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>
58 #include <linux/audit.h>
61 #include <net/netlink.h>
62 #include <linux/skbuff.h>
63 #ifdef CONFIG_SECURITY
64 #include <linux/security.h>
66 #include <linux/freezer.h>
67 #include <linux/pid_namespace.h>
68 #include <net/netns/generic.h>
72 /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
73 * (Initialization happens after skb_init is called.) */
74 #define AUDIT_DISABLED -1
75 #define AUDIT_UNINITIALIZED 0
76 #define AUDIT_INITIALIZED 1
77 static int audit_initialized
;
81 #define AUDIT_LOCKED 2
83 u32 audit_ever_enabled
;
85 EXPORT_SYMBOL_GPL(audit_enabled
);
87 /* Default state when kernel boots without any parameters. */
88 static u32 audit_default
;
90 /* If auditing cannot proceed, audit_failure selects what happens. */
91 static u32 audit_failure
= AUDIT_FAIL_PRINTK
;
94 * If audit records are to be written to the netlink socket, audit_pid
95 * contains the pid of the auditd process and audit_nlk_portid contains
96 * the portid to use to send netlink messages to that process.
99 static __u32 audit_nlk_portid
;
101 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
102 * to that number per second. This prevents DoS attacks, but results in
103 * audit records being dropped. */
104 static u32 audit_rate_limit
;
106 /* Number of outstanding audit_buffers allowed.
107 * When set to zero, this means unlimited. */
108 static u32 audit_backlog_limit
= 64;
109 #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
110 static u32 audit_backlog_wait_time_master
= AUDIT_BACKLOG_WAIT_TIME
;
111 static u32 audit_backlog_wait_time
= AUDIT_BACKLOG_WAIT_TIME
;
113 /* The identity of the user shutting down the audit system. */
114 kuid_t audit_sig_uid
= INVALID_UID
;
115 pid_t audit_sig_pid
= -1;
116 u32 audit_sig_sid
= 0;
118 /* Records can be lost in several ways:
119 0) [suppressed in audit_alloc]
120 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
121 2) out of memory in audit_log_move [alloc_skb]
122 3) suppressed due to audit_rate_limit
123 4) suppressed due to audit_backlog_limit
125 static atomic_t audit_lost
= ATOMIC_INIT(0);
127 /* The netlink socket. */
128 static struct sock
*audit_sock
;
129 static int audit_net_id
;
131 /* Hash for inode-based rules */
132 struct list_head audit_inode_hash
[AUDIT_INODE_BUCKETS
];
134 /* The audit_freelist is a list of pre-allocated audit buffers (if more
135 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
136 * being placed on the freelist). */
137 static DEFINE_SPINLOCK(audit_freelist_lock
);
138 static int audit_freelist_count
;
139 static LIST_HEAD(audit_freelist
);
141 static struct sk_buff_head audit_queue
;
142 /* queue of skbs to send to auditd when/if it comes back */
143 static struct sk_buff_head audit_hold_queue
;
144 static struct task_struct
*kauditd_task
;
145 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait
);
146 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait
);
148 static struct audit_features af
= {.vers
= AUDIT_FEATURE_VERSION
,
153 static char *audit_feature_names
[2] = {
154 "only_unset_loginuid",
155 "loginuid_immutable",
159 /* Serialize requests from userspace. */
160 DEFINE_MUTEX(audit_cmd_mutex
);
162 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
163 * audit records. Since printk uses a 1024 byte buffer, this buffer
164 * should be at least that large. */
165 #define AUDIT_BUFSIZ 1024
167 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
168 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
169 #define AUDIT_MAXFREE (2*NR_CPUS)
171 /* The audit_buffer is used when formatting an audit record. The caller
172 * locks briefly to get the record off the freelist or to allocate the
173 * buffer, and locks briefly to send the buffer to the netlink layer or
174 * to place it on a transmit queue. Multiple audit_buffers can be in
175 * use simultaneously. */
176 struct audit_buffer
{
177 struct list_head list
;
178 struct sk_buff
*skb
; /* formatted skb ready to send */
179 struct audit_context
*ctx
; /* NULL or associated context */
189 static void audit_set_portid(struct audit_buffer
*ab
, __u32 portid
)
192 struct nlmsghdr
*nlh
= nlmsg_hdr(ab
->skb
);
193 nlh
->nlmsg_pid
= portid
;
197 void audit_panic(const char *message
)
199 switch (audit_failure
) {
200 case AUDIT_FAIL_SILENT
:
202 case AUDIT_FAIL_PRINTK
:
203 if (printk_ratelimit())
204 pr_err("%s\n", message
);
206 case AUDIT_FAIL_PANIC
:
207 /* test audit_pid since printk is always losey, why bother? */
209 panic("audit: %s\n", message
);
214 static inline int audit_rate_check(void)
216 static unsigned long last_check
= 0;
217 static int messages
= 0;
218 static DEFINE_SPINLOCK(lock
);
221 unsigned long elapsed
;
224 if (!audit_rate_limit
) return 1;
226 spin_lock_irqsave(&lock
, flags
);
227 if (++messages
< audit_rate_limit
) {
231 elapsed
= now
- last_check
;
238 spin_unlock_irqrestore(&lock
, flags
);
244 * audit_log_lost - conditionally log lost audit message event
245 * @message: the message stating reason for lost audit message
247 * Emit at least 1 message per second, even if audit_rate_check is
249 * Always increment the lost messages counter.
251 void audit_log_lost(const char *message
)
253 static unsigned long last_msg
= 0;
254 static DEFINE_SPINLOCK(lock
);
259 atomic_inc(&audit_lost
);
261 print
= (audit_failure
== AUDIT_FAIL_PANIC
|| !audit_rate_limit
);
264 spin_lock_irqsave(&lock
, flags
);
266 if (now
- last_msg
> HZ
) {
270 spin_unlock_irqrestore(&lock
, flags
);
274 if (printk_ratelimit())
275 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
276 atomic_read(&audit_lost
),
278 audit_backlog_limit
);
279 audit_panic(message
);
283 static int audit_log_config_change(char *function_name
, u32
new, u32 old
,
286 struct audit_buffer
*ab
;
289 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
292 audit_log_format(ab
, "%s=%u old=%u", function_name
, new, old
);
293 audit_log_session_info(ab
);
294 rc
= audit_log_task_context(ab
);
296 allow_changes
= 0; /* Something weird, deny request */
297 audit_log_format(ab
, " res=%d", allow_changes
);
302 static int audit_do_config_change(char *function_name
, u32
*to_change
, u32
new)
304 int allow_changes
, rc
= 0;
305 u32 old
= *to_change
;
307 /* check if we are locked */
308 if (audit_enabled
== AUDIT_LOCKED
)
313 if (audit_enabled
!= AUDIT_OFF
) {
314 rc
= audit_log_config_change(function_name
, new, old
, allow_changes
);
319 /* If we are allowed, make the change */
320 if (allow_changes
== 1)
322 /* Not allowed, update reason */
328 static int audit_set_rate_limit(u32 limit
)
330 return audit_do_config_change("audit_rate_limit", &audit_rate_limit
, limit
);
333 static int audit_set_backlog_limit(u32 limit
)
335 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit
, limit
);
338 static int audit_set_backlog_wait_time(u32 timeout
)
340 return audit_do_config_change("audit_backlog_wait_time",
341 &audit_backlog_wait_time_master
, timeout
);
344 static int audit_set_enabled(u32 state
)
347 if (state
> AUDIT_LOCKED
)
350 rc
= audit_do_config_change("audit_enabled", &audit_enabled
, state
);
352 audit_ever_enabled
|= !!state
;
357 static int audit_set_failure(u32 state
)
359 if (state
!= AUDIT_FAIL_SILENT
360 && state
!= AUDIT_FAIL_PRINTK
361 && state
!= AUDIT_FAIL_PANIC
)
364 return audit_do_config_change("audit_failure", &audit_failure
, state
);
368 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
369 * already have been sent via prink/syslog and so if these messages are dropped
370 * it is not a huge concern since we already passed the audit_log_lost()
371 * notification and stuff. This is just nice to get audit messages during
372 * boot before auditd is running or messages generated while auditd is stopped.
373 * This only holds messages is audit_default is set, aka booting with audit=1
374 * or building your kernel that way.
376 static void audit_hold_skb(struct sk_buff
*skb
)
379 (!audit_backlog_limit
||
380 skb_queue_len(&audit_hold_queue
) < audit_backlog_limit
))
381 skb_queue_tail(&audit_hold_queue
, skb
);
387 * For one reason or another this nlh isn't getting delivered to the userspace
388 * audit daemon, just send it to printk.
390 static void kauditd_printk_skb(struct sk_buff
*skb
)
392 struct nlmsghdr
*nlh
= nlmsg_hdr(skb
);
393 char *data
= nlmsg_data(nlh
);
395 if (nlh
->nlmsg_type
!= AUDIT_EOE
) {
396 if (printk_ratelimit())
397 pr_notice("type=%d %s\n", nlh
->nlmsg_type
, data
);
399 audit_log_lost("printk limit exceeded");
405 static void kauditd_send_unicast_skb(struct sk_buff
*skb
)
409 #define AUDITD_RETRIES 5
412 /* take a reference in case we can't send it and we want to hold it */
414 err
= netlink_unicast(audit_sock
, skb
, audit_nlk_portid
, 0);
416 pr_err("netlink_unicast sending to audit_pid=%d returned error: %d\n",
419 if (err
== -ECONNREFUSED
|| err
== -EPERM
420 || ++attempts
>= AUDITD_RETRIES
) {
423 snprintf(s
, sizeof(s
), "audit_pid=%d reset", audit_pid
);
428 pr_warn("re-scheduling(#%d) write to audit_pid=%d\n",
429 attempts
, audit_pid
);
430 set_current_state(TASK_INTERRUPTIBLE
);
435 /* we might get lucky and get this in the next auditd */
438 /* drop the extra reference if sent ok */
443 * kauditd_send_multicast_skb - send the skb to multicast userspace listeners
445 * This function doesn't consume an skb as might be expected since it has to
448 static void kauditd_send_multicast_skb(struct sk_buff
*skb
, gfp_t gfp_mask
)
450 struct sk_buff
*copy
;
451 struct audit_net
*aunet
= net_generic(&init_net
, audit_net_id
);
452 struct sock
*sock
= aunet
->nlsk
;
454 if (!netlink_has_listeners(sock
, AUDIT_NLGRP_READLOG
))
458 * The seemingly wasteful skb_copy() rather than bumping the refcount
459 * using skb_get() is necessary because non-standard mods are made to
460 * the skb by the original kaudit unicast socket send routine. The
461 * existing auditd daemon assumes this breakage. Fixing this would
462 * require co-ordinating a change in the established protocol between
463 * the kaudit kernel subsystem and the auditd userspace code. There is
464 * no reason for new multicast clients to continue with this
467 copy
= skb_copy(skb
, gfp_mask
);
471 nlmsg_multicast(sock
, copy
, 0, AUDIT_NLGRP_READLOG
, gfp_mask
);
475 * flush_hold_queue - empty the hold queue if auditd appears
477 * If auditd just started, drain the queue of messages already
478 * sent to syslog/printk. Remember loss here is ok. We already
479 * called audit_log_lost() if it didn't go out normally. so the
480 * race between the skb_dequeue and the next check for audit_pid
483 * If you ever find kauditd to be too slow we can get a perf win
484 * by doing our own locking and keeping better track if there
485 * are messages in this queue. I don't see the need now, but
486 * in 5 years when I want to play with this again I'll see this
487 * note and still have no friggin idea what i'm thinking today.
489 static void flush_hold_queue(void)
493 if (!audit_default
|| !audit_pid
)
496 skb
= skb_dequeue(&audit_hold_queue
);
500 while (skb
&& audit_pid
) {
501 kauditd_send_unicast_skb(skb
);
502 skb
= skb_dequeue(&audit_hold_queue
);
506 * if auditd just disappeared but we
507 * dequeued an skb we need to drop ref
512 static int kauditd_thread(void *dummy
)
515 struct nlmsghdr
*nlh
;
518 while (!kthread_should_stop()) {
521 skb
= skb_dequeue(&audit_queue
);
523 nlh
= nlmsg_hdr(skb
);
525 /* if nlh->nlmsg_len is zero then we haven't attempted
526 * to send the message to userspace yet, if nlmsg_len
527 * is non-zero then we have attempted to send it to
528 * the multicast listeners as well as auditd; keep
529 * trying to send to auditd but don't repeat the
531 if (nlh
->nlmsg_len
== 0) {
532 nlh
->nlmsg_len
= skb
->len
;
533 kauditd_send_multicast_skb(skb
, GFP_KERNEL
);
535 /* see the note in kauditd_send_multicast_skb
536 * regarding the nlh->nlmsg_len value and why
537 * it differs between the multicast and unicast
539 nlh
->nlmsg_len
-= NLMSG_HDRLEN
;
543 kauditd_send_unicast_skb(skb
);
545 kauditd_printk_skb(skb
);
547 /* we have flushed the backlog so wake everyone up who
548 * is blocked and go to sleep until we have something
549 * in the backlog again */
550 wake_up(&audit_backlog_wait
);
551 wait_event_freezable(kauditd_wait
,
552 skb_queue_len(&audit_queue
));
558 int audit_send_list(void *_dest
)
560 struct audit_netlink_list
*dest
= _dest
;
562 struct net
*net
= dest
->net
;
563 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
565 /* wait for parent to finish and send an ACK */
566 mutex_lock(&audit_cmd_mutex
);
567 mutex_unlock(&audit_cmd_mutex
);
569 while ((skb
= __skb_dequeue(&dest
->q
)) != NULL
)
570 netlink_unicast(aunet
->nlsk
, skb
, dest
->portid
, 0);
578 struct sk_buff
*audit_make_reply(__u32 portid
, int seq
, int type
, int done
,
579 int multi
, const void *payload
, int size
)
582 struct nlmsghdr
*nlh
;
584 int flags
= multi
? NLM_F_MULTI
: 0;
585 int t
= done
? NLMSG_DONE
: type
;
587 skb
= nlmsg_new(size
, GFP_KERNEL
);
591 nlh
= nlmsg_put(skb
, portid
, seq
, t
, size
, flags
);
594 data
= nlmsg_data(nlh
);
595 memcpy(data
, payload
, size
);
603 static int audit_send_reply_thread(void *arg
)
605 struct audit_reply
*reply
= (struct audit_reply
*)arg
;
606 struct net
*net
= reply
->net
;
607 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
609 mutex_lock(&audit_cmd_mutex
);
610 mutex_unlock(&audit_cmd_mutex
);
612 /* Ignore failure. It'll only happen if the sender goes away,
613 because our timeout is set to infinite. */
614 netlink_unicast(aunet
->nlsk
, reply
->skb
, reply
->portid
, 0);
620 * audit_send_reply - send an audit reply message via netlink
621 * @request_skb: skb of request we are replying to (used to target the reply)
622 * @seq: sequence number
623 * @type: audit message type
624 * @done: done (last) flag
625 * @multi: multi-part message flag
626 * @payload: payload data
627 * @size: payload size
629 * Allocates an skb, builds the netlink message, and sends it to the port id.
630 * No failure notifications.
632 static void audit_send_reply(struct sk_buff
*request_skb
, int seq
, int type
, int done
,
633 int multi
, const void *payload
, int size
)
635 u32 portid
= NETLINK_CB(request_skb
).portid
;
636 struct net
*net
= sock_net(NETLINK_CB(request_skb
).sk
);
638 struct task_struct
*tsk
;
639 struct audit_reply
*reply
= kmalloc(sizeof(struct audit_reply
),
645 skb
= audit_make_reply(portid
, seq
, type
, done
, multi
, payload
, size
);
649 reply
->net
= get_net(net
);
650 reply
->portid
= portid
;
653 tsk
= kthread_run(audit_send_reply_thread
, reply
, "audit_send_reply");
662 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
665 static int audit_netlink_ok(struct sk_buff
*skb
, u16 msg_type
)
669 /* Only support initial user namespace for now. */
671 * We return ECONNREFUSED because it tricks userspace into thinking
672 * that audit was not configured into the kernel. Lots of users
673 * configure their PAM stack (because that's what the distro does)
674 * to reject login if unable to send messages to audit. If we return
675 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
676 * configured in and will let login proceed. If we return EPERM
677 * userspace will reject all logins. This should be removed when we
678 * support non init namespaces!!
680 if (current_user_ns() != &init_user_ns
)
681 return -ECONNREFUSED
;
690 case AUDIT_GET_FEATURE
:
691 case AUDIT_SET_FEATURE
:
692 case AUDIT_LIST_RULES
:
695 case AUDIT_SIGNAL_INFO
:
699 case AUDIT_MAKE_EQUIV
:
700 /* Only support auditd and auditctl in initial pid namespace
702 if (task_active_pid_ns(current
) != &init_pid_ns
)
705 if (!netlink_capable(skb
, CAP_AUDIT_CONTROL
))
709 case AUDIT_FIRST_USER_MSG
... AUDIT_LAST_USER_MSG
:
710 case AUDIT_FIRST_USER_MSG2
... AUDIT_LAST_USER_MSG2
:
711 if (!netlink_capable(skb
, CAP_AUDIT_WRITE
))
714 default: /* bad msg */
721 static void audit_log_common_recv_msg(struct audit_buffer
**ab
, u16 msg_type
)
723 uid_t uid
= from_kuid(&init_user_ns
, current_uid());
724 pid_t pid
= task_tgid_nr(current
);
726 if (!audit_enabled
&& msg_type
!= AUDIT_USER_AVC
) {
731 *ab
= audit_log_start(NULL
, GFP_KERNEL
, msg_type
);
734 audit_log_format(*ab
, "pid=%d uid=%u", pid
, uid
);
735 audit_log_session_info(*ab
);
736 audit_log_task_context(*ab
);
739 int is_audit_feature_set(int i
)
741 return af
.features
& AUDIT_FEATURE_TO_MASK(i
);
745 static int audit_get_feature(struct sk_buff
*skb
)
749 seq
= nlmsg_hdr(skb
)->nlmsg_seq
;
751 audit_send_reply(skb
, seq
, AUDIT_GET_FEATURE
, 0, 0, &af
, sizeof(af
));
756 static void audit_log_feature_change(int which
, u32 old_feature
, u32 new_feature
,
757 u32 old_lock
, u32 new_lock
, int res
)
759 struct audit_buffer
*ab
;
761 if (audit_enabled
== AUDIT_OFF
)
764 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_FEATURE_CHANGE
);
765 audit_log_task_info(ab
, current
);
766 audit_log_format(ab
, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
767 audit_feature_names
[which
], !!old_feature
, !!new_feature
,
768 !!old_lock
, !!new_lock
, res
);
772 static int audit_set_feature(struct sk_buff
*skb
)
774 struct audit_features
*uaf
;
777 BUILD_BUG_ON(AUDIT_LAST_FEATURE
+ 1 > ARRAY_SIZE(audit_feature_names
));
778 uaf
= nlmsg_data(nlmsg_hdr(skb
));
780 /* if there is ever a version 2 we should handle that here */
782 for (i
= 0; i
<= AUDIT_LAST_FEATURE
; i
++) {
783 u32 feature
= AUDIT_FEATURE_TO_MASK(i
);
784 u32 old_feature
, new_feature
, old_lock
, new_lock
;
786 /* if we are not changing this feature, move along */
787 if (!(feature
& uaf
->mask
))
790 old_feature
= af
.features
& feature
;
791 new_feature
= uaf
->features
& feature
;
792 new_lock
= (uaf
->lock
| af
.lock
) & feature
;
793 old_lock
= af
.lock
& feature
;
795 /* are we changing a locked feature? */
796 if (old_lock
&& (new_feature
!= old_feature
)) {
797 audit_log_feature_change(i
, old_feature
, new_feature
,
798 old_lock
, new_lock
, 0);
802 /* nothing invalid, do the changes */
803 for (i
= 0; i
<= AUDIT_LAST_FEATURE
; i
++) {
804 u32 feature
= AUDIT_FEATURE_TO_MASK(i
);
805 u32 old_feature
, new_feature
, old_lock
, new_lock
;
807 /* if we are not changing this feature, move along */
808 if (!(feature
& uaf
->mask
))
811 old_feature
= af
.features
& feature
;
812 new_feature
= uaf
->features
& feature
;
813 old_lock
= af
.lock
& feature
;
814 new_lock
= (uaf
->lock
| af
.lock
) & feature
;
816 if (new_feature
!= old_feature
)
817 audit_log_feature_change(i
, old_feature
, new_feature
,
818 old_lock
, new_lock
, 1);
821 af
.features
|= feature
;
823 af
.features
&= ~feature
;
830 static int audit_replace(pid_t pid
)
832 struct sk_buff
*skb
= audit_make_reply(0, 0, AUDIT_REPLACE
, 0, 0,
837 return netlink_unicast(audit_sock
, skb
, audit_nlk_portid
, 0);
840 static int audit_receive_msg(struct sk_buff
*skb
, struct nlmsghdr
*nlh
)
845 struct audit_buffer
*ab
;
846 u16 msg_type
= nlh
->nlmsg_type
;
847 struct audit_sig_info
*sig_data
;
851 err
= audit_netlink_ok(skb
, msg_type
);
855 seq
= nlh
->nlmsg_seq
;
856 data
= nlmsg_data(nlh
);
860 struct audit_status s
;
861 memset(&s
, 0, sizeof(s
));
862 s
.enabled
= audit_enabled
;
863 s
.failure
= audit_failure
;
865 s
.rate_limit
= audit_rate_limit
;
866 s
.backlog_limit
= audit_backlog_limit
;
867 s
.lost
= atomic_read(&audit_lost
);
868 s
.backlog
= skb_queue_len(&audit_queue
);
869 s
.feature_bitmap
= AUDIT_FEATURE_BITMAP_ALL
;
870 s
.backlog_wait_time
= audit_backlog_wait_time_master
;
871 audit_send_reply(skb
, seq
, AUDIT_GET
, 0, 0, &s
, sizeof(s
));
875 struct audit_status s
;
876 memset(&s
, 0, sizeof(s
));
877 /* guard against past and future API changes */
878 memcpy(&s
, data
, min_t(size_t, sizeof(s
), nlmsg_len(nlh
)));
879 if (s
.mask
& AUDIT_STATUS_ENABLED
) {
880 err
= audit_set_enabled(s
.enabled
);
884 if (s
.mask
& AUDIT_STATUS_FAILURE
) {
885 err
= audit_set_failure(s
.failure
);
889 if (s
.mask
& AUDIT_STATUS_PID
) {
891 pid_t requesting_pid
= task_tgid_vnr(current
);
893 if ((!new_pid
) && (requesting_pid
!= audit_pid
)) {
894 audit_log_config_change("audit_pid", new_pid
, audit_pid
, 0);
897 if (audit_pid
&& new_pid
&&
898 audit_replace(requesting_pid
) != -ECONNREFUSED
) {
899 audit_log_config_change("audit_pid", new_pid
, audit_pid
, 0);
902 if (audit_enabled
!= AUDIT_OFF
)
903 audit_log_config_change("audit_pid", new_pid
, audit_pid
, 1);
905 audit_nlk_portid
= NETLINK_CB(skb
).portid
;
906 audit_sock
= skb
->sk
;
908 if (s
.mask
& AUDIT_STATUS_RATE_LIMIT
) {
909 err
= audit_set_rate_limit(s
.rate_limit
);
913 if (s
.mask
& AUDIT_STATUS_BACKLOG_LIMIT
) {
914 err
= audit_set_backlog_limit(s
.backlog_limit
);
918 if (s
.mask
& AUDIT_STATUS_BACKLOG_WAIT_TIME
) {
919 if (sizeof(s
) > (size_t)nlh
->nlmsg_len
)
921 if (s
.backlog_wait_time
> 10*AUDIT_BACKLOG_WAIT_TIME
)
923 err
= audit_set_backlog_wait_time(s
.backlog_wait_time
);
929 case AUDIT_GET_FEATURE
:
930 err
= audit_get_feature(skb
);
934 case AUDIT_SET_FEATURE
:
935 err
= audit_set_feature(skb
);
940 case AUDIT_FIRST_USER_MSG
... AUDIT_LAST_USER_MSG
:
941 case AUDIT_FIRST_USER_MSG2
... AUDIT_LAST_USER_MSG2
:
942 if (!audit_enabled
&& msg_type
!= AUDIT_USER_AVC
)
945 err
= audit_filter(msg_type
, AUDIT_FILTER_USER
);
946 if (err
== 1) { /* match or error */
948 if (msg_type
== AUDIT_USER_TTY
) {
949 err
= tty_audit_push();
953 mutex_unlock(&audit_cmd_mutex
);
954 audit_log_common_recv_msg(&ab
, msg_type
);
955 if (msg_type
!= AUDIT_USER_TTY
)
956 audit_log_format(ab
, " msg='%.*s'",
957 AUDIT_MESSAGE_TEXT_MAX
,
962 audit_log_format(ab
, " data=");
963 size
= nlmsg_len(nlh
);
965 ((unsigned char *)data
)[size
- 1] == '\0')
967 audit_log_n_untrustedstring(ab
, data
, size
);
969 audit_set_portid(ab
, NETLINK_CB(skb
).portid
);
971 mutex_lock(&audit_cmd_mutex
);
976 if (nlmsg_len(nlh
) < sizeof(struct audit_rule_data
))
978 if (audit_enabled
== AUDIT_LOCKED
) {
979 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
980 audit_log_format(ab
, " audit_enabled=%d res=0", audit_enabled
);
984 err
= audit_rule_change(msg_type
, NETLINK_CB(skb
).portid
,
985 seq
, data
, nlmsg_len(nlh
));
987 case AUDIT_LIST_RULES
:
988 err
= audit_list_rules_send(skb
, seq
);
992 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
993 audit_log_format(ab
, " op=trim res=1");
996 case AUDIT_MAKE_EQUIV
: {
999 size_t msglen
= nlmsg_len(nlh
);
1003 if (msglen
< 2 * sizeof(u32
))
1005 memcpy(sizes
, bufp
, 2 * sizeof(u32
));
1006 bufp
+= 2 * sizeof(u32
);
1007 msglen
-= 2 * sizeof(u32
);
1008 old
= audit_unpack_string(&bufp
, &msglen
, sizes
[0]);
1013 new = audit_unpack_string(&bufp
, &msglen
, sizes
[1]);
1019 /* OK, here comes... */
1020 err
= audit_tag_tree(old
, new);
1022 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1024 audit_log_format(ab
, " op=make_equiv old=");
1025 audit_log_untrustedstring(ab
, old
);
1026 audit_log_format(ab
, " new=");
1027 audit_log_untrustedstring(ab
, new);
1028 audit_log_format(ab
, " res=%d", !err
);
1034 case AUDIT_SIGNAL_INFO
:
1036 if (audit_sig_sid
) {
1037 err
= security_secid_to_secctx(audit_sig_sid
, &ctx
, &len
);
1041 sig_data
= kmalloc(sizeof(*sig_data
) + len
, GFP_KERNEL
);
1044 security_release_secctx(ctx
, len
);
1047 sig_data
->uid
= from_kuid(&init_user_ns
, audit_sig_uid
);
1048 sig_data
->pid
= audit_sig_pid
;
1049 if (audit_sig_sid
) {
1050 memcpy(sig_data
->ctx
, ctx
, len
);
1051 security_release_secctx(ctx
, len
);
1053 audit_send_reply(skb
, seq
, AUDIT_SIGNAL_INFO
, 0, 0,
1054 sig_data
, sizeof(*sig_data
) + len
);
1057 case AUDIT_TTY_GET
: {
1058 struct audit_tty_status s
;
1061 t
= READ_ONCE(current
->signal
->audit_tty
);
1062 s
.enabled
= t
& AUDIT_TTY_ENABLE
;
1063 s
.log_passwd
= !!(t
& AUDIT_TTY_LOG_PASSWD
);
1065 audit_send_reply(skb
, seq
, AUDIT_TTY_GET
, 0, 0, &s
, sizeof(s
));
1068 case AUDIT_TTY_SET
: {
1069 struct audit_tty_status s
, old
;
1070 struct audit_buffer
*ab
;
1073 memset(&s
, 0, sizeof(s
));
1074 /* guard against past and future API changes */
1075 memcpy(&s
, data
, min_t(size_t, sizeof(s
), nlmsg_len(nlh
)));
1076 /* check if new data is valid */
1077 if ((s
.enabled
!= 0 && s
.enabled
!= 1) ||
1078 (s
.log_passwd
!= 0 && s
.log_passwd
!= 1))
1082 t
= READ_ONCE(current
->signal
->audit_tty
);
1084 t
= s
.enabled
| (-s
.log_passwd
& AUDIT_TTY_LOG_PASSWD
);
1085 t
= xchg(¤t
->signal
->audit_tty
, t
);
1087 old
.enabled
= t
& AUDIT_TTY_ENABLE
;
1088 old
.log_passwd
= !!(t
& AUDIT_TTY_LOG_PASSWD
);
1090 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1091 audit_log_format(ab
, " op=tty_set old-enabled=%d new-enabled=%d"
1092 " old-log_passwd=%d new-log_passwd=%d res=%d",
1093 old
.enabled
, s
.enabled
, old
.log_passwd
,
1094 s
.log_passwd
, !err
);
1103 return err
< 0 ? err
: 0;
1107 * Get message from skb. Each message is processed by audit_receive_msg.
1108 * Malformed skbs with wrong length are discarded silently.
1110 static void audit_receive_skb(struct sk_buff
*skb
)
1112 struct nlmsghdr
*nlh
;
1114 * len MUST be signed for nlmsg_next to be able to dec it below 0
1115 * if the nlmsg_len was not aligned
1120 nlh
= nlmsg_hdr(skb
);
1123 while (nlmsg_ok(nlh
, len
)) {
1124 err
= audit_receive_msg(skb
, nlh
);
1125 /* if err or if this message says it wants a response */
1126 if (err
|| (nlh
->nlmsg_flags
& NLM_F_ACK
))
1127 netlink_ack(skb
, nlh
, err
);
1129 nlh
= nlmsg_next(nlh
, &len
);
1133 /* Receive messages from netlink socket. */
1134 static void audit_receive(struct sk_buff
*skb
)
1136 mutex_lock(&audit_cmd_mutex
);
1137 audit_receive_skb(skb
);
1138 mutex_unlock(&audit_cmd_mutex
);
1141 /* Run custom bind function on netlink socket group connect or bind requests. */
1142 static int audit_bind(struct net
*net
, int group
)
1144 if (!capable(CAP_AUDIT_READ
))
1150 static int __net_init
audit_net_init(struct net
*net
)
1152 struct netlink_kernel_cfg cfg
= {
1153 .input
= audit_receive
,
1155 .flags
= NL_CFG_F_NONROOT_RECV
,
1156 .groups
= AUDIT_NLGRP_MAX
,
1159 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
1161 aunet
->nlsk
= netlink_kernel_create(net
, NETLINK_AUDIT
, &cfg
);
1162 if (aunet
->nlsk
== NULL
) {
1163 audit_panic("cannot initialize netlink socket in namespace");
1166 aunet
->nlsk
->sk_sndtimeo
= MAX_SCHEDULE_TIMEOUT
;
1170 static void __net_exit
audit_net_exit(struct net
*net
)
1172 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
1173 struct sock
*sock
= aunet
->nlsk
;
1174 if (sock
== audit_sock
) {
1179 RCU_INIT_POINTER(aunet
->nlsk
, NULL
);
1181 netlink_kernel_release(sock
);
1184 static struct pernet_operations audit_net_ops __net_initdata
= {
1185 .init
= audit_net_init
,
1186 .exit
= audit_net_exit
,
1187 .id
= &audit_net_id
,
1188 .size
= sizeof(struct audit_net
),
1191 /* Initialize audit support at boot time. */
1192 static int __init
audit_init(void)
1196 if (audit_initialized
== AUDIT_DISABLED
)
1199 pr_info("initializing netlink subsys (%s)\n",
1200 audit_default
? "enabled" : "disabled");
1201 register_pernet_subsys(&audit_net_ops
);
1203 skb_queue_head_init(&audit_queue
);
1204 skb_queue_head_init(&audit_hold_queue
);
1205 audit_initialized
= AUDIT_INITIALIZED
;
1206 audit_enabled
= audit_default
;
1207 audit_ever_enabled
|= !!audit_default
;
1209 for (i
= 0; i
< AUDIT_INODE_BUCKETS
; i
++)
1210 INIT_LIST_HEAD(&audit_inode_hash
[i
]);
1212 kauditd_task
= kthread_run(kauditd_thread
, NULL
, "kauditd");
1213 if (IS_ERR(kauditd_task
)) {
1214 int err
= PTR_ERR(kauditd_task
);
1215 panic("audit: failed to start the kauditd thread (%d)\n", err
);
1218 audit_log(NULL
, GFP_KERNEL
, AUDIT_KERNEL
, "initialized");
1222 __initcall(audit_init
);
1224 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1225 static int __init
audit_enable(char *str
)
1227 audit_default
= !!simple_strtol(str
, NULL
, 0);
1229 audit_initialized
= AUDIT_DISABLED
;
1231 pr_info("%s\n", audit_default
?
1232 "enabled (after initialization)" : "disabled (until reboot)");
1236 __setup("audit=", audit_enable
);
1238 /* Process kernel command-line parameter at boot time.
1239 * audit_backlog_limit=<n> */
1240 static int __init
audit_backlog_limit_set(char *str
)
1242 u32 audit_backlog_limit_arg
;
1244 pr_info("audit_backlog_limit: ");
1245 if (kstrtouint(str
, 0, &audit_backlog_limit_arg
)) {
1246 pr_cont("using default of %u, unable to parse %s\n",
1247 audit_backlog_limit
, str
);
1251 audit_backlog_limit
= audit_backlog_limit_arg
;
1252 pr_cont("%d\n", audit_backlog_limit
);
1256 __setup("audit_backlog_limit=", audit_backlog_limit_set
);
1258 static void audit_buffer_free(struct audit_buffer
*ab
)
1260 unsigned long flags
;
1266 spin_lock_irqsave(&audit_freelist_lock
, flags
);
1267 if (audit_freelist_count
> AUDIT_MAXFREE
)
1270 audit_freelist_count
++;
1271 list_add(&ab
->list
, &audit_freelist
);
1273 spin_unlock_irqrestore(&audit_freelist_lock
, flags
);
1276 static struct audit_buffer
* audit_buffer_alloc(struct audit_context
*ctx
,
1277 gfp_t gfp_mask
, int type
)
1279 unsigned long flags
;
1280 struct audit_buffer
*ab
= NULL
;
1281 struct nlmsghdr
*nlh
;
1283 spin_lock_irqsave(&audit_freelist_lock
, flags
);
1284 if (!list_empty(&audit_freelist
)) {
1285 ab
= list_entry(audit_freelist
.next
,
1286 struct audit_buffer
, list
);
1287 list_del(&ab
->list
);
1288 --audit_freelist_count
;
1290 spin_unlock_irqrestore(&audit_freelist_lock
, flags
);
1293 ab
= kmalloc(sizeof(*ab
), gfp_mask
);
1299 ab
->gfp_mask
= gfp_mask
;
1301 ab
->skb
= nlmsg_new(AUDIT_BUFSIZ
, gfp_mask
);
1305 nlh
= nlmsg_put(ab
->skb
, 0, 0, type
, 0, 0);
1315 audit_buffer_free(ab
);
1320 * audit_serial - compute a serial number for the audit record
1322 * Compute a serial number for the audit record. Audit records are
1323 * written to user-space as soon as they are generated, so a complete
1324 * audit record may be written in several pieces. The timestamp of the
1325 * record and this serial number are used by the user-space tools to
1326 * determine which pieces belong to the same audit record. The
1327 * (timestamp,serial) tuple is unique for each syscall and is live from
1328 * syscall entry to syscall exit.
1330 * NOTE: Another possibility is to store the formatted records off the
1331 * audit context (for those records that have a context), and emit them
1332 * all at syscall exit. However, this could delay the reporting of
1333 * significant errors until syscall exit (or never, if the system
1336 unsigned int audit_serial(void)
1338 static atomic_t serial
= ATOMIC_INIT(0);
1340 return atomic_add_return(1, &serial
);
1343 static inline void audit_get_stamp(struct audit_context
*ctx
,
1344 struct timespec
*t
, unsigned int *serial
)
1346 if (!ctx
|| !auditsc_get_stamp(ctx
, t
, serial
)) {
1348 *serial
= audit_serial();
1353 * Wait for auditd to drain the queue a little
1355 static long wait_for_auditd(long sleep_time
)
1357 DECLARE_WAITQUEUE(wait
, current
);
1359 if (audit_backlog_limit
&&
1360 skb_queue_len(&audit_queue
) > audit_backlog_limit
) {
1361 add_wait_queue_exclusive(&audit_backlog_wait
, &wait
);
1362 set_current_state(TASK_UNINTERRUPTIBLE
);
1363 sleep_time
= schedule_timeout(sleep_time
);
1364 remove_wait_queue(&audit_backlog_wait
, &wait
);
1371 * audit_log_start - obtain an audit buffer
1372 * @ctx: audit_context (may be NULL)
1373 * @gfp_mask: type of allocation
1374 * @type: audit message type
1376 * Returns audit_buffer pointer on success or NULL on error.
1378 * Obtain an audit buffer. This routine does locking to obtain the
1379 * audit buffer, but then no locking is required for calls to
1380 * audit_log_*format. If the task (ctx) is a task that is currently in a
1381 * syscall, then the syscall is marked as auditable and an audit record
1382 * will be written at syscall exit. If there is no associated task, then
1383 * task context (ctx) should be NULL.
1385 struct audit_buffer
*audit_log_start(struct audit_context
*ctx
, gfp_t gfp_mask
,
1388 struct audit_buffer
*ab
= NULL
;
1390 unsigned int uninitialized_var(serial
);
1391 int reserve
= 5; /* Allow atomic callers to go up to five
1392 entries over the normal backlog limit */
1393 unsigned long timeout_start
= jiffies
;
1395 if (audit_initialized
!= AUDIT_INITIALIZED
)
1398 if (unlikely(!audit_filter(type
, AUDIT_FILTER_TYPE
)))
1401 if (gfp_mask
& __GFP_DIRECT_RECLAIM
) {
1402 if (audit_pid
&& audit_pid
== current
->tgid
)
1403 gfp_mask
&= ~__GFP_DIRECT_RECLAIM
;
1408 while (audit_backlog_limit
1409 && skb_queue_len(&audit_queue
) > audit_backlog_limit
+ reserve
) {
1410 if (gfp_mask
& __GFP_DIRECT_RECLAIM
&& audit_backlog_wait_time
) {
1413 sleep_time
= timeout_start
+ audit_backlog_wait_time
- jiffies
;
1414 if (sleep_time
> 0) {
1415 sleep_time
= wait_for_auditd(sleep_time
);
1420 if (audit_rate_check() && printk_ratelimit())
1421 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1422 skb_queue_len(&audit_queue
),
1423 audit_backlog_limit
);
1424 audit_log_lost("backlog limit exceeded");
1425 audit_backlog_wait_time
= 0;
1426 wake_up(&audit_backlog_wait
);
1430 if (!reserve
&& !audit_backlog_wait_time
)
1431 audit_backlog_wait_time
= audit_backlog_wait_time_master
;
1433 ab
= audit_buffer_alloc(ctx
, gfp_mask
, type
);
1435 audit_log_lost("out of memory in audit_log_start");
1439 audit_get_stamp(ab
->ctx
, &t
, &serial
);
1441 audit_log_format(ab
, "audit(%lu.%03lu:%u): ",
1442 t
.tv_sec
, t
.tv_nsec
/1000000, serial
);
1447 * audit_expand - expand skb in the audit buffer
1449 * @extra: space to add at tail of the skb
1451 * Returns 0 (no space) on failed expansion, or available space if
1454 static inline int audit_expand(struct audit_buffer
*ab
, int extra
)
1456 struct sk_buff
*skb
= ab
->skb
;
1457 int oldtail
= skb_tailroom(skb
);
1458 int ret
= pskb_expand_head(skb
, 0, extra
, ab
->gfp_mask
);
1459 int newtail
= skb_tailroom(skb
);
1462 audit_log_lost("out of memory in audit_expand");
1466 skb
->truesize
+= newtail
- oldtail
;
1471 * Format an audit message into the audit buffer. If there isn't enough
1472 * room in the audit buffer, more room will be allocated and vsnprint
1473 * will be called a second time. Currently, we assume that a printk
1474 * can't format message larger than 1024 bytes, so we don't either.
1476 static void audit_log_vformat(struct audit_buffer
*ab
, const char *fmt
,
1480 struct sk_buff
*skb
;
1488 avail
= skb_tailroom(skb
);
1490 avail
= audit_expand(ab
, AUDIT_BUFSIZ
);
1494 va_copy(args2
, args
);
1495 len
= vsnprintf(skb_tail_pointer(skb
), avail
, fmt
, args
);
1497 /* The printk buffer is 1024 bytes long, so if we get
1498 * here and AUDIT_BUFSIZ is at least 1024, then we can
1499 * log everything that printk could have logged. */
1500 avail
= audit_expand(ab
,
1501 max_t(unsigned, AUDIT_BUFSIZ
, 1+len
-avail
));
1504 len
= vsnprintf(skb_tail_pointer(skb
), avail
, fmt
, args2
);
1515 * audit_log_format - format a message into the audit buffer.
1517 * @fmt: format string
1518 * @...: optional parameters matching @fmt string
1520 * All the work is done in audit_log_vformat.
1522 void audit_log_format(struct audit_buffer
*ab
, const char *fmt
, ...)
1528 va_start(args
, fmt
);
1529 audit_log_vformat(ab
, fmt
, args
);
1534 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1535 * @ab: the audit_buffer
1536 * @buf: buffer to convert to hex
1537 * @len: length of @buf to be converted
1539 * No return value; failure to expand is silently ignored.
1541 * This function will take the passed buf and convert it into a string of
1542 * ascii hex digits. The new string is placed onto the skb.
1544 void audit_log_n_hex(struct audit_buffer
*ab
, const unsigned char *buf
,
1547 int i
, avail
, new_len
;
1549 struct sk_buff
*skb
;
1556 avail
= skb_tailroom(skb
);
1558 if (new_len
>= avail
) {
1559 /* Round the buffer request up to the next multiple */
1560 new_len
= AUDIT_BUFSIZ
*(((new_len
-avail
)/AUDIT_BUFSIZ
) + 1);
1561 avail
= audit_expand(ab
, new_len
);
1566 ptr
= skb_tail_pointer(skb
);
1567 for (i
= 0; i
< len
; i
++)
1568 ptr
= hex_byte_pack_upper(ptr
, buf
[i
]);
1570 skb_put(skb
, len
<< 1); /* new string is twice the old string */
1574 * Format a string of no more than slen characters into the audit buffer,
1575 * enclosed in quote marks.
1577 void audit_log_n_string(struct audit_buffer
*ab
, const char *string
,
1582 struct sk_buff
*skb
;
1589 avail
= skb_tailroom(skb
);
1590 new_len
= slen
+ 3; /* enclosing quotes + null terminator */
1591 if (new_len
> avail
) {
1592 avail
= audit_expand(ab
, new_len
);
1596 ptr
= skb_tail_pointer(skb
);
1598 memcpy(ptr
, string
, slen
);
1602 skb_put(skb
, slen
+ 2); /* don't include null terminator */
1606 * audit_string_contains_control - does a string need to be logged in hex
1607 * @string: string to be checked
1608 * @len: max length of the string to check
1610 bool audit_string_contains_control(const char *string
, size_t len
)
1612 const unsigned char *p
;
1613 for (p
= string
; p
< (const unsigned char *)string
+ len
; p
++) {
1614 if (*p
== '"' || *p
< 0x21 || *p
> 0x7e)
1621 * audit_log_n_untrustedstring - log a string that may contain random characters
1623 * @len: length of string (not including trailing null)
1624 * @string: string to be logged
1626 * This code will escape a string that is passed to it if the string
1627 * contains a control character, unprintable character, double quote mark,
1628 * or a space. Unescaped strings will start and end with a double quote mark.
1629 * Strings that are escaped are printed in hex (2 digits per char).
1631 * The caller specifies the number of characters in the string to log, which may
1632 * or may not be the entire string.
1634 void audit_log_n_untrustedstring(struct audit_buffer
*ab
, const char *string
,
1637 if (audit_string_contains_control(string
, len
))
1638 audit_log_n_hex(ab
, string
, len
);
1640 audit_log_n_string(ab
, string
, len
);
1644 * audit_log_untrustedstring - log a string that may contain random characters
1646 * @string: string to be logged
1648 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1649 * determine string length.
1651 void audit_log_untrustedstring(struct audit_buffer
*ab
, const char *string
)
1653 audit_log_n_untrustedstring(ab
, string
, strlen(string
));
1656 /* This is a helper-function to print the escaped d_path */
1657 void audit_log_d_path(struct audit_buffer
*ab
, const char *prefix
,
1658 const struct path
*path
)
1663 audit_log_format(ab
, "%s", prefix
);
1665 /* We will allow 11 spaces for ' (deleted)' to be appended */
1666 pathname
= kmalloc(PATH_MAX
+11, ab
->gfp_mask
);
1668 audit_log_string(ab
, "<no_memory>");
1671 p
= d_path(path
, pathname
, PATH_MAX
+11);
1672 if (IS_ERR(p
)) { /* Should never happen since we send PATH_MAX */
1673 /* FIXME: can we save some information here? */
1674 audit_log_string(ab
, "<too_long>");
1676 audit_log_untrustedstring(ab
, p
);
1680 void audit_log_session_info(struct audit_buffer
*ab
)
1682 unsigned int sessionid
= audit_get_sessionid(current
);
1683 uid_t auid
= from_kuid(&init_user_ns
, audit_get_loginuid(current
));
1685 audit_log_format(ab
, " auid=%u ses=%u", auid
, sessionid
);
1688 void audit_log_key(struct audit_buffer
*ab
, char *key
)
1690 audit_log_format(ab
, " key=");
1692 audit_log_untrustedstring(ab
, key
);
1694 audit_log_format(ab
, "(null)");
1697 void audit_log_cap(struct audit_buffer
*ab
, char *prefix
, kernel_cap_t
*cap
)
1701 audit_log_format(ab
, " %s=", prefix
);
1702 CAP_FOR_EACH_U32(i
) {
1703 audit_log_format(ab
, "%08x",
1704 cap
->cap
[CAP_LAST_U32
- i
]);
1708 static void audit_log_fcaps(struct audit_buffer
*ab
, struct audit_names
*name
)
1710 kernel_cap_t
*perm
= &name
->fcap
.permitted
;
1711 kernel_cap_t
*inh
= &name
->fcap
.inheritable
;
1714 if (!cap_isclear(*perm
)) {
1715 audit_log_cap(ab
, "cap_fp", perm
);
1718 if (!cap_isclear(*inh
)) {
1719 audit_log_cap(ab
, "cap_fi", inh
);
1724 audit_log_format(ab
, " cap_fe=%d cap_fver=%x",
1725 name
->fcap
.fE
, name
->fcap_ver
);
1728 static inline int audit_copy_fcaps(struct audit_names
*name
,
1729 const struct dentry
*dentry
)
1731 struct cpu_vfs_cap_data caps
;
1737 rc
= get_vfs_caps_from_disk(dentry
, &caps
);
1741 name
->fcap
.permitted
= caps
.permitted
;
1742 name
->fcap
.inheritable
= caps
.inheritable
;
1743 name
->fcap
.fE
= !!(caps
.magic_etc
& VFS_CAP_FLAGS_EFFECTIVE
);
1744 name
->fcap_ver
= (caps
.magic_etc
& VFS_CAP_REVISION_MASK
) >>
1745 VFS_CAP_REVISION_SHIFT
;
1750 /* Copy inode data into an audit_names. */
1751 void audit_copy_inode(struct audit_names
*name
, const struct dentry
*dentry
,
1752 struct inode
*inode
)
1754 name
->ino
= inode
->i_ino
;
1755 name
->dev
= inode
->i_sb
->s_dev
;
1756 name
->mode
= inode
->i_mode
;
1757 name
->uid
= inode
->i_uid
;
1758 name
->gid
= inode
->i_gid
;
1759 name
->rdev
= inode
->i_rdev
;
1760 security_inode_getsecid(inode
, &name
->osid
);
1761 audit_copy_fcaps(name
, dentry
);
1765 * audit_log_name - produce AUDIT_PATH record from struct audit_names
1766 * @context: audit_context for the task
1767 * @n: audit_names structure with reportable details
1768 * @path: optional path to report instead of audit_names->name
1769 * @record_num: record number to report when handling a list of names
1770 * @call_panic: optional pointer to int that will be updated if secid fails
1772 void audit_log_name(struct audit_context
*context
, struct audit_names
*n
,
1773 struct path
*path
, int record_num
, int *call_panic
)
1775 struct audit_buffer
*ab
;
1776 ab
= audit_log_start(context
, GFP_KERNEL
, AUDIT_PATH
);
1780 audit_log_format(ab
, "item=%d", record_num
);
1783 audit_log_d_path(ab
, " name=", path
);
1785 switch (n
->name_len
) {
1786 case AUDIT_NAME_FULL
:
1787 /* log the full path */
1788 audit_log_format(ab
, " name=");
1789 audit_log_untrustedstring(ab
, n
->name
->name
);
1792 /* name was specified as a relative path and the
1793 * directory component is the cwd */
1794 audit_log_d_path(ab
, " name=", &context
->pwd
);
1797 /* log the name's directory component */
1798 audit_log_format(ab
, " name=");
1799 audit_log_n_untrustedstring(ab
, n
->name
->name
,
1803 audit_log_format(ab
, " name=(null)");
1805 if (n
->ino
!= AUDIT_INO_UNSET
)
1806 audit_log_format(ab
, " inode=%lu"
1807 " dev=%02x:%02x mode=%#ho"
1808 " ouid=%u ogid=%u rdev=%02x:%02x",
1813 from_kuid(&init_user_ns
, n
->uid
),
1814 from_kgid(&init_user_ns
, n
->gid
),
1820 if (security_secid_to_secctx(
1821 n
->osid
, &ctx
, &len
)) {
1822 audit_log_format(ab
, " osid=%u", n
->osid
);
1826 audit_log_format(ab
, " obj=%s", ctx
);
1827 security_release_secctx(ctx
, len
);
1831 /* log the audit_names record type */
1832 audit_log_format(ab
, " nametype=");
1834 case AUDIT_TYPE_NORMAL
:
1835 audit_log_format(ab
, "NORMAL");
1837 case AUDIT_TYPE_PARENT
:
1838 audit_log_format(ab
, "PARENT");
1840 case AUDIT_TYPE_CHILD_DELETE
:
1841 audit_log_format(ab
, "DELETE");
1843 case AUDIT_TYPE_CHILD_CREATE
:
1844 audit_log_format(ab
, "CREATE");
1847 audit_log_format(ab
, "UNKNOWN");
1851 audit_log_fcaps(ab
, n
);
1855 int audit_log_task_context(struct audit_buffer
*ab
)
1862 security_task_getsecid(current
, &sid
);
1866 error
= security_secid_to_secctx(sid
, &ctx
, &len
);
1868 if (error
!= -EINVAL
)
1873 audit_log_format(ab
, " subj=%s", ctx
);
1874 security_release_secctx(ctx
, len
);
1878 audit_panic("error in audit_log_task_context");
1881 EXPORT_SYMBOL(audit_log_task_context
);
1883 void audit_log_d_path_exe(struct audit_buffer
*ab
,
1884 struct mm_struct
*mm
)
1886 struct file
*exe_file
;
1891 exe_file
= get_mm_exe_file(mm
);
1895 audit_log_d_path(ab
, " exe=", &exe_file
->f_path
);
1899 audit_log_format(ab
, " exe=(null)");
1902 struct tty_struct
*audit_get_tty(struct task_struct
*tsk
)
1904 struct tty_struct
*tty
= NULL
;
1905 unsigned long flags
;
1907 spin_lock_irqsave(&tsk
->sighand
->siglock
, flags
);
1909 tty
= tty_kref_get(tsk
->signal
->tty
);
1910 spin_unlock_irqrestore(&tsk
->sighand
->siglock
, flags
);
1914 void audit_put_tty(struct tty_struct
*tty
)
1919 void audit_log_task_info(struct audit_buffer
*ab
, struct task_struct
*tsk
)
1921 const struct cred
*cred
;
1922 char comm
[sizeof(tsk
->comm
)];
1923 struct tty_struct
*tty
;
1928 /* tsk == current */
1929 cred
= current_cred();
1930 tty
= audit_get_tty(tsk
);
1931 audit_log_format(ab
,
1932 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
1933 " euid=%u suid=%u fsuid=%u"
1934 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1937 from_kuid(&init_user_ns
, audit_get_loginuid(tsk
)),
1938 from_kuid(&init_user_ns
, cred
->uid
),
1939 from_kgid(&init_user_ns
, cred
->gid
),
1940 from_kuid(&init_user_ns
, cred
->euid
),
1941 from_kuid(&init_user_ns
, cred
->suid
),
1942 from_kuid(&init_user_ns
, cred
->fsuid
),
1943 from_kgid(&init_user_ns
, cred
->egid
),
1944 from_kgid(&init_user_ns
, cred
->sgid
),
1945 from_kgid(&init_user_ns
, cred
->fsgid
),
1946 tty
? tty_name(tty
) : "(none)",
1947 audit_get_sessionid(tsk
));
1949 audit_log_format(ab
, " comm=");
1950 audit_log_untrustedstring(ab
, get_task_comm(comm
, tsk
));
1951 audit_log_d_path_exe(ab
, tsk
->mm
);
1952 audit_log_task_context(ab
);
1954 EXPORT_SYMBOL(audit_log_task_info
);
1957 * audit_log_link_denied - report a link restriction denial
1958 * @operation: specific link operation
1959 * @link: the path that triggered the restriction
1961 void audit_log_link_denied(const char *operation
, struct path
*link
)
1963 struct audit_buffer
*ab
;
1964 struct audit_names
*name
;
1966 name
= kzalloc(sizeof(*name
), GFP_NOFS
);
1970 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
1971 ab
= audit_log_start(current
->audit_context
, GFP_KERNEL
,
1975 audit_log_format(ab
, "op=%s", operation
);
1976 audit_log_task_info(ab
, current
);
1977 audit_log_format(ab
, " res=0");
1980 /* Generate AUDIT_PATH record with object. */
1981 name
->type
= AUDIT_TYPE_NORMAL
;
1982 audit_copy_inode(name
, link
->dentry
, d_backing_inode(link
->dentry
));
1983 audit_log_name(current
->audit_context
, name
, link
, 0, NULL
);
1989 * audit_log_end - end one audit record
1990 * @ab: the audit_buffer
1992 * We can not do a netlink send inside an irq context because it blocks (last
1993 * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
1994 * queue and a tasklet is scheduled to remove them from the queue outside the
1995 * irq context. May be called in any context.
1997 void audit_log_end(struct audit_buffer
*ab
)
2001 if (!audit_rate_check()) {
2002 audit_log_lost("rate limit exceeded");
2004 skb_queue_tail(&audit_queue
, ab
->skb
);
2005 wake_up_interruptible(&kauditd_wait
);
2008 audit_buffer_free(ab
);
2012 * audit_log - Log an audit record
2013 * @ctx: audit context
2014 * @gfp_mask: type of allocation
2015 * @type: audit message type
2016 * @fmt: format string to use
2017 * @...: variable parameters matching the format string
2019 * This is a convenience function that calls audit_log_start,
2020 * audit_log_vformat, and audit_log_end. It may be called
2023 void audit_log(struct audit_context
*ctx
, gfp_t gfp_mask
, int type
,
2024 const char *fmt
, ...)
2026 struct audit_buffer
*ab
;
2029 ab
= audit_log_start(ctx
, gfp_mask
, type
);
2031 va_start(args
, fmt
);
2032 audit_log_vformat(ab
, fmt
, args
);
2038 #ifdef CONFIG_SECURITY
2040 * audit_log_secctx - Converts and logs SELinux context
2042 * @secid: security number
2044 * This is a helper function that calls security_secid_to_secctx to convert
2045 * secid to secctx and then adds the (converted) SELinux context to the audit
2046 * log by calling audit_log_format, thus also preventing leak of internal secid
2047 * to userspace. If secid cannot be converted audit_panic is called.
2049 void audit_log_secctx(struct audit_buffer
*ab
, u32 secid
)
2054 if (security_secid_to_secctx(secid
, &secctx
, &len
)) {
2055 audit_panic("Cannot convert secid to context");
2057 audit_log_format(ab
, " obj=%s", secctx
);
2058 security_release_secctx(secctx
, len
);
2061 EXPORT_SYMBOL(audit_log_secctx
);
2064 EXPORT_SYMBOL(audit_log_start
);
2065 EXPORT_SYMBOL(audit_log_end
);
2066 EXPORT_SYMBOL(audit_log_format
);
2067 EXPORT_SYMBOL(audit_log
);