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Thomas Gleixner1a59d1b82019-05-27 08:55:05 +02001// SPDX-License-Identifier: GPL-2.0-or-later
85c87212005-04-29 16:23:29 +01002/* audit.c -- Auditing support
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
4 * System-call specific features have moved to auditsc.c
5 *
Steve Grubb6a01b07f2007-01-19 14:39:55 -05006 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * All Rights Reserved.
8 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * Written by Rickard E. (Rik) Faith <faith@redhat.com>
10 *
Ahmed S. Darwishd7a96f32008-03-01 22:01:11 +020011 * Goals: 1) Integrate fully with Security Modules.
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 * 2) Minimal run-time overhead:
13 * a) Minimal when syscall auditing is disabled (audit_enable=0).
14 * b) Small when syscall auditing is enabled and no audit record
15 * is generated (defer as much work as possible to record
16 * generation time):
17 * i) context is allocated,
18 * ii) names from getname are stored without a copy, and
19 * iii) inode information stored from path_lookup.
20 * 3) Ability to disable syscall auditing at boot time (audit=0).
21 * 4) Usable by other parts of the kernel (if audit_log* is called,
22 * then a syscall record will be generated automatically for the
23 * current syscall).
24 * 5) Netlink interface to user-space.
25 * 6) Support low-overhead kernel-based filtering to minimize the
26 * information that must be passed to user-space.
27 *
Richard Guy Briggsd590dca2018-02-03 00:33:11 -050028 * Audit userspace, documentation, tests, and bug/issue trackers:
29 * https://github.com/linux-audit
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 */
31
Joe Perchesd957f7b2014-01-14 10:33:12 -080032#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
Davidlohr Bueso5b282552015-02-22 18:20:09 -080034#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/init.h>
Paul McQuade7153e402014-06-06 14:37:37 -070036#include <linux/types.h>
Arun Sharma600634972011-07-26 16:09:06 -070037#include <linux/atomic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <linux/mm.h>
Paul Gortmaker9984de12011-05-23 14:51:41 -040039#include <linux/export.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090040#include <linux/slab.h>
David Woodhouseb7d11252005-05-19 10:56:58 +010041#include <linux/err.h>
42#include <linux/kthread.h>
Richard Guy Briggs46e959e2013-05-03 14:03:50 -040043#include <linux/kernel.h>
Eric Parisb24a30a2013-04-30 15:30:32 -040044#include <linux/syscalls.h>
Paul Moore5b523302017-03-21 11:26:35 -040045#include <linux/spinlock.h>
46#include <linux/rcupdate.h>
47#include <linux/mutex.h>
48#include <linux/gfp.h>
Paul Mooreb6c7c112017-05-02 10:16:05 -040049#include <linux/pid.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
51#include <linux/audit.h>
52
53#include <net/sock.h>
Amy Griffis93315ed2006-02-07 12:05:27 -050054#include <net/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#include <linux/skbuff.h>
Mr Dash Four131ad622011-06-30 13:31:57 +020056#include <linux/security.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080057#include <linux/freezer.h>
Eric W. Biederman34e36d8e2012-09-10 23:20:20 -070058#include <linux/pid_namespace.h>
Richard Guy Briggs33faba72013-07-16 13:18:45 -040059#include <net/netns/generic.h>
Darrel Goeddel3dc7e312006-03-10 18:14:06 -060060
61#include "audit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
Eric Parisa3f07112008-11-05 12:47:09 -050063/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 * (Initialization happens after skb_init is called.) */
Eric Parisa3f07112008-11-05 12:47:09 -050065#define AUDIT_DISABLED -1
66#define AUDIT_UNINITIALIZED 0
67#define AUDIT_INITIALIZED 1
Alex Shiba59eae72020-11-06 16:31:22 +080068static int audit_initialized = AUDIT_UNINITIALIZED;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Paul Moore173743d2017-09-01 09:44:34 -040070u32 audit_enabled = AUDIT_OFF;
Paul Mooreb3b4fdf2017-09-01 09:44:57 -040071bool audit_ever_enabled = !!AUDIT_OFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
Jan Engelhardtae9d67af2011-01-18 06:48:12 +010073EXPORT_SYMBOL_GPL(audit_enabled);
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075/* Default state when kernel boots without any parameters. */
Paul Moore173743d2017-09-01 09:44:34 -040076static u32 audit_default = AUDIT_OFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78/* If auditing cannot proceed, audit_failure selects what happens. */
Joe Perches3e1d0bb2014-01-14 10:33:13 -080079static u32 audit_failure = AUDIT_FAIL_PRINTK;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Paul Moore5b523302017-03-21 11:26:35 -040081/* private audit network namespace index */
82static unsigned int audit_net_id;
83
84/**
85 * struct audit_net - audit private network namespace data
86 * @sk: communication socket
Pavel Emelyanov75c03712008-03-20 15:39:41 -070087 */
Paul Moore5b523302017-03-21 11:26:35 -040088struct audit_net {
89 struct sock *sk;
90};
91
92/**
93 * struct auditd_connection - kernel/auditd connection state
94 * @pid: auditd PID
95 * @portid: netlink portid
96 * @net: the associated network namespace
Paul Moore48d0e022017-05-02 10:16:05 -040097 * @rcu: RCU head
Paul Moore5b523302017-03-21 11:26:35 -040098 *
99 * Description:
100 * This struct is RCU protected; you must either hold the RCU lock for reading
Paul Moore48d0e022017-05-02 10:16:05 -0400101 * or the associated spinlock for writing.
Paul Moore5b523302017-03-21 11:26:35 -0400102 */
Amol Grovercb5172d2019-12-02 00:03:48 +0530103struct auditd_connection {
Paul Mooreb6c7c112017-05-02 10:16:05 -0400104 struct pid *pid;
Paul Moore5b523302017-03-21 11:26:35 -0400105 u32 portid;
106 struct net *net;
Paul Moore48d0e022017-05-02 10:16:05 -0400107 struct rcu_head rcu;
Amol Grovercb5172d2019-12-02 00:03:48 +0530108};
109static struct auditd_connection __rcu *auditd_conn;
Paul Moore48d0e022017-05-02 10:16:05 -0400110static DEFINE_SPINLOCK(auditd_conn_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700112/* If audit_rate_limit is non-zero, limit the rate of sending audit records
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 * to that number per second. This prevents DoS attacks, but results in
114 * audit records being dropped. */
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800115static u32 audit_rate_limit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Richard Guy Briggs40c07752013-10-22 13:28:49 -0400117/* Number of outstanding audit_buffers allowed.
118 * When set to zero, this means unlimited. */
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800119static u32 audit_backlog_limit = 64;
Richard Guy Briggse789e562013-09-12 23:03:51 -0400120#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800121static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100123/* The identity of the user shutting down the audit system. */
Jules Irenge6b870242020-08-03 13:34:38 +0100124static kuid_t audit_sig_uid = INVALID_UID;
125static pid_t audit_sig_pid = -1;
Jules Irenge265c3202020-08-03 13:34:39 +0100126static u32 audit_sig_sid;
Steve Grubbc2f0c7c2005-05-06 12:38:39 +0100127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128/* Records can be lost in several ways:
129 0) [suppressed in audit_alloc]
130 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
131 2) out of memory in audit_log_move [alloc_skb]
132 3) suppressed due to audit_rate_limit
133 4) suppressed due to audit_backlog_limit
134*/
Richard Guy Briggs92c82e82017-01-13 03:26:29 -0500135static atomic_t audit_lost = ATOMIC_INIT(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
Max Englanderb43870c2020-07-04 15:15:28 +0000137/* Monotonically increasing sum of time the kernel has spent
138 * waiting while the backlog limit is exceeded.
139 */
140static atomic_t audit_backlog_wait_time_actual = ATOMIC_INIT(0);
141
Amy Griffisf368c07d2006-04-07 16:55:56 -0400142/* Hash for inode-based rules */
143struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
144
Paul Moore8cc96382017-05-02 10:16:05 -0400145static struct kmem_cache *audit_buffer_cache;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146
Paul Moorec6480202016-11-29 16:53:25 -0500147/* queue msgs to send via kauditd_task */
Paul Mooreaf8b8242016-11-29 16:53:24 -0500148static struct sk_buff_head audit_queue;
Paul Moorec6480202016-11-29 16:53:25 -0500149/* queue msgs due to temporary unicast send problems */
150static struct sk_buff_head audit_retry_queue;
151/* queue msgs waiting for new auditd connection */
Paul Mooreaf8b8242016-11-29 16:53:24 -0500152static struct sk_buff_head audit_hold_queue;
Paul Moorec6480202016-11-29 16:53:25 -0500153
154/* queue servicing thread */
David Woodhouseb7d11252005-05-19 10:56:58 +0100155static struct task_struct *kauditd_task;
156static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
Paul Moorec6480202016-11-29 16:53:25 -0500157
158/* waitqueue for callers who are blocked on the audit backlog */
David Woodhouse9ad9ad32005-06-22 15:04:33 +0100159static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160
Eric Parisb0fed402013-05-22 12:54:49 -0400161static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
162 .mask = -1,
163 .features = 0,
164 .lock = 0,};
165
Eric Paris21b85c32013-05-23 14:26:00 -0400166static char *audit_feature_names[2] = {
Eric Parisd040e5a2013-05-24 09:18:04 -0400167 "only_unset_loginuid",
Eric Paris21b85c32013-05-23 14:26:00 -0400168 "loginuid_immutable",
Eric Parisb0fed402013-05-22 12:54:49 -0400169};
170
Paul Moorece4236312018-02-20 09:52:38 -0500171/**
172 * struct audit_ctl_mutex - serialize requests from userspace
173 * @lock: the mutex used for locking
174 * @owner: the task which owns the lock
175 *
176 * Description:
177 * This is the lock struct used to ensure we only process userspace requests
178 * in an orderly fashion. We can't simply use a mutex/lock here because we
179 * need to track lock ownership so we don't end up blocking the lock owner in
180 * audit_log_start() or similar.
181 */
182static struct audit_ctl_mutex {
183 struct mutex lock;
184 void *owner;
185} audit_cmd_mutex;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
187/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
188 * audit records. Since printk uses a 1024 byte buffer, this buffer
189 * should be at least that large. */
190#define AUDIT_BUFSIZ 1024
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192/* The audit_buffer is used when formatting an audit record. The caller
193 * locks briefly to get the record off the freelist or to allocate the
194 * buffer, and locks briefly to send the buffer to the netlink layer or
195 * to place it on a transmit queue. Multiple audit_buffers can be in
196 * use simultaneously. */
197struct audit_buffer {
Chris Wright8fc61152005-05-06 15:54:17 +0100198 struct sk_buff *skb; /* formatted skb ready to send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 struct audit_context *ctx; /* NULL or associated context */
Al Viro9796fdd2005-10-21 03:22:03 -0400200 gfp_t gfp_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201};
202
Eric Parisf09ac9d2008-04-18 10:11:04 -0400203struct audit_reply {
Richard Guy Briggsf9441632013-08-14 11:32:45 -0400204 __u32 portid;
Eric W. Biederman638a0fd2014-02-28 10:49:05 -0800205 struct net *net;
Eric Parisf09ac9d2008-04-18 10:11:04 -0400206 struct sk_buff *skb;
207};
208
Paul Moore5b523302017-03-21 11:26:35 -0400209/**
210 * auditd_test_task - Check to see if a given task is an audit daemon
211 * @task: the task to check
212 *
213 * Description:
214 * Return 1 if the task is a registered audit daemon, 0 otherwise.
215 */
Paul Mooreb6c7c112017-05-02 10:16:05 -0400216int auditd_test_task(struct task_struct *task)
Paul Moore5b523302017-03-21 11:26:35 -0400217{
218 int rc;
Paul Moore48d0e022017-05-02 10:16:05 -0400219 struct auditd_connection *ac;
Paul Moore5b523302017-03-21 11:26:35 -0400220
221 rcu_read_lock();
Paul Moore48d0e022017-05-02 10:16:05 -0400222 ac = rcu_dereference(auditd_conn);
223 rc = (ac && ac->pid == task_tgid(task) ? 1 : 0);
Paul Moore5b523302017-03-21 11:26:35 -0400224 rcu_read_unlock();
225
226 return rc;
227}
228
229/**
Paul Moorece4236312018-02-20 09:52:38 -0500230 * audit_ctl_lock - Take the audit control lock
231 */
232void audit_ctl_lock(void)
233{
234 mutex_lock(&audit_cmd_mutex.lock);
235 audit_cmd_mutex.owner = current;
236}
237
238/**
239 * audit_ctl_unlock - Drop the audit control lock
240 */
241void audit_ctl_unlock(void)
242{
243 audit_cmd_mutex.owner = NULL;
244 mutex_unlock(&audit_cmd_mutex.lock);
245}
246
247/**
248 * audit_ctl_owner_current - Test to see if the current task owns the lock
249 *
250 * Description:
251 * Return true if the current task owns the audit control lock, false if it
252 * doesn't own the lock.
253 */
254static bool audit_ctl_owner_current(void)
255{
256 return (current == audit_cmd_mutex.owner);
257}
258
259/**
Paul Mooreb6c7c112017-05-02 10:16:05 -0400260 * auditd_pid_vnr - Return the auditd PID relative to the namespace
Paul Mooreb6c7c112017-05-02 10:16:05 -0400261 *
262 * Description:
Paul Moore48d0e022017-05-02 10:16:05 -0400263 * Returns the PID in relation to the namespace, 0 on failure.
Paul Mooreb6c7c112017-05-02 10:16:05 -0400264 */
Paul Moore48d0e022017-05-02 10:16:05 -0400265static pid_t auditd_pid_vnr(void)
Paul Mooreb6c7c112017-05-02 10:16:05 -0400266{
267 pid_t pid;
Paul Moore48d0e022017-05-02 10:16:05 -0400268 const struct auditd_connection *ac;
Paul Mooreb6c7c112017-05-02 10:16:05 -0400269
270 rcu_read_lock();
Paul Moore48d0e022017-05-02 10:16:05 -0400271 ac = rcu_dereference(auditd_conn);
272 if (!ac || !ac->pid)
Paul Mooreb6c7c112017-05-02 10:16:05 -0400273 pid = 0;
274 else
Paul Moore48d0e022017-05-02 10:16:05 -0400275 pid = pid_vnr(ac->pid);
Paul Mooreb6c7c112017-05-02 10:16:05 -0400276 rcu_read_unlock();
277
278 return pid;
279}
280
281/**
Paul Moore5b523302017-03-21 11:26:35 -0400282 * audit_get_sk - Return the audit socket for the given network namespace
283 * @net: the destination network namespace
284 *
285 * Description:
286 * Returns the sock pointer if valid, NULL otherwise. The caller must ensure
287 * that a reference is held for the network namespace while the sock is in use.
288 */
289static struct sock *audit_get_sk(const struct net *net)
290{
291 struct audit_net *aunet;
292
293 if (!net)
294 return NULL;
295
296 aunet = net_generic(net, audit_net_id);
297 return aunet->sk;
298}
299
Dustin Kirkland8c8570f2005-11-03 17:15:16 +0000300void audit_panic(const char *message)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
Joe Perchesd957f7b2014-01-14 10:33:12 -0800302 switch (audit_failure) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 case AUDIT_FAIL_SILENT:
304 break;
305 case AUDIT_FAIL_PRINTK:
Eric Paris320f1b12008-01-23 22:55:05 -0500306 if (printk_ratelimit())
Joe Perchesd957f7b2014-01-14 10:33:12 -0800307 pr_err("%s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 break;
309 case AUDIT_FAIL_PANIC:
Paul Moore5b523302017-03-21 11:26:35 -0400310 panic("audit: %s\n", message);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 break;
312 }
313}
314
315static inline int audit_rate_check(void)
316{
317 static unsigned long last_check = 0;
318 static int messages = 0;
319 static DEFINE_SPINLOCK(lock);
320 unsigned long flags;
321 unsigned long now;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 int retval = 0;
323
Atul Kumar Pantb1a0f642023-08-16 02:17:51 +0530324 if (!audit_rate_limit)
325 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326
327 spin_lock_irqsave(&lock, flags);
328 if (++messages < audit_rate_limit) {
329 retval = 1;
330 } else {
wuchi501e4bb2022-08-30 00:26:09 +0800331 now = jiffies;
332 if (time_after(now, last_check + HZ)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 last_check = now;
334 messages = 0;
335 retval = 1;
336 }
337 }
338 spin_unlock_irqrestore(&lock, flags);
339
340 return retval;
341}
342
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700343/**
344 * audit_log_lost - conditionally log lost audit message event
345 * @message: the message stating reason for lost audit message
346 *
347 * Emit at least 1 message per second, even if audit_rate_check is
348 * throttling.
349 * Always increment the lost messages counter.
350*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351void audit_log_lost(const char *message)
352{
353 static unsigned long last_msg = 0;
354 static DEFINE_SPINLOCK(lock);
355 unsigned long flags;
356 unsigned long now;
357 int print;
358
359 atomic_inc(&audit_lost);
360
361 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
362
363 if (!print) {
364 spin_lock_irqsave(&lock, flags);
365 now = jiffies;
wuchi501e4bb2022-08-30 00:26:09 +0800366 if (time_after(now, last_msg + HZ)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 print = 1;
368 last_msg = now;
369 }
370 spin_unlock_irqrestore(&lock, flags);
371 }
372
373 if (print) {
Eric Paris320f1b12008-01-23 22:55:05 -0500374 if (printk_ratelimit())
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800375 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
Eric Paris320f1b12008-01-23 22:55:05 -0500376 atomic_read(&audit_lost),
377 audit_rate_limit,
378 audit_backlog_limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 audit_panic(message);
380 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381}
382
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800383static int audit_log_config_change(char *function_name, u32 new, u32 old,
Eric Paris25323862008-04-18 10:09:25 -0400384 int allow_changes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385{
Eric Paris1a6b9f22008-01-07 17:09:31 -0500386 struct audit_buffer *ab;
387 int rc = 0;
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500388
Richard Guy Briggs626abcd2019-01-18 17:42:48 -0500389 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
Kees Cook0644ec02013-01-11 14:32:07 -0800390 if (unlikely(!ab))
391 return rc;
Richard Guy Briggs53fc7a02018-12-10 17:17:48 -0500392 audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old);
Eric Paris4d3fb702013-04-30 09:53:34 -0400393 audit_log_session_info(ab);
Eric Parisb122c372013-04-19 15:00:33 -0400394 rc = audit_log_task_context(ab);
395 if (rc)
396 allow_changes = 0; /* Something weird, deny request */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500397 audit_log_format(ab, " res=%d", allow_changes);
398 audit_log_end(ab);
399 return rc;
400}
401
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800402static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500403{
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800404 int allow_changes, rc = 0;
405 u32 old = *to_change;
Eric Paris1a6b9f22008-01-07 17:09:31 -0500406
407 /* check if we are locked */
408 if (audit_enabled == AUDIT_LOCKED)
409 allow_changes = 0;
410 else
411 allow_changes = 1;
412
413 if (audit_enabled != AUDIT_OFF) {
Eric Parisdc9eb692013-04-19 13:23:09 -0400414 rc = audit_log_config_change(function_name, new, old, allow_changes);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500415 if (rc)
416 allow_changes = 0;
417 }
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500418
419 /* If we are allowed, make the change */
Eric Paris1a6b9f22008-01-07 17:09:31 -0500420 if (allow_changes == 1)
421 *to_change = new;
Steve Grubb6a01b07f2007-01-19 14:39:55 -0500422 /* Not allowed, update reason */
423 else if (rc == 0)
424 rc = -EPERM;
425 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426}
427
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800428static int audit_set_rate_limit(u32 limit)
Eric Paris1a6b9f22008-01-07 17:09:31 -0500429{
Eric Parisdc9eb692013-04-19 13:23:09 -0400430 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
Eric Paris1a6b9f22008-01-07 17:09:31 -0500431}
432
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800433static int audit_set_backlog_limit(u32 limit)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434{
Eric Parisdc9eb692013-04-19 13:23:09 -0400435 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436}
437
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800438static int audit_set_backlog_wait_time(u32 timeout)
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -0400439{
440 return audit_do_config_change("audit_backlog_wait_time",
Paul Moore31975422016-11-29 16:53:25 -0500441 &audit_backlog_wait_time, timeout);
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -0400442}
443
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800444static int audit_set_enabled(u32 state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445{
Eric Parisb593d382008-01-08 17:38:31 -0500446 int rc;
Pranith Kumar724e7bf2015-03-11 14:08:19 -0400447 if (state > AUDIT_LOCKED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500449
Eric Parisdc9eb692013-04-19 13:23:09 -0400450 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
Eric Parisb593d382008-01-08 17:38:31 -0500451 if (!rc)
452 audit_ever_enabled |= !!state;
453
454 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455}
456
Joe Perches3e1d0bb2014-01-14 10:33:13 -0800457static int audit_set_failure(u32 state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 if (state != AUDIT_FAIL_SILENT
460 && state != AUDIT_FAIL_PRINTK
461 && state != AUDIT_FAIL_PANIC)
462 return -EINVAL;
Steve Grubbce29b682006-04-01 18:29:34 -0500463
Eric Parisdc9eb692013-04-19 13:23:09 -0400464 return audit_do_config_change("audit_failure", &audit_failure, state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465}
466
Paul Moore5b523302017-03-21 11:26:35 -0400467/**
Paul Moore48d0e022017-05-02 10:16:05 -0400468 * auditd_conn_free - RCU helper to release an auditd connection struct
469 * @rcu: RCU head
470 *
471 * Description:
472 * Drop any references inside the auditd connection tracking struct and free
473 * the memory.
474 */
Joe Perches447a5642018-03-21 15:09:32 -0700475static void auditd_conn_free(struct rcu_head *rcu)
476{
Paul Moore48d0e022017-05-02 10:16:05 -0400477 struct auditd_connection *ac;
478
479 ac = container_of(rcu, struct auditd_connection, rcu);
480 put_pid(ac->pid);
481 put_net(ac->net);
482 kfree(ac);
Joe Perches447a5642018-03-21 15:09:32 -0700483}
Paul Moore48d0e022017-05-02 10:16:05 -0400484
485/**
Paul Moore5b523302017-03-21 11:26:35 -0400486 * auditd_set - Set/Reset the auditd connection state
487 * @pid: auditd PID
488 * @portid: auditd netlink portid
489 * @net: auditd network namespace pointer
Chris Riches022732e2023-10-18 09:23:51 +0000490 * @skb: the netlink command from the audit daemon
491 * @ack: netlink ack flag, cleared if ack'd here
Paul Moore5b523302017-03-21 11:26:35 -0400492 *
493 * Description:
494 * This function will obtain and drop network namespace references as
Paul Moore48d0e022017-05-02 10:16:05 -0400495 * necessary. Returns zero on success, negative values on failure.
Paul Moore5b523302017-03-21 11:26:35 -0400496 */
Chris Riches022732e2023-10-18 09:23:51 +0000497static int auditd_set(struct pid *pid, u32 portid, struct net *net,
498 struct sk_buff *skb, bool *ack)
Paul Moore5b523302017-03-21 11:26:35 -0400499{
500 unsigned long flags;
Paul Moore48d0e022017-05-02 10:16:05 -0400501 struct auditd_connection *ac_old, *ac_new;
Chris Riches022732e2023-10-18 09:23:51 +0000502 struct nlmsghdr *nlh;
Paul Moore5b523302017-03-21 11:26:35 -0400503
Paul Moore48d0e022017-05-02 10:16:05 -0400504 if (!pid || !net)
505 return -EINVAL;
506
507 ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL);
508 if (!ac_new)
509 return -ENOMEM;
510 ac_new->pid = get_pid(pid);
511 ac_new->portid = portid;
512 ac_new->net = get_net(net);
513
Chris Riches022732e2023-10-18 09:23:51 +0000514 /* send the ack now to avoid a race with the queue backlog */
515 if (*ack) {
516 nlh = nlmsg_hdr(skb);
517 netlink_ack(skb, nlh, 0, NULL);
518 *ack = false;
519 }
520
Paul Moore48d0e022017-05-02 10:16:05 -0400521 spin_lock_irqsave(&auditd_conn_lock, flags);
522 ac_old = rcu_dereference_protected(auditd_conn,
523 lockdep_is_held(&auditd_conn_lock));
524 rcu_assign_pointer(auditd_conn, ac_new);
525 spin_unlock_irqrestore(&auditd_conn_lock, flags);
526
527 if (ac_old)
528 call_rcu(&ac_old->rcu, auditd_conn_free);
529
530 return 0;
Paul Moore5b523302017-03-21 11:26:35 -0400531}
532
533/**
Mauro Carvalho Chehabcbb52622020-10-23 18:33:38 +0200534 * kauditd_printk_skb - Print the audit record to the ring buffer
Paul Moore5b523302017-03-21 11:26:35 -0400535 * @skb: audit record
536 *
537 * Whatever the reason, this packet may not make it to the auditd connection
538 * so write it via printk so the information isn't completely lost.
Eric Paris038cbcf2009-06-11 14:31:35 -0400539 */
Paul Mooreaf8b8242016-11-29 16:53:24 -0500540static void kauditd_printk_skb(struct sk_buff *skb)
Eric Paris038cbcf2009-06-11 14:31:35 -0400541{
542 struct nlmsghdr *nlh = nlmsg_hdr(skb);
David S. Millerc64e66c2012-06-26 21:45:21 -0700543 char *data = nlmsg_data(nlh);
Eric Paris038cbcf2009-06-11 14:31:35 -0400544
Paul Moore5b523302017-03-21 11:26:35 -0400545 if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit())
546 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
547}
548
549/**
550 * kauditd_rehold_skb - Handle a audit record send failure in the hold queue
551 * @skb: audit record
Paul Mooref26d0432022-01-13 18:54:38 -0500552 * @error: error code (unused)
Paul Moore5b523302017-03-21 11:26:35 -0400553 *
554 * Description:
555 * This should only be used by the kauditd_thread when it fails to flush the
556 * hold queue.
557 */
Paul Mooref26d0432022-01-13 18:54:38 -0500558static void kauditd_rehold_skb(struct sk_buff *skb, __always_unused int error)
Paul Moore5b523302017-03-21 11:26:35 -0400559{
Paul Mooref26d0432022-01-13 18:54:38 -0500560 /* put the record back in the queue */
561 skb_queue_tail(&audit_hold_queue, skb);
Eric Paris038cbcf2009-06-11 14:31:35 -0400562}
563
Paul Moorec6480202016-11-29 16:53:25 -0500564/**
565 * kauditd_hold_skb - Queue an audit record, waiting for auditd
566 * @skb: audit record
Paul Mooref26d0432022-01-13 18:54:38 -0500567 * @error: error code
Paul Moorec6480202016-11-29 16:53:25 -0500568 *
569 * Description:
570 * Queue the audit record, waiting for an instance of auditd. When this
571 * function is called we haven't given up yet on sending the record, but things
572 * are not looking good. The first thing we want to do is try to write the
573 * record via printk and then see if we want to try and hold on to the record
574 * and queue it, if we have room. If we want to hold on to the record, but we
575 * don't have room, record a record lost message.
576 */
Paul Mooref26d0432022-01-13 18:54:38 -0500577static void kauditd_hold_skb(struct sk_buff *skb, int error)
Eric Parisf3d357b2008-04-18 10:02:28 -0400578{
Paul Moorec6480202016-11-29 16:53:25 -0500579 /* at this point it is uncertain if we will ever send this to auditd so
580 * try to send the message via printk before we go any further */
581 kauditd_printk_skb(skb);
Richard Guy Briggs32a1dba2015-11-04 08:23:50 -0500582
Paul Moorec6480202016-11-29 16:53:25 -0500583 /* can we just silently drop the message? */
Paul Mooref26d0432022-01-13 18:54:38 -0500584 if (!audit_default)
585 goto drop;
586
587 /* the hold queue is only for when the daemon goes away completely,
588 * not -EAGAIN failures; if we are in a -EAGAIN state requeue the
589 * record on the retry queue unless it's full, in which case drop it
590 */
591 if (error == -EAGAIN) {
592 if (!audit_backlog_limit ||
593 skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
594 skb_queue_tail(&audit_retry_queue, skb);
595 return;
596 }
597 audit_log_lost("kauditd retry queue overflow");
598 goto drop;
Paul Moorec6480202016-11-29 16:53:25 -0500599 }
600
Paul Mooref26d0432022-01-13 18:54:38 -0500601 /* if we have room in the hold queue, queue the message */
Paul Moorec6480202016-11-29 16:53:25 -0500602 if (!audit_backlog_limit ||
603 skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
604 skb_queue_tail(&audit_hold_queue, skb);
605 return;
606 }
607
608 /* we have no other options - drop the message */
609 audit_log_lost("kauditd hold queue overflow");
Paul Mooref26d0432022-01-13 18:54:38 -0500610drop:
Paul Moorec6480202016-11-29 16:53:25 -0500611 kfree_skb(skb);
612}
613
614/**
615 * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
616 * @skb: audit record
Paul Mooref26d0432022-01-13 18:54:38 -0500617 * @error: error code (unused)
Paul Moorec6480202016-11-29 16:53:25 -0500618 *
619 * Description:
620 * Not as serious as kauditd_hold_skb() as we still have a connected auditd,
621 * but for some reason we are having problems sending it audit records so
622 * queue the given record and attempt to resend.
623 */
Paul Mooref26d0432022-01-13 18:54:38 -0500624static void kauditd_retry_skb(struct sk_buff *skb, __always_unused int error)
Paul Moorec6480202016-11-29 16:53:25 -0500625{
Paul Mooref26d0432022-01-13 18:54:38 -0500626 if (!audit_backlog_limit ||
627 skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
628 skb_queue_tail(&audit_retry_queue, skb);
629 return;
630 }
631
632 /* we have to drop the record, send it via printk as a last effort */
633 kauditd_printk_skb(skb);
634 audit_log_lost("kauditd retry queue overflow");
635 kfree_skb(skb);
Paul Moorec6480202016-11-29 16:53:25 -0500636}
637
638/**
Paul Moore264d5092017-04-10 11:16:59 -0400639 * auditd_reset - Disconnect the auditd connection
Paul Moorec81be522017-06-12 09:35:24 -0400640 * @ac: auditd connection state
Paul Moore264d5092017-04-10 11:16:59 -0400641 *
642 * Description:
643 * Break the auditd/kauditd connection and move all the queued records into the
Paul Moorec81be522017-06-12 09:35:24 -0400644 * hold queue in case auditd reconnects. It is important to note that the @ac
645 * pointer should never be dereferenced inside this function as it may be NULL
646 * or invalid, you can only compare the memory address! If @ac is NULL then
647 * the connection will always be reset.
Paul Moore264d5092017-04-10 11:16:59 -0400648 */
Paul Moorec81be522017-06-12 09:35:24 -0400649static void auditd_reset(const struct auditd_connection *ac)
Paul Moore264d5092017-04-10 11:16:59 -0400650{
Paul Moore48d0e022017-05-02 10:16:05 -0400651 unsigned long flags;
Paul Moore264d5092017-04-10 11:16:59 -0400652 struct sk_buff *skb;
Paul Moore48d0e022017-05-02 10:16:05 -0400653 struct auditd_connection *ac_old;
Paul Moore264d5092017-04-10 11:16:59 -0400654
655 /* if it isn't already broken, break the connection */
Paul Moore48d0e022017-05-02 10:16:05 -0400656 spin_lock_irqsave(&auditd_conn_lock, flags);
657 ac_old = rcu_dereference_protected(auditd_conn,
658 lockdep_is_held(&auditd_conn_lock));
Paul Moorec81be522017-06-12 09:35:24 -0400659 if (ac && ac != ac_old) {
660 /* someone already registered a new auditd connection */
661 spin_unlock_irqrestore(&auditd_conn_lock, flags);
662 return;
663 }
Paul Moore48d0e022017-05-02 10:16:05 -0400664 rcu_assign_pointer(auditd_conn, NULL);
665 spin_unlock_irqrestore(&auditd_conn_lock, flags);
666
667 if (ac_old)
668 call_rcu(&ac_old->rcu, auditd_conn_free);
Paul Moore264d5092017-04-10 11:16:59 -0400669
Paul Moorecd33f5f2017-06-12 11:53:09 -0400670 /* flush the retry queue to the hold queue, but don't touch the main
671 * queue since we need to process that normally for multicast */
Paul Moore264d5092017-04-10 11:16:59 -0400672 while ((skb = skb_dequeue(&audit_retry_queue)))
Paul Mooref26d0432022-01-13 18:54:38 -0500673 kauditd_hold_skb(skb, -ECONNREFUSED);
Paul Moore264d5092017-04-10 11:16:59 -0400674}
675
676/**
Paul Moore5b523302017-03-21 11:26:35 -0400677 * auditd_send_unicast_skb - Send a record via unicast to auditd
678 * @skb: audit record
Paul Moorec6480202016-11-29 16:53:25 -0500679 *
680 * Description:
Paul Moore5b523302017-03-21 11:26:35 -0400681 * Send a skb to the audit daemon, returns positive/zero values on success and
682 * negative values on failure; in all cases the skb will be consumed by this
683 * function. If the send results in -ECONNREFUSED the connection with auditd
684 * will be reset. This function may sleep so callers should not hold any locks
685 * where this would cause a problem.
Paul Moorec6480202016-11-29 16:53:25 -0500686 */
Paul Moore5b523302017-03-21 11:26:35 -0400687static int auditd_send_unicast_skb(struct sk_buff *skb)
Paul Moorec6480202016-11-29 16:53:25 -0500688{
Paul Moore5b523302017-03-21 11:26:35 -0400689 int rc;
690 u32 portid;
691 struct net *net;
692 struct sock *sk;
Paul Moore48d0e022017-05-02 10:16:05 -0400693 struct auditd_connection *ac;
Paul Moorec6480202016-11-29 16:53:25 -0500694
Paul Moore5b523302017-03-21 11:26:35 -0400695 /* NOTE: we can't call netlink_unicast while in the RCU section so
696 * take a reference to the network namespace and grab local
697 * copies of the namespace, the sock, and the portid; the
698 * namespace and sock aren't going to go away while we hold a
699 * reference and if the portid does become invalid after the RCU
700 * section netlink_unicast() should safely return an error */
701
702 rcu_read_lock();
Paul Moore48d0e022017-05-02 10:16:05 -0400703 ac = rcu_dereference(auditd_conn);
704 if (!ac) {
Paul Moore5b523302017-03-21 11:26:35 -0400705 rcu_read_unlock();
Shu Wangb0659ae2017-07-18 14:37:24 +0800706 kfree_skb(skb);
Paul Moore5b523302017-03-21 11:26:35 -0400707 rc = -ECONNREFUSED;
708 goto err;
Richard Guy Briggs533c7b62016-12-13 10:03:01 -0500709 }
Paul Moore48d0e022017-05-02 10:16:05 -0400710 net = get_net(ac->net);
Paul Moore5b523302017-03-21 11:26:35 -0400711 sk = audit_get_sk(net);
Paul Moore48d0e022017-05-02 10:16:05 -0400712 portid = ac->portid;
Paul Moore5b523302017-03-21 11:26:35 -0400713 rcu_read_unlock();
Paul Moorec6480202016-11-29 16:53:25 -0500714
Paul Moore5b523302017-03-21 11:26:35 -0400715 rc = netlink_unicast(sk, skb, portid, 0);
716 put_net(net);
717 if (rc < 0)
718 goto err;
719
720 return rc;
721
722err:
Paul Moorec81be522017-06-12 09:35:24 -0400723 if (ac && rc == -ECONNREFUSED)
724 auditd_reset(ac);
Paul Moore5b523302017-03-21 11:26:35 -0400725 return rc;
Paul Moorec6480202016-11-29 16:53:25 -0500726}
727
728/**
Paul Moore5b523302017-03-21 11:26:35 -0400729 * kauditd_send_queue - Helper for kauditd_thread to flush skb queues
730 * @sk: the sending sock
731 * @portid: the netlink destination
732 * @queue: the skb queue to process
733 * @retry_limit: limit on number of netlink unicast failures
734 * @skb_hook: per-skb hook for additional processing
735 * @err_hook: hook called if the skb fails the netlink unicast send
736 *
737 * Description:
738 * Run through the given queue and attempt to send the audit records to auditd,
739 * returns zero on success, negative values on failure. It is up to the caller
740 * to ensure that the @sk is valid for the duration of this function.
741 *
Paul Moorec6480202016-11-29 16:53:25 -0500742 */
Paul Moore5b523302017-03-21 11:26:35 -0400743static int kauditd_send_queue(struct sock *sk, u32 portid,
744 struct sk_buff_head *queue,
745 unsigned int retry_limit,
746 void (*skb_hook)(struct sk_buff *skb),
Paul Mooref26d0432022-01-13 18:54:38 -0500747 void (*err_hook)(struct sk_buff *skb, int error))
Paul Moorec6480202016-11-29 16:53:25 -0500748{
Paul Moore5b523302017-03-21 11:26:35 -0400749 int rc = 0;
Paul Mooref26d0432022-01-13 18:54:38 -0500750 struct sk_buff *skb = NULL;
751 struct sk_buff *skb_tail;
Paul Mooref4b3ee32021-12-09 11:46:07 -0500752 unsigned int failed = 0;
Paul Moorec6480202016-11-29 16:53:25 -0500753
Paul Moore5b523302017-03-21 11:26:35 -0400754 /* NOTE: kauditd_thread takes care of all our locking, we just use
755 * the netlink info passed to us (e.g. sk and portid) */
Paul Moore6c54e782016-11-29 16:53:26 -0500756
Paul Mooref26d0432022-01-13 18:54:38 -0500757 skb_tail = skb_peek_tail(queue);
758 while ((skb != skb_tail) && (skb = skb_dequeue(queue))) {
Paul Moore5b523302017-03-21 11:26:35 -0400759 /* call the skb_hook for each skb we touch */
760 if (skb_hook)
761 (*skb_hook)(skb);
762
763 /* can we send to anyone via unicast? */
764 if (!sk) {
765 if (err_hook)
Paul Mooref26d0432022-01-13 18:54:38 -0500766 (*err_hook)(skb, -ECONNREFUSED);
Paul Moore5b523302017-03-21 11:26:35 -0400767 continue;
768 }
769
Paul Mooref4b3ee32021-12-09 11:46:07 -0500770retry:
Paul Moore5b523302017-03-21 11:26:35 -0400771 /* grab an extra skb reference in case of error */
772 skb_get(skb);
773 rc = netlink_unicast(sk, skb, portid, 0);
774 if (rc < 0) {
Paul Mooref4b3ee32021-12-09 11:46:07 -0500775 /* send failed - try a few times unless fatal error */
Paul Moore5b523302017-03-21 11:26:35 -0400776 if (++failed >= retry_limit ||
777 rc == -ECONNREFUSED || rc == -EPERM) {
Paul Moore5b523302017-03-21 11:26:35 -0400778 sk = NULL;
779 if (err_hook)
Paul Mooref26d0432022-01-13 18:54:38 -0500780 (*err_hook)(skb, rc);
Paul Mooref4b3ee32021-12-09 11:46:07 -0500781 if (rc == -EAGAIN)
782 rc = 0;
783 /* continue to drain the queue */
Paul Moore5b523302017-03-21 11:26:35 -0400784 continue;
785 } else
Paul Mooref4b3ee32021-12-09 11:46:07 -0500786 goto retry;
Paul Moore5b523302017-03-21 11:26:35 -0400787 } else {
Paul Mooref4b3ee32021-12-09 11:46:07 -0500788 /* skb sent - drop the extra reference and continue */
Paul Moore5b523302017-03-21 11:26:35 -0400789 consume_skb(skb);
790 failed = 0;
791 }
Paul Moorec6480202016-11-29 16:53:25 -0500792 }
793
Paul Moore5b523302017-03-21 11:26:35 -0400794 return (rc >= 0 ? 0 : rc);
Eric Parisf3d357b2008-04-18 10:02:28 -0400795}
796
Richard Guy Briggsb551d1d2013-01-24 13:15:10 -0500797/*
Paul Moorec6480202016-11-29 16:53:25 -0500798 * kauditd_send_multicast_skb - Send a record to any multicast listeners
799 * @skb: audit record
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400800 *
Paul Moorec6480202016-11-29 16:53:25 -0500801 * Description:
Paul Moore5b523302017-03-21 11:26:35 -0400802 * Write a multicast message to anyone listening in the initial network
803 * namespace. This function doesn't consume an skb as might be expected since
804 * it has to copy it anyways.
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400805 */
Paul Moorec6480202016-11-29 16:53:25 -0500806static void kauditd_send_multicast_skb(struct sk_buff *skb)
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400807{
Paul Moorec6480202016-11-29 16:53:25 -0500808 struct sk_buff *copy;
Paul Moore5b523302017-03-21 11:26:35 -0400809 struct sock *sock = audit_get_sk(&init_net);
Paul Moorec6480202016-11-29 16:53:25 -0500810 struct nlmsghdr *nlh;
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400811
Paul Moore5b523302017-03-21 11:26:35 -0400812 /* NOTE: we are not taking an additional reference for init_net since
813 * we don't have to worry about it going away */
814
Richard Guy Briggs7f74ecd72014-04-22 21:31:58 -0400815 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
816 return;
817
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400818 /*
819 * The seemingly wasteful skb_copy() rather than bumping the refcount
820 * using skb_get() is necessary because non-standard mods are made to
821 * the skb by the original kaudit unicast socket send routine. The
822 * existing auditd daemon assumes this breakage. Fixing this would
823 * require co-ordinating a change in the established protocol between
824 * the kaudit kernel subsystem and the auditd userspace code. There is
825 * no reason for new multicast clients to continue with this
826 * non-compliance.
827 */
Paul Moorec6480202016-11-29 16:53:25 -0500828 copy = skb_copy(skb, GFP_KERNEL);
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400829 if (!copy)
830 return;
Paul Moorec6480202016-11-29 16:53:25 -0500831 nlh = nlmsg_hdr(copy);
832 nlh->nlmsg_len = skb->len;
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400833
Paul Moorec6480202016-11-29 16:53:25 -0500834 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
Richard Guy Briggs451f9212014-04-22 21:31:57 -0400835}
836
Paul Moorec6480202016-11-29 16:53:25 -0500837/**
Paul Moore5b523302017-03-21 11:26:35 -0400838 * kauditd_thread - Worker thread to send audit records to userspace
839 * @dummy: unused
Richard Guy Briggsb551d1d2013-01-24 13:15:10 -0500840 */
Adrian Bunk97a41e22006-01-08 01:02:17 -0800841static int kauditd_thread(void *dummy)
David Woodhouseb7d11252005-05-19 10:56:58 +0100842{
Paul Moorec6480202016-11-29 16:53:25 -0500843 int rc;
Paul Moore5b523302017-03-21 11:26:35 -0400844 u32 portid = 0;
845 struct net *net = NULL;
846 struct sock *sk = NULL;
Paul Moore48d0e022017-05-02 10:16:05 -0400847 struct auditd_connection *ac;
Paul Moore4aa838722016-11-29 16:53:24 -0500848
Paul Moorec6480202016-11-29 16:53:25 -0500849#define UNICAST_RETRIES 5
Paul Moorec6480202016-11-29 16:53:25 -0500850
Rafael J. Wysocki83144182007-07-17 04:03:35 -0700851 set_freezable();
Andrew Morton4899b8b2006-10-06 00:43:48 -0700852 while (!kthread_should_stop()) {
Paul Moore5b523302017-03-21 11:26:35 -0400853 /* NOTE: see the lock comments in auditd_send_unicast_skb() */
854 rcu_read_lock();
Paul Moore48d0e022017-05-02 10:16:05 -0400855 ac = rcu_dereference(auditd_conn);
856 if (!ac) {
Paul Moore5b523302017-03-21 11:26:35 -0400857 rcu_read_unlock();
858 goto main_queue;
859 }
Paul Moore48d0e022017-05-02 10:16:05 -0400860 net = get_net(ac->net);
Paul Moore5b523302017-03-21 11:26:35 -0400861 sk = audit_get_sk(net);
Paul Moore48d0e022017-05-02 10:16:05 -0400862 portid = ac->portid;
Paul Moore5b523302017-03-21 11:26:35 -0400863 rcu_read_unlock();
Eric Parisf3d357b2008-04-18 10:02:28 -0400864
Paul Moorec6480202016-11-29 16:53:25 -0500865 /* attempt to flush the hold queue */
Paul Moore5b523302017-03-21 11:26:35 -0400866 rc = kauditd_send_queue(sk, portid,
867 &audit_hold_queue, UNICAST_RETRIES,
868 NULL, kauditd_rehold_skb);
Yunfeng Yec34c78d2019-10-23 21:27:34 +0800869 if (rc < 0) {
Paul Moore5b523302017-03-21 11:26:35 -0400870 sk = NULL;
Paul Moorec81be522017-06-12 09:35:24 -0400871 auditd_reset(ac);
Paul Moore5b523302017-03-21 11:26:35 -0400872 goto main_queue;
David Woodhouseb7d11252005-05-19 10:56:58 +0100873 }
Richard Guy Briggs3320c512013-01-24 13:15:11 -0500874
Paul Moorec6480202016-11-29 16:53:25 -0500875 /* attempt to flush the retry queue */
Paul Moore5b523302017-03-21 11:26:35 -0400876 rc = kauditd_send_queue(sk, portid,
877 &audit_retry_queue, UNICAST_RETRIES,
878 NULL, kauditd_hold_skb);
Yunfeng Yec34c78d2019-10-23 21:27:34 +0800879 if (rc < 0) {
Paul Moore5b523302017-03-21 11:26:35 -0400880 sk = NULL;
Paul Moorec81be522017-06-12 09:35:24 -0400881 auditd_reset(ac);
Paul Moore5b523302017-03-21 11:26:35 -0400882 goto main_queue;
Paul Moorec6480202016-11-29 16:53:25 -0500883 }
884
Paul Moore5b523302017-03-21 11:26:35 -0400885main_queue:
886 /* process the main queue - do the multicast send and attempt
887 * unicast, dump failed record sends to the retry queue; if
888 * sk == NULL due to previous failures we will just do the
Paul Moorec81be522017-06-12 09:35:24 -0400889 * multicast send and move the record to the hold queue */
Paul Moore264d5092017-04-10 11:16:59 -0400890 rc = kauditd_send_queue(sk, portid, &audit_queue, 1,
891 kauditd_send_multicast_skb,
Paul Moorec81be522017-06-12 09:35:24 -0400892 (sk ?
893 kauditd_retry_skb : kauditd_hold_skb));
894 if (ac && rc < 0)
895 auditd_reset(ac);
Paul Moore264d5092017-04-10 11:16:59 -0400896 sk = NULL;
Paul Moore4aa838722016-11-29 16:53:24 -0500897
Paul Moore5b523302017-03-21 11:26:35 -0400898 /* drop our netns reference, no auditd sends past this line */
899 if (net) {
900 put_net(net);
901 net = NULL;
Richard Guy Briggs3320c512013-01-24 13:15:11 -0500902 }
Paul Moore5b523302017-03-21 11:26:35 -0400903
904 /* we have processed all the queues so wake everyone */
905 wake_up(&audit_backlog_wait);
906
907 /* NOTE: we want to wake up if there is anything on the queue,
908 * regardless of if an auditd is connected, as we need to
909 * do the multicast send and rotate records from the
910 * main queue to the retry/hold queues */
911 wait_event_freezable(kauditd_wait,
912 (skb_queue_len(&audit_queue) ? 1 : 0));
David Woodhouseb7d11252005-05-19 10:56:58 +0100913 }
Paul Moorec6480202016-11-29 16:53:25 -0500914
Andrew Morton4899b8b2006-10-06 00:43:48 -0700915 return 0;
David Woodhouseb7d11252005-05-19 10:56:58 +0100916}
917
Paul Moore3054d062020-04-21 09:10:56 -0400918int audit_send_list_thread(void *_dest)
Al Viro9044e6b2006-05-22 01:09:24 -0400919{
920 struct audit_netlink_list *dest = _dest;
Al Viro9044e6b2006-05-22 01:09:24 -0400921 struct sk_buff *skb;
Paul Moore5b523302017-03-21 11:26:35 -0400922 struct sock *sk = audit_get_sk(dest->net);
Al Viro9044e6b2006-05-22 01:09:24 -0400923
924 /* wait for parent to finish and send an ACK */
Paul Moorece4236312018-02-20 09:52:38 -0500925 audit_ctl_lock();
926 audit_ctl_unlock();
Al Viro9044e6b2006-05-22 01:09:24 -0400927
928 while ((skb = __skb_dequeue(&dest->q)) != NULL)
Paul Moore5b523302017-03-21 11:26:35 -0400929 netlink_unicast(sk, skb, dest->portid, 0);
Al Viro9044e6b2006-05-22 01:09:24 -0400930
Paul Moore5b523302017-03-21 11:26:35 -0400931 put_net(dest->net);
Al Viro9044e6b2006-05-22 01:09:24 -0400932 kfree(dest);
933
934 return 0;
935}
936
Paul Moore45a06422017-05-02 10:16:05 -0400937struct sk_buff *audit_make_reply(int seq, int type, int done,
Stephen Hemmingerb8800aa2010-10-20 17:23:50 -0700938 int multi, const void *payload, int size)
Al Viro9044e6b2006-05-22 01:09:24 -0400939{
940 struct sk_buff *skb;
941 struct nlmsghdr *nlh;
Al Viro9044e6b2006-05-22 01:09:24 -0400942 void *data;
943 int flags = multi ? NLM_F_MULTI : 0;
944 int t = done ? NLMSG_DONE : type;
945
Eric Parisee080e62009-06-11 14:31:35 -0400946 skb = nlmsg_new(size, GFP_KERNEL);
Al Viro9044e6b2006-05-22 01:09:24 -0400947 if (!skb)
948 return NULL;
949
Paul Moore45a06422017-05-02 10:16:05 -0400950 nlh = nlmsg_put(skb, 0, seq, t, size, flags);
David S. Millerc64e66c2012-06-26 21:45:21 -0700951 if (!nlh)
952 goto out_kfree_skb;
953 data = nlmsg_data(nlh);
Al Viro9044e6b2006-05-22 01:09:24 -0400954 memcpy(data, payload, size);
955 return skb;
956
David S. Millerc64e66c2012-06-26 21:45:21 -0700957out_kfree_skb:
958 kfree_skb(skb);
Al Viro9044e6b2006-05-22 01:09:24 -0400959 return NULL;
960}
961
Paul Moorea48b2842020-04-20 10:09:29 -0400962static void audit_free_reply(struct audit_reply *reply)
963{
964 if (!reply)
965 return;
966
Xu Wangc0720352020-08-26 04:00:22 +0000967 kfree_skb(reply->skb);
Paul Moorea48b2842020-04-20 10:09:29 -0400968 if (reply->net)
969 put_net(reply->net);
970 kfree(reply);
971}
972
Eric Parisf09ac9d2008-04-18 10:11:04 -0400973static int audit_send_reply_thread(void *arg)
974{
975 struct audit_reply *reply = (struct audit_reply *)arg;
976
Paul Moorece4236312018-02-20 09:52:38 -0500977 audit_ctl_lock();
978 audit_ctl_unlock();
Eric Parisf09ac9d2008-04-18 10:11:04 -0400979
980 /* Ignore failure. It'll only happen if the sender goes away,
981 because our timeout is set to infinite. */
Paul Moorea48b2842020-04-20 10:09:29 -0400982 netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0);
983 reply->skb = NULL;
984 audit_free_reply(reply);
Eric Parisf09ac9d2008-04-18 10:11:04 -0400985 return 0;
986}
Paul Moorec6480202016-11-29 16:53:25 -0500987
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700988/**
989 * audit_send_reply - send an audit reply message via netlink
Eric W. Biedermand211f1772014-03-08 15:31:54 -0800990 * @request_skb: skb of request we are replying to (used to target the reply)
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700991 * @seq: sequence number
992 * @type: audit message type
993 * @done: done (last) flag
994 * @multi: multi-part message flag
995 * @payload: payload data
996 * @size: payload size
997 *
Paul Moorea48b2842020-04-20 10:09:29 -0400998 * Allocates a skb, builds the netlink message, and sends it to the port id.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -0700999 */
Eric W. Biederman6f285b12014-02-28 19:44:55 -08001000static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
Richard Guy Briggsf9441632013-08-14 11:32:45 -04001001 int multi, const void *payload, int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002{
Eric Parisf09ac9d2008-04-18 10:11:04 -04001003 struct task_struct *tsk;
Paul Moorea48b2842020-04-20 10:09:29 -04001004 struct audit_reply *reply;
Eric Parisf09ac9d2008-04-18 10:11:04 -04001005
Paul Moorea48b2842020-04-20 10:09:29 -04001006 reply = kzalloc(sizeof(*reply), GFP_KERNEL);
Eric Parisf09ac9d2008-04-18 10:11:04 -04001007 if (!reply)
1008 return;
1009
Paul Moorea48b2842020-04-20 10:09:29 -04001010 reply->skb = audit_make_reply(seq, type, done, multi, payload, size);
1011 if (!reply->skb)
1012 goto err;
1013 reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
Paul Moore45a06422017-05-02 10:16:05 -04001014 reply->portid = NETLINK_CB(request_skb).portid;
Eric Parisf09ac9d2008-04-18 10:11:04 -04001015
1016 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
Paul Moorea48b2842020-04-20 10:09:29 -04001017 if (IS_ERR(tsk))
1018 goto err;
1019
1020 return;
1021
1022err:
1023 audit_free_reply(reply);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024}
1025
1026/*
1027 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
1028 * control messages.
1029 */
Darrel Goeddelc7bdb542006-06-27 13:26:11 -07001030static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031{
1032 int err = 0;
1033
Richard Guy Briggs5a3cb3b2013-08-16 00:04:46 -04001034 /* Only support initial user namespace for now. */
Eric Parisaa4af832014-03-30 19:07:54 -04001035 /*
1036 * We return ECONNREFUSED because it tricks userspace into thinking
1037 * that audit was not configured into the kernel. Lots of users
1038 * configure their PAM stack (because that's what the distro does)
1039 * to reject login if unable to send messages to audit. If we return
1040 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
1041 * configured in and will let login proceed. If we return EPERM
1042 * userspace will reject all logins. This should be removed when we
1043 * support non init namespaces!!
1044 */
Linus Torvalds0b747172014-04-12 12:38:53 -07001045 if (current_user_ns() != &init_user_ns)
Eric Parisaa4af832014-03-30 19:07:54 -04001046 return -ECONNREFUSED;
Eric W. Biederman34e36d8e2012-09-10 23:20:20 -07001047
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048 switch (msg_type) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 case AUDIT_LIST:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 case AUDIT_ADD:
1051 case AUDIT_DEL:
Eric Paris18900902013-04-18 19:16:36 -04001052 return -EOPNOTSUPP;
1053 case AUDIT_GET:
1054 case AUDIT_SET:
Eric Parisb0fed402013-05-22 12:54:49 -04001055 case AUDIT_GET_FEATURE:
1056 case AUDIT_SET_FEATURE:
Eric Paris18900902013-04-18 19:16:36 -04001057 case AUDIT_LIST_RULES:
1058 case AUDIT_ADD_RULE:
Amy Griffis93315ed2006-02-07 12:05:27 -05001059 case AUDIT_DEL_RULE:
Steve Grubbc2f0c7c2005-05-06 12:38:39 +01001060 case AUDIT_SIGNAL_INFO:
Miloslav Trmac522ed772007-07-15 23:40:56 -07001061 case AUDIT_TTY_GET:
1062 case AUDIT_TTY_SET:
Al Viro74c3cbe2007-07-22 08:04:18 -04001063 case AUDIT_TRIM:
1064 case AUDIT_MAKE_EQUIV:
Richard Guy Briggs5a3cb3b2013-08-16 00:04:46 -04001065 /* Only support auditd and auditctl in initial pid namespace
1066 * for now. */
Ameen Ali5985de62015-02-23 15:38:00 -05001067 if (task_active_pid_ns(current) != &init_pid_ns)
Richard Guy Briggs5a3cb3b2013-08-16 00:04:46 -04001068 return -EPERM;
1069
Eric W. Biederman90f62cf32014-04-23 14:29:27 -07001070 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 err = -EPERM;
1072 break;
Steve Grubb05474102005-05-21 00:18:37 +01001073 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -07001074 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1075 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
Eric W. Biederman90f62cf32014-04-23 14:29:27 -07001076 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077 err = -EPERM;
1078 break;
1079 default: /* bad msg */
1080 err = -EINVAL;
1081 }
1082
1083 return err;
1084}
1085
Richard Guy Briggs626abcd2019-01-18 17:42:48 -05001086static void audit_log_common_recv_msg(struct audit_context *context,
1087 struct audit_buffer **ab, u16 msg_type)
Eric Paris50397bd2008-01-07 18:14:19 -05001088{
Eric Parisdc9eb692013-04-19 13:23:09 -04001089 uid_t uid = from_kuid(&init_user_ns, current_uid());
Richard Guy Briggsf1dc4862013-12-11 13:52:26 -05001090 pid_t pid = task_tgid_nr(current);
Eric Paris50397bd2008-01-07 18:14:19 -05001091
Tyler Hicks0868a5e2013-07-25 18:02:55 -07001092 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
Eric Paris50397bd2008-01-07 18:14:19 -05001093 *ab = NULL;
Paul Moore233a6862015-11-04 08:23:52 -05001094 return;
Eric Paris50397bd2008-01-07 18:14:19 -05001095 }
1096
Richard Guy Briggs626abcd2019-01-18 17:42:48 -05001097 *ab = audit_log_start(context, GFP_KERNEL, msg_type);
Kees Cook0644ec02013-01-11 14:32:07 -08001098 if (unlikely(!*ab))
Paul Moore233a6862015-11-04 08:23:52 -05001099 return;
Richard Guy Briggsa2c97da2018-11-16 16:30:10 -05001100 audit_log_format(*ab, "pid=%d uid=%u ", pid, uid);
Eric Paris4d3fb702013-04-30 09:53:34 -04001101 audit_log_session_info(*ab);
Eric Parisb122c372013-04-19 15:00:33 -04001102 audit_log_task_context(*ab);
Eric Paris50397bd2008-01-07 18:14:19 -05001103}
1104
Richard Guy Briggs626abcd2019-01-18 17:42:48 -05001105static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
1106 u16 msg_type)
1107{
1108 audit_log_common_recv_msg(NULL, ab, msg_type);
1109}
1110
Xiu Jianfeng54609322022-06-11 17:23:04 +08001111static int is_audit_feature_set(int i)
Eric Parisb0fed402013-05-22 12:54:49 -04001112{
1113 return af.features & AUDIT_FEATURE_TO_MASK(i);
1114}
1115
1116
1117static int audit_get_feature(struct sk_buff *skb)
1118{
1119 u32 seq;
1120
1121 seq = nlmsg_hdr(skb)->nlmsg_seq;
1122
Richard Guy Briggs9ef915142014-08-24 20:37:52 -04001123 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
Eric Parisb0fed402013-05-22 12:54:49 -04001124
1125 return 0;
1126}
1127
1128static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
1129 u32 old_lock, u32 new_lock, int res)
1130{
1131 struct audit_buffer *ab;
1132
Gao fengb6c50fe2013-11-01 19:34:43 +08001133 if (audit_enabled == AUDIT_OFF)
1134 return;
Paul Moore2a1fe212018-11-26 18:40:07 -05001135
Richard Guy Briggscdfb6b32018-05-12 21:58:20 -04001136 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_FEATURE_CHANGE);
Richard Guy Briggs23138ea2018-02-21 04:30:07 -05001137 if (!ab)
1138 return;
Paul Moore2a1fe212018-11-26 18:40:07 -05001139 audit_log_task_info(ab);
Richard Guy Briggs897f1ac2014-10-30 11:22:53 -04001140 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 -04001141 audit_feature_names[which], !!old_feature, !!new_feature,
1142 !!old_lock, !!new_lock, res);
1143 audit_log_end(ab);
1144}
1145
Paul Moore75612522020-02-24 16:38:57 -05001146static int audit_set_feature(struct audit_features *uaf)
Eric Parisb0fed402013-05-22 12:54:49 -04001147{
Eric Parisb0fed402013-05-22 12:54:49 -04001148 int i;
1149
Fabian Frederick6eed9b22014-06-03 22:05:10 +02001150 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
Eric Parisb0fed402013-05-22 12:54:49 -04001151
1152 /* if there is ever a version 2 we should handle that here */
1153
1154 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1155 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1156 u32 old_feature, new_feature, old_lock, new_lock;
1157
1158 /* if we are not changing this feature, move along */
1159 if (!(feature & uaf->mask))
1160 continue;
1161
1162 old_feature = af.features & feature;
1163 new_feature = uaf->features & feature;
1164 new_lock = (uaf->lock | af.lock) & feature;
1165 old_lock = af.lock & feature;
1166
1167 /* are we changing a locked feature? */
Gao feng4547b3b2013-11-01 19:34:44 +08001168 if (old_lock && (new_feature != old_feature)) {
Eric Parisb0fed402013-05-22 12:54:49 -04001169 audit_log_feature_change(i, old_feature, new_feature,
1170 old_lock, new_lock, 0);
1171 return -EPERM;
1172 }
1173 }
1174 /* nothing invalid, do the changes */
1175 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1176 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1177 u32 old_feature, new_feature, old_lock, new_lock;
1178
1179 /* if we are not changing this feature, move along */
1180 if (!(feature & uaf->mask))
1181 continue;
1182
1183 old_feature = af.features & feature;
1184 new_feature = uaf->features & feature;
1185 old_lock = af.lock & feature;
1186 new_lock = (uaf->lock | af.lock) & feature;
1187
1188 if (new_feature != old_feature)
1189 audit_log_feature_change(i, old_feature, new_feature,
1190 old_lock, new_lock, 1);
1191
1192 if (new_feature)
1193 af.features |= feature;
1194 else
1195 af.features &= ~feature;
1196 af.lock |= new_lock;
1197 }
1198
1199 return 0;
1200}
1201
Paul Mooreb6c7c112017-05-02 10:16:05 -04001202static int audit_replace(struct pid *pid)
Richard Guy Briggs133e1e52016-01-25 18:04:15 -05001203{
Paul Mooreb6c7c112017-05-02 10:16:05 -04001204 pid_t pvnr;
Paul Moore5b523302017-03-21 11:26:35 -04001205 struct sk_buff *skb;
Richard Guy Briggs133e1e52016-01-25 18:04:15 -05001206
Paul Mooreb6c7c112017-05-02 10:16:05 -04001207 pvnr = pid_vnr(pid);
1208 skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr));
Richard Guy Briggs133e1e52016-01-25 18:04:15 -05001209 if (!skb)
1210 return -ENOMEM;
Paul Moore5b523302017-03-21 11:26:35 -04001211 return auditd_send_unicast_skb(skb);
Richard Guy Briggs133e1e52016-01-25 18:04:15 -05001212}
1213
Chris Riches022732e2023-10-18 09:23:51 +00001214static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
1215 bool *ack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216{
Eric Parisdc9eb692013-04-19 13:23:09 -04001217 u32 seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 void *data;
Paul Moore75612522020-02-24 16:38:57 -05001219 int data_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220 int err;
Steve Grubbc0404992005-05-13 18:17:42 +01001221 struct audit_buffer *ab;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222 u16 msg_type = nlh->nlmsg_type;
Al Viroe1396062006-05-25 10:19:47 -04001223 struct audit_sig_info *sig_data;
Eric Paris50397bd2008-01-07 18:14:19 -05001224 char *ctx = NULL;
Al Viroe1396062006-05-25 10:19:47 -04001225 u32 len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226
Darrel Goeddelc7bdb542006-06-27 13:26:11 -07001227 err = audit_netlink_ok(skb, msg_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 if (err)
1229 return err;
1230
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 seq = nlh->nlmsg_seq;
David S. Millerc64e66c2012-06-26 21:45:21 -07001232 data = nlmsg_data(nlh);
Paul Moore75612522020-02-24 16:38:57 -05001233 data_len = nlmsg_len(nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234
1235 switch (msg_type) {
Richard Guy Briggs09f883a2013-09-18 09:32:24 -04001236 case AUDIT_GET: {
1237 struct audit_status s;
1238 memset(&s, 0, sizeof(s));
Max Englanderb43870c2020-07-04 15:15:28 +00001239 s.enabled = audit_enabled;
1240 s.failure = audit_failure;
Paul Mooreb6c7c112017-05-02 10:16:05 -04001241 /* NOTE: use pid_vnr() so the PID is relative to the current
1242 * namespace */
Max Englanderb43870c2020-07-04 15:15:28 +00001243 s.pid = auditd_pid_vnr();
1244 s.rate_limit = audit_rate_limit;
1245 s.backlog_limit = audit_backlog_limit;
1246 s.lost = atomic_read(&audit_lost);
1247 s.backlog = skb_queue_len(&audit_queue);
1248 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
1249 s.backlog_wait_time = audit_backlog_wait_time;
1250 s.backlog_wait_time_actual = atomic_read(&audit_backlog_wait_time_actual);
Eric W. Biederman6f285b12014-02-28 19:44:55 -08001251 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 break;
Richard Guy Briggs09f883a2013-09-18 09:32:24 -04001253 }
1254 case AUDIT_SET: {
1255 struct audit_status s;
1256 memset(&s, 0, sizeof(s));
1257 /* guard against past and future API changes */
Paul Moore75612522020-02-24 16:38:57 -05001258 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
Richard Guy Briggs09f883a2013-09-18 09:32:24 -04001259 if (s.mask & AUDIT_STATUS_ENABLED) {
1260 err = audit_set_enabled(s.enabled);
zhangxiliang20c6aaa2008-07-31 10:11:19 +08001261 if (err < 0)
1262 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 }
Richard Guy Briggs09f883a2013-09-18 09:32:24 -04001264 if (s.mask & AUDIT_STATUS_FAILURE) {
1265 err = audit_set_failure(s.failure);
zhangxiliang20c6aaa2008-07-31 10:11:19 +08001266 if (err < 0)
1267 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268 }
Richard Guy Briggs09f883a2013-09-18 09:32:24 -04001269 if (s.mask & AUDIT_STATUS_PID) {
Paul Mooreb6c7c112017-05-02 10:16:05 -04001270 /* NOTE: we are using the vnr PID functions below
1271 * because the s.pid value is relative to the
1272 * namespace of the caller; at present this
1273 * doesn't matter much since you can really only
1274 * run auditd from the initial pid namespace, but
1275 * something to keep in mind if this changes */
1276 pid_t new_pid = s.pid;
Paul Moore5b523302017-03-21 11:26:35 -04001277 pid_t auditd_pid;
Paul Mooreb6c7c112017-05-02 10:16:05 -04001278 struct pid *req_pid = task_tgid(current);
1279
Steve Grubb33e8a902017-10-17 18:29:22 -04001280 /* Sanity check - PID values must match. Setting
1281 * pid to 0 is how auditd ends auditing. */
1282 if (new_pid && (new_pid != pid_vnr(req_pid)))
Paul Mooreb6c7c112017-05-02 10:16:05 -04001283 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -05001284
Paul Moore5b523302017-03-21 11:26:35 -04001285 /* test the auditd connection */
Paul Mooreb6c7c112017-05-02 10:16:05 -04001286 audit_replace(req_pid);
Paul Moore5b523302017-03-21 11:26:35 -04001287
Paul Moore48d0e022017-05-02 10:16:05 -04001288 auditd_pid = auditd_pid_vnr();
Steve Grubb33e8a902017-10-17 18:29:22 -04001289 if (auditd_pid) {
1290 /* replacing a healthy auditd is not allowed */
1291 if (new_pid) {
1292 audit_log_config_change("audit_pid",
1293 new_pid, auditd_pid, 0);
1294 return -EEXIST;
1295 }
1296 /* only current auditd can unregister itself */
1297 if (pid_vnr(req_pid) != auditd_pid) {
1298 audit_log_config_change("audit_pid",
1299 new_pid, auditd_pid, 0);
1300 return -EACCES;
1301 }
Richard Guy Briggs935c9e72016-01-25 18:04:15 -05001302 }
Paul Moore5b523302017-03-21 11:26:35 -04001303
Richard Guy Briggs533c7b62016-12-13 10:03:01 -05001304 if (new_pid) {
Paul Moore5b523302017-03-21 11:26:35 -04001305 /* register a new auditd connection */
Paul Moore48d0e022017-05-02 10:16:05 -04001306 err = auditd_set(req_pid,
1307 NETLINK_CB(skb).portid,
Chris Riches022732e2023-10-18 09:23:51 +00001308 sock_net(NETLINK_CB(skb).sk),
1309 skb, ack);
Paul Moore48d0e022017-05-02 10:16:05 -04001310 if (audit_enabled != AUDIT_OFF)
1311 audit_log_config_change("audit_pid",
1312 new_pid,
1313 auditd_pid,
1314 err ? 0 : 1);
1315 if (err)
1316 return err;
1317
Paul Moore5b523302017-03-21 11:26:35 -04001318 /* try to process any backlog */
1319 wake_up_interruptible(&kauditd_wait);
Paul Moore48d0e022017-05-02 10:16:05 -04001320 } else {
1321 if (audit_enabled != AUDIT_OFF)
1322 audit_log_config_change("audit_pid",
1323 new_pid,
1324 auditd_pid, 1);
1325
Paul Moore5b523302017-03-21 11:26:35 -04001326 /* unregister the auditd connection */
Paul Moorec81be522017-06-12 09:35:24 -04001327 auditd_reset(NULL);
Paul Moore48d0e022017-05-02 10:16:05 -04001328 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 }
Richard Guy Briggs09f883a2013-09-18 09:32:24 -04001330 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
1331 err = audit_set_rate_limit(s.rate_limit);
zhangxiliang20c6aaa2008-07-31 10:11:19 +08001332 if (err < 0)
1333 return err;
1334 }
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -04001335 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
Richard Guy Briggs09f883a2013-09-18 09:32:24 -04001336 err = audit_set_backlog_limit(s.backlog_limit);
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -04001337 if (err < 0)
1338 return err;
1339 }
Eric Paris3f0c5fa2014-01-13 16:49:28 -05001340 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
1341 if (sizeof(s) > (size_t)nlh->nlmsg_len)
1342 return -EINVAL;
Pranith Kumar724e7bf2015-03-11 14:08:19 -04001343 if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
Eric Paris3f0c5fa2014-01-13 16:49:28 -05001344 return -EINVAL;
1345 err = audit_set_backlog_wait_time(s.backlog_wait_time);
1346 if (err < 0)
1347 return err;
Richard Guy Briggs51cc83f2013-09-18 11:55:12 -04001348 }
Richard Guy Briggs92c82e82017-01-13 03:26:29 -05001349 if (s.mask == AUDIT_STATUS_LOST) {
1350 u32 lost = atomic_xchg(&audit_lost, 0);
1351
1352 audit_log_config_change("lost", 0, lost, 1);
1353 return lost;
1354 }
Max Englanderb43870c2020-07-04 15:15:28 +00001355 if (s.mask == AUDIT_STATUS_BACKLOG_WAIT_TIME_ACTUAL) {
1356 u32 actual = atomic_xchg(&audit_backlog_wait_time_actual, 0);
1357
1358 audit_log_config_change("backlog_wait_time_actual", 0, actual, 1);
1359 return actual;
1360 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 break;
Richard Guy Briggs09f883a2013-09-18 09:32:24 -04001362 }
Eric Parisb0fed402013-05-22 12:54:49 -04001363 case AUDIT_GET_FEATURE:
1364 err = audit_get_feature(skb);
1365 if (err)
1366 return err;
1367 break;
1368 case AUDIT_SET_FEATURE:
Paul Moore75612522020-02-24 16:38:57 -05001369 if (data_len < sizeof(struct audit_features))
1370 return -EINVAL;
1371 err = audit_set_feature(data);
Eric Parisb0fed402013-05-22 12:54:49 -04001372 if (err)
1373 return err;
1374 break;
Steve Grubb05474102005-05-21 00:18:37 +01001375 case AUDIT_USER:
Robert P. J. Day039b6b32007-05-08 00:29:20 -07001376 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1377 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
David Woodhouse4a4cd632005-06-22 14:56:47 +01001378 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
1379 return 0;
Paul Moore763dafc2020-04-20 16:24:34 -04001380 /* exit early if there isn't at least one character to print */
1381 if (data_len < 2)
1382 return -EINVAL;
David Woodhouse0f45aa12005-06-19 19:35:50 +01001383
Richard Guy Briggs86b2efb2016-06-24 16:35:46 -04001384 err = audit_filter(msg_type, AUDIT_FILTER_USER);
Richard Guy Briggs724e4fcc2013-11-25 21:57:51 -05001385 if (err == 1) { /* match or error */
Paul Moore75612522020-02-24 16:38:57 -05001386 char *str = data;
1387
David Woodhouse4a4cd632005-06-22 14:56:47 +01001388 err = 0;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001389 if (msg_type == AUDIT_USER_TTY) {
Peter Hurley37282a72016-01-09 22:55:31 -08001390 err = tty_audit_push();
Miloslav Trmac522ed772007-07-15 23:40:56 -07001391 if (err)
1392 break;
1393 }
Richard Guy Briggs626abcd2019-01-18 17:42:48 -05001394 audit_log_user_recv_msg(&ab, msg_type);
Paul Moore75612522020-02-24 16:38:57 -05001395 if (msg_type != AUDIT_USER_TTY) {
1396 /* ensure NULL termination */
1397 str[data_len - 1] = '\0';
Richard Guy Briggsb50eba72013-09-16 18:20:42 -04001398 audit_log_format(ab, " msg='%.*s'",
1399 AUDIT_MESSAGE_TEXT_MAX,
Paul Moore75612522020-02-24 16:38:57 -05001400 str);
1401 } else {
Eric Parisf7616102013-04-11 11:25:00 -04001402 audit_log_format(ab, " data=");
Shreenidhi Shedi5ee6cfd2022-05-15 13:01:09 +05301403 if (str[data_len - 1] == '\0')
Paul Moore75612522020-02-24 16:38:57 -05001404 data_len--;
1405 audit_log_n_untrustedstring(ab, str, data_len);
David Woodhouse4a4cd632005-06-22 14:56:47 +01001406 }
Eric Paris50397bd2008-01-07 18:14:19 -05001407 audit_log_end(ab);
David Woodhouse0f45aa12005-06-19 19:35:50 +01001408 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 break;
Amy Griffis93315ed2006-02-07 12:05:27 -05001410 case AUDIT_ADD_RULE:
1411 case AUDIT_DEL_RULE:
Paul Moore75612522020-02-24 16:38:57 -05001412 if (data_len < sizeof(struct audit_rule_data))
Amy Griffis93315ed2006-02-07 12:05:27 -05001413 return -EINVAL;
Eric Paris1a6b9f22008-01-07 17:09:31 -05001414 if (audit_enabled == AUDIT_LOCKED) {
Richard Guy Briggs626abcd2019-01-18 17:42:48 -05001415 audit_log_common_recv_msg(audit_context(), &ab,
1416 AUDIT_CONFIG_CHANGE);
Richard Guy Briggs53fc7a02018-12-10 17:17:48 -05001417 audit_log_format(ab, " op=%s audit_enabled=%d res=0",
1418 msg_type == AUDIT_ADD_RULE ?
1419 "add_rule" : "remove_rule",
1420 audit_enabled);
Eric Paris50397bd2008-01-07 18:14:19 -05001421 audit_log_end(ab);
Steve Grubb6a01b07f2007-01-19 14:39:55 -05001422 return -EPERM;
1423 }
Paul Moore75612522020-02-24 16:38:57 -05001424 err = audit_rule_change(msg_type, seq, data, data_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425 break;
Richard Guy Briggsce0d9f02013-11-20 14:01:53 -05001426 case AUDIT_LIST_RULES:
Eric W. Biederman6f285b12014-02-28 19:44:55 -08001427 err = audit_list_rules_send(skb, seq);
Richard Guy Briggsce0d9f02013-11-20 14:01:53 -05001428 break;
Al Viro74c3cbe2007-07-22 08:04:18 -04001429 case AUDIT_TRIM:
1430 audit_trim_trees();
Richard Guy Briggs626abcd2019-01-18 17:42:48 -05001431 audit_log_common_recv_msg(audit_context(), &ab,
1432 AUDIT_CONFIG_CHANGE);
Al Viro74c3cbe2007-07-22 08:04:18 -04001433 audit_log_format(ab, " op=trim res=1");
1434 audit_log_end(ab);
1435 break;
1436 case AUDIT_MAKE_EQUIV: {
1437 void *bufp = data;
1438 u32 sizes[2];
Paul Moore75612522020-02-24 16:38:57 -05001439 size_t msglen = data_len;
Al Viro74c3cbe2007-07-22 08:04:18 -04001440 char *old, *new;
1441
1442 err = -EINVAL;
Harvey Harrison7719e432008-04-27 02:39:56 -07001443 if (msglen < 2 * sizeof(u32))
Al Viro74c3cbe2007-07-22 08:04:18 -04001444 break;
1445 memcpy(sizes, bufp, 2 * sizeof(u32));
1446 bufp += 2 * sizeof(u32);
Harvey Harrison7719e432008-04-27 02:39:56 -07001447 msglen -= 2 * sizeof(u32);
1448 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
Al Viro74c3cbe2007-07-22 08:04:18 -04001449 if (IS_ERR(old)) {
1450 err = PTR_ERR(old);
1451 break;
1452 }
Harvey Harrison7719e432008-04-27 02:39:56 -07001453 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
Al Viro74c3cbe2007-07-22 08:04:18 -04001454 if (IS_ERR(new)) {
1455 err = PTR_ERR(new);
1456 kfree(old);
1457 break;
1458 }
1459 /* OK, here comes... */
1460 err = audit_tag_tree(old, new);
1461
Richard Guy Briggs626abcd2019-01-18 17:42:48 -05001462 audit_log_common_recv_msg(audit_context(), &ab,
1463 AUDIT_CONFIG_CHANGE);
Al Viro74c3cbe2007-07-22 08:04:18 -04001464 audit_log_format(ab, " op=make_equiv old=");
1465 audit_log_untrustedstring(ab, old);
1466 audit_log_format(ab, " new=");
1467 audit_log_untrustedstring(ab, new);
1468 audit_log_format(ab, " res=%d", !err);
1469 audit_log_end(ab);
1470 kfree(old);
1471 kfree(new);
1472 break;
1473 }
Steve Grubbc2f0c7c2005-05-06 12:38:39 +01001474 case AUDIT_SIGNAL_INFO:
Eric Paris939cbf22009-09-23 13:46:00 -04001475 len = 0;
1476 if (audit_sig_sid) {
1477 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1478 if (err)
1479 return err;
1480 }
Xiu Jianfengbc6e60a2021-12-14 19:48:54 +08001481 sig_data = kmalloc(struct_size(sig_data, ctx, len), GFP_KERNEL);
Al Viroe1396062006-05-25 10:19:47 -04001482 if (!sig_data) {
Eric Paris939cbf22009-09-23 13:46:00 -04001483 if (audit_sig_sid)
1484 security_release_secctx(ctx, len);
Al Viroe1396062006-05-25 10:19:47 -04001485 return -ENOMEM;
1486 }
Eric W. Biedermancca080d2012-02-07 16:53:48 -08001487 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
Al Viroe1396062006-05-25 10:19:47 -04001488 sig_data->pid = audit_sig_pid;
Eric Paris939cbf22009-09-23 13:46:00 -04001489 if (audit_sig_sid) {
1490 memcpy(sig_data->ctx, ctx, len);
1491 security_release_secctx(ctx, len);
1492 }
Eric W. Biederman6f285b12014-02-28 19:44:55 -08001493 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
Xiu Jianfeng30561b52021-12-17 09:01:51 +08001494 sig_data, struct_size(sig_data, ctx, len));
Al Viroe1396062006-05-25 10:19:47 -04001495 kfree(sig_data);
Steve Grubbc2f0c7c2005-05-06 12:38:39 +01001496 break;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001497 case AUDIT_TTY_GET: {
1498 struct audit_tty_status s;
Peter Hurley2e28d382016-01-09 22:55:33 -08001499 unsigned int t;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001500
Peter Hurley2e28d382016-01-09 22:55:33 -08001501 t = READ_ONCE(current->signal->audit_tty);
1502 s.enabled = t & AUDIT_TTY_ENABLE;
1503 s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
Thomas Gleixner20703202009-12-09 14:19:35 +00001504
Eric W. Biederman6f285b12014-02-28 19:44:55 -08001505 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
Miloslav Trmac522ed772007-07-15 23:40:56 -07001506 break;
1507 }
1508 case AUDIT_TTY_SET: {
Richard Guy Briggsa06e56b2013-11-15 11:29:02 -05001509 struct audit_tty_status s, old;
Richard Guy Briggsa06e56b2013-11-15 11:29:02 -05001510 struct audit_buffer *ab;
Peter Hurley2e28d382016-01-09 22:55:33 -08001511 unsigned int t;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001512
Richard Guy Briggs46e959e2013-05-03 14:03:50 -04001513 memset(&s, 0, sizeof(s));
1514 /* guard against past and future API changes */
Paul Moore75612522020-02-24 16:38:57 -05001515 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
Eric Paris0e23bac2014-01-13 21:12:34 -05001516 /* check if new data is valid */
1517 if ((s.enabled != 0 && s.enabled != 1) ||
1518 (s.log_passwd != 0 && s.log_passwd != 1))
1519 err = -EINVAL;
1520
Peter Hurley2e28d382016-01-09 22:55:33 -08001521 if (err)
1522 t = READ_ONCE(current->signal->audit_tty);
1523 else {
1524 t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
1525 t = xchg(&current->signal->audit_tty, t);
Eric Paris0e23bac2014-01-13 21:12:34 -05001526 }
Peter Hurley2e28d382016-01-09 22:55:33 -08001527 old.enabled = t & AUDIT_TTY_ENABLE;
1528 old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
Eric Paris0e23bac2014-01-13 21:12:34 -05001529
Richard Guy Briggs626abcd2019-01-18 17:42:48 -05001530 audit_log_common_recv_msg(audit_context(), &ab,
1531 AUDIT_CONFIG_CHANGE);
Eric Paris1ce319f2014-01-13 21:16:59 -05001532 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1533 " old-log_passwd=%d new-log_passwd=%d res=%d",
1534 old.enabled, s.enabled, old.log_passwd,
1535 s.log_passwd, !err);
Richard Guy Briggsa06e56b2013-11-15 11:29:02 -05001536 audit_log_end(ab);
Miloslav Trmac522ed772007-07-15 23:40:56 -07001537 break;
1538 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001539 default:
1540 err = -EINVAL;
1541 break;
1542 }
1543
1544 return err < 0 ? err : 0;
1545}
1546
Paul Moorea9d16202017-05-02 10:16:05 -04001547/**
1548 * audit_receive - receive messages from a netlink control socket
1549 * @skb: the message buffer
1550 *
1551 * Parse the provided skb and deal with any messages that may be present,
1552 * malformed skbs are discarded.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001553 */
Chris Riches022732e2023-10-18 09:23:51 +00001554static void audit_receive(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555{
Eric Parisea7ae602009-06-11 14:31:35 -04001556 struct nlmsghdr *nlh;
Chris Riches022732e2023-10-18 09:23:51 +00001557 bool ack;
Eric Parisea7ae602009-06-11 14:31:35 -04001558 /*
Hong zhi guo94191212013-03-27 06:49:06 +00001559 * len MUST be signed for nlmsg_next to be able to dec it below 0
Eric Parisea7ae602009-06-11 14:31:35 -04001560 * if the nlmsg_len was not aligned
1561 */
1562 int len;
1563 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564
Eric Parisea7ae602009-06-11 14:31:35 -04001565 nlh = nlmsg_hdr(skb);
1566 len = skb->len;
1567
Paul Moorece4236312018-02-20 09:52:38 -05001568 audit_ctl_lock();
Hong zhi guo94191212013-03-27 06:49:06 +00001569 while (nlmsg_ok(nlh, len)) {
Chris Riches022732e2023-10-18 09:23:51 +00001570 ack = nlh->nlmsg_flags & NLM_F_ACK;
1571 err = audit_receive_msg(skb, nlh, &ack);
1572
1573 /* send an ack if the user asked for one and audit_receive_msg
1574 * didn't already do it, or if there was an error. */
1575 if (ack || err)
Johannes Berg2d4bc932017-04-12 14:34:04 +02001576 netlink_ack(skb, nlh, err, NULL);
Eric Parisea7ae602009-06-11 14:31:35 -04001577
Alexandru Copot2851da52013-03-28 23:31:29 +02001578 nlh = nlmsg_next(nlh, &len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001579 }
Paul Moorece4236312018-02-20 09:52:38 -05001580 audit_ctl_unlock();
Paul Moore8f110f52021-12-13 15:45:20 -05001581
1582 /* can't block with the ctrl lock, so penalize the sender now */
1583 if (audit_backlog_limit &&
1584 (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
1585 DECLARE_WAITQUEUE(wait, current);
1586
1587 /* wake kauditd to try and flush the queue */
1588 wake_up_interruptible(&kauditd_wait);
1589
1590 add_wait_queue_exclusive(&audit_backlog_wait, &wait);
1591 set_current_state(TASK_UNINTERRUPTIBLE);
1592 schedule_timeout(audit_backlog_wait_time);
1593 remove_wait_queue(&audit_backlog_wait, &wait);
1594 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595}
1596
Richard Guy Briggs9d2161b2020-04-22 17:37:04 -04001597/* Log information about who is connecting to the audit multicast socket */
1598static void audit_log_multicast(int group, const char *op, int err)
Richard Guy Briggs3a101b82014-04-22 21:31:56 -04001599{
Richard Guy Briggs9d2161b2020-04-22 17:37:04 -04001600 const struct cred *cred;
1601 struct tty_struct *tty;
1602 char comm[sizeof(current->comm)];
1603 struct audit_buffer *ab;
Richard Guy Briggs3a101b82014-04-22 21:31:56 -04001604
Richard Guy Briggs9d2161b2020-04-22 17:37:04 -04001605 if (!audit_enabled)
1606 return;
1607
1608 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
1609 if (!ab)
1610 return;
1611
1612 cred = current_cred();
1613 tty = audit_get_tty();
1614 audit_log_format(ab, "pid=%u uid=%u auid=%u tty=%s ses=%u",
Ricardo Robaina61c60972024-08-28 08:25:06 -03001615 task_tgid_nr(current),
Richard Guy Briggs9d2161b2020-04-22 17:37:04 -04001616 from_kuid(&init_user_ns, cred->uid),
1617 from_kuid(&init_user_ns, audit_get_loginuid(current)),
1618 tty ? tty_name(tty) : "(none)",
1619 audit_get_sessionid(current));
1620 audit_put_tty(tty);
1621 audit_log_task_context(ab); /* subj= */
1622 audit_log_format(ab, " comm=");
1623 audit_log_untrustedstring(ab, get_task_comm(comm, current));
1624 audit_log_d_path_exe(ab, current->mm); /* exe= */
1625 audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
1626 audit_log_end(ab);
1627}
1628
1629/* Run custom bind function on netlink socket group connect or bind requests. */
1630static int audit_multicast_bind(struct net *net, int group)
1631{
1632 int err = 0;
1633
1634 if (!capable(CAP_AUDIT_READ))
1635 err = -EPERM;
1636 audit_log_multicast(group, "connect", err);
1637 return err;
1638}
1639
1640static void audit_multicast_unbind(struct net *net, int group)
1641{
1642 audit_log_multicast(group, "disconnect", 0);
Richard Guy Briggs3a101b82014-04-22 21:31:56 -04001643}
1644
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001645static int __net_init audit_net_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001646{
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +00001647 struct netlink_kernel_cfg cfg = {
1648 .input = audit_receive,
Richard Guy Briggs9d2161b2020-04-22 17:37:04 -04001649 .bind = audit_multicast_bind,
1650 .unbind = audit_multicast_unbind,
Richard Guy Briggs451f9212014-04-22 21:31:57 -04001651 .flags = NL_CFG_F_NONROOT_RECV,
1652 .groups = AUDIT_NLGRP_MAX,
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +00001653 };
Amy Griffisf368c07d2006-04-07 16:55:56 -04001654
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001655 struct audit_net *aunet = net_generic(net, audit_net_id);
1656
Paul Moore5b523302017-03-21 11:26:35 -04001657 aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1658 if (aunet->sk == NULL) {
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001659 audit_panic("cannot initialize netlink socket in namespace");
Gao feng11ee39e2013-12-17 11:10:41 +08001660 return -ENOMEM;
1661 }
Paul Mooref4b3ee32021-12-09 11:46:07 -05001662 /* limit the timeout in case auditd is blocked/stopped */
1663 aunet->sk->sk_sndtimeo = HZ / 10;
Paul Moore5b523302017-03-21 11:26:35 -04001664
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001665 return 0;
1666}
1667
1668static void __net_exit audit_net_exit(struct net *net)
1669{
1670 struct audit_net *aunet = net_generic(net, audit_net_id);
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001671
Paul Moore48d0e022017-05-02 10:16:05 -04001672 /* NOTE: you would think that we would want to check the auditd
1673 * connection and potentially reset it here if it lives in this
1674 * namespace, but since the auditd connection tracking struct holds a
1675 * reference to this namespace (see auditd_set()) we are only ever
1676 * going to get here after that connection has been released */
Paul Moore5b523302017-03-21 11:26:35 -04001677
1678 netlink_kernel_release(aunet->sk);
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001679}
1680
Richard Guy Briggs86268772013-07-16 13:18:45 -04001681static struct pernet_operations audit_net_ops __net_initdata = {
Richard Guy Briggs33faba72013-07-16 13:18:45 -04001682 .init = audit_net_init,
1683 .exit = audit_net_exit,
1684 .id = &audit_net_id,
1685 .size = sizeof(struct audit_net),
1686};
1687
1688/* Initialize audit support at boot time. */
1689static int __init audit_init(void)
1690{
1691 int i;
1692
Eric Parisa3f07112008-11-05 12:47:09 -05001693 if (audit_initialized == AUDIT_DISABLED)
1694 return 0;
1695
Kunwu Chanaa13b702024-01-24 14:02:24 +08001696 audit_buffer_cache = KMEM_CACHE(audit_buffer, SLAB_PANIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697
Paul Mooreaf8b8242016-11-29 16:53:24 -05001698 skb_queue_head_init(&audit_queue);
Paul Moorec6480202016-11-29 16:53:25 -05001699 skb_queue_head_init(&audit_retry_queue);
Paul Mooreaf8b8242016-11-29 16:53:24 -05001700 skb_queue_head_init(&audit_hold_queue);
Darrel Goeddel3dc7e312006-03-10 18:14:06 -06001701
Amy Griffisf368c07d2006-04-07 16:55:56 -04001702 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1703 INIT_LIST_HEAD(&audit_inode_hash[i]);
Amy Griffisf368c07d2006-04-07 16:55:56 -04001704
Paul Moorece4236312018-02-20 09:52:38 -05001705 mutex_init(&audit_cmd_mutex.lock);
1706 audit_cmd_mutex.owner = NULL;
1707
Paul Moore5b523302017-03-21 11:26:35 -04001708 pr_info("initializing netlink subsys (%s)\n",
Hongbo Li8c1867a2024-08-31 17:52:51 +08001709 str_enabled_disabled(audit_default));
Paul Moore5b523302017-03-21 11:26:35 -04001710 register_pernet_subsys(&audit_net_ops);
1711
1712 audit_initialized = AUDIT_INITIALIZED;
Paul Moore5b523302017-03-21 11:26:35 -04001713
Paul Moore6c925562016-11-29 16:53:23 -05001714 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
1715 if (IS_ERR(kauditd_task)) {
1716 int err = PTR_ERR(kauditd_task);
1717 panic("audit: failed to start the kauditd thread (%d)\n", err);
1718 }
1719
Steve Grubb7c397d02016-12-14 15:59:46 -05001720 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL,
1721 "state=initialized audit_enabled=%u res=1",
1722 audit_enabled);
Paul Moore6c925562016-11-29 16:53:23 -05001723
Linus Torvalds1da177e2005-04-16 15:20:36 -07001724 return 0;
1725}
Paul Moorebe4104a2017-09-01 09:44:44 -04001726postcore_initcall(audit_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001727
Greg Edwards11dd2662018-03-05 15:05:20 -07001728/*
1729 * Process kernel command-line parameter at boot time.
1730 * audit={0|off} or audit={1|on}.
1731 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732static int __init audit_enable(char *str)
1733{
Greg Edwards11dd2662018-03-05 15:05:20 -07001734 if (!strcasecmp(str, "off") || !strcmp(str, "0"))
1735 audit_default = AUDIT_OFF;
1736 else if (!strcasecmp(str, "on") || !strcmp(str, "1"))
1737 audit_default = AUDIT_ON;
1738 else {
1739 pr_err("audit: invalid 'audit' parameter value (%s)\n", str);
1740 audit_default = AUDIT_ON;
1741 }
Paul Moore80ab4df2017-09-01 09:44:51 -04001742
1743 if (audit_default == AUDIT_OFF)
Eric Parisa3f07112008-11-05 12:47:09 -05001744 audit_initialized = AUDIT_DISABLED;
Paul Moore5d842a52017-09-01 09:45:05 -04001745 if (audit_set_enabled(audit_default))
Greg Edwards11dd2662018-03-05 15:05:20 -07001746 pr_err("audit: error setting audit state (%d)\n",
1747 audit_default);
Eric Parisa3f07112008-11-05 12:47:09 -05001748
Joe Perchesd957f7b2014-01-14 10:33:12 -08001749 pr_info("%s\n", audit_default ?
Gao fengd3ca0342013-10-31 14:31:01 +08001750 "enabled (after initialization)" : "disabled (until reboot)");
Eric Parisa3f07112008-11-05 12:47:09 -05001751
OGAWA Hirofumi9b410462006-03-31 02:30:33 -08001752 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754__setup("audit=", audit_enable);
1755
Richard Guy Briggsf910fde2013-09-17 12:34:52 -04001756/* Process kernel command-line parameter at boot time.
1757 * audit_backlog_limit=<n> */
1758static int __init audit_backlog_limit_set(char *str)
1759{
Joe Perches3e1d0bb2014-01-14 10:33:13 -08001760 u32 audit_backlog_limit_arg;
Joe Perchesd957f7b2014-01-14 10:33:12 -08001761
Richard Guy Briggsf910fde2013-09-17 12:34:52 -04001762 pr_info("audit_backlog_limit: ");
Joe Perches3e1d0bb2014-01-14 10:33:13 -08001763 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1764 pr_cont("using default of %u, unable to parse %s\n",
Joe Perchesd957f7b2014-01-14 10:33:12 -08001765 audit_backlog_limit, str);
Richard Guy Briggsf910fde2013-09-17 12:34:52 -04001766 return 1;
1767 }
Joe Perches3e1d0bb2014-01-14 10:33:13 -08001768
1769 audit_backlog_limit = audit_backlog_limit_arg;
Joe Perchesd957f7b2014-01-14 10:33:12 -08001770 pr_cont("%d\n", audit_backlog_limit);
Richard Guy Briggsf910fde2013-09-17 12:34:52 -04001771
1772 return 1;
1773}
1774__setup("audit_backlog_limit=", audit_backlog_limit_set);
1775
Chris Wright16e19042005-05-06 15:53:34 +01001776static void audit_buffer_free(struct audit_buffer *ab)
1777{
Chris Wright8fc61152005-05-06 15:54:17 +01001778 if (!ab)
1779 return;
1780
Markus Elfringd865e572016-01-13 09:18:55 -05001781 kfree_skb(ab->skb);
Paul Moore8cc96382017-05-02 10:16:05 -04001782 kmem_cache_free(audit_buffer_cache, ab);
Chris Wright16e19042005-05-06 15:53:34 +01001783}
1784
Paul Moore8cc96382017-05-02 10:16:05 -04001785static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
1786 gfp_t gfp_mask, int type)
Chris Wright16e19042005-05-06 15:53:34 +01001787{
Paul Moore8cc96382017-05-02 10:16:05 -04001788 struct audit_buffer *ab;
Chris Wright16e19042005-05-06 15:53:34 +01001789
Paul Moore8cc96382017-05-02 10:16:05 -04001790 ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask);
1791 if (!ab)
1792 return NULL;
Eric Parisee080e62009-06-11 14:31:35 -04001793
1794 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1795 if (!ab->skb)
David S. Millerc64e66c2012-06-26 21:45:21 -07001796 goto err;
Paul Moore8cc96382017-05-02 10:16:05 -04001797 if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
1798 goto err;
Eric Parisee080e62009-06-11 14:31:35 -04001799
Paul Moore8cc96382017-05-02 10:16:05 -04001800 ab->ctx = ctx;
1801 ab->gfp_mask = gfp_mask;
Eric Parisee080e62009-06-11 14:31:35 -04001802
Chris Wright16e19042005-05-06 15:53:34 +01001803 return ab;
Eric Parisee080e62009-06-11 14:31:35 -04001804
Chris Wright8fc61152005-05-06 15:54:17 +01001805err:
1806 audit_buffer_free(ab);
1807 return NULL;
Chris Wright16e19042005-05-06 15:53:34 +01001808}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001809
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001810/**
1811 * audit_serial - compute a serial number for the audit record
1812 *
1813 * Compute a serial number for the audit record. Audit records are
David Woodhousebfb44962005-05-21 21:08:09 +01001814 * written to user-space as soon as they are generated, so a complete
1815 * audit record may be written in several pieces. The timestamp of the
1816 * record and this serial number are used by the user-space tools to
1817 * determine which pieces belong to the same audit record. The
1818 * (timestamp,serial) tuple is unique for each syscall and is live from
1819 * syscall entry to syscall exit.
1820 *
David Woodhousebfb44962005-05-21 21:08:09 +01001821 * NOTE: Another possibility is to store the formatted records off the
1822 * audit context (for those records that have a context), and emit them
1823 * all at syscall exit. However, this could delay the reporting of
1824 * significant errors until syscall exit (or never, if the system
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001825 * halts).
1826 */
David Woodhousebfb44962005-05-21 21:08:09 +01001827unsigned int audit_serial(void)
1828{
Richard Guy Briggs01478d72014-06-13 18:22:00 -04001829 static atomic_t serial = ATOMIC_INIT(0);
David Woodhousebfb44962005-05-21 21:08:09 +01001830
Yejune Deng6b321182020-11-30 16:35:45 +08001831 return atomic_inc_return(&serial);
David Woodhousebfb44962005-05-21 21:08:09 +01001832}
1833
Daniel Walker5600b892007-10-18 03:06:10 -07001834static inline void audit_get_stamp(struct audit_context *ctx,
Deepa Dinamani2115bb22017-05-02 10:16:05 -04001835 struct timespec64 *t, unsigned int *serial)
David Woodhousebfb44962005-05-21 21:08:09 +01001836{
Al Viro48887e62008-12-06 01:05:50 -05001837 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
Paul Moore290e44b72018-07-17 14:45:08 -04001838 ktime_get_coarse_real_ts64(t);
David Woodhousebfb44962005-05-21 21:08:09 +01001839 *serial = audit_serial();
1840 }
1841}
1842
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001843/**
1844 * audit_log_start - obtain an audit buffer
1845 * @ctx: audit_context (may be NULL)
1846 * @gfp_mask: type of allocation
1847 * @type: audit message type
1848 *
1849 * Returns audit_buffer pointer on success or NULL on error.
1850 *
1851 * Obtain an audit buffer. This routine does locking to obtain the
1852 * audit buffer, but then no locking is required for calls to
1853 * audit_log_*format. If the task (ctx) is a task that is currently in a
1854 * syscall, then the syscall is marked as auditable and an audit record
1855 * will be written at syscall exit. If there is no associated task, then
1856 * task context (ctx) should be NULL.
1857 */
Al Viro9796fdd2005-10-21 03:22:03 -04001858struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001859 int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001860{
Paul Moore31975422016-11-29 16:53:25 -05001861 struct audit_buffer *ab;
Deepa Dinamani2115bb22017-05-02 10:16:05 -04001862 struct timespec64 t;
Kees Cook3f649ab2020-06-03 13:09:38 -07001863 unsigned int serial;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001864
Eric Parisa3f07112008-11-05 12:47:09 -05001865 if (audit_initialized != AUDIT_INITIALIZED)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001866 return NULL;
1867
Richard Guy Briggsd904ac02018-06-05 11:45:07 -04001868 if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCLUDE)))
Dustin Kirklandc8edc802005-11-03 16:12:36 +00001869 return NULL;
1870
Paul Moore5b523302017-03-21 11:26:35 -04001871 /* NOTE: don't ever fail/sleep on these two conditions:
Paul Moorea09cfa42016-11-29 16:53:26 -05001872 * 1. auditd generated record - since we need auditd to drain the
1873 * queue; also, when we are checking for auditd, compare PIDs using
1874 * task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
1875 * using a PID anchored in the caller's namespace
Paul Moore5b523302017-03-21 11:26:35 -04001876 * 2. generator holding the audit_cmd_mutex - we don't want to block
Paul Moore8f110f52021-12-13 15:45:20 -05001877 * while holding the mutex, although we do penalize the sender
1878 * later in audit_receive() when it is safe to block
1879 */
Paul Moorece4236312018-02-20 09:52:38 -05001880 if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
Paul Moore5b523302017-03-21 11:26:35 -04001881 long stime = audit_backlog_wait_time;
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001882
Paul Moore31975422016-11-29 16:53:25 -05001883 while (audit_backlog_limit &&
1884 (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
1885 /* wake kauditd to try and flush the queue */
1886 wake_up_interruptible(&kauditd_wait);
David Woodhouseac4cec42005-07-02 14:08:48 +01001887
Paul Moore31975422016-11-29 16:53:25 -05001888 /* sleep if we are allowed and we haven't exhausted our
1889 * backlog wait limit */
Paul Moore5b523302017-03-21 11:26:35 -04001890 if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
Max Englanderb43870c2020-07-04 15:15:28 +00001891 long rtime = stime;
1892
Paul Moore31975422016-11-29 16:53:25 -05001893 DECLARE_WAITQUEUE(wait, current);
1894
1895 add_wait_queue_exclusive(&audit_backlog_wait,
1896 &wait);
1897 set_current_state(TASK_UNINTERRUPTIBLE);
Max Englanderb43870c2020-07-04 15:15:28 +00001898 stime = schedule_timeout(rtime);
1899 atomic_add(rtime - stime, &audit_backlog_wait_time_actual);
Paul Moore31975422016-11-29 16:53:25 -05001900 remove_wait_queue(&audit_backlog_wait, &wait);
1901 } else {
1902 if (audit_rate_check() && printk_ratelimit())
1903 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1904 skb_queue_len(&audit_queue),
1905 audit_backlog_limit);
1906 audit_log_lost("backlog limit exceeded");
1907 return NULL;
Konstantin Khlebnikov8ac1c8d2013-09-24 15:27:42 -07001908 }
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001909 }
David Woodhousefb19b4c2005-05-19 14:55:56 +01001910 }
1911
David Woodhouse9ad9ad32005-06-22 15:04:33 +01001912 ab = audit_buffer_alloc(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913 if (!ab) {
1914 audit_log_lost("out of memory in audit_log_start");
1915 return NULL;
1916 }
1917
David Woodhousebfb44962005-05-21 21:08:09 +01001918 audit_get_stamp(ab->ctx, &t, &serial);
Richard Guy Briggs6d915472020-09-22 08:44:50 -04001919 /* cancel dummy context to enable supporting records */
1920 if (ctx)
1921 ctx->dummy = 0;
Deepa Dinamani2115bb22017-05-02 10:16:05 -04001922 audit_log_format(ab, "audit(%llu.%03lu:%u): ",
1923 (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
Paul Moore31975422016-11-29 16:53:25 -05001924
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925 return ab;
1926}
1927
Chris Wright8fc61152005-05-06 15:54:17 +01001928/**
Chris Wright5ac52f32005-05-06 15:54:53 +01001929 * audit_expand - expand skb in the audit buffer
Chris Wright8fc61152005-05-06 15:54:17 +01001930 * @ab: audit_buffer
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001931 * @extra: space to add at tail of the skb
Chris Wright8fc61152005-05-06 15:54:17 +01001932 *
1933 * Returns 0 (no space) on failed expansion, or available space if
1934 * successful.
1935 */
David Woodhousee3b926b2005-05-10 18:56:08 +01001936static inline int audit_expand(struct audit_buffer *ab, int extra)
Chris Wright8fc61152005-05-06 15:54:17 +01001937{
Chris Wright5ac52f32005-05-06 15:54:53 +01001938 struct sk_buff *skb = ab->skb;
Herbert Xu406a1d82008-01-28 20:47:09 -08001939 int oldtail = skb_tailroom(skb);
1940 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1941 int newtail = skb_tailroom(skb);
1942
Chris Wright5ac52f32005-05-06 15:54:53 +01001943 if (ret < 0) {
1944 audit_log_lost("out of memory in audit_expand");
Chris Wright8fc61152005-05-06 15:54:17 +01001945 return 0;
Chris Wright5ac52f32005-05-06 15:54:53 +01001946 }
Herbert Xu406a1d82008-01-28 20:47:09 -08001947
1948 skb->truesize += newtail - oldtail;
1949 return newtail;
Chris Wright8fc61152005-05-06 15:54:17 +01001950}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001951
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001952/*
1953 * Format an audit message into the audit buffer. If there isn't enough
Linus Torvalds1da177e2005-04-16 15:20:36 -07001954 * room in the audit buffer, more room will be allocated and vsnprint
1955 * will be called a second time. Currently, we assume that a printk
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001956 * can't format message larger than 1024 bytes, so we don't either.
1957 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001958static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1959 va_list args)
1960{
1961 int len, avail;
Chris Wright5ac52f32005-05-06 15:54:53 +01001962 struct sk_buff *skb;
David Woodhouseeecb0a72005-05-10 18:58:51 +01001963 va_list args2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964
1965 if (!ab)
1966 return;
1967
Chris Wright5ac52f32005-05-06 15:54:53 +01001968 BUG_ON(!ab->skb);
1969 skb = ab->skb;
1970 avail = skb_tailroom(skb);
1971 if (avail == 0) {
David Woodhousee3b926b2005-05-10 18:56:08 +01001972 avail = audit_expand(ab, AUDIT_BUFSIZ);
Chris Wright8fc61152005-05-06 15:54:17 +01001973 if (!avail)
1974 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001975 }
David Woodhouseeecb0a72005-05-10 18:58:51 +01001976 va_copy(args2, args);
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001977 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001978 if (len >= avail) {
1979 /* The printk buffer is 1024 bytes long, so if we get
1980 * here and AUDIT_BUFSIZ is at least 1024, then we can
1981 * log everything that printk could have logged. */
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001982 avail = audit_expand(ab,
1983 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
Chris Wright8fc61152005-05-06 15:54:17 +01001984 if (!avail)
Jesper Juhla0e86bd2012-01-08 22:44:29 +01001985 goto out_va_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07001986 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001987 }
Steve Grubb168b7172005-05-19 10:24:22 +01001988 if (len > 0)
1989 skb_put(skb, len);
Jesper Juhla0e86bd2012-01-08 22:44:29 +01001990out_va_end:
1991 va_end(args2);
Chris Wright8fc61152005-05-06 15:54:17 +01001992out:
1993 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994}
1995
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07001996/**
1997 * audit_log_format - format a message into the audit buffer.
1998 * @ab: audit_buffer
1999 * @fmt: format string
2000 * @...: optional parameters matching @fmt string
2001 *
2002 * All the work is done in audit_log_vformat.
2003 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002004void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
2005{
2006 va_list args;
2007
2008 if (!ab)
2009 return;
2010 va_start(args, fmt);
2011 audit_log_vformat(ab, fmt, args);
2012 va_end(args);
2013}
2014
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002015/**
Geliang Tang196a5082017-08-07 21:44:24 +08002016 * audit_log_n_hex - convert a buffer to hex and append it to the audit skb
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002017 * @ab: the audit_buffer
2018 * @buf: buffer to convert to hex
2019 * @len: length of @buf to be converted
2020 *
2021 * No return value; failure to expand is silently ignored.
2022 *
2023 * This function will take the passed buf and convert it into a string of
2024 * ascii hex digits. The new string is placed onto the skb.
2025 */
Eric Parisb556f8a2008-04-18 10:12:59 -04002026void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
Steve Grubb168b7172005-05-19 10:24:22 +01002027 size_t len)
83c7d092005-04-29 15:54:44 +01002028{
Steve Grubb168b7172005-05-19 10:24:22 +01002029 int i, avail, new_len;
2030 unsigned char *ptr;
2031 struct sk_buff *skb;
83c7d092005-04-29 15:54:44 +01002032
Amy Griffis8ef2d302006-09-07 17:03:02 -04002033 if (!ab)
2034 return;
2035
Steve Grubb168b7172005-05-19 10:24:22 +01002036 BUG_ON(!ab->skb);
2037 skb = ab->skb;
2038 avail = skb_tailroom(skb);
2039 new_len = len<<1;
2040 if (new_len >= avail) {
2041 /* Round the buffer request up to the next multiple */
2042 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
2043 avail = audit_expand(ab, new_len);
2044 if (!avail)
2045 return;
2046 }
2047
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07002048 ptr = skb_tail_pointer(skb);
Joe Perchesb8dbc322014-01-13 23:31:27 -08002049 for (i = 0; i < len; i++)
2050 ptr = hex_byte_pack_upper(ptr, buf[i]);
Steve Grubb168b7172005-05-19 10:24:22 +01002051 *ptr = 0;
2052 skb_put(skb, len << 1); /* new string is twice the old string */
83c7d092005-04-29 15:54:44 +01002053}
2054
Amy Griffis9c937dc2006-06-08 23:19:31 -04002055/*
2056 * Format a string of no more than slen characters into the audit buffer,
2057 * enclosed in quote marks.
2058 */
Eric Parisb556f8a2008-04-18 10:12:59 -04002059void audit_log_n_string(struct audit_buffer *ab, const char *string,
2060 size_t slen)
Amy Griffis9c937dc2006-06-08 23:19:31 -04002061{
2062 int avail, new_len;
2063 unsigned char *ptr;
2064 struct sk_buff *skb;
2065
Amy Griffis8ef2d302006-09-07 17:03:02 -04002066 if (!ab)
2067 return;
2068
Amy Griffis9c937dc2006-06-08 23:19:31 -04002069 BUG_ON(!ab->skb);
2070 skb = ab->skb;
2071 avail = skb_tailroom(skb);
2072 new_len = slen + 3; /* enclosing quotes + null terminator */
2073 if (new_len > avail) {
2074 avail = audit_expand(ab, new_len);
2075 if (!avail)
2076 return;
2077 }
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07002078 ptr = skb_tail_pointer(skb);
Amy Griffis9c937dc2006-06-08 23:19:31 -04002079 *ptr++ = '"';
2080 memcpy(ptr, string, slen);
2081 ptr += slen;
2082 *ptr++ = '"';
2083 *ptr = 0;
2084 skb_put(skb, slen + 2); /* don't include null terminator */
2085}
2086
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002087/**
Eric Parisde6bbd12008-01-07 14:31:58 -05002088 * audit_string_contains_control - does a string need to be logged in hex
Dave Jonesf706d5d2008-03-28 14:15:56 -07002089 * @string: string to be checked
2090 * @len: max length of the string to check
Eric Parisde6bbd12008-01-07 14:31:58 -05002091 */
Yaowei Bai9fcf8362015-11-04 08:23:51 -05002092bool audit_string_contains_control(const char *string, size_t len)
Eric Parisde6bbd12008-01-07 14:31:58 -05002093{
2094 const unsigned char *p;
Miloslav Trmacb3897f52009-03-19 09:48:27 -04002095 for (p = string; p < (const unsigned char *)string + len; p++) {
Vesa-Matti J Kari1d6c9642008-07-23 00:06:13 +03002096 if (*p == '"' || *p < 0x21 || *p > 0x7e)
Yaowei Bai9fcf8362015-11-04 08:23:51 -05002097 return true;
Eric Parisde6bbd12008-01-07 14:31:58 -05002098 }
Yaowei Bai9fcf8362015-11-04 08:23:51 -05002099 return false;
Eric Parisde6bbd12008-01-07 14:31:58 -05002100}
2101
2102/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07002103 * audit_log_n_untrustedstring - log a string that may contain random characters
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002104 * @ab: audit_buffer
Dave Jonesf706d5d2008-03-28 14:15:56 -07002105 * @len: length of string (not including trailing null)
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002106 * @string: string to be logged
2107 *
2108 * This code will escape a string that is passed to it if the string
2109 * contains a control character, unprintable character, double quote mark,
Steve Grubb168b7172005-05-19 10:24:22 +01002110 * or a space. Unescaped strings will start and end with a double quote mark.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002111 * Strings that are escaped are printed in hex (2 digits per char).
Amy Griffis9c937dc2006-06-08 23:19:31 -04002112 *
2113 * The caller specifies the number of characters in the string to log, which may
2114 * or may not be the entire string.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002115 */
Eric Parisb556f8a2008-04-18 10:12:59 -04002116void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
2117 size_t len)
83c7d092005-04-29 15:54:44 +01002118{
Eric Parisde6bbd12008-01-07 14:31:58 -05002119 if (audit_string_contains_control(string, len))
Eric Parisb556f8a2008-04-18 10:12:59 -04002120 audit_log_n_hex(ab, string, len);
Eric Parisde6bbd12008-01-07 14:31:58 -05002121 else
Eric Parisb556f8a2008-04-18 10:12:59 -04002122 audit_log_n_string(ab, string, len);
83c7d092005-04-29 15:54:44 +01002123}
2124
Amy Griffis9c937dc2006-06-08 23:19:31 -04002125/**
Miloslav Trmac522ed772007-07-15 23:40:56 -07002126 * audit_log_untrustedstring - log a string that may contain random characters
Amy Griffis9c937dc2006-06-08 23:19:31 -04002127 * @ab: audit_buffer
2128 * @string: string to be logged
2129 *
Miloslav Trmac522ed772007-07-15 23:40:56 -07002130 * Same as audit_log_n_untrustedstring(), except that strlen is used to
Amy Griffis9c937dc2006-06-08 23:19:31 -04002131 * determine string length.
2132 */
Eric Parisde6bbd12008-01-07 14:31:58 -05002133void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
Amy Griffis9c937dc2006-06-08 23:19:31 -04002134{
Eric Parisb556f8a2008-04-18 10:12:59 -04002135 audit_log_n_untrustedstring(ab, string, strlen(string));
Amy Griffis9c937dc2006-06-08 23:19:31 -04002136}
2137
Steve Grubb168b7172005-05-19 10:24:22 +01002138/* This is a helper-function to print the escaped d_path */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002139void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
Al Viro66b3fad2012-03-14 21:48:20 -04002140 const struct path *path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002141{
Jan Blunck44707fd2008-02-14 19:38:33 -08002142 char *p, *pathname;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002143
Chris Wright8fc61152005-05-06 15:54:17 +01002144 if (prefix)
Kees Cookc158a352012-01-06 14:07:10 -08002145 audit_log_format(ab, "%s", prefix);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002146
Steve Grubb168b7172005-05-19 10:24:22 +01002147 /* We will allow 11 spaces for ' (deleted)' to be appended */
Jan Blunck44707fd2008-02-14 19:38:33 -08002148 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
2149 if (!pathname) {
Richard Guy Briggsf1d9b232020-07-13 15:51:59 -04002150 audit_log_format(ab, "\"<no_memory>\"");
Steve Grubb168b7172005-05-19 10:24:22 +01002151 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002152 }
Jan Blunckcf28b482008-02-14 19:38:44 -08002153 p = d_path(path, pathname, PATH_MAX+11);
Steve Grubb168b7172005-05-19 10:24:22 +01002154 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
2155 /* FIXME: can we save some information here? */
Richard Guy Briggsf1d9b232020-07-13 15:51:59 -04002156 audit_log_format(ab, "\"<too_long>\"");
Daniel Walker5600b892007-10-18 03:06:10 -07002157 } else
Steve Grubb168b7172005-05-19 10:24:22 +01002158 audit_log_untrustedstring(ab, p);
Jan Blunck44707fd2008-02-14 19:38:33 -08002159 kfree(pathname);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002160}
2161
Eric Paris4d3fb702013-04-30 09:53:34 -04002162void audit_log_session_info(struct audit_buffer *ab)
2163{
Eric Paris4440e852013-11-27 17:35:17 -05002164 unsigned int sessionid = audit_get_sessionid(current);
Eric Paris4d3fb702013-04-30 09:53:34 -04002165 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
2166
Richard Guy Briggsa2c97da2018-11-16 16:30:10 -05002167 audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
Eric Paris4d3fb702013-04-30 09:53:34 -04002168}
2169
Eric Paris9d960982009-06-11 14:31:37 -04002170void audit_log_key(struct audit_buffer *ab, char *key)
2171{
2172 audit_log_format(ab, " key=");
2173 if (key)
2174 audit_log_untrustedstring(ab, key);
2175 else
2176 audit_log_format(ab, "(null)");
2177}
2178
Eric Parisb24a30a2013-04-30 15:30:32 -04002179int audit_log_task_context(struct audit_buffer *ab)
2180{
2181 char *ctx = NULL;
2182 unsigned len;
2183 int error;
2184 u32 sid;
2185
Paul Moore63269482021-09-29 11:01:21 -04002186 security_current_getsecid_subj(&sid);
Eric Parisb24a30a2013-04-30 15:30:32 -04002187 if (!sid)
2188 return 0;
2189
2190 error = security_secid_to_secctx(sid, &ctx, &len);
2191 if (error) {
2192 if (error != -EINVAL)
2193 goto error_path;
2194 return 0;
2195 }
2196
2197 audit_log_format(ab, " subj=%s", ctx);
2198 security_release_secctx(ctx, len);
2199 return 0;
2200
2201error_path:
2202 audit_panic("error in audit_log_task_context");
2203 return error;
2204}
2205EXPORT_SYMBOL(audit_log_task_context);
2206
Davidlohr Bueso4766b192015-02-22 18:20:00 -08002207void audit_log_d_path_exe(struct audit_buffer *ab,
2208 struct mm_struct *mm)
2209{
Davidlohr Bueso5b282552015-02-22 18:20:09 -08002210 struct file *exe_file;
Davidlohr Bueso4766b192015-02-22 18:20:00 -08002211
Davidlohr Bueso5b282552015-02-22 18:20:09 -08002212 if (!mm)
2213 goto out_null;
2214
2215 exe_file = get_mm_exe_file(mm);
2216 if (!exe_file)
2217 goto out_null;
2218
2219 audit_log_d_path(ab, " exe=", &exe_file->f_path);
2220 fput(exe_file);
2221 return;
2222out_null:
2223 audit_log_format(ab, " exe=(null)");
Davidlohr Bueso4766b192015-02-22 18:20:00 -08002224}
2225
Paul Moore2a1fe212018-11-26 18:40:07 -05002226struct tty_struct *audit_get_tty(void)
Richard Guy Briggs3f5be2d2016-06-28 12:07:50 -04002227{
2228 struct tty_struct *tty = NULL;
2229 unsigned long flags;
2230
Paul Moore2a1fe212018-11-26 18:40:07 -05002231 spin_lock_irqsave(&current->sighand->siglock, flags);
2232 if (current->signal)
2233 tty = tty_kref_get(current->signal->tty);
2234 spin_unlock_irqrestore(&current->sighand->siglock, flags);
Richard Guy Briggs3f5be2d2016-06-28 12:07:50 -04002235 return tty;
2236}
2237
2238void audit_put_tty(struct tty_struct *tty)
2239{
2240 tty_kref_put(tty);
2241}
2242
Paul Moore2a1fe212018-11-26 18:40:07 -05002243void audit_log_task_info(struct audit_buffer *ab)
Eric Parisb24a30a2013-04-30 15:30:32 -04002244{
2245 const struct cred *cred;
Paul Moore2a1fe212018-11-26 18:40:07 -05002246 char comm[sizeof(current->comm)];
Richard Guy Briggsdb0a6fb2016-04-21 14:14:01 -04002247 struct tty_struct *tty;
Eric Parisb24a30a2013-04-30 15:30:32 -04002248
2249 if (!ab)
2250 return;
2251
Eric Parisb24a30a2013-04-30 15:30:32 -04002252 cred = current_cred();
Paul Moore2a1fe212018-11-26 18:40:07 -05002253 tty = audit_get_tty();
Eric Parisb24a30a2013-04-30 15:30:32 -04002254 audit_log_format(ab,
Richard Guy Briggsc92cdeb2013-12-10 22:10:41 -05002255 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
Eric Parisb24a30a2013-04-30 15:30:32 -04002256 " euid=%u suid=%u fsuid=%u"
Richard Guy Briggs2f2ad102013-07-15 10:23:11 -04002257 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
Paul Moore2a1fe212018-11-26 18:40:07 -05002258 task_ppid_nr(current),
2259 task_tgid_nr(current),
2260 from_kuid(&init_user_ns, audit_get_loginuid(current)),
Eric Parisb24a30a2013-04-30 15:30:32 -04002261 from_kuid(&init_user_ns, cred->uid),
2262 from_kgid(&init_user_ns, cred->gid),
2263 from_kuid(&init_user_ns, cred->euid),
2264 from_kuid(&init_user_ns, cred->suid),
2265 from_kuid(&init_user_ns, cred->fsuid),
2266 from_kgid(&init_user_ns, cred->egid),
2267 from_kgid(&init_user_ns, cred->sgid),
2268 from_kgid(&init_user_ns, cred->fsgid),
Richard Guy Briggsdb0a6fb2016-04-21 14:14:01 -04002269 tty ? tty_name(tty) : "(none)",
Paul Moore2a1fe212018-11-26 18:40:07 -05002270 audit_get_sessionid(current));
Richard Guy Briggsdb0a6fb2016-04-21 14:14:01 -04002271 audit_put_tty(tty);
Eric Parisb24a30a2013-04-30 15:30:32 -04002272 audit_log_format(ab, " comm=");
Paul Moore2a1fe212018-11-26 18:40:07 -05002273 audit_log_untrustedstring(ab, get_task_comm(comm, current));
2274 audit_log_d_path_exe(ab, current->mm);
Eric Parisb24a30a2013-04-30 15:30:32 -04002275 audit_log_task_context(ab);
2276}
2277EXPORT_SYMBOL(audit_log_task_info);
2278
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002279/**
Kees Cook245d7362019-10-02 16:41:58 -07002280 * audit_log_path_denied - report a path restriction denial
2281 * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc)
2282 * @operation: specific operation name
Kees Cooka51d9ea2012-07-25 17:29:08 -07002283 */
Kees Cook245d7362019-10-02 16:41:58 -07002284void audit_log_path_denied(int type, const char *operation)
Kees Cooka51d9ea2012-07-25 17:29:08 -07002285{
2286 struct audit_buffer *ab;
2287
Richard Guy Briggs15564ff2018-02-14 11:18:21 -05002288 if (!audit_enabled || audit_dummy_context())
Eric Parisb24a30a2013-04-30 15:30:32 -04002289 return;
2290
Kees Cook245d7362019-10-02 16:41:58 -07002291 /* Generate log with subject, operation, outcome. */
2292 ab = audit_log_start(audit_context(), GFP_KERNEL, type);
Sasha Levind1c7d972012-10-04 19:57:31 -04002293 if (!ab)
Richard Guy Briggs45b578f2018-02-14 11:18:22 -05002294 return;
Eric Parisb24a30a2013-04-30 15:30:32 -04002295 audit_log_format(ab, "op=%s", operation);
Paul Moore2a1fe212018-11-26 18:40:07 -05002296 audit_log_task_info(ab);
Eric Parisb24a30a2013-04-30 15:30:32 -04002297 audit_log_format(ab, " res=0");
Kees Cooka51d9ea2012-07-25 17:29:08 -07002298 audit_log_end(ab);
2299}
2300
Richard Guy Briggs4b7d2482019-01-22 17:06:39 -05002301/* global counter which is incremented every time something logs in */
2302static atomic_t session_id = ATOMIC_INIT(0);
2303
2304static int audit_set_loginuid_perm(kuid_t loginuid)
2305{
2306 /* if we are unset, we don't need privs */
2307 if (!audit_loginuid_set(current))
2308 return 0;
2309 /* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/
2310 if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
2311 return -EPERM;
2312 /* it is set, you need permission */
2313 if (!capable(CAP_AUDIT_CONTROL))
2314 return -EPERM;
2315 /* reject if this is not an unset and we don't allow that */
2316 if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID)
2317 && uid_valid(loginuid))
2318 return -EPERM;
2319 return 0;
2320}
2321
2322static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
2323 unsigned int oldsessionid,
2324 unsigned int sessionid, int rc)
2325{
2326 struct audit_buffer *ab;
2327 uid_t uid, oldloginuid, loginuid;
2328 struct tty_struct *tty;
2329
2330 if (!audit_enabled)
2331 return;
2332
Richard Guy Briggs73e65b82019-03-19 15:23:29 -04002333 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
Richard Guy Briggs4b7d2482019-01-22 17:06:39 -05002334 if (!ab)
2335 return;
2336
2337 uid = from_kuid(&init_user_ns, task_uid(current));
2338 oldloginuid = from_kuid(&init_user_ns, koldloginuid);
Zheng Yongjuna1b861f2020-12-11 16:42:54 +08002339 loginuid = from_kuid(&init_user_ns, kloginuid);
Richard Guy Briggs4b7d2482019-01-22 17:06:39 -05002340 tty = audit_get_tty();
2341
2342 audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
2343 audit_log_task_context(ab);
2344 audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2345 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2346 oldsessionid, sessionid, !rc);
2347 audit_put_tty(tty);
2348 audit_log_end(ab);
2349}
2350
2351/**
2352 * audit_set_loginuid - set current task's loginuid
2353 * @loginuid: loginuid value
2354 *
2355 * Returns 0.
2356 *
2357 * Called (set) from fs/proc/base.c::proc_loginuid_write().
2358 */
2359int audit_set_loginuid(kuid_t loginuid)
2360{
2361 unsigned int oldsessionid, sessionid = AUDIT_SID_UNSET;
2362 kuid_t oldloginuid;
2363 int rc;
2364
2365 oldloginuid = audit_get_loginuid(current);
2366 oldsessionid = audit_get_sessionid(current);
2367
2368 rc = audit_set_loginuid_perm(loginuid);
2369 if (rc)
2370 goto out;
2371
2372 /* are we setting or clearing? */
2373 if (uid_valid(loginuid)) {
2374 sessionid = (unsigned int)atomic_inc_return(&session_id);
2375 if (unlikely(sessionid == AUDIT_SID_UNSET))
2376 sessionid = (unsigned int)atomic_inc_return(&session_id);
2377 }
2378
2379 current->sessionid = sessionid;
2380 current->loginuid = loginuid;
2381out:
2382 audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2383 return rc;
2384}
2385
Kees Cooka51d9ea2012-07-25 17:29:08 -07002386/**
Richard Guy Briggsb48345a2019-05-10 12:21:49 -04002387 * audit_signal_info - record signal info for shutting down audit subsystem
2388 * @sig: signal value
2389 * @t: task being signaled
2390 *
2391 * If the audit subsystem is being terminated, record the task (pid)
2392 * and uid that is doing that.
2393 */
2394int audit_signal_info(int sig, struct task_struct *t)
2395{
2396 kuid_t uid = current_uid(), auid;
2397
2398 if (auditd_test_task(t) &&
2399 (sig == SIGTERM || sig == SIGHUP ||
2400 sig == SIGUSR1 || sig == SIGUSR2)) {
2401 audit_sig_pid = task_tgid_nr(current);
2402 auid = audit_get_loginuid(current);
2403 if (uid_valid(auid))
2404 audit_sig_uid = auid;
2405 else
2406 audit_sig_uid = uid;
Paul Moore63269482021-09-29 11:01:21 -04002407 security_current_getsecid_subj(&audit_sig_sid);
Richard Guy Briggsb48345a2019-05-10 12:21:49 -04002408 }
2409
2410 return audit_signal_info_syscall(t);
2411}
2412
2413/**
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002414 * audit_log_end - end one audit record
2415 * @ab: the audit_buffer
2416 *
Paul Moore4aa838722016-11-29 16:53:24 -05002417 * We can not do a netlink send inside an irq context because it blocks (last
2418 * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
Davidlohr Buesoc1de4462021-01-14 16:12:01 -08002419 * queue and a kthread is scheduled to remove them from the queue outside the
Paul Moore4aa838722016-11-29 16:53:24 -05002420 * irq context. May be called in any context.
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002421 */
David Woodhouseb7d11252005-05-19 10:56:58 +01002422void audit_log_end(struct audit_buffer *ab)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002423{
Paul Moore5b523302017-03-21 11:26:35 -04002424 struct sk_buff *skb;
2425 struct nlmsghdr *nlh;
2426
Linus Torvalds1da177e2005-04-16 15:20:36 -07002427 if (!ab)
2428 return;
Paul Moore5b523302017-03-21 11:26:35 -04002429
2430 if (audit_rate_check()) {
2431 skb = ab->skb;
Eric Parisf3d357b2008-04-18 10:02:28 -04002432 ab->skb = NULL;
Paul Moore5b523302017-03-21 11:26:35 -04002433
2434 /* setup the netlink header, see the comments in
2435 * kauditd_send_multicast_skb() for length quirks */
2436 nlh = nlmsg_hdr(skb);
2437 nlh->nlmsg_len = skb->len - NLMSG_HDRLEN;
2438
2439 /* queue the netlink packet and poke the kauditd thread */
2440 skb_queue_tail(&audit_queue, skb);
2441 wake_up_interruptible(&kauditd_wait);
2442 } else
2443 audit_log_lost("rate limit exceeded");
2444
Chris Wright16e19042005-05-06 15:53:34 +01002445 audit_buffer_free(ab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002446}
2447
Randy Dunlapb0dd25a2005-09-13 12:47:11 -07002448/**
2449 * audit_log - Log an audit record
2450 * @ctx: audit context
2451 * @gfp_mask: type of allocation
2452 * @type: audit message type
2453 * @fmt: format string to use
2454 * @...: variable parameters matching the format string
2455 *
2456 * This is a convenience function that calls audit_log_start,
2457 * audit_log_vformat, and audit_log_end. It may be called
2458 * in any context.
2459 */
Daniel Walker5600b892007-10-18 03:06:10 -07002460void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
David Woodhouse9ad9ad32005-06-22 15:04:33 +01002461 const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002462{
2463 struct audit_buffer *ab;
2464 va_list args;
2465
David Woodhouse9ad9ad32005-06-22 15:04:33 +01002466 ab = audit_log_start(ctx, gfp_mask, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002467 if (ab) {
2468 va_start(args, fmt);
2469 audit_log_vformat(ab, fmt, args);
2470 va_end(args);
2471 audit_log_end(ab);
2472 }
2473}
lorenzo@gnu.orgbf45da92006-03-09 00:33:47 +01002474
2475EXPORT_SYMBOL(audit_log_start);
2476EXPORT_SYMBOL(audit_log_end);
2477EXPORT_SYMBOL(audit_log_format);
2478EXPORT_SYMBOL(audit_log);