projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge branch 'audit.b38' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit...
[deliverable/linux.git] / kernel / auditfilter.c
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 static inline int audit_match_class_bits(int class, u32 *mask)
315 {
316 int i;
317
318 if (classes[class]) {
319 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
320 if (mask[i] & classes[class][i])
321 return 0;
322 }
323 return 1;
324 }
325
326 static int audit_match_signal(struct audit_entry *entry)
327 {
328 struct audit_field *arch = entry->rule.arch_f;
329
330 if (!arch) {
331 /* When arch is unspecified, we must check both masks on biarch
332 * as syscall number alone is ambiguous. */
333 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
334 entry->rule.mask) &&
335 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
336 entry->rule.mask));
337 }
338
339 switch(audit_classify_arch(arch->val)) {
340 case 0: /* native */
341 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
342 entry->rule.mask));
343 case 1: /* 32bit on biarch */
344 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
345 entry->rule.mask));
346 default:
347 return 1;
348 }
349 }
350
351 /* Common user-space to kernel rule translation. */
352 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
353 {
354 unsigned listnr;
355 struct audit_entry *entry;
356 int i, err;
357
358 err = -EINVAL;
359 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
360 switch(listnr) {
361 default:
362 goto exit_err;
363 case AUDIT_FILTER_USER:
364 case AUDIT_FILTER_TYPE:
365 #ifdef CONFIG_AUDITSYSCALL
366 case AUDIT_FILTER_ENTRY:
367 case AUDIT_FILTER_EXIT:
368 case AUDIT_FILTER_TASK:
369 #endif
370 ;
371 }
372 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
373 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
374 goto exit_err;
375 }
376 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
377 goto exit_err;
378 if (rule->field_count > AUDIT_MAX_FIELDS)
379 goto exit_err;
380
381 err = -ENOMEM;
382 entry = audit_init_entry(rule->field_count);
383 if (!entry)
384 goto exit_err;
385
386 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
387 entry->rule.listnr = listnr;
388 entry->rule.action = rule->action;
389 entry->rule.field_count = rule->field_count;
390
391 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
392 entry->rule.mask[i] = rule->mask[i];
393
394 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
395 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
396 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
397 __u32 *class;
398
399 if (!(*p & AUDIT_BIT(bit)))
400 continue;
401 *p &= ~AUDIT_BIT(bit);
402 class = classes[i];
403 if (class) {
404 int j;
405 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
406 entry->rule.mask[j] |= class[j];
407 }
408 }
409
410 return entry;
411
412 exit_err:
413 return ERR_PTR(err);
414 }
415
416 /* Translate struct audit_rule to kernel's rule respresentation.
417 * Exists for backward compatibility with userspace. */
418 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
419 {
420 struct audit_entry *entry;
421 struct audit_field *f;
422 int err = 0;
423 int i;
424
425 entry = audit_to_entry_common(rule);
426 if (IS_ERR(entry))
427 goto exit_nofree;
428
429 for (i = 0; i < rule->field_count; i++) {
430 struct audit_field *f = &entry->rule.fields[i];
431
432 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
433 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
434 f->val = rule->values[i];
435
436 err = -EINVAL;
437 switch(f->type) {
438 default:
439 goto exit_free;
440 case AUDIT_PID:
441 case AUDIT_UID:
442 case AUDIT_EUID:
443 case AUDIT_SUID:
444 case AUDIT_FSUID:
445 case AUDIT_GID:
446 case AUDIT_EGID:
447 case AUDIT_SGID:
448 case AUDIT_FSGID:
449 case AUDIT_LOGINUID:
450 case AUDIT_PERS:
451 case AUDIT_MSGTYPE:
452 case AUDIT_PPID:
453 case AUDIT_DEVMAJOR:
454 case AUDIT_DEVMINOR:
455 case AUDIT_EXIT:
456 case AUDIT_SUCCESS:
457 case AUDIT_ARG0:
458 case AUDIT_ARG1:
459 case AUDIT_ARG2:
460 case AUDIT_ARG3:
461 break;
462 /* arch is only allowed to be = or != */
463 case AUDIT_ARCH:
464 if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL)
465 && (f->op != AUDIT_NEGATE) && (f->op)) {
466 err = -EINVAL;
467 goto exit_free;
468 }
469 entry->rule.arch_f = f;
470 break;
471 case AUDIT_PERM:
472 if (f->val & ~15)
473 goto exit_free;
474 break;
475 case AUDIT_INODE:
476 err = audit_to_inode(&entry->rule, f);
477 if (err)
478 goto exit_free;
479 break;
480 }
481
482 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
483
484 /* Support for legacy operators where
485 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
486 if (f->op & AUDIT_NEGATE)
487 f->op = AUDIT_NOT_EQUAL;
488 else if (!f->op)
489 f->op = AUDIT_EQUAL;
490 else if (f->op == AUDIT_OPERATORS) {
491 err = -EINVAL;
492 goto exit_free;
493 }
494 }
495
496 f = entry->rule.inode_f;
497 if (f) {
498 switch(f->op) {
499 case AUDIT_NOT_EQUAL:
500 entry->rule.inode_f = NULL;
501 case AUDIT_EQUAL:
502 break;
503 default:
504 err = -EINVAL;
505 goto exit_free;
506 }
507 }
508
509 exit_nofree:
510 return entry;
511
512 exit_free:
513 audit_free_rule(entry);
514 return ERR_PTR(err);
515 }
516
517 /* Translate struct audit_rule_data to kernel's rule respresentation. */
518 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
519 size_t datasz)
520 {
521 int err = 0;
522 struct audit_entry *entry;
523 struct audit_field *f;
524 void *bufp;
525 size_t remain = datasz - sizeof(struct audit_rule_data);
526 int i;
527 char *str;
528
529 entry = audit_to_entry_common((struct audit_rule *)data);
530 if (IS_ERR(entry))
531 goto exit_nofree;
532
533 bufp = data->buf;
534 entry->rule.vers_ops = 2;
535 for (i = 0; i < data->field_count; i++) {
536 struct audit_field *f = &entry->rule.fields[i];
537
538 err = -EINVAL;
539 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
540 data->fieldflags[i] & ~AUDIT_OPERATORS)
541 goto exit_free;
542
543 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
544 f->type = data->fields[i];
545 f->val = data->values[i];
546 f->se_str = NULL;
547 f->se_rule = NULL;
548 switch(f->type) {
549 case AUDIT_PID:
550 case AUDIT_UID:
551 case AUDIT_EUID:
552 case AUDIT_SUID:
553 case AUDIT_FSUID:
554 case AUDIT_GID:
555 case AUDIT_EGID:
556 case AUDIT_SGID:
557 case AUDIT_FSGID:
558 case AUDIT_LOGINUID:
559 case AUDIT_PERS:
560 case AUDIT_MSGTYPE:
561 case AUDIT_PPID:
562 case AUDIT_DEVMAJOR:
563 case AUDIT_DEVMINOR:
564 case AUDIT_EXIT:
565 case AUDIT_SUCCESS:
566 case AUDIT_ARG0:
567 case AUDIT_ARG1:
568 case AUDIT_ARG2:
569 case AUDIT_ARG3:
570 break;
571 case AUDIT_ARCH:
572 entry->rule.arch_f = f;
573 break;
574 case AUDIT_SUBJ_USER:
575 case AUDIT_SUBJ_ROLE:
576 case AUDIT_SUBJ_TYPE:
577 case AUDIT_SUBJ_SEN:
578 case AUDIT_SUBJ_CLR:
579 case AUDIT_OBJ_USER:
580 case AUDIT_OBJ_ROLE:
581 case AUDIT_OBJ_TYPE:
582 case AUDIT_OBJ_LEV_LOW:
583 case AUDIT_OBJ_LEV_HIGH:
584 str = audit_unpack_string(&bufp, &remain, f->val);
585 if (IS_ERR(str))
586 goto exit_free;
587 entry->rule.buflen += f->val;
588
589 err = selinux_audit_rule_init(f->type, f->op, str,
590 &f->se_rule);
591 /* Keep currently invalid fields around in case they
592 * become valid after a policy reload. */
593 if (err == -EINVAL) {
594 printk(KERN_WARNING "audit rule for selinux "
595 "\'%s\' is invalid\n", str);
596 err = 0;
597 }
598 if (err) {
599 kfree(str);
600 goto exit_free;
601 } else
602 f->se_str = str;
603 break;
604 case AUDIT_WATCH:
605 str = audit_unpack_string(&bufp, &remain, f->val);
606 if (IS_ERR(str))
607 goto exit_free;
608 entry->rule.buflen += f->val;
609
610 err = audit_to_watch(&entry->rule, str, f->val, f->op);
611 if (err) {
612 kfree(str);
613 goto exit_free;
614 }
615 break;
616 case AUDIT_INODE:
617 err = audit_to_inode(&entry->rule, f);
618 if (err)
619 goto exit_free;
620 break;
621 case AUDIT_FILTERKEY:
622 err = -EINVAL;
623 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
624 goto exit_free;
625 str = audit_unpack_string(&bufp, &remain, f->val);
626 if (IS_ERR(str))
627 goto exit_free;
628 entry->rule.buflen += f->val;
629 entry->rule.filterkey = str;
630 break;
631 case AUDIT_PERM:
632 if (f->val & ~15)
633 goto exit_free;
634 break;
635 default:
636 goto exit_free;
637 }
638 }
639
640 f = entry->rule.inode_f;
641 if (f) {
642 switch(f->op) {
643 case AUDIT_NOT_EQUAL:
644 entry->rule.inode_f = NULL;
645 case AUDIT_EQUAL:
646 break;
647 default:
648 err = -EINVAL;
649 goto exit_free;
650 }
651 }
652
653 exit_nofree:
654 return entry;
655
656 exit_free:
657 audit_free_rule(entry);
658 return ERR_PTR(err);
659 }
660
661 /* Pack a filter field's string representation into data block. */
662 static inline size_t audit_pack_string(void **bufp, char *str)
663 {
664 size_t len = strlen(str);
665
666 memcpy(*bufp, str, len);
667 *bufp += len;
668
669 return len;
670 }
671
672 /* Translate kernel rule respresentation to struct audit_rule.
673 * Exists for backward compatibility with userspace. */
674 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
675 {
676 struct audit_rule *rule;
677 int i;
678
679 rule = kzalloc(sizeof(*rule), GFP_KERNEL);
680 if (unlikely(!rule))
681 return NULL;
682
683 rule->flags = krule->flags | krule->listnr;
684 rule->action = krule->action;
685 rule->field_count = krule->field_count;
686 for (i = 0; i < rule->field_count; i++) {
687 rule->values[i] = krule->fields[i].val;
688 rule->fields[i] = krule->fields[i].type;
689
690 if (krule->vers_ops == 1) {
691 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
692 rule->fields[i] |= AUDIT_NEGATE;
693 } else {
694 rule->fields[i] |= krule->fields[i].op;
695 }
696 }
697 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
698
699 return rule;
700 }
701
702 /* Translate kernel rule respresentation to struct audit_rule_data. */
703 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
704 {
705 struct audit_rule_data *data;
706 void *bufp;
707 int i;
708
709 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
710 if (unlikely(!data))
711 return NULL;
712 memset(data, 0, sizeof(*data));
713
714 data->flags = krule->flags | krule->listnr;
715 data->action = krule->action;
716 data->field_count = krule->field_count;
717 bufp = data->buf;
718 for (i = 0; i < data->field_count; i++) {
719 struct audit_field *f = &krule->fields[i];
720
721 data->fields[i] = f->type;
722 data->fieldflags[i] = f->op;
723 switch(f->type) {
724 case AUDIT_SUBJ_USER:
725 case AUDIT_SUBJ_ROLE:
726 case AUDIT_SUBJ_TYPE:
727 case AUDIT_SUBJ_SEN:
728 case AUDIT_SUBJ_CLR:
729 case AUDIT_OBJ_USER:
730 case AUDIT_OBJ_ROLE:
731 case AUDIT_OBJ_TYPE:
732 case AUDIT_OBJ_LEV_LOW:
733 case AUDIT_OBJ_LEV_HIGH:
734 data->buflen += data->values[i] =
735 audit_pack_string(&bufp, f->se_str);
736 break;
737 case AUDIT_WATCH:
738 data->buflen += data->values[i] =
739 audit_pack_string(&bufp, krule->watch->path);
740 break;
741 case AUDIT_FILTERKEY:
742 data->buflen += data->values[i] =
743 audit_pack_string(&bufp, krule->filterkey);
744 break;
745 default:
746 data->values[i] = f->val;
747 }
748 }
749 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
750
751 return data;
752 }
753
754 /* Compare two rules in kernel format. Considered success if rules
755 * don't match. */
756 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
757 {
758 int i;
759
760 if (a->flags != b->flags ||
761 a->listnr != b->listnr ||
762 a->action != b->action ||
763 a->field_count != b->field_count)
764 return 1;
765
766 for (i = 0; i < a->field_count; i++) {
767 if (a->fields[i].type != b->fields[i].type ||
768 a->fields[i].op != b->fields[i].op)
769 return 1;
770
771 switch(a->fields[i].type) {
772 case AUDIT_SUBJ_USER:
773 case AUDIT_SUBJ_ROLE:
774 case AUDIT_SUBJ_TYPE:
775 case AUDIT_SUBJ_SEN:
776 case AUDIT_SUBJ_CLR:
777 case AUDIT_OBJ_USER:
778 case AUDIT_OBJ_ROLE:
779 case AUDIT_OBJ_TYPE:
780 case AUDIT_OBJ_LEV_LOW:
781 case AUDIT_OBJ_LEV_HIGH:
782 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
783 return 1;
784 break;
785 case AUDIT_WATCH:
786 if (strcmp(a->watch->path, b->watch->path))
787 return 1;
788 break;
789 case AUDIT_FILTERKEY:
790 /* both filterkeys exist based on above type compare */
791 if (strcmp(a->filterkey, b->filterkey))
792 return 1;
793 break;
794 default:
795 if (a->fields[i].val != b->fields[i].val)
796 return 1;
797 }
798 }
799
800 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
801 if (a->mask[i] != b->mask[i])
802 return 1;
803
804 return 0;
805 }
806
807 /* Duplicate the given audit watch. The new watch's rules list is initialized
808 * to an empty list and wlist is undefined. */
809 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
810 {
811 char *path;
812 struct audit_watch *new;
813
814 path = kstrdup(old->path, GFP_KERNEL);
815 if (unlikely(!path))
816 return ERR_PTR(-ENOMEM);
817
818 new = audit_init_watch(path);
819 if (unlikely(IS_ERR(new))) {
820 kfree(path);
821 goto out;
822 }
823
824 new->dev = old->dev;
825 new->ino = old->ino;
826 get_inotify_watch(&old->parent->wdata);
827 new->parent = old->parent;
828
829 out:
830 return new;
831 }
832
833 /* Duplicate selinux field information. The se_rule is opaque, so must be
834 * re-initialized. */
835 static inline int audit_dupe_selinux_field(struct audit_field *df,
836 struct audit_field *sf)
837 {
838 int ret = 0;
839 char *se_str;
840
841 /* our own copy of se_str */
842 se_str = kstrdup(sf->se_str, GFP_KERNEL);
843 if (unlikely(!se_str))
844 return -ENOMEM;
845 df->se_str = se_str;
846
847 /* our own (refreshed) copy of se_rule */
848 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
849 &df->se_rule);
850 /* Keep currently invalid fields around in case they
851 * become valid after a policy reload. */
852 if (ret == -EINVAL) {
853 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
854 "invalid\n", df->se_str);
855 ret = 0;
856 }
857
858 return ret;
859 }
860
861 /* Duplicate an audit rule. This will be a deep copy with the exception
862 * of the watch - that pointer is carried over. The selinux specific fields
863 * will be updated in the copy. The point is to be able to replace the old
864 * rule with the new rule in the filterlist, then free the old rule.
865 * The rlist element is undefined; list manipulations are handled apart from
866 * the initial copy. */
867 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
868 struct audit_watch *watch)
869 {
870 u32 fcount = old->field_count;
871 struct audit_entry *entry;
872 struct audit_krule *new;
873 char *fk;
874 int i, err = 0;
875
876 entry = audit_init_entry(fcount);
877 if (unlikely(!entry))
878 return ERR_PTR(-ENOMEM);
879
880 new = &entry->rule;
881 new->vers_ops = old->vers_ops;
882 new->flags = old->flags;
883 new->listnr = old->listnr;
884 new->action = old->action;
885 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
886 new->mask[i] = old->mask[i];
887 new->buflen = old->buflen;
888 new->inode_f = old->inode_f;
889 new->watch = NULL;
890 new->field_count = old->field_count;
891 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
892
893 /* deep copy this information, updating the se_rule fields, because
894 * the originals will all be freed when the old rule is freed. */
895 for (i = 0; i < fcount; i++) {
896 switch (new->fields[i].type) {
897 case AUDIT_SUBJ_USER:
898 case AUDIT_SUBJ_ROLE:
899 case AUDIT_SUBJ_TYPE:
900 case AUDIT_SUBJ_SEN:
901 case AUDIT_SUBJ_CLR:
902 case AUDIT_OBJ_USER:
903 case AUDIT_OBJ_ROLE:
904 case AUDIT_OBJ_TYPE:
905 case AUDIT_OBJ_LEV_LOW:
906 case AUDIT_OBJ_LEV_HIGH:
907 err = audit_dupe_selinux_field(&new->fields[i],
908 &old->fields[i]);
909 break;
910 case AUDIT_FILTERKEY:
911 fk = kstrdup(old->filterkey, GFP_KERNEL);
912 if (unlikely(!fk))
913 err = -ENOMEM;
914 else
915 new->filterkey = fk;
916 }
917 if (err) {
918 audit_free_rule(entry);
919 return ERR_PTR(err);
920 }
921 }
922
923 if (watch) {
924 audit_get_watch(watch);
925 new->watch = watch;
926 }
927
928 return entry;
929 }
930
931 /* Update inode info in audit rules based on filesystem event. */
932 static void audit_update_watch(struct audit_parent *parent,
933 const char *dname, dev_t dev,
934 unsigned long ino, unsigned invalidating)
935 {
936 struct audit_watch *owatch, *nwatch, *nextw;
937 struct audit_krule *r, *nextr;
938 struct audit_entry *oentry, *nentry;
939 struct audit_buffer *ab;
940
941 mutex_lock(&audit_filter_mutex);
942 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
943 if (audit_compare_dname_path(dname, owatch->path, NULL))
944 continue;
945
946 /* If the update involves invalidating rules, do the inode-based
947 * filtering now, so we don't omit records. */
948 if (invalidating &&
949 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
950 audit_set_auditable(current->audit_context);
951
952 nwatch = audit_dupe_watch(owatch);
953 if (unlikely(IS_ERR(nwatch))) {
954 mutex_unlock(&audit_filter_mutex);
955 audit_panic("error updating watch, skipping");
956 return;
957 }
958 nwatch->dev = dev;
959 nwatch->ino = ino;
960
961 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
962
963 oentry = container_of(r, struct audit_entry, rule);
964 list_del(&oentry->rule.rlist);
965 list_del_rcu(&oentry->list);
966
967 nentry = audit_dupe_rule(&oentry->rule, nwatch);
968 if (unlikely(IS_ERR(nentry)))
969 audit_panic("error updating watch, removing");
970 else {
971 int h = audit_hash_ino((u32)ino);
972 list_add(&nentry->rule.rlist, &nwatch->rules);
973 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
974 }
975
976 call_rcu(&oentry->rcu, audit_free_rule_rcu);
977 }
978
979 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
980 audit_log_format(ab, "op=updated rules specifying path=");
981 audit_log_untrustedstring(ab, owatch->path);
982 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
983 audit_log_format(ab, " list=%d res=1", r->listnr);
984 audit_log_end(ab);
985
986 audit_remove_watch(owatch);
987 goto add_watch_to_parent; /* event applies to a single watch */
988 }
989 mutex_unlock(&audit_filter_mutex);
990 return;
991
992 add_watch_to_parent:
993 list_add(&nwatch->wlist, &parent->watches);
994 mutex_unlock(&audit_filter_mutex);
995 return;
996 }
997
998 /* Remove all watches & rules associated with a parent that is going away. */
999 static void audit_remove_parent_watches(struct audit_parent *parent)
1000 {
1001 struct audit_watch *w, *nextw;
1002 struct audit_krule *r, *nextr;
1003 struct audit_entry *e;
1004 struct audit_buffer *ab;
1005
1006 mutex_lock(&audit_filter_mutex);
1007 parent->flags |= AUDIT_PARENT_INVALID;
1008 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
1009 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
1010 e = container_of(r, struct audit_entry, rule);
1011
1012 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1013 audit_log_format(ab, "op=remove rule path=");
1014 audit_log_untrustedstring(ab, w->path);
1015 if (r->filterkey) {
1016 audit_log_format(ab, " key=");
1017 audit_log_untrustedstring(ab, r->filterkey);
1018 } else
1019 audit_log_format(ab, " key=(null)");
1020 audit_log_format(ab, " list=%d res=1", r->listnr);
1021 audit_log_end(ab);
1022
1023 list_del(&r->rlist);
1024 list_del_rcu(&e->list);
1025 call_rcu(&e->rcu, audit_free_rule_rcu);
1026 }
1027 audit_remove_watch(w);
1028 }
1029 mutex_unlock(&audit_filter_mutex);
1030 }
1031
1032 /* Unregister inotify watches for parents on in_list.
1033 * Generates an IN_IGNORED event. */
1034 static void audit_inotify_unregister(struct list_head *in_list)
1035 {
1036 struct audit_parent *p, *n;
1037
1038 list_for_each_entry_safe(p, n, in_list, ilist) {
1039 list_del(&p->ilist);
1040 inotify_rm_watch(audit_ih, &p->wdata);
1041 /* the put matching the get in audit_do_del_rule() */
1042 put_inotify_watch(&p->wdata);
1043 }
1044 }
1045
1046 /* Find an existing audit rule.
1047 * Caller must hold audit_filter_mutex to prevent stale rule data. */
1048 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
1049 struct list_head *list)
1050 {
1051 struct audit_entry *e, *found = NULL;
1052 int h;
1053
1054 if (entry->rule.watch) {
1055 /* we don't know the inode number, so must walk entire hash */
1056 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
1057 list = &audit_inode_hash[h];
1058 list_for_each_entry(e, list, list)
1059 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1060 found = e;
1061 goto out;
1062 }
1063 }
1064 goto out;
1065 }
1066
1067 list_for_each_entry(e, list, list)
1068 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1069 found = e;
1070 goto out;
1071 }
1072
1073 out:
1074 return found;
1075 }
1076
1077 /* Get path information necessary for adding watches. */
1078 static int audit_get_nd(char *path, struct nameidata **ndp,
1079 struct nameidata **ndw)
1080 {
1081 struct nameidata *ndparent, *ndwatch;
1082 int err;
1083
1084 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1085 if (unlikely(!ndparent))
1086 return -ENOMEM;
1087
1088 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1089 if (unlikely(!ndwatch)) {
1090 kfree(ndparent);
1091 return -ENOMEM;
1092 }
1093
1094 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1095 if (err) {
1096 kfree(ndparent);
1097 kfree(ndwatch);
1098 return err;
1099 }
1100
1101 err = path_lookup(path, 0, ndwatch);
1102 if (err) {
1103 kfree(ndwatch);
1104 ndwatch = NULL;
1105 }
1106
1107 *ndp = ndparent;
1108 *ndw = ndwatch;
1109
1110 return 0;
1111 }
1112
1113 /* Release resources used for watch path information. */
1114 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1115 {
1116 if (ndp) {
1117 path_release(ndp);
1118 kfree(ndp);
1119 }
1120 if (ndw) {
1121 path_release(ndw);
1122 kfree(ndw);
1123 }
1124 }
1125
1126 /* Associate the given rule with an existing parent inotify_watch.
1127 * Caller must hold audit_filter_mutex. */
1128 static void audit_add_to_parent(struct audit_krule *krule,
1129 struct audit_parent *parent)
1130 {
1131 struct audit_watch *w, *watch = krule->watch;
1132 int watch_found = 0;
1133
1134 list_for_each_entry(w, &parent->watches, wlist) {
1135 if (strcmp(watch->path, w->path))
1136 continue;
1137
1138 watch_found = 1;
1139
1140 /* put krule's and initial refs to temporary watch */
1141 audit_put_watch(watch);
1142 audit_put_watch(watch);
1143
1144 audit_get_watch(w);
1145 krule->watch = watch = w;
1146 break;
1147 }
1148
1149 if (!watch_found) {
1150 get_inotify_watch(&parent->wdata);
1151 watch->parent = parent;
1152
1153 list_add(&watch->wlist, &parent->watches);
1154 }
1155 list_add(&krule->rlist, &watch->rules);
1156 }
1157
1158 /* Find a matching watch entry, or add this one.
1159 * Caller must hold audit_filter_mutex. */
1160 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1161 struct nameidata *ndw)
1162 {
1163 struct audit_watch *watch = krule->watch;
1164 struct inotify_watch *i_watch;
1165 struct audit_parent *parent;
1166 int ret = 0;
1167
1168 /* update watch filter fields */
1169 if (ndw) {
1170 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1171 watch->ino = ndw->dentry->d_inode->i_ino;
1172 }
1173
1174 /* The audit_filter_mutex must not be held during inotify calls because
1175 * we hold it during inotify event callback processing. If an existing
1176 * inotify watch is found, inotify_find_watch() grabs a reference before
1177 * returning.
1178 */
1179 mutex_unlock(&audit_filter_mutex);
1180
1181 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1182 parent = audit_init_parent(ndp);
1183 if (IS_ERR(parent)) {
1184 /* caller expects mutex locked */
1185 mutex_lock(&audit_filter_mutex);
1186 return PTR_ERR(parent);
1187 }
1188 } else
1189 parent = container_of(i_watch, struct audit_parent, wdata);
1190
1191 mutex_lock(&audit_filter_mutex);
1192
1193 /* parent was moved before we took audit_filter_mutex */
1194 if (parent->flags & AUDIT_PARENT_INVALID)
1195 ret = -ENOENT;
1196 else
1197 audit_add_to_parent(krule, parent);
1198
1199 /* match get in audit_init_parent or inotify_find_watch */
1200 put_inotify_watch(&parent->wdata);
1201 return ret;
1202 }
1203
1204 /* Add rule to given filterlist if not a duplicate. */
1205 static inline int audit_add_rule(struct audit_entry *entry,
1206 struct list_head *list)
1207 {
1208 struct audit_entry *e;
1209 struct audit_field *inode_f = entry->rule.inode_f;
1210 struct audit_watch *watch = entry->rule.watch;
1211 struct nameidata *ndp, *ndw;
1212 int h, err, putnd_needed = 0;
1213 #ifdef CONFIG_AUDITSYSCALL
1214 int dont_count = 0;
1215
1216 /* If either of these, don't count towards total */
1217 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1218 entry->rule.listnr == AUDIT_FILTER_TYPE)
1219 dont_count = 1;
1220 #endif
1221
1222 if (inode_f) {
1223 h = audit_hash_ino(inode_f->val);
1224 list = &audit_inode_hash[h];
1225 }
1226
1227 mutex_lock(&audit_filter_mutex);
1228 e = audit_find_rule(entry, list);
1229 mutex_unlock(&audit_filter_mutex);
1230 if (e) {
1231 err = -EEXIST;
1232 goto error;
1233 }
1234
1235 /* Avoid calling path_lookup under audit_filter_mutex. */
1236 if (watch) {
1237 err = audit_get_nd(watch->path, &ndp, &ndw);
1238 if (err)
1239 goto error;
1240 putnd_needed = 1;
1241 }
1242
1243 mutex_lock(&audit_filter_mutex);
1244 if (watch) {
1245 /* audit_filter_mutex is dropped and re-taken during this call */
1246 err = audit_add_watch(&entry->rule, ndp, ndw);
1247 if (err) {
1248 mutex_unlock(&audit_filter_mutex);
1249 goto error;
1250 }
1251 h = audit_hash_ino((u32)watch->ino);
1252 list = &audit_inode_hash[h];
1253 }
1254
1255 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1256 list_add_rcu(&entry->list, list);
1257 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1258 } else {
1259 list_add_tail_rcu(&entry->list, list);
1260 }
1261 #ifdef CONFIG_AUDITSYSCALL
1262 if (!dont_count)
1263 audit_n_rules++;
1264
1265 if (!audit_match_signal(entry))
1266 audit_signals++;
1267 #endif
1268 mutex_unlock(&audit_filter_mutex);
1269
1270 if (putnd_needed)
1271 audit_put_nd(ndp, ndw);
1272
1273 return 0;
1274
1275 error:
1276 if (putnd_needed)
1277 audit_put_nd(ndp, ndw);
1278 if (watch)
1279 audit_put_watch(watch); /* tmp watch, matches initial get */
1280 return err;
1281 }
1282
1283 /* Remove an existing rule from filterlist. */
1284 static inline int audit_del_rule(struct audit_entry *entry,
1285 struct list_head *list)
1286 {
1287 struct audit_entry *e;
1288 struct audit_field *inode_f = entry->rule.inode_f;
1289 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1290 LIST_HEAD(inotify_list);
1291 int h, ret = 0;
1292 #ifdef CONFIG_AUDITSYSCALL
1293 int dont_count = 0;
1294
1295 /* If either of these, don't count towards total */
1296 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1297 entry->rule.listnr == AUDIT_FILTER_TYPE)
1298 dont_count = 1;
1299 #endif
1300
1301 if (inode_f) {
1302 h = audit_hash_ino(inode_f->val);
1303 list = &audit_inode_hash[h];
1304 }
1305
1306 mutex_lock(&audit_filter_mutex);
1307 e = audit_find_rule(entry, list);
1308 if (!e) {
1309 mutex_unlock(&audit_filter_mutex);
1310 ret = -ENOENT;
1311 goto out;
1312 }
1313
1314 watch = e->rule.watch;
1315 if (watch) {
1316 struct audit_parent *parent = watch->parent;
1317
1318 list_del(&e->rule.rlist);
1319
1320 if (list_empty(&watch->rules)) {
1321 audit_remove_watch(watch);
1322
1323 if (list_empty(&parent->watches)) {
1324 /* Put parent on the inotify un-registration
1325 * list. Grab a reference before releasing
1326 * audit_filter_mutex, to be released in
1327 * audit_inotify_unregister(). */
1328 list_add(&parent->ilist, &inotify_list);
1329 get_inotify_watch(&parent->wdata);
1330 }
1331 }
1332 }
1333
1334 list_del_rcu(&e->list);
1335 call_rcu(&e->rcu, audit_free_rule_rcu);
1336
1337 #ifdef CONFIG_AUDITSYSCALL
1338 if (!dont_count)
1339 audit_n_rules--;
1340
1341 if (!audit_match_signal(entry))
1342 audit_signals--;
1343 #endif
1344 mutex_unlock(&audit_filter_mutex);
1345
1346 if (!list_empty(&inotify_list))
1347 audit_inotify_unregister(&inotify_list);
1348
1349 out:
1350 if (tmp_watch)
1351 audit_put_watch(tmp_watch); /* match initial get */
1352
1353 return ret;
1354 }
1355
1356 /* List rules using struct audit_rule. Exists for backward
1357 * compatibility with userspace. */
1358 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1359 {
1360 struct sk_buff *skb;
1361 struct audit_entry *entry;
1362 int i;
1363
1364 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1365 * iterator to sync with list writers. */
1366 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1367 list_for_each_entry(entry, &audit_filter_list[i], list) {
1368 struct audit_rule *rule;
1369
1370 rule = audit_krule_to_rule(&entry->rule);
1371 if (unlikely(!rule))
1372 break;
1373 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1374 rule, sizeof(*rule));
1375 if (skb)
1376 skb_queue_tail(q, skb);
1377 kfree(rule);
1378 }
1379 }
1380 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1381 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1382 struct audit_rule *rule;
1383
1384 rule = audit_krule_to_rule(&entry->rule);
1385 if (unlikely(!rule))
1386 break;
1387 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1388 rule, sizeof(*rule));
1389 if (skb)
1390 skb_queue_tail(q, skb);
1391 kfree(rule);
1392 }
1393 }
1394 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1395 if (skb)
1396 skb_queue_tail(q, skb);
1397 }
1398
1399 /* List rules using struct audit_rule_data. */
1400 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1401 {
1402 struct sk_buff *skb;
1403 struct audit_entry *e;
1404 int i;
1405
1406 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1407 * iterator to sync with list writers. */
1408 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1409 list_for_each_entry(e, &audit_filter_list[i], list) {
1410 struct audit_rule_data *data;
1411
1412 data = audit_krule_to_data(&e->rule);
1413 if (unlikely(!data))
1414 break;
1415 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1416 data, sizeof(*data) + data->buflen);
1417 if (skb)
1418 skb_queue_tail(q, skb);
1419 kfree(data);
1420 }
1421 }
1422 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1423 list_for_each_entry(e, &audit_inode_hash[i], list) {
1424 struct audit_rule_data *data;
1425
1426 data = audit_krule_to_data(&e->rule);
1427 if (unlikely(!data))
1428 break;
1429 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1430 data, sizeof(*data) + data->buflen);
1431 if (skb)
1432 skb_queue_tail(q, skb);
1433 kfree(data);
1434 }
1435 }
1436 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1437 if (skb)
1438 skb_queue_tail(q, skb);
1439 }
1440
1441 /* Log rule additions and removals */
1442 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1443 struct audit_krule *rule, int res)
1444 {
1445 struct audit_buffer *ab;
1446
1447 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1448 if (!ab)
1449 return;
1450 audit_log_format(ab, "auid=%u", loginuid);
1451 if (sid) {
1452 char *ctx = NULL;
1453 u32 len;
1454 if (selinux_sid_to_string(sid, &ctx, &len))
1455 audit_log_format(ab, " ssid=%u", sid);
1456 else
1457 audit_log_format(ab, " subj=%s", ctx);
1458 kfree(ctx);
1459 }
1460 audit_log_format(ab, " op=%s rule key=", action);
1461 if (rule->filterkey)
1462 audit_log_untrustedstring(ab, rule->filterkey);
1463 else
1464 audit_log_format(ab, "(null)");
1465 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1466 audit_log_end(ab);
1467 }
1468
1469 /**
1470 * audit_receive_filter - apply all rules to the specified message type
1471 * @type: audit message type
1472 * @pid: target pid for netlink audit messages
1473 * @uid: target uid for netlink audit messages
1474 * @seq: netlink audit message sequence (serial) number
1475 * @data: payload data
1476 * @datasz: size of payload data
1477 * @loginuid: loginuid of sender
1478 * @sid: SE Linux Security ID of sender
1479 */
1480 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1481 size_t datasz, uid_t loginuid, u32 sid)
1482 {
1483 struct task_struct *tsk;
1484 struct audit_netlink_list *dest;
1485 int err = 0;
1486 struct audit_entry *entry;
1487
1488 switch (type) {
1489 case AUDIT_LIST:
1490 case AUDIT_LIST_RULES:
1491 /* We can't just spew out the rules here because we might fill
1492 * the available socket buffer space and deadlock waiting for
1493 * auditctl to read from it... which isn't ever going to
1494 * happen if we're actually running in the context of auditctl
1495 * trying to _send_ the stuff */
1496
1497 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1498 if (!dest)
1499 return -ENOMEM;
1500 dest->pid = pid;
1501 skb_queue_head_init(&dest->q);
1502
1503 mutex_lock(&audit_filter_mutex);
1504 if (type == AUDIT_LIST)
1505 audit_list(pid, seq, &dest->q);
1506 else
1507 audit_list_rules(pid, seq, &dest->q);
1508 mutex_unlock(&audit_filter_mutex);
1509
1510 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1511 if (IS_ERR(tsk)) {
1512 skb_queue_purge(&dest->q);
1513 kfree(dest);
1514 err = PTR_ERR(tsk);
1515 }
1516 break;
1517 case AUDIT_ADD:
1518 case AUDIT_ADD_RULE:
1519 if (type == AUDIT_ADD)
1520 entry = audit_rule_to_entry(data);
1521 else
1522 entry = audit_data_to_entry(data, datasz);
1523 if (IS_ERR(entry))
1524 return PTR_ERR(entry);
1525
1526 err = audit_add_rule(entry,
1527 &audit_filter_list[entry->rule.listnr]);
1528 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1529
1530 if (err)
1531 audit_free_rule(entry);
1532 break;
1533 case AUDIT_DEL:
1534 case AUDIT_DEL_RULE:
1535 if (type == AUDIT_DEL)
1536 entry = audit_rule_to_entry(data);
1537 else
1538 entry = audit_data_to_entry(data, datasz);
1539 if (IS_ERR(entry))
1540 return PTR_ERR(entry);
1541
1542 err = audit_del_rule(entry,
1543 &audit_filter_list[entry->rule.listnr]);
1544 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1545 !err);
1546
1547 audit_free_rule(entry);
1548 break;
1549 default:
1550 return -EINVAL;
1551 }
1552
1553 return err;
1554 }
1555
1556 int audit_comparator(const u32 left, const u32 op, const u32 right)
1557 {
1558 switch (op) {
1559 case AUDIT_EQUAL:
1560 return (left == right);
1561 case AUDIT_NOT_EQUAL:
1562 return (left != right);
1563 case AUDIT_LESS_THAN:
1564 return (left < right);
1565 case AUDIT_LESS_THAN_OR_EQUAL:
1566 return (left <= right);
1567 case AUDIT_GREATER_THAN:
1568 return (left > right);
1569 case AUDIT_GREATER_THAN_OR_EQUAL:
1570 return (left >= right);
1571 }
1572 BUG();
1573 return 0;
1574 }
1575
1576 /* Compare given dentry name with last component in given path,
1577 * return of 0 indicates a match. */
1578 int audit_compare_dname_path(const char *dname, const char *path,
1579 int *dirlen)
1580 {
1581 int dlen, plen;
1582 const char *p;
1583
1584 if (!dname || !path)
1585 return 1;
1586
1587 dlen = strlen(dname);
1588 plen = strlen(path);
1589 if (plen < dlen)
1590 return 1;
1591
1592 /* disregard trailing slashes */
1593 p = path + plen - 1;
1594 while ((*p == '/') && (p > path))
1595 p--;
1596
1597 /* find last path component */
1598 p = p - dlen + 1;
1599 if (p < path)
1600 return 1;
1601 else if (p > path) {
1602 if (*--p != '/')
1603 return 1;
1604 else
1605 p++;
1606 }
1607
1608 /* return length of path's directory component */
1609 if (dirlen)
1610 *dirlen = p - path;
1611 return strncmp(p, dname, dlen);
1612 }
1613
1614 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1615 struct audit_krule *rule,
1616 enum audit_state *state)
1617 {
1618 int i;
1619
1620 for (i = 0; i < rule->field_count; i++) {
1621 struct audit_field *f = &rule->fields[i];
1622 int result = 0;
1623
1624 switch (f->type) {
1625 case AUDIT_PID:
1626 result = audit_comparator(cb->creds.pid, f->op, f->val);
1627 break;
1628 case AUDIT_UID:
1629 result = audit_comparator(cb->creds.uid, f->op, f->val);
1630 break;
1631 case AUDIT_GID:
1632 result = audit_comparator(cb->creds.gid, f->op, f->val);
1633 break;
1634 case AUDIT_LOGINUID:
1635 result = audit_comparator(cb->loginuid, f->op, f->val);
1636 break;
1637 }
1638
1639 if (!result)
1640 return 0;
1641 }
1642 switch (rule->action) {
1643 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1644 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1645 }
1646 return 1;
1647 }
1648
1649 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1650 {
1651 enum audit_state state = AUDIT_DISABLED;
1652 struct audit_entry *e;
1653 int ret = 1;
1654
1655 rcu_read_lock();
1656 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1657 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1658 if (state == AUDIT_DISABLED)
1659 ret = 0;
1660 break;
1661 }
1662 }
1663 rcu_read_unlock();
1664
1665 return ret; /* Audit by default */
1666 }
1667
1668 int audit_filter_type(int type)
1669 {
1670 struct audit_entry *e;
1671 int result = 0;
1672
1673 rcu_read_lock();
1674 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1675 goto unlock_and_return;
1676
1677 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1678 list) {
1679 int i;
1680 for (i = 0; i < e->rule.field_count; i++) {
1681 struct audit_field *f = &e->rule.fields[i];
1682 if (f->type == AUDIT_MSGTYPE) {
1683 result = audit_comparator(type, f->op, f->val);
1684 if (!result)
1685 break;
1686 }
1687 }
1688 if (result)
1689 goto unlock_and_return;
1690 }
1691 unlock_and_return:
1692 rcu_read_unlock();
1693 return result;
1694 }
1695
1696 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1697 are selinux fields specified in the rule, 0 otherwise. */
1698 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1699 {
1700 int i;
1701
1702 for (i = 0; i < rule->field_count; i++) {
1703 struct audit_field *f = &rule->fields[i];
1704 switch (f->type) {
1705 case AUDIT_SUBJ_USER:
1706 case AUDIT_SUBJ_ROLE:
1707 case AUDIT_SUBJ_TYPE:
1708 case AUDIT_SUBJ_SEN:
1709 case AUDIT_SUBJ_CLR:
1710 case AUDIT_OBJ_USER:
1711 case AUDIT_OBJ_ROLE:
1712 case AUDIT_OBJ_TYPE:
1713 case AUDIT_OBJ_LEV_LOW:
1714 case AUDIT_OBJ_LEV_HIGH:
1715 return 1;
1716 }
1717 }
1718
1719 return 0;
1720 }
1721
1722 /* This function will re-initialize the se_rule field of all applicable rules.
1723 * It will traverse the filter lists serarching for rules that contain selinux
1724 * specific filter fields. When such a rule is found, it is copied, the
1725 * selinux field is re-initialized, and the old rule is replaced with the
1726 * updated rule. */
1727 int selinux_audit_rule_update(void)
1728 {
1729 struct audit_entry *entry, *n, *nentry;
1730 struct audit_watch *watch;
1731 int i, err = 0;
1732
1733 /* audit_filter_mutex synchronizes the writers */
1734 mutex_lock(&audit_filter_mutex);
1735
1736 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1737 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1738 if (!audit_rule_has_selinux(&entry->rule))
1739 continue;
1740
1741 watch = entry->rule.watch;
1742 nentry = audit_dupe_rule(&entry->rule, watch);
1743 if (unlikely(IS_ERR(nentry))) {
1744 /* save the first error encountered for the
1745 * return value */
1746 if (!err)
1747 err = PTR_ERR(nentry);
1748 audit_panic("error updating selinux filters");
1749 if (watch)
1750 list_del(&entry->rule.rlist);
1751 list_del_rcu(&entry->list);
1752 } else {
1753 if (watch) {
1754 list_add(&nentry->rule.rlist,
1755 &watch->rules);
1756 list_del(&entry->rule.rlist);
1757 }
1758 list_replace_rcu(&entry->list, &nentry->list);
1759 }
1760 call_rcu(&entry->rcu, audit_free_rule_rcu);
1761 }
1762 }
1763
1764 mutex_unlock(&audit_filter_mutex);
1765
1766 return err;
1767 }
1768
1769 /* Update watch data in audit rules based on inotify events. */
1770 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1771 u32 cookie, const char *dname, struct inode *inode)
1772 {
1773 struct audit_parent *parent;
1774
1775 parent = container_of(i_watch, struct audit_parent, wdata);
1776
1777 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1778 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1779 inode->i_ino, 0);
1780 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1781 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1782 /* inotify automatically removes the watch and sends IN_IGNORED */
1783 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1784 audit_remove_parent_watches(parent);
1785 /* inotify does not remove the watch, so remove it manually */
1786 else if(mask & IN_MOVE_SELF) {
1787 audit_remove_parent_watches(parent);
1788 inotify_remove_watch_locked(audit_ih, i_watch);
1789 } else if (mask & IN_IGNORED)
1790 put_inotify_watch(i_watch);
1791 }
Linux kernel - Deliverables
This page took 0.069451 seconds and 6 git commands to generate.