revert "ARM: keystone: dts: add psci command definition"
[linux-2.6-block.git] / kernel / audit.c
CommitLineData
85c8721f 1/* audit.c -- Auditing support
1da177e4
LT
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 *
6a01b07f 5 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
1da177e4
LT
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 <faith@redhat.com>
23 *
d7a96f3a 24 * Goals: 1) Integrate fully with Security Modules.
1da177e4
LT
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 *
85c8721f 41 * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
1da177e4
LT
42 */
43
d957f7b7
JP
44#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
45
5b282552 46#include <linux/file.h>
1da177e4 47#include <linux/init.h>
7153e402 48#include <linux/types.h>
60063497 49#include <linux/atomic.h>
1da177e4 50#include <linux/mm.h>
9984de1a 51#include <linux/export.h>
5a0e3ad6 52#include <linux/slab.h>
b7d11258
DW
53#include <linux/err.h>
54#include <linux/kthread.h>
46e959ea 55#include <linux/kernel.h>
b24a30a7 56#include <linux/syscalls.h>
1da177e4
LT
57
58#include <linux/audit.h>
59
60#include <net/sock.h>
93315ed6 61#include <net/netlink.h>
1da177e4 62#include <linux/skbuff.h>
131ad62d
MDF
63#ifdef CONFIG_SECURITY
64#include <linux/security.h>
65#endif
7dfb7103 66#include <linux/freezer.h>
34e36d8e 67#include <linux/pid_namespace.h>
33faba7f 68#include <net/netns/generic.h>
3dc7e315
DG
69
70#include "audit.h"
1da177e4 71
a3f07114 72/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
1da177e4 73 * (Initialization happens after skb_init is called.) */
a3f07114
EP
74#define AUDIT_DISABLED -1
75#define AUDIT_UNINITIALIZED 0
76#define AUDIT_INITIALIZED 1
1da177e4
LT
77static int audit_initialized;
78
1a6b9f23
EP
79#define AUDIT_OFF 0
80#define AUDIT_ON 1
81#define AUDIT_LOCKED 2
3e1d0bb6
JP
82u32 audit_enabled;
83u32 audit_ever_enabled;
1da177e4 84
ae9d67af
JE
85EXPORT_SYMBOL_GPL(audit_enabled);
86
1da177e4 87/* Default state when kernel boots without any parameters. */
3e1d0bb6 88static u32 audit_default;
1da177e4
LT
89
90/* If auditing cannot proceed, audit_failure selects what happens. */
3e1d0bb6 91static u32 audit_failure = AUDIT_FAIL_PRINTK;
1da177e4 92
75c0371a
PE
93/*
94 * If audit records are to be written to the netlink socket, audit_pid
15e47304
EB
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.
75c0371a 97 */
c2f0c7c3 98int audit_pid;
f9441639 99static __u32 audit_nlk_portid;
1da177e4 100
b0dd25a8 101/* If audit_rate_limit is non-zero, limit the rate of sending audit records
1da177e4
LT
102 * to that number per second. This prevents DoS attacks, but results in
103 * audit records being dropped. */
3e1d0bb6 104static u32 audit_rate_limit;
1da177e4 105
40c0775e
RGB
106/* Number of outstanding audit_buffers allowed.
107 * When set to zero, this means unlimited. */
3e1d0bb6 108static u32 audit_backlog_limit = 64;
e789e561 109#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
a77ed4e5 110static u32 audit_backlog_wait_time_master = AUDIT_BACKLOG_WAIT_TIME;
3e1d0bb6 111static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
1da177e4 112
c2f0c7c3 113/* The identity of the user shutting down the audit system. */
cca080d9 114kuid_t audit_sig_uid = INVALID_UID;
c2f0c7c3 115pid_t audit_sig_pid = -1;
e1396065 116u32 audit_sig_sid = 0;
c2f0c7c3 117
1da177e4
LT
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
124*/
125static atomic_t audit_lost = ATOMIC_INIT(0);
126
127/* The netlink socket. */
128static struct sock *audit_sock;
c0a8d9b0 129static int audit_net_id;
1da177e4 130
f368c07d
AG
131/* Hash for inode-based rules */
132struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
133
b7d11258 134/* The audit_freelist is a list of pre-allocated audit buffers (if more
1da177e4
LT
135 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
136 * being placed on the freelist). */
1da177e4 137static DEFINE_SPINLOCK(audit_freelist_lock);
b0dd25a8 138static int audit_freelist_count;
1da177e4
LT
139static LIST_HEAD(audit_freelist);
140
b7d11258 141static struct sk_buff_head audit_skb_queue;
f3d357b0
EP
142/* queue of skbs to send to auditd when/if it comes back */
143static struct sk_buff_head audit_skb_hold_queue;
b7d11258
DW
144static struct task_struct *kauditd_task;
145static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
9ad9ad38 146static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
1da177e4 147
b0fed402
EP
148static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
149 .mask = -1,
150 .features = 0,
151 .lock = 0,};
152
21b85c31 153static char *audit_feature_names[2] = {
d040e5af 154 "only_unset_loginuid",
21b85c31 155 "loginuid_immutable",
b0fed402
EP
156};
157
158
f368c07d 159/* Serialize requests from userspace. */
916d7576 160DEFINE_MUTEX(audit_cmd_mutex);
1da177e4
LT
161
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
166
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)
170
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. */
176struct audit_buffer {
177 struct list_head list;
8fc6115c 178 struct sk_buff *skb; /* formatted skb ready to send */
1da177e4 179 struct audit_context *ctx; /* NULL or associated context */
9796fdd8 180 gfp_t gfp_mask;
1da177e4
LT
181};
182
f09ac9db 183struct audit_reply {
f9441639 184 __u32 portid;
638a0fd2 185 struct net *net;
f09ac9db
EP
186 struct sk_buff *skb;
187};
188
f9441639 189static void audit_set_portid(struct audit_buffer *ab, __u32 portid)
c0404993 190{
50397bd1
EP
191 if (ab) {
192 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
f9441639 193 nlh->nlmsg_pid = portid;
50397bd1 194 }
c0404993
SG
195}
196
8c8570fb 197void audit_panic(const char *message)
1da177e4 198{
d957f7b7 199 switch (audit_failure) {
1da177e4
LT
200 case AUDIT_FAIL_SILENT:
201 break;
202 case AUDIT_FAIL_PRINTK:
320f1b1e 203 if (printk_ratelimit())
d957f7b7 204 pr_err("%s\n", message);
1da177e4
LT
205 break;
206 case AUDIT_FAIL_PANIC:
b29ee87e
EP
207 /* test audit_pid since printk is always losey, why bother? */
208 if (audit_pid)
209 panic("audit: %s\n", message);
1da177e4
LT
210 break;
211 }
212}
213
214static inline int audit_rate_check(void)
215{
216 static unsigned long last_check = 0;
217 static int messages = 0;
218 static DEFINE_SPINLOCK(lock);
219 unsigned long flags;
220 unsigned long now;
221 unsigned long elapsed;
222 int retval = 0;
223
224 if (!audit_rate_limit) return 1;
225
226 spin_lock_irqsave(&lock, flags);
227 if (++messages < audit_rate_limit) {
228 retval = 1;
229 } else {
230 now = jiffies;
231 elapsed = now - last_check;
232 if (elapsed > HZ) {
233 last_check = now;
234 messages = 0;
235 retval = 1;
236 }
237 }
238 spin_unlock_irqrestore(&lock, flags);
239
240 return retval;
241}
242
b0dd25a8
RD
243/**
244 * audit_log_lost - conditionally log lost audit message event
245 * @message: the message stating reason for lost audit message
246 *
247 * Emit at least 1 message per second, even if audit_rate_check is
248 * throttling.
249 * Always increment the lost messages counter.
250*/
1da177e4
LT
251void audit_log_lost(const char *message)
252{
253 static unsigned long last_msg = 0;
254 static DEFINE_SPINLOCK(lock);
255 unsigned long flags;
256 unsigned long now;
257 int print;
258
259 atomic_inc(&audit_lost);
260
261 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
262
263 if (!print) {
264 spin_lock_irqsave(&lock, flags);
265 now = jiffies;
266 if (now - last_msg > HZ) {
267 print = 1;
268 last_msg = now;
269 }
270 spin_unlock_irqrestore(&lock, flags);
271 }
272
273 if (print) {
320f1b1e 274 if (printk_ratelimit())
3e1d0bb6 275 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
320f1b1e
EP
276 atomic_read(&audit_lost),
277 audit_rate_limit,
278 audit_backlog_limit);
1da177e4
LT
279 audit_panic(message);
280 }
1da177e4
LT
281}
282
3e1d0bb6 283static int audit_log_config_change(char *function_name, u32 new, u32 old,
2532386f 284 int allow_changes)
1da177e4 285{
1a6b9f23
EP
286 struct audit_buffer *ab;
287 int rc = 0;
ce29b682 288
1a6b9f23 289 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
0644ec0c
KC
290 if (unlikely(!ab))
291 return rc;
3e1d0bb6 292 audit_log_format(ab, "%s=%u old=%u", function_name, new, old);
4d3fb709 293 audit_log_session_info(ab);
b122c376
EP
294 rc = audit_log_task_context(ab);
295 if (rc)
296 allow_changes = 0; /* Something weird, deny request */
1a6b9f23
EP
297 audit_log_format(ab, " res=%d", allow_changes);
298 audit_log_end(ab);
6a01b07f 299 return rc;
1da177e4
LT
300}
301
3e1d0bb6 302static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
1da177e4 303{
3e1d0bb6
JP
304 int allow_changes, rc = 0;
305 u32 old = *to_change;
6a01b07f
SG
306
307 /* check if we are locked */
1a6b9f23
EP
308 if (audit_enabled == AUDIT_LOCKED)
309 allow_changes = 0;
6a01b07f 310 else
1a6b9f23 311 allow_changes = 1;
ce29b682 312
1a6b9f23 313 if (audit_enabled != AUDIT_OFF) {
dc9eb698 314 rc = audit_log_config_change(function_name, new, old, allow_changes);
1a6b9f23
EP
315 if (rc)
316 allow_changes = 0;
6a01b07f 317 }
6a01b07f
SG
318
319 /* If we are allowed, make the change */
1a6b9f23
EP
320 if (allow_changes == 1)
321 *to_change = new;
6a01b07f
SG
322 /* Not allowed, update reason */
323 else if (rc == 0)
324 rc = -EPERM;
325 return rc;
1da177e4
LT
326}
327
3e1d0bb6 328static int audit_set_rate_limit(u32 limit)
1da177e4 329{
dc9eb698 330 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
1a6b9f23 331}
ce29b682 332
3e1d0bb6 333static int audit_set_backlog_limit(u32 limit)
1a6b9f23 334{
dc9eb698 335 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
1a6b9f23 336}
6a01b07f 337
3e1d0bb6 338static int audit_set_backlog_wait_time(u32 timeout)
51cc83f0
RGB
339{
340 return audit_do_config_change("audit_backlog_wait_time",
a77ed4e5 341 &audit_backlog_wait_time_master, timeout);
51cc83f0
RGB
342}
343
3e1d0bb6 344static int audit_set_enabled(u32 state)
1a6b9f23 345{
b593d384 346 int rc;
724e7bfc 347 if (state > AUDIT_LOCKED)
1a6b9f23 348 return -EINVAL;
6a01b07f 349
dc9eb698 350 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
b593d384
EP
351 if (!rc)
352 audit_ever_enabled |= !!state;
353
354 return rc;
1da177e4
LT
355}
356
3e1d0bb6 357static int audit_set_failure(u32 state)
1da177e4 358{
1da177e4
LT
359 if (state != AUDIT_FAIL_SILENT
360 && state != AUDIT_FAIL_PRINTK
361 && state != AUDIT_FAIL_PANIC)
362 return -EINVAL;
ce29b682 363
dc9eb698 364 return audit_do_config_change("audit_failure", &audit_failure, state);
1da177e4
LT
365}
366
f3d357b0
EP
367/*
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.
375 */
376static void audit_hold_skb(struct sk_buff *skb)
377{
378 if (audit_default &&
40c0775e
RGB
379 (!audit_backlog_limit ||
380 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit))
f3d357b0
EP
381 skb_queue_tail(&audit_skb_hold_queue, skb);
382 else
383 kfree_skb(skb);
384}
385
038cbcf6
EP
386/*
387 * For one reason or another this nlh isn't getting delivered to the userspace
388 * audit daemon, just send it to printk.
389 */
390static void audit_printk_skb(struct sk_buff *skb)
391{
392 struct nlmsghdr *nlh = nlmsg_hdr(skb);
c64e66c6 393 char *data = nlmsg_data(nlh);
038cbcf6
EP
394
395 if (nlh->nlmsg_type != AUDIT_EOE) {
396 if (printk_ratelimit())
d957f7b7 397 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
038cbcf6 398 else
f1283527 399 audit_log_lost("printk limit exceeded");
038cbcf6
EP
400 }
401
402 audit_hold_skb(skb);
403}
404
f3d357b0
EP
405static void kauditd_send_skb(struct sk_buff *skb)
406{
407 int err;
32a1dbae
RGB
408 int attempts = 0;
409#define AUDITD_RETRIES 5
410
411restart:
f3d357b0
EP
412 /* take a reference in case we can't send it and we want to hold it */
413 skb_get(skb);
15e47304 414 err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
f3d357b0 415 if (err < 0) {
32a1dbae
RGB
416 pr_err("netlink_unicast sending to audit_pid=%d returned error: %d\n",
417 audit_pid, err);
04ee1a3b 418 if (audit_pid) {
32a1dbae
RGB
419 if (err == -ECONNREFUSED || err == -EPERM
420 || ++attempts >= AUDITD_RETRIES) {
421 char s[32];
422
423 snprintf(s, sizeof(s), "audit_pid=%d reset", audit_pid);
424 audit_log_lost(s);
425 audit_pid = 0;
426 audit_sock = NULL;
427 } else {
428 pr_warn("re-scheduling(#%d) write to audit_pid=%d\n",
429 attempts, audit_pid);
430 set_current_state(TASK_INTERRUPTIBLE);
431 schedule();
32a1dbae
RGB
432 goto restart;
433 }
04ee1a3b 434 }
f3d357b0
EP
435 /* we might get lucky and get this in the next auditd */
436 audit_hold_skb(skb);
437 } else
438 /* drop the extra reference if sent ok */
70d4bf6d 439 consume_skb(skb);
f3d357b0
EP
440}
441
451f9216
RGB
442/*
443 * kauditd_send_multicast_skb - send the skb to multicast userspace listeners
444 *
445 * This function doesn't consume an skb as might be expected since it has to
446 * copy it anyways.
447 */
54dc77d9 448static void kauditd_send_multicast_skb(struct sk_buff *skb, gfp_t gfp_mask)
451f9216
RGB
449{
450 struct sk_buff *copy;
451 struct audit_net *aunet = net_generic(&init_net, audit_net_id);
452 struct sock *sock = aunet->nlsk;
453
7f74ecd7
RGB
454 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
455 return;
456
451f9216
RGB
457 /*
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
465 * non-compliance.
466 */
54dc77d9 467 copy = skb_copy(skb, gfp_mask);
451f9216
RGB
468 if (!copy)
469 return;
470
54dc77d9 471 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, gfp_mask);
451f9216
RGB
472}
473
b551d1d9
RGB
474/*
475 * flush_hold_queue - empty the hold queue if auditd appears
476 *
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
481 * doesn't matter.
482 *
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.
488 */
489static void flush_hold_queue(void)
b7d11258
DW
490{
491 struct sk_buff *skb;
492
b551d1d9
RGB
493 if (!audit_default || !audit_pid)
494 return;
495
496 skb = skb_dequeue(&audit_skb_hold_queue);
497 if (likely(!skb))
498 return;
499
500 while (skb && audit_pid) {
501 kauditd_send_skb(skb);
502 skb = skb_dequeue(&audit_skb_hold_queue);
503 }
504
505 /*
506 * if auditd just disappeared but we
507 * dequeued an skb we need to drop ref
508 */
d865e573 509 consume_skb(skb);
b551d1d9
RGB
510}
511
97a41e26 512static int kauditd_thread(void *dummy)
b7d11258 513{
83144186 514 set_freezable();
4899b8b1 515 while (!kthread_should_stop()) {
3320c513 516 struct sk_buff *skb;
3320c513 517
b551d1d9 518 flush_hold_queue();
f3d357b0 519
b7d11258 520 skb = skb_dequeue(&audit_skb_queue);
db897319 521
b7d11258 522 if (skb) {
1194b994
RGB
523 if (!audit_backlog_limit ||
524 (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit))
db897319 525 wake_up(&audit_backlog_wait);
f3d357b0
EP
526 if (audit_pid)
527 kauditd_send_skb(skb);
038cbcf6
EP
528 else
529 audit_printk_skb(skb);
3320c513
RGB
530 continue;
531 }
b7d11258 532
6b55fc63 533 wait_event_freezable(kauditd_wait, skb_queue_len(&audit_skb_queue));
b7d11258 534 }
4899b8b1 535 return 0;
b7d11258
DW
536}
537
9044e6bc
AV
538int audit_send_list(void *_dest)
539{
540 struct audit_netlink_list *dest = _dest;
9044e6bc 541 struct sk_buff *skb;
48095d99 542 struct net *net = dest->net;
33faba7f 543 struct audit_net *aunet = net_generic(net, audit_net_id);
9044e6bc
AV
544
545 /* wait for parent to finish and send an ACK */
f368c07d
AG
546 mutex_lock(&audit_cmd_mutex);
547 mutex_unlock(&audit_cmd_mutex);
9044e6bc
AV
548
549 while ((skb = __skb_dequeue(&dest->q)) != NULL)
33faba7f 550 netlink_unicast(aunet->nlsk, skb, dest->portid, 0);
9044e6bc 551
48095d99 552 put_net(net);
9044e6bc
AV
553 kfree(dest);
554
555 return 0;
556}
557
f9441639 558struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done,
b8800aa5 559 int multi, const void *payload, int size)
9044e6bc
AV
560{
561 struct sk_buff *skb;
562 struct nlmsghdr *nlh;
9044e6bc
AV
563 void *data;
564 int flags = multi ? NLM_F_MULTI : 0;
565 int t = done ? NLMSG_DONE : type;
566
ee080e6c 567 skb = nlmsg_new(size, GFP_KERNEL);
9044e6bc
AV
568 if (!skb)
569 return NULL;
570
f9441639 571 nlh = nlmsg_put(skb, portid, seq, t, size, flags);
c64e66c6
DM
572 if (!nlh)
573 goto out_kfree_skb;
574 data = nlmsg_data(nlh);
9044e6bc
AV
575 memcpy(data, payload, size);
576 return skb;
577
c64e66c6
DM
578out_kfree_skb:
579 kfree_skb(skb);
9044e6bc
AV
580 return NULL;
581}
582
f09ac9db
EP
583static int audit_send_reply_thread(void *arg)
584{
585 struct audit_reply *reply = (struct audit_reply *)arg;
48095d99 586 struct net *net = reply->net;
33faba7f 587 struct audit_net *aunet = net_generic(net, audit_net_id);
f09ac9db
EP
588
589 mutex_lock(&audit_cmd_mutex);
590 mutex_unlock(&audit_cmd_mutex);
591
592 /* Ignore failure. It'll only happen if the sender goes away,
593 because our timeout is set to infinite. */
33faba7f 594 netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0);
48095d99 595 put_net(net);
f09ac9db
EP
596 kfree(reply);
597 return 0;
598}
b0dd25a8
RD
599/**
600 * audit_send_reply - send an audit reply message via netlink
d211f177 601 * @request_skb: skb of request we are replying to (used to target the reply)
b0dd25a8
RD
602 * @seq: sequence number
603 * @type: audit message type
604 * @done: done (last) flag
605 * @multi: multi-part message flag
606 * @payload: payload data
607 * @size: payload size
608 *
f9441639 609 * Allocates an skb, builds the netlink message, and sends it to the port id.
b0dd25a8
RD
610 * No failure notifications.
611 */
6f285b19 612static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
f9441639 613 int multi, const void *payload, int size)
1da177e4 614{
6f285b19
EB
615 u32 portid = NETLINK_CB(request_skb).portid;
616 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
f09ac9db
EP
617 struct sk_buff *skb;
618 struct task_struct *tsk;
619 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
620 GFP_KERNEL);
621
622 if (!reply)
623 return;
624
f9441639 625 skb = audit_make_reply(portid, seq, type, done, multi, payload, size);
1da177e4 626 if (!skb)
fcaf1eb8 627 goto out;
f09ac9db 628
6f285b19 629 reply->net = get_net(net);
f9441639 630 reply->portid = portid;
f09ac9db
EP
631 reply->skb = skb;
632
633 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
fcaf1eb8
AM
634 if (!IS_ERR(tsk))
635 return;
636 kfree_skb(skb);
637out:
638 kfree(reply);
1da177e4
LT
639}
640
641/*
642 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
643 * control messages.
644 */
c7bdb545 645static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
1da177e4
LT
646{
647 int err = 0;
648
5a3cb3b6 649 /* Only support initial user namespace for now. */
aa4af831
EP
650 /*
651 * We return ECONNREFUSED because it tricks userspace into thinking
652 * that audit was not configured into the kernel. Lots of users
653 * configure their PAM stack (because that's what the distro does)
654 * to reject login if unable to send messages to audit. If we return
655 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
656 * configured in and will let login proceed. If we return EPERM
657 * userspace will reject all logins. This should be removed when we
658 * support non init namespaces!!
659 */
0b747172 660 if (current_user_ns() != &init_user_ns)
aa4af831 661 return -ECONNREFUSED;
34e36d8e 662
1da177e4 663 switch (msg_type) {
1da177e4 664 case AUDIT_LIST:
1da177e4
LT
665 case AUDIT_ADD:
666 case AUDIT_DEL:
18900909
EP
667 return -EOPNOTSUPP;
668 case AUDIT_GET:
669 case AUDIT_SET:
b0fed402
EP
670 case AUDIT_GET_FEATURE:
671 case AUDIT_SET_FEATURE:
18900909
EP
672 case AUDIT_LIST_RULES:
673 case AUDIT_ADD_RULE:
93315ed6 674 case AUDIT_DEL_RULE:
c2f0c7c3 675 case AUDIT_SIGNAL_INFO:
522ed776
MT
676 case AUDIT_TTY_GET:
677 case AUDIT_TTY_SET:
74c3cbe3
AV
678 case AUDIT_TRIM:
679 case AUDIT_MAKE_EQUIV:
5a3cb3b6
RGB
680 /* Only support auditd and auditctl in initial pid namespace
681 * for now. */
5985de67 682 if (task_active_pid_ns(current) != &init_pid_ns)
5a3cb3b6
RGB
683 return -EPERM;
684
90f62cf3 685 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
1da177e4
LT
686 err = -EPERM;
687 break;
05474106 688 case AUDIT_USER:
039b6b3e
RD
689 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
690 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
90f62cf3 691 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
1da177e4
LT
692 err = -EPERM;
693 break;
694 default: /* bad msg */
695 err = -EINVAL;
696 }
697
698 return err;
699}
700
233a6866 701static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
50397bd1 702{
dc9eb698 703 uid_t uid = from_kuid(&init_user_ns, current_uid());
f1dc4867 704 pid_t pid = task_tgid_nr(current);
50397bd1 705
0868a5e1 706 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
50397bd1 707 *ab = NULL;
233a6866 708 return;
50397bd1
EP
709 }
710
711 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
0644ec0c 712 if (unlikely(!*ab))
233a6866 713 return;
f1dc4867 714 audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
4d3fb709 715 audit_log_session_info(*ab);
b122c376 716 audit_log_task_context(*ab);
50397bd1
EP
717}
718
b0fed402
EP
719int is_audit_feature_set(int i)
720{
721 return af.features & AUDIT_FEATURE_TO_MASK(i);
722}
723
724
725static int audit_get_feature(struct sk_buff *skb)
726{
727 u32 seq;
728
729 seq = nlmsg_hdr(skb)->nlmsg_seq;
730
9ef91514 731 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
b0fed402
EP
732
733 return 0;
734}
735
736static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
737 u32 old_lock, u32 new_lock, int res)
738{
739 struct audit_buffer *ab;
740
b6c50fe0
G
741 if (audit_enabled == AUDIT_OFF)
742 return;
743
b0fed402 744 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE);
ad2ac263 745 audit_log_task_info(ab, current);
897f1acb 746 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
b0fed402
EP
747 audit_feature_names[which], !!old_feature, !!new_feature,
748 !!old_lock, !!new_lock, res);
749 audit_log_end(ab);
750}
751
752static int audit_set_feature(struct sk_buff *skb)
753{
754 struct audit_features *uaf;
755 int i;
756
6eed9b26 757 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
b0fed402
EP
758 uaf = nlmsg_data(nlmsg_hdr(skb));
759
760 /* if there is ever a version 2 we should handle that here */
761
762 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
763 u32 feature = AUDIT_FEATURE_TO_MASK(i);
764 u32 old_feature, new_feature, old_lock, new_lock;
765
766 /* if we are not changing this feature, move along */
767 if (!(feature & uaf->mask))
768 continue;
769
770 old_feature = af.features & feature;
771 new_feature = uaf->features & feature;
772 new_lock = (uaf->lock | af.lock) & feature;
773 old_lock = af.lock & feature;
774
775 /* are we changing a locked feature? */
4547b3bc 776 if (old_lock && (new_feature != old_feature)) {
b0fed402
EP
777 audit_log_feature_change(i, old_feature, new_feature,
778 old_lock, new_lock, 0);
779 return -EPERM;
780 }
781 }
782 /* nothing invalid, do the changes */
783 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
784 u32 feature = AUDIT_FEATURE_TO_MASK(i);
785 u32 old_feature, new_feature, old_lock, new_lock;
786
787 /* if we are not changing this feature, move along */
788 if (!(feature & uaf->mask))
789 continue;
790
791 old_feature = af.features & feature;
792 new_feature = uaf->features & feature;
793 old_lock = af.lock & feature;
794 new_lock = (uaf->lock | af.lock) & feature;
795
796 if (new_feature != old_feature)
797 audit_log_feature_change(i, old_feature, new_feature,
798 old_lock, new_lock, 1);
799
800 if (new_feature)
801 af.features |= feature;
802 else
803 af.features &= ~feature;
804 af.lock |= new_lock;
805 }
806
807 return 0;
808}
809
133e1e5a
RGB
810static int audit_replace(pid_t pid)
811{
812 struct sk_buff *skb = audit_make_reply(0, 0, AUDIT_REPLACE, 0, 0,
813 &pid, sizeof(pid));
814
815 if (!skb)
816 return -ENOMEM;
817 return netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
818}
819
1da177e4
LT
820static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
821{
dc9eb698 822 u32 seq;
1da177e4 823 void *data;
1da177e4 824 int err;
c0404993 825 struct audit_buffer *ab;
1da177e4 826 u16 msg_type = nlh->nlmsg_type;
e1396065 827 struct audit_sig_info *sig_data;
50397bd1 828 char *ctx = NULL;
e1396065 829 u32 len;
1da177e4 830
c7bdb545 831 err = audit_netlink_ok(skb, msg_type);
1da177e4
LT
832 if (err)
833 return err;
834
b0dd25a8
RD
835 /* As soon as there's any sign of userspace auditd,
836 * start kauditd to talk to it */
13f51e1c 837 if (!kauditd_task) {
b7d11258 838 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
13f51e1c
G
839 if (IS_ERR(kauditd_task)) {
840 err = PTR_ERR(kauditd_task);
841 kauditd_task = NULL;
842 return err;
843 }
b7d11258 844 }
1da177e4 845 seq = nlh->nlmsg_seq;
c64e66c6 846 data = nlmsg_data(nlh);
1da177e4
LT
847
848 switch (msg_type) {
09f883a9
RGB
849 case AUDIT_GET: {
850 struct audit_status s;
851 memset(&s, 0, sizeof(s));
852 s.enabled = audit_enabled;
853 s.failure = audit_failure;
854 s.pid = audit_pid;
855 s.rate_limit = audit_rate_limit;
856 s.backlog_limit = audit_backlog_limit;
857 s.lost = atomic_read(&audit_lost);
858 s.backlog = skb_queue_len(&audit_skb_queue);
0288d718 859 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
a77ed4e5 860 s.backlog_wait_time = audit_backlog_wait_time_master;
6f285b19 861 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
1da177e4 862 break;
09f883a9
RGB
863 }
864 case AUDIT_SET: {
865 struct audit_status s;
866 memset(&s, 0, sizeof(s));
867 /* guard against past and future API changes */
868 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
869 if (s.mask & AUDIT_STATUS_ENABLED) {
870 err = audit_set_enabled(s.enabled);
20c6aaa3 871 if (err < 0)
872 return err;
1da177e4 873 }
09f883a9
RGB
874 if (s.mask & AUDIT_STATUS_FAILURE) {
875 err = audit_set_failure(s.failure);
20c6aaa3 876 if (err < 0)
877 return err;
1da177e4 878 }
09f883a9
RGB
879 if (s.mask & AUDIT_STATUS_PID) {
880 int new_pid = s.pid;
133e1e5a 881 pid_t requesting_pid = task_tgid_vnr(current);
1a6b9f23 882
935c9e7f
RGB
883 if ((!new_pid) && (requesting_pid != audit_pid)) {
884 audit_log_config_change("audit_pid", new_pid, audit_pid, 0);
34eab0a7 885 return -EACCES;
935c9e7f 886 }
133e1e5a 887 if (audit_pid && new_pid &&
935c9e7f
RGB
888 audit_replace(requesting_pid) != -ECONNREFUSED) {
889 audit_log_config_change("audit_pid", new_pid, audit_pid, 0);
133e1e5a 890 return -EEXIST;
935c9e7f 891 }
1a6b9f23 892 if (audit_enabled != AUDIT_OFF)
dc9eb698 893 audit_log_config_change("audit_pid", new_pid, audit_pid, 1);
1a6b9f23 894 audit_pid = new_pid;
15e47304 895 audit_nlk_portid = NETLINK_CB(skb).portid;
de92fc97 896 audit_sock = skb->sk;
1da177e4 897 }
09f883a9
RGB
898 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
899 err = audit_set_rate_limit(s.rate_limit);
20c6aaa3 900 if (err < 0)
901 return err;
902 }
51cc83f0 903 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
09f883a9 904 err = audit_set_backlog_limit(s.backlog_limit);
51cc83f0
RGB
905 if (err < 0)
906 return err;
907 }
3f0c5fad
EP
908 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
909 if (sizeof(s) > (size_t)nlh->nlmsg_len)
910 return -EINVAL;
724e7bfc 911 if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
3f0c5fad
EP
912 return -EINVAL;
913 err = audit_set_backlog_wait_time(s.backlog_wait_time);
914 if (err < 0)
915 return err;
51cc83f0 916 }
1da177e4 917 break;
09f883a9 918 }
b0fed402
EP
919 case AUDIT_GET_FEATURE:
920 err = audit_get_feature(skb);
921 if (err)
922 return err;
923 break;
924 case AUDIT_SET_FEATURE:
925 err = audit_set_feature(skb);
926 if (err)
927 return err;
928 break;
05474106 929 case AUDIT_USER:
039b6b3e
RD
930 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
931 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
4a4cd633
DW
932 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
933 return 0;
934
86b2efbe 935 err = audit_filter(msg_type, AUDIT_FILTER_USER);
724e4fcc 936 if (err == 1) { /* match or error */
4a4cd633 937 err = 0;
522ed776 938 if (msg_type == AUDIT_USER_TTY) {
37282a77 939 err = tty_audit_push();
522ed776
MT
940 if (err)
941 break;
942 }
1b7b533f 943 mutex_unlock(&audit_cmd_mutex);
dc9eb698 944 audit_log_common_recv_msg(&ab, msg_type);
50397bd1 945 if (msg_type != AUDIT_USER_TTY)
b50eba7e
RGB
946 audit_log_format(ab, " msg='%.*s'",
947 AUDIT_MESSAGE_TEXT_MAX,
50397bd1
EP
948 (char *)data);
949 else {
950 int size;
951
f7616102 952 audit_log_format(ab, " data=");
50397bd1 953 size = nlmsg_len(nlh);
55ad2f8d
MT
954 if (size > 0 &&
955 ((unsigned char *)data)[size - 1] == '\0')
956 size--;
b556f8ad 957 audit_log_n_untrustedstring(ab, data, size);
4a4cd633 958 }
f9441639 959 audit_set_portid(ab, NETLINK_CB(skb).portid);
50397bd1 960 audit_log_end(ab);
1b7b533f 961 mutex_lock(&audit_cmd_mutex);
0f45aa18 962 }
1da177e4 963 break;
93315ed6
AG
964 case AUDIT_ADD_RULE:
965 case AUDIT_DEL_RULE:
966 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
967 return -EINVAL;
1a6b9f23 968 if (audit_enabled == AUDIT_LOCKED) {
dc9eb698
EP
969 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
970 audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
50397bd1 971 audit_log_end(ab);
6a01b07f
SG
972 return -EPERM;
973 }
ce0d9f04 974 err = audit_rule_change(msg_type, NETLINK_CB(skb).portid,
dc9eb698 975 seq, data, nlmsg_len(nlh));
1da177e4 976 break;
ce0d9f04 977 case AUDIT_LIST_RULES:
6f285b19 978 err = audit_list_rules_send(skb, seq);
ce0d9f04 979 break;
74c3cbe3
AV
980 case AUDIT_TRIM:
981 audit_trim_trees();
dc9eb698 982 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
74c3cbe3
AV
983 audit_log_format(ab, " op=trim res=1");
984 audit_log_end(ab);
985 break;
986 case AUDIT_MAKE_EQUIV: {
987 void *bufp = data;
988 u32 sizes[2];
7719e437 989 size_t msglen = nlmsg_len(nlh);
74c3cbe3
AV
990 char *old, *new;
991
992 err = -EINVAL;
7719e437 993 if (msglen < 2 * sizeof(u32))
74c3cbe3
AV
994 break;
995 memcpy(sizes, bufp, 2 * sizeof(u32));
996 bufp += 2 * sizeof(u32);
7719e437
HH
997 msglen -= 2 * sizeof(u32);
998 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
74c3cbe3
AV
999 if (IS_ERR(old)) {
1000 err = PTR_ERR(old);
1001 break;
1002 }
7719e437 1003 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
74c3cbe3
AV
1004 if (IS_ERR(new)) {
1005 err = PTR_ERR(new);
1006 kfree(old);
1007 break;
1008 }
1009 /* OK, here comes... */
1010 err = audit_tag_tree(old, new);
1011
dc9eb698 1012 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
50397bd1 1013
74c3cbe3
AV
1014 audit_log_format(ab, " op=make_equiv old=");
1015 audit_log_untrustedstring(ab, old);
1016 audit_log_format(ab, " new=");
1017 audit_log_untrustedstring(ab, new);
1018 audit_log_format(ab, " res=%d", !err);
1019 audit_log_end(ab);
1020 kfree(old);
1021 kfree(new);
1022 break;
1023 }
c2f0c7c3 1024 case AUDIT_SIGNAL_INFO:
939cbf26
EP
1025 len = 0;
1026 if (audit_sig_sid) {
1027 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1028 if (err)
1029 return err;
1030 }
e1396065
AV
1031 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1032 if (!sig_data) {
939cbf26
EP
1033 if (audit_sig_sid)
1034 security_release_secctx(ctx, len);
e1396065
AV
1035 return -ENOMEM;
1036 }
cca080d9 1037 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
e1396065 1038 sig_data->pid = audit_sig_pid;
939cbf26
EP
1039 if (audit_sig_sid) {
1040 memcpy(sig_data->ctx, ctx, len);
1041 security_release_secctx(ctx, len);
1042 }
6f285b19
EB
1043 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1044 sig_data, sizeof(*sig_data) + len);
e1396065 1045 kfree(sig_data);
c2f0c7c3 1046 break;
522ed776
MT
1047 case AUDIT_TTY_GET: {
1048 struct audit_tty_status s;
2e28d38a 1049 unsigned int t;
8aa14b64 1050
2e28d38a
PH
1051 t = READ_ONCE(current->signal->audit_tty);
1052 s.enabled = t & AUDIT_TTY_ENABLE;
1053 s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
8aa14b64 1054
6f285b19 1055 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
522ed776
MT
1056 break;
1057 }
1058 case AUDIT_TTY_SET: {
a06e56b2 1059 struct audit_tty_status s, old;
a06e56b2 1060 struct audit_buffer *ab;
2e28d38a 1061 unsigned int t;
0e23bacc
EP
1062
1063 memset(&s, 0, sizeof(s));
1064 /* guard against past and future API changes */
1065 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
1066 /* check if new data is valid */
1067 if ((s.enabled != 0 && s.enabled != 1) ||
1068 (s.log_passwd != 0 && s.log_passwd != 1))
1069 err = -EINVAL;
a06e56b2 1070
2e28d38a
PH
1071 if (err)
1072 t = READ_ONCE(current->signal->audit_tty);
1073 else {
1074 t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
1075 t = xchg(&current->signal->audit_tty, t);
0e23bacc 1076 }
2e28d38a
PH
1077 old.enabled = t & AUDIT_TTY_ENABLE;
1078 old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
522ed776 1079
a06e56b2 1080 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1ce319f1
EP
1081 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1082 " old-log_passwd=%d new-log_passwd=%d res=%d",
1083 old.enabled, s.enabled, old.log_passwd,
1084 s.log_passwd, !err);
a06e56b2 1085 audit_log_end(ab);
522ed776
MT
1086 break;
1087 }
1da177e4
LT
1088 default:
1089 err = -EINVAL;
1090 break;
1091 }
1092
1093 return err < 0 ? err : 0;
1094}
1095
b0dd25a8 1096/*
ea7ae60b
EP
1097 * Get message from skb. Each message is processed by audit_receive_msg.
1098 * Malformed skbs with wrong length are discarded silently.
b0dd25a8 1099 */
2a0a6ebe 1100static void audit_receive_skb(struct sk_buff *skb)
1da177e4 1101{
ea7ae60b
EP
1102 struct nlmsghdr *nlh;
1103 /*
94191213 1104 * len MUST be signed for nlmsg_next to be able to dec it below 0
ea7ae60b
EP
1105 * if the nlmsg_len was not aligned
1106 */
1107 int len;
1108 int err;
1109
1110 nlh = nlmsg_hdr(skb);
1111 len = skb->len;
1112
94191213 1113 while (nlmsg_ok(nlh, len)) {
ea7ae60b
EP
1114 err = audit_receive_msg(skb, nlh);
1115 /* if err or if this message says it wants a response */
1116 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1da177e4 1117 netlink_ack(skb, nlh, err);
ea7ae60b 1118
2851da57 1119 nlh = nlmsg_next(nlh, &len);
1da177e4 1120 }
1da177e4
LT
1121}
1122
1123/* Receive messages from netlink socket. */
cd40b7d3 1124static void audit_receive(struct sk_buff *skb)
1da177e4 1125{
f368c07d 1126 mutex_lock(&audit_cmd_mutex);
cd40b7d3 1127 audit_receive_skb(skb);
f368c07d 1128 mutex_unlock(&audit_cmd_mutex);
1da177e4
LT
1129}
1130
3a101b8d 1131/* Run custom bind function on netlink socket group connect or bind requests. */
023e2cfa 1132static int audit_bind(struct net *net, int group)
3a101b8d
RGB
1133{
1134 if (!capable(CAP_AUDIT_READ))
1135 return -EPERM;
1136
1137 return 0;
1138}
1139
33faba7f 1140static int __net_init audit_net_init(struct net *net)
1da177e4 1141{
a31f2d17
PNA
1142 struct netlink_kernel_cfg cfg = {
1143 .input = audit_receive,
3a101b8d 1144 .bind = audit_bind,
451f9216
RGB
1145 .flags = NL_CFG_F_NONROOT_RECV,
1146 .groups = AUDIT_NLGRP_MAX,
a31f2d17 1147 };
f368c07d 1148
33faba7f
RGB
1149 struct audit_net *aunet = net_generic(net, audit_net_id);
1150
33faba7f 1151 aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
11ee39eb 1152 if (aunet->nlsk == NULL) {
33faba7f 1153 audit_panic("cannot initialize netlink socket in namespace");
11ee39eb
G
1154 return -ENOMEM;
1155 }
1156 aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
33faba7f
RGB
1157 return 0;
1158}
1159
1160static void __net_exit audit_net_exit(struct net *net)
1161{
1162 struct audit_net *aunet = net_generic(net, audit_net_id);
1163 struct sock *sock = aunet->nlsk;
1164 if (sock == audit_sock) {
1165 audit_pid = 0;
1166 audit_sock = NULL;
1167 }
1168
e231d54c 1169 RCU_INIT_POINTER(aunet->nlsk, NULL);
33faba7f
RGB
1170 synchronize_net();
1171 netlink_kernel_release(sock);
1172}
1173
8626877b 1174static struct pernet_operations audit_net_ops __net_initdata = {
33faba7f
RGB
1175 .init = audit_net_init,
1176 .exit = audit_net_exit,
1177 .id = &audit_net_id,
1178 .size = sizeof(struct audit_net),
1179};
1180
1181/* Initialize audit support at boot time. */
1182static int __init audit_init(void)
1183{
1184 int i;
1185
a3f07114
EP
1186 if (audit_initialized == AUDIT_DISABLED)
1187 return 0;
1188
d957f7b7
JP
1189 pr_info("initializing netlink subsys (%s)\n",
1190 audit_default ? "enabled" : "disabled");
33faba7f 1191 register_pernet_subsys(&audit_net_ops);
1da177e4 1192
b7d11258 1193 skb_queue_head_init(&audit_skb_queue);
f3d357b0 1194 skb_queue_head_init(&audit_skb_hold_queue);
a3f07114 1195 audit_initialized = AUDIT_INITIALIZED;
1da177e4 1196 audit_enabled = audit_default;
b593d384 1197 audit_ever_enabled |= !!audit_default;
3dc7e315 1198
9ad9ad38 1199 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
f368c07d 1200
f368c07d
AG
1201 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1202 INIT_LIST_HEAD(&audit_inode_hash[i]);
f368c07d 1203
1da177e4
LT
1204 return 0;
1205}
1da177e4
LT
1206__initcall(audit_init);
1207
1208/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1209static int __init audit_enable(char *str)
1210{
1211 audit_default = !!simple_strtol(str, NULL, 0);
a3f07114
EP
1212 if (!audit_default)
1213 audit_initialized = AUDIT_DISABLED;
1214
d957f7b7 1215 pr_info("%s\n", audit_default ?
d3ca0344 1216 "enabled (after initialization)" : "disabled (until reboot)");
a3f07114 1217
9b41046c 1218 return 1;
1da177e4 1219}
1da177e4
LT
1220__setup("audit=", audit_enable);
1221
f910fde7
RGB
1222/* Process kernel command-line parameter at boot time.
1223 * audit_backlog_limit=<n> */
1224static int __init audit_backlog_limit_set(char *str)
1225{
3e1d0bb6 1226 u32 audit_backlog_limit_arg;
d957f7b7 1227
f910fde7 1228 pr_info("audit_backlog_limit: ");
3e1d0bb6
JP
1229 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1230 pr_cont("using default of %u, unable to parse %s\n",
d957f7b7 1231 audit_backlog_limit, str);
f910fde7
RGB
1232 return 1;
1233 }
3e1d0bb6
JP
1234
1235 audit_backlog_limit = audit_backlog_limit_arg;
d957f7b7 1236 pr_cont("%d\n", audit_backlog_limit);
f910fde7
RGB
1237
1238 return 1;
1239}
1240__setup("audit_backlog_limit=", audit_backlog_limit_set);
1241
16e1904e
CW
1242static void audit_buffer_free(struct audit_buffer *ab)
1243{
1244 unsigned long flags;
1245
8fc6115c
CW
1246 if (!ab)
1247 return;
1248
d865e573 1249 kfree_skb(ab->skb);
16e1904e 1250 spin_lock_irqsave(&audit_freelist_lock, flags);
5d136a01 1251 if (audit_freelist_count > AUDIT_MAXFREE)
16e1904e 1252 kfree(ab);
5d136a01
SH
1253 else {
1254 audit_freelist_count++;
16e1904e 1255 list_add(&ab->list, &audit_freelist);
5d136a01 1256 }
16e1904e
CW
1257 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1258}
1259
c0404993 1260static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
dd0fc66f 1261 gfp_t gfp_mask, int type)
16e1904e
CW
1262{
1263 unsigned long flags;
1264 struct audit_buffer *ab = NULL;
c0404993 1265 struct nlmsghdr *nlh;
16e1904e
CW
1266
1267 spin_lock_irqsave(&audit_freelist_lock, flags);
1268 if (!list_empty(&audit_freelist)) {
1269 ab = list_entry(audit_freelist.next,
1270 struct audit_buffer, list);
1271 list_del(&ab->list);
1272 --audit_freelist_count;
1273 }
1274 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1275
1276 if (!ab) {
4332bdd3 1277 ab = kmalloc(sizeof(*ab), gfp_mask);
16e1904e 1278 if (!ab)
8fc6115c 1279 goto err;
16e1904e 1280 }
8fc6115c 1281
b7d11258 1282 ab->ctx = ctx;
9ad9ad38 1283 ab->gfp_mask = gfp_mask;
ee080e6c
EP
1284
1285 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1286 if (!ab->skb)
c64e66c6 1287 goto err;
ee080e6c 1288
c64e66c6
DM
1289 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1290 if (!nlh)
1291 goto out_kfree_skb;
ee080e6c 1292
16e1904e 1293 return ab;
ee080e6c 1294
c64e66c6 1295out_kfree_skb:
ee080e6c
EP
1296 kfree_skb(ab->skb);
1297 ab->skb = NULL;
8fc6115c
CW
1298err:
1299 audit_buffer_free(ab);
1300 return NULL;
16e1904e 1301}
1da177e4 1302
b0dd25a8
RD
1303/**
1304 * audit_serial - compute a serial number for the audit record
1305 *
1306 * Compute a serial number for the audit record. Audit records are
bfb4496e
DW
1307 * written to user-space as soon as they are generated, so a complete
1308 * audit record may be written in several pieces. The timestamp of the
1309 * record and this serial number are used by the user-space tools to
1310 * determine which pieces belong to the same audit record. The
1311 * (timestamp,serial) tuple is unique for each syscall and is live from
1312 * syscall entry to syscall exit.
1313 *
bfb4496e
DW
1314 * NOTE: Another possibility is to store the formatted records off the
1315 * audit context (for those records that have a context), and emit them
1316 * all at syscall exit. However, this could delay the reporting of
1317 * significant errors until syscall exit (or never, if the system
b0dd25a8
RD
1318 * halts).
1319 */
bfb4496e
DW
1320unsigned int audit_serial(void)
1321{
01478d7d 1322 static atomic_t serial = ATOMIC_INIT(0);
d5b454f2 1323
01478d7d 1324 return atomic_add_return(1, &serial);
bfb4496e
DW
1325}
1326
5600b892 1327static inline void audit_get_stamp(struct audit_context *ctx,
bfb4496e
DW
1328 struct timespec *t, unsigned int *serial)
1329{
48887e63 1330 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
bfb4496e
DW
1331 *t = CURRENT_TIME;
1332 *serial = audit_serial();
1333 }
1334}
1335
82919919
AM
1336/*
1337 * Wait for auditd to drain the queue a little
1338 */
c81825dd 1339static long wait_for_auditd(long sleep_time)
82919919
AM
1340{
1341 DECLARE_WAITQUEUE(wait, current);
82919919
AM
1342
1343 if (audit_backlog_limit &&
7ffb8e31
PM
1344 skb_queue_len(&audit_skb_queue) > audit_backlog_limit) {
1345 add_wait_queue_exclusive(&audit_backlog_wait, &wait);
1346 set_current_state(TASK_UNINTERRUPTIBLE);
c81825dd 1347 sleep_time = schedule_timeout(sleep_time);
7ffb8e31
PM
1348 remove_wait_queue(&audit_backlog_wait, &wait);
1349 }
ae887e0b 1350
c81825dd 1351 return sleep_time;
82919919
AM
1352}
1353
b0dd25a8
RD
1354/**
1355 * audit_log_start - obtain an audit buffer
1356 * @ctx: audit_context (may be NULL)
1357 * @gfp_mask: type of allocation
1358 * @type: audit message type
1359 *
1360 * Returns audit_buffer pointer on success or NULL on error.
1361 *
1362 * Obtain an audit buffer. This routine does locking to obtain the
1363 * audit buffer, but then no locking is required for calls to
1364 * audit_log_*format. If the task (ctx) is a task that is currently in a
1365 * syscall, then the syscall is marked as auditable and an audit record
1366 * will be written at syscall exit. If there is no associated task, then
1367 * task context (ctx) should be NULL.
1368 */
9796fdd8 1369struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
9ad9ad38 1370 int type)
1da177e4
LT
1371{
1372 struct audit_buffer *ab = NULL;
1da177e4 1373 struct timespec t;
ef00be05 1374 unsigned int uninitialized_var(serial);
6dd80aba
TO
1375 int reserve = 5; /* Allow atomic callers to go up to five
1376 entries over the normal backlog limit */
ac4cec44 1377 unsigned long timeout_start = jiffies;
1da177e4 1378
a3f07114 1379 if (audit_initialized != AUDIT_INITIALIZED)
1da177e4
LT
1380 return NULL;
1381
86b2efbe 1382 if (unlikely(!audit_filter(type, AUDIT_FILTER_TYPE)))
c8edc80c
DK
1383 return NULL;
1384
d0164adc 1385 if (gfp_mask & __GFP_DIRECT_RECLAIM) {
f48a9429 1386 if (audit_pid && audit_pid == current->tgid)
d0164adc 1387 gfp_mask &= ~__GFP_DIRECT_RECLAIM;
6dd80aba
TO
1388 else
1389 reserve = 0;
1390 }
9ad9ad38
DW
1391
1392 while (audit_backlog_limit
1393 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
d0164adc 1394 if (gfp_mask & __GFP_DIRECT_RECLAIM && audit_backlog_wait_time) {
c81825dd 1395 long sleep_time;
9ad9ad38 1396
c81825dd
EP
1397 sleep_time = timeout_start + audit_backlog_wait_time - jiffies;
1398 if (sleep_time > 0) {
ae887e0b 1399 sleep_time = wait_for_auditd(sleep_time);
c81825dd 1400 if (sleep_time > 0)
ae887e0b 1401 continue;
8ac1c8d5 1402 }
9ad9ad38 1403 }
320f1b1e 1404 if (audit_rate_check() && printk_ratelimit())
d957f7b7
JP
1405 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1406 skb_queue_len(&audit_skb_queue),
1407 audit_backlog_limit);
fb19b4c6 1408 audit_log_lost("backlog limit exceeded");
eb8baf6a 1409 audit_backlog_wait_time = 0;
ac4cec44 1410 wake_up(&audit_backlog_wait);
fb19b4c6
DW
1411 return NULL;
1412 }
1413
c4b7a775 1414 if (!reserve && !audit_backlog_wait_time)
efef73a1 1415 audit_backlog_wait_time = audit_backlog_wait_time_master;
e789e561 1416
9ad9ad38 1417 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1da177e4
LT
1418 if (!ab) {
1419 audit_log_lost("out of memory in audit_log_start");
1420 return NULL;
1421 }
1422
bfb4496e 1423 audit_get_stamp(ab->ctx, &t, &serial);
197c69c6 1424
1da177e4
LT
1425 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1426 t.tv_sec, t.tv_nsec/1000000, serial);
1427 return ab;
1428}
1429
8fc6115c 1430/**
5ac52f33 1431 * audit_expand - expand skb in the audit buffer
8fc6115c 1432 * @ab: audit_buffer
b0dd25a8 1433 * @extra: space to add at tail of the skb
8fc6115c
CW
1434 *
1435 * Returns 0 (no space) on failed expansion, or available space if
1436 * successful.
1437 */
e3b926b4 1438static inline int audit_expand(struct audit_buffer *ab, int extra)
8fc6115c 1439{
5ac52f33 1440 struct sk_buff *skb = ab->skb;
406a1d86
HX
1441 int oldtail = skb_tailroom(skb);
1442 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1443 int newtail = skb_tailroom(skb);
1444
5ac52f33
CW
1445 if (ret < 0) {
1446 audit_log_lost("out of memory in audit_expand");
8fc6115c 1447 return 0;
5ac52f33 1448 }
406a1d86
HX
1449
1450 skb->truesize += newtail - oldtail;
1451 return newtail;
8fc6115c 1452}
1da177e4 1453
b0dd25a8
RD
1454/*
1455 * Format an audit message into the audit buffer. If there isn't enough
1da177e4
LT
1456 * room in the audit buffer, more room will be allocated and vsnprint
1457 * will be called a second time. Currently, we assume that a printk
b0dd25a8
RD
1458 * can't format message larger than 1024 bytes, so we don't either.
1459 */
1da177e4
LT
1460static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1461 va_list args)
1462{
1463 int len, avail;
5ac52f33 1464 struct sk_buff *skb;
eecb0a73 1465 va_list args2;
1da177e4
LT
1466
1467 if (!ab)
1468 return;
1469
5ac52f33
CW
1470 BUG_ON(!ab->skb);
1471 skb = ab->skb;
1472 avail = skb_tailroom(skb);
1473 if (avail == 0) {
e3b926b4 1474 avail = audit_expand(ab, AUDIT_BUFSIZ);
8fc6115c
CW
1475 if (!avail)
1476 goto out;
1da177e4 1477 }
eecb0a73 1478 va_copy(args2, args);
27a884dc 1479 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1da177e4
LT
1480 if (len >= avail) {
1481 /* The printk buffer is 1024 bytes long, so if we get
1482 * here and AUDIT_BUFSIZ is at least 1024, then we can
1483 * log everything that printk could have logged. */
b0dd25a8
RD
1484 avail = audit_expand(ab,
1485 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
8fc6115c 1486 if (!avail)
a0e86bd4 1487 goto out_va_end;
27a884dc 1488 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1da177e4 1489 }
168b7173
SG
1490 if (len > 0)
1491 skb_put(skb, len);
a0e86bd4
JJ
1492out_va_end:
1493 va_end(args2);
8fc6115c
CW
1494out:
1495 return;
1da177e4
LT
1496}
1497
b0dd25a8
RD
1498/**
1499 * audit_log_format - format a message into the audit buffer.
1500 * @ab: audit_buffer
1501 * @fmt: format string
1502 * @...: optional parameters matching @fmt string
1503 *
1504 * All the work is done in audit_log_vformat.
1505 */
1da177e4
LT
1506void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1507{
1508 va_list args;
1509
1510 if (!ab)
1511 return;
1512 va_start(args, fmt);
1513 audit_log_vformat(ab, fmt, args);
1514 va_end(args);
1515}
1516
b0dd25a8
RD
1517/**
1518 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1519 * @ab: the audit_buffer
1520 * @buf: buffer to convert to hex
1521 * @len: length of @buf to be converted
1522 *
1523 * No return value; failure to expand is silently ignored.
1524 *
1525 * This function will take the passed buf and convert it into a string of
1526 * ascii hex digits. The new string is placed onto the skb.
1527 */
b556f8ad 1528void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
168b7173 1529 size_t len)
83c7d091 1530{
168b7173
SG
1531 int i, avail, new_len;
1532 unsigned char *ptr;
1533 struct sk_buff *skb;
168b7173 1534
8ef2d304
AG
1535 if (!ab)
1536 return;
1537
168b7173
SG
1538 BUG_ON(!ab->skb);
1539 skb = ab->skb;
1540 avail = skb_tailroom(skb);
1541 new_len = len<<1;
1542 if (new_len >= avail) {
1543 /* Round the buffer request up to the next multiple */
1544 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1545 avail = audit_expand(ab, new_len);
1546 if (!avail)
1547 return;
1548 }
83c7d091 1549
27a884dc 1550 ptr = skb_tail_pointer(skb);
b8dbc324
JP
1551 for (i = 0; i < len; i++)
1552 ptr = hex_byte_pack_upper(ptr, buf[i]);
168b7173
SG
1553 *ptr = 0;
1554 skb_put(skb, len << 1); /* new string is twice the old string */
83c7d091 1555}
1556
9c937dcc
AG
1557/*
1558 * Format a string of no more than slen characters into the audit buffer,
1559 * enclosed in quote marks.
1560 */
b556f8ad
EP
1561void audit_log_n_string(struct audit_buffer *ab, const char *string,
1562 size_t slen)
9c937dcc
AG
1563{
1564 int avail, new_len;
1565 unsigned char *ptr;
1566 struct sk_buff *skb;
1567
8ef2d304
AG
1568 if (!ab)
1569 return;
1570
9c937dcc
AG
1571 BUG_ON(!ab->skb);
1572 skb = ab->skb;
1573 avail = skb_tailroom(skb);
1574 new_len = slen + 3; /* enclosing quotes + null terminator */
1575 if (new_len > avail) {
1576 avail = audit_expand(ab, new_len);
1577 if (!avail)
1578 return;
1579 }
27a884dc 1580 ptr = skb_tail_pointer(skb);
9c937dcc
AG
1581 *ptr++ = '"';
1582 memcpy(ptr, string, slen);
1583 ptr += slen;
1584 *ptr++ = '"';
1585 *ptr = 0;
1586 skb_put(skb, slen + 2); /* don't include null terminator */
1587}
1588
de6bbd1d
EP
1589/**
1590 * audit_string_contains_control - does a string need to be logged in hex
f706d5d2
DJ
1591 * @string: string to be checked
1592 * @len: max length of the string to check
de6bbd1d 1593 */
9fcf836b 1594bool audit_string_contains_control(const char *string, size_t len)
de6bbd1d
EP
1595{
1596 const unsigned char *p;
b3897f56 1597 for (p = string; p < (const unsigned char *)string + len; p++) {
1d6c9649 1598 if (*p == '"' || *p < 0x21 || *p > 0x7e)
9fcf836b 1599 return true;
de6bbd1d 1600 }
9fcf836b 1601 return false;
de6bbd1d
EP
1602}
1603
b0dd25a8 1604/**
522ed776 1605 * audit_log_n_untrustedstring - log a string that may contain random characters
b0dd25a8 1606 * @ab: audit_buffer
f706d5d2 1607 * @len: length of string (not including trailing null)
b0dd25a8
RD
1608 * @string: string to be logged
1609 *
1610 * This code will escape a string that is passed to it if the string
1611 * contains a control character, unprintable character, double quote mark,
168b7173 1612 * or a space. Unescaped strings will start and end with a double quote mark.
b0dd25a8 1613 * Strings that are escaped are printed in hex (2 digits per char).
9c937dcc
AG
1614 *
1615 * The caller specifies the number of characters in the string to log, which may
1616 * or may not be the entire string.
b0dd25a8 1617 */
b556f8ad
EP
1618void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1619 size_t len)
83c7d091 1620{
de6bbd1d 1621 if (audit_string_contains_control(string, len))
b556f8ad 1622 audit_log_n_hex(ab, string, len);
de6bbd1d 1623 else
b556f8ad 1624 audit_log_n_string(ab, string, len);
83c7d091 1625}
1626
9c937dcc 1627/**
522ed776 1628 * audit_log_untrustedstring - log a string that may contain random characters
9c937dcc
AG
1629 * @ab: audit_buffer
1630 * @string: string to be logged
1631 *
522ed776 1632 * Same as audit_log_n_untrustedstring(), except that strlen is used to
9c937dcc
AG
1633 * determine string length.
1634 */
de6bbd1d 1635void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
9c937dcc 1636{
b556f8ad 1637 audit_log_n_untrustedstring(ab, string, strlen(string));
9c937dcc
AG
1638}
1639
168b7173 1640/* This is a helper-function to print the escaped d_path */
1da177e4 1641void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
66b3fad3 1642 const struct path *path)
1da177e4 1643{
44707fdf 1644 char *p, *pathname;
1da177e4 1645
8fc6115c 1646 if (prefix)
c158a35c 1647 audit_log_format(ab, "%s", prefix);
1da177e4 1648
168b7173 1649 /* We will allow 11 spaces for ' (deleted)' to be appended */
44707fdf
JB
1650 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1651 if (!pathname) {
def57543 1652 audit_log_string(ab, "<no_memory>");
168b7173 1653 return;
1da177e4 1654 }
cf28b486 1655 p = d_path(path, pathname, PATH_MAX+11);
168b7173
SG
1656 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1657 /* FIXME: can we save some information here? */
def57543 1658 audit_log_string(ab, "<too_long>");
5600b892 1659 } else
168b7173 1660 audit_log_untrustedstring(ab, p);
44707fdf 1661 kfree(pathname);
1da177e4
LT
1662}
1663
4d3fb709
EP
1664void audit_log_session_info(struct audit_buffer *ab)
1665{
4440e854 1666 unsigned int sessionid = audit_get_sessionid(current);
4d3fb709
EP
1667 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1668
b8f89caa 1669 audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
4d3fb709
EP
1670}
1671
9d960985
EP
1672void audit_log_key(struct audit_buffer *ab, char *key)
1673{
1674 audit_log_format(ab, " key=");
1675 if (key)
1676 audit_log_untrustedstring(ab, key);
1677 else
1678 audit_log_format(ab, "(null)");
1679}
1680
b24a30a7
EP
1681void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1682{
1683 int i;
1684
1685 audit_log_format(ab, " %s=", prefix);
1686 CAP_FOR_EACH_U32(i) {
1687 audit_log_format(ab, "%08x",
7d8b6c63 1688 cap->cap[CAP_LAST_U32 - i]);
b24a30a7
EP
1689 }
1690}
1691
691e6d59 1692static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
b24a30a7
EP
1693{
1694 kernel_cap_t *perm = &name->fcap.permitted;
1695 kernel_cap_t *inh = &name->fcap.inheritable;
1696 int log = 0;
1697
1698 if (!cap_isclear(*perm)) {
1699 audit_log_cap(ab, "cap_fp", perm);
1700 log = 1;
1701 }
1702 if (!cap_isclear(*inh)) {
1703 audit_log_cap(ab, "cap_fi", inh);
1704 log = 1;
1705 }
1706
1707 if (log)
1708 audit_log_format(ab, " cap_fe=%d cap_fver=%x",
1709 name->fcap.fE, name->fcap_ver);
1710}
1711
1712static inline int audit_copy_fcaps(struct audit_names *name,
1713 const struct dentry *dentry)
1714{
1715 struct cpu_vfs_cap_data caps;
1716 int rc;
1717
1718 if (!dentry)
1719 return 0;
1720
1721 rc = get_vfs_caps_from_disk(dentry, &caps);
1722 if (rc)
1723 return rc;
1724
1725 name->fcap.permitted = caps.permitted;
1726 name->fcap.inheritable = caps.inheritable;
1727 name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1728 name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
1729 VFS_CAP_REVISION_SHIFT;
1730
1731 return 0;
1732}
1733
1734/* Copy inode data into an audit_names. */
1735void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
d6335d77 1736 struct inode *inode)
b24a30a7
EP
1737{
1738 name->ino = inode->i_ino;
1739 name->dev = inode->i_sb->s_dev;
1740 name->mode = inode->i_mode;
1741 name->uid = inode->i_uid;
1742 name->gid = inode->i_gid;
1743 name->rdev = inode->i_rdev;
1744 security_inode_getsecid(inode, &name->osid);
1745 audit_copy_fcaps(name, dentry);
1746}
1747
1748/**
1749 * audit_log_name - produce AUDIT_PATH record from struct audit_names
1750 * @context: audit_context for the task
1751 * @n: audit_names structure with reportable details
1752 * @path: optional path to report instead of audit_names->name
1753 * @record_num: record number to report when handling a list of names
1754 * @call_panic: optional pointer to int that will be updated if secid fails
1755 */
1756void audit_log_name(struct audit_context *context, struct audit_names *n,
1757 struct path *path, int record_num, int *call_panic)
1758{
1759 struct audit_buffer *ab;
1760 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1761 if (!ab)
1762 return;
1763
1764 audit_log_format(ab, "item=%d", record_num);
1765
1766 if (path)
1767 audit_log_d_path(ab, " name=", path);
1768 else if (n->name) {
1769 switch (n->name_len) {
1770 case AUDIT_NAME_FULL:
1771 /* log the full path */
1772 audit_log_format(ab, " name=");
1773 audit_log_untrustedstring(ab, n->name->name);
1774 break;
1775 case 0:
1776 /* name was specified as a relative path and the
1777 * directory component is the cwd */
1778 audit_log_d_path(ab, " name=", &context->pwd);
1779 break;
1780 default:
1781 /* log the name's directory component */
1782 audit_log_format(ab, " name=");
1783 audit_log_n_untrustedstring(ab, n->name->name,
1784 n->name_len);
1785 }
1786 } else
1787 audit_log_format(ab, " name=(null)");
1788
425afcff 1789 if (n->ino != AUDIT_INO_UNSET)
b24a30a7
EP
1790 audit_log_format(ab, " inode=%lu"
1791 " dev=%02x:%02x mode=%#ho"
1792 " ouid=%u ogid=%u rdev=%02x:%02x",
1793 n->ino,
1794 MAJOR(n->dev),
1795 MINOR(n->dev),
1796 n->mode,
1797 from_kuid(&init_user_ns, n->uid),
1798 from_kgid(&init_user_ns, n->gid),
1799 MAJOR(n->rdev),
1800 MINOR(n->rdev));
b24a30a7
EP
1801 if (n->osid != 0) {
1802 char *ctx = NULL;
1803 u32 len;
1804 if (security_secid_to_secctx(
1805 n->osid, &ctx, &len)) {
1806 audit_log_format(ab, " osid=%u", n->osid);
1807 if (call_panic)
1808 *call_panic = 2;
1809 } else {
1810 audit_log_format(ab, " obj=%s", ctx);
1811 security_release_secctx(ctx, len);
1812 }
1813 }
1814
d3aea84a
JL
1815 /* log the audit_names record type */
1816 audit_log_format(ab, " nametype=");
1817 switch(n->type) {
1818 case AUDIT_TYPE_NORMAL:
1819 audit_log_format(ab, "NORMAL");
1820 break;
1821 case AUDIT_TYPE_PARENT:
1822 audit_log_format(ab, "PARENT");
1823 break;
1824 case AUDIT_TYPE_CHILD_DELETE:
1825 audit_log_format(ab, "DELETE");
1826 break;
1827 case AUDIT_TYPE_CHILD_CREATE:
1828 audit_log_format(ab, "CREATE");
1829 break;
1830 default:
1831 audit_log_format(ab, "UNKNOWN");
1832 break;
1833 }
1834
b24a30a7
EP
1835 audit_log_fcaps(ab, n);
1836 audit_log_end(ab);
1837}
1838
1839int audit_log_task_context(struct audit_buffer *ab)
1840{
1841 char *ctx = NULL;
1842 unsigned len;
1843 int error;
1844 u32 sid;
1845
1846 security_task_getsecid(current, &sid);
1847 if (!sid)
1848 return 0;
1849
1850 error = security_secid_to_secctx(sid, &ctx, &len);
1851 if (error) {
1852 if (error != -EINVAL)
1853 goto error_path;
1854 return 0;
1855 }
1856
1857 audit_log_format(ab, " subj=%s", ctx);
1858 security_release_secctx(ctx, len);
1859 return 0;
1860
1861error_path:
1862 audit_panic("error in audit_log_task_context");
1863 return error;
1864}
1865EXPORT_SYMBOL(audit_log_task_context);
1866
4766b199
DB
1867void audit_log_d_path_exe(struct audit_buffer *ab,
1868 struct mm_struct *mm)
1869{
5b282552
DB
1870 struct file *exe_file;
1871
1872 if (!mm)
1873 goto out_null;
4766b199 1874
5b282552
DB
1875 exe_file = get_mm_exe_file(mm);
1876 if (!exe_file)
1877 goto out_null;
1878
1879 audit_log_d_path(ab, " exe=", &exe_file->f_path);
1880 fput(exe_file);
1881 return;
1882out_null:
1883 audit_log_format(ab, " exe=(null)");
4766b199
DB
1884}
1885
3f5be2da
RGB
1886struct tty_struct *audit_get_tty(struct task_struct *tsk)
1887{
1888 struct tty_struct *tty = NULL;
1889 unsigned long flags;
1890
1891 spin_lock_irqsave(&tsk->sighand->siglock, flags);
1892 if (tsk->signal)
1893 tty = tty_kref_get(tsk->signal->tty);
1894 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1895 return tty;
1896}
1897
1898void audit_put_tty(struct tty_struct *tty)
1899{
1900 tty_kref_put(tty);
1901}
1902
b24a30a7
EP
1903void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
1904{
1905 const struct cred *cred;
9eab339b 1906 char comm[sizeof(tsk->comm)];
db0a6fb5 1907 struct tty_struct *tty;
b24a30a7
EP
1908
1909 if (!ab)
1910 return;
1911
1912 /* tsk == current */
1913 cred = current_cred();
db0a6fb5 1914 tty = audit_get_tty(tsk);
b24a30a7 1915 audit_log_format(ab,
c92cdeb4 1916 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
b24a30a7 1917 " euid=%u suid=%u fsuid=%u"
2f2ad101 1918 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
c92cdeb4 1919 task_ppid_nr(tsk),
f1dc4867 1920 task_pid_nr(tsk),
b24a30a7
EP
1921 from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
1922 from_kuid(&init_user_ns, cred->uid),
1923 from_kgid(&init_user_ns, cred->gid),
1924 from_kuid(&init_user_ns, cred->euid),
1925 from_kuid(&init_user_ns, cred->suid),
1926 from_kuid(&init_user_ns, cred->fsuid),
1927 from_kgid(&init_user_ns, cred->egid),
1928 from_kgid(&init_user_ns, cred->sgid),
1929 from_kgid(&init_user_ns, cred->fsgid),
db0a6fb5
RGB
1930 tty ? tty_name(tty) : "(none)",
1931 audit_get_sessionid(tsk));
1932 audit_put_tty(tty);
b24a30a7 1933 audit_log_format(ab, " comm=");
9eab339b 1934 audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
4766b199 1935 audit_log_d_path_exe(ab, tsk->mm);
b24a30a7
EP
1936 audit_log_task_context(ab);
1937}
1938EXPORT_SYMBOL(audit_log_task_info);
1939
a51d9eaa
KC
1940/**
1941 * audit_log_link_denied - report a link restriction denial
22011964 1942 * @operation: specific link operation
a51d9eaa
KC
1943 * @link: the path that triggered the restriction
1944 */
1945void audit_log_link_denied(const char *operation, struct path *link)
1946{
1947 struct audit_buffer *ab;
b24a30a7
EP
1948 struct audit_names *name;
1949
1950 name = kzalloc(sizeof(*name), GFP_NOFS);
1951 if (!name)
1952 return;
a51d9eaa 1953
b24a30a7 1954 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
a51d9eaa
KC
1955 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1956 AUDIT_ANOM_LINK);
d1c7d97a 1957 if (!ab)
b24a30a7
EP
1958 goto out;
1959 audit_log_format(ab, "op=%s", operation);
1960 audit_log_task_info(ab, current);
1961 audit_log_format(ab, " res=0");
a51d9eaa 1962 audit_log_end(ab);
b24a30a7
EP
1963
1964 /* Generate AUDIT_PATH record with object. */
1965 name->type = AUDIT_TYPE_NORMAL;
3b362157 1966 audit_copy_inode(name, link->dentry, d_backing_inode(link->dentry));
b24a30a7
EP
1967 audit_log_name(current->audit_context, name, link, 0, NULL);
1968out:
1969 kfree(name);
a51d9eaa
KC
1970}
1971
b0dd25a8
RD
1972/**
1973 * audit_log_end - end one audit record
1974 * @ab: the audit_buffer
1975 *
451f9216
RGB
1976 * netlink_unicast() cannot be called inside an irq context because it blocks
1977 * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed
1978 * on a queue and a tasklet is scheduled to remove them from the queue outside
1979 * the irq context. May be called in any context.
b0dd25a8 1980 */
b7d11258 1981void audit_log_end(struct audit_buffer *ab)
1da177e4 1982{
1da177e4
LT
1983 if (!ab)
1984 return;
1985 if (!audit_rate_check()) {
1986 audit_log_lost("rate limit exceeded");
1987 } else {
8d07a67c 1988 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
451f9216 1989
54e05edd 1990 nlh->nlmsg_len = ab->skb->len;
54dc77d9 1991 kauditd_send_multicast_skb(ab->skb, ab->gfp_mask);
451f9216
RGB
1992
1993 /*
1994 * The original kaudit unicast socket sends up messages with
1995 * nlmsg_len set to the payload length rather than the entire
1996 * message length. This breaks the standard set by netlink.
1997 * The existing auditd daemon assumes this breakage. Fixing
1998 * this would require co-ordinating a change in the established
1999 * protocol between the kaudit kernel subsystem and the auditd
2000 * userspace code.
2001 */
54e05edd 2002 nlh->nlmsg_len -= NLMSG_HDRLEN;
f3d357b0 2003
b7d11258 2004 if (audit_pid) {
b7d11258 2005 skb_queue_tail(&audit_skb_queue, ab->skb);
b7d11258 2006 wake_up_interruptible(&kauditd_wait);
f3d357b0 2007 } else {
038cbcf6 2008 audit_printk_skb(ab->skb);
b7d11258 2009 }
f3d357b0 2010 ab->skb = NULL;
1da177e4 2011 }
16e1904e 2012 audit_buffer_free(ab);
1da177e4
LT
2013}
2014
b0dd25a8
RD
2015/**
2016 * audit_log - Log an audit record
2017 * @ctx: audit context
2018 * @gfp_mask: type of allocation
2019 * @type: audit message type
2020 * @fmt: format string to use
2021 * @...: variable parameters matching the format string
2022 *
2023 * This is a convenience function that calls audit_log_start,
2024 * audit_log_vformat, and audit_log_end. It may be called
2025 * in any context.
2026 */
5600b892 2027void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
9ad9ad38 2028 const char *fmt, ...)
1da177e4
LT
2029{
2030 struct audit_buffer *ab;
2031 va_list args;
2032
9ad9ad38 2033 ab = audit_log_start(ctx, gfp_mask, type);
1da177e4
LT
2034 if (ab) {
2035 va_start(args, fmt);
2036 audit_log_vformat(ab, fmt, args);
2037 va_end(args);
2038 audit_log_end(ab);
2039 }
2040}
bf45da97 2041
131ad62d
MDF
2042#ifdef CONFIG_SECURITY
2043/**
2044 * audit_log_secctx - Converts and logs SELinux context
2045 * @ab: audit_buffer
2046 * @secid: security number
2047 *
2048 * This is a helper function that calls security_secid_to_secctx to convert
2049 * secid to secctx and then adds the (converted) SELinux context to the audit
2050 * log by calling audit_log_format, thus also preventing leak of internal secid
2051 * to userspace. If secid cannot be converted audit_panic is called.
2052 */
2053void audit_log_secctx(struct audit_buffer *ab, u32 secid)
2054{
2055 u32 len;
2056 char *secctx;
2057
2058 if (security_secid_to_secctx(secid, &secctx, &len)) {
2059 audit_panic("Cannot convert secid to context");
2060 } else {
2061 audit_log_format(ab, " obj=%s", secctx);
2062 security_release_secctx(secctx, len);
2063 }
2064}
2065EXPORT_SYMBOL(audit_log_secctx);
2066#endif
2067
bf45da97 2068EXPORT_SYMBOL(audit_log_start);
2069EXPORT_SYMBOL(audit_log_end);
2070EXPORT_SYMBOL(audit_log_format);
2071EXPORT_SYMBOL(audit_log);