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1/*
2 * Simplified MAC Kernel (smack) security module
3 *
4 * This file contains the smack hook function implementations.
5 *
6 * Authors:
7 * Casey Schaufler <casey@schaufler-ca.com>
8 * Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com>
9 *
10 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
11 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
12 * Paul Moore <paul@paul-moore.com>
13 * Copyright (C) 2010 Nokia Corporation
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2,
17 * as published by the Free Software Foundation.
18 */
19
20#include <linux/xattr.h>
21#include <linux/pagemap.h>
22#include <linux/mount.h>
23#include <linux/stat.h>
24#include <linux/kd.h>
25#include <asm/ioctls.h>
26#include <linux/ip.h>
27#include <linux/tcp.h>
28#include <linux/udp.h>
29#include <linux/slab.h>
30#include <linux/mutex.h>
31#include <linux/pipe_fs_i.h>
32#include <net/netlabel.h>
33#include <net/cipso_ipv4.h>
34#include <linux/audit.h>
35#include <linux/magic.h>
36#include <linux/dcache.h>
37#include "smack.h"
38
39#define task_security(task) (task_cred_xxx((task), security))
40
41#define TRANS_TRUE "TRUE"
42#define TRANS_TRUE_SIZE 4
43
44/**
45 * smk_fetch - Fetch the smack label from a file.
46 * @ip: a pointer to the inode
47 * @dp: a pointer to the dentry
48 *
49 * Returns a pointer to the master list entry for the Smack label
50 * or NULL if there was no label to fetch.
51 */
52static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
53{
54 int rc;
55 char in[SMK_LABELLEN];
56
57 if (ip->i_op->getxattr == NULL)
58 return NULL;
59
60 rc = ip->i_op->getxattr(dp, name, in, SMK_LABELLEN);
61 if (rc < 0)
62 return NULL;
63
64 return smk_import(in, rc);
65}
66
67/**
68 * new_inode_smack - allocate an inode security blob
69 * @smack: a pointer to the Smack label to use in the blob
70 *
71 * Returns the new blob or NULL if there's no memory available
72 */
73struct inode_smack *new_inode_smack(char *smack)
74{
75 struct inode_smack *isp;
76
77 isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
78 if (isp == NULL)
79 return NULL;
80
81 isp->smk_inode = smack;
82 isp->smk_flags = 0;
83 mutex_init(&isp->smk_lock);
84
85 return isp;
86}
87
88/**
89 * new_task_smack - allocate a task security blob
90 * @smack: a pointer to the Smack label to use in the blob
91 *
92 * Returns the new blob or NULL if there's no memory available
93 */
94static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
95{
96 struct task_smack *tsp;
97
98 tsp = kzalloc(sizeof(struct task_smack), gfp);
99 if (tsp == NULL)
100 return NULL;
101
102 tsp->smk_task = task;
103 tsp->smk_forked = forked;
104 INIT_LIST_HEAD(&tsp->smk_rules);
105 mutex_init(&tsp->smk_rules_lock);
106
107 return tsp;
108}
109
110/**
111 * smk_copy_rules - copy a rule set
112 * @nhead - new rules header pointer
113 * @ohead - old rules header pointer
114 *
115 * Returns 0 on success, -ENOMEM on error
116 */
117static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
118 gfp_t gfp)
119{
120 struct smack_rule *nrp;
121 struct smack_rule *orp;
122 int rc = 0;
123
124 INIT_LIST_HEAD(nhead);
125
126 list_for_each_entry_rcu(orp, ohead, list) {
127 nrp = kzalloc(sizeof(struct smack_rule), gfp);
128 if (nrp == NULL) {
129 rc = -ENOMEM;
130 break;
131 }
132 *nrp = *orp;
133 list_add_rcu(&nrp->list, nhead);
134 }
135 return rc;
136}
137
138/*
139 * LSM hooks.
140 * We he, that is fun!
141 */
142
143/**
144 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
145 * @ctp: child task pointer
146 * @mode: ptrace attachment mode
147 *
148 * Returns 0 if access is OK, an error code otherwise
149 *
150 * Do the capability checks, and require read and write.
151 */
152static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
153{
154 int rc;
155 struct smk_audit_info ad;
156 char *tsp;
157
158 rc = cap_ptrace_access_check(ctp, mode);
159 if (rc != 0)
160 return rc;
161
162 tsp = smk_of_task(task_security(ctp));
163 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
164 smk_ad_setfield_u_tsk(&ad, ctp);
165
166 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
167 return rc;
168}
169
170/**
171 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
172 * @ptp: parent task pointer
173 *
174 * Returns 0 if access is OK, an error code otherwise
175 *
176 * Do the capability checks, and require read and write.
177 */
178static int smack_ptrace_traceme(struct task_struct *ptp)
179{
180 int rc;
181 struct smk_audit_info ad;
182 char *tsp;
183
184 rc = cap_ptrace_traceme(ptp);
185 if (rc != 0)
186 return rc;
187
188 tsp = smk_of_task(task_security(ptp));
189 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
190 smk_ad_setfield_u_tsk(&ad, ptp);
191
192 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
193 return rc;
194}
195
196/**
197 * smack_syslog - Smack approval on syslog
198 * @type: message type
199 *
200 * Require that the task has the floor label
201 *
202 * Returns 0 on success, error code otherwise.
203 */
204static int smack_syslog(int typefrom_file)
205{
206 int rc = 0;
207 char *sp = smk_of_current();
208
209 if (capable(CAP_MAC_OVERRIDE))
210 return 0;
211
212 if (sp != smack_known_floor.smk_known)
213 rc = -EACCES;
214
215 return rc;
216}
217
218
219/*
220 * Superblock Hooks.
221 */
222
223/**
224 * smack_sb_alloc_security - allocate a superblock blob
225 * @sb: the superblock getting the blob
226 *
227 * Returns 0 on success or -ENOMEM on error.
228 */
229static int smack_sb_alloc_security(struct super_block *sb)
230{
231 struct superblock_smack *sbsp;
232
233 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
234
235 if (sbsp == NULL)
236 return -ENOMEM;
237
238 sbsp->smk_root = smack_known_floor.smk_known;
239 sbsp->smk_default = smack_known_floor.smk_known;
240 sbsp->smk_floor = smack_known_floor.smk_known;
241 sbsp->smk_hat = smack_known_hat.smk_known;
242 sbsp->smk_initialized = 0;
243 spin_lock_init(&sbsp->smk_sblock);
244
245 sb->s_security = sbsp;
246
247 return 0;
248}
249
250/**
251 * smack_sb_free_security - free a superblock blob
252 * @sb: the superblock getting the blob
253 *
254 */
255static void smack_sb_free_security(struct super_block *sb)
256{
257 kfree(sb->s_security);
258 sb->s_security = NULL;
259}
260
261/**
262 * smack_sb_copy_data - copy mount options data for processing
263 * @orig: where to start
264 * @smackopts: mount options string
265 *
266 * Returns 0 on success or -ENOMEM on error.
267 *
268 * Copy the Smack specific mount options out of the mount
269 * options list.
270 */
271static int smack_sb_copy_data(char *orig, char *smackopts)
272{
273 char *cp, *commap, *otheropts, *dp;
274
275 otheropts = (char *)get_zeroed_page(GFP_KERNEL);
276 if (otheropts == NULL)
277 return -ENOMEM;
278
279 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
280 if (strstr(cp, SMK_FSDEFAULT) == cp)
281 dp = smackopts;
282 else if (strstr(cp, SMK_FSFLOOR) == cp)
283 dp = smackopts;
284 else if (strstr(cp, SMK_FSHAT) == cp)
285 dp = smackopts;
286 else if (strstr(cp, SMK_FSROOT) == cp)
287 dp = smackopts;
288 else
289 dp = otheropts;
290
291 commap = strchr(cp, ',');
292 if (commap != NULL)
293 *commap = '\0';
294
295 if (*dp != '\0')
296 strcat(dp, ",");
297 strcat(dp, cp);
298 }
299
300 strcpy(orig, otheropts);
301 free_page((unsigned long)otheropts);
302
303 return 0;
304}
305
306/**
307 * smack_sb_kern_mount - Smack specific mount processing
308 * @sb: the file system superblock
309 * @flags: the mount flags
310 * @data: the smack mount options
311 *
312 * Returns 0 on success, an error code on failure
313 */
314static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
315{
316 struct dentry *root = sb->s_root;
317 struct inode *inode = root->d_inode;
318 struct superblock_smack *sp = sb->s_security;
319 struct inode_smack *isp;
320 char *op;
321 char *commap;
322 char *nsp;
323
324 spin_lock(&sp->smk_sblock);
325 if (sp->smk_initialized != 0) {
326 spin_unlock(&sp->smk_sblock);
327 return 0;
328 }
329 sp->smk_initialized = 1;
330 spin_unlock(&sp->smk_sblock);
331
332 for (op = data; op != NULL; op = commap) {
333 commap = strchr(op, ',');
334 if (commap != NULL)
335 *commap++ = '\0';
336
337 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
338 op += strlen(SMK_FSHAT);
339 nsp = smk_import(op, 0);
340 if (nsp != NULL)
341 sp->smk_hat = nsp;
342 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
343 op += strlen(SMK_FSFLOOR);
344 nsp = smk_import(op, 0);
345 if (nsp != NULL)
346 sp->smk_floor = nsp;
347 } else if (strncmp(op, SMK_FSDEFAULT,
348 strlen(SMK_FSDEFAULT)) == 0) {
349 op += strlen(SMK_FSDEFAULT);
350 nsp = smk_import(op, 0);
351 if (nsp != NULL)
352 sp->smk_default = nsp;
353 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
354 op += strlen(SMK_FSROOT);
355 nsp = smk_import(op, 0);
356 if (nsp != NULL)
357 sp->smk_root = nsp;
358 }
359 }
360
361 /*
362 * Initialize the root inode.
363 */
364 isp = inode->i_security;
365 if (isp == NULL)
366 inode->i_security = new_inode_smack(sp->smk_root);
367 else
368 isp->smk_inode = sp->smk_root;
369
370 return 0;
371}
372
373/**
374 * smack_sb_statfs - Smack check on statfs
375 * @dentry: identifies the file system in question
376 *
377 * Returns 0 if current can read the floor of the filesystem,
378 * and error code otherwise
379 */
380static int smack_sb_statfs(struct dentry *dentry)
381{
382 struct superblock_smack *sbp = dentry->d_sb->s_security;
383 int rc;
384 struct smk_audit_info ad;
385
386 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
387 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
388
389 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
390 return rc;
391}
392
393/**
394 * smack_sb_mount - Smack check for mounting
395 * @dev_name: unused
396 * @path: mount point
397 * @type: unused
398 * @flags: unused
399 * @data: unused
400 *
401 * Returns 0 if current can write the floor of the filesystem
402 * being mounted on, an error code otherwise.
403 */
404static int smack_sb_mount(char *dev_name, struct path *path,
405 char *type, unsigned long flags, void *data)
406{
407 struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
408 struct smk_audit_info ad;
409
410 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
411 smk_ad_setfield_u_fs_path(&ad, *path);
412
413 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
414}
415
416/**
417 * smack_sb_umount - Smack check for unmounting
418 * @mnt: file system to unmount
419 * @flags: unused
420 *
421 * Returns 0 if current can write the floor of the filesystem
422 * being unmounted, an error code otherwise.
423 */
424static int smack_sb_umount(struct vfsmount *mnt, int flags)
425{
426 struct superblock_smack *sbp;
427 struct smk_audit_info ad;
428 struct path path;
429
430 path.dentry = mnt->mnt_root;
431 path.mnt = mnt;
432
433 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
434 smk_ad_setfield_u_fs_path(&ad, path);
435
436 sbp = mnt->mnt_sb->s_security;
437 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
438}
439
440/*
441 * BPRM hooks
442 */
443
444static int smack_bprm_set_creds(struct linux_binprm *bprm)
445{
446 struct task_smack *tsp = bprm->cred->security;
447 struct inode_smack *isp;
448 struct dentry *dp;
449 int rc;
450
451 rc = cap_bprm_set_creds(bprm);
452 if (rc != 0)
453 return rc;
454
455 if (bprm->cred_prepared)
456 return 0;
457
458 if (bprm->file == NULL || bprm->file->f_dentry == NULL)
459 return 0;
460
461 dp = bprm->file->f_dentry;
462
463 if (dp->d_inode == NULL)
464 return 0;
465
466 isp = dp->d_inode->i_security;
467
468 if (isp->smk_task != NULL)
469 tsp->smk_task = isp->smk_task;
470
471 return 0;
472}
473
474/*
475 * Inode hooks
476 */
477
478/**
479 * smack_inode_alloc_security - allocate an inode blob
480 * @inode: the inode in need of a blob
481 *
482 * Returns 0 if it gets a blob, -ENOMEM otherwise
483 */
484static int smack_inode_alloc_security(struct inode *inode)
485{
486 inode->i_security = new_inode_smack(smk_of_current());
487 if (inode->i_security == NULL)
488 return -ENOMEM;
489 return 0;
490}
491
492/**
493 * smack_inode_free_security - free an inode blob
494 * @inode: the inode with a blob
495 *
496 * Clears the blob pointer in inode
497 */
498static void smack_inode_free_security(struct inode *inode)
499{
500 kfree(inode->i_security);
501 inode->i_security = NULL;
502}
503
504/**
505 * smack_inode_init_security - copy out the smack from an inode
506 * @inode: the inode
507 * @dir: unused
508 * @qstr: unused
509 * @name: where to put the attribute name
510 * @value: where to put the attribute value
511 * @len: where to put the length of the attribute
512 *
513 * Returns 0 if it all works out, -ENOMEM if there's no memory
514 */
515static int smack_inode_init_security(struct inode *inode, struct inode *dir,
516 const struct qstr *qstr, char **name,
517 void **value, size_t *len)
518{
519 char *isp = smk_of_inode(inode);
520 char *dsp = smk_of_inode(dir);
521 int may;
522
523 if (name) {
524 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
525 if (*name == NULL)
526 return -ENOMEM;
527 }
528
529 if (value) {
530 rcu_read_lock();
531 may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
532 rcu_read_unlock();
533
534 /*
535 * If the access rule allows transmutation and
536 * the directory requests transmutation then
537 * by all means transmute.
538 */
539 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
540 smk_inode_transmutable(dir))
541 isp = dsp;
542
543 *value = kstrdup(isp, GFP_KERNEL);
544 if (*value == NULL)
545 return -ENOMEM;
546 }
547
548 if (len)
549 *len = strlen(isp) + 1;
550
551 return 0;
552}
553
554/**
555 * smack_inode_link - Smack check on link
556 * @old_dentry: the existing object
557 * @dir: unused
558 * @new_dentry: the new object
559 *
560 * Returns 0 if access is permitted, an error code otherwise
561 */
562static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
563 struct dentry *new_dentry)
564{
565 char *isp;
566 struct smk_audit_info ad;
567 int rc;
568
569 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
570 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
571
572 isp = smk_of_inode(old_dentry->d_inode);
573 rc = smk_curacc(isp, MAY_WRITE, &ad);
574
575 if (rc == 0 && new_dentry->d_inode != NULL) {
576 isp = smk_of_inode(new_dentry->d_inode);
577 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
578 rc = smk_curacc(isp, MAY_WRITE, &ad);
579 }
580
581 return rc;
582}
583
584/**
585 * smack_inode_unlink - Smack check on inode deletion
586 * @dir: containing directory object
587 * @dentry: file to unlink
588 *
589 * Returns 0 if current can write the containing directory
590 * and the object, error code otherwise
591 */
592static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
593{
594 struct inode *ip = dentry->d_inode;
595 struct smk_audit_info ad;
596 int rc;
597
598 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
599 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
600
601 /*
602 * You need write access to the thing you're unlinking
603 */
604 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
605 if (rc == 0) {
606 /*
607 * You also need write access to the containing directory
608 */
609 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
610 smk_ad_setfield_u_fs_inode(&ad, dir);
611 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
612 }
613 return rc;
614}
615
616/**
617 * smack_inode_rmdir - Smack check on directory deletion
618 * @dir: containing directory object
619 * @dentry: directory to unlink
620 *
621 * Returns 0 if current can write the containing directory
622 * and the directory, error code otherwise
623 */
624static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
625{
626 struct smk_audit_info ad;
627 int rc;
628
629 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
630 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
631
632 /*
633 * You need write access to the thing you're removing
634 */
635 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
636 if (rc == 0) {
637 /*
638 * You also need write access to the containing directory
639 */
640 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
641 smk_ad_setfield_u_fs_inode(&ad, dir);
642 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
643 }
644
645 return rc;
646}
647
648/**
649 * smack_inode_rename - Smack check on rename
650 * @old_inode: the old directory
651 * @old_dentry: unused
652 * @new_inode: the new directory
653 * @new_dentry: unused
654 *
655 * Read and write access is required on both the old and
656 * new directories.
657 *
658 * Returns 0 if access is permitted, an error code otherwise
659 */
660static int smack_inode_rename(struct inode *old_inode,
661 struct dentry *old_dentry,
662 struct inode *new_inode,
663 struct dentry *new_dentry)
664{
665 int rc;
666 char *isp;
667 struct smk_audit_info ad;
668
669 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
670 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
671
672 isp = smk_of_inode(old_dentry->d_inode);
673 rc = smk_curacc(isp, MAY_READWRITE, &ad);
674
675 if (rc == 0 && new_dentry->d_inode != NULL) {
676 isp = smk_of_inode(new_dentry->d_inode);
677 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
678 rc = smk_curacc(isp, MAY_READWRITE, &ad);
679 }
680 return rc;
681}
682
683/**
684 * smack_inode_permission - Smack version of permission()
685 * @inode: the inode in question
686 * @mask: the access requested
687 *
688 * This is the important Smack hook.
689 *
690 * Returns 0 if access is permitted, -EACCES otherwise
691 */
692static int smack_inode_permission(struct inode *inode, int mask)
693{
694 struct smk_audit_info ad;
695 int no_block = mask & MAY_NOT_BLOCK;
696
697 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
698 /*
699 * No permission to check. Existence test. Yup, it's there.
700 */
701 if (mask == 0)
702 return 0;
703
704 /* May be droppable after audit */
705 if (no_block)
706 return -ECHILD;
707 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
708 smk_ad_setfield_u_fs_inode(&ad, inode);
709 return smk_curacc(smk_of_inode(inode), mask, &ad);
710}
711
712/**
713 * smack_inode_setattr - Smack check for setting attributes
714 * @dentry: the object
715 * @iattr: for the force flag
716 *
717 * Returns 0 if access is permitted, an error code otherwise
718 */
719static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
720{
721 struct smk_audit_info ad;
722 /*
723 * Need to allow for clearing the setuid bit.
724 */
725 if (iattr->ia_valid & ATTR_FORCE)
726 return 0;
727 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
728 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
729
730 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
731}
732
733/**
734 * smack_inode_getattr - Smack check for getting attributes
735 * @mnt: unused
736 * @dentry: the object
737 *
738 * Returns 0 if access is permitted, an error code otherwise
739 */
740static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
741{
742 struct smk_audit_info ad;
743 struct path path;
744
745 path.dentry = dentry;
746 path.mnt = mnt;
747
748 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
749 smk_ad_setfield_u_fs_path(&ad, path);
750 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
751}
752
753/**
754 * smack_inode_setxattr - Smack check for setting xattrs
755 * @dentry: the object
756 * @name: name of the attribute
757 * @value: unused
758 * @size: unused
759 * @flags: unused
760 *
761 * This protects the Smack attribute explicitly.
762 *
763 * Returns 0 if access is permitted, an error code otherwise
764 */
765static int smack_inode_setxattr(struct dentry *dentry, const char *name,
766 const void *value, size_t size, int flags)
767{
768 struct smk_audit_info ad;
769 int rc = 0;
770
771 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
772 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
773 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
774 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
775 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
776 if (!capable(CAP_MAC_ADMIN))
777 rc = -EPERM;
778 /*
779 * check label validity here so import wont fail on
780 * post_setxattr
781 */
782 if (size == 0 || size >= SMK_LABELLEN ||
783 smk_import(value, size) == NULL)
784 rc = -EINVAL;
785 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
786 if (!capable(CAP_MAC_ADMIN))
787 rc = -EPERM;
788 if (size != TRANS_TRUE_SIZE ||
789 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
790 rc = -EINVAL;
791 } else
792 rc = cap_inode_setxattr(dentry, name, value, size, flags);
793
794 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
795 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
796
797 if (rc == 0)
798 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
799
800 return rc;
801}
802
803/**
804 * smack_inode_post_setxattr - Apply the Smack update approved above
805 * @dentry: object
806 * @name: attribute name
807 * @value: attribute value
808 * @size: attribute size
809 * @flags: unused
810 *
811 * Set the pointer in the inode blob to the entry found
812 * in the master label list.
813 */
814static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
815 const void *value, size_t size, int flags)
816{
817 char *nsp;
818 struct inode_smack *isp = dentry->d_inode->i_security;
819
820 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
821 nsp = smk_import(value, size);
822 if (nsp != NULL)
823 isp->smk_inode = nsp;
824 else
825 isp->smk_inode = smack_known_invalid.smk_known;
826 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
827 nsp = smk_import(value, size);
828 if (nsp != NULL)
829 isp->smk_task = nsp;
830 else
831 isp->smk_task = smack_known_invalid.smk_known;
832 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
833 nsp = smk_import(value, size);
834 if (nsp != NULL)
835 isp->smk_mmap = nsp;
836 else
837 isp->smk_mmap = smack_known_invalid.smk_known;
838 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
839 isp->smk_flags |= SMK_INODE_TRANSMUTE;
840
841 return;
842}
843
844/*
845 * smack_inode_getxattr - Smack check on getxattr
846 * @dentry: the object
847 * @name: unused
848 *
849 * Returns 0 if access is permitted, an error code otherwise
850 */
851static int smack_inode_getxattr(struct dentry *dentry, const char *name)
852{
853 struct smk_audit_info ad;
854
855 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
856 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
857
858 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
859}
860
861/*
862 * smack_inode_removexattr - Smack check on removexattr
863 * @dentry: the object
864 * @name: name of the attribute
865 *
866 * Removing the Smack attribute requires CAP_MAC_ADMIN
867 *
868 * Returns 0 if access is permitted, an error code otherwise
869 */
870static int smack_inode_removexattr(struct dentry *dentry, const char *name)
871{
872 struct inode_smack *isp;
873 struct smk_audit_info ad;
874 int rc = 0;
875
876 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
877 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
878 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
879 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
880 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
881 strcmp(name, XATTR_NAME_SMACKMMAP)) {
882 if (!capable(CAP_MAC_ADMIN))
883 rc = -EPERM;
884 } else
885 rc = cap_inode_removexattr(dentry, name);
886
887 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
888 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
889 if (rc == 0)
890 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
891
892 if (rc == 0) {
893 isp = dentry->d_inode->i_security;
894 isp->smk_task = NULL;
895 isp->smk_mmap = NULL;
896 }
897
898 return rc;
899}
900
901/**
902 * smack_inode_getsecurity - get smack xattrs
903 * @inode: the object
904 * @name: attribute name
905 * @buffer: where to put the result
906 * @alloc: unused
907 *
908 * Returns the size of the attribute or an error code
909 */
910static int smack_inode_getsecurity(const struct inode *inode,
911 const char *name, void **buffer,
912 bool alloc)
913{
914 struct socket_smack *ssp;
915 struct socket *sock;
916 struct super_block *sbp;
917 struct inode *ip = (struct inode *)inode;
918 char *isp;
919 int ilen;
920 int rc = 0;
921
922 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
923 isp = smk_of_inode(inode);
924 ilen = strlen(isp) + 1;
925 *buffer = isp;
926 return ilen;
927 }
928
929 /*
930 * The rest of the Smack xattrs are only on sockets.
931 */
932 sbp = ip->i_sb;
933 if (sbp->s_magic != SOCKFS_MAGIC)
934 return -EOPNOTSUPP;
935
936 sock = SOCKET_I(ip);
937 if (sock == NULL || sock->sk == NULL)
938 return -EOPNOTSUPP;
939
940 ssp = sock->sk->sk_security;
941
942 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
943 isp = ssp->smk_in;
944 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
945 isp = ssp->smk_out;
946 else
947 return -EOPNOTSUPP;
948
949 ilen = strlen(isp) + 1;
950 if (rc == 0) {
951 *buffer = isp;
952 rc = ilen;
953 }
954
955 return rc;
956}
957
958
959/**
960 * smack_inode_listsecurity - list the Smack attributes
961 * @inode: the object
962 * @buffer: where they go
963 * @buffer_size: size of buffer
964 *
965 * Returns 0 on success, -EINVAL otherwise
966 */
967static int smack_inode_listsecurity(struct inode *inode, char *buffer,
968 size_t buffer_size)
969{
970 int len = strlen(XATTR_NAME_SMACK);
971
972 if (buffer != NULL && len <= buffer_size) {
973 memcpy(buffer, XATTR_NAME_SMACK, len);
974 return len;
975 }
976 return -EINVAL;
977}
978
979/**
980 * smack_inode_getsecid - Extract inode's security id
981 * @inode: inode to extract the info from
982 * @secid: where result will be saved
983 */
984static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
985{
986 struct inode_smack *isp = inode->i_security;
987
988 *secid = smack_to_secid(isp->smk_inode);
989}
990
991/*
992 * File Hooks
993 */
994
995/**
996 * smack_file_permission - Smack check on file operations
997 * @file: unused
998 * @mask: unused
999 *
1000 * Returns 0
1001 *
1002 * Should access checks be done on each read or write?
1003 * UNICOS and SELinux say yes.
1004 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1005 *
1006 * I'll say no for now. Smack does not do the frequent
1007 * label changing that SELinux does.
1008 */
1009static int smack_file_permission(struct file *file, int mask)
1010{
1011 return 0;
1012}
1013
1014/**
1015 * smack_file_alloc_security - assign a file security blob
1016 * @file: the object
1017 *
1018 * The security blob for a file is a pointer to the master
1019 * label list, so no allocation is done.
1020 *
1021 * Returns 0
1022 */
1023static int smack_file_alloc_security(struct file *file)
1024{
1025 file->f_security = smk_of_current();
1026 return 0;
1027}
1028
1029/**
1030 * smack_file_free_security - clear a file security blob
1031 * @file: the object
1032 *
1033 * The security blob for a file is a pointer to the master
1034 * label list, so no memory is freed.
1035 */
1036static void smack_file_free_security(struct file *file)
1037{
1038 file->f_security = NULL;
1039}
1040
1041/**
1042 * smack_file_ioctl - Smack check on ioctls
1043 * @file: the object
1044 * @cmd: what to do
1045 * @arg: unused
1046 *
1047 * Relies heavily on the correct use of the ioctl command conventions.
1048 *
1049 * Returns 0 if allowed, error code otherwise
1050 */
1051static int smack_file_ioctl(struct file *file, unsigned int cmd,
1052 unsigned long arg)
1053{
1054 int rc = 0;
1055 struct smk_audit_info ad;
1056
1057 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1058 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1059
1060 if (_IOC_DIR(cmd) & _IOC_WRITE)
1061 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1062
1063 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1064 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1065
1066 return rc;
1067}
1068
1069/**
1070 * smack_file_lock - Smack check on file locking
1071 * @file: the object
1072 * @cmd: unused
1073 *
1074 * Returns 0 if current has write access, error code otherwise
1075 */
1076static int smack_file_lock(struct file *file, unsigned int cmd)
1077{
1078 struct smk_audit_info ad;
1079
1080 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1081 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1082 return smk_curacc(file->f_security, MAY_WRITE, &ad);
1083}
1084
1085/**
1086 * smack_file_fcntl - Smack check on fcntl
1087 * @file: the object
1088 * @cmd: what action to check
1089 * @arg: unused
1090 *
1091 * Returns 0 if current has access, error code otherwise
1092 */
1093static int smack_file_fcntl(struct file *file, unsigned int cmd,
1094 unsigned long arg)
1095{
1096 struct smk_audit_info ad;
1097 int rc;
1098
1099 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1100 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1101
1102 switch (cmd) {
1103 case F_DUPFD:
1104 case F_GETFD:
1105 case F_GETFL:
1106 case F_GETLK:
1107 case F_GETOWN:
1108 case F_GETSIG:
1109 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1110 break;
1111 case F_SETFD:
1112 case F_SETFL:
1113 case F_SETLK:
1114 case F_SETLKW:
1115 case F_SETOWN:
1116 case F_SETSIG:
1117 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1118 break;
1119 default:
1120 rc = smk_curacc(file->f_security, MAY_READWRITE, &ad);
1121 }
1122
1123 return rc;
1124}
1125
1126/**
1127 * smack_file_mmap :
1128 * Check permissions for a mmap operation. The @file may be NULL, e.g.
1129 * if mapping anonymous memory.
1130 * @file contains the file structure for file to map (may be NULL).
1131 * @reqprot contains the protection requested by the application.
1132 * @prot contains the protection that will be applied by the kernel.
1133 * @flags contains the operational flags.
1134 * Return 0 if permission is granted.
1135 */
1136static int smack_file_mmap(struct file *file,
1137 unsigned long reqprot, unsigned long prot,
1138 unsigned long flags, unsigned long addr,
1139 unsigned long addr_only)
1140{
1141 struct smack_rule *srp;
1142 struct task_smack *tsp;
1143 char *sp;
1144 char *msmack;
1145 char *osmack;
1146 struct inode_smack *isp;
1147 struct dentry *dp;
1148 int may;
1149 int mmay;
1150 int tmay;
1151 int rc;
1152
1153 /* do DAC check on address space usage */
1154 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
1155 if (rc || addr_only)
1156 return rc;
1157
1158 if (file == NULL || file->f_dentry == NULL)
1159 return 0;
1160
1161 dp = file->f_dentry;
1162
1163 if (dp->d_inode == NULL)
1164 return 0;
1165
1166 isp = dp->d_inode->i_security;
1167 if (isp->smk_mmap == NULL)
1168 return 0;
1169 msmack = isp->smk_mmap;
1170
1171 tsp = current_security();
1172 sp = smk_of_current();
1173 rc = 0;
1174
1175 rcu_read_lock();
1176 /*
1177 * For each Smack rule associated with the subject
1178 * label verify that the SMACK64MMAP also has access
1179 * to that rule's object label.
1180 *
1181 * Because neither of the labels comes
1182 * from the networking code it is sufficient
1183 * to compare pointers.
1184 */
1185 list_for_each_entry_rcu(srp, &smack_rule_list, list) {
1186 if (srp->smk_subject != sp)
1187 continue;
1188
1189 osmack = srp->smk_object;
1190 /*
1191 * Matching labels always allows access.
1192 */
1193 if (msmack == osmack)
1194 continue;
1195 /*
1196 * If there is a matching local rule take
1197 * that into account as well.
1198 */
1199 may = smk_access_entry(srp->smk_subject, osmack,
1200 &tsp->smk_rules);
1201 if (may == -ENOENT)
1202 may = srp->smk_access;
1203 else
1204 may &= srp->smk_access;
1205 /*
1206 * If may is zero the SMACK64MMAP subject can't
1207 * possibly have less access.
1208 */
1209 if (may == 0)
1210 continue;
1211
1212 /*
1213 * Fetch the global list entry.
1214 * If there isn't one a SMACK64MMAP subject
1215 * can't have as much access as current.
1216 */
1217 mmay = smk_access_entry(msmack, osmack, &smack_rule_list);
1218 if (mmay == -ENOENT) {
1219 rc = -EACCES;
1220 break;
1221 }
1222 /*
1223 * If there is a local entry it modifies the
1224 * potential access, too.
1225 */
1226 tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules);
1227 if (tmay != -ENOENT)
1228 mmay &= tmay;
1229
1230 /*
1231 * If there is any access available to current that is
1232 * not available to a SMACK64MMAP subject
1233 * deny access.
1234 */
1235 if ((may | mmay) != mmay) {
1236 rc = -EACCES;
1237 break;
1238 }
1239 }
1240
1241 rcu_read_unlock();
1242
1243 return rc;
1244}
1245
1246/**
1247 * smack_file_set_fowner - set the file security blob value
1248 * @file: object in question
1249 *
1250 * Returns 0
1251 * Further research may be required on this one.
1252 */
1253static int smack_file_set_fowner(struct file *file)
1254{
1255 file->f_security = smk_of_current();
1256 return 0;
1257}
1258
1259/**
1260 * smack_file_send_sigiotask - Smack on sigio
1261 * @tsk: The target task
1262 * @fown: the object the signal come from
1263 * @signum: unused
1264 *
1265 * Allow a privileged task to get signals even if it shouldn't
1266 *
1267 * Returns 0 if a subject with the object's smack could
1268 * write to the task, an error code otherwise.
1269 */
1270static int smack_file_send_sigiotask(struct task_struct *tsk,
1271 struct fown_struct *fown, int signum)
1272{
1273 struct file *file;
1274 int rc;
1275 char *tsp = smk_of_task(tsk->cred->security);
1276 struct smk_audit_info ad;
1277
1278 /*
1279 * struct fown_struct is never outside the context of a struct file
1280 */
1281 file = container_of(fown, struct file, f_owner);
1282
1283 /* we don't log here as rc can be overriden */
1284 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1285 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1286 rc = 0;
1287
1288 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1289 smk_ad_setfield_u_tsk(&ad, tsk);
1290 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1291 return rc;
1292}
1293
1294/**
1295 * smack_file_receive - Smack file receive check
1296 * @file: the object
1297 *
1298 * Returns 0 if current has access, error code otherwise
1299 */
1300static int smack_file_receive(struct file *file)
1301{
1302 int may = 0;
1303 struct smk_audit_info ad;
1304
1305 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1306 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1307 /*
1308 * This code relies on bitmasks.
1309 */
1310 if (file->f_mode & FMODE_READ)
1311 may = MAY_READ;
1312 if (file->f_mode & FMODE_WRITE)
1313 may |= MAY_WRITE;
1314
1315 return smk_curacc(file->f_security, may, &ad);
1316}
1317
1318/*
1319 * Task hooks
1320 */
1321
1322/**
1323 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1324 * @new: the new credentials
1325 * @gfp: the atomicity of any memory allocations
1326 *
1327 * Prepare a blank set of credentials for modification. This must allocate all
1328 * the memory the LSM module might require such that cred_transfer() can
1329 * complete without error.
1330 */
1331static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1332{
1333 struct task_smack *tsp;
1334
1335 tsp = new_task_smack(NULL, NULL, gfp);
1336 if (tsp == NULL)
1337 return -ENOMEM;
1338
1339 cred->security = tsp;
1340
1341 return 0;
1342}
1343
1344
1345/**
1346 * smack_cred_free - "free" task-level security credentials
1347 * @cred: the credentials in question
1348 *
1349 */
1350static void smack_cred_free(struct cred *cred)
1351{
1352 struct task_smack *tsp = cred->security;
1353 struct smack_rule *rp;
1354 struct list_head *l;
1355 struct list_head *n;
1356
1357 if (tsp == NULL)
1358 return;
1359 cred->security = NULL;
1360
1361 list_for_each_safe(l, n, &tsp->smk_rules) {
1362 rp = list_entry(l, struct smack_rule, list);
1363 list_del(&rp->list);
1364 kfree(rp);
1365 }
1366 kfree(tsp);
1367}
1368
1369/**
1370 * smack_cred_prepare - prepare new set of credentials for modification
1371 * @new: the new credentials
1372 * @old: the original credentials
1373 * @gfp: the atomicity of any memory allocations
1374 *
1375 * Prepare a new set of credentials for modification.
1376 */
1377static int smack_cred_prepare(struct cred *new, const struct cred *old,
1378 gfp_t gfp)
1379{
1380 struct task_smack *old_tsp = old->security;
1381 struct task_smack *new_tsp;
1382 int rc;
1383
1384 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1385 if (new_tsp == NULL)
1386 return -ENOMEM;
1387
1388 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1389 if (rc != 0)
1390 return rc;
1391
1392 new->security = new_tsp;
1393 return 0;
1394}
1395
1396/**
1397 * smack_cred_transfer - Transfer the old credentials to the new credentials
1398 * @new: the new credentials
1399 * @old: the original credentials
1400 *
1401 * Fill in a set of blank credentials from another set of credentials.
1402 */
1403static void smack_cred_transfer(struct cred *new, const struct cred *old)
1404{
1405 struct task_smack *old_tsp = old->security;
1406 struct task_smack *new_tsp = new->security;
1407
1408 new_tsp->smk_task = old_tsp->smk_task;
1409 new_tsp->smk_forked = old_tsp->smk_task;
1410 mutex_init(&new_tsp->smk_rules_lock);
1411 INIT_LIST_HEAD(&new_tsp->smk_rules);
1412
1413
1414 /* cbs copy rule list */
1415}
1416
1417/**
1418 * smack_kernel_act_as - Set the subjective context in a set of credentials
1419 * @new: points to the set of credentials to be modified.
1420 * @secid: specifies the security ID to be set
1421 *
1422 * Set the security data for a kernel service.
1423 */
1424static int smack_kernel_act_as(struct cred *new, u32 secid)
1425{
1426 struct task_smack *new_tsp = new->security;
1427 char *smack = smack_from_secid(secid);
1428
1429 if (smack == NULL)
1430 return -EINVAL;
1431
1432 new_tsp->smk_task = smack;
1433 return 0;
1434}
1435
1436/**
1437 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1438 * @new: points to the set of credentials to be modified
1439 * @inode: points to the inode to use as a reference
1440 *
1441 * Set the file creation context in a set of credentials to the same
1442 * as the objective context of the specified inode
1443 */
1444static int smack_kernel_create_files_as(struct cred *new,
1445 struct inode *inode)
1446{
1447 struct inode_smack *isp = inode->i_security;
1448 struct task_smack *tsp = new->security;
1449
1450 tsp->smk_forked = isp->smk_inode;
1451 tsp->smk_task = isp->smk_inode;
1452 return 0;
1453}
1454
1455/**
1456 * smk_curacc_on_task - helper to log task related access
1457 * @p: the task object
1458 * @access : the access requested
1459 *
1460 * Return 0 if access is permitted
1461 */
1462static int smk_curacc_on_task(struct task_struct *p, int access)
1463{
1464 struct smk_audit_info ad;
1465
1466 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1467 smk_ad_setfield_u_tsk(&ad, p);
1468 return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1469}
1470
1471/**
1472 * smack_task_setpgid - Smack check on setting pgid
1473 * @p: the task object
1474 * @pgid: unused
1475 *
1476 * Return 0 if write access is permitted
1477 */
1478static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1479{
1480 return smk_curacc_on_task(p, MAY_WRITE);
1481}
1482
1483/**
1484 * smack_task_getpgid - Smack access check for getpgid
1485 * @p: the object task
1486 *
1487 * Returns 0 if current can read the object task, error code otherwise
1488 */
1489static int smack_task_getpgid(struct task_struct *p)
1490{
1491 return smk_curacc_on_task(p, MAY_READ);
1492}
1493
1494/**
1495 * smack_task_getsid - Smack access check for getsid
1496 * @p: the object task
1497 *
1498 * Returns 0 if current can read the object task, error code otherwise
1499 */
1500static int smack_task_getsid(struct task_struct *p)
1501{
1502 return smk_curacc_on_task(p, MAY_READ);
1503}
1504
1505/**
1506 * smack_task_getsecid - get the secid of the task
1507 * @p: the object task
1508 * @secid: where to put the result
1509 *
1510 * Sets the secid to contain a u32 version of the smack label.
1511 */
1512static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1513{
1514 *secid = smack_to_secid(smk_of_task(task_security(p)));
1515}
1516
1517/**
1518 * smack_task_setnice - Smack check on setting nice
1519 * @p: the task object
1520 * @nice: unused
1521 *
1522 * Return 0 if write access is permitted
1523 */
1524static int smack_task_setnice(struct task_struct *p, int nice)
1525{
1526 int rc;
1527
1528 rc = cap_task_setnice(p, nice);
1529 if (rc == 0)
1530 rc = smk_curacc_on_task(p, MAY_WRITE);
1531 return rc;
1532}
1533
1534/**
1535 * smack_task_setioprio - Smack check on setting ioprio
1536 * @p: the task object
1537 * @ioprio: unused
1538 *
1539 * Return 0 if write access is permitted
1540 */
1541static int smack_task_setioprio(struct task_struct *p, int ioprio)
1542{
1543 int rc;
1544
1545 rc = cap_task_setioprio(p, ioprio);
1546 if (rc == 0)
1547 rc = smk_curacc_on_task(p, MAY_WRITE);
1548 return rc;
1549}
1550
1551/**
1552 * smack_task_getioprio - Smack check on reading ioprio
1553 * @p: the task object
1554 *
1555 * Return 0 if read access is permitted
1556 */
1557static int smack_task_getioprio(struct task_struct *p)
1558{
1559 return smk_curacc_on_task(p, MAY_READ);
1560}
1561
1562/**
1563 * smack_task_setscheduler - Smack check on setting scheduler
1564 * @p: the task object
1565 * @policy: unused
1566 * @lp: unused
1567 *
1568 * Return 0 if read access is permitted
1569 */
1570static int smack_task_setscheduler(struct task_struct *p)
1571{
1572 int rc;
1573
1574 rc = cap_task_setscheduler(p);
1575 if (rc == 0)
1576 rc = smk_curacc_on_task(p, MAY_WRITE);
1577 return rc;
1578}
1579
1580/**
1581 * smack_task_getscheduler - Smack check on reading scheduler
1582 * @p: the task object
1583 *
1584 * Return 0 if read access is permitted
1585 */
1586static int smack_task_getscheduler(struct task_struct *p)
1587{
1588 return smk_curacc_on_task(p, MAY_READ);
1589}
1590
1591/**
1592 * smack_task_movememory - Smack check on moving memory
1593 * @p: the task object
1594 *
1595 * Return 0 if write access is permitted
1596 */
1597static int smack_task_movememory(struct task_struct *p)
1598{
1599 return smk_curacc_on_task(p, MAY_WRITE);
1600}
1601
1602/**
1603 * smack_task_kill - Smack check on signal delivery
1604 * @p: the task object
1605 * @info: unused
1606 * @sig: unused
1607 * @secid: identifies the smack to use in lieu of current's
1608 *
1609 * Return 0 if write access is permitted
1610 *
1611 * The secid behavior is an artifact of an SELinux hack
1612 * in the USB code. Someday it may go away.
1613 */
1614static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1615 int sig, u32 secid)
1616{
1617 struct smk_audit_info ad;
1618
1619 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1620 smk_ad_setfield_u_tsk(&ad, p);
1621 /*
1622 * Sending a signal requires that the sender
1623 * can write the receiver.
1624 */
1625 if (secid == 0)
1626 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1627 &ad);
1628 /*
1629 * If the secid isn't 0 we're dealing with some USB IO
1630 * specific behavior. This is not clean. For one thing
1631 * we can't take privilege into account.
1632 */
1633 return smk_access(smack_from_secid(secid),
1634 smk_of_task(task_security(p)), MAY_WRITE, &ad);
1635}
1636
1637/**
1638 * smack_task_wait - Smack access check for waiting
1639 * @p: task to wait for
1640 *
1641 * Returns 0 if current can wait for p, error code otherwise
1642 */
1643static int smack_task_wait(struct task_struct *p)
1644{
1645 struct smk_audit_info ad;
1646 char *sp = smk_of_current();
1647 char *tsp = smk_of_forked(task_security(p));
1648 int rc;
1649
1650 /* we don't log here, we can be overriden */
1651 rc = smk_access(tsp, sp, MAY_WRITE, NULL);
1652 if (rc == 0)
1653 goto out_log;
1654
1655 /*
1656 * Allow the operation to succeed if either task
1657 * has privilege to perform operations that might
1658 * account for the smack labels having gotten to
1659 * be different in the first place.
1660 *
1661 * This breaks the strict subject/object access
1662 * control ideal, taking the object's privilege
1663 * state into account in the decision as well as
1664 * the smack value.
1665 */
1666 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1667 rc = 0;
1668 /* we log only if we didn't get overriden */
1669 out_log:
1670 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1671 smk_ad_setfield_u_tsk(&ad, p);
1672 smack_log(tsp, sp, MAY_WRITE, rc, &ad);
1673 return rc;
1674}
1675
1676/**
1677 * smack_task_to_inode - copy task smack into the inode blob
1678 * @p: task to copy from
1679 * @inode: inode to copy to
1680 *
1681 * Sets the smack pointer in the inode security blob
1682 */
1683static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1684{
1685 struct inode_smack *isp = inode->i_security;
1686 isp->smk_inode = smk_of_task(task_security(p));
1687}
1688
1689/*
1690 * Socket hooks.
1691 */
1692
1693/**
1694 * smack_sk_alloc_security - Allocate a socket blob
1695 * @sk: the socket
1696 * @family: unused
1697 * @gfp_flags: memory allocation flags
1698 *
1699 * Assign Smack pointers to current
1700 *
1701 * Returns 0 on success, -ENOMEM is there's no memory
1702 */
1703static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1704{
1705 char *csp = smk_of_current();
1706 struct socket_smack *ssp;
1707
1708 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1709 if (ssp == NULL)
1710 return -ENOMEM;
1711
1712 ssp->smk_in = csp;
1713 ssp->smk_out = csp;
1714 ssp->smk_packet[0] = '\0';
1715
1716 sk->sk_security = ssp;
1717
1718 return 0;
1719}
1720
1721/**
1722 * smack_sk_free_security - Free a socket blob
1723 * @sk: the socket
1724 *
1725 * Clears the blob pointer
1726 */
1727static void smack_sk_free_security(struct sock *sk)
1728{
1729 kfree(sk->sk_security);
1730}
1731
1732/**
1733* smack_host_label - check host based restrictions
1734* @sip: the object end
1735*
1736* looks for host based access restrictions
1737*
1738* This version will only be appropriate for really small sets of single label
1739* hosts. The caller is responsible for ensuring that the RCU read lock is
1740* taken before calling this function.
1741*
1742* Returns the label of the far end or NULL if it's not special.
1743*/
1744static char *smack_host_label(struct sockaddr_in *sip)
1745{
1746 struct smk_netlbladdr *snp;
1747 struct in_addr *siap = &sip->sin_addr;
1748
1749 if (siap->s_addr == 0)
1750 return NULL;
1751
1752 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1753 /*
1754 * we break after finding the first match because
1755 * the list is sorted from longest to shortest mask
1756 * so we have found the most specific match
1757 */
1758 if ((&snp->smk_host.sin_addr)->s_addr ==
1759 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1760 /* we have found the special CIPSO option */
1761 if (snp->smk_label == smack_cipso_option)
1762 return NULL;
1763 return snp->smk_label;
1764 }
1765
1766 return NULL;
1767}
1768
1769/**
1770 * smack_set_catset - convert a capset to netlabel mls categories
1771 * @catset: the Smack categories
1772 * @sap: where to put the netlabel categories
1773 *
1774 * Allocates and fills attr.mls.cat
1775 */
1776static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1777{
1778 unsigned char *cp;
1779 unsigned char m;
1780 int cat;
1781 int rc;
1782 int byte;
1783
1784 if (!catset)
1785 return;
1786
1787 sap->flags |= NETLBL_SECATTR_MLS_CAT;
1788 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1789 sap->attr.mls.cat->startbit = 0;
1790
1791 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1792 for (m = 0x80; m != 0; m >>= 1, cat++) {
1793 if ((m & *cp) == 0)
1794 continue;
1795 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1796 cat, GFP_ATOMIC);
1797 }
1798}
1799
1800/**
1801 * smack_to_secattr - fill a secattr from a smack value
1802 * @smack: the smack value
1803 * @nlsp: where the result goes
1804 *
1805 * Casey says that CIPSO is good enough for now.
1806 * It can be used to effect.
1807 * It can also be abused to effect when necessary.
1808 * Apologies to the TSIG group in general and GW in particular.
1809 */
1810static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1811{
1812 struct smack_cipso cipso;
1813 int rc;
1814
1815 nlsp->domain = smack;
1816 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1817
1818 rc = smack_to_cipso(smack, &cipso);
1819 if (rc == 0) {
1820 nlsp->attr.mls.lvl = cipso.smk_level;
1821 smack_set_catset(cipso.smk_catset, nlsp);
1822 } else {
1823 nlsp->attr.mls.lvl = smack_cipso_direct;
1824 smack_set_catset(smack, nlsp);
1825 }
1826}
1827
1828/**
1829 * smack_netlabel - Set the secattr on a socket
1830 * @sk: the socket
1831 * @labeled: socket label scheme
1832 *
1833 * Convert the outbound smack value (smk_out) to a
1834 * secattr and attach it to the socket.
1835 *
1836 * Returns 0 on success or an error code
1837 */
1838static int smack_netlabel(struct sock *sk, int labeled)
1839{
1840 struct socket_smack *ssp = sk->sk_security;
1841 struct netlbl_lsm_secattr secattr;
1842 int rc = 0;
1843
1844 /*
1845 * Usually the netlabel code will handle changing the
1846 * packet labeling based on the label.
1847 * The case of a single label host is different, because
1848 * a single label host should never get a labeled packet
1849 * even though the label is usually associated with a packet
1850 * label.
1851 */
1852 local_bh_disable();
1853 bh_lock_sock_nested(sk);
1854
1855 if (ssp->smk_out == smack_net_ambient ||
1856 labeled == SMACK_UNLABELED_SOCKET)
1857 netlbl_sock_delattr(sk);
1858 else {
1859 netlbl_secattr_init(&secattr);
1860 smack_to_secattr(ssp->smk_out, &secattr);
1861 rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr);
1862 netlbl_secattr_destroy(&secattr);
1863 }
1864
1865 bh_unlock_sock(sk);
1866 local_bh_enable();
1867
1868 return rc;
1869}
1870
1871/**
1872 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1873 * @sk: the socket
1874 * @sap: the destination address
1875 *
1876 * Set the correct secattr for the given socket based on the destination
1877 * address and perform any outbound access checks needed.
1878 *
1879 * Returns 0 on success or an error code.
1880 *
1881 */
1882static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1883{
1884 int rc;
1885 int sk_lbl;
1886 char *hostsp;
1887 struct socket_smack *ssp = sk->sk_security;
1888 struct smk_audit_info ad;
1889
1890 rcu_read_lock();
1891 hostsp = smack_host_label(sap);
1892 if (hostsp != NULL) {
1893 sk_lbl = SMACK_UNLABELED_SOCKET;
1894#ifdef CONFIG_AUDIT
1895 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
1896 ad.a.u.net.family = sap->sin_family;
1897 ad.a.u.net.dport = sap->sin_port;
1898 ad.a.u.net.v4info.daddr = sap->sin_addr.s_addr;
1899#endif
1900 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1901 } else {
1902 sk_lbl = SMACK_CIPSO_SOCKET;
1903 rc = 0;
1904 }
1905 rcu_read_unlock();
1906 if (rc != 0)
1907 return rc;
1908
1909 return smack_netlabel(sk, sk_lbl);
1910}
1911
1912/**
1913 * smack_inode_setsecurity - set smack xattrs
1914 * @inode: the object
1915 * @name: attribute name
1916 * @value: attribute value
1917 * @size: size of the attribute
1918 * @flags: unused
1919 *
1920 * Sets the named attribute in the appropriate blob
1921 *
1922 * Returns 0 on success, or an error code
1923 */
1924static int smack_inode_setsecurity(struct inode *inode, const char *name,
1925 const void *value, size_t size, int flags)
1926{
1927 char *sp;
1928 struct inode_smack *nsp = inode->i_security;
1929 struct socket_smack *ssp;
1930 struct socket *sock;
1931 int rc = 0;
1932
1933 if (value == NULL || size > SMK_LABELLEN || size == 0)
1934 return -EACCES;
1935
1936 sp = smk_import(value, size);
1937 if (sp == NULL)
1938 return -EINVAL;
1939
1940 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1941 nsp->smk_inode = sp;
1942 nsp->smk_flags |= SMK_INODE_INSTANT;
1943 return 0;
1944 }
1945 /*
1946 * The rest of the Smack xattrs are only on sockets.
1947 */
1948 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1949 return -EOPNOTSUPP;
1950
1951 sock = SOCKET_I(inode);
1952 if (sock == NULL || sock->sk == NULL)
1953 return -EOPNOTSUPP;
1954
1955 ssp = sock->sk->sk_security;
1956
1957 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1958 ssp->smk_in = sp;
1959 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1960 ssp->smk_out = sp;
1961 if (sock->sk->sk_family != PF_UNIX) {
1962 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1963 if (rc != 0)
1964 printk(KERN_WARNING
1965 "Smack: \"%s\" netlbl error %d.\n",
1966 __func__, -rc);
1967 }
1968 } else
1969 return -EOPNOTSUPP;
1970
1971 return 0;
1972}
1973
1974/**
1975 * smack_socket_post_create - finish socket setup
1976 * @sock: the socket
1977 * @family: protocol family
1978 * @type: unused
1979 * @protocol: unused
1980 * @kern: unused
1981 *
1982 * Sets the netlabel information on the socket
1983 *
1984 * Returns 0 on success, and error code otherwise
1985 */
1986static int smack_socket_post_create(struct socket *sock, int family,
1987 int type, int protocol, int kern)
1988{
1989 if (family != PF_INET || sock->sk == NULL)
1990 return 0;
1991 /*
1992 * Set the outbound netlbl.
1993 */
1994 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1995}
1996
1997/**
1998 * smack_socket_connect - connect access check
1999 * @sock: the socket
2000 * @sap: the other end
2001 * @addrlen: size of sap
2002 *
2003 * Verifies that a connection may be possible
2004 *
2005 * Returns 0 on success, and error code otherwise
2006 */
2007static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2008 int addrlen)
2009{
2010 if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
2011 return 0;
2012 if (addrlen < sizeof(struct sockaddr_in))
2013 return -EINVAL;
2014
2015 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2016}
2017
2018/**
2019 * smack_flags_to_may - convert S_ to MAY_ values
2020 * @flags: the S_ value
2021 *
2022 * Returns the equivalent MAY_ value
2023 */
2024static int smack_flags_to_may(int flags)
2025{
2026 int may = 0;
2027
2028 if (flags & S_IRUGO)
2029 may |= MAY_READ;
2030 if (flags & S_IWUGO)
2031 may |= MAY_WRITE;
2032 if (flags & S_IXUGO)
2033 may |= MAY_EXEC;
2034
2035 return may;
2036}
2037
2038/**
2039 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2040 * @msg: the object
2041 *
2042 * Returns 0
2043 */
2044static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2045{
2046 msg->security = smk_of_current();
2047 return 0;
2048}
2049
2050/**
2051 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2052 * @msg: the object
2053 *
2054 * Clears the blob pointer
2055 */
2056static void smack_msg_msg_free_security(struct msg_msg *msg)
2057{
2058 msg->security = NULL;
2059}
2060
2061/**
2062 * smack_of_shm - the smack pointer for the shm
2063 * @shp: the object
2064 *
2065 * Returns a pointer to the smack value
2066 */
2067static char *smack_of_shm(struct shmid_kernel *shp)
2068{
2069 return (char *)shp->shm_perm.security;
2070}
2071
2072/**
2073 * smack_shm_alloc_security - Set the security blob for shm
2074 * @shp: the object
2075 *
2076 * Returns 0
2077 */
2078static int smack_shm_alloc_security(struct shmid_kernel *shp)
2079{
2080 struct kern_ipc_perm *isp = &shp->shm_perm;
2081
2082 isp->security = smk_of_current();
2083 return 0;
2084}
2085
2086/**
2087 * smack_shm_free_security - Clear the security blob for shm
2088 * @shp: the object
2089 *
2090 * Clears the blob pointer
2091 */
2092static void smack_shm_free_security(struct shmid_kernel *shp)
2093{
2094 struct kern_ipc_perm *isp = &shp->shm_perm;
2095
2096 isp->security = NULL;
2097}
2098
2099/**
2100 * smk_curacc_shm : check if current has access on shm
2101 * @shp : the object
2102 * @access : access requested
2103 *
2104 * Returns 0 if current has the requested access, error code otherwise
2105 */
2106static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2107{
2108 char *ssp = smack_of_shm(shp);
2109 struct smk_audit_info ad;
2110
2111#ifdef CONFIG_AUDIT
2112 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2113 ad.a.u.ipc_id = shp->shm_perm.id;
2114#endif
2115 return smk_curacc(ssp, access, &ad);
2116}
2117
2118/**
2119 * smack_shm_associate - Smack access check for shm
2120 * @shp: the object
2121 * @shmflg: access requested
2122 *
2123 * Returns 0 if current has the requested access, error code otherwise
2124 */
2125static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2126{
2127 int may;
2128
2129 may = smack_flags_to_may(shmflg);
2130 return smk_curacc_shm(shp, may);
2131}
2132
2133/**
2134 * smack_shm_shmctl - Smack access check for shm
2135 * @shp: the object
2136 * @cmd: what it wants to do
2137 *
2138 * Returns 0 if current has the requested access, error code otherwise
2139 */
2140static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2141{
2142 int may;
2143
2144 switch (cmd) {
2145 case IPC_STAT:
2146 case SHM_STAT:
2147 may = MAY_READ;
2148 break;
2149 case IPC_SET:
2150 case SHM_LOCK:
2151 case SHM_UNLOCK:
2152 case IPC_RMID:
2153 may = MAY_READWRITE;
2154 break;
2155 case IPC_INFO:
2156 case SHM_INFO:
2157 /*
2158 * System level information.
2159 */
2160 return 0;
2161 default:
2162 return -EINVAL;
2163 }
2164 return smk_curacc_shm(shp, may);
2165}
2166
2167/**
2168 * smack_shm_shmat - Smack access for shmat
2169 * @shp: the object
2170 * @shmaddr: unused
2171 * @shmflg: access requested
2172 *
2173 * Returns 0 if current has the requested access, error code otherwise
2174 */
2175static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2176 int shmflg)
2177{
2178 int may;
2179
2180 may = smack_flags_to_may(shmflg);
2181 return smk_curacc_shm(shp, may);
2182}
2183
2184/**
2185 * smack_of_sem - the smack pointer for the sem
2186 * @sma: the object
2187 *
2188 * Returns a pointer to the smack value
2189 */
2190static char *smack_of_sem(struct sem_array *sma)
2191{
2192 return (char *)sma->sem_perm.security;
2193}
2194
2195/**
2196 * smack_sem_alloc_security - Set the security blob for sem
2197 * @sma: the object
2198 *
2199 * Returns 0
2200 */
2201static int smack_sem_alloc_security(struct sem_array *sma)
2202{
2203 struct kern_ipc_perm *isp = &sma->sem_perm;
2204
2205 isp->security = smk_of_current();
2206 return 0;
2207}
2208
2209/**
2210 * smack_sem_free_security - Clear the security blob for sem
2211 * @sma: the object
2212 *
2213 * Clears the blob pointer
2214 */
2215static void smack_sem_free_security(struct sem_array *sma)
2216{
2217 struct kern_ipc_perm *isp = &sma->sem_perm;
2218
2219 isp->security = NULL;
2220}
2221
2222/**
2223 * smk_curacc_sem : check if current has access on sem
2224 * @sma : the object
2225 * @access : access requested
2226 *
2227 * Returns 0 if current has the requested access, error code otherwise
2228 */
2229static int smk_curacc_sem(struct sem_array *sma, int access)
2230{
2231 char *ssp = smack_of_sem(sma);
2232 struct smk_audit_info ad;
2233
2234#ifdef CONFIG_AUDIT
2235 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2236 ad.a.u.ipc_id = sma->sem_perm.id;
2237#endif
2238 return smk_curacc(ssp, access, &ad);
2239}
2240
2241/**
2242 * smack_sem_associate - Smack access check for sem
2243 * @sma: the object
2244 * @semflg: access requested
2245 *
2246 * Returns 0 if current has the requested access, error code otherwise
2247 */
2248static int smack_sem_associate(struct sem_array *sma, int semflg)
2249{
2250 int may;
2251
2252 may = smack_flags_to_may(semflg);
2253 return smk_curacc_sem(sma, may);
2254}
2255
2256/**
2257 * smack_sem_shmctl - Smack access check for sem
2258 * @sma: the object
2259 * @cmd: what it wants to do
2260 *
2261 * Returns 0 if current has the requested access, error code otherwise
2262 */
2263static int smack_sem_semctl(struct sem_array *sma, int cmd)
2264{
2265 int may;
2266
2267 switch (cmd) {
2268 case GETPID:
2269 case GETNCNT:
2270 case GETZCNT:
2271 case GETVAL:
2272 case GETALL:
2273 case IPC_STAT:
2274 case SEM_STAT:
2275 may = MAY_READ;
2276 break;
2277 case SETVAL:
2278 case SETALL:
2279 case IPC_RMID:
2280 case IPC_SET:
2281 may = MAY_READWRITE;
2282 break;
2283 case IPC_INFO:
2284 case SEM_INFO:
2285 /*
2286 * System level information
2287 */
2288 return 0;
2289 default:
2290 return -EINVAL;
2291 }
2292
2293 return smk_curacc_sem(sma, may);
2294}
2295
2296/**
2297 * smack_sem_semop - Smack checks of semaphore operations
2298 * @sma: the object
2299 * @sops: unused
2300 * @nsops: unused
2301 * @alter: unused
2302 *
2303 * Treated as read and write in all cases.
2304 *
2305 * Returns 0 if access is allowed, error code otherwise
2306 */
2307static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2308 unsigned nsops, int alter)
2309{
2310 return smk_curacc_sem(sma, MAY_READWRITE);
2311}
2312
2313/**
2314 * smack_msg_alloc_security - Set the security blob for msg
2315 * @msq: the object
2316 *
2317 * Returns 0
2318 */
2319static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2320{
2321 struct kern_ipc_perm *kisp = &msq->q_perm;
2322
2323 kisp->security = smk_of_current();
2324 return 0;
2325}
2326
2327/**
2328 * smack_msg_free_security - Clear the security blob for msg
2329 * @msq: the object
2330 *
2331 * Clears the blob pointer
2332 */
2333static void smack_msg_queue_free_security(struct msg_queue *msq)
2334{
2335 struct kern_ipc_perm *kisp = &msq->q_perm;
2336
2337 kisp->security = NULL;
2338}
2339
2340/**
2341 * smack_of_msq - the smack pointer for the msq
2342 * @msq: the object
2343 *
2344 * Returns a pointer to the smack value
2345 */
2346static char *smack_of_msq(struct msg_queue *msq)
2347{
2348 return (char *)msq->q_perm.security;
2349}
2350
2351/**
2352 * smk_curacc_msq : helper to check if current has access on msq
2353 * @msq : the msq
2354 * @access : access requested
2355 *
2356 * return 0 if current has access, error otherwise
2357 */
2358static int smk_curacc_msq(struct msg_queue *msq, int access)
2359{
2360 char *msp = smack_of_msq(msq);
2361 struct smk_audit_info ad;
2362
2363#ifdef CONFIG_AUDIT
2364 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2365 ad.a.u.ipc_id = msq->q_perm.id;
2366#endif
2367 return smk_curacc(msp, access, &ad);
2368}
2369
2370/**
2371 * smack_msg_queue_associate - Smack access check for msg_queue
2372 * @msq: the object
2373 * @msqflg: access requested
2374 *
2375 * Returns 0 if current has the requested access, error code otherwise
2376 */
2377static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2378{
2379 int may;
2380
2381 may = smack_flags_to_may(msqflg);
2382 return smk_curacc_msq(msq, may);
2383}
2384
2385/**
2386 * smack_msg_queue_msgctl - Smack access check for msg_queue
2387 * @msq: the object
2388 * @cmd: what it wants to do
2389 *
2390 * Returns 0 if current has the requested access, error code otherwise
2391 */
2392static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2393{
2394 int may;
2395
2396 switch (cmd) {
2397 case IPC_STAT:
2398 case MSG_STAT:
2399 may = MAY_READ;
2400 break;
2401 case IPC_SET:
2402 case IPC_RMID:
2403 may = MAY_READWRITE;
2404 break;
2405 case IPC_INFO:
2406 case MSG_INFO:
2407 /*
2408 * System level information
2409 */
2410 return 0;
2411 default:
2412 return -EINVAL;
2413 }
2414
2415 return smk_curacc_msq(msq, may);
2416}
2417
2418/**
2419 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2420 * @msq: the object
2421 * @msg: unused
2422 * @msqflg: access requested
2423 *
2424 * Returns 0 if current has the requested access, error code otherwise
2425 */
2426static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2427 int msqflg)
2428{
2429 int may;
2430
2431 may = smack_flags_to_may(msqflg);
2432 return smk_curacc_msq(msq, may);
2433}
2434
2435/**
2436 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2437 * @msq: the object
2438 * @msg: unused
2439 * @target: unused
2440 * @type: unused
2441 * @mode: unused
2442 *
2443 * Returns 0 if current has read and write access, error code otherwise
2444 */
2445static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2446 struct task_struct *target, long type, int mode)
2447{
2448 return smk_curacc_msq(msq, MAY_READWRITE);
2449}
2450
2451/**
2452 * smack_ipc_permission - Smack access for ipc_permission()
2453 * @ipp: the object permissions
2454 * @flag: access requested
2455 *
2456 * Returns 0 if current has read and write access, error code otherwise
2457 */
2458static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2459{
2460 char *isp = ipp->security;
2461 int may = smack_flags_to_may(flag);
2462 struct smk_audit_info ad;
2463
2464#ifdef CONFIG_AUDIT
2465 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2466 ad.a.u.ipc_id = ipp->id;
2467#endif
2468 return smk_curacc(isp, may, &ad);
2469}
2470
2471/**
2472 * smack_ipc_getsecid - Extract smack security id
2473 * @ipp: the object permissions
2474 * @secid: where result will be saved
2475 */
2476static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2477{
2478 char *smack = ipp->security;
2479
2480 *secid = smack_to_secid(smack);
2481}
2482
2483/**
2484 * smack_d_instantiate - Make sure the blob is correct on an inode
2485 * @opt_dentry: dentry where inode will be attached
2486 * @inode: the object
2487 *
2488 * Set the inode's security blob if it hasn't been done already.
2489 */
2490static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2491{
2492 struct super_block *sbp;
2493 struct superblock_smack *sbsp;
2494 struct inode_smack *isp;
2495 char *csp = smk_of_current();
2496 char *fetched;
2497 char *final;
2498 char trattr[TRANS_TRUE_SIZE];
2499 int transflag = 0;
2500 struct dentry *dp;
2501
2502 if (inode == NULL)
2503 return;
2504
2505 isp = inode->i_security;
2506
2507 mutex_lock(&isp->smk_lock);
2508 /*
2509 * If the inode is already instantiated
2510 * take the quick way out
2511 */
2512 if (isp->smk_flags & SMK_INODE_INSTANT)
2513 goto unlockandout;
2514
2515 sbp = inode->i_sb;
2516 sbsp = sbp->s_security;
2517 /*
2518 * We're going to use the superblock default label
2519 * if there's no label on the file.
2520 */
2521 final = sbsp->smk_default;
2522
2523 /*
2524 * If this is the root inode the superblock
2525 * may be in the process of initialization.
2526 * If that is the case use the root value out
2527 * of the superblock.
2528 */
2529 if (opt_dentry->d_parent == opt_dentry) {
2530 isp->smk_inode = sbsp->smk_root;
2531 isp->smk_flags |= SMK_INODE_INSTANT;
2532 goto unlockandout;
2533 }
2534
2535 /*
2536 * This is pretty hackish.
2537 * Casey says that we shouldn't have to do
2538 * file system specific code, but it does help
2539 * with keeping it simple.
2540 */
2541 switch (sbp->s_magic) {
2542 case SMACK_MAGIC:
2543 /*
2544 * Casey says that it's a little embarrassing
2545 * that the smack file system doesn't do
2546 * extended attributes.
2547 */
2548 final = smack_known_star.smk_known;
2549 break;
2550 case PIPEFS_MAGIC:
2551 /*
2552 * Casey says pipes are easy (?)
2553 */
2554 final = smack_known_star.smk_known;
2555 break;
2556 case DEVPTS_SUPER_MAGIC:
2557 /*
2558 * devpts seems content with the label of the task.
2559 * Programs that change smack have to treat the
2560 * pty with respect.
2561 */
2562 final = csp;
2563 break;
2564 case SOCKFS_MAGIC:
2565 /*
2566 * Socket access is controlled by the socket
2567 * structures associated with the task involved.
2568 */
2569 final = smack_known_star.smk_known;
2570 break;
2571 case PROC_SUPER_MAGIC:
2572 /*
2573 * Casey says procfs appears not to care.
2574 * The superblock default suffices.
2575 */
2576 break;
2577 case TMPFS_MAGIC:
2578 /*
2579 * Device labels should come from the filesystem,
2580 * but watch out, because they're volitile,
2581 * getting recreated on every reboot.
2582 */
2583 final = smack_known_star.smk_known;
2584 /*
2585 * No break.
2586 *
2587 * If a smack value has been set we want to use it,
2588 * but since tmpfs isn't giving us the opportunity
2589 * to set mount options simulate setting the
2590 * superblock default.
2591 */
2592 default:
2593 /*
2594 * This isn't an understood special case.
2595 * Get the value from the xattr.
2596 */
2597
2598 /*
2599 * UNIX domain sockets use lower level socket data.
2600 */
2601 if (S_ISSOCK(inode->i_mode)) {
2602 final = smack_known_star.smk_known;
2603 break;
2604 }
2605 /*
2606 * No xattr support means, alas, no SMACK label.
2607 * Use the aforeapplied default.
2608 * It would be curious if the label of the task
2609 * does not match that assigned.
2610 */
2611 if (inode->i_op->getxattr == NULL)
2612 break;
2613 /*
2614 * Get the dentry for xattr.
2615 */
2616 dp = dget(opt_dentry);
2617 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2618 if (fetched != NULL) {
2619 final = fetched;
2620 if (S_ISDIR(inode->i_mode)) {
2621 trattr[0] = '\0';
2622 inode->i_op->getxattr(dp,
2623 XATTR_NAME_SMACKTRANSMUTE,
2624 trattr, TRANS_TRUE_SIZE);
2625 if (strncmp(trattr, TRANS_TRUE,
2626 TRANS_TRUE_SIZE) == 0)
2627 transflag = SMK_INODE_TRANSMUTE;
2628 }
2629 }
2630 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2631 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2632
2633 dput(dp);
2634 break;
2635 }
2636
2637 if (final == NULL)
2638 isp->smk_inode = csp;
2639 else
2640 isp->smk_inode = final;
2641
2642 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2643
2644unlockandout:
2645 mutex_unlock(&isp->smk_lock);
2646 return;
2647}
2648
2649/**
2650 * smack_getprocattr - Smack process attribute access
2651 * @p: the object task
2652 * @name: the name of the attribute in /proc/.../attr
2653 * @value: where to put the result
2654 *
2655 * Places a copy of the task Smack into value
2656 *
2657 * Returns the length of the smack label or an error code
2658 */
2659static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2660{
2661 char *cp;
2662 int slen;
2663
2664 if (strcmp(name, "current") != 0)
2665 return -EINVAL;
2666
2667 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2668 if (cp == NULL)
2669 return -ENOMEM;
2670
2671 slen = strlen(cp);
2672 *value = cp;
2673 return slen;
2674}
2675
2676/**
2677 * smack_setprocattr - Smack process attribute setting
2678 * @p: the object task
2679 * @name: the name of the attribute in /proc/.../attr
2680 * @value: the value to set
2681 * @size: the size of the value
2682 *
2683 * Sets the Smack value of the task. Only setting self
2684 * is permitted and only with privilege
2685 *
2686 * Returns the length of the smack label or an error code
2687 */
2688static int smack_setprocattr(struct task_struct *p, char *name,
2689 void *value, size_t size)
2690{
2691 int rc;
2692 struct task_smack *tsp;
2693 struct task_smack *oldtsp;
2694 struct cred *new;
2695 char *newsmack;
2696
2697 /*
2698 * Changing another process' Smack value is too dangerous
2699 * and supports no sane use case.
2700 */
2701 if (p != current)
2702 return -EPERM;
2703
2704 if (!capable(CAP_MAC_ADMIN))
2705 return -EPERM;
2706
2707 if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2708 return -EINVAL;
2709
2710 if (strcmp(name, "current") != 0)
2711 return -EINVAL;
2712
2713 newsmack = smk_import(value, size);
2714 if (newsmack == NULL)
2715 return -EINVAL;
2716
2717 /*
2718 * No process is ever allowed the web ("@") label.
2719 */
2720 if (newsmack == smack_known_web.smk_known)
2721 return -EPERM;
2722
2723 oldtsp = p->cred->security;
2724 new = prepare_creds();
2725 if (new == NULL)
2726 return -ENOMEM;
2727
2728 tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
2729 if (tsp == NULL) {
2730 kfree(new);
2731 return -ENOMEM;
2732 }
2733 rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
2734 if (rc != 0)
2735 return rc;
2736
2737 new->security = tsp;
2738 commit_creds(new);
2739 return size;
2740}
2741
2742/**
2743 * smack_unix_stream_connect - Smack access on UDS
2744 * @sock: one sock
2745 * @other: the other sock
2746 * @newsk: unused
2747 *
2748 * Return 0 if a subject with the smack of sock could access
2749 * an object with the smack of other, otherwise an error code
2750 */
2751static int smack_unix_stream_connect(struct sock *sock,
2752 struct sock *other, struct sock *newsk)
2753{
2754 struct socket_smack *ssp = sock->sk_security;
2755 struct socket_smack *osp = other->sk_security;
2756 struct smk_audit_info ad;
2757 int rc = 0;
2758
2759 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2760 smk_ad_setfield_u_net_sk(&ad, other);
2761
2762 if (!capable(CAP_MAC_OVERRIDE))
2763 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2764
2765 return rc;
2766}
2767
2768/**
2769 * smack_unix_may_send - Smack access on UDS
2770 * @sock: one socket
2771 * @other: the other socket
2772 *
2773 * Return 0 if a subject with the smack of sock could access
2774 * an object with the smack of other, otherwise an error code
2775 */
2776static int smack_unix_may_send(struct socket *sock, struct socket *other)
2777{
2778 struct socket_smack *ssp = sock->sk->sk_security;
2779 struct socket_smack *osp = other->sk->sk_security;
2780 struct smk_audit_info ad;
2781 int rc = 0;
2782
2783 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2784 smk_ad_setfield_u_net_sk(&ad, other->sk);
2785
2786 if (!capable(CAP_MAC_OVERRIDE))
2787 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2788
2789 return rc;
2790}
2791
2792/**
2793 * smack_socket_sendmsg - Smack check based on destination host
2794 * @sock: the socket
2795 * @msg: the message
2796 * @size: the size of the message
2797 *
2798 * Return 0 if the current subject can write to the destination
2799 * host. This is only a question if the destination is a single
2800 * label host.
2801 */
2802static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2803 int size)
2804{
2805 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2806
2807 /*
2808 * Perfectly reasonable for this to be NULL
2809 */
2810 if (sip == NULL || sip->sin_family != AF_INET)
2811 return 0;
2812
2813 return smack_netlabel_send(sock->sk, sip);
2814}
2815
2816
2817/**
2818 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2819 * @sap: netlabel secattr
2820 * @sip: where to put the result
2821 *
2822 * Copies a smack label into sip
2823 */
2824static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2825{
2826 char smack[SMK_LABELLEN];
2827 char *sp;
2828 int pcat;
2829
2830 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2831 /*
2832 * Looks like a CIPSO packet.
2833 * If there are flags but no level netlabel isn't
2834 * behaving the way we expect it to.
2835 *
2836 * Get the categories, if any
2837 * Without guidance regarding the smack value
2838 * for the packet fall back on the network
2839 * ambient value.
2840 */
2841 memset(smack, '\0', SMK_LABELLEN);
2842 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2843 for (pcat = -1;;) {
2844 pcat = netlbl_secattr_catmap_walk(
2845 sap->attr.mls.cat, pcat + 1);
2846 if (pcat < 0)
2847 break;
2848 smack_catset_bit(pcat, smack);
2849 }
2850 /*
2851 * If it is CIPSO using smack direct mapping
2852 * we are already done. WeeHee.
2853 */
2854 if (sap->attr.mls.lvl == smack_cipso_direct) {
2855 memcpy(sip, smack, SMK_MAXLEN);
2856 return;
2857 }
2858 /*
2859 * Look it up in the supplied table if it is not
2860 * a direct mapping.
2861 */
2862 smack_from_cipso(sap->attr.mls.lvl, smack, sip);
2863 return;
2864 }
2865 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2866 /*
2867 * Looks like a fallback, which gives us a secid.
2868 */
2869 sp = smack_from_secid(sap->attr.secid);
2870 /*
2871 * This has got to be a bug because it is
2872 * impossible to specify a fallback without
2873 * specifying the label, which will ensure
2874 * it has a secid, and the only way to get a
2875 * secid is from a fallback.
2876 */
2877 BUG_ON(sp == NULL);
2878 strncpy(sip, sp, SMK_MAXLEN);
2879 return;
2880 }
2881 /*
2882 * Without guidance regarding the smack value
2883 * for the packet fall back on the network
2884 * ambient value.
2885 */
2886 strncpy(sip, smack_net_ambient, SMK_MAXLEN);
2887 return;
2888}
2889
2890/**
2891 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2892 * @sk: socket
2893 * @skb: packet
2894 *
2895 * Returns 0 if the packet should be delivered, an error code otherwise
2896 */
2897static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2898{
2899 struct netlbl_lsm_secattr secattr;
2900 struct socket_smack *ssp = sk->sk_security;
2901 char smack[SMK_LABELLEN];
2902 char *csp;
2903 int rc;
2904 struct smk_audit_info ad;
2905 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2906 return 0;
2907
2908 /*
2909 * Translate what netlabel gave us.
2910 */
2911 netlbl_secattr_init(&secattr);
2912
2913 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2914 if (rc == 0) {
2915 smack_from_secattr(&secattr, smack);
2916 csp = smack;
2917 } else
2918 csp = smack_net_ambient;
2919
2920 netlbl_secattr_destroy(&secattr);
2921
2922#ifdef CONFIG_AUDIT
2923 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2924 ad.a.u.net.family = sk->sk_family;
2925 ad.a.u.net.netif = skb->skb_iif;
2926 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2927#endif
2928 /*
2929 * Receiving a packet requires that the other end
2930 * be able to write here. Read access is not required.
2931 * This is the simplist possible security model
2932 * for networking.
2933 */
2934 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2935 if (rc != 0)
2936 netlbl_skbuff_err(skb, rc, 0);
2937 return rc;
2938}
2939
2940/**
2941 * smack_socket_getpeersec_stream - pull in packet label
2942 * @sock: the socket
2943 * @optval: user's destination
2944 * @optlen: size thereof
2945 * @len: max thereof
2946 *
2947 * returns zero on success, an error code otherwise
2948 */
2949static int smack_socket_getpeersec_stream(struct socket *sock,
2950 char __user *optval,
2951 int __user *optlen, unsigned len)
2952{
2953 struct socket_smack *ssp;
2954 int slen;
2955 int rc = 0;
2956
2957 ssp = sock->sk->sk_security;
2958 slen = strlen(ssp->smk_packet) + 1;
2959
2960 if (slen > len)
2961 rc = -ERANGE;
2962 else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2963 rc = -EFAULT;
2964
2965 if (put_user(slen, optlen) != 0)
2966 rc = -EFAULT;
2967
2968 return rc;
2969}
2970
2971
2972/**
2973 * smack_socket_getpeersec_dgram - pull in packet label
2974 * @sock: the peer socket
2975 * @skb: packet data
2976 * @secid: pointer to where to put the secid of the packet
2977 *
2978 * Sets the netlabel socket state on sk from parent
2979 */
2980static int smack_socket_getpeersec_dgram(struct socket *sock,
2981 struct sk_buff *skb, u32 *secid)
2982
2983{
2984 struct netlbl_lsm_secattr secattr;
2985 struct socket_smack *sp;
2986 char smack[SMK_LABELLEN];
2987 int family = PF_UNSPEC;
2988 u32 s = 0; /* 0 is the invalid secid */
2989 int rc;
2990
2991 if (skb != NULL) {
2992 if (skb->protocol == htons(ETH_P_IP))
2993 family = PF_INET;
2994 else if (skb->protocol == htons(ETH_P_IPV6))
2995 family = PF_INET6;
2996 }
2997 if (family == PF_UNSPEC && sock != NULL)
2998 family = sock->sk->sk_family;
2999
3000 if (family == PF_UNIX) {
3001 sp = sock->sk->sk_security;
3002 s = smack_to_secid(sp->smk_out);
3003 } else if (family == PF_INET || family == PF_INET6) {
3004 /*
3005 * Translate what netlabel gave us.
3006 */
3007 netlbl_secattr_init(&secattr);
3008 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3009 if (rc == 0) {
3010 smack_from_secattr(&secattr, smack);
3011 s = smack_to_secid(smack);
3012 }
3013 netlbl_secattr_destroy(&secattr);
3014 }
3015 *secid = s;
3016 if (s == 0)
3017 return -EINVAL;
3018 return 0;
3019}
3020
3021/**
3022 * smack_sock_graft - Initialize a newly created socket with an existing sock
3023 * @sk: child sock
3024 * @parent: parent socket
3025 *
3026 * Set the smk_{in,out} state of an existing sock based on the process that
3027 * is creating the new socket.
3028 */
3029static void smack_sock_graft(struct sock *sk, struct socket *parent)
3030{
3031 struct socket_smack *ssp;
3032
3033 if (sk == NULL ||
3034 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3035 return;
3036
3037 ssp = sk->sk_security;
3038 ssp->smk_in = ssp->smk_out = smk_of_current();
3039 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3040}
3041
3042/**
3043 * smack_inet_conn_request - Smack access check on connect
3044 * @sk: socket involved
3045 * @skb: packet
3046 * @req: unused
3047 *
3048 * Returns 0 if a task with the packet label could write to
3049 * the socket, otherwise an error code
3050 */
3051static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3052 struct request_sock *req)
3053{
3054 u16 family = sk->sk_family;
3055 struct socket_smack *ssp = sk->sk_security;
3056 struct netlbl_lsm_secattr secattr;
3057 struct sockaddr_in addr;
3058 struct iphdr *hdr;
3059 char smack[SMK_LABELLEN];
3060 int rc;
3061 struct smk_audit_info ad;
3062
3063 /* handle mapped IPv4 packets arriving via IPv6 sockets */
3064 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3065 family = PF_INET;
3066
3067 netlbl_secattr_init(&secattr);
3068 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3069 if (rc == 0)
3070 smack_from_secattr(&secattr, smack);
3071 else
3072 strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
3073 netlbl_secattr_destroy(&secattr);
3074
3075#ifdef CONFIG_AUDIT
3076 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
3077 ad.a.u.net.family = family;
3078 ad.a.u.net.netif = skb->skb_iif;
3079 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3080#endif
3081 /*
3082 * Receiving a packet requires that the other end be able to write
3083 * here. Read access is not required.
3084 */
3085 rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
3086 if (rc != 0)
3087 return rc;
3088
3089 /*
3090 * Save the peer's label in the request_sock so we can later setup
3091 * smk_packet in the child socket so that SO_PEERCRED can report it.
3092 */
3093 req->peer_secid = smack_to_secid(smack);
3094
3095 /*
3096 * We need to decide if we want to label the incoming connection here
3097 * if we do we only need to label the request_sock and the stack will
3098 * propagate the wire-label to the sock when it is created.
3099 */
3100 hdr = ip_hdr(skb);
3101 addr.sin_addr.s_addr = hdr->saddr;
3102 rcu_read_lock();
3103 if (smack_host_label(&addr) == NULL) {
3104 rcu_read_unlock();
3105 netlbl_secattr_init(&secattr);
3106 smack_to_secattr(smack, &secattr);
3107 rc = netlbl_req_setattr(req, &secattr);
3108 netlbl_secattr_destroy(&secattr);
3109 } else {
3110 rcu_read_unlock();
3111 netlbl_req_delattr(req);
3112 }
3113
3114 return rc;
3115}
3116
3117/**
3118 * smack_inet_csk_clone - Copy the connection information to the new socket
3119 * @sk: the new socket
3120 * @req: the connection's request_sock
3121 *
3122 * Transfer the connection's peer label to the newly created socket.
3123 */
3124static void smack_inet_csk_clone(struct sock *sk,
3125 const struct request_sock *req)
3126{
3127 struct socket_smack *ssp = sk->sk_security;
3128 char *smack;
3129
3130 if (req->peer_secid != 0) {
3131 smack = smack_from_secid(req->peer_secid);
3132 strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
3133 } else
3134 ssp->smk_packet[0] = '\0';
3135}
3136
3137/*
3138 * Key management security hooks
3139 *
3140 * Casey has not tested key support very heavily.
3141 * The permission check is most likely too restrictive.
3142 * If you care about keys please have a look.
3143 */
3144#ifdef CONFIG_KEYS
3145
3146/**
3147 * smack_key_alloc - Set the key security blob
3148 * @key: object
3149 * @cred: the credentials to use
3150 * @flags: unused
3151 *
3152 * No allocation required
3153 *
3154 * Returns 0
3155 */
3156static int smack_key_alloc(struct key *key, const struct cred *cred,
3157 unsigned long flags)
3158{
3159 key->security = smk_of_task(cred->security);
3160 return 0;
3161}
3162
3163/**
3164 * smack_key_free - Clear the key security blob
3165 * @key: the object
3166 *
3167 * Clear the blob pointer
3168 */
3169static void smack_key_free(struct key *key)
3170{
3171 key->security = NULL;
3172}
3173
3174/*
3175 * smack_key_permission - Smack access on a key
3176 * @key_ref: gets to the object
3177 * @cred: the credentials to use
3178 * @perm: unused
3179 *
3180 * Return 0 if the task has read and write to the object,
3181 * an error code otherwise
3182 */
3183static int smack_key_permission(key_ref_t key_ref,
3184 const struct cred *cred, key_perm_t perm)
3185{
3186 struct key *keyp;
3187 struct smk_audit_info ad;
3188 char *tsp = smk_of_task(cred->security);
3189
3190 keyp = key_ref_to_ptr(key_ref);
3191 if (keyp == NULL)
3192 return -EINVAL;
3193 /*
3194 * If the key hasn't been initialized give it access so that
3195 * it may do so.
3196 */
3197 if (keyp->security == NULL)
3198 return 0;
3199 /*
3200 * This should not occur
3201 */
3202 if (tsp == NULL)
3203 return -EACCES;
3204#ifdef CONFIG_AUDIT
3205 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3206 ad.a.u.key_struct.key = keyp->serial;
3207 ad.a.u.key_struct.key_desc = keyp->description;
3208#endif
3209 return smk_access(tsp, keyp->security,
3210 MAY_READWRITE, &ad);
3211}
3212#endif /* CONFIG_KEYS */
3213
3214/*
3215 * Smack Audit hooks
3216 *
3217 * Audit requires a unique representation of each Smack specific
3218 * rule. This unique representation is used to distinguish the
3219 * object to be audited from remaining kernel objects and also
3220 * works as a glue between the audit hooks.
3221 *
3222 * Since repository entries are added but never deleted, we'll use
3223 * the smack_known label address related to the given audit rule as
3224 * the needed unique representation. This also better fits the smack
3225 * model where nearly everything is a label.
3226 */
3227#ifdef CONFIG_AUDIT
3228
3229/**
3230 * smack_audit_rule_init - Initialize a smack audit rule
3231 * @field: audit rule fields given from user-space (audit.h)
3232 * @op: required testing operator (=, !=, >, <, ...)
3233 * @rulestr: smack label to be audited
3234 * @vrule: pointer to save our own audit rule representation
3235 *
3236 * Prepare to audit cases where (@field @op @rulestr) is true.
3237 * The label to be audited is created if necessay.
3238 */
3239static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3240{
3241 char **rule = (char **)vrule;
3242 *rule = NULL;
3243
3244 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3245 return -EINVAL;
3246
3247 if (op != Audit_equal && op != Audit_not_equal)
3248 return -EINVAL;
3249
3250 *rule = smk_import(rulestr, 0);
3251
3252 return 0;
3253}
3254
3255/**
3256 * smack_audit_rule_known - Distinguish Smack audit rules
3257 * @krule: rule of interest, in Audit kernel representation format
3258 *
3259 * This is used to filter Smack rules from remaining Audit ones.
3260 * If it's proved that this rule belongs to us, the
3261 * audit_rule_match hook will be called to do the final judgement.
3262 */
3263static int smack_audit_rule_known(struct audit_krule *krule)
3264{
3265 struct audit_field *f;
3266 int i;
3267
3268 for (i = 0; i < krule->field_count; i++) {
3269 f = &krule->fields[i];
3270
3271 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3272 return 1;
3273 }
3274
3275 return 0;
3276}
3277
3278/**
3279 * smack_audit_rule_match - Audit given object ?
3280 * @secid: security id for identifying the object to test
3281 * @field: audit rule flags given from user-space
3282 * @op: required testing operator
3283 * @vrule: smack internal rule presentation
3284 * @actx: audit context associated with the check
3285 *
3286 * The core Audit hook. It's used to take the decision of
3287 * whether to audit or not to audit a given object.
3288 */
3289static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3290 struct audit_context *actx)
3291{
3292 char *smack;
3293 char *rule = vrule;
3294
3295 if (!rule) {
3296 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
3297 "Smack: missing rule\n");
3298 return -ENOENT;
3299 }
3300
3301 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3302 return 0;
3303
3304 smack = smack_from_secid(secid);
3305
3306 /*
3307 * No need to do string comparisons. If a match occurs,
3308 * both pointers will point to the same smack_known
3309 * label.
3310 */
3311 if (op == Audit_equal)
3312 return (rule == smack);
3313 if (op == Audit_not_equal)
3314 return (rule != smack);
3315
3316 return 0;
3317}
3318
3319/**
3320 * smack_audit_rule_free - free smack rule representation
3321 * @vrule: rule to be freed.
3322 *
3323 * No memory was allocated.
3324 */
3325static void smack_audit_rule_free(void *vrule)
3326{
3327 /* No-op */
3328}
3329
3330#endif /* CONFIG_AUDIT */
3331
3332/**
3333 * smack_secid_to_secctx - return the smack label for a secid
3334 * @secid: incoming integer
3335 * @secdata: destination
3336 * @seclen: how long it is
3337 *
3338 * Exists for networking code.
3339 */
3340static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3341{
3342 char *sp = smack_from_secid(secid);
3343
3344 if (secdata)
3345 *secdata = sp;
3346 *seclen = strlen(sp);
3347 return 0;
3348}
3349
3350/**
3351 * smack_secctx_to_secid - return the secid for a smack label
3352 * @secdata: smack label
3353 * @seclen: how long result is
3354 * @secid: outgoing integer
3355 *
3356 * Exists for audit and networking code.
3357 */
3358static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3359{
3360 *secid = smack_to_secid(secdata);
3361 return 0;
3362}
3363
3364/**
3365 * smack_release_secctx - don't do anything.
3366 * @secdata: unused
3367 * @seclen: unused
3368 *
3369 * Exists to make sure nothing gets done, and properly
3370 */
3371static void smack_release_secctx(char *secdata, u32 seclen)
3372{
3373}
3374
3375static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3376{
3377 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3378}
3379
3380static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3381{
3382 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3383}
3384
3385static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3386{
3387 int len = 0;
3388 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3389
3390 if (len < 0)
3391 return len;
3392 *ctxlen = len;
3393 return 0;
3394}
3395
3396struct security_operations smack_ops = {
3397 .name = "smack",
3398
3399 .ptrace_access_check = smack_ptrace_access_check,
3400 .ptrace_traceme = smack_ptrace_traceme,
3401 .syslog = smack_syslog,
3402
3403 .sb_alloc_security = smack_sb_alloc_security,
3404 .sb_free_security = smack_sb_free_security,
3405 .sb_copy_data = smack_sb_copy_data,
3406 .sb_kern_mount = smack_sb_kern_mount,
3407 .sb_statfs = smack_sb_statfs,
3408 .sb_mount = smack_sb_mount,
3409 .sb_umount = smack_sb_umount,
3410
3411 .bprm_set_creds = smack_bprm_set_creds,
3412
3413 .inode_alloc_security = smack_inode_alloc_security,
3414 .inode_free_security = smack_inode_free_security,
3415 .inode_init_security = smack_inode_init_security,
3416 .inode_link = smack_inode_link,
3417 .inode_unlink = smack_inode_unlink,
3418 .inode_rmdir = smack_inode_rmdir,
3419 .inode_rename = smack_inode_rename,
3420 .inode_permission = smack_inode_permission,
3421 .inode_setattr = smack_inode_setattr,
3422 .inode_getattr = smack_inode_getattr,
3423 .inode_setxattr = smack_inode_setxattr,
3424 .inode_post_setxattr = smack_inode_post_setxattr,
3425 .inode_getxattr = smack_inode_getxattr,
3426 .inode_removexattr = smack_inode_removexattr,
3427 .inode_getsecurity = smack_inode_getsecurity,
3428 .inode_setsecurity = smack_inode_setsecurity,
3429 .inode_listsecurity = smack_inode_listsecurity,
3430 .inode_getsecid = smack_inode_getsecid,
3431
3432 .file_permission = smack_file_permission,
3433 .file_alloc_security = smack_file_alloc_security,
3434 .file_free_security = smack_file_free_security,
3435 .file_ioctl = smack_file_ioctl,
3436 .file_lock = smack_file_lock,
3437 .file_fcntl = smack_file_fcntl,
3438 .file_mmap = smack_file_mmap,
3439 .file_set_fowner = smack_file_set_fowner,
3440 .file_send_sigiotask = smack_file_send_sigiotask,
3441 .file_receive = smack_file_receive,
3442
3443 .cred_alloc_blank = smack_cred_alloc_blank,
3444 .cred_free = smack_cred_free,
3445 .cred_prepare = smack_cred_prepare,
3446 .cred_transfer = smack_cred_transfer,
3447 .kernel_act_as = smack_kernel_act_as,
3448 .kernel_create_files_as = smack_kernel_create_files_as,
3449 .task_setpgid = smack_task_setpgid,
3450 .task_getpgid = smack_task_getpgid,
3451 .task_getsid = smack_task_getsid,
3452 .task_getsecid = smack_task_getsecid,
3453 .task_setnice = smack_task_setnice,
3454 .task_setioprio = smack_task_setioprio,
3455 .task_getioprio = smack_task_getioprio,
3456 .task_setscheduler = smack_task_setscheduler,
3457 .task_getscheduler = smack_task_getscheduler,
3458 .task_movememory = smack_task_movememory,
3459 .task_kill = smack_task_kill,
3460 .task_wait = smack_task_wait,
3461 .task_to_inode = smack_task_to_inode,
3462
3463 .ipc_permission = smack_ipc_permission,
3464 .ipc_getsecid = smack_ipc_getsecid,
3465
3466 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
3467 .msg_msg_free_security = smack_msg_msg_free_security,
3468
3469 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
3470 .msg_queue_free_security = smack_msg_queue_free_security,
3471 .msg_queue_associate = smack_msg_queue_associate,
3472 .msg_queue_msgctl = smack_msg_queue_msgctl,
3473 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
3474 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
3475
3476 .shm_alloc_security = smack_shm_alloc_security,
3477 .shm_free_security = smack_shm_free_security,
3478 .shm_associate = smack_shm_associate,
3479 .shm_shmctl = smack_shm_shmctl,
3480 .shm_shmat = smack_shm_shmat,
3481
3482 .sem_alloc_security = smack_sem_alloc_security,
3483 .sem_free_security = smack_sem_free_security,
3484 .sem_associate = smack_sem_associate,
3485 .sem_semctl = smack_sem_semctl,
3486 .sem_semop = smack_sem_semop,
3487
3488 .d_instantiate = smack_d_instantiate,
3489
3490 .getprocattr = smack_getprocattr,
3491 .setprocattr = smack_setprocattr,
3492
3493 .unix_stream_connect = smack_unix_stream_connect,
3494 .unix_may_send = smack_unix_may_send,
3495
3496 .socket_post_create = smack_socket_post_create,
3497 .socket_connect = smack_socket_connect,
3498 .socket_sendmsg = smack_socket_sendmsg,
3499 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
3500 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
3501 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
3502 .sk_alloc_security = smack_sk_alloc_security,
3503 .sk_free_security = smack_sk_free_security,
3504 .sock_graft = smack_sock_graft,
3505 .inet_conn_request = smack_inet_conn_request,
3506 .inet_csk_clone = smack_inet_csk_clone,
3507
3508 /* key management security hooks */
3509#ifdef CONFIG_KEYS
3510 .key_alloc = smack_key_alloc,
3511 .key_free = smack_key_free,
3512 .key_permission = smack_key_permission,
3513#endif /* CONFIG_KEYS */
3514
3515 /* Audit hooks */
3516#ifdef CONFIG_AUDIT
3517 .audit_rule_init = smack_audit_rule_init,
3518 .audit_rule_known = smack_audit_rule_known,
3519 .audit_rule_match = smack_audit_rule_match,
3520 .audit_rule_free = smack_audit_rule_free,
3521#endif /* CONFIG_AUDIT */
3522
3523 .secid_to_secctx = smack_secid_to_secctx,
3524 .secctx_to_secid = smack_secctx_to_secid,
3525 .release_secctx = smack_release_secctx,
3526 .inode_notifysecctx = smack_inode_notifysecctx,
3527 .inode_setsecctx = smack_inode_setsecctx,
3528 .inode_getsecctx = smack_inode_getsecctx,
3529};
3530
3531
3532static __init void init_smack_know_list(void)
3533{
3534 list_add(&smack_known_huh.list, &smack_known_list);
3535 list_add(&smack_known_hat.list, &smack_known_list);
3536 list_add(&smack_known_star.list, &smack_known_list);
3537 list_add(&smack_known_floor.list, &smack_known_list);
3538 list_add(&smack_known_invalid.list, &smack_known_list);
3539 list_add(&smack_known_web.list, &smack_known_list);
3540}
3541
3542/**
3543 * smack_init - initialize the smack system
3544 *
3545 * Returns 0
3546 */
3547static __init int smack_init(void)
3548{
3549 struct cred *cred;
3550 struct task_smack *tsp;
3551
3552 if (!security_module_enable(&smack_ops))
3553 return 0;
3554
3555 tsp = new_task_smack(smack_known_floor.smk_known,
3556 smack_known_floor.smk_known, GFP_KERNEL);
3557 if (tsp == NULL)
3558 return -ENOMEM;
3559
3560 printk(KERN_INFO "Smack: Initializing.\n");
3561
3562 /*
3563 * Set the security state for the initial task.
3564 */
3565 cred = (struct cred *) current->cred;
3566 cred->security = tsp;
3567
3568 /* initialize the smack_know_list */
3569 init_smack_know_list();
3570 /*
3571 * Initialize locks
3572 */
3573 spin_lock_init(&smack_known_huh.smk_cipsolock);
3574 spin_lock_init(&smack_known_hat.smk_cipsolock);
3575 spin_lock_init(&smack_known_star.smk_cipsolock);
3576 spin_lock_init(&smack_known_floor.smk_cipsolock);
3577 spin_lock_init(&smack_known_invalid.smk_cipsolock);
3578
3579 /*
3580 * Register with LSM
3581 */
3582 if (register_security(&smack_ops))
3583 panic("smack: Unable to register with kernel.\n");
3584
3585 return 0;
3586}
3587
3588/*
3589 * Smack requires early initialization in order to label
3590 * all processes and objects when they are created.
3591 */
3592security_initcall(smack_init);
1/*
2 * Simplified MAC Kernel (smack) security module
3 *
4 * This file contains the smack hook function implementations.
5 *
6 * Authors:
7 * Casey Schaufler <casey@schaufler-ca.com>
8 * Jarkko Sakkinen <jarkko.sakkinen@intel.com>
9 *
10 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
11 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
12 * Paul Moore <paul@paul-moore.com>
13 * Copyright (C) 2010 Nokia Corporation
14 * Copyright (C) 2011 Intel Corporation.
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2,
18 * as published by the Free Software Foundation.
19 */
20
21#include <linux/xattr.h>
22#include <linux/pagemap.h>
23#include <linux/mount.h>
24#include <linux/stat.h>
25#include <linux/kd.h>
26#include <asm/ioctls.h>
27#include <linux/ip.h>
28#include <linux/tcp.h>
29#include <linux/udp.h>
30#include <linux/dccp.h>
31#include <linux/slab.h>
32#include <linux/mutex.h>
33#include <linux/pipe_fs_i.h>
34#include <net/cipso_ipv4.h>
35#include <net/ip.h>
36#include <net/ipv6.h>
37#include <linux/audit.h>
38#include <linux/magic.h>
39#include <linux/dcache.h>
40#include <linux/personality.h>
41#include <linux/msg.h>
42#include <linux/shm.h>
43#include <linux/binfmts.h>
44#include "smack.h"
45
46#define task_security(task) (task_cred_xxx((task), security))
47
48#define TRANS_TRUE "TRUE"
49#define TRANS_TRUE_SIZE 4
50
51#define SMK_CONNECTING 0
52#define SMK_RECEIVING 1
53#define SMK_SENDING 2
54
55LIST_HEAD(smk_ipv6_port_list);
56
57/**
58 * smk_fetch - Fetch the smack label from a file.
59 * @ip: a pointer to the inode
60 * @dp: a pointer to the dentry
61 *
62 * Returns a pointer to the master list entry for the Smack label
63 * or NULL if there was no label to fetch.
64 */
65static struct smack_known *smk_fetch(const char *name, struct inode *ip,
66 struct dentry *dp)
67{
68 int rc;
69 char *buffer;
70 struct smack_known *skp = NULL;
71
72 if (ip->i_op->getxattr == NULL)
73 return NULL;
74
75 buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
76 if (buffer == NULL)
77 return NULL;
78
79 rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
80 if (rc > 0)
81 skp = smk_import_entry(buffer, rc);
82
83 kfree(buffer);
84
85 return skp;
86}
87
88/**
89 * new_inode_smack - allocate an inode 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 */
94struct inode_smack *new_inode_smack(char *smack)
95{
96 struct inode_smack *isp;
97
98 isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS);
99 if (isp == NULL)
100 return NULL;
101
102 isp->smk_inode = smack;
103 isp->smk_flags = 0;
104 mutex_init(&isp->smk_lock);
105
106 return isp;
107}
108
109/**
110 * new_task_smack - allocate a task security blob
111 * @smack: a pointer to the Smack label to use in the blob
112 *
113 * Returns the new blob or NULL if there's no memory available
114 */
115static struct task_smack *new_task_smack(struct smack_known *task,
116 struct smack_known *forked, gfp_t gfp)
117{
118 struct task_smack *tsp;
119
120 tsp = kzalloc(sizeof(struct task_smack), gfp);
121 if (tsp == NULL)
122 return NULL;
123
124 tsp->smk_task = task;
125 tsp->smk_forked = forked;
126 INIT_LIST_HEAD(&tsp->smk_rules);
127 mutex_init(&tsp->smk_rules_lock);
128
129 return tsp;
130}
131
132/**
133 * smk_copy_rules - copy a rule set
134 * @nhead - new rules header pointer
135 * @ohead - old rules header pointer
136 *
137 * Returns 0 on success, -ENOMEM on error
138 */
139static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
140 gfp_t gfp)
141{
142 struct smack_rule *nrp;
143 struct smack_rule *orp;
144 int rc = 0;
145
146 INIT_LIST_HEAD(nhead);
147
148 list_for_each_entry_rcu(orp, ohead, list) {
149 nrp = kzalloc(sizeof(struct smack_rule), gfp);
150 if (nrp == NULL) {
151 rc = -ENOMEM;
152 break;
153 }
154 *nrp = *orp;
155 list_add_rcu(&nrp->list, nhead);
156 }
157 return rc;
158}
159
160/*
161 * LSM hooks.
162 * We he, that is fun!
163 */
164
165/**
166 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
167 * @ctp: child task pointer
168 * @mode: ptrace attachment mode
169 *
170 * Returns 0 if access is OK, an error code otherwise
171 *
172 * Do the capability checks, and require read and write.
173 */
174static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
175{
176 int rc;
177 struct smk_audit_info ad;
178 struct smack_known *skp;
179
180 rc = cap_ptrace_access_check(ctp, mode);
181 if (rc != 0)
182 return rc;
183
184 skp = smk_of_task(task_security(ctp));
185 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
186 smk_ad_setfield_u_tsk(&ad, ctp);
187
188 rc = smk_curacc(skp->smk_known, mode, &ad);
189 return rc;
190}
191
192/**
193 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
194 * @ptp: parent task pointer
195 *
196 * Returns 0 if access is OK, an error code otherwise
197 *
198 * Do the capability checks, and require read and write.
199 */
200static int smack_ptrace_traceme(struct task_struct *ptp)
201{
202 int rc;
203 struct smk_audit_info ad;
204 struct smack_known *skp;
205
206 rc = cap_ptrace_traceme(ptp);
207 if (rc != 0)
208 return rc;
209
210 skp = smk_of_task(task_security(ptp));
211 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
212 smk_ad_setfield_u_tsk(&ad, ptp);
213
214 rc = smk_curacc(skp->smk_known, MAY_READWRITE, &ad);
215 return rc;
216}
217
218/**
219 * smack_syslog - Smack approval on syslog
220 * @type: message type
221 *
222 * Returns 0 on success, error code otherwise.
223 */
224static int smack_syslog(int typefrom_file)
225{
226 int rc = 0;
227 struct smack_known *skp = smk_of_current();
228
229 if (smack_privileged(CAP_MAC_OVERRIDE))
230 return 0;
231
232 if (smack_syslog_label != NULL && smack_syslog_label != skp)
233 rc = -EACCES;
234
235 return rc;
236}
237
238
239/*
240 * Superblock Hooks.
241 */
242
243/**
244 * smack_sb_alloc_security - allocate a superblock blob
245 * @sb: the superblock getting the blob
246 *
247 * Returns 0 on success or -ENOMEM on error.
248 */
249static int smack_sb_alloc_security(struct super_block *sb)
250{
251 struct superblock_smack *sbsp;
252
253 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
254
255 if (sbsp == NULL)
256 return -ENOMEM;
257
258 sbsp->smk_root = smack_known_floor.smk_known;
259 sbsp->smk_default = smack_known_floor.smk_known;
260 sbsp->smk_floor = smack_known_floor.smk_known;
261 sbsp->smk_hat = smack_known_hat.smk_known;
262 /*
263 * smk_initialized will be zero from kzalloc.
264 */
265 sb->s_security = sbsp;
266
267 return 0;
268}
269
270/**
271 * smack_sb_free_security - free a superblock blob
272 * @sb: the superblock getting the blob
273 *
274 */
275static void smack_sb_free_security(struct super_block *sb)
276{
277 kfree(sb->s_security);
278 sb->s_security = NULL;
279}
280
281/**
282 * smack_sb_copy_data - copy mount options data for processing
283 * @orig: where to start
284 * @smackopts: mount options string
285 *
286 * Returns 0 on success or -ENOMEM on error.
287 *
288 * Copy the Smack specific mount options out of the mount
289 * options list.
290 */
291static int smack_sb_copy_data(char *orig, char *smackopts)
292{
293 char *cp, *commap, *otheropts, *dp;
294
295 otheropts = (char *)get_zeroed_page(GFP_KERNEL);
296 if (otheropts == NULL)
297 return -ENOMEM;
298
299 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
300 if (strstr(cp, SMK_FSDEFAULT) == cp)
301 dp = smackopts;
302 else if (strstr(cp, SMK_FSFLOOR) == cp)
303 dp = smackopts;
304 else if (strstr(cp, SMK_FSHAT) == cp)
305 dp = smackopts;
306 else if (strstr(cp, SMK_FSROOT) == cp)
307 dp = smackopts;
308 else if (strstr(cp, SMK_FSTRANS) == cp)
309 dp = smackopts;
310 else
311 dp = otheropts;
312
313 commap = strchr(cp, ',');
314 if (commap != NULL)
315 *commap = '\0';
316
317 if (*dp != '\0')
318 strcat(dp, ",");
319 strcat(dp, cp);
320 }
321
322 strcpy(orig, otheropts);
323 free_page((unsigned long)otheropts);
324
325 return 0;
326}
327
328/**
329 * smack_sb_kern_mount - Smack specific mount processing
330 * @sb: the file system superblock
331 * @flags: the mount flags
332 * @data: the smack mount options
333 *
334 * Returns 0 on success, an error code on failure
335 */
336static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
337{
338 struct dentry *root = sb->s_root;
339 struct inode *inode = root->d_inode;
340 struct superblock_smack *sp = sb->s_security;
341 struct inode_smack *isp;
342 struct smack_known *skp;
343 char *op;
344 char *commap;
345 char *nsp;
346 int transmute = 0;
347 int specified = 0;
348
349 if (sp->smk_initialized)
350 return 0;
351
352 sp->smk_initialized = 1;
353
354 for (op = data; op != NULL; op = commap) {
355 commap = strchr(op, ',');
356 if (commap != NULL)
357 *commap++ = '\0';
358
359 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
360 op += strlen(SMK_FSHAT);
361 nsp = smk_import(op, 0);
362 if (nsp != NULL) {
363 sp->smk_hat = nsp;
364 specified = 1;
365 }
366 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
367 op += strlen(SMK_FSFLOOR);
368 nsp = smk_import(op, 0);
369 if (nsp != NULL) {
370 sp->smk_floor = nsp;
371 specified = 1;
372 }
373 } else if (strncmp(op, SMK_FSDEFAULT,
374 strlen(SMK_FSDEFAULT)) == 0) {
375 op += strlen(SMK_FSDEFAULT);
376 nsp = smk_import(op, 0);
377 if (nsp != NULL) {
378 sp->smk_default = nsp;
379 specified = 1;
380 }
381 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
382 op += strlen(SMK_FSROOT);
383 nsp = smk_import(op, 0);
384 if (nsp != NULL) {
385 sp->smk_root = nsp;
386 specified = 1;
387 }
388 } else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
389 op += strlen(SMK_FSTRANS);
390 nsp = smk_import(op, 0);
391 if (nsp != NULL) {
392 sp->smk_root = nsp;
393 transmute = 1;
394 specified = 1;
395 }
396 }
397 }
398
399 if (!smack_privileged(CAP_MAC_ADMIN)) {
400 /*
401 * Unprivileged mounts don't get to specify Smack values.
402 */
403 if (specified)
404 return -EPERM;
405 /*
406 * Unprivileged mounts get root and default from the caller.
407 */
408 skp = smk_of_current();
409 sp->smk_root = skp->smk_known;
410 sp->smk_default = skp->smk_known;
411 }
412 /*
413 * Initialize the root inode.
414 */
415 isp = inode->i_security;
416 if (inode->i_security == NULL) {
417 inode->i_security = new_inode_smack(sp->smk_root);
418 isp = inode->i_security;
419 } else
420 isp->smk_inode = sp->smk_root;
421
422 if (transmute)
423 isp->smk_flags |= SMK_INODE_TRANSMUTE;
424
425 return 0;
426}
427
428/**
429 * smack_sb_statfs - Smack check on statfs
430 * @dentry: identifies the file system in question
431 *
432 * Returns 0 if current can read the floor of the filesystem,
433 * and error code otherwise
434 */
435static int smack_sb_statfs(struct dentry *dentry)
436{
437 struct superblock_smack *sbp = dentry->d_sb->s_security;
438 int rc;
439 struct smk_audit_info ad;
440
441 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
442 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
443
444 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
445 return rc;
446}
447
448/*
449 * BPRM hooks
450 */
451
452/**
453 * smack_bprm_set_creds - set creds for exec
454 * @bprm: the exec information
455 *
456 * Returns 0 if it gets a blob, -ENOMEM otherwise
457 */
458static int smack_bprm_set_creds(struct linux_binprm *bprm)
459{
460 struct inode *inode = file_inode(bprm->file);
461 struct task_smack *bsp = bprm->cred->security;
462 struct inode_smack *isp;
463 int rc;
464
465 rc = cap_bprm_set_creds(bprm);
466 if (rc != 0)
467 return rc;
468
469 if (bprm->cred_prepared)
470 return 0;
471
472 isp = inode->i_security;
473 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
474 return 0;
475
476 if (bprm->unsafe)
477 return -EPERM;
478
479 bsp->smk_task = isp->smk_task;
480 bprm->per_clear |= PER_CLEAR_ON_SETID;
481
482 return 0;
483}
484
485/**
486 * smack_bprm_committing_creds - Prepare to install the new credentials
487 * from bprm.
488 *
489 * @bprm: binprm for exec
490 */
491static void smack_bprm_committing_creds(struct linux_binprm *bprm)
492{
493 struct task_smack *bsp = bprm->cred->security;
494
495 if (bsp->smk_task != bsp->smk_forked)
496 current->pdeath_signal = 0;
497}
498
499/**
500 * smack_bprm_secureexec - Return the decision to use secureexec.
501 * @bprm: binprm for exec
502 *
503 * Returns 0 on success.
504 */
505static int smack_bprm_secureexec(struct linux_binprm *bprm)
506{
507 struct task_smack *tsp = current_security();
508 int ret = cap_bprm_secureexec(bprm);
509
510 if (!ret && (tsp->smk_task != tsp->smk_forked))
511 ret = 1;
512
513 return ret;
514}
515
516/*
517 * Inode hooks
518 */
519
520/**
521 * smack_inode_alloc_security - allocate an inode blob
522 * @inode: the inode in need of a blob
523 *
524 * Returns 0 if it gets a blob, -ENOMEM otherwise
525 */
526static int smack_inode_alloc_security(struct inode *inode)
527{
528 struct smack_known *skp = smk_of_current();
529
530 inode->i_security = new_inode_smack(skp->smk_known);
531 if (inode->i_security == NULL)
532 return -ENOMEM;
533 return 0;
534}
535
536/**
537 * smack_inode_free_security - free an inode blob
538 * @inode: the inode with a blob
539 *
540 * Clears the blob pointer in inode
541 */
542static void smack_inode_free_security(struct inode *inode)
543{
544 kfree(inode->i_security);
545 inode->i_security = NULL;
546}
547
548/**
549 * smack_inode_init_security - copy out the smack from an inode
550 * @inode: the inode
551 * @dir: unused
552 * @qstr: unused
553 * @name: where to put the attribute name
554 * @value: where to put the attribute value
555 * @len: where to put the length of the attribute
556 *
557 * Returns 0 if it all works out, -ENOMEM if there's no memory
558 */
559static int smack_inode_init_security(struct inode *inode, struct inode *dir,
560 const struct qstr *qstr, const char **name,
561 void **value, size_t *len)
562{
563 struct inode_smack *issp = inode->i_security;
564 struct smack_known *skp = smk_of_current();
565 char *isp = smk_of_inode(inode);
566 char *dsp = smk_of_inode(dir);
567 int may;
568
569 if (name)
570 *name = XATTR_SMACK_SUFFIX;
571
572 if (value) {
573 rcu_read_lock();
574 may = smk_access_entry(skp->smk_known, dsp, &skp->smk_rules);
575 rcu_read_unlock();
576
577 /*
578 * If the access rule allows transmutation and
579 * the directory requests transmutation then
580 * by all means transmute.
581 * Mark the inode as changed.
582 */
583 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
584 smk_inode_transmutable(dir)) {
585 isp = dsp;
586 issp->smk_flags |= SMK_INODE_CHANGED;
587 }
588
589 *value = kstrdup(isp, GFP_NOFS);
590 if (*value == NULL)
591 return -ENOMEM;
592 }
593
594 if (len)
595 *len = strlen(isp) + 1;
596
597 return 0;
598}
599
600/**
601 * smack_inode_link - Smack check on link
602 * @old_dentry: the existing object
603 * @dir: unused
604 * @new_dentry: the new object
605 *
606 * Returns 0 if access is permitted, an error code otherwise
607 */
608static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
609 struct dentry *new_dentry)
610{
611 char *isp;
612 struct smk_audit_info ad;
613 int rc;
614
615 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
616 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
617
618 isp = smk_of_inode(old_dentry->d_inode);
619 rc = smk_curacc(isp, MAY_WRITE, &ad);
620
621 if (rc == 0 && new_dentry->d_inode != NULL) {
622 isp = smk_of_inode(new_dentry->d_inode);
623 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
624 rc = smk_curacc(isp, MAY_WRITE, &ad);
625 }
626
627 return rc;
628}
629
630/**
631 * smack_inode_unlink - Smack check on inode deletion
632 * @dir: containing directory object
633 * @dentry: file to unlink
634 *
635 * Returns 0 if current can write the containing directory
636 * and the object, error code otherwise
637 */
638static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
639{
640 struct inode *ip = dentry->d_inode;
641 struct smk_audit_info ad;
642 int rc;
643
644 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
645 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
646
647 /*
648 * You need write access to the thing you're unlinking
649 */
650 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
651 if (rc == 0) {
652 /*
653 * You also need write access to the containing directory
654 */
655 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
656 smk_ad_setfield_u_fs_inode(&ad, dir);
657 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
658 }
659 return rc;
660}
661
662/**
663 * smack_inode_rmdir - Smack check on directory deletion
664 * @dir: containing directory object
665 * @dentry: directory to unlink
666 *
667 * Returns 0 if current can write the containing directory
668 * and the directory, error code otherwise
669 */
670static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
671{
672 struct smk_audit_info ad;
673 int rc;
674
675 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
676 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
677
678 /*
679 * You need write access to the thing you're removing
680 */
681 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
682 if (rc == 0) {
683 /*
684 * You also need write access to the containing directory
685 */
686 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
687 smk_ad_setfield_u_fs_inode(&ad, dir);
688 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
689 }
690
691 return rc;
692}
693
694/**
695 * smack_inode_rename - Smack check on rename
696 * @old_inode: the old directory
697 * @old_dentry: unused
698 * @new_inode: the new directory
699 * @new_dentry: unused
700 *
701 * Read and write access is required on both the old and
702 * new directories.
703 *
704 * Returns 0 if access is permitted, an error code otherwise
705 */
706static int smack_inode_rename(struct inode *old_inode,
707 struct dentry *old_dentry,
708 struct inode *new_inode,
709 struct dentry *new_dentry)
710{
711 int rc;
712 char *isp;
713 struct smk_audit_info ad;
714
715 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
716 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
717
718 isp = smk_of_inode(old_dentry->d_inode);
719 rc = smk_curacc(isp, MAY_READWRITE, &ad);
720
721 if (rc == 0 && new_dentry->d_inode != NULL) {
722 isp = smk_of_inode(new_dentry->d_inode);
723 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
724 rc = smk_curacc(isp, MAY_READWRITE, &ad);
725 }
726 return rc;
727}
728
729/**
730 * smack_inode_permission - Smack version of permission()
731 * @inode: the inode in question
732 * @mask: the access requested
733 *
734 * This is the important Smack hook.
735 *
736 * Returns 0 if access is permitted, -EACCES otherwise
737 */
738static int smack_inode_permission(struct inode *inode, int mask)
739{
740 struct smk_audit_info ad;
741 int no_block = mask & MAY_NOT_BLOCK;
742
743 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
744 /*
745 * No permission to check. Existence test. Yup, it's there.
746 */
747 if (mask == 0)
748 return 0;
749
750 /* May be droppable after audit */
751 if (no_block)
752 return -ECHILD;
753 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
754 smk_ad_setfield_u_fs_inode(&ad, inode);
755 return smk_curacc(smk_of_inode(inode), mask, &ad);
756}
757
758/**
759 * smack_inode_setattr - Smack check for setting attributes
760 * @dentry: the object
761 * @iattr: for the force flag
762 *
763 * Returns 0 if access is permitted, an error code otherwise
764 */
765static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
766{
767 struct smk_audit_info ad;
768 /*
769 * Need to allow for clearing the setuid bit.
770 */
771 if (iattr->ia_valid & ATTR_FORCE)
772 return 0;
773 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
774 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
775
776 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
777}
778
779/**
780 * smack_inode_getattr - Smack check for getting attributes
781 * @mnt: unused
782 * @dentry: the object
783 *
784 * Returns 0 if access is permitted, an error code otherwise
785 */
786static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
787{
788 struct smk_audit_info ad;
789 struct path path;
790
791 path.dentry = dentry;
792 path.mnt = mnt;
793
794 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
795 smk_ad_setfield_u_fs_path(&ad, path);
796 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
797}
798
799/**
800 * smack_inode_setxattr - Smack check for setting xattrs
801 * @dentry: the object
802 * @name: name of the attribute
803 * @value: unused
804 * @size: unused
805 * @flags: unused
806 *
807 * This protects the Smack attribute explicitly.
808 *
809 * Returns 0 if access is permitted, an error code otherwise
810 */
811static int smack_inode_setxattr(struct dentry *dentry, const char *name,
812 const void *value, size_t size, int flags)
813{
814 struct smk_audit_info ad;
815 struct smack_known *skp;
816 int check_priv = 0;
817 int check_import = 0;
818 int check_star = 0;
819 int rc = 0;
820
821 /*
822 * Check label validity here so import won't fail in post_setxattr
823 */
824 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
825 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
826 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
827 check_priv = 1;
828 check_import = 1;
829 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
830 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
831 check_priv = 1;
832 check_import = 1;
833 check_star = 1;
834 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
835 check_priv = 1;
836 if (size != TRANS_TRUE_SIZE ||
837 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
838 rc = -EINVAL;
839 } else
840 rc = cap_inode_setxattr(dentry, name, value, size, flags);
841
842 if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
843 rc = -EPERM;
844
845 if (rc == 0 && check_import) {
846 skp = smk_import_entry(value, size);
847 if (skp == NULL || (check_star &&
848 (skp == &smack_known_star || skp == &smack_known_web)))
849 rc = -EINVAL;
850 }
851
852 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
853 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
854
855 if (rc == 0)
856 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
857
858 return rc;
859}
860
861/**
862 * smack_inode_post_setxattr - Apply the Smack update approved above
863 * @dentry: object
864 * @name: attribute name
865 * @value: attribute value
866 * @size: attribute size
867 * @flags: unused
868 *
869 * Set the pointer in the inode blob to the entry found
870 * in the master label list.
871 */
872static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
873 const void *value, size_t size, int flags)
874{
875 struct smack_known *skp;
876 struct inode_smack *isp = dentry->d_inode->i_security;
877
878 if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
879 isp->smk_flags |= SMK_INODE_TRANSMUTE;
880 return;
881 }
882
883 skp = smk_import_entry(value, size);
884 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
885 if (skp != NULL)
886 isp->smk_inode = skp->smk_known;
887 else
888 isp->smk_inode = smack_known_invalid.smk_known;
889 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
890 if (skp != NULL)
891 isp->smk_task = skp;
892 else
893 isp->smk_task = &smack_known_invalid;
894 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
895 if (skp != NULL)
896 isp->smk_mmap = skp;
897 else
898 isp->smk_mmap = &smack_known_invalid;
899 }
900
901 return;
902}
903
904/**
905 * smack_inode_getxattr - Smack check on getxattr
906 * @dentry: the object
907 * @name: unused
908 *
909 * Returns 0 if access is permitted, an error code otherwise
910 */
911static int smack_inode_getxattr(struct dentry *dentry, const char *name)
912{
913 struct smk_audit_info ad;
914
915 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
916 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
917
918 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
919}
920
921/**
922 * smack_inode_removexattr - Smack check on removexattr
923 * @dentry: the object
924 * @name: name of the attribute
925 *
926 * Removing the Smack attribute requires CAP_MAC_ADMIN
927 *
928 * Returns 0 if access is permitted, an error code otherwise
929 */
930static int smack_inode_removexattr(struct dentry *dentry, const char *name)
931{
932 struct inode_smack *isp;
933 struct smk_audit_info ad;
934 int rc = 0;
935
936 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
937 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
938 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
939 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
940 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
941 strcmp(name, XATTR_NAME_SMACKMMAP)) {
942 if (!smack_privileged(CAP_MAC_ADMIN))
943 rc = -EPERM;
944 } else
945 rc = cap_inode_removexattr(dentry, name);
946
947 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
948 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
949 if (rc == 0)
950 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
951
952 if (rc == 0) {
953 isp = dentry->d_inode->i_security;
954 isp->smk_task = NULL;
955 isp->smk_mmap = NULL;
956 }
957
958 return rc;
959}
960
961/**
962 * smack_inode_getsecurity - get smack xattrs
963 * @inode: the object
964 * @name: attribute name
965 * @buffer: where to put the result
966 * @alloc: unused
967 *
968 * Returns the size of the attribute or an error code
969 */
970static int smack_inode_getsecurity(const struct inode *inode,
971 const char *name, void **buffer,
972 bool alloc)
973{
974 struct socket_smack *ssp;
975 struct socket *sock;
976 struct super_block *sbp;
977 struct inode *ip = (struct inode *)inode;
978 char *isp;
979 int ilen;
980 int rc = 0;
981
982 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
983 isp = smk_of_inode(inode);
984 ilen = strlen(isp) + 1;
985 *buffer = isp;
986 return ilen;
987 }
988
989 /*
990 * The rest of the Smack xattrs are only on sockets.
991 */
992 sbp = ip->i_sb;
993 if (sbp->s_magic != SOCKFS_MAGIC)
994 return -EOPNOTSUPP;
995
996 sock = SOCKET_I(ip);
997 if (sock == NULL || sock->sk == NULL)
998 return -EOPNOTSUPP;
999
1000 ssp = sock->sk->sk_security;
1001
1002 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1003 isp = ssp->smk_in;
1004 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1005 isp = ssp->smk_out->smk_known;
1006 else
1007 return -EOPNOTSUPP;
1008
1009 ilen = strlen(isp) + 1;
1010 if (rc == 0) {
1011 *buffer = isp;
1012 rc = ilen;
1013 }
1014
1015 return rc;
1016}
1017
1018
1019/**
1020 * smack_inode_listsecurity - list the Smack attributes
1021 * @inode: the object
1022 * @buffer: where they go
1023 * @buffer_size: size of buffer
1024 *
1025 * Returns 0 on success, -EINVAL otherwise
1026 */
1027static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1028 size_t buffer_size)
1029{
1030 int len = strlen(XATTR_NAME_SMACK);
1031
1032 if (buffer != NULL && len <= buffer_size) {
1033 memcpy(buffer, XATTR_NAME_SMACK, len);
1034 return len;
1035 }
1036 return -EINVAL;
1037}
1038
1039/**
1040 * smack_inode_getsecid - Extract inode's security id
1041 * @inode: inode to extract the info from
1042 * @secid: where result will be saved
1043 */
1044static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
1045{
1046 struct inode_smack *isp = inode->i_security;
1047
1048 *secid = smack_to_secid(isp->smk_inode);
1049}
1050
1051/*
1052 * File Hooks
1053 */
1054
1055/**
1056 * smack_file_permission - Smack check on file operations
1057 * @file: unused
1058 * @mask: unused
1059 *
1060 * Returns 0
1061 *
1062 * Should access checks be done on each read or write?
1063 * UNICOS and SELinux say yes.
1064 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1065 *
1066 * I'll say no for now. Smack does not do the frequent
1067 * label changing that SELinux does.
1068 */
1069static int smack_file_permission(struct file *file, int mask)
1070{
1071 return 0;
1072}
1073
1074/**
1075 * smack_file_alloc_security - assign a file security blob
1076 * @file: the object
1077 *
1078 * The security blob for a file is a pointer to the master
1079 * label list, so no allocation is done.
1080 *
1081 * Returns 0
1082 */
1083static int smack_file_alloc_security(struct file *file)
1084{
1085 struct smack_known *skp = smk_of_current();
1086
1087 file->f_security = skp->smk_known;
1088 return 0;
1089}
1090
1091/**
1092 * smack_file_free_security - clear a file security blob
1093 * @file: the object
1094 *
1095 * The security blob for a file is a pointer to the master
1096 * label list, so no memory is freed.
1097 */
1098static void smack_file_free_security(struct file *file)
1099{
1100 file->f_security = NULL;
1101}
1102
1103/**
1104 * smack_file_ioctl - Smack check on ioctls
1105 * @file: the object
1106 * @cmd: what to do
1107 * @arg: unused
1108 *
1109 * Relies heavily on the correct use of the ioctl command conventions.
1110 *
1111 * Returns 0 if allowed, error code otherwise
1112 */
1113static int smack_file_ioctl(struct file *file, unsigned int cmd,
1114 unsigned long arg)
1115{
1116 int rc = 0;
1117 struct smk_audit_info ad;
1118
1119 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1120 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1121
1122 if (_IOC_DIR(cmd) & _IOC_WRITE)
1123 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1124
1125 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1126 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1127
1128 return rc;
1129}
1130
1131/**
1132 * smack_file_lock - Smack check on file locking
1133 * @file: the object
1134 * @cmd: unused
1135 *
1136 * Returns 0 if current has lock access, error code otherwise
1137 */
1138static int smack_file_lock(struct file *file, unsigned int cmd)
1139{
1140 struct smk_audit_info ad;
1141
1142 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1143 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1144 return smk_curacc(file->f_security, MAY_LOCK, &ad);
1145}
1146
1147/**
1148 * smack_file_fcntl - Smack check on fcntl
1149 * @file: the object
1150 * @cmd: what action to check
1151 * @arg: unused
1152 *
1153 * Generally these operations are harmless.
1154 * File locking operations present an obvious mechanism
1155 * for passing information, so they require write access.
1156 *
1157 * Returns 0 if current has access, error code otherwise
1158 */
1159static int smack_file_fcntl(struct file *file, unsigned int cmd,
1160 unsigned long arg)
1161{
1162 struct smk_audit_info ad;
1163 int rc = 0;
1164
1165
1166 switch (cmd) {
1167 case F_GETLK:
1168 break;
1169 case F_SETLK:
1170 case F_SETLKW:
1171 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1172 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1173 rc = smk_curacc(file->f_security, MAY_LOCK, &ad);
1174 break;
1175 case F_SETOWN:
1176 case F_SETSIG:
1177 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1178 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1179 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1180 break;
1181 default:
1182 break;
1183 }
1184
1185 return rc;
1186}
1187
1188/**
1189 * smack_mmap_file :
1190 * Check permissions for a mmap operation. The @file may be NULL, e.g.
1191 * if mapping anonymous memory.
1192 * @file contains the file structure for file to map (may be NULL).
1193 * @reqprot contains the protection requested by the application.
1194 * @prot contains the protection that will be applied by the kernel.
1195 * @flags contains the operational flags.
1196 * Return 0 if permission is granted.
1197 */
1198static int smack_mmap_file(struct file *file,
1199 unsigned long reqprot, unsigned long prot,
1200 unsigned long flags)
1201{
1202 struct smack_known *skp;
1203 struct smack_known *mkp;
1204 struct smack_rule *srp;
1205 struct task_smack *tsp;
1206 char *osmack;
1207 struct inode_smack *isp;
1208 int may;
1209 int mmay;
1210 int tmay;
1211 int rc;
1212
1213 if (file == NULL)
1214 return 0;
1215
1216 isp = file_inode(file)->i_security;
1217 if (isp->smk_mmap == NULL)
1218 return 0;
1219 mkp = isp->smk_mmap;
1220
1221 tsp = current_security();
1222 skp = smk_of_current();
1223 rc = 0;
1224
1225 rcu_read_lock();
1226 /*
1227 * For each Smack rule associated with the subject
1228 * label verify that the SMACK64MMAP also has access
1229 * to that rule's object label.
1230 */
1231 list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1232 osmack = srp->smk_object;
1233 /*
1234 * Matching labels always allows access.
1235 */
1236 if (mkp->smk_known == osmack)
1237 continue;
1238 /*
1239 * If there is a matching local rule take
1240 * that into account as well.
1241 */
1242 may = smk_access_entry(srp->smk_subject->smk_known, osmack,
1243 &tsp->smk_rules);
1244 if (may == -ENOENT)
1245 may = srp->smk_access;
1246 else
1247 may &= srp->smk_access;
1248 /*
1249 * If may is zero the SMACK64MMAP subject can't
1250 * possibly have less access.
1251 */
1252 if (may == 0)
1253 continue;
1254
1255 /*
1256 * Fetch the global list entry.
1257 * If there isn't one a SMACK64MMAP subject
1258 * can't have as much access as current.
1259 */
1260 mmay = smk_access_entry(mkp->smk_known, osmack,
1261 &mkp->smk_rules);
1262 if (mmay == -ENOENT) {
1263 rc = -EACCES;
1264 break;
1265 }
1266 /*
1267 * If there is a local entry it modifies the
1268 * potential access, too.
1269 */
1270 tmay = smk_access_entry(mkp->smk_known, osmack,
1271 &tsp->smk_rules);
1272 if (tmay != -ENOENT)
1273 mmay &= tmay;
1274
1275 /*
1276 * If there is any access available to current that is
1277 * not available to a SMACK64MMAP subject
1278 * deny access.
1279 */
1280 if ((may | mmay) != mmay) {
1281 rc = -EACCES;
1282 break;
1283 }
1284 }
1285
1286 rcu_read_unlock();
1287
1288 return rc;
1289}
1290
1291/**
1292 * smack_file_set_fowner - set the file security blob value
1293 * @file: object in question
1294 *
1295 * Returns 0
1296 * Further research may be required on this one.
1297 */
1298static int smack_file_set_fowner(struct file *file)
1299{
1300 struct smack_known *skp = smk_of_current();
1301
1302 file->f_security = skp->smk_known;
1303 return 0;
1304}
1305
1306/**
1307 * smack_file_send_sigiotask - Smack on sigio
1308 * @tsk: The target task
1309 * @fown: the object the signal come from
1310 * @signum: unused
1311 *
1312 * Allow a privileged task to get signals even if it shouldn't
1313 *
1314 * Returns 0 if a subject with the object's smack could
1315 * write to the task, an error code otherwise.
1316 */
1317static int smack_file_send_sigiotask(struct task_struct *tsk,
1318 struct fown_struct *fown, int signum)
1319{
1320 struct smack_known *skp;
1321 struct smack_known *tkp = smk_of_task(tsk->cred->security);
1322 struct file *file;
1323 int rc;
1324 struct smk_audit_info ad;
1325
1326 /*
1327 * struct fown_struct is never outside the context of a struct file
1328 */
1329 file = container_of(fown, struct file, f_owner);
1330
1331 /* we don't log here as rc can be overriden */
1332 skp = smk_find_entry(file->f_security);
1333 rc = smk_access(skp, tkp->smk_known, MAY_WRITE, NULL);
1334 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1335 rc = 0;
1336
1337 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1338 smk_ad_setfield_u_tsk(&ad, tsk);
1339 smack_log(file->f_security, tkp->smk_known, MAY_WRITE, rc, &ad);
1340 return rc;
1341}
1342
1343/**
1344 * smack_file_receive - Smack file receive check
1345 * @file: the object
1346 *
1347 * Returns 0 if current has access, error code otherwise
1348 */
1349static int smack_file_receive(struct file *file)
1350{
1351 int may = 0;
1352 struct smk_audit_info ad;
1353
1354 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1355 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1356 /*
1357 * This code relies on bitmasks.
1358 */
1359 if (file->f_mode & FMODE_READ)
1360 may = MAY_READ;
1361 if (file->f_mode & FMODE_WRITE)
1362 may |= MAY_WRITE;
1363
1364 return smk_curacc(file->f_security, may, &ad);
1365}
1366
1367/**
1368 * smack_file_open - Smack dentry open processing
1369 * @file: the object
1370 * @cred: unused
1371 *
1372 * Set the security blob in the file structure.
1373 *
1374 * Returns 0
1375 */
1376static int smack_file_open(struct file *file, const struct cred *cred)
1377{
1378 struct inode_smack *isp = file_inode(file)->i_security;
1379
1380 file->f_security = isp->smk_inode;
1381
1382 return 0;
1383}
1384
1385/*
1386 * Task hooks
1387 */
1388
1389/**
1390 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1391 * @new: the new credentials
1392 * @gfp: the atomicity of any memory allocations
1393 *
1394 * Prepare a blank set of credentials for modification. This must allocate all
1395 * the memory the LSM module might require such that cred_transfer() can
1396 * complete without error.
1397 */
1398static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1399{
1400 struct task_smack *tsp;
1401
1402 tsp = new_task_smack(NULL, NULL, gfp);
1403 if (tsp == NULL)
1404 return -ENOMEM;
1405
1406 cred->security = tsp;
1407
1408 return 0;
1409}
1410
1411
1412/**
1413 * smack_cred_free - "free" task-level security credentials
1414 * @cred: the credentials in question
1415 *
1416 */
1417static void smack_cred_free(struct cred *cred)
1418{
1419 struct task_smack *tsp = cred->security;
1420 struct smack_rule *rp;
1421 struct list_head *l;
1422 struct list_head *n;
1423
1424 if (tsp == NULL)
1425 return;
1426 cred->security = NULL;
1427
1428 list_for_each_safe(l, n, &tsp->smk_rules) {
1429 rp = list_entry(l, struct smack_rule, list);
1430 list_del(&rp->list);
1431 kfree(rp);
1432 }
1433 kfree(tsp);
1434}
1435
1436/**
1437 * smack_cred_prepare - prepare new set of credentials for modification
1438 * @new: the new credentials
1439 * @old: the original credentials
1440 * @gfp: the atomicity of any memory allocations
1441 *
1442 * Prepare a new set of credentials for modification.
1443 */
1444static int smack_cred_prepare(struct cred *new, const struct cred *old,
1445 gfp_t gfp)
1446{
1447 struct task_smack *old_tsp = old->security;
1448 struct task_smack *new_tsp;
1449 int rc;
1450
1451 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1452 if (new_tsp == NULL)
1453 return -ENOMEM;
1454
1455 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1456 if (rc != 0)
1457 return rc;
1458
1459 new->security = new_tsp;
1460 return 0;
1461}
1462
1463/**
1464 * smack_cred_transfer - Transfer the old credentials to the new credentials
1465 * @new: the new credentials
1466 * @old: the original credentials
1467 *
1468 * Fill in a set of blank credentials from another set of credentials.
1469 */
1470static void smack_cred_transfer(struct cred *new, const struct cred *old)
1471{
1472 struct task_smack *old_tsp = old->security;
1473 struct task_smack *new_tsp = new->security;
1474
1475 new_tsp->smk_task = old_tsp->smk_task;
1476 new_tsp->smk_forked = old_tsp->smk_task;
1477 mutex_init(&new_tsp->smk_rules_lock);
1478 INIT_LIST_HEAD(&new_tsp->smk_rules);
1479
1480
1481 /* cbs copy rule list */
1482}
1483
1484/**
1485 * smack_kernel_act_as - Set the subjective context in a set of credentials
1486 * @new: points to the set of credentials to be modified.
1487 * @secid: specifies the security ID to be set
1488 *
1489 * Set the security data for a kernel service.
1490 */
1491static int smack_kernel_act_as(struct cred *new, u32 secid)
1492{
1493 struct task_smack *new_tsp = new->security;
1494 struct smack_known *skp = smack_from_secid(secid);
1495
1496 if (skp == NULL)
1497 return -EINVAL;
1498
1499 new_tsp->smk_task = skp;
1500 return 0;
1501}
1502
1503/**
1504 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1505 * @new: points to the set of credentials to be modified
1506 * @inode: points to the inode to use as a reference
1507 *
1508 * Set the file creation context in a set of credentials to the same
1509 * as the objective context of the specified inode
1510 */
1511static int smack_kernel_create_files_as(struct cred *new,
1512 struct inode *inode)
1513{
1514 struct inode_smack *isp = inode->i_security;
1515 struct task_smack *tsp = new->security;
1516
1517 tsp->smk_forked = smk_find_entry(isp->smk_inode);
1518 tsp->smk_task = tsp->smk_forked;
1519 return 0;
1520}
1521
1522/**
1523 * smk_curacc_on_task - helper to log task related access
1524 * @p: the task object
1525 * @access: the access requested
1526 * @caller: name of the calling function for audit
1527 *
1528 * Return 0 if access is permitted
1529 */
1530static int smk_curacc_on_task(struct task_struct *p, int access,
1531 const char *caller)
1532{
1533 struct smk_audit_info ad;
1534 struct smack_known *skp = smk_of_task(task_security(p));
1535
1536 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
1537 smk_ad_setfield_u_tsk(&ad, p);
1538 return smk_curacc(skp->smk_known, access, &ad);
1539}
1540
1541/**
1542 * smack_task_setpgid - Smack check on setting pgid
1543 * @p: the task object
1544 * @pgid: unused
1545 *
1546 * Return 0 if write access is permitted
1547 */
1548static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1549{
1550 return smk_curacc_on_task(p, MAY_WRITE, __func__);
1551}
1552
1553/**
1554 * smack_task_getpgid - Smack access check for getpgid
1555 * @p: the object task
1556 *
1557 * Returns 0 if current can read the object task, error code otherwise
1558 */
1559static int smack_task_getpgid(struct task_struct *p)
1560{
1561 return smk_curacc_on_task(p, MAY_READ, __func__);
1562}
1563
1564/**
1565 * smack_task_getsid - Smack access check for getsid
1566 * @p: the object task
1567 *
1568 * Returns 0 if current can read the object task, error code otherwise
1569 */
1570static int smack_task_getsid(struct task_struct *p)
1571{
1572 return smk_curacc_on_task(p, MAY_READ, __func__);
1573}
1574
1575/**
1576 * smack_task_getsecid - get the secid of the task
1577 * @p: the object task
1578 * @secid: where to put the result
1579 *
1580 * Sets the secid to contain a u32 version of the smack label.
1581 */
1582static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1583{
1584 struct smack_known *skp = smk_of_task(task_security(p));
1585
1586 *secid = skp->smk_secid;
1587}
1588
1589/**
1590 * smack_task_setnice - Smack check on setting nice
1591 * @p: the task object
1592 * @nice: unused
1593 *
1594 * Return 0 if write access is permitted
1595 */
1596static int smack_task_setnice(struct task_struct *p, int nice)
1597{
1598 int rc;
1599
1600 rc = cap_task_setnice(p, nice);
1601 if (rc == 0)
1602 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1603 return rc;
1604}
1605
1606/**
1607 * smack_task_setioprio - Smack check on setting ioprio
1608 * @p: the task object
1609 * @ioprio: unused
1610 *
1611 * Return 0 if write access is permitted
1612 */
1613static int smack_task_setioprio(struct task_struct *p, int ioprio)
1614{
1615 int rc;
1616
1617 rc = cap_task_setioprio(p, ioprio);
1618 if (rc == 0)
1619 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1620 return rc;
1621}
1622
1623/**
1624 * smack_task_getioprio - Smack check on reading ioprio
1625 * @p: the task object
1626 *
1627 * Return 0 if read access is permitted
1628 */
1629static int smack_task_getioprio(struct task_struct *p)
1630{
1631 return smk_curacc_on_task(p, MAY_READ, __func__);
1632}
1633
1634/**
1635 * smack_task_setscheduler - Smack check on setting scheduler
1636 * @p: the task object
1637 * @policy: unused
1638 * @lp: unused
1639 *
1640 * Return 0 if read access is permitted
1641 */
1642static int smack_task_setscheduler(struct task_struct *p)
1643{
1644 int rc;
1645
1646 rc = cap_task_setscheduler(p);
1647 if (rc == 0)
1648 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1649 return rc;
1650}
1651
1652/**
1653 * smack_task_getscheduler - Smack check on reading scheduler
1654 * @p: the task object
1655 *
1656 * Return 0 if read access is permitted
1657 */
1658static int smack_task_getscheduler(struct task_struct *p)
1659{
1660 return smk_curacc_on_task(p, MAY_READ, __func__);
1661}
1662
1663/**
1664 * smack_task_movememory - Smack check on moving memory
1665 * @p: the task object
1666 *
1667 * Return 0 if write access is permitted
1668 */
1669static int smack_task_movememory(struct task_struct *p)
1670{
1671 return smk_curacc_on_task(p, MAY_WRITE, __func__);
1672}
1673
1674/**
1675 * smack_task_kill - Smack check on signal delivery
1676 * @p: the task object
1677 * @info: unused
1678 * @sig: unused
1679 * @secid: identifies the smack to use in lieu of current's
1680 *
1681 * Return 0 if write access is permitted
1682 *
1683 * The secid behavior is an artifact of an SELinux hack
1684 * in the USB code. Someday it may go away.
1685 */
1686static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1687 int sig, u32 secid)
1688{
1689 struct smk_audit_info ad;
1690 struct smack_known *skp;
1691 struct smack_known *tkp = smk_of_task(task_security(p));
1692
1693 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1694 smk_ad_setfield_u_tsk(&ad, p);
1695 /*
1696 * Sending a signal requires that the sender
1697 * can write the receiver.
1698 */
1699 if (secid == 0)
1700 return smk_curacc(tkp->smk_known, MAY_WRITE, &ad);
1701 /*
1702 * If the secid isn't 0 we're dealing with some USB IO
1703 * specific behavior. This is not clean. For one thing
1704 * we can't take privilege into account.
1705 */
1706 skp = smack_from_secid(secid);
1707 return smk_access(skp, tkp->smk_known, MAY_WRITE, &ad);
1708}
1709
1710/**
1711 * smack_task_wait - Smack access check for waiting
1712 * @p: task to wait for
1713 *
1714 * Returns 0
1715 */
1716static int smack_task_wait(struct task_struct *p)
1717{
1718 /*
1719 * Allow the operation to succeed.
1720 * Zombies are bad.
1721 * In userless environments (e.g. phones) programs
1722 * get marked with SMACK64EXEC and even if the parent
1723 * and child shouldn't be talking the parent still
1724 * may expect to know when the child exits.
1725 */
1726 return 0;
1727}
1728
1729/**
1730 * smack_task_to_inode - copy task smack into the inode blob
1731 * @p: task to copy from
1732 * @inode: inode to copy to
1733 *
1734 * Sets the smack pointer in the inode security blob
1735 */
1736static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1737{
1738 struct inode_smack *isp = inode->i_security;
1739 struct smack_known *skp = smk_of_task(task_security(p));
1740
1741 isp->smk_inode = skp->smk_known;
1742}
1743
1744/*
1745 * Socket hooks.
1746 */
1747
1748/**
1749 * smack_sk_alloc_security - Allocate a socket blob
1750 * @sk: the socket
1751 * @family: unused
1752 * @gfp_flags: memory allocation flags
1753 *
1754 * Assign Smack pointers to current
1755 *
1756 * Returns 0 on success, -ENOMEM is there's no memory
1757 */
1758static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1759{
1760 struct smack_known *skp = smk_of_current();
1761 struct socket_smack *ssp;
1762
1763 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1764 if (ssp == NULL)
1765 return -ENOMEM;
1766
1767 ssp->smk_in = skp->smk_known;
1768 ssp->smk_out = skp;
1769 ssp->smk_packet = NULL;
1770
1771 sk->sk_security = ssp;
1772
1773 return 0;
1774}
1775
1776/**
1777 * smack_sk_free_security - Free a socket blob
1778 * @sk: the socket
1779 *
1780 * Clears the blob pointer
1781 */
1782static void smack_sk_free_security(struct sock *sk)
1783{
1784 kfree(sk->sk_security);
1785}
1786
1787/**
1788* smack_host_label - check host based restrictions
1789* @sip: the object end
1790*
1791* looks for host based access restrictions
1792*
1793* This version will only be appropriate for really small sets of single label
1794* hosts. The caller is responsible for ensuring that the RCU read lock is
1795* taken before calling this function.
1796*
1797* Returns the label of the far end or NULL if it's not special.
1798*/
1799static char *smack_host_label(struct sockaddr_in *sip)
1800{
1801 struct smk_netlbladdr *snp;
1802 struct in_addr *siap = &sip->sin_addr;
1803
1804 if (siap->s_addr == 0)
1805 return NULL;
1806
1807 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1808 /*
1809 * we break after finding the first match because
1810 * the list is sorted from longest to shortest mask
1811 * so we have found the most specific match
1812 */
1813 if ((&snp->smk_host.sin_addr)->s_addr ==
1814 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1815 /* we have found the special CIPSO option */
1816 if (snp->smk_label == smack_cipso_option)
1817 return NULL;
1818 return snp->smk_label;
1819 }
1820
1821 return NULL;
1822}
1823
1824/**
1825 * smack_netlabel - Set the secattr on a socket
1826 * @sk: the socket
1827 * @labeled: socket label scheme
1828 *
1829 * Convert the outbound smack value (smk_out) to a
1830 * secattr and attach it to the socket.
1831 *
1832 * Returns 0 on success or an error code
1833 */
1834static int smack_netlabel(struct sock *sk, int labeled)
1835{
1836 struct smack_known *skp;
1837 struct socket_smack *ssp = sk->sk_security;
1838 int rc = 0;
1839
1840 /*
1841 * Usually the netlabel code will handle changing the
1842 * packet labeling based on the label.
1843 * The case of a single label host is different, because
1844 * a single label host should never get a labeled packet
1845 * even though the label is usually associated with a packet
1846 * label.
1847 */
1848 local_bh_disable();
1849 bh_lock_sock_nested(sk);
1850
1851 if (ssp->smk_out == smack_net_ambient ||
1852 labeled == SMACK_UNLABELED_SOCKET)
1853 netlbl_sock_delattr(sk);
1854 else {
1855 skp = ssp->smk_out;
1856 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
1857 }
1858
1859 bh_unlock_sock(sk);
1860 local_bh_enable();
1861
1862 return rc;
1863}
1864
1865/**
1866 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1867 * @sk: the socket
1868 * @sap: the destination address
1869 *
1870 * Set the correct secattr for the given socket based on the destination
1871 * address and perform any outbound access checks needed.
1872 *
1873 * Returns 0 on success or an error code.
1874 *
1875 */
1876static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1877{
1878 struct smack_known *skp;
1879 int rc;
1880 int sk_lbl;
1881 char *hostsp;
1882 struct socket_smack *ssp = sk->sk_security;
1883 struct smk_audit_info ad;
1884
1885 rcu_read_lock();
1886 hostsp = smack_host_label(sap);
1887 if (hostsp != NULL) {
1888#ifdef CONFIG_AUDIT
1889 struct lsm_network_audit net;
1890
1891 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
1892 ad.a.u.net->family = sap->sin_family;
1893 ad.a.u.net->dport = sap->sin_port;
1894 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
1895#endif
1896 sk_lbl = SMACK_UNLABELED_SOCKET;
1897 skp = ssp->smk_out;
1898 rc = smk_access(skp, hostsp, MAY_WRITE, &ad);
1899 } else {
1900 sk_lbl = SMACK_CIPSO_SOCKET;
1901 rc = 0;
1902 }
1903 rcu_read_unlock();
1904 if (rc != 0)
1905 return rc;
1906
1907 return smack_netlabel(sk, sk_lbl);
1908}
1909
1910/**
1911 * smk_ipv6_port_label - Smack port access table management
1912 * @sock: socket
1913 * @address: address
1914 *
1915 * Create or update the port list entry
1916 */
1917static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
1918{
1919 struct sock *sk = sock->sk;
1920 struct sockaddr_in6 *addr6;
1921 struct socket_smack *ssp = sock->sk->sk_security;
1922 struct smk_port_label *spp;
1923 unsigned short port = 0;
1924
1925 if (address == NULL) {
1926 /*
1927 * This operation is changing the Smack information
1928 * on the bound socket. Take the changes to the port
1929 * as well.
1930 */
1931 list_for_each_entry(spp, &smk_ipv6_port_list, list) {
1932 if (sk != spp->smk_sock)
1933 continue;
1934 spp->smk_in = ssp->smk_in;
1935 spp->smk_out = ssp->smk_out;
1936 return;
1937 }
1938 /*
1939 * A NULL address is only used for updating existing
1940 * bound entries. If there isn't one, it's OK.
1941 */
1942 return;
1943 }
1944
1945 addr6 = (struct sockaddr_in6 *)address;
1946 port = ntohs(addr6->sin6_port);
1947 /*
1948 * This is a special case that is safely ignored.
1949 */
1950 if (port == 0)
1951 return;
1952
1953 /*
1954 * Look for an existing port list entry.
1955 * This is an indication that a port is getting reused.
1956 */
1957 list_for_each_entry(spp, &smk_ipv6_port_list, list) {
1958 if (spp->smk_port != port)
1959 continue;
1960 spp->smk_port = port;
1961 spp->smk_sock = sk;
1962 spp->smk_in = ssp->smk_in;
1963 spp->smk_out = ssp->smk_out;
1964 return;
1965 }
1966
1967 /*
1968 * A new port entry is required.
1969 */
1970 spp = kzalloc(sizeof(*spp), GFP_KERNEL);
1971 if (spp == NULL)
1972 return;
1973
1974 spp->smk_port = port;
1975 spp->smk_sock = sk;
1976 spp->smk_in = ssp->smk_in;
1977 spp->smk_out = ssp->smk_out;
1978
1979 list_add(&spp->list, &smk_ipv6_port_list);
1980 return;
1981}
1982
1983/**
1984 * smk_ipv6_port_check - check Smack port access
1985 * @sock: socket
1986 * @address: address
1987 *
1988 * Create or update the port list entry
1989 */
1990static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
1991 int act)
1992{
1993 __be16 *bep;
1994 __be32 *be32p;
1995 struct smk_port_label *spp;
1996 struct socket_smack *ssp = sk->sk_security;
1997 struct smack_known *skp;
1998 unsigned short port = 0;
1999 char *object;
2000 struct smk_audit_info ad;
2001#ifdef CONFIG_AUDIT
2002 struct lsm_network_audit net;
2003#endif
2004
2005 if (act == SMK_RECEIVING) {
2006 skp = smack_net_ambient;
2007 object = ssp->smk_in;
2008 } else {
2009 skp = ssp->smk_out;
2010 object = smack_net_ambient->smk_known;
2011 }
2012
2013 /*
2014 * Get the IP address and port from the address.
2015 */
2016 port = ntohs(address->sin6_port);
2017 bep = (__be16 *)(&address->sin6_addr);
2018 be32p = (__be32 *)(&address->sin6_addr);
2019
2020 /*
2021 * It's remote, so port lookup does no good.
2022 */
2023 if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1)
2024 goto auditout;
2025
2026 /*
2027 * It's local so the send check has to have passed.
2028 */
2029 if (act == SMK_RECEIVING) {
2030 skp = &smack_known_web;
2031 goto auditout;
2032 }
2033
2034 list_for_each_entry(spp, &smk_ipv6_port_list, list) {
2035 if (spp->smk_port != port)
2036 continue;
2037 object = spp->smk_in;
2038 if (act == SMK_CONNECTING)
2039 ssp->smk_packet = spp->smk_out->smk_known;
2040 break;
2041 }
2042
2043auditout:
2044
2045#ifdef CONFIG_AUDIT
2046 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2047 ad.a.u.net->family = sk->sk_family;
2048 ad.a.u.net->dport = port;
2049 if (act == SMK_RECEIVING)
2050 ad.a.u.net->v6info.saddr = address->sin6_addr;
2051 else
2052 ad.a.u.net->v6info.daddr = address->sin6_addr;
2053#endif
2054 return smk_access(skp, object, MAY_WRITE, &ad);
2055}
2056
2057/**
2058 * smack_inode_setsecurity - set smack xattrs
2059 * @inode: the object
2060 * @name: attribute name
2061 * @value: attribute value
2062 * @size: size of the attribute
2063 * @flags: unused
2064 *
2065 * Sets the named attribute in the appropriate blob
2066 *
2067 * Returns 0 on success, or an error code
2068 */
2069static int smack_inode_setsecurity(struct inode *inode, const char *name,
2070 const void *value, size_t size, int flags)
2071{
2072 struct smack_known *skp;
2073 struct inode_smack *nsp = inode->i_security;
2074 struct socket_smack *ssp;
2075 struct socket *sock;
2076 int rc = 0;
2077
2078 if (value == NULL || size > SMK_LONGLABEL || size == 0)
2079 return -EACCES;
2080
2081 skp = smk_import_entry(value, size);
2082 if (skp == NULL)
2083 return -EINVAL;
2084
2085 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2086 nsp->smk_inode = skp->smk_known;
2087 nsp->smk_flags |= SMK_INODE_INSTANT;
2088 return 0;
2089 }
2090 /*
2091 * The rest of the Smack xattrs are only on sockets.
2092 */
2093 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
2094 return -EOPNOTSUPP;
2095
2096 sock = SOCKET_I(inode);
2097 if (sock == NULL || sock->sk == NULL)
2098 return -EOPNOTSUPP;
2099
2100 ssp = sock->sk->sk_security;
2101
2102 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2103 ssp->smk_in = skp->smk_known;
2104 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2105 ssp->smk_out = skp;
2106 if (sock->sk->sk_family == PF_INET) {
2107 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
2108 if (rc != 0)
2109 printk(KERN_WARNING
2110 "Smack: \"%s\" netlbl error %d.\n",
2111 __func__, -rc);
2112 }
2113 } else
2114 return -EOPNOTSUPP;
2115
2116 if (sock->sk->sk_family == PF_INET6)
2117 smk_ipv6_port_label(sock, NULL);
2118
2119 return 0;
2120}
2121
2122/**
2123 * smack_socket_post_create - finish socket setup
2124 * @sock: the socket
2125 * @family: protocol family
2126 * @type: unused
2127 * @protocol: unused
2128 * @kern: unused
2129 *
2130 * Sets the netlabel information on the socket
2131 *
2132 * Returns 0 on success, and error code otherwise
2133 */
2134static int smack_socket_post_create(struct socket *sock, int family,
2135 int type, int protocol, int kern)
2136{
2137 if (family != PF_INET || sock->sk == NULL)
2138 return 0;
2139 /*
2140 * Set the outbound netlbl.
2141 */
2142 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
2143}
2144
2145/**
2146 * smack_socket_bind - record port binding information.
2147 * @sock: the socket
2148 * @address: the port address
2149 * @addrlen: size of the address
2150 *
2151 * Records the label bound to a port.
2152 *
2153 * Returns 0
2154 */
2155static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
2156 int addrlen)
2157{
2158 if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
2159 smk_ipv6_port_label(sock, address);
2160
2161 return 0;
2162}
2163
2164/**
2165 * smack_socket_connect - connect access check
2166 * @sock: the socket
2167 * @sap: the other end
2168 * @addrlen: size of sap
2169 *
2170 * Verifies that a connection may be possible
2171 *
2172 * Returns 0 on success, and error code otherwise
2173 */
2174static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2175 int addrlen)
2176{
2177 int rc = 0;
2178
2179 if (sock->sk == NULL)
2180 return 0;
2181
2182 switch (sock->sk->sk_family) {
2183 case PF_INET:
2184 if (addrlen < sizeof(struct sockaddr_in))
2185 return -EINVAL;
2186 rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2187 break;
2188 case PF_INET6:
2189 if (addrlen < sizeof(struct sockaddr_in6))
2190 return -EINVAL;
2191 rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
2192 SMK_CONNECTING);
2193 break;
2194 }
2195 return rc;
2196}
2197
2198/**
2199 * smack_flags_to_may - convert S_ to MAY_ values
2200 * @flags: the S_ value
2201 *
2202 * Returns the equivalent MAY_ value
2203 */
2204static int smack_flags_to_may(int flags)
2205{
2206 int may = 0;
2207
2208 if (flags & S_IRUGO)
2209 may |= MAY_READ;
2210 if (flags & S_IWUGO)
2211 may |= MAY_WRITE;
2212 if (flags & S_IXUGO)
2213 may |= MAY_EXEC;
2214
2215 return may;
2216}
2217
2218/**
2219 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2220 * @msg: the object
2221 *
2222 * Returns 0
2223 */
2224static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2225{
2226 struct smack_known *skp = smk_of_current();
2227
2228 msg->security = skp->smk_known;
2229 return 0;
2230}
2231
2232/**
2233 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2234 * @msg: the object
2235 *
2236 * Clears the blob pointer
2237 */
2238static void smack_msg_msg_free_security(struct msg_msg *msg)
2239{
2240 msg->security = NULL;
2241}
2242
2243/**
2244 * smack_of_shm - the smack pointer for the shm
2245 * @shp: the object
2246 *
2247 * Returns a pointer to the smack value
2248 */
2249static char *smack_of_shm(struct shmid_kernel *shp)
2250{
2251 return (char *)shp->shm_perm.security;
2252}
2253
2254/**
2255 * smack_shm_alloc_security - Set the security blob for shm
2256 * @shp: the object
2257 *
2258 * Returns 0
2259 */
2260static int smack_shm_alloc_security(struct shmid_kernel *shp)
2261{
2262 struct kern_ipc_perm *isp = &shp->shm_perm;
2263 struct smack_known *skp = smk_of_current();
2264
2265 isp->security = skp->smk_known;
2266 return 0;
2267}
2268
2269/**
2270 * smack_shm_free_security - Clear the security blob for shm
2271 * @shp: the object
2272 *
2273 * Clears the blob pointer
2274 */
2275static void smack_shm_free_security(struct shmid_kernel *shp)
2276{
2277 struct kern_ipc_perm *isp = &shp->shm_perm;
2278
2279 isp->security = NULL;
2280}
2281
2282/**
2283 * smk_curacc_shm : check if current has access on shm
2284 * @shp : the object
2285 * @access : access requested
2286 *
2287 * Returns 0 if current has the requested access, error code otherwise
2288 */
2289static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2290{
2291 char *ssp = smack_of_shm(shp);
2292 struct smk_audit_info ad;
2293
2294#ifdef CONFIG_AUDIT
2295 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2296 ad.a.u.ipc_id = shp->shm_perm.id;
2297#endif
2298 return smk_curacc(ssp, access, &ad);
2299}
2300
2301/**
2302 * smack_shm_associate - Smack access check for shm
2303 * @shp: the object
2304 * @shmflg: access requested
2305 *
2306 * Returns 0 if current has the requested access, error code otherwise
2307 */
2308static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2309{
2310 int may;
2311
2312 may = smack_flags_to_may(shmflg);
2313 return smk_curacc_shm(shp, may);
2314}
2315
2316/**
2317 * smack_shm_shmctl - Smack access check for shm
2318 * @shp: the object
2319 * @cmd: what it wants to do
2320 *
2321 * Returns 0 if current has the requested access, error code otherwise
2322 */
2323static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2324{
2325 int may;
2326
2327 switch (cmd) {
2328 case IPC_STAT:
2329 case SHM_STAT:
2330 may = MAY_READ;
2331 break;
2332 case IPC_SET:
2333 case SHM_LOCK:
2334 case SHM_UNLOCK:
2335 case IPC_RMID:
2336 may = MAY_READWRITE;
2337 break;
2338 case IPC_INFO:
2339 case SHM_INFO:
2340 /*
2341 * System level information.
2342 */
2343 return 0;
2344 default:
2345 return -EINVAL;
2346 }
2347 return smk_curacc_shm(shp, may);
2348}
2349
2350/**
2351 * smack_shm_shmat - Smack access for shmat
2352 * @shp: the object
2353 * @shmaddr: unused
2354 * @shmflg: access requested
2355 *
2356 * Returns 0 if current has the requested access, error code otherwise
2357 */
2358static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2359 int shmflg)
2360{
2361 int may;
2362
2363 may = smack_flags_to_may(shmflg);
2364 return smk_curacc_shm(shp, may);
2365}
2366
2367/**
2368 * smack_of_sem - the smack pointer for the sem
2369 * @sma: the object
2370 *
2371 * Returns a pointer to the smack value
2372 */
2373static char *smack_of_sem(struct sem_array *sma)
2374{
2375 return (char *)sma->sem_perm.security;
2376}
2377
2378/**
2379 * smack_sem_alloc_security - Set the security blob for sem
2380 * @sma: the object
2381 *
2382 * Returns 0
2383 */
2384static int smack_sem_alloc_security(struct sem_array *sma)
2385{
2386 struct kern_ipc_perm *isp = &sma->sem_perm;
2387 struct smack_known *skp = smk_of_current();
2388
2389 isp->security = skp->smk_known;
2390 return 0;
2391}
2392
2393/**
2394 * smack_sem_free_security - Clear the security blob for sem
2395 * @sma: the object
2396 *
2397 * Clears the blob pointer
2398 */
2399static void smack_sem_free_security(struct sem_array *sma)
2400{
2401 struct kern_ipc_perm *isp = &sma->sem_perm;
2402
2403 isp->security = NULL;
2404}
2405
2406/**
2407 * smk_curacc_sem : check if current has access on sem
2408 * @sma : the object
2409 * @access : access requested
2410 *
2411 * Returns 0 if current has the requested access, error code otherwise
2412 */
2413static int smk_curacc_sem(struct sem_array *sma, int access)
2414{
2415 char *ssp = smack_of_sem(sma);
2416 struct smk_audit_info ad;
2417
2418#ifdef CONFIG_AUDIT
2419 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2420 ad.a.u.ipc_id = sma->sem_perm.id;
2421#endif
2422 return smk_curacc(ssp, access, &ad);
2423}
2424
2425/**
2426 * smack_sem_associate - Smack access check for sem
2427 * @sma: the object
2428 * @semflg: access requested
2429 *
2430 * Returns 0 if current has the requested access, error code otherwise
2431 */
2432static int smack_sem_associate(struct sem_array *sma, int semflg)
2433{
2434 int may;
2435
2436 may = smack_flags_to_may(semflg);
2437 return smk_curacc_sem(sma, may);
2438}
2439
2440/**
2441 * smack_sem_shmctl - Smack access check for sem
2442 * @sma: the object
2443 * @cmd: what it wants to do
2444 *
2445 * Returns 0 if current has the requested access, error code otherwise
2446 */
2447static int smack_sem_semctl(struct sem_array *sma, int cmd)
2448{
2449 int may;
2450
2451 switch (cmd) {
2452 case GETPID:
2453 case GETNCNT:
2454 case GETZCNT:
2455 case GETVAL:
2456 case GETALL:
2457 case IPC_STAT:
2458 case SEM_STAT:
2459 may = MAY_READ;
2460 break;
2461 case SETVAL:
2462 case SETALL:
2463 case IPC_RMID:
2464 case IPC_SET:
2465 may = MAY_READWRITE;
2466 break;
2467 case IPC_INFO:
2468 case SEM_INFO:
2469 /*
2470 * System level information
2471 */
2472 return 0;
2473 default:
2474 return -EINVAL;
2475 }
2476
2477 return smk_curacc_sem(sma, may);
2478}
2479
2480/**
2481 * smack_sem_semop - Smack checks of semaphore operations
2482 * @sma: the object
2483 * @sops: unused
2484 * @nsops: unused
2485 * @alter: unused
2486 *
2487 * Treated as read and write in all cases.
2488 *
2489 * Returns 0 if access is allowed, error code otherwise
2490 */
2491static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2492 unsigned nsops, int alter)
2493{
2494 return smk_curacc_sem(sma, MAY_READWRITE);
2495}
2496
2497/**
2498 * smack_msg_alloc_security - Set the security blob for msg
2499 * @msq: the object
2500 *
2501 * Returns 0
2502 */
2503static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2504{
2505 struct kern_ipc_perm *kisp = &msq->q_perm;
2506 struct smack_known *skp = smk_of_current();
2507
2508 kisp->security = skp->smk_known;
2509 return 0;
2510}
2511
2512/**
2513 * smack_msg_free_security - Clear the security blob for msg
2514 * @msq: the object
2515 *
2516 * Clears the blob pointer
2517 */
2518static void smack_msg_queue_free_security(struct msg_queue *msq)
2519{
2520 struct kern_ipc_perm *kisp = &msq->q_perm;
2521
2522 kisp->security = NULL;
2523}
2524
2525/**
2526 * smack_of_msq - the smack pointer for the msq
2527 * @msq: the object
2528 *
2529 * Returns a pointer to the smack value
2530 */
2531static char *smack_of_msq(struct msg_queue *msq)
2532{
2533 return (char *)msq->q_perm.security;
2534}
2535
2536/**
2537 * smk_curacc_msq : helper to check if current has access on msq
2538 * @msq : the msq
2539 * @access : access requested
2540 *
2541 * return 0 if current has access, error otherwise
2542 */
2543static int smk_curacc_msq(struct msg_queue *msq, int access)
2544{
2545 char *msp = smack_of_msq(msq);
2546 struct smk_audit_info ad;
2547
2548#ifdef CONFIG_AUDIT
2549 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2550 ad.a.u.ipc_id = msq->q_perm.id;
2551#endif
2552 return smk_curacc(msp, access, &ad);
2553}
2554
2555/**
2556 * smack_msg_queue_associate - Smack access check for msg_queue
2557 * @msq: the object
2558 * @msqflg: access requested
2559 *
2560 * Returns 0 if current has the requested access, error code otherwise
2561 */
2562static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2563{
2564 int may;
2565
2566 may = smack_flags_to_may(msqflg);
2567 return smk_curacc_msq(msq, may);
2568}
2569
2570/**
2571 * smack_msg_queue_msgctl - Smack access check for msg_queue
2572 * @msq: the object
2573 * @cmd: what it wants to do
2574 *
2575 * Returns 0 if current has the requested access, error code otherwise
2576 */
2577static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2578{
2579 int may;
2580
2581 switch (cmd) {
2582 case IPC_STAT:
2583 case MSG_STAT:
2584 may = MAY_READ;
2585 break;
2586 case IPC_SET:
2587 case IPC_RMID:
2588 may = MAY_READWRITE;
2589 break;
2590 case IPC_INFO:
2591 case MSG_INFO:
2592 /*
2593 * System level information
2594 */
2595 return 0;
2596 default:
2597 return -EINVAL;
2598 }
2599
2600 return smk_curacc_msq(msq, may);
2601}
2602
2603/**
2604 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2605 * @msq: the object
2606 * @msg: unused
2607 * @msqflg: access requested
2608 *
2609 * Returns 0 if current has the requested access, error code otherwise
2610 */
2611static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2612 int msqflg)
2613{
2614 int may;
2615
2616 may = smack_flags_to_may(msqflg);
2617 return smk_curacc_msq(msq, may);
2618}
2619
2620/**
2621 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2622 * @msq: the object
2623 * @msg: unused
2624 * @target: unused
2625 * @type: unused
2626 * @mode: unused
2627 *
2628 * Returns 0 if current has read and write access, error code otherwise
2629 */
2630static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2631 struct task_struct *target, long type, int mode)
2632{
2633 return smk_curacc_msq(msq, MAY_READWRITE);
2634}
2635
2636/**
2637 * smack_ipc_permission - Smack access for ipc_permission()
2638 * @ipp: the object permissions
2639 * @flag: access requested
2640 *
2641 * Returns 0 if current has read and write access, error code otherwise
2642 */
2643static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2644{
2645 char *isp = ipp->security;
2646 int may = smack_flags_to_may(flag);
2647 struct smk_audit_info ad;
2648
2649#ifdef CONFIG_AUDIT
2650 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2651 ad.a.u.ipc_id = ipp->id;
2652#endif
2653 return smk_curacc(isp, may, &ad);
2654}
2655
2656/**
2657 * smack_ipc_getsecid - Extract smack security id
2658 * @ipp: the object permissions
2659 * @secid: where result will be saved
2660 */
2661static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2662{
2663 char *smack = ipp->security;
2664
2665 *secid = smack_to_secid(smack);
2666}
2667
2668/**
2669 * smack_d_instantiate - Make sure the blob is correct on an inode
2670 * @opt_dentry: dentry where inode will be attached
2671 * @inode: the object
2672 *
2673 * Set the inode's security blob if it hasn't been done already.
2674 */
2675static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2676{
2677 struct super_block *sbp;
2678 struct superblock_smack *sbsp;
2679 struct inode_smack *isp;
2680 struct smack_known *skp;
2681 struct smack_known *ckp = smk_of_current();
2682 char *final;
2683 char trattr[TRANS_TRUE_SIZE];
2684 int transflag = 0;
2685 int rc;
2686 struct dentry *dp;
2687
2688 if (inode == NULL)
2689 return;
2690
2691 isp = inode->i_security;
2692
2693 mutex_lock(&isp->smk_lock);
2694 /*
2695 * If the inode is already instantiated
2696 * take the quick way out
2697 */
2698 if (isp->smk_flags & SMK_INODE_INSTANT)
2699 goto unlockandout;
2700
2701 sbp = inode->i_sb;
2702 sbsp = sbp->s_security;
2703 /*
2704 * We're going to use the superblock default label
2705 * if there's no label on the file.
2706 */
2707 final = sbsp->smk_default;
2708
2709 /*
2710 * If this is the root inode the superblock
2711 * may be in the process of initialization.
2712 * If that is the case use the root value out
2713 * of the superblock.
2714 */
2715 if (opt_dentry->d_parent == opt_dentry) {
2716 isp->smk_inode = sbsp->smk_root;
2717 isp->smk_flags |= SMK_INODE_INSTANT;
2718 goto unlockandout;
2719 }
2720
2721 /*
2722 * This is pretty hackish.
2723 * Casey says that we shouldn't have to do
2724 * file system specific code, but it does help
2725 * with keeping it simple.
2726 */
2727 switch (sbp->s_magic) {
2728 case SMACK_MAGIC:
2729 /*
2730 * Casey says that it's a little embarrassing
2731 * that the smack file system doesn't do
2732 * extended attributes.
2733 */
2734 final = smack_known_star.smk_known;
2735 break;
2736 case PIPEFS_MAGIC:
2737 /*
2738 * Casey says pipes are easy (?)
2739 */
2740 final = smack_known_star.smk_known;
2741 break;
2742 case DEVPTS_SUPER_MAGIC:
2743 /*
2744 * devpts seems content with the label of the task.
2745 * Programs that change smack have to treat the
2746 * pty with respect.
2747 */
2748 final = ckp->smk_known;
2749 break;
2750 case SOCKFS_MAGIC:
2751 /*
2752 * Socket access is controlled by the socket
2753 * structures associated with the task involved.
2754 */
2755 final = smack_known_star.smk_known;
2756 break;
2757 case PROC_SUPER_MAGIC:
2758 /*
2759 * Casey says procfs appears not to care.
2760 * The superblock default suffices.
2761 */
2762 break;
2763 case TMPFS_MAGIC:
2764 /*
2765 * Device labels should come from the filesystem,
2766 * but watch out, because they're volitile,
2767 * getting recreated on every reboot.
2768 */
2769 final = smack_known_star.smk_known;
2770 /*
2771 * No break.
2772 *
2773 * If a smack value has been set we want to use it,
2774 * but since tmpfs isn't giving us the opportunity
2775 * to set mount options simulate setting the
2776 * superblock default.
2777 */
2778 default:
2779 /*
2780 * This isn't an understood special case.
2781 * Get the value from the xattr.
2782 */
2783
2784 /*
2785 * UNIX domain sockets use lower level socket data.
2786 */
2787 if (S_ISSOCK(inode->i_mode)) {
2788 final = smack_known_star.smk_known;
2789 break;
2790 }
2791 /*
2792 * No xattr support means, alas, no SMACK label.
2793 * Use the aforeapplied default.
2794 * It would be curious if the label of the task
2795 * does not match that assigned.
2796 */
2797 if (inode->i_op->getxattr == NULL)
2798 break;
2799 /*
2800 * Get the dentry for xattr.
2801 */
2802 dp = dget(opt_dentry);
2803 skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2804 if (skp != NULL)
2805 final = skp->smk_known;
2806
2807 /*
2808 * Transmuting directory
2809 */
2810 if (S_ISDIR(inode->i_mode)) {
2811 /*
2812 * If this is a new directory and the label was
2813 * transmuted when the inode was initialized
2814 * set the transmute attribute on the directory
2815 * and mark the inode.
2816 *
2817 * If there is a transmute attribute on the
2818 * directory mark the inode.
2819 */
2820 if (isp->smk_flags & SMK_INODE_CHANGED) {
2821 isp->smk_flags &= ~SMK_INODE_CHANGED;
2822 rc = inode->i_op->setxattr(dp,
2823 XATTR_NAME_SMACKTRANSMUTE,
2824 TRANS_TRUE, TRANS_TRUE_SIZE,
2825 0);
2826 } else {
2827 rc = inode->i_op->getxattr(dp,
2828 XATTR_NAME_SMACKTRANSMUTE, trattr,
2829 TRANS_TRUE_SIZE);
2830 if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
2831 TRANS_TRUE_SIZE) != 0)
2832 rc = -EINVAL;
2833 }
2834 if (rc >= 0)
2835 transflag = SMK_INODE_TRANSMUTE;
2836 }
2837 /*
2838 * Don't let the exec or mmap label be "*" or "@".
2839 */
2840 skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2841 if (skp == &smack_known_star || skp == &smack_known_web)
2842 skp = NULL;
2843 isp->smk_task = skp;
2844 skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2845 if (skp == &smack_known_star || skp == &smack_known_web)
2846 skp = NULL;
2847 isp->smk_mmap = skp;
2848
2849 dput(dp);
2850 break;
2851 }
2852
2853 if (final == NULL)
2854 isp->smk_inode = ckp->smk_known;
2855 else
2856 isp->smk_inode = final;
2857
2858 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2859
2860unlockandout:
2861 mutex_unlock(&isp->smk_lock);
2862 return;
2863}
2864
2865/**
2866 * smack_getprocattr - Smack process attribute access
2867 * @p: the object task
2868 * @name: the name of the attribute in /proc/.../attr
2869 * @value: where to put the result
2870 *
2871 * Places a copy of the task Smack into value
2872 *
2873 * Returns the length of the smack label or an error code
2874 */
2875static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2876{
2877 struct smack_known *skp = smk_of_task(task_security(p));
2878 char *cp;
2879 int slen;
2880
2881 if (strcmp(name, "current") != 0)
2882 return -EINVAL;
2883
2884 cp = kstrdup(skp->smk_known, GFP_KERNEL);
2885 if (cp == NULL)
2886 return -ENOMEM;
2887
2888 slen = strlen(cp);
2889 *value = cp;
2890 return slen;
2891}
2892
2893/**
2894 * smack_setprocattr - Smack process attribute setting
2895 * @p: the object task
2896 * @name: the name of the attribute in /proc/.../attr
2897 * @value: the value to set
2898 * @size: the size of the value
2899 *
2900 * Sets the Smack value of the task. Only setting self
2901 * is permitted and only with privilege
2902 *
2903 * Returns the length of the smack label or an error code
2904 */
2905static int smack_setprocattr(struct task_struct *p, char *name,
2906 void *value, size_t size)
2907{
2908 struct task_smack *tsp;
2909 struct cred *new;
2910 struct smack_known *skp;
2911
2912 /*
2913 * Changing another process' Smack value is too dangerous
2914 * and supports no sane use case.
2915 */
2916 if (p != current)
2917 return -EPERM;
2918
2919 if (!smack_privileged(CAP_MAC_ADMIN))
2920 return -EPERM;
2921
2922 if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
2923 return -EINVAL;
2924
2925 if (strcmp(name, "current") != 0)
2926 return -EINVAL;
2927
2928 skp = smk_import_entry(value, size);
2929 if (skp == NULL)
2930 return -EINVAL;
2931
2932 /*
2933 * No process is ever allowed the web ("@") label.
2934 */
2935 if (skp == &smack_known_web)
2936 return -EPERM;
2937
2938 new = prepare_creds();
2939 if (new == NULL)
2940 return -ENOMEM;
2941
2942 tsp = new->security;
2943 tsp->smk_task = skp;
2944
2945 commit_creds(new);
2946 return size;
2947}
2948
2949/**
2950 * smack_unix_stream_connect - Smack access on UDS
2951 * @sock: one sock
2952 * @other: the other sock
2953 * @newsk: unused
2954 *
2955 * Return 0 if a subject with the smack of sock could access
2956 * an object with the smack of other, otherwise an error code
2957 */
2958static int smack_unix_stream_connect(struct sock *sock,
2959 struct sock *other, struct sock *newsk)
2960{
2961 struct smack_known *skp;
2962 struct socket_smack *ssp = sock->sk_security;
2963 struct socket_smack *osp = other->sk_security;
2964 struct socket_smack *nsp = newsk->sk_security;
2965 struct smk_audit_info ad;
2966 int rc = 0;
2967
2968#ifdef CONFIG_AUDIT
2969 struct lsm_network_audit net;
2970
2971 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2972 smk_ad_setfield_u_net_sk(&ad, other);
2973#endif
2974
2975 if (!smack_privileged(CAP_MAC_OVERRIDE)) {
2976 skp = ssp->smk_out;
2977 rc = smk_access(skp, osp->smk_in, MAY_WRITE, &ad);
2978 }
2979
2980 /*
2981 * Cross reference the peer labels for SO_PEERSEC.
2982 */
2983 if (rc == 0) {
2984 nsp->smk_packet = ssp->smk_out->smk_known;
2985 ssp->smk_packet = osp->smk_out->smk_known;
2986 }
2987
2988 return rc;
2989}
2990
2991/**
2992 * smack_unix_may_send - Smack access on UDS
2993 * @sock: one socket
2994 * @other: the other socket
2995 *
2996 * Return 0 if a subject with the smack of sock could access
2997 * an object with the smack of other, otherwise an error code
2998 */
2999static int smack_unix_may_send(struct socket *sock, struct socket *other)
3000{
3001 struct socket_smack *ssp = sock->sk->sk_security;
3002 struct socket_smack *osp = other->sk->sk_security;
3003 struct smack_known *skp;
3004 struct smk_audit_info ad;
3005
3006#ifdef CONFIG_AUDIT
3007 struct lsm_network_audit net;
3008
3009 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3010 smk_ad_setfield_u_net_sk(&ad, other->sk);
3011#endif
3012
3013 if (smack_privileged(CAP_MAC_OVERRIDE))
3014 return 0;
3015
3016 skp = ssp->smk_out;
3017 return smk_access(skp, osp->smk_in, MAY_WRITE, &ad);
3018}
3019
3020/**
3021 * smack_socket_sendmsg - Smack check based on destination host
3022 * @sock: the socket
3023 * @msg: the message
3024 * @size: the size of the message
3025 *
3026 * Return 0 if the current subject can write to the destination host.
3027 * For IPv4 this is only a question if the destination is a single label host.
3028 * For IPv6 this is a check against the label of the port.
3029 */
3030static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3031 int size)
3032{
3033 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3034 struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3035 int rc = 0;
3036
3037 /*
3038 * Perfectly reasonable for this to be NULL
3039 */
3040 if (sip == NULL)
3041 return 0;
3042
3043 switch (sip->sin_family) {
3044 case AF_INET:
3045 rc = smack_netlabel_send(sock->sk, sip);
3046 break;
3047 case AF_INET6:
3048 rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3049 break;
3050 }
3051 return rc;
3052}
3053
3054/**
3055 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3056 * @sap: netlabel secattr
3057 * @ssp: socket security information
3058 *
3059 * Returns a pointer to a Smack label entry found on the label list.
3060 */
3061static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
3062 struct socket_smack *ssp)
3063{
3064 struct smack_known *skp;
3065 int found = 0;
3066 int acat;
3067 int kcat;
3068
3069 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3070 /*
3071 * Looks like a CIPSO packet.
3072 * If there are flags but no level netlabel isn't
3073 * behaving the way we expect it to.
3074 *
3075 * Look it up in the label table
3076 * Without guidance regarding the smack value
3077 * for the packet fall back on the network
3078 * ambient value.
3079 */
3080 rcu_read_lock();
3081 list_for_each_entry(skp, &smack_known_list, list) {
3082 if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3083 continue;
3084 /*
3085 * Compare the catsets. Use the netlbl APIs.
3086 */
3087 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
3088 if ((skp->smk_netlabel.flags &
3089 NETLBL_SECATTR_MLS_CAT) == 0)
3090 found = 1;
3091 break;
3092 }
3093 for (acat = -1, kcat = -1; acat == kcat; ) {
3094 acat = netlbl_secattr_catmap_walk(
3095 sap->attr.mls.cat, acat + 1);
3096 kcat = netlbl_secattr_catmap_walk(
3097 skp->smk_netlabel.attr.mls.cat,
3098 kcat + 1);
3099 if (acat < 0 || kcat < 0)
3100 break;
3101 }
3102 if (acat == kcat) {
3103 found = 1;
3104 break;
3105 }
3106 }
3107 rcu_read_unlock();
3108
3109 if (found)
3110 return skp;
3111
3112 if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
3113 return &smack_known_web;
3114 return &smack_known_star;
3115 }
3116 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
3117 /*
3118 * Looks like a fallback, which gives us a secid.
3119 */
3120 skp = smack_from_secid(sap->attr.secid);
3121 /*
3122 * This has got to be a bug because it is
3123 * impossible to specify a fallback without
3124 * specifying the label, which will ensure
3125 * it has a secid, and the only way to get a
3126 * secid is from a fallback.
3127 */
3128 BUG_ON(skp == NULL);
3129 return skp;
3130 }
3131 /*
3132 * Without guidance regarding the smack value
3133 * for the packet fall back on the network
3134 * ambient value.
3135 */
3136 return smack_net_ambient;
3137}
3138
3139static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3140{
3141 u8 nexthdr;
3142 int offset;
3143 int proto = -EINVAL;
3144 struct ipv6hdr _ipv6h;
3145 struct ipv6hdr *ip6;
3146 __be16 frag_off;
3147 struct tcphdr _tcph, *th;
3148 struct udphdr _udph, *uh;
3149 struct dccp_hdr _dccph, *dh;
3150
3151 sip->sin6_port = 0;
3152
3153 offset = skb_network_offset(skb);
3154 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3155 if (ip6 == NULL)
3156 return -EINVAL;
3157 sip->sin6_addr = ip6->saddr;
3158
3159 nexthdr = ip6->nexthdr;
3160 offset += sizeof(_ipv6h);
3161 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3162 if (offset < 0)
3163 return -EINVAL;
3164
3165 proto = nexthdr;
3166 switch (proto) {
3167 case IPPROTO_TCP:
3168 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3169 if (th != NULL)
3170 sip->sin6_port = th->source;
3171 break;
3172 case IPPROTO_UDP:
3173 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3174 if (uh != NULL)
3175 sip->sin6_port = uh->source;
3176 break;
3177 case IPPROTO_DCCP:
3178 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3179 if (dh != NULL)
3180 sip->sin6_port = dh->dccph_sport;
3181 break;
3182 }
3183 return proto;
3184}
3185
3186/**
3187 * smack_socket_sock_rcv_skb - Smack packet delivery access check
3188 * @sk: socket
3189 * @skb: packet
3190 *
3191 * Returns 0 if the packet should be delivered, an error code otherwise
3192 */
3193static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
3194{
3195 struct netlbl_lsm_secattr secattr;
3196 struct socket_smack *ssp = sk->sk_security;
3197 struct smack_known *skp;
3198 struct sockaddr_in6 sadd;
3199 int rc = 0;
3200 struct smk_audit_info ad;
3201#ifdef CONFIG_AUDIT
3202 struct lsm_network_audit net;
3203#endif
3204 switch (sk->sk_family) {
3205 case PF_INET:
3206 /*
3207 * Translate what netlabel gave us.
3208 */
3209 netlbl_secattr_init(&secattr);
3210
3211 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
3212 if (rc == 0)
3213 skp = smack_from_secattr(&secattr, ssp);
3214 else
3215 skp = smack_net_ambient;
3216
3217 netlbl_secattr_destroy(&secattr);
3218
3219#ifdef CONFIG_AUDIT
3220 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3221 ad.a.u.net->family = sk->sk_family;
3222 ad.a.u.net->netif = skb->skb_iif;
3223 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3224#endif
3225 /*
3226 * Receiving a packet requires that the other end
3227 * be able to write here. Read access is not required.
3228 * This is the simplist possible security model
3229 * for networking.
3230 */
3231 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
3232 if (rc != 0)
3233 netlbl_skbuff_err(skb, rc, 0);
3234 break;
3235 case PF_INET6:
3236 rc = smk_skb_to_addr_ipv6(skb, &sadd);
3237 if (rc == IPPROTO_UDP || rc == IPPROTO_TCP)
3238 rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
3239 else
3240 rc = 0;
3241 break;
3242 }
3243 return rc;
3244}
3245
3246/**
3247 * smack_socket_getpeersec_stream - pull in packet label
3248 * @sock: the socket
3249 * @optval: user's destination
3250 * @optlen: size thereof
3251 * @len: max thereof
3252 *
3253 * returns zero on success, an error code otherwise
3254 */
3255static int smack_socket_getpeersec_stream(struct socket *sock,
3256 char __user *optval,
3257 int __user *optlen, unsigned len)
3258{
3259 struct socket_smack *ssp;
3260 char *rcp = "";
3261 int slen = 1;
3262 int rc = 0;
3263
3264 ssp = sock->sk->sk_security;
3265 if (ssp->smk_packet != NULL) {
3266 rcp = ssp->smk_packet;
3267 slen = strlen(rcp) + 1;
3268 }
3269
3270 if (slen > len)
3271 rc = -ERANGE;
3272 else if (copy_to_user(optval, rcp, slen) != 0)
3273 rc = -EFAULT;
3274
3275 if (put_user(slen, optlen) != 0)
3276 rc = -EFAULT;
3277
3278 return rc;
3279}
3280
3281
3282/**
3283 * smack_socket_getpeersec_dgram - pull in packet label
3284 * @sock: the peer socket
3285 * @skb: packet data
3286 * @secid: pointer to where to put the secid of the packet
3287 *
3288 * Sets the netlabel socket state on sk from parent
3289 */
3290static int smack_socket_getpeersec_dgram(struct socket *sock,
3291 struct sk_buff *skb, u32 *secid)
3292
3293{
3294 struct netlbl_lsm_secattr secattr;
3295 struct socket_smack *ssp = NULL;
3296 struct smack_known *skp;
3297 int family = PF_UNSPEC;
3298 u32 s = 0; /* 0 is the invalid secid */
3299 int rc;
3300
3301 if (skb != NULL) {
3302 if (skb->protocol == htons(ETH_P_IP))
3303 family = PF_INET;
3304 else if (skb->protocol == htons(ETH_P_IPV6))
3305 family = PF_INET6;
3306 }
3307 if (family == PF_UNSPEC && sock != NULL)
3308 family = sock->sk->sk_family;
3309
3310 if (family == PF_UNIX) {
3311 ssp = sock->sk->sk_security;
3312 s = ssp->smk_out->smk_secid;
3313 } else if (family == PF_INET || family == PF_INET6) {
3314 /*
3315 * Translate what netlabel gave us.
3316 */
3317 if (sock != NULL && sock->sk != NULL)
3318 ssp = sock->sk->sk_security;
3319 netlbl_secattr_init(&secattr);
3320 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3321 if (rc == 0) {
3322 skp = smack_from_secattr(&secattr, ssp);
3323 s = skp->smk_secid;
3324 }
3325 netlbl_secattr_destroy(&secattr);
3326 }
3327 *secid = s;
3328 if (s == 0)
3329 return -EINVAL;
3330 return 0;
3331}
3332
3333/**
3334 * smack_sock_graft - Initialize a newly created socket with an existing sock
3335 * @sk: child sock
3336 * @parent: parent socket
3337 *
3338 * Set the smk_{in,out} state of an existing sock based on the process that
3339 * is creating the new socket.
3340 */
3341static void smack_sock_graft(struct sock *sk, struct socket *parent)
3342{
3343 struct socket_smack *ssp;
3344 struct smack_known *skp = smk_of_current();
3345
3346 if (sk == NULL ||
3347 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3348 return;
3349
3350 ssp = sk->sk_security;
3351 ssp->smk_in = skp->smk_known;
3352 ssp->smk_out = skp;
3353 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3354}
3355
3356/**
3357 * smack_inet_conn_request - Smack access check on connect
3358 * @sk: socket involved
3359 * @skb: packet
3360 * @req: unused
3361 *
3362 * Returns 0 if a task with the packet label could write to
3363 * the socket, otherwise an error code
3364 */
3365static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3366 struct request_sock *req)
3367{
3368 u16 family = sk->sk_family;
3369 struct smack_known *skp;
3370 struct socket_smack *ssp = sk->sk_security;
3371 struct netlbl_lsm_secattr secattr;
3372 struct sockaddr_in addr;
3373 struct iphdr *hdr;
3374 char *hsp;
3375 int rc;
3376 struct smk_audit_info ad;
3377#ifdef CONFIG_AUDIT
3378 struct lsm_network_audit net;
3379#endif
3380
3381 if (family == PF_INET6) {
3382 /*
3383 * Handle mapped IPv4 packets arriving
3384 * via IPv6 sockets. Don't set up netlabel
3385 * processing on IPv6.
3386 */
3387 if (skb->protocol == htons(ETH_P_IP))
3388 family = PF_INET;
3389 else
3390 return 0;
3391 }
3392
3393 netlbl_secattr_init(&secattr);
3394 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3395 if (rc == 0)
3396 skp = smack_from_secattr(&secattr, ssp);
3397 else
3398 skp = &smack_known_huh;
3399 netlbl_secattr_destroy(&secattr);
3400
3401#ifdef CONFIG_AUDIT
3402 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3403 ad.a.u.net->family = family;
3404 ad.a.u.net->netif = skb->skb_iif;
3405 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3406#endif
3407 /*
3408 * Receiving a packet requires that the other end be able to write
3409 * here. Read access is not required.
3410 */
3411 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
3412 if (rc != 0)
3413 return rc;
3414
3415 /*
3416 * Save the peer's label in the request_sock so we can later setup
3417 * smk_packet in the child socket so that SO_PEERCRED can report it.
3418 */
3419 req->peer_secid = skp->smk_secid;
3420
3421 /*
3422 * We need to decide if we want to label the incoming connection here
3423 * if we do we only need to label the request_sock and the stack will
3424 * propagate the wire-label to the sock when it is created.
3425 */
3426 hdr = ip_hdr(skb);
3427 addr.sin_addr.s_addr = hdr->saddr;
3428 rcu_read_lock();
3429 hsp = smack_host_label(&addr);
3430 rcu_read_unlock();
3431
3432 if (hsp == NULL)
3433 rc = netlbl_req_setattr(req, &skp->smk_netlabel);
3434 else
3435 netlbl_req_delattr(req);
3436
3437 return rc;
3438}
3439
3440/**
3441 * smack_inet_csk_clone - Copy the connection information to the new socket
3442 * @sk: the new socket
3443 * @req: the connection's request_sock
3444 *
3445 * Transfer the connection's peer label to the newly created socket.
3446 */
3447static void smack_inet_csk_clone(struct sock *sk,
3448 const struct request_sock *req)
3449{
3450 struct socket_smack *ssp = sk->sk_security;
3451 struct smack_known *skp;
3452
3453 if (req->peer_secid != 0) {
3454 skp = smack_from_secid(req->peer_secid);
3455 ssp->smk_packet = skp->smk_known;
3456 } else
3457 ssp->smk_packet = NULL;
3458}
3459
3460/*
3461 * Key management security hooks
3462 *
3463 * Casey has not tested key support very heavily.
3464 * The permission check is most likely too restrictive.
3465 * If you care about keys please have a look.
3466 */
3467#ifdef CONFIG_KEYS
3468
3469/**
3470 * smack_key_alloc - Set the key security blob
3471 * @key: object
3472 * @cred: the credentials to use
3473 * @flags: unused
3474 *
3475 * No allocation required
3476 *
3477 * Returns 0
3478 */
3479static int smack_key_alloc(struct key *key, const struct cred *cred,
3480 unsigned long flags)
3481{
3482 struct smack_known *skp = smk_of_task(cred->security);
3483
3484 key->security = skp->smk_known;
3485 return 0;
3486}
3487
3488/**
3489 * smack_key_free - Clear the key security blob
3490 * @key: the object
3491 *
3492 * Clear the blob pointer
3493 */
3494static void smack_key_free(struct key *key)
3495{
3496 key->security = NULL;
3497}
3498
3499/*
3500 * smack_key_permission - Smack access on a key
3501 * @key_ref: gets to the object
3502 * @cred: the credentials to use
3503 * @perm: unused
3504 *
3505 * Return 0 if the task has read and write to the object,
3506 * an error code otherwise
3507 */
3508static int smack_key_permission(key_ref_t key_ref,
3509 const struct cred *cred, key_perm_t perm)
3510{
3511 struct key *keyp;
3512 struct smk_audit_info ad;
3513 struct smack_known *tkp = smk_of_task(cred->security);
3514
3515 keyp = key_ref_to_ptr(key_ref);
3516 if (keyp == NULL)
3517 return -EINVAL;
3518 /*
3519 * If the key hasn't been initialized give it access so that
3520 * it may do so.
3521 */
3522 if (keyp->security == NULL)
3523 return 0;
3524 /*
3525 * This should not occur
3526 */
3527 if (tkp == NULL)
3528 return -EACCES;
3529#ifdef CONFIG_AUDIT
3530 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3531 ad.a.u.key_struct.key = keyp->serial;
3532 ad.a.u.key_struct.key_desc = keyp->description;
3533#endif
3534 return smk_access(tkp, keyp->security, MAY_READWRITE, &ad);
3535}
3536#endif /* CONFIG_KEYS */
3537
3538/*
3539 * Smack Audit hooks
3540 *
3541 * Audit requires a unique representation of each Smack specific
3542 * rule. This unique representation is used to distinguish the
3543 * object to be audited from remaining kernel objects and also
3544 * works as a glue between the audit hooks.
3545 *
3546 * Since repository entries are added but never deleted, we'll use
3547 * the smack_known label address related to the given audit rule as
3548 * the needed unique representation. This also better fits the smack
3549 * model where nearly everything is a label.
3550 */
3551#ifdef CONFIG_AUDIT
3552
3553/**
3554 * smack_audit_rule_init - Initialize a smack audit rule
3555 * @field: audit rule fields given from user-space (audit.h)
3556 * @op: required testing operator (=, !=, >, <, ...)
3557 * @rulestr: smack label to be audited
3558 * @vrule: pointer to save our own audit rule representation
3559 *
3560 * Prepare to audit cases where (@field @op @rulestr) is true.
3561 * The label to be audited is created if necessay.
3562 */
3563static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3564{
3565 char **rule = (char **)vrule;
3566 *rule = NULL;
3567
3568 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3569 return -EINVAL;
3570
3571 if (op != Audit_equal && op != Audit_not_equal)
3572 return -EINVAL;
3573
3574 *rule = smk_import(rulestr, 0);
3575
3576 return 0;
3577}
3578
3579/**
3580 * smack_audit_rule_known - Distinguish Smack audit rules
3581 * @krule: rule of interest, in Audit kernel representation format
3582 *
3583 * This is used to filter Smack rules from remaining Audit ones.
3584 * If it's proved that this rule belongs to us, the
3585 * audit_rule_match hook will be called to do the final judgement.
3586 */
3587static int smack_audit_rule_known(struct audit_krule *krule)
3588{
3589 struct audit_field *f;
3590 int i;
3591
3592 for (i = 0; i < krule->field_count; i++) {
3593 f = &krule->fields[i];
3594
3595 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3596 return 1;
3597 }
3598
3599 return 0;
3600}
3601
3602/**
3603 * smack_audit_rule_match - Audit given object ?
3604 * @secid: security id for identifying the object to test
3605 * @field: audit rule flags given from user-space
3606 * @op: required testing operator
3607 * @vrule: smack internal rule presentation
3608 * @actx: audit context associated with the check
3609 *
3610 * The core Audit hook. It's used to take the decision of
3611 * whether to audit or not to audit a given object.
3612 */
3613static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3614 struct audit_context *actx)
3615{
3616 struct smack_known *skp;
3617 char *rule = vrule;
3618
3619 if (unlikely(!rule)) {
3620 WARN_ONCE(1, "Smack: missing rule\n");
3621 return -ENOENT;
3622 }
3623
3624 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3625 return 0;
3626
3627 skp = smack_from_secid(secid);
3628
3629 /*
3630 * No need to do string comparisons. If a match occurs,
3631 * both pointers will point to the same smack_known
3632 * label.
3633 */
3634 if (op == Audit_equal)
3635 return (rule == skp->smk_known);
3636 if (op == Audit_not_equal)
3637 return (rule != skp->smk_known);
3638
3639 return 0;
3640}
3641
3642/**
3643 * smack_audit_rule_free - free smack rule representation
3644 * @vrule: rule to be freed.
3645 *
3646 * No memory was allocated.
3647 */
3648static void smack_audit_rule_free(void *vrule)
3649{
3650 /* No-op */
3651}
3652
3653#endif /* CONFIG_AUDIT */
3654
3655/**
3656 * smack_ismaclabel - check if xattr @name references a smack MAC label
3657 * @name: Full xattr name to check.
3658 */
3659static int smack_ismaclabel(const char *name)
3660{
3661 return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
3662}
3663
3664
3665/**
3666 * smack_secid_to_secctx - return the smack label for a secid
3667 * @secid: incoming integer
3668 * @secdata: destination
3669 * @seclen: how long it is
3670 *
3671 * Exists for networking code.
3672 */
3673static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3674{
3675 struct smack_known *skp = smack_from_secid(secid);
3676
3677 if (secdata)
3678 *secdata = skp->smk_known;
3679 *seclen = strlen(skp->smk_known);
3680 return 0;
3681}
3682
3683/**
3684 * smack_secctx_to_secid - return the secid for a smack label
3685 * @secdata: smack label
3686 * @seclen: how long result is
3687 * @secid: outgoing integer
3688 *
3689 * Exists for audit and networking code.
3690 */
3691static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3692{
3693 *secid = smack_to_secid(secdata);
3694 return 0;
3695}
3696
3697/**
3698 * smack_release_secctx - don't do anything.
3699 * @secdata: unused
3700 * @seclen: unused
3701 *
3702 * Exists to make sure nothing gets done, and properly
3703 */
3704static void smack_release_secctx(char *secdata, u32 seclen)
3705{
3706}
3707
3708static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3709{
3710 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3711}
3712
3713static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3714{
3715 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3716}
3717
3718static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3719{
3720 int len = 0;
3721 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3722
3723 if (len < 0)
3724 return len;
3725 *ctxlen = len;
3726 return 0;
3727}
3728
3729struct security_operations smack_ops = {
3730 .name = "smack",
3731
3732 .ptrace_access_check = smack_ptrace_access_check,
3733 .ptrace_traceme = smack_ptrace_traceme,
3734 .syslog = smack_syslog,
3735
3736 .sb_alloc_security = smack_sb_alloc_security,
3737 .sb_free_security = smack_sb_free_security,
3738 .sb_copy_data = smack_sb_copy_data,
3739 .sb_kern_mount = smack_sb_kern_mount,
3740 .sb_statfs = smack_sb_statfs,
3741
3742 .bprm_set_creds = smack_bprm_set_creds,
3743 .bprm_committing_creds = smack_bprm_committing_creds,
3744 .bprm_secureexec = smack_bprm_secureexec,
3745
3746 .inode_alloc_security = smack_inode_alloc_security,
3747 .inode_free_security = smack_inode_free_security,
3748 .inode_init_security = smack_inode_init_security,
3749 .inode_link = smack_inode_link,
3750 .inode_unlink = smack_inode_unlink,
3751 .inode_rmdir = smack_inode_rmdir,
3752 .inode_rename = smack_inode_rename,
3753 .inode_permission = smack_inode_permission,
3754 .inode_setattr = smack_inode_setattr,
3755 .inode_getattr = smack_inode_getattr,
3756 .inode_setxattr = smack_inode_setxattr,
3757 .inode_post_setxattr = smack_inode_post_setxattr,
3758 .inode_getxattr = smack_inode_getxattr,
3759 .inode_removexattr = smack_inode_removexattr,
3760 .inode_getsecurity = smack_inode_getsecurity,
3761 .inode_setsecurity = smack_inode_setsecurity,
3762 .inode_listsecurity = smack_inode_listsecurity,
3763 .inode_getsecid = smack_inode_getsecid,
3764
3765 .file_permission = smack_file_permission,
3766 .file_alloc_security = smack_file_alloc_security,
3767 .file_free_security = smack_file_free_security,
3768 .file_ioctl = smack_file_ioctl,
3769 .file_lock = smack_file_lock,
3770 .file_fcntl = smack_file_fcntl,
3771 .mmap_file = smack_mmap_file,
3772 .mmap_addr = cap_mmap_addr,
3773 .file_set_fowner = smack_file_set_fowner,
3774 .file_send_sigiotask = smack_file_send_sigiotask,
3775 .file_receive = smack_file_receive,
3776
3777 .file_open = smack_file_open,
3778
3779 .cred_alloc_blank = smack_cred_alloc_blank,
3780 .cred_free = smack_cred_free,
3781 .cred_prepare = smack_cred_prepare,
3782 .cred_transfer = smack_cred_transfer,
3783 .kernel_act_as = smack_kernel_act_as,
3784 .kernel_create_files_as = smack_kernel_create_files_as,
3785 .task_setpgid = smack_task_setpgid,
3786 .task_getpgid = smack_task_getpgid,
3787 .task_getsid = smack_task_getsid,
3788 .task_getsecid = smack_task_getsecid,
3789 .task_setnice = smack_task_setnice,
3790 .task_setioprio = smack_task_setioprio,
3791 .task_getioprio = smack_task_getioprio,
3792 .task_setscheduler = smack_task_setscheduler,
3793 .task_getscheduler = smack_task_getscheduler,
3794 .task_movememory = smack_task_movememory,
3795 .task_kill = smack_task_kill,
3796 .task_wait = smack_task_wait,
3797 .task_to_inode = smack_task_to_inode,
3798
3799 .ipc_permission = smack_ipc_permission,
3800 .ipc_getsecid = smack_ipc_getsecid,
3801
3802 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
3803 .msg_msg_free_security = smack_msg_msg_free_security,
3804
3805 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
3806 .msg_queue_free_security = smack_msg_queue_free_security,
3807 .msg_queue_associate = smack_msg_queue_associate,
3808 .msg_queue_msgctl = smack_msg_queue_msgctl,
3809 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
3810 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
3811
3812 .shm_alloc_security = smack_shm_alloc_security,
3813 .shm_free_security = smack_shm_free_security,
3814 .shm_associate = smack_shm_associate,
3815 .shm_shmctl = smack_shm_shmctl,
3816 .shm_shmat = smack_shm_shmat,
3817
3818 .sem_alloc_security = smack_sem_alloc_security,
3819 .sem_free_security = smack_sem_free_security,
3820 .sem_associate = smack_sem_associate,
3821 .sem_semctl = smack_sem_semctl,
3822 .sem_semop = smack_sem_semop,
3823
3824 .d_instantiate = smack_d_instantiate,
3825
3826 .getprocattr = smack_getprocattr,
3827 .setprocattr = smack_setprocattr,
3828
3829 .unix_stream_connect = smack_unix_stream_connect,
3830 .unix_may_send = smack_unix_may_send,
3831
3832 .socket_post_create = smack_socket_post_create,
3833 .socket_bind = smack_socket_bind,
3834 .socket_connect = smack_socket_connect,
3835 .socket_sendmsg = smack_socket_sendmsg,
3836 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
3837 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
3838 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
3839 .sk_alloc_security = smack_sk_alloc_security,
3840 .sk_free_security = smack_sk_free_security,
3841 .sock_graft = smack_sock_graft,
3842 .inet_conn_request = smack_inet_conn_request,
3843 .inet_csk_clone = smack_inet_csk_clone,
3844
3845 /* key management security hooks */
3846#ifdef CONFIG_KEYS
3847 .key_alloc = smack_key_alloc,
3848 .key_free = smack_key_free,
3849 .key_permission = smack_key_permission,
3850#endif /* CONFIG_KEYS */
3851
3852 /* Audit hooks */
3853#ifdef CONFIG_AUDIT
3854 .audit_rule_init = smack_audit_rule_init,
3855 .audit_rule_known = smack_audit_rule_known,
3856 .audit_rule_match = smack_audit_rule_match,
3857 .audit_rule_free = smack_audit_rule_free,
3858#endif /* CONFIG_AUDIT */
3859
3860 .ismaclabel = smack_ismaclabel,
3861 .secid_to_secctx = smack_secid_to_secctx,
3862 .secctx_to_secid = smack_secctx_to_secid,
3863 .release_secctx = smack_release_secctx,
3864 .inode_notifysecctx = smack_inode_notifysecctx,
3865 .inode_setsecctx = smack_inode_setsecctx,
3866 .inode_getsecctx = smack_inode_getsecctx,
3867};
3868
3869
3870static __init void init_smack_known_list(void)
3871{
3872 /*
3873 * Initialize rule list locks
3874 */
3875 mutex_init(&smack_known_huh.smk_rules_lock);
3876 mutex_init(&smack_known_hat.smk_rules_lock);
3877 mutex_init(&smack_known_floor.smk_rules_lock);
3878 mutex_init(&smack_known_star.smk_rules_lock);
3879 mutex_init(&smack_known_invalid.smk_rules_lock);
3880 mutex_init(&smack_known_web.smk_rules_lock);
3881 /*
3882 * Initialize rule lists
3883 */
3884 INIT_LIST_HEAD(&smack_known_huh.smk_rules);
3885 INIT_LIST_HEAD(&smack_known_hat.smk_rules);
3886 INIT_LIST_HEAD(&smack_known_star.smk_rules);
3887 INIT_LIST_HEAD(&smack_known_floor.smk_rules);
3888 INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
3889 INIT_LIST_HEAD(&smack_known_web.smk_rules);
3890 /*
3891 * Create the known labels list
3892 */
3893 smk_insert_entry(&smack_known_huh);
3894 smk_insert_entry(&smack_known_hat);
3895 smk_insert_entry(&smack_known_star);
3896 smk_insert_entry(&smack_known_floor);
3897 smk_insert_entry(&smack_known_invalid);
3898 smk_insert_entry(&smack_known_web);
3899}
3900
3901/**
3902 * smack_init - initialize the smack system
3903 *
3904 * Returns 0
3905 */
3906static __init int smack_init(void)
3907{
3908 struct cred *cred;
3909 struct task_smack *tsp;
3910
3911 if (!security_module_enable(&smack_ops))
3912 return 0;
3913
3914 tsp = new_task_smack(&smack_known_floor, &smack_known_floor,
3915 GFP_KERNEL);
3916 if (tsp == NULL)
3917 return -ENOMEM;
3918
3919 printk(KERN_INFO "Smack: Initializing.\n");
3920
3921 /*
3922 * Set the security state for the initial task.
3923 */
3924 cred = (struct cred *) current->cred;
3925 cred->security = tsp;
3926
3927 /* initialize the smack_known_list */
3928 init_smack_known_list();
3929
3930 /*
3931 * Register with LSM
3932 */
3933 if (register_security(&smack_ops))
3934 panic("smack: Unable to register with kernel.\n");
3935
3936 return 0;
3937}
3938
3939/*
3940 * Smack requires early initialization in order to label
3941 * all processes and objects when they are created.
3942 */
3943security_initcall(smack_init);