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 #include <linux/string.h>
  24
  25 #include "include/apparmor.h"
  26 #include "include/audit.h"
  27 #include "include/context.h"
  28 #include "include/crypto.h"
  29 #include "include/match.h"
  30 #include "include/path.h"
  31 #include "include/policy.h"
  32 #include "include/policy_unpack.h"
  33
  34 #define K_ABI_MASK 0x3ff
  35 #define FORCE_COMPLAIN_FLAG 0x800
  36 #define VERSION_CMP(OP, X, Y) (((X) & K_ABI_MASK) OP ((Y) & K_ABI_MASK))
  37
  38 #define v5      5       /* base version */
  39 #define v6      6       /* per entry policydb mediation check */
  40 #define v7      7       /* full network masking */
  41
  42 /*
  43  * The AppArmor interface treats data as a type byte followed by the
  44  * actual data.  The interface has the notion of a a named entry
  45  * which has a name (AA_NAME typecode followed by name string) followed by
  46  * the entries typecode and data.  Named types allow for optional
  47  * elements and extensions to be added and tested for without breaking
  48  * backwards compatibility.
  49  */
  50
  51 enum aa_code {
  52         AA_U8,
  53         AA_U16,
  54         AA_U32,
  55         AA_U64,
  56         AA_NAME,                /* same as string except it is items name */
  57         AA_STRING,
  58         AA_BLOB,
  59         AA_STRUCT,
  60         AA_STRUCTEND,
  61         AA_LIST,
  62         AA_LISTEND,
  63         AA_ARRAY,
  64         AA_ARRAYEND,
  65 };
  66
  67 /*
  68  * aa_ext is the read of the buffer containing the serialized profile.  The
  69  * data is copied into a kernel buffer in apparmorfs and then handed off to
  70  * the unpack routines.
  71  */
  72 struct aa_ext {
  73         void *start;
  74         void *end;
  75         void *pos;              /* pointer to current position in the buffer */
  76         u32 version;
  77 };
  78
  79 /* audit callback for unpack fields */
  80 static void audit_cb(struct audit_buffer *ab, void *va)
  81 {
  82         struct common_audit_data *sa = va;
  83
  84         if (aad(sa)->iface.ns) {
  85                 audit_log_format(ab, " ns=");
  86                 audit_log_untrustedstring(ab, aad(sa)->iface.ns);
  87         }
  88         if (aad(sa)->name) {
  89                 audit_log_format(ab, " name=");
  90                 audit_log_untrustedstring(ab, aad(sa)->name);
  91         }
  92         if (aad(sa)->iface.pos)
  93                 audit_log_format(ab, " offset=%ld", aad(sa)->iface.pos);
  94 }
  95
  96 /**
  97  * audit_iface - do audit message for policy unpacking/load/replace/remove
  98  * @new: profile if it has been allocated (MAYBE NULL)
  99  * @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL)
 100  * @name: name of the profile being manipulated (MAYBE NULL)
 101  * @info: any extra info about the failure (MAYBE NULL)
 102  * @e: buffer position info
 103  * @error: error code
 104  *
 105  * Returns: %0 or error
 106  */
 107 static int audit_iface(struct aa_profile *new, const char *ns_name,
 108                        const char *name, const char *info, struct aa_ext *e,
 109                        int error)
 110 {
 111         struct aa_profile *profile = labels_profile(aa_current_raw_label());
 112         DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL);
 113         if (e)
 114                 aad(&sa)->iface.pos = e->pos - e->start;
 115
 116         aad(&sa)->iface.ns = ns_name;
 117         if (new)
 118                 aad(&sa)->name = new->base.hname;
 119         else
 120                 aad(&sa)->name = name;
 121         aad(&sa)->info = info;
 122         aad(&sa)->error = error;
 123
 124         return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb);
 125 }
 126
 127 /* test if read will be in packed data bounds */
 128 static bool inbounds(struct aa_ext *e, size_t size)
 129 {
 130         return (size <= e->end - e->pos);
 131 }
 132
 133 /**
 134  * aa_u16_chunck - test and do bounds checking for a u16 size based chunk
 135  * @e: serialized data read head (NOT NULL)
 136  * @chunk: start address for chunk of data (NOT NULL)
 137  *
 138  * Returns: the size of chunk found with the read head at the end of the chunk.
 139  */
 140 static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
 141 {
 142         size_t size = 0;
 143
 144         if (!inbounds(e, sizeof(u16)))
 145                 return 0;
 146         size = le16_to_cpu(get_unaligned((u16 *) e->pos));
 147         e->pos += sizeof(u16);
 148         if (!inbounds(e, size))
 149                 return 0;
 150         *chunk = e->pos;
 151         e->pos += size;
 152         return size;
 153 }
 154
 155 /* unpack control byte */
 156 static bool unpack_X(struct aa_ext *e, enum aa_code code)
 157 {
 158         if (!inbounds(e, 1))
 159                 return 0;
 160         if (*(u8 *) e->pos != code)
 161                 return 0;
 162         e->pos++;
 163         return 1;
 164 }
 165
 166 /**
 167  * unpack_nameX - check is the next element is of type X with a name of @name
 168  * @e: serialized data extent information  (NOT NULL)
 169  * @code: type code
 170  * @name: name to match to the serialized element.  (MAYBE NULL)
 171  *
 172  * check that the next serialized data element is of type X and has a tag
 173  * name @name.  If @name is specified then there must be a matching
 174  * name element in the stream.  If @name is NULL any name element will be
 175  * skipped and only the typecode will be tested.
 176  *
 177  * Returns 1 on success (both type code and name tests match) and the read
 178  * head is advanced past the headers
 179  *
 180  * Returns: 0 if either match fails, the read head does not move
 181  */
 182 static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
 183 {
 184         /*
 185          * May need to reset pos if name or type doesn't match
 186          */
 187         void *pos = e->pos;
 188         /*
 189          * Check for presence of a tagname, and if present name size
 190          * AA_NAME tag value is a u16.
 191          */
 192         if (unpack_X(e, AA_NAME)) {
 193                 char *tag = NULL;
 194                 size_t size = unpack_u16_chunk(e, &tag);
 195                 /* if a name is specified it must match. otherwise skip tag */
 196                 if (name && (!size || strcmp(name, tag)))
 197                         goto fail;
 198         } else if (name) {
 199                 /* if a name is specified and there is no name tag fail */
 200                 goto fail;
 201         }
 202
 203         /* now check if type code matches */
 204         if (unpack_X(e, code))
 205                 return 1;
 206
 207 fail:
 208         e->pos = pos;
 209         return 0;
 210 }
 211
 212 static bool unpack_u16(struct aa_ext *e, u16 *data, const char *name)
 213 {
 214         if (unpack_nameX(e, AA_U16, name)) {
 215                 if (!inbounds(e, sizeof(u16)))
 216                         return 0;
 217                 if (data)
 218                         *data = le16_to_cpu(get_unaligned((u16 *) e->pos));
 219                 e->pos += sizeof(u16);
 220                 return 1;
 221         }
 222         return 0;
 223 }
 224
 225 static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
 226 {
 227         if (unpack_nameX(e, AA_U32, name)) {
 228                 if (!inbounds(e, sizeof(u32)))
 229                         return 0;
 230                 if (data)
 231                         *data = le32_to_cpu(get_unaligned((u32 *) e->pos));
 232                 e->pos += sizeof(u32);
 233                 return 1;
 234         }
 235         return 0;
 236 }
 237
 238 static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
 239 {
 240         if (unpack_nameX(e, AA_U64, name)) {
 241                 if (!inbounds(e, sizeof(u64)))
 242                         return 0;
 243                 if (data)
 244                         *data = le64_to_cpu(get_unaligned((u64 *) e->pos));
 245                 e->pos += sizeof(u64);
 246                 return 1;
 247         }
 248         return 0;
 249 }
 250
 251 static size_t unpack_array(struct aa_ext *e, const char *name)
 252 {
 253         if (unpack_nameX(e, AA_ARRAY, name)) {
 254                 int size;
 255                 if (!inbounds(e, sizeof(u16)))
 256                         return 0;
 257                 size = (int)le16_to_cpu(get_unaligned((u16 *) e->pos));
 258                 e->pos += sizeof(u16);
 259                 return size;
 260         }
 261         return 0;
 262 }
 263
 264 static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
 265 {
 266         if (unpack_nameX(e, AA_BLOB, name)) {
 267                 u32 size;
 268                 if (!inbounds(e, sizeof(u32)))
 269                         return 0;
 270                 size = le32_to_cpu(get_unaligned((u32 *) e->pos));
 271                 e->pos += sizeof(u32);
 272                 if (inbounds(e, (size_t) size)) {
 273                         *blob = e->pos;
 274                         e->pos += size;
 275                         return size;
 276                 }
 277         }
 278         return 0;
 279 }
 280
 281 static int unpack_str(struct aa_ext *e, const char **string, const char *name)
 282 {
 283         char *src_str;
 284         size_t size = 0;
 285         void *pos = e->pos;
 286         *string = NULL;
 287         if (unpack_nameX(e, AA_STRING, name)) {
 288                 size = unpack_u16_chunk(e, &src_str);
 289                 if (size) {
 290                         /* strings are null terminated, length is size - 1 */
 291                         if (src_str[size - 1] != 0)
 292                                 goto fail;
 293                         *string = src_str;
 294                 }
 295         }
 296         return size;
 297
 298 fail:
 299         e->pos = pos;
 300         return 0;
 301 }
 302
 303 static int unpack_strdup(struct aa_ext *e, char **string, const char *name)
 304 {
 305         const char *tmp;
 306         void *pos = e->pos;
 307         int res = unpack_str(e, &tmp, name);
 308         *string = NULL;
 309
 310         if (!res)
 311                 return 0;
 312
 313         *string = kmemdup(tmp, res, GFP_KERNEL);
 314         if (!*string) {
 315                 e->pos = pos;
 316                 return 0;
 317         }
 318
 319         return res;
 320 }
 321
 322 #define DFA_VALID_PERM_MASK             0xffffffff
 323 #define DFA_VALID_PERM2_MASK            0xffffffff
 324
 325 /**
 326  * verify_accept - verify the accept tables of a dfa
 327  * @dfa: dfa to verify accept tables of (NOT NULL)
 328  * @flags: flags governing dfa
 329  *
 330  * Returns: 1 if valid accept tables else 0 if error
 331  */
 332 static bool verify_accept(struct aa_dfa *dfa, int flags)
 333 {
 334         int i;
 335
 336         /* verify accept permissions */
 337         for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
 338                 int mode = ACCEPT_TABLE(dfa)[i];
 339
 340                 if (mode & ~DFA_VALID_PERM_MASK)
 341                         return 0;
 342
 343                 if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK)
 344                         return 0;
 345         }
 346         return 1;
 347 }
 348
 349 /**
 350  * unpack_dfa - unpack a file rule dfa
 351  * @e: serialized data extent information (NOT NULL)
 352  *
 353  * returns dfa or ERR_PTR or NULL if no dfa
 354  */
 355 static struct aa_dfa *unpack_dfa(struct aa_ext *e)
 356 {
 357         char *blob = NULL;
 358         size_t size;
 359         struct aa_dfa *dfa = NULL;
 360
 361         size = unpack_blob(e, &blob, "aadfa");
 362         if (size) {
 363                 /*
 364                  * The dfa is aligned with in the blob to 8 bytes
 365                  * from the beginning of the stream.
 366                  * alignment adjust needed by dfa unpack
 367                  */
 368                 size_t sz = blob - (char *) e->start -
 369                         ((e->pos - e->start) & 7);
 370                 size_t pad = ALIGN(sz, 8) - sz;
 371                 int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) |
 372                         TO_ACCEPT2_FLAG(YYTD_DATA32) | DFA_FLAG_VERIFY_STATES;
 373                 dfa = aa_dfa_unpack(blob + pad, size - pad, flags);
 374
 375                 if (IS_ERR(dfa))
 376                         return dfa;
 377
 378                 if (!verify_accept(dfa, flags))
 379                         goto fail;
 380         }
 381
 382         return dfa;
 383
 384 fail:
 385         aa_put_dfa(dfa);
 386         return ERR_PTR(-EPROTO);
 387 }
 388
 389 /**
 390  * unpack_trans_table - unpack a profile transition table
 391  * @e: serialized data extent information  (NOT NULL)
 392  * @profile: profile to add the accept table to (NOT NULL)
 393  *
 394  * Returns: 1 if table successfully unpacked
 395  */
 396 static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile)
 397 {
 398         void *pos = e->pos;
 399
 400         /* exec table is optional */
 401         if (unpack_nameX(e, AA_STRUCT, "xtable")) {
 402                 int i, size;
 403
 404                 size = unpack_array(e, NULL);
 405                 /* currently 4 exec bits and entries 0-3 are reserved iupcx */
 406                 if (size > 16 - 4)
 407                         goto fail;
 408                 profile->file.trans.table = kzalloc(sizeof(char *) * size,
 409                                                     GFP_KERNEL);
 410                 if (!profile->file.trans.table)
 411                         goto fail;
 412
 413                 profile->file.trans.size = size;
 414                 for (i = 0; i < size; i++) {
 415                         char *str;
 416                         int c, j, pos, size2 = unpack_strdup(e, &str, NULL);
 417                         /* unpack_strdup verifies that the last character is
 418                          * null termination byte.
 419                          */
 420                         if (!size2)
 421                                 goto fail;
 422                         profile->file.trans.table[i] = str;
 423                         /* verify that name doesn't start with space */
 424                         if (isspace(*str))
 425                                 goto fail;
 426
 427                         /* count internal #  of internal \0 */
 428                         for (c = j = 0; j < size2 - 1; j++) {
 429                                 if (!str[j]) {
 430                                         pos = j;
 431                                         c++;
 432                                 }
 433                         }
 434                         if (*str == ':') {
 435                                 /* first character after : must be valid */
 436                                 if (!str[1])
 437                                         goto fail;
 438                                 /* beginning with : requires an embedded \0,
 439                                  * verify that exactly 1 internal \0 exists
 440                                  * trailing \0 already verified by unpack_strdup
 441                                  */
 442                                 if (c == 1)
 443                                         /* convert \0 back to : for label_parse */
 444                                         str[pos] = ':';
 445                                 else if (c > 1)
 446                                         goto fail;
 447                         } else if (c)
 448                                 /* fail - all other cases with embedded \0 */
 449                                 goto fail;
 450                 }
 451                 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
 452                         goto fail;
 453                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 454                         goto fail;
 455         }
 456         return 1;
 457
 458 fail:
 459         aa_free_domain_entries(&profile->file.trans);
 460         e->pos = pos;
 461         return 0;
 462 }
 463
 464 static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile)
 465 {
 466         void *pos = e->pos;
 467
 468         /* rlimits are optional */
 469         if (unpack_nameX(e, AA_STRUCT, "rlimits")) {
 470                 int i, size;
 471                 u32 tmp = 0;
 472                 if (!unpack_u32(e, &tmp, NULL))
 473                         goto fail;
 474                 profile->rlimits.mask = tmp;
 475
 476                 size = unpack_array(e, NULL);
 477                 if (size > RLIM_NLIMITS)
 478                         goto fail;
 479                 for (i = 0; i < size; i++) {
 480                         u64 tmp2 = 0;
 481                         int a = aa_map_resource(i);
 482                         if (!unpack_u64(e, &tmp2, NULL))
 483                                 goto fail;
 484                         profile->rlimits.limits[a].rlim_max = tmp2;
 485                 }
 486                 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
 487                         goto fail;
 488                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 489                         goto fail;
 490         }
 491         return 1;
 492
 493 fail:
 494         e->pos = pos;
 495         return 0;
 496 }
 497
 498 /**
 499  * unpack_profile - unpack a serialized profile
 500  * @e: serialized data extent information (NOT NULL)
 501  *
 502  * NOTE: unpack profile sets audit struct if there is a failure
 503  */
 504 static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
 505 {
 506         struct aa_profile *profile = NULL;
 507         const char *tmpname, *tmpns = NULL, *name = NULL;
 508         const char *info = "failed to unpack profile";
 509         size_t size = 0, ns_len;
 510         int i, error = -EPROTO;
 511         kernel_cap_t tmpcap;
 512         u32 tmp;
 513
 514         *ns_name = NULL;
 515
 516         /* check that we have the right struct being passed */
 517         if (!unpack_nameX(e, AA_STRUCT, "profile"))
 518                 goto fail;
 519         if (!unpack_str(e, &name, NULL))
 520                 goto fail;
 521         if (*name == '\0')
 522                 goto fail;
 523
 524         tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len);
 525         if (tmpns) {
 526           *ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL);
 527                 if (!*ns_name)
 528                         goto fail;
 529                 name = tmpname;
 530         }
 531
 532         profile = aa_alloc_profile(name, NULL, GFP_KERNEL);
 533         if (!profile)
 534                 return ERR_PTR(-ENOMEM);
 535
 536         /* profile renaming is optional */
 537         (void) unpack_str(e, &profile->rename, "rename");
 538
 539         /* attachment string is optional */
 540         (void) unpack_str(e, &profile->attach, "attach");
 541
 542         /* xmatch is optional and may be NULL */
 543         profile->xmatch = unpack_dfa(e);
 544         if (IS_ERR(profile->xmatch)) {
 545                 error = PTR_ERR(profile->xmatch);
 546                 profile->xmatch = NULL;
 547                 goto fail;
 548         }
 549         /* xmatch_len is not optional if xmatch is set */
 550         if (profile->xmatch) {
 551                 if (!unpack_u32(e, &tmp, NULL))
 552                         goto fail;
 553                 profile->xmatch_len = tmp;
 554         }
 555
 556         /* disconnected attachment string is optional */
 557         (void) unpack_str(e, &profile->disconnected, "disconnected");
 558
 559         /* per profile debug flags (complain, audit) */
 560         if (!unpack_nameX(e, AA_STRUCT, "flags"))
 561                 goto fail;
 562         if (!unpack_u32(e, &tmp, NULL))
 563                 goto fail;
 564         if (tmp & PACKED_FLAG_HAT)
 565                 profile->label.flags |= FLAG_HAT;
 566         if (!unpack_u32(e, &tmp, NULL))
 567                 goto fail;
 568         if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG))
 569                 profile->mode = APPARMOR_COMPLAIN;
 570         else if (tmp == PACKED_MODE_KILL)
 571                 profile->mode = APPARMOR_KILL;
 572         else if (tmp == PACKED_MODE_UNCONFINED)
 573                 profile->mode = APPARMOR_UNCONFINED;
 574         if (!unpack_u32(e, &tmp, NULL))
 575                 goto fail;
 576         if (tmp)
 577                 profile->audit = AUDIT_ALL;
 578
 579         if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 580                 goto fail;
 581
 582         /* path_flags is optional */
 583         if (!unpack_u32(e, &profile->path_flags, "path_flags"))
 584                 /* set a default value if path_flags field is not present */
 585                 profile->path_flags = PATH_MEDIATE_DELETED;
 586
 587         if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL))
 588                 goto fail;
 589         if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL))
 590                 goto fail;
 591         if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL))
 592                 goto fail;
 593         if (!unpack_u32(e, &tmpcap.cap[0], NULL))
 594                 goto fail;
 595
 596         if (unpack_nameX(e, AA_STRUCT, "caps64")) {
 597                 /* optional upper half of 64 bit caps */
 598                 if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL))
 599                         goto fail;
 600                 if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL))
 601                         goto fail;
 602                 if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL))
 603                         goto fail;
 604                 if (!unpack_u32(e, &(tmpcap.cap[1]), NULL))
 605                         goto fail;
 606                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 607                         goto fail;
 608         }
 609
 610         if (unpack_nameX(e, AA_STRUCT, "capsx")) {
 611                 /* optional extended caps mediation mask */
 612                 if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL))
 613                         goto fail;
 614                 if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL))
 615                         goto fail;
 616                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 617                         goto fail;
 618         }
 619
 620         if (!unpack_rlimits(e, profile))
 621                 goto fail;
 622
 623         size = unpack_array(e, "net_allowed_af");
 624         if (size) {
 625
 626                 for (i = 0; i < size; i++) {
 627                         /* discard extraneous rules that this kernel will
 628                          * never request
 629                          */
 630                         if (i >= AF_MAX) {
 631                                 u16 tmp;
 632                                 if (!unpack_u16(e, &tmp, NULL) ||
 633                                     !unpack_u16(e, &tmp, NULL) ||
 634                                     !unpack_u16(e, &tmp, NULL))
 635                                         goto fail;
 636                                 continue;
 637                         }
 638                         if (!unpack_u16(e, &profile->net.allow[i], NULL))
 639                                 goto fail;
 640                         if (!unpack_u16(e, &profile->net.audit[i], NULL))
 641                                 goto fail;
 642                         if (!unpack_u16(e, &profile->net.quiet[i], NULL))
 643                                 goto fail;
 644                 }
 645                 if (!unpack_nameX(e, AA_ARRAYEND, NULL))
 646                         goto fail;
 647         }
 648         if (VERSION_CMP(<, e->version, v7)) {
 649                 /* old policy always allowed these too */
 650                 profile->net.allow[AF_UNIX] = 0xffff;
 651                 profile->net.allow[AF_NETLINK] = 0xffff;
 652         }
 653
 654         if (unpack_nameX(e, AA_STRUCT, "policydb")) {
 655                 /* generic policy dfa - optional and may be NULL */
 656                 profile->policy.dfa = unpack_dfa(e);
 657                 if (IS_ERR(profile->policy.dfa)) {
 658                         error = PTR_ERR(profile->policy.dfa);
 659                         profile->policy.dfa = NULL;
 660                         goto fail;
 661                 } else if (!profile->policy.dfa) {
 662                         error = -EPROTO;
 663                         goto fail;
 664                 }
 665                 if (!unpack_u32(e, &profile->policy.start[0], "start"))
 666                         /* default start state */
 667                         profile->policy.start[0] = DFA_START;
 668                 /* setup class index */
 669                 for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) {
 670                         profile->policy.start[i] =
 671                                 aa_dfa_next(profile->policy.dfa,
 672                                             profile->policy.start[0],
 673                                             i);
 674                 }
 675                 if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 676                         goto fail;
 677         } else
 678                 profile->policy.dfa = aa_get_dfa(nulldfa);
 679
 680         /* get file rules */
 681         profile->file.dfa = unpack_dfa(e);
 682         if (IS_ERR(profile->file.dfa)) {
 683                 error = PTR_ERR(profile->file.dfa);
 684                 profile->file.dfa = NULL;
 685                 goto fail;
 686         } else if (profile->file.dfa) {
 687                 if (!unpack_u32(e, &profile->file.start, "dfa_start"))
 688                         /* default start state */
 689                         profile->file.start = DFA_START;
 690         } else if (profile->policy.dfa &&
 691                    profile->policy.start[AA_CLASS_FILE]) {
 692                 profile->file.dfa = aa_get_dfa(profile->policy.dfa);
 693                 profile->file.start = profile->policy.start[AA_CLASS_FILE];
 694         } else
 695                 profile->file.dfa = aa_get_dfa(nulldfa);
 696
 697         if (!unpack_trans_table(e, profile))
 698                 goto fail;
 699
 700         if (!unpack_nameX(e, AA_STRUCTEND, NULL))
 701                 goto fail;
 702
 703         return profile;
 704
 705 fail:
 706         if (profile)
 707                 name = NULL;
 708         else if (!name)
 709                 name = "unknown";
 710         audit_iface(profile, NULL, name, info, e, error);
 711         aa_free_profile(profile);
 712
 713         return ERR_PTR(error);
 714 }
 715
 716 /**
 717  * verify_head - unpack serialized stream header
 718  * @e: serialized data read head (NOT NULL)
 719  * @required: whether the header is required or optional
 720  * @ns: Returns - namespace if one is specified else NULL (NOT NULL)
 721  *
 722  * Returns: error or 0 if header is good
 723  */
 724 static int verify_header(struct aa_ext *e, int required, const char **ns)
 725 {
 726         int error = -EPROTONOSUPPORT;
 727         const char *name = NULL;
 728         *ns = NULL;
 729
 730         /* get the interface version */
 731         if (!unpack_u32(e, &e->version, "version")) {
 732                 if (required) {
 733                         audit_iface(NULL, NULL, NULL, "invalid profile format",
 734                                     e, error);
 735                         return error;
 736                 }
 737         }
 738
 739         /* Check that the interface version is currently supported.
 740          * if not specified use previous version
 741          * Mask off everything that is not kernel abi version
 742          */
 743         if (VERSION_CMP(<, e->version, v5) && VERSION_CMP(>, e->version, v7)) {
 744                 audit_iface(NULL, NULL, NULL, "unsupported interface version",
 745                             e, error);
 746                 return error;
 747         }
 748
 749         /* read the namespace if present */
 750         if (unpack_str(e, &name, "namespace")) {
 751                 if (*name == '\0') {
 752                         audit_iface(NULL, NULL, NULL, "invalid namespace name",
 753                                     e, error);
 754                         return error;
 755                 }
 756                 if (*ns && strcmp(*ns, name))
 757                         audit_iface(NULL, NULL, NULL, "invalid ns change", e,
 758                                     error);
 759                 else if (!*ns)
 760                         *ns = name;
 761         }
 762
 763         return 0;
 764 }
 765
 766 static bool verify_xindex(int xindex, int table_size)
 767 {
 768         int index, xtype;
 769         xtype = xindex & AA_X_TYPE_MASK;
 770         index = xindex & AA_X_INDEX_MASK;
 771         if (xtype == AA_X_TABLE && index >= table_size)
 772                 return 0;
 773         return 1;
 774 }
 775
 776 /* verify dfa xindexes are in range of transition tables */
 777 static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size)
 778 {
 779         int i;
 780         for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) {
 781                 if (!verify_xindex(dfa_user_xindex(dfa, i), table_size))
 782                         return 0;
 783                 if (!verify_xindex(dfa_other_xindex(dfa, i), table_size))
 784                         return 0;
 785         }
 786         return 1;
 787 }
 788
 789 /**
 790  * verify_profile - Do post unpack analysis to verify profile consistency
 791  * @profile: profile to verify (NOT NULL)
 792  *
 793  * Returns: 0 if passes verification else error
 794  */
 795 static int verify_profile(struct aa_profile *profile)
 796 {
 797         if (profile->file.dfa &&
 798             !verify_dfa_xindex(profile->file.dfa,
 799                                profile->file.trans.size)) {
 800                 audit_iface(profile, NULL, NULL,
 801                             "Invalid named transition", NULL, -EPROTO);
 802                 return -EPROTO;
 803         }
 804
 805         return 0;
 806 }
 807
 808 void aa_load_ent_free(struct aa_load_ent *ent)
 809 {
 810         if (ent) {
 811                 aa_put_profile(ent->rename);
 812                 aa_put_profile(ent->old);
 813                 aa_put_profile(ent->new);
 814                 kfree(ent->ns_name);
 815                 kzfree(ent);
 816         }
 817 }
 818
 819 struct aa_load_ent *aa_load_ent_alloc(void)
 820 {
 821         struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL);
 822         if (ent)
 823                 INIT_LIST_HEAD(&ent->list);
 824         return ent;
 825 }
 826
 827 /**
 828  * aa_unpack - unpack packed binary profile(s) data loaded from user space
 829  * @udata: user data copied to kmem  (NOT NULL)
 830  * @size: the size of the user data
 831  * @lh: list to place unpacked profiles in a aa_repl_ws
 832  * @ns: Returns namespace profile is in if specified else NULL (NOT NULL)
 833  *
 834  * Unpack user data and return refcounted allocated profile(s) stored in
 835  * @lh in order of discovery, with the list chain stored in base.list
 836  * or error
 837  *
 838  * Returns: profile(s) on @lh else error pointer if fails to unpack
 839  */
 840 int aa_unpack(void *udata, size_t size, struct list_head *lh, const char **ns)
 841 {
 842         struct aa_load_ent *tmp, *ent;
 843         struct aa_profile *profile = NULL;
 844         int error;
 845         struct aa_ext e = {
 846                 .start = udata,
 847                 .end = udata + size,
 848                 .pos = udata,
 849         };
 850
 851         *ns = NULL;
 852         while (e.pos < e.end) {
 853                 char *ns_name = NULL;
 854                 void *start;
 855                 error = verify_header(&e, e.pos == e.start, ns);
 856                 if (error)
 857                         goto fail;
 858
 859                 start = e.pos;
 860                 profile = unpack_profile(&e, &ns_name);
 861                 if (IS_ERR(profile)) {
 862                         error = PTR_ERR(profile);
 863                         goto fail;
 864                 }
 865
 866                 error = verify_profile(profile);
 867                 if (error)
 868                         goto fail_profile;
 869
 870                 if (aa_g_hash_policy)
 871                         error = aa_calc_profile_hash(profile, e.version, start,
 872                                                      e.pos - start);
 873                 if (error)
 874                         goto fail_profile;
 875
 876                 ent = aa_load_ent_alloc();
 877                 if (!ent) {
 878                         error = -ENOMEM;
 879                         goto fail_profile;
 880                 }
 881
 882                 ent->new = profile;
 883                 ent->ns_name = ns_name;
 884                 list_add_tail(&ent->list, lh);
 885         }
 886
 887         return 0;
 888
 889 fail_profile:
 890         aa_put_profile(profile);
 891
 892 fail:
 893         list_for_each_entry_safe(ent, tmp, lh, list) {
 894                 list_del_init(&ent->list);
 895                 aa_load_ent_free(ent);
 896         }
 897
 898         return error;
 899 }