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