1 /* audit.c -- Auditing support 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 * 5 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina. 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 * 24 * Goals: 1) Integrate fully with SELinux. 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 * 41 * Example user-space utilities: http://people.redhat.com/sgrubb/audit/ 42 */ 43 44 #include <linux/init.h> 45 #include <asm/types.h> 46 #include <asm/atomic.h> 47 #include <linux/mm.h> 48 #include <linux/module.h> 49 #include <linux/err.h> 50 #include <linux/kthread.h> 51 52 #include <linux/audit.h> 53 54 #include <net/sock.h> 55 #include <net/netlink.h> 56 #include <linux/skbuff.h> 57 #include <linux/netlink.h> 58 #include <linux/selinux.h> 59 #include <linux/inotify.h> 60 #include <linux/freezer.h> 61 #include <linux/tty.h> 62 63 #include "audit.h" 64 65 /* No auditing will take place until audit_initialized != 0. 66 * (Initialization happens after skb_init is called.) */ 67 static int audit_initialized; 68 69 #define AUDIT_OFF 0 70 #define AUDIT_ON 1 71 #define AUDIT_LOCKED 2 72 int audit_enabled; 73 int audit_ever_enabled; 74 75 /* Default state when kernel boots without any parameters. */ 76 static int audit_default; 77 78 /* If auditing cannot proceed, audit_failure selects what happens. */ 79 static int audit_failure = AUDIT_FAIL_PRINTK; 80 81 /* 82 * If audit records are to be written to the netlink socket, audit_pid 83 * contains the pid of the auditd process and audit_nlk_pid contains 84 * the pid to use to send netlink messages to that process. 85 */ 86 int audit_pid; 87 static int audit_nlk_pid; 88 89 /* If audit_rate_limit is non-zero, limit the rate of sending audit records 90 * to that number per second. This prevents DoS attacks, but results in 91 * audit records being dropped. */ 92 static int audit_rate_limit; 93 94 /* Number of outstanding audit_buffers allowed. */ 95 static int audit_backlog_limit = 64; 96 static int audit_backlog_wait_time = 60 * HZ; 97 static int audit_backlog_wait_overflow = 0; 98 99 /* The identity of the user shutting down the audit system. */ 100 uid_t audit_sig_uid = -1; 101 pid_t audit_sig_pid = -1; 102 u32 audit_sig_sid = 0; 103 104 /* Records can be lost in several ways: 105 0) [suppressed in audit_alloc] 106 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] 107 2) out of memory in audit_log_move [alloc_skb] 108 3) suppressed due to audit_rate_limit 109 4) suppressed due to audit_backlog_limit 110 */ 111 static atomic_t audit_lost = ATOMIC_INIT(0); 112 113 /* The netlink socket. */ 114 static struct sock *audit_sock; 115 116 /* Inotify handle. */ 117 struct inotify_handle *audit_ih; 118 119 /* Hash for inode-based rules */ 120 struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; 121 122 /* The audit_freelist is a list of pre-allocated audit buffers (if more 123 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of 124 * being placed on the freelist). */ 125 static DEFINE_SPINLOCK(audit_freelist_lock); 126 static int audit_freelist_count; 127 static LIST_HEAD(audit_freelist); 128 129 static struct sk_buff_head audit_skb_queue; 130 static struct task_struct *kauditd_task; 131 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); 132 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); 133 134 /* Serialize requests from userspace. */ 135 static DEFINE_MUTEX(audit_cmd_mutex); 136 137 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting 138 * audit records. Since printk uses a 1024 byte buffer, this buffer 139 * should be at least that large. */ 140 #define AUDIT_BUFSIZ 1024 141 142 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the 143 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ 144 #define AUDIT_MAXFREE (2*NR_CPUS) 145 146 /* The audit_buffer is used when formatting an audit record. The caller 147 * locks briefly to get the record off the freelist or to allocate the 148 * buffer, and locks briefly to send the buffer to the netlink layer or 149 * to place it on a transmit queue. Multiple audit_buffers can be in 150 * use simultaneously. */ 151 struct audit_buffer { 152 struct list_head list; 153 struct sk_buff *skb; /* formatted skb ready to send */ 154 struct audit_context *ctx; /* NULL or associated context */ 155 gfp_t gfp_mask; 156 }; 157 158 static void audit_set_pid(struct audit_buffer *ab, pid_t pid) 159 { 160 if (ab) { 161 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); 162 nlh->nlmsg_pid = pid; 163 } 164 } 165 166 void audit_panic(const char *message) 167 { 168 switch (audit_failure) 169 { 170 case AUDIT_FAIL_SILENT: 171 break; 172 case AUDIT_FAIL_PRINTK: 173 if (printk_ratelimit()) 174 printk(KERN_ERR "audit: %s\n", message); 175 break; 176 case AUDIT_FAIL_PANIC: 177 /* test audit_pid since printk is always losey, why bother? */ 178 if (audit_pid) 179 panic("audit: %s\n", message); 180 break; 181 } 182 } 183 184 static inline int audit_rate_check(void) 185 { 186 static unsigned long last_check = 0; 187 static int messages = 0; 188 static DEFINE_SPINLOCK(lock); 189 unsigned long flags; 190 unsigned long now; 191 unsigned long elapsed; 192 int retval = 0; 193 194 if (!audit_rate_limit) return 1; 195 196 spin_lock_irqsave(&lock, flags); 197 if (++messages < audit_rate_limit) { 198 retval = 1; 199 } else { 200 now = jiffies; 201 elapsed = now - last_check; 202 if (elapsed > HZ) { 203 last_check = now; 204 messages = 0; 205 retval = 1; 206 } 207 } 208 spin_unlock_irqrestore(&lock, flags); 209 210 return retval; 211 } 212 213 /** 214 * audit_log_lost - conditionally log lost audit message event 215 * @message: the message stating reason for lost audit message 216 * 217 * Emit at least 1 message per second, even if audit_rate_check is 218 * throttling. 219 * Always increment the lost messages counter. 220 */ 221 void audit_log_lost(const char *message) 222 { 223 static unsigned long last_msg = 0; 224 static DEFINE_SPINLOCK(lock); 225 unsigned long flags; 226 unsigned long now; 227 int print; 228 229 atomic_inc(&audit_lost); 230 231 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); 232 233 if (!print) { 234 spin_lock_irqsave(&lock, flags); 235 now = jiffies; 236 if (now - last_msg > HZ) { 237 print = 1; 238 last_msg = now; 239 } 240 spin_unlock_irqrestore(&lock, flags); 241 } 242 243 if (print) { 244 if (printk_ratelimit()) 245 printk(KERN_WARNING 246 "audit: audit_lost=%d audit_rate_limit=%d " 247 "audit_backlog_limit=%d\n", 248 atomic_read(&audit_lost), 249 audit_rate_limit, 250 audit_backlog_limit); 251 audit_panic(message); 252 } 253 } 254 255 static int audit_log_config_change(char *function_name, int new, int old, 256 uid_t loginuid, u32 sid, int allow_changes) 257 { 258 struct audit_buffer *ab; 259 int rc = 0; 260 261 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); 262 audit_log_format(ab, "%s=%d old=%d by auid=%u", function_name, new, 263 old, loginuid); 264 if (sid) { 265 char *ctx = NULL; 266 u32 len; 267 268 rc = selinux_sid_to_string(sid, &ctx, &len); 269 if (rc) { 270 audit_log_format(ab, " sid=%u", sid); 271 allow_changes = 0; /* Something weird, deny request */ 272 } else { 273 audit_log_format(ab, " subj=%s", ctx); 274 kfree(ctx); 275 } 276 } 277 audit_log_format(ab, " res=%d", allow_changes); 278 audit_log_end(ab); 279 return rc; 280 } 281 282 static int audit_do_config_change(char *function_name, int *to_change, 283 int new, uid_t loginuid, u32 sid) 284 { 285 int allow_changes, rc = 0, old = *to_change; 286 287 /* check if we are locked */ 288 if (audit_enabled == AUDIT_LOCKED) 289 allow_changes = 0; 290 else 291 allow_changes = 1; 292 293 if (audit_enabled != AUDIT_OFF) { 294 rc = audit_log_config_change(function_name, new, old, 295 loginuid, sid, allow_changes); 296 if (rc) 297 allow_changes = 0; 298 } 299 300 /* If we are allowed, make the change */ 301 if (allow_changes == 1) 302 *to_change = new; 303 /* Not allowed, update reason */ 304 else if (rc == 0) 305 rc = -EPERM; 306 return rc; 307 } 308 309 static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid) 310 { 311 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, 312 limit, loginuid, sid); 313 } 314 315 static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid) 316 { 317 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, 318 limit, loginuid, sid); 319 } 320 321 static int audit_set_enabled(int state, uid_t loginuid, u32 sid) 322 { 323 int rc; 324 if (state < AUDIT_OFF || state > AUDIT_LOCKED) 325 return -EINVAL; 326 327 rc = audit_do_config_change("audit_enabled", &audit_enabled, state, 328 loginuid, sid); 329 330 if (!rc) 331 audit_ever_enabled |= !!state; 332 333 return rc; 334 } 335 336 static int audit_set_failure(int state, uid_t loginuid, u32 sid) 337 { 338 if (state != AUDIT_FAIL_SILENT 339 && state != AUDIT_FAIL_PRINTK 340 && state != AUDIT_FAIL_PANIC) 341 return -EINVAL; 342 343 return audit_do_config_change("audit_failure", &audit_failure, state, 344 loginuid, sid); 345 } 346 347 static int kauditd_thread(void *dummy) 348 { 349 struct sk_buff *skb; 350 351 set_freezable(); 352 while (!kthread_should_stop()) { 353 skb = skb_dequeue(&audit_skb_queue); 354 wake_up(&audit_backlog_wait); 355 if (skb) { 356 if (audit_pid) { 357 int err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0); 358 if (err < 0) { 359 BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */ 360 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); 361 audit_log_lost("auditd dissapeared\n"); 362 audit_pid = 0; 363 } 364 } else { 365 if (printk_ratelimit()) 366 printk(KERN_NOTICE "%s\n", skb->data + 367 NLMSG_SPACE(0)); 368 else 369 audit_log_lost("printk limit exceeded\n"); 370 kfree_skb(skb); 371 } 372 } else { 373 DECLARE_WAITQUEUE(wait, current); 374 set_current_state(TASK_INTERRUPTIBLE); 375 add_wait_queue(&kauditd_wait, &wait); 376 377 if (!skb_queue_len(&audit_skb_queue)) { 378 try_to_freeze(); 379 schedule(); 380 } 381 382 __set_current_state(TASK_RUNNING); 383 remove_wait_queue(&kauditd_wait, &wait); 384 } 385 } 386 return 0; 387 } 388 389 static int audit_prepare_user_tty(pid_t pid, uid_t loginuid) 390 { 391 struct task_struct *tsk; 392 int err; 393 394 read_lock(&tasklist_lock); 395 tsk = find_task_by_pid(pid); 396 err = -ESRCH; 397 if (!tsk) 398 goto out; 399 err = 0; 400 401 spin_lock_irq(&tsk->sighand->siglock); 402 if (!tsk->signal->audit_tty) 403 err = -EPERM; 404 spin_unlock_irq(&tsk->sighand->siglock); 405 if (err) 406 goto out; 407 408 tty_audit_push_task(tsk, loginuid); 409 out: 410 read_unlock(&tasklist_lock); 411 return err; 412 } 413 414 int audit_send_list(void *_dest) 415 { 416 struct audit_netlink_list *dest = _dest; 417 int pid = dest->pid; 418 struct sk_buff *skb; 419 420 /* wait for parent to finish and send an ACK */ 421 mutex_lock(&audit_cmd_mutex); 422 mutex_unlock(&audit_cmd_mutex); 423 424 while ((skb = __skb_dequeue(&dest->q)) != NULL) 425 netlink_unicast(audit_sock, skb, pid, 0); 426 427 kfree(dest); 428 429 return 0; 430 } 431 432 #ifdef CONFIG_AUDIT_TREE 433 static int prune_tree_thread(void *unused) 434 { 435 mutex_lock(&audit_cmd_mutex); 436 audit_prune_trees(); 437 mutex_unlock(&audit_cmd_mutex); 438 return 0; 439 } 440 441 void audit_schedule_prune(void) 442 { 443 kthread_run(prune_tree_thread, NULL, "audit_prune_tree"); 444 } 445 #endif 446 447 struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, 448 int multi, void *payload, int size) 449 { 450 struct sk_buff *skb; 451 struct nlmsghdr *nlh; 452 int len = NLMSG_SPACE(size); 453 void *data; 454 int flags = multi ? NLM_F_MULTI : 0; 455 int t = done ? NLMSG_DONE : type; 456 457 skb = alloc_skb(len, GFP_KERNEL); 458 if (!skb) 459 return NULL; 460 461 nlh = NLMSG_PUT(skb, pid, seq, t, size); 462 nlh->nlmsg_flags = flags; 463 data = NLMSG_DATA(nlh); 464 memcpy(data, payload, size); 465 return skb; 466 467 nlmsg_failure: /* Used by NLMSG_PUT */ 468 if (skb) 469 kfree_skb(skb); 470 return NULL; 471 } 472 473 /** 474 * audit_send_reply - send an audit reply message via netlink 475 * @pid: process id to send reply to 476 * @seq: sequence number 477 * @type: audit message type 478 * @done: done (last) flag 479 * @multi: multi-part message flag 480 * @payload: payload data 481 * @size: payload size 482 * 483 * Allocates an skb, builds the netlink message, and sends it to the pid. 484 * No failure notifications. 485 */ 486 void audit_send_reply(int pid, int seq, int type, int done, int multi, 487 void *payload, int size) 488 { 489 struct sk_buff *skb; 490 skb = audit_make_reply(pid, seq, type, done, multi, payload, size); 491 if (!skb) 492 return; 493 /* Ignore failure. It'll only happen if the sender goes away, 494 because our timeout is set to infinite. */ 495 netlink_unicast(audit_sock, skb, pid, 0); 496 return; 497 } 498 499 /* 500 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit 501 * control messages. 502 */ 503 static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) 504 { 505 int err = 0; 506 507 switch (msg_type) { 508 case AUDIT_GET: 509 case AUDIT_LIST: 510 case AUDIT_LIST_RULES: 511 case AUDIT_SET: 512 case AUDIT_ADD: 513 case AUDIT_ADD_RULE: 514 case AUDIT_DEL: 515 case AUDIT_DEL_RULE: 516 case AUDIT_SIGNAL_INFO: 517 case AUDIT_TTY_GET: 518 case AUDIT_TTY_SET: 519 case AUDIT_TRIM: 520 case AUDIT_MAKE_EQUIV: 521 if (security_netlink_recv(skb, CAP_AUDIT_CONTROL)) 522 err = -EPERM; 523 break; 524 case AUDIT_USER: 525 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: 526 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: 527 if (security_netlink_recv(skb, CAP_AUDIT_WRITE)) 528 err = -EPERM; 529 break; 530 default: /* bad msg */ 531 err = -EINVAL; 532 } 533 534 return err; 535 } 536 537 static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type, 538 u32 pid, u32 uid, uid_t auid, u32 sid) 539 { 540 int rc = 0; 541 char *ctx = NULL; 542 u32 len; 543 544 if (!audit_enabled) { 545 *ab = NULL; 546 return rc; 547 } 548 549 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); 550 audit_log_format(*ab, "user pid=%d uid=%u auid=%u", 551 pid, uid, auid); 552 if (sid) { 553 rc = selinux_sid_to_string(sid, &ctx, &len); 554 if (rc) 555 audit_log_format(*ab, " ssid=%u", sid); 556 else 557 audit_log_format(*ab, " subj=%s", ctx); 558 kfree(ctx); 559 } 560 561 return rc; 562 } 563 564 static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 565 { 566 u32 uid, pid, seq, sid; 567 void *data; 568 struct audit_status *status_get, status_set; 569 int err; 570 struct audit_buffer *ab; 571 u16 msg_type = nlh->nlmsg_type; 572 uid_t loginuid; /* loginuid of sender */ 573 struct audit_sig_info *sig_data; 574 char *ctx = NULL; 575 u32 len; 576 577 err = audit_netlink_ok(skb, msg_type); 578 if (err) 579 return err; 580 581 /* As soon as there's any sign of userspace auditd, 582 * start kauditd to talk to it */ 583 if (!kauditd_task) 584 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); 585 if (IS_ERR(kauditd_task)) { 586 err = PTR_ERR(kauditd_task); 587 kauditd_task = NULL; 588 return err; 589 } 590 591 pid = NETLINK_CREDS(skb)->pid; 592 uid = NETLINK_CREDS(skb)->uid; 593 loginuid = NETLINK_CB(skb).loginuid; 594 sid = NETLINK_CB(skb).sid; 595 seq = nlh->nlmsg_seq; 596 data = NLMSG_DATA(nlh); 597 598 switch (msg_type) { 599 case AUDIT_GET: 600 status_set.enabled = audit_enabled; 601 status_set.failure = audit_failure; 602 status_set.pid = audit_pid; 603 status_set.rate_limit = audit_rate_limit; 604 status_set.backlog_limit = audit_backlog_limit; 605 status_set.lost = atomic_read(&audit_lost); 606 status_set.backlog = skb_queue_len(&audit_skb_queue); 607 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0, 608 &status_set, sizeof(status_set)); 609 break; 610 case AUDIT_SET: 611 if (nlh->nlmsg_len < sizeof(struct audit_status)) 612 return -EINVAL; 613 status_get = (struct audit_status *)data; 614 if (status_get->mask & AUDIT_STATUS_ENABLED) { 615 err = audit_set_enabled(status_get->enabled, 616 loginuid, sid); 617 if (err < 0) return err; 618 } 619 if (status_get->mask & AUDIT_STATUS_FAILURE) { 620 err = audit_set_failure(status_get->failure, 621 loginuid, sid); 622 if (err < 0) return err; 623 } 624 if (status_get->mask & AUDIT_STATUS_PID) { 625 int new_pid = status_get->pid; 626 627 if (audit_enabled != AUDIT_OFF) 628 audit_log_config_change("audit_pid", new_pid, 629 audit_pid, loginuid, 630 sid, 1); 631 632 audit_pid = new_pid; 633 audit_nlk_pid = NETLINK_CB(skb).pid; 634 } 635 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) 636 err = audit_set_rate_limit(status_get->rate_limit, 637 loginuid, sid); 638 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) 639 err = audit_set_backlog_limit(status_get->backlog_limit, 640 loginuid, sid); 641 break; 642 case AUDIT_USER: 643 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: 644 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: 645 if (!audit_enabled && msg_type != AUDIT_USER_AVC) 646 return 0; 647 648 err = audit_filter_user(&NETLINK_CB(skb), msg_type); 649 if (err == 1) { 650 err = 0; 651 if (msg_type == AUDIT_USER_TTY) { 652 err = audit_prepare_user_tty(pid, loginuid); 653 if (err) 654 break; 655 } 656 audit_log_common_recv_msg(&ab, msg_type, pid, uid, 657 loginuid, sid); 658 659 if (msg_type != AUDIT_USER_TTY) 660 audit_log_format(ab, " msg='%.1024s'", 661 (char *)data); 662 else { 663 int size; 664 665 audit_log_format(ab, " msg="); 666 size = nlmsg_len(nlh); 667 audit_log_n_untrustedstring(ab, size, 668 data); 669 } 670 audit_set_pid(ab, pid); 671 audit_log_end(ab); 672 } 673 break; 674 case AUDIT_ADD: 675 case AUDIT_DEL: 676 if (nlmsg_len(nlh) < sizeof(struct audit_rule)) 677 return -EINVAL; 678 if (audit_enabled == AUDIT_LOCKED) { 679 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, 680 uid, loginuid, sid); 681 682 audit_log_format(ab, " audit_enabled=%d res=0", 683 audit_enabled); 684 audit_log_end(ab); 685 return -EPERM; 686 } 687 /* fallthrough */ 688 case AUDIT_LIST: 689 err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, 690 uid, seq, data, nlmsg_len(nlh), 691 loginuid, sid); 692 break; 693 case AUDIT_ADD_RULE: 694 case AUDIT_DEL_RULE: 695 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) 696 return -EINVAL; 697 if (audit_enabled == AUDIT_LOCKED) { 698 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, 699 uid, loginuid, sid); 700 701 audit_log_format(ab, " audit_enabled=%d res=0", 702 audit_enabled); 703 audit_log_end(ab); 704 return -EPERM; 705 } 706 /* fallthrough */ 707 case AUDIT_LIST_RULES: 708 err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, 709 uid, seq, data, nlmsg_len(nlh), 710 loginuid, sid); 711 break; 712 case AUDIT_TRIM: 713 audit_trim_trees(); 714 715 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, 716 uid, loginuid, sid); 717 718 audit_log_format(ab, " op=trim res=1"); 719 audit_log_end(ab); 720 break; 721 case AUDIT_MAKE_EQUIV: { 722 void *bufp = data; 723 u32 sizes[2]; 724 size_t len = nlmsg_len(nlh); 725 char *old, *new; 726 727 err = -EINVAL; 728 if (len < 2 * sizeof(u32)) 729 break; 730 memcpy(sizes, bufp, 2 * sizeof(u32)); 731 bufp += 2 * sizeof(u32); 732 len -= 2 * sizeof(u32); 733 old = audit_unpack_string(&bufp, &len, sizes[0]); 734 if (IS_ERR(old)) { 735 err = PTR_ERR(old); 736 break; 737 } 738 new = audit_unpack_string(&bufp, &len, sizes[1]); 739 if (IS_ERR(new)) { 740 err = PTR_ERR(new); 741 kfree(old); 742 break; 743 } 744 /* OK, here comes... */ 745 err = audit_tag_tree(old, new); 746 747 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, 748 uid, loginuid, sid); 749 750 audit_log_format(ab, " op=make_equiv old="); 751 audit_log_untrustedstring(ab, old); 752 audit_log_format(ab, " new="); 753 audit_log_untrustedstring(ab, new); 754 audit_log_format(ab, " res=%d", !err); 755 audit_log_end(ab); 756 kfree(old); 757 kfree(new); 758 break; 759 } 760 case AUDIT_SIGNAL_INFO: 761 err = selinux_sid_to_string(audit_sig_sid, &ctx, &len); 762 if (err) 763 return err; 764 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); 765 if (!sig_data) { 766 kfree(ctx); 767 return -ENOMEM; 768 } 769 sig_data->uid = audit_sig_uid; 770 sig_data->pid = audit_sig_pid; 771 memcpy(sig_data->ctx, ctx, len); 772 kfree(ctx); 773 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, 774 0, 0, sig_data, sizeof(*sig_data) + len); 775 kfree(sig_data); 776 break; 777 case AUDIT_TTY_GET: { 778 struct audit_tty_status s; 779 struct task_struct *tsk; 780 781 read_lock(&tasklist_lock); 782 tsk = find_task_by_pid(pid); 783 if (!tsk) 784 err = -ESRCH; 785 else { 786 spin_lock_irq(&tsk->sighand->siglock); 787 s.enabled = tsk->signal->audit_tty != 0; 788 spin_unlock_irq(&tsk->sighand->siglock); 789 } 790 read_unlock(&tasklist_lock); 791 audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_TTY_GET, 0, 0, 792 &s, sizeof(s)); 793 break; 794 } 795 case AUDIT_TTY_SET: { 796 struct audit_tty_status *s; 797 struct task_struct *tsk; 798 799 if (nlh->nlmsg_len < sizeof(struct audit_tty_status)) 800 return -EINVAL; 801 s = data; 802 if (s->enabled != 0 && s->enabled != 1) 803 return -EINVAL; 804 read_lock(&tasklist_lock); 805 tsk = find_task_by_pid(pid); 806 if (!tsk) 807 err = -ESRCH; 808 else { 809 spin_lock_irq(&tsk->sighand->siglock); 810 tsk->signal->audit_tty = s->enabled != 0; 811 spin_unlock_irq(&tsk->sighand->siglock); 812 } 813 read_unlock(&tasklist_lock); 814 break; 815 } 816 default: 817 err = -EINVAL; 818 break; 819 } 820 821 return err < 0 ? err : 0; 822 } 823 824 /* 825 * Get message from skb (based on rtnetlink_rcv_skb). Each message is 826 * processed by audit_receive_msg. Malformed skbs with wrong length are 827 * discarded silently. 828 */ 829 static void audit_receive_skb(struct sk_buff *skb) 830 { 831 int err; 832 struct nlmsghdr *nlh; 833 u32 rlen; 834 835 while (skb->len >= NLMSG_SPACE(0)) { 836 nlh = nlmsg_hdr(skb); 837 if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) 838 return; 839 rlen = NLMSG_ALIGN(nlh->nlmsg_len); 840 if (rlen > skb->len) 841 rlen = skb->len; 842 if ((err = audit_receive_msg(skb, nlh))) { 843 netlink_ack(skb, nlh, err); 844 } else if (nlh->nlmsg_flags & NLM_F_ACK) 845 netlink_ack(skb, nlh, 0); 846 skb_pull(skb, rlen); 847 } 848 } 849 850 /* Receive messages from netlink socket. */ 851 static void audit_receive(struct sk_buff *skb) 852 { 853 mutex_lock(&audit_cmd_mutex); 854 audit_receive_skb(skb); 855 mutex_unlock(&audit_cmd_mutex); 856 } 857 858 #ifdef CONFIG_AUDITSYSCALL 859 static const struct inotify_operations audit_inotify_ops = { 860 .handle_event = audit_handle_ievent, 861 .destroy_watch = audit_free_parent, 862 }; 863 #endif 864 865 /* Initialize audit support at boot time. */ 866 static int __init audit_init(void) 867 { 868 int i; 869 870 printk(KERN_INFO "audit: initializing netlink socket (%s)\n", 871 audit_default ? "enabled" : "disabled"); 872 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, 0, 873 audit_receive, NULL, THIS_MODULE); 874 if (!audit_sock) 875 audit_panic("cannot initialize netlink socket"); 876 else 877 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; 878 879 skb_queue_head_init(&audit_skb_queue); 880 audit_initialized = 1; 881 audit_enabled = audit_default; 882 audit_ever_enabled |= !!audit_default; 883 884 /* Register the callback with selinux. This callback will be invoked 885 * when a new policy is loaded. */ 886 selinux_audit_set_callback(&selinux_audit_rule_update); 887 888 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); 889 890 #ifdef CONFIG_AUDITSYSCALL 891 audit_ih = inotify_init(&audit_inotify_ops); 892 if (IS_ERR(audit_ih)) 893 audit_panic("cannot initialize inotify handle"); 894 #endif 895 896 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) 897 INIT_LIST_HEAD(&audit_inode_hash[i]); 898 899 return 0; 900 } 901 __initcall(audit_init); 902 903 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ 904 static int __init audit_enable(char *str) 905 { 906 audit_default = !!simple_strtol(str, NULL, 0); 907 printk(KERN_INFO "audit: %s%s\n", 908 audit_default ? "enabled" : "disabled", 909 audit_initialized ? "" : " (after initialization)"); 910 if (audit_initialized) { 911 audit_enabled = audit_default; 912 audit_ever_enabled |= !!audit_default; 913 } 914 return 1; 915 } 916 917 __setup("audit=", audit_enable); 918 919 static void audit_buffer_free(struct audit_buffer *ab) 920 { 921 unsigned long flags; 922 923 if (!ab) 924 return; 925 926 if (ab->skb) 927 kfree_skb(ab->skb); 928 929 spin_lock_irqsave(&audit_freelist_lock, flags); 930 if (audit_freelist_count > AUDIT_MAXFREE) 931 kfree(ab); 932 else { 933 audit_freelist_count++; 934 list_add(&ab->list, &audit_freelist); 935 } 936 spin_unlock_irqrestore(&audit_freelist_lock, flags); 937 } 938 939 static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, 940 gfp_t gfp_mask, int type) 941 { 942 unsigned long flags; 943 struct audit_buffer *ab = NULL; 944 struct nlmsghdr *nlh; 945 946 spin_lock_irqsave(&audit_freelist_lock, flags); 947 if (!list_empty(&audit_freelist)) { 948 ab = list_entry(audit_freelist.next, 949 struct audit_buffer, list); 950 list_del(&ab->list); 951 --audit_freelist_count; 952 } 953 spin_unlock_irqrestore(&audit_freelist_lock, flags); 954 955 if (!ab) { 956 ab = kmalloc(sizeof(*ab), gfp_mask); 957 if (!ab) 958 goto err; 959 } 960 961 ab->skb = alloc_skb(AUDIT_BUFSIZ, gfp_mask); 962 if (!ab->skb) 963 goto err; 964 965 ab->ctx = ctx; 966 ab->gfp_mask = gfp_mask; 967 nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0)); 968 nlh->nlmsg_type = type; 969 nlh->nlmsg_flags = 0; 970 nlh->nlmsg_pid = 0; 971 nlh->nlmsg_seq = 0; 972 return ab; 973 err: 974 audit_buffer_free(ab); 975 return NULL; 976 } 977 978 /** 979 * audit_serial - compute a serial number for the audit record 980 * 981 * Compute a serial number for the audit record. Audit records are 982 * written to user-space as soon as they are generated, so a complete 983 * audit record may be written in several pieces. The timestamp of the 984 * record and this serial number are used by the user-space tools to 985 * determine which pieces belong to the same audit record. The 986 * (timestamp,serial) tuple is unique for each syscall and is live from 987 * syscall entry to syscall exit. 988 * 989 * NOTE: Another possibility is to store the formatted records off the 990 * audit context (for those records that have a context), and emit them 991 * all at syscall exit. However, this could delay the reporting of 992 * significant errors until syscall exit (or never, if the system 993 * halts). 994 */ 995 unsigned int audit_serial(void) 996 { 997 static DEFINE_SPINLOCK(serial_lock); 998 static unsigned int serial = 0; 999 1000 unsigned long flags; 1001 unsigned int ret; 1002 1003 spin_lock_irqsave(&serial_lock, flags); 1004 do { 1005 ret = ++serial; 1006 } while (unlikely(!ret)); 1007 spin_unlock_irqrestore(&serial_lock, flags); 1008 1009 return ret; 1010 } 1011 1012 static inline void audit_get_stamp(struct audit_context *ctx, 1013 struct timespec *t, unsigned int *serial) 1014 { 1015 if (ctx) 1016 auditsc_get_stamp(ctx, t, serial); 1017 else { 1018 *t = CURRENT_TIME; 1019 *serial = audit_serial(); 1020 } 1021 } 1022 1023 /* Obtain an audit buffer. This routine does locking to obtain the 1024 * audit buffer, but then no locking is required for calls to 1025 * audit_log_*format. If the tsk is a task that is currently in a 1026 * syscall, then the syscall is marked as auditable and an audit record 1027 * will be written at syscall exit. If there is no associated task, tsk 1028 * should be NULL. */ 1029 1030 /** 1031 * audit_log_start - obtain an audit buffer 1032 * @ctx: audit_context (may be NULL) 1033 * @gfp_mask: type of allocation 1034 * @type: audit message type 1035 * 1036 * Returns audit_buffer pointer on success or NULL on error. 1037 * 1038 * Obtain an audit buffer. This routine does locking to obtain the 1039 * audit buffer, but then no locking is required for calls to 1040 * audit_log_*format. If the task (ctx) is a task that is currently in a 1041 * syscall, then the syscall is marked as auditable and an audit record 1042 * will be written at syscall exit. If there is no associated task, then 1043 * task context (ctx) should be NULL. 1044 */ 1045 struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, 1046 int type) 1047 { 1048 struct audit_buffer *ab = NULL; 1049 struct timespec t; 1050 unsigned int uninitialized_var(serial); 1051 int reserve; 1052 unsigned long timeout_start = jiffies; 1053 1054 if (!audit_initialized) 1055 return NULL; 1056 1057 if (unlikely(audit_filter_type(type))) 1058 return NULL; 1059 1060 if (gfp_mask & __GFP_WAIT) 1061 reserve = 0; 1062 else 1063 reserve = 5; /* Allow atomic callers to go up to five 1064 entries over the normal backlog limit */ 1065 1066 while (audit_backlog_limit 1067 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { 1068 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time 1069 && time_before(jiffies, timeout_start + audit_backlog_wait_time)) { 1070 1071 /* Wait for auditd to drain the queue a little */ 1072 DECLARE_WAITQUEUE(wait, current); 1073 set_current_state(TASK_INTERRUPTIBLE); 1074 add_wait_queue(&audit_backlog_wait, &wait); 1075 1076 if (audit_backlog_limit && 1077 skb_queue_len(&audit_skb_queue) > audit_backlog_limit) 1078 schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies); 1079 1080 __set_current_state(TASK_RUNNING); 1081 remove_wait_queue(&audit_backlog_wait, &wait); 1082 continue; 1083 } 1084 if (audit_rate_check() && printk_ratelimit()) 1085 printk(KERN_WARNING 1086 "audit: audit_backlog=%d > " 1087 "audit_backlog_limit=%d\n", 1088 skb_queue_len(&audit_skb_queue), 1089 audit_backlog_limit); 1090 audit_log_lost("backlog limit exceeded"); 1091 audit_backlog_wait_time = audit_backlog_wait_overflow; 1092 wake_up(&audit_backlog_wait); 1093 return NULL; 1094 } 1095 1096 ab = audit_buffer_alloc(ctx, gfp_mask, type); 1097 if (!ab) { 1098 audit_log_lost("out of memory in audit_log_start"); 1099 return NULL; 1100 } 1101 1102 audit_get_stamp(ab->ctx, &t, &serial); 1103 1104 audit_log_format(ab, "audit(%lu.%03lu:%u): ", 1105 t.tv_sec, t.tv_nsec/1000000, serial); 1106 return ab; 1107 } 1108 1109 /** 1110 * audit_expand - expand skb in the audit buffer 1111 * @ab: audit_buffer 1112 * @extra: space to add at tail of the skb 1113 * 1114 * Returns 0 (no space) on failed expansion, or available space if 1115 * successful. 1116 */ 1117 static inline int audit_expand(struct audit_buffer *ab, int extra) 1118 { 1119 struct sk_buff *skb = ab->skb; 1120 int oldtail = skb_tailroom(skb); 1121 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); 1122 int newtail = skb_tailroom(skb); 1123 1124 if (ret < 0) { 1125 audit_log_lost("out of memory in audit_expand"); 1126 return 0; 1127 } 1128 1129 skb->truesize += newtail - oldtail; 1130 return newtail; 1131 } 1132 1133 /* 1134 * Format an audit message into the audit buffer. If there isn't enough 1135 * room in the audit buffer, more room will be allocated and vsnprint 1136 * will be called a second time. Currently, we assume that a printk 1137 * can't format message larger than 1024 bytes, so we don't either. 1138 */ 1139 static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, 1140 va_list args) 1141 { 1142 int len, avail; 1143 struct sk_buff *skb; 1144 va_list args2; 1145 1146 if (!ab) 1147 return; 1148 1149 BUG_ON(!ab->skb); 1150 skb = ab->skb; 1151 avail = skb_tailroom(skb); 1152 if (avail == 0) { 1153 avail = audit_expand(ab, AUDIT_BUFSIZ); 1154 if (!avail) 1155 goto out; 1156 } 1157 va_copy(args2, args); 1158 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); 1159 if (len >= avail) { 1160 /* The printk buffer is 1024 bytes long, so if we get 1161 * here and AUDIT_BUFSIZ is at least 1024, then we can 1162 * log everything that printk could have logged. */ 1163 avail = audit_expand(ab, 1164 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); 1165 if (!avail) 1166 goto out; 1167 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); 1168 } 1169 va_end(args2); 1170 if (len > 0) 1171 skb_put(skb, len); 1172 out: 1173 return; 1174 } 1175 1176 /** 1177 * audit_log_format - format a message into the audit buffer. 1178 * @ab: audit_buffer 1179 * @fmt: format string 1180 * @...: optional parameters matching @fmt string 1181 * 1182 * All the work is done in audit_log_vformat. 1183 */ 1184 void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) 1185 { 1186 va_list args; 1187 1188 if (!ab) 1189 return; 1190 va_start(args, fmt); 1191 audit_log_vformat(ab, fmt, args); 1192 va_end(args); 1193 } 1194 1195 /** 1196 * audit_log_hex - convert a buffer to hex and append it to the audit skb 1197 * @ab: the audit_buffer 1198 * @buf: buffer to convert to hex 1199 * @len: length of @buf to be converted 1200 * 1201 * No return value; failure to expand is silently ignored. 1202 * 1203 * This function will take the passed buf and convert it into a string of 1204 * ascii hex digits. The new string is placed onto the skb. 1205 */ 1206 void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, 1207 size_t len) 1208 { 1209 int i, avail, new_len; 1210 unsigned char *ptr; 1211 struct sk_buff *skb; 1212 static const unsigned char *hex = "0123456789ABCDEF"; 1213 1214 if (!ab) 1215 return; 1216 1217 BUG_ON(!ab->skb); 1218 skb = ab->skb; 1219 avail = skb_tailroom(skb); 1220 new_len = len<<1; 1221 if (new_len >= avail) { 1222 /* Round the buffer request up to the next multiple */ 1223 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); 1224 avail = audit_expand(ab, new_len); 1225 if (!avail) 1226 return; 1227 } 1228 1229 ptr = skb_tail_pointer(skb); 1230 for (i=0; i<len; i++) { 1231 *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ 1232 *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ 1233 } 1234 *ptr = 0; 1235 skb_put(skb, len << 1); /* new string is twice the old string */ 1236 } 1237 1238 /* 1239 * Format a string of no more than slen characters into the audit buffer, 1240 * enclosed in quote marks. 1241 */ 1242 static void audit_log_n_string(struct audit_buffer *ab, size_t slen, 1243 const char *string) 1244 { 1245 int avail, new_len; 1246 unsigned char *ptr; 1247 struct sk_buff *skb; 1248 1249 if (!ab) 1250 return; 1251 1252 BUG_ON(!ab->skb); 1253 skb = ab->skb; 1254 avail = skb_tailroom(skb); 1255 new_len = slen + 3; /* enclosing quotes + null terminator */ 1256 if (new_len > avail) { 1257 avail = audit_expand(ab, new_len); 1258 if (!avail) 1259 return; 1260 } 1261 ptr = skb_tail_pointer(skb); 1262 *ptr++ = '"'; 1263 memcpy(ptr, string, slen); 1264 ptr += slen; 1265 *ptr++ = '"'; 1266 *ptr = 0; 1267 skb_put(skb, slen + 2); /* don't include null terminator */ 1268 } 1269 1270 /** 1271 * audit_string_contains_control - does a string need to be logged in hex 1272 * @string: string to be checked 1273 * @len: max length of the string to check 1274 */ 1275 int audit_string_contains_control(const char *string, size_t len) 1276 { 1277 const unsigned char *p; 1278 for (p = string; p < (const unsigned char *)string + len && *p; p++) { 1279 if (*p == '"' || *p < 0x21 || *p > 0x7f) 1280 return 1; 1281 } 1282 return 0; 1283 } 1284 1285 /** 1286 * audit_log_n_untrustedstring - log a string that may contain random characters 1287 * @ab: audit_buffer 1288 * @len: length of string (not including trailing null) 1289 * @string: string to be logged 1290 * 1291 * This code will escape a string that is passed to it if the string 1292 * contains a control character, unprintable character, double quote mark, 1293 * or a space. Unescaped strings will start and end with a double quote mark. 1294 * Strings that are escaped are printed in hex (2 digits per char). 1295 * 1296 * The caller specifies the number of characters in the string to log, which may 1297 * or may not be the entire string. 1298 */ 1299 void audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, 1300 const char *string) 1301 { 1302 if (audit_string_contains_control(string, len)) 1303 audit_log_hex(ab, string, len); 1304 else 1305 audit_log_n_string(ab, len, string); 1306 } 1307 1308 /** 1309 * audit_log_untrustedstring - log a string that may contain random characters 1310 * @ab: audit_buffer 1311 * @string: string to be logged 1312 * 1313 * Same as audit_log_n_untrustedstring(), except that strlen is used to 1314 * determine string length. 1315 */ 1316 void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) 1317 { 1318 audit_log_n_untrustedstring(ab, strlen(string), string); 1319 } 1320 1321 /* This is a helper-function to print the escaped d_path */ 1322 void audit_log_d_path(struct audit_buffer *ab, const char *prefix, 1323 struct path *path) 1324 { 1325 char *p, *pathname; 1326 1327 if (prefix) 1328 audit_log_format(ab, " %s", prefix); 1329 1330 /* We will allow 11 spaces for ' (deleted)' to be appended */ 1331 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); 1332 if (!pathname) { 1333 audit_log_format(ab, "<no memory>"); 1334 return; 1335 } 1336 p = d_path(path, pathname, PATH_MAX+11); 1337 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ 1338 /* FIXME: can we save some information here? */ 1339 audit_log_format(ab, "<too long>"); 1340 } else 1341 audit_log_untrustedstring(ab, p); 1342 kfree(pathname); 1343 } 1344 1345 /** 1346 * audit_log_end - end one audit record 1347 * @ab: the audit_buffer 1348 * 1349 * The netlink_* functions cannot be called inside an irq context, so 1350 * the audit buffer is placed on a queue and a tasklet is scheduled to 1351 * remove them from the queue outside the irq context. May be called in 1352 * any context. 1353 */ 1354 void audit_log_end(struct audit_buffer *ab) 1355 { 1356 if (!ab) 1357 return; 1358 if (!audit_rate_check()) { 1359 audit_log_lost("rate limit exceeded"); 1360 } else { 1361 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); 1362 if (audit_pid) { 1363 nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); 1364 skb_queue_tail(&audit_skb_queue, ab->skb); 1365 ab->skb = NULL; 1366 wake_up_interruptible(&kauditd_wait); 1367 } else if (nlh->nlmsg_type != AUDIT_EOE) { 1368 if (printk_ratelimit()) { 1369 printk(KERN_NOTICE "type=%d %s\n", 1370 nlh->nlmsg_type, 1371 ab->skb->data + NLMSG_SPACE(0)); 1372 } else 1373 audit_log_lost("printk limit exceeded\n"); 1374 } 1375 } 1376 audit_buffer_free(ab); 1377 } 1378 1379 /** 1380 * audit_log - Log an audit record 1381 * @ctx: audit context 1382 * @gfp_mask: type of allocation 1383 * @type: audit message type 1384 * @fmt: format string to use 1385 * @...: variable parameters matching the format string 1386 * 1387 * This is a convenience function that calls audit_log_start, 1388 * audit_log_vformat, and audit_log_end. It may be called 1389 * in any context. 1390 */ 1391 void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, 1392 const char *fmt, ...) 1393 { 1394 struct audit_buffer *ab; 1395 va_list args; 1396 1397 ab = audit_log_start(ctx, gfp_mask, type); 1398 if (ab) { 1399 va_start(args, fmt); 1400 audit_log_vformat(ab, fmt, args); 1401 va_end(args); 1402 audit_log_end(ab); 1403 } 1404 } 1405 1406 EXPORT_SYMBOL(audit_log_start); 1407 EXPORT_SYMBOL(audit_log_end); 1408 EXPORT_SYMBOL(audit_log_format); 1409 EXPORT_SYMBOL(audit_log); 1410