1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Implementation of the security services. 4 * 5 * Authors : Stephen Smalley, <stephen.smalley.work@gmail.com> 6 * James Morris <jmorris@redhat.com> 7 * 8 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> 9 * 10 * Support for enhanced MLS infrastructure. 11 * Support for context based audit filters. 12 * 13 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> 14 * 15 * Added conditional policy language extensions 16 * 17 * Updated: Hewlett-Packard <paul@paul-moore.com> 18 * 19 * Added support for NetLabel 20 * Added support for the policy capability bitmap 21 * 22 * Updated: Chad Sellers <csellers@tresys.com> 23 * 24 * Added validation of kernel classes and permissions 25 * 26 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> 27 * 28 * Added support for bounds domain and audit messaged on masked permissions 29 * 30 * Updated: Guido Trentalancia <guido@trentalancia.com> 31 * 32 * Added support for runtime switching of the policy type 33 * 34 * Copyright (C) 2008, 2009 NEC Corporation 35 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. 36 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. 37 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC 38 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> 39 */ 40 #include <linux/kernel.h> 41 #include <linux/slab.h> 42 #include <linux/string.h> 43 #include <linux/spinlock.h> 44 #include <linux/rcupdate.h> 45 #include <linux/errno.h> 46 #include <linux/in.h> 47 #include <linux/sched.h> 48 #include <linux/audit.h> 49 #include <linux/vmalloc.h> 50 #include <linux/lsm_hooks.h> 51 #include <net/netlabel.h> 52 53 #include "flask.h" 54 #include "avc.h" 55 #include "avc_ss.h" 56 #include "security.h" 57 #include "context.h" 58 #include "policydb.h" 59 #include "sidtab.h" 60 #include "services.h" 61 #include "conditional.h" 62 #include "mls.h" 63 #include "objsec.h" 64 #include "netlabel.h" 65 #include "xfrm.h" 66 #include "ebitmap.h" 67 #include "audit.h" 68 #include "policycap_names.h" 69 #include "ima.h" 70 71 struct selinux_policy_convert_data { 72 struct convert_context_args args; 73 struct sidtab_convert_params sidtab_params; 74 }; 75 76 /* Forward declaration. */ 77 static int context_struct_to_string(struct policydb *policydb, 78 struct context *context, 79 char **scontext, 80 u32 *scontext_len); 81 82 static int sidtab_entry_to_string(struct policydb *policydb, 83 struct sidtab *sidtab, 84 struct sidtab_entry *entry, 85 char **scontext, 86 u32 *scontext_len); 87 88 static void context_struct_compute_av(struct policydb *policydb, 89 struct context *scontext, 90 struct context *tcontext, 91 u16 tclass, 92 struct av_decision *avd, 93 struct extended_perms *xperms); 94 95 static int selinux_set_mapping(struct policydb *pol, 96 const struct security_class_mapping *map, 97 struct selinux_map *out_map) 98 { 99 u16 i, j; 100 bool print_unknown_handle = false; 101 102 /* Find number of classes in the input mapping */ 103 if (!map) 104 return -EINVAL; 105 i = 0; 106 while (map[i].name) 107 i++; 108 109 /* Allocate space for the class records, plus one for class zero */ 110 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 111 if (!out_map->mapping) 112 return -ENOMEM; 113 114 /* Store the raw class and permission values */ 115 j = 0; 116 while (map[j].name) { 117 const struct security_class_mapping *p_in = map + (j++); 118 struct selinux_mapping *p_out = out_map->mapping + j; 119 u16 k; 120 121 /* An empty class string skips ahead */ 122 if (!strcmp(p_in->name, "")) { 123 p_out->num_perms = 0; 124 continue; 125 } 126 127 p_out->value = string_to_security_class(pol, p_in->name); 128 if (!p_out->value) { 129 pr_info("SELinux: Class %s not defined in policy.\n", 130 p_in->name); 131 if (pol->reject_unknown) 132 goto err; 133 p_out->num_perms = 0; 134 print_unknown_handle = true; 135 continue; 136 } 137 138 k = 0; 139 while (p_in->perms[k]) { 140 /* An empty permission string skips ahead */ 141 if (!*p_in->perms[k]) { 142 k++; 143 continue; 144 } 145 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 146 p_in->perms[k]); 147 if (!p_out->perms[k]) { 148 pr_info("SELinux: Permission %s in class %s not defined in policy.\n", 149 p_in->perms[k], p_in->name); 150 if (pol->reject_unknown) 151 goto err; 152 print_unknown_handle = true; 153 } 154 155 k++; 156 } 157 p_out->num_perms = k; 158 } 159 160 if (print_unknown_handle) 161 pr_info("SELinux: the above unknown classes and permissions will be %s\n", 162 pol->allow_unknown ? "allowed" : "denied"); 163 164 out_map->size = i; 165 return 0; 166 err: 167 kfree(out_map->mapping); 168 out_map->mapping = NULL; 169 return -EINVAL; 170 } 171 172 /* 173 * Get real, policy values from mapped values 174 */ 175 176 static u16 unmap_class(struct selinux_map *map, u16 tclass) 177 { 178 if (tclass < map->size) 179 return map->mapping[tclass].value; 180 181 return tclass; 182 } 183 184 /* 185 * Get kernel value for class from its policy value 186 */ 187 static u16 map_class(struct selinux_map *map, u16 pol_value) 188 { 189 u16 i; 190 191 for (i = 1; i < map->size; i++) { 192 if (map->mapping[i].value == pol_value) 193 return i; 194 } 195 196 return SECCLASS_NULL; 197 } 198 199 static void map_decision(struct selinux_map *map, 200 u16 tclass, struct av_decision *avd, 201 int allow_unknown) 202 { 203 if (tclass < map->size) { 204 struct selinux_mapping *mapping = &map->mapping[tclass]; 205 unsigned int i, n = mapping->num_perms; 206 u32 result; 207 208 for (i = 0, result = 0; i < n; i++) { 209 if (avd->allowed & mapping->perms[i]) 210 result |= (u32)1<<i; 211 if (allow_unknown && !mapping->perms[i]) 212 result |= (u32)1<<i; 213 } 214 avd->allowed = result; 215 216 for (i = 0, result = 0; i < n; i++) 217 if (avd->auditallow & mapping->perms[i]) 218 result |= (u32)1<<i; 219 avd->auditallow = result; 220 221 for (i = 0, result = 0; i < n; i++) { 222 if (avd->auditdeny & mapping->perms[i]) 223 result |= (u32)1<<i; 224 if (!allow_unknown && !mapping->perms[i]) 225 result |= (u32)1<<i; 226 } 227 /* 228 * In case the kernel has a bug and requests a permission 229 * between num_perms and the maximum permission number, we 230 * should audit that denial 231 */ 232 for (; i < (sizeof(u32)*8); i++) 233 result |= (u32)1<<i; 234 avd->auditdeny = result; 235 } 236 } 237 238 int security_mls_enabled(void) 239 { 240 int mls_enabled; 241 struct selinux_policy *policy; 242 243 if (!selinux_initialized()) 244 return 0; 245 246 rcu_read_lock(); 247 policy = rcu_dereference(selinux_state.policy); 248 mls_enabled = policy->policydb.mls_enabled; 249 rcu_read_unlock(); 250 return mls_enabled; 251 } 252 253 /* 254 * Return the boolean value of a constraint expression 255 * when it is applied to the specified source and target 256 * security contexts. 257 * 258 * xcontext is a special beast... It is used by the validatetrans rules 259 * only. For these rules, scontext is the context before the transition, 260 * tcontext is the context after the transition, and xcontext is the context 261 * of the process performing the transition. All other callers of 262 * constraint_expr_eval should pass in NULL for xcontext. 263 */ 264 static int constraint_expr_eval(struct policydb *policydb, 265 struct context *scontext, 266 struct context *tcontext, 267 struct context *xcontext, 268 struct constraint_expr *cexpr) 269 { 270 u32 val1, val2; 271 struct context *c; 272 struct role_datum *r1, *r2; 273 struct mls_level *l1, *l2; 274 struct constraint_expr *e; 275 int s[CEXPR_MAXDEPTH]; 276 int sp = -1; 277 278 for (e = cexpr; e; e = e->next) { 279 switch (e->expr_type) { 280 case CEXPR_NOT: 281 BUG_ON(sp < 0); 282 s[sp] = !s[sp]; 283 break; 284 case CEXPR_AND: 285 BUG_ON(sp < 1); 286 sp--; 287 s[sp] &= s[sp + 1]; 288 break; 289 case CEXPR_OR: 290 BUG_ON(sp < 1); 291 sp--; 292 s[sp] |= s[sp + 1]; 293 break; 294 case CEXPR_ATTR: 295 if (sp == (CEXPR_MAXDEPTH - 1)) 296 return 0; 297 switch (e->attr) { 298 case CEXPR_USER: 299 val1 = scontext->user; 300 val2 = tcontext->user; 301 break; 302 case CEXPR_TYPE: 303 val1 = scontext->type; 304 val2 = tcontext->type; 305 break; 306 case CEXPR_ROLE: 307 val1 = scontext->role; 308 val2 = tcontext->role; 309 r1 = policydb->role_val_to_struct[val1 - 1]; 310 r2 = policydb->role_val_to_struct[val2 - 1]; 311 switch (e->op) { 312 case CEXPR_DOM: 313 s[++sp] = ebitmap_get_bit(&r1->dominates, 314 val2 - 1); 315 continue; 316 case CEXPR_DOMBY: 317 s[++sp] = ebitmap_get_bit(&r2->dominates, 318 val1 - 1); 319 continue; 320 case CEXPR_INCOMP: 321 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 322 val2 - 1) && 323 !ebitmap_get_bit(&r2->dominates, 324 val1 - 1)); 325 continue; 326 default: 327 break; 328 } 329 break; 330 case CEXPR_L1L2: 331 l1 = &(scontext->range.level[0]); 332 l2 = &(tcontext->range.level[0]); 333 goto mls_ops; 334 case CEXPR_L1H2: 335 l1 = &(scontext->range.level[0]); 336 l2 = &(tcontext->range.level[1]); 337 goto mls_ops; 338 case CEXPR_H1L2: 339 l1 = &(scontext->range.level[1]); 340 l2 = &(tcontext->range.level[0]); 341 goto mls_ops; 342 case CEXPR_H1H2: 343 l1 = &(scontext->range.level[1]); 344 l2 = &(tcontext->range.level[1]); 345 goto mls_ops; 346 case CEXPR_L1H1: 347 l1 = &(scontext->range.level[0]); 348 l2 = &(scontext->range.level[1]); 349 goto mls_ops; 350 case CEXPR_L2H2: 351 l1 = &(tcontext->range.level[0]); 352 l2 = &(tcontext->range.level[1]); 353 goto mls_ops; 354 mls_ops: 355 switch (e->op) { 356 case CEXPR_EQ: 357 s[++sp] = mls_level_eq(l1, l2); 358 continue; 359 case CEXPR_NEQ: 360 s[++sp] = !mls_level_eq(l1, l2); 361 continue; 362 case CEXPR_DOM: 363 s[++sp] = mls_level_dom(l1, l2); 364 continue; 365 case CEXPR_DOMBY: 366 s[++sp] = mls_level_dom(l2, l1); 367 continue; 368 case CEXPR_INCOMP: 369 s[++sp] = mls_level_incomp(l2, l1); 370 continue; 371 default: 372 BUG(); 373 return 0; 374 } 375 break; 376 default: 377 BUG(); 378 return 0; 379 } 380 381 switch (e->op) { 382 case CEXPR_EQ: 383 s[++sp] = (val1 == val2); 384 break; 385 case CEXPR_NEQ: 386 s[++sp] = (val1 != val2); 387 break; 388 default: 389 BUG(); 390 return 0; 391 } 392 break; 393 case CEXPR_NAMES: 394 if (sp == (CEXPR_MAXDEPTH-1)) 395 return 0; 396 c = scontext; 397 if (e->attr & CEXPR_TARGET) 398 c = tcontext; 399 else if (e->attr & CEXPR_XTARGET) { 400 c = xcontext; 401 if (!c) { 402 BUG(); 403 return 0; 404 } 405 } 406 if (e->attr & CEXPR_USER) 407 val1 = c->user; 408 else if (e->attr & CEXPR_ROLE) 409 val1 = c->role; 410 else if (e->attr & CEXPR_TYPE) 411 val1 = c->type; 412 else { 413 BUG(); 414 return 0; 415 } 416 417 switch (e->op) { 418 case CEXPR_EQ: 419 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 420 break; 421 case CEXPR_NEQ: 422 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 423 break; 424 default: 425 BUG(); 426 return 0; 427 } 428 break; 429 default: 430 BUG(); 431 return 0; 432 } 433 } 434 435 BUG_ON(sp != 0); 436 return s[0]; 437 } 438 439 /* 440 * security_dump_masked_av - dumps masked permissions during 441 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 442 */ 443 static int dump_masked_av_helper(void *k, void *d, void *args) 444 { 445 struct perm_datum *pdatum = d; 446 char **permission_names = args; 447 448 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 449 450 permission_names[pdatum->value - 1] = (char *)k; 451 452 return 0; 453 } 454 455 static void security_dump_masked_av(struct policydb *policydb, 456 struct context *scontext, 457 struct context *tcontext, 458 u16 tclass, 459 u32 permissions, 460 const char *reason) 461 { 462 struct common_datum *common_dat; 463 struct class_datum *tclass_dat; 464 struct audit_buffer *ab; 465 char *tclass_name; 466 char *scontext_name = NULL; 467 char *tcontext_name = NULL; 468 char *permission_names[32]; 469 int index; 470 u32 length; 471 bool need_comma = false; 472 473 if (!permissions) 474 return; 475 476 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); 477 tclass_dat = policydb->class_val_to_struct[tclass - 1]; 478 common_dat = tclass_dat->comdatum; 479 480 /* init permission_names */ 481 if (common_dat && 482 hashtab_map(&common_dat->permissions.table, 483 dump_masked_av_helper, permission_names) < 0) 484 goto out; 485 486 if (hashtab_map(&tclass_dat->permissions.table, 487 dump_masked_av_helper, permission_names) < 0) 488 goto out; 489 490 /* get scontext/tcontext in text form */ 491 if (context_struct_to_string(policydb, scontext, 492 &scontext_name, &length) < 0) 493 goto out; 494 495 if (context_struct_to_string(policydb, tcontext, 496 &tcontext_name, &length) < 0) 497 goto out; 498 499 /* audit a message */ 500 ab = audit_log_start(audit_context(), 501 GFP_ATOMIC, AUDIT_SELINUX_ERR); 502 if (!ab) 503 goto out; 504 505 audit_log_format(ab, "op=security_compute_av reason=%s " 506 "scontext=%s tcontext=%s tclass=%s perms=", 507 reason, scontext_name, tcontext_name, tclass_name); 508 509 for (index = 0; index < 32; index++) { 510 u32 mask = (1 << index); 511 512 if ((mask & permissions) == 0) 513 continue; 514 515 audit_log_format(ab, "%s%s", 516 need_comma ? "," : "", 517 permission_names[index] 518 ? permission_names[index] : "????"); 519 need_comma = true; 520 } 521 audit_log_end(ab); 522 out: 523 /* release scontext/tcontext */ 524 kfree(tcontext_name); 525 kfree(scontext_name); 526 } 527 528 /* 529 * security_boundary_permission - drops violated permissions 530 * on boundary constraint. 531 */ 532 static void type_attribute_bounds_av(struct policydb *policydb, 533 struct context *scontext, 534 struct context *tcontext, 535 u16 tclass, 536 struct av_decision *avd) 537 { 538 struct context lo_scontext; 539 struct context lo_tcontext, *tcontextp = tcontext; 540 struct av_decision lo_avd; 541 struct type_datum *source; 542 struct type_datum *target; 543 u32 masked = 0; 544 545 source = policydb->type_val_to_struct[scontext->type - 1]; 546 BUG_ON(!source); 547 548 if (!source->bounds) 549 return; 550 551 target = policydb->type_val_to_struct[tcontext->type - 1]; 552 BUG_ON(!target); 553 554 memset(&lo_avd, 0, sizeof(lo_avd)); 555 556 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 557 lo_scontext.type = source->bounds; 558 559 if (target->bounds) { 560 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 561 lo_tcontext.type = target->bounds; 562 tcontextp = &lo_tcontext; 563 } 564 565 context_struct_compute_av(policydb, &lo_scontext, 566 tcontextp, 567 tclass, 568 &lo_avd, 569 NULL); 570 571 masked = ~lo_avd.allowed & avd->allowed; 572 573 if (likely(!masked)) 574 return; /* no masked permission */ 575 576 /* mask violated permissions */ 577 avd->allowed &= ~masked; 578 579 /* audit masked permissions */ 580 security_dump_masked_av(policydb, scontext, tcontext, 581 tclass, masked, "bounds"); 582 } 583 584 /* 585 * Flag which drivers have permissions. 586 */ 587 void services_compute_xperms_drivers( 588 struct extended_perms *xperms, 589 struct avtab_node *node) 590 { 591 unsigned int i; 592 593 switch (node->datum.u.xperms->specified) { 594 case AVTAB_XPERMS_IOCTLDRIVER: 595 /* if one or more driver has all permissions allowed */ 596 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 597 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 598 break; 599 case AVTAB_XPERMS_IOCTLFUNCTION: 600 case AVTAB_XPERMS_NLMSG: 601 /* if allowing permissions within a driver */ 602 security_xperm_set(xperms->drivers.p, 603 node->datum.u.xperms->driver); 604 break; 605 } 606 607 xperms->len = 1; 608 } 609 610 /* 611 * Compute access vectors and extended permissions based on a context 612 * structure pair for the permissions in a particular class. 613 */ 614 static void context_struct_compute_av(struct policydb *policydb, 615 struct context *scontext, 616 struct context *tcontext, 617 u16 tclass, 618 struct av_decision *avd, 619 struct extended_perms *xperms) 620 { 621 struct constraint_node *constraint; 622 struct role_allow *ra; 623 struct avtab_key avkey; 624 struct avtab_node *node; 625 struct class_datum *tclass_datum; 626 struct ebitmap *sattr, *tattr; 627 struct ebitmap_node *snode, *tnode; 628 unsigned int i, j; 629 630 avd->allowed = 0; 631 avd->auditallow = 0; 632 avd->auditdeny = 0xffffffff; 633 if (xperms) { 634 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 635 xperms->len = 0; 636 } 637 638 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 639 pr_warn_ratelimited("SELinux: Invalid class %u\n", tclass); 640 return; 641 } 642 643 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 644 645 /* 646 * If a specific type enforcement rule was defined for 647 * this permission check, then use it. 648 */ 649 avkey.target_class = tclass; 650 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 651 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 652 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 653 ebitmap_for_each_positive_bit(sattr, snode, i) { 654 ebitmap_for_each_positive_bit(tattr, tnode, j) { 655 avkey.source_type = i + 1; 656 avkey.target_type = j + 1; 657 for (node = avtab_search_node(&policydb->te_avtab, 658 &avkey); 659 node; 660 node = avtab_search_node_next(node, avkey.specified)) { 661 if (node->key.specified == AVTAB_ALLOWED) 662 avd->allowed |= node->datum.u.data; 663 else if (node->key.specified == AVTAB_AUDITALLOW) 664 avd->auditallow |= node->datum.u.data; 665 else if (node->key.specified == AVTAB_AUDITDENY) 666 avd->auditdeny &= node->datum.u.data; 667 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 668 services_compute_xperms_drivers(xperms, node); 669 } 670 671 /* Check conditional av table for additional permissions */ 672 cond_compute_av(&policydb->te_cond_avtab, &avkey, 673 avd, xperms); 674 675 } 676 } 677 678 /* 679 * Remove any permissions prohibited by a constraint (this includes 680 * the MLS policy). 681 */ 682 constraint = tclass_datum->constraints; 683 while (constraint) { 684 if ((constraint->permissions & (avd->allowed)) && 685 !constraint_expr_eval(policydb, scontext, tcontext, NULL, 686 constraint->expr)) { 687 avd->allowed &= ~(constraint->permissions); 688 } 689 constraint = constraint->next; 690 } 691 692 /* 693 * If checking process transition permission and the 694 * role is changing, then check the (current_role, new_role) 695 * pair. 696 */ 697 if (tclass == policydb->process_class && 698 (avd->allowed & policydb->process_trans_perms) && 699 scontext->role != tcontext->role) { 700 for (ra = policydb->role_allow; ra; ra = ra->next) { 701 if (scontext->role == ra->role && 702 tcontext->role == ra->new_role) 703 break; 704 } 705 if (!ra) 706 avd->allowed &= ~policydb->process_trans_perms; 707 } 708 709 /* 710 * If the given source and target types have boundary 711 * constraint, lazy checks have to mask any violated 712 * permission and notice it to userspace via audit. 713 */ 714 type_attribute_bounds_av(policydb, scontext, tcontext, 715 tclass, avd); 716 } 717 718 static int security_validtrans_handle_fail(struct selinux_policy *policy, 719 struct sidtab_entry *oentry, 720 struct sidtab_entry *nentry, 721 struct sidtab_entry *tentry, 722 u16 tclass) 723 { 724 struct policydb *p = &policy->policydb; 725 struct sidtab *sidtab = policy->sidtab; 726 char *o = NULL, *n = NULL, *t = NULL; 727 u32 olen, nlen, tlen; 728 729 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) 730 goto out; 731 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) 732 goto out; 733 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) 734 goto out; 735 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 736 "op=security_validate_transition seresult=denied" 737 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 738 o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); 739 out: 740 kfree(o); 741 kfree(n); 742 kfree(t); 743 744 if (!enforcing_enabled()) 745 return 0; 746 return -EPERM; 747 } 748 749 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid, 750 u16 orig_tclass, bool user) 751 { 752 struct selinux_policy *policy; 753 struct policydb *policydb; 754 struct sidtab *sidtab; 755 struct sidtab_entry *oentry; 756 struct sidtab_entry *nentry; 757 struct sidtab_entry *tentry; 758 struct class_datum *tclass_datum; 759 struct constraint_node *constraint; 760 u16 tclass; 761 int rc = 0; 762 763 764 if (!selinux_initialized()) 765 return 0; 766 767 rcu_read_lock(); 768 769 policy = rcu_dereference(selinux_state.policy); 770 policydb = &policy->policydb; 771 sidtab = policy->sidtab; 772 773 if (!user) 774 tclass = unmap_class(&policy->map, orig_tclass); 775 else 776 tclass = orig_tclass; 777 778 if (!tclass || tclass > policydb->p_classes.nprim) { 779 rc = -EINVAL; 780 goto out; 781 } 782 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 783 784 oentry = sidtab_search_entry(sidtab, oldsid); 785 if (!oentry) { 786 pr_err("SELinux: %s: unrecognized SID %d\n", 787 __func__, oldsid); 788 rc = -EINVAL; 789 goto out; 790 } 791 792 nentry = sidtab_search_entry(sidtab, newsid); 793 if (!nentry) { 794 pr_err("SELinux: %s: unrecognized SID %d\n", 795 __func__, newsid); 796 rc = -EINVAL; 797 goto out; 798 } 799 800 tentry = sidtab_search_entry(sidtab, tasksid); 801 if (!tentry) { 802 pr_err("SELinux: %s: unrecognized SID %d\n", 803 __func__, tasksid); 804 rc = -EINVAL; 805 goto out; 806 } 807 808 constraint = tclass_datum->validatetrans; 809 while (constraint) { 810 if (!constraint_expr_eval(policydb, &oentry->context, 811 &nentry->context, &tentry->context, 812 constraint->expr)) { 813 if (user) 814 rc = -EPERM; 815 else 816 rc = security_validtrans_handle_fail(policy, 817 oentry, 818 nentry, 819 tentry, 820 tclass); 821 goto out; 822 } 823 constraint = constraint->next; 824 } 825 826 out: 827 rcu_read_unlock(); 828 return rc; 829 } 830 831 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, 832 u16 tclass) 833 { 834 return security_compute_validatetrans(oldsid, newsid, tasksid, 835 tclass, true); 836 } 837 838 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 839 u16 orig_tclass) 840 { 841 return security_compute_validatetrans(oldsid, newsid, tasksid, 842 orig_tclass, false); 843 } 844 845 /* 846 * security_bounded_transition - check whether the given 847 * transition is directed to bounded, or not. 848 * It returns 0, if @newsid is bounded by @oldsid. 849 * Otherwise, it returns error code. 850 * 851 * @oldsid : current security identifier 852 * @newsid : destinated security identifier 853 */ 854 int security_bounded_transition(u32 old_sid, u32 new_sid) 855 { 856 struct selinux_policy *policy; 857 struct policydb *policydb; 858 struct sidtab *sidtab; 859 struct sidtab_entry *old_entry, *new_entry; 860 struct type_datum *type; 861 u32 index; 862 int rc; 863 864 if (!selinux_initialized()) 865 return 0; 866 867 rcu_read_lock(); 868 policy = rcu_dereference(selinux_state.policy); 869 policydb = &policy->policydb; 870 sidtab = policy->sidtab; 871 872 rc = -EINVAL; 873 old_entry = sidtab_search_entry(sidtab, old_sid); 874 if (!old_entry) { 875 pr_err("SELinux: %s: unrecognized SID %u\n", 876 __func__, old_sid); 877 goto out; 878 } 879 880 rc = -EINVAL; 881 new_entry = sidtab_search_entry(sidtab, new_sid); 882 if (!new_entry) { 883 pr_err("SELinux: %s: unrecognized SID %u\n", 884 __func__, new_sid); 885 goto out; 886 } 887 888 rc = 0; 889 /* type/domain unchanged */ 890 if (old_entry->context.type == new_entry->context.type) 891 goto out; 892 893 index = new_entry->context.type; 894 while (true) { 895 type = policydb->type_val_to_struct[index - 1]; 896 BUG_ON(!type); 897 898 /* not bounded anymore */ 899 rc = -EPERM; 900 if (!type->bounds) 901 break; 902 903 /* @newsid is bounded by @oldsid */ 904 rc = 0; 905 if (type->bounds == old_entry->context.type) 906 break; 907 908 index = type->bounds; 909 } 910 911 if (rc) { 912 char *old_name = NULL; 913 char *new_name = NULL; 914 u32 length; 915 916 if (!sidtab_entry_to_string(policydb, sidtab, old_entry, 917 &old_name, &length) && 918 !sidtab_entry_to_string(policydb, sidtab, new_entry, 919 &new_name, &length)) { 920 audit_log(audit_context(), 921 GFP_ATOMIC, AUDIT_SELINUX_ERR, 922 "op=security_bounded_transition " 923 "seresult=denied " 924 "oldcontext=%s newcontext=%s", 925 old_name, new_name); 926 } 927 kfree(new_name); 928 kfree(old_name); 929 } 930 out: 931 rcu_read_unlock(); 932 933 return rc; 934 } 935 936 static void avd_init(struct selinux_policy *policy, struct av_decision *avd) 937 { 938 avd->allowed = 0; 939 avd->auditallow = 0; 940 avd->auditdeny = 0xffffffff; 941 if (policy) 942 avd->seqno = policy->latest_granting; 943 else 944 avd->seqno = 0; 945 avd->flags = 0; 946 } 947 948 static void update_xperms_extended_data(u8 specified, 949 struct extended_perms_data *from, 950 struct extended_perms_data *xp_data) 951 { 952 unsigned int i; 953 954 switch (specified) { 955 case AVTAB_XPERMS_IOCTLDRIVER: 956 memset(xp_data->p, 0xff, sizeof(xp_data->p)); 957 break; 958 case AVTAB_XPERMS_IOCTLFUNCTION: 959 case AVTAB_XPERMS_NLMSG: 960 for (i = 0; i < ARRAY_SIZE(xp_data->p); i++) 961 xp_data->p[i] |= from->p[i]; 962 break; 963 } 964 965 } 966 967 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 968 struct avtab_node *node) 969 { 970 switch (node->datum.u.xperms->specified) { 971 case AVTAB_XPERMS_IOCTLFUNCTION: 972 case AVTAB_XPERMS_NLMSG: 973 if (xpermd->driver != node->datum.u.xperms->driver) 974 return; 975 break; 976 case AVTAB_XPERMS_IOCTLDRIVER: 977 if (!security_xperm_test(node->datum.u.xperms->perms.p, 978 xpermd->driver)) 979 return; 980 break; 981 default: 982 pr_warn_once( 983 "SELinux: unknown extended permission (%u) will be ignored\n", 984 node->datum.u.xperms->specified); 985 return; 986 } 987 988 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 989 xpermd->used |= XPERMS_ALLOWED; 990 update_xperms_extended_data(node->datum.u.xperms->specified, 991 &node->datum.u.xperms->perms, 992 xpermd->allowed); 993 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 994 xpermd->used |= XPERMS_AUDITALLOW; 995 update_xperms_extended_data(node->datum.u.xperms->specified, 996 &node->datum.u.xperms->perms, 997 xpermd->auditallow); 998 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 999 xpermd->used |= XPERMS_DONTAUDIT; 1000 update_xperms_extended_data(node->datum.u.xperms->specified, 1001 &node->datum.u.xperms->perms, 1002 xpermd->dontaudit); 1003 } else { 1004 pr_warn_once("SELinux: unknown specified key (%u)\n", 1005 node->key.specified); 1006 } 1007 } 1008 1009 void security_compute_xperms_decision(u32 ssid, 1010 u32 tsid, 1011 u16 orig_tclass, 1012 u8 driver, 1013 struct extended_perms_decision *xpermd) 1014 { 1015 struct selinux_policy *policy; 1016 struct policydb *policydb; 1017 struct sidtab *sidtab; 1018 u16 tclass; 1019 struct context *scontext, *tcontext; 1020 struct avtab_key avkey; 1021 struct avtab_node *node; 1022 struct ebitmap *sattr, *tattr; 1023 struct ebitmap_node *snode, *tnode; 1024 unsigned int i, j; 1025 1026 xpermd->driver = driver; 1027 xpermd->used = 0; 1028 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1029 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1030 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1031 1032 rcu_read_lock(); 1033 if (!selinux_initialized()) 1034 goto allow; 1035 1036 policy = rcu_dereference(selinux_state.policy); 1037 policydb = &policy->policydb; 1038 sidtab = policy->sidtab; 1039 1040 scontext = sidtab_search(sidtab, ssid); 1041 if (!scontext) { 1042 pr_err("SELinux: %s: unrecognized SID %d\n", 1043 __func__, ssid); 1044 goto out; 1045 } 1046 1047 tcontext = sidtab_search(sidtab, tsid); 1048 if (!tcontext) { 1049 pr_err("SELinux: %s: unrecognized SID %d\n", 1050 __func__, tsid); 1051 goto out; 1052 } 1053 1054 tclass = unmap_class(&policy->map, orig_tclass); 1055 if (unlikely(orig_tclass && !tclass)) { 1056 if (policydb->allow_unknown) 1057 goto allow; 1058 goto out; 1059 } 1060 1061 1062 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1063 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1064 goto out; 1065 } 1066 1067 avkey.target_class = tclass; 1068 avkey.specified = AVTAB_XPERMS; 1069 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 1070 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 1071 ebitmap_for_each_positive_bit(sattr, snode, i) { 1072 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1073 avkey.source_type = i + 1; 1074 avkey.target_type = j + 1; 1075 for (node = avtab_search_node(&policydb->te_avtab, 1076 &avkey); 1077 node; 1078 node = avtab_search_node_next(node, avkey.specified)) 1079 services_compute_xperms_decision(xpermd, node); 1080 1081 cond_compute_xperms(&policydb->te_cond_avtab, 1082 &avkey, xpermd); 1083 } 1084 } 1085 out: 1086 rcu_read_unlock(); 1087 return; 1088 allow: 1089 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1090 goto out; 1091 } 1092 1093 /** 1094 * security_compute_av - Compute access vector decisions. 1095 * @ssid: source security identifier 1096 * @tsid: target security identifier 1097 * @orig_tclass: target security class 1098 * @avd: access vector decisions 1099 * @xperms: extended permissions 1100 * 1101 * Compute a set of access vector decisions based on the 1102 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1103 */ 1104 void security_compute_av(u32 ssid, 1105 u32 tsid, 1106 u16 orig_tclass, 1107 struct av_decision *avd, 1108 struct extended_perms *xperms) 1109 { 1110 struct selinux_policy *policy; 1111 struct policydb *policydb; 1112 struct sidtab *sidtab; 1113 u16 tclass; 1114 struct context *scontext = NULL, *tcontext = NULL; 1115 1116 rcu_read_lock(); 1117 policy = rcu_dereference(selinux_state.policy); 1118 avd_init(policy, avd); 1119 xperms->len = 0; 1120 if (!selinux_initialized()) 1121 goto allow; 1122 1123 policydb = &policy->policydb; 1124 sidtab = policy->sidtab; 1125 1126 scontext = sidtab_search(sidtab, ssid); 1127 if (!scontext) { 1128 pr_err("SELinux: %s: unrecognized SID %d\n", 1129 __func__, ssid); 1130 goto out; 1131 } 1132 1133 /* permissive domain? */ 1134 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1135 avd->flags |= AVD_FLAGS_PERMISSIVE; 1136 1137 tcontext = sidtab_search(sidtab, tsid); 1138 if (!tcontext) { 1139 pr_err("SELinux: %s: unrecognized SID %d\n", 1140 __func__, tsid); 1141 goto out; 1142 } 1143 1144 tclass = unmap_class(&policy->map, orig_tclass); 1145 if (unlikely(orig_tclass && !tclass)) { 1146 if (policydb->allow_unknown) 1147 goto allow; 1148 goto out; 1149 } 1150 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1151 xperms); 1152 map_decision(&policy->map, orig_tclass, avd, 1153 policydb->allow_unknown); 1154 out: 1155 rcu_read_unlock(); 1156 return; 1157 allow: 1158 avd->allowed = 0xffffffff; 1159 goto out; 1160 } 1161 1162 void security_compute_av_user(u32 ssid, 1163 u32 tsid, 1164 u16 tclass, 1165 struct av_decision *avd) 1166 { 1167 struct selinux_policy *policy; 1168 struct policydb *policydb; 1169 struct sidtab *sidtab; 1170 struct context *scontext = NULL, *tcontext = NULL; 1171 1172 rcu_read_lock(); 1173 policy = rcu_dereference(selinux_state.policy); 1174 avd_init(policy, avd); 1175 if (!selinux_initialized()) 1176 goto allow; 1177 1178 policydb = &policy->policydb; 1179 sidtab = policy->sidtab; 1180 1181 scontext = sidtab_search(sidtab, ssid); 1182 if (!scontext) { 1183 pr_err("SELinux: %s: unrecognized SID %d\n", 1184 __func__, ssid); 1185 goto out; 1186 } 1187 1188 /* permissive domain? */ 1189 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1190 avd->flags |= AVD_FLAGS_PERMISSIVE; 1191 1192 tcontext = sidtab_search(sidtab, tsid); 1193 if (!tcontext) { 1194 pr_err("SELinux: %s: unrecognized SID %d\n", 1195 __func__, tsid); 1196 goto out; 1197 } 1198 1199 if (unlikely(!tclass)) { 1200 if (policydb->allow_unknown) 1201 goto allow; 1202 goto out; 1203 } 1204 1205 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1206 NULL); 1207 out: 1208 rcu_read_unlock(); 1209 return; 1210 allow: 1211 avd->allowed = 0xffffffff; 1212 goto out; 1213 } 1214 1215 /* 1216 * Write the security context string representation of 1217 * the context structure `context' into a dynamically 1218 * allocated string of the correct size. Set `*scontext' 1219 * to point to this string and set `*scontext_len' to 1220 * the length of the string. 1221 */ 1222 static int context_struct_to_string(struct policydb *p, 1223 struct context *context, 1224 char **scontext, u32 *scontext_len) 1225 { 1226 char *scontextp; 1227 1228 if (scontext) 1229 *scontext = NULL; 1230 *scontext_len = 0; 1231 1232 if (context->len) { 1233 *scontext_len = context->len; 1234 if (scontext) { 1235 *scontext = kstrdup(context->str, GFP_ATOMIC); 1236 if (!(*scontext)) 1237 return -ENOMEM; 1238 } 1239 return 0; 1240 } 1241 1242 /* Compute the size of the context. */ 1243 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1244 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1245 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1246 *scontext_len += mls_compute_context_len(p, context); 1247 1248 if (!scontext) 1249 return 0; 1250 1251 /* Allocate space for the context; caller must free this space. */ 1252 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1253 if (!scontextp) 1254 return -ENOMEM; 1255 *scontext = scontextp; 1256 1257 /* 1258 * Copy the user name, role name and type name into the context. 1259 */ 1260 scontextp += sprintf(scontextp, "%s:%s:%s", 1261 sym_name(p, SYM_USERS, context->user - 1), 1262 sym_name(p, SYM_ROLES, context->role - 1), 1263 sym_name(p, SYM_TYPES, context->type - 1)); 1264 1265 mls_sid_to_context(p, context, &scontextp); 1266 1267 *scontextp = 0; 1268 1269 return 0; 1270 } 1271 1272 static int sidtab_entry_to_string(struct policydb *p, 1273 struct sidtab *sidtab, 1274 struct sidtab_entry *entry, 1275 char **scontext, u32 *scontext_len) 1276 { 1277 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); 1278 1279 if (rc != -ENOENT) 1280 return rc; 1281 1282 rc = context_struct_to_string(p, &entry->context, scontext, 1283 scontext_len); 1284 if (!rc && scontext) 1285 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); 1286 return rc; 1287 } 1288 1289 #include "initial_sid_to_string.h" 1290 1291 int security_sidtab_hash_stats(char *page) 1292 { 1293 struct selinux_policy *policy; 1294 int rc; 1295 1296 if (!selinux_initialized()) { 1297 pr_err("SELinux: %s: called before initial load_policy\n", 1298 __func__); 1299 return -EINVAL; 1300 } 1301 1302 rcu_read_lock(); 1303 policy = rcu_dereference(selinux_state.policy); 1304 rc = sidtab_hash_stats(policy->sidtab, page); 1305 rcu_read_unlock(); 1306 1307 return rc; 1308 } 1309 1310 const char *security_get_initial_sid_context(u32 sid) 1311 { 1312 if (unlikely(sid > SECINITSID_NUM)) 1313 return NULL; 1314 return initial_sid_to_string[sid]; 1315 } 1316 1317 static int security_sid_to_context_core(u32 sid, char **scontext, 1318 u32 *scontext_len, int force, 1319 int only_invalid) 1320 { 1321 struct selinux_policy *policy; 1322 struct policydb *policydb; 1323 struct sidtab *sidtab; 1324 struct sidtab_entry *entry; 1325 int rc = 0; 1326 1327 if (scontext) 1328 *scontext = NULL; 1329 *scontext_len = 0; 1330 1331 if (!selinux_initialized()) { 1332 if (sid <= SECINITSID_NUM) { 1333 char *scontextp; 1334 const char *s; 1335 1336 /* 1337 * Before the policy is loaded, translate 1338 * SECINITSID_INIT to "kernel", because systemd and 1339 * libselinux < 2.6 take a getcon_raw() result that is 1340 * both non-null and not "kernel" to mean that a policy 1341 * is already loaded. 1342 */ 1343 if (sid == SECINITSID_INIT) 1344 sid = SECINITSID_KERNEL; 1345 1346 s = initial_sid_to_string[sid]; 1347 if (!s) 1348 return -EINVAL; 1349 *scontext_len = strlen(s) + 1; 1350 if (!scontext) 1351 return 0; 1352 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1353 if (!scontextp) 1354 return -ENOMEM; 1355 *scontext = scontextp; 1356 return 0; 1357 } 1358 pr_err("SELinux: %s: called before initial " 1359 "load_policy on unknown SID %d\n", __func__, sid); 1360 return -EINVAL; 1361 } 1362 rcu_read_lock(); 1363 policy = rcu_dereference(selinux_state.policy); 1364 policydb = &policy->policydb; 1365 sidtab = policy->sidtab; 1366 1367 if (force) 1368 entry = sidtab_search_entry_force(sidtab, sid); 1369 else 1370 entry = sidtab_search_entry(sidtab, sid); 1371 if (!entry) { 1372 pr_err("SELinux: %s: unrecognized SID %d\n", 1373 __func__, sid); 1374 rc = -EINVAL; 1375 goto out_unlock; 1376 } 1377 if (only_invalid && !entry->context.len) 1378 goto out_unlock; 1379 1380 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1381 scontext_len); 1382 1383 out_unlock: 1384 rcu_read_unlock(); 1385 return rc; 1386 1387 } 1388 1389 /** 1390 * security_sid_to_context - Obtain a context for a given SID. 1391 * @sid: security identifier, SID 1392 * @scontext: security context 1393 * @scontext_len: length in bytes 1394 * 1395 * Write the string representation of the context associated with @sid 1396 * into a dynamically allocated string of the correct size. Set @scontext 1397 * to point to this string and set @scontext_len to the length of the string. 1398 */ 1399 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1400 { 1401 return security_sid_to_context_core(sid, scontext, 1402 scontext_len, 0, 0); 1403 } 1404 1405 int security_sid_to_context_force(u32 sid, 1406 char **scontext, u32 *scontext_len) 1407 { 1408 return security_sid_to_context_core(sid, scontext, 1409 scontext_len, 1, 0); 1410 } 1411 1412 /** 1413 * security_sid_to_context_inval - Obtain a context for a given SID if it 1414 * is invalid. 1415 * @sid: security identifier, SID 1416 * @scontext: security context 1417 * @scontext_len: length in bytes 1418 * 1419 * Write the string representation of the context associated with @sid 1420 * into a dynamically allocated string of the correct size, but only if the 1421 * context is invalid in the current policy. Set @scontext to point to 1422 * this string (or NULL if the context is valid) and set @scontext_len to 1423 * the length of the string (or 0 if the context is valid). 1424 */ 1425 int security_sid_to_context_inval(u32 sid, 1426 char **scontext, u32 *scontext_len) 1427 { 1428 return security_sid_to_context_core(sid, scontext, 1429 scontext_len, 1, 1); 1430 } 1431 1432 /* 1433 * Caveat: Mutates scontext. 1434 */ 1435 static int string_to_context_struct(struct policydb *pol, 1436 struct sidtab *sidtabp, 1437 char *scontext, 1438 struct context *ctx, 1439 u32 def_sid) 1440 { 1441 struct role_datum *role; 1442 struct type_datum *typdatum; 1443 struct user_datum *usrdatum; 1444 char *scontextp, *p, oldc; 1445 int rc = 0; 1446 1447 context_init(ctx); 1448 1449 /* Parse the security context. */ 1450 1451 rc = -EINVAL; 1452 scontextp = scontext; 1453 1454 /* Extract the user. */ 1455 p = scontextp; 1456 while (*p && *p != ':') 1457 p++; 1458 1459 if (*p == 0) 1460 goto out; 1461 1462 *p++ = 0; 1463 1464 usrdatum = symtab_search(&pol->p_users, scontextp); 1465 if (!usrdatum) 1466 goto out; 1467 1468 ctx->user = usrdatum->value; 1469 1470 /* Extract role. */ 1471 scontextp = p; 1472 while (*p && *p != ':') 1473 p++; 1474 1475 if (*p == 0) 1476 goto out; 1477 1478 *p++ = 0; 1479 1480 role = symtab_search(&pol->p_roles, scontextp); 1481 if (!role) 1482 goto out; 1483 ctx->role = role->value; 1484 1485 /* Extract type. */ 1486 scontextp = p; 1487 while (*p && *p != ':') 1488 p++; 1489 oldc = *p; 1490 *p++ = 0; 1491 1492 typdatum = symtab_search(&pol->p_types, scontextp); 1493 if (!typdatum || typdatum->attribute) 1494 goto out; 1495 1496 ctx->type = typdatum->value; 1497 1498 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1499 if (rc) 1500 goto out; 1501 1502 /* Check the validity of the new context. */ 1503 rc = -EINVAL; 1504 if (!policydb_context_isvalid(pol, ctx)) 1505 goto out; 1506 rc = 0; 1507 out: 1508 if (rc) 1509 context_destroy(ctx); 1510 return rc; 1511 } 1512 1513 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1514 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1515 int force) 1516 { 1517 struct selinux_policy *policy; 1518 struct policydb *policydb; 1519 struct sidtab *sidtab; 1520 char *scontext2, *str = NULL; 1521 struct context context; 1522 int rc = 0; 1523 1524 /* An empty security context is never valid. */ 1525 if (!scontext_len) 1526 return -EINVAL; 1527 1528 /* Copy the string to allow changes and ensure a NUL terminator */ 1529 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1530 if (!scontext2) 1531 return -ENOMEM; 1532 1533 if (!selinux_initialized()) { 1534 u32 i; 1535 1536 for (i = 1; i < SECINITSID_NUM; i++) { 1537 const char *s = initial_sid_to_string[i]; 1538 1539 if (s && !strcmp(s, scontext2)) { 1540 *sid = i; 1541 goto out; 1542 } 1543 } 1544 *sid = SECINITSID_KERNEL; 1545 goto out; 1546 } 1547 *sid = SECSID_NULL; 1548 1549 if (force) { 1550 /* Save another copy for storing in uninterpreted form */ 1551 rc = -ENOMEM; 1552 str = kstrdup(scontext2, gfp_flags); 1553 if (!str) 1554 goto out; 1555 } 1556 retry: 1557 rcu_read_lock(); 1558 policy = rcu_dereference(selinux_state.policy); 1559 policydb = &policy->policydb; 1560 sidtab = policy->sidtab; 1561 rc = string_to_context_struct(policydb, sidtab, scontext2, 1562 &context, def_sid); 1563 if (rc == -EINVAL && force) { 1564 context.str = str; 1565 context.len = strlen(str) + 1; 1566 str = NULL; 1567 } else if (rc) 1568 goto out_unlock; 1569 rc = sidtab_context_to_sid(sidtab, &context, sid); 1570 if (rc == -ESTALE) { 1571 rcu_read_unlock(); 1572 if (context.str) { 1573 str = context.str; 1574 context.str = NULL; 1575 } 1576 context_destroy(&context); 1577 goto retry; 1578 } 1579 context_destroy(&context); 1580 out_unlock: 1581 rcu_read_unlock(); 1582 out: 1583 kfree(scontext2); 1584 kfree(str); 1585 return rc; 1586 } 1587 1588 /** 1589 * security_context_to_sid - Obtain a SID for a given security context. 1590 * @scontext: security context 1591 * @scontext_len: length in bytes 1592 * @sid: security identifier, SID 1593 * @gfp: context for the allocation 1594 * 1595 * Obtains a SID associated with the security context that 1596 * has the string representation specified by @scontext. 1597 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1598 * memory is available, or 0 on success. 1599 */ 1600 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1601 gfp_t gfp) 1602 { 1603 return security_context_to_sid_core(scontext, scontext_len, 1604 sid, SECSID_NULL, gfp, 0); 1605 } 1606 1607 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1608 { 1609 return security_context_to_sid(scontext, strlen(scontext), 1610 sid, gfp); 1611 } 1612 1613 /** 1614 * security_context_to_sid_default - Obtain a SID for a given security context, 1615 * falling back to specified default if needed. 1616 * 1617 * @scontext: security context 1618 * @scontext_len: length in bytes 1619 * @sid: security identifier, SID 1620 * @def_sid: default SID to assign on error 1621 * @gfp_flags: the allocator get-free-page (GFP) flags 1622 * 1623 * Obtains a SID associated with the security context that 1624 * has the string representation specified by @scontext. 1625 * The default SID is passed to the MLS layer to be used to allow 1626 * kernel labeling of the MLS field if the MLS field is not present 1627 * (for upgrading to MLS without full relabel). 1628 * Implicitly forces adding of the context even if it cannot be mapped yet. 1629 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1630 * memory is available, or 0 on success. 1631 */ 1632 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1633 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1634 { 1635 return security_context_to_sid_core(scontext, scontext_len, 1636 sid, def_sid, gfp_flags, 1); 1637 } 1638 1639 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1640 u32 *sid) 1641 { 1642 return security_context_to_sid_core(scontext, scontext_len, 1643 sid, SECSID_NULL, GFP_KERNEL, 1); 1644 } 1645 1646 static int compute_sid_handle_invalid_context( 1647 struct selinux_policy *policy, 1648 struct sidtab_entry *sentry, 1649 struct sidtab_entry *tentry, 1650 u16 tclass, 1651 struct context *newcontext) 1652 { 1653 struct policydb *policydb = &policy->policydb; 1654 struct sidtab *sidtab = policy->sidtab; 1655 char *s = NULL, *t = NULL, *n = NULL; 1656 u32 slen, tlen, nlen; 1657 struct audit_buffer *ab; 1658 1659 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) 1660 goto out; 1661 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) 1662 goto out; 1663 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1664 goto out; 1665 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); 1666 if (!ab) 1667 goto out; 1668 audit_log_format(ab, 1669 "op=security_compute_sid invalid_context="); 1670 /* no need to record the NUL with untrusted strings */ 1671 audit_log_n_untrustedstring(ab, n, nlen - 1); 1672 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1673 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1674 audit_log_end(ab); 1675 out: 1676 kfree(s); 1677 kfree(t); 1678 kfree(n); 1679 if (!enforcing_enabled()) 1680 return 0; 1681 return -EACCES; 1682 } 1683 1684 static void filename_compute_type(struct policydb *policydb, 1685 struct context *newcontext, 1686 u32 stype, u32 ttype, u16 tclass, 1687 const char *objname) 1688 { 1689 struct filename_trans_key ft; 1690 struct filename_trans_datum *datum; 1691 1692 /* 1693 * Most filename trans rules are going to live in specific directories 1694 * like /dev or /var/run. This bitmap will quickly skip rule searches 1695 * if the ttype does not contain any rules. 1696 */ 1697 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1698 return; 1699 1700 ft.ttype = ttype; 1701 ft.tclass = tclass; 1702 ft.name = objname; 1703 1704 datum = policydb_filenametr_search(policydb, &ft); 1705 while (datum) { 1706 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1707 newcontext->type = datum->otype; 1708 return; 1709 } 1710 datum = datum->next; 1711 } 1712 } 1713 1714 static int security_compute_sid(u32 ssid, 1715 u32 tsid, 1716 u16 orig_tclass, 1717 u16 specified, 1718 const char *objname, 1719 u32 *out_sid, 1720 bool kern) 1721 { 1722 struct selinux_policy *policy; 1723 struct policydb *policydb; 1724 struct sidtab *sidtab; 1725 struct class_datum *cladatum; 1726 struct context *scontext, *tcontext, newcontext; 1727 struct sidtab_entry *sentry, *tentry; 1728 struct avtab_key avkey; 1729 struct avtab_node *avnode, *node; 1730 u16 tclass; 1731 int rc = 0; 1732 bool sock; 1733 1734 if (!selinux_initialized()) { 1735 switch (orig_tclass) { 1736 case SECCLASS_PROCESS: /* kernel value */ 1737 *out_sid = ssid; 1738 break; 1739 default: 1740 *out_sid = tsid; 1741 break; 1742 } 1743 goto out; 1744 } 1745 1746 retry: 1747 cladatum = NULL; 1748 context_init(&newcontext); 1749 1750 rcu_read_lock(); 1751 1752 policy = rcu_dereference(selinux_state.policy); 1753 1754 if (kern) { 1755 tclass = unmap_class(&policy->map, orig_tclass); 1756 sock = security_is_socket_class(orig_tclass); 1757 } else { 1758 tclass = orig_tclass; 1759 sock = security_is_socket_class(map_class(&policy->map, 1760 tclass)); 1761 } 1762 1763 policydb = &policy->policydb; 1764 sidtab = policy->sidtab; 1765 1766 sentry = sidtab_search_entry(sidtab, ssid); 1767 if (!sentry) { 1768 pr_err("SELinux: %s: unrecognized SID %d\n", 1769 __func__, ssid); 1770 rc = -EINVAL; 1771 goto out_unlock; 1772 } 1773 tentry = sidtab_search_entry(sidtab, tsid); 1774 if (!tentry) { 1775 pr_err("SELinux: %s: unrecognized SID %d\n", 1776 __func__, tsid); 1777 rc = -EINVAL; 1778 goto out_unlock; 1779 } 1780 1781 scontext = &sentry->context; 1782 tcontext = &tentry->context; 1783 1784 if (tclass && tclass <= policydb->p_classes.nprim) 1785 cladatum = policydb->class_val_to_struct[tclass - 1]; 1786 1787 /* Set the user identity. */ 1788 switch (specified) { 1789 case AVTAB_TRANSITION: 1790 case AVTAB_CHANGE: 1791 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1792 newcontext.user = tcontext->user; 1793 } else { 1794 /* notice this gets both DEFAULT_SOURCE and unset */ 1795 /* Use the process user identity. */ 1796 newcontext.user = scontext->user; 1797 } 1798 break; 1799 case AVTAB_MEMBER: 1800 /* Use the related object owner. */ 1801 newcontext.user = tcontext->user; 1802 break; 1803 } 1804 1805 /* Set the role to default values. */ 1806 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1807 newcontext.role = scontext->role; 1808 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1809 newcontext.role = tcontext->role; 1810 } else { 1811 if ((tclass == policydb->process_class) || sock) 1812 newcontext.role = scontext->role; 1813 else 1814 newcontext.role = OBJECT_R_VAL; 1815 } 1816 1817 /* Set the type. 1818 * Look for a type transition/member/change rule. 1819 */ 1820 avkey.source_type = scontext->type; 1821 avkey.target_type = tcontext->type; 1822 avkey.target_class = tclass; 1823 avkey.specified = specified; 1824 avnode = avtab_search_node(&policydb->te_avtab, &avkey); 1825 1826 /* If no permanent rule, also check for enabled conditional rules */ 1827 if (!avnode) { 1828 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1829 for (; node; node = avtab_search_node_next(node, specified)) { 1830 if (node->key.specified & AVTAB_ENABLED) { 1831 avnode = node; 1832 break; 1833 } 1834 } 1835 } 1836 1837 /* If a permanent rule is found, use the type from 1838 * the type transition/member/change rule. Otherwise, 1839 * set the type to its default values. 1840 */ 1841 if (avnode) { 1842 newcontext.type = avnode->datum.u.data; 1843 } else if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1844 newcontext.type = scontext->type; 1845 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1846 newcontext.type = tcontext->type; 1847 } else { 1848 if ((tclass == policydb->process_class) || sock) { 1849 /* Use the type of process. */ 1850 newcontext.type = scontext->type; 1851 } else { 1852 /* Use the type of the related object. */ 1853 newcontext.type = tcontext->type; 1854 } 1855 } 1856 1857 /* if we have a objname this is a file trans check so check those rules */ 1858 if (objname) 1859 filename_compute_type(policydb, &newcontext, scontext->type, 1860 tcontext->type, tclass, objname); 1861 1862 /* Check for class-specific changes. */ 1863 if (specified & AVTAB_TRANSITION) { 1864 /* Look for a role transition rule. */ 1865 struct role_trans_datum *rtd; 1866 struct role_trans_key rtk = { 1867 .role = scontext->role, 1868 .type = tcontext->type, 1869 .tclass = tclass, 1870 }; 1871 1872 rtd = policydb_roletr_search(policydb, &rtk); 1873 if (rtd) 1874 newcontext.role = rtd->new_role; 1875 } 1876 1877 /* Set the MLS attributes. 1878 This is done last because it may allocate memory. */ 1879 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1880 &newcontext, sock); 1881 if (rc) 1882 goto out_unlock; 1883 1884 /* Check the validity of the context. */ 1885 if (!policydb_context_isvalid(policydb, &newcontext)) { 1886 rc = compute_sid_handle_invalid_context(policy, sentry, 1887 tentry, tclass, 1888 &newcontext); 1889 if (rc) 1890 goto out_unlock; 1891 } 1892 /* Obtain the sid for the context. */ 1893 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1894 if (rc == -ESTALE) { 1895 rcu_read_unlock(); 1896 context_destroy(&newcontext); 1897 goto retry; 1898 } 1899 out_unlock: 1900 rcu_read_unlock(); 1901 context_destroy(&newcontext); 1902 out: 1903 return rc; 1904 } 1905 1906 /** 1907 * security_transition_sid - Compute the SID for a new subject/object. 1908 * @ssid: source security identifier 1909 * @tsid: target security identifier 1910 * @tclass: target security class 1911 * @qstr: object name 1912 * @out_sid: security identifier for new subject/object 1913 * 1914 * Compute a SID to use for labeling a new subject or object in the 1915 * class @tclass based on a SID pair (@ssid, @tsid). 1916 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1917 * if insufficient memory is available, or %0 if the new SID was 1918 * computed successfully. 1919 */ 1920 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1921 const struct qstr *qstr, u32 *out_sid) 1922 { 1923 return security_compute_sid(ssid, tsid, tclass, 1924 AVTAB_TRANSITION, 1925 qstr ? qstr->name : NULL, out_sid, true); 1926 } 1927 1928 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1929 const char *objname, u32 *out_sid) 1930 { 1931 return security_compute_sid(ssid, tsid, tclass, 1932 AVTAB_TRANSITION, 1933 objname, out_sid, false); 1934 } 1935 1936 /** 1937 * security_member_sid - Compute the SID for member selection. 1938 * @ssid: source security identifier 1939 * @tsid: target security identifier 1940 * @tclass: target security class 1941 * @out_sid: security identifier for selected member 1942 * 1943 * Compute a SID to use when selecting a member of a polyinstantiated 1944 * object of class @tclass based on a SID pair (@ssid, @tsid). 1945 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1946 * if insufficient memory is available, or %0 if the SID was 1947 * computed successfully. 1948 */ 1949 int security_member_sid(u32 ssid, 1950 u32 tsid, 1951 u16 tclass, 1952 u32 *out_sid) 1953 { 1954 return security_compute_sid(ssid, tsid, tclass, 1955 AVTAB_MEMBER, NULL, 1956 out_sid, false); 1957 } 1958 1959 /** 1960 * security_change_sid - Compute the SID for object relabeling. 1961 * @ssid: source security identifier 1962 * @tsid: target security identifier 1963 * @tclass: target security class 1964 * @out_sid: security identifier for selected member 1965 * 1966 * Compute a SID to use for relabeling an object of class @tclass 1967 * based on a SID pair (@ssid, @tsid). 1968 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1969 * if insufficient memory is available, or %0 if the SID was 1970 * computed successfully. 1971 */ 1972 int security_change_sid(u32 ssid, 1973 u32 tsid, 1974 u16 tclass, 1975 u32 *out_sid) 1976 { 1977 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1978 out_sid, false); 1979 } 1980 1981 static inline int convert_context_handle_invalid_context( 1982 struct policydb *policydb, 1983 struct context *context) 1984 { 1985 char *s; 1986 u32 len; 1987 1988 if (enforcing_enabled()) 1989 return -EINVAL; 1990 1991 if (!context_struct_to_string(policydb, context, &s, &len)) { 1992 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 1993 s); 1994 kfree(s); 1995 } 1996 return 0; 1997 } 1998 1999 /** 2000 * services_convert_context - Convert a security context across policies. 2001 * @args: populated convert_context_args struct 2002 * @oldc: original context 2003 * @newc: converted context 2004 * @gfp_flags: allocation flags 2005 * 2006 * Convert the values in the security context structure @oldc from the values 2007 * specified in the policy @args->oldp to the values specified in the policy 2008 * @args->newp, storing the new context in @newc, and verifying that the 2009 * context is valid under the new policy. 2010 */ 2011 int services_convert_context(struct convert_context_args *args, 2012 struct context *oldc, struct context *newc, 2013 gfp_t gfp_flags) 2014 { 2015 struct ocontext *oc; 2016 struct role_datum *role; 2017 struct type_datum *typdatum; 2018 struct user_datum *usrdatum; 2019 char *s; 2020 u32 len; 2021 int rc; 2022 2023 if (oldc->str) { 2024 s = kstrdup(oldc->str, gfp_flags); 2025 if (!s) 2026 return -ENOMEM; 2027 2028 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL); 2029 if (rc == -EINVAL) { 2030 /* 2031 * Retain string representation for later mapping. 2032 * 2033 * IMPORTANT: We need to copy the contents of oldc->str 2034 * back into s again because string_to_context_struct() 2035 * may have garbled it. 2036 */ 2037 memcpy(s, oldc->str, oldc->len); 2038 context_init(newc); 2039 newc->str = s; 2040 newc->len = oldc->len; 2041 return 0; 2042 } 2043 kfree(s); 2044 if (rc) { 2045 /* Other error condition, e.g. ENOMEM. */ 2046 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2047 oldc->str, -rc); 2048 return rc; 2049 } 2050 pr_info("SELinux: Context %s became valid (mapped).\n", 2051 oldc->str); 2052 return 0; 2053 } 2054 2055 context_init(newc); 2056 2057 /* Convert the user. */ 2058 usrdatum = symtab_search(&args->newp->p_users, 2059 sym_name(args->oldp, SYM_USERS, oldc->user - 1)); 2060 if (!usrdatum) 2061 goto bad; 2062 newc->user = usrdatum->value; 2063 2064 /* Convert the role. */ 2065 role = symtab_search(&args->newp->p_roles, 2066 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2067 if (!role) 2068 goto bad; 2069 newc->role = role->value; 2070 2071 /* Convert the type. */ 2072 typdatum = symtab_search(&args->newp->p_types, 2073 sym_name(args->oldp, SYM_TYPES, oldc->type - 1)); 2074 if (!typdatum) 2075 goto bad; 2076 newc->type = typdatum->value; 2077 2078 /* Convert the MLS fields if dealing with MLS policies */ 2079 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2080 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2081 if (rc) 2082 goto bad; 2083 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2084 /* 2085 * Switching between non-MLS and MLS policy: 2086 * ensure that the MLS fields of the context for all 2087 * existing entries in the sidtab are filled in with a 2088 * suitable default value, likely taken from one of the 2089 * initial SIDs. 2090 */ 2091 oc = args->newp->ocontexts[OCON_ISID]; 2092 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2093 oc = oc->next; 2094 if (!oc) { 2095 pr_err("SELinux: unable to look up" 2096 " the initial SIDs list\n"); 2097 goto bad; 2098 } 2099 rc = mls_range_set(newc, &oc->context[0].range); 2100 if (rc) 2101 goto bad; 2102 } 2103 2104 /* Check the validity of the new context. */ 2105 if (!policydb_context_isvalid(args->newp, newc)) { 2106 rc = convert_context_handle_invalid_context(args->oldp, oldc); 2107 if (rc) 2108 goto bad; 2109 } 2110 2111 return 0; 2112 bad: 2113 /* Map old representation to string and save it. */ 2114 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2115 if (rc) 2116 return rc; 2117 context_destroy(newc); 2118 newc->str = s; 2119 newc->len = len; 2120 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2121 newc->str); 2122 return 0; 2123 } 2124 2125 static void security_load_policycaps(struct selinux_policy *policy) 2126 { 2127 struct policydb *p; 2128 unsigned int i; 2129 struct ebitmap_node *node; 2130 2131 p = &policy->policydb; 2132 2133 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++) 2134 WRITE_ONCE(selinux_state.policycap[i], 2135 ebitmap_get_bit(&p->policycaps, i)); 2136 2137 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2138 pr_info("SELinux: policy capability %s=%d\n", 2139 selinux_policycap_names[i], 2140 ebitmap_get_bit(&p->policycaps, i)); 2141 2142 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2143 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2144 pr_info("SELinux: unknown policy capability %u\n", 2145 i); 2146 } 2147 } 2148 2149 static int security_preserve_bools(struct selinux_policy *oldpolicy, 2150 struct selinux_policy *newpolicy); 2151 2152 static void selinux_policy_free(struct selinux_policy *policy) 2153 { 2154 if (!policy) 2155 return; 2156 2157 sidtab_destroy(policy->sidtab); 2158 kfree(policy->map.mapping); 2159 policydb_destroy(&policy->policydb); 2160 kfree(policy->sidtab); 2161 kfree(policy); 2162 } 2163 2164 static void selinux_policy_cond_free(struct selinux_policy *policy) 2165 { 2166 cond_policydb_destroy_dup(&policy->policydb); 2167 kfree(policy); 2168 } 2169 2170 void selinux_policy_cancel(struct selinux_load_state *load_state) 2171 { 2172 struct selinux_state *state = &selinux_state; 2173 struct selinux_policy *oldpolicy; 2174 2175 oldpolicy = rcu_dereference_protected(state->policy, 2176 lockdep_is_held(&state->policy_mutex)); 2177 2178 sidtab_cancel_convert(oldpolicy->sidtab); 2179 selinux_policy_free(load_state->policy); 2180 kfree(load_state->convert_data); 2181 } 2182 2183 static void selinux_notify_policy_change(u32 seqno) 2184 { 2185 /* Flush external caches and notify userspace of policy load */ 2186 avc_ss_reset(seqno); 2187 selnl_notify_policyload(seqno); 2188 selinux_status_update_policyload(seqno); 2189 selinux_netlbl_cache_invalidate(); 2190 selinux_xfrm_notify_policyload(); 2191 selinux_ima_measure_state_locked(); 2192 } 2193 2194 void selinux_policy_commit(struct selinux_load_state *load_state) 2195 { 2196 struct selinux_state *state = &selinux_state; 2197 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2198 unsigned long flags; 2199 u32 seqno; 2200 2201 oldpolicy = rcu_dereference_protected(state->policy, 2202 lockdep_is_held(&state->policy_mutex)); 2203 2204 /* If switching between different policy types, log MLS status */ 2205 if (oldpolicy) { 2206 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2207 pr_info("SELinux: Disabling MLS support...\n"); 2208 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2209 pr_info("SELinux: Enabling MLS support...\n"); 2210 } 2211 2212 /* Set latest granting seqno for new policy. */ 2213 if (oldpolicy) 2214 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2215 else 2216 newpolicy->latest_granting = 1; 2217 seqno = newpolicy->latest_granting; 2218 2219 /* Install the new policy. */ 2220 if (oldpolicy) { 2221 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2222 rcu_assign_pointer(state->policy, newpolicy); 2223 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2224 } else { 2225 rcu_assign_pointer(state->policy, newpolicy); 2226 } 2227 2228 /* Load the policycaps from the new policy */ 2229 security_load_policycaps(newpolicy); 2230 2231 if (!selinux_initialized()) { 2232 /* 2233 * After first policy load, the security server is 2234 * marked as initialized and ready to handle requests and 2235 * any objects created prior to policy load are then labeled. 2236 */ 2237 selinux_mark_initialized(); 2238 selinux_complete_init(); 2239 } 2240 2241 /* Free the old policy */ 2242 synchronize_rcu(); 2243 selinux_policy_free(oldpolicy); 2244 kfree(load_state->convert_data); 2245 2246 /* Notify others of the policy change */ 2247 selinux_notify_policy_change(seqno); 2248 } 2249 2250 /** 2251 * security_load_policy - Load a security policy configuration. 2252 * @data: binary policy data 2253 * @len: length of data in bytes 2254 * @load_state: policy load state 2255 * 2256 * Load a new set of security policy configuration data, 2257 * validate it and convert the SID table as necessary. 2258 * This function will flush the access vector cache after 2259 * loading the new policy. 2260 */ 2261 int security_load_policy(void *data, size_t len, 2262 struct selinux_load_state *load_state) 2263 { 2264 struct selinux_state *state = &selinux_state; 2265 struct selinux_policy *newpolicy, *oldpolicy; 2266 struct selinux_policy_convert_data *convert_data; 2267 int rc = 0; 2268 struct policy_file file = { data, len }, *fp = &file; 2269 2270 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); 2271 if (!newpolicy) 2272 return -ENOMEM; 2273 2274 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); 2275 if (!newpolicy->sidtab) { 2276 rc = -ENOMEM; 2277 goto err_policy; 2278 } 2279 2280 rc = policydb_read(&newpolicy->policydb, fp); 2281 if (rc) 2282 goto err_sidtab; 2283 2284 newpolicy->policydb.len = len; 2285 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, 2286 &newpolicy->map); 2287 if (rc) 2288 goto err_policydb; 2289 2290 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); 2291 if (rc) { 2292 pr_err("SELinux: unable to load the initial SIDs\n"); 2293 goto err_mapping; 2294 } 2295 2296 if (!selinux_initialized()) { 2297 /* First policy load, so no need to preserve state from old policy */ 2298 load_state->policy = newpolicy; 2299 load_state->convert_data = NULL; 2300 return 0; 2301 } 2302 2303 oldpolicy = rcu_dereference_protected(state->policy, 2304 lockdep_is_held(&state->policy_mutex)); 2305 2306 /* Preserve active boolean values from the old policy */ 2307 rc = security_preserve_bools(oldpolicy, newpolicy); 2308 if (rc) { 2309 pr_err("SELinux: unable to preserve booleans\n"); 2310 goto err_free_isids; 2311 } 2312 2313 /* 2314 * Convert the internal representations of contexts 2315 * in the new SID table. 2316 */ 2317 2318 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2319 if (!convert_data) { 2320 rc = -ENOMEM; 2321 goto err_free_isids; 2322 } 2323 2324 convert_data->args.oldp = &oldpolicy->policydb; 2325 convert_data->args.newp = &newpolicy->policydb; 2326 2327 convert_data->sidtab_params.args = &convert_data->args; 2328 convert_data->sidtab_params.target = newpolicy->sidtab; 2329 2330 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); 2331 if (rc) { 2332 pr_err("SELinux: unable to convert the internal" 2333 " representation of contexts in the new SID" 2334 " table\n"); 2335 goto err_free_convert_data; 2336 } 2337 2338 load_state->policy = newpolicy; 2339 load_state->convert_data = convert_data; 2340 return 0; 2341 2342 err_free_convert_data: 2343 kfree(convert_data); 2344 err_free_isids: 2345 sidtab_destroy(newpolicy->sidtab); 2346 err_mapping: 2347 kfree(newpolicy->map.mapping); 2348 err_policydb: 2349 policydb_destroy(&newpolicy->policydb); 2350 err_sidtab: 2351 kfree(newpolicy->sidtab); 2352 err_policy: 2353 kfree(newpolicy); 2354 2355 return rc; 2356 } 2357 2358 /** 2359 * ocontext_to_sid - Helper to safely get sid for an ocontext 2360 * @sidtab: SID table 2361 * @c: ocontext structure 2362 * @index: index of the context entry (0 or 1) 2363 * @out_sid: pointer to the resulting SID value 2364 * 2365 * For all ocontexts except OCON_ISID the SID fields are populated 2366 * on-demand when needed. Since updating the SID value is an SMP-sensitive 2367 * operation, this helper must be used to do that safely. 2368 * 2369 * WARNING: This function may return -ESTALE, indicating that the caller 2370 * must retry the operation after re-acquiring the policy pointer! 2371 */ 2372 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, 2373 size_t index, u32 *out_sid) 2374 { 2375 int rc; 2376 u32 sid; 2377 2378 /* Ensure the associated sidtab entry is visible to this thread. */ 2379 sid = smp_load_acquire(&c->sid[index]); 2380 if (!sid) { 2381 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); 2382 if (rc) 2383 return rc; 2384 2385 /* 2386 * Ensure the new sidtab entry is visible to other threads 2387 * when they see the SID. 2388 */ 2389 smp_store_release(&c->sid[index], sid); 2390 } 2391 *out_sid = sid; 2392 return 0; 2393 } 2394 2395 /** 2396 * security_port_sid - Obtain the SID for a port. 2397 * @protocol: protocol number 2398 * @port: port number 2399 * @out_sid: security identifier 2400 */ 2401 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2402 { 2403 struct selinux_policy *policy; 2404 struct policydb *policydb; 2405 struct sidtab *sidtab; 2406 struct ocontext *c; 2407 int rc; 2408 2409 if (!selinux_initialized()) { 2410 *out_sid = SECINITSID_PORT; 2411 return 0; 2412 } 2413 2414 retry: 2415 rc = 0; 2416 rcu_read_lock(); 2417 policy = rcu_dereference(selinux_state.policy); 2418 policydb = &policy->policydb; 2419 sidtab = policy->sidtab; 2420 2421 c = policydb->ocontexts[OCON_PORT]; 2422 while (c) { 2423 if (c->u.port.protocol == protocol && 2424 c->u.port.low_port <= port && 2425 c->u.port.high_port >= port) 2426 break; 2427 c = c->next; 2428 } 2429 2430 if (c) { 2431 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2432 if (rc == -ESTALE) { 2433 rcu_read_unlock(); 2434 goto retry; 2435 } 2436 if (rc) 2437 goto out; 2438 } else { 2439 *out_sid = SECINITSID_PORT; 2440 } 2441 2442 out: 2443 rcu_read_unlock(); 2444 return rc; 2445 } 2446 2447 /** 2448 * security_ib_pkey_sid - Obtain the SID for a pkey. 2449 * @subnet_prefix: Subnet Prefix 2450 * @pkey_num: pkey number 2451 * @out_sid: security identifier 2452 */ 2453 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2454 { 2455 struct selinux_policy *policy; 2456 struct policydb *policydb; 2457 struct sidtab *sidtab; 2458 struct ocontext *c; 2459 int rc; 2460 2461 if (!selinux_initialized()) { 2462 *out_sid = SECINITSID_UNLABELED; 2463 return 0; 2464 } 2465 2466 retry: 2467 rc = 0; 2468 rcu_read_lock(); 2469 policy = rcu_dereference(selinux_state.policy); 2470 policydb = &policy->policydb; 2471 sidtab = policy->sidtab; 2472 2473 c = policydb->ocontexts[OCON_IBPKEY]; 2474 while (c) { 2475 if (c->u.ibpkey.low_pkey <= pkey_num && 2476 c->u.ibpkey.high_pkey >= pkey_num && 2477 c->u.ibpkey.subnet_prefix == subnet_prefix) 2478 break; 2479 2480 c = c->next; 2481 } 2482 2483 if (c) { 2484 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2485 if (rc == -ESTALE) { 2486 rcu_read_unlock(); 2487 goto retry; 2488 } 2489 if (rc) 2490 goto out; 2491 } else 2492 *out_sid = SECINITSID_UNLABELED; 2493 2494 out: 2495 rcu_read_unlock(); 2496 return rc; 2497 } 2498 2499 /** 2500 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2501 * @dev_name: device name 2502 * @port_num: port number 2503 * @out_sid: security identifier 2504 */ 2505 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) 2506 { 2507 struct selinux_policy *policy; 2508 struct policydb *policydb; 2509 struct sidtab *sidtab; 2510 struct ocontext *c; 2511 int rc; 2512 2513 if (!selinux_initialized()) { 2514 *out_sid = SECINITSID_UNLABELED; 2515 return 0; 2516 } 2517 2518 retry: 2519 rc = 0; 2520 rcu_read_lock(); 2521 policy = rcu_dereference(selinux_state.policy); 2522 policydb = &policy->policydb; 2523 sidtab = policy->sidtab; 2524 2525 c = policydb->ocontexts[OCON_IBENDPORT]; 2526 while (c) { 2527 if (c->u.ibendport.port == port_num && 2528 !strncmp(c->u.ibendport.dev_name, 2529 dev_name, 2530 IB_DEVICE_NAME_MAX)) 2531 break; 2532 2533 c = c->next; 2534 } 2535 2536 if (c) { 2537 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2538 if (rc == -ESTALE) { 2539 rcu_read_unlock(); 2540 goto retry; 2541 } 2542 if (rc) 2543 goto out; 2544 } else 2545 *out_sid = SECINITSID_UNLABELED; 2546 2547 out: 2548 rcu_read_unlock(); 2549 return rc; 2550 } 2551 2552 /** 2553 * security_netif_sid - Obtain the SID for a network interface. 2554 * @name: interface name 2555 * @if_sid: interface SID 2556 */ 2557 int security_netif_sid(char *name, u32 *if_sid) 2558 { 2559 struct selinux_policy *policy; 2560 struct policydb *policydb; 2561 struct sidtab *sidtab; 2562 int rc; 2563 struct ocontext *c; 2564 2565 if (!selinux_initialized()) { 2566 *if_sid = SECINITSID_NETIF; 2567 return 0; 2568 } 2569 2570 retry: 2571 rc = 0; 2572 rcu_read_lock(); 2573 policy = rcu_dereference(selinux_state.policy); 2574 policydb = &policy->policydb; 2575 sidtab = policy->sidtab; 2576 2577 c = policydb->ocontexts[OCON_NETIF]; 2578 while (c) { 2579 if (strcmp(name, c->u.name) == 0) 2580 break; 2581 c = c->next; 2582 } 2583 2584 if (c) { 2585 rc = ocontext_to_sid(sidtab, c, 0, if_sid); 2586 if (rc == -ESTALE) { 2587 rcu_read_unlock(); 2588 goto retry; 2589 } 2590 if (rc) 2591 goto out; 2592 } else 2593 *if_sid = SECINITSID_NETIF; 2594 2595 out: 2596 rcu_read_unlock(); 2597 return rc; 2598 } 2599 2600 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2601 { 2602 int i, fail = 0; 2603 2604 for (i = 0; i < 4; i++) 2605 if (addr[i] != (input[i] & mask[i])) { 2606 fail = 1; 2607 break; 2608 } 2609 2610 return !fail; 2611 } 2612 2613 /** 2614 * security_node_sid - Obtain the SID for a node (host). 2615 * @domain: communication domain aka address family 2616 * @addrp: address 2617 * @addrlen: address length in bytes 2618 * @out_sid: security identifier 2619 */ 2620 int security_node_sid(u16 domain, 2621 void *addrp, 2622 u32 addrlen, 2623 u32 *out_sid) 2624 { 2625 struct selinux_policy *policy; 2626 struct policydb *policydb; 2627 struct sidtab *sidtab; 2628 int rc; 2629 struct ocontext *c; 2630 2631 if (!selinux_initialized()) { 2632 *out_sid = SECINITSID_NODE; 2633 return 0; 2634 } 2635 2636 retry: 2637 rcu_read_lock(); 2638 policy = rcu_dereference(selinux_state.policy); 2639 policydb = &policy->policydb; 2640 sidtab = policy->sidtab; 2641 2642 switch (domain) { 2643 case AF_INET: { 2644 u32 addr; 2645 2646 rc = -EINVAL; 2647 if (addrlen != sizeof(u32)) 2648 goto out; 2649 2650 addr = *((u32 *)addrp); 2651 2652 c = policydb->ocontexts[OCON_NODE]; 2653 while (c) { 2654 if (c->u.node.addr == (addr & c->u.node.mask)) 2655 break; 2656 c = c->next; 2657 } 2658 break; 2659 } 2660 2661 case AF_INET6: 2662 rc = -EINVAL; 2663 if (addrlen != sizeof(u64) * 2) 2664 goto out; 2665 c = policydb->ocontexts[OCON_NODE6]; 2666 while (c) { 2667 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2668 c->u.node6.mask)) 2669 break; 2670 c = c->next; 2671 } 2672 break; 2673 2674 default: 2675 rc = 0; 2676 *out_sid = SECINITSID_NODE; 2677 goto out; 2678 } 2679 2680 if (c) { 2681 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2682 if (rc == -ESTALE) { 2683 rcu_read_unlock(); 2684 goto retry; 2685 } 2686 if (rc) 2687 goto out; 2688 } else { 2689 *out_sid = SECINITSID_NODE; 2690 } 2691 2692 rc = 0; 2693 out: 2694 rcu_read_unlock(); 2695 return rc; 2696 } 2697 2698 #define SIDS_NEL 25 2699 2700 /** 2701 * security_get_user_sids - Obtain reachable SIDs for a user. 2702 * @fromsid: starting SID 2703 * @username: username 2704 * @sids: array of reachable SIDs for user 2705 * @nel: number of elements in @sids 2706 * 2707 * Generate the set of SIDs for legal security contexts 2708 * for a given user that can be reached by @fromsid. 2709 * Set *@sids to point to a dynamically allocated 2710 * array containing the set of SIDs. Set *@nel to the 2711 * number of elements in the array. 2712 */ 2713 2714 int security_get_user_sids(u32 fromsid, 2715 char *username, 2716 u32 **sids, 2717 u32 *nel) 2718 { 2719 struct selinux_policy *policy; 2720 struct policydb *policydb; 2721 struct sidtab *sidtab; 2722 struct context *fromcon, usercon; 2723 u32 *mysids = NULL, *mysids2, sid; 2724 u32 i, j, mynel, maxnel = SIDS_NEL; 2725 struct user_datum *user; 2726 struct role_datum *role; 2727 struct ebitmap_node *rnode, *tnode; 2728 int rc; 2729 2730 *sids = NULL; 2731 *nel = 0; 2732 2733 if (!selinux_initialized()) 2734 return 0; 2735 2736 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2737 if (!mysids) 2738 return -ENOMEM; 2739 2740 retry: 2741 mynel = 0; 2742 rcu_read_lock(); 2743 policy = rcu_dereference(selinux_state.policy); 2744 policydb = &policy->policydb; 2745 sidtab = policy->sidtab; 2746 2747 context_init(&usercon); 2748 2749 rc = -EINVAL; 2750 fromcon = sidtab_search(sidtab, fromsid); 2751 if (!fromcon) 2752 goto out_unlock; 2753 2754 rc = -EINVAL; 2755 user = symtab_search(&policydb->p_users, username); 2756 if (!user) 2757 goto out_unlock; 2758 2759 usercon.user = user->value; 2760 2761 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2762 role = policydb->role_val_to_struct[i]; 2763 usercon.role = i + 1; 2764 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2765 usercon.type = j + 1; 2766 2767 if (mls_setup_user_range(policydb, fromcon, user, 2768 &usercon)) 2769 continue; 2770 2771 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2772 if (rc == -ESTALE) { 2773 rcu_read_unlock(); 2774 goto retry; 2775 } 2776 if (rc) 2777 goto out_unlock; 2778 if (mynel < maxnel) { 2779 mysids[mynel++] = sid; 2780 } else { 2781 rc = -ENOMEM; 2782 maxnel += SIDS_NEL; 2783 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2784 if (!mysids2) 2785 goto out_unlock; 2786 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2787 kfree(mysids); 2788 mysids = mysids2; 2789 mysids[mynel++] = sid; 2790 } 2791 } 2792 } 2793 rc = 0; 2794 out_unlock: 2795 rcu_read_unlock(); 2796 if (rc || !mynel) { 2797 kfree(mysids); 2798 return rc; 2799 } 2800 2801 rc = -ENOMEM; 2802 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2803 if (!mysids2) { 2804 kfree(mysids); 2805 return rc; 2806 } 2807 for (i = 0, j = 0; i < mynel; i++) { 2808 struct av_decision dummy_avd; 2809 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2810 SECCLASS_PROCESS, /* kernel value */ 2811 PROCESS__TRANSITION, AVC_STRICT, 2812 &dummy_avd); 2813 if (!rc) 2814 mysids2[j++] = mysids[i]; 2815 cond_resched(); 2816 } 2817 kfree(mysids); 2818 *sids = mysids2; 2819 *nel = j; 2820 return 0; 2821 } 2822 2823 /** 2824 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2825 * @policy: policy 2826 * @fstype: filesystem type 2827 * @path: path from root of mount 2828 * @orig_sclass: file security class 2829 * @sid: SID for path 2830 * 2831 * Obtain a SID to use for a file in a filesystem that 2832 * cannot support xattr or use a fixed labeling behavior like 2833 * transition SIDs or task SIDs. 2834 * 2835 * WARNING: This function may return -ESTALE, indicating that the caller 2836 * must retry the operation after re-acquiring the policy pointer! 2837 */ 2838 static inline int __security_genfs_sid(struct selinux_policy *policy, 2839 const char *fstype, 2840 const char *path, 2841 u16 orig_sclass, 2842 u32 *sid) 2843 { 2844 struct policydb *policydb = &policy->policydb; 2845 struct sidtab *sidtab = policy->sidtab; 2846 u16 sclass; 2847 struct genfs *genfs; 2848 struct ocontext *c; 2849 int cmp = 0; 2850 2851 while (path[0] == '/' && path[1] == '/') 2852 path++; 2853 2854 sclass = unmap_class(&policy->map, orig_sclass); 2855 *sid = SECINITSID_UNLABELED; 2856 2857 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2858 cmp = strcmp(fstype, genfs->fstype); 2859 if (cmp <= 0) 2860 break; 2861 } 2862 2863 if (!genfs || cmp) 2864 return -ENOENT; 2865 2866 for (c = genfs->head; c; c = c->next) { 2867 size_t len = strlen(c->u.name); 2868 if ((!c->v.sclass || sclass == c->v.sclass) && 2869 (strncmp(c->u.name, path, len) == 0)) 2870 break; 2871 } 2872 2873 if (!c) 2874 return -ENOENT; 2875 2876 return ocontext_to_sid(sidtab, c, 0, sid); 2877 } 2878 2879 /** 2880 * security_genfs_sid - Obtain a SID for a file in a filesystem 2881 * @fstype: filesystem type 2882 * @path: path from root of mount 2883 * @orig_sclass: file security class 2884 * @sid: SID for path 2885 * 2886 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2887 * it afterward. 2888 */ 2889 int security_genfs_sid(const char *fstype, 2890 const char *path, 2891 u16 orig_sclass, 2892 u32 *sid) 2893 { 2894 struct selinux_policy *policy; 2895 int retval; 2896 2897 if (!selinux_initialized()) { 2898 *sid = SECINITSID_UNLABELED; 2899 return 0; 2900 } 2901 2902 do { 2903 rcu_read_lock(); 2904 policy = rcu_dereference(selinux_state.policy); 2905 retval = __security_genfs_sid(policy, fstype, path, 2906 orig_sclass, sid); 2907 rcu_read_unlock(); 2908 } while (retval == -ESTALE); 2909 return retval; 2910 } 2911 2912 int selinux_policy_genfs_sid(struct selinux_policy *policy, 2913 const char *fstype, 2914 const char *path, 2915 u16 orig_sclass, 2916 u32 *sid) 2917 { 2918 /* no lock required, policy is not yet accessible by other threads */ 2919 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2920 } 2921 2922 /** 2923 * security_fs_use - Determine how to handle labeling for a filesystem. 2924 * @sb: superblock in question 2925 */ 2926 int security_fs_use(struct super_block *sb) 2927 { 2928 struct selinux_policy *policy; 2929 struct policydb *policydb; 2930 struct sidtab *sidtab; 2931 int rc; 2932 struct ocontext *c; 2933 struct superblock_security_struct *sbsec = selinux_superblock(sb); 2934 const char *fstype = sb->s_type->name; 2935 2936 if (!selinux_initialized()) { 2937 sbsec->behavior = SECURITY_FS_USE_NONE; 2938 sbsec->sid = SECINITSID_UNLABELED; 2939 return 0; 2940 } 2941 2942 retry: 2943 rcu_read_lock(); 2944 policy = rcu_dereference(selinux_state.policy); 2945 policydb = &policy->policydb; 2946 sidtab = policy->sidtab; 2947 2948 c = policydb->ocontexts[OCON_FSUSE]; 2949 while (c) { 2950 if (strcmp(fstype, c->u.name) == 0) 2951 break; 2952 c = c->next; 2953 } 2954 2955 if (c) { 2956 sbsec->behavior = c->v.behavior; 2957 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); 2958 if (rc == -ESTALE) { 2959 rcu_read_unlock(); 2960 goto retry; 2961 } 2962 if (rc) 2963 goto out; 2964 } else { 2965 rc = __security_genfs_sid(policy, fstype, "/", 2966 SECCLASS_DIR, &sbsec->sid); 2967 if (rc == -ESTALE) { 2968 rcu_read_unlock(); 2969 goto retry; 2970 } 2971 if (rc) { 2972 sbsec->behavior = SECURITY_FS_USE_NONE; 2973 rc = 0; 2974 } else { 2975 sbsec->behavior = SECURITY_FS_USE_GENFS; 2976 } 2977 } 2978 2979 out: 2980 rcu_read_unlock(); 2981 return rc; 2982 } 2983 2984 int security_get_bools(struct selinux_policy *policy, 2985 u32 *len, char ***names, int **values) 2986 { 2987 struct policydb *policydb; 2988 u32 i; 2989 int rc; 2990 2991 policydb = &policy->policydb; 2992 2993 *names = NULL; 2994 *values = NULL; 2995 2996 rc = 0; 2997 *len = policydb->p_bools.nprim; 2998 if (!*len) 2999 goto out; 3000 3001 rc = -ENOMEM; 3002 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 3003 if (!*names) 3004 goto err; 3005 3006 rc = -ENOMEM; 3007 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 3008 if (!*values) 3009 goto err; 3010 3011 for (i = 0; i < *len; i++) { 3012 (*values)[i] = policydb->bool_val_to_struct[i]->state; 3013 3014 rc = -ENOMEM; 3015 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 3016 GFP_ATOMIC); 3017 if (!(*names)[i]) 3018 goto err; 3019 } 3020 rc = 0; 3021 out: 3022 return rc; 3023 err: 3024 if (*names) { 3025 for (i = 0; i < *len; i++) 3026 kfree((*names)[i]); 3027 kfree(*names); 3028 } 3029 kfree(*values); 3030 *len = 0; 3031 *names = NULL; 3032 *values = NULL; 3033 goto out; 3034 } 3035 3036 3037 int security_set_bools(u32 len, int *values) 3038 { 3039 struct selinux_state *state = &selinux_state; 3040 struct selinux_policy *newpolicy, *oldpolicy; 3041 int rc; 3042 u32 i, seqno = 0; 3043 3044 if (!selinux_initialized()) 3045 return -EINVAL; 3046 3047 oldpolicy = rcu_dereference_protected(state->policy, 3048 lockdep_is_held(&state->policy_mutex)); 3049 3050 /* Consistency check on number of booleans, should never fail */ 3051 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) 3052 return -EINVAL; 3053 3054 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); 3055 if (!newpolicy) 3056 return -ENOMEM; 3057 3058 /* 3059 * Deep copy only the parts of the policydb that might be 3060 * modified as a result of changing booleans. 3061 */ 3062 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); 3063 if (rc) { 3064 kfree(newpolicy); 3065 return -ENOMEM; 3066 } 3067 3068 /* Update the boolean states in the copy */ 3069 for (i = 0; i < len; i++) { 3070 int new_state = !!values[i]; 3071 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; 3072 3073 if (new_state != old_state) { 3074 audit_log(audit_context(), GFP_ATOMIC, 3075 AUDIT_MAC_CONFIG_CHANGE, 3076 "bool=%s val=%d old_val=%d auid=%u ses=%u", 3077 sym_name(&newpolicy->policydb, SYM_BOOLS, i), 3078 new_state, 3079 old_state, 3080 from_kuid(&init_user_ns, audit_get_loginuid(current)), 3081 audit_get_sessionid(current)); 3082 newpolicy->policydb.bool_val_to_struct[i]->state = new_state; 3083 } 3084 } 3085 3086 /* Re-evaluate the conditional rules in the copy */ 3087 evaluate_cond_nodes(&newpolicy->policydb); 3088 3089 /* Set latest granting seqno for new policy */ 3090 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 3091 seqno = newpolicy->latest_granting; 3092 3093 /* Install the new policy */ 3094 rcu_assign_pointer(state->policy, newpolicy); 3095 3096 /* 3097 * Free the conditional portions of the old policydb 3098 * that were copied for the new policy, and the oldpolicy 3099 * structure itself but not what it references. 3100 */ 3101 synchronize_rcu(); 3102 selinux_policy_cond_free(oldpolicy); 3103 3104 /* Notify others of the policy change */ 3105 selinux_notify_policy_change(seqno); 3106 return 0; 3107 } 3108 3109 int security_get_bool_value(u32 index) 3110 { 3111 struct selinux_policy *policy; 3112 struct policydb *policydb; 3113 int rc; 3114 u32 len; 3115 3116 if (!selinux_initialized()) 3117 return 0; 3118 3119 rcu_read_lock(); 3120 policy = rcu_dereference(selinux_state.policy); 3121 policydb = &policy->policydb; 3122 3123 rc = -EFAULT; 3124 len = policydb->p_bools.nprim; 3125 if (index >= len) 3126 goto out; 3127 3128 rc = policydb->bool_val_to_struct[index]->state; 3129 out: 3130 rcu_read_unlock(); 3131 return rc; 3132 } 3133 3134 static int security_preserve_bools(struct selinux_policy *oldpolicy, 3135 struct selinux_policy *newpolicy) 3136 { 3137 int rc, *bvalues = NULL; 3138 char **bnames = NULL; 3139 struct cond_bool_datum *booldatum; 3140 u32 i, nbools = 0; 3141 3142 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); 3143 if (rc) 3144 goto out; 3145 for (i = 0; i < nbools; i++) { 3146 booldatum = symtab_search(&newpolicy->policydb.p_bools, 3147 bnames[i]); 3148 if (booldatum) 3149 booldatum->state = bvalues[i]; 3150 } 3151 evaluate_cond_nodes(&newpolicy->policydb); 3152 3153 out: 3154 if (bnames) { 3155 for (i = 0; i < nbools; i++) 3156 kfree(bnames[i]); 3157 } 3158 kfree(bnames); 3159 kfree(bvalues); 3160 return rc; 3161 } 3162 3163 /* 3164 * security_sid_mls_copy() - computes a new sid based on the given 3165 * sid and the mls portion of mls_sid. 3166 */ 3167 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 3168 { 3169 struct selinux_policy *policy; 3170 struct policydb *policydb; 3171 struct sidtab *sidtab; 3172 struct context *context1; 3173 struct context *context2; 3174 struct context newcon; 3175 char *s; 3176 u32 len; 3177 int rc; 3178 3179 if (!selinux_initialized()) { 3180 *new_sid = sid; 3181 return 0; 3182 } 3183 3184 retry: 3185 rc = 0; 3186 context_init(&newcon); 3187 3188 rcu_read_lock(); 3189 policy = rcu_dereference(selinux_state.policy); 3190 policydb = &policy->policydb; 3191 sidtab = policy->sidtab; 3192 3193 if (!policydb->mls_enabled) { 3194 *new_sid = sid; 3195 goto out_unlock; 3196 } 3197 3198 rc = -EINVAL; 3199 context1 = sidtab_search(sidtab, sid); 3200 if (!context1) { 3201 pr_err("SELinux: %s: unrecognized SID %d\n", 3202 __func__, sid); 3203 goto out_unlock; 3204 } 3205 3206 rc = -EINVAL; 3207 context2 = sidtab_search(sidtab, mls_sid); 3208 if (!context2) { 3209 pr_err("SELinux: %s: unrecognized SID %d\n", 3210 __func__, mls_sid); 3211 goto out_unlock; 3212 } 3213 3214 newcon.user = context1->user; 3215 newcon.role = context1->role; 3216 newcon.type = context1->type; 3217 rc = mls_context_cpy(&newcon, context2); 3218 if (rc) 3219 goto out_unlock; 3220 3221 /* Check the validity of the new context. */ 3222 if (!policydb_context_isvalid(policydb, &newcon)) { 3223 rc = convert_context_handle_invalid_context(policydb, 3224 &newcon); 3225 if (rc) { 3226 if (!context_struct_to_string(policydb, &newcon, &s, 3227 &len)) { 3228 struct audit_buffer *ab; 3229 3230 ab = audit_log_start(audit_context(), 3231 GFP_ATOMIC, 3232 AUDIT_SELINUX_ERR); 3233 audit_log_format(ab, 3234 "op=security_sid_mls_copy invalid_context="); 3235 /* don't record NUL with untrusted strings */ 3236 audit_log_n_untrustedstring(ab, s, len - 1); 3237 audit_log_end(ab); 3238 kfree(s); 3239 } 3240 goto out_unlock; 3241 } 3242 } 3243 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3244 if (rc == -ESTALE) { 3245 rcu_read_unlock(); 3246 context_destroy(&newcon); 3247 goto retry; 3248 } 3249 out_unlock: 3250 rcu_read_unlock(); 3251 context_destroy(&newcon); 3252 return rc; 3253 } 3254 3255 /** 3256 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3257 * @nlbl_sid: NetLabel SID 3258 * @nlbl_type: NetLabel labeling protocol type 3259 * @xfrm_sid: XFRM SID 3260 * @peer_sid: network peer sid 3261 * 3262 * Description: 3263 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3264 * resolved into a single SID it is returned via @peer_sid and the function 3265 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3266 * returns a negative value. A table summarizing the behavior is below: 3267 * 3268 * | function return | @sid 3269 * ------------------------------+-----------------+----------------- 3270 * no peer labels | 0 | SECSID_NULL 3271 * single peer label | 0 | <peer_label> 3272 * multiple, consistent labels | 0 | <peer_label> 3273 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3274 * 3275 */ 3276 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 3277 u32 xfrm_sid, 3278 u32 *peer_sid) 3279 { 3280 struct selinux_policy *policy; 3281 struct policydb *policydb; 3282 struct sidtab *sidtab; 3283 int rc; 3284 struct context *nlbl_ctx; 3285 struct context *xfrm_ctx; 3286 3287 *peer_sid = SECSID_NULL; 3288 3289 /* handle the common (which also happens to be the set of easy) cases 3290 * right away, these two if statements catch everything involving a 3291 * single or absent peer SID/label */ 3292 if (xfrm_sid == SECSID_NULL) { 3293 *peer_sid = nlbl_sid; 3294 return 0; 3295 } 3296 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3297 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3298 * is present */ 3299 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3300 *peer_sid = xfrm_sid; 3301 return 0; 3302 } 3303 3304 if (!selinux_initialized()) 3305 return 0; 3306 3307 rcu_read_lock(); 3308 policy = rcu_dereference(selinux_state.policy); 3309 policydb = &policy->policydb; 3310 sidtab = policy->sidtab; 3311 3312 /* 3313 * We don't need to check initialized here since the only way both 3314 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3315 * security server was initialized and state->initialized was true. 3316 */ 3317 if (!policydb->mls_enabled) { 3318 rc = 0; 3319 goto out; 3320 } 3321 3322 rc = -EINVAL; 3323 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3324 if (!nlbl_ctx) { 3325 pr_err("SELinux: %s: unrecognized SID %d\n", 3326 __func__, nlbl_sid); 3327 goto out; 3328 } 3329 rc = -EINVAL; 3330 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3331 if (!xfrm_ctx) { 3332 pr_err("SELinux: %s: unrecognized SID %d\n", 3333 __func__, xfrm_sid); 3334 goto out; 3335 } 3336 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3337 if (rc) 3338 goto out; 3339 3340 /* at present NetLabel SIDs/labels really only carry MLS 3341 * information so if the MLS portion of the NetLabel SID 3342 * matches the MLS portion of the labeled XFRM SID/label 3343 * then pass along the XFRM SID as it is the most 3344 * expressive */ 3345 *peer_sid = xfrm_sid; 3346 out: 3347 rcu_read_unlock(); 3348 return rc; 3349 } 3350 3351 static int get_classes_callback(void *k, void *d, void *args) 3352 { 3353 struct class_datum *datum = d; 3354 char *name = k, **classes = args; 3355 u32 value = datum->value - 1; 3356 3357 classes[value] = kstrdup(name, GFP_ATOMIC); 3358 if (!classes[value]) 3359 return -ENOMEM; 3360 3361 return 0; 3362 } 3363 3364 int security_get_classes(struct selinux_policy *policy, 3365 char ***classes, u32 *nclasses) 3366 { 3367 struct policydb *policydb; 3368 int rc; 3369 3370 policydb = &policy->policydb; 3371 3372 rc = -ENOMEM; 3373 *nclasses = policydb->p_classes.nprim; 3374 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3375 if (!*classes) 3376 goto out; 3377 3378 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3379 *classes); 3380 if (rc) { 3381 u32 i; 3382 3383 for (i = 0; i < *nclasses; i++) 3384 kfree((*classes)[i]); 3385 kfree(*classes); 3386 } 3387 3388 out: 3389 return rc; 3390 } 3391 3392 static int get_permissions_callback(void *k, void *d, void *args) 3393 { 3394 struct perm_datum *datum = d; 3395 char *name = k, **perms = args; 3396 u32 value = datum->value - 1; 3397 3398 perms[value] = kstrdup(name, GFP_ATOMIC); 3399 if (!perms[value]) 3400 return -ENOMEM; 3401 3402 return 0; 3403 } 3404 3405 int security_get_permissions(struct selinux_policy *policy, 3406 const char *class, char ***perms, u32 *nperms) 3407 { 3408 struct policydb *policydb; 3409 u32 i; 3410 int rc; 3411 struct class_datum *match; 3412 3413 policydb = &policy->policydb; 3414 3415 rc = -EINVAL; 3416 match = symtab_search(&policydb->p_classes, class); 3417 if (!match) { 3418 pr_err("SELinux: %s: unrecognized class %s\n", 3419 __func__, class); 3420 goto out; 3421 } 3422 3423 rc = -ENOMEM; 3424 *nperms = match->permissions.nprim; 3425 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3426 if (!*perms) 3427 goto out; 3428 3429 if (match->comdatum) { 3430 rc = hashtab_map(&match->comdatum->permissions.table, 3431 get_permissions_callback, *perms); 3432 if (rc) 3433 goto err; 3434 } 3435 3436 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3437 *perms); 3438 if (rc) 3439 goto err; 3440 3441 out: 3442 return rc; 3443 3444 err: 3445 for (i = 0; i < *nperms; i++) 3446 kfree((*perms)[i]); 3447 kfree(*perms); 3448 return rc; 3449 } 3450 3451 int security_get_reject_unknown(void) 3452 { 3453 struct selinux_policy *policy; 3454 int value; 3455 3456 if (!selinux_initialized()) 3457 return 0; 3458 3459 rcu_read_lock(); 3460 policy = rcu_dereference(selinux_state.policy); 3461 value = policy->policydb.reject_unknown; 3462 rcu_read_unlock(); 3463 return value; 3464 } 3465 3466 int security_get_allow_unknown(void) 3467 { 3468 struct selinux_policy *policy; 3469 int value; 3470 3471 if (!selinux_initialized()) 3472 return 0; 3473 3474 rcu_read_lock(); 3475 policy = rcu_dereference(selinux_state.policy); 3476 value = policy->policydb.allow_unknown; 3477 rcu_read_unlock(); 3478 return value; 3479 } 3480 3481 /** 3482 * security_policycap_supported - Check for a specific policy capability 3483 * @req_cap: capability 3484 * 3485 * Description: 3486 * This function queries the currently loaded policy to see if it supports the 3487 * capability specified by @req_cap. Returns true (1) if the capability is 3488 * supported, false (0) if it isn't supported. 3489 * 3490 */ 3491 int security_policycap_supported(unsigned int req_cap) 3492 { 3493 struct selinux_policy *policy; 3494 int rc; 3495 3496 if (!selinux_initialized()) 3497 return 0; 3498 3499 rcu_read_lock(); 3500 policy = rcu_dereference(selinux_state.policy); 3501 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3502 rcu_read_unlock(); 3503 3504 return rc; 3505 } 3506 3507 struct selinux_audit_rule { 3508 u32 au_seqno; 3509 struct context au_ctxt; 3510 }; 3511 3512 void selinux_audit_rule_free(void *vrule) 3513 { 3514 struct selinux_audit_rule *rule = vrule; 3515 3516 if (rule) { 3517 context_destroy(&rule->au_ctxt); 3518 kfree(rule); 3519 } 3520 } 3521 3522 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, 3523 gfp_t gfp) 3524 { 3525 struct selinux_state *state = &selinux_state; 3526 struct selinux_policy *policy; 3527 struct policydb *policydb; 3528 struct selinux_audit_rule *tmprule; 3529 struct role_datum *roledatum; 3530 struct type_datum *typedatum; 3531 struct user_datum *userdatum; 3532 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3533 int rc = 0; 3534 3535 *rule = NULL; 3536 3537 if (!selinux_initialized()) 3538 return -EOPNOTSUPP; 3539 3540 switch (field) { 3541 case AUDIT_SUBJ_USER: 3542 case AUDIT_SUBJ_ROLE: 3543 case AUDIT_SUBJ_TYPE: 3544 case AUDIT_OBJ_USER: 3545 case AUDIT_OBJ_ROLE: 3546 case AUDIT_OBJ_TYPE: 3547 /* only 'equals' and 'not equals' fit user, role, and type */ 3548 if (op != Audit_equal && op != Audit_not_equal) 3549 return -EINVAL; 3550 break; 3551 case AUDIT_SUBJ_SEN: 3552 case AUDIT_SUBJ_CLR: 3553 case AUDIT_OBJ_LEV_LOW: 3554 case AUDIT_OBJ_LEV_HIGH: 3555 /* we do not allow a range, indicated by the presence of '-' */ 3556 if (strchr(rulestr, '-')) 3557 return -EINVAL; 3558 break; 3559 default: 3560 /* only the above fields are valid */ 3561 return -EINVAL; 3562 } 3563 3564 tmprule = kzalloc(sizeof(struct selinux_audit_rule), gfp); 3565 if (!tmprule) 3566 return -ENOMEM; 3567 context_init(&tmprule->au_ctxt); 3568 3569 rcu_read_lock(); 3570 policy = rcu_dereference(state->policy); 3571 policydb = &policy->policydb; 3572 tmprule->au_seqno = policy->latest_granting; 3573 switch (field) { 3574 case AUDIT_SUBJ_USER: 3575 case AUDIT_OBJ_USER: 3576 userdatum = symtab_search(&policydb->p_users, rulestr); 3577 if (!userdatum) { 3578 rc = -EINVAL; 3579 goto err; 3580 } 3581 tmprule->au_ctxt.user = userdatum->value; 3582 break; 3583 case AUDIT_SUBJ_ROLE: 3584 case AUDIT_OBJ_ROLE: 3585 roledatum = symtab_search(&policydb->p_roles, rulestr); 3586 if (!roledatum) { 3587 rc = -EINVAL; 3588 goto err; 3589 } 3590 tmprule->au_ctxt.role = roledatum->value; 3591 break; 3592 case AUDIT_SUBJ_TYPE: 3593 case AUDIT_OBJ_TYPE: 3594 typedatum = symtab_search(&policydb->p_types, rulestr); 3595 if (!typedatum) { 3596 rc = -EINVAL; 3597 goto err; 3598 } 3599 tmprule->au_ctxt.type = typedatum->value; 3600 break; 3601 case AUDIT_SUBJ_SEN: 3602 case AUDIT_SUBJ_CLR: 3603 case AUDIT_OBJ_LEV_LOW: 3604 case AUDIT_OBJ_LEV_HIGH: 3605 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3606 GFP_ATOMIC); 3607 if (rc) 3608 goto err; 3609 break; 3610 } 3611 rcu_read_unlock(); 3612 3613 *rule = tmprule; 3614 return 0; 3615 3616 err: 3617 rcu_read_unlock(); 3618 selinux_audit_rule_free(tmprule); 3619 *rule = NULL; 3620 return rc; 3621 } 3622 3623 /* Check to see if the rule contains any selinux fields */ 3624 int selinux_audit_rule_known(struct audit_krule *rule) 3625 { 3626 u32 i; 3627 3628 for (i = 0; i < rule->field_count; i++) { 3629 struct audit_field *f = &rule->fields[i]; 3630 switch (f->type) { 3631 case AUDIT_SUBJ_USER: 3632 case AUDIT_SUBJ_ROLE: 3633 case AUDIT_SUBJ_TYPE: 3634 case AUDIT_SUBJ_SEN: 3635 case AUDIT_SUBJ_CLR: 3636 case AUDIT_OBJ_USER: 3637 case AUDIT_OBJ_ROLE: 3638 case AUDIT_OBJ_TYPE: 3639 case AUDIT_OBJ_LEV_LOW: 3640 case AUDIT_OBJ_LEV_HIGH: 3641 return 1; 3642 } 3643 } 3644 3645 return 0; 3646 } 3647 3648 int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule) 3649 { 3650 struct selinux_state *state = &selinux_state; 3651 struct selinux_policy *policy; 3652 struct context *ctxt; 3653 struct mls_level *level; 3654 struct selinux_audit_rule *rule = vrule; 3655 int match = 0; 3656 3657 if (unlikely(!rule)) { 3658 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3659 return -ENOENT; 3660 } 3661 3662 if (!selinux_initialized()) 3663 return 0; 3664 3665 rcu_read_lock(); 3666 3667 policy = rcu_dereference(state->policy); 3668 3669 if (rule->au_seqno < policy->latest_granting) { 3670 match = -ESTALE; 3671 goto out; 3672 } 3673 3674 ctxt = sidtab_search(policy->sidtab, prop->selinux.secid); 3675 if (unlikely(!ctxt)) { 3676 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3677 prop->selinux.secid); 3678 match = -ENOENT; 3679 goto out; 3680 } 3681 3682 /* a field/op pair that is not caught here will simply fall through 3683 without a match */ 3684 switch (field) { 3685 case AUDIT_SUBJ_USER: 3686 case AUDIT_OBJ_USER: 3687 switch (op) { 3688 case Audit_equal: 3689 match = (ctxt->user == rule->au_ctxt.user); 3690 break; 3691 case Audit_not_equal: 3692 match = (ctxt->user != rule->au_ctxt.user); 3693 break; 3694 } 3695 break; 3696 case AUDIT_SUBJ_ROLE: 3697 case AUDIT_OBJ_ROLE: 3698 switch (op) { 3699 case Audit_equal: 3700 match = (ctxt->role == rule->au_ctxt.role); 3701 break; 3702 case Audit_not_equal: 3703 match = (ctxt->role != rule->au_ctxt.role); 3704 break; 3705 } 3706 break; 3707 case AUDIT_SUBJ_TYPE: 3708 case AUDIT_OBJ_TYPE: 3709 switch (op) { 3710 case Audit_equal: 3711 match = (ctxt->type == rule->au_ctxt.type); 3712 break; 3713 case Audit_not_equal: 3714 match = (ctxt->type != rule->au_ctxt.type); 3715 break; 3716 } 3717 break; 3718 case AUDIT_SUBJ_SEN: 3719 case AUDIT_SUBJ_CLR: 3720 case AUDIT_OBJ_LEV_LOW: 3721 case AUDIT_OBJ_LEV_HIGH: 3722 level = ((field == AUDIT_SUBJ_SEN || 3723 field == AUDIT_OBJ_LEV_LOW) ? 3724 &ctxt->range.level[0] : &ctxt->range.level[1]); 3725 switch (op) { 3726 case Audit_equal: 3727 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3728 level); 3729 break; 3730 case Audit_not_equal: 3731 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3732 level); 3733 break; 3734 case Audit_lt: 3735 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3736 level) && 3737 !mls_level_eq(&rule->au_ctxt.range.level[0], 3738 level)); 3739 break; 3740 case Audit_le: 3741 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3742 level); 3743 break; 3744 case Audit_gt: 3745 match = (mls_level_dom(level, 3746 &rule->au_ctxt.range.level[0]) && 3747 !mls_level_eq(level, 3748 &rule->au_ctxt.range.level[0])); 3749 break; 3750 case Audit_ge: 3751 match = mls_level_dom(level, 3752 &rule->au_ctxt.range.level[0]); 3753 break; 3754 } 3755 } 3756 3757 out: 3758 rcu_read_unlock(); 3759 return match; 3760 } 3761 3762 static int aurule_avc_callback(u32 event) 3763 { 3764 if (event == AVC_CALLBACK_RESET) 3765 return audit_update_lsm_rules(); 3766 return 0; 3767 } 3768 3769 static int __init aurule_init(void) 3770 { 3771 int err; 3772 3773 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3774 if (err) 3775 panic("avc_add_callback() failed, error %d\n", err); 3776 3777 return err; 3778 } 3779 __initcall(aurule_init); 3780 3781 #ifdef CONFIG_NETLABEL 3782 /** 3783 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3784 * @secattr: the NetLabel packet security attributes 3785 * @sid: the SELinux SID 3786 * 3787 * Description: 3788 * Attempt to cache the context in @ctx, which was derived from the packet in 3789 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3790 * already been initialized. 3791 * 3792 */ 3793 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3794 u32 sid) 3795 { 3796 u32 *sid_cache; 3797 3798 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3799 if (sid_cache == NULL) 3800 return; 3801 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3802 if (secattr->cache == NULL) { 3803 kfree(sid_cache); 3804 return; 3805 } 3806 3807 *sid_cache = sid; 3808 secattr->cache->free = kfree; 3809 secattr->cache->data = sid_cache; 3810 secattr->flags |= NETLBL_SECATTR_CACHE; 3811 } 3812 3813 /** 3814 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3815 * @secattr: the NetLabel packet security attributes 3816 * @sid: the SELinux SID 3817 * 3818 * Description: 3819 * Convert the given NetLabel security attributes in @secattr into a 3820 * SELinux SID. If the @secattr field does not contain a full SELinux 3821 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3822 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3823 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3824 * conversion for future lookups. Returns zero on success, negative values on 3825 * failure. 3826 * 3827 */ 3828 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3829 u32 *sid) 3830 { 3831 struct selinux_policy *policy; 3832 struct policydb *policydb; 3833 struct sidtab *sidtab; 3834 int rc; 3835 struct context *ctx; 3836 struct context ctx_new; 3837 3838 if (!selinux_initialized()) { 3839 *sid = SECSID_NULL; 3840 return 0; 3841 } 3842 3843 retry: 3844 rc = 0; 3845 rcu_read_lock(); 3846 policy = rcu_dereference(selinux_state.policy); 3847 policydb = &policy->policydb; 3848 sidtab = policy->sidtab; 3849 3850 if (secattr->flags & NETLBL_SECATTR_CACHE) 3851 *sid = *(u32 *)secattr->cache->data; 3852 else if (secattr->flags & NETLBL_SECATTR_SECID) 3853 *sid = secattr->attr.secid; 3854 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3855 rc = -EIDRM; 3856 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3857 if (ctx == NULL) 3858 goto out; 3859 3860 context_init(&ctx_new); 3861 ctx_new.user = ctx->user; 3862 ctx_new.role = ctx->role; 3863 ctx_new.type = ctx->type; 3864 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3865 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3866 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3867 if (rc) 3868 goto out; 3869 } 3870 rc = -EIDRM; 3871 if (!mls_context_isvalid(policydb, &ctx_new)) { 3872 ebitmap_destroy(&ctx_new.range.level[0].cat); 3873 goto out; 3874 } 3875 3876 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3877 ebitmap_destroy(&ctx_new.range.level[0].cat); 3878 if (rc == -ESTALE) { 3879 rcu_read_unlock(); 3880 goto retry; 3881 } 3882 if (rc) 3883 goto out; 3884 3885 security_netlbl_cache_add(secattr, *sid); 3886 } else 3887 *sid = SECSID_NULL; 3888 3889 out: 3890 rcu_read_unlock(); 3891 return rc; 3892 } 3893 3894 /** 3895 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3896 * @sid: the SELinux SID 3897 * @secattr: the NetLabel packet security attributes 3898 * 3899 * Description: 3900 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3901 * Returns zero on success, negative values on failure. 3902 * 3903 */ 3904 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3905 { 3906 struct selinux_policy *policy; 3907 struct policydb *policydb; 3908 int rc; 3909 struct context *ctx; 3910 3911 if (!selinux_initialized()) 3912 return 0; 3913 3914 rcu_read_lock(); 3915 policy = rcu_dereference(selinux_state.policy); 3916 policydb = &policy->policydb; 3917 3918 rc = -ENOENT; 3919 ctx = sidtab_search(policy->sidtab, sid); 3920 if (ctx == NULL) 3921 goto out; 3922 3923 rc = -ENOMEM; 3924 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3925 GFP_ATOMIC); 3926 if (secattr->domain == NULL) 3927 goto out; 3928 3929 secattr->attr.secid = sid; 3930 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3931 mls_export_netlbl_lvl(policydb, ctx, secattr); 3932 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3933 out: 3934 rcu_read_unlock(); 3935 return rc; 3936 } 3937 #endif /* CONFIG_NETLABEL */ 3938 3939 /** 3940 * __security_read_policy - read the policy. 3941 * @policy: SELinux policy 3942 * @data: binary policy data 3943 * @len: length of data in bytes 3944 * 3945 */ 3946 static int __security_read_policy(struct selinux_policy *policy, 3947 void *data, size_t *len) 3948 { 3949 int rc; 3950 struct policy_file fp; 3951 3952 fp.data = data; 3953 fp.len = *len; 3954 3955 rc = policydb_write(&policy->policydb, &fp); 3956 if (rc) 3957 return rc; 3958 3959 *len = (unsigned long)fp.data - (unsigned long)data; 3960 return 0; 3961 } 3962 3963 /** 3964 * security_read_policy - read the policy. 3965 * @data: binary policy data 3966 * @len: length of data in bytes 3967 * 3968 */ 3969 int security_read_policy(void **data, size_t *len) 3970 { 3971 struct selinux_state *state = &selinux_state; 3972 struct selinux_policy *policy; 3973 3974 policy = rcu_dereference_protected( 3975 state->policy, lockdep_is_held(&state->policy_mutex)); 3976 if (!policy) 3977 return -EINVAL; 3978 3979 *len = policy->policydb.len; 3980 *data = vmalloc_user(*len); 3981 if (!*data) 3982 return -ENOMEM; 3983 3984 return __security_read_policy(policy, *data, len); 3985 } 3986 3987 /** 3988 * security_read_state_kernel - read the policy. 3989 * @data: binary policy data 3990 * @len: length of data in bytes 3991 * 3992 * Allocates kernel memory for reading SELinux policy. 3993 * This function is for internal use only and should not 3994 * be used for returning data to user space. 3995 * 3996 * This function must be called with policy_mutex held. 3997 */ 3998 int security_read_state_kernel(void **data, size_t *len) 3999 { 4000 int err; 4001 struct selinux_state *state = &selinux_state; 4002 struct selinux_policy *policy; 4003 4004 policy = rcu_dereference_protected( 4005 state->policy, lockdep_is_held(&state->policy_mutex)); 4006 if (!policy) 4007 return -EINVAL; 4008 4009 *len = policy->policydb.len; 4010 *data = vmalloc(*len); 4011 if (!*data) 4012 return -ENOMEM; 4013 4014 err = __security_read_policy(policy, *data, len); 4015 if (err) { 4016 vfree(*data); 4017 *data = NULL; 4018 *len = 0; 4019 } 4020 return err; 4021 } 4022