kernel/audit.c

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