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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
85c8721f | 2 | /* audit.c -- Auditing support |
1da177e4 LT |
3 | * Gateway between the kernel (e.g., selinux) and the user-space audit daemon. |
4 | * System-call specific features have moved to auditsc.c | |
5 | * | |
6a01b07f | 6 | * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina. |
1da177e4 LT |
7 | * All Rights Reserved. |
8 | * | |
1da177e4 LT |
9 | * Written by Rickard E. (Rik) Faith <faith@redhat.com> |
10 | * | |
d7a96f3a | 11 | * Goals: 1) Integrate fully with Security Modules. |
1da177e4 LT |
12 | * 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 | * | |
d590dca6 RGB |
28 | * Audit userspace, documentation, tests, and bug/issue trackers: |
29 | * https://github.com/linux-audit | |
1da177e4 LT |
30 | */ |
31 | ||
d957f7b7 JP |
32 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
33 | ||
5b282552 | 34 | #include <linux/file.h> |
1da177e4 | 35 | #include <linux/init.h> |
7153e402 | 36 | #include <linux/types.h> |
60063497 | 37 | #include <linux/atomic.h> |
1da177e4 | 38 | #include <linux/mm.h> |
9984de1a | 39 | #include <linux/export.h> |
5a0e3ad6 | 40 | #include <linux/slab.h> |
b7d11258 DW |
41 | #include <linux/err.h> |
42 | #include <linux/kthread.h> | |
46e959ea | 43 | #include <linux/kernel.h> |
b24a30a7 | 44 | #include <linux/syscalls.h> |
5b52330b PM |
45 | #include <linux/spinlock.h> |
46 | #include <linux/rcupdate.h> | |
47 | #include <linux/mutex.h> | |
48 | #include <linux/gfp.h> | |
b6c7c115 | 49 | #include <linux/pid.h> |
1da177e4 LT |
50 | |
51 | #include <linux/audit.h> | |
52 | ||
53 | #include <net/sock.h> | |
93315ed6 | 54 | #include <net/netlink.h> |
1da177e4 | 55 | #include <linux/skbuff.h> |
131ad62d MDF |
56 | #ifdef CONFIG_SECURITY |
57 | #include <linux/security.h> | |
58 | #endif | |
7dfb7103 | 59 | #include <linux/freezer.h> |
34e36d8e | 60 | #include <linux/pid_namespace.h> |
33faba7f | 61 | #include <net/netns/generic.h> |
3dc7e315 DG |
62 | |
63 | #include "audit.h" | |
1da177e4 | 64 | |
a3f07114 | 65 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 66 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
67 | #define AUDIT_DISABLED -1 |
68 | #define AUDIT_UNINITIALIZED 0 | |
69 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
70 | static int audit_initialized; |
71 | ||
173743dd | 72 | u32 audit_enabled = AUDIT_OFF; |
b3b4fdf6 | 73 | bool audit_ever_enabled = !!AUDIT_OFF; |
1da177e4 | 74 | |
ae9d67af JE |
75 | EXPORT_SYMBOL_GPL(audit_enabled); |
76 | ||
1da177e4 | 77 | /* Default state when kernel boots without any parameters. */ |
173743dd | 78 | static u32 audit_default = AUDIT_OFF; |
1da177e4 LT |
79 | |
80 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
3e1d0bb6 | 81 | static u32 audit_failure = AUDIT_FAIL_PRINTK; |
1da177e4 | 82 | |
5b52330b PM |
83 | /* private audit network namespace index */ |
84 | static unsigned int audit_net_id; | |
85 | ||
86 | /** | |
87 | * struct audit_net - audit private network namespace data | |
88 | * @sk: communication socket | |
89 | */ | |
90 | struct audit_net { | |
91 | struct sock *sk; | |
92 | }; | |
93 | ||
94 | /** | |
95 | * struct auditd_connection - kernel/auditd connection state | |
96 | * @pid: auditd PID | |
97 | * @portid: netlink portid | |
98 | * @net: the associated network namespace | |
48d0e023 | 99 | * @rcu: RCU head |
5b52330b PM |
100 | * |
101 | * Description: | |
102 | * This struct is RCU protected; you must either hold the RCU lock for reading | |
48d0e023 | 103 | * or the associated spinlock for writing. |
75c0371a | 104 | */ |
cb5172d9 | 105 | struct auditd_connection { |
b6c7c115 | 106 | struct pid *pid; |
5b52330b PM |
107 | u32 portid; |
108 | struct net *net; | |
48d0e023 | 109 | struct rcu_head rcu; |
cb5172d9 AG |
110 | }; |
111 | static struct auditd_connection __rcu *auditd_conn; | |
48d0e023 | 112 | static DEFINE_SPINLOCK(auditd_conn_lock); |
1da177e4 | 113 | |
b0dd25a8 | 114 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
115 | * to that number per second. This prevents DoS attacks, but results in |
116 | * audit records being dropped. */ | |
3e1d0bb6 | 117 | static u32 audit_rate_limit; |
1da177e4 | 118 | |
40c0775e RGB |
119 | /* Number of outstanding audit_buffers allowed. |
120 | * When set to zero, this means unlimited. */ | |
3e1d0bb6 | 121 | static u32 audit_backlog_limit = 64; |
e789e561 | 122 | #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ) |
3e1d0bb6 | 123 | static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; |
1da177e4 | 124 | |
c2f0c7c3 | 125 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 126 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 127 | pid_t audit_sig_pid = -1; |
e1396065 | 128 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 129 | |
1da177e4 LT |
130 | /* Records can be lost in several ways: |
131 | 0) [suppressed in audit_alloc] | |
132 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
133 | 2) out of memory in audit_log_move [alloc_skb] | |
134 | 3) suppressed due to audit_rate_limit | |
135 | 4) suppressed due to audit_backlog_limit | |
136 | */ | |
92c82e8a | 137 | static atomic_t audit_lost = ATOMIC_INIT(0); |
1da177e4 | 138 | |
f368c07d AG |
139 | /* Hash for inode-based rules */ |
140 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
141 | ||
8cc96382 | 142 | static struct kmem_cache *audit_buffer_cache; |
1da177e4 | 143 | |
c6480207 | 144 | /* queue msgs to send via kauditd_task */ |
af8b824f | 145 | static struct sk_buff_head audit_queue; |
c6480207 PM |
146 | /* queue msgs due to temporary unicast send problems */ |
147 | static struct sk_buff_head audit_retry_queue; | |
148 | /* queue msgs waiting for new auditd connection */ | |
af8b824f | 149 | static struct sk_buff_head audit_hold_queue; |
c6480207 PM |
150 | |
151 | /* queue servicing thread */ | |
b7d11258 DW |
152 | static struct task_struct *kauditd_task; |
153 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
c6480207 PM |
154 | |
155 | /* waitqueue for callers who are blocked on the audit backlog */ | |
9ad9ad38 | 156 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 157 | |
b0fed402 EP |
158 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
159 | .mask = -1, | |
160 | .features = 0, | |
161 | .lock = 0,}; | |
162 | ||
21b85c31 | 163 | static char *audit_feature_names[2] = { |
d040e5af | 164 | "only_unset_loginuid", |
21b85c31 | 165 | "loginuid_immutable", |
b0fed402 EP |
166 | }; |
167 | ||
ce423631 PM |
168 | /** |
169 | * struct audit_ctl_mutex - serialize requests from userspace | |
170 | * @lock: the mutex used for locking | |
171 | * @owner: the task which owns the lock | |
172 | * | |
173 | * Description: | |
174 | * This is the lock struct used to ensure we only process userspace requests | |
175 | * in an orderly fashion. We can't simply use a mutex/lock here because we | |
176 | * need to track lock ownership so we don't end up blocking the lock owner in | |
177 | * audit_log_start() or similar. | |
178 | */ | |
179 | static struct audit_ctl_mutex { | |
180 | struct mutex lock; | |
181 | void *owner; | |
182 | } audit_cmd_mutex; | |
1da177e4 LT |
183 | |
184 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
185 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
186 | * should be at least that large. */ | |
187 | #define AUDIT_BUFSIZ 1024 | |
188 | ||
1da177e4 LT |
189 | /* The audit_buffer is used when formatting an audit record. The caller |
190 | * locks briefly to get the record off the freelist or to allocate the | |
191 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
192 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
193 | * use simultaneously. */ | |
194 | struct audit_buffer { | |
8fc6115c | 195 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 196 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 197 | gfp_t gfp_mask; |
1da177e4 LT |
198 | }; |
199 | ||
f09ac9db | 200 | struct audit_reply { |
f9441639 | 201 | __u32 portid; |
638a0fd2 | 202 | struct net *net; |
f09ac9db EP |
203 | struct sk_buff *skb; |
204 | }; | |
205 | ||
5b52330b PM |
206 | /** |
207 | * auditd_test_task - Check to see if a given task is an audit daemon | |
208 | * @task: the task to check | |
209 | * | |
210 | * Description: | |
211 | * Return 1 if the task is a registered audit daemon, 0 otherwise. | |
212 | */ | |
b6c7c115 | 213 | int auditd_test_task(struct task_struct *task) |
5b52330b PM |
214 | { |
215 | int rc; | |
48d0e023 | 216 | struct auditd_connection *ac; |
5b52330b PM |
217 | |
218 | rcu_read_lock(); | |
48d0e023 PM |
219 | ac = rcu_dereference(auditd_conn); |
220 | rc = (ac && ac->pid == task_tgid(task) ? 1 : 0); | |
5b52330b PM |
221 | rcu_read_unlock(); |
222 | ||
223 | return rc; | |
224 | } | |
225 | ||
ce423631 PM |
226 | /** |
227 | * audit_ctl_lock - Take the audit control lock | |
228 | */ | |
229 | void audit_ctl_lock(void) | |
230 | { | |
231 | mutex_lock(&audit_cmd_mutex.lock); | |
232 | audit_cmd_mutex.owner = current; | |
233 | } | |
234 | ||
235 | /** | |
236 | * audit_ctl_unlock - Drop the audit control lock | |
237 | */ | |
238 | void audit_ctl_unlock(void) | |
239 | { | |
240 | audit_cmd_mutex.owner = NULL; | |
241 | mutex_unlock(&audit_cmd_mutex.lock); | |
242 | } | |
243 | ||
244 | /** | |
245 | * audit_ctl_owner_current - Test to see if the current task owns the lock | |
246 | * | |
247 | * Description: | |
248 | * Return true if the current task owns the audit control lock, false if it | |
249 | * doesn't own the lock. | |
250 | */ | |
251 | static bool audit_ctl_owner_current(void) | |
252 | { | |
253 | return (current == audit_cmd_mutex.owner); | |
254 | } | |
255 | ||
b6c7c115 PM |
256 | /** |
257 | * auditd_pid_vnr - Return the auditd PID relative to the namespace | |
b6c7c115 PM |
258 | * |
259 | * Description: | |
48d0e023 | 260 | * Returns the PID in relation to the namespace, 0 on failure. |
b6c7c115 | 261 | */ |
48d0e023 | 262 | static pid_t auditd_pid_vnr(void) |
b6c7c115 PM |
263 | { |
264 | pid_t pid; | |
48d0e023 | 265 | const struct auditd_connection *ac; |
b6c7c115 PM |
266 | |
267 | rcu_read_lock(); | |
48d0e023 PM |
268 | ac = rcu_dereference(auditd_conn); |
269 | if (!ac || !ac->pid) | |
b6c7c115 PM |
270 | pid = 0; |
271 | else | |
48d0e023 | 272 | pid = pid_vnr(ac->pid); |
b6c7c115 PM |
273 | rcu_read_unlock(); |
274 | ||
275 | return pid; | |
276 | } | |
277 | ||
5b52330b PM |
278 | /** |
279 | * audit_get_sk - Return the audit socket for the given network namespace | |
280 | * @net: the destination network namespace | |
281 | * | |
282 | * Description: | |
283 | * Returns the sock pointer if valid, NULL otherwise. The caller must ensure | |
284 | * that a reference is held for the network namespace while the sock is in use. | |
285 | */ | |
286 | static struct sock *audit_get_sk(const struct net *net) | |
287 | { | |
288 | struct audit_net *aunet; | |
289 | ||
290 | if (!net) | |
291 | return NULL; | |
292 | ||
293 | aunet = net_generic(net, audit_net_id); | |
294 | return aunet->sk; | |
295 | } | |
296 | ||
8c8570fb | 297 | void audit_panic(const char *message) |
1da177e4 | 298 | { |
d957f7b7 | 299 | switch (audit_failure) { |
1da177e4 LT |
300 | case AUDIT_FAIL_SILENT: |
301 | break; | |
302 | case AUDIT_FAIL_PRINTK: | |
320f1b1e | 303 | if (printk_ratelimit()) |
d957f7b7 | 304 | pr_err("%s\n", message); |
1da177e4 LT |
305 | break; |
306 | case AUDIT_FAIL_PANIC: | |
5b52330b | 307 | panic("audit: %s\n", message); |
1da177e4 LT |
308 | break; |
309 | } | |
310 | } | |
311 | ||
312 | static inline int audit_rate_check(void) | |
313 | { | |
314 | static unsigned long last_check = 0; | |
315 | static int messages = 0; | |
316 | static DEFINE_SPINLOCK(lock); | |
317 | unsigned long flags; | |
318 | unsigned long now; | |
319 | unsigned long elapsed; | |
320 | int retval = 0; | |
321 | ||
322 | if (!audit_rate_limit) return 1; | |
323 | ||
324 | spin_lock_irqsave(&lock, flags); | |
325 | if (++messages < audit_rate_limit) { | |
326 | retval = 1; | |
327 | } else { | |
328 | now = jiffies; | |
329 | elapsed = now - last_check; | |
330 | if (elapsed > HZ) { | |
331 | last_check = now; | |
332 | messages = 0; | |
333 | retval = 1; | |
334 | } | |
335 | } | |
336 | spin_unlock_irqrestore(&lock, flags); | |
337 | ||
338 | return retval; | |
339 | } | |
340 | ||
b0dd25a8 RD |
341 | /** |
342 | * audit_log_lost - conditionally log lost audit message event | |
343 | * @message: the message stating reason for lost audit message | |
344 | * | |
345 | * Emit at least 1 message per second, even if audit_rate_check is | |
346 | * throttling. | |
347 | * Always increment the lost messages counter. | |
348 | */ | |
1da177e4 LT |
349 | void audit_log_lost(const char *message) |
350 | { | |
351 | static unsigned long last_msg = 0; | |
352 | static DEFINE_SPINLOCK(lock); | |
353 | unsigned long flags; | |
354 | unsigned long now; | |
355 | int print; | |
356 | ||
357 | atomic_inc(&audit_lost); | |
358 | ||
359 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
360 | ||
361 | if (!print) { | |
362 | spin_lock_irqsave(&lock, flags); | |
363 | now = jiffies; | |
364 | if (now - last_msg > HZ) { | |
365 | print = 1; | |
366 | last_msg = now; | |
367 | } | |
368 | spin_unlock_irqrestore(&lock, flags); | |
369 | } | |
370 | ||
371 | if (print) { | |
320f1b1e | 372 | if (printk_ratelimit()) |
3e1d0bb6 | 373 | pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n", |
320f1b1e EP |
374 | atomic_read(&audit_lost), |
375 | audit_rate_limit, | |
376 | audit_backlog_limit); | |
1da177e4 LT |
377 | audit_panic(message); |
378 | } | |
1da177e4 LT |
379 | } |
380 | ||
3e1d0bb6 | 381 | static int audit_log_config_change(char *function_name, u32 new, u32 old, |
2532386f | 382 | int allow_changes) |
1da177e4 | 383 | { |
1a6b9f23 EP |
384 | struct audit_buffer *ab; |
385 | int rc = 0; | |
ce29b682 | 386 | |
626abcd1 | 387 | ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
388 | if (unlikely(!ab)) |
389 | return rc; | |
53fc7a01 | 390 | audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old); |
4d3fb709 | 391 | audit_log_session_info(ab); |
b122c376 EP |
392 | rc = audit_log_task_context(ab); |
393 | if (rc) | |
394 | allow_changes = 0; /* Something weird, deny request */ | |
1a6b9f23 EP |
395 | audit_log_format(ab, " res=%d", allow_changes); |
396 | audit_log_end(ab); | |
6a01b07f | 397 | return rc; |
1da177e4 LT |
398 | } |
399 | ||
3e1d0bb6 | 400 | static int audit_do_config_change(char *function_name, u32 *to_change, u32 new) |
1da177e4 | 401 | { |
3e1d0bb6 JP |
402 | int allow_changes, rc = 0; |
403 | u32 old = *to_change; | |
6a01b07f SG |
404 | |
405 | /* check if we are locked */ | |
1a6b9f23 EP |
406 | if (audit_enabled == AUDIT_LOCKED) |
407 | allow_changes = 0; | |
6a01b07f | 408 | else |
1a6b9f23 | 409 | allow_changes = 1; |
ce29b682 | 410 | |
1a6b9f23 | 411 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 412 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
413 | if (rc) |
414 | allow_changes = 0; | |
6a01b07f | 415 | } |
6a01b07f SG |
416 | |
417 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
418 | if (allow_changes == 1) |
419 | *to_change = new; | |
6a01b07f SG |
420 | /* Not allowed, update reason */ |
421 | else if (rc == 0) | |
422 | rc = -EPERM; | |
423 | return rc; | |
1da177e4 LT |
424 | } |
425 | ||
3e1d0bb6 | 426 | static int audit_set_rate_limit(u32 limit) |
1da177e4 | 427 | { |
dc9eb698 | 428 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 429 | } |
ce29b682 | 430 | |
3e1d0bb6 | 431 | static int audit_set_backlog_limit(u32 limit) |
1a6b9f23 | 432 | { |
dc9eb698 | 433 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 434 | } |
6a01b07f | 435 | |
3e1d0bb6 | 436 | static int audit_set_backlog_wait_time(u32 timeout) |
51cc83f0 RGB |
437 | { |
438 | return audit_do_config_change("audit_backlog_wait_time", | |
31975424 | 439 | &audit_backlog_wait_time, timeout); |
51cc83f0 RGB |
440 | } |
441 | ||
3e1d0bb6 | 442 | static int audit_set_enabled(u32 state) |
1a6b9f23 | 443 | { |
b593d384 | 444 | int rc; |
724e7bfc | 445 | if (state > AUDIT_LOCKED) |
1a6b9f23 | 446 | return -EINVAL; |
6a01b07f | 447 | |
dc9eb698 | 448 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
449 | if (!rc) |
450 | audit_ever_enabled |= !!state; | |
451 | ||
452 | return rc; | |
1da177e4 LT |
453 | } |
454 | ||
3e1d0bb6 | 455 | static int audit_set_failure(u32 state) |
1da177e4 | 456 | { |
1da177e4 LT |
457 | if (state != AUDIT_FAIL_SILENT |
458 | && state != AUDIT_FAIL_PRINTK | |
459 | && state != AUDIT_FAIL_PANIC) | |
460 | return -EINVAL; | |
ce29b682 | 461 | |
dc9eb698 | 462 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
463 | } |
464 | ||
48d0e023 PM |
465 | /** |
466 | * auditd_conn_free - RCU helper to release an auditd connection struct | |
467 | * @rcu: RCU head | |
468 | * | |
469 | * Description: | |
470 | * Drop any references inside the auditd connection tracking struct and free | |
471 | * the memory. | |
472 | */ | |
447a5647 JP |
473 | static void auditd_conn_free(struct rcu_head *rcu) |
474 | { | |
48d0e023 PM |
475 | struct auditd_connection *ac; |
476 | ||
477 | ac = container_of(rcu, struct auditd_connection, rcu); | |
478 | put_pid(ac->pid); | |
479 | put_net(ac->net); | |
480 | kfree(ac); | |
447a5647 | 481 | } |
48d0e023 | 482 | |
5b52330b PM |
483 | /** |
484 | * auditd_set - Set/Reset the auditd connection state | |
485 | * @pid: auditd PID | |
486 | * @portid: auditd netlink portid | |
487 | * @net: auditd network namespace pointer | |
488 | * | |
489 | * Description: | |
490 | * This function will obtain and drop network namespace references as | |
48d0e023 | 491 | * necessary. Returns zero on success, negative values on failure. |
5b52330b | 492 | */ |
48d0e023 | 493 | static int auditd_set(struct pid *pid, u32 portid, struct net *net) |
5b52330b PM |
494 | { |
495 | unsigned long flags; | |
48d0e023 | 496 | struct auditd_connection *ac_old, *ac_new; |
5b52330b | 497 | |
48d0e023 PM |
498 | if (!pid || !net) |
499 | return -EINVAL; | |
500 | ||
501 | ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL); | |
502 | if (!ac_new) | |
503 | return -ENOMEM; | |
504 | ac_new->pid = get_pid(pid); | |
505 | ac_new->portid = portid; | |
506 | ac_new->net = get_net(net); | |
507 | ||
508 | spin_lock_irqsave(&auditd_conn_lock, flags); | |
509 | ac_old = rcu_dereference_protected(auditd_conn, | |
510 | lockdep_is_held(&auditd_conn_lock)); | |
511 | rcu_assign_pointer(auditd_conn, ac_new); | |
512 | spin_unlock_irqrestore(&auditd_conn_lock, flags); | |
513 | ||
514 | if (ac_old) | |
515 | call_rcu(&ac_old->rcu, auditd_conn_free); | |
516 | ||
517 | return 0; | |
5b52330b PM |
518 | } |
519 | ||
5b52330b PM |
520 | /** |
521 | * kauditd_print_skb - Print the audit record to the ring buffer | |
522 | * @skb: audit record | |
523 | * | |
524 | * Whatever the reason, this packet may not make it to the auditd connection | |
525 | * so write it via printk so the information isn't completely lost. | |
038cbcf6 | 526 | */ |
af8b824f | 527 | static void kauditd_printk_skb(struct sk_buff *skb) |
038cbcf6 EP |
528 | { |
529 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 530 | char *data = nlmsg_data(nlh); |
038cbcf6 | 531 | |
5b52330b PM |
532 | if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit()) |
533 | pr_notice("type=%d %s\n", nlh->nlmsg_type, data); | |
534 | } | |
535 | ||
536 | /** | |
537 | * kauditd_rehold_skb - Handle a audit record send failure in the hold queue | |
538 | * @skb: audit record | |
539 | * | |
540 | * Description: | |
541 | * This should only be used by the kauditd_thread when it fails to flush the | |
542 | * hold queue. | |
543 | */ | |
544 | static void kauditd_rehold_skb(struct sk_buff *skb) | |
545 | { | |
546 | /* put the record back in the queue at the same place */ | |
547 | skb_queue_head(&audit_hold_queue, skb); | |
c6480207 PM |
548 | } |
549 | ||
550 | /** | |
551 | * kauditd_hold_skb - Queue an audit record, waiting for auditd | |
552 | * @skb: audit record | |
553 | * | |
554 | * Description: | |
555 | * Queue the audit record, waiting for an instance of auditd. When this | |
556 | * function is called we haven't given up yet on sending the record, but things | |
557 | * are not looking good. The first thing we want to do is try to write the | |
558 | * record via printk and then see if we want to try and hold on to the record | |
559 | * and queue it, if we have room. If we want to hold on to the record, but we | |
560 | * don't have room, record a record lost message. | |
561 | */ | |
562 | static void kauditd_hold_skb(struct sk_buff *skb) | |
563 | { | |
564 | /* at this point it is uncertain if we will ever send this to auditd so | |
565 | * try to send the message via printk before we go any further */ | |
566 | kauditd_printk_skb(skb); | |
567 | ||
568 | /* can we just silently drop the message? */ | |
569 | if (!audit_default) { | |
570 | kfree_skb(skb); | |
571 | return; | |
572 | } | |
573 | ||
574 | /* if we have room, queue the message */ | |
575 | if (!audit_backlog_limit || | |
576 | skb_queue_len(&audit_hold_queue) < audit_backlog_limit) { | |
577 | skb_queue_tail(&audit_hold_queue, skb); | |
578 | return; | |
579 | } | |
038cbcf6 | 580 | |
c6480207 PM |
581 | /* we have no other options - drop the message */ |
582 | audit_log_lost("kauditd hold queue overflow"); | |
583 | kfree_skb(skb); | |
038cbcf6 EP |
584 | } |
585 | ||
c6480207 PM |
586 | /** |
587 | * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd | |
588 | * @skb: audit record | |
589 | * | |
590 | * Description: | |
591 | * Not as serious as kauditd_hold_skb() as we still have a connected auditd, | |
592 | * but for some reason we are having problems sending it audit records so | |
593 | * queue the given record and attempt to resend. | |
594 | */ | |
595 | static void kauditd_retry_skb(struct sk_buff *skb) | |
f3d357b0 | 596 | { |
c6480207 PM |
597 | /* NOTE: because records should only live in the retry queue for a |
598 | * short period of time, before either being sent or moved to the hold | |
599 | * queue, we don't currently enforce a limit on this queue */ | |
600 | skb_queue_tail(&audit_retry_queue, skb); | |
601 | } | |
32a1dbae | 602 | |
264d5096 PM |
603 | /** |
604 | * auditd_reset - Disconnect the auditd connection | |
c81be52a | 605 | * @ac: auditd connection state |
264d5096 PM |
606 | * |
607 | * Description: | |
608 | * Break the auditd/kauditd connection and move all the queued records into the | |
c81be52a PM |
609 | * hold queue in case auditd reconnects. It is important to note that the @ac |
610 | * pointer should never be dereferenced inside this function as it may be NULL | |
611 | * or invalid, you can only compare the memory address! If @ac is NULL then | |
612 | * the connection will always be reset. | |
264d5096 | 613 | */ |
c81be52a | 614 | static void auditd_reset(const struct auditd_connection *ac) |
264d5096 | 615 | { |
48d0e023 | 616 | unsigned long flags; |
264d5096 | 617 | struct sk_buff *skb; |
48d0e023 | 618 | struct auditd_connection *ac_old; |
264d5096 PM |
619 | |
620 | /* if it isn't already broken, break the connection */ | |
48d0e023 PM |
621 | spin_lock_irqsave(&auditd_conn_lock, flags); |
622 | ac_old = rcu_dereference_protected(auditd_conn, | |
623 | lockdep_is_held(&auditd_conn_lock)); | |
c81be52a PM |
624 | if (ac && ac != ac_old) { |
625 | /* someone already registered a new auditd connection */ | |
626 | spin_unlock_irqrestore(&auditd_conn_lock, flags); | |
627 | return; | |
628 | } | |
48d0e023 PM |
629 | rcu_assign_pointer(auditd_conn, NULL); |
630 | spin_unlock_irqrestore(&auditd_conn_lock, flags); | |
631 | ||
632 | if (ac_old) | |
633 | call_rcu(&ac_old->rcu, auditd_conn_free); | |
264d5096 | 634 | |
cd33f5f2 PM |
635 | /* flush the retry queue to the hold queue, but don't touch the main |
636 | * queue since we need to process that normally for multicast */ | |
264d5096 PM |
637 | while ((skb = skb_dequeue(&audit_retry_queue))) |
638 | kauditd_hold_skb(skb); | |
264d5096 PM |
639 | } |
640 | ||
c6480207 | 641 | /** |
5b52330b PM |
642 | * auditd_send_unicast_skb - Send a record via unicast to auditd |
643 | * @skb: audit record | |
c6480207 PM |
644 | * |
645 | * Description: | |
5b52330b PM |
646 | * Send a skb to the audit daemon, returns positive/zero values on success and |
647 | * negative values on failure; in all cases the skb will be consumed by this | |
648 | * function. If the send results in -ECONNREFUSED the connection with auditd | |
649 | * will be reset. This function may sleep so callers should not hold any locks | |
650 | * where this would cause a problem. | |
c6480207 | 651 | */ |
5b52330b | 652 | static int auditd_send_unicast_skb(struct sk_buff *skb) |
c6480207 | 653 | { |
5b52330b PM |
654 | int rc; |
655 | u32 portid; | |
656 | struct net *net; | |
657 | struct sock *sk; | |
48d0e023 | 658 | struct auditd_connection *ac; |
5b52330b PM |
659 | |
660 | /* NOTE: we can't call netlink_unicast while in the RCU section so | |
661 | * take a reference to the network namespace and grab local | |
662 | * copies of the namespace, the sock, and the portid; the | |
663 | * namespace and sock aren't going to go away while we hold a | |
664 | * reference and if the portid does become invalid after the RCU | |
665 | * section netlink_unicast() should safely return an error */ | |
666 | ||
667 | rcu_read_lock(); | |
48d0e023 PM |
668 | ac = rcu_dereference(auditd_conn); |
669 | if (!ac) { | |
5b52330b | 670 | rcu_read_unlock(); |
b0659ae5 | 671 | kfree_skb(skb); |
5b52330b PM |
672 | rc = -ECONNREFUSED; |
673 | goto err; | |
533c7b69 | 674 | } |
48d0e023 | 675 | net = get_net(ac->net); |
5b52330b | 676 | sk = audit_get_sk(net); |
48d0e023 | 677 | portid = ac->portid; |
5b52330b | 678 | rcu_read_unlock(); |
c6480207 | 679 | |
5b52330b PM |
680 | rc = netlink_unicast(sk, skb, portid, 0); |
681 | put_net(net); | |
682 | if (rc < 0) | |
683 | goto err; | |
684 | ||
685 | return rc; | |
686 | ||
687 | err: | |
c81be52a PM |
688 | if (ac && rc == -ECONNREFUSED) |
689 | auditd_reset(ac); | |
5b52330b | 690 | return rc; |
c6480207 PM |
691 | } |
692 | ||
693 | /** | |
5b52330b PM |
694 | * kauditd_send_queue - Helper for kauditd_thread to flush skb queues |
695 | * @sk: the sending sock | |
696 | * @portid: the netlink destination | |
697 | * @queue: the skb queue to process | |
698 | * @retry_limit: limit on number of netlink unicast failures | |
699 | * @skb_hook: per-skb hook for additional processing | |
700 | * @err_hook: hook called if the skb fails the netlink unicast send | |
701 | * | |
702 | * Description: | |
703 | * Run through the given queue and attempt to send the audit records to auditd, | |
704 | * returns zero on success, negative values on failure. It is up to the caller | |
705 | * to ensure that the @sk is valid for the duration of this function. | |
706 | * | |
c6480207 | 707 | */ |
5b52330b PM |
708 | static int kauditd_send_queue(struct sock *sk, u32 portid, |
709 | struct sk_buff_head *queue, | |
710 | unsigned int retry_limit, | |
711 | void (*skb_hook)(struct sk_buff *skb), | |
712 | void (*err_hook)(struct sk_buff *skb)) | |
c6480207 | 713 | { |
5b52330b PM |
714 | int rc = 0; |
715 | struct sk_buff *skb; | |
716 | static unsigned int failed = 0; | |
32a1dbae | 717 | |
5b52330b PM |
718 | /* NOTE: kauditd_thread takes care of all our locking, we just use |
719 | * the netlink info passed to us (e.g. sk and portid) */ | |
720 | ||
721 | while ((skb = skb_dequeue(queue))) { | |
722 | /* call the skb_hook for each skb we touch */ | |
723 | if (skb_hook) | |
724 | (*skb_hook)(skb); | |
725 | ||
726 | /* can we send to anyone via unicast? */ | |
727 | if (!sk) { | |
728 | if (err_hook) | |
729 | (*err_hook)(skb); | |
730 | continue; | |
731 | } | |
6c54e789 | 732 | |
5b52330b PM |
733 | /* grab an extra skb reference in case of error */ |
734 | skb_get(skb); | |
735 | rc = netlink_unicast(sk, skb, portid, 0); | |
736 | if (rc < 0) { | |
737 | /* fatal failure for our queue flush attempt? */ | |
738 | if (++failed >= retry_limit || | |
739 | rc == -ECONNREFUSED || rc == -EPERM) { | |
740 | /* yes - error processing for the queue */ | |
741 | sk = NULL; | |
742 | if (err_hook) | |
743 | (*err_hook)(skb); | |
744 | if (!skb_hook) | |
745 | goto out; | |
746 | /* keep processing with the skb_hook */ | |
747 | continue; | |
748 | } else | |
749 | /* no - requeue to preserve ordering */ | |
750 | skb_queue_head(queue, skb); | |
751 | } else { | |
752 | /* it worked - drop the extra reference and continue */ | |
753 | consume_skb(skb); | |
754 | failed = 0; | |
755 | } | |
c6480207 PM |
756 | } |
757 | ||
5b52330b PM |
758 | out: |
759 | return (rc >= 0 ? 0 : rc); | |
f3d357b0 EP |
760 | } |
761 | ||
451f9216 | 762 | /* |
c6480207 PM |
763 | * kauditd_send_multicast_skb - Send a record to any multicast listeners |
764 | * @skb: audit record | |
451f9216 | 765 | * |
c6480207 | 766 | * Description: |
5b52330b PM |
767 | * Write a multicast message to anyone listening in the initial network |
768 | * namespace. This function doesn't consume an skb as might be expected since | |
769 | * it has to copy it anyways. | |
451f9216 | 770 | */ |
c6480207 | 771 | static void kauditd_send_multicast_skb(struct sk_buff *skb) |
451f9216 | 772 | { |
c6480207 | 773 | struct sk_buff *copy; |
5b52330b | 774 | struct sock *sock = audit_get_sk(&init_net); |
c6480207 | 775 | struct nlmsghdr *nlh; |
451f9216 | 776 | |
5b52330b PM |
777 | /* NOTE: we are not taking an additional reference for init_net since |
778 | * we don't have to worry about it going away */ | |
779 | ||
7f74ecd7 RGB |
780 | if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG)) |
781 | return; | |
782 | ||
451f9216 RGB |
783 | /* |
784 | * The seemingly wasteful skb_copy() rather than bumping the refcount | |
785 | * using skb_get() is necessary because non-standard mods are made to | |
786 | * the skb by the original kaudit unicast socket send routine. The | |
787 | * existing auditd daemon assumes this breakage. Fixing this would | |
788 | * require co-ordinating a change in the established protocol between | |
789 | * the kaudit kernel subsystem and the auditd userspace code. There is | |
790 | * no reason for new multicast clients to continue with this | |
791 | * non-compliance. | |
792 | */ | |
c6480207 | 793 | copy = skb_copy(skb, GFP_KERNEL); |
451f9216 RGB |
794 | if (!copy) |
795 | return; | |
c6480207 PM |
796 | nlh = nlmsg_hdr(copy); |
797 | nlh->nlmsg_len = skb->len; | |
451f9216 | 798 | |
c6480207 | 799 | nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL); |
451f9216 RGB |
800 | } |
801 | ||
c6480207 | 802 | /** |
5b52330b PM |
803 | * kauditd_thread - Worker thread to send audit records to userspace |
804 | * @dummy: unused | |
b551d1d9 | 805 | */ |
97a41e26 | 806 | static int kauditd_thread(void *dummy) |
b7d11258 | 807 | { |
c6480207 | 808 | int rc; |
5b52330b PM |
809 | u32 portid = 0; |
810 | struct net *net = NULL; | |
811 | struct sock *sk = NULL; | |
48d0e023 | 812 | struct auditd_connection *ac; |
4aa83872 | 813 | |
c6480207 | 814 | #define UNICAST_RETRIES 5 |
c6480207 | 815 | |
83144186 | 816 | set_freezable(); |
4899b8b1 | 817 | while (!kthread_should_stop()) { |
5b52330b PM |
818 | /* NOTE: see the lock comments in auditd_send_unicast_skb() */ |
819 | rcu_read_lock(); | |
48d0e023 PM |
820 | ac = rcu_dereference(auditd_conn); |
821 | if (!ac) { | |
5b52330b PM |
822 | rcu_read_unlock(); |
823 | goto main_queue; | |
824 | } | |
48d0e023 | 825 | net = get_net(ac->net); |
5b52330b | 826 | sk = audit_get_sk(net); |
48d0e023 | 827 | portid = ac->portid; |
5b52330b | 828 | rcu_read_unlock(); |
c6480207 PM |
829 | |
830 | /* attempt to flush the hold queue */ | |
5b52330b PM |
831 | rc = kauditd_send_queue(sk, portid, |
832 | &audit_hold_queue, UNICAST_RETRIES, | |
833 | NULL, kauditd_rehold_skb); | |
c34c78df | 834 | if (rc < 0) { |
5b52330b | 835 | sk = NULL; |
c81be52a | 836 | auditd_reset(ac); |
5b52330b | 837 | goto main_queue; |
c6480207 | 838 | } |
f3d357b0 | 839 | |
c6480207 | 840 | /* attempt to flush the retry queue */ |
5b52330b PM |
841 | rc = kauditd_send_queue(sk, portid, |
842 | &audit_retry_queue, UNICAST_RETRIES, | |
843 | NULL, kauditd_hold_skb); | |
c34c78df | 844 | if (rc < 0) { |
5b52330b | 845 | sk = NULL; |
c81be52a | 846 | auditd_reset(ac); |
5b52330b | 847 | goto main_queue; |
c6480207 | 848 | } |
db897319 | 849 | |
5b52330b PM |
850 | main_queue: |
851 | /* process the main queue - do the multicast send and attempt | |
852 | * unicast, dump failed record sends to the retry queue; if | |
853 | * sk == NULL due to previous failures we will just do the | |
c81be52a | 854 | * multicast send and move the record to the hold queue */ |
264d5096 PM |
855 | rc = kauditd_send_queue(sk, portid, &audit_queue, 1, |
856 | kauditd_send_multicast_skb, | |
c81be52a PM |
857 | (sk ? |
858 | kauditd_retry_skb : kauditd_hold_skb)); | |
859 | if (ac && rc < 0) | |
860 | auditd_reset(ac); | |
264d5096 | 861 | sk = NULL; |
5b52330b PM |
862 | |
863 | /* drop our netns reference, no auditd sends past this line */ | |
864 | if (net) { | |
865 | put_net(net); | |
866 | net = NULL; | |
3320c513 | 867 | } |
5b52330b PM |
868 | |
869 | /* we have processed all the queues so wake everyone */ | |
870 | wake_up(&audit_backlog_wait); | |
871 | ||
872 | /* NOTE: we want to wake up if there is anything on the queue, | |
873 | * regardless of if an auditd is connected, as we need to | |
874 | * do the multicast send and rotate records from the | |
875 | * main queue to the retry/hold queues */ | |
876 | wait_event_freezable(kauditd_wait, | |
877 | (skb_queue_len(&audit_queue) ? 1 : 0)); | |
b7d11258 | 878 | } |
c6480207 | 879 | |
4899b8b1 | 880 | return 0; |
b7d11258 DW |
881 | } |
882 | ||
9044e6bc AV |
883 | int audit_send_list(void *_dest) |
884 | { | |
885 | struct audit_netlink_list *dest = _dest; | |
9044e6bc | 886 | struct sk_buff *skb; |
5b52330b | 887 | struct sock *sk = audit_get_sk(dest->net); |
9044e6bc AV |
888 | |
889 | /* wait for parent to finish and send an ACK */ | |
ce423631 PM |
890 | audit_ctl_lock(); |
891 | audit_ctl_unlock(); | |
9044e6bc AV |
892 | |
893 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
5b52330b | 894 | netlink_unicast(sk, skb, dest->portid, 0); |
9044e6bc | 895 | |
5b52330b | 896 | put_net(dest->net); |
9044e6bc AV |
897 | kfree(dest); |
898 | ||
899 | return 0; | |
900 | } | |
901 | ||
45a0642b | 902 | struct sk_buff *audit_make_reply(int seq, int type, int done, |
b8800aa5 | 903 | int multi, const void *payload, int size) |
9044e6bc AV |
904 | { |
905 | struct sk_buff *skb; | |
906 | struct nlmsghdr *nlh; | |
9044e6bc AV |
907 | void *data; |
908 | int flags = multi ? NLM_F_MULTI : 0; | |
909 | int t = done ? NLMSG_DONE : type; | |
910 | ||
ee080e6c | 911 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
912 | if (!skb) |
913 | return NULL; | |
914 | ||
45a0642b | 915 | nlh = nlmsg_put(skb, 0, seq, t, size, flags); |
c64e66c6 DM |
916 | if (!nlh) |
917 | goto out_kfree_skb; | |
918 | data = nlmsg_data(nlh); | |
9044e6bc AV |
919 | memcpy(data, payload, size); |
920 | return skb; | |
921 | ||
c64e66c6 DM |
922 | out_kfree_skb: |
923 | kfree_skb(skb); | |
9044e6bc AV |
924 | return NULL; |
925 | } | |
926 | ||
a48b284b PM |
927 | static void audit_free_reply(struct audit_reply *reply) |
928 | { | |
929 | if (!reply) | |
930 | return; | |
931 | ||
932 | if (reply->skb) | |
933 | kfree_skb(reply->skb); | |
934 | if (reply->net) | |
935 | put_net(reply->net); | |
936 | kfree(reply); | |
937 | } | |
938 | ||
f09ac9db EP |
939 | static int audit_send_reply_thread(void *arg) |
940 | { | |
941 | struct audit_reply *reply = (struct audit_reply *)arg; | |
942 | ||
ce423631 PM |
943 | audit_ctl_lock(); |
944 | audit_ctl_unlock(); | |
f09ac9db EP |
945 | |
946 | /* Ignore failure. It'll only happen if the sender goes away, | |
947 | because our timeout is set to infinite. */ | |
a48b284b PM |
948 | netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0); |
949 | reply->skb = NULL; | |
950 | audit_free_reply(reply); | |
f09ac9db EP |
951 | return 0; |
952 | } | |
c6480207 | 953 | |
b0dd25a8 RD |
954 | /** |
955 | * audit_send_reply - send an audit reply message via netlink | |
d211f177 | 956 | * @request_skb: skb of request we are replying to (used to target the reply) |
b0dd25a8 RD |
957 | * @seq: sequence number |
958 | * @type: audit message type | |
959 | * @done: done (last) flag | |
960 | * @multi: multi-part message flag | |
961 | * @payload: payload data | |
962 | * @size: payload size | |
963 | * | |
a48b284b | 964 | * Allocates a skb, builds the netlink message, and sends it to the port id. |
b0dd25a8 | 965 | */ |
6f285b19 | 966 | static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done, |
f9441639 | 967 | int multi, const void *payload, int size) |
1da177e4 | 968 | { |
f09ac9db | 969 | struct task_struct *tsk; |
a48b284b | 970 | struct audit_reply *reply; |
f09ac9db | 971 | |
a48b284b | 972 | reply = kzalloc(sizeof(*reply), GFP_KERNEL); |
f09ac9db EP |
973 | if (!reply) |
974 | return; | |
975 | ||
a48b284b PM |
976 | reply->skb = audit_make_reply(seq, type, done, multi, payload, size); |
977 | if (!reply->skb) | |
978 | goto err; | |
979 | reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk)); | |
45a0642b | 980 | reply->portid = NETLINK_CB(request_skb).portid; |
f09ac9db EP |
981 | |
982 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
a48b284b PM |
983 | if (IS_ERR(tsk)) |
984 | goto err; | |
985 | ||
986 | return; | |
987 | ||
988 | err: | |
989 | audit_free_reply(reply); | |
1da177e4 LT |
990 | } |
991 | ||
992 | /* | |
993 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
994 | * control messages. | |
995 | */ | |
c7bdb545 | 996 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
997 | { |
998 | int err = 0; | |
999 | ||
5a3cb3b6 | 1000 | /* Only support initial user namespace for now. */ |
aa4af831 EP |
1001 | /* |
1002 | * We return ECONNREFUSED because it tricks userspace into thinking | |
1003 | * that audit was not configured into the kernel. Lots of users | |
1004 | * configure their PAM stack (because that's what the distro does) | |
1005 | * to reject login if unable to send messages to audit. If we return | |
1006 | * ECONNREFUSED the PAM stack thinks the kernel does not have audit | |
1007 | * configured in and will let login proceed. If we return EPERM | |
1008 | * userspace will reject all logins. This should be removed when we | |
1009 | * support non init namespaces!! | |
1010 | */ | |
0b747172 | 1011 | if (current_user_ns() != &init_user_ns) |
aa4af831 | 1012 | return -ECONNREFUSED; |
34e36d8e | 1013 | |
1da177e4 | 1014 | switch (msg_type) { |
1da177e4 | 1015 | case AUDIT_LIST: |
1da177e4 LT |
1016 | case AUDIT_ADD: |
1017 | case AUDIT_DEL: | |
18900909 EP |
1018 | return -EOPNOTSUPP; |
1019 | case AUDIT_GET: | |
1020 | case AUDIT_SET: | |
b0fed402 EP |
1021 | case AUDIT_GET_FEATURE: |
1022 | case AUDIT_SET_FEATURE: | |
18900909 EP |
1023 | case AUDIT_LIST_RULES: |
1024 | case AUDIT_ADD_RULE: | |
93315ed6 | 1025 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 1026 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
1027 | case AUDIT_TTY_GET: |
1028 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
1029 | case AUDIT_TRIM: |
1030 | case AUDIT_MAKE_EQUIV: | |
5a3cb3b6 RGB |
1031 | /* Only support auditd and auditctl in initial pid namespace |
1032 | * for now. */ | |
5985de67 | 1033 | if (task_active_pid_ns(current) != &init_pid_ns) |
5a3cb3b6 RGB |
1034 | return -EPERM; |
1035 | ||
90f62cf3 | 1036 | if (!netlink_capable(skb, CAP_AUDIT_CONTROL)) |
1da177e4 LT |
1037 | err = -EPERM; |
1038 | break; | |
05474106 | 1039 | case AUDIT_USER: |
039b6b3e RD |
1040 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
1041 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
90f62cf3 | 1042 | if (!netlink_capable(skb, CAP_AUDIT_WRITE)) |
1da177e4 LT |
1043 | err = -EPERM; |
1044 | break; | |
1045 | default: /* bad msg */ | |
1046 | err = -EINVAL; | |
1047 | } | |
1048 | ||
1049 | return err; | |
1050 | } | |
1051 | ||
626abcd1 RGB |
1052 | static void audit_log_common_recv_msg(struct audit_context *context, |
1053 | struct audit_buffer **ab, u16 msg_type) | |
50397bd1 | 1054 | { |
dc9eb698 | 1055 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
f1dc4867 | 1056 | pid_t pid = task_tgid_nr(current); |
50397bd1 | 1057 | |
0868a5e1 | 1058 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 | 1059 | *ab = NULL; |
233a6866 | 1060 | return; |
50397bd1 EP |
1061 | } |
1062 | ||
626abcd1 | 1063 | *ab = audit_log_start(context, GFP_KERNEL, msg_type); |
0644ec0c | 1064 | if (unlikely(!*ab)) |
233a6866 | 1065 | return; |
a2c97da1 | 1066 | audit_log_format(*ab, "pid=%d uid=%u ", pid, uid); |
4d3fb709 | 1067 | audit_log_session_info(*ab); |
b122c376 | 1068 | audit_log_task_context(*ab); |
50397bd1 EP |
1069 | } |
1070 | ||
626abcd1 RGB |
1071 | static inline void audit_log_user_recv_msg(struct audit_buffer **ab, |
1072 | u16 msg_type) | |
1073 | { | |
1074 | audit_log_common_recv_msg(NULL, ab, msg_type); | |
1075 | } | |
1076 | ||
b0fed402 EP |
1077 | int is_audit_feature_set(int i) |
1078 | { | |
1079 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
1080 | } | |
1081 | ||
1082 | ||
1083 | static int audit_get_feature(struct sk_buff *skb) | |
1084 | { | |
1085 | u32 seq; | |
1086 | ||
1087 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
1088 | ||
9ef91514 | 1089 | audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af)); |
b0fed402 EP |
1090 | |
1091 | return 0; | |
1092 | } | |
1093 | ||
1094 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
1095 | u32 old_lock, u32 new_lock, int res) | |
1096 | { | |
1097 | struct audit_buffer *ab; | |
1098 | ||
b6c50fe0 G |
1099 | if (audit_enabled == AUDIT_OFF) |
1100 | return; | |
2a1fe215 | 1101 | |
cdfb6b34 | 1102 | ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_FEATURE_CHANGE); |
23138ead RGB |
1103 | if (!ab) |
1104 | return; | |
2a1fe215 | 1105 | audit_log_task_info(ab); |
897f1acb | 1106 | audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d", |
b0fed402 EP |
1107 | audit_feature_names[which], !!old_feature, !!new_feature, |
1108 | !!old_lock, !!new_lock, res); | |
1109 | audit_log_end(ab); | |
1110 | } | |
1111 | ||
75612528 | 1112 | static int audit_set_feature(struct audit_features *uaf) |
b0fed402 | 1113 | { |
b0fed402 EP |
1114 | int i; |
1115 | ||
6eed9b26 | 1116 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names)); |
b0fed402 EP |
1117 | |
1118 | /* if there is ever a version 2 we should handle that here */ | |
1119 | ||
1120 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
1121 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
1122 | u32 old_feature, new_feature, old_lock, new_lock; | |
1123 | ||
1124 | /* if we are not changing this feature, move along */ | |
1125 | if (!(feature & uaf->mask)) | |
1126 | continue; | |
1127 | ||
1128 | old_feature = af.features & feature; | |
1129 | new_feature = uaf->features & feature; | |
1130 | new_lock = (uaf->lock | af.lock) & feature; | |
1131 | old_lock = af.lock & feature; | |
1132 | ||
1133 | /* are we changing a locked feature? */ | |
4547b3bc | 1134 | if (old_lock && (new_feature != old_feature)) { |
b0fed402 EP |
1135 | audit_log_feature_change(i, old_feature, new_feature, |
1136 | old_lock, new_lock, 0); | |
1137 | return -EPERM; | |
1138 | } | |
1139 | } | |
1140 | /* nothing invalid, do the changes */ | |
1141 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
1142 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
1143 | u32 old_feature, new_feature, old_lock, new_lock; | |
1144 | ||
1145 | /* if we are not changing this feature, move along */ | |
1146 | if (!(feature & uaf->mask)) | |
1147 | continue; | |
1148 | ||
1149 | old_feature = af.features & feature; | |
1150 | new_feature = uaf->features & feature; | |
1151 | old_lock = af.lock & feature; | |
1152 | new_lock = (uaf->lock | af.lock) & feature; | |
1153 | ||
1154 | if (new_feature != old_feature) | |
1155 | audit_log_feature_change(i, old_feature, new_feature, | |
1156 | old_lock, new_lock, 1); | |
1157 | ||
1158 | if (new_feature) | |
1159 | af.features |= feature; | |
1160 | else | |
1161 | af.features &= ~feature; | |
1162 | af.lock |= new_lock; | |
1163 | } | |
1164 | ||
1165 | return 0; | |
1166 | } | |
1167 | ||
b6c7c115 | 1168 | static int audit_replace(struct pid *pid) |
133e1e5a | 1169 | { |
b6c7c115 | 1170 | pid_t pvnr; |
5b52330b | 1171 | struct sk_buff *skb; |
133e1e5a | 1172 | |
b6c7c115 PM |
1173 | pvnr = pid_vnr(pid); |
1174 | skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr)); | |
133e1e5a RGB |
1175 | if (!skb) |
1176 | return -ENOMEM; | |
5b52330b | 1177 | return auditd_send_unicast_skb(skb); |
133e1e5a RGB |
1178 | } |
1179 | ||
1da177e4 LT |
1180 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
1181 | { | |
dc9eb698 | 1182 | u32 seq; |
1da177e4 | 1183 | void *data; |
75612528 | 1184 | int data_len; |
1da177e4 | 1185 | int err; |
c0404993 | 1186 | struct audit_buffer *ab; |
1da177e4 | 1187 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 1188 | struct audit_sig_info *sig_data; |
50397bd1 | 1189 | char *ctx = NULL; |
e1396065 | 1190 | u32 len; |
1da177e4 | 1191 | |
c7bdb545 | 1192 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
1193 | if (err) |
1194 | return err; | |
1195 | ||
1da177e4 | 1196 | seq = nlh->nlmsg_seq; |
c64e66c6 | 1197 | data = nlmsg_data(nlh); |
75612528 | 1198 | data_len = nlmsg_len(nlh); |
1da177e4 LT |
1199 | |
1200 | switch (msg_type) { | |
09f883a9 RGB |
1201 | case AUDIT_GET: { |
1202 | struct audit_status s; | |
1203 | memset(&s, 0, sizeof(s)); | |
1204 | s.enabled = audit_enabled; | |
1205 | s.failure = audit_failure; | |
b6c7c115 PM |
1206 | /* NOTE: use pid_vnr() so the PID is relative to the current |
1207 | * namespace */ | |
48d0e023 | 1208 | s.pid = auditd_pid_vnr(); |
09f883a9 RGB |
1209 | s.rate_limit = audit_rate_limit; |
1210 | s.backlog_limit = audit_backlog_limit; | |
1211 | s.lost = atomic_read(&audit_lost); | |
af8b824f | 1212 | s.backlog = skb_queue_len(&audit_queue); |
0288d718 | 1213 | s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL; |
31975424 | 1214 | s.backlog_wait_time = audit_backlog_wait_time; |
6f285b19 | 1215 | audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s)); |
1da177e4 | 1216 | break; |
09f883a9 RGB |
1217 | } |
1218 | case AUDIT_SET: { | |
1219 | struct audit_status s; | |
1220 | memset(&s, 0, sizeof(s)); | |
1221 | /* guard against past and future API changes */ | |
75612528 | 1222 | memcpy(&s, data, min_t(size_t, sizeof(s), data_len)); |
09f883a9 RGB |
1223 | if (s.mask & AUDIT_STATUS_ENABLED) { |
1224 | err = audit_set_enabled(s.enabled); | |
20c6aaa3 | 1225 | if (err < 0) |
1226 | return err; | |
1da177e4 | 1227 | } |
09f883a9 RGB |
1228 | if (s.mask & AUDIT_STATUS_FAILURE) { |
1229 | err = audit_set_failure(s.failure); | |
20c6aaa3 | 1230 | if (err < 0) |
1231 | return err; | |
1da177e4 | 1232 | } |
09f883a9 | 1233 | if (s.mask & AUDIT_STATUS_PID) { |
b6c7c115 PM |
1234 | /* NOTE: we are using the vnr PID functions below |
1235 | * because the s.pid value is relative to the | |
1236 | * namespace of the caller; at present this | |
1237 | * doesn't matter much since you can really only | |
1238 | * run auditd from the initial pid namespace, but | |
1239 | * something to keep in mind if this changes */ | |
1240 | pid_t new_pid = s.pid; | |
5b52330b | 1241 | pid_t auditd_pid; |
b6c7c115 PM |
1242 | struct pid *req_pid = task_tgid(current); |
1243 | ||
33e8a907 SG |
1244 | /* Sanity check - PID values must match. Setting |
1245 | * pid to 0 is how auditd ends auditing. */ | |
1246 | if (new_pid && (new_pid != pid_vnr(req_pid))) | |
b6c7c115 | 1247 | return -EINVAL; |
1a6b9f23 | 1248 | |
5b52330b | 1249 | /* test the auditd connection */ |
b6c7c115 | 1250 | audit_replace(req_pid); |
5b52330b | 1251 | |
48d0e023 | 1252 | auditd_pid = auditd_pid_vnr(); |
33e8a907 SG |
1253 | if (auditd_pid) { |
1254 | /* replacing a healthy auditd is not allowed */ | |
1255 | if (new_pid) { | |
1256 | audit_log_config_change("audit_pid", | |
1257 | new_pid, auditd_pid, 0); | |
1258 | return -EEXIST; | |
1259 | } | |
1260 | /* only current auditd can unregister itself */ | |
1261 | if (pid_vnr(req_pid) != auditd_pid) { | |
1262 | audit_log_config_change("audit_pid", | |
1263 | new_pid, auditd_pid, 0); | |
1264 | return -EACCES; | |
1265 | } | |
935c9e7f | 1266 | } |
5b52330b | 1267 | |
533c7b69 | 1268 | if (new_pid) { |
5b52330b | 1269 | /* register a new auditd connection */ |
48d0e023 PM |
1270 | err = auditd_set(req_pid, |
1271 | NETLINK_CB(skb).portid, | |
1272 | sock_net(NETLINK_CB(skb).sk)); | |
1273 | if (audit_enabled != AUDIT_OFF) | |
1274 | audit_log_config_change("audit_pid", | |
1275 | new_pid, | |
1276 | auditd_pid, | |
1277 | err ? 0 : 1); | |
1278 | if (err) | |
1279 | return err; | |
1280 | ||
5b52330b PM |
1281 | /* try to process any backlog */ |
1282 | wake_up_interruptible(&kauditd_wait); | |
48d0e023 PM |
1283 | } else { |
1284 | if (audit_enabled != AUDIT_OFF) | |
1285 | audit_log_config_change("audit_pid", | |
1286 | new_pid, | |
1287 | auditd_pid, 1); | |
1288 | ||
5b52330b | 1289 | /* unregister the auditd connection */ |
c81be52a | 1290 | auditd_reset(NULL); |
48d0e023 | 1291 | } |
1da177e4 | 1292 | } |
09f883a9 RGB |
1293 | if (s.mask & AUDIT_STATUS_RATE_LIMIT) { |
1294 | err = audit_set_rate_limit(s.rate_limit); | |
20c6aaa3 | 1295 | if (err < 0) |
1296 | return err; | |
1297 | } | |
51cc83f0 | 1298 | if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) { |
09f883a9 | 1299 | err = audit_set_backlog_limit(s.backlog_limit); |
51cc83f0 RGB |
1300 | if (err < 0) |
1301 | return err; | |
1302 | } | |
3f0c5fad EP |
1303 | if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) { |
1304 | if (sizeof(s) > (size_t)nlh->nlmsg_len) | |
1305 | return -EINVAL; | |
724e7bfc | 1306 | if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME) |
3f0c5fad EP |
1307 | return -EINVAL; |
1308 | err = audit_set_backlog_wait_time(s.backlog_wait_time); | |
1309 | if (err < 0) | |
1310 | return err; | |
51cc83f0 | 1311 | } |
92c82e8a RGB |
1312 | if (s.mask == AUDIT_STATUS_LOST) { |
1313 | u32 lost = atomic_xchg(&audit_lost, 0); | |
1314 | ||
1315 | audit_log_config_change("lost", 0, lost, 1); | |
1316 | return lost; | |
1317 | } | |
1da177e4 | 1318 | break; |
09f883a9 | 1319 | } |
b0fed402 EP |
1320 | case AUDIT_GET_FEATURE: |
1321 | err = audit_get_feature(skb); | |
1322 | if (err) | |
1323 | return err; | |
1324 | break; | |
1325 | case AUDIT_SET_FEATURE: | |
75612528 PM |
1326 | if (data_len < sizeof(struct audit_features)) |
1327 | return -EINVAL; | |
1328 | err = audit_set_feature(data); | |
b0fed402 EP |
1329 | if (err) |
1330 | return err; | |
1331 | break; | |
05474106 | 1332 | case AUDIT_USER: |
039b6b3e RD |
1333 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
1334 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
1335 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
1336 | return 0; | |
1337 | ||
86b2efbe | 1338 | err = audit_filter(msg_type, AUDIT_FILTER_USER); |
724e4fcc | 1339 | if (err == 1) { /* match or error */ |
75612528 PM |
1340 | char *str = data; |
1341 | ||
4a4cd633 | 1342 | err = 0; |
522ed776 | 1343 | if (msg_type == AUDIT_USER_TTY) { |
37282a77 | 1344 | err = tty_audit_push(); |
522ed776 MT |
1345 | if (err) |
1346 | break; | |
1347 | } | |
626abcd1 | 1348 | audit_log_user_recv_msg(&ab, msg_type); |
75612528 PM |
1349 | if (msg_type != AUDIT_USER_TTY) { |
1350 | /* ensure NULL termination */ | |
1351 | str[data_len - 1] = '\0'; | |
b50eba7e RGB |
1352 | audit_log_format(ab, " msg='%.*s'", |
1353 | AUDIT_MESSAGE_TEXT_MAX, | |
75612528 PM |
1354 | str); |
1355 | } else { | |
f7616102 | 1356 | audit_log_format(ab, " data="); |
75612528 PM |
1357 | if (data_len > 0 && str[data_len - 1] == '\0') |
1358 | data_len--; | |
1359 | audit_log_n_untrustedstring(ab, str, data_len); | |
4a4cd633 | 1360 | } |
50397bd1 | 1361 | audit_log_end(ab); |
0f45aa18 | 1362 | } |
1da177e4 | 1363 | break; |
93315ed6 AG |
1364 | case AUDIT_ADD_RULE: |
1365 | case AUDIT_DEL_RULE: | |
75612528 | 1366 | if (data_len < sizeof(struct audit_rule_data)) |
93315ed6 | 1367 | return -EINVAL; |
1a6b9f23 | 1368 | if (audit_enabled == AUDIT_LOCKED) { |
626abcd1 RGB |
1369 | audit_log_common_recv_msg(audit_context(), &ab, |
1370 | AUDIT_CONFIG_CHANGE); | |
53fc7a01 RGB |
1371 | audit_log_format(ab, " op=%s audit_enabled=%d res=0", |
1372 | msg_type == AUDIT_ADD_RULE ? | |
1373 | "add_rule" : "remove_rule", | |
1374 | audit_enabled); | |
50397bd1 | 1375 | audit_log_end(ab); |
6a01b07f SG |
1376 | return -EPERM; |
1377 | } | |
75612528 | 1378 | err = audit_rule_change(msg_type, seq, data, data_len); |
1da177e4 | 1379 | break; |
ce0d9f04 | 1380 | case AUDIT_LIST_RULES: |
6f285b19 | 1381 | err = audit_list_rules_send(skb, seq); |
ce0d9f04 | 1382 | break; |
74c3cbe3 AV |
1383 | case AUDIT_TRIM: |
1384 | audit_trim_trees(); | |
626abcd1 RGB |
1385 | audit_log_common_recv_msg(audit_context(), &ab, |
1386 | AUDIT_CONFIG_CHANGE); | |
74c3cbe3 AV |
1387 | audit_log_format(ab, " op=trim res=1"); |
1388 | audit_log_end(ab); | |
1389 | break; | |
1390 | case AUDIT_MAKE_EQUIV: { | |
1391 | void *bufp = data; | |
1392 | u32 sizes[2]; | |
75612528 | 1393 | size_t msglen = data_len; |
74c3cbe3 AV |
1394 | char *old, *new; |
1395 | ||
1396 | err = -EINVAL; | |
7719e437 | 1397 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
1398 | break; |
1399 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
1400 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
1401 | msglen -= 2 * sizeof(u32); |
1402 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
1403 | if (IS_ERR(old)) { |
1404 | err = PTR_ERR(old); | |
1405 | break; | |
1406 | } | |
7719e437 | 1407 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
1408 | if (IS_ERR(new)) { |
1409 | err = PTR_ERR(new); | |
1410 | kfree(old); | |
1411 | break; | |
1412 | } | |
1413 | /* OK, here comes... */ | |
1414 | err = audit_tag_tree(old, new); | |
1415 | ||
626abcd1 RGB |
1416 | audit_log_common_recv_msg(audit_context(), &ab, |
1417 | AUDIT_CONFIG_CHANGE); | |
74c3cbe3 AV |
1418 | audit_log_format(ab, " op=make_equiv old="); |
1419 | audit_log_untrustedstring(ab, old); | |
1420 | audit_log_format(ab, " new="); | |
1421 | audit_log_untrustedstring(ab, new); | |
1422 | audit_log_format(ab, " res=%d", !err); | |
1423 | audit_log_end(ab); | |
1424 | kfree(old); | |
1425 | kfree(new); | |
1426 | break; | |
1427 | } | |
c2f0c7c3 | 1428 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
1429 | len = 0; |
1430 | if (audit_sig_sid) { | |
1431 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
1432 | if (err) | |
1433 | return err; | |
1434 | } | |
e1396065 AV |
1435 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
1436 | if (!sig_data) { | |
939cbf26 EP |
1437 | if (audit_sig_sid) |
1438 | security_release_secctx(ctx, len); | |
e1396065 AV |
1439 | return -ENOMEM; |
1440 | } | |
cca080d9 | 1441 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 1442 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
1443 | if (audit_sig_sid) { |
1444 | memcpy(sig_data->ctx, ctx, len); | |
1445 | security_release_secctx(ctx, len); | |
1446 | } | |
6f285b19 EB |
1447 | audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, |
1448 | sig_data, sizeof(*sig_data) + len); | |
e1396065 | 1449 | kfree(sig_data); |
c2f0c7c3 | 1450 | break; |
522ed776 MT |
1451 | case AUDIT_TTY_GET: { |
1452 | struct audit_tty_status s; | |
2e28d38a | 1453 | unsigned int t; |
8aa14b64 | 1454 | |
2e28d38a PH |
1455 | t = READ_ONCE(current->signal->audit_tty); |
1456 | s.enabled = t & AUDIT_TTY_ENABLE; | |
1457 | s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD); | |
8aa14b64 | 1458 | |
6f285b19 | 1459 | audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
1460 | break; |
1461 | } | |
1462 | case AUDIT_TTY_SET: { | |
a06e56b2 | 1463 | struct audit_tty_status s, old; |
a06e56b2 | 1464 | struct audit_buffer *ab; |
2e28d38a | 1465 | unsigned int t; |
0e23bacc EP |
1466 | |
1467 | memset(&s, 0, sizeof(s)); | |
1468 | /* guard against past and future API changes */ | |
75612528 | 1469 | memcpy(&s, data, min_t(size_t, sizeof(s), data_len)); |
0e23bacc EP |
1470 | /* check if new data is valid */ |
1471 | if ((s.enabled != 0 && s.enabled != 1) || | |
1472 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
1473 | err = -EINVAL; | |
a06e56b2 | 1474 | |
2e28d38a PH |
1475 | if (err) |
1476 | t = READ_ONCE(current->signal->audit_tty); | |
1477 | else { | |
1478 | t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD); | |
1479 | t = xchg(¤t->signal->audit_tty, t); | |
0e23bacc | 1480 | } |
2e28d38a PH |
1481 | old.enabled = t & AUDIT_TTY_ENABLE; |
1482 | old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD); | |
522ed776 | 1483 | |
626abcd1 RGB |
1484 | audit_log_common_recv_msg(audit_context(), &ab, |
1485 | AUDIT_CONFIG_CHANGE); | |
1ce319f1 EP |
1486 | audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d" |
1487 | " old-log_passwd=%d new-log_passwd=%d res=%d", | |
1488 | old.enabled, s.enabled, old.log_passwd, | |
1489 | s.log_passwd, !err); | |
a06e56b2 | 1490 | audit_log_end(ab); |
522ed776 MT |
1491 | break; |
1492 | } | |
1da177e4 LT |
1493 | default: |
1494 | err = -EINVAL; | |
1495 | break; | |
1496 | } | |
1497 | ||
1498 | return err < 0 ? err : 0; | |
1499 | } | |
1500 | ||
a9d16208 PM |
1501 | /** |
1502 | * audit_receive - receive messages from a netlink control socket | |
1503 | * @skb: the message buffer | |
1504 | * | |
1505 | * Parse the provided skb and deal with any messages that may be present, | |
1506 | * malformed skbs are discarded. | |
b0dd25a8 | 1507 | */ |
a9d16208 | 1508 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 1509 | { |
ea7ae60b EP |
1510 | struct nlmsghdr *nlh; |
1511 | /* | |
94191213 | 1512 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
1513 | * if the nlmsg_len was not aligned |
1514 | */ | |
1515 | int len; | |
1516 | int err; | |
1517 | ||
1518 | nlh = nlmsg_hdr(skb); | |
1519 | len = skb->len; | |
1520 | ||
ce423631 | 1521 | audit_ctl_lock(); |
94191213 | 1522 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
1523 | err = audit_receive_msg(skb, nlh); |
1524 | /* if err or if this message says it wants a response */ | |
1525 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
2d4bc933 | 1526 | netlink_ack(skb, nlh, err, NULL); |
ea7ae60b | 1527 | |
2851da57 | 1528 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 1529 | } |
ce423631 | 1530 | audit_ctl_unlock(); |
1da177e4 LT |
1531 | } |
1532 | ||
3a101b8d | 1533 | /* Run custom bind function on netlink socket group connect or bind requests. */ |
023e2cfa | 1534 | static int audit_bind(struct net *net, int group) |
3a101b8d RGB |
1535 | { |
1536 | if (!capable(CAP_AUDIT_READ)) | |
1537 | return -EPERM; | |
1538 | ||
1539 | return 0; | |
1540 | } | |
1541 | ||
33faba7f | 1542 | static int __net_init audit_net_init(struct net *net) |
1da177e4 | 1543 | { |
a31f2d17 PNA |
1544 | struct netlink_kernel_cfg cfg = { |
1545 | .input = audit_receive, | |
3a101b8d | 1546 | .bind = audit_bind, |
451f9216 RGB |
1547 | .flags = NL_CFG_F_NONROOT_RECV, |
1548 | .groups = AUDIT_NLGRP_MAX, | |
a31f2d17 | 1549 | }; |
f368c07d | 1550 | |
33faba7f RGB |
1551 | struct audit_net *aunet = net_generic(net, audit_net_id); |
1552 | ||
5b52330b PM |
1553 | aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); |
1554 | if (aunet->sk == NULL) { | |
33faba7f | 1555 | audit_panic("cannot initialize netlink socket in namespace"); |
11ee39eb G |
1556 | return -ENOMEM; |
1557 | } | |
5b52330b PM |
1558 | aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; |
1559 | ||
33faba7f RGB |
1560 | return 0; |
1561 | } | |
1562 | ||
1563 | static void __net_exit audit_net_exit(struct net *net) | |
1564 | { | |
1565 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
5b52330b | 1566 | |
48d0e023 PM |
1567 | /* NOTE: you would think that we would want to check the auditd |
1568 | * connection and potentially reset it here if it lives in this | |
1569 | * namespace, but since the auditd connection tracking struct holds a | |
1570 | * reference to this namespace (see auditd_set()) we are only ever | |
1571 | * going to get here after that connection has been released */ | |
33faba7f | 1572 | |
5b52330b | 1573 | netlink_kernel_release(aunet->sk); |
33faba7f RGB |
1574 | } |
1575 | ||
8626877b | 1576 | static struct pernet_operations audit_net_ops __net_initdata = { |
33faba7f RGB |
1577 | .init = audit_net_init, |
1578 | .exit = audit_net_exit, | |
1579 | .id = &audit_net_id, | |
1580 | .size = sizeof(struct audit_net), | |
1581 | }; | |
1582 | ||
1583 | /* Initialize audit support at boot time. */ | |
1584 | static int __init audit_init(void) | |
1585 | { | |
1586 | int i; | |
1587 | ||
a3f07114 EP |
1588 | if (audit_initialized == AUDIT_DISABLED) |
1589 | return 0; | |
1590 | ||
8cc96382 PM |
1591 | audit_buffer_cache = kmem_cache_create("audit_buffer", |
1592 | sizeof(struct audit_buffer), | |
1593 | 0, SLAB_PANIC, NULL); | |
1da177e4 | 1594 | |
af8b824f | 1595 | skb_queue_head_init(&audit_queue); |
c6480207 | 1596 | skb_queue_head_init(&audit_retry_queue); |
af8b824f | 1597 | skb_queue_head_init(&audit_hold_queue); |
3dc7e315 | 1598 | |
f368c07d AG |
1599 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1600 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1601 | |
ce423631 PM |
1602 | mutex_init(&audit_cmd_mutex.lock); |
1603 | audit_cmd_mutex.owner = NULL; | |
1604 | ||
5b52330b PM |
1605 | pr_info("initializing netlink subsys (%s)\n", |
1606 | audit_default ? "enabled" : "disabled"); | |
1607 | register_pernet_subsys(&audit_net_ops); | |
1608 | ||
1609 | audit_initialized = AUDIT_INITIALIZED; | |
5b52330b | 1610 | |
6c925564 PM |
1611 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
1612 | if (IS_ERR(kauditd_task)) { | |
1613 | int err = PTR_ERR(kauditd_task); | |
1614 | panic("audit: failed to start the kauditd thread (%d)\n", err); | |
1615 | } | |
1616 | ||
7c397d01 SG |
1617 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, |
1618 | "state=initialized audit_enabled=%u res=1", | |
1619 | audit_enabled); | |
6c925564 | 1620 | |
1da177e4 LT |
1621 | return 0; |
1622 | } | |
be4104ab | 1623 | postcore_initcall(audit_init); |
1da177e4 | 1624 | |
11dd2666 GE |
1625 | /* |
1626 | * Process kernel command-line parameter at boot time. | |
1627 | * audit={0|off} or audit={1|on}. | |
1628 | */ | |
1da177e4 LT |
1629 | static int __init audit_enable(char *str) |
1630 | { | |
11dd2666 GE |
1631 | if (!strcasecmp(str, "off") || !strcmp(str, "0")) |
1632 | audit_default = AUDIT_OFF; | |
1633 | else if (!strcasecmp(str, "on") || !strcmp(str, "1")) | |
1634 | audit_default = AUDIT_ON; | |
1635 | else { | |
1636 | pr_err("audit: invalid 'audit' parameter value (%s)\n", str); | |
1637 | audit_default = AUDIT_ON; | |
1638 | } | |
80ab4df6 PM |
1639 | |
1640 | if (audit_default == AUDIT_OFF) | |
a3f07114 | 1641 | audit_initialized = AUDIT_DISABLED; |
5d842a5b | 1642 | if (audit_set_enabled(audit_default)) |
11dd2666 GE |
1643 | pr_err("audit: error setting audit state (%d)\n", |
1644 | audit_default); | |
a3f07114 | 1645 | |
d957f7b7 | 1646 | pr_info("%s\n", audit_default ? |
d3ca0344 | 1647 | "enabled (after initialization)" : "disabled (until reboot)"); |
a3f07114 | 1648 | |
9b41046c | 1649 | return 1; |
1da177e4 | 1650 | } |
1da177e4 LT |
1651 | __setup("audit=", audit_enable); |
1652 | ||
f910fde7 RGB |
1653 | /* Process kernel command-line parameter at boot time. |
1654 | * audit_backlog_limit=<n> */ | |
1655 | static int __init audit_backlog_limit_set(char *str) | |
1656 | { | |
3e1d0bb6 | 1657 | u32 audit_backlog_limit_arg; |
d957f7b7 | 1658 | |
f910fde7 | 1659 | pr_info("audit_backlog_limit: "); |
3e1d0bb6 JP |
1660 | if (kstrtouint(str, 0, &audit_backlog_limit_arg)) { |
1661 | pr_cont("using default of %u, unable to parse %s\n", | |
d957f7b7 | 1662 | audit_backlog_limit, str); |
f910fde7 RGB |
1663 | return 1; |
1664 | } | |
3e1d0bb6 JP |
1665 | |
1666 | audit_backlog_limit = audit_backlog_limit_arg; | |
d957f7b7 | 1667 | pr_cont("%d\n", audit_backlog_limit); |
f910fde7 RGB |
1668 | |
1669 | return 1; | |
1670 | } | |
1671 | __setup("audit_backlog_limit=", audit_backlog_limit_set); | |
1672 | ||
16e1904e CW |
1673 | static void audit_buffer_free(struct audit_buffer *ab) |
1674 | { | |
8fc6115c CW |
1675 | if (!ab) |
1676 | return; | |
1677 | ||
d865e573 | 1678 | kfree_skb(ab->skb); |
8cc96382 | 1679 | kmem_cache_free(audit_buffer_cache, ab); |
16e1904e CW |
1680 | } |
1681 | ||
8cc96382 PM |
1682 | static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx, |
1683 | gfp_t gfp_mask, int type) | |
16e1904e | 1684 | { |
8cc96382 | 1685 | struct audit_buffer *ab; |
8fc6115c | 1686 | |
8cc96382 PM |
1687 | ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask); |
1688 | if (!ab) | |
1689 | return NULL; | |
ee080e6c EP |
1690 | |
1691 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1692 | if (!ab->skb) | |
c64e66c6 | 1693 | goto err; |
8cc96382 PM |
1694 | if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0)) |
1695 | goto err; | |
ee080e6c | 1696 | |
8cc96382 PM |
1697 | ab->ctx = ctx; |
1698 | ab->gfp_mask = gfp_mask; | |
ee080e6c | 1699 | |
16e1904e | 1700 | return ab; |
ee080e6c | 1701 | |
8fc6115c CW |
1702 | err: |
1703 | audit_buffer_free(ab); | |
1704 | return NULL; | |
16e1904e | 1705 | } |
1da177e4 | 1706 | |
b0dd25a8 RD |
1707 | /** |
1708 | * audit_serial - compute a serial number for the audit record | |
1709 | * | |
1710 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1711 | * written to user-space as soon as they are generated, so a complete |
1712 | * audit record may be written in several pieces. The timestamp of the | |
1713 | * record and this serial number are used by the user-space tools to | |
1714 | * determine which pieces belong to the same audit record. The | |
1715 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1716 | * syscall entry to syscall exit. | |
1717 | * | |
bfb4496e DW |
1718 | * NOTE: Another possibility is to store the formatted records off the |
1719 | * audit context (for those records that have a context), and emit them | |
1720 | * all at syscall exit. However, this could delay the reporting of | |
1721 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1722 | * halts). |
1723 | */ | |
bfb4496e DW |
1724 | unsigned int audit_serial(void) |
1725 | { | |
01478d7d | 1726 | static atomic_t serial = ATOMIC_INIT(0); |
d5b454f2 | 1727 | |
01478d7d | 1728 | return atomic_add_return(1, &serial); |
bfb4496e DW |
1729 | } |
1730 | ||
5600b892 | 1731 | static inline void audit_get_stamp(struct audit_context *ctx, |
2115bb25 | 1732 | struct timespec64 *t, unsigned int *serial) |
bfb4496e | 1733 | { |
48887e63 | 1734 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
290e44b7 | 1735 | ktime_get_coarse_real_ts64(t); |
bfb4496e DW |
1736 | *serial = audit_serial(); |
1737 | } | |
1738 | } | |
1739 | ||
b0dd25a8 RD |
1740 | /** |
1741 | * audit_log_start - obtain an audit buffer | |
1742 | * @ctx: audit_context (may be NULL) | |
1743 | * @gfp_mask: type of allocation | |
1744 | * @type: audit message type | |
1745 | * | |
1746 | * Returns audit_buffer pointer on success or NULL on error. | |
1747 | * | |
1748 | * Obtain an audit buffer. This routine does locking to obtain the | |
1749 | * audit buffer, but then no locking is required for calls to | |
1750 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1751 | * syscall, then the syscall is marked as auditable and an audit record | |
1752 | * will be written at syscall exit. If there is no associated task, then | |
1753 | * task context (ctx) should be NULL. | |
1754 | */ | |
9796fdd8 | 1755 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1756 | int type) |
1da177e4 | 1757 | { |
31975424 | 1758 | struct audit_buffer *ab; |
2115bb25 | 1759 | struct timespec64 t; |
31975424 | 1760 | unsigned int uninitialized_var(serial); |
1da177e4 | 1761 | |
a3f07114 | 1762 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1763 | return NULL; |
1764 | ||
d904ac03 | 1765 | if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCLUDE))) |
c8edc80c DK |
1766 | return NULL; |
1767 | ||
5b52330b | 1768 | /* NOTE: don't ever fail/sleep on these two conditions: |
a09cfa47 PM |
1769 | * 1. auditd generated record - since we need auditd to drain the |
1770 | * queue; also, when we are checking for auditd, compare PIDs using | |
1771 | * task_tgid_vnr() since auditd_pid is set in audit_receive_msg() | |
1772 | * using a PID anchored in the caller's namespace | |
5b52330b PM |
1773 | * 2. generator holding the audit_cmd_mutex - we don't want to block |
1774 | * while holding the mutex */ | |
ce423631 | 1775 | if (!(auditd_test_task(current) || audit_ctl_owner_current())) { |
5b52330b | 1776 | long stime = audit_backlog_wait_time; |
31975424 PM |
1777 | |
1778 | while (audit_backlog_limit && | |
1779 | (skb_queue_len(&audit_queue) > audit_backlog_limit)) { | |
1780 | /* wake kauditd to try and flush the queue */ | |
1781 | wake_up_interruptible(&kauditd_wait); | |
9ad9ad38 | 1782 | |
31975424 PM |
1783 | /* sleep if we are allowed and we haven't exhausted our |
1784 | * backlog wait limit */ | |
5b52330b | 1785 | if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) { |
31975424 PM |
1786 | DECLARE_WAITQUEUE(wait, current); |
1787 | ||
1788 | add_wait_queue_exclusive(&audit_backlog_wait, | |
1789 | &wait); | |
1790 | set_current_state(TASK_UNINTERRUPTIBLE); | |
5b52330b | 1791 | stime = schedule_timeout(stime); |
31975424 PM |
1792 | remove_wait_queue(&audit_backlog_wait, &wait); |
1793 | } else { | |
1794 | if (audit_rate_check() && printk_ratelimit()) | |
1795 | pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n", | |
1796 | skb_queue_len(&audit_queue), | |
1797 | audit_backlog_limit); | |
1798 | audit_log_lost("backlog limit exceeded"); | |
1799 | return NULL; | |
8ac1c8d5 | 1800 | } |
9ad9ad38 | 1801 | } |
fb19b4c6 DW |
1802 | } |
1803 | ||
9ad9ad38 | 1804 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1805 | if (!ab) { |
1806 | audit_log_lost("out of memory in audit_log_start"); | |
1807 | return NULL; | |
1808 | } | |
1809 | ||
bfb4496e | 1810 | audit_get_stamp(ab->ctx, &t, &serial); |
1320a405 | 1811 | audit_clear_dummy(ab->ctx); |
2115bb25 DD |
1812 | audit_log_format(ab, "audit(%llu.%03lu:%u): ", |
1813 | (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial); | |
31975424 | 1814 | |
1da177e4 LT |
1815 | return ab; |
1816 | } | |
1817 | ||
8fc6115c | 1818 | /** |
5ac52f33 | 1819 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1820 | * @ab: audit_buffer |
b0dd25a8 | 1821 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1822 | * |
1823 | * Returns 0 (no space) on failed expansion, or available space if | |
1824 | * successful. | |
1825 | */ | |
e3b926b4 | 1826 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1827 | { |
5ac52f33 | 1828 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1829 | int oldtail = skb_tailroom(skb); |
1830 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1831 | int newtail = skb_tailroom(skb); | |
1832 | ||
5ac52f33 CW |
1833 | if (ret < 0) { |
1834 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1835 | return 0; |
5ac52f33 | 1836 | } |
406a1d86 HX |
1837 | |
1838 | skb->truesize += newtail - oldtail; | |
1839 | return newtail; | |
8fc6115c | 1840 | } |
1da177e4 | 1841 | |
b0dd25a8 RD |
1842 | /* |
1843 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1844 | * room in the audit buffer, more room will be allocated and vsnprint |
1845 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1846 | * can't format message larger than 1024 bytes, so we don't either. |
1847 | */ | |
1da177e4 LT |
1848 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1849 | va_list args) | |
1850 | { | |
1851 | int len, avail; | |
5ac52f33 | 1852 | struct sk_buff *skb; |
eecb0a73 | 1853 | va_list args2; |
1da177e4 LT |
1854 | |
1855 | if (!ab) | |
1856 | return; | |
1857 | ||
5ac52f33 CW |
1858 | BUG_ON(!ab->skb); |
1859 | skb = ab->skb; | |
1860 | avail = skb_tailroom(skb); | |
1861 | if (avail == 0) { | |
e3b926b4 | 1862 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1863 | if (!avail) |
1864 | goto out; | |
1da177e4 | 1865 | } |
eecb0a73 | 1866 | va_copy(args2, args); |
27a884dc | 1867 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1868 | if (len >= avail) { |
1869 | /* The printk buffer is 1024 bytes long, so if we get | |
1870 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1871 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1872 | avail = audit_expand(ab, |
1873 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1874 | if (!avail) |
a0e86bd4 | 1875 | goto out_va_end; |
27a884dc | 1876 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1877 | } |
168b7173 SG |
1878 | if (len > 0) |
1879 | skb_put(skb, len); | |
a0e86bd4 JJ |
1880 | out_va_end: |
1881 | va_end(args2); | |
8fc6115c CW |
1882 | out: |
1883 | return; | |
1da177e4 LT |
1884 | } |
1885 | ||
b0dd25a8 RD |
1886 | /** |
1887 | * audit_log_format - format a message into the audit buffer. | |
1888 | * @ab: audit_buffer | |
1889 | * @fmt: format string | |
1890 | * @...: optional parameters matching @fmt string | |
1891 | * | |
1892 | * All the work is done in audit_log_vformat. | |
1893 | */ | |
1da177e4 LT |
1894 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1895 | { | |
1896 | va_list args; | |
1897 | ||
1898 | if (!ab) | |
1899 | return; | |
1900 | va_start(args, fmt); | |
1901 | audit_log_vformat(ab, fmt, args); | |
1902 | va_end(args); | |
1903 | } | |
1904 | ||
b0dd25a8 | 1905 | /** |
196a5085 | 1906 | * audit_log_n_hex - convert a buffer to hex and append it to the audit skb |
b0dd25a8 RD |
1907 | * @ab: the audit_buffer |
1908 | * @buf: buffer to convert to hex | |
1909 | * @len: length of @buf to be converted | |
1910 | * | |
1911 | * No return value; failure to expand is silently ignored. | |
1912 | * | |
1913 | * This function will take the passed buf and convert it into a string of | |
1914 | * ascii hex digits. The new string is placed onto the skb. | |
1915 | */ | |
b556f8ad | 1916 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1917 | size_t len) |
83c7d091 | 1918 | { |
168b7173 SG |
1919 | int i, avail, new_len; |
1920 | unsigned char *ptr; | |
1921 | struct sk_buff *skb; | |
168b7173 | 1922 | |
8ef2d304 AG |
1923 | if (!ab) |
1924 | return; | |
1925 | ||
168b7173 SG |
1926 | BUG_ON(!ab->skb); |
1927 | skb = ab->skb; | |
1928 | avail = skb_tailroom(skb); | |
1929 | new_len = len<<1; | |
1930 | if (new_len >= avail) { | |
1931 | /* Round the buffer request up to the next multiple */ | |
1932 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1933 | avail = audit_expand(ab, new_len); | |
1934 | if (!avail) | |
1935 | return; | |
1936 | } | |
83c7d091 | 1937 | |
27a884dc | 1938 | ptr = skb_tail_pointer(skb); |
b8dbc324 JP |
1939 | for (i = 0; i < len; i++) |
1940 | ptr = hex_byte_pack_upper(ptr, buf[i]); | |
168b7173 SG |
1941 | *ptr = 0; |
1942 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1943 | } |
1944 | ||
9c937dcc AG |
1945 | /* |
1946 | * Format a string of no more than slen characters into the audit buffer, | |
1947 | * enclosed in quote marks. | |
1948 | */ | |
b556f8ad EP |
1949 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1950 | size_t slen) | |
9c937dcc AG |
1951 | { |
1952 | int avail, new_len; | |
1953 | unsigned char *ptr; | |
1954 | struct sk_buff *skb; | |
1955 | ||
8ef2d304 AG |
1956 | if (!ab) |
1957 | return; | |
1958 | ||
9c937dcc AG |
1959 | BUG_ON(!ab->skb); |
1960 | skb = ab->skb; | |
1961 | avail = skb_tailroom(skb); | |
1962 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1963 | if (new_len > avail) { | |
1964 | avail = audit_expand(ab, new_len); | |
1965 | if (!avail) | |
1966 | return; | |
1967 | } | |
27a884dc | 1968 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1969 | *ptr++ = '"'; |
1970 | memcpy(ptr, string, slen); | |
1971 | ptr += slen; | |
1972 | *ptr++ = '"'; | |
1973 | *ptr = 0; | |
1974 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1975 | } | |
1976 | ||
de6bbd1d EP |
1977 | /** |
1978 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1979 | * @string: string to be checked |
1980 | * @len: max length of the string to check | |
de6bbd1d | 1981 | */ |
9fcf836b | 1982 | bool audit_string_contains_control(const char *string, size_t len) |
de6bbd1d EP |
1983 | { |
1984 | const unsigned char *p; | |
b3897f56 | 1985 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1986 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
9fcf836b | 1987 | return true; |
de6bbd1d | 1988 | } |
9fcf836b | 1989 | return false; |
de6bbd1d EP |
1990 | } |
1991 | ||
b0dd25a8 | 1992 | /** |
522ed776 | 1993 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1994 | * @ab: audit_buffer |
f706d5d2 | 1995 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1996 | * @string: string to be logged |
1997 | * | |
1998 | * This code will escape a string that is passed to it if the string | |
1999 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 2000 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 2001 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
2002 | * |
2003 | * The caller specifies the number of characters in the string to log, which may | |
2004 | * or may not be the entire string. | |
b0dd25a8 | 2005 | */ |
b556f8ad EP |
2006 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
2007 | size_t len) | |
83c7d091 | 2008 | { |
de6bbd1d | 2009 | if (audit_string_contains_control(string, len)) |
b556f8ad | 2010 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 2011 | else |
b556f8ad | 2012 | audit_log_n_string(ab, string, len); |
83c7d091 | 2013 | } |
2014 | ||
9c937dcc | 2015 | /** |
522ed776 | 2016 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
2017 | * @ab: audit_buffer |
2018 | * @string: string to be logged | |
2019 | * | |
522ed776 | 2020 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
2021 | * determine string length. |
2022 | */ | |
de6bbd1d | 2023 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 2024 | { |
b556f8ad | 2025 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
2026 | } |
2027 | ||
168b7173 | 2028 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 2029 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 2030 | const struct path *path) |
1da177e4 | 2031 | { |
44707fdf | 2032 | char *p, *pathname; |
1da177e4 | 2033 | |
8fc6115c | 2034 | if (prefix) |
c158a35c | 2035 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 2036 | |
168b7173 | 2037 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
2038 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
2039 | if (!pathname) { | |
def57543 | 2040 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 2041 | return; |
1da177e4 | 2042 | } |
cf28b486 | 2043 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
2044 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
2045 | /* FIXME: can we save some information here? */ | |
def57543 | 2046 | audit_log_string(ab, "<too_long>"); |
5600b892 | 2047 | } else |
168b7173 | 2048 | audit_log_untrustedstring(ab, p); |
44707fdf | 2049 | kfree(pathname); |
1da177e4 LT |
2050 | } |
2051 | ||
4d3fb709 EP |
2052 | void audit_log_session_info(struct audit_buffer *ab) |
2053 | { | |
4440e854 | 2054 | unsigned int sessionid = audit_get_sessionid(current); |
4d3fb709 EP |
2055 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); |
2056 | ||
a2c97da1 | 2057 | audit_log_format(ab, "auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
2058 | } |
2059 | ||
9d960985 EP |
2060 | void audit_log_key(struct audit_buffer *ab, char *key) |
2061 | { | |
2062 | audit_log_format(ab, " key="); | |
2063 | if (key) | |
2064 | audit_log_untrustedstring(ab, key); | |
2065 | else | |
2066 | audit_log_format(ab, "(null)"); | |
2067 | } | |
2068 | ||
b24a30a7 EP |
2069 | int audit_log_task_context(struct audit_buffer *ab) |
2070 | { | |
2071 | char *ctx = NULL; | |
2072 | unsigned len; | |
2073 | int error; | |
2074 | u32 sid; | |
2075 | ||
2076 | security_task_getsecid(current, &sid); | |
2077 | if (!sid) | |
2078 | return 0; | |
2079 | ||
2080 | error = security_secid_to_secctx(sid, &ctx, &len); | |
2081 | if (error) { | |
2082 | if (error != -EINVAL) | |
2083 | goto error_path; | |
2084 | return 0; | |
2085 | } | |
2086 | ||
2087 | audit_log_format(ab, " subj=%s", ctx); | |
2088 | security_release_secctx(ctx, len); | |
2089 | return 0; | |
2090 | ||
2091 | error_path: | |
2092 | audit_panic("error in audit_log_task_context"); | |
2093 | return error; | |
2094 | } | |
2095 | EXPORT_SYMBOL(audit_log_task_context); | |
2096 | ||
4766b199 DB |
2097 | void audit_log_d_path_exe(struct audit_buffer *ab, |
2098 | struct mm_struct *mm) | |
2099 | { | |
5b282552 DB |
2100 | struct file *exe_file; |
2101 | ||
2102 | if (!mm) | |
2103 | goto out_null; | |
4766b199 | 2104 | |
5b282552 DB |
2105 | exe_file = get_mm_exe_file(mm); |
2106 | if (!exe_file) | |
2107 | goto out_null; | |
2108 | ||
2109 | audit_log_d_path(ab, " exe=", &exe_file->f_path); | |
2110 | fput(exe_file); | |
2111 | return; | |
2112 | out_null: | |
2113 | audit_log_format(ab, " exe=(null)"); | |
4766b199 DB |
2114 | } |
2115 | ||
2a1fe215 | 2116 | struct tty_struct *audit_get_tty(void) |
3f5be2da RGB |
2117 | { |
2118 | struct tty_struct *tty = NULL; | |
2119 | unsigned long flags; | |
2120 | ||
2a1fe215 PM |
2121 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
2122 | if (current->signal) | |
2123 | tty = tty_kref_get(current->signal->tty); | |
2124 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
3f5be2da RGB |
2125 | return tty; |
2126 | } | |
2127 | ||
2128 | void audit_put_tty(struct tty_struct *tty) | |
2129 | { | |
2130 | tty_kref_put(tty); | |
2131 | } | |
2132 | ||
2a1fe215 | 2133 | void audit_log_task_info(struct audit_buffer *ab) |
b24a30a7 EP |
2134 | { |
2135 | const struct cred *cred; | |
2a1fe215 | 2136 | char comm[sizeof(current->comm)]; |
db0a6fb5 | 2137 | struct tty_struct *tty; |
b24a30a7 EP |
2138 | |
2139 | if (!ab) | |
2140 | return; | |
2141 | ||
b24a30a7 | 2142 | cred = current_cred(); |
2a1fe215 | 2143 | tty = audit_get_tty(); |
b24a30a7 | 2144 | audit_log_format(ab, |
c92cdeb4 | 2145 | " ppid=%d pid=%d auid=%u uid=%u gid=%u" |
b24a30a7 | 2146 | " euid=%u suid=%u fsuid=%u" |
2f2ad101 | 2147 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", |
2a1fe215 PM |
2148 | task_ppid_nr(current), |
2149 | task_tgid_nr(current), | |
2150 | from_kuid(&init_user_ns, audit_get_loginuid(current)), | |
b24a30a7 EP |
2151 | from_kuid(&init_user_ns, cred->uid), |
2152 | from_kgid(&init_user_ns, cred->gid), | |
2153 | from_kuid(&init_user_ns, cred->euid), | |
2154 | from_kuid(&init_user_ns, cred->suid), | |
2155 | from_kuid(&init_user_ns, cred->fsuid), | |
2156 | from_kgid(&init_user_ns, cred->egid), | |
2157 | from_kgid(&init_user_ns, cred->sgid), | |
2158 | from_kgid(&init_user_ns, cred->fsgid), | |
db0a6fb5 | 2159 | tty ? tty_name(tty) : "(none)", |
2a1fe215 | 2160 | audit_get_sessionid(current)); |
db0a6fb5 | 2161 | audit_put_tty(tty); |
b24a30a7 | 2162 | audit_log_format(ab, " comm="); |
2a1fe215 PM |
2163 | audit_log_untrustedstring(ab, get_task_comm(comm, current)); |
2164 | audit_log_d_path_exe(ab, current->mm); | |
b24a30a7 EP |
2165 | audit_log_task_context(ab); |
2166 | } | |
2167 | EXPORT_SYMBOL(audit_log_task_info); | |
2168 | ||
a51d9eaa | 2169 | /** |
245d7369 KC |
2170 | * audit_log_path_denied - report a path restriction denial |
2171 | * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc) | |
2172 | * @operation: specific operation name | |
a51d9eaa | 2173 | */ |
245d7369 | 2174 | void audit_log_path_denied(int type, const char *operation) |
a51d9eaa KC |
2175 | { |
2176 | struct audit_buffer *ab; | |
b24a30a7 | 2177 | |
15564ff0 | 2178 | if (!audit_enabled || audit_dummy_context()) |
b24a30a7 | 2179 | return; |
a51d9eaa | 2180 | |
245d7369 KC |
2181 | /* Generate log with subject, operation, outcome. */ |
2182 | ab = audit_log_start(audit_context(), GFP_KERNEL, type); | |
d1c7d97a | 2183 | if (!ab) |
45b578fe | 2184 | return; |
b24a30a7 | 2185 | audit_log_format(ab, "op=%s", operation); |
2a1fe215 | 2186 | audit_log_task_info(ab); |
b24a30a7 | 2187 | audit_log_format(ab, " res=0"); |
a51d9eaa KC |
2188 | audit_log_end(ab); |
2189 | } | |
2190 | ||
4b7d248b RGB |
2191 | /* global counter which is incremented every time something logs in */ |
2192 | static atomic_t session_id = ATOMIC_INIT(0); | |
2193 | ||
2194 | static int audit_set_loginuid_perm(kuid_t loginuid) | |
2195 | { | |
2196 | /* if we are unset, we don't need privs */ | |
2197 | if (!audit_loginuid_set(current)) | |
2198 | return 0; | |
2199 | /* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/ | |
2200 | if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE)) | |
2201 | return -EPERM; | |
2202 | /* it is set, you need permission */ | |
2203 | if (!capable(CAP_AUDIT_CONTROL)) | |
2204 | return -EPERM; | |
2205 | /* reject if this is not an unset and we don't allow that */ | |
2206 | if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) | |
2207 | && uid_valid(loginuid)) | |
2208 | return -EPERM; | |
2209 | return 0; | |
2210 | } | |
2211 | ||
2212 | static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid, | |
2213 | unsigned int oldsessionid, | |
2214 | unsigned int sessionid, int rc) | |
2215 | { | |
2216 | struct audit_buffer *ab; | |
2217 | uid_t uid, oldloginuid, loginuid; | |
2218 | struct tty_struct *tty; | |
2219 | ||
2220 | if (!audit_enabled) | |
2221 | return; | |
2222 | ||
73e65b88 | 2223 | ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN); |
4b7d248b RGB |
2224 | if (!ab) |
2225 | return; | |
2226 | ||
2227 | uid = from_kuid(&init_user_ns, task_uid(current)); | |
2228 | oldloginuid = from_kuid(&init_user_ns, koldloginuid); | |
2229 | loginuid = from_kuid(&init_user_ns, kloginuid), | |
2230 | tty = audit_get_tty(); | |
2231 | ||
2232 | audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid); | |
2233 | audit_log_task_context(ab); | |
2234 | audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d", | |
2235 | oldloginuid, loginuid, tty ? tty_name(tty) : "(none)", | |
2236 | oldsessionid, sessionid, !rc); | |
2237 | audit_put_tty(tty); | |
2238 | audit_log_end(ab); | |
2239 | } | |
2240 | ||
2241 | /** | |
2242 | * audit_set_loginuid - set current task's loginuid | |
2243 | * @loginuid: loginuid value | |
2244 | * | |
2245 | * Returns 0. | |
2246 | * | |
2247 | * Called (set) from fs/proc/base.c::proc_loginuid_write(). | |
2248 | */ | |
2249 | int audit_set_loginuid(kuid_t loginuid) | |
2250 | { | |
2251 | unsigned int oldsessionid, sessionid = AUDIT_SID_UNSET; | |
2252 | kuid_t oldloginuid; | |
2253 | int rc; | |
2254 | ||
2255 | oldloginuid = audit_get_loginuid(current); | |
2256 | oldsessionid = audit_get_sessionid(current); | |
2257 | ||
2258 | rc = audit_set_loginuid_perm(loginuid); | |
2259 | if (rc) | |
2260 | goto out; | |
2261 | ||
2262 | /* are we setting or clearing? */ | |
2263 | if (uid_valid(loginuid)) { | |
2264 | sessionid = (unsigned int)atomic_inc_return(&session_id); | |
2265 | if (unlikely(sessionid == AUDIT_SID_UNSET)) | |
2266 | sessionid = (unsigned int)atomic_inc_return(&session_id); | |
2267 | } | |
2268 | ||
2269 | current->sessionid = sessionid; | |
2270 | current->loginuid = loginuid; | |
2271 | out: | |
2272 | audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc); | |
2273 | return rc; | |
2274 | } | |
2275 | ||
b48345aa RGB |
2276 | /** |
2277 | * audit_signal_info - record signal info for shutting down audit subsystem | |
2278 | * @sig: signal value | |
2279 | * @t: task being signaled | |
2280 | * | |
2281 | * If the audit subsystem is being terminated, record the task (pid) | |
2282 | * and uid that is doing that. | |
2283 | */ | |
2284 | int audit_signal_info(int sig, struct task_struct *t) | |
2285 | { | |
2286 | kuid_t uid = current_uid(), auid; | |
2287 | ||
2288 | if (auditd_test_task(t) && | |
2289 | (sig == SIGTERM || sig == SIGHUP || | |
2290 | sig == SIGUSR1 || sig == SIGUSR2)) { | |
2291 | audit_sig_pid = task_tgid_nr(current); | |
2292 | auid = audit_get_loginuid(current); | |
2293 | if (uid_valid(auid)) | |
2294 | audit_sig_uid = auid; | |
2295 | else | |
2296 | audit_sig_uid = uid; | |
2297 | security_task_getsecid(current, &audit_sig_sid); | |
2298 | } | |
2299 | ||
2300 | return audit_signal_info_syscall(t); | |
2301 | } | |
2302 | ||
b0dd25a8 RD |
2303 | /** |
2304 | * audit_log_end - end one audit record | |
2305 | * @ab: the audit_buffer | |
2306 | * | |
4aa83872 PM |
2307 | * We can not do a netlink send inside an irq context because it blocks (last |
2308 | * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a | |
2309 | * queue and a tasklet is scheduled to remove them from the queue outside the | |
2310 | * irq context. May be called in any context. | |
b0dd25a8 | 2311 | */ |
b7d11258 | 2312 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 2313 | { |
5b52330b PM |
2314 | struct sk_buff *skb; |
2315 | struct nlmsghdr *nlh; | |
2316 | ||
1da177e4 LT |
2317 | if (!ab) |
2318 | return; | |
5b52330b PM |
2319 | |
2320 | if (audit_rate_check()) { | |
2321 | skb = ab->skb; | |
f3d357b0 | 2322 | ab->skb = NULL; |
5b52330b PM |
2323 | |
2324 | /* setup the netlink header, see the comments in | |
2325 | * kauditd_send_multicast_skb() for length quirks */ | |
2326 | nlh = nlmsg_hdr(skb); | |
2327 | nlh->nlmsg_len = skb->len - NLMSG_HDRLEN; | |
2328 | ||
2329 | /* queue the netlink packet and poke the kauditd thread */ | |
2330 | skb_queue_tail(&audit_queue, skb); | |
2331 | wake_up_interruptible(&kauditd_wait); | |
2332 | } else | |
2333 | audit_log_lost("rate limit exceeded"); | |
2334 | ||
16e1904e | 2335 | audit_buffer_free(ab); |
1da177e4 LT |
2336 | } |
2337 | ||
b0dd25a8 RD |
2338 | /** |
2339 | * audit_log - Log an audit record | |
2340 | * @ctx: audit context | |
2341 | * @gfp_mask: type of allocation | |
2342 | * @type: audit message type | |
2343 | * @fmt: format string to use | |
2344 | * @...: variable parameters matching the format string | |
2345 | * | |
2346 | * This is a convenience function that calls audit_log_start, | |
2347 | * audit_log_vformat, and audit_log_end. It may be called | |
2348 | * in any context. | |
2349 | */ | |
5600b892 | 2350 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 2351 | const char *fmt, ...) |
1da177e4 LT |
2352 | { |
2353 | struct audit_buffer *ab; | |
2354 | va_list args; | |
2355 | ||
9ad9ad38 | 2356 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
2357 | if (ab) { |
2358 | va_start(args, fmt); | |
2359 | audit_log_vformat(ab, fmt, args); | |
2360 | va_end(args); | |
2361 | audit_log_end(ab); | |
2362 | } | |
2363 | } | |
bf45da97 | 2364 | |
2365 | EXPORT_SYMBOL(audit_log_start); | |
2366 | EXPORT_SYMBOL(audit_log_end); | |
2367 | EXPORT_SYMBOL(audit_log_format); | |
2368 | EXPORT_SYMBOL(audit_log); |