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 /* neveraudit domain? */ 1157 if (ebitmap_get_bit(&policydb->neveraudit_map, scontext->type)) 1158 avd->flags |= AVD_FLAGS_NEVERAUDIT; 1159 1160 /* both permissive and neveraudit => allow */ 1161 if (avd->flags == (AVD_FLAGS_PERMISSIVE|AVD_FLAGS_NEVERAUDIT)) 1162 goto allow; 1163 1164 tcontext = sidtab_search(sidtab, tsid); 1165 if (!tcontext) { 1166 pr_err("SELinux: %s: unrecognized SID %d\n", 1167 __func__, tsid); 1168 goto out; 1169 } 1170 1171 tclass = unmap_class(&policy->map, orig_tclass); 1172 if (unlikely(orig_tclass && !tclass)) { 1173 if (policydb->allow_unknown) 1174 goto allow; 1175 goto out; 1176 } 1177 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1178 xperms); 1179 map_decision(&policy->map, orig_tclass, avd, 1180 policydb->allow_unknown); 1181 out: 1182 rcu_read_unlock(); 1183 if (avd->flags & AVD_FLAGS_NEVERAUDIT) 1184 avd->auditallow = avd->auditdeny = 0; 1185 return; 1186 allow: 1187 avd->allowed = 0xffffffff; 1188 goto out; 1189 } 1190 1191 void security_compute_av_user(u32 ssid, 1192 u32 tsid, 1193 u16 tclass, 1194 struct av_decision *avd) 1195 { 1196 struct selinux_policy *policy; 1197 struct policydb *policydb; 1198 struct sidtab *sidtab; 1199 struct context *scontext = NULL, *tcontext = NULL; 1200 1201 rcu_read_lock(); 1202 policy = rcu_dereference(selinux_state.policy); 1203 avd_init(policy, avd); 1204 if (!selinux_initialized()) 1205 goto allow; 1206 1207 policydb = &policy->policydb; 1208 sidtab = policy->sidtab; 1209 1210 scontext = sidtab_search(sidtab, ssid); 1211 if (!scontext) { 1212 pr_err("SELinux: %s: unrecognized SID %d\n", 1213 __func__, ssid); 1214 goto out; 1215 } 1216 1217 /* permissive domain? */ 1218 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1219 avd->flags |= AVD_FLAGS_PERMISSIVE; 1220 1221 /* neveraudit domain? */ 1222 if (ebitmap_get_bit(&policydb->neveraudit_map, scontext->type)) 1223 avd->flags |= AVD_FLAGS_NEVERAUDIT; 1224 1225 /* both permissive and neveraudit => allow */ 1226 if (avd->flags == (AVD_FLAGS_PERMISSIVE|AVD_FLAGS_NEVERAUDIT)) 1227 goto allow; 1228 1229 tcontext = sidtab_search(sidtab, tsid); 1230 if (!tcontext) { 1231 pr_err("SELinux: %s: unrecognized SID %d\n", 1232 __func__, tsid); 1233 goto out; 1234 } 1235 1236 if (unlikely(!tclass)) { 1237 if (policydb->allow_unknown) 1238 goto allow; 1239 goto out; 1240 } 1241 1242 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1243 NULL); 1244 out: 1245 rcu_read_unlock(); 1246 if (avd->flags & AVD_FLAGS_NEVERAUDIT) 1247 avd->auditallow = avd->auditdeny = 0; 1248 return; 1249 allow: 1250 avd->allowed = 0xffffffff; 1251 goto out; 1252 } 1253 1254 /* 1255 * Write the security context string representation of 1256 * the context structure `context' into a dynamically 1257 * allocated string of the correct size. Set `*scontext' 1258 * to point to this string and set `*scontext_len' to 1259 * the length of the string. 1260 */ 1261 static int context_struct_to_string(struct policydb *p, 1262 struct context *context, 1263 char **scontext, u32 *scontext_len) 1264 { 1265 char *scontextp; 1266 1267 if (scontext) 1268 *scontext = NULL; 1269 *scontext_len = 0; 1270 1271 if (context->len) { 1272 *scontext_len = context->len; 1273 if (scontext) { 1274 *scontext = kstrdup(context->str, GFP_ATOMIC); 1275 if (!(*scontext)) 1276 return -ENOMEM; 1277 } 1278 return 0; 1279 } 1280 1281 /* Compute the size of the context. */ 1282 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1283 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1284 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1285 *scontext_len += mls_compute_context_len(p, context); 1286 1287 if (!scontext) 1288 return 0; 1289 1290 /* Allocate space for the context; caller must free this space. */ 1291 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1292 if (!scontextp) 1293 return -ENOMEM; 1294 *scontext = scontextp; 1295 1296 /* 1297 * Copy the user name, role name and type name into the context. 1298 */ 1299 scontextp += sprintf(scontextp, "%s:%s:%s", 1300 sym_name(p, SYM_USERS, context->user - 1), 1301 sym_name(p, SYM_ROLES, context->role - 1), 1302 sym_name(p, SYM_TYPES, context->type - 1)); 1303 1304 mls_sid_to_context(p, context, &scontextp); 1305 1306 *scontextp = 0; 1307 1308 return 0; 1309 } 1310 1311 static int sidtab_entry_to_string(struct policydb *p, 1312 struct sidtab *sidtab, 1313 struct sidtab_entry *entry, 1314 char **scontext, u32 *scontext_len) 1315 { 1316 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); 1317 1318 if (rc != -ENOENT) 1319 return rc; 1320 1321 rc = context_struct_to_string(p, &entry->context, scontext, 1322 scontext_len); 1323 if (!rc && scontext) 1324 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); 1325 return rc; 1326 } 1327 1328 #include "initial_sid_to_string.h" 1329 1330 int security_sidtab_hash_stats(char *page) 1331 { 1332 struct selinux_policy *policy; 1333 int rc; 1334 1335 if (!selinux_initialized()) { 1336 pr_err("SELinux: %s: called before initial load_policy\n", 1337 __func__); 1338 return -EINVAL; 1339 } 1340 1341 rcu_read_lock(); 1342 policy = rcu_dereference(selinux_state.policy); 1343 rc = sidtab_hash_stats(policy->sidtab, page); 1344 rcu_read_unlock(); 1345 1346 return rc; 1347 } 1348 1349 const char *security_get_initial_sid_context(u32 sid) 1350 { 1351 if (unlikely(sid > SECINITSID_NUM)) 1352 return NULL; 1353 return initial_sid_to_string[sid]; 1354 } 1355 1356 static int security_sid_to_context_core(u32 sid, char **scontext, 1357 u32 *scontext_len, int force, 1358 int only_invalid) 1359 { 1360 struct selinux_policy *policy; 1361 struct policydb *policydb; 1362 struct sidtab *sidtab; 1363 struct sidtab_entry *entry; 1364 int rc = 0; 1365 1366 if (scontext) 1367 *scontext = NULL; 1368 *scontext_len = 0; 1369 1370 if (!selinux_initialized()) { 1371 if (sid <= SECINITSID_NUM) { 1372 char *scontextp; 1373 const char *s; 1374 1375 /* 1376 * Before the policy is loaded, translate 1377 * SECINITSID_INIT to "kernel", because systemd and 1378 * libselinux < 2.6 take a getcon_raw() result that is 1379 * both non-null and not "kernel" to mean that a policy 1380 * is already loaded. 1381 */ 1382 if (sid == SECINITSID_INIT) 1383 sid = SECINITSID_KERNEL; 1384 1385 s = initial_sid_to_string[sid]; 1386 if (!s) 1387 return -EINVAL; 1388 *scontext_len = strlen(s) + 1; 1389 if (!scontext) 1390 return 0; 1391 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1392 if (!scontextp) 1393 return -ENOMEM; 1394 *scontext = scontextp; 1395 return 0; 1396 } 1397 pr_err("SELinux: %s: called before initial " 1398 "load_policy on unknown SID %d\n", __func__, sid); 1399 return -EINVAL; 1400 } 1401 rcu_read_lock(); 1402 policy = rcu_dereference(selinux_state.policy); 1403 policydb = &policy->policydb; 1404 sidtab = policy->sidtab; 1405 1406 if (force) 1407 entry = sidtab_search_entry_force(sidtab, sid); 1408 else 1409 entry = sidtab_search_entry(sidtab, sid); 1410 if (!entry) { 1411 pr_err("SELinux: %s: unrecognized SID %d\n", 1412 __func__, sid); 1413 rc = -EINVAL; 1414 goto out_unlock; 1415 } 1416 if (only_invalid && !entry->context.len) 1417 goto out_unlock; 1418 1419 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1420 scontext_len); 1421 1422 out_unlock: 1423 rcu_read_unlock(); 1424 return rc; 1425 1426 } 1427 1428 /** 1429 * security_sid_to_context - Obtain a context for a given SID. 1430 * @sid: security identifier, SID 1431 * @scontext: security context 1432 * @scontext_len: length in bytes 1433 * 1434 * Write the string representation of the context associated with @sid 1435 * into a dynamically allocated string of the correct size. Set @scontext 1436 * to point to this string and set @scontext_len to the length of the string. 1437 */ 1438 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1439 { 1440 return security_sid_to_context_core(sid, scontext, 1441 scontext_len, 0, 0); 1442 } 1443 1444 int security_sid_to_context_force(u32 sid, 1445 char **scontext, u32 *scontext_len) 1446 { 1447 return security_sid_to_context_core(sid, scontext, 1448 scontext_len, 1, 0); 1449 } 1450 1451 /** 1452 * security_sid_to_context_inval - Obtain a context for a given SID if it 1453 * is invalid. 1454 * @sid: security identifier, SID 1455 * @scontext: security context 1456 * @scontext_len: length in bytes 1457 * 1458 * Write the string representation of the context associated with @sid 1459 * into a dynamically allocated string of the correct size, but only if the 1460 * context is invalid in the current policy. Set @scontext to point to 1461 * this string (or NULL if the context is valid) and set @scontext_len to 1462 * the length of the string (or 0 if the context is valid). 1463 */ 1464 int security_sid_to_context_inval(u32 sid, 1465 char **scontext, u32 *scontext_len) 1466 { 1467 return security_sid_to_context_core(sid, scontext, 1468 scontext_len, 1, 1); 1469 } 1470 1471 /* 1472 * Caveat: Mutates scontext. 1473 */ 1474 static int string_to_context_struct(struct policydb *pol, 1475 struct sidtab *sidtabp, 1476 char *scontext, 1477 struct context *ctx, 1478 u32 def_sid) 1479 { 1480 struct role_datum *role; 1481 struct type_datum *typdatum; 1482 struct user_datum *usrdatum; 1483 char *scontextp, *p, oldc; 1484 int rc = 0; 1485 1486 context_init(ctx); 1487 1488 /* Parse the security context. */ 1489 1490 rc = -EINVAL; 1491 scontextp = scontext; 1492 1493 /* Extract the user. */ 1494 p = scontextp; 1495 while (*p && *p != ':') 1496 p++; 1497 1498 if (*p == 0) 1499 goto out; 1500 1501 *p++ = 0; 1502 1503 usrdatum = symtab_search(&pol->p_users, scontextp); 1504 if (!usrdatum) 1505 goto out; 1506 1507 ctx->user = usrdatum->value; 1508 1509 /* Extract role. */ 1510 scontextp = p; 1511 while (*p && *p != ':') 1512 p++; 1513 1514 if (*p == 0) 1515 goto out; 1516 1517 *p++ = 0; 1518 1519 role = symtab_search(&pol->p_roles, scontextp); 1520 if (!role) 1521 goto out; 1522 ctx->role = role->value; 1523 1524 /* Extract type. */ 1525 scontextp = p; 1526 while (*p && *p != ':') 1527 p++; 1528 oldc = *p; 1529 *p++ = 0; 1530 1531 typdatum = symtab_search(&pol->p_types, scontextp); 1532 if (!typdatum || typdatum->attribute) 1533 goto out; 1534 1535 ctx->type = typdatum->value; 1536 1537 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1538 if (rc) 1539 goto out; 1540 1541 /* Check the validity of the new context. */ 1542 rc = -EINVAL; 1543 if (!policydb_context_isvalid(pol, ctx)) 1544 goto out; 1545 rc = 0; 1546 out: 1547 if (rc) 1548 context_destroy(ctx); 1549 return rc; 1550 } 1551 1552 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1553 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1554 int force) 1555 { 1556 struct selinux_policy *policy; 1557 struct policydb *policydb; 1558 struct sidtab *sidtab; 1559 char *scontext2, *str = NULL; 1560 struct context context; 1561 int rc = 0; 1562 1563 /* An empty security context is never valid. */ 1564 if (!scontext_len) 1565 return -EINVAL; 1566 1567 /* Copy the string to allow changes and ensure a NUL terminator */ 1568 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1569 if (!scontext2) 1570 return -ENOMEM; 1571 1572 if (!selinux_initialized()) { 1573 u32 i; 1574 1575 for (i = 1; i < SECINITSID_NUM; i++) { 1576 const char *s = initial_sid_to_string[i]; 1577 1578 if (s && !strcmp(s, scontext2)) { 1579 *sid = i; 1580 goto out; 1581 } 1582 } 1583 *sid = SECINITSID_KERNEL; 1584 goto out; 1585 } 1586 *sid = SECSID_NULL; 1587 1588 if (force) { 1589 /* Save another copy for storing in uninterpreted form */ 1590 rc = -ENOMEM; 1591 str = kstrdup(scontext2, gfp_flags); 1592 if (!str) 1593 goto out; 1594 } 1595 retry: 1596 rcu_read_lock(); 1597 policy = rcu_dereference(selinux_state.policy); 1598 policydb = &policy->policydb; 1599 sidtab = policy->sidtab; 1600 rc = string_to_context_struct(policydb, sidtab, scontext2, 1601 &context, def_sid); 1602 if (rc == -EINVAL && force) { 1603 context.str = str; 1604 context.len = strlen(str) + 1; 1605 str = NULL; 1606 } else if (rc) 1607 goto out_unlock; 1608 rc = sidtab_context_to_sid(sidtab, &context, sid); 1609 if (rc == -ESTALE) { 1610 rcu_read_unlock(); 1611 if (context.str) { 1612 str = context.str; 1613 context.str = NULL; 1614 } 1615 context_destroy(&context); 1616 goto retry; 1617 } 1618 context_destroy(&context); 1619 out_unlock: 1620 rcu_read_unlock(); 1621 out: 1622 kfree(scontext2); 1623 kfree(str); 1624 return rc; 1625 } 1626 1627 /** 1628 * security_context_to_sid - Obtain a SID for a given security context. 1629 * @scontext: security context 1630 * @scontext_len: length in bytes 1631 * @sid: security identifier, SID 1632 * @gfp: context for the allocation 1633 * 1634 * Obtains a SID associated with the security context that 1635 * has the string representation specified by @scontext. 1636 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1637 * memory is available, or 0 on success. 1638 */ 1639 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1640 gfp_t gfp) 1641 { 1642 return security_context_to_sid_core(scontext, scontext_len, 1643 sid, SECSID_NULL, gfp, 0); 1644 } 1645 1646 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1647 { 1648 return security_context_to_sid(scontext, strlen(scontext), 1649 sid, gfp); 1650 } 1651 1652 /** 1653 * security_context_to_sid_default - Obtain a SID for a given security context, 1654 * falling back to specified default if needed. 1655 * 1656 * @scontext: security context 1657 * @scontext_len: length in bytes 1658 * @sid: security identifier, SID 1659 * @def_sid: default SID to assign on error 1660 * @gfp_flags: the allocator get-free-page (GFP) flags 1661 * 1662 * Obtains a SID associated with the security context that 1663 * has the string representation specified by @scontext. 1664 * The default SID is passed to the MLS layer to be used to allow 1665 * kernel labeling of the MLS field if the MLS field is not present 1666 * (for upgrading to MLS without full relabel). 1667 * Implicitly forces adding of the context even if it cannot be mapped yet. 1668 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1669 * memory is available, or 0 on success. 1670 */ 1671 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1672 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1673 { 1674 return security_context_to_sid_core(scontext, scontext_len, 1675 sid, def_sid, gfp_flags, 1); 1676 } 1677 1678 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1679 u32 *sid) 1680 { 1681 return security_context_to_sid_core(scontext, scontext_len, 1682 sid, SECSID_NULL, GFP_KERNEL, 1); 1683 } 1684 1685 static int compute_sid_handle_invalid_context( 1686 struct selinux_policy *policy, 1687 struct sidtab_entry *sentry, 1688 struct sidtab_entry *tentry, 1689 u16 tclass, 1690 struct context *newcontext) 1691 { 1692 struct policydb *policydb = &policy->policydb; 1693 struct sidtab *sidtab = policy->sidtab; 1694 char *s = NULL, *t = NULL, *n = NULL; 1695 u32 slen, tlen, nlen; 1696 struct audit_buffer *ab; 1697 1698 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) 1699 goto out; 1700 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) 1701 goto out; 1702 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1703 goto out; 1704 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); 1705 if (!ab) 1706 goto out; 1707 audit_log_format(ab, 1708 "op=security_compute_sid invalid_context="); 1709 /* no need to record the NUL with untrusted strings */ 1710 audit_log_n_untrustedstring(ab, n, nlen - 1); 1711 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1712 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1713 audit_log_end(ab); 1714 out: 1715 kfree(s); 1716 kfree(t); 1717 kfree(n); 1718 if (!enforcing_enabled()) 1719 return 0; 1720 return -EACCES; 1721 } 1722 1723 static void filename_compute_type(struct policydb *policydb, 1724 struct context *newcontext, 1725 u32 stype, u32 ttype, u16 tclass, 1726 const char *objname) 1727 { 1728 struct filename_trans_key ft; 1729 struct filename_trans_datum *datum; 1730 1731 /* 1732 * Most filename trans rules are going to live in specific directories 1733 * like /dev or /var/run. This bitmap will quickly skip rule searches 1734 * if the ttype does not contain any rules. 1735 */ 1736 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1737 return; 1738 1739 ft.ttype = ttype; 1740 ft.tclass = tclass; 1741 ft.name = objname; 1742 1743 datum = policydb_filenametr_search(policydb, &ft); 1744 while (datum) { 1745 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1746 newcontext->type = datum->otype; 1747 return; 1748 } 1749 datum = datum->next; 1750 } 1751 } 1752 1753 static int security_compute_sid(u32 ssid, 1754 u32 tsid, 1755 u16 orig_tclass, 1756 u16 specified, 1757 const char *objname, 1758 u32 *out_sid, 1759 bool kern) 1760 { 1761 struct selinux_policy *policy; 1762 struct policydb *policydb; 1763 struct sidtab *sidtab; 1764 struct class_datum *cladatum; 1765 struct context *scontext, *tcontext, newcontext; 1766 struct sidtab_entry *sentry, *tentry; 1767 struct avtab_key avkey; 1768 struct avtab_node *avnode, *node; 1769 u16 tclass; 1770 int rc = 0; 1771 bool sock; 1772 1773 if (!selinux_initialized()) { 1774 switch (orig_tclass) { 1775 case SECCLASS_PROCESS: /* kernel value */ 1776 *out_sid = ssid; 1777 break; 1778 default: 1779 *out_sid = tsid; 1780 break; 1781 } 1782 goto out; 1783 } 1784 1785 retry: 1786 cladatum = NULL; 1787 context_init(&newcontext); 1788 1789 rcu_read_lock(); 1790 1791 policy = rcu_dereference(selinux_state.policy); 1792 1793 if (kern) { 1794 tclass = unmap_class(&policy->map, orig_tclass); 1795 sock = security_is_socket_class(orig_tclass); 1796 } else { 1797 tclass = orig_tclass; 1798 sock = security_is_socket_class(map_class(&policy->map, 1799 tclass)); 1800 } 1801 1802 policydb = &policy->policydb; 1803 sidtab = policy->sidtab; 1804 1805 sentry = sidtab_search_entry(sidtab, ssid); 1806 if (!sentry) { 1807 pr_err("SELinux: %s: unrecognized SID %d\n", 1808 __func__, ssid); 1809 rc = -EINVAL; 1810 goto out_unlock; 1811 } 1812 tentry = sidtab_search_entry(sidtab, tsid); 1813 if (!tentry) { 1814 pr_err("SELinux: %s: unrecognized SID %d\n", 1815 __func__, tsid); 1816 rc = -EINVAL; 1817 goto out_unlock; 1818 } 1819 1820 scontext = &sentry->context; 1821 tcontext = &tentry->context; 1822 1823 if (tclass && tclass <= policydb->p_classes.nprim) 1824 cladatum = policydb->class_val_to_struct[tclass - 1]; 1825 1826 /* Set the user identity. */ 1827 switch (specified) { 1828 case AVTAB_TRANSITION: 1829 case AVTAB_CHANGE: 1830 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1831 newcontext.user = tcontext->user; 1832 } else { 1833 /* notice this gets both DEFAULT_SOURCE and unset */ 1834 /* Use the process user identity. */ 1835 newcontext.user = scontext->user; 1836 } 1837 break; 1838 case AVTAB_MEMBER: 1839 /* Use the related object owner. */ 1840 newcontext.user = tcontext->user; 1841 break; 1842 } 1843 1844 /* Set the role to default values. */ 1845 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1846 newcontext.role = scontext->role; 1847 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1848 newcontext.role = tcontext->role; 1849 } else { 1850 if ((tclass == policydb->process_class) || sock) 1851 newcontext.role = scontext->role; 1852 else 1853 newcontext.role = OBJECT_R_VAL; 1854 } 1855 1856 /* Set the type. 1857 * Look for a type transition/member/change rule. 1858 */ 1859 avkey.source_type = scontext->type; 1860 avkey.target_type = tcontext->type; 1861 avkey.target_class = tclass; 1862 avkey.specified = specified; 1863 avnode = avtab_search_node(&policydb->te_avtab, &avkey); 1864 1865 /* If no permanent rule, also check for enabled conditional rules */ 1866 if (!avnode) { 1867 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1868 for (; node; node = avtab_search_node_next(node, specified)) { 1869 if (node->key.specified & AVTAB_ENABLED) { 1870 avnode = node; 1871 break; 1872 } 1873 } 1874 } 1875 1876 /* If a permanent rule is found, use the type from 1877 * the type transition/member/change rule. Otherwise, 1878 * set the type to its default values. 1879 */ 1880 if (avnode) { 1881 newcontext.type = avnode->datum.u.data; 1882 } else if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1883 newcontext.type = scontext->type; 1884 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1885 newcontext.type = tcontext->type; 1886 } else { 1887 if ((tclass == policydb->process_class) || sock) { 1888 /* Use the type of process. */ 1889 newcontext.type = scontext->type; 1890 } else { 1891 /* Use the type of the related object. */ 1892 newcontext.type = tcontext->type; 1893 } 1894 } 1895 1896 /* if we have a objname this is a file trans check so check those rules */ 1897 if (objname) 1898 filename_compute_type(policydb, &newcontext, scontext->type, 1899 tcontext->type, tclass, objname); 1900 1901 /* Check for class-specific changes. */ 1902 if (specified & AVTAB_TRANSITION) { 1903 /* Look for a role transition rule. */ 1904 struct role_trans_datum *rtd; 1905 struct role_trans_key rtk = { 1906 .role = scontext->role, 1907 .type = tcontext->type, 1908 .tclass = tclass, 1909 }; 1910 1911 rtd = policydb_roletr_search(policydb, &rtk); 1912 if (rtd) 1913 newcontext.role = rtd->new_role; 1914 } 1915 1916 /* Set the MLS attributes. 1917 This is done last because it may allocate memory. */ 1918 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1919 &newcontext, sock); 1920 if (rc) 1921 goto out_unlock; 1922 1923 /* Check the validity of the context. */ 1924 if (!policydb_context_isvalid(policydb, &newcontext)) { 1925 rc = compute_sid_handle_invalid_context(policy, sentry, 1926 tentry, tclass, 1927 &newcontext); 1928 if (rc) 1929 goto out_unlock; 1930 } 1931 /* Obtain the sid for the context. */ 1932 if (context_equal(scontext, &newcontext)) 1933 *out_sid = ssid; 1934 else if (context_equal(tcontext, &newcontext)) 1935 *out_sid = tsid; 1936 else { 1937 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1938 if (rc == -ESTALE) { 1939 rcu_read_unlock(); 1940 context_destroy(&newcontext); 1941 goto retry; 1942 } 1943 } 1944 out_unlock: 1945 rcu_read_unlock(); 1946 context_destroy(&newcontext); 1947 out: 1948 return rc; 1949 } 1950 1951 /** 1952 * security_transition_sid - Compute the SID for a new subject/object. 1953 * @ssid: source security identifier 1954 * @tsid: target security identifier 1955 * @tclass: target security class 1956 * @qstr: object name 1957 * @out_sid: security identifier for new subject/object 1958 * 1959 * Compute a SID to use for labeling a new subject or object in the 1960 * class @tclass based on a SID pair (@ssid, @tsid). 1961 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1962 * if insufficient memory is available, or %0 if the new SID was 1963 * computed successfully. 1964 */ 1965 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1966 const struct qstr *qstr, u32 *out_sid) 1967 { 1968 return security_compute_sid(ssid, tsid, tclass, 1969 AVTAB_TRANSITION, 1970 qstr ? qstr->name : NULL, out_sid, true); 1971 } 1972 1973 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1974 const char *objname, u32 *out_sid) 1975 { 1976 return security_compute_sid(ssid, tsid, tclass, 1977 AVTAB_TRANSITION, 1978 objname, out_sid, false); 1979 } 1980 1981 /** 1982 * security_member_sid - Compute the SID for member selection. 1983 * @ssid: source security identifier 1984 * @tsid: target security identifier 1985 * @tclass: target security class 1986 * @out_sid: security identifier for selected member 1987 * 1988 * Compute a SID to use when selecting a member of a polyinstantiated 1989 * object of class @tclass based on a SID pair (@ssid, @tsid). 1990 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1991 * if insufficient memory is available, or %0 if the SID was 1992 * computed successfully. 1993 */ 1994 int security_member_sid(u32 ssid, 1995 u32 tsid, 1996 u16 tclass, 1997 u32 *out_sid) 1998 { 1999 return security_compute_sid(ssid, tsid, tclass, 2000 AVTAB_MEMBER, NULL, 2001 out_sid, false); 2002 } 2003 2004 /** 2005 * security_change_sid - Compute the SID for object relabeling. 2006 * @ssid: source security identifier 2007 * @tsid: target security identifier 2008 * @tclass: target security class 2009 * @out_sid: security identifier for selected member 2010 * 2011 * Compute a SID to use for relabeling an object of class @tclass 2012 * based on a SID pair (@ssid, @tsid). 2013 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 2014 * if insufficient memory is available, or %0 if the SID was 2015 * computed successfully. 2016 */ 2017 int security_change_sid(u32 ssid, 2018 u32 tsid, 2019 u16 tclass, 2020 u32 *out_sid) 2021 { 2022 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 2023 out_sid, false); 2024 } 2025 2026 static inline int convert_context_handle_invalid_context( 2027 struct policydb *policydb, 2028 struct context *context) 2029 { 2030 char *s; 2031 u32 len; 2032 2033 if (enforcing_enabled()) 2034 return -EINVAL; 2035 2036 if (!context_struct_to_string(policydb, context, &s, &len)) { 2037 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 2038 s); 2039 kfree(s); 2040 } 2041 return 0; 2042 } 2043 2044 /** 2045 * services_convert_context - Convert a security context across policies. 2046 * @args: populated convert_context_args struct 2047 * @oldc: original context 2048 * @newc: converted context 2049 * @gfp_flags: allocation flags 2050 * 2051 * Convert the values in the security context structure @oldc from the values 2052 * specified in the policy @args->oldp to the values specified in the policy 2053 * @args->newp, storing the new context in @newc, and verifying that the 2054 * context is valid under the new policy. 2055 */ 2056 int services_convert_context(struct convert_context_args *args, 2057 struct context *oldc, struct context *newc, 2058 gfp_t gfp_flags) 2059 { 2060 struct ocontext *oc; 2061 struct role_datum *role; 2062 struct type_datum *typdatum; 2063 struct user_datum *usrdatum; 2064 char *s; 2065 u32 len; 2066 int rc; 2067 2068 if (oldc->str) { 2069 s = kstrdup(oldc->str, gfp_flags); 2070 if (!s) 2071 return -ENOMEM; 2072 2073 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL); 2074 if (rc == -EINVAL) { 2075 /* 2076 * Retain string representation for later mapping. 2077 * 2078 * IMPORTANT: We need to copy the contents of oldc->str 2079 * back into s again because string_to_context_struct() 2080 * may have garbled it. 2081 */ 2082 memcpy(s, oldc->str, oldc->len); 2083 context_init(newc); 2084 newc->str = s; 2085 newc->len = oldc->len; 2086 return 0; 2087 } 2088 kfree(s); 2089 if (rc) { 2090 /* Other error condition, e.g. ENOMEM. */ 2091 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2092 oldc->str, -rc); 2093 return rc; 2094 } 2095 pr_info("SELinux: Context %s became valid (mapped).\n", 2096 oldc->str); 2097 return 0; 2098 } 2099 2100 context_init(newc); 2101 2102 /* Convert the user. */ 2103 usrdatum = symtab_search(&args->newp->p_users, 2104 sym_name(args->oldp, SYM_USERS, oldc->user - 1)); 2105 if (!usrdatum) 2106 goto bad; 2107 newc->user = usrdatum->value; 2108 2109 /* Convert the role. */ 2110 role = symtab_search(&args->newp->p_roles, 2111 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2112 if (!role) 2113 goto bad; 2114 newc->role = role->value; 2115 2116 /* Convert the type. */ 2117 typdatum = symtab_search(&args->newp->p_types, 2118 sym_name(args->oldp, SYM_TYPES, oldc->type - 1)); 2119 if (!typdatum) 2120 goto bad; 2121 newc->type = typdatum->value; 2122 2123 /* Convert the MLS fields if dealing with MLS policies */ 2124 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2125 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2126 if (rc) 2127 goto bad; 2128 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2129 /* 2130 * Switching between non-MLS and MLS policy: 2131 * ensure that the MLS fields of the context for all 2132 * existing entries in the sidtab are filled in with a 2133 * suitable default value, likely taken from one of the 2134 * initial SIDs. 2135 */ 2136 oc = args->newp->ocontexts[OCON_ISID]; 2137 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2138 oc = oc->next; 2139 if (!oc) { 2140 pr_err("SELinux: unable to look up" 2141 " the initial SIDs list\n"); 2142 goto bad; 2143 } 2144 rc = mls_range_set(newc, &oc->context[0].range); 2145 if (rc) 2146 goto bad; 2147 } 2148 2149 /* Check the validity of the new context. */ 2150 if (!policydb_context_isvalid(args->newp, newc)) { 2151 rc = convert_context_handle_invalid_context(args->oldp, oldc); 2152 if (rc) 2153 goto bad; 2154 } 2155 2156 return 0; 2157 bad: 2158 /* Map old representation to string and save it. */ 2159 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2160 if (rc) 2161 return rc; 2162 context_destroy(newc); 2163 newc->str = s; 2164 newc->len = len; 2165 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2166 newc->str); 2167 return 0; 2168 } 2169 2170 static void security_load_policycaps(struct selinux_policy *policy) 2171 { 2172 struct policydb *p; 2173 unsigned int i; 2174 struct ebitmap_node *node; 2175 2176 p = &policy->policydb; 2177 2178 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++) 2179 WRITE_ONCE(selinux_state.policycap[i], 2180 ebitmap_get_bit(&p->policycaps, i)); 2181 2182 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2183 pr_info("SELinux: policy capability %s=%d\n", 2184 selinux_policycap_names[i], 2185 ebitmap_get_bit(&p->policycaps, i)); 2186 2187 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2188 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2189 pr_info("SELinux: unknown policy capability %u\n", 2190 i); 2191 } 2192 } 2193 2194 static int security_preserve_bools(struct selinux_policy *oldpolicy, 2195 struct selinux_policy *newpolicy); 2196 2197 static void selinux_policy_free(struct selinux_policy *policy) 2198 { 2199 if (!policy) 2200 return; 2201 2202 sidtab_destroy(policy->sidtab); 2203 kfree(policy->map.mapping); 2204 policydb_destroy(&policy->policydb); 2205 kfree(policy->sidtab); 2206 kfree(policy); 2207 } 2208 2209 static void selinux_policy_cond_free(struct selinux_policy *policy) 2210 { 2211 cond_policydb_destroy_dup(&policy->policydb); 2212 kfree(policy); 2213 } 2214 2215 void selinux_policy_cancel(struct selinux_load_state *load_state) 2216 { 2217 struct selinux_state *state = &selinux_state; 2218 struct selinux_policy *oldpolicy; 2219 2220 oldpolicy = rcu_dereference_protected(state->policy, 2221 lockdep_is_held(&state->policy_mutex)); 2222 2223 sidtab_cancel_convert(oldpolicy->sidtab); 2224 selinux_policy_free(load_state->policy); 2225 kfree(load_state->convert_data); 2226 } 2227 2228 static void selinux_notify_policy_change(u32 seqno) 2229 { 2230 /* Flush external caches and notify userspace of policy load */ 2231 avc_ss_reset(seqno); 2232 selnl_notify_policyload(seqno); 2233 selinux_status_update_policyload(seqno); 2234 selinux_netlbl_cache_invalidate(); 2235 selinux_xfrm_notify_policyload(); 2236 selinux_ima_measure_state_locked(); 2237 } 2238 2239 void selinux_policy_commit(struct selinux_load_state *load_state) 2240 { 2241 struct selinux_state *state = &selinux_state; 2242 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2243 unsigned long flags; 2244 u32 seqno; 2245 2246 oldpolicy = rcu_dereference_protected(state->policy, 2247 lockdep_is_held(&state->policy_mutex)); 2248 2249 /* If switching between different policy types, log MLS status */ 2250 if (oldpolicy) { 2251 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2252 pr_info("SELinux: Disabling MLS support...\n"); 2253 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2254 pr_info("SELinux: Enabling MLS support...\n"); 2255 } 2256 2257 /* Set latest granting seqno for new policy. */ 2258 if (oldpolicy) 2259 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2260 else 2261 newpolicy->latest_granting = 1; 2262 seqno = newpolicy->latest_granting; 2263 2264 /* Install the new policy. */ 2265 if (oldpolicy) { 2266 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2267 rcu_assign_pointer(state->policy, newpolicy); 2268 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2269 } else { 2270 rcu_assign_pointer(state->policy, newpolicy); 2271 } 2272 2273 /* Load the policycaps from the new policy */ 2274 security_load_policycaps(newpolicy); 2275 2276 if (!selinux_initialized()) { 2277 /* 2278 * After first policy load, the security server is 2279 * marked as initialized and ready to handle requests and 2280 * any objects created prior to policy load are then labeled. 2281 */ 2282 selinux_mark_initialized(); 2283 selinux_complete_init(); 2284 } 2285 2286 /* Free the old policy */ 2287 synchronize_rcu(); 2288 selinux_policy_free(oldpolicy); 2289 kfree(load_state->convert_data); 2290 2291 /* Notify others of the policy change */ 2292 selinux_notify_policy_change(seqno); 2293 } 2294 2295 /** 2296 * security_load_policy - Load a security policy configuration. 2297 * @data: binary policy data 2298 * @len: length of data in bytes 2299 * @load_state: policy load state 2300 * 2301 * Load a new set of security policy configuration data, 2302 * validate it and convert the SID table as necessary. 2303 * This function will flush the access vector cache after 2304 * loading the new policy. 2305 */ 2306 int security_load_policy(void *data, size_t len, 2307 struct selinux_load_state *load_state) 2308 { 2309 struct selinux_state *state = &selinux_state; 2310 struct selinux_policy *newpolicy, *oldpolicy; 2311 struct selinux_policy_convert_data *convert_data; 2312 int rc = 0; 2313 struct policy_file file = { data, len }, *fp = &file; 2314 2315 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); 2316 if (!newpolicy) 2317 return -ENOMEM; 2318 2319 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); 2320 if (!newpolicy->sidtab) { 2321 rc = -ENOMEM; 2322 goto err_policy; 2323 } 2324 2325 rc = policydb_read(&newpolicy->policydb, fp); 2326 if (rc) 2327 goto err_sidtab; 2328 2329 newpolicy->policydb.len = len; 2330 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, 2331 &newpolicy->map); 2332 if (rc) 2333 goto err_policydb; 2334 2335 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); 2336 if (rc) { 2337 pr_err("SELinux: unable to load the initial SIDs\n"); 2338 goto err_mapping; 2339 } 2340 2341 if (!selinux_initialized()) { 2342 /* First policy load, so no need to preserve state from old policy */ 2343 load_state->policy = newpolicy; 2344 load_state->convert_data = NULL; 2345 return 0; 2346 } 2347 2348 oldpolicy = rcu_dereference_protected(state->policy, 2349 lockdep_is_held(&state->policy_mutex)); 2350 2351 /* Preserve active boolean values from the old policy */ 2352 rc = security_preserve_bools(oldpolicy, newpolicy); 2353 if (rc) { 2354 pr_err("SELinux: unable to preserve booleans\n"); 2355 goto err_free_isids; 2356 } 2357 2358 /* 2359 * Convert the internal representations of contexts 2360 * in the new SID table. 2361 */ 2362 2363 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2364 if (!convert_data) { 2365 rc = -ENOMEM; 2366 goto err_free_isids; 2367 } 2368 2369 convert_data->args.oldp = &oldpolicy->policydb; 2370 convert_data->args.newp = &newpolicy->policydb; 2371 2372 convert_data->sidtab_params.args = &convert_data->args; 2373 convert_data->sidtab_params.target = newpolicy->sidtab; 2374 2375 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); 2376 if (rc) { 2377 pr_err("SELinux: unable to convert the internal" 2378 " representation of contexts in the new SID" 2379 " table\n"); 2380 goto err_free_convert_data; 2381 } 2382 2383 load_state->policy = newpolicy; 2384 load_state->convert_data = convert_data; 2385 return 0; 2386 2387 err_free_convert_data: 2388 kfree(convert_data); 2389 err_free_isids: 2390 sidtab_destroy(newpolicy->sidtab); 2391 err_mapping: 2392 kfree(newpolicy->map.mapping); 2393 err_policydb: 2394 policydb_destroy(&newpolicy->policydb); 2395 err_sidtab: 2396 kfree(newpolicy->sidtab); 2397 err_policy: 2398 kfree(newpolicy); 2399 2400 return rc; 2401 } 2402 2403 /** 2404 * ocontext_to_sid - Helper to safely get sid for an ocontext 2405 * @sidtab: SID table 2406 * @c: ocontext structure 2407 * @index: index of the context entry (0 or 1) 2408 * @out_sid: pointer to the resulting SID value 2409 * 2410 * For all ocontexts except OCON_ISID the SID fields are populated 2411 * on-demand when needed. Since updating the SID value is an SMP-sensitive 2412 * operation, this helper must be used to do that safely. 2413 * 2414 * WARNING: This function may return -ESTALE, indicating that the caller 2415 * must retry the operation after re-acquiring the policy pointer! 2416 */ 2417 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, 2418 size_t index, u32 *out_sid) 2419 { 2420 int rc; 2421 u32 sid; 2422 2423 /* Ensure the associated sidtab entry is visible to this thread. */ 2424 sid = smp_load_acquire(&c->sid[index]); 2425 if (!sid) { 2426 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); 2427 if (rc) 2428 return rc; 2429 2430 /* 2431 * Ensure the new sidtab entry is visible to other threads 2432 * when they see the SID. 2433 */ 2434 smp_store_release(&c->sid[index], sid); 2435 } 2436 *out_sid = sid; 2437 return 0; 2438 } 2439 2440 /** 2441 * security_port_sid - Obtain the SID for a port. 2442 * @protocol: protocol number 2443 * @port: port number 2444 * @out_sid: security identifier 2445 */ 2446 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2447 { 2448 struct selinux_policy *policy; 2449 struct policydb *policydb; 2450 struct sidtab *sidtab; 2451 struct ocontext *c; 2452 int rc; 2453 2454 if (!selinux_initialized()) { 2455 *out_sid = SECINITSID_PORT; 2456 return 0; 2457 } 2458 2459 retry: 2460 rc = 0; 2461 rcu_read_lock(); 2462 policy = rcu_dereference(selinux_state.policy); 2463 policydb = &policy->policydb; 2464 sidtab = policy->sidtab; 2465 2466 c = policydb->ocontexts[OCON_PORT]; 2467 while (c) { 2468 if (c->u.port.protocol == protocol && 2469 c->u.port.low_port <= port && 2470 c->u.port.high_port >= port) 2471 break; 2472 c = c->next; 2473 } 2474 2475 if (c) { 2476 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2477 if (rc == -ESTALE) { 2478 rcu_read_unlock(); 2479 goto retry; 2480 } 2481 if (rc) 2482 goto out; 2483 } else { 2484 *out_sid = SECINITSID_PORT; 2485 } 2486 2487 out: 2488 rcu_read_unlock(); 2489 return rc; 2490 } 2491 2492 /** 2493 * security_ib_pkey_sid - Obtain the SID for a pkey. 2494 * @subnet_prefix: Subnet Prefix 2495 * @pkey_num: pkey number 2496 * @out_sid: security identifier 2497 */ 2498 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2499 { 2500 struct selinux_policy *policy; 2501 struct policydb *policydb; 2502 struct sidtab *sidtab; 2503 struct ocontext *c; 2504 int rc; 2505 2506 if (!selinux_initialized()) { 2507 *out_sid = SECINITSID_UNLABELED; 2508 return 0; 2509 } 2510 2511 retry: 2512 rc = 0; 2513 rcu_read_lock(); 2514 policy = rcu_dereference(selinux_state.policy); 2515 policydb = &policy->policydb; 2516 sidtab = policy->sidtab; 2517 2518 c = policydb->ocontexts[OCON_IBPKEY]; 2519 while (c) { 2520 if (c->u.ibpkey.low_pkey <= pkey_num && 2521 c->u.ibpkey.high_pkey >= pkey_num && 2522 c->u.ibpkey.subnet_prefix == subnet_prefix) 2523 break; 2524 2525 c = c->next; 2526 } 2527 2528 if (c) { 2529 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2530 if (rc == -ESTALE) { 2531 rcu_read_unlock(); 2532 goto retry; 2533 } 2534 if (rc) 2535 goto out; 2536 } else 2537 *out_sid = SECINITSID_UNLABELED; 2538 2539 out: 2540 rcu_read_unlock(); 2541 return rc; 2542 } 2543 2544 /** 2545 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2546 * @dev_name: device name 2547 * @port_num: port number 2548 * @out_sid: security identifier 2549 */ 2550 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) 2551 { 2552 struct selinux_policy *policy; 2553 struct policydb *policydb; 2554 struct sidtab *sidtab; 2555 struct ocontext *c; 2556 int rc; 2557 2558 if (!selinux_initialized()) { 2559 *out_sid = SECINITSID_UNLABELED; 2560 return 0; 2561 } 2562 2563 retry: 2564 rc = 0; 2565 rcu_read_lock(); 2566 policy = rcu_dereference(selinux_state.policy); 2567 policydb = &policy->policydb; 2568 sidtab = policy->sidtab; 2569 2570 c = policydb->ocontexts[OCON_IBENDPORT]; 2571 while (c) { 2572 if (c->u.ibendport.port == port_num && 2573 !strncmp(c->u.ibendport.dev_name, 2574 dev_name, 2575 IB_DEVICE_NAME_MAX)) 2576 break; 2577 2578 c = c->next; 2579 } 2580 2581 if (c) { 2582 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2583 if (rc == -ESTALE) { 2584 rcu_read_unlock(); 2585 goto retry; 2586 } 2587 if (rc) 2588 goto out; 2589 } else 2590 *out_sid = SECINITSID_UNLABELED; 2591 2592 out: 2593 rcu_read_unlock(); 2594 return rc; 2595 } 2596 2597 /** 2598 * security_netif_sid - Obtain the SID for a network interface. 2599 * @name: interface name 2600 * @if_sid: interface SID 2601 */ 2602 int security_netif_sid(const char *name, u32 *if_sid) 2603 { 2604 struct selinux_policy *policy; 2605 struct policydb *policydb; 2606 struct sidtab *sidtab; 2607 int rc; 2608 struct ocontext *c; 2609 bool wildcard_support; 2610 2611 if (!selinux_initialized()) { 2612 *if_sid = SECINITSID_NETIF; 2613 return 0; 2614 } 2615 2616 retry: 2617 rc = 0; 2618 rcu_read_lock(); 2619 policy = rcu_dereference(selinux_state.policy); 2620 policydb = &policy->policydb; 2621 sidtab = policy->sidtab; 2622 wildcard_support = ebitmap_get_bit(&policydb->policycaps, POLICYDB_CAP_NETIF_WILDCARD); 2623 2624 c = policydb->ocontexts[OCON_NETIF]; 2625 while (c) { 2626 if (wildcard_support) { 2627 if (match_wildcard(c->u.name, name)) 2628 break; 2629 } else { 2630 if (strcmp(c->u.name, name) == 0) 2631 break; 2632 } 2633 2634 c = c->next; 2635 } 2636 2637 if (c) { 2638 rc = ocontext_to_sid(sidtab, c, 0, if_sid); 2639 if (rc == -ESTALE) { 2640 rcu_read_unlock(); 2641 goto retry; 2642 } 2643 if (rc) 2644 goto out; 2645 } else 2646 *if_sid = SECINITSID_NETIF; 2647 2648 out: 2649 rcu_read_unlock(); 2650 return rc; 2651 } 2652 2653 static bool match_ipv6_addrmask(const u32 input[4], const u32 addr[4], const u32 mask[4]) 2654 { 2655 int i; 2656 2657 for (i = 0; i < 4; i++) 2658 if (addr[i] != (input[i] & mask[i])) 2659 return false; 2660 2661 return true; 2662 } 2663 2664 /** 2665 * security_node_sid - Obtain the SID for a node (host). 2666 * @domain: communication domain aka address family 2667 * @addrp: address 2668 * @addrlen: address length in bytes 2669 * @out_sid: security identifier 2670 */ 2671 int security_node_sid(u16 domain, 2672 const void *addrp, 2673 u32 addrlen, 2674 u32 *out_sid) 2675 { 2676 struct selinux_policy *policy; 2677 struct policydb *policydb; 2678 struct sidtab *sidtab; 2679 int rc; 2680 struct ocontext *c; 2681 2682 if (!selinux_initialized()) { 2683 *out_sid = SECINITSID_NODE; 2684 return 0; 2685 } 2686 2687 retry: 2688 rcu_read_lock(); 2689 policy = rcu_dereference(selinux_state.policy); 2690 policydb = &policy->policydb; 2691 sidtab = policy->sidtab; 2692 2693 switch (domain) { 2694 case AF_INET: { 2695 u32 addr; 2696 2697 rc = -EINVAL; 2698 if (addrlen != sizeof(u32)) 2699 goto out; 2700 2701 addr = *((const u32 *)addrp); 2702 2703 c = policydb->ocontexts[OCON_NODE]; 2704 while (c) { 2705 if (c->u.node.addr == (addr & c->u.node.mask)) 2706 break; 2707 c = c->next; 2708 } 2709 break; 2710 } 2711 2712 case AF_INET6: 2713 rc = -EINVAL; 2714 if (addrlen != sizeof(u64) * 2) 2715 goto out; 2716 c = policydb->ocontexts[OCON_NODE6]; 2717 while (c) { 2718 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2719 c->u.node6.mask)) 2720 break; 2721 c = c->next; 2722 } 2723 break; 2724 2725 default: 2726 rc = 0; 2727 *out_sid = SECINITSID_NODE; 2728 goto out; 2729 } 2730 2731 if (c) { 2732 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2733 if (rc == -ESTALE) { 2734 rcu_read_unlock(); 2735 goto retry; 2736 } 2737 if (rc) 2738 goto out; 2739 } else { 2740 *out_sid = SECINITSID_NODE; 2741 } 2742 2743 rc = 0; 2744 out: 2745 rcu_read_unlock(); 2746 return rc; 2747 } 2748 2749 #define SIDS_NEL 25 2750 2751 /** 2752 * security_get_user_sids - Obtain reachable SIDs for a user. 2753 * @fromsid: starting SID 2754 * @username: username 2755 * @sids: array of reachable SIDs for user 2756 * @nel: number of elements in @sids 2757 * 2758 * Generate the set of SIDs for legal security contexts 2759 * for a given user that can be reached by @fromsid. 2760 * Set *@sids to point to a dynamically allocated 2761 * array containing the set of SIDs. Set *@nel to the 2762 * number of elements in the array. 2763 */ 2764 2765 int security_get_user_sids(u32 fromsid, 2766 const char *username, 2767 u32 **sids, 2768 u32 *nel) 2769 { 2770 struct selinux_policy *policy; 2771 struct policydb *policydb; 2772 struct sidtab *sidtab; 2773 struct context *fromcon, usercon; 2774 u32 *mysids = NULL, *mysids2, sid; 2775 u32 i, j, mynel, maxnel = SIDS_NEL; 2776 struct user_datum *user; 2777 struct role_datum *role; 2778 struct ebitmap_node *rnode, *tnode; 2779 int rc; 2780 2781 *sids = NULL; 2782 *nel = 0; 2783 2784 if (!selinux_initialized()) 2785 return 0; 2786 2787 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2788 if (!mysids) 2789 return -ENOMEM; 2790 2791 retry: 2792 mynel = 0; 2793 rcu_read_lock(); 2794 policy = rcu_dereference(selinux_state.policy); 2795 policydb = &policy->policydb; 2796 sidtab = policy->sidtab; 2797 2798 context_init(&usercon); 2799 2800 rc = -EINVAL; 2801 fromcon = sidtab_search(sidtab, fromsid); 2802 if (!fromcon) 2803 goto out_unlock; 2804 2805 rc = -EINVAL; 2806 user = symtab_search(&policydb->p_users, username); 2807 if (!user) 2808 goto out_unlock; 2809 2810 usercon.user = user->value; 2811 2812 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2813 role = policydb->role_val_to_struct[i]; 2814 usercon.role = i + 1; 2815 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2816 usercon.type = j + 1; 2817 2818 if (mls_setup_user_range(policydb, fromcon, user, 2819 &usercon)) 2820 continue; 2821 2822 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2823 if (rc == -ESTALE) { 2824 rcu_read_unlock(); 2825 goto retry; 2826 } 2827 if (rc) 2828 goto out_unlock; 2829 if (mynel < maxnel) { 2830 mysids[mynel++] = sid; 2831 } else { 2832 rc = -ENOMEM; 2833 maxnel += SIDS_NEL; 2834 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2835 if (!mysids2) 2836 goto out_unlock; 2837 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2838 kfree(mysids); 2839 mysids = mysids2; 2840 mysids[mynel++] = sid; 2841 } 2842 } 2843 } 2844 rc = 0; 2845 out_unlock: 2846 rcu_read_unlock(); 2847 if (rc || !mynel) { 2848 kfree(mysids); 2849 return rc; 2850 } 2851 2852 rc = -ENOMEM; 2853 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2854 if (!mysids2) { 2855 kfree(mysids); 2856 return rc; 2857 } 2858 for (i = 0, j = 0; i < mynel; i++) { 2859 struct av_decision dummy_avd; 2860 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2861 SECCLASS_PROCESS, /* kernel value */ 2862 PROCESS__TRANSITION, AVC_STRICT, 2863 &dummy_avd); 2864 if (!rc) 2865 mysids2[j++] = mysids[i]; 2866 cond_resched(); 2867 } 2868 kfree(mysids); 2869 *sids = mysids2; 2870 *nel = j; 2871 return 0; 2872 } 2873 2874 /** 2875 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2876 * @policy: policy 2877 * @fstype: filesystem type 2878 * @path: path from root of mount 2879 * @orig_sclass: file security class 2880 * @sid: SID for path 2881 * 2882 * Obtain a SID to use for a file in a filesystem that 2883 * cannot support xattr or use a fixed labeling behavior like 2884 * transition SIDs or task SIDs. 2885 * 2886 * WARNING: This function may return -ESTALE, indicating that the caller 2887 * must retry the operation after re-acquiring the policy pointer! 2888 */ 2889 static inline int __security_genfs_sid(struct selinux_policy *policy, 2890 const char *fstype, 2891 const char *path, 2892 u16 orig_sclass, 2893 u32 *sid) 2894 { 2895 struct policydb *policydb = &policy->policydb; 2896 struct sidtab *sidtab = policy->sidtab; 2897 u16 sclass; 2898 struct genfs *genfs; 2899 struct ocontext *c; 2900 int cmp = 0; 2901 bool wildcard; 2902 2903 while (path[0] == '/' && path[1] == '/') 2904 path++; 2905 2906 sclass = unmap_class(&policy->map, orig_sclass); 2907 *sid = SECINITSID_UNLABELED; 2908 2909 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2910 cmp = strcmp(fstype, genfs->fstype); 2911 if (cmp <= 0) 2912 break; 2913 } 2914 2915 if (!genfs || cmp) 2916 return -ENOENT; 2917 2918 wildcard = ebitmap_get_bit(&policy->policydb.policycaps, 2919 POLICYDB_CAP_GENFS_SECLABEL_WILDCARD); 2920 for (c = genfs->head; c; c = c->next) { 2921 if (!c->v.sclass || sclass == c->v.sclass) { 2922 if (wildcard) { 2923 if (match_wildcard(c->u.name, path)) 2924 break; 2925 } else { 2926 size_t len = strlen(c->u.name); 2927 2928 if ((strncmp(c->u.name, path, len)) == 0) 2929 break; 2930 } 2931 } 2932 } 2933 2934 if (!c) 2935 return -ENOENT; 2936 2937 return ocontext_to_sid(sidtab, c, 0, sid); 2938 } 2939 2940 /** 2941 * security_genfs_sid - Obtain a SID for a file in a filesystem 2942 * @fstype: filesystem type 2943 * @path: path from root of mount 2944 * @orig_sclass: file security class 2945 * @sid: SID for path 2946 * 2947 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2948 * it afterward. 2949 */ 2950 int security_genfs_sid(const char *fstype, 2951 const char *path, 2952 u16 orig_sclass, 2953 u32 *sid) 2954 { 2955 struct selinux_policy *policy; 2956 int retval; 2957 2958 if (!selinux_initialized()) { 2959 *sid = SECINITSID_UNLABELED; 2960 return 0; 2961 } 2962 2963 do { 2964 rcu_read_lock(); 2965 policy = rcu_dereference(selinux_state.policy); 2966 retval = __security_genfs_sid(policy, fstype, path, 2967 orig_sclass, sid); 2968 rcu_read_unlock(); 2969 } while (retval == -ESTALE); 2970 return retval; 2971 } 2972 2973 int selinux_policy_genfs_sid(struct selinux_policy *policy, 2974 const char *fstype, 2975 const char *path, 2976 u16 orig_sclass, 2977 u32 *sid) 2978 { 2979 /* no lock required, policy is not yet accessible by other threads */ 2980 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2981 } 2982 2983 /** 2984 * security_fs_use - Determine how to handle labeling for a filesystem. 2985 * @sb: superblock in question 2986 */ 2987 int security_fs_use(struct super_block *sb) 2988 { 2989 struct selinux_policy *policy; 2990 struct policydb *policydb; 2991 struct sidtab *sidtab; 2992 int rc; 2993 struct ocontext *c; 2994 struct superblock_security_struct *sbsec = selinux_superblock(sb); 2995 const char *fstype = sb->s_type->name; 2996 2997 if (!selinux_initialized()) { 2998 sbsec->behavior = SECURITY_FS_USE_NONE; 2999 sbsec->sid = SECINITSID_UNLABELED; 3000 return 0; 3001 } 3002 3003 retry: 3004 rcu_read_lock(); 3005 policy = rcu_dereference(selinux_state.policy); 3006 policydb = &policy->policydb; 3007 sidtab = policy->sidtab; 3008 3009 c = policydb->ocontexts[OCON_FSUSE]; 3010 while (c) { 3011 if (strcmp(fstype, c->u.name) == 0) 3012 break; 3013 c = c->next; 3014 } 3015 3016 if (c) { 3017 sbsec->behavior = c->v.behavior; 3018 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); 3019 if (rc == -ESTALE) { 3020 rcu_read_unlock(); 3021 goto retry; 3022 } 3023 if (rc) 3024 goto out; 3025 } else { 3026 rc = __security_genfs_sid(policy, fstype, "/", 3027 SECCLASS_DIR, &sbsec->sid); 3028 if (rc == -ESTALE) { 3029 rcu_read_unlock(); 3030 goto retry; 3031 } 3032 if (rc) { 3033 sbsec->behavior = SECURITY_FS_USE_NONE; 3034 rc = 0; 3035 } else { 3036 sbsec->behavior = SECURITY_FS_USE_GENFS; 3037 } 3038 } 3039 3040 out: 3041 rcu_read_unlock(); 3042 return rc; 3043 } 3044 3045 int security_get_bools(struct selinux_policy *policy, 3046 u32 *len, char ***names, int **values) 3047 { 3048 struct policydb *policydb; 3049 u32 i; 3050 int rc; 3051 3052 policydb = &policy->policydb; 3053 3054 *names = NULL; 3055 *values = NULL; 3056 3057 rc = 0; 3058 *len = policydb->p_bools.nprim; 3059 if (!*len) 3060 goto out; 3061 3062 rc = -ENOMEM; 3063 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 3064 if (!*names) 3065 goto err; 3066 3067 rc = -ENOMEM; 3068 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 3069 if (!*values) 3070 goto err; 3071 3072 for (i = 0; i < *len; i++) { 3073 (*values)[i] = policydb->bool_val_to_struct[i]->state; 3074 3075 rc = -ENOMEM; 3076 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 3077 GFP_ATOMIC); 3078 if (!(*names)[i]) 3079 goto err; 3080 } 3081 rc = 0; 3082 out: 3083 return rc; 3084 err: 3085 if (*names) { 3086 for (i = 0; i < *len; i++) 3087 kfree((*names)[i]); 3088 kfree(*names); 3089 } 3090 kfree(*values); 3091 *len = 0; 3092 *names = NULL; 3093 *values = NULL; 3094 goto out; 3095 } 3096 3097 3098 int security_set_bools(u32 len, const int *values) 3099 { 3100 struct selinux_state *state = &selinux_state; 3101 struct selinux_policy *newpolicy, *oldpolicy; 3102 int rc; 3103 u32 i, seqno = 0; 3104 3105 if (!selinux_initialized()) 3106 return -EINVAL; 3107 3108 oldpolicy = rcu_dereference_protected(state->policy, 3109 lockdep_is_held(&state->policy_mutex)); 3110 3111 /* Consistency check on number of booleans, should never fail */ 3112 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) 3113 return -EINVAL; 3114 3115 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); 3116 if (!newpolicy) 3117 return -ENOMEM; 3118 3119 /* 3120 * Deep copy only the parts of the policydb that might be 3121 * modified as a result of changing booleans. 3122 */ 3123 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); 3124 if (rc) { 3125 kfree(newpolicy); 3126 return -ENOMEM; 3127 } 3128 3129 /* Update the boolean states in the copy */ 3130 for (i = 0; i < len; i++) { 3131 int new_state = !!values[i]; 3132 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; 3133 3134 if (new_state != old_state) { 3135 audit_log(audit_context(), GFP_ATOMIC, 3136 AUDIT_MAC_CONFIG_CHANGE, 3137 "bool=%s val=%d old_val=%d auid=%u ses=%u", 3138 sym_name(&newpolicy->policydb, SYM_BOOLS, i), 3139 new_state, 3140 old_state, 3141 from_kuid(&init_user_ns, audit_get_loginuid(current)), 3142 audit_get_sessionid(current)); 3143 newpolicy->policydb.bool_val_to_struct[i]->state = new_state; 3144 } 3145 } 3146 3147 /* Re-evaluate the conditional rules in the copy */ 3148 evaluate_cond_nodes(&newpolicy->policydb); 3149 3150 /* Set latest granting seqno for new policy */ 3151 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 3152 seqno = newpolicy->latest_granting; 3153 3154 /* Install the new policy */ 3155 rcu_assign_pointer(state->policy, newpolicy); 3156 3157 /* 3158 * Free the conditional portions of the old policydb 3159 * that were copied for the new policy, and the oldpolicy 3160 * structure itself but not what it references. 3161 */ 3162 synchronize_rcu(); 3163 selinux_policy_cond_free(oldpolicy); 3164 3165 /* Notify others of the policy change */ 3166 selinux_notify_policy_change(seqno); 3167 return 0; 3168 } 3169 3170 int security_get_bool_value(u32 index) 3171 { 3172 struct selinux_policy *policy; 3173 struct policydb *policydb; 3174 int rc; 3175 u32 len; 3176 3177 if (!selinux_initialized()) 3178 return 0; 3179 3180 rcu_read_lock(); 3181 policy = rcu_dereference(selinux_state.policy); 3182 policydb = &policy->policydb; 3183 3184 rc = -EFAULT; 3185 len = policydb->p_bools.nprim; 3186 if (index >= len) 3187 goto out; 3188 3189 rc = policydb->bool_val_to_struct[index]->state; 3190 out: 3191 rcu_read_unlock(); 3192 return rc; 3193 } 3194 3195 static int security_preserve_bools(struct selinux_policy *oldpolicy, 3196 struct selinux_policy *newpolicy) 3197 { 3198 int rc, *bvalues = NULL; 3199 char **bnames = NULL; 3200 struct cond_bool_datum *booldatum; 3201 u32 i, nbools = 0; 3202 3203 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); 3204 if (rc) 3205 goto out; 3206 for (i = 0; i < nbools; i++) { 3207 booldatum = symtab_search(&newpolicy->policydb.p_bools, 3208 bnames[i]); 3209 if (booldatum) 3210 booldatum->state = bvalues[i]; 3211 } 3212 evaluate_cond_nodes(&newpolicy->policydb); 3213 3214 out: 3215 if (bnames) { 3216 for (i = 0; i < nbools; i++) 3217 kfree(bnames[i]); 3218 } 3219 kfree(bnames); 3220 kfree(bvalues); 3221 return rc; 3222 } 3223 3224 /* 3225 * security_sid_mls_copy() - computes a new sid based on the given 3226 * sid and the mls portion of mls_sid. 3227 */ 3228 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 3229 { 3230 struct selinux_policy *policy; 3231 struct policydb *policydb; 3232 struct sidtab *sidtab; 3233 struct context *context1; 3234 struct context *context2; 3235 struct context newcon; 3236 char *s; 3237 u32 len; 3238 int rc; 3239 3240 if (!selinux_initialized()) { 3241 *new_sid = sid; 3242 return 0; 3243 } 3244 3245 retry: 3246 rc = 0; 3247 context_init(&newcon); 3248 3249 rcu_read_lock(); 3250 policy = rcu_dereference(selinux_state.policy); 3251 policydb = &policy->policydb; 3252 sidtab = policy->sidtab; 3253 3254 if (!policydb->mls_enabled) { 3255 *new_sid = sid; 3256 goto out_unlock; 3257 } 3258 3259 rc = -EINVAL; 3260 context1 = sidtab_search(sidtab, sid); 3261 if (!context1) { 3262 pr_err("SELinux: %s: unrecognized SID %d\n", 3263 __func__, sid); 3264 goto out_unlock; 3265 } 3266 3267 rc = -EINVAL; 3268 context2 = sidtab_search(sidtab, mls_sid); 3269 if (!context2) { 3270 pr_err("SELinux: %s: unrecognized SID %d\n", 3271 __func__, mls_sid); 3272 goto out_unlock; 3273 } 3274 3275 newcon.user = context1->user; 3276 newcon.role = context1->role; 3277 newcon.type = context1->type; 3278 rc = mls_context_cpy(&newcon, context2); 3279 if (rc) 3280 goto out_unlock; 3281 3282 /* Check the validity of the new context. */ 3283 if (!policydb_context_isvalid(policydb, &newcon)) { 3284 rc = convert_context_handle_invalid_context(policydb, 3285 &newcon); 3286 if (rc) { 3287 if (!context_struct_to_string(policydb, &newcon, &s, 3288 &len)) { 3289 struct audit_buffer *ab; 3290 3291 ab = audit_log_start(audit_context(), 3292 GFP_ATOMIC, 3293 AUDIT_SELINUX_ERR); 3294 audit_log_format(ab, 3295 "op=security_sid_mls_copy invalid_context="); 3296 /* don't record NUL with untrusted strings */ 3297 audit_log_n_untrustedstring(ab, s, len - 1); 3298 audit_log_end(ab); 3299 kfree(s); 3300 } 3301 goto out_unlock; 3302 } 3303 } 3304 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3305 if (rc == -ESTALE) { 3306 rcu_read_unlock(); 3307 context_destroy(&newcon); 3308 goto retry; 3309 } 3310 out_unlock: 3311 rcu_read_unlock(); 3312 context_destroy(&newcon); 3313 return rc; 3314 } 3315 3316 /** 3317 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3318 * @nlbl_sid: NetLabel SID 3319 * @nlbl_type: NetLabel labeling protocol type 3320 * @xfrm_sid: XFRM SID 3321 * @peer_sid: network peer sid 3322 * 3323 * Description: 3324 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3325 * resolved into a single SID it is returned via @peer_sid and the function 3326 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3327 * returns a negative value. A table summarizing the behavior is below: 3328 * 3329 * | function return | @sid 3330 * ------------------------------+-----------------+----------------- 3331 * no peer labels | 0 | SECSID_NULL 3332 * single peer label | 0 | <peer_label> 3333 * multiple, consistent labels | 0 | <peer_label> 3334 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3335 * 3336 */ 3337 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 3338 u32 xfrm_sid, 3339 u32 *peer_sid) 3340 { 3341 struct selinux_policy *policy; 3342 struct policydb *policydb; 3343 struct sidtab *sidtab; 3344 int rc; 3345 struct context *nlbl_ctx; 3346 struct context *xfrm_ctx; 3347 3348 *peer_sid = SECSID_NULL; 3349 3350 /* handle the common (which also happens to be the set of easy) cases 3351 * right away, these two if statements catch everything involving a 3352 * single or absent peer SID/label */ 3353 if (xfrm_sid == SECSID_NULL) { 3354 *peer_sid = nlbl_sid; 3355 return 0; 3356 } 3357 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3358 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3359 * is present */ 3360 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3361 *peer_sid = xfrm_sid; 3362 return 0; 3363 } 3364 3365 if (!selinux_initialized()) 3366 return 0; 3367 3368 rcu_read_lock(); 3369 policy = rcu_dereference(selinux_state.policy); 3370 policydb = &policy->policydb; 3371 sidtab = policy->sidtab; 3372 3373 /* 3374 * We don't need to check initialized here since the only way both 3375 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3376 * security server was initialized and state->initialized was true. 3377 */ 3378 if (!policydb->mls_enabled) { 3379 rc = 0; 3380 goto out; 3381 } 3382 3383 rc = -EINVAL; 3384 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3385 if (!nlbl_ctx) { 3386 pr_err("SELinux: %s: unrecognized SID %d\n", 3387 __func__, nlbl_sid); 3388 goto out; 3389 } 3390 rc = -EINVAL; 3391 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3392 if (!xfrm_ctx) { 3393 pr_err("SELinux: %s: unrecognized SID %d\n", 3394 __func__, xfrm_sid); 3395 goto out; 3396 } 3397 rc = (mls_context_equal(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3398 if (rc) 3399 goto out; 3400 3401 /* at present NetLabel SIDs/labels really only carry MLS 3402 * information so if the MLS portion of the NetLabel SID 3403 * matches the MLS portion of the labeled XFRM SID/label 3404 * then pass along the XFRM SID as it is the most 3405 * expressive */ 3406 *peer_sid = xfrm_sid; 3407 out: 3408 rcu_read_unlock(); 3409 return rc; 3410 } 3411 3412 static int get_classes_callback(void *k, void *d, void *args) 3413 { 3414 struct class_datum *datum = d; 3415 char *name = k, **classes = args; 3416 u32 value = datum->value - 1; 3417 3418 classes[value] = kstrdup(name, GFP_ATOMIC); 3419 if (!classes[value]) 3420 return -ENOMEM; 3421 3422 return 0; 3423 } 3424 3425 int security_get_classes(struct selinux_policy *policy, 3426 char ***classes, u32 *nclasses) 3427 { 3428 struct policydb *policydb; 3429 int rc; 3430 3431 policydb = &policy->policydb; 3432 3433 rc = -ENOMEM; 3434 *nclasses = policydb->p_classes.nprim; 3435 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3436 if (!*classes) 3437 goto out; 3438 3439 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3440 *classes); 3441 if (rc) { 3442 u32 i; 3443 3444 for (i = 0; i < *nclasses; i++) 3445 kfree((*classes)[i]); 3446 kfree(*classes); 3447 } 3448 3449 out: 3450 return rc; 3451 } 3452 3453 static int get_permissions_callback(void *k, void *d, void *args) 3454 { 3455 struct perm_datum *datum = d; 3456 char *name = k, **perms = args; 3457 u32 value = datum->value - 1; 3458 3459 perms[value] = kstrdup(name, GFP_ATOMIC); 3460 if (!perms[value]) 3461 return -ENOMEM; 3462 3463 return 0; 3464 } 3465 3466 int security_get_permissions(struct selinux_policy *policy, 3467 const char *class, char ***perms, u32 *nperms) 3468 { 3469 struct policydb *policydb; 3470 u32 i; 3471 int rc; 3472 struct class_datum *match; 3473 3474 policydb = &policy->policydb; 3475 3476 rc = -EINVAL; 3477 match = symtab_search(&policydb->p_classes, class); 3478 if (!match) { 3479 pr_err("SELinux: %s: unrecognized class %s\n", 3480 __func__, class); 3481 goto out; 3482 } 3483 3484 rc = -ENOMEM; 3485 *nperms = match->permissions.nprim; 3486 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3487 if (!*perms) 3488 goto out; 3489 3490 if (match->comdatum) { 3491 rc = hashtab_map(&match->comdatum->permissions.table, 3492 get_permissions_callback, *perms); 3493 if (rc) 3494 goto err; 3495 } 3496 3497 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3498 *perms); 3499 if (rc) 3500 goto err; 3501 3502 out: 3503 return rc; 3504 3505 err: 3506 for (i = 0; i < *nperms; i++) 3507 kfree((*perms)[i]); 3508 kfree(*perms); 3509 return rc; 3510 } 3511 3512 int security_get_reject_unknown(void) 3513 { 3514 struct selinux_policy *policy; 3515 int value; 3516 3517 if (!selinux_initialized()) 3518 return 0; 3519 3520 rcu_read_lock(); 3521 policy = rcu_dereference(selinux_state.policy); 3522 value = policy->policydb.reject_unknown; 3523 rcu_read_unlock(); 3524 return value; 3525 } 3526 3527 int security_get_allow_unknown(void) 3528 { 3529 struct selinux_policy *policy; 3530 int value; 3531 3532 if (!selinux_initialized()) 3533 return 0; 3534 3535 rcu_read_lock(); 3536 policy = rcu_dereference(selinux_state.policy); 3537 value = policy->policydb.allow_unknown; 3538 rcu_read_unlock(); 3539 return value; 3540 } 3541 3542 /** 3543 * security_policycap_supported - Check for a specific policy capability 3544 * @req_cap: capability 3545 * 3546 * Description: 3547 * This function queries the currently loaded policy to see if it supports the 3548 * capability specified by @req_cap. Returns true (1) if the capability is 3549 * supported, false (0) if it isn't supported. 3550 * 3551 */ 3552 int security_policycap_supported(unsigned int req_cap) 3553 { 3554 struct selinux_policy *policy; 3555 int rc; 3556 3557 if (!selinux_initialized()) 3558 return 0; 3559 3560 rcu_read_lock(); 3561 policy = rcu_dereference(selinux_state.policy); 3562 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3563 rcu_read_unlock(); 3564 3565 return rc; 3566 } 3567 3568 struct selinux_audit_rule { 3569 u32 au_seqno; 3570 struct context au_ctxt; 3571 }; 3572 3573 void selinux_audit_rule_free(void *vrule) 3574 { 3575 struct selinux_audit_rule *rule = vrule; 3576 3577 if (rule) { 3578 context_destroy(&rule->au_ctxt); 3579 kfree(rule); 3580 } 3581 } 3582 3583 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, 3584 gfp_t gfp) 3585 { 3586 struct selinux_state *state = &selinux_state; 3587 struct selinux_policy *policy; 3588 struct policydb *policydb; 3589 struct selinux_audit_rule *tmprule; 3590 struct role_datum *roledatum; 3591 struct type_datum *typedatum; 3592 struct user_datum *userdatum; 3593 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3594 int rc = 0; 3595 3596 *rule = NULL; 3597 3598 if (!selinux_initialized()) 3599 return -EOPNOTSUPP; 3600 3601 switch (field) { 3602 case AUDIT_SUBJ_USER: 3603 case AUDIT_SUBJ_ROLE: 3604 case AUDIT_SUBJ_TYPE: 3605 case AUDIT_OBJ_USER: 3606 case AUDIT_OBJ_ROLE: 3607 case AUDIT_OBJ_TYPE: 3608 /* only 'equals' and 'not equals' fit user, role, and type */ 3609 if (op != Audit_equal && op != Audit_not_equal) 3610 return -EINVAL; 3611 break; 3612 case AUDIT_SUBJ_SEN: 3613 case AUDIT_SUBJ_CLR: 3614 case AUDIT_OBJ_LEV_LOW: 3615 case AUDIT_OBJ_LEV_HIGH: 3616 /* we do not allow a range, indicated by the presence of '-' */ 3617 if (strchr(rulestr, '-')) 3618 return -EINVAL; 3619 break; 3620 default: 3621 /* only the above fields are valid */ 3622 return -EINVAL; 3623 } 3624 3625 tmprule = kzalloc(sizeof(struct selinux_audit_rule), gfp); 3626 if (!tmprule) 3627 return -ENOMEM; 3628 context_init(&tmprule->au_ctxt); 3629 3630 rcu_read_lock(); 3631 policy = rcu_dereference(state->policy); 3632 policydb = &policy->policydb; 3633 tmprule->au_seqno = policy->latest_granting; 3634 switch (field) { 3635 case AUDIT_SUBJ_USER: 3636 case AUDIT_OBJ_USER: 3637 userdatum = symtab_search(&policydb->p_users, rulestr); 3638 if (!userdatum) { 3639 rc = -EINVAL; 3640 goto err; 3641 } 3642 tmprule->au_ctxt.user = userdatum->value; 3643 break; 3644 case AUDIT_SUBJ_ROLE: 3645 case AUDIT_OBJ_ROLE: 3646 roledatum = symtab_search(&policydb->p_roles, rulestr); 3647 if (!roledatum) { 3648 rc = -EINVAL; 3649 goto err; 3650 } 3651 tmprule->au_ctxt.role = roledatum->value; 3652 break; 3653 case AUDIT_SUBJ_TYPE: 3654 case AUDIT_OBJ_TYPE: 3655 typedatum = symtab_search(&policydb->p_types, rulestr); 3656 if (!typedatum) { 3657 rc = -EINVAL; 3658 goto err; 3659 } 3660 tmprule->au_ctxt.type = typedatum->value; 3661 break; 3662 case AUDIT_SUBJ_SEN: 3663 case AUDIT_SUBJ_CLR: 3664 case AUDIT_OBJ_LEV_LOW: 3665 case AUDIT_OBJ_LEV_HIGH: 3666 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3667 GFP_ATOMIC); 3668 if (rc) 3669 goto err; 3670 break; 3671 } 3672 rcu_read_unlock(); 3673 3674 *rule = tmprule; 3675 return 0; 3676 3677 err: 3678 rcu_read_unlock(); 3679 selinux_audit_rule_free(tmprule); 3680 *rule = NULL; 3681 return rc; 3682 } 3683 3684 /* Check to see if the rule contains any selinux fields */ 3685 int selinux_audit_rule_known(struct audit_krule *rule) 3686 { 3687 u32 i; 3688 3689 for (i = 0; i < rule->field_count; i++) { 3690 struct audit_field *f = &rule->fields[i]; 3691 switch (f->type) { 3692 case AUDIT_SUBJ_USER: 3693 case AUDIT_SUBJ_ROLE: 3694 case AUDIT_SUBJ_TYPE: 3695 case AUDIT_SUBJ_SEN: 3696 case AUDIT_SUBJ_CLR: 3697 case AUDIT_OBJ_USER: 3698 case AUDIT_OBJ_ROLE: 3699 case AUDIT_OBJ_TYPE: 3700 case AUDIT_OBJ_LEV_LOW: 3701 case AUDIT_OBJ_LEV_HIGH: 3702 return 1; 3703 } 3704 } 3705 3706 return 0; 3707 } 3708 3709 int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule) 3710 { 3711 struct selinux_state *state = &selinux_state; 3712 struct selinux_policy *policy; 3713 struct context *ctxt; 3714 struct mls_level *level; 3715 struct selinux_audit_rule *rule = vrule; 3716 int match = 0; 3717 3718 if (unlikely(!rule)) { 3719 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3720 return -ENOENT; 3721 } 3722 3723 if (!selinux_initialized()) 3724 return 0; 3725 3726 rcu_read_lock(); 3727 3728 policy = rcu_dereference(state->policy); 3729 3730 if (rule->au_seqno < policy->latest_granting) { 3731 match = -ESTALE; 3732 goto out; 3733 } 3734 3735 ctxt = sidtab_search(policy->sidtab, prop->selinux.secid); 3736 if (unlikely(!ctxt)) { 3737 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3738 prop->selinux.secid); 3739 match = -ENOENT; 3740 goto out; 3741 } 3742 3743 /* a field/op pair that is not caught here will simply fall through 3744 without a match */ 3745 switch (field) { 3746 case AUDIT_SUBJ_USER: 3747 case AUDIT_OBJ_USER: 3748 switch (op) { 3749 case Audit_equal: 3750 match = (ctxt->user == rule->au_ctxt.user); 3751 break; 3752 case Audit_not_equal: 3753 match = (ctxt->user != rule->au_ctxt.user); 3754 break; 3755 } 3756 break; 3757 case AUDIT_SUBJ_ROLE: 3758 case AUDIT_OBJ_ROLE: 3759 switch (op) { 3760 case Audit_equal: 3761 match = (ctxt->role == rule->au_ctxt.role); 3762 break; 3763 case Audit_not_equal: 3764 match = (ctxt->role != rule->au_ctxt.role); 3765 break; 3766 } 3767 break; 3768 case AUDIT_SUBJ_TYPE: 3769 case AUDIT_OBJ_TYPE: 3770 switch (op) { 3771 case Audit_equal: 3772 match = (ctxt->type == rule->au_ctxt.type); 3773 break; 3774 case Audit_not_equal: 3775 match = (ctxt->type != rule->au_ctxt.type); 3776 break; 3777 } 3778 break; 3779 case AUDIT_SUBJ_SEN: 3780 case AUDIT_SUBJ_CLR: 3781 case AUDIT_OBJ_LEV_LOW: 3782 case AUDIT_OBJ_LEV_HIGH: 3783 level = ((field == AUDIT_SUBJ_SEN || 3784 field == AUDIT_OBJ_LEV_LOW) ? 3785 &ctxt->range.level[0] : &ctxt->range.level[1]); 3786 switch (op) { 3787 case Audit_equal: 3788 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3789 level); 3790 break; 3791 case Audit_not_equal: 3792 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3793 level); 3794 break; 3795 case Audit_lt: 3796 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3797 level) && 3798 !mls_level_eq(&rule->au_ctxt.range.level[0], 3799 level)); 3800 break; 3801 case Audit_le: 3802 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3803 level); 3804 break; 3805 case Audit_gt: 3806 match = (mls_level_dom(level, 3807 &rule->au_ctxt.range.level[0]) && 3808 !mls_level_eq(level, 3809 &rule->au_ctxt.range.level[0])); 3810 break; 3811 case Audit_ge: 3812 match = mls_level_dom(level, 3813 &rule->au_ctxt.range.level[0]); 3814 break; 3815 } 3816 } 3817 3818 out: 3819 rcu_read_unlock(); 3820 return match; 3821 } 3822 3823 static int aurule_avc_callback(u32 event) 3824 { 3825 if (event == AVC_CALLBACK_RESET) 3826 return audit_update_lsm_rules(); 3827 return 0; 3828 } 3829 3830 static int __init aurule_init(void) 3831 { 3832 int err; 3833 3834 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3835 if (err) 3836 panic("avc_add_callback() failed, error %d\n", err); 3837 3838 return err; 3839 } 3840 __initcall(aurule_init); 3841 3842 #ifdef CONFIG_NETLABEL 3843 /** 3844 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3845 * @secattr: the NetLabel packet security attributes 3846 * @sid: the SELinux SID 3847 * 3848 * Description: 3849 * Attempt to cache the context in @ctx, which was derived from the packet in 3850 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3851 * already been initialized. 3852 * 3853 */ 3854 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3855 u32 sid) 3856 { 3857 u32 *sid_cache; 3858 3859 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3860 if (sid_cache == NULL) 3861 return; 3862 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3863 if (secattr->cache == NULL) { 3864 kfree(sid_cache); 3865 return; 3866 } 3867 3868 *sid_cache = sid; 3869 secattr->cache->free = kfree; 3870 secattr->cache->data = sid_cache; 3871 secattr->flags |= NETLBL_SECATTR_CACHE; 3872 } 3873 3874 /** 3875 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3876 * @secattr: the NetLabel packet security attributes 3877 * @sid: the SELinux SID 3878 * 3879 * Description: 3880 * Convert the given NetLabel security attributes in @secattr into a 3881 * SELinux SID. If the @secattr field does not contain a full SELinux 3882 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3883 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3884 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3885 * conversion for future lookups. Returns zero on success, negative values on 3886 * failure. 3887 * 3888 */ 3889 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3890 u32 *sid) 3891 { 3892 struct selinux_policy *policy; 3893 struct policydb *policydb; 3894 struct sidtab *sidtab; 3895 int rc; 3896 struct context *ctx; 3897 struct context ctx_new; 3898 3899 if (!selinux_initialized()) { 3900 *sid = SECSID_NULL; 3901 return 0; 3902 } 3903 3904 retry: 3905 rc = 0; 3906 rcu_read_lock(); 3907 policy = rcu_dereference(selinux_state.policy); 3908 policydb = &policy->policydb; 3909 sidtab = policy->sidtab; 3910 3911 if (secattr->flags & NETLBL_SECATTR_CACHE) 3912 *sid = *(u32 *)secattr->cache->data; 3913 else if (secattr->flags & NETLBL_SECATTR_SECID) 3914 *sid = secattr->attr.secid; 3915 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3916 rc = -EIDRM; 3917 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3918 if (ctx == NULL) 3919 goto out; 3920 3921 context_init(&ctx_new); 3922 ctx_new.user = ctx->user; 3923 ctx_new.role = ctx->role; 3924 ctx_new.type = ctx->type; 3925 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3926 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3927 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3928 if (rc) 3929 goto out; 3930 } 3931 rc = -EIDRM; 3932 if (!mls_context_isvalid(policydb, &ctx_new)) { 3933 ebitmap_destroy(&ctx_new.range.level[0].cat); 3934 goto out; 3935 } 3936 3937 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3938 ebitmap_destroy(&ctx_new.range.level[0].cat); 3939 if (rc == -ESTALE) { 3940 rcu_read_unlock(); 3941 goto retry; 3942 } 3943 if (rc) 3944 goto out; 3945 3946 security_netlbl_cache_add(secattr, *sid); 3947 } else 3948 *sid = SECSID_NULL; 3949 3950 out: 3951 rcu_read_unlock(); 3952 return rc; 3953 } 3954 3955 /** 3956 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3957 * @sid: the SELinux SID 3958 * @secattr: the NetLabel packet security attributes 3959 * 3960 * Description: 3961 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3962 * Returns zero on success, negative values on failure. 3963 * 3964 */ 3965 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3966 { 3967 struct selinux_policy *policy; 3968 struct policydb *policydb; 3969 int rc; 3970 struct context *ctx; 3971 3972 if (!selinux_initialized()) 3973 return 0; 3974 3975 rcu_read_lock(); 3976 policy = rcu_dereference(selinux_state.policy); 3977 policydb = &policy->policydb; 3978 3979 rc = -ENOENT; 3980 ctx = sidtab_search(policy->sidtab, sid); 3981 if (ctx == NULL) 3982 goto out; 3983 3984 rc = -ENOMEM; 3985 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3986 GFP_ATOMIC); 3987 if (secattr->domain == NULL) 3988 goto out; 3989 3990 secattr->attr.secid = sid; 3991 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3992 mls_export_netlbl_lvl(policydb, ctx, secattr); 3993 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3994 out: 3995 rcu_read_unlock(); 3996 return rc; 3997 } 3998 #endif /* CONFIG_NETLABEL */ 3999 4000 /** 4001 * __security_read_policy - read the policy. 4002 * @policy: SELinux policy 4003 * @data: binary policy data 4004 * @len: length of data in bytes 4005 * 4006 */ 4007 static int __security_read_policy(struct selinux_policy *policy, 4008 void *data, size_t *len) 4009 { 4010 int rc; 4011 struct policy_file fp; 4012 4013 fp.data = data; 4014 fp.len = *len; 4015 4016 rc = policydb_write(&policy->policydb, &fp); 4017 if (rc) 4018 return rc; 4019 4020 *len = (unsigned long)fp.data - (unsigned long)data; 4021 return 0; 4022 } 4023 4024 /** 4025 * security_read_policy - read the policy. 4026 * @data: binary policy data 4027 * @len: length of data in bytes 4028 * 4029 */ 4030 int security_read_policy(void **data, size_t *len) 4031 { 4032 struct selinux_state *state = &selinux_state; 4033 struct selinux_policy *policy; 4034 4035 policy = rcu_dereference_protected( 4036 state->policy, lockdep_is_held(&state->policy_mutex)); 4037 if (!policy) 4038 return -EINVAL; 4039 4040 *len = policy->policydb.len; 4041 *data = vmalloc_user(*len); 4042 if (!*data) 4043 return -ENOMEM; 4044 4045 return __security_read_policy(policy, *data, len); 4046 } 4047 4048 /** 4049 * security_read_state_kernel - read the policy. 4050 * @data: binary policy data 4051 * @len: length of data in bytes 4052 * 4053 * Allocates kernel memory for reading SELinux policy. 4054 * This function is for internal use only and should not 4055 * be used for returning data to user space. 4056 * 4057 * This function must be called with policy_mutex held. 4058 */ 4059 int security_read_state_kernel(void **data, size_t *len) 4060 { 4061 int err; 4062 struct selinux_state *state = &selinux_state; 4063 struct selinux_policy *policy; 4064 4065 policy = rcu_dereference_protected( 4066 state->policy, lockdep_is_held(&state->policy_mutex)); 4067 if (!policy) 4068 return -EINVAL; 4069 4070 *len = policy->policydb.len; 4071 *data = vmalloc(*len); 4072 if (!*data) 4073 return -ENOMEM; 4074 4075 err = __security_read_policy(policy, *data, len); 4076 if (err) { 4077 vfree(*data); 4078 *data = NULL; 4079 *len = 0; 4080 } 4081 return err; 4082 } 4083