1 /* audit.c -- Auditing support
2 * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
3 * System-call specific features have moved to auditsc.c
5 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * Written by Rickard E. (Rik) Faith <faith@redhat.com>
24 * Goals: 1) Integrate fully with Security Modules.
25 * 2) Minimal run-time overhead:
26 * a) Minimal when syscall auditing is disabled (audit_enable=0).
27 * b) Small when syscall auditing is enabled and no audit record
28 * is generated (defer as much work as possible to record
30 * i) context is allocated,
31 * ii) names from getname are stored without a copy, and
32 * iii) inode information stored from path_lookup.
33 * 3) Ability to disable syscall auditing at boot time (audit=0).
34 * 4) Usable by other parts of the kernel (if audit_log* is called,
35 * then a syscall record will be generated automatically for the
37 * 5) Netlink interface to user-space.
38 * 6) Support low-overhead kernel-based filtering to minimize the
39 * information that must be passed to user-space.
41 * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
44 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46 #include <linux/file.h>
47 #include <linux/init.h>
48 #include <linux/types.h>
49 #include <linux/atomic.h>
51 #include <linux/export.h>
52 #include <linux/slab.h>
53 #include <linux/err.h>
54 #include <linux/kthread.h>
55 #include <linux/kernel.h>
56 #include <linux/syscalls.h>
57 #include <linux/spinlock.h>
58 #include <linux/rcupdate.h>
59 #include <linux/mutex.h>
60 #include <linux/gfp.h>
62 #include <linux/audit.h>
65 #include <net/netlink.h>
66 #include <linux/skbuff.h>
67 #ifdef CONFIG_SECURITY
68 #include <linux/security.h>
70 #include <linux/freezer.h>
71 #include <linux/pid_namespace.h>
72 #include <net/netns/generic.h>
76 /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
77 * (Initialization happens after skb_init is called.) */
78 #define AUDIT_DISABLED -1
79 #define AUDIT_UNINITIALIZED 0
80 #define AUDIT_INITIALIZED 1
81 static int audit_initialized
;
85 #define AUDIT_LOCKED 2
87 u32 audit_ever_enabled
;
89 EXPORT_SYMBOL_GPL(audit_enabled
);
91 /* Default state when kernel boots without any parameters. */
92 static u32 audit_default
;
94 /* If auditing cannot proceed, audit_failure selects what happens. */
95 static u32 audit_failure
= AUDIT_FAIL_PRINTK
;
97 /* private audit network namespace index */
98 static unsigned int audit_net_id
;
101 * struct audit_net - audit private network namespace data
102 * @sk: communication socket
109 * struct auditd_connection - kernel/auditd connection state
111 * @portid: netlink portid
112 * @net: the associated network namespace
113 * @lock: spinlock to protect write access
116 * This struct is RCU protected; you must either hold the RCU lock for reading
117 * or the included spinlock for writing.
119 static struct auditd_connection
{
126 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
127 * to that number per second. This prevents DoS attacks, but results in
128 * audit records being dropped. */
129 static u32 audit_rate_limit
;
131 /* Number of outstanding audit_buffers allowed.
132 * When set to zero, this means unlimited. */
133 static u32 audit_backlog_limit
= 64;
134 #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
135 static u32 audit_backlog_wait_time
= AUDIT_BACKLOG_WAIT_TIME
;
137 /* The identity of the user shutting down the audit system. */
138 kuid_t audit_sig_uid
= INVALID_UID
;
139 pid_t audit_sig_pid
= -1;
140 u32 audit_sig_sid
= 0;
142 /* Records can be lost in several ways:
143 0) [suppressed in audit_alloc]
144 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
145 2) out of memory in audit_log_move [alloc_skb]
146 3) suppressed due to audit_rate_limit
147 4) suppressed due to audit_backlog_limit
149 static atomic_t audit_lost
= ATOMIC_INIT(0);
151 /* Hash for inode-based rules */
152 struct list_head audit_inode_hash
[AUDIT_INODE_BUCKETS
];
154 /* The audit_freelist is a list of pre-allocated audit buffers (if more
155 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
156 * being placed on the freelist). */
157 static DEFINE_SPINLOCK(audit_freelist_lock
);
158 static int audit_freelist_count
;
159 static LIST_HEAD(audit_freelist
);
161 /* queue msgs to send via kauditd_task */
162 static struct sk_buff_head audit_queue
;
163 static void kauditd_hold_skb(struct sk_buff
*skb
);
164 /* queue msgs due to temporary unicast send problems */
165 static struct sk_buff_head audit_retry_queue
;
166 /* queue msgs waiting for new auditd connection */
167 static struct sk_buff_head audit_hold_queue
;
169 /* queue servicing thread */
170 static struct task_struct
*kauditd_task
;
171 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait
);
173 /* waitqueue for callers who are blocked on the audit backlog */
174 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait
);
176 static struct audit_features af
= {.vers
= AUDIT_FEATURE_VERSION
,
181 static char *audit_feature_names
[2] = {
182 "only_unset_loginuid",
183 "loginuid_immutable",
187 /* Serialize requests from userspace. */
188 DEFINE_MUTEX(audit_cmd_mutex
);
190 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
191 * audit records. Since printk uses a 1024 byte buffer, this buffer
192 * should be at least that large. */
193 #define AUDIT_BUFSIZ 1024
195 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
196 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
197 #define AUDIT_MAXFREE (2*NR_CPUS)
199 /* The audit_buffer is used when formatting an audit record. The caller
200 * locks briefly to get the record off the freelist or to allocate the
201 * buffer, and locks briefly to send the buffer to the netlink layer or
202 * to place it on a transmit queue. Multiple audit_buffers can be in
203 * use simultaneously. */
204 struct audit_buffer
{
205 struct list_head list
;
206 struct sk_buff
*skb
; /* formatted skb ready to send */
207 struct audit_context
*ctx
; /* NULL or associated context */
218 * auditd_test_task - Check to see if a given task is an audit daemon
219 * @task: the task to check
222 * Return 1 if the task is a registered audit daemon, 0 otherwise.
224 int auditd_test_task(const struct task_struct
*task
)
229 rc
= (auditd_conn
.pid
&& task
->tgid
== auditd_conn
.pid
? 1 : 0);
236 * audit_get_sk - Return the audit socket for the given network namespace
237 * @net: the destination network namespace
240 * Returns the sock pointer if valid, NULL otherwise. The caller must ensure
241 * that a reference is held for the network namespace while the sock is in use.
243 static struct sock
*audit_get_sk(const struct net
*net
)
245 struct audit_net
*aunet
;
250 aunet
= net_generic(net
, audit_net_id
);
254 static void audit_set_portid(struct audit_buffer
*ab
, __u32 portid
)
257 struct nlmsghdr
*nlh
= nlmsg_hdr(ab
->skb
);
258 nlh
->nlmsg_pid
= portid
;
262 void audit_panic(const char *message
)
264 switch (audit_failure
) {
265 case AUDIT_FAIL_SILENT
:
267 case AUDIT_FAIL_PRINTK
:
268 if (printk_ratelimit())
269 pr_err("%s\n", message
);
271 case AUDIT_FAIL_PANIC
:
272 panic("audit: %s\n", message
);
277 static inline int audit_rate_check(void)
279 static unsigned long last_check
= 0;
280 static int messages
= 0;
281 static DEFINE_SPINLOCK(lock
);
284 unsigned long elapsed
;
287 if (!audit_rate_limit
) return 1;
289 spin_lock_irqsave(&lock
, flags
);
290 if (++messages
< audit_rate_limit
) {
294 elapsed
= now
- last_check
;
301 spin_unlock_irqrestore(&lock
, flags
);
307 * audit_log_lost - conditionally log lost audit message event
308 * @message: the message stating reason for lost audit message
310 * Emit at least 1 message per second, even if audit_rate_check is
312 * Always increment the lost messages counter.
314 void audit_log_lost(const char *message
)
316 static unsigned long last_msg
= 0;
317 static DEFINE_SPINLOCK(lock
);
322 atomic_inc(&audit_lost
);
324 print
= (audit_failure
== AUDIT_FAIL_PANIC
|| !audit_rate_limit
);
327 spin_lock_irqsave(&lock
, flags
);
329 if (now
- last_msg
> HZ
) {
333 spin_unlock_irqrestore(&lock
, flags
);
337 if (printk_ratelimit())
338 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
339 atomic_read(&audit_lost
),
341 audit_backlog_limit
);
342 audit_panic(message
);
346 static int audit_log_config_change(char *function_name
, u32
new, u32 old
,
349 struct audit_buffer
*ab
;
352 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
355 audit_log_format(ab
, "%s=%u old=%u", function_name
, new, old
);
356 audit_log_session_info(ab
);
357 rc
= audit_log_task_context(ab
);
359 allow_changes
= 0; /* Something weird, deny request */
360 audit_log_format(ab
, " res=%d", allow_changes
);
365 static int audit_do_config_change(char *function_name
, u32
*to_change
, u32
new)
367 int allow_changes
, rc
= 0;
368 u32 old
= *to_change
;
370 /* check if we are locked */
371 if (audit_enabled
== AUDIT_LOCKED
)
376 if (audit_enabled
!= AUDIT_OFF
) {
377 rc
= audit_log_config_change(function_name
, new, old
, allow_changes
);
382 /* If we are allowed, make the change */
383 if (allow_changes
== 1)
385 /* Not allowed, update reason */
391 static int audit_set_rate_limit(u32 limit
)
393 return audit_do_config_change("audit_rate_limit", &audit_rate_limit
, limit
);
396 static int audit_set_backlog_limit(u32 limit
)
398 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit
, limit
);
401 static int audit_set_backlog_wait_time(u32 timeout
)
403 return audit_do_config_change("audit_backlog_wait_time",
404 &audit_backlog_wait_time
, timeout
);
407 static int audit_set_enabled(u32 state
)
410 if (state
> AUDIT_LOCKED
)
413 rc
= audit_do_config_change("audit_enabled", &audit_enabled
, state
);
415 audit_ever_enabled
|= !!state
;
420 static int audit_set_failure(u32 state
)
422 if (state
!= AUDIT_FAIL_SILENT
423 && state
!= AUDIT_FAIL_PRINTK
424 && state
!= AUDIT_FAIL_PANIC
)
427 return audit_do_config_change("audit_failure", &audit_failure
, state
);
431 * auditd_set - Set/Reset the auditd connection state
433 * @portid: auditd netlink portid
434 * @net: auditd network namespace pointer
437 * This function will obtain and drop network namespace references as
440 static void auditd_set(int pid
, u32 portid
, struct net
*net
)
444 spin_lock_irqsave(&auditd_conn
.lock
, flags
);
445 auditd_conn
.pid
= pid
;
446 auditd_conn
.portid
= portid
;
448 put_net(auditd_conn
.net
);
450 auditd_conn
.net
= get_net(net
);
452 auditd_conn
.net
= NULL
;
453 spin_unlock_irqrestore(&auditd_conn
.lock
, flags
);
457 * auditd_reset - Disconnect the auditd connection
460 * Break the auditd/kauditd connection and move all the queued records into the
461 * hold queue in case auditd reconnects.
463 static void auditd_reset(void)
467 /* if it isn't already broken, break the connection */
470 auditd_set(0, 0, NULL
);
473 /* flush all of the main and retry queues to the hold queue */
474 while ((skb
= skb_dequeue(&audit_retry_queue
)))
475 kauditd_hold_skb(skb
);
476 while ((skb
= skb_dequeue(&audit_queue
)))
477 kauditd_hold_skb(skb
);
481 * kauditd_print_skb - Print the audit record to the ring buffer
484 * Whatever the reason, this packet may not make it to the auditd connection
485 * so write it via printk so the information isn't completely lost.
487 static void kauditd_printk_skb(struct sk_buff
*skb
)
489 struct nlmsghdr
*nlh
= nlmsg_hdr(skb
);
490 char *data
= nlmsg_data(nlh
);
492 if (nlh
->nlmsg_type
!= AUDIT_EOE
&& printk_ratelimit())
493 pr_notice("type=%d %s\n", nlh
->nlmsg_type
, data
);
497 * kauditd_rehold_skb - Handle a audit record send failure in the hold queue
501 * This should only be used by the kauditd_thread when it fails to flush the
504 static void kauditd_rehold_skb(struct sk_buff
*skb
)
506 /* put the record back in the queue at the same place */
507 skb_queue_head(&audit_hold_queue
, skb
);
509 /* fail the auditd connection */
514 * kauditd_hold_skb - Queue an audit record, waiting for auditd
518 * Queue the audit record, waiting for an instance of auditd. When this
519 * function is called we haven't given up yet on sending the record, but things
520 * are not looking good. The first thing we want to do is try to write the
521 * record via printk and then see if we want to try and hold on to the record
522 * and queue it, if we have room. If we want to hold on to the record, but we
523 * don't have room, record a record lost message.
525 static void kauditd_hold_skb(struct sk_buff
*skb
)
527 /* at this point it is uncertain if we will ever send this to auditd so
528 * try to send the message via printk before we go any further */
529 kauditd_printk_skb(skb
);
531 /* can we just silently drop the message? */
532 if (!audit_default
) {
537 /* if we have room, queue the message */
538 if (!audit_backlog_limit
||
539 skb_queue_len(&audit_hold_queue
) < audit_backlog_limit
) {
540 skb_queue_tail(&audit_hold_queue
, skb
);
544 /* we have no other options - drop the message */
545 audit_log_lost("kauditd hold queue overflow");
548 /* fail the auditd connection */
553 * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
557 * Not as serious as kauditd_hold_skb() as we still have a connected auditd,
558 * but for some reason we are having problems sending it audit records so
559 * queue the given record and attempt to resend.
561 static void kauditd_retry_skb(struct sk_buff
*skb
)
563 /* NOTE: because records should only live in the retry queue for a
564 * short period of time, before either being sent or moved to the hold
565 * queue, we don't currently enforce a limit on this queue */
566 skb_queue_tail(&audit_retry_queue
, skb
);
570 * auditd_send_unicast_skb - Send a record via unicast to auditd
574 * Send a skb to the audit daemon, returns positive/zero values on success and
575 * negative values on failure; in all cases the skb will be consumed by this
576 * function. If the send results in -ECONNREFUSED the connection with auditd
577 * will be reset. This function may sleep so callers should not hold any locks
578 * where this would cause a problem.
580 static int auditd_send_unicast_skb(struct sk_buff
*skb
)
587 /* NOTE: we can't call netlink_unicast while in the RCU section so
588 * take a reference to the network namespace and grab local
589 * copies of the namespace, the sock, and the portid; the
590 * namespace and sock aren't going to go away while we hold a
591 * reference and if the portid does become invalid after the RCU
592 * section netlink_unicast() should safely return an error */
595 if (!auditd_conn
.pid
) {
600 net
= auditd_conn
.net
;
602 sk
= audit_get_sk(net
);
603 portid
= auditd_conn
.portid
;
606 rc
= netlink_unicast(sk
, skb
, portid
, 0);
614 if (rc
== -ECONNREFUSED
)
620 * kauditd_send_queue - Helper for kauditd_thread to flush skb queues
621 * @sk: the sending sock
622 * @portid: the netlink destination
623 * @queue: the skb queue to process
624 * @retry_limit: limit on number of netlink unicast failures
625 * @skb_hook: per-skb hook for additional processing
626 * @err_hook: hook called if the skb fails the netlink unicast send
629 * Run through the given queue and attempt to send the audit records to auditd,
630 * returns zero on success, negative values on failure. It is up to the caller
631 * to ensure that the @sk is valid for the duration of this function.
634 static int kauditd_send_queue(struct sock
*sk
, u32 portid
,
635 struct sk_buff_head
*queue
,
636 unsigned int retry_limit
,
637 void (*skb_hook
)(struct sk_buff
*skb
),
638 void (*err_hook
)(struct sk_buff
*skb
))
642 static unsigned int failed
= 0;
644 /* NOTE: kauditd_thread takes care of all our locking, we just use
645 * the netlink info passed to us (e.g. sk and portid) */
647 while ((skb
= skb_dequeue(queue
))) {
648 /* call the skb_hook for each skb we touch */
652 /* can we send to anyone via unicast? */
659 /* grab an extra skb reference in case of error */
661 rc
= netlink_unicast(sk
, skb
, portid
, 0);
663 /* fatal failure for our queue flush attempt? */
664 if (++failed
>= retry_limit
||
665 rc
== -ECONNREFUSED
|| rc
== -EPERM
) {
666 /* yes - error processing for the queue */
672 /* keep processing with the skb_hook */
675 /* no - requeue to preserve ordering */
676 skb_queue_head(queue
, skb
);
678 /* it worked - drop the extra reference and continue */
685 return (rc
>= 0 ? 0 : rc
);
689 * kauditd_send_multicast_skb - Send a record to any multicast listeners
693 * Write a multicast message to anyone listening in the initial network
694 * namespace. This function doesn't consume an skb as might be expected since
695 * it has to copy it anyways.
697 static void kauditd_send_multicast_skb(struct sk_buff
*skb
)
699 struct sk_buff
*copy
;
700 struct sock
*sock
= audit_get_sk(&init_net
);
701 struct nlmsghdr
*nlh
;
703 /* NOTE: we are not taking an additional reference for init_net since
704 * we don't have to worry about it going away */
706 if (!netlink_has_listeners(sock
, AUDIT_NLGRP_READLOG
))
710 * The seemingly wasteful skb_copy() rather than bumping the refcount
711 * using skb_get() is necessary because non-standard mods are made to
712 * the skb by the original kaudit unicast socket send routine. The
713 * existing auditd daemon assumes this breakage. Fixing this would
714 * require co-ordinating a change in the established protocol between
715 * the kaudit kernel subsystem and the auditd userspace code. There is
716 * no reason for new multicast clients to continue with this
719 copy
= skb_copy(skb
, GFP_KERNEL
);
722 nlh
= nlmsg_hdr(copy
);
723 nlh
->nlmsg_len
= skb
->len
;
725 nlmsg_multicast(sock
, copy
, 0, AUDIT_NLGRP_READLOG
, GFP_KERNEL
);
729 * kauditd_thread - Worker thread to send audit records to userspace
732 static int kauditd_thread(void *dummy
)
736 struct net
*net
= NULL
;
737 struct sock
*sk
= NULL
;
739 #define UNICAST_RETRIES 5
742 while (!kthread_should_stop()) {
743 /* NOTE: see the lock comments in auditd_send_unicast_skb() */
745 if (!auditd_conn
.pid
) {
749 net
= auditd_conn
.net
;
751 sk
= audit_get_sk(net
);
752 portid
= auditd_conn
.portid
;
755 /* attempt to flush the hold queue */
756 rc
= kauditd_send_queue(sk
, portid
,
757 &audit_hold_queue
, UNICAST_RETRIES
,
758 NULL
, kauditd_rehold_skb
);
764 /* attempt to flush the retry queue */
765 rc
= kauditd_send_queue(sk
, portid
,
766 &audit_retry_queue
, UNICAST_RETRIES
,
767 NULL
, kauditd_hold_skb
);
774 /* process the main queue - do the multicast send and attempt
775 * unicast, dump failed record sends to the retry queue; if
776 * sk == NULL due to previous failures we will just do the
777 * multicast send and move the record to the retry queue */
778 kauditd_send_queue(sk
, portid
, &audit_queue
, 1,
779 kauditd_send_multicast_skb
,
782 /* drop our netns reference, no auditd sends past this line */
789 /* we have processed all the queues so wake everyone */
790 wake_up(&audit_backlog_wait
);
792 /* NOTE: we want to wake up if there is anything on the queue,
793 * regardless of if an auditd is connected, as we need to
794 * do the multicast send and rotate records from the
795 * main queue to the retry/hold queues */
796 wait_event_freezable(kauditd_wait
,
797 (skb_queue_len(&audit_queue
) ? 1 : 0));
803 int audit_send_list(void *_dest
)
805 struct audit_netlink_list
*dest
= _dest
;
807 struct sock
*sk
= audit_get_sk(dest
->net
);
809 /* wait for parent to finish and send an ACK */
810 mutex_lock(&audit_cmd_mutex
);
811 mutex_unlock(&audit_cmd_mutex
);
813 while ((skb
= __skb_dequeue(&dest
->q
)) != NULL
)
814 netlink_unicast(sk
, skb
, dest
->portid
, 0);
822 struct sk_buff
*audit_make_reply(__u32 portid
, int seq
, int type
, int done
,
823 int multi
, const void *payload
, int size
)
826 struct nlmsghdr
*nlh
;
828 int flags
= multi
? NLM_F_MULTI
: 0;
829 int t
= done
? NLMSG_DONE
: type
;
831 skb
= nlmsg_new(size
, GFP_KERNEL
);
835 nlh
= nlmsg_put(skb
, portid
, seq
, t
, size
, flags
);
838 data
= nlmsg_data(nlh
);
839 memcpy(data
, payload
, size
);
847 static int audit_send_reply_thread(void *arg
)
849 struct audit_reply
*reply
= (struct audit_reply
*)arg
;
850 struct sock
*sk
= audit_get_sk(reply
->net
);
852 mutex_lock(&audit_cmd_mutex
);
853 mutex_unlock(&audit_cmd_mutex
);
855 /* Ignore failure. It'll only happen if the sender goes away,
856 because our timeout is set to infinite. */
857 netlink_unicast(sk
, reply
->skb
, reply
->portid
, 0);
864 * audit_send_reply - send an audit reply message via netlink
865 * @request_skb: skb of request we are replying to (used to target the reply)
866 * @seq: sequence number
867 * @type: audit message type
868 * @done: done (last) flag
869 * @multi: multi-part message flag
870 * @payload: payload data
871 * @size: payload size
873 * Allocates an skb, builds the netlink message, and sends it to the port id.
874 * No failure notifications.
876 static void audit_send_reply(struct sk_buff
*request_skb
, int seq
, int type
, int done
,
877 int multi
, const void *payload
, int size
)
879 u32 portid
= NETLINK_CB(request_skb
).portid
;
880 struct net
*net
= sock_net(NETLINK_CB(request_skb
).sk
);
882 struct task_struct
*tsk
;
883 struct audit_reply
*reply
= kmalloc(sizeof(struct audit_reply
),
889 skb
= audit_make_reply(portid
, seq
, type
, done
, multi
, payload
, size
);
893 reply
->net
= get_net(net
);
894 reply
->portid
= portid
;
897 tsk
= kthread_run(audit_send_reply_thread
, reply
, "audit_send_reply");
906 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
909 static int audit_netlink_ok(struct sk_buff
*skb
, u16 msg_type
)
913 /* Only support initial user namespace for now. */
915 * We return ECONNREFUSED because it tricks userspace into thinking
916 * that audit was not configured into the kernel. Lots of users
917 * configure their PAM stack (because that's what the distro does)
918 * to reject login if unable to send messages to audit. If we return
919 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
920 * configured in and will let login proceed. If we return EPERM
921 * userspace will reject all logins. This should be removed when we
922 * support non init namespaces!!
924 if (current_user_ns() != &init_user_ns
)
925 return -ECONNREFUSED
;
934 case AUDIT_GET_FEATURE
:
935 case AUDIT_SET_FEATURE
:
936 case AUDIT_LIST_RULES
:
939 case AUDIT_SIGNAL_INFO
:
943 case AUDIT_MAKE_EQUIV
:
944 /* Only support auditd and auditctl in initial pid namespace
946 if (task_active_pid_ns(current
) != &init_pid_ns
)
949 if (!netlink_capable(skb
, CAP_AUDIT_CONTROL
))
953 case AUDIT_FIRST_USER_MSG
... AUDIT_LAST_USER_MSG
:
954 case AUDIT_FIRST_USER_MSG2
... AUDIT_LAST_USER_MSG2
:
955 if (!netlink_capable(skb
, CAP_AUDIT_WRITE
))
958 default: /* bad msg */
965 static void audit_log_common_recv_msg(struct audit_buffer
**ab
, u16 msg_type
)
967 uid_t uid
= from_kuid(&init_user_ns
, current_uid());
968 pid_t pid
= task_tgid_nr(current
);
970 if (!audit_enabled
&& msg_type
!= AUDIT_USER_AVC
) {
975 *ab
= audit_log_start(NULL
, GFP_KERNEL
, msg_type
);
978 audit_log_format(*ab
, "pid=%d uid=%u", pid
, uid
);
979 audit_log_session_info(*ab
);
980 audit_log_task_context(*ab
);
983 int is_audit_feature_set(int i
)
985 return af
.features
& AUDIT_FEATURE_TO_MASK(i
);
989 static int audit_get_feature(struct sk_buff
*skb
)
993 seq
= nlmsg_hdr(skb
)->nlmsg_seq
;
995 audit_send_reply(skb
, seq
, AUDIT_GET_FEATURE
, 0, 0, &af
, sizeof(af
));
1000 static void audit_log_feature_change(int which
, u32 old_feature
, u32 new_feature
,
1001 u32 old_lock
, u32 new_lock
, int res
)
1003 struct audit_buffer
*ab
;
1005 if (audit_enabled
== AUDIT_OFF
)
1008 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_FEATURE_CHANGE
);
1009 audit_log_task_info(ab
, current
);
1010 audit_log_format(ab
, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
1011 audit_feature_names
[which
], !!old_feature
, !!new_feature
,
1012 !!old_lock
, !!new_lock
, res
);
1016 static int audit_set_feature(struct sk_buff
*skb
)
1018 struct audit_features
*uaf
;
1021 BUILD_BUG_ON(AUDIT_LAST_FEATURE
+ 1 > ARRAY_SIZE(audit_feature_names
));
1022 uaf
= nlmsg_data(nlmsg_hdr(skb
));
1024 /* if there is ever a version 2 we should handle that here */
1026 for (i
= 0; i
<= AUDIT_LAST_FEATURE
; i
++) {
1027 u32 feature
= AUDIT_FEATURE_TO_MASK(i
);
1028 u32 old_feature
, new_feature
, old_lock
, new_lock
;
1030 /* if we are not changing this feature, move along */
1031 if (!(feature
& uaf
->mask
))
1034 old_feature
= af
.features
& feature
;
1035 new_feature
= uaf
->features
& feature
;
1036 new_lock
= (uaf
->lock
| af
.lock
) & feature
;
1037 old_lock
= af
.lock
& feature
;
1039 /* are we changing a locked feature? */
1040 if (old_lock
&& (new_feature
!= old_feature
)) {
1041 audit_log_feature_change(i
, old_feature
, new_feature
,
1042 old_lock
, new_lock
, 0);
1046 /* nothing invalid, do the changes */
1047 for (i
= 0; i
<= AUDIT_LAST_FEATURE
; i
++) {
1048 u32 feature
= AUDIT_FEATURE_TO_MASK(i
);
1049 u32 old_feature
, new_feature
, old_lock
, new_lock
;
1051 /* if we are not changing this feature, move along */
1052 if (!(feature
& uaf
->mask
))
1055 old_feature
= af
.features
& feature
;
1056 new_feature
= uaf
->features
& feature
;
1057 old_lock
= af
.lock
& feature
;
1058 new_lock
= (uaf
->lock
| af
.lock
) & feature
;
1060 if (new_feature
!= old_feature
)
1061 audit_log_feature_change(i
, old_feature
, new_feature
,
1062 old_lock
, new_lock
, 1);
1065 af
.features
|= feature
;
1067 af
.features
&= ~feature
;
1068 af
.lock
|= new_lock
;
1074 static int audit_replace(pid_t pid
)
1076 struct sk_buff
*skb
;
1078 skb
= audit_make_reply(0, 0, AUDIT_REPLACE
, 0, 0, &pid
, sizeof(pid
));
1081 return auditd_send_unicast_skb(skb
);
1084 static int audit_receive_msg(struct sk_buff
*skb
, struct nlmsghdr
*nlh
)
1089 struct audit_buffer
*ab
;
1090 u16 msg_type
= nlh
->nlmsg_type
;
1091 struct audit_sig_info
*sig_data
;
1095 err
= audit_netlink_ok(skb
, msg_type
);
1099 seq
= nlh
->nlmsg_seq
;
1100 data
= nlmsg_data(nlh
);
1104 struct audit_status s
;
1105 memset(&s
, 0, sizeof(s
));
1106 s
.enabled
= audit_enabled
;
1107 s
.failure
= audit_failure
;
1109 s
.pid
= auditd_conn
.pid
;
1111 s
.rate_limit
= audit_rate_limit
;
1112 s
.backlog_limit
= audit_backlog_limit
;
1113 s
.lost
= atomic_read(&audit_lost
);
1114 s
.backlog
= skb_queue_len(&audit_queue
);
1115 s
.feature_bitmap
= AUDIT_FEATURE_BITMAP_ALL
;
1116 s
.backlog_wait_time
= audit_backlog_wait_time
;
1117 audit_send_reply(skb
, seq
, AUDIT_GET
, 0, 0, &s
, sizeof(s
));
1121 struct audit_status s
;
1122 memset(&s
, 0, sizeof(s
));
1123 /* guard against past and future API changes */
1124 memcpy(&s
, data
, min_t(size_t, sizeof(s
), nlmsg_len(nlh
)));
1125 if (s
.mask
& AUDIT_STATUS_ENABLED
) {
1126 err
= audit_set_enabled(s
.enabled
);
1130 if (s
.mask
& AUDIT_STATUS_FAILURE
) {
1131 err
= audit_set_failure(s
.failure
);
1135 if (s
.mask
& AUDIT_STATUS_PID
) {
1136 /* NOTE: we are using task_tgid_vnr() below because
1137 * the s.pid value is relative to the namespace
1138 * of the caller; at present this doesn't matter
1139 * much since you can really only run auditd
1140 * from the initial pid namespace, but something
1141 * to keep in mind if this changes */
1142 int new_pid
= s
.pid
;
1144 pid_t requesting_pid
= task_tgid_vnr(current
);
1146 /* test the auditd connection */
1147 audit_replace(requesting_pid
);
1150 auditd_pid
= auditd_conn
.pid
;
1151 /* only the current auditd can unregister itself */
1152 if ((!new_pid
) && (requesting_pid
!= auditd_pid
)) {
1154 audit_log_config_change("audit_pid", new_pid
,
1158 /* replacing a healthy auditd is not allowed */
1159 if (auditd_pid
&& new_pid
) {
1161 audit_log_config_change("audit_pid", new_pid
,
1167 if (audit_enabled
!= AUDIT_OFF
)
1168 audit_log_config_change("audit_pid", new_pid
,
1172 /* register a new auditd connection */
1174 NETLINK_CB(skb
).portid
,
1175 sock_net(NETLINK_CB(skb
).sk
));
1176 /* try to process any backlog */
1177 wake_up_interruptible(&kauditd_wait
);
1179 /* unregister the auditd connection */
1182 if (s
.mask
& AUDIT_STATUS_RATE_LIMIT
) {
1183 err
= audit_set_rate_limit(s
.rate_limit
);
1187 if (s
.mask
& AUDIT_STATUS_BACKLOG_LIMIT
) {
1188 err
= audit_set_backlog_limit(s
.backlog_limit
);
1192 if (s
.mask
& AUDIT_STATUS_BACKLOG_WAIT_TIME
) {
1193 if (sizeof(s
) > (size_t)nlh
->nlmsg_len
)
1195 if (s
.backlog_wait_time
> 10*AUDIT_BACKLOG_WAIT_TIME
)
1197 err
= audit_set_backlog_wait_time(s
.backlog_wait_time
);
1201 if (s
.mask
== AUDIT_STATUS_LOST
) {
1202 u32 lost
= atomic_xchg(&audit_lost
, 0);
1204 audit_log_config_change("lost", 0, lost
, 1);
1209 case AUDIT_GET_FEATURE
:
1210 err
= audit_get_feature(skb
);
1214 case AUDIT_SET_FEATURE
:
1215 err
= audit_set_feature(skb
);
1220 case AUDIT_FIRST_USER_MSG
... AUDIT_LAST_USER_MSG
:
1221 case AUDIT_FIRST_USER_MSG2
... AUDIT_LAST_USER_MSG2
:
1222 if (!audit_enabled
&& msg_type
!= AUDIT_USER_AVC
)
1225 err
= audit_filter(msg_type
, AUDIT_FILTER_USER
);
1226 if (err
== 1) { /* match or error */
1228 if (msg_type
== AUDIT_USER_TTY
) {
1229 err
= tty_audit_push();
1233 audit_log_common_recv_msg(&ab
, msg_type
);
1234 if (msg_type
!= AUDIT_USER_TTY
)
1235 audit_log_format(ab
, " msg='%.*s'",
1236 AUDIT_MESSAGE_TEXT_MAX
,
1241 audit_log_format(ab
, " data=");
1242 size
= nlmsg_len(nlh
);
1244 ((unsigned char *)data
)[size
- 1] == '\0')
1246 audit_log_n_untrustedstring(ab
, data
, size
);
1248 audit_set_portid(ab
, NETLINK_CB(skb
).portid
);
1252 case AUDIT_ADD_RULE
:
1253 case AUDIT_DEL_RULE
:
1254 if (nlmsg_len(nlh
) < sizeof(struct audit_rule_data
))
1256 if (audit_enabled
== AUDIT_LOCKED
) {
1257 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1258 audit_log_format(ab
, " audit_enabled=%d res=0", audit_enabled
);
1262 err
= audit_rule_change(msg_type
, NETLINK_CB(skb
).portid
,
1263 seq
, data
, nlmsg_len(nlh
));
1265 case AUDIT_LIST_RULES
:
1266 err
= audit_list_rules_send(skb
, seq
);
1270 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1271 audit_log_format(ab
, " op=trim res=1");
1274 case AUDIT_MAKE_EQUIV
: {
1277 size_t msglen
= nlmsg_len(nlh
);
1281 if (msglen
< 2 * sizeof(u32
))
1283 memcpy(sizes
, bufp
, 2 * sizeof(u32
));
1284 bufp
+= 2 * sizeof(u32
);
1285 msglen
-= 2 * sizeof(u32
);
1286 old
= audit_unpack_string(&bufp
, &msglen
, sizes
[0]);
1291 new = audit_unpack_string(&bufp
, &msglen
, sizes
[1]);
1297 /* OK, here comes... */
1298 err
= audit_tag_tree(old
, new);
1300 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1302 audit_log_format(ab
, " op=make_equiv old=");
1303 audit_log_untrustedstring(ab
, old
);
1304 audit_log_format(ab
, " new=");
1305 audit_log_untrustedstring(ab
, new);
1306 audit_log_format(ab
, " res=%d", !err
);
1312 case AUDIT_SIGNAL_INFO
:
1314 if (audit_sig_sid
) {
1315 err
= security_secid_to_secctx(audit_sig_sid
, &ctx
, &len
);
1319 sig_data
= kmalloc(sizeof(*sig_data
) + len
, GFP_KERNEL
);
1322 security_release_secctx(ctx
, len
);
1325 sig_data
->uid
= from_kuid(&init_user_ns
, audit_sig_uid
);
1326 sig_data
->pid
= audit_sig_pid
;
1327 if (audit_sig_sid
) {
1328 memcpy(sig_data
->ctx
, ctx
, len
);
1329 security_release_secctx(ctx
, len
);
1331 audit_send_reply(skb
, seq
, AUDIT_SIGNAL_INFO
, 0, 0,
1332 sig_data
, sizeof(*sig_data
) + len
);
1335 case AUDIT_TTY_GET
: {
1336 struct audit_tty_status s
;
1339 t
= READ_ONCE(current
->signal
->audit_tty
);
1340 s
.enabled
= t
& AUDIT_TTY_ENABLE
;
1341 s
.log_passwd
= !!(t
& AUDIT_TTY_LOG_PASSWD
);
1343 audit_send_reply(skb
, seq
, AUDIT_TTY_GET
, 0, 0, &s
, sizeof(s
));
1346 case AUDIT_TTY_SET
: {
1347 struct audit_tty_status s
, old
;
1348 struct audit_buffer
*ab
;
1351 memset(&s
, 0, sizeof(s
));
1352 /* guard against past and future API changes */
1353 memcpy(&s
, data
, min_t(size_t, sizeof(s
), nlmsg_len(nlh
)));
1354 /* check if new data is valid */
1355 if ((s
.enabled
!= 0 && s
.enabled
!= 1) ||
1356 (s
.log_passwd
!= 0 && s
.log_passwd
!= 1))
1360 t
= READ_ONCE(current
->signal
->audit_tty
);
1362 t
= s
.enabled
| (-s
.log_passwd
& AUDIT_TTY_LOG_PASSWD
);
1363 t
= xchg(¤t
->signal
->audit_tty
, t
);
1365 old
.enabled
= t
& AUDIT_TTY_ENABLE
;
1366 old
.log_passwd
= !!(t
& AUDIT_TTY_LOG_PASSWD
);
1368 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1369 audit_log_format(ab
, " op=tty_set old-enabled=%d new-enabled=%d"
1370 " old-log_passwd=%d new-log_passwd=%d res=%d",
1371 old
.enabled
, s
.enabled
, old
.log_passwd
,
1372 s
.log_passwd
, !err
);
1381 return err
< 0 ? err
: 0;
1385 * Get message from skb. Each message is processed by audit_receive_msg.
1386 * Malformed skbs with wrong length are discarded silently.
1388 static void audit_receive_skb(struct sk_buff
*skb
)
1390 struct nlmsghdr
*nlh
;
1392 * len MUST be signed for nlmsg_next to be able to dec it below 0
1393 * if the nlmsg_len was not aligned
1398 nlh
= nlmsg_hdr(skb
);
1401 while (nlmsg_ok(nlh
, len
)) {
1402 err
= audit_receive_msg(skb
, nlh
);
1403 /* if err or if this message says it wants a response */
1404 if (err
|| (nlh
->nlmsg_flags
& NLM_F_ACK
))
1405 netlink_ack(skb
, nlh
, err
);
1407 nlh
= nlmsg_next(nlh
, &len
);
1411 /* Receive messages from netlink socket. */
1412 static void audit_receive(struct sk_buff
*skb
)
1414 mutex_lock(&audit_cmd_mutex
);
1415 audit_receive_skb(skb
);
1416 mutex_unlock(&audit_cmd_mutex
);
1419 /* Run custom bind function on netlink socket group connect or bind requests. */
1420 static int audit_bind(struct net
*net
, int group
)
1422 if (!capable(CAP_AUDIT_READ
))
1428 static int __net_init
audit_net_init(struct net
*net
)
1430 struct netlink_kernel_cfg cfg
= {
1431 .input
= audit_receive
,
1433 .flags
= NL_CFG_F_NONROOT_RECV
,
1434 .groups
= AUDIT_NLGRP_MAX
,
1437 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
1439 aunet
->sk
= netlink_kernel_create(net
, NETLINK_AUDIT
, &cfg
);
1440 if (aunet
->sk
== NULL
) {
1441 audit_panic("cannot initialize netlink socket in namespace");
1444 aunet
->sk
->sk_sndtimeo
= MAX_SCHEDULE_TIMEOUT
;
1449 static void __net_exit
audit_net_exit(struct net
*net
)
1451 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
1454 if (net
== auditd_conn
.net
)
1458 netlink_kernel_release(aunet
->sk
);
1461 static struct pernet_operations audit_net_ops __net_initdata
= {
1462 .init
= audit_net_init
,
1463 .exit
= audit_net_exit
,
1464 .id
= &audit_net_id
,
1465 .size
= sizeof(struct audit_net
),
1468 /* Initialize audit support at boot time. */
1469 static int __init
audit_init(void)
1473 if (audit_initialized
== AUDIT_DISABLED
)
1476 memset(&auditd_conn
, 0, sizeof(auditd_conn
));
1477 spin_lock_init(&auditd_conn
.lock
);
1479 skb_queue_head_init(&audit_queue
);
1480 skb_queue_head_init(&audit_retry_queue
);
1481 skb_queue_head_init(&audit_hold_queue
);
1483 for (i
= 0; i
< AUDIT_INODE_BUCKETS
; i
++)
1484 INIT_LIST_HEAD(&audit_inode_hash
[i
]);
1486 pr_info("initializing netlink subsys (%s)\n",
1487 audit_default
? "enabled" : "disabled");
1488 register_pernet_subsys(&audit_net_ops
);
1490 audit_initialized
= AUDIT_INITIALIZED
;
1491 audit_enabled
= audit_default
;
1492 audit_ever_enabled
|= !!audit_default
;
1494 kauditd_task
= kthread_run(kauditd_thread
, NULL
, "kauditd");
1495 if (IS_ERR(kauditd_task
)) {
1496 int err
= PTR_ERR(kauditd_task
);
1497 panic("audit: failed to start the kauditd thread (%d)\n", err
);
1500 audit_log(NULL
, GFP_KERNEL
, AUDIT_KERNEL
,
1501 "state=initialized audit_enabled=%u res=1",
1506 __initcall(audit_init
);
1508 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1509 static int __init
audit_enable(char *str
)
1511 audit_default
= !!simple_strtol(str
, NULL
, 0);
1513 audit_initialized
= AUDIT_DISABLED
;
1515 pr_info("%s\n", audit_default
?
1516 "enabled (after initialization)" : "disabled (until reboot)");
1520 __setup("audit=", audit_enable
);
1522 /* Process kernel command-line parameter at boot time.
1523 * audit_backlog_limit=<n> */
1524 static int __init
audit_backlog_limit_set(char *str
)
1526 u32 audit_backlog_limit_arg
;
1528 pr_info("audit_backlog_limit: ");
1529 if (kstrtouint(str
, 0, &audit_backlog_limit_arg
)) {
1530 pr_cont("using default of %u, unable to parse %s\n",
1531 audit_backlog_limit
, str
);
1535 audit_backlog_limit
= audit_backlog_limit_arg
;
1536 pr_cont("%d\n", audit_backlog_limit
);
1540 __setup("audit_backlog_limit=", audit_backlog_limit_set
);
1542 static void audit_buffer_free(struct audit_buffer
*ab
)
1544 unsigned long flags
;
1550 spin_lock_irqsave(&audit_freelist_lock
, flags
);
1551 if (audit_freelist_count
> AUDIT_MAXFREE
)
1554 audit_freelist_count
++;
1555 list_add(&ab
->list
, &audit_freelist
);
1557 spin_unlock_irqrestore(&audit_freelist_lock
, flags
);
1560 static struct audit_buffer
* audit_buffer_alloc(struct audit_context
*ctx
,
1561 gfp_t gfp_mask
, int type
)
1563 unsigned long flags
;
1564 struct audit_buffer
*ab
= NULL
;
1565 struct nlmsghdr
*nlh
;
1567 spin_lock_irqsave(&audit_freelist_lock
, flags
);
1568 if (!list_empty(&audit_freelist
)) {
1569 ab
= list_entry(audit_freelist
.next
,
1570 struct audit_buffer
, list
);
1571 list_del(&ab
->list
);
1572 --audit_freelist_count
;
1574 spin_unlock_irqrestore(&audit_freelist_lock
, flags
);
1577 ab
= kmalloc(sizeof(*ab
), gfp_mask
);
1583 ab
->gfp_mask
= gfp_mask
;
1585 ab
->skb
= nlmsg_new(AUDIT_BUFSIZ
, gfp_mask
);
1589 nlh
= nlmsg_put(ab
->skb
, 0, 0, type
, 0, 0);
1599 audit_buffer_free(ab
);
1604 * audit_serial - compute a serial number for the audit record
1606 * Compute a serial number for the audit record. Audit records are
1607 * written to user-space as soon as they are generated, so a complete
1608 * audit record may be written in several pieces. The timestamp of the
1609 * record and this serial number are used by the user-space tools to
1610 * determine which pieces belong to the same audit record. The
1611 * (timestamp,serial) tuple is unique for each syscall and is live from
1612 * syscall entry to syscall exit.
1614 * NOTE: Another possibility is to store the formatted records off the
1615 * audit context (for those records that have a context), and emit them
1616 * all at syscall exit. However, this could delay the reporting of
1617 * significant errors until syscall exit (or never, if the system
1620 unsigned int audit_serial(void)
1622 static atomic_t serial
= ATOMIC_INIT(0);
1624 return atomic_add_return(1, &serial
);
1627 static inline void audit_get_stamp(struct audit_context
*ctx
,
1628 struct timespec
*t
, unsigned int *serial
)
1630 if (!ctx
|| !auditsc_get_stamp(ctx
, t
, serial
)) {
1632 *serial
= audit_serial();
1637 * audit_log_start - obtain an audit buffer
1638 * @ctx: audit_context (may be NULL)
1639 * @gfp_mask: type of allocation
1640 * @type: audit message type
1642 * Returns audit_buffer pointer on success or NULL on error.
1644 * Obtain an audit buffer. This routine does locking to obtain the
1645 * audit buffer, but then no locking is required for calls to
1646 * audit_log_*format. If the task (ctx) is a task that is currently in a
1647 * syscall, then the syscall is marked as auditable and an audit record
1648 * will be written at syscall exit. If there is no associated task, then
1649 * task context (ctx) should be NULL.
1651 struct audit_buffer
*audit_log_start(struct audit_context
*ctx
, gfp_t gfp_mask
,
1654 struct audit_buffer
*ab
;
1656 unsigned int uninitialized_var(serial
);
1658 if (audit_initialized
!= AUDIT_INITIALIZED
)
1661 if (unlikely(!audit_filter(type
, AUDIT_FILTER_TYPE
)))
1664 /* NOTE: don't ever fail/sleep on these two conditions:
1665 * 1. auditd generated record - since we need auditd to drain the
1666 * queue; also, when we are checking for auditd, compare PIDs using
1667 * task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
1668 * using a PID anchored in the caller's namespace
1669 * 2. generator holding the audit_cmd_mutex - we don't want to block
1670 * while holding the mutex */
1671 if (!(auditd_test_task(current
) ||
1672 (current
== __mutex_owner(&audit_cmd_mutex
)))) {
1673 long stime
= audit_backlog_wait_time
;
1675 while (audit_backlog_limit
&&
1676 (skb_queue_len(&audit_queue
) > audit_backlog_limit
)) {
1677 /* wake kauditd to try and flush the queue */
1678 wake_up_interruptible(&kauditd_wait
);
1680 /* sleep if we are allowed and we haven't exhausted our
1681 * backlog wait limit */
1682 if (gfpflags_allow_blocking(gfp_mask
) && (stime
> 0)) {
1683 DECLARE_WAITQUEUE(wait
, current
);
1685 add_wait_queue_exclusive(&audit_backlog_wait
,
1687 set_current_state(TASK_UNINTERRUPTIBLE
);
1688 stime
= schedule_timeout(stime
);
1689 remove_wait_queue(&audit_backlog_wait
, &wait
);
1691 if (audit_rate_check() && printk_ratelimit())
1692 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1693 skb_queue_len(&audit_queue
),
1694 audit_backlog_limit
);
1695 audit_log_lost("backlog limit exceeded");
1701 ab
= audit_buffer_alloc(ctx
, gfp_mask
, type
);
1703 audit_log_lost("out of memory in audit_log_start");
1707 audit_get_stamp(ab
->ctx
, &t
, &serial
);
1708 audit_log_format(ab
, "audit(%lu.%03lu:%u): ",
1709 t
.tv_sec
, t
.tv_nsec
/1000000, serial
);
1715 * audit_expand - expand skb in the audit buffer
1717 * @extra: space to add at tail of the skb
1719 * Returns 0 (no space) on failed expansion, or available space if
1722 static inline int audit_expand(struct audit_buffer
*ab
, int extra
)
1724 struct sk_buff
*skb
= ab
->skb
;
1725 int oldtail
= skb_tailroom(skb
);
1726 int ret
= pskb_expand_head(skb
, 0, extra
, ab
->gfp_mask
);
1727 int newtail
= skb_tailroom(skb
);
1730 audit_log_lost("out of memory in audit_expand");
1734 skb
->truesize
+= newtail
- oldtail
;
1739 * Format an audit message into the audit buffer. If there isn't enough
1740 * room in the audit buffer, more room will be allocated and vsnprint
1741 * will be called a second time. Currently, we assume that a printk
1742 * can't format message larger than 1024 bytes, so we don't either.
1744 static void audit_log_vformat(struct audit_buffer
*ab
, const char *fmt
,
1748 struct sk_buff
*skb
;
1756 avail
= skb_tailroom(skb
);
1758 avail
= audit_expand(ab
, AUDIT_BUFSIZ
);
1762 va_copy(args2
, args
);
1763 len
= vsnprintf(skb_tail_pointer(skb
), avail
, fmt
, args
);
1765 /* The printk buffer is 1024 bytes long, so if we get
1766 * here and AUDIT_BUFSIZ is at least 1024, then we can
1767 * log everything that printk could have logged. */
1768 avail
= audit_expand(ab
,
1769 max_t(unsigned, AUDIT_BUFSIZ
, 1+len
-avail
));
1772 len
= vsnprintf(skb_tail_pointer(skb
), avail
, fmt
, args2
);
1783 * audit_log_format - format a message into the audit buffer.
1785 * @fmt: format string
1786 * @...: optional parameters matching @fmt string
1788 * All the work is done in audit_log_vformat.
1790 void audit_log_format(struct audit_buffer
*ab
, const char *fmt
, ...)
1796 va_start(args
, fmt
);
1797 audit_log_vformat(ab
, fmt
, args
);
1802 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1803 * @ab: the audit_buffer
1804 * @buf: buffer to convert to hex
1805 * @len: length of @buf to be converted
1807 * No return value; failure to expand is silently ignored.
1809 * This function will take the passed buf and convert it into a string of
1810 * ascii hex digits. The new string is placed onto the skb.
1812 void audit_log_n_hex(struct audit_buffer
*ab
, const unsigned char *buf
,
1815 int i
, avail
, new_len
;
1817 struct sk_buff
*skb
;
1824 avail
= skb_tailroom(skb
);
1826 if (new_len
>= avail
) {
1827 /* Round the buffer request up to the next multiple */
1828 new_len
= AUDIT_BUFSIZ
*(((new_len
-avail
)/AUDIT_BUFSIZ
) + 1);
1829 avail
= audit_expand(ab
, new_len
);
1834 ptr
= skb_tail_pointer(skb
);
1835 for (i
= 0; i
< len
; i
++)
1836 ptr
= hex_byte_pack_upper(ptr
, buf
[i
]);
1838 skb_put(skb
, len
<< 1); /* new string is twice the old string */
1842 * Format a string of no more than slen characters into the audit buffer,
1843 * enclosed in quote marks.
1845 void audit_log_n_string(struct audit_buffer
*ab
, const char *string
,
1850 struct sk_buff
*skb
;
1857 avail
= skb_tailroom(skb
);
1858 new_len
= slen
+ 3; /* enclosing quotes + null terminator */
1859 if (new_len
> avail
) {
1860 avail
= audit_expand(ab
, new_len
);
1864 ptr
= skb_tail_pointer(skb
);
1866 memcpy(ptr
, string
, slen
);
1870 skb_put(skb
, slen
+ 2); /* don't include null terminator */
1874 * audit_string_contains_control - does a string need to be logged in hex
1875 * @string: string to be checked
1876 * @len: max length of the string to check
1878 bool audit_string_contains_control(const char *string
, size_t len
)
1880 const unsigned char *p
;
1881 for (p
= string
; p
< (const unsigned char *)string
+ len
; p
++) {
1882 if (*p
== '"' || *p
< 0x21 || *p
> 0x7e)
1889 * audit_log_n_untrustedstring - log a string that may contain random characters
1891 * @len: length of string (not including trailing null)
1892 * @string: string to be logged
1894 * This code will escape a string that is passed to it if the string
1895 * contains a control character, unprintable character, double quote mark,
1896 * or a space. Unescaped strings will start and end with a double quote mark.
1897 * Strings that are escaped are printed in hex (2 digits per char).
1899 * The caller specifies the number of characters in the string to log, which may
1900 * or may not be the entire string.
1902 void audit_log_n_untrustedstring(struct audit_buffer
*ab
, const char *string
,
1905 if (audit_string_contains_control(string
, len
))
1906 audit_log_n_hex(ab
, string
, len
);
1908 audit_log_n_string(ab
, string
, len
);
1912 * audit_log_untrustedstring - log a string that may contain random characters
1914 * @string: string to be logged
1916 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1917 * determine string length.
1919 void audit_log_untrustedstring(struct audit_buffer
*ab
, const char *string
)
1921 audit_log_n_untrustedstring(ab
, string
, strlen(string
));
1924 /* This is a helper-function to print the escaped d_path */
1925 void audit_log_d_path(struct audit_buffer
*ab
, const char *prefix
,
1926 const struct path
*path
)
1931 audit_log_format(ab
, "%s", prefix
);
1933 /* We will allow 11 spaces for ' (deleted)' to be appended */
1934 pathname
= kmalloc(PATH_MAX
+11, ab
->gfp_mask
);
1936 audit_log_string(ab
, "<no_memory>");
1939 p
= d_path(path
, pathname
, PATH_MAX
+11);
1940 if (IS_ERR(p
)) { /* Should never happen since we send PATH_MAX */
1941 /* FIXME: can we save some information here? */
1942 audit_log_string(ab
, "<too_long>");
1944 audit_log_untrustedstring(ab
, p
);
1948 void audit_log_session_info(struct audit_buffer
*ab
)
1950 unsigned int sessionid
= audit_get_sessionid(current
);
1951 uid_t auid
= from_kuid(&init_user_ns
, audit_get_loginuid(current
));
1953 audit_log_format(ab
, " auid=%u ses=%u", auid
, sessionid
);
1956 void audit_log_key(struct audit_buffer
*ab
, char *key
)
1958 audit_log_format(ab
, " key=");
1960 audit_log_untrustedstring(ab
, key
);
1962 audit_log_format(ab
, "(null)");
1965 void audit_log_cap(struct audit_buffer
*ab
, char *prefix
, kernel_cap_t
*cap
)
1969 audit_log_format(ab
, " %s=", prefix
);
1970 CAP_FOR_EACH_U32(i
) {
1971 audit_log_format(ab
, "%08x",
1972 cap
->cap
[CAP_LAST_U32
- i
]);
1976 static void audit_log_fcaps(struct audit_buffer
*ab
, struct audit_names
*name
)
1978 kernel_cap_t
*perm
= &name
->fcap
.permitted
;
1979 kernel_cap_t
*inh
= &name
->fcap
.inheritable
;
1982 if (!cap_isclear(*perm
)) {
1983 audit_log_cap(ab
, "cap_fp", perm
);
1986 if (!cap_isclear(*inh
)) {
1987 audit_log_cap(ab
, "cap_fi", inh
);
1992 audit_log_format(ab
, " cap_fe=%d cap_fver=%x",
1993 name
->fcap
.fE
, name
->fcap_ver
);
1996 static inline int audit_copy_fcaps(struct audit_names
*name
,
1997 const struct dentry
*dentry
)
1999 struct cpu_vfs_cap_data caps
;
2005 rc
= get_vfs_caps_from_disk(dentry
, &caps
);
2009 name
->fcap
.permitted
= caps
.permitted
;
2010 name
->fcap
.inheritable
= caps
.inheritable
;
2011 name
->fcap
.fE
= !!(caps
.magic_etc
& VFS_CAP_FLAGS_EFFECTIVE
);
2012 name
->fcap_ver
= (caps
.magic_etc
& VFS_CAP_REVISION_MASK
) >>
2013 VFS_CAP_REVISION_SHIFT
;
2018 /* Copy inode data into an audit_names. */
2019 void audit_copy_inode(struct audit_names
*name
, const struct dentry
*dentry
,
2020 struct inode
*inode
)
2022 name
->ino
= inode
->i_ino
;
2023 name
->dev
= inode
->i_sb
->s_dev
;
2024 name
->mode
= inode
->i_mode
;
2025 name
->uid
= inode
->i_uid
;
2026 name
->gid
= inode
->i_gid
;
2027 name
->rdev
= inode
->i_rdev
;
2028 security_inode_getsecid(inode
, &name
->osid
);
2029 audit_copy_fcaps(name
, dentry
);
2033 * audit_log_name - produce AUDIT_PATH record from struct audit_names
2034 * @context: audit_context for the task
2035 * @n: audit_names structure with reportable details
2036 * @path: optional path to report instead of audit_names->name
2037 * @record_num: record number to report when handling a list of names
2038 * @call_panic: optional pointer to int that will be updated if secid fails
2040 void audit_log_name(struct audit_context
*context
, struct audit_names
*n
,
2041 const struct path
*path
, int record_num
, int *call_panic
)
2043 struct audit_buffer
*ab
;
2044 ab
= audit_log_start(context
, GFP_KERNEL
, AUDIT_PATH
);
2048 audit_log_format(ab
, "item=%d", record_num
);
2051 audit_log_d_path(ab
, " name=", path
);
2053 switch (n
->name_len
) {
2054 case AUDIT_NAME_FULL
:
2055 /* log the full path */
2056 audit_log_format(ab
, " name=");
2057 audit_log_untrustedstring(ab
, n
->name
->name
);
2060 /* name was specified as a relative path and the
2061 * directory component is the cwd */
2062 audit_log_d_path(ab
, " name=", &context
->pwd
);
2065 /* log the name's directory component */
2066 audit_log_format(ab
, " name=");
2067 audit_log_n_untrustedstring(ab
, n
->name
->name
,
2071 audit_log_format(ab
, " name=(null)");
2073 if (n
->ino
!= AUDIT_INO_UNSET
)
2074 audit_log_format(ab
, " inode=%lu"
2075 " dev=%02x:%02x mode=%#ho"
2076 " ouid=%u ogid=%u rdev=%02x:%02x",
2081 from_kuid(&init_user_ns
, n
->uid
),
2082 from_kgid(&init_user_ns
, n
->gid
),
2088 if (security_secid_to_secctx(
2089 n
->osid
, &ctx
, &len
)) {
2090 audit_log_format(ab
, " osid=%u", n
->osid
);
2094 audit_log_format(ab
, " obj=%s", ctx
);
2095 security_release_secctx(ctx
, len
);
2099 /* log the audit_names record type */
2100 audit_log_format(ab
, " nametype=");
2102 case AUDIT_TYPE_NORMAL
:
2103 audit_log_format(ab
, "NORMAL");
2105 case AUDIT_TYPE_PARENT
:
2106 audit_log_format(ab
, "PARENT");
2108 case AUDIT_TYPE_CHILD_DELETE
:
2109 audit_log_format(ab
, "DELETE");
2111 case AUDIT_TYPE_CHILD_CREATE
:
2112 audit_log_format(ab
, "CREATE");
2115 audit_log_format(ab
, "UNKNOWN");
2119 audit_log_fcaps(ab
, n
);
2123 int audit_log_task_context(struct audit_buffer
*ab
)
2130 security_task_getsecid(current
, &sid
);
2134 error
= security_secid_to_secctx(sid
, &ctx
, &len
);
2136 if (error
!= -EINVAL
)
2141 audit_log_format(ab
, " subj=%s", ctx
);
2142 security_release_secctx(ctx
, len
);
2146 audit_panic("error in audit_log_task_context");
2149 EXPORT_SYMBOL(audit_log_task_context
);
2151 void audit_log_d_path_exe(struct audit_buffer
*ab
,
2152 struct mm_struct
*mm
)
2154 struct file
*exe_file
;
2159 exe_file
= get_mm_exe_file(mm
);
2163 audit_log_d_path(ab
, " exe=", &exe_file
->f_path
);
2167 audit_log_format(ab
, " exe=(null)");
2170 struct tty_struct
*audit_get_tty(struct task_struct
*tsk
)
2172 struct tty_struct
*tty
= NULL
;
2173 unsigned long flags
;
2175 spin_lock_irqsave(&tsk
->sighand
->siglock
, flags
);
2177 tty
= tty_kref_get(tsk
->signal
->tty
);
2178 spin_unlock_irqrestore(&tsk
->sighand
->siglock
, flags
);
2182 void audit_put_tty(struct tty_struct
*tty
)
2187 void audit_log_task_info(struct audit_buffer
*ab
, struct task_struct
*tsk
)
2189 const struct cred
*cred
;
2190 char comm
[sizeof(tsk
->comm
)];
2191 struct tty_struct
*tty
;
2196 /* tsk == current */
2197 cred
= current_cred();
2198 tty
= audit_get_tty(tsk
);
2199 audit_log_format(ab
,
2200 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
2201 " euid=%u suid=%u fsuid=%u"
2202 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
2205 from_kuid(&init_user_ns
, audit_get_loginuid(tsk
)),
2206 from_kuid(&init_user_ns
, cred
->uid
),
2207 from_kgid(&init_user_ns
, cred
->gid
),
2208 from_kuid(&init_user_ns
, cred
->euid
),
2209 from_kuid(&init_user_ns
, cred
->suid
),
2210 from_kuid(&init_user_ns
, cred
->fsuid
),
2211 from_kgid(&init_user_ns
, cred
->egid
),
2212 from_kgid(&init_user_ns
, cred
->sgid
),
2213 from_kgid(&init_user_ns
, cred
->fsgid
),
2214 tty
? tty_name(tty
) : "(none)",
2215 audit_get_sessionid(tsk
));
2217 audit_log_format(ab
, " comm=");
2218 audit_log_untrustedstring(ab
, get_task_comm(comm
, tsk
));
2219 audit_log_d_path_exe(ab
, tsk
->mm
);
2220 audit_log_task_context(ab
);
2222 EXPORT_SYMBOL(audit_log_task_info
);
2225 * audit_log_link_denied - report a link restriction denial
2226 * @operation: specific link operation
2227 * @link: the path that triggered the restriction
2229 void audit_log_link_denied(const char *operation
, const struct path
*link
)
2231 struct audit_buffer
*ab
;
2232 struct audit_names
*name
;
2234 name
= kzalloc(sizeof(*name
), GFP_NOFS
);
2238 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
2239 ab
= audit_log_start(current
->audit_context
, GFP_KERNEL
,
2243 audit_log_format(ab
, "op=%s", operation
);
2244 audit_log_task_info(ab
, current
);
2245 audit_log_format(ab
, " res=0");
2248 /* Generate AUDIT_PATH record with object. */
2249 name
->type
= AUDIT_TYPE_NORMAL
;
2250 audit_copy_inode(name
, link
->dentry
, d_backing_inode(link
->dentry
));
2251 audit_log_name(current
->audit_context
, name
, link
, 0, NULL
);
2257 * audit_log_end - end one audit record
2258 * @ab: the audit_buffer
2260 * We can not do a netlink send inside an irq context because it blocks (last
2261 * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
2262 * queue and a tasklet is scheduled to remove them from the queue outside the
2263 * irq context. May be called in any context.
2265 void audit_log_end(struct audit_buffer
*ab
)
2267 struct sk_buff
*skb
;
2268 struct nlmsghdr
*nlh
;
2273 if (audit_rate_check()) {
2277 /* setup the netlink header, see the comments in
2278 * kauditd_send_multicast_skb() for length quirks */
2279 nlh
= nlmsg_hdr(skb
);
2280 nlh
->nlmsg_len
= skb
->len
- NLMSG_HDRLEN
;
2282 /* queue the netlink packet and poke the kauditd thread */
2283 skb_queue_tail(&audit_queue
, skb
);
2284 wake_up_interruptible(&kauditd_wait
);
2286 audit_log_lost("rate limit exceeded");
2288 audit_buffer_free(ab
);
2292 * audit_log - Log an audit record
2293 * @ctx: audit context
2294 * @gfp_mask: type of allocation
2295 * @type: audit message type
2296 * @fmt: format string to use
2297 * @...: variable parameters matching the format string
2299 * This is a convenience function that calls audit_log_start,
2300 * audit_log_vformat, and audit_log_end. It may be called
2303 void audit_log(struct audit_context
*ctx
, gfp_t gfp_mask
, int type
,
2304 const char *fmt
, ...)
2306 struct audit_buffer
*ab
;
2309 ab
= audit_log_start(ctx
, gfp_mask
, type
);
2311 va_start(args
, fmt
);
2312 audit_log_vformat(ab
, fmt
, args
);
2318 #ifdef CONFIG_SECURITY
2320 * audit_log_secctx - Converts and logs SELinux context
2322 * @secid: security number
2324 * This is a helper function that calls security_secid_to_secctx to convert
2325 * secid to secctx and then adds the (converted) SELinux context to the audit
2326 * log by calling audit_log_format, thus also preventing leak of internal secid
2327 * to userspace. If secid cannot be converted audit_panic is called.
2329 void audit_log_secctx(struct audit_buffer
*ab
, u32 secid
)
2334 if (security_secid_to_secctx(secid
, &secctx
, &len
)) {
2335 audit_panic("Cannot convert secid to context");
2337 audit_log_format(ab
, " obj=%s", secctx
);
2338 security_release_secctx(secctx
, len
);
2341 EXPORT_SYMBOL(audit_log_secctx
);
2344 EXPORT_SYMBOL(audit_log_start
);
2345 EXPORT_SYMBOL(audit_log_end
);
2346 EXPORT_SYMBOL(audit_log_format
);
2347 EXPORT_SYMBOL(audit_log
);