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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 <ext-jarkko.2.sakkinen@nokia.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 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2,
17 * as published by the Free Software Foundation.
18 */
19
20#include <linux/xattr.h>
21#include <linux/pagemap.h>
22#include <linux/mount.h>
23#include <linux/stat.h>
24#include <linux/kd.h>
25#include <asm/ioctls.h>
26#include <linux/ip.h>
27#include <linux/tcp.h>
28#include <linux/udp.h>
29#include <linux/slab.h>
30#include <linux/mutex.h>
31#include <linux/pipe_fs_i.h>
32#include <net/netlabel.h>
33#include <net/cipso_ipv4.h>
34#include <linux/audit.h>
35#include <linux/magic.h>
36#include <linux/dcache.h>
37#include "smack.h"
38
39#define task_security(task) (task_cred_xxx((task), security))
40
41#define TRANS_TRUE "TRUE"
42#define TRANS_TRUE_SIZE 4
43
44/**
45 * smk_fetch - Fetch the smack label from a file.
46 * @ip: a pointer to the inode
47 * @dp: a pointer to the dentry
48 *
49 * Returns a pointer to the master list entry for the Smack label
50 * or NULL if there was no label to fetch.
51 */
52static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
53{
54 int rc;
55 char in[SMK_LABELLEN];
56
57 if (ip->i_op->getxattr == NULL)
58 return NULL;
59
60 rc = ip->i_op->getxattr(dp, name, in, SMK_LABELLEN);
61 if (rc < 0)
62 return NULL;
63
64 return smk_import(in, rc);
65}
66
67/**
68 * new_inode_smack - allocate an inode security blob
69 * @smack: a pointer to the Smack label to use in the blob
70 *
71 * Returns the new blob or NULL if there's no memory available
72 */
73struct inode_smack *new_inode_smack(char *smack)
74{
75 struct inode_smack *isp;
76
77 isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
78 if (isp == NULL)
79 return NULL;
80
81 isp->smk_inode = smack;
82 isp->smk_flags = 0;
83 mutex_init(&isp->smk_lock);
84
85 return isp;
86}
87
88/**
89 * new_task_smack - allocate a task security blob
90 * @smack: a pointer to the Smack label to use in the blob
91 *
92 * Returns the new blob or NULL if there's no memory available
93 */
94static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
95{
96 struct task_smack *tsp;
97
98 tsp = kzalloc(sizeof(struct task_smack), gfp);
99 if (tsp == NULL)
100 return NULL;
101
102 tsp->smk_task = task;
103 tsp->smk_forked = forked;
104 INIT_LIST_HEAD(&tsp->smk_rules);
105 mutex_init(&tsp->smk_rules_lock);
106
107 return tsp;
108}
109
110/**
111 * smk_copy_rules - copy a rule set
112 * @nhead - new rules header pointer
113 * @ohead - old rules header pointer
114 *
115 * Returns 0 on success, -ENOMEM on error
116 */
117static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
118 gfp_t gfp)
119{
120 struct smack_rule *nrp;
121 struct smack_rule *orp;
122 int rc = 0;
123
124 INIT_LIST_HEAD(nhead);
125
126 list_for_each_entry_rcu(orp, ohead, list) {
127 nrp = kzalloc(sizeof(struct smack_rule), gfp);
128 if (nrp == NULL) {
129 rc = -ENOMEM;
130 break;
131 }
132 *nrp = *orp;
133 list_add_rcu(&nrp->list, nhead);
134 }
135 return rc;
136}
137
138/*
139 * LSM hooks.
140 * We he, that is fun!
141 */
142
143/**
144 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
145 * @ctp: child task pointer
146 * @mode: ptrace attachment mode
147 *
148 * Returns 0 if access is OK, an error code otherwise
149 *
150 * Do the capability checks, and require read and write.
151 */
152static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
153{
154 int rc;
155 struct smk_audit_info ad;
156 char *tsp;
157
158 rc = cap_ptrace_access_check(ctp, mode);
159 if (rc != 0)
160 return rc;
161
162 tsp = smk_of_task(task_security(ctp));
163 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
164 smk_ad_setfield_u_tsk(&ad, ctp);
165
166 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
167 return rc;
168}
169
170/**
171 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
172 * @ptp: parent task pointer
173 *
174 * Returns 0 if access is OK, an error code otherwise
175 *
176 * Do the capability checks, and require read and write.
177 */
178static int smack_ptrace_traceme(struct task_struct *ptp)
179{
180 int rc;
181 struct smk_audit_info ad;
182 char *tsp;
183
184 rc = cap_ptrace_traceme(ptp);
185 if (rc != 0)
186 return rc;
187
188 tsp = smk_of_task(task_security(ptp));
189 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
190 smk_ad_setfield_u_tsk(&ad, ptp);
191
192 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
193 return rc;
194}
195
196/**
197 * smack_syslog - Smack approval on syslog
198 * @type: message type
199 *
200 * Require that the task has the floor label
201 *
202 * Returns 0 on success, error code otherwise.
203 */
204static int smack_syslog(int typefrom_file)
205{
206 int rc = 0;
207 char *sp = smk_of_current();
208
209 if (capable(CAP_MAC_OVERRIDE))
210 return 0;
211
212 if (sp != smack_known_floor.smk_known)
213 rc = -EACCES;
214
215 return rc;
216}
217
218
219/*
220 * Superblock Hooks.
221 */
222
223/**
224 * smack_sb_alloc_security - allocate a superblock blob
225 * @sb: the superblock getting the blob
226 *
227 * Returns 0 on success or -ENOMEM on error.
228 */
229static int smack_sb_alloc_security(struct super_block *sb)
230{
231 struct superblock_smack *sbsp;
232
233 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
234
235 if (sbsp == NULL)
236 return -ENOMEM;
237
238 sbsp->smk_root = smack_known_floor.smk_known;
239 sbsp->smk_default = smack_known_floor.smk_known;
240 sbsp->smk_floor = smack_known_floor.smk_known;
241 sbsp->smk_hat = smack_known_hat.smk_known;
242 sbsp->smk_initialized = 0;
243 spin_lock_init(&sbsp->smk_sblock);
244
245 sb->s_security = sbsp;
246
247 return 0;
248}
249
250/**
251 * smack_sb_free_security - free a superblock blob
252 * @sb: the superblock getting the blob
253 *
254 */
255static void smack_sb_free_security(struct super_block *sb)
256{
257 kfree(sb->s_security);
258 sb->s_security = NULL;
259}
260
261/**
262 * smack_sb_copy_data - copy mount options data for processing
263 * @orig: where to start
264 * @smackopts: mount options string
265 *
266 * Returns 0 on success or -ENOMEM on error.
267 *
268 * Copy the Smack specific mount options out of the mount
269 * options list.
270 */
271static int smack_sb_copy_data(char *orig, char *smackopts)
272{
273 char *cp, *commap, *otheropts, *dp;
274
275 otheropts = (char *)get_zeroed_page(GFP_KERNEL);
276 if (otheropts == NULL)
277 return -ENOMEM;
278
279 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
280 if (strstr(cp, SMK_FSDEFAULT) == cp)
281 dp = smackopts;
282 else if (strstr(cp, SMK_FSFLOOR) == cp)
283 dp = smackopts;
284 else if (strstr(cp, SMK_FSHAT) == cp)
285 dp = smackopts;
286 else if (strstr(cp, SMK_FSROOT) == cp)
287 dp = smackopts;
288 else
289 dp = otheropts;
290
291 commap = strchr(cp, ',');
292 if (commap != NULL)
293 *commap = '\0';
294
295 if (*dp != '\0')
296 strcat(dp, ",");
297 strcat(dp, cp);
298 }
299
300 strcpy(orig, otheropts);
301 free_page((unsigned long)otheropts);
302
303 return 0;
304}
305
306/**
307 * smack_sb_kern_mount - Smack specific mount processing
308 * @sb: the file system superblock
309 * @flags: the mount flags
310 * @data: the smack mount options
311 *
312 * Returns 0 on success, an error code on failure
313 */
314static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
315{
316 struct dentry *root = sb->s_root;
317 struct inode *inode = root->d_inode;
318 struct superblock_smack *sp = sb->s_security;
319 struct inode_smack *isp;
320 char *op;
321 char *commap;
322 char *nsp;
323
324 spin_lock(&sp->smk_sblock);
325 if (sp->smk_initialized != 0) {
326 spin_unlock(&sp->smk_sblock);
327 return 0;
328 }
329 sp->smk_initialized = 1;
330 spin_unlock(&sp->smk_sblock);
331
332 for (op = data; op != NULL; op = commap) {
333 commap = strchr(op, ',');
334 if (commap != NULL)
335 *commap++ = '\0';
336
337 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
338 op += strlen(SMK_FSHAT);
339 nsp = smk_import(op, 0);
340 if (nsp != NULL)
341 sp->smk_hat = nsp;
342 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
343 op += strlen(SMK_FSFLOOR);
344 nsp = smk_import(op, 0);
345 if (nsp != NULL)
346 sp->smk_floor = nsp;
347 } else if (strncmp(op, SMK_FSDEFAULT,
348 strlen(SMK_FSDEFAULT)) == 0) {
349 op += strlen(SMK_FSDEFAULT);
350 nsp = smk_import(op, 0);
351 if (nsp != NULL)
352 sp->smk_default = nsp;
353 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
354 op += strlen(SMK_FSROOT);
355 nsp = smk_import(op, 0);
356 if (nsp != NULL)
357 sp->smk_root = nsp;
358 }
359 }
360
361 /*
362 * Initialize the root inode.
363 */
364 isp = inode->i_security;
365 if (isp == NULL)
366 inode->i_security = new_inode_smack(sp->smk_root);
367 else
368 isp->smk_inode = sp->smk_root;
369
370 return 0;
371}
372
373/**
374 * smack_sb_statfs - Smack check on statfs
375 * @dentry: identifies the file system in question
376 *
377 * Returns 0 if current can read the floor of the filesystem,
378 * and error code otherwise
379 */
380static int smack_sb_statfs(struct dentry *dentry)
381{
382 struct superblock_smack *sbp = dentry->d_sb->s_security;
383 int rc;
384 struct smk_audit_info ad;
385
386 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
387 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
388
389 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
390 return rc;
391}
392
393/**
394 * smack_sb_mount - Smack check for mounting
395 * @dev_name: unused
396 * @path: mount point
397 * @type: unused
398 * @flags: unused
399 * @data: unused
400 *
401 * Returns 0 if current can write the floor of the filesystem
402 * being mounted on, an error code otherwise.
403 */
404static int smack_sb_mount(char *dev_name, struct path *path,
405 char *type, unsigned long flags, void *data)
406{
407 struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
408 struct smk_audit_info ad;
409
410 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
411 smk_ad_setfield_u_fs_path(&ad, *path);
412
413 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
414}
415
416/**
417 * smack_sb_umount - Smack check for unmounting
418 * @mnt: file system to unmount
419 * @flags: unused
420 *
421 * Returns 0 if current can write the floor of the filesystem
422 * being unmounted, an error code otherwise.
423 */
424static int smack_sb_umount(struct vfsmount *mnt, int flags)
425{
426 struct superblock_smack *sbp;
427 struct smk_audit_info ad;
428 struct path path;
429
430 path.dentry = mnt->mnt_root;
431 path.mnt = mnt;
432
433 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
434 smk_ad_setfield_u_fs_path(&ad, path);
435
436 sbp = mnt->mnt_sb->s_security;
437 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
438}
439
440/*
441 * BPRM hooks
442 */
443
444static int smack_bprm_set_creds(struct linux_binprm *bprm)
445{
446 struct task_smack *tsp = bprm->cred->security;
447 struct inode_smack *isp;
448 struct dentry *dp;
449 int rc;
450
451 rc = cap_bprm_set_creds(bprm);
452 if (rc != 0)
453 return rc;
454
455 if (bprm->cred_prepared)
456 return 0;
457
458 if (bprm->file == NULL || bprm->file->f_dentry == NULL)
459 return 0;
460
461 dp = bprm->file->f_dentry;
462
463 if (dp->d_inode == NULL)
464 return 0;
465
466 isp = dp->d_inode->i_security;
467
468 if (isp->smk_task != NULL)
469 tsp->smk_task = isp->smk_task;
470
471 return 0;
472}
473
474/*
475 * Inode hooks
476 */
477
478/**
479 * smack_inode_alloc_security - allocate an inode blob
480 * @inode: the inode in need of a blob
481 *
482 * Returns 0 if it gets a blob, -ENOMEM otherwise
483 */
484static int smack_inode_alloc_security(struct inode *inode)
485{
486 inode->i_security = new_inode_smack(smk_of_current());
487 if (inode->i_security == NULL)
488 return -ENOMEM;
489 return 0;
490}
491
492/**
493 * smack_inode_free_security - free an inode blob
494 * @inode: the inode with a blob
495 *
496 * Clears the blob pointer in inode
497 */
498static void smack_inode_free_security(struct inode *inode)
499{
500 kfree(inode->i_security);
501 inode->i_security = NULL;
502}
503
504/**
505 * smack_inode_init_security - copy out the smack from an inode
506 * @inode: the inode
507 * @dir: unused
508 * @qstr: unused
509 * @name: where to put the attribute name
510 * @value: where to put the attribute value
511 * @len: where to put the length of the attribute
512 *
513 * Returns 0 if it all works out, -ENOMEM if there's no memory
514 */
515static int smack_inode_init_security(struct inode *inode, struct inode *dir,
516 const struct qstr *qstr, char **name,
517 void **value, size_t *len)
518{
519 char *isp = smk_of_inode(inode);
520 char *dsp = smk_of_inode(dir);
521 int may;
522
523 if (name) {
524 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
525 if (*name == NULL)
526 return -ENOMEM;
527 }
528
529 if (value) {
530 rcu_read_lock();
531 may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
532 rcu_read_unlock();
533
534 /*
535 * If the access rule allows transmutation and
536 * the directory requests transmutation then
537 * by all means transmute.
538 */
539 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
540 smk_inode_transmutable(dir))
541 isp = dsp;
542
543 *value = kstrdup(isp, GFP_KERNEL);
544 if (*value == NULL)
545 return -ENOMEM;
546 }
547
548 if (len)
549 *len = strlen(isp) + 1;
550
551 return 0;
552}
553
554/**
555 * smack_inode_link - Smack check on link
556 * @old_dentry: the existing object
557 * @dir: unused
558 * @new_dentry: the new object
559 *
560 * Returns 0 if access is permitted, an error code otherwise
561 */
562static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
563 struct dentry *new_dentry)
564{
565 char *isp;
566 struct smk_audit_info ad;
567 int rc;
568
569 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
570 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
571
572 isp = smk_of_inode(old_dentry->d_inode);
573 rc = smk_curacc(isp, MAY_WRITE, &ad);
574
575 if (rc == 0 && new_dentry->d_inode != NULL) {
576 isp = smk_of_inode(new_dentry->d_inode);
577 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
578 rc = smk_curacc(isp, MAY_WRITE, &ad);
579 }
580
581 return rc;
582}
583
584/**
585 * smack_inode_unlink - Smack check on inode deletion
586 * @dir: containing directory object
587 * @dentry: file to unlink
588 *
589 * Returns 0 if current can write the containing directory
590 * and the object, error code otherwise
591 */
592static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
593{
594 struct inode *ip = dentry->d_inode;
595 struct smk_audit_info ad;
596 int rc;
597
598 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
599 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
600
601 /*
602 * You need write access to the thing you're unlinking
603 */
604 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
605 if (rc == 0) {
606 /*
607 * You also need write access to the containing directory
608 */
609 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
610 smk_ad_setfield_u_fs_inode(&ad, dir);
611 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
612 }
613 return rc;
614}
615
616/**
617 * smack_inode_rmdir - Smack check on directory deletion
618 * @dir: containing directory object
619 * @dentry: directory to unlink
620 *
621 * Returns 0 if current can write the containing directory
622 * and the directory, error code otherwise
623 */
624static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
625{
626 struct smk_audit_info ad;
627 int rc;
628
629 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
630 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
631
632 /*
633 * You need write access to the thing you're removing
634 */
635 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
636 if (rc == 0) {
637 /*
638 * You also need write access to the containing directory
639 */
640 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
641 smk_ad_setfield_u_fs_inode(&ad, dir);
642 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
643 }
644
645 return rc;
646}
647
648/**
649 * smack_inode_rename - Smack check on rename
650 * @old_inode: the old directory
651 * @old_dentry: unused
652 * @new_inode: the new directory
653 * @new_dentry: unused
654 *
655 * Read and write access is required on both the old and
656 * new directories.
657 *
658 * Returns 0 if access is permitted, an error code otherwise
659 */
660static int smack_inode_rename(struct inode *old_inode,
661 struct dentry *old_dentry,
662 struct inode *new_inode,
663 struct dentry *new_dentry)
664{
665 int rc;
666 char *isp;
667 struct smk_audit_info ad;
668
669 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
670 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
671
672 isp = smk_of_inode(old_dentry->d_inode);
673 rc = smk_curacc(isp, MAY_READWRITE, &ad);
674
675 if (rc == 0 && new_dentry->d_inode != NULL) {
676 isp = smk_of_inode(new_dentry->d_inode);
677 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
678 rc = smk_curacc(isp, MAY_READWRITE, &ad);
679 }
680 return rc;
681}
682
683/**
684 * smack_inode_permission - Smack version of permission()
685 * @inode: the inode in question
686 * @mask: the access requested
687 *
688 * This is the important Smack hook.
689 *
690 * Returns 0 if access is permitted, -EACCES otherwise
691 */
692static int smack_inode_permission(struct inode *inode, int mask)
693{
694 struct smk_audit_info ad;
695 int no_block = mask & MAY_NOT_BLOCK;
696
697 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
698 /*
699 * No permission to check. Existence test. Yup, it's there.
700 */
701 if (mask == 0)
702 return 0;
703
704 /* May be droppable after audit */
705 if (no_block)
706 return -ECHILD;
707 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
708 smk_ad_setfield_u_fs_inode(&ad, inode);
709 return smk_curacc(smk_of_inode(inode), mask, &ad);
710}
711
712/**
713 * smack_inode_setattr - Smack check for setting attributes
714 * @dentry: the object
715 * @iattr: for the force flag
716 *
717 * Returns 0 if access is permitted, an error code otherwise
718 */
719static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
720{
721 struct smk_audit_info ad;
722 /*
723 * Need to allow for clearing the setuid bit.
724 */
725 if (iattr->ia_valid & ATTR_FORCE)
726 return 0;
727 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
728 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
729
730 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
731}
732
733/**
734 * smack_inode_getattr - Smack check for getting attributes
735 * @mnt: unused
736 * @dentry: the object
737 *
738 * Returns 0 if access is permitted, an error code otherwise
739 */
740static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
741{
742 struct smk_audit_info ad;
743 struct path path;
744
745 path.dentry = dentry;
746 path.mnt = mnt;
747
748 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
749 smk_ad_setfield_u_fs_path(&ad, path);
750 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
751}
752
753/**
754 * smack_inode_setxattr - Smack check for setting xattrs
755 * @dentry: the object
756 * @name: name of the attribute
757 * @value: unused
758 * @size: unused
759 * @flags: unused
760 *
761 * This protects the Smack attribute explicitly.
762 *
763 * Returns 0 if access is permitted, an error code otherwise
764 */
765static int smack_inode_setxattr(struct dentry *dentry, const char *name,
766 const void *value, size_t size, int flags)
767{
768 struct smk_audit_info ad;
769 int rc = 0;
770
771 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
772 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
773 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
774 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
775 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
776 if (!capable(CAP_MAC_ADMIN))
777 rc = -EPERM;
778 /*
779 * check label validity here so import wont fail on
780 * post_setxattr
781 */
782 if (size == 0 || size >= SMK_LABELLEN ||
783 smk_import(value, size) == NULL)
784 rc = -EINVAL;
785 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
786 if (!capable(CAP_MAC_ADMIN))
787 rc = -EPERM;
788 if (size != TRANS_TRUE_SIZE ||
789 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
790 rc = -EINVAL;
791 } else
792 rc = cap_inode_setxattr(dentry, name, value, size, flags);
793
794 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
795 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
796
797 if (rc == 0)
798 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
799
800 return rc;
801}
802
803/**
804 * smack_inode_post_setxattr - Apply the Smack update approved above
805 * @dentry: object
806 * @name: attribute name
807 * @value: attribute value
808 * @size: attribute size
809 * @flags: unused
810 *
811 * Set the pointer in the inode blob to the entry found
812 * in the master label list.
813 */
814static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
815 const void *value, size_t size, int flags)
816{
817 char *nsp;
818 struct inode_smack *isp = dentry->d_inode->i_security;
819
820 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
821 nsp = smk_import(value, size);
822 if (nsp != NULL)
823 isp->smk_inode = nsp;
824 else
825 isp->smk_inode = smack_known_invalid.smk_known;
826 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
827 nsp = smk_import(value, size);
828 if (nsp != NULL)
829 isp->smk_task = nsp;
830 else
831 isp->smk_task = smack_known_invalid.smk_known;
832 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
833 nsp = smk_import(value, size);
834 if (nsp != NULL)
835 isp->smk_mmap = nsp;
836 else
837 isp->smk_mmap = smack_known_invalid.smk_known;
838 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
839 isp->smk_flags |= SMK_INODE_TRANSMUTE;
840
841 return;
842}
843
844/*
845 * smack_inode_getxattr - Smack check on getxattr
846 * @dentry: the object
847 * @name: unused
848 *
849 * Returns 0 if access is permitted, an error code otherwise
850 */
851static int smack_inode_getxattr(struct dentry *dentry, const char *name)
852{
853 struct smk_audit_info ad;
854
855 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
856 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
857
858 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
859}
860
861/*
862 * smack_inode_removexattr - Smack check on removexattr
863 * @dentry: the object
864 * @name: name of the attribute
865 *
866 * Removing the Smack attribute requires CAP_MAC_ADMIN
867 *
868 * Returns 0 if access is permitted, an error code otherwise
869 */
870static int smack_inode_removexattr(struct dentry *dentry, const char *name)
871{
872 struct inode_smack *isp;
873 struct smk_audit_info ad;
874 int rc = 0;
875
876 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
877 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
878 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
879 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
880 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
881 strcmp(name, XATTR_NAME_SMACKMMAP)) {
882 if (!capable(CAP_MAC_ADMIN))
883 rc = -EPERM;
884 } else
885 rc = cap_inode_removexattr(dentry, name);
886
887 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
888 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
889 if (rc == 0)
890 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
891
892 if (rc == 0) {
893 isp = dentry->d_inode->i_security;
894 isp->smk_task = NULL;
895 isp->smk_mmap = NULL;
896 }
897
898 return rc;
899}
900
901/**
902 * smack_inode_getsecurity - get smack xattrs
903 * @inode: the object
904 * @name: attribute name
905 * @buffer: where to put the result
906 * @alloc: unused
907 *
908 * Returns the size of the attribute or an error code
909 */
910static int smack_inode_getsecurity(const struct inode *inode,
911 const char *name, void **buffer,
912 bool alloc)
913{
914 struct socket_smack *ssp;
915 struct socket *sock;
916 struct super_block *sbp;
917 struct inode *ip = (struct inode *)inode;
918 char *isp;
919 int ilen;
920 int rc = 0;
921
922 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
923 isp = smk_of_inode(inode);
924 ilen = strlen(isp) + 1;
925 *buffer = isp;
926 return ilen;
927 }
928
929 /*
930 * The rest of the Smack xattrs are only on sockets.
931 */
932 sbp = ip->i_sb;
933 if (sbp->s_magic != SOCKFS_MAGIC)
934 return -EOPNOTSUPP;
935
936 sock = SOCKET_I(ip);
937 if (sock == NULL || sock->sk == NULL)
938 return -EOPNOTSUPP;
939
940 ssp = sock->sk->sk_security;
941
942 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
943 isp = ssp->smk_in;
944 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
945 isp = ssp->smk_out;
946 else
947 return -EOPNOTSUPP;
948
949 ilen = strlen(isp) + 1;
950 if (rc == 0) {
951 *buffer = isp;
952 rc = ilen;
953 }
954
955 return rc;
956}
957
958
959/**
960 * smack_inode_listsecurity - list the Smack attributes
961 * @inode: the object
962 * @buffer: where they go
963 * @buffer_size: size of buffer
964 *
965 * Returns 0 on success, -EINVAL otherwise
966 */
967static int smack_inode_listsecurity(struct inode *inode, char *buffer,
968 size_t buffer_size)
969{
970 int len = strlen(XATTR_NAME_SMACK);
971
972 if (buffer != NULL && len <= buffer_size) {
973 memcpy(buffer, XATTR_NAME_SMACK, len);
974 return len;
975 }
976 return -EINVAL;
977}
978
979/**
980 * smack_inode_getsecid - Extract inode's security id
981 * @inode: inode to extract the info from
982 * @secid: where result will be saved
983 */
984static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
985{
986 struct inode_smack *isp = inode->i_security;
987
988 *secid = smack_to_secid(isp->smk_inode);
989}
990
991/*
992 * File Hooks
993 */
994
995/**
996 * smack_file_permission - Smack check on file operations
997 * @file: unused
998 * @mask: unused
999 *
1000 * Returns 0
1001 *
1002 * Should access checks be done on each read or write?
1003 * UNICOS and SELinux say yes.
1004 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1005 *
1006 * I'll say no for now. Smack does not do the frequent
1007 * label changing that SELinux does.
1008 */
1009static int smack_file_permission(struct file *file, int mask)
1010{
1011 return 0;
1012}
1013
1014/**
1015 * smack_file_alloc_security - assign a file security blob
1016 * @file: the object
1017 *
1018 * The security blob for a file is a pointer to the master
1019 * label list, so no allocation is done.
1020 *
1021 * Returns 0
1022 */
1023static int smack_file_alloc_security(struct file *file)
1024{
1025 file->f_security = smk_of_current();
1026 return 0;
1027}
1028
1029/**
1030 * smack_file_free_security - clear a file security blob
1031 * @file: the object
1032 *
1033 * The security blob for a file is a pointer to the master
1034 * label list, so no memory is freed.
1035 */
1036static void smack_file_free_security(struct file *file)
1037{
1038 file->f_security = NULL;
1039}
1040
1041/**
1042 * smack_file_ioctl - Smack check on ioctls
1043 * @file: the object
1044 * @cmd: what to do
1045 * @arg: unused
1046 *
1047 * Relies heavily on the correct use of the ioctl command conventions.
1048 *
1049 * Returns 0 if allowed, error code otherwise
1050 */
1051static int smack_file_ioctl(struct file *file, unsigned int cmd,
1052 unsigned long arg)
1053{
1054 int rc = 0;
1055 struct smk_audit_info ad;
1056
1057 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1058 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1059
1060 if (_IOC_DIR(cmd) & _IOC_WRITE)
1061 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1062
1063 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1064 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1065
1066 return rc;
1067}
1068
1069/**
1070 * smack_file_lock - Smack check on file locking
1071 * @file: the object
1072 * @cmd: unused
1073 *
1074 * Returns 0 if current has write access, error code otherwise
1075 */
1076static int smack_file_lock(struct file *file, unsigned int cmd)
1077{
1078 struct smk_audit_info ad;
1079
1080 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1081 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1082 return smk_curacc(file->f_security, MAY_WRITE, &ad);
1083}
1084
1085/**
1086 * smack_file_fcntl - Smack check on fcntl
1087 * @file: the object
1088 * @cmd: what action to check
1089 * @arg: unused
1090 *
1091 * Returns 0 if current has access, error code otherwise
1092 */
1093static int smack_file_fcntl(struct file *file, unsigned int cmd,
1094 unsigned long arg)
1095{
1096 struct smk_audit_info ad;
1097 int rc;
1098
1099 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1100 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1101
1102 switch (cmd) {
1103 case F_DUPFD:
1104 case F_GETFD:
1105 case F_GETFL:
1106 case F_GETLK:
1107 case F_GETOWN:
1108 case F_GETSIG:
1109 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1110 break;
1111 case F_SETFD:
1112 case F_SETFL:
1113 case F_SETLK:
1114 case F_SETLKW:
1115 case F_SETOWN:
1116 case F_SETSIG:
1117 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1118 break;
1119 default:
1120 rc = smk_curacc(file->f_security, MAY_READWRITE, &ad);
1121 }
1122
1123 return rc;
1124}
1125
1126/**
1127 * smack_file_mmap :
1128 * Check permissions for a mmap operation. The @file may be NULL, e.g.
1129 * if mapping anonymous memory.
1130 * @file contains the file structure for file to map (may be NULL).
1131 * @reqprot contains the protection requested by the application.
1132 * @prot contains the protection that will be applied by the kernel.
1133 * @flags contains the operational flags.
1134 * Return 0 if permission is granted.
1135 */
1136static int smack_file_mmap(struct file *file,
1137 unsigned long reqprot, unsigned long prot,
1138 unsigned long flags, unsigned long addr,
1139 unsigned long addr_only)
1140{
1141 struct smack_rule *srp;
1142 struct task_smack *tsp;
1143 char *sp;
1144 char *msmack;
1145 char *osmack;
1146 struct inode_smack *isp;
1147 struct dentry *dp;
1148 int may;
1149 int mmay;
1150 int tmay;
1151 int rc;
1152
1153 /* do DAC check on address space usage */
1154 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
1155 if (rc || addr_only)
1156 return rc;
1157
1158 if (file == NULL || file->f_dentry == NULL)
1159 return 0;
1160
1161 dp = file->f_dentry;
1162
1163 if (dp->d_inode == NULL)
1164 return 0;
1165
1166 isp = dp->d_inode->i_security;
1167 if (isp->smk_mmap == NULL)
1168 return 0;
1169 msmack = isp->smk_mmap;
1170
1171 tsp = current_security();
1172 sp = smk_of_current();
1173 rc = 0;
1174
1175 rcu_read_lock();
1176 /*
1177 * For each Smack rule associated with the subject
1178 * label verify that the SMACK64MMAP also has access
1179 * to that rule's object label.
1180 *
1181 * Because neither of the labels comes
1182 * from the networking code it is sufficient
1183 * to compare pointers.
1184 */
1185 list_for_each_entry_rcu(srp, &smack_rule_list, list) {
1186 if (srp->smk_subject != sp)
1187 continue;
1188
1189 osmack = srp->smk_object;
1190 /*
1191 * Matching labels always allows access.
1192 */
1193 if (msmack == osmack)
1194 continue;
1195 /*
1196 * If there is a matching local rule take
1197 * that into account as well.
1198 */
1199 may = smk_access_entry(srp->smk_subject, osmack,
1200 &tsp->smk_rules);
1201 if (may == -ENOENT)
1202 may = srp->smk_access;
1203 else
1204 may &= srp->smk_access;
1205 /*
1206 * If may is zero the SMACK64MMAP subject can't
1207 * possibly have less access.
1208 */
1209 if (may == 0)
1210 continue;
1211
1212 /*
1213 * Fetch the global list entry.
1214 * If there isn't one a SMACK64MMAP subject
1215 * can't have as much access as current.
1216 */
1217 mmay = smk_access_entry(msmack, osmack, &smack_rule_list);
1218 if (mmay == -ENOENT) {
1219 rc = -EACCES;
1220 break;
1221 }
1222 /*
1223 * If there is a local entry it modifies the
1224 * potential access, too.
1225 */
1226 tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules);
1227 if (tmay != -ENOENT)
1228 mmay &= tmay;
1229
1230 /*
1231 * If there is any access available to current that is
1232 * not available to a SMACK64MMAP subject
1233 * deny access.
1234 */
1235 if ((may | mmay) != mmay) {
1236 rc = -EACCES;
1237 break;
1238 }
1239 }
1240
1241 rcu_read_unlock();
1242
1243 return rc;
1244}
1245
1246/**
1247 * smack_file_set_fowner - set the file security blob value
1248 * @file: object in question
1249 *
1250 * Returns 0
1251 * Further research may be required on this one.
1252 */
1253static int smack_file_set_fowner(struct file *file)
1254{
1255 file->f_security = smk_of_current();
1256 return 0;
1257}
1258
1259/**
1260 * smack_file_send_sigiotask - Smack on sigio
1261 * @tsk: The target task
1262 * @fown: the object the signal come from
1263 * @signum: unused
1264 *
1265 * Allow a privileged task to get signals even if it shouldn't
1266 *
1267 * Returns 0 if a subject with the object's smack could
1268 * write to the task, an error code otherwise.
1269 */
1270static int smack_file_send_sigiotask(struct task_struct *tsk,
1271 struct fown_struct *fown, int signum)
1272{
1273 struct file *file;
1274 int rc;
1275 char *tsp = smk_of_task(tsk->cred->security);
1276 struct smk_audit_info ad;
1277
1278 /*
1279 * struct fown_struct is never outside the context of a struct file
1280 */
1281 file = container_of(fown, struct file, f_owner);
1282
1283 /* we don't log here as rc can be overriden */
1284 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1285 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1286 rc = 0;
1287
1288 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1289 smk_ad_setfield_u_tsk(&ad, tsk);
1290 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1291 return rc;
1292}
1293
1294/**
1295 * smack_file_receive - Smack file receive check
1296 * @file: the object
1297 *
1298 * Returns 0 if current has access, error code otherwise
1299 */
1300static int smack_file_receive(struct file *file)
1301{
1302 int may = 0;
1303 struct smk_audit_info ad;
1304
1305 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1306 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1307 /*
1308 * This code relies on bitmasks.
1309 */
1310 if (file->f_mode & FMODE_READ)
1311 may = MAY_READ;
1312 if (file->f_mode & FMODE_WRITE)
1313 may |= MAY_WRITE;
1314
1315 return smk_curacc(file->f_security, may, &ad);
1316}
1317
1318/*
1319 * Task hooks
1320 */
1321
1322/**
1323 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1324 * @new: the new credentials
1325 * @gfp: the atomicity of any memory allocations
1326 *
1327 * Prepare a blank set of credentials for modification. This must allocate all
1328 * the memory the LSM module might require such that cred_transfer() can
1329 * complete without error.
1330 */
1331static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1332{
1333 struct task_smack *tsp;
1334
1335 tsp = new_task_smack(NULL, NULL, gfp);
1336 if (tsp == NULL)
1337 return -ENOMEM;
1338
1339 cred->security = tsp;
1340
1341 return 0;
1342}
1343
1344
1345/**
1346 * smack_cred_free - "free" task-level security credentials
1347 * @cred: the credentials in question
1348 *
1349 */
1350static void smack_cred_free(struct cred *cred)
1351{
1352 struct task_smack *tsp = cred->security;
1353 struct smack_rule *rp;
1354 struct list_head *l;
1355 struct list_head *n;
1356
1357 if (tsp == NULL)
1358 return;
1359 cred->security = NULL;
1360
1361 list_for_each_safe(l, n, &tsp->smk_rules) {
1362 rp = list_entry(l, struct smack_rule, list);
1363 list_del(&rp->list);
1364 kfree(rp);
1365 }
1366 kfree(tsp);
1367}
1368
1369/**
1370 * smack_cred_prepare - prepare new set of credentials for modification
1371 * @new: the new credentials
1372 * @old: the original credentials
1373 * @gfp: the atomicity of any memory allocations
1374 *
1375 * Prepare a new set of credentials for modification.
1376 */
1377static int smack_cred_prepare(struct cred *new, const struct cred *old,
1378 gfp_t gfp)
1379{
1380 struct task_smack *old_tsp = old->security;
1381 struct task_smack *new_tsp;
1382 int rc;
1383
1384 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1385 if (new_tsp == NULL)
1386 return -ENOMEM;
1387
1388 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1389 if (rc != 0)
1390 return rc;
1391
1392 new->security = new_tsp;
1393 return 0;
1394}
1395
1396/**
1397 * smack_cred_transfer - Transfer the old credentials to the new credentials
1398 * @new: the new credentials
1399 * @old: the original credentials
1400 *
1401 * Fill in a set of blank credentials from another set of credentials.
1402 */
1403static void smack_cred_transfer(struct cred *new, const struct cred *old)
1404{
1405 struct task_smack *old_tsp = old->security;
1406 struct task_smack *new_tsp = new->security;
1407
1408 new_tsp->smk_task = old_tsp->smk_task;
1409 new_tsp->smk_forked = old_tsp->smk_task;
1410 mutex_init(&new_tsp->smk_rules_lock);
1411 INIT_LIST_HEAD(&new_tsp->smk_rules);
1412
1413
1414 /* cbs copy rule list */
1415}
1416
1417/**
1418 * smack_kernel_act_as - Set the subjective context in a set of credentials
1419 * @new: points to the set of credentials to be modified.
1420 * @secid: specifies the security ID to be set
1421 *
1422 * Set the security data for a kernel service.
1423 */
1424static int smack_kernel_act_as(struct cred *new, u32 secid)
1425{
1426 struct task_smack *new_tsp = new->security;
1427 char *smack = smack_from_secid(secid);
1428
1429 if (smack == NULL)
1430 return -EINVAL;
1431
1432 new_tsp->smk_task = smack;
1433 return 0;
1434}
1435
1436/**
1437 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1438 * @new: points to the set of credentials to be modified
1439 * @inode: points to the inode to use as a reference
1440 *
1441 * Set the file creation context in a set of credentials to the same
1442 * as the objective context of the specified inode
1443 */
1444static int smack_kernel_create_files_as(struct cred *new,
1445 struct inode *inode)
1446{
1447 struct inode_smack *isp = inode->i_security;
1448 struct task_smack *tsp = new->security;
1449
1450 tsp->smk_forked = isp->smk_inode;
1451 tsp->smk_task = isp->smk_inode;
1452 return 0;
1453}
1454
1455/**
1456 * smk_curacc_on_task - helper to log task related access
1457 * @p: the task object
1458 * @access : the access requested
1459 *
1460 * Return 0 if access is permitted
1461 */
1462static int smk_curacc_on_task(struct task_struct *p, int access)
1463{
1464 struct smk_audit_info ad;
1465
1466 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1467 smk_ad_setfield_u_tsk(&ad, p);
1468 return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1469}
1470
1471/**
1472 * smack_task_setpgid - Smack check on setting pgid
1473 * @p: the task object
1474 * @pgid: unused
1475 *
1476 * Return 0 if write access is permitted
1477 */
1478static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1479{
1480 return smk_curacc_on_task(p, MAY_WRITE);
1481}
1482
1483/**
1484 * smack_task_getpgid - Smack access check for getpgid
1485 * @p: the object task
1486 *
1487 * Returns 0 if current can read the object task, error code otherwise
1488 */
1489static int smack_task_getpgid(struct task_struct *p)
1490{
1491 return smk_curacc_on_task(p, MAY_READ);
1492}
1493
1494/**
1495 * smack_task_getsid - Smack access check for getsid
1496 * @p: the object task
1497 *
1498 * Returns 0 if current can read the object task, error code otherwise
1499 */
1500static int smack_task_getsid(struct task_struct *p)
1501{
1502 return smk_curacc_on_task(p, MAY_READ);
1503}
1504
1505/**
1506 * smack_task_getsecid - get the secid of the task
1507 * @p: the object task
1508 * @secid: where to put the result
1509 *
1510 * Sets the secid to contain a u32 version of the smack label.
1511 */
1512static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1513{
1514 *secid = smack_to_secid(smk_of_task(task_security(p)));
1515}
1516
1517/**
1518 * smack_task_setnice - Smack check on setting nice
1519 * @p: the task object
1520 * @nice: unused
1521 *
1522 * Return 0 if write access is permitted
1523 */
1524static int smack_task_setnice(struct task_struct *p, int nice)
1525{
1526 int rc;
1527
1528 rc = cap_task_setnice(p, nice);
1529 if (rc == 0)
1530 rc = smk_curacc_on_task(p, MAY_WRITE);
1531 return rc;
1532}
1533
1534/**
1535 * smack_task_setioprio - Smack check on setting ioprio
1536 * @p: the task object
1537 * @ioprio: unused
1538 *
1539 * Return 0 if write access is permitted
1540 */
1541static int smack_task_setioprio(struct task_struct *p, int ioprio)
1542{
1543 int rc;
1544
1545 rc = cap_task_setioprio(p, ioprio);
1546 if (rc == 0)
1547 rc = smk_curacc_on_task(p, MAY_WRITE);
1548 return rc;
1549}
1550
1551/**
1552 * smack_task_getioprio - Smack check on reading ioprio
1553 * @p: the task object
1554 *
1555 * Return 0 if read access is permitted
1556 */
1557static int smack_task_getioprio(struct task_struct *p)
1558{
1559 return smk_curacc_on_task(p, MAY_READ);
1560}
1561
1562/**
1563 * smack_task_setscheduler - Smack check on setting scheduler
1564 * @p: the task object
1565 * @policy: unused
1566 * @lp: unused
1567 *
1568 * Return 0 if read access is permitted
1569 */
1570static int smack_task_setscheduler(struct task_struct *p)
1571{
1572 int rc;
1573
1574 rc = cap_task_setscheduler(p);
1575 if (rc == 0)
1576 rc = smk_curacc_on_task(p, MAY_WRITE);
1577 return rc;
1578}
1579
1580/**
1581 * smack_task_getscheduler - Smack check on reading scheduler
1582 * @p: the task object
1583 *
1584 * Return 0 if read access is permitted
1585 */
1586static int smack_task_getscheduler(struct task_struct *p)
1587{
1588 return smk_curacc_on_task(p, MAY_READ);
1589}
1590
1591/**
1592 * smack_task_movememory - Smack check on moving memory
1593 * @p: the task object
1594 *
1595 * Return 0 if write access is permitted
1596 */
1597static int smack_task_movememory(struct task_struct *p)
1598{
1599 return smk_curacc_on_task(p, MAY_WRITE);
1600}
1601
1602/**
1603 * smack_task_kill - Smack check on signal delivery
1604 * @p: the task object
1605 * @info: unused
1606 * @sig: unused
1607 * @secid: identifies the smack to use in lieu of current's
1608 *
1609 * Return 0 if write access is permitted
1610 *
1611 * The secid behavior is an artifact of an SELinux hack
1612 * in the USB code. Someday it may go away.
1613 */
1614static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1615 int sig, u32 secid)
1616{
1617 struct smk_audit_info ad;
1618
1619 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1620 smk_ad_setfield_u_tsk(&ad, p);
1621 /*
1622 * Sending a signal requires that the sender
1623 * can write the receiver.
1624 */
1625 if (secid == 0)
1626 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1627 &ad);
1628 /*
1629 * If the secid isn't 0 we're dealing with some USB IO
1630 * specific behavior. This is not clean. For one thing
1631 * we can't take privilege into account.
1632 */
1633 return smk_access(smack_from_secid(secid),
1634 smk_of_task(task_security(p)), MAY_WRITE, &ad);
1635}
1636
1637/**
1638 * smack_task_wait - Smack access check for waiting
1639 * @p: task to wait for
1640 *
1641 * Returns 0 if current can wait for p, error code otherwise
1642 */
1643static int smack_task_wait(struct task_struct *p)
1644{
1645 struct smk_audit_info ad;
1646 char *sp = smk_of_current();
1647 char *tsp = smk_of_forked(task_security(p));
1648 int rc;
1649
1650 /* we don't log here, we can be overriden */
1651 rc = smk_access(tsp, sp, MAY_WRITE, NULL);
1652 if (rc == 0)
1653 goto out_log;
1654
1655 /*
1656 * Allow the operation to succeed if either task
1657 * has privilege to perform operations that might
1658 * account for the smack labels having gotten to
1659 * be different in the first place.
1660 *
1661 * This breaks the strict subject/object access
1662 * control ideal, taking the object's privilege
1663 * state into account in the decision as well as
1664 * the smack value.
1665 */
1666 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1667 rc = 0;
1668 /* we log only if we didn't get overriden */
1669 out_log:
1670 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1671 smk_ad_setfield_u_tsk(&ad, p);
1672 smack_log(tsp, sp, MAY_WRITE, rc, &ad);
1673 return rc;
1674}
1675
1676/**
1677 * smack_task_to_inode - copy task smack into the inode blob
1678 * @p: task to copy from
1679 * @inode: inode to copy to
1680 *
1681 * Sets the smack pointer in the inode security blob
1682 */
1683static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1684{
1685 struct inode_smack *isp = inode->i_security;
1686 isp->smk_inode = smk_of_task(task_security(p));
1687}
1688
1689/*
1690 * Socket hooks.
1691 */
1692
1693/**
1694 * smack_sk_alloc_security - Allocate a socket blob
1695 * @sk: the socket
1696 * @family: unused
1697 * @gfp_flags: memory allocation flags
1698 *
1699 * Assign Smack pointers to current
1700 *
1701 * Returns 0 on success, -ENOMEM is there's no memory
1702 */
1703static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1704{
1705 char *csp = smk_of_current();
1706 struct socket_smack *ssp;
1707
1708 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1709 if (ssp == NULL)
1710 return -ENOMEM;
1711
1712 ssp->smk_in = csp;
1713 ssp->smk_out = csp;
1714 ssp->smk_packet[0] = '\0';
1715
1716 sk->sk_security = ssp;
1717
1718 return 0;
1719}
1720
1721/**
1722 * smack_sk_free_security - Free a socket blob
1723 * @sk: the socket
1724 *
1725 * Clears the blob pointer
1726 */
1727static void smack_sk_free_security(struct sock *sk)
1728{
1729 kfree(sk->sk_security);
1730}
1731
1732/**
1733* smack_host_label - check host based restrictions
1734* @sip: the object end
1735*
1736* looks for host based access restrictions
1737*
1738* This version will only be appropriate for really small sets of single label
1739* hosts. The caller is responsible for ensuring that the RCU read lock is
1740* taken before calling this function.
1741*
1742* Returns the label of the far end or NULL if it's not special.
1743*/
1744static char *smack_host_label(struct sockaddr_in *sip)
1745{
1746 struct smk_netlbladdr *snp;
1747 struct in_addr *siap = &sip->sin_addr;
1748
1749 if (siap->s_addr == 0)
1750 return NULL;
1751
1752 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1753 /*
1754 * we break after finding the first match because
1755 * the list is sorted from longest to shortest mask
1756 * so we have found the most specific match
1757 */
1758 if ((&snp->smk_host.sin_addr)->s_addr ==
1759 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1760 /* we have found the special CIPSO option */
1761 if (snp->smk_label == smack_cipso_option)
1762 return NULL;
1763 return snp->smk_label;
1764 }
1765
1766 return NULL;
1767}
1768
1769/**
1770 * smack_set_catset - convert a capset to netlabel mls categories
1771 * @catset: the Smack categories
1772 * @sap: where to put the netlabel categories
1773 *
1774 * Allocates and fills attr.mls.cat
1775 */
1776static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1777{
1778 unsigned char *cp;
1779 unsigned char m;
1780 int cat;
1781 int rc;
1782 int byte;
1783
1784 if (!catset)
1785 return;
1786
1787 sap->flags |= NETLBL_SECATTR_MLS_CAT;
1788 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1789 sap->attr.mls.cat->startbit = 0;
1790
1791 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1792 for (m = 0x80; m != 0; m >>= 1, cat++) {
1793 if ((m & *cp) == 0)
1794 continue;
1795 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1796 cat, GFP_ATOMIC);
1797 }
1798}
1799
1800/**
1801 * smack_to_secattr - fill a secattr from a smack value
1802 * @smack: the smack value
1803 * @nlsp: where the result goes
1804 *
1805 * Casey says that CIPSO is good enough for now.
1806 * It can be used to effect.
1807 * It can also be abused to effect when necessary.
1808 * Apologies to the TSIG group in general and GW in particular.
1809 */
1810static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1811{
1812 struct smack_cipso cipso;
1813 int rc;
1814
1815 nlsp->domain = smack;
1816 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1817
1818 rc = smack_to_cipso(smack, &cipso);
1819 if (rc == 0) {
1820 nlsp->attr.mls.lvl = cipso.smk_level;
1821 smack_set_catset(cipso.smk_catset, nlsp);
1822 } else {
1823 nlsp->attr.mls.lvl = smack_cipso_direct;
1824 smack_set_catset(smack, nlsp);
1825 }
1826}
1827
1828/**
1829 * smack_netlabel - Set the secattr on a socket
1830 * @sk: the socket
1831 * @labeled: socket label scheme
1832 *
1833 * Convert the outbound smack value (smk_out) to a
1834 * secattr and attach it to the socket.
1835 *
1836 * Returns 0 on success or an error code
1837 */
1838static int smack_netlabel(struct sock *sk, int labeled)
1839{
1840 struct socket_smack *ssp = sk->sk_security;
1841 struct netlbl_lsm_secattr secattr;
1842 int rc = 0;
1843
1844 /*
1845 * Usually the netlabel code will handle changing the
1846 * packet labeling based on the label.
1847 * The case of a single label host is different, because
1848 * a single label host should never get a labeled packet
1849 * even though the label is usually associated with a packet
1850 * label.
1851 */
1852 local_bh_disable();
1853 bh_lock_sock_nested(sk);
1854
1855 if (ssp->smk_out == smack_net_ambient ||
1856 labeled == SMACK_UNLABELED_SOCKET)
1857 netlbl_sock_delattr(sk);
1858 else {
1859 netlbl_secattr_init(&secattr);
1860 smack_to_secattr(ssp->smk_out, &secattr);
1861 rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr);
1862 netlbl_secattr_destroy(&secattr);
1863 }
1864
1865 bh_unlock_sock(sk);
1866 local_bh_enable();
1867
1868 return rc;
1869}
1870
1871/**
1872 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1873 * @sk: the socket
1874 * @sap: the destination address
1875 *
1876 * Set the correct secattr for the given socket based on the destination
1877 * address and perform any outbound access checks needed.
1878 *
1879 * Returns 0 on success or an error code.
1880 *
1881 */
1882static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1883{
1884 int rc;
1885 int sk_lbl;
1886 char *hostsp;
1887 struct socket_smack *ssp = sk->sk_security;
1888 struct smk_audit_info ad;
1889
1890 rcu_read_lock();
1891 hostsp = smack_host_label(sap);
1892 if (hostsp != NULL) {
1893 sk_lbl = SMACK_UNLABELED_SOCKET;
1894#ifdef CONFIG_AUDIT
1895 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
1896 ad.a.u.net.family = sap->sin_family;
1897 ad.a.u.net.dport = sap->sin_port;
1898 ad.a.u.net.v4info.daddr = sap->sin_addr.s_addr;
1899#endif
1900 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1901 } else {
1902 sk_lbl = SMACK_CIPSO_SOCKET;
1903 rc = 0;
1904 }
1905 rcu_read_unlock();
1906 if (rc != 0)
1907 return rc;
1908
1909 return smack_netlabel(sk, sk_lbl);
1910}
1911
1912/**
1913 * smack_inode_setsecurity - set smack xattrs
1914 * @inode: the object
1915 * @name: attribute name
1916 * @value: attribute value
1917 * @size: size of the attribute
1918 * @flags: unused
1919 *
1920 * Sets the named attribute in the appropriate blob
1921 *
1922 * Returns 0 on success, or an error code
1923 */
1924static int smack_inode_setsecurity(struct inode *inode, const char *name,
1925 const void *value, size_t size, int flags)
1926{
1927 char *sp;
1928 struct inode_smack *nsp = inode->i_security;
1929 struct socket_smack *ssp;
1930 struct socket *sock;
1931 int rc = 0;
1932
1933 if (value == NULL || size > SMK_LABELLEN || size == 0)
1934 return -EACCES;
1935
1936 sp = smk_import(value, size);
1937 if (sp == NULL)
1938 return -EINVAL;
1939
1940 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1941 nsp->smk_inode = sp;
1942 nsp->smk_flags |= SMK_INODE_INSTANT;
1943 return 0;
1944 }
1945 /*
1946 * The rest of the Smack xattrs are only on sockets.
1947 */
1948 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1949 return -EOPNOTSUPP;
1950
1951 sock = SOCKET_I(inode);
1952 if (sock == NULL || sock->sk == NULL)
1953 return -EOPNOTSUPP;
1954
1955 ssp = sock->sk->sk_security;
1956
1957 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1958 ssp->smk_in = sp;
1959 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1960 ssp->smk_out = sp;
1961 if (sock->sk->sk_family != PF_UNIX) {
1962 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1963 if (rc != 0)
1964 printk(KERN_WARNING
1965 "Smack: \"%s\" netlbl error %d.\n",
1966 __func__, -rc);
1967 }
1968 } else
1969 return -EOPNOTSUPP;
1970
1971 return 0;
1972}
1973
1974/**
1975 * smack_socket_post_create - finish socket setup
1976 * @sock: the socket
1977 * @family: protocol family
1978 * @type: unused
1979 * @protocol: unused
1980 * @kern: unused
1981 *
1982 * Sets the netlabel information on the socket
1983 *
1984 * Returns 0 on success, and error code otherwise
1985 */
1986static int smack_socket_post_create(struct socket *sock, int family,
1987 int type, int protocol, int kern)
1988{
1989 if (family != PF_INET || sock->sk == NULL)
1990 return 0;
1991 /*
1992 * Set the outbound netlbl.
1993 */
1994 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1995}
1996
1997/**
1998 * smack_socket_connect - connect access check
1999 * @sock: the socket
2000 * @sap: the other end
2001 * @addrlen: size of sap
2002 *
2003 * Verifies that a connection may be possible
2004 *
2005 * Returns 0 on success, and error code otherwise
2006 */
2007static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2008 int addrlen)
2009{
2010 if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
2011 return 0;
2012 if (addrlen < sizeof(struct sockaddr_in))
2013 return -EINVAL;
2014
2015 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2016}
2017
2018/**
2019 * smack_flags_to_may - convert S_ to MAY_ values
2020 * @flags: the S_ value
2021 *
2022 * Returns the equivalent MAY_ value
2023 */
2024static int smack_flags_to_may(int flags)
2025{
2026 int may = 0;
2027
2028 if (flags & S_IRUGO)
2029 may |= MAY_READ;
2030 if (flags & S_IWUGO)
2031 may |= MAY_WRITE;
2032 if (flags & S_IXUGO)
2033 may |= MAY_EXEC;
2034
2035 return may;
2036}
2037
2038/**
2039 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2040 * @msg: the object
2041 *
2042 * Returns 0
2043 */
2044static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2045{
2046 msg->security = smk_of_current();
2047 return 0;
2048}
2049
2050/**
2051 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2052 * @msg: the object
2053 *
2054 * Clears the blob pointer
2055 */
2056static void smack_msg_msg_free_security(struct msg_msg *msg)
2057{
2058 msg->security = NULL;
2059}
2060
2061/**
2062 * smack_of_shm - the smack pointer for the shm
2063 * @shp: the object
2064 *
2065 * Returns a pointer to the smack value
2066 */
2067static char *smack_of_shm(struct shmid_kernel *shp)
2068{
2069 return (char *)shp->shm_perm.security;
2070}
2071
2072/**
2073 * smack_shm_alloc_security - Set the security blob for shm
2074 * @shp: the object
2075 *
2076 * Returns 0
2077 */
2078static int smack_shm_alloc_security(struct shmid_kernel *shp)
2079{
2080 struct kern_ipc_perm *isp = &shp->shm_perm;
2081
2082 isp->security = smk_of_current();
2083 return 0;
2084}
2085
2086/**
2087 * smack_shm_free_security - Clear the security blob for shm
2088 * @shp: the object
2089 *
2090 * Clears the blob pointer
2091 */
2092static void smack_shm_free_security(struct shmid_kernel *shp)
2093{
2094 struct kern_ipc_perm *isp = &shp->shm_perm;
2095
2096 isp->security = NULL;
2097}
2098
2099/**
2100 * smk_curacc_shm : check if current has access on shm
2101 * @shp : the object
2102 * @access : access requested
2103 *
2104 * Returns 0 if current has the requested access, error code otherwise
2105 */
2106static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2107{
2108 char *ssp = smack_of_shm(shp);
2109 struct smk_audit_info ad;
2110
2111#ifdef CONFIG_AUDIT
2112 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2113 ad.a.u.ipc_id = shp->shm_perm.id;
2114#endif
2115 return smk_curacc(ssp, access, &ad);
2116}
2117
2118/**
2119 * smack_shm_associate - Smack access check for shm
2120 * @shp: the object
2121 * @shmflg: access requested
2122 *
2123 * Returns 0 if current has the requested access, error code otherwise
2124 */
2125static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2126{
2127 int may;
2128
2129 may = smack_flags_to_may(shmflg);
2130 return smk_curacc_shm(shp, may);
2131}
2132
2133/**
2134 * smack_shm_shmctl - Smack access check for shm
2135 * @shp: the object
2136 * @cmd: what it wants to do
2137 *
2138 * Returns 0 if current has the requested access, error code otherwise
2139 */
2140static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2141{
2142 int may;
2143
2144 switch (cmd) {
2145 case IPC_STAT:
2146 case SHM_STAT:
2147 may = MAY_READ;
2148 break;
2149 case IPC_SET:
2150 case SHM_LOCK:
2151 case SHM_UNLOCK:
2152 case IPC_RMID:
2153 may = MAY_READWRITE;
2154 break;
2155 case IPC_INFO:
2156 case SHM_INFO:
2157 /*
2158 * System level information.
2159 */
2160 return 0;
2161 default:
2162 return -EINVAL;
2163 }
2164 return smk_curacc_shm(shp, may);
2165}
2166
2167/**
2168 * smack_shm_shmat - Smack access for shmat
2169 * @shp: the object
2170 * @shmaddr: unused
2171 * @shmflg: access requested
2172 *
2173 * Returns 0 if current has the requested access, error code otherwise
2174 */
2175static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2176 int shmflg)
2177{
2178 int may;
2179
2180 may = smack_flags_to_may(shmflg);
2181 return smk_curacc_shm(shp, may);
2182}
2183
2184/**
2185 * smack_of_sem - the smack pointer for the sem
2186 * @sma: the object
2187 *
2188 * Returns a pointer to the smack value
2189 */
2190static char *smack_of_sem(struct sem_array *sma)
2191{
2192 return (char *)sma->sem_perm.security;
2193}
2194
2195/**
2196 * smack_sem_alloc_security - Set the security blob for sem
2197 * @sma: the object
2198 *
2199 * Returns 0
2200 */
2201static int smack_sem_alloc_security(struct sem_array *sma)
2202{
2203 struct kern_ipc_perm *isp = &sma->sem_perm;
2204
2205 isp->security = smk_of_current();
2206 return 0;
2207}
2208
2209/**
2210 * smack_sem_free_security - Clear the security blob for sem
2211 * @sma: the object
2212 *
2213 * Clears the blob pointer
2214 */
2215static void smack_sem_free_security(struct sem_array *sma)
2216{
2217 struct kern_ipc_perm *isp = &sma->sem_perm;
2218
2219 isp->security = NULL;
2220}
2221
2222/**
2223 * smk_curacc_sem : check if current has access on sem
2224 * @sma : the object
2225 * @access : access requested
2226 *
2227 * Returns 0 if current has the requested access, error code otherwise
2228 */
2229static int smk_curacc_sem(struct sem_array *sma, int access)
2230{
2231 char *ssp = smack_of_sem(sma);
2232 struct smk_audit_info ad;
2233
2234#ifdef CONFIG_AUDIT
2235 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2236 ad.a.u.ipc_id = sma->sem_perm.id;
2237#endif
2238 return smk_curacc(ssp, access, &ad);
2239}
2240
2241/**
2242 * smack_sem_associate - Smack access check for sem
2243 * @sma: the object
2244 * @semflg: access requested
2245 *
2246 * Returns 0 if current has the requested access, error code otherwise
2247 */
2248static int smack_sem_associate(struct sem_array *sma, int semflg)
2249{
2250 int may;
2251
2252 may = smack_flags_to_may(semflg);
2253 return smk_curacc_sem(sma, may);
2254}
2255
2256/**
2257 * smack_sem_shmctl - Smack access check for sem
2258 * @sma: the object
2259 * @cmd: what it wants to do
2260 *
2261 * Returns 0 if current has the requested access, error code otherwise
2262 */
2263static int smack_sem_semctl(struct sem_array *sma, int cmd)
2264{
2265 int may;
2266
2267 switch (cmd) {
2268 case GETPID:
2269 case GETNCNT:
2270 case GETZCNT:
2271 case GETVAL:
2272 case GETALL:
2273 case IPC_STAT:
2274 case SEM_STAT:
2275 may = MAY_READ;
2276 break;
2277 case SETVAL:
2278 case SETALL:
2279 case IPC_RMID:
2280 case IPC_SET:
2281 may = MAY_READWRITE;
2282 break;
2283 case IPC_INFO:
2284 case SEM_INFO:
2285 /*
2286 * System level information
2287 */
2288 return 0;
2289 default:
2290 return -EINVAL;
2291 }
2292
2293 return smk_curacc_sem(sma, may);
2294}
2295
2296/**
2297 * smack_sem_semop - Smack checks of semaphore operations
2298 * @sma: the object
2299 * @sops: unused
2300 * @nsops: unused
2301 * @alter: unused
2302 *
2303 * Treated as read and write in all cases.
2304 *
2305 * Returns 0 if access is allowed, error code otherwise
2306 */
2307static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2308 unsigned nsops, int alter)
2309{
2310 return smk_curacc_sem(sma, MAY_READWRITE);
2311}
2312
2313/**
2314 * smack_msg_alloc_security - Set the security blob for msg
2315 * @msq: the object
2316 *
2317 * Returns 0
2318 */
2319static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2320{
2321 struct kern_ipc_perm *kisp = &msq->q_perm;
2322
2323 kisp->security = smk_of_current();
2324 return 0;
2325}
2326
2327/**
2328 * smack_msg_free_security - Clear the security blob for msg
2329 * @msq: the object
2330 *
2331 * Clears the blob pointer
2332 */
2333static void smack_msg_queue_free_security(struct msg_queue *msq)
2334{
2335 struct kern_ipc_perm *kisp = &msq->q_perm;
2336
2337 kisp->security = NULL;
2338}
2339
2340/**
2341 * smack_of_msq - the smack pointer for the msq
2342 * @msq: the object
2343 *
2344 * Returns a pointer to the smack value
2345 */
2346static char *smack_of_msq(struct msg_queue *msq)
2347{
2348 return (char *)msq->q_perm.security;
2349}
2350
2351/**
2352 * smk_curacc_msq : helper to check if current has access on msq
2353 * @msq : the msq
2354 * @access : access requested
2355 *
2356 * return 0 if current has access, error otherwise
2357 */
2358static int smk_curacc_msq(struct msg_queue *msq, int access)
2359{
2360 char *msp = smack_of_msq(msq);
2361 struct smk_audit_info ad;
2362
2363#ifdef CONFIG_AUDIT
2364 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2365 ad.a.u.ipc_id = msq->q_perm.id;
2366#endif
2367 return smk_curacc(msp, access, &ad);
2368}
2369
2370/**
2371 * smack_msg_queue_associate - Smack access check for msg_queue
2372 * @msq: the object
2373 * @msqflg: access requested
2374 *
2375 * Returns 0 if current has the requested access, error code otherwise
2376 */
2377static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2378{
2379 int may;
2380
2381 may = smack_flags_to_may(msqflg);
2382 return smk_curacc_msq(msq, may);
2383}
2384
2385/**
2386 * smack_msg_queue_msgctl - Smack access check for msg_queue
2387 * @msq: the object
2388 * @cmd: what it wants to do
2389 *
2390 * Returns 0 if current has the requested access, error code otherwise
2391 */
2392static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2393{
2394 int may;
2395
2396 switch (cmd) {
2397 case IPC_STAT:
2398 case MSG_STAT:
2399 may = MAY_READ;
2400 break;
2401 case IPC_SET:
2402 case IPC_RMID:
2403 may = MAY_READWRITE;
2404 break;
2405 case IPC_INFO:
2406 case MSG_INFO:
2407 /*
2408 * System level information
2409 */
2410 return 0;
2411 default:
2412 return -EINVAL;
2413 }
2414
2415 return smk_curacc_msq(msq, may);
2416}
2417
2418/**
2419 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2420 * @msq: the object
2421 * @msg: unused
2422 * @msqflg: access requested
2423 *
2424 * Returns 0 if current has the requested access, error code otherwise
2425 */
2426static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2427 int msqflg)
2428{
2429 int may;
2430
2431 may = smack_flags_to_may(msqflg);
2432 return smk_curacc_msq(msq, may);
2433}
2434
2435/**
2436 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2437 * @msq: the object
2438 * @msg: unused
2439 * @target: unused
2440 * @type: unused
2441 * @mode: unused
2442 *
2443 * Returns 0 if current has read and write access, error code otherwise
2444 */
2445static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2446 struct task_struct *target, long type, int mode)
2447{
2448 return smk_curacc_msq(msq, MAY_READWRITE);
2449}
2450
2451/**
2452 * smack_ipc_permission - Smack access for ipc_permission()
2453 * @ipp: the object permissions
2454 * @flag: access requested
2455 *
2456 * Returns 0 if current has read and write access, error code otherwise
2457 */
2458static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2459{
2460 char *isp = ipp->security;
2461 int may = smack_flags_to_may(flag);
2462 struct smk_audit_info ad;
2463
2464#ifdef CONFIG_AUDIT
2465 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2466 ad.a.u.ipc_id = ipp->id;
2467#endif
2468 return smk_curacc(isp, may, &ad);
2469}
2470
2471/**
2472 * smack_ipc_getsecid - Extract smack security id
2473 * @ipp: the object permissions
2474 * @secid: where result will be saved
2475 */
2476static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2477{
2478 char *smack = ipp->security;
2479
2480 *secid = smack_to_secid(smack);
2481}
2482
2483/**
2484 * smack_d_instantiate - Make sure the blob is correct on an inode
2485 * @opt_dentry: dentry where inode will be attached
2486 * @inode: the object
2487 *
2488 * Set the inode's security blob if it hasn't been done already.
2489 */
2490static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2491{
2492 struct super_block *sbp;
2493 struct superblock_smack *sbsp;
2494 struct inode_smack *isp;
2495 char *csp = smk_of_current();
2496 char *fetched;
2497 char *final;
2498 char trattr[TRANS_TRUE_SIZE];
2499 int transflag = 0;
2500 struct dentry *dp;
2501
2502 if (inode == NULL)
2503 return;
2504
2505 isp = inode->i_security;
2506
2507 mutex_lock(&isp->smk_lock);
2508 /*
2509 * If the inode is already instantiated
2510 * take the quick way out
2511 */
2512 if (isp->smk_flags & SMK_INODE_INSTANT)
2513 goto unlockandout;
2514
2515 sbp = inode->i_sb;
2516 sbsp = sbp->s_security;
2517 /*
2518 * We're going to use the superblock default label
2519 * if there's no label on the file.
2520 */
2521 final = sbsp->smk_default;
2522
2523 /*
2524 * If this is the root inode the superblock
2525 * may be in the process of initialization.
2526 * If that is the case use the root value out
2527 * of the superblock.
2528 */
2529 if (opt_dentry->d_parent == opt_dentry) {
2530 isp->smk_inode = sbsp->smk_root;
2531 isp->smk_flags |= SMK_INODE_INSTANT;
2532 goto unlockandout;
2533 }
2534
2535 /*
2536 * This is pretty hackish.
2537 * Casey says that we shouldn't have to do
2538 * file system specific code, but it does help
2539 * with keeping it simple.
2540 */
2541 switch (sbp->s_magic) {
2542 case SMACK_MAGIC:
2543 /*
2544 * Casey says that it's a little embarrassing
2545 * that the smack file system doesn't do
2546 * extended attributes.
2547 */
2548 final = smack_known_star.smk_known;
2549 break;
2550 case PIPEFS_MAGIC:
2551 /*
2552 * Casey says pipes are easy (?)
2553 */
2554 final = smack_known_star.smk_known;
2555 break;
2556 case DEVPTS_SUPER_MAGIC:
2557 /*
2558 * devpts seems content with the label of the task.
2559 * Programs that change smack have to treat the
2560 * pty with respect.
2561 */
2562 final = csp;
2563 break;
2564 case SOCKFS_MAGIC:
2565 /*
2566 * Socket access is controlled by the socket
2567 * structures associated with the task involved.
2568 */
2569 final = smack_known_star.smk_known;
2570 break;
2571 case PROC_SUPER_MAGIC:
2572 /*
2573 * Casey says procfs appears not to care.
2574 * The superblock default suffices.
2575 */
2576 break;
2577 case TMPFS_MAGIC:
2578 /*
2579 * Device labels should come from the filesystem,
2580 * but watch out, because they're volitile,
2581 * getting recreated on every reboot.
2582 */
2583 final = smack_known_star.smk_known;
2584 /*
2585 * No break.
2586 *
2587 * If a smack value has been set we want to use it,
2588 * but since tmpfs isn't giving us the opportunity
2589 * to set mount options simulate setting the
2590 * superblock default.
2591 */
2592 default:
2593 /*
2594 * This isn't an understood special case.
2595 * Get the value from the xattr.
2596 */
2597
2598 /*
2599 * UNIX domain sockets use lower level socket data.
2600 */
2601 if (S_ISSOCK(inode->i_mode)) {
2602 final = smack_known_star.smk_known;
2603 break;
2604 }
2605 /*
2606 * No xattr support means, alas, no SMACK label.
2607 * Use the aforeapplied default.
2608 * It would be curious if the label of the task
2609 * does not match that assigned.
2610 */
2611 if (inode->i_op->getxattr == NULL)
2612 break;
2613 /*
2614 * Get the dentry for xattr.
2615 */
2616 dp = dget(opt_dentry);
2617 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2618 if (fetched != NULL) {
2619 final = fetched;
2620 if (S_ISDIR(inode->i_mode)) {
2621 trattr[0] = '\0';
2622 inode->i_op->getxattr(dp,
2623 XATTR_NAME_SMACKTRANSMUTE,
2624 trattr, TRANS_TRUE_SIZE);
2625 if (strncmp(trattr, TRANS_TRUE,
2626 TRANS_TRUE_SIZE) == 0)
2627 transflag = SMK_INODE_TRANSMUTE;
2628 }
2629 }
2630 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2631 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2632
2633 dput(dp);
2634 break;
2635 }
2636
2637 if (final == NULL)
2638 isp->smk_inode = csp;
2639 else
2640 isp->smk_inode = final;
2641
2642 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2643
2644unlockandout:
2645 mutex_unlock(&isp->smk_lock);
2646 return;
2647}
2648
2649/**
2650 * smack_getprocattr - Smack process attribute access
2651 * @p: the object task
2652 * @name: the name of the attribute in /proc/.../attr
2653 * @value: where to put the result
2654 *
2655 * Places a copy of the task Smack into value
2656 *
2657 * Returns the length of the smack label or an error code
2658 */
2659static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2660{
2661 char *cp;
2662 int slen;
2663
2664 if (strcmp(name, "current") != 0)
2665 return -EINVAL;
2666
2667 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2668 if (cp == NULL)
2669 return -ENOMEM;
2670
2671 slen = strlen(cp);
2672 *value = cp;
2673 return slen;
2674}
2675
2676/**
2677 * smack_setprocattr - Smack process attribute setting
2678 * @p: the object task
2679 * @name: the name of the attribute in /proc/.../attr
2680 * @value: the value to set
2681 * @size: the size of the value
2682 *
2683 * Sets the Smack value of the task. Only setting self
2684 * is permitted and only with privilege
2685 *
2686 * Returns the length of the smack label or an error code
2687 */
2688static int smack_setprocattr(struct task_struct *p, char *name,
2689 void *value, size_t size)
2690{
2691 int rc;
2692 struct task_smack *tsp;
2693 struct task_smack *oldtsp;
2694 struct cred *new;
2695 char *newsmack;
2696
2697 /*
2698 * Changing another process' Smack value is too dangerous
2699 * and supports no sane use case.
2700 */
2701 if (p != current)
2702 return -EPERM;
2703
2704 if (!capable(CAP_MAC_ADMIN))
2705 return -EPERM;
2706
2707 if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2708 return -EINVAL;
2709
2710 if (strcmp(name, "current") != 0)
2711 return -EINVAL;
2712
2713 newsmack = smk_import(value, size);
2714 if (newsmack == NULL)
2715 return -EINVAL;
2716
2717 /*
2718 * No process is ever allowed the web ("@") label.
2719 */
2720 if (newsmack == smack_known_web.smk_known)
2721 return -EPERM;
2722
2723 oldtsp = p->cred->security;
2724 new = prepare_creds();
2725 if (new == NULL)
2726 return -ENOMEM;
2727
2728 tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
2729 if (tsp == NULL) {
2730 kfree(new);
2731 return -ENOMEM;
2732 }
2733 rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
2734 if (rc != 0)
2735 return rc;
2736
2737 new->security = tsp;
2738 commit_creds(new);
2739 return size;
2740}
2741
2742/**
2743 * smack_unix_stream_connect - Smack access on UDS
2744 * @sock: one sock
2745 * @other: the other sock
2746 * @newsk: unused
2747 *
2748 * Return 0 if a subject with the smack of sock could access
2749 * an object with the smack of other, otherwise an error code
2750 */
2751static int smack_unix_stream_connect(struct sock *sock,
2752 struct sock *other, struct sock *newsk)
2753{
2754 struct socket_smack *ssp = sock->sk_security;
2755 struct socket_smack *osp = other->sk_security;
2756 struct smk_audit_info ad;
2757 int rc = 0;
2758
2759 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2760 smk_ad_setfield_u_net_sk(&ad, other);
2761
2762 if (!capable(CAP_MAC_OVERRIDE))
2763 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2764
2765 return rc;
2766}
2767
2768/**
2769 * smack_unix_may_send - Smack access on UDS
2770 * @sock: one socket
2771 * @other: the other socket
2772 *
2773 * Return 0 if a subject with the smack of sock could access
2774 * an object with the smack of other, otherwise an error code
2775 */
2776static int smack_unix_may_send(struct socket *sock, struct socket *other)
2777{
2778 struct socket_smack *ssp = sock->sk->sk_security;
2779 struct socket_smack *osp = other->sk->sk_security;
2780 struct smk_audit_info ad;
2781 int rc = 0;
2782
2783 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2784 smk_ad_setfield_u_net_sk(&ad, other->sk);
2785
2786 if (!capable(CAP_MAC_OVERRIDE))
2787 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2788
2789 return rc;
2790}
2791
2792/**
2793 * smack_socket_sendmsg - Smack check based on destination host
2794 * @sock: the socket
2795 * @msg: the message
2796 * @size: the size of the message
2797 *
2798 * Return 0 if the current subject can write to the destination
2799 * host. This is only a question if the destination is a single
2800 * label host.
2801 */
2802static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2803 int size)
2804{
2805 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2806
2807 /*
2808 * Perfectly reasonable for this to be NULL
2809 */
2810 if (sip == NULL || sip->sin_family != AF_INET)
2811 return 0;
2812
2813 return smack_netlabel_send(sock->sk, sip);
2814}
2815
2816
2817/**
2818 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2819 * @sap: netlabel secattr
2820 * @sip: where to put the result
2821 *
2822 * Copies a smack label into sip
2823 */
2824static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2825{
2826 char smack[SMK_LABELLEN];
2827 char *sp;
2828 int pcat;
2829
2830 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2831 /*
2832 * Looks like a CIPSO packet.
2833 * If there are flags but no level netlabel isn't
2834 * behaving the way we expect it to.
2835 *
2836 * Get the categories, if any
2837 * Without guidance regarding the smack value
2838 * for the packet fall back on the network
2839 * ambient value.
2840 */
2841 memset(smack, '\0', SMK_LABELLEN);
2842 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2843 for (pcat = -1;;) {
2844 pcat = netlbl_secattr_catmap_walk(
2845 sap->attr.mls.cat, pcat + 1);
2846 if (pcat < 0)
2847 break;
2848 smack_catset_bit(pcat, smack);
2849 }
2850 /*
2851 * If it is CIPSO using smack direct mapping
2852 * we are already done. WeeHee.
2853 */
2854 if (sap->attr.mls.lvl == smack_cipso_direct) {
2855 memcpy(sip, smack, SMK_MAXLEN);
2856 return;
2857 }
2858 /*
2859 * Look it up in the supplied table if it is not
2860 * a direct mapping.
2861 */
2862 smack_from_cipso(sap->attr.mls.lvl, smack, sip);
2863 return;
2864 }
2865 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2866 /*
2867 * Looks like a fallback, which gives us a secid.
2868 */
2869 sp = smack_from_secid(sap->attr.secid);
2870 /*
2871 * This has got to be a bug because it is
2872 * impossible to specify a fallback without
2873 * specifying the label, which will ensure
2874 * it has a secid, and the only way to get a
2875 * secid is from a fallback.
2876 */
2877 BUG_ON(sp == NULL);
2878 strncpy(sip, sp, SMK_MAXLEN);
2879 return;
2880 }
2881 /*
2882 * Without guidance regarding the smack value
2883 * for the packet fall back on the network
2884 * ambient value.
2885 */
2886 strncpy(sip, smack_net_ambient, SMK_MAXLEN);
2887 return;
2888}
2889
2890/**
2891 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2892 * @sk: socket
2893 * @skb: packet
2894 *
2895 * Returns 0 if the packet should be delivered, an error code otherwise
2896 */
2897static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2898{
2899 struct netlbl_lsm_secattr secattr;
2900 struct socket_smack *ssp = sk->sk_security;
2901 char smack[SMK_LABELLEN];
2902 char *csp;
2903 int rc;
2904 struct smk_audit_info ad;
2905 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2906 return 0;
2907
2908 /*
2909 * Translate what netlabel gave us.
2910 */
2911 netlbl_secattr_init(&secattr);
2912
2913 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2914 if (rc == 0) {
2915 smack_from_secattr(&secattr, smack);
2916 csp = smack;
2917 } else
2918 csp = smack_net_ambient;
2919
2920 netlbl_secattr_destroy(&secattr);
2921
2922#ifdef CONFIG_AUDIT
2923 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2924 ad.a.u.net.family = sk->sk_family;
2925 ad.a.u.net.netif = skb->skb_iif;
2926 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2927#endif
2928 /*
2929 * Receiving a packet requires that the other end
2930 * be able to write here. Read access is not required.
2931 * This is the simplist possible security model
2932 * for networking.
2933 */
2934 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2935 if (rc != 0)
2936 netlbl_skbuff_err(skb, rc, 0);
2937 return rc;
2938}
2939
2940/**
2941 * smack_socket_getpeersec_stream - pull in packet label
2942 * @sock: the socket
2943 * @optval: user's destination
2944 * @optlen: size thereof
2945 * @len: max thereof
2946 *
2947 * returns zero on success, an error code otherwise
2948 */
2949static int smack_socket_getpeersec_stream(struct socket *sock,
2950 char __user *optval,
2951 int __user *optlen, unsigned len)
2952{
2953 struct socket_smack *ssp;
2954 int slen;
2955 int rc = 0;
2956
2957 ssp = sock->sk->sk_security;
2958 slen = strlen(ssp->smk_packet) + 1;
2959
2960 if (slen > len)
2961 rc = -ERANGE;
2962 else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2963 rc = -EFAULT;
2964
2965 if (put_user(slen, optlen) != 0)
2966 rc = -EFAULT;
2967
2968 return rc;
2969}
2970
2971
2972/**
2973 * smack_socket_getpeersec_dgram - pull in packet label
2974 * @sock: the peer socket
2975 * @skb: packet data
2976 * @secid: pointer to where to put the secid of the packet
2977 *
2978 * Sets the netlabel socket state on sk from parent
2979 */
2980static int smack_socket_getpeersec_dgram(struct socket *sock,
2981 struct sk_buff *skb, u32 *secid)
2982
2983{
2984 struct netlbl_lsm_secattr secattr;
2985 struct socket_smack *sp;
2986 char smack[SMK_LABELLEN];
2987 int family = PF_UNSPEC;
2988 u32 s = 0; /* 0 is the invalid secid */
2989 int rc;
2990
2991 if (skb != NULL) {
2992 if (skb->protocol == htons(ETH_P_IP))
2993 family = PF_INET;
2994 else if (skb->protocol == htons(ETH_P_IPV6))
2995 family = PF_INET6;
2996 }
2997 if (family == PF_UNSPEC && sock != NULL)
2998 family = sock->sk->sk_family;
2999
3000 if (family == PF_UNIX) {
3001 sp = sock->sk->sk_security;
3002 s = smack_to_secid(sp->smk_out);
3003 } else if (family == PF_INET || family == PF_INET6) {
3004 /*
3005 * Translate what netlabel gave us.
3006 */
3007 netlbl_secattr_init(&secattr);
3008 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3009 if (rc == 0) {
3010 smack_from_secattr(&secattr, smack);
3011 s = smack_to_secid(smack);
3012 }
3013 netlbl_secattr_destroy(&secattr);
3014 }
3015 *secid = s;
3016 if (s == 0)
3017 return -EINVAL;
3018 return 0;
3019}
3020
3021/**
3022 * smack_sock_graft - Initialize a newly created socket with an existing sock
3023 * @sk: child sock
3024 * @parent: parent socket
3025 *
3026 * Set the smk_{in,out} state of an existing sock based on the process that
3027 * is creating the new socket.
3028 */
3029static void smack_sock_graft(struct sock *sk, struct socket *parent)
3030{
3031 struct socket_smack *ssp;
3032
3033 if (sk == NULL ||
3034 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3035 return;
3036
3037 ssp = sk->sk_security;
3038 ssp->smk_in = ssp->smk_out = smk_of_current();
3039 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3040}
3041
3042/**
3043 * smack_inet_conn_request - Smack access check on connect
3044 * @sk: socket involved
3045 * @skb: packet
3046 * @req: unused
3047 *
3048 * Returns 0 if a task with the packet label could write to
3049 * the socket, otherwise an error code
3050 */
3051static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3052 struct request_sock *req)
3053{
3054 u16 family = sk->sk_family;
3055 struct socket_smack *ssp = sk->sk_security;
3056 struct netlbl_lsm_secattr secattr;
3057 struct sockaddr_in addr;
3058 struct iphdr *hdr;
3059 char smack[SMK_LABELLEN];
3060 int rc;
3061 struct smk_audit_info ad;
3062
3063 /* handle mapped IPv4 packets arriving via IPv6 sockets */
3064 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3065 family = PF_INET;
3066
3067 netlbl_secattr_init(&secattr);
3068 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3069 if (rc == 0)
3070 smack_from_secattr(&secattr, smack);
3071 else
3072 strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
3073 netlbl_secattr_destroy(&secattr);
3074
3075#ifdef CONFIG_AUDIT
3076 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
3077 ad.a.u.net.family = family;
3078 ad.a.u.net.netif = skb->skb_iif;
3079 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3080#endif
3081 /*
3082 * Receiving a packet requires that the other end be able to write
3083 * here. Read access is not required.
3084 */
3085 rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
3086 if (rc != 0)
3087 return rc;
3088
3089 /*
3090 * Save the peer's label in the request_sock so we can later setup
3091 * smk_packet in the child socket so that SO_PEERCRED can report it.
3092 */
3093 req->peer_secid = smack_to_secid(smack);
3094
3095 /*
3096 * We need to decide if we want to label the incoming connection here
3097 * if we do we only need to label the request_sock and the stack will
3098 * propagate the wire-label to the sock when it is created.
3099 */
3100 hdr = ip_hdr(skb);
3101 addr.sin_addr.s_addr = hdr->saddr;
3102 rcu_read_lock();
3103 if (smack_host_label(&addr) == NULL) {
3104 rcu_read_unlock();
3105 netlbl_secattr_init(&secattr);
3106 smack_to_secattr(smack, &secattr);
3107 rc = netlbl_req_setattr(req, &secattr);
3108 netlbl_secattr_destroy(&secattr);
3109 } else {
3110 rcu_read_unlock();
3111 netlbl_req_delattr(req);
3112 }
3113
3114 return rc;
3115}
3116
3117/**
3118 * smack_inet_csk_clone - Copy the connection information to the new socket
3119 * @sk: the new socket
3120 * @req: the connection's request_sock
3121 *
3122 * Transfer the connection's peer label to the newly created socket.
3123 */
3124static void smack_inet_csk_clone(struct sock *sk,
3125 const struct request_sock *req)
3126{
3127 struct socket_smack *ssp = sk->sk_security;
3128 char *smack;
3129
3130 if (req->peer_secid != 0) {
3131 smack = smack_from_secid(req->peer_secid);
3132 strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
3133 } else
3134 ssp->smk_packet[0] = '\0';
3135}
3136
3137/*
3138 * Key management security hooks
3139 *
3140 * Casey has not tested key support very heavily.
3141 * The permission check is most likely too restrictive.
3142 * If you care about keys please have a look.
3143 */
3144#ifdef CONFIG_KEYS
3145
3146/**
3147 * smack_key_alloc - Set the key security blob
3148 * @key: object
3149 * @cred: the credentials to use
3150 * @flags: unused
3151 *
3152 * No allocation required
3153 *
3154 * Returns 0
3155 */
3156static int smack_key_alloc(struct key *key, const struct cred *cred,
3157 unsigned long flags)
3158{
3159 key->security = smk_of_task(cred->security);
3160 return 0;
3161}
3162
3163/**
3164 * smack_key_free - Clear the key security blob
3165 * @key: the object
3166 *
3167 * Clear the blob pointer
3168 */
3169static void smack_key_free(struct key *key)
3170{
3171 key->security = NULL;
3172}
3173
3174/*
3175 * smack_key_permission - Smack access on a key
3176 * @key_ref: gets to the object
3177 * @cred: the credentials to use
3178 * @perm: unused
3179 *
3180 * Return 0 if the task has read and write to the object,
3181 * an error code otherwise
3182 */
3183static int smack_key_permission(key_ref_t key_ref,
3184 const struct cred *cred, key_perm_t perm)
3185{
3186 struct key *keyp;
3187 struct smk_audit_info ad;
3188 char *tsp = smk_of_task(cred->security);
3189
3190 keyp = key_ref_to_ptr(key_ref);
3191 if (keyp == NULL)
3192 return -EINVAL;
3193 /*
3194 * If the key hasn't been initialized give it access so that
3195 * it may do so.
3196 */
3197 if (keyp->security == NULL)
3198 return 0;
3199 /*
3200 * This should not occur
3201 */
3202 if (tsp == NULL)
3203 return -EACCES;
3204#ifdef CONFIG_AUDIT
3205 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3206 ad.a.u.key_struct.key = keyp->serial;
3207 ad.a.u.key_struct.key_desc = keyp->description;
3208#endif
3209 return smk_access(tsp, keyp->security,
3210 MAY_READWRITE, &ad);
3211}
3212#endif /* CONFIG_KEYS */
3213
3214/*
3215 * Smack Audit hooks
3216 *
3217 * Audit requires a unique representation of each Smack specific
3218 * rule. This unique representation is used to distinguish the
3219 * object to be audited from remaining kernel objects and also
3220 * works as a glue between the audit hooks.
3221 *
3222 * Since repository entries are added but never deleted, we'll use
3223 * the smack_known label address related to the given audit rule as
3224 * the needed unique representation. This also better fits the smack
3225 * model where nearly everything is a label.
3226 */
3227#ifdef CONFIG_AUDIT
3228
3229/**
3230 * smack_audit_rule_init - Initialize a smack audit rule
3231 * @field: audit rule fields given from user-space (audit.h)
3232 * @op: required testing operator (=, !=, >, <, ...)
3233 * @rulestr: smack label to be audited
3234 * @vrule: pointer to save our own audit rule representation
3235 *
3236 * Prepare to audit cases where (@field @op @rulestr) is true.
3237 * The label to be audited is created if necessay.
3238 */
3239static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3240{
3241 char **rule = (char **)vrule;
3242 *rule = NULL;
3243
3244 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3245 return -EINVAL;
3246
3247 if (op != Audit_equal && op != Audit_not_equal)
3248 return -EINVAL;
3249
3250 *rule = smk_import(rulestr, 0);
3251
3252 return 0;
3253}
3254
3255/**
3256 * smack_audit_rule_known - Distinguish Smack audit rules
3257 * @krule: rule of interest, in Audit kernel representation format
3258 *
3259 * This is used to filter Smack rules from remaining Audit ones.
3260 * If it's proved that this rule belongs to us, the
3261 * audit_rule_match hook will be called to do the final judgement.
3262 */
3263static int smack_audit_rule_known(struct audit_krule *krule)
3264{
3265 struct audit_field *f;
3266 int i;
3267
3268 for (i = 0; i < krule->field_count; i++) {
3269 f = &krule->fields[i];
3270
3271 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3272 return 1;
3273 }
3274
3275 return 0;
3276}
3277
3278/**
3279 * smack_audit_rule_match - Audit given object ?
3280 * @secid: security id for identifying the object to test
3281 * @field: audit rule flags given from user-space
3282 * @op: required testing operator
3283 * @vrule: smack internal rule presentation
3284 * @actx: audit context associated with the check
3285 *
3286 * The core Audit hook. It's used to take the decision of
3287 * whether to audit or not to audit a given object.
3288 */
3289static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3290 struct audit_context *actx)
3291{
3292 char *smack;
3293 char *rule = vrule;
3294
3295 if (!rule) {
3296 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
3297 "Smack: missing rule\n");
3298 return -ENOENT;
3299 }
3300
3301 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3302 return 0;
3303
3304 smack = smack_from_secid(secid);
3305
3306 /*
3307 * No need to do string comparisons. If a match occurs,
3308 * both pointers will point to the same smack_known
3309 * label.
3310 */
3311 if (op == Audit_equal)
3312 return (rule == smack);
3313 if (op == Audit_not_equal)
3314 return (rule != smack);
3315
3316 return 0;
3317}
3318
3319/**
3320 * smack_audit_rule_free - free smack rule representation
3321 * @vrule: rule to be freed.
3322 *
3323 * No memory was allocated.
3324 */
3325static void smack_audit_rule_free(void *vrule)
3326{
3327 /* No-op */
3328}
3329
3330#endif /* CONFIG_AUDIT */
3331
3332/**
3333 * smack_secid_to_secctx - return the smack label for a secid
3334 * @secid: incoming integer
3335 * @secdata: destination
3336 * @seclen: how long it is
3337 *
3338 * Exists for networking code.
3339 */
3340static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3341{
3342 char *sp = smack_from_secid(secid);
3343
3344 if (secdata)
3345 *secdata = sp;
3346 *seclen = strlen(sp);
3347 return 0;
3348}
3349
3350/**
3351 * smack_secctx_to_secid - return the secid for a smack label
3352 * @secdata: smack label
3353 * @seclen: how long result is
3354 * @secid: outgoing integer
3355 *
3356 * Exists for audit and networking code.
3357 */
3358static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3359{
3360 *secid = smack_to_secid(secdata);
3361 return 0;
3362}
3363
3364/**
3365 * smack_release_secctx - don't do anything.
3366 * @secdata: unused
3367 * @seclen: unused
3368 *
3369 * Exists to make sure nothing gets done, and properly
3370 */
3371static void smack_release_secctx(char *secdata, u32 seclen)
3372{
3373}
3374
3375static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3376{
3377 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3378}
3379
3380static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3381{
3382 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3383}
3384
3385static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3386{
3387 int len = 0;
3388 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3389
3390 if (len < 0)
3391 return len;
3392 *ctxlen = len;
3393 return 0;
3394}
3395
3396struct security_operations smack_ops = {
3397 .name = "smack",
3398
3399 .ptrace_access_check = smack_ptrace_access_check,
3400 .ptrace_traceme = smack_ptrace_traceme,
3401 .syslog = smack_syslog,
3402
3403 .sb_alloc_security = smack_sb_alloc_security,
3404 .sb_free_security = smack_sb_free_security,
3405 .sb_copy_data = smack_sb_copy_data,
3406 .sb_kern_mount = smack_sb_kern_mount,
3407 .sb_statfs = smack_sb_statfs,
3408 .sb_mount = smack_sb_mount,
3409 .sb_umount = smack_sb_umount,
3410
3411 .bprm_set_creds = smack_bprm_set_creds,
3412
3413 .inode_alloc_security = smack_inode_alloc_security,
3414 .inode_free_security = smack_inode_free_security,
3415 .inode_init_security = smack_inode_init_security,
3416 .inode_link = smack_inode_link,
3417 .inode_unlink = smack_inode_unlink,
3418 .inode_rmdir = smack_inode_rmdir,
3419 .inode_rename = smack_inode_rename,
3420 .inode_permission = smack_inode_permission,
3421 .inode_setattr = smack_inode_setattr,
3422 .inode_getattr = smack_inode_getattr,
3423 .inode_setxattr = smack_inode_setxattr,
3424 .inode_post_setxattr = smack_inode_post_setxattr,
3425 .inode_getxattr = smack_inode_getxattr,
3426 .inode_removexattr = smack_inode_removexattr,
3427 .inode_getsecurity = smack_inode_getsecurity,
3428 .inode_setsecurity = smack_inode_setsecurity,
3429 .inode_listsecurity = smack_inode_listsecurity,
3430 .inode_getsecid = smack_inode_getsecid,
3431
3432 .file_permission = smack_file_permission,
3433 .file_alloc_security = smack_file_alloc_security,
3434 .file_free_security = smack_file_free_security,
3435 .file_ioctl = smack_file_ioctl,
3436 .file_lock = smack_file_lock,
3437 .file_fcntl = smack_file_fcntl,
3438 .file_mmap = smack_file_mmap,
3439 .file_set_fowner = smack_file_set_fowner,
3440 .file_send_sigiotask = smack_file_send_sigiotask,
3441 .file_receive = smack_file_receive,
3442
3443 .cred_alloc_blank = smack_cred_alloc_blank,
3444 .cred_free = smack_cred_free,
3445 .cred_prepare = smack_cred_prepare,
3446 .cred_transfer = smack_cred_transfer,
3447 .kernel_act_as = smack_kernel_act_as,
3448 .kernel_create_files_as = smack_kernel_create_files_as,
3449 .task_setpgid = smack_task_setpgid,
3450 .task_getpgid = smack_task_getpgid,
3451 .task_getsid = smack_task_getsid,
3452 .task_getsecid = smack_task_getsecid,
3453 .task_setnice = smack_task_setnice,
3454 .task_setioprio = smack_task_setioprio,
3455 .task_getioprio = smack_task_getioprio,
3456 .task_setscheduler = smack_task_setscheduler,
3457 .task_getscheduler = smack_task_getscheduler,
3458 .task_movememory = smack_task_movememory,
3459 .task_kill = smack_task_kill,
3460 .task_wait = smack_task_wait,
3461 .task_to_inode = smack_task_to_inode,
3462
3463 .ipc_permission = smack_ipc_permission,
3464 .ipc_getsecid = smack_ipc_getsecid,
3465
3466 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
3467 .msg_msg_free_security = smack_msg_msg_free_security,
3468
3469 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
3470 .msg_queue_free_security = smack_msg_queue_free_security,
3471 .msg_queue_associate = smack_msg_queue_associate,
3472 .msg_queue_msgctl = smack_msg_queue_msgctl,
3473 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
3474 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
3475
3476 .shm_alloc_security = smack_shm_alloc_security,
3477 .shm_free_security = smack_shm_free_security,
3478 .shm_associate = smack_shm_associate,
3479 .shm_shmctl = smack_shm_shmctl,
3480 .shm_shmat = smack_shm_shmat,
3481
3482 .sem_alloc_security = smack_sem_alloc_security,
3483 .sem_free_security = smack_sem_free_security,
3484 .sem_associate = smack_sem_associate,
3485 .sem_semctl = smack_sem_semctl,
3486 .sem_semop = smack_sem_semop,
3487
3488 .d_instantiate = smack_d_instantiate,
3489
3490 .getprocattr = smack_getprocattr,
3491 .setprocattr = smack_setprocattr,
3492
3493 .unix_stream_connect = smack_unix_stream_connect,
3494 .unix_may_send = smack_unix_may_send,
3495
3496 .socket_post_create = smack_socket_post_create,
3497 .socket_connect = smack_socket_connect,
3498 .socket_sendmsg = smack_socket_sendmsg,
3499 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
3500 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
3501 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
3502 .sk_alloc_security = smack_sk_alloc_security,
3503 .sk_free_security = smack_sk_free_security,
3504 .sock_graft = smack_sock_graft,
3505 .inet_conn_request = smack_inet_conn_request,
3506 .inet_csk_clone = smack_inet_csk_clone,
3507
3508 /* key management security hooks */
3509#ifdef CONFIG_KEYS
3510 .key_alloc = smack_key_alloc,
3511 .key_free = smack_key_free,
3512 .key_permission = smack_key_permission,
3513#endif /* CONFIG_KEYS */
3514
3515 /* Audit hooks */
3516#ifdef CONFIG_AUDIT
3517 .audit_rule_init = smack_audit_rule_init,
3518 .audit_rule_known = smack_audit_rule_known,
3519 .audit_rule_match = smack_audit_rule_match,
3520 .audit_rule_free = smack_audit_rule_free,
3521#endif /* CONFIG_AUDIT */
3522
3523 .secid_to_secctx = smack_secid_to_secctx,
3524 .secctx_to_secid = smack_secctx_to_secid,
3525 .release_secctx = smack_release_secctx,
3526 .inode_notifysecctx = smack_inode_notifysecctx,
3527 .inode_setsecctx = smack_inode_setsecctx,
3528 .inode_getsecctx = smack_inode_getsecctx,
3529};
3530
3531
3532static __init void init_smack_know_list(void)
3533{
3534 list_add(&smack_known_huh.list, &smack_known_list);
3535 list_add(&smack_known_hat.list, &smack_known_list);
3536 list_add(&smack_known_star.list, &smack_known_list);
3537 list_add(&smack_known_floor.list, &smack_known_list);
3538 list_add(&smack_known_invalid.list, &smack_known_list);
3539 list_add(&smack_known_web.list, &smack_known_list);
3540}
3541
3542/**
3543 * smack_init - initialize the smack system
3544 *
3545 * Returns 0
3546 */
3547static __init int smack_init(void)
3548{
3549 struct cred *cred;
3550 struct task_smack *tsp;
3551
3552 if (!security_module_enable(&smack_ops))
3553 return 0;
3554
3555 tsp = new_task_smack(smack_known_floor.smk_known,
3556 smack_known_floor.smk_known, GFP_KERNEL);
3557 if (tsp == NULL)
3558 return -ENOMEM;
3559
3560 printk(KERN_INFO "Smack: Initializing.\n");
3561
3562 /*
3563 * Set the security state for the initial task.
3564 */
3565 cred = (struct cred *) current->cred;
3566 cred->security = tsp;
3567
3568 /* initialize the smack_know_list */
3569 init_smack_know_list();
3570 /*
3571 * Initialize locks
3572 */
3573 spin_lock_init(&smack_known_huh.smk_cipsolock);
3574 spin_lock_init(&smack_known_hat.smk_cipsolock);
3575 spin_lock_init(&smack_known_star.smk_cipsolock);
3576 spin_lock_init(&smack_known_floor.smk_cipsolock);
3577 spin_lock_init(&smack_known_invalid.smk_cipsolock);
3578
3579 /*
3580 * Register with LSM
3581 */
3582 if (register_security(&smack_ops))
3583 panic("smack: Unable to register with kernel.\n");
3584
3585 return 0;
3586}
3587
3588/*
3589 * Smack requires early initialization in order to label
3590 * all processes and objects when they are created.
3591 */
3592security_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);