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