blob: 9442c3533ba9f8be398333d8ee7b74882b339ae0 [file] [log] [blame]
85c87212005-04-29 16:23:29 +01001/* audit.c -- Auditing support
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
3 * System-call specific features have moved to auditsc.c
4 *
Steve Grubb6a01b072007-01-19 14:39:55 -05005 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * 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 *
Ahmed S. Darwishd7a96f32008-03-01 22:01:11 +020024 * Goals: 1) Integrate fully with Security Modules.
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 * 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 *
85c87212005-04-29 16:23:29 +010041 * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 */
43
44#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#include <asm/types.h>
Alan Cox715b49e2006-01-18 17:44:07 -080046#include <asm/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/mm.h>
48#include <linux/module.h>
David Woodhouseb7d11252005-05-19 10:56:58 +010049#include <linux/err.h>
50#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
52#include <linux/audit.h>
53
54#include <net/sock.h>
Amy Griffis93315ed2006-02-07 12:05:27 -050055#include <net/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#include <linux/skbuff.h>
57#include <linux/netlink.h>
Amy Griffisf368c07d2006-04-07 16:55:56 -040058#include <linux/inotify.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080059#include <linux/freezer.h>
Miloslav Trmac522ed772007-07-15 23:40:56 -070060#include <linux/tty.h>
Darrel Goeddel3dc7e312006-03-10 18:14:06 -060061
62#include "audit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Eric Parisa3f07112008-11-05 12:47:09 -050064/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 * (Initialization happens after skb_init is called.) */
Eric Parisa3f07112008-11-05 12:47:09 -050066#define AUDIT_DISABLED -1
67#define AUDIT_UNINITIALIZED 0
68#define AUDIT_INITIALIZED 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070069static int audit_initialized;
70
Eric Paris1a6b9f22008-01-07 17:09:31 -050071#define AUDIT_OFF 0
72#define AUDIT_ON 1
73#define AUDIT_LOCKED 2
Linus Torvalds1da177e2005-04-16 15:20:36 -070074int audit_enabled;
Eric Parisb593d382008-01-08 17:38:31 -050075int audit_ever_enabled;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77/* Default state when kernel boots without any parameters. */
78static int audit_default;
79
80/* If auditing cannot proceed, audit_failure selects what happens. */
81static int audit_failure = AUDIT_FAIL_PRINTK;
82
Pavel Emelyanov75c03712008-03-20 15:39:41 -070083/*
84 * If audit records are to be written to the netlink socket, audit_pid
85 * contains the pid of the auditd process and audit_nlk_pid contains
86 * the pid to use to send netlink messages to that process.
87 */
Steve Grubbc2f0c7c2005-05-06 12:38:39 +010088int audit_pid;
Pavel Emelyanov75c03712008-03-20 15:39:41 -070089static int audit_nlk_pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Randy Dunlapb0dd25a2005-09-13 12:47:11 -070091/* If audit_rate_limit is non-zero, limit the rate of sending audit records
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 * to that number per second. This prevents DoS attacks, but results in
93 * audit records being dropped. */
94static int audit_rate_limit;
95
96/* Number of outstanding audit_buffers allowed. */
97static int audit_backlog_limit = 64;
David Woodhouseac4cec42005-07-02 14:08:48 +010098static int audit_backlog_wait_time = 60 * HZ;
99static int audit_backlog_wait_overflow = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100101/* The identity of the user shutting down the audit system. */
102uid_t audit_sig_uid = -1;
103pid_t audit_sig_pid = -1;
Al Viroe1396062006-05-25 10:19:47 -0400104u32 audit_sig_sid = 0;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106/* Records can be lost in several ways:
107 0) [suppressed in audit_alloc]
108 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
109 2) out of memory in audit_log_move [alloc_skb]
110 3) suppressed due to audit_rate_limit
111 4) suppressed due to audit_backlog_limit
112*/
113static atomic_t audit_lost = ATOMIC_INIT(0);
114
115/* The netlink socket. */
116static struct sock *audit_sock;
117
Amy Griffisf368c07d2006-04-07 16:55:56 -0400118/* Inotify handle. */
119struct inotify_handle *audit_ih;
120
121/* Hash for inode-based rules */
122struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
123
David Woodhouseb7d11252005-05-19 10:56:58 +0100124/* The audit_freelist is a list of pre-allocated audit buffers (if more
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
126 * being placed on the freelist). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127static DEFINE_SPINLOCK(audit_freelist_lock);
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700128static int audit_freelist_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129static LIST_HEAD(audit_freelist);
130
David Woodhouseb7d11252005-05-19 10:56:58 +0100131static struct sk_buff_head audit_skb_queue;
Eric Parisf3d357b2008-04-18 10:02:28 -0400132/* queue of skbs to send to auditd when/if it comes back */
133static struct sk_buff_head audit_skb_hold_queue;
David Woodhouseb7d11252005-05-19 10:56:58 +0100134static struct task_struct *kauditd_task;
135static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100136static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
Amy Griffisf368c07d2006-04-07 16:55:56 -0400138/* Serialize requests from userspace. */
139static DEFINE_MUTEX(audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
141/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
142 * audit records. Since printk uses a 1024 byte buffer, this buffer
143 * should be at least that large. */
144#define AUDIT_BUFSIZ 1024
145
146/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
147 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
148#define AUDIT_MAXFREE (2*NR_CPUS)
149
150/* The audit_buffer is used when formatting an audit record. The caller
151 * locks briefly to get the record off the freelist or to allocate the
152 * buffer, and locks briefly to send the buffer to the netlink layer or
153 * to place it on a transmit queue. Multiple audit_buffers can be in
154 * use simultaneously. */
155struct audit_buffer {
156 struct list_head list;
Chris Wright8fc61152005-05-06 15:54:17 +0100157 struct sk_buff *skb; /* formatted skb ready to send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 struct audit_context *ctx; /* NULL or associated context */
Al Viro9796fdd2005-10-21 03:22:03 -0400159 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160};
161
Eric Parisf09ac9d2008-04-18 10:11:04 -0400162struct audit_reply {
163 int pid;
164 struct sk_buff *skb;
165};
166
Steve Grubbc0404992005-05-13 18:17:42 +0100167static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
168{
Eric Paris50397bd2008-01-07 18:14:19 -0500169 if (ab) {
170 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
171 nlh->nlmsg_pid = pid;
172 }
Steve Grubbc0404992005-05-13 18:17:42 +0100173}
174
Dustin Kirkland8c8570f2005-11-03 17:15:16 +0000175void audit_panic(const char *message)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176{
177 switch (audit_failure)
178 {
179 case AUDIT_FAIL_SILENT:
180 break;
181 case AUDIT_FAIL_PRINTK:
Eric Paris320f1b12008-01-23 22:55:05 -0500182 if (printk_ratelimit())
183 printk(KERN_ERR "audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 break;
185 case AUDIT_FAIL_PANIC:
Eric Parisb29ee872008-02-21 15:53:05 -0500186 /* test audit_pid since printk is always losey, why bother? */
187 if (audit_pid)
188 panic("audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 break;
190 }
191}
192
193static inline int audit_rate_check(void)
194{
195 static unsigned long last_check = 0;
196 static int messages = 0;
197 static DEFINE_SPINLOCK(lock);
198 unsigned long flags;
199 unsigned long now;
200 unsigned long elapsed;
201 int retval = 0;
202
203 if (!audit_rate_limit) return 1;
204
205 spin_lock_irqsave(&lock, flags);
206 if (++messages < audit_rate_limit) {
207 retval = 1;
208 } else {
209 now = jiffies;
210 elapsed = now - last_check;
211 if (elapsed > HZ) {
212 last_check = now;
213 messages = 0;
214 retval = 1;
215 }
216 }
217 spin_unlock_irqrestore(&lock, flags);
218
219 return retval;
220}
221
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700222/**
223 * audit_log_lost - conditionally log lost audit message event
224 * @message: the message stating reason for lost audit message
225 *
226 * Emit at least 1 message per second, even if audit_rate_check is
227 * throttling.
228 * Always increment the lost messages counter.
229*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230void audit_log_lost(const char *message)
231{
232 static unsigned long last_msg = 0;
233 static DEFINE_SPINLOCK(lock);
234 unsigned long flags;
235 unsigned long now;
236 int print;
237
238 atomic_inc(&audit_lost);
239
240 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
241
242 if (!print) {
243 spin_lock_irqsave(&lock, flags);
244 now = jiffies;
245 if (now - last_msg > HZ) {
246 print = 1;
247 last_msg = now;
248 }
249 spin_unlock_irqrestore(&lock, flags);
250 }
251
252 if (print) {
Eric Paris320f1b12008-01-23 22:55:05 -0500253 if (printk_ratelimit())
254 printk(KERN_WARNING
255 "audit: audit_lost=%d audit_rate_limit=%d "
256 "audit_backlog_limit=%d\n",
257 atomic_read(&audit_lost),
258 audit_rate_limit,
259 audit_backlog_limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 audit_panic(message);
261 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262}
263
Eric Paris1a6b9f22008-01-07 17:09:31 -0500264static int audit_log_config_change(char *function_name, int new, int old,
Eric Paris25323862008-04-18 10:09:25 -0400265 uid_t loginuid, u32 sessionid, u32 sid,
266 int allow_changes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500268 struct audit_buffer *ab;
269 int rc = 0;
Steve Grubb6a01b072007-01-19 14:39:55 -0500270
Eric Paris1a6b9f22008-01-07 17:09:31 -0500271 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
Eric Paris25323862008-04-18 10:09:25 -0400272 audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
273 old, loginuid, sessionid);
Steve Grubbce29b682006-04-01 18:29:34 -0500274 if (sid) {
275 char *ctx = NULL;
276 u32 len;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500277
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200278 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500279 if (rc) {
280 audit_log_format(ab, " sid=%u", sid);
281 allow_changes = 0; /* Something weird, deny request */
282 } else {
283 audit_log_format(ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200284 security_release_secctx(ctx, len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500285 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500286 }
Eric Paris1a6b9f22008-01-07 17:09:31 -0500287 audit_log_format(ab, " res=%d", allow_changes);
288 audit_log_end(ab);
289 return rc;
290}
291
292static int audit_do_config_change(char *function_name, int *to_change,
Eric Paris25323862008-04-18 10:09:25 -0400293 int new, uid_t loginuid, u32 sessionid,
294 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500295{
296 int allow_changes, rc = 0, old = *to_change;
297
298 /* check if we are locked */
299 if (audit_enabled == AUDIT_LOCKED)
300 allow_changes = 0;
301 else
302 allow_changes = 1;
303
304 if (audit_enabled != AUDIT_OFF) {
Eric Paris25323862008-04-18 10:09:25 -0400305 rc = audit_log_config_change(function_name, new, old, loginuid,
306 sessionid, sid, allow_changes);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500307 if (rc)
308 allow_changes = 0;
309 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500310
311 /* If we are allowed, make the change */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500312 if (allow_changes == 1)
313 *to_change = new;
Steve Grubb6a01b072007-01-19 14:39:55 -0500314 /* Not allowed, update reason */
315 else if (rc == 0)
316 rc = -EPERM;
317 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318}
319
Eric Paris25323862008-04-18 10:09:25 -0400320static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
321 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500322{
323 return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400324 limit, loginuid, sessionid, sid);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500325}
326
Eric Paris25323862008-04-18 10:09:25 -0400327static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
328 u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500330 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400331 limit, loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332}
333
Eric Paris25323862008-04-18 10:09:25 -0400334static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335{
Eric Parisb593d382008-01-08 17:38:31 -0500336 int rc;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500337 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500339
Eric Parisb593d382008-01-08 17:38:31 -0500340 rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
Eric Paris25323862008-04-18 10:09:25 -0400341 loginuid, sessionid, sid);
Eric Parisb593d382008-01-08 17:38:31 -0500342
343 if (!rc)
344 audit_ever_enabled |= !!state;
345
346 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347}
348
Eric Paris25323862008-04-18 10:09:25 -0400349static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 if (state != AUDIT_FAIL_SILENT
352 && state != AUDIT_FAIL_PRINTK
353 && state != AUDIT_FAIL_PANIC)
354 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500355
Eric Paris1a6b9f22008-01-07 17:09:31 -0500356 return audit_do_config_change("audit_failure", &audit_failure, state,
Eric Paris25323862008-04-18 10:09:25 -0400357 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358}
359
Eric Parisf3d357b2008-04-18 10:02:28 -0400360/*
361 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
362 * already have been sent via prink/syslog and so if these messages are dropped
363 * it is not a huge concern since we already passed the audit_log_lost()
364 * notification and stuff. This is just nice to get audit messages during
365 * boot before auditd is running or messages generated while auditd is stopped.
366 * This only holds messages is audit_default is set, aka booting with audit=1
367 * or building your kernel that way.
368 */
369static void audit_hold_skb(struct sk_buff *skb)
370{
371 if (audit_default &&
372 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
373 skb_queue_tail(&audit_skb_hold_queue, skb);
374 else
375 kfree_skb(skb);
376}
377
378static void kauditd_send_skb(struct sk_buff *skb)
379{
380 int err;
381 /* take a reference in case we can't send it and we want to hold it */
382 skb_get(skb);
383 err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
384 if (err < 0) {
385 BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */
386 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
387 audit_log_lost("auditd dissapeared\n");
388 audit_pid = 0;
389 /* we might get lucky and get this in the next auditd */
390 audit_hold_skb(skb);
391 } else
392 /* drop the extra reference if sent ok */
393 kfree_skb(skb);
394}
395
Adrian Bunk97a41e22006-01-08 01:02:17 -0800396static int kauditd_thread(void *dummy)
David Woodhouseb7d11252005-05-19 10:56:58 +0100397{
398 struct sk_buff *skb;
399
Rafael J. Wysocki83144182007-07-17 04:03:35 -0700400 set_freezable();
Andrew Morton4899b8b2006-10-06 00:43:48 -0700401 while (!kthread_should_stop()) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400402 /*
403 * if auditd just started drain the queue of messages already
404 * sent to syslog/printk. remember loss here is ok. we already
405 * called audit_log_lost() if it didn't go out normally. so the
406 * race between the skb_dequeue and the next check for audit_pid
407 * doesn't matter.
408 *
409 * if you ever find kauditd to be too slow we can get a perf win
410 * by doing our own locking and keeping better track if there
411 * are messages in this queue. I don't see the need now, but
412 * in 5 years when I want to play with this again I'll see this
413 * note and still have no friggin idea what i'm thinking today.
414 */
415 if (audit_default && audit_pid) {
416 skb = skb_dequeue(&audit_skb_hold_queue);
417 if (unlikely(skb)) {
418 while (skb && audit_pid) {
419 kauditd_send_skb(skb);
420 skb = skb_dequeue(&audit_skb_hold_queue);
421 }
422 }
423 }
424
David Woodhouseb7d11252005-05-19 10:56:58 +0100425 skb = skb_dequeue(&audit_skb_queue);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100426 wake_up(&audit_backlog_wait);
David Woodhouseb7d11252005-05-19 10:56:58 +0100427 if (skb) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400428 if (audit_pid)
429 kauditd_send_skb(skb);
430 else {
Eric Paris320f1b12008-01-23 22:55:05 -0500431 if (printk_ratelimit())
Eric Parisf3d357b2008-04-18 10:02:28 -0400432 printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0));
Eric Paris320f1b12008-01-23 22:55:05 -0500433 else
434 audit_log_lost("printk limit exceeded\n");
Eric Parisf3d357b2008-04-18 10:02:28 -0400435
436 audit_hold_skb(skb);
David Woodhouseb7d11252005-05-19 10:56:58 +0100437 }
438 } else {
439 DECLARE_WAITQUEUE(wait, current);
440 set_current_state(TASK_INTERRUPTIBLE);
441 add_wait_queue(&kauditd_wait, &wait);
442
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800443 if (!skb_queue_len(&audit_skb_queue)) {
444 try_to_freeze();
David Woodhouseb7d11252005-05-19 10:56:58 +0100445 schedule();
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800446 }
David Woodhouseb7d11252005-05-19 10:56:58 +0100447
448 __set_current_state(TASK_RUNNING);
449 remove_wait_queue(&kauditd_wait, &wait);
450 }
451 }
Andrew Morton4899b8b2006-10-06 00:43:48 -0700452 return 0;
David Woodhouseb7d11252005-05-19 10:56:58 +0100453}
454
Eric Paris25323862008-04-18 10:09:25 -0400455static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
Miloslav Trmac522ed772007-07-15 23:40:56 -0700456{
457 struct task_struct *tsk;
458 int err;
459
460 read_lock(&tasklist_lock);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700461 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700462 err = -ESRCH;
463 if (!tsk)
464 goto out;
465 err = 0;
466
467 spin_lock_irq(&tsk->sighand->siglock);
468 if (!tsk->signal->audit_tty)
469 err = -EPERM;
470 spin_unlock_irq(&tsk->sighand->siglock);
471 if (err)
472 goto out;
473
Eric Paris25323862008-04-18 10:09:25 -0400474 tty_audit_push_task(tsk, loginuid, sessionid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700475out:
476 read_unlock(&tasklist_lock);
477 return err;
478}
479
Al Viro9044e6b2006-05-22 01:09:24 -0400480int audit_send_list(void *_dest)
481{
482 struct audit_netlink_list *dest = _dest;
483 int pid = dest->pid;
484 struct sk_buff *skb;
485
486 /* wait for parent to finish and send an ACK */
Amy Griffisf368c07d2006-04-07 16:55:56 -0400487 mutex_lock(&audit_cmd_mutex);
488 mutex_unlock(&audit_cmd_mutex);
Al Viro9044e6b2006-05-22 01:09:24 -0400489
490 while ((skb = __skb_dequeue(&dest->q)) != NULL)
491 netlink_unicast(audit_sock, skb, pid, 0);
492
493 kfree(dest);
494
495 return 0;
496}
497
Al Viro74c3cbe2007-07-22 08:04:18 -0400498#ifdef CONFIG_AUDIT_TREE
499static int prune_tree_thread(void *unused)
500{
501 mutex_lock(&audit_cmd_mutex);
502 audit_prune_trees();
503 mutex_unlock(&audit_cmd_mutex);
504 return 0;
505}
506
507void audit_schedule_prune(void)
508{
509 kthread_run(prune_tree_thread, NULL, "audit_prune_tree");
510}
511#endif
512
Al Viro9044e6b2006-05-22 01:09:24 -0400513struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
514 int multi, void *payload, int size)
515{
516 struct sk_buff *skb;
517 struct nlmsghdr *nlh;
518 int len = NLMSG_SPACE(size);
519 void *data;
520 int flags = multi ? NLM_F_MULTI : 0;
521 int t = done ? NLMSG_DONE : type;
522
523 skb = alloc_skb(len, GFP_KERNEL);
524 if (!skb)
525 return NULL;
526
527 nlh = NLMSG_PUT(skb, pid, seq, t, size);
528 nlh->nlmsg_flags = flags;
529 data = NLMSG_DATA(nlh);
530 memcpy(data, payload, size);
531 return skb;
532
533nlmsg_failure: /* Used by NLMSG_PUT */
534 if (skb)
535 kfree_skb(skb);
536 return NULL;
537}
538
Eric Parisf09ac9d2008-04-18 10:11:04 -0400539static int audit_send_reply_thread(void *arg)
540{
541 struct audit_reply *reply = (struct audit_reply *)arg;
542
543 mutex_lock(&audit_cmd_mutex);
544 mutex_unlock(&audit_cmd_mutex);
545
546 /* Ignore failure. It'll only happen if the sender goes away,
547 because our timeout is set to infinite. */
548 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
549 kfree(reply);
550 return 0;
551}
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700552/**
553 * audit_send_reply - send an audit reply message via netlink
554 * @pid: process id to send reply to
555 * @seq: sequence number
556 * @type: audit message type
557 * @done: done (last) flag
558 * @multi: multi-part message flag
559 * @payload: payload data
560 * @size: payload size
561 *
562 * Allocates an skb, builds the netlink message, and sends it to the pid.
563 * No failure notifications.
564 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565void audit_send_reply(int pid, int seq, int type, int done, int multi,
566 void *payload, int size)
567{
Eric Parisf09ac9d2008-04-18 10:11:04 -0400568 struct sk_buff *skb;
569 struct task_struct *tsk;
570 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
571 GFP_KERNEL);
572
573 if (!reply)
574 return;
575
Al Viro9044e6b2006-05-22 01:09:24 -0400576 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 if (!skb)
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700578 goto out;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400579
580 reply->pid = pid;
581 reply->skb = skb;
582
583 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700584 if (!IS_ERR(tsk))
585 return;
586 kfree_skb(skb);
587out:
588 kfree(reply);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589}
590
591/*
592 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
593 * control messages.
594 */
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700595static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596{
597 int err = 0;
598
599 switch (msg_type) {
600 case AUDIT_GET:
601 case AUDIT_LIST:
Amy Griffis93315ed2006-02-07 12:05:27 -0500602 case AUDIT_LIST_RULES:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 case AUDIT_SET:
604 case AUDIT_ADD:
Amy Griffis93315ed2006-02-07 12:05:27 -0500605 case AUDIT_ADD_RULE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500607 case AUDIT_DEL_RULE:
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100608 case AUDIT_SIGNAL_INFO:
Miloslav Trmac522ed772007-07-15 23:40:56 -0700609 case AUDIT_TTY_GET:
610 case AUDIT_TTY_SET:
Al Viro74c3cbe2007-07-22 08:04:18 -0400611 case AUDIT_TRIM:
612 case AUDIT_MAKE_EQUIV:
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700613 if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 err = -EPERM;
615 break;
Steve Grubb05474102005-05-21 00:18:37 +0100616 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700617 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
618 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700619 if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 err = -EPERM;
621 break;
622 default: /* bad msg */
623 err = -EINVAL;
624 }
625
626 return err;
627}
628
Eric Paris50397bd2008-01-07 18:14:19 -0500629static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
Eric Paris25323862008-04-18 10:09:25 -0400630 u32 pid, u32 uid, uid_t auid, u32 ses,
631 u32 sid)
Eric Paris50397bd2008-01-07 18:14:19 -0500632{
633 int rc = 0;
634 char *ctx = NULL;
635 u32 len;
636
637 if (!audit_enabled) {
638 *ab = NULL;
639 return rc;
640 }
641
642 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
Eric Paris25323862008-04-18 10:09:25 -0400643 audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u",
644 pid, uid, auid, ses);
Eric Paris50397bd2008-01-07 18:14:19 -0500645 if (sid) {
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200646 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris50397bd2008-01-07 18:14:19 -0500647 if (rc)
648 audit_log_format(*ab, " ssid=%u", sid);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200649 else {
Eric Paris50397bd2008-01-07 18:14:19 -0500650 audit_log_format(*ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200651 security_release_secctx(ctx, len);
652 }
Eric Paris50397bd2008-01-07 18:14:19 -0500653 }
654
655 return rc;
656}
657
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
659{
Steve Grubbe7c34972006-04-03 09:08:13 -0400660 u32 uid, pid, seq, sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 void *data;
662 struct audit_status *status_get, status_set;
663 int err;
Steve Grubbc0404992005-05-13 18:17:42 +0100664 struct audit_buffer *ab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 u16 msg_type = nlh->nlmsg_type;
Serge Hallync94c2572005-04-29 16:27:17 +0100666 uid_t loginuid; /* loginuid of sender */
Eric Paris25323862008-04-18 10:09:25 -0400667 u32 sessionid;
Al Viroe1396062006-05-25 10:19:47 -0400668 struct audit_sig_info *sig_data;
Eric Paris50397bd2008-01-07 18:14:19 -0500669 char *ctx = NULL;
Al Viroe1396062006-05-25 10:19:47 -0400670 u32 len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700672 err = audit_netlink_ok(skb, msg_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 if (err)
674 return err;
675
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700676 /* As soon as there's any sign of userspace auditd,
677 * start kauditd to talk to it */
David Woodhouseb7d11252005-05-19 10:56:58 +0100678 if (!kauditd_task)
679 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
680 if (IS_ERR(kauditd_task)) {
681 err = PTR_ERR(kauditd_task);
682 kauditd_task = NULL;
683 return err;
684 }
685
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 pid = NETLINK_CREDS(skb)->pid;
687 uid = NETLINK_CREDS(skb)->uid;
Serge Hallync94c2572005-04-29 16:27:17 +0100688 loginuid = NETLINK_CB(skb).loginuid;
Eric Paris25323862008-04-18 10:09:25 -0400689 sessionid = NETLINK_CB(skb).sessionid;
Steve Grubbe7c34972006-04-03 09:08:13 -0400690 sid = NETLINK_CB(skb).sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 seq = nlh->nlmsg_seq;
692 data = NLMSG_DATA(nlh);
693
694 switch (msg_type) {
695 case AUDIT_GET:
696 status_set.enabled = audit_enabled;
697 status_set.failure = audit_failure;
698 status_set.pid = audit_pid;
699 status_set.rate_limit = audit_rate_limit;
700 status_set.backlog_limit = audit_backlog_limit;
701 status_set.lost = atomic_read(&audit_lost);
David Woodhouseb7d11252005-05-19 10:56:58 +0100702 status_set.backlog = skb_queue_len(&audit_skb_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
704 &status_set, sizeof(status_set));
705 break;
706 case AUDIT_SET:
707 if (nlh->nlmsg_len < sizeof(struct audit_status))
708 return -EINVAL;
709 status_get = (struct audit_status *)data;
710 if (status_get->mask & AUDIT_STATUS_ENABLED) {
Steve Grubbce29b682006-04-01 18:29:34 -0500711 err = audit_set_enabled(status_get->enabled,
Eric Paris25323862008-04-18 10:09:25 -0400712 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800713 if (err < 0)
714 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 }
716 if (status_get->mask & AUDIT_STATUS_FAILURE) {
Steve Grubbce29b682006-04-01 18:29:34 -0500717 err = audit_set_failure(status_get->failure,
Eric Paris25323862008-04-18 10:09:25 -0400718 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800719 if (err < 0)
720 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 }
722 if (status_get->mask & AUDIT_STATUS_PID) {
Eric Paris1a6b9f22008-01-07 17:09:31 -0500723 int new_pid = status_get->pid;
724
725 if (audit_enabled != AUDIT_OFF)
726 audit_log_config_change("audit_pid", new_pid,
727 audit_pid, loginuid,
Eric Paris25323862008-04-18 10:09:25 -0400728 sessionid, sid, 1);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500729
730 audit_pid = new_pid;
Pavel Emelyanov75c03712008-03-20 15:39:41 -0700731 audit_nlk_pid = NETLINK_CB(skb).pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 }
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800733 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500734 err = audit_set_rate_limit(status_get->rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400735 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800736 if (err < 0)
737 return err;
738 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500740 err = audit_set_backlog_limit(status_get->backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400741 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 break;
Steve Grubb05474102005-05-21 00:18:37 +0100743 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700744 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
745 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
David Woodhouse4a4cd632005-06-22 14:56:47 +0100746 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
747 return 0;
David Woodhouse0f45aa12005-06-19 19:35:50 +0100748
Peng Haitaod8de7242008-05-20 09:13:02 +0800749 err = audit_filter_user(&NETLINK_CB(skb));
David Woodhouse4a4cd632005-06-22 14:56:47 +0100750 if (err == 1) {
751 err = 0;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700752 if (msg_type == AUDIT_USER_TTY) {
Eric Paris25323862008-04-18 10:09:25 -0400753 err = audit_prepare_user_tty(pid, loginuid,
754 sessionid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700755 if (err)
756 break;
757 }
Eric Paris50397bd2008-01-07 18:14:19 -0500758 audit_log_common_recv_msg(&ab, msg_type, pid, uid,
Eric Paris25323862008-04-18 10:09:25 -0400759 loginuid, sessionid, sid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700760
Eric Paris50397bd2008-01-07 18:14:19 -0500761 if (msg_type != AUDIT_USER_TTY)
762 audit_log_format(ab, " msg='%.1024s'",
763 (char *)data);
764 else {
765 int size;
766
767 audit_log_format(ab, " msg=");
768 size = nlmsg_len(nlh);
Miloslav Trmac55ad2f82009-03-19 09:52:47 -0400769 if (size > 0 &&
770 ((unsigned char *)data)[size - 1] == '\0')
771 size--;
Eric Parisb556f8a2008-04-18 10:12:59 -0400772 audit_log_n_untrustedstring(ab, data, size);
David Woodhouse4a4cd632005-06-22 14:56:47 +0100773 }
Eric Paris50397bd2008-01-07 18:14:19 -0500774 audit_set_pid(ab, pid);
775 audit_log_end(ab);
David Woodhouse0f45aa12005-06-19 19:35:50 +0100776 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 break;
778 case AUDIT_ADD:
779 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500780 if (nlmsg_len(nlh) < sizeof(struct audit_rule))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500782 if (audit_enabled == AUDIT_LOCKED) {
Eric Paris50397bd2008-01-07 18:14:19 -0500783 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400784 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500785
786 audit_log_format(ab, " audit_enabled=%d res=0",
787 audit_enabled);
788 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -0500789 return -EPERM;
790 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 /* fallthrough */
792 case AUDIT_LIST:
Peng Haitao13d5ef92008-05-16 10:15:04 +0800793 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
Amy Griffis93315ed2006-02-07 12:05:27 -0500794 uid, seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400795 loginuid, sessionid, sid);
Amy Griffis93315ed2006-02-07 12:05:27 -0500796 break;
797 case AUDIT_ADD_RULE:
798 case AUDIT_DEL_RULE:
799 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
800 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500801 if (audit_enabled == AUDIT_LOCKED) {
Eric Paris50397bd2008-01-07 18:14:19 -0500802 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400803 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500804
805 audit_log_format(ab, " audit_enabled=%d res=0",
806 audit_enabled);
807 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -0500808 return -EPERM;
809 }
Amy Griffis93315ed2006-02-07 12:05:27 -0500810 /* fallthrough */
811 case AUDIT_LIST_RULES:
Peng Haitao13d5ef92008-05-16 10:15:04 +0800812 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
Amy Griffis93315ed2006-02-07 12:05:27 -0500813 uid, seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400814 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 break;
Al Viro74c3cbe2007-07-22 08:04:18 -0400816 case AUDIT_TRIM:
817 audit_trim_trees();
Eric Paris50397bd2008-01-07 18:14:19 -0500818
819 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400820 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500821
Al Viro74c3cbe2007-07-22 08:04:18 -0400822 audit_log_format(ab, " op=trim res=1");
823 audit_log_end(ab);
824 break;
825 case AUDIT_MAKE_EQUIV: {
826 void *bufp = data;
827 u32 sizes[2];
Harvey Harrison7719e432008-04-27 02:39:56 -0700828 size_t msglen = nlmsg_len(nlh);
Al Viro74c3cbe2007-07-22 08:04:18 -0400829 char *old, *new;
830
831 err = -EINVAL;
Harvey Harrison7719e432008-04-27 02:39:56 -0700832 if (msglen < 2 * sizeof(u32))
Al Viro74c3cbe2007-07-22 08:04:18 -0400833 break;
834 memcpy(sizes, bufp, 2 * sizeof(u32));
835 bufp += 2 * sizeof(u32);
Harvey Harrison7719e432008-04-27 02:39:56 -0700836 msglen -= 2 * sizeof(u32);
837 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400838 if (IS_ERR(old)) {
839 err = PTR_ERR(old);
840 break;
841 }
Harvey Harrison7719e432008-04-27 02:39:56 -0700842 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400843 if (IS_ERR(new)) {
844 err = PTR_ERR(new);
845 kfree(old);
846 break;
847 }
848 /* OK, here comes... */
849 err = audit_tag_tree(old, new);
850
Eric Paris50397bd2008-01-07 18:14:19 -0500851 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400852 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500853
Al Viro74c3cbe2007-07-22 08:04:18 -0400854 audit_log_format(ab, " op=make_equiv old=");
855 audit_log_untrustedstring(ab, old);
856 audit_log_format(ab, " new=");
857 audit_log_untrustedstring(ab, new);
858 audit_log_format(ab, " res=%d", !err);
859 audit_log_end(ab);
860 kfree(old);
861 kfree(new);
862 break;
863 }
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100864 case AUDIT_SIGNAL_INFO:
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200865 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
Al Viroe1396062006-05-25 10:19:47 -0400866 if (err)
867 return err;
868 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
869 if (!sig_data) {
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200870 security_release_secctx(ctx, len);
Al Viroe1396062006-05-25 10:19:47 -0400871 return -ENOMEM;
872 }
873 sig_data->uid = audit_sig_uid;
874 sig_data->pid = audit_sig_pid;
875 memcpy(sig_data->ctx, ctx, len);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200876 security_release_secctx(ctx, len);
Daniel Walker5600b892007-10-18 03:06:10 -0700877 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
Al Viroe1396062006-05-25 10:19:47 -0400878 0, 0, sig_data, sizeof(*sig_data) + len);
879 kfree(sig_data);
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100880 break;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700881 case AUDIT_TTY_GET: {
882 struct audit_tty_status s;
883 struct task_struct *tsk;
884
885 read_lock(&tasklist_lock);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700886 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700887 if (!tsk)
888 err = -ESRCH;
889 else {
890 spin_lock_irq(&tsk->sighand->siglock);
891 s.enabled = tsk->signal->audit_tty != 0;
892 spin_unlock_irq(&tsk->sighand->siglock);
893 }
894 read_unlock(&tasklist_lock);
895 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_TTY_GET, 0, 0,
896 &s, sizeof(s));
897 break;
898 }
899 case AUDIT_TTY_SET: {
900 struct audit_tty_status *s;
901 struct task_struct *tsk;
902
903 if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
904 return -EINVAL;
905 s = data;
906 if (s->enabled != 0 && s->enabled != 1)
907 return -EINVAL;
908 read_lock(&tasklist_lock);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700909 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700910 if (!tsk)
911 err = -ESRCH;
912 else {
913 spin_lock_irq(&tsk->sighand->siglock);
914 tsk->signal->audit_tty = s->enabled != 0;
915 spin_unlock_irq(&tsk->sighand->siglock);
916 }
917 read_unlock(&tasklist_lock);
918 break;
919 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 default:
921 err = -EINVAL;
922 break;
923 }
924
925 return err < 0 ? err : 0;
926}
927
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700928/*
929 * Get message from skb (based on rtnetlink_rcv_skb). Each message is
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 * processed by audit_receive_msg. Malformed skbs with wrong length are
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700931 * discarded silently.
932 */
Herbert Xu2a0a6eb2005-05-03 14:55:09 -0700933static void audit_receive_skb(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934{
935 int err;
936 struct nlmsghdr *nlh;
937 u32 rlen;
938
939 while (skb->len >= NLMSG_SPACE(0)) {
Arnaldo Carvalho de Melob529ccf2007-04-25 19:08:35 -0700940 nlh = nlmsg_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
Herbert Xu2a0a6eb2005-05-03 14:55:09 -0700942 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
944 if (rlen > skb->len)
945 rlen = skb->len;
946 if ((err = audit_receive_msg(skb, nlh))) {
947 netlink_ack(skb, nlh, err);
948 } else if (nlh->nlmsg_flags & NLM_F_ACK)
949 netlink_ack(skb, nlh, 0);
950 skb_pull(skb, rlen);
951 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952}
953
954/* Receive messages from netlink socket. */
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700955static void audit_receive(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400957 mutex_lock(&audit_cmd_mutex);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700958 audit_receive_skb(skb);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400959 mutex_unlock(&audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960}
961
Amy Griffisf368c07d2006-04-07 16:55:56 -0400962#ifdef CONFIG_AUDITSYSCALL
963static const struct inotify_operations audit_inotify_ops = {
964 .handle_event = audit_handle_ievent,
965 .destroy_watch = audit_free_parent,
966};
967#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
969/* Initialize audit support at boot time. */
970static int __init audit_init(void)
971{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400972 int i;
Amy Griffisf368c07d2006-04-07 16:55:56 -0400973
Eric Parisa3f07112008-11-05 12:47:09 -0500974 if (audit_initialized == AUDIT_DISABLED)
975 return 0;
976
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
978 audit_default ? "enabled" : "disabled");
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200979 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
980 audit_receive, NULL, THIS_MODULE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 if (!audit_sock)
982 audit_panic("cannot initialize netlink socket");
Amy Griffis71e1c782006-03-06 22:40:05 -0500983 else
984 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985
David Woodhouseb7d11252005-05-19 10:56:58 +0100986 skb_queue_head_init(&audit_skb_queue);
Eric Parisf3d357b2008-04-18 10:02:28 -0400987 skb_queue_head_init(&audit_skb_hold_queue);
Eric Parisa3f07112008-11-05 12:47:09 -0500988 audit_initialized = AUDIT_INITIALIZED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -0500990 audit_ever_enabled |= !!audit_default;
Darrel Goeddel3dc7e312006-03-10 18:14:06 -0600991
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100992 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
Amy Griffisf368c07d2006-04-07 16:55:56 -0400993
994#ifdef CONFIG_AUDITSYSCALL
995 audit_ih = inotify_init(&audit_inotify_ops);
996 if (IS_ERR(audit_ih))
997 audit_panic("cannot initialize inotify handle");
Amy Griffis69884342006-07-13 13:17:12 -0400998#endif
Amy Griffisf368c07d2006-04-07 16:55:56 -0400999
1000 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1001 INIT_LIST_HEAD(&audit_inode_hash[i]);
Amy Griffisf368c07d2006-04-07 16:55:56 -04001002
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 return 0;
1004}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005__initcall(audit_init);
1006
1007/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1008static int __init audit_enable(char *str)
1009{
1010 audit_default = !!simple_strtol(str, NULL, 0);
Eric Parisa3f07112008-11-05 12:47:09 -05001011 if (!audit_default)
1012 audit_initialized = AUDIT_DISABLED;
1013
1014 printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
1015
1016 if (audit_initialized == AUDIT_INITIALIZED) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -05001018 audit_ever_enabled |= !!audit_default;
Eric Parisa3f07112008-11-05 12:47:09 -05001019 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
1020 printk(" (after initialization)");
1021 } else {
1022 printk(" (until reboot)");
Eric Parisb593d382008-01-08 17:38:31 -05001023 }
Eric Parisa3f07112008-11-05 12:47:09 -05001024 printk("\n");
1025
OGAWA Hirofumi9b410462006-03-31 02:30:33 -08001026 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027}
1028
1029__setup("audit=", audit_enable);
1030
Chris Wright16e19042005-05-06 15:53:34 +01001031static void audit_buffer_free(struct audit_buffer *ab)
1032{
1033 unsigned long flags;
1034
Chris Wright8fc61152005-05-06 15:54:17 +01001035 if (!ab)
1036 return;
1037
Chris Wright5ac52f32005-05-06 15:54:53 +01001038 if (ab->skb)
1039 kfree_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001040
Chris Wright16e19042005-05-06 15:53:34 +01001041 spin_lock_irqsave(&audit_freelist_lock, flags);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001042 if (audit_freelist_count > AUDIT_MAXFREE)
Chris Wright16e19042005-05-06 15:53:34 +01001043 kfree(ab);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001044 else {
1045 audit_freelist_count++;
Chris Wright16e19042005-05-06 15:53:34 +01001046 list_add(&ab->list, &audit_freelist);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001047 }
Chris Wright16e19042005-05-06 15:53:34 +01001048 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1049}
1050
Steve Grubbc0404992005-05-13 18:17:42 +01001051static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
Al Virodd0fc662005-10-07 07:46:04 +01001052 gfp_t gfp_mask, int type)
Chris Wright16e19042005-05-06 15:53:34 +01001053{
1054 unsigned long flags;
1055 struct audit_buffer *ab = NULL;
Steve Grubbc0404992005-05-13 18:17:42 +01001056 struct nlmsghdr *nlh;
Chris Wright16e19042005-05-06 15:53:34 +01001057
1058 spin_lock_irqsave(&audit_freelist_lock, flags);
1059 if (!list_empty(&audit_freelist)) {
1060 ab = list_entry(audit_freelist.next,
1061 struct audit_buffer, list);
1062 list_del(&ab->list);
1063 --audit_freelist_count;
1064 }
1065 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1066
1067 if (!ab) {
David Woodhouse4332bdd2005-05-06 15:59:57 +01001068 ab = kmalloc(sizeof(*ab), gfp_mask);
Chris Wright16e19042005-05-06 15:53:34 +01001069 if (!ab)
Chris Wright8fc61152005-05-06 15:54:17 +01001070 goto err;
Chris Wright16e19042005-05-06 15:53:34 +01001071 }
Chris Wright8fc61152005-05-06 15:54:17 +01001072
David Woodhouse4332bdd2005-05-06 15:59:57 +01001073 ab->skb = alloc_skb(AUDIT_BUFSIZ, gfp_mask);
Chris Wright5ac52f32005-05-06 15:54:53 +01001074 if (!ab->skb)
Chris Wright8fc61152005-05-06 15:54:17 +01001075 goto err;
1076
David Woodhouseb7d11252005-05-19 10:56:58 +01001077 ab->ctx = ctx;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001078 ab->gfp_mask = gfp_mask;
Steve Grubbc0404992005-05-13 18:17:42 +01001079 nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0));
1080 nlh->nlmsg_type = type;
1081 nlh->nlmsg_flags = 0;
1082 nlh->nlmsg_pid = 0;
1083 nlh->nlmsg_seq = 0;
Chris Wright16e19042005-05-06 15:53:34 +01001084 return ab;
Chris Wright8fc61152005-05-06 15:54:17 +01001085err:
1086 audit_buffer_free(ab);
1087 return NULL;
Chris Wright16e19042005-05-06 15:53:34 +01001088}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001090/**
1091 * audit_serial - compute a serial number for the audit record
1092 *
1093 * Compute a serial number for the audit record. Audit records are
David Woodhousebfb44962005-05-21 21:08:09 +01001094 * written to user-space as soon as they are generated, so a complete
1095 * audit record may be written in several pieces. The timestamp of the
1096 * record and this serial number are used by the user-space tools to
1097 * determine which pieces belong to the same audit record. The
1098 * (timestamp,serial) tuple is unique for each syscall and is live from
1099 * syscall entry to syscall exit.
1100 *
David Woodhousebfb44962005-05-21 21:08:09 +01001101 * NOTE: Another possibility is to store the formatted records off the
1102 * audit context (for those records that have a context), and emit them
1103 * all at syscall exit. However, this could delay the reporting of
1104 * significant errors until syscall exit (or never, if the system
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001105 * halts).
1106 */
David Woodhousebfb44962005-05-21 21:08:09 +01001107unsigned int audit_serial(void)
1108{
Ingo Molnar34af9462006-06-27 02:53:55 -07001109 static DEFINE_SPINLOCK(serial_lock);
David Woodhoused5b454f2005-07-15 12:56:03 +01001110 static unsigned int serial = 0;
David Woodhousebfb44962005-05-21 21:08:09 +01001111
David Woodhoused5b454f2005-07-15 12:56:03 +01001112 unsigned long flags;
1113 unsigned int ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001114
David Woodhoused5b454f2005-07-15 12:56:03 +01001115 spin_lock_irqsave(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001116 do {
David Woodhousece625a82005-07-18 14:24:46 -04001117 ret = ++serial;
1118 } while (unlikely(!ret));
David Woodhoused5b454f2005-07-15 12:56:03 +01001119 spin_unlock_irqrestore(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001120
David Woodhoused5b454f2005-07-15 12:56:03 +01001121 return ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001122}
1123
Daniel Walker5600b892007-10-18 03:06:10 -07001124static inline void audit_get_stamp(struct audit_context *ctx,
David Woodhousebfb44962005-05-21 21:08:09 +01001125 struct timespec *t, unsigned int *serial)
1126{
Al Viro48887e62008-12-06 01:05:50 -05001127 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
David Woodhousebfb44962005-05-21 21:08:09 +01001128 *t = CURRENT_TIME;
1129 *serial = audit_serial();
1130 }
1131}
1132
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133/* Obtain an audit buffer. This routine does locking to obtain the
1134 * audit buffer, but then no locking is required for calls to
1135 * audit_log_*format. If the tsk is a task that is currently in a
1136 * syscall, then the syscall is marked as auditable and an audit record
1137 * will be written at syscall exit. If there is no associated task, tsk
1138 * should be NULL. */
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001139
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001140/**
1141 * audit_log_start - obtain an audit buffer
1142 * @ctx: audit_context (may be NULL)
1143 * @gfp_mask: type of allocation
1144 * @type: audit message type
1145 *
1146 * Returns audit_buffer pointer on success or NULL on error.
1147 *
1148 * Obtain an audit buffer. This routine does locking to obtain the
1149 * audit buffer, but then no locking is required for calls to
1150 * audit_log_*format. If the task (ctx) is a task that is currently in a
1151 * syscall, then the syscall is marked as auditable and an audit record
1152 * will be written at syscall exit. If there is no associated task, then
1153 * task context (ctx) should be NULL.
1154 */
Al Viro9796fdd2005-10-21 03:22:03 -04001155struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001156 int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157{
1158 struct audit_buffer *ab = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 struct timespec t;
Andrew Mortonef00be02008-01-10 11:02:39 -08001160 unsigned int uninitialized_var(serial);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001161 int reserve;
David Woodhouseac4cec42005-07-02 14:08:48 +01001162 unsigned long timeout_start = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163
Eric Parisa3f07112008-11-05 12:47:09 -05001164 if (audit_initialized != AUDIT_INITIALIZED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 return NULL;
1166
Dustin Kirklandc8edc802005-11-03 16:12:36 +00001167 if (unlikely(audit_filter_type(type)))
1168 return NULL;
1169
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001170 if (gfp_mask & __GFP_WAIT)
1171 reserve = 0;
1172 else
Daniel Walker5600b892007-10-18 03:06:10 -07001173 reserve = 5; /* Allow atomic callers to go up to five
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001174 entries over the normal backlog limit */
1175
1176 while (audit_backlog_limit
1177 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
David Woodhouseac4cec42005-07-02 14:08:48 +01001178 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
1179 && time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
1180
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001181 /* Wait for auditd to drain the queue a little */
1182 DECLARE_WAITQUEUE(wait, current);
1183 set_current_state(TASK_INTERRUPTIBLE);
1184 add_wait_queue(&audit_backlog_wait, &wait);
1185
1186 if (audit_backlog_limit &&
1187 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
David Woodhouseac4cec42005-07-02 14:08:48 +01001188 schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001189
1190 __set_current_state(TASK_RUNNING);
1191 remove_wait_queue(&audit_backlog_wait, &wait);
David Woodhouseac4cec42005-07-02 14:08:48 +01001192 continue;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001193 }
Eric Paris320f1b12008-01-23 22:55:05 -05001194 if (audit_rate_check() && printk_ratelimit())
David Woodhousefb19b4c2005-05-19 14:55:56 +01001195 printk(KERN_WARNING
1196 "audit: audit_backlog=%d > "
1197 "audit_backlog_limit=%d\n",
1198 skb_queue_len(&audit_skb_queue),
1199 audit_backlog_limit);
1200 audit_log_lost("backlog limit exceeded");
David Woodhouseac4cec42005-07-02 14:08:48 +01001201 audit_backlog_wait_time = audit_backlog_wait_overflow;
1202 wake_up(&audit_backlog_wait);
David Woodhousefb19b4c2005-05-19 14:55:56 +01001203 return NULL;
1204 }
1205
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001206 ab = audit_buffer_alloc(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207 if (!ab) {
1208 audit_log_lost("out of memory in audit_log_start");
1209 return NULL;
1210 }
1211
David Woodhousebfb44962005-05-21 21:08:09 +01001212 audit_get_stamp(ab->ctx, &t, &serial);
Chris Wright197c69c2005-05-11 10:54:05 +01001213
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1215 t.tv_sec, t.tv_nsec/1000000, serial);
1216 return ab;
1217}
1218
Chris Wright8fc61152005-05-06 15:54:17 +01001219/**
Chris Wright5ac52f32005-05-06 15:54:53 +01001220 * audit_expand - expand skb in the audit buffer
Chris Wright8fc61152005-05-06 15:54:17 +01001221 * @ab: audit_buffer
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001222 * @extra: space to add at tail of the skb
Chris Wright8fc61152005-05-06 15:54:17 +01001223 *
1224 * Returns 0 (no space) on failed expansion, or available space if
1225 * successful.
1226 */
David Woodhousee3b926b2005-05-10 18:56:08 +01001227static inline int audit_expand(struct audit_buffer *ab, int extra)
Chris Wright8fc61152005-05-06 15:54:17 +01001228{
Chris Wright5ac52f32005-05-06 15:54:53 +01001229 struct sk_buff *skb = ab->skb;
Herbert Xu406a1d82008-01-28 20:47:09 -08001230 int oldtail = skb_tailroom(skb);
1231 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1232 int newtail = skb_tailroom(skb);
1233
Chris Wright5ac52f32005-05-06 15:54:53 +01001234 if (ret < 0) {
1235 audit_log_lost("out of memory in audit_expand");
Chris Wright8fc61152005-05-06 15:54:17 +01001236 return 0;
Chris Wright5ac52f32005-05-06 15:54:53 +01001237 }
Herbert Xu406a1d82008-01-28 20:47:09 -08001238
1239 skb->truesize += newtail - oldtail;
1240 return newtail;
Chris Wright8fc61152005-05-06 15:54:17 +01001241}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001243/*
1244 * Format an audit message into the audit buffer. If there isn't enough
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245 * room in the audit buffer, more room will be allocated and vsnprint
1246 * will be called a second time. Currently, we assume that a printk
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001247 * can't format message larger than 1024 bytes, so we don't either.
1248 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1250 va_list args)
1251{
1252 int len, avail;
Chris Wright5ac52f32005-05-06 15:54:53 +01001253 struct sk_buff *skb;
David Woodhouseeecb0a72005-05-10 18:58:51 +01001254 va_list args2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255
1256 if (!ab)
1257 return;
1258
Chris Wright5ac52f32005-05-06 15:54:53 +01001259 BUG_ON(!ab->skb);
1260 skb = ab->skb;
1261 avail = skb_tailroom(skb);
1262 if (avail == 0) {
David Woodhousee3b926b2005-05-10 18:56:08 +01001263 avail = audit_expand(ab, AUDIT_BUFSIZ);
Chris Wright8fc61152005-05-06 15:54:17 +01001264 if (!avail)
1265 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 }
David Woodhouseeecb0a72005-05-10 18:58:51 +01001267 va_copy(args2, args);
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001268 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 if (len >= avail) {
1270 /* The printk buffer is 1024 bytes long, so if we get
1271 * here and AUDIT_BUFSIZ is at least 1024, then we can
1272 * log everything that printk could have logged. */
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001273 avail = audit_expand(ab,
1274 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
Chris Wright8fc61152005-05-06 15:54:17 +01001275 if (!avail)
1276 goto out;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001277 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 }
Richard Knutsson148b38d2008-01-10 11:02:40 -08001279 va_end(args2);
Steve Grubb168b7172005-05-19 10:24:22 +01001280 if (len > 0)
1281 skb_put(skb, len);
Chris Wright8fc61152005-05-06 15:54:17 +01001282out:
1283 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284}
1285
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001286/**
1287 * audit_log_format - format a message into the audit buffer.
1288 * @ab: audit_buffer
1289 * @fmt: format string
1290 * @...: optional parameters matching @fmt string
1291 *
1292 * All the work is done in audit_log_vformat.
1293 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1295{
1296 va_list args;
1297
1298 if (!ab)
1299 return;
1300 va_start(args, fmt);
1301 audit_log_vformat(ab, fmt, args);
1302 va_end(args);
1303}
1304
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001305/**
1306 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1307 * @ab: the audit_buffer
1308 * @buf: buffer to convert to hex
1309 * @len: length of @buf to be converted
1310 *
1311 * No return value; failure to expand is silently ignored.
1312 *
1313 * This function will take the passed buf and convert it into a string of
1314 * ascii hex digits. The new string is placed onto the skb.
1315 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001316void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
Steve Grubb168b7172005-05-19 10:24:22 +01001317 size_t len)
83c7d092005-04-29 15:54:44 +01001318{
Steve Grubb168b7172005-05-19 10:24:22 +01001319 int i, avail, new_len;
1320 unsigned char *ptr;
1321 struct sk_buff *skb;
1322 static const unsigned char *hex = "0123456789ABCDEF";
83c7d092005-04-29 15:54:44 +01001323
Amy Griffis8ef2d302006-09-07 17:03:02 -04001324 if (!ab)
1325 return;
1326
Steve Grubb168b7172005-05-19 10:24:22 +01001327 BUG_ON(!ab->skb);
1328 skb = ab->skb;
1329 avail = skb_tailroom(skb);
1330 new_len = len<<1;
1331 if (new_len >= avail) {
1332 /* Round the buffer request up to the next multiple */
1333 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1334 avail = audit_expand(ab, new_len);
1335 if (!avail)
1336 return;
1337 }
1338
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001339 ptr = skb_tail_pointer(skb);
Steve Grubb168b7172005-05-19 10:24:22 +01001340 for (i=0; i<len; i++) {
1341 *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
1342 *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
1343 }
1344 *ptr = 0;
1345 skb_put(skb, len << 1); /* new string is twice the old string */
83c7d092005-04-29 15:54:44 +01001346}
1347
Amy Griffis9c937dc2006-06-08 23:19:31 -04001348/*
1349 * Format a string of no more than slen characters into the audit buffer,
1350 * enclosed in quote marks.
1351 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001352void audit_log_n_string(struct audit_buffer *ab, const char *string,
1353 size_t slen)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001354{
1355 int avail, new_len;
1356 unsigned char *ptr;
1357 struct sk_buff *skb;
1358
Amy Griffis8ef2d302006-09-07 17:03:02 -04001359 if (!ab)
1360 return;
1361
Amy Griffis9c937dc2006-06-08 23:19:31 -04001362 BUG_ON(!ab->skb);
1363 skb = ab->skb;
1364 avail = skb_tailroom(skb);
1365 new_len = slen + 3; /* enclosing quotes + null terminator */
1366 if (new_len > avail) {
1367 avail = audit_expand(ab, new_len);
1368 if (!avail)
1369 return;
1370 }
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001371 ptr = skb_tail_pointer(skb);
Amy Griffis9c937dc2006-06-08 23:19:31 -04001372 *ptr++ = '"';
1373 memcpy(ptr, string, slen);
1374 ptr += slen;
1375 *ptr++ = '"';
1376 *ptr = 0;
1377 skb_put(skb, slen + 2); /* don't include null terminator */
1378}
1379
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001380/**
Eric Parisde6bbd12008-01-07 14:31:58 -05001381 * audit_string_contains_control - does a string need to be logged in hex
Dave Jonesf706d5d2008-03-28 14:15:56 -07001382 * @string: string to be checked
1383 * @len: max length of the string to check
Eric Parisde6bbd12008-01-07 14:31:58 -05001384 */
1385int audit_string_contains_control(const char *string, size_t len)
1386{
1387 const unsigned char *p;
Miloslav Trmacb3897f52009-03-19 09:48:27 -04001388 for (p = string; p < (const unsigned char *)string + len; p++) {
Vesa-Matti J Kari1d6c9642008-07-23 00:06:13 +03001389 if (*p == '"' || *p < 0x21 || *p > 0x7e)
Eric Parisde6bbd12008-01-07 14:31:58 -05001390 return 1;
1391 }
1392 return 0;
1393}
1394
1395/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001396 * audit_log_n_untrustedstring - log a string that may contain random characters
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001397 * @ab: audit_buffer
Dave Jonesf706d5d2008-03-28 14:15:56 -07001398 * @len: length of string (not including trailing null)
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001399 * @string: string to be logged
1400 *
1401 * This code will escape a string that is passed to it if the string
1402 * contains a control character, unprintable character, double quote mark,
Steve Grubb168b7172005-05-19 10:24:22 +01001403 * or a space. Unescaped strings will start and end with a double quote mark.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001404 * Strings that are escaped are printed in hex (2 digits per char).
Amy Griffis9c937dc2006-06-08 23:19:31 -04001405 *
1406 * The caller specifies the number of characters in the string to log, which may
1407 * or may not be the entire string.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001408 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001409void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1410 size_t len)
83c7d092005-04-29 15:54:44 +01001411{
Eric Parisde6bbd12008-01-07 14:31:58 -05001412 if (audit_string_contains_control(string, len))
Eric Parisb556f8a2008-04-18 10:12:59 -04001413 audit_log_n_hex(ab, string, len);
Eric Parisde6bbd12008-01-07 14:31:58 -05001414 else
Eric Parisb556f8a2008-04-18 10:12:59 -04001415 audit_log_n_string(ab, string, len);
83c7d092005-04-29 15:54:44 +01001416}
1417
Amy Griffis9c937dc2006-06-08 23:19:31 -04001418/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001419 * audit_log_untrustedstring - log a string that may contain random characters
Amy Griffis9c937dc2006-06-08 23:19:31 -04001420 * @ab: audit_buffer
1421 * @string: string to be logged
1422 *
Miloslav Trmac522ed772007-07-15 23:40:56 -07001423 * Same as audit_log_n_untrustedstring(), except that strlen is used to
Amy Griffis9c937dc2006-06-08 23:19:31 -04001424 * determine string length.
1425 */
Eric Parisde6bbd12008-01-07 14:31:58 -05001426void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001427{
Eric Parisb556f8a2008-04-18 10:12:59 -04001428 audit_log_n_untrustedstring(ab, string, strlen(string));
Amy Griffis9c937dc2006-06-08 23:19:31 -04001429}
1430
Steve Grubb168b7172005-05-19 10:24:22 +01001431/* This is a helper-function to print the escaped d_path */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001432void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
Jan Blunck44707fd2008-02-14 19:38:33 -08001433 struct path *path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434{
Jan Blunck44707fd2008-02-14 19:38:33 -08001435 char *p, *pathname;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436
Chris Wright8fc61152005-05-06 15:54:17 +01001437 if (prefix)
1438 audit_log_format(ab, " %s", prefix);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439
Steve Grubb168b7172005-05-19 10:24:22 +01001440 /* We will allow 11 spaces for ' (deleted)' to be appended */
Jan Blunck44707fd2008-02-14 19:38:33 -08001441 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1442 if (!pathname) {
Eric Parisdef57542009-03-10 18:00:14 -04001443 audit_log_string(ab, "<no_memory>");
Steve Grubb168b7172005-05-19 10:24:22 +01001444 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445 }
Jan Blunckcf28b482008-02-14 19:38:44 -08001446 p = d_path(path, pathname, PATH_MAX+11);
Steve Grubb168b7172005-05-19 10:24:22 +01001447 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1448 /* FIXME: can we save some information here? */
Eric Parisdef57542009-03-10 18:00:14 -04001449 audit_log_string(ab, "<too_long>");
Daniel Walker5600b892007-10-18 03:06:10 -07001450 } else
Steve Grubb168b7172005-05-19 10:24:22 +01001451 audit_log_untrustedstring(ab, p);
Jan Blunck44707fd2008-02-14 19:38:33 -08001452 kfree(pathname);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001453}
1454
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001455/**
1456 * audit_log_end - end one audit record
1457 * @ab: the audit_buffer
1458 *
1459 * The netlink_* functions cannot be called inside an irq context, so
1460 * the audit buffer is placed on a queue and a tasklet is scheduled to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 * remove them from the queue outside the irq context. May be called in
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001462 * any context.
1463 */
David Woodhouseb7d11252005-05-19 10:56:58 +01001464void audit_log_end(struct audit_buffer *ab)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001465{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001466 if (!ab)
1467 return;
1468 if (!audit_rate_check()) {
1469 audit_log_lost("rate limit exceeded");
1470 } else {
Steve Grubb8d07a672008-02-21 16:59:22 -05001471 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
Eric Parisf3d357b2008-04-18 10:02:28 -04001472 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1473
David Woodhouseb7d11252005-05-19 10:56:58 +01001474 if (audit_pid) {
David Woodhouseb7d11252005-05-19 10:56:58 +01001475 skb_queue_tail(&audit_skb_queue, ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001476 wake_up_interruptible(&kauditd_wait);
Eric Parisf3d357b2008-04-18 10:02:28 -04001477 } else {
1478 if (nlh->nlmsg_type != AUDIT_EOE) {
1479 if (printk_ratelimit()) {
1480 printk(KERN_NOTICE "type=%d %s\n",
1481 nlh->nlmsg_type,
1482 ab->skb->data + NLMSG_SPACE(0));
1483 } else
1484 audit_log_lost("printk limit exceeded\n");
1485 }
1486 audit_hold_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001487 }
Eric Parisf3d357b2008-04-18 10:02:28 -04001488 ab->skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001489 }
Chris Wright16e19042005-05-06 15:53:34 +01001490 audit_buffer_free(ab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491}
1492
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001493/**
1494 * audit_log - Log an audit record
1495 * @ctx: audit context
1496 * @gfp_mask: type of allocation
1497 * @type: audit message type
1498 * @fmt: format string to use
1499 * @...: variable parameters matching the format string
1500 *
1501 * This is a convenience function that calls audit_log_start,
1502 * audit_log_vformat, and audit_log_end. It may be called
1503 * in any context.
1504 */
Daniel Walker5600b892007-10-18 03:06:10 -07001505void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001506 const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507{
1508 struct audit_buffer *ab;
1509 va_list args;
1510
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001511 ab = audit_log_start(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512 if (ab) {
1513 va_start(args, fmt);
1514 audit_log_vformat(ab, fmt, args);
1515 va_end(args);
1516 audit_log_end(ab);
1517 }
1518}
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01001519
1520EXPORT_SYMBOL(audit_log_start);
1521EXPORT_SYMBOL(audit_log_end);
1522EXPORT_SYMBOL(audit_log_format);
1523EXPORT_SYMBOL(audit_log);