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[PATCH] splice: fix problems with sys_tee()
[linux-2.6.22.y-op.git] / kernel / auditfilter.c
blob5b4e16276ca05a4bd91512762a6f2fc86e5509a1
1 /* auditfilter.c -- filtering of audit events
2 *
3 * Copyright 2003-2004 Red Hat, Inc.
4 * Copyright 2005 Hewlett-Packard Development Company, L.P.
5 * Copyright 2005 IBM Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/audit.h>
24 #include <linux/kthread.h>
25 #include <linux/mutex.h>
26 #include <linux/fs.h>
27 #include <linux/namei.h>
28 #include <linux/netlink.h>
29 #include <linux/sched.h>
30 #include <linux/inotify.h>
31 #include <linux/selinux.h>
32 #include "audit.h"
33
34 /*
35 * Locking model:
36 *
37 * audit_filter_mutex:
38 * Synchronizes writes and blocking reads of audit's filterlist
39 * data. Rcu is used to traverse the filterlist and access
40 * contents of structs audit_entry, audit_watch and opaque
41 * selinux rules during filtering. If modified, these structures
42 * must be copied and replace their counterparts in the filterlist.
43 * An audit_parent struct is not accessed during filtering, so may
44 * be written directly provided audit_filter_mutex is held.
45 */
46
47 /*
48 * Reference counting:
49 *
50 * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
51 * event. Each audit_watch holds a reference to its associated parent.
52 *
53 * audit_watch: if added to lists, lifetime is from audit_init_watch() to
54 * audit_remove_watch(). Additionally, an audit_watch may exist
55 * temporarily to assist in searching existing filter data. Each
56 * audit_krule holds a reference to its associated watch.
57 */
58
59 struct audit_parent {
60 struct list_head ilist; /* entry in inotify registration list */
61 struct list_head watches; /* associated watches */
62 struct inotify_watch wdata; /* inotify watch data */
63 unsigned flags; /* status flags */
64 };
65
66 /*
67 * audit_parent status flags:
68 *
69 * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
70 * a filesystem event to ensure we're adding audit watches to a valid parent.
71 * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
72 * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
73 * we can receive while holding nameidata.
74 */
75 #define AUDIT_PARENT_INVALID 0x001
76
77 /* Audit filter lists, defined in <linux/audit.h> */
78 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
79 LIST_HEAD_INIT(audit_filter_list[0]),
80 LIST_HEAD_INIT(audit_filter_list[1]),
81 LIST_HEAD_INIT(audit_filter_list[2]),
82 LIST_HEAD_INIT(audit_filter_list[3]),
83 LIST_HEAD_INIT(audit_filter_list[4]),
84 LIST_HEAD_INIT(audit_filter_list[5]),
85 #if AUDIT_NR_FILTERS != 6
86 #error Fix audit_filter_list initialiser
87 #endif
88 };
89
90 static DEFINE_MUTEX(audit_filter_mutex);
91
92 /* Inotify handle */
93 extern struct inotify_handle *audit_ih;
94
95 /* Inotify events we care about. */
96 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
97
98 void audit_free_parent(struct inotify_watch *i_watch)
99 {
100 struct audit_parent *parent;
101
102 parent = container_of(i_watch, struct audit_parent, wdata);
103 WARN_ON(!list_empty(&parent->watches));
104 kfree(parent);
105 }
106
107 static inline void audit_get_watch(struct audit_watch *watch)
108 {
109 atomic_inc(&watch->count);
110 }
111
112 static void audit_put_watch(struct audit_watch *watch)
113 {
114 if (atomic_dec_and_test(&watch->count)) {
115 WARN_ON(watch->parent);
116 WARN_ON(!list_empty(&watch->rules));
117 kfree(watch->path);
118 kfree(watch);
119 }
120 }
121
122 static void audit_remove_watch(struct audit_watch *watch)
123 {
124 list_del(&watch->wlist);
125 put_inotify_watch(&watch->parent->wdata);
126 watch->parent = NULL;
127 audit_put_watch(watch); /* match initial get */
128 }
129
130 static inline void audit_free_rule(struct audit_entry *e)
131 {
132 int i;
133
134 /* some rules don't have associated watches */
135 if (e->rule.watch)
136 audit_put_watch(e->rule.watch);
137 if (e->rule.fields)
138 for (i = 0; i < e->rule.field_count; i++) {
139 struct audit_field *f = &e->rule.fields[i];
140 kfree(f->se_str);
141 selinux_audit_rule_free(f->se_rule);
142 }
143 kfree(e->rule.fields);
144 kfree(e->rule.filterkey);
145 kfree(e);
146 }
147
148 static inline void audit_free_rule_rcu(struct rcu_head *head)
149 {
150 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
151 audit_free_rule(e);
152 }
153
154 /* Initialize a parent watch entry. */
155 static struct audit_parent *audit_init_parent(struct nameidata *ndp)
156 {
157 struct audit_parent *parent;
158 s32 wd;
159
160 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
161 if (unlikely(!parent))
162 return ERR_PTR(-ENOMEM);
163
164 INIT_LIST_HEAD(&parent->watches);
165 parent->flags = 0;
166
167 inotify_init_watch(&parent->wdata);
168 /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
169 get_inotify_watch(&parent->wdata);
170 wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode,
171 AUDIT_IN_WATCH);
172 if (wd < 0) {
173 audit_free_parent(&parent->wdata);
174 return ERR_PTR(wd);
175 }
176
177 return parent;
178 }
179
180 /* Initialize a watch entry. */
181 static struct audit_watch *audit_init_watch(char *path)
182 {
183 struct audit_watch *watch;
184
185 watch = kzalloc(sizeof(*watch), GFP_KERNEL);
186 if (unlikely(!watch))
187 return ERR_PTR(-ENOMEM);
188
189 INIT_LIST_HEAD(&watch->rules);
190 atomic_set(&watch->count, 1);
191 watch->path = path;
192 watch->dev = (dev_t)-1;
193 watch->ino = (unsigned long)-1;
194
195 return watch;
196 }
197
198 /* Initialize an audit filterlist entry. */
199 static inline struct audit_entry *audit_init_entry(u32 field_count)
200 {
201 struct audit_entry *entry;
202 struct audit_field *fields;
203
204 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
205 if (unlikely(!entry))
206 return NULL;
207
208 fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
209 if (unlikely(!fields)) {
210 kfree(entry);
211 return NULL;
212 }
213 entry->rule.fields = fields;
214
215 return entry;
216 }
217
218 /* Unpack a filter field's string representation from user-space
219 * buffer. */
220 static char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
221 {
222 char *str;
223
224 if (!*bufp || (len == 0) || (len > *remain))
225 return ERR_PTR(-EINVAL);
226
227 /* Of the currently implemented string fields, PATH_MAX
228 * defines the longest valid length.
229 */
230 if (len > PATH_MAX)
231 return ERR_PTR(-ENAMETOOLONG);
232
233 str = kmalloc(len + 1, GFP_KERNEL);
234 if (unlikely(!str))
235 return ERR_PTR(-ENOMEM);
236
237 memcpy(str, *bufp, len);
238 str[len] = 0;
239 *bufp += len;
240 *remain -= len;
241
242 return str;
243 }
244
245 /* Translate an inode field to kernel respresentation. */
246 static inline int audit_to_inode(struct audit_krule *krule,
247 struct audit_field *f)
248 {
249 if (krule->listnr != AUDIT_FILTER_EXIT ||
250 krule->watch || krule->inode_f)
251 return -EINVAL;
252
253 krule->inode_f = f;
254 return 0;
255 }
256
257 /* Translate a watch string to kernel respresentation. */
258 static int audit_to_watch(struct audit_krule *krule, char *path, int len,
259 u32 op)
260 {
261 struct audit_watch *watch;
262
263 if (!audit_ih)
264 return -EOPNOTSUPP;
265
266 if (path[0] != '/' || path[len-1] == '/' ||
267 krule->listnr != AUDIT_FILTER_EXIT ||
268 op & ~AUDIT_EQUAL ||
269 krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */
270 return -EINVAL;
271
272 watch = audit_init_watch(path);
273 if (unlikely(IS_ERR(watch)))
274 return PTR_ERR(watch);
275
276 audit_get_watch(watch);
277 krule->watch = watch;
278
279 return 0;
280 }
281
282 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
283
284 int __init audit_register_class(int class, unsigned *list)
285 {
286 __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
287 if (!p)
288 return -ENOMEM;
289 while (*list != ~0U) {
290 unsigned n = *list++;
291 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
292 kfree(p);
293 return -EINVAL;
294 }
295 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
296 }
297 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
298 kfree(p);
299 return -EINVAL;
300 }
301 classes[class] = p;
302 return 0;
303 }
304
305 /* Common user-space to kernel rule translation. */
306 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
307 {
308 unsigned listnr;
309 struct audit_entry *entry;
310 int i, err;
311
312 err = -EINVAL;
313 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
314 switch(listnr) {
315 default:
316 goto exit_err;
317 case AUDIT_FILTER_USER:
318 case AUDIT_FILTER_TYPE:
319 #ifdef CONFIG_AUDITSYSCALL
320 case AUDIT_FILTER_ENTRY:
321 case AUDIT_FILTER_EXIT:
322 case AUDIT_FILTER_TASK:
323 #endif
324 ;
325 }
326 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
327 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
328 goto exit_err;
329 }
330 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
331 goto exit_err;
332 if (rule->field_count > AUDIT_MAX_FIELDS)
333 goto exit_err;
334
335 err = -ENOMEM;
336 entry = audit_init_entry(rule->field_count);
337 if (!entry)
338 goto exit_err;
339
340 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
341 entry->rule.listnr = listnr;
342 entry->rule.action = rule->action;
343 entry->rule.field_count = rule->field_count;
344
345 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
346 entry->rule.mask[i] = rule->mask[i];
347
348 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
349 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
350 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
351 __u32 *class;
352
353 if (!(*p & AUDIT_BIT(bit)))
354 continue;
355 *p &= ~AUDIT_BIT(bit);
356 class = classes[i];
357 if (class) {
358 int j;
359 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
360 entry->rule.mask[j] |= class[j];
361 }
362 }
363
364 return entry;
365
366 exit_err:
367 return ERR_PTR(err);
368 }
369
370 /* Translate struct audit_rule to kernel's rule respresentation.
371 * Exists for backward compatibility with userspace. */
372 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
373 {
374 struct audit_entry *entry;
375 struct audit_field *f;
376 int err = 0;
377 int i;
378
379 entry = audit_to_entry_common(rule);
380 if (IS_ERR(entry))
381 goto exit_nofree;
382
383 for (i = 0; i < rule->field_count; i++) {
384 struct audit_field *f = &entry->rule.fields[i];
385
386 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
387 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
388 f->val = rule->values[i];
389
390 err = -EINVAL;
391 switch(f->type) {
392 default:
393 goto exit_free;
394 case AUDIT_PID:
395 case AUDIT_UID:
396 case AUDIT_EUID:
397 case AUDIT_SUID:
398 case AUDIT_FSUID:
399 case AUDIT_GID:
400 case AUDIT_EGID:
401 case AUDIT_SGID:
402 case AUDIT_FSGID:
403 case AUDIT_LOGINUID:
404 case AUDIT_PERS:
405 case AUDIT_ARCH:
406 case AUDIT_MSGTYPE:
407 case AUDIT_DEVMAJOR:
408 case AUDIT_DEVMINOR:
409 case AUDIT_EXIT:
410 case AUDIT_SUCCESS:
411 case AUDIT_ARG0:
412 case AUDIT_ARG1:
413 case AUDIT_ARG2:
414 case AUDIT_ARG3:
415 break;
416 case AUDIT_INODE:
417 err = audit_to_inode(&entry->rule, f);
418 if (err)
419 goto exit_free;
420 break;
421 }
422
423 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
424
425 /* Support for legacy operators where
426 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
427 if (f->op & AUDIT_NEGATE)
428 f->op = AUDIT_NOT_EQUAL;
429 else if (!f->op)
430 f->op = AUDIT_EQUAL;
431 else if (f->op == AUDIT_OPERATORS) {
432 err = -EINVAL;
433 goto exit_free;
434 }
435 }
436
437 f = entry->rule.inode_f;
438 if (f) {
439 switch(f->op) {
440 case AUDIT_NOT_EQUAL:
441 entry->rule.inode_f = NULL;
442 case AUDIT_EQUAL:
443 break;
444 default:
445 goto exit_free;
446 }
447 }
448
449 exit_nofree:
450 return entry;
451
452 exit_free:
453 audit_free_rule(entry);
454 return ERR_PTR(err);
455 }
456
457 /* Translate struct audit_rule_data to kernel's rule respresentation. */
458 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
459 size_t datasz)
460 {
461 int err = 0;
462 struct audit_entry *entry;
463 struct audit_field *f;
464 void *bufp;
465 size_t remain = datasz - sizeof(struct audit_rule_data);
466 int i;
467 char *str;
468
469 entry = audit_to_entry_common((struct audit_rule *)data);
470 if (IS_ERR(entry))
471 goto exit_nofree;
472
473 bufp = data->buf;
474 entry->rule.vers_ops = 2;
475 for (i = 0; i < data->field_count; i++) {
476 struct audit_field *f = &entry->rule.fields[i];
477
478 err = -EINVAL;
479 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
480 data->fieldflags[i] & ~AUDIT_OPERATORS)
481 goto exit_free;
482
483 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
484 f->type = data->fields[i];
485 f->val = data->values[i];
486 f->se_str = NULL;
487 f->se_rule = NULL;
488 switch(f->type) {
489 case AUDIT_PID:
490 case AUDIT_UID:
491 case AUDIT_EUID:
492 case AUDIT_SUID:
493 case AUDIT_FSUID:
494 case AUDIT_GID:
495 case AUDIT_EGID:
496 case AUDIT_SGID:
497 case AUDIT_FSGID:
498 case AUDIT_LOGINUID:
499 case AUDIT_PERS:
500 case AUDIT_ARCH:
501 case AUDIT_MSGTYPE:
502 case AUDIT_PPID:
503 case AUDIT_DEVMAJOR:
504 case AUDIT_DEVMINOR:
505 case AUDIT_EXIT:
506 case AUDIT_SUCCESS:
507 case AUDIT_ARG0:
508 case AUDIT_ARG1:
509 case AUDIT_ARG2:
510 case AUDIT_ARG3:
511 break;
512 case AUDIT_SUBJ_USER:
513 case AUDIT_SUBJ_ROLE:
514 case AUDIT_SUBJ_TYPE:
515 case AUDIT_SUBJ_SEN:
516 case AUDIT_SUBJ_CLR:
517 case AUDIT_OBJ_USER:
518 case AUDIT_OBJ_ROLE:
519 case AUDIT_OBJ_TYPE:
520 case AUDIT_OBJ_LEV_LOW:
521 case AUDIT_OBJ_LEV_HIGH:
522 str = audit_unpack_string(&bufp, &remain, f->val);
523 if (IS_ERR(str))
524 goto exit_free;
525 entry->rule.buflen += f->val;
526
527 err = selinux_audit_rule_init(f->type, f->op, str,
528 &f->se_rule);
529 /* Keep currently invalid fields around in case they
530 * become valid after a policy reload. */
531 if (err == -EINVAL) {
532 printk(KERN_WARNING "audit rule for selinux "
533 "\'%s\' is invalid\n", str);
534 err = 0;
535 }
536 if (err) {
537 kfree(str);
538 goto exit_free;
539 } else
540 f->se_str = str;
541 break;
542 case AUDIT_WATCH:
543 str = audit_unpack_string(&bufp, &remain, f->val);
544 if (IS_ERR(str))
545 goto exit_free;
546 entry->rule.buflen += f->val;
547
548 err = audit_to_watch(&entry->rule, str, f->val, f->op);
549 if (err) {
550 kfree(str);
551 goto exit_free;
552 }
553 break;
554 case AUDIT_INODE:
555 err = audit_to_inode(&entry->rule, f);
556 if (err)
557 goto exit_free;
558 break;
559 case AUDIT_FILTERKEY:
560 err = -EINVAL;
561 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
562 goto exit_free;
563 str = audit_unpack_string(&bufp, &remain, f->val);
564 if (IS_ERR(str))
565 goto exit_free;
566 entry->rule.buflen += f->val;
567 entry->rule.filterkey = str;
568 break;
569 default:
570 goto exit_free;
571 }
572 }
573
574 f = entry->rule.inode_f;
575 if (f) {
576 switch(f->op) {
577 case AUDIT_NOT_EQUAL:
578 entry->rule.inode_f = NULL;
579 case AUDIT_EQUAL:
580 break;
581 default:
582 goto exit_free;
583 }
584 }
585
586 exit_nofree:
587 return entry;
588
589 exit_free:
590 audit_free_rule(entry);
591 return ERR_PTR(err);
592 }
593
594 /* Pack a filter field's string representation into data block. */
595 static inline size_t audit_pack_string(void **bufp, char *str)
596 {
597 size_t len = strlen(str);
598
599 memcpy(*bufp, str, len);
600 *bufp += len;
601
602 return len;
603 }
604
605 /* Translate kernel rule respresentation to struct audit_rule.
606 * Exists for backward compatibility with userspace. */
607 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
608 {
609 struct audit_rule *rule;
610 int i;
611
612 rule = kmalloc(sizeof(*rule), GFP_KERNEL);
613 if (unlikely(!rule))
614 return NULL;
615 memset(rule, 0, sizeof(*rule));
616
617 rule->flags = krule->flags | krule->listnr;
618 rule->action = krule->action;
619 rule->field_count = krule->field_count;
620 for (i = 0; i < rule->field_count; i++) {
621 rule->values[i] = krule->fields[i].val;
622 rule->fields[i] = krule->fields[i].type;
623
624 if (krule->vers_ops == 1) {
625 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
626 rule->fields[i] |= AUDIT_NEGATE;
627 } else {
628 rule->fields[i] |= krule->fields[i].op;
629 }
630 }
631 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
632
633 return rule;
634 }
635
636 /* Translate kernel rule respresentation to struct audit_rule_data. */
637 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
638 {
639 struct audit_rule_data *data;
640 void *bufp;
641 int i;
642
643 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
644 if (unlikely(!data))
645 return NULL;
646 memset(data, 0, sizeof(*data));
647
648 data->flags = krule->flags | krule->listnr;
649 data->action = krule->action;
650 data->field_count = krule->field_count;
651 bufp = data->buf;
652 for (i = 0; i < data->field_count; i++) {
653 struct audit_field *f = &krule->fields[i];
654
655 data->fields[i] = f->type;
656 data->fieldflags[i] = f->op;
657 switch(f->type) {
658 case AUDIT_SUBJ_USER:
659 case AUDIT_SUBJ_ROLE:
660 case AUDIT_SUBJ_TYPE:
661 case AUDIT_SUBJ_SEN:
662 case AUDIT_SUBJ_CLR:
663 case AUDIT_OBJ_USER:
664 case AUDIT_OBJ_ROLE:
665 case AUDIT_OBJ_TYPE:
666 case AUDIT_OBJ_LEV_LOW:
667 case AUDIT_OBJ_LEV_HIGH:
668 data->buflen += data->values[i] =
669 audit_pack_string(&bufp, f->se_str);
670 break;
671 case AUDIT_WATCH:
672 data->buflen += data->values[i] =
673 audit_pack_string(&bufp, krule->watch->path);
674 break;
675 case AUDIT_FILTERKEY:
676 data->buflen += data->values[i] =
677 audit_pack_string(&bufp, krule->filterkey);
678 break;
679 default:
680 data->values[i] = f->val;
681 }
682 }
683 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
684
685 return data;
686 }
687
688 /* Compare two rules in kernel format. Considered success if rules
689 * don't match. */
690 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
691 {
692 int i;
693
694 if (a->flags != b->flags ||
695 a->listnr != b->listnr ||
696 a->action != b->action ||
697 a->field_count != b->field_count)
698 return 1;
699
700 for (i = 0; i < a->field_count; i++) {
701 if (a->fields[i].type != b->fields[i].type ||
702 a->fields[i].op != b->fields[i].op)
703 return 1;
704
705 switch(a->fields[i].type) {
706 case AUDIT_SUBJ_USER:
707 case AUDIT_SUBJ_ROLE:
708 case AUDIT_SUBJ_TYPE:
709 case AUDIT_SUBJ_SEN:
710 case AUDIT_SUBJ_CLR:
711 case AUDIT_OBJ_USER:
712 case AUDIT_OBJ_ROLE:
713 case AUDIT_OBJ_TYPE:
714 case AUDIT_OBJ_LEV_LOW:
715 case AUDIT_OBJ_LEV_HIGH:
716 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
717 return 1;
718 break;
719 case AUDIT_WATCH:
720 if (strcmp(a->watch->path, b->watch->path))
721 return 1;
722 break;
723 case AUDIT_FILTERKEY:
724 /* both filterkeys exist based on above type compare */
725 if (strcmp(a->filterkey, b->filterkey))
726 return 1;
727 break;
728 default:
729 if (a->fields[i].val != b->fields[i].val)
730 return 1;
731 }
732 }
733
734 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
735 if (a->mask[i] != b->mask[i])
736 return 1;
737
738 return 0;
739 }
740
741 /* Duplicate the given audit watch. The new watch's rules list is initialized
742 * to an empty list and wlist is undefined. */
743 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
744 {
745 char *path;
746 struct audit_watch *new;
747
748 path = kstrdup(old->path, GFP_KERNEL);
749 if (unlikely(!path))
750 return ERR_PTR(-ENOMEM);
751
752 new = audit_init_watch(path);
753 if (unlikely(IS_ERR(new))) {
754 kfree(path);
755 goto out;
756 }
757
758 new->dev = old->dev;
759 new->ino = old->ino;
760 get_inotify_watch(&old->parent->wdata);
761 new->parent = old->parent;
762
763 out:
764 return new;
765 }
766
767 /* Duplicate selinux field information. The se_rule is opaque, so must be
768 * re-initialized. */
769 static inline int audit_dupe_selinux_field(struct audit_field *df,
770 struct audit_field *sf)
771 {
772 int ret = 0;
773 char *se_str;
774
775 /* our own copy of se_str */
776 se_str = kstrdup(sf->se_str, GFP_KERNEL);
777 if (unlikely(IS_ERR(se_str)))
778 return -ENOMEM;
779 df->se_str = se_str;
780
781 /* our own (refreshed) copy of se_rule */
782 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
783 &df->se_rule);
784 /* Keep currently invalid fields around in case they
785 * become valid after a policy reload. */
786 if (ret == -EINVAL) {
787 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
788 "invalid\n", df->se_str);
789 ret = 0;
790 }
791
792 return ret;
793 }
794
795 /* Duplicate an audit rule. This will be a deep copy with the exception
796 * of the watch - that pointer is carried over. The selinux specific fields
797 * will be updated in the copy. The point is to be able to replace the old
798 * rule with the new rule in the filterlist, then free the old rule.
799 * The rlist element is undefined; list manipulations are handled apart from
800 * the initial copy. */
801 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
802 struct audit_watch *watch)
803 {
804 u32 fcount = old->field_count;
805 struct audit_entry *entry;
806 struct audit_krule *new;
807 char *fk;
808 int i, err = 0;
809
810 entry = audit_init_entry(fcount);
811 if (unlikely(!entry))
812 return ERR_PTR(-ENOMEM);
813
814 new = &entry->rule;
815 new->vers_ops = old->vers_ops;
816 new->flags = old->flags;
817 new->listnr = old->listnr;
818 new->action = old->action;
819 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
820 new->mask[i] = old->mask[i];
821 new->buflen = old->buflen;
822 new->inode_f = old->inode_f;
823 new->watch = NULL;
824 new->field_count = old->field_count;
825 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
826
827 /* deep copy this information, updating the se_rule fields, because
828 * the originals will all be freed when the old rule is freed. */
829 for (i = 0; i < fcount; i++) {
830 switch (new->fields[i].type) {
831 case AUDIT_SUBJ_USER:
832 case AUDIT_SUBJ_ROLE:
833 case AUDIT_SUBJ_TYPE:
834 case AUDIT_SUBJ_SEN:
835 case AUDIT_SUBJ_CLR:
836 case AUDIT_OBJ_USER:
837 case AUDIT_OBJ_ROLE:
838 case AUDIT_OBJ_TYPE:
839 case AUDIT_OBJ_LEV_LOW:
840 case AUDIT_OBJ_LEV_HIGH:
841 err = audit_dupe_selinux_field(&new->fields[i],
842 &old->fields[i]);
843 break;
844 case AUDIT_FILTERKEY:
845 fk = kstrdup(old->filterkey, GFP_KERNEL);
846 if (unlikely(!fk))
847 err = -ENOMEM;
848 else
849 new->filterkey = fk;
850 }
851 if (err) {
852 audit_free_rule(entry);
853 return ERR_PTR(err);
854 }
855 }
856
857 if (watch) {
858 audit_get_watch(watch);
859 new->watch = watch;
860 }
861
862 return entry;
863 }
864
865 /* Update inode info in audit rules based on filesystem event. */
866 static void audit_update_watch(struct audit_parent *parent,
867 const char *dname, dev_t dev,
868 unsigned long ino, unsigned invalidating)
869 {
870 struct audit_watch *owatch, *nwatch, *nextw;
871 struct audit_krule *r, *nextr;
872 struct audit_entry *oentry, *nentry;
873 struct audit_buffer *ab;
874
875 mutex_lock(&audit_filter_mutex);
876 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
877 if (audit_compare_dname_path(dname, owatch->path, NULL))
878 continue;
879
880 /* If the update involves invalidating rules, do the inode-based
881 * filtering now, so we don't omit records. */
882 if (invalidating &&
883 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
884 audit_set_auditable(current->audit_context);
885
886 nwatch = audit_dupe_watch(owatch);
887 if (unlikely(IS_ERR(nwatch))) {
888 mutex_unlock(&audit_filter_mutex);
889 audit_panic("error updating watch, skipping");
890 return;
891 }
892 nwatch->dev = dev;
893 nwatch->ino = ino;
894
895 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
896
897 oentry = container_of(r, struct audit_entry, rule);
898 list_del(&oentry->rule.rlist);
899 list_del_rcu(&oentry->list);
900
901 nentry = audit_dupe_rule(&oentry->rule, nwatch);
902 if (unlikely(IS_ERR(nentry)))
903 audit_panic("error updating watch, removing");
904 else {
905 int h = audit_hash_ino((u32)ino);
906 list_add(&nentry->rule.rlist, &nwatch->rules);
907 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
908 }
909
910 call_rcu(&oentry->rcu, audit_free_rule_rcu);
911 }
912
913 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
914 audit_log_format(ab, "audit updated rules specifying watch=");
915 audit_log_untrustedstring(ab, owatch->path);
916 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
917 audit_log_end(ab);
918
919 audit_remove_watch(owatch);
920 goto add_watch_to_parent; /* event applies to a single watch */
921 }
922 mutex_unlock(&audit_filter_mutex);
923 return;
924
925 add_watch_to_parent:
926 list_add(&nwatch->wlist, &parent->watches);
927 mutex_unlock(&audit_filter_mutex);
928 return;
929 }
930
931 /* Remove all watches & rules associated with a parent that is going away. */
932 static void audit_remove_parent_watches(struct audit_parent *parent)
933 {
934 struct audit_watch *w, *nextw;
935 struct audit_krule *r, *nextr;
936 struct audit_entry *e;
937
938 mutex_lock(&audit_filter_mutex);
939 parent->flags |= AUDIT_PARENT_INVALID;
940 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
941 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
942 e = container_of(r, struct audit_entry, rule);
943 list_del(&r->rlist);
944 list_del_rcu(&e->list);
945 call_rcu(&e->rcu, audit_free_rule_rcu);
946
947 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
948 "audit implicitly removed rule from list=%d\n",
949 AUDIT_FILTER_EXIT);
950 }
951 audit_remove_watch(w);
952 }
953 mutex_unlock(&audit_filter_mutex);
954 }
955
956 /* Unregister inotify watches for parents on in_list.
957 * Generates an IN_IGNORED event. */
958 static void audit_inotify_unregister(struct list_head *in_list)
959 {
960 struct audit_parent *p, *n;
961
962 list_for_each_entry_safe(p, n, in_list, ilist) {
963 list_del(&p->ilist);
964 inotify_rm_watch(audit_ih, &p->wdata);
965 /* the put matching the get in audit_do_del_rule() */
966 put_inotify_watch(&p->wdata);
967 }
968 }
969
970 /* Find an existing audit rule.
971 * Caller must hold audit_filter_mutex to prevent stale rule data. */
972 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
973 struct list_head *list)
974 {
975 struct audit_entry *e, *found = NULL;
976 int h;
977
978 if (entry->rule.watch) {
979 /* we don't know the inode number, so must walk entire hash */
980 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
981 list = &audit_inode_hash[h];
982 list_for_each_entry(e, list, list)
983 if (!audit_compare_rule(&entry->rule, &e->rule)) {
984 found = e;
985 goto out;
986 }
987 }
988 goto out;
989 }
990
991 list_for_each_entry(e, list, list)
992 if (!audit_compare_rule(&entry->rule, &e->rule)) {
993 found = e;
994 goto out;
995 }
996
997 out:
998 return found;
999 }
1000
1001 /* Get path information necessary for adding watches. */
1002 static int audit_get_nd(char *path, struct nameidata **ndp,
1003 struct nameidata **ndw)
1004 {
1005 struct nameidata *ndparent, *ndwatch;
1006 int err;
1007
1008 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1009 if (unlikely(!ndparent))
1010 return -ENOMEM;
1011
1012 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1013 if (unlikely(!ndwatch)) {
1014 kfree(ndparent);
1015 return -ENOMEM;
1016 }
1017
1018 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1019 if (err) {
1020 kfree(ndparent);
1021 kfree(ndwatch);
1022 return err;
1023 }
1024
1025 err = path_lookup(path, 0, ndwatch);
1026 if (err) {
1027 kfree(ndwatch);
1028 ndwatch = NULL;
1029 }
1030
1031 *ndp = ndparent;
1032 *ndw = ndwatch;
1033
1034 return 0;
1035 }
1036
1037 /* Release resources used for watch path information. */
1038 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1039 {
1040 if (ndp) {
1041 path_release(ndp);
1042 kfree(ndp);
1043 }
1044 if (ndw) {
1045 path_release(ndw);
1046 kfree(ndw);
1047 }
1048 }
1049
1050 /* Associate the given rule with an existing parent inotify_watch.
1051 * Caller must hold audit_filter_mutex. */
1052 static void audit_add_to_parent(struct audit_krule *krule,
1053 struct audit_parent *parent)
1054 {
1055 struct audit_watch *w, *watch = krule->watch;
1056 int watch_found = 0;
1057
1058 list_for_each_entry(w, &parent->watches, wlist) {
1059 if (strcmp(watch->path, w->path))
1060 continue;
1061
1062 watch_found = 1;
1063
1064 /* put krule's and initial refs to temporary watch */
1065 audit_put_watch(watch);
1066 audit_put_watch(watch);
1067
1068 audit_get_watch(w);
1069 krule->watch = watch = w;
1070 break;
1071 }
1072
1073 if (!watch_found) {
1074 get_inotify_watch(&parent->wdata);
1075 watch->parent = parent;
1076
1077 list_add(&watch->wlist, &parent->watches);
1078 }
1079 list_add(&krule->rlist, &watch->rules);
1080 }
1081
1082 /* Find a matching watch entry, or add this one.
1083 * Caller must hold audit_filter_mutex. */
1084 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1085 struct nameidata *ndw)
1086 {
1087 struct audit_watch *watch = krule->watch;
1088 struct inotify_watch *i_watch;
1089 struct audit_parent *parent;
1090 int ret = 0;
1091
1092 /* update watch filter fields */
1093 if (ndw) {
1094 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1095 watch->ino = ndw->dentry->d_inode->i_ino;
1096 }
1097
1098 /* The audit_filter_mutex must not be held during inotify calls because
1099 * we hold it during inotify event callback processing. If an existing
1100 * inotify watch is found, inotify_find_watch() grabs a reference before
1101 * returning.
1102 */
1103 mutex_unlock(&audit_filter_mutex);
1104
1105 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1106 parent = audit_init_parent(ndp);
1107 if (IS_ERR(parent)) {
1108 /* caller expects mutex locked */
1109 mutex_lock(&audit_filter_mutex);
1110 return PTR_ERR(parent);
1111 }
1112 } else
1113 parent = container_of(i_watch, struct audit_parent, wdata);
1114
1115 mutex_lock(&audit_filter_mutex);
1116
1117 /* parent was moved before we took audit_filter_mutex */
1118 if (parent->flags & AUDIT_PARENT_INVALID)
1119 ret = -ENOENT;
1120 else
1121 audit_add_to_parent(krule, parent);
1122
1123 /* match get in audit_init_parent or inotify_find_watch */
1124 put_inotify_watch(&parent->wdata);
1125 return ret;
1126 }
1127
1128 /* Add rule to given filterlist if not a duplicate. */
1129 static inline int audit_add_rule(struct audit_entry *entry,
1130 struct list_head *list)
1131 {
1132 struct audit_entry *e;
1133 struct audit_field *inode_f = entry->rule.inode_f;
1134 struct audit_watch *watch = entry->rule.watch;
1135 struct nameidata *ndp, *ndw;
1136 int h, err, putnd_needed = 0;
1137
1138 if (inode_f) {
1139 h = audit_hash_ino(inode_f->val);
1140 list = &audit_inode_hash[h];
1141 }
1142
1143 mutex_lock(&audit_filter_mutex);
1144 e = audit_find_rule(entry, list);
1145 mutex_unlock(&audit_filter_mutex);
1146 if (e) {
1147 err = -EEXIST;
1148 goto error;
1149 }
1150
1151 /* Avoid calling path_lookup under audit_filter_mutex. */
1152 if (watch) {
1153 err = audit_get_nd(watch->path, &ndp, &ndw);
1154 if (err)
1155 goto error;
1156 putnd_needed = 1;
1157 }
1158
1159 mutex_lock(&audit_filter_mutex);
1160 if (watch) {
1161 /* audit_filter_mutex is dropped and re-taken during this call */
1162 err = audit_add_watch(&entry->rule, ndp, ndw);
1163 if (err) {
1164 mutex_unlock(&audit_filter_mutex);
1165 goto error;
1166 }
1167 h = audit_hash_ino((u32)watch->ino);
1168 list = &audit_inode_hash[h];
1169 }
1170
1171 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1172 list_add_rcu(&entry->list, list);
1173 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1174 } else {
1175 list_add_tail_rcu(&entry->list, list);
1176 }
1177 mutex_unlock(&audit_filter_mutex);
1178
1179 if (putnd_needed)
1180 audit_put_nd(ndp, ndw);
1181
1182 return 0;
1183
1184 error:
1185 if (putnd_needed)
1186 audit_put_nd(ndp, ndw);
1187 if (watch)
1188 audit_put_watch(watch); /* tmp watch, matches initial get */
1189 return err;
1190 }
1191
1192 /* Remove an existing rule from filterlist. */
1193 static inline int audit_del_rule(struct audit_entry *entry,
1194 struct list_head *list)
1195 {
1196 struct audit_entry *e;
1197 struct audit_field *inode_f = entry->rule.inode_f;
1198 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1199 LIST_HEAD(inotify_list);
1200 int h, ret = 0;
1201
1202 if (inode_f) {
1203 h = audit_hash_ino(inode_f->val);
1204 list = &audit_inode_hash[h];
1205 }
1206
1207 mutex_lock(&audit_filter_mutex);
1208 e = audit_find_rule(entry, list);
1209 if (!e) {
1210 mutex_unlock(&audit_filter_mutex);
1211 ret = -ENOENT;
1212 goto out;
1213 }
1214
1215 watch = e->rule.watch;
1216 if (watch) {
1217 struct audit_parent *parent = watch->parent;
1218
1219 list_del(&e->rule.rlist);
1220
1221 if (list_empty(&watch->rules)) {
1222 audit_remove_watch(watch);
1223
1224 if (list_empty(&parent->watches)) {
1225 /* Put parent on the inotify un-registration
1226 * list. Grab a reference before releasing
1227 * audit_filter_mutex, to be released in
1228 * audit_inotify_unregister(). */
1229 list_add(&parent->ilist, &inotify_list);
1230 get_inotify_watch(&parent->wdata);
1231 }
1232 }
1233 }
1234
1235 list_del_rcu(&e->list);
1236 call_rcu(&e->rcu, audit_free_rule_rcu);
1237
1238 mutex_unlock(&audit_filter_mutex);
1239
1240 if (!list_empty(&inotify_list))
1241 audit_inotify_unregister(&inotify_list);
1242
1243 out:
1244 if (tmp_watch)
1245 audit_put_watch(tmp_watch); /* match initial get */
1246
1247 return ret;
1248 }
1249
1250 /* List rules using struct audit_rule. Exists for backward
1251 * compatibility with userspace. */
1252 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1253 {
1254 struct sk_buff *skb;
1255 struct audit_entry *entry;
1256 int i;
1257
1258 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1259 * iterator to sync with list writers. */
1260 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1261 list_for_each_entry(entry, &audit_filter_list[i], list) {
1262 struct audit_rule *rule;
1263
1264 rule = audit_krule_to_rule(&entry->rule);
1265 if (unlikely(!rule))
1266 break;
1267 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1268 rule, sizeof(*rule));
1269 if (skb)
1270 skb_queue_tail(q, skb);
1271 kfree(rule);
1272 }
1273 }
1274 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1275 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1276 struct audit_rule *rule;
1277
1278 rule = audit_krule_to_rule(&entry->rule);
1279 if (unlikely(!rule))
1280 break;
1281 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1282 rule, sizeof(*rule));
1283 if (skb)
1284 skb_queue_tail(q, skb);
1285 kfree(rule);
1286 }
1287 }
1288 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1289 if (skb)
1290 skb_queue_tail(q, skb);
1291 }
1292
1293 /* List rules using struct audit_rule_data. */
1294 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1295 {
1296 struct sk_buff *skb;
1297 struct audit_entry *e;
1298 int i;
1299
1300 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1301 * iterator to sync with list writers. */
1302 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1303 list_for_each_entry(e, &audit_filter_list[i], list) {
1304 struct audit_rule_data *data;
1305
1306 data = audit_krule_to_data(&e->rule);
1307 if (unlikely(!data))
1308 break;
1309 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1310 data, sizeof(*data) + data->buflen);
1311 if (skb)
1312 skb_queue_tail(q, skb);
1313 kfree(data);
1314 }
1315 }
1316 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1317 list_for_each_entry(e, &audit_inode_hash[i], list) {
1318 struct audit_rule_data *data;
1319
1320 data = audit_krule_to_data(&e->rule);
1321 if (unlikely(!data))
1322 break;
1323 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1324 data, sizeof(*data) + data->buflen);
1325 if (skb)
1326 skb_queue_tail(q, skb);
1327 kfree(data);
1328 }
1329 }
1330 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1331 if (skb)
1332 skb_queue_tail(q, skb);
1333 }
1334
1335 /* Log rule additions and removals */
1336 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1337 struct audit_krule *rule, int res)
1338 {
1339 struct audit_buffer *ab;
1340
1341 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1342 if (!ab)
1343 return;
1344 audit_log_format(ab, "auid=%u", loginuid);
1345 if (sid) {
1346 char *ctx = NULL;
1347 u32 len;
1348 if (selinux_ctxid_to_string(sid, &ctx, &len))
1349 audit_log_format(ab, " ssid=%u", sid);
1350 else
1351 audit_log_format(ab, " subj=%s", ctx);
1352 kfree(ctx);
1353 }
1354 audit_log_format(ab, " %s rule key=", action);
1355 if (rule->filterkey)
1356 audit_log_untrustedstring(ab, rule->filterkey);
1357 else
1358 audit_log_format(ab, "(null)");
1359 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1360 audit_log_end(ab);
1361 }
1362
1363 /**
1364 * audit_receive_filter - apply all rules to the specified message type
1365 * @type: audit message type
1366 * @pid: target pid for netlink audit messages
1367 * @uid: target uid for netlink audit messages
1368 * @seq: netlink audit message sequence (serial) number
1369 * @data: payload data
1370 * @datasz: size of payload data
1371 * @loginuid: loginuid of sender
1372 * @sid: SE Linux Security ID of sender
1373 */
1374 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1375 size_t datasz, uid_t loginuid, u32 sid)
1376 {
1377 struct task_struct *tsk;
1378 struct audit_netlink_list *dest;
1379 int err = 0;
1380 struct audit_entry *entry;
1381
1382 switch (type) {
1383 case AUDIT_LIST:
1384 case AUDIT_LIST_RULES:
1385 /* We can't just spew out the rules here because we might fill
1386 * the available socket buffer space and deadlock waiting for
1387 * auditctl to read from it... which isn't ever going to
1388 * happen if we're actually running in the context of auditctl
1389 * trying to _send_ the stuff */
1390
1391 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1392 if (!dest)
1393 return -ENOMEM;
1394 dest->pid = pid;
1395 skb_queue_head_init(&dest->q);
1396
1397 mutex_lock(&audit_filter_mutex);
1398 if (type == AUDIT_LIST)
1399 audit_list(pid, seq, &dest->q);
1400 else
1401 audit_list_rules(pid, seq, &dest->q);
1402 mutex_unlock(&audit_filter_mutex);
1403
1404 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1405 if (IS_ERR(tsk)) {
1406 skb_queue_purge(&dest->q);
1407 kfree(dest);
1408 err = PTR_ERR(tsk);
1409 }
1410 break;
1411 case AUDIT_ADD:
1412 case AUDIT_ADD_RULE:
1413 if (type == AUDIT_ADD)
1414 entry = audit_rule_to_entry(data);
1415 else
1416 entry = audit_data_to_entry(data, datasz);
1417 if (IS_ERR(entry))
1418 return PTR_ERR(entry);
1419
1420 err = audit_add_rule(entry,
1421 &audit_filter_list[entry->rule.listnr]);
1422 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1423
1424 if (err)
1425 audit_free_rule(entry);
1426 break;
1427 case AUDIT_DEL:
1428 case AUDIT_DEL_RULE:
1429 if (type == AUDIT_DEL)
1430 entry = audit_rule_to_entry(data);
1431 else
1432 entry = audit_data_to_entry(data, datasz);
1433 if (IS_ERR(entry))
1434 return PTR_ERR(entry);
1435
1436 err = audit_del_rule(entry,
1437 &audit_filter_list[entry->rule.listnr]);
1438 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1439 !err);
1440
1441 audit_free_rule(entry);
1442 break;
1443 default:
1444 return -EINVAL;
1445 }
1446
1447 return err;
1448 }
1449
1450 int audit_comparator(const u32 left, const u32 op, const u32 right)
1451 {
1452 switch (op) {
1453 case AUDIT_EQUAL:
1454 return (left == right);
1455 case AUDIT_NOT_EQUAL:
1456 return (left != right);
1457 case AUDIT_LESS_THAN:
1458 return (left < right);
1459 case AUDIT_LESS_THAN_OR_EQUAL:
1460 return (left <= right);
1461 case AUDIT_GREATER_THAN:
1462 return (left > right);
1463 case AUDIT_GREATER_THAN_OR_EQUAL:
1464 return (left >= right);
1465 }
1466 BUG();
1467 return 0;
1468 }
1469
1470 /* Compare given dentry name with last component in given path,
1471 * return of 0 indicates a match. */
1472 int audit_compare_dname_path(const char *dname, const char *path,
1473 int *dirlen)
1474 {
1475 int dlen, plen;
1476 const char *p;
1477
1478 if (!dname || !path)
1479 return 1;
1480
1481 dlen = strlen(dname);
1482 plen = strlen(path);
1483 if (plen < dlen)
1484 return 1;
1485
1486 /* disregard trailing slashes */
1487 p = path + plen - 1;
1488 while ((*p == '/') && (p > path))
1489 p--;
1490
1491 /* find last path component */
1492 p = p - dlen + 1;
1493 if (p < path)
1494 return 1;
1495 else if (p > path) {
1496 if (*--p != '/')
1497 return 1;
1498 else
1499 p++;
1500 }
1501
1502 /* return length of path's directory component */
1503 if (dirlen)
1504 *dirlen = p - path;
1505 return strncmp(p, dname, dlen);
1506 }
1507
1508 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1509 struct audit_krule *rule,
1510 enum audit_state *state)
1511 {
1512 int i;
1513
1514 for (i = 0; i < rule->field_count; i++) {
1515 struct audit_field *f = &rule->fields[i];
1516 int result = 0;
1517
1518 switch (f->type) {
1519 case AUDIT_PID:
1520 result = audit_comparator(cb->creds.pid, f->op, f->val);
1521 break;
1522 case AUDIT_UID:
1523 result = audit_comparator(cb->creds.uid, f->op, f->val);
1524 break;
1525 case AUDIT_GID:
1526 result = audit_comparator(cb->creds.gid, f->op, f->val);
1527 break;
1528 case AUDIT_LOGINUID:
1529 result = audit_comparator(cb->loginuid, f->op, f->val);
1530 break;
1531 }
1532
1533 if (!result)
1534 return 0;
1535 }
1536 switch (rule->action) {
1537 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1538 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1539 }
1540 return 1;
1541 }
1542
1543 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1544 {
1545 struct audit_entry *e;
1546 enum audit_state state;
1547 int ret = 1;
1548
1549 rcu_read_lock();
1550 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1551 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1552 if (state == AUDIT_DISABLED)
1553 ret = 0;
1554 break;
1555 }
1556 }
1557 rcu_read_unlock();
1558
1559 return ret; /* Audit by default */
1560 }
1561
1562 int audit_filter_type(int type)
1563 {
1564 struct audit_entry *e;
1565 int result = 0;
1566
1567 rcu_read_lock();
1568 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1569 goto unlock_and_return;
1570
1571 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1572 list) {
1573 int i;
1574 for (i = 0; i < e->rule.field_count; i++) {
1575 struct audit_field *f = &e->rule.fields[i];
1576 if (f->type == AUDIT_MSGTYPE) {
1577 result = audit_comparator(type, f->op, f->val);
1578 if (!result)
1579 break;
1580 }
1581 }
1582 if (result)
1583 goto unlock_and_return;
1584 }
1585 unlock_and_return:
1586 rcu_read_unlock();
1587 return result;
1588 }
1589
1590 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1591 are selinux fields specified in the rule, 0 otherwise. */
1592 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1593 {
1594 int i;
1595
1596 for (i = 0; i < rule->field_count; i++) {
1597 struct audit_field *f = &rule->fields[i];
1598 switch (f->type) {
1599 case AUDIT_SUBJ_USER:
1600 case AUDIT_SUBJ_ROLE:
1601 case AUDIT_SUBJ_TYPE:
1602 case AUDIT_SUBJ_SEN:
1603 case AUDIT_SUBJ_CLR:
1604 case AUDIT_OBJ_USER:
1605 case AUDIT_OBJ_ROLE:
1606 case AUDIT_OBJ_TYPE:
1607 case AUDIT_OBJ_LEV_LOW:
1608 case AUDIT_OBJ_LEV_HIGH:
1609 return 1;
1610 }
1611 }
1612
1613 return 0;
1614 }
1615
1616 /* This function will re-initialize the se_rule field of all applicable rules.
1617 * It will traverse the filter lists serarching for rules that contain selinux
1618 * specific filter fields. When such a rule is found, it is copied, the
1619 * selinux field is re-initialized, and the old rule is replaced with the
1620 * updated rule. */
1621 int selinux_audit_rule_update(void)
1622 {
1623 struct audit_entry *entry, *n, *nentry;
1624 struct audit_watch *watch;
1625 int i, err = 0;
1626
1627 /* audit_filter_mutex synchronizes the writers */
1628 mutex_lock(&audit_filter_mutex);
1629
1630 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1631 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1632 if (!audit_rule_has_selinux(&entry->rule))
1633 continue;
1634
1635 watch = entry->rule.watch;
1636 nentry = audit_dupe_rule(&entry->rule, watch);
1637 if (unlikely(IS_ERR(nentry))) {
1638 /* save the first error encountered for the
1639 * return value */
1640 if (!err)
1641 err = PTR_ERR(nentry);
1642 audit_panic("error updating selinux filters");
1643 if (watch)
1644 list_del(&entry->rule.rlist);
1645 list_del_rcu(&entry->list);
1646 } else {
1647 if (watch) {
1648 list_add(&nentry->rule.rlist,
1649 &watch->rules);
1650 list_del(&entry->rule.rlist);
1651 }
1652 list_replace_rcu(&entry->list, &nentry->list);
1653 }
1654 call_rcu(&entry->rcu, audit_free_rule_rcu);
1655 }
1656 }
1657
1658 mutex_unlock(&audit_filter_mutex);
1659
1660 return err;
1661 }
1662
1663 /* Update watch data in audit rules based on inotify events. */
1664 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1665 u32 cookie, const char *dname, struct inode *inode)
1666 {
1667 struct audit_parent *parent;
1668
1669 parent = container_of(i_watch, struct audit_parent, wdata);
1670
1671 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1672 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1673 inode->i_ino, 0);
1674 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1675 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1676 /* inotify automatically removes the watch and sends IN_IGNORED */
1677 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1678 audit_remove_parent_watches(parent);
1679 /* inotify does not remove the watch, so remove it manually */
1680 else if(mask & IN_MOVE_SELF) {
1681 audit_remove_parent_watches(parent);
1682 inotify_remove_watch_locked(audit_ih, i_watch);
1683 } else if (mask & IN_IGNORED)
1684 put_inotify_watch(i_watch);
1685 }
linux v2.6.22.y-op