security/apparmor/mount.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AppArmor security module
   4  *
   5  * This file contains AppArmor mediation of files
   6  *
   7  * Copyright (C) 1998-2008 Novell/SUSE
   8  * Copyright 2009-2017 Canonical Ltd.
   9  */
  10
  11 #include <linux/fs.h>
  12 #include <linux/mount.h>
  13 #include <linux/namei.h>
  14 #include <uapi/linux/mount.h>
  15
  16 #include "include/apparmor.h"
  17 #include "include/audit.h"
  18 #include "include/cred.h"
  19 #include "include/domain.h"
  20 #include "include/file.h"
  21 #include "include/match.h"
  22 #include "include/mount.h"
  23 #include "include/path.h"
  24 #include "include/policy.h"
  25
  26
  27 static void audit_mnt_flags(struct audit_buffer *ab, unsigned long flags)
  28 {
  29         if (flags & MS_RDONLY)
  30                 audit_log_format(ab, "ro");
  31         else
  32                 audit_log_format(ab, "rw");
  33         if (flags & MS_NOSUID)
  34                 audit_log_format(ab, ", nosuid");
  35         if (flags & MS_NODEV)
  36                 audit_log_format(ab, ", nodev");
  37         if (flags & MS_NOEXEC)
  38                 audit_log_format(ab, ", noexec");
  39         if (flags & MS_SYNCHRONOUS)
  40                 audit_log_format(ab, ", sync");
  41         if (flags & MS_REMOUNT)
  42                 audit_log_format(ab, ", remount");
  43         if (flags & MS_MANDLOCK)
  44                 audit_log_format(ab, ", mand");
  45         if (flags & MS_DIRSYNC)
  46                 audit_log_format(ab, ", dirsync");
  47         if (flags & MS_NOATIME)
  48                 audit_log_format(ab, ", noatime");
  49         if (flags & MS_NODIRATIME)
  50                 audit_log_format(ab, ", nodiratime");
  51         if (flags & MS_BIND)
  52                 audit_log_format(ab, flags & MS_REC ? ", rbind" : ", bind");
  53         if (flags & MS_MOVE)
  54                 audit_log_format(ab, ", move");
  55         if (flags & MS_SILENT)
  56                 audit_log_format(ab, ", silent");
  57         if (flags & MS_POSIXACL)
  58                 audit_log_format(ab, ", acl");
  59         if (flags & MS_UNBINDABLE)
  60                 audit_log_format(ab, flags & MS_REC ? ", runbindable" :
  61                                  ", unbindable");
  62         if (flags & MS_PRIVATE)
  63                 audit_log_format(ab, flags & MS_REC ? ", rprivate" :
  64                                  ", private");
  65         if (flags & MS_SLAVE)
  66                 audit_log_format(ab, flags & MS_REC ? ", rslave" :
  67                                  ", slave");
  68         if (flags & MS_SHARED)
  69                 audit_log_format(ab, flags & MS_REC ? ", rshared" :
  70                                  ", shared");
  71         if (flags & MS_RELATIME)
  72                 audit_log_format(ab, ", relatime");
  73         if (flags & MS_I_VERSION)
  74                 audit_log_format(ab, ", iversion");
  75         if (flags & MS_STRICTATIME)
  76                 audit_log_format(ab, ", strictatime");
  77         if (flags & MS_NOUSER)
  78                 audit_log_format(ab, ", nouser");
  79 }
  80
  81 /**
  82  * audit_cb - call back for mount specific audit fields
  83  * @ab: audit_buffer  (NOT NULL)
  84  * @va: audit struct to audit values of  (NOT NULL)
  85  */
  86 static void audit_cb(struct audit_buffer *ab, void *va)
  87 {
  88         struct common_audit_data *sa = va;
  89
  90         if (aad(sa)->mnt.type) {
  91                 audit_log_format(ab, " fstype=");
  92                 audit_log_untrustedstring(ab, aad(sa)->mnt.type);
  93         }
  94         if (aad(sa)->mnt.src_name) {
  95                 audit_log_format(ab, " srcname=");
  96                 audit_log_untrustedstring(ab, aad(sa)->mnt.src_name);
  97         }
  98         if (aad(sa)->mnt.trans) {
  99                 audit_log_format(ab, " trans=");
 100                 audit_log_untrustedstring(ab, aad(sa)->mnt.trans);
 101         }
 102         if (aad(sa)->mnt.flags) {
 103                 audit_log_format(ab, " flags=\"");
 104                 audit_mnt_flags(ab, aad(sa)->mnt.flags);
 105                 audit_log_format(ab, "\"");
 106         }
 107         if (aad(sa)->mnt.data) {
 108                 audit_log_format(ab, " options=");
 109                 audit_log_untrustedstring(ab, aad(sa)->mnt.data);
 110         }
 111 }
 112
 113 /**
 114  * audit_mount - handle the auditing of mount operations
 115  * @profile: the profile being enforced  (NOT NULL)
 116  * @op: operation being mediated (NOT NULL)
 117  * @name: name of object being mediated (MAYBE NULL)
 118  * @src_name: src_name of object being mediated (MAYBE_NULL)
 119  * @type: type of filesystem (MAYBE_NULL)
 120  * @trans: name of trans (MAYBE NULL)
 121  * @flags: filesystem independent mount flags
 122  * @data: filesystem mount flags
 123  * @request: permissions requested
 124  * @perms: the permissions computed for the request (NOT NULL)
 125  * @info: extra information message (MAYBE NULL)
 126  * @error: 0 if operation allowed else failure error code
 127  *
 128  * Returns: %0 or error on failure
 129  */
 130 static int audit_mount(struct aa_profile *profile, const char *op,
 131                        const char *name, const char *src_name,
 132                        const char *type, const char *trans,
 133                        unsigned long flags, const void *data, u32 request,
 134                        struct aa_perms *perms, const char *info, int error)
 135 {
 136         int audit_type = AUDIT_APPARMOR_AUTO;
 137         DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, op);
 138
 139         if (likely(!error)) {
 140                 u32 mask = perms->audit;
 141
 142                 if (unlikely(AUDIT_MODE(profile) == AUDIT_ALL))
 143                         mask = 0xffff;
 144
 145                 /* mask off perms that are not being force audited */
 146                 request &= mask;
 147
 148                 if (likely(!request))
 149                         return 0;
 150                 audit_type = AUDIT_APPARMOR_AUDIT;
 151         } else {
 152                 /* only report permissions that were denied */
 153                 request = request & ~perms->allow;
 154
 155                 if (request & perms->kill)
 156                         audit_type = AUDIT_APPARMOR_KILL;
 157
 158                 /* quiet known rejects, assumes quiet and kill do not overlap */
 159                 if ((request & perms->quiet) &&
 160                     AUDIT_MODE(profile) != AUDIT_NOQUIET &&
 161                     AUDIT_MODE(profile) != AUDIT_ALL)
 162                         request &= ~perms->quiet;
 163
 164                 if (!request)
 165                         return error;
 166         }
 167
 168         aad(&sa)->name = name;
 169         aad(&sa)->mnt.src_name = src_name;
 170         aad(&sa)->mnt.type = type;
 171         aad(&sa)->mnt.trans = trans;
 172         aad(&sa)->mnt.flags = flags;
 173         if (data && (perms->audit & AA_AUDIT_DATA))
 174                 aad(&sa)->mnt.data = data;
 175         aad(&sa)->info = info;
 176         aad(&sa)->error = error;
 177
 178         return aa_audit(audit_type, profile, &sa, audit_cb);
 179 }
 180
 181 /**
 182  * match_mnt_flags - Do an ordered match on mount flags
 183  * @dfa: dfa to match against
 184  * @state: state to start in
 185  * @flags: mount flags to match against
 186  *
 187  * Mount flags are encoded as an ordered match. This is done instead of
 188  * checking against a simple bitmask, to allow for logical operations
 189  * on the flags.
 190  *
 191  * Returns: next state after flags match
 192  */
 193 static unsigned int match_mnt_flags(struct aa_dfa *dfa, unsigned int state,
 194                                     unsigned long flags)
 195 {
 196         unsigned int i;
 197
 198         for (i = 0; i <= 31 ; ++i) {
 199                 if ((1 << i) & flags)
 200                         state = aa_dfa_next(dfa, state, i + 1);
 201         }
 202
 203         return state;
 204 }
 205
 206 /**
 207  * compute_mnt_perms - compute mount permission associated with @state
 208  * @dfa: dfa to match against (NOT NULL)
 209  * @state: state match finished in
 210  *
 211  * Returns: mount permissions
 212  */
 213 static struct aa_perms compute_mnt_perms(struct aa_dfa *dfa,
 214                                            unsigned int state)
 215 {
 216         struct aa_perms perms = {
 217                 .allow = dfa_user_allow(dfa, state),
 218                 .audit = dfa_user_audit(dfa, state),
 219                 .quiet = dfa_user_quiet(dfa, state),
 220                 .xindex = dfa_user_xindex(dfa, state),
 221         };
 222
 223         return perms;
 224 }
 225
 226 static const char * const mnt_info_table[] = {
 227         "match succeeded",
 228         "failed mntpnt match",
 229         "failed srcname match",
 230         "failed type match",
 231         "failed flags match",
 232         "failed data match"
 233 };
 234
 235 /*
 236  * Returns 0 on success else element that match failed in, this is the
 237  * index into the mnt_info_table above
 238  */
 239 static int do_match_mnt(struct aa_dfa *dfa, unsigned int start,
 240                         const char *mntpnt, const char *devname,
 241                         const char *type, unsigned long flags,
 242                         void *data, bool binary, struct aa_perms *perms)
 243 {
 244         unsigned int state;
 245
 246         AA_BUG(!dfa);
 247         AA_BUG(!perms);
 248
 249         state = aa_dfa_match(dfa, start, mntpnt);
 250         state = aa_dfa_null_transition(dfa, state);
 251         if (!state)
 252                 return 1;
 253
 254         if (devname)
 255                 state = aa_dfa_match(dfa, state, devname);
 256         state = aa_dfa_null_transition(dfa, state);
 257         if (!state)
 258                 return 2;
 259
 260         if (type)
 261                 state = aa_dfa_match(dfa, state, type);
 262         state = aa_dfa_null_transition(dfa, state);
 263         if (!state)
 264                 return 3;
 265
 266         state = match_mnt_flags(dfa, state, flags);
 267         if (!state)
 268                 return 4;
 269         *perms = compute_mnt_perms(dfa, state);
 270         if (perms->allow & AA_MAY_MOUNT)
 271                 return 0;
 272
 273         /* only match data if not binary and the DFA flags data is expected */
 274         if (data && !binary && (perms->allow & AA_MNT_CONT_MATCH)) {
 275                 state = aa_dfa_null_transition(dfa, state);
 276                 if (!state)
 277                         return 4;
 278
 279                 state = aa_dfa_match(dfa, state, data);
 280                 if (!state)
 281                         return 5;
 282                 *perms = compute_mnt_perms(dfa, state);
 283                 if (perms->allow & AA_MAY_MOUNT)
 284                         return 0;
 285         }
 286
 287         /* failed at end of flags match */
 288         return 4;
 289 }
 290
 291
 292 static int path_flags(struct aa_profile *profile, const struct path *path)
 293 {
 294         AA_BUG(!profile);
 295         AA_BUG(!path);
 296
 297         return profile->path_flags |
 298                 (S_ISDIR(path->dentry->d_inode->i_mode) ? PATH_IS_DIR : 0);
 299 }
 300
 301 /**
 302  * match_mnt_path_str - handle path matching for mount
 303  * @profile: the confining profile
 304  * @mntpath: for the mntpnt (NOT NULL)
 305  * @buffer: buffer to be used to lookup mntpath
 306  * @devnme: string for the devname/src_name (MAY BE NULL OR ERRPTR)
 307  * @type: string for the dev type (MAYBE NULL)
 308  * @flags: mount flags to match
 309  * @data: fs mount data (MAYBE NULL)
 310  * @binary: whether @data is binary
 311  * @devinfo: error str if (IS_ERR(@devname))
 312  *
 313  * Returns: 0 on success else error
 314  */
 315 static int match_mnt_path_str(struct aa_profile *profile,
 316                               const struct path *mntpath, char *buffer,
 317                               const char *devname, const char *type,
 318                               unsigned long flags, void *data, bool binary,
 319                               const char *devinfo)
 320 {
 321         struct aa_perms perms = { };
 322         const char *mntpnt = NULL, *info = NULL;
 323         int pos, error;
 324
 325         AA_BUG(!profile);
 326         AA_BUG(!mntpath);
 327         AA_BUG(!buffer);
 328
 329         if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 330                 return 0;
 331
 332         error = aa_path_name(mntpath, path_flags(profile, mntpath), buffer,
 333                              &mntpnt, &info, profile->disconnected);
 334         if (error)
 335                 goto audit;
 336         if (IS_ERR(devname)) {
 337                 error = PTR_ERR(devname);
 338                 devname = NULL;
 339                 info = devinfo;
 340                 goto audit;
 341         }
 342
 343         error = -EACCES;
 344         pos = do_match_mnt(profile->policy.dfa,
 345                            profile->policy.start[AA_CLASS_MOUNT],
 346                            mntpnt, devname, type, flags, data, binary, &perms);
 347         if (pos) {
 348                 info = mnt_info_table[pos];
 349                 goto audit;
 350         }
 351         error = 0;
 352
 353 audit:
 354         return audit_mount(profile, OP_MOUNT, mntpnt, devname, type, NULL,
 355                            flags, data, AA_MAY_MOUNT, &perms, info, error);
 356 }
 357
 358 /**
 359  * match_mnt - handle path matching for mount
 360  * @profile: the confining profile
 361  * @mntpath: for the mntpnt (NOT NULL)
 362  * @buffer: buffer to be used to lookup mntpath
 363  * @devpath: path devname/src_name (MAYBE NULL)
 364  * @devbuffer: buffer to be used to lookup devname/src_name
 365  * @type: string for the dev type (MAYBE NULL)
 366  * @flags: mount flags to match
 367  * @data: fs mount data (MAYBE NULL)
 368  * @binary: whether @data is binary
 369  *
 370  * Returns: 0 on success else error
 371  */
 372 static int match_mnt(struct aa_profile *profile, const struct path *path,
 373                      char *buffer, struct path *devpath, char *devbuffer,
 374                      const char *type, unsigned long flags, void *data,
 375                      bool binary)
 376 {
 377         const char *devname = NULL, *info = NULL;
 378         int error = -EACCES;
 379
 380         AA_BUG(!profile);
 381         AA_BUG(devpath && !devbuffer);
 382
 383         if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 384                 return 0;
 385
 386         if (devpath) {
 387                 error = aa_path_name(devpath, path_flags(profile, devpath),
 388                                      devbuffer, &devname, &info,
 389                                      profile->disconnected);
 390                 if (error)
 391                         devname = ERR_PTR(error);
 392         }
 393
 394         return match_mnt_path_str(profile, path, buffer, devname, type, flags,
 395                                   data, binary, info);
 396 }
 397
 398 int aa_remount(struct aa_label *label, const struct path *path,
 399                unsigned long flags, void *data)
 400 {
 401         struct aa_profile *profile;
 402         char *buffer = NULL;
 403         bool binary;
 404         int error;
 405
 406         AA_BUG(!label);
 407         AA_BUG(!path);
 408
 409         binary = path->dentry->d_sb->s_type->fs_flags & FS_BINARY_MOUNTDATA;
 410
 411         buffer = aa_get_buffer(false);
 412         if (!buffer)
 413                 return -ENOMEM;
 414         error = fn_for_each_confined(label, profile,
 415                         match_mnt(profile, path, buffer, NULL, NULL, NULL,
 416                                   flags, data, binary));
 417         aa_put_buffer(buffer);
 418
 419         return error;
 420 }
 421
 422 int aa_bind_mount(struct aa_label *label, const struct path *path,
 423                   const char *dev_name, unsigned long flags)
 424 {
 425         struct aa_profile *profile;
 426         char *buffer = NULL, *old_buffer = NULL;
 427         struct path old_path;
 428         int error;
 429
 430         AA_BUG(!label);
 431         AA_BUG(!path);
 432
 433         if (!dev_name || !*dev_name)
 434                 return -EINVAL;
 435
 436         flags &= MS_REC | MS_BIND;
 437
 438         error = kern_path(dev_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path);
 439         if (error)
 440                 return error;
 441
 442         buffer = aa_get_buffer(false);
 443         old_buffer = aa_get_buffer(false);
 444         error = -ENOMEM;
 445         if (!buffer || !old_buffer)
 446                 goto out;
 447
 448         error = fn_for_each_confined(label, profile,
 449                         match_mnt(profile, path, buffer, &old_path, old_buffer,
 450                                   NULL, flags, NULL, false));
 451 out:
 452         aa_put_buffer(buffer);
 453         aa_put_buffer(old_buffer);
 454         path_put(&old_path);
 455
 456         return error;
 457 }
 458
 459 int aa_mount_change_type(struct aa_label *label, const struct path *path,
 460                          unsigned long flags)
 461 {
 462         struct aa_profile *profile;
 463         char *buffer = NULL;
 464         int error;
 465
 466         AA_BUG(!label);
 467         AA_BUG(!path);
 468
 469         /* These are the flags allowed by do_change_type() */
 470         flags &= (MS_REC | MS_SILENT | MS_SHARED | MS_PRIVATE | MS_SLAVE |
 471                   MS_UNBINDABLE);
 472
 473         buffer = aa_get_buffer(false);
 474         if (!buffer)
 475                 return -ENOMEM;
 476         error = fn_for_each_confined(label, profile,
 477                         match_mnt(profile, path, buffer, NULL, NULL, NULL,
 478                                   flags, NULL, false));
 479         aa_put_buffer(buffer);
 480
 481         return error;
 482 }
 483
 484 int aa_move_mount(struct aa_label *label, const struct path *path,
 485                   const char *orig_name)
 486 {
 487         struct aa_profile *profile;
 488         char *buffer = NULL, *old_buffer = NULL;
 489         struct path old_path;
 490         int error;
 491
 492         AA_BUG(!label);
 493         AA_BUG(!path);
 494
 495         if (!orig_name || !*orig_name)
 496                 return -EINVAL;
 497
 498         error = kern_path(orig_name, LOOKUP_FOLLOW, &old_path);
 499         if (error)
 500                 return error;
 501
 502         buffer = aa_get_buffer(false);
 503         old_buffer = aa_get_buffer(false);
 504         error = -ENOMEM;
 505         if (!buffer || !old_buffer)
 506                 goto out;
 507         error = fn_for_each_confined(label, profile,
 508                         match_mnt(profile, path, buffer, &old_path, old_buffer,
 509                                   NULL, MS_MOVE, NULL, false));
 510 out:
 511         aa_put_buffer(buffer);
 512         aa_put_buffer(old_buffer);
 513         path_put(&old_path);
 514
 515         return error;
 516 }
 517
 518 int aa_new_mount(struct aa_label *label, const char *dev_name,
 519                  const struct path *path, const char *type, unsigned long flags,
 520                  void *data)
 521 {
 522         struct aa_profile *profile;
 523         char *buffer = NULL, *dev_buffer = NULL;
 524         bool binary = true;
 525         int error;
 526         int requires_dev = 0;
 527         struct path tmp_path, *dev_path = NULL;
 528
 529         AA_BUG(!label);
 530         AA_BUG(!path);
 531
 532         if (type) {
 533                 struct file_system_type *fstype;
 534
 535                 fstype = get_fs_type(type);
 536                 if (!fstype)
 537                         return -ENODEV;
 538                 binary = fstype->fs_flags & FS_BINARY_MOUNTDATA;
 539                 requires_dev = fstype->fs_flags & FS_REQUIRES_DEV;
 540                 put_filesystem(fstype);
 541
 542                 if (requires_dev) {
 543                         if (!dev_name || !*dev_name)
 544                                 return -ENOENT;
 545
 546                         error = kern_path(dev_name, LOOKUP_FOLLOW, &tmp_path);
 547                         if (error)
 548                                 return error;
 549                         dev_path = &tmp_path;
 550                 }
 551         }
 552
 553         buffer = aa_get_buffer(false);
 554         if (!buffer) {
 555                 error = -ENOMEM;
 556                 goto out;
 557         }
 558         if (dev_path) {
 559                 dev_buffer = aa_get_buffer(false);
 560                 if (!dev_buffer) {
 561                         error = -ENOMEM;
 562                         goto out;
 563                 }
 564                 error = fn_for_each_confined(label, profile,
 565                         match_mnt(profile, path, buffer, dev_path, dev_buffer,
 566                                   type, flags, data, binary));
 567         } else {
 568                 error = fn_for_each_confined(label, profile,
 569                         match_mnt_path_str(profile, path, buffer, dev_name,
 570                                            type, flags, data, binary, NULL));
 571         }
 572
 573 out:
 574         aa_put_buffer(buffer);
 575         aa_put_buffer(dev_buffer);
 576         if (dev_path)
 577                 path_put(dev_path);
 578
 579         return error;
 580 }
 581
 582 static int profile_umount(struct aa_profile *profile, struct path *path,
 583                           char *buffer)
 584 {
 585         struct aa_perms perms = { };
 586         const char *name = NULL, *info = NULL;
 587         unsigned int state;
 588         int error;
 589
 590         AA_BUG(!profile);
 591         AA_BUG(!path);
 592
 593         if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 594                 return 0;
 595
 596         error = aa_path_name(path, path_flags(profile, path), buffer, &name,
 597                              &info, profile->disconnected);
 598         if (error)
 599                 goto audit;
 600
 601         state = aa_dfa_match(profile->policy.dfa,
 602                              profile->policy.start[AA_CLASS_MOUNT],
 603                              name);
 604         perms = compute_mnt_perms(profile->policy.dfa, state);
 605         if (AA_MAY_UMOUNT & ~perms.allow)
 606                 error = -EACCES;
 607
 608 audit:
 609         return audit_mount(profile, OP_UMOUNT, name, NULL, NULL, NULL, 0, NULL,
 610                            AA_MAY_UMOUNT, &perms, info, error);
 611 }
 612
 613 int aa_umount(struct aa_label *label, struct vfsmount *mnt, int flags)
 614 {
 615         struct aa_profile *profile;
 616         char *buffer = NULL;
 617         int error;
 618         struct path path = { .mnt = mnt, .dentry = mnt->mnt_root };
 619
 620         AA_BUG(!label);
 621         AA_BUG(!mnt);
 622
 623         buffer = aa_get_buffer(false);
 624         if (!buffer)
 625                 return -ENOMEM;
 626
 627         error = fn_for_each_confined(label, profile,
 628                         profile_umount(profile, &path, buffer));
 629         aa_put_buffer(buffer);
 630
 631         return error;
 632 }
 633
 634 /* helper fn for transition on pivotroot
 635  *
 636  * Returns: label for transition or ERR_PTR. Does not return NULL
 637  */
 638 static struct aa_label *build_pivotroot(struct aa_profile *profile,
 639                                         const struct path *new_path,
 640                                         char *new_buffer,
 641                                         const struct path *old_path,
 642                                         char *old_buffer)
 643 {
 644         const char *old_name, *new_name = NULL, *info = NULL;
 645         const char *trans_name = NULL;
 646         struct aa_perms perms = { };
 647         unsigned int state;
 648         int error;
 649
 650         AA_BUG(!profile);
 651         AA_BUG(!new_path);
 652         AA_BUG(!old_path);
 653
 654         if (profile_unconfined(profile) ||
 655             !PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 656                 return aa_get_newest_label(&profile->label);
 657
 658         error = aa_path_name(old_path, path_flags(profile, old_path),
 659                              old_buffer, &old_name, &info,
 660                              profile->disconnected);
 661         if (error)
 662                 goto audit;
 663         error = aa_path_name(new_path, path_flags(profile, new_path),
 664                              new_buffer, &new_name, &info,
 665                              profile->disconnected);
 666         if (error)
 667                 goto audit;
 668
 669         error = -EACCES;
 670         state = aa_dfa_match(profile->policy.dfa,
 671                              profile->policy.start[AA_CLASS_MOUNT],
 672                              new_name);
 673         state = aa_dfa_null_transition(profile->policy.dfa, state);
 674         state = aa_dfa_match(profile->policy.dfa, state, old_name);
 675         perms = compute_mnt_perms(profile->policy.dfa, state);
 676
 677         if (AA_MAY_PIVOTROOT & perms.allow)
 678                 error = 0;
 679
 680 audit:
 681         error = audit_mount(profile, OP_PIVOTROOT, new_name, old_name,
 682                             NULL, trans_name, 0, NULL, AA_MAY_PIVOTROOT,
 683                             &perms, info, error);
 684         if (error)
 685                 return ERR_PTR(error);
 686
 687         return aa_get_newest_label(&profile->label);
 688 }
 689
 690 int aa_pivotroot(struct aa_label *label, const struct path *old_path,
 691                  const struct path *new_path)
 692 {
 693         struct aa_profile *profile;
 694         struct aa_label *target = NULL;
 695         char *old_buffer = NULL, *new_buffer = NULL, *info = NULL;
 696         int error;
 697
 698         AA_BUG(!label);
 699         AA_BUG(!old_path);
 700         AA_BUG(!new_path);
 701
 702         old_buffer = aa_get_buffer(false);
 703         new_buffer = aa_get_buffer(false);
 704         error = -ENOMEM;
 705         if (!old_buffer || !new_buffer)
 706                 goto out;
 707         target = fn_label_build(label, profile, GFP_KERNEL,
 708                         build_pivotroot(profile, new_path, new_buffer,
 709                                         old_path, old_buffer));
 710         if (!target) {
 711                 info = "label build failed";
 712                 error = -ENOMEM;
 713                 goto fail;
 714         } else if (!IS_ERR(target)) {
 715                 error = aa_replace_current_label(target);
 716                 if (error) {
 717                         /* TODO: audit target */
 718                         aa_put_label(target);
 719                         goto out;
 720                 }
 721         } else
 722                 /* already audited error */
 723                 error = PTR_ERR(target);
 724 out:
 725         aa_put_buffer(old_buffer);
 726         aa_put_buffer(new_buffer);
 727
 728         return error;
 729
 730 fail:
 731         /* TODO: add back in auditing of new_name and old_name */
 732         error = fn_for_each(label, profile,
 733                         audit_mount(profile, OP_PIVOTROOT, NULL /*new_name */,
 734                                     NULL /* old_name */,
 735                                     NULL, NULL,
 736                                     0, NULL, AA_MAY_PIVOTROOT, &nullperms, info,
 737                                     error));
 738         goto out;
 739 }