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