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