blob: 8660712ef6322617cf5837cbc614cafd86590579 [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
Joe Perchesd957f7b2014-01-14 10:33:12 -080044#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
45
Davidlohr Bueso5b282552015-02-22 18:20:09 -080046#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/init.h>
Paul McQuade7153e402014-06-06 14:37:37 -070048#include <linux/types.h>
Arun Sharma600634972011-07-26 16:09:06 -070049#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#include <linux/mm.h>
Paul Gortmaker9984de12011-05-23 14:51:41 -040051#include <linux/export.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090052#include <linux/slab.h>
David Woodhouseb7d11252005-05-19 10:56:58 +010053#include <linux/err.h>
54#include <linux/kthread.h>
Richard Guy Briggs46e959e2013-05-03 14:03:50 -040055#include <linux/kernel.h>
Eric Parisb24a30a2013-04-30 15:30:32 -040056#include <linux/syscalls.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58#include <linux/audit.h>
59
60#include <net/sock.h>
Amy Griffis93315ed2006-02-07 12:05:27 -050061#include <net/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070062#include <linux/skbuff.h>
Mr Dash Four131ad622011-06-30 13:31:57 +020063#ifdef CONFIG_SECURITY
64#include <linux/security.h>
65#endif
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080066#include <linux/freezer.h>
Eric W. Biederman34e36d82012-09-10 23:20:20 -070067#include <linux/pid_namespace.h>
Richard Guy Briggs33faba72013-07-16 13:18:45 -040068#include <net/netns/generic.h>
Darrel Goeddel3dc7e312006-03-10 18:14:06 -060069
70#include "audit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
Eric Parisa3f07112008-11-05 12:47:09 -050072/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 * (Initialization happens after skb_init is called.) */
Eric Parisa3f07112008-11-05 12:47:09 -050074#define AUDIT_DISABLED -1
75#define AUDIT_UNINITIALIZED 0
76#define AUDIT_INITIALIZED 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070077static int audit_initialized;
78
Eric Paris1a6b9f22008-01-07 17:09:31 -050079#define AUDIT_OFF 0
80#define AUDIT_ON 1
81#define AUDIT_LOCKED 2
Paul Moore93dedcf2017-09-01 09:44:34 -040082u32 audit_enabled = AUDIT_OFF;
83u32 audit_ever_enabled = !!AUDIT_OFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Jan Engelhardtae9d67af2011-01-18 06:48:12 +010085EXPORT_SYMBOL_GPL(audit_enabled);
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087/* Default state when kernel boots without any parameters. */
Paul Moore93dedcf2017-09-01 09:44:34 -040088static u32 audit_default = AUDIT_OFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
90/* If auditing cannot proceed, audit_failure selects what happens. */
Joe Perches3e1d0bb2014-01-14 10:33:13 -080091static u32 audit_failure = AUDIT_FAIL_PRINTK;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
Pavel Emelyanov75c03712008-03-20 15:39:41 -070093/*
94 * If audit records are to be written to the netlink socket, audit_pid
Eric W. Biederman15e47302012-09-07 20:12:54 +000095 * contains the pid of the auditd process and audit_nlk_portid contains
96 * the portid to use to send netlink messages to that process.
Pavel Emelyanov75c03712008-03-20 15:39:41 -070097 */
Steve Grubbc2f0c7c2005-05-06 12:38:39 +010098int audit_pid;
Richard Guy Briggsf9441632013-08-14 11:32:45 -040099static __u32 audit_nlk_portid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700101/* If audit_rate_limit is non-zero, limit the rate of sending audit records
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 * to that number per second. This prevents DoS attacks, but results in
103 * audit records being dropped. */
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800104static u32 audit_rate_limit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
Richard Guy Briggs40c07752013-10-22 13:28:49 -0400106/* Number of outstanding audit_buffers allowed.
107 * When set to zero, this means unlimited. */
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800108static u32 audit_backlog_limit = 64;
Richard Guy Briggse789e562013-09-12 23:03:51 -0400109#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
Richard Guy Briggsa77ed4e2015-02-23 15:37:59 -0500110static u32 audit_backlog_wait_time_master = AUDIT_BACKLOG_WAIT_TIME;
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800111static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100113/* The identity of the user shutting down the audit system. */
Eric W. Biedermancca080d2012-02-07 16:53:48 -0800114kuid_t audit_sig_uid = INVALID_UID;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100115pid_t audit_sig_pid = -1;
Al Viroe1396062006-05-25 10:19:47 -0400116u32 audit_sig_sid = 0;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118/* Records can be lost in several ways:
119 0) [suppressed in audit_alloc]
120 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
121 2) out of memory in audit_log_move [alloc_skb]
122 3) suppressed due to audit_rate_limit
123 4) suppressed due to audit_backlog_limit
124*/
125static atomic_t audit_lost = ATOMIC_INIT(0);
126
127/* The netlink socket. */
Teng Fei Fana4f13562018-10-15 14:02:39 +0800128static DEFINE_MUTEX(audit_sock_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129static struct sock *audit_sock;
Richard Guy Briggsc0a8d9b2014-05-26 10:59:28 -0400130static int audit_net_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
Amy Griffisf368c07d2006-04-07 16:55:56 -0400132/* Hash for inode-based rules */
133struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
134
David Woodhouseb7d11252005-05-19 10:56:58 +0100135/* The audit_freelist is a list of pre-allocated audit buffers (if more
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
137 * being placed on the freelist). */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138static DEFINE_SPINLOCK(audit_freelist_lock);
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700139static int audit_freelist_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140static LIST_HEAD(audit_freelist);
141
David Woodhouseb7d11252005-05-19 10:56:58 +0100142static struct sk_buff_head audit_skb_queue;
Eric Parisf3d357b2008-04-18 10:02:28 -0400143/* queue of skbs to send to auditd when/if it comes back */
144static struct sk_buff_head audit_skb_hold_queue;
David Woodhouseb7d11252005-05-19 10:56:58 +0100145static struct task_struct *kauditd_task;
146static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100147static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Eric Parisb0fed402013-05-22 12:54:49 -0400149static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
150 .mask = -1,
151 .features = 0,
152 .lock = 0,};
153
Eric Paris21b85c32013-05-23 14:26:00 -0400154static char *audit_feature_names[2] = {
Eric Parisd040e5a2013-05-24 09:18:04 -0400155 "only_unset_loginuid",
Eric Paris21b85c32013-05-23 14:26:00 -0400156 "loginuid_immutable",
Eric Parisb0fed402013-05-22 12:54:49 -0400157};
158
159
Amy Griffisf368c07d2006-04-07 16:55:56 -0400160/* Serialize requests from userspace. */
Al Viro916d7572009-06-24 00:02:38 -0400161DEFINE_MUTEX(audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
164 * audit records. Since printk uses a 1024 byte buffer, this buffer
165 * should be at least that large. */
166#define AUDIT_BUFSIZ 1024
167
168/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
169 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
170#define AUDIT_MAXFREE (2*NR_CPUS)
171
172/* The audit_buffer is used when formatting an audit record. The caller
173 * locks briefly to get the record off the freelist or to allocate the
174 * buffer, and locks briefly to send the buffer to the netlink layer or
175 * to place it on a transmit queue. Multiple audit_buffers can be in
176 * use simultaneously. */
177struct audit_buffer {
178 struct list_head list;
Chris Wright8fc61152005-05-06 15:54:17 +0100179 struct sk_buff *skb; /* formatted skb ready to send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 struct audit_context *ctx; /* NULL or associated context */
Al Viro9796fdd2005-10-21 03:22:03 -0400181 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182};
183
Eric Parisf09ac9d2008-04-18 10:11:04 -0400184struct audit_reply {
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400185 __u32 portid;
Eric W. Biederman638a0fd2014-02-28 10:49:05 -0800186 struct net *net;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400187 struct sk_buff *skb;
188};
189
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400190static void audit_set_portid(struct audit_buffer *ab, __u32 portid)
Steve Grubbc0404992005-05-13 18:17:42 +0100191{
Eric Paris50397bd2008-01-07 18:14:19 -0500192 if (ab) {
193 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400194 nlh->nlmsg_pid = portid;
Eric Paris50397bd2008-01-07 18:14:19 -0500195 }
Steve Grubbc0404992005-05-13 18:17:42 +0100196}
197
Dustin Kirkland8c8570f2005-11-03 17:15:16 +0000198void audit_panic(const char *message)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199{
Joe Perchesd957f7b2014-01-14 10:33:12 -0800200 switch (audit_failure) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 case AUDIT_FAIL_SILENT:
202 break;
203 case AUDIT_FAIL_PRINTK:
Eric Paris320f1b12008-01-23 22:55:05 -0500204 if (printk_ratelimit())
Joe Perchesd957f7b2014-01-14 10:33:12 -0800205 pr_err("%s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 break;
207 case AUDIT_FAIL_PANIC:
Eric Parisb29ee872008-02-21 15:53:05 -0500208 /* test audit_pid since printk is always losey, why bother? */
209 if (audit_pid)
210 panic("audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 break;
212 }
213}
214
215static inline int audit_rate_check(void)
216{
217 static unsigned long last_check = 0;
218 static int messages = 0;
219 static DEFINE_SPINLOCK(lock);
220 unsigned long flags;
221 unsigned long now;
222 unsigned long elapsed;
223 int retval = 0;
224
225 if (!audit_rate_limit) return 1;
226
227 spin_lock_irqsave(&lock, flags);
228 if (++messages < audit_rate_limit) {
229 retval = 1;
230 } else {
231 now = jiffies;
232 elapsed = now - last_check;
233 if (elapsed > HZ) {
234 last_check = now;
235 messages = 0;
236 retval = 1;
237 }
238 }
239 spin_unlock_irqrestore(&lock, flags);
240
241 return retval;
242}
243
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700244/**
245 * audit_log_lost - conditionally log lost audit message event
246 * @message: the message stating reason for lost audit message
247 *
248 * Emit at least 1 message per second, even if audit_rate_check is
249 * throttling.
250 * Always increment the lost messages counter.
251*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252void audit_log_lost(const char *message)
253{
254 static unsigned long last_msg = 0;
255 static DEFINE_SPINLOCK(lock);
256 unsigned long flags;
257 unsigned long now;
258 int print;
259
260 atomic_inc(&audit_lost);
261
262 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
263
264 if (!print) {
265 spin_lock_irqsave(&lock, flags);
266 now = jiffies;
267 if (now - last_msg > HZ) {
268 print = 1;
269 last_msg = now;
270 }
271 spin_unlock_irqrestore(&lock, flags);
272 }
273
274 if (print) {
Eric Paris320f1b12008-01-23 22:55:05 -0500275 if (printk_ratelimit())
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800276 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
Eric Paris320f1b12008-01-23 22:55:05 -0500277 atomic_read(&audit_lost),
278 audit_rate_limit,
279 audit_backlog_limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 audit_panic(message);
281 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282}
283
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800284static int audit_log_config_change(char *function_name, u32 new, u32 old,
Eric Paris25323862008-04-18 10:09:25 -0400285 int allow_changes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500287 struct audit_buffer *ab;
288 int rc = 0;
Steve Grubb6a01b072007-01-19 14:39:55 -0500289
Eric Paris1a6b9f22008-01-07 17:09:31 -0500290 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
Kees Cook0644ec02013-01-11 14:32:07 -0800291 if (unlikely(!ab))
292 return rc;
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800293 audit_log_format(ab, "%s=%u old=%u", function_name, new, old);
Eric Paris4d3fb702013-04-30 09:53:34 -0400294 audit_log_session_info(ab);
Eric Parisb122c372013-04-19 15:00:33 -0400295 rc = audit_log_task_context(ab);
296 if (rc)
297 allow_changes = 0; /* Something weird, deny request */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500298 audit_log_format(ab, " res=%d", allow_changes);
299 audit_log_end(ab);
300 return rc;
301}
302
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800303static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500304{
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800305 int allow_changes, rc = 0;
306 u32 old = *to_change;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500307
308 /* check if we are locked */
309 if (audit_enabled == AUDIT_LOCKED)
310 allow_changes = 0;
311 else
312 allow_changes = 1;
313
314 if (audit_enabled != AUDIT_OFF) {
Eric Parisdc9eb692013-04-19 13:23:09 -0400315 rc = audit_log_config_change(function_name, new, old, allow_changes);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500316 if (rc)
317 allow_changes = 0;
318 }
Steve Grubb6a01b072007-01-19 14:39:55 -0500319
320 /* If we are allowed, make the change */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500321 if (allow_changes == 1)
322 *to_change = new;
Steve Grubb6a01b072007-01-19 14:39:55 -0500323 /* Not allowed, update reason */
324 else if (rc == 0)
325 rc = -EPERM;
326 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327}
328
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800329static int audit_set_rate_limit(u32 limit)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500330{
Eric Parisdc9eb692013-04-19 13:23:09 -0400331 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500332}
333
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800334static int audit_set_backlog_limit(u32 limit)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335{
Eric Parisdc9eb692013-04-19 13:23:09 -0400336 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337}
338
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800339static int audit_set_backlog_wait_time(u32 timeout)
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -0400340{
341 return audit_do_config_change("audit_backlog_wait_time",
Richard Guy Briggsa77ed4e2015-02-23 15:37:59 -0500342 &audit_backlog_wait_time_master, timeout);
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -0400343}
344
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800345static int audit_set_enabled(u32 state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346{
Eric Parisb593d382008-01-08 17:38:31 -0500347 int rc;
Pranith Kumar724e7bf2015-03-11 14:08:19 -0400348 if (state > AUDIT_LOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500350
Eric Parisdc9eb692013-04-19 13:23:09 -0400351 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
Eric Parisb593d382008-01-08 17:38:31 -0500352 if (!rc)
353 audit_ever_enabled |= !!state;
354
355 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356}
357
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800358static int audit_set_failure(u32 state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 if (state != AUDIT_FAIL_SILENT
361 && state != AUDIT_FAIL_PRINTK
362 && state != AUDIT_FAIL_PANIC)
363 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500364
Eric Parisdc9eb692013-04-19 13:23:09 -0400365 return audit_do_config_change("audit_failure", &audit_failure, state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366}
367
Eric Parisf3d357b2008-04-18 10:02:28 -0400368/*
369 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
370 * already have been sent via prink/syslog and so if these messages are dropped
371 * it is not a huge concern since we already passed the audit_log_lost()
372 * notification and stuff. This is just nice to get audit messages during
373 * boot before auditd is running or messages generated while auditd is stopped.
374 * This only holds messages is audit_default is set, aka booting with audit=1
375 * or building your kernel that way.
376 */
377static void audit_hold_skb(struct sk_buff *skb)
378{
379 if (audit_default &&
Richard Guy Briggs40c07752013-10-22 13:28:49 -0400380 (!audit_backlog_limit ||
381 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit))
Eric Parisf3d357b2008-04-18 10:02:28 -0400382 skb_queue_tail(&audit_skb_hold_queue, skb);
383 else
384 kfree_skb(skb);
385}
386
Eric Paris038cbcf2009-06-11 14:31:35 -0400387/*
388 * For one reason or another this nlh isn't getting delivered to the userspace
389 * audit daemon, just send it to printk.
390 */
391static void audit_printk_skb(struct sk_buff *skb)
392{
393 struct nlmsghdr *nlh = nlmsg_hdr(skb);
David S. Millerc64e66c2012-06-26 21:45:21 -0700394 char *data = nlmsg_data(nlh);
Eric Paris038cbcf2009-06-11 14:31:35 -0400395
396 if (nlh->nlmsg_type != AUDIT_EOE) {
397 if (printk_ratelimit())
Joe Perchesd957f7b2014-01-14 10:33:12 -0800398 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
Eric Paris038cbcf2009-06-11 14:31:35 -0400399 else
Josh Boyerf1283522014-03-05 16:29:55 -0500400 audit_log_lost("printk limit exceeded");
Eric Paris038cbcf2009-06-11 14:31:35 -0400401 }
402
403 audit_hold_skb(skb);
404}
405
Eric Parisf3d357b2008-04-18 10:02:28 -0400406static void kauditd_send_skb(struct sk_buff *skb)
407{
408 int err;
Richard Guy Briggs32a1dba2015-11-04 08:23:50 -0500409 int attempts = 0;
410#define AUDITD_RETRIES 5
411
412restart:
Eric Parisf3d357b2008-04-18 10:02:28 -0400413 /* take a reference in case we can't send it and we want to hold it */
414 skb_get(skb);
Teng Fei Fana4f13562018-10-15 14:02:39 +0800415 mutex_lock(&audit_sock_mutex);
Eric W. Biederman15e47302012-09-07 20:12:54 +0000416 err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
Teng Fei Fana4f13562018-10-15 14:02:39 +0800417 mutex_unlock(&audit_sock_mutex);
Eric Parisf3d357b2008-04-18 10:02:28 -0400418 if (err < 0) {
Richard Guy Briggs32a1dba2015-11-04 08:23:50 -0500419 pr_err("netlink_unicast sending to audit_pid=%d returned error: %d\n",
420 audit_pid, err);
Richard Guy Briggs04ee1a32013-11-26 18:49:12 -0500421 if (audit_pid) {
Richard Guy Briggs32a1dba2015-11-04 08:23:50 -0500422 if (err == -ECONNREFUSED || err == -EPERM
423 || ++attempts >= AUDITD_RETRIES) {
424 char s[32];
425
426 snprintf(s, sizeof(s), "audit_pid=%d reset", audit_pid);
427 audit_log_lost(s);
428 audit_pid = 0;
Teng Fei Fana4f13562018-10-15 14:02:39 +0800429 mutex_lock(&audit_sock_mutex);
Richard Guy Briggs32a1dba2015-11-04 08:23:50 -0500430 audit_sock = NULL;
Teng Fei Fana4f13562018-10-15 14:02:39 +0800431 mutex_unlock(&audit_sock_mutex);
Richard Guy Briggs32a1dba2015-11-04 08:23:50 -0500432 } else {
433 pr_warn("re-scheduling(#%d) write to audit_pid=%d\n",
434 attempts, audit_pid);
435 set_current_state(TASK_INTERRUPTIBLE);
436 schedule();
Richard Guy Briggs32a1dba2015-11-04 08:23:50 -0500437 goto restart;
438 }
Richard Guy Briggs04ee1a32013-11-26 18:49:12 -0500439 }
Eric Parisf3d357b2008-04-18 10:02:28 -0400440 /* we might get lucky and get this in the next auditd */
441 audit_hold_skb(skb);
442 } else
443 /* drop the extra reference if sent ok */
Neil Horman70d4bf62010-07-20 06:45:56 +0000444 consume_skb(skb);
Eric Parisf3d357b2008-04-18 10:02:28 -0400445}
446
Richard Guy Briggsb551d1d2013-01-24 13:15:10 -0500447/*
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400448 * kauditd_send_multicast_skb - send the skb to multicast userspace listeners
449 *
450 * This function doesn't consume an skb as might be expected since it has to
451 * copy it anyways.
452 */
Richard Guy Briggs54dc77d2014-12-18 23:09:27 -0500453static void kauditd_send_multicast_skb(struct sk_buff *skb, gfp_t gfp_mask)
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400454{
455 struct sk_buff *copy;
456 struct audit_net *aunet = net_generic(&init_net, audit_net_id);
457 struct sock *sock = aunet->nlsk;
458
Richard Guy Briggs7f74ecd2014-04-22 21:31:58 -0400459 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
460 return;
461
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400462 /*
463 * The seemingly wasteful skb_copy() rather than bumping the refcount
464 * using skb_get() is necessary because non-standard mods are made to
465 * the skb by the original kaudit unicast socket send routine. The
466 * existing auditd daemon assumes this breakage. Fixing this would
467 * require co-ordinating a change in the established protocol between
468 * the kaudit kernel subsystem and the auditd userspace code. There is
469 * no reason for new multicast clients to continue with this
470 * non-compliance.
471 */
Richard Guy Briggs54dc77d2014-12-18 23:09:27 -0500472 copy = skb_copy(skb, gfp_mask);
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400473 if (!copy)
474 return;
475
Richard Guy Briggs54dc77d2014-12-18 23:09:27 -0500476 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, gfp_mask);
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400477}
478
479/*
Richard Guy Briggsb551d1d2013-01-24 13:15:10 -0500480 * flush_hold_queue - empty the hold queue if auditd appears
481 *
482 * If auditd just started, drain the queue of messages already
483 * sent to syslog/printk. Remember loss here is ok. We already
484 * called audit_log_lost() if it didn't go out normally. so the
485 * race between the skb_dequeue and the next check for audit_pid
486 * doesn't matter.
487 *
488 * If you ever find kauditd to be too slow we can get a perf win
489 * by doing our own locking and keeping better track if there
490 * are messages in this queue. I don't see the need now, but
491 * in 5 years when I want to play with this again I'll see this
492 * note and still have no friggin idea what i'm thinking today.
493 */
494static void flush_hold_queue(void)
David Woodhouseb7d11252005-05-19 10:56:58 +0100495{
496 struct sk_buff *skb;
497
Richard Guy Briggsb551d1d2013-01-24 13:15:10 -0500498 if (!audit_default || !audit_pid)
499 return;
500
501 skb = skb_dequeue(&audit_skb_hold_queue);
502 if (likely(!skb))
503 return;
504
505 while (skb && audit_pid) {
506 kauditd_send_skb(skb);
507 skb = skb_dequeue(&audit_skb_hold_queue);
508 }
509
510 /*
511 * if auditd just disappeared but we
512 * dequeued an skb we need to drop ref
513 */
Markus Elfringd865e572016-01-13 09:18:55 -0500514 consume_skb(skb);
Richard Guy Briggsb551d1d2013-01-24 13:15:10 -0500515}
516
David Woodhouseb7d11252005-05-19 10:56:58 +0100517static int kauditd_thread(void *dummy)
518{
Rafael J. Wysocki83144182007-07-17 04:03:35 -0700519 set_freezable();
Andrew Morton4899b8b2006-10-06 00:43:48 -0700520 while (!kthread_should_stop()) {
Richard Guy Briggs3320c512013-01-24 13:15:11 -0500521 struct sk_buff *skb;
Richard Guy Briggs3320c512013-01-24 13:15:11 -0500522
Richard Guy Briggsb551d1d2013-01-24 13:15:10 -0500523 flush_hold_queue();
Eric Parisf3d357b2008-04-18 10:02:28 -0400524
David Woodhouseb7d11252005-05-19 10:56:58 +0100525 skb = skb_dequeue(&audit_skb_queue);
Dan Duvaldb897312013-09-16 11:11:12 -0400526
David Woodhouseb7d11252005-05-19 10:56:58 +0100527 if (skb) {
Richard Guy Briggs1194b992016-01-13 09:18:54 -0500528 if (!audit_backlog_limit ||
529 (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit))
Dan Duvaldb897312013-09-16 11:11:12 -0400530 wake_up(&audit_backlog_wait);
Eric Parisf3d357b2008-04-18 10:02:28 -0400531 if (audit_pid)
532 kauditd_send_skb(skb);
Eric Paris038cbcf2009-06-11 14:31:35 -0400533 else
534 audit_printk_skb(skb);
Richard Guy Briggs3320c512013-01-24 13:15:11 -0500535 continue;
David Woodhouseb7d11252005-05-19 10:56:58 +0100536 }
Richard Guy Briggs3320c512013-01-24 13:15:11 -0500537
Peter Zijlstra6b55fc62014-10-02 12:22:51 +0200538 wait_event_freezable(kauditd_wait, skb_queue_len(&audit_skb_queue));
David Woodhouseb7d11252005-05-19 10:56:58 +0100539 }
Andrew Morton4899b8b2006-10-06 00:43:48 -0700540 return 0;
David Woodhouseb7d11252005-05-19 10:56:58 +0100541}
542
Paul Moore249293b2020-04-21 09:10:56 -0400543int audit_send_list_thread(void *_dest)
Al Viro9044e6b2006-05-22 01:09:24 -0400544{
545 struct audit_netlink_list *dest = _dest;
Al Viro9044e6b2006-05-22 01:09:24 -0400546 struct sk_buff *skb;
Eric W. Biederman48095d92014-02-03 17:25:33 -0800547 struct net *net = dest->net;
Richard Guy Briggs33faba72013-07-16 13:18:45 -0400548 struct audit_net *aunet = net_generic(net, audit_net_id);
Al Viro9044e6b2006-05-22 01:09:24 -0400549
550 /* wait for parent to finish and send an ACK */
Amy Griffisf368c07d2006-04-07 16:55:56 -0400551 mutex_lock(&audit_cmd_mutex);
552 mutex_unlock(&audit_cmd_mutex);
Al Viro9044e6b2006-05-22 01:09:24 -0400553
554 while ((skb = __skb_dequeue(&dest->q)) != NULL)
Richard Guy Briggs33faba72013-07-16 13:18:45 -0400555 netlink_unicast(aunet->nlsk, skb, dest->portid, 0);
Al Viro9044e6b2006-05-22 01:09:24 -0400556
Eric W. Biederman48095d92014-02-03 17:25:33 -0800557 put_net(net);
Al Viro9044e6b2006-05-22 01:09:24 -0400558 kfree(dest);
559
560 return 0;
561}
562
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400563struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done,
Stephen Hemmingerb8800aa2010-10-20 17:23:50 -0700564 int multi, const void *payload, int size)
Al Viro9044e6b2006-05-22 01:09:24 -0400565{
566 struct sk_buff *skb;
567 struct nlmsghdr *nlh;
Al Viro9044e6b2006-05-22 01:09:24 -0400568 void *data;
569 int flags = multi ? NLM_F_MULTI : 0;
570 int t = done ? NLMSG_DONE : type;
571
Eric Parisee080e62009-06-11 14:31:35 -0400572 skb = nlmsg_new(size, GFP_KERNEL);
Al Viro9044e6b2006-05-22 01:09:24 -0400573 if (!skb)
574 return NULL;
575
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400576 nlh = nlmsg_put(skb, portid, seq, t, size, flags);
David S. Millerc64e66c2012-06-26 21:45:21 -0700577 if (!nlh)
578 goto out_kfree_skb;
579 data = nlmsg_data(nlh);
Al Viro9044e6b2006-05-22 01:09:24 -0400580 memcpy(data, payload, size);
581 return skb;
582
David S. Millerc64e66c2012-06-26 21:45:21 -0700583out_kfree_skb:
584 kfree_skb(skb);
Al Viro9044e6b2006-05-22 01:09:24 -0400585 return NULL;
586}
587
Paul Moore61ec5d82020-04-20 10:09:29 -0400588static void audit_free_reply(struct audit_reply *reply)
589{
590 if (!reply)
591 return;
592
593 if (reply->skb)
594 kfree_skb(reply->skb);
595 if (reply->net)
596 put_net(reply->net);
597 kfree(reply);
598}
599
Eric Parisf09ac9d2008-04-18 10:11:04 -0400600static int audit_send_reply_thread(void *arg)
601{
602 struct audit_reply *reply = (struct audit_reply *)arg;
Eric W. Biederman48095d92014-02-03 17:25:33 -0800603 struct net *net = reply->net;
Richard Guy Briggs33faba72013-07-16 13:18:45 -0400604 struct audit_net *aunet = net_generic(net, audit_net_id);
Eric Parisf09ac9d2008-04-18 10:11:04 -0400605
606 mutex_lock(&audit_cmd_mutex);
607 mutex_unlock(&audit_cmd_mutex);
608
609 /* Ignore failure. It'll only happen if the sender goes away,
610 because our timeout is set to infinite. */
Richard Guy Briggs33faba72013-07-16 13:18:45 -0400611 netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0);
Paul Moore61ec5d82020-04-20 10:09:29 -0400612 reply->skb = NULL;
613 audit_free_reply(reply);
Eric Parisf09ac9d2008-04-18 10:11:04 -0400614 return 0;
615}
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700616/**
617 * audit_send_reply - send an audit reply message via netlink
Eric W. Biedermand211f172014-03-08 15:31:54 -0800618 * @request_skb: skb of request we are replying to (used to target the reply)
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700619 * @seq: sequence number
620 * @type: audit message type
621 * @done: done (last) flag
622 * @multi: multi-part message flag
623 * @payload: payload data
624 * @size: payload size
625 *
Paul Moore61ec5d82020-04-20 10:09:29 -0400626 * Allocates a skb, builds the netlink message, and sends it to the port id.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700627 */
Eric W. Biederman6f285b12014-02-28 19:44:55 -0800628static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400629 int multi, const void *payload, int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630{
Eric W. Biederman6f285b12014-02-28 19:44:55 -0800631 u32 portid = NETLINK_CB(request_skb).portid;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400632 struct task_struct *tsk;
Paul Moore61ec5d82020-04-20 10:09:29 -0400633 struct audit_reply *reply;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400634
Paul Moore61ec5d82020-04-20 10:09:29 -0400635 reply = kzalloc(sizeof(*reply), GFP_KERNEL);
Eric Parisf09ac9d2008-04-18 10:11:04 -0400636 if (!reply)
637 return;
638
Paul Moore61ec5d82020-04-20 10:09:29 -0400639 reply->skb = audit_make_reply(portid, seq, type, done, multi, payload, size);
640 if (!reply->skb)
641 goto err;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400642
Paul Moore61ec5d82020-04-20 10:09:29 -0400643 reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400644 reply->portid = portid;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400645
646 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
Paul Moore61ec5d82020-04-20 10:09:29 -0400647 if (IS_ERR(tsk))
648 goto err;
649
650 return;
651
652err:
653 audit_free_reply(reply);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654}
655
656/*
657 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
658 * control messages.
659 */
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700660static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661{
662 int err = 0;
663
Richard Guy Briggs5a3cb3b2013-08-16 00:04:46 -0400664 /* Only support initial user namespace for now. */
Eric Parisaa4af832014-03-30 19:07:54 -0400665 /*
666 * We return ECONNREFUSED because it tricks userspace into thinking
667 * that audit was not configured into the kernel. Lots of users
668 * configure their PAM stack (because that's what the distro does)
669 * to reject login if unable to send messages to audit. If we return
670 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
671 * configured in and will let login proceed. If we return EPERM
672 * userspace will reject all logins. This should be removed when we
673 * support non init namespaces!!
674 */
Linus Torvalds0b747172014-04-12 12:38:53 -0700675 if (current_user_ns() != &init_user_ns)
Eric Parisaa4af832014-03-30 19:07:54 -0400676 return -ECONNREFUSED;
Eric W. Biederman34e36d82012-09-10 23:20:20 -0700677
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 switch (msg_type) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 case AUDIT_LIST:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 case AUDIT_ADD:
681 case AUDIT_DEL:
Eric Paris18900902013-04-18 19:16:36 -0400682 return -EOPNOTSUPP;
683 case AUDIT_GET:
684 case AUDIT_SET:
Eric Parisb0fed402013-05-22 12:54:49 -0400685 case AUDIT_GET_FEATURE:
686 case AUDIT_SET_FEATURE:
Eric Paris18900902013-04-18 19:16:36 -0400687 case AUDIT_LIST_RULES:
688 case AUDIT_ADD_RULE:
Amy Griffis93315ed2006-02-07 12:05:27 -0500689 case AUDIT_DEL_RULE:
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100690 case AUDIT_SIGNAL_INFO:
Miloslav Trmac522ed772007-07-15 23:40:56 -0700691 case AUDIT_TTY_GET:
692 case AUDIT_TTY_SET:
Al Viro74c3cbe2007-07-22 08:04:18 -0400693 case AUDIT_TRIM:
694 case AUDIT_MAKE_EQUIV:
Richard Guy Briggs5a3cb3b2013-08-16 00:04:46 -0400695 /* Only support auditd and auditctl in initial pid namespace
696 * for now. */
Ameen Ali5985de62015-02-23 15:38:00 -0500697 if (task_active_pid_ns(current) != &init_pid_ns)
Richard Guy Briggs5a3cb3b2013-08-16 00:04:46 -0400698 return -EPERM;
699
Eric W. Biederman90f62cf2014-04-23 14:29:27 -0700700 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 err = -EPERM;
702 break;
Steve Grubb05474102005-05-21 00:18:37 +0100703 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700704 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
705 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
Eric W. Biederman90f62cf2014-04-23 14:29:27 -0700706 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 err = -EPERM;
708 break;
709 default: /* bad msg */
710 err = -EINVAL;
711 }
712
713 return err;
714}
715
Paul Moore233a6862015-11-04 08:23:52 -0500716static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
Eric Paris50397bd2008-01-07 18:14:19 -0500717{
Eric Parisdc9eb692013-04-19 13:23:09 -0400718 uid_t uid = from_kuid(&init_user_ns, current_uid());
Richard Guy Briggsf1dc4862013-12-11 13:52:26 -0500719 pid_t pid = task_tgid_nr(current);
Eric Paris50397bd2008-01-07 18:14:19 -0500720
Tyler Hicks0868a5e2013-07-25 18:02:55 -0700721 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
Eric Paris50397bd2008-01-07 18:14:19 -0500722 *ab = NULL;
Paul Moore233a6862015-11-04 08:23:52 -0500723 return;
Eric Paris50397bd2008-01-07 18:14:19 -0500724 }
725
726 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
Kees Cook0644ec02013-01-11 14:32:07 -0800727 if (unlikely(!*ab))
Paul Moore233a6862015-11-04 08:23:52 -0500728 return;
Richard Guy Briggsf1dc4862013-12-11 13:52:26 -0500729 audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
Eric Paris4d3fb702013-04-30 09:53:34 -0400730 audit_log_session_info(*ab);
Eric Parisb122c372013-04-19 15:00:33 -0400731 audit_log_task_context(*ab);
Eric Paris50397bd2008-01-07 18:14:19 -0500732}
733
Eric Parisb0fed402013-05-22 12:54:49 -0400734int is_audit_feature_set(int i)
735{
736 return af.features & AUDIT_FEATURE_TO_MASK(i);
737}
738
739
740static int audit_get_feature(struct sk_buff *skb)
741{
742 u32 seq;
743
744 seq = nlmsg_hdr(skb)->nlmsg_seq;
745
Richard Guy Briggs9ef91512014-08-24 20:37:52 -0400746 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
Eric Parisb0fed402013-05-22 12:54:49 -0400747
748 return 0;
749}
750
751static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
752 u32 old_lock, u32 new_lock, int res)
753{
754 struct audit_buffer *ab;
755
Gao fengb6c50fe2013-11-01 19:34:43 +0800756 if (audit_enabled == AUDIT_OFF)
757 return;
758
Eric Parisb0fed402013-05-22 12:54:49 -0400759 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE);
Richard Guy Briggs85e924b2018-02-21 04:30:07 -0500760 if (!ab)
761 return;
Richard Guy Briggsad2ac262014-01-07 13:08:41 -0500762 audit_log_task_info(ab, current);
Richard Guy Briggs897f1ac2014-10-30 11:22:53 -0400763 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
Eric Parisb0fed402013-05-22 12:54:49 -0400764 audit_feature_names[which], !!old_feature, !!new_feature,
765 !!old_lock, !!new_lock, res);
766 audit_log_end(ab);
767}
768
Paul Mooreeef128d2020-02-24 16:38:57 -0500769static int audit_set_feature(struct audit_features *uaf)
Eric Parisb0fed402013-05-22 12:54:49 -0400770{
Eric Parisb0fed402013-05-22 12:54:49 -0400771 int i;
772
Fabian Frederick6eed9b22014-06-03 22:05:10 +0200773 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
Eric Parisb0fed402013-05-22 12:54:49 -0400774
775 /* if there is ever a version 2 we should handle that here */
776
777 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
778 u32 feature = AUDIT_FEATURE_TO_MASK(i);
779 u32 old_feature, new_feature, old_lock, new_lock;
780
781 /* if we are not changing this feature, move along */
782 if (!(feature & uaf->mask))
783 continue;
784
785 old_feature = af.features & feature;
786 new_feature = uaf->features & feature;
787 new_lock = (uaf->lock | af.lock) & feature;
788 old_lock = af.lock & feature;
789
790 /* are we changing a locked feature? */
Gao feng4547b3b2013-11-01 19:34:44 +0800791 if (old_lock && (new_feature != old_feature)) {
Eric Parisb0fed402013-05-22 12:54:49 -0400792 audit_log_feature_change(i, old_feature, new_feature,
793 old_lock, new_lock, 0);
794 return -EPERM;
795 }
796 }
797 /* nothing invalid, do the changes */
798 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
799 u32 feature = AUDIT_FEATURE_TO_MASK(i);
800 u32 old_feature, new_feature, old_lock, new_lock;
801
802 /* if we are not changing this feature, move along */
803 if (!(feature & uaf->mask))
804 continue;
805
806 old_feature = af.features & feature;
807 new_feature = uaf->features & feature;
808 old_lock = af.lock & feature;
809 new_lock = (uaf->lock | af.lock) & feature;
810
811 if (new_feature != old_feature)
812 audit_log_feature_change(i, old_feature, new_feature,
813 old_lock, new_lock, 1);
814
815 if (new_feature)
816 af.features |= feature;
817 else
818 af.features &= ~feature;
819 af.lock |= new_lock;
820 }
821
822 return 0;
823}
824
Richard Guy Briggs133e1e52016-01-25 18:04:15 -0500825static int audit_replace(pid_t pid)
826{
Teng Fei Fana4f13562018-10-15 14:02:39 +0800827 int len;
Richard Guy Briggs133e1e52016-01-25 18:04:15 -0500828 struct sk_buff *skb = audit_make_reply(0, 0, AUDIT_REPLACE, 0, 0,
829 &pid, sizeof(pid));
830
831 if (!skb)
832 return -ENOMEM;
Teng Fei Fana4f13562018-10-15 14:02:39 +0800833 mutex_lock(&audit_sock_mutex);
834 len = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
835 mutex_unlock(&audit_sock_mutex);
836 return len;
Richard Guy Briggs133e1e52016-01-25 18:04:15 -0500837}
838
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
840{
Eric Parisdc9eb692013-04-19 13:23:09 -0400841 u32 seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 void *data;
Paul Mooreeef128d2020-02-24 16:38:57 -0500843 int data_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 int err;
Steve Grubbc0404992005-05-13 18:17:42 +0100845 struct audit_buffer *ab;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 u16 msg_type = nlh->nlmsg_type;
Al Viroe1396062006-05-25 10:19:47 -0400847 struct audit_sig_info *sig_data;
Eric Paris50397bd2008-01-07 18:14:19 -0500848 char *ctx = NULL;
Al Viroe1396062006-05-25 10:19:47 -0400849 u32 len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850
Darrel Goeddelc7bdb542006-06-27 13:26:11 -0700851 err = audit_netlink_ok(skb, msg_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 if (err)
853 return err;
854
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700855 /* As soon as there's any sign of userspace auditd,
856 * start kauditd to talk to it */
Gao feng13f51e12013-04-29 15:05:14 -0700857 if (!kauditd_task) {
David Woodhouseb7d11252005-05-19 10:56:58 +0100858 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
Gao feng13f51e12013-04-29 15:05:14 -0700859 if (IS_ERR(kauditd_task)) {
860 err = PTR_ERR(kauditd_task);
861 kauditd_task = NULL;
862 return err;
863 }
David Woodhouseb7d11252005-05-19 10:56:58 +0100864 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 seq = nlh->nlmsg_seq;
David S. Millerc64e66c2012-06-26 21:45:21 -0700866 data = nlmsg_data(nlh);
Paul Mooreeef128d2020-02-24 16:38:57 -0500867 data_len = nlmsg_len(nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868
869 switch (msg_type) {
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400870 case AUDIT_GET: {
871 struct audit_status s;
872 memset(&s, 0, sizeof(s));
873 s.enabled = audit_enabled;
874 s.failure = audit_failure;
875 s.pid = audit_pid;
876 s.rate_limit = audit_rate_limit;
877 s.backlog_limit = audit_backlog_limit;
878 s.lost = atomic_read(&audit_lost);
879 s.backlog = skb_queue_len(&audit_skb_queue);
Richard Guy Briggs0288d712014-11-17 15:51:01 -0500880 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
Richard Guy Briggsa77ed4e2015-02-23 15:37:59 -0500881 s.backlog_wait_time = audit_backlog_wait_time_master;
Eric W. Biederman6f285b12014-02-28 19:44:55 -0800882 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 break;
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400884 }
885 case AUDIT_SET: {
886 struct audit_status s;
887 memset(&s, 0, sizeof(s));
888 /* guard against past and future API changes */
Paul Mooreeef128d2020-02-24 16:38:57 -0500889 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400890 if (s.mask & AUDIT_STATUS_ENABLED) {
891 err = audit_set_enabled(s.enabled);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800892 if (err < 0)
893 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 }
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400895 if (s.mask & AUDIT_STATUS_FAILURE) {
896 err = audit_set_failure(s.failure);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800897 if (err < 0)
898 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 }
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400900 if (s.mask & AUDIT_STATUS_PID) {
Paul Moorefa2bea22016-08-30 17:19:13 -0400901 /* NOTE: we are using task_tgid_vnr() below because
902 * the s.pid value is relative to the namespace
903 * of the caller; at present this doesn't matter
904 * much since you can really only run auditd
905 * from the initial pid namespace, but something
906 * to keep in mind if this changes */
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400907 int new_pid = s.pid;
Richard Guy Briggs133e1e52016-01-25 18:04:15 -0500908 pid_t requesting_pid = task_tgid_vnr(current);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500909
Richard Guy Briggs935c9e72016-01-25 18:04:15 -0500910 if ((!new_pid) && (requesting_pid != audit_pid)) {
911 audit_log_config_change("audit_pid", new_pid, audit_pid, 0);
Richard Guy Briggs34eab0a2013-06-21 14:47:13 -0400912 return -EACCES;
Richard Guy Briggs935c9e72016-01-25 18:04:15 -0500913 }
Richard Guy Briggs133e1e52016-01-25 18:04:15 -0500914 if (audit_pid && new_pid &&
Richard Guy Briggs935c9e72016-01-25 18:04:15 -0500915 audit_replace(requesting_pid) != -ECONNREFUSED) {
916 audit_log_config_change("audit_pid", new_pid, audit_pid, 0);
Richard Guy Briggs133e1e52016-01-25 18:04:15 -0500917 return -EEXIST;
Richard Guy Briggs935c9e72016-01-25 18:04:15 -0500918 }
Eric Paris1a6b9f22008-01-07 17:09:31 -0500919 if (audit_enabled != AUDIT_OFF)
Eric Parisdc9eb692013-04-19 13:23:09 -0400920 audit_log_config_change("audit_pid", new_pid, audit_pid, 1);
Huang Yiwei329c49e2020-02-20 16:34:58 +0800921 mutex_lock(&audit_sock_mutex);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500922 audit_pid = new_pid;
Eric W. Biederman15e47302012-09-07 20:12:54 +0000923 audit_nlk_portid = NETLINK_CB(skb).portid;
Gao fengde92fc92013-12-17 11:10:42 +0800924 audit_sock = skb->sk;
Teng Fei Fana4f13562018-10-15 14:02:39 +0800925 mutex_unlock(&audit_sock_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 }
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400927 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
928 err = audit_set_rate_limit(s.rate_limit);
zhangxiliang20c6aaa2008-07-31 10:11:19 +0800929 if (err < 0)
930 return err;
931 }
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -0400932 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400933 err = audit_set_backlog_limit(s.backlog_limit);
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -0400934 if (err < 0)
935 return err;
936 }
Eric Paris3f0c5fa2014-01-13 16:49:28 -0500937 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
938 if (sizeof(s) > (size_t)nlh->nlmsg_len)
939 return -EINVAL;
Pranith Kumar724e7bf2015-03-11 14:08:19 -0400940 if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
Eric Paris3f0c5fa2014-01-13 16:49:28 -0500941 return -EINVAL;
942 err = audit_set_backlog_wait_time(s.backlog_wait_time);
943 if (err < 0)
944 return err;
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -0400945 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 break;
Richard Guy Briggs09f883a2013-09-18 09:32:24 -0400947 }
Eric Parisb0fed402013-05-22 12:54:49 -0400948 case AUDIT_GET_FEATURE:
949 err = audit_get_feature(skb);
950 if (err)
951 return err;
952 break;
953 case AUDIT_SET_FEATURE:
Paul Mooreeef128d2020-02-24 16:38:57 -0500954 if (data_len < sizeof(struct audit_features))
955 return -EINVAL;
956 err = audit_set_feature(data);
Eric Parisb0fed402013-05-22 12:54:49 -0400957 if (err)
958 return err;
959 break;
Steve Grubb05474102005-05-21 00:18:37 +0100960 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -0700961 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
962 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
David Woodhouse4a4cd632005-06-22 14:56:47 +0100963 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
964 return 0;
Paul Moore3fb1c812020-04-20 16:24:34 -0400965 /* exit early if there isn't at least one character to print */
966 if (data_len < 2)
967 return -EINVAL;
David Woodhouse0f45aa12005-06-19 19:35:50 +0100968
Richard Guy Briggs86b2efb2016-06-24 16:35:46 -0400969 err = audit_filter(msg_type, AUDIT_FILTER_USER);
Richard Guy Briggs724e4fc2013-11-25 21:57:51 -0500970 if (err == 1) { /* match or error */
Paul Mooreeef128d2020-02-24 16:38:57 -0500971 char *str = data;
972
David Woodhouse4a4cd632005-06-22 14:56:47 +0100973 err = 0;
Miloslav Trmac522ed772007-07-15 23:40:56 -0700974 if (msg_type == AUDIT_USER_TTY) {
Peter Hurley37282a72016-01-09 22:55:31 -0800975 err = tty_audit_push();
Miloslav Trmac522ed772007-07-15 23:40:56 -0700976 if (err)
977 break;
978 }
Richard Guy Briggs1b7b5332013-12-02 11:33:01 -0500979 mutex_unlock(&audit_cmd_mutex);
Eric Parisdc9eb692013-04-19 13:23:09 -0400980 audit_log_common_recv_msg(&ab, msg_type);
Paul Mooreeef128d2020-02-24 16:38:57 -0500981 if (msg_type != AUDIT_USER_TTY) {
982 /* ensure NULL termination */
983 str[data_len - 1] = '\0';
Richard Guy Briggsb50eba72013-09-16 18:20:42 -0400984 audit_log_format(ab, " msg='%.*s'",
985 AUDIT_MESSAGE_TEXT_MAX,
Paul Mooreeef128d2020-02-24 16:38:57 -0500986 str);
987 } else {
Eric Parisf7616102013-04-11 11:25:00 -0400988 audit_log_format(ab, " data=");
Paul Mooreeef128d2020-02-24 16:38:57 -0500989 if (data_len > 0 && str[data_len - 1] == '\0')
990 data_len--;
991 audit_log_n_untrustedstring(ab, str, data_len);
David Woodhouse4a4cd632005-06-22 14:56:47 +0100992 }
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400993 audit_set_portid(ab, NETLINK_CB(skb).portid);
Eric Paris50397bd2008-01-07 18:14:19 -0500994 audit_log_end(ab);
Richard Guy Briggs1b7b5332013-12-02 11:33:01 -0500995 mutex_lock(&audit_cmd_mutex);
David Woodhouse0f45aa12005-06-19 19:35:50 +0100996 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 break;
Amy Griffis93315ed2006-02-07 12:05:27 -0500998 case AUDIT_ADD_RULE:
999 case AUDIT_DEL_RULE:
Paul Mooreeef128d2020-02-24 16:38:57 -05001000 if (data_len < sizeof(struct audit_rule_data))
Amy Griffis93315ed2006-02-07 12:05:27 -05001001 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -05001002 if (audit_enabled == AUDIT_LOCKED) {
Eric Parisdc9eb692013-04-19 13:23:09 -04001003 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1004 audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
Eric Paris50397bd2008-01-07 18:14:19 -05001005 audit_log_end(ab);
Steve Grubb6a01b072007-01-19 14:39:55 -05001006 return -EPERM;
1007 }
Richard Guy Briggsce0d9f02013-11-20 14:01:53 -05001008 err = audit_rule_change(msg_type, NETLINK_CB(skb).portid,
Paul Mooreeef128d2020-02-24 16:38:57 -05001009 seq, data, data_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 break;
Richard Guy Briggsce0d9f02013-11-20 14:01:53 -05001011 case AUDIT_LIST_RULES:
Eric W. Biederman6f285b12014-02-28 19:44:55 -08001012 err = audit_list_rules_send(skb, seq);
Richard Guy Briggsce0d9f02013-11-20 14:01:53 -05001013 break;
Al Viro74c3cbe2007-07-22 08:04:18 -04001014 case AUDIT_TRIM:
1015 audit_trim_trees();
Eric Parisdc9eb692013-04-19 13:23:09 -04001016 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
Al Viro74c3cbe2007-07-22 08:04:18 -04001017 audit_log_format(ab, " op=trim res=1");
1018 audit_log_end(ab);
1019 break;
1020 case AUDIT_MAKE_EQUIV: {
1021 void *bufp = data;
1022 u32 sizes[2];
Paul Mooreeef128d2020-02-24 16:38:57 -05001023 size_t msglen = data_len;
Al Viro74c3cbe2007-07-22 08:04:18 -04001024 char *old, *new;
1025
1026 err = -EINVAL;
Harvey Harrison7719e432008-04-27 02:39:56 -07001027 if (msglen < 2 * sizeof(u32))
Al Viro74c3cbe2007-07-22 08:04:18 -04001028 break;
1029 memcpy(sizes, bufp, 2 * sizeof(u32));
1030 bufp += 2 * sizeof(u32);
Harvey Harrison7719e432008-04-27 02:39:56 -07001031 msglen -= 2 * sizeof(u32);
1032 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
Al Viro74c3cbe2007-07-22 08:04:18 -04001033 if (IS_ERR(old)) {
1034 err = PTR_ERR(old);
1035 break;
1036 }
Harvey Harrison7719e432008-04-27 02:39:56 -07001037 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
Al Viro74c3cbe2007-07-22 08:04:18 -04001038 if (IS_ERR(new)) {
1039 err = PTR_ERR(new);
1040 kfree(old);
1041 break;
1042 }
1043 /* OK, here comes... */
1044 err = audit_tag_tree(old, new);
1045
Eric Parisdc9eb692013-04-19 13:23:09 -04001046 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
Eric Paris50397bd2008-01-07 18:14:19 -05001047
Al Viro74c3cbe2007-07-22 08:04:18 -04001048 audit_log_format(ab, " op=make_equiv old=");
1049 audit_log_untrustedstring(ab, old);
1050 audit_log_format(ab, " new=");
1051 audit_log_untrustedstring(ab, new);
1052 audit_log_format(ab, " res=%d", !err);
1053 audit_log_end(ab);
1054 kfree(old);
1055 kfree(new);
1056 break;
1057 }
Steve Grubbc2f0c7c2005-05-06 12:38:39 +01001058 case AUDIT_SIGNAL_INFO:
Eric Paris939cbf22009-09-23 13:46:00 -04001059 len = 0;
1060 if (audit_sig_sid) {
1061 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1062 if (err)
1063 return err;
1064 }
Al Viroe1396062006-05-25 10:19:47 -04001065 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1066 if (!sig_data) {
Eric Paris939cbf22009-09-23 13:46:00 -04001067 if (audit_sig_sid)
1068 security_release_secctx(ctx, len);
Al Viroe1396062006-05-25 10:19:47 -04001069 return -ENOMEM;
1070 }
Eric W. Biedermancca080d2012-02-07 16:53:48 -08001071 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
Al Viroe1396062006-05-25 10:19:47 -04001072 sig_data->pid = audit_sig_pid;
Eric Paris939cbf22009-09-23 13:46:00 -04001073 if (audit_sig_sid) {
1074 memcpy(sig_data->ctx, ctx, len);
1075 security_release_secctx(ctx, len);
1076 }
Eric W. Biederman6f285b12014-02-28 19:44:55 -08001077 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1078 sig_data, sizeof(*sig_data) + len);
Al Viroe1396062006-05-25 10:19:47 -04001079 kfree(sig_data);
Steve Grubbc2f0c7c2005-05-06 12:38:39 +01001080 break;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001081 case AUDIT_TTY_GET: {
1082 struct audit_tty_status s;
Peter Hurley2e28d382016-01-09 22:55:33 -08001083 unsigned int t;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001084
Peter Hurley2e28d382016-01-09 22:55:33 -08001085 t = READ_ONCE(current->signal->audit_tty);
1086 s.enabled = t & AUDIT_TTY_ENABLE;
1087 s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
Thomas Gleixner20703202009-12-09 14:19:35 +00001088
Eric W. Biederman6f285b12014-02-28 19:44:55 -08001089 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
Miloslav Trmac522ed772007-07-15 23:40:56 -07001090 break;
1091 }
1092 case AUDIT_TTY_SET: {
Richard Guy Briggsa06e56b2013-11-15 11:29:02 -05001093 struct audit_tty_status s, old;
Richard Guy Briggsa06e56b2013-11-15 11:29:02 -05001094 struct audit_buffer *ab;
Peter Hurley2e28d382016-01-09 22:55:33 -08001095 unsigned int t;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001096
Richard Guy Briggs46e959e2013-05-03 14:03:50 -04001097 memset(&s, 0, sizeof(s));
1098 /* guard against past and future API changes */
Paul Mooreeef128d2020-02-24 16:38:57 -05001099 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
Eric Paris0e23bac2014-01-13 21:12:34 -05001100 /* check if new data is valid */
1101 if ((s.enabled != 0 && s.enabled != 1) ||
1102 (s.log_passwd != 0 && s.log_passwd != 1))
1103 err = -EINVAL;
1104
Peter Hurley2e28d382016-01-09 22:55:33 -08001105 if (err)
1106 t = READ_ONCE(current->signal->audit_tty);
1107 else {
1108 t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
1109 t = xchg(&current->signal->audit_tty, t);
Eric Paris0e23bac2014-01-13 21:12:34 -05001110 }
Peter Hurley2e28d382016-01-09 22:55:33 -08001111 old.enabled = t & AUDIT_TTY_ENABLE;
1112 old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
Eric Paris0e23bac2014-01-13 21:12:34 -05001113
Richard Guy Briggsa06e56b2013-11-15 11:29:02 -05001114 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
Eric Paris1ce319f2014-01-13 21:16:59 -05001115 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1116 " old-log_passwd=%d new-log_passwd=%d res=%d",
1117 old.enabled, s.enabled, old.log_passwd,
1118 s.log_passwd, !err);
Richard Guy Briggsa06e56b2013-11-15 11:29:02 -05001119 audit_log_end(ab);
Miloslav Trmac522ed772007-07-15 23:40:56 -07001120 break;
1121 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 default:
1123 err = -EINVAL;
1124 break;
1125 }
1126
1127 return err < 0 ? err : 0;
1128}
1129
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001130/*
Eric Parisea7ae602009-06-11 14:31:35 -04001131 * Get message from skb. Each message is processed by audit_receive_msg.
1132 * Malformed skbs with wrong length are discarded silently.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001133 */
Herbert Xu2a0a6eb2005-05-03 14:55:09 -07001134static void audit_receive_skb(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135{
Eric Parisea7ae602009-06-11 14:31:35 -04001136 struct nlmsghdr *nlh;
1137 /*
Hong zhi guo94191212013-03-27 06:49:06 +00001138 * len MUST be signed for nlmsg_next to be able to dec it below 0
Eric Parisea7ae602009-06-11 14:31:35 -04001139 * if the nlmsg_len was not aligned
1140 */
1141 int len;
1142 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143
Eric Parisea7ae602009-06-11 14:31:35 -04001144 nlh = nlmsg_hdr(skb);
1145 len = skb->len;
1146
Hong zhi guo94191212013-03-27 06:49:06 +00001147 while (nlmsg_ok(nlh, len)) {
Eric Parisea7ae602009-06-11 14:31:35 -04001148 err = audit_receive_msg(skb, nlh);
1149 /* if err or if this message says it wants a response */
1150 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151 netlink_ack(skb, nlh, err);
Eric Parisea7ae602009-06-11 14:31:35 -04001152
Alexandru Copot2851da52013-03-28 23:31:29 +02001153 nlh = nlmsg_next(nlh, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155}
1156
1157/* Receive messages from netlink socket. */
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001158static void audit_receive(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159{
Amy Griffisf368c07d2006-04-07 16:55:56 -04001160 mutex_lock(&audit_cmd_mutex);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001161 audit_receive_skb(skb);
Amy Griffisf368c07d2006-04-07 16:55:56 -04001162 mutex_unlock(&audit_cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163}
1164
Richard Guy Briggs3a101b82014-04-22 21:31:56 -04001165/* Run custom bind function on netlink socket group connect or bind requests. */
Johannes Berg023e2cf2014-12-23 21:00:06 +01001166static int audit_bind(struct net *net, int group)
Richard Guy Briggs3a101b82014-04-22 21:31:56 -04001167{
1168 if (!capable(CAP_AUDIT_READ))
1169 return -EPERM;
1170
1171 return 0;
1172}
1173
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001174static int __net_init audit_net_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175{
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +00001176 struct netlink_kernel_cfg cfg = {
1177 .input = audit_receive,
Richard Guy Briggs3a101b82014-04-22 21:31:56 -04001178 .bind = audit_bind,
Richard Guy Briggs451f9212014-04-22 21:31:57 -04001179 .flags = NL_CFG_F_NONROOT_RECV,
1180 .groups = AUDIT_NLGRP_MAX,
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +00001181 };
Amy Griffisf368c07d2006-04-07 16:55:56 -04001182
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001183 struct audit_net *aunet = net_generic(net, audit_net_id);
1184
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001185 aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
Gao feng11ee39e2013-12-17 11:10:41 +08001186 if (aunet->nlsk == NULL) {
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001187 audit_panic("cannot initialize netlink socket in namespace");
Gao feng11ee39e2013-12-17 11:10:41 +08001188 return -ENOMEM;
1189 }
1190 aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001191 return 0;
1192}
1193
1194static void __net_exit audit_net_exit(struct net *net)
1195{
1196 struct audit_net *aunet = net_generic(net, audit_net_id);
1197 struct sock *sock = aunet->nlsk;
Teng Fei Fana4f13562018-10-15 14:02:39 +08001198 mutex_lock(&audit_sock_mutex);
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001199 if (sock == audit_sock) {
1200 audit_pid = 0;
1201 audit_sock = NULL;
1202 }
Teng Fei Fana4f13562018-10-15 14:02:39 +08001203 mutex_unlock(&audit_sock_mutex);
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001204
Monam Agarwale231d542014-03-24 00:16:19 +05301205 RCU_INIT_POINTER(aunet->nlsk, NULL);
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001206 synchronize_net();
1207 netlink_kernel_release(sock);
1208}
1209
Richard Guy Briggs86268772013-07-16 13:18:45 -04001210static struct pernet_operations audit_net_ops __net_initdata = {
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001211 .init = audit_net_init,
1212 .exit = audit_net_exit,
1213 .id = &audit_net_id,
1214 .size = sizeof(struct audit_net),
1215};
1216
1217/* Initialize audit support at boot time. */
1218static int __init audit_init(void)
1219{
1220 int i;
1221
Eric Parisa3f07112008-11-05 12:47:09 -05001222 if (audit_initialized == AUDIT_DISABLED)
1223 return 0;
1224
Joe Perchesd957f7b2014-01-14 10:33:12 -08001225 pr_info("initializing netlink subsys (%s)\n",
1226 audit_default ? "enabled" : "disabled");
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001227 register_pernet_subsys(&audit_net_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228
David Woodhouseb7d11252005-05-19 10:56:58 +01001229 skb_queue_head_init(&audit_skb_queue);
Eric Parisf3d357b2008-04-18 10:02:28 -04001230 skb_queue_head_init(&audit_skb_hold_queue);
Eric Parisa3f07112008-11-05 12:47:09 -05001231 audit_initialized = AUDIT_INITIALIZED;
Darrel Goeddel3dc7e312006-03-10 18:14:06 -06001232
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001233 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
Amy Griffisf368c07d2006-04-07 16:55:56 -04001234
Amy Griffisf368c07d2006-04-07 16:55:56 -04001235 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1236 INIT_LIST_HEAD(&audit_inode_hash[i]);
Amy Griffisf368c07d2006-04-07 16:55:56 -04001237
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 return 0;
1239}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240__initcall(audit_init);
1241
1242/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1243static int __init audit_enable(char *str)
1244{
1245 audit_default = !!simple_strtol(str, NULL, 0);
Eric Parisa3f07112008-11-05 12:47:09 -05001246 if (!audit_default)
1247 audit_initialized = AUDIT_DISABLED;
Paul Moore93dedcf2017-09-01 09:44:34 -04001248 audit_enabled = audit_default;
1249 audit_ever_enabled = !!audit_enabled;
Eric Parisa3f07112008-11-05 12:47:09 -05001250
Joe Perchesd957f7b2014-01-14 10:33:12 -08001251 pr_info("%s\n", audit_default ?
Gao fengd3ca0342013-10-31 14:31:01 +08001252 "enabled (after initialization)" : "disabled (until reboot)");
Eric Parisa3f07112008-11-05 12:47:09 -05001253
OGAWA Hirofumi9b410462006-03-31 02:30:33 -08001254 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256__setup("audit=", audit_enable);
1257
Richard Guy Briggsf910fde2013-09-17 12:34:52 -04001258/* Process kernel command-line parameter at boot time.
1259 * audit_backlog_limit=<n> */
1260static int __init audit_backlog_limit_set(char *str)
1261{
Joe Perches3e1d0bb2014-01-14 10:33:13 -08001262 u32 audit_backlog_limit_arg;
Joe Perchesd957f7b2014-01-14 10:33:12 -08001263
Richard Guy Briggsf910fde2013-09-17 12:34:52 -04001264 pr_info("audit_backlog_limit: ");
Joe Perches3e1d0bb2014-01-14 10:33:13 -08001265 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1266 pr_cont("using default of %u, unable to parse %s\n",
Joe Perchesd957f7b2014-01-14 10:33:12 -08001267 audit_backlog_limit, str);
Richard Guy Briggsf910fde2013-09-17 12:34:52 -04001268 return 1;
1269 }
Joe Perches3e1d0bb2014-01-14 10:33:13 -08001270
1271 audit_backlog_limit = audit_backlog_limit_arg;
Joe Perchesd957f7b2014-01-14 10:33:12 -08001272 pr_cont("%d\n", audit_backlog_limit);
Richard Guy Briggsf910fde2013-09-17 12:34:52 -04001273
1274 return 1;
1275}
1276__setup("audit_backlog_limit=", audit_backlog_limit_set);
1277
Chris Wright16e19042005-05-06 15:53:34 +01001278static void audit_buffer_free(struct audit_buffer *ab)
1279{
1280 unsigned long flags;
1281
Chris Wright8fc61152005-05-06 15:54:17 +01001282 if (!ab)
1283 return;
1284
Markus Elfringd865e572016-01-13 09:18:55 -05001285 kfree_skb(ab->skb);
Chris Wright16e19042005-05-06 15:53:34 +01001286 spin_lock_irqsave(&audit_freelist_lock, flags);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001287 if (audit_freelist_count > AUDIT_MAXFREE)
Chris Wright16e19042005-05-06 15:53:34 +01001288 kfree(ab);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001289 else {
1290 audit_freelist_count++;
Chris Wright16e19042005-05-06 15:53:34 +01001291 list_add(&ab->list, &audit_freelist);
Serge E. Hallyn5d136a02006-04-27 16:45:14 -05001292 }
Chris Wright16e19042005-05-06 15:53:34 +01001293 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1294}
1295
Steve Grubbc0404992005-05-13 18:17:42 +01001296static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
Al Virodd0fc662005-10-07 07:46:04 +01001297 gfp_t gfp_mask, int type)
Chris Wright16e19042005-05-06 15:53:34 +01001298{
1299 unsigned long flags;
1300 struct audit_buffer *ab = NULL;
Steve Grubbc0404992005-05-13 18:17:42 +01001301 struct nlmsghdr *nlh;
Chris Wright16e19042005-05-06 15:53:34 +01001302
1303 spin_lock_irqsave(&audit_freelist_lock, flags);
1304 if (!list_empty(&audit_freelist)) {
1305 ab = list_entry(audit_freelist.next,
1306 struct audit_buffer, list);
1307 list_del(&ab->list);
1308 --audit_freelist_count;
1309 }
1310 spin_unlock_irqrestore(&audit_freelist_lock, flags);
1311
1312 if (!ab) {
David Woodhouse4332bdd2005-05-06 15:59:57 +01001313 ab = kmalloc(sizeof(*ab), gfp_mask);
Chris Wright16e19042005-05-06 15:53:34 +01001314 if (!ab)
Chris Wright8fc61152005-05-06 15:54:17 +01001315 goto err;
Chris Wright16e19042005-05-06 15:53:34 +01001316 }
Chris Wright8fc61152005-05-06 15:54:17 +01001317
David Woodhouseb7d11252005-05-19 10:56:58 +01001318 ab->ctx = ctx;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001319 ab->gfp_mask = gfp_mask;
Eric Parisee080e62009-06-11 14:31:35 -04001320
1321 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1322 if (!ab->skb)
David S. Millerc64e66c2012-06-26 21:45:21 -07001323 goto err;
Eric Parisee080e62009-06-11 14:31:35 -04001324
David S. Millerc64e66c2012-06-26 21:45:21 -07001325 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
1326 if (!nlh)
1327 goto out_kfree_skb;
Eric Parisee080e62009-06-11 14:31:35 -04001328
Chris Wright16e19042005-05-06 15:53:34 +01001329 return ab;
Eric Parisee080e62009-06-11 14:31:35 -04001330
David S. Millerc64e66c2012-06-26 21:45:21 -07001331out_kfree_skb:
Eric Parisee080e62009-06-11 14:31:35 -04001332 kfree_skb(ab->skb);
1333 ab->skb = NULL;
Chris Wright8fc61152005-05-06 15:54:17 +01001334err:
1335 audit_buffer_free(ab);
1336 return NULL;
Chris Wright16e19042005-05-06 15:53:34 +01001337}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001339/**
1340 * audit_serial - compute a serial number for the audit record
1341 *
1342 * Compute a serial number for the audit record. Audit records are
David Woodhousebfb44962005-05-21 21:08:09 +01001343 * written to user-space as soon as they are generated, so a complete
1344 * audit record may be written in several pieces. The timestamp of the
1345 * record and this serial number are used by the user-space tools to
1346 * determine which pieces belong to the same audit record. The
1347 * (timestamp,serial) tuple is unique for each syscall and is live from
1348 * syscall entry to syscall exit.
1349 *
David Woodhousebfb44962005-05-21 21:08:09 +01001350 * NOTE: Another possibility is to store the formatted records off the
1351 * audit context (for those records that have a context), and emit them
1352 * all at syscall exit. However, this could delay the reporting of
1353 * significant errors until syscall exit (or never, if the system
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001354 * halts).
1355 */
David Woodhousebfb44962005-05-21 21:08:09 +01001356unsigned int audit_serial(void)
1357{
Richard Guy Briggs01478d72014-06-13 18:22:00 -04001358 static atomic_t serial = ATOMIC_INIT(0);
David Woodhousebfb44962005-05-21 21:08:09 +01001359
Richard Guy Briggs01478d72014-06-13 18:22:00 -04001360 return atomic_add_return(1, &serial);
David Woodhousebfb44962005-05-21 21:08:09 +01001361}
1362
Daniel Walker5600b892007-10-18 03:06:10 -07001363static inline void audit_get_stamp(struct audit_context *ctx,
David Woodhousebfb44962005-05-21 21:08:09 +01001364 struct timespec *t, unsigned int *serial)
1365{
Al Viro48887e62008-12-06 01:05:50 -05001366 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
David Woodhousebfb44962005-05-21 21:08:09 +01001367 *t = CURRENT_TIME;
1368 *serial = audit_serial();
1369 }
1370}
1371
Andrew Morton82919912013-01-11 14:32:11 -08001372/*
1373 * Wait for auditd to drain the queue a little
1374 */
Eric Parisc81825d2014-01-13 15:42:16 -05001375static long wait_for_auditd(long sleep_time)
Andrew Morton82919912013-01-11 14:32:11 -08001376{
1377 DECLARE_WAITQUEUE(wait, current);
Andrew Morton82919912013-01-11 14:32:11 -08001378
1379 if (audit_backlog_limit &&
Paul Moore7ffb8e32016-04-04 16:44:02 -04001380 skb_queue_len(&audit_skb_queue) > audit_backlog_limit) {
1381 add_wait_queue_exclusive(&audit_backlog_wait, &wait);
1382 set_current_state(TASK_UNINTERRUPTIBLE);
Eric Parisc81825d2014-01-13 15:42:16 -05001383 sleep_time = schedule_timeout(sleep_time);
Paul Moore7ffb8e32016-04-04 16:44:02 -04001384 remove_wait_queue(&audit_backlog_wait, &wait);
1385 }
Richard Guy Briggsae887e02013-09-16 10:45:59 -04001386
Eric Parisc81825d2014-01-13 15:42:16 -05001387 return sleep_time;
Andrew Morton82919912013-01-11 14:32:11 -08001388}
1389
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001390/**
1391 * audit_log_start - obtain an audit buffer
1392 * @ctx: audit_context (may be NULL)
1393 * @gfp_mask: type of allocation
1394 * @type: audit message type
1395 *
1396 * Returns audit_buffer pointer on success or NULL on error.
1397 *
1398 * Obtain an audit buffer. This routine does locking to obtain the
1399 * audit buffer, but then no locking is required for calls to
1400 * audit_log_*format. If the task (ctx) is a task that is currently in a
1401 * syscall, then the syscall is marked as auditable and an audit record
1402 * will be written at syscall exit. If there is no associated task, then
1403 * task context (ctx) should be NULL.
1404 */
Al Viro9796fdd2005-10-21 03:22:03 -04001405struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001406 int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407{
1408 struct audit_buffer *ab = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 struct timespec t;
Andrew Mortonef00be02008-01-10 11:02:39 -08001410 unsigned int uninitialized_var(serial);
Toshiyuki Okajima6dd80ab2013-12-05 16:15:23 +09001411 int reserve = 5; /* Allow atomic callers to go up to five
1412 entries over the normal backlog limit */
David Woodhouseac4cec42005-07-02 14:08:48 +01001413 unsigned long timeout_start = jiffies;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001414
Eric Parisa3f07112008-11-05 12:47:09 -05001415 if (audit_initialized != AUDIT_INITIALIZED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001416 return NULL;
1417
Richard Guy Briggs86b2efb2016-06-24 16:35:46 -04001418 if (unlikely(!audit_filter(type, AUDIT_FILTER_TYPE)))
Dustin Kirklandc8edc802005-11-03 16:12:36 +00001419 return NULL;
1420
Mel Gormand0164ad2015-11-06 16:28:21 -08001421 if (gfp_mask & __GFP_DIRECT_RECLAIM) {
Richard Guy Briggsf48a9422016-01-13 09:15:19 -05001422 if (audit_pid && audit_pid == current->tgid)
Mel Gormand0164ad2015-11-06 16:28:21 -08001423 gfp_mask &= ~__GFP_DIRECT_RECLAIM;
Toshiyuki Okajima6dd80ab2013-12-05 16:15:23 +09001424 else
1425 reserve = 0;
1426 }
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001427
1428 while (audit_backlog_limit
1429 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
Mel Gormand0164ad2015-11-06 16:28:21 -08001430 if (gfp_mask & __GFP_DIRECT_RECLAIM && audit_backlog_wait_time) {
Eric Parisc81825d2014-01-13 15:42:16 -05001431 long sleep_time;
David Woodhouseac4cec42005-07-02 14:08:48 +01001432
Eric Parisc81825d2014-01-13 15:42:16 -05001433 sleep_time = timeout_start + audit_backlog_wait_time - jiffies;
1434 if (sleep_time > 0) {
Richard Guy Briggsae887e02013-09-16 10:45:59 -04001435 sleep_time = wait_for_auditd(sleep_time);
Eric Parisc81825d2014-01-13 15:42:16 -05001436 if (sleep_time > 0)
Richard Guy Briggsae887e02013-09-16 10:45:59 -04001437 continue;
Konstantin Khlebnikov8ac1c8d2013-09-24 15:27:42 -07001438 }
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001439 }
Eric Paris320f1b12008-01-23 22:55:05 -05001440 if (audit_rate_check() && printk_ratelimit())
Joe Perchesd957f7b2014-01-14 10:33:12 -08001441 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1442 skb_queue_len(&audit_skb_queue),
1443 audit_backlog_limit);
David Woodhousefb19b4c2005-05-19 14:55:56 +01001444 audit_log_lost("backlog limit exceeded");
Paul Mooreeb8baf62016-01-13 09:15:18 -05001445 audit_backlog_wait_time = 0;
David Woodhouseac4cec42005-07-02 14:08:48 +01001446 wake_up(&audit_backlog_wait);
David Woodhousefb19b4c2005-05-19 14:55:56 +01001447 return NULL;
1448 }
1449
Richard Guy Briggsc4b7a772016-01-13 09:15:18 -05001450 if (!reserve && !audit_backlog_wait_time)
Richard Guy Briggsefef73a2015-02-23 15:38:00 -05001451 audit_backlog_wait_time = audit_backlog_wait_time_master;
Richard Guy Briggse789e562013-09-12 23:03:51 -04001452
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001453 ab = audit_buffer_alloc(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454 if (!ab) {
1455 audit_log_lost("out of memory in audit_log_start");
1456 return NULL;
1457 }
1458
David Woodhousebfb44962005-05-21 21:08:09 +01001459 audit_get_stamp(ab->ctx, &t, &serial);
Chris Wright197c69c2005-05-11 10:54:05 +01001460
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1462 t.tv_sec, t.tv_nsec/1000000, serial);
1463 return ab;
1464}
1465
Chris Wright8fc61152005-05-06 15:54:17 +01001466/**
Chris Wright5ac52f32005-05-06 15:54:53 +01001467 * audit_expand - expand skb in the audit buffer
Chris Wright8fc61152005-05-06 15:54:17 +01001468 * @ab: audit_buffer
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001469 * @extra: space to add at tail of the skb
Chris Wright8fc61152005-05-06 15:54:17 +01001470 *
1471 * Returns 0 (no space) on failed expansion, or available space if
1472 * successful.
1473 */
David Woodhousee3b926b2005-05-10 18:56:08 +01001474static inline int audit_expand(struct audit_buffer *ab, int extra)
Chris Wright8fc61152005-05-06 15:54:17 +01001475{
Chris Wright5ac52f32005-05-06 15:54:53 +01001476 struct sk_buff *skb = ab->skb;
Herbert Xu406a1d82008-01-28 20:47:09 -08001477 int oldtail = skb_tailroom(skb);
1478 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1479 int newtail = skb_tailroom(skb);
1480
Chris Wright5ac52f32005-05-06 15:54:53 +01001481 if (ret < 0) {
1482 audit_log_lost("out of memory in audit_expand");
Chris Wright8fc61152005-05-06 15:54:17 +01001483 return 0;
Chris Wright5ac52f32005-05-06 15:54:53 +01001484 }
Herbert Xu406a1d82008-01-28 20:47:09 -08001485
1486 skb->truesize += newtail - oldtail;
1487 return newtail;
Chris Wright8fc61152005-05-06 15:54:17 +01001488}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001489
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001490/*
1491 * Format an audit message into the audit buffer. If there isn't enough
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492 * room in the audit buffer, more room will be allocated and vsnprint
1493 * will be called a second time. Currently, we assume that a printk
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001494 * can't format message larger than 1024 bytes, so we don't either.
1495 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001496static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1497 va_list args)
1498{
1499 int len, avail;
Chris Wright5ac52f32005-05-06 15:54:53 +01001500 struct sk_buff *skb;
David Woodhouseeecb0a72005-05-10 18:58:51 +01001501 va_list args2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001502
1503 if (!ab)
1504 return;
1505
Chris Wright5ac52f32005-05-06 15:54:53 +01001506 BUG_ON(!ab->skb);
1507 skb = ab->skb;
1508 avail = skb_tailroom(skb);
1509 if (avail == 0) {
David Woodhousee3b926b2005-05-10 18:56:08 +01001510 avail = audit_expand(ab, AUDIT_BUFSIZ);
Chris Wright8fc61152005-05-06 15:54:17 +01001511 if (!avail)
1512 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513 }
David Woodhouseeecb0a72005-05-10 18:58:51 +01001514 va_copy(args2, args);
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001515 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001516 if (len >= avail) {
1517 /* The printk buffer is 1024 bytes long, so if we get
1518 * here and AUDIT_BUFSIZ is at least 1024, then we can
1519 * log everything that printk could have logged. */
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001520 avail = audit_expand(ab,
1521 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
Chris Wright8fc61152005-05-06 15:54:17 +01001522 if (!avail)
Jesper Juhla0e86bd2012-01-08 22:44:29 +01001523 goto out_va_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001524 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001525 }
Steve Grubb168b7172005-05-19 10:24:22 +01001526 if (len > 0)
1527 skb_put(skb, len);
Jesper Juhla0e86bd2012-01-08 22:44:29 +01001528out_va_end:
1529 va_end(args2);
Chris Wright8fc61152005-05-06 15:54:17 +01001530out:
1531 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001532}
1533
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001534/**
1535 * audit_log_format - format a message into the audit buffer.
1536 * @ab: audit_buffer
1537 * @fmt: format string
1538 * @...: optional parameters matching @fmt string
1539 *
1540 * All the work is done in audit_log_vformat.
1541 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1543{
1544 va_list args;
1545
1546 if (!ab)
1547 return;
1548 va_start(args, fmt);
1549 audit_log_vformat(ab, fmt, args);
1550 va_end(args);
1551}
1552
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001553/**
1554 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1555 * @ab: the audit_buffer
1556 * @buf: buffer to convert to hex
1557 * @len: length of @buf to be converted
1558 *
1559 * No return value; failure to expand is silently ignored.
1560 *
1561 * This function will take the passed buf and convert it into a string of
1562 * ascii hex digits. The new string is placed onto the skb.
1563 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001564void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
Steve Grubb168b7172005-05-19 10:24:22 +01001565 size_t len)
83c7d092005-04-29 15:54:44 +01001566{
Steve Grubb168b7172005-05-19 10:24:22 +01001567 int i, avail, new_len;
1568 unsigned char *ptr;
1569 struct sk_buff *skb;
83c7d092005-04-29 15:54:44 +01001570
Amy Griffis8ef2d302006-09-07 17:03:02 -04001571 if (!ab)
1572 return;
1573
Steve Grubb168b7172005-05-19 10:24:22 +01001574 BUG_ON(!ab->skb);
1575 skb = ab->skb;
1576 avail = skb_tailroom(skb);
1577 new_len = len<<1;
1578 if (new_len >= avail) {
1579 /* Round the buffer request up to the next multiple */
1580 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1581 avail = audit_expand(ab, new_len);
1582 if (!avail)
1583 return;
1584 }
1585
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001586 ptr = skb_tail_pointer(skb);
Joe Perchesb8dbc322014-01-13 23:31:27 -08001587 for (i = 0; i < len; i++)
1588 ptr = hex_byte_pack_upper(ptr, buf[i]);
Steve Grubb168b7172005-05-19 10:24:22 +01001589 *ptr = 0;
1590 skb_put(skb, len << 1); /* new string is twice the old string */
83c7d092005-04-29 15:54:44 +01001591}
1592
Amy Griffis9c937dc2006-06-08 23:19:31 -04001593/*
1594 * Format a string of no more than slen characters into the audit buffer,
1595 * enclosed in quote marks.
1596 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001597void audit_log_n_string(struct audit_buffer *ab, const char *string,
1598 size_t slen)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001599{
1600 int avail, new_len;
1601 unsigned char *ptr;
1602 struct sk_buff *skb;
1603
Amy Griffis8ef2d302006-09-07 17:03:02 -04001604 if (!ab)
1605 return;
1606
Amy Griffis9c937dc2006-06-08 23:19:31 -04001607 BUG_ON(!ab->skb);
1608 skb = ab->skb;
1609 avail = skb_tailroom(skb);
1610 new_len = slen + 3; /* enclosing quotes + null terminator */
1611 if (new_len > avail) {
1612 avail = audit_expand(ab, new_len);
1613 if (!avail)
1614 return;
1615 }
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001616 ptr = skb_tail_pointer(skb);
Amy Griffis9c937dc2006-06-08 23:19:31 -04001617 *ptr++ = '"';
1618 memcpy(ptr, string, slen);
1619 ptr += slen;
1620 *ptr++ = '"';
1621 *ptr = 0;
1622 skb_put(skb, slen + 2); /* don't include null terminator */
1623}
1624
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001625/**
Eric Parisde6bbd12008-01-07 14:31:58 -05001626 * audit_string_contains_control - does a string need to be logged in hex
Dave Jonesf706d5d2008-03-28 14:15:56 -07001627 * @string: string to be checked
1628 * @len: max length of the string to check
Eric Parisde6bbd12008-01-07 14:31:58 -05001629 */
Yaowei Bai9fcf8362015-11-04 08:23:51 -05001630bool audit_string_contains_control(const char *string, size_t len)
Eric Parisde6bbd12008-01-07 14:31:58 -05001631{
1632 const unsigned char *p;
Miloslav Trmacb3897f52009-03-19 09:48:27 -04001633 for (p = string; p < (const unsigned char *)string + len; p++) {
Vesa-Matti J Kari1d6c9642008-07-23 00:06:13 +03001634 if (*p == '"' || *p < 0x21 || *p > 0x7e)
Yaowei Bai9fcf8362015-11-04 08:23:51 -05001635 return true;
Eric Parisde6bbd12008-01-07 14:31:58 -05001636 }
Yaowei Bai9fcf8362015-11-04 08:23:51 -05001637 return false;
Eric Parisde6bbd12008-01-07 14:31:58 -05001638}
1639
1640/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001641 * audit_log_n_untrustedstring - log a string that may contain random characters
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001642 * @ab: audit_buffer
Dave Jonesf706d5d2008-03-28 14:15:56 -07001643 * @len: length of string (not including trailing null)
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001644 * @string: string to be logged
1645 *
1646 * This code will escape a string that is passed to it if the string
1647 * contains a control character, unprintable character, double quote mark,
Steve Grubb168b7172005-05-19 10:24:22 +01001648 * or a space. Unescaped strings will start and end with a double quote mark.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001649 * Strings that are escaped are printed in hex (2 digits per char).
Amy Griffis9c937dc2006-06-08 23:19:31 -04001650 *
1651 * The caller specifies the number of characters in the string to log, which may
1652 * or may not be the entire string.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001653 */
Eric Parisb556f8a2008-04-18 10:12:59 -04001654void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1655 size_t len)
83c7d092005-04-29 15:54:44 +01001656{
Eric Parisde6bbd12008-01-07 14:31:58 -05001657 if (audit_string_contains_control(string, len))
Eric Parisb556f8a2008-04-18 10:12:59 -04001658 audit_log_n_hex(ab, string, len);
Eric Parisde6bbd12008-01-07 14:31:58 -05001659 else
Eric Parisb556f8a2008-04-18 10:12:59 -04001660 audit_log_n_string(ab, string, len);
83c7d092005-04-29 15:54:44 +01001661}
1662
Amy Griffis9c937dc2006-06-08 23:19:31 -04001663/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07001664 * audit_log_untrustedstring - log a string that may contain random characters
Amy Griffis9c937dc2006-06-08 23:19:31 -04001665 * @ab: audit_buffer
1666 * @string: string to be logged
1667 *
Miloslav Trmac522ed772007-07-15 23:40:56 -07001668 * Same as audit_log_n_untrustedstring(), except that strlen is used to
Amy Griffis9c937dc2006-06-08 23:19:31 -04001669 * determine string length.
1670 */
Eric Parisde6bbd12008-01-07 14:31:58 -05001671void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
Amy Griffis9c937dc2006-06-08 23:19:31 -04001672{
Eric Parisb556f8a2008-04-18 10:12:59 -04001673 audit_log_n_untrustedstring(ab, string, strlen(string));
Amy Griffis9c937dc2006-06-08 23:19:31 -04001674}
1675
Steve Grubb168b7172005-05-19 10:24:22 +01001676/* This is a helper-function to print the escaped d_path */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
Al Viro66b3fad2012-03-14 21:48:20 -04001678 const struct path *path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001679{
Jan Blunck44707fd2008-02-14 19:38:33 -08001680 char *p, *pathname;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681
Chris Wright8fc61152005-05-06 15:54:17 +01001682 if (prefix)
Kees Cookc158a352012-01-06 14:07:10 -08001683 audit_log_format(ab, "%s", prefix);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684
Steve Grubb168b7172005-05-19 10:24:22 +01001685 /* We will allow 11 spaces for ' (deleted)' to be appended */
Jan Blunck44707fd2008-02-14 19:38:33 -08001686 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1687 if (!pathname) {
Eric Parisdef57542009-03-10 18:00:14 -04001688 audit_log_string(ab, "<no_memory>");
Steve Grubb168b7172005-05-19 10:24:22 +01001689 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 }
Jan Blunckcf28b482008-02-14 19:38:44 -08001691 p = d_path(path, pathname, PATH_MAX+11);
Steve Grubb168b7172005-05-19 10:24:22 +01001692 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
1693 /* FIXME: can we save some information here? */
Eric Parisdef57542009-03-10 18:00:14 -04001694 audit_log_string(ab, "<too_long>");
Daniel Walker5600b892007-10-18 03:06:10 -07001695 } else
Steve Grubb168b7172005-05-19 10:24:22 +01001696 audit_log_untrustedstring(ab, p);
Jan Blunck44707fd2008-02-14 19:38:33 -08001697 kfree(pathname);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698}
1699
Eric Paris4d3fb702013-04-30 09:53:34 -04001700void audit_log_session_info(struct audit_buffer *ab)
1701{
Eric Paris4440e852013-11-27 17:35:17 -05001702 unsigned int sessionid = audit_get_sessionid(current);
Eric Paris4d3fb702013-04-30 09:53:34 -04001703 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1704
Richard Guy Briggsb8f89ca2013-09-18 11:17:43 -04001705 audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
Eric Paris4d3fb702013-04-30 09:53:34 -04001706}
1707
Eric Paris9d960982009-06-11 14:31:37 -04001708void audit_log_key(struct audit_buffer *ab, char *key)
1709{
1710 audit_log_format(ab, " key=");
1711 if (key)
1712 audit_log_untrustedstring(ab, key);
1713 else
1714 audit_log_format(ab, "(null)");
1715}
1716
Eric Parisb24a30a2013-04-30 15:30:32 -04001717void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1718{
1719 int i;
1720
1721 audit_log_format(ab, " %s=", prefix);
1722 CAP_FOR_EACH_U32(i) {
1723 audit_log_format(ab, "%08x",
Eric Paris7d8b6c62014-07-23 15:36:26 -04001724 cap->cap[CAP_LAST_U32 - i]);
Eric Parisb24a30a2013-04-30 15:30:32 -04001725 }
1726}
1727
Richard Guy Briggs691e6d52014-05-26 11:02:48 -04001728static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
Eric Parisb24a30a2013-04-30 15:30:32 -04001729{
1730 kernel_cap_t *perm = &name->fcap.permitted;
1731 kernel_cap_t *inh = &name->fcap.inheritable;
1732 int log = 0;
1733
1734 if (!cap_isclear(*perm)) {
1735 audit_log_cap(ab, "cap_fp", perm);
1736 log = 1;
1737 }
1738 if (!cap_isclear(*inh)) {
1739 audit_log_cap(ab, "cap_fi", inh);
1740 log = 1;
1741 }
1742
1743 if (log)
1744 audit_log_format(ab, " cap_fe=%d cap_fver=%x",
1745 name->fcap.fE, name->fcap_ver);
1746}
1747
1748static inline int audit_copy_fcaps(struct audit_names *name,
1749 const struct dentry *dentry)
1750{
1751 struct cpu_vfs_cap_data caps;
1752 int rc;
1753
1754 if (!dentry)
1755 return 0;
1756
1757 rc = get_vfs_caps_from_disk(dentry, &caps);
1758 if (rc)
1759 return rc;
1760
1761 name->fcap.permitted = caps.permitted;
1762 name->fcap.inheritable = caps.inheritable;
1763 name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1764 name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
1765 VFS_CAP_REVISION_SHIFT;
1766
1767 return 0;
1768}
1769
1770/* Copy inode data into an audit_names. */
1771void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
Andreas Gruenbacherd6335d72015-12-24 11:09:39 -05001772 struct inode *inode)
Eric Parisb24a30a2013-04-30 15:30:32 -04001773{
1774 name->ino = inode->i_ino;
1775 name->dev = inode->i_sb->s_dev;
1776 name->mode = inode->i_mode;
1777 name->uid = inode->i_uid;
1778 name->gid = inode->i_gid;
1779 name->rdev = inode->i_rdev;
1780 security_inode_getsecid(inode, &name->osid);
1781 audit_copy_fcaps(name, dentry);
1782}
1783
1784/**
1785 * audit_log_name - produce AUDIT_PATH record from struct audit_names
1786 * @context: audit_context for the task
1787 * @n: audit_names structure with reportable details
1788 * @path: optional path to report instead of audit_names->name
1789 * @record_num: record number to report when handling a list of names
1790 * @call_panic: optional pointer to int that will be updated if secid fails
1791 */
1792void audit_log_name(struct audit_context *context, struct audit_names *n,
1793 struct path *path, int record_num, int *call_panic)
1794{
1795 struct audit_buffer *ab;
1796 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1797 if (!ab)
1798 return;
1799
1800 audit_log_format(ab, "item=%d", record_num);
1801
1802 if (path)
1803 audit_log_d_path(ab, " name=", path);
1804 else if (n->name) {
1805 switch (n->name_len) {
1806 case AUDIT_NAME_FULL:
1807 /* log the full path */
1808 audit_log_format(ab, " name=");
1809 audit_log_untrustedstring(ab, n->name->name);
1810 break;
1811 case 0:
1812 /* name was specified as a relative path and the
1813 * directory component is the cwd */
1814 audit_log_d_path(ab, " name=", &context->pwd);
1815 break;
1816 default:
1817 /* log the name's directory component */
1818 audit_log_format(ab, " name=");
1819 audit_log_n_untrustedstring(ab, n->name->name,
1820 n->name_len);
1821 }
1822 } else
1823 audit_log_format(ab, " name=(null)");
1824
Linus Torvalds425afcf2015-09-08 13:34:59 -07001825 if (n->ino != AUDIT_INO_UNSET)
Eric Parisb24a30a2013-04-30 15:30:32 -04001826 audit_log_format(ab, " inode=%lu"
1827 " dev=%02x:%02x mode=%#ho"
1828 " ouid=%u ogid=%u rdev=%02x:%02x",
1829 n->ino,
1830 MAJOR(n->dev),
1831 MINOR(n->dev),
1832 n->mode,
1833 from_kuid(&init_user_ns, n->uid),
1834 from_kgid(&init_user_ns, n->gid),
1835 MAJOR(n->rdev),
1836 MINOR(n->rdev));
Eric Parisb24a30a2013-04-30 15:30:32 -04001837 if (n->osid != 0) {
1838 char *ctx = NULL;
1839 u32 len;
1840 if (security_secid_to_secctx(
1841 n->osid, &ctx, &len)) {
1842 audit_log_format(ab, " osid=%u", n->osid);
1843 if (call_panic)
1844 *call_panic = 2;
1845 } else {
1846 audit_log_format(ab, " obj=%s", ctx);
1847 security_release_secctx(ctx, len);
1848 }
1849 }
1850
Jeff Laytond3aea842013-05-08 10:32:23 -04001851 /* log the audit_names record type */
1852 audit_log_format(ab, " nametype=");
1853 switch(n->type) {
1854 case AUDIT_TYPE_NORMAL:
1855 audit_log_format(ab, "NORMAL");
1856 break;
1857 case AUDIT_TYPE_PARENT:
1858 audit_log_format(ab, "PARENT");
1859 break;
1860 case AUDIT_TYPE_CHILD_DELETE:
1861 audit_log_format(ab, "DELETE");
1862 break;
1863 case AUDIT_TYPE_CHILD_CREATE:
1864 audit_log_format(ab, "CREATE");
1865 break;
1866 default:
1867 audit_log_format(ab, "UNKNOWN");
1868 break;
1869 }
1870
Eric Parisb24a30a2013-04-30 15:30:32 -04001871 audit_log_fcaps(ab, n);
1872 audit_log_end(ab);
1873}
1874
1875int audit_log_task_context(struct audit_buffer *ab)
1876{
1877 char *ctx = NULL;
1878 unsigned len;
1879 int error;
1880 u32 sid;
1881
1882 security_task_getsecid(current, &sid);
1883 if (!sid)
1884 return 0;
1885
1886 error = security_secid_to_secctx(sid, &ctx, &len);
1887 if (error) {
1888 if (error != -EINVAL)
1889 goto error_path;
1890 return 0;
1891 }
1892
1893 audit_log_format(ab, " subj=%s", ctx);
1894 security_release_secctx(ctx, len);
1895 return 0;
1896
1897error_path:
1898 audit_panic("error in audit_log_task_context");
1899 return error;
1900}
1901EXPORT_SYMBOL(audit_log_task_context);
1902
Davidlohr Bueso4766b192015-02-22 18:20:00 -08001903void audit_log_d_path_exe(struct audit_buffer *ab,
1904 struct mm_struct *mm)
1905{
Davidlohr Bueso5b282552015-02-22 18:20:09 -08001906 struct file *exe_file;
Davidlohr Bueso4766b192015-02-22 18:20:00 -08001907
Davidlohr Bueso5b282552015-02-22 18:20:09 -08001908 if (!mm)
1909 goto out_null;
1910
1911 exe_file = get_mm_exe_file(mm);
1912 if (!exe_file)
1913 goto out_null;
1914
1915 audit_log_d_path(ab, " exe=", &exe_file->f_path);
1916 fput(exe_file);
1917 return;
1918out_null:
1919 audit_log_format(ab, " exe=(null)");
Davidlohr Bueso4766b192015-02-22 18:20:00 -08001920}
1921
Richard Guy Briggs3f5be2d2016-06-28 12:07:50 -04001922struct tty_struct *audit_get_tty(struct task_struct *tsk)
1923{
1924 struct tty_struct *tty = NULL;
1925 unsigned long flags;
1926
1927 spin_lock_irqsave(&tsk->sighand->siglock, flags);
1928 if (tsk->signal)
1929 tty = tty_kref_get(tsk->signal->tty);
1930 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
1931 return tty;
1932}
1933
1934void audit_put_tty(struct tty_struct *tty)
1935{
1936 tty_kref_put(tty);
1937}
1938
Eric Parisb24a30a2013-04-30 15:30:32 -04001939void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
1940{
1941 const struct cred *cred;
Richard Guy Briggs9eab3392014-03-15 18:42:34 -04001942 char comm[sizeof(tsk->comm)];
Richard Guy Briggsdb0a6fb2016-04-21 14:14:01 -04001943 struct tty_struct *tty;
Eric Parisb24a30a2013-04-30 15:30:32 -04001944
1945 if (!ab)
1946 return;
1947
1948 /* tsk == current */
1949 cred = current_cred();
Richard Guy Briggsdb0a6fb2016-04-21 14:14:01 -04001950 tty = audit_get_tty(tsk);
Eric Parisb24a30a2013-04-30 15:30:32 -04001951 audit_log_format(ab,
Richard Guy Briggsc92cdeb2013-12-10 22:10:41 -05001952 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
Eric Parisb24a30a2013-04-30 15:30:32 -04001953 " euid=%u suid=%u fsuid=%u"
Richard Guy Briggs2f2ad102013-07-15 10:23:11 -04001954 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
Richard Guy Briggsc92cdeb2013-12-10 22:10:41 -05001955 task_ppid_nr(tsk),
Paul Moorefa2bea22016-08-30 17:19:13 -04001956 task_tgid_nr(tsk),
Eric Parisb24a30a2013-04-30 15:30:32 -04001957 from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
1958 from_kuid(&init_user_ns, cred->uid),
1959 from_kgid(&init_user_ns, cred->gid),
1960 from_kuid(&init_user_ns, cred->euid),
1961 from_kuid(&init_user_ns, cred->suid),
1962 from_kuid(&init_user_ns, cred->fsuid),
1963 from_kgid(&init_user_ns, cred->egid),
1964 from_kgid(&init_user_ns, cred->sgid),
1965 from_kgid(&init_user_ns, cred->fsgid),
Richard Guy Briggsdb0a6fb2016-04-21 14:14:01 -04001966 tty ? tty_name(tty) : "(none)",
1967 audit_get_sessionid(tsk));
1968 audit_put_tty(tty);
Eric Parisb24a30a2013-04-30 15:30:32 -04001969 audit_log_format(ab, " comm=");
Richard Guy Briggs9eab3392014-03-15 18:42:34 -04001970 audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
Davidlohr Bueso4766b192015-02-22 18:20:00 -08001971 audit_log_d_path_exe(ab, tsk->mm);
Eric Parisb24a30a2013-04-30 15:30:32 -04001972 audit_log_task_context(ab);
1973}
1974EXPORT_SYMBOL(audit_log_task_info);
1975
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001976/**
Kees Cooka51d9ea2012-07-25 17:29:08 -07001977 * audit_log_link_denied - report a link restriction denial
Shailendra Verma220119642015-05-23 10:40:27 +05301978 * @operation: specific link operation
Kees Cooka51d9ea2012-07-25 17:29:08 -07001979 * @link: the path that triggered the restriction
1980 */
1981void audit_log_link_denied(const char *operation, struct path *link)
1982{
1983 struct audit_buffer *ab;
Eric Parisb24a30a2013-04-30 15:30:32 -04001984 struct audit_names *name;
Kees Cooka51d9ea2012-07-25 17:29:08 -07001985
Eric Parisb24a30a2013-04-30 15:30:32 -04001986 name = kzalloc(sizeof(*name), GFP_NOFS);
1987 if (!name)
1988 return;
1989
1990 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
Kees Cooka51d9ea2012-07-25 17:29:08 -07001991 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1992 AUDIT_ANOM_LINK);
Sasha Levind1c7d972012-10-04 19:57:31 -04001993 if (!ab)
Eric Parisb24a30a2013-04-30 15:30:32 -04001994 goto out;
1995 audit_log_format(ab, "op=%s", operation);
1996 audit_log_task_info(ab, current);
1997 audit_log_format(ab, " res=0");
Kees Cooka51d9ea2012-07-25 17:29:08 -07001998 audit_log_end(ab);
Eric Parisb24a30a2013-04-30 15:30:32 -04001999
2000 /* Generate AUDIT_PATH record with object. */
2001 name->type = AUDIT_TYPE_NORMAL;
David Howells3b362152015-03-17 22:26:21 +00002002 audit_copy_inode(name, link->dentry, d_backing_inode(link->dentry));
Eric Parisb24a30a2013-04-30 15:30:32 -04002003 audit_log_name(current->audit_context, name, link, 0, NULL);
2004out:
2005 kfree(name);
Kees Cooka51d9ea2012-07-25 17:29:08 -07002006}
2007
2008/**
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002009 * audit_log_end - end one audit record
2010 * @ab: the audit_buffer
2011 *
Richard Guy Briggs451f9212014-04-22 21:31:57 -04002012 * netlink_unicast() cannot be called inside an irq context because it blocks
2013 * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed
2014 * on a queue and a tasklet is scheduled to remove them from the queue outside
2015 * the irq context. May be called in any context.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002016 */
David Woodhouseb7d11252005-05-19 10:56:58 +01002017void audit_log_end(struct audit_buffer *ab)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002018{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002019 if (!ab)
2020 return;
2021 if (!audit_rate_check()) {
2022 audit_log_lost("rate limit exceeded");
2023 } else {
Steve Grubb8d07a672008-02-21 16:59:22 -05002024 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
Richard Guy Briggs451f9212014-04-22 21:31:57 -04002025
Richard Guy Briggs54e05ed2014-08-21 13:40:41 -04002026 nlh->nlmsg_len = ab->skb->len;
Richard Guy Briggs54dc77d2014-12-18 23:09:27 -05002027 kauditd_send_multicast_skb(ab->skb, ab->gfp_mask);
Richard Guy Briggs451f9212014-04-22 21:31:57 -04002028
2029 /*
2030 * The original kaudit unicast socket sends up messages with
2031 * nlmsg_len set to the payload length rather than the entire
2032 * message length. This breaks the standard set by netlink.
2033 * The existing auditd daemon assumes this breakage. Fixing
2034 * this would require co-ordinating a change in the established
2035 * protocol between the kaudit kernel subsystem and the auditd
2036 * userspace code.
2037 */
Richard Guy Briggs54e05ed2014-08-21 13:40:41 -04002038 nlh->nlmsg_len -= NLMSG_HDRLEN;
Eric Parisf3d357b2008-04-18 10:02:28 -04002039
David Woodhouseb7d11252005-05-19 10:56:58 +01002040 if (audit_pid) {
David Woodhouseb7d11252005-05-19 10:56:58 +01002041 skb_queue_tail(&audit_skb_queue, ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01002042 wake_up_interruptible(&kauditd_wait);
Eric Parisf3d357b2008-04-18 10:02:28 -04002043 } else {
Eric Paris038cbcf2009-06-11 14:31:35 -04002044 audit_printk_skb(ab->skb);
David Woodhouseb7d11252005-05-19 10:56:58 +01002045 }
Eric Parisf3d357b2008-04-18 10:02:28 -04002046 ab->skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002047 }
Chris Wright16e19042005-05-06 15:53:34 +01002048 audit_buffer_free(ab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002049}
2050
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002051/**
2052 * audit_log - Log an audit record
2053 * @ctx: audit context
2054 * @gfp_mask: type of allocation
2055 * @type: audit message type
2056 * @fmt: format string to use
2057 * @...: variable parameters matching the format string
2058 *
2059 * This is a convenience function that calls audit_log_start,
2060 * audit_log_vformat, and audit_log_end. It may be called
2061 * in any context.
2062 */
Daniel Walker5600b892007-10-18 03:06:10 -07002063void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01002064 const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002065{
2066 struct audit_buffer *ab;
2067 va_list args;
2068
David Woodhouse9ad9ad32005-06-22 15:04:33 +01002069 ab = audit_log_start(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002070 if (ab) {
2071 va_start(args, fmt);
2072 audit_log_vformat(ab, fmt, args);
2073 va_end(args);
2074 audit_log_end(ab);
2075 }
2076}
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01002077
Mr Dash Four131ad622011-06-30 13:31:57 +02002078#ifdef CONFIG_SECURITY
2079/**
2080 * audit_log_secctx - Converts and logs SELinux context
2081 * @ab: audit_buffer
2082 * @secid: security number
2083 *
2084 * This is a helper function that calls security_secid_to_secctx to convert
2085 * secid to secctx and then adds the (converted) SELinux context to the audit
2086 * log by calling audit_log_format, thus also preventing leak of internal secid
2087 * to userspace. If secid cannot be converted audit_panic is called.
2088 */
2089void audit_log_secctx(struct audit_buffer *ab, u32 secid)
2090{
2091 u32 len;
2092 char *secctx;
2093
2094 if (security_secid_to_secctx(secid, &secctx, &len)) {
2095 audit_panic("Cannot convert secid to context");
2096 } else {
2097 audit_log_format(ab, " obj=%s", secctx);
2098 security_release_secctx(secctx, len);
2099 }
2100}
2101EXPORT_SYMBOL(audit_log_secctx);
2102#endif
2103
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01002104EXPORT_SYMBOL(audit_log_start);
2105EXPORT_SYMBOL(audit_log_end);
2106EXPORT_SYMBOL(audit_log_format);
2107EXPORT_SYMBOL(audit_log);