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S390: user readable uninitialised kernel memory (CVE-2006-5174)
[linux/fpc-iii.git] / kernel / auditfilter.c
bloba44879b0c72ff422ec5ef25c7931bbbb7da7cc57
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 int audit_match_class(int class, unsigned syscall)
306 {
307 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * sizeof(__u32)))
308 return 0;
309 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
310 return 0;
311 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
312 }
313
314 /* Common user-space to kernel rule translation. */
315 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
316 {
317 unsigned listnr;
318 struct audit_entry *entry;
319 int i, err;
320
321 err = -EINVAL;
322 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
323 switch(listnr) {
324 default:
325 goto exit_err;
326 case AUDIT_FILTER_USER:
327 case AUDIT_FILTER_TYPE:
328 #ifdef CONFIG_AUDITSYSCALL
329 case AUDIT_FILTER_ENTRY:
330 case AUDIT_FILTER_EXIT:
331 case AUDIT_FILTER_TASK:
332 #endif
333 ;
334 }
335 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
336 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
337 goto exit_err;
338 }
339 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
340 goto exit_err;
341 if (rule->field_count > AUDIT_MAX_FIELDS)
342 goto exit_err;
343
344 err = -ENOMEM;
345 entry = audit_init_entry(rule->field_count);
346 if (!entry)
347 goto exit_err;
348
349 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
350 entry->rule.listnr = listnr;
351 entry->rule.action = rule->action;
352 entry->rule.field_count = rule->field_count;
353
354 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
355 entry->rule.mask[i] = rule->mask[i];
356
357 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
358 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
359 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
360 __u32 *class;
361
362 if (!(*p & AUDIT_BIT(bit)))
363 continue;
364 *p &= ~AUDIT_BIT(bit);
365 class = classes[i];
366 if (class) {
367 int j;
368 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
369 entry->rule.mask[j] |= class[j];
370 }
371 }
372
373 return entry;
374
375 exit_err:
376 return ERR_PTR(err);
377 }
378
379 /* Translate struct audit_rule to kernel's rule respresentation.
380 * Exists for backward compatibility with userspace. */
381 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
382 {
383 struct audit_entry *entry;
384 struct audit_field *f;
385 int err = 0;
386 int i;
387
388 entry = audit_to_entry_common(rule);
389 if (IS_ERR(entry))
390 goto exit_nofree;
391
392 for (i = 0; i < rule->field_count; i++) {
393 struct audit_field *f = &entry->rule.fields[i];
394
395 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
396 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
397 f->val = rule->values[i];
398
399 err = -EINVAL;
400 switch(f->type) {
401 default:
402 goto exit_free;
403 case AUDIT_PID:
404 case AUDIT_UID:
405 case AUDIT_EUID:
406 case AUDIT_SUID:
407 case AUDIT_FSUID:
408 case AUDIT_GID:
409 case AUDIT_EGID:
410 case AUDIT_SGID:
411 case AUDIT_FSGID:
412 case AUDIT_LOGINUID:
413 case AUDIT_PERS:
414 case AUDIT_ARCH:
415 case AUDIT_MSGTYPE:
416 case AUDIT_PPID:
417 case AUDIT_DEVMAJOR:
418 case AUDIT_DEVMINOR:
419 case AUDIT_EXIT:
420 case AUDIT_SUCCESS:
421 case AUDIT_ARG0:
422 case AUDIT_ARG1:
423 case AUDIT_ARG2:
424 case AUDIT_ARG3:
425 break;
426 case AUDIT_PERM:
427 if (f->val & ~15)
428 goto exit_free;
429 break;
430 case AUDIT_INODE:
431 err = audit_to_inode(&entry->rule, f);
432 if (err)
433 goto exit_free;
434 break;
435 }
436
437 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
438
439 /* Support for legacy operators where
440 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
441 if (f->op & AUDIT_NEGATE)
442 f->op = AUDIT_NOT_EQUAL;
443 else if (!f->op)
444 f->op = AUDIT_EQUAL;
445 else if (f->op == AUDIT_OPERATORS) {
446 err = -EINVAL;
447 goto exit_free;
448 }
449 }
450
451 f = entry->rule.inode_f;
452 if (f) {
453 switch(f->op) {
454 case AUDIT_NOT_EQUAL:
455 entry->rule.inode_f = NULL;
456 case AUDIT_EQUAL:
457 break;
458 default:
459 err = -EINVAL;
460 goto exit_free;
461 }
462 }
463
464 exit_nofree:
465 return entry;
466
467 exit_free:
468 audit_free_rule(entry);
469 return ERR_PTR(err);
470 }
471
472 /* Translate struct audit_rule_data to kernel's rule respresentation. */
473 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
474 size_t datasz)
475 {
476 int err = 0;
477 struct audit_entry *entry;
478 struct audit_field *f;
479 void *bufp;
480 size_t remain = datasz - sizeof(struct audit_rule_data);
481 int i;
482 char *str;
483
484 entry = audit_to_entry_common((struct audit_rule *)data);
485 if (IS_ERR(entry))
486 goto exit_nofree;
487
488 bufp = data->buf;
489 entry->rule.vers_ops = 2;
490 for (i = 0; i < data->field_count; i++) {
491 struct audit_field *f = &entry->rule.fields[i];
492
493 err = -EINVAL;
494 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
495 data->fieldflags[i] & ~AUDIT_OPERATORS)
496 goto exit_free;
497
498 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
499 f->type = data->fields[i];
500 f->val = data->values[i];
501 f->se_str = NULL;
502 f->se_rule = NULL;
503 switch(f->type) {
504 case AUDIT_PID:
505 case AUDIT_UID:
506 case AUDIT_EUID:
507 case AUDIT_SUID:
508 case AUDIT_FSUID:
509 case AUDIT_GID:
510 case AUDIT_EGID:
511 case AUDIT_SGID:
512 case AUDIT_FSGID:
513 case AUDIT_LOGINUID:
514 case AUDIT_PERS:
515 case AUDIT_ARCH:
516 case AUDIT_MSGTYPE:
517 case AUDIT_PPID:
518 case AUDIT_DEVMAJOR:
519 case AUDIT_DEVMINOR:
520 case AUDIT_EXIT:
521 case AUDIT_SUCCESS:
522 case AUDIT_ARG0:
523 case AUDIT_ARG1:
524 case AUDIT_ARG2:
525 case AUDIT_ARG3:
526 break;
527 case AUDIT_SUBJ_USER:
528 case AUDIT_SUBJ_ROLE:
529 case AUDIT_SUBJ_TYPE:
530 case AUDIT_SUBJ_SEN:
531 case AUDIT_SUBJ_CLR:
532 case AUDIT_OBJ_USER:
533 case AUDIT_OBJ_ROLE:
534 case AUDIT_OBJ_TYPE:
535 case AUDIT_OBJ_LEV_LOW:
536 case AUDIT_OBJ_LEV_HIGH:
537 str = audit_unpack_string(&bufp, &remain, f->val);
538 if (IS_ERR(str))
539 goto exit_free;
540 entry->rule.buflen += f->val;
541
542 err = selinux_audit_rule_init(f->type, f->op, str,
543 &f->se_rule);
544 /* Keep currently invalid fields around in case they
545 * become valid after a policy reload. */
546 if (err == -EINVAL) {
547 printk(KERN_WARNING "audit rule for selinux "
548 "\'%s\' is invalid\n", str);
549 err = 0;
550 }
551 if (err) {
552 kfree(str);
553 goto exit_free;
554 } else
555 f->se_str = str;
556 break;
557 case AUDIT_WATCH:
558 str = audit_unpack_string(&bufp, &remain, f->val);
559 if (IS_ERR(str))
560 goto exit_free;
561 entry->rule.buflen += f->val;
562
563 err = audit_to_watch(&entry->rule, str, f->val, f->op);
564 if (err) {
565 kfree(str);
566 goto exit_free;
567 }
568 break;
569 case AUDIT_INODE:
570 err = audit_to_inode(&entry->rule, f);
571 if (err)
572 goto exit_free;
573 break;
574 case AUDIT_FILTERKEY:
575 err = -EINVAL;
576 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
577 goto exit_free;
578 str = audit_unpack_string(&bufp, &remain, f->val);
579 if (IS_ERR(str))
580 goto exit_free;
581 entry->rule.buflen += f->val;
582 entry->rule.filterkey = str;
583 break;
584 case AUDIT_PERM:
585 if (f->val & ~15)
586 goto exit_free;
587 break;
588 default:
589 goto exit_free;
590 }
591 }
592
593 f = entry->rule.inode_f;
594 if (f) {
595 switch(f->op) {
596 case AUDIT_NOT_EQUAL:
597 entry->rule.inode_f = NULL;
598 case AUDIT_EQUAL:
599 break;
600 default:
601 err = -EINVAL;
602 goto exit_free;
603 }
604 }
605
606 exit_nofree:
607 return entry;
608
609 exit_free:
610 audit_free_rule(entry);
611 return ERR_PTR(err);
612 }
613
614 /* Pack a filter field's string representation into data block. */
615 static inline size_t audit_pack_string(void **bufp, char *str)
616 {
617 size_t len = strlen(str);
618
619 memcpy(*bufp, str, len);
620 *bufp += len;
621
622 return len;
623 }
624
625 /* Translate kernel rule respresentation to struct audit_rule.
626 * Exists for backward compatibility with userspace. */
627 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
628 {
629 struct audit_rule *rule;
630 int i;
631
632 rule = kmalloc(sizeof(*rule), GFP_KERNEL);
633 if (unlikely(!rule))
634 return NULL;
635 memset(rule, 0, sizeof(*rule));
636
637 rule->flags = krule->flags | krule->listnr;
638 rule->action = krule->action;
639 rule->field_count = krule->field_count;
640 for (i = 0; i < rule->field_count; i++) {
641 rule->values[i] = krule->fields[i].val;
642 rule->fields[i] = krule->fields[i].type;
643
644 if (krule->vers_ops == 1) {
645 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
646 rule->fields[i] |= AUDIT_NEGATE;
647 } else {
648 rule->fields[i] |= krule->fields[i].op;
649 }
650 }
651 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
652
653 return rule;
654 }
655
656 /* Translate kernel rule respresentation to struct audit_rule_data. */
657 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
658 {
659 struct audit_rule_data *data;
660 void *bufp;
661 int i;
662
663 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
664 if (unlikely(!data))
665 return NULL;
666 memset(data, 0, sizeof(*data));
667
668 data->flags = krule->flags | krule->listnr;
669 data->action = krule->action;
670 data->field_count = krule->field_count;
671 bufp = data->buf;
672 for (i = 0; i < data->field_count; i++) {
673 struct audit_field *f = &krule->fields[i];
674
675 data->fields[i] = f->type;
676 data->fieldflags[i] = f->op;
677 switch(f->type) {
678 case AUDIT_SUBJ_USER:
679 case AUDIT_SUBJ_ROLE:
680 case AUDIT_SUBJ_TYPE:
681 case AUDIT_SUBJ_SEN:
682 case AUDIT_SUBJ_CLR:
683 case AUDIT_OBJ_USER:
684 case AUDIT_OBJ_ROLE:
685 case AUDIT_OBJ_TYPE:
686 case AUDIT_OBJ_LEV_LOW:
687 case AUDIT_OBJ_LEV_HIGH:
688 data->buflen += data->values[i] =
689 audit_pack_string(&bufp, f->se_str);
690 break;
691 case AUDIT_WATCH:
692 data->buflen += data->values[i] =
693 audit_pack_string(&bufp, krule->watch->path);
694 break;
695 case AUDIT_FILTERKEY:
696 data->buflen += data->values[i] =
697 audit_pack_string(&bufp, krule->filterkey);
698 break;
699 default:
700 data->values[i] = f->val;
701 }
702 }
703 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
704
705 return data;
706 }
707
708 /* Compare two rules in kernel format. Considered success if rules
709 * don't match. */
710 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
711 {
712 int i;
713
714 if (a->flags != b->flags ||
715 a->listnr != b->listnr ||
716 a->action != b->action ||
717 a->field_count != b->field_count)
718 return 1;
719
720 for (i = 0; i < a->field_count; i++) {
721 if (a->fields[i].type != b->fields[i].type ||
722 a->fields[i].op != b->fields[i].op)
723 return 1;
724
725 switch(a->fields[i].type) {
726 case AUDIT_SUBJ_USER:
727 case AUDIT_SUBJ_ROLE:
728 case AUDIT_SUBJ_TYPE:
729 case AUDIT_SUBJ_SEN:
730 case AUDIT_SUBJ_CLR:
731 case AUDIT_OBJ_USER:
732 case AUDIT_OBJ_ROLE:
733 case AUDIT_OBJ_TYPE:
734 case AUDIT_OBJ_LEV_LOW:
735 case AUDIT_OBJ_LEV_HIGH:
736 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
737 return 1;
738 break;
739 case AUDIT_WATCH:
740 if (strcmp(a->watch->path, b->watch->path))
741 return 1;
742 break;
743 case AUDIT_FILTERKEY:
744 /* both filterkeys exist based on above type compare */
745 if (strcmp(a->filterkey, b->filterkey))
746 return 1;
747 break;
748 default:
749 if (a->fields[i].val != b->fields[i].val)
750 return 1;
751 }
752 }
753
754 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
755 if (a->mask[i] != b->mask[i])
756 return 1;
757
758 return 0;
759 }
760
761 /* Duplicate the given audit watch. The new watch's rules list is initialized
762 * to an empty list and wlist is undefined. */
763 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
764 {
765 char *path;
766 struct audit_watch *new;
767
768 path = kstrdup(old->path, GFP_KERNEL);
769 if (unlikely(!path))
770 return ERR_PTR(-ENOMEM);
771
772 new = audit_init_watch(path);
773 if (unlikely(IS_ERR(new))) {
774 kfree(path);
775 goto out;
776 }
777
778 new->dev = old->dev;
779 new->ino = old->ino;
780 get_inotify_watch(&old->parent->wdata);
781 new->parent = old->parent;
782
783 out:
784 return new;
785 }
786
787 /* Duplicate selinux field information. The se_rule is opaque, so must be
788 * re-initialized. */
789 static inline int audit_dupe_selinux_field(struct audit_field *df,
790 struct audit_field *sf)
791 {
792 int ret = 0;
793 char *se_str;
794
795 /* our own copy of se_str */
796 se_str = kstrdup(sf->se_str, GFP_KERNEL);
797 if (unlikely(IS_ERR(se_str)))
798 return -ENOMEM;
799 df->se_str = se_str;
800
801 /* our own (refreshed) copy of se_rule */
802 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
803 &df->se_rule);
804 /* Keep currently invalid fields around in case they
805 * become valid after a policy reload. */
806 if (ret == -EINVAL) {
807 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
808 "invalid\n", df->se_str);
809 ret = 0;
810 }
811
812 return ret;
813 }
814
815 /* Duplicate an audit rule. This will be a deep copy with the exception
816 * of the watch - that pointer is carried over. The selinux specific fields
817 * will be updated in the copy. The point is to be able to replace the old
818 * rule with the new rule in the filterlist, then free the old rule.
819 * The rlist element is undefined; list manipulations are handled apart from
820 * the initial copy. */
821 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
822 struct audit_watch *watch)
823 {
824 u32 fcount = old->field_count;
825 struct audit_entry *entry;
826 struct audit_krule *new;
827 char *fk;
828 int i, err = 0;
829
830 entry = audit_init_entry(fcount);
831 if (unlikely(!entry))
832 return ERR_PTR(-ENOMEM);
833
834 new = &entry->rule;
835 new->vers_ops = old->vers_ops;
836 new->flags = old->flags;
837 new->listnr = old->listnr;
838 new->action = old->action;
839 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
840 new->mask[i] = old->mask[i];
841 new->buflen = old->buflen;
842 new->inode_f = old->inode_f;
843 new->watch = NULL;
844 new->field_count = old->field_count;
845 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
846
847 /* deep copy this information, updating the se_rule fields, because
848 * the originals will all be freed when the old rule is freed. */
849 for (i = 0; i < fcount; i++) {
850 switch (new->fields[i].type) {
851 case AUDIT_SUBJ_USER:
852 case AUDIT_SUBJ_ROLE:
853 case AUDIT_SUBJ_TYPE:
854 case AUDIT_SUBJ_SEN:
855 case AUDIT_SUBJ_CLR:
856 case AUDIT_OBJ_USER:
857 case AUDIT_OBJ_ROLE:
858 case AUDIT_OBJ_TYPE:
859 case AUDIT_OBJ_LEV_LOW:
860 case AUDIT_OBJ_LEV_HIGH:
861 err = audit_dupe_selinux_field(&new->fields[i],
862 &old->fields[i]);
863 break;
864 case AUDIT_FILTERKEY:
865 fk = kstrdup(old->filterkey, GFP_KERNEL);
866 if (unlikely(!fk))
867 err = -ENOMEM;
868 else
869 new->filterkey = fk;
870 }
871 if (err) {
872 audit_free_rule(entry);
873 return ERR_PTR(err);
874 }
875 }
876
877 if (watch) {
878 audit_get_watch(watch);
879 new->watch = watch;
880 }
881
882 return entry;
883 }
884
885 /* Update inode info in audit rules based on filesystem event. */
886 static void audit_update_watch(struct audit_parent *parent,
887 const char *dname, dev_t dev,
888 unsigned long ino, unsigned invalidating)
889 {
890 struct audit_watch *owatch, *nwatch, *nextw;
891 struct audit_krule *r, *nextr;
892 struct audit_entry *oentry, *nentry;
893 struct audit_buffer *ab;
894
895 mutex_lock(&audit_filter_mutex);
896 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
897 if (audit_compare_dname_path(dname, owatch->path, NULL))
898 continue;
899
900 /* If the update involves invalidating rules, do the inode-based
901 * filtering now, so we don't omit records. */
902 if (invalidating &&
903 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
904 audit_set_auditable(current->audit_context);
905
906 nwatch = audit_dupe_watch(owatch);
907 if (unlikely(IS_ERR(nwatch))) {
908 mutex_unlock(&audit_filter_mutex);
909 audit_panic("error updating watch, skipping");
910 return;
911 }
912 nwatch->dev = dev;
913 nwatch->ino = ino;
914
915 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
916
917 oentry = container_of(r, struct audit_entry, rule);
918 list_del(&oentry->rule.rlist);
919 list_del_rcu(&oentry->list);
920
921 nentry = audit_dupe_rule(&oentry->rule, nwatch);
922 if (unlikely(IS_ERR(nentry)))
923 audit_panic("error updating watch, removing");
924 else {
925 int h = audit_hash_ino((u32)ino);
926 list_add(&nentry->rule.rlist, &nwatch->rules);
927 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
928 }
929
930 call_rcu(&oentry->rcu, audit_free_rule_rcu);
931 }
932
933 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
934 audit_log_format(ab, "audit updated rules specifying path=");
935 audit_log_untrustedstring(ab, owatch->path);
936 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
937 audit_log_end(ab);
938
939 audit_remove_watch(owatch);
940 goto add_watch_to_parent; /* event applies to a single watch */
941 }
942 mutex_unlock(&audit_filter_mutex);
943 return;
944
945 add_watch_to_parent:
946 list_add(&nwatch->wlist, &parent->watches);
947 mutex_unlock(&audit_filter_mutex);
948 return;
949 }
950
951 /* Remove all watches & rules associated with a parent that is going away. */
952 static void audit_remove_parent_watches(struct audit_parent *parent)
953 {
954 struct audit_watch *w, *nextw;
955 struct audit_krule *r, *nextr;
956 struct audit_entry *e;
957 struct audit_buffer *ab;
958
959 mutex_lock(&audit_filter_mutex);
960 parent->flags |= AUDIT_PARENT_INVALID;
961 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
962 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
963 e = container_of(r, struct audit_entry, rule);
964
965 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
966 audit_log_format(ab, "audit implicitly removed rule path=");
967 audit_log_untrustedstring(ab, w->path);
968 if (r->filterkey) {
969 audit_log_format(ab, " key=");
970 audit_log_untrustedstring(ab, r->filterkey);
971 } else
972 audit_log_format(ab, " key=(null)");
973 audit_log_format(ab, " list=%d", r->listnr);
974 audit_log_end(ab);
975
976 list_del(&r->rlist);
977 list_del_rcu(&e->list);
978 call_rcu(&e->rcu, audit_free_rule_rcu);
979 }
980 audit_remove_watch(w);
981 }
982 mutex_unlock(&audit_filter_mutex);
983 }
984
985 /* Unregister inotify watches for parents on in_list.
986 * Generates an IN_IGNORED event. */
987 static void audit_inotify_unregister(struct list_head *in_list)
988 {
989 struct audit_parent *p, *n;
990
991 list_for_each_entry_safe(p, n, in_list, ilist) {
992 list_del(&p->ilist);
993 inotify_rm_watch(audit_ih, &p->wdata);
994 /* the put matching the get in audit_do_del_rule() */
995 put_inotify_watch(&p->wdata);
996 }
997 }
998
999 /* Find an existing audit rule.
1000 * Caller must hold audit_filter_mutex to prevent stale rule data. */
1001 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
1002 struct list_head *list)
1003 {
1004 struct audit_entry *e, *found = NULL;
1005 int h;
1006
1007 if (entry->rule.watch) {
1008 /* we don't know the inode number, so must walk entire hash */
1009 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
1010 list = &audit_inode_hash[h];
1011 list_for_each_entry(e, list, list)
1012 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1013 found = e;
1014 goto out;
1015 }
1016 }
1017 goto out;
1018 }
1019
1020 list_for_each_entry(e, list, list)
1021 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1022 found = e;
1023 goto out;
1024 }
1025
1026 out:
1027 return found;
1028 }
1029
1030 /* Get path information necessary for adding watches. */
1031 static int audit_get_nd(char *path, struct nameidata **ndp,
1032 struct nameidata **ndw)
1033 {
1034 struct nameidata *ndparent, *ndwatch;
1035 int err;
1036
1037 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1038 if (unlikely(!ndparent))
1039 return -ENOMEM;
1040
1041 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1042 if (unlikely(!ndwatch)) {
1043 kfree(ndparent);
1044 return -ENOMEM;
1045 }
1046
1047 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1048 if (err) {
1049 kfree(ndparent);
1050 kfree(ndwatch);
1051 return err;
1052 }
1053
1054 err = path_lookup(path, 0, ndwatch);
1055 if (err) {
1056 kfree(ndwatch);
1057 ndwatch = NULL;
1058 }
1059
1060 *ndp = ndparent;
1061 *ndw = ndwatch;
1062
1063 return 0;
1064 }
1065
1066 /* Release resources used for watch path information. */
1067 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1068 {
1069 if (ndp) {
1070 path_release(ndp);
1071 kfree(ndp);
1072 }
1073 if (ndw) {
1074 path_release(ndw);
1075 kfree(ndw);
1076 }
1077 }
1078
1079 /* Associate the given rule with an existing parent inotify_watch.
1080 * Caller must hold audit_filter_mutex. */
1081 static void audit_add_to_parent(struct audit_krule *krule,
1082 struct audit_parent *parent)
1083 {
1084 struct audit_watch *w, *watch = krule->watch;
1085 int watch_found = 0;
1086
1087 list_for_each_entry(w, &parent->watches, wlist) {
1088 if (strcmp(watch->path, w->path))
1089 continue;
1090
1091 watch_found = 1;
1092
1093 /* put krule's and initial refs to temporary watch */
1094 audit_put_watch(watch);
1095 audit_put_watch(watch);
1096
1097 audit_get_watch(w);
1098 krule->watch = watch = w;
1099 break;
1100 }
1101
1102 if (!watch_found) {
1103 get_inotify_watch(&parent->wdata);
1104 watch->parent = parent;
1105
1106 list_add(&watch->wlist, &parent->watches);
1107 }
1108 list_add(&krule->rlist, &watch->rules);
1109 }
1110
1111 /* Find a matching watch entry, or add this one.
1112 * Caller must hold audit_filter_mutex. */
1113 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1114 struct nameidata *ndw)
1115 {
1116 struct audit_watch *watch = krule->watch;
1117 struct inotify_watch *i_watch;
1118 struct audit_parent *parent;
1119 int ret = 0;
1120
1121 /* update watch filter fields */
1122 if (ndw) {
1123 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1124 watch->ino = ndw->dentry->d_inode->i_ino;
1125 }
1126
1127 /* The audit_filter_mutex must not be held during inotify calls because
1128 * we hold it during inotify event callback processing. If an existing
1129 * inotify watch is found, inotify_find_watch() grabs a reference before
1130 * returning.
1131 */
1132 mutex_unlock(&audit_filter_mutex);
1133
1134 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1135 parent = audit_init_parent(ndp);
1136 if (IS_ERR(parent)) {
1137 /* caller expects mutex locked */
1138 mutex_lock(&audit_filter_mutex);
1139 return PTR_ERR(parent);
1140 }
1141 } else
1142 parent = container_of(i_watch, struct audit_parent, wdata);
1143
1144 mutex_lock(&audit_filter_mutex);
1145
1146 /* parent was moved before we took audit_filter_mutex */
1147 if (parent->flags & AUDIT_PARENT_INVALID)
1148 ret = -ENOENT;
1149 else
1150 audit_add_to_parent(krule, parent);
1151
1152 /* match get in audit_init_parent or inotify_find_watch */
1153 put_inotify_watch(&parent->wdata);
1154 return ret;
1155 }
1156
1157 /* Add rule to given filterlist if not a duplicate. */
1158 static inline int audit_add_rule(struct audit_entry *entry,
1159 struct list_head *list)
1160 {
1161 struct audit_entry *e;
1162 struct audit_field *inode_f = entry->rule.inode_f;
1163 struct audit_watch *watch = entry->rule.watch;
1164 struct nameidata *ndp, *ndw;
1165 int h, err, putnd_needed = 0;
1166 #ifdef CONFIG_AUDITSYSCALL
1167 int dont_count = 0;
1168
1169 /* If either of these, don't count towards total */
1170 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1171 entry->rule.listnr == AUDIT_FILTER_TYPE)
1172 dont_count = 1;
1173 #endif
1174
1175 if (inode_f) {
1176 h = audit_hash_ino(inode_f->val);
1177 list = &audit_inode_hash[h];
1178 }
1179
1180 mutex_lock(&audit_filter_mutex);
1181 e = audit_find_rule(entry, list);
1182 mutex_unlock(&audit_filter_mutex);
1183 if (e) {
1184 err = -EEXIST;
1185 goto error;
1186 }
1187
1188 /* Avoid calling path_lookup under audit_filter_mutex. */
1189 if (watch) {
1190 err = audit_get_nd(watch->path, &ndp, &ndw);
1191 if (err)
1192 goto error;
1193 putnd_needed = 1;
1194 }
1195
1196 mutex_lock(&audit_filter_mutex);
1197 if (watch) {
1198 /* audit_filter_mutex is dropped and re-taken during this call */
1199 err = audit_add_watch(&entry->rule, ndp, ndw);
1200 if (err) {
1201 mutex_unlock(&audit_filter_mutex);
1202 goto error;
1203 }
1204 h = audit_hash_ino((u32)watch->ino);
1205 list = &audit_inode_hash[h];
1206 }
1207
1208 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1209 list_add_rcu(&entry->list, list);
1210 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1211 } else {
1212 list_add_tail_rcu(&entry->list, list);
1213 }
1214 #ifdef CONFIG_AUDITSYSCALL
1215 if (!dont_count)
1216 audit_n_rules++;
1217 #endif
1218 mutex_unlock(&audit_filter_mutex);
1219
1220 if (putnd_needed)
1221 audit_put_nd(ndp, ndw);
1222
1223 return 0;
1224
1225 error:
1226 if (putnd_needed)
1227 audit_put_nd(ndp, ndw);
1228 if (watch)
1229 audit_put_watch(watch); /* tmp watch, matches initial get */
1230 return err;
1231 }
1232
1233 /* Remove an existing rule from filterlist. */
1234 static inline int audit_del_rule(struct audit_entry *entry,
1235 struct list_head *list)
1236 {
1237 struct audit_entry *e;
1238 struct audit_field *inode_f = entry->rule.inode_f;
1239 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1240 LIST_HEAD(inotify_list);
1241 int h, ret = 0;
1242 #ifdef CONFIG_AUDITSYSCALL
1243 int dont_count = 0;
1244
1245 /* If either of these, don't count towards total */
1246 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1247 entry->rule.listnr == AUDIT_FILTER_TYPE)
1248 dont_count = 1;
1249 #endif
1250
1251 if (inode_f) {
1252 h = audit_hash_ino(inode_f->val);
1253 list = &audit_inode_hash[h];
1254 }
1255
1256 mutex_lock(&audit_filter_mutex);
1257 e = audit_find_rule(entry, list);
1258 if (!e) {
1259 mutex_unlock(&audit_filter_mutex);
1260 ret = -ENOENT;
1261 goto out;
1262 }
1263
1264 watch = e->rule.watch;
1265 if (watch) {
1266 struct audit_parent *parent = watch->parent;
1267
1268 list_del(&e->rule.rlist);
1269
1270 if (list_empty(&watch->rules)) {
1271 audit_remove_watch(watch);
1272
1273 if (list_empty(&parent->watches)) {
1274 /* Put parent on the inotify un-registration
1275 * list. Grab a reference before releasing
1276 * audit_filter_mutex, to be released in
1277 * audit_inotify_unregister(). */
1278 list_add(&parent->ilist, &inotify_list);
1279 get_inotify_watch(&parent->wdata);
1280 }
1281 }
1282 }
1283
1284 list_del_rcu(&e->list);
1285 call_rcu(&e->rcu, audit_free_rule_rcu);
1286
1287 #ifdef CONFIG_AUDITSYSCALL
1288 if (!dont_count)
1289 audit_n_rules--;
1290 #endif
1291 mutex_unlock(&audit_filter_mutex);
1292
1293 if (!list_empty(&inotify_list))
1294 audit_inotify_unregister(&inotify_list);
1295
1296 out:
1297 if (tmp_watch)
1298 audit_put_watch(tmp_watch); /* match initial get */
1299
1300 return ret;
1301 }
1302
1303 /* List rules using struct audit_rule. Exists for backward
1304 * compatibility with userspace. */
1305 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1306 {
1307 struct sk_buff *skb;
1308 struct audit_entry *entry;
1309 int i;
1310
1311 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1312 * iterator to sync with list writers. */
1313 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1314 list_for_each_entry(entry, &audit_filter_list[i], list) {
1315 struct audit_rule *rule;
1316
1317 rule = audit_krule_to_rule(&entry->rule);
1318 if (unlikely(!rule))
1319 break;
1320 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1321 rule, sizeof(*rule));
1322 if (skb)
1323 skb_queue_tail(q, skb);
1324 kfree(rule);
1325 }
1326 }
1327 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1328 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1329 struct audit_rule *rule;
1330
1331 rule = audit_krule_to_rule(&entry->rule);
1332 if (unlikely(!rule))
1333 break;
1334 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1335 rule, sizeof(*rule));
1336 if (skb)
1337 skb_queue_tail(q, skb);
1338 kfree(rule);
1339 }
1340 }
1341 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1342 if (skb)
1343 skb_queue_tail(q, skb);
1344 }
1345
1346 /* List rules using struct audit_rule_data. */
1347 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1348 {
1349 struct sk_buff *skb;
1350 struct audit_entry *e;
1351 int i;
1352
1353 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1354 * iterator to sync with list writers. */
1355 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1356 list_for_each_entry(e, &audit_filter_list[i], list) {
1357 struct audit_rule_data *data;
1358
1359 data = audit_krule_to_data(&e->rule);
1360 if (unlikely(!data))
1361 break;
1362 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1363 data, sizeof(*data) + data->buflen);
1364 if (skb)
1365 skb_queue_tail(q, skb);
1366 kfree(data);
1367 }
1368 }
1369 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1370 list_for_each_entry(e, &audit_inode_hash[i], list) {
1371 struct audit_rule_data *data;
1372
1373 data = audit_krule_to_data(&e->rule);
1374 if (unlikely(!data))
1375 break;
1376 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1377 data, sizeof(*data) + data->buflen);
1378 if (skb)
1379 skb_queue_tail(q, skb);
1380 kfree(data);
1381 }
1382 }
1383 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1384 if (skb)
1385 skb_queue_tail(q, skb);
1386 }
1387
1388 /* Log rule additions and removals */
1389 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1390 struct audit_krule *rule, int res)
1391 {
1392 struct audit_buffer *ab;
1393
1394 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1395 if (!ab)
1396 return;
1397 audit_log_format(ab, "auid=%u", loginuid);
1398 if (sid) {
1399 char *ctx = NULL;
1400 u32 len;
1401 if (selinux_ctxid_to_string(sid, &ctx, &len))
1402 audit_log_format(ab, " ssid=%u", sid);
1403 else
1404 audit_log_format(ab, " subj=%s", ctx);
1405 kfree(ctx);
1406 }
1407 audit_log_format(ab, " %s rule key=", action);
1408 if (rule->filterkey)
1409 audit_log_untrustedstring(ab, rule->filterkey);
1410 else
1411 audit_log_format(ab, "(null)");
1412 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1413 audit_log_end(ab);
1414 }
1415
1416 /**
1417 * audit_receive_filter - apply all rules to the specified message type
1418 * @type: audit message type
1419 * @pid: target pid for netlink audit messages
1420 * @uid: target uid for netlink audit messages
1421 * @seq: netlink audit message sequence (serial) number
1422 * @data: payload data
1423 * @datasz: size of payload data
1424 * @loginuid: loginuid of sender
1425 * @sid: SE Linux Security ID of sender
1426 */
1427 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1428 size_t datasz, uid_t loginuid, u32 sid)
1429 {
1430 struct task_struct *tsk;
1431 struct audit_netlink_list *dest;
1432 int err = 0;
1433 struct audit_entry *entry;
1434
1435 switch (type) {
1436 case AUDIT_LIST:
1437 case AUDIT_LIST_RULES:
1438 /* We can't just spew out the rules here because we might fill
1439 * the available socket buffer space and deadlock waiting for
1440 * auditctl to read from it... which isn't ever going to
1441 * happen if we're actually running in the context of auditctl
1442 * trying to _send_ the stuff */
1443
1444 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1445 if (!dest)
1446 return -ENOMEM;
1447 dest->pid = pid;
1448 skb_queue_head_init(&dest->q);
1449
1450 mutex_lock(&audit_filter_mutex);
1451 if (type == AUDIT_LIST)
1452 audit_list(pid, seq, &dest->q);
1453 else
1454 audit_list_rules(pid, seq, &dest->q);
1455 mutex_unlock(&audit_filter_mutex);
1456
1457 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1458 if (IS_ERR(tsk)) {
1459 skb_queue_purge(&dest->q);
1460 kfree(dest);
1461 err = PTR_ERR(tsk);
1462 }
1463 break;
1464 case AUDIT_ADD:
1465 case AUDIT_ADD_RULE:
1466 if (type == AUDIT_ADD)
1467 entry = audit_rule_to_entry(data);
1468 else
1469 entry = audit_data_to_entry(data, datasz);
1470 if (IS_ERR(entry))
1471 return PTR_ERR(entry);
1472
1473 err = audit_add_rule(entry,
1474 &audit_filter_list[entry->rule.listnr]);
1475 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1476
1477 if (err)
1478 audit_free_rule(entry);
1479 break;
1480 case AUDIT_DEL:
1481 case AUDIT_DEL_RULE:
1482 if (type == AUDIT_DEL)
1483 entry = audit_rule_to_entry(data);
1484 else
1485 entry = audit_data_to_entry(data, datasz);
1486 if (IS_ERR(entry))
1487 return PTR_ERR(entry);
1488
1489 err = audit_del_rule(entry,
1490 &audit_filter_list[entry->rule.listnr]);
1491 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1492 !err);
1493
1494 audit_free_rule(entry);
1495 break;
1496 default:
1497 return -EINVAL;
1498 }
1499
1500 return err;
1501 }
1502
1503 int audit_comparator(const u32 left, const u32 op, const u32 right)
1504 {
1505 switch (op) {
1506 case AUDIT_EQUAL:
1507 return (left == right);
1508 case AUDIT_NOT_EQUAL:
1509 return (left != right);
1510 case AUDIT_LESS_THAN:
1511 return (left < right);
1512 case AUDIT_LESS_THAN_OR_EQUAL:
1513 return (left <= right);
1514 case AUDIT_GREATER_THAN:
1515 return (left > right);
1516 case AUDIT_GREATER_THAN_OR_EQUAL:
1517 return (left >= right);
1518 }
1519 BUG();
1520 return 0;
1521 }
1522
1523 /* Compare given dentry name with last component in given path,
1524 * return of 0 indicates a match. */
1525 int audit_compare_dname_path(const char *dname, const char *path,
1526 int *dirlen)
1527 {
1528 int dlen, plen;
1529 const char *p;
1530
1531 if (!dname || !path)
1532 return 1;
1533
1534 dlen = strlen(dname);
1535 plen = strlen(path);
1536 if (plen < dlen)
1537 return 1;
1538
1539 /* disregard trailing slashes */
1540 p = path + plen - 1;
1541 while ((*p == '/') && (p > path))
1542 p--;
1543
1544 /* find last path component */
1545 p = p - dlen + 1;
1546 if (p < path)
1547 return 1;
1548 else if (p > path) {
1549 if (*--p != '/')
1550 return 1;
1551 else
1552 p++;
1553 }
1554
1555 /* return length of path's directory component */
1556 if (dirlen)
1557 *dirlen = p - path;
1558 return strncmp(p, dname, dlen);
1559 }
1560
1561 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1562 struct audit_krule *rule,
1563 enum audit_state *state)
1564 {
1565 int i;
1566
1567 for (i = 0; i < rule->field_count; i++) {
1568 struct audit_field *f = &rule->fields[i];
1569 int result = 0;
1570
1571 switch (f->type) {
1572 case AUDIT_PID:
1573 result = audit_comparator(cb->creds.pid, f->op, f->val);
1574 break;
1575 case AUDIT_UID:
1576 result = audit_comparator(cb->creds.uid, f->op, f->val);
1577 break;
1578 case AUDIT_GID:
1579 result = audit_comparator(cb->creds.gid, f->op, f->val);
1580 break;
1581 case AUDIT_LOGINUID:
1582 result = audit_comparator(cb->loginuid, f->op, f->val);
1583 break;
1584 }
1585
1586 if (!result)
1587 return 0;
1588 }
1589 switch (rule->action) {
1590 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1591 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1592 }
1593 return 1;
1594 }
1595
1596 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1597 {
1598 struct audit_entry *e;
1599 enum audit_state state;
1600 int ret = 1;
1601
1602 rcu_read_lock();
1603 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1604 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1605 if (state == AUDIT_DISABLED)
1606 ret = 0;
1607 break;
1608 }
1609 }
1610 rcu_read_unlock();
1611
1612 return ret; /* Audit by default */
1613 }
1614
1615 int audit_filter_type(int type)
1616 {
1617 struct audit_entry *e;
1618 int result = 0;
1619
1620 rcu_read_lock();
1621 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1622 goto unlock_and_return;
1623
1624 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1625 list) {
1626 int i;
1627 for (i = 0; i < e->rule.field_count; i++) {
1628 struct audit_field *f = &e->rule.fields[i];
1629 if (f->type == AUDIT_MSGTYPE) {
1630 result = audit_comparator(type, f->op, f->val);
1631 if (!result)
1632 break;
1633 }
1634 }
1635 if (result)
1636 goto unlock_and_return;
1637 }
1638 unlock_and_return:
1639 rcu_read_unlock();
1640 return result;
1641 }
1642
1643 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1644 are selinux fields specified in the rule, 0 otherwise. */
1645 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1646 {
1647 int i;
1648
1649 for (i = 0; i < rule->field_count; i++) {
1650 struct audit_field *f = &rule->fields[i];
1651 switch (f->type) {
1652 case AUDIT_SUBJ_USER:
1653 case AUDIT_SUBJ_ROLE:
1654 case AUDIT_SUBJ_TYPE:
1655 case AUDIT_SUBJ_SEN:
1656 case AUDIT_SUBJ_CLR:
1657 case AUDIT_OBJ_USER:
1658 case AUDIT_OBJ_ROLE:
1659 case AUDIT_OBJ_TYPE:
1660 case AUDIT_OBJ_LEV_LOW:
1661 case AUDIT_OBJ_LEV_HIGH:
1662 return 1;
1663 }
1664 }
1665
1666 return 0;
1667 }
1668
1669 /* This function will re-initialize the se_rule field of all applicable rules.
1670 * It will traverse the filter lists serarching for rules that contain selinux
1671 * specific filter fields. When such a rule is found, it is copied, the
1672 * selinux field is re-initialized, and the old rule is replaced with the
1673 * updated rule. */
1674 int selinux_audit_rule_update(void)
1675 {
1676 struct audit_entry *entry, *n, *nentry;
1677 struct audit_watch *watch;
1678 int i, err = 0;
1679
1680 /* audit_filter_mutex synchronizes the writers */
1681 mutex_lock(&audit_filter_mutex);
1682
1683 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1684 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1685 if (!audit_rule_has_selinux(&entry->rule))
1686 continue;
1687
1688 watch = entry->rule.watch;
1689 nentry = audit_dupe_rule(&entry->rule, watch);
1690 if (unlikely(IS_ERR(nentry))) {
1691 /* save the first error encountered for the
1692 * return value */
1693 if (!err)
1694 err = PTR_ERR(nentry);
1695 audit_panic("error updating selinux filters");
1696 if (watch)
1697 list_del(&entry->rule.rlist);
1698 list_del_rcu(&entry->list);
1699 } else {
1700 if (watch) {
1701 list_add(&nentry->rule.rlist,
1702 &watch->rules);
1703 list_del(&entry->rule.rlist);
1704 }
1705 list_replace_rcu(&entry->list, &nentry->list);
1706 }
1707 call_rcu(&entry->rcu, audit_free_rule_rcu);
1708 }
1709 }
1710
1711 mutex_unlock(&audit_filter_mutex);
1712
1713 return err;
1714 }
1715
1716 /* Update watch data in audit rules based on inotify events. */
1717 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1718 u32 cookie, const char *dname, struct inode *inode)
1719 {
1720 struct audit_parent *parent;
1721
1722 parent = container_of(i_watch, struct audit_parent, wdata);
1723
1724 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1725 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1726 inode->i_ino, 0);
1727 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1728 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1729 /* inotify automatically removes the watch and sends IN_IGNORED */
1730 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1731 audit_remove_parent_watches(parent);
1732 /* inotify does not remove the watch, so remove it manually */
1733 else if(mask & IN_MOVE_SELF) {
1734 audit_remove_parent_watches(parent);
1735 inotify_remove_watch_locked(audit_ih, i_watch);
1736 } else if (mask & IN_IGNORED)
1737 put_inotify_watch(i_watch);
1738 }
Linux with added FPC-III support