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awilliam
GitHub Repository: awilliam/linux-vfio
Path: blob/master/security/smack/smack_lsm.c
10814 views
1
/*
2
* Simplified MAC Kernel (smack) security module
3
*
4
* This file contains the smack hook function implementations.
5
*
6
* Authors:
7
* Casey Schaufler <[email protected]>
8
* Jarkko Sakkinen <[email protected]>
9
*
10
* Copyright (C) 2007 Casey Schaufler <[email protected]>
11
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
12
* Paul Moore <[email protected]>
13
* Copyright (C) 2010 Nokia Corporation
14
*
15
* This program is free software; you can redistribute it and/or modify
16
* it under the terms of the GNU General Public License version 2,
17
* as published by the Free Software Foundation.
18
*/
19
20
#include <linux/xattr.h>
21
#include <linux/pagemap.h>
22
#include <linux/mount.h>
23
#include <linux/stat.h>
24
#include <linux/kd.h>
25
#include <asm/ioctls.h>
26
#include <linux/ip.h>
27
#include <linux/tcp.h>
28
#include <linux/udp.h>
29
#include <linux/slab.h>
30
#include <linux/mutex.h>
31
#include <linux/pipe_fs_i.h>
32
#include <net/netlabel.h>
33
#include <net/cipso_ipv4.h>
34
#include <linux/audit.h>
35
#include <linux/magic.h>
36
#include <linux/dcache.h>
37
#include "smack.h"
38
39
#define task_security(task) (task_cred_xxx((task), security))
40
41
#define TRANS_TRUE "TRUE"
42
#define TRANS_TRUE_SIZE 4
43
44
/**
45
* smk_fetch - Fetch the smack label from a file.
46
* @ip: a pointer to the inode
47
* @dp: a pointer to the dentry
48
*
49
* Returns a pointer to the master list entry for the Smack label
50
* or NULL if there was no label to fetch.
51
*/
52
static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
53
{
54
int rc;
55
char in[SMK_LABELLEN];
56
57
if (ip->i_op->getxattr == NULL)
58
return NULL;
59
60
rc = ip->i_op->getxattr(dp, name, in, SMK_LABELLEN);
61
if (rc < 0)
62
return NULL;
63
64
return smk_import(in, rc);
65
}
66
67
/**
68
* new_inode_smack - allocate an inode security blob
69
* @smack: a pointer to the Smack label to use in the blob
70
*
71
* Returns the new blob or NULL if there's no memory available
72
*/
73
struct inode_smack *new_inode_smack(char *smack)
74
{
75
struct inode_smack *isp;
76
77
isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
78
if (isp == NULL)
79
return NULL;
80
81
isp->smk_inode = smack;
82
isp->smk_flags = 0;
83
mutex_init(&isp->smk_lock);
84
85
return isp;
86
}
87
88
/**
89
* new_task_smack - allocate a task security blob
90
* @smack: a pointer to the Smack label to use in the blob
91
*
92
* Returns the new blob or NULL if there's no memory available
93
*/
94
static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
95
{
96
struct task_smack *tsp;
97
98
tsp = kzalloc(sizeof(struct task_smack), gfp);
99
if (tsp == NULL)
100
return NULL;
101
102
tsp->smk_task = task;
103
tsp->smk_forked = forked;
104
INIT_LIST_HEAD(&tsp->smk_rules);
105
mutex_init(&tsp->smk_rules_lock);
106
107
return tsp;
108
}
109
110
/**
111
* smk_copy_rules - copy a rule set
112
* @nhead - new rules header pointer
113
* @ohead - old rules header pointer
114
*
115
* Returns 0 on success, -ENOMEM on error
116
*/
117
static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
118
gfp_t gfp)
119
{
120
struct smack_rule *nrp;
121
struct smack_rule *orp;
122
int rc = 0;
123
124
INIT_LIST_HEAD(nhead);
125
126
list_for_each_entry_rcu(orp, ohead, list) {
127
nrp = kzalloc(sizeof(struct smack_rule), gfp);
128
if (nrp == NULL) {
129
rc = -ENOMEM;
130
break;
131
}
132
*nrp = *orp;
133
list_add_rcu(&nrp->list, nhead);
134
}
135
return rc;
136
}
137
138
/*
139
* LSM hooks.
140
* We he, that is fun!
141
*/
142
143
/**
144
* smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
145
* @ctp: child task pointer
146
* @mode: ptrace attachment mode
147
*
148
* Returns 0 if access is OK, an error code otherwise
149
*
150
* Do the capability checks, and require read and write.
151
*/
152
static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
153
{
154
int rc;
155
struct smk_audit_info ad;
156
char *tsp;
157
158
rc = cap_ptrace_access_check(ctp, mode);
159
if (rc != 0)
160
return rc;
161
162
tsp = smk_of_task(task_security(ctp));
163
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
164
smk_ad_setfield_u_tsk(&ad, ctp);
165
166
rc = smk_curacc(tsp, MAY_READWRITE, &ad);
167
return rc;
168
}
169
170
/**
171
* smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
172
* @ptp: parent task pointer
173
*
174
* Returns 0 if access is OK, an error code otherwise
175
*
176
* Do the capability checks, and require read and write.
177
*/
178
static int smack_ptrace_traceme(struct task_struct *ptp)
179
{
180
int rc;
181
struct smk_audit_info ad;
182
char *tsp;
183
184
rc = cap_ptrace_traceme(ptp);
185
if (rc != 0)
186
return rc;
187
188
tsp = smk_of_task(task_security(ptp));
189
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
190
smk_ad_setfield_u_tsk(&ad, ptp);
191
192
rc = smk_curacc(tsp, MAY_READWRITE, &ad);
193
return rc;
194
}
195
196
/**
197
* smack_syslog - Smack approval on syslog
198
* @type: message type
199
*
200
* Require that the task has the floor label
201
*
202
* Returns 0 on success, error code otherwise.
203
*/
204
static int smack_syslog(int typefrom_file)
205
{
206
int rc = 0;
207
char *sp = smk_of_current();
208
209
if (capable(CAP_MAC_OVERRIDE))
210
return 0;
211
212
if (sp != smack_known_floor.smk_known)
213
rc = -EACCES;
214
215
return rc;
216
}
217
218
219
/*
220
* Superblock Hooks.
221
*/
222
223
/**
224
* smack_sb_alloc_security - allocate a superblock blob
225
* @sb: the superblock getting the blob
226
*
227
* Returns 0 on success or -ENOMEM on error.
228
*/
229
static int smack_sb_alloc_security(struct super_block *sb)
230
{
231
struct superblock_smack *sbsp;
232
233
sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
234
235
if (sbsp == NULL)
236
return -ENOMEM;
237
238
sbsp->smk_root = smack_known_floor.smk_known;
239
sbsp->smk_default = smack_known_floor.smk_known;
240
sbsp->smk_floor = smack_known_floor.smk_known;
241
sbsp->smk_hat = smack_known_hat.smk_known;
242
sbsp->smk_initialized = 0;
243
spin_lock_init(&sbsp->smk_sblock);
244
245
sb->s_security = sbsp;
246
247
return 0;
248
}
249
250
/**
251
* smack_sb_free_security - free a superblock blob
252
* @sb: the superblock getting the blob
253
*
254
*/
255
static void smack_sb_free_security(struct super_block *sb)
256
{
257
kfree(sb->s_security);
258
sb->s_security = NULL;
259
}
260
261
/**
262
* smack_sb_copy_data - copy mount options data for processing
263
* @orig: where to start
264
* @smackopts: mount options string
265
*
266
* Returns 0 on success or -ENOMEM on error.
267
*
268
* Copy the Smack specific mount options out of the mount
269
* options list.
270
*/
271
static int smack_sb_copy_data(char *orig, char *smackopts)
272
{
273
char *cp, *commap, *otheropts, *dp;
274
275
otheropts = (char *)get_zeroed_page(GFP_KERNEL);
276
if (otheropts == NULL)
277
return -ENOMEM;
278
279
for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
280
if (strstr(cp, SMK_FSDEFAULT) == cp)
281
dp = smackopts;
282
else if (strstr(cp, SMK_FSFLOOR) == cp)
283
dp = smackopts;
284
else if (strstr(cp, SMK_FSHAT) == cp)
285
dp = smackopts;
286
else if (strstr(cp, SMK_FSROOT) == cp)
287
dp = smackopts;
288
else
289
dp = otheropts;
290
291
commap = strchr(cp, ',');
292
if (commap != NULL)
293
*commap = '\0';
294
295
if (*dp != '\0')
296
strcat(dp, ",");
297
strcat(dp, cp);
298
}
299
300
strcpy(orig, otheropts);
301
free_page((unsigned long)otheropts);
302
303
return 0;
304
}
305
306
/**
307
* smack_sb_kern_mount - Smack specific mount processing
308
* @sb: the file system superblock
309
* @flags: the mount flags
310
* @data: the smack mount options
311
*
312
* Returns 0 on success, an error code on failure
313
*/
314
static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
315
{
316
struct dentry *root = sb->s_root;
317
struct inode *inode = root->d_inode;
318
struct superblock_smack *sp = sb->s_security;
319
struct inode_smack *isp;
320
char *op;
321
char *commap;
322
char *nsp;
323
324
spin_lock(&sp->smk_sblock);
325
if (sp->smk_initialized != 0) {
326
spin_unlock(&sp->smk_sblock);
327
return 0;
328
}
329
sp->smk_initialized = 1;
330
spin_unlock(&sp->smk_sblock);
331
332
for (op = data; op != NULL; op = commap) {
333
commap = strchr(op, ',');
334
if (commap != NULL)
335
*commap++ = '\0';
336
337
if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
338
op += strlen(SMK_FSHAT);
339
nsp = smk_import(op, 0);
340
if (nsp != NULL)
341
sp->smk_hat = nsp;
342
} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
343
op += strlen(SMK_FSFLOOR);
344
nsp = smk_import(op, 0);
345
if (nsp != NULL)
346
sp->smk_floor = nsp;
347
} else if (strncmp(op, SMK_FSDEFAULT,
348
strlen(SMK_FSDEFAULT)) == 0) {
349
op += strlen(SMK_FSDEFAULT);
350
nsp = smk_import(op, 0);
351
if (nsp != NULL)
352
sp->smk_default = nsp;
353
} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
354
op += strlen(SMK_FSROOT);
355
nsp = smk_import(op, 0);
356
if (nsp != NULL)
357
sp->smk_root = nsp;
358
}
359
}
360
361
/*
362
* Initialize the root inode.
363
*/
364
isp = inode->i_security;
365
if (isp == NULL)
366
inode->i_security = new_inode_smack(sp->smk_root);
367
else
368
isp->smk_inode = sp->smk_root;
369
370
return 0;
371
}
372
373
/**
374
* smack_sb_statfs - Smack check on statfs
375
* @dentry: identifies the file system in question
376
*
377
* Returns 0 if current can read the floor of the filesystem,
378
* and error code otherwise
379
*/
380
static int smack_sb_statfs(struct dentry *dentry)
381
{
382
struct superblock_smack *sbp = dentry->d_sb->s_security;
383
int rc;
384
struct smk_audit_info ad;
385
386
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
387
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
388
389
rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
390
return rc;
391
}
392
393
/**
394
* smack_sb_mount - Smack check for mounting
395
* @dev_name: unused
396
* @path: mount point
397
* @type: unused
398
* @flags: unused
399
* @data: unused
400
*
401
* Returns 0 if current can write the floor of the filesystem
402
* being mounted on, an error code otherwise.
403
*/
404
static int smack_sb_mount(char *dev_name, struct path *path,
405
char *type, unsigned long flags, void *data)
406
{
407
struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
408
struct smk_audit_info ad;
409
410
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
411
smk_ad_setfield_u_fs_path(&ad, *path);
412
413
return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
414
}
415
416
/**
417
* smack_sb_umount - Smack check for unmounting
418
* @mnt: file system to unmount
419
* @flags: unused
420
*
421
* Returns 0 if current can write the floor of the filesystem
422
* being unmounted, an error code otherwise.
423
*/
424
static int smack_sb_umount(struct vfsmount *mnt, int flags)
425
{
426
struct superblock_smack *sbp;
427
struct smk_audit_info ad;
428
struct path path;
429
430
path.dentry = mnt->mnt_root;
431
path.mnt = mnt;
432
433
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
434
smk_ad_setfield_u_fs_path(&ad, path);
435
436
sbp = mnt->mnt_sb->s_security;
437
return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
438
}
439
440
/*
441
* BPRM hooks
442
*/
443
444
static int smack_bprm_set_creds(struct linux_binprm *bprm)
445
{
446
struct task_smack *tsp = bprm->cred->security;
447
struct inode_smack *isp;
448
struct dentry *dp;
449
int rc;
450
451
rc = cap_bprm_set_creds(bprm);
452
if (rc != 0)
453
return rc;
454
455
if (bprm->cred_prepared)
456
return 0;
457
458
if (bprm->file == NULL || bprm->file->f_dentry == NULL)
459
return 0;
460
461
dp = bprm->file->f_dentry;
462
463
if (dp->d_inode == NULL)
464
return 0;
465
466
isp = dp->d_inode->i_security;
467
468
if (isp->smk_task != NULL)
469
tsp->smk_task = isp->smk_task;
470
471
return 0;
472
}
473
474
/*
475
* Inode hooks
476
*/
477
478
/**
479
* smack_inode_alloc_security - allocate an inode blob
480
* @inode: the inode in need of a blob
481
*
482
* Returns 0 if it gets a blob, -ENOMEM otherwise
483
*/
484
static int smack_inode_alloc_security(struct inode *inode)
485
{
486
inode->i_security = new_inode_smack(smk_of_current());
487
if (inode->i_security == NULL)
488
return -ENOMEM;
489
return 0;
490
}
491
492
/**
493
* smack_inode_free_security - free an inode blob
494
* @inode: the inode with a blob
495
*
496
* Clears the blob pointer in inode
497
*/
498
static void smack_inode_free_security(struct inode *inode)
499
{
500
kfree(inode->i_security);
501
inode->i_security = NULL;
502
}
503
504
/**
505
* smack_inode_init_security - copy out the smack from an inode
506
* @inode: the inode
507
* @dir: unused
508
* @qstr: unused
509
* @name: where to put the attribute name
510
* @value: where to put the attribute value
511
* @len: where to put the length of the attribute
512
*
513
* Returns 0 if it all works out, -ENOMEM if there's no memory
514
*/
515
static int smack_inode_init_security(struct inode *inode, struct inode *dir,
516
const struct qstr *qstr, char **name,
517
void **value, size_t *len)
518
{
519
char *isp = smk_of_inode(inode);
520
char *dsp = smk_of_inode(dir);
521
int may;
522
523
if (name) {
524
*name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
525
if (*name == NULL)
526
return -ENOMEM;
527
}
528
529
if (value) {
530
rcu_read_lock();
531
may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
532
rcu_read_unlock();
533
534
/*
535
* If the access rule allows transmutation and
536
* the directory requests transmutation then
537
* by all means transmute.
538
*/
539
if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
540
smk_inode_transmutable(dir))
541
isp = dsp;
542
543
*value = kstrdup(isp, GFP_KERNEL);
544
if (*value == NULL)
545
return -ENOMEM;
546
}
547
548
if (len)
549
*len = strlen(isp) + 1;
550
551
return 0;
552
}
553
554
/**
555
* smack_inode_link - Smack check on link
556
* @old_dentry: the existing object
557
* @dir: unused
558
* @new_dentry: the new object
559
*
560
* Returns 0 if access is permitted, an error code otherwise
561
*/
562
static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
563
struct dentry *new_dentry)
564
{
565
char *isp;
566
struct smk_audit_info ad;
567
int rc;
568
569
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
570
smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
571
572
isp = smk_of_inode(old_dentry->d_inode);
573
rc = smk_curacc(isp, MAY_WRITE, &ad);
574
575
if (rc == 0 && new_dentry->d_inode != NULL) {
576
isp = smk_of_inode(new_dentry->d_inode);
577
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
578
rc = smk_curacc(isp, MAY_WRITE, &ad);
579
}
580
581
return rc;
582
}
583
584
/**
585
* smack_inode_unlink - Smack check on inode deletion
586
* @dir: containing directory object
587
* @dentry: file to unlink
588
*
589
* Returns 0 if current can write the containing directory
590
* and the object, error code otherwise
591
*/
592
static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
593
{
594
struct inode *ip = dentry->d_inode;
595
struct smk_audit_info ad;
596
int rc;
597
598
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
599
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
600
601
/*
602
* You need write access to the thing you're unlinking
603
*/
604
rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
605
if (rc == 0) {
606
/*
607
* You also need write access to the containing directory
608
*/
609
smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
610
smk_ad_setfield_u_fs_inode(&ad, dir);
611
rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
612
}
613
return rc;
614
}
615
616
/**
617
* smack_inode_rmdir - Smack check on directory deletion
618
* @dir: containing directory object
619
* @dentry: directory to unlink
620
*
621
* Returns 0 if current can write the containing directory
622
* and the directory, error code otherwise
623
*/
624
static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
625
{
626
struct smk_audit_info ad;
627
int rc;
628
629
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
630
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
631
632
/*
633
* You need write access to the thing you're removing
634
*/
635
rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
636
if (rc == 0) {
637
/*
638
* You also need write access to the containing directory
639
*/
640
smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
641
smk_ad_setfield_u_fs_inode(&ad, dir);
642
rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
643
}
644
645
return rc;
646
}
647
648
/**
649
* smack_inode_rename - Smack check on rename
650
* @old_inode: the old directory
651
* @old_dentry: unused
652
* @new_inode: the new directory
653
* @new_dentry: unused
654
*
655
* Read and write access is required on both the old and
656
* new directories.
657
*
658
* Returns 0 if access is permitted, an error code otherwise
659
*/
660
static int smack_inode_rename(struct inode *old_inode,
661
struct dentry *old_dentry,
662
struct inode *new_inode,
663
struct dentry *new_dentry)
664
{
665
int rc;
666
char *isp;
667
struct smk_audit_info ad;
668
669
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
670
smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
671
672
isp = smk_of_inode(old_dentry->d_inode);
673
rc = smk_curacc(isp, MAY_READWRITE, &ad);
674
675
if (rc == 0 && new_dentry->d_inode != NULL) {
676
isp = smk_of_inode(new_dentry->d_inode);
677
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
678
rc = smk_curacc(isp, MAY_READWRITE, &ad);
679
}
680
return rc;
681
}
682
683
/**
684
* smack_inode_permission - Smack version of permission()
685
* @inode: the inode in question
686
* @mask: the access requested
687
*
688
* This is the important Smack hook.
689
*
690
* Returns 0 if access is permitted, -EACCES otherwise
691
*/
692
static int smack_inode_permission(struct inode *inode, int mask, unsigned flags)
693
{
694
struct smk_audit_info ad;
695
696
mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
697
/*
698
* No permission to check. Existence test. Yup, it's there.
699
*/
700
if (mask == 0)
701
return 0;
702
703
/* May be droppable after audit */
704
if (flags & IPERM_FLAG_RCU)
705
return -ECHILD;
706
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
707
smk_ad_setfield_u_fs_inode(&ad, inode);
708
return smk_curacc(smk_of_inode(inode), mask, &ad);
709
}
710
711
/**
712
* smack_inode_setattr - Smack check for setting attributes
713
* @dentry: the object
714
* @iattr: for the force flag
715
*
716
* Returns 0 if access is permitted, an error code otherwise
717
*/
718
static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
719
{
720
struct smk_audit_info ad;
721
/*
722
* Need to allow for clearing the setuid bit.
723
*/
724
if (iattr->ia_valid & ATTR_FORCE)
725
return 0;
726
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
727
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
728
729
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
730
}
731
732
/**
733
* smack_inode_getattr - Smack check for getting attributes
734
* @mnt: unused
735
* @dentry: the object
736
*
737
* Returns 0 if access is permitted, an error code otherwise
738
*/
739
static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
740
{
741
struct smk_audit_info ad;
742
struct path path;
743
744
path.dentry = dentry;
745
path.mnt = mnt;
746
747
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
748
smk_ad_setfield_u_fs_path(&ad, path);
749
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
750
}
751
752
/**
753
* smack_inode_setxattr - Smack check for setting xattrs
754
* @dentry: the object
755
* @name: name of the attribute
756
* @value: unused
757
* @size: unused
758
* @flags: unused
759
*
760
* This protects the Smack attribute explicitly.
761
*
762
* Returns 0 if access is permitted, an error code otherwise
763
*/
764
static int smack_inode_setxattr(struct dentry *dentry, const char *name,
765
const void *value, size_t size, int flags)
766
{
767
struct smk_audit_info ad;
768
int rc = 0;
769
770
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
771
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
772
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
773
strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
774
strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
775
if (!capable(CAP_MAC_ADMIN))
776
rc = -EPERM;
777
/*
778
* check label validity here so import wont fail on
779
* post_setxattr
780
*/
781
if (size == 0 || size >= SMK_LABELLEN ||
782
smk_import(value, size) == NULL)
783
rc = -EINVAL;
784
} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
785
if (!capable(CAP_MAC_ADMIN))
786
rc = -EPERM;
787
if (size != TRANS_TRUE_SIZE ||
788
strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
789
rc = -EINVAL;
790
} else
791
rc = cap_inode_setxattr(dentry, name, value, size, flags);
792
793
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
794
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
795
796
if (rc == 0)
797
rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
798
799
return rc;
800
}
801
802
/**
803
* smack_inode_post_setxattr - Apply the Smack update approved above
804
* @dentry: object
805
* @name: attribute name
806
* @value: attribute value
807
* @size: attribute size
808
* @flags: unused
809
*
810
* Set the pointer in the inode blob to the entry found
811
* in the master label list.
812
*/
813
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
814
const void *value, size_t size, int flags)
815
{
816
char *nsp;
817
struct inode_smack *isp = dentry->d_inode->i_security;
818
819
if (strcmp(name, XATTR_NAME_SMACK) == 0) {
820
nsp = smk_import(value, size);
821
if (nsp != NULL)
822
isp->smk_inode = nsp;
823
else
824
isp->smk_inode = smack_known_invalid.smk_known;
825
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
826
nsp = smk_import(value, size);
827
if (nsp != NULL)
828
isp->smk_task = nsp;
829
else
830
isp->smk_task = smack_known_invalid.smk_known;
831
} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
832
nsp = smk_import(value, size);
833
if (nsp != NULL)
834
isp->smk_mmap = nsp;
835
else
836
isp->smk_mmap = smack_known_invalid.smk_known;
837
} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
838
isp->smk_flags |= SMK_INODE_TRANSMUTE;
839
840
return;
841
}
842
843
/*
844
* smack_inode_getxattr - Smack check on getxattr
845
* @dentry: the object
846
* @name: unused
847
*
848
* Returns 0 if access is permitted, an error code otherwise
849
*/
850
static int smack_inode_getxattr(struct dentry *dentry, const char *name)
851
{
852
struct smk_audit_info ad;
853
854
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
855
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
856
857
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
858
}
859
860
/*
861
* smack_inode_removexattr - Smack check on removexattr
862
* @dentry: the object
863
* @name: name of the attribute
864
*
865
* Removing the Smack attribute requires CAP_MAC_ADMIN
866
*
867
* Returns 0 if access is permitted, an error code otherwise
868
*/
869
static int smack_inode_removexattr(struct dentry *dentry, const char *name)
870
{
871
struct inode_smack *isp;
872
struct smk_audit_info ad;
873
int rc = 0;
874
875
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
876
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
877
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
878
strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
879
strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
880
strcmp(name, XATTR_NAME_SMACKMMAP)) {
881
if (!capable(CAP_MAC_ADMIN))
882
rc = -EPERM;
883
} else
884
rc = cap_inode_removexattr(dentry, name);
885
886
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
887
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
888
if (rc == 0)
889
rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
890
891
if (rc == 0) {
892
isp = dentry->d_inode->i_security;
893
isp->smk_task = NULL;
894
isp->smk_mmap = NULL;
895
}
896
897
return rc;
898
}
899
900
/**
901
* smack_inode_getsecurity - get smack xattrs
902
* @inode: the object
903
* @name: attribute name
904
* @buffer: where to put the result
905
* @alloc: unused
906
*
907
* Returns the size of the attribute or an error code
908
*/
909
static int smack_inode_getsecurity(const struct inode *inode,
910
const char *name, void **buffer,
911
bool alloc)
912
{
913
struct socket_smack *ssp;
914
struct socket *sock;
915
struct super_block *sbp;
916
struct inode *ip = (struct inode *)inode;
917
char *isp;
918
int ilen;
919
int rc = 0;
920
921
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
922
isp = smk_of_inode(inode);
923
ilen = strlen(isp) + 1;
924
*buffer = isp;
925
return ilen;
926
}
927
928
/*
929
* The rest of the Smack xattrs are only on sockets.
930
*/
931
sbp = ip->i_sb;
932
if (sbp->s_magic != SOCKFS_MAGIC)
933
return -EOPNOTSUPP;
934
935
sock = SOCKET_I(ip);
936
if (sock == NULL || sock->sk == NULL)
937
return -EOPNOTSUPP;
938
939
ssp = sock->sk->sk_security;
940
941
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
942
isp = ssp->smk_in;
943
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
944
isp = ssp->smk_out;
945
else
946
return -EOPNOTSUPP;
947
948
ilen = strlen(isp) + 1;
949
if (rc == 0) {
950
*buffer = isp;
951
rc = ilen;
952
}
953
954
return rc;
955
}
956
957
958
/**
959
* smack_inode_listsecurity - list the Smack attributes
960
* @inode: the object
961
* @buffer: where they go
962
* @buffer_size: size of buffer
963
*
964
* Returns 0 on success, -EINVAL otherwise
965
*/
966
static int smack_inode_listsecurity(struct inode *inode, char *buffer,
967
size_t buffer_size)
968
{
969
int len = strlen(XATTR_NAME_SMACK);
970
971
if (buffer != NULL && len <= buffer_size) {
972
memcpy(buffer, XATTR_NAME_SMACK, len);
973
return len;
974
}
975
return -EINVAL;
976
}
977
978
/**
979
* smack_inode_getsecid - Extract inode's security id
980
* @inode: inode to extract the info from
981
* @secid: where result will be saved
982
*/
983
static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
984
{
985
struct inode_smack *isp = inode->i_security;
986
987
*secid = smack_to_secid(isp->smk_inode);
988
}
989
990
/*
991
* File Hooks
992
*/
993
994
/**
995
* smack_file_permission - Smack check on file operations
996
* @file: unused
997
* @mask: unused
998
*
999
* Returns 0
1000
*
1001
* Should access checks be done on each read or write?
1002
* UNICOS and SELinux say yes.
1003
* Trusted Solaris, Trusted Irix, and just about everyone else says no.
1004
*
1005
* I'll say no for now. Smack does not do the frequent
1006
* label changing that SELinux does.
1007
*/
1008
static int smack_file_permission(struct file *file, int mask)
1009
{
1010
return 0;
1011
}
1012
1013
/**
1014
* smack_file_alloc_security - assign a file security blob
1015
* @file: the object
1016
*
1017
* The security blob for a file is a pointer to the master
1018
* label list, so no allocation is done.
1019
*
1020
* Returns 0
1021
*/
1022
static int smack_file_alloc_security(struct file *file)
1023
{
1024
file->f_security = smk_of_current();
1025
return 0;
1026
}
1027
1028
/**
1029
* smack_file_free_security - clear a file security blob
1030
* @file: the object
1031
*
1032
* The security blob for a file is a pointer to the master
1033
* label list, so no memory is freed.
1034
*/
1035
static void smack_file_free_security(struct file *file)
1036
{
1037
file->f_security = NULL;
1038
}
1039
1040
/**
1041
* smack_file_ioctl - Smack check on ioctls
1042
* @file: the object
1043
* @cmd: what to do
1044
* @arg: unused
1045
*
1046
* Relies heavily on the correct use of the ioctl command conventions.
1047
*
1048
* Returns 0 if allowed, error code otherwise
1049
*/
1050
static int smack_file_ioctl(struct file *file, unsigned int cmd,
1051
unsigned long arg)
1052
{
1053
int rc = 0;
1054
struct smk_audit_info ad;
1055
1056
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1057
smk_ad_setfield_u_fs_path(&ad, file->f_path);
1058
1059
if (_IOC_DIR(cmd) & _IOC_WRITE)
1060
rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1061
1062
if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1063
rc = smk_curacc(file->f_security, MAY_READ, &ad);
1064
1065
return rc;
1066
}
1067
1068
/**
1069
* smack_file_lock - Smack check on file locking
1070
* @file: the object
1071
* @cmd: unused
1072
*
1073
* Returns 0 if current has write access, error code otherwise
1074
*/
1075
static int smack_file_lock(struct file *file, unsigned int cmd)
1076
{
1077
struct smk_audit_info ad;
1078
1079
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1080
smk_ad_setfield_u_fs_path(&ad, file->f_path);
1081
return smk_curacc(file->f_security, MAY_WRITE, &ad);
1082
}
1083
1084
/**
1085
* smack_file_fcntl - Smack check on fcntl
1086
* @file: the object
1087
* @cmd: what action to check
1088
* @arg: unused
1089
*
1090
* Returns 0 if current has access, error code otherwise
1091
*/
1092
static int smack_file_fcntl(struct file *file, unsigned int cmd,
1093
unsigned long arg)
1094
{
1095
struct smk_audit_info ad;
1096
int rc;
1097
1098
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1099
smk_ad_setfield_u_fs_path(&ad, file->f_path);
1100
1101
switch (cmd) {
1102
case F_DUPFD:
1103
case F_GETFD:
1104
case F_GETFL:
1105
case F_GETLK:
1106
case F_GETOWN:
1107
case F_GETSIG:
1108
rc = smk_curacc(file->f_security, MAY_READ, &ad);
1109
break;
1110
case F_SETFD:
1111
case F_SETFL:
1112
case F_SETLK:
1113
case F_SETLKW:
1114
case F_SETOWN:
1115
case F_SETSIG:
1116
rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1117
break;
1118
default:
1119
rc = smk_curacc(file->f_security, MAY_READWRITE, &ad);
1120
}
1121
1122
return rc;
1123
}
1124
1125
/**
1126
* smack_file_mmap :
1127
* Check permissions for a mmap operation. The @file may be NULL, e.g.
1128
* if mapping anonymous memory.
1129
* @file contains the file structure for file to map (may be NULL).
1130
* @reqprot contains the protection requested by the application.
1131
* @prot contains the protection that will be applied by the kernel.
1132
* @flags contains the operational flags.
1133
* Return 0 if permission is granted.
1134
*/
1135
static int smack_file_mmap(struct file *file,
1136
unsigned long reqprot, unsigned long prot,
1137
unsigned long flags, unsigned long addr,
1138
unsigned long addr_only)
1139
{
1140
struct smack_rule *srp;
1141
struct task_smack *tsp;
1142
char *sp;
1143
char *msmack;
1144
char *osmack;
1145
struct inode_smack *isp;
1146
struct dentry *dp;
1147
int may;
1148
int mmay;
1149
int tmay;
1150
int rc;
1151
1152
/* do DAC check on address space usage */
1153
rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
1154
if (rc || addr_only)
1155
return rc;
1156
1157
if (file == NULL || file->f_dentry == NULL)
1158
return 0;
1159
1160
dp = file->f_dentry;
1161
1162
if (dp->d_inode == NULL)
1163
return 0;
1164
1165
isp = dp->d_inode->i_security;
1166
if (isp->smk_mmap == NULL)
1167
return 0;
1168
msmack = isp->smk_mmap;
1169
1170
tsp = current_security();
1171
sp = smk_of_current();
1172
rc = 0;
1173
1174
rcu_read_lock();
1175
/*
1176
* For each Smack rule associated with the subject
1177
* label verify that the SMACK64MMAP also has access
1178
* to that rule's object label.
1179
*
1180
* Because neither of the labels comes
1181
* from the networking code it is sufficient
1182
* to compare pointers.
1183
*/
1184
list_for_each_entry_rcu(srp, &smack_rule_list, list) {
1185
if (srp->smk_subject != sp)
1186
continue;
1187
1188
osmack = srp->smk_object;
1189
/*
1190
* Matching labels always allows access.
1191
*/
1192
if (msmack == osmack)
1193
continue;
1194
/*
1195
* If there is a matching local rule take
1196
* that into account as well.
1197
*/
1198
may = smk_access_entry(srp->smk_subject, osmack,
1199
&tsp->smk_rules);
1200
if (may == -ENOENT)
1201
may = srp->smk_access;
1202
else
1203
may &= srp->smk_access;
1204
/*
1205
* If may is zero the SMACK64MMAP subject can't
1206
* possibly have less access.
1207
*/
1208
if (may == 0)
1209
continue;
1210
1211
/*
1212
* Fetch the global list entry.
1213
* If there isn't one a SMACK64MMAP subject
1214
* can't have as much access as current.
1215
*/
1216
mmay = smk_access_entry(msmack, osmack, &smack_rule_list);
1217
if (mmay == -ENOENT) {
1218
rc = -EACCES;
1219
break;
1220
}
1221
/*
1222
* If there is a local entry it modifies the
1223
* potential access, too.
1224
*/
1225
tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules);
1226
if (tmay != -ENOENT)
1227
mmay &= tmay;
1228
1229
/*
1230
* If there is any access available to current that is
1231
* not available to a SMACK64MMAP subject
1232
* deny access.
1233
*/
1234
if ((may | mmay) != mmay) {
1235
rc = -EACCES;
1236
break;
1237
}
1238
}
1239
1240
rcu_read_unlock();
1241
1242
return rc;
1243
}
1244
1245
/**
1246
* smack_file_set_fowner - set the file security blob value
1247
* @file: object in question
1248
*
1249
* Returns 0
1250
* Further research may be required on this one.
1251
*/
1252
static int smack_file_set_fowner(struct file *file)
1253
{
1254
file->f_security = smk_of_current();
1255
return 0;
1256
}
1257
1258
/**
1259
* smack_file_send_sigiotask - Smack on sigio
1260
* @tsk: The target task
1261
* @fown: the object the signal come from
1262
* @signum: unused
1263
*
1264
* Allow a privileged task to get signals even if it shouldn't
1265
*
1266
* Returns 0 if a subject with the object's smack could
1267
* write to the task, an error code otherwise.
1268
*/
1269
static int smack_file_send_sigiotask(struct task_struct *tsk,
1270
struct fown_struct *fown, int signum)
1271
{
1272
struct file *file;
1273
int rc;
1274
char *tsp = smk_of_task(tsk->cred->security);
1275
struct smk_audit_info ad;
1276
1277
/*
1278
* struct fown_struct is never outside the context of a struct file
1279
*/
1280
file = container_of(fown, struct file, f_owner);
1281
1282
/* we don't log here as rc can be overriden */
1283
rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1284
if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1285
rc = 0;
1286
1287
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1288
smk_ad_setfield_u_tsk(&ad, tsk);
1289
smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1290
return rc;
1291
}
1292
1293
/**
1294
* smack_file_receive - Smack file receive check
1295
* @file: the object
1296
*
1297
* Returns 0 if current has access, error code otherwise
1298
*/
1299
static int smack_file_receive(struct file *file)
1300
{
1301
int may = 0;
1302
struct smk_audit_info ad;
1303
1304
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1305
smk_ad_setfield_u_fs_path(&ad, file->f_path);
1306
/*
1307
* This code relies on bitmasks.
1308
*/
1309
if (file->f_mode & FMODE_READ)
1310
may = MAY_READ;
1311
if (file->f_mode & FMODE_WRITE)
1312
may |= MAY_WRITE;
1313
1314
return smk_curacc(file->f_security, may, &ad);
1315
}
1316
1317
/*
1318
* Task hooks
1319
*/
1320
1321
/**
1322
* smack_cred_alloc_blank - "allocate" blank task-level security credentials
1323
* @new: the new credentials
1324
* @gfp: the atomicity of any memory allocations
1325
*
1326
* Prepare a blank set of credentials for modification. This must allocate all
1327
* the memory the LSM module might require such that cred_transfer() can
1328
* complete without error.
1329
*/
1330
static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1331
{
1332
struct task_smack *tsp;
1333
1334
tsp = new_task_smack(NULL, NULL, gfp);
1335
if (tsp == NULL)
1336
return -ENOMEM;
1337
1338
cred->security = tsp;
1339
1340
return 0;
1341
}
1342
1343
1344
/**
1345
* smack_cred_free - "free" task-level security credentials
1346
* @cred: the credentials in question
1347
*
1348
*/
1349
static void smack_cred_free(struct cred *cred)
1350
{
1351
struct task_smack *tsp = cred->security;
1352
struct smack_rule *rp;
1353
struct list_head *l;
1354
struct list_head *n;
1355
1356
if (tsp == NULL)
1357
return;
1358
cred->security = NULL;
1359
1360
list_for_each_safe(l, n, &tsp->smk_rules) {
1361
rp = list_entry(l, struct smack_rule, list);
1362
list_del(&rp->list);
1363
kfree(rp);
1364
}
1365
kfree(tsp);
1366
}
1367
1368
/**
1369
* smack_cred_prepare - prepare new set of credentials for modification
1370
* @new: the new credentials
1371
* @old: the original credentials
1372
* @gfp: the atomicity of any memory allocations
1373
*
1374
* Prepare a new set of credentials for modification.
1375
*/
1376
static int smack_cred_prepare(struct cred *new, const struct cred *old,
1377
gfp_t gfp)
1378
{
1379
struct task_smack *old_tsp = old->security;
1380
struct task_smack *new_tsp;
1381
int rc;
1382
1383
new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1384
if (new_tsp == NULL)
1385
return -ENOMEM;
1386
1387
rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1388
if (rc != 0)
1389
return rc;
1390
1391
new->security = new_tsp;
1392
return 0;
1393
}
1394
1395
/**
1396
* smack_cred_transfer - Transfer the old credentials to the new credentials
1397
* @new: the new credentials
1398
* @old: the original credentials
1399
*
1400
* Fill in a set of blank credentials from another set of credentials.
1401
*/
1402
static void smack_cred_transfer(struct cred *new, const struct cred *old)
1403
{
1404
struct task_smack *old_tsp = old->security;
1405
struct task_smack *new_tsp = new->security;
1406
1407
new_tsp->smk_task = old_tsp->smk_task;
1408
new_tsp->smk_forked = old_tsp->smk_task;
1409
mutex_init(&new_tsp->smk_rules_lock);
1410
INIT_LIST_HEAD(&new_tsp->smk_rules);
1411
1412
1413
/* cbs copy rule list */
1414
}
1415
1416
/**
1417
* smack_kernel_act_as - Set the subjective context in a set of credentials
1418
* @new: points to the set of credentials to be modified.
1419
* @secid: specifies the security ID to be set
1420
*
1421
* Set the security data for a kernel service.
1422
*/
1423
static int smack_kernel_act_as(struct cred *new, u32 secid)
1424
{
1425
struct task_smack *new_tsp = new->security;
1426
char *smack = smack_from_secid(secid);
1427
1428
if (smack == NULL)
1429
return -EINVAL;
1430
1431
new_tsp->smk_task = smack;
1432
return 0;
1433
}
1434
1435
/**
1436
* smack_kernel_create_files_as - Set the file creation label in a set of creds
1437
* @new: points to the set of credentials to be modified
1438
* @inode: points to the inode to use as a reference
1439
*
1440
* Set the file creation context in a set of credentials to the same
1441
* as the objective context of the specified inode
1442
*/
1443
static int smack_kernel_create_files_as(struct cred *new,
1444
struct inode *inode)
1445
{
1446
struct inode_smack *isp = inode->i_security;
1447
struct task_smack *tsp = new->security;
1448
1449
tsp->smk_forked = isp->smk_inode;
1450
tsp->smk_task = isp->smk_inode;
1451
return 0;
1452
}
1453
1454
/**
1455
* smk_curacc_on_task - helper to log task related access
1456
* @p: the task object
1457
* @access : the access requested
1458
*
1459
* Return 0 if access is permitted
1460
*/
1461
static int smk_curacc_on_task(struct task_struct *p, int access)
1462
{
1463
struct smk_audit_info ad;
1464
1465
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1466
smk_ad_setfield_u_tsk(&ad, p);
1467
return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1468
}
1469
1470
/**
1471
* smack_task_setpgid - Smack check on setting pgid
1472
* @p: the task object
1473
* @pgid: unused
1474
*
1475
* Return 0 if write access is permitted
1476
*/
1477
static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1478
{
1479
return smk_curacc_on_task(p, MAY_WRITE);
1480
}
1481
1482
/**
1483
* smack_task_getpgid - Smack access check for getpgid
1484
* @p: the object task
1485
*
1486
* Returns 0 if current can read the object task, error code otherwise
1487
*/
1488
static int smack_task_getpgid(struct task_struct *p)
1489
{
1490
return smk_curacc_on_task(p, MAY_READ);
1491
}
1492
1493
/**
1494
* smack_task_getsid - Smack access check for getsid
1495
* @p: the object task
1496
*
1497
* Returns 0 if current can read the object task, error code otherwise
1498
*/
1499
static int smack_task_getsid(struct task_struct *p)
1500
{
1501
return smk_curacc_on_task(p, MAY_READ);
1502
}
1503
1504
/**
1505
* smack_task_getsecid - get the secid of the task
1506
* @p: the object task
1507
* @secid: where to put the result
1508
*
1509
* Sets the secid to contain a u32 version of the smack label.
1510
*/
1511
static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1512
{
1513
*secid = smack_to_secid(smk_of_task(task_security(p)));
1514
}
1515
1516
/**
1517
* smack_task_setnice - Smack check on setting nice
1518
* @p: the task object
1519
* @nice: unused
1520
*
1521
* Return 0 if write access is permitted
1522
*/
1523
static int smack_task_setnice(struct task_struct *p, int nice)
1524
{
1525
int rc;
1526
1527
rc = cap_task_setnice(p, nice);
1528
if (rc == 0)
1529
rc = smk_curacc_on_task(p, MAY_WRITE);
1530
return rc;
1531
}
1532
1533
/**
1534
* smack_task_setioprio - Smack check on setting ioprio
1535
* @p: the task object
1536
* @ioprio: unused
1537
*
1538
* Return 0 if write access is permitted
1539
*/
1540
static int smack_task_setioprio(struct task_struct *p, int ioprio)
1541
{
1542
int rc;
1543
1544
rc = cap_task_setioprio(p, ioprio);
1545
if (rc == 0)
1546
rc = smk_curacc_on_task(p, MAY_WRITE);
1547
return rc;
1548
}
1549
1550
/**
1551
* smack_task_getioprio - Smack check on reading ioprio
1552
* @p: the task object
1553
*
1554
* Return 0 if read access is permitted
1555
*/
1556
static int smack_task_getioprio(struct task_struct *p)
1557
{
1558
return smk_curacc_on_task(p, MAY_READ);
1559
}
1560
1561
/**
1562
* smack_task_setscheduler - Smack check on setting scheduler
1563
* @p: the task object
1564
* @policy: unused
1565
* @lp: unused
1566
*
1567
* Return 0 if read access is permitted
1568
*/
1569
static int smack_task_setscheduler(struct task_struct *p)
1570
{
1571
int rc;
1572
1573
rc = cap_task_setscheduler(p);
1574
if (rc == 0)
1575
rc = smk_curacc_on_task(p, MAY_WRITE);
1576
return rc;
1577
}
1578
1579
/**
1580
* smack_task_getscheduler - Smack check on reading scheduler
1581
* @p: the task object
1582
*
1583
* Return 0 if read access is permitted
1584
*/
1585
static int smack_task_getscheduler(struct task_struct *p)
1586
{
1587
return smk_curacc_on_task(p, MAY_READ);
1588
}
1589
1590
/**
1591
* smack_task_movememory - Smack check on moving memory
1592
* @p: the task object
1593
*
1594
* Return 0 if write access is permitted
1595
*/
1596
static int smack_task_movememory(struct task_struct *p)
1597
{
1598
return smk_curacc_on_task(p, MAY_WRITE);
1599
}
1600
1601
/**
1602
* smack_task_kill - Smack check on signal delivery
1603
* @p: the task object
1604
* @info: unused
1605
* @sig: unused
1606
* @secid: identifies the smack to use in lieu of current's
1607
*
1608
* Return 0 if write access is permitted
1609
*
1610
* The secid behavior is an artifact of an SELinux hack
1611
* in the USB code. Someday it may go away.
1612
*/
1613
static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1614
int sig, u32 secid)
1615
{
1616
struct smk_audit_info ad;
1617
1618
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1619
smk_ad_setfield_u_tsk(&ad, p);
1620
/*
1621
* Sending a signal requires that the sender
1622
* can write the receiver.
1623
*/
1624
if (secid == 0)
1625
return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1626
&ad);
1627
/*
1628
* If the secid isn't 0 we're dealing with some USB IO
1629
* specific behavior. This is not clean. For one thing
1630
* we can't take privilege into account.
1631
*/
1632
return smk_access(smack_from_secid(secid),
1633
smk_of_task(task_security(p)), MAY_WRITE, &ad);
1634
}
1635
1636
/**
1637
* smack_task_wait - Smack access check for waiting
1638
* @p: task to wait for
1639
*
1640
* Returns 0 if current can wait for p, error code otherwise
1641
*/
1642
static int smack_task_wait(struct task_struct *p)
1643
{
1644
struct smk_audit_info ad;
1645
char *sp = smk_of_current();
1646
char *tsp = smk_of_forked(task_security(p));
1647
int rc;
1648
1649
/* we don't log here, we can be overriden */
1650
rc = smk_access(tsp, sp, MAY_WRITE, NULL);
1651
if (rc == 0)
1652
goto out_log;
1653
1654
/*
1655
* Allow the operation to succeed if either task
1656
* has privilege to perform operations that might
1657
* account for the smack labels having gotten to
1658
* be different in the first place.
1659
*
1660
* This breaks the strict subject/object access
1661
* control ideal, taking the object's privilege
1662
* state into account in the decision as well as
1663
* the smack value.
1664
*/
1665
if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1666
rc = 0;
1667
/* we log only if we didn't get overriden */
1668
out_log:
1669
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1670
smk_ad_setfield_u_tsk(&ad, p);
1671
smack_log(tsp, sp, MAY_WRITE, rc, &ad);
1672
return rc;
1673
}
1674
1675
/**
1676
* smack_task_to_inode - copy task smack into the inode blob
1677
* @p: task to copy from
1678
* @inode: inode to copy to
1679
*
1680
* Sets the smack pointer in the inode security blob
1681
*/
1682
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1683
{
1684
struct inode_smack *isp = inode->i_security;
1685
isp->smk_inode = smk_of_task(task_security(p));
1686
}
1687
1688
/*
1689
* Socket hooks.
1690
*/
1691
1692
/**
1693
* smack_sk_alloc_security - Allocate a socket blob
1694
* @sk: the socket
1695
* @family: unused
1696
* @gfp_flags: memory allocation flags
1697
*
1698
* Assign Smack pointers to current
1699
*
1700
* Returns 0 on success, -ENOMEM is there's no memory
1701
*/
1702
static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1703
{
1704
char *csp = smk_of_current();
1705
struct socket_smack *ssp;
1706
1707
ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1708
if (ssp == NULL)
1709
return -ENOMEM;
1710
1711
ssp->smk_in = csp;
1712
ssp->smk_out = csp;
1713
ssp->smk_packet[0] = '\0';
1714
1715
sk->sk_security = ssp;
1716
1717
return 0;
1718
}
1719
1720
/**
1721
* smack_sk_free_security - Free a socket blob
1722
* @sk: the socket
1723
*
1724
* Clears the blob pointer
1725
*/
1726
static void smack_sk_free_security(struct sock *sk)
1727
{
1728
kfree(sk->sk_security);
1729
}
1730
1731
/**
1732
* smack_host_label - check host based restrictions
1733
* @sip: the object end
1734
*
1735
* looks for host based access restrictions
1736
*
1737
* This version will only be appropriate for really small sets of single label
1738
* hosts. The caller is responsible for ensuring that the RCU read lock is
1739
* taken before calling this function.
1740
*
1741
* Returns the label of the far end or NULL if it's not special.
1742
*/
1743
static char *smack_host_label(struct sockaddr_in *sip)
1744
{
1745
struct smk_netlbladdr *snp;
1746
struct in_addr *siap = &sip->sin_addr;
1747
1748
if (siap->s_addr == 0)
1749
return NULL;
1750
1751
list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1752
/*
1753
* we break after finding the first match because
1754
* the list is sorted from longest to shortest mask
1755
* so we have found the most specific match
1756
*/
1757
if ((&snp->smk_host.sin_addr)->s_addr ==
1758
(siap->s_addr & (&snp->smk_mask)->s_addr)) {
1759
/* we have found the special CIPSO option */
1760
if (snp->smk_label == smack_cipso_option)
1761
return NULL;
1762
return snp->smk_label;
1763
}
1764
1765
return NULL;
1766
}
1767
1768
/**
1769
* smack_set_catset - convert a capset to netlabel mls categories
1770
* @catset: the Smack categories
1771
* @sap: where to put the netlabel categories
1772
*
1773
* Allocates and fills attr.mls.cat
1774
*/
1775
static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1776
{
1777
unsigned char *cp;
1778
unsigned char m;
1779
int cat;
1780
int rc;
1781
int byte;
1782
1783
if (!catset)
1784
return;
1785
1786
sap->flags |= NETLBL_SECATTR_MLS_CAT;
1787
sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1788
sap->attr.mls.cat->startbit = 0;
1789
1790
for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1791
for (m = 0x80; m != 0; m >>= 1, cat++) {
1792
if ((m & *cp) == 0)
1793
continue;
1794
rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1795
cat, GFP_ATOMIC);
1796
}
1797
}
1798
1799
/**
1800
* smack_to_secattr - fill a secattr from a smack value
1801
* @smack: the smack value
1802
* @nlsp: where the result goes
1803
*
1804
* Casey says that CIPSO is good enough for now.
1805
* It can be used to effect.
1806
* It can also be abused to effect when necessary.
1807
* Apologies to the TSIG group in general and GW in particular.
1808
*/
1809
static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1810
{
1811
struct smack_cipso cipso;
1812
int rc;
1813
1814
nlsp->domain = smack;
1815
nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1816
1817
rc = smack_to_cipso(smack, &cipso);
1818
if (rc == 0) {
1819
nlsp->attr.mls.lvl = cipso.smk_level;
1820
smack_set_catset(cipso.smk_catset, nlsp);
1821
} else {
1822
nlsp->attr.mls.lvl = smack_cipso_direct;
1823
smack_set_catset(smack, nlsp);
1824
}
1825
}
1826
1827
/**
1828
* smack_netlabel - Set the secattr on a socket
1829
* @sk: the socket
1830
* @labeled: socket label scheme
1831
*
1832
* Convert the outbound smack value (smk_out) to a
1833
* secattr and attach it to the socket.
1834
*
1835
* Returns 0 on success or an error code
1836
*/
1837
static int smack_netlabel(struct sock *sk, int labeled)
1838
{
1839
struct socket_smack *ssp = sk->sk_security;
1840
struct netlbl_lsm_secattr secattr;
1841
int rc = 0;
1842
1843
/*
1844
* Usually the netlabel code will handle changing the
1845
* packet labeling based on the label.
1846
* The case of a single label host is different, because
1847
* a single label host should never get a labeled packet
1848
* even though the label is usually associated with a packet
1849
* label.
1850
*/
1851
local_bh_disable();
1852
bh_lock_sock_nested(sk);
1853
1854
if (ssp->smk_out == smack_net_ambient ||
1855
labeled == SMACK_UNLABELED_SOCKET)
1856
netlbl_sock_delattr(sk);
1857
else {
1858
netlbl_secattr_init(&secattr);
1859
smack_to_secattr(ssp->smk_out, &secattr);
1860
rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr);
1861
netlbl_secattr_destroy(&secattr);
1862
}
1863
1864
bh_unlock_sock(sk);
1865
local_bh_enable();
1866
1867
return rc;
1868
}
1869
1870
/**
1871
* smack_netlbel_send - Set the secattr on a socket and perform access checks
1872
* @sk: the socket
1873
* @sap: the destination address
1874
*
1875
* Set the correct secattr for the given socket based on the destination
1876
* address and perform any outbound access checks needed.
1877
*
1878
* Returns 0 on success or an error code.
1879
*
1880
*/
1881
static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1882
{
1883
int rc;
1884
int sk_lbl;
1885
char *hostsp;
1886
struct socket_smack *ssp = sk->sk_security;
1887
struct smk_audit_info ad;
1888
1889
rcu_read_lock();
1890
hostsp = smack_host_label(sap);
1891
if (hostsp != NULL) {
1892
sk_lbl = SMACK_UNLABELED_SOCKET;
1893
#ifdef CONFIG_AUDIT
1894
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
1895
ad.a.u.net.family = sap->sin_family;
1896
ad.a.u.net.dport = sap->sin_port;
1897
ad.a.u.net.v4info.daddr = sap->sin_addr.s_addr;
1898
#endif
1899
rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1900
} else {
1901
sk_lbl = SMACK_CIPSO_SOCKET;
1902
rc = 0;
1903
}
1904
rcu_read_unlock();
1905
if (rc != 0)
1906
return rc;
1907
1908
return smack_netlabel(sk, sk_lbl);
1909
}
1910
1911
/**
1912
* smack_inode_setsecurity - set smack xattrs
1913
* @inode: the object
1914
* @name: attribute name
1915
* @value: attribute value
1916
* @size: size of the attribute
1917
* @flags: unused
1918
*
1919
* Sets the named attribute in the appropriate blob
1920
*
1921
* Returns 0 on success, or an error code
1922
*/
1923
static int smack_inode_setsecurity(struct inode *inode, const char *name,
1924
const void *value, size_t size, int flags)
1925
{
1926
char *sp;
1927
struct inode_smack *nsp = inode->i_security;
1928
struct socket_smack *ssp;
1929
struct socket *sock;
1930
int rc = 0;
1931
1932
if (value == NULL || size > SMK_LABELLEN || size == 0)
1933
return -EACCES;
1934
1935
sp = smk_import(value, size);
1936
if (sp == NULL)
1937
return -EINVAL;
1938
1939
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1940
nsp->smk_inode = sp;
1941
nsp->smk_flags |= SMK_INODE_INSTANT;
1942
return 0;
1943
}
1944
/*
1945
* The rest of the Smack xattrs are only on sockets.
1946
*/
1947
if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1948
return -EOPNOTSUPP;
1949
1950
sock = SOCKET_I(inode);
1951
if (sock == NULL || sock->sk == NULL)
1952
return -EOPNOTSUPP;
1953
1954
ssp = sock->sk->sk_security;
1955
1956
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1957
ssp->smk_in = sp;
1958
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1959
ssp->smk_out = sp;
1960
if (sock->sk->sk_family != PF_UNIX) {
1961
rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1962
if (rc != 0)
1963
printk(KERN_WARNING
1964
"Smack: \"%s\" netlbl error %d.\n",
1965
__func__, -rc);
1966
}
1967
} else
1968
return -EOPNOTSUPP;
1969
1970
return 0;
1971
}
1972
1973
/**
1974
* smack_socket_post_create - finish socket setup
1975
* @sock: the socket
1976
* @family: protocol family
1977
* @type: unused
1978
* @protocol: unused
1979
* @kern: unused
1980
*
1981
* Sets the netlabel information on the socket
1982
*
1983
* Returns 0 on success, and error code otherwise
1984
*/
1985
static int smack_socket_post_create(struct socket *sock, int family,
1986
int type, int protocol, int kern)
1987
{
1988
if (family != PF_INET || sock->sk == NULL)
1989
return 0;
1990
/*
1991
* Set the outbound netlbl.
1992
*/
1993
return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1994
}
1995
1996
/**
1997
* smack_socket_connect - connect access check
1998
* @sock: the socket
1999
* @sap: the other end
2000
* @addrlen: size of sap
2001
*
2002
* Verifies that a connection may be possible
2003
*
2004
* Returns 0 on success, and error code otherwise
2005
*/
2006
static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2007
int addrlen)
2008
{
2009
if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
2010
return 0;
2011
if (addrlen < sizeof(struct sockaddr_in))
2012
return -EINVAL;
2013
2014
return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2015
}
2016
2017
/**
2018
* smack_flags_to_may - convert S_ to MAY_ values
2019
* @flags: the S_ value
2020
*
2021
* Returns the equivalent MAY_ value
2022
*/
2023
static int smack_flags_to_may(int flags)
2024
{
2025
int may = 0;
2026
2027
if (flags & S_IRUGO)
2028
may |= MAY_READ;
2029
if (flags & S_IWUGO)
2030
may |= MAY_WRITE;
2031
if (flags & S_IXUGO)
2032
may |= MAY_EXEC;
2033
2034
return may;
2035
}
2036
2037
/**
2038
* smack_msg_msg_alloc_security - Set the security blob for msg_msg
2039
* @msg: the object
2040
*
2041
* Returns 0
2042
*/
2043
static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2044
{
2045
msg->security = smk_of_current();
2046
return 0;
2047
}
2048
2049
/**
2050
* smack_msg_msg_free_security - Clear the security blob for msg_msg
2051
* @msg: the object
2052
*
2053
* Clears the blob pointer
2054
*/
2055
static void smack_msg_msg_free_security(struct msg_msg *msg)
2056
{
2057
msg->security = NULL;
2058
}
2059
2060
/**
2061
* smack_of_shm - the smack pointer for the shm
2062
* @shp: the object
2063
*
2064
* Returns a pointer to the smack value
2065
*/
2066
static char *smack_of_shm(struct shmid_kernel *shp)
2067
{
2068
return (char *)shp->shm_perm.security;
2069
}
2070
2071
/**
2072
* smack_shm_alloc_security - Set the security blob for shm
2073
* @shp: the object
2074
*
2075
* Returns 0
2076
*/
2077
static int smack_shm_alloc_security(struct shmid_kernel *shp)
2078
{
2079
struct kern_ipc_perm *isp = &shp->shm_perm;
2080
2081
isp->security = smk_of_current();
2082
return 0;
2083
}
2084
2085
/**
2086
* smack_shm_free_security - Clear the security blob for shm
2087
* @shp: the object
2088
*
2089
* Clears the blob pointer
2090
*/
2091
static void smack_shm_free_security(struct shmid_kernel *shp)
2092
{
2093
struct kern_ipc_perm *isp = &shp->shm_perm;
2094
2095
isp->security = NULL;
2096
}
2097
2098
/**
2099
* smk_curacc_shm : check if current has access on shm
2100
* @shp : the object
2101
* @access : access requested
2102
*
2103
* Returns 0 if current has the requested access, error code otherwise
2104
*/
2105
static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2106
{
2107
char *ssp = smack_of_shm(shp);
2108
struct smk_audit_info ad;
2109
2110
#ifdef CONFIG_AUDIT
2111
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2112
ad.a.u.ipc_id = shp->shm_perm.id;
2113
#endif
2114
return smk_curacc(ssp, access, &ad);
2115
}
2116
2117
/**
2118
* smack_shm_associate - Smack access check for shm
2119
* @shp: the object
2120
* @shmflg: access requested
2121
*
2122
* Returns 0 if current has the requested access, error code otherwise
2123
*/
2124
static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2125
{
2126
int may;
2127
2128
may = smack_flags_to_may(shmflg);
2129
return smk_curacc_shm(shp, may);
2130
}
2131
2132
/**
2133
* smack_shm_shmctl - Smack access check for shm
2134
* @shp: the object
2135
* @cmd: what it wants to do
2136
*
2137
* Returns 0 if current has the requested access, error code otherwise
2138
*/
2139
static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2140
{
2141
int may;
2142
2143
switch (cmd) {
2144
case IPC_STAT:
2145
case SHM_STAT:
2146
may = MAY_READ;
2147
break;
2148
case IPC_SET:
2149
case SHM_LOCK:
2150
case SHM_UNLOCK:
2151
case IPC_RMID:
2152
may = MAY_READWRITE;
2153
break;
2154
case IPC_INFO:
2155
case SHM_INFO:
2156
/*
2157
* System level information.
2158
*/
2159
return 0;
2160
default:
2161
return -EINVAL;
2162
}
2163
return smk_curacc_shm(shp, may);
2164
}
2165
2166
/**
2167
* smack_shm_shmat - Smack access for shmat
2168
* @shp: the object
2169
* @shmaddr: unused
2170
* @shmflg: access requested
2171
*
2172
* Returns 0 if current has the requested access, error code otherwise
2173
*/
2174
static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2175
int shmflg)
2176
{
2177
int may;
2178
2179
may = smack_flags_to_may(shmflg);
2180
return smk_curacc_shm(shp, may);
2181
}
2182
2183
/**
2184
* smack_of_sem - the smack pointer for the sem
2185
* @sma: the object
2186
*
2187
* Returns a pointer to the smack value
2188
*/
2189
static char *smack_of_sem(struct sem_array *sma)
2190
{
2191
return (char *)sma->sem_perm.security;
2192
}
2193
2194
/**
2195
* smack_sem_alloc_security - Set the security blob for sem
2196
* @sma: the object
2197
*
2198
* Returns 0
2199
*/
2200
static int smack_sem_alloc_security(struct sem_array *sma)
2201
{
2202
struct kern_ipc_perm *isp = &sma->sem_perm;
2203
2204
isp->security = smk_of_current();
2205
return 0;
2206
}
2207
2208
/**
2209
* smack_sem_free_security - Clear the security blob for sem
2210
* @sma: the object
2211
*
2212
* Clears the blob pointer
2213
*/
2214
static void smack_sem_free_security(struct sem_array *sma)
2215
{
2216
struct kern_ipc_perm *isp = &sma->sem_perm;
2217
2218
isp->security = NULL;
2219
}
2220
2221
/**
2222
* smk_curacc_sem : check if current has access on sem
2223
* @sma : the object
2224
* @access : access requested
2225
*
2226
* Returns 0 if current has the requested access, error code otherwise
2227
*/
2228
static int smk_curacc_sem(struct sem_array *sma, int access)
2229
{
2230
char *ssp = smack_of_sem(sma);
2231
struct smk_audit_info ad;
2232
2233
#ifdef CONFIG_AUDIT
2234
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2235
ad.a.u.ipc_id = sma->sem_perm.id;
2236
#endif
2237
return smk_curacc(ssp, access, &ad);
2238
}
2239
2240
/**
2241
* smack_sem_associate - Smack access check for sem
2242
* @sma: the object
2243
* @semflg: access requested
2244
*
2245
* Returns 0 if current has the requested access, error code otherwise
2246
*/
2247
static int smack_sem_associate(struct sem_array *sma, int semflg)
2248
{
2249
int may;
2250
2251
may = smack_flags_to_may(semflg);
2252
return smk_curacc_sem(sma, may);
2253
}
2254
2255
/**
2256
* smack_sem_shmctl - Smack access check for sem
2257
* @sma: the object
2258
* @cmd: what it wants to do
2259
*
2260
* Returns 0 if current has the requested access, error code otherwise
2261
*/
2262
static int smack_sem_semctl(struct sem_array *sma, int cmd)
2263
{
2264
int may;
2265
2266
switch (cmd) {
2267
case GETPID:
2268
case GETNCNT:
2269
case GETZCNT:
2270
case GETVAL:
2271
case GETALL:
2272
case IPC_STAT:
2273
case SEM_STAT:
2274
may = MAY_READ;
2275
break;
2276
case SETVAL:
2277
case SETALL:
2278
case IPC_RMID:
2279
case IPC_SET:
2280
may = MAY_READWRITE;
2281
break;
2282
case IPC_INFO:
2283
case SEM_INFO:
2284
/*
2285
* System level information
2286
*/
2287
return 0;
2288
default:
2289
return -EINVAL;
2290
}
2291
2292
return smk_curacc_sem(sma, may);
2293
}
2294
2295
/**
2296
* smack_sem_semop - Smack checks of semaphore operations
2297
* @sma: the object
2298
* @sops: unused
2299
* @nsops: unused
2300
* @alter: unused
2301
*
2302
* Treated as read and write in all cases.
2303
*
2304
* Returns 0 if access is allowed, error code otherwise
2305
*/
2306
static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2307
unsigned nsops, int alter)
2308
{
2309
return smk_curacc_sem(sma, MAY_READWRITE);
2310
}
2311
2312
/**
2313
* smack_msg_alloc_security - Set the security blob for msg
2314
* @msq: the object
2315
*
2316
* Returns 0
2317
*/
2318
static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2319
{
2320
struct kern_ipc_perm *kisp = &msq->q_perm;
2321
2322
kisp->security = smk_of_current();
2323
return 0;
2324
}
2325
2326
/**
2327
* smack_msg_free_security - Clear the security blob for msg
2328
* @msq: the object
2329
*
2330
* Clears the blob pointer
2331
*/
2332
static void smack_msg_queue_free_security(struct msg_queue *msq)
2333
{
2334
struct kern_ipc_perm *kisp = &msq->q_perm;
2335
2336
kisp->security = NULL;
2337
}
2338
2339
/**
2340
* smack_of_msq - the smack pointer for the msq
2341
* @msq: the object
2342
*
2343
* Returns a pointer to the smack value
2344
*/
2345
static char *smack_of_msq(struct msg_queue *msq)
2346
{
2347
return (char *)msq->q_perm.security;
2348
}
2349
2350
/**
2351
* smk_curacc_msq : helper to check if current has access on msq
2352
* @msq : the msq
2353
* @access : access requested
2354
*
2355
* return 0 if current has access, error otherwise
2356
*/
2357
static int smk_curacc_msq(struct msg_queue *msq, int access)
2358
{
2359
char *msp = smack_of_msq(msq);
2360
struct smk_audit_info ad;
2361
2362
#ifdef CONFIG_AUDIT
2363
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2364
ad.a.u.ipc_id = msq->q_perm.id;
2365
#endif
2366
return smk_curacc(msp, access, &ad);
2367
}
2368
2369
/**
2370
* smack_msg_queue_associate - Smack access check for msg_queue
2371
* @msq: the object
2372
* @msqflg: access requested
2373
*
2374
* Returns 0 if current has the requested access, error code otherwise
2375
*/
2376
static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2377
{
2378
int may;
2379
2380
may = smack_flags_to_may(msqflg);
2381
return smk_curacc_msq(msq, may);
2382
}
2383
2384
/**
2385
* smack_msg_queue_msgctl - Smack access check for msg_queue
2386
* @msq: the object
2387
* @cmd: what it wants to do
2388
*
2389
* Returns 0 if current has the requested access, error code otherwise
2390
*/
2391
static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2392
{
2393
int may;
2394
2395
switch (cmd) {
2396
case IPC_STAT:
2397
case MSG_STAT:
2398
may = MAY_READ;
2399
break;
2400
case IPC_SET:
2401
case IPC_RMID:
2402
may = MAY_READWRITE;
2403
break;
2404
case IPC_INFO:
2405
case MSG_INFO:
2406
/*
2407
* System level information
2408
*/
2409
return 0;
2410
default:
2411
return -EINVAL;
2412
}
2413
2414
return smk_curacc_msq(msq, may);
2415
}
2416
2417
/**
2418
* smack_msg_queue_msgsnd - Smack access check for msg_queue
2419
* @msq: the object
2420
* @msg: unused
2421
* @msqflg: access requested
2422
*
2423
* Returns 0 if current has the requested access, error code otherwise
2424
*/
2425
static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2426
int msqflg)
2427
{
2428
int may;
2429
2430
may = smack_flags_to_may(msqflg);
2431
return smk_curacc_msq(msq, may);
2432
}
2433
2434
/**
2435
* smack_msg_queue_msgsnd - Smack access check for msg_queue
2436
* @msq: the object
2437
* @msg: unused
2438
* @target: unused
2439
* @type: unused
2440
* @mode: unused
2441
*
2442
* Returns 0 if current has read and write access, error code otherwise
2443
*/
2444
static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2445
struct task_struct *target, long type, int mode)
2446
{
2447
return smk_curacc_msq(msq, MAY_READWRITE);
2448
}
2449
2450
/**
2451
* smack_ipc_permission - Smack access for ipc_permission()
2452
* @ipp: the object permissions
2453
* @flag: access requested
2454
*
2455
* Returns 0 if current has read and write access, error code otherwise
2456
*/
2457
static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2458
{
2459
char *isp = ipp->security;
2460
int may = smack_flags_to_may(flag);
2461
struct smk_audit_info ad;
2462
2463
#ifdef CONFIG_AUDIT
2464
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2465
ad.a.u.ipc_id = ipp->id;
2466
#endif
2467
return smk_curacc(isp, may, &ad);
2468
}
2469
2470
/**
2471
* smack_ipc_getsecid - Extract smack security id
2472
* @ipp: the object permissions
2473
* @secid: where result will be saved
2474
*/
2475
static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2476
{
2477
char *smack = ipp->security;
2478
2479
*secid = smack_to_secid(smack);
2480
}
2481
2482
/**
2483
* smack_d_instantiate - Make sure the blob is correct on an inode
2484
* @opt_dentry: dentry where inode will be attached
2485
* @inode: the object
2486
*
2487
* Set the inode's security blob if it hasn't been done already.
2488
*/
2489
static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2490
{
2491
struct super_block *sbp;
2492
struct superblock_smack *sbsp;
2493
struct inode_smack *isp;
2494
char *csp = smk_of_current();
2495
char *fetched;
2496
char *final;
2497
char trattr[TRANS_TRUE_SIZE];
2498
int transflag = 0;
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
if (S_ISDIR(inode->i_mode)) {
2620
trattr[0] = '\0';
2621
inode->i_op->getxattr(dp,
2622
XATTR_NAME_SMACKTRANSMUTE,
2623
trattr, TRANS_TRUE_SIZE);
2624
if (strncmp(trattr, TRANS_TRUE,
2625
TRANS_TRUE_SIZE) == 0)
2626
transflag = SMK_INODE_TRANSMUTE;
2627
}
2628
}
2629
isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2630
isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2631
2632
dput(dp);
2633
break;
2634
}
2635
2636
if (final == NULL)
2637
isp->smk_inode = csp;
2638
else
2639
isp->smk_inode = final;
2640
2641
isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2642
2643
unlockandout:
2644
mutex_unlock(&isp->smk_lock);
2645
return;
2646
}
2647
2648
/**
2649
* smack_getprocattr - Smack process attribute access
2650
* @p: the object task
2651
* @name: the name of the attribute in /proc/.../attr
2652
* @value: where to put the result
2653
*
2654
* Places a copy of the task Smack into value
2655
*
2656
* Returns the length of the smack label or an error code
2657
*/
2658
static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2659
{
2660
char *cp;
2661
int slen;
2662
2663
if (strcmp(name, "current") != 0)
2664
return -EINVAL;
2665
2666
cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2667
if (cp == NULL)
2668
return -ENOMEM;
2669
2670
slen = strlen(cp);
2671
*value = cp;
2672
return slen;
2673
}
2674
2675
/**
2676
* smack_setprocattr - Smack process attribute setting
2677
* @p: the object task
2678
* @name: the name of the attribute in /proc/.../attr
2679
* @value: the value to set
2680
* @size: the size of the value
2681
*
2682
* Sets the Smack value of the task. Only setting self
2683
* is permitted and only with privilege
2684
*
2685
* Returns the length of the smack label or an error code
2686
*/
2687
static int smack_setprocattr(struct task_struct *p, char *name,
2688
void *value, size_t size)
2689
{
2690
int rc;
2691
struct task_smack *tsp;
2692
struct task_smack *oldtsp;
2693
struct cred *new;
2694
char *newsmack;
2695
2696
/*
2697
* Changing another process' Smack value is too dangerous
2698
* and supports no sane use case.
2699
*/
2700
if (p != current)
2701
return -EPERM;
2702
2703
if (!capable(CAP_MAC_ADMIN))
2704
return -EPERM;
2705
2706
if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2707
return -EINVAL;
2708
2709
if (strcmp(name, "current") != 0)
2710
return -EINVAL;
2711
2712
newsmack = smk_import(value, size);
2713
if (newsmack == NULL)
2714
return -EINVAL;
2715
2716
/*
2717
* No process is ever allowed the web ("@") label.
2718
*/
2719
if (newsmack == smack_known_web.smk_known)
2720
return -EPERM;
2721
2722
oldtsp = p->cred->security;
2723
new = prepare_creds();
2724
if (new == NULL)
2725
return -ENOMEM;
2726
2727
tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
2728
if (tsp == NULL) {
2729
kfree(new);
2730
return -ENOMEM;
2731
}
2732
rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
2733
if (rc != 0)
2734
return rc;
2735
2736
new->security = tsp;
2737
commit_creds(new);
2738
return size;
2739
}
2740
2741
/**
2742
* smack_unix_stream_connect - Smack access on UDS
2743
* @sock: one sock
2744
* @other: the other sock
2745
* @newsk: unused
2746
*
2747
* Return 0 if a subject with the smack of sock could access
2748
* an object with the smack of other, otherwise an error code
2749
*/
2750
static int smack_unix_stream_connect(struct sock *sock,
2751
struct sock *other, struct sock *newsk)
2752
{
2753
struct socket_smack *ssp = sock->sk_security;
2754
struct socket_smack *osp = other->sk_security;
2755
struct smk_audit_info ad;
2756
int rc = 0;
2757
2758
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2759
smk_ad_setfield_u_net_sk(&ad, other);
2760
2761
if (!capable(CAP_MAC_OVERRIDE))
2762
rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2763
2764
return rc;
2765
}
2766
2767
/**
2768
* smack_unix_may_send - Smack access on UDS
2769
* @sock: one socket
2770
* @other: the other socket
2771
*
2772
* Return 0 if a subject with the smack of sock could access
2773
* an object with the smack of other, otherwise an error code
2774
*/
2775
static int smack_unix_may_send(struct socket *sock, struct socket *other)
2776
{
2777
struct socket_smack *ssp = sock->sk->sk_security;
2778
struct socket_smack *osp = other->sk->sk_security;
2779
struct smk_audit_info ad;
2780
int rc = 0;
2781
2782
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2783
smk_ad_setfield_u_net_sk(&ad, other->sk);
2784
2785
if (!capable(CAP_MAC_OVERRIDE))
2786
rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2787
2788
return rc;
2789
}
2790
2791
/**
2792
* smack_socket_sendmsg - Smack check based on destination host
2793
* @sock: the socket
2794
* @msg: the message
2795
* @size: the size of the message
2796
*
2797
* Return 0 if the current subject can write to the destination
2798
* host. This is only a question if the destination is a single
2799
* label host.
2800
*/
2801
static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2802
int size)
2803
{
2804
struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2805
2806
/*
2807
* Perfectly reasonable for this to be NULL
2808
*/
2809
if (sip == NULL || sip->sin_family != AF_INET)
2810
return 0;
2811
2812
return smack_netlabel_send(sock->sk, sip);
2813
}
2814
2815
2816
/**
2817
* smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2818
* @sap: netlabel secattr
2819
* @sip: where to put the result
2820
*
2821
* Copies a smack label into sip
2822
*/
2823
static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2824
{
2825
char smack[SMK_LABELLEN];
2826
char *sp;
2827
int pcat;
2828
2829
if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2830
/*
2831
* Looks like a CIPSO packet.
2832
* If there are flags but no level netlabel isn't
2833
* behaving the way we expect it to.
2834
*
2835
* Get the categories, if any
2836
* Without guidance regarding the smack value
2837
* for the packet fall back on the network
2838
* ambient value.
2839
*/
2840
memset(smack, '\0', SMK_LABELLEN);
2841
if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2842
for (pcat = -1;;) {
2843
pcat = netlbl_secattr_catmap_walk(
2844
sap->attr.mls.cat, pcat + 1);
2845
if (pcat < 0)
2846
break;
2847
smack_catset_bit(pcat, smack);
2848
}
2849
/*
2850
* If it is CIPSO using smack direct mapping
2851
* we are already done. WeeHee.
2852
*/
2853
if (sap->attr.mls.lvl == smack_cipso_direct) {
2854
memcpy(sip, smack, SMK_MAXLEN);
2855
return;
2856
}
2857
/*
2858
* Look it up in the supplied table if it is not
2859
* a direct mapping.
2860
*/
2861
smack_from_cipso(sap->attr.mls.lvl, smack, sip);
2862
return;
2863
}
2864
if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2865
/*
2866
* Looks like a fallback, which gives us a secid.
2867
*/
2868
sp = smack_from_secid(sap->attr.secid);
2869
/*
2870
* This has got to be a bug because it is
2871
* impossible to specify a fallback without
2872
* specifying the label, which will ensure
2873
* it has a secid, and the only way to get a
2874
* secid is from a fallback.
2875
*/
2876
BUG_ON(sp == NULL);
2877
strncpy(sip, sp, SMK_MAXLEN);
2878
return;
2879
}
2880
/*
2881
* Without guidance regarding the smack value
2882
* for the packet fall back on the network
2883
* ambient value.
2884
*/
2885
strncpy(sip, smack_net_ambient, SMK_MAXLEN);
2886
return;
2887
}
2888
2889
/**
2890
* smack_socket_sock_rcv_skb - Smack packet delivery access check
2891
* @sk: socket
2892
* @skb: packet
2893
*
2894
* Returns 0 if the packet should be delivered, an error code otherwise
2895
*/
2896
static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2897
{
2898
struct netlbl_lsm_secattr secattr;
2899
struct socket_smack *ssp = sk->sk_security;
2900
char smack[SMK_LABELLEN];
2901
char *csp;
2902
int rc;
2903
struct smk_audit_info ad;
2904
if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2905
return 0;
2906
2907
/*
2908
* Translate what netlabel gave us.
2909
*/
2910
netlbl_secattr_init(&secattr);
2911
2912
rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2913
if (rc == 0) {
2914
smack_from_secattr(&secattr, smack);
2915
csp = smack;
2916
} else
2917
csp = smack_net_ambient;
2918
2919
netlbl_secattr_destroy(&secattr);
2920
2921
#ifdef CONFIG_AUDIT
2922
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2923
ad.a.u.net.family = sk->sk_family;
2924
ad.a.u.net.netif = skb->skb_iif;
2925
ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2926
#endif
2927
/*
2928
* Receiving a packet requires that the other end
2929
* be able to write here. Read access is not required.
2930
* This is the simplist possible security model
2931
* for networking.
2932
*/
2933
rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2934
if (rc != 0)
2935
netlbl_skbuff_err(skb, rc, 0);
2936
return rc;
2937
}
2938
2939
/**
2940
* smack_socket_getpeersec_stream - pull in packet label
2941
* @sock: the socket
2942
* @optval: user's destination
2943
* @optlen: size thereof
2944
* @len: max thereof
2945
*
2946
* returns zero on success, an error code otherwise
2947
*/
2948
static int smack_socket_getpeersec_stream(struct socket *sock,
2949
char __user *optval,
2950
int __user *optlen, unsigned len)
2951
{
2952
struct socket_smack *ssp;
2953
int slen;
2954
int rc = 0;
2955
2956
ssp = sock->sk->sk_security;
2957
slen = strlen(ssp->smk_packet) + 1;
2958
2959
if (slen > len)
2960
rc = -ERANGE;
2961
else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2962
rc = -EFAULT;
2963
2964
if (put_user(slen, optlen) != 0)
2965
rc = -EFAULT;
2966
2967
return rc;
2968
}
2969
2970
2971
/**
2972
* smack_socket_getpeersec_dgram - pull in packet label
2973
* @sock: the peer socket
2974
* @skb: packet data
2975
* @secid: pointer to where to put the secid of the packet
2976
*
2977
* Sets the netlabel socket state on sk from parent
2978
*/
2979
static int smack_socket_getpeersec_dgram(struct socket *sock,
2980
struct sk_buff *skb, u32 *secid)
2981
2982
{
2983
struct netlbl_lsm_secattr secattr;
2984
struct socket_smack *sp;
2985
char smack[SMK_LABELLEN];
2986
int family = PF_UNSPEC;
2987
u32 s = 0; /* 0 is the invalid secid */
2988
int rc;
2989
2990
if (skb != NULL) {
2991
if (skb->protocol == htons(ETH_P_IP))
2992
family = PF_INET;
2993
else if (skb->protocol == htons(ETH_P_IPV6))
2994
family = PF_INET6;
2995
}
2996
if (family == PF_UNSPEC && sock != NULL)
2997
family = sock->sk->sk_family;
2998
2999
if (family == PF_UNIX) {
3000
sp = sock->sk->sk_security;
3001
s = smack_to_secid(sp->smk_out);
3002
} else if (family == PF_INET || family == PF_INET6) {
3003
/*
3004
* Translate what netlabel gave us.
3005
*/
3006
netlbl_secattr_init(&secattr);
3007
rc = netlbl_skbuff_getattr(skb, family, &secattr);
3008
if (rc == 0) {
3009
smack_from_secattr(&secattr, smack);
3010
s = smack_to_secid(smack);
3011
}
3012
netlbl_secattr_destroy(&secattr);
3013
}
3014
*secid = s;
3015
if (s == 0)
3016
return -EINVAL;
3017
return 0;
3018
}
3019
3020
/**
3021
* smack_sock_graft - Initialize a newly created socket with an existing sock
3022
* @sk: child sock
3023
* @parent: parent socket
3024
*
3025
* Set the smk_{in,out} state of an existing sock based on the process that
3026
* is creating the new socket.
3027
*/
3028
static void smack_sock_graft(struct sock *sk, struct socket *parent)
3029
{
3030
struct socket_smack *ssp;
3031
3032
if (sk == NULL ||
3033
(sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3034
return;
3035
3036
ssp = sk->sk_security;
3037
ssp->smk_in = ssp->smk_out = smk_of_current();
3038
/* cssp->smk_packet is already set in smack_inet_csk_clone() */
3039
}
3040
3041
/**
3042
* smack_inet_conn_request - Smack access check on connect
3043
* @sk: socket involved
3044
* @skb: packet
3045
* @req: unused
3046
*
3047
* Returns 0 if a task with the packet label could write to
3048
* the socket, otherwise an error code
3049
*/
3050
static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3051
struct request_sock *req)
3052
{
3053
u16 family = sk->sk_family;
3054
struct socket_smack *ssp = sk->sk_security;
3055
struct netlbl_lsm_secattr secattr;
3056
struct sockaddr_in addr;
3057
struct iphdr *hdr;
3058
char smack[SMK_LABELLEN];
3059
int rc;
3060
struct smk_audit_info ad;
3061
3062
/* handle mapped IPv4 packets arriving via IPv6 sockets */
3063
if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3064
family = PF_INET;
3065
3066
netlbl_secattr_init(&secattr);
3067
rc = netlbl_skbuff_getattr(skb, family, &secattr);
3068
if (rc == 0)
3069
smack_from_secattr(&secattr, smack);
3070
else
3071
strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
3072
netlbl_secattr_destroy(&secattr);
3073
3074
#ifdef CONFIG_AUDIT
3075
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
3076
ad.a.u.net.family = family;
3077
ad.a.u.net.netif = skb->skb_iif;
3078
ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3079
#endif
3080
/*
3081
* Receiving a packet requires that the other end be able to write
3082
* here. Read access is not required.
3083
*/
3084
rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
3085
if (rc != 0)
3086
return rc;
3087
3088
/*
3089
* Save the peer's label in the request_sock so we can later setup
3090
* smk_packet in the child socket so that SO_PEERCRED can report it.
3091
*/
3092
req->peer_secid = smack_to_secid(smack);
3093
3094
/*
3095
* We need to decide if we want to label the incoming connection here
3096
* if we do we only need to label the request_sock and the stack will
3097
* propagate the wire-label to the sock when it is created.
3098
*/
3099
hdr = ip_hdr(skb);
3100
addr.sin_addr.s_addr = hdr->saddr;
3101
rcu_read_lock();
3102
if (smack_host_label(&addr) == NULL) {
3103
rcu_read_unlock();
3104
netlbl_secattr_init(&secattr);
3105
smack_to_secattr(smack, &secattr);
3106
rc = netlbl_req_setattr(req, &secattr);
3107
netlbl_secattr_destroy(&secattr);
3108
} else {
3109
rcu_read_unlock();
3110
netlbl_req_delattr(req);
3111
}
3112
3113
return rc;
3114
}
3115
3116
/**
3117
* smack_inet_csk_clone - Copy the connection information to the new socket
3118
* @sk: the new socket
3119
* @req: the connection's request_sock
3120
*
3121
* Transfer the connection's peer label to the newly created socket.
3122
*/
3123
static void smack_inet_csk_clone(struct sock *sk,
3124
const struct request_sock *req)
3125
{
3126
struct socket_smack *ssp = sk->sk_security;
3127
char *smack;
3128
3129
if (req->peer_secid != 0) {
3130
smack = smack_from_secid(req->peer_secid);
3131
strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
3132
} else
3133
ssp->smk_packet[0] = '\0';
3134
}
3135
3136
/*
3137
* Key management security hooks
3138
*
3139
* Casey has not tested key support very heavily.
3140
* The permission check is most likely too restrictive.
3141
* If you care about keys please have a look.
3142
*/
3143
#ifdef CONFIG_KEYS
3144
3145
/**
3146
* smack_key_alloc - Set the key security blob
3147
* @key: object
3148
* @cred: the credentials to use
3149
* @flags: unused
3150
*
3151
* No allocation required
3152
*
3153
* Returns 0
3154
*/
3155
static int smack_key_alloc(struct key *key, const struct cred *cred,
3156
unsigned long flags)
3157
{
3158
key->security = smk_of_task(cred->security);
3159
return 0;
3160
}
3161
3162
/**
3163
* smack_key_free - Clear the key security blob
3164
* @key: the object
3165
*
3166
* Clear the blob pointer
3167
*/
3168
static void smack_key_free(struct key *key)
3169
{
3170
key->security = NULL;
3171
}
3172
3173
/*
3174
* smack_key_permission - Smack access on a key
3175
* @key_ref: gets to the object
3176
* @cred: the credentials to use
3177
* @perm: unused
3178
*
3179
* Return 0 if the task has read and write to the object,
3180
* an error code otherwise
3181
*/
3182
static int smack_key_permission(key_ref_t key_ref,
3183
const struct cred *cred, key_perm_t perm)
3184
{
3185
struct key *keyp;
3186
struct smk_audit_info ad;
3187
char *tsp = smk_of_task(cred->security);
3188
3189
keyp = key_ref_to_ptr(key_ref);
3190
if (keyp == NULL)
3191
return -EINVAL;
3192
/*
3193
* If the key hasn't been initialized give it access so that
3194
* it may do so.
3195
*/
3196
if (keyp->security == NULL)
3197
return 0;
3198
/*
3199
* This should not occur
3200
*/
3201
if (tsp == NULL)
3202
return -EACCES;
3203
#ifdef CONFIG_AUDIT
3204
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3205
ad.a.u.key_struct.key = keyp->serial;
3206
ad.a.u.key_struct.key_desc = keyp->description;
3207
#endif
3208
return smk_access(tsp, keyp->security,
3209
MAY_READWRITE, &ad);
3210
}
3211
#endif /* CONFIG_KEYS */
3212
3213
/*
3214
* Smack Audit hooks
3215
*
3216
* Audit requires a unique representation of each Smack specific
3217
* rule. This unique representation is used to distinguish the
3218
* object to be audited from remaining kernel objects and also
3219
* works as a glue between the audit hooks.
3220
*
3221
* Since repository entries are added but never deleted, we'll use
3222
* the smack_known label address related to the given audit rule as
3223
* the needed unique representation. This also better fits the smack
3224
* model where nearly everything is a label.
3225
*/
3226
#ifdef CONFIG_AUDIT
3227
3228
/**
3229
* smack_audit_rule_init - Initialize a smack audit rule
3230
* @field: audit rule fields given from user-space (audit.h)
3231
* @op: required testing operator (=, !=, >, <, ...)
3232
* @rulestr: smack label to be audited
3233
* @vrule: pointer to save our own audit rule representation
3234
*
3235
* Prepare to audit cases where (@field @op @rulestr) is true.
3236
* The label to be audited is created if necessay.
3237
*/
3238
static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3239
{
3240
char **rule = (char **)vrule;
3241
*rule = NULL;
3242
3243
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3244
return -EINVAL;
3245
3246
if (op != Audit_equal && op != Audit_not_equal)
3247
return -EINVAL;
3248
3249
*rule = smk_import(rulestr, 0);
3250
3251
return 0;
3252
}
3253
3254
/**
3255
* smack_audit_rule_known - Distinguish Smack audit rules
3256
* @krule: rule of interest, in Audit kernel representation format
3257
*
3258
* This is used to filter Smack rules from remaining Audit ones.
3259
* If it's proved that this rule belongs to us, the
3260
* audit_rule_match hook will be called to do the final judgement.
3261
*/
3262
static int smack_audit_rule_known(struct audit_krule *krule)
3263
{
3264
struct audit_field *f;
3265
int i;
3266
3267
for (i = 0; i < krule->field_count; i++) {
3268
f = &krule->fields[i];
3269
3270
if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3271
return 1;
3272
}
3273
3274
return 0;
3275
}
3276
3277
/**
3278
* smack_audit_rule_match - Audit given object ?
3279
* @secid: security id for identifying the object to test
3280
* @field: audit rule flags given from user-space
3281
* @op: required testing operator
3282
* @vrule: smack internal rule presentation
3283
* @actx: audit context associated with the check
3284
*
3285
* The core Audit hook. It's used to take the decision of
3286
* whether to audit or not to audit a given object.
3287
*/
3288
static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3289
struct audit_context *actx)
3290
{
3291
char *smack;
3292
char *rule = vrule;
3293
3294
if (!rule) {
3295
audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
3296
"Smack: missing rule\n");
3297
return -ENOENT;
3298
}
3299
3300
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3301
return 0;
3302
3303
smack = smack_from_secid(secid);
3304
3305
/*
3306
* No need to do string comparisons. If a match occurs,
3307
* both pointers will point to the same smack_known
3308
* label.
3309
*/
3310
if (op == Audit_equal)
3311
return (rule == smack);
3312
if (op == Audit_not_equal)
3313
return (rule != smack);
3314
3315
return 0;
3316
}
3317
3318
/**
3319
* smack_audit_rule_free - free smack rule representation
3320
* @vrule: rule to be freed.
3321
*
3322
* No memory was allocated.
3323
*/
3324
static void smack_audit_rule_free(void *vrule)
3325
{
3326
/* No-op */
3327
}
3328
3329
#endif /* CONFIG_AUDIT */
3330
3331
/**
3332
* smack_secid_to_secctx - return the smack label for a secid
3333
* @secid: incoming integer
3334
* @secdata: destination
3335
* @seclen: how long it is
3336
*
3337
* Exists for networking code.
3338
*/
3339
static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3340
{
3341
char *sp = smack_from_secid(secid);
3342
3343
if (secdata)
3344
*secdata = sp;
3345
*seclen = strlen(sp);
3346
return 0;
3347
}
3348
3349
/**
3350
* smack_secctx_to_secid - return the secid for a smack label
3351
* @secdata: smack label
3352
* @seclen: how long result is
3353
* @secid: outgoing integer
3354
*
3355
* Exists for audit and networking code.
3356
*/
3357
static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3358
{
3359
*secid = smack_to_secid(secdata);
3360
return 0;
3361
}
3362
3363
/**
3364
* smack_release_secctx - don't do anything.
3365
* @secdata: unused
3366
* @seclen: unused
3367
*
3368
* Exists to make sure nothing gets done, and properly
3369
*/
3370
static void smack_release_secctx(char *secdata, u32 seclen)
3371
{
3372
}
3373
3374
static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3375
{
3376
return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3377
}
3378
3379
static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3380
{
3381
return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3382
}
3383
3384
static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3385
{
3386
int len = 0;
3387
len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3388
3389
if (len < 0)
3390
return len;
3391
*ctxlen = len;
3392
return 0;
3393
}
3394
3395
struct security_operations smack_ops = {
3396
.name = "smack",
3397
3398
.ptrace_access_check = smack_ptrace_access_check,
3399
.ptrace_traceme = smack_ptrace_traceme,
3400
.syslog = smack_syslog,
3401
3402
.sb_alloc_security = smack_sb_alloc_security,
3403
.sb_free_security = smack_sb_free_security,
3404
.sb_copy_data = smack_sb_copy_data,
3405
.sb_kern_mount = smack_sb_kern_mount,
3406
.sb_statfs = smack_sb_statfs,
3407
.sb_mount = smack_sb_mount,
3408
.sb_umount = smack_sb_umount,
3409
3410
.bprm_set_creds = smack_bprm_set_creds,
3411
3412
.inode_alloc_security = smack_inode_alloc_security,
3413
.inode_free_security = smack_inode_free_security,
3414
.inode_init_security = smack_inode_init_security,
3415
.inode_link = smack_inode_link,
3416
.inode_unlink = smack_inode_unlink,
3417
.inode_rmdir = smack_inode_rmdir,
3418
.inode_rename = smack_inode_rename,
3419
.inode_permission = smack_inode_permission,
3420
.inode_setattr = smack_inode_setattr,
3421
.inode_getattr = smack_inode_getattr,
3422
.inode_setxattr = smack_inode_setxattr,
3423
.inode_post_setxattr = smack_inode_post_setxattr,
3424
.inode_getxattr = smack_inode_getxattr,
3425
.inode_removexattr = smack_inode_removexattr,
3426
.inode_getsecurity = smack_inode_getsecurity,
3427
.inode_setsecurity = smack_inode_setsecurity,
3428
.inode_listsecurity = smack_inode_listsecurity,
3429
.inode_getsecid = smack_inode_getsecid,
3430
3431
.file_permission = smack_file_permission,
3432
.file_alloc_security = smack_file_alloc_security,
3433
.file_free_security = smack_file_free_security,
3434
.file_ioctl = smack_file_ioctl,
3435
.file_lock = smack_file_lock,
3436
.file_fcntl = smack_file_fcntl,
3437
.file_mmap = smack_file_mmap,
3438
.file_set_fowner = smack_file_set_fowner,
3439
.file_send_sigiotask = smack_file_send_sigiotask,
3440
.file_receive = smack_file_receive,
3441
3442
.cred_alloc_blank = smack_cred_alloc_blank,
3443
.cred_free = smack_cred_free,
3444
.cred_prepare = smack_cred_prepare,
3445
.cred_transfer = smack_cred_transfer,
3446
.kernel_act_as = smack_kernel_act_as,
3447
.kernel_create_files_as = smack_kernel_create_files_as,
3448
.task_setpgid = smack_task_setpgid,
3449
.task_getpgid = smack_task_getpgid,
3450
.task_getsid = smack_task_getsid,
3451
.task_getsecid = smack_task_getsecid,
3452
.task_setnice = smack_task_setnice,
3453
.task_setioprio = smack_task_setioprio,
3454
.task_getioprio = smack_task_getioprio,
3455
.task_setscheduler = smack_task_setscheduler,
3456
.task_getscheduler = smack_task_getscheduler,
3457
.task_movememory = smack_task_movememory,
3458
.task_kill = smack_task_kill,
3459
.task_wait = smack_task_wait,
3460
.task_to_inode = smack_task_to_inode,
3461
3462
.ipc_permission = smack_ipc_permission,
3463
.ipc_getsecid = smack_ipc_getsecid,
3464
3465
.msg_msg_alloc_security = smack_msg_msg_alloc_security,
3466
.msg_msg_free_security = smack_msg_msg_free_security,
3467
3468
.msg_queue_alloc_security = smack_msg_queue_alloc_security,
3469
.msg_queue_free_security = smack_msg_queue_free_security,
3470
.msg_queue_associate = smack_msg_queue_associate,
3471
.msg_queue_msgctl = smack_msg_queue_msgctl,
3472
.msg_queue_msgsnd = smack_msg_queue_msgsnd,
3473
.msg_queue_msgrcv = smack_msg_queue_msgrcv,
3474
3475
.shm_alloc_security = smack_shm_alloc_security,
3476
.shm_free_security = smack_shm_free_security,
3477
.shm_associate = smack_shm_associate,
3478
.shm_shmctl = smack_shm_shmctl,
3479
.shm_shmat = smack_shm_shmat,
3480
3481
.sem_alloc_security = smack_sem_alloc_security,
3482
.sem_free_security = smack_sem_free_security,
3483
.sem_associate = smack_sem_associate,
3484
.sem_semctl = smack_sem_semctl,
3485
.sem_semop = smack_sem_semop,
3486
3487
.d_instantiate = smack_d_instantiate,
3488
3489
.getprocattr = smack_getprocattr,
3490
.setprocattr = smack_setprocattr,
3491
3492
.unix_stream_connect = smack_unix_stream_connect,
3493
.unix_may_send = smack_unix_may_send,
3494
3495
.socket_post_create = smack_socket_post_create,
3496
.socket_connect = smack_socket_connect,
3497
.socket_sendmsg = smack_socket_sendmsg,
3498
.socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
3499
.socket_getpeersec_stream = smack_socket_getpeersec_stream,
3500
.socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
3501
.sk_alloc_security = smack_sk_alloc_security,
3502
.sk_free_security = smack_sk_free_security,
3503
.sock_graft = smack_sock_graft,
3504
.inet_conn_request = smack_inet_conn_request,
3505
.inet_csk_clone = smack_inet_csk_clone,
3506
3507
/* key management security hooks */
3508
#ifdef CONFIG_KEYS
3509
.key_alloc = smack_key_alloc,
3510
.key_free = smack_key_free,
3511
.key_permission = smack_key_permission,
3512
#endif /* CONFIG_KEYS */
3513
3514
/* Audit hooks */
3515
#ifdef CONFIG_AUDIT
3516
.audit_rule_init = smack_audit_rule_init,
3517
.audit_rule_known = smack_audit_rule_known,
3518
.audit_rule_match = smack_audit_rule_match,
3519
.audit_rule_free = smack_audit_rule_free,
3520
#endif /* CONFIG_AUDIT */
3521
3522
.secid_to_secctx = smack_secid_to_secctx,
3523
.secctx_to_secid = smack_secctx_to_secid,
3524
.release_secctx = smack_release_secctx,
3525
.inode_notifysecctx = smack_inode_notifysecctx,
3526
.inode_setsecctx = smack_inode_setsecctx,
3527
.inode_getsecctx = smack_inode_getsecctx,
3528
};
3529
3530
3531
static __init void init_smack_know_list(void)
3532
{
3533
list_add(&smack_known_huh.list, &smack_known_list);
3534
list_add(&smack_known_hat.list, &smack_known_list);
3535
list_add(&smack_known_star.list, &smack_known_list);
3536
list_add(&smack_known_floor.list, &smack_known_list);
3537
list_add(&smack_known_invalid.list, &smack_known_list);
3538
list_add(&smack_known_web.list, &smack_known_list);
3539
}
3540
3541
/**
3542
* smack_init - initialize the smack system
3543
*
3544
* Returns 0
3545
*/
3546
static __init int smack_init(void)
3547
{
3548
struct cred *cred;
3549
struct task_smack *tsp;
3550
3551
if (!security_module_enable(&smack_ops))
3552
return 0;
3553
3554
tsp = new_task_smack(smack_known_floor.smk_known,
3555
smack_known_floor.smk_known, GFP_KERNEL);
3556
if (tsp == NULL)
3557
return -ENOMEM;
3558
3559
printk(KERN_INFO "Smack: Initializing.\n");
3560
3561
/*
3562
* Set the security state for the initial task.
3563
*/
3564
cred = (struct cred *) current->cred;
3565
cred->security = tsp;
3566
3567
/* initialize the smack_know_list */
3568
init_smack_know_list();
3569
/*
3570
* Initialize locks
3571
*/
3572
spin_lock_init(&smack_known_huh.smk_cipsolock);
3573
spin_lock_init(&smack_known_hat.smk_cipsolock);
3574
spin_lock_init(&smack_known_star.smk_cipsolock);
3575
spin_lock_init(&smack_known_floor.smk_cipsolock);
3576
spin_lock_init(&smack_known_invalid.smk_cipsolock);
3577
3578
/*
3579
* Register with LSM
3580
*/
3581
if (register_security(&smack_ops))
3582
panic("smack: Unable to register with kernel.\n");
3583
3584
return 0;
3585
}
3586
3587
/*
3588
* Smack requires early initialization in order to label
3589
* all processes and objects when they are created.
3590
*/
3591
security_initcall(smack_init);
3592
3593