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[ALSA] usb-audio: fix parsing of SysEx messages from CME keyboards
[linux-2.6/kmemtrace.git] / kernel / auditfilter.c
blob359645cff5b2cd662ea209458203eef6b1e96976
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 * 32))
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 /* bit ops are only useful on syscall args */
460 if (f->op == AUDIT_BIT_MASK ||
461 f->op == AUDIT_BIT_TEST) {
462 err = -EINVAL;
463 goto exit_free;
464 }
465 break;
466 case AUDIT_ARG0:
467 case AUDIT_ARG1:
468 case AUDIT_ARG2:
469 case AUDIT_ARG3:
470 break;
471 /* arch is only allowed to be = or != */
472 case AUDIT_ARCH:
473 if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL)
474 && (f->op != AUDIT_NEGATE) && (f->op)) {
475 err = -EINVAL;
476 goto exit_free;
477 }
478 entry->rule.arch_f = f;
479 break;
480 case AUDIT_PERM:
481 if (f->val & ~15)
482 goto exit_free;
483 break;
484 case AUDIT_INODE:
485 err = audit_to_inode(&entry->rule, f);
486 if (err)
487 goto exit_free;
488 break;
489 }
490
491 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
492
493 /* Support for legacy operators where
494 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
495 if (f->op & AUDIT_NEGATE)
496 f->op = AUDIT_NOT_EQUAL;
497 else if (!f->op)
498 f->op = AUDIT_EQUAL;
499 else if (f->op == AUDIT_OPERATORS) {
500 err = -EINVAL;
501 goto exit_free;
502 }
503 }
504
505 f = entry->rule.inode_f;
506 if (f) {
507 switch(f->op) {
508 case AUDIT_NOT_EQUAL:
509 entry->rule.inode_f = NULL;
510 case AUDIT_EQUAL:
511 break;
512 default:
513 err = -EINVAL;
514 goto exit_free;
515 }
516 }
517
518 exit_nofree:
519 return entry;
520
521 exit_free:
522 audit_free_rule(entry);
523 return ERR_PTR(err);
524 }
525
526 /* Translate struct audit_rule_data to kernel's rule respresentation. */
527 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
528 size_t datasz)
529 {
530 int err = 0;
531 struct audit_entry *entry;
532 struct audit_field *f;
533 void *bufp;
534 size_t remain = datasz - sizeof(struct audit_rule_data);
535 int i;
536 char *str;
537
538 entry = audit_to_entry_common((struct audit_rule *)data);
539 if (IS_ERR(entry))
540 goto exit_nofree;
541
542 bufp = data->buf;
543 entry->rule.vers_ops = 2;
544 for (i = 0; i < data->field_count; i++) {
545 struct audit_field *f = &entry->rule.fields[i];
546
547 err = -EINVAL;
548 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
549 data->fieldflags[i] & ~AUDIT_OPERATORS)
550 goto exit_free;
551
552 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
553 f->type = data->fields[i];
554 f->val = data->values[i];
555 f->se_str = NULL;
556 f->se_rule = NULL;
557 switch(f->type) {
558 case AUDIT_PID:
559 case AUDIT_UID:
560 case AUDIT_EUID:
561 case AUDIT_SUID:
562 case AUDIT_FSUID:
563 case AUDIT_GID:
564 case AUDIT_EGID:
565 case AUDIT_SGID:
566 case AUDIT_FSGID:
567 case AUDIT_LOGINUID:
568 case AUDIT_PERS:
569 case AUDIT_MSGTYPE:
570 case AUDIT_PPID:
571 case AUDIT_DEVMAJOR:
572 case AUDIT_DEVMINOR:
573 case AUDIT_EXIT:
574 case AUDIT_SUCCESS:
575 case AUDIT_ARG0:
576 case AUDIT_ARG1:
577 case AUDIT_ARG2:
578 case AUDIT_ARG3:
579 break;
580 case AUDIT_ARCH:
581 entry->rule.arch_f = f;
582 break;
583 case AUDIT_SUBJ_USER:
584 case AUDIT_SUBJ_ROLE:
585 case AUDIT_SUBJ_TYPE:
586 case AUDIT_SUBJ_SEN:
587 case AUDIT_SUBJ_CLR:
588 case AUDIT_OBJ_USER:
589 case AUDIT_OBJ_ROLE:
590 case AUDIT_OBJ_TYPE:
591 case AUDIT_OBJ_LEV_LOW:
592 case AUDIT_OBJ_LEV_HIGH:
593 str = audit_unpack_string(&bufp, &remain, f->val);
594 if (IS_ERR(str))
595 goto exit_free;
596 entry->rule.buflen += f->val;
597
598 err = selinux_audit_rule_init(f->type, f->op, str,
599 &f->se_rule);
600 /* Keep currently invalid fields around in case they
601 * become valid after a policy reload. */
602 if (err == -EINVAL) {
603 printk(KERN_WARNING "audit rule for selinux "
604 "\'%s\' is invalid\n", str);
605 err = 0;
606 }
607 if (err) {
608 kfree(str);
609 goto exit_free;
610 } else
611 f->se_str = str;
612 break;
613 case AUDIT_WATCH:
614 str = audit_unpack_string(&bufp, &remain, f->val);
615 if (IS_ERR(str))
616 goto exit_free;
617 entry->rule.buflen += f->val;
618
619 err = audit_to_watch(&entry->rule, str, f->val, f->op);
620 if (err) {
621 kfree(str);
622 goto exit_free;
623 }
624 break;
625 case AUDIT_INODE:
626 err = audit_to_inode(&entry->rule, f);
627 if (err)
628 goto exit_free;
629 break;
630 case AUDIT_FILTERKEY:
631 err = -EINVAL;
632 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
633 goto exit_free;
634 str = audit_unpack_string(&bufp, &remain, f->val);
635 if (IS_ERR(str))
636 goto exit_free;
637 entry->rule.buflen += f->val;
638 entry->rule.filterkey = str;
639 break;
640 case AUDIT_PERM:
641 if (f->val & ~15)
642 goto exit_free;
643 break;
644 default:
645 goto exit_free;
646 }
647 }
648
649 f = entry->rule.inode_f;
650 if (f) {
651 switch(f->op) {
652 case AUDIT_NOT_EQUAL:
653 entry->rule.inode_f = NULL;
654 case AUDIT_EQUAL:
655 break;
656 default:
657 err = -EINVAL;
658 goto exit_free;
659 }
660 }
661
662 exit_nofree:
663 return entry;
664
665 exit_free:
666 audit_free_rule(entry);
667 return ERR_PTR(err);
668 }
669
670 /* Pack a filter field's string representation into data block. */
671 static inline size_t audit_pack_string(void **bufp, char *str)
672 {
673 size_t len = strlen(str);
674
675 memcpy(*bufp, str, len);
676 *bufp += len;
677
678 return len;
679 }
680
681 /* Translate kernel rule respresentation to struct audit_rule.
682 * Exists for backward compatibility with userspace. */
683 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
684 {
685 struct audit_rule *rule;
686 int i;
687
688 rule = kzalloc(sizeof(*rule), GFP_KERNEL);
689 if (unlikely(!rule))
690 return NULL;
691
692 rule->flags = krule->flags | krule->listnr;
693 rule->action = krule->action;
694 rule->field_count = krule->field_count;
695 for (i = 0; i < rule->field_count; i++) {
696 rule->values[i] = krule->fields[i].val;
697 rule->fields[i] = krule->fields[i].type;
698
699 if (krule->vers_ops == 1) {
700 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
701 rule->fields[i] |= AUDIT_NEGATE;
702 } else {
703 rule->fields[i] |= krule->fields[i].op;
704 }
705 }
706 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
707
708 return rule;
709 }
710
711 /* Translate kernel rule respresentation to struct audit_rule_data. */
712 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
713 {
714 struct audit_rule_data *data;
715 void *bufp;
716 int i;
717
718 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
719 if (unlikely(!data))
720 return NULL;
721 memset(data, 0, sizeof(*data));
722
723 data->flags = krule->flags | krule->listnr;
724 data->action = krule->action;
725 data->field_count = krule->field_count;
726 bufp = data->buf;
727 for (i = 0; i < data->field_count; i++) {
728 struct audit_field *f = &krule->fields[i];
729
730 data->fields[i] = f->type;
731 data->fieldflags[i] = f->op;
732 switch(f->type) {
733 case AUDIT_SUBJ_USER:
734 case AUDIT_SUBJ_ROLE:
735 case AUDIT_SUBJ_TYPE:
736 case AUDIT_SUBJ_SEN:
737 case AUDIT_SUBJ_CLR:
738 case AUDIT_OBJ_USER:
739 case AUDIT_OBJ_ROLE:
740 case AUDIT_OBJ_TYPE:
741 case AUDIT_OBJ_LEV_LOW:
742 case AUDIT_OBJ_LEV_HIGH:
743 data->buflen += data->values[i] =
744 audit_pack_string(&bufp, f->se_str);
745 break;
746 case AUDIT_WATCH:
747 data->buflen += data->values[i] =
748 audit_pack_string(&bufp, krule->watch->path);
749 break;
750 case AUDIT_FILTERKEY:
751 data->buflen += data->values[i] =
752 audit_pack_string(&bufp, krule->filterkey);
753 break;
754 default:
755 data->values[i] = f->val;
756 }
757 }
758 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
759
760 return data;
761 }
762
763 /* Compare two rules in kernel format. Considered success if rules
764 * don't match. */
765 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
766 {
767 int i;
768
769 if (a->flags != b->flags ||
770 a->listnr != b->listnr ||
771 a->action != b->action ||
772 a->field_count != b->field_count)
773 return 1;
774
775 for (i = 0; i < a->field_count; i++) {
776 if (a->fields[i].type != b->fields[i].type ||
777 a->fields[i].op != b->fields[i].op)
778 return 1;
779
780 switch(a->fields[i].type) {
781 case AUDIT_SUBJ_USER:
782 case AUDIT_SUBJ_ROLE:
783 case AUDIT_SUBJ_TYPE:
784 case AUDIT_SUBJ_SEN:
785 case AUDIT_SUBJ_CLR:
786 case AUDIT_OBJ_USER:
787 case AUDIT_OBJ_ROLE:
788 case AUDIT_OBJ_TYPE:
789 case AUDIT_OBJ_LEV_LOW:
790 case AUDIT_OBJ_LEV_HIGH:
791 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
792 return 1;
793 break;
794 case AUDIT_WATCH:
795 if (strcmp(a->watch->path, b->watch->path))
796 return 1;
797 break;
798 case AUDIT_FILTERKEY:
799 /* both filterkeys exist based on above type compare */
800 if (strcmp(a->filterkey, b->filterkey))
801 return 1;
802 break;
803 default:
804 if (a->fields[i].val != b->fields[i].val)
805 return 1;
806 }
807 }
808
809 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
810 if (a->mask[i] != b->mask[i])
811 return 1;
812
813 return 0;
814 }
815
816 /* Duplicate the given audit watch. The new watch's rules list is initialized
817 * to an empty list and wlist is undefined. */
818 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
819 {
820 char *path;
821 struct audit_watch *new;
822
823 path = kstrdup(old->path, GFP_KERNEL);
824 if (unlikely(!path))
825 return ERR_PTR(-ENOMEM);
826
827 new = audit_init_watch(path);
828 if (unlikely(IS_ERR(new))) {
829 kfree(path);
830 goto out;
831 }
832
833 new->dev = old->dev;
834 new->ino = old->ino;
835 get_inotify_watch(&old->parent->wdata);
836 new->parent = old->parent;
837
838 out:
839 return new;
840 }
841
842 /* Duplicate selinux field information. The se_rule is opaque, so must be
843 * re-initialized. */
844 static inline int audit_dupe_selinux_field(struct audit_field *df,
845 struct audit_field *sf)
846 {
847 int ret = 0;
848 char *se_str;
849
850 /* our own copy of se_str */
851 se_str = kstrdup(sf->se_str, GFP_KERNEL);
852 if (unlikely(!se_str))
853 return -ENOMEM;
854 df->se_str = se_str;
855
856 /* our own (refreshed) copy of se_rule */
857 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
858 &df->se_rule);
859 /* Keep currently invalid fields around in case they
860 * become valid after a policy reload. */
861 if (ret == -EINVAL) {
862 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
863 "invalid\n", df->se_str);
864 ret = 0;
865 }
866
867 return ret;
868 }
869
870 /* Duplicate an audit rule. This will be a deep copy with the exception
871 * of the watch - that pointer is carried over. The selinux specific fields
872 * will be updated in the copy. The point is to be able to replace the old
873 * rule with the new rule in the filterlist, then free the old rule.
874 * The rlist element is undefined; list manipulations are handled apart from
875 * the initial copy. */
876 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
877 struct audit_watch *watch)
878 {
879 u32 fcount = old->field_count;
880 struct audit_entry *entry;
881 struct audit_krule *new;
882 char *fk;
883 int i, err = 0;
884
885 entry = audit_init_entry(fcount);
886 if (unlikely(!entry))
887 return ERR_PTR(-ENOMEM);
888
889 new = &entry->rule;
890 new->vers_ops = old->vers_ops;
891 new->flags = old->flags;
892 new->listnr = old->listnr;
893 new->action = old->action;
894 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
895 new->mask[i] = old->mask[i];
896 new->buflen = old->buflen;
897 new->inode_f = old->inode_f;
898 new->watch = NULL;
899 new->field_count = old->field_count;
900 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
901
902 /* deep copy this information, updating the se_rule fields, because
903 * the originals will all be freed when the old rule is freed. */
904 for (i = 0; i < fcount; i++) {
905 switch (new->fields[i].type) {
906 case AUDIT_SUBJ_USER:
907 case AUDIT_SUBJ_ROLE:
908 case AUDIT_SUBJ_TYPE:
909 case AUDIT_SUBJ_SEN:
910 case AUDIT_SUBJ_CLR:
911 case AUDIT_OBJ_USER:
912 case AUDIT_OBJ_ROLE:
913 case AUDIT_OBJ_TYPE:
914 case AUDIT_OBJ_LEV_LOW:
915 case AUDIT_OBJ_LEV_HIGH:
916 err = audit_dupe_selinux_field(&new->fields[i],
917 &old->fields[i]);
918 break;
919 case AUDIT_FILTERKEY:
920 fk = kstrdup(old->filterkey, GFP_KERNEL);
921 if (unlikely(!fk))
922 err = -ENOMEM;
923 else
924 new->filterkey = fk;
925 }
926 if (err) {
927 audit_free_rule(entry);
928 return ERR_PTR(err);
929 }
930 }
931
932 if (watch) {
933 audit_get_watch(watch);
934 new->watch = watch;
935 }
936
937 return entry;
938 }
939
940 /* Update inode info in audit rules based on filesystem event. */
941 static void audit_update_watch(struct audit_parent *parent,
942 const char *dname, dev_t dev,
943 unsigned long ino, unsigned invalidating)
944 {
945 struct audit_watch *owatch, *nwatch, *nextw;
946 struct audit_krule *r, *nextr;
947 struct audit_entry *oentry, *nentry;
948 struct audit_buffer *ab;
949
950 mutex_lock(&audit_filter_mutex);
951 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
952 if (audit_compare_dname_path(dname, owatch->path, NULL))
953 continue;
954
955 /* If the update involves invalidating rules, do the inode-based
956 * filtering now, so we don't omit records. */
957 if (invalidating && current->audit_context &&
958 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
959 audit_set_auditable(current->audit_context);
960
961 nwatch = audit_dupe_watch(owatch);
962 if (unlikely(IS_ERR(nwatch))) {
963 mutex_unlock(&audit_filter_mutex);
964 audit_panic("error updating watch, skipping");
965 return;
966 }
967 nwatch->dev = dev;
968 nwatch->ino = ino;
969
970 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
971
972 oentry = container_of(r, struct audit_entry, rule);
973 list_del(&oentry->rule.rlist);
974 list_del_rcu(&oentry->list);
975
976 nentry = audit_dupe_rule(&oentry->rule, nwatch);
977 if (unlikely(IS_ERR(nentry)))
978 audit_panic("error updating watch, removing");
979 else {
980 int h = audit_hash_ino((u32)ino);
981 list_add(&nentry->rule.rlist, &nwatch->rules);
982 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
983 }
984
985 call_rcu(&oentry->rcu, audit_free_rule_rcu);
986 }
987
988 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
989 audit_log_format(ab, "op=updated rules specifying path=");
990 audit_log_untrustedstring(ab, owatch->path);
991 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
992 audit_log_format(ab, " list=%d res=1", r->listnr);
993 audit_log_end(ab);
994
995 audit_remove_watch(owatch);
996 goto add_watch_to_parent; /* event applies to a single watch */
997 }
998 mutex_unlock(&audit_filter_mutex);
999 return;
1000
1001 add_watch_to_parent:
1002 list_add(&nwatch->wlist, &parent->watches);
1003 mutex_unlock(&audit_filter_mutex);
1004 return;
1005 }
1006
1007 /* Remove all watches & rules associated with a parent that is going away. */
1008 static void audit_remove_parent_watches(struct audit_parent *parent)
1009 {
1010 struct audit_watch *w, *nextw;
1011 struct audit_krule *r, *nextr;
1012 struct audit_entry *e;
1013 struct audit_buffer *ab;
1014
1015 mutex_lock(&audit_filter_mutex);
1016 parent->flags |= AUDIT_PARENT_INVALID;
1017 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
1018 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
1019 e = container_of(r, struct audit_entry, rule);
1020
1021 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1022 audit_log_format(ab, "op=remove rule path=");
1023 audit_log_untrustedstring(ab, w->path);
1024 if (r->filterkey) {
1025 audit_log_format(ab, " key=");
1026 audit_log_untrustedstring(ab, r->filterkey);
1027 } else
1028 audit_log_format(ab, " key=(null)");
1029 audit_log_format(ab, " list=%d res=1", r->listnr);
1030 audit_log_end(ab);
1031
1032 list_del(&r->rlist);
1033 list_del_rcu(&e->list);
1034 call_rcu(&e->rcu, audit_free_rule_rcu);
1035 }
1036 audit_remove_watch(w);
1037 }
1038 mutex_unlock(&audit_filter_mutex);
1039 }
1040
1041 /* Unregister inotify watches for parents on in_list.
1042 * Generates an IN_IGNORED event. */
1043 static void audit_inotify_unregister(struct list_head *in_list)
1044 {
1045 struct audit_parent *p, *n;
1046
1047 list_for_each_entry_safe(p, n, in_list, ilist) {
1048 list_del(&p->ilist);
1049 inotify_rm_watch(audit_ih, &p->wdata);
1050 /* the put matching the get in audit_do_del_rule() */
1051 put_inotify_watch(&p->wdata);
1052 }
1053 }
1054
1055 /* Find an existing audit rule.
1056 * Caller must hold audit_filter_mutex to prevent stale rule data. */
1057 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
1058 struct list_head *list)
1059 {
1060 struct audit_entry *e, *found = NULL;
1061 int h;
1062
1063 if (entry->rule.watch) {
1064 /* we don't know the inode number, so must walk entire hash */
1065 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
1066 list = &audit_inode_hash[h];
1067 list_for_each_entry(e, list, list)
1068 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1069 found = e;
1070 goto out;
1071 }
1072 }
1073 goto out;
1074 }
1075
1076 list_for_each_entry(e, list, list)
1077 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1078 found = e;
1079 goto out;
1080 }
1081
1082 out:
1083 return found;
1084 }
1085
1086 /* Get path information necessary for adding watches. */
1087 static int audit_get_nd(char *path, struct nameidata **ndp,
1088 struct nameidata **ndw)
1089 {
1090 struct nameidata *ndparent, *ndwatch;
1091 int err;
1092
1093 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1094 if (unlikely(!ndparent))
1095 return -ENOMEM;
1096
1097 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1098 if (unlikely(!ndwatch)) {
1099 kfree(ndparent);
1100 return -ENOMEM;
1101 }
1102
1103 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1104 if (err) {
1105 kfree(ndparent);
1106 kfree(ndwatch);
1107 return err;
1108 }
1109
1110 err = path_lookup(path, 0, ndwatch);
1111 if (err) {
1112 kfree(ndwatch);
1113 ndwatch = NULL;
1114 }
1115
1116 *ndp = ndparent;
1117 *ndw = ndwatch;
1118
1119 return 0;
1120 }
1121
1122 /* Release resources used for watch path information. */
1123 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1124 {
1125 if (ndp) {
1126 path_release(ndp);
1127 kfree(ndp);
1128 }
1129 if (ndw) {
1130 path_release(ndw);
1131 kfree(ndw);
1132 }
1133 }
1134
1135 /* Associate the given rule with an existing parent inotify_watch.
1136 * Caller must hold audit_filter_mutex. */
1137 static void audit_add_to_parent(struct audit_krule *krule,
1138 struct audit_parent *parent)
1139 {
1140 struct audit_watch *w, *watch = krule->watch;
1141 int watch_found = 0;
1142
1143 list_for_each_entry(w, &parent->watches, wlist) {
1144 if (strcmp(watch->path, w->path))
1145 continue;
1146
1147 watch_found = 1;
1148
1149 /* put krule's and initial refs to temporary watch */
1150 audit_put_watch(watch);
1151 audit_put_watch(watch);
1152
1153 audit_get_watch(w);
1154 krule->watch = watch = w;
1155 break;
1156 }
1157
1158 if (!watch_found) {
1159 get_inotify_watch(&parent->wdata);
1160 watch->parent = parent;
1161
1162 list_add(&watch->wlist, &parent->watches);
1163 }
1164 list_add(&krule->rlist, &watch->rules);
1165 }
1166
1167 /* Find a matching watch entry, or add this one.
1168 * Caller must hold audit_filter_mutex. */
1169 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1170 struct nameidata *ndw)
1171 {
1172 struct audit_watch *watch = krule->watch;
1173 struct inotify_watch *i_watch;
1174 struct audit_parent *parent;
1175 int ret = 0;
1176
1177 /* update watch filter fields */
1178 if (ndw) {
1179 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1180 watch->ino = ndw->dentry->d_inode->i_ino;
1181 }
1182
1183 /* The audit_filter_mutex must not be held during inotify calls because
1184 * we hold it during inotify event callback processing. If an existing
1185 * inotify watch is found, inotify_find_watch() grabs a reference before
1186 * returning.
1187 */
1188 mutex_unlock(&audit_filter_mutex);
1189
1190 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1191 parent = audit_init_parent(ndp);
1192 if (IS_ERR(parent)) {
1193 /* caller expects mutex locked */
1194 mutex_lock(&audit_filter_mutex);
1195 return PTR_ERR(parent);
1196 }
1197 } else
1198 parent = container_of(i_watch, struct audit_parent, wdata);
1199
1200 mutex_lock(&audit_filter_mutex);
1201
1202 /* parent was moved before we took audit_filter_mutex */
1203 if (parent->flags & AUDIT_PARENT_INVALID)
1204 ret = -ENOENT;
1205 else
1206 audit_add_to_parent(krule, parent);
1207
1208 /* match get in audit_init_parent or inotify_find_watch */
1209 put_inotify_watch(&parent->wdata);
1210 return ret;
1211 }
1212
1213 /* Add rule to given filterlist if not a duplicate. */
1214 static inline int audit_add_rule(struct audit_entry *entry,
1215 struct list_head *list)
1216 {
1217 struct audit_entry *e;
1218 struct audit_field *inode_f = entry->rule.inode_f;
1219 struct audit_watch *watch = entry->rule.watch;
1220 struct nameidata *ndp = NULL, *ndw = NULL;
1221 int h, err;
1222 #ifdef CONFIG_AUDITSYSCALL
1223 int dont_count = 0;
1224
1225 /* If either of these, don't count towards total */
1226 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1227 entry->rule.listnr == AUDIT_FILTER_TYPE)
1228 dont_count = 1;
1229 #endif
1230
1231 if (inode_f) {
1232 h = audit_hash_ino(inode_f->val);
1233 list = &audit_inode_hash[h];
1234 }
1235
1236 mutex_lock(&audit_filter_mutex);
1237 e = audit_find_rule(entry, list);
1238 mutex_unlock(&audit_filter_mutex);
1239 if (e) {
1240 err = -EEXIST;
1241 goto error;
1242 }
1243
1244 /* Avoid calling path_lookup under audit_filter_mutex. */
1245 if (watch) {
1246 err = audit_get_nd(watch->path, &ndp, &ndw);
1247 if (err)
1248 goto error;
1249 }
1250
1251 mutex_lock(&audit_filter_mutex);
1252 if (watch) {
1253 /* audit_filter_mutex is dropped and re-taken during this call */
1254 err = audit_add_watch(&entry->rule, ndp, ndw);
1255 if (err) {
1256 mutex_unlock(&audit_filter_mutex);
1257 goto error;
1258 }
1259 h = audit_hash_ino((u32)watch->ino);
1260 list = &audit_inode_hash[h];
1261 }
1262
1263 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1264 list_add_rcu(&entry->list, list);
1265 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1266 } else {
1267 list_add_tail_rcu(&entry->list, list);
1268 }
1269 #ifdef CONFIG_AUDITSYSCALL
1270 if (!dont_count)
1271 audit_n_rules++;
1272
1273 if (!audit_match_signal(entry))
1274 audit_signals++;
1275 #endif
1276 mutex_unlock(&audit_filter_mutex);
1277
1278 audit_put_nd(ndp, ndw); /* NULL args OK */
1279 return 0;
1280
1281 error:
1282 audit_put_nd(ndp, ndw); /* NULL args OK */
1283 if (watch)
1284 audit_put_watch(watch); /* tmp watch, matches initial get */
1285 return err;
1286 }
1287
1288 /* Remove an existing rule from filterlist. */
1289 static inline int audit_del_rule(struct audit_entry *entry,
1290 struct list_head *list)
1291 {
1292 struct audit_entry *e;
1293 struct audit_field *inode_f = entry->rule.inode_f;
1294 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1295 LIST_HEAD(inotify_list);
1296 int h, ret = 0;
1297 #ifdef CONFIG_AUDITSYSCALL
1298 int dont_count = 0;
1299
1300 /* If either of these, don't count towards total */
1301 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1302 entry->rule.listnr == AUDIT_FILTER_TYPE)
1303 dont_count = 1;
1304 #endif
1305
1306 if (inode_f) {
1307 h = audit_hash_ino(inode_f->val);
1308 list = &audit_inode_hash[h];
1309 }
1310
1311 mutex_lock(&audit_filter_mutex);
1312 e = audit_find_rule(entry, list);
1313 if (!e) {
1314 mutex_unlock(&audit_filter_mutex);
1315 ret = -ENOENT;
1316 goto out;
1317 }
1318
1319 watch = e->rule.watch;
1320 if (watch) {
1321 struct audit_parent *parent = watch->parent;
1322
1323 list_del(&e->rule.rlist);
1324
1325 if (list_empty(&watch->rules)) {
1326 audit_remove_watch(watch);
1327
1328 if (list_empty(&parent->watches)) {
1329 /* Put parent on the inotify un-registration
1330 * list. Grab a reference before releasing
1331 * audit_filter_mutex, to be released in
1332 * audit_inotify_unregister(). */
1333 list_add(&parent->ilist, &inotify_list);
1334 get_inotify_watch(&parent->wdata);
1335 }
1336 }
1337 }
1338
1339 list_del_rcu(&e->list);
1340 call_rcu(&e->rcu, audit_free_rule_rcu);
1341
1342 #ifdef CONFIG_AUDITSYSCALL
1343 if (!dont_count)
1344 audit_n_rules--;
1345
1346 if (!audit_match_signal(entry))
1347 audit_signals--;
1348 #endif
1349 mutex_unlock(&audit_filter_mutex);
1350
1351 if (!list_empty(&inotify_list))
1352 audit_inotify_unregister(&inotify_list);
1353
1354 out:
1355 if (tmp_watch)
1356 audit_put_watch(tmp_watch); /* match initial get */
1357
1358 return ret;
1359 }
1360
1361 /* List rules using struct audit_rule. Exists for backward
1362 * compatibility with userspace. */
1363 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1364 {
1365 struct sk_buff *skb;
1366 struct audit_entry *entry;
1367 int i;
1368
1369 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1370 * iterator to sync with list writers. */
1371 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1372 list_for_each_entry(entry, &audit_filter_list[i], list) {
1373 struct audit_rule *rule;
1374
1375 rule = audit_krule_to_rule(&entry->rule);
1376 if (unlikely(!rule))
1377 break;
1378 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1379 rule, sizeof(*rule));
1380 if (skb)
1381 skb_queue_tail(q, skb);
1382 kfree(rule);
1383 }
1384 }
1385 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1386 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1387 struct audit_rule *rule;
1388
1389 rule = audit_krule_to_rule(&entry->rule);
1390 if (unlikely(!rule))
1391 break;
1392 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1393 rule, sizeof(*rule));
1394 if (skb)
1395 skb_queue_tail(q, skb);
1396 kfree(rule);
1397 }
1398 }
1399 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1400 if (skb)
1401 skb_queue_tail(q, skb);
1402 }
1403
1404 /* List rules using struct audit_rule_data. */
1405 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1406 {
1407 struct sk_buff *skb;
1408 struct audit_entry *e;
1409 int i;
1410
1411 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1412 * iterator to sync with list writers. */
1413 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1414 list_for_each_entry(e, &audit_filter_list[i], list) {
1415 struct audit_rule_data *data;
1416
1417 data = audit_krule_to_data(&e->rule);
1418 if (unlikely(!data))
1419 break;
1420 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1421 data, sizeof(*data) + data->buflen);
1422 if (skb)
1423 skb_queue_tail(q, skb);
1424 kfree(data);
1425 }
1426 }
1427 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1428 list_for_each_entry(e, &audit_inode_hash[i], list) {
1429 struct audit_rule_data *data;
1430
1431 data = audit_krule_to_data(&e->rule);
1432 if (unlikely(!data))
1433 break;
1434 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1435 data, sizeof(*data) + data->buflen);
1436 if (skb)
1437 skb_queue_tail(q, skb);
1438 kfree(data);
1439 }
1440 }
1441 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1442 if (skb)
1443 skb_queue_tail(q, skb);
1444 }
1445
1446 /* Log rule additions and removals */
1447 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1448 struct audit_krule *rule, int res)
1449 {
1450 struct audit_buffer *ab;
1451
1452 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1453 if (!ab)
1454 return;
1455 audit_log_format(ab, "auid=%u", loginuid);
1456 if (sid) {
1457 char *ctx = NULL;
1458 u32 len;
1459 if (selinux_sid_to_string(sid, &ctx, &len))
1460 audit_log_format(ab, " ssid=%u", sid);
1461 else
1462 audit_log_format(ab, " subj=%s", ctx);
1463 kfree(ctx);
1464 }
1465 audit_log_format(ab, " op=%s rule key=", action);
1466 if (rule->filterkey)
1467 audit_log_untrustedstring(ab, rule->filterkey);
1468 else
1469 audit_log_format(ab, "(null)");
1470 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1471 audit_log_end(ab);
1472 }
1473
1474 /**
1475 * audit_receive_filter - apply all rules to the specified message type
1476 * @type: audit message type
1477 * @pid: target pid for netlink audit messages
1478 * @uid: target uid for netlink audit messages
1479 * @seq: netlink audit message sequence (serial) number
1480 * @data: payload data
1481 * @datasz: size of payload data
1482 * @loginuid: loginuid of sender
1483 * @sid: SE Linux Security ID of sender
1484 */
1485 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1486 size_t datasz, uid_t loginuid, u32 sid)
1487 {
1488 struct task_struct *tsk;
1489 struct audit_netlink_list *dest;
1490 int err = 0;
1491 struct audit_entry *entry;
1492
1493 switch (type) {
1494 case AUDIT_LIST:
1495 case AUDIT_LIST_RULES:
1496 /* We can't just spew out the rules here because we might fill
1497 * the available socket buffer space and deadlock waiting for
1498 * auditctl to read from it... which isn't ever going to
1499 * happen if we're actually running in the context of auditctl
1500 * trying to _send_ the stuff */
1501
1502 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1503 if (!dest)
1504 return -ENOMEM;
1505 dest->pid = pid;
1506 skb_queue_head_init(&dest->q);
1507
1508 mutex_lock(&audit_filter_mutex);
1509 if (type == AUDIT_LIST)
1510 audit_list(pid, seq, &dest->q);
1511 else
1512 audit_list_rules(pid, seq, &dest->q);
1513 mutex_unlock(&audit_filter_mutex);
1514
1515 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1516 if (IS_ERR(tsk)) {
1517 skb_queue_purge(&dest->q);
1518 kfree(dest);
1519 err = PTR_ERR(tsk);
1520 }
1521 break;
1522 case AUDIT_ADD:
1523 case AUDIT_ADD_RULE:
1524 if (type == AUDIT_ADD)
1525 entry = audit_rule_to_entry(data);
1526 else
1527 entry = audit_data_to_entry(data, datasz);
1528 if (IS_ERR(entry))
1529 return PTR_ERR(entry);
1530
1531 err = audit_add_rule(entry,
1532 &audit_filter_list[entry->rule.listnr]);
1533 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1534
1535 if (err)
1536 audit_free_rule(entry);
1537 break;
1538 case AUDIT_DEL:
1539 case AUDIT_DEL_RULE:
1540 if (type == AUDIT_DEL)
1541 entry = audit_rule_to_entry(data);
1542 else
1543 entry = audit_data_to_entry(data, datasz);
1544 if (IS_ERR(entry))
1545 return PTR_ERR(entry);
1546
1547 err = audit_del_rule(entry,
1548 &audit_filter_list[entry->rule.listnr]);
1549 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1550 !err);
1551
1552 audit_free_rule(entry);
1553 break;
1554 default:
1555 return -EINVAL;
1556 }
1557
1558 return err;
1559 }
1560
1561 int audit_comparator(const u32 left, const u32 op, const u32 right)
1562 {
1563 switch (op) {
1564 case AUDIT_EQUAL:
1565 return (left == right);
1566 case AUDIT_NOT_EQUAL:
1567 return (left != right);
1568 case AUDIT_LESS_THAN:
1569 return (left < right);
1570 case AUDIT_LESS_THAN_OR_EQUAL:
1571 return (left <= right);
1572 case AUDIT_GREATER_THAN:
1573 return (left > right);
1574 case AUDIT_GREATER_THAN_OR_EQUAL:
1575 return (left >= right);
1576 case AUDIT_BIT_MASK:
1577 return (left & right);
1578 case AUDIT_BIT_TEST:
1579 return ((left & right) == right);
1580 }
1581 BUG();
1582 return 0;
1583 }
1584
1585 /* Compare given dentry name with last component in given path,
1586 * return of 0 indicates a match. */
1587 int audit_compare_dname_path(const char *dname, const char *path,
1588 int *dirlen)
1589 {
1590 int dlen, plen;
1591 const char *p;
1592
1593 if (!dname || !path)
1594 return 1;
1595
1596 dlen = strlen(dname);
1597 plen = strlen(path);
1598 if (plen < dlen)
1599 return 1;
1600
1601 /* disregard trailing slashes */
1602 p = path + plen - 1;
1603 while ((*p == '/') && (p > path))
1604 p--;
1605
1606 /* find last path component */
1607 p = p - dlen + 1;
1608 if (p < path)
1609 return 1;
1610 else if (p > path) {
1611 if (*--p != '/')
1612 return 1;
1613 else
1614 p++;
1615 }
1616
1617 /* return length of path's directory component */
1618 if (dirlen)
1619 *dirlen = p - path;
1620 return strncmp(p, dname, dlen);
1621 }
1622
1623 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1624 struct audit_krule *rule,
1625 enum audit_state *state)
1626 {
1627 int i;
1628
1629 for (i = 0; i < rule->field_count; i++) {
1630 struct audit_field *f = &rule->fields[i];
1631 int result = 0;
1632
1633 switch (f->type) {
1634 case AUDIT_PID:
1635 result = audit_comparator(cb->creds.pid, f->op, f->val);
1636 break;
1637 case AUDIT_UID:
1638 result = audit_comparator(cb->creds.uid, f->op, f->val);
1639 break;
1640 case AUDIT_GID:
1641 result = audit_comparator(cb->creds.gid, f->op, f->val);
1642 break;
1643 case AUDIT_LOGINUID:
1644 result = audit_comparator(cb->loginuid, f->op, f->val);
1645 break;
1646 }
1647
1648 if (!result)
1649 return 0;
1650 }
1651 switch (rule->action) {
1652 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1653 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1654 }
1655 return 1;
1656 }
1657
1658 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1659 {
1660 enum audit_state state = AUDIT_DISABLED;
1661 struct audit_entry *e;
1662 int ret = 1;
1663
1664 rcu_read_lock();
1665 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1666 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1667 if (state == AUDIT_DISABLED)
1668 ret = 0;
1669 break;
1670 }
1671 }
1672 rcu_read_unlock();
1673
1674 return ret; /* Audit by default */
1675 }
1676
1677 int audit_filter_type(int type)
1678 {
1679 struct audit_entry *e;
1680 int result = 0;
1681
1682 rcu_read_lock();
1683 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1684 goto unlock_and_return;
1685
1686 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1687 list) {
1688 int i;
1689 for (i = 0; i < e->rule.field_count; i++) {
1690 struct audit_field *f = &e->rule.fields[i];
1691 if (f->type == AUDIT_MSGTYPE) {
1692 result = audit_comparator(type, f->op, f->val);
1693 if (!result)
1694 break;
1695 }
1696 }
1697 if (result)
1698 goto unlock_and_return;
1699 }
1700 unlock_and_return:
1701 rcu_read_unlock();
1702 return result;
1703 }
1704
1705 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1706 are selinux fields specified in the rule, 0 otherwise. */
1707 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1708 {
1709 int i;
1710
1711 for (i = 0; i < rule->field_count; i++) {
1712 struct audit_field *f = &rule->fields[i];
1713 switch (f->type) {
1714 case AUDIT_SUBJ_USER:
1715 case AUDIT_SUBJ_ROLE:
1716 case AUDIT_SUBJ_TYPE:
1717 case AUDIT_SUBJ_SEN:
1718 case AUDIT_SUBJ_CLR:
1719 case AUDIT_OBJ_USER:
1720 case AUDIT_OBJ_ROLE:
1721 case AUDIT_OBJ_TYPE:
1722 case AUDIT_OBJ_LEV_LOW:
1723 case AUDIT_OBJ_LEV_HIGH:
1724 return 1;
1725 }
1726 }
1727
1728 return 0;
1729 }
1730
1731 /* This function will re-initialize the se_rule field of all applicable rules.
1732 * It will traverse the filter lists serarching for rules that contain selinux
1733 * specific filter fields. When such a rule is found, it is copied, the
1734 * selinux field is re-initialized, and the old rule is replaced with the
1735 * updated rule. */
1736 int selinux_audit_rule_update(void)
1737 {
1738 struct audit_entry *entry, *n, *nentry;
1739 struct audit_watch *watch;
1740 int i, err = 0;
1741
1742 /* audit_filter_mutex synchronizes the writers */
1743 mutex_lock(&audit_filter_mutex);
1744
1745 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1746 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1747 if (!audit_rule_has_selinux(&entry->rule))
1748 continue;
1749
1750 watch = entry->rule.watch;
1751 nentry = audit_dupe_rule(&entry->rule, watch);
1752 if (unlikely(IS_ERR(nentry))) {
1753 /* save the first error encountered for the
1754 * return value */
1755 if (!err)
1756 err = PTR_ERR(nentry);
1757 audit_panic("error updating selinux filters");
1758 if (watch)
1759 list_del(&entry->rule.rlist);
1760 list_del_rcu(&entry->list);
1761 } else {
1762 if (watch) {
1763 list_add(&nentry->rule.rlist,
1764 &watch->rules);
1765 list_del(&entry->rule.rlist);
1766 }
1767 list_replace_rcu(&entry->list, &nentry->list);
1768 }
1769 call_rcu(&entry->rcu, audit_free_rule_rcu);
1770 }
1771 }
1772
1773 mutex_unlock(&audit_filter_mutex);
1774
1775 return err;
1776 }
1777
1778 /* Update watch data in audit rules based on inotify events. */
1779 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1780 u32 cookie, const char *dname, struct inode *inode)
1781 {
1782 struct audit_parent *parent;
1783
1784 parent = container_of(i_watch, struct audit_parent, wdata);
1785
1786 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1787 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1788 inode->i_ino, 0);
1789 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1790 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1791 /* inotify automatically removes the watch and sends IN_IGNORED */
1792 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1793 audit_remove_parent_watches(parent);
1794 /* inotify does not remove the watch, so remove it manually */
1795 else if(mask & IN_MOVE_SELF) {
1796 audit_remove_parent_watches(parent);
1797 inotify_remove_watch_locked(audit_ih, i_watch);
1798 } else if (mask & IN_IGNORED)
1799 put_inotify_watch(i_watch);
1800 }
kmemtrace - Kernel memory tracer