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 LIST_HEAD_INIT(audit_filter_list
[6]),
60 #if AUDIT_NR_FILTERS != 7
61 #error Fix audit_filter_list initialiser
64 static struct list_head audit_rules_list
[AUDIT_NR_FILTERS
] = {
65 LIST_HEAD_INIT(audit_rules_list
[0]),
66 LIST_HEAD_INIT(audit_rules_list
[1]),
67 LIST_HEAD_INIT(audit_rules_list
[2]),
68 LIST_HEAD_INIT(audit_rules_list
[3]),
69 LIST_HEAD_INIT(audit_rules_list
[4]),
70 LIST_HEAD_INIT(audit_rules_list
[5]),
71 LIST_HEAD_INIT(audit_rules_list
[6]),
74 DEFINE_MUTEX(audit_filter_mutex
);
76 static void audit_free_lsm_field(struct audit_field
*f
)
87 case AUDIT_OBJ_LEV_LOW
:
88 case AUDIT_OBJ_LEV_HIGH
:
90 security_audit_rule_free(f
->lsm_rule
);
94 static inline void audit_free_rule(struct audit_entry
*e
)
97 struct audit_krule
*erule
= &e
->rule
;
99 /* some rules don't have associated watches */
101 audit_put_watch(erule
->watch
);
103 for (i
= 0; i
< erule
->field_count
; i
++)
104 audit_free_lsm_field(&erule
->fields
[i
]);
105 kfree(erule
->fields
);
106 kfree(erule
->filterkey
);
110 void audit_free_rule_rcu(struct rcu_head
*head
)
112 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
116 /* Initialize an audit filterlist entry. */
117 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
119 struct audit_entry
*entry
;
120 struct audit_field
*fields
;
122 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
123 if (unlikely(!entry
))
126 fields
= kcalloc(field_count
, sizeof(*fields
), GFP_KERNEL
);
127 if (unlikely(!fields
)) {
131 entry
->rule
.fields
= fields
;
136 /* Unpack a filter field's string representation from user-space
138 char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
142 if (!*bufp
|| (len
== 0) || (len
> *remain
))
143 return ERR_PTR(-EINVAL
);
145 /* Of the currently implemented string fields, PATH_MAX
146 * defines the longest valid length.
149 return ERR_PTR(-ENAMETOOLONG
);
151 str
= kmalloc(len
+ 1, GFP_KERNEL
);
153 return ERR_PTR(-ENOMEM
);
155 memcpy(str
, *bufp
, len
);
163 /* Translate an inode field to kernel representation. */
164 static inline int audit_to_inode(struct audit_krule
*krule
,
165 struct audit_field
*f
)
167 if (krule
->listnr
!= AUDIT_FILTER_EXIT
||
168 krule
->inode_f
|| krule
->watch
|| krule
->tree
||
169 (f
->op
!= Audit_equal
&& f
->op
!= Audit_not_equal
))
176 static __u32
*classes
[AUDIT_SYSCALL_CLASSES
];
178 int __init
audit_register_class(int class, unsigned *list
)
180 __u32
*p
= kcalloc(AUDIT_BITMASK_SIZE
, sizeof(__u32
), GFP_KERNEL
);
183 while (*list
!= ~0U) {
184 unsigned n
= *list
++;
185 if (n
>= AUDIT_BITMASK_SIZE
* 32 - AUDIT_SYSCALL_CLASSES
) {
189 p
[AUDIT_WORD(n
)] |= AUDIT_BIT(n
);
191 if (class >= AUDIT_SYSCALL_CLASSES
|| classes
[class]) {
199 int audit_match_class(int class, unsigned syscall
)
201 if (unlikely(syscall
>= AUDIT_BITMASK_SIZE
* 32))
203 if (unlikely(class >= AUDIT_SYSCALL_CLASSES
|| !classes
[class]))
205 return classes
[class][AUDIT_WORD(syscall
)] & AUDIT_BIT(syscall
);
208 #ifdef CONFIG_AUDITSYSCALL
209 static inline int audit_match_class_bits(int class, u32
*mask
)
213 if (classes
[class]) {
214 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
215 if (mask
[i
] & classes
[class][i
])
221 static int audit_match_signal(struct audit_entry
*entry
)
223 struct audit_field
*arch
= entry
->rule
.arch_f
;
226 /* When arch is unspecified, we must check both masks on biarch
227 * as syscall number alone is ambiguous. */
228 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
230 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
234 switch(audit_classify_arch(arch
->val
)) {
236 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
238 case 1: /* 32bit on biarch */
239 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
247 /* Common user-space to kernel rule translation. */
248 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule_data
*rule
)
251 struct audit_entry
*entry
;
255 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
259 #ifdef CONFIG_AUDITSYSCALL
260 case AUDIT_FILTER_ENTRY
:
261 if (rule
->action
== AUDIT_ALWAYS
)
263 case AUDIT_FILTER_EXIT
:
264 case AUDIT_FILTER_TASK
:
266 case AUDIT_FILTER_USER
:
267 case AUDIT_FILTER_TYPE
:
268 case AUDIT_FILTER_FS
:
271 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
272 pr_err("AUDIT_POSSIBLE is deprecated\n");
275 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
277 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
281 entry
= audit_init_entry(rule
->field_count
);
285 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
286 entry
->rule
.listnr
= listnr
;
287 entry
->rule
.action
= rule
->action
;
288 entry
->rule
.field_count
= rule
->field_count
;
290 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
291 entry
->rule
.mask
[i
] = rule
->mask
[i
];
293 for (i
= 0; i
< AUDIT_SYSCALL_CLASSES
; i
++) {
294 int bit
= AUDIT_BITMASK_SIZE
* 32 - i
- 1;
295 __u32
*p
= &entry
->rule
.mask
[AUDIT_WORD(bit
)];
298 if (!(*p
& AUDIT_BIT(bit
)))
300 *p
&= ~AUDIT_BIT(bit
);
304 for (j
= 0; j
< AUDIT_BITMASK_SIZE
; j
++)
305 entry
->rule
.mask
[j
] |= class[j
];
315 static u32 audit_ops
[] =
317 [Audit_equal
] = AUDIT_EQUAL
,
318 [Audit_not_equal
] = AUDIT_NOT_EQUAL
,
319 [Audit_bitmask
] = AUDIT_BIT_MASK
,
320 [Audit_bittest
] = AUDIT_BIT_TEST
,
321 [Audit_lt
] = AUDIT_LESS_THAN
,
322 [Audit_gt
] = AUDIT_GREATER_THAN
,
323 [Audit_le
] = AUDIT_LESS_THAN_OR_EQUAL
,
324 [Audit_ge
] = AUDIT_GREATER_THAN_OR_EQUAL
,
327 static u32
audit_to_op(u32 op
)
330 for (n
= Audit_equal
; n
< Audit_bad
&& audit_ops
[n
] != op
; n
++)
335 /* check if an audit field is valid */
336 static int audit_field_valid(struct audit_entry
*entry
, struct audit_field
*f
)
340 if (entry
->rule
.listnr
!= AUDIT_FILTER_TYPE
&&
341 entry
->rule
.listnr
!= AUDIT_FILTER_USER
)
345 if (entry
->rule
.listnr
!= AUDIT_FILTER_FS
)
350 switch(entry
->rule
.listnr
) {
351 case AUDIT_FILTER_FS
:
354 case AUDIT_FILTERKEY
:
384 case AUDIT_SESSIONID
:
385 /* bit ops are only useful on syscall args */
386 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
393 case AUDIT_SUBJ_USER
:
394 case AUDIT_SUBJ_ROLE
:
395 case AUDIT_SUBJ_TYPE
:
401 case AUDIT_OBJ_LEV_LOW
:
402 case AUDIT_OBJ_LEV_HIGH
:
405 case AUDIT_FILTERKEY
:
407 case AUDIT_LOGINUID_SET
:
408 if ((f
->val
!= 0) && (f
->val
!= 1))
413 if (f
->op
!= Audit_not_equal
&& f
->op
!= Audit_equal
)
421 if (f
->val
& ~S_IFMT
)
424 case AUDIT_FIELD_COMPARE
:
425 if (f
->val
> AUDIT_MAX_FIELD_COMPARE
)
429 if (f
->op
!= Audit_equal
)
431 if (entry
->rule
.listnr
!= AUDIT_FILTER_EXIT
)
438 /* Translate struct audit_rule_data to kernel's rule representation. */
439 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
443 struct audit_entry
*entry
;
445 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
448 struct audit_fsnotify_mark
*audit_mark
;
450 entry
= audit_to_entry_common(data
);
455 for (i
= 0; i
< data
->field_count
; i
++) {
456 struct audit_field
*f
= &entry
->rule
.fields
[i
];
460 f
->op
= audit_to_op(data
->fieldflags
[i
]);
461 if (f
->op
== Audit_bad
)
464 f
->type
= data
->fields
[i
];
465 f
->val
= data
->values
[i
];
467 /* Support legacy tests for a valid loginuid */
468 if ((f
->type
== AUDIT_LOGINUID
) && (f
->val
== AUDIT_UID_UNSET
)) {
469 f
->type
= AUDIT_LOGINUID_SET
;
471 entry
->rule
.pflags
|= AUDIT_LOGINUID_LEGACY
;
474 err
= audit_field_valid(entry
, f
);
486 f
->uid
= make_kuid(current_user_ns(), f
->val
);
487 if (!uid_valid(f
->uid
))
495 f
->gid
= make_kgid(current_user_ns(), f
->val
);
496 if (!gid_valid(f
->gid
))
499 case AUDIT_SESSIONID
:
501 entry
->rule
.arch_f
= f
;
503 case AUDIT_SUBJ_USER
:
504 case AUDIT_SUBJ_ROLE
:
505 case AUDIT_SUBJ_TYPE
:
511 case AUDIT_OBJ_LEV_LOW
:
512 case AUDIT_OBJ_LEV_HIGH
:
513 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
516 entry
->rule
.buflen
+= f
->val
;
518 err
= security_audit_rule_init(f
->type
, f
->op
, str
,
519 (void **)&f
->lsm_rule
);
520 /* Keep currently invalid fields around in case they
521 * become valid after a policy reload. */
522 if (err
== -EINVAL
) {
523 pr_warn("audit rule for LSM \'%s\' is invalid\n",
534 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
537 entry
->rule
.buflen
+= f
->val
;
539 err
= audit_to_watch(&entry
->rule
, str
, f
->val
, f
->op
);
546 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
549 entry
->rule
.buflen
+= f
->val
;
551 err
= audit_make_tree(&entry
->rule
, str
, f
->op
);
557 err
= audit_to_inode(&entry
->rule
, f
);
561 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
;
571 if (entry
->rule
.exe
|| f
->val
> PATH_MAX
)
573 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
578 entry
->rule
.buflen
+= f
->val
;
580 audit_mark
= audit_alloc_mark(&entry
->rule
, str
, f
->val
);
581 if (IS_ERR(audit_mark
)) {
583 err
= PTR_ERR(audit_mark
);
586 entry
->rule
.exe
= audit_mark
;
591 if (entry
->rule
.inode_f
&& entry
->rule
.inode_f
->op
== Audit_not_equal
)
592 entry
->rule
.inode_f
= NULL
;
598 if (entry
->rule
.tree
)
599 audit_put_tree(entry
->rule
.tree
); /* that's the temporary one */
601 audit_remove_mark(entry
->rule
.exe
); /* that's the template one */
602 audit_free_rule(entry
);
606 /* Pack a filter field's string representation into data block. */
607 static inline size_t audit_pack_string(void **bufp
, const char *str
)
609 size_t len
= strlen(str
);
611 memcpy(*bufp
, str
, len
);
617 /* Translate kernel rule representation to struct audit_rule_data. */
618 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
620 struct audit_rule_data
*data
;
624 data
= kmalloc(sizeof(*data
) + krule
->buflen
, GFP_KERNEL
);
627 memset(data
, 0, sizeof(*data
));
629 data
->flags
= krule
->flags
| krule
->listnr
;
630 data
->action
= krule
->action
;
631 data
->field_count
= krule
->field_count
;
633 for (i
= 0; i
< data
->field_count
; i
++) {
634 struct audit_field
*f
= &krule
->fields
[i
];
636 data
->fields
[i
] = f
->type
;
637 data
->fieldflags
[i
] = audit_ops
[f
->op
];
639 case AUDIT_SUBJ_USER
:
640 case AUDIT_SUBJ_ROLE
:
641 case AUDIT_SUBJ_TYPE
:
647 case AUDIT_OBJ_LEV_LOW
:
648 case AUDIT_OBJ_LEV_HIGH
:
649 data
->buflen
+= data
->values
[i
] =
650 audit_pack_string(&bufp
, f
->lsm_str
);
653 data
->buflen
+= data
->values
[i
] =
654 audit_pack_string(&bufp
,
655 audit_watch_path(krule
->watch
));
658 data
->buflen
+= data
->values
[i
] =
659 audit_pack_string(&bufp
,
660 audit_tree_path(krule
->tree
));
662 case AUDIT_FILTERKEY
:
663 data
->buflen
+= data
->values
[i
] =
664 audit_pack_string(&bufp
, krule
->filterkey
);
667 data
->buflen
+= data
->values
[i
] =
668 audit_pack_string(&bufp
, audit_mark_path(krule
->exe
));
670 case AUDIT_LOGINUID_SET
:
671 if (krule
->pflags
& AUDIT_LOGINUID_LEGACY
&& !f
->val
) {
672 data
->fields
[i
] = AUDIT_LOGINUID
;
673 data
->values
[i
] = AUDIT_UID_UNSET
;
676 /* fallthrough if set */
678 data
->values
[i
] = f
->val
;
681 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
686 /* Compare two rules in kernel format. Considered success if rules
688 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
692 if (a
->flags
!= b
->flags
||
693 a
->pflags
!= b
->pflags
||
694 a
->listnr
!= b
->listnr
||
695 a
->action
!= b
->action
||
696 a
->field_count
!= b
->field_count
)
699 for (i
= 0; i
< a
->field_count
; i
++) {
700 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
701 a
->fields
[i
].op
!= b
->fields
[i
].op
)
704 switch(a
->fields
[i
].type
) {
705 case AUDIT_SUBJ_USER
:
706 case AUDIT_SUBJ_ROLE
:
707 case AUDIT_SUBJ_TYPE
:
713 case AUDIT_OBJ_LEV_LOW
:
714 case AUDIT_OBJ_LEV_HIGH
:
715 if (strcmp(a
->fields
[i
].lsm_str
, b
->fields
[i
].lsm_str
))
719 if (strcmp(audit_watch_path(a
->watch
),
720 audit_watch_path(b
->watch
)))
724 if (strcmp(audit_tree_path(a
->tree
),
725 audit_tree_path(b
->tree
)))
728 case AUDIT_FILTERKEY
:
729 /* both filterkeys exist based on above type compare */
730 if (strcmp(a
->filterkey
, b
->filterkey
))
734 /* both paths exist based on above type compare */
735 if (strcmp(audit_mark_path(a
->exe
),
736 audit_mark_path(b
->exe
)))
745 if (!uid_eq(a
->fields
[i
].uid
, b
->fields
[i
].uid
))
753 if (!gid_eq(a
->fields
[i
].gid
, b
->fields
[i
].gid
))
757 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
762 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
763 if (a
->mask
[i
] != b
->mask
[i
])
769 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
771 static inline int audit_dupe_lsm_field(struct audit_field
*df
,
772 struct audit_field
*sf
)
777 /* our own copy of lsm_str */
778 lsm_str
= kstrdup(sf
->lsm_str
, GFP_KERNEL
);
779 if (unlikely(!lsm_str
))
781 df
->lsm_str
= lsm_str
;
783 /* our own (refreshed) copy of lsm_rule */
784 ret
= security_audit_rule_init(df
->type
, df
->op
, df
->lsm_str
,
785 (void **)&df
->lsm_rule
);
786 /* Keep currently invalid fields around in case they
787 * become valid after a policy reload. */
788 if (ret
== -EINVAL
) {
789 pr_warn("audit rule for LSM \'%s\' is invalid\n",
797 /* Duplicate an audit rule. This will be a deep copy with the exception
798 * of the watch - that pointer is carried over. The LSM 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 struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
)
805 u32 fcount
= old
->field_count
;
806 struct audit_entry
*entry
;
807 struct audit_krule
*new;
811 entry
= audit_init_entry(fcount
);
812 if (unlikely(!entry
))
813 return ERR_PTR(-ENOMEM
);
816 new->flags
= old
->flags
;
817 new->pflags
= old
->pflags
;
818 new->listnr
= old
->listnr
;
819 new->action
= old
->action
;
820 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
821 new->mask
[i
] = old
->mask
[i
];
822 new->prio
= old
->prio
;
823 new->buflen
= old
->buflen
;
824 new->inode_f
= old
->inode_f
;
825 new->field_count
= old
->field_count
;
828 * note that we are OK with not refcounting here; audit_match_tree()
829 * never dereferences tree and we can't get false positives there
830 * since we'd have to have rule gone from the list *and* removed
831 * before the chunks found by lookup had been allocated, i.e. before
832 * the beginning of list scan.
834 new->tree
= old
->tree
;
835 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
837 /* deep copy this information, updating the lsm_rule fields, because
838 * the originals will all be freed when the old rule is freed. */
839 for (i
= 0; i
< fcount
; i
++) {
840 switch (new->fields
[i
].type
) {
841 case AUDIT_SUBJ_USER
:
842 case AUDIT_SUBJ_ROLE
:
843 case AUDIT_SUBJ_TYPE
:
849 case AUDIT_OBJ_LEV_LOW
:
850 case AUDIT_OBJ_LEV_HIGH
:
851 err
= audit_dupe_lsm_field(&new->fields
[i
],
854 case AUDIT_FILTERKEY
:
855 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
862 err
= audit_dupe_exe(new, old
);
867 audit_remove_mark(new->exe
);
868 audit_free_rule(entry
);
874 audit_get_watch(old
->watch
);
875 new->watch
= old
->watch
;
881 /* Find an existing audit rule.
882 * Caller must hold audit_filter_mutex to prevent stale rule data. */
883 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
884 struct list_head
**p
)
886 struct audit_entry
*e
, *found
= NULL
;
887 struct list_head
*list
;
890 if (entry
->rule
.inode_f
) {
891 h
= audit_hash_ino(entry
->rule
.inode_f
->val
);
892 *p
= list
= &audit_inode_hash
[h
];
893 } else if (entry
->rule
.watch
) {
894 /* we don't know the inode number, so must walk entire hash */
895 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
896 list
= &audit_inode_hash
[h
];
897 list_for_each_entry(e
, list
, list
)
898 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
905 *p
= list
= &audit_filter_list
[entry
->rule
.listnr
];
908 list_for_each_entry(e
, list
, list
)
909 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
918 static u64 prio_low
= ~0ULL/2;
919 static u64 prio_high
= ~0ULL/2 - 1;
921 /* Add rule to given filterlist if not a duplicate. */
922 static inline int audit_add_rule(struct audit_entry
*entry
)
924 struct audit_entry
*e
;
925 struct audit_watch
*watch
= entry
->rule
.watch
;
926 struct audit_tree
*tree
= entry
->rule
.tree
;
927 struct list_head
*list
;
929 #ifdef CONFIG_AUDITSYSCALL
932 /* If any of these, don't count towards total */
933 switch(entry
->rule
.listnr
) {
934 case AUDIT_FILTER_USER
:
935 case AUDIT_FILTER_TYPE
:
936 case AUDIT_FILTER_FS
:
941 mutex_lock(&audit_filter_mutex
);
942 e
= audit_find_rule(entry
, &list
);
944 mutex_unlock(&audit_filter_mutex
);
946 /* normally audit_add_tree_rule() will free it on failure */
948 audit_put_tree(tree
);
953 /* audit_filter_mutex is dropped and re-taken during this call */
954 err
= audit_add_watch(&entry
->rule
, &list
);
956 mutex_unlock(&audit_filter_mutex
);
958 * normally audit_add_tree_rule() will free it
962 audit_put_tree(tree
);
967 err
= audit_add_tree_rule(&entry
->rule
);
969 mutex_unlock(&audit_filter_mutex
);
974 entry
->rule
.prio
= ~0ULL;
975 if (entry
->rule
.listnr
== AUDIT_FILTER_EXIT
) {
976 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
)
977 entry
->rule
.prio
= ++prio_high
;
979 entry
->rule
.prio
= --prio_low
;
982 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
983 list_add(&entry
->rule
.list
,
984 &audit_rules_list
[entry
->rule
.listnr
]);
985 list_add_rcu(&entry
->list
, list
);
986 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
988 list_add_tail(&entry
->rule
.list
,
989 &audit_rules_list
[entry
->rule
.listnr
]);
990 list_add_tail_rcu(&entry
->list
, list
);
992 #ifdef CONFIG_AUDITSYSCALL
996 if (!audit_match_signal(entry
))
999 mutex_unlock(&audit_filter_mutex
);
1004 /* Remove an existing rule from filterlist. */
1005 int audit_del_rule(struct audit_entry
*entry
)
1007 struct audit_entry
*e
;
1008 struct audit_tree
*tree
= entry
->rule
.tree
;
1009 struct list_head
*list
;
1011 #ifdef CONFIG_AUDITSYSCALL
1014 /* If any of these, don't count towards total */
1015 switch(entry
->rule
.listnr
) {
1016 case AUDIT_FILTER_USER
:
1017 case AUDIT_FILTER_TYPE
:
1018 case AUDIT_FILTER_FS
:
1023 mutex_lock(&audit_filter_mutex
);
1024 e
= audit_find_rule(entry
, &list
);
1031 audit_remove_watch_rule(&e
->rule
);
1034 audit_remove_tree_rule(&e
->rule
);
1037 audit_remove_mark_rule(&e
->rule
);
1039 #ifdef CONFIG_AUDITSYSCALL
1043 if (!audit_match_signal(entry
))
1047 list_del_rcu(&e
->list
);
1048 list_del(&e
->rule
.list
);
1049 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1052 mutex_unlock(&audit_filter_mutex
);
1055 audit_put_tree(tree
); /* that's the temporary one */
1060 /* List rules using struct audit_rule_data. */
1061 static void audit_list_rules(int seq
, struct sk_buff_head
*q
)
1063 struct sk_buff
*skb
;
1064 struct audit_krule
*r
;
1067 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1068 * iterator to sync with list writers. */
1069 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1070 list_for_each_entry(r
, &audit_rules_list
[i
], list
) {
1071 struct audit_rule_data
*data
;
1073 data
= audit_krule_to_data(r
);
1074 if (unlikely(!data
))
1076 skb
= audit_make_reply(seq
, AUDIT_LIST_RULES
, 0, 1,
1078 sizeof(*data
) + data
->buflen
);
1080 skb_queue_tail(q
, skb
);
1084 skb
= audit_make_reply(seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1086 skb_queue_tail(q
, skb
);
1089 /* Log rule additions and removals */
1090 static void audit_log_rule_change(char *action
, struct audit_krule
*rule
, int res
)
1092 struct audit_buffer
*ab
;
1093 uid_t loginuid
= from_kuid(&init_user_ns
, audit_get_loginuid(current
));
1094 unsigned int sessionid
= audit_get_sessionid(current
);
1099 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1102 audit_log_format(ab
, "auid=%u ses=%u" ,loginuid
, sessionid
);
1103 audit_log_task_context(ab
);
1104 audit_log_format(ab
, " op=%s", action
);
1105 audit_log_key(ab
, rule
->filterkey
);
1106 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1111 * audit_rule_change - apply all rules to the specified message type
1112 * @type: audit message type
1113 * @seq: netlink audit message sequence (serial) number
1114 * @data: payload data
1115 * @datasz: size of payload data
1117 int audit_rule_change(int type
, int seq
, void *data
, size_t datasz
)
1120 struct audit_entry
*entry
;
1122 entry
= audit_data_to_entry(data
, datasz
);
1124 return PTR_ERR(entry
);
1127 case AUDIT_ADD_RULE
:
1128 err
= audit_add_rule(entry
);
1129 audit_log_rule_change("add_rule", &entry
->rule
, !err
);
1131 case AUDIT_DEL_RULE
:
1132 err
= audit_del_rule(entry
);
1133 audit_log_rule_change("remove_rule", &entry
->rule
, !err
);
1140 if (err
|| type
== AUDIT_DEL_RULE
) {
1141 if (entry
->rule
.exe
)
1142 audit_remove_mark(entry
->rule
.exe
);
1143 audit_free_rule(entry
);
1150 * audit_list_rules_send - list the audit rules
1151 * @request_skb: skb of request we are replying to (used to target the reply)
1152 * @seq: netlink audit message sequence (serial) number
1154 int audit_list_rules_send(struct sk_buff
*request_skb
, int seq
)
1156 u32 portid
= NETLINK_CB(request_skb
).portid
;
1157 struct net
*net
= sock_net(NETLINK_CB(request_skb
).sk
);
1158 struct task_struct
*tsk
;
1159 struct audit_netlink_list
*dest
;
1162 /* We can't just spew out the rules here because we might fill
1163 * the available socket buffer space and deadlock waiting for
1164 * auditctl to read from it... which isn't ever going to
1165 * happen if we're actually running in the context of auditctl
1166 * trying to _send_ the stuff */
1168 dest
= kmalloc(sizeof(struct audit_netlink_list
), GFP_KERNEL
);
1171 dest
->net
= get_net(net
);
1172 dest
->portid
= portid
;
1173 skb_queue_head_init(&dest
->q
);
1175 mutex_lock(&audit_filter_mutex
);
1176 audit_list_rules(seq
, &dest
->q
);
1177 mutex_unlock(&audit_filter_mutex
);
1179 tsk
= kthread_run(audit_send_list
, dest
, "audit_send_list");
1181 skb_queue_purge(&dest
->q
);
1189 int audit_comparator(u32 left
, u32 op
, u32 right
)
1193 return (left
== right
);
1194 case Audit_not_equal
:
1195 return (left
!= right
);
1197 return (left
< right
);
1199 return (left
<= right
);
1201 return (left
> right
);
1203 return (left
>= right
);
1205 return (left
& right
);
1207 return ((left
& right
) == right
);
1214 int audit_uid_comparator(kuid_t left
, u32 op
, kuid_t right
)
1218 return uid_eq(left
, right
);
1219 case Audit_not_equal
:
1220 return !uid_eq(left
, right
);
1222 return uid_lt(left
, right
);
1224 return uid_lte(left
, right
);
1226 return uid_gt(left
, right
);
1228 return uid_gte(left
, right
);
1237 int audit_gid_comparator(kgid_t left
, u32 op
, kgid_t right
)
1241 return gid_eq(left
, right
);
1242 case Audit_not_equal
:
1243 return !gid_eq(left
, right
);
1245 return gid_lt(left
, right
);
1247 return gid_lte(left
, right
);
1249 return gid_gt(left
, right
);
1251 return gid_gte(left
, right
);
1261 * parent_len - find the length of the parent portion of a pathname
1262 * @path: pathname of which to determine length
1264 int parent_len(const char *path
)
1269 plen
= strlen(path
);
1274 /* disregard trailing slashes */
1275 p
= path
+ plen
- 1;
1276 while ((*p
== '/') && (p
> path
))
1279 /* walk backward until we find the next slash or hit beginning */
1280 while ((*p
!= '/') && (p
> path
))
1283 /* did we find a slash? Then increment to include it in path */
1291 * audit_compare_dname_path - compare given dentry name with last component in
1292 * given path. Return of 0 indicates a match.
1293 * @dname: dentry name that we're comparing
1294 * @path: full pathname that we're comparing
1295 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1296 * here indicates that we must compute this value.
1298 int audit_compare_dname_path(const char *dname
, const char *path
, int parentlen
)
1303 dlen
= strlen(dname
);
1304 pathlen
= strlen(path
);
1308 parentlen
= parentlen
== AUDIT_NAME_FULL
? parent_len(path
) : parentlen
;
1309 if (pathlen
- parentlen
!= dlen
)
1312 p
= path
+ parentlen
;
1314 return strncmp(p
, dname
, dlen
);
1317 int audit_filter(int msgtype
, unsigned int listtype
)
1319 struct audit_entry
*e
;
1320 int ret
= 1; /* Audit by default */
1323 if (list_empty(&audit_filter_list
[listtype
]))
1324 goto unlock_and_return
;
1325 list_for_each_entry_rcu(e
, &audit_filter_list
[listtype
], list
) {
1328 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1329 struct audit_field
*f
= &e
->rule
.fields
[i
];
1335 pid
= task_pid_nr(current
);
1336 result
= audit_comparator(pid
, f
->op
, f
->val
);
1339 result
= audit_uid_comparator(current_uid(), f
->op
, f
->uid
);
1342 result
= audit_gid_comparator(current_gid(), f
->op
, f
->gid
);
1344 case AUDIT_LOGINUID
:
1345 result
= audit_uid_comparator(audit_get_loginuid(current
),
1348 case AUDIT_LOGINUID_SET
:
1349 result
= audit_comparator(audit_loginuid_set(current
),
1353 result
= audit_comparator(msgtype
, f
->op
, f
->val
);
1355 case AUDIT_SUBJ_USER
:
1356 case AUDIT_SUBJ_ROLE
:
1357 case AUDIT_SUBJ_TYPE
:
1358 case AUDIT_SUBJ_SEN
:
1359 case AUDIT_SUBJ_CLR
:
1361 security_task_getsecid(current
, &sid
);
1362 result
= security_audit_rule_match(sid
,
1363 f
->type
, f
->op
, f
->lsm_rule
, NULL
);
1367 goto unlock_and_return
;
1369 if (result
< 0) /* error */
1370 goto unlock_and_return
;
1375 if (e
->rule
.action
== AUDIT_NEVER
|| listtype
== AUDIT_FILTER_TYPE
)
1385 static int update_lsm_rule(struct audit_krule
*r
)
1387 struct audit_entry
*entry
= container_of(r
, struct audit_entry
, rule
);
1388 struct audit_entry
*nentry
;
1391 if (!security_audit_rule_known(r
))
1394 nentry
= audit_dupe_rule(r
);
1395 if (entry
->rule
.exe
)
1396 audit_remove_mark(entry
->rule
.exe
);
1397 if (IS_ERR(nentry
)) {
1398 /* save the first error encountered for the
1400 err
= PTR_ERR(nentry
);
1401 audit_panic("error updating LSM filters");
1403 list_del(&r
->rlist
);
1404 list_del_rcu(&entry
->list
);
1407 if (r
->watch
|| r
->tree
)
1408 list_replace_init(&r
->rlist
, &nentry
->rule
.rlist
);
1409 list_replace_rcu(&entry
->list
, &nentry
->list
);
1410 list_replace(&r
->list
, &nentry
->rule
.list
);
1412 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1417 /* This function will re-initialize the lsm_rule field of all applicable rules.
1418 * It will traverse the filter lists serarching for rules that contain LSM
1419 * specific filter fields. When such a rule is found, it is copied, the
1420 * LSM field is re-initialized, and the old rule is replaced with the
1422 int audit_update_lsm_rules(void)
1424 struct audit_krule
*r
, *n
;
1427 /* audit_filter_mutex synchronizes the writers */
1428 mutex_lock(&audit_filter_mutex
);
1430 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1431 list_for_each_entry_safe(r
, n
, &audit_rules_list
[i
], list
) {
1432 int res
= update_lsm_rule(r
);
1437 mutex_unlock(&audit_filter_mutex
);