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/parser.h> 50 #include <linux/vmalloc.h> 51 #include <linux/lsm_hooks.h> 52 #include <net/netlabel.h> 53 54 #include "flask.h" 55 #include "avc.h" 56 #include "avc_ss.h" 57 #include "security.h" 58 #include "context.h" 59 #include "policydb.h" 60 #include "sidtab.h" 61 #include "services.h" 62 #include "conditional.h" 63 #include "mls.h" 64 #include "objsec.h" 65 #include "netlabel.h" 66 #include "xfrm.h" 67 #include "ebitmap.h" 68 #include "audit.h" 69 #include "policycap_names.h" 70 #include "ima.h" 71 72 struct selinux_policy_convert_data { 73 struct convert_context_args args; 74 struct sidtab_convert_params sidtab_params; 75 }; 76 77 /* Forward declaration. */ 78 static int context_struct_to_string(struct policydb *policydb, 79 struct context *context, 80 char **scontext, 81 u32 *scontext_len); 82 83 static int sidtab_entry_to_string(struct policydb *policydb, 84 struct sidtab *sidtab, 85 struct sidtab_entry *entry, 86 char **scontext, 87 u32 *scontext_len); 88 89 static void context_struct_compute_av(struct policydb *policydb, 90 struct context *scontext, 91 struct context *tcontext, 92 u16 tclass, 93 struct av_decision *avd, 94 struct extended_perms *xperms); 95 96 static int selinux_set_mapping(struct policydb *pol, 97 const struct security_class_mapping *map, 98 struct selinux_map *out_map) 99 { 100 u16 i, j; 101 bool print_unknown_handle = false; 102 103 /* Find number of classes in the input mapping */ 104 if (!map) 105 return -EINVAL; 106 i = 0; 107 while (map[i].name) 108 i++; 109 110 /* Allocate space for the class records, plus one for class zero */ 111 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 112 if (!out_map->mapping) 113 return -ENOMEM; 114 115 /* Store the raw class and permission values */ 116 j = 0; 117 while (map[j].name) { 118 const struct security_class_mapping *p_in = map + (j++); 119 struct selinux_mapping *p_out = out_map->mapping + j; 120 u16 k; 121 122 /* An empty class string skips ahead */ 123 if (!strcmp(p_in->name, "")) { 124 p_out->num_perms = 0; 125 continue; 126 } 127 128 p_out->value = string_to_security_class(pol, p_in->name); 129 if (!p_out->value) { 130 pr_info("SELinux: Class %s not defined in policy.\n", 131 p_in->name); 132 if (pol->reject_unknown) 133 goto err; 134 p_out->num_perms = 0; 135 print_unknown_handle = true; 136 continue; 137 } 138 139 k = 0; 140 while (p_in->perms[k]) { 141 /* An empty permission string skips ahead */ 142 if (!*p_in->perms[k]) { 143 k++; 144 continue; 145 } 146 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 147 p_in->perms[k]); 148 if (!p_out->perms[k]) { 149 pr_info("SELinux: Permission %s in class %s not defined in policy.\n", 150 p_in->perms[k], p_in->name); 151 if (pol->reject_unknown) 152 goto err; 153 print_unknown_handle = true; 154 } 155 156 k++; 157 } 158 p_out->num_perms = k; 159 } 160 161 if (print_unknown_handle) 162 pr_info("SELinux: the above unknown classes and permissions will be %s\n", 163 pol->allow_unknown ? "allowed" : "denied"); 164 165 out_map->size = i; 166 return 0; 167 err: 168 kfree(out_map->mapping); 169 out_map->mapping = NULL; 170 return -EINVAL; 171 } 172 173 /* 174 * Get real, policy values from mapped values 175 */ 176 177 static u16 unmap_class(struct selinux_map *map, u16 tclass) 178 { 179 if (tclass < map->size) 180 return map->mapping[tclass].value; 181 182 return tclass; 183 } 184 185 /* 186 * Get kernel value for class from its policy value 187 */ 188 static u16 map_class(struct selinux_map *map, u16 pol_value) 189 { 190 u16 i; 191 192 for (i = 1; i < map->size; i++) { 193 if (map->mapping[i].value == pol_value) 194 return i; 195 } 196 197 return SECCLASS_NULL; 198 } 199 200 static void map_decision(struct selinux_map *map, 201 u16 tclass, struct av_decision *avd, 202 int allow_unknown) 203 { 204 if (tclass < map->size) { 205 struct selinux_mapping *mapping = &map->mapping[tclass]; 206 unsigned int i, n = mapping->num_perms; 207 u32 result; 208 209 for (i = 0, result = 0; i < n; i++) { 210 if (avd->allowed & mapping->perms[i]) 211 result |= (u32)1<<i; 212 if (allow_unknown && !mapping->perms[i]) 213 result |= (u32)1<<i; 214 } 215 avd->allowed = result; 216 217 for (i = 0, result = 0; i < n; i++) 218 if (avd->auditallow & mapping->perms[i]) 219 result |= (u32)1<<i; 220 avd->auditallow = result; 221 222 for (i = 0, result = 0; i < n; i++) { 223 if (avd->auditdeny & mapping->perms[i]) 224 result |= (u32)1<<i; 225 if (!allow_unknown && !mapping->perms[i]) 226 result |= (u32)1<<i; 227 } 228 /* 229 * In case the kernel has a bug and requests a permission 230 * between num_perms and the maximum permission number, we 231 * should audit that denial 232 */ 233 for (; i < (sizeof(u32)*8); i++) 234 result |= (u32)1<<i; 235 avd->auditdeny = result; 236 } 237 } 238 239 int security_mls_enabled(void) 240 { 241 int mls_enabled; 242 struct selinux_policy *policy; 243 244 if (!selinux_initialized()) 245 return 0; 246 247 rcu_read_lock(); 248 policy = rcu_dereference(selinux_state.policy); 249 mls_enabled = policy->policydb.mls_enabled; 250 rcu_read_unlock(); 251 return mls_enabled; 252 } 253 254 /* 255 * Return the boolean value of a constraint expression 256 * when it is applied to the specified source and target 257 * security contexts. 258 * 259 * xcontext is a special beast... It is used by the validatetrans rules 260 * only. For these rules, scontext is the context before the transition, 261 * tcontext is the context after the transition, and xcontext is the context 262 * of the process performing the transition. All other callers of 263 * constraint_expr_eval should pass in NULL for xcontext. 264 */ 265 static int constraint_expr_eval(struct policydb *policydb, 266 struct context *scontext, 267 struct context *tcontext, 268 struct context *xcontext, 269 struct constraint_expr *cexpr) 270 { 271 u32 val1, val2; 272 struct context *c; 273 struct role_datum *r1, *r2; 274 struct mls_level *l1, *l2; 275 struct constraint_expr *e; 276 int s[CEXPR_MAXDEPTH]; 277 int sp = -1; 278 279 for (e = cexpr; e; e = e->next) { 280 switch (e->expr_type) { 281 case CEXPR_NOT: 282 BUG_ON(sp < 0); 283 s[sp] = !s[sp]; 284 break; 285 case CEXPR_AND: 286 BUG_ON(sp < 1); 287 sp--; 288 s[sp] &= s[sp + 1]; 289 break; 290 case CEXPR_OR: 291 BUG_ON(sp < 1); 292 sp--; 293 s[sp] |= s[sp + 1]; 294 break; 295 case CEXPR_ATTR: 296 if (sp == (CEXPR_MAXDEPTH - 1)) 297 return 0; 298 switch (e->attr) { 299 case CEXPR_USER: 300 val1 = scontext->user; 301 val2 = tcontext->user; 302 break; 303 case CEXPR_TYPE: 304 val1 = scontext->type; 305 val2 = tcontext->type; 306 break; 307 case CEXPR_ROLE: 308 val1 = scontext->role; 309 val2 = tcontext->role; 310 r1 = policydb->role_val_to_struct[val1 - 1]; 311 r2 = policydb->role_val_to_struct[val2 - 1]; 312 switch (e->op) { 313 case CEXPR_DOM: 314 s[++sp] = ebitmap_get_bit(&r1->dominates, 315 val2 - 1); 316 continue; 317 case CEXPR_DOMBY: 318 s[++sp] = ebitmap_get_bit(&r2->dominates, 319 val1 - 1); 320 continue; 321 case CEXPR_INCOMP: 322 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 323 val2 - 1) && 324 !ebitmap_get_bit(&r2->dominates, 325 val1 - 1)); 326 continue; 327 default: 328 break; 329 } 330 break; 331 case CEXPR_L1L2: 332 l1 = &(scontext->range.level[0]); 333 l2 = &(tcontext->range.level[0]); 334 goto mls_ops; 335 case CEXPR_L1H2: 336 l1 = &(scontext->range.level[0]); 337 l2 = &(tcontext->range.level[1]); 338 goto mls_ops; 339 case CEXPR_H1L2: 340 l1 = &(scontext->range.level[1]); 341 l2 = &(tcontext->range.level[0]); 342 goto mls_ops; 343 case CEXPR_H1H2: 344 l1 = &(scontext->range.level[1]); 345 l2 = &(tcontext->range.level[1]); 346 goto mls_ops; 347 case CEXPR_L1H1: 348 l1 = &(scontext->range.level[0]); 349 l2 = &(scontext->range.level[1]); 350 goto mls_ops; 351 case CEXPR_L2H2: 352 l1 = &(tcontext->range.level[0]); 353 l2 = &(tcontext->range.level[1]); 354 goto mls_ops; 355 mls_ops: 356 switch (e->op) { 357 case CEXPR_EQ: 358 s[++sp] = mls_level_eq(l1, l2); 359 continue; 360 case CEXPR_NEQ: 361 s[++sp] = !mls_level_eq(l1, l2); 362 continue; 363 case CEXPR_DOM: 364 s[++sp] = mls_level_dom(l1, l2); 365 continue; 366 case CEXPR_DOMBY: 367 s[++sp] = mls_level_dom(l2, l1); 368 continue; 369 case CEXPR_INCOMP: 370 s[++sp] = mls_level_incomp(l2, l1); 371 continue; 372 default: 373 BUG(); 374 return 0; 375 } 376 break; 377 default: 378 BUG(); 379 return 0; 380 } 381 382 switch (e->op) { 383 case CEXPR_EQ: 384 s[++sp] = (val1 == val2); 385 break; 386 case CEXPR_NEQ: 387 s[++sp] = (val1 != val2); 388 break; 389 default: 390 BUG(); 391 return 0; 392 } 393 break; 394 case CEXPR_NAMES: 395 if (sp == (CEXPR_MAXDEPTH-1)) 396 return 0; 397 c = scontext; 398 if (e->attr & CEXPR_TARGET) 399 c = tcontext; 400 else if (e->attr & CEXPR_XTARGET) { 401 c = xcontext; 402 if (!c) { 403 BUG(); 404 return 0; 405 } 406 } 407 if (e->attr & CEXPR_USER) 408 val1 = c->user; 409 else if (e->attr & CEXPR_ROLE) 410 val1 = c->role; 411 else if (e->attr & CEXPR_TYPE) 412 val1 = c->type; 413 else { 414 BUG(); 415 return 0; 416 } 417 418 switch (e->op) { 419 case CEXPR_EQ: 420 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 421 break; 422 case CEXPR_NEQ: 423 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 424 break; 425 default: 426 BUG(); 427 return 0; 428 } 429 break; 430 default: 431 BUG(); 432 return 0; 433 } 434 } 435 436 BUG_ON(sp != 0); 437 return s[0]; 438 } 439 440 /* 441 * security_dump_masked_av - dumps masked permissions during 442 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 443 */ 444 static int dump_masked_av_helper(void *k, void *d, void *args) 445 { 446 struct perm_datum *pdatum = d; 447 char **permission_names = args; 448 449 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 450 451 permission_names[pdatum->value - 1] = (char *)k; 452 453 return 0; 454 } 455 456 static void security_dump_masked_av(struct policydb *policydb, 457 struct context *scontext, 458 struct context *tcontext, 459 u16 tclass, 460 u32 permissions, 461 const char *reason) 462 { 463 struct common_datum *common_dat; 464 struct class_datum *tclass_dat; 465 struct audit_buffer *ab; 466 char *tclass_name; 467 char *scontext_name = NULL; 468 char *tcontext_name = NULL; 469 char *permission_names[32]; 470 int index; 471 u32 length; 472 bool need_comma = false; 473 474 if (!permissions) 475 return; 476 477 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); 478 tclass_dat = policydb->class_val_to_struct[tclass - 1]; 479 common_dat = tclass_dat->comdatum; 480 481 /* init permission_names */ 482 if (common_dat && 483 hashtab_map(&common_dat->permissions.table, 484 dump_masked_av_helper, permission_names) < 0) 485 goto out; 486 487 if (hashtab_map(&tclass_dat->permissions.table, 488 dump_masked_av_helper, permission_names) < 0) 489 goto out; 490 491 /* get scontext/tcontext in text form */ 492 if (context_struct_to_string(policydb, scontext, 493 &scontext_name, &length) < 0) 494 goto out; 495 496 if (context_struct_to_string(policydb, tcontext, 497 &tcontext_name, &length) < 0) 498 goto out; 499 500 /* audit a message */ 501 ab = audit_log_start(audit_context(), 502 GFP_ATOMIC, AUDIT_SELINUX_ERR); 503 if (!ab) 504 goto out; 505 506 audit_log_format(ab, "op=security_compute_av reason=%s " 507 "scontext=%s tcontext=%s tclass=%s perms=", 508 reason, scontext_name, tcontext_name, tclass_name); 509 510 for (index = 0; index < 32; index++) { 511 u32 mask = (1 << index); 512 513 if ((mask & permissions) == 0) 514 continue; 515 516 audit_log_format(ab, "%s%s", 517 need_comma ? "," : "", 518 permission_names[index] 519 ? permission_names[index] : "????"); 520 need_comma = true; 521 } 522 audit_log_end(ab); 523 out: 524 /* release scontext/tcontext */ 525 kfree(tcontext_name); 526 kfree(scontext_name); 527 } 528 529 /* 530 * security_boundary_permission - drops violated permissions 531 * on boundary constraint. 532 */ 533 static void type_attribute_bounds_av(struct policydb *policydb, 534 struct context *scontext, 535 struct context *tcontext, 536 u16 tclass, 537 struct av_decision *avd) 538 { 539 struct context lo_scontext; 540 struct context lo_tcontext, *tcontextp = tcontext; 541 struct av_decision lo_avd; 542 struct type_datum *source; 543 struct type_datum *target; 544 u32 masked = 0; 545 546 source = policydb->type_val_to_struct[scontext->type - 1]; 547 BUG_ON(!source); 548 549 if (!source->bounds) 550 return; 551 552 target = policydb->type_val_to_struct[tcontext->type - 1]; 553 BUG_ON(!target); 554 555 memset(&lo_avd, 0, sizeof(lo_avd)); 556 557 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 558 lo_scontext.type = source->bounds; 559 560 if (target->bounds) { 561 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 562 lo_tcontext.type = target->bounds; 563 tcontextp = &lo_tcontext; 564 } 565 566 context_struct_compute_av(policydb, &lo_scontext, 567 tcontextp, 568 tclass, 569 &lo_avd, 570 NULL); 571 572 masked = ~lo_avd.allowed & avd->allowed; 573 574 if (likely(!masked)) 575 return; /* no masked permission */ 576 577 /* mask violated permissions */ 578 avd->allowed &= ~masked; 579 580 /* audit masked permissions */ 581 security_dump_masked_av(policydb, scontext, tcontext, 582 tclass, masked, "bounds"); 583 } 584 585 /* 586 * Flag which drivers have permissions and which base permissions are covered. 587 */ 588 void services_compute_xperms_drivers( 589 struct extended_perms *xperms, 590 struct avtab_node *node) 591 { 592 unsigned int i; 593 594 switch (node->datum.u.xperms->specified) { 595 case AVTAB_XPERMS_IOCTLDRIVER: 596 xperms->base_perms |= AVC_EXT_IOCTL; 597 /* if one or more driver has all permissions allowed */ 598 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 599 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 600 break; 601 case AVTAB_XPERMS_IOCTLFUNCTION: 602 xperms->base_perms |= AVC_EXT_IOCTL; 603 /* if allowing permissions within a driver */ 604 security_xperm_set(xperms->drivers.p, 605 node->datum.u.xperms->driver); 606 break; 607 case AVTAB_XPERMS_NLMSG: 608 xperms->base_perms |= AVC_EXT_NLMSG; 609 /* if allowing permissions within a driver */ 610 security_xperm_set(xperms->drivers.p, 611 node->datum.u.xperms->driver); 612 break; 613 } 614 615 xperms->len = 1; 616 } 617 618 /* 619 * Compute access vectors and extended permissions based on a context 620 * structure pair for the permissions in a particular class. 621 */ 622 static void context_struct_compute_av(struct policydb *policydb, 623 struct context *scontext, 624 struct context *tcontext, 625 u16 tclass, 626 struct av_decision *avd, 627 struct extended_perms *xperms) 628 { 629 struct constraint_node *constraint; 630 struct role_allow *ra; 631 struct avtab_key avkey; 632 struct avtab_node *node; 633 struct class_datum *tclass_datum; 634 struct ebitmap *sattr, *tattr; 635 struct ebitmap_node *snode, *tnode; 636 unsigned int i, j; 637 638 avd->allowed = 0; 639 avd->auditallow = 0; 640 avd->auditdeny = 0xffffffff; 641 if (xperms) { 642 memset(xperms, 0, sizeof(*xperms)); 643 } 644 645 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 646 pr_warn_ratelimited("SELinux: Invalid class %u\n", tclass); 647 return; 648 } 649 650 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 651 652 /* 653 * If a specific type enforcement rule was defined for 654 * this permission check, then use it. 655 */ 656 avkey.target_class = tclass; 657 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 658 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 659 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 660 ebitmap_for_each_positive_bit(sattr, snode, i) { 661 ebitmap_for_each_positive_bit(tattr, tnode, j) { 662 avkey.source_type = i + 1; 663 avkey.target_type = j + 1; 664 for (node = avtab_search_node(&policydb->te_avtab, 665 &avkey); 666 node; 667 node = avtab_search_node_next(node, avkey.specified)) { 668 if (node->key.specified == AVTAB_ALLOWED) 669 avd->allowed |= node->datum.u.data; 670 else if (node->key.specified == AVTAB_AUDITALLOW) 671 avd->auditallow |= node->datum.u.data; 672 else if (node->key.specified == AVTAB_AUDITDENY) 673 avd->auditdeny &= node->datum.u.data; 674 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 675 services_compute_xperms_drivers(xperms, node); 676 } 677 678 /* Check conditional av table for additional permissions */ 679 cond_compute_av(&policydb->te_cond_avtab, &avkey, 680 avd, xperms); 681 682 } 683 } 684 685 /* 686 * Remove any permissions prohibited by a constraint (this includes 687 * the MLS policy). 688 */ 689 constraint = tclass_datum->constraints; 690 while (constraint) { 691 if ((constraint->permissions & (avd->allowed)) && 692 !constraint_expr_eval(policydb, scontext, tcontext, NULL, 693 constraint->expr)) { 694 avd->allowed &= ~(constraint->permissions); 695 } 696 constraint = constraint->next; 697 } 698 699 /* 700 * If checking process transition permission and the 701 * role is changing, then check the (current_role, new_role) 702 * pair. 703 */ 704 if (tclass == policydb->process_class && 705 (avd->allowed & policydb->process_trans_perms) && 706 scontext->role != tcontext->role) { 707 for (ra = policydb->role_allow; ra; ra = ra->next) { 708 if (scontext->role == ra->role && 709 tcontext->role == ra->new_role) 710 break; 711 } 712 if (!ra) 713 avd->allowed &= ~policydb->process_trans_perms; 714 } 715 716 /* 717 * If the given source and target types have boundary 718 * constraint, lazy checks have to mask any violated 719 * permission and notice it to userspace via audit. 720 */ 721 type_attribute_bounds_av(policydb, scontext, tcontext, 722 tclass, avd); 723 } 724 725 static int security_validtrans_handle_fail(struct selinux_policy *policy, 726 struct sidtab_entry *oentry, 727 struct sidtab_entry *nentry, 728 struct sidtab_entry *tentry, 729 u16 tclass) 730 { 731 struct policydb *p = &policy->policydb; 732 struct sidtab *sidtab = policy->sidtab; 733 char *o = NULL, *n = NULL, *t = NULL; 734 u32 olen, nlen, tlen; 735 736 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) 737 goto out; 738 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) 739 goto out; 740 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) 741 goto out; 742 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 743 "op=security_validate_transition seresult=denied" 744 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 745 o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); 746 out: 747 kfree(o); 748 kfree(n); 749 kfree(t); 750 751 if (!enforcing_enabled()) 752 return 0; 753 return -EPERM; 754 } 755 756 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid, 757 u16 orig_tclass, bool user) 758 { 759 struct selinux_policy *policy; 760 struct policydb *policydb; 761 struct sidtab *sidtab; 762 struct sidtab_entry *oentry; 763 struct sidtab_entry *nentry; 764 struct sidtab_entry *tentry; 765 struct class_datum *tclass_datum; 766 struct constraint_node *constraint; 767 u16 tclass; 768 int rc = 0; 769 770 771 if (!selinux_initialized()) 772 return 0; 773 774 rcu_read_lock(); 775 776 policy = rcu_dereference(selinux_state.policy); 777 policydb = &policy->policydb; 778 sidtab = policy->sidtab; 779 780 if (!user) 781 tclass = unmap_class(&policy->map, orig_tclass); 782 else 783 tclass = orig_tclass; 784 785 if (!tclass || tclass > policydb->p_classes.nprim) { 786 rc = -EINVAL; 787 goto out; 788 } 789 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 790 791 oentry = sidtab_search_entry(sidtab, oldsid); 792 if (!oentry) { 793 pr_err("SELinux: %s: unrecognized SID %d\n", 794 __func__, oldsid); 795 rc = -EINVAL; 796 goto out; 797 } 798 799 nentry = sidtab_search_entry(sidtab, newsid); 800 if (!nentry) { 801 pr_err("SELinux: %s: unrecognized SID %d\n", 802 __func__, newsid); 803 rc = -EINVAL; 804 goto out; 805 } 806 807 tentry = sidtab_search_entry(sidtab, tasksid); 808 if (!tentry) { 809 pr_err("SELinux: %s: unrecognized SID %d\n", 810 __func__, tasksid); 811 rc = -EINVAL; 812 goto out; 813 } 814 815 constraint = tclass_datum->validatetrans; 816 while (constraint) { 817 if (!constraint_expr_eval(policydb, &oentry->context, 818 &nentry->context, &tentry->context, 819 constraint->expr)) { 820 if (user) 821 rc = -EPERM; 822 else 823 rc = security_validtrans_handle_fail(policy, 824 oentry, 825 nentry, 826 tentry, 827 tclass); 828 goto out; 829 } 830 constraint = constraint->next; 831 } 832 833 out: 834 rcu_read_unlock(); 835 return rc; 836 } 837 838 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, 839 u16 tclass) 840 { 841 return security_compute_validatetrans(oldsid, newsid, tasksid, 842 tclass, true); 843 } 844 845 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 846 u16 orig_tclass) 847 { 848 return security_compute_validatetrans(oldsid, newsid, tasksid, 849 orig_tclass, false); 850 } 851 852 /* 853 * security_bounded_transition - check whether the given 854 * transition is directed to bounded, or not. 855 * It returns 0, if @newsid is bounded by @oldsid. 856 * Otherwise, it returns error code. 857 * 858 * @oldsid : current security identifier 859 * @newsid : destinated security identifier 860 */ 861 int security_bounded_transition(u32 old_sid, u32 new_sid) 862 { 863 struct selinux_policy *policy; 864 struct policydb *policydb; 865 struct sidtab *sidtab; 866 struct sidtab_entry *old_entry, *new_entry; 867 struct type_datum *type; 868 u32 index; 869 int rc; 870 871 if (!selinux_initialized()) 872 return 0; 873 874 rcu_read_lock(); 875 policy = rcu_dereference(selinux_state.policy); 876 policydb = &policy->policydb; 877 sidtab = policy->sidtab; 878 879 rc = -EINVAL; 880 old_entry = sidtab_search_entry(sidtab, old_sid); 881 if (!old_entry) { 882 pr_err("SELinux: %s: unrecognized SID %u\n", 883 __func__, old_sid); 884 goto out; 885 } 886 887 rc = -EINVAL; 888 new_entry = sidtab_search_entry(sidtab, new_sid); 889 if (!new_entry) { 890 pr_err("SELinux: %s: unrecognized SID %u\n", 891 __func__, new_sid); 892 goto out; 893 } 894 895 rc = 0; 896 /* type/domain unchanged */ 897 if (old_entry->context.type == new_entry->context.type) 898 goto out; 899 900 index = new_entry->context.type; 901 while (true) { 902 type = policydb->type_val_to_struct[index - 1]; 903 BUG_ON(!type); 904 905 /* not bounded anymore */ 906 rc = -EPERM; 907 if (!type->bounds) 908 break; 909 910 /* @newsid is bounded by @oldsid */ 911 rc = 0; 912 if (type->bounds == old_entry->context.type) 913 break; 914 915 index = type->bounds; 916 } 917 918 if (rc) { 919 char *old_name = NULL; 920 char *new_name = NULL; 921 u32 length; 922 923 if (!sidtab_entry_to_string(policydb, sidtab, old_entry, 924 &old_name, &length) && 925 !sidtab_entry_to_string(policydb, sidtab, new_entry, 926 &new_name, &length)) { 927 audit_log(audit_context(), 928 GFP_ATOMIC, AUDIT_SELINUX_ERR, 929 "op=security_bounded_transition " 930 "seresult=denied " 931 "oldcontext=%s newcontext=%s", 932 old_name, new_name); 933 } 934 kfree(new_name); 935 kfree(old_name); 936 } 937 out: 938 rcu_read_unlock(); 939 940 return rc; 941 } 942 943 static void avd_init(struct selinux_policy *policy, struct av_decision *avd) 944 { 945 avd->allowed = 0; 946 avd->auditallow = 0; 947 avd->auditdeny = 0xffffffff; 948 if (policy) 949 avd->seqno = policy->latest_granting; 950 else 951 avd->seqno = 0; 952 avd->flags = 0; 953 } 954 955 static void update_xperms_extended_data(u8 specified, 956 const struct extended_perms_data *from, 957 struct extended_perms_data *xp_data) 958 { 959 unsigned int i; 960 961 switch (specified) { 962 case AVTAB_XPERMS_IOCTLDRIVER: 963 memset(xp_data->p, 0xff, sizeof(xp_data->p)); 964 break; 965 case AVTAB_XPERMS_IOCTLFUNCTION: 966 case AVTAB_XPERMS_NLMSG: 967 for (i = 0; i < ARRAY_SIZE(xp_data->p); i++) 968 xp_data->p[i] |= from->p[i]; 969 break; 970 } 971 972 } 973 974 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 975 struct avtab_node *node) 976 { 977 u16 specified; 978 979 switch (node->datum.u.xperms->specified) { 980 case AVTAB_XPERMS_IOCTLFUNCTION: 981 if (xpermd->base_perm != AVC_EXT_IOCTL || 982 xpermd->driver != node->datum.u.xperms->driver) 983 return; 984 break; 985 case AVTAB_XPERMS_IOCTLDRIVER: 986 if (xpermd->base_perm != AVC_EXT_IOCTL || 987 !security_xperm_test(node->datum.u.xperms->perms.p, 988 xpermd->driver)) 989 return; 990 break; 991 case AVTAB_XPERMS_NLMSG: 992 if (xpermd->base_perm != AVC_EXT_NLMSG || 993 xpermd->driver != node->datum.u.xperms->driver) 994 return; 995 break; 996 default: 997 pr_warn_once( 998 "SELinux: unknown extended permission (%u) will be ignored\n", 999 node->datum.u.xperms->specified); 1000 return; 1001 } 1002 1003 specified = node->key.specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); 1004 1005 if (specified == AVTAB_XPERMS_ALLOWED) { 1006 xpermd->used |= XPERMS_ALLOWED; 1007 update_xperms_extended_data(node->datum.u.xperms->specified, 1008 &node->datum.u.xperms->perms, 1009 xpermd->allowed); 1010 } else if (specified == AVTAB_XPERMS_AUDITALLOW) { 1011 xpermd->used |= XPERMS_AUDITALLOW; 1012 update_xperms_extended_data(node->datum.u.xperms->specified, 1013 &node->datum.u.xperms->perms, 1014 xpermd->auditallow); 1015 } else if (specified == AVTAB_XPERMS_DONTAUDIT) { 1016 xpermd->used |= XPERMS_DONTAUDIT; 1017 update_xperms_extended_data(node->datum.u.xperms->specified, 1018 &node->datum.u.xperms->perms, 1019 xpermd->dontaudit); 1020 } else { 1021 pr_warn_once("SELinux: unknown specified key (%u)\n", 1022 node->key.specified); 1023 } 1024 } 1025 1026 void security_compute_xperms_decision(u32 ssid, 1027 u32 tsid, 1028 u16 orig_tclass, 1029 u8 driver, 1030 u8 base_perm, 1031 struct extended_perms_decision *xpermd) 1032 { 1033 struct selinux_policy *policy; 1034 struct policydb *policydb; 1035 struct sidtab *sidtab; 1036 u16 tclass; 1037 struct context *scontext, *tcontext; 1038 struct avtab_key avkey; 1039 struct avtab_node *node; 1040 struct ebitmap *sattr, *tattr; 1041 struct ebitmap_node *snode, *tnode; 1042 unsigned int i, j; 1043 1044 xpermd->base_perm = base_perm; 1045 xpermd->driver = driver; 1046 xpermd->used = 0; 1047 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1048 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1049 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1050 1051 rcu_read_lock(); 1052 if (!selinux_initialized()) 1053 goto allow; 1054 1055 policy = rcu_dereference(selinux_state.policy); 1056 policydb = &policy->policydb; 1057 sidtab = policy->sidtab; 1058 1059 scontext = sidtab_search(sidtab, ssid); 1060 if (!scontext) { 1061 pr_err("SELinux: %s: unrecognized SID %d\n", 1062 __func__, ssid); 1063 goto out; 1064 } 1065 1066 tcontext = sidtab_search(sidtab, tsid); 1067 if (!tcontext) { 1068 pr_err("SELinux: %s: unrecognized SID %d\n", 1069 __func__, tsid); 1070 goto out; 1071 } 1072 1073 tclass = unmap_class(&policy->map, orig_tclass); 1074 if (unlikely(orig_tclass && !tclass)) { 1075 if (policydb->allow_unknown) 1076 goto allow; 1077 goto out; 1078 } 1079 1080 1081 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1082 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1083 goto out; 1084 } 1085 1086 avkey.target_class = tclass; 1087 avkey.specified = AVTAB_XPERMS; 1088 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 1089 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 1090 ebitmap_for_each_positive_bit(sattr, snode, i) { 1091 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1092 avkey.source_type = i + 1; 1093 avkey.target_type = j + 1; 1094 for (node = avtab_search_node(&policydb->te_avtab, 1095 &avkey); 1096 node; 1097 node = avtab_search_node_next(node, avkey.specified)) 1098 services_compute_xperms_decision(xpermd, node); 1099 1100 cond_compute_xperms(&policydb->te_cond_avtab, 1101 &avkey, xpermd); 1102 } 1103 } 1104 out: 1105 rcu_read_unlock(); 1106 return; 1107 allow: 1108 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1109 goto out; 1110 } 1111 1112 /** 1113 * security_compute_av - Compute access vector decisions. 1114 * @ssid: source security identifier 1115 * @tsid: target security identifier 1116 * @orig_tclass: target security class 1117 * @avd: access vector decisions 1118 * @xperms: extended permissions 1119 * 1120 * Compute a set of access vector decisions based on the 1121 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1122 */ 1123 void security_compute_av(u32 ssid, 1124 u32 tsid, 1125 u16 orig_tclass, 1126 struct av_decision *avd, 1127 struct extended_perms *xperms) 1128 { 1129 struct selinux_policy *policy; 1130 struct policydb *policydb; 1131 struct sidtab *sidtab; 1132 u16 tclass; 1133 struct context *scontext = NULL, *tcontext = NULL; 1134 1135 rcu_read_lock(); 1136 policy = rcu_dereference(selinux_state.policy); 1137 avd_init(policy, avd); 1138 xperms->len = 0; 1139 if (!selinux_initialized()) 1140 goto allow; 1141 1142 policydb = &policy->policydb; 1143 sidtab = policy->sidtab; 1144 1145 scontext = sidtab_search(sidtab, ssid); 1146 if (!scontext) { 1147 pr_err("SELinux: %s: unrecognized SID %d\n", 1148 __func__, ssid); 1149 goto out; 1150 } 1151 1152 /* permissive domain? */ 1153 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1154 avd->flags |= AVD_FLAGS_PERMISSIVE; 1155 1156 tcontext = sidtab_search(sidtab, tsid); 1157 if (!tcontext) { 1158 pr_err("SELinux: %s: unrecognized SID %d\n", 1159 __func__, tsid); 1160 goto out; 1161 } 1162 1163 tclass = unmap_class(&policy->map, orig_tclass); 1164 if (unlikely(orig_tclass && !tclass)) { 1165 if (policydb->allow_unknown) 1166 goto allow; 1167 goto out; 1168 } 1169 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1170 xperms); 1171 map_decision(&policy->map, orig_tclass, avd, 1172 policydb->allow_unknown); 1173 out: 1174 rcu_read_unlock(); 1175 return; 1176 allow: 1177 avd->allowed = 0xffffffff; 1178 goto out; 1179 } 1180 1181 void security_compute_av_user(u32 ssid, 1182 u32 tsid, 1183 u16 tclass, 1184 struct av_decision *avd) 1185 { 1186 struct selinux_policy *policy; 1187 struct policydb *policydb; 1188 struct sidtab *sidtab; 1189 struct context *scontext = NULL, *tcontext = NULL; 1190 1191 rcu_read_lock(); 1192 policy = rcu_dereference(selinux_state.policy); 1193 avd_init(policy, avd); 1194 if (!selinux_initialized()) 1195 goto allow; 1196 1197 policydb = &policy->policydb; 1198 sidtab = policy->sidtab; 1199 1200 scontext = sidtab_search(sidtab, ssid); 1201 if (!scontext) { 1202 pr_err("SELinux: %s: unrecognized SID %d\n", 1203 __func__, ssid); 1204 goto out; 1205 } 1206 1207 /* permissive domain? */ 1208 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1209 avd->flags |= AVD_FLAGS_PERMISSIVE; 1210 1211 tcontext = sidtab_search(sidtab, tsid); 1212 if (!tcontext) { 1213 pr_err("SELinux: %s: unrecognized SID %d\n", 1214 __func__, tsid); 1215 goto out; 1216 } 1217 1218 if (unlikely(!tclass)) { 1219 if (policydb->allow_unknown) 1220 goto allow; 1221 goto out; 1222 } 1223 1224 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1225 NULL); 1226 out: 1227 rcu_read_unlock(); 1228 return; 1229 allow: 1230 avd->allowed = 0xffffffff; 1231 goto out; 1232 } 1233 1234 /* 1235 * Write the security context string representation of 1236 * the context structure `context' into a dynamically 1237 * allocated string of the correct size. Set `*scontext' 1238 * to point to this string and set `*scontext_len' to 1239 * the length of the string. 1240 */ 1241 static int context_struct_to_string(struct policydb *p, 1242 struct context *context, 1243 char **scontext, u32 *scontext_len) 1244 { 1245 char *scontextp; 1246 1247 if (scontext) 1248 *scontext = NULL; 1249 *scontext_len = 0; 1250 1251 if (context->len) { 1252 *scontext_len = context->len; 1253 if (scontext) { 1254 *scontext = kstrdup(context->str, GFP_ATOMIC); 1255 if (!(*scontext)) 1256 return -ENOMEM; 1257 } 1258 return 0; 1259 } 1260 1261 /* Compute the size of the context. */ 1262 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1263 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1264 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1265 *scontext_len += mls_compute_context_len(p, context); 1266 1267 if (!scontext) 1268 return 0; 1269 1270 /* Allocate space for the context; caller must free this space. */ 1271 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1272 if (!scontextp) 1273 return -ENOMEM; 1274 *scontext = scontextp; 1275 1276 /* 1277 * Copy the user name, role name and type name into the context. 1278 */ 1279 scontextp += sprintf(scontextp, "%s:%s:%s", 1280 sym_name(p, SYM_USERS, context->user - 1), 1281 sym_name(p, SYM_ROLES, context->role - 1), 1282 sym_name(p, SYM_TYPES, context->type - 1)); 1283 1284 mls_sid_to_context(p, context, &scontextp); 1285 1286 *scontextp = 0; 1287 1288 return 0; 1289 } 1290 1291 static int sidtab_entry_to_string(struct policydb *p, 1292 struct sidtab *sidtab, 1293 struct sidtab_entry *entry, 1294 char **scontext, u32 *scontext_len) 1295 { 1296 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); 1297 1298 if (rc != -ENOENT) 1299 return rc; 1300 1301 rc = context_struct_to_string(p, &entry->context, scontext, 1302 scontext_len); 1303 if (!rc && scontext) 1304 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); 1305 return rc; 1306 } 1307 1308 #include "initial_sid_to_string.h" 1309 1310 int security_sidtab_hash_stats(char *page) 1311 { 1312 struct selinux_policy *policy; 1313 int rc; 1314 1315 if (!selinux_initialized()) { 1316 pr_err("SELinux: %s: called before initial load_policy\n", 1317 __func__); 1318 return -EINVAL; 1319 } 1320 1321 rcu_read_lock(); 1322 policy = rcu_dereference(selinux_state.policy); 1323 rc = sidtab_hash_stats(policy->sidtab, page); 1324 rcu_read_unlock(); 1325 1326 return rc; 1327 } 1328 1329 const char *security_get_initial_sid_context(u32 sid) 1330 { 1331 if (unlikely(sid > SECINITSID_NUM)) 1332 return NULL; 1333 return initial_sid_to_string[sid]; 1334 } 1335 1336 static int security_sid_to_context_core(u32 sid, char **scontext, 1337 u32 *scontext_len, int force, 1338 int only_invalid) 1339 { 1340 struct selinux_policy *policy; 1341 struct policydb *policydb; 1342 struct sidtab *sidtab; 1343 struct sidtab_entry *entry; 1344 int rc = 0; 1345 1346 if (scontext) 1347 *scontext = NULL; 1348 *scontext_len = 0; 1349 1350 if (!selinux_initialized()) { 1351 if (sid <= SECINITSID_NUM) { 1352 char *scontextp; 1353 const char *s; 1354 1355 /* 1356 * Before the policy is loaded, translate 1357 * SECINITSID_INIT to "kernel", because systemd and 1358 * libselinux < 2.6 take a getcon_raw() result that is 1359 * both non-null and not "kernel" to mean that a policy 1360 * is already loaded. 1361 */ 1362 if (sid == SECINITSID_INIT) 1363 sid = SECINITSID_KERNEL; 1364 1365 s = initial_sid_to_string[sid]; 1366 if (!s) 1367 return -EINVAL; 1368 *scontext_len = strlen(s) + 1; 1369 if (!scontext) 1370 return 0; 1371 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1372 if (!scontextp) 1373 return -ENOMEM; 1374 *scontext = scontextp; 1375 return 0; 1376 } 1377 pr_err("SELinux: %s: called before initial " 1378 "load_policy on unknown SID %d\n", __func__, sid); 1379 return -EINVAL; 1380 } 1381 rcu_read_lock(); 1382 policy = rcu_dereference(selinux_state.policy); 1383 policydb = &policy->policydb; 1384 sidtab = policy->sidtab; 1385 1386 if (force) 1387 entry = sidtab_search_entry_force(sidtab, sid); 1388 else 1389 entry = sidtab_search_entry(sidtab, sid); 1390 if (!entry) { 1391 pr_err("SELinux: %s: unrecognized SID %d\n", 1392 __func__, sid); 1393 rc = -EINVAL; 1394 goto out_unlock; 1395 } 1396 if (only_invalid && !entry->context.len) 1397 goto out_unlock; 1398 1399 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1400 scontext_len); 1401 1402 out_unlock: 1403 rcu_read_unlock(); 1404 return rc; 1405 1406 } 1407 1408 /** 1409 * security_sid_to_context - Obtain a context for a given SID. 1410 * @sid: security identifier, SID 1411 * @scontext: security context 1412 * @scontext_len: length in bytes 1413 * 1414 * Write the string representation of the context associated with @sid 1415 * into a dynamically allocated string of the correct size. Set @scontext 1416 * to point to this string and set @scontext_len to the length of the string. 1417 */ 1418 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1419 { 1420 return security_sid_to_context_core(sid, scontext, 1421 scontext_len, 0, 0); 1422 } 1423 1424 int security_sid_to_context_force(u32 sid, 1425 char **scontext, u32 *scontext_len) 1426 { 1427 return security_sid_to_context_core(sid, scontext, 1428 scontext_len, 1, 0); 1429 } 1430 1431 /** 1432 * security_sid_to_context_inval - Obtain a context for a given SID if it 1433 * is invalid. 1434 * @sid: security identifier, SID 1435 * @scontext: security context 1436 * @scontext_len: length in bytes 1437 * 1438 * Write the string representation of the context associated with @sid 1439 * into a dynamically allocated string of the correct size, but only if the 1440 * context is invalid in the current policy. Set @scontext to point to 1441 * this string (or NULL if the context is valid) and set @scontext_len to 1442 * the length of the string (or 0 if the context is valid). 1443 */ 1444 int security_sid_to_context_inval(u32 sid, 1445 char **scontext, u32 *scontext_len) 1446 { 1447 return security_sid_to_context_core(sid, scontext, 1448 scontext_len, 1, 1); 1449 } 1450 1451 /* 1452 * Caveat: Mutates scontext. 1453 */ 1454 static int string_to_context_struct(struct policydb *pol, 1455 struct sidtab *sidtabp, 1456 char *scontext, 1457 struct context *ctx, 1458 u32 def_sid) 1459 { 1460 struct role_datum *role; 1461 struct type_datum *typdatum; 1462 struct user_datum *usrdatum; 1463 char *scontextp, *p, oldc; 1464 int rc = 0; 1465 1466 context_init(ctx); 1467 1468 /* Parse the security context. */ 1469 1470 rc = -EINVAL; 1471 scontextp = scontext; 1472 1473 /* Extract the user. */ 1474 p = scontextp; 1475 while (*p && *p != ':') 1476 p++; 1477 1478 if (*p == 0) 1479 goto out; 1480 1481 *p++ = 0; 1482 1483 usrdatum = symtab_search(&pol->p_users, scontextp); 1484 if (!usrdatum) 1485 goto out; 1486 1487 ctx->user = usrdatum->value; 1488 1489 /* Extract role. */ 1490 scontextp = p; 1491 while (*p && *p != ':') 1492 p++; 1493 1494 if (*p == 0) 1495 goto out; 1496 1497 *p++ = 0; 1498 1499 role = symtab_search(&pol->p_roles, scontextp); 1500 if (!role) 1501 goto out; 1502 ctx->role = role->value; 1503 1504 /* Extract type. */ 1505 scontextp = p; 1506 while (*p && *p != ':') 1507 p++; 1508 oldc = *p; 1509 *p++ = 0; 1510 1511 typdatum = symtab_search(&pol->p_types, scontextp); 1512 if (!typdatum || typdatum->attribute) 1513 goto out; 1514 1515 ctx->type = typdatum->value; 1516 1517 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1518 if (rc) 1519 goto out; 1520 1521 /* Check the validity of the new context. */ 1522 rc = -EINVAL; 1523 if (!policydb_context_isvalid(pol, ctx)) 1524 goto out; 1525 rc = 0; 1526 out: 1527 if (rc) 1528 context_destroy(ctx); 1529 return rc; 1530 } 1531 1532 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1533 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1534 int force) 1535 { 1536 struct selinux_policy *policy; 1537 struct policydb *policydb; 1538 struct sidtab *sidtab; 1539 char *scontext2, *str = NULL; 1540 struct context context; 1541 int rc = 0; 1542 1543 /* An empty security context is never valid. */ 1544 if (!scontext_len) 1545 return -EINVAL; 1546 1547 /* Copy the string to allow changes and ensure a NUL terminator */ 1548 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1549 if (!scontext2) 1550 return -ENOMEM; 1551 1552 if (!selinux_initialized()) { 1553 u32 i; 1554 1555 for (i = 1; i < SECINITSID_NUM; i++) { 1556 const char *s = initial_sid_to_string[i]; 1557 1558 if (s && !strcmp(s, scontext2)) { 1559 *sid = i; 1560 goto out; 1561 } 1562 } 1563 *sid = SECINITSID_KERNEL; 1564 goto out; 1565 } 1566 *sid = SECSID_NULL; 1567 1568 if (force) { 1569 /* Save another copy for storing in uninterpreted form */ 1570 rc = -ENOMEM; 1571 str = kstrdup(scontext2, gfp_flags); 1572 if (!str) 1573 goto out; 1574 } 1575 retry: 1576 rcu_read_lock(); 1577 policy = rcu_dereference(selinux_state.policy); 1578 policydb = &policy->policydb; 1579 sidtab = policy->sidtab; 1580 rc = string_to_context_struct(policydb, sidtab, scontext2, 1581 &context, def_sid); 1582 if (rc == -EINVAL && force) { 1583 context.str = str; 1584 context.len = strlen(str) + 1; 1585 str = NULL; 1586 } else if (rc) 1587 goto out_unlock; 1588 rc = sidtab_context_to_sid(sidtab, &context, sid); 1589 if (rc == -ESTALE) { 1590 rcu_read_unlock(); 1591 if (context.str) { 1592 str = context.str; 1593 context.str = NULL; 1594 } 1595 context_destroy(&context); 1596 goto retry; 1597 } 1598 context_destroy(&context); 1599 out_unlock: 1600 rcu_read_unlock(); 1601 out: 1602 kfree(scontext2); 1603 kfree(str); 1604 return rc; 1605 } 1606 1607 /** 1608 * security_context_to_sid - Obtain a SID for a given security context. 1609 * @scontext: security context 1610 * @scontext_len: length in bytes 1611 * @sid: security identifier, SID 1612 * @gfp: context for the allocation 1613 * 1614 * Obtains a SID associated with the security context that 1615 * has the string representation specified by @scontext. 1616 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1617 * memory is available, or 0 on success. 1618 */ 1619 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1620 gfp_t gfp) 1621 { 1622 return security_context_to_sid_core(scontext, scontext_len, 1623 sid, SECSID_NULL, gfp, 0); 1624 } 1625 1626 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1627 { 1628 return security_context_to_sid(scontext, strlen(scontext), 1629 sid, gfp); 1630 } 1631 1632 /** 1633 * security_context_to_sid_default - Obtain a SID for a given security context, 1634 * falling back to specified default if needed. 1635 * 1636 * @scontext: security context 1637 * @scontext_len: length in bytes 1638 * @sid: security identifier, SID 1639 * @def_sid: default SID to assign on error 1640 * @gfp_flags: the allocator get-free-page (GFP) flags 1641 * 1642 * Obtains a SID associated with the security context that 1643 * has the string representation specified by @scontext. 1644 * The default SID is passed to the MLS layer to be used to allow 1645 * kernel labeling of the MLS field if the MLS field is not present 1646 * (for upgrading to MLS without full relabel). 1647 * Implicitly forces adding of the context even if it cannot be mapped yet. 1648 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1649 * memory is available, or 0 on success. 1650 */ 1651 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1652 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1653 { 1654 return security_context_to_sid_core(scontext, scontext_len, 1655 sid, def_sid, gfp_flags, 1); 1656 } 1657 1658 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1659 u32 *sid) 1660 { 1661 return security_context_to_sid_core(scontext, scontext_len, 1662 sid, SECSID_NULL, GFP_KERNEL, 1); 1663 } 1664 1665 static int compute_sid_handle_invalid_context( 1666 struct selinux_policy *policy, 1667 struct sidtab_entry *sentry, 1668 struct sidtab_entry *tentry, 1669 u16 tclass, 1670 struct context *newcontext) 1671 { 1672 struct policydb *policydb = &policy->policydb; 1673 struct sidtab *sidtab = policy->sidtab; 1674 char *s = NULL, *t = NULL, *n = NULL; 1675 u32 slen, tlen, nlen; 1676 struct audit_buffer *ab; 1677 1678 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) 1679 goto out; 1680 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) 1681 goto out; 1682 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1683 goto out; 1684 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); 1685 if (!ab) 1686 goto out; 1687 audit_log_format(ab, 1688 "op=security_compute_sid invalid_context="); 1689 /* no need to record the NUL with untrusted strings */ 1690 audit_log_n_untrustedstring(ab, n, nlen - 1); 1691 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1692 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1693 audit_log_end(ab); 1694 out: 1695 kfree(s); 1696 kfree(t); 1697 kfree(n); 1698 if (!enforcing_enabled()) 1699 return 0; 1700 return -EACCES; 1701 } 1702 1703 static void filename_compute_type(struct policydb *policydb, 1704 struct context *newcontext, 1705 u32 stype, u32 ttype, u16 tclass, 1706 const char *objname) 1707 { 1708 struct filename_trans_key ft; 1709 struct filename_trans_datum *datum; 1710 1711 /* 1712 * Most filename trans rules are going to live in specific directories 1713 * like /dev or /var/run. This bitmap will quickly skip rule searches 1714 * if the ttype does not contain any rules. 1715 */ 1716 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1717 return; 1718 1719 ft.ttype = ttype; 1720 ft.tclass = tclass; 1721 ft.name = objname; 1722 1723 datum = policydb_filenametr_search(policydb, &ft); 1724 while (datum) { 1725 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1726 newcontext->type = datum->otype; 1727 return; 1728 } 1729 datum = datum->next; 1730 } 1731 } 1732 1733 static int security_compute_sid(u32 ssid, 1734 u32 tsid, 1735 u16 orig_tclass, 1736 u16 specified, 1737 const char *objname, 1738 u32 *out_sid, 1739 bool kern) 1740 { 1741 struct selinux_policy *policy; 1742 struct policydb *policydb; 1743 struct sidtab *sidtab; 1744 struct class_datum *cladatum; 1745 struct context *scontext, *tcontext, newcontext; 1746 struct sidtab_entry *sentry, *tentry; 1747 struct avtab_key avkey; 1748 struct avtab_node *avnode, *node; 1749 u16 tclass; 1750 int rc = 0; 1751 bool sock; 1752 1753 if (!selinux_initialized()) { 1754 switch (orig_tclass) { 1755 case SECCLASS_PROCESS: /* kernel value */ 1756 *out_sid = ssid; 1757 break; 1758 default: 1759 *out_sid = tsid; 1760 break; 1761 } 1762 goto out; 1763 } 1764 1765 retry: 1766 cladatum = NULL; 1767 context_init(&newcontext); 1768 1769 rcu_read_lock(); 1770 1771 policy = rcu_dereference(selinux_state.policy); 1772 1773 if (kern) { 1774 tclass = unmap_class(&policy->map, orig_tclass); 1775 sock = security_is_socket_class(orig_tclass); 1776 } else { 1777 tclass = orig_tclass; 1778 sock = security_is_socket_class(map_class(&policy->map, 1779 tclass)); 1780 } 1781 1782 policydb = &policy->policydb; 1783 sidtab = policy->sidtab; 1784 1785 sentry = sidtab_search_entry(sidtab, ssid); 1786 if (!sentry) { 1787 pr_err("SELinux: %s: unrecognized SID %d\n", 1788 __func__, ssid); 1789 rc = -EINVAL; 1790 goto out_unlock; 1791 } 1792 tentry = sidtab_search_entry(sidtab, tsid); 1793 if (!tentry) { 1794 pr_err("SELinux: %s: unrecognized SID %d\n", 1795 __func__, tsid); 1796 rc = -EINVAL; 1797 goto out_unlock; 1798 } 1799 1800 scontext = &sentry->context; 1801 tcontext = &tentry->context; 1802 1803 if (tclass && tclass <= policydb->p_classes.nprim) 1804 cladatum = policydb->class_val_to_struct[tclass - 1]; 1805 1806 /* Set the user identity. */ 1807 switch (specified) { 1808 case AVTAB_TRANSITION: 1809 case AVTAB_CHANGE: 1810 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1811 newcontext.user = tcontext->user; 1812 } else { 1813 /* notice this gets both DEFAULT_SOURCE and unset */ 1814 /* Use the process user identity. */ 1815 newcontext.user = scontext->user; 1816 } 1817 break; 1818 case AVTAB_MEMBER: 1819 /* Use the related object owner. */ 1820 newcontext.user = tcontext->user; 1821 break; 1822 } 1823 1824 /* Set the role to default values. */ 1825 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1826 newcontext.role = scontext->role; 1827 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1828 newcontext.role = tcontext->role; 1829 } else { 1830 if ((tclass == policydb->process_class) || sock) 1831 newcontext.role = scontext->role; 1832 else 1833 newcontext.role = OBJECT_R_VAL; 1834 } 1835 1836 /* Set the type. 1837 * Look for a type transition/member/change rule. 1838 */ 1839 avkey.source_type = scontext->type; 1840 avkey.target_type = tcontext->type; 1841 avkey.target_class = tclass; 1842 avkey.specified = specified; 1843 avnode = avtab_search_node(&policydb->te_avtab, &avkey); 1844 1845 /* If no permanent rule, also check for enabled conditional rules */ 1846 if (!avnode) { 1847 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1848 for (; node; node = avtab_search_node_next(node, specified)) { 1849 if (node->key.specified & AVTAB_ENABLED) { 1850 avnode = node; 1851 break; 1852 } 1853 } 1854 } 1855 1856 /* If a permanent rule is found, use the type from 1857 * the type transition/member/change rule. Otherwise, 1858 * set the type to its default values. 1859 */ 1860 if (avnode) { 1861 newcontext.type = avnode->datum.u.data; 1862 } else if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1863 newcontext.type = scontext->type; 1864 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1865 newcontext.type = tcontext->type; 1866 } else { 1867 if ((tclass == policydb->process_class) || sock) { 1868 /* Use the type of process. */ 1869 newcontext.type = scontext->type; 1870 } else { 1871 /* Use the type of the related object. */ 1872 newcontext.type = tcontext->type; 1873 } 1874 } 1875 1876 /* if we have a objname this is a file trans check so check those rules */ 1877 if (objname) 1878 filename_compute_type(policydb, &newcontext, scontext->type, 1879 tcontext->type, tclass, objname); 1880 1881 /* Check for class-specific changes. */ 1882 if (specified & AVTAB_TRANSITION) { 1883 /* Look for a role transition rule. */ 1884 struct role_trans_datum *rtd; 1885 struct role_trans_key rtk = { 1886 .role = scontext->role, 1887 .type = tcontext->type, 1888 .tclass = tclass, 1889 }; 1890 1891 rtd = policydb_roletr_search(policydb, &rtk); 1892 if (rtd) 1893 newcontext.role = rtd->new_role; 1894 } 1895 1896 /* Set the MLS attributes. 1897 This is done last because it may allocate memory. */ 1898 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1899 &newcontext, sock); 1900 if (rc) 1901 goto out_unlock; 1902 1903 /* Check the validity of the context. */ 1904 if (!policydb_context_isvalid(policydb, &newcontext)) { 1905 rc = compute_sid_handle_invalid_context(policy, sentry, 1906 tentry, tclass, 1907 &newcontext); 1908 if (rc) 1909 goto out_unlock; 1910 } 1911 /* Obtain the sid for the context. */ 1912 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1913 if (rc == -ESTALE) { 1914 rcu_read_unlock(); 1915 context_destroy(&newcontext); 1916 goto retry; 1917 } 1918 out_unlock: 1919 rcu_read_unlock(); 1920 context_destroy(&newcontext); 1921 out: 1922 return rc; 1923 } 1924 1925 /** 1926 * security_transition_sid - Compute the SID for a new subject/object. 1927 * @ssid: source security identifier 1928 * @tsid: target security identifier 1929 * @tclass: target security class 1930 * @qstr: object name 1931 * @out_sid: security identifier for new subject/object 1932 * 1933 * Compute a SID to use for labeling a new subject or object in the 1934 * class @tclass based on a SID pair (@ssid, @tsid). 1935 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1936 * if insufficient memory is available, or %0 if the new SID was 1937 * computed successfully. 1938 */ 1939 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1940 const struct qstr *qstr, u32 *out_sid) 1941 { 1942 return security_compute_sid(ssid, tsid, tclass, 1943 AVTAB_TRANSITION, 1944 qstr ? qstr->name : NULL, out_sid, true); 1945 } 1946 1947 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1948 const char *objname, u32 *out_sid) 1949 { 1950 return security_compute_sid(ssid, tsid, tclass, 1951 AVTAB_TRANSITION, 1952 objname, out_sid, false); 1953 } 1954 1955 /** 1956 * security_member_sid - Compute the SID for member selection. 1957 * @ssid: source security identifier 1958 * @tsid: target security identifier 1959 * @tclass: target security class 1960 * @out_sid: security identifier for selected member 1961 * 1962 * Compute a SID to use when selecting a member of a polyinstantiated 1963 * object of class @tclass based on a SID pair (@ssid, @tsid). 1964 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1965 * if insufficient memory is available, or %0 if the SID was 1966 * computed successfully. 1967 */ 1968 int security_member_sid(u32 ssid, 1969 u32 tsid, 1970 u16 tclass, 1971 u32 *out_sid) 1972 { 1973 return security_compute_sid(ssid, tsid, tclass, 1974 AVTAB_MEMBER, NULL, 1975 out_sid, false); 1976 } 1977 1978 /** 1979 * security_change_sid - Compute the SID for object relabeling. 1980 * @ssid: source security identifier 1981 * @tsid: target security identifier 1982 * @tclass: target security class 1983 * @out_sid: security identifier for selected member 1984 * 1985 * Compute a SID to use for relabeling an object of class @tclass 1986 * based on a SID pair (@ssid, @tsid). 1987 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1988 * if insufficient memory is available, or %0 if the SID was 1989 * computed successfully. 1990 */ 1991 int security_change_sid(u32 ssid, 1992 u32 tsid, 1993 u16 tclass, 1994 u32 *out_sid) 1995 { 1996 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1997 out_sid, false); 1998 } 1999 2000 static inline int convert_context_handle_invalid_context( 2001 struct policydb *policydb, 2002 struct context *context) 2003 { 2004 char *s; 2005 u32 len; 2006 2007 if (enforcing_enabled()) 2008 return -EINVAL; 2009 2010 if (!context_struct_to_string(policydb, context, &s, &len)) { 2011 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 2012 s); 2013 kfree(s); 2014 } 2015 return 0; 2016 } 2017 2018 /** 2019 * services_convert_context - Convert a security context across policies. 2020 * @args: populated convert_context_args struct 2021 * @oldc: original context 2022 * @newc: converted context 2023 * @gfp_flags: allocation flags 2024 * 2025 * Convert the values in the security context structure @oldc from the values 2026 * specified in the policy @args->oldp to the values specified in the policy 2027 * @args->newp, storing the new context in @newc, and verifying that the 2028 * context is valid under the new policy. 2029 */ 2030 int services_convert_context(struct convert_context_args *args, 2031 struct context *oldc, struct context *newc, 2032 gfp_t gfp_flags) 2033 { 2034 struct ocontext *oc; 2035 struct role_datum *role; 2036 struct type_datum *typdatum; 2037 struct user_datum *usrdatum; 2038 char *s; 2039 u32 len; 2040 int rc; 2041 2042 if (oldc->str) { 2043 s = kstrdup(oldc->str, gfp_flags); 2044 if (!s) 2045 return -ENOMEM; 2046 2047 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL); 2048 if (rc == -EINVAL) { 2049 /* 2050 * Retain string representation for later mapping. 2051 * 2052 * IMPORTANT: We need to copy the contents of oldc->str 2053 * back into s again because string_to_context_struct() 2054 * may have garbled it. 2055 */ 2056 memcpy(s, oldc->str, oldc->len); 2057 context_init(newc); 2058 newc->str = s; 2059 newc->len = oldc->len; 2060 return 0; 2061 } 2062 kfree(s); 2063 if (rc) { 2064 /* Other error condition, e.g. ENOMEM. */ 2065 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2066 oldc->str, -rc); 2067 return rc; 2068 } 2069 pr_info("SELinux: Context %s became valid (mapped).\n", 2070 oldc->str); 2071 return 0; 2072 } 2073 2074 context_init(newc); 2075 2076 /* Convert the user. */ 2077 usrdatum = symtab_search(&args->newp->p_users, 2078 sym_name(args->oldp, SYM_USERS, oldc->user - 1)); 2079 if (!usrdatum) 2080 goto bad; 2081 newc->user = usrdatum->value; 2082 2083 /* Convert the role. */ 2084 role = symtab_search(&args->newp->p_roles, 2085 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2086 if (!role) 2087 goto bad; 2088 newc->role = role->value; 2089 2090 /* Convert the type. */ 2091 typdatum = symtab_search(&args->newp->p_types, 2092 sym_name(args->oldp, SYM_TYPES, oldc->type - 1)); 2093 if (!typdatum) 2094 goto bad; 2095 newc->type = typdatum->value; 2096 2097 /* Convert the MLS fields if dealing with MLS policies */ 2098 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2099 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2100 if (rc) 2101 goto bad; 2102 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2103 /* 2104 * Switching between non-MLS and MLS policy: 2105 * ensure that the MLS fields of the context for all 2106 * existing entries in the sidtab are filled in with a 2107 * suitable default value, likely taken from one of the 2108 * initial SIDs. 2109 */ 2110 oc = args->newp->ocontexts[OCON_ISID]; 2111 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2112 oc = oc->next; 2113 if (!oc) { 2114 pr_err("SELinux: unable to look up" 2115 " the initial SIDs list\n"); 2116 goto bad; 2117 } 2118 rc = mls_range_set(newc, &oc->context[0].range); 2119 if (rc) 2120 goto bad; 2121 } 2122 2123 /* Check the validity of the new context. */ 2124 if (!policydb_context_isvalid(args->newp, newc)) { 2125 rc = convert_context_handle_invalid_context(args->oldp, oldc); 2126 if (rc) 2127 goto bad; 2128 } 2129 2130 return 0; 2131 bad: 2132 /* Map old representation to string and save it. */ 2133 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2134 if (rc) 2135 return rc; 2136 context_destroy(newc); 2137 newc->str = s; 2138 newc->len = len; 2139 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2140 newc->str); 2141 return 0; 2142 } 2143 2144 static void security_load_policycaps(struct selinux_policy *policy) 2145 { 2146 struct policydb *p; 2147 unsigned int i; 2148 struct ebitmap_node *node; 2149 2150 p = &policy->policydb; 2151 2152 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++) 2153 WRITE_ONCE(selinux_state.policycap[i], 2154 ebitmap_get_bit(&p->policycaps, i)); 2155 2156 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2157 pr_info("SELinux: policy capability %s=%d\n", 2158 selinux_policycap_names[i], 2159 ebitmap_get_bit(&p->policycaps, i)); 2160 2161 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2162 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2163 pr_info("SELinux: unknown policy capability %u\n", 2164 i); 2165 } 2166 } 2167 2168 static int security_preserve_bools(struct selinux_policy *oldpolicy, 2169 struct selinux_policy *newpolicy); 2170 2171 static void selinux_policy_free(struct selinux_policy *policy) 2172 { 2173 if (!policy) 2174 return; 2175 2176 sidtab_destroy(policy->sidtab); 2177 kfree(policy->map.mapping); 2178 policydb_destroy(&policy->policydb); 2179 kfree(policy->sidtab); 2180 kfree(policy); 2181 } 2182 2183 static void selinux_policy_cond_free(struct selinux_policy *policy) 2184 { 2185 cond_policydb_destroy_dup(&policy->policydb); 2186 kfree(policy); 2187 } 2188 2189 void selinux_policy_cancel(struct selinux_load_state *load_state) 2190 { 2191 struct selinux_state *state = &selinux_state; 2192 struct selinux_policy *oldpolicy; 2193 2194 oldpolicy = rcu_dereference_protected(state->policy, 2195 lockdep_is_held(&state->policy_mutex)); 2196 2197 sidtab_cancel_convert(oldpolicy->sidtab); 2198 selinux_policy_free(load_state->policy); 2199 kfree(load_state->convert_data); 2200 } 2201 2202 static void selinux_notify_policy_change(u32 seqno) 2203 { 2204 /* Flush external caches and notify userspace of policy load */ 2205 avc_ss_reset(seqno); 2206 selnl_notify_policyload(seqno); 2207 selinux_status_update_policyload(seqno); 2208 selinux_netlbl_cache_invalidate(); 2209 selinux_xfrm_notify_policyload(); 2210 selinux_ima_measure_state_locked(); 2211 } 2212 2213 void selinux_policy_commit(struct selinux_load_state *load_state) 2214 { 2215 struct selinux_state *state = &selinux_state; 2216 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2217 unsigned long flags; 2218 u32 seqno; 2219 2220 oldpolicy = rcu_dereference_protected(state->policy, 2221 lockdep_is_held(&state->policy_mutex)); 2222 2223 /* If switching between different policy types, log MLS status */ 2224 if (oldpolicy) { 2225 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2226 pr_info("SELinux: Disabling MLS support...\n"); 2227 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2228 pr_info("SELinux: Enabling MLS support...\n"); 2229 } 2230 2231 /* Set latest granting seqno for new policy. */ 2232 if (oldpolicy) 2233 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2234 else 2235 newpolicy->latest_granting = 1; 2236 seqno = newpolicy->latest_granting; 2237 2238 /* Install the new policy. */ 2239 if (oldpolicy) { 2240 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2241 rcu_assign_pointer(state->policy, newpolicy); 2242 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2243 } else { 2244 rcu_assign_pointer(state->policy, newpolicy); 2245 } 2246 2247 /* Load the policycaps from the new policy */ 2248 security_load_policycaps(newpolicy); 2249 2250 if (!selinux_initialized()) { 2251 /* 2252 * After first policy load, the security server is 2253 * marked as initialized and ready to handle requests and 2254 * any objects created prior to policy load are then labeled. 2255 */ 2256 selinux_mark_initialized(); 2257 selinux_complete_init(); 2258 } 2259 2260 /* Free the old policy */ 2261 synchronize_rcu(); 2262 selinux_policy_free(oldpolicy); 2263 kfree(load_state->convert_data); 2264 2265 /* Notify others of the policy change */ 2266 selinux_notify_policy_change(seqno); 2267 } 2268 2269 /** 2270 * security_load_policy - Load a security policy configuration. 2271 * @data: binary policy data 2272 * @len: length of data in bytes 2273 * @load_state: policy load state 2274 * 2275 * Load a new set of security policy configuration data, 2276 * validate it and convert the SID table as necessary. 2277 * This function will flush the access vector cache after 2278 * loading the new policy. 2279 */ 2280 int security_load_policy(void *data, size_t len, 2281 struct selinux_load_state *load_state) 2282 { 2283 struct selinux_state *state = &selinux_state; 2284 struct selinux_policy *newpolicy, *oldpolicy; 2285 struct selinux_policy_convert_data *convert_data; 2286 int rc = 0; 2287 struct policy_file file = { data, len }, *fp = &file; 2288 2289 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); 2290 if (!newpolicy) 2291 return -ENOMEM; 2292 2293 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); 2294 if (!newpolicy->sidtab) { 2295 rc = -ENOMEM; 2296 goto err_policy; 2297 } 2298 2299 rc = policydb_read(&newpolicy->policydb, fp); 2300 if (rc) 2301 goto err_sidtab; 2302 2303 newpolicy->policydb.len = len; 2304 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, 2305 &newpolicy->map); 2306 if (rc) 2307 goto err_policydb; 2308 2309 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); 2310 if (rc) { 2311 pr_err("SELinux: unable to load the initial SIDs\n"); 2312 goto err_mapping; 2313 } 2314 2315 if (!selinux_initialized()) { 2316 /* First policy load, so no need to preserve state from old policy */ 2317 load_state->policy = newpolicy; 2318 load_state->convert_data = NULL; 2319 return 0; 2320 } 2321 2322 oldpolicy = rcu_dereference_protected(state->policy, 2323 lockdep_is_held(&state->policy_mutex)); 2324 2325 /* Preserve active boolean values from the old policy */ 2326 rc = security_preserve_bools(oldpolicy, newpolicy); 2327 if (rc) { 2328 pr_err("SELinux: unable to preserve booleans\n"); 2329 goto err_free_isids; 2330 } 2331 2332 /* 2333 * Convert the internal representations of contexts 2334 * in the new SID table. 2335 */ 2336 2337 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2338 if (!convert_data) { 2339 rc = -ENOMEM; 2340 goto err_free_isids; 2341 } 2342 2343 convert_data->args.oldp = &oldpolicy->policydb; 2344 convert_data->args.newp = &newpolicy->policydb; 2345 2346 convert_data->sidtab_params.args = &convert_data->args; 2347 convert_data->sidtab_params.target = newpolicy->sidtab; 2348 2349 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); 2350 if (rc) { 2351 pr_err("SELinux: unable to convert the internal" 2352 " representation of contexts in the new SID" 2353 " table\n"); 2354 goto err_free_convert_data; 2355 } 2356 2357 load_state->policy = newpolicy; 2358 load_state->convert_data = convert_data; 2359 return 0; 2360 2361 err_free_convert_data: 2362 kfree(convert_data); 2363 err_free_isids: 2364 sidtab_destroy(newpolicy->sidtab); 2365 err_mapping: 2366 kfree(newpolicy->map.mapping); 2367 err_policydb: 2368 policydb_destroy(&newpolicy->policydb); 2369 err_sidtab: 2370 kfree(newpolicy->sidtab); 2371 err_policy: 2372 kfree(newpolicy); 2373 2374 return rc; 2375 } 2376 2377 /** 2378 * ocontext_to_sid - Helper to safely get sid for an ocontext 2379 * @sidtab: SID table 2380 * @c: ocontext structure 2381 * @index: index of the context entry (0 or 1) 2382 * @out_sid: pointer to the resulting SID value 2383 * 2384 * For all ocontexts except OCON_ISID the SID fields are populated 2385 * on-demand when needed. Since updating the SID value is an SMP-sensitive 2386 * operation, this helper must be used to do that safely. 2387 * 2388 * WARNING: This function may return -ESTALE, indicating that the caller 2389 * must retry the operation after re-acquiring the policy pointer! 2390 */ 2391 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, 2392 size_t index, u32 *out_sid) 2393 { 2394 int rc; 2395 u32 sid; 2396 2397 /* Ensure the associated sidtab entry is visible to this thread. */ 2398 sid = smp_load_acquire(&c->sid[index]); 2399 if (!sid) { 2400 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); 2401 if (rc) 2402 return rc; 2403 2404 /* 2405 * Ensure the new sidtab entry is visible to other threads 2406 * when they see the SID. 2407 */ 2408 smp_store_release(&c->sid[index], sid); 2409 } 2410 *out_sid = sid; 2411 return 0; 2412 } 2413 2414 /** 2415 * security_port_sid - Obtain the SID for a port. 2416 * @protocol: protocol number 2417 * @port: port number 2418 * @out_sid: security identifier 2419 */ 2420 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2421 { 2422 struct selinux_policy *policy; 2423 struct policydb *policydb; 2424 struct sidtab *sidtab; 2425 struct ocontext *c; 2426 int rc; 2427 2428 if (!selinux_initialized()) { 2429 *out_sid = SECINITSID_PORT; 2430 return 0; 2431 } 2432 2433 retry: 2434 rc = 0; 2435 rcu_read_lock(); 2436 policy = rcu_dereference(selinux_state.policy); 2437 policydb = &policy->policydb; 2438 sidtab = policy->sidtab; 2439 2440 c = policydb->ocontexts[OCON_PORT]; 2441 while (c) { 2442 if (c->u.port.protocol == protocol && 2443 c->u.port.low_port <= port && 2444 c->u.port.high_port >= port) 2445 break; 2446 c = c->next; 2447 } 2448 2449 if (c) { 2450 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2451 if (rc == -ESTALE) { 2452 rcu_read_unlock(); 2453 goto retry; 2454 } 2455 if (rc) 2456 goto out; 2457 } else { 2458 *out_sid = SECINITSID_PORT; 2459 } 2460 2461 out: 2462 rcu_read_unlock(); 2463 return rc; 2464 } 2465 2466 /** 2467 * security_ib_pkey_sid - Obtain the SID for a pkey. 2468 * @subnet_prefix: Subnet Prefix 2469 * @pkey_num: pkey number 2470 * @out_sid: security identifier 2471 */ 2472 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2473 { 2474 struct selinux_policy *policy; 2475 struct policydb *policydb; 2476 struct sidtab *sidtab; 2477 struct ocontext *c; 2478 int rc; 2479 2480 if (!selinux_initialized()) { 2481 *out_sid = SECINITSID_UNLABELED; 2482 return 0; 2483 } 2484 2485 retry: 2486 rc = 0; 2487 rcu_read_lock(); 2488 policy = rcu_dereference(selinux_state.policy); 2489 policydb = &policy->policydb; 2490 sidtab = policy->sidtab; 2491 2492 c = policydb->ocontexts[OCON_IBPKEY]; 2493 while (c) { 2494 if (c->u.ibpkey.low_pkey <= pkey_num && 2495 c->u.ibpkey.high_pkey >= pkey_num && 2496 c->u.ibpkey.subnet_prefix == subnet_prefix) 2497 break; 2498 2499 c = c->next; 2500 } 2501 2502 if (c) { 2503 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2504 if (rc == -ESTALE) { 2505 rcu_read_unlock(); 2506 goto retry; 2507 } 2508 if (rc) 2509 goto out; 2510 } else 2511 *out_sid = SECINITSID_UNLABELED; 2512 2513 out: 2514 rcu_read_unlock(); 2515 return rc; 2516 } 2517 2518 /** 2519 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2520 * @dev_name: device name 2521 * @port_num: port number 2522 * @out_sid: security identifier 2523 */ 2524 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) 2525 { 2526 struct selinux_policy *policy; 2527 struct policydb *policydb; 2528 struct sidtab *sidtab; 2529 struct ocontext *c; 2530 int rc; 2531 2532 if (!selinux_initialized()) { 2533 *out_sid = SECINITSID_UNLABELED; 2534 return 0; 2535 } 2536 2537 retry: 2538 rc = 0; 2539 rcu_read_lock(); 2540 policy = rcu_dereference(selinux_state.policy); 2541 policydb = &policy->policydb; 2542 sidtab = policy->sidtab; 2543 2544 c = policydb->ocontexts[OCON_IBENDPORT]; 2545 while (c) { 2546 if (c->u.ibendport.port == port_num && 2547 !strncmp(c->u.ibendport.dev_name, 2548 dev_name, 2549 IB_DEVICE_NAME_MAX)) 2550 break; 2551 2552 c = c->next; 2553 } 2554 2555 if (c) { 2556 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2557 if (rc == -ESTALE) { 2558 rcu_read_unlock(); 2559 goto retry; 2560 } 2561 if (rc) 2562 goto out; 2563 } else 2564 *out_sid = SECINITSID_UNLABELED; 2565 2566 out: 2567 rcu_read_unlock(); 2568 return rc; 2569 } 2570 2571 /** 2572 * security_netif_sid - Obtain the SID for a network interface. 2573 * @name: interface name 2574 * @if_sid: interface SID 2575 */ 2576 int security_netif_sid(const char *name, u32 *if_sid) 2577 { 2578 struct selinux_policy *policy; 2579 struct policydb *policydb; 2580 struct sidtab *sidtab; 2581 int rc; 2582 struct ocontext *c; 2583 bool wildcard_support; 2584 2585 if (!selinux_initialized()) { 2586 *if_sid = SECINITSID_NETIF; 2587 return 0; 2588 } 2589 2590 retry: 2591 rc = 0; 2592 rcu_read_lock(); 2593 policy = rcu_dereference(selinux_state.policy); 2594 policydb = &policy->policydb; 2595 sidtab = policy->sidtab; 2596 wildcard_support = ebitmap_get_bit(&policydb->policycaps, POLICYDB_CAP_NETIF_WILDCARD); 2597 2598 c = policydb->ocontexts[OCON_NETIF]; 2599 while (c) { 2600 if (wildcard_support) { 2601 if (match_wildcard(c->u.name, name)) 2602 break; 2603 } else { 2604 if (strcmp(c->u.name, name) == 0) 2605 break; 2606 } 2607 2608 c = c->next; 2609 } 2610 2611 if (c) { 2612 rc = ocontext_to_sid(sidtab, c, 0, if_sid); 2613 if (rc == -ESTALE) { 2614 rcu_read_unlock(); 2615 goto retry; 2616 } 2617 if (rc) 2618 goto out; 2619 } else 2620 *if_sid = SECINITSID_NETIF; 2621 2622 out: 2623 rcu_read_unlock(); 2624 return rc; 2625 } 2626 2627 static bool match_ipv6_addrmask(const u32 input[4], const u32 addr[4], const u32 mask[4]) 2628 { 2629 int i; 2630 2631 for (i = 0; i < 4; i++) 2632 if (addr[i] != (input[i] & mask[i])) 2633 return false; 2634 2635 return true; 2636 } 2637 2638 /** 2639 * security_node_sid - Obtain the SID for a node (host). 2640 * @domain: communication domain aka address family 2641 * @addrp: address 2642 * @addrlen: address length in bytes 2643 * @out_sid: security identifier 2644 */ 2645 int security_node_sid(u16 domain, 2646 const void *addrp, 2647 u32 addrlen, 2648 u32 *out_sid) 2649 { 2650 struct selinux_policy *policy; 2651 struct policydb *policydb; 2652 struct sidtab *sidtab; 2653 int rc; 2654 struct ocontext *c; 2655 2656 if (!selinux_initialized()) { 2657 *out_sid = SECINITSID_NODE; 2658 return 0; 2659 } 2660 2661 retry: 2662 rcu_read_lock(); 2663 policy = rcu_dereference(selinux_state.policy); 2664 policydb = &policy->policydb; 2665 sidtab = policy->sidtab; 2666 2667 switch (domain) { 2668 case AF_INET: { 2669 u32 addr; 2670 2671 rc = -EINVAL; 2672 if (addrlen != sizeof(u32)) 2673 goto out; 2674 2675 addr = *((const u32 *)addrp); 2676 2677 c = policydb->ocontexts[OCON_NODE]; 2678 while (c) { 2679 if (c->u.node.addr == (addr & c->u.node.mask)) 2680 break; 2681 c = c->next; 2682 } 2683 break; 2684 } 2685 2686 case AF_INET6: 2687 rc = -EINVAL; 2688 if (addrlen != sizeof(u64) * 2) 2689 goto out; 2690 c = policydb->ocontexts[OCON_NODE6]; 2691 while (c) { 2692 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2693 c->u.node6.mask)) 2694 break; 2695 c = c->next; 2696 } 2697 break; 2698 2699 default: 2700 rc = 0; 2701 *out_sid = SECINITSID_NODE; 2702 goto out; 2703 } 2704 2705 if (c) { 2706 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2707 if (rc == -ESTALE) { 2708 rcu_read_unlock(); 2709 goto retry; 2710 } 2711 if (rc) 2712 goto out; 2713 } else { 2714 *out_sid = SECINITSID_NODE; 2715 } 2716 2717 rc = 0; 2718 out: 2719 rcu_read_unlock(); 2720 return rc; 2721 } 2722 2723 #define SIDS_NEL 25 2724 2725 /** 2726 * security_get_user_sids - Obtain reachable SIDs for a user. 2727 * @fromsid: starting SID 2728 * @username: username 2729 * @sids: array of reachable SIDs for user 2730 * @nel: number of elements in @sids 2731 * 2732 * Generate the set of SIDs for legal security contexts 2733 * for a given user that can be reached by @fromsid. 2734 * Set *@sids to point to a dynamically allocated 2735 * array containing the set of SIDs. Set *@nel to the 2736 * number of elements in the array. 2737 */ 2738 2739 int security_get_user_sids(u32 fromsid, 2740 const char *username, 2741 u32 **sids, 2742 u32 *nel) 2743 { 2744 struct selinux_policy *policy; 2745 struct policydb *policydb; 2746 struct sidtab *sidtab; 2747 struct context *fromcon, usercon; 2748 u32 *mysids = NULL, *mysids2, sid; 2749 u32 i, j, mynel, maxnel = SIDS_NEL; 2750 struct user_datum *user; 2751 struct role_datum *role; 2752 struct ebitmap_node *rnode, *tnode; 2753 int rc; 2754 2755 *sids = NULL; 2756 *nel = 0; 2757 2758 if (!selinux_initialized()) 2759 return 0; 2760 2761 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2762 if (!mysids) 2763 return -ENOMEM; 2764 2765 retry: 2766 mynel = 0; 2767 rcu_read_lock(); 2768 policy = rcu_dereference(selinux_state.policy); 2769 policydb = &policy->policydb; 2770 sidtab = policy->sidtab; 2771 2772 context_init(&usercon); 2773 2774 rc = -EINVAL; 2775 fromcon = sidtab_search(sidtab, fromsid); 2776 if (!fromcon) 2777 goto out_unlock; 2778 2779 rc = -EINVAL; 2780 user = symtab_search(&policydb->p_users, username); 2781 if (!user) 2782 goto out_unlock; 2783 2784 usercon.user = user->value; 2785 2786 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2787 role = policydb->role_val_to_struct[i]; 2788 usercon.role = i + 1; 2789 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2790 usercon.type = j + 1; 2791 2792 if (mls_setup_user_range(policydb, fromcon, user, 2793 &usercon)) 2794 continue; 2795 2796 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2797 if (rc == -ESTALE) { 2798 rcu_read_unlock(); 2799 goto retry; 2800 } 2801 if (rc) 2802 goto out_unlock; 2803 if (mynel < maxnel) { 2804 mysids[mynel++] = sid; 2805 } else { 2806 rc = -ENOMEM; 2807 maxnel += SIDS_NEL; 2808 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2809 if (!mysids2) 2810 goto out_unlock; 2811 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2812 kfree(mysids); 2813 mysids = mysids2; 2814 mysids[mynel++] = sid; 2815 } 2816 } 2817 } 2818 rc = 0; 2819 out_unlock: 2820 rcu_read_unlock(); 2821 if (rc || !mynel) { 2822 kfree(mysids); 2823 return rc; 2824 } 2825 2826 rc = -ENOMEM; 2827 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2828 if (!mysids2) { 2829 kfree(mysids); 2830 return rc; 2831 } 2832 for (i = 0, j = 0; i < mynel; i++) { 2833 struct av_decision dummy_avd; 2834 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2835 SECCLASS_PROCESS, /* kernel value */ 2836 PROCESS__TRANSITION, AVC_STRICT, 2837 &dummy_avd); 2838 if (!rc) 2839 mysids2[j++] = mysids[i]; 2840 cond_resched(); 2841 } 2842 kfree(mysids); 2843 *sids = mysids2; 2844 *nel = j; 2845 return 0; 2846 } 2847 2848 /** 2849 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2850 * @policy: policy 2851 * @fstype: filesystem type 2852 * @path: path from root of mount 2853 * @orig_sclass: file security class 2854 * @sid: SID for path 2855 * 2856 * Obtain a SID to use for a file in a filesystem that 2857 * cannot support xattr or use a fixed labeling behavior like 2858 * transition SIDs or task SIDs. 2859 * 2860 * WARNING: This function may return -ESTALE, indicating that the caller 2861 * must retry the operation after re-acquiring the policy pointer! 2862 */ 2863 static inline int __security_genfs_sid(struct selinux_policy *policy, 2864 const char *fstype, 2865 const char *path, 2866 u16 orig_sclass, 2867 u32 *sid) 2868 { 2869 struct policydb *policydb = &policy->policydb; 2870 struct sidtab *sidtab = policy->sidtab; 2871 u16 sclass; 2872 struct genfs *genfs; 2873 struct ocontext *c; 2874 int cmp = 0; 2875 bool wildcard; 2876 2877 while (path[0] == '/' && path[1] == '/') 2878 path++; 2879 2880 sclass = unmap_class(&policy->map, orig_sclass); 2881 *sid = SECINITSID_UNLABELED; 2882 2883 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2884 cmp = strcmp(fstype, genfs->fstype); 2885 if (cmp <= 0) 2886 break; 2887 } 2888 2889 if (!genfs || cmp) 2890 return -ENOENT; 2891 2892 wildcard = ebitmap_get_bit(&policy->policydb.policycaps, 2893 POLICYDB_CAP_GENFS_SECLABEL_WILDCARD); 2894 for (c = genfs->head; c; c = c->next) { 2895 if (!c->v.sclass || sclass == c->v.sclass) { 2896 if (wildcard) { 2897 if (match_wildcard(c->u.name, path)) 2898 break; 2899 } else { 2900 size_t len = strlen(c->u.name); 2901 2902 if ((strncmp(c->u.name, path, len)) == 0) 2903 break; 2904 } 2905 } 2906 } 2907 2908 if (!c) 2909 return -ENOENT; 2910 2911 return ocontext_to_sid(sidtab, c, 0, sid); 2912 } 2913 2914 /** 2915 * security_genfs_sid - Obtain a SID for a file in a filesystem 2916 * @fstype: filesystem type 2917 * @path: path from root of mount 2918 * @orig_sclass: file security class 2919 * @sid: SID for path 2920 * 2921 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2922 * it afterward. 2923 */ 2924 int security_genfs_sid(const char *fstype, 2925 const char *path, 2926 u16 orig_sclass, 2927 u32 *sid) 2928 { 2929 struct selinux_policy *policy; 2930 int retval; 2931 2932 if (!selinux_initialized()) { 2933 *sid = SECINITSID_UNLABELED; 2934 return 0; 2935 } 2936 2937 do { 2938 rcu_read_lock(); 2939 policy = rcu_dereference(selinux_state.policy); 2940 retval = __security_genfs_sid(policy, fstype, path, 2941 orig_sclass, sid); 2942 rcu_read_unlock(); 2943 } while (retval == -ESTALE); 2944 return retval; 2945 } 2946 2947 int selinux_policy_genfs_sid(struct selinux_policy *policy, 2948 const char *fstype, 2949 const char *path, 2950 u16 orig_sclass, 2951 u32 *sid) 2952 { 2953 /* no lock required, policy is not yet accessible by other threads */ 2954 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2955 } 2956 2957 /** 2958 * security_fs_use - Determine how to handle labeling for a filesystem. 2959 * @sb: superblock in question 2960 */ 2961 int security_fs_use(struct super_block *sb) 2962 { 2963 struct selinux_policy *policy; 2964 struct policydb *policydb; 2965 struct sidtab *sidtab; 2966 int rc; 2967 struct ocontext *c; 2968 struct superblock_security_struct *sbsec = selinux_superblock(sb); 2969 const char *fstype = sb->s_type->name; 2970 2971 if (!selinux_initialized()) { 2972 sbsec->behavior = SECURITY_FS_USE_NONE; 2973 sbsec->sid = SECINITSID_UNLABELED; 2974 return 0; 2975 } 2976 2977 retry: 2978 rcu_read_lock(); 2979 policy = rcu_dereference(selinux_state.policy); 2980 policydb = &policy->policydb; 2981 sidtab = policy->sidtab; 2982 2983 c = policydb->ocontexts[OCON_FSUSE]; 2984 while (c) { 2985 if (strcmp(fstype, c->u.name) == 0) 2986 break; 2987 c = c->next; 2988 } 2989 2990 if (c) { 2991 sbsec->behavior = c->v.behavior; 2992 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); 2993 if (rc == -ESTALE) { 2994 rcu_read_unlock(); 2995 goto retry; 2996 } 2997 if (rc) 2998 goto out; 2999 } else { 3000 rc = __security_genfs_sid(policy, fstype, "/", 3001 SECCLASS_DIR, &sbsec->sid); 3002 if (rc == -ESTALE) { 3003 rcu_read_unlock(); 3004 goto retry; 3005 } 3006 if (rc) { 3007 sbsec->behavior = SECURITY_FS_USE_NONE; 3008 rc = 0; 3009 } else { 3010 sbsec->behavior = SECURITY_FS_USE_GENFS; 3011 } 3012 } 3013 3014 out: 3015 rcu_read_unlock(); 3016 return rc; 3017 } 3018 3019 int security_get_bools(struct selinux_policy *policy, 3020 u32 *len, char ***names, int **values) 3021 { 3022 struct policydb *policydb; 3023 u32 i; 3024 int rc; 3025 3026 policydb = &policy->policydb; 3027 3028 *names = NULL; 3029 *values = NULL; 3030 3031 rc = 0; 3032 *len = policydb->p_bools.nprim; 3033 if (!*len) 3034 goto out; 3035 3036 rc = -ENOMEM; 3037 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 3038 if (!*names) 3039 goto err; 3040 3041 rc = -ENOMEM; 3042 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 3043 if (!*values) 3044 goto err; 3045 3046 for (i = 0; i < *len; i++) { 3047 (*values)[i] = policydb->bool_val_to_struct[i]->state; 3048 3049 rc = -ENOMEM; 3050 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 3051 GFP_ATOMIC); 3052 if (!(*names)[i]) 3053 goto err; 3054 } 3055 rc = 0; 3056 out: 3057 return rc; 3058 err: 3059 if (*names) { 3060 for (i = 0; i < *len; i++) 3061 kfree((*names)[i]); 3062 kfree(*names); 3063 } 3064 kfree(*values); 3065 *len = 0; 3066 *names = NULL; 3067 *values = NULL; 3068 goto out; 3069 } 3070 3071 3072 int security_set_bools(u32 len, const int *values) 3073 { 3074 struct selinux_state *state = &selinux_state; 3075 struct selinux_policy *newpolicy, *oldpolicy; 3076 int rc; 3077 u32 i, seqno = 0; 3078 3079 if (!selinux_initialized()) 3080 return -EINVAL; 3081 3082 oldpolicy = rcu_dereference_protected(state->policy, 3083 lockdep_is_held(&state->policy_mutex)); 3084 3085 /* Consistency check on number of booleans, should never fail */ 3086 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) 3087 return -EINVAL; 3088 3089 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); 3090 if (!newpolicy) 3091 return -ENOMEM; 3092 3093 /* 3094 * Deep copy only the parts of the policydb that might be 3095 * modified as a result of changing booleans. 3096 */ 3097 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); 3098 if (rc) { 3099 kfree(newpolicy); 3100 return -ENOMEM; 3101 } 3102 3103 /* Update the boolean states in the copy */ 3104 for (i = 0; i < len; i++) { 3105 int new_state = !!values[i]; 3106 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; 3107 3108 if (new_state != old_state) { 3109 audit_log(audit_context(), GFP_ATOMIC, 3110 AUDIT_MAC_CONFIG_CHANGE, 3111 "bool=%s val=%d old_val=%d auid=%u ses=%u", 3112 sym_name(&newpolicy->policydb, SYM_BOOLS, i), 3113 new_state, 3114 old_state, 3115 from_kuid(&init_user_ns, audit_get_loginuid(current)), 3116 audit_get_sessionid(current)); 3117 newpolicy->policydb.bool_val_to_struct[i]->state = new_state; 3118 } 3119 } 3120 3121 /* Re-evaluate the conditional rules in the copy */ 3122 evaluate_cond_nodes(&newpolicy->policydb); 3123 3124 /* Set latest granting seqno for new policy */ 3125 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 3126 seqno = newpolicy->latest_granting; 3127 3128 /* Install the new policy */ 3129 rcu_assign_pointer(state->policy, newpolicy); 3130 3131 /* 3132 * Free the conditional portions of the old policydb 3133 * that were copied for the new policy, and the oldpolicy 3134 * structure itself but not what it references. 3135 */ 3136 synchronize_rcu(); 3137 selinux_policy_cond_free(oldpolicy); 3138 3139 /* Notify others of the policy change */ 3140 selinux_notify_policy_change(seqno); 3141 return 0; 3142 } 3143 3144 int security_get_bool_value(u32 index) 3145 { 3146 struct selinux_policy *policy; 3147 struct policydb *policydb; 3148 int rc; 3149 u32 len; 3150 3151 if (!selinux_initialized()) 3152 return 0; 3153 3154 rcu_read_lock(); 3155 policy = rcu_dereference(selinux_state.policy); 3156 policydb = &policy->policydb; 3157 3158 rc = -EFAULT; 3159 len = policydb->p_bools.nprim; 3160 if (index >= len) 3161 goto out; 3162 3163 rc = policydb->bool_val_to_struct[index]->state; 3164 out: 3165 rcu_read_unlock(); 3166 return rc; 3167 } 3168 3169 static int security_preserve_bools(struct selinux_policy *oldpolicy, 3170 struct selinux_policy *newpolicy) 3171 { 3172 int rc, *bvalues = NULL; 3173 char **bnames = NULL; 3174 struct cond_bool_datum *booldatum; 3175 u32 i, nbools = 0; 3176 3177 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); 3178 if (rc) 3179 goto out; 3180 for (i = 0; i < nbools; i++) { 3181 booldatum = symtab_search(&newpolicy->policydb.p_bools, 3182 bnames[i]); 3183 if (booldatum) 3184 booldatum->state = bvalues[i]; 3185 } 3186 evaluate_cond_nodes(&newpolicy->policydb); 3187 3188 out: 3189 if (bnames) { 3190 for (i = 0; i < nbools; i++) 3191 kfree(bnames[i]); 3192 } 3193 kfree(bnames); 3194 kfree(bvalues); 3195 return rc; 3196 } 3197 3198 /* 3199 * security_sid_mls_copy() - computes a new sid based on the given 3200 * sid and the mls portion of mls_sid. 3201 */ 3202 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 3203 { 3204 struct selinux_policy *policy; 3205 struct policydb *policydb; 3206 struct sidtab *sidtab; 3207 struct context *context1; 3208 struct context *context2; 3209 struct context newcon; 3210 char *s; 3211 u32 len; 3212 int rc; 3213 3214 if (!selinux_initialized()) { 3215 *new_sid = sid; 3216 return 0; 3217 } 3218 3219 retry: 3220 rc = 0; 3221 context_init(&newcon); 3222 3223 rcu_read_lock(); 3224 policy = rcu_dereference(selinux_state.policy); 3225 policydb = &policy->policydb; 3226 sidtab = policy->sidtab; 3227 3228 if (!policydb->mls_enabled) { 3229 *new_sid = sid; 3230 goto out_unlock; 3231 } 3232 3233 rc = -EINVAL; 3234 context1 = sidtab_search(sidtab, sid); 3235 if (!context1) { 3236 pr_err("SELinux: %s: unrecognized SID %d\n", 3237 __func__, sid); 3238 goto out_unlock; 3239 } 3240 3241 rc = -EINVAL; 3242 context2 = sidtab_search(sidtab, mls_sid); 3243 if (!context2) { 3244 pr_err("SELinux: %s: unrecognized SID %d\n", 3245 __func__, mls_sid); 3246 goto out_unlock; 3247 } 3248 3249 newcon.user = context1->user; 3250 newcon.role = context1->role; 3251 newcon.type = context1->type; 3252 rc = mls_context_cpy(&newcon, context2); 3253 if (rc) 3254 goto out_unlock; 3255 3256 /* Check the validity of the new context. */ 3257 if (!policydb_context_isvalid(policydb, &newcon)) { 3258 rc = convert_context_handle_invalid_context(policydb, 3259 &newcon); 3260 if (rc) { 3261 if (!context_struct_to_string(policydb, &newcon, &s, 3262 &len)) { 3263 struct audit_buffer *ab; 3264 3265 ab = audit_log_start(audit_context(), 3266 GFP_ATOMIC, 3267 AUDIT_SELINUX_ERR); 3268 audit_log_format(ab, 3269 "op=security_sid_mls_copy invalid_context="); 3270 /* don't record NUL with untrusted strings */ 3271 audit_log_n_untrustedstring(ab, s, len - 1); 3272 audit_log_end(ab); 3273 kfree(s); 3274 } 3275 goto out_unlock; 3276 } 3277 } 3278 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3279 if (rc == -ESTALE) { 3280 rcu_read_unlock(); 3281 context_destroy(&newcon); 3282 goto retry; 3283 } 3284 out_unlock: 3285 rcu_read_unlock(); 3286 context_destroy(&newcon); 3287 return rc; 3288 } 3289 3290 /** 3291 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3292 * @nlbl_sid: NetLabel SID 3293 * @nlbl_type: NetLabel labeling protocol type 3294 * @xfrm_sid: XFRM SID 3295 * @peer_sid: network peer sid 3296 * 3297 * Description: 3298 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3299 * resolved into a single SID it is returned via @peer_sid and the function 3300 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3301 * returns a negative value. A table summarizing the behavior is below: 3302 * 3303 * | function return | @sid 3304 * ------------------------------+-----------------+----------------- 3305 * no peer labels | 0 | SECSID_NULL 3306 * single peer label | 0 | <peer_label> 3307 * multiple, consistent labels | 0 | <peer_label> 3308 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3309 * 3310 */ 3311 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 3312 u32 xfrm_sid, 3313 u32 *peer_sid) 3314 { 3315 struct selinux_policy *policy; 3316 struct policydb *policydb; 3317 struct sidtab *sidtab; 3318 int rc; 3319 struct context *nlbl_ctx; 3320 struct context *xfrm_ctx; 3321 3322 *peer_sid = SECSID_NULL; 3323 3324 /* handle the common (which also happens to be the set of easy) cases 3325 * right away, these two if statements catch everything involving a 3326 * single or absent peer SID/label */ 3327 if (xfrm_sid == SECSID_NULL) { 3328 *peer_sid = nlbl_sid; 3329 return 0; 3330 } 3331 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3332 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3333 * is present */ 3334 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3335 *peer_sid = xfrm_sid; 3336 return 0; 3337 } 3338 3339 if (!selinux_initialized()) 3340 return 0; 3341 3342 rcu_read_lock(); 3343 policy = rcu_dereference(selinux_state.policy); 3344 policydb = &policy->policydb; 3345 sidtab = policy->sidtab; 3346 3347 /* 3348 * We don't need to check initialized here since the only way both 3349 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3350 * security server was initialized and state->initialized was true. 3351 */ 3352 if (!policydb->mls_enabled) { 3353 rc = 0; 3354 goto out; 3355 } 3356 3357 rc = -EINVAL; 3358 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3359 if (!nlbl_ctx) { 3360 pr_err("SELinux: %s: unrecognized SID %d\n", 3361 __func__, nlbl_sid); 3362 goto out; 3363 } 3364 rc = -EINVAL; 3365 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3366 if (!xfrm_ctx) { 3367 pr_err("SELinux: %s: unrecognized SID %d\n", 3368 __func__, xfrm_sid); 3369 goto out; 3370 } 3371 rc = (mls_context_equal(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3372 if (rc) 3373 goto out; 3374 3375 /* at present NetLabel SIDs/labels really only carry MLS 3376 * information so if the MLS portion of the NetLabel SID 3377 * matches the MLS portion of the labeled XFRM SID/label 3378 * then pass along the XFRM SID as it is the most 3379 * expressive */ 3380 *peer_sid = xfrm_sid; 3381 out: 3382 rcu_read_unlock(); 3383 return rc; 3384 } 3385 3386 static int get_classes_callback(void *k, void *d, void *args) 3387 { 3388 struct class_datum *datum = d; 3389 char *name = k, **classes = args; 3390 u32 value = datum->value - 1; 3391 3392 classes[value] = kstrdup(name, GFP_ATOMIC); 3393 if (!classes[value]) 3394 return -ENOMEM; 3395 3396 return 0; 3397 } 3398 3399 int security_get_classes(struct selinux_policy *policy, 3400 char ***classes, u32 *nclasses) 3401 { 3402 struct policydb *policydb; 3403 int rc; 3404 3405 policydb = &policy->policydb; 3406 3407 rc = -ENOMEM; 3408 *nclasses = policydb->p_classes.nprim; 3409 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3410 if (!*classes) 3411 goto out; 3412 3413 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3414 *classes); 3415 if (rc) { 3416 u32 i; 3417 3418 for (i = 0; i < *nclasses; i++) 3419 kfree((*classes)[i]); 3420 kfree(*classes); 3421 } 3422 3423 out: 3424 return rc; 3425 } 3426 3427 static int get_permissions_callback(void *k, void *d, void *args) 3428 { 3429 struct perm_datum *datum = d; 3430 char *name = k, **perms = args; 3431 u32 value = datum->value - 1; 3432 3433 perms[value] = kstrdup(name, GFP_ATOMIC); 3434 if (!perms[value]) 3435 return -ENOMEM; 3436 3437 return 0; 3438 } 3439 3440 int security_get_permissions(struct selinux_policy *policy, 3441 const char *class, char ***perms, u32 *nperms) 3442 { 3443 struct policydb *policydb; 3444 u32 i; 3445 int rc; 3446 struct class_datum *match; 3447 3448 policydb = &policy->policydb; 3449 3450 rc = -EINVAL; 3451 match = symtab_search(&policydb->p_classes, class); 3452 if (!match) { 3453 pr_err("SELinux: %s: unrecognized class %s\n", 3454 __func__, class); 3455 goto out; 3456 } 3457 3458 rc = -ENOMEM; 3459 *nperms = match->permissions.nprim; 3460 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3461 if (!*perms) 3462 goto out; 3463 3464 if (match->comdatum) { 3465 rc = hashtab_map(&match->comdatum->permissions.table, 3466 get_permissions_callback, *perms); 3467 if (rc) 3468 goto err; 3469 } 3470 3471 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3472 *perms); 3473 if (rc) 3474 goto err; 3475 3476 out: 3477 return rc; 3478 3479 err: 3480 for (i = 0; i < *nperms; i++) 3481 kfree((*perms)[i]); 3482 kfree(*perms); 3483 return rc; 3484 } 3485 3486 int security_get_reject_unknown(void) 3487 { 3488 struct selinux_policy *policy; 3489 int value; 3490 3491 if (!selinux_initialized()) 3492 return 0; 3493 3494 rcu_read_lock(); 3495 policy = rcu_dereference(selinux_state.policy); 3496 value = policy->policydb.reject_unknown; 3497 rcu_read_unlock(); 3498 return value; 3499 } 3500 3501 int security_get_allow_unknown(void) 3502 { 3503 struct selinux_policy *policy; 3504 int value; 3505 3506 if (!selinux_initialized()) 3507 return 0; 3508 3509 rcu_read_lock(); 3510 policy = rcu_dereference(selinux_state.policy); 3511 value = policy->policydb.allow_unknown; 3512 rcu_read_unlock(); 3513 return value; 3514 } 3515 3516 /** 3517 * security_policycap_supported - Check for a specific policy capability 3518 * @req_cap: capability 3519 * 3520 * Description: 3521 * This function queries the currently loaded policy to see if it supports the 3522 * capability specified by @req_cap. Returns true (1) if the capability is 3523 * supported, false (0) if it isn't supported. 3524 * 3525 */ 3526 int security_policycap_supported(unsigned int req_cap) 3527 { 3528 struct selinux_policy *policy; 3529 int rc; 3530 3531 if (!selinux_initialized()) 3532 return 0; 3533 3534 rcu_read_lock(); 3535 policy = rcu_dereference(selinux_state.policy); 3536 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3537 rcu_read_unlock(); 3538 3539 return rc; 3540 } 3541 3542 struct selinux_audit_rule { 3543 u32 au_seqno; 3544 struct context au_ctxt; 3545 }; 3546 3547 void selinux_audit_rule_free(void *vrule) 3548 { 3549 struct selinux_audit_rule *rule = vrule; 3550 3551 if (rule) { 3552 context_destroy(&rule->au_ctxt); 3553 kfree(rule); 3554 } 3555 } 3556 3557 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, 3558 gfp_t gfp) 3559 { 3560 struct selinux_state *state = &selinux_state; 3561 struct selinux_policy *policy; 3562 struct policydb *policydb; 3563 struct selinux_audit_rule *tmprule; 3564 struct role_datum *roledatum; 3565 struct type_datum *typedatum; 3566 struct user_datum *userdatum; 3567 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3568 int rc = 0; 3569 3570 *rule = NULL; 3571 3572 if (!selinux_initialized()) 3573 return -EOPNOTSUPP; 3574 3575 switch (field) { 3576 case AUDIT_SUBJ_USER: 3577 case AUDIT_SUBJ_ROLE: 3578 case AUDIT_SUBJ_TYPE: 3579 case AUDIT_OBJ_USER: 3580 case AUDIT_OBJ_ROLE: 3581 case AUDIT_OBJ_TYPE: 3582 /* only 'equals' and 'not equals' fit user, role, and type */ 3583 if (op != Audit_equal && op != Audit_not_equal) 3584 return -EINVAL; 3585 break; 3586 case AUDIT_SUBJ_SEN: 3587 case AUDIT_SUBJ_CLR: 3588 case AUDIT_OBJ_LEV_LOW: 3589 case AUDIT_OBJ_LEV_HIGH: 3590 /* we do not allow a range, indicated by the presence of '-' */ 3591 if (strchr(rulestr, '-')) 3592 return -EINVAL; 3593 break; 3594 default: 3595 /* only the above fields are valid */ 3596 return -EINVAL; 3597 } 3598 3599 tmprule = kzalloc(sizeof(struct selinux_audit_rule), gfp); 3600 if (!tmprule) 3601 return -ENOMEM; 3602 context_init(&tmprule->au_ctxt); 3603 3604 rcu_read_lock(); 3605 policy = rcu_dereference(state->policy); 3606 policydb = &policy->policydb; 3607 tmprule->au_seqno = policy->latest_granting; 3608 switch (field) { 3609 case AUDIT_SUBJ_USER: 3610 case AUDIT_OBJ_USER: 3611 userdatum = symtab_search(&policydb->p_users, rulestr); 3612 if (!userdatum) { 3613 rc = -EINVAL; 3614 goto err; 3615 } 3616 tmprule->au_ctxt.user = userdatum->value; 3617 break; 3618 case AUDIT_SUBJ_ROLE: 3619 case AUDIT_OBJ_ROLE: 3620 roledatum = symtab_search(&policydb->p_roles, rulestr); 3621 if (!roledatum) { 3622 rc = -EINVAL; 3623 goto err; 3624 } 3625 tmprule->au_ctxt.role = roledatum->value; 3626 break; 3627 case AUDIT_SUBJ_TYPE: 3628 case AUDIT_OBJ_TYPE: 3629 typedatum = symtab_search(&policydb->p_types, rulestr); 3630 if (!typedatum) { 3631 rc = -EINVAL; 3632 goto err; 3633 } 3634 tmprule->au_ctxt.type = typedatum->value; 3635 break; 3636 case AUDIT_SUBJ_SEN: 3637 case AUDIT_SUBJ_CLR: 3638 case AUDIT_OBJ_LEV_LOW: 3639 case AUDIT_OBJ_LEV_HIGH: 3640 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3641 GFP_ATOMIC); 3642 if (rc) 3643 goto err; 3644 break; 3645 } 3646 rcu_read_unlock(); 3647 3648 *rule = tmprule; 3649 return 0; 3650 3651 err: 3652 rcu_read_unlock(); 3653 selinux_audit_rule_free(tmprule); 3654 *rule = NULL; 3655 return rc; 3656 } 3657 3658 /* Check to see if the rule contains any selinux fields */ 3659 int selinux_audit_rule_known(struct audit_krule *rule) 3660 { 3661 u32 i; 3662 3663 for (i = 0; i < rule->field_count; i++) { 3664 struct audit_field *f = &rule->fields[i]; 3665 switch (f->type) { 3666 case AUDIT_SUBJ_USER: 3667 case AUDIT_SUBJ_ROLE: 3668 case AUDIT_SUBJ_TYPE: 3669 case AUDIT_SUBJ_SEN: 3670 case AUDIT_SUBJ_CLR: 3671 case AUDIT_OBJ_USER: 3672 case AUDIT_OBJ_ROLE: 3673 case AUDIT_OBJ_TYPE: 3674 case AUDIT_OBJ_LEV_LOW: 3675 case AUDIT_OBJ_LEV_HIGH: 3676 return 1; 3677 } 3678 } 3679 3680 return 0; 3681 } 3682 3683 int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule) 3684 { 3685 struct selinux_state *state = &selinux_state; 3686 struct selinux_policy *policy; 3687 struct context *ctxt; 3688 struct mls_level *level; 3689 struct selinux_audit_rule *rule = vrule; 3690 int match = 0; 3691 3692 if (unlikely(!rule)) { 3693 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3694 return -ENOENT; 3695 } 3696 3697 if (!selinux_initialized()) 3698 return 0; 3699 3700 rcu_read_lock(); 3701 3702 policy = rcu_dereference(state->policy); 3703 3704 if (rule->au_seqno < policy->latest_granting) { 3705 match = -ESTALE; 3706 goto out; 3707 } 3708 3709 ctxt = sidtab_search(policy->sidtab, prop->selinux.secid); 3710 if (unlikely(!ctxt)) { 3711 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3712 prop->selinux.secid); 3713 match = -ENOENT; 3714 goto out; 3715 } 3716 3717 /* a field/op pair that is not caught here will simply fall through 3718 without a match */ 3719 switch (field) { 3720 case AUDIT_SUBJ_USER: 3721 case AUDIT_OBJ_USER: 3722 switch (op) { 3723 case Audit_equal: 3724 match = (ctxt->user == rule->au_ctxt.user); 3725 break; 3726 case Audit_not_equal: 3727 match = (ctxt->user != rule->au_ctxt.user); 3728 break; 3729 } 3730 break; 3731 case AUDIT_SUBJ_ROLE: 3732 case AUDIT_OBJ_ROLE: 3733 switch (op) { 3734 case Audit_equal: 3735 match = (ctxt->role == rule->au_ctxt.role); 3736 break; 3737 case Audit_not_equal: 3738 match = (ctxt->role != rule->au_ctxt.role); 3739 break; 3740 } 3741 break; 3742 case AUDIT_SUBJ_TYPE: 3743 case AUDIT_OBJ_TYPE: 3744 switch (op) { 3745 case Audit_equal: 3746 match = (ctxt->type == rule->au_ctxt.type); 3747 break; 3748 case Audit_not_equal: 3749 match = (ctxt->type != rule->au_ctxt.type); 3750 break; 3751 } 3752 break; 3753 case AUDIT_SUBJ_SEN: 3754 case AUDIT_SUBJ_CLR: 3755 case AUDIT_OBJ_LEV_LOW: 3756 case AUDIT_OBJ_LEV_HIGH: 3757 level = ((field == AUDIT_SUBJ_SEN || 3758 field == AUDIT_OBJ_LEV_LOW) ? 3759 &ctxt->range.level[0] : &ctxt->range.level[1]); 3760 switch (op) { 3761 case Audit_equal: 3762 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3763 level); 3764 break; 3765 case Audit_not_equal: 3766 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3767 level); 3768 break; 3769 case Audit_lt: 3770 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3771 level) && 3772 !mls_level_eq(&rule->au_ctxt.range.level[0], 3773 level)); 3774 break; 3775 case Audit_le: 3776 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3777 level); 3778 break; 3779 case Audit_gt: 3780 match = (mls_level_dom(level, 3781 &rule->au_ctxt.range.level[0]) && 3782 !mls_level_eq(level, 3783 &rule->au_ctxt.range.level[0])); 3784 break; 3785 case Audit_ge: 3786 match = mls_level_dom(level, 3787 &rule->au_ctxt.range.level[0]); 3788 break; 3789 } 3790 } 3791 3792 out: 3793 rcu_read_unlock(); 3794 return match; 3795 } 3796 3797 static int aurule_avc_callback(u32 event) 3798 { 3799 if (event == AVC_CALLBACK_RESET) 3800 return audit_update_lsm_rules(); 3801 return 0; 3802 } 3803 3804 static int __init aurule_init(void) 3805 { 3806 int err; 3807 3808 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3809 if (err) 3810 panic("avc_add_callback() failed, error %d\n", err); 3811 3812 return err; 3813 } 3814 __initcall(aurule_init); 3815 3816 #ifdef CONFIG_NETLABEL 3817 /** 3818 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3819 * @secattr: the NetLabel packet security attributes 3820 * @sid: the SELinux SID 3821 * 3822 * Description: 3823 * Attempt to cache the context in @ctx, which was derived from the packet in 3824 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3825 * already been initialized. 3826 * 3827 */ 3828 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3829 u32 sid) 3830 { 3831 u32 *sid_cache; 3832 3833 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3834 if (sid_cache == NULL) 3835 return; 3836 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3837 if (secattr->cache == NULL) { 3838 kfree(sid_cache); 3839 return; 3840 } 3841 3842 *sid_cache = sid; 3843 secattr->cache->free = kfree; 3844 secattr->cache->data = sid_cache; 3845 secattr->flags |= NETLBL_SECATTR_CACHE; 3846 } 3847 3848 /** 3849 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3850 * @secattr: the NetLabel packet security attributes 3851 * @sid: the SELinux SID 3852 * 3853 * Description: 3854 * Convert the given NetLabel security attributes in @secattr into a 3855 * SELinux SID. If the @secattr field does not contain a full SELinux 3856 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3857 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3858 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3859 * conversion for future lookups. Returns zero on success, negative values on 3860 * failure. 3861 * 3862 */ 3863 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3864 u32 *sid) 3865 { 3866 struct selinux_policy *policy; 3867 struct policydb *policydb; 3868 struct sidtab *sidtab; 3869 int rc; 3870 struct context *ctx; 3871 struct context ctx_new; 3872 3873 if (!selinux_initialized()) { 3874 *sid = SECSID_NULL; 3875 return 0; 3876 } 3877 3878 retry: 3879 rc = 0; 3880 rcu_read_lock(); 3881 policy = rcu_dereference(selinux_state.policy); 3882 policydb = &policy->policydb; 3883 sidtab = policy->sidtab; 3884 3885 if (secattr->flags & NETLBL_SECATTR_CACHE) 3886 *sid = *(u32 *)secattr->cache->data; 3887 else if (secattr->flags & NETLBL_SECATTR_SECID) 3888 *sid = secattr->attr.secid; 3889 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3890 rc = -EIDRM; 3891 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3892 if (ctx == NULL) 3893 goto out; 3894 3895 context_init(&ctx_new); 3896 ctx_new.user = ctx->user; 3897 ctx_new.role = ctx->role; 3898 ctx_new.type = ctx->type; 3899 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3900 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3901 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3902 if (rc) 3903 goto out; 3904 } 3905 rc = -EIDRM; 3906 if (!mls_context_isvalid(policydb, &ctx_new)) { 3907 ebitmap_destroy(&ctx_new.range.level[0].cat); 3908 goto out; 3909 } 3910 3911 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3912 ebitmap_destroy(&ctx_new.range.level[0].cat); 3913 if (rc == -ESTALE) { 3914 rcu_read_unlock(); 3915 goto retry; 3916 } 3917 if (rc) 3918 goto out; 3919 3920 security_netlbl_cache_add(secattr, *sid); 3921 } else 3922 *sid = SECSID_NULL; 3923 3924 out: 3925 rcu_read_unlock(); 3926 return rc; 3927 } 3928 3929 /** 3930 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3931 * @sid: the SELinux SID 3932 * @secattr: the NetLabel packet security attributes 3933 * 3934 * Description: 3935 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3936 * Returns zero on success, negative values on failure. 3937 * 3938 */ 3939 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3940 { 3941 struct selinux_policy *policy; 3942 struct policydb *policydb; 3943 int rc; 3944 struct context *ctx; 3945 3946 if (!selinux_initialized()) 3947 return 0; 3948 3949 rcu_read_lock(); 3950 policy = rcu_dereference(selinux_state.policy); 3951 policydb = &policy->policydb; 3952 3953 rc = -ENOENT; 3954 ctx = sidtab_search(policy->sidtab, sid); 3955 if (ctx == NULL) 3956 goto out; 3957 3958 rc = -ENOMEM; 3959 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3960 GFP_ATOMIC); 3961 if (secattr->domain == NULL) 3962 goto out; 3963 3964 secattr->attr.secid = sid; 3965 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3966 mls_export_netlbl_lvl(policydb, ctx, secattr); 3967 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3968 out: 3969 rcu_read_unlock(); 3970 return rc; 3971 } 3972 #endif /* CONFIG_NETLABEL */ 3973 3974 /** 3975 * __security_read_policy - read the policy. 3976 * @policy: SELinux policy 3977 * @data: binary policy data 3978 * @len: length of data in bytes 3979 * 3980 */ 3981 static int __security_read_policy(struct selinux_policy *policy, 3982 void *data, size_t *len) 3983 { 3984 int rc; 3985 struct policy_file fp; 3986 3987 fp.data = data; 3988 fp.len = *len; 3989 3990 rc = policydb_write(&policy->policydb, &fp); 3991 if (rc) 3992 return rc; 3993 3994 *len = (unsigned long)fp.data - (unsigned long)data; 3995 return 0; 3996 } 3997 3998 /** 3999 * security_read_policy - read the policy. 4000 * @data: binary policy data 4001 * @len: length of data in bytes 4002 * 4003 */ 4004 int security_read_policy(void **data, size_t *len) 4005 { 4006 struct selinux_state *state = &selinux_state; 4007 struct selinux_policy *policy; 4008 4009 policy = rcu_dereference_protected( 4010 state->policy, lockdep_is_held(&state->policy_mutex)); 4011 if (!policy) 4012 return -EINVAL; 4013 4014 *len = policy->policydb.len; 4015 *data = vmalloc_user(*len); 4016 if (!*data) 4017 return -ENOMEM; 4018 4019 return __security_read_policy(policy, *data, len); 4020 } 4021 4022 /** 4023 * security_read_state_kernel - read the policy. 4024 * @data: binary policy data 4025 * @len: length of data in bytes 4026 * 4027 * Allocates kernel memory for reading SELinux policy. 4028 * This function is for internal use only and should not 4029 * be used for returning data to user space. 4030 * 4031 * This function must be called with policy_mutex held. 4032 */ 4033 int security_read_state_kernel(void **data, size_t *len) 4034 { 4035 int err; 4036 struct selinux_state *state = &selinux_state; 4037 struct selinux_policy *policy; 4038 4039 policy = rcu_dereference_protected( 4040 state->policy, lockdep_is_held(&state->policy_mutex)); 4041 if (!policy) 4042 return -EINVAL; 4043 4044 *len = policy->policydb.len; 4045 *data = vmalloc(*len); 4046 if (!*data) 4047 return -ENOMEM; 4048 4049 err = __security_read_policy(policy, *data, len); 4050 if (err) { 4051 vfree(*data); 4052 *data = NULL; 4053 *len = 0; 4054 } 4055 return err; 4056 } 4057