blob: 4414e93d875018b89b6363e2821093c38600d776 [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
64/* No auditing will take place until audit_initialized != 0.
65 * (Initialization happens after skb_init is called.) */
66static int audit_initialized;
67
Eric Paris1a6b9f22008-01-07 17:09:31 -050068#define AUDIT_OFF 0
69#define AUDIT_ON 1
70#define AUDIT_LOCKED 2
Linus Torvalds1da177e2005-04-16 15:20:36 -070071int audit_enabled;
Eric Parisb593d382008-01-08 17:38:31 -050072int audit_ever_enabled;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74/* Default state when kernel boots without any parameters. */
75static int audit_default;
76
77/* If auditing cannot proceed, audit_failure selects what happens. */
78static int audit_failure = AUDIT_FAIL_PRINTK;
79
Pavel Emelyanov75c03712008-03-20 15:39:41 -070080/*
81 * If audit records are to be written to the netlink socket, audit_pid
82 * contains the pid of the auditd process and audit_nlk_pid contains
83 * the pid to use to send netlink messages to that process.
84 */
Steve Grubbc2f0c7c2005-05-06 12:38:39 +010085int audit_pid;
Pavel Emelyanov75c03712008-03-20 15:39:41 -070086static int audit_nlk_pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
Randy Dunlapb0dd25a2005-09-13 12:47:11 -070088/* If audit_rate_limit is non-zero, limit the rate of sending audit records
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 * to that number per second. This prevents DoS attacks, but results in
90 * audit records being dropped. */
91static int audit_rate_limit;
92
93/* Number of outstanding audit_buffers allowed. */
94static int audit_backlog_limit = 64;
David Woodhouseac4cec42005-07-02 14:08:48 +010095static int audit_backlog_wait_time = 60 * HZ;
96static int audit_backlog_wait_overflow = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
Steve Grubbc2f0c7c2005-05-06 12:38:39 +010098/* The identity of the user shutting down the audit system. */
99uid_t audit_sig_uid = -1;
100pid_t audit_sig_pid = -1;
Al Viroe1396062006-05-25 10:19:47 -0400101u32 audit_sig_sid = 0;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103/* Records can be lost in several ways:
104 0) [suppressed in audit_alloc]
105 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
106 2) out of memory in audit_log_move [alloc_skb]
107 3) suppressed due to audit_rate_limit
108 4) suppressed due to audit_backlog_limit
109*/
110static atomic_t audit_lost = ATOMIC_INIT(0);
111
112/* The netlink socket. */
113static struct sock *audit_sock;
114
Amy Griffisf368c07d2006-04-07 16:55:56 -0400115/* Inotify handle. */
116struct inotify_handle *audit_ih;
117
118/* Hash for inode-based rules */
119struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
120
David Woodhouseb7d11252005-05-19 10:56:58 +0100121/* The audit_freelist is a list of pre-allocated audit buffers (if more
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
123 * being placed on the freelist). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124static DEFINE_SPINLOCK(audit_freelist_lock);
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700125static int audit_freelist_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126static LIST_HEAD(audit_freelist);
127
David Woodhouseb7d11252005-05-19 10:56:58 +0100128static struct sk_buff_head audit_skb_queue;
Eric Parisf3d357b2008-04-18 10:02:28 -0400129/* queue of skbs to send to auditd when/if it comes back */
130static struct sk_buff_head audit_skb_hold_queue;
David Woodhouseb7d11252005-05-19 10:56:58 +0100131static struct task_struct *kauditd_task;
132static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100133static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Amy Griffisf368c07d2006-04-07 16:55:56 -0400135/* Serialize requests from userspace. */
136static DEFINE_MUTEX(audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
138/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
139 * audit records. Since printk uses a 1024 byte buffer, this buffer
140 * should be at least that large. */
141#define AUDIT_BUFSIZ 1024
142
143/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
144 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
145#define AUDIT_MAXFREE (2*NR_CPUS)
146
147/* The audit_buffer is used when formatting an audit record. The caller
148 * locks briefly to get the record off the freelist or to allocate the
149 * buffer, and locks briefly to send the buffer to the netlink layer or
150 * to place it on a transmit queue. Multiple audit_buffers can be in
151 * use simultaneously. */
152struct audit_buffer {
153 struct list_head list;
Chris Wright8fc61152005-05-06 15:54:17 +0100154 struct sk_buff *skb; /* formatted skb ready to send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 struct audit_context *ctx; /* NULL or associated context */
Al Viro9796fdd2005-10-21 03:22:03 -0400156 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157};
158
Eric Parisf09ac9d2008-04-18 10:11:04 -0400159struct audit_reply {
160 int pid;
161 struct sk_buff *skb;
162};
163
Steve Grubbc0404992005-05-13 18:17:42 +0100164static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
165{
Eric Paris50397bd2008-01-07 18:14:19 -0500166 if (ab) {
167 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
168 nlh->nlmsg_pid = pid;
169 }
Steve Grubbc0404992005-05-13 18:17:42 +0100170}
171
Dustin Kirkland8c8570f2005-11-03 17:15:16 +0000172void audit_panic(const char *message)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
174 switch (audit_failure)
175 {
176 case AUDIT_FAIL_SILENT:
177 break;
178 case AUDIT_FAIL_PRINTK:
Eric Paris320f1b12008-01-23 22:55:05 -0500179 if (printk_ratelimit())
180 printk(KERN_ERR "audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 break;
182 case AUDIT_FAIL_PANIC:
Eric Parisb29ee872008-02-21 15:53:05 -0500183 /* test audit_pid since printk is always losey, why bother? */
184 if (audit_pid)
185 panic("audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 break;
187 }
188}
189
190static inline int audit_rate_check(void)
191{
192 static unsigned long last_check = 0;
193 static int messages = 0;
194 static DEFINE_SPINLOCK(lock);
195 unsigned long flags;
196 unsigned long now;
197 unsigned long elapsed;
198 int retval = 0;
199
200 if (!audit_rate_limit) return 1;
201
202 spin_lock_irqsave(&lock, flags);
203 if (++messages < audit_rate_limit) {
204 retval = 1;
205 } else {
206 now = jiffies;
207 elapsed = now - last_check;
208 if (elapsed > HZ) {
209 last_check = now;
210 messages = 0;
211 retval = 1;
212 }
213 }
214 spin_unlock_irqrestore(&lock, flags);
215
216 return retval;
217}
218
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700219/**
220 * audit_log_lost - conditionally log lost audit message event
221 * @message: the message stating reason for lost audit message
222 *
223 * Emit at least 1 message per second, even if audit_rate_check is
224 * throttling.
225 * Always increment the lost messages counter.
226*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227void audit_log_lost(const char *message)
228{
229 static unsigned long last_msg = 0;
230 static DEFINE_SPINLOCK(lock);
231 unsigned long flags;
232 unsigned long now;
233 int print;
234
235 atomic_inc(&audit_lost);
236
237 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
238
239 if (!print) {
240 spin_lock_irqsave(&lock, flags);
241 now = jiffies;
242 if (now - last_msg > HZ) {
243 print = 1;
244 last_msg = now;
245 }
246 spin_unlock_irqrestore(&lock, flags);
247 }
248
249 if (print) {
Eric Paris320f1b12008-01-23 22:55:05 -0500250 if (printk_ratelimit())
251 printk(KERN_WARNING
252 "audit: audit_lost=%d audit_rate_limit=%d "
253 "audit_backlog_limit=%d\n",
254 atomic_read(&audit_lost),
255 audit_rate_limit,
256 audit_backlog_limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 audit_panic(message);
258 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259}
260
Eric Paris1a6b9f22008-01-07 17:09:31 -0500261static int audit_log_config_change(char *function_name, int new, int old,
Eric Paris25323862008-04-18 10:09:25 -0400262 uid_t loginuid, u32 sessionid, u32 sid,
263 int allow_changes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500265 struct audit_buffer *ab;
266 int rc = 0;
Steve Grubb6a01b072007-01-19 14:39:55 -0500267
Eric Paris1a6b9f22008-01-07 17:09:31 -0500268 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
Eric Paris25323862008-04-18 10:09:25 -0400269 audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
270 old, loginuid, sessionid);
Steve Grubbce29b682006-04-01 18:29:34 -0500271 if (sid) {
272 char *ctx = NULL;
273 u32 len;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500274
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200275 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500276 if (rc) {
277 audit_log_format(ab, " sid=%u", sid);
278 allow_changes = 0; /* Something weird, deny request */
279 } else {
280 audit_log_format(ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200281 security_release_secctx(ctx, len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500282 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500283 }
Eric Paris1a6b9f22008-01-07 17:09:31 -0500284 audit_log_format(ab, " res=%d", allow_changes);
285 audit_log_end(ab);
286 return rc;
287}
288
289static int audit_do_config_change(char *function_name, int *to_change,
Eric Paris25323862008-04-18 10:09:25 -0400290 int new, uid_t loginuid, u32 sessionid,
291 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500292{
293 int allow_changes, rc = 0, old = *to_change;
294
295 /* check if we are locked */
296 if (audit_enabled == AUDIT_LOCKED)
297 allow_changes = 0;
298 else
299 allow_changes = 1;
300
301 if (audit_enabled != AUDIT_OFF) {
Eric Paris25323862008-04-18 10:09:25 -0400302 rc = audit_log_config_change(function_name, new, old, loginuid,
303 sessionid, sid, allow_changes);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500304 if (rc)
305 allow_changes = 0;
306 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500307
308 /* If we are allowed, make the change */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500309 if (allow_changes == 1)
310 *to_change = new;
Steve Grubb6a01b072007-01-19 14:39:55 -0500311 /* Not allowed, update reason */
312 else if (rc == 0)
313 rc = -EPERM;
314 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315}
316
Eric Paris25323862008-04-18 10:09:25 -0400317static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
318 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500319{
320 return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400321 limit, loginuid, sessionid, sid);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500322}
323
Eric Paris25323862008-04-18 10:09:25 -0400324static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
325 u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500327 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400328 limit, loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329}
330
Eric Paris25323862008-04-18 10:09:25 -0400331static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332{
Eric Parisb593d382008-01-08 17:38:31 -0500333 int rc;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500334 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500336
Eric Parisb593d382008-01-08 17:38:31 -0500337 rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
Eric Paris25323862008-04-18 10:09:25 -0400338 loginuid, sessionid, sid);
Eric Parisb593d382008-01-08 17:38:31 -0500339
340 if (!rc)
341 audit_ever_enabled |= !!state;
342
343 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344}
345
Eric Paris25323862008-04-18 10:09:25 -0400346static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 if (state != AUDIT_FAIL_SILENT
349 && state != AUDIT_FAIL_PRINTK
350 && state != AUDIT_FAIL_PANIC)
351 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500352
Eric Paris1a6b9f22008-01-07 17:09:31 -0500353 return audit_do_config_change("audit_failure", &audit_failure, state,
Eric Paris25323862008-04-18 10:09:25 -0400354 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355}
356
Eric Parisf3d357b2008-04-18 10:02:28 -0400357/*
358 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
359 * already have been sent via prink/syslog and so if these messages are dropped
360 * it is not a huge concern since we already passed the audit_log_lost()
361 * notification and stuff. This is just nice to get audit messages during
362 * boot before auditd is running or messages generated while auditd is stopped.
363 * This only holds messages is audit_default is set, aka booting with audit=1
364 * or building your kernel that way.
365 */
366static void audit_hold_skb(struct sk_buff *skb)
367{
368 if (audit_default &&
369 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
370 skb_queue_tail(&audit_skb_hold_queue, skb);
371 else
372 kfree_skb(skb);
373}
374
375static void kauditd_send_skb(struct sk_buff *skb)
376{
377 int err;
378 /* take a reference in case we can't send it and we want to hold it */
379 skb_get(skb);
380 err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
381 if (err < 0) {
382 BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */
383 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
384 audit_log_lost("auditd dissapeared\n");
385 audit_pid = 0;
386 /* we might get lucky and get this in the next auditd */
387 audit_hold_skb(skb);
388 } else
389 /* drop the extra reference if sent ok */
390 kfree_skb(skb);
391}
392
Adrian Bunk97a41e22006-01-08 01:02:17 -0800393static int kauditd_thread(void *dummy)
David Woodhouseb7d11252005-05-19 10:56:58 +0100394{
395 struct sk_buff *skb;
396
Rafael J. Wysocki83144182007-07-17 04:03:35 -0700397 set_freezable();
Andrew Morton4899b8b2006-10-06 00:43:48 -0700398 while (!kthread_should_stop()) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400399 /*
400 * if auditd just started drain the queue of messages already
401 * sent to syslog/printk. remember loss here is ok. we already
402 * called audit_log_lost() if it didn't go out normally. so the
403 * race between the skb_dequeue and the next check for audit_pid
404 * doesn't matter.
405 *
406 * if you ever find kauditd to be too slow we can get a perf win
407 * by doing our own locking and keeping better track if there
408 * are messages in this queue. I don't see the need now, but
409 * in 5 years when I want to play with this again I'll see this
410 * note and still have no friggin idea what i'm thinking today.
411 */
412 if (audit_default && audit_pid) {
413 skb = skb_dequeue(&audit_skb_hold_queue);
414 if (unlikely(skb)) {
415 while (skb && audit_pid) {
416 kauditd_send_skb(skb);
417 skb = skb_dequeue(&audit_skb_hold_queue);
418 }
419 }
420 }
421
David Woodhouseb7d11252005-05-19 10:56:58 +0100422 skb = skb_dequeue(&audit_skb_queue);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100423 wake_up(&audit_backlog_wait);
David Woodhouseb7d11252005-05-19 10:56:58 +0100424 if (skb) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400425 if (audit_pid)
426 kauditd_send_skb(skb);
427 else {
Eric Paris320f1b12008-01-23 22:55:05 -0500428 if (printk_ratelimit())
Eric Parisf3d357b2008-04-18 10:02:28 -0400429 printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0));
Eric Paris320f1b12008-01-23 22:55:05 -0500430 else
431 audit_log_lost("printk limit exceeded\n");
Eric Parisf3d357b2008-04-18 10:02:28 -0400432
433 audit_hold_skb(skb);
David Woodhouseb7d11252005-05-19 10:56:58 +0100434 }
435 } else {
436 DECLARE_WAITQUEUE(wait, current);
437 set_current_state(TASK_INTERRUPTIBLE);
438 add_wait_queue(&kauditd_wait, &wait);
439
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800440 if (!skb_queue_len(&audit_skb_queue)) {
441 try_to_freeze();
David Woodhouseb7d11252005-05-19 10:56:58 +0100442 schedule();
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800443 }
David Woodhouseb7d11252005-05-19 10:56:58 +0100444
445 __set_current_state(TASK_RUNNING);
446 remove_wait_queue(&kauditd_wait, &wait);
447 }
448 }
Andrew Morton4899b8b2006-10-06 00:43:48 -0700449 return 0;
David Woodhouseb7d11252005-05-19 10:56:58 +0100450}
451
Eric Paris25323862008-04-18 10:09:25 -0400452static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
Miloslav Trmac522ed772007-07-15 23:40:56 -0700453{
454 struct task_struct *tsk;
455 int err;
456
457 read_lock(&tasklist_lock);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700458 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700459 err = -ESRCH;
460 if (!tsk)
461 goto out;
462 err = 0;
463
464 spin_lock_irq(&tsk->sighand->siglock);
465 if (!tsk->signal->audit_tty)
466 err = -EPERM;
467 spin_unlock_irq(&tsk->sighand->siglock);
468 if (err)
469 goto out;
470
Eric Paris25323862008-04-18 10:09:25 -0400471 tty_audit_push_task(tsk, loginuid, sessionid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700472out:
473 read_unlock(&tasklist_lock);
474 return err;
475}
476
Al Viro9044e6b2006-05-22 01:09:24 -0400477int audit_send_list(void *_dest)
478{
479 struct audit_netlink_list *dest = _dest;
480 int pid = dest->pid;
481 struct sk_buff *skb;
482
483 /* wait for parent to finish and send an ACK */
Amy Griffisf368c07d2006-04-07 16:55:56 -0400484 mutex_lock(&audit_cmd_mutex);
485 mutex_unlock(&audit_cmd_mutex);
Al Viro9044e6b2006-05-22 01:09:24 -0400486
487 while ((skb = __skb_dequeue(&dest->q)) != NULL)
488 netlink_unicast(audit_sock, skb, pid, 0);
489
490 kfree(dest);
491
492 return 0;
493}
494
Al Viro74c3cbe2007-07-22 08:04:18 -0400495#ifdef CONFIG_AUDIT_TREE
496static int prune_tree_thread(void *unused)
497{
498 mutex_lock(&audit_cmd_mutex);
499 audit_prune_trees();
500 mutex_unlock(&audit_cmd_mutex);
501 return 0;
502}
503
504void audit_schedule_prune(void)
505{
506 kthread_run(prune_tree_thread, NULL, "audit_prune_tree");
507}
508#endif
509
Al Viro9044e6b2006-05-22 01:09:24 -0400510struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
511 int multi, void *payload, int size)
512{
513 struct sk_buff *skb;
514 struct nlmsghdr *nlh;
515 int len = NLMSG_SPACE(size);
516 void *data;
517 int flags = multi ? NLM_F_MULTI : 0;
518 int t = done ? NLMSG_DONE : type;
519
520 skb = alloc_skb(len, GFP_KERNEL);
521 if (!skb)
522 return NULL;
523
524 nlh = NLMSG_PUT(skb, pid, seq, t, size);
525 nlh->nlmsg_flags = flags;
526 data = NLMSG_DATA(nlh);
527 memcpy(data, payload, size);
528 return skb;
529
530nlmsg_failure: /* Used by NLMSG_PUT */
531 if (skb)
532 kfree_skb(skb);
533 return NULL;
534}
535
Eric Parisf09ac9d2008-04-18 10:11:04 -0400536static int audit_send_reply_thread(void *arg)
537{
538 struct audit_reply *reply = (struct audit_reply *)arg;
539
540 mutex_lock(&audit_cmd_mutex);
541 mutex_unlock(&audit_cmd_mutex);
542
543 /* Ignore failure. It'll only happen if the sender goes away,
544 because our timeout is set to infinite. */
545 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
546 kfree(reply);
547 return 0;
548}
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700549/**
550 * audit_send_reply - send an audit reply message via netlink
551 * @pid: process id to send reply to
552 * @seq: sequence number
553 * @type: audit message type
554 * @done: done (last) flag
555 * @multi: multi-part message flag
556 * @payload: payload data
557 * @size: payload size
558 *
559 * Allocates an skb, builds the netlink message, and sends it to the pid.
560 * No failure notifications.
561 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562void audit_send_reply(int pid, int seq, int type, int done, int multi,
563 void *payload, int size)
564{
Eric Parisf09ac9d2008-04-18 10:11:04 -0400565 struct sk_buff *skb;
566 struct task_struct *tsk;
567 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
568 GFP_KERNEL);
569
570 if (!reply)
571 return;
572
Al Viro9044e6b2006-05-22 01:09:24 -0400573 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 if (!skb)
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700575 goto out;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400576
577 reply->pid = pid;
578 reply->skb = skb;
579
580 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700581 if (!IS_ERR(tsk))
582 return;
583 kfree_skb(skb);
584out:
585 kfree(reply);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586}
587
588/*
589 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
590 * control messages.
591 */
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700592static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593{
594 int err = 0;
595
596 switch (msg_type) {
597 case AUDIT_GET:
598 case AUDIT_LIST:
Amy Griffis93315ed2006-02-07 12:05:27 -0500599 case AUDIT_LIST_RULES:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 case AUDIT_SET:
601 case AUDIT_ADD:
Amy Griffis93315ed2006-02-07 12:05:27 -0500602 case AUDIT_ADD_RULE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500604 case AUDIT_DEL_RULE:
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100605 case AUDIT_SIGNAL_INFO:
Miloslav Trmac522ed772007-07-15 23:40:56 -0700606 case AUDIT_TTY_GET:
607 case AUDIT_TTY_SET:
Al Viro74c3cbe2007-07-22 08:04:18 -0400608 case AUDIT_TRIM:
609 case AUDIT_MAKE_EQUIV:
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700610 if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 err = -EPERM;
612 break;
Steve Grubb05474102005-05-21 00:18:37 +0100613 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700614 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
615 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700616 if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 err = -EPERM;
618 break;
619 default: /* bad msg */
620 err = -EINVAL;
621 }
622
623 return err;
624}
625
Eric Paris50397bd2008-01-07 18:14:19 -0500626static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
Eric Paris25323862008-04-18 10:09:25 -0400627 u32 pid, u32 uid, uid_t auid, u32 ses,
628 u32 sid)
Eric Paris50397bd2008-01-07 18:14:19 -0500629{
630 int rc = 0;
631 char *ctx = NULL;
632 u32 len;
633
634 if (!audit_enabled) {
635 *ab = NULL;
636 return rc;
637 }
638
639 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
Eric Paris25323862008-04-18 10:09:25 -0400640 audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u",
641 pid, uid, auid, ses);
Eric Paris50397bd2008-01-07 18:14:19 -0500642 if (sid) {
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200643 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris50397bd2008-01-07 18:14:19 -0500644 if (rc)
645 audit_log_format(*ab, " ssid=%u", sid);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200646 else {
Eric Paris50397bd2008-01-07 18:14:19 -0500647 audit_log_format(*ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200648 security_release_secctx(ctx, len);
649 }
Eric Paris50397bd2008-01-07 18:14:19 -0500650 }
651
652 return rc;
653}
654
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
656{
Steve Grubbe7c34972006-04-03 09:08:13 -0400657 u32 uid, pid, seq, sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 void *data;
659 struct audit_status *status_get, status_set;
660 int err;
Steve Grubbc0404992005-05-13 18:17:42 +0100661 struct audit_buffer *ab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 u16 msg_type = nlh->nlmsg_type;
Serge Hallync94c2572005-04-29 16:27:17 +0100663 uid_t loginuid; /* loginuid of sender */
Eric Paris25323862008-04-18 10:09:25 -0400664 u32 sessionid;
Al Viroe1396062006-05-25 10:19:47 -0400665 struct audit_sig_info *sig_data;
Eric Paris50397bd2008-01-07 18:14:19 -0500666 char *ctx = NULL;
Al Viroe1396062006-05-25 10:19:47 -0400667 u32 len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700669 err = audit_netlink_ok(skb, msg_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 if (err)
671 return err;
672
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700673 /* As soon as there's any sign of userspace auditd,
674 * start kauditd to talk to it */
David Woodhouseb7d11252005-05-19 10:56:58 +0100675 if (!kauditd_task)
676 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
677 if (IS_ERR(kauditd_task)) {
678 err = PTR_ERR(kauditd_task);
679 kauditd_task = NULL;
680 return err;
681 }
682
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 pid = NETLINK_CREDS(skb)->pid;
684 uid = NETLINK_CREDS(skb)->uid;
Serge Hallync94c2572005-04-29 16:27:17 +0100685 loginuid = NETLINK_CB(skb).loginuid;
Eric Paris25323862008-04-18 10:09:25 -0400686 sessionid = NETLINK_CB(skb).sessionid;
Steve Grubbe7c34972006-04-03 09:08:13 -0400687 sid = NETLINK_CB(skb).sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 seq = nlh->nlmsg_seq;
689 data = NLMSG_DATA(nlh);
690
691 switch (msg_type) {
692 case AUDIT_GET:
693 status_set.enabled = audit_enabled;
694 status_set.failure = audit_failure;
695 status_set.pid = audit_pid;
696 status_set.rate_limit = audit_rate_limit;
697 status_set.backlog_limit = audit_backlog_limit;
698 status_set.lost = atomic_read(&audit_lost);
David Woodhouseb7d11252005-05-19 10:56:58 +0100699 status_set.backlog = skb_queue_len(&audit_skb_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
701 &status_set, sizeof(status_set));
702 break;
703 case AUDIT_SET:
704 if (nlh->nlmsg_len < sizeof(struct audit_status))
705 return -EINVAL;
706 status_get = (struct audit_status *)data;
707 if (status_get->mask & AUDIT_STATUS_ENABLED) {
Steve Grubbce29b682006-04-01 18:29:34 -0500708 err = audit_set_enabled(status_get->enabled,
Eric Paris25323862008-04-18 10:09:25 -0400709 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800710 if (err < 0)
711 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 }
713 if (status_get->mask & AUDIT_STATUS_FAILURE) {
Steve Grubbce29b682006-04-01 18:29:34 -0500714 err = audit_set_failure(status_get->failure,
Eric Paris25323862008-04-18 10:09:25 -0400715 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800716 if (err < 0)
717 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 }
719 if (status_get->mask & AUDIT_STATUS_PID) {
Eric Paris1a6b9f22008-01-07 17:09:31 -0500720 int new_pid = status_get->pid;
721
722 if (audit_enabled != AUDIT_OFF)
723 audit_log_config_change("audit_pid", new_pid,
724 audit_pid, loginuid,
Eric Paris25323862008-04-18 10:09:25 -0400725 sessionid, sid, 1);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500726
727 audit_pid = new_pid;
Pavel Emelyanov75c03712008-03-20 15:39:41 -0700728 audit_nlk_pid = NETLINK_CB(skb).pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 }
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800730 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500731 err = audit_set_rate_limit(status_get->rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400732 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800733 if (err < 0)
734 return err;
735 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500737 err = audit_set_backlog_limit(status_get->backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400738 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 break;
Steve Grubb05474102005-05-21 00:18:37 +0100740 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700741 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
742 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
David Woodhouse4a4cd632005-06-22 14:56:47 +0100743 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
744 return 0;
David Woodhouse0f45aa12005-06-19 19:35:50 +0100745
Peng Haitaod8de7242008-05-20 09:13:02 +0800746 err = audit_filter_user(&NETLINK_CB(skb));
David Woodhouse4a4cd632005-06-22 14:56:47 +0100747 if (err == 1) {
748 err = 0;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700749 if (msg_type == AUDIT_USER_TTY) {
Eric Paris25323862008-04-18 10:09:25 -0400750 err = audit_prepare_user_tty(pid, loginuid,
751 sessionid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700752 if (err)
753 break;
754 }
Eric Paris50397bd2008-01-07 18:14:19 -0500755 audit_log_common_recv_msg(&ab, msg_type, pid, uid,
Eric Paris25323862008-04-18 10:09:25 -0400756 loginuid, sessionid, sid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700757
Eric Paris50397bd2008-01-07 18:14:19 -0500758 if (msg_type != AUDIT_USER_TTY)
759 audit_log_format(ab, " msg='%.1024s'",
760 (char *)data);
761 else {
762 int size;
763
764 audit_log_format(ab, " msg=");
765 size = nlmsg_len(nlh);
Eric Parisb556f8a2008-04-18 10:12:59 -0400766 audit_log_n_untrustedstring(ab, data, size);
David Woodhouse4a4cd632005-06-22 14:56:47 +0100767 }
Eric Paris50397bd2008-01-07 18:14:19 -0500768 audit_set_pid(ab, pid);
769 audit_log_end(ab);
David Woodhouse0f45aa12005-06-19 19:35:50 +0100770 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 break;
772 case AUDIT_ADD:
773 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500774 if (nlmsg_len(nlh) < sizeof(struct audit_rule))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500776 if (audit_enabled == AUDIT_LOCKED) {
Eric Paris50397bd2008-01-07 18:14:19 -0500777 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400778 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500779
780 audit_log_format(ab, " audit_enabled=%d res=0",
781 audit_enabled);
782 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -0500783 return -EPERM;
784 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 /* fallthrough */
786 case AUDIT_LIST:
Peng Haitao13d5ef92008-05-16 10:15:04 +0800787 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
Amy Griffis93315ed2006-02-07 12:05:27 -0500788 uid, seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400789 loginuid, sessionid, sid);
Amy Griffis93315ed2006-02-07 12:05:27 -0500790 break;
791 case AUDIT_ADD_RULE:
792 case AUDIT_DEL_RULE:
793 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
794 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500795 if (audit_enabled == AUDIT_LOCKED) {
Eric Paris50397bd2008-01-07 18:14:19 -0500796 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400797 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500798
799 audit_log_format(ab, " audit_enabled=%d res=0",
800 audit_enabled);
801 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -0500802 return -EPERM;
803 }
Amy Griffis93315ed2006-02-07 12:05:27 -0500804 /* fallthrough */
805 case AUDIT_LIST_RULES:
Peng Haitao13d5ef92008-05-16 10:15:04 +0800806 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
Amy Griffis93315ed2006-02-07 12:05:27 -0500807 uid, seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400808 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 break;
Al Viro74c3cbe2007-07-22 08:04:18 -0400810 case AUDIT_TRIM:
811 audit_trim_trees();
Eric Paris50397bd2008-01-07 18:14:19 -0500812
813 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400814 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500815
Al Viro74c3cbe2007-07-22 08:04:18 -0400816 audit_log_format(ab, " op=trim res=1");
817 audit_log_end(ab);
818 break;
819 case AUDIT_MAKE_EQUIV: {
820 void *bufp = data;
821 u32 sizes[2];
Harvey Harrison7719e432008-04-27 02:39:56 -0700822 size_t msglen = nlmsg_len(nlh);
Al Viro74c3cbe2007-07-22 08:04:18 -0400823 char *old, *new;
824
825 err = -EINVAL;
Harvey Harrison7719e432008-04-27 02:39:56 -0700826 if (msglen < 2 * sizeof(u32))
Al Viro74c3cbe2007-07-22 08:04:18 -0400827 break;
828 memcpy(sizes, bufp, 2 * sizeof(u32));
829 bufp += 2 * sizeof(u32);
Harvey Harrison7719e432008-04-27 02:39:56 -0700830 msglen -= 2 * sizeof(u32);
831 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400832 if (IS_ERR(old)) {
833 err = PTR_ERR(old);
834 break;
835 }
Harvey Harrison7719e432008-04-27 02:39:56 -0700836 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400837 if (IS_ERR(new)) {
838 err = PTR_ERR(new);
839 kfree(old);
840 break;
841 }
842 /* OK, here comes... */
843 err = audit_tag_tree(old, new);
844
Eric Paris50397bd2008-01-07 18:14:19 -0500845 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400846 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500847
Al Viro74c3cbe2007-07-22 08:04:18 -0400848 audit_log_format(ab, " op=make_equiv old=");
849 audit_log_untrustedstring(ab, old);
850 audit_log_format(ab, " new=");
851 audit_log_untrustedstring(ab, new);
852 audit_log_format(ab, " res=%d", !err);
853 audit_log_end(ab);
854 kfree(old);
855 kfree(new);
856 break;
857 }
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100858 case AUDIT_SIGNAL_INFO:
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200859 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
Al Viroe1396062006-05-25 10:19:47 -0400860 if (err)
861 return err;
862 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
863 if (!sig_data) {
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200864 security_release_secctx(ctx, len);
Al Viroe1396062006-05-25 10:19:47 -0400865 return -ENOMEM;
866 }
867 sig_data->uid = audit_sig_uid;
868 sig_data->pid = audit_sig_pid;
869 memcpy(sig_data->ctx, ctx, len);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200870 security_release_secctx(ctx, len);
Daniel Walker5600b892007-10-18 03:06:10 -0700871 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
Al Viroe1396062006-05-25 10:19:47 -0400872 0, 0, sig_data, sizeof(*sig_data) + len);
873 kfree(sig_data);
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100874 break;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700875 case AUDIT_TTY_GET: {
876 struct audit_tty_status s;
877 struct task_struct *tsk;
878
879 read_lock(&tasklist_lock);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700880 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700881 if (!tsk)
882 err = -ESRCH;
883 else {
884 spin_lock_irq(&tsk->sighand->siglock);
885 s.enabled = tsk->signal->audit_tty != 0;
886 spin_unlock_irq(&tsk->sighand->siglock);
887 }
888 read_unlock(&tasklist_lock);
889 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_TTY_GET, 0, 0,
890 &s, sizeof(s));
891 break;
892 }
893 case AUDIT_TTY_SET: {
894 struct audit_tty_status *s;
895 struct task_struct *tsk;
896
897 if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
898 return -EINVAL;
899 s = data;
900 if (s->enabled != 0 && s->enabled != 1)
901 return -EINVAL;
902 read_lock(&tasklist_lock);
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700903 tsk = find_task_by_vpid(pid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700904 if (!tsk)
905 err = -ESRCH;
906 else {
907 spin_lock_irq(&tsk->sighand->siglock);
908 tsk->signal->audit_tty = s->enabled != 0;
909 spin_unlock_irq(&tsk->sighand->siglock);
910 }
911 read_unlock(&tasklist_lock);
912 break;
913 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 default:
915 err = -EINVAL;
916 break;
917 }
918
919 return err < 0 ? err : 0;
920}
921
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700922/*
923 * Get message from skb (based on rtnetlink_rcv_skb). Each message is
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 * processed by audit_receive_msg. Malformed skbs with wrong length are
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700925 * discarded silently.
926 */
Herbert Xu2a0a6eb2005-05-03 14:55:09 -0700927static void audit_receive_skb(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928{
929 int err;
930 struct nlmsghdr *nlh;
931 u32 rlen;
932
933 while (skb->len >= NLMSG_SPACE(0)) {
Arnaldo Carvalho de Melob529ccf2007-04-25 19:08:35 -0700934 nlh = nlmsg_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
Herbert Xu2a0a6eb2005-05-03 14:55:09 -0700936 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 rlen = NLMSG_ALIGN(nlh->nlmsg_len);
938 if (rlen > skb->len)
939 rlen = skb->len;
940 if ((err = audit_receive_msg(skb, nlh))) {
941 netlink_ack(skb, nlh, err);
942 } else if (nlh->nlmsg_flags & NLM_F_ACK)
943 netlink_ack(skb, nlh, 0);
944 skb_pull(skb, rlen);
945 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946}
947
948/* Receive messages from netlink socket. */
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700949static void audit_receive(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400951 mutex_lock(&audit_cmd_mutex);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700952 audit_receive_skb(skb);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400953 mutex_unlock(&audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954}
955
Amy Griffisf368c07d2006-04-07 16:55:56 -0400956#ifdef CONFIG_AUDITSYSCALL
957static const struct inotify_operations audit_inotify_ops = {
958 .handle_event = audit_handle_ievent,
959 .destroy_watch = audit_free_parent,
960};
961#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962
963/* Initialize audit support at boot time. */
964static int __init audit_init(void)
965{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400966 int i;
Amy Griffisf368c07d2006-04-07 16:55:56 -0400967
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
969 audit_default ? "enabled" : "disabled");
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200970 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0,
971 audit_receive, NULL, THIS_MODULE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 if (!audit_sock)
973 audit_panic("cannot initialize netlink socket");
Amy Griffis71e1c782006-03-06 22:40:05 -0500974 else
975 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976
David Woodhouseb7d11252005-05-19 10:56:58 +0100977 skb_queue_head_init(&audit_skb_queue);
Eric Parisf3d357b2008-04-18 10:02:28 -0400978 skb_queue_head_init(&audit_skb_hold_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 audit_initialized = 1;
980 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -0500981 audit_ever_enabled |= !!audit_default;
Darrel Goeddel3dc7e312006-03-10 18:14:06 -0600982
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100983 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
Amy Griffisf368c07d2006-04-07 16:55:56 -0400984
985#ifdef CONFIG_AUDITSYSCALL
986 audit_ih = inotify_init(&audit_inotify_ops);
987 if (IS_ERR(audit_ih))
988 audit_panic("cannot initialize inotify handle");
Amy Griffis69884342006-07-13 13:17:12 -0400989#endif
Amy Griffisf368c07d2006-04-07 16:55:56 -0400990
991 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
992 INIT_LIST_HEAD(&audit_inode_hash[i]);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400993
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 return 0;
995}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996__initcall(audit_init);
997
998/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
999static int __init audit_enable(char *str)
1000{
1001 audit_default = !!simple_strtol(str, NULL, 0);
1002 printk(KERN_INFO "audit: %s%s\n",
1003 audit_default ? "enabled" : "disabled",
1004 audit_initialized ? "" : " (after initialization)");
Eric Parisb593d382008-01-08 17:38:31 -05001005 if (audit_initialized) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -05001007 audit_ever_enabled |= !!audit_default;
1008 }
OGAWA Hirofumi9b410462006-03-31 02:30:33 -08001009 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010}
1011
1012__setup("audit=", audit_enable);
1013
Chris Wright16e19042005-05-06 15:53:34 +01001014static void audit_buffer_free(struct audit_buffer *ab)
1015{
1016 unsigned long flags;
1017
Chris Wright8fc61152005-05-06 15:54:17 +01001018 if (!ab)
1019 return;
1020
Chris Wright5ac52f32005-05-06 15:54:53 +01001021 if (ab->skb)
1022 kfree_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001023
Chris Wright16e19042005-05-06 15:53:34 +01001024 spin_lock_irqsave(&audit_freelist_lock, flags);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001025 if (audit_freelist_count > AUDIT_MAXFREE)
Chris Wright16e19042005-05-06 15:53:34 +01001026 kfree(ab);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001027 else {
1028 audit_freelist_count++;
Chris Wright16e19042005-05-06 15:53:34 +01001029 list_add(&ab->list, &audit_freelist);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001030 }
Chris Wright16e19042005-05-06 15:53:34 +01001031 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1032}
1033
Steve Grubbc0404992005-05-13 18:17:42 +01001034static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
Al Virodd0fc662005-10-07 07:46:04 +01001035 gfp_t gfp_mask, int type)
Chris Wright16e19042005-05-06 15:53:34 +01001036{
1037 unsigned long flags;
1038 struct audit_buffer *ab = NULL;
Steve Grubbc0404992005-05-13 18:17:42 +01001039 struct nlmsghdr *nlh;
Chris Wright16e19042005-05-06 15:53:34 +01001040
1041 spin_lock_irqsave(&audit_freelist_lock, flags);
1042 if (!list_empty(&audit_freelist)) {
1043 ab = list_entry(audit_freelist.next,
1044 struct audit_buffer, list);
1045 list_del(&ab->list);
1046 --audit_freelist_count;
1047 }
1048 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1049
1050 if (!ab) {
David Woodhouse4332bdd2005-05-06 15:59:57 +01001051 ab = kmalloc(sizeof(*ab), gfp_mask);
Chris Wright16e19042005-05-06 15:53:34 +01001052 if (!ab)
Chris Wright8fc61152005-05-06 15:54:17 +01001053 goto err;
Chris Wright16e19042005-05-06 15:53:34 +01001054 }
Chris Wright8fc61152005-05-06 15:54:17 +01001055
David Woodhouse4332bdd2005-05-06 15:59:57 +01001056 ab->skb = alloc_skb(AUDIT_BUFSIZ, gfp_mask);
Chris Wright5ac52f32005-05-06 15:54:53 +01001057 if (!ab->skb)
Chris Wright8fc61152005-05-06 15:54:17 +01001058 goto err;
1059
David Woodhouseb7d11252005-05-19 10:56:58 +01001060 ab->ctx = ctx;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001061 ab->gfp_mask = gfp_mask;
Steve Grubbc0404992005-05-13 18:17:42 +01001062 nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0));
1063 nlh->nlmsg_type = type;
1064 nlh->nlmsg_flags = 0;
1065 nlh->nlmsg_pid = 0;
1066 nlh->nlmsg_seq = 0;
Chris Wright16e19042005-05-06 15:53:34 +01001067 return ab;
Chris Wright8fc61152005-05-06 15:54:17 +01001068err:
1069 audit_buffer_free(ab);
1070 return NULL;
Chris Wright16e19042005-05-06 15:53:34 +01001071}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001073/**
1074 * audit_serial - compute a serial number for the audit record
1075 *
1076 * Compute a serial number for the audit record. Audit records are
David Woodhousebfb44962005-05-21 21:08:09 +01001077 * written to user-space as soon as they are generated, so a complete
1078 * audit record may be written in several pieces. The timestamp of the
1079 * record and this serial number are used by the user-space tools to
1080 * determine which pieces belong to the same audit record. The
1081 * (timestamp,serial) tuple is unique for each syscall and is live from
1082 * syscall entry to syscall exit.
1083 *
David Woodhousebfb44962005-05-21 21:08:09 +01001084 * NOTE: Another possibility is to store the formatted records off the
1085 * audit context (for those records that have a context), and emit them
1086 * all at syscall exit. However, this could delay the reporting of
1087 * significant errors until syscall exit (or never, if the system
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001088 * halts).
1089 */
David Woodhousebfb44962005-05-21 21:08:09 +01001090unsigned int audit_serial(void)
1091{
Ingo Molnar34af9462006-06-27 02:53:55 -07001092 static DEFINE_SPINLOCK(serial_lock);
David Woodhoused5b454f2005-07-15 12:56:03 +01001093 static unsigned int serial = 0;
David Woodhousebfb44962005-05-21 21:08:09 +01001094
David Woodhoused5b454f2005-07-15 12:56:03 +01001095 unsigned long flags;
1096 unsigned int ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001097
David Woodhoused5b454f2005-07-15 12:56:03 +01001098 spin_lock_irqsave(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001099 do {
David Woodhousece625a82005-07-18 14:24:46 -04001100 ret = ++serial;
1101 } while (unlikely(!ret));
David Woodhoused5b454f2005-07-15 12:56:03 +01001102 spin_unlock_irqrestore(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001103
David Woodhoused5b454f2005-07-15 12:56:03 +01001104 return ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001105}
1106
Daniel Walker5600b892007-10-18 03:06:10 -07001107static inline void audit_get_stamp(struct audit_context *ctx,
David Woodhousebfb44962005-05-21 21:08:09 +01001108 struct timespec *t, unsigned int *serial)
1109{
1110 if (ctx)
1111 auditsc_get_stamp(ctx, t, serial);
1112 else {
1113 *t = CURRENT_TIME;
1114 *serial = audit_serial();
1115 }
1116}
1117
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118/* Obtain an audit buffer. This routine does locking to obtain the
1119 * audit buffer, but then no locking is required for calls to
1120 * audit_log_*format. If the tsk is a task that is currently in a
1121 * syscall, then the syscall is marked as auditable and an audit record
1122 * will be written at syscall exit. If there is no associated task, tsk
1123 * should be NULL. */
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001124
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001125/**
1126 * audit_log_start - obtain an audit buffer
1127 * @ctx: audit_context (may be NULL)
1128 * @gfp_mask: type of allocation
1129 * @type: audit message type
1130 *
1131 * Returns audit_buffer pointer on success or NULL on error.
1132 *
1133 * 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 task (ctx) 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, then
1138 * task context (ctx) should be NULL.
1139 */
Al Viro9796fdd2005-10-21 03:22:03 -04001140struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001141 int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142{
1143 struct audit_buffer *ab = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 struct timespec t;
Andrew Mortonef00be02008-01-10 11:02:39 -08001145 unsigned int uninitialized_var(serial);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001146 int reserve;
David Woodhouseac4cec42005-07-02 14:08:48 +01001147 unsigned long timeout_start = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148
1149 if (!audit_initialized)
1150 return NULL;
1151
Dustin Kirklandc8edc802005-11-03 16:12:36 +00001152 if (unlikely(audit_filter_type(type)))
1153 return NULL;
1154
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001155 if (gfp_mask & __GFP_WAIT)
1156 reserve = 0;
1157 else
Daniel Walker5600b892007-10-18 03:06:10 -07001158 reserve = 5; /* Allow atomic callers to go up to five
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001159 entries over the normal backlog limit */
1160
1161 while (audit_backlog_limit
1162 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
David Woodhouseac4cec42005-07-02 14:08:48 +01001163 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
1164 && time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
1165
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001166 /* Wait for auditd to drain the queue a little */
1167 DECLARE_WAITQUEUE(wait, current);
1168 set_current_state(TASK_INTERRUPTIBLE);
1169 add_wait_queue(&audit_backlog_wait, &wait);
1170
1171 if (audit_backlog_limit &&
1172 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
David Woodhouseac4cec42005-07-02 14:08:48 +01001173 schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001174
1175 __set_current_state(TASK_RUNNING);
1176 remove_wait_queue(&audit_backlog_wait, &wait);
David Woodhouseac4cec42005-07-02 14:08:48 +01001177 continue;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001178 }
Eric Paris320f1b12008-01-23 22:55:05 -05001179 if (audit_rate_check() && printk_ratelimit())
David Woodhousefb19b4c2005-05-19 14:55:56 +01001180 printk(KERN_WARNING
1181 "audit: audit_backlog=%d > "
1182 "audit_backlog_limit=%d\n",
1183 skb_queue_len(&audit_skb_queue),
1184 audit_backlog_limit);
1185 audit_log_lost("backlog limit exceeded");
David Woodhouseac4cec42005-07-02 14:08:48 +01001186 audit_backlog_wait_time = audit_backlog_wait_overflow;
1187 wake_up(&audit_backlog_wait);
David Woodhousefb19b4c2005-05-19 14:55:56 +01001188 return NULL;
1189 }
1190
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001191 ab = audit_buffer_alloc(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 if (!ab) {
1193 audit_log_lost("out of memory in audit_log_start");
1194 return NULL;
1195 }
1196
David Woodhousebfb44962005-05-21 21:08:09 +01001197 audit_get_stamp(ab->ctx, &t, &serial);
Chris Wright197c69c2005-05-11 10:54:05 +01001198
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1200 t.tv_sec, t.tv_nsec/1000000, serial);
1201 return ab;
1202}
1203
Chris Wright8fc61152005-05-06 15:54:17 +01001204/**
Chris Wright5ac52f32005-05-06 15:54:53 +01001205 * audit_expand - expand skb in the audit buffer
Chris Wright8fc61152005-05-06 15:54:17 +01001206 * @ab: audit_buffer
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001207 * @extra: space to add at tail of the skb
Chris Wright8fc61152005-05-06 15:54:17 +01001208 *
1209 * Returns 0 (no space) on failed expansion, or available space if
1210 * successful.
1211 */
David Woodhousee3b926b2005-05-10 18:56:08 +01001212static inline int audit_expand(struct audit_buffer *ab, int extra)
Chris Wright8fc61152005-05-06 15:54:17 +01001213{
Chris Wright5ac52f32005-05-06 15:54:53 +01001214 struct sk_buff *skb = ab->skb;
Herbert Xu406a1d82008-01-28 20:47:09 -08001215 int oldtail = skb_tailroom(skb);
1216 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1217 int newtail = skb_tailroom(skb);
1218
Chris Wright5ac52f32005-05-06 15:54:53 +01001219 if (ret < 0) {
1220 audit_log_lost("out of memory in audit_expand");
Chris Wright8fc61152005-05-06 15:54:17 +01001221 return 0;
Chris Wright5ac52f32005-05-06 15:54:53 +01001222 }
Herbert Xu406a1d82008-01-28 20:47:09 -08001223
1224 skb->truesize += newtail - oldtail;
1225 return newtail;
Chris Wright8fc61152005-05-06 15:54:17 +01001226}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001228/*
1229 * Format an audit message into the audit buffer. If there isn't enough
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 * room in the audit buffer, more room will be allocated and vsnprint
1231 * will be called a second time. Currently, we assume that a printk
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001232 * can't format message larger than 1024 bytes, so we don't either.
1233 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1235 va_list args)
1236{
1237 int len, avail;
Chris Wright5ac52f32005-05-06 15:54:53 +01001238 struct sk_buff *skb;
David Woodhouseeecb0a72005-05-10 18:58:51 +01001239 va_list args2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240
1241 if (!ab)
1242 return;
1243
Chris Wright5ac52f32005-05-06 15:54:53 +01001244 BUG_ON(!ab->skb);
1245 skb = ab->skb;
1246 avail = skb_tailroom(skb);
1247 if (avail == 0) {
David Woodhousee3b926b2005-05-10 18:56:08 +01001248 avail = audit_expand(ab, AUDIT_BUFSIZ);
Chris Wright8fc61152005-05-06 15:54:17 +01001249 if (!avail)
1250 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 }
David Woodhouseeecb0a72005-05-10 18:58:51 +01001252 va_copy(args2, args);
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001253 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 if (len >= avail) {
1255 /* The printk buffer is 1024 bytes long, so if we get
1256 * here and AUDIT_BUFSIZ is at least 1024, then we can
1257 * log everything that printk could have logged. */
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001258 avail = audit_expand(ab,
1259 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
Chris Wright8fc61152005-05-06 15:54:17 +01001260 if (!avail)
1261 goto out;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001262 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 }
Richard Knutsson148b38d2008-01-10 11:02:40 -08001264 va_end(args2);
Steve Grubb168b7172005-05-19 10:24:22 +01001265 if (len > 0)
1266 skb_put(skb, len);
Chris Wright8fc61152005-05-06 15:54:17 +01001267out:
1268 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269}
1270
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001271/**
1272 * audit_log_format - format a message into the audit buffer.
1273 * @ab: audit_buffer
1274 * @fmt: format string
1275 * @...: optional parameters matching @fmt string
1276 *
1277 * All the work is done in audit_log_vformat.
1278 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1280{
1281 va_list args;
1282
1283 if (!ab)
1284 return;
1285 va_start(args, fmt);
1286 audit_log_vformat(ab, fmt, args);
1287 va_end(args);
1288}
1289
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001290/**
1291 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1292 * @ab: the audit_buffer
1293 * @buf: buffer to convert to hex
1294 * @len: length of @buf to be converted
1295 *
1296 * No return value; failure to expand is silently ignored.
1297 *
1298 * This function will take the passed buf and convert it into a string of
1299 * ascii hex digits. The new string is placed onto the skb.
1300 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001301void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
Steve Grubb168b7172005-05-19 10:24:22 +01001302 size_t len)
83c7d092005-04-29 15:54:44 +01001303{
Steve Grubb168b7172005-05-19 10:24:22 +01001304 int i, avail, new_len;
1305 unsigned char *ptr;
1306 struct sk_buff *skb;
1307 static const unsigned char *hex = "0123456789ABCDEF";
83c7d092005-04-29 15:54:44 +01001308
Amy Griffis8ef2d302006-09-07 17:03:02 -04001309 if (!ab)
1310 return;
1311
Steve Grubb168b7172005-05-19 10:24:22 +01001312 BUG_ON(!ab->skb);
1313 skb = ab->skb;
1314 avail = skb_tailroom(skb);
1315 new_len = len<<1;
1316 if (new_len >= avail) {
1317 /* Round the buffer request up to the next multiple */
1318 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1319 avail = audit_expand(ab, new_len);
1320 if (!avail)
1321 return;
1322 }
1323
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001324 ptr = skb_tail_pointer(skb);
Steve Grubb168b7172005-05-19 10:24:22 +01001325 for (i=0; i<len; i++) {
1326 *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
1327 *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
1328 }
1329 *ptr = 0;
1330 skb_put(skb, len << 1); /* new string is twice the old string */
83c7d092005-04-29 15:54:44 +01001331}
1332
Amy Griffis9c937dc2006-06-08 23:19:31 -04001333/*
1334 * Format a string of no more than slen characters into the audit buffer,
1335 * enclosed in quote marks.
1336 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001337void audit_log_n_string(struct audit_buffer *ab, const char *string,
1338 size_t slen)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001339{
1340 int avail, new_len;
1341 unsigned char *ptr;
1342 struct sk_buff *skb;
1343
Amy Griffis8ef2d302006-09-07 17:03:02 -04001344 if (!ab)
1345 return;
1346
Amy Griffis9c937dc2006-06-08 23:19:31 -04001347 BUG_ON(!ab->skb);
1348 skb = ab->skb;
1349 avail = skb_tailroom(skb);
1350 new_len = slen + 3; /* enclosing quotes + null terminator */
1351 if (new_len > avail) {
1352 avail = audit_expand(ab, new_len);
1353 if (!avail)
1354 return;
1355 }
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001356 ptr = skb_tail_pointer(skb);
Amy Griffis9c937dc2006-06-08 23:19:31 -04001357 *ptr++ = '"';
1358 memcpy(ptr, string, slen);
1359 ptr += slen;
1360 *ptr++ = '"';
1361 *ptr = 0;
1362 skb_put(skb, slen + 2); /* don't include null terminator */
1363}
1364
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001365/**
Eric Parisde6bbd12008-01-07 14:31:58 -05001366 * audit_string_contains_control - does a string need to be logged in hex
Dave Jonesf706d5d2008-03-28 14:15:56 -07001367 * @string: string to be checked
1368 * @len: max length of the string to check
Eric Parisde6bbd12008-01-07 14:31:58 -05001369 */
1370int audit_string_contains_control(const char *string, size_t len)
1371{
1372 const unsigned char *p;
1373 for (p = string; p < (const unsigned char *)string + len && *p; p++) {
Vesa-Matti J Kari1d6c9642008-07-23 00:06:13 +03001374 if (*p == '"' || *p < 0x21 || *p > 0x7e)
Eric Parisde6bbd12008-01-07 14:31:58 -05001375 return 1;
1376 }
1377 return 0;
1378}
1379
1380/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001381 * audit_log_n_untrustedstring - log a string that may contain random characters
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001382 * @ab: audit_buffer
Dave Jonesf706d5d2008-03-28 14:15:56 -07001383 * @len: length of string (not including trailing null)
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001384 * @string: string to be logged
1385 *
1386 * This code will escape a string that is passed to it if the string
1387 * contains a control character, unprintable character, double quote mark,
Steve Grubb168b7172005-05-19 10:24:22 +01001388 * or a space. Unescaped strings will start and end with a double quote mark.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001389 * Strings that are escaped are printed in hex (2 digits per char).
Amy Griffis9c937dc2006-06-08 23:19:31 -04001390 *
1391 * The caller specifies the number of characters in the string to log, which may
1392 * or may not be the entire string.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001393 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001394void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1395 size_t len)
83c7d092005-04-29 15:54:44 +01001396{
Eric Parisde6bbd12008-01-07 14:31:58 -05001397 if (audit_string_contains_control(string, len))
Eric Parisb556f8a2008-04-18 10:12:59 -04001398 audit_log_n_hex(ab, string, len);
Eric Parisde6bbd12008-01-07 14:31:58 -05001399 else
Eric Parisb556f8a2008-04-18 10:12:59 -04001400 audit_log_n_string(ab, string, len);
83c7d092005-04-29 15:54:44 +01001401}
1402
Amy Griffis9c937dc2006-06-08 23:19:31 -04001403/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001404 * audit_log_untrustedstring - log a string that may contain random characters
Amy Griffis9c937dc2006-06-08 23:19:31 -04001405 * @ab: audit_buffer
1406 * @string: string to be logged
1407 *
Miloslav Trmac522ed772007-07-15 23:40:56 -07001408 * Same as audit_log_n_untrustedstring(), except that strlen is used to
Amy Griffis9c937dc2006-06-08 23:19:31 -04001409 * determine string length.
1410 */
Eric Parisde6bbd12008-01-07 14:31:58 -05001411void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001412{
Eric Parisb556f8a2008-04-18 10:12:59 -04001413 audit_log_n_untrustedstring(ab, string, strlen(string));
Amy Griffis9c937dc2006-06-08 23:19:31 -04001414}
1415
Steve Grubb168b7172005-05-19 10:24:22 +01001416/* This is a helper-function to print the escaped d_path */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
Jan Blunck44707fd2008-02-14 19:38:33 -08001418 struct path *path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419{
Jan Blunck44707fd2008-02-14 19:38:33 -08001420 char *p, *pathname;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421
Chris Wright8fc61152005-05-06 15:54:17 +01001422 if (prefix)
1423 audit_log_format(ab, " %s", prefix);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424
Steve Grubb168b7172005-05-19 10:24:22 +01001425 /* We will allow 11 spaces for ' (deleted)' to be appended */
Jan Blunck44707fd2008-02-14 19:38:33 -08001426 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1427 if (!pathname) {
Steve Grubb168b7172005-05-19 10:24:22 +01001428 audit_log_format(ab, "<no memory>");
1429 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430 }
Jan Blunckcf28b482008-02-14 19:38:44 -08001431 p = d_path(path, pathname, PATH_MAX+11);
Steve Grubb168b7172005-05-19 10:24:22 +01001432 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1433 /* FIXME: can we save some information here? */
1434 audit_log_format(ab, "<too long>");
Daniel Walker5600b892007-10-18 03:06:10 -07001435 } else
Steve Grubb168b7172005-05-19 10:24:22 +01001436 audit_log_untrustedstring(ab, p);
Jan Blunck44707fd2008-02-14 19:38:33 -08001437 kfree(pathname);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438}
1439
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001440/**
1441 * audit_log_end - end one audit record
1442 * @ab: the audit_buffer
1443 *
1444 * The netlink_* functions cannot be called inside an irq context, so
1445 * the audit buffer is placed on a queue and a tasklet is scheduled to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001446 * remove them from the queue outside the irq context. May be called in
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001447 * any context.
1448 */
David Woodhouseb7d11252005-05-19 10:56:58 +01001449void audit_log_end(struct audit_buffer *ab)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451 if (!ab)
1452 return;
1453 if (!audit_rate_check()) {
1454 audit_log_lost("rate limit exceeded");
1455 } else {
Steve Grubb8d07a672008-02-21 16:59:22 -05001456 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
Eric Parisf3d357b2008-04-18 10:02:28 -04001457 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1458
David Woodhouseb7d11252005-05-19 10:56:58 +01001459 if (audit_pid) {
David Woodhouseb7d11252005-05-19 10:56:58 +01001460 skb_queue_tail(&audit_skb_queue, ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001461 wake_up_interruptible(&kauditd_wait);
Eric Parisf3d357b2008-04-18 10:02:28 -04001462 } else {
1463 if (nlh->nlmsg_type != AUDIT_EOE) {
1464 if (printk_ratelimit()) {
1465 printk(KERN_NOTICE "type=%d %s\n",
1466 nlh->nlmsg_type,
1467 ab->skb->data + NLMSG_SPACE(0));
1468 } else
1469 audit_log_lost("printk limit exceeded\n");
1470 }
1471 audit_hold_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001472 }
Eric Parisf3d357b2008-04-18 10:02:28 -04001473 ab->skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001474 }
Chris Wright16e19042005-05-06 15:53:34 +01001475 audit_buffer_free(ab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476}
1477
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001478/**
1479 * audit_log - Log an audit record
1480 * @ctx: audit context
1481 * @gfp_mask: type of allocation
1482 * @type: audit message type
1483 * @fmt: format string to use
1484 * @...: variable parameters matching the format string
1485 *
1486 * This is a convenience function that calls audit_log_start,
1487 * audit_log_vformat, and audit_log_end. It may be called
1488 * in any context.
1489 */
Daniel Walker5600b892007-10-18 03:06:10 -07001490void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001491 const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492{
1493 struct audit_buffer *ab;
1494 va_list args;
1495
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001496 ab = audit_log_start(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001497 if (ab) {
1498 va_start(args, fmt);
1499 audit_log_vformat(ab, fmt, args);
1500 va_end(args);
1501 audit_log_end(ab);
1502 }
1503}
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01001504
1505EXPORT_SYMBOL(audit_log_start);
1506EXPORT_SYMBOL(audit_log_end);
1507EXPORT_SYMBOL(audit_log_format);
1508EXPORT_SYMBOL(audit_log);