security/apparmor/mount.c

   1 /*
   2  * AppArmor security module
   3  *
   4  * This file contains AppArmor mediation of files
   5  *
   6  * Copyright (C) 1998-2008 Novell/SUSE
   7  * Copyright 2009-2017 Canonical Ltd.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation, version 2 of the
  12  * License.
  13  */
  14
  15 #include <linux/fs.h>
  16 #include <linux/mount.h>
  17 #include <linux/namei.h>
  18 #include <uapi/linux/mount.h>
  19
  20 #include "include/apparmor.h"
  21 #include "include/audit.h"
  22 #include "include/cred.h"
  23 #include "include/domain.h"
  24 #include "include/file.h"
  25 #include "include/match.h"
  26 #include "include/mount.h"
  27 #include "include/path.h"
  28 #include "include/policy.h"
  29
  30
  31 static void audit_mnt_flags(struct audit_buffer *ab, unsigned long flags)
  32 {
  33         if (flags & MS_RDONLY)
  34                 audit_log_format(ab, "ro");
  35         else
  36                 audit_log_format(ab, "rw");
  37         if (flags & MS_NOSUID)
  38                 audit_log_format(ab, ", nosuid");
  39         if (flags & MS_NODEV)
  40                 audit_log_format(ab, ", nodev");
  41         if (flags & MS_NOEXEC)
  42                 audit_log_format(ab, ", noexec");
  43         if (flags & MS_SYNCHRONOUS)
  44                 audit_log_format(ab, ", sync");
  45         if (flags & MS_REMOUNT)
  46                 audit_log_format(ab, ", remount");
  47         if (flags & MS_MANDLOCK)
  48                 audit_log_format(ab, ", mand");
  49         if (flags & MS_DIRSYNC)
  50                 audit_log_format(ab, ", dirsync");
  51         if (flags & MS_NOATIME)
  52                 audit_log_format(ab, ", noatime");
  53         if (flags & MS_NODIRATIME)
  54                 audit_log_format(ab, ", nodiratime");
  55         if (flags & MS_BIND)
  56                 audit_log_format(ab, flags & MS_REC ? ", rbind" : ", bind");
  57         if (flags & MS_MOVE)
  58                 audit_log_format(ab, ", move");
  59         if (flags & MS_SILENT)
  60                 audit_log_format(ab, ", silent");
  61         if (flags & MS_POSIXACL)
  62                 audit_log_format(ab, ", acl");
  63         if (flags & MS_UNBINDABLE)
  64                 audit_log_format(ab, flags & MS_REC ? ", runbindable" :
  65                                  ", unbindable");
  66         if (flags & MS_PRIVATE)
  67                 audit_log_format(ab, flags & MS_REC ? ", rprivate" :
  68                                  ", private");
  69         if (flags & MS_SLAVE)
  70                 audit_log_format(ab, flags & MS_REC ? ", rslave" :
  71                                  ", slave");
  72         if (flags & MS_SHARED)
  73                 audit_log_format(ab, flags & MS_REC ? ", rshared" :
  74                                  ", shared");
  75         if (flags & MS_RELATIME)
  76                 audit_log_format(ab, ", relatime");
  77         if (flags & MS_I_VERSION)
  78                 audit_log_format(ab, ", iversion");
  79         if (flags & MS_STRICTATIME)
  80                 audit_log_format(ab, ", strictatime");
  81         if (flags & MS_NOUSER)
  82                 audit_log_format(ab, ", nouser");
  83 }
  84
  85 /**
  86  * audit_cb - call back for mount specific audit fields
  87  * @ab: audit_buffer  (NOT NULL)
  88  * @va: audit struct to audit values of  (NOT NULL)
  89  */
  90 static void audit_cb(struct audit_buffer *ab, void *va)
  91 {
  92         struct common_audit_data *sa = va;
  93
  94         if (aad(sa)->mnt.type) {
  95                 audit_log_format(ab, " fstype=");
  96                 audit_log_untrustedstring(ab, aad(sa)->mnt.type);
  97         }
  98         if (aad(sa)->mnt.src_name) {
  99                 audit_log_format(ab, " srcname=");
 100                 audit_log_untrustedstring(ab, aad(sa)->mnt.src_name);
 101         }
 102         if (aad(sa)->mnt.trans) {
 103                 audit_log_format(ab, " trans=");
 104                 audit_log_untrustedstring(ab, aad(sa)->mnt.trans);
 105         }
 106         if (aad(sa)->mnt.flags) {
 107                 audit_log_format(ab, " flags=\"");
 108                 audit_mnt_flags(ab, aad(sa)->mnt.flags);
 109                 audit_log_format(ab, "\"");
 110         }
 111         if (aad(sa)->mnt.data) {
 112                 audit_log_format(ab, " options=");
 113                 audit_log_untrustedstring(ab, aad(sa)->mnt.data);
 114         }
 115 }
 116
 117 /**
 118  * audit_mount - handle the auditing of mount operations
 119  * @profile: the profile being enforced  (NOT NULL)
 120  * @op: operation being mediated (NOT NULL)
 121  * @name: name of object being mediated (MAYBE NULL)
 122  * @src_name: src_name of object being mediated (MAYBE_NULL)
 123  * @type: type of filesystem (MAYBE_NULL)
 124  * @trans: name of trans (MAYBE NULL)
 125  * @flags: filesystem independent mount flags
 126  * @data: filesystem mount flags
 127  * @request: permissions requested
 128  * @perms: the permissions computed for the request (NOT NULL)
 129  * @info: extra information message (MAYBE NULL)
 130  * @error: 0 if operation allowed else failure error code
 131  *
 132  * Returns: %0 or error on failure
 133  */
 134 static int audit_mount(struct aa_profile *profile, const char *op,
 135                        const char *name, const char *src_name,
 136                        const char *type, const char *trans,
 137                        unsigned long flags, const void *data, u32 request,
 138                        struct aa_perms *perms, const char *info, int error)
 139 {
 140         int audit_type = AUDIT_APPARMOR_AUTO;
 141         DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op);
 142
 143         if (likely(!error)) {
 144                 u32 mask = perms->audit;
 145
 146                 if (unlikely(AUDIT_MODE(profile) == AUDIT_ALL))
 147                         mask = 0xffff;
 148
 149                 /* mask off perms that are not being force audited */
 150                 request &= mask;
 151
 152                 if (likely(!request))
 153                         return 0;
 154                 audit_type = AUDIT_APPARMOR_AUDIT;
 155         } else {
 156                 /* only report permissions that were denied */
 157                 request = request & ~perms->allow;
 158
 159                 if (request & perms->kill)
 160                         audit_type = AUDIT_APPARMOR_KILL;
 161
 162                 /* quiet known rejects, assumes quiet and kill do not overlap */
 163                 if ((request & perms->quiet) &&
 164                     AUDIT_MODE(profile) != AUDIT_NOQUIET &&
 165                     AUDIT_MODE(profile) != AUDIT_ALL)
 166                         request &= ~perms->quiet;
 167
 168                 if (!request)
 169                         return error;
 170         }
 171
 172         aad(&sa)->name = name;
 173         aad(&sa)->mnt.src_name = src_name;
 174         aad(&sa)->mnt.type = type;
 175         aad(&sa)->mnt.trans = trans;
 176         aad(&sa)->mnt.flags = flags;
 177         if (data && (perms->audit & AA_AUDIT_DATA))
 178                 aad(&sa)->mnt.data = data;
 179         aad(&sa)->info = info;
 180         aad(&sa)->error = error;
 181
 182         return aa_audit(audit_type, profile, &sa, audit_cb);
 183 }
 184
 185 /**
 186  * match_mnt_flags - Do an ordered match on mount flags
 187  * @dfa: dfa to match against
 188  * @state: state to start in
 189  * @flags: mount flags to match against
 190  *
 191  * Mount flags are encoded as an ordered match. This is done instead of
 192  * checking against a simple bitmask, to allow for logical operations
 193  * on the flags.
 194  *
 195  * Returns: next state after flags match
 196  */
 197 static unsigned int match_mnt_flags(struct aa_dfa *dfa, unsigned int state,
 198                                     unsigned long flags)
 199 {
 200         unsigned int i;
 201
 202         for (i = 0; i <= 31 ; ++i) {
 203                 if ((1 << i) & flags)
 204                         state = aa_dfa_next(dfa, state, i + 1);
 205         }
 206
 207         return state;
 208 }
 209
 210 /**
 211  * compute_mnt_perms - compute mount permission associated with @state
 212  * @dfa: dfa to match against (NOT NULL)
 213  * @state: state match finished in
 214  *
 215  * Returns: mount permissions
 216  */
 217 static struct aa_perms compute_mnt_perms(struct aa_dfa *dfa,
 218                                            unsigned int state)
 219 {
 220         struct aa_perms perms = {
 221                 .allow = dfa_user_allow(dfa, state),
 222                 .audit = dfa_user_audit(dfa, state),
 223                 .quiet = dfa_user_quiet(dfa, state),
 224                 .xindex = dfa_user_xindex(dfa, state),
 225         };
 226
 227         return perms;
 228 }
 229
 230 static const char * const mnt_info_table[] = {
 231         "match succeeded",
 232         "failed mntpnt match",
 233         "failed srcname match",
 234         "failed type match",
 235         "failed flags match",
 236         "failed data match"
 237 };
 238
 239 /*
 240  * Returns 0 on success else element that match failed in, this is the
 241  * index into the mnt_info_table above
 242  */
 243 static int do_match_mnt(struct aa_dfa *dfa, unsigned int start,
 244                         const char *mntpnt, const char *devname,
 245                         const char *type, unsigned long flags,
 246                         void *data, bool binary, struct aa_perms *perms)
 247 {
 248         unsigned int state;
 249
 250         AA_BUG(!dfa);
 251         AA_BUG(!perms);
 252
 253         state = aa_dfa_match(dfa, start, mntpnt);
 254         state = aa_dfa_null_transition(dfa, state);
 255         if (!state)
 256                 return 1;
 257
 258         if (devname)
 259                 state = aa_dfa_match(dfa, state, devname);
 260         state = aa_dfa_null_transition(dfa, state);
 261         if (!state)
 262                 return 2;
 263
 264         if (type)
 265                 state = aa_dfa_match(dfa, state, type);
 266         state = aa_dfa_null_transition(dfa, state);
 267         if (!state)
 268                 return 3;
 269
 270         state = match_mnt_flags(dfa, state, flags);
 271         if (!state)
 272                 return 4;
 273         *perms = compute_mnt_perms(dfa, state);
 274         if (perms->allow & AA_MAY_MOUNT)
 275                 return 0;
 276
 277         /* only match data if not binary and the DFA flags data is expected */
 278         if (data && !binary && (perms->allow & AA_MNT_CONT_MATCH)) {
 279                 state = aa_dfa_null_transition(dfa, state);
 280                 if (!state)
 281                         return 4;
 282
 283                 state = aa_dfa_match(dfa, state, data);
 284                 if (!state)
 285                         return 5;
 286                 *perms = compute_mnt_perms(dfa, state);
 287                 if (perms->allow & AA_MAY_MOUNT)
 288                         return 0;
 289         }
 290
 291         /* failed at end of flags match */
 292         return 4;
 293 }
 294
 295
 296 static int path_flags(struct aa_profile *profile, const struct path *path)
 297 {
 298         AA_BUG(!profile);
 299         AA_BUG(!path);
 300
 301         return profile->path_flags |
 302                 (S_ISDIR(path->dentry->d_inode->i_mode) ? PATH_IS_DIR : 0);
 303 }
 304
 305 /**
 306  * match_mnt_path_str - handle path matching for mount
 307  * @profile: the confining profile
 308  * @mntpath: for the mntpnt (NOT NULL)
 309  * @buffer: buffer to be used to lookup mntpath
 310  * @devnme: string for the devname/src_name (MAY BE NULL OR ERRPTR)
 311  * @type: string for the dev type (MAYBE NULL)
 312  * @flags: mount flags to match
 313  * @data: fs mount data (MAYBE NULL)
 314  * @binary: whether @data is binary
 315  * @devinfo: error str if (IS_ERR(@devname))
 316  *
 317  * Returns: 0 on success else error
 318  */
 319 static int match_mnt_path_str(struct aa_profile *profile,
 320                               const struct path *mntpath, char *buffer,
 321                               const char *devname, const char *type,
 322                               unsigned long flags, void *data, bool binary,
 323                               const char *devinfo)
 324 {
 325         struct aa_perms perms = { };
 326         const char *mntpnt = NULL, *info = NULL;
 327         int pos, error;
 328
 329         AA_BUG(!profile);
 330         AA_BUG(!mntpath);
 331         AA_BUG(!buffer);
 332
 333         if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 334                 return 0;
 335
 336         error = aa_path_name(mntpath, path_flags(profile, mntpath), buffer,
 337                              &mntpnt, &info, profile->disconnected);
 338         if (error)
 339                 goto audit;
 340         if (IS_ERR(devname)) {
 341                 error = PTR_ERR(devname);
 342                 devname = NULL;
 343                 info = devinfo;
 344                 goto audit;
 345         }
 346
 347         error = -EACCES;
 348         pos = do_match_mnt(profile->policy.dfa,
 349                            profile->policy.start[AA_CLASS_MOUNT],
 350                            mntpnt, devname, type, flags, data, binary, &perms);
 351         if (pos) {
 352                 info = mnt_info_table[pos];
 353                 goto audit;
 354         }
 355         error = 0;
 356
 357 audit:
 358         return audit_mount(profile, OP_MOUNT, mntpnt, devname, type, NULL,
 359                            flags, data, AA_MAY_MOUNT, &perms, info, error);
 360 }
 361
 362 /**
 363  * match_mnt - handle path matching for mount
 364  * @profile: the confining profile
 365  * @mntpath: for the mntpnt (NOT NULL)
 366  * @buffer: buffer to be used to lookup mntpath
 367  * @devpath: path devname/src_name (MAYBE NULL)
 368  * @devbuffer: buffer to be used to lookup devname/src_name
 369  * @type: string for the dev type (MAYBE NULL)
 370  * @flags: mount flags to match
 371  * @data: fs mount data (MAYBE NULL)
 372  * @binary: whether @data is binary
 373  *
 374  * Returns: 0 on success else error
 375  */
 376 static int match_mnt(struct aa_profile *profile, const struct path *path,
 377                      char *buffer, struct path *devpath, char *devbuffer,
 378                      const char *type, unsigned long flags, void *data,
 379                      bool binary)
 380 {
 381         const char *devname = NULL, *info = NULL;
 382         int error = -EACCES;
 383
 384         AA_BUG(!profile);
 385         AA_BUG(devpath && !devbuffer);
 386
 387         if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 388                 return 0;
 389
 390         if (devpath) {
 391                 error = aa_path_name(devpath, path_flags(profile, devpath),
 392                                      devbuffer, &devname, &info,
 393                                      profile->disconnected);
 394                 if (error)
 395                         devname = ERR_PTR(error);
 396         }
 397
 398         return match_mnt_path_str(profile, path, buffer, devname, type, flags,
 399                                   data, binary, info);
 400 }
 401
 402 int aa_remount(struct aa_label *label, const struct path *path,
 403                unsigned long flags, void *data)
 404 {
 405         struct aa_profile *profile;
 406         char *buffer = NULL;
 407         bool binary;
 408         int error;
 409
 410         AA_BUG(!label);
 411         AA_BUG(!path);
 412
 413         binary = path->dentry->d_sb->s_type->fs_flags & FS_BINARY_MOUNTDATA;
 414
 415         get_buffers(buffer);
 416         error = fn_for_each_confined(label, profile,
 417                         match_mnt(profile, path, buffer, NULL, NULL, NULL,
 418                                   flags, data, binary));
 419         put_buffers(buffer);
 420
 421         return error;
 422 }
 423
 424 int aa_bind_mount(struct aa_label *label, const struct path *path,
 425                   const char *dev_name, unsigned long flags)
 426 {
 427         struct aa_profile *profile;
 428         char *buffer = NULL, *old_buffer = NULL;
 429         struct path old_path;
 430         int error;
 431
 432         AA_BUG(!label);
 433         AA_BUG(!path);
 434
 435         if (!dev_name || !*dev_name)
 436                 return -EINVAL;
 437
 438         flags &= MS_REC | MS_BIND;
 439
 440         error = kern_path(dev_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path);
 441         if (error)
 442                 return error;
 443
 444         get_buffers(buffer, old_buffer);
 445         error = fn_for_each_confined(label, profile,
 446                         match_mnt(profile, path, buffer, &old_path, old_buffer,
 447                                   NULL, flags, NULL, false));
 448         put_buffers(buffer, old_buffer);
 449         path_put(&old_path);
 450
 451         return error;
 452 }
 453
 454 int aa_mount_change_type(struct aa_label *label, const struct path *path,
 455                          unsigned long flags)
 456 {
 457         struct aa_profile *profile;
 458         char *buffer = NULL;
 459         int error;
 460
 461         AA_BUG(!label);
 462         AA_BUG(!path);
 463
 464         /* These are the flags allowed by do_change_type() */
 465         flags &= (MS_REC | MS_SILENT | MS_SHARED | MS_PRIVATE | MS_SLAVE |
 466                   MS_UNBINDABLE);
 467
 468         get_buffers(buffer);
 469         error = fn_for_each_confined(label, profile,
 470                         match_mnt(profile, path, buffer, NULL, NULL, NULL,
 471                                   flags, NULL, false));
 472         put_buffers(buffer);
 473
 474         return error;
 475 }
 476
 477 int aa_move_mount(struct aa_label *label, const struct path *path,
 478                   const char *orig_name)
 479 {
 480         struct aa_profile *profile;
 481         char *buffer = NULL, *old_buffer = NULL;
 482         struct path old_path;
 483         int error;
 484
 485         AA_BUG(!label);
 486         AA_BUG(!path);
 487
 488         if (!orig_name || !*orig_name)
 489                 return -EINVAL;
 490
 491         error = kern_path(orig_name, LOOKUP_FOLLOW, &old_path);
 492         if (error)
 493                 return error;
 494
 495         get_buffers(buffer, old_buffer);
 496         error = fn_for_each_confined(label, profile,
 497                         match_mnt(profile, path, buffer, &old_path, old_buffer,
 498                                   NULL, MS_MOVE, NULL, false));
 499         put_buffers(buffer, old_buffer);
 500         path_put(&old_path);
 501
 502         return error;
 503 }
 504
 505 int aa_new_mount(struct aa_label *label, const char *dev_name,
 506                  const struct path *path, const char *type, unsigned long flags,
 507                  void *data)
 508 {
 509         struct aa_profile *profile;
 510         char *buffer = NULL, *dev_buffer = NULL;
 511         bool binary = true;
 512         int error;
 513         int requires_dev = 0;
 514         struct path tmp_path, *dev_path = NULL;
 515
 516         AA_BUG(!label);
 517         AA_BUG(!path);
 518
 519         if (type) {
 520                 struct file_system_type *fstype;
 521
 522                 fstype = get_fs_type(type);
 523                 if (!fstype)
 524                         return -ENODEV;
 525                 binary = fstype->fs_flags & FS_BINARY_MOUNTDATA;
 526                 requires_dev = fstype->fs_flags & FS_REQUIRES_DEV;
 527                 put_filesystem(fstype);
 528
 529                 if (requires_dev) {
 530                         if (!dev_name || !*dev_name)
 531                                 return -ENOENT;
 532
 533                         error = kern_path(dev_name, LOOKUP_FOLLOW, &tmp_path);
 534                         if (error)
 535                                 return error;
 536                         dev_path = &tmp_path;
 537                 }
 538         }
 539
 540         get_buffers(buffer, dev_buffer);
 541         if (dev_path) {
 542                 error = fn_for_each_confined(label, profile,
 543                         match_mnt(profile, path, buffer, dev_path, dev_buffer,
 544                                   type, flags, data, binary));
 545         } else {
 546                 error = fn_for_each_confined(label, profile,
 547                         match_mnt_path_str(profile, path, buffer, dev_name,
 548                                            type, flags, data, binary, NULL));
 549         }
 550         put_buffers(buffer, dev_buffer);
 551         if (dev_path)
 552                 path_put(dev_path);
 553
 554         return error;
 555 }
 556
 557 static int profile_umount(struct aa_profile *profile, struct path *path,
 558                           char *buffer)
 559 {
 560         struct aa_perms perms = { };
 561         const char *name = NULL, *info = NULL;
 562         unsigned int state;
 563         int error;
 564
 565         AA_BUG(!profile);
 566         AA_BUG(!path);
 567
 568         if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 569                 return 0;
 570
 571         error = aa_path_name(path, path_flags(profile, path), buffer, &name,
 572                              &info, profile->disconnected);
 573         if (error)
 574                 goto audit;
 575
 576         state = aa_dfa_match(profile->policy.dfa,
 577                              profile->policy.start[AA_CLASS_MOUNT],
 578                              name);
 579         perms = compute_mnt_perms(profile->policy.dfa, state);
 580         if (AA_MAY_UMOUNT & ~perms.allow)
 581                 error = -EACCES;
 582
 583 audit:
 584         return audit_mount(profile, OP_UMOUNT, name, NULL, NULL, NULL, 0, NULL,
 585                            AA_MAY_UMOUNT, &perms, info, error);
 586 }
 587
 588 int aa_umount(struct aa_label *label, struct vfsmount *mnt, int flags)
 589 {
 590         struct aa_profile *profile;
 591         char *buffer = NULL;
 592         int error;
 593         struct path path = { .mnt = mnt, .dentry = mnt->mnt_root };
 594
 595         AA_BUG(!label);
 596         AA_BUG(!mnt);
 597
 598         get_buffers(buffer);
 599         error = fn_for_each_confined(label, profile,
 600                         profile_umount(profile, &path, buffer));
 601         put_buffers(buffer);
 602
 603         return error;
 604 }
 605
 606 /* helper fn for transition on pivotroot
 607  *
 608  * Returns: label for transition or ERR_PTR. Does not return NULL
 609  */
 610 static struct aa_label *build_pivotroot(struct aa_profile *profile,
 611                                         const struct path *new_path,
 612                                         char *new_buffer,
 613                                         const struct path *old_path,
 614                                         char *old_buffer)
 615 {
 616         const char *old_name, *new_name = NULL, *info = NULL;
 617         const char *trans_name = NULL;
 618         struct aa_perms perms = { };
 619         unsigned int state;
 620         int error;
 621
 622         AA_BUG(!profile);
 623         AA_BUG(!new_path);
 624         AA_BUG(!old_path);
 625
 626         if (profile_unconfined(profile) ||
 627             !PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 628                 return aa_get_newest_label(&profile->label);
 629
 630         error = aa_path_name(old_path, path_flags(profile, old_path),
 631                              old_buffer, &old_name, &info,
 632                              profile->disconnected);
 633         if (error)
 634                 goto audit;
 635         error = aa_path_name(new_path, path_flags(profile, new_path),
 636                              new_buffer, &new_name, &info,
 637                              profile->disconnected);
 638         if (error)
 639                 goto audit;
 640
 641         error = -EACCES;
 642         state = aa_dfa_match(profile->policy.dfa,
 643                              profile->policy.start[AA_CLASS_MOUNT],
 644                              new_name);
 645         state = aa_dfa_null_transition(profile->policy.dfa, state);
 646         state = aa_dfa_match(profile->policy.dfa, state, old_name);
 647         perms = compute_mnt_perms(profile->policy.dfa, state);
 648
 649         if (AA_MAY_PIVOTROOT & perms.allow)
 650                 error = 0;
 651
 652 audit:
 653         error = audit_mount(profile, OP_PIVOTROOT, new_name, old_name,
 654                             NULL, trans_name, 0, NULL, AA_MAY_PIVOTROOT,
 655                             &perms, info, error);
 656         if (error)
 657                 return ERR_PTR(error);
 658
 659         return aa_get_newest_label(&profile->label);
 660 }
 661
 662 int aa_pivotroot(struct aa_label *label, const struct path *old_path,
 663                  const struct path *new_path)
 664 {
 665         struct aa_profile *profile;
 666         struct aa_label *target = NULL;
 667         char *old_buffer = NULL, *new_buffer = NULL, *info = NULL;
 668         int error;
 669
 670         AA_BUG(!label);
 671         AA_BUG(!old_path);
 672         AA_BUG(!new_path);
 673
 674         get_buffers(old_buffer, new_buffer);
 675         target = fn_label_build(label, profile, GFP_ATOMIC,
 676                         build_pivotroot(profile, new_path, new_buffer,
 677                                         old_path, old_buffer));
 678         if (!target) {
 679                 info = "label build failed";
 680                 error = -ENOMEM;
 681                 goto fail;
 682         } else if (!IS_ERR(target)) {
 683                 error = aa_replace_current_label(target);
 684                 if (error) {
 685                         /* TODO: audit target */
 686                         aa_put_label(target);
 687                         goto out;
 688                 }
 689         } else
 690                 /* already audited error */
 691                 error = PTR_ERR(target);
 692 out:
 693         put_buffers(old_buffer, new_buffer);
 694
 695         return error;
 696
 697 fail:
 698         /* TODO: add back in auditing of new_name and old_name */
 699         error = fn_for_each(label, profile,
 700                         audit_mount(profile, OP_PIVOTROOT, NULL /*new_name */,
 701                                     NULL /* old_name */,
 702                                     NULL, NULL,
 703                                     0, NULL, AA_MAY_PIVOTROOT, &nullperms, info,
 704                                     error));
 705         goto out;
 706 }