projects/linux·blob v5.0-rc3 · refs

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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
4 *
5 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
6 * All Rights Reserved.
7 *
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.
12 *
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.
17 *
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
21 *
22 * Written by Rickard E. (Rik) Faith <[email protected]>
23 *
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
29 * generation time):
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
36 * current syscall).
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.
40 *
41 * Audit userspace, documentation, tests, and bug/issue trackers:
42 * https://github.com/linux-audit
43 */
44
45#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46
47#include <linux/file.h>
48#include <linux/init.h>
49#include <linux/types.h>
50#include <linux/atomic.h>
51#include <linux/mm.h>
52#include <linux/export.h>
53#include <linux/slab.h>
54#include <linux/err.h>
55#include <linux/kthread.h>
56#include <linux/kernel.h>
57#include <linux/syscalls.h>
58#include <linux/spinlock.h>
59#include <linux/rcupdate.h>
60#include <linux/mutex.h>
61#include <linux/gfp.h>
62#include <linux/pid.h>
63
64#include <linux/audit.h>
65
66#include <net/sock.h>
67#include <net/netlink.h>
68#include <linux/skbuff.h>
69#ifdef CONFIG_SECURITY
70#include <linux/security.h>
71#endif
72#include <linux/freezer.h>
73#include <linux/pid_namespace.h>
74#include <net/netns/generic.h>
75
76#include "audit.h"
77
78/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
79 * (Initialization happens after skb_init is called.) */
80#define AUDIT_DISABLED -1
81#define AUDIT_UNINITIALIZED 0
82#define AUDIT_INITIALIZED 1
83static int audit_initialized;
84
85u32 audit_enabled = AUDIT_OFF;
86bool audit_ever_enabled = !!AUDIT_OFF;
87
88EXPORT_SYMBOL_GPL(audit_enabled);
89
90/* Default state when kernel boots without any parameters. */
91static u32 audit_default = AUDIT_OFF;
92
93/* If auditing cannot proceed, audit_failure selects what happens. */
94static u32 audit_failure = AUDIT_FAIL_PRINTK;
95
96/* private audit network namespace index */
97static unsigned int audit_net_id;
98
99/**
100 * struct audit_net - audit private network namespace data
101 * @sk: communication socket
102 */
103struct audit_net {
104 struct sock *sk;
105};
106
107/**
108 * struct auditd_connection - kernel/auditd connection state
109 * @pid: auditd PID
110 * @portid: netlink portid
111 * @net: the associated network namespace
112 * @rcu: RCU head
113 *
114 * Description:
115 * This struct is RCU protected; you must either hold the RCU lock for reading
116 * or the associated spinlock for writing.
117 */
118static struct auditd_connection {
119 struct pid *pid;
120 u32 portid;
121 struct net *net;
122 struct rcu_head rcu;
123} *auditd_conn = NULL;
124static DEFINE_SPINLOCK(auditd_conn_lock);
125
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. */
129static u32 audit_rate_limit;
130
131/* Number of outstanding audit_buffers allowed.
132 * When set to zero, this means unlimited. */
133static u32 audit_backlog_limit = 64;
134#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
135static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
136
137/* The identity of the user shutting down the audit system. */
138kuid_t audit_sig_uid = INVALID_UID;
139pid_t audit_sig_pid = -1;
140u32 audit_sig_sid = 0;
141
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
148*/
149static atomic_t audit_lost = ATOMIC_INIT(0);
150
151/* Hash for inode-based rules */
152struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
153
154static struct kmem_cache *audit_buffer_cache;
155
156/* queue msgs to send via kauditd_task */
157static struct sk_buff_head audit_queue;
158/* queue msgs due to temporary unicast send problems */
159static struct sk_buff_head audit_retry_queue;
160/* queue msgs waiting for new auditd connection */
161static struct sk_buff_head audit_hold_queue;
162
163/* queue servicing thread */
164static struct task_struct *kauditd_task;
165static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
166
167/* waitqueue for callers who are blocked on the audit backlog */
168static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
169
170static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
171 .mask = -1,
172 .features = 0,
173 .lock = 0,};
174
175static char *audit_feature_names[2] = {
176 "only_unset_loginuid",
177 "loginuid_immutable",
178};
179
180/**
181 * struct audit_ctl_mutex - serialize requests from userspace
182 * @lock: the mutex used for locking
183 * @owner: the task which owns the lock
184 *
185 * Description:
186 * This is the lock struct used to ensure we only process userspace requests
187 * in an orderly fashion. We can't simply use a mutex/lock here because we
188 * need to track lock ownership so we don't end up blocking the lock owner in
189 * audit_log_start() or similar.
190 */
191static struct audit_ctl_mutex {
192 struct mutex lock;
193 void *owner;
194} audit_cmd_mutex;
195
196/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
197 * audit records. Since printk uses a 1024 byte buffer, this buffer
198 * should be at least that large. */
199#define AUDIT_BUFSIZ 1024
200
201/* The audit_buffer is used when formatting an audit record. The caller
202 * locks briefly to get the record off the freelist or to allocate the
203 * buffer, and locks briefly to send the buffer to the netlink layer or
204 * to place it on a transmit queue. Multiple audit_buffers can be in
205 * use simultaneously. */
206struct audit_buffer {
207 struct sk_buff *skb; /* formatted skb ready to send */
208 struct audit_context *ctx; /* NULL or associated context */
209 gfp_t gfp_mask;
210};
211
212struct audit_reply {
213 __u32 portid;
214 struct net *net;
215 struct sk_buff *skb;
216};
217
218/**
219 * auditd_test_task - Check to see if a given task is an audit daemon
220 * @task: the task to check
221 *
222 * Description:
223 * Return 1 if the task is a registered audit daemon, 0 otherwise.
224 */
225int auditd_test_task(struct task_struct *task)
226{
227 int rc;
228 struct auditd_connection *ac;
229
230 rcu_read_lock();
231 ac = rcu_dereference(auditd_conn);
232 rc = (ac && ac->pid == task_tgid(task) ? 1 : 0);
233 rcu_read_unlock();
234
235 return rc;
236}
237
238/**
239 * audit_ctl_lock - Take the audit control lock
240 */
241void audit_ctl_lock(void)
242{
243 mutex_lock(&audit_cmd_mutex.lock);
244 audit_cmd_mutex.owner = current;
245}
246
247/**
248 * audit_ctl_unlock - Drop the audit control lock
249 */
250void audit_ctl_unlock(void)
251{
252 audit_cmd_mutex.owner = NULL;
253 mutex_unlock(&audit_cmd_mutex.lock);
254}
255
256/**
257 * audit_ctl_owner_current - Test to see if the current task owns the lock
258 *
259 * Description:
260 * Return true if the current task owns the audit control lock, false if it
261 * doesn't own the lock.
262 */
263static bool audit_ctl_owner_current(void)
264{
265 return (current == audit_cmd_mutex.owner);
266}
267
268/**
269 * auditd_pid_vnr - Return the auditd PID relative to the namespace
270 *
271 * Description:
272 * Returns the PID in relation to the namespace, 0 on failure.
273 */
274static pid_t auditd_pid_vnr(void)
275{
276 pid_t pid;
277 const struct auditd_connection *ac;
278
279 rcu_read_lock();
280 ac = rcu_dereference(auditd_conn);
281 if (!ac || !ac->pid)
282 pid = 0;
283 else
284 pid = pid_vnr(ac->pid);
285 rcu_read_unlock();
286
287 return pid;
288}
289
290/**
291 * audit_get_sk - Return the audit socket for the given network namespace
292 * @net: the destination network namespace
293 *
294 * Description:
295 * Returns the sock pointer if valid, NULL otherwise. The caller must ensure
296 * that a reference is held for the network namespace while the sock is in use.
297 */
298static struct sock *audit_get_sk(const struct net *net)
299{
300 struct audit_net *aunet;
301
302 if (!net)
303 return NULL;
304
305 aunet = net_generic(net, audit_net_id);
306 return aunet->sk;
307}
308
309void audit_panic(const char *message)
310{
311 switch (audit_failure) {
312 case AUDIT_FAIL_SILENT:
313 break;
314 case AUDIT_FAIL_PRINTK:
315 if (printk_ratelimit())
316 pr_err("%s\n", message);
317 break;
318 case AUDIT_FAIL_PANIC:
319 panic("audit: %s\n", message);
320 break;
321 }
322}
323
324static inline int audit_rate_check(void)
325{
326 static unsigned long last_check = 0;
327 static int messages = 0;
328 static DEFINE_SPINLOCK(lock);
329 unsigned long flags;
330 unsigned long now;
331 unsigned long elapsed;
332 int retval = 0;
333
334 if (!audit_rate_limit) return 1;
335
336 spin_lock_irqsave(&lock, flags);
337 if (++messages < audit_rate_limit) {
338 retval = 1;
339 } else {
340 now = jiffies;
341 elapsed = now - last_check;
342 if (elapsed > HZ) {
343 last_check = now;
344 messages = 0;
345 retval = 1;
346 }
347 }
348 spin_unlock_irqrestore(&lock, flags);
349
350 return retval;
351}
352
353/**
354 * audit_log_lost - conditionally log lost audit message event
355 * @message: the message stating reason for lost audit message
356 *
357 * Emit at least 1 message per second, even if audit_rate_check is
358 * throttling.
359 * Always increment the lost messages counter.
360*/
361void audit_log_lost(const char *message)
362{
363 static unsigned long last_msg = 0;
364 static DEFINE_SPINLOCK(lock);
365 unsigned long flags;
366 unsigned long now;
367 int print;
368
369 atomic_inc(&audit_lost);
370
371 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
372
373 if (!print) {
374 spin_lock_irqsave(&lock, flags);
375 now = jiffies;
376 if (now - last_msg > HZ) {
377 print = 1;
378 last_msg = now;
379 }
380 spin_unlock_irqrestore(&lock, flags);
381 }
382
383 if (print) {
384 if (printk_ratelimit())
385 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
386 atomic_read(&audit_lost),
387 audit_rate_limit,
388 audit_backlog_limit);
389 audit_panic(message);
390 }
391}
392
393static int audit_log_config_change(char *function_name, u32 new, u32 old,
394 int allow_changes)
395{
396 struct audit_buffer *ab;
397 int rc = 0;
398
399 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
400 if (unlikely(!ab))
401 return rc;
402 audit_log_format(ab, "%s=%u old=%u ", function_name, new, old);
403 audit_log_session_info(ab);
404 rc = audit_log_task_context(ab);
405 if (rc)
406 allow_changes = 0; /* Something weird, deny request */
407 audit_log_format(ab, " res=%d", allow_changes);
408 audit_log_end(ab);
409 return rc;
410}
411
412static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
413{
414 int allow_changes, rc = 0;
415 u32 old = *to_change;
416
417 /* check if we are locked */
418 if (audit_enabled == AUDIT_LOCKED)
419 allow_changes = 0;
420 else
421 allow_changes = 1;
422
423 if (audit_enabled != AUDIT_OFF) {
424 rc = audit_log_config_change(function_name, new, old, allow_changes);
425 if (rc)
426 allow_changes = 0;
427 }
428
429 /* If we are allowed, make the change */
430 if (allow_changes == 1)
431 *to_change = new;
432 /* Not allowed, update reason */
433 else if (rc == 0)
434 rc = -EPERM;
435 return rc;
436}
437
438static int audit_set_rate_limit(u32 limit)
439{
440 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
441}
442
443static int audit_set_backlog_limit(u32 limit)
444{
445 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
446}
447
448static int audit_set_backlog_wait_time(u32 timeout)
449{
450 return audit_do_config_change("audit_backlog_wait_time",
451 &audit_backlog_wait_time, timeout);
452}
453
454static int audit_set_enabled(u32 state)
455{
456 int rc;
457 if (state > AUDIT_LOCKED)
458 return -EINVAL;
459
460 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
461 if (!rc)
462 audit_ever_enabled |= !!state;
463
464 return rc;
465}
466
467static int audit_set_failure(u32 state)
468{
469 if (state != AUDIT_FAIL_SILENT
470 && state != AUDIT_FAIL_PRINTK
471 && state != AUDIT_FAIL_PANIC)
472 return -EINVAL;
473
474 return audit_do_config_change("audit_failure", &audit_failure, state);
475}
476
477/**
478 * auditd_conn_free - RCU helper to release an auditd connection struct
479 * @rcu: RCU head
480 *
481 * Description:
482 * Drop any references inside the auditd connection tracking struct and free
483 * the memory.
484 */
485static void auditd_conn_free(struct rcu_head *rcu)
486{
487 struct auditd_connection *ac;
488
489 ac = container_of(rcu, struct auditd_connection, rcu);
490 put_pid(ac->pid);
491 put_net(ac->net);
492 kfree(ac);
493}
494
495/**
496 * auditd_set - Set/Reset the auditd connection state
497 * @pid: auditd PID
498 * @portid: auditd netlink portid
499 * @net: auditd network namespace pointer
500 *
501 * Description:
502 * This function will obtain and drop network namespace references as
503 * necessary. Returns zero on success, negative values on failure.
504 */
505static int auditd_set(struct pid *pid, u32 portid, struct net *net)
506{
507 unsigned long flags;
508 struct auditd_connection *ac_old, *ac_new;
509
510 if (!pid || !net)
511 return -EINVAL;
512
513 ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL);
514 if (!ac_new)
515 return -ENOMEM;
516 ac_new->pid = get_pid(pid);
517 ac_new->portid = portid;
518 ac_new->net = get_net(net);
519
520 spin_lock_irqsave(&auditd_conn_lock, flags);
521 ac_old = rcu_dereference_protected(auditd_conn,
522 lockdep_is_held(&auditd_conn_lock));
523 rcu_assign_pointer(auditd_conn, ac_new);
524 spin_unlock_irqrestore(&auditd_conn_lock, flags);
525
526 if (ac_old)
527 call_rcu(&ac_old->rcu, auditd_conn_free);
528
529 return 0;
530}
531
532/**
533 * kauditd_print_skb - Print the audit record to the ring buffer
534 * @skb: audit record
535 *
536 * Whatever the reason, this packet may not make it to the auditd connection
537 * so write it via printk so the information isn't completely lost.
538 */
539static void kauditd_printk_skb(struct sk_buff *skb)
540{
541 struct nlmsghdr *nlh = nlmsg_hdr(skb);
542 char *data = nlmsg_data(nlh);
543
544 if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit())
545 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
546}
547
548/**
549 * kauditd_rehold_skb - Handle a audit record send failure in the hold queue
550 * @skb: audit record
551 *
552 * Description:
553 * This should only be used by the kauditd_thread when it fails to flush the
554 * hold queue.
555 */
556static void kauditd_rehold_skb(struct sk_buff *skb)
557{
558 /* put the record back in the queue at the same place */
559 skb_queue_head(&audit_hold_queue, skb);
560}
561
562/**
563 * kauditd_hold_skb - Queue an audit record, waiting for auditd
564 * @skb: audit record
565 *
566 * Description:
567 * Queue the audit record, waiting for an instance of auditd. When this
568 * function is called we haven't given up yet on sending the record, but things
569 * are not looking good. The first thing we want to do is try to write the
570 * record via printk and then see if we want to try and hold on to the record
571 * and queue it, if we have room. If we want to hold on to the record, but we
572 * don't have room, record a record lost message.
573 */
574static void kauditd_hold_skb(struct sk_buff *skb)
575{
576 /* at this point it is uncertain if we will ever send this to auditd so
577 * try to send the message via printk before we go any further */
578 kauditd_printk_skb(skb);
579
580 /* can we just silently drop the message? */
581 if (!audit_default) {
582 kfree_skb(skb);
583 return;
584 }
585
586 /* if we have room, queue the message */
587 if (!audit_backlog_limit ||
588 skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
589 skb_queue_tail(&audit_hold_queue, skb);
590 return;
591 }
592
593 /* we have no other options - drop the message */
594 audit_log_lost("kauditd hold queue overflow");
595 kfree_skb(skb);
596}
597
598/**
599 * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
600 * @skb: audit record
601 *
602 * Description:
603 * Not as serious as kauditd_hold_skb() as we still have a connected auditd,
604 * but for some reason we are having problems sending it audit records so
605 * queue the given record and attempt to resend.
606 */
607static void kauditd_retry_skb(struct sk_buff *skb)
608{
609 /* NOTE: because records should only live in the retry queue for a
610 * short period of time, before either being sent or moved to the hold
611 * queue, we don't currently enforce a limit on this queue */
612 skb_queue_tail(&audit_retry_queue, skb);
613}
614
615/**
616 * auditd_reset - Disconnect the auditd connection
617 * @ac: auditd connection state
618 *
619 * Description:
620 * Break the auditd/kauditd connection and move all the queued records into the
621 * hold queue in case auditd reconnects. It is important to note that the @ac
622 * pointer should never be dereferenced inside this function as it may be NULL
623 * or invalid, you can only compare the memory address! If @ac is NULL then
624 * the connection will always be reset.
625 */
626static void auditd_reset(const struct auditd_connection *ac)
627{
628 unsigned long flags;
629 struct sk_buff *skb;
630 struct auditd_connection *ac_old;
631
632 /* if it isn't already broken, break the connection */
633 spin_lock_irqsave(&auditd_conn_lock, flags);
634 ac_old = rcu_dereference_protected(auditd_conn,
635 lockdep_is_held(&auditd_conn_lock));
636 if (ac && ac != ac_old) {
637 /* someone already registered a new auditd connection */
638 spin_unlock_irqrestore(&auditd_conn_lock, flags);
639 return;
640 }
641 rcu_assign_pointer(auditd_conn, NULL);
642 spin_unlock_irqrestore(&auditd_conn_lock, flags);
643
644 if (ac_old)
645 call_rcu(&ac_old->rcu, auditd_conn_free);
646
647 /* flush the retry queue to the hold queue, but don't touch the main
648 * queue since we need to process that normally for multicast */
649 while ((skb = skb_dequeue(&audit_retry_queue)))
650 kauditd_hold_skb(skb);
651}
652
653/**
654 * auditd_send_unicast_skb - Send a record via unicast to auditd
655 * @skb: audit record
656 *
657 * Description:
658 * Send a skb to the audit daemon, returns positive/zero values on success and
659 * negative values on failure; in all cases the skb will be consumed by this
660 * function. If the send results in -ECONNREFUSED the connection with auditd
661 * will be reset. This function may sleep so callers should not hold any locks
662 * where this would cause a problem.
663 */
664static int auditd_send_unicast_skb(struct sk_buff *skb)
665{
666 int rc;
667 u32 portid;
668 struct net *net;
669 struct sock *sk;
670 struct auditd_connection *ac;
671
672 /* NOTE: we can't call netlink_unicast while in the RCU section so
673 * take a reference to the network namespace and grab local
674 * copies of the namespace, the sock, and the portid; the
675 * namespace and sock aren't going to go away while we hold a
676 * reference and if the portid does become invalid after the RCU
677 * section netlink_unicast() should safely return an error */
678
679 rcu_read_lock();
680 ac = rcu_dereference(auditd_conn);
681 if (!ac) {
682 rcu_read_unlock();
683 kfree_skb(skb);
684 rc = -ECONNREFUSED;
685 goto err;
686 }
687 net = get_net(ac->net);
688 sk = audit_get_sk(net);
689 portid = ac->portid;
690 rcu_read_unlock();
691
692 rc = netlink_unicast(sk, skb, portid, 0);
693 put_net(net);
694 if (rc < 0)
695 goto err;
696
697 return rc;
698
699err:
700 if (ac && rc == -ECONNREFUSED)
701 auditd_reset(ac);
702 return rc;
703}
704
705/**
706 * kauditd_send_queue - Helper for kauditd_thread to flush skb queues
707 * @sk: the sending sock
708 * @portid: the netlink destination
709 * @queue: the skb queue to process
710 * @retry_limit: limit on number of netlink unicast failures
711 * @skb_hook: per-skb hook for additional processing
712 * @err_hook: hook called if the skb fails the netlink unicast send
713 *
714 * Description:
715 * Run through the given queue and attempt to send the audit records to auditd,
716 * returns zero on success, negative values on failure. It is up to the caller
717 * to ensure that the @sk is valid for the duration of this function.
718 *
719 */
720static int kauditd_send_queue(struct sock *sk, u32 portid,
721 struct sk_buff_head *queue,
722 unsigned int retry_limit,
723 void (*skb_hook)(struct sk_buff *skb),
724 void (*err_hook)(struct sk_buff *skb))
725{
726 int rc = 0;
727 struct sk_buff *skb;
728 static unsigned int failed = 0;
729
730 /* NOTE: kauditd_thread takes care of all our locking, we just use
731 * the netlink info passed to us (e.g. sk and portid) */
732
733 while ((skb = skb_dequeue(queue))) {
734 /* call the skb_hook for each skb we touch */
735 if (skb_hook)
736 (*skb_hook)(skb);
737
738 /* can we send to anyone via unicast? */
739 if (!sk) {
740 if (err_hook)
741 (*err_hook)(skb);
742 continue;
743 }
744
745 /* grab an extra skb reference in case of error */
746 skb_get(skb);
747 rc = netlink_unicast(sk, skb, portid, 0);
748 if (rc < 0) {
749 /* fatal failure for our queue flush attempt? */
750 if (++failed >= retry_limit ||
751 rc == -ECONNREFUSED || rc == -EPERM) {
752 /* yes - error processing for the queue */
753 sk = NULL;
754 if (err_hook)
755 (*err_hook)(skb);
756 if (!skb_hook)
757 goto out;
758 /* keep processing with the skb_hook */
759 continue;
760 } else
761 /* no - requeue to preserve ordering */
762 skb_queue_head(queue, skb);
763 } else {
764 /* it worked - drop the extra reference and continue */
765 consume_skb(skb);
766 failed = 0;
767 }
768 }
769
770out:
771 return (rc >= 0 ? 0 : rc);
772}
773
774/*
775 * kauditd_send_multicast_skb - Send a record to any multicast listeners
776 * @skb: audit record
777 *
778 * Description:
779 * Write a multicast message to anyone listening in the initial network
780 * namespace. This function doesn't consume an skb as might be expected since
781 * it has to copy it anyways.
782 */
783static void kauditd_send_multicast_skb(struct sk_buff *skb)
784{
785 struct sk_buff *copy;
786 struct sock *sock = audit_get_sk(&init_net);
787 struct nlmsghdr *nlh;
788
789 /* NOTE: we are not taking an additional reference for init_net since
790 * we don't have to worry about it going away */
791
792 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
793 return;
794
795 /*
796 * The seemingly wasteful skb_copy() rather than bumping the refcount
797 * using skb_get() is necessary because non-standard mods are made to
798 * the skb by the original kaudit unicast socket send routine. The
799 * existing auditd daemon assumes this breakage. Fixing this would
800 * require co-ordinating a change in the established protocol between
801 * the kaudit kernel subsystem and the auditd userspace code. There is
802 * no reason for new multicast clients to continue with this
803 * non-compliance.
804 */
805 copy = skb_copy(skb, GFP_KERNEL);
806 if (!copy)
807 return;
808 nlh = nlmsg_hdr(copy);
809 nlh->nlmsg_len = skb->len;
810
811 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
812}
813
814/**
815 * kauditd_thread - Worker thread to send audit records to userspace
816 * @dummy: unused
817 */
818static int kauditd_thread(void *dummy)
819{
820 int rc;
821 u32 portid = 0;
822 struct net *net = NULL;
823 struct sock *sk = NULL;
824 struct auditd_connection *ac;
825
826#define UNICAST_RETRIES 5
827
828 set_freezable();
829 while (!kthread_should_stop()) {
830 /* NOTE: see the lock comments in auditd_send_unicast_skb() */
831 rcu_read_lock();
832 ac = rcu_dereference(auditd_conn);
833 if (!ac) {
834 rcu_read_unlock();
835 goto main_queue;
836 }
837 net = get_net(ac->net);
838 sk = audit_get_sk(net);
839 portid = ac->portid;
840 rcu_read_unlock();
841
842 /* attempt to flush the hold queue */
843 rc = kauditd_send_queue(sk, portid,
844 &audit_hold_queue, UNICAST_RETRIES,
845 NULL, kauditd_rehold_skb);
846 if (ac && rc < 0) {
847 sk = NULL;
848 auditd_reset(ac);
849 goto main_queue;
850 }
851
852 /* attempt to flush the retry queue */
853 rc = kauditd_send_queue(sk, portid,
854 &audit_retry_queue, UNICAST_RETRIES,
855 NULL, kauditd_hold_skb);
856 if (ac && rc < 0) {
857 sk = NULL;
858 auditd_reset(ac);
859 goto main_queue;
860 }
861
862main_queue:
863 /* process the main queue - do the multicast send and attempt
864 * unicast, dump failed record sends to the retry queue; if
865 * sk == NULL due to previous failures we will just do the
866 * multicast send and move the record to the hold queue */
867 rc = kauditd_send_queue(sk, portid, &audit_queue, 1,
868 kauditd_send_multicast_skb,
869 (sk ?
870 kauditd_retry_skb : kauditd_hold_skb));
871 if (ac && rc < 0)
872 auditd_reset(ac);
873 sk = NULL;
874
875 /* drop our netns reference, no auditd sends past this line */
876 if (net) {
877 put_net(net);
878 net = NULL;
879 }
880
881 /* we have processed all the queues so wake everyone */
882 wake_up(&audit_backlog_wait);
883
884 /* NOTE: we want to wake up if there is anything on the queue,
885 * regardless of if an auditd is connected, as we need to
886 * do the multicast send and rotate records from the
887 * main queue to the retry/hold queues */
888 wait_event_freezable(kauditd_wait,
889 (skb_queue_len(&audit_queue) ? 1 : 0));
890 }
891
892 return 0;
893}
894
895int audit_send_list(void *_dest)
896{
897 struct audit_netlink_list *dest = _dest;
898 struct sk_buff *skb;
899 struct sock *sk = audit_get_sk(dest->net);
900
901 /* wait for parent to finish and send an ACK */
902 audit_ctl_lock();
903 audit_ctl_unlock();
904
905 while ((skb = __skb_dequeue(&dest->q)) != NULL)
906 netlink_unicast(sk, skb, dest->portid, 0);
907
908 put_net(dest->net);
909 kfree(dest);
910
911 return 0;
912}
913
914struct sk_buff *audit_make_reply(int seq, int type, int done,
915 int multi, const void *payload, int size)
916{
917 struct sk_buff *skb;
918 struct nlmsghdr *nlh;
919 void *data;
920 int flags = multi ? NLM_F_MULTI : 0;
921 int t = done ? NLMSG_DONE : type;
922
923 skb = nlmsg_new(size, GFP_KERNEL);
924 if (!skb)
925 return NULL;
926
927 nlh = nlmsg_put(skb, 0, seq, t, size, flags);
928 if (!nlh)
929 goto out_kfree_skb;
930 data = nlmsg_data(nlh);
931 memcpy(data, payload, size);
932 return skb;
933
934out_kfree_skb:
935 kfree_skb(skb);
936 return NULL;
937}
938
939static int audit_send_reply_thread(void *arg)
940{
941 struct audit_reply *reply = (struct audit_reply *)arg;
942 struct sock *sk = audit_get_sk(reply->net);
943
944 audit_ctl_lock();
945 audit_ctl_unlock();
946
947 /* Ignore failure. It'll only happen if the sender goes away,
948 because our timeout is set to infinite. */
949 netlink_unicast(sk, reply->skb, reply->portid, 0);
950 put_net(reply->net);
951 kfree(reply);
952 return 0;
953}
954
955/**
956 * audit_send_reply - send an audit reply message via netlink
957 * @request_skb: skb of request we are replying to (used to target the reply)
958 * @seq: sequence number
959 * @type: audit message type
960 * @done: done (last) flag
961 * @multi: multi-part message flag
962 * @payload: payload data
963 * @size: payload size
964 *
965 * Allocates an skb, builds the netlink message, and sends it to the port id.
966 * No failure notifications.
967 */
968static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
969 int multi, const void *payload, int size)
970{
971 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
972 struct sk_buff *skb;
973 struct task_struct *tsk;
974 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
975 GFP_KERNEL);
976
977 if (!reply)
978 return;
979
980 skb = audit_make_reply(seq, type, done, multi, payload, size);
981 if (!skb)
982 goto out;
983
984 reply->net = get_net(net);
985 reply->portid = NETLINK_CB(request_skb).portid;
986 reply->skb = skb;
987
988 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
989 if (!IS_ERR(tsk))
990 return;
991 kfree_skb(skb);
992out:
993 kfree(reply);
994}
995
996/*
997 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
998 * control messages.
999 */
1000static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
1001{
1002 int err = 0;
1003
1004 /* Only support initial user namespace for now. */
1005 /*
1006 * We return ECONNREFUSED because it tricks userspace into thinking
1007 * that audit was not configured into the kernel. Lots of users
1008 * configure their PAM stack (because that's what the distro does)
1009 * to reject login if unable to send messages to audit. If we return
1010 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
1011 * configured in and will let login proceed. If we return EPERM
1012 * userspace will reject all logins. This should be removed when we
1013 * support non init namespaces!!
1014 */
1015 if (current_user_ns() != &init_user_ns)
1016 return -ECONNREFUSED;
1017
1018 switch (msg_type) {
1019 case AUDIT_LIST:
1020 case AUDIT_ADD:
1021 case AUDIT_DEL:
1022 return -EOPNOTSUPP;
1023 case AUDIT_GET:
1024 case AUDIT_SET:
1025 case AUDIT_GET_FEATURE:
1026 case AUDIT_SET_FEATURE:
1027 case AUDIT_LIST_RULES:
1028 case AUDIT_ADD_RULE:
1029 case AUDIT_DEL_RULE:
1030 case AUDIT_SIGNAL_INFO:
1031 case AUDIT_TTY_GET:
1032 case AUDIT_TTY_SET:
1033 case AUDIT_TRIM:
1034 case AUDIT_MAKE_EQUIV:
1035 /* Only support auditd and auditctl in initial pid namespace
1036 * for now. */
1037 if (task_active_pid_ns(current) != &init_pid_ns)
1038 return -EPERM;
1039
1040 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
1041 err = -EPERM;
1042 break;
1043 case AUDIT_USER:
1044 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1045 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1046 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
1047 err = -EPERM;
1048 break;
1049 default: /* bad msg */
1050 err = -EINVAL;
1051 }
1052
1053 return err;
1054}
1055
1056static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
1057{
1058 uid_t uid = from_kuid(&init_user_ns, current_uid());
1059 pid_t pid = task_tgid_nr(current);
1060
1061 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
1062 *ab = NULL;
1063 return;
1064 }
1065
1066 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
1067 if (unlikely(!*ab))
1068 return;
1069 audit_log_format(*ab, "pid=%d uid=%u ", pid, uid);
1070 audit_log_session_info(*ab);
1071 audit_log_task_context(*ab);
1072}
1073
1074int is_audit_feature_set(int i)
1075{
1076 return af.features & AUDIT_FEATURE_TO_MASK(i);
1077}
1078
1079
1080static int audit_get_feature(struct sk_buff *skb)
1081{
1082 u32 seq;
1083
1084 seq = nlmsg_hdr(skb)->nlmsg_seq;
1085
1086 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
1087
1088 return 0;
1089}
1090
1091static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
1092 u32 old_lock, u32 new_lock, int res)
1093{
1094 struct audit_buffer *ab;
1095
1096 if (audit_enabled == AUDIT_OFF)
1097 return;
1098
1099 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_FEATURE_CHANGE);
1100 if (!ab)
1101 return;
1102 audit_log_task_info(ab);
1103 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
1104 audit_feature_names[which], !!old_feature, !!new_feature,
1105 !!old_lock, !!new_lock, res);
1106 audit_log_end(ab);
1107}
1108
1109static int audit_set_feature(struct sk_buff *skb)
1110{
1111 struct audit_features *uaf;
1112 int i;
1113
1114 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
1115 uaf = nlmsg_data(nlmsg_hdr(skb));
1116
1117 /* if there is ever a version 2 we should handle that here */
1118
1119 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1120 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1121 u32 old_feature, new_feature, old_lock, new_lock;
1122
1123 /* if we are not changing this feature, move along */
1124 if (!(feature & uaf->mask))
1125 continue;
1126
1127 old_feature = af.features & feature;
1128 new_feature = uaf->features & feature;
1129 new_lock = (uaf->lock | af.lock) & feature;
1130 old_lock = af.lock & feature;
1131
1132 /* are we changing a locked feature? */
1133 if (old_lock && (new_feature != old_feature)) {
1134 audit_log_feature_change(i, old_feature, new_feature,
1135 old_lock, new_lock, 0);
1136 return -EPERM;
1137 }
1138 }
1139 /* nothing invalid, do the changes */
1140 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1141 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1142 u32 old_feature, new_feature, old_lock, new_lock;
1143
1144 /* if we are not changing this feature, move along */
1145 if (!(feature & uaf->mask))
1146 continue;
1147
1148 old_feature = af.features & feature;
1149 new_feature = uaf->features & feature;
1150 old_lock = af.lock & feature;
1151 new_lock = (uaf->lock | af.lock) & feature;
1152
1153 if (new_feature != old_feature)
1154 audit_log_feature_change(i, old_feature, new_feature,
1155 old_lock, new_lock, 1);
1156
1157 if (new_feature)
1158 af.features |= feature;
1159 else
1160 af.features &= ~feature;
1161 af.lock |= new_lock;
1162 }
1163
1164 return 0;
1165}
1166
1167static int audit_replace(struct pid *pid)
1168{
1169 pid_t pvnr;
1170 struct sk_buff *skb;
1171
1172 pvnr = pid_vnr(pid);
1173 skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr));
1174 if (!skb)
1175 return -ENOMEM;
1176 return auditd_send_unicast_skb(skb);
1177}
1178
1179static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1180{
1181 u32 seq;
1182 void *data;
1183 int err;
1184 struct audit_buffer *ab;
1185 u16 msg_type = nlh->nlmsg_type;
1186 struct audit_sig_info *sig_data;
1187 char *ctx = NULL;
1188 u32 len;
1189
1190 err = audit_netlink_ok(skb, msg_type);
1191 if (err)
1192 return err;
1193
1194 seq = nlh->nlmsg_seq;
1195 data = nlmsg_data(nlh);
1196
1197 switch (msg_type) {
1198 case AUDIT_GET: {
1199 struct audit_status s;
1200 memset(&s, 0, sizeof(s));
1201 s.enabled = audit_enabled;
1202 s.failure = audit_failure;
1203 /* NOTE: use pid_vnr() so the PID is relative to the current
1204 * namespace */
1205 s.pid = auditd_pid_vnr();
1206 s.rate_limit = audit_rate_limit;
1207 s.backlog_limit = audit_backlog_limit;
1208 s.lost = atomic_read(&audit_lost);
1209 s.backlog = skb_queue_len(&audit_queue);
1210 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
1211 s.backlog_wait_time = audit_backlog_wait_time;
1212 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
1213 break;
1214 }
1215 case AUDIT_SET: {
1216 struct audit_status s;
1217 memset(&s, 0, sizeof(s));
1218 /* guard against past and future API changes */
1219 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
1220 if (s.mask & AUDIT_STATUS_ENABLED) {
1221 err = audit_set_enabled(s.enabled);
1222 if (err < 0)
1223 return err;
1224 }
1225 if (s.mask & AUDIT_STATUS_FAILURE) {
1226 err = audit_set_failure(s.failure);
1227 if (err < 0)
1228 return err;
1229 }
1230 if (s.mask & AUDIT_STATUS_PID) {
1231 /* NOTE: we are using the vnr PID functions below
1232 * because the s.pid value is relative to the
1233 * namespace of the caller; at present this
1234 * doesn't matter much since you can really only
1235 * run auditd from the initial pid namespace, but
1236 * something to keep in mind if this changes */
1237 pid_t new_pid = s.pid;
1238 pid_t auditd_pid;
1239 struct pid *req_pid = task_tgid(current);
1240
1241 /* Sanity check - PID values must match. Setting
1242 * pid to 0 is how auditd ends auditing. */
1243 if (new_pid && (new_pid != pid_vnr(req_pid)))
1244 return -EINVAL;
1245
1246 /* test the auditd connection */
1247 audit_replace(req_pid);
1248
1249 auditd_pid = auditd_pid_vnr();
1250 if (auditd_pid) {
1251 /* replacing a healthy auditd is not allowed */
1252 if (new_pid) {
1253 audit_log_config_change("audit_pid",
1254 new_pid, auditd_pid, 0);
1255 return -EEXIST;
1256 }
1257 /* only current auditd can unregister itself */
1258 if (pid_vnr(req_pid) != auditd_pid) {
1259 audit_log_config_change("audit_pid",
1260 new_pid, auditd_pid, 0);
1261 return -EACCES;
1262 }
1263 }
1264
1265 if (new_pid) {
1266 /* register a new auditd connection */
1267 err = auditd_set(req_pid,
1268 NETLINK_CB(skb).portid,
1269 sock_net(NETLINK_CB(skb).sk));
1270 if (audit_enabled != AUDIT_OFF)
1271 audit_log_config_change("audit_pid",
1272 new_pid,
1273 auditd_pid,
1274 err ? 0 : 1);
1275 if (err)
1276 return err;
1277
1278 /* try to process any backlog */
1279 wake_up_interruptible(&kauditd_wait);
1280 } else {
1281 if (audit_enabled != AUDIT_OFF)
1282 audit_log_config_change("audit_pid",
1283 new_pid,
1284 auditd_pid, 1);
1285
1286 /* unregister the auditd connection */
1287 auditd_reset(NULL);
1288 }
1289 }
1290 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
1291 err = audit_set_rate_limit(s.rate_limit);
1292 if (err < 0)
1293 return err;
1294 }
1295 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
1296 err = audit_set_backlog_limit(s.backlog_limit);
1297 if (err < 0)
1298 return err;
1299 }
1300 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
1301 if (sizeof(s) > (size_t)nlh->nlmsg_len)
1302 return -EINVAL;
1303 if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
1304 return -EINVAL;
1305 err = audit_set_backlog_wait_time(s.backlog_wait_time);
1306 if (err < 0)
1307 return err;
1308 }
1309 if (s.mask == AUDIT_STATUS_LOST) {
1310 u32 lost = atomic_xchg(&audit_lost, 0);
1311
1312 audit_log_config_change("lost", 0, lost, 1);
1313 return lost;
1314 }
1315 break;
1316 }
1317 case AUDIT_GET_FEATURE:
1318 err = audit_get_feature(skb);
1319 if (err)
1320 return err;
1321 break;
1322 case AUDIT_SET_FEATURE:
1323 err = audit_set_feature(skb);
1324 if (err)
1325 return err;
1326 break;
1327 case AUDIT_USER:
1328 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1329 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1330 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
1331 return 0;
1332
1333 err = audit_filter(msg_type, AUDIT_FILTER_USER);
1334 if (err == 1) { /* match or error */
1335 err = 0;
1336 if (msg_type == AUDIT_USER_TTY) {
1337 err = tty_audit_push();
1338 if (err)
1339 break;
1340 }
1341 audit_log_common_recv_msg(&ab, msg_type);
1342 if (msg_type != AUDIT_USER_TTY)
1343 audit_log_format(ab, " msg='%.*s'",
1344 AUDIT_MESSAGE_TEXT_MAX,
1345 (char *)data);
1346 else {
1347 int size;
1348
1349 audit_log_format(ab, " data=");
1350 size = nlmsg_len(nlh);
1351 if (size > 0 &&
1352 ((unsigned char *)data)[size - 1] == '\0')
1353 size--;
1354 audit_log_n_untrustedstring(ab, data, size);
1355 }
1356 audit_log_end(ab);
1357 }
1358 break;
1359 case AUDIT_ADD_RULE:
1360 case AUDIT_DEL_RULE:
1361 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
1362 return -EINVAL;
1363 if (audit_enabled == AUDIT_LOCKED) {
1364 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1365 audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
1366 audit_log_end(ab);
1367 return -EPERM;
1368 }
1369 err = audit_rule_change(msg_type, seq, data, nlmsg_len(nlh));
1370 break;
1371 case AUDIT_LIST_RULES:
1372 err = audit_list_rules_send(skb, seq);
1373 break;
1374 case AUDIT_TRIM:
1375 audit_trim_trees();
1376 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1377 audit_log_format(ab, " op=trim res=1");
1378 audit_log_end(ab);
1379 break;
1380 case AUDIT_MAKE_EQUIV: {
1381 void *bufp = data;
1382 u32 sizes[2];
1383 size_t msglen = nlmsg_len(nlh);
1384 char *old, *new;
1385
1386 err = -EINVAL;
1387 if (msglen < 2 * sizeof(u32))
1388 break;
1389 memcpy(sizes, bufp, 2 * sizeof(u32));
1390 bufp += 2 * sizeof(u32);
1391 msglen -= 2 * sizeof(u32);
1392 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
1393 if (IS_ERR(old)) {
1394 err = PTR_ERR(old);
1395 break;
1396 }
1397 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
1398 if (IS_ERR(new)) {
1399 err = PTR_ERR(new);
1400 kfree(old);
1401 break;
1402 }
1403 /* OK, here comes... */
1404 err = audit_tag_tree(old, new);
1405
1406 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1407
1408 audit_log_format(ab, " op=make_equiv old=");
1409 audit_log_untrustedstring(ab, old);
1410 audit_log_format(ab, " new=");
1411 audit_log_untrustedstring(ab, new);
1412 audit_log_format(ab, " res=%d", !err);
1413 audit_log_end(ab);
1414 kfree(old);
1415 kfree(new);
1416 break;
1417 }
1418 case AUDIT_SIGNAL_INFO:
1419 len = 0;
1420 if (audit_sig_sid) {
1421 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1422 if (err)
1423 return err;
1424 }
1425 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1426 if (!sig_data) {
1427 if (audit_sig_sid)
1428 security_release_secctx(ctx, len);
1429 return -ENOMEM;
1430 }
1431 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
1432 sig_data->pid = audit_sig_pid;
1433 if (audit_sig_sid) {
1434 memcpy(sig_data->ctx, ctx, len);
1435 security_release_secctx(ctx, len);
1436 }
1437 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1438 sig_data, sizeof(*sig_data) + len);
1439 kfree(sig_data);
1440 break;
1441 case AUDIT_TTY_GET: {
1442 struct audit_tty_status s;
1443 unsigned int t;
1444
1445 t = READ_ONCE(current->signal->audit_tty);
1446 s.enabled = t & AUDIT_TTY_ENABLE;
1447 s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1448
1449 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
1450 break;
1451 }
1452 case AUDIT_TTY_SET: {
1453 struct audit_tty_status s, old;
1454 struct audit_buffer *ab;
1455 unsigned int t;
1456
1457 memset(&s, 0, sizeof(s));
1458 /* guard against past and future API changes */
1459 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
1460 /* check if new data is valid */
1461 if ((s.enabled != 0 && s.enabled != 1) ||
1462 (s.log_passwd != 0 && s.log_passwd != 1))
1463 err = -EINVAL;
1464
1465 if (err)
1466 t = READ_ONCE(current->signal->audit_tty);
1467 else {
1468 t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
1469 t = xchg(&current->signal->audit_tty, t);
1470 }
1471 old.enabled = t & AUDIT_TTY_ENABLE;
1472 old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1473
1474 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1475 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1476 " old-log_passwd=%d new-log_passwd=%d res=%d",
1477 old.enabled, s.enabled, old.log_passwd,
1478 s.log_passwd, !err);
1479 audit_log_end(ab);
1480 break;
1481 }
1482 default:
1483 err = -EINVAL;
1484 break;
1485 }
1486
1487 return err < 0 ? err : 0;
1488}
1489
1490/**
1491 * audit_receive - receive messages from a netlink control socket
1492 * @skb: the message buffer
1493 *
1494 * Parse the provided skb and deal with any messages that may be present,
1495 * malformed skbs are discarded.
1496 */
1497static void audit_receive(struct sk_buff *skb)
1498{
1499 struct nlmsghdr *nlh;
1500 /*
1501 * len MUST be signed for nlmsg_next to be able to dec it below 0
1502 * if the nlmsg_len was not aligned
1503 */
1504 int len;
1505 int err;
1506
1507 nlh = nlmsg_hdr(skb);
1508 len = skb->len;
1509
1510 audit_ctl_lock();
1511 while (nlmsg_ok(nlh, len)) {
1512 err = audit_receive_msg(skb, nlh);
1513 /* if err or if this message says it wants a response */
1514 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1515 netlink_ack(skb, nlh, err, NULL);
1516
1517 nlh = nlmsg_next(nlh, &len);
1518 }
1519 audit_ctl_unlock();
1520}
1521
1522/* Run custom bind function on netlink socket group connect or bind requests. */
1523static int audit_bind(struct net *net, int group)
1524{
1525 if (!capable(CAP_AUDIT_READ))
1526 return -EPERM;
1527
1528 return 0;
1529}
1530
1531static int __net_init audit_net_init(struct net *net)
1532{
1533 struct netlink_kernel_cfg cfg = {
1534 .input = audit_receive,
1535 .bind = audit_bind,
1536 .flags = NL_CFG_F_NONROOT_RECV,
1537 .groups = AUDIT_NLGRP_MAX,
1538 };
1539
1540 struct audit_net *aunet = net_generic(net, audit_net_id);
1541
1542 aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1543 if (aunet->sk == NULL) {
1544 audit_panic("cannot initialize netlink socket in namespace");
1545 return -ENOMEM;
1546 }
1547 aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
1548
1549 return 0;
1550}
1551
1552static void __net_exit audit_net_exit(struct net *net)
1553{
1554 struct audit_net *aunet = net_generic(net, audit_net_id);
1555
1556 /* NOTE: you would think that we would want to check the auditd
1557 * connection and potentially reset it here if it lives in this
1558 * namespace, but since the auditd connection tracking struct holds a
1559 * reference to this namespace (see auditd_set()) we are only ever
1560 * going to get here after that connection has been released */
1561
1562 netlink_kernel_release(aunet->sk);
1563}
1564
1565static struct pernet_operations audit_net_ops __net_initdata = {
1566 .init = audit_net_init,
1567 .exit = audit_net_exit,
1568 .id = &audit_net_id,
1569 .size = sizeof(struct audit_net),
1570};
1571
1572/* Initialize audit support at boot time. */
1573static int __init audit_init(void)
1574{
1575 int i;
1576
1577 if (audit_initialized == AUDIT_DISABLED)
1578 return 0;
1579
1580 audit_buffer_cache = kmem_cache_create("audit_buffer",
1581 sizeof(struct audit_buffer),
1582 0, SLAB_PANIC, NULL);
1583
1584 skb_queue_head_init(&audit_queue);
1585 skb_queue_head_init(&audit_retry_queue);
1586 skb_queue_head_init(&audit_hold_queue);
1587
1588 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1589 INIT_LIST_HEAD(&audit_inode_hash[i]);
1590
1591 mutex_init(&audit_cmd_mutex.lock);
1592 audit_cmd_mutex.owner = NULL;
1593
1594 pr_info("initializing netlink subsys (%s)\n",
1595 audit_default ? "enabled" : "disabled");
1596 register_pernet_subsys(&audit_net_ops);
1597
1598 audit_initialized = AUDIT_INITIALIZED;
1599
1600 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
1601 if (IS_ERR(kauditd_task)) {
1602 int err = PTR_ERR(kauditd_task);
1603 panic("audit: failed to start the kauditd thread (%d)\n", err);
1604 }
1605
1606 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL,
1607 "state=initialized audit_enabled=%u res=1",
1608 audit_enabled);
1609
1610 return 0;
1611}
1612postcore_initcall(audit_init);
1613
1614/*
1615 * Process kernel command-line parameter at boot time.
1616 * audit={0|off} or audit={1|on}.
1617 */
1618static int __init audit_enable(char *str)
1619{
1620 if (!strcasecmp(str, "off") || !strcmp(str, "0"))
1621 audit_default = AUDIT_OFF;
1622 else if (!strcasecmp(str, "on") || !strcmp(str, "1"))
1623 audit_default = AUDIT_ON;
1624 else {
1625 pr_err("audit: invalid 'audit' parameter value (%s)\n", str);
1626 audit_default = AUDIT_ON;
1627 }
1628
1629 if (audit_default == AUDIT_OFF)
1630 audit_initialized = AUDIT_DISABLED;
1631 if (audit_set_enabled(audit_default))
1632 pr_err("audit: error setting audit state (%d)\n",
1633 audit_default);
1634
1635 pr_info("%s\n", audit_default ?
1636 "enabled (after initialization)" : "disabled (until reboot)");
1637
1638 return 1;
1639}
1640__setup("audit=", audit_enable);
1641
1642/* Process kernel command-line parameter at boot time.
1643 * audit_backlog_limit=<n> */
1644static int __init audit_backlog_limit_set(char *str)
1645{
1646 u32 audit_backlog_limit_arg;
1647
1648 pr_info("audit_backlog_limit: ");
1649 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1650 pr_cont("using default of %u, unable to parse %s\n",
1651 audit_backlog_limit, str);
1652 return 1;
1653 }
1654
1655 audit_backlog_limit = audit_backlog_limit_arg;
1656 pr_cont("%d\n", audit_backlog_limit);
1657
1658 return 1;
1659}
1660__setup("audit_backlog_limit=", audit_backlog_limit_set);
1661
1662static void audit_buffer_free(struct audit_buffer *ab)
1663{
1664 if (!ab)
1665 return;
1666
1667 kfree_skb(ab->skb);
1668 kmem_cache_free(audit_buffer_cache, ab);
1669}
1670
1671static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
1672 gfp_t gfp_mask, int type)
1673{
1674 struct audit_buffer *ab;
1675
1676 ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask);
1677 if (!ab)
1678 return NULL;
1679
1680 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1681 if (!ab->skb)
1682 goto err;
1683 if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
1684 goto err;
1685
1686 ab->ctx = ctx;
1687 ab->gfp_mask = gfp_mask;
1688
1689 return ab;
1690
1691err:
1692 audit_buffer_free(ab);
1693 return NULL;
1694}
1695
1696/**
1697 * audit_serial - compute a serial number for the audit record
1698 *
1699 * Compute a serial number for the audit record. Audit records are
1700 * written to user-space as soon as they are generated, so a complete
1701 * audit record may be written in several pieces. The timestamp of the
1702 * record and this serial number are used by the user-space tools to
1703 * determine which pieces belong to the same audit record. The
1704 * (timestamp,serial) tuple is unique for each syscall and is live from
1705 * syscall entry to syscall exit.
1706 *
1707 * NOTE: Another possibility is to store the formatted records off the
1708 * audit context (for those records that have a context), and emit them
1709 * all at syscall exit. However, this could delay the reporting of
1710 * significant errors until syscall exit (or never, if the system
1711 * halts).
1712 */
1713unsigned int audit_serial(void)
1714{
1715 static atomic_t serial = ATOMIC_INIT(0);
1716
1717 return atomic_add_return(1, &serial);
1718}
1719
1720static inline void audit_get_stamp(struct audit_context *ctx,
1721 struct timespec64 *t, unsigned int *serial)
1722{
1723 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1724 ktime_get_coarse_real_ts64(t);
1725 *serial = audit_serial();
1726 }
1727}
1728
1729/**
1730 * audit_log_start - obtain an audit buffer
1731 * @ctx: audit_context (may be NULL)
1732 * @gfp_mask: type of allocation
1733 * @type: audit message type
1734 *
1735 * Returns audit_buffer pointer on success or NULL on error.
1736 *
1737 * Obtain an audit buffer. This routine does locking to obtain the
1738 * audit buffer, but then no locking is required for calls to
1739 * audit_log_*format. If the task (ctx) is a task that is currently in a
1740 * syscall, then the syscall is marked as auditable and an audit record
1741 * will be written at syscall exit. If there is no associated task, then
1742 * task context (ctx) should be NULL.
1743 */
1744struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1745 int type)
1746{
1747 struct audit_buffer *ab;
1748 struct timespec64 t;
1749 unsigned int uninitialized_var(serial);
1750
1751 if (audit_initialized != AUDIT_INITIALIZED)
1752 return NULL;
1753
1754 if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCLUDE)))
1755 return NULL;
1756
1757 /* NOTE: don't ever fail/sleep on these two conditions:
1758 * 1. auditd generated record - since we need auditd to drain the
1759 * queue; also, when we are checking for auditd, compare PIDs using
1760 * task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
1761 * using a PID anchored in the caller's namespace
1762 * 2. generator holding the audit_cmd_mutex - we don't want to block
1763 * while holding the mutex */
1764 if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
1765 long stime = audit_backlog_wait_time;
1766
1767 while (audit_backlog_limit &&
1768 (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
1769 /* wake kauditd to try and flush the queue */
1770 wake_up_interruptible(&kauditd_wait);
1771
1772 /* sleep if we are allowed and we haven't exhausted our
1773 * backlog wait limit */
1774 if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
1775 DECLARE_WAITQUEUE(wait, current);
1776
1777 add_wait_queue_exclusive(&audit_backlog_wait,
1778 &wait);
1779 set_current_state(TASK_UNINTERRUPTIBLE);
1780 stime = schedule_timeout(stime);
1781 remove_wait_queue(&audit_backlog_wait, &wait);
1782 } else {
1783 if (audit_rate_check() && printk_ratelimit())
1784 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1785 skb_queue_len(&audit_queue),
1786 audit_backlog_limit);
1787 audit_log_lost("backlog limit exceeded");
1788 return NULL;
1789 }
1790 }
1791 }
1792
1793 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1794 if (!ab) {
1795 audit_log_lost("out of memory in audit_log_start");
1796 return NULL;
1797 }
1798
1799 audit_get_stamp(ab->ctx, &t, &serial);
1800 audit_log_format(ab, "audit(%llu.%03lu:%u): ",
1801 (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
1802
1803 return ab;
1804}
1805
1806/**
1807 * audit_expand - expand skb in the audit buffer
1808 * @ab: audit_buffer
1809 * @extra: space to add at tail of the skb
1810 *
1811 * Returns 0 (no space) on failed expansion, or available space if
1812 * successful.
1813 */
1814static inline int audit_expand(struct audit_buffer *ab, int extra)
1815{
1816 struct sk_buff *skb = ab->skb;
1817 int oldtail = skb_tailroom(skb);
1818 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1819 int newtail = skb_tailroom(skb);
1820
1821 if (ret < 0) {
1822 audit_log_lost("out of memory in audit_expand");
1823 return 0;
1824 }
1825
1826 skb->truesize += newtail - oldtail;
1827 return newtail;
1828}
1829
1830/*
1831 * Format an audit message into the audit buffer. If there isn't enough
1832 * room in the audit buffer, more room will be allocated and vsnprint
1833 * will be called a second time. Currently, we assume that a printk
1834 * can't format message larger than 1024 bytes, so we don't either.
1835 */
1836static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1837 va_list args)
1838{
1839 int len, avail;
1840 struct sk_buff *skb;
1841 va_list args2;
1842
1843 if (!ab)
1844 return;
1845
1846 BUG_ON(!ab->skb);
1847 skb = ab->skb;
1848 avail = skb_tailroom(skb);
1849 if (avail == 0) {
1850 avail = audit_expand(ab, AUDIT_BUFSIZ);
1851 if (!avail)
1852 goto out;
1853 }
1854 va_copy(args2, args);
1855 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1856 if (len >= avail) {
1857 /* The printk buffer is 1024 bytes long, so if we get
1858 * here and AUDIT_BUFSIZ is at least 1024, then we can
1859 * log everything that printk could have logged. */
1860 avail = audit_expand(ab,
1861 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1862 if (!avail)
1863 goto out_va_end;
1864 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1865 }
1866 if (len > 0)
1867 skb_put(skb, len);
1868out_va_end:
1869 va_end(args2);
1870out:
1871 return;
1872}
1873
1874/**
1875 * audit_log_format - format a message into the audit buffer.
1876 * @ab: audit_buffer
1877 * @fmt: format string
1878 * @...: optional parameters matching @fmt string
1879 *
1880 * All the work is done in audit_log_vformat.
1881 */
1882void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1883{
1884 va_list args;
1885
1886 if (!ab)
1887 return;
1888 va_start(args, fmt);
1889 audit_log_vformat(ab, fmt, args);
1890 va_end(args);
1891}
1892
1893/**
1894 * audit_log_n_hex - convert a buffer to hex and append it to the audit skb
1895 * @ab: the audit_buffer
1896 * @buf: buffer to convert to hex
1897 * @len: length of @buf to be converted
1898 *
1899 * No return value; failure to expand is silently ignored.
1900 *
1901 * This function will take the passed buf and convert it into a string of
1902 * ascii hex digits. The new string is placed onto the skb.
1903 */
1904void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1905 size_t len)
1906{
1907 int i, avail, new_len;
1908 unsigned char *ptr;
1909 struct sk_buff *skb;
1910
1911 if (!ab)
1912 return;
1913
1914 BUG_ON(!ab->skb);
1915 skb = ab->skb;
1916 avail = skb_tailroom(skb);
1917 new_len = len<<1;
1918 if (new_len >= avail) {
1919 /* Round the buffer request up to the next multiple */
1920 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1921 avail = audit_expand(ab, new_len);
1922 if (!avail)
1923 return;
1924 }
1925
1926 ptr = skb_tail_pointer(skb);
1927 for (i = 0; i < len; i++)
1928 ptr = hex_byte_pack_upper(ptr, buf[i]);
1929 *ptr = 0;
1930 skb_put(skb, len << 1); /* new string is twice the old string */
1931}
1932
1933/*
1934 * Format a string of no more than slen characters into the audit buffer,
1935 * enclosed in quote marks.
1936 */
1937void audit_log_n_string(struct audit_buffer *ab, const char *string,
1938 size_t slen)
1939{
1940 int avail, new_len;
1941 unsigned char *ptr;
1942 struct sk_buff *skb;
1943
1944 if (!ab)
1945 return;
1946
1947 BUG_ON(!ab->skb);
1948 skb = ab->skb;
1949 avail = skb_tailroom(skb);
1950 new_len = slen + 3; /* enclosing quotes + null terminator */
1951 if (new_len > avail) {
1952 avail = audit_expand(ab, new_len);
1953 if (!avail)
1954 return;
1955 }
1956 ptr = skb_tail_pointer(skb);
1957 *ptr++ = '"';
1958 memcpy(ptr, string, slen);
1959 ptr += slen;
1960 *ptr++ = '"';
1961 *ptr = 0;
1962 skb_put(skb, slen + 2); /* don't include null terminator */
1963}
1964
1965/**
1966 * audit_string_contains_control - does a string need to be logged in hex
1967 * @string: string to be checked
1968 * @len: max length of the string to check
1969 */
1970bool audit_string_contains_control(const char *string, size_t len)
1971{
1972 const unsigned char *p;
1973 for (p = string; p < (const unsigned char *)string + len; p++) {
1974 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1975 return true;
1976 }
1977 return false;
1978}
1979
1980/**
1981 * audit_log_n_untrustedstring - log a string that may contain random characters
1982 * @ab: audit_buffer
1983 * @len: length of string (not including trailing null)
1984 * @string: string to be logged
1985 *
1986 * This code will escape a string that is passed to it if the string
1987 * contains a control character, unprintable character, double quote mark,
1988 * or a space. Unescaped strings will start and end with a double quote mark.
1989 * Strings that are escaped are printed in hex (2 digits per char).
1990 *
1991 * The caller specifies the number of characters in the string to log, which may
1992 * or may not be the entire string.
1993 */
1994void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1995 size_t len)
1996{
1997 if (audit_string_contains_control(string, len))
1998 audit_log_n_hex(ab, string, len);
1999 else
2000 audit_log_n_string(ab, string, len);
2001}
2002
2003/**
2004 * audit_log_untrustedstring - log a string that may contain random characters
2005 * @ab: audit_buffer
2006 * @string: string to be logged
2007 *
2008 * Same as audit_log_n_untrustedstring(), except that strlen is used to
2009 * determine string length.
2010 */
2011void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
2012{
2013 audit_log_n_untrustedstring(ab, string, strlen(string));
2014}
2015
2016/* This is a helper-function to print the escaped d_path */
2017void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
2018 const struct path *path)
2019{
2020 char *p, *pathname;
2021
2022 if (prefix)
2023 audit_log_format(ab, "%s", prefix);
2024
2025 /* We will allow 11 spaces for ' (deleted)' to be appended */
2026 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
2027 if (!pathname) {
2028 audit_log_string(ab, "<no_memory>");
2029 return;
2030 }
2031 p = d_path(path, pathname, PATH_MAX+11);
2032 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
2033 /* FIXME: can we save some information here? */
2034 audit_log_string(ab, "<too_long>");
2035 } else
2036 audit_log_untrustedstring(ab, p);
2037 kfree(pathname);
2038}
2039
2040void audit_log_session_info(struct audit_buffer *ab)
2041{
2042 unsigned int sessionid = audit_get_sessionid(current);
2043 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
2044
2045 audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
2046}
2047
2048void audit_log_key(struct audit_buffer *ab, char *key)
2049{
2050 audit_log_format(ab, " key=");
2051 if (key)
2052 audit_log_untrustedstring(ab, key);
2053 else
2054 audit_log_format(ab, "(null)");
2055}
2056
2057void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
2058{
2059 int i;
2060
2061 if (cap_isclear(*cap)) {
2062 audit_log_format(ab, " %s=0", prefix);
2063 return;
2064 }
2065 audit_log_format(ab, " %s=", prefix);
2066 CAP_FOR_EACH_U32(i)
2067 audit_log_format(ab, "%08x", cap->cap[CAP_LAST_U32 - i]);
2068}
2069
2070static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
2071{
2072 audit_log_cap(ab, "cap_fp", &name->fcap.permitted);
2073 audit_log_cap(ab, "cap_fi", &name->fcap.inheritable);
2074 audit_log_format(ab, " cap_fe=%d cap_fver=%x",
2075 name->fcap.fE, name->fcap_ver);
2076}
2077
2078static inline int audit_copy_fcaps(struct audit_names *name,
2079 const struct dentry *dentry)
2080{
2081 struct cpu_vfs_cap_data caps;
2082 int rc;
2083
2084 if (!dentry)
2085 return 0;
2086
2087 rc = get_vfs_caps_from_disk(dentry, &caps);
2088 if (rc)
2089 return rc;
2090
2091 name->fcap.permitted = caps.permitted;
2092 name->fcap.inheritable = caps.inheritable;
2093 name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2094 name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
2095 VFS_CAP_REVISION_SHIFT;
2096
2097 return 0;
2098}
2099
2100/* Copy inode data into an audit_names. */
2101void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
2102 struct inode *inode)
2103{
2104 name->ino = inode->i_ino;
2105 name->dev = inode->i_sb->s_dev;
2106 name->mode = inode->i_mode;
2107 name->uid = inode->i_uid;
2108 name->gid = inode->i_gid;
2109 name->rdev = inode->i_rdev;
2110 security_inode_getsecid(inode, &name->osid);
2111 audit_copy_fcaps(name, dentry);
2112}
2113
2114/**
2115 * audit_log_name - produce AUDIT_PATH record from struct audit_names
2116 * @context: audit_context for the task
2117 * @n: audit_names structure with reportable details
2118 * @path: optional path to report instead of audit_names->name
2119 * @record_num: record number to report when handling a list of names
2120 * @call_panic: optional pointer to int that will be updated if secid fails
2121 */
2122void audit_log_name(struct audit_context *context, struct audit_names *n,
2123 const struct path *path, int record_num, int *call_panic)
2124{
2125 struct audit_buffer *ab;
2126 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
2127 if (!ab)
2128 return;
2129
2130 audit_log_format(ab, "item=%d", record_num);
2131
2132 if (path)
2133 audit_log_d_path(ab, " name=", path);
2134 else if (n->name) {
2135 switch (n->name_len) {
2136 case AUDIT_NAME_FULL:
2137 /* log the full path */
2138 audit_log_format(ab, " name=");
2139 audit_log_untrustedstring(ab, n->name->name);
2140 break;
2141 case 0:
2142 /* name was specified as a relative path and the
2143 * directory component is the cwd */
2144 audit_log_d_path(ab, " name=", &context->pwd);
2145 break;
2146 default:
2147 /* log the name's directory component */
2148 audit_log_format(ab, " name=");
2149 audit_log_n_untrustedstring(ab, n->name->name,
2150 n->name_len);
2151 }
2152 } else
2153 audit_log_format(ab, " name=(null)");
2154
2155 if (n->ino != AUDIT_INO_UNSET)
2156 audit_log_format(ab, " inode=%lu"
2157 " dev=%02x:%02x mode=%#ho"
2158 " ouid=%u ogid=%u rdev=%02x:%02x",
2159 n->ino,
2160 MAJOR(n->dev),
2161 MINOR(n->dev),
2162 n->mode,
2163 from_kuid(&init_user_ns, n->uid),
2164 from_kgid(&init_user_ns, n->gid),
2165 MAJOR(n->rdev),
2166 MINOR(n->rdev));
2167 if (n->osid != 0) {
2168 char *ctx = NULL;
2169 u32 len;
2170 if (security_secid_to_secctx(
2171 n->osid, &ctx, &len)) {
2172 audit_log_format(ab, " osid=%u", n->osid);
2173 if (call_panic)
2174 *call_panic = 2;
2175 } else {
2176 audit_log_format(ab, " obj=%s", ctx);
2177 security_release_secctx(ctx, len);
2178 }
2179 }
2180
2181 /* log the audit_names record type */
2182 switch(n->type) {
2183 case AUDIT_TYPE_NORMAL:
2184 audit_log_format(ab, " nametype=NORMAL");
2185 break;
2186 case AUDIT_TYPE_PARENT:
2187 audit_log_format(ab, " nametype=PARENT");
2188 break;
2189 case AUDIT_TYPE_CHILD_DELETE:
2190 audit_log_format(ab, " nametype=DELETE");
2191 break;
2192 case AUDIT_TYPE_CHILD_CREATE:
2193 audit_log_format(ab, " nametype=CREATE");
2194 break;
2195 default:
2196 audit_log_format(ab, " nametype=UNKNOWN");
2197 break;
2198 }
2199
2200 audit_log_fcaps(ab, n);
2201 audit_log_end(ab);
2202}
2203
2204int audit_log_task_context(struct audit_buffer *ab)
2205{
2206 char *ctx = NULL;
2207 unsigned len;
2208 int error;
2209 u32 sid;
2210
2211 security_task_getsecid(current, &sid);
2212 if (!sid)
2213 return 0;
2214
2215 error = security_secid_to_secctx(sid, &ctx, &len);
2216 if (error) {
2217 if (error != -EINVAL)
2218 goto error_path;
2219 return 0;
2220 }
2221
2222 audit_log_format(ab, " subj=%s", ctx);
2223 security_release_secctx(ctx, len);
2224 return 0;
2225
2226error_path:
2227 audit_panic("error in audit_log_task_context");
2228 return error;
2229}
2230EXPORT_SYMBOL(audit_log_task_context);
2231
2232void audit_log_d_path_exe(struct audit_buffer *ab,
2233 struct mm_struct *mm)
2234{
2235 struct file *exe_file;
2236
2237 if (!mm)
2238 goto out_null;
2239
2240 exe_file = get_mm_exe_file(mm);
2241 if (!exe_file)
2242 goto out_null;
2243
2244 audit_log_d_path(ab, " exe=", &exe_file->f_path);
2245 fput(exe_file);
2246 return;
2247out_null:
2248 audit_log_format(ab, " exe=(null)");
2249}
2250
2251struct tty_struct *audit_get_tty(void)
2252{
2253 struct tty_struct *tty = NULL;
2254 unsigned long flags;
2255
2256 spin_lock_irqsave(&current->sighand->siglock, flags);
2257 if (current->signal)
2258 tty = tty_kref_get(current->signal->tty);
2259 spin_unlock_irqrestore(&current->sighand->siglock, flags);
2260 return tty;
2261}
2262
2263void audit_put_tty(struct tty_struct *tty)
2264{
2265 tty_kref_put(tty);
2266}
2267
2268void audit_log_task_info(struct audit_buffer *ab)
2269{
2270 const struct cred *cred;
2271 char comm[sizeof(current->comm)];
2272 struct tty_struct *tty;
2273
2274 if (!ab)
2275 return;
2276
2277 cred = current_cred();
2278 tty = audit_get_tty();
2279 audit_log_format(ab,
2280 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
2281 " euid=%u suid=%u fsuid=%u"
2282 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
2283 task_ppid_nr(current),
2284 task_tgid_nr(current),
2285 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2286 from_kuid(&init_user_ns, cred->uid),
2287 from_kgid(&init_user_ns, cred->gid),
2288 from_kuid(&init_user_ns, cred->euid),
2289 from_kuid(&init_user_ns, cred->suid),
2290 from_kuid(&init_user_ns, cred->fsuid),
2291 from_kgid(&init_user_ns, cred->egid),
2292 from_kgid(&init_user_ns, cred->sgid),
2293 from_kgid(&init_user_ns, cred->fsgid),
2294 tty ? tty_name(tty) : "(none)",
2295 audit_get_sessionid(current));
2296 audit_put_tty(tty);
2297 audit_log_format(ab, " comm=");
2298 audit_log_untrustedstring(ab, get_task_comm(comm, current));
2299 audit_log_d_path_exe(ab, current->mm);
2300 audit_log_task_context(ab);
2301}
2302EXPORT_SYMBOL(audit_log_task_info);
2303
2304/**
2305 * audit_log_link_denied - report a link restriction denial
2306 * @operation: specific link operation
2307 */
2308void audit_log_link_denied(const char *operation)
2309{
2310 struct audit_buffer *ab;
2311
2312 if (!audit_enabled || audit_dummy_context())
2313 return;
2314
2315 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
2316 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_LINK);
2317 if (!ab)
2318 return;
2319 audit_log_format(ab, "op=%s", operation);
2320 audit_log_task_info(ab);
2321 audit_log_format(ab, " res=0");
2322 audit_log_end(ab);
2323}
2324
2325/**
2326 * audit_log_end - end one audit record
2327 * @ab: the audit_buffer
2328 *
2329 * We can not do a netlink send inside an irq context because it blocks (last
2330 * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
2331 * queue and a tasklet is scheduled to remove them from the queue outside the
2332 * irq context. May be called in any context.
2333 */
2334void audit_log_end(struct audit_buffer *ab)
2335{
2336 struct sk_buff *skb;
2337 struct nlmsghdr *nlh;
2338
2339 if (!ab)
2340 return;
2341
2342 if (audit_rate_check()) {
2343 skb = ab->skb;
2344 ab->skb = NULL;
2345
2346 /* setup the netlink header, see the comments in
2347 * kauditd_send_multicast_skb() for length quirks */
2348 nlh = nlmsg_hdr(skb);
2349 nlh->nlmsg_len = skb->len - NLMSG_HDRLEN;
2350
2351 /* queue the netlink packet and poke the kauditd thread */
2352 skb_queue_tail(&audit_queue, skb);
2353 wake_up_interruptible(&kauditd_wait);
2354 } else
2355 audit_log_lost("rate limit exceeded");
2356
2357 audit_buffer_free(ab);
2358}
2359
2360/**
2361 * audit_log - Log an audit record
2362 * @ctx: audit context
2363 * @gfp_mask: type of allocation
2364 * @type: audit message type
2365 * @fmt: format string to use
2366 * @...: variable parameters matching the format string
2367 *
2368 * This is a convenience function that calls audit_log_start,
2369 * audit_log_vformat, and audit_log_end. It may be called
2370 * in any context.
2371 */
2372void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
2373 const char *fmt, ...)
2374{
2375 struct audit_buffer *ab;
2376 va_list args;
2377
2378 ab = audit_log_start(ctx, gfp_mask, type);
2379 if (ab) {
2380 va_start(args, fmt);
2381 audit_log_vformat(ab, fmt, args);
2382 va_end(args);
2383 audit_log_end(ab);
2384 }
2385}
2386
2387EXPORT_SYMBOL(audit_log_start);
2388EXPORT_SYMBOL(audit_log_end);
2389EXPORT_SYMBOL(audit_log_format);
2390EXPORT_SYMBOL(audit_log);