clockevents: tTack broadcast device mode change in tick_broadcast_switch_to_oneshot()
[linux-2.6.git] / kernel / auditfilter.c
1 /* auditfilter.c -- filtering of audit events
2  *
3  * Copyright 2003-2004 Red Hat, Inc.
4  * Copyright 2005 Hewlett-Packard Development Company, L.P.
5  * Copyright 2005 IBM Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20  */
21
22 #include <linux/kernel.h>
23 #include <linux/audit.h>
24 #include <linux/kthread.h>
25 #include <linux/mutex.h>
26 #include <linux/fs.h>
27 #include <linux/namei.h>
28 #include <linux/netlink.h>
29 #include <linux/sched.h>
30 #include <linux/slab.h>
31 #include <linux/security.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  *              LSM 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 /* Audit filter lists, defined in <linux/audit.h> */
48 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
49         LIST_HEAD_INIT(audit_filter_list[0]),
50         LIST_HEAD_INIT(audit_filter_list[1]),
51         LIST_HEAD_INIT(audit_filter_list[2]),
52         LIST_HEAD_INIT(audit_filter_list[3]),
53         LIST_HEAD_INIT(audit_filter_list[4]),
54         LIST_HEAD_INIT(audit_filter_list[5]),
55 #if AUDIT_NR_FILTERS != 6
56 #error Fix audit_filter_list initialiser
57 #endif
58 };
59 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
60         LIST_HEAD_INIT(audit_rules_list[0]),
61         LIST_HEAD_INIT(audit_rules_list[1]),
62         LIST_HEAD_INIT(audit_rules_list[2]),
63         LIST_HEAD_INIT(audit_rules_list[3]),
64         LIST_HEAD_INIT(audit_rules_list[4]),
65         LIST_HEAD_INIT(audit_rules_list[5]),
66 };
67
68 DEFINE_MUTEX(audit_filter_mutex);
69
70 static inline void audit_free_rule(struct audit_entry *e)
71 {
72         int i;
73         struct audit_krule *erule = &e->rule;
74
75         /* some rules don't have associated watches */
76         if (erule->watch)
77                 audit_put_watch(erule->watch);
78         if (erule->fields)
79                 for (i = 0; i < erule->field_count; i++) {
80                         struct audit_field *f = &erule->fields[i];
81                         kfree(f->lsm_str);
82                         security_audit_rule_free(f->lsm_rule);
83                 }
84         kfree(erule->fields);
85         kfree(erule->filterkey);
86         kfree(e);
87 }
88
89 void audit_free_rule_rcu(struct rcu_head *head)
90 {
91         struct audit_entry *e = container_of(head, struct audit_entry, rcu);
92         audit_free_rule(e);
93 }
94
95 /* Initialize an audit filterlist entry. */
96 static inline struct audit_entry *audit_init_entry(u32 field_count)
97 {
98         struct audit_entry *entry;
99         struct audit_field *fields;
100
101         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
102         if (unlikely(!entry))
103                 return NULL;
104
105         fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
106         if (unlikely(!fields)) {
107                 kfree(entry);
108                 return NULL;
109         }
110         entry->rule.fields = fields;
111
112         return entry;
113 }
114
115 /* Unpack a filter field's string representation from user-space
116  * buffer. */
117 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
118 {
119         char *str;
120
121         if (!*bufp || (len == 0) || (len > *remain))
122                 return ERR_PTR(-EINVAL);
123
124         /* Of the currently implemented string fields, PATH_MAX
125          * defines the longest valid length.
126          */
127         if (len > PATH_MAX)
128                 return ERR_PTR(-ENAMETOOLONG);
129
130         str = kmalloc(len + 1, GFP_KERNEL);
131         if (unlikely(!str))
132                 return ERR_PTR(-ENOMEM);
133
134         memcpy(str, *bufp, len);
135         str[len] = 0;
136         *bufp += len;
137         *remain -= len;
138
139         return str;
140 }
141
142 /* Translate an inode field to kernel respresentation. */
143 static inline int audit_to_inode(struct audit_krule *krule,
144                                  struct audit_field *f)
145 {
146         if (krule->listnr != AUDIT_FILTER_EXIT ||
147             krule->watch || krule->inode_f || krule->tree ||
148             (f->op != Audit_equal && f->op != Audit_not_equal))
149                 return -EINVAL;
150
151         krule->inode_f = f;
152         return 0;
153 }
154
155 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
156
157 int __init audit_register_class(int class, unsigned *list)
158 {
159         __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
160         if (!p)
161                 return -ENOMEM;
162         while (*list != ~0U) {
163                 unsigned n = *list++;
164                 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
165                         kfree(p);
166                         return -EINVAL;
167                 }
168                 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
169         }
170         if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
171                 kfree(p);
172                 return -EINVAL;
173         }
174         classes[class] = p;
175         return 0;
176 }
177
178 int audit_match_class(int class, unsigned syscall)
179 {
180         if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
181                 return 0;
182         if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
183                 return 0;
184         return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
185 }
186
187 #ifdef CONFIG_AUDITSYSCALL
188 static inline int audit_match_class_bits(int class, u32 *mask)
189 {
190         int i;
191
192         if (classes[class]) {
193                 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
194                         if (mask[i] & classes[class][i])
195                                 return 0;
196         }
197         return 1;
198 }
199
200 static int audit_match_signal(struct audit_entry *entry)
201 {
202         struct audit_field *arch = entry->rule.arch_f;
203
204         if (!arch) {
205                 /* When arch is unspecified, we must check both masks on biarch
206                  * as syscall number alone is ambiguous. */
207                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
208                                                entry->rule.mask) &&
209                         audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
210                                                entry->rule.mask));
211         }
212
213         switch(audit_classify_arch(arch->val)) {
214         case 0: /* native */
215                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
216                                                entry->rule.mask));
217         case 1: /* 32bit on biarch */
218                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
219                                                entry->rule.mask));
220         default:
221                 return 1;
222         }
223 }
224 #endif
225
226 /* Common user-space to kernel rule translation. */
227 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
228 {
229         unsigned listnr;
230         struct audit_entry *entry;
231         int i, err;
232
233         err = -EINVAL;
234         listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
235         switch(listnr) {
236         default:
237                 goto exit_err;
238 #ifdef CONFIG_AUDITSYSCALL
239         case AUDIT_FILTER_ENTRY:
240                 if (rule->action == AUDIT_ALWAYS)
241                         goto exit_err;
242         case AUDIT_FILTER_EXIT:
243         case AUDIT_FILTER_TASK:
244 #endif
245         case AUDIT_FILTER_USER:
246         case AUDIT_FILTER_TYPE:
247                 ;
248         }
249         if (unlikely(rule->action == AUDIT_POSSIBLE)) {
250                 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
251                 goto exit_err;
252         }
253         if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
254                 goto exit_err;
255         if (rule->field_count > AUDIT_MAX_FIELDS)
256                 goto exit_err;
257
258         err = -ENOMEM;
259         entry = audit_init_entry(rule->field_count);
260         if (!entry)
261                 goto exit_err;
262
263         entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
264         entry->rule.listnr = listnr;
265         entry->rule.action = rule->action;
266         entry->rule.field_count = rule->field_count;
267
268         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
269                 entry->rule.mask[i] = rule->mask[i];
270
271         for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
272                 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
273                 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
274                 __u32 *class;
275
276                 if (!(*p & AUDIT_BIT(bit)))
277                         continue;
278                 *p &= ~AUDIT_BIT(bit);
279                 class = classes[i];
280                 if (class) {
281                         int j;
282                         for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
283                                 entry->rule.mask[j] |= class[j];
284                 }
285         }
286
287         return entry;
288
289 exit_err:
290         return ERR_PTR(err);
291 }
292
293 static u32 audit_ops[] =
294 {
295         [Audit_equal] = AUDIT_EQUAL,
296         [Audit_not_equal] = AUDIT_NOT_EQUAL,
297         [Audit_bitmask] = AUDIT_BIT_MASK,
298         [Audit_bittest] = AUDIT_BIT_TEST,
299         [Audit_lt] = AUDIT_LESS_THAN,
300         [Audit_gt] = AUDIT_GREATER_THAN,
301         [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
302         [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
303 };
304
305 static u32 audit_to_op(u32 op)
306 {
307         u32 n;
308         for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
309                 ;
310         return n;
311 }
312
313
314 /* Translate struct audit_rule to kernel's rule respresentation.
315  * Exists for backward compatibility with userspace. */
316 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
317 {
318         struct audit_entry *entry;
319         int err = 0;
320         int i;
321
322         entry = audit_to_entry_common(rule);
323         if (IS_ERR(entry))
324                 goto exit_nofree;
325
326         for (i = 0; i < rule->field_count; i++) {
327                 struct audit_field *f = &entry->rule.fields[i];
328                 u32 n;
329
330                 n = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
331
332                 /* Support for legacy operators where
333                  * AUDIT_NEGATE bit signifies != and otherwise assumes == */
334                 if (n & AUDIT_NEGATE)
335                         f->op = Audit_not_equal;
336                 else if (!n)
337                         f->op = Audit_equal;
338                 else
339                         f->op = audit_to_op(n);
340
341                 entry->rule.vers_ops = (n & AUDIT_OPERATORS) ? 2 : 1;
342
343                 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
344                 f->val = rule->values[i];
345
346                 err = -EINVAL;
347                 if (f->op == Audit_bad)
348                         goto exit_free;
349
350                 switch(f->type) {
351                 default:
352                         goto exit_free;
353                 case AUDIT_PID:
354                 case AUDIT_UID:
355                 case AUDIT_EUID:
356                 case AUDIT_SUID:
357                 case AUDIT_FSUID:
358                 case AUDIT_GID:
359                 case AUDIT_EGID:
360                 case AUDIT_SGID:
361                 case AUDIT_FSGID:
362                 case AUDIT_LOGINUID:
363                 case AUDIT_PERS:
364                 case AUDIT_MSGTYPE:
365                 case AUDIT_PPID:
366                 case AUDIT_DEVMAJOR:
367                 case AUDIT_DEVMINOR:
368                 case AUDIT_EXIT:
369                 case AUDIT_SUCCESS:
370                         /* bit ops are only useful on syscall args */
371                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
372                                 goto exit_free;
373                         break;
374                 case AUDIT_ARG0:
375                 case AUDIT_ARG1:
376                 case AUDIT_ARG2:
377                 case AUDIT_ARG3:
378                         break;
379                 /* arch is only allowed to be = or != */
380                 case AUDIT_ARCH:
381                         if (f->op != Audit_not_equal && f->op != Audit_equal)
382                                 goto exit_free;
383                         entry->rule.arch_f = f;
384                         break;
385                 case AUDIT_PERM:
386                         if (f->val & ~15)
387                                 goto exit_free;
388                         break;
389                 case AUDIT_FILETYPE:
390                         if (f->val & ~S_IFMT)
391                                 goto exit_free;
392                         break;
393                 case AUDIT_INODE:
394                         err = audit_to_inode(&entry->rule, f);
395                         if (err)
396                                 goto exit_free;
397                         break;
398                 }
399         }
400
401         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
402                 entry->rule.inode_f = NULL;
403
404 exit_nofree:
405         return entry;
406
407 exit_free:
408         audit_free_rule(entry);
409         return ERR_PTR(err);
410 }
411
412 /* Translate struct audit_rule_data to kernel's rule respresentation. */
413 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
414                                                size_t datasz)
415 {
416         int err = 0;
417         struct audit_entry *entry;
418         void *bufp;
419         size_t remain = datasz - sizeof(struct audit_rule_data);
420         int i;
421         char *str;
422
423         entry = audit_to_entry_common((struct audit_rule *)data);
424         if (IS_ERR(entry))
425                 goto exit_nofree;
426
427         bufp = data->buf;
428         entry->rule.vers_ops = 2;
429         for (i = 0; i < data->field_count; i++) {
430                 struct audit_field *f = &entry->rule.fields[i];
431
432                 err = -EINVAL;
433
434                 f->op = audit_to_op(data->fieldflags[i]);
435                 if (f->op == Audit_bad)
436                         goto exit_free;
437
438                 f->type = data->fields[i];
439                 f->val = data->values[i];
440                 f->lsm_str = NULL;
441                 f->lsm_rule = NULL;
442                 switch(f->type) {
443                 case AUDIT_PID:
444                 case AUDIT_UID:
445                 case AUDIT_EUID:
446                 case AUDIT_SUID:
447                 case AUDIT_FSUID:
448                 case AUDIT_GID:
449                 case AUDIT_EGID:
450                 case AUDIT_SGID:
451                 case AUDIT_FSGID:
452                 case AUDIT_LOGINUID:
453                 case AUDIT_PERS:
454                 case AUDIT_MSGTYPE:
455                 case AUDIT_PPID:
456                 case AUDIT_DEVMAJOR:
457                 case AUDIT_DEVMINOR:
458                 case AUDIT_EXIT:
459                 case AUDIT_SUCCESS:
460                 case AUDIT_ARG0:
461                 case AUDIT_ARG1:
462                 case AUDIT_ARG2:
463                 case AUDIT_ARG3:
464                 case AUDIT_OBJ_UID:
465                 case AUDIT_OBJ_GID:
466                         break;
467                 case AUDIT_ARCH:
468                         entry->rule.arch_f = f;
469                         break;
470                 case AUDIT_SUBJ_USER:
471                 case AUDIT_SUBJ_ROLE:
472                 case AUDIT_SUBJ_TYPE:
473                 case AUDIT_SUBJ_SEN:
474                 case AUDIT_SUBJ_CLR:
475                 case AUDIT_OBJ_USER:
476                 case AUDIT_OBJ_ROLE:
477                 case AUDIT_OBJ_TYPE:
478                 case AUDIT_OBJ_LEV_LOW:
479                 case AUDIT_OBJ_LEV_HIGH:
480                         str = audit_unpack_string(&bufp, &remain, f->val);
481                         if (IS_ERR(str))
482                                 goto exit_free;
483                         entry->rule.buflen += f->val;
484
485                         err = security_audit_rule_init(f->type, f->op, str,
486                                                        (void **)&f->lsm_rule);
487                         /* Keep currently invalid fields around in case they
488                          * become valid after a policy reload. */
489                         if (err == -EINVAL) {
490                                 printk(KERN_WARNING "audit rule for LSM "
491                                        "\'%s\' is invalid\n",  str);
492                                 err = 0;
493                         }
494                         if (err) {
495                                 kfree(str);
496                                 goto exit_free;
497                         } else
498                                 f->lsm_str = str;
499                         break;
500                 case AUDIT_WATCH:
501                         str = audit_unpack_string(&bufp, &remain, f->val);
502                         if (IS_ERR(str))
503                                 goto exit_free;
504                         entry->rule.buflen += f->val;
505
506                         err = audit_to_watch(&entry->rule, str, f->val, f->op);
507                         if (err) {
508                                 kfree(str);
509                                 goto exit_free;
510                         }
511                         break;
512                 case AUDIT_DIR:
513                         str = audit_unpack_string(&bufp, &remain, f->val);
514                         if (IS_ERR(str))
515                                 goto exit_free;
516                         entry->rule.buflen += f->val;
517
518                         err = audit_make_tree(&entry->rule, str, f->op);
519                         kfree(str);
520                         if (err)
521                                 goto exit_free;
522                         break;
523                 case AUDIT_INODE:
524                         err = audit_to_inode(&entry->rule, f);
525                         if (err)
526                                 goto exit_free;
527                         break;
528                 case AUDIT_FILTERKEY:
529                         if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
530                                 goto exit_free;
531                         str = audit_unpack_string(&bufp, &remain, f->val);
532                         if (IS_ERR(str))
533                                 goto exit_free;
534                         entry->rule.buflen += f->val;
535                         entry->rule.filterkey = str;
536                         break;
537                 case AUDIT_PERM:
538                         if (f->val & ~15)
539                                 goto exit_free;
540                         break;
541                 case AUDIT_FILETYPE:
542                         if (f->val & ~S_IFMT)
543                                 goto exit_free;
544                         break;
545                 case AUDIT_FIELD_COMPARE:
546                         if (f->val > AUDIT_MAX_FIELD_COMPARE)
547                                 goto exit_free;
548                         break;
549                 default:
550                         goto exit_free;
551                 }
552         }
553
554         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
555                 entry->rule.inode_f = NULL;
556
557 exit_nofree:
558         return entry;
559
560 exit_free:
561         audit_free_rule(entry);
562         return ERR_PTR(err);
563 }
564
565 /* Pack a filter field's string representation into data block. */
566 static inline size_t audit_pack_string(void **bufp, const char *str)
567 {
568         size_t len = strlen(str);
569
570         memcpy(*bufp, str, len);
571         *bufp += len;
572
573         return len;
574 }
575
576 /* Translate kernel rule respresentation to struct audit_rule.
577  * Exists for backward compatibility with userspace. */
578 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
579 {
580         struct audit_rule *rule;
581         int i;
582
583         rule = kzalloc(sizeof(*rule), GFP_KERNEL);
584         if (unlikely(!rule))
585                 return NULL;
586
587         rule->flags = krule->flags | krule->listnr;
588         rule->action = krule->action;
589         rule->field_count = krule->field_count;
590         for (i = 0; i < rule->field_count; i++) {
591                 rule->values[i] = krule->fields[i].val;
592                 rule->fields[i] = krule->fields[i].type;
593
594                 if (krule->vers_ops == 1) {
595                         if (krule->fields[i].op == Audit_not_equal)
596                                 rule->fields[i] |= AUDIT_NEGATE;
597                 } else {
598                         rule->fields[i] |= audit_ops[krule->fields[i].op];
599                 }
600         }
601         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
602
603         return rule;
604 }
605
606 /* Translate kernel rule respresentation to struct audit_rule_data. */
607 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
608 {
609         struct audit_rule_data *data;
610         void *bufp;
611         int i;
612
613         data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
614         if (unlikely(!data))
615                 return NULL;
616         memset(data, 0, sizeof(*data));
617
618         data->flags = krule->flags | krule->listnr;
619         data->action = krule->action;
620         data->field_count = krule->field_count;
621         bufp = data->buf;
622         for (i = 0; i < data->field_count; i++) {
623                 struct audit_field *f = &krule->fields[i];
624
625                 data->fields[i] = f->type;
626                 data->fieldflags[i] = audit_ops[f->op];
627                 switch(f->type) {
628                 case AUDIT_SUBJ_USER:
629                 case AUDIT_SUBJ_ROLE:
630                 case AUDIT_SUBJ_TYPE:
631                 case AUDIT_SUBJ_SEN:
632                 case AUDIT_SUBJ_CLR:
633                 case AUDIT_OBJ_USER:
634                 case AUDIT_OBJ_ROLE:
635                 case AUDIT_OBJ_TYPE:
636                 case AUDIT_OBJ_LEV_LOW:
637                 case AUDIT_OBJ_LEV_HIGH:
638                         data->buflen += data->values[i] =
639                                 audit_pack_string(&bufp, f->lsm_str);
640                         break;
641                 case AUDIT_WATCH:
642                         data->buflen += data->values[i] =
643                                 audit_pack_string(&bufp,
644                                                   audit_watch_path(krule->watch));
645                         break;
646                 case AUDIT_DIR:
647                         data->buflen += data->values[i] =
648                                 audit_pack_string(&bufp,
649                                                   audit_tree_path(krule->tree));
650                         break;
651                 case AUDIT_FILTERKEY:
652                         data->buflen += data->values[i] =
653                                 audit_pack_string(&bufp, krule->filterkey);
654                         break;
655                 default:
656                         data->values[i] = f->val;
657                 }
658         }
659         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
660
661         return data;
662 }
663
664 /* Compare two rules in kernel format.  Considered success if rules
665  * don't match. */
666 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
667 {
668         int i;
669
670         if (a->flags != b->flags ||
671             a->listnr != b->listnr ||
672             a->action != b->action ||
673             a->field_count != b->field_count)
674                 return 1;
675
676         for (i = 0; i < a->field_count; i++) {
677                 if (a->fields[i].type != b->fields[i].type ||
678                     a->fields[i].op != b->fields[i].op)
679                         return 1;
680
681                 switch(a->fields[i].type) {
682                 case AUDIT_SUBJ_USER:
683                 case AUDIT_SUBJ_ROLE:
684                 case AUDIT_SUBJ_TYPE:
685                 case AUDIT_SUBJ_SEN:
686                 case AUDIT_SUBJ_CLR:
687                 case AUDIT_OBJ_USER:
688                 case AUDIT_OBJ_ROLE:
689                 case AUDIT_OBJ_TYPE:
690                 case AUDIT_OBJ_LEV_LOW:
691                 case AUDIT_OBJ_LEV_HIGH:
692                         if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
693                                 return 1;
694                         break;
695                 case AUDIT_WATCH:
696                         if (strcmp(audit_watch_path(a->watch),
697                                    audit_watch_path(b->watch)))
698                                 return 1;
699                         break;
700                 case AUDIT_DIR:
701                         if (strcmp(audit_tree_path(a->tree),
702                                    audit_tree_path(b->tree)))
703                                 return 1;
704                         break;
705                 case AUDIT_FILTERKEY:
706                         /* both filterkeys exist based on above type compare */
707                         if (strcmp(a->filterkey, b->filterkey))
708                                 return 1;
709                         break;
710                 default:
711                         if (a->fields[i].val != b->fields[i].val)
712                                 return 1;
713                 }
714         }
715
716         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
717                 if (a->mask[i] != b->mask[i])
718                         return 1;
719
720         return 0;
721 }
722
723 /* Duplicate LSM field information.  The lsm_rule is opaque, so must be
724  * re-initialized. */
725 static inline int audit_dupe_lsm_field(struct audit_field *df,
726                                            struct audit_field *sf)
727 {
728         int ret = 0;
729         char *lsm_str;
730
731         /* our own copy of lsm_str */
732         lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
733         if (unlikely(!lsm_str))
734                 return -ENOMEM;
735         df->lsm_str = lsm_str;
736
737         /* our own (refreshed) copy of lsm_rule */
738         ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
739                                        (void **)&df->lsm_rule);
740         /* Keep currently invalid fields around in case they
741          * become valid after a policy reload. */
742         if (ret == -EINVAL) {
743                 printk(KERN_WARNING "audit rule for LSM \'%s\' is "
744                        "invalid\n", df->lsm_str);
745                 ret = 0;
746         }
747
748         return ret;
749 }
750
751 /* Duplicate an audit rule.  This will be a deep copy with the exception
752  * of the watch - that pointer is carried over.  The LSM specific fields
753  * will be updated in the copy.  The point is to be able to replace the old
754  * rule with the new rule in the filterlist, then free the old rule.
755  * The rlist element is undefined; list manipulations are handled apart from
756  * the initial copy. */
757 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
758 {
759         u32 fcount = old->field_count;
760         struct audit_entry *entry;
761         struct audit_krule *new;
762         char *fk;
763         int i, err = 0;
764
765         entry = audit_init_entry(fcount);
766         if (unlikely(!entry))
767                 return ERR_PTR(-ENOMEM);
768
769         new = &entry->rule;
770         new->vers_ops = old->vers_ops;
771         new->flags = old->flags;
772         new->listnr = old->listnr;
773         new->action = old->action;
774         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
775                 new->mask[i] = old->mask[i];
776         new->prio = old->prio;
777         new->buflen = old->buflen;
778         new->inode_f = old->inode_f;
779         new->field_count = old->field_count;
780
781         /*
782          * note that we are OK with not refcounting here; audit_match_tree()
783          * never dereferences tree and we can't get false positives there
784          * since we'd have to have rule gone from the list *and* removed
785          * before the chunks found by lookup had been allocated, i.e. before
786          * the beginning of list scan.
787          */
788         new->tree = old->tree;
789         memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
790
791         /* deep copy this information, updating the lsm_rule fields, because
792          * the originals will all be freed when the old rule is freed. */
793         for (i = 0; i < fcount; i++) {
794                 switch (new->fields[i].type) {
795                 case AUDIT_SUBJ_USER:
796                 case AUDIT_SUBJ_ROLE:
797                 case AUDIT_SUBJ_TYPE:
798                 case AUDIT_SUBJ_SEN:
799                 case AUDIT_SUBJ_CLR:
800                 case AUDIT_OBJ_USER:
801                 case AUDIT_OBJ_ROLE:
802                 case AUDIT_OBJ_TYPE:
803                 case AUDIT_OBJ_LEV_LOW:
804                 case AUDIT_OBJ_LEV_HIGH:
805                         err = audit_dupe_lsm_field(&new->fields[i],
806                                                        &old->fields[i]);
807                         break;
808                 case AUDIT_FILTERKEY:
809                         fk = kstrdup(old->filterkey, GFP_KERNEL);
810                         if (unlikely(!fk))
811                                 err = -ENOMEM;
812                         else
813                                 new->filterkey = fk;
814                 }
815                 if (err) {
816                         audit_free_rule(entry);
817                         return ERR_PTR(err);
818                 }
819         }
820
821         if (old->watch) {
822                 audit_get_watch(old->watch);
823                 new->watch = old->watch;
824         }
825
826         return entry;
827 }
828
829 /* Find an existing audit rule.
830  * Caller must hold audit_filter_mutex to prevent stale rule data. */
831 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
832                                            struct list_head **p)
833 {
834         struct audit_entry *e, *found = NULL;
835         struct list_head *list;
836         int h;
837
838         if (entry->rule.inode_f) {
839                 h = audit_hash_ino(entry->rule.inode_f->val);
840                 *p = list = &audit_inode_hash[h];
841         } else if (entry->rule.watch) {
842                 /* we don't know the inode number, so must walk entire hash */
843                 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
844                         list = &audit_inode_hash[h];
845                         list_for_each_entry(e, list, list)
846                                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
847                                         found = e;
848                                         goto out;
849                                 }
850                 }
851                 goto out;
852         } else {
853                 *p = list = &audit_filter_list[entry->rule.listnr];
854         }
855
856         list_for_each_entry(e, list, list)
857                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
858                         found = e;
859                         goto out;
860                 }
861
862 out:
863         return found;
864 }
865
866 static u64 prio_low = ~0ULL/2;
867 static u64 prio_high = ~0ULL/2 - 1;
868
869 /* Add rule to given filterlist if not a duplicate. */
870 static inline int audit_add_rule(struct audit_entry *entry)
871 {
872         struct audit_entry *e;
873         struct audit_watch *watch = entry->rule.watch;
874         struct audit_tree *tree = entry->rule.tree;
875         struct list_head *list;
876         int err;
877 #ifdef CONFIG_AUDITSYSCALL
878         int dont_count = 0;
879
880         /* If either of these, don't count towards total */
881         if (entry->rule.listnr == AUDIT_FILTER_USER ||
882                 entry->rule.listnr == AUDIT_FILTER_TYPE)
883                 dont_count = 1;
884 #endif
885
886         mutex_lock(&audit_filter_mutex);
887         e = audit_find_rule(entry, &list);
888         if (e) {
889                 mutex_unlock(&audit_filter_mutex);
890                 err = -EEXIST;
891                 /* normally audit_add_tree_rule() will free it on failure */
892                 if (tree)
893                         audit_put_tree(tree);
894                 goto error;
895         }
896
897         if (watch) {
898                 /* audit_filter_mutex is dropped and re-taken during this call */
899                 err = audit_add_watch(&entry->rule, &list);
900                 if (err) {
901                         mutex_unlock(&audit_filter_mutex);
902                         goto error;
903                 }
904         }
905         if (tree) {
906                 err = audit_add_tree_rule(&entry->rule);
907                 if (err) {
908                         mutex_unlock(&audit_filter_mutex);
909                         goto error;
910                 }
911         }
912
913         entry->rule.prio = ~0ULL;
914         if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
915                 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
916                         entry->rule.prio = ++prio_high;
917                 else
918                         entry->rule.prio = --prio_low;
919         }
920
921         if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
922                 list_add(&entry->rule.list,
923                          &audit_rules_list[entry->rule.listnr]);
924                 list_add_rcu(&entry->list, list);
925                 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
926         } else {
927                 list_add_tail(&entry->rule.list,
928                               &audit_rules_list[entry->rule.listnr]);
929                 list_add_tail_rcu(&entry->list, list);
930         }
931 #ifdef CONFIG_AUDITSYSCALL
932         if (!dont_count)
933                 audit_n_rules++;
934
935         if (!audit_match_signal(entry))
936                 audit_signals++;
937 #endif
938         mutex_unlock(&audit_filter_mutex);
939
940         return 0;
941
942 error:
943         if (watch)
944                 audit_put_watch(watch); /* tmp watch, matches initial get */
945         return err;
946 }
947
948 /* Remove an existing rule from filterlist. */
949 static inline int audit_del_rule(struct audit_entry *entry)
950 {
951         struct audit_entry  *e;
952         struct audit_watch *watch = entry->rule.watch;
953         struct audit_tree *tree = entry->rule.tree;
954         struct list_head *list;
955         int ret = 0;
956 #ifdef CONFIG_AUDITSYSCALL
957         int dont_count = 0;
958
959         /* If either of these, don't count towards total */
960         if (entry->rule.listnr == AUDIT_FILTER_USER ||
961                 entry->rule.listnr == AUDIT_FILTER_TYPE)
962                 dont_count = 1;
963 #endif
964
965         mutex_lock(&audit_filter_mutex);
966         e = audit_find_rule(entry, &list);
967         if (!e) {
968                 mutex_unlock(&audit_filter_mutex);
969                 ret = -ENOENT;
970                 goto out;
971         }
972
973         if (e->rule.watch)
974                 audit_remove_watch_rule(&e->rule);
975
976         if (e->rule.tree)
977                 audit_remove_tree_rule(&e->rule);
978
979         list_del_rcu(&e->list);
980         list_del(&e->rule.list);
981         call_rcu(&e->rcu, audit_free_rule_rcu);
982
983 #ifdef CONFIG_AUDITSYSCALL
984         if (!dont_count)
985                 audit_n_rules--;
986
987         if (!audit_match_signal(entry))
988                 audit_signals--;
989 #endif
990         mutex_unlock(&audit_filter_mutex);
991
992 out:
993         if (watch)
994                 audit_put_watch(watch); /* match initial get */
995         if (tree)
996                 audit_put_tree(tree);   /* that's the temporary one */
997
998         return ret;
999 }
1000
1001 /* List rules using struct audit_rule.  Exists for backward
1002  * compatibility with userspace. */
1003 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1004 {
1005         struct sk_buff *skb;
1006         struct audit_krule *r;
1007         int i;
1008
1009         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1010          * iterator to sync with list writers. */
1011         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1012                 list_for_each_entry(r, &audit_rules_list[i], list) {
1013                         struct audit_rule *rule;
1014
1015                         rule = audit_krule_to_rule(r);
1016                         if (unlikely(!rule))
1017                                 break;
1018                         skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1019                                          rule, sizeof(*rule));
1020                         if (skb)
1021                                 skb_queue_tail(q, skb);
1022                         kfree(rule);
1023                 }
1024         }
1025         skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1026         if (skb)
1027                 skb_queue_tail(q, skb);
1028 }
1029
1030 /* List rules using struct audit_rule_data. */
1031 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1032 {
1033         struct sk_buff *skb;
1034         struct audit_krule *r;
1035         int i;
1036
1037         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1038          * iterator to sync with list writers. */
1039         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1040                 list_for_each_entry(r, &audit_rules_list[i], list) {
1041                         struct audit_rule_data *data;
1042
1043                         data = audit_krule_to_data(r);
1044                         if (unlikely(!data))
1045                                 break;
1046                         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1047                                          data, sizeof(*data) + data->buflen);
1048                         if (skb)
1049                                 skb_queue_tail(q, skb);
1050                         kfree(data);
1051                 }
1052         }
1053         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1054         if (skb)
1055                 skb_queue_tail(q, skb);
1056 }
1057
1058 /* Log rule additions and removals */
1059 static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid,
1060                                   char *action, struct audit_krule *rule,
1061                                   int res)
1062 {
1063         struct audit_buffer *ab;
1064
1065         if (!audit_enabled)
1066                 return;
1067
1068         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1069         if (!ab)
1070                 return;
1071         audit_log_format(ab, "auid=%u ses=%u", loginuid, sessionid);
1072         if (sid) {
1073                 char *ctx = NULL;
1074                 u32 len;
1075                 if (security_secid_to_secctx(sid, &ctx, &len))
1076                         audit_log_format(ab, " ssid=%u", sid);
1077                 else {
1078                         audit_log_format(ab, " subj=%s", ctx);
1079                         security_release_secctx(ctx, len);
1080                 }
1081         }
1082         audit_log_format(ab, " op=");
1083         audit_log_string(ab, action);
1084         audit_log_key(ab, rule->filterkey);
1085         audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1086         audit_log_end(ab);
1087 }
1088
1089 /**
1090  * audit_receive_filter - apply all rules to the specified message type
1091  * @type: audit message type
1092  * @pid: target pid for netlink audit messages
1093  * @uid: target uid for netlink audit messages
1094  * @seq: netlink audit message sequence (serial) number
1095  * @data: payload data
1096  * @datasz: size of payload data
1097  * @loginuid: loginuid of sender
1098  * @sessionid: sessionid for netlink audit message
1099  * @sid: SE Linux Security ID of sender
1100  */
1101 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1102                          size_t datasz, uid_t loginuid, u32 sessionid, u32 sid)
1103 {
1104         struct task_struct *tsk;
1105         struct audit_netlink_list *dest;
1106         int err = 0;
1107         struct audit_entry *entry;
1108
1109         switch (type) {
1110         case AUDIT_LIST:
1111         case AUDIT_LIST_RULES:
1112                 /* We can't just spew out the rules here because we might fill
1113                  * the available socket buffer space and deadlock waiting for
1114                  * auditctl to read from it... which isn't ever going to
1115                  * happen if we're actually running in the context of auditctl
1116                  * trying to _send_ the stuff */
1117
1118                 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1119                 if (!dest)
1120                         return -ENOMEM;
1121                 dest->pid = pid;
1122                 skb_queue_head_init(&dest->q);
1123
1124                 mutex_lock(&audit_filter_mutex);
1125                 if (type == AUDIT_LIST)
1126                         audit_list(pid, seq, &dest->q);
1127                 else
1128                         audit_list_rules(pid, seq, &dest->q);
1129                 mutex_unlock(&audit_filter_mutex);
1130
1131                 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1132                 if (IS_ERR(tsk)) {
1133                         skb_queue_purge(&dest->q);
1134                         kfree(dest);
1135                         err = PTR_ERR(tsk);
1136                 }
1137                 break;
1138         case AUDIT_ADD:
1139         case AUDIT_ADD_RULE:
1140                 if (type == AUDIT_ADD)
1141                         entry = audit_rule_to_entry(data);
1142                 else
1143                         entry = audit_data_to_entry(data, datasz);
1144                 if (IS_ERR(entry))
1145                         return PTR_ERR(entry);
1146
1147                 err = audit_add_rule(entry);
1148                 audit_log_rule_change(loginuid, sessionid, sid, "add rule",
1149                                       &entry->rule, !err);
1150
1151                 if (err)
1152                         audit_free_rule(entry);
1153                 break;
1154         case AUDIT_DEL:
1155         case AUDIT_DEL_RULE:
1156                 if (type == AUDIT_DEL)
1157                         entry = audit_rule_to_entry(data);
1158                 else
1159                         entry = audit_data_to_entry(data, datasz);
1160                 if (IS_ERR(entry))
1161                         return PTR_ERR(entry);
1162
1163                 err = audit_del_rule(entry);
1164                 audit_log_rule_change(loginuid, sessionid, sid, "remove rule",
1165                                       &entry->rule, !err);
1166
1167                 audit_free_rule(entry);
1168                 break;
1169         default:
1170                 return -EINVAL;
1171         }
1172
1173         return err;
1174 }
1175
1176 int audit_comparator(u32 left, u32 op, u32 right)
1177 {
1178         switch (op) {
1179         case Audit_equal:
1180                 return (left == right);
1181         case Audit_not_equal:
1182                 return (left != right);
1183         case Audit_lt:
1184                 return (left < right);
1185         case Audit_le:
1186                 return (left <= right);
1187         case Audit_gt:
1188                 return (left > right);
1189         case Audit_ge:
1190                 return (left >= right);
1191         case Audit_bitmask:
1192                 return (left & right);
1193         case Audit_bittest:
1194                 return ((left & right) == right);
1195         default:
1196                 BUG();
1197                 return 0;
1198         }
1199 }
1200
1201 /* Compare given dentry name with last component in given path,
1202  * return of 0 indicates a match. */
1203 int audit_compare_dname_path(const char *dname, const char *path,
1204                              int *dirlen)
1205 {
1206         int dlen, plen;
1207         const char *p;
1208
1209         if (!dname || !path)
1210                 return 1;
1211
1212         dlen = strlen(dname);
1213         plen = strlen(path);
1214         if (plen < dlen)
1215                 return 1;
1216
1217         /* disregard trailing slashes */
1218         p = path + plen - 1;
1219         while ((*p == '/') && (p > path))
1220                 p--;
1221
1222         /* find last path component */
1223         p = p - dlen + 1;
1224         if (p < path)
1225                 return 1;
1226         else if (p > path) {
1227                 if (*--p != '/')
1228                         return 1;
1229                 else
1230                         p++;
1231         }
1232
1233         /* return length of path's directory component */
1234         if (dirlen)
1235                 *dirlen = p - path;
1236         return strncmp(p, dname, dlen);
1237 }
1238
1239 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1240                                    struct audit_krule *rule,
1241                                    enum audit_state *state)
1242 {
1243         int i;
1244
1245         for (i = 0; i < rule->field_count; i++) {
1246                 struct audit_field *f = &rule->fields[i];
1247                 int result = 0;
1248                 u32 sid;
1249
1250                 switch (f->type) {
1251                 case AUDIT_PID:
1252                         result = audit_comparator(cb->creds.pid, f->op, f->val);
1253                         break;
1254                 case AUDIT_UID:
1255                         result = audit_comparator(cb->creds.uid, f->op, f->val);
1256                         break;
1257                 case AUDIT_GID:
1258                         result = audit_comparator(cb->creds.gid, f->op, f->val);
1259                         break;
1260                 case AUDIT_LOGINUID:
1261                         result = audit_comparator(audit_get_loginuid(current),
1262                                                   f->op, f->val);
1263                         break;
1264                 case AUDIT_SUBJ_USER:
1265                 case AUDIT_SUBJ_ROLE:
1266                 case AUDIT_SUBJ_TYPE:
1267                 case AUDIT_SUBJ_SEN:
1268                 case AUDIT_SUBJ_CLR:
1269                         if (f->lsm_rule) {
1270                                 security_task_getsecid(current, &sid);
1271                                 result = security_audit_rule_match(sid,
1272                                                                    f->type,
1273                                                                    f->op,
1274                                                                    f->lsm_rule,
1275                                                                    NULL);
1276                         }
1277                         break;
1278                 }
1279
1280                 if (!result)
1281                         return 0;
1282         }
1283         switch (rule->action) {
1284         case AUDIT_NEVER:    *state = AUDIT_DISABLED;       break;
1285         case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
1286         }
1287         return 1;
1288 }
1289
1290 int audit_filter_user(struct netlink_skb_parms *cb)
1291 {
1292         enum audit_state state = AUDIT_DISABLED;
1293         struct audit_entry *e;
1294         int ret = 1;
1295
1296         rcu_read_lock();
1297         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1298                 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1299                         if (state == AUDIT_DISABLED)
1300                                 ret = 0;
1301                         break;
1302                 }
1303         }
1304         rcu_read_unlock();
1305
1306         return ret; /* Audit by default */
1307 }
1308
1309 int audit_filter_type(int type)
1310 {
1311         struct audit_entry *e;
1312         int result = 0;
1313
1314         rcu_read_lock();
1315         if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1316                 goto unlock_and_return;
1317
1318         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1319                                 list) {
1320                 int i;
1321                 for (i = 0; i < e->rule.field_count; i++) {
1322                         struct audit_field *f = &e->rule.fields[i];
1323                         if (f->type == AUDIT_MSGTYPE) {
1324                                 result = audit_comparator(type, f->op, f->val);
1325                                 if (!result)
1326                                         break;
1327                         }
1328                 }
1329                 if (result)
1330                         goto unlock_and_return;
1331         }
1332 unlock_and_return:
1333         rcu_read_unlock();
1334         return result;
1335 }
1336
1337 static int update_lsm_rule(struct audit_krule *r)
1338 {
1339         struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1340         struct audit_entry *nentry;
1341         int err = 0;
1342
1343         if (!security_audit_rule_known(r))
1344                 return 0;
1345
1346         nentry = audit_dupe_rule(r);
1347         if (IS_ERR(nentry)) {
1348                 /* save the first error encountered for the
1349                  * return value */
1350                 err = PTR_ERR(nentry);
1351                 audit_panic("error updating LSM filters");
1352                 if (r->watch)
1353                         list_del(&r->rlist);
1354                 list_del_rcu(&entry->list);
1355                 list_del(&r->list);
1356         } else {
1357                 if (r->watch || r->tree)
1358                         list_replace_init(&r->rlist, &nentry->rule.rlist);
1359                 list_replace_rcu(&entry->list, &nentry->list);
1360                 list_replace(&r->list, &nentry->rule.list);
1361         }
1362         call_rcu(&entry->rcu, audit_free_rule_rcu);
1363
1364         return err;
1365 }
1366
1367 /* This function will re-initialize the lsm_rule field of all applicable rules.
1368  * It will traverse the filter lists serarching for rules that contain LSM
1369  * specific filter fields.  When such a rule is found, it is copied, the
1370  * LSM field is re-initialized, and the old rule is replaced with the
1371  * updated rule. */
1372 int audit_update_lsm_rules(void)
1373 {
1374         struct audit_krule *r, *n;
1375         int i, err = 0;
1376
1377         /* audit_filter_mutex synchronizes the writers */
1378         mutex_lock(&audit_filter_mutex);
1379
1380         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1381                 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1382                         int res = update_lsm_rule(r);
1383                         if (!err)
1384                                 err = res;
1385                 }
1386         }
1387         mutex_unlock(&audit_filter_mutex);
1388
1389         return err;
1390 }