1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AppArmor security module 4 * 5 * This file contains AppArmor functions for unpacking policy loaded from 6 * userspace. 7 * 8 * Copyright (C) 1998-2008 Novell/SUSE 9 * Copyright 2009-2010 Canonical Ltd. 10 * 11 * AppArmor uses a serialized binary format for loading policy. To find 12 * policy format documentation see Documentation/admin-guide/LSM/apparmor.rst 13 * All policy is validated before it is used. 14 */ 15 16 #include <asm/unaligned.h> 17 #include <kunit/visibility.h> 18 #include <linux/ctype.h> 19 #include <linux/errno.h> 20 #include <linux/zstd.h> 21 22 #include "include/apparmor.h" 23 #include "include/audit.h" 24 #include "include/cred.h" 25 #include "include/crypto.h" 26 #include "include/file.h" 27 #include "include/match.h" 28 #include "include/path.h" 29 #include "include/policy.h" 30 #include "include/policy_unpack.h" 31 #include "include/policy_compat.h" 32 33 /* audit callback for unpack fields */ 34 static void audit_cb(struct audit_buffer *ab, void *va) 35 { 36 struct common_audit_data *sa = va; 37 38 if (aad(sa)->iface.ns) { 39 audit_log_format(ab, " ns="); 40 audit_log_untrustedstring(ab, aad(sa)->iface.ns); 41 } 42 if (aad(sa)->name) { 43 audit_log_format(ab, " name="); 44 audit_log_untrustedstring(ab, aad(sa)->name); 45 } 46 if (aad(sa)->iface.pos) 47 audit_log_format(ab, " offset=%ld", aad(sa)->iface.pos); 48 } 49 50 /** 51 * audit_iface - do audit message for policy unpacking/load/replace/remove 52 * @new: profile if it has been allocated (MAYBE NULL) 53 * @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL) 54 * @name: name of the profile being manipulated (MAYBE NULL) 55 * @info: any extra info about the failure (MAYBE NULL) 56 * @e: buffer position info 57 * @error: error code 58 * 59 * Returns: %0 or error 60 */ 61 static int audit_iface(struct aa_profile *new, const char *ns_name, 62 const char *name, const char *info, struct aa_ext *e, 63 int error) 64 { 65 struct aa_profile *profile = labels_profile(aa_current_raw_label()); 66 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE, NULL); 67 if (e) 68 aad(&sa)->iface.pos = e->pos - e->start; 69 aad(&sa)->iface.ns = ns_name; 70 if (new) 71 aad(&sa)->name = new->base.hname; 72 else 73 aad(&sa)->name = name; 74 aad(&sa)->info = info; 75 aad(&sa)->error = error; 76 77 return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb); 78 } 79 80 void __aa_loaddata_update(struct aa_loaddata *data, long revision) 81 { 82 AA_BUG(!data); 83 AA_BUG(!data->ns); 84 AA_BUG(!mutex_is_locked(&data->ns->lock)); 85 AA_BUG(data->revision > revision); 86 87 data->revision = revision; 88 if ((data->dents[AAFS_LOADDATA_REVISION])) { 89 d_inode(data->dents[AAFS_LOADDATA_DIR])->i_mtime = 90 current_time(d_inode(data->dents[AAFS_LOADDATA_DIR])); 91 d_inode(data->dents[AAFS_LOADDATA_REVISION])->i_mtime = 92 current_time(d_inode(data->dents[AAFS_LOADDATA_REVISION])); 93 } 94 } 95 96 bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r) 97 { 98 if (l->size != r->size) 99 return false; 100 if (l->compressed_size != r->compressed_size) 101 return false; 102 if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0) 103 return false; 104 return memcmp(l->data, r->data, r->compressed_size ?: r->size) == 0; 105 } 106 107 /* 108 * need to take the ns mutex lock which is NOT safe most places that 109 * put_loaddata is called, so we have to delay freeing it 110 */ 111 static void do_loaddata_free(struct work_struct *work) 112 { 113 struct aa_loaddata *d = container_of(work, struct aa_loaddata, work); 114 struct aa_ns *ns = aa_get_ns(d->ns); 115 116 if (ns) { 117 mutex_lock_nested(&ns->lock, ns->level); 118 __aa_fs_remove_rawdata(d); 119 mutex_unlock(&ns->lock); 120 aa_put_ns(ns); 121 } 122 123 kfree_sensitive(d->hash); 124 kfree_sensitive(d->name); 125 kvfree(d->data); 126 kfree_sensitive(d); 127 } 128 129 void aa_loaddata_kref(struct kref *kref) 130 { 131 struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count); 132 133 if (d) { 134 INIT_WORK(&d->work, do_loaddata_free); 135 schedule_work(&d->work); 136 } 137 } 138 139 struct aa_loaddata *aa_loaddata_alloc(size_t size) 140 { 141 struct aa_loaddata *d; 142 143 d = kzalloc(sizeof(*d), GFP_KERNEL); 144 if (d == NULL) 145 return ERR_PTR(-ENOMEM); 146 d->data = kvzalloc(size, GFP_KERNEL); 147 if (!d->data) { 148 kfree(d); 149 return ERR_PTR(-ENOMEM); 150 } 151 kref_init(&d->count); 152 INIT_LIST_HEAD(&d->list); 153 154 return d; 155 } 156 157 /* test if read will be in packed data bounds */ 158 VISIBLE_IF_KUNIT bool aa_inbounds(struct aa_ext *e, size_t size) 159 { 160 return (size <= e->end - e->pos); 161 } 162 EXPORT_SYMBOL_IF_KUNIT(aa_inbounds); 163 164 static void *kvmemdup(const void *src, size_t len) 165 { 166 void *p = kvmalloc(len, GFP_KERNEL); 167 168 if (p) 169 memcpy(p, src, len); 170 return p; 171 } 172 173 /** 174 * aa_unpack_u16_chunk - test and do bounds checking for a u16 size based chunk 175 * @e: serialized data read head (NOT NULL) 176 * @chunk: start address for chunk of data (NOT NULL) 177 * 178 * Returns: the size of chunk found with the read head at the end of the chunk. 179 */ 180 VISIBLE_IF_KUNIT size_t aa_unpack_u16_chunk(struct aa_ext *e, char **chunk) 181 { 182 size_t size = 0; 183 void *pos = e->pos; 184 185 if (!aa_inbounds(e, sizeof(u16))) 186 goto fail; 187 size = le16_to_cpu(get_unaligned((__le16 *) e->pos)); 188 e->pos += sizeof(__le16); 189 if (!aa_inbounds(e, size)) 190 goto fail; 191 *chunk = e->pos; 192 e->pos += size; 193 return size; 194 195 fail: 196 e->pos = pos; 197 return 0; 198 } 199 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u16_chunk); 200 201 /* unpack control byte */ 202 VISIBLE_IF_KUNIT bool aa_unpack_X(struct aa_ext *e, enum aa_code code) 203 { 204 if (!aa_inbounds(e, 1)) 205 return false; 206 if (*(u8 *) e->pos != code) 207 return false; 208 e->pos++; 209 return true; 210 } 211 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_X); 212 213 /** 214 * aa_unpack_nameX - check is the next element is of type X with a name of @name 215 * @e: serialized data extent information (NOT NULL) 216 * @code: type code 217 * @name: name to match to the serialized element. (MAYBE NULL) 218 * 219 * check that the next serialized data element is of type X and has a tag 220 * name @name. If @name is specified then there must be a matching 221 * name element in the stream. If @name is NULL any name element will be 222 * skipped and only the typecode will be tested. 223 * 224 * Returns true on success (both type code and name tests match) and the read 225 * head is advanced past the headers 226 * 227 * Returns: false if either match fails, the read head does not move 228 */ 229 VISIBLE_IF_KUNIT bool aa_unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name) 230 { 231 /* 232 * May need to reset pos if name or type doesn't match 233 */ 234 void *pos = e->pos; 235 /* 236 * Check for presence of a tagname, and if present name size 237 * AA_NAME tag value is a u16. 238 */ 239 if (aa_unpack_X(e, AA_NAME)) { 240 char *tag = NULL; 241 size_t size = aa_unpack_u16_chunk(e, &tag); 242 /* if a name is specified it must match. otherwise skip tag */ 243 if (name && (!size || tag[size-1] != '\0' || strcmp(name, tag))) 244 goto fail; 245 } else if (name) { 246 /* if a name is specified and there is no name tag fail */ 247 goto fail; 248 } 249 250 /* now check if type code matches */ 251 if (aa_unpack_X(e, code)) 252 return true; 253 254 fail: 255 e->pos = pos; 256 return false; 257 } 258 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_nameX); 259 260 static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name) 261 { 262 void *pos = e->pos; 263 264 if (aa_unpack_nameX(e, AA_U8, name)) { 265 if (!aa_inbounds(e, sizeof(u8))) 266 goto fail; 267 if (data) 268 *data = *((u8 *)e->pos); 269 e->pos += sizeof(u8); 270 return true; 271 } 272 273 fail: 274 e->pos = pos; 275 return false; 276 } 277 278 VISIBLE_IF_KUNIT bool aa_unpack_u32(struct aa_ext *e, u32 *data, const char *name) 279 { 280 void *pos = e->pos; 281 282 if (aa_unpack_nameX(e, AA_U32, name)) { 283 if (!aa_inbounds(e, sizeof(u32))) 284 goto fail; 285 if (data) 286 *data = le32_to_cpu(get_unaligned((__le32 *) e->pos)); 287 e->pos += sizeof(u32); 288 return true; 289 } 290 291 fail: 292 e->pos = pos; 293 return false; 294 } 295 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u32); 296 297 VISIBLE_IF_KUNIT bool aa_unpack_u64(struct aa_ext *e, u64 *data, const char *name) 298 { 299 void *pos = e->pos; 300 301 if (aa_unpack_nameX(e, AA_U64, name)) { 302 if (!aa_inbounds(e, sizeof(u64))) 303 goto fail; 304 if (data) 305 *data = le64_to_cpu(get_unaligned((__le64 *) e->pos)); 306 e->pos += sizeof(u64); 307 return true; 308 } 309 310 fail: 311 e->pos = pos; 312 return false; 313 } 314 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u64); 315 316 VISIBLE_IF_KUNIT bool aa_unpack_array(struct aa_ext *e, const char *name, u16 *size) 317 { 318 void *pos = e->pos; 319 320 if (aa_unpack_nameX(e, AA_ARRAY, name)) { 321 if (!aa_inbounds(e, sizeof(u16))) 322 goto fail; 323 *size = le16_to_cpu(get_unaligned((__le16 *) e->pos)); 324 e->pos += sizeof(u16); 325 return true; 326 } 327 328 fail: 329 e->pos = pos; 330 return false; 331 } 332 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_array); 333 334 VISIBLE_IF_KUNIT size_t aa_unpack_blob(struct aa_ext *e, char **blob, const char *name) 335 { 336 void *pos = e->pos; 337 338 if (aa_unpack_nameX(e, AA_BLOB, name)) { 339 u32 size; 340 if (!aa_inbounds(e, sizeof(u32))) 341 goto fail; 342 size = le32_to_cpu(get_unaligned((__le32 *) e->pos)); 343 e->pos += sizeof(u32); 344 if (aa_inbounds(e, (size_t) size)) { 345 *blob = e->pos; 346 e->pos += size; 347 return size; 348 } 349 } 350 351 fail: 352 e->pos = pos; 353 return 0; 354 } 355 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_blob); 356 357 VISIBLE_IF_KUNIT int aa_unpack_str(struct aa_ext *e, const char **string, const char *name) 358 { 359 char *src_str; 360 size_t size = 0; 361 void *pos = e->pos; 362 *string = NULL; 363 if (aa_unpack_nameX(e, AA_STRING, name)) { 364 size = aa_unpack_u16_chunk(e, &src_str); 365 if (size) { 366 /* strings are null terminated, length is size - 1 */ 367 if (src_str[size - 1] != 0) 368 goto fail; 369 *string = src_str; 370 371 return size; 372 } 373 } 374 375 fail: 376 e->pos = pos; 377 return 0; 378 } 379 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_str); 380 381 VISIBLE_IF_KUNIT int aa_unpack_strdup(struct aa_ext *e, char **string, const char *name) 382 { 383 const char *tmp; 384 void *pos = e->pos; 385 int res = aa_unpack_str(e, &tmp, name); 386 *string = NULL; 387 388 if (!res) 389 return 0; 390 391 *string = kmemdup(tmp, res, GFP_KERNEL); 392 if (!*string) { 393 e->pos = pos; 394 return 0; 395 } 396 397 return res; 398 } 399 EXPORT_SYMBOL_IF_KUNIT(aa_unpack_strdup); 400 401 402 /** 403 * unpack_dfa - unpack a file rule dfa 404 * @e: serialized data extent information (NOT NULL) 405 * @flags: dfa flags to check 406 * 407 * returns dfa or ERR_PTR or NULL if no dfa 408 */ 409 static struct aa_dfa *unpack_dfa(struct aa_ext *e, int flags) 410 { 411 char *blob = NULL; 412 size_t size; 413 struct aa_dfa *dfa = NULL; 414 415 size = aa_unpack_blob(e, &blob, "aadfa"); 416 if (size) { 417 /* 418 * The dfa is aligned with in the blob to 8 bytes 419 * from the beginning of the stream. 420 * alignment adjust needed by dfa unpack 421 */ 422 size_t sz = blob - (char *) e->start - 423 ((e->pos - e->start) & 7); 424 size_t pad = ALIGN(sz, 8) - sz; 425 if (aa_g_paranoid_load) 426 flags |= DFA_FLAG_VERIFY_STATES; 427 dfa = aa_dfa_unpack(blob + pad, size - pad, flags); 428 429 if (IS_ERR(dfa)) 430 return dfa; 431 432 } 433 434 return dfa; 435 } 436 437 /** 438 * unpack_trans_table - unpack a profile transition table 439 * @e: serialized data extent information (NOT NULL) 440 * @table: str table to unpack to (NOT NULL) 441 * 442 * Returns: true if table successfully unpacked or not present 443 */ 444 static bool unpack_trans_table(struct aa_ext *e, struct aa_str_table *strs) 445 { 446 void *saved_pos = e->pos; 447 char **table = NULL; 448 449 /* exec table is optional */ 450 if (aa_unpack_nameX(e, AA_STRUCT, "xtable")) { 451 u16 size; 452 int i; 453 454 if (!aa_unpack_array(e, NULL, &size)) 455 /* 456 * Note: index into trans table array is a max 457 * of 2^24, but unpack array can only unpack 458 * an array of 2^16 in size atm so no need 459 * for size check here 460 */ 461 goto fail; 462 table = kcalloc(size, sizeof(char *), GFP_KERNEL); 463 if (!table) 464 goto fail; 465 466 for (i = 0; i < size; i++) { 467 char *str; 468 int c, j, pos, size2 = aa_unpack_strdup(e, &str, NULL); 469 /* aa_unpack_strdup verifies that the last character is 470 * null termination byte. 471 */ 472 if (!size2) 473 goto fail; 474 table[i] = str; 475 /* verify that name doesn't start with space */ 476 if (isspace(*str)) 477 goto fail; 478 479 /* count internal # of internal \0 */ 480 for (c = j = 0; j < size2 - 1; j++) { 481 if (!str[j]) { 482 pos = j; 483 c++; 484 } 485 } 486 if (*str == ':') { 487 /* first character after : must be valid */ 488 if (!str[1]) 489 goto fail; 490 /* beginning with : requires an embedded \0, 491 * verify that exactly 1 internal \0 exists 492 * trailing \0 already verified by aa_unpack_strdup 493 * 494 * convert \0 back to : for label_parse 495 */ 496 if (c == 1) 497 str[pos] = ':'; 498 else if (c > 1) 499 goto fail; 500 } else if (c) 501 /* fail - all other cases with embedded \0 */ 502 goto fail; 503 } 504 if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) 505 goto fail; 506 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 507 goto fail; 508 509 strs->table = table; 510 strs->size = size; 511 } 512 return true; 513 514 fail: 515 kfree_sensitive(table); 516 e->pos = saved_pos; 517 return false; 518 } 519 520 static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile) 521 { 522 void *pos = e->pos; 523 524 if (aa_unpack_nameX(e, AA_STRUCT, "xattrs")) { 525 u16 size; 526 int i; 527 528 if (!aa_unpack_array(e, NULL, &size)) 529 goto fail; 530 profile->attach.xattr_count = size; 531 profile->attach.xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL); 532 if (!profile->attach.xattrs) 533 goto fail; 534 for (i = 0; i < size; i++) { 535 if (!aa_unpack_strdup(e, &profile->attach.xattrs[i], NULL)) 536 goto fail; 537 } 538 if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) 539 goto fail; 540 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 541 goto fail; 542 } 543 544 return true; 545 546 fail: 547 e->pos = pos; 548 return false; 549 } 550 551 static bool unpack_secmark(struct aa_ext *e, struct aa_ruleset *rules) 552 { 553 void *pos = e->pos; 554 u16 size; 555 int i; 556 557 if (aa_unpack_nameX(e, AA_STRUCT, "secmark")) { 558 if (!aa_unpack_array(e, NULL, &size)) 559 goto fail; 560 561 rules->secmark = kcalloc(size, sizeof(struct aa_secmark), 562 GFP_KERNEL); 563 if (!rules->secmark) 564 goto fail; 565 566 rules->secmark_count = size; 567 568 for (i = 0; i < size; i++) { 569 if (!unpack_u8(e, &rules->secmark[i].audit, NULL)) 570 goto fail; 571 if (!unpack_u8(e, &rules->secmark[i].deny, NULL)) 572 goto fail; 573 if (!aa_unpack_strdup(e, &rules->secmark[i].label, NULL)) 574 goto fail; 575 } 576 if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) 577 goto fail; 578 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 579 goto fail; 580 } 581 582 return true; 583 584 fail: 585 if (rules->secmark) { 586 for (i = 0; i < size; i++) 587 kfree(rules->secmark[i].label); 588 kfree(rules->secmark); 589 rules->secmark_count = 0; 590 rules->secmark = NULL; 591 } 592 593 e->pos = pos; 594 return false; 595 } 596 597 static bool unpack_rlimits(struct aa_ext *e, struct aa_ruleset *rules) 598 { 599 void *pos = e->pos; 600 601 /* rlimits are optional */ 602 if (aa_unpack_nameX(e, AA_STRUCT, "rlimits")) { 603 u16 size; 604 int i; 605 u32 tmp = 0; 606 if (!aa_unpack_u32(e, &tmp, NULL)) 607 goto fail; 608 rules->rlimits.mask = tmp; 609 610 if (!aa_unpack_array(e, NULL, &size) || 611 size > RLIM_NLIMITS) 612 goto fail; 613 for (i = 0; i < size; i++) { 614 u64 tmp2 = 0; 615 int a = aa_map_resource(i); 616 if (!aa_unpack_u64(e, &tmp2, NULL)) 617 goto fail; 618 rules->rlimits.limits[a].rlim_max = tmp2; 619 } 620 if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) 621 goto fail; 622 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 623 goto fail; 624 } 625 return true; 626 627 fail: 628 e->pos = pos; 629 return false; 630 } 631 632 static bool unpack_perm(struct aa_ext *e, u32 version, struct aa_perms *perm) 633 { 634 if (version != 1) 635 return false; 636 637 return aa_unpack_u32(e, &perm->allow, NULL) && 638 aa_unpack_u32(e, &perm->allow, NULL) && 639 aa_unpack_u32(e, &perm->deny, NULL) && 640 aa_unpack_u32(e, &perm->subtree, NULL) && 641 aa_unpack_u32(e, &perm->cond, NULL) && 642 aa_unpack_u32(e, &perm->kill, NULL) && 643 aa_unpack_u32(e, &perm->complain, NULL) && 644 aa_unpack_u32(e, &perm->prompt, NULL) && 645 aa_unpack_u32(e, &perm->audit, NULL) && 646 aa_unpack_u32(e, &perm->quiet, NULL) && 647 aa_unpack_u32(e, &perm->hide, NULL) && 648 aa_unpack_u32(e, &perm->xindex, NULL) && 649 aa_unpack_u32(e, &perm->tag, NULL) && 650 aa_unpack_u32(e, &perm->label, NULL); 651 } 652 653 static ssize_t unpack_perms_table(struct aa_ext *e, struct aa_perms **perms) 654 { 655 void *pos = e->pos; 656 u16 size = 0; 657 658 AA_BUG(!perms); 659 /* 660 * policy perms are optional, in which case perms are embedded 661 * in the dfa accept table 662 */ 663 if (aa_unpack_nameX(e, AA_STRUCT, "perms")) { 664 int i; 665 u32 version; 666 667 if (!aa_unpack_u32(e, &version, "version")) 668 goto fail_reset; 669 if (!aa_unpack_array(e, NULL, &size)) 670 goto fail_reset; 671 *perms = kcalloc(size, sizeof(struct aa_perms), GFP_KERNEL); 672 if (!*perms) 673 goto fail_reset; 674 for (i = 0; i < size; i++) { 675 if (!unpack_perm(e, version, &(*perms)[i])) 676 goto fail; 677 } 678 if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) 679 goto fail; 680 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 681 goto fail; 682 } else 683 *perms = NULL; 684 685 return size; 686 687 fail: 688 kfree(*perms); 689 fail_reset: 690 e->pos = pos; 691 return -EPROTO; 692 } 693 694 static int unpack_pdb(struct aa_ext *e, struct aa_policydb *policy, 695 bool required_dfa, bool required_trans, 696 const char **info) 697 { 698 void *pos = e->pos; 699 int i, flags, error = -EPROTO; 700 ssize_t size; 701 702 size = unpack_perms_table(e, &policy->perms); 703 if (size < 0) { 704 error = size; 705 policy->perms = NULL; 706 *info = "failed to unpack - perms"; 707 goto fail; 708 } 709 policy->size = size; 710 711 if (policy->perms) { 712 /* perms table present accept is index */ 713 flags = TO_ACCEPT1_FLAG(YYTD_DATA32); 714 } else { 715 /* packed perms in accept1 and accept2 */ 716 flags = TO_ACCEPT1_FLAG(YYTD_DATA32) | 717 TO_ACCEPT2_FLAG(YYTD_DATA32); 718 } 719 720 policy->dfa = unpack_dfa(e, flags); 721 if (IS_ERR(policy->dfa)) { 722 error = PTR_ERR(policy->dfa); 723 policy->dfa = NULL; 724 *info = "failed to unpack - dfa"; 725 goto fail; 726 } else if (!policy->dfa) { 727 if (required_dfa) { 728 *info = "missing required dfa"; 729 goto fail; 730 } 731 goto out; 732 } 733 734 /* 735 * only unpack the following if a dfa is present 736 * 737 * sadly start was given different names for file and policydb 738 * but since it is optional we can try both 739 */ 740 if (!aa_unpack_u32(e, &policy->start[0], "start")) 741 /* default start state */ 742 policy->start[0] = DFA_START; 743 if (!aa_unpack_u32(e, &policy->start[AA_CLASS_FILE], "dfa_start")) { 744 /* default start state for xmatch and file dfa */ 745 policy->start[AA_CLASS_FILE] = DFA_START; 746 } /* setup class index */ 747 for (i = AA_CLASS_FILE + 1; i <= AA_CLASS_LAST; i++) { 748 policy->start[i] = aa_dfa_next(policy->dfa, policy->start[0], 749 i); 750 } 751 if (!unpack_trans_table(e, &policy->trans) && required_trans) { 752 *info = "failed to unpack profile transition table"; 753 goto fail; 754 } 755 756 /* TODO: move compat mapping here, requires dfa merging first */ 757 /* TODO: move verify here, it has to be done after compat mappings */ 758 out: 759 return 0; 760 761 fail: 762 e->pos = pos; 763 return error; 764 } 765 766 static u32 strhash(const void *data, u32 len, u32 seed) 767 { 768 const char * const *key = data; 769 770 return jhash(*key, strlen(*key), seed); 771 } 772 773 static int datacmp(struct rhashtable_compare_arg *arg, const void *obj) 774 { 775 const struct aa_data *data = obj; 776 const char * const *key = arg->key; 777 778 return strcmp(data->key, *key); 779 } 780 781 /** 782 * unpack_profile - unpack a serialized profile 783 * @e: serialized data extent information (NOT NULL) 784 * @ns_name: pointer of newly allocated copy of %NULL in case of error 785 * 786 * NOTE: unpack profile sets audit struct if there is a failure 787 */ 788 static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name) 789 { 790 struct aa_ruleset *rules; 791 struct aa_profile *profile = NULL; 792 const char *tmpname, *tmpns = NULL, *name = NULL; 793 const char *info = "failed to unpack profile"; 794 size_t ns_len; 795 struct rhashtable_params params = { 0 }; 796 char *key = NULL; 797 struct aa_data *data; 798 int error = -EPROTO; 799 kernel_cap_t tmpcap; 800 u32 tmp; 801 802 *ns_name = NULL; 803 804 /* check that we have the right struct being passed */ 805 if (!aa_unpack_nameX(e, AA_STRUCT, "profile")) 806 goto fail; 807 if (!aa_unpack_str(e, &name, NULL)) 808 goto fail; 809 if (*name == '\0') 810 goto fail; 811 812 tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len); 813 if (tmpns) { 814 *ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL); 815 if (!*ns_name) { 816 info = "out of memory"; 817 error = -ENOMEM; 818 goto fail; 819 } 820 name = tmpname; 821 } 822 823 profile = aa_alloc_profile(name, NULL, GFP_KERNEL); 824 if (!profile) { 825 info = "out of memory"; 826 error = -ENOMEM; 827 goto fail; 828 } 829 rules = list_first_entry(&profile->rules, typeof(*rules), list); 830 831 /* profile renaming is optional */ 832 (void) aa_unpack_str(e, &profile->rename, "rename"); 833 834 /* attachment string is optional */ 835 (void) aa_unpack_str(e, &profile->attach.xmatch_str, "attach"); 836 837 /* xmatch is optional and may be NULL */ 838 error = unpack_pdb(e, &profile->attach.xmatch, false, false, &info); 839 if (error) { 840 info = "bad xmatch"; 841 goto fail; 842 } 843 844 /* neither xmatch_len not xmatch_perms are optional if xmatch is set */ 845 if (profile->attach.xmatch.dfa) { 846 if (!aa_unpack_u32(e, &tmp, NULL)) { 847 info = "missing xmatch len"; 848 goto fail; 849 } 850 profile->attach.xmatch_len = tmp; 851 profile->attach.xmatch.start[AA_CLASS_XMATCH] = DFA_START; 852 error = aa_compat_map_xmatch(&profile->attach.xmatch); 853 if (error) { 854 info = "failed to convert xmatch permission table"; 855 goto fail; 856 } 857 } 858 859 /* disconnected attachment string is optional */ 860 (void) aa_unpack_str(e, &profile->disconnected, "disconnected"); 861 862 /* per profile debug flags (complain, audit) */ 863 if (!aa_unpack_nameX(e, AA_STRUCT, "flags")) { 864 info = "profile missing flags"; 865 goto fail; 866 } 867 info = "failed to unpack profile flags"; 868 if (!aa_unpack_u32(e, &tmp, NULL)) 869 goto fail; 870 if (tmp & PACKED_FLAG_HAT) 871 profile->label.flags |= FLAG_HAT; 872 if (tmp & PACKED_FLAG_DEBUG1) 873 profile->label.flags |= FLAG_DEBUG1; 874 if (tmp & PACKED_FLAG_DEBUG2) 875 profile->label.flags |= FLAG_DEBUG2; 876 if (!aa_unpack_u32(e, &tmp, NULL)) 877 goto fail; 878 if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG)) { 879 profile->mode = APPARMOR_COMPLAIN; 880 } else if (tmp == PACKED_MODE_ENFORCE) { 881 profile->mode = APPARMOR_ENFORCE; 882 } else if (tmp == PACKED_MODE_KILL) { 883 profile->mode = APPARMOR_KILL; 884 } else if (tmp == PACKED_MODE_UNCONFINED) { 885 profile->mode = APPARMOR_UNCONFINED; 886 profile->label.flags |= FLAG_UNCONFINED; 887 } else if (tmp == PACKED_MODE_USER) { 888 profile->mode = APPARMOR_USER; 889 } else { 890 goto fail; 891 } 892 if (!aa_unpack_u32(e, &tmp, NULL)) 893 goto fail; 894 if (tmp) 895 profile->audit = AUDIT_ALL; 896 897 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 898 goto fail; 899 900 /* path_flags is optional */ 901 if (aa_unpack_u32(e, &profile->path_flags, "path_flags")) 902 profile->path_flags |= profile->label.flags & 903 PATH_MEDIATE_DELETED; 904 else 905 /* set a default value if path_flags field is not present */ 906 profile->path_flags = PATH_MEDIATE_DELETED; 907 908 info = "failed to unpack profile capabilities"; 909 if (!aa_unpack_u32(e, &(rules->caps.allow.cap[0]), NULL)) 910 goto fail; 911 if (!aa_unpack_u32(e, &(rules->caps.audit.cap[0]), NULL)) 912 goto fail; 913 if (!aa_unpack_u32(e, &(rules->caps.quiet.cap[0]), NULL)) 914 goto fail; 915 if (!aa_unpack_u32(e, &tmpcap.cap[0], NULL)) 916 goto fail; 917 918 info = "failed to unpack upper profile capabilities"; 919 if (aa_unpack_nameX(e, AA_STRUCT, "caps64")) { 920 /* optional upper half of 64 bit caps */ 921 if (!aa_unpack_u32(e, &(rules->caps.allow.cap[1]), NULL)) 922 goto fail; 923 if (!aa_unpack_u32(e, &(rules->caps.audit.cap[1]), NULL)) 924 goto fail; 925 if (!aa_unpack_u32(e, &(rules->caps.quiet.cap[1]), NULL)) 926 goto fail; 927 if (!aa_unpack_u32(e, &(tmpcap.cap[1]), NULL)) 928 goto fail; 929 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 930 goto fail; 931 } 932 933 info = "failed to unpack extended profile capabilities"; 934 if (aa_unpack_nameX(e, AA_STRUCT, "capsx")) { 935 /* optional extended caps mediation mask */ 936 if (!aa_unpack_u32(e, &(rules->caps.extended.cap[0]), NULL)) 937 goto fail; 938 if (!aa_unpack_u32(e, &(rules->caps.extended.cap[1]), NULL)) 939 goto fail; 940 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 941 goto fail; 942 } 943 944 if (!unpack_xattrs(e, profile)) { 945 info = "failed to unpack profile xattrs"; 946 goto fail; 947 } 948 949 if (!unpack_rlimits(e, rules)) { 950 info = "failed to unpack profile rlimits"; 951 goto fail; 952 } 953 954 if (!unpack_secmark(e, rules)) { 955 info = "failed to unpack profile secmark rules"; 956 goto fail; 957 } 958 959 if (aa_unpack_nameX(e, AA_STRUCT, "policydb")) { 960 /* generic policy dfa - optional and may be NULL */ 961 info = "failed to unpack policydb"; 962 error = unpack_pdb(e, &rules->policy, true, false, 963 &info); 964 if (error) 965 goto fail; 966 /* Fixup: drop when we get rid of start array */ 967 if (aa_dfa_next(rules->policy.dfa, rules->policy.start[0], 968 AA_CLASS_FILE)) 969 rules->policy.start[AA_CLASS_FILE] = 970 aa_dfa_next(rules->policy.dfa, 971 rules->policy.start[0], 972 AA_CLASS_FILE); 973 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) 974 goto fail; 975 error = aa_compat_map_policy(&rules->policy, e->version); 976 if (error) { 977 info = "failed to remap policydb permission table"; 978 goto fail; 979 } 980 } else 981 rules->policy.dfa = aa_get_dfa(nulldfa); 982 983 /* get file rules */ 984 error = unpack_pdb(e, &rules->file, false, true, &info); 985 if (error) { 986 goto fail; 987 } else if (rules->file.dfa) { 988 error = aa_compat_map_file(&rules->file); 989 if (error) { 990 info = "failed to remap file permission table"; 991 goto fail; 992 } 993 } else if (rules->policy.dfa && 994 rules->policy.start[AA_CLASS_FILE]) { 995 rules->file.dfa = aa_get_dfa(rules->policy.dfa); 996 rules->file.start[AA_CLASS_FILE] = rules->policy.start[AA_CLASS_FILE]; 997 } else 998 rules->file.dfa = aa_get_dfa(nulldfa); 999 1000 error = -EPROTO; 1001 if (aa_unpack_nameX(e, AA_STRUCT, "data")) { 1002 info = "out of memory"; 1003 profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL); 1004 if (!profile->data) { 1005 error = -ENOMEM; 1006 goto fail; 1007 } 1008 params.nelem_hint = 3; 1009 params.key_len = sizeof(void *); 1010 params.key_offset = offsetof(struct aa_data, key); 1011 params.head_offset = offsetof(struct aa_data, head); 1012 params.hashfn = strhash; 1013 params.obj_cmpfn = datacmp; 1014 1015 if (rhashtable_init(profile->data, ¶ms)) { 1016 info = "failed to init key, value hash table"; 1017 goto fail; 1018 } 1019 1020 while (aa_unpack_strdup(e, &key, NULL)) { 1021 data = kzalloc(sizeof(*data), GFP_KERNEL); 1022 if (!data) { 1023 kfree_sensitive(key); 1024 error = -ENOMEM; 1025 goto fail; 1026 } 1027 1028 data->key = key; 1029 data->size = aa_unpack_blob(e, &data->data, NULL); 1030 data->data = kvmemdup(data->data, data->size); 1031 if (data->size && !data->data) { 1032 kfree_sensitive(data->key); 1033 kfree_sensitive(data); 1034 error = -ENOMEM; 1035 goto fail; 1036 } 1037 1038 rhashtable_insert_fast(profile->data, &data->head, 1039 profile->data->p); 1040 } 1041 1042 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) { 1043 info = "failed to unpack end of key, value data table"; 1044 goto fail; 1045 } 1046 } 1047 1048 if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) { 1049 info = "failed to unpack end of profile"; 1050 goto fail; 1051 } 1052 1053 return profile; 1054 1055 fail: 1056 if (error == 0) 1057 /* default error covers most cases */ 1058 error = -EPROTO; 1059 if (*ns_name) { 1060 kfree(*ns_name); 1061 *ns_name = NULL; 1062 } 1063 if (profile) 1064 name = NULL; 1065 else if (!name) 1066 name = "unknown"; 1067 audit_iface(profile, NULL, name, info, e, error); 1068 aa_free_profile(profile); 1069 1070 return ERR_PTR(error); 1071 } 1072 1073 /** 1074 * verify_header - unpack serialized stream header 1075 * @e: serialized data read head (NOT NULL) 1076 * @required: whether the header is required or optional 1077 * @ns: Returns - namespace if one is specified else NULL (NOT NULL) 1078 * 1079 * Returns: error or 0 if header is good 1080 */ 1081 static int verify_header(struct aa_ext *e, int required, const char **ns) 1082 { 1083 int error = -EPROTONOSUPPORT; 1084 const char *name = NULL; 1085 *ns = NULL; 1086 1087 /* get the interface version */ 1088 if (!aa_unpack_u32(e, &e->version, "version")) { 1089 if (required) { 1090 audit_iface(NULL, NULL, NULL, "invalid profile format", 1091 e, error); 1092 return error; 1093 } 1094 } 1095 1096 /* Check that the interface version is currently supported. 1097 * if not specified use previous version 1098 * Mask off everything that is not kernel abi version 1099 */ 1100 if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v9)) { 1101 audit_iface(NULL, NULL, NULL, "unsupported interface version", 1102 e, error); 1103 return error; 1104 } 1105 1106 /* read the namespace if present */ 1107 if (aa_unpack_str(e, &name, "namespace")) { 1108 if (*name == '\0') { 1109 audit_iface(NULL, NULL, NULL, "invalid namespace name", 1110 e, error); 1111 return error; 1112 } 1113 if (*ns && strcmp(*ns, name)) { 1114 audit_iface(NULL, NULL, NULL, "invalid ns change", e, 1115 error); 1116 } else if (!*ns) { 1117 *ns = kstrdup(name, GFP_KERNEL); 1118 if (!*ns) 1119 return -ENOMEM; 1120 } 1121 } 1122 1123 return 0; 1124 } 1125 1126 static bool verify_xindex(int xindex, int table_size) 1127 { 1128 int index, xtype; 1129 xtype = xindex & AA_X_TYPE_MASK; 1130 index = xindex & AA_X_INDEX_MASK; 1131 if (xtype == AA_X_TABLE && index >= table_size) 1132 return false; 1133 return true; 1134 } 1135 1136 /* verify dfa xindexes are in range of transition tables */ 1137 static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size) 1138 { 1139 int i; 1140 for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { 1141 if (!verify_xindex(ACCEPT_TABLE(dfa)[i], table_size)) 1142 return false; 1143 } 1144 return true; 1145 } 1146 1147 static bool verify_perm(struct aa_perms *perm) 1148 { 1149 /* TODO: allow option to just force the perms into a valid state */ 1150 if (perm->allow & perm->deny) 1151 return false; 1152 if (perm->subtree & ~perm->allow) 1153 return false; 1154 if (perm->cond & (perm->allow | perm->deny)) 1155 return false; 1156 if (perm->kill & perm->allow) 1157 return false; 1158 if (perm->complain & (perm->allow | perm->deny)) 1159 return false; 1160 if (perm->prompt & (perm->allow | perm->deny)) 1161 return false; 1162 if (perm->complain & perm->prompt) 1163 return false; 1164 if (perm->hide & perm->allow) 1165 return false; 1166 1167 return true; 1168 } 1169 1170 static bool verify_perms(struct aa_policydb *pdb) 1171 { 1172 int i; 1173 1174 for (i = 0; i < pdb->size; i++) { 1175 if (!verify_perm(&pdb->perms[i])) 1176 return false; 1177 /* verify indexes into str table */ 1178 if (pdb->perms[i].xindex >= pdb->trans.size) 1179 return false; 1180 if (pdb->perms[i].tag >= pdb->trans.size) 1181 return false; 1182 if (pdb->perms[i].label >= pdb->trans.size) 1183 return false; 1184 } 1185 1186 return true; 1187 } 1188 1189 /** 1190 * verify_profile - Do post unpack analysis to verify profile consistency 1191 * @profile: profile to verify (NOT NULL) 1192 * 1193 * Returns: 0 if passes verification else error 1194 * 1195 * This verification is post any unpack mapping or changes 1196 */ 1197 static int verify_profile(struct aa_profile *profile) 1198 { 1199 struct aa_ruleset *rules = list_first_entry(&profile->rules, 1200 typeof(*rules), list); 1201 if (!rules) 1202 return 0; 1203 1204 if ((rules->file.dfa && !verify_dfa_xindex(rules->file.dfa, 1205 rules->file.trans.size)) || 1206 (rules->policy.dfa && 1207 !verify_dfa_xindex(rules->policy.dfa, rules->policy.trans.size))) { 1208 audit_iface(profile, NULL, NULL, 1209 "Unpack: Invalid named transition", NULL, -EPROTO); 1210 return -EPROTO; 1211 } 1212 1213 if (!verify_perms(&rules->file)) { 1214 audit_iface(profile, NULL, NULL, 1215 "Unpack: Invalid perm index", NULL, -EPROTO); 1216 return -EPROTO; 1217 } 1218 if (!verify_perms(&rules->policy)) { 1219 audit_iface(profile, NULL, NULL, 1220 "Unpack: Invalid perm index", NULL, -EPROTO); 1221 return -EPROTO; 1222 } 1223 if (!verify_perms(&profile->attach.xmatch)) { 1224 audit_iface(profile, NULL, NULL, 1225 "Unpack: Invalid perm index", NULL, -EPROTO); 1226 return -EPROTO; 1227 } 1228 1229 return 0; 1230 } 1231 1232 void aa_load_ent_free(struct aa_load_ent *ent) 1233 { 1234 if (ent) { 1235 aa_put_profile(ent->rename); 1236 aa_put_profile(ent->old); 1237 aa_put_profile(ent->new); 1238 kfree(ent->ns_name); 1239 kfree_sensitive(ent); 1240 } 1241 } 1242 1243 struct aa_load_ent *aa_load_ent_alloc(void) 1244 { 1245 struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL); 1246 if (ent) 1247 INIT_LIST_HEAD(&ent->list); 1248 return ent; 1249 } 1250 1251 static int compress_zstd(const char *src, size_t slen, char **dst, size_t *dlen) 1252 { 1253 #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY 1254 const zstd_parameters params = 1255 zstd_get_params(aa_g_rawdata_compression_level, slen); 1256 const size_t wksp_len = zstd_cctx_workspace_bound(¶ms.cParams); 1257 void *wksp = NULL; 1258 zstd_cctx *ctx = NULL; 1259 size_t out_len = zstd_compress_bound(slen); 1260 void *out = NULL; 1261 int ret = 0; 1262 1263 out = kvzalloc(out_len, GFP_KERNEL); 1264 if (!out) { 1265 ret = -ENOMEM; 1266 goto cleanup; 1267 } 1268 1269 wksp = kvzalloc(wksp_len, GFP_KERNEL); 1270 if (!wksp) { 1271 ret = -ENOMEM; 1272 goto cleanup; 1273 } 1274 1275 ctx = zstd_init_cctx(wksp, wksp_len); 1276 if (!ctx) { 1277 ret = -EINVAL; 1278 goto cleanup; 1279 } 1280 1281 out_len = zstd_compress_cctx(ctx, out, out_len, src, slen, ¶ms); 1282 if (zstd_is_error(out_len) || out_len >= slen) { 1283 ret = -EINVAL; 1284 goto cleanup; 1285 } 1286 1287 if (is_vmalloc_addr(out)) { 1288 *dst = kvzalloc(out_len, GFP_KERNEL); 1289 if (*dst) { 1290 memcpy(*dst, out, out_len); 1291 kvfree(out); 1292 out = NULL; 1293 } 1294 } else { 1295 /* 1296 * If the staging buffer was kmalloc'd, then using krealloc is 1297 * probably going to be faster. The destination buffer will 1298 * always be smaller, so it's just shrunk, avoiding a memcpy 1299 */ 1300 *dst = krealloc(out, out_len, GFP_KERNEL); 1301 } 1302 1303 if (!*dst) { 1304 ret = -ENOMEM; 1305 goto cleanup; 1306 } 1307 1308 *dlen = out_len; 1309 1310 cleanup: 1311 if (ret) { 1312 kvfree(out); 1313 *dst = NULL; 1314 } 1315 1316 kvfree(wksp); 1317 return ret; 1318 #else 1319 *dlen = slen; 1320 return 0; 1321 #endif 1322 } 1323 1324 static int compress_loaddata(struct aa_loaddata *data) 1325 { 1326 AA_BUG(data->compressed_size > 0); 1327 1328 /* 1329 * Shortcut the no compression case, else we increase the amount of 1330 * storage required by a small amount 1331 */ 1332 if (aa_g_rawdata_compression_level != 0) { 1333 void *udata = data->data; 1334 int error = compress_zstd(udata, data->size, &data->data, 1335 &data->compressed_size); 1336 if (error) { 1337 data->compressed_size = data->size; 1338 return error; 1339 } 1340 if (udata != data->data) 1341 kvfree(udata); 1342 } else 1343 data->compressed_size = data->size; 1344 1345 return 0; 1346 } 1347 1348 /** 1349 * aa_unpack - unpack packed binary profile(s) data loaded from user space 1350 * @udata: user data copied to kmem (NOT NULL) 1351 * @lh: list to place unpacked profiles in a aa_repl_ws 1352 * @ns: Returns namespace profile is in if specified else NULL (NOT NULL) 1353 * 1354 * Unpack user data and return refcounted allocated profile(s) stored in 1355 * @lh in order of discovery, with the list chain stored in base.list 1356 * or error 1357 * 1358 * Returns: profile(s) on @lh else error pointer if fails to unpack 1359 */ 1360 int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, 1361 const char **ns) 1362 { 1363 struct aa_load_ent *tmp, *ent; 1364 struct aa_profile *profile = NULL; 1365 char *ns_name = NULL; 1366 int error; 1367 struct aa_ext e = { 1368 .start = udata->data, 1369 .end = udata->data + udata->size, 1370 .pos = udata->data, 1371 }; 1372 1373 *ns = NULL; 1374 while (e.pos < e.end) { 1375 void *start; 1376 error = verify_header(&e, e.pos == e.start, ns); 1377 if (error) 1378 goto fail; 1379 1380 start = e.pos; 1381 profile = unpack_profile(&e, &ns_name); 1382 if (IS_ERR(profile)) { 1383 error = PTR_ERR(profile); 1384 goto fail; 1385 } 1386 1387 error = verify_profile(profile); 1388 if (error) 1389 goto fail_profile; 1390 1391 if (aa_g_hash_policy) 1392 error = aa_calc_profile_hash(profile, e.version, start, 1393 e.pos - start); 1394 if (error) 1395 goto fail_profile; 1396 1397 ent = aa_load_ent_alloc(); 1398 if (!ent) { 1399 error = -ENOMEM; 1400 goto fail_profile; 1401 } 1402 1403 ent->new = profile; 1404 ent->ns_name = ns_name; 1405 ns_name = NULL; 1406 list_add_tail(&ent->list, lh); 1407 } 1408 udata->abi = e.version & K_ABI_MASK; 1409 if (aa_g_hash_policy) { 1410 udata->hash = aa_calc_hash(udata->data, udata->size); 1411 if (IS_ERR(udata->hash)) { 1412 error = PTR_ERR(udata->hash); 1413 udata->hash = NULL; 1414 goto fail; 1415 } 1416 } 1417 1418 if (aa_g_export_binary) { 1419 error = compress_loaddata(udata); 1420 if (error) 1421 goto fail; 1422 } 1423 return 0; 1424 1425 fail_profile: 1426 kfree(ns_name); 1427 aa_put_profile(profile); 1428 1429 fail: 1430 list_for_each_entry_safe(ent, tmp, lh, list) { 1431 list_del_init(&ent->list); 1432 aa_load_ent_free(ent); 1433 } 1434 1435 return error; 1436 } 1437