1 /* auditfilter.c -- filtering of audit events
3 * Copyright 2003-2004 Red Hat, Inc.
4 * Copyright 2005 Hewlett-Packard Development Company, L.P.
5 * Copyright 2005 IBM Corporation
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.
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.
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
22 #include <linux/kernel.h>
23 #include <linux/audit.h>
24 #include <linux/kthread.h>
25 #include <linux/mutex.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>
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.
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.
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.
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 */
67 * audit_parent status flags:
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.
75 #define AUDIT_PARENT_INVALID 0x001
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
90 static DEFINE_MUTEX(audit_filter_mutex
);
93 extern struct inotify_handle
*audit_ih
;
95 /* Inotify events we care about. */
96 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
98 void audit_free_parent(struct inotify_watch
*i_watch
)
100 struct audit_parent
*parent
;
102 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
103 WARN_ON(!list_empty(&parent
->watches
));
107 static inline void audit_get_watch(struct audit_watch
*watch
)
109 atomic_inc(&watch
->count
);
112 static void audit_put_watch(struct audit_watch
*watch
)
114 if (atomic_dec_and_test(&watch
->count
)) {
115 WARN_ON(watch
->parent
);
116 WARN_ON(!list_empty(&watch
->rules
));
122 static void audit_remove_watch(struct audit_watch
*watch
)
124 list_del(&watch
->wlist
);
125 put_inotify_watch(&watch
->parent
->wdata
);
126 watch
->parent
= NULL
;
127 audit_put_watch(watch
); /* match initial get */
130 static inline void audit_free_rule(struct audit_entry
*e
)
134 /* some rules don't have associated watches */
136 audit_put_watch(e
->rule
.watch
);
138 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
139 struct audit_field
*f
= &e
->rule
.fields
[i
];
141 selinux_audit_rule_free(f
->se_rule
);
143 kfree(e
->rule
.fields
);
144 kfree(e
->rule
.filterkey
);
148 static inline void audit_free_rule_rcu(struct rcu_head
*head
)
150 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
154 /* Initialize a parent watch entry. */
155 static struct audit_parent
*audit_init_parent(struct nameidata
*ndp
)
157 struct audit_parent
*parent
;
160 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
161 if (unlikely(!parent
))
162 return ERR_PTR(-ENOMEM
);
164 INIT_LIST_HEAD(&parent
->watches
);
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
,
173 audit_free_parent(&parent
->wdata
);
180 /* Initialize a watch entry. */
181 static struct audit_watch
*audit_init_watch(char *path
)
183 struct audit_watch
*watch
;
185 watch
= kzalloc(sizeof(*watch
), GFP_KERNEL
);
186 if (unlikely(!watch
))
187 return ERR_PTR(-ENOMEM
);
189 INIT_LIST_HEAD(&watch
->rules
);
190 atomic_set(&watch
->count
, 1);
192 watch
->dev
= (dev_t
)-1;
193 watch
->ino
= (unsigned long)-1;
198 /* Initialize an audit filterlist entry. */
199 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
201 struct audit_entry
*entry
;
202 struct audit_field
*fields
;
204 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
205 if (unlikely(!entry
))
208 fields
= kzalloc(sizeof(*fields
) * field_count
, GFP_KERNEL
);
209 if (unlikely(!fields
)) {
213 entry
->rule
.fields
= fields
;
218 /* Unpack a filter field's string representation from user-space
220 static char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
224 if (!*bufp
|| (len
== 0) || (len
> *remain
))
225 return ERR_PTR(-EINVAL
);
227 /* Of the currently implemented string fields, PATH_MAX
228 * defines the longest valid length.
231 return ERR_PTR(-ENAMETOOLONG
);
233 str
= kmalloc(len
+ 1, GFP_KERNEL
);
235 return ERR_PTR(-ENOMEM
);
237 memcpy(str
, *bufp
, len
);
245 /* Translate an inode field to kernel respresentation. */
246 static inline int audit_to_inode(struct audit_krule
*krule
,
247 struct audit_field
*f
)
249 if (krule
->listnr
!= AUDIT_FILTER_EXIT
||
250 krule
->watch
|| krule
->inode_f
)
257 /* Translate a watch string to kernel respresentation. */
258 static int audit_to_watch(struct audit_krule
*krule
, char *path
, int len
,
261 struct audit_watch
*watch
;
266 if (path
[0] != '/' || path
[len
-1] == '/' ||
267 krule
->listnr
!= AUDIT_FILTER_EXIT
||
269 krule
->inode_f
|| krule
->watch
) /* 1 inode # per rule, for hash */
272 watch
= audit_init_watch(path
);
273 if (unlikely(IS_ERR(watch
)))
274 return PTR_ERR(watch
);
276 audit_get_watch(watch
);
277 krule
->watch
= watch
;
282 static __u32
*classes
[AUDIT_SYSCALL_CLASSES
];
284 int __init
audit_register_class(int class, unsigned *list
)
286 __u32
*p
= kzalloc(AUDIT_BITMASK_SIZE
* sizeof(__u32
), GFP_KERNEL
);
289 while (*list
!= ~0U) {
290 unsigned n
= *list
++;
291 if (n
>= AUDIT_BITMASK_SIZE
* 32 - AUDIT_SYSCALL_CLASSES
) {
295 p
[AUDIT_WORD(n
)] |= AUDIT_BIT(n
);
297 if (class >= AUDIT_SYSCALL_CLASSES
|| classes
[class]) {
305 /* Common user-space to kernel rule translation. */
306 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule
*rule
)
309 struct audit_entry
*entry
;
313 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
317 case AUDIT_FILTER_USER
:
318 case AUDIT_FILTER_TYPE
:
319 #ifdef CONFIG_AUDITSYSCALL
320 case AUDIT_FILTER_ENTRY
:
321 case AUDIT_FILTER_EXIT
:
322 case AUDIT_FILTER_TASK
:
326 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
327 printk(KERN_ERR
"AUDIT_POSSIBLE is deprecated\n");
330 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
332 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
336 entry
= audit_init_entry(rule
->field_count
);
340 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
341 entry
->rule
.listnr
= listnr
;
342 entry
->rule
.action
= rule
->action
;
343 entry
->rule
.field_count
= rule
->field_count
;
345 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
346 entry
->rule
.mask
[i
] = rule
->mask
[i
];
348 for (i
= 0; i
< AUDIT_SYSCALL_CLASSES
; i
++) {
349 int bit
= AUDIT_BITMASK_SIZE
* 32 - i
- 1;
350 __u32
*p
= &entry
->rule
.mask
[AUDIT_WORD(bit
)];
353 if (!(*p
& AUDIT_BIT(bit
)))
355 *p
&= ~AUDIT_BIT(bit
);
359 for (j
= 0; j
< AUDIT_BITMASK_SIZE
; j
++)
360 entry
->rule
.mask
[j
] |= class[j
];
370 /* Translate struct audit_rule to kernel's rule respresentation.
371 * Exists for backward compatibility with userspace. */
372 static struct audit_entry
*audit_rule_to_entry(struct audit_rule
*rule
)
374 struct audit_entry
*entry
;
375 struct audit_field
*f
;
379 entry
= audit_to_entry_common(rule
);
383 for (i
= 0; i
< rule
->field_count
; i
++) {
384 struct audit_field
*f
= &entry
->rule
.fields
[i
];
386 f
->op
= rule
->fields
[i
] & (AUDIT_NEGATE
|AUDIT_OPERATORS
);
387 f
->type
= rule
->fields
[i
] & ~(AUDIT_NEGATE
|AUDIT_OPERATORS
);
388 f
->val
= rule
->values
[i
];
417 err
= audit_to_inode(&entry
->rule
, f
);
423 entry
->rule
.vers_ops
= (f
->op
& AUDIT_OPERATORS
) ? 2 : 1;
425 /* Support for legacy operators where
426 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
427 if (f
->op
& AUDIT_NEGATE
)
428 f
->op
= AUDIT_NOT_EQUAL
;
431 else if (f
->op
== AUDIT_OPERATORS
) {
437 f
= entry
->rule
.inode_f
;
440 case AUDIT_NOT_EQUAL
:
441 entry
->rule
.inode_f
= NULL
;
454 audit_free_rule(entry
);
458 /* Translate struct audit_rule_data to kernel's rule respresentation. */
459 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
463 struct audit_entry
*entry
;
464 struct audit_field
*f
;
466 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
470 entry
= audit_to_entry_common((struct audit_rule
*)data
);
475 entry
->rule
.vers_ops
= 2;
476 for (i
= 0; i
< data
->field_count
; i
++) {
477 struct audit_field
*f
= &entry
->rule
.fields
[i
];
480 if (!(data
->fieldflags
[i
] & AUDIT_OPERATORS
) ||
481 data
->fieldflags
[i
] & ~AUDIT_OPERATORS
)
484 f
->op
= data
->fieldflags
[i
] & AUDIT_OPERATORS
;
485 f
->type
= data
->fields
[i
];
486 f
->val
= data
->values
[i
];
513 case AUDIT_SUBJ_USER
:
514 case AUDIT_SUBJ_ROLE
:
515 case AUDIT_SUBJ_TYPE
:
521 case AUDIT_OBJ_LEV_LOW
:
522 case AUDIT_OBJ_LEV_HIGH
:
523 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
526 entry
->rule
.buflen
+= f
->val
;
528 err
= selinux_audit_rule_init(f
->type
, f
->op
, str
,
530 /* Keep currently invalid fields around in case they
531 * become valid after a policy reload. */
532 if (err
== -EINVAL
) {
533 printk(KERN_WARNING
"audit rule for selinux "
534 "\'%s\' is invalid\n", str
);
544 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
547 entry
->rule
.buflen
+= f
->val
;
549 err
= audit_to_watch(&entry
->rule
, str
, f
->val
, f
->op
);
556 err
= audit_to_inode(&entry
->rule
, f
);
560 case AUDIT_FILTERKEY
:
562 if (entry
->rule
.filterkey
|| f
->val
> AUDIT_MAX_KEY_LEN
)
564 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
567 entry
->rule
.buflen
+= f
->val
;
568 entry
->rule
.filterkey
= str
;
575 f
= entry
->rule
.inode_f
;
578 case AUDIT_NOT_EQUAL
:
579 entry
->rule
.inode_f
= NULL
;
592 audit_free_rule(entry
);
596 /* Pack a filter field's string representation into data block. */
597 static inline size_t audit_pack_string(void **bufp
, char *str
)
599 size_t len
= strlen(str
);
601 memcpy(*bufp
, str
, len
);
607 /* Translate kernel rule respresentation to struct audit_rule.
608 * Exists for backward compatibility with userspace. */
609 static struct audit_rule
*audit_krule_to_rule(struct audit_krule
*krule
)
611 struct audit_rule
*rule
;
614 rule
= kmalloc(sizeof(*rule
), GFP_KERNEL
);
617 memset(rule
, 0, sizeof(*rule
));
619 rule
->flags
= krule
->flags
| krule
->listnr
;
620 rule
->action
= krule
->action
;
621 rule
->field_count
= krule
->field_count
;
622 for (i
= 0; i
< rule
->field_count
; i
++) {
623 rule
->values
[i
] = krule
->fields
[i
].val
;
624 rule
->fields
[i
] = krule
->fields
[i
].type
;
626 if (krule
->vers_ops
== 1) {
627 if (krule
->fields
[i
].op
& AUDIT_NOT_EQUAL
)
628 rule
->fields
[i
] |= AUDIT_NEGATE
;
630 rule
->fields
[i
] |= krule
->fields
[i
].op
;
633 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) rule
->mask
[i
] = krule
->mask
[i
];
638 /* Translate kernel rule respresentation to struct audit_rule_data. */
639 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
641 struct audit_rule_data
*data
;
645 data
= kmalloc(sizeof(*data
) + krule
->buflen
, GFP_KERNEL
);
648 memset(data
, 0, sizeof(*data
));
650 data
->flags
= krule
->flags
| krule
->listnr
;
651 data
->action
= krule
->action
;
652 data
->field_count
= krule
->field_count
;
654 for (i
= 0; i
< data
->field_count
; i
++) {
655 struct audit_field
*f
= &krule
->fields
[i
];
657 data
->fields
[i
] = f
->type
;
658 data
->fieldflags
[i
] = f
->op
;
660 case AUDIT_SUBJ_USER
:
661 case AUDIT_SUBJ_ROLE
:
662 case AUDIT_SUBJ_TYPE
:
668 case AUDIT_OBJ_LEV_LOW
:
669 case AUDIT_OBJ_LEV_HIGH
:
670 data
->buflen
+= data
->values
[i
] =
671 audit_pack_string(&bufp
, f
->se_str
);
674 data
->buflen
+= data
->values
[i
] =
675 audit_pack_string(&bufp
, krule
->watch
->path
);
677 case AUDIT_FILTERKEY
:
678 data
->buflen
+= data
->values
[i
] =
679 audit_pack_string(&bufp
, krule
->filterkey
);
682 data
->values
[i
] = f
->val
;
685 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
690 /* Compare two rules in kernel format. Considered success if rules
692 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
696 if (a
->flags
!= b
->flags
||
697 a
->listnr
!= b
->listnr
||
698 a
->action
!= b
->action
||
699 a
->field_count
!= b
->field_count
)
702 for (i
= 0; i
< a
->field_count
; i
++) {
703 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
704 a
->fields
[i
].op
!= b
->fields
[i
].op
)
707 switch(a
->fields
[i
].type
) {
708 case AUDIT_SUBJ_USER
:
709 case AUDIT_SUBJ_ROLE
:
710 case AUDIT_SUBJ_TYPE
:
716 case AUDIT_OBJ_LEV_LOW
:
717 case AUDIT_OBJ_LEV_HIGH
:
718 if (strcmp(a
->fields
[i
].se_str
, b
->fields
[i
].se_str
))
722 if (strcmp(a
->watch
->path
, b
->watch
->path
))
725 case AUDIT_FILTERKEY
:
726 /* both filterkeys exist based on above type compare */
727 if (strcmp(a
->filterkey
, b
->filterkey
))
731 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
736 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
737 if (a
->mask
[i
] != b
->mask
[i
])
743 /* Duplicate the given audit watch. The new watch's rules list is initialized
744 * to an empty list and wlist is undefined. */
745 static struct audit_watch
*audit_dupe_watch(struct audit_watch
*old
)
748 struct audit_watch
*new;
750 path
= kstrdup(old
->path
, GFP_KERNEL
);
752 return ERR_PTR(-ENOMEM
);
754 new = audit_init_watch(path
);
755 if (unlikely(IS_ERR(new))) {
762 get_inotify_watch(&old
->parent
->wdata
);
763 new->parent
= old
->parent
;
769 /* Duplicate selinux field information. The se_rule is opaque, so must be
771 static inline int audit_dupe_selinux_field(struct audit_field
*df
,
772 struct audit_field
*sf
)
777 /* our own copy of se_str */
778 se_str
= kstrdup(sf
->se_str
, GFP_KERNEL
);
779 if (unlikely(IS_ERR(se_str
)))
783 /* our own (refreshed) copy of se_rule */
784 ret
= selinux_audit_rule_init(df
->type
, df
->op
, df
->se_str
,
786 /* Keep currently invalid fields around in case they
787 * become valid after a policy reload. */
788 if (ret
== -EINVAL
) {
789 printk(KERN_WARNING
"audit rule for selinux \'%s\' is "
790 "invalid\n", df
->se_str
);
797 /* Duplicate an audit rule. This will be a deep copy with the exception
798 * of the watch - that pointer is carried over. The selinux specific fields
799 * will be updated in the copy. The point is to be able to replace the old
800 * rule with the new rule in the filterlist, then free the old rule.
801 * The rlist element is undefined; list manipulations are handled apart from
802 * the initial copy. */
803 static struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
,
804 struct audit_watch
*watch
)
806 u32 fcount
= old
->field_count
;
807 struct audit_entry
*entry
;
808 struct audit_krule
*new;
812 entry
= audit_init_entry(fcount
);
813 if (unlikely(!entry
))
814 return ERR_PTR(-ENOMEM
);
817 new->vers_ops
= old
->vers_ops
;
818 new->flags
= old
->flags
;
819 new->listnr
= old
->listnr
;
820 new->action
= old
->action
;
821 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
822 new->mask
[i
] = old
->mask
[i
];
823 new->buflen
= old
->buflen
;
824 new->inode_f
= old
->inode_f
;
826 new->field_count
= old
->field_count
;
827 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
829 /* deep copy this information, updating the se_rule fields, because
830 * the originals will all be freed when the old rule is freed. */
831 for (i
= 0; i
< fcount
; i
++) {
832 switch (new->fields
[i
].type
) {
833 case AUDIT_SUBJ_USER
:
834 case AUDIT_SUBJ_ROLE
:
835 case AUDIT_SUBJ_TYPE
:
841 case AUDIT_OBJ_LEV_LOW
:
842 case AUDIT_OBJ_LEV_HIGH
:
843 err
= audit_dupe_selinux_field(&new->fields
[i
],
846 case AUDIT_FILTERKEY
:
847 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
854 audit_free_rule(entry
);
860 audit_get_watch(watch
);
867 /* Update inode info in audit rules based on filesystem event. */
868 static void audit_update_watch(struct audit_parent
*parent
,
869 const char *dname
, dev_t dev
,
870 unsigned long ino
, unsigned invalidating
)
872 struct audit_watch
*owatch
, *nwatch
, *nextw
;
873 struct audit_krule
*r
, *nextr
;
874 struct audit_entry
*oentry
, *nentry
;
875 struct audit_buffer
*ab
;
877 mutex_lock(&audit_filter_mutex
);
878 list_for_each_entry_safe(owatch
, nextw
, &parent
->watches
, wlist
) {
879 if (audit_compare_dname_path(dname
, owatch
->path
, NULL
))
882 /* If the update involves invalidating rules, do the inode-based
883 * filtering now, so we don't omit records. */
885 audit_filter_inodes(current
, current
->audit_context
) == AUDIT_RECORD_CONTEXT
)
886 audit_set_auditable(current
->audit_context
);
888 nwatch
= audit_dupe_watch(owatch
);
889 if (unlikely(IS_ERR(nwatch
))) {
890 mutex_unlock(&audit_filter_mutex
);
891 audit_panic("error updating watch, skipping");
897 list_for_each_entry_safe(r
, nextr
, &owatch
->rules
, rlist
) {
899 oentry
= container_of(r
, struct audit_entry
, rule
);
900 list_del(&oentry
->rule
.rlist
);
901 list_del_rcu(&oentry
->list
);
903 nentry
= audit_dupe_rule(&oentry
->rule
, nwatch
);
904 if (unlikely(IS_ERR(nentry
)))
905 audit_panic("error updating watch, removing");
907 int h
= audit_hash_ino((u32
)ino
);
908 list_add(&nentry
->rule
.rlist
, &nwatch
->rules
);
909 list_add_rcu(&nentry
->list
, &audit_inode_hash
[h
]);
912 call_rcu(&oentry
->rcu
, audit_free_rule_rcu
);
915 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
916 audit_log_format(ab
, "audit updated rules specifying watch=");
917 audit_log_untrustedstring(ab
, owatch
->path
);
918 audit_log_format(ab
, " with dev=%u ino=%lu\n", dev
, ino
);
921 audit_remove_watch(owatch
);
922 goto add_watch_to_parent
; /* event applies to a single watch */
924 mutex_unlock(&audit_filter_mutex
);
928 list_add(&nwatch
->wlist
, &parent
->watches
);
929 mutex_unlock(&audit_filter_mutex
);
933 /* Remove all watches & rules associated with a parent that is going away. */
934 static void audit_remove_parent_watches(struct audit_parent
*parent
)
936 struct audit_watch
*w
, *nextw
;
937 struct audit_krule
*r
, *nextr
;
938 struct audit_entry
*e
;
940 mutex_lock(&audit_filter_mutex
);
941 parent
->flags
|= AUDIT_PARENT_INVALID
;
942 list_for_each_entry_safe(w
, nextw
, &parent
->watches
, wlist
) {
943 list_for_each_entry_safe(r
, nextr
, &w
->rules
, rlist
) {
944 e
= container_of(r
, struct audit_entry
, rule
);
946 list_del_rcu(&e
->list
);
947 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
949 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
950 "audit implicitly removed rule from list=%d\n",
953 audit_remove_watch(w
);
955 mutex_unlock(&audit_filter_mutex
);
958 /* Unregister inotify watches for parents on in_list.
959 * Generates an IN_IGNORED event. */
960 static void audit_inotify_unregister(struct list_head
*in_list
)
962 struct audit_parent
*p
, *n
;
964 list_for_each_entry_safe(p
, n
, in_list
, ilist
) {
966 inotify_rm_watch(audit_ih
, &p
->wdata
);
967 /* the put matching the get in audit_do_del_rule() */
968 put_inotify_watch(&p
->wdata
);
972 /* Find an existing audit rule.
973 * Caller must hold audit_filter_mutex to prevent stale rule data. */
974 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
975 struct list_head
*list
)
977 struct audit_entry
*e
, *found
= NULL
;
980 if (entry
->rule
.watch
) {
981 /* we don't know the inode number, so must walk entire hash */
982 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
983 list
= &audit_inode_hash
[h
];
984 list_for_each_entry(e
, list
, list
)
985 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
993 list_for_each_entry(e
, list
, list
)
994 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
1003 /* Get path information necessary for adding watches. */
1004 static int audit_get_nd(char *path
, struct nameidata
**ndp
,
1005 struct nameidata
**ndw
)
1007 struct nameidata
*ndparent
, *ndwatch
;
1010 ndparent
= kmalloc(sizeof(*ndparent
), GFP_KERNEL
);
1011 if (unlikely(!ndparent
))
1014 ndwatch
= kmalloc(sizeof(*ndwatch
), GFP_KERNEL
);
1015 if (unlikely(!ndwatch
)) {
1020 err
= path_lookup(path
, LOOKUP_PARENT
, ndparent
);
1027 err
= path_lookup(path
, 0, ndwatch
);
1039 /* Release resources used for watch path information. */
1040 static void audit_put_nd(struct nameidata
*ndp
, struct nameidata
*ndw
)
1052 /* Associate the given rule with an existing parent inotify_watch.
1053 * Caller must hold audit_filter_mutex. */
1054 static void audit_add_to_parent(struct audit_krule
*krule
,
1055 struct audit_parent
*parent
)
1057 struct audit_watch
*w
, *watch
= krule
->watch
;
1058 int watch_found
= 0;
1060 list_for_each_entry(w
, &parent
->watches
, wlist
) {
1061 if (strcmp(watch
->path
, w
->path
))
1066 /* put krule's and initial refs to temporary watch */
1067 audit_put_watch(watch
);
1068 audit_put_watch(watch
);
1071 krule
->watch
= watch
= w
;
1076 get_inotify_watch(&parent
->wdata
);
1077 watch
->parent
= parent
;
1079 list_add(&watch
->wlist
, &parent
->watches
);
1081 list_add(&krule
->rlist
, &watch
->rules
);
1084 /* Find a matching watch entry, or add this one.
1085 * Caller must hold audit_filter_mutex. */
1086 static int audit_add_watch(struct audit_krule
*krule
, struct nameidata
*ndp
,
1087 struct nameidata
*ndw
)
1089 struct audit_watch
*watch
= krule
->watch
;
1090 struct inotify_watch
*i_watch
;
1091 struct audit_parent
*parent
;
1094 /* update watch filter fields */
1096 watch
->dev
= ndw
->dentry
->d_inode
->i_sb
->s_dev
;
1097 watch
->ino
= ndw
->dentry
->d_inode
->i_ino
;
1100 /* The audit_filter_mutex must not be held during inotify calls because
1101 * we hold it during inotify event callback processing. If an existing
1102 * inotify watch is found, inotify_find_watch() grabs a reference before
1105 mutex_unlock(&audit_filter_mutex
);
1107 if (inotify_find_watch(audit_ih
, ndp
->dentry
->d_inode
, &i_watch
) < 0) {
1108 parent
= audit_init_parent(ndp
);
1109 if (IS_ERR(parent
)) {
1110 /* caller expects mutex locked */
1111 mutex_lock(&audit_filter_mutex
);
1112 return PTR_ERR(parent
);
1115 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
1117 mutex_lock(&audit_filter_mutex
);
1119 /* parent was moved before we took audit_filter_mutex */
1120 if (parent
->flags
& AUDIT_PARENT_INVALID
)
1123 audit_add_to_parent(krule
, parent
);
1125 /* match get in audit_init_parent or inotify_find_watch */
1126 put_inotify_watch(&parent
->wdata
);
1130 /* Add rule to given filterlist if not a duplicate. */
1131 static inline int audit_add_rule(struct audit_entry
*entry
,
1132 struct list_head
*list
)
1134 struct audit_entry
*e
;
1135 struct audit_field
*inode_f
= entry
->rule
.inode_f
;
1136 struct audit_watch
*watch
= entry
->rule
.watch
;
1137 struct nameidata
*ndp
, *ndw
;
1138 int h
, err
, putnd_needed
= 0;
1139 #ifdef CONFIG_AUDITSYSCALL
1142 /* If either of these, don't count towards total */
1143 if (entry
->rule
.listnr
== AUDIT_FILTER_USER
||
1144 entry
->rule
.listnr
== AUDIT_FILTER_TYPE
)
1149 h
= audit_hash_ino(inode_f
->val
);
1150 list
= &audit_inode_hash
[h
];
1153 mutex_lock(&audit_filter_mutex
);
1154 e
= audit_find_rule(entry
, list
);
1155 mutex_unlock(&audit_filter_mutex
);
1161 /* Avoid calling path_lookup under audit_filter_mutex. */
1163 err
= audit_get_nd(watch
->path
, &ndp
, &ndw
);
1169 mutex_lock(&audit_filter_mutex
);
1171 /* audit_filter_mutex is dropped and re-taken during this call */
1172 err
= audit_add_watch(&entry
->rule
, ndp
, ndw
);
1174 mutex_unlock(&audit_filter_mutex
);
1177 h
= audit_hash_ino((u32
)watch
->ino
);
1178 list
= &audit_inode_hash
[h
];
1181 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
1182 list_add_rcu(&entry
->list
, list
);
1183 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
1185 list_add_tail_rcu(&entry
->list
, list
);
1187 #ifdef CONFIG_AUDITSYSCALL
1191 mutex_unlock(&audit_filter_mutex
);
1194 audit_put_nd(ndp
, ndw
);
1200 audit_put_nd(ndp
, ndw
);
1202 audit_put_watch(watch
); /* tmp watch, matches initial get */
1206 /* Remove an existing rule from filterlist. */
1207 static inline int audit_del_rule(struct audit_entry
*entry
,
1208 struct list_head
*list
)
1210 struct audit_entry
*e
;
1211 struct audit_field
*inode_f
= entry
->rule
.inode_f
;
1212 struct audit_watch
*watch
, *tmp_watch
= entry
->rule
.watch
;
1213 LIST_HEAD(inotify_list
);
1215 #ifdef CONFIG_AUDITSYSCALL
1218 /* If either of these, don't count towards total */
1219 if (entry
->rule
.listnr
== AUDIT_FILTER_USER
||
1220 entry
->rule
.listnr
== AUDIT_FILTER_TYPE
)
1225 h
= audit_hash_ino(inode_f
->val
);
1226 list
= &audit_inode_hash
[h
];
1229 mutex_lock(&audit_filter_mutex
);
1230 e
= audit_find_rule(entry
, list
);
1232 mutex_unlock(&audit_filter_mutex
);
1237 watch
= e
->rule
.watch
;
1239 struct audit_parent
*parent
= watch
->parent
;
1241 list_del(&e
->rule
.rlist
);
1243 if (list_empty(&watch
->rules
)) {
1244 audit_remove_watch(watch
);
1246 if (list_empty(&parent
->watches
)) {
1247 /* Put parent on the inotify un-registration
1248 * list. Grab a reference before releasing
1249 * audit_filter_mutex, to be released in
1250 * audit_inotify_unregister(). */
1251 list_add(&parent
->ilist
, &inotify_list
);
1252 get_inotify_watch(&parent
->wdata
);
1257 list_del_rcu(&e
->list
);
1258 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1260 #ifdef CONFIG_AUDITSYSCALL
1264 mutex_unlock(&audit_filter_mutex
);
1266 if (!list_empty(&inotify_list
))
1267 audit_inotify_unregister(&inotify_list
);
1271 audit_put_watch(tmp_watch
); /* match initial get */
1276 /* List rules using struct audit_rule. Exists for backward
1277 * compatibility with userspace. */
1278 static void audit_list(int pid
, int seq
, struct sk_buff_head
*q
)
1280 struct sk_buff
*skb
;
1281 struct audit_entry
*entry
;
1284 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1285 * iterator to sync with list writers. */
1286 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1287 list_for_each_entry(entry
, &audit_filter_list
[i
], list
) {
1288 struct audit_rule
*rule
;
1290 rule
= audit_krule_to_rule(&entry
->rule
);
1291 if (unlikely(!rule
))
1293 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1294 rule
, sizeof(*rule
));
1296 skb_queue_tail(q
, skb
);
1300 for (i
= 0; i
< AUDIT_INODE_BUCKETS
; i
++) {
1301 list_for_each_entry(entry
, &audit_inode_hash
[i
], list
) {
1302 struct audit_rule
*rule
;
1304 rule
= audit_krule_to_rule(&entry
->rule
);
1305 if (unlikely(!rule
))
1307 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1308 rule
, sizeof(*rule
));
1310 skb_queue_tail(q
, skb
);
1314 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 1, 1, NULL
, 0);
1316 skb_queue_tail(q
, skb
);
1319 /* List rules using struct audit_rule_data. */
1320 static void audit_list_rules(int pid
, int seq
, struct sk_buff_head
*q
)
1322 struct sk_buff
*skb
;
1323 struct audit_entry
*e
;
1326 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1327 * iterator to sync with list writers. */
1328 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1329 list_for_each_entry(e
, &audit_filter_list
[i
], list
) {
1330 struct audit_rule_data
*data
;
1332 data
= audit_krule_to_data(&e
->rule
);
1333 if (unlikely(!data
))
1335 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1336 data
, sizeof(*data
) + data
->buflen
);
1338 skb_queue_tail(q
, skb
);
1342 for (i
=0; i
< AUDIT_INODE_BUCKETS
; i
++) {
1343 list_for_each_entry(e
, &audit_inode_hash
[i
], list
) {
1344 struct audit_rule_data
*data
;
1346 data
= audit_krule_to_data(&e
->rule
);
1347 if (unlikely(!data
))
1349 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1350 data
, sizeof(*data
) + data
->buflen
);
1352 skb_queue_tail(q
, skb
);
1356 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1358 skb_queue_tail(q
, skb
);
1361 /* Log rule additions and removals */
1362 static void audit_log_rule_change(uid_t loginuid
, u32 sid
, char *action
,
1363 struct audit_krule
*rule
, int res
)
1365 struct audit_buffer
*ab
;
1367 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1370 audit_log_format(ab
, "auid=%u", loginuid
);
1374 if (selinux_ctxid_to_string(sid
, &ctx
, &len
))
1375 audit_log_format(ab
, " ssid=%u", sid
);
1377 audit_log_format(ab
, " subj=%s", ctx
);
1380 audit_log_format(ab
, " %s rule key=", action
);
1381 if (rule
->filterkey
)
1382 audit_log_untrustedstring(ab
, rule
->filterkey
);
1384 audit_log_format(ab
, "(null)");
1385 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1390 * audit_receive_filter - apply all rules to the specified message type
1391 * @type: audit message type
1392 * @pid: target pid for netlink audit messages
1393 * @uid: target uid for netlink audit messages
1394 * @seq: netlink audit message sequence (serial) number
1395 * @data: payload data
1396 * @datasz: size of payload data
1397 * @loginuid: loginuid of sender
1398 * @sid: SE Linux Security ID of sender
1400 int audit_receive_filter(int type
, int pid
, int uid
, int seq
, void *data
,
1401 size_t datasz
, uid_t loginuid
, u32 sid
)
1403 struct task_struct
*tsk
;
1404 struct audit_netlink_list
*dest
;
1406 struct audit_entry
*entry
;
1410 case AUDIT_LIST_RULES
:
1411 /* We can't just spew out the rules here because we might fill
1412 * the available socket buffer space and deadlock waiting for
1413 * auditctl to read from it... which isn't ever going to
1414 * happen if we're actually running in the context of auditctl
1415 * trying to _send_ the stuff */
1417 dest
= kmalloc(sizeof(struct audit_netlink_list
), GFP_KERNEL
);
1421 skb_queue_head_init(&dest
->q
);
1423 mutex_lock(&audit_filter_mutex
);
1424 if (type
== AUDIT_LIST
)
1425 audit_list(pid
, seq
, &dest
->q
);
1427 audit_list_rules(pid
, seq
, &dest
->q
);
1428 mutex_unlock(&audit_filter_mutex
);
1430 tsk
= kthread_run(audit_send_list
, dest
, "audit_send_list");
1432 skb_queue_purge(&dest
->q
);
1438 case AUDIT_ADD_RULE
:
1439 if (type
== AUDIT_ADD
)
1440 entry
= audit_rule_to_entry(data
);
1442 entry
= audit_data_to_entry(data
, datasz
);
1444 return PTR_ERR(entry
);
1446 err
= audit_add_rule(entry
,
1447 &audit_filter_list
[entry
->rule
.listnr
]);
1448 audit_log_rule_change(loginuid
, sid
, "add", &entry
->rule
, !err
);
1451 audit_free_rule(entry
);
1454 case AUDIT_DEL_RULE
:
1455 if (type
== AUDIT_DEL
)
1456 entry
= audit_rule_to_entry(data
);
1458 entry
= audit_data_to_entry(data
, datasz
);
1460 return PTR_ERR(entry
);
1462 err
= audit_del_rule(entry
,
1463 &audit_filter_list
[entry
->rule
.listnr
]);
1464 audit_log_rule_change(loginuid
, sid
, "remove", &entry
->rule
,
1467 audit_free_rule(entry
);
1476 int audit_comparator(const u32 left
, const u32 op
, const u32 right
)
1480 return (left
== right
);
1481 case AUDIT_NOT_EQUAL
:
1482 return (left
!= right
);
1483 case AUDIT_LESS_THAN
:
1484 return (left
< right
);
1485 case AUDIT_LESS_THAN_OR_EQUAL
:
1486 return (left
<= right
);
1487 case AUDIT_GREATER_THAN
:
1488 return (left
> right
);
1489 case AUDIT_GREATER_THAN_OR_EQUAL
:
1490 return (left
>= right
);
1496 /* Compare given dentry name with last component in given path,
1497 * return of 0 indicates a match. */
1498 int audit_compare_dname_path(const char *dname
, const char *path
,
1504 if (!dname
|| !path
)
1507 dlen
= strlen(dname
);
1508 plen
= strlen(path
);
1512 /* disregard trailing slashes */
1513 p
= path
+ plen
- 1;
1514 while ((*p
== '/') && (p
> path
))
1517 /* find last path component */
1521 else if (p
> path
) {
1528 /* return length of path's directory component */
1531 return strncmp(p
, dname
, dlen
);
1534 static int audit_filter_user_rules(struct netlink_skb_parms
*cb
,
1535 struct audit_krule
*rule
,
1536 enum audit_state
*state
)
1540 for (i
= 0; i
< rule
->field_count
; i
++) {
1541 struct audit_field
*f
= &rule
->fields
[i
];
1546 result
= audit_comparator(cb
->creds
.pid
, f
->op
, f
->val
);
1549 result
= audit_comparator(cb
->creds
.uid
, f
->op
, f
->val
);
1552 result
= audit_comparator(cb
->creds
.gid
, f
->op
, f
->val
);
1554 case AUDIT_LOGINUID
:
1555 result
= audit_comparator(cb
->loginuid
, f
->op
, f
->val
);
1562 switch (rule
->action
) {
1563 case AUDIT_NEVER
: *state
= AUDIT_DISABLED
; break;
1564 case AUDIT_ALWAYS
: *state
= AUDIT_RECORD_CONTEXT
; break;
1569 int audit_filter_user(struct netlink_skb_parms
*cb
, int type
)
1571 struct audit_entry
*e
;
1572 enum audit_state state
;
1576 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_USER
], list
) {
1577 if (audit_filter_user_rules(cb
, &e
->rule
, &state
)) {
1578 if (state
== AUDIT_DISABLED
)
1585 return ret
; /* Audit by default */
1588 int audit_filter_type(int type
)
1590 struct audit_entry
*e
;
1594 if (list_empty(&audit_filter_list
[AUDIT_FILTER_TYPE
]))
1595 goto unlock_and_return
;
1597 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_TYPE
],
1600 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1601 struct audit_field
*f
= &e
->rule
.fields
[i
];
1602 if (f
->type
== AUDIT_MSGTYPE
) {
1603 result
= audit_comparator(type
, f
->op
, f
->val
);
1609 goto unlock_and_return
;
1616 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1617 are selinux fields specified in the rule, 0 otherwise. */
1618 static inline int audit_rule_has_selinux(struct audit_krule
*rule
)
1622 for (i
= 0; i
< rule
->field_count
; i
++) {
1623 struct audit_field
*f
= &rule
->fields
[i
];
1625 case AUDIT_SUBJ_USER
:
1626 case AUDIT_SUBJ_ROLE
:
1627 case AUDIT_SUBJ_TYPE
:
1628 case AUDIT_SUBJ_SEN
:
1629 case AUDIT_SUBJ_CLR
:
1630 case AUDIT_OBJ_USER
:
1631 case AUDIT_OBJ_ROLE
:
1632 case AUDIT_OBJ_TYPE
:
1633 case AUDIT_OBJ_LEV_LOW
:
1634 case AUDIT_OBJ_LEV_HIGH
:
1642 /* This function will re-initialize the se_rule field of all applicable rules.
1643 * It will traverse the filter lists serarching for rules that contain selinux
1644 * specific filter fields. When such a rule is found, it is copied, the
1645 * selinux field is re-initialized, and the old rule is replaced with the
1647 int selinux_audit_rule_update(void)
1649 struct audit_entry
*entry
, *n
, *nentry
;
1650 struct audit_watch
*watch
;
1653 /* audit_filter_mutex synchronizes the writers */
1654 mutex_lock(&audit_filter_mutex
);
1656 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1657 list_for_each_entry_safe(entry
, n
, &audit_filter_list
[i
], list
) {
1658 if (!audit_rule_has_selinux(&entry
->rule
))
1661 watch
= entry
->rule
.watch
;
1662 nentry
= audit_dupe_rule(&entry
->rule
, watch
);
1663 if (unlikely(IS_ERR(nentry
))) {
1664 /* save the first error encountered for the
1667 err
= PTR_ERR(nentry
);
1668 audit_panic("error updating selinux filters");
1670 list_del(&entry
->rule
.rlist
);
1671 list_del_rcu(&entry
->list
);
1674 list_add(&nentry
->rule
.rlist
,
1676 list_del(&entry
->rule
.rlist
);
1678 list_replace_rcu(&entry
->list
, &nentry
->list
);
1680 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1684 mutex_unlock(&audit_filter_mutex
);
1689 /* Update watch data in audit rules based on inotify events. */
1690 void audit_handle_ievent(struct inotify_watch
*i_watch
, u32 wd
, u32 mask
,
1691 u32 cookie
, const char *dname
, struct inode
*inode
)
1693 struct audit_parent
*parent
;
1695 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
1697 if (mask
& (IN_CREATE
|IN_MOVED_TO
) && inode
)
1698 audit_update_watch(parent
, dname
, inode
->i_sb
->s_dev
,
1700 else if (mask
& (IN_DELETE
|IN_MOVED_FROM
))
1701 audit_update_watch(parent
, dname
, (dev_t
)-1, (unsigned long)-1, 1);
1702 /* inotify automatically removes the watch and sends IN_IGNORED */
1703 else if (mask
& (IN_DELETE_SELF
|IN_UNMOUNT
))
1704 audit_remove_parent_watches(parent
);
1705 /* inotify does not remove the watch, so remove it manually */
1706 else if(mask
& IN_MOVE_SELF
) {
1707 audit_remove_parent_watches(parent
);
1708 inotify_remove_watch_locked(audit_ih
, i_watch
);
1709 } else if (mask
& IN_IGNORED
)
1710 put_inotify_watch(i_watch
);