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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>
Arun Sharma600634972011-07-26 16:09:06 -070046#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/mm.h>
Paul Gortmaker9984de12011-05-23 14:51:41 -040048#include <linux/export.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090049#include <linux/slab.h>
David Woodhouseb7d11252005-05-19 10:56:58 +010050#include <linux/err.h>
51#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53#include <linux/audit.h>
54
55#include <net/sock.h>
Amy Griffis93315ed2006-02-07 12:05:27 -050056#include <net/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070057#include <linux/skbuff.h>
Mr Dash Four131ad622011-06-30 13:31:57 +020058#ifdef CONFIG_SECURITY
59#include <linux/security.h>
60#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#include <linux/netlink.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080062#include <linux/freezer.h>
Miloslav Trmac522ed772007-07-15 23:40:56 -070063#include <linux/tty.h>
Eric W. Biederman34e36d82012-09-10 23:20:20 -070064#include <linux/pid_namespace.h>
Darrel Goeddel3dc7e312006-03-10 18:14:06 -060065
66#include "audit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
Eric Parisa3f07112008-11-05 12:47:09 -050068/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 * (Initialization happens after skb_init is called.) */
Eric Parisa3f07112008-11-05 12:47:09 -050070#define AUDIT_DISABLED -1
71#define AUDIT_UNINITIALIZED 0
72#define AUDIT_INITIALIZED 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070073static int audit_initialized;
74
Eric Paris1a6b9f22008-01-07 17:09:31 -050075#define AUDIT_OFF 0
76#define AUDIT_ON 1
77#define AUDIT_LOCKED 2
Linus Torvalds1da177e2005-04-16 15:20:36 -070078int audit_enabled;
Eric Parisb593d382008-01-08 17:38:31 -050079int audit_ever_enabled;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Jan Engelhardtae9d67af2011-01-18 06:48:12 +010081EXPORT_SYMBOL_GPL(audit_enabled);
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083/* Default state when kernel boots without any parameters. */
84static int audit_default;
85
86/* If auditing cannot proceed, audit_failure selects what happens. */
87static int audit_failure = AUDIT_FAIL_PRINTK;
88
Pavel Emelyanov75c03712008-03-20 15:39:41 -070089/*
90 * If audit records are to be written to the netlink socket, audit_pid
91 * contains the pid of the auditd process and audit_nlk_pid contains
92 * the pid to use to send netlink messages to that process.
93 */
Steve Grubbc2f0c7c2005-05-06 12:38:39 +010094int audit_pid;
Pavel Emelyanov75c03712008-03-20 15:39:41 -070095static int audit_nlk_pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
Randy Dunlapb0dd25a2005-09-13 12:47:11 -070097/* If audit_rate_limit is non-zero, limit the rate of sending audit records
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 * to that number per second. This prevents DoS attacks, but results in
99 * audit records being dropped. */
100static int audit_rate_limit;
101
102/* Number of outstanding audit_buffers allowed. */
103static int audit_backlog_limit = 64;
David Woodhouseac4cec42005-07-02 14:08:48 +0100104static int audit_backlog_wait_time = 60 * HZ;
105static int audit_backlog_wait_overflow = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100107/* The identity of the user shutting down the audit system. */
108uid_t audit_sig_uid = -1;
109pid_t audit_sig_pid = -1;
Al Viroe1396062006-05-25 10:19:47 -0400110u32 audit_sig_sid = 0;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112/* Records can be lost in several ways:
113 0) [suppressed in audit_alloc]
114 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
115 2) out of memory in audit_log_move [alloc_skb]
116 3) suppressed due to audit_rate_limit
117 4) suppressed due to audit_backlog_limit
118*/
119static atomic_t audit_lost = ATOMIC_INIT(0);
120
121/* The netlink socket. */
122static struct sock *audit_sock;
123
Amy Griffisf368c07d2006-04-07 16:55:56 -0400124/* Hash for inode-based rules */
125struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
126
David Woodhouseb7d11252005-05-19 10:56:58 +0100127/* The audit_freelist is a list of pre-allocated audit buffers (if more
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
129 * being placed on the freelist). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130static DEFINE_SPINLOCK(audit_freelist_lock);
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700131static int audit_freelist_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132static LIST_HEAD(audit_freelist);
133
David Woodhouseb7d11252005-05-19 10:56:58 +0100134static struct sk_buff_head audit_skb_queue;
Eric Parisf3d357b2008-04-18 10:02:28 -0400135/* queue of skbs to send to auditd when/if it comes back */
136static struct sk_buff_head audit_skb_hold_queue;
David Woodhouseb7d11252005-05-19 10:56:58 +0100137static struct task_struct *kauditd_task;
138static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100139static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
Amy Griffisf368c07d2006-04-07 16:55:56 -0400141/* Serialize requests from userspace. */
Al Viro916d7572009-06-24 00:02:38 -0400142DEFINE_MUTEX(audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
145 * audit records. Since printk uses a 1024 byte buffer, this buffer
146 * should be at least that large. */
147#define AUDIT_BUFSIZ 1024
148
149/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
150 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
151#define AUDIT_MAXFREE (2*NR_CPUS)
152
153/* The audit_buffer is used when formatting an audit record. The caller
154 * locks briefly to get the record off the freelist or to allocate the
155 * buffer, and locks briefly to send the buffer to the netlink layer or
156 * to place it on a transmit queue. Multiple audit_buffers can be in
157 * use simultaneously. */
158struct audit_buffer {
159 struct list_head list;
Chris Wright8fc61152005-05-06 15:54:17 +0100160 struct sk_buff *skb; /* formatted skb ready to send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 struct audit_context *ctx; /* NULL or associated context */
Al Viro9796fdd2005-10-21 03:22:03 -0400162 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163};
164
Eric Parisf09ac9d2008-04-18 10:11:04 -0400165struct audit_reply {
166 int pid;
167 struct sk_buff *skb;
168};
169
Steve Grubbc0404992005-05-13 18:17:42 +0100170static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
171{
Eric Paris50397bd2008-01-07 18:14:19 -0500172 if (ab) {
173 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
174 nlh->nlmsg_pid = pid;
175 }
Steve Grubbc0404992005-05-13 18:17:42 +0100176}
177
Dustin Kirkland8c8570f2005-11-03 17:15:16 +0000178void audit_panic(const char *message)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
180 switch (audit_failure)
181 {
182 case AUDIT_FAIL_SILENT:
183 break;
184 case AUDIT_FAIL_PRINTK:
Eric Paris320f1b12008-01-23 22:55:05 -0500185 if (printk_ratelimit())
186 printk(KERN_ERR "audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 break;
188 case AUDIT_FAIL_PANIC:
Eric Parisb29ee872008-02-21 15:53:05 -0500189 /* test audit_pid since printk is always losey, why bother? */
190 if (audit_pid)
191 panic("audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 break;
193 }
194}
195
196static inline int audit_rate_check(void)
197{
198 static unsigned long last_check = 0;
199 static int messages = 0;
200 static DEFINE_SPINLOCK(lock);
201 unsigned long flags;
202 unsigned long now;
203 unsigned long elapsed;
204 int retval = 0;
205
206 if (!audit_rate_limit) return 1;
207
208 spin_lock_irqsave(&lock, flags);
209 if (++messages < audit_rate_limit) {
210 retval = 1;
211 } else {
212 now = jiffies;
213 elapsed = now - last_check;
214 if (elapsed > HZ) {
215 last_check = now;
216 messages = 0;
217 retval = 1;
218 }
219 }
220 spin_unlock_irqrestore(&lock, flags);
221
222 return retval;
223}
224
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700225/**
226 * audit_log_lost - conditionally log lost audit message event
227 * @message: the message stating reason for lost audit message
228 *
229 * Emit at least 1 message per second, even if audit_rate_check is
230 * throttling.
231 * Always increment the lost messages counter.
232*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233void audit_log_lost(const char *message)
234{
235 static unsigned long last_msg = 0;
236 static DEFINE_SPINLOCK(lock);
237 unsigned long flags;
238 unsigned long now;
239 int print;
240
241 atomic_inc(&audit_lost);
242
243 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
244
245 if (!print) {
246 spin_lock_irqsave(&lock, flags);
247 now = jiffies;
248 if (now - last_msg > HZ) {
249 print = 1;
250 last_msg = now;
251 }
252 spin_unlock_irqrestore(&lock, flags);
253 }
254
255 if (print) {
Eric Paris320f1b12008-01-23 22:55:05 -0500256 if (printk_ratelimit())
257 printk(KERN_WARNING
258 "audit: audit_lost=%d audit_rate_limit=%d "
259 "audit_backlog_limit=%d\n",
260 atomic_read(&audit_lost),
261 audit_rate_limit,
262 audit_backlog_limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 audit_panic(message);
264 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
Eric Paris1a6b9f22008-01-07 17:09:31 -0500267static int audit_log_config_change(char *function_name, int new, int old,
Eric Paris25323862008-04-18 10:09:25 -0400268 uid_t loginuid, u32 sessionid, u32 sid,
269 int allow_changes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500271 struct audit_buffer *ab;
272 int rc = 0;
Steve Grubb6a01b072007-01-19 14:39:55 -0500273
Eric Paris1a6b9f22008-01-07 17:09:31 -0500274 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
Eric Paris25323862008-04-18 10:09:25 -0400275 audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
276 old, loginuid, sessionid);
Steve Grubbce29b682006-04-01 18:29:34 -0500277 if (sid) {
278 char *ctx = NULL;
279 u32 len;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500280
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200281 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500282 if (rc) {
283 audit_log_format(ab, " sid=%u", sid);
284 allow_changes = 0; /* Something weird, deny request */
285 } else {
286 audit_log_format(ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200287 security_release_secctx(ctx, len);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500288 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500289 }
Eric Paris1a6b9f22008-01-07 17:09:31 -0500290 audit_log_format(ab, " res=%d", allow_changes);
291 audit_log_end(ab);
292 return rc;
293}
294
295static int audit_do_config_change(char *function_name, int *to_change,
Eric Paris25323862008-04-18 10:09:25 -0400296 int new, uid_t loginuid, u32 sessionid,
297 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500298{
299 int allow_changes, rc = 0, old = *to_change;
300
301 /* check if we are locked */
302 if (audit_enabled == AUDIT_LOCKED)
303 allow_changes = 0;
304 else
305 allow_changes = 1;
306
307 if (audit_enabled != AUDIT_OFF) {
Eric Paris25323862008-04-18 10:09:25 -0400308 rc = audit_log_config_change(function_name, new, old, loginuid,
309 sessionid, sid, allow_changes);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500310 if (rc)
311 allow_changes = 0;
312 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500313
314 /* If we are allowed, make the change */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500315 if (allow_changes == 1)
316 *to_change = new;
Steve Grubb6a01b072007-01-19 14:39:55 -0500317 /* Not allowed, update reason */
318 else if (rc == 0)
319 rc = -EPERM;
320 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321}
322
Eric Paris25323862008-04-18 10:09:25 -0400323static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
324 u32 sid)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500325{
326 return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400327 limit, loginuid, sessionid, sid);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500328}
329
Eric Paris25323862008-04-18 10:09:25 -0400330static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
331 u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500333 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400334 limit, loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335}
336
Eric Paris25323862008-04-18 10:09:25 -0400337static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338{
Eric Parisb593d382008-01-08 17:38:31 -0500339 int rc;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500340 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500342
Eric Parisb593d382008-01-08 17:38:31 -0500343 rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
Eric Paris25323862008-04-18 10:09:25 -0400344 loginuid, sessionid, sid);
Eric Parisb593d382008-01-08 17:38:31 -0500345
346 if (!rc)
347 audit_ever_enabled |= !!state;
348
349 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350}
351
Eric Paris25323862008-04-18 10:09:25 -0400352static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 if (state != AUDIT_FAIL_SILENT
355 && state != AUDIT_FAIL_PRINTK
356 && state != AUDIT_FAIL_PANIC)
357 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500358
Eric Paris1a6b9f22008-01-07 17:09:31 -0500359 return audit_do_config_change("audit_failure", &audit_failure, state,
Eric Paris25323862008-04-18 10:09:25 -0400360 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361}
362
Eric Parisf3d357b2008-04-18 10:02:28 -0400363/*
364 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
365 * already have been sent via prink/syslog and so if these messages are dropped
366 * it is not a huge concern since we already passed the audit_log_lost()
367 * notification and stuff. This is just nice to get audit messages during
368 * boot before auditd is running or messages generated while auditd is stopped.
369 * This only holds messages is audit_default is set, aka booting with audit=1
370 * or building your kernel that way.
371 */
372static void audit_hold_skb(struct sk_buff *skb)
373{
374 if (audit_default &&
375 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
376 skb_queue_tail(&audit_skb_hold_queue, skb);
377 else
378 kfree_skb(skb);
379}
380
Eric Paris038cbcf2009-06-11 14:31:35 -0400381/*
382 * For one reason or another this nlh isn't getting delivered to the userspace
383 * audit daemon, just send it to printk.
384 */
385static void audit_printk_skb(struct sk_buff *skb)
386{
387 struct nlmsghdr *nlh = nlmsg_hdr(skb);
David S. Millerc64e66c2012-06-26 21:45:21 -0700388 char *data = nlmsg_data(nlh);
Eric Paris038cbcf2009-06-11 14:31:35 -0400389
390 if (nlh->nlmsg_type != AUDIT_EOE) {
391 if (printk_ratelimit())
392 printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
393 else
394 audit_log_lost("printk limit exceeded\n");
395 }
396
397 audit_hold_skb(skb);
398}
399
Eric Parisf3d357b2008-04-18 10:02:28 -0400400static void kauditd_send_skb(struct sk_buff *skb)
401{
402 int err;
403 /* take a reference in case we can't send it and we want to hold it */
404 skb_get(skb);
405 err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
406 if (err < 0) {
Adam Buchbinderc9404c92009-12-18 15:40:42 -0500407 BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
Eric Parisf3d357b2008-04-18 10:02:28 -0400408 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
Ross Kirk9db3b9b2010-10-22 16:43:17 +0100409 audit_log_lost("auditd disappeared\n");
Eric Parisf3d357b2008-04-18 10:02:28 -0400410 audit_pid = 0;
411 /* we might get lucky and get this in the next auditd */
412 audit_hold_skb(skb);
413 } else
414 /* drop the extra reference if sent ok */
Neil Horman70d4bf62010-07-20 06:45:56 +0000415 consume_skb(skb);
Eric Parisf3d357b2008-04-18 10:02:28 -0400416}
417
Adrian Bunk97a41e22006-01-08 01:02:17 -0800418static int kauditd_thread(void *dummy)
David Woodhouseb7d11252005-05-19 10:56:58 +0100419{
420 struct sk_buff *skb;
421
Rafael J. Wysocki83144182007-07-17 04:03:35 -0700422 set_freezable();
Andrew Morton4899b8b2006-10-06 00:43:48 -0700423 while (!kthread_should_stop()) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400424 /*
425 * if auditd just started drain the queue of messages already
426 * sent to syslog/printk. remember loss here is ok. we already
427 * called audit_log_lost() if it didn't go out normally. so the
428 * race between the skb_dequeue and the next check for audit_pid
429 * doesn't matter.
430 *
431 * if you ever find kauditd to be too slow we can get a perf win
432 * by doing our own locking and keeping better track if there
433 * are messages in this queue. I don't see the need now, but
434 * in 5 years when I want to play with this again I'll see this
435 * note and still have no friggin idea what i'm thinking today.
436 */
437 if (audit_default && audit_pid) {
438 skb = skb_dequeue(&audit_skb_hold_queue);
439 if (unlikely(skb)) {
440 while (skb && audit_pid) {
441 kauditd_send_skb(skb);
442 skb = skb_dequeue(&audit_skb_hold_queue);
443 }
444 }
445 }
446
David Woodhouseb7d11252005-05-19 10:56:58 +0100447 skb = skb_dequeue(&audit_skb_queue);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100448 wake_up(&audit_backlog_wait);
David Woodhouseb7d11252005-05-19 10:56:58 +0100449 if (skb) {
Eric Parisf3d357b2008-04-18 10:02:28 -0400450 if (audit_pid)
451 kauditd_send_skb(skb);
Eric Paris038cbcf2009-06-11 14:31:35 -0400452 else
453 audit_printk_skb(skb);
David Woodhouseb7d11252005-05-19 10:56:58 +0100454 } else {
455 DECLARE_WAITQUEUE(wait, current);
456 set_current_state(TASK_INTERRUPTIBLE);
457 add_wait_queue(&kauditd_wait, &wait);
458
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800459 if (!skb_queue_len(&audit_skb_queue)) {
460 try_to_freeze();
David Woodhouseb7d11252005-05-19 10:56:58 +0100461 schedule();
Pierre Ossman7a4ae742005-12-12 00:37:22 -0800462 }
David Woodhouseb7d11252005-05-19 10:56:58 +0100463
464 __set_current_state(TASK_RUNNING);
465 remove_wait_queue(&kauditd_wait, &wait);
466 }
467 }
Andrew Morton4899b8b2006-10-06 00:43:48 -0700468 return 0;
David Woodhouseb7d11252005-05-19 10:56:58 +0100469}
470
Eric Paris25323862008-04-18 10:09:25 -0400471static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
Miloslav Trmac522ed772007-07-15 23:40:56 -0700472{
473 struct task_struct *tsk;
474 int err;
475
Thomas Gleixner3c80fe42009-12-09 14:19:31 +0000476 rcu_read_lock();
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700477 tsk = find_task_by_vpid(pid);
Thomas Gleixner3c80fe42009-12-09 14:19:31 +0000478 if (!tsk) {
479 rcu_read_unlock();
480 return -ESRCH;
481 }
482 get_task_struct(tsk);
483 rcu_read_unlock();
484 err = tty_audit_push_task(tsk, loginuid, sessionid);
485 put_task_struct(tsk);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700486 return err;
487}
488
Al Viro9044e6b2006-05-22 01:09:24 -0400489int audit_send_list(void *_dest)
490{
491 struct audit_netlink_list *dest = _dest;
492 int pid = dest->pid;
493 struct sk_buff *skb;
494
495 /* wait for parent to finish and send an ACK */
Amy Griffisf368c07d2006-04-07 16:55:56 -0400496 mutex_lock(&audit_cmd_mutex);
497 mutex_unlock(&audit_cmd_mutex);
Al Viro9044e6b2006-05-22 01:09:24 -0400498
499 while ((skb = __skb_dequeue(&dest->q)) != NULL)
500 netlink_unicast(audit_sock, skb, pid, 0);
501
502 kfree(dest);
503
504 return 0;
505}
506
507struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
Stephen Hemmingerb8800aa2010-10-20 17:23:50 -0700508 int multi, const void *payload, int size)
Al Viro9044e6b2006-05-22 01:09:24 -0400509{
510 struct sk_buff *skb;
511 struct nlmsghdr *nlh;
Al Viro9044e6b2006-05-22 01:09:24 -0400512 void *data;
513 int flags = multi ? NLM_F_MULTI : 0;
514 int t = done ? NLMSG_DONE : type;
515
Eric Parisee080e62009-06-11 14:31:35 -0400516 skb = nlmsg_new(size, GFP_KERNEL);
Al Viro9044e6b2006-05-22 01:09:24 -0400517 if (!skb)
518 return NULL;
519
David S. Millerc64e66c2012-06-26 21:45:21 -0700520 nlh = nlmsg_put(skb, pid, seq, t, size, flags);
521 if (!nlh)
522 goto out_kfree_skb;
523 data = nlmsg_data(nlh);
Al Viro9044e6b2006-05-22 01:09:24 -0400524 memcpy(data, payload, size);
525 return skb;
526
David S. Millerc64e66c2012-06-26 21:45:21 -0700527out_kfree_skb:
528 kfree_skb(skb);
Al Viro9044e6b2006-05-22 01:09:24 -0400529 return NULL;
530}
531
Eric Parisf09ac9d2008-04-18 10:11:04 -0400532static int audit_send_reply_thread(void *arg)
533{
534 struct audit_reply *reply = (struct audit_reply *)arg;
535
536 mutex_lock(&audit_cmd_mutex);
537 mutex_unlock(&audit_cmd_mutex);
538
539 /* Ignore failure. It'll only happen if the sender goes away,
540 because our timeout is set to infinite. */
541 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
542 kfree(reply);
543 return 0;
544}
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700545/**
546 * audit_send_reply - send an audit reply message via netlink
547 * @pid: process id to send reply to
548 * @seq: sequence number
549 * @type: audit message type
550 * @done: done (last) flag
551 * @multi: multi-part message flag
552 * @payload: payload data
553 * @size: payload size
554 *
555 * Allocates an skb, builds the netlink message, and sends it to the pid.
556 * No failure notifications.
557 */
Stephen Hemmingerb8800aa2010-10-20 17:23:50 -0700558static void audit_send_reply(int pid, int seq, int type, int done, int multi,
559 const void *payload, int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560{
Eric Parisf09ac9d2008-04-18 10:11:04 -0400561 struct sk_buff *skb;
562 struct task_struct *tsk;
563 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
564 GFP_KERNEL);
565
566 if (!reply)
567 return;
568
Al Viro9044e6b2006-05-22 01:09:24 -0400569 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 if (!skb)
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700571 goto out;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400572
573 reply->pid = pid;
574 reply->skb = skb;
575
576 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
Andrew Mortonfcaf1eb2008-05-14 16:11:48 -0700577 if (!IS_ERR(tsk))
578 return;
579 kfree_skb(skb);
580out:
581 kfree(reply);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582}
583
584/*
585 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
586 * control messages.
587 */
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700588static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589{
590 int err = 0;
591
Eric W. Biederman34e36d82012-09-10 23:20:20 -0700592 /* Only support the initial namespaces for now. */
593 if ((current_user_ns() != &init_user_ns) ||
594 (task_active_pid_ns(current) != &init_pid_ns))
595 return -EPERM;
596
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 switch (msg_type) {
598 case AUDIT_GET:
599 case AUDIT_LIST:
Amy Griffis93315ed2006-02-07 12:05:27 -0500600 case AUDIT_LIST_RULES:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 case AUDIT_SET:
602 case AUDIT_ADD:
Amy Griffis93315ed2006-02-07 12:05:27 -0500603 case AUDIT_ADD_RULE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500605 case AUDIT_DEL_RULE:
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100606 case AUDIT_SIGNAL_INFO:
Miloslav Trmac522ed772007-07-15 23:40:56 -0700607 case AUDIT_TTY_GET:
608 case AUDIT_TTY_SET:
Al Viro74c3cbe2007-07-22 08:04:18 -0400609 case AUDIT_TRIM:
610 case AUDIT_MAKE_EQUIV:
Eric Parisfd778462012-01-03 12:25:16 -0500611 if (!capable(CAP_AUDIT_CONTROL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 err = -EPERM;
613 break;
Steve Grubb05474102005-05-21 00:18:37 +0100614 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700615 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
616 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
Eric Parisfd778462012-01-03 12:25:16 -0500617 if (!capable(CAP_AUDIT_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 err = -EPERM;
619 break;
620 default: /* bad msg */
621 err = -EINVAL;
622 }
623
624 return err;
625}
626
Eric Paris50397bd2008-01-07 18:14:19 -0500627static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
Eric Paris25323862008-04-18 10:09:25 -0400628 u32 pid, u32 uid, uid_t auid, u32 ses,
629 u32 sid)
Eric Paris50397bd2008-01-07 18:14:19 -0500630{
631 int rc = 0;
632 char *ctx = NULL;
633 u32 len;
634
635 if (!audit_enabled) {
636 *ab = NULL;
637 return rc;
638 }
639
640 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
Eric Paris3035c512012-01-03 14:23:05 -0500641 audit_log_format(*ab, "pid=%d uid=%u auid=%u ses=%u",
Eric Paris25323862008-04-18 10:09:25 -0400642 pid, uid, auid, ses);
Eric Paris50397bd2008-01-07 18:14:19 -0500643 if (sid) {
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200644 rc = security_secid_to_secctx(sid, &ctx, &len);
Eric Paris50397bd2008-01-07 18:14:19 -0500645 if (rc)
646 audit_log_format(*ab, " ssid=%u", sid);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200647 else {
Eric Paris50397bd2008-01-07 18:14:19 -0500648 audit_log_format(*ab, " subj=%s", ctx);
Ahmed S. Darwish2a862b32008-03-01 21:54:38 +0200649 security_release_secctx(ctx, len);
650 }
Eric Paris50397bd2008-01-07 18:14:19 -0500651 }
652
653 return rc;
654}
655
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
657{
Steve Grubbe7c34972006-04-03 09:08:13 -0400658 u32 uid, pid, seq, sid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 void *data;
660 struct audit_status *status_get, status_set;
661 int err;
Steve Grubbc0404992005-05-13 18:17:42 +0100662 struct audit_buffer *ab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 u16 msg_type = nlh->nlmsg_type;
Serge Hallync94c2572005-04-29 16:27:17 +0100664 uid_t loginuid; /* loginuid of sender */
Eric Paris25323862008-04-18 10:09:25 -0400665 u32 sessionid;
Al Viroe1396062006-05-25 10:19:47 -0400666 struct audit_sig_info *sig_data;
Eric Paris50397bd2008-01-07 18:14:19 -0500667 char *ctx = NULL;
Al Viroe1396062006-05-25 10:19:47 -0400668 u32 len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700670 err = audit_netlink_ok(skb, msg_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 if (err)
672 return err;
673
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700674 /* As soon as there's any sign of userspace auditd,
675 * start kauditd to talk to it */
David Woodhouseb7d11252005-05-19 10:56:58 +0100676 if (!kauditd_task)
677 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
678 if (IS_ERR(kauditd_task)) {
679 err = PTR_ERR(kauditd_task);
680 kauditd_task = NULL;
681 return err;
682 }
683
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 pid = NETLINK_CREDS(skb)->pid;
685 uid = NETLINK_CREDS(skb)->uid;
Patrick McHardyc53fa1e2011-03-03 10:55:40 -0800686 loginuid = audit_get_loginuid(current);
687 sessionid = audit_get_sessionid(current);
688 security_task_getsecid(current, &sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 seq = nlh->nlmsg_seq;
David S. Millerc64e66c2012-06-26 21:45:21 -0700690 data = nlmsg_data(nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691
692 switch (msg_type) {
693 case AUDIT_GET:
694 status_set.enabled = audit_enabled;
695 status_set.failure = audit_failure;
696 status_set.pid = audit_pid;
697 status_set.rate_limit = audit_rate_limit;
698 status_set.backlog_limit = audit_backlog_limit;
699 status_set.lost = atomic_read(&audit_lost);
David Woodhouseb7d11252005-05-19 10:56:58 +0100700 status_set.backlog = skb_queue_len(&audit_skb_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
702 &status_set, sizeof(status_set));
703 break;
704 case AUDIT_SET:
705 if (nlh->nlmsg_len < sizeof(struct audit_status))
706 return -EINVAL;
707 status_get = (struct audit_status *)data;
708 if (status_get->mask & AUDIT_STATUS_ENABLED) {
Steve Grubbce29b682006-04-01 18:29:34 -0500709 err = audit_set_enabled(status_get->enabled,
Eric Paris25323862008-04-18 10:09:25 -0400710 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800711 if (err < 0)
712 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 }
714 if (status_get->mask & AUDIT_STATUS_FAILURE) {
Steve Grubbce29b682006-04-01 18:29:34 -0500715 err = audit_set_failure(status_get->failure,
Eric Paris25323862008-04-18 10:09:25 -0400716 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800717 if (err < 0)
718 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 }
720 if (status_get->mask & AUDIT_STATUS_PID) {
Eric Paris1a6b9f22008-01-07 17:09:31 -0500721 int new_pid = status_get->pid;
722
723 if (audit_enabled != AUDIT_OFF)
724 audit_log_config_change("audit_pid", new_pid,
725 audit_pid, loginuid,
Eric Paris25323862008-04-18 10:09:25 -0400726 sessionid, sid, 1);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500727
728 audit_pid = new_pid;
Pavel Emelyanov75c03712008-03-20 15:39:41 -0700729 audit_nlk_pid = NETLINK_CB(skb).pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 }
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800731 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500732 err = audit_set_rate_limit(status_get->rate_limit,
Eric Paris25323862008-04-18 10:09:25 -0400733 loginuid, sessionid, sid);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800734 if (err < 0)
735 return err;
736 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
Serge E. Hallyn5d136a02006-04-27 16:45:14 -0500738 err = audit_set_backlog_limit(status_get->backlog_limit,
Eric Paris25323862008-04-18 10:09:25 -0400739 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 break;
Steve Grubb05474102005-05-21 00:18:37 +0100741 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700742 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
743 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
David Woodhouse4a4cd632005-06-22 14:56:47 +0100744 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
745 return 0;
David Woodhouse0f45aa12005-06-19 19:35:50 +0100746
Eric W. Biederman02276bd2012-09-10 23:10:16 -0700747 err = audit_filter_user();
David Woodhouse4a4cd632005-06-22 14:56:47 +0100748 if (err == 1) {
749 err = 0;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700750 if (msg_type == AUDIT_USER_TTY) {
Eric Paris25323862008-04-18 10:09:25 -0400751 err = audit_prepare_user_tty(pid, loginuid,
752 sessionid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700753 if (err)
754 break;
755 }
Eric Paris50397bd2008-01-07 18:14:19 -0500756 audit_log_common_recv_msg(&ab, msg_type, pid, uid,
Eric Paris25323862008-04-18 10:09:25 -0400757 loginuid, sessionid, sid);
Miloslav Trmac522ed772007-07-15 23:40:56 -0700758
Eric Paris50397bd2008-01-07 18:14:19 -0500759 if (msg_type != AUDIT_USER_TTY)
760 audit_log_format(ab, " msg='%.1024s'",
761 (char *)data);
762 else {
763 int size;
764
765 audit_log_format(ab, " msg=");
766 size = nlmsg_len(nlh);
Miloslav Trmac55ad2f82009-03-19 09:52:47 -0400767 if (size > 0 &&
768 ((unsigned char *)data)[size - 1] == '\0')
769 size--;
Eric Parisb556f8a2008-04-18 10:12:59 -0400770 audit_log_n_untrustedstring(ab, data, size);
David Woodhouse4a4cd632005-06-22 14:56:47 +0100771 }
Eric Paris50397bd2008-01-07 18:14:19 -0500772 audit_set_pid(ab, pid);
773 audit_log_end(ab);
David Woodhouse0f45aa12005-06-19 19:35:50 +0100774 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 break;
776 case AUDIT_ADD:
777 case AUDIT_DEL:
Amy Griffis93315ed2006-02-07 12:05:27 -0500778 if (nlmsg_len(nlh) < sizeof(struct audit_rule))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500780 if (audit_enabled == AUDIT_LOCKED) {
Eric Paris50397bd2008-01-07 18:14:19 -0500781 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400782 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500783
784 audit_log_format(ab, " audit_enabled=%d res=0",
785 audit_enabled);
786 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -0500787 return -EPERM;
788 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 /* fallthrough */
790 case AUDIT_LIST:
Peng Haitao13d5ef92008-05-16 10:15:04 +0800791 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
Amy Griffis93315ed2006-02-07 12:05:27 -0500792 uid, seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400793 loginuid, sessionid, sid);
Amy Griffis93315ed2006-02-07 12:05:27 -0500794 break;
795 case AUDIT_ADD_RULE:
796 case AUDIT_DEL_RULE:
797 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
798 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500799 if (audit_enabled == AUDIT_LOCKED) {
Eric Paris50397bd2008-01-07 18:14:19 -0500800 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400801 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500802
803 audit_log_format(ab, " audit_enabled=%d res=0",
804 audit_enabled);
805 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -0500806 return -EPERM;
807 }
Amy Griffis93315ed2006-02-07 12:05:27 -0500808 /* fallthrough */
809 case AUDIT_LIST_RULES:
Peng Haitao13d5ef92008-05-16 10:15:04 +0800810 err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
Amy Griffis93315ed2006-02-07 12:05:27 -0500811 uid, seq, data, nlmsg_len(nlh),
Eric Paris25323862008-04-18 10:09:25 -0400812 loginuid, sessionid, sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 break;
Al Viro74c3cbe2007-07-22 08:04:18 -0400814 case AUDIT_TRIM:
815 audit_trim_trees();
Eric Paris50397bd2008-01-07 18:14:19 -0500816
817 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400818 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500819
Al Viro74c3cbe2007-07-22 08:04:18 -0400820 audit_log_format(ab, " op=trim res=1");
821 audit_log_end(ab);
822 break;
823 case AUDIT_MAKE_EQUIV: {
824 void *bufp = data;
825 u32 sizes[2];
Harvey Harrison7719e432008-04-27 02:39:56 -0700826 size_t msglen = nlmsg_len(nlh);
Al Viro74c3cbe2007-07-22 08:04:18 -0400827 char *old, *new;
828
829 err = -EINVAL;
Harvey Harrison7719e432008-04-27 02:39:56 -0700830 if (msglen < 2 * sizeof(u32))
Al Viro74c3cbe2007-07-22 08:04:18 -0400831 break;
832 memcpy(sizes, bufp, 2 * sizeof(u32));
833 bufp += 2 * sizeof(u32);
Harvey Harrison7719e432008-04-27 02:39:56 -0700834 msglen -= 2 * sizeof(u32);
835 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400836 if (IS_ERR(old)) {
837 err = PTR_ERR(old);
838 break;
839 }
Harvey Harrison7719e432008-04-27 02:39:56 -0700840 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
Al Viro74c3cbe2007-07-22 08:04:18 -0400841 if (IS_ERR(new)) {
842 err = PTR_ERR(new);
843 kfree(old);
844 break;
845 }
846 /* OK, here comes... */
847 err = audit_tag_tree(old, new);
848
Eric Paris50397bd2008-01-07 18:14:19 -0500849 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
Eric Paris25323862008-04-18 10:09:25 -0400850 uid, loginuid, sessionid, sid);
Eric Paris50397bd2008-01-07 18:14:19 -0500851
Al Viro74c3cbe2007-07-22 08:04:18 -0400852 audit_log_format(ab, " op=make_equiv old=");
853 audit_log_untrustedstring(ab, old);
854 audit_log_format(ab, " new=");
855 audit_log_untrustedstring(ab, new);
856 audit_log_format(ab, " res=%d", !err);
857 audit_log_end(ab);
858 kfree(old);
859 kfree(new);
860 break;
861 }
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100862 case AUDIT_SIGNAL_INFO:
Eric Paris939cbf22009-09-23 13:46:00 -0400863 len = 0;
864 if (audit_sig_sid) {
865 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
866 if (err)
867 return err;
868 }
Al Viroe1396062006-05-25 10:19:47 -0400869 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
870 if (!sig_data) {
Eric Paris939cbf22009-09-23 13:46:00 -0400871 if (audit_sig_sid)
872 security_release_secctx(ctx, len);
Al Viroe1396062006-05-25 10:19:47 -0400873 return -ENOMEM;
874 }
875 sig_data->uid = audit_sig_uid;
876 sig_data->pid = audit_sig_pid;
Eric Paris939cbf22009-09-23 13:46:00 -0400877 if (audit_sig_sid) {
878 memcpy(sig_data->ctx, ctx, len);
879 security_release_secctx(ctx, len);
880 }
Daniel Walker5600b892007-10-18 03:06:10 -0700881 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
Al Viroe1396062006-05-25 10:19:47 -0400882 0, 0, sig_data, sizeof(*sig_data) + len);
883 kfree(sig_data);
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100884 break;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700885 case AUDIT_TTY_GET: {
886 struct audit_tty_status s;
887 struct task_struct *tsk;
Thomas Gleixnerab263f42009-12-09 14:19:41 +0000888 unsigned long flags;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700889
Thomas Gleixnerab263f42009-12-09 14:19:41 +0000890 rcu_read_lock();
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700891 tsk = find_task_by_vpid(pid);
Thomas Gleixnerab263f42009-12-09 14:19:41 +0000892 if (tsk && lock_task_sighand(tsk, &flags)) {
Miloslav Trmac522ed772007-07-15 23:40:56 -0700893 s.enabled = tsk->signal->audit_tty != 0;
Thomas Gleixnerab263f42009-12-09 14:19:41 +0000894 unlock_task_sighand(tsk, &flags);
895 } else
896 err = -ESRCH;
897 rcu_read_unlock();
Thomas Gleixner20703202009-12-09 14:19:35 +0000898
899 if (!err)
900 audit_send_reply(NETLINK_CB(skb).pid, seq,
901 AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
Miloslav Trmac522ed772007-07-15 23:40:56 -0700902 break;
903 }
904 case AUDIT_TTY_SET: {
905 struct audit_tty_status *s;
906 struct task_struct *tsk;
Thomas Gleixnerab263f42009-12-09 14:19:41 +0000907 unsigned long flags;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700908
909 if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
910 return -EINVAL;
911 s = data;
912 if (s->enabled != 0 && s->enabled != 1)
913 return -EINVAL;
Thomas Gleixnerab263f42009-12-09 14:19:41 +0000914 rcu_read_lock();
Pavel Emelyanov4a761b82008-04-18 13:30:15 -0700915 tsk = find_task_by_vpid(pid);
Thomas Gleixnerab263f42009-12-09 14:19:41 +0000916 if (tsk && lock_task_sighand(tsk, &flags)) {
Miloslav Trmac522ed772007-07-15 23:40:56 -0700917 tsk->signal->audit_tty = s->enabled != 0;
Thomas Gleixnerab263f42009-12-09 14:19:41 +0000918 unlock_task_sighand(tsk, &flags);
919 } else
920 err = -ESRCH;
921 rcu_read_unlock();
Miloslav Trmac522ed772007-07-15 23:40:56 -0700922 break;
923 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 default:
925 err = -EINVAL;
926 break;
927 }
928
929 return err < 0 ? err : 0;
930}
931
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700932/*
Eric Parisea7ae602009-06-11 14:31:35 -0400933 * Get message from skb. Each message is processed by audit_receive_msg.
934 * Malformed skbs with wrong length are discarded silently.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700935 */
Herbert Xu2a0a6eb2005-05-03 14:55:09 -0700936static void audit_receive_skb(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937{
Eric Parisea7ae602009-06-11 14:31:35 -0400938 struct nlmsghdr *nlh;
939 /*
940 * len MUST be signed for NLMSG_NEXT to be able to dec it below 0
941 * if the nlmsg_len was not aligned
942 */
943 int len;
944 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945
Eric Parisea7ae602009-06-11 14:31:35 -0400946 nlh = nlmsg_hdr(skb);
947 len = skb->len;
948
949 while (NLMSG_OK(nlh, len)) {
950 err = audit_receive_msg(skb, nlh);
951 /* if err or if this message says it wants a response */
952 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 netlink_ack(skb, nlh, err);
Eric Parisea7ae602009-06-11 14:31:35 -0400954
955 nlh = NLMSG_NEXT(nlh, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957}
958
959/* Receive messages from netlink socket. */
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700960static void audit_receive(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400962 mutex_lock(&audit_cmd_mutex);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700963 audit_receive_skb(skb);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400964 mutex_unlock(&audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965}
966
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967/* Initialize audit support at boot time. */
968static int __init audit_init(void)
969{
Amy Griffisf368c07d2006-04-07 16:55:56 -0400970 int i;
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +0000971 struct netlink_kernel_cfg cfg = {
972 .input = audit_receive,
973 };
Amy Griffisf368c07d2006-04-07 16:55:56 -0400974
Eric Parisa3f07112008-11-05 12:47:09 -0500975 if (audit_initialized == AUDIT_DISABLED)
976 return 0;
977
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
979 audit_default ? "enabled" : "disabled");
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +0000980 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT,
981 THIS_MODULE, &cfg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 if (!audit_sock)
983 audit_panic("cannot initialize netlink socket");
Amy Griffis71e1c782006-03-06 22:40:05 -0500984 else
985 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986
David Woodhouseb7d11252005-05-19 10:56:58 +0100987 skb_queue_head_init(&audit_skb_queue);
Eric Parisf3d357b2008-04-18 10:02:28 -0400988 skb_queue_head_init(&audit_skb_hold_queue);
Eric Parisa3f07112008-11-05 12:47:09 -0500989 audit_initialized = AUDIT_INITIALIZED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -0500991 audit_ever_enabled |= !!audit_default;
Darrel Goeddel3dc7e312006-03-10 18:14:06 -0600992
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100993 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
Amy Griffisf368c07d2006-04-07 16:55:56 -0400994
Amy Griffisf368c07d2006-04-07 16:55:56 -0400995 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
996 INIT_LIST_HEAD(&audit_inode_hash[i]);
Amy Griffisf368c07d2006-04-07 16:55:56 -0400997
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 return 0;
999}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000__initcall(audit_init);
1001
1002/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1003static int __init audit_enable(char *str)
1004{
1005 audit_default = !!simple_strtol(str, NULL, 0);
Eric Parisa3f07112008-11-05 12:47:09 -05001006 if (!audit_default)
1007 audit_initialized = AUDIT_DISABLED;
1008
1009 printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
1010
1011 if (audit_initialized == AUDIT_INITIALIZED) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 audit_enabled = audit_default;
Eric Parisb593d382008-01-08 17:38:31 -05001013 audit_ever_enabled |= !!audit_default;
Eric Parisa3f07112008-11-05 12:47:09 -05001014 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
1015 printk(" (after initialization)");
1016 } else {
1017 printk(" (until reboot)");
Eric Parisb593d382008-01-08 17:38:31 -05001018 }
Eric Parisa3f07112008-11-05 12:47:09 -05001019 printk("\n");
1020
OGAWA Hirofumi9b410462006-03-31 02:30:33 -08001021 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022}
1023
1024__setup("audit=", audit_enable);
1025
Chris Wright16e19042005-05-06 15:53:34 +01001026static void audit_buffer_free(struct audit_buffer *ab)
1027{
1028 unsigned long flags;
1029
Chris Wright8fc61152005-05-06 15:54:17 +01001030 if (!ab)
1031 return;
1032
Chris Wright5ac52f32005-05-06 15:54:53 +01001033 if (ab->skb)
1034 kfree_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001035
Chris Wright16e19042005-05-06 15:53:34 +01001036 spin_lock_irqsave(&audit_freelist_lock, flags);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001037 if (audit_freelist_count > AUDIT_MAXFREE)
Chris Wright16e19042005-05-06 15:53:34 +01001038 kfree(ab);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001039 else {
1040 audit_freelist_count++;
Chris Wright16e19042005-05-06 15:53:34 +01001041 list_add(&ab->list, &audit_freelist);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001042 }
Chris Wright16e19042005-05-06 15:53:34 +01001043 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1044}
1045
Steve Grubbc0404992005-05-13 18:17:42 +01001046static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
Al Virodd0fc662005-10-07 07:46:04 +01001047 gfp_t gfp_mask, int type)
Chris Wright16e19042005-05-06 15:53:34 +01001048{
1049 unsigned long flags;
1050 struct audit_buffer *ab = NULL;
Steve Grubbc0404992005-05-13 18:17:42 +01001051 struct nlmsghdr *nlh;
Chris Wright16e19042005-05-06 15:53:34 +01001052
1053 spin_lock_irqsave(&audit_freelist_lock, flags);
1054 if (!list_empty(&audit_freelist)) {
1055 ab = list_entry(audit_freelist.next,
1056 struct audit_buffer, list);
1057 list_del(&ab->list);
1058 --audit_freelist_count;
1059 }
1060 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1061
1062 if (!ab) {
David Woodhouse4332bdd2005-05-06 15:59:57 +01001063 ab = kmalloc(sizeof(*ab), gfp_mask);
Chris Wright16e19042005-05-06 15:53:34 +01001064 if (!ab)
Chris Wright8fc61152005-05-06 15:54:17 +01001065 goto err;
Chris Wright16e19042005-05-06 15:53:34 +01001066 }
Chris Wright8fc61152005-05-06 15:54:17 +01001067
David Woodhouseb7d11252005-05-19 10:56:58 +01001068 ab->ctx = ctx;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001069 ab->gfp_mask = gfp_mask;
Eric Parisee080e62009-06-11 14:31:35 -04001070
1071 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1072 if (!ab->skb)
David S. Millerc64e66c2012-06-26 21:45:21 -07001073 goto err;
Eric Parisee080e62009-06-11 14:31:35 -04001074
David S. Millerc64e66c2012-06-26 21:45:21 -07001075 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1076 if (!nlh)
1077 goto out_kfree_skb;
Eric Parisee080e62009-06-11 14:31:35 -04001078
Chris Wright16e19042005-05-06 15:53:34 +01001079 return ab;
Eric Parisee080e62009-06-11 14:31:35 -04001080
David S. Millerc64e66c2012-06-26 21:45:21 -07001081out_kfree_skb:
Eric Parisee080e62009-06-11 14:31:35 -04001082 kfree_skb(ab->skb);
1083 ab->skb = NULL;
Chris Wright8fc61152005-05-06 15:54:17 +01001084err:
1085 audit_buffer_free(ab);
1086 return NULL;
Chris Wright16e19042005-05-06 15:53:34 +01001087}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001089/**
1090 * audit_serial - compute a serial number for the audit record
1091 *
1092 * Compute a serial number for the audit record. Audit records are
David Woodhousebfb44962005-05-21 21:08:09 +01001093 * written to user-space as soon as they are generated, so a complete
1094 * audit record may be written in several pieces. The timestamp of the
1095 * record and this serial number are used by the user-space tools to
1096 * determine which pieces belong to the same audit record. The
1097 * (timestamp,serial) tuple is unique for each syscall and is live from
1098 * syscall entry to syscall exit.
1099 *
David Woodhousebfb44962005-05-21 21:08:09 +01001100 * NOTE: Another possibility is to store the formatted records off the
1101 * audit context (for those records that have a context), and emit them
1102 * all at syscall exit. However, this could delay the reporting of
1103 * significant errors until syscall exit (or never, if the system
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001104 * halts).
1105 */
David Woodhousebfb44962005-05-21 21:08:09 +01001106unsigned int audit_serial(void)
1107{
Ingo Molnar34af9462006-06-27 02:53:55 -07001108 static DEFINE_SPINLOCK(serial_lock);
David Woodhoused5b454f2005-07-15 12:56:03 +01001109 static unsigned int serial = 0;
David Woodhousebfb44962005-05-21 21:08:09 +01001110
David Woodhoused5b454f2005-07-15 12:56:03 +01001111 unsigned long flags;
1112 unsigned int ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001113
David Woodhoused5b454f2005-07-15 12:56:03 +01001114 spin_lock_irqsave(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001115 do {
David Woodhousece625a82005-07-18 14:24:46 -04001116 ret = ++serial;
1117 } while (unlikely(!ret));
David Woodhoused5b454f2005-07-15 12:56:03 +01001118 spin_unlock_irqrestore(&serial_lock, flags);
David Woodhousebfb44962005-05-21 21:08:09 +01001119
David Woodhoused5b454f2005-07-15 12:56:03 +01001120 return ret;
David Woodhousebfb44962005-05-21 21:08:09 +01001121}
1122
Daniel Walker5600b892007-10-18 03:06:10 -07001123static inline void audit_get_stamp(struct audit_context *ctx,
David Woodhousebfb44962005-05-21 21:08:09 +01001124 struct timespec *t, unsigned int *serial)
1125{
Al Viro48887e62008-12-06 01:05:50 -05001126 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
David Woodhousebfb44962005-05-21 21:08:09 +01001127 *t = CURRENT_TIME;
1128 *serial = audit_serial();
1129 }
1130}
1131
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132/* Obtain an audit buffer. This routine does locking to obtain the
1133 * audit buffer, but then no locking is required for calls to
1134 * audit_log_*format. If the tsk is a task that is currently in a
1135 * syscall, then the syscall is marked as auditable and an audit record
1136 * will be written at syscall exit. If there is no associated task, tsk
1137 * should be NULL. */
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001138
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001139/**
1140 * audit_log_start - obtain an audit buffer
1141 * @ctx: audit_context (may be NULL)
1142 * @gfp_mask: type of allocation
1143 * @type: audit message type
1144 *
1145 * Returns audit_buffer pointer on success or NULL on error.
1146 *
1147 * Obtain an audit buffer. This routine does locking to obtain the
1148 * audit buffer, but then no locking is required for calls to
1149 * audit_log_*format. If the task (ctx) is a task that is currently in a
1150 * syscall, then the syscall is marked as auditable and an audit record
1151 * will be written at syscall exit. If there is no associated task, then
1152 * task context (ctx) should be NULL.
1153 */
Al Viro9796fdd2005-10-21 03:22:03 -04001154struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001155 int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156{
1157 struct audit_buffer *ab = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 struct timespec t;
Andrew Mortonef00be02008-01-10 11:02:39 -08001159 unsigned int uninitialized_var(serial);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001160 int reserve;
David Woodhouseac4cec42005-07-02 14:08:48 +01001161 unsigned long timeout_start = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162
Eric Parisa3f07112008-11-05 12:47:09 -05001163 if (audit_initialized != AUDIT_INITIALIZED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 return NULL;
1165
Dustin Kirklandc8edc802005-11-03 16:12:36 +00001166 if (unlikely(audit_filter_type(type)))
1167 return NULL;
1168
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001169 if (gfp_mask & __GFP_WAIT)
1170 reserve = 0;
1171 else
Daniel Walker5600b892007-10-18 03:06:10 -07001172 reserve = 5; /* Allow atomic callers to go up to five
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001173 entries over the normal backlog limit */
1174
1175 while (audit_backlog_limit
1176 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
David Woodhouseac4cec42005-07-02 14:08:48 +01001177 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
1178 && time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
1179
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001180 /* Wait for auditd to drain the queue a little */
1181 DECLARE_WAITQUEUE(wait, current);
1182 set_current_state(TASK_INTERRUPTIBLE);
1183 add_wait_queue(&audit_backlog_wait, &wait);
1184
1185 if (audit_backlog_limit &&
1186 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
David Woodhouseac4cec42005-07-02 14:08:48 +01001187 schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001188
1189 __set_current_state(TASK_RUNNING);
1190 remove_wait_queue(&audit_backlog_wait, &wait);
David Woodhouseac4cec42005-07-02 14:08:48 +01001191 continue;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001192 }
Eric Paris320f1b12008-01-23 22:55:05 -05001193 if (audit_rate_check() && printk_ratelimit())
David Woodhousefb19b4c2005-05-19 14:55:56 +01001194 printk(KERN_WARNING
1195 "audit: audit_backlog=%d > "
1196 "audit_backlog_limit=%d\n",
1197 skb_queue_len(&audit_skb_queue),
1198 audit_backlog_limit);
1199 audit_log_lost("backlog limit exceeded");
David Woodhouseac4cec42005-07-02 14:08:48 +01001200 audit_backlog_wait_time = audit_backlog_wait_overflow;
1201 wake_up(&audit_backlog_wait);
David Woodhousefb19b4c2005-05-19 14:55:56 +01001202 return NULL;
1203 }
1204
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001205 ab = audit_buffer_alloc(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 if (!ab) {
1207 audit_log_lost("out of memory in audit_log_start");
1208 return NULL;
1209 }
1210
David Woodhousebfb44962005-05-21 21:08:09 +01001211 audit_get_stamp(ab->ctx, &t, &serial);
Chris Wright197c69c2005-05-11 10:54:05 +01001212
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1214 t.tv_sec, t.tv_nsec/1000000, serial);
1215 return ab;
1216}
1217
Chris Wright8fc61152005-05-06 15:54:17 +01001218/**
Chris Wright5ac52f32005-05-06 15:54:53 +01001219 * audit_expand - expand skb in the audit buffer
Chris Wright8fc61152005-05-06 15:54:17 +01001220 * @ab: audit_buffer
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001221 * @extra: space to add at tail of the skb
Chris Wright8fc61152005-05-06 15:54:17 +01001222 *
1223 * Returns 0 (no space) on failed expansion, or available space if
1224 * successful.
1225 */
David Woodhousee3b926b2005-05-10 18:56:08 +01001226static inline int audit_expand(struct audit_buffer *ab, int extra)
Chris Wright8fc61152005-05-06 15:54:17 +01001227{
Chris Wright5ac52f32005-05-06 15:54:53 +01001228 struct sk_buff *skb = ab->skb;
Herbert Xu406a1d82008-01-28 20:47:09 -08001229 int oldtail = skb_tailroom(skb);
1230 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1231 int newtail = skb_tailroom(skb);
1232
Chris Wright5ac52f32005-05-06 15:54:53 +01001233 if (ret < 0) {
1234 audit_log_lost("out of memory in audit_expand");
Chris Wright8fc61152005-05-06 15:54:17 +01001235 return 0;
Chris Wright5ac52f32005-05-06 15:54:53 +01001236 }
Herbert Xu406a1d82008-01-28 20:47:09 -08001237
1238 skb->truesize += newtail - oldtail;
1239 return newtail;
Chris Wright8fc61152005-05-06 15:54:17 +01001240}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001242/*
1243 * Format an audit message into the audit buffer. If there isn't enough
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 * room in the audit buffer, more room will be allocated and vsnprint
1245 * will be called a second time. Currently, we assume that a printk
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001246 * can't format message larger than 1024 bytes, so we don't either.
1247 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001248static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1249 va_list args)
1250{
1251 int len, avail;
Chris Wright5ac52f32005-05-06 15:54:53 +01001252 struct sk_buff *skb;
David Woodhouseeecb0a72005-05-10 18:58:51 +01001253 va_list args2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254
1255 if (!ab)
1256 return;
1257
Chris Wright5ac52f32005-05-06 15:54:53 +01001258 BUG_ON(!ab->skb);
1259 skb = ab->skb;
1260 avail = skb_tailroom(skb);
1261 if (avail == 0) {
David Woodhousee3b926b2005-05-10 18:56:08 +01001262 avail = audit_expand(ab, AUDIT_BUFSIZ);
Chris Wright8fc61152005-05-06 15:54:17 +01001263 if (!avail)
1264 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265 }
David Woodhouseeecb0a72005-05-10 18:58:51 +01001266 va_copy(args2, args);
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001267 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268 if (len >= avail) {
1269 /* The printk buffer is 1024 bytes long, so if we get
1270 * here and AUDIT_BUFSIZ is at least 1024, then we can
1271 * log everything that printk could have logged. */
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001272 avail = audit_expand(ab,
1273 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
Chris Wright8fc61152005-05-06 15:54:17 +01001274 if (!avail)
Jesper Juhla0e86bd2012-01-08 22:44:29 +01001275 goto out_va_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001276 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277 }
Steve Grubb168b7172005-05-19 10:24:22 +01001278 if (len > 0)
1279 skb_put(skb, len);
Jesper Juhla0e86bd2012-01-08 22:44:29 +01001280out_va_end:
1281 va_end(args2);
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,
Al Viro66b3fad2012-03-14 21:48:20 -04001433 const 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)
Kees Cookc158a352012-01-06 14:07:10 -08001438 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
Eric Paris9d960982009-06-11 14:31:37 -04001455void audit_log_key(struct audit_buffer *ab, char *key)
1456{
1457 audit_log_format(ab, " key=");
1458 if (key)
1459 audit_log_untrustedstring(ab, key);
1460 else
1461 audit_log_format(ab, "(null)");
1462}
1463
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001464/**
Kees Cooka51d9ea2012-07-25 17:29:08 -07001465 * audit_log_link_denied - report a link restriction denial
1466 * @operation: specific link opreation
1467 * @link: the path that triggered the restriction
1468 */
1469void audit_log_link_denied(const char *operation, struct path *link)
1470{
1471 struct audit_buffer *ab;
1472
1473 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1474 AUDIT_ANOM_LINK);
1475 audit_log_format(ab, "op=%s action=denied", operation);
1476 audit_log_format(ab, " pid=%d comm=", current->pid);
1477 audit_log_untrustedstring(ab, current->comm);
1478 audit_log_d_path(ab, " path=", link);
1479 audit_log_format(ab, " dev=");
1480 audit_log_untrustedstring(ab, link->dentry->d_inode->i_sb->s_id);
1481 audit_log_format(ab, " ino=%lu", link->dentry->d_inode->i_ino);
1482 audit_log_end(ab);
1483}
1484
1485/**
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001486 * audit_log_end - end one audit record
1487 * @ab: the audit_buffer
1488 *
1489 * The netlink_* functions cannot be called inside an irq context, so
1490 * the audit buffer is placed on a queue and a tasklet is scheduled to
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491 * remove them from the queue outside the irq context. May be called in
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001492 * any context.
1493 */
David Woodhouseb7d11252005-05-19 10:56:58 +01001494void audit_log_end(struct audit_buffer *ab)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001496 if (!ab)
1497 return;
1498 if (!audit_rate_check()) {
1499 audit_log_lost("rate limit exceeded");
1500 } else {
Steve Grubb8d07a672008-02-21 16:59:22 -05001501 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
Eric Parisf3d357b2008-04-18 10:02:28 -04001502 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
1503
David Woodhouseb7d11252005-05-19 10:56:58 +01001504 if (audit_pid) {
David Woodhouseb7d11252005-05-19 10:56:58 +01001505 skb_queue_tail(&audit_skb_queue, ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001506 wake_up_interruptible(&kauditd_wait);
Eric Parisf3d357b2008-04-18 10:02:28 -04001507 } else {
Eric Paris038cbcf2009-06-11 14:31:35 -04001508 audit_printk_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01001509 }
Eric Parisf3d357b2008-04-18 10:02:28 -04001510 ab->skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 }
Chris Wright16e19042005-05-06 15:53:34 +01001512 audit_buffer_free(ab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513}
1514
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001515/**
1516 * audit_log - Log an audit record
1517 * @ctx: audit context
1518 * @gfp_mask: type of allocation
1519 * @type: audit message type
1520 * @fmt: format string to use
1521 * @...: variable parameters matching the format string
1522 *
1523 * This is a convenience function that calls audit_log_start,
1524 * audit_log_vformat, and audit_log_end. It may be called
1525 * in any context.
1526 */
Daniel Walker5600b892007-10-18 03:06:10 -07001527void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001528 const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529{
1530 struct audit_buffer *ab;
1531 va_list args;
1532
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001533 ab = audit_log_start(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001534 if (ab) {
1535 va_start(args, fmt);
1536 audit_log_vformat(ab, fmt, args);
1537 va_end(args);
1538 audit_log_end(ab);
1539 }
1540}
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01001541
Mr Dash Four131ad622011-06-30 13:31:57 +02001542#ifdef CONFIG_SECURITY
1543/**
1544 * audit_log_secctx - Converts and logs SELinux context
1545 * @ab: audit_buffer
1546 * @secid: security number
1547 *
1548 * This is a helper function that calls security_secid_to_secctx to convert
1549 * secid to secctx and then adds the (converted) SELinux context to the audit
1550 * log by calling audit_log_format, thus also preventing leak of internal secid
1551 * to userspace. If secid cannot be converted audit_panic is called.
1552 */
1553void audit_log_secctx(struct audit_buffer *ab, u32 secid)
1554{
1555 u32 len;
1556 char *secctx;
1557
1558 if (security_secid_to_secctx(secid, &secctx, &len)) {
1559 audit_panic("Cannot convert secid to context");
1560 } else {
1561 audit_log_format(ab, " obj=%s", secctx);
1562 security_release_secctx(secctx, len);
1563 }
1564}
1565EXPORT_SYMBOL(audit_log_secctx);
1566#endif
1567
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01001568EXPORT_SYMBOL(audit_log_start);
1569EXPORT_SYMBOL(audit_log_end);
1570EXPORT_SYMBOL(audit_log_format);
1571EXPORT_SYMBOL(audit_log);