1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* auditfilter.c -- filtering of audit events
4 * Copyright 2003-2004 Red Hat, Inc.
5 * Copyright 2005 Hewlett-Packard Development Company, L.P.
6 * Copyright 2005 IBM Corporation
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/kernel.h>
12 #include <linux/audit.h>
13 #include <linux/kthread.h>
14 #include <linux/mutex.h>
16 #include <linux/namei.h>
17 #include <linux/netlink.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/security.h>
21 #include <net/net_namespace.h>
29 * Synchronizes writes and blocking reads of audit's filterlist
30 * data. Rcu is used to traverse the filterlist and access
31 * contents of structs audit_entry, audit_watch and opaque
32 * LSM rules during filtering. If modified, these structures
33 * must be copied and replace their counterparts in the filterlist.
34 * An audit_parent struct is not accessed during filtering, so may
35 * be written directly provided audit_filter_mutex is held.
38 /* Audit filter lists, defined in <linux/audit.h> */
39 struct list_head audit_filter_list
[AUDIT_NR_FILTERS
] = {
40 LIST_HEAD_INIT(audit_filter_list
[0]),
41 LIST_HEAD_INIT(audit_filter_list
[1]),
42 LIST_HEAD_INIT(audit_filter_list
[2]),
43 LIST_HEAD_INIT(audit_filter_list
[3]),
44 LIST_HEAD_INIT(audit_filter_list
[4]),
45 LIST_HEAD_INIT(audit_filter_list
[5]),
46 LIST_HEAD_INIT(audit_filter_list
[6]),
47 LIST_HEAD_INIT(audit_filter_list
[7]),
48 #if AUDIT_NR_FILTERS != 8
49 #error Fix audit_filter_list initialiser
52 static struct list_head audit_rules_list
[AUDIT_NR_FILTERS
] = {
53 LIST_HEAD_INIT(audit_rules_list
[0]),
54 LIST_HEAD_INIT(audit_rules_list
[1]),
55 LIST_HEAD_INIT(audit_rules_list
[2]),
56 LIST_HEAD_INIT(audit_rules_list
[3]),
57 LIST_HEAD_INIT(audit_rules_list
[4]),
58 LIST_HEAD_INIT(audit_rules_list
[5]),
59 LIST_HEAD_INIT(audit_rules_list
[6]),
60 LIST_HEAD_INIT(audit_rules_list
[7]),
63 DEFINE_MUTEX(audit_filter_mutex
);
65 static void audit_free_lsm_field(struct audit_field
*f
)
76 case AUDIT_OBJ_LEV_LOW
:
77 case AUDIT_OBJ_LEV_HIGH
:
79 security_audit_rule_free(f
->lsm_rule
);
83 static inline void audit_free_rule(struct audit_entry
*e
)
86 struct audit_krule
*erule
= &e
->rule
;
88 /* some rules don't have associated watches */
90 audit_put_watch(erule
->watch
);
92 for (i
= 0; i
< erule
->field_count
; i
++)
93 audit_free_lsm_field(&erule
->fields
[i
]);
95 kfree(erule
->filterkey
);
99 void audit_free_rule_rcu(struct rcu_head
*head
)
101 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
105 /* Initialize an audit filterlist entry. */
106 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
108 struct audit_entry
*entry
;
109 struct audit_field
*fields
;
111 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
112 if (unlikely(!entry
))
115 fields
= kcalloc(field_count
, sizeof(*fields
), GFP_KERNEL
);
116 if (unlikely(!fields
)) {
120 entry
->rule
.fields
= fields
;
125 /* Unpack a filter field's string representation from user-space
127 char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
131 if (!*bufp
|| (len
== 0) || (len
> *remain
))
132 return ERR_PTR(-EINVAL
);
134 /* Of the currently implemented string fields, PATH_MAX
135 * defines the longest valid length.
138 return ERR_PTR(-ENAMETOOLONG
);
140 str
= kmalloc(len
+ 1, GFP_KERNEL
);
142 return ERR_PTR(-ENOMEM
);
144 memcpy(str
, *bufp
, len
);
152 /* Translate an inode field to kernel representation. */
153 static inline int audit_to_inode(struct audit_krule
*krule
,
154 struct audit_field
*f
)
156 if ((krule
->listnr
!= AUDIT_FILTER_EXIT
&&
157 krule
->listnr
!= AUDIT_FILTER_URING_EXIT
) ||
158 krule
->inode_f
|| krule
->watch
|| krule
->tree
||
159 (f
->op
!= Audit_equal
&& f
->op
!= Audit_not_equal
))
166 static __u32
*classes
[AUDIT_SYSCALL_CLASSES
];
168 int __init
audit_register_class(int class, unsigned *list
)
170 __u32
*p
= kcalloc(AUDIT_BITMASK_SIZE
, sizeof(__u32
), GFP_KERNEL
);
173 while (*list
!= ~0U) {
174 unsigned n
= *list
++;
175 if (n
>= AUDIT_BITMASK_SIZE
* 32 - AUDIT_SYSCALL_CLASSES
) {
179 p
[AUDIT_WORD(n
)] |= AUDIT_BIT(n
);
181 if (class >= AUDIT_SYSCALL_CLASSES
|| classes
[class]) {
189 int audit_match_class(int class, unsigned syscall
)
191 if (unlikely(syscall
>= AUDIT_BITMASK_SIZE
* 32))
193 if (unlikely(class >= AUDIT_SYSCALL_CLASSES
|| !classes
[class]))
195 return classes
[class][AUDIT_WORD(syscall
)] & AUDIT_BIT(syscall
);
198 #ifdef CONFIG_AUDITSYSCALL
199 static inline int audit_match_class_bits(int class, u32
*mask
)
203 if (classes
[class]) {
204 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
205 if (mask
[i
] & classes
[class][i
])
211 static int audit_match_signal(struct audit_entry
*entry
)
213 struct audit_field
*arch
= entry
->rule
.arch_f
;
216 /* When arch is unspecified, we must check both masks on biarch
217 * as syscall number alone is ambiguous. */
218 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
220 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
224 switch(audit_classify_arch(arch
->val
)) {
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
228 case 1: /* 32bit on biarch */
229 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
237 /* Common user-space to kernel rule translation. */
238 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule_data
*rule
)
241 struct audit_entry
*entry
;
245 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
249 #ifdef CONFIG_AUDITSYSCALL
250 case AUDIT_FILTER_ENTRY
:
251 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
253 case AUDIT_FILTER_EXIT
:
254 case AUDIT_FILTER_URING_EXIT
:
255 case AUDIT_FILTER_TASK
:
257 case AUDIT_FILTER_USER
:
258 case AUDIT_FILTER_EXCLUDE
:
259 case AUDIT_FILTER_FS
:
262 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
263 pr_err("AUDIT_POSSIBLE is deprecated\n");
266 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
268 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
272 entry
= audit_init_entry(rule
->field_count
);
276 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
277 entry
->rule
.listnr
= listnr
;
278 entry
->rule
.action
= rule
->action
;
279 entry
->rule
.field_count
= rule
->field_count
;
281 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
282 entry
->rule
.mask
[i
] = rule
->mask
[i
];
284 for (i
= 0; i
< AUDIT_SYSCALL_CLASSES
; i
++) {
285 int bit
= AUDIT_BITMASK_SIZE
* 32 - i
- 1;
286 __u32
*p
= &entry
->rule
.mask
[AUDIT_WORD(bit
)];
289 if (!(*p
& AUDIT_BIT(bit
)))
291 *p
&= ~AUDIT_BIT(bit
);
295 for (j
= 0; j
< AUDIT_BITMASK_SIZE
; j
++)
296 entry
->rule
.mask
[j
] |= class[j
];
306 static u32 audit_ops
[] =
308 [Audit_equal
] = AUDIT_EQUAL
,
309 [Audit_not_equal
] = AUDIT_NOT_EQUAL
,
310 [Audit_bitmask
] = AUDIT_BIT_MASK
,
311 [Audit_bittest
] = AUDIT_BIT_TEST
,
312 [Audit_lt
] = AUDIT_LESS_THAN
,
313 [Audit_gt
] = AUDIT_GREATER_THAN
,
314 [Audit_le
] = AUDIT_LESS_THAN_OR_EQUAL
,
315 [Audit_ge
] = AUDIT_GREATER_THAN_OR_EQUAL
,
318 static u32
audit_to_op(u32 op
)
321 for (n
= Audit_equal
; n
< Audit_bad
&& audit_ops
[n
] != op
; n
++)
326 /* check if an audit field is valid */
327 static int audit_field_valid(struct audit_entry
*entry
, struct audit_field
*f
)
331 if (entry
->rule
.listnr
!= AUDIT_FILTER_EXCLUDE
&&
332 entry
->rule
.listnr
!= AUDIT_FILTER_USER
)
336 if (entry
->rule
.listnr
!= AUDIT_FILTER_FS
)
340 if (entry
->rule
.listnr
== AUDIT_FILTER_URING_EXIT
)
345 switch (entry
->rule
.listnr
) {
346 case AUDIT_FILTER_FS
:
349 case AUDIT_FILTERKEY
:
356 /* Check for valid field type and op */
362 case AUDIT_PERS
: /* <uapi/linux/personality.h> */
364 /* all ops are valid */
384 case AUDIT_SESSIONID
:
387 case AUDIT_OBJ_LEV_LOW
:
388 case AUDIT_OBJ_LEV_HIGH
:
389 case AUDIT_SADDR_FAM
:
390 /* bit ops are only useful on syscall args */
391 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
394 case AUDIT_SUBJ_USER
:
395 case AUDIT_SUBJ_ROLE
:
396 case AUDIT_SUBJ_TYPE
:
402 case AUDIT_FILTERKEY
:
403 case AUDIT_LOGINUID_SET
:
408 case AUDIT_FIELD_COMPARE
:
410 /* only equal and not equal valid ops */
411 if (f
->op
!= Audit_not_equal
&& f
->op
!= Audit_equal
)
415 /* field not recognized */
419 /* Check for select valid field values */
421 case AUDIT_LOGINUID_SET
:
422 if ((f
->val
!= 0) && (f
->val
!= 1))
430 if (f
->val
& ~S_IFMT
)
433 case AUDIT_FIELD_COMPARE
:
434 if (f
->val
> AUDIT_MAX_FIELD_COMPARE
)
437 case AUDIT_SADDR_FAM
:
438 if (f
->val
>= AF_MAX
)
448 /* Translate struct audit_rule_data to kernel's rule representation. */
449 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
453 struct audit_entry
*entry
;
455 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
458 struct audit_fsnotify_mark
*audit_mark
;
460 entry
= audit_to_entry_common(data
);
465 for (i
= 0; i
< data
->field_count
; i
++) {
466 struct audit_field
*f
= &entry
->rule
.fields
[i
];
471 f
->op
= audit_to_op(data
->fieldflags
[i
]);
472 if (f
->op
== Audit_bad
)
475 f
->type
= data
->fields
[i
];
476 f_val
= data
->values
[i
];
478 /* Support legacy tests for a valid loginuid */
479 if ((f
->type
== AUDIT_LOGINUID
) && (f_val
== AUDIT_UID_UNSET
)) {
480 f
->type
= AUDIT_LOGINUID_SET
;
482 entry
->rule
.pflags
|= AUDIT_LOGINUID_LEGACY
;
485 err
= audit_field_valid(entry
, f
);
497 f
->uid
= make_kuid(current_user_ns(), f_val
);
498 if (!uid_valid(f
->uid
))
506 f
->gid
= make_kgid(current_user_ns(), f_val
);
507 if (!gid_valid(f
->gid
))
512 entry
->rule
.arch_f
= f
;
514 case AUDIT_SUBJ_USER
:
515 case AUDIT_SUBJ_ROLE
:
516 case AUDIT_SUBJ_TYPE
:
522 case AUDIT_OBJ_LEV_LOW
:
523 case AUDIT_OBJ_LEV_HIGH
:
524 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
529 entry
->rule
.buflen
+= f_val
;
531 err
= security_audit_rule_init(f
->type
, f
->op
, str
,
532 (void **)&f
->lsm_rule
);
533 /* Keep currently invalid fields around in case they
534 * become valid after a policy reload. */
535 if (err
== -EINVAL
) {
536 pr_warn("audit rule for LSM \'%s\' is invalid\n",
543 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
548 err
= audit_to_watch(&entry
->rule
, str
, f_val
, f
->op
);
553 entry
->rule
.buflen
+= f_val
;
556 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
561 err
= audit_make_tree(&entry
->rule
, str
, f
->op
);
565 entry
->rule
.buflen
+= f_val
;
569 err
= audit_to_inode(&entry
->rule
, f
);
573 case AUDIT_FILTERKEY
:
574 if (entry
->rule
.filterkey
|| f_val
> AUDIT_MAX_KEY_LEN
)
576 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
581 entry
->rule
.buflen
+= f_val
;
582 entry
->rule
.filterkey
= str
;
585 if (entry
->rule
.exe
|| f_val
> PATH_MAX
)
587 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
592 audit_mark
= audit_alloc_mark(&entry
->rule
, str
, f_val
);
593 if (IS_ERR(audit_mark
)) {
595 err
= PTR_ERR(audit_mark
);
598 entry
->rule
.buflen
+= f_val
;
599 entry
->rule
.exe
= audit_mark
;
607 if (entry
->rule
.inode_f
&& entry
->rule
.inode_f
->op
== Audit_not_equal
)
608 entry
->rule
.inode_f
= NULL
;
614 if (entry
->rule
.tree
)
615 audit_put_tree(entry
->rule
.tree
); /* that's the temporary one */
617 audit_remove_mark(entry
->rule
.exe
); /* that's the template one */
618 audit_free_rule(entry
);
622 /* Pack a filter field's string representation into data block. */
623 static inline size_t audit_pack_string(void **bufp
, const char *str
)
625 size_t len
= strlen(str
);
627 memcpy(*bufp
, str
, len
);
633 /* Translate kernel rule representation to struct audit_rule_data. */
634 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
636 struct audit_rule_data
*data
;
640 data
= kmalloc(struct_size(data
, buf
, krule
->buflen
), GFP_KERNEL
);
643 memset(data
, 0, sizeof(*data
));
645 data
->flags
= krule
->flags
| krule
->listnr
;
646 data
->action
= krule
->action
;
647 data
->field_count
= krule
->field_count
;
649 for (i
= 0; i
< data
->field_count
; i
++) {
650 struct audit_field
*f
= &krule
->fields
[i
];
652 data
->fields
[i
] = f
->type
;
653 data
->fieldflags
[i
] = audit_ops
[f
->op
];
655 case AUDIT_SUBJ_USER
:
656 case AUDIT_SUBJ_ROLE
:
657 case AUDIT_SUBJ_TYPE
:
663 case AUDIT_OBJ_LEV_LOW
:
664 case AUDIT_OBJ_LEV_HIGH
:
665 data
->buflen
+= data
->values
[i
] =
666 audit_pack_string(&bufp
, f
->lsm_str
);
669 data
->buflen
+= data
->values
[i
] =
670 audit_pack_string(&bufp
,
671 audit_watch_path(krule
->watch
));
674 data
->buflen
+= data
->values
[i
] =
675 audit_pack_string(&bufp
,
676 audit_tree_path(krule
->tree
));
678 case AUDIT_FILTERKEY
:
679 data
->buflen
+= data
->values
[i
] =
680 audit_pack_string(&bufp
, krule
->filterkey
);
683 data
->buflen
+= data
->values
[i
] =
684 audit_pack_string(&bufp
, audit_mark_path(krule
->exe
));
686 case AUDIT_LOGINUID_SET
:
687 if (krule
->pflags
& AUDIT_LOGINUID_LEGACY
&& !f
->val
) {
688 data
->fields
[i
] = AUDIT_LOGINUID
;
689 data
->values
[i
] = AUDIT_UID_UNSET
;
692 fallthrough
; /* if set */
694 data
->values
[i
] = f
->val
;
697 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
702 /* Compare two rules in kernel format. Considered success if rules
704 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
708 if (a
->flags
!= b
->flags
||
709 a
->pflags
!= b
->pflags
||
710 a
->listnr
!= b
->listnr
||
711 a
->action
!= b
->action
||
712 a
->field_count
!= b
->field_count
)
715 for (i
= 0; i
< a
->field_count
; i
++) {
716 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
717 a
->fields
[i
].op
!= b
->fields
[i
].op
)
720 switch(a
->fields
[i
].type
) {
721 case AUDIT_SUBJ_USER
:
722 case AUDIT_SUBJ_ROLE
:
723 case AUDIT_SUBJ_TYPE
:
729 case AUDIT_OBJ_LEV_LOW
:
730 case AUDIT_OBJ_LEV_HIGH
:
731 if (strcmp(a
->fields
[i
].lsm_str
, b
->fields
[i
].lsm_str
))
735 if (strcmp(audit_watch_path(a
->watch
),
736 audit_watch_path(b
->watch
)))
740 if (strcmp(audit_tree_path(a
->tree
),
741 audit_tree_path(b
->tree
)))
744 case AUDIT_FILTERKEY
:
745 /* both filterkeys exist based on above type compare */
746 if (strcmp(a
->filterkey
, b
->filterkey
))
750 /* both paths exist based on above type compare */
751 if (strcmp(audit_mark_path(a
->exe
),
752 audit_mark_path(b
->exe
)))
761 if (!uid_eq(a
->fields
[i
].uid
, b
->fields
[i
].uid
))
769 if (!gid_eq(a
->fields
[i
].gid
, b
->fields
[i
].gid
))
773 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
778 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
779 if (a
->mask
[i
] != b
->mask
[i
])
785 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
787 static inline int audit_dupe_lsm_field(struct audit_field
*df
,
788 struct audit_field
*sf
)
793 /* our own copy of lsm_str */
794 lsm_str
= kstrdup(sf
->lsm_str
, GFP_KERNEL
);
795 if (unlikely(!lsm_str
))
797 df
->lsm_str
= lsm_str
;
799 /* our own (refreshed) copy of lsm_rule */
800 ret
= security_audit_rule_init(df
->type
, df
->op
, df
->lsm_str
,
801 (void **)&df
->lsm_rule
);
802 /* Keep currently invalid fields around in case they
803 * become valid after a policy reload. */
804 if (ret
== -EINVAL
) {
805 pr_warn("audit rule for LSM \'%s\' is invalid\n",
813 /* Duplicate an audit rule. This will be a deep copy with the exception
814 * of the watch - that pointer is carried over. The LSM specific fields
815 * will be updated in the copy. The point is to be able to replace the old
816 * rule with the new rule in the filterlist, then free the old rule.
817 * The rlist element is undefined; list manipulations are handled apart from
818 * the initial copy. */
819 struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
)
821 u32 fcount
= old
->field_count
;
822 struct audit_entry
*entry
;
823 struct audit_krule
*new;
827 entry
= audit_init_entry(fcount
);
828 if (unlikely(!entry
))
829 return ERR_PTR(-ENOMEM
);
832 new->flags
= old
->flags
;
833 new->pflags
= old
->pflags
;
834 new->listnr
= old
->listnr
;
835 new->action
= old
->action
;
836 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
837 new->mask
[i
] = old
->mask
[i
];
838 new->prio
= old
->prio
;
839 new->buflen
= old
->buflen
;
840 new->inode_f
= old
->inode_f
;
841 new->field_count
= old
->field_count
;
844 * note that we are OK with not refcounting here; audit_match_tree()
845 * never dereferences tree and we can't get false positives there
846 * since we'd have to have rule gone from the list *and* removed
847 * before the chunks found by lookup had been allocated, i.e. before
848 * the beginning of list scan.
850 new->tree
= old
->tree
;
851 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
853 /* deep copy this information, updating the lsm_rule fields, because
854 * the originals will all be freed when the old rule is freed. */
855 for (i
= 0; i
< fcount
; i
++) {
856 switch (new->fields
[i
].type
) {
857 case AUDIT_SUBJ_USER
:
858 case AUDIT_SUBJ_ROLE
:
859 case AUDIT_SUBJ_TYPE
:
865 case AUDIT_OBJ_LEV_LOW
:
866 case AUDIT_OBJ_LEV_HIGH
:
867 err
= audit_dupe_lsm_field(&new->fields
[i
],
870 case AUDIT_FILTERKEY
:
871 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
878 err
= audit_dupe_exe(new, old
);
883 audit_remove_mark(new->exe
);
884 audit_free_rule(entry
);
890 audit_get_watch(old
->watch
);
891 new->watch
= old
->watch
;
897 /* Find an existing audit rule.
898 * Caller must hold audit_filter_mutex to prevent stale rule data. */
899 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
900 struct list_head
**p
)
902 struct audit_entry
*e
, *found
= NULL
;
903 struct list_head
*list
;
906 if (entry
->rule
.inode_f
) {
907 h
= audit_hash_ino(entry
->rule
.inode_f
->val
);
908 *p
= list
= &audit_inode_hash
[h
];
909 } else if (entry
->rule
.watch
) {
910 /* we don't know the inode number, so must walk entire hash */
911 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
912 list
= &audit_inode_hash
[h
];
913 list_for_each_entry(e
, list
, list
)
914 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
921 *p
= list
= &audit_filter_list
[entry
->rule
.listnr
];
924 list_for_each_entry(e
, list
, list
)
925 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
934 static u64 prio_low
= ~0ULL/2;
935 static u64 prio_high
= ~0ULL/2 - 1;
937 /* Add rule to given filterlist if not a duplicate. */
938 static inline int audit_add_rule(struct audit_entry
*entry
)
940 struct audit_entry
*e
;
941 struct audit_watch
*watch
= entry
->rule
.watch
;
942 struct audit_tree
*tree
= entry
->rule
.tree
;
943 struct list_head
*list
;
945 #ifdef CONFIG_AUDITSYSCALL
948 /* If any of these, don't count towards total */
949 switch(entry
->rule
.listnr
) {
950 case AUDIT_FILTER_USER
:
951 case AUDIT_FILTER_EXCLUDE
:
952 case AUDIT_FILTER_FS
:
957 mutex_lock(&audit_filter_mutex
);
958 e
= audit_find_rule(entry
, &list
);
960 mutex_unlock(&audit_filter_mutex
);
962 /* normally audit_add_tree_rule() will free it on failure */
964 audit_put_tree(tree
);
969 /* audit_filter_mutex is dropped and re-taken during this call */
970 err
= audit_add_watch(&entry
->rule
, &list
);
972 mutex_unlock(&audit_filter_mutex
);
974 * normally audit_add_tree_rule() will free it
978 audit_put_tree(tree
);
983 err
= audit_add_tree_rule(&entry
->rule
);
985 mutex_unlock(&audit_filter_mutex
);
990 entry
->rule
.prio
= ~0ULL;
991 if (entry
->rule
.listnr
== AUDIT_FILTER_EXIT
||
992 entry
->rule
.listnr
== AUDIT_FILTER_URING_EXIT
) {
993 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
)
994 entry
->rule
.prio
= ++prio_high
;
996 entry
->rule
.prio
= --prio_low
;
999 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
1000 list_add(&entry
->rule
.list
,
1001 &audit_rules_list
[entry
->rule
.listnr
]);
1002 list_add_rcu(&entry
->list
, list
);
1003 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
1005 list_add_tail(&entry
->rule
.list
,
1006 &audit_rules_list
[entry
->rule
.listnr
]);
1007 list_add_tail_rcu(&entry
->list
, list
);
1009 #ifdef CONFIG_AUDITSYSCALL
1013 if (!audit_match_signal(entry
))
1016 mutex_unlock(&audit_filter_mutex
);
1021 /* Remove an existing rule from filterlist. */
1022 int audit_del_rule(struct audit_entry
*entry
)
1024 struct audit_entry
*e
;
1025 struct audit_tree
*tree
= entry
->rule
.tree
;
1026 struct list_head
*list
;
1028 #ifdef CONFIG_AUDITSYSCALL
1031 /* If any of these, don't count towards total */
1032 switch(entry
->rule
.listnr
) {
1033 case AUDIT_FILTER_USER
:
1034 case AUDIT_FILTER_EXCLUDE
:
1035 case AUDIT_FILTER_FS
:
1040 mutex_lock(&audit_filter_mutex
);
1041 e
= audit_find_rule(entry
, &list
);
1048 audit_remove_watch_rule(&e
->rule
);
1051 audit_remove_tree_rule(&e
->rule
);
1054 audit_remove_mark_rule(&e
->rule
);
1056 #ifdef CONFIG_AUDITSYSCALL
1060 if (!audit_match_signal(entry
))
1064 list_del_rcu(&e
->list
);
1065 list_del(&e
->rule
.list
);
1066 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1069 mutex_unlock(&audit_filter_mutex
);
1072 audit_put_tree(tree
); /* that's the temporary one */
1077 /* List rules using struct audit_rule_data. */
1078 static void audit_list_rules(int seq
, struct sk_buff_head
*q
)
1080 struct sk_buff
*skb
;
1081 struct audit_krule
*r
;
1084 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1085 * iterator to sync with list writers. */
1086 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1087 list_for_each_entry(r
, &audit_rules_list
[i
], list
) {
1088 struct audit_rule_data
*data
;
1090 data
= audit_krule_to_data(r
);
1091 if (unlikely(!data
))
1093 skb
= audit_make_reply(seq
, AUDIT_LIST_RULES
, 0, 1,
1095 struct_size(data
, buf
, data
->buflen
));
1097 skb_queue_tail(q
, skb
);
1101 skb
= audit_make_reply(seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1103 skb_queue_tail(q
, skb
);
1106 /* Log rule additions and removals */
1107 static void audit_log_rule_change(char *action
, struct audit_krule
*rule
, int res
)
1109 struct audit_buffer
*ab
;
1114 ab
= audit_log_start(audit_context(), GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1117 audit_log_session_info(ab
);
1118 audit_log_task_context(ab
);
1119 audit_log_format(ab
, " op=%s", action
);
1120 audit_log_key(ab
, rule
->filterkey
);
1121 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1126 * audit_rule_change - apply all rules to the specified message type
1127 * @type: audit message type
1128 * @seq: netlink audit message sequence (serial) number
1129 * @data: payload data
1130 * @datasz: size of payload data
1132 int audit_rule_change(int type
, int seq
, void *data
, size_t datasz
)
1135 struct audit_entry
*entry
;
1138 case AUDIT_ADD_RULE
:
1139 entry
= audit_data_to_entry(data
, datasz
);
1141 return PTR_ERR(entry
);
1142 err
= audit_add_rule(entry
);
1143 audit_log_rule_change("add_rule", &entry
->rule
, !err
);
1145 case AUDIT_DEL_RULE
:
1146 entry
= audit_data_to_entry(data
, datasz
);
1148 return PTR_ERR(entry
);
1149 err
= audit_del_rule(entry
);
1150 audit_log_rule_change("remove_rule", &entry
->rule
, !err
);
1157 if (err
|| type
== AUDIT_DEL_RULE
) {
1158 if (entry
->rule
.exe
)
1159 audit_remove_mark(entry
->rule
.exe
);
1160 audit_free_rule(entry
);
1167 * audit_list_rules_send - list the audit rules
1168 * @request_skb: skb of request we are replying to (used to target the reply)
1169 * @seq: netlink audit message sequence (serial) number
1171 int audit_list_rules_send(struct sk_buff
*request_skb
, int seq
)
1173 struct task_struct
*tsk
;
1174 struct audit_netlink_list
*dest
;
1176 /* We can't just spew out the rules here because we might fill
1177 * the available socket buffer space and deadlock waiting for
1178 * auditctl to read from it... which isn't ever going to
1179 * happen if we're actually running in the context of auditctl
1180 * trying to _send_ the stuff */
1182 dest
= kmalloc(sizeof(*dest
), GFP_KERNEL
);
1185 dest
->net
= get_net(sock_net(NETLINK_CB(request_skb
).sk
));
1186 dest
->portid
= NETLINK_CB(request_skb
).portid
;
1187 skb_queue_head_init(&dest
->q
);
1189 mutex_lock(&audit_filter_mutex
);
1190 audit_list_rules(seq
, &dest
->q
);
1191 mutex_unlock(&audit_filter_mutex
);
1193 tsk
= kthread_run(audit_send_list_thread
, dest
, "audit_send_list");
1195 skb_queue_purge(&dest
->q
);
1198 return PTR_ERR(tsk
);
1204 int audit_comparator(u32 left
, u32 op
, u32 right
)
1208 return (left
== right
);
1209 case Audit_not_equal
:
1210 return (left
!= right
);
1212 return (left
< right
);
1214 return (left
<= right
);
1216 return (left
> right
);
1218 return (left
>= right
);
1220 return (left
& right
);
1222 return ((left
& right
) == right
);
1228 int audit_uid_comparator(kuid_t left
, u32 op
, kuid_t right
)
1232 return uid_eq(left
, right
);
1233 case Audit_not_equal
:
1234 return !uid_eq(left
, right
);
1236 return uid_lt(left
, right
);
1238 return uid_lte(left
, right
);
1240 return uid_gt(left
, right
);
1242 return uid_gte(left
, right
);
1250 int audit_gid_comparator(kgid_t left
, u32 op
, kgid_t right
)
1254 return gid_eq(left
, right
);
1255 case Audit_not_equal
:
1256 return !gid_eq(left
, right
);
1258 return gid_lt(left
, right
);
1260 return gid_lte(left
, right
);
1262 return gid_gt(left
, right
);
1264 return gid_gte(left
, right
);
1273 * parent_len - find the length of the parent portion of a pathname
1274 * @path: pathname of which to determine length
1276 int parent_len(const char *path
)
1281 plen
= strlen(path
);
1286 /* disregard trailing slashes */
1287 p
= path
+ plen
- 1;
1288 while ((*p
== '/') && (p
> path
))
1291 /* walk backward until we find the next slash or hit beginning */
1292 while ((*p
!= '/') && (p
> path
))
1295 /* did we find a slash? Then increment to include it in path */
1303 * audit_compare_dname_path - compare given dentry name with last component in
1304 * given path. Return of 0 indicates a match.
1305 * @dname: dentry name that we're comparing
1306 * @path: full pathname that we're comparing
1307 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1308 * here indicates that we must compute this value.
1310 int audit_compare_dname_path(const struct qstr
*dname
, const char *path
, int parentlen
)
1316 pathlen
= strlen(path
);
1320 parentlen
= parentlen
== AUDIT_NAME_FULL
? parent_len(path
) : parentlen
;
1321 if (pathlen
- parentlen
!= dlen
)
1324 p
= path
+ parentlen
;
1326 return strncmp(p
, dname
->name
, dlen
);
1329 int audit_filter(int msgtype
, unsigned int listtype
)
1331 struct audit_entry
*e
;
1332 int ret
= 1; /* Audit by default */
1335 list_for_each_entry_rcu(e
, &audit_filter_list
[listtype
], list
) {
1338 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1339 struct audit_field
*f
= &e
->rule
.fields
[i
];
1345 pid
= task_pid_nr(current
);
1346 result
= audit_comparator(pid
, f
->op
, f
->val
);
1349 result
= audit_uid_comparator(current_uid(), f
->op
, f
->uid
);
1352 result
= audit_gid_comparator(current_gid(), f
->op
, f
->gid
);
1354 case AUDIT_LOGINUID
:
1355 result
= audit_uid_comparator(audit_get_loginuid(current
),
1358 case AUDIT_LOGINUID_SET
:
1359 result
= audit_comparator(audit_loginuid_set(current
),
1363 result
= audit_comparator(msgtype
, f
->op
, f
->val
);
1365 case AUDIT_SUBJ_USER
:
1366 case AUDIT_SUBJ_ROLE
:
1367 case AUDIT_SUBJ_TYPE
:
1368 case AUDIT_SUBJ_SEN
:
1369 case AUDIT_SUBJ_CLR
:
1371 security_current_getsecid_subj(&sid
);
1372 result
= security_audit_rule_match(sid
,
1373 f
->type
, f
->op
, f
->lsm_rule
);
1377 result
= audit_exe_compare(current
, e
->rule
.exe
);
1378 if (f
->op
== Audit_not_equal
)
1382 goto unlock_and_return
;
1384 if (result
< 0) /* error */
1385 goto unlock_and_return
;
1390 if (e
->rule
.action
== AUDIT_NEVER
|| listtype
== AUDIT_FILTER_EXCLUDE
)
1400 static int update_lsm_rule(struct audit_krule
*r
)
1402 struct audit_entry
*entry
= container_of(r
, struct audit_entry
, rule
);
1403 struct audit_entry
*nentry
;
1406 if (!security_audit_rule_known(r
))
1409 nentry
= audit_dupe_rule(r
);
1410 if (entry
->rule
.exe
)
1411 audit_remove_mark(entry
->rule
.exe
);
1412 if (IS_ERR(nentry
)) {
1413 /* save the first error encountered for the
1415 err
= PTR_ERR(nentry
);
1416 audit_panic("error updating LSM filters");
1418 list_del(&r
->rlist
);
1419 list_del_rcu(&entry
->list
);
1422 if (r
->watch
|| r
->tree
)
1423 list_replace_init(&r
->rlist
, &nentry
->rule
.rlist
);
1424 list_replace_rcu(&entry
->list
, &nentry
->list
);
1425 list_replace(&r
->list
, &nentry
->rule
.list
);
1427 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1432 /* This function will re-initialize the lsm_rule field of all applicable rules.
1433 * It will traverse the filter lists serarching for rules that contain LSM
1434 * specific filter fields. When such a rule is found, it is copied, the
1435 * LSM field is re-initialized, and the old rule is replaced with the
1437 int audit_update_lsm_rules(void)
1439 struct audit_krule
*r
, *n
;
1442 /* audit_filter_mutex synchronizes the writers */
1443 mutex_lock(&audit_filter_mutex
);
1445 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1446 list_for_each_entry_safe(r
, n
, &audit_rules_list
[i
], list
) {
1447 int res
= update_lsm_rule(r
);
1452 mutex_unlock(&audit_filter_mutex
);