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[MIPS] SMTC: Fix TLB sizing bug for TLB of 64 >= entries
[linux-2.6/mini2440.git] / kernel / auditfilter.c
blob9c8c23227c7f28970f64de6e21cab6e8bfa08415
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_MSGTYPE:
415 case AUDIT_PPID:
416 case AUDIT_DEVMAJOR:
417 case AUDIT_DEVMINOR:
418 case AUDIT_EXIT:
419 case AUDIT_SUCCESS:
420 case AUDIT_ARG0:
421 case AUDIT_ARG1:
422 case AUDIT_ARG2:
423 case AUDIT_ARG3:
424 break;
425 /* arch is only allowed to be = or != */
426 case AUDIT_ARCH:
427 if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL)
428 && (f->op != AUDIT_NEGATE) && (f->op)) {
429 err = -EINVAL;
430 goto exit_free;
431 }
432 break;
433 case AUDIT_PERM:
434 if (f->val & ~15)
435 goto exit_free;
436 break;
437 case AUDIT_INODE:
438 err = audit_to_inode(&entry->rule, f);
439 if (err)
440 goto exit_free;
441 break;
442 }
443
444 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
445
446 /* Support for legacy operators where
447 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
448 if (f->op & AUDIT_NEGATE)
449 f->op = AUDIT_NOT_EQUAL;
450 else if (!f->op)
451 f->op = AUDIT_EQUAL;
452 else if (f->op == AUDIT_OPERATORS) {
453 err = -EINVAL;
454 goto exit_free;
455 }
456 }
457
458 f = entry->rule.inode_f;
459 if (f) {
460 switch(f->op) {
461 case AUDIT_NOT_EQUAL:
462 entry->rule.inode_f = NULL;
463 case AUDIT_EQUAL:
464 break;
465 default:
466 err = -EINVAL;
467 goto exit_free;
468 }
469 }
470
471 exit_nofree:
472 return entry;
473
474 exit_free:
475 audit_free_rule(entry);
476 return ERR_PTR(err);
477 }
478
479 /* Translate struct audit_rule_data to kernel's rule respresentation. */
480 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
481 size_t datasz)
482 {
483 int err = 0;
484 struct audit_entry *entry;
485 struct audit_field *f;
486 void *bufp;
487 size_t remain = datasz - sizeof(struct audit_rule_data);
488 int i;
489 char *str;
490
491 entry = audit_to_entry_common((struct audit_rule *)data);
492 if (IS_ERR(entry))
493 goto exit_nofree;
494
495 bufp = data->buf;
496 entry->rule.vers_ops = 2;
497 for (i = 0; i < data->field_count; i++) {
498 struct audit_field *f = &entry->rule.fields[i];
499
500 err = -EINVAL;
501 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
502 data->fieldflags[i] & ~AUDIT_OPERATORS)
503 goto exit_free;
504
505 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
506 f->type = data->fields[i];
507 f->val = data->values[i];
508 f->se_str = NULL;
509 f->se_rule = NULL;
510 switch(f->type) {
511 case AUDIT_PID:
512 case AUDIT_UID:
513 case AUDIT_EUID:
514 case AUDIT_SUID:
515 case AUDIT_FSUID:
516 case AUDIT_GID:
517 case AUDIT_EGID:
518 case AUDIT_SGID:
519 case AUDIT_FSGID:
520 case AUDIT_LOGINUID:
521 case AUDIT_PERS:
522 case AUDIT_ARCH:
523 case AUDIT_MSGTYPE:
524 case AUDIT_PPID:
525 case AUDIT_DEVMAJOR:
526 case AUDIT_DEVMINOR:
527 case AUDIT_EXIT:
528 case AUDIT_SUCCESS:
529 case AUDIT_ARG0:
530 case AUDIT_ARG1:
531 case AUDIT_ARG2:
532 case AUDIT_ARG3:
533 break;
534 case AUDIT_SUBJ_USER:
535 case AUDIT_SUBJ_ROLE:
536 case AUDIT_SUBJ_TYPE:
537 case AUDIT_SUBJ_SEN:
538 case AUDIT_SUBJ_CLR:
539 case AUDIT_OBJ_USER:
540 case AUDIT_OBJ_ROLE:
541 case AUDIT_OBJ_TYPE:
542 case AUDIT_OBJ_LEV_LOW:
543 case AUDIT_OBJ_LEV_HIGH:
544 str = audit_unpack_string(&bufp, &remain, f->val);
545 if (IS_ERR(str))
546 goto exit_free;
547 entry->rule.buflen += f->val;
548
549 err = selinux_audit_rule_init(f->type, f->op, str,
550 &f->se_rule);
551 /* Keep currently invalid fields around in case they
552 * become valid after a policy reload. */
553 if (err == -EINVAL) {
554 printk(KERN_WARNING "audit rule for selinux "
555 "\'%s\' is invalid\n", str);
556 err = 0;
557 }
558 if (err) {
559 kfree(str);
560 goto exit_free;
561 } else
562 f->se_str = str;
563 break;
564 case AUDIT_WATCH:
565 str = audit_unpack_string(&bufp, &remain, f->val);
566 if (IS_ERR(str))
567 goto exit_free;
568 entry->rule.buflen += f->val;
569
570 err = audit_to_watch(&entry->rule, str, f->val, f->op);
571 if (err) {
572 kfree(str);
573 goto exit_free;
574 }
575 break;
576 case AUDIT_INODE:
577 err = audit_to_inode(&entry->rule, f);
578 if (err)
579 goto exit_free;
580 break;
581 case AUDIT_FILTERKEY:
582 err = -EINVAL;
583 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
584 goto exit_free;
585 str = audit_unpack_string(&bufp, &remain, f->val);
586 if (IS_ERR(str))
587 goto exit_free;
588 entry->rule.buflen += f->val;
589 entry->rule.filterkey = str;
590 break;
591 case AUDIT_PERM:
592 if (f->val & ~15)
593 goto exit_free;
594 break;
595 default:
596 goto exit_free;
597 }
598 }
599
600 f = entry->rule.inode_f;
601 if (f) {
602 switch(f->op) {
603 case AUDIT_NOT_EQUAL:
604 entry->rule.inode_f = NULL;
605 case AUDIT_EQUAL:
606 break;
607 default:
608 err = -EINVAL;
609 goto exit_free;
610 }
611 }
612
613 exit_nofree:
614 return entry;
615
616 exit_free:
617 audit_free_rule(entry);
618 return ERR_PTR(err);
619 }
620
621 /* Pack a filter field's string representation into data block. */
622 static inline size_t audit_pack_string(void **bufp, char *str)
623 {
624 size_t len = strlen(str);
625
626 memcpy(*bufp, str, len);
627 *bufp += len;
628
629 return len;
630 }
631
632 /* Translate kernel rule respresentation to struct audit_rule.
633 * Exists for backward compatibility with userspace. */
634 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
635 {
636 struct audit_rule *rule;
637 int i;
638
639 rule = kzalloc(sizeof(*rule), GFP_KERNEL);
640 if (unlikely(!rule))
641 return NULL;
642
643 rule->flags = krule->flags | krule->listnr;
644 rule->action = krule->action;
645 rule->field_count = krule->field_count;
646 for (i = 0; i < rule->field_count; i++) {
647 rule->values[i] = krule->fields[i].val;
648 rule->fields[i] = krule->fields[i].type;
649
650 if (krule->vers_ops == 1) {
651 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
652 rule->fields[i] |= AUDIT_NEGATE;
653 } else {
654 rule->fields[i] |= krule->fields[i].op;
655 }
656 }
657 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
658
659 return rule;
660 }
661
662 /* Translate kernel rule respresentation to struct audit_rule_data. */
663 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
664 {
665 struct audit_rule_data *data;
666 void *bufp;
667 int i;
668
669 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
670 if (unlikely(!data))
671 return NULL;
672 memset(data, 0, sizeof(*data));
673
674 data->flags = krule->flags | krule->listnr;
675 data->action = krule->action;
676 data->field_count = krule->field_count;
677 bufp = data->buf;
678 for (i = 0; i < data->field_count; i++) {
679 struct audit_field *f = &krule->fields[i];
680
681 data->fields[i] = f->type;
682 data->fieldflags[i] = f->op;
683 switch(f->type) {
684 case AUDIT_SUBJ_USER:
685 case AUDIT_SUBJ_ROLE:
686 case AUDIT_SUBJ_TYPE:
687 case AUDIT_SUBJ_SEN:
688 case AUDIT_SUBJ_CLR:
689 case AUDIT_OBJ_USER:
690 case AUDIT_OBJ_ROLE:
691 case AUDIT_OBJ_TYPE:
692 case AUDIT_OBJ_LEV_LOW:
693 case AUDIT_OBJ_LEV_HIGH:
694 data->buflen += data->values[i] =
695 audit_pack_string(&bufp, f->se_str);
696 break;
697 case AUDIT_WATCH:
698 data->buflen += data->values[i] =
699 audit_pack_string(&bufp, krule->watch->path);
700 break;
701 case AUDIT_FILTERKEY:
702 data->buflen += data->values[i] =
703 audit_pack_string(&bufp, krule->filterkey);
704 break;
705 default:
706 data->values[i] = f->val;
707 }
708 }
709 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
710
711 return data;
712 }
713
714 /* Compare two rules in kernel format. Considered success if rules
715 * don't match. */
716 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
717 {
718 int i;
719
720 if (a->flags != b->flags ||
721 a->listnr != b->listnr ||
722 a->action != b->action ||
723 a->field_count != b->field_count)
724 return 1;
725
726 for (i = 0; i < a->field_count; i++) {
727 if (a->fields[i].type != b->fields[i].type ||
728 a->fields[i].op != b->fields[i].op)
729 return 1;
730
731 switch(a->fields[i].type) {
732 case AUDIT_SUBJ_USER:
733 case AUDIT_SUBJ_ROLE:
734 case AUDIT_SUBJ_TYPE:
735 case AUDIT_SUBJ_SEN:
736 case AUDIT_SUBJ_CLR:
737 case AUDIT_OBJ_USER:
738 case AUDIT_OBJ_ROLE:
739 case AUDIT_OBJ_TYPE:
740 case AUDIT_OBJ_LEV_LOW:
741 case AUDIT_OBJ_LEV_HIGH:
742 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
743 return 1;
744 break;
745 case AUDIT_WATCH:
746 if (strcmp(a->watch->path, b->watch->path))
747 return 1;
748 break;
749 case AUDIT_FILTERKEY:
750 /* both filterkeys exist based on above type compare */
751 if (strcmp(a->filterkey, b->filterkey))
752 return 1;
753 break;
754 default:
755 if (a->fields[i].val != b->fields[i].val)
756 return 1;
757 }
758 }
759
760 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
761 if (a->mask[i] != b->mask[i])
762 return 1;
763
764 return 0;
765 }
766
767 /* Duplicate the given audit watch. The new watch's rules list is initialized
768 * to an empty list and wlist is undefined. */
769 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
770 {
771 char *path;
772 struct audit_watch *new;
773
774 path = kstrdup(old->path, GFP_KERNEL);
775 if (unlikely(!path))
776 return ERR_PTR(-ENOMEM);
777
778 new = audit_init_watch(path);
779 if (unlikely(IS_ERR(new))) {
780 kfree(path);
781 goto out;
782 }
783
784 new->dev = old->dev;
785 new->ino = old->ino;
786 get_inotify_watch(&old->parent->wdata);
787 new->parent = old->parent;
788
789 out:
790 return new;
791 }
792
793 /* Duplicate selinux field information. The se_rule is opaque, so must be
794 * re-initialized. */
795 static inline int audit_dupe_selinux_field(struct audit_field *df,
796 struct audit_field *sf)
797 {
798 int ret = 0;
799 char *se_str;
800
801 /* our own copy of se_str */
802 se_str = kstrdup(sf->se_str, GFP_KERNEL);
803 if (unlikely(!se_str))
804 return -ENOMEM;
805 df->se_str = se_str;
806
807 /* our own (refreshed) copy of se_rule */
808 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
809 &df->se_rule);
810 /* Keep currently invalid fields around in case they
811 * become valid after a policy reload. */
812 if (ret == -EINVAL) {
813 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
814 "invalid\n", df->se_str);
815 ret = 0;
816 }
817
818 return ret;
819 }
820
821 /* Duplicate an audit rule. This will be a deep copy with the exception
822 * of the watch - that pointer is carried over. The selinux specific fields
823 * will be updated in the copy. The point is to be able to replace the old
824 * rule with the new rule in the filterlist, then free the old rule.
825 * The rlist element is undefined; list manipulations are handled apart from
826 * the initial copy. */
827 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
828 struct audit_watch *watch)
829 {
830 u32 fcount = old->field_count;
831 struct audit_entry *entry;
832 struct audit_krule *new;
833 char *fk;
834 int i, err = 0;
835
836 entry = audit_init_entry(fcount);
837 if (unlikely(!entry))
838 return ERR_PTR(-ENOMEM);
839
840 new = &entry->rule;
841 new->vers_ops = old->vers_ops;
842 new->flags = old->flags;
843 new->listnr = old->listnr;
844 new->action = old->action;
845 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
846 new->mask[i] = old->mask[i];
847 new->buflen = old->buflen;
848 new->inode_f = old->inode_f;
849 new->watch = NULL;
850 new->field_count = old->field_count;
851 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
852
853 /* deep copy this information, updating the se_rule fields, because
854 * the originals will all be freed when the old rule is freed. */
855 for (i = 0; i < fcount; i++) {
856 switch (new->fields[i].type) {
857 case AUDIT_SUBJ_USER:
858 case AUDIT_SUBJ_ROLE:
859 case AUDIT_SUBJ_TYPE:
860 case AUDIT_SUBJ_SEN:
861 case AUDIT_SUBJ_CLR:
862 case AUDIT_OBJ_USER:
863 case AUDIT_OBJ_ROLE:
864 case AUDIT_OBJ_TYPE:
865 case AUDIT_OBJ_LEV_LOW:
866 case AUDIT_OBJ_LEV_HIGH:
867 err = audit_dupe_selinux_field(&new->fields[i],
868 &old->fields[i]);
869 break;
870 case AUDIT_FILTERKEY:
871 fk = kstrdup(old->filterkey, GFP_KERNEL);
872 if (unlikely(!fk))
873 err = -ENOMEM;
874 else
875 new->filterkey = fk;
876 }
877 if (err) {
878 audit_free_rule(entry);
879 return ERR_PTR(err);
880 }
881 }
882
883 if (watch) {
884 audit_get_watch(watch);
885 new->watch = watch;
886 }
887
888 return entry;
889 }
890
891 /* Update inode info in audit rules based on filesystem event. */
892 static void audit_update_watch(struct audit_parent *parent,
893 const char *dname, dev_t dev,
894 unsigned long ino, unsigned invalidating)
895 {
896 struct audit_watch *owatch, *nwatch, *nextw;
897 struct audit_krule *r, *nextr;
898 struct audit_entry *oentry, *nentry;
899 struct audit_buffer *ab;
900
901 mutex_lock(&audit_filter_mutex);
902 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
903 if (audit_compare_dname_path(dname, owatch->path, NULL))
904 continue;
905
906 /* If the update involves invalidating rules, do the inode-based
907 * filtering now, so we don't omit records. */
908 if (invalidating &&
909 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
910 audit_set_auditable(current->audit_context);
911
912 nwatch = audit_dupe_watch(owatch);
913 if (unlikely(IS_ERR(nwatch))) {
914 mutex_unlock(&audit_filter_mutex);
915 audit_panic("error updating watch, skipping");
916 return;
917 }
918 nwatch->dev = dev;
919 nwatch->ino = ino;
920
921 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
922
923 oentry = container_of(r, struct audit_entry, rule);
924 list_del(&oentry->rule.rlist);
925 list_del_rcu(&oentry->list);
926
927 nentry = audit_dupe_rule(&oentry->rule, nwatch);
928 if (unlikely(IS_ERR(nentry)))
929 audit_panic("error updating watch, removing");
930 else {
931 int h = audit_hash_ino((u32)ino);
932 list_add(&nentry->rule.rlist, &nwatch->rules);
933 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
934 }
935
936 call_rcu(&oentry->rcu, audit_free_rule_rcu);
937 }
938
939 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
940 audit_log_format(ab, "audit updated rules specifying path=");
941 audit_log_untrustedstring(ab, owatch->path);
942 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
943 audit_log_end(ab);
944
945 audit_remove_watch(owatch);
946 goto add_watch_to_parent; /* event applies to a single watch */
947 }
948 mutex_unlock(&audit_filter_mutex);
949 return;
950
951 add_watch_to_parent:
952 list_add(&nwatch->wlist, &parent->watches);
953 mutex_unlock(&audit_filter_mutex);
954 return;
955 }
956
957 /* Remove all watches & rules associated with a parent that is going away. */
958 static void audit_remove_parent_watches(struct audit_parent *parent)
959 {
960 struct audit_watch *w, *nextw;
961 struct audit_krule *r, *nextr;
962 struct audit_entry *e;
963 struct audit_buffer *ab;
964
965 mutex_lock(&audit_filter_mutex);
966 parent->flags |= AUDIT_PARENT_INVALID;
967 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
968 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
969 e = container_of(r, struct audit_entry, rule);
970
971 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
972 audit_log_format(ab, "audit implicitly removed rule path=");
973 audit_log_untrustedstring(ab, w->path);
974 if (r->filterkey) {
975 audit_log_format(ab, " key=");
976 audit_log_untrustedstring(ab, r->filterkey);
977 } else
978 audit_log_format(ab, " key=(null)");
979 audit_log_format(ab, " list=%d", r->listnr);
980 audit_log_end(ab);
981
982 list_del(&r->rlist);
983 list_del_rcu(&e->list);
984 call_rcu(&e->rcu, audit_free_rule_rcu);
985 }
986 audit_remove_watch(w);
987 }
988 mutex_unlock(&audit_filter_mutex);
989 }
990
991 /* Unregister inotify watches for parents on in_list.
992 * Generates an IN_IGNORED event. */
993 static void audit_inotify_unregister(struct list_head *in_list)
994 {
995 struct audit_parent *p, *n;
996
997 list_for_each_entry_safe(p, n, in_list, ilist) {
998 list_del(&p->ilist);
999 inotify_rm_watch(audit_ih, &p->wdata);
1000 /* the put matching the get in audit_do_del_rule() */
1001 put_inotify_watch(&p->wdata);
1002 }
1003 }
1004
1005 /* Find an existing audit rule.
1006 * Caller must hold audit_filter_mutex to prevent stale rule data. */
1007 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
1008 struct list_head *list)
1009 {
1010 struct audit_entry *e, *found = NULL;
1011 int h;
1012
1013 if (entry->rule.watch) {
1014 /* we don't know the inode number, so must walk entire hash */
1015 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
1016 list = &audit_inode_hash[h];
1017 list_for_each_entry(e, list, list)
1018 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1019 found = e;
1020 goto out;
1021 }
1022 }
1023 goto out;
1024 }
1025
1026 list_for_each_entry(e, list, list)
1027 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1028 found = e;
1029 goto out;
1030 }
1031
1032 out:
1033 return found;
1034 }
1035
1036 /* Get path information necessary for adding watches. */
1037 static int audit_get_nd(char *path, struct nameidata **ndp,
1038 struct nameidata **ndw)
1039 {
1040 struct nameidata *ndparent, *ndwatch;
1041 int err;
1042
1043 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1044 if (unlikely(!ndparent))
1045 return -ENOMEM;
1046
1047 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1048 if (unlikely(!ndwatch)) {
1049 kfree(ndparent);
1050 return -ENOMEM;
1051 }
1052
1053 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1054 if (err) {
1055 kfree(ndparent);
1056 kfree(ndwatch);
1057 return err;
1058 }
1059
1060 err = path_lookup(path, 0, ndwatch);
1061 if (err) {
1062 kfree(ndwatch);
1063 ndwatch = NULL;
1064 }
1065
1066 *ndp = ndparent;
1067 *ndw = ndwatch;
1068
1069 return 0;
1070 }
1071
1072 /* Release resources used for watch path information. */
1073 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1074 {
1075 if (ndp) {
1076 path_release(ndp);
1077 kfree(ndp);
1078 }
1079 if (ndw) {
1080 path_release(ndw);
1081 kfree(ndw);
1082 }
1083 }
1084
1085 /* Associate the given rule with an existing parent inotify_watch.
1086 * Caller must hold audit_filter_mutex. */
1087 static void audit_add_to_parent(struct audit_krule *krule,
1088 struct audit_parent *parent)
1089 {
1090 struct audit_watch *w, *watch = krule->watch;
1091 int watch_found = 0;
1092
1093 list_for_each_entry(w, &parent->watches, wlist) {
1094 if (strcmp(watch->path, w->path))
1095 continue;
1096
1097 watch_found = 1;
1098
1099 /* put krule's and initial refs to temporary watch */
1100 audit_put_watch(watch);
1101 audit_put_watch(watch);
1102
1103 audit_get_watch(w);
1104 krule->watch = watch = w;
1105 break;
1106 }
1107
1108 if (!watch_found) {
1109 get_inotify_watch(&parent->wdata);
1110 watch->parent = parent;
1111
1112 list_add(&watch->wlist, &parent->watches);
1113 }
1114 list_add(&krule->rlist, &watch->rules);
1115 }
1116
1117 /* Find a matching watch entry, or add this one.
1118 * Caller must hold audit_filter_mutex. */
1119 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1120 struct nameidata *ndw)
1121 {
1122 struct audit_watch *watch = krule->watch;
1123 struct inotify_watch *i_watch;
1124 struct audit_parent *parent;
1125 int ret = 0;
1126
1127 /* update watch filter fields */
1128 if (ndw) {
1129 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1130 watch->ino = ndw->dentry->d_inode->i_ino;
1131 }
1132
1133 /* The audit_filter_mutex must not be held during inotify calls because
1134 * we hold it during inotify event callback processing. If an existing
1135 * inotify watch is found, inotify_find_watch() grabs a reference before
1136 * returning.
1137 */
1138 mutex_unlock(&audit_filter_mutex);
1139
1140 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1141 parent = audit_init_parent(ndp);
1142 if (IS_ERR(parent)) {
1143 /* caller expects mutex locked */
1144 mutex_lock(&audit_filter_mutex);
1145 return PTR_ERR(parent);
1146 }
1147 } else
1148 parent = container_of(i_watch, struct audit_parent, wdata);
1149
1150 mutex_lock(&audit_filter_mutex);
1151
1152 /* parent was moved before we took audit_filter_mutex */
1153 if (parent->flags & AUDIT_PARENT_INVALID)
1154 ret = -ENOENT;
1155 else
1156 audit_add_to_parent(krule, parent);
1157
1158 /* match get in audit_init_parent or inotify_find_watch */
1159 put_inotify_watch(&parent->wdata);
1160 return ret;
1161 }
1162
1163 /* Add rule to given filterlist if not a duplicate. */
1164 static inline int audit_add_rule(struct audit_entry *entry,
1165 struct list_head *list)
1166 {
1167 struct audit_entry *e;
1168 struct audit_field *inode_f = entry->rule.inode_f;
1169 struct audit_watch *watch = entry->rule.watch;
1170 struct nameidata *ndp, *ndw;
1171 int h, err, putnd_needed = 0;
1172 #ifdef CONFIG_AUDITSYSCALL
1173 int dont_count = 0;
1174
1175 /* If either of these, don't count towards total */
1176 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1177 entry->rule.listnr == AUDIT_FILTER_TYPE)
1178 dont_count = 1;
1179 #endif
1180
1181 if (inode_f) {
1182 h = audit_hash_ino(inode_f->val);
1183 list = &audit_inode_hash[h];
1184 }
1185
1186 mutex_lock(&audit_filter_mutex);
1187 e = audit_find_rule(entry, list);
1188 mutex_unlock(&audit_filter_mutex);
1189 if (e) {
1190 err = -EEXIST;
1191 goto error;
1192 }
1193
1194 /* Avoid calling path_lookup under audit_filter_mutex. */
1195 if (watch) {
1196 err = audit_get_nd(watch->path, &ndp, &ndw);
1197 if (err)
1198 goto error;
1199 putnd_needed = 1;
1200 }
1201
1202 mutex_lock(&audit_filter_mutex);
1203 if (watch) {
1204 /* audit_filter_mutex is dropped and re-taken during this call */
1205 err = audit_add_watch(&entry->rule, ndp, ndw);
1206 if (err) {
1207 mutex_unlock(&audit_filter_mutex);
1208 goto error;
1209 }
1210 h = audit_hash_ino((u32)watch->ino);
1211 list = &audit_inode_hash[h];
1212 }
1213
1214 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1215 list_add_rcu(&entry->list, list);
1216 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1217 } else {
1218 list_add_tail_rcu(&entry->list, list);
1219 }
1220 #ifdef CONFIG_AUDITSYSCALL
1221 if (!dont_count)
1222 audit_n_rules++;
1223 #endif
1224 mutex_unlock(&audit_filter_mutex);
1225
1226 if (putnd_needed)
1227 audit_put_nd(ndp, ndw);
1228
1229 return 0;
1230
1231 error:
1232 if (putnd_needed)
1233 audit_put_nd(ndp, ndw);
1234 if (watch)
1235 audit_put_watch(watch); /* tmp watch, matches initial get */
1236 return err;
1237 }
1238
1239 /* Remove an existing rule from filterlist. */
1240 static inline int audit_del_rule(struct audit_entry *entry,
1241 struct list_head *list)
1242 {
1243 struct audit_entry *e;
1244 struct audit_field *inode_f = entry->rule.inode_f;
1245 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1246 LIST_HEAD(inotify_list);
1247 int h, ret = 0;
1248 #ifdef CONFIG_AUDITSYSCALL
1249 int dont_count = 0;
1250
1251 /* If either of these, don't count towards total */
1252 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1253 entry->rule.listnr == AUDIT_FILTER_TYPE)
1254 dont_count = 1;
1255 #endif
1256
1257 if (inode_f) {
1258 h = audit_hash_ino(inode_f->val);
1259 list = &audit_inode_hash[h];
1260 }
1261
1262 mutex_lock(&audit_filter_mutex);
1263 e = audit_find_rule(entry, list);
1264 if (!e) {
1265 mutex_unlock(&audit_filter_mutex);
1266 ret = -ENOENT;
1267 goto out;
1268 }
1269
1270 watch = e->rule.watch;
1271 if (watch) {
1272 struct audit_parent *parent = watch->parent;
1273
1274 list_del(&e->rule.rlist);
1275
1276 if (list_empty(&watch->rules)) {
1277 audit_remove_watch(watch);
1278
1279 if (list_empty(&parent->watches)) {
1280 /* Put parent on the inotify un-registration
1281 * list. Grab a reference before releasing
1282 * audit_filter_mutex, to be released in
1283 * audit_inotify_unregister(). */
1284 list_add(&parent->ilist, &inotify_list);
1285 get_inotify_watch(&parent->wdata);
1286 }
1287 }
1288 }
1289
1290 list_del_rcu(&e->list);
1291 call_rcu(&e->rcu, audit_free_rule_rcu);
1292
1293 #ifdef CONFIG_AUDITSYSCALL
1294 if (!dont_count)
1295 audit_n_rules--;
1296 #endif
1297 mutex_unlock(&audit_filter_mutex);
1298
1299 if (!list_empty(&inotify_list))
1300 audit_inotify_unregister(&inotify_list);
1301
1302 out:
1303 if (tmp_watch)
1304 audit_put_watch(tmp_watch); /* match initial get */
1305
1306 return ret;
1307 }
1308
1309 /* List rules using struct audit_rule. Exists for backward
1310 * compatibility with userspace. */
1311 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1312 {
1313 struct sk_buff *skb;
1314 struct audit_entry *entry;
1315 int i;
1316
1317 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1318 * iterator to sync with list writers. */
1319 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1320 list_for_each_entry(entry, &audit_filter_list[i], list) {
1321 struct audit_rule *rule;
1322
1323 rule = audit_krule_to_rule(&entry->rule);
1324 if (unlikely(!rule))
1325 break;
1326 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1327 rule, sizeof(*rule));
1328 if (skb)
1329 skb_queue_tail(q, skb);
1330 kfree(rule);
1331 }
1332 }
1333 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1334 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1335 struct audit_rule *rule;
1336
1337 rule = audit_krule_to_rule(&entry->rule);
1338 if (unlikely(!rule))
1339 break;
1340 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1341 rule, sizeof(*rule));
1342 if (skb)
1343 skb_queue_tail(q, skb);
1344 kfree(rule);
1345 }
1346 }
1347 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1348 if (skb)
1349 skb_queue_tail(q, skb);
1350 }
1351
1352 /* List rules using struct audit_rule_data. */
1353 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1354 {
1355 struct sk_buff *skb;
1356 struct audit_entry *e;
1357 int i;
1358
1359 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1360 * iterator to sync with list writers. */
1361 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1362 list_for_each_entry(e, &audit_filter_list[i], list) {
1363 struct audit_rule_data *data;
1364
1365 data = audit_krule_to_data(&e->rule);
1366 if (unlikely(!data))
1367 break;
1368 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1369 data, sizeof(*data) + data->buflen);
1370 if (skb)
1371 skb_queue_tail(q, skb);
1372 kfree(data);
1373 }
1374 }
1375 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1376 list_for_each_entry(e, &audit_inode_hash[i], list) {
1377 struct audit_rule_data *data;
1378
1379 data = audit_krule_to_data(&e->rule);
1380 if (unlikely(!data))
1381 break;
1382 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1383 data, sizeof(*data) + data->buflen);
1384 if (skb)
1385 skb_queue_tail(q, skb);
1386 kfree(data);
1387 }
1388 }
1389 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1390 if (skb)
1391 skb_queue_tail(q, skb);
1392 }
1393
1394 /* Log rule additions and removals */
1395 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1396 struct audit_krule *rule, int res)
1397 {
1398 struct audit_buffer *ab;
1399
1400 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1401 if (!ab)
1402 return;
1403 audit_log_format(ab, "auid=%u", loginuid);
1404 if (sid) {
1405 char *ctx = NULL;
1406 u32 len;
1407 if (selinux_sid_to_string(sid, &ctx, &len))
1408 audit_log_format(ab, " ssid=%u", sid);
1409 else
1410 audit_log_format(ab, " subj=%s", ctx);
1411 kfree(ctx);
1412 }
1413 audit_log_format(ab, " %s rule key=", action);
1414 if (rule->filterkey)
1415 audit_log_untrustedstring(ab, rule->filterkey);
1416 else
1417 audit_log_format(ab, "(null)");
1418 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1419 audit_log_end(ab);
1420 }
1421
1422 /**
1423 * audit_receive_filter - apply all rules to the specified message type
1424 * @type: audit message type
1425 * @pid: target pid for netlink audit messages
1426 * @uid: target uid for netlink audit messages
1427 * @seq: netlink audit message sequence (serial) number
1428 * @data: payload data
1429 * @datasz: size of payload data
1430 * @loginuid: loginuid of sender
1431 * @sid: SE Linux Security ID of sender
1432 */
1433 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1434 size_t datasz, uid_t loginuid, u32 sid)
1435 {
1436 struct task_struct *tsk;
1437 struct audit_netlink_list *dest;
1438 int err = 0;
1439 struct audit_entry *entry;
1440
1441 switch (type) {
1442 case AUDIT_LIST:
1443 case AUDIT_LIST_RULES:
1444 /* We can't just spew out the rules here because we might fill
1445 * the available socket buffer space and deadlock waiting for
1446 * auditctl to read from it... which isn't ever going to
1447 * happen if we're actually running in the context of auditctl
1448 * trying to _send_ the stuff */
1449
1450 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1451 if (!dest)
1452 return -ENOMEM;
1453 dest->pid = pid;
1454 skb_queue_head_init(&dest->q);
1455
1456 mutex_lock(&audit_filter_mutex);
1457 if (type == AUDIT_LIST)
1458 audit_list(pid, seq, &dest->q);
1459 else
1460 audit_list_rules(pid, seq, &dest->q);
1461 mutex_unlock(&audit_filter_mutex);
1462
1463 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1464 if (IS_ERR(tsk)) {
1465 skb_queue_purge(&dest->q);
1466 kfree(dest);
1467 err = PTR_ERR(tsk);
1468 }
1469 break;
1470 case AUDIT_ADD:
1471 case AUDIT_ADD_RULE:
1472 if (type == AUDIT_ADD)
1473 entry = audit_rule_to_entry(data);
1474 else
1475 entry = audit_data_to_entry(data, datasz);
1476 if (IS_ERR(entry))
1477 return PTR_ERR(entry);
1478
1479 err = audit_add_rule(entry,
1480 &audit_filter_list[entry->rule.listnr]);
1481 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1482
1483 if (err)
1484 audit_free_rule(entry);
1485 break;
1486 case AUDIT_DEL:
1487 case AUDIT_DEL_RULE:
1488 if (type == AUDIT_DEL)
1489 entry = audit_rule_to_entry(data);
1490 else
1491 entry = audit_data_to_entry(data, datasz);
1492 if (IS_ERR(entry))
1493 return PTR_ERR(entry);
1494
1495 err = audit_del_rule(entry,
1496 &audit_filter_list[entry->rule.listnr]);
1497 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1498 !err);
1499
1500 audit_free_rule(entry);
1501 break;
1502 default:
1503 return -EINVAL;
1504 }
1505
1506 return err;
1507 }
1508
1509 int audit_comparator(const u32 left, const u32 op, const u32 right)
1510 {
1511 switch (op) {
1512 case AUDIT_EQUAL:
1513 return (left == right);
1514 case AUDIT_NOT_EQUAL:
1515 return (left != right);
1516 case AUDIT_LESS_THAN:
1517 return (left < right);
1518 case AUDIT_LESS_THAN_OR_EQUAL:
1519 return (left <= right);
1520 case AUDIT_GREATER_THAN:
1521 return (left > right);
1522 case AUDIT_GREATER_THAN_OR_EQUAL:
1523 return (left >= right);
1524 }
1525 BUG();
1526 return 0;
1527 }
1528
1529 /* Compare given dentry name with last component in given path,
1530 * return of 0 indicates a match. */
1531 int audit_compare_dname_path(const char *dname, const char *path,
1532 int *dirlen)
1533 {
1534 int dlen, plen;
1535 const char *p;
1536
1537 if (!dname || !path)
1538 return 1;
1539
1540 dlen = strlen(dname);
1541 plen = strlen(path);
1542 if (plen < dlen)
1543 return 1;
1544
1545 /* disregard trailing slashes */
1546 p = path + plen - 1;
1547 while ((*p == '/') && (p > path))
1548 p--;
1549
1550 /* find last path component */
1551 p = p - dlen + 1;
1552 if (p < path)
1553 return 1;
1554 else if (p > path) {
1555 if (*--p != '/')
1556 return 1;
1557 else
1558 p++;
1559 }
1560
1561 /* return length of path's directory component */
1562 if (dirlen)
1563 *dirlen = p - path;
1564 return strncmp(p, dname, dlen);
1565 }
1566
1567 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1568 struct audit_krule *rule,
1569 enum audit_state *state)
1570 {
1571 int i;
1572
1573 for (i = 0; i < rule->field_count; i++) {
1574 struct audit_field *f = &rule->fields[i];
1575 int result = 0;
1576
1577 switch (f->type) {
1578 case AUDIT_PID:
1579 result = audit_comparator(cb->creds.pid, f->op, f->val);
1580 break;
1581 case AUDIT_UID:
1582 result = audit_comparator(cb->creds.uid, f->op, f->val);
1583 break;
1584 case AUDIT_GID:
1585 result = audit_comparator(cb->creds.gid, f->op, f->val);
1586 break;
1587 case AUDIT_LOGINUID:
1588 result = audit_comparator(cb->loginuid, f->op, f->val);
1589 break;
1590 }
1591
1592 if (!result)
1593 return 0;
1594 }
1595 switch (rule->action) {
1596 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1597 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1598 }
1599 return 1;
1600 }
1601
1602 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1603 {
1604 struct audit_entry *e;
1605 enum audit_state state;
1606 int ret = 1;
1607
1608 rcu_read_lock();
1609 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1610 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1611 if (state == AUDIT_DISABLED)
1612 ret = 0;
1613 break;
1614 }
1615 }
1616 rcu_read_unlock();
1617
1618 return ret; /* Audit by default */
1619 }
1620
1621 int audit_filter_type(int type)
1622 {
1623 struct audit_entry *e;
1624 int result = 0;
1625
1626 rcu_read_lock();
1627 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1628 goto unlock_and_return;
1629
1630 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1631 list) {
1632 int i;
1633 for (i = 0; i < e->rule.field_count; i++) {
1634 struct audit_field *f = &e->rule.fields[i];
1635 if (f->type == AUDIT_MSGTYPE) {
1636 result = audit_comparator(type, f->op, f->val);
1637 if (!result)
1638 break;
1639 }
1640 }
1641 if (result)
1642 goto unlock_and_return;
1643 }
1644 unlock_and_return:
1645 rcu_read_unlock();
1646 return result;
1647 }
1648
1649 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1650 are selinux fields specified in the rule, 0 otherwise. */
1651 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1652 {
1653 int i;
1654
1655 for (i = 0; i < rule->field_count; i++) {
1656 struct audit_field *f = &rule->fields[i];
1657 switch (f->type) {
1658 case AUDIT_SUBJ_USER:
1659 case AUDIT_SUBJ_ROLE:
1660 case AUDIT_SUBJ_TYPE:
1661 case AUDIT_SUBJ_SEN:
1662 case AUDIT_SUBJ_CLR:
1663 case AUDIT_OBJ_USER:
1664 case AUDIT_OBJ_ROLE:
1665 case AUDIT_OBJ_TYPE:
1666 case AUDIT_OBJ_LEV_LOW:
1667 case AUDIT_OBJ_LEV_HIGH:
1668 return 1;
1669 }
1670 }
1671
1672 return 0;
1673 }
1674
1675 /* This function will re-initialize the se_rule field of all applicable rules.
1676 * It will traverse the filter lists serarching for rules that contain selinux
1677 * specific filter fields. When such a rule is found, it is copied, the
1678 * selinux field is re-initialized, and the old rule is replaced with the
1679 * updated rule. */
1680 int selinux_audit_rule_update(void)
1681 {
1682 struct audit_entry *entry, *n, *nentry;
1683 struct audit_watch *watch;
1684 int i, err = 0;
1685
1686 /* audit_filter_mutex synchronizes the writers */
1687 mutex_lock(&audit_filter_mutex);
1688
1689 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1690 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1691 if (!audit_rule_has_selinux(&entry->rule))
1692 continue;
1693
1694 watch = entry->rule.watch;
1695 nentry = audit_dupe_rule(&entry->rule, watch);
1696 if (unlikely(IS_ERR(nentry))) {
1697 /* save the first error encountered for the
1698 * return value */
1699 if (!err)
1700 err = PTR_ERR(nentry);
1701 audit_panic("error updating selinux filters");
1702 if (watch)
1703 list_del(&entry->rule.rlist);
1704 list_del_rcu(&entry->list);
1705 } else {
1706 if (watch) {
1707 list_add(&nentry->rule.rlist,
1708 &watch->rules);
1709 list_del(&entry->rule.rlist);
1710 }
1711 list_replace_rcu(&entry->list, &nentry->list);
1712 }
1713 call_rcu(&entry->rcu, audit_free_rule_rcu);
1714 }
1715 }
1716
1717 mutex_unlock(&audit_filter_mutex);
1718
1719 return err;
1720 }
1721
1722 /* Update watch data in audit rules based on inotify events. */
1723 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1724 u32 cookie, const char *dname, struct inode *inode)
1725 {
1726 struct audit_parent *parent;
1727
1728 parent = container_of(i_watch, struct audit_parent, wdata);
1729
1730 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1731 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1732 inode->i_ino, 0);
1733 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1734 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1735 /* inotify automatically removes the watch and sends IN_IGNORED */
1736 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1737 audit_remove_parent_watches(parent);
1738 /* inotify does not remove the watch, so remove it manually */
1739 else if(mask & IN_MOVE_SELF) {
1740 audit_remove_parent_watches(parent);
1741 inotify_remove_watch_locked(audit_ih, i_watch);
1742 } else if (mask & IN_IGNORED)
1743 put_inotify_watch(i_watch);
1744 }
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