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