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85c8721f | 1 | /* audit.c -- Auditing support |
1da177e4 LT |
2 | * Gateway between the kernel (e.g., selinux) and the user-space audit daemon. |
3 | * System-call specific features have moved to auditsc.c | |
4 | * | |
6a01b07f | 5 | * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina. |
1da177e4 LT |
6 | * All Rights Reserved. |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
21 | * | |
22 | * Written by Rickard E. (Rik) Faith <faith@redhat.com> | |
23 | * | |
d7a96f3a | 24 | * Goals: 1) Integrate fully with Security Modules. |
1da177e4 LT |
25 | * 2) Minimal run-time overhead: |
26 | * a) Minimal when syscall auditing is disabled (audit_enable=0). | |
27 | * b) Small when syscall auditing is enabled and no audit record | |
28 | * is generated (defer as much work as possible to record | |
29 | * generation time): | |
30 | * i) context is allocated, | |
31 | * ii) names from getname are stored without a copy, and | |
32 | * iii) inode information stored from path_lookup. | |
33 | * 3) Ability to disable syscall auditing at boot time (audit=0). | |
34 | * 4) Usable by other parts of the kernel (if audit_log* is called, | |
35 | * then a syscall record will be generated automatically for the | |
36 | * current syscall). | |
37 | * 5) Netlink interface to user-space. | |
38 | * 6) Support low-overhead kernel-based filtering to minimize the | |
39 | * information that must be passed to user-space. | |
40 | * | |
d590dca6 RGB |
41 | * Audit userspace, documentation, tests, and bug/issue trackers: |
42 | * https://github.com/linux-audit | |
1da177e4 LT |
43 | */ |
44 | ||
d957f7b7 JP |
45 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
46 | ||
5b282552 | 47 | #include <linux/file.h> |
1da177e4 | 48 | #include <linux/init.h> |
7153e402 | 49 | #include <linux/types.h> |
60063497 | 50 | #include <linux/atomic.h> |
1da177e4 | 51 | #include <linux/mm.h> |
9984de1a | 52 | #include <linux/export.h> |
5a0e3ad6 | 53 | #include <linux/slab.h> |
b7d11258 DW |
54 | #include <linux/err.h> |
55 | #include <linux/kthread.h> | |
46e959ea | 56 | #include <linux/kernel.h> |
b24a30a7 | 57 | #include <linux/syscalls.h> |
5b52330b PM |
58 | #include <linux/spinlock.h> |
59 | #include <linux/rcupdate.h> | |
60 | #include <linux/mutex.h> | |
61 | #include <linux/gfp.h> | |
b6c7c115 | 62 | #include <linux/pid.h> |
8cc96382 | 63 | #include <linux/slab.h> |
1da177e4 LT |
64 | |
65 | #include <linux/audit.h> | |
66 | ||
67 | #include <net/sock.h> | |
93315ed6 | 68 | #include <net/netlink.h> |
1da177e4 | 69 | #include <linux/skbuff.h> |
131ad62d MDF |
70 | #ifdef CONFIG_SECURITY |
71 | #include <linux/security.h> | |
72 | #endif | |
7dfb7103 | 73 | #include <linux/freezer.h> |
34e36d8e | 74 | #include <linux/pid_namespace.h> |
33faba7f | 75 | #include <net/netns/generic.h> |
3dc7e315 DG |
76 | |
77 | #include "audit.h" | |
1da177e4 | 78 | |
a3f07114 | 79 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 80 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
81 | #define AUDIT_DISABLED -1 |
82 | #define AUDIT_UNINITIALIZED 0 | |
83 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
84 | static int audit_initialized; |
85 | ||
1a6b9f23 EP |
86 | #define AUDIT_OFF 0 |
87 | #define AUDIT_ON 1 | |
88 | #define AUDIT_LOCKED 2 | |
173743dd | 89 | u32 audit_enabled = AUDIT_OFF; |
b3b4fdf6 | 90 | bool audit_ever_enabled = !!AUDIT_OFF; |
1da177e4 | 91 | |
ae9d67af JE |
92 | EXPORT_SYMBOL_GPL(audit_enabled); |
93 | ||
1da177e4 | 94 | /* Default state when kernel boots without any parameters. */ |
173743dd | 95 | static u32 audit_default = AUDIT_OFF; |
1da177e4 LT |
96 | |
97 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
3e1d0bb6 | 98 | static u32 audit_failure = AUDIT_FAIL_PRINTK; |
1da177e4 | 99 | |
5b52330b PM |
100 | /* private audit network namespace index */ |
101 | static unsigned int audit_net_id; | |
102 | ||
103 | /** | |
104 | * struct audit_net - audit private network namespace data | |
105 | * @sk: communication socket | |
106 | */ | |
107 | struct audit_net { | |
108 | struct sock *sk; | |
109 | }; | |
110 | ||
111 | /** | |
112 | * struct auditd_connection - kernel/auditd connection state | |
113 | * @pid: auditd PID | |
114 | * @portid: netlink portid | |
115 | * @net: the associated network namespace | |
48d0e023 | 116 | * @rcu: RCU head |
5b52330b PM |
117 | * |
118 | * Description: | |
119 | * This struct is RCU protected; you must either hold the RCU lock for reading | |
48d0e023 | 120 | * or the associated spinlock for writing. |
75c0371a | 121 | */ |
5b52330b | 122 | static struct auditd_connection { |
b6c7c115 | 123 | struct pid *pid; |
5b52330b PM |
124 | u32 portid; |
125 | struct net *net; | |
48d0e023 PM |
126 | struct rcu_head rcu; |
127 | } *auditd_conn = NULL; | |
128 | static DEFINE_SPINLOCK(auditd_conn_lock); | |
1da177e4 | 129 | |
b0dd25a8 | 130 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
131 | * to that number per second. This prevents DoS attacks, but results in |
132 | * audit records being dropped. */ | |
3e1d0bb6 | 133 | static u32 audit_rate_limit; |
1da177e4 | 134 | |
40c0775e RGB |
135 | /* Number of outstanding audit_buffers allowed. |
136 | * When set to zero, this means unlimited. */ | |
3e1d0bb6 | 137 | static u32 audit_backlog_limit = 64; |
e789e561 | 138 | #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ) |
3e1d0bb6 | 139 | static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; |
1da177e4 | 140 | |
c2f0c7c3 | 141 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 142 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 143 | pid_t audit_sig_pid = -1; |
e1396065 | 144 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 145 | |
1da177e4 LT |
146 | /* Records can be lost in several ways: |
147 | 0) [suppressed in audit_alloc] | |
148 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
149 | 2) out of memory in audit_log_move [alloc_skb] | |
150 | 3) suppressed due to audit_rate_limit | |
151 | 4) suppressed due to audit_backlog_limit | |
152 | */ | |
92c82e8a | 153 | static atomic_t audit_lost = ATOMIC_INIT(0); |
1da177e4 | 154 | |
f368c07d AG |
155 | /* Hash for inode-based rules */ |
156 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
157 | ||
8cc96382 | 158 | static struct kmem_cache *audit_buffer_cache; |
1da177e4 | 159 | |
c6480207 | 160 | /* queue msgs to send via kauditd_task */ |
af8b824f | 161 | static struct sk_buff_head audit_queue; |
c6480207 PM |
162 | /* queue msgs due to temporary unicast send problems */ |
163 | static struct sk_buff_head audit_retry_queue; | |
164 | /* queue msgs waiting for new auditd connection */ | |
af8b824f | 165 | static struct sk_buff_head audit_hold_queue; |
c6480207 PM |
166 | |
167 | /* queue servicing thread */ | |
b7d11258 DW |
168 | static struct task_struct *kauditd_task; |
169 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
c6480207 PM |
170 | |
171 | /* waitqueue for callers who are blocked on the audit backlog */ | |
9ad9ad38 | 172 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 173 | |
b0fed402 EP |
174 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
175 | .mask = -1, | |
176 | .features = 0, | |
177 | .lock = 0,}; | |
178 | ||
21b85c31 | 179 | static char *audit_feature_names[2] = { |
d040e5af | 180 | "only_unset_loginuid", |
21b85c31 | 181 | "loginuid_immutable", |
b0fed402 EP |
182 | }; |
183 | ||
184 | ||
f368c07d | 185 | /* Serialize requests from userspace. */ |
916d7576 | 186 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
187 | |
188 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
189 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
190 | * should be at least that large. */ | |
191 | #define AUDIT_BUFSIZ 1024 | |
192 | ||
1da177e4 LT |
193 | /* The audit_buffer is used when formatting an audit record. The caller |
194 | * locks briefly to get the record off the freelist or to allocate the | |
195 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
196 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
197 | * use simultaneously. */ | |
198 | struct audit_buffer { | |
8fc6115c | 199 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 200 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 201 | gfp_t gfp_mask; |
1da177e4 LT |
202 | }; |
203 | ||
f09ac9db | 204 | struct audit_reply { |
f9441639 | 205 | __u32 portid; |
638a0fd2 | 206 | struct net *net; |
f09ac9db EP |
207 | struct sk_buff *skb; |
208 | }; | |
209 | ||
5b52330b PM |
210 | /** |
211 | * auditd_test_task - Check to see if a given task is an audit daemon | |
212 | * @task: the task to check | |
213 | * | |
214 | * Description: | |
215 | * Return 1 if the task is a registered audit daemon, 0 otherwise. | |
216 | */ | |
b6c7c115 | 217 | int auditd_test_task(struct task_struct *task) |
5b52330b PM |
218 | { |
219 | int rc; | |
48d0e023 | 220 | struct auditd_connection *ac; |
5b52330b PM |
221 | |
222 | rcu_read_lock(); | |
48d0e023 PM |
223 | ac = rcu_dereference(auditd_conn); |
224 | rc = (ac && ac->pid == task_tgid(task) ? 1 : 0); | |
5b52330b PM |
225 | rcu_read_unlock(); |
226 | ||
227 | return rc; | |
228 | } | |
229 | ||
b6c7c115 PM |
230 | /** |
231 | * auditd_pid_vnr - Return the auditd PID relative to the namespace | |
b6c7c115 PM |
232 | * |
233 | * Description: | |
48d0e023 | 234 | * Returns the PID in relation to the namespace, 0 on failure. |
b6c7c115 | 235 | */ |
48d0e023 | 236 | static pid_t auditd_pid_vnr(void) |
b6c7c115 PM |
237 | { |
238 | pid_t pid; | |
48d0e023 | 239 | const struct auditd_connection *ac; |
b6c7c115 PM |
240 | |
241 | rcu_read_lock(); | |
48d0e023 PM |
242 | ac = rcu_dereference(auditd_conn); |
243 | if (!ac || !ac->pid) | |
b6c7c115 PM |
244 | pid = 0; |
245 | else | |
48d0e023 | 246 | pid = pid_vnr(ac->pid); |
b6c7c115 PM |
247 | rcu_read_unlock(); |
248 | ||
249 | return pid; | |
250 | } | |
251 | ||
5b52330b PM |
252 | /** |
253 | * audit_get_sk - Return the audit socket for the given network namespace | |
254 | * @net: the destination network namespace | |
255 | * | |
256 | * Description: | |
257 | * Returns the sock pointer if valid, NULL otherwise. The caller must ensure | |
258 | * that a reference is held for the network namespace while the sock is in use. | |
259 | */ | |
260 | static struct sock *audit_get_sk(const struct net *net) | |
261 | { | |
262 | struct audit_net *aunet; | |
263 | ||
264 | if (!net) | |
265 | return NULL; | |
266 | ||
267 | aunet = net_generic(net, audit_net_id); | |
268 | return aunet->sk; | |
269 | } | |
270 | ||
8c8570fb | 271 | void audit_panic(const char *message) |
1da177e4 | 272 | { |
d957f7b7 | 273 | switch (audit_failure) { |
1da177e4 LT |
274 | case AUDIT_FAIL_SILENT: |
275 | break; | |
276 | case AUDIT_FAIL_PRINTK: | |
320f1b1e | 277 | if (printk_ratelimit()) |
d957f7b7 | 278 | pr_err("%s\n", message); |
1da177e4 LT |
279 | break; |
280 | case AUDIT_FAIL_PANIC: | |
5b52330b | 281 | panic("audit: %s\n", message); |
1da177e4 LT |
282 | break; |
283 | } | |
284 | } | |
285 | ||
286 | static inline int audit_rate_check(void) | |
287 | { | |
288 | static unsigned long last_check = 0; | |
289 | static int messages = 0; | |
290 | static DEFINE_SPINLOCK(lock); | |
291 | unsigned long flags; | |
292 | unsigned long now; | |
293 | unsigned long elapsed; | |
294 | int retval = 0; | |
295 | ||
296 | if (!audit_rate_limit) return 1; | |
297 | ||
298 | spin_lock_irqsave(&lock, flags); | |
299 | if (++messages < audit_rate_limit) { | |
300 | retval = 1; | |
301 | } else { | |
302 | now = jiffies; | |
303 | elapsed = now - last_check; | |
304 | if (elapsed > HZ) { | |
305 | last_check = now; | |
306 | messages = 0; | |
307 | retval = 1; | |
308 | } | |
309 | } | |
310 | spin_unlock_irqrestore(&lock, flags); | |
311 | ||
312 | return retval; | |
313 | } | |
314 | ||
b0dd25a8 RD |
315 | /** |
316 | * audit_log_lost - conditionally log lost audit message event | |
317 | * @message: the message stating reason for lost audit message | |
318 | * | |
319 | * Emit at least 1 message per second, even if audit_rate_check is | |
320 | * throttling. | |
321 | * Always increment the lost messages counter. | |
322 | */ | |
1da177e4 LT |
323 | void audit_log_lost(const char *message) |
324 | { | |
325 | static unsigned long last_msg = 0; | |
326 | static DEFINE_SPINLOCK(lock); | |
327 | unsigned long flags; | |
328 | unsigned long now; | |
329 | int print; | |
330 | ||
331 | atomic_inc(&audit_lost); | |
332 | ||
333 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
334 | ||
335 | if (!print) { | |
336 | spin_lock_irqsave(&lock, flags); | |
337 | now = jiffies; | |
338 | if (now - last_msg > HZ) { | |
339 | print = 1; | |
340 | last_msg = now; | |
341 | } | |
342 | spin_unlock_irqrestore(&lock, flags); | |
343 | } | |
344 | ||
345 | if (print) { | |
320f1b1e | 346 | if (printk_ratelimit()) |
3e1d0bb6 | 347 | pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n", |
320f1b1e EP |
348 | atomic_read(&audit_lost), |
349 | audit_rate_limit, | |
350 | audit_backlog_limit); | |
1da177e4 LT |
351 | audit_panic(message); |
352 | } | |
1da177e4 LT |
353 | } |
354 | ||
3e1d0bb6 | 355 | static int audit_log_config_change(char *function_name, u32 new, u32 old, |
2532386f | 356 | int allow_changes) |
1da177e4 | 357 | { |
1a6b9f23 EP |
358 | struct audit_buffer *ab; |
359 | int rc = 0; | |
ce29b682 | 360 | |
1a6b9f23 | 361 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
362 | if (unlikely(!ab)) |
363 | return rc; | |
3e1d0bb6 | 364 | audit_log_format(ab, "%s=%u old=%u", function_name, new, old); |
4d3fb709 | 365 | audit_log_session_info(ab); |
b122c376 EP |
366 | rc = audit_log_task_context(ab); |
367 | if (rc) | |
368 | allow_changes = 0; /* Something weird, deny request */ | |
1a6b9f23 EP |
369 | audit_log_format(ab, " res=%d", allow_changes); |
370 | audit_log_end(ab); | |
6a01b07f | 371 | return rc; |
1da177e4 LT |
372 | } |
373 | ||
3e1d0bb6 | 374 | static int audit_do_config_change(char *function_name, u32 *to_change, u32 new) |
1da177e4 | 375 | { |
3e1d0bb6 JP |
376 | int allow_changes, rc = 0; |
377 | u32 old = *to_change; | |
6a01b07f SG |
378 | |
379 | /* check if we are locked */ | |
1a6b9f23 EP |
380 | if (audit_enabled == AUDIT_LOCKED) |
381 | allow_changes = 0; | |
6a01b07f | 382 | else |
1a6b9f23 | 383 | allow_changes = 1; |
ce29b682 | 384 | |
1a6b9f23 | 385 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 386 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
387 | if (rc) |
388 | allow_changes = 0; | |
6a01b07f | 389 | } |
6a01b07f SG |
390 | |
391 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
392 | if (allow_changes == 1) |
393 | *to_change = new; | |
6a01b07f SG |
394 | /* Not allowed, update reason */ |
395 | else if (rc == 0) | |
396 | rc = -EPERM; | |
397 | return rc; | |
1da177e4 LT |
398 | } |
399 | ||
3e1d0bb6 | 400 | static int audit_set_rate_limit(u32 limit) |
1da177e4 | 401 | { |
dc9eb698 | 402 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 403 | } |
ce29b682 | 404 | |
3e1d0bb6 | 405 | static int audit_set_backlog_limit(u32 limit) |
1a6b9f23 | 406 | { |
dc9eb698 | 407 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 408 | } |
6a01b07f | 409 | |
3e1d0bb6 | 410 | static int audit_set_backlog_wait_time(u32 timeout) |
51cc83f0 RGB |
411 | { |
412 | return audit_do_config_change("audit_backlog_wait_time", | |
31975424 | 413 | &audit_backlog_wait_time, timeout); |
51cc83f0 RGB |
414 | } |
415 | ||
3e1d0bb6 | 416 | static int audit_set_enabled(u32 state) |
1a6b9f23 | 417 | { |
b593d384 | 418 | int rc; |
724e7bfc | 419 | if (state > AUDIT_LOCKED) |
1a6b9f23 | 420 | return -EINVAL; |
6a01b07f | 421 | |
dc9eb698 | 422 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
423 | if (!rc) |
424 | audit_ever_enabled |= !!state; | |
425 | ||
426 | return rc; | |
1da177e4 LT |
427 | } |
428 | ||
3e1d0bb6 | 429 | static int audit_set_failure(u32 state) |
1da177e4 | 430 | { |
1da177e4 LT |
431 | if (state != AUDIT_FAIL_SILENT |
432 | && state != AUDIT_FAIL_PRINTK | |
433 | && state != AUDIT_FAIL_PANIC) | |
434 | return -EINVAL; | |
ce29b682 | 435 | |
dc9eb698 | 436 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
437 | } |
438 | ||
48d0e023 PM |
439 | /** |
440 | * auditd_conn_free - RCU helper to release an auditd connection struct | |
441 | * @rcu: RCU head | |
442 | * | |
443 | * Description: | |
444 | * Drop any references inside the auditd connection tracking struct and free | |
445 | * the memory. | |
446 | */ | |
447 | static void auditd_conn_free(struct rcu_head *rcu) | |
448 | { | |
449 | struct auditd_connection *ac; | |
450 | ||
451 | ac = container_of(rcu, struct auditd_connection, rcu); | |
452 | put_pid(ac->pid); | |
453 | put_net(ac->net); | |
454 | kfree(ac); | |
455 | } | |
456 | ||
5b52330b PM |
457 | /** |
458 | * auditd_set - Set/Reset the auditd connection state | |
459 | * @pid: auditd PID | |
460 | * @portid: auditd netlink portid | |
461 | * @net: auditd network namespace pointer | |
462 | * | |
463 | * Description: | |
464 | * This function will obtain and drop network namespace references as | |
48d0e023 | 465 | * necessary. Returns zero on success, negative values on failure. |
5b52330b | 466 | */ |
48d0e023 | 467 | static int auditd_set(struct pid *pid, u32 portid, struct net *net) |
5b52330b PM |
468 | { |
469 | unsigned long flags; | |
48d0e023 | 470 | struct auditd_connection *ac_old, *ac_new; |
5b52330b | 471 | |
48d0e023 PM |
472 | if (!pid || !net) |
473 | return -EINVAL; | |
474 | ||
475 | ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL); | |
476 | if (!ac_new) | |
477 | return -ENOMEM; | |
478 | ac_new->pid = get_pid(pid); | |
479 | ac_new->portid = portid; | |
480 | ac_new->net = get_net(net); | |
481 | ||
482 | spin_lock_irqsave(&auditd_conn_lock, flags); | |
483 | ac_old = rcu_dereference_protected(auditd_conn, | |
484 | lockdep_is_held(&auditd_conn_lock)); | |
485 | rcu_assign_pointer(auditd_conn, ac_new); | |
486 | spin_unlock_irqrestore(&auditd_conn_lock, flags); | |
487 | ||
488 | if (ac_old) | |
489 | call_rcu(&ac_old->rcu, auditd_conn_free); | |
490 | ||
491 | return 0; | |
5b52330b PM |
492 | } |
493 | ||
5b52330b PM |
494 | /** |
495 | * kauditd_print_skb - Print the audit record to the ring buffer | |
496 | * @skb: audit record | |
497 | * | |
498 | * Whatever the reason, this packet may not make it to the auditd connection | |
499 | * so write it via printk so the information isn't completely lost. | |
038cbcf6 | 500 | */ |
af8b824f | 501 | static void kauditd_printk_skb(struct sk_buff *skb) |
038cbcf6 EP |
502 | { |
503 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 504 | char *data = nlmsg_data(nlh); |
038cbcf6 | 505 | |
5b52330b PM |
506 | if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit()) |
507 | pr_notice("type=%d %s\n", nlh->nlmsg_type, data); | |
508 | } | |
509 | ||
510 | /** | |
511 | * kauditd_rehold_skb - Handle a audit record send failure in the hold queue | |
512 | * @skb: audit record | |
513 | * | |
514 | * Description: | |
515 | * This should only be used by the kauditd_thread when it fails to flush the | |
516 | * hold queue. | |
517 | */ | |
518 | static void kauditd_rehold_skb(struct sk_buff *skb) | |
519 | { | |
520 | /* put the record back in the queue at the same place */ | |
521 | skb_queue_head(&audit_hold_queue, skb); | |
c6480207 PM |
522 | } |
523 | ||
524 | /** | |
525 | * kauditd_hold_skb - Queue an audit record, waiting for auditd | |
526 | * @skb: audit record | |
527 | * | |
528 | * Description: | |
529 | * Queue the audit record, waiting for an instance of auditd. When this | |
530 | * function is called we haven't given up yet on sending the record, but things | |
531 | * are not looking good. The first thing we want to do is try to write the | |
532 | * record via printk and then see if we want to try and hold on to the record | |
533 | * and queue it, if we have room. If we want to hold on to the record, but we | |
534 | * don't have room, record a record lost message. | |
535 | */ | |
536 | static void kauditd_hold_skb(struct sk_buff *skb) | |
537 | { | |
538 | /* at this point it is uncertain if we will ever send this to auditd so | |
539 | * try to send the message via printk before we go any further */ | |
540 | kauditd_printk_skb(skb); | |
541 | ||
542 | /* can we just silently drop the message? */ | |
543 | if (!audit_default) { | |
544 | kfree_skb(skb); | |
545 | return; | |
546 | } | |
547 | ||
548 | /* if we have room, queue the message */ | |
549 | if (!audit_backlog_limit || | |
550 | skb_queue_len(&audit_hold_queue) < audit_backlog_limit) { | |
551 | skb_queue_tail(&audit_hold_queue, skb); | |
552 | return; | |
553 | } | |
038cbcf6 | 554 | |
c6480207 PM |
555 | /* we have no other options - drop the message */ |
556 | audit_log_lost("kauditd hold queue overflow"); | |
557 | kfree_skb(skb); | |
038cbcf6 EP |
558 | } |
559 | ||
c6480207 PM |
560 | /** |
561 | * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd | |
562 | * @skb: audit record | |
563 | * | |
564 | * Description: | |
565 | * Not as serious as kauditd_hold_skb() as we still have a connected auditd, | |
566 | * but for some reason we are having problems sending it audit records so | |
567 | * queue the given record and attempt to resend. | |
568 | */ | |
569 | static void kauditd_retry_skb(struct sk_buff *skb) | |
f3d357b0 | 570 | { |
c6480207 PM |
571 | /* NOTE: because records should only live in the retry queue for a |
572 | * short period of time, before either being sent or moved to the hold | |
573 | * queue, we don't currently enforce a limit on this queue */ | |
574 | skb_queue_tail(&audit_retry_queue, skb); | |
575 | } | |
32a1dbae | 576 | |
264d5096 PM |
577 | /** |
578 | * auditd_reset - Disconnect the auditd connection | |
c81be52a | 579 | * @ac: auditd connection state |
264d5096 PM |
580 | * |
581 | * Description: | |
582 | * Break the auditd/kauditd connection and move all the queued records into the | |
c81be52a PM |
583 | * hold queue in case auditd reconnects. It is important to note that the @ac |
584 | * pointer should never be dereferenced inside this function as it may be NULL | |
585 | * or invalid, you can only compare the memory address! If @ac is NULL then | |
586 | * the connection will always be reset. | |
264d5096 | 587 | */ |
c81be52a | 588 | static void auditd_reset(const struct auditd_connection *ac) |
264d5096 | 589 | { |
48d0e023 | 590 | unsigned long flags; |
264d5096 | 591 | struct sk_buff *skb; |
48d0e023 | 592 | struct auditd_connection *ac_old; |
264d5096 PM |
593 | |
594 | /* if it isn't already broken, break the connection */ | |
48d0e023 PM |
595 | spin_lock_irqsave(&auditd_conn_lock, flags); |
596 | ac_old = rcu_dereference_protected(auditd_conn, | |
597 | lockdep_is_held(&auditd_conn_lock)); | |
c81be52a PM |
598 | if (ac && ac != ac_old) { |
599 | /* someone already registered a new auditd connection */ | |
600 | spin_unlock_irqrestore(&auditd_conn_lock, flags); | |
601 | return; | |
602 | } | |
48d0e023 PM |
603 | rcu_assign_pointer(auditd_conn, NULL); |
604 | spin_unlock_irqrestore(&auditd_conn_lock, flags); | |
605 | ||
606 | if (ac_old) | |
607 | call_rcu(&ac_old->rcu, auditd_conn_free); | |
264d5096 | 608 | |
cd33f5f2 PM |
609 | /* flush the retry queue to the hold queue, but don't touch the main |
610 | * queue since we need to process that normally for multicast */ | |
264d5096 PM |
611 | while ((skb = skb_dequeue(&audit_retry_queue))) |
612 | kauditd_hold_skb(skb); | |
264d5096 PM |
613 | } |
614 | ||
c6480207 | 615 | /** |
5b52330b PM |
616 | * auditd_send_unicast_skb - Send a record via unicast to auditd |
617 | * @skb: audit record | |
c6480207 PM |
618 | * |
619 | * Description: | |
5b52330b PM |
620 | * Send a skb to the audit daemon, returns positive/zero values on success and |
621 | * negative values on failure; in all cases the skb will be consumed by this | |
622 | * function. If the send results in -ECONNREFUSED the connection with auditd | |
623 | * will be reset. This function may sleep so callers should not hold any locks | |
624 | * where this would cause a problem. | |
c6480207 | 625 | */ |
5b52330b | 626 | static int auditd_send_unicast_skb(struct sk_buff *skb) |
c6480207 | 627 | { |
5b52330b PM |
628 | int rc; |
629 | u32 portid; | |
630 | struct net *net; | |
631 | struct sock *sk; | |
48d0e023 | 632 | struct auditd_connection *ac; |
5b52330b PM |
633 | |
634 | /* NOTE: we can't call netlink_unicast while in the RCU section so | |
635 | * take a reference to the network namespace and grab local | |
636 | * copies of the namespace, the sock, and the portid; the | |
637 | * namespace and sock aren't going to go away while we hold a | |
638 | * reference and if the portid does become invalid after the RCU | |
639 | * section netlink_unicast() should safely return an error */ | |
640 | ||
641 | rcu_read_lock(); | |
48d0e023 PM |
642 | ac = rcu_dereference(auditd_conn); |
643 | if (!ac) { | |
5b52330b | 644 | rcu_read_unlock(); |
b0659ae5 | 645 | kfree_skb(skb); |
5b52330b PM |
646 | rc = -ECONNREFUSED; |
647 | goto err; | |
533c7b69 | 648 | } |
48d0e023 | 649 | net = get_net(ac->net); |
5b52330b | 650 | sk = audit_get_sk(net); |
48d0e023 | 651 | portid = ac->portid; |
5b52330b | 652 | rcu_read_unlock(); |
c6480207 | 653 | |
5b52330b PM |
654 | rc = netlink_unicast(sk, skb, portid, 0); |
655 | put_net(net); | |
656 | if (rc < 0) | |
657 | goto err; | |
658 | ||
659 | return rc; | |
660 | ||
661 | err: | |
c81be52a PM |
662 | if (ac && rc == -ECONNREFUSED) |
663 | auditd_reset(ac); | |
5b52330b | 664 | return rc; |
c6480207 PM |
665 | } |
666 | ||
667 | /** | |
5b52330b PM |
668 | * kauditd_send_queue - Helper for kauditd_thread to flush skb queues |
669 | * @sk: the sending sock | |
670 | * @portid: the netlink destination | |
671 | * @queue: the skb queue to process | |
672 | * @retry_limit: limit on number of netlink unicast failures | |
673 | * @skb_hook: per-skb hook for additional processing | |
674 | * @err_hook: hook called if the skb fails the netlink unicast send | |
675 | * | |
676 | * Description: | |
677 | * Run through the given queue and attempt to send the audit records to auditd, | |
678 | * returns zero on success, negative values on failure. It is up to the caller | |
679 | * to ensure that the @sk is valid for the duration of this function. | |
680 | * | |
c6480207 | 681 | */ |
5b52330b PM |
682 | static int kauditd_send_queue(struct sock *sk, u32 portid, |
683 | struct sk_buff_head *queue, | |
684 | unsigned int retry_limit, | |
685 | void (*skb_hook)(struct sk_buff *skb), | |
686 | void (*err_hook)(struct sk_buff *skb)) | |
c6480207 | 687 | { |
5b52330b PM |
688 | int rc = 0; |
689 | struct sk_buff *skb; | |
690 | static unsigned int failed = 0; | |
32a1dbae | 691 | |
5b52330b PM |
692 | /* NOTE: kauditd_thread takes care of all our locking, we just use |
693 | * the netlink info passed to us (e.g. sk and portid) */ | |
694 | ||
695 | while ((skb = skb_dequeue(queue))) { | |
696 | /* call the skb_hook for each skb we touch */ | |
697 | if (skb_hook) | |
698 | (*skb_hook)(skb); | |
699 | ||
700 | /* can we send to anyone via unicast? */ | |
701 | if (!sk) { | |
702 | if (err_hook) | |
703 | (*err_hook)(skb); | |
704 | continue; | |
705 | } | |
6c54e789 | 706 | |
5b52330b PM |
707 | /* grab an extra skb reference in case of error */ |
708 | skb_get(skb); | |
709 | rc = netlink_unicast(sk, skb, portid, 0); | |
710 | if (rc < 0) { | |
711 | /* fatal failure for our queue flush attempt? */ | |
712 | if (++failed >= retry_limit || | |
713 | rc == -ECONNREFUSED || rc == -EPERM) { | |
714 | /* yes - error processing for the queue */ | |
715 | sk = NULL; | |
716 | if (err_hook) | |
717 | (*err_hook)(skb); | |
718 | if (!skb_hook) | |
719 | goto out; | |
720 | /* keep processing with the skb_hook */ | |
721 | continue; | |
722 | } else | |
723 | /* no - requeue to preserve ordering */ | |
724 | skb_queue_head(queue, skb); | |
725 | } else { | |
726 | /* it worked - drop the extra reference and continue */ | |
727 | consume_skb(skb); | |
728 | failed = 0; | |
729 | } | |
c6480207 PM |
730 | } |
731 | ||
5b52330b PM |
732 | out: |
733 | return (rc >= 0 ? 0 : rc); | |
f3d357b0 EP |
734 | } |
735 | ||
451f9216 | 736 | /* |
c6480207 PM |
737 | * kauditd_send_multicast_skb - Send a record to any multicast listeners |
738 | * @skb: audit record | |
451f9216 | 739 | * |
c6480207 | 740 | * Description: |
5b52330b PM |
741 | * Write a multicast message to anyone listening in the initial network |
742 | * namespace. This function doesn't consume an skb as might be expected since | |
743 | * it has to copy it anyways. | |
451f9216 | 744 | */ |
c6480207 | 745 | static void kauditd_send_multicast_skb(struct sk_buff *skb) |
451f9216 | 746 | { |
c6480207 | 747 | struct sk_buff *copy; |
5b52330b | 748 | struct sock *sock = audit_get_sk(&init_net); |
c6480207 | 749 | struct nlmsghdr *nlh; |
451f9216 | 750 | |
5b52330b PM |
751 | /* NOTE: we are not taking an additional reference for init_net since |
752 | * we don't have to worry about it going away */ | |
753 | ||
7f74ecd7 RGB |
754 | if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG)) |
755 | return; | |
756 | ||
451f9216 RGB |
757 | /* |
758 | * The seemingly wasteful skb_copy() rather than bumping the refcount | |
759 | * using skb_get() is necessary because non-standard mods are made to | |
760 | * the skb by the original kaudit unicast socket send routine. The | |
761 | * existing auditd daemon assumes this breakage. Fixing this would | |
762 | * require co-ordinating a change in the established protocol between | |
763 | * the kaudit kernel subsystem and the auditd userspace code. There is | |
764 | * no reason for new multicast clients to continue with this | |
765 | * non-compliance. | |
766 | */ | |
c6480207 | 767 | copy = skb_copy(skb, GFP_KERNEL); |
451f9216 RGB |
768 | if (!copy) |
769 | return; | |
c6480207 PM |
770 | nlh = nlmsg_hdr(copy); |
771 | nlh->nlmsg_len = skb->len; | |
451f9216 | 772 | |
c6480207 | 773 | nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL); |
451f9216 RGB |
774 | } |
775 | ||
c6480207 | 776 | /** |
5b52330b PM |
777 | * kauditd_thread - Worker thread to send audit records to userspace |
778 | * @dummy: unused | |
b551d1d9 | 779 | */ |
97a41e26 | 780 | static int kauditd_thread(void *dummy) |
b7d11258 | 781 | { |
c6480207 | 782 | int rc; |
5b52330b PM |
783 | u32 portid = 0; |
784 | struct net *net = NULL; | |
785 | struct sock *sk = NULL; | |
48d0e023 | 786 | struct auditd_connection *ac; |
4aa83872 | 787 | |
c6480207 | 788 | #define UNICAST_RETRIES 5 |
c6480207 | 789 | |
83144186 | 790 | set_freezable(); |
4899b8b1 | 791 | while (!kthread_should_stop()) { |
5b52330b PM |
792 | /* NOTE: see the lock comments in auditd_send_unicast_skb() */ |
793 | rcu_read_lock(); | |
48d0e023 PM |
794 | ac = rcu_dereference(auditd_conn); |
795 | if (!ac) { | |
5b52330b PM |
796 | rcu_read_unlock(); |
797 | goto main_queue; | |
798 | } | |
48d0e023 | 799 | net = get_net(ac->net); |
5b52330b | 800 | sk = audit_get_sk(net); |
48d0e023 | 801 | portid = ac->portid; |
5b52330b | 802 | rcu_read_unlock(); |
c6480207 PM |
803 | |
804 | /* attempt to flush the hold queue */ | |
5b52330b PM |
805 | rc = kauditd_send_queue(sk, portid, |
806 | &audit_hold_queue, UNICAST_RETRIES, | |
807 | NULL, kauditd_rehold_skb); | |
c81be52a | 808 | if (ac && rc < 0) { |
5b52330b | 809 | sk = NULL; |
c81be52a | 810 | auditd_reset(ac); |
5b52330b | 811 | goto main_queue; |
c6480207 | 812 | } |
f3d357b0 | 813 | |
c6480207 | 814 | /* attempt to flush the retry queue */ |
5b52330b PM |
815 | rc = kauditd_send_queue(sk, portid, |
816 | &audit_retry_queue, UNICAST_RETRIES, | |
817 | NULL, kauditd_hold_skb); | |
c81be52a | 818 | if (ac && rc < 0) { |
5b52330b | 819 | sk = NULL; |
c81be52a | 820 | auditd_reset(ac); |
5b52330b | 821 | goto main_queue; |
c6480207 | 822 | } |
db897319 | 823 | |
5b52330b PM |
824 | main_queue: |
825 | /* process the main queue - do the multicast send and attempt | |
826 | * unicast, dump failed record sends to the retry queue; if | |
827 | * sk == NULL due to previous failures we will just do the | |
c81be52a | 828 | * multicast send and move the record to the hold queue */ |
264d5096 PM |
829 | rc = kauditd_send_queue(sk, portid, &audit_queue, 1, |
830 | kauditd_send_multicast_skb, | |
c81be52a PM |
831 | (sk ? |
832 | kauditd_retry_skb : kauditd_hold_skb)); | |
833 | if (ac && rc < 0) | |
834 | auditd_reset(ac); | |
264d5096 | 835 | sk = NULL; |
5b52330b PM |
836 | |
837 | /* drop our netns reference, no auditd sends past this line */ | |
838 | if (net) { | |
839 | put_net(net); | |
840 | net = NULL; | |
3320c513 | 841 | } |
5b52330b PM |
842 | |
843 | /* we have processed all the queues so wake everyone */ | |
844 | wake_up(&audit_backlog_wait); | |
845 | ||
846 | /* NOTE: we want to wake up if there is anything on the queue, | |
847 | * regardless of if an auditd is connected, as we need to | |
848 | * do the multicast send and rotate records from the | |
849 | * main queue to the retry/hold queues */ | |
850 | wait_event_freezable(kauditd_wait, | |
851 | (skb_queue_len(&audit_queue) ? 1 : 0)); | |
b7d11258 | 852 | } |
c6480207 | 853 | |
4899b8b1 | 854 | return 0; |
b7d11258 DW |
855 | } |
856 | ||
9044e6bc AV |
857 | int audit_send_list(void *_dest) |
858 | { | |
859 | struct audit_netlink_list *dest = _dest; | |
9044e6bc | 860 | struct sk_buff *skb; |
5b52330b | 861 | struct sock *sk = audit_get_sk(dest->net); |
9044e6bc AV |
862 | |
863 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
864 | mutex_lock(&audit_cmd_mutex); |
865 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
866 | |
867 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
5b52330b | 868 | netlink_unicast(sk, skb, dest->portid, 0); |
9044e6bc | 869 | |
5b52330b | 870 | put_net(dest->net); |
9044e6bc AV |
871 | kfree(dest); |
872 | ||
873 | return 0; | |
874 | } | |
875 | ||
45a0642b | 876 | struct sk_buff *audit_make_reply(int seq, int type, int done, |
b8800aa5 | 877 | int multi, const void *payload, int size) |
9044e6bc AV |
878 | { |
879 | struct sk_buff *skb; | |
880 | struct nlmsghdr *nlh; | |
9044e6bc AV |
881 | void *data; |
882 | int flags = multi ? NLM_F_MULTI : 0; | |
883 | int t = done ? NLMSG_DONE : type; | |
884 | ||
ee080e6c | 885 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
886 | if (!skb) |
887 | return NULL; | |
888 | ||
45a0642b | 889 | nlh = nlmsg_put(skb, 0, seq, t, size, flags); |
c64e66c6 DM |
890 | if (!nlh) |
891 | goto out_kfree_skb; | |
892 | data = nlmsg_data(nlh); | |
9044e6bc AV |
893 | memcpy(data, payload, size); |
894 | return skb; | |
895 | ||
c64e66c6 DM |
896 | out_kfree_skb: |
897 | kfree_skb(skb); | |
9044e6bc AV |
898 | return NULL; |
899 | } | |
900 | ||
f09ac9db EP |
901 | static int audit_send_reply_thread(void *arg) |
902 | { | |
903 | struct audit_reply *reply = (struct audit_reply *)arg; | |
5b52330b | 904 | struct sock *sk = audit_get_sk(reply->net); |
f09ac9db EP |
905 | |
906 | mutex_lock(&audit_cmd_mutex); | |
907 | mutex_unlock(&audit_cmd_mutex); | |
908 | ||
909 | /* Ignore failure. It'll only happen if the sender goes away, | |
910 | because our timeout is set to infinite. */ | |
5b52330b PM |
911 | netlink_unicast(sk, reply->skb, reply->portid, 0); |
912 | put_net(reply->net); | |
f09ac9db EP |
913 | kfree(reply); |
914 | return 0; | |
915 | } | |
c6480207 | 916 | |
b0dd25a8 RD |
917 | /** |
918 | * audit_send_reply - send an audit reply message via netlink | |
d211f177 | 919 | * @request_skb: skb of request we are replying to (used to target the reply) |
b0dd25a8 RD |
920 | * @seq: sequence number |
921 | * @type: audit message type | |
922 | * @done: done (last) flag | |
923 | * @multi: multi-part message flag | |
924 | * @payload: payload data | |
925 | * @size: payload size | |
926 | * | |
f9441639 | 927 | * Allocates an skb, builds the netlink message, and sends it to the port id. |
b0dd25a8 RD |
928 | * No failure notifications. |
929 | */ | |
6f285b19 | 930 | static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done, |
f9441639 | 931 | int multi, const void *payload, int size) |
1da177e4 | 932 | { |
6f285b19 | 933 | struct net *net = sock_net(NETLINK_CB(request_skb).sk); |
f09ac9db EP |
934 | struct sk_buff *skb; |
935 | struct task_struct *tsk; | |
936 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
937 | GFP_KERNEL); | |
938 | ||
939 | if (!reply) | |
940 | return; | |
941 | ||
45a0642b | 942 | skb = audit_make_reply(seq, type, done, multi, payload, size); |
1da177e4 | 943 | if (!skb) |
fcaf1eb8 | 944 | goto out; |
f09ac9db | 945 | |
6f285b19 | 946 | reply->net = get_net(net); |
45a0642b | 947 | reply->portid = NETLINK_CB(request_skb).portid; |
f09ac9db EP |
948 | reply->skb = skb; |
949 | ||
950 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
951 | if (!IS_ERR(tsk)) |
952 | return; | |
953 | kfree_skb(skb); | |
954 | out: | |
955 | kfree(reply); | |
1da177e4 LT |
956 | } |
957 | ||
958 | /* | |
959 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
960 | * control messages. | |
961 | */ | |
c7bdb545 | 962 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
963 | { |
964 | int err = 0; | |
965 | ||
5a3cb3b6 | 966 | /* Only support initial user namespace for now. */ |
aa4af831 EP |
967 | /* |
968 | * We return ECONNREFUSED because it tricks userspace into thinking | |
969 | * that audit was not configured into the kernel. Lots of users | |
970 | * configure their PAM stack (because that's what the distro does) | |
971 | * to reject login if unable to send messages to audit. If we return | |
972 | * ECONNREFUSED the PAM stack thinks the kernel does not have audit | |
973 | * configured in and will let login proceed. If we return EPERM | |
974 | * userspace will reject all logins. This should be removed when we | |
975 | * support non init namespaces!! | |
976 | */ | |
0b747172 | 977 | if (current_user_ns() != &init_user_ns) |
aa4af831 | 978 | return -ECONNREFUSED; |
34e36d8e | 979 | |
1da177e4 | 980 | switch (msg_type) { |
1da177e4 | 981 | case AUDIT_LIST: |
1da177e4 LT |
982 | case AUDIT_ADD: |
983 | case AUDIT_DEL: | |
18900909 EP |
984 | return -EOPNOTSUPP; |
985 | case AUDIT_GET: | |
986 | case AUDIT_SET: | |
b0fed402 EP |
987 | case AUDIT_GET_FEATURE: |
988 | case AUDIT_SET_FEATURE: | |
18900909 EP |
989 | case AUDIT_LIST_RULES: |
990 | case AUDIT_ADD_RULE: | |
93315ed6 | 991 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 992 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
993 | case AUDIT_TTY_GET: |
994 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
995 | case AUDIT_TRIM: |
996 | case AUDIT_MAKE_EQUIV: | |
5a3cb3b6 RGB |
997 | /* Only support auditd and auditctl in initial pid namespace |
998 | * for now. */ | |
5985de67 | 999 | if (task_active_pid_ns(current) != &init_pid_ns) |
5a3cb3b6 RGB |
1000 | return -EPERM; |
1001 | ||
90f62cf3 | 1002 | if (!netlink_capable(skb, CAP_AUDIT_CONTROL)) |
1da177e4 LT |
1003 | err = -EPERM; |
1004 | break; | |
05474106 | 1005 | case AUDIT_USER: |
039b6b3e RD |
1006 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
1007 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
90f62cf3 | 1008 | if (!netlink_capable(skb, CAP_AUDIT_WRITE)) |
1da177e4 LT |
1009 | err = -EPERM; |
1010 | break; | |
1011 | default: /* bad msg */ | |
1012 | err = -EINVAL; | |
1013 | } | |
1014 | ||
1015 | return err; | |
1016 | } | |
1017 | ||
233a6866 | 1018 | static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 | 1019 | { |
dc9eb698 | 1020 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
f1dc4867 | 1021 | pid_t pid = task_tgid_nr(current); |
50397bd1 | 1022 | |
0868a5e1 | 1023 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 | 1024 | *ab = NULL; |
233a6866 | 1025 | return; |
50397bd1 EP |
1026 | } |
1027 | ||
1028 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c | 1029 | if (unlikely(!*ab)) |
233a6866 | 1030 | return; |
f1dc4867 | 1031 | audit_log_format(*ab, "pid=%d uid=%u", pid, uid); |
4d3fb709 | 1032 | audit_log_session_info(*ab); |
b122c376 | 1033 | audit_log_task_context(*ab); |
50397bd1 EP |
1034 | } |
1035 | ||
b0fed402 EP |
1036 | int is_audit_feature_set(int i) |
1037 | { | |
1038 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
1039 | } | |
1040 | ||
1041 | ||
1042 | static int audit_get_feature(struct sk_buff *skb) | |
1043 | { | |
1044 | u32 seq; | |
1045 | ||
1046 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
1047 | ||
9ef91514 | 1048 | audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af)); |
b0fed402 EP |
1049 | |
1050 | return 0; | |
1051 | } | |
1052 | ||
1053 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
1054 | u32 old_lock, u32 new_lock, int res) | |
1055 | { | |
1056 | struct audit_buffer *ab; | |
1057 | ||
b6c50fe0 G |
1058 | if (audit_enabled == AUDIT_OFF) |
1059 | return; | |
1060 | ||
b0fed402 | 1061 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); |
ad2ac263 | 1062 | audit_log_task_info(ab, current); |
897f1acb | 1063 | audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d", |
b0fed402 EP |
1064 | audit_feature_names[which], !!old_feature, !!new_feature, |
1065 | !!old_lock, !!new_lock, res); | |
1066 | audit_log_end(ab); | |
1067 | } | |
1068 | ||
1069 | static int audit_set_feature(struct sk_buff *skb) | |
1070 | { | |
1071 | struct audit_features *uaf; | |
1072 | int i; | |
1073 | ||
6eed9b26 | 1074 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names)); |
b0fed402 EP |
1075 | uaf = nlmsg_data(nlmsg_hdr(skb)); |
1076 | ||
1077 | /* if there is ever a version 2 we should handle that here */ | |
1078 | ||
1079 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
1080 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
1081 | u32 old_feature, new_feature, old_lock, new_lock; | |
1082 | ||
1083 | /* if we are not changing this feature, move along */ | |
1084 | if (!(feature & uaf->mask)) | |
1085 | continue; | |
1086 | ||
1087 | old_feature = af.features & feature; | |
1088 | new_feature = uaf->features & feature; | |
1089 | new_lock = (uaf->lock | af.lock) & feature; | |
1090 | old_lock = af.lock & feature; | |
1091 | ||
1092 | /* are we changing a locked feature? */ | |
4547b3bc | 1093 | if (old_lock && (new_feature != old_feature)) { |
b0fed402 EP |
1094 | audit_log_feature_change(i, old_feature, new_feature, |
1095 | old_lock, new_lock, 0); | |
1096 | return -EPERM; | |
1097 | } | |
1098 | } | |
1099 | /* nothing invalid, do the changes */ | |
1100 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
1101 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
1102 | u32 old_feature, new_feature, old_lock, new_lock; | |
1103 | ||
1104 | /* if we are not changing this feature, move along */ | |
1105 | if (!(feature & uaf->mask)) | |
1106 | continue; | |
1107 | ||
1108 | old_feature = af.features & feature; | |
1109 | new_feature = uaf->features & feature; | |
1110 | old_lock = af.lock & feature; | |
1111 | new_lock = (uaf->lock | af.lock) & feature; | |
1112 | ||
1113 | if (new_feature != old_feature) | |
1114 | audit_log_feature_change(i, old_feature, new_feature, | |
1115 | old_lock, new_lock, 1); | |
1116 | ||
1117 | if (new_feature) | |
1118 | af.features |= feature; | |
1119 | else | |
1120 | af.features &= ~feature; | |
1121 | af.lock |= new_lock; | |
1122 | } | |
1123 | ||
1124 | return 0; | |
1125 | } | |
1126 | ||
b6c7c115 | 1127 | static int audit_replace(struct pid *pid) |
133e1e5a | 1128 | { |
b6c7c115 | 1129 | pid_t pvnr; |
5b52330b | 1130 | struct sk_buff *skb; |
133e1e5a | 1131 | |
b6c7c115 PM |
1132 | pvnr = pid_vnr(pid); |
1133 | skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr)); | |
133e1e5a RGB |
1134 | if (!skb) |
1135 | return -ENOMEM; | |
5b52330b | 1136 | return auditd_send_unicast_skb(skb); |
133e1e5a RGB |
1137 | } |
1138 | ||
1da177e4 LT |
1139 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
1140 | { | |
dc9eb698 | 1141 | u32 seq; |
1da177e4 | 1142 | void *data; |
1da177e4 | 1143 | int err; |
c0404993 | 1144 | struct audit_buffer *ab; |
1da177e4 | 1145 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 1146 | struct audit_sig_info *sig_data; |
50397bd1 | 1147 | char *ctx = NULL; |
e1396065 | 1148 | u32 len; |
1da177e4 | 1149 | |
c7bdb545 | 1150 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
1151 | if (err) |
1152 | return err; | |
1153 | ||
1da177e4 | 1154 | seq = nlh->nlmsg_seq; |
c64e66c6 | 1155 | data = nlmsg_data(nlh); |
1da177e4 LT |
1156 | |
1157 | switch (msg_type) { | |
09f883a9 RGB |
1158 | case AUDIT_GET: { |
1159 | struct audit_status s; | |
1160 | memset(&s, 0, sizeof(s)); | |
1161 | s.enabled = audit_enabled; | |
1162 | s.failure = audit_failure; | |
b6c7c115 PM |
1163 | /* NOTE: use pid_vnr() so the PID is relative to the current |
1164 | * namespace */ | |
48d0e023 | 1165 | s.pid = auditd_pid_vnr(); |
09f883a9 RGB |
1166 | s.rate_limit = audit_rate_limit; |
1167 | s.backlog_limit = audit_backlog_limit; | |
1168 | s.lost = atomic_read(&audit_lost); | |
af8b824f | 1169 | s.backlog = skb_queue_len(&audit_queue); |
0288d718 | 1170 | s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL; |
31975424 | 1171 | s.backlog_wait_time = audit_backlog_wait_time; |
6f285b19 | 1172 | audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s)); |
1da177e4 | 1173 | break; |
09f883a9 RGB |
1174 | } |
1175 | case AUDIT_SET: { | |
1176 | struct audit_status s; | |
1177 | memset(&s, 0, sizeof(s)); | |
1178 | /* guard against past and future API changes */ | |
1179 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
1180 | if (s.mask & AUDIT_STATUS_ENABLED) { | |
1181 | err = audit_set_enabled(s.enabled); | |
20c6aaa3 | 1182 | if (err < 0) |
1183 | return err; | |
1da177e4 | 1184 | } |
09f883a9 RGB |
1185 | if (s.mask & AUDIT_STATUS_FAILURE) { |
1186 | err = audit_set_failure(s.failure); | |
20c6aaa3 | 1187 | if (err < 0) |
1188 | return err; | |
1da177e4 | 1189 | } |
09f883a9 | 1190 | if (s.mask & AUDIT_STATUS_PID) { |
b6c7c115 PM |
1191 | /* NOTE: we are using the vnr PID functions below |
1192 | * because the s.pid value is relative to the | |
1193 | * namespace of the caller; at present this | |
1194 | * doesn't matter much since you can really only | |
1195 | * run auditd from the initial pid namespace, but | |
1196 | * something to keep in mind if this changes */ | |
1197 | pid_t new_pid = s.pid; | |
5b52330b | 1198 | pid_t auditd_pid; |
b6c7c115 PM |
1199 | struct pid *req_pid = task_tgid(current); |
1200 | ||
33e8a907 SG |
1201 | /* Sanity check - PID values must match. Setting |
1202 | * pid to 0 is how auditd ends auditing. */ | |
1203 | if (new_pid && (new_pid != pid_vnr(req_pid))) | |
b6c7c115 | 1204 | return -EINVAL; |
1a6b9f23 | 1205 | |
5b52330b | 1206 | /* test the auditd connection */ |
b6c7c115 | 1207 | audit_replace(req_pid); |
5b52330b | 1208 | |
48d0e023 | 1209 | auditd_pid = auditd_pid_vnr(); |
33e8a907 SG |
1210 | if (auditd_pid) { |
1211 | /* replacing a healthy auditd is not allowed */ | |
1212 | if (new_pid) { | |
1213 | audit_log_config_change("audit_pid", | |
1214 | new_pid, auditd_pid, 0); | |
1215 | return -EEXIST; | |
1216 | } | |
1217 | /* only current auditd can unregister itself */ | |
1218 | if (pid_vnr(req_pid) != auditd_pid) { | |
1219 | audit_log_config_change("audit_pid", | |
1220 | new_pid, auditd_pid, 0); | |
1221 | return -EACCES; | |
1222 | } | |
935c9e7f | 1223 | } |
5b52330b | 1224 | |
533c7b69 | 1225 | if (new_pid) { |
5b52330b | 1226 | /* register a new auditd connection */ |
48d0e023 PM |
1227 | err = auditd_set(req_pid, |
1228 | NETLINK_CB(skb).portid, | |
1229 | sock_net(NETLINK_CB(skb).sk)); | |
1230 | if (audit_enabled != AUDIT_OFF) | |
1231 | audit_log_config_change("audit_pid", | |
1232 | new_pid, | |
1233 | auditd_pid, | |
1234 | err ? 0 : 1); | |
1235 | if (err) | |
1236 | return err; | |
1237 | ||
5b52330b PM |
1238 | /* try to process any backlog */ |
1239 | wake_up_interruptible(&kauditd_wait); | |
48d0e023 PM |
1240 | } else { |
1241 | if (audit_enabled != AUDIT_OFF) | |
1242 | audit_log_config_change("audit_pid", | |
1243 | new_pid, | |
1244 | auditd_pid, 1); | |
1245 | ||
5b52330b | 1246 | /* unregister the auditd connection */ |
c81be52a | 1247 | auditd_reset(NULL); |
48d0e023 | 1248 | } |
1da177e4 | 1249 | } |
09f883a9 RGB |
1250 | if (s.mask & AUDIT_STATUS_RATE_LIMIT) { |
1251 | err = audit_set_rate_limit(s.rate_limit); | |
20c6aaa3 | 1252 | if (err < 0) |
1253 | return err; | |
1254 | } | |
51cc83f0 | 1255 | if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) { |
09f883a9 | 1256 | err = audit_set_backlog_limit(s.backlog_limit); |
51cc83f0 RGB |
1257 | if (err < 0) |
1258 | return err; | |
1259 | } | |
3f0c5fad EP |
1260 | if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) { |
1261 | if (sizeof(s) > (size_t)nlh->nlmsg_len) | |
1262 | return -EINVAL; | |
724e7bfc | 1263 | if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME) |
3f0c5fad EP |
1264 | return -EINVAL; |
1265 | err = audit_set_backlog_wait_time(s.backlog_wait_time); | |
1266 | if (err < 0) | |
1267 | return err; | |
51cc83f0 | 1268 | } |
92c82e8a RGB |
1269 | if (s.mask == AUDIT_STATUS_LOST) { |
1270 | u32 lost = atomic_xchg(&audit_lost, 0); | |
1271 | ||
1272 | audit_log_config_change("lost", 0, lost, 1); | |
1273 | return lost; | |
1274 | } | |
1da177e4 | 1275 | break; |
09f883a9 | 1276 | } |
b0fed402 EP |
1277 | case AUDIT_GET_FEATURE: |
1278 | err = audit_get_feature(skb); | |
1279 | if (err) | |
1280 | return err; | |
1281 | break; | |
1282 | case AUDIT_SET_FEATURE: | |
1283 | err = audit_set_feature(skb); | |
1284 | if (err) | |
1285 | return err; | |
1286 | break; | |
05474106 | 1287 | case AUDIT_USER: |
039b6b3e RD |
1288 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
1289 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
1290 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
1291 | return 0; | |
1292 | ||
86b2efbe | 1293 | err = audit_filter(msg_type, AUDIT_FILTER_USER); |
724e4fcc | 1294 | if (err == 1) { /* match or error */ |
4a4cd633 | 1295 | err = 0; |
522ed776 | 1296 | if (msg_type == AUDIT_USER_TTY) { |
37282a77 | 1297 | err = tty_audit_push(); |
522ed776 MT |
1298 | if (err) |
1299 | break; | |
1300 | } | |
dc9eb698 | 1301 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 1302 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
1303 | audit_log_format(ab, " msg='%.*s'", |
1304 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
1305 | (char *)data); |
1306 | else { | |
1307 | int size; | |
1308 | ||
f7616102 | 1309 | audit_log_format(ab, " data="); |
50397bd1 | 1310 | size = nlmsg_len(nlh); |
55ad2f8d MT |
1311 | if (size > 0 && |
1312 | ((unsigned char *)data)[size - 1] == '\0') | |
1313 | size--; | |
b556f8ad | 1314 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 1315 | } |
50397bd1 | 1316 | audit_log_end(ab); |
0f45aa18 | 1317 | } |
1da177e4 | 1318 | break; |
93315ed6 AG |
1319 | case AUDIT_ADD_RULE: |
1320 | case AUDIT_DEL_RULE: | |
1321 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
1322 | return -EINVAL; | |
1a6b9f23 | 1323 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
1324 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
1325 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 1326 | audit_log_end(ab); |
6a01b07f SG |
1327 | return -EPERM; |
1328 | } | |
45a0642b | 1329 | err = audit_rule_change(msg_type, seq, data, nlmsg_len(nlh)); |
1da177e4 | 1330 | break; |
ce0d9f04 | 1331 | case AUDIT_LIST_RULES: |
6f285b19 | 1332 | err = audit_list_rules_send(skb, seq); |
ce0d9f04 | 1333 | break; |
74c3cbe3 AV |
1334 | case AUDIT_TRIM: |
1335 | audit_trim_trees(); | |
dc9eb698 | 1336 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
1337 | audit_log_format(ab, " op=trim res=1"); |
1338 | audit_log_end(ab); | |
1339 | break; | |
1340 | case AUDIT_MAKE_EQUIV: { | |
1341 | void *bufp = data; | |
1342 | u32 sizes[2]; | |
7719e437 | 1343 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
1344 | char *old, *new; |
1345 | ||
1346 | err = -EINVAL; | |
7719e437 | 1347 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
1348 | break; |
1349 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
1350 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
1351 | msglen -= 2 * sizeof(u32); |
1352 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
1353 | if (IS_ERR(old)) { |
1354 | err = PTR_ERR(old); | |
1355 | break; | |
1356 | } | |
7719e437 | 1357 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
1358 | if (IS_ERR(new)) { |
1359 | err = PTR_ERR(new); | |
1360 | kfree(old); | |
1361 | break; | |
1362 | } | |
1363 | /* OK, here comes... */ | |
1364 | err = audit_tag_tree(old, new); | |
1365 | ||
dc9eb698 | 1366 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 1367 | |
74c3cbe3 AV |
1368 | audit_log_format(ab, " op=make_equiv old="); |
1369 | audit_log_untrustedstring(ab, old); | |
1370 | audit_log_format(ab, " new="); | |
1371 | audit_log_untrustedstring(ab, new); | |
1372 | audit_log_format(ab, " res=%d", !err); | |
1373 | audit_log_end(ab); | |
1374 | kfree(old); | |
1375 | kfree(new); | |
1376 | break; | |
1377 | } | |
c2f0c7c3 | 1378 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
1379 | len = 0; |
1380 | if (audit_sig_sid) { | |
1381 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
1382 | if (err) | |
1383 | return err; | |
1384 | } | |
e1396065 AV |
1385 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
1386 | if (!sig_data) { | |
939cbf26 EP |
1387 | if (audit_sig_sid) |
1388 | security_release_secctx(ctx, len); | |
e1396065 AV |
1389 | return -ENOMEM; |
1390 | } | |
cca080d9 | 1391 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 1392 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
1393 | if (audit_sig_sid) { |
1394 | memcpy(sig_data->ctx, ctx, len); | |
1395 | security_release_secctx(ctx, len); | |
1396 | } | |
6f285b19 EB |
1397 | audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, |
1398 | sig_data, sizeof(*sig_data) + len); | |
e1396065 | 1399 | kfree(sig_data); |
c2f0c7c3 | 1400 | break; |
522ed776 MT |
1401 | case AUDIT_TTY_GET: { |
1402 | struct audit_tty_status s; | |
2e28d38a | 1403 | unsigned int t; |
8aa14b64 | 1404 | |
2e28d38a PH |
1405 | t = READ_ONCE(current->signal->audit_tty); |
1406 | s.enabled = t & AUDIT_TTY_ENABLE; | |
1407 | s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD); | |
8aa14b64 | 1408 | |
6f285b19 | 1409 | audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
1410 | break; |
1411 | } | |
1412 | case AUDIT_TTY_SET: { | |
a06e56b2 | 1413 | struct audit_tty_status s, old; |
a06e56b2 | 1414 | struct audit_buffer *ab; |
2e28d38a | 1415 | unsigned int t; |
0e23bacc EP |
1416 | |
1417 | memset(&s, 0, sizeof(s)); | |
1418 | /* guard against past and future API changes */ | |
1419 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
1420 | /* check if new data is valid */ | |
1421 | if ((s.enabled != 0 && s.enabled != 1) || | |
1422 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
1423 | err = -EINVAL; | |
a06e56b2 | 1424 | |
2e28d38a PH |
1425 | if (err) |
1426 | t = READ_ONCE(current->signal->audit_tty); | |
1427 | else { | |
1428 | t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD); | |
1429 | t = xchg(¤t->signal->audit_tty, t); | |
0e23bacc | 1430 | } |
2e28d38a PH |
1431 | old.enabled = t & AUDIT_TTY_ENABLE; |
1432 | old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD); | |
522ed776 | 1433 | |
a06e56b2 | 1434 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
1ce319f1 EP |
1435 | audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d" |
1436 | " old-log_passwd=%d new-log_passwd=%d res=%d", | |
1437 | old.enabled, s.enabled, old.log_passwd, | |
1438 | s.log_passwd, !err); | |
a06e56b2 | 1439 | audit_log_end(ab); |
522ed776 MT |
1440 | break; |
1441 | } | |
1da177e4 LT |
1442 | default: |
1443 | err = -EINVAL; | |
1444 | break; | |
1445 | } | |
1446 | ||
1447 | return err < 0 ? err : 0; | |
1448 | } | |
1449 | ||
a9d16208 PM |
1450 | /** |
1451 | * audit_receive - receive messages from a netlink control socket | |
1452 | * @skb: the message buffer | |
1453 | * | |
1454 | * Parse the provided skb and deal with any messages that may be present, | |
1455 | * malformed skbs are discarded. | |
b0dd25a8 | 1456 | */ |
a9d16208 | 1457 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 1458 | { |
ea7ae60b EP |
1459 | struct nlmsghdr *nlh; |
1460 | /* | |
94191213 | 1461 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
1462 | * if the nlmsg_len was not aligned |
1463 | */ | |
1464 | int len; | |
1465 | int err; | |
1466 | ||
1467 | nlh = nlmsg_hdr(skb); | |
1468 | len = skb->len; | |
1469 | ||
a9d16208 | 1470 | mutex_lock(&audit_cmd_mutex); |
94191213 | 1471 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
1472 | err = audit_receive_msg(skb, nlh); |
1473 | /* if err or if this message says it wants a response */ | |
1474 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
2d4bc933 | 1475 | netlink_ack(skb, nlh, err, NULL); |
ea7ae60b | 1476 | |
2851da57 | 1477 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 1478 | } |
f368c07d | 1479 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
1480 | } |
1481 | ||
3a101b8d | 1482 | /* Run custom bind function on netlink socket group connect or bind requests. */ |
023e2cfa | 1483 | static int audit_bind(struct net *net, int group) |
3a101b8d RGB |
1484 | { |
1485 | if (!capable(CAP_AUDIT_READ)) | |
1486 | return -EPERM; | |
1487 | ||
1488 | return 0; | |
1489 | } | |
1490 | ||
33faba7f | 1491 | static int __net_init audit_net_init(struct net *net) |
1da177e4 | 1492 | { |
a31f2d17 PNA |
1493 | struct netlink_kernel_cfg cfg = { |
1494 | .input = audit_receive, | |
3a101b8d | 1495 | .bind = audit_bind, |
451f9216 RGB |
1496 | .flags = NL_CFG_F_NONROOT_RECV, |
1497 | .groups = AUDIT_NLGRP_MAX, | |
a31f2d17 | 1498 | }; |
f368c07d | 1499 | |
33faba7f RGB |
1500 | struct audit_net *aunet = net_generic(net, audit_net_id); |
1501 | ||
5b52330b PM |
1502 | aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); |
1503 | if (aunet->sk == NULL) { | |
33faba7f | 1504 | audit_panic("cannot initialize netlink socket in namespace"); |
11ee39eb G |
1505 | return -ENOMEM; |
1506 | } | |
5b52330b PM |
1507 | aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; |
1508 | ||
33faba7f RGB |
1509 | return 0; |
1510 | } | |
1511 | ||
1512 | static void __net_exit audit_net_exit(struct net *net) | |
1513 | { | |
1514 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
5b52330b | 1515 | |
48d0e023 PM |
1516 | /* NOTE: you would think that we would want to check the auditd |
1517 | * connection and potentially reset it here if it lives in this | |
1518 | * namespace, but since the auditd connection tracking struct holds a | |
1519 | * reference to this namespace (see auditd_set()) we are only ever | |
1520 | * going to get here after that connection has been released */ | |
33faba7f | 1521 | |
5b52330b | 1522 | netlink_kernel_release(aunet->sk); |
33faba7f RGB |
1523 | } |
1524 | ||
8626877b | 1525 | static struct pernet_operations audit_net_ops __net_initdata = { |
33faba7f RGB |
1526 | .init = audit_net_init, |
1527 | .exit = audit_net_exit, | |
1528 | .id = &audit_net_id, | |
1529 | .size = sizeof(struct audit_net), | |
1530 | }; | |
1531 | ||
1532 | /* Initialize audit support at boot time. */ | |
1533 | static int __init audit_init(void) | |
1534 | { | |
1535 | int i; | |
1536 | ||
a3f07114 EP |
1537 | if (audit_initialized == AUDIT_DISABLED) |
1538 | return 0; | |
1539 | ||
8cc96382 PM |
1540 | audit_buffer_cache = kmem_cache_create("audit_buffer", |
1541 | sizeof(struct audit_buffer), | |
1542 | 0, SLAB_PANIC, NULL); | |
1da177e4 | 1543 | |
af8b824f | 1544 | skb_queue_head_init(&audit_queue); |
c6480207 | 1545 | skb_queue_head_init(&audit_retry_queue); |
af8b824f | 1546 | skb_queue_head_init(&audit_hold_queue); |
3dc7e315 | 1547 | |
f368c07d AG |
1548 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1549 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1550 | |
5b52330b PM |
1551 | pr_info("initializing netlink subsys (%s)\n", |
1552 | audit_default ? "enabled" : "disabled"); | |
1553 | register_pernet_subsys(&audit_net_ops); | |
1554 | ||
1555 | audit_initialized = AUDIT_INITIALIZED; | |
5b52330b | 1556 | |
6c925564 PM |
1557 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
1558 | if (IS_ERR(kauditd_task)) { | |
1559 | int err = PTR_ERR(kauditd_task); | |
1560 | panic("audit: failed to start the kauditd thread (%d)\n", err); | |
1561 | } | |
1562 | ||
7c397d01 SG |
1563 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, |
1564 | "state=initialized audit_enabled=%u res=1", | |
1565 | audit_enabled); | |
6c925564 | 1566 | |
1da177e4 LT |
1567 | return 0; |
1568 | } | |
be4104ab | 1569 | postcore_initcall(audit_init); |
1da177e4 LT |
1570 | |
1571 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1572 | static int __init audit_enable(char *str) | |
1573 | { | |
80ab4df6 PM |
1574 | long val; |
1575 | ||
1576 | if (kstrtol(str, 0, &val)) | |
1577 | panic("audit: invalid 'audit' parameter value (%s)\n", str); | |
1578 | audit_default = (val ? AUDIT_ON : AUDIT_OFF); | |
1579 | ||
1580 | if (audit_default == AUDIT_OFF) | |
a3f07114 | 1581 | audit_initialized = AUDIT_DISABLED; |
5d842a5b PM |
1582 | if (audit_set_enabled(audit_default)) |
1583 | panic("audit: error setting audit state (%d)\n", audit_default); | |
a3f07114 | 1584 | |
d957f7b7 | 1585 | pr_info("%s\n", audit_default ? |
d3ca0344 | 1586 | "enabled (after initialization)" : "disabled (until reboot)"); |
a3f07114 | 1587 | |
9b41046c | 1588 | return 1; |
1da177e4 | 1589 | } |
1da177e4 LT |
1590 | __setup("audit=", audit_enable); |
1591 | ||
f910fde7 RGB |
1592 | /* Process kernel command-line parameter at boot time. |
1593 | * audit_backlog_limit=<n> */ | |
1594 | static int __init audit_backlog_limit_set(char *str) | |
1595 | { | |
3e1d0bb6 | 1596 | u32 audit_backlog_limit_arg; |
d957f7b7 | 1597 | |
f910fde7 | 1598 | pr_info("audit_backlog_limit: "); |
3e1d0bb6 JP |
1599 | if (kstrtouint(str, 0, &audit_backlog_limit_arg)) { |
1600 | pr_cont("using default of %u, unable to parse %s\n", | |
d957f7b7 | 1601 | audit_backlog_limit, str); |
f910fde7 RGB |
1602 | return 1; |
1603 | } | |
3e1d0bb6 JP |
1604 | |
1605 | audit_backlog_limit = audit_backlog_limit_arg; | |
d957f7b7 | 1606 | pr_cont("%d\n", audit_backlog_limit); |
f910fde7 RGB |
1607 | |
1608 | return 1; | |
1609 | } | |
1610 | __setup("audit_backlog_limit=", audit_backlog_limit_set); | |
1611 | ||
16e1904e CW |
1612 | static void audit_buffer_free(struct audit_buffer *ab) |
1613 | { | |
8fc6115c CW |
1614 | if (!ab) |
1615 | return; | |
1616 | ||
d865e573 | 1617 | kfree_skb(ab->skb); |
8cc96382 | 1618 | kmem_cache_free(audit_buffer_cache, ab); |
16e1904e CW |
1619 | } |
1620 | ||
8cc96382 PM |
1621 | static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx, |
1622 | gfp_t gfp_mask, int type) | |
16e1904e | 1623 | { |
8cc96382 | 1624 | struct audit_buffer *ab; |
8fc6115c | 1625 | |
8cc96382 PM |
1626 | ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask); |
1627 | if (!ab) | |
1628 | return NULL; | |
ee080e6c EP |
1629 | |
1630 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1631 | if (!ab->skb) | |
c64e66c6 | 1632 | goto err; |
8cc96382 PM |
1633 | if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0)) |
1634 | goto err; | |
ee080e6c | 1635 | |
8cc96382 PM |
1636 | ab->ctx = ctx; |
1637 | ab->gfp_mask = gfp_mask; | |
ee080e6c | 1638 | |
16e1904e | 1639 | return ab; |
ee080e6c | 1640 | |
8fc6115c CW |
1641 | err: |
1642 | audit_buffer_free(ab); | |
1643 | return NULL; | |
16e1904e | 1644 | } |
1da177e4 | 1645 | |
b0dd25a8 RD |
1646 | /** |
1647 | * audit_serial - compute a serial number for the audit record | |
1648 | * | |
1649 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1650 | * written to user-space as soon as they are generated, so a complete |
1651 | * audit record may be written in several pieces. The timestamp of the | |
1652 | * record and this serial number are used by the user-space tools to | |
1653 | * determine which pieces belong to the same audit record. The | |
1654 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1655 | * syscall entry to syscall exit. | |
1656 | * | |
bfb4496e DW |
1657 | * NOTE: Another possibility is to store the formatted records off the |
1658 | * audit context (for those records that have a context), and emit them | |
1659 | * all at syscall exit. However, this could delay the reporting of | |
1660 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1661 | * halts). |
1662 | */ | |
bfb4496e DW |
1663 | unsigned int audit_serial(void) |
1664 | { | |
01478d7d | 1665 | static atomic_t serial = ATOMIC_INIT(0); |
d5b454f2 | 1666 | |
01478d7d | 1667 | return atomic_add_return(1, &serial); |
bfb4496e DW |
1668 | } |
1669 | ||
5600b892 | 1670 | static inline void audit_get_stamp(struct audit_context *ctx, |
2115bb25 | 1671 | struct timespec64 *t, unsigned int *serial) |
bfb4496e | 1672 | { |
48887e63 | 1673 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
e832bf48 | 1674 | *t = current_kernel_time64(); |
bfb4496e DW |
1675 | *serial = audit_serial(); |
1676 | } | |
1677 | } | |
1678 | ||
b0dd25a8 RD |
1679 | /** |
1680 | * audit_log_start - obtain an audit buffer | |
1681 | * @ctx: audit_context (may be NULL) | |
1682 | * @gfp_mask: type of allocation | |
1683 | * @type: audit message type | |
1684 | * | |
1685 | * Returns audit_buffer pointer on success or NULL on error. | |
1686 | * | |
1687 | * Obtain an audit buffer. This routine does locking to obtain the | |
1688 | * audit buffer, but then no locking is required for calls to | |
1689 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1690 | * syscall, then the syscall is marked as auditable and an audit record | |
1691 | * will be written at syscall exit. If there is no associated task, then | |
1692 | * task context (ctx) should be NULL. | |
1693 | */ | |
9796fdd8 | 1694 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1695 | int type) |
1da177e4 | 1696 | { |
31975424 | 1697 | struct audit_buffer *ab; |
2115bb25 | 1698 | struct timespec64 t; |
31975424 | 1699 | unsigned int uninitialized_var(serial); |
1da177e4 | 1700 | |
a3f07114 | 1701 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1702 | return NULL; |
1703 | ||
86b2efbe | 1704 | if (unlikely(!audit_filter(type, AUDIT_FILTER_TYPE))) |
c8edc80c DK |
1705 | return NULL; |
1706 | ||
5b52330b | 1707 | /* NOTE: don't ever fail/sleep on these two conditions: |
a09cfa47 PM |
1708 | * 1. auditd generated record - since we need auditd to drain the |
1709 | * queue; also, when we are checking for auditd, compare PIDs using | |
1710 | * task_tgid_vnr() since auditd_pid is set in audit_receive_msg() | |
1711 | * using a PID anchored in the caller's namespace | |
5b52330b PM |
1712 | * 2. generator holding the audit_cmd_mutex - we don't want to block |
1713 | * while holding the mutex */ | |
1714 | if (!(auditd_test_task(current) || | |
1715 | (current == __mutex_owner(&audit_cmd_mutex)))) { | |
1716 | long stime = audit_backlog_wait_time; | |
31975424 PM |
1717 | |
1718 | while (audit_backlog_limit && | |
1719 | (skb_queue_len(&audit_queue) > audit_backlog_limit)) { | |
1720 | /* wake kauditd to try and flush the queue */ | |
1721 | wake_up_interruptible(&kauditd_wait); | |
9ad9ad38 | 1722 | |
31975424 PM |
1723 | /* sleep if we are allowed and we haven't exhausted our |
1724 | * backlog wait limit */ | |
5b52330b | 1725 | if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) { |
31975424 PM |
1726 | DECLARE_WAITQUEUE(wait, current); |
1727 | ||
1728 | add_wait_queue_exclusive(&audit_backlog_wait, | |
1729 | &wait); | |
1730 | set_current_state(TASK_UNINTERRUPTIBLE); | |
5b52330b | 1731 | stime = schedule_timeout(stime); |
31975424 PM |
1732 | remove_wait_queue(&audit_backlog_wait, &wait); |
1733 | } else { | |
1734 | if (audit_rate_check() && printk_ratelimit()) | |
1735 | pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n", | |
1736 | skb_queue_len(&audit_queue), | |
1737 | audit_backlog_limit); | |
1738 | audit_log_lost("backlog limit exceeded"); | |
1739 | return NULL; | |
8ac1c8d5 | 1740 | } |
9ad9ad38 | 1741 | } |
fb19b4c6 DW |
1742 | } |
1743 | ||
9ad9ad38 | 1744 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1745 | if (!ab) { |
1746 | audit_log_lost("out of memory in audit_log_start"); | |
1747 | return NULL; | |
1748 | } | |
1749 | ||
bfb4496e | 1750 | audit_get_stamp(ab->ctx, &t, &serial); |
2115bb25 DD |
1751 | audit_log_format(ab, "audit(%llu.%03lu:%u): ", |
1752 | (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial); | |
31975424 | 1753 | |
1da177e4 LT |
1754 | return ab; |
1755 | } | |
1756 | ||
8fc6115c | 1757 | /** |
5ac52f33 | 1758 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1759 | * @ab: audit_buffer |
b0dd25a8 | 1760 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1761 | * |
1762 | * Returns 0 (no space) on failed expansion, or available space if | |
1763 | * successful. | |
1764 | */ | |
e3b926b4 | 1765 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1766 | { |
5ac52f33 | 1767 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1768 | int oldtail = skb_tailroom(skb); |
1769 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1770 | int newtail = skb_tailroom(skb); | |
1771 | ||
5ac52f33 CW |
1772 | if (ret < 0) { |
1773 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1774 | return 0; |
5ac52f33 | 1775 | } |
406a1d86 HX |
1776 | |
1777 | skb->truesize += newtail - oldtail; | |
1778 | return newtail; | |
8fc6115c | 1779 | } |
1da177e4 | 1780 | |
b0dd25a8 RD |
1781 | /* |
1782 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1783 | * room in the audit buffer, more room will be allocated and vsnprint |
1784 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1785 | * can't format message larger than 1024 bytes, so we don't either. |
1786 | */ | |
1da177e4 LT |
1787 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1788 | va_list args) | |
1789 | { | |
1790 | int len, avail; | |
5ac52f33 | 1791 | struct sk_buff *skb; |
eecb0a73 | 1792 | va_list args2; |
1da177e4 LT |
1793 | |
1794 | if (!ab) | |
1795 | return; | |
1796 | ||
5ac52f33 CW |
1797 | BUG_ON(!ab->skb); |
1798 | skb = ab->skb; | |
1799 | avail = skb_tailroom(skb); | |
1800 | if (avail == 0) { | |
e3b926b4 | 1801 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1802 | if (!avail) |
1803 | goto out; | |
1da177e4 | 1804 | } |
eecb0a73 | 1805 | va_copy(args2, args); |
27a884dc | 1806 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1807 | if (len >= avail) { |
1808 | /* The printk buffer is 1024 bytes long, so if we get | |
1809 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1810 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1811 | avail = audit_expand(ab, |
1812 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1813 | if (!avail) |
a0e86bd4 | 1814 | goto out_va_end; |
27a884dc | 1815 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1816 | } |
168b7173 SG |
1817 | if (len > 0) |
1818 | skb_put(skb, len); | |
a0e86bd4 JJ |
1819 | out_va_end: |
1820 | va_end(args2); | |
8fc6115c CW |
1821 | out: |
1822 | return; | |
1da177e4 LT |
1823 | } |
1824 | ||
b0dd25a8 RD |
1825 | /** |
1826 | * audit_log_format - format a message into the audit buffer. | |
1827 | * @ab: audit_buffer | |
1828 | * @fmt: format string | |
1829 | * @...: optional parameters matching @fmt string | |
1830 | * | |
1831 | * All the work is done in audit_log_vformat. | |
1832 | */ | |
1da177e4 LT |
1833 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1834 | { | |
1835 | va_list args; | |
1836 | ||
1837 | if (!ab) | |
1838 | return; | |
1839 | va_start(args, fmt); | |
1840 | audit_log_vformat(ab, fmt, args); | |
1841 | va_end(args); | |
1842 | } | |
1843 | ||
b0dd25a8 | 1844 | /** |
196a5085 | 1845 | * audit_log_n_hex - convert a buffer to hex and append it to the audit skb |
b0dd25a8 RD |
1846 | * @ab: the audit_buffer |
1847 | * @buf: buffer to convert to hex | |
1848 | * @len: length of @buf to be converted | |
1849 | * | |
1850 | * No return value; failure to expand is silently ignored. | |
1851 | * | |
1852 | * This function will take the passed buf and convert it into a string of | |
1853 | * ascii hex digits. The new string is placed onto the skb. | |
1854 | */ | |
b556f8ad | 1855 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1856 | size_t len) |
83c7d091 | 1857 | { |
168b7173 SG |
1858 | int i, avail, new_len; |
1859 | unsigned char *ptr; | |
1860 | struct sk_buff *skb; | |
168b7173 | 1861 | |
8ef2d304 AG |
1862 | if (!ab) |
1863 | return; | |
1864 | ||
168b7173 SG |
1865 | BUG_ON(!ab->skb); |
1866 | skb = ab->skb; | |
1867 | avail = skb_tailroom(skb); | |
1868 | new_len = len<<1; | |
1869 | if (new_len >= avail) { | |
1870 | /* Round the buffer request up to the next multiple */ | |
1871 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1872 | avail = audit_expand(ab, new_len); | |
1873 | if (!avail) | |
1874 | return; | |
1875 | } | |
83c7d091 | 1876 | |
27a884dc | 1877 | ptr = skb_tail_pointer(skb); |
b8dbc324 JP |
1878 | for (i = 0; i < len; i++) |
1879 | ptr = hex_byte_pack_upper(ptr, buf[i]); | |
168b7173 SG |
1880 | *ptr = 0; |
1881 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 DW |
1882 | } |
1883 | ||
9c937dcc AG |
1884 | /* |
1885 | * Format a string of no more than slen characters into the audit buffer, | |
1886 | * enclosed in quote marks. | |
1887 | */ | |
b556f8ad EP |
1888 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1889 | size_t slen) | |
9c937dcc AG |
1890 | { |
1891 | int avail, new_len; | |
1892 | unsigned char *ptr; | |
1893 | struct sk_buff *skb; | |
1894 | ||
8ef2d304 AG |
1895 | if (!ab) |
1896 | return; | |
1897 | ||
9c937dcc AG |
1898 | BUG_ON(!ab->skb); |
1899 | skb = ab->skb; | |
1900 | avail = skb_tailroom(skb); | |
1901 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1902 | if (new_len > avail) { | |
1903 | avail = audit_expand(ab, new_len); | |
1904 | if (!avail) | |
1905 | return; | |
1906 | } | |
27a884dc | 1907 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1908 | *ptr++ = '"'; |
1909 | memcpy(ptr, string, slen); | |
1910 | ptr += slen; | |
1911 | *ptr++ = '"'; | |
1912 | *ptr = 0; | |
1913 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1914 | } | |
1915 | ||
de6bbd1d EP |
1916 | /** |
1917 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1918 | * @string: string to be checked |
1919 | * @len: max length of the string to check | |
de6bbd1d | 1920 | */ |
9fcf836b | 1921 | bool audit_string_contains_control(const char *string, size_t len) |
de6bbd1d EP |
1922 | { |
1923 | const unsigned char *p; | |
b3897f56 | 1924 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1925 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
9fcf836b | 1926 | return true; |
de6bbd1d | 1927 | } |
9fcf836b | 1928 | return false; |
de6bbd1d EP |
1929 | } |
1930 | ||
b0dd25a8 | 1931 | /** |
522ed776 | 1932 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1933 | * @ab: audit_buffer |
f706d5d2 | 1934 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1935 | * @string: string to be logged |
1936 | * | |
1937 | * This code will escape a string that is passed to it if the string | |
1938 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1939 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1940 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1941 | * |
1942 | * The caller specifies the number of characters in the string to log, which may | |
1943 | * or may not be the entire string. | |
b0dd25a8 | 1944 | */ |
b556f8ad EP |
1945 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1946 | size_t len) | |
83c7d091 | 1947 | { |
de6bbd1d | 1948 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1949 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1950 | else |
b556f8ad | 1951 | audit_log_n_string(ab, string, len); |
83c7d091 DW |
1952 | } |
1953 | ||
9c937dcc | 1954 | /** |
522ed776 | 1955 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1956 | * @ab: audit_buffer |
1957 | * @string: string to be logged | |
1958 | * | |
522ed776 | 1959 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1960 | * determine string length. |
1961 | */ | |
de6bbd1d | 1962 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1963 | { |
b556f8ad | 1964 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1965 | } |
1966 | ||
168b7173 | 1967 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1968 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1969 | const struct path *path) |
1da177e4 | 1970 | { |
44707fdf | 1971 | char *p, *pathname; |
1da177e4 | 1972 | |
8fc6115c | 1973 | if (prefix) |
c158a35c | 1974 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1975 | |
168b7173 | 1976 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1977 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1978 | if (!pathname) { | |
def57543 | 1979 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1980 | return; |
1da177e4 | 1981 | } |
cf28b486 | 1982 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1983 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1984 | /* FIXME: can we save some information here? */ | |
def57543 | 1985 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1986 | } else |
168b7173 | 1987 | audit_log_untrustedstring(ab, p); |
44707fdf | 1988 | kfree(pathname); |
1da177e4 LT |
1989 | } |
1990 | ||
4d3fb709 EP |
1991 | void audit_log_session_info(struct audit_buffer *ab) |
1992 | { | |
4440e854 | 1993 | unsigned int sessionid = audit_get_sessionid(current); |
4d3fb709 EP |
1994 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); |
1995 | ||
b8f89caa | 1996 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1997 | } |
1998 | ||
9d960985 EP |
1999 | void audit_log_key(struct audit_buffer *ab, char *key) |
2000 | { | |
2001 | audit_log_format(ab, " key="); | |
2002 | if (key) | |
2003 | audit_log_untrustedstring(ab, key); | |
2004 | else | |
2005 | audit_log_format(ab, "(null)"); | |
2006 | } | |
2007 | ||
b24a30a7 EP |
2008 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
2009 | { | |
2010 | int i; | |
2011 | ||
2012 | audit_log_format(ab, " %s=", prefix); | |
2013 | CAP_FOR_EACH_U32(i) { | |
2014 | audit_log_format(ab, "%08x", | |
7d8b6c63 | 2015 | cap->cap[CAP_LAST_U32 - i]); |
b24a30a7 EP |
2016 | } |
2017 | } | |
2018 | ||
691e6d59 | 2019 | static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) |
b24a30a7 | 2020 | { |
4b3e4ed6 RGB |
2021 | audit_log_cap(ab, "cap_fp", &name->fcap.permitted); |
2022 | audit_log_cap(ab, "cap_fi", &name->fcap.inheritable); | |
2023 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
2024 | name->fcap.fE, name->fcap_ver); | |
b24a30a7 EP |
2025 | } |
2026 | ||
2027 | static inline int audit_copy_fcaps(struct audit_names *name, | |
2028 | const struct dentry *dentry) | |
2029 | { | |
2030 | struct cpu_vfs_cap_data caps; | |
2031 | int rc; | |
2032 | ||
2033 | if (!dentry) | |
2034 | return 0; | |
2035 | ||
2036 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
2037 | if (rc) | |
2038 | return rc; | |
2039 | ||
2040 | name->fcap.permitted = caps.permitted; | |
2041 | name->fcap.inheritable = caps.inheritable; | |
2042 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
2043 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
2044 | VFS_CAP_REVISION_SHIFT; | |
2045 | ||
2046 | return 0; | |
2047 | } | |
2048 | ||
2049 | /* Copy inode data into an audit_names. */ | |
2050 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
d6335d77 | 2051 | struct inode *inode) |
b24a30a7 EP |
2052 | { |
2053 | name->ino = inode->i_ino; | |
2054 | name->dev = inode->i_sb->s_dev; | |
2055 | name->mode = inode->i_mode; | |
2056 | name->uid = inode->i_uid; | |
2057 | name->gid = inode->i_gid; | |
2058 | name->rdev = inode->i_rdev; | |
2059 | security_inode_getsecid(inode, &name->osid); | |
2060 | audit_copy_fcaps(name, dentry); | |
2061 | } | |
2062 | ||
2063 | /** | |
2064 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
2065 | * @context: audit_context for the task | |
2066 | * @n: audit_names structure with reportable details | |
2067 | * @path: optional path to report instead of audit_names->name | |
2068 | * @record_num: record number to report when handling a list of names | |
2069 | * @call_panic: optional pointer to int that will be updated if secid fails | |
2070 | */ | |
2071 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
8bd10763 | 2072 | const struct path *path, int record_num, int *call_panic) |
b24a30a7 EP |
2073 | { |
2074 | struct audit_buffer *ab; | |
2075 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
2076 | if (!ab) | |
2077 | return; | |
2078 | ||
2079 | audit_log_format(ab, "item=%d", record_num); | |
2080 | ||
2081 | if (path) | |
2082 | audit_log_d_path(ab, " name=", path); | |
2083 | else if (n->name) { | |
2084 | switch (n->name_len) { | |
2085 | case AUDIT_NAME_FULL: | |
2086 | /* log the full path */ | |
2087 | audit_log_format(ab, " name="); | |
2088 | audit_log_untrustedstring(ab, n->name->name); | |
2089 | break; | |
2090 | case 0: | |
2091 | /* name was specified as a relative path and the | |
2092 | * directory component is the cwd */ | |
2093 | audit_log_d_path(ab, " name=", &context->pwd); | |
2094 | break; | |
2095 | default: | |
2096 | /* log the name's directory component */ | |
2097 | audit_log_format(ab, " name="); | |
2098 | audit_log_n_untrustedstring(ab, n->name->name, | |
2099 | n->name_len); | |
2100 | } | |
2101 | } else | |
2102 | audit_log_format(ab, " name=(null)"); | |
2103 | ||
425afcff | 2104 | if (n->ino != AUDIT_INO_UNSET) |
b24a30a7 EP |
2105 | audit_log_format(ab, " inode=%lu" |
2106 | " dev=%02x:%02x mode=%#ho" | |
2107 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
2108 | n->ino, | |
2109 | MAJOR(n->dev), | |
2110 | MINOR(n->dev), | |
2111 | n->mode, | |
2112 | from_kuid(&init_user_ns, n->uid), | |
2113 | from_kgid(&init_user_ns, n->gid), | |
2114 | MAJOR(n->rdev), | |
2115 | MINOR(n->rdev)); | |
b24a30a7 EP |
2116 | if (n->osid != 0) { |
2117 | char *ctx = NULL; | |
2118 | u32 len; | |
2119 | if (security_secid_to_secctx( | |
2120 | n->osid, &ctx, &len)) { | |
2121 | audit_log_format(ab, " osid=%u", n->osid); | |
2122 | if (call_panic) | |
2123 | *call_panic = 2; | |
2124 | } else { | |
2125 | audit_log_format(ab, " obj=%s", ctx); | |
2126 | security_release_secctx(ctx, len); | |
2127 | } | |
2128 | } | |
2129 | ||
d3aea84a JL |
2130 | /* log the audit_names record type */ |
2131 | audit_log_format(ab, " nametype="); | |
2132 | switch(n->type) { | |
2133 | case AUDIT_TYPE_NORMAL: | |
2134 | audit_log_format(ab, "NORMAL"); | |
2135 | break; | |
2136 | case AUDIT_TYPE_PARENT: | |
2137 | audit_log_format(ab, "PARENT"); | |
2138 | break; | |
2139 | case AUDIT_TYPE_CHILD_DELETE: | |
2140 | audit_log_format(ab, "DELETE"); | |
2141 | break; | |
2142 | case AUDIT_TYPE_CHILD_CREATE: | |
2143 | audit_log_format(ab, "CREATE"); | |
2144 | break; | |
2145 | default: | |
2146 | audit_log_format(ab, "UNKNOWN"); | |
2147 | break; | |
2148 | } | |
2149 | ||
b24a30a7 EP |
2150 | audit_log_fcaps(ab, n); |
2151 | audit_log_end(ab); | |
2152 | } | |
2153 | ||
2154 | int audit_log_task_context(struct audit_buffer *ab) | |
2155 | { | |
2156 | char *ctx = NULL; | |
2157 | unsigned len; | |
2158 | int error; | |
2159 | u32 sid; | |
2160 | ||
2161 | security_task_getsecid(current, &sid); | |
2162 | if (!sid) | |
2163 | return 0; | |
2164 | ||
2165 | error = security_secid_to_secctx(sid, &ctx, &len); | |
2166 | if (error) { | |
2167 | if (error != -EINVAL) | |
2168 | goto error_path; | |
2169 | return 0; | |
2170 | } | |
2171 | ||
2172 | audit_log_format(ab, " subj=%s", ctx); | |
2173 | security_release_secctx(ctx, len); | |
2174 | return 0; | |
2175 | ||
2176 | error_path: | |
2177 | audit_panic("error in audit_log_task_context"); | |
2178 | return error; | |
2179 | } | |
2180 | EXPORT_SYMBOL(audit_log_task_context); | |
2181 | ||
4766b199 DB |
2182 | void audit_log_d_path_exe(struct audit_buffer *ab, |
2183 | struct mm_struct *mm) | |
2184 | { | |
5b282552 DB |
2185 | struct file *exe_file; |
2186 | ||
2187 | if (!mm) | |
2188 | goto out_null; | |
4766b199 | 2189 | |
5b282552 DB |
2190 | exe_file = get_mm_exe_file(mm); |
2191 | if (!exe_file) | |
2192 | goto out_null; | |
2193 | ||
2194 | audit_log_d_path(ab, " exe=", &exe_file->f_path); | |
2195 | fput(exe_file); | |
2196 | return; | |
2197 | out_null: | |
2198 | audit_log_format(ab, " exe=(null)"); | |
4766b199 DB |
2199 | } |
2200 | ||
3f5be2da RGB |
2201 | struct tty_struct *audit_get_tty(struct task_struct *tsk) |
2202 | { | |
2203 | struct tty_struct *tty = NULL; | |
2204 | unsigned long flags; | |
2205 | ||
2206 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | |
2207 | if (tsk->signal) | |
2208 | tty = tty_kref_get(tsk->signal->tty); | |
2209 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | |
2210 | return tty; | |
2211 | } | |
2212 | ||
2213 | void audit_put_tty(struct tty_struct *tty) | |
2214 | { | |
2215 | tty_kref_put(tty); | |
2216 | } | |
2217 | ||
b24a30a7 EP |
2218 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) |
2219 | { | |
2220 | const struct cred *cred; | |
9eab339b | 2221 | char comm[sizeof(tsk->comm)]; |
db0a6fb5 | 2222 | struct tty_struct *tty; |
b24a30a7 EP |
2223 | |
2224 | if (!ab) | |
2225 | return; | |
2226 | ||
2227 | /* tsk == current */ | |
2228 | cred = current_cred(); | |
db0a6fb5 | 2229 | tty = audit_get_tty(tsk); |
b24a30a7 | 2230 | audit_log_format(ab, |
c92cdeb4 | 2231 | " ppid=%d pid=%d auid=%u uid=%u gid=%u" |
b24a30a7 | 2232 | " euid=%u suid=%u fsuid=%u" |
2f2ad101 | 2233 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", |
c92cdeb4 | 2234 | task_ppid_nr(tsk), |
fa2bea2f | 2235 | task_tgid_nr(tsk), |
b24a30a7 EP |
2236 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), |
2237 | from_kuid(&init_user_ns, cred->uid), | |
2238 | from_kgid(&init_user_ns, cred->gid), | |
2239 | from_kuid(&init_user_ns, cred->euid), | |
2240 | from_kuid(&init_user_ns, cred->suid), | |
2241 | from_kuid(&init_user_ns, cred->fsuid), | |
2242 | from_kgid(&init_user_ns, cred->egid), | |
2243 | from_kgid(&init_user_ns, cred->sgid), | |
2244 | from_kgid(&init_user_ns, cred->fsgid), | |
db0a6fb5 RGB |
2245 | tty ? tty_name(tty) : "(none)", |
2246 | audit_get_sessionid(tsk)); | |
2247 | audit_put_tty(tty); | |
b24a30a7 | 2248 | audit_log_format(ab, " comm="); |
9eab339b | 2249 | audit_log_untrustedstring(ab, get_task_comm(comm, tsk)); |
4766b199 | 2250 | audit_log_d_path_exe(ab, tsk->mm); |
b24a30a7 EP |
2251 | audit_log_task_context(ab); |
2252 | } | |
2253 | EXPORT_SYMBOL(audit_log_task_info); | |
2254 | ||
a51d9eaa KC |
2255 | /** |
2256 | * audit_log_link_denied - report a link restriction denial | |
22011964 | 2257 | * @operation: specific link operation |
a51d9eaa KC |
2258 | * @link: the path that triggered the restriction |
2259 | */ | |
8bd10763 | 2260 | void audit_log_link_denied(const char *operation, const struct path *link) |
a51d9eaa KC |
2261 | { |
2262 | struct audit_buffer *ab; | |
b24a30a7 EP |
2263 | struct audit_names *name; |
2264 | ||
2265 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
2266 | if (!name) | |
2267 | return; | |
a51d9eaa | 2268 | |
b24a30a7 | 2269 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
2270 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
2271 | AUDIT_ANOM_LINK); | |
d1c7d97a | 2272 | if (!ab) |
b24a30a7 EP |
2273 | goto out; |
2274 | audit_log_format(ab, "op=%s", operation); | |
2275 | audit_log_task_info(ab, current); | |
2276 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 2277 | audit_log_end(ab); |
b24a30a7 EP |
2278 | |
2279 | /* Generate AUDIT_PATH record with object. */ | |
2280 | name->type = AUDIT_TYPE_NORMAL; | |
3b362157 | 2281 | audit_copy_inode(name, link->dentry, d_backing_inode(link->dentry)); |
b24a30a7 EP |
2282 | audit_log_name(current->audit_context, name, link, 0, NULL); |
2283 | out: | |
2284 | kfree(name); | |
a51d9eaa KC |
2285 | } |
2286 | ||
b0dd25a8 RD |
2287 | /** |
2288 | * audit_log_end - end one audit record | |
2289 | * @ab: the audit_buffer | |
2290 | * | |
4aa83872 PM |
2291 | * We can not do a netlink send inside an irq context because it blocks (last |
2292 | * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a | |
2293 | * queue and a tasklet is scheduled to remove them from the queue outside the | |
2294 | * irq context. May be called in any context. | |
b0dd25a8 | 2295 | */ |
b7d11258 | 2296 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 2297 | { |
5b52330b PM |
2298 | struct sk_buff *skb; |
2299 | struct nlmsghdr *nlh; | |
2300 | ||
1da177e4 LT |
2301 | if (!ab) |
2302 | return; | |
5b52330b PM |
2303 | |
2304 | if (audit_rate_check()) { | |
2305 | skb = ab->skb; | |
f3d357b0 | 2306 | ab->skb = NULL; |
5b52330b PM |
2307 | |
2308 | /* setup the netlink header, see the comments in | |
2309 | * kauditd_send_multicast_skb() for length quirks */ | |
2310 | nlh = nlmsg_hdr(skb); | |
2311 | nlh->nlmsg_len = skb->len - NLMSG_HDRLEN; | |
2312 | ||
2313 | /* queue the netlink packet and poke the kauditd thread */ | |
2314 | skb_queue_tail(&audit_queue, skb); | |
2315 | wake_up_interruptible(&kauditd_wait); | |
2316 | } else | |
2317 | audit_log_lost("rate limit exceeded"); | |
2318 | ||
16e1904e | 2319 | audit_buffer_free(ab); |
1da177e4 LT |
2320 | } |
2321 | ||
b0dd25a8 RD |
2322 | /** |
2323 | * audit_log - Log an audit record | |
2324 | * @ctx: audit context | |
2325 | * @gfp_mask: type of allocation | |
2326 | * @type: audit message type | |
2327 | * @fmt: format string to use | |
2328 | * @...: variable parameters matching the format string | |
2329 | * | |
2330 | * This is a convenience function that calls audit_log_start, | |
2331 | * audit_log_vformat, and audit_log_end. It may be called | |
2332 | * in any context. | |
2333 | */ | |
5600b892 | 2334 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 2335 | const char *fmt, ...) |
1da177e4 LT |
2336 | { |
2337 | struct audit_buffer *ab; | |
2338 | va_list args; | |
2339 | ||
9ad9ad38 | 2340 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
2341 | if (ab) { |
2342 | va_start(args, fmt); | |
2343 | audit_log_vformat(ab, fmt, args); | |
2344 | va_end(args); | |
2345 | audit_log_end(ab); | |
2346 | } | |
2347 | } | |
bf45da97 | 2348 | |
2349 | EXPORT_SYMBOL(audit_log_start); | |
2350 | EXPORT_SYMBOL(audit_log_end); | |
2351 | EXPORT_SYMBOL(audit_log_format); | |
2352 | EXPORT_SYMBOL(audit_log); |