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/crypto.h"
  28 #include "include/match.h"
  29 #include "include/policy.h"
  30 #include "include/policy_unpack.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 #define DFA_VALID_PERM_MASK             0xffffffff
 294 #define DFA_VALID_PERM2_MASK            0xffffffff
 295
 296 /**
 297  * verify_accept - verify the accept tables of a dfa
 298  * @dfa: dfa to verify accept tables of (NOT NULL)
 299  * @flags: flags governing dfa
 300  *
 301  * Returns: 1 if valid accept tables else 0 if error
 302  */
 303 static bool verify_accept(struct aa_dfa *dfa, int flags)
 304 {
 305         int i;
 306
 307         /* verify accept permissions */
 308         for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
 309                 int mode = ACCEPT_TABLE(dfa)[i];
 310
 311                 if (mode & ~DFA_VALID_PERM_MASK)
 312                         return 0;
 313
 314                 if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK)
 315                         return 0;
 316         }
 317         return 1;
 318 }
 319
 320 /**
 321  * unpack_dfa - unpack a file rule dfa
 322  * @e: serialized data extent information (NOT NULL)
 323  *
 324  * returns dfa or ERR_PTR or NULL if no dfa
 325  */
 326 static struct aa_dfa *unpack_dfa(struct aa_ext *e)
 327 {
 328         char *blob = NULL;
 329         size_t size;
 330         struct aa_dfa *dfa = NULL;
 331
 332         size = unpack_blob(e, &blob, "aadfa");
 333         if (size) {
 334                 /*
 335                  * The dfa is aligned with in the blob to 8 bytes
 336                  * from the beginning of the stream.
 337                  * alignment adjust needed by dfa unpack
 338                  */
 339                 size_t sz = blob - (char *) e->start -
 340                         ((e->pos - e->start) & 7);
 341                 size_t pad = ALIGN(sz, 8) - sz;
 342                 int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
 343                         TO_ACCEPT2_FLAG(YYTD_DATA32);
 344
 345
 346                 if (aa_g_paranoid_load)
 347                         flags |= DFA_FLAG_VERIFY_STATES;
 348
 349                 dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
 350
 351                 if (IS_ERR(dfa))
 352                         return dfa;
 353
 354                 if (!verify_accept(dfa, flags))
 355                         goto fail;
 356         }
 357
 358         return dfa;
 359
 360 fail:
 361         aa_put_dfa(dfa);
 362         return ERR_PTR(-EPROTO);
 363 }
 364
 365 /**
 366  * unpack_trans_table - unpack a profile transition table
 367  * @e: serialized data extent information  (NOT NULL)
 368  * @profile: profile to add the accept table to (NOT NULL)
 369  *
 370  * Returns: 1 if table successfully unpacked
 371  */
 372 static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
 373 {
 374         void *pos = e->pos;
 375
 376         /* exec table is optional */
 377         if (unpack_nameX(e, AA_STRUCT, "xtable")) {
 378                 int i, size;
 379
 380                 size = unpack_array(e, NULL);
 381                 /* currently 4 exec bits and entries 0-3 are reserved iupcx */
 382                 if (size > 16 - 4)
 383                         goto fail;
 384                 profile->file.trans.table = kzalloc(sizeof(char *) * size,
 385                                                     GFP_KERNEL);
 386                 if (!profile->file.trans.table)
 387                         goto fail;
 388
 389                 profile->file.trans.size = size;
 390                 for (i = 0; i < size; i++) {
 391                         char *str;
 392                         int c, j, size2 = unpack_strdup(e, &str, NULL);
 393                         /* unpack_strdup verifies that the last character is
 394                          * null termination byte.
 395                          */
 396                         if (!size2)
 397                                 goto fail;
 398                         profile->file.trans.table[i] = str;
 399                         /* verify that name doesn't start with space */
 400                         if (isspace(*str))
 401                                 goto fail;
 402
 403                         /* count internal #  of internal \0 */
 404                         for (c = j = 0; j < size2 - 2; j++) {
 405                                 if (!str[j])
 406                                         c++;
 407                         }
 408                         if (*str == ':') {
 409                                 /* beginning with : requires an embedded \0,
 410                                  * verify that exactly 1 internal \0 exists
 411                                  * trailing \0 already verified by unpack_strdup
 412                                  */
 413                                 if (c != 1)
 414                                         goto fail;
 415                                 /* first character after : must be valid */
 416                                 if (!str[1])
 417                                         goto fail;
 418                         } else if (c)
 419                                 /* fail - all other cases with embedded \0 */
 420                                 goto fail;
 421                 }
 422                 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
 423                         goto fail;
 424                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 425                         goto fail;
 426         }
 427         return 1;
 428
 429 fail:
 430         aa_free_domain_entries(&profile->file.trans);
 431         e->pos = pos;
 432         return 0;
 433 }
 434
 435 static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
 436 {
 437         void *pos = e->pos;
 438
 439         /* rlimits are optional */
 440         if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
 441                 int i, size;
 442                 u32 tmp = 0;
 443                 if (!unpack_u32(e, &tmp, NULL))
 444                         goto fail;
 445                 profile->rlimits.mask = tmp;
 446
 447                 size = unpack_array(e, NULL);
 448                 if (size > RLIM_NLIMITS)
 449                         goto fail;
 450                 for (i = 0; i < size; i++) {
 451                         u64 tmp2 = 0;
 452                         int a = aa_map_resource(i);
 453                         if (!unpack_u64(e, &tmp2, NULL))
 454                                 goto fail;
 455                         profile->rlimits.limits[a].rlim_max = tmp2;
 456                 }
 457                 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
 458                         goto fail;
 459                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 460                         goto fail;
 461         }
 462         return 1;
 463
 464 fail:
 465         e->pos = pos;
 466         return 0;
 467 }
 468
 469 /**
 470  * unpack_profile - unpack a serialized profile
 471  * @e: serialized data extent information (NOT NULL)
 472  *
 473  * NOTE: unpack profile sets audit struct if there is a failure
 474  */
 475 static struct aa_profile *unpack_profile(struct aa_ext *e)
 476 {
 477         struct aa_profile *profile = NULL;
 478         const char *name = NULL;
 479         int i, error = -EPROTO;
 480         kernel_cap_t tmpcap;
 481         u32 tmp;
 482
 483         /* check that we have the right struct being passed */
 484         if (!unpack_nameX(e, AA_STRUCT, "profile"))
 485                 goto fail;
 486         if (!unpack_str(e, &name, NULL))
 487                 goto fail;
 488
 489         profile = aa_alloc_profile(name);
 490         if (!profile)
 491                 return ERR_PTR(-ENOMEM);
 492
 493         /* profile renaming is optional */
 494         (void) unpack_str(e, &profile->rename, "rename");
 495
 496         /* attachment string is optional */
 497         (void) unpack_str(e, &profile->attach, "attach");
 498
 499         /* xmatch is optional and may be NULL */
 500         profile->xmatch = unpack_dfa(e);
 501         if (IS_ERR(profile->xmatch)) {
 502                 error = PTR_ERR(profile->xmatch);
 503                 profile->xmatch = NULL;
 504                 goto fail;
 505         }
 506         /* xmatch_len is not optional if xmatch is set */
 507         if (profile->xmatch) {
 508                 if (!unpack_u32(e, &tmp, NULL))
 509                         goto fail;
 510                 profile->xmatch_len = tmp;
 511         }
 512
 513         /* per profile debug flags (complain, audit) */
 514         if (!unpack_nameX(e, AA_STRUCT, "flags"))
 515                 goto fail;
 516         if (!unpack_u32(e, &tmp, NULL))
 517                 goto fail;
 518         if (tmp & PACKED_FLAG_HAT)
 519                 profile->flags |= PFLAG_HAT;
 520         if (!unpack_u32(e, &tmp, NULL))
 521                 goto fail;
 522         if (tmp == PACKED_MODE_COMPLAIN)
 523                 profile->mode = APPARMOR_COMPLAIN;
 524         else if (tmp == PACKED_MODE_KILL)
 525                 profile->mode = APPARMOR_KILL;
 526         else if (tmp == PACKED_MODE_UNCONFINED)
 527                 profile->mode = APPARMOR_UNCONFINED;
 528         if (!unpack_u32(e, &tmp, NULL))
 529                 goto fail;
 530         if (tmp)
 531                 profile->audit = AUDIT_ALL;
 532
 533         if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 534                 goto fail;
 535
 536         /* path_flags is optional */
 537         if (unpack_u32(e, &profile->path_flags, "path_flags"))
 538                 profile->path_flags |= profile->flags & PFLAG_MEDIATE_DELETED;
 539         else
 540                 /* set a default value if path_flags field is not present */
 541                 profile->path_flags = PFLAG_MEDIATE_DELETED;
 542
 543         if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
 544                 goto fail;
 545         if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
 546                 goto fail;
 547         if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
 548                 goto fail;
 549         if (!unpack_u32(e, &tmpcap.cap[0], NULL))
 550                 goto fail;
 551
 552         if (unpack_nameX(e, AA_STRUCT, "caps64")) {
 553                 /* optional upper half of 64 bit caps */
 554                 if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
 555                         goto fail;
 556                 if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
 557                         goto fail;
 558                 if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
 559                         goto fail;
 560                 if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
 561                         goto fail;
 562                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 563                         goto fail;
 564         }
 565
 566         if (unpack_nameX(e, AA_STRUCT, "capsx")) {
 567                 /* optional extended caps mediation mask */
 568                 if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
 569                         goto fail;
 570                 if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
 571                         goto fail;
 572                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 573                         goto fail;
 574         }
 575
 576         if (!unpack_rlimits(e, profile))
 577                 goto fail;
 578
 579         if (unpack_nameX(e, AA_STRUCT, "policydb")) {
 580                 /* generic policy dfa - optional and may be NULL */
 581                 profile->policy.dfa = unpack_dfa(e);
 582                 if (IS_ERR(profile->policy.dfa)) {
 583                         error = PTR_ERR(profile->policy.dfa);
 584                         profile->policy.dfa = NULL;
 585                         goto fail;
 586                 } else if (!profile->policy.dfa) {
 587                         error = -EPROTO;
 588                         goto fail;
 589                 }
 590                 if (!unpack_u32(e, &profile->policy.start[0], "start"))
 591                         /* default start state */
 592                         profile->policy.start[0] = DFA_START;
 593                 /* setup class index */
 594                 for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
 595                         profile->policy.start[i] =
 596                                 aa_dfa_next(profile->policy.dfa,
 597                                             profile->policy.start[0],
 598                                             i);
 599                 }
 600                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 601                         goto fail;
 602         }
 603
 604         /* get file rules */
 605         profile->file.dfa = unpack_dfa(e);
 606         if (IS_ERR(profile->file.dfa)) {
 607                 error = PTR_ERR(profile->file.dfa);
 608                 profile->file.dfa = NULL;
 609                 goto fail;
 610         }
 611
 612         if (!unpack_u32(e, &profile->file.start, "dfa_start"))
 613                 /* default start state */
 614                 profile->file.start = DFA_START;
 615
 616         if (!unpack_trans_table(e, profile))
 617                 goto fail;
 618
 619         if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 620                 goto fail;
 621
 622         return profile;
 623
 624 fail:
 625         if (profile)
 626                 name = NULL;
 627         else if (!name)
 628                 name = "unknown";
 629         audit_iface(profile, name, "failed to unpack profile", e, error);
 630         aa_free_profile(profile);
 631
 632         return ERR_PTR(error);
 633 }
 634
 635 /**
 636  * verify_head - unpack serialized stream header
 637  * @e: serialized data read head (NOT NULL)
 638  * @required: whether the header is required or optional
 639  * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
 640  *
 641  * Returns: error or 0 if header is good
 642  */
 643 static int verify_header(struct aa_ext *e, int required, const char **ns)
 644 {
 645         int error = -EPROTONOSUPPORT;
 646         const char *name = NULL;
 647         *ns = NULL;
 648
 649         /* get the interface version */
 650         if (!unpack_u32(e, &e->version, "version")) {
 651                 if (required) {
 652                         audit_iface(NULL, NULL, "invalid profile format", e,
 653                                     error);
 654                         return error;
 655                 }
 656
 657                 /* check that the interface version is currently supported */
 658                 if (e->version != 5) {
 659                         audit_iface(NULL, NULL, "unsupported interface version",
 660                                     e, error);
 661                         return error;
 662                 }
 663         }
 664
 665
 666         /* read the namespace if present */
 667         if (unpack_str(e, &name, "namespace")) {
 668                 if (*ns && strcmp(*ns, name))
 669                         audit_iface(NULL, NULL, "invalid ns change", e, error);
 670                 else if (!*ns)
 671                         *ns = name;
 672         }
 673
 674         return 0;
 675 }
 676
 677 static bool verify_xindex(int xindex, int table_size)
 678 {
 679         int index, xtype;
 680         xtype = xindex & AA_X_TYPE_MASK;
 681         index = xindex & AA_X_INDEX_MASK;
 682         if (xtype == AA_X_TABLE && index >= table_size)
 683                 return 0;
 684         return 1;
 685 }
 686
 687 /* verify dfa xindexes are in range of transition tables */
 688 static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
 689 {
 690         int i;
 691         for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
 692                 if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
 693                         return 0;
 694                 if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
 695                         return 0;
 696         }
 697         return 1;
 698 }
 699
 700 /**
 701  * verify_profile - Do post unpack analysis to verify profile consistency
 702  * @profile: profile to verify (NOT NULL)
 703  *
 704  * Returns: 0 if passes verification else error
 705  */
 706 static int verify_profile(struct aa_profile *profile)
 707 {
 708         if (aa_g_paranoid_load) {
 709                 if (profile->file.dfa &&
 710                     !verify_dfa_xindex(profile->file.dfa,
 711                                        profile->file.trans.size)) {
 712                         audit_iface(profile, NULL, "Invalid named transition",
 713                                     NULL, -EPROTO);
 714                         return -EPROTO;
 715                 }
 716         }
 717
 718         return 0;
 719 }
 720
 721 void aa_load_ent_free(struct aa_load_ent *ent)
 722 {
 723         if (ent) {
 724                 aa_put_profile(ent->rename);
 725                 aa_put_profile(ent->old);
 726                 aa_put_profile(ent->new);
 727                 kzfree(ent);
 728         }
 729 }
 730
 731 struct aa_load_ent *aa_load_ent_alloc(void)
 732 {
 733         struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
 734         if (ent)
 735                 INIT_LIST_HEAD(&ent->list);
 736         return ent;
 737 }
 738
 739 /**
 740  * aa_unpack - unpack packed binary profile(s) data loaded from user space
 741  * @udata: user data copied to kmem  (NOT NULL)
 742  * @size: the size of the user data
 743  * @lh: list to place unpacked profiles in a aa_repl_ws
 744  * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
 745  *
 746  * Unpack user data and return refcounted allocated profile(s) stored in
 747  * @lh in order of discovery, with the list chain stored in base.list
 748  * or error
 749  *
 750  * Returns: profile(s) on @lh else error pointer if fails to unpack
 751  */
 752 int aa_unpack(void *udata, size_t size, struct list_head *lh, const char **ns)
 753 {
 754         struct aa_load_ent *tmp, *ent;
 755         struct aa_profile *profile = NULL;
 756         int error;
 757         struct aa_ext e = {
 758                 .start = udata,
 759                 .end = udata + size,
 760                 .pos = udata,
 761         };
 762
 763         *ns = NULL;
 764         while (e.pos < e.end) {
 765                 void *start;
 766                 error = verify_header(&e, e.pos == e.start, ns);
 767                 if (error)
 768                         goto fail;
 769
 770                 start = e.pos;
 771                 profile = unpack_profile(&e);
 772                 if (IS_ERR(profile)) {
 773                         error = PTR_ERR(profile);
 774                         goto fail;
 775                 }
 776
 777                 error = verify_profile(profile);
 778                 if (error)
 779                         goto fail_profile;
 780
 781                 error = aa_calc_profile_hash(profile, e.version, start,
 782                                                      e.pos - start);
 783                 if (error)
 784                         goto fail_profile;
 785
 786                 ent = aa_load_ent_alloc();
 787                 if (!ent) {
 788                         error = -ENOMEM;
 789                         goto fail_profile;
 790                 }
 791
 792                 ent->new = profile;
 793                 list_add_tail(&ent->list, lh);
 794         }
 795
 796         return 0;
 797
 798 fail_profile:
 799         aa_put_profile(profile);
 800
 801 fail:
 802         list_for_each_entry_safe(ent, tmp, lh, list) {
 803                 list_del_init(&ent->list);
 804                 aa_load_ent_free(ent);
 805         }
 806
 807         return error;
 808 }