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 see Documentation/admin-guide/LSM/apparmor.rst 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/path.h" 30 #include "include/policy.h" 31 #include "include/policy_unpack.h" 32 33 #define K_ABI_MASK 0x3ff 34 #define FORCE_COMPLAIN_FLAG 0x800 35 #define VERSION_LT(X, Y) (((X) & K_ABI_MASK) < ((Y) & K_ABI_MASK)) 36 #define VERSION_GT(X, Y) (((X) & K_ABI_MASK) > ((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 aad(&sa)->iface.ns = ns_name; 116 if (new) 117 aad(&sa)->name = new->base.hname; 118 else 119 aad(&sa)->name = name; 120 aad(&sa)->info = info; 121 aad(&sa)->error = error; 122 123 return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb); 124 } 125 126 void __aa_loaddata_update(struct aa_loaddata *data, long revision) 127 { 128 AA_BUG(!data); 129 AA_BUG(!data->ns); 130 AA_BUG(!data->dents[AAFS_LOADDATA_REVISION]); 131 AA_BUG(!mutex_is_locked(&data->ns->lock)); 132 AA_BUG(data->revision > revision); 133 134 data->revision = revision; 135 d_inode(data->dents[AAFS_LOADDATA_DIR])->i_mtime = 136 current_time(d_inode(data->dents[AAFS_LOADDATA_DIR])); 137 d_inode(data->dents[AAFS_LOADDATA_REVISION])->i_mtime = 138 current_time(d_inode(data->dents[AAFS_LOADDATA_REVISION])); 139 } 140 141 bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r) 142 { 143 if (l->size != r->size) 144 return false; 145 if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0) 146 return false; 147 return memcmp(l->data, r->data, r->size) == 0; 148 } 149 150 /* 151 * need to take the ns mutex lock which is NOT safe most places that 152 * put_loaddata is called, so we have to delay freeing it 153 */ 154 static void do_loaddata_free(struct work_struct *work) 155 { 156 struct aa_loaddata *d = container_of(work, struct aa_loaddata, work); 157 struct aa_ns *ns = aa_get_ns(d->ns); 158 159 if (ns) { 160 mutex_lock_nested(&ns->lock, ns->level); 161 __aa_fs_remove_rawdata(d); 162 mutex_unlock(&ns->lock); 163 aa_put_ns(ns); 164 } 165 166 kzfree(d->hash); 167 kfree(d->name); 168 kvfree(d); 169 } 170 171 void aa_loaddata_kref(struct kref *kref) 172 { 173 struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count); 174 175 if (d) { 176 INIT_WORK(&d->work, do_loaddata_free); 177 schedule_work(&d->work); 178 } 179 } 180 181 struct aa_loaddata *aa_loaddata_alloc(size_t size) 182 { 183 struct aa_loaddata *d = kvzalloc(sizeof(*d) + size, GFP_KERNEL); 184 185 if (d == NULL) 186 return ERR_PTR(-ENOMEM); 187 kref_init(&d->count); 188 INIT_LIST_HEAD(&d->list); 189 190 return d; 191 } 192 193 /* test if read will be in packed data bounds */ 194 static bool inbounds(struct aa_ext *e, size_t size) 195 { 196 return (size <= e->end - e->pos); 197 } 198 199 /** 200 * aa_u16_chunck - test and do bounds checking for a u16 size based chunk 201 * @e: serialized data read head (NOT NULL) 202 * @chunk: start address for chunk of data (NOT NULL) 203 * 204 * Returns: the size of chunk found with the read head at the end of the chunk. 205 */ 206 static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk) 207 { 208 size_t size = 0; 209 210 if (!inbounds(e, sizeof(u16))) 211 return 0; 212 size = le16_to_cpu(get_unaligned((__le16 *) e->pos)); 213 e->pos += sizeof(__le16); 214 if (!inbounds(e, size)) 215 return 0; 216 *chunk = e->pos; 217 e->pos += size; 218 return size; 219 } 220 221 /* unpack control byte */ 222 static bool unpack_X(struct aa_ext *e, enum aa_code code) 223 { 224 if (!inbounds(e, 1)) 225 return 0; 226 if (*(u8 *) e->pos != code) 227 return 0; 228 e->pos++; 229 return 1; 230 } 231 232 /** 233 * unpack_nameX - check is the next element is of type X with a name of @name 234 * @e: serialized data extent information (NOT NULL) 235 * @code: type code 236 * @name: name to match to the serialized element. (MAYBE NULL) 237 * 238 * check that the next serialized data element is of type X and has a tag 239 * name @name. If @name is specified then there must be a matching 240 * name element in the stream. If @name is NULL any name element will be 241 * skipped and only the typecode will be tested. 242 * 243 * Returns 1 on success (both type code and name tests match) and the read 244 * head is advanced past the headers 245 * 246 * Returns: 0 if either match fails, the read head does not move 247 */ 248 static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name) 249 { 250 /* 251 * May need to reset pos if name or type doesn't match 252 */ 253 void *pos = e->pos; 254 /* 255 * Check for presence of a tagname, and if present name size 256 * AA_NAME tag value is a u16. 257 */ 258 if (unpack_X(e, AA_NAME)) { 259 char *tag = NULL; 260 size_t size = unpack_u16_chunk(e, &tag); 261 /* if a name is specified it must match. otherwise skip tag */ 262 if (name && (!size || strcmp(name, tag))) 263 goto fail; 264 } else if (name) { 265 /* if a name is specified and there is no name tag fail */ 266 goto fail; 267 } 268 269 /* now check if type code matches */ 270 if (unpack_X(e, code)) 271 return 1; 272 273 fail: 274 e->pos = pos; 275 return 0; 276 } 277 278 static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name) 279 { 280 if (unpack_nameX(e, AA_U32, name)) { 281 if (!inbounds(e, sizeof(u32))) 282 return 0; 283 if (data) 284 *data = le32_to_cpu(get_unaligned((__le32 *) e->pos)); 285 e->pos += sizeof(u32); 286 return 1; 287 } 288 return 0; 289 } 290 291 static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name) 292 { 293 if (unpack_nameX(e, AA_U64, name)) { 294 if (!inbounds(e, sizeof(u64))) 295 return 0; 296 if (data) 297 *data = le64_to_cpu(get_unaligned((__le64 *) e->pos)); 298 e->pos += sizeof(u64); 299 return 1; 300 } 301 return 0; 302 } 303 304 static size_t unpack_array(struct aa_ext *e, const char *name) 305 { 306 if (unpack_nameX(e, AA_ARRAY, name)) { 307 int size; 308 if (!inbounds(e, sizeof(u16))) 309 return 0; 310 size = (int)le16_to_cpu(get_unaligned((__le16 *) e->pos)); 311 e->pos += sizeof(u16); 312 return size; 313 } 314 return 0; 315 } 316 317 static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name) 318 { 319 if (unpack_nameX(e, AA_BLOB, name)) { 320 u32 size; 321 if (!inbounds(e, sizeof(u32))) 322 return 0; 323 size = le32_to_cpu(get_unaligned((__le32 *) e->pos)); 324 e->pos += sizeof(u32); 325 if (inbounds(e, (size_t) size)) { 326 *blob = e->pos; 327 e->pos += size; 328 return size; 329 } 330 } 331 return 0; 332 } 333 334 static int unpack_str(struct aa_ext *e, const char **string, const char *name) 335 { 336 char *src_str; 337 size_t size = 0; 338 void *pos = e->pos; 339 *string = NULL; 340 if (unpack_nameX(e, AA_STRING, name)) { 341 size = unpack_u16_chunk(e, &src_str); 342 if (size) { 343 /* strings are null terminated, length is size - 1 */ 344 if (src_str[size - 1] != 0) 345 goto fail; 346 *string = src_str; 347 } 348 } 349 return size; 350 351 fail: 352 e->pos = pos; 353 return 0; 354 } 355 356 static int unpack_strdup(struct aa_ext *e, char **string, const char *name) 357 { 358 const char *tmp; 359 void *pos = e->pos; 360 int res = unpack_str(e, &tmp, name); 361 *string = NULL; 362 363 if (!res) 364 return 0; 365 366 *string = kmemdup(tmp, res, GFP_KERNEL); 367 if (!*string) { 368 e->pos = pos; 369 return 0; 370 } 371 372 return res; 373 } 374 375 #define DFA_VALID_PERM_MASK 0xffffffff 376 #define DFA_VALID_PERM2_MASK 0xffffffff 377 378 /** 379 * verify_accept - verify the accept tables of a dfa 380 * @dfa: dfa to verify accept tables of (NOT NULL) 381 * @flags: flags governing dfa 382 * 383 * Returns: 1 if valid accept tables else 0 if error 384 */ 385 static bool verify_accept(struct aa_dfa *dfa, int flags) 386 { 387 int i; 388 389 /* verify accept permissions */ 390 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { 391 int mode = ACCEPT_TABLE(dfa)[i]; 392 393 if (mode & ~DFA_VALID_PERM_MASK) 394 return 0; 395 396 if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK) 397 return 0; 398 } 399 return 1; 400 } 401 402 /** 403 * unpack_dfa - unpack a file rule dfa 404 * @e: serialized data extent information (NOT NULL) 405 * 406 * returns dfa or ERR_PTR or NULL if no dfa 407 */ 408 static struct aa_dfa *unpack_dfa(struct aa_ext *e) 409 { 410 char *blob = NULL; 411 size_t size; 412 struct aa_dfa *dfa = NULL; 413 414 size = unpack_blob(e, &blob, "aadfa"); 415 if (size) { 416 /* 417 * The dfa is aligned with in the blob to 8 bytes 418 * from the beginning of the stream. 419 * alignment adjust needed by dfa unpack 420 */ 421 size_t sz = blob - (char *) e->start - 422 ((e->pos - e->start) & 7); 423 size_t pad = ALIGN(sz, 8) - sz; 424 int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) | 425 TO_ACCEPT2_FLAG(YYTD_DATA32) | DFA_FLAG_VERIFY_STATES; 426 dfa = aa_dfa_unpack(blob + pad, size - pad, flags); 427 428 if (IS_ERR(dfa)) 429 return dfa; 430 431 if (!verify_accept(dfa, flags)) 432 goto fail; 433 } 434 435 return dfa; 436 437 fail: 438 aa_put_dfa(dfa); 439 return ERR_PTR(-EPROTO); 440 } 441 442 /** 443 * unpack_trans_table - unpack a profile transition table 444 * @e: serialized data extent information (NOT NULL) 445 * @profile: profile to add the accept table to (NOT NULL) 446 * 447 * Returns: 1 if table successfully unpacked 448 */ 449 static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile) 450 { 451 void *saved_pos = e->pos; 452 453 /* exec table is optional */ 454 if (unpack_nameX(e, AA_STRUCT, "xtable")) { 455 int i, size; 456 457 size = unpack_array(e, NULL); 458 /* currently 4 exec bits and entries 0-3 are reserved iupcx */ 459 if (size > 16 - 4) 460 goto fail; 461 profile->file.trans.table = kzalloc(sizeof(char *) * size, 462 GFP_KERNEL); 463 if (!profile->file.trans.table) 464 goto fail; 465 466 profile->file.trans.size = size; 467 for (i = 0; i < size; i++) { 468 char *str; 469 int c, j, pos, size2 = unpack_strdup(e, &str, NULL); 470 /* unpack_strdup verifies that the last character is 471 * null termination byte. 472 */ 473 if (!size2) 474 goto fail; 475 profile->file.trans.table[i] = str; 476 /* verify that name doesn't start with space */ 477 if (isspace(*str)) 478 goto fail; 479 480 /* count internal # of internal \0 */ 481 for (c = j = 0; j < size2 - 1; j++) { 482 if (!str[j]) { 483 pos = j; 484 c++; 485 } 486 } 487 if (*str == ':') { 488 /* first character after : must be valid */ 489 if (!str[1]) 490 goto fail; 491 /* beginning with : requires an embedded \0, 492 * verify that exactly 1 internal \0 exists 493 * trailing \0 already verified by unpack_strdup 494 * 495 * convert \0 back to : for label_parse 496 */ 497 if (c == 1) 498 str[pos] = ':'; 499 else if (c > 1) 500 goto fail; 501 } else if (c) 502 /* fail - all other cases with embedded \0 */ 503 goto fail; 504 } 505 if (!unpack_nameX(e, AA_ARRAYEND, NULL)) 506 goto fail; 507 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) 508 goto fail; 509 } 510 return 1; 511 512 fail: 513 aa_free_domain_entries(&profile->file.trans); 514 e->pos = saved_pos; 515 return 0; 516 } 517 518 static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile) 519 { 520 void *pos = e->pos; 521 522 /* rlimits are optional */ 523 if (unpack_nameX(e, AA_STRUCT, "rlimits")) { 524 int i, size; 525 u32 tmp = 0; 526 if (!unpack_u32(e, &tmp, NULL)) 527 goto fail; 528 profile->rlimits.mask = tmp; 529 530 size = unpack_array(e, NULL); 531 if (size > RLIM_NLIMITS) 532 goto fail; 533 for (i = 0; i < size; i++) { 534 u64 tmp2 = 0; 535 int a = aa_map_resource(i); 536 if (!unpack_u64(e, &tmp2, NULL)) 537 goto fail; 538 profile->rlimits.limits[a].rlim_max = tmp2; 539 } 540 if (!unpack_nameX(e, AA_ARRAYEND, NULL)) 541 goto fail; 542 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) 543 goto fail; 544 } 545 return 1; 546 547 fail: 548 e->pos = pos; 549 return 0; 550 } 551 552 static void *kvmemdup(const void *src, size_t len) 553 { 554 void *p = kvmalloc(len, GFP_KERNEL); 555 556 if (p) 557 memcpy(p, src, len); 558 return p; 559 } 560 561 static u32 strhash(const void *data, u32 len, u32 seed) 562 { 563 const char * const *key = data; 564 565 return jhash(*key, strlen(*key), seed); 566 } 567 568 static int datacmp(struct rhashtable_compare_arg *arg, const void *obj) 569 { 570 const struct aa_data *data = obj; 571 const char * const *key = arg->key; 572 573 return strcmp(data->key, *key); 574 } 575 576 /** 577 * unpack_profile - unpack a serialized profile 578 * @e: serialized data extent information (NOT NULL) 579 * 580 * NOTE: unpack profile sets audit struct if there is a failure 581 */ 582 static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name) 583 { 584 struct aa_profile *profile = NULL; 585 const char *tmpname, *tmpns = NULL, *name = NULL; 586 const char *info = "failed to unpack profile"; 587 size_t ns_len; 588 struct rhashtable_params params = { 0 }; 589 char *key = NULL; 590 struct aa_data *data; 591 int i, error = -EPROTO; 592 kernel_cap_t tmpcap; 593 u32 tmp; 594 595 *ns_name = NULL; 596 597 /* check that we have the right struct being passed */ 598 if (!unpack_nameX(e, AA_STRUCT, "profile")) 599 goto fail; 600 if (!unpack_str(e, &name, NULL)) 601 goto fail; 602 if (*name == '\0') 603 goto fail; 604 605 tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len); 606 if (tmpns) { 607 *ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL); 608 if (!*ns_name) { 609 info = "out of memory"; 610 goto fail; 611 } 612 name = tmpname; 613 } 614 615 profile = aa_alloc_profile(name, NULL, GFP_KERNEL); 616 if (!profile) 617 return ERR_PTR(-ENOMEM); 618 619 /* profile renaming is optional */ 620 (void) unpack_str(e, &profile->rename, "rename"); 621 622 /* attachment string is optional */ 623 (void) unpack_str(e, &profile->attach, "attach"); 624 625 /* xmatch is optional and may be NULL */ 626 profile->xmatch = unpack_dfa(e); 627 if (IS_ERR(profile->xmatch)) { 628 error = PTR_ERR(profile->xmatch); 629 profile->xmatch = NULL; 630 info = "bad xmatch"; 631 goto fail; 632 } 633 /* xmatch_len is not optional if xmatch is set */ 634 if (profile->xmatch) { 635 if (!unpack_u32(e, &tmp, NULL)) { 636 info = "missing xmatch len"; 637 goto fail; 638 } 639 profile->xmatch_len = tmp; 640 } 641 642 /* disconnected attachment string is optional */ 643 (void) unpack_str(e, &profile->disconnected, "disconnected"); 644 645 /* per profile debug flags (complain, audit) */ 646 if (!unpack_nameX(e, AA_STRUCT, "flags")) { 647 info = "profile missing flags"; 648 goto fail; 649 } 650 info = "failed to unpack profile flags"; 651 if (!unpack_u32(e, &tmp, NULL)) 652 goto fail; 653 if (tmp & PACKED_FLAG_HAT) 654 profile->label.flags |= FLAG_HAT; 655 if (!unpack_u32(e, &tmp, NULL)) 656 goto fail; 657 if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG)) 658 profile->mode = APPARMOR_COMPLAIN; 659 else if (tmp == PACKED_MODE_KILL) 660 profile->mode = APPARMOR_KILL; 661 else if (tmp == PACKED_MODE_UNCONFINED) 662 profile->mode = APPARMOR_UNCONFINED; 663 if (!unpack_u32(e, &tmp, NULL)) 664 goto fail; 665 if (tmp) 666 profile->audit = AUDIT_ALL; 667 668 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) 669 goto fail; 670 671 /* path_flags is optional */ 672 if (unpack_u32(e, &profile->path_flags, "path_flags")) 673 profile->path_flags |= profile->label.flags & 674 PATH_MEDIATE_DELETED; 675 else 676 /* set a default value if path_flags field is not present */ 677 profile->path_flags = PATH_MEDIATE_DELETED; 678 679 info = "failed to unpack profile capabilities"; 680 if (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL)) 681 goto fail; 682 if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL)) 683 goto fail; 684 if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL)) 685 goto fail; 686 if (!unpack_u32(e, &tmpcap.cap[0], NULL)) 687 goto fail; 688 689 info = "failed to unpack upper profile capabilities"; 690 if (unpack_nameX(e, AA_STRUCT, "caps64")) { 691 /* optional upper half of 64 bit caps */ 692 if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL)) 693 goto fail; 694 if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL)) 695 goto fail; 696 if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL)) 697 goto fail; 698 if (!unpack_u32(e, &(tmpcap.cap[1]), NULL)) 699 goto fail; 700 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) 701 goto fail; 702 } 703 704 info = "failed to unpack extended profile capabilities"; 705 if (unpack_nameX(e, AA_STRUCT, "capsx")) { 706 /* optional extended caps mediation mask */ 707 if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL)) 708 goto fail; 709 if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL)) 710 goto fail; 711 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) 712 goto fail; 713 } 714 715 if (!unpack_rlimits(e, profile)) { 716 info = "failed to unpack profile rlimits"; 717 goto fail; 718 } 719 720 if (unpack_nameX(e, AA_STRUCT, "policydb")) { 721 /* generic policy dfa - optional and may be NULL */ 722 info = "failed to unpack policydb"; 723 profile->policy.dfa = unpack_dfa(e); 724 if (IS_ERR(profile->policy.dfa)) { 725 error = PTR_ERR(profile->policy.dfa); 726 profile->policy.dfa = NULL; 727 goto fail; 728 } else if (!profile->policy.dfa) { 729 error = -EPROTO; 730 goto fail; 731 } 732 if (!unpack_u32(e, &profile->policy.start[0], "start")) 733 /* default start state */ 734 profile->policy.start[0] = DFA_START; 735 /* setup class index */ 736 for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) { 737 profile->policy.start[i] = 738 aa_dfa_next(profile->policy.dfa, 739 profile->policy.start[0], 740 i); 741 } 742 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) 743 goto fail; 744 } else 745 profile->policy.dfa = aa_get_dfa(nulldfa); 746 747 /* get file rules */ 748 profile->file.dfa = unpack_dfa(e); 749 if (IS_ERR(profile->file.dfa)) { 750 error = PTR_ERR(profile->file.dfa); 751 profile->file.dfa = NULL; 752 info = "failed to unpack profile file rules"; 753 goto fail; 754 } else if (profile->file.dfa) { 755 if (!unpack_u32(e, &profile->file.start, "dfa_start")) 756 /* default start state */ 757 profile->file.start = DFA_START; 758 } else if (profile->policy.dfa && 759 profile->policy.start[AA_CLASS_FILE]) { 760 profile->file.dfa = aa_get_dfa(profile->policy.dfa); 761 profile->file.start = profile->policy.start[AA_CLASS_FILE]; 762 } else 763 profile->file.dfa = aa_get_dfa(nulldfa); 764 765 if (!unpack_trans_table(e, profile)) { 766 info = "failed to unpack profile transition table"; 767 goto fail; 768 } 769 770 if (unpack_nameX(e, AA_STRUCT, "data")) { 771 info = "out of memory"; 772 profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL); 773 if (!profile->data) 774 goto fail; 775 776 params.nelem_hint = 3; 777 params.key_len = sizeof(void *); 778 params.key_offset = offsetof(struct aa_data, key); 779 params.head_offset = offsetof(struct aa_data, head); 780 params.hashfn = strhash; 781 params.obj_cmpfn = datacmp; 782 783 if (rhashtable_init(profile->data, ¶ms)) { 784 info = "failed to init key, value hash table"; 785 goto fail; 786 } 787 788 while (unpack_strdup(e, &key, NULL)) { 789 data = kzalloc(sizeof(*data), GFP_KERNEL); 790 if (!data) { 791 kzfree(key); 792 goto fail; 793 } 794 795 data->key = key; 796 data->size = unpack_blob(e, &data->data, NULL); 797 data->data = kvmemdup(data->data, data->size); 798 if (data->size && !data->data) { 799 kzfree(data->key); 800 kzfree(data); 801 goto fail; 802 } 803 804 rhashtable_insert_fast(profile->data, &data->head, 805 profile->data->p); 806 } 807 808 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) { 809 info = "failed to unpack end of key, value data table"; 810 goto fail; 811 } 812 } 813 814 if (!unpack_nameX(e, AA_STRUCTEND, NULL)) { 815 info = "failed to unpack end of profile"; 816 goto fail; 817 } 818 819 return profile; 820 821 fail: 822 if (profile) 823 name = NULL; 824 else if (!name) 825 name = "unknown"; 826 audit_iface(profile, NULL, name, info, e, error); 827 aa_free_profile(profile); 828 829 return ERR_PTR(error); 830 } 831 832 /** 833 * verify_head - unpack serialized stream header 834 * @e: serialized data read head (NOT NULL) 835 * @required: whether the header is required or optional 836 * @ns: Returns - namespace if one is specified else NULL (NOT NULL) 837 * 838 * Returns: error or 0 if header is good 839 */ 840 static int verify_header(struct aa_ext *e, int required, const char **ns) 841 { 842 int error = -EPROTONOSUPPORT; 843 const char *name = NULL; 844 *ns = NULL; 845 846 /* get the interface version */ 847 if (!unpack_u32(e, &e->version, "version")) { 848 if (required) { 849 audit_iface(NULL, NULL, NULL, "invalid profile format", 850 e, error); 851 return error; 852 } 853 } 854 855 /* Check that the interface version is currently supported. 856 * if not specified use previous version 857 * Mask off everything that is not kernel abi version 858 */ 859 if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v7)) { 860 audit_iface(NULL, NULL, NULL, "unsupported interface version", 861 e, error); 862 return error; 863 } 864 865 /* read the namespace if present */ 866 if (unpack_str(e, &name, "namespace")) { 867 if (*name == '\0') { 868 audit_iface(NULL, NULL, NULL, "invalid namespace name", 869 e, error); 870 return error; 871 } 872 if (*ns && strcmp(*ns, name)) 873 audit_iface(NULL, NULL, NULL, "invalid ns change", e, 874 error); 875 else if (!*ns) 876 *ns = name; 877 } 878 879 return 0; 880 } 881 882 static bool verify_xindex(int xindex, int table_size) 883 { 884 int index, xtype; 885 xtype = xindex & AA_X_TYPE_MASK; 886 index = xindex & AA_X_INDEX_MASK; 887 if (xtype == AA_X_TABLE && index >= table_size) 888 return 0; 889 return 1; 890 } 891 892 /* verify dfa xindexes are in range of transition tables */ 893 static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size) 894 { 895 int i; 896 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { 897 if (!verify_xindex(dfa_user_xindex(dfa, i), table_size)) 898 return 0; 899 if (!verify_xindex(dfa_other_xindex(dfa, i), table_size)) 900 return 0; 901 } 902 return 1; 903 } 904 905 /** 906 * verify_profile - Do post unpack analysis to verify profile consistency 907 * @profile: profile to verify (NOT NULL) 908 * 909 * Returns: 0 if passes verification else error 910 */ 911 static int verify_profile(struct aa_profile *profile) 912 { 913 if (profile->file.dfa && 914 !verify_dfa_xindex(profile->file.dfa, 915 profile->file.trans.size)) { 916 audit_iface(profile, NULL, NULL, "Invalid named transition", 917 NULL, -EPROTO); 918 return -EPROTO; 919 } 920 921 return 0; 922 } 923 924 void aa_load_ent_free(struct aa_load_ent *ent) 925 { 926 if (ent) { 927 aa_put_profile(ent->rename); 928 aa_put_profile(ent->old); 929 aa_put_profile(ent->new); 930 kfree(ent->ns_name); 931 kzfree(ent); 932 } 933 } 934 935 struct aa_load_ent *aa_load_ent_alloc(void) 936 { 937 struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL); 938 if (ent) 939 INIT_LIST_HEAD(&ent->list); 940 return ent; 941 } 942 943 /** 944 * aa_unpack - unpack packed binary profile(s) data loaded from user space 945 * @udata: user data copied to kmem (NOT NULL) 946 * @lh: list to place unpacked profiles in a aa_repl_ws 947 * @ns: Returns namespace profile is in if specified else NULL (NOT NULL) 948 * 949 * Unpack user data and return refcounted allocated profile(s) stored in 950 * @lh in order of discovery, with the list chain stored in base.list 951 * or error 952 * 953 * Returns: profile(s) on @lh else error pointer if fails to unpack 954 */ 955 int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, 956 const char **ns) 957 { 958 struct aa_load_ent *tmp, *ent; 959 struct aa_profile *profile = NULL; 960 int error; 961 struct aa_ext e = { 962 .start = udata->data, 963 .end = udata->data + udata->size, 964 .pos = udata->data, 965 }; 966 967 *ns = NULL; 968 while (e.pos < e.end) { 969 char *ns_name = NULL; 970 void *start; 971 error = verify_header(&e, e.pos == e.start, ns); 972 if (error) 973 goto fail; 974 975 start = e.pos; 976 profile = unpack_profile(&e, &ns_name); 977 if (IS_ERR(profile)) { 978 error = PTR_ERR(profile); 979 goto fail; 980 } 981 982 error = verify_profile(profile); 983 if (error) 984 goto fail_profile; 985 986 if (aa_g_hash_policy) 987 error = aa_calc_profile_hash(profile, e.version, start, 988 e.pos - start); 989 if (error) 990 goto fail_profile; 991 992 ent = aa_load_ent_alloc(); 993 if (!ent) { 994 error = -ENOMEM; 995 goto fail_profile; 996 } 997 998 ent->new = profile; 999 ent->ns_name = ns_name; 1000 list_add_tail(&ent->list, lh); 1001 } 1002 udata->abi = e.version & K_ABI_MASK; 1003 if (aa_g_hash_policy) { 1004 udata->hash = aa_calc_hash(udata->data, udata->size); 1005 if (IS_ERR(udata->hash)) { 1006 error = PTR_ERR(udata->hash); 1007 udata->hash = NULL; 1008 goto fail; 1009 } 1010 } 1011 return 0; 1012 1013 fail_profile: 1014 aa_put_profile(profile); 1015 1016 fail: 1017 list_for_each_entry_safe(ent, tmp, lh, list) { 1018 list_del_init(&ent->list); 1019 aa_load_ent_free(ent); 1020 } 1021 1022 return error; 1023 } 1024