 if the packet should be delivered, an error code otherwise
4138 */
4139static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4140{
4141 struct socket_smack *ssp = sk->sk_security;
4142 struct smack_known *skp = NULL;
4143 int rc = 0;
4144 struct smk_audit_info ad;
4145 u16 family = sk->sk_family;
4146#ifdef CONFIG_AUDIT
4147 struct lsm_network_audit net;
4148#endif
4149#if IS_ENABLED(CONFIG_IPV6)
4150 struct sockaddr_in6 sadd;
4151 int proto;
4152
4153 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4154 family = PF_INET;
4155#endif /* CONFIG_IPV6 */
4156
4157 switch (family) {
4158 case PF_INET:
4159 /*
4160 * If there is a secmark use it rather than the CIPSO label.
4161 * If there is no secmark fall back to CIPSO.
4162 * The secmark is assumed to reflect policy better.
4163 */
4164 skp = smack_from_skb(skb);
4165 if (skp == NULL) {
4166 skp = smack_from_netlbl(sk, family, skb);
4167 if (skp == NULL)
4168 skp = smack_net_ambient;
4169 }
4170
4171#ifdef CONFIG_AUDIT
4172 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4173 ad.a.u.net->family = family;
4174 ad.a.u.net->netif = skb->skb_iif;
4175 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4176#endif
4177 /*
4178 * Receiving a packet requires that the other end
4179 * be able to write here. Read access is not required.
4180 * This is the simplist possible security model
4181 * for networking.
4182 */
4183 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4184 rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
4185 MAY_WRITE, rc);
4186 if (rc != 0)
4187 netlbl_skbuff_err(skb, family, rc, 0);
4188 break;
4189#if IS_ENABLED(CONFIG_IPV6)
4190 case PF_INET6:
4191 proto = smk_skb_to_addr_ipv6(skb, &sadd);
4192 if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE &&
4193 proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
4194 break;
4195#ifdef SMACK_IPV6_SECMARK_LABELING
4196 skp = smack_from_skb(skb);
4197 if (skp == NULL) {
4198 if (smk_ipv6_localhost(&sadd))
4199 break;
4200 skp = smack_ipv6host_label(&sadd);
4201 if (skp == NULL)
4202 skp = smack_net_ambient;
4203 }
4204#ifdef CONFIG_AUDIT
4205 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4206 ad.a.u.net->family = family;
4207 ad.a.u.net->netif = skb->skb_iif;
4208 ipv6_skb_to_auditdata(skb, &ad.a, NULL);
4209#endif /* CONFIG_AUDIT */
4210 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4211 rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
4212 MAY_WRITE, rc);
4213#endif /* SMACK_IPV6_SECMARK_LABELING */
4214#ifdef SMACK_IPV6_PORT_LABELING
4215 rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
4216#endif /* SMACK_IPV6_PORT_LABELING */
4217 if (rc != 0)
4218 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
4219 ICMPV6_ADM_PROHIBITED, 0);
4220 break;
4221#endif /* CONFIG_IPV6 */
4222 }
4223
4224 return rc;
4225}
4226
4227/**
4228 * smack_socket_getpeersec_stream - pull in packet label
4229 * @sock: the socket
4230 * @optval: user's destination
4231 * @optlen: size thereof
4232 * @len: max thereof
4233 *
4234 * returns zero on success, an error code otherwise
4235 */
4236static int smack_socket_getpeersec_stream(struct socket *sock,
4237 sockptr_t optval, sockptr_t optlen,
4238 unsigned int len)
4239{
4240 struct socket_smack *ssp;
4241 char *rcp = "";
4242 u32 slen = 1;
4243 int rc = 0;
4244
4245 ssp = sock->sk->sk_security;
4246 if (ssp->smk_packet != NULL) {
4247 rcp = ssp->smk_packet->smk_known;
4248 slen = strlen(rcp) + 1;
4249 }
4250 if (slen > len) {
4251 rc = -ERANGE;
4252 goto out_len;
4253 }
4254
4255 if (copy_to_sockptr(optval, rcp, slen))
4256 rc = -EFAULT;
4257out_len:
4258 if (copy_to_sockptr(optlen, &slen, sizeof(slen)))
4259 rc = -EFAULT;
4260 return rc;
4261}
4262
4263
4264/**
4265 * smack_socket_getpeersec_dgram - pull in packet label
4266 * @sock: the peer socket
4267 * @skb: packet data
4268 * @secid: pointer to where to put the secid of the packet
4269 *
4270 * Sets the netlabel socket state on sk from parent
4271 */
4272static int smack_socket_getpeersec_dgram(struct socket *sock,
4273 struct sk_buff *skb, u32 *secid)
4274
4275{
4276 struct socket_smack *ssp = NULL;
4277 struct smack_known *skp;
4278 struct sock *sk = NULL;
4279 int family = PF_UNSPEC;
4280 u32 s = 0; /* 0 is the invalid secid */
4281
4282 if (skb != NULL) {
4283 if (skb->protocol == htons(ETH_P_IP))
4284 family = PF_INET;
4285#if IS_ENABLED(CONFIG_IPV6)
4286 else if (skb->protocol == htons(ETH_P_IPV6))
4287 family = PF_INET6;
4288#endif /* CONFIG_IPV6 */
4289 }
4290 if (family == PF_UNSPEC && sock != NULL)
4291 family = sock->sk->sk_family;
4292
4293 switch (family) {
4294 case PF_UNIX:
4295 ssp = sock->sk->sk_security;
4296 s = ssp->smk_out->smk_secid;
4297 break;
4298 case PF_INET:
4299 skp = smack_from_skb(skb);
4300 if (skp) {
4301 s = skp->smk_secid;
4302 break;
4303 }
4304 /*
4305 * Translate what netlabel gave us.
4306 */
4307 if (sock != NULL)
4308 sk = sock->sk;
4309 skp = smack_from_netlbl(sk, family, skb);
4310 if (skp != NULL)
4311 s = skp->smk_secid;
4312 break;
4313 case PF_INET6:
4314#ifdef SMACK_IPV6_SECMARK_LABELING
4315 skp = smack_from_skb(skb);
4316 if (skp)
4317 s = skp->smk_secid;
4318#endif
4319 break;
4320 }
4321 *secid = s;
4322 if (s == 0)
4323 return -EINVAL;
4324 return 0;
4325}
4326
4327/**
4328 * smack_sock_graft - Initialize a newly created socket with an existing sock
4329 * @sk: child sock
4330 * @parent: parent socket
4331 *
4332 * Set the smk_{in,out} state of an existing sock based on the process that
4333 * is creating the new socket.
4334 */
4335static void smack_sock_graft(struct sock *sk, struct socket *parent)
4336{
4337 struct socket_smack *ssp;
4338 struct smack_known *skp = smk_of_current();
4339
4340 if (sk == NULL ||
4341 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
4342 return;
4343
4344 ssp = sk->sk_security;
4345 ssp->smk_in = skp;
4346 ssp->smk_out = skp;
4347 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
4348}
4349
4350/**
4351 * smack_inet_conn_request - Smack access check on connect
4352 * @sk: socket involved
4353 * @skb: packet
4354 * @req: unused
4355 *
4356 * Returns 0 if a task with the packet label could write to
4357 * the socket, otherwise an error code
4358 */
4359static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
4360 struct request_sock *req)
4361{
4362 u16 family = sk->sk_family;
4363 struct smack_known *skp;
4364 struct socket_smack *ssp = sk->sk_security;
4365 struct sockaddr_in addr;
4366 struct iphdr *hdr;
4367 struct smack_known *hskp;
4368 int rc;
4369 struct smk_audit_info ad;
4370#ifdef CONFIG_AUDIT
4371 struct lsm_network_audit net;
4372#endif
4373
4374#if IS_ENABLED(CONFIG_IPV6)
4375 if (family == PF_INET6) {
4376 /*
4377 * Handle mapped IPv4 packets arriving
4378 * via IPv6 sockets. Don't set up netlabel
4379 * processing on IPv6.
4380 */
4381 if (skb->protocol == htons(ETH_P_IP))
4382 family = PF_INET;
4383 else
4384 return 0;
4385 }
4386#endif /* CONFIG_IPV6 */
4387
4388 /*
4389 * If there is a secmark use it rather than the CIPSO label.
4390 * If there is no secmark fall back to CIPSO.
4391 * The secmark is assumed to reflect policy better.
4392 */
4393 skp = smack_from_skb(skb);
4394 if (skp == NULL) {
4395 skp = smack_from_netlbl(sk, family, skb);
4396 if (skp == NULL)
4397 skp = &smack_known_huh;
4398 }
4399
4400#ifdef CONFIG_AUDIT
4401 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4402 ad.a.u.net->family = family;
4403 ad.a.u.net->netif = skb->skb_iif;
4404 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4405#endif
4406 /*
4407 * Receiving a packet requires that the other end be able to write
4408 * here. Read access is not required.
4409 */
4410 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4411 rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
4412 if (rc != 0)
4413 return rc;
4414
4415 /*
4416 * Save the peer's label in the request_sock so we can later setup
4417 * smk_packet in the child socket so that SO_PEERCRED can report it.
4418 */
4419 req->peer_secid = skp->smk_secid;
4420
4421 /*
4422 * We need to decide if we want to label the incoming connection here
4423 * if we do we only need to label the request_sock and the stack will
4424 * propagate the wire-label to the sock when it is created.
4425 */
4426 hdr = ip_hdr(skb);
4427 addr.sin_addr.s_addr = hdr->saddr;
4428 rcu_read_lock();
4429 hskp = smack_ipv4host_label(&addr);
4430 rcu_read_unlock();
4431
4432 if (hskp == NULL)
4433 rc = netlbl_req_setattr(req, &skp->smk_netlabel);
4434 else
4435 netlbl_req_delattr(req);
4436
4437 return rc;
4438}
4439
4440/**
4441 * smack_inet_csk_clone - Copy the connection information to the new socket
4442 * @sk: the new socket
4443 * @req: the connection's request_sock
4444 *
4445 * Transfer the connection's peer label to the newly created socket.
4446 */
4447static void smack_inet_csk_clone(struct sock *sk,
4448 const struct request_sock *req)
4449{
4450 struct socket_smack *ssp = sk->sk_security;
4451 struct smack_known *skp;
4452
4453 if (req->peer_secid != 0) {
4454 skp = smack_from_secid(req->peer_secid);
4455 ssp->smk_packet = skp;
4456 } else
4457 ssp->smk_packet = NULL;
4458}
4459
4460/*
4461 * Key management security hooks
4462 *
4463 * Casey has not tested key support very heavily.
4464 * The permission check is most likely too restrictive.
4465 * If you care about keys please have a look.
4466 */
4467#ifdef CONFIG_KEYS
4468
4469/**
4470 * smack_key_alloc - Set the key security blob
4471 * @key: object
4472 * @cred: the credentials to use
4473 * @flags: unused
4474 *
4475 * No allocation required
4476 *
4477 * Returns 0
4478 */
4479static int smack_key_alloc(struct key *key, const struct cred *cred,
4480 unsigned long flags)
4481{
4482 struct smack_known *skp = smk_of_task(smack_cred(cred));
4483
4484 key->security = skp;
4485 return 0;
4486}
4487
4488/**
4489 * smack_key_free - Clear the key security blob
4490 * @key: the object
4491 *
4492 * Clear the blob pointer
4493 */
4494static void smack_key_free(struct key *key)
4495{
4496 key->security = NULL;
4497}
4498
4499/**
4500 * smack_key_permission - Smack access on a key
4501 * @key_ref: gets to the object
4502 * @cred: the credentials to use
4503 * @need_perm: requested key permission
4504 *
4505 * Return 0 if the task has read and write to the object,
4506 * an error code otherwise
4507 */
4508static int smack_key_permission(key_ref_t key_ref,
4509 const struct cred *cred,
4510 enum key_need_perm need_perm)
4511{
4512 struct key *keyp;
4513 struct smk_audit_info ad;
4514 struct smack_known *tkp = smk_of_task(smack_cred(cred));
4515 int request = 0;
4516 int rc;
4517
4518 /*
4519 * Validate requested permissions
4520 */
4521 switch (need_perm) {
4522 case KEY_NEED_READ:
4523 case KEY_NEED_SEARCH:
4524 case KEY_NEED_VIEW:
4525 request |= MAY_READ;
4526 break;
4527 case KEY_NEED_WRITE:
4528 case KEY_NEED_LINK:
4529 case KEY_NEED_SETATTR:
4530 request |= MAY_WRITE;
4531 break;
4532 case KEY_NEED_UNSPECIFIED:
4533 case KEY_NEED_UNLINK:
4534 case KEY_SYSADMIN_OVERRIDE:
4535 case KEY_AUTHTOKEN_OVERRIDE:
4536 case KEY_DEFER_PERM_CHECK:
4537 return 0;
4538 default:
4539 return -EINVAL;
4540 }
4541
4542 keyp = key_ref_to_ptr(key_ref);
4543 if (keyp == NULL)
4544 return -EINVAL;
4545 /*
4546 * If the key hasn't been initialized give it access so that
4547 * it may do so.
4548 */
4549 if (keyp->security == NULL)
4550 return 0;
4551 /*
4552 * This should not occur
4553 */
4554 if (tkp == NULL)
4555 return -EACCES;
4556
4557 if (smack_privileged(CAP_MAC_OVERRIDE))
4558 return 0;
4559
4560#ifdef CONFIG_AUDIT
4561 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4562 ad.a.u.key_struct.key = keyp->serial;
4563 ad.a.u.key_struct.key_desc = keyp->description;
4564#endif
4565 rc = smk_access(tkp, keyp->security, request, &ad);
4566 rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
4567 return rc;
4568}
4569
4570/*
4571 * smack_key_getsecurity - Smack label tagging the key
4572 * @key points to the key to be queried
4573 * @_buffer points to a pointer that should be set to point to the
4574 * resulting string (if no label or an error occurs).
4575 * Return the length of the string (including terminating NUL) or -ve if
4576 * an error.
4577 * May also return 0 (and a NULL buffer pointer) if there is no label.
4578 */
4579static int smack_key_getsecurity(struct key *key, char **_buffer)
4580{
4581 struct smack_known *skp = key->security;
4582 size_t length;
4583 char *copy;
4584
4585 if (key->security == NULL) {
4586 *_buffer = NULL;
4587 return 0;
4588 }
4589
4590 copy = kstrdup(skp->smk_known, GFP_KERNEL);
4591 if (copy == NULL)
4592 return -ENOMEM;
4593 length = strlen(copy) + 1;
4594
4595 *_buffer = copy;
4596 return length;
4597}
4598
4599
4600#ifdef CONFIG_KEY_NOTIFICATIONS
4601/**
4602 * smack_watch_key - Smack access to watch a key for notifications.
4603 * @key: The key to be watched
4604 *
4605 * Return 0 if the @watch->cred has permission to read from the key object and
4606 * an error otherwise.
4607 */
4608static int smack_watch_key(struct key *key)
4609{
4610 struct smk_audit_info ad;
4611 struct smack_known *tkp = smk_of_current();
4612 int rc;
4613
4614 if (key == NULL)
4615 return -EINVAL;
4616 /*
4617 * If the key hasn't been initialized give it access so that
4618 * it may do so.
4619 */
4620 if (key->security == NULL)
4621 return 0;
4622 /*
4623 * This should not occur
4624 */
4625 if (tkp == NULL)
4626 return -EACCES;
4627
4628 if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4629 return 0;
4630
4631#ifdef CONFIG_AUDIT
4632 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4633 ad.a.u.key_struct.key = key->serial;
4634 ad.a.u.key_struct.key_desc = key->description;
4635#endif
4636 rc = smk_access(tkp, key->security, MAY_READ, &ad);
4637 rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc);
4638 return rc;
4639}
4640#endif /* CONFIG_KEY_NOTIFICATIONS */
4641#endif /* CONFIG_KEYS */
4642
4643#ifdef CONFIG_WATCH_QUEUE
4644/**
4645 * smack_post_notification - Smack access to post a notification to a queue
4646 * @w_cred: The credentials of the watcher.
4647 * @cred: The credentials of the event source (may be NULL).
4648 * @n: The notification message to be posted.
4649 */
4650static int smack_post_notification(const struct cred *w_cred,
4651 const struct cred *cred,
4652 struct watch_notification *n)
4653{
4654 struct smk_audit_info ad;
4655 struct smack_known *subj, *obj;
4656 int rc;
4657
4658 /* Always let maintenance notifications through. */
4659 if (n->type == WATCH_TYPE_META)
4660 return 0;
4661
4662 if (!cred)
4663 return 0;
4664 subj = smk_of_task(smack_cred(cred));
4665 obj = smk_of_task(smack_cred(w_cred));
4666
4667 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION);
4668 rc = smk_access(subj, obj, MAY_WRITE, &ad);
4669 rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc);
4670 return rc;
4671}
4672#endif /* CONFIG_WATCH_QUEUE */
4673
4674/*
4675 * Smack Audit hooks
4676 *
4677 * Audit requires a unique representation of each Smack specific
4678 * rule. This unique representation is used to distinguish the
4679 * object to be audited from remaining kernel objects and also
4680 * works as a glue between the audit hooks.
4681 *
4682 * Since repository entries are added but never deleted, we'll use
4683 * the smack_known label address related to the given audit rule as
4684 * the needed unique representation. This also better fits the smack
4685 * model where nearly everything is a label.
4686 */
4687#ifdef CONFIG_AUDIT
4688
4689/**
4690 * smack_audit_rule_init - Initialize a smack audit rule
4691 * @field: audit rule fields given from user-space (audit.h)
4692 * @op: required testing operator (=, !=, >, <, ...)
4693 * @rulestr: smack label to be audited
4694 * @vrule: pointer to save our own audit rule representation
4695 *
4696 * Prepare to audit cases where (@field @op @rulestr) is true.
4697 * The label to be audited is created if necessay.
4698 */
4699static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
4700{
4701 struct smack_known *skp;
4702 char **rule = (char **)vrule;
4703 *rule = NULL;
4704
4705 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4706 return -EINVAL;
4707
4708 if (op != Audit_equal && op != Audit_not_equal)
4709 return -EINVAL;
4710
4711 skp = smk_import_entry(rulestr, 0);
4712 if (IS_ERR(skp))
4713 return PTR_ERR(skp);
4714
4715 *rule = skp->smk_known;
4716
4717 return 0;
4718}
4719
4720/**
4721 * smack_audit_rule_known - Distinguish Smack audit rules
4722 * @krule: rule of interest, in Audit kernel representation format
4723 *
4724 * This is used to filter Smack rules from remaining Audit ones.
4725 * If it's proved that this rule belongs to us, the
4726 * audit_rule_match hook will be called to do the final judgement.
4727 */
4728static int smack_audit_rule_known(struct audit_krule *krule)
4729{
4730 struct audit_field *f;
4731 int i;
4732
4733 for (i = 0; i < krule->field_count; i++) {
4734 f = &krule->fields[i];
4735
4736 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
4737 return 1;
4738 }
4739
4740 return 0;
4741}
4742
4743/**
4744 * smack_audit_rule_match - Audit given object ?
4745 * @secid: security id for identifying the object to test
4746 * @field: audit rule flags given from user-space
4747 * @op: required testing operator
4748 * @vrule: smack internal rule presentation
4749 *
4750 * The core Audit hook. It's used to take the decision of
4751 * whether to audit or not to audit a given object.
4752 */
4753static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
4754{
4755 struct smack_known *skp;
4756 char *rule = vrule;
4757
4758 if (unlikely(!rule)) {
4759 WARN_ONCE(1, "Smack: missing rule\n");
4760 return -ENOENT;
4761 }
4762
4763 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4764 return 0;
4765
4766 skp = smack_from_secid(secid);
4767
4768 /*
4769 * No need to do string comparisons. If a match occurs,
4770 * both pointers will point to the same smack_known
4771 * label.
4772 */
4773 if (op == Audit_equal)
4774 return (rule == skp->smk_known);
4775 if (op == Audit_not_equal)
4776 return (rule != skp->smk_known);
4777
4778 return 0;
4779}
4780
4781/*
4782 * There is no need for a smack_audit_rule_free hook.
4783 * No memory was allocated.
4784 */
4785
4786#endif /* CONFIG_AUDIT */
4787
4788/**
4789 * smack_ismaclabel - check if xattr @name references a smack MAC label
4790 * @name: Full xattr name to check.
4791 */
4792static int smack_ismaclabel(const char *name)
4793{
4794 return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
4795}
4796
4797
4798/**
4799 * smack_secid_to_secctx - return the smack label for a secid
4800 * @secid: incoming integer
4801 * @secdata: destination
4802 * @seclen: how long it is
4803 *
4804 * Exists for networking code.
4805 */
4806static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
4807{
4808 struct smack_known *skp = smack_from_secid(secid);
4809
4810 if (secdata)
4811 *secdata = skp->smk_known;
4812 *seclen = strlen(skp->smk_known);
4813 return 0;
4814}
4815
4816/**
4817 * smack_secctx_to_secid - return the secid for a smack label
4818 * @secdata: smack label
4819 * @seclen: how long result is
4820 * @secid: outgoing integer
4821 *
4822 * Exists for audit and networking code.
4823 */
4824static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4825{
4826 struct smack_known *skp = smk_find_entry(secdata);
4827
4828 if (skp)
4829 *secid = skp->smk_secid;
4830 else
4831 *secid = 0;
4832 return 0;
4833}
4834
4835/*
4836 * There used to be a smack_release_secctx hook
4837 * that did nothing back when hooks were in a vector.
4838 * Now that there's a list such a hook adds cost.
4839 */
4840
4841static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
4842{
4843 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx,
4844 ctxlen, 0);
4845}
4846
4847static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
4848{
4849 return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SMACK,
4850 ctx, ctxlen, 0);
4851}
4852
4853static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
4854{
4855 struct smack_known *skp = smk_of_inode(inode);
4856
4857 *ctx = skp->smk_known;
4858 *ctxlen = strlen(skp->smk_known);
4859 return 0;
4860}
4861
4862static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
4863{
4864
4865 struct task_smack *tsp;
4866 struct smack_known *skp;
4867 struct inode_smack *isp;
4868 struct cred *new_creds = *new;
4869
4870 if (new_creds == NULL) {
4871 new_creds = prepare_creds();
4872 if (new_creds == NULL)
4873 return -ENOMEM;
4874 }
4875
4876 tsp = smack_cred(new_creds);
4877
4878 /*
4879 * Get label from overlay inode and set it in create_sid
4880 */
4881 isp = smack_inode(d_inode(dentry));
4882 skp = isp->smk_inode;
4883 tsp->smk_task = skp;
4884 *new = new_creds;
4885 return 0;
4886}
4887
4888static int smack_inode_copy_up_xattr(const char *name)
4889{
4890 /*
4891 * Return 1 if this is the smack access Smack attribute.
4892 */
4893 if (strcmp(name, XATTR_NAME_SMACK) == 0)
4894 return 1;
4895
4896 return -EOPNOTSUPP;
4897}
4898
4899static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
4900 struct qstr *name,
4901 const struct cred *old,
4902 struct cred *new)
4903{
4904 struct task_smack *otsp = smack_cred(old);
4905 struct task_smack *ntsp = smack_cred(new);
4906 struct inode_smack *isp;
4907 int may;
4908
4909 /*
4910 * Use the process credential unless all of
4911 * the transmuting criteria are met
4912 */
4913 ntsp->smk_task = otsp->smk_task;
4914
4915 /*
4916 * the attribute of the containing directory
4917 */
4918 isp = smack_inode(d_inode(dentry->d_parent));
4919
4920 if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
4921 rcu_read_lock();
4922 may = smk_access_entry(otsp->smk_task->smk_known,
4923 isp->smk_inode->smk_known,
4924 &otsp->smk_task->smk_rules);
4925 rcu_read_unlock();
4926
4927 /*
4928 * If the directory is transmuting and the rule
4929 * providing access is transmuting use the containing
4930 * directory label instead of the process label.
4931 */
4932 if (may > 0 && (may & MAY_TRANSMUTE)) {
4933 ntsp->smk_task = isp->smk_inode;
4934 ntsp->smk_transmuted = ntsp->smk_task;
4935 }
4936 }
4937 return 0;
4938}
4939
4940#ifdef CONFIG_IO_URING
4941/**
4942 * smack_uring_override_creds - Is io_uring cred override allowed?
4943 * @new: the target creds
4944 *
4945 * Check to see if the current task is allowed to override it's credentials
4946 * to service an io_uring operation.
4947 */
4948static int smack_uring_override_creds(const struct cred *new)
4949{
4950 struct task_smack *tsp = smack_cred(current_cred());
4951 struct task_smack *nsp = smack_cred(new);
4952
4953 /*
4954 * Allow the degenerate case where the new Smack value is
4955 * the same as the current Smack value.
4956 */
4957 if (tsp->smk_task == nsp->smk_task)
4958 return 0;
4959
4960 if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4961 return 0;
4962
4963 return -EPERM;
4964}
4965
4966/**
4967 * smack_uring_sqpoll - check if a io_uring polling thread can be created
4968 *
4969 * Check to see if the current task is allowed to create a new io_uring
4970 * kernel polling thread.
4971 */
4972static int smack_uring_sqpoll(void)
4973{
4974 if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred()))
4975 return 0;
4976
4977 return -EPERM;
4978}
4979
4980/**
4981 * smack_uring_cmd - check on file operations for io_uring
4982 * @ioucmd: the command in question
4983 *
4984 * Make a best guess about whether a io_uring "command" should
4985 * be allowed. Use the same logic used for determining if the
4986 * file could be opened for read in the absence of better criteria.
4987 */
4988static int smack_uring_cmd(struct io_uring_cmd *ioucmd)
4989{
4990 struct file *file = ioucmd->file;
4991 struct smk_audit_info ad;
4992 struct task_smack *tsp;
4993 struct inode *inode;
4994 int rc;
4995
4996 if (!file)
4997 return -EINVAL;
4998
4999 tsp = smack_cred(file->f_cred);
5000 inode = file_inode(file);
5001
5002 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
5003 smk_ad_setfield_u_fs_path(&ad, file->f_path);
5004 rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
5005 rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
5006
5007 return rc;
5008}
5009
5010#endif /* CONFIG_IO_URING */
5011
5012struct lsm_blob_sizes smack_blob_sizes __ro_after_init = {
5013 .lbs_cred = sizeof(struct task_smack),
5014 .lbs_file = sizeof(struct smack_known *),
5015 .lbs_inode = sizeof(struct inode_smack),
5016 .lbs_ipc = sizeof(struct smack_known *),
5017 .lbs_msg_msg = sizeof(struct smack_known *),
5018 .lbs_superblock = sizeof(struct superblock_smack),
5019 .lbs_xattr_count = SMACK_INODE_INIT_XATTRS,
5020};
5021
5022static const struct lsm_id smack_lsmid = {
5023 .name = "smack",
5024 .id = LSM_ID_SMACK,
5025};
5026
5027static struct security_hook_list smack_hooks[] __ro_after_init = {
5028 LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
5029 LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
5030 LSM_HOOK_INIT(syslog, smack_syslog),
5031
5032 LSM_HOOK_INIT(fs_context_submount, smack_fs_context_submount),
5033 LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
5034 LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
5035
5036 LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
5037 LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
5038 LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
5039 LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
5040 LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
5041
5042 LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec),
5043
5044 LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
5045 LSM_HOOK_INIT(inode_init_security, smack_inode_init_security),
5046 LSM_HOOK_INIT(inode_link, smack_inode_link),
5047 LSM_HOOK_INIT(inode_unlink, smack_inode_unlink),
5048 LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir),
5049 LSM_HOOK_INIT(inode_rename, smack_inode_rename),
5050 LSM_HOOK_INIT(inode_permission, smack_inode_permission),
5051 LSM_HOOK_INIT(inode_setattr, smack_inode_setattr),
5052 LSM_HOOK_INIT(inode_getattr, smack_inode_getattr),
5053 LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr),
5054 LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr),
5055 LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr),
5056 LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr),
5057 LSM_HOOK_INIT(inode_set_acl, smack_inode_set_acl),
5058 LSM_HOOK_INIT(inode_get_acl, smack_inode_get_acl),
5059 LSM_HOOK_INIT(inode_remove_acl, smack_inode_remove_acl),
5060 LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity),
5061 LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity),
5062 LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity),
5063 LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid),
5064
5065 LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security),
5066 LSM_HOOK_INIT(file_ioctl, smack_file_ioctl),
5067 LSM_HOOK_INIT(file_ioctl_compat, smack_file_ioctl),
5068 LSM_HOOK_INIT(file_lock, smack_file_lock),
5069 LSM_HOOK_INIT(file_fcntl, smack_file_fcntl),
5070 LSM_HOOK_INIT(mmap_file, smack_mmap_file),
5071 LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
5072 LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner),
5073 LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask),
5074 LSM_HOOK_INIT(file_receive, smack_file_receive),
5075
5076 LSM_HOOK_INIT(file_open, smack_file_open),
5077
5078 LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank),
5079 LSM_HOOK_INIT(cred_free, smack_cred_free),
5080 LSM_HOOK_INIT(cred_prepare, smack_cred_prepare),
5081 LSM_HOOK_INIT(cred_transfer, smack_cred_transfer),
5082 LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid),
5083 LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as),
5084 LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as),
5085 LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
5086 LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
5087 LSM_HOOK_INIT(task_getsid, smack_task_getsid),
5088 LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj),
5089 LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj),
5090 LSM_HOOK_INIT(task_setnice, smack_task_setnice),
5091 LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
5092 LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),
5093 LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler),
5094 LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler),
5095 LSM_HOOK_INIT(task_movememory, smack_task_movememory),
5096 LSM_HOOK_INIT(task_kill, smack_task_kill),
5097 LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),
5098
5099 LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
5100 LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),
5101
5102 LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
5103
5104 LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security),
5105 LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate),
5106 LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl),
5107 LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd),
5108 LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv),
5109
5110 LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security),
5111 LSM_HOOK_INIT(shm_associate, smack_shm_associate),
5112 LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl),
5113 LSM_HOOK_INIT(shm_shmat, smack_shm_shmat),
5114
5115 LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security),
5116 LSM_HOOK_INIT(sem_associate, smack_sem_associate),
5117 LSM_HOOK_INIT(sem_semctl, smack_sem_semctl),
5118 LSM_HOOK_INIT(sem_semop, smack_sem_semop),
5119
5120 LSM_HOOK_INIT(d_instantiate, smack_d_instantiate),
5121
5122 LSM_HOOK_INIT(getselfattr, smack_getselfattr),
5123 LSM_HOOK_INIT(setselfattr, smack_setselfattr),
5124 LSM_HOOK_INIT(getprocattr, smack_getprocattr),
5125 LSM_HOOK_INIT(setprocattr, smack_setprocattr),
5126
5127 LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect),
5128 LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
5129
5130 LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
5131 LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair),
5132#ifdef SMACK_IPV6_PORT_LABELING
5133 LSM_HOOK_INIT(socket_bind, smack_socket_bind),
5134#endif
5135 LSM_HOOK_INIT(socket_connect, smack_socket_connect),
5136 LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
5137 LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
5138 LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
5139 LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
5140 LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
5141 LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
5142 LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security),
5143 LSM_HOOK_INIT(sock_graft, smack_sock_graft),
5144 LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
5145 LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
5146
5147 /* key management security hooks */
5148#ifdef CONFIG_KEYS
5149 LSM_HOOK_INIT(key_alloc, smack_key_alloc),
5150 LSM_HOOK_INIT(key_free, smack_key_free),
5151 LSM_HOOK_INIT(key_permission, smack_key_permission),
5152 LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
5153#ifdef CONFIG_KEY_NOTIFICATIONS
5154 LSM_HOOK_INIT(watch_key, smack_watch_key),
5155#endif
5156#endif /* CONFIG_KEYS */
5157
5158#ifdef CONFIG_WATCH_QUEUE
5159 LSM_HOOK_INIT(post_notification, smack_post_notification),
5160#endif
5161
5162 /* Audit hooks */
5163#ifdef CONFIG_AUDIT
5164 LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init),
5165 LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known),
5166 LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match),
5167#endif /* CONFIG_AUDIT */
5168
5169 LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
5170 LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
5171 LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
5172 LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
5173 LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
5174 LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
5175 LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up),
5176 LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr),
5177 LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as),
5178#ifdef CONFIG_IO_URING
5179 LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds),
5180 LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll),
5181 LSM_HOOK_INIT(uring_cmd, smack_uring_cmd),
5182#endif
5183};
5184
5185
5186static __init void init_smack_known_list(void)
5187{
5188 /*
5189 * Initialize rule list locks
5190 */
5191 mutex_init(&smack_known_huh.smk_rules_lock);
5192 mutex_init(&smack_known_hat.smk_rules_lock);
5193 mutex_init(&smack_known_floor.smk_rules_lock);
5194 mutex_init(&smack_known_star.smk_rules_lock);
5195 mutex_init(&smack_known_web.smk_rules_lock);
5196 /*
5197 * Initialize rule lists
5198 */
5199 INIT_LIST_HEAD(&smack_known_huh.smk_rules);
5200 INIT_LIST_HEAD(&smack_known_hat.smk_rules);
5201 INIT_LIST_HEAD(&smack_known_star.smk_rules);
5202 INIT_LIST_HEAD(&smack_known_floor.smk_rules);
5203 INIT_LIST_HEAD(&smack_known_web.smk_rules);
5204 /*
5205 * Create the known labels list
5206 */
5207 smk_insert_entry(&smack_known_huh);
5208 smk_insert_entry(&smack_known_hat);
5209 smk_insert_entry(&smack_known_star);
5210 smk_insert_entry(&smack_known_floor);
5211 smk_insert_entry(&smack_known_web);
5212}
5213
5214/**
5215 * smack_init - initialize the smack system
5216 *
5217 * Returns 0 on success, -ENOMEM is there's no memory
5218 */
5219static __init int smack_init(void)
5220{
5221 struct cred *cred = (struct cred *) current->cred;
5222 struct task_smack *tsp;
5223
5224 smack_rule_cache = KMEM_CACHE(smack_rule, 0);
5225 if (!smack_rule_cache)
5226 return -ENOMEM;
5227
5228 /*
5229 * Set the security state for the initial task.
5230 */
5231 tsp = smack_cred(cred);
5232 init_task_smack(tsp, &smack_known_floor, &smack_known_floor);
5233
5234 /*
5235 * Register with LSM
5236 */
5237 security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), &smack_lsmid);
5238 smack_enabled = 1;
5239
5240 pr_info("Smack: Initializing.\n");
5241#ifdef CONFIG_SECURITY_SMACK_NETFILTER
5242 pr_info("Smack: Netfilter enabled.\n");
5243#endif
5244#ifdef SMACK_IPV6_PORT_LABELING
5245 pr_info("Smack: IPv6 port labeling enabled.\n");
5246#endif
5247#ifdef SMACK_IPV6_SECMARK_LABELING
5248 pr_info("Smack: IPv6 Netfilter enabled.\n");
5249#endif
5250
5251 /* initialize the smack_known_list */
5252 init_smack_known_list();
5253
5254 return 0;
5255}
5256
5257/*
5258 * Smack requires early initialization in order to label
5259 * all processes and objects when they are created.
5260 */
5261DEFINE_LSM(smack) = {
5262 .name = "smack",
5263 .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
5264 .blobs = &smack_blob_sizes,
5265 .init = smack_init,
5266};