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USB: Add URB_FREE_BUFFER flag and the logic behind it
[linux-2.6/openmoko-kernel.git] / kernel / auditfilter.c
blobce61f423542c18b1a691d73f4f5d7cc4ca94ec75
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 #ifdef CONFIG_AUDITSYSCALL
315 static inline int audit_match_class_bits(int class, u32 *mask)
316 {
317 int i;
318
319 if (classes[class]) {
320 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
321 if (mask[i] & classes[class][i])
322 return 0;
323 }
324 return 1;
325 }
326
327 static int audit_match_signal(struct audit_entry *entry)
328 {
329 struct audit_field *arch = entry->rule.arch_f;
330
331 if (!arch) {
332 /* When arch is unspecified, we must check both masks on biarch
333 * as syscall number alone is ambiguous. */
334 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
335 entry->rule.mask) &&
336 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
337 entry->rule.mask));
338 }
339
340 switch(audit_classify_arch(arch->val)) {
341 case 0: /* native */
342 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
343 entry->rule.mask));
344 case 1: /* 32bit on biarch */
345 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
346 entry->rule.mask));
347 default:
348 return 1;
349 }
350 }
351 #endif
352
353 /* Common user-space to kernel rule translation. */
354 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
355 {
356 unsigned listnr;
357 struct audit_entry *entry;
358 int i, err;
359
360 err = -EINVAL;
361 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
362 switch(listnr) {
363 default:
364 goto exit_err;
365 case AUDIT_FILTER_USER:
366 case AUDIT_FILTER_TYPE:
367 #ifdef CONFIG_AUDITSYSCALL
368 case AUDIT_FILTER_ENTRY:
369 case AUDIT_FILTER_EXIT:
370 case AUDIT_FILTER_TASK:
371 #endif
372 ;
373 }
374 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
375 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
376 goto exit_err;
377 }
378 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
379 goto exit_err;
380 if (rule->field_count > AUDIT_MAX_FIELDS)
381 goto exit_err;
382
383 err = -ENOMEM;
384 entry = audit_init_entry(rule->field_count);
385 if (!entry)
386 goto exit_err;
387
388 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
389 entry->rule.listnr = listnr;
390 entry->rule.action = rule->action;
391 entry->rule.field_count = rule->field_count;
392
393 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
394 entry->rule.mask[i] = rule->mask[i];
395
396 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
397 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
398 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
399 __u32 *class;
400
401 if (!(*p & AUDIT_BIT(bit)))
402 continue;
403 *p &= ~AUDIT_BIT(bit);
404 class = classes[i];
405 if (class) {
406 int j;
407 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
408 entry->rule.mask[j] |= class[j];
409 }
410 }
411
412 return entry;
413
414 exit_err:
415 return ERR_PTR(err);
416 }
417
418 /* Translate struct audit_rule to kernel's rule respresentation.
419 * Exists for backward compatibility with userspace. */
420 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
421 {
422 struct audit_entry *entry;
423 struct audit_field *f;
424 int err = 0;
425 int i;
426
427 entry = audit_to_entry_common(rule);
428 if (IS_ERR(entry))
429 goto exit_nofree;
430
431 for (i = 0; i < rule->field_count; i++) {
432 struct audit_field *f = &entry->rule.fields[i];
433
434 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
435 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
436 f->val = rule->values[i];
437
438 err = -EINVAL;
439 switch(f->type) {
440 default:
441 goto exit_free;
442 case AUDIT_PID:
443 case AUDIT_UID:
444 case AUDIT_EUID:
445 case AUDIT_SUID:
446 case AUDIT_FSUID:
447 case AUDIT_GID:
448 case AUDIT_EGID:
449 case AUDIT_SGID:
450 case AUDIT_FSGID:
451 case AUDIT_LOGINUID:
452 case AUDIT_PERS:
453 case AUDIT_MSGTYPE:
454 case AUDIT_PPID:
455 case AUDIT_DEVMAJOR:
456 case AUDIT_DEVMINOR:
457 case AUDIT_EXIT:
458 case AUDIT_SUCCESS:
459 case AUDIT_ARG0:
460 case AUDIT_ARG1:
461 case AUDIT_ARG2:
462 case AUDIT_ARG3:
463 break;
464 /* arch is only allowed to be = or != */
465 case AUDIT_ARCH:
466 if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL)
467 && (f->op != AUDIT_NEGATE) && (f->op)) {
468 err = -EINVAL;
469 goto exit_free;
470 }
471 entry->rule.arch_f = f;
472 break;
473 case AUDIT_PERM:
474 if (f->val & ~15)
475 goto exit_free;
476 break;
477 case AUDIT_INODE:
478 err = audit_to_inode(&entry->rule, f);
479 if (err)
480 goto exit_free;
481 break;
482 }
483
484 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
485
486 /* Support for legacy operators where
487 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
488 if (f->op & AUDIT_NEGATE)
489 f->op = AUDIT_NOT_EQUAL;
490 else if (!f->op)
491 f->op = AUDIT_EQUAL;
492 else if (f->op == AUDIT_OPERATORS) {
493 err = -EINVAL;
494 goto exit_free;
495 }
496 }
497
498 f = entry->rule.inode_f;
499 if (f) {
500 switch(f->op) {
501 case AUDIT_NOT_EQUAL:
502 entry->rule.inode_f = NULL;
503 case AUDIT_EQUAL:
504 break;
505 default:
506 err = -EINVAL;
507 goto exit_free;
508 }
509 }
510
511 exit_nofree:
512 return entry;
513
514 exit_free:
515 audit_free_rule(entry);
516 return ERR_PTR(err);
517 }
518
519 /* Translate struct audit_rule_data to kernel's rule respresentation. */
520 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
521 size_t datasz)
522 {
523 int err = 0;
524 struct audit_entry *entry;
525 struct audit_field *f;
526 void *bufp;
527 size_t remain = datasz - sizeof(struct audit_rule_data);
528 int i;
529 char *str;
530
531 entry = audit_to_entry_common((struct audit_rule *)data);
532 if (IS_ERR(entry))
533 goto exit_nofree;
534
535 bufp = data->buf;
536 entry->rule.vers_ops = 2;
537 for (i = 0; i < data->field_count; i++) {
538 struct audit_field *f = &entry->rule.fields[i];
539
540 err = -EINVAL;
541 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
542 data->fieldflags[i] & ~AUDIT_OPERATORS)
543 goto exit_free;
544
545 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
546 f->type = data->fields[i];
547 f->val = data->values[i];
548 f->se_str = NULL;
549 f->se_rule = NULL;
550 switch(f->type) {
551 case AUDIT_PID:
552 case AUDIT_UID:
553 case AUDIT_EUID:
554 case AUDIT_SUID:
555 case AUDIT_FSUID:
556 case AUDIT_GID:
557 case AUDIT_EGID:
558 case AUDIT_SGID:
559 case AUDIT_FSGID:
560 case AUDIT_LOGINUID:
561 case AUDIT_PERS:
562 case AUDIT_MSGTYPE:
563 case AUDIT_PPID:
564 case AUDIT_DEVMAJOR:
565 case AUDIT_DEVMINOR:
566 case AUDIT_EXIT:
567 case AUDIT_SUCCESS:
568 case AUDIT_ARG0:
569 case AUDIT_ARG1:
570 case AUDIT_ARG2:
571 case AUDIT_ARG3:
572 break;
573 case AUDIT_ARCH:
574 entry->rule.arch_f = f;
575 break;
576 case AUDIT_SUBJ_USER:
577 case AUDIT_SUBJ_ROLE:
578 case AUDIT_SUBJ_TYPE:
579 case AUDIT_SUBJ_SEN:
580 case AUDIT_SUBJ_CLR:
581 case AUDIT_OBJ_USER:
582 case AUDIT_OBJ_ROLE:
583 case AUDIT_OBJ_TYPE:
584 case AUDIT_OBJ_LEV_LOW:
585 case AUDIT_OBJ_LEV_HIGH:
586 str = audit_unpack_string(&bufp, &remain, f->val);
587 if (IS_ERR(str))
588 goto exit_free;
589 entry->rule.buflen += f->val;
590
591 err = selinux_audit_rule_init(f->type, f->op, str,
592 &f->se_rule);
593 /* Keep currently invalid fields around in case they
594 * become valid after a policy reload. */
595 if (err == -EINVAL) {
596 printk(KERN_WARNING "audit rule for selinux "
597 "\'%s\' is invalid\n", str);
598 err = 0;
599 }
600 if (err) {
601 kfree(str);
602 goto exit_free;
603 } else
604 f->se_str = str;
605 break;
606 case AUDIT_WATCH:
607 str = audit_unpack_string(&bufp, &remain, f->val);
608 if (IS_ERR(str))
609 goto exit_free;
610 entry->rule.buflen += f->val;
611
612 err = audit_to_watch(&entry->rule, str, f->val, f->op);
613 if (err) {
614 kfree(str);
615 goto exit_free;
616 }
617 break;
618 case AUDIT_INODE:
619 err = audit_to_inode(&entry->rule, f);
620 if (err)
621 goto exit_free;
622 break;
623 case AUDIT_FILTERKEY:
624 err = -EINVAL;
625 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
626 goto exit_free;
627 str = audit_unpack_string(&bufp, &remain, f->val);
628 if (IS_ERR(str))
629 goto exit_free;
630 entry->rule.buflen += f->val;
631 entry->rule.filterkey = str;
632 break;
633 case AUDIT_PERM:
634 if (f->val & ~15)
635 goto exit_free;
636 break;
637 default:
638 goto exit_free;
639 }
640 }
641
642 f = entry->rule.inode_f;
643 if (f) {
644 switch(f->op) {
645 case AUDIT_NOT_EQUAL:
646 entry->rule.inode_f = NULL;
647 case AUDIT_EQUAL:
648 break;
649 default:
650 err = -EINVAL;
651 goto exit_free;
652 }
653 }
654
655 exit_nofree:
656 return entry;
657
658 exit_free:
659 audit_free_rule(entry);
660 return ERR_PTR(err);
661 }
662
663 /* Pack a filter field's string representation into data block. */
664 static inline size_t audit_pack_string(void **bufp, char *str)
665 {
666 size_t len = strlen(str);
667
668 memcpy(*bufp, str, len);
669 *bufp += len;
670
671 return len;
672 }
673
674 /* Translate kernel rule respresentation to struct audit_rule.
675 * Exists for backward compatibility with userspace. */
676 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
677 {
678 struct audit_rule *rule;
679 int i;
680
681 rule = kzalloc(sizeof(*rule), GFP_KERNEL);
682 if (unlikely(!rule))
683 return NULL;
684
685 rule->flags = krule->flags | krule->listnr;
686 rule->action = krule->action;
687 rule->field_count = krule->field_count;
688 for (i = 0; i < rule->field_count; i++) {
689 rule->values[i] = krule->fields[i].val;
690 rule->fields[i] = krule->fields[i].type;
691
692 if (krule->vers_ops == 1) {
693 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
694 rule->fields[i] |= AUDIT_NEGATE;
695 } else {
696 rule->fields[i] |= krule->fields[i].op;
697 }
698 }
699 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
700
701 return rule;
702 }
703
704 /* Translate kernel rule respresentation to struct audit_rule_data. */
705 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
706 {
707 struct audit_rule_data *data;
708 void *bufp;
709 int i;
710
711 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
712 if (unlikely(!data))
713 return NULL;
714 memset(data, 0, sizeof(*data));
715
716 data->flags = krule->flags | krule->listnr;
717 data->action = krule->action;
718 data->field_count = krule->field_count;
719 bufp = data->buf;
720 for (i = 0; i < data->field_count; i++) {
721 struct audit_field *f = &krule->fields[i];
722
723 data->fields[i] = f->type;
724 data->fieldflags[i] = f->op;
725 switch(f->type) {
726 case AUDIT_SUBJ_USER:
727 case AUDIT_SUBJ_ROLE:
728 case AUDIT_SUBJ_TYPE:
729 case AUDIT_SUBJ_SEN:
730 case AUDIT_SUBJ_CLR:
731 case AUDIT_OBJ_USER:
732 case AUDIT_OBJ_ROLE:
733 case AUDIT_OBJ_TYPE:
734 case AUDIT_OBJ_LEV_LOW:
735 case AUDIT_OBJ_LEV_HIGH:
736 data->buflen += data->values[i] =
737 audit_pack_string(&bufp, f->se_str);
738 break;
739 case AUDIT_WATCH:
740 data->buflen += data->values[i] =
741 audit_pack_string(&bufp, krule->watch->path);
742 break;
743 case AUDIT_FILTERKEY:
744 data->buflen += data->values[i] =
745 audit_pack_string(&bufp, krule->filterkey);
746 break;
747 default:
748 data->values[i] = f->val;
749 }
750 }
751 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
752
753 return data;
754 }
755
756 /* Compare two rules in kernel format. Considered success if rules
757 * don't match. */
758 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
759 {
760 int i;
761
762 if (a->flags != b->flags ||
763 a->listnr != b->listnr ||
764 a->action != b->action ||
765 a->field_count != b->field_count)
766 return 1;
767
768 for (i = 0; i < a->field_count; i++) {
769 if (a->fields[i].type != b->fields[i].type ||
770 a->fields[i].op != b->fields[i].op)
771 return 1;
772
773 switch(a->fields[i].type) {
774 case AUDIT_SUBJ_USER:
775 case AUDIT_SUBJ_ROLE:
776 case AUDIT_SUBJ_TYPE:
777 case AUDIT_SUBJ_SEN:
778 case AUDIT_SUBJ_CLR:
779 case AUDIT_OBJ_USER:
780 case AUDIT_OBJ_ROLE:
781 case AUDIT_OBJ_TYPE:
782 case AUDIT_OBJ_LEV_LOW:
783 case AUDIT_OBJ_LEV_HIGH:
784 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
785 return 1;
786 break;
787 case AUDIT_WATCH:
788 if (strcmp(a->watch->path, b->watch->path))
789 return 1;
790 break;
791 case AUDIT_FILTERKEY:
792 /* both filterkeys exist based on above type compare */
793 if (strcmp(a->filterkey, b->filterkey))
794 return 1;
795 break;
796 default:
797 if (a->fields[i].val != b->fields[i].val)
798 return 1;
799 }
800 }
801
802 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
803 if (a->mask[i] != b->mask[i])
804 return 1;
805
806 return 0;
807 }
808
809 /* Duplicate the given audit watch. The new watch's rules list is initialized
810 * to an empty list and wlist is undefined. */
811 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
812 {
813 char *path;
814 struct audit_watch *new;
815
816 path = kstrdup(old->path, GFP_KERNEL);
817 if (unlikely(!path))
818 return ERR_PTR(-ENOMEM);
819
820 new = audit_init_watch(path);
821 if (unlikely(IS_ERR(new))) {
822 kfree(path);
823 goto out;
824 }
825
826 new->dev = old->dev;
827 new->ino = old->ino;
828 get_inotify_watch(&old->parent->wdata);
829 new->parent = old->parent;
830
831 out:
832 return new;
833 }
834
835 /* Duplicate selinux field information. The se_rule is opaque, so must be
836 * re-initialized. */
837 static inline int audit_dupe_selinux_field(struct audit_field *df,
838 struct audit_field *sf)
839 {
840 int ret = 0;
841 char *se_str;
842
843 /* our own copy of se_str */
844 se_str = kstrdup(sf->se_str, GFP_KERNEL);
845 if (unlikely(!se_str))
846 return -ENOMEM;
847 df->se_str = se_str;
848
849 /* our own (refreshed) copy of se_rule */
850 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
851 &df->se_rule);
852 /* Keep currently invalid fields around in case they
853 * become valid after a policy reload. */
854 if (ret == -EINVAL) {
855 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
856 "invalid\n", df->se_str);
857 ret = 0;
858 }
859
860 return ret;
861 }
862
863 /* Duplicate an audit rule. This will be a deep copy with the exception
864 * of the watch - that pointer is carried over. The selinux specific fields
865 * will be updated in the copy. The point is to be able to replace the old
866 * rule with the new rule in the filterlist, then free the old rule.
867 * The rlist element is undefined; list manipulations are handled apart from
868 * the initial copy. */
869 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
870 struct audit_watch *watch)
871 {
872 u32 fcount = old->field_count;
873 struct audit_entry *entry;
874 struct audit_krule *new;
875 char *fk;
876 int i, err = 0;
877
878 entry = audit_init_entry(fcount);
879 if (unlikely(!entry))
880 return ERR_PTR(-ENOMEM);
881
882 new = &entry->rule;
883 new->vers_ops = old->vers_ops;
884 new->flags = old->flags;
885 new->listnr = old->listnr;
886 new->action = old->action;
887 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
888 new->mask[i] = old->mask[i];
889 new->buflen = old->buflen;
890 new->inode_f = old->inode_f;
891 new->watch = NULL;
892 new->field_count = old->field_count;
893 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
894
895 /* deep copy this information, updating the se_rule fields, because
896 * the originals will all be freed when the old rule is freed. */
897 for (i = 0; i < fcount; i++) {
898 switch (new->fields[i].type) {
899 case AUDIT_SUBJ_USER:
900 case AUDIT_SUBJ_ROLE:
901 case AUDIT_SUBJ_TYPE:
902 case AUDIT_SUBJ_SEN:
903 case AUDIT_SUBJ_CLR:
904 case AUDIT_OBJ_USER:
905 case AUDIT_OBJ_ROLE:
906 case AUDIT_OBJ_TYPE:
907 case AUDIT_OBJ_LEV_LOW:
908 case AUDIT_OBJ_LEV_HIGH:
909 err = audit_dupe_selinux_field(&new->fields[i],
910 &old->fields[i]);
911 break;
912 case AUDIT_FILTERKEY:
913 fk = kstrdup(old->filterkey, GFP_KERNEL);
914 if (unlikely(!fk))
915 err = -ENOMEM;
916 else
917 new->filterkey = fk;
918 }
919 if (err) {
920 audit_free_rule(entry);
921 return ERR_PTR(err);
922 }
923 }
924
925 if (watch) {
926 audit_get_watch(watch);
927 new->watch = watch;
928 }
929
930 return entry;
931 }
932
933 /* Update inode info in audit rules based on filesystem event. */
934 static void audit_update_watch(struct audit_parent *parent,
935 const char *dname, dev_t dev,
936 unsigned long ino, unsigned invalidating)
937 {
938 struct audit_watch *owatch, *nwatch, *nextw;
939 struct audit_krule *r, *nextr;
940 struct audit_entry *oentry, *nentry;
941 struct audit_buffer *ab;
942
943 mutex_lock(&audit_filter_mutex);
944 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
945 if (audit_compare_dname_path(dname, owatch->path, NULL))
946 continue;
947
948 /* If the update involves invalidating rules, do the inode-based
949 * filtering now, so we don't omit records. */
950 if (invalidating && current->audit_context &&
951 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
952 audit_set_auditable(current->audit_context);
953
954 nwatch = audit_dupe_watch(owatch);
955 if (unlikely(IS_ERR(nwatch))) {
956 mutex_unlock(&audit_filter_mutex);
957 audit_panic("error updating watch, skipping");
958 return;
959 }
960 nwatch->dev = dev;
961 nwatch->ino = ino;
962
963 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
964
965 oentry = container_of(r, struct audit_entry, rule);
966 list_del(&oentry->rule.rlist);
967 list_del_rcu(&oentry->list);
968
969 nentry = audit_dupe_rule(&oentry->rule, nwatch);
970 if (unlikely(IS_ERR(nentry)))
971 audit_panic("error updating watch, removing");
972 else {
973 int h = audit_hash_ino((u32)ino);
974 list_add(&nentry->rule.rlist, &nwatch->rules);
975 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
976 }
977
978 call_rcu(&oentry->rcu, audit_free_rule_rcu);
979 }
980
981 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
982 audit_log_format(ab, "op=updated rules specifying path=");
983 audit_log_untrustedstring(ab, owatch->path);
984 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
985 audit_log_format(ab, " list=%d res=1", r->listnr);
986 audit_log_end(ab);
987
988 audit_remove_watch(owatch);
989 goto add_watch_to_parent; /* event applies to a single watch */
990 }
991 mutex_unlock(&audit_filter_mutex);
992 return;
993
994 add_watch_to_parent:
995 list_add(&nwatch->wlist, &parent->watches);
996 mutex_unlock(&audit_filter_mutex);
997 return;
998 }
999
1000 /* Remove all watches & rules associated with a parent that is going away. */
1001 static void audit_remove_parent_watches(struct audit_parent *parent)
1002 {
1003 struct audit_watch *w, *nextw;
1004 struct audit_krule *r, *nextr;
1005 struct audit_entry *e;
1006 struct audit_buffer *ab;
1007
1008 mutex_lock(&audit_filter_mutex);
1009 parent->flags |= AUDIT_PARENT_INVALID;
1010 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
1011 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
1012 e = container_of(r, struct audit_entry, rule);
1013
1014 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1015 audit_log_format(ab, "op=remove rule path=");
1016 audit_log_untrustedstring(ab, w->path);
1017 if (r->filterkey) {
1018 audit_log_format(ab, " key=");
1019 audit_log_untrustedstring(ab, r->filterkey);
1020 } else
1021 audit_log_format(ab, " key=(null)");
1022 audit_log_format(ab, " list=%d res=1", r->listnr);
1023 audit_log_end(ab);
1024
1025 list_del(&r->rlist);
1026 list_del_rcu(&e->list);
1027 call_rcu(&e->rcu, audit_free_rule_rcu);
1028 }
1029 audit_remove_watch(w);
1030 }
1031 mutex_unlock(&audit_filter_mutex);
1032 }
1033
1034 /* Unregister inotify watches for parents on in_list.
1035 * Generates an IN_IGNORED event. */
1036 static void audit_inotify_unregister(struct list_head *in_list)
1037 {
1038 struct audit_parent *p, *n;
1039
1040 list_for_each_entry_safe(p, n, in_list, ilist) {
1041 list_del(&p->ilist);
1042 inotify_rm_watch(audit_ih, &p->wdata);
1043 /* the put matching the get in audit_do_del_rule() */
1044 put_inotify_watch(&p->wdata);
1045 }
1046 }
1047
1048 /* Find an existing audit rule.
1049 * Caller must hold audit_filter_mutex to prevent stale rule data. */
1050 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
1051 struct list_head *list)
1052 {
1053 struct audit_entry *e, *found = NULL;
1054 int h;
1055
1056 if (entry->rule.watch) {
1057 /* we don't know the inode number, so must walk entire hash */
1058 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
1059 list = &audit_inode_hash[h];
1060 list_for_each_entry(e, list, list)
1061 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1062 found = e;
1063 goto out;
1064 }
1065 }
1066 goto out;
1067 }
1068
1069 list_for_each_entry(e, list, list)
1070 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1071 found = e;
1072 goto out;
1073 }
1074
1075 out:
1076 return found;
1077 }
1078
1079 /* Get path information necessary for adding watches. */
1080 static int audit_get_nd(char *path, struct nameidata **ndp,
1081 struct nameidata **ndw)
1082 {
1083 struct nameidata *ndparent, *ndwatch;
1084 int err;
1085
1086 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1087 if (unlikely(!ndparent))
1088 return -ENOMEM;
1089
1090 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1091 if (unlikely(!ndwatch)) {
1092 kfree(ndparent);
1093 return -ENOMEM;
1094 }
1095
1096 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1097 if (err) {
1098 kfree(ndparent);
1099 kfree(ndwatch);
1100 return err;
1101 }
1102
1103 err = path_lookup(path, 0, ndwatch);
1104 if (err) {
1105 kfree(ndwatch);
1106 ndwatch = NULL;
1107 }
1108
1109 *ndp = ndparent;
1110 *ndw = ndwatch;
1111
1112 return 0;
1113 }
1114
1115 /* Release resources used for watch path information. */
1116 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1117 {
1118 if (ndp) {
1119 path_release(ndp);
1120 kfree(ndp);
1121 }
1122 if (ndw) {
1123 path_release(ndw);
1124 kfree(ndw);
1125 }
1126 }
1127
1128 /* Associate the given rule with an existing parent inotify_watch.
1129 * Caller must hold audit_filter_mutex. */
1130 static void audit_add_to_parent(struct audit_krule *krule,
1131 struct audit_parent *parent)
1132 {
1133 struct audit_watch *w, *watch = krule->watch;
1134 int watch_found = 0;
1135
1136 list_for_each_entry(w, &parent->watches, wlist) {
1137 if (strcmp(watch->path, w->path))
1138 continue;
1139
1140 watch_found = 1;
1141
1142 /* put krule's and initial refs to temporary watch */
1143 audit_put_watch(watch);
1144 audit_put_watch(watch);
1145
1146 audit_get_watch(w);
1147 krule->watch = watch = w;
1148 break;
1149 }
1150
1151 if (!watch_found) {
1152 get_inotify_watch(&parent->wdata);
1153 watch->parent = parent;
1154
1155 list_add(&watch->wlist, &parent->watches);
1156 }
1157 list_add(&krule->rlist, &watch->rules);
1158 }
1159
1160 /* Find a matching watch entry, or add this one.
1161 * Caller must hold audit_filter_mutex. */
1162 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1163 struct nameidata *ndw)
1164 {
1165 struct audit_watch *watch = krule->watch;
1166 struct inotify_watch *i_watch;
1167 struct audit_parent *parent;
1168 int ret = 0;
1169
1170 /* update watch filter fields */
1171 if (ndw) {
1172 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1173 watch->ino = ndw->dentry->d_inode->i_ino;
1174 }
1175
1176 /* The audit_filter_mutex must not be held during inotify calls because
1177 * we hold it during inotify event callback processing. If an existing
1178 * inotify watch is found, inotify_find_watch() grabs a reference before
1179 * returning.
1180 */
1181 mutex_unlock(&audit_filter_mutex);
1182
1183 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1184 parent = audit_init_parent(ndp);
1185 if (IS_ERR(parent)) {
1186 /* caller expects mutex locked */
1187 mutex_lock(&audit_filter_mutex);
1188 return PTR_ERR(parent);
1189 }
1190 } else
1191 parent = container_of(i_watch, struct audit_parent, wdata);
1192
1193 mutex_lock(&audit_filter_mutex);
1194
1195 /* parent was moved before we took audit_filter_mutex */
1196 if (parent->flags & AUDIT_PARENT_INVALID)
1197 ret = -ENOENT;
1198 else
1199 audit_add_to_parent(krule, parent);
1200
1201 /* match get in audit_init_parent or inotify_find_watch */
1202 put_inotify_watch(&parent->wdata);
1203 return ret;
1204 }
1205
1206 /* Add rule to given filterlist if not a duplicate. */
1207 static inline int audit_add_rule(struct audit_entry *entry,
1208 struct list_head *list)
1209 {
1210 struct audit_entry *e;
1211 struct audit_field *inode_f = entry->rule.inode_f;
1212 struct audit_watch *watch = entry->rule.watch;
1213 struct nameidata *ndp, *ndw;
1214 int h, err, putnd_needed = 0;
1215 #ifdef CONFIG_AUDITSYSCALL
1216 int dont_count = 0;
1217
1218 /* If either of these, don't count towards total */
1219 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1220 entry->rule.listnr == AUDIT_FILTER_TYPE)
1221 dont_count = 1;
1222 #endif
1223
1224 if (inode_f) {
1225 h = audit_hash_ino(inode_f->val);
1226 list = &audit_inode_hash[h];
1227 }
1228
1229 mutex_lock(&audit_filter_mutex);
1230 e = audit_find_rule(entry, list);
1231 mutex_unlock(&audit_filter_mutex);
1232 if (e) {
1233 err = -EEXIST;
1234 goto error;
1235 }
1236
1237 /* Avoid calling path_lookup under audit_filter_mutex. */
1238 if (watch) {
1239 err = audit_get_nd(watch->path, &ndp, &ndw);
1240 if (err)
1241 goto error;
1242 putnd_needed = 1;
1243 }
1244
1245 mutex_lock(&audit_filter_mutex);
1246 if (watch) {
1247 /* audit_filter_mutex is dropped and re-taken during this call */
1248 err = audit_add_watch(&entry->rule, ndp, ndw);
1249 if (err) {
1250 mutex_unlock(&audit_filter_mutex);
1251 goto error;
1252 }
1253 h = audit_hash_ino((u32)watch->ino);
1254 list = &audit_inode_hash[h];
1255 }
1256
1257 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1258 list_add_rcu(&entry->list, list);
1259 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1260 } else {
1261 list_add_tail_rcu(&entry->list, list);
1262 }
1263 #ifdef CONFIG_AUDITSYSCALL
1264 if (!dont_count)
1265 audit_n_rules++;
1266
1267 if (!audit_match_signal(entry))
1268 audit_signals++;
1269 #endif
1270 mutex_unlock(&audit_filter_mutex);
1271
1272 if (putnd_needed)
1273 audit_put_nd(ndp, ndw);
1274
1275 return 0;
1276
1277 error:
1278 if (putnd_needed)
1279 audit_put_nd(ndp, ndw);
1280 if (watch)
1281 audit_put_watch(watch); /* tmp watch, matches initial get */
1282 return err;
1283 }
1284
1285 /* Remove an existing rule from filterlist. */
1286 static inline int audit_del_rule(struct audit_entry *entry,
1287 struct list_head *list)
1288 {
1289 struct audit_entry *e;
1290 struct audit_field *inode_f = entry->rule.inode_f;
1291 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1292 LIST_HEAD(inotify_list);
1293 int h, ret = 0;
1294 #ifdef CONFIG_AUDITSYSCALL
1295 int dont_count = 0;
1296
1297 /* If either of these, don't count towards total */
1298 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1299 entry->rule.listnr == AUDIT_FILTER_TYPE)
1300 dont_count = 1;
1301 #endif
1302
1303 if (inode_f) {
1304 h = audit_hash_ino(inode_f->val);
1305 list = &audit_inode_hash[h];
1306 }
1307
1308 mutex_lock(&audit_filter_mutex);
1309 e = audit_find_rule(entry, list);
1310 if (!e) {
1311 mutex_unlock(&audit_filter_mutex);
1312 ret = -ENOENT;
1313 goto out;
1314 }
1315
1316 watch = e->rule.watch;
1317 if (watch) {
1318 struct audit_parent *parent = watch->parent;
1319
1320 list_del(&e->rule.rlist);
1321
1322 if (list_empty(&watch->rules)) {
1323 audit_remove_watch(watch);
1324
1325 if (list_empty(&parent->watches)) {
1326 /* Put parent on the inotify un-registration
1327 * list. Grab a reference before releasing
1328 * audit_filter_mutex, to be released in
1329 * audit_inotify_unregister(). */
1330 list_add(&parent->ilist, &inotify_list);
1331 get_inotify_watch(&parent->wdata);
1332 }
1333 }
1334 }
1335
1336 list_del_rcu(&e->list);
1337 call_rcu(&e->rcu, audit_free_rule_rcu);
1338
1339 #ifdef CONFIG_AUDITSYSCALL
1340 if (!dont_count)
1341 audit_n_rules--;
1342
1343 if (!audit_match_signal(entry))
1344 audit_signals--;
1345 #endif
1346 mutex_unlock(&audit_filter_mutex);
1347
1348 if (!list_empty(&inotify_list))
1349 audit_inotify_unregister(&inotify_list);
1350
1351 out:
1352 if (tmp_watch)
1353 audit_put_watch(tmp_watch); /* match initial get */
1354
1355 return ret;
1356 }
1357
1358 /* List rules using struct audit_rule. Exists for backward
1359 * compatibility with userspace. */
1360 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1361 {
1362 struct sk_buff *skb;
1363 struct audit_entry *entry;
1364 int i;
1365
1366 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1367 * iterator to sync with list writers. */
1368 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1369 list_for_each_entry(entry, &audit_filter_list[i], list) {
1370 struct audit_rule *rule;
1371
1372 rule = audit_krule_to_rule(&entry->rule);
1373 if (unlikely(!rule))
1374 break;
1375 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1376 rule, sizeof(*rule));
1377 if (skb)
1378 skb_queue_tail(q, skb);
1379 kfree(rule);
1380 }
1381 }
1382 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1383 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1384 struct audit_rule *rule;
1385
1386 rule = audit_krule_to_rule(&entry->rule);
1387 if (unlikely(!rule))
1388 break;
1389 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1390 rule, sizeof(*rule));
1391 if (skb)
1392 skb_queue_tail(q, skb);
1393 kfree(rule);
1394 }
1395 }
1396 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1397 if (skb)
1398 skb_queue_tail(q, skb);
1399 }
1400
1401 /* List rules using struct audit_rule_data. */
1402 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1403 {
1404 struct sk_buff *skb;
1405 struct audit_entry *e;
1406 int i;
1407
1408 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1409 * iterator to sync with list writers. */
1410 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1411 list_for_each_entry(e, &audit_filter_list[i], list) {
1412 struct audit_rule_data *data;
1413
1414 data = audit_krule_to_data(&e->rule);
1415 if (unlikely(!data))
1416 break;
1417 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1418 data, sizeof(*data) + data->buflen);
1419 if (skb)
1420 skb_queue_tail(q, skb);
1421 kfree(data);
1422 }
1423 }
1424 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1425 list_for_each_entry(e, &audit_inode_hash[i], list) {
1426 struct audit_rule_data *data;
1427
1428 data = audit_krule_to_data(&e->rule);
1429 if (unlikely(!data))
1430 break;
1431 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1432 data, sizeof(*data) + data->buflen);
1433 if (skb)
1434 skb_queue_tail(q, skb);
1435 kfree(data);
1436 }
1437 }
1438 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1439 if (skb)
1440 skb_queue_tail(q, skb);
1441 }
1442
1443 /* Log rule additions and removals */
1444 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1445 struct audit_krule *rule, int res)
1446 {
1447 struct audit_buffer *ab;
1448
1449 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1450 if (!ab)
1451 return;
1452 audit_log_format(ab, "auid=%u", loginuid);
1453 if (sid) {
1454 char *ctx = NULL;
1455 u32 len;
1456 if (selinux_sid_to_string(sid, &ctx, &len))
1457 audit_log_format(ab, " ssid=%u", sid);
1458 else
1459 audit_log_format(ab, " subj=%s", ctx);
1460 kfree(ctx);
1461 }
1462 audit_log_format(ab, " op=%s rule key=", action);
1463 if (rule->filterkey)
1464 audit_log_untrustedstring(ab, rule->filterkey);
1465 else
1466 audit_log_format(ab, "(null)");
1467 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1468 audit_log_end(ab);
1469 }
1470
1471 /**
1472 * audit_receive_filter - apply all rules to the specified message type
1473 * @type: audit message type
1474 * @pid: target pid for netlink audit messages
1475 * @uid: target uid for netlink audit messages
1476 * @seq: netlink audit message sequence (serial) number
1477 * @data: payload data
1478 * @datasz: size of payload data
1479 * @loginuid: loginuid of sender
1480 * @sid: SE Linux Security ID of sender
1481 */
1482 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1483 size_t datasz, uid_t loginuid, u32 sid)
1484 {
1485 struct task_struct *tsk;
1486 struct audit_netlink_list *dest;
1487 int err = 0;
1488 struct audit_entry *entry;
1489
1490 switch (type) {
1491 case AUDIT_LIST:
1492 case AUDIT_LIST_RULES:
1493 /* We can't just spew out the rules here because we might fill
1494 * the available socket buffer space and deadlock waiting for
1495 * auditctl to read from it... which isn't ever going to
1496 * happen if we're actually running in the context of auditctl
1497 * trying to _send_ the stuff */
1498
1499 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1500 if (!dest)
1501 return -ENOMEM;
1502 dest->pid = pid;
1503 skb_queue_head_init(&dest->q);
1504
1505 mutex_lock(&audit_filter_mutex);
1506 if (type == AUDIT_LIST)
1507 audit_list(pid, seq, &dest->q);
1508 else
1509 audit_list_rules(pid, seq, &dest->q);
1510 mutex_unlock(&audit_filter_mutex);
1511
1512 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1513 if (IS_ERR(tsk)) {
1514 skb_queue_purge(&dest->q);
1515 kfree(dest);
1516 err = PTR_ERR(tsk);
1517 }
1518 break;
1519 case AUDIT_ADD:
1520 case AUDIT_ADD_RULE:
1521 if (type == AUDIT_ADD)
1522 entry = audit_rule_to_entry(data);
1523 else
1524 entry = audit_data_to_entry(data, datasz);
1525 if (IS_ERR(entry))
1526 return PTR_ERR(entry);
1527
1528 err = audit_add_rule(entry,
1529 &audit_filter_list[entry->rule.listnr]);
1530 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1531
1532 if (err)
1533 audit_free_rule(entry);
1534 break;
1535 case AUDIT_DEL:
1536 case AUDIT_DEL_RULE:
1537 if (type == AUDIT_DEL)
1538 entry = audit_rule_to_entry(data);
1539 else
1540 entry = audit_data_to_entry(data, datasz);
1541 if (IS_ERR(entry))
1542 return PTR_ERR(entry);
1543
1544 err = audit_del_rule(entry,
1545 &audit_filter_list[entry->rule.listnr]);
1546 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1547 !err);
1548
1549 audit_free_rule(entry);
1550 break;
1551 default:
1552 return -EINVAL;
1553 }
1554
1555 return err;
1556 }
1557
1558 int audit_comparator(const u32 left, const u32 op, const u32 right)
1559 {
1560 switch (op) {
1561 case AUDIT_EQUAL:
1562 return (left == right);
1563 case AUDIT_NOT_EQUAL:
1564 return (left != right);
1565 case AUDIT_LESS_THAN:
1566 return (left < right);
1567 case AUDIT_LESS_THAN_OR_EQUAL:
1568 return (left <= right);
1569 case AUDIT_GREATER_THAN:
1570 return (left > right);
1571 case AUDIT_GREATER_THAN_OR_EQUAL:
1572 return (left >= right);
1573 }
1574 BUG();
1575 return 0;
1576 }
1577
1578 /* Compare given dentry name with last component in given path,
1579 * return of 0 indicates a match. */
1580 int audit_compare_dname_path(const char *dname, const char *path,
1581 int *dirlen)
1582 {
1583 int dlen, plen;
1584 const char *p;
1585
1586 if (!dname || !path)
1587 return 1;
1588
1589 dlen = strlen(dname);
1590 plen = strlen(path);
1591 if (plen < dlen)
1592 return 1;
1593
1594 /* disregard trailing slashes */
1595 p = path + plen - 1;
1596 while ((*p == '/') && (p > path))
1597 p--;
1598
1599 /* find last path component */
1600 p = p - dlen + 1;
1601 if (p < path)
1602 return 1;
1603 else if (p > path) {
1604 if (*--p != '/')
1605 return 1;
1606 else
1607 p++;
1608 }
1609
1610 /* return length of path's directory component */
1611 if (dirlen)
1612 *dirlen = p - path;
1613 return strncmp(p, dname, dlen);
1614 }
1615
1616 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1617 struct audit_krule *rule,
1618 enum audit_state *state)
1619 {
1620 int i;
1621
1622 for (i = 0; i < rule->field_count; i++) {
1623 struct audit_field *f = &rule->fields[i];
1624 int result = 0;
1625
1626 switch (f->type) {
1627 case AUDIT_PID:
1628 result = audit_comparator(cb->creds.pid, f->op, f->val);
1629 break;
1630 case AUDIT_UID:
1631 result = audit_comparator(cb->creds.uid, f->op, f->val);
1632 break;
1633 case AUDIT_GID:
1634 result = audit_comparator(cb->creds.gid, f->op, f->val);
1635 break;
1636 case AUDIT_LOGINUID:
1637 result = audit_comparator(cb->loginuid, f->op, f->val);
1638 break;
1639 }
1640
1641 if (!result)
1642 return 0;
1643 }
1644 switch (rule->action) {
1645 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1646 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1647 }
1648 return 1;
1649 }
1650
1651 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1652 {
1653 enum audit_state state = AUDIT_DISABLED;
1654 struct audit_entry *e;
1655 int ret = 1;
1656
1657 rcu_read_lock();
1658 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1659 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1660 if (state == AUDIT_DISABLED)
1661 ret = 0;
1662 break;
1663 }
1664 }
1665 rcu_read_unlock();
1666
1667 return ret; /* Audit by default */
1668 }
1669
1670 int audit_filter_type(int type)
1671 {
1672 struct audit_entry *e;
1673 int result = 0;
1674
1675 rcu_read_lock();
1676 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1677 goto unlock_and_return;
1678
1679 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1680 list) {
1681 int i;
1682 for (i = 0; i < e->rule.field_count; i++) {
1683 struct audit_field *f = &e->rule.fields[i];
1684 if (f->type == AUDIT_MSGTYPE) {
1685 result = audit_comparator(type, f->op, f->val);
1686 if (!result)
1687 break;
1688 }
1689 }
1690 if (result)
1691 goto unlock_and_return;
1692 }
1693 unlock_and_return:
1694 rcu_read_unlock();
1695 return result;
1696 }
1697
1698 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1699 are selinux fields specified in the rule, 0 otherwise. */
1700 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1701 {
1702 int i;
1703
1704 for (i = 0; i < rule->field_count; i++) {
1705 struct audit_field *f = &rule->fields[i];
1706 switch (f->type) {
1707 case AUDIT_SUBJ_USER:
1708 case AUDIT_SUBJ_ROLE:
1709 case AUDIT_SUBJ_TYPE:
1710 case AUDIT_SUBJ_SEN:
1711 case AUDIT_SUBJ_CLR:
1712 case AUDIT_OBJ_USER:
1713 case AUDIT_OBJ_ROLE:
1714 case AUDIT_OBJ_TYPE:
1715 case AUDIT_OBJ_LEV_LOW:
1716 case AUDIT_OBJ_LEV_HIGH:
1717 return 1;
1718 }
1719 }
1720
1721 return 0;
1722 }
1723
1724 /* This function will re-initialize the se_rule field of all applicable rules.
1725 * It will traverse the filter lists serarching for rules that contain selinux
1726 * specific filter fields. When such a rule is found, it is copied, the
1727 * selinux field is re-initialized, and the old rule is replaced with the
1728 * updated rule. */
1729 int selinux_audit_rule_update(void)
1730 {
1731 struct audit_entry *entry, *n, *nentry;
1732 struct audit_watch *watch;
1733 int i, err = 0;
1734
1735 /* audit_filter_mutex synchronizes the writers */
1736 mutex_lock(&audit_filter_mutex);
1737
1738 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1739 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1740 if (!audit_rule_has_selinux(&entry->rule))
1741 continue;
1742
1743 watch = entry->rule.watch;
1744 nentry = audit_dupe_rule(&entry->rule, watch);
1745 if (unlikely(IS_ERR(nentry))) {
1746 /* save the first error encountered for the
1747 * return value */
1748 if (!err)
1749 err = PTR_ERR(nentry);
1750 audit_panic("error updating selinux filters");
1751 if (watch)
1752 list_del(&entry->rule.rlist);
1753 list_del_rcu(&entry->list);
1754 } else {
1755 if (watch) {
1756 list_add(&nentry->rule.rlist,
1757 &watch->rules);
1758 list_del(&entry->rule.rlist);
1759 }
1760 list_replace_rcu(&entry->list, &nentry->list);
1761 }
1762 call_rcu(&entry->rcu, audit_free_rule_rcu);
1763 }
1764 }
1765
1766 mutex_unlock(&audit_filter_mutex);
1767
1768 return err;
1769 }
1770
1771 /* Update watch data in audit rules based on inotify events. */
1772 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1773 u32 cookie, const char *dname, struct inode *inode)
1774 {
1775 struct audit_parent *parent;
1776
1777 parent = container_of(i_watch, struct audit_parent, wdata);
1778
1779 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1780 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1781 inode->i_ino, 0);
1782 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1783 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1784 /* inotify automatically removes the watch and sends IN_IGNORED */
1785 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1786 audit_remove_parent_watches(parent);
1787 /* inotify does not remove the watch, so remove it manually */
1788 else if(mask & IN_MOVE_SELF) {
1789 audit_remove_parent_watches(parent);
1790 inotify_remove_watch_locked(audit_ih, i_watch);
1791 } else if (mask & IN_IGNORED)
1792 put_inotify_watch(i_watch);
1793 }
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