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