audit: Add typespecific uid and gid comparators
[linux-3.10.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                 f->uid = INVALID_UID;
346                 f->gid = INVALID_GID;
347
348                 err = -EINVAL;
349                 if (f->op == Audit_bad)
350                         goto exit_free;
351
352                 switch(f->type) {
353                 default:
354                         goto exit_free;
355                 case AUDIT_UID:
356                 case AUDIT_EUID:
357                 case AUDIT_SUID:
358                 case AUDIT_FSUID:
359                 case AUDIT_LOGINUID:
360                         /* bit ops not implemented for uid comparisons */
361                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
362                                 goto exit_free;
363
364                         f->uid = make_kuid(current_user_ns(), f->val);
365                         if (!uid_valid(f->uid))
366                                 goto exit_free;
367                         break;
368                 case AUDIT_GID:
369                 case AUDIT_EGID:
370                 case AUDIT_SGID:
371                 case AUDIT_FSGID:
372                         /* bit ops not implemented for gid comparisons */
373                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
374                                 goto exit_free;
375
376                         f->gid = make_kgid(current_user_ns(), f->val);
377                         if (!gid_valid(f->gid))
378                                 goto exit_free;
379                         break;
380                 case AUDIT_PID:
381                 case AUDIT_PERS:
382                 case AUDIT_MSGTYPE:
383                 case AUDIT_PPID:
384                 case AUDIT_DEVMAJOR:
385                 case AUDIT_DEVMINOR:
386                 case AUDIT_EXIT:
387                 case AUDIT_SUCCESS:
388                         /* bit ops are only useful on syscall args */
389                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
390                                 goto exit_free;
391                         break;
392                 case AUDIT_ARG0:
393                 case AUDIT_ARG1:
394                 case AUDIT_ARG2:
395                 case AUDIT_ARG3:
396                         break;
397                 /* arch is only allowed to be = or != */
398                 case AUDIT_ARCH:
399                         if (f->op != Audit_not_equal && f->op != Audit_equal)
400                                 goto exit_free;
401                         entry->rule.arch_f = f;
402                         break;
403                 case AUDIT_PERM:
404                         if (f->val & ~15)
405                                 goto exit_free;
406                         break;
407                 case AUDIT_FILETYPE:
408                         if (f->val & ~S_IFMT)
409                                 goto exit_free;
410                         break;
411                 case AUDIT_INODE:
412                         err = audit_to_inode(&entry->rule, f);
413                         if (err)
414                                 goto exit_free;
415                         break;
416                 }
417         }
418
419         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
420                 entry->rule.inode_f = NULL;
421
422 exit_nofree:
423         return entry;
424
425 exit_free:
426         audit_free_rule(entry);
427         return ERR_PTR(err);
428 }
429
430 /* Translate struct audit_rule_data to kernel's rule respresentation. */
431 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
432                                                size_t datasz)
433 {
434         int err = 0;
435         struct audit_entry *entry;
436         void *bufp;
437         size_t remain = datasz - sizeof(struct audit_rule_data);
438         int i;
439         char *str;
440
441         entry = audit_to_entry_common((struct audit_rule *)data);
442         if (IS_ERR(entry))
443                 goto exit_nofree;
444
445         bufp = data->buf;
446         entry->rule.vers_ops = 2;
447         for (i = 0; i < data->field_count; i++) {
448                 struct audit_field *f = &entry->rule.fields[i];
449
450                 err = -EINVAL;
451
452                 f->op = audit_to_op(data->fieldflags[i]);
453                 if (f->op == Audit_bad)
454                         goto exit_free;
455
456                 f->type = data->fields[i];
457                 f->val = data->values[i];
458                 f->uid = INVALID_UID;
459                 f->gid = INVALID_GID;
460                 f->lsm_str = NULL;
461                 f->lsm_rule = NULL;
462                 switch(f->type) {
463                 case AUDIT_UID:
464                 case AUDIT_EUID:
465                 case AUDIT_SUID:
466                 case AUDIT_FSUID:
467                 case AUDIT_LOGINUID:
468                 case AUDIT_OBJ_UID:
469                         /* bit ops not implemented for uid comparisons */
470                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
471                                 goto exit_free;
472
473                         f->uid = make_kuid(current_user_ns(), f->val);
474                         if (!uid_valid(f->uid))
475                                 goto exit_free;
476                         break;
477                 case AUDIT_GID:
478                 case AUDIT_EGID:
479                 case AUDIT_SGID:
480                 case AUDIT_FSGID:
481                 case AUDIT_OBJ_GID:
482                         /* bit ops not implemented for gid comparisons */
483                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
484                                 goto exit_free;
485
486                         f->gid = make_kgid(current_user_ns(), f->val);
487                         if (!gid_valid(f->gid))
488                                 goto exit_free;
489                         break;
490                 case AUDIT_PID:
491                 case AUDIT_PERS:
492                 case AUDIT_MSGTYPE:
493                 case AUDIT_PPID:
494                 case AUDIT_DEVMAJOR:
495                 case AUDIT_DEVMINOR:
496                 case AUDIT_EXIT:
497                 case AUDIT_SUCCESS:
498                 case AUDIT_ARG0:
499                 case AUDIT_ARG1:
500                 case AUDIT_ARG2:
501                 case AUDIT_ARG3:
502                         break;
503                 case AUDIT_ARCH:
504                         entry->rule.arch_f = f;
505                         break;
506                 case AUDIT_SUBJ_USER:
507                 case AUDIT_SUBJ_ROLE:
508                 case AUDIT_SUBJ_TYPE:
509                 case AUDIT_SUBJ_SEN:
510                 case AUDIT_SUBJ_CLR:
511                 case AUDIT_OBJ_USER:
512                 case AUDIT_OBJ_ROLE:
513                 case AUDIT_OBJ_TYPE:
514                 case AUDIT_OBJ_LEV_LOW:
515                 case AUDIT_OBJ_LEV_HIGH:
516                         str = audit_unpack_string(&bufp, &remain, f->val);
517                         if (IS_ERR(str))
518                                 goto exit_free;
519                         entry->rule.buflen += f->val;
520
521                         err = security_audit_rule_init(f->type, f->op, str,
522                                                        (void **)&f->lsm_rule);
523                         /* Keep currently invalid fields around in case they
524                          * become valid after a policy reload. */
525                         if (err == -EINVAL) {
526                                 printk(KERN_WARNING "audit rule for LSM "
527                                        "\'%s\' is invalid\n",  str);
528                                 err = 0;
529                         }
530                         if (err) {
531                                 kfree(str);
532                                 goto exit_free;
533                         } else
534                                 f->lsm_str = str;
535                         break;
536                 case AUDIT_WATCH:
537                         str = audit_unpack_string(&bufp, &remain, f->val);
538                         if (IS_ERR(str))
539                                 goto exit_free;
540                         entry->rule.buflen += f->val;
541
542                         err = audit_to_watch(&entry->rule, str, f->val, f->op);
543                         if (err) {
544                                 kfree(str);
545                                 goto exit_free;
546                         }
547                         break;
548                 case AUDIT_DIR:
549                         str = audit_unpack_string(&bufp, &remain, f->val);
550                         if (IS_ERR(str))
551                                 goto exit_free;
552                         entry->rule.buflen += f->val;
553
554                         err = audit_make_tree(&entry->rule, str, f->op);
555                         kfree(str);
556                         if (err)
557                                 goto exit_free;
558                         break;
559                 case AUDIT_INODE:
560                         err = audit_to_inode(&entry->rule, f);
561                         if (err)
562                                 goto exit_free;
563                         break;
564                 case AUDIT_FILTERKEY:
565                         if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
566                                 goto exit_free;
567                         str = audit_unpack_string(&bufp, &remain, f->val);
568                         if (IS_ERR(str))
569                                 goto exit_free;
570                         entry->rule.buflen += f->val;
571                         entry->rule.filterkey = str;
572                         break;
573                 case AUDIT_PERM:
574                         if (f->val & ~15)
575                                 goto exit_free;
576                         break;
577                 case AUDIT_FILETYPE:
578                         if (f->val & ~S_IFMT)
579                                 goto exit_free;
580                         break;
581                 case AUDIT_FIELD_COMPARE:
582                         if (f->val > AUDIT_MAX_FIELD_COMPARE)
583                                 goto exit_free;
584                         break;
585                 default:
586                         goto exit_free;
587                 }
588         }
589
590         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
591                 entry->rule.inode_f = NULL;
592
593 exit_nofree:
594         return entry;
595
596 exit_free:
597         audit_free_rule(entry);
598         return ERR_PTR(err);
599 }
600
601 /* Pack a filter field's string representation into data block. */
602 static inline size_t audit_pack_string(void **bufp, const char *str)
603 {
604         size_t len = strlen(str);
605
606         memcpy(*bufp, str, len);
607         *bufp += len;
608
609         return len;
610 }
611
612 /* Translate kernel rule respresentation to struct audit_rule.
613  * Exists for backward compatibility with userspace. */
614 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
615 {
616         struct audit_rule *rule;
617         int i;
618
619         rule = kzalloc(sizeof(*rule), GFP_KERNEL);
620         if (unlikely(!rule))
621                 return NULL;
622
623         rule->flags = krule->flags | krule->listnr;
624         rule->action = krule->action;
625         rule->field_count = krule->field_count;
626         for (i = 0; i < rule->field_count; i++) {
627                 rule->values[i] = krule->fields[i].val;
628                 rule->fields[i] = krule->fields[i].type;
629
630                 if (krule->vers_ops == 1) {
631                         if (krule->fields[i].op == Audit_not_equal)
632                                 rule->fields[i] |= AUDIT_NEGATE;
633                 } else {
634                         rule->fields[i] |= audit_ops[krule->fields[i].op];
635                 }
636         }
637         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
638
639         return rule;
640 }
641
642 /* Translate kernel rule respresentation to struct audit_rule_data. */
643 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
644 {
645         struct audit_rule_data *data;
646         void *bufp;
647         int i;
648
649         data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
650         if (unlikely(!data))
651                 return NULL;
652         memset(data, 0, sizeof(*data));
653
654         data->flags = krule->flags | krule->listnr;
655         data->action = krule->action;
656         data->field_count = krule->field_count;
657         bufp = data->buf;
658         for (i = 0; i < data->field_count; i++) {
659                 struct audit_field *f = &krule->fields[i];
660
661                 data->fields[i] = f->type;
662                 data->fieldflags[i] = audit_ops[f->op];
663                 switch(f->type) {
664                 case AUDIT_SUBJ_USER:
665                 case AUDIT_SUBJ_ROLE:
666                 case AUDIT_SUBJ_TYPE:
667                 case AUDIT_SUBJ_SEN:
668                 case AUDIT_SUBJ_CLR:
669                 case AUDIT_OBJ_USER:
670                 case AUDIT_OBJ_ROLE:
671                 case AUDIT_OBJ_TYPE:
672                 case AUDIT_OBJ_LEV_LOW:
673                 case AUDIT_OBJ_LEV_HIGH:
674                         data->buflen += data->values[i] =
675                                 audit_pack_string(&bufp, f->lsm_str);
676                         break;
677                 case AUDIT_WATCH:
678                         data->buflen += data->values[i] =
679                                 audit_pack_string(&bufp,
680                                                   audit_watch_path(krule->watch));
681                         break;
682                 case AUDIT_DIR:
683                         data->buflen += data->values[i] =
684                                 audit_pack_string(&bufp,
685                                                   audit_tree_path(krule->tree));
686                         break;
687                 case AUDIT_FILTERKEY:
688                         data->buflen += data->values[i] =
689                                 audit_pack_string(&bufp, krule->filterkey);
690                         break;
691                 default:
692                         data->values[i] = f->val;
693                 }
694         }
695         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
696
697         return data;
698 }
699
700 /* Compare two rules in kernel format.  Considered success if rules
701  * don't match. */
702 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
703 {
704         int i;
705
706         if (a->flags != b->flags ||
707             a->listnr != b->listnr ||
708             a->action != b->action ||
709             a->field_count != b->field_count)
710                 return 1;
711
712         for (i = 0; i < a->field_count; i++) {
713                 if (a->fields[i].type != b->fields[i].type ||
714                     a->fields[i].op != b->fields[i].op)
715                         return 1;
716
717                 switch(a->fields[i].type) {
718                 case AUDIT_SUBJ_USER:
719                 case AUDIT_SUBJ_ROLE:
720                 case AUDIT_SUBJ_TYPE:
721                 case AUDIT_SUBJ_SEN:
722                 case AUDIT_SUBJ_CLR:
723                 case AUDIT_OBJ_USER:
724                 case AUDIT_OBJ_ROLE:
725                 case AUDIT_OBJ_TYPE:
726                 case AUDIT_OBJ_LEV_LOW:
727                 case AUDIT_OBJ_LEV_HIGH:
728                         if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
729                                 return 1;
730                         break;
731                 case AUDIT_WATCH:
732                         if (strcmp(audit_watch_path(a->watch),
733                                    audit_watch_path(b->watch)))
734                                 return 1;
735                         break;
736                 case AUDIT_DIR:
737                         if (strcmp(audit_tree_path(a->tree),
738                                    audit_tree_path(b->tree)))
739                                 return 1;
740                         break;
741                 case AUDIT_FILTERKEY:
742                         /* both filterkeys exist based on above type compare */
743                         if (strcmp(a->filterkey, b->filterkey))
744                                 return 1;
745                         break;
746                 case AUDIT_UID:
747                 case AUDIT_EUID:
748                 case AUDIT_SUID:
749                 case AUDIT_FSUID:
750                 case AUDIT_LOGINUID:
751                 case AUDIT_OBJ_UID:
752                         if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
753                                 return 1;
754                         break;
755                 case AUDIT_GID:
756                 case AUDIT_EGID:
757                 case AUDIT_SGID:
758                 case AUDIT_FSGID:
759                 case AUDIT_OBJ_GID:
760                         if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
761                                 return 1;
762                         break;
763                 default:
764                         if (a->fields[i].val != b->fields[i].val)
765                                 return 1;
766                 }
767         }
768
769         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
770                 if (a->mask[i] != b->mask[i])
771                         return 1;
772
773         return 0;
774 }
775
776 /* Duplicate LSM field information.  The lsm_rule is opaque, so must be
777  * re-initialized. */
778 static inline int audit_dupe_lsm_field(struct audit_field *df,
779                                            struct audit_field *sf)
780 {
781         int ret = 0;
782         char *lsm_str;
783
784         /* our own copy of lsm_str */
785         lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
786         if (unlikely(!lsm_str))
787                 return -ENOMEM;
788         df->lsm_str = lsm_str;
789
790         /* our own (refreshed) copy of lsm_rule */
791         ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
792                                        (void **)&df->lsm_rule);
793         /* Keep currently invalid fields around in case they
794          * become valid after a policy reload. */
795         if (ret == -EINVAL) {
796                 printk(KERN_WARNING "audit rule for LSM \'%s\' is "
797                        "invalid\n", df->lsm_str);
798                 ret = 0;
799         }
800
801         return ret;
802 }
803
804 /* Duplicate an audit rule.  This will be a deep copy with the exception
805  * of the watch - that pointer is carried over.  The LSM specific fields
806  * will be updated in the copy.  The point is to be able to replace the old
807  * rule with the new rule in the filterlist, then free the old rule.
808  * The rlist element is undefined; list manipulations are handled apart from
809  * the initial copy. */
810 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
811 {
812         u32 fcount = old->field_count;
813         struct audit_entry *entry;
814         struct audit_krule *new;
815         char *fk;
816         int i, err = 0;
817
818         entry = audit_init_entry(fcount);
819         if (unlikely(!entry))
820                 return ERR_PTR(-ENOMEM);
821
822         new = &entry->rule;
823         new->vers_ops = old->vers_ops;
824         new->flags = old->flags;
825         new->listnr = old->listnr;
826         new->action = old->action;
827         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
828                 new->mask[i] = old->mask[i];
829         new->prio = old->prio;
830         new->buflen = old->buflen;
831         new->inode_f = old->inode_f;
832         new->field_count = old->field_count;
833
834         /*
835          * note that we are OK with not refcounting here; audit_match_tree()
836          * never dereferences tree and we can't get false positives there
837          * since we'd have to have rule gone from the list *and* removed
838          * before the chunks found by lookup had been allocated, i.e. before
839          * the beginning of list scan.
840          */
841         new->tree = old->tree;
842         memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
843
844         /* deep copy this information, updating the lsm_rule fields, because
845          * the originals will all be freed when the old rule is freed. */
846         for (i = 0; i < fcount; i++) {
847                 switch (new->fields[i].type) {
848                 case AUDIT_SUBJ_USER:
849                 case AUDIT_SUBJ_ROLE:
850                 case AUDIT_SUBJ_TYPE:
851                 case AUDIT_SUBJ_SEN:
852                 case AUDIT_SUBJ_CLR:
853                 case AUDIT_OBJ_USER:
854                 case AUDIT_OBJ_ROLE:
855                 case AUDIT_OBJ_TYPE:
856                 case AUDIT_OBJ_LEV_LOW:
857                 case AUDIT_OBJ_LEV_HIGH:
858                         err = audit_dupe_lsm_field(&new->fields[i],
859                                                        &old->fields[i]);
860                         break;
861                 case AUDIT_FILTERKEY:
862                         fk = kstrdup(old->filterkey, GFP_KERNEL);
863                         if (unlikely(!fk))
864                                 err = -ENOMEM;
865                         else
866                                 new->filterkey = fk;
867                 }
868                 if (err) {
869                         audit_free_rule(entry);
870                         return ERR_PTR(err);
871                 }
872         }
873
874         if (old->watch) {
875                 audit_get_watch(old->watch);
876                 new->watch = old->watch;
877         }
878
879         return entry;
880 }
881
882 /* Find an existing audit rule.
883  * Caller must hold audit_filter_mutex to prevent stale rule data. */
884 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
885                                            struct list_head **p)
886 {
887         struct audit_entry *e, *found = NULL;
888         struct list_head *list;
889         int h;
890
891         if (entry->rule.inode_f) {
892                 h = audit_hash_ino(entry->rule.inode_f->val);
893                 *p = list = &audit_inode_hash[h];
894         } else if (entry->rule.watch) {
895                 /* we don't know the inode number, so must walk entire hash */
896                 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
897                         list = &audit_inode_hash[h];
898                         list_for_each_entry(e, list, list)
899                                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
900                                         found = e;
901                                         goto out;
902                                 }
903                 }
904                 goto out;
905         } else {
906                 *p = list = &audit_filter_list[entry->rule.listnr];
907         }
908
909         list_for_each_entry(e, list, list)
910                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
911                         found = e;
912                         goto out;
913                 }
914
915 out:
916         return found;
917 }
918
919 static u64 prio_low = ~0ULL/2;
920 static u64 prio_high = ~0ULL/2 - 1;
921
922 /* Add rule to given filterlist if not a duplicate. */
923 static inline int audit_add_rule(struct audit_entry *entry)
924 {
925         struct audit_entry *e;
926         struct audit_watch *watch = entry->rule.watch;
927         struct audit_tree *tree = entry->rule.tree;
928         struct list_head *list;
929         int err;
930 #ifdef CONFIG_AUDITSYSCALL
931         int dont_count = 0;
932
933         /* If either of these, don't count towards total */
934         if (entry->rule.listnr == AUDIT_FILTER_USER ||
935                 entry->rule.listnr == AUDIT_FILTER_TYPE)
936                 dont_count = 1;
937 #endif
938
939         mutex_lock(&audit_filter_mutex);
940         e = audit_find_rule(entry, &list);
941         if (e) {
942                 mutex_unlock(&audit_filter_mutex);
943                 err = -EEXIST;
944                 /* normally audit_add_tree_rule() will free it on failure */
945                 if (tree)
946                         audit_put_tree(tree);
947                 goto error;
948         }
949
950         if (watch) {
951                 /* audit_filter_mutex is dropped and re-taken during this call */
952                 err = audit_add_watch(&entry->rule, &list);
953                 if (err) {
954                         mutex_unlock(&audit_filter_mutex);
955                         goto error;
956                 }
957         }
958         if (tree) {
959                 err = audit_add_tree_rule(&entry->rule);
960                 if (err) {
961                         mutex_unlock(&audit_filter_mutex);
962                         goto error;
963                 }
964         }
965
966         entry->rule.prio = ~0ULL;
967         if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
968                 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
969                         entry->rule.prio = ++prio_high;
970                 else
971                         entry->rule.prio = --prio_low;
972         }
973
974         if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
975                 list_add(&entry->rule.list,
976                          &audit_rules_list[entry->rule.listnr]);
977                 list_add_rcu(&entry->list, list);
978                 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
979         } else {
980                 list_add_tail(&entry->rule.list,
981                               &audit_rules_list[entry->rule.listnr]);
982                 list_add_tail_rcu(&entry->list, list);
983         }
984 #ifdef CONFIG_AUDITSYSCALL
985         if (!dont_count)
986                 audit_n_rules++;
987
988         if (!audit_match_signal(entry))
989                 audit_signals++;
990 #endif
991         mutex_unlock(&audit_filter_mutex);
992
993         return 0;
994
995 error:
996         if (watch)
997                 audit_put_watch(watch); /* tmp watch, matches initial get */
998         return err;
999 }
1000
1001 /* Remove an existing rule from filterlist. */
1002 static inline int audit_del_rule(struct audit_entry *entry)
1003 {
1004         struct audit_entry  *e;
1005         struct audit_watch *watch = entry->rule.watch;
1006         struct audit_tree *tree = entry->rule.tree;
1007         struct list_head *list;
1008         int ret = 0;
1009 #ifdef CONFIG_AUDITSYSCALL
1010         int dont_count = 0;
1011
1012         /* If either of these, don't count towards total */
1013         if (entry->rule.listnr == AUDIT_FILTER_USER ||
1014                 entry->rule.listnr == AUDIT_FILTER_TYPE)
1015                 dont_count = 1;
1016 #endif
1017
1018         mutex_lock(&audit_filter_mutex);
1019         e = audit_find_rule(entry, &list);
1020         if (!e) {
1021                 mutex_unlock(&audit_filter_mutex);
1022                 ret = -ENOENT;
1023                 goto out;
1024         }
1025
1026         if (e->rule.watch)
1027                 audit_remove_watch_rule(&e->rule);
1028
1029         if (e->rule.tree)
1030                 audit_remove_tree_rule(&e->rule);
1031
1032         list_del_rcu(&e->list);
1033         list_del(&e->rule.list);
1034         call_rcu(&e->rcu, audit_free_rule_rcu);
1035
1036 #ifdef CONFIG_AUDITSYSCALL
1037         if (!dont_count)
1038                 audit_n_rules--;
1039
1040         if (!audit_match_signal(entry))
1041                 audit_signals--;
1042 #endif
1043         mutex_unlock(&audit_filter_mutex);
1044
1045 out:
1046         if (watch)
1047                 audit_put_watch(watch); /* match initial get */
1048         if (tree)
1049                 audit_put_tree(tree);   /* that's the temporary one */
1050
1051         return ret;
1052 }
1053
1054 /* List rules using struct audit_rule.  Exists for backward
1055  * compatibility with userspace. */
1056 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1057 {
1058         struct sk_buff *skb;
1059         struct audit_krule *r;
1060         int i;
1061
1062         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1063          * iterator to sync with list writers. */
1064         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1065                 list_for_each_entry(r, &audit_rules_list[i], list) {
1066                         struct audit_rule *rule;
1067
1068                         rule = audit_krule_to_rule(r);
1069                         if (unlikely(!rule))
1070                                 break;
1071                         skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1072                                          rule, sizeof(*rule));
1073                         if (skb)
1074                                 skb_queue_tail(q, skb);
1075                         kfree(rule);
1076                 }
1077         }
1078         skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1079         if (skb)
1080                 skb_queue_tail(q, skb);
1081 }
1082
1083 /* List rules using struct audit_rule_data. */
1084 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1085 {
1086         struct sk_buff *skb;
1087         struct audit_krule *r;
1088         int i;
1089
1090         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1091          * iterator to sync with list writers. */
1092         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1093                 list_for_each_entry(r, &audit_rules_list[i], list) {
1094                         struct audit_rule_data *data;
1095
1096                         data = audit_krule_to_data(r);
1097                         if (unlikely(!data))
1098                                 break;
1099                         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1100                                          data, sizeof(*data) + data->buflen);
1101                         if (skb)
1102                                 skb_queue_tail(q, skb);
1103                         kfree(data);
1104                 }
1105         }
1106         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1107         if (skb)
1108                 skb_queue_tail(q, skb);
1109 }
1110
1111 /* Log rule additions and removals */
1112 static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid,
1113                                   char *action, struct audit_krule *rule,
1114                                   int res)
1115 {
1116         struct audit_buffer *ab;
1117
1118         if (!audit_enabled)
1119                 return;
1120
1121         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1122         if (!ab)
1123                 return;
1124         audit_log_format(ab, "auid=%u ses=%u", loginuid, sessionid);
1125         if (sid) {
1126                 char *ctx = NULL;
1127                 u32 len;
1128                 if (security_secid_to_secctx(sid, &ctx, &len))
1129                         audit_log_format(ab, " ssid=%u", sid);
1130                 else {
1131                         audit_log_format(ab, " subj=%s", ctx);
1132                         security_release_secctx(ctx, len);
1133                 }
1134         }
1135         audit_log_format(ab, " op=");
1136         audit_log_string(ab, action);
1137         audit_log_key(ab, rule->filterkey);
1138         audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1139         audit_log_end(ab);
1140 }
1141
1142 /**
1143  * audit_receive_filter - apply all rules to the specified message type
1144  * @type: audit message type
1145  * @pid: target pid for netlink audit messages
1146  * @uid: target uid for netlink audit messages
1147  * @seq: netlink audit message sequence (serial) number
1148  * @data: payload data
1149  * @datasz: size of payload data
1150  * @loginuid: loginuid of sender
1151  * @sessionid: sessionid for netlink audit message
1152  * @sid: SE Linux Security ID of sender
1153  */
1154 int audit_receive_filter(int type, int pid, int seq, void *data,
1155                          size_t datasz, uid_t loginuid, u32 sessionid, u32 sid)
1156 {
1157         struct task_struct *tsk;
1158         struct audit_netlink_list *dest;
1159         int err = 0;
1160         struct audit_entry *entry;
1161
1162         switch (type) {
1163         case AUDIT_LIST:
1164         case AUDIT_LIST_RULES:
1165                 /* We can't just spew out the rules here because we might fill
1166                  * the available socket buffer space and deadlock waiting for
1167                  * auditctl to read from it... which isn't ever going to
1168                  * happen if we're actually running in the context of auditctl
1169                  * trying to _send_ the stuff */
1170
1171                 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1172                 if (!dest)
1173                         return -ENOMEM;
1174                 dest->pid = pid;
1175                 skb_queue_head_init(&dest->q);
1176
1177                 mutex_lock(&audit_filter_mutex);
1178                 if (type == AUDIT_LIST)
1179                         audit_list(pid, seq, &dest->q);
1180                 else
1181                         audit_list_rules(pid, seq, &dest->q);
1182                 mutex_unlock(&audit_filter_mutex);
1183
1184                 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1185                 if (IS_ERR(tsk)) {
1186                         skb_queue_purge(&dest->q);
1187                         kfree(dest);
1188                         err = PTR_ERR(tsk);
1189                 }
1190                 break;
1191         case AUDIT_ADD:
1192         case AUDIT_ADD_RULE:
1193                 if (type == AUDIT_ADD)
1194                         entry = audit_rule_to_entry(data);
1195                 else
1196                         entry = audit_data_to_entry(data, datasz);
1197                 if (IS_ERR(entry))
1198                         return PTR_ERR(entry);
1199
1200                 err = audit_add_rule(entry);
1201                 audit_log_rule_change(loginuid, sessionid, sid, "add rule",
1202                                       &entry->rule, !err);
1203
1204                 if (err)
1205                         audit_free_rule(entry);
1206                 break;
1207         case AUDIT_DEL:
1208         case AUDIT_DEL_RULE:
1209                 if (type == AUDIT_DEL)
1210                         entry = audit_rule_to_entry(data);
1211                 else
1212                         entry = audit_data_to_entry(data, datasz);
1213                 if (IS_ERR(entry))
1214                         return PTR_ERR(entry);
1215
1216                 err = audit_del_rule(entry);
1217                 audit_log_rule_change(loginuid, sessionid, sid, "remove rule",
1218                                       &entry->rule, !err);
1219
1220                 audit_free_rule(entry);
1221                 break;
1222         default:
1223                 return -EINVAL;
1224         }
1225
1226         return err;
1227 }
1228
1229 int audit_comparator(u32 left, u32 op, u32 right)
1230 {
1231         switch (op) {
1232         case Audit_equal:
1233                 return (left == right);
1234         case Audit_not_equal:
1235                 return (left != right);
1236         case Audit_lt:
1237                 return (left < right);
1238         case Audit_le:
1239                 return (left <= right);
1240         case Audit_gt:
1241                 return (left > right);
1242         case Audit_ge:
1243                 return (left >= right);
1244         case Audit_bitmask:
1245                 return (left & right);
1246         case Audit_bittest:
1247                 return ((left & right) == right);
1248         default:
1249                 BUG();
1250                 return 0;
1251         }
1252 }
1253
1254 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1255 {
1256         switch (op) {
1257         case Audit_equal:
1258                 return uid_eq(left, right);
1259         case Audit_not_equal:
1260                 return !uid_eq(left, right);
1261         case Audit_lt:
1262                 return uid_lt(left, right);
1263         case Audit_le:
1264                 return uid_lte(left, right);
1265         case Audit_gt:
1266                 return uid_gt(left, right);
1267         case Audit_ge:
1268                 return uid_gte(left, right);
1269         case Audit_bitmask:
1270         case Audit_bittest:
1271         default:
1272                 BUG();
1273                 return 0;
1274         }
1275 }
1276
1277 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1278 {
1279         switch (op) {
1280         case Audit_equal:
1281                 return gid_eq(left, right);
1282         case Audit_not_equal:
1283                 return !gid_eq(left, right);
1284         case Audit_lt:
1285                 return gid_lt(left, right);
1286         case Audit_le:
1287                 return gid_lte(left, right);
1288         case Audit_gt:
1289                 return gid_gt(left, right);
1290         case Audit_ge:
1291                 return gid_gte(left, right);
1292         case Audit_bitmask:
1293         case Audit_bittest:
1294         default:
1295                 BUG();
1296                 return 0;
1297         }
1298 }
1299
1300 /* Compare given dentry name with last component in given path,
1301  * return of 0 indicates a match. */
1302 int audit_compare_dname_path(const char *dname, const char *path,
1303                              int *dirlen)
1304 {
1305         int dlen, plen;
1306         const char *p;
1307
1308         if (!dname || !path)
1309                 return 1;
1310
1311         dlen = strlen(dname);
1312         plen = strlen(path);
1313         if (plen < dlen)
1314                 return 1;
1315
1316         /* disregard trailing slashes */
1317         p = path + plen - 1;
1318         while ((*p == '/') && (p > path))
1319                 p--;
1320
1321         /* find last path component */
1322         p = p - dlen + 1;
1323         if (p < path)
1324                 return 1;
1325         else if (p > path) {
1326                 if (*--p != '/')
1327                         return 1;
1328                 else
1329                         p++;
1330         }
1331
1332         /* return length of path's directory component */
1333         if (dirlen)
1334                 *dirlen = p - path;
1335         return strncmp(p, dname, dlen);
1336 }
1337
1338 static int audit_filter_user_rules(struct audit_krule *rule,
1339                                    enum audit_state *state)
1340 {
1341         int i;
1342
1343         for (i = 0; i < rule->field_count; i++) {
1344                 struct audit_field *f = &rule->fields[i];
1345                 int result = 0;
1346                 u32 sid;
1347
1348                 switch (f->type) {
1349                 case AUDIT_PID:
1350                         result = audit_comparator(task_pid_vnr(current), f->op, f->val);
1351                         break;
1352                 case AUDIT_UID:
1353                         result = audit_uid_comparator(current_uid(), f->op, f->uid);
1354                         break;
1355                 case AUDIT_GID:
1356                         result = audit_gid_comparator(current_gid(), f->op, f->gid);
1357                         break;
1358                 case AUDIT_LOGINUID:
1359                         result = audit_uid_comparator(audit_get_loginuid(current),
1360                                                   f->op, f->uid);
1361                         break;
1362                 case AUDIT_SUBJ_USER:
1363                 case AUDIT_SUBJ_ROLE:
1364                 case AUDIT_SUBJ_TYPE:
1365                 case AUDIT_SUBJ_SEN:
1366                 case AUDIT_SUBJ_CLR:
1367                         if (f->lsm_rule) {
1368                                 security_task_getsecid(current, &sid);
1369                                 result = security_audit_rule_match(sid,
1370                                                                    f->type,
1371                                                                    f->op,
1372                                                                    f->lsm_rule,
1373                                                                    NULL);
1374                         }
1375                         break;
1376                 }
1377
1378                 if (!result)
1379                         return 0;
1380         }
1381         switch (rule->action) {
1382         case AUDIT_NEVER:    *state = AUDIT_DISABLED;       break;
1383         case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
1384         }
1385         return 1;
1386 }
1387
1388 int audit_filter_user(void)
1389 {
1390         enum audit_state state = AUDIT_DISABLED;
1391         struct audit_entry *e;
1392         int ret = 1;
1393
1394         rcu_read_lock();
1395         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1396                 if (audit_filter_user_rules(&e->rule, &state)) {
1397                         if (state == AUDIT_DISABLED)
1398                                 ret = 0;
1399                         break;
1400                 }
1401         }
1402         rcu_read_unlock();
1403
1404         return ret; /* Audit by default */
1405 }
1406
1407 int audit_filter_type(int type)
1408 {
1409         struct audit_entry *e;
1410         int result = 0;
1411
1412         rcu_read_lock();
1413         if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1414                 goto unlock_and_return;
1415
1416         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1417                                 list) {
1418                 int i;
1419                 for (i = 0; i < e->rule.field_count; i++) {
1420                         struct audit_field *f = &e->rule.fields[i];
1421                         if (f->type == AUDIT_MSGTYPE) {
1422                                 result = audit_comparator(type, f->op, f->val);
1423                                 if (!result)
1424                                         break;
1425                         }
1426                 }
1427                 if (result)
1428                         goto unlock_and_return;
1429         }
1430 unlock_and_return:
1431         rcu_read_unlock();
1432         return result;
1433 }
1434
1435 static int update_lsm_rule(struct audit_krule *r)
1436 {
1437         struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1438         struct audit_entry *nentry;
1439         int err = 0;
1440
1441         if (!security_audit_rule_known(r))
1442                 return 0;
1443
1444         nentry = audit_dupe_rule(r);
1445         if (IS_ERR(nentry)) {
1446                 /* save the first error encountered for the
1447                  * return value */
1448                 err = PTR_ERR(nentry);
1449                 audit_panic("error updating LSM filters");
1450                 if (r->watch)
1451                         list_del(&r->rlist);
1452                 list_del_rcu(&entry->list);
1453                 list_del(&r->list);
1454         } else {
1455                 if (r->watch || r->tree)
1456                         list_replace_init(&r->rlist, &nentry->rule.rlist);
1457                 list_replace_rcu(&entry->list, &nentry->list);
1458                 list_replace(&r->list, &nentry->rule.list);
1459         }
1460         call_rcu(&entry->rcu, audit_free_rule_rcu);
1461
1462         return err;
1463 }
1464
1465 /* This function will re-initialize the lsm_rule field of all applicable rules.
1466  * It will traverse the filter lists serarching for rules that contain LSM
1467  * specific filter fields.  When such a rule is found, it is copied, the
1468  * LSM field is re-initialized, and the old rule is replaced with the
1469  * updated rule. */
1470 int audit_update_lsm_rules(void)
1471 {
1472         struct audit_krule *r, *n;
1473         int i, err = 0;
1474
1475         /* audit_filter_mutex synchronizes the writers */
1476         mutex_lock(&audit_filter_mutex);
1477
1478         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1479                 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1480                         int res = update_lsm_rule(r);
1481                         if (!err)
1482                                 err = res;
1483                 }
1484         }
1485         mutex_unlock(&audit_filter_mutex);
1486
1487         return err;
1488 }