security/apparmor/policy_unpack.c

   1 /*
   2  * AppArmor security module
   3  *
   4  * This file contains AppArmor functions for unpacking policy loaded from
   5  * userspace.
   6  *
   7  * Copyright (C) 1998-2008 Novell/SUSE
   8  * Copyright 2009-2010 Canonical Ltd.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation, version 2 of the
  13  * License.
  14  *
  15  * AppArmor uses a serialized binary format for loading policy. To find
  16  * policy format documentation look in Documentation/security/apparmor.txt
  17  * All policy is validated before it is used.
  18  */
  19
  20 #include <asm/unaligned.h>
  21 #include <linux/ctype.h>
  22 #include <linux/errno.h>
  23
  24 #include "include/apparmor.h"
  25 #include "include/audit.h"
  26 #include "include/context.h"
  27 #include "include/match.h"
  28 #include "include/policy.h"
  29 #include "include/policy_unpack.h"
  30 #include "include/sid.h"
  31
  32 /*
  33  * The AppArmor interface treats data as a type byte followed by the
  34  * actual data.  The interface has the notion of a a named entry
  35  * which has a name (AA_NAME typecode followed by name string) followed by
  36  * the entries typecode and data.  Named types allow for optional
  37  * elements and extensions to be added and tested for without breaking
  38  * backwards compatibility.
  39  */
  40
  41 enum aa_code {
  42         AA_U8,
  43         AA_U16,
  44         AA_U32,
  45         AA_U64,
  46         AA_NAME,                /* same as string except it is items name */
  47         AA_STRING,
  48         AA_BLOB,
  49         AA_STRUCT,
  50         AA_STRUCTEND,
  51         AA_LIST,
  52         AA_LISTEND,
  53         AA_ARRAY,
  54         AA_ARRAYEND,
  55 };
  56
  57 /*
  58  * aa_ext is the read of the buffer containing the serialized profile.  The
  59  * data is copied into a kernel buffer in apparmorfs and then handed off to
  60  * the unpack routines.
  61  */
  62 struct aa_ext {
  63         void *start;
  64         void *end;
  65         void *pos;              /* pointer to current position in the buffer */
  66         u32 version;
  67 };
  68
  69 /* audit callback for unpack fields */
  70 static void audit_cb(struct audit_buffer *ab, void *va)
  71 {
  72         struct common_audit_data *sa = va;
  73         if (sa->aad->iface.target) {
  74                 struct aa_profile *name = sa->aad->iface.target;
  75                 audit_log_format(ab, " name=");
  76                 audit_log_untrustedstring(ab, name->base.hname);
  77         }
  78         if (sa->aad->iface.pos)
  79                 audit_log_format(ab, " offset=%ld", sa->aad->iface.pos);
  80 }
  81
  82 /**
  83  * audit_iface - do audit message for policy unpacking/load/replace/remove
  84  * @new: profile if it has been allocated (MAYBE NULL)
  85  * @name: name of the profile being manipulated (MAYBE NULL)
  86  * @info: any extra info about the failure (MAYBE NULL)
  87  * @e: buffer position info
  88  * @error: error code
  89  *
  90  * Returns: %0 or error
  91  */
  92 static int audit_iface(struct aa_profile *new, const char *name,
  93                        const char *info, struct aa_ext *e, int error)
  94 {
  95         struct aa_profile *profile = __aa_current_profile();
  96         struct common_audit_data sa;
  97         struct apparmor_audit_data aad = {0,};
  98         sa.type = LSM_AUDIT_DATA_NONE;
  99         sa.aad = &aad;
 100         if (e)
 101                 aad.iface.pos = e->pos - e->start;
 102         aad.iface.target = new;
 103         aad.name = name;
 104         aad.info = info;
 105         aad.error = error;
 106
 107         return aa_audit(AUDIT_APPARMOR_STATUS, profile, GFP_KERNEL, &sa,
 108                         audit_cb);
 109 }
 110
 111 /* test if read will be in packed data bounds */
 112 static bool inbounds(struct aa_ext *e, size_t size)
 113 {
 114         return (size <= e->end - e->pos);
 115 }
 116
 117 /**
 118  * aa_u16_chunck - test and do bounds checking for a u16 size based chunk
 119  * @e: serialized data read head (NOT NULL)
 120  * @chunk: start address for chunk of data (NOT NULL)
 121  *
 122  * Returns: the size of chunk found with the read head at the end of the chunk.
 123  */
 124 static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
 125 {
 126         size_t size = 0;
 127
 128         if (!inbounds(e, sizeof(u16)))
 129                 return 0;
 130         size = le16_to_cpu(get_unaligned((u16 *) e->pos));
 131         e->pos += sizeof(u16);
 132         if (!inbounds(e, size))
 133                 return 0;
 134         *chunk = e->pos;
 135         e->pos += size;
 136         return size;
 137 }
 138
 139 /* unpack control byte */
 140 static bool unpack_X(struct aa_ext *e, enum aa_code code)
 141 {
 142         if (!inbounds(e, 1))
 143                 return 0;
 144         if (*(u8 *) e->pos != code)
 145                 return 0;
 146         e->pos++;
 147         return 1;
 148 }
 149
 150 /**
 151  * unpack_nameX - check is the next element is of type X with a name of @name
 152  * @e: serialized data extent information  (NOT NULL)
 153  * @code: type code
 154  * @name: name to match to the serialized element.  (MAYBE NULL)
 155  *
 156  * check that the next serialized data element is of type X and has a tag
 157  * name @name.  If @name is specified then there must be a matching
 158  * name element in the stream.  If @name is NULL any name element will be
 159  * skipped and only the typecode will be tested.
 160  *
 161  * Returns 1 on success (both type code and name tests match) and the read
 162  * head is advanced past the headers
 163  *
 164  * Returns: 0 if either match fails, the read head does not move
 165  */
 166 static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
 167 {
 168         /*
 169          * May need to reset pos if name or type doesn't match
 170          */
 171         void *pos = e->pos;
 172         /*
 173          * Check for presence of a tagname, and if present name size
 174          * AA_NAME tag value is a u16.
 175          */
 176         if (unpack_X(e, AA_NAME)) {
 177                 char *tag = NULL;
 178                 size_t size = unpack_u16_chunk(e, &tag);
 179                 /* if a name is specified it must match. otherwise skip tag */
 180                 if (name && (!size || strcmp(name, tag)))
 181                         goto fail;
 182         } else if (name) {
 183                 /* if a name is specified and there is no name tag fail */
 184                 goto fail;
 185         }
 186
 187         /* now check if type code matches */
 188         if (unpack_X(e, code))
 189                 return 1;
 190
 191 fail:
 192         e->pos = pos;
 193         return 0;
 194 }
 195
 196 static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
 197 {
 198         if (unpack_nameX(e, AA_U32, name)) {
 199                 if (!inbounds(e, sizeof(u32)))
 200                         return 0;
 201                 if (data)
 202                         *data = le32_to_cpu(get_unaligned((u32 *) e->pos));
 203                 e->pos += sizeof(u32);
 204                 return 1;
 205         }
 206         return 0;
 207 }
 208
 209 static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
 210 {
 211         if (unpack_nameX(e, AA_U64, name)) {
 212                 if (!inbounds(e, sizeof(u64)))
 213                         return 0;
 214                 if (data)
 215                         *data = le64_to_cpu(get_unaligned((u64 *) e->pos));
 216                 e->pos += sizeof(u64);
 217                 return 1;
 218         }
 219         return 0;
 220 }
 221
 222 static size_t unpack_array(struct aa_ext *e, const char *name)
 223 {
 224         if (unpack_nameX(e, AA_ARRAY, name)) {
 225                 int size;
 226                 if (!inbounds(e, sizeof(u16)))
 227                         return 0;
 228                 size = (int)le16_to_cpu(get_unaligned((u16 *) e->pos));
 229                 e->pos += sizeof(u16);
 230                 return size;
 231         }
 232         return 0;
 233 }
 234
 235 static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
 236 {
 237         if (unpack_nameX(e, AA_BLOB, name)) {
 238                 u32 size;
 239                 if (!inbounds(e, sizeof(u32)))
 240                         return 0;
 241                 size = le32_to_cpu(get_unaligned((u32 *) e->pos));
 242                 e->pos += sizeof(u32);
 243                 if (inbounds(e, (size_t) size)) {
 244                         *blob = e->pos;
 245                         e->pos += size;
 246                         return size;
 247                 }
 248         }
 249         return 0;
 250 }
 251
 252 static int unpack_str(struct aa_ext *e, const char **string, const char *name)
 253 {
 254         char *src_str;
 255         size_t size = 0;
 256         void *pos = e->pos;
 257         *string = NULL;
 258         if (unpack_nameX(e, AA_STRING, name)) {
 259                 size = unpack_u16_chunk(e, &src_str);
 260                 if (size) {
 261                         /* strings are null terminated, length is size - 1 */
 262                         if (src_str[size - 1] != 0)
 263                                 goto fail;
 264                         *string = src_str;
 265                 }
 266         }
 267         return size;
 268
 269 fail:
 270         e->pos = pos;
 271         return 0;
 272 }
 273
 274 static int unpack_strdup(struct aa_ext *e, char **string, const char *name)
 275 {
 276         const char *tmp;
 277         void *pos = e->pos;
 278         int res = unpack_str(e, &tmp, name);
 279         *string = NULL;
 280
 281         if (!res)
 282                 return 0;
 283
 284         *string = kmemdup(tmp, res, GFP_KERNEL);
 285         if (!*string) {
 286                 e->pos = pos;
 287                 return 0;
 288         }
 289
 290         return res;
 291 }
 292
 293 /**
 294  * verify_accept - verify the accept tables of a dfa
 295  * @dfa: dfa to verify accept tables of (NOT NULL)
 296  * @flags: flags governing dfa
 297  *
 298  * Returns: 1 if valid accept tables else 0 if error
 299  */
 300 static bool verify_accept(struct aa_dfa *dfa, int flags)
 301 {
 302         int i;
 303
 304         /* verify accept permissions */
 305         for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
 306                 int mode = ACCEPT_TABLE(dfa)[i];
 307
 308                 if (mode & ~DFA_VALID_PERM_MASK)
 309                         return 0;
 310
 311                 if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK)
 312                         return 0;
 313         }
 314         return 1;
 315 }
 316
 317 /**
 318  * unpack_dfa - unpack a file rule dfa
 319  * @e: serialized data extent information (NOT NULL)
 320  *
 321  * returns dfa or ERR_PTR or NULL if no dfa
 322  */
 323 static struct aa_dfa *unpack_dfa(struct aa_ext *e)
 324 {
 325         char *blob = NULL;
 326         size_t size;
 327         struct aa_dfa *dfa = NULL;
 328
 329         size = unpack_blob(e, &blob, "aadfa");
 330         if (size) {
 331                 /*
 332                  * The dfa is aligned with in the blob to 8 bytes
 333                  * from the beginning of the stream.
 334                  */
 335                 size_t sz = blob - (char *)e->start;
 336                 size_t pad = ALIGN(sz, 8) - sz;
 337                 int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
 338                         TO_ACCEPT2_FLAG(YYTD_DATA32);
 339
 340
 341                 if (aa_g_paranoid_load)
 342                         flags |= DFA_FLAG_VERIFY_STATES;
 343
 344                 dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
 345
 346                 if (IS_ERR(dfa))
 347                         return dfa;
 348
 349                 if (!verify_accept(dfa, flags))
 350                         goto fail;
 351         }
 352
 353         return dfa;
 354
 355 fail:
 356         aa_put_dfa(dfa);
 357         return ERR_PTR(-EPROTO);
 358 }
 359
 360 /**
 361  * unpack_trans_table - unpack a profile transition table
 362  * @e: serialized data extent information  (NOT NULL)
 363  * @profile: profile to add the accept table to (NOT NULL)
 364  *
 365  * Returns: 1 if table successfully unpacked
 366  */
 367 static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
 368 {
 369         void *pos = e->pos;
 370
 371         /* exec table is optional */
 372         if (unpack_nameX(e, AA_STRUCT, "xtable")) {
 373                 int i, size;
 374
 375                 size = unpack_array(e, NULL);
 376                 /* currently 4 exec bits and entries 0-3 are reserved iupcx */
 377                 if (size > 16 - 4)
 378                         goto fail;
 379                 profile->file.trans.table = kzalloc(sizeof(char *) * size,
 380                                                     GFP_KERNEL);
 381                 if (!profile->file.trans.table)
 382                         goto fail;
 383
 384                 profile->file.trans.size = size;
 385                 for (i = 0; i < size; i++) {
 386                         char *str;
 387                         int c, j, size2 = unpack_strdup(e, &str, NULL);
 388                         /* unpack_strdup verifies that the last character is
 389                          * null termination byte.
 390                          */
 391                         if (!size2)
 392                                 goto fail;
 393                         profile->file.trans.table[i] = str;
 394                         /* verify that name doesn't start with space */
 395                         if (isspace(*str))
 396                                 goto fail;
 397
 398                         /* count internal #  of internal \0 */
 399                         for (c = j = 0; j < size2 - 2; j++) {
 400                                 if (!str[j])
 401                                         c++;
 402                         }
 403                         if (*str == ':') {
 404                                 /* beginning with : requires an embedded \0,
 405                                  * verify that exactly 1 internal \0 exists
 406                                  * trailing \0 already verified by unpack_strdup
 407                                  */
 408                                 if (c != 1)
 409                                         goto fail;
 410                                 /* first character after : must be valid */
 411                                 if (!str[1])
 412                                         goto fail;
 413                         } else if (c)
 414                                 /* fail - all other cases with embedded \0 */
 415                                 goto fail;
 416                 }
 417                 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
 418                         goto fail;
 419                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 420                         goto fail;
 421         }
 422         return 1;
 423
 424 fail:
 425         aa_free_domain_entries(&profile->file.trans);
 426         e->pos = pos;
 427         return 0;
 428 }
 429
 430 static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
 431 {
 432         void *pos = e->pos;
 433
 434         /* rlimits are optional */
 435         if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
 436                 int i, size;
 437                 u32 tmp = 0;
 438                 if (!unpack_u32(e, &tmp, NULL))
 439                         goto fail;
 440                 profile->rlimits.mask = tmp;
 441
 442                 size = unpack_array(e, NULL);
 443                 if (size > RLIM_NLIMITS)
 444                         goto fail;
 445                 for (i = 0; i < size; i++) {
 446                         u64 tmp2 = 0;
 447                         int a = aa_map_resource(i);
 448                         if (!unpack_u64(e, &tmp2, NULL))
 449                                 goto fail;
 450                         profile->rlimits.limits[a].rlim_max = tmp2;
 451                 }
 452                 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
 453                         goto fail;
 454                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 455                         goto fail;
 456         }
 457         return 1;
 458
 459 fail:
 460         e->pos = pos;
 461         return 0;
 462 }
 463
 464 /**
 465  * unpack_profile - unpack a serialized profile
 466  * @e: serialized data extent information (NOT NULL)
 467  *
 468  * NOTE: unpack profile sets audit struct if there is a failure
 469  */
 470 static struct aa_profile *unpack_profile(struct aa_ext *e)
 471 {
 472         struct aa_profile *profile = NULL;
 473         const char *name = NULL;
 474         int i, error = -EPROTO;
 475         kernel_cap_t tmpcap;
 476         u32 tmp;
 477
 478         /* check that we have the right struct being passed */
 479         if (!unpack_nameX(e, AA_STRUCT, "profile"))
 480                 goto fail;
 481         if (!unpack_str(e, &name, NULL))
 482                 goto fail;
 483
 484         profile = aa_alloc_profile(name);
 485         if (!profile)
 486                 return ERR_PTR(-ENOMEM);
 487
 488         /* profile renaming is optional */
 489         (void) unpack_str(e, &profile->rename, "rename");
 490
 491         /* xmatch is optional and may be NULL */
 492         profile->xmatch = unpack_dfa(e);
 493         if (IS_ERR(profile->xmatch)) {
 494                 error = PTR_ERR(profile->xmatch);
 495                 profile->xmatch = NULL;
 496                 goto fail;
 497         }
 498         /* xmatch_len is not optional if xmatch is set */
 499         if (profile->xmatch) {
 500                 if (!unpack_u32(e, &tmp, NULL))
 501                         goto fail;
 502                 profile->xmatch_len = tmp;
 503         }
 504
 505         /* per profile debug flags (complain, audit) */
 506         if (!unpack_nameX(e, AA_STRUCT, "flags"))
 507                 goto fail;
 508         if (!unpack_u32(e, &tmp, NULL))
 509                 goto fail;
 510         if (tmp)
 511                 profile->flags |= PFLAG_HAT;
 512         if (!unpack_u32(e, &tmp, NULL))
 513                 goto fail;
 514         if (tmp)
 515                 profile->mode = APPARMOR_COMPLAIN;
 516         if (!unpack_u32(e, &tmp, NULL))
 517                 goto fail;
 518         if (tmp)
 519                 profile->audit = AUDIT_ALL;
 520
 521         if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 522                 goto fail;
 523
 524         /* path_flags is optional */
 525         if (unpack_u32(e, &profile->path_flags, "path_flags"))
 526                 profile->path_flags |= profile->flags & PFLAG_MEDIATE_DELETED;
 527         else
 528                 /* set a default value if path_flags field is not present */
 529                 profile->path_flags = PFLAG_MEDIATE_DELETED;
 530
 531         if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
 532                 goto fail;
 533         if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
 534                 goto fail;
 535         if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
 536                 goto fail;
 537         if (!unpack_u32(e, &tmpcap.cap[0], NULL))
 538                 goto fail;
 539
 540         if (unpack_nameX(e, AA_STRUCT, "caps64")) {
 541                 /* optional upper half of 64 bit caps */
 542                 if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
 543                         goto fail;
 544                 if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
 545                         goto fail;
 546                 if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
 547                         goto fail;
 548                 if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
 549                         goto fail;
 550                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 551                         goto fail;
 552         }
 553
 554         if (unpack_nameX(e, AA_STRUCT, "capsx")) {
 555                 /* optional extended caps mediation mask */
 556                 if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
 557                         goto fail;
 558                 if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
 559                         goto fail;
 560                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 561                         goto fail;
 562         }
 563
 564         if (!unpack_rlimits(e, profile))
 565                 goto fail;
 566
 567         if (unpack_nameX(e, AA_STRUCT, "policydb")) {
 568                 /* generic policy dfa - optional and may be NULL */
 569                 profile->policy.dfa = unpack_dfa(e);
 570                 if (IS_ERR(profile->policy.dfa)) {
 571                         error = PTR_ERR(profile->policy.dfa);
 572                         profile->policy.dfa = NULL;
 573                         goto fail;
 574                 }
 575                 if (!unpack_u32(e, &profile->policy.start[0], "start"))
 576                         /* default start state */
 577                         profile->policy.start[0] = DFA_START;
 578                 /* setup class index */
 579                 for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
 580                         profile->policy.start[i] =
 581                                 aa_dfa_next(profile->policy.dfa,
 582                                             profile->policy.start[0],
 583                                             i);
 584                 }
 585                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 586                         goto fail;
 587         }
 588
 589         /* get file rules */
 590         profile->file.dfa = unpack_dfa(e);
 591         if (IS_ERR(profile->file.dfa)) {
 592                 error = PTR_ERR(profile->file.dfa);
 593                 profile->file.dfa = NULL;
 594                 goto fail;
 595         }
 596
 597         if (!unpack_u32(e, &profile->file.start, "dfa_start"))
 598                 /* default start state */
 599                 profile->file.start = DFA_START;
 600
 601         if (!unpack_trans_table(e, profile))
 602                 goto fail;
 603
 604         if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 605                 goto fail;
 606
 607         return profile;
 608
 609 fail:
 610         if (profile)
 611                 name = NULL;
 612         else if (!name)
 613                 name = "unknown";
 614         audit_iface(profile, name, "failed to unpack profile", e, error);
 615         aa_put_profile(profile);
 616
 617         return ERR_PTR(error);
 618 }
 619
 620 /**
 621  * verify_head - unpack serialized stream header
 622  * @e: serialized data read head (NOT NULL)
 623  * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
 624  *
 625  * Returns: error or 0 if header is good
 626  */
 627 static int verify_header(struct aa_ext *e, const char **ns)
 628 {
 629         int error = -EPROTONOSUPPORT;
 630         /* get the interface version */
 631         if (!unpack_u32(e, &e->version, "version")) {
 632                 audit_iface(NULL, NULL, "invalid profile format", e, error);
 633                 return error;
 634         }
 635
 636         /* check that the interface version is currently supported */
 637         if (e->version != 5) {
 638                 audit_iface(NULL, NULL, "unsupported interface version", e,
 639                             error);
 640                 return error;
 641         }
 642
 643         /* read the namespace if present */
 644         if (!unpack_str(e, ns, "namespace"))
 645                 *ns = NULL;
 646
 647         return 0;
 648 }
 649
 650 static bool verify_xindex(int xindex, int table_size)
 651 {
 652         int index, xtype;
 653         xtype = xindex & AA_X_TYPE_MASK;
 654         index = xindex & AA_X_INDEX_MASK;
 655         if (xtype == AA_X_TABLE && index > table_size)
 656                 return 0;
 657         return 1;
 658 }
 659
 660 /* verify dfa xindexes are in range of transition tables */
 661 static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
 662 {
 663         int i;
 664         for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
 665                 if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
 666                         return 0;
 667                 if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
 668                         return 0;
 669         }
 670         return 1;
 671 }
 672
 673 /**
 674  * verify_profile - Do post unpack analysis to verify profile consistency
 675  * @profile: profile to verify (NOT NULL)
 676  *
 677  * Returns: 0 if passes verification else error
 678  */
 679 static int verify_profile(struct aa_profile *profile)
 680 {
 681         if (aa_g_paranoid_load) {
 682                 if (profile->file.dfa &&
 683                     !verify_dfa_xindex(profile->file.dfa,
 684                                        profile->file.trans.size)) {
 685                         audit_iface(profile, NULL, "Invalid named transition",
 686                                     NULL, -EPROTO);
 687                         return -EPROTO;
 688                 }
 689         }
 690
 691         return 0;
 692 }
 693
 694 /**
 695  * aa_unpack - unpack packed binary profile data loaded from user space
 696  * @udata: user data copied to kmem  (NOT NULL)
 697  * @size: the size of the user data
 698  * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
 699  *
 700  * Unpack user data and return refcounted allocated profile or ERR_PTR
 701  *
 702  * Returns: profile else error pointer if fails to unpack
 703  */
 704 struct aa_profile *aa_unpack(void *udata, size_t size, const char **ns)
 705 {
 706         struct aa_profile *profile = NULL;
 707         int error;
 708         struct aa_ext e = {
 709                 .start = udata,
 710                 .end = udata + size,
 711                 .pos = udata,
 712         };
 713
 714         error = verify_header(&e, ns);
 715         if (error)
 716                 return ERR_PTR(error);
 717
 718         profile = unpack_profile(&e);
 719         if (IS_ERR(profile))
 720                 return profile;
 721
 722         error = verify_profile(profile);
 723         if (error) {
 724                 aa_put_profile(profile);
 725                 profile = ERR_PTR(error);
 726         }
 727
 728         /* return refcount */
 729         return profile;
 730 }