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[PATCH] fix audit oops with invalid operator
[linux-block.git] / kernel / auditfilter.c
CommitLineData
fe7752ba
DW		 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>
f368c07d
AG		 25#include <linux/mutex.h>
26#include <linux/fs.h>
27#include <linux/namei.h>
fe7752ba 28#include <linux/netlink.h>
f368c07d
AG		 29#include <linux/sched.h>
30#include <linux/inotify.h>
3dc7e315 31#include <linux/selinux.h>
fe7752ba
DW		 32#include "audit.h"
33
f368c07d
AG		 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
59struct 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> */
fe7752ba
DW		 78struct 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
f368c07d
AG		 90static DEFINE_MUTEX(audit_filter_mutex);
91
92/* Inotify handle */
93extern 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
98void 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
107static inline void audit_get_watch(struct audit_watch *watch)
108{
109 atomic_inc(&watch->count);
110}
111
112static 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
122static 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
93315ed6 130static inline void audit_free_rule(struct audit_entry *e)
fe7752ba 131{
3dc7e315 132 int i;
f368c07d
AG		 133
134 /* some rules don't have associated watches */
135 if (e->rule.watch)
136 audit_put_watch(e->rule.watch);
3dc7e315
DG		 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 }
93315ed6 143 kfree(e->rule.fields);
5adc8a6a 144 kfree(e->rule.filterkey);
93315ed6
AG		 145 kfree(e);
146}
147
148static 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
f368c07d
AG		 154/* Initialize a parent watch entry. */
155static 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. */
181static 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
3dc7e315
DG		 198/* Initialize an audit filterlist entry. */
199static 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
93315ed6
AG		 218/* Unpack a filter field's string representation from user-space
219 * buffer. */
3dc7e315 220static char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
93315ed6
AG		 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
f368c07d
AG		 245/* Translate an inode field to kernel respresentation. */
246static 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. */
258static 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
b915543b
AV		 282static __u32 *classes[AUDIT_SYSCALL_CLASSES];
283
284int __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
93315ed6
AG		 305/* Common user-space to kernel rule translation. */
306static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
307{
308 unsigned listnr;
309 struct audit_entry *entry;
93315ed6
AG		 310 int i, err;
311
312 err = -EINVAL;
313 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
314 switch(listnr) {
315 default:
316 goto exit_err;
317 case AUDIT_FILTER_USER:
318 case AUDIT_FILTER_TYPE:
319#ifdef CONFIG_AUDITSYSCALL
320 case AUDIT_FILTER_ENTRY:
321 case AUDIT_FILTER_EXIT:
322 case AUDIT_FILTER_TASK:
323#endif
324 ;
325 }
014149cc
AV		 326 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
327 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
328 goto exit_err;
329 }
330 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
93315ed6
AG		 331 goto exit_err;
332 if (rule->field_count > AUDIT_MAX_FIELDS)
333 goto exit_err;
334
335 err = -ENOMEM;
3dc7e315
DG		 336 entry = audit_init_entry(rule->field_count);
337 if (!entry)
93315ed6 338 goto exit_err;
93315ed6
AG		 339
340 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
341 entry->rule.listnr = listnr;
342 entry->rule.action = rule->action;
343 entry->rule.field_count = rule->field_count;
93315ed6
AG		 344
345 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
346 entry->rule.mask[i] = rule->mask[i];
347
b915543b
AV		 348 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
349 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
350 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
351 __u32 *class;
352
353 if (!(*p & AUDIT_BIT(bit)))
354 continue;
355 *p &= ~AUDIT_BIT(bit);
356 class = classes[i];
357 if (class) {
358 int j;
359 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
360 entry->rule.mask[j] |= class[j];
361 }
362 }
363
93315ed6
AG		 364 return entry;
365
366exit_err:
367 return ERR_PTR(err);
368}
369
370/* Translate struct audit_rule to kernel's rule respresentation.
371 * Exists for backward compatibility with userspace. */
372static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
373{
374 struct audit_entry *entry;
f368c07d 375 struct audit_field *f;
93315ed6 376 int err = 0;
fe7752ba
DW		 377 int i;
378
93315ed6
AG		 379 entry = audit_to_entry_common(rule);
380 if (IS_ERR(entry))
381 goto exit_nofree;
382
383 for (i = 0; i < rule->field_count; i++) {
384 struct audit_field *f = &entry->rule.fields[i];
385
93315ed6
AG		 386 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
387 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
388 f->val = rule->values[i];
389
f368c07d 390 err = -EINVAL;
f368c07d 391 switch(f->type) {
0a73dccc 392 default:
3dc7e315 393 goto exit_free;
0a73dccc
AV		 394 case AUDIT_PID:
395 case AUDIT_UID:
396 case AUDIT_EUID:
397 case AUDIT_SUID:
398 case AUDIT_FSUID:
399 case AUDIT_GID:
400 case AUDIT_EGID:
401 case AUDIT_SGID:
402 case AUDIT_FSGID:
403 case AUDIT_LOGINUID:
404 case AUDIT_PERS:
405 case AUDIT_ARCH:
406 case AUDIT_MSGTYPE:
407 case AUDIT_DEVMAJOR:
408 case AUDIT_DEVMINOR:
409 case AUDIT_EXIT:
410 case AUDIT_SUCCESS:
411 case AUDIT_ARG0:
412 case AUDIT_ARG1:
413 case AUDIT_ARG2:
414 case AUDIT_ARG3:
415 break;
f368c07d
AG		 416 case AUDIT_INODE:
417 err = audit_to_inode(&entry->rule, f);
418 if (err)
419 goto exit_free;
420 break;
3dc7e315
DG		 421 }
422
93315ed6 423 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
d9d9ec6e
DK		 424
425 /* Support for legacy operators where
426 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
93315ed6 427 if (f->op & AUDIT_NEGATE)
d9d9ec6e
DK		 428 f->op = AUDIT_NOT_EQUAL;
429 else if (!f->op)
430 f->op = AUDIT_EQUAL;
431 else if (f->op == AUDIT_OPERATORS) {
432 err = -EINVAL;
433 goto exit_free;
434 }
fe7752ba 435 }
93315ed6 436
f368c07d
AG		 437 f = entry->rule.inode_f;
438 if (f) {
439 switch(f->op) {
440 case AUDIT_NOT_EQUAL:
441 entry->rule.inode_f = NULL;
442 case AUDIT_EQUAL:
443 break;
444 default:
5422e01a 445 err = -EINVAL;
f368c07d
AG		 446 goto exit_free;
447 }
448 }
449
93315ed6
AG		 450exit_nofree:
451 return entry;
452
453exit_free:
454 audit_free_rule(entry);
455 return ERR_PTR(err);
fe7752ba
DW		 456}
457
93315ed6
AG		 458/* Translate struct audit_rule_data to kernel's rule respresentation. */
459static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
460 size_t datasz)
fe7752ba 461{
93315ed6
AG		 462 int err = 0;
463 struct audit_entry *entry;
f368c07d 464 struct audit_field *f;
93315ed6 465 void *bufp;
3dc7e315 466 size_t remain = datasz - sizeof(struct audit_rule_data);
fe7752ba 467 int i;
3dc7e315 468 char *str;
fe7752ba 469
93315ed6
AG		 470 entry = audit_to_entry_common((struct audit_rule *)data);
471 if (IS_ERR(entry))
472 goto exit_nofree;
fe7752ba 473
93315ed6
AG		 474 bufp = data->buf;
475 entry->rule.vers_ops = 2;
476 for (i = 0; i < data->field_count; i++) {
477 struct audit_field *f = &entry->rule.fields[i];
478
479 err = -EINVAL;
480 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
481 data->fieldflags[i] & ~AUDIT_OPERATORS)
482 goto exit_free;
483
484 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
485 f->type = data->fields[i];
3dc7e315
DG		 486 f->val = data->values[i];
487 f->se_str = NULL;
488 f->se_rule = NULL;
93315ed6 489 switch(f->type) {
0a73dccc
AV		 490 case AUDIT_PID:
491 case AUDIT_UID:
492 case AUDIT_EUID:
493 case AUDIT_SUID:
494 case AUDIT_FSUID:
495 case AUDIT_GID:
496 case AUDIT_EGID:
497 case AUDIT_SGID:
498 case AUDIT_FSGID:
499 case AUDIT_LOGINUID:
500 case AUDIT_PERS:
501 case AUDIT_ARCH:
502 case AUDIT_MSGTYPE:
503 case AUDIT_PPID:
504 case AUDIT_DEVMAJOR:
505 case AUDIT_DEVMINOR:
506 case AUDIT_EXIT:
507 case AUDIT_SUCCESS:
508 case AUDIT_ARG0:
509 case AUDIT_ARG1:
510 case AUDIT_ARG2:
511 case AUDIT_ARG3:
512 break;
3a6b9f85
DG		 513 case AUDIT_SUBJ_USER:
514 case AUDIT_SUBJ_ROLE:
515 case AUDIT_SUBJ_TYPE:
516 case AUDIT_SUBJ_SEN:
517 case AUDIT_SUBJ_CLR:
6e5a2d1d
DG		 518 case AUDIT_OBJ_USER:
519 case AUDIT_OBJ_ROLE:
520 case AUDIT_OBJ_TYPE:
521 case AUDIT_OBJ_LEV_LOW:
522 case AUDIT_OBJ_LEV_HIGH:
3dc7e315
DG		 523 str = audit_unpack_string(&bufp, &remain, f->val);
524 if (IS_ERR(str))
525 goto exit_free;
526 entry->rule.buflen += f->val;
527
528 err = selinux_audit_rule_init(f->type, f->op, str,
529 &f->se_rule);
530 /* Keep currently invalid fields around in case they
531 * become valid after a policy reload. */
532 if (err == -EINVAL) {
533 printk(KERN_WARNING "audit rule for selinux "
534 "\'%s\' is invalid\n", str);
535 err = 0;
536 }
537 if (err) {
538 kfree(str);
539 goto exit_free;
540 } else
541 f->se_str = str;
542 break;
f368c07d
AG		 543 case AUDIT_WATCH:
544 str = audit_unpack_string(&bufp, &remain, f->val);
545 if (IS_ERR(str))
546 goto exit_free;
547 entry->rule.buflen += f->val;
548
549 err = audit_to_watch(&entry->rule, str, f->val, f->op);
550 if (err) {
551 kfree(str);
552 goto exit_free;
553 }
554 break;
555 case AUDIT_INODE:
556 err = audit_to_inode(&entry->rule, f);
557 if (err)
558 goto exit_free;
559 break;
5adc8a6a
AG		 560 case AUDIT_FILTERKEY:
561 err = -EINVAL;
562 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
563 goto exit_free;
564 str = audit_unpack_string(&bufp, &remain, f->val);
565 if (IS_ERR(str))
566 goto exit_free;
567 entry->rule.buflen += f->val;
568 entry->rule.filterkey = str;
569 break;
0a73dccc
AV		 570 default:
571 goto exit_free;
f368c07d
AG		 572 }
573 }
574
575 f = entry->rule.inode_f;
576 if (f) {
577 switch(f->op) {
578 case AUDIT_NOT_EQUAL:
579 entry->rule.inode_f = NULL;
580 case AUDIT_EQUAL:
581 break;
582 default:
5422e01a 583 err = -EINVAL;
f368c07d 584 goto exit_free;
93315ed6
AG		 585 }
586 }
587
588exit_nofree:
589 return entry;
590
591exit_free:
592 audit_free_rule(entry);
593 return ERR_PTR(err);
594}
595
596/* Pack a filter field's string representation into data block. */
597static inline size_t audit_pack_string(void **bufp, char *str)
598{
599 size_t len = strlen(str);
600
601 memcpy(*bufp, str, len);
602 *bufp += len;
603
604 return len;
605}
606
607/* Translate kernel rule respresentation to struct audit_rule.
608 * Exists for backward compatibility with userspace. */
609static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
610{
611 struct audit_rule *rule;
612 int i;
613
614 rule = kmalloc(sizeof(*rule), GFP_KERNEL);
615 if (unlikely(!rule))
0a3b483e 616 return NULL;
93315ed6
AG		 617 memset(rule, 0, sizeof(*rule));
618
619 rule->flags = krule->flags | krule->listnr;
620 rule->action = krule->action;
621 rule->field_count = krule->field_count;
622 for (i = 0; i < rule->field_count; i++) {
623 rule->values[i] = krule->fields[i].val;
624 rule->fields[i] = krule->fields[i].type;
625
626 if (krule->vers_ops == 1) {
627 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
628 rule->fields[i] |= AUDIT_NEGATE;
629 } else {
630 rule->fields[i] |= krule->fields[i].op;
631 }
632 }
633 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
634
635 return rule;
636}
fe7752ba 637
93315ed6
AG		 638/* Translate kernel rule respresentation to struct audit_rule_data. */
639static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
640{
641 struct audit_rule_data *data;
642 void *bufp;
643 int i;
644
645 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
646 if (unlikely(!data))
0a3b483e 647 return NULL;
93315ed6
AG		 648 memset(data, 0, sizeof(*data));
649
650 data->flags = krule->flags | krule->listnr;
651 data->action = krule->action;
652 data->field_count = krule->field_count;
653 bufp = data->buf;
654 for (i = 0; i < data->field_count; i++) {
655 struct audit_field *f = &krule->fields[i];
656
657 data->fields[i] = f->type;
658 data->fieldflags[i] = f->op;
659 switch(f->type) {
3a6b9f85
DG		 660 case AUDIT_SUBJ_USER:
661 case AUDIT_SUBJ_ROLE:
662 case AUDIT_SUBJ_TYPE:
663 case AUDIT_SUBJ_SEN:
664 case AUDIT_SUBJ_CLR:
6e5a2d1d
DG		 665 case AUDIT_OBJ_USER:
666 case AUDIT_OBJ_ROLE:
667 case AUDIT_OBJ_TYPE:
668 case AUDIT_OBJ_LEV_LOW:
669 case AUDIT_OBJ_LEV_HIGH:
3dc7e315
DG		 670 data->buflen += data->values[i] =
671 audit_pack_string(&bufp, f->se_str);
672 break;
f368c07d
AG		 673 case AUDIT_WATCH:
674 data->buflen += data->values[i] =
675 audit_pack_string(&bufp, krule->watch->path);
676 break;
5adc8a6a
AG		 677 case AUDIT_FILTERKEY:
678 data->buflen += data->values[i] =
679 audit_pack_string(&bufp, krule->filterkey);
680 break;
93315ed6
AG		 681 default:
682 data->values[i] = f->val;
683 }
684 }
685 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
686
687 return data;
688}
689
690/* Compare two rules in kernel format. Considered success if rules
691 * don't match. */
692static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
693{
694 int i;
695
696 if (a->flags != b->flags ||
697 a->listnr != b->listnr ||
698 a->action != b->action ||
699 a->field_count != b->field_count)
fe7752ba
DW		 700 return 1;
701
702 for (i = 0; i < a->field_count; i++) {
93315ed6
AG		 703 if (a->fields[i].type != b->fields[i].type ||
704 a->fields[i].op != b->fields[i].op)
fe7752ba 705 return 1;
93315ed6
AG		 706
707 switch(a->fields[i].type) {
3a6b9f85
DG		 708 case AUDIT_SUBJ_USER:
709 case AUDIT_SUBJ_ROLE:
710 case AUDIT_SUBJ_TYPE:
711 case AUDIT_SUBJ_SEN:
712 case AUDIT_SUBJ_CLR:
6e5a2d1d
DG		 713 case AUDIT_OBJ_USER:
714 case AUDIT_OBJ_ROLE:
715 case AUDIT_OBJ_TYPE:
716 case AUDIT_OBJ_LEV_LOW:
717 case AUDIT_OBJ_LEV_HIGH:
3dc7e315
DG		 718 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
719 return 1;
720 break;
f368c07d
AG		 721 case AUDIT_WATCH:
722 if (strcmp(a->watch->path, b->watch->path))
723 return 1;
724 break;
5adc8a6a
AG		 725 case AUDIT_FILTERKEY:
726 /* both filterkeys exist based on above type compare */
727 if (strcmp(a->filterkey, b->filterkey))
728 return 1;
729 break;
93315ed6
AG		 730 default:
731 if (a->fields[i].val != b->fields[i].val)
732 return 1;
733 }
fe7752ba
DW		 734 }
735
736 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
737 if (a->mask[i] != b->mask[i])
738 return 1;
739
740 return 0;
741}
742
f368c07d
AG		 743/* Duplicate the given audit watch. The new watch's rules list is initialized
744 * to an empty list and wlist is undefined. */
745static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
746{
747 char *path;
748 struct audit_watch *new;
749
750 path = kstrdup(old->path, GFP_KERNEL);
751 if (unlikely(!path))
752 return ERR_PTR(-ENOMEM);
753
754 new = audit_init_watch(path);
755 if (unlikely(IS_ERR(new))) {
756 kfree(path);
757 goto out;
758 }
759
760 new->dev = old->dev;
761 new->ino = old->ino;
762 get_inotify_watch(&old->parent->wdata);
763 new->parent = old->parent;
764
765out:
766 return new;
767}
768
3dc7e315
DG		 769/* Duplicate selinux field information. The se_rule is opaque, so must be
770 * re-initialized. */
771static inline int audit_dupe_selinux_field(struct audit_field *df,
772 struct audit_field *sf)
773{
774 int ret = 0;
775 char *se_str;
776
777 /* our own copy of se_str */
778 se_str = kstrdup(sf->se_str, GFP_KERNEL);
779 if (unlikely(IS_ERR(se_str)))
780 return -ENOMEM;
781 df->se_str = se_str;
782
783 /* our own (refreshed) copy of se_rule */
784 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
785 &df->se_rule);
786 /* Keep currently invalid fields around in case they
787 * become valid after a policy reload. */
788 if (ret == -EINVAL) {
789 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
790 "invalid\n", df->se_str);
791 ret = 0;
792 }
793
794 return ret;
795}
796
797/* Duplicate an audit rule. This will be a deep copy with the exception
798 * of the watch - that pointer is carried over. The selinux specific fields
799 * will be updated in the copy. The point is to be able to replace the old
f368c07d
AG		 800 * rule with the new rule in the filterlist, then free the old rule.
801 * The rlist element is undefined; list manipulations are handled apart from
802 * the initial copy. */
803static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
804 struct audit_watch *watch)
3dc7e315
DG		 805{
806 u32 fcount = old->field_count;
807 struct audit_entry *entry;
808 struct audit_krule *new;
5adc8a6a 809 char *fk;
3dc7e315
DG		 810 int i, err = 0;
811
812 entry = audit_init_entry(fcount);
813 if (unlikely(!entry))
814 return ERR_PTR(-ENOMEM);
815
816 new = &entry->rule;
817 new->vers_ops = old->vers_ops;
818 new->flags = old->flags;
819 new->listnr = old->listnr;
820 new->action = old->action;
821 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
822 new->mask[i] = old->mask[i];
823 new->buflen = old->buflen;
f368c07d
AG		 824 new->inode_f = old->inode_f;
825 new->watch = NULL;
3dc7e315
DG		 826 new->field_count = old->field_count;
827 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
828
829 /* deep copy this information, updating the se_rule fields, because
830 * the originals will all be freed when the old rule is freed. */
831 for (i = 0; i < fcount; i++) {
832 switch (new->fields[i].type) {
3a6b9f85
DG		 833 case AUDIT_SUBJ_USER:
834 case AUDIT_SUBJ_ROLE:
835 case AUDIT_SUBJ_TYPE:
836 case AUDIT_SUBJ_SEN:
837 case AUDIT_SUBJ_CLR:
6e5a2d1d
DG		 838 case AUDIT_OBJ_USER:
839 case AUDIT_OBJ_ROLE:
840 case AUDIT_OBJ_TYPE:
841 case AUDIT_OBJ_LEV_LOW:
842 case AUDIT_OBJ_LEV_HIGH:
3dc7e315
DG		 843 err = audit_dupe_selinux_field(&new->fields[i],
844 &old->fields[i]);
5adc8a6a
AG		 845 break;
846 case AUDIT_FILTERKEY:
847 fk = kstrdup(old->filterkey, GFP_KERNEL);
848 if (unlikely(!fk))
849 err = -ENOMEM;
850 else
851 new->filterkey = fk;
3dc7e315
DG		 852 }
853 if (err) {
854 audit_free_rule(entry);
855 return ERR_PTR(err);
856 }
857 }
858
f368c07d
AG		 859 if (watch) {
860 audit_get_watch(watch);
861 new->watch = watch;
862 }
863
3dc7e315
DG		 864 return entry;
865}
866
f368c07d
AG		 867/* Update inode info in audit rules based on filesystem event. */
868static void audit_update_watch(struct audit_parent *parent,
869 const char *dname, dev_t dev,
870 unsigned long ino, unsigned invalidating)
871{
872 struct audit_watch *owatch, *nwatch, *nextw;
873 struct audit_krule *r, *nextr;
874 struct audit_entry *oentry, *nentry;
875 struct audit_buffer *ab;
876
877 mutex_lock(&audit_filter_mutex);
878 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
9c937dcc 879 if (audit_compare_dname_path(dname, owatch->path, NULL))
f368c07d
AG		 880 continue;
881
882 /* If the update involves invalidating rules, do the inode-based
883 * filtering now, so we don't omit records. */
884 if (invalidating &&
885 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
886 audit_set_auditable(current->audit_context);
887
888 nwatch = audit_dupe_watch(owatch);
889 if (unlikely(IS_ERR(nwatch))) {
890 mutex_unlock(&audit_filter_mutex);
891 audit_panic("error updating watch, skipping");
892 return;
893 }
894 nwatch->dev = dev;
895 nwatch->ino = ino;
896
897 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
898
899 oentry = container_of(r, struct audit_entry, rule);
900 list_del(&oentry->rule.rlist);
901 list_del_rcu(&oentry->list);
902
903 nentry = audit_dupe_rule(&oentry->rule, nwatch);
904 if (unlikely(IS_ERR(nentry)))
905 audit_panic("error updating watch, removing");
906 else {
907 int h = audit_hash_ino((u32)ino);
908 list_add(&nentry->rule.rlist, &nwatch->rules);
909 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
910 }
911
912 call_rcu(&oentry->rcu, audit_free_rule_rcu);
913 }
914
915 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
916 audit_log_format(ab, "audit updated rules specifying watch=");
917 audit_log_untrustedstring(ab, owatch->path);
918 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
919 audit_log_end(ab);
920
921 audit_remove_watch(owatch);
922 goto add_watch_to_parent; /* event applies to a single watch */
923 }
924 mutex_unlock(&audit_filter_mutex);
925 return;
926
927add_watch_to_parent:
928 list_add(&nwatch->wlist, &parent->watches);
929 mutex_unlock(&audit_filter_mutex);
930 return;
931}
932
933/* Remove all watches & rules associated with a parent that is going away. */
934static void audit_remove_parent_watches(struct audit_parent *parent)
935{
936 struct audit_watch *w, *nextw;
937 struct audit_krule *r, *nextr;
938 struct audit_entry *e;
939
940 mutex_lock(&audit_filter_mutex);
941 parent->flags |= AUDIT_PARENT_INVALID;
942 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
943 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
944 e = container_of(r, struct audit_entry, rule);
945 list_del(&r->rlist);
946 list_del_rcu(&e->list);
947 call_rcu(&e->rcu, audit_free_rule_rcu);
948
949 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
950 "audit implicitly removed rule from list=%d\n",
951 AUDIT_FILTER_EXIT);
952 }
953 audit_remove_watch(w);
954 }
955 mutex_unlock(&audit_filter_mutex);
956}
957
958/* Unregister inotify watches for parents on in_list.
959 * Generates an IN_IGNORED event. */
960static void audit_inotify_unregister(struct list_head *in_list)
961{
962 struct audit_parent *p, *n;
963
964 list_for_each_entry_safe(p, n, in_list, ilist) {
965 list_del(&p->ilist);
966 inotify_rm_watch(audit_ih, &p->wdata);
967 /* the put matching the get in audit_do_del_rule() */
968 put_inotify_watch(&p->wdata);
969 }
970}
971
972/* Find an existing audit rule.
973 * Caller must hold audit_filter_mutex to prevent stale rule data. */
974static struct audit_entry *audit_find_rule(struct audit_entry *entry,
975 struct list_head *list)
976{
977 struct audit_entry *e, *found = NULL;
978 int h;
979
980 if (entry->rule.watch) {
981 /* we don't know the inode number, so must walk entire hash */
982 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
983 list = &audit_inode_hash[h];
984 list_for_each_entry(e, list, list)
985 if (!audit_compare_rule(&entry->rule, &e->rule)) {
986 found = e;
987 goto out;
988 }
989 }
990 goto out;
991 }
992
993 list_for_each_entry(e, list, list)
994 if (!audit_compare_rule(&entry->rule, &e->rule)) {
995 found = e;
996 goto out;
997 }
998
999out:
1000 return found;
1001}
1002
1003/* Get path information necessary for adding watches. */
1004static int audit_get_nd(char *path, struct nameidata **ndp,
1005 struct nameidata **ndw)
1006{
1007 struct nameidata *ndparent, *ndwatch;
1008 int err;
1009
1010 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1011 if (unlikely(!ndparent))
1012 return -ENOMEM;
1013
1014 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1015 if (unlikely(!ndwatch)) {
1016 kfree(ndparent);
1017 return -ENOMEM;
1018 }
1019
1020 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1021 if (err) {
1022 kfree(ndparent);
1023 kfree(ndwatch);
1024 return err;
1025 }
1026
1027 err = path_lookup(path, 0, ndwatch);
1028 if (err) {
1029 kfree(ndwatch);
1030 ndwatch = NULL;
1031 }
1032
1033 *ndp = ndparent;
1034 *ndw = ndwatch;
1035
1036 return 0;
1037}
1038
1039/* Release resources used for watch path information. */
1040static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1041{
1042 if (ndp) {
1043 path_release(ndp);
1044 kfree(ndp);
1045 }
1046 if (ndw) {
1047 path_release(ndw);
1048 kfree(ndw);
1049 }
1050}
1051
1052/* Associate the given rule with an existing parent inotify_watch.
1053 * Caller must hold audit_filter_mutex. */
1054static void audit_add_to_parent(struct audit_krule *krule,
1055 struct audit_parent *parent)
1056{
1057 struct audit_watch *w, *watch = krule->watch;
1058 int watch_found = 0;
1059
1060 list_for_each_entry(w, &parent->watches, wlist) {
1061 if (strcmp(watch->path, w->path))
1062 continue;
1063
1064 watch_found = 1;
1065
1066 /* put krule's and initial refs to temporary watch */
1067 audit_put_watch(watch);
1068 audit_put_watch(watch);
1069
1070 audit_get_watch(w);
1071 krule->watch = watch = w;
1072 break;
1073 }
1074
1075 if (!watch_found) {
1076 get_inotify_watch(&parent->wdata);
1077 watch->parent = parent;
1078
1079 list_add(&watch->wlist, &parent->watches);
1080 }
1081 list_add(&krule->rlist, &watch->rules);
1082}
1083
1084/* Find a matching watch entry, or add this one.
1085 * Caller must hold audit_filter_mutex. */
1086static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1087 struct nameidata *ndw)
1088{
1089 struct audit_watch *watch = krule->watch;
1090 struct inotify_watch *i_watch;
1091 struct audit_parent *parent;
1092 int ret = 0;
1093
1094 /* update watch filter fields */
1095 if (ndw) {
1096 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1097 watch->ino = ndw->dentry->d_inode->i_ino;
1098 }
1099
1100 /* The audit_filter_mutex must not be held during inotify calls because
1101 * we hold it during inotify event callback processing. If an existing
1102 * inotify watch is found, inotify_find_watch() grabs a reference before
1103 * returning.
1104 */
1105 mutex_unlock(&audit_filter_mutex);
1106
1107 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1108 parent = audit_init_parent(ndp);
1109 if (IS_ERR(parent)) {
1110 /* caller expects mutex locked */
1111 mutex_lock(&audit_filter_mutex);
1112 return PTR_ERR(parent);
1113 }
1114 } else
1115 parent = container_of(i_watch, struct audit_parent, wdata);
1116
1117 mutex_lock(&audit_filter_mutex);
1118
1119 /* parent was moved before we took audit_filter_mutex */
1120 if (parent->flags & AUDIT_PARENT_INVALID)
1121 ret = -ENOENT;
1122 else
1123 audit_add_to_parent(krule, parent);
1124
1125 /* match get in audit_init_parent or inotify_find_watch */
1126 put_inotify_watch(&parent->wdata);
1127 return ret;
1128}
1129
1130/* Add rule to given filterlist if not a duplicate. */
93315ed6 1131static inline int audit_add_rule(struct audit_entry *entry,
f368c07d 1132 struct list_head *list)
fe7752ba 1133{
93315ed6 1134 struct audit_entry *e;
f368c07d
AG		 1135 struct audit_field *inode_f = entry->rule.inode_f;
1136 struct audit_watch *watch = entry->rule.watch;
1137 struct nameidata *ndp, *ndw;
1138 int h, err, putnd_needed = 0;
1139
1140 if (inode_f) {
1141 h = audit_hash_ino(inode_f->val);
1142 list = &audit_inode_hash[h];
1143 }
1144
1145 mutex_lock(&audit_filter_mutex);
1146 e = audit_find_rule(entry, list);
1147 mutex_unlock(&audit_filter_mutex);
1148 if (e) {
1149 err = -EEXIST;
1150 goto error;
1151 }
fe7752ba 1152
f368c07d
AG		 1153 /* Avoid calling path_lookup under audit_filter_mutex. */
1154 if (watch) {
1155 err = audit_get_nd(watch->path, &ndp, &ndw);
1156 if (err)
1157 goto error;
1158 putnd_needed = 1;
1159 }
1160
1161 mutex_lock(&audit_filter_mutex);
1162 if (watch) {
1163 /* audit_filter_mutex is dropped and re-taken during this call */
1164 err = audit_add_watch(&entry->rule, ndp, ndw);
1165 if (err) {
1166 mutex_unlock(&audit_filter_mutex);
1167 goto error;
1168 }
1169 h = audit_hash_ino((u32)watch->ino);
1170 list = &audit_inode_hash[h];
fe7752ba
DW		 1171 }
1172
fe7752ba 1173 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
fe7752ba 1174 list_add_rcu(&entry->list, list);
6a2bceec 1175 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
fe7752ba
DW		 1176 } else {
1177 list_add_tail_rcu(&entry->list, list);
1178 }
f368c07d 1179 mutex_unlock(&audit_filter_mutex);
fe7752ba 1180
f368c07d
AG		 1181 if (putnd_needed)
1182 audit_put_nd(ndp, ndw);
1183
1184 return 0;
1185
1186error:
1187 if (putnd_needed)
1188 audit_put_nd(ndp, ndw);
1189 if (watch)
1190 audit_put_watch(watch); /* tmp watch, matches initial get */
1191 return err;
fe7752ba
DW		 1192}
1193
f368c07d 1194/* Remove an existing rule from filterlist. */
93315ed6 1195static inline int audit_del_rule(struct audit_entry *entry,
fe7752ba
DW		 1196 struct list_head *list)
1197{
1198 struct audit_entry *e;
f368c07d
AG		 1199 struct audit_field *inode_f = entry->rule.inode_f;
1200 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1201 LIST_HEAD(inotify_list);
1202 int h, ret = 0;
1203
1204 if (inode_f) {
1205 h = audit_hash_ino(inode_f->val);
1206 list = &audit_inode_hash[h];
1207 }
fe7752ba 1208
f368c07d
AG		 1209 mutex_lock(&audit_filter_mutex);
1210 e = audit_find_rule(entry, list);
1211 if (!e) {
1212 mutex_unlock(&audit_filter_mutex);
1213 ret = -ENOENT;
1214 goto out;
1215 }
1216
1217 watch = e->rule.watch;
1218 if (watch) {
1219 struct audit_parent *parent = watch->parent;
1220
1221 list_del(&e->rule.rlist);
1222
1223 if (list_empty(&watch->rules)) {
1224 audit_remove_watch(watch);
1225
1226 if (list_empty(&parent->watches)) {
1227 /* Put parent on the inotify un-registration
1228 * list. Grab a reference before releasing
1229 * audit_filter_mutex, to be released in
1230 * audit_inotify_unregister(). */
1231 list_add(&parent->ilist, &inotify_list);
1232 get_inotify_watch(&parent->wdata);
1233 }
fe7752ba
DW		 1234 }
1235 }
f368c07d
AG		 1236
1237 list_del_rcu(&e->list);
1238 call_rcu(&e->rcu, audit_free_rule_rcu);
1239
1240 mutex_unlock(&audit_filter_mutex);
1241
1242 if (!list_empty(&inotify_list))
1243 audit_inotify_unregister(&inotify_list);
1244
1245out:
1246 if (tmp_watch)
1247 audit_put_watch(tmp_watch); /* match initial get */
1248
1249 return ret;
fe7752ba
DW		 1250}
1251
93315ed6
AG		 1252/* List rules using struct audit_rule. Exists for backward
1253 * compatibility with userspace. */
9044e6bc 1254static void audit_list(int pid, int seq, struct sk_buff_head *q)
fe7752ba 1255{
9044e6bc 1256 struct sk_buff *skb;
fe7752ba
DW		 1257 struct audit_entry *entry;
1258 int i;
1259
f368c07d
AG		 1260 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1261 * iterator to sync with list writers. */
fe7752ba 1262 for (i=0; i<AUDIT_NR_FILTERS; i++) {
93315ed6
AG		 1263 list_for_each_entry(entry, &audit_filter_list[i], list) {
1264 struct audit_rule *rule;
1265
1266 rule = audit_krule_to_rule(&entry->rule);
1267 if (unlikely(!rule))
1268 break;
9044e6bc 1269 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
93315ed6 1270 rule, sizeof(*rule));
9044e6bc
AV		 1271 if (skb)
1272 skb_queue_tail(q, skb);
93315ed6
AG		 1273 kfree(rule);
1274 }
fe7752ba 1275 }
f368c07d
AG		 1276 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1277 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1278 struct audit_rule *rule;
1279
1280 rule = audit_krule_to_rule(&entry->rule);
1281 if (unlikely(!rule))
1282 break;
1283 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1284 rule, sizeof(*rule));
1285 if (skb)
1286 skb_queue_tail(q, skb);
1287 kfree(rule);
1288 }
1289 }
9044e6bc
AV		 1290 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1291 if (skb)
1292 skb_queue_tail(q, skb);
fe7752ba
DW		 1293}
1294
93315ed6 1295/* List rules using struct audit_rule_data. */
9044e6bc 1296static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
93315ed6 1297{
9044e6bc 1298 struct sk_buff *skb;
93315ed6
AG		 1299 struct audit_entry *e;
1300 int i;
1301
f368c07d
AG		 1302 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1303 * iterator to sync with list writers. */
93315ed6
AG		 1304 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1305 list_for_each_entry(e, &audit_filter_list[i], list) {
1306 struct audit_rule_data *data;
1307
1308 data = audit_krule_to_data(&e->rule);
1309 if (unlikely(!data))
1310 break;
9044e6bc 1311 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
f368c07d
AG		 1312 data, sizeof(*data) + data->buflen);
1313 if (skb)
1314 skb_queue_tail(q, skb);
1315 kfree(data);
1316 }
1317 }
1318 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1319 list_for_each_entry(e, &audit_inode_hash[i], list) {
1320 struct audit_rule_data *data;
1321
1322 data = audit_krule_to_data(&e->rule);
1323 if (unlikely(!data))
1324 break;
1325 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1326 data, sizeof(*data) + data->buflen);
9044e6bc
AV		 1327 if (skb)
1328 skb_queue_tail(q, skb);
93315ed6
AG		 1329 kfree(data);
1330 }
1331 }
9044e6bc
AV		 1332 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1333 if (skb)
1334 skb_queue_tail(q, skb);
93315ed6
AG		 1335}
1336
5adc8a6a
AG		 1337/* Log rule additions and removals */
1338static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1339 struct audit_krule *rule, int res)
1340{
1341 struct audit_buffer *ab;
1342
1343 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1344 if (!ab)
1345 return;
1346 audit_log_format(ab, "auid=%u", loginuid);
1347 if (sid) {
1348 char *ctx = NULL;
1349 u32 len;
1350 if (selinux_ctxid_to_string(sid, &ctx, &len))
1351 audit_log_format(ab, " ssid=%u", sid);
1352 else
1353 audit_log_format(ab, " subj=%s", ctx);
1354 kfree(ctx);
1355 }
1356 audit_log_format(ab, " %s rule key=", action);
1357 if (rule->filterkey)
1358 audit_log_untrustedstring(ab, rule->filterkey);
1359 else
1360 audit_log_format(ab, "(null)");
1361 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1362 audit_log_end(ab);
1363}
1364
fe7752ba
DW		 1365/**
1366 * audit_receive_filter - apply all rules to the specified message type
1367 * @type: audit message type
1368 * @pid: target pid for netlink audit messages
1369 * @uid: target uid for netlink audit messages
1370 * @seq: netlink audit message sequence (serial) number
1371 * @data: payload data
93315ed6 1372 * @datasz: size of payload data
fe7752ba 1373 * @loginuid: loginuid of sender
ce29b682 1374 * @sid: SE Linux Security ID of sender
fe7752ba
DW		 1375 */
1376int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
ce29b682 1377 size_t datasz, uid_t loginuid, u32 sid)
fe7752ba
DW		 1378{
1379 struct task_struct *tsk;
9044e6bc 1380 struct audit_netlink_list *dest;
93315ed6
AG		 1381 int err = 0;
1382 struct audit_entry *entry;
fe7752ba
DW		 1383
1384 switch (type) {
1385 case AUDIT_LIST:
93315ed6 1386 case AUDIT_LIST_RULES:
fe7752ba
DW		 1387 /* We can't just spew out the rules here because we might fill
1388 * the available socket buffer space and deadlock waiting for
1389 * auditctl to read from it... which isn't ever going to
1390 * happen if we're actually running in the context of auditctl
1391 * trying to _send_ the stuff */
1392
9044e6bc 1393 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
fe7752ba
DW		 1394 if (!dest)
1395 return -ENOMEM;
9044e6bc
AV		 1396 dest->pid = pid;
1397 skb_queue_head_init(&dest->q);
fe7752ba 1398
f368c07d 1399 mutex_lock(&audit_filter_mutex);
93315ed6 1400 if (type == AUDIT_LIST)
9044e6bc 1401 audit_list(pid, seq, &dest->q);
93315ed6 1402 else
9044e6bc 1403 audit_list_rules(pid, seq, &dest->q);
f368c07d 1404 mutex_unlock(&audit_filter_mutex);
9044e6bc
AV		 1405
1406 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
fe7752ba 1407 if (IS_ERR(tsk)) {
9044e6bc 1408 skb_queue_purge(&dest->q);
fe7752ba
DW		 1409 kfree(dest);
1410 err = PTR_ERR(tsk);
1411 }
1412 break;
1413 case AUDIT_ADD:
93315ed6
AG		 1414 case AUDIT_ADD_RULE:
1415 if (type == AUDIT_ADD)
1416 entry = audit_rule_to_entry(data);
1417 else
1418 entry = audit_data_to_entry(data, datasz);
1419 if (IS_ERR(entry))
1420 return PTR_ERR(entry);
1421
1422 err = audit_add_rule(entry,
1423 &audit_filter_list[entry->rule.listnr]);
5adc8a6a 1424 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
5d330108
SG		 1425
1426 if (err)
93315ed6 1427 audit_free_rule(entry);
fe7752ba
DW		 1428 break;
1429 case AUDIT_DEL:
93315ed6
AG		 1430 case AUDIT_DEL_RULE:
1431 if (type == AUDIT_DEL)
1432 entry = audit_rule_to_entry(data);
1433 else
1434 entry = audit_data_to_entry(data, datasz);
1435 if (IS_ERR(entry))
1436 return PTR_ERR(entry);
1437
1438 err = audit_del_rule(entry,
1439 &audit_filter_list[entry->rule.listnr]);
5adc8a6a
AG		 1440 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1441 !err);
5d330108 1442
93315ed6 1443 audit_free_rule(entry);
fe7752ba
DW		 1444 break;
1445 default:
1446 return -EINVAL;
1447 }
1448
1449 return err;
1450}
1451
1452int audit_comparator(const u32 left, const u32 op, const u32 right)
1453{
1454 switch (op) {
1455 case AUDIT_EQUAL:
1456 return (left == right);
1457 case AUDIT_NOT_EQUAL:
1458 return (left != right);
1459 case AUDIT_LESS_THAN:
1460 return (left < right);
1461 case AUDIT_LESS_THAN_OR_EQUAL:
1462 return (left <= right);
1463 case AUDIT_GREATER_THAN:
1464 return (left > right);
1465 case AUDIT_GREATER_THAN_OR_EQUAL:
1466 return (left >= right);
fe7752ba 1467 }
d9d9ec6e
DK		 1468 BUG();
1469 return 0;
fe7752ba
DW		 1470}
1471
f368c07d
AG		 1472/* Compare given dentry name with last component in given path,
1473 * return of 0 indicates a match. */
9c937dcc
AG		 1474int audit_compare_dname_path(const char *dname, const char *path,
1475 int *dirlen)
f368c07d
AG		 1476{
1477 int dlen, plen;
1478 const char *p;
1479
1480 if (!dname || !path)
1481 return 1;
1482
1483 dlen = strlen(dname);
1484 plen = strlen(path);
1485 if (plen < dlen)
1486 return 1;
1487
1488 /* disregard trailing slashes */
1489 p = path + plen - 1;
1490 while ((*p == '/') && (p > path))
1491 p--;
1492
1493 /* find last path component */
1494 p = p - dlen + 1;
1495 if (p < path)
1496 return 1;
1497 else if (p > path) {
1498 if (*--p != '/')
1499 return 1;
1500 else
1501 p++;
1502 }
fe7752ba 1503
9c937dcc
AG		 1504 /* return length of path's directory component */
1505 if (dirlen)
1506 *dirlen = p - path;
f368c07d
AG		 1507 return strncmp(p, dname, dlen);
1508}
fe7752ba
DW		 1509
1510static int audit_filter_user_rules(struct netlink_skb_parms *cb,
93315ed6 1511 struct audit_krule *rule,
fe7752ba
DW		 1512 enum audit_state *state)
1513{
1514 int i;
1515
1516 for (i = 0; i < rule->field_count; i++) {
93315ed6 1517 struct audit_field *f = &rule->fields[i];
fe7752ba
DW		 1518 int result = 0;
1519
93315ed6 1520 switch (f->type) {
fe7752ba 1521 case AUDIT_PID:
93315ed6 1522 result = audit_comparator(cb->creds.pid, f->op, f->val);
fe7752ba
DW		 1523 break;
1524 case AUDIT_UID:
93315ed6 1525 result = audit_comparator(cb->creds.uid, f->op, f->val);
fe7752ba
DW		 1526 break;
1527 case AUDIT_GID:
93315ed6 1528 result = audit_comparator(cb->creds.gid, f->op, f->val);
fe7752ba
DW		 1529 break;
1530 case AUDIT_LOGINUID:
93315ed6 1531 result = audit_comparator(cb->loginuid, f->op, f->val);
fe7752ba
DW		 1532 break;
1533 }
1534
1535 if (!result)
1536 return 0;
1537 }
1538 switch (rule->action) {
1539 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
fe7752ba
DW		 1540 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1541 }
1542 return 1;
1543}
1544
1545int audit_filter_user(struct netlink_skb_parms *cb, int type)
1546{
1547 struct audit_entry *e;
1548 enum audit_state state;
1549 int ret = 1;
1550
1551 rcu_read_lock();
1552 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1553 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1554 if (state == AUDIT_DISABLED)
1555 ret = 0;
1556 break;
1557 }
1558 }
1559 rcu_read_unlock();
1560
1561 return ret; /* Audit by default */
1562}
1563
1564int audit_filter_type(int type)
1565{
1566 struct audit_entry *e;
1567 int result = 0;
1568
1569 rcu_read_lock();
1570 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1571 goto unlock_and_return;
1572
1573 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1574 list) {
fe7752ba 1575 int i;
93315ed6
AG		 1576 for (i = 0; i < e->rule.field_count; i++) {
1577 struct audit_field *f = &e->rule.fields[i];
1578 if (f->type == AUDIT_MSGTYPE) {
1579 result = audit_comparator(type, f->op, f->val);
fe7752ba
DW		 1580 if (!result)
1581 break;
1582 }
1583 }
1584 if (result)
1585 goto unlock_and_return;
1586 }
1587unlock_and_return:
1588 rcu_read_unlock();
1589 return result;
1590}
3dc7e315
DG		 1591
1592/* Check to see if the rule contains any selinux fields. Returns 1 if there
1593 are selinux fields specified in the rule, 0 otherwise. */
1594static inline int audit_rule_has_selinux(struct audit_krule *rule)
1595{
1596 int i;
1597
1598 for (i = 0; i < rule->field_count; i++) {
1599 struct audit_field *f = &rule->fields[i];
1600 switch (f->type) {
3a6b9f85
DG		 1601 case AUDIT_SUBJ_USER:
1602 case AUDIT_SUBJ_ROLE:
1603 case AUDIT_SUBJ_TYPE:
1604 case AUDIT_SUBJ_SEN:
1605 case AUDIT_SUBJ_CLR:
6e5a2d1d
DG		 1606 case AUDIT_OBJ_USER:
1607 case AUDIT_OBJ_ROLE:
1608 case AUDIT_OBJ_TYPE:
1609 case AUDIT_OBJ_LEV_LOW:
1610 case AUDIT_OBJ_LEV_HIGH:
3dc7e315
DG		 1611 return 1;
1612 }
1613 }
1614
1615 return 0;
1616}
1617
1618/* This function will re-initialize the se_rule field of all applicable rules.
1619 * It will traverse the filter lists serarching for rules that contain selinux
1620 * specific filter fields. When such a rule is found, it is copied, the
1621 * selinux field is re-initialized, and the old rule is replaced with the
1622 * updated rule. */
1623int selinux_audit_rule_update(void)
1624{
1625 struct audit_entry *entry, *n, *nentry;
f368c07d 1626 struct audit_watch *watch;
3dc7e315
DG		 1627 int i, err = 0;
1628
f368c07d
AG		 1629 /* audit_filter_mutex synchronizes the writers */
1630 mutex_lock(&audit_filter_mutex);
3dc7e315
DG		 1631
1632 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1633 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1634 if (!audit_rule_has_selinux(&entry->rule))
1635 continue;
1636
f368c07d
AG		 1637 watch = entry->rule.watch;
1638 nentry = audit_dupe_rule(&entry->rule, watch);
3dc7e315
DG		 1639 if (unlikely(IS_ERR(nentry))) {
1640 /* save the first error encountered for the
1641 * return value */
1642 if (!err)
1643 err = PTR_ERR(nentry);
1644 audit_panic("error updating selinux filters");
f368c07d
AG		 1645 if (watch)
1646 list_del(&entry->rule.rlist);
3dc7e315
DG		 1647 list_del_rcu(&entry->list);
1648 } else {
f368c07d
AG		 1649 if (watch) {
1650 list_add(&nentry->rule.rlist,
1651 &watch->rules);
1652 list_del(&entry->rule.rlist);
1653 }
3dc7e315
DG		 1654 list_replace_rcu(&entry->list, &nentry->list);
1655 }
1656 call_rcu(&entry->rcu, audit_free_rule_rcu);
1657 }
1658 }
1659
f368c07d 1660 mutex_unlock(&audit_filter_mutex);
3dc7e315
DG		 1661
1662 return err;
1663}
f368c07d
AG		 1664
1665/* Update watch data in audit rules based on inotify events. */
1666void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1667 u32 cookie, const char *dname, struct inode *inode)
1668{
1669 struct audit_parent *parent;
1670
1671 parent = container_of(i_watch, struct audit_parent, wdata);
1672
1673 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1674 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1675 inode->i_ino, 0);
1676 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1677 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1678 /* inotify automatically removes the watch and sends IN_IGNORED */
1679 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1680 audit_remove_parent_watches(parent);
1681 /* inotify does not remove the watch, so remove it manually */
1682 else if(mask & IN_MOVE_SELF) {
1683 audit_remove_parent_watches(parent);
1684 inotify_remove_watch_locked(audit_ih, i_watch);
1685 } else if (mask & IN_IGNORED)
1686 put_inotify_watch(i_watch);
1687}
Linux 6.x block layer and io_uring tree(s)