[PATCH] audit: watching subtrees
[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/inotify.h>
31 #include <linux/selinux.h>
32 #include "audit.h"
33
34 /*
35  * Locking model:
36  *
37  * audit_filter_mutex:
38  *              Synchronizes writes and blocking reads of audit's filterlist
39  *              data.  Rcu is used to traverse the filterlist and access
40  *              contents of structs audit_entry, audit_watch and opaque
41  *              selinux rules during filtering.  If modified, these structures
42  *              must be copied and replace their counterparts in the filterlist.
43  *              An audit_parent struct is not accessed during filtering, so may
44  *              be written directly provided audit_filter_mutex is held.
45  */
46
47 /*
48  * Reference counting:
49  *
50  * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
51  *      event.  Each audit_watch holds a reference to its associated parent.
52  *
53  * audit_watch: if added to lists, lifetime is from audit_init_watch() to
54  *      audit_remove_watch().  Additionally, an audit_watch may exist
55  *      temporarily to assist in searching existing filter data.  Each
56  *      audit_krule holds a reference to its associated watch.
57  */
58
59 struct audit_parent {
60         struct list_head        ilist;  /* entry in inotify registration list */
61         struct list_head        watches; /* associated watches */
62         struct inotify_watch    wdata;  /* inotify watch data */
63         unsigned                flags;  /* status flags */
64 };
65
66 /*
67  * audit_parent status flags:
68  *
69  * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
70  * a filesystem event to ensure we're adding audit watches to a valid parent.
71  * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
72  * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
73  * we can receive while holding nameidata.
74  */
75 #define AUDIT_PARENT_INVALID    0x001
76
77 /* Audit filter lists, defined in <linux/audit.h> */
78 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
79         LIST_HEAD_INIT(audit_filter_list[0]),
80         LIST_HEAD_INIT(audit_filter_list[1]),
81         LIST_HEAD_INIT(audit_filter_list[2]),
82         LIST_HEAD_INIT(audit_filter_list[3]),
83         LIST_HEAD_INIT(audit_filter_list[4]),
84         LIST_HEAD_INIT(audit_filter_list[5]),
85 #if AUDIT_NR_FILTERS != 6
86 #error Fix audit_filter_list initialiser
87 #endif
88 };
89
90 DEFINE_MUTEX(audit_filter_mutex);
91
92 /* Inotify handle */
93 extern struct inotify_handle *audit_ih;
94
95 /* Inotify events we care about. */
96 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
97
98 void audit_free_parent(struct inotify_watch *i_watch)
99 {
100         struct audit_parent *parent;
101
102         parent = container_of(i_watch, struct audit_parent, wdata);
103         WARN_ON(!list_empty(&parent->watches));
104         kfree(parent);
105 }
106
107 static inline void audit_get_watch(struct audit_watch *watch)
108 {
109         atomic_inc(&watch->count);
110 }
111
112 static void audit_put_watch(struct audit_watch *watch)
113 {
114         if (atomic_dec_and_test(&watch->count)) {
115                 WARN_ON(watch->parent);
116                 WARN_ON(!list_empty(&watch->rules));
117                 kfree(watch->path);
118                 kfree(watch);
119         }
120 }
121
122 static void audit_remove_watch(struct audit_watch *watch)
123 {
124         list_del(&watch->wlist);
125         put_inotify_watch(&watch->parent->wdata);
126         watch->parent = NULL;
127         audit_put_watch(watch); /* match initial get */
128 }
129
130 static inline void audit_free_rule(struct audit_entry *e)
131 {
132         int i;
133
134         /* some rules don't have associated watches */
135         if (e->rule.watch)
136                 audit_put_watch(e->rule.watch);
137         if (e->rule.fields)
138                 for (i = 0; i < e->rule.field_count; i++) {
139                         struct audit_field *f = &e->rule.fields[i];
140                         kfree(f->se_str);
141                         selinux_audit_rule_free(f->se_rule);
142                 }
143         kfree(e->rule.fields);
144         kfree(e->rule.filterkey);
145         kfree(e);
146 }
147
148 void audit_free_rule_rcu(struct rcu_head *head)
149 {
150         struct audit_entry *e = container_of(head, struct audit_entry, rcu);
151         audit_free_rule(e);
152 }
153
154 /* Initialize a parent watch entry. */
155 static struct audit_parent *audit_init_parent(struct nameidata *ndp)
156 {
157         struct audit_parent *parent;
158         s32 wd;
159
160         parent = kzalloc(sizeof(*parent), GFP_KERNEL);
161         if (unlikely(!parent))
162                 return ERR_PTR(-ENOMEM);
163
164         INIT_LIST_HEAD(&parent->watches);
165         parent->flags = 0;
166
167         inotify_init_watch(&parent->wdata);
168         /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
169         get_inotify_watch(&parent->wdata);
170         wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode,
171                                AUDIT_IN_WATCH);
172         if (wd < 0) {
173                 audit_free_parent(&parent->wdata);
174                 return ERR_PTR(wd);
175         }
176
177         return parent;
178 }
179
180 /* Initialize a watch entry. */
181 static struct audit_watch *audit_init_watch(char *path)
182 {
183         struct audit_watch *watch;
184
185         watch = kzalloc(sizeof(*watch), GFP_KERNEL);
186         if (unlikely(!watch))
187                 return ERR_PTR(-ENOMEM);
188
189         INIT_LIST_HEAD(&watch->rules);
190         atomic_set(&watch->count, 1);
191         watch->path = path;
192         watch->dev = (dev_t)-1;
193         watch->ino = (unsigned long)-1;
194
195         return watch;
196 }
197
198 /* Initialize an audit filterlist entry. */
199 static inline struct audit_entry *audit_init_entry(u32 field_count)
200 {
201         struct audit_entry *entry;
202         struct audit_field *fields;
203
204         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
205         if (unlikely(!entry))
206                 return NULL;
207
208         fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
209         if (unlikely(!fields)) {
210                 kfree(entry);
211                 return NULL;
212         }
213         entry->rule.fields = fields;
214
215         return entry;
216 }
217
218 /* Unpack a filter field's string representation from user-space
219  * buffer. */
220 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
221 {
222         char *str;
223
224         if (!*bufp || (len == 0) || (len > *remain))
225                 return ERR_PTR(-EINVAL);
226
227         /* Of the currently implemented string fields, PATH_MAX
228          * defines the longest valid length.
229          */
230         if (len > PATH_MAX)
231                 return ERR_PTR(-ENAMETOOLONG);
232
233         str = kmalloc(len + 1, GFP_KERNEL);
234         if (unlikely(!str))
235                 return ERR_PTR(-ENOMEM);
236
237         memcpy(str, *bufp, len);
238         str[len] = 0;
239         *bufp += len;
240         *remain -= len;
241
242         return str;
243 }
244
245 /* Translate an inode field to kernel respresentation. */
246 static inline int audit_to_inode(struct audit_krule *krule,
247                                  struct audit_field *f)
248 {
249         if (krule->listnr != AUDIT_FILTER_EXIT ||
250             krule->watch || krule->inode_f || krule->tree)
251                 return -EINVAL;
252
253         krule->inode_f = f;
254         return 0;
255 }
256
257 /* Translate a watch string to kernel respresentation. */
258 static int audit_to_watch(struct audit_krule *krule, char *path, int len,
259                           u32 op)
260 {
261         struct audit_watch *watch;
262
263         if (!audit_ih)
264                 return -EOPNOTSUPP;
265
266         if (path[0] != '/' || path[len-1] == '/' ||
267             krule->listnr != AUDIT_FILTER_EXIT ||
268             op & ~AUDIT_EQUAL ||
269             krule->inode_f || krule->watch || krule->tree)
270                 return -EINVAL;
271
272         watch = audit_init_watch(path);
273         if (unlikely(IS_ERR(watch)))
274                 return PTR_ERR(watch);
275
276         audit_get_watch(watch);
277         krule->watch = watch;
278
279         return 0;
280 }
281
282 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
283
284 int __init audit_register_class(int class, unsigned *list)
285 {
286         __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
287         if (!p)
288                 return -ENOMEM;
289         while (*list != ~0U) {
290                 unsigned n = *list++;
291                 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
292                         kfree(p);
293                         return -EINVAL;
294                 }
295                 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
296         }
297         if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
298                 kfree(p);
299                 return -EINVAL;
300         }
301         classes[class] = p;
302         return 0;
303 }
304
305 int audit_match_class(int class, unsigned syscall)
306 {
307         if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
308                 return 0;
309         if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
310                 return 0;
311         return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
312 }
313
314 #ifdef CONFIG_AUDITSYSCALL
315 static inline int audit_match_class_bits(int class, u32 *mask)
316 {
317         int i;
318
319         if (classes[class]) {
320                 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
321                         if (mask[i] & classes[class][i])
322                                 return 0;
323         }
324         return 1;
325 }
326
327 static int audit_match_signal(struct audit_entry *entry)
328 {
329         struct audit_field *arch = entry->rule.arch_f;
330
331         if (!arch) {
332                 /* When arch is unspecified, we must check both masks on biarch
333                  * as syscall number alone is ambiguous. */
334                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
335                                                entry->rule.mask) &&
336                         audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
337                                                entry->rule.mask));
338         }
339
340         switch(audit_classify_arch(arch->val)) {
341         case 0: /* native */
342                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
343                                                entry->rule.mask));
344         case 1: /* 32bit on biarch */
345                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
346                                                entry->rule.mask));
347         default:
348                 return 1;
349         }
350 }
351 #endif
352
353 /* Common user-space to kernel rule translation. */
354 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
355 {
356         unsigned listnr;
357         struct audit_entry *entry;
358         int i, err;
359
360         err = -EINVAL;
361         listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
362         switch(listnr) {
363         default:
364                 goto exit_err;
365         case AUDIT_FILTER_USER:
366         case AUDIT_FILTER_TYPE:
367 #ifdef CONFIG_AUDITSYSCALL
368         case AUDIT_FILTER_ENTRY:
369         case AUDIT_FILTER_EXIT:
370         case AUDIT_FILTER_TASK:
371 #endif
372                 ;
373         }
374         if (unlikely(rule->action == AUDIT_POSSIBLE)) {
375                 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
376                 goto exit_err;
377         }
378         if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
379                 goto exit_err;
380         if (rule->field_count > AUDIT_MAX_FIELDS)
381                 goto exit_err;
382
383         err = -ENOMEM;
384         entry = audit_init_entry(rule->field_count);
385         if (!entry)
386                 goto exit_err;
387
388         entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
389         entry->rule.listnr = listnr;
390         entry->rule.action = rule->action;
391         entry->rule.field_count = rule->field_count;
392
393         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
394                 entry->rule.mask[i] = rule->mask[i];
395
396         for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
397                 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
398                 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
399                 __u32 *class;
400
401                 if (!(*p & AUDIT_BIT(bit)))
402                         continue;
403                 *p &= ~AUDIT_BIT(bit);
404                 class = classes[i];
405                 if (class) {
406                         int j;
407                         for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
408                                 entry->rule.mask[j] |= class[j];
409                 }
410         }
411
412         return entry;
413
414 exit_err:
415         return ERR_PTR(err);
416 }
417
418 /* Translate struct audit_rule to kernel's rule respresentation.
419  * Exists for backward compatibility with userspace. */
420 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
421 {
422         struct audit_entry *entry;
423         struct audit_field *f;
424         int err = 0;
425         int i;
426
427         entry = audit_to_entry_common(rule);
428         if (IS_ERR(entry))
429                 goto exit_nofree;
430
431         for (i = 0; i < rule->field_count; i++) {
432                 struct audit_field *f = &entry->rule.fields[i];
433
434                 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
435                 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
436                 f->val = rule->values[i];
437
438                 err = -EINVAL;
439                 switch(f->type) {
440                 default:
441                         goto exit_free;
442                 case AUDIT_PID:
443                 case AUDIT_UID:
444                 case AUDIT_EUID:
445                 case AUDIT_SUID:
446                 case AUDIT_FSUID:
447                 case AUDIT_GID:
448                 case AUDIT_EGID:
449                 case AUDIT_SGID:
450                 case AUDIT_FSGID:
451                 case AUDIT_LOGINUID:
452                 case AUDIT_PERS:
453                 case AUDIT_MSGTYPE:
454                 case AUDIT_PPID:
455                 case AUDIT_DEVMAJOR:
456                 case AUDIT_DEVMINOR:
457                 case AUDIT_EXIT:
458                 case AUDIT_SUCCESS:
459                         /* bit ops are only useful on syscall args */
460                         if (f->op == AUDIT_BIT_MASK ||
461                                                 f->op == AUDIT_BIT_TEST) {
462                                 err = -EINVAL;
463                                 goto exit_free;
464                         }
465                         break;
466                 case AUDIT_ARG0:
467                 case AUDIT_ARG1:
468                 case AUDIT_ARG2:
469                 case AUDIT_ARG3:
470                         break;
471                 /* arch is only allowed to be = or != */
472                 case AUDIT_ARCH:
473                         if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL)
474                                         && (f->op != AUDIT_NEGATE) && (f->op)) {
475                                 err = -EINVAL;
476                                 goto exit_free;
477                         }
478                         entry->rule.arch_f = f;
479                         break;
480                 case AUDIT_PERM:
481                         if (f->val & ~15)
482                                 goto exit_free;
483                         break;
484                 case AUDIT_INODE:
485                         err = audit_to_inode(&entry->rule, f);
486                         if (err)
487                                 goto exit_free;
488                         break;
489                 }
490
491                 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
492
493                 /* Support for legacy operators where
494                  * AUDIT_NEGATE bit signifies != and otherwise assumes == */
495                 if (f->op & AUDIT_NEGATE)
496                         f->op = AUDIT_NOT_EQUAL;
497                 else if (!f->op)
498                         f->op = AUDIT_EQUAL;
499                 else if (f->op == AUDIT_OPERATORS) {
500                         err = -EINVAL;
501                         goto exit_free;
502                 }
503         }
504
505         f = entry->rule.inode_f;
506         if (f) {
507                 switch(f->op) {
508                 case AUDIT_NOT_EQUAL:
509                         entry->rule.inode_f = NULL;
510                 case AUDIT_EQUAL:
511                         break;
512                 default:
513                         err = -EINVAL;
514                         goto exit_free;
515                 }
516         }
517
518 exit_nofree:
519         return entry;
520
521 exit_free:
522         audit_free_rule(entry);
523         return ERR_PTR(err);
524 }
525
526 /* Translate struct audit_rule_data to kernel's rule respresentation. */
527 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
528                                                size_t datasz)
529 {
530         int err = 0;
531         struct audit_entry *entry;
532         struct audit_field *f;
533         void *bufp;
534         size_t remain = datasz - sizeof(struct audit_rule_data);
535         int i;
536         char *str;
537
538         entry = audit_to_entry_common((struct audit_rule *)data);
539         if (IS_ERR(entry))
540                 goto exit_nofree;
541
542         bufp = data->buf;
543         entry->rule.vers_ops = 2;
544         for (i = 0; i < data->field_count; i++) {
545                 struct audit_field *f = &entry->rule.fields[i];
546
547                 err = -EINVAL;
548                 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
549                     data->fieldflags[i] & ~AUDIT_OPERATORS)
550                         goto exit_free;
551
552                 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
553                 f->type = data->fields[i];
554                 f->val = data->values[i];
555                 f->se_str = NULL;
556                 f->se_rule = NULL;
557                 switch(f->type) {
558                 case AUDIT_PID:
559                 case AUDIT_UID:
560                 case AUDIT_EUID:
561                 case AUDIT_SUID:
562                 case AUDIT_FSUID:
563                 case AUDIT_GID:
564                 case AUDIT_EGID:
565                 case AUDIT_SGID:
566                 case AUDIT_FSGID:
567                 case AUDIT_LOGINUID:
568                 case AUDIT_PERS:
569                 case AUDIT_MSGTYPE:
570                 case AUDIT_PPID:
571                 case AUDIT_DEVMAJOR:
572                 case AUDIT_DEVMINOR:
573                 case AUDIT_EXIT:
574                 case AUDIT_SUCCESS:
575                 case AUDIT_ARG0:
576                 case AUDIT_ARG1:
577                 case AUDIT_ARG2:
578                 case AUDIT_ARG3:
579                         break;
580                 case AUDIT_ARCH:
581                         entry->rule.arch_f = f;
582                         break;
583                 case AUDIT_SUBJ_USER:
584                 case AUDIT_SUBJ_ROLE:
585                 case AUDIT_SUBJ_TYPE:
586                 case AUDIT_SUBJ_SEN:
587                 case AUDIT_SUBJ_CLR:
588                 case AUDIT_OBJ_USER:
589                 case AUDIT_OBJ_ROLE:
590                 case AUDIT_OBJ_TYPE:
591                 case AUDIT_OBJ_LEV_LOW:
592                 case AUDIT_OBJ_LEV_HIGH:
593                         str = audit_unpack_string(&bufp, &remain, f->val);
594                         if (IS_ERR(str))
595                                 goto exit_free;
596                         entry->rule.buflen += f->val;
597
598                         err = selinux_audit_rule_init(f->type, f->op, str,
599                                                       &f->se_rule);
600                         /* Keep currently invalid fields around in case they
601                          * become valid after a policy reload. */
602                         if (err == -EINVAL) {
603                                 printk(KERN_WARNING "audit rule for selinux "
604                                        "\'%s\' is invalid\n",  str);
605                                 err = 0;
606                         }
607                         if (err) {
608                                 kfree(str);
609                                 goto exit_free;
610                         } else
611                                 f->se_str = str;
612                         break;
613                 case AUDIT_WATCH:
614                         str = audit_unpack_string(&bufp, &remain, f->val);
615                         if (IS_ERR(str))
616                                 goto exit_free;
617                         entry->rule.buflen += f->val;
618
619                         err = audit_to_watch(&entry->rule, str, f->val, f->op);
620                         if (err) {
621                                 kfree(str);
622                                 goto exit_free;
623                         }
624                         break;
625                 case AUDIT_DIR:
626                         str = audit_unpack_string(&bufp, &remain, f->val);
627                         if (IS_ERR(str))
628                                 goto exit_free;
629                         entry->rule.buflen += f->val;
630
631                         err = audit_make_tree(&entry->rule, str, f->op);
632                         kfree(str);
633                         if (err)
634                                 goto exit_free;
635                         break;
636                 case AUDIT_INODE:
637                         err = audit_to_inode(&entry->rule, f);
638                         if (err)
639                                 goto exit_free;
640                         break;
641                 case AUDIT_FILTERKEY:
642                         err = -EINVAL;
643                         if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
644                                 goto exit_free;
645                         str = audit_unpack_string(&bufp, &remain, f->val);
646                         if (IS_ERR(str))
647                                 goto exit_free;
648                         entry->rule.buflen += f->val;
649                         entry->rule.filterkey = str;
650                         break;
651                 case AUDIT_PERM:
652                         if (f->val & ~15)
653                                 goto exit_free;
654                         break;
655                 default:
656                         goto exit_free;
657                 }
658         }
659
660         f = entry->rule.inode_f;
661         if (f) {
662                 switch(f->op) {
663                 case AUDIT_NOT_EQUAL:
664                         entry->rule.inode_f = NULL;
665                 case AUDIT_EQUAL:
666                         break;
667                 default:
668                         err = -EINVAL;
669                         goto exit_free;
670                 }
671         }
672
673 exit_nofree:
674         return entry;
675
676 exit_free:
677         audit_free_rule(entry);
678         return ERR_PTR(err);
679 }
680
681 /* Pack a filter field's string representation into data block. */
682 static inline size_t audit_pack_string(void **bufp, const char *str)
683 {
684         size_t len = strlen(str);
685
686         memcpy(*bufp, str, len);
687         *bufp += len;
688
689         return len;
690 }
691
692 /* Translate kernel rule respresentation to struct audit_rule.
693  * Exists for backward compatibility with userspace. */
694 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
695 {
696         struct audit_rule *rule;
697         int i;
698
699         rule = kzalloc(sizeof(*rule), GFP_KERNEL);
700         if (unlikely(!rule))
701                 return NULL;
702
703         rule->flags = krule->flags | krule->listnr;
704         rule->action = krule->action;
705         rule->field_count = krule->field_count;
706         for (i = 0; i < rule->field_count; i++) {
707                 rule->values[i] = krule->fields[i].val;
708                 rule->fields[i] = krule->fields[i].type;
709
710                 if (krule->vers_ops == 1) {
711                         if (krule->fields[i].op & AUDIT_NOT_EQUAL)
712                                 rule->fields[i] |= AUDIT_NEGATE;
713                 } else {
714                         rule->fields[i] |= krule->fields[i].op;
715                 }
716         }
717         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
718
719         return rule;
720 }
721
722 /* Translate kernel rule respresentation to struct audit_rule_data. */
723 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
724 {
725         struct audit_rule_data *data;
726         void *bufp;
727         int i;
728
729         data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
730         if (unlikely(!data))
731                 return NULL;
732         memset(data, 0, sizeof(*data));
733
734         data->flags = krule->flags | krule->listnr;
735         data->action = krule->action;
736         data->field_count = krule->field_count;
737         bufp = data->buf;
738         for (i = 0; i < data->field_count; i++) {
739                 struct audit_field *f = &krule->fields[i];
740
741                 data->fields[i] = f->type;
742                 data->fieldflags[i] = f->op;
743                 switch(f->type) {
744                 case AUDIT_SUBJ_USER:
745                 case AUDIT_SUBJ_ROLE:
746                 case AUDIT_SUBJ_TYPE:
747                 case AUDIT_SUBJ_SEN:
748                 case AUDIT_SUBJ_CLR:
749                 case AUDIT_OBJ_USER:
750                 case AUDIT_OBJ_ROLE:
751                 case AUDIT_OBJ_TYPE:
752                 case AUDIT_OBJ_LEV_LOW:
753                 case AUDIT_OBJ_LEV_HIGH:
754                         data->buflen += data->values[i] =
755                                 audit_pack_string(&bufp, f->se_str);
756                         break;
757                 case AUDIT_WATCH:
758                         data->buflen += data->values[i] =
759                                 audit_pack_string(&bufp, krule->watch->path);
760                         break;
761                 case AUDIT_DIR:
762                         data->buflen += data->values[i] =
763                                 audit_pack_string(&bufp,
764                                                   audit_tree_path(krule->tree));
765                         break;
766                 case AUDIT_FILTERKEY:
767                         data->buflen += data->values[i] =
768                                 audit_pack_string(&bufp, krule->filterkey);
769                         break;
770                 default:
771                         data->values[i] = f->val;
772                 }
773         }
774         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
775
776         return data;
777 }
778
779 /* Compare two rules in kernel format.  Considered success if rules
780  * don't match. */
781 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
782 {
783         int i;
784
785         if (a->flags != b->flags ||
786             a->listnr != b->listnr ||
787             a->action != b->action ||
788             a->field_count != b->field_count)
789                 return 1;
790
791         for (i = 0; i < a->field_count; i++) {
792                 if (a->fields[i].type != b->fields[i].type ||
793                     a->fields[i].op != b->fields[i].op)
794                         return 1;
795
796                 switch(a->fields[i].type) {
797                 case AUDIT_SUBJ_USER:
798                 case AUDIT_SUBJ_ROLE:
799                 case AUDIT_SUBJ_TYPE:
800                 case AUDIT_SUBJ_SEN:
801                 case AUDIT_SUBJ_CLR:
802                 case AUDIT_OBJ_USER:
803                 case AUDIT_OBJ_ROLE:
804                 case AUDIT_OBJ_TYPE:
805                 case AUDIT_OBJ_LEV_LOW:
806                 case AUDIT_OBJ_LEV_HIGH:
807                         if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
808                                 return 1;
809                         break;
810                 case AUDIT_WATCH:
811                         if (strcmp(a->watch->path, b->watch->path))
812                                 return 1;
813                         break;
814                 case AUDIT_DIR:
815                         if (strcmp(audit_tree_path(a->tree),
816                                    audit_tree_path(b->tree)))
817                                 return 1;
818                         break;
819                 case AUDIT_FILTERKEY:
820                         /* both filterkeys exist based on above type compare */
821                         if (strcmp(a->filterkey, b->filterkey))
822                                 return 1;
823                         break;
824                 default:
825                         if (a->fields[i].val != b->fields[i].val)
826                                 return 1;
827                 }
828         }
829
830         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
831                 if (a->mask[i] != b->mask[i])
832                         return 1;
833
834         return 0;
835 }
836
837 /* Duplicate the given audit watch.  The new watch's rules list is initialized
838  * to an empty list and wlist is undefined. */
839 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
840 {
841         char *path;
842         struct audit_watch *new;
843
844         path = kstrdup(old->path, GFP_KERNEL);
845         if (unlikely(!path))
846                 return ERR_PTR(-ENOMEM);
847
848         new = audit_init_watch(path);
849         if (unlikely(IS_ERR(new))) {
850                 kfree(path);
851                 goto out;
852         }
853
854         new->dev = old->dev;
855         new->ino = old->ino;
856         get_inotify_watch(&old->parent->wdata);
857         new->parent = old->parent;
858
859 out:
860         return new;
861 }
862
863 /* Duplicate selinux field information.  The se_rule is opaque, so must be
864  * re-initialized. */
865 static inline int audit_dupe_selinux_field(struct audit_field *df,
866                                            struct audit_field *sf)
867 {
868         int ret = 0;
869         char *se_str;
870
871         /* our own copy of se_str */
872         se_str = kstrdup(sf->se_str, GFP_KERNEL);
873         if (unlikely(!se_str))
874                 return -ENOMEM;
875         df->se_str = se_str;
876
877         /* our own (refreshed) copy of se_rule */
878         ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
879                                       &df->se_rule);
880         /* Keep currently invalid fields around in case they
881          * become valid after a policy reload. */
882         if (ret == -EINVAL) {
883                 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
884                        "invalid\n", df->se_str);
885                 ret = 0;
886         }
887
888         return ret;
889 }
890
891 /* Duplicate an audit rule.  This will be a deep copy with the exception
892  * of the watch - that pointer is carried over.  The selinux specific fields
893  * will be updated in the copy.  The point is to be able to replace the old
894  * rule with the new rule in the filterlist, then free the old rule.
895  * The rlist element is undefined; list manipulations are handled apart from
896  * the initial copy. */
897 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
898                                            struct audit_watch *watch)
899 {
900         u32 fcount = old->field_count;
901         struct audit_entry *entry;
902         struct audit_krule *new;
903         char *fk;
904         int i, err = 0;
905
906         entry = audit_init_entry(fcount);
907         if (unlikely(!entry))
908                 return ERR_PTR(-ENOMEM);
909
910         new = &entry->rule;
911         new->vers_ops = old->vers_ops;
912         new->flags = old->flags;
913         new->listnr = old->listnr;
914         new->action = old->action;
915         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
916                 new->mask[i] = old->mask[i];
917         new->buflen = old->buflen;
918         new->inode_f = old->inode_f;
919         new->watch = NULL;
920         new->field_count = old->field_count;
921         /*
922          * note that we are OK with not refcounting here; audit_match_tree()
923          * never dereferences tree and we can't get false positives there
924          * since we'd have to have rule gone from the list *and* removed
925          * before the chunks found by lookup had been allocated, i.e. before
926          * the beginning of list scan.
927          */
928         new->tree = old->tree;
929         memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
930
931         /* deep copy this information, updating the se_rule fields, because
932          * the originals will all be freed when the old rule is freed. */
933         for (i = 0; i < fcount; i++) {
934                 switch (new->fields[i].type) {
935                 case AUDIT_SUBJ_USER:
936                 case AUDIT_SUBJ_ROLE:
937                 case AUDIT_SUBJ_TYPE:
938                 case AUDIT_SUBJ_SEN:
939                 case AUDIT_SUBJ_CLR:
940                 case AUDIT_OBJ_USER:
941                 case AUDIT_OBJ_ROLE:
942                 case AUDIT_OBJ_TYPE:
943                 case AUDIT_OBJ_LEV_LOW:
944                 case AUDIT_OBJ_LEV_HIGH:
945                         err = audit_dupe_selinux_field(&new->fields[i],
946                                                        &old->fields[i]);
947                         break;
948                 case AUDIT_FILTERKEY:
949                         fk = kstrdup(old->filterkey, GFP_KERNEL);
950                         if (unlikely(!fk))
951                                 err = -ENOMEM;
952                         else
953                                 new->filterkey = fk;
954                 }
955                 if (err) {
956                         audit_free_rule(entry);
957                         return ERR_PTR(err);
958                 }
959         }
960
961         if (watch) {
962                 audit_get_watch(watch);
963                 new->watch = watch;
964         }
965
966         return entry;
967 }
968
969 /* Update inode info in audit rules based on filesystem event. */
970 static void audit_update_watch(struct audit_parent *parent,
971                                const char *dname, dev_t dev,
972                                unsigned long ino, unsigned invalidating)
973 {
974         struct audit_watch *owatch, *nwatch, *nextw;
975         struct audit_krule *r, *nextr;
976         struct audit_entry *oentry, *nentry;
977         struct audit_buffer *ab;
978
979         mutex_lock(&audit_filter_mutex);
980         list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
981                 if (audit_compare_dname_path(dname, owatch->path, NULL))
982                         continue;
983
984                 /* If the update involves invalidating rules, do the inode-based
985                  * filtering now, so we don't omit records. */
986                 if (invalidating && current->audit_context &&
987                     audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
988                         audit_set_auditable(current->audit_context);
989
990                 nwatch = audit_dupe_watch(owatch);
991                 if (unlikely(IS_ERR(nwatch))) {
992                         mutex_unlock(&audit_filter_mutex);
993                         audit_panic("error updating watch, skipping");
994                         return;
995                 }
996                 nwatch->dev = dev;
997                 nwatch->ino = ino;
998
999                 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
1000
1001                         oentry = container_of(r, struct audit_entry, rule);
1002                         list_del(&oentry->rule.rlist);
1003                         list_del_rcu(&oentry->list);
1004
1005                         nentry = audit_dupe_rule(&oentry->rule, nwatch);
1006                         if (unlikely(IS_ERR(nentry)))
1007                                 audit_panic("error updating watch, removing");
1008                         else {
1009                                 int h = audit_hash_ino((u32)ino);
1010                                 list_add(&nentry->rule.rlist, &nwatch->rules);
1011                                 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
1012                         }
1013
1014                         call_rcu(&oentry->rcu, audit_free_rule_rcu);
1015                 }
1016
1017                 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1018                 audit_log_format(ab, "op=updated rules specifying path=");
1019                 audit_log_untrustedstring(ab, owatch->path);
1020                 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
1021                 audit_log_format(ab, " list=%d res=1", r->listnr);
1022                 audit_log_end(ab);
1023
1024                 audit_remove_watch(owatch);
1025                 goto add_watch_to_parent; /* event applies to a single watch */
1026         }
1027         mutex_unlock(&audit_filter_mutex);
1028         return;
1029
1030 add_watch_to_parent:
1031         list_add(&nwatch->wlist, &parent->watches);
1032         mutex_unlock(&audit_filter_mutex);
1033         return;
1034 }
1035
1036 /* Remove all watches & rules associated with a parent that is going away. */
1037 static void audit_remove_parent_watches(struct audit_parent *parent)
1038 {
1039         struct audit_watch *w, *nextw;
1040         struct audit_krule *r, *nextr;
1041         struct audit_entry *e;
1042         struct audit_buffer *ab;
1043
1044         mutex_lock(&audit_filter_mutex);
1045         parent->flags |= AUDIT_PARENT_INVALID;
1046         list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
1047                 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
1048                         e = container_of(r, struct audit_entry, rule);
1049
1050                         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1051                         audit_log_format(ab, "op=remove rule path=");
1052                         audit_log_untrustedstring(ab, w->path);
1053                         if (r->filterkey) {
1054                                 audit_log_format(ab, " key=");
1055                                 audit_log_untrustedstring(ab, r->filterkey);
1056                         } else
1057                                 audit_log_format(ab, " key=(null)");
1058                         audit_log_format(ab, " list=%d res=1", r->listnr);
1059                         audit_log_end(ab);
1060
1061                         list_del(&r->rlist);
1062                         list_del_rcu(&e->list);
1063                         call_rcu(&e->rcu, audit_free_rule_rcu);
1064                 }
1065                 audit_remove_watch(w);
1066         }
1067         mutex_unlock(&audit_filter_mutex);
1068 }
1069
1070 /* Unregister inotify watches for parents on in_list.
1071  * Generates an IN_IGNORED event. */
1072 static void audit_inotify_unregister(struct list_head *in_list)
1073 {
1074         struct audit_parent *p, *n;
1075
1076         list_for_each_entry_safe(p, n, in_list, ilist) {
1077                 list_del(&p->ilist);
1078                 inotify_rm_watch(audit_ih, &p->wdata);
1079                 /* the put matching the get in audit_do_del_rule() */
1080                 put_inotify_watch(&p->wdata);
1081         }
1082 }
1083
1084 /* Find an existing audit rule.
1085  * Caller must hold audit_filter_mutex to prevent stale rule data. */
1086 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
1087                                            struct list_head *list)
1088 {
1089         struct audit_entry *e, *found = NULL;
1090         int h;
1091
1092         if (entry->rule.watch) {
1093                 /* we don't know the inode number, so must walk entire hash */
1094                 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
1095                         list = &audit_inode_hash[h];
1096                         list_for_each_entry(e, list, list)
1097                                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1098                                         found = e;
1099                                         goto out;
1100                                 }
1101                 }
1102                 goto out;
1103         }
1104
1105         list_for_each_entry(e, list, list)
1106                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1107                         found = e;
1108                         goto out;
1109                 }
1110
1111 out:
1112         return found;
1113 }
1114
1115 /* Get path information necessary for adding watches. */
1116 static int audit_get_nd(char *path, struct nameidata **ndp,
1117                         struct nameidata **ndw)
1118 {
1119         struct nameidata *ndparent, *ndwatch;
1120         int err;
1121
1122         ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1123         if (unlikely(!ndparent))
1124                 return -ENOMEM;
1125
1126         ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1127         if (unlikely(!ndwatch)) {
1128                 kfree(ndparent);
1129                 return -ENOMEM;
1130         }
1131
1132         err = path_lookup(path, LOOKUP_PARENT, ndparent);
1133         if (err) {
1134                 kfree(ndparent);
1135                 kfree(ndwatch);
1136                 return err;
1137         }
1138
1139         err = path_lookup(path, 0, ndwatch);
1140         if (err) {
1141                 kfree(ndwatch);
1142                 ndwatch = NULL;
1143         }
1144
1145         *ndp = ndparent;
1146         *ndw = ndwatch;
1147
1148         return 0;
1149 }
1150
1151 /* Release resources used for watch path information. */
1152 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1153 {
1154         if (ndp) {
1155                 path_release(ndp);
1156                 kfree(ndp);
1157         }
1158         if (ndw) {
1159                 path_release(ndw);
1160                 kfree(ndw);
1161         }
1162 }
1163
1164 /* Associate the given rule with an existing parent inotify_watch.
1165  * Caller must hold audit_filter_mutex. */
1166 static void audit_add_to_parent(struct audit_krule *krule,
1167                                 struct audit_parent *parent)
1168 {
1169         struct audit_watch *w, *watch = krule->watch;
1170         int watch_found = 0;
1171
1172         list_for_each_entry(w, &parent->watches, wlist) {
1173                 if (strcmp(watch->path, w->path))
1174                         continue;
1175
1176                 watch_found = 1;
1177
1178                 /* put krule's and initial refs to temporary watch */
1179                 audit_put_watch(watch);
1180                 audit_put_watch(watch);
1181
1182                 audit_get_watch(w);
1183                 krule->watch = watch = w;
1184                 break;
1185         }
1186
1187         if (!watch_found) {
1188                 get_inotify_watch(&parent->wdata);
1189                 watch->parent = parent;
1190
1191                 list_add(&watch->wlist, &parent->watches);
1192         }
1193         list_add(&krule->rlist, &watch->rules);
1194 }
1195
1196 /* Find a matching watch entry, or add this one.
1197  * Caller must hold audit_filter_mutex. */
1198 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1199                            struct nameidata *ndw)
1200 {
1201         struct audit_watch *watch = krule->watch;
1202         struct inotify_watch *i_watch;
1203         struct audit_parent *parent;
1204         int ret = 0;
1205
1206         /* update watch filter fields */
1207         if (ndw) {
1208                 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1209                 watch->ino = ndw->dentry->d_inode->i_ino;
1210         }
1211
1212         /* The audit_filter_mutex must not be held during inotify calls because
1213          * we hold it during inotify event callback processing.  If an existing
1214          * inotify watch is found, inotify_find_watch() grabs a reference before
1215          * returning.
1216          */
1217         mutex_unlock(&audit_filter_mutex);
1218
1219         if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1220                 parent = audit_init_parent(ndp);
1221                 if (IS_ERR(parent)) {
1222                         /* caller expects mutex locked */
1223                         mutex_lock(&audit_filter_mutex);
1224                         return PTR_ERR(parent);
1225                 }
1226         } else
1227                 parent = container_of(i_watch, struct audit_parent, wdata);
1228
1229         mutex_lock(&audit_filter_mutex);
1230
1231         /* parent was moved before we took audit_filter_mutex */
1232         if (parent->flags & AUDIT_PARENT_INVALID)
1233                 ret = -ENOENT;
1234         else
1235                 audit_add_to_parent(krule, parent);
1236
1237         /* match get in audit_init_parent or inotify_find_watch */
1238         put_inotify_watch(&parent->wdata);
1239         return ret;
1240 }
1241
1242 /* Add rule to given filterlist if not a duplicate. */
1243 static inline int audit_add_rule(struct audit_entry *entry,
1244                                  struct list_head *list)
1245 {
1246         struct audit_entry *e;
1247         struct audit_field *inode_f = entry->rule.inode_f;
1248         struct audit_watch *watch = entry->rule.watch;
1249         struct audit_tree *tree = entry->rule.tree;
1250         struct nameidata *ndp = NULL, *ndw = NULL;
1251         int h, err;
1252 #ifdef CONFIG_AUDITSYSCALL
1253         int dont_count = 0;
1254
1255         /* If either of these, don't count towards total */
1256         if (entry->rule.listnr == AUDIT_FILTER_USER ||
1257                 entry->rule.listnr == AUDIT_FILTER_TYPE)
1258                 dont_count = 1;
1259 #endif
1260
1261         if (inode_f) {
1262                 h = audit_hash_ino(inode_f->val);
1263                 list = &audit_inode_hash[h];
1264         }
1265
1266         mutex_lock(&audit_filter_mutex);
1267         e = audit_find_rule(entry, list);
1268         mutex_unlock(&audit_filter_mutex);
1269         if (e) {
1270                 err = -EEXIST;
1271                 /* normally audit_add_tree_rule() will free it on failure */
1272                 if (tree)
1273                         audit_put_tree(tree);
1274                 goto error;
1275         }
1276
1277         /* Avoid calling path_lookup under audit_filter_mutex. */
1278         if (watch) {
1279                 err = audit_get_nd(watch->path, &ndp, &ndw);
1280                 if (err)
1281                         goto error;
1282         }
1283
1284         mutex_lock(&audit_filter_mutex);
1285         if (watch) {
1286                 /* audit_filter_mutex is dropped and re-taken during this call */
1287                 err = audit_add_watch(&entry->rule, ndp, ndw);
1288                 if (err) {
1289                         mutex_unlock(&audit_filter_mutex);
1290                         goto error;
1291                 }
1292                 h = audit_hash_ino((u32)watch->ino);
1293                 list = &audit_inode_hash[h];
1294         }
1295         if (tree) {
1296                 err = audit_add_tree_rule(&entry->rule);
1297                 if (err) {
1298                         mutex_unlock(&audit_filter_mutex);
1299                         goto error;
1300                 }
1301         }
1302
1303         if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1304                 list_add_rcu(&entry->list, list);
1305                 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1306         } else {
1307                 list_add_tail_rcu(&entry->list, list);
1308         }
1309 #ifdef CONFIG_AUDITSYSCALL
1310         if (!dont_count)
1311                 audit_n_rules++;
1312
1313         if (!audit_match_signal(entry))
1314                 audit_signals++;
1315 #endif
1316         mutex_unlock(&audit_filter_mutex);
1317
1318         audit_put_nd(ndp, ndw);         /* NULL args OK */
1319         return 0;
1320
1321 error:
1322         audit_put_nd(ndp, ndw);         /* NULL args OK */
1323         if (watch)
1324                 audit_put_watch(watch); /* tmp watch, matches initial get */
1325         return err;
1326 }
1327
1328 /* Remove an existing rule from filterlist. */
1329 static inline int audit_del_rule(struct audit_entry *entry,
1330                                  struct list_head *list)
1331 {
1332         struct audit_entry  *e;
1333         struct audit_field *inode_f = entry->rule.inode_f;
1334         struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1335         struct audit_tree *tree = entry->rule.tree;
1336         LIST_HEAD(inotify_list);
1337         int h, ret = 0;
1338 #ifdef CONFIG_AUDITSYSCALL
1339         int dont_count = 0;
1340
1341         /* If either of these, don't count towards total */
1342         if (entry->rule.listnr == AUDIT_FILTER_USER ||
1343                 entry->rule.listnr == AUDIT_FILTER_TYPE)
1344                 dont_count = 1;
1345 #endif
1346
1347         if (inode_f) {
1348                 h = audit_hash_ino(inode_f->val);
1349                 list = &audit_inode_hash[h];
1350         }
1351
1352         mutex_lock(&audit_filter_mutex);
1353         e = audit_find_rule(entry, list);
1354         if (!e) {
1355                 mutex_unlock(&audit_filter_mutex);
1356                 ret = -ENOENT;
1357                 goto out;
1358         }
1359
1360         watch = e->rule.watch;
1361         if (watch) {
1362                 struct audit_parent *parent = watch->parent;
1363
1364                 list_del(&e->rule.rlist);
1365
1366                 if (list_empty(&watch->rules)) {
1367                         audit_remove_watch(watch);
1368
1369                         if (list_empty(&parent->watches)) {
1370                                 /* Put parent on the inotify un-registration
1371                                  * list.  Grab a reference before releasing
1372                                  * audit_filter_mutex, to be released in
1373                                  * audit_inotify_unregister(). */
1374                                 list_add(&parent->ilist, &inotify_list);
1375                                 get_inotify_watch(&parent->wdata);
1376                         }
1377                 }
1378         }
1379
1380         if (e->rule.tree)
1381                 audit_remove_tree_rule(&e->rule);
1382
1383         list_del_rcu(&e->list);
1384         call_rcu(&e->rcu, audit_free_rule_rcu);
1385
1386 #ifdef CONFIG_AUDITSYSCALL
1387         if (!dont_count)
1388                 audit_n_rules--;
1389
1390         if (!audit_match_signal(entry))
1391                 audit_signals--;
1392 #endif
1393         mutex_unlock(&audit_filter_mutex);
1394
1395         if (!list_empty(&inotify_list))
1396                 audit_inotify_unregister(&inotify_list);
1397
1398 out:
1399         if (tmp_watch)
1400                 audit_put_watch(tmp_watch); /* match initial get */
1401         if (tree)
1402                 audit_put_tree(tree);   /* that's the temporary one */
1403
1404         return ret;
1405 }
1406
1407 /* List rules using struct audit_rule.  Exists for backward
1408  * compatibility with userspace. */
1409 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1410 {
1411         struct sk_buff *skb;
1412         struct audit_entry *entry;
1413         int i;
1414
1415         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1416          * iterator to sync with list writers. */
1417         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1418                 list_for_each_entry(entry, &audit_filter_list[i], list) {
1419                         struct audit_rule *rule;
1420
1421                         rule = audit_krule_to_rule(&entry->rule);
1422                         if (unlikely(!rule))
1423                                 break;
1424                         skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1425                                          rule, sizeof(*rule));
1426                         if (skb)
1427                                 skb_queue_tail(q, skb);
1428                         kfree(rule);
1429                 }
1430         }
1431         for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1432                 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1433                         struct audit_rule *rule;
1434
1435                         rule = audit_krule_to_rule(&entry->rule);
1436                         if (unlikely(!rule))
1437                                 break;
1438                         skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1439                                          rule, sizeof(*rule));
1440                         if (skb)
1441                                 skb_queue_tail(q, skb);
1442                         kfree(rule);
1443                 }
1444         }
1445         skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1446         if (skb)
1447                 skb_queue_tail(q, skb);
1448 }
1449
1450 /* List rules using struct audit_rule_data. */
1451 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1452 {
1453         struct sk_buff *skb;
1454         struct audit_entry *e;
1455         int i;
1456
1457         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1458          * iterator to sync with list writers. */
1459         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1460                 list_for_each_entry(e, &audit_filter_list[i], list) {
1461                         struct audit_rule_data *data;
1462
1463                         data = audit_krule_to_data(&e->rule);
1464                         if (unlikely(!data))
1465                                 break;
1466                         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1467                                          data, sizeof(*data) + data->buflen);
1468                         if (skb)
1469                                 skb_queue_tail(q, skb);
1470                         kfree(data);
1471                 }
1472         }
1473         for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1474                 list_for_each_entry(e, &audit_inode_hash[i], list) {
1475                         struct audit_rule_data *data;
1476
1477                         data = audit_krule_to_data(&e->rule);
1478                         if (unlikely(!data))
1479                                 break;
1480                         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1481                                          data, sizeof(*data) + data->buflen);
1482                         if (skb)
1483                                 skb_queue_tail(q, skb);
1484                         kfree(data);
1485                 }
1486         }
1487         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1488         if (skb)
1489                 skb_queue_tail(q, skb);
1490 }
1491
1492 /* Log rule additions and removals */
1493 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1494                                   struct audit_krule *rule, int res)
1495 {
1496         struct audit_buffer *ab;
1497
1498         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1499         if (!ab)
1500                 return;
1501         audit_log_format(ab, "auid=%u", loginuid);
1502         if (sid) {
1503                 char *ctx = NULL;
1504                 u32 len;
1505                 if (selinux_sid_to_string(sid, &ctx, &len))
1506                         audit_log_format(ab, " ssid=%u", sid);
1507                 else
1508                         audit_log_format(ab, " subj=%s", ctx);
1509                 kfree(ctx);
1510         }
1511         audit_log_format(ab, " op=%s rule key=", action);
1512         if (rule->filterkey)
1513                 audit_log_untrustedstring(ab, rule->filterkey);
1514         else
1515                 audit_log_format(ab, "(null)");
1516         audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1517         audit_log_end(ab);
1518 }
1519
1520 /**
1521  * audit_receive_filter - apply all rules to the specified message type
1522  * @type: audit message type
1523  * @pid: target pid for netlink audit messages
1524  * @uid: target uid for netlink audit messages
1525  * @seq: netlink audit message sequence (serial) number
1526  * @data: payload data
1527  * @datasz: size of payload data
1528  * @loginuid: loginuid of sender
1529  * @sid: SE Linux Security ID of sender
1530  */
1531 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1532                          size_t datasz, uid_t loginuid, u32 sid)
1533 {
1534         struct task_struct *tsk;
1535         struct audit_netlink_list *dest;
1536         int err = 0;
1537         struct audit_entry *entry;
1538
1539         switch (type) {
1540         case AUDIT_LIST:
1541         case AUDIT_LIST_RULES:
1542                 /* We can't just spew out the rules here because we might fill
1543                  * the available socket buffer space and deadlock waiting for
1544                  * auditctl to read from it... which isn't ever going to
1545                  * happen if we're actually running in the context of auditctl
1546                  * trying to _send_ the stuff */
1547
1548                 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1549                 if (!dest)
1550                         return -ENOMEM;
1551                 dest->pid = pid;
1552                 skb_queue_head_init(&dest->q);
1553
1554                 mutex_lock(&audit_filter_mutex);
1555                 if (type == AUDIT_LIST)
1556                         audit_list(pid, seq, &dest->q);
1557                 else
1558                         audit_list_rules(pid, seq, &dest->q);
1559                 mutex_unlock(&audit_filter_mutex);
1560
1561                 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1562                 if (IS_ERR(tsk)) {
1563                         skb_queue_purge(&dest->q);
1564                         kfree(dest);
1565                         err = PTR_ERR(tsk);
1566                 }
1567                 break;
1568         case AUDIT_ADD:
1569         case AUDIT_ADD_RULE:
1570                 if (type == AUDIT_ADD)
1571                         entry = audit_rule_to_entry(data);
1572                 else
1573                         entry = audit_data_to_entry(data, datasz);
1574                 if (IS_ERR(entry))
1575                         return PTR_ERR(entry);
1576
1577                 err = audit_add_rule(entry,
1578                                      &audit_filter_list[entry->rule.listnr]);
1579                 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1580
1581                 if (err)
1582                         audit_free_rule(entry);
1583                 break;
1584         case AUDIT_DEL:
1585         case AUDIT_DEL_RULE:
1586                 if (type == AUDIT_DEL)
1587                         entry = audit_rule_to_entry(data);
1588                 else
1589                         entry = audit_data_to_entry(data, datasz);
1590                 if (IS_ERR(entry))
1591                         return PTR_ERR(entry);
1592
1593                 err = audit_del_rule(entry,
1594                                      &audit_filter_list[entry->rule.listnr]);
1595                 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1596                                       !err);
1597
1598                 audit_free_rule(entry);
1599                 break;
1600         default:
1601                 return -EINVAL;
1602         }
1603
1604         return err;
1605 }
1606
1607 int audit_comparator(const u32 left, const u32 op, const u32 right)
1608 {
1609         switch (op) {
1610         case AUDIT_EQUAL:
1611                 return (left == right);
1612         case AUDIT_NOT_EQUAL:
1613                 return (left != right);
1614         case AUDIT_LESS_THAN:
1615                 return (left < right);
1616         case AUDIT_LESS_THAN_OR_EQUAL:
1617                 return (left <= right);
1618         case AUDIT_GREATER_THAN:
1619                 return (left > right);
1620         case AUDIT_GREATER_THAN_OR_EQUAL:
1621                 return (left >= right);
1622         case AUDIT_BIT_MASK:
1623                 return (left & right);
1624         case AUDIT_BIT_TEST:
1625                 return ((left & right) == right);
1626         }
1627         BUG();
1628         return 0;
1629 }
1630
1631 /* Compare given dentry name with last component in given path,
1632  * return of 0 indicates a match. */
1633 int audit_compare_dname_path(const char *dname, const char *path,
1634                              int *dirlen)
1635 {
1636         int dlen, plen;
1637         const char *p;
1638
1639         if (!dname || !path)
1640                 return 1;
1641
1642         dlen = strlen(dname);
1643         plen = strlen(path);
1644         if (plen < dlen)
1645                 return 1;
1646
1647         /* disregard trailing slashes */
1648         p = path + plen - 1;
1649         while ((*p == '/') && (p > path))
1650                 p--;
1651
1652         /* find last path component */
1653         p = p - dlen + 1;
1654         if (p < path)
1655                 return 1;
1656         else if (p > path) {
1657                 if (*--p != '/')
1658                         return 1;
1659                 else
1660                         p++;
1661         }
1662
1663         /* return length of path's directory component */
1664         if (dirlen)
1665                 *dirlen = p - path;
1666         return strncmp(p, dname, dlen);
1667 }
1668
1669 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1670                                    struct audit_krule *rule,
1671                                    enum audit_state *state)
1672 {
1673         int i;
1674
1675         for (i = 0; i < rule->field_count; i++) {
1676                 struct audit_field *f = &rule->fields[i];
1677                 int result = 0;
1678
1679                 switch (f->type) {
1680                 case AUDIT_PID:
1681                         result = audit_comparator(cb->creds.pid, f->op, f->val);
1682                         break;
1683                 case AUDIT_UID:
1684                         result = audit_comparator(cb->creds.uid, f->op, f->val);
1685                         break;
1686                 case AUDIT_GID:
1687                         result = audit_comparator(cb->creds.gid, f->op, f->val);
1688                         break;
1689                 case AUDIT_LOGINUID:
1690                         result = audit_comparator(cb->loginuid, f->op, f->val);
1691                         break;
1692                 }
1693
1694                 if (!result)
1695                         return 0;
1696         }
1697         switch (rule->action) {
1698         case AUDIT_NEVER:    *state = AUDIT_DISABLED;       break;
1699         case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
1700         }
1701         return 1;
1702 }
1703
1704 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1705 {
1706         enum audit_state state = AUDIT_DISABLED;
1707         struct audit_entry *e;
1708         int ret = 1;
1709
1710         rcu_read_lock();
1711         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1712                 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1713                         if (state == AUDIT_DISABLED)
1714                                 ret = 0;
1715                         break;
1716                 }
1717         }
1718         rcu_read_unlock();
1719
1720         return ret; /* Audit by default */
1721 }
1722
1723 int audit_filter_type(int type)
1724 {
1725         struct audit_entry *e;
1726         int result = 0;
1727
1728         rcu_read_lock();
1729         if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1730                 goto unlock_and_return;
1731
1732         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1733                                 list) {
1734                 int i;
1735                 for (i = 0; i < e->rule.field_count; i++) {
1736                         struct audit_field *f = &e->rule.fields[i];
1737                         if (f->type == AUDIT_MSGTYPE) {
1738                                 result = audit_comparator(type, f->op, f->val);
1739                                 if (!result)
1740                                         break;
1741                         }
1742                 }
1743                 if (result)
1744                         goto unlock_and_return;
1745         }
1746 unlock_and_return:
1747         rcu_read_unlock();
1748         return result;
1749 }
1750
1751 /* Check to see if the rule contains any selinux fields.  Returns 1 if there
1752    are selinux fields specified in the rule, 0 otherwise. */
1753 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1754 {
1755         int i;
1756
1757         for (i = 0; i < rule->field_count; i++) {
1758                 struct audit_field *f = &rule->fields[i];
1759                 switch (f->type) {
1760                 case AUDIT_SUBJ_USER:
1761                 case AUDIT_SUBJ_ROLE:
1762                 case AUDIT_SUBJ_TYPE:
1763                 case AUDIT_SUBJ_SEN:
1764                 case AUDIT_SUBJ_CLR:
1765                 case AUDIT_OBJ_USER:
1766                 case AUDIT_OBJ_ROLE:
1767                 case AUDIT_OBJ_TYPE:
1768                 case AUDIT_OBJ_LEV_LOW:
1769                 case AUDIT_OBJ_LEV_HIGH:
1770                         return 1;
1771                 }
1772         }
1773
1774         return 0;
1775 }
1776
1777 /* This function will re-initialize the se_rule field of all applicable rules.
1778  * It will traverse the filter lists serarching for rules that contain selinux
1779  * specific filter fields.  When such a rule is found, it is copied, the
1780  * selinux field is re-initialized, and the old rule is replaced with the
1781  * updated rule. */
1782 int selinux_audit_rule_update(void)
1783 {
1784         struct audit_entry *entry, *n, *nentry;
1785         struct audit_watch *watch;
1786         struct audit_tree *tree;
1787         int i, err = 0;
1788
1789         /* audit_filter_mutex synchronizes the writers */
1790         mutex_lock(&audit_filter_mutex);
1791
1792         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1793                 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1794                         if (!audit_rule_has_selinux(&entry->rule))
1795                                 continue;
1796
1797                         watch = entry->rule.watch;
1798                         tree = entry->rule.tree;
1799                         nentry = audit_dupe_rule(&entry->rule, watch);
1800                         if (unlikely(IS_ERR(nentry))) {
1801                                 /* save the first error encountered for the
1802                                  * return value */
1803                                 if (!err)
1804                                         err = PTR_ERR(nentry);
1805                                 audit_panic("error updating selinux filters");
1806                                 if (watch)
1807                                         list_del(&entry->rule.rlist);
1808                                 list_del_rcu(&entry->list);
1809                         } else {
1810                                 if (watch) {
1811                                         list_add(&nentry->rule.rlist,
1812                                                  &watch->rules);
1813                                         list_del(&entry->rule.rlist);
1814                                 } else if (tree)
1815                                         list_replace_init(&entry->rule.rlist,
1816                                                      &nentry->rule.rlist);
1817                                 list_replace_rcu(&entry->list, &nentry->list);
1818                         }
1819                         call_rcu(&entry->rcu, audit_free_rule_rcu);
1820                 }
1821         }
1822
1823         mutex_unlock(&audit_filter_mutex);
1824
1825         return err;
1826 }
1827
1828 /* Update watch data in audit rules based on inotify events. */
1829 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1830                          u32 cookie, const char *dname, struct inode *inode)
1831 {
1832         struct audit_parent *parent;
1833
1834         parent = container_of(i_watch, struct audit_parent, wdata);
1835
1836         if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1837                 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1838                                    inode->i_ino, 0);
1839         else if (mask & (IN_DELETE|IN_MOVED_FROM))
1840                 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1841         /* inotify automatically removes the watch and sends IN_IGNORED */
1842         else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1843                 audit_remove_parent_watches(parent);
1844         /* inotify does not remove the watch, so remove it manually */
1845         else if(mask & IN_MOVE_SELF) {
1846                 audit_remove_parent_watches(parent);
1847                 inotify_remove_watch_locked(audit_ih, i_watch);
1848         } else if (mask & IN_IGNORED)
1849                 put_inotify_watch(i_watch);
1850 }