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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/kernel.h>
25 #include <linux/audit.h>
26 #include <linux/kthread.h>
27 #include <linux/mutex.h>
29 #include <linux/namei.h>
30 #include <linux/netlink.h>
31 #include <linux/sched.h>
32 #include <linux/slab.h>
33 #include <linux/security.h>
34 #include <net/net_namespace.h>
42 * Synchronizes writes and blocking reads of audit's filterlist
43 * data. Rcu is used to traverse the filterlist and access
44 * contents of structs audit_entry, audit_watch and opaque
45 * LSM rules during filtering. If modified, these structures
46 * must be copied and replace their counterparts in the filterlist.
47 * An audit_parent struct is not accessed during filtering, so may
48 * be written directly provided audit_filter_mutex is held.
51 /* Audit filter lists, defined in <linux/audit.h> */
52 struct list_head audit_filter_list
[AUDIT_NR_FILTERS
] = {
53 LIST_HEAD_INIT(audit_filter_list
[0]),
54 LIST_HEAD_INIT(audit_filter_list
[1]),
55 LIST_HEAD_INIT(audit_filter_list
[2]),
56 LIST_HEAD_INIT(audit_filter_list
[3]),
57 LIST_HEAD_INIT(audit_filter_list
[4]),
58 LIST_HEAD_INIT(audit_filter_list
[5]),
59 #if AUDIT_NR_FILTERS != 6
60 #error Fix audit_filter_list initialiser
63 static struct list_head audit_rules_list
[AUDIT_NR_FILTERS
] = {
64 LIST_HEAD_INIT(audit_rules_list
[0]),
65 LIST_HEAD_INIT(audit_rules_list
[1]),
66 LIST_HEAD_INIT(audit_rules_list
[2]),
67 LIST_HEAD_INIT(audit_rules_list
[3]),
68 LIST_HEAD_INIT(audit_rules_list
[4]),
69 LIST_HEAD_INIT(audit_rules_list
[5]),
72 DEFINE_MUTEX(audit_filter_mutex
);
74 static void audit_free_lsm_field(struct audit_field
*f
)
85 case AUDIT_OBJ_LEV_LOW
:
86 case AUDIT_OBJ_LEV_HIGH
:
88 security_audit_rule_free(f
->lsm_rule
);
92 static inline void audit_free_rule(struct audit_entry
*e
)
95 struct audit_krule
*erule
= &e
->rule
;
97 /* some rules don't have associated watches */
99 audit_put_watch(erule
->watch
);
101 for (i
= 0; i
< erule
->field_count
; i
++)
102 audit_free_lsm_field(&erule
->fields
[i
]);
103 kfree(erule
->fields
);
104 kfree(erule
->filterkey
);
108 void audit_free_rule_rcu(struct rcu_head
*head
)
110 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
114 /* Initialize an audit filterlist entry. */
115 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
117 struct audit_entry
*entry
;
118 struct audit_field
*fields
;
120 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
121 if (unlikely(!entry
))
124 fields
= kcalloc(field_count
, sizeof(*fields
), GFP_KERNEL
);
125 if (unlikely(!fields
)) {
129 entry
->rule
.fields
= fields
;
134 /* Unpack a filter field's string representation from user-space
136 char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
140 if (!*bufp
|| (len
== 0) || (len
> *remain
))
141 return ERR_PTR(-EINVAL
);
143 /* Of the currently implemented string fields, PATH_MAX
144 * defines the longest valid length.
147 return ERR_PTR(-ENAMETOOLONG
);
149 str
= kmalloc(len
+ 1, GFP_KERNEL
);
151 return ERR_PTR(-ENOMEM
);
153 memcpy(str
, *bufp
, len
);
161 /* Translate an inode field to kernel representation. */
162 static inline int audit_to_inode(struct audit_krule
*krule
,
163 struct audit_field
*f
)
165 if (krule
->listnr
!= AUDIT_FILTER_EXIT
||
166 krule
->inode_f
|| krule
->watch
|| krule
->tree
||
167 (f
->op
!= Audit_equal
&& f
->op
!= Audit_not_equal
))
174 static __u32
*classes
[AUDIT_SYSCALL_CLASSES
];
176 int __init
audit_register_class(int class, unsigned *list
)
178 __u32
*p
= kcalloc(AUDIT_BITMASK_SIZE
, sizeof(__u32
), GFP_KERNEL
);
181 while (*list
!= ~0U) {
182 unsigned n
= *list
++;
183 if (n
>= AUDIT_BITMASK_SIZE
* 32 - AUDIT_SYSCALL_CLASSES
) {
187 p
[AUDIT_WORD(n
)] |= AUDIT_BIT(n
);
189 if (class >= AUDIT_SYSCALL_CLASSES
|| classes
[class]) {
197 int audit_match_class(int class, unsigned syscall
)
199 if (unlikely(syscall
>= AUDIT_BITMASK_SIZE
* 32))
201 if (unlikely(class >= AUDIT_SYSCALL_CLASSES
|| !classes
[class]))
203 return classes
[class][AUDIT_WORD(syscall
)] & AUDIT_BIT(syscall
);
206 #ifdef CONFIG_AUDITSYSCALL
207 static inline int audit_match_class_bits(int class, u32
*mask
)
211 if (classes
[class]) {
212 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
213 if (mask
[i
] & classes
[class][i
])
219 static int audit_match_signal(struct audit_entry
*entry
)
221 struct audit_field
*arch
= entry
->rule
.arch_f
;
224 /* When arch is unspecified, we must check both masks on biarch
225 * as syscall number alone is ambiguous. */
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
228 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
232 switch(audit_classify_arch(arch
->val
)) {
234 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
236 case 1: /* 32bit on biarch */
237 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
245 /* Common user-space to kernel rule translation. */
246 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule_data
*rule
)
249 struct audit_entry
*entry
;
253 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
257 #ifdef CONFIG_AUDITSYSCALL
258 case AUDIT_FILTER_ENTRY
:
259 if (rule
->action
== AUDIT_ALWAYS
)
261 case AUDIT_FILTER_EXIT
:
262 case AUDIT_FILTER_TASK
:
264 case AUDIT_FILTER_USER
:
265 case AUDIT_FILTER_TYPE
:
268 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
269 pr_err("AUDIT_POSSIBLE is deprecated\n");
272 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
274 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
278 entry
= audit_init_entry(rule
->field_count
);
282 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
283 entry
->rule
.listnr
= listnr
;
284 entry
->rule
.action
= rule
->action
;
285 entry
->rule
.field_count
= rule
->field_count
;
287 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
288 entry
->rule
.mask
[i
] = rule
->mask
[i
];
290 for (i
= 0; i
< AUDIT_SYSCALL_CLASSES
; i
++) {
291 int bit
= AUDIT_BITMASK_SIZE
* 32 - i
- 1;
292 __u32
*p
= &entry
->rule
.mask
[AUDIT_WORD(bit
)];
295 if (!(*p
& AUDIT_BIT(bit
)))
297 *p
&= ~AUDIT_BIT(bit
);
301 for (j
= 0; j
< AUDIT_BITMASK_SIZE
; j
++)
302 entry
->rule
.mask
[j
] |= class[j
];
312 static u32 audit_ops
[] =
314 [Audit_equal
] = AUDIT_EQUAL
,
315 [Audit_not_equal
] = AUDIT_NOT_EQUAL
,
316 [Audit_bitmask
] = AUDIT_BIT_MASK
,
317 [Audit_bittest
] = AUDIT_BIT_TEST
,
318 [Audit_lt
] = AUDIT_LESS_THAN
,
319 [Audit_gt
] = AUDIT_GREATER_THAN
,
320 [Audit_le
] = AUDIT_LESS_THAN_OR_EQUAL
,
321 [Audit_ge
] = AUDIT_GREATER_THAN_OR_EQUAL
,
324 static u32
audit_to_op(u32 op
)
327 for (n
= Audit_equal
; n
< Audit_bad
&& audit_ops
[n
] != op
; n
++)
332 /* check if an audit field is valid */
333 static int audit_field_valid(struct audit_entry
*entry
, struct audit_field
*f
)
337 if (entry
->rule
.listnr
!= AUDIT_FILTER_TYPE
&&
338 entry
->rule
.listnr
!= AUDIT_FILTER_USER
)
366 /* bit ops are only useful on syscall args */
367 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
374 case AUDIT_SUBJ_USER
:
375 case AUDIT_SUBJ_ROLE
:
376 case AUDIT_SUBJ_TYPE
:
382 case AUDIT_OBJ_LEV_LOW
:
383 case AUDIT_OBJ_LEV_HIGH
:
386 case AUDIT_FILTERKEY
:
388 case AUDIT_LOGINUID_SET
:
389 if ((f
->val
!= 0) && (f
->val
!= 1))
393 if (f
->op
!= Audit_not_equal
&& f
->op
!= Audit_equal
)
401 if (f
->val
& ~S_IFMT
)
404 case AUDIT_FIELD_COMPARE
:
405 if (f
->val
> AUDIT_MAX_FIELD_COMPARE
)
409 if (f
->op
!= Audit_not_equal
&& f
->op
!= Audit_equal
)
411 if (entry
->rule
.listnr
!= AUDIT_FILTER_EXIT
)
418 /* Translate struct audit_rule_data to kernel's rule representation. */
419 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
423 struct audit_entry
*entry
;
425 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
428 struct audit_fsnotify_mark
*audit_mark
;
430 entry
= audit_to_entry_common(data
);
435 for (i
= 0; i
< data
->field_count
; i
++) {
436 struct audit_field
*f
= &entry
->rule
.fields
[i
];
441 f
->op
= audit_to_op(data
->fieldflags
[i
]);
442 if (f
->op
== Audit_bad
)
445 f
->type
= data
->fields
[i
];
446 f_val
= data
->values
[i
];
448 /* Support legacy tests for a valid loginuid */
449 if ((f
->type
== AUDIT_LOGINUID
) && (f_val
== AUDIT_UID_UNSET
)) {
450 f
->type
= AUDIT_LOGINUID_SET
;
452 entry
->rule
.pflags
|= AUDIT_LOGINUID_LEGACY
;
455 err
= audit_field_valid(entry
, f
);
467 f
->uid
= make_kuid(current_user_ns(), f_val
);
468 if (!uid_valid(f
->uid
))
476 f
->gid
= make_kgid(current_user_ns(), f_val
);
477 if (!gid_valid(f
->gid
))
482 entry
->rule
.arch_f
= f
;
484 case AUDIT_SUBJ_USER
:
485 case AUDIT_SUBJ_ROLE
:
486 case AUDIT_SUBJ_TYPE
:
492 case AUDIT_OBJ_LEV_LOW
:
493 case AUDIT_OBJ_LEV_HIGH
:
494 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
499 entry
->rule
.buflen
+= f_val
;
501 err
= security_audit_rule_init(f
->type
, f
->op
, str
,
502 (void **)&f
->lsm_rule
);
503 /* Keep currently invalid fields around in case they
504 * become valid after a policy reload. */
505 if (err
== -EINVAL
) {
506 pr_warn("audit rule for LSM \'%s\' is invalid\n",
513 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
518 err
= audit_to_watch(&entry
->rule
, str
, f_val
, f
->op
);
523 entry
->rule
.buflen
+= f_val
;
526 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
531 err
= audit_make_tree(&entry
->rule
, str
, f
->op
);
535 entry
->rule
.buflen
+= f_val
;
539 err
= audit_to_inode(&entry
->rule
, f
);
543 case AUDIT_FILTERKEY
:
544 if (entry
->rule
.filterkey
|| f_val
> AUDIT_MAX_KEY_LEN
)
546 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
551 entry
->rule
.buflen
+= f_val
;
552 entry
->rule
.filterkey
= str
;
555 if (entry
->rule
.exe
|| f_val
> PATH_MAX
)
557 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
562 audit_mark
= audit_alloc_mark(&entry
->rule
, str
, f_val
);
563 if (IS_ERR(audit_mark
)) {
565 err
= PTR_ERR(audit_mark
);
568 entry
->rule
.buflen
+= f_val
;
569 entry
->rule
.exe
= audit_mark
;
577 if (entry
->rule
.inode_f
&& entry
->rule
.inode_f
->op
== Audit_not_equal
)
578 entry
->rule
.inode_f
= NULL
;
584 if (entry
->rule
.tree
)
585 audit_put_tree(entry
->rule
.tree
); /* that's the temporary one */
587 audit_remove_mark(entry
->rule
.exe
); /* that's the template one */
588 audit_free_rule(entry
);
592 /* Pack a filter field's string representation into data block. */
593 static inline size_t audit_pack_string(void **bufp
, const char *str
)
595 size_t len
= strlen(str
);
597 memcpy(*bufp
, str
, len
);
603 /* Translate kernel rule representation to struct audit_rule_data. */
604 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
606 struct audit_rule_data
*data
;
610 data
= kmalloc(sizeof(*data
) + krule
->buflen
, GFP_KERNEL
);
613 memset(data
, 0, sizeof(*data
));
615 data
->flags
= krule
->flags
| krule
->listnr
;
616 data
->action
= krule
->action
;
617 data
->field_count
= krule
->field_count
;
619 for (i
= 0; i
< data
->field_count
; i
++) {
620 struct audit_field
*f
= &krule
->fields
[i
];
622 data
->fields
[i
] = f
->type
;
623 data
->fieldflags
[i
] = audit_ops
[f
->op
];
625 case AUDIT_SUBJ_USER
:
626 case AUDIT_SUBJ_ROLE
:
627 case AUDIT_SUBJ_TYPE
:
633 case AUDIT_OBJ_LEV_LOW
:
634 case AUDIT_OBJ_LEV_HIGH
:
635 data
->buflen
+= data
->values
[i
] =
636 audit_pack_string(&bufp
, f
->lsm_str
);
639 data
->buflen
+= data
->values
[i
] =
640 audit_pack_string(&bufp
,
641 audit_watch_path(krule
->watch
));
644 data
->buflen
+= data
->values
[i
] =
645 audit_pack_string(&bufp
,
646 audit_tree_path(krule
->tree
));
648 case AUDIT_FILTERKEY
:
649 data
->buflen
+= data
->values
[i
] =
650 audit_pack_string(&bufp
, krule
->filterkey
);
653 data
->buflen
+= data
->values
[i
] =
654 audit_pack_string(&bufp
, audit_mark_path(krule
->exe
));
656 case AUDIT_LOGINUID_SET
:
657 if (krule
->pflags
& AUDIT_LOGINUID_LEGACY
&& !f
->val
) {
658 data
->fields
[i
] = AUDIT_LOGINUID
;
659 data
->values
[i
] = AUDIT_UID_UNSET
;
662 /* fallthrough if set */
664 data
->values
[i
] = f
->val
;
667 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
672 /* Compare two rules in kernel format. Considered success if rules
674 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
678 if (a
->flags
!= b
->flags
||
679 a
->pflags
!= b
->pflags
||
680 a
->listnr
!= b
->listnr
||
681 a
->action
!= b
->action
||
682 a
->field_count
!= b
->field_count
)
685 for (i
= 0; i
< a
->field_count
; i
++) {
686 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
687 a
->fields
[i
].op
!= b
->fields
[i
].op
)
690 switch(a
->fields
[i
].type
) {
691 case AUDIT_SUBJ_USER
:
692 case AUDIT_SUBJ_ROLE
:
693 case AUDIT_SUBJ_TYPE
:
699 case AUDIT_OBJ_LEV_LOW
:
700 case AUDIT_OBJ_LEV_HIGH
:
701 if (strcmp(a
->fields
[i
].lsm_str
, b
->fields
[i
].lsm_str
))
705 if (strcmp(audit_watch_path(a
->watch
),
706 audit_watch_path(b
->watch
)))
710 if (strcmp(audit_tree_path(a
->tree
),
711 audit_tree_path(b
->tree
)))
714 case AUDIT_FILTERKEY
:
715 /* both filterkeys exist based on above type compare */
716 if (strcmp(a
->filterkey
, b
->filterkey
))
720 /* both paths exist based on above type compare */
721 if (strcmp(audit_mark_path(a
->exe
),
722 audit_mark_path(b
->exe
)))
731 if (!uid_eq(a
->fields
[i
].uid
, b
->fields
[i
].uid
))
739 if (!gid_eq(a
->fields
[i
].gid
, b
->fields
[i
].gid
))
743 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
748 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
749 if (a
->mask
[i
] != b
->mask
[i
])
755 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
757 static inline int audit_dupe_lsm_field(struct audit_field
*df
,
758 struct audit_field
*sf
)
763 /* our own copy of lsm_str */
764 lsm_str
= kstrdup(sf
->lsm_str
, GFP_KERNEL
);
765 if (unlikely(!lsm_str
))
767 df
->lsm_str
= lsm_str
;
769 /* our own (refreshed) copy of lsm_rule */
770 ret
= security_audit_rule_init(df
->type
, df
->op
, df
->lsm_str
,
771 (void **)&df
->lsm_rule
);
772 /* Keep currently invalid fields around in case they
773 * become valid after a policy reload. */
774 if (ret
== -EINVAL
) {
775 pr_warn("audit rule for LSM \'%s\' is invalid\n",
783 /* Duplicate an audit rule. This will be a deep copy with the exception
784 * of the watch - that pointer is carried over. The LSM specific fields
785 * will be updated in the copy. The point is to be able to replace the old
786 * rule with the new rule in the filterlist, then free the old rule.
787 * The rlist element is undefined; list manipulations are handled apart from
788 * the initial copy. */
789 struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
)
791 u32 fcount
= old
->field_count
;
792 struct audit_entry
*entry
;
793 struct audit_krule
*new;
797 entry
= audit_init_entry(fcount
);
798 if (unlikely(!entry
))
799 return ERR_PTR(-ENOMEM
);
802 new->flags
= old
->flags
;
803 new->pflags
= old
->pflags
;
804 new->listnr
= old
->listnr
;
805 new->action
= old
->action
;
806 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
807 new->mask
[i
] = old
->mask
[i
];
808 new->prio
= old
->prio
;
809 new->buflen
= old
->buflen
;
810 new->inode_f
= old
->inode_f
;
811 new->field_count
= old
->field_count
;
814 * note that we are OK with not refcounting here; audit_match_tree()
815 * never dereferences tree and we can't get false positives there
816 * since we'd have to have rule gone from the list *and* removed
817 * before the chunks found by lookup had been allocated, i.e. before
818 * the beginning of list scan.
820 new->tree
= old
->tree
;
821 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
823 /* deep copy this information, updating the lsm_rule fields, because
824 * the originals will all be freed when the old rule is freed. */
825 for (i
= 0; i
< fcount
; i
++) {
826 switch (new->fields
[i
].type
) {
827 case AUDIT_SUBJ_USER
:
828 case AUDIT_SUBJ_ROLE
:
829 case AUDIT_SUBJ_TYPE
:
835 case AUDIT_OBJ_LEV_LOW
:
836 case AUDIT_OBJ_LEV_HIGH
:
837 err
= audit_dupe_lsm_field(&new->fields
[i
],
840 case AUDIT_FILTERKEY
:
841 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
848 err
= audit_dupe_exe(new, old
);
853 audit_remove_mark(new->exe
);
854 audit_free_rule(entry
);
860 audit_get_watch(old
->watch
);
861 new->watch
= old
->watch
;
867 /* Find an existing audit rule.
868 * Caller must hold audit_filter_mutex to prevent stale rule data. */
869 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
870 struct list_head
**p
)
872 struct audit_entry
*e
, *found
= NULL
;
873 struct list_head
*list
;
876 if (entry
->rule
.inode_f
) {
877 h
= audit_hash_ino(entry
->rule
.inode_f
->val
);
878 *p
= list
= &audit_inode_hash
[h
];
879 } else if (entry
->rule
.watch
) {
880 /* we don't know the inode number, so must walk entire hash */
881 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
882 list
= &audit_inode_hash
[h
];
883 list_for_each_entry(e
, list
, list
)
884 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
891 *p
= list
= &audit_filter_list
[entry
->rule
.listnr
];
894 list_for_each_entry(e
, list
, list
)
895 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
904 static u64 prio_low
= ~0ULL/2;
905 static u64 prio_high
= ~0ULL/2 - 1;
907 /* Add rule to given filterlist if not a duplicate. */
908 static inline int audit_add_rule(struct audit_entry
*entry
)
910 struct audit_entry
*e
;
911 struct audit_watch
*watch
= entry
->rule
.watch
;
912 struct audit_tree
*tree
= entry
->rule
.tree
;
913 struct list_head
*list
;
915 #ifdef CONFIG_AUDITSYSCALL
918 /* If either of these, don't count towards total */
919 if (entry
->rule
.listnr
== AUDIT_FILTER_USER
||
920 entry
->rule
.listnr
== AUDIT_FILTER_TYPE
)
924 mutex_lock(&audit_filter_mutex
);
925 e
= audit_find_rule(entry
, &list
);
927 mutex_unlock(&audit_filter_mutex
);
929 /* normally audit_add_tree_rule() will free it on failure */
931 audit_put_tree(tree
);
936 /* audit_filter_mutex is dropped and re-taken during this call */
937 err
= audit_add_watch(&entry
->rule
, &list
);
939 mutex_unlock(&audit_filter_mutex
);
941 * normally audit_add_tree_rule() will free it
945 audit_put_tree(tree
);
950 err
= audit_add_tree_rule(&entry
->rule
);
952 mutex_unlock(&audit_filter_mutex
);
957 entry
->rule
.prio
= ~0ULL;
958 if (entry
->rule
.listnr
== AUDIT_FILTER_EXIT
) {
959 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
)
960 entry
->rule
.prio
= ++prio_high
;
962 entry
->rule
.prio
= --prio_low
;
965 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
966 list_add(&entry
->rule
.list
,
967 &audit_rules_list
[entry
->rule
.listnr
]);
968 list_add_rcu(&entry
->list
, list
);
969 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
971 list_add_tail(&entry
->rule
.list
,
972 &audit_rules_list
[entry
->rule
.listnr
]);
973 list_add_tail_rcu(&entry
->list
, list
);
975 #ifdef CONFIG_AUDITSYSCALL
979 if (!audit_match_signal(entry
))
982 mutex_unlock(&audit_filter_mutex
);
987 /* Remove an existing rule from filterlist. */
988 int audit_del_rule(struct audit_entry
*entry
)
990 struct audit_entry
*e
;
991 struct audit_tree
*tree
= entry
->rule
.tree
;
992 struct list_head
*list
;
994 #ifdef CONFIG_AUDITSYSCALL
997 /* If either of these, don't count towards total */
998 if (entry
->rule
.listnr
== AUDIT_FILTER_USER
||
999 entry
->rule
.listnr
== AUDIT_FILTER_TYPE
)
1003 mutex_lock(&audit_filter_mutex
);
1004 e
= audit_find_rule(entry
, &list
);
1011 audit_remove_watch_rule(&e
->rule
);
1014 audit_remove_tree_rule(&e
->rule
);
1017 audit_remove_mark_rule(&e
->rule
);
1019 #ifdef CONFIG_AUDITSYSCALL
1023 if (!audit_match_signal(entry
))
1027 list_del_rcu(&e
->list
);
1028 list_del(&e
->rule
.list
);
1029 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1032 mutex_unlock(&audit_filter_mutex
);
1035 audit_put_tree(tree
); /* that's the temporary one */
1040 /* List rules using struct audit_rule_data. */
1041 static void audit_list_rules(__u32 portid
, int seq
, struct sk_buff_head
*q
)
1043 struct sk_buff
*skb
;
1044 struct audit_krule
*r
;
1047 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1048 * iterator to sync with list writers. */
1049 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1050 list_for_each_entry(r
, &audit_rules_list
[i
], list
) {
1051 struct audit_rule_data
*data
;
1053 data
= audit_krule_to_data(r
);
1054 if (unlikely(!data
))
1056 skb
= audit_make_reply(portid
, seq
, AUDIT_LIST_RULES
,
1058 sizeof(*data
) + data
->buflen
);
1060 skb_queue_tail(q
, skb
);
1064 skb
= audit_make_reply(portid
, seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1066 skb_queue_tail(q
, skb
);
1069 /* Log rule additions and removals */
1070 static void audit_log_rule_change(char *action
, struct audit_krule
*rule
, int res
)
1072 struct audit_buffer
*ab
;
1073 uid_t loginuid
= from_kuid(&init_user_ns
, audit_get_loginuid(current
));
1074 unsigned int sessionid
= audit_get_sessionid(current
);
1079 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1082 audit_log_format(ab
, "auid=%u ses=%u" ,loginuid
, sessionid
);
1083 audit_log_task_context(ab
);
1084 audit_log_format(ab
, " op=");
1085 audit_log_string(ab
, action
);
1086 audit_log_key(ab
, rule
->filterkey
);
1087 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1092 * audit_rule_change - apply all rules to the specified message type
1093 * @type: audit message type
1094 * @portid: target port id for netlink audit messages
1095 * @seq: netlink audit message sequence (serial) number
1096 * @data: payload data
1097 * @datasz: size of payload data
1099 int audit_rule_change(int type
, __u32 portid
, int seq
, void *data
,
1103 struct audit_entry
*entry
;
1106 case AUDIT_ADD_RULE
:
1107 entry
= audit_data_to_entry(data
, datasz
);
1109 return PTR_ERR(entry
);
1110 err
= audit_add_rule(entry
);
1111 audit_log_rule_change("add_rule", &entry
->rule
, !err
);
1113 case AUDIT_DEL_RULE
:
1114 entry
= audit_data_to_entry(data
, datasz
);
1116 return PTR_ERR(entry
);
1117 err
= audit_del_rule(entry
);
1118 audit_log_rule_change("remove_rule", &entry
->rule
, !err
);
1125 if (err
|| type
== AUDIT_DEL_RULE
) {
1126 if (entry
->rule
.exe
)
1127 audit_remove_mark(entry
->rule
.exe
);
1128 audit_free_rule(entry
);
1135 * audit_list_rules_send - list the audit rules
1136 * @request_skb: skb of request we are replying to (used to target the reply)
1137 * @seq: netlink audit message sequence (serial) number
1139 int audit_list_rules_send(struct sk_buff
*request_skb
, int seq
)
1141 u32 portid
= NETLINK_CB(request_skb
).portid
;
1142 struct net
*net
= sock_net(NETLINK_CB(request_skb
).sk
);
1143 struct task_struct
*tsk
;
1144 struct audit_netlink_list
*dest
;
1147 /* We can't just spew out the rules here because we might fill
1148 * the available socket buffer space and deadlock waiting for
1149 * auditctl to read from it... which isn't ever going to
1150 * happen if we're actually running in the context of auditctl
1151 * trying to _send_ the stuff */
1153 dest
= kmalloc(sizeof(struct audit_netlink_list
), GFP_KERNEL
);
1156 dest
->net
= get_net(net
);
1157 dest
->portid
= portid
;
1158 skb_queue_head_init(&dest
->q
);
1160 mutex_lock(&audit_filter_mutex
);
1161 audit_list_rules(portid
, seq
, &dest
->q
);
1162 mutex_unlock(&audit_filter_mutex
);
1164 tsk
= kthread_run(audit_send_list
, dest
, "audit_send_list");
1166 skb_queue_purge(&dest
->q
);
1174 int audit_comparator(u32 left
, u32 op
, u32 right
)
1178 return (left
== right
);
1179 case Audit_not_equal
:
1180 return (left
!= right
);
1182 return (left
< right
);
1184 return (left
<= right
);
1186 return (left
> right
);
1188 return (left
>= right
);
1190 return (left
& right
);
1192 return ((left
& right
) == right
);
1199 int audit_uid_comparator(kuid_t left
, u32 op
, kuid_t right
)
1203 return uid_eq(left
, right
);
1204 case Audit_not_equal
:
1205 return !uid_eq(left
, right
);
1207 return uid_lt(left
, right
);
1209 return uid_lte(left
, right
);
1211 return uid_gt(left
, right
);
1213 return uid_gte(left
, right
);
1222 int audit_gid_comparator(kgid_t left
, u32 op
, kgid_t right
)
1226 return gid_eq(left
, right
);
1227 case Audit_not_equal
:
1228 return !gid_eq(left
, right
);
1230 return gid_lt(left
, right
);
1232 return gid_lte(left
, right
);
1234 return gid_gt(left
, right
);
1236 return gid_gte(left
, right
);
1246 * parent_len - find the length of the parent portion of a pathname
1247 * @path: pathname of which to determine length
1249 int parent_len(const char *path
)
1254 plen
= strlen(path
);
1259 /* disregard trailing slashes */
1260 p
= path
+ plen
- 1;
1261 while ((*p
== '/') && (p
> path
))
1264 /* walk backward until we find the next slash or hit beginning */
1265 while ((*p
!= '/') && (p
> path
))
1268 /* did we find a slash? Then increment to include it in path */
1276 * audit_compare_dname_path - compare given dentry name with last component in
1277 * given path. Return of 0 indicates a match.
1278 * @dname: dentry name that we're comparing
1279 * @path: full pathname that we're comparing
1280 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1281 * here indicates that we must compute this value.
1283 int audit_compare_dname_path(const char *dname
, const char *path
, int parentlen
)
1288 dlen
= strlen(dname
);
1289 pathlen
= strlen(path
);
1293 parentlen
= parentlen
== AUDIT_NAME_FULL
? parent_len(path
) : parentlen
;
1294 if (pathlen
- parentlen
!= dlen
)
1297 p
= path
+ parentlen
;
1299 return strncmp(p
, dname
, dlen
);
1302 int audit_filter(int msgtype
, unsigned int listtype
)
1304 struct audit_entry
*e
;
1305 int ret
= 1; /* Audit by default */
1308 if (list_empty(&audit_filter_list
[listtype
]))
1309 goto unlock_and_return
;
1310 list_for_each_entry_rcu(e
, &audit_filter_list
[listtype
], list
) {
1313 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1314 struct audit_field
*f
= &e
->rule
.fields
[i
];
1320 pid
= task_pid_nr(current
);
1321 result
= audit_comparator(pid
, f
->op
, f
->val
);
1324 result
= audit_uid_comparator(current_uid(), f
->op
, f
->uid
);
1327 result
= audit_gid_comparator(current_gid(), f
->op
, f
->gid
);
1329 case AUDIT_LOGINUID
:
1330 result
= audit_uid_comparator(audit_get_loginuid(current
),
1333 case AUDIT_LOGINUID_SET
:
1334 result
= audit_comparator(audit_loginuid_set(current
),
1338 result
= audit_comparator(msgtype
, f
->op
, f
->val
);
1340 case AUDIT_SUBJ_USER
:
1341 case AUDIT_SUBJ_ROLE
:
1342 case AUDIT_SUBJ_TYPE
:
1343 case AUDIT_SUBJ_SEN
:
1344 case AUDIT_SUBJ_CLR
:
1346 security_task_getsecid(current
, &sid
);
1347 result
= security_audit_rule_match(sid
,
1348 f
->type
, f
->op
, f
->lsm_rule
, NULL
);
1352 goto unlock_and_return
;
1354 if (result
< 0) /* error */
1355 goto unlock_and_return
;
1360 if (e
->rule
.action
== AUDIT_NEVER
|| listtype
== AUDIT_FILTER_TYPE
)
1370 static int update_lsm_rule(struct audit_krule
*r
)
1372 struct audit_entry
*entry
= container_of(r
, struct audit_entry
, rule
);
1373 struct audit_entry
*nentry
;
1376 if (!security_audit_rule_known(r
))
1379 nentry
= audit_dupe_rule(r
);
1380 if (entry
->rule
.exe
)
1381 audit_remove_mark(entry
->rule
.exe
);
1382 if (IS_ERR(nentry
)) {
1383 /* save the first error encountered for the
1385 err
= PTR_ERR(nentry
);
1386 audit_panic("error updating LSM filters");
1388 list_del(&r
->rlist
);
1389 list_del_rcu(&entry
->list
);
1392 if (r
->watch
|| r
->tree
)
1393 list_replace_init(&r
->rlist
, &nentry
->rule
.rlist
);
1394 list_replace_rcu(&entry
->list
, &nentry
->list
);
1395 list_replace(&r
->list
, &nentry
->rule
.list
);
1397 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1402 /* This function will re-initialize the lsm_rule field of all applicable rules.
1403 * It will traverse the filter lists serarching for rules that contain LSM
1404 * specific filter fields. When such a rule is found, it is copied, the
1405 * LSM field is re-initialized, and the old rule is replaced with the
1407 int audit_update_lsm_rules(void)
1409 struct audit_krule
*r
, *n
;
1412 /* audit_filter_mutex synchronizes the writers */
1413 mutex_lock(&audit_filter_mutex
);
1415 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1416 list_for_each_entry_safe(r
, n
, &audit_rules_list
[i
], list
) {
1417 int res
= update_lsm_rule(r
);
1422 mutex_unlock(&audit_filter_mutex
);