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