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 const 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 u16 specified; 977 978 switch (node->datum.u.xperms->specified) { 979 case AVTAB_XPERMS_IOCTLFUNCTION: 980 if (xpermd->base_perm != AVC_EXT_IOCTL || 981 xpermd->driver != node->datum.u.xperms->driver) 982 return; 983 break; 984 case AVTAB_XPERMS_IOCTLDRIVER: 985 if (xpermd->base_perm != AVC_EXT_IOCTL || 986 !security_xperm_test(node->datum.u.xperms->perms.p, 987 xpermd->driver)) 988 return; 989 break; 990 case AVTAB_XPERMS_NLMSG: 991 if (xpermd->base_perm != AVC_EXT_NLMSG || 992 xpermd->driver != node->datum.u.xperms->driver) 993 return; 994 break; 995 default: 996 pr_warn_once( 997 "SELinux: unknown extended permission (%u) will be ignored\n", 998 node->datum.u.xperms->specified); 999 return; 1000 } 1001 1002 specified = node->key.specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD); 1003 1004 if (specified == AVTAB_XPERMS_ALLOWED) { 1005 xpermd->used |= XPERMS_ALLOWED; 1006 update_xperms_extended_data(node->datum.u.xperms->specified, 1007 &node->datum.u.xperms->perms, 1008 xpermd->allowed); 1009 } else if (specified == AVTAB_XPERMS_AUDITALLOW) { 1010 xpermd->used |= XPERMS_AUDITALLOW; 1011 update_xperms_extended_data(node->datum.u.xperms->specified, 1012 &node->datum.u.xperms->perms, 1013 xpermd->auditallow); 1014 } else if (specified == AVTAB_XPERMS_DONTAUDIT) { 1015 xpermd->used |= XPERMS_DONTAUDIT; 1016 update_xperms_extended_data(node->datum.u.xperms->specified, 1017 &node->datum.u.xperms->perms, 1018 xpermd->dontaudit); 1019 } else { 1020 pr_warn_once("SELinux: unknown specified key (%u)\n", 1021 node->key.specified); 1022 } 1023 } 1024 1025 void security_compute_xperms_decision(u32 ssid, 1026 u32 tsid, 1027 u16 orig_tclass, 1028 u8 driver, 1029 u8 base_perm, 1030 struct extended_perms_decision *xpermd) 1031 { 1032 struct selinux_policy *policy; 1033 struct policydb *policydb; 1034 struct sidtab *sidtab; 1035 u16 tclass; 1036 struct context *scontext, *tcontext; 1037 struct avtab_key avkey; 1038 struct avtab_node *node; 1039 struct ebitmap *sattr, *tattr; 1040 struct ebitmap_node *snode, *tnode; 1041 unsigned int i, j; 1042 1043 xpermd->base_perm = base_perm; 1044 xpermd->driver = driver; 1045 xpermd->used = 0; 1046 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1047 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1048 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1049 1050 rcu_read_lock(); 1051 if (!selinux_initialized()) 1052 goto allow; 1053 1054 policy = rcu_dereference(selinux_state.policy); 1055 policydb = &policy->policydb; 1056 sidtab = policy->sidtab; 1057 1058 scontext = sidtab_search(sidtab, ssid); 1059 if (!scontext) { 1060 pr_err("SELinux: %s: unrecognized SID %d\n", 1061 __func__, ssid); 1062 goto out; 1063 } 1064 1065 tcontext = sidtab_search(sidtab, tsid); 1066 if (!tcontext) { 1067 pr_err("SELinux: %s: unrecognized SID %d\n", 1068 __func__, tsid); 1069 goto out; 1070 } 1071 1072 tclass = unmap_class(&policy->map, orig_tclass); 1073 if (unlikely(orig_tclass && !tclass)) { 1074 if (policydb->allow_unknown) 1075 goto allow; 1076 goto out; 1077 } 1078 1079 1080 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1081 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1082 goto out; 1083 } 1084 1085 avkey.target_class = tclass; 1086 avkey.specified = AVTAB_XPERMS; 1087 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 1088 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 1089 ebitmap_for_each_positive_bit(sattr, snode, i) { 1090 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1091 avkey.source_type = i + 1; 1092 avkey.target_type = j + 1; 1093 for (node = avtab_search_node(&policydb->te_avtab, 1094 &avkey); 1095 node; 1096 node = avtab_search_node_next(node, avkey.specified)) 1097 services_compute_xperms_decision(xpermd, node); 1098 1099 cond_compute_xperms(&policydb->te_cond_avtab, 1100 &avkey, xpermd); 1101 } 1102 } 1103 out: 1104 rcu_read_unlock(); 1105 return; 1106 allow: 1107 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1108 goto out; 1109 } 1110 1111 /** 1112 * security_compute_av - Compute access vector decisions. 1113 * @ssid: source security identifier 1114 * @tsid: target security identifier 1115 * @orig_tclass: target security class 1116 * @avd: access vector decisions 1117 * @xperms: extended permissions 1118 * 1119 * Compute a set of access vector decisions based on the 1120 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1121 */ 1122 void security_compute_av(u32 ssid, 1123 u32 tsid, 1124 u16 orig_tclass, 1125 struct av_decision *avd, 1126 struct extended_perms *xperms) 1127 { 1128 struct selinux_policy *policy; 1129 struct policydb *policydb; 1130 struct sidtab *sidtab; 1131 u16 tclass; 1132 struct context *scontext = NULL, *tcontext = NULL; 1133 1134 rcu_read_lock(); 1135 policy = rcu_dereference(selinux_state.policy); 1136 avd_init(policy, avd); 1137 xperms->len = 0; 1138 if (!selinux_initialized()) 1139 goto allow; 1140 1141 policydb = &policy->policydb; 1142 sidtab = policy->sidtab; 1143 1144 scontext = sidtab_search(sidtab, ssid); 1145 if (!scontext) { 1146 pr_err("SELinux: %s: unrecognized SID %d\n", 1147 __func__, ssid); 1148 goto out; 1149 } 1150 1151 /* permissive domain? */ 1152 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1153 avd->flags |= AVD_FLAGS_PERMISSIVE; 1154 1155 tcontext = sidtab_search(sidtab, tsid); 1156 if (!tcontext) { 1157 pr_err("SELinux: %s: unrecognized SID %d\n", 1158 __func__, tsid); 1159 goto out; 1160 } 1161 1162 tclass = unmap_class(&policy->map, orig_tclass); 1163 if (unlikely(orig_tclass && !tclass)) { 1164 if (policydb->allow_unknown) 1165 goto allow; 1166 goto out; 1167 } 1168 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1169 xperms); 1170 map_decision(&policy->map, orig_tclass, avd, 1171 policydb->allow_unknown); 1172 out: 1173 rcu_read_unlock(); 1174 return; 1175 allow: 1176 avd->allowed = 0xffffffff; 1177 goto out; 1178 } 1179 1180 void security_compute_av_user(u32 ssid, 1181 u32 tsid, 1182 u16 tclass, 1183 struct av_decision *avd) 1184 { 1185 struct selinux_policy *policy; 1186 struct policydb *policydb; 1187 struct sidtab *sidtab; 1188 struct context *scontext = NULL, *tcontext = NULL; 1189 1190 rcu_read_lock(); 1191 policy = rcu_dereference(selinux_state.policy); 1192 avd_init(policy, avd); 1193 if (!selinux_initialized()) 1194 goto allow; 1195 1196 policydb = &policy->policydb; 1197 sidtab = policy->sidtab; 1198 1199 scontext = sidtab_search(sidtab, ssid); 1200 if (!scontext) { 1201 pr_err("SELinux: %s: unrecognized SID %d\n", 1202 __func__, ssid); 1203 goto out; 1204 } 1205 1206 /* permissive domain? */ 1207 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1208 avd->flags |= AVD_FLAGS_PERMISSIVE; 1209 1210 tcontext = sidtab_search(sidtab, tsid); 1211 if (!tcontext) { 1212 pr_err("SELinux: %s: unrecognized SID %d\n", 1213 __func__, tsid); 1214 goto out; 1215 } 1216 1217 if (unlikely(!tclass)) { 1218 if (policydb->allow_unknown) 1219 goto allow; 1220 goto out; 1221 } 1222 1223 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1224 NULL); 1225 out: 1226 rcu_read_unlock(); 1227 return; 1228 allow: 1229 avd->allowed = 0xffffffff; 1230 goto out; 1231 } 1232 1233 /* 1234 * Write the security context string representation of 1235 * the context structure `context' into a dynamically 1236 * allocated string of the correct size. Set `*scontext' 1237 * to point to this string and set `*scontext_len' to 1238 * the length of the string. 1239 */ 1240 static int context_struct_to_string(struct policydb *p, 1241 struct context *context, 1242 char **scontext, u32 *scontext_len) 1243 { 1244 char *scontextp; 1245 1246 if (scontext) 1247 *scontext = NULL; 1248 *scontext_len = 0; 1249 1250 if (context->len) { 1251 *scontext_len = context->len; 1252 if (scontext) { 1253 *scontext = kstrdup(context->str, GFP_ATOMIC); 1254 if (!(*scontext)) 1255 return -ENOMEM; 1256 } 1257 return 0; 1258 } 1259 1260 /* Compute the size of the context. */ 1261 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1262 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1263 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1264 *scontext_len += mls_compute_context_len(p, context); 1265 1266 if (!scontext) 1267 return 0; 1268 1269 /* Allocate space for the context; caller must free this space. */ 1270 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1271 if (!scontextp) 1272 return -ENOMEM; 1273 *scontext = scontextp; 1274 1275 /* 1276 * Copy the user name, role name and type name into the context. 1277 */ 1278 scontextp += sprintf(scontextp, "%s:%s:%s", 1279 sym_name(p, SYM_USERS, context->user - 1), 1280 sym_name(p, SYM_ROLES, context->role - 1), 1281 sym_name(p, SYM_TYPES, context->type - 1)); 1282 1283 mls_sid_to_context(p, context, &scontextp); 1284 1285 *scontextp = 0; 1286 1287 return 0; 1288 } 1289 1290 static int sidtab_entry_to_string(struct policydb *p, 1291 struct sidtab *sidtab, 1292 struct sidtab_entry *entry, 1293 char **scontext, u32 *scontext_len) 1294 { 1295 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); 1296 1297 if (rc != -ENOENT) 1298 return rc; 1299 1300 rc = context_struct_to_string(p, &entry->context, scontext, 1301 scontext_len); 1302 if (!rc && scontext) 1303 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); 1304 return rc; 1305 } 1306 1307 #include "initial_sid_to_string.h" 1308 1309 int security_sidtab_hash_stats(char *page) 1310 { 1311 struct selinux_policy *policy; 1312 int rc; 1313 1314 if (!selinux_initialized()) { 1315 pr_err("SELinux: %s: called before initial load_policy\n", 1316 __func__); 1317 return -EINVAL; 1318 } 1319 1320 rcu_read_lock(); 1321 policy = rcu_dereference(selinux_state.policy); 1322 rc = sidtab_hash_stats(policy->sidtab, page); 1323 rcu_read_unlock(); 1324 1325 return rc; 1326 } 1327 1328 const char *security_get_initial_sid_context(u32 sid) 1329 { 1330 if (unlikely(sid > SECINITSID_NUM)) 1331 return NULL; 1332 return initial_sid_to_string[sid]; 1333 } 1334 1335 static int security_sid_to_context_core(u32 sid, char **scontext, 1336 u32 *scontext_len, int force, 1337 int only_invalid) 1338 { 1339 struct selinux_policy *policy; 1340 struct policydb *policydb; 1341 struct sidtab *sidtab; 1342 struct sidtab_entry *entry; 1343 int rc = 0; 1344 1345 if (scontext) 1346 *scontext = NULL; 1347 *scontext_len = 0; 1348 1349 if (!selinux_initialized()) { 1350 if (sid <= SECINITSID_NUM) { 1351 char *scontextp; 1352 const char *s; 1353 1354 /* 1355 * Before the policy is loaded, translate 1356 * SECINITSID_INIT to "kernel", because systemd and 1357 * libselinux < 2.6 take a getcon_raw() result that is 1358 * both non-null and not "kernel" to mean that a policy 1359 * is already loaded. 1360 */ 1361 if (sid == SECINITSID_INIT) 1362 sid = SECINITSID_KERNEL; 1363 1364 s = initial_sid_to_string[sid]; 1365 if (!s) 1366 return -EINVAL; 1367 *scontext_len = strlen(s) + 1; 1368 if (!scontext) 1369 return 0; 1370 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1371 if (!scontextp) 1372 return -ENOMEM; 1373 *scontext = scontextp; 1374 return 0; 1375 } 1376 pr_err("SELinux: %s: called before initial " 1377 "load_policy on unknown SID %d\n", __func__, sid); 1378 return -EINVAL; 1379 } 1380 rcu_read_lock(); 1381 policy = rcu_dereference(selinux_state.policy); 1382 policydb = &policy->policydb; 1383 sidtab = policy->sidtab; 1384 1385 if (force) 1386 entry = sidtab_search_entry_force(sidtab, sid); 1387 else 1388 entry = sidtab_search_entry(sidtab, sid); 1389 if (!entry) { 1390 pr_err("SELinux: %s: unrecognized SID %d\n", 1391 __func__, sid); 1392 rc = -EINVAL; 1393 goto out_unlock; 1394 } 1395 if (only_invalid && !entry->context.len) 1396 goto out_unlock; 1397 1398 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1399 scontext_len); 1400 1401 out_unlock: 1402 rcu_read_unlock(); 1403 return rc; 1404 1405 } 1406 1407 /** 1408 * security_sid_to_context - Obtain a context for a given SID. 1409 * @sid: security identifier, SID 1410 * @scontext: security context 1411 * @scontext_len: length in bytes 1412 * 1413 * Write the string representation of the context associated with @sid 1414 * into a dynamically allocated string of the correct size. Set @scontext 1415 * to point to this string and set @scontext_len to the length of the string. 1416 */ 1417 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1418 { 1419 return security_sid_to_context_core(sid, scontext, 1420 scontext_len, 0, 0); 1421 } 1422 1423 int security_sid_to_context_force(u32 sid, 1424 char **scontext, u32 *scontext_len) 1425 { 1426 return security_sid_to_context_core(sid, scontext, 1427 scontext_len, 1, 0); 1428 } 1429 1430 /** 1431 * security_sid_to_context_inval - Obtain a context for a given SID if it 1432 * is invalid. 1433 * @sid: security identifier, SID 1434 * @scontext: security context 1435 * @scontext_len: length in bytes 1436 * 1437 * Write the string representation of the context associated with @sid 1438 * into a dynamically allocated string of the correct size, but only if the 1439 * context is invalid in the current policy. Set @scontext to point to 1440 * this string (or NULL if the context is valid) and set @scontext_len to 1441 * the length of the string (or 0 if the context is valid). 1442 */ 1443 int security_sid_to_context_inval(u32 sid, 1444 char **scontext, u32 *scontext_len) 1445 { 1446 return security_sid_to_context_core(sid, scontext, 1447 scontext_len, 1, 1); 1448 } 1449 1450 /* 1451 * Caveat: Mutates scontext. 1452 */ 1453 static int string_to_context_struct(struct policydb *pol, 1454 struct sidtab *sidtabp, 1455 char *scontext, 1456 struct context *ctx, 1457 u32 def_sid) 1458 { 1459 struct role_datum *role; 1460 struct type_datum *typdatum; 1461 struct user_datum *usrdatum; 1462 char *scontextp, *p, oldc; 1463 int rc = 0; 1464 1465 context_init(ctx); 1466 1467 /* Parse the security context. */ 1468 1469 rc = -EINVAL; 1470 scontextp = scontext; 1471 1472 /* Extract the user. */ 1473 p = scontextp; 1474 while (*p && *p != ':') 1475 p++; 1476 1477 if (*p == 0) 1478 goto out; 1479 1480 *p++ = 0; 1481 1482 usrdatum = symtab_search(&pol->p_users, scontextp); 1483 if (!usrdatum) 1484 goto out; 1485 1486 ctx->user = usrdatum->value; 1487 1488 /* Extract role. */ 1489 scontextp = p; 1490 while (*p && *p != ':') 1491 p++; 1492 1493 if (*p == 0) 1494 goto out; 1495 1496 *p++ = 0; 1497 1498 role = symtab_search(&pol->p_roles, scontextp); 1499 if (!role) 1500 goto out; 1501 ctx->role = role->value; 1502 1503 /* Extract type. */ 1504 scontextp = p; 1505 while (*p && *p != ':') 1506 p++; 1507 oldc = *p; 1508 *p++ = 0; 1509 1510 typdatum = symtab_search(&pol->p_types, scontextp); 1511 if (!typdatum || typdatum->attribute) 1512 goto out; 1513 1514 ctx->type = typdatum->value; 1515 1516 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1517 if (rc) 1518 goto out; 1519 1520 /* Check the validity of the new context. */ 1521 rc = -EINVAL; 1522 if (!policydb_context_isvalid(pol, ctx)) 1523 goto out; 1524 rc = 0; 1525 out: 1526 if (rc) 1527 context_destroy(ctx); 1528 return rc; 1529 } 1530 1531 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1532 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1533 int force) 1534 { 1535 struct selinux_policy *policy; 1536 struct policydb *policydb; 1537 struct sidtab *sidtab; 1538 char *scontext2, *str = NULL; 1539 struct context context; 1540 int rc = 0; 1541 1542 /* An empty security context is never valid. */ 1543 if (!scontext_len) 1544 return -EINVAL; 1545 1546 /* Copy the string to allow changes and ensure a NUL terminator */ 1547 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1548 if (!scontext2) 1549 return -ENOMEM; 1550 1551 if (!selinux_initialized()) { 1552 u32 i; 1553 1554 for (i = 1; i < SECINITSID_NUM; i++) { 1555 const char *s = initial_sid_to_string[i]; 1556 1557 if (s && !strcmp(s, scontext2)) { 1558 *sid = i; 1559 goto out; 1560 } 1561 } 1562 *sid = SECINITSID_KERNEL; 1563 goto out; 1564 } 1565 *sid = SECSID_NULL; 1566 1567 if (force) { 1568 /* Save another copy for storing in uninterpreted form */ 1569 rc = -ENOMEM; 1570 str = kstrdup(scontext2, gfp_flags); 1571 if (!str) 1572 goto out; 1573 } 1574 retry: 1575 rcu_read_lock(); 1576 policy = rcu_dereference(selinux_state.policy); 1577 policydb = &policy->policydb; 1578 sidtab = policy->sidtab; 1579 rc = string_to_context_struct(policydb, sidtab, scontext2, 1580 &context, def_sid); 1581 if (rc == -EINVAL && force) { 1582 context.str = str; 1583 context.len = strlen(str) + 1; 1584 str = NULL; 1585 } else if (rc) 1586 goto out_unlock; 1587 rc = sidtab_context_to_sid(sidtab, &context, sid); 1588 if (rc == -ESTALE) { 1589 rcu_read_unlock(); 1590 if (context.str) { 1591 str = context.str; 1592 context.str = NULL; 1593 } 1594 context_destroy(&context); 1595 goto retry; 1596 } 1597 context_destroy(&context); 1598 out_unlock: 1599 rcu_read_unlock(); 1600 out: 1601 kfree(scontext2); 1602 kfree(str); 1603 return rc; 1604 } 1605 1606 /** 1607 * security_context_to_sid - Obtain a SID for a given security context. 1608 * @scontext: security context 1609 * @scontext_len: length in bytes 1610 * @sid: security identifier, SID 1611 * @gfp: context for the allocation 1612 * 1613 * Obtains a SID associated with the security context that 1614 * has the string representation specified by @scontext. 1615 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1616 * memory is available, or 0 on success. 1617 */ 1618 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1619 gfp_t gfp) 1620 { 1621 return security_context_to_sid_core(scontext, scontext_len, 1622 sid, SECSID_NULL, gfp, 0); 1623 } 1624 1625 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1626 { 1627 return security_context_to_sid(scontext, strlen(scontext), 1628 sid, gfp); 1629 } 1630 1631 /** 1632 * security_context_to_sid_default - Obtain a SID for a given security context, 1633 * falling back to specified default if needed. 1634 * 1635 * @scontext: security context 1636 * @scontext_len: length in bytes 1637 * @sid: security identifier, SID 1638 * @def_sid: default SID to assign on error 1639 * @gfp_flags: the allocator get-free-page (GFP) flags 1640 * 1641 * Obtains a SID associated with the security context that 1642 * has the string representation specified by @scontext. 1643 * The default SID is passed to the MLS layer to be used to allow 1644 * kernel labeling of the MLS field if the MLS field is not present 1645 * (for upgrading to MLS without full relabel). 1646 * Implicitly forces adding of the context even if it cannot be mapped yet. 1647 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1648 * memory is available, or 0 on success. 1649 */ 1650 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1651 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1652 { 1653 return security_context_to_sid_core(scontext, scontext_len, 1654 sid, def_sid, gfp_flags, 1); 1655 } 1656 1657 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1658 u32 *sid) 1659 { 1660 return security_context_to_sid_core(scontext, scontext_len, 1661 sid, SECSID_NULL, GFP_KERNEL, 1); 1662 } 1663 1664 static int compute_sid_handle_invalid_context( 1665 struct selinux_policy *policy, 1666 struct sidtab_entry *sentry, 1667 struct sidtab_entry *tentry, 1668 u16 tclass, 1669 struct context *newcontext) 1670 { 1671 struct policydb *policydb = &policy->policydb; 1672 struct sidtab *sidtab = policy->sidtab; 1673 char *s = NULL, *t = NULL, *n = NULL; 1674 u32 slen, tlen, nlen; 1675 struct audit_buffer *ab; 1676 1677 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) 1678 goto out; 1679 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) 1680 goto out; 1681 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1682 goto out; 1683 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); 1684 if (!ab) 1685 goto out; 1686 audit_log_format(ab, 1687 "op=security_compute_sid invalid_context="); 1688 /* no need to record the NUL with untrusted strings */ 1689 audit_log_n_untrustedstring(ab, n, nlen - 1); 1690 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1691 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1692 audit_log_end(ab); 1693 out: 1694 kfree(s); 1695 kfree(t); 1696 kfree(n); 1697 if (!enforcing_enabled()) 1698 return 0; 1699 return -EACCES; 1700 } 1701 1702 static void filename_compute_type(struct policydb *policydb, 1703 struct context *newcontext, 1704 u32 stype, u32 ttype, u16 tclass, 1705 const char *objname) 1706 { 1707 struct filename_trans_key ft; 1708 struct filename_trans_datum *datum; 1709 1710 /* 1711 * Most filename trans rules are going to live in specific directories 1712 * like /dev or /var/run. This bitmap will quickly skip rule searches 1713 * if the ttype does not contain any rules. 1714 */ 1715 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1716 return; 1717 1718 ft.ttype = ttype; 1719 ft.tclass = tclass; 1720 ft.name = objname; 1721 1722 datum = policydb_filenametr_search(policydb, &ft); 1723 while (datum) { 1724 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1725 newcontext->type = datum->otype; 1726 return; 1727 } 1728 datum = datum->next; 1729 } 1730 } 1731 1732 static int security_compute_sid(u32 ssid, 1733 u32 tsid, 1734 u16 orig_tclass, 1735 u16 specified, 1736 const char *objname, 1737 u32 *out_sid, 1738 bool kern) 1739 { 1740 struct selinux_policy *policy; 1741 struct policydb *policydb; 1742 struct sidtab *sidtab; 1743 struct class_datum *cladatum; 1744 struct context *scontext, *tcontext, newcontext; 1745 struct sidtab_entry *sentry, *tentry; 1746 struct avtab_key avkey; 1747 struct avtab_node *avnode, *node; 1748 u16 tclass; 1749 int rc = 0; 1750 bool sock; 1751 1752 if (!selinux_initialized()) { 1753 switch (orig_tclass) { 1754 case SECCLASS_PROCESS: /* kernel value */ 1755 *out_sid = ssid; 1756 break; 1757 default: 1758 *out_sid = tsid; 1759 break; 1760 } 1761 goto out; 1762 } 1763 1764 retry: 1765 cladatum = NULL; 1766 context_init(&newcontext); 1767 1768 rcu_read_lock(); 1769 1770 policy = rcu_dereference(selinux_state.policy); 1771 1772 if (kern) { 1773 tclass = unmap_class(&policy->map, orig_tclass); 1774 sock = security_is_socket_class(orig_tclass); 1775 } else { 1776 tclass = orig_tclass; 1777 sock = security_is_socket_class(map_class(&policy->map, 1778 tclass)); 1779 } 1780 1781 policydb = &policy->policydb; 1782 sidtab = policy->sidtab; 1783 1784 sentry = sidtab_search_entry(sidtab, ssid); 1785 if (!sentry) { 1786 pr_err("SELinux: %s: unrecognized SID %d\n", 1787 __func__, ssid); 1788 rc = -EINVAL; 1789 goto out_unlock; 1790 } 1791 tentry = sidtab_search_entry(sidtab, tsid); 1792 if (!tentry) { 1793 pr_err("SELinux: %s: unrecognized SID %d\n", 1794 __func__, tsid); 1795 rc = -EINVAL; 1796 goto out_unlock; 1797 } 1798 1799 scontext = &sentry->context; 1800 tcontext = &tentry->context; 1801 1802 if (tclass && tclass <= policydb->p_classes.nprim) 1803 cladatum = policydb->class_val_to_struct[tclass - 1]; 1804 1805 /* Set the user identity. */ 1806 switch (specified) { 1807 case AVTAB_TRANSITION: 1808 case AVTAB_CHANGE: 1809 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1810 newcontext.user = tcontext->user; 1811 } else { 1812 /* notice this gets both DEFAULT_SOURCE and unset */ 1813 /* Use the process user identity. */ 1814 newcontext.user = scontext->user; 1815 } 1816 break; 1817 case AVTAB_MEMBER: 1818 /* Use the related object owner. */ 1819 newcontext.user = tcontext->user; 1820 break; 1821 } 1822 1823 /* Set the role to default values. */ 1824 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1825 newcontext.role = scontext->role; 1826 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1827 newcontext.role = tcontext->role; 1828 } else { 1829 if ((tclass == policydb->process_class) || sock) 1830 newcontext.role = scontext->role; 1831 else 1832 newcontext.role = OBJECT_R_VAL; 1833 } 1834 1835 /* Set the type. 1836 * Look for a type transition/member/change rule. 1837 */ 1838 avkey.source_type = scontext->type; 1839 avkey.target_type = tcontext->type; 1840 avkey.target_class = tclass; 1841 avkey.specified = specified; 1842 avnode = avtab_search_node(&policydb->te_avtab, &avkey); 1843 1844 /* If no permanent rule, also check for enabled conditional rules */ 1845 if (!avnode) { 1846 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1847 for (; node; node = avtab_search_node_next(node, specified)) { 1848 if (node->key.specified & AVTAB_ENABLED) { 1849 avnode = node; 1850 break; 1851 } 1852 } 1853 } 1854 1855 /* If a permanent rule is found, use the type from 1856 * the type transition/member/change rule. Otherwise, 1857 * set the type to its default values. 1858 */ 1859 if (avnode) { 1860 newcontext.type = avnode->datum.u.data; 1861 } else if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1862 newcontext.type = scontext->type; 1863 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1864 newcontext.type = tcontext->type; 1865 } else { 1866 if ((tclass == policydb->process_class) || sock) { 1867 /* Use the type of process. */ 1868 newcontext.type = scontext->type; 1869 } else { 1870 /* Use the type of the related object. */ 1871 newcontext.type = tcontext->type; 1872 } 1873 } 1874 1875 /* if we have a objname this is a file trans check so check those rules */ 1876 if (objname) 1877 filename_compute_type(policydb, &newcontext, scontext->type, 1878 tcontext->type, tclass, objname); 1879 1880 /* Check for class-specific changes. */ 1881 if (specified & AVTAB_TRANSITION) { 1882 /* Look for a role transition rule. */ 1883 struct role_trans_datum *rtd; 1884 struct role_trans_key rtk = { 1885 .role = scontext->role, 1886 .type = tcontext->type, 1887 .tclass = tclass, 1888 }; 1889 1890 rtd = policydb_roletr_search(policydb, &rtk); 1891 if (rtd) 1892 newcontext.role = rtd->new_role; 1893 } 1894 1895 /* Set the MLS attributes. 1896 This is done last because it may allocate memory. */ 1897 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1898 &newcontext, sock); 1899 if (rc) 1900 goto out_unlock; 1901 1902 /* Check the validity of the context. */ 1903 if (!policydb_context_isvalid(policydb, &newcontext)) { 1904 rc = compute_sid_handle_invalid_context(policy, sentry, 1905 tentry, tclass, 1906 &newcontext); 1907 if (rc) 1908 goto out_unlock; 1909 } 1910 /* Obtain the sid for the context. */ 1911 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1912 if (rc == -ESTALE) { 1913 rcu_read_unlock(); 1914 context_destroy(&newcontext); 1915 goto retry; 1916 } 1917 out_unlock: 1918 rcu_read_unlock(); 1919 context_destroy(&newcontext); 1920 out: 1921 return rc; 1922 } 1923 1924 /** 1925 * security_transition_sid - Compute the SID for a new subject/object. 1926 * @ssid: source security identifier 1927 * @tsid: target security identifier 1928 * @tclass: target security class 1929 * @qstr: object name 1930 * @out_sid: security identifier for new subject/object 1931 * 1932 * Compute a SID to use for labeling a new subject or object in the 1933 * class @tclass based on a SID pair (@ssid, @tsid). 1934 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1935 * if insufficient memory is available, or %0 if the new SID was 1936 * computed successfully. 1937 */ 1938 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1939 const struct qstr *qstr, u32 *out_sid) 1940 { 1941 return security_compute_sid(ssid, tsid, tclass, 1942 AVTAB_TRANSITION, 1943 qstr ? qstr->name : NULL, out_sid, true); 1944 } 1945 1946 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1947 const char *objname, u32 *out_sid) 1948 { 1949 return security_compute_sid(ssid, tsid, tclass, 1950 AVTAB_TRANSITION, 1951 objname, out_sid, false); 1952 } 1953 1954 /** 1955 * security_member_sid - Compute the SID for member selection. 1956 * @ssid: source security identifier 1957 * @tsid: target security identifier 1958 * @tclass: target security class 1959 * @out_sid: security identifier for selected member 1960 * 1961 * Compute a SID to use when selecting a member of a polyinstantiated 1962 * object of class @tclass based on a SID pair (@ssid, @tsid). 1963 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1964 * if insufficient memory is available, or %0 if the SID was 1965 * computed successfully. 1966 */ 1967 int security_member_sid(u32 ssid, 1968 u32 tsid, 1969 u16 tclass, 1970 u32 *out_sid) 1971 { 1972 return security_compute_sid(ssid, tsid, tclass, 1973 AVTAB_MEMBER, NULL, 1974 out_sid, false); 1975 } 1976 1977 /** 1978 * security_change_sid - Compute the SID for object relabeling. 1979 * @ssid: source security identifier 1980 * @tsid: target security identifier 1981 * @tclass: target security class 1982 * @out_sid: security identifier for selected member 1983 * 1984 * Compute a SID to use for relabeling an object of class @tclass 1985 * based on a SID pair (@ssid, @tsid). 1986 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1987 * if insufficient memory is available, or %0 if the SID was 1988 * computed successfully. 1989 */ 1990 int security_change_sid(u32 ssid, 1991 u32 tsid, 1992 u16 tclass, 1993 u32 *out_sid) 1994 { 1995 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1996 out_sid, false); 1997 } 1998 1999 static inline int convert_context_handle_invalid_context( 2000 struct policydb *policydb, 2001 struct context *context) 2002 { 2003 char *s; 2004 u32 len; 2005 2006 if (enforcing_enabled()) 2007 return -EINVAL; 2008 2009 if (!context_struct_to_string(policydb, context, &s, &len)) { 2010 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 2011 s); 2012 kfree(s); 2013 } 2014 return 0; 2015 } 2016 2017 /** 2018 * services_convert_context - Convert a security context across policies. 2019 * @args: populated convert_context_args struct 2020 * @oldc: original context 2021 * @newc: converted context 2022 * @gfp_flags: allocation flags 2023 * 2024 * Convert the values in the security context structure @oldc from the values 2025 * specified in the policy @args->oldp to the values specified in the policy 2026 * @args->newp, storing the new context in @newc, and verifying that the 2027 * context is valid under the new policy. 2028 */ 2029 int services_convert_context(struct convert_context_args *args, 2030 struct context *oldc, struct context *newc, 2031 gfp_t gfp_flags) 2032 { 2033 struct ocontext *oc; 2034 struct role_datum *role; 2035 struct type_datum *typdatum; 2036 struct user_datum *usrdatum; 2037 char *s; 2038 u32 len; 2039 int rc; 2040 2041 if (oldc->str) { 2042 s = kstrdup(oldc->str, gfp_flags); 2043 if (!s) 2044 return -ENOMEM; 2045 2046 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL); 2047 if (rc == -EINVAL) { 2048 /* 2049 * Retain string representation for later mapping. 2050 * 2051 * IMPORTANT: We need to copy the contents of oldc->str 2052 * back into s again because string_to_context_struct() 2053 * may have garbled it. 2054 */ 2055 memcpy(s, oldc->str, oldc->len); 2056 context_init(newc); 2057 newc->str = s; 2058 newc->len = oldc->len; 2059 return 0; 2060 } 2061 kfree(s); 2062 if (rc) { 2063 /* Other error condition, e.g. ENOMEM. */ 2064 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2065 oldc->str, -rc); 2066 return rc; 2067 } 2068 pr_info("SELinux: Context %s became valid (mapped).\n", 2069 oldc->str); 2070 return 0; 2071 } 2072 2073 context_init(newc); 2074 2075 /* Convert the user. */ 2076 usrdatum = symtab_search(&args->newp->p_users, 2077 sym_name(args->oldp, SYM_USERS, oldc->user - 1)); 2078 if (!usrdatum) 2079 goto bad; 2080 newc->user = usrdatum->value; 2081 2082 /* Convert the role. */ 2083 role = symtab_search(&args->newp->p_roles, 2084 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2085 if (!role) 2086 goto bad; 2087 newc->role = role->value; 2088 2089 /* Convert the type. */ 2090 typdatum = symtab_search(&args->newp->p_types, 2091 sym_name(args->oldp, SYM_TYPES, oldc->type - 1)); 2092 if (!typdatum) 2093 goto bad; 2094 newc->type = typdatum->value; 2095 2096 /* Convert the MLS fields if dealing with MLS policies */ 2097 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2098 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2099 if (rc) 2100 goto bad; 2101 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2102 /* 2103 * Switching between non-MLS and MLS policy: 2104 * ensure that the MLS fields of the context for all 2105 * existing entries in the sidtab are filled in with a 2106 * suitable default value, likely taken from one of the 2107 * initial SIDs. 2108 */ 2109 oc = args->newp->ocontexts[OCON_ISID]; 2110 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2111 oc = oc->next; 2112 if (!oc) { 2113 pr_err("SELinux: unable to look up" 2114 " the initial SIDs list\n"); 2115 goto bad; 2116 } 2117 rc = mls_range_set(newc, &oc->context[0].range); 2118 if (rc) 2119 goto bad; 2120 } 2121 2122 /* Check the validity of the new context. */ 2123 if (!policydb_context_isvalid(args->newp, newc)) { 2124 rc = convert_context_handle_invalid_context(args->oldp, oldc); 2125 if (rc) 2126 goto bad; 2127 } 2128 2129 return 0; 2130 bad: 2131 /* Map old representation to string and save it. */ 2132 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2133 if (rc) 2134 return rc; 2135 context_destroy(newc); 2136 newc->str = s; 2137 newc->len = len; 2138 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2139 newc->str); 2140 return 0; 2141 } 2142 2143 static void security_load_policycaps(struct selinux_policy *policy) 2144 { 2145 struct policydb *p; 2146 unsigned int i; 2147 struct ebitmap_node *node; 2148 2149 p = &policy->policydb; 2150 2151 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++) 2152 WRITE_ONCE(selinux_state.policycap[i], 2153 ebitmap_get_bit(&p->policycaps, i)); 2154 2155 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2156 pr_info("SELinux: policy capability %s=%d\n", 2157 selinux_policycap_names[i], 2158 ebitmap_get_bit(&p->policycaps, i)); 2159 2160 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2161 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2162 pr_info("SELinux: unknown policy capability %u\n", 2163 i); 2164 } 2165 } 2166 2167 static int security_preserve_bools(struct selinux_policy *oldpolicy, 2168 struct selinux_policy *newpolicy); 2169 2170 static void selinux_policy_free(struct selinux_policy *policy) 2171 { 2172 if (!policy) 2173 return; 2174 2175 sidtab_destroy(policy->sidtab); 2176 kfree(policy->map.mapping); 2177 policydb_destroy(&policy->policydb); 2178 kfree(policy->sidtab); 2179 kfree(policy); 2180 } 2181 2182 static void selinux_policy_cond_free(struct selinux_policy *policy) 2183 { 2184 cond_policydb_destroy_dup(&policy->policydb); 2185 kfree(policy); 2186 } 2187 2188 void selinux_policy_cancel(struct selinux_load_state *load_state) 2189 { 2190 struct selinux_state *state = &selinux_state; 2191 struct selinux_policy *oldpolicy; 2192 2193 oldpolicy = rcu_dereference_protected(state->policy, 2194 lockdep_is_held(&state->policy_mutex)); 2195 2196 sidtab_cancel_convert(oldpolicy->sidtab); 2197 selinux_policy_free(load_state->policy); 2198 kfree(load_state->convert_data); 2199 } 2200 2201 static void selinux_notify_policy_change(u32 seqno) 2202 { 2203 /* Flush external caches and notify userspace of policy load */ 2204 avc_ss_reset(seqno); 2205 selnl_notify_policyload(seqno); 2206 selinux_status_update_policyload(seqno); 2207 selinux_netlbl_cache_invalidate(); 2208 selinux_xfrm_notify_policyload(); 2209 selinux_ima_measure_state_locked(); 2210 } 2211 2212 void selinux_policy_commit(struct selinux_load_state *load_state) 2213 { 2214 struct selinux_state *state = &selinux_state; 2215 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2216 unsigned long flags; 2217 u32 seqno; 2218 2219 oldpolicy = rcu_dereference_protected(state->policy, 2220 lockdep_is_held(&state->policy_mutex)); 2221 2222 /* If switching between different policy types, log MLS status */ 2223 if (oldpolicy) { 2224 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2225 pr_info("SELinux: Disabling MLS support...\n"); 2226 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2227 pr_info("SELinux: Enabling MLS support...\n"); 2228 } 2229 2230 /* Set latest granting seqno for new policy. */ 2231 if (oldpolicy) 2232 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2233 else 2234 newpolicy->latest_granting = 1; 2235 seqno = newpolicy->latest_granting; 2236 2237 /* Install the new policy. */ 2238 if (oldpolicy) { 2239 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2240 rcu_assign_pointer(state->policy, newpolicy); 2241 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2242 } else { 2243 rcu_assign_pointer(state->policy, newpolicy); 2244 } 2245 2246 /* Load the policycaps from the new policy */ 2247 security_load_policycaps(newpolicy); 2248 2249 if (!selinux_initialized()) { 2250 /* 2251 * After first policy load, the security server is 2252 * marked as initialized and ready to handle requests and 2253 * any objects created prior to policy load are then labeled. 2254 */ 2255 selinux_mark_initialized(); 2256 selinux_complete_init(); 2257 } 2258 2259 /* Free the old policy */ 2260 synchronize_rcu(); 2261 selinux_policy_free(oldpolicy); 2262 kfree(load_state->convert_data); 2263 2264 /* Notify others of the policy change */ 2265 selinux_notify_policy_change(seqno); 2266 } 2267 2268 /** 2269 * security_load_policy - Load a security policy configuration. 2270 * @data: binary policy data 2271 * @len: length of data in bytes 2272 * @load_state: policy load state 2273 * 2274 * Load a new set of security policy configuration data, 2275 * validate it and convert the SID table as necessary. 2276 * This function will flush the access vector cache after 2277 * loading the new policy. 2278 */ 2279 int security_load_policy(void *data, size_t len, 2280 struct selinux_load_state *load_state) 2281 { 2282 struct selinux_state *state = &selinux_state; 2283 struct selinux_policy *newpolicy, *oldpolicy; 2284 struct selinux_policy_convert_data *convert_data; 2285 int rc = 0; 2286 struct policy_file file = { data, len }, *fp = &file; 2287 2288 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); 2289 if (!newpolicy) 2290 return -ENOMEM; 2291 2292 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); 2293 if (!newpolicy->sidtab) { 2294 rc = -ENOMEM; 2295 goto err_policy; 2296 } 2297 2298 rc = policydb_read(&newpolicy->policydb, fp); 2299 if (rc) 2300 goto err_sidtab; 2301 2302 newpolicy->policydb.len = len; 2303 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, 2304 &newpolicy->map); 2305 if (rc) 2306 goto err_policydb; 2307 2308 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); 2309 if (rc) { 2310 pr_err("SELinux: unable to load the initial SIDs\n"); 2311 goto err_mapping; 2312 } 2313 2314 if (!selinux_initialized()) { 2315 /* First policy load, so no need to preserve state from old policy */ 2316 load_state->policy = newpolicy; 2317 load_state->convert_data = NULL; 2318 return 0; 2319 } 2320 2321 oldpolicy = rcu_dereference_protected(state->policy, 2322 lockdep_is_held(&state->policy_mutex)); 2323 2324 /* Preserve active boolean values from the old policy */ 2325 rc = security_preserve_bools(oldpolicy, newpolicy); 2326 if (rc) { 2327 pr_err("SELinux: unable to preserve booleans\n"); 2328 goto err_free_isids; 2329 } 2330 2331 /* 2332 * Convert the internal representations of contexts 2333 * in the new SID table. 2334 */ 2335 2336 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2337 if (!convert_data) { 2338 rc = -ENOMEM; 2339 goto err_free_isids; 2340 } 2341 2342 convert_data->args.oldp = &oldpolicy->policydb; 2343 convert_data->args.newp = &newpolicy->policydb; 2344 2345 convert_data->sidtab_params.args = &convert_data->args; 2346 convert_data->sidtab_params.target = newpolicy->sidtab; 2347 2348 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); 2349 if (rc) { 2350 pr_err("SELinux: unable to convert the internal" 2351 " representation of contexts in the new SID" 2352 " table\n"); 2353 goto err_free_convert_data; 2354 } 2355 2356 load_state->policy = newpolicy; 2357 load_state->convert_data = convert_data; 2358 return 0; 2359 2360 err_free_convert_data: 2361 kfree(convert_data); 2362 err_free_isids: 2363 sidtab_destroy(newpolicy->sidtab); 2364 err_mapping: 2365 kfree(newpolicy->map.mapping); 2366 err_policydb: 2367 policydb_destroy(&newpolicy->policydb); 2368 err_sidtab: 2369 kfree(newpolicy->sidtab); 2370 err_policy: 2371 kfree(newpolicy); 2372 2373 return rc; 2374 } 2375 2376 /** 2377 * ocontext_to_sid - Helper to safely get sid for an ocontext 2378 * @sidtab: SID table 2379 * @c: ocontext structure 2380 * @index: index of the context entry (0 or 1) 2381 * @out_sid: pointer to the resulting SID value 2382 * 2383 * For all ocontexts except OCON_ISID the SID fields are populated 2384 * on-demand when needed. Since updating the SID value is an SMP-sensitive 2385 * operation, this helper must be used to do that safely. 2386 * 2387 * WARNING: This function may return -ESTALE, indicating that the caller 2388 * must retry the operation after re-acquiring the policy pointer! 2389 */ 2390 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, 2391 size_t index, u32 *out_sid) 2392 { 2393 int rc; 2394 u32 sid; 2395 2396 /* Ensure the associated sidtab entry is visible to this thread. */ 2397 sid = smp_load_acquire(&c->sid[index]); 2398 if (!sid) { 2399 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); 2400 if (rc) 2401 return rc; 2402 2403 /* 2404 * Ensure the new sidtab entry is visible to other threads 2405 * when they see the SID. 2406 */ 2407 smp_store_release(&c->sid[index], sid); 2408 } 2409 *out_sid = sid; 2410 return 0; 2411 } 2412 2413 /** 2414 * security_port_sid - Obtain the SID for a port. 2415 * @protocol: protocol number 2416 * @port: port number 2417 * @out_sid: security identifier 2418 */ 2419 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2420 { 2421 struct selinux_policy *policy; 2422 struct policydb *policydb; 2423 struct sidtab *sidtab; 2424 struct ocontext *c; 2425 int rc; 2426 2427 if (!selinux_initialized()) { 2428 *out_sid = SECINITSID_PORT; 2429 return 0; 2430 } 2431 2432 retry: 2433 rc = 0; 2434 rcu_read_lock(); 2435 policy = rcu_dereference(selinux_state.policy); 2436 policydb = &policy->policydb; 2437 sidtab = policy->sidtab; 2438 2439 c = policydb->ocontexts[OCON_PORT]; 2440 while (c) { 2441 if (c->u.port.protocol == protocol && 2442 c->u.port.low_port <= port && 2443 c->u.port.high_port >= port) 2444 break; 2445 c = c->next; 2446 } 2447 2448 if (c) { 2449 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2450 if (rc == -ESTALE) { 2451 rcu_read_unlock(); 2452 goto retry; 2453 } 2454 if (rc) 2455 goto out; 2456 } else { 2457 *out_sid = SECINITSID_PORT; 2458 } 2459 2460 out: 2461 rcu_read_unlock(); 2462 return rc; 2463 } 2464 2465 /** 2466 * security_ib_pkey_sid - Obtain the SID for a pkey. 2467 * @subnet_prefix: Subnet Prefix 2468 * @pkey_num: pkey number 2469 * @out_sid: security identifier 2470 */ 2471 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2472 { 2473 struct selinux_policy *policy; 2474 struct policydb *policydb; 2475 struct sidtab *sidtab; 2476 struct ocontext *c; 2477 int rc; 2478 2479 if (!selinux_initialized()) { 2480 *out_sid = SECINITSID_UNLABELED; 2481 return 0; 2482 } 2483 2484 retry: 2485 rc = 0; 2486 rcu_read_lock(); 2487 policy = rcu_dereference(selinux_state.policy); 2488 policydb = &policy->policydb; 2489 sidtab = policy->sidtab; 2490 2491 c = policydb->ocontexts[OCON_IBPKEY]; 2492 while (c) { 2493 if (c->u.ibpkey.low_pkey <= pkey_num && 2494 c->u.ibpkey.high_pkey >= pkey_num && 2495 c->u.ibpkey.subnet_prefix == subnet_prefix) 2496 break; 2497 2498 c = c->next; 2499 } 2500 2501 if (c) { 2502 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2503 if (rc == -ESTALE) { 2504 rcu_read_unlock(); 2505 goto retry; 2506 } 2507 if (rc) 2508 goto out; 2509 } else 2510 *out_sid = SECINITSID_UNLABELED; 2511 2512 out: 2513 rcu_read_unlock(); 2514 return rc; 2515 } 2516 2517 /** 2518 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2519 * @dev_name: device name 2520 * @port_num: port number 2521 * @out_sid: security identifier 2522 */ 2523 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) 2524 { 2525 struct selinux_policy *policy; 2526 struct policydb *policydb; 2527 struct sidtab *sidtab; 2528 struct ocontext *c; 2529 int rc; 2530 2531 if (!selinux_initialized()) { 2532 *out_sid = SECINITSID_UNLABELED; 2533 return 0; 2534 } 2535 2536 retry: 2537 rc = 0; 2538 rcu_read_lock(); 2539 policy = rcu_dereference(selinux_state.policy); 2540 policydb = &policy->policydb; 2541 sidtab = policy->sidtab; 2542 2543 c = policydb->ocontexts[OCON_IBENDPORT]; 2544 while (c) { 2545 if (c->u.ibendport.port == port_num && 2546 !strncmp(c->u.ibendport.dev_name, 2547 dev_name, 2548 IB_DEVICE_NAME_MAX)) 2549 break; 2550 2551 c = c->next; 2552 } 2553 2554 if (c) { 2555 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2556 if (rc == -ESTALE) { 2557 rcu_read_unlock(); 2558 goto retry; 2559 } 2560 if (rc) 2561 goto out; 2562 } else 2563 *out_sid = SECINITSID_UNLABELED; 2564 2565 out: 2566 rcu_read_unlock(); 2567 return rc; 2568 } 2569 2570 /** 2571 * security_netif_sid - Obtain the SID for a network interface. 2572 * @name: interface name 2573 * @if_sid: interface SID 2574 */ 2575 int security_netif_sid(char *name, u32 *if_sid) 2576 { 2577 struct selinux_policy *policy; 2578 struct policydb *policydb; 2579 struct sidtab *sidtab; 2580 int rc; 2581 struct ocontext *c; 2582 2583 if (!selinux_initialized()) { 2584 *if_sid = SECINITSID_NETIF; 2585 return 0; 2586 } 2587 2588 retry: 2589 rc = 0; 2590 rcu_read_lock(); 2591 policy = rcu_dereference(selinux_state.policy); 2592 policydb = &policy->policydb; 2593 sidtab = policy->sidtab; 2594 2595 c = policydb->ocontexts[OCON_NETIF]; 2596 while (c) { 2597 if (strcmp(name, c->u.name) == 0) 2598 break; 2599 c = c->next; 2600 } 2601 2602 if (c) { 2603 rc = ocontext_to_sid(sidtab, c, 0, if_sid); 2604 if (rc == -ESTALE) { 2605 rcu_read_unlock(); 2606 goto retry; 2607 } 2608 if (rc) 2609 goto out; 2610 } else 2611 *if_sid = SECINITSID_NETIF; 2612 2613 out: 2614 rcu_read_unlock(); 2615 return rc; 2616 } 2617 2618 static bool match_ipv6_addrmask(const u32 input[4], const u32 addr[4], const u32 mask[4]) 2619 { 2620 int i; 2621 2622 for (i = 0; i < 4; i++) 2623 if (addr[i] != (input[i] & mask[i])) 2624 return false; 2625 2626 return true; 2627 } 2628 2629 /** 2630 * security_node_sid - Obtain the SID for a node (host). 2631 * @domain: communication domain aka address family 2632 * @addrp: address 2633 * @addrlen: address length in bytes 2634 * @out_sid: security identifier 2635 */ 2636 int security_node_sid(u16 domain, 2637 void *addrp, 2638 u32 addrlen, 2639 u32 *out_sid) 2640 { 2641 struct selinux_policy *policy; 2642 struct policydb *policydb; 2643 struct sidtab *sidtab; 2644 int rc; 2645 struct ocontext *c; 2646 2647 if (!selinux_initialized()) { 2648 *out_sid = SECINITSID_NODE; 2649 return 0; 2650 } 2651 2652 retry: 2653 rcu_read_lock(); 2654 policy = rcu_dereference(selinux_state.policy); 2655 policydb = &policy->policydb; 2656 sidtab = policy->sidtab; 2657 2658 switch (domain) { 2659 case AF_INET: { 2660 u32 addr; 2661 2662 rc = -EINVAL; 2663 if (addrlen != sizeof(u32)) 2664 goto out; 2665 2666 addr = *((u32 *)addrp); 2667 2668 c = policydb->ocontexts[OCON_NODE]; 2669 while (c) { 2670 if (c->u.node.addr == (addr & c->u.node.mask)) 2671 break; 2672 c = c->next; 2673 } 2674 break; 2675 } 2676 2677 case AF_INET6: 2678 rc = -EINVAL; 2679 if (addrlen != sizeof(u64) * 2) 2680 goto out; 2681 c = policydb->ocontexts[OCON_NODE6]; 2682 while (c) { 2683 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2684 c->u.node6.mask)) 2685 break; 2686 c = c->next; 2687 } 2688 break; 2689 2690 default: 2691 rc = 0; 2692 *out_sid = SECINITSID_NODE; 2693 goto out; 2694 } 2695 2696 if (c) { 2697 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2698 if (rc == -ESTALE) { 2699 rcu_read_unlock(); 2700 goto retry; 2701 } 2702 if (rc) 2703 goto out; 2704 } else { 2705 *out_sid = SECINITSID_NODE; 2706 } 2707 2708 rc = 0; 2709 out: 2710 rcu_read_unlock(); 2711 return rc; 2712 } 2713 2714 #define SIDS_NEL 25 2715 2716 /** 2717 * security_get_user_sids - Obtain reachable SIDs for a user. 2718 * @fromsid: starting SID 2719 * @username: username 2720 * @sids: array of reachable SIDs for user 2721 * @nel: number of elements in @sids 2722 * 2723 * Generate the set of SIDs for legal security contexts 2724 * for a given user that can be reached by @fromsid. 2725 * Set *@sids to point to a dynamically allocated 2726 * array containing the set of SIDs. Set *@nel to the 2727 * number of elements in the array. 2728 */ 2729 2730 int security_get_user_sids(u32 fromsid, 2731 const char *username, 2732 u32 **sids, 2733 u32 *nel) 2734 { 2735 struct selinux_policy *policy; 2736 struct policydb *policydb; 2737 struct sidtab *sidtab; 2738 struct context *fromcon, usercon; 2739 u32 *mysids = NULL, *mysids2, sid; 2740 u32 i, j, mynel, maxnel = SIDS_NEL; 2741 struct user_datum *user; 2742 struct role_datum *role; 2743 struct ebitmap_node *rnode, *tnode; 2744 int rc; 2745 2746 *sids = NULL; 2747 *nel = 0; 2748 2749 if (!selinux_initialized()) 2750 return 0; 2751 2752 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2753 if (!mysids) 2754 return -ENOMEM; 2755 2756 retry: 2757 mynel = 0; 2758 rcu_read_lock(); 2759 policy = rcu_dereference(selinux_state.policy); 2760 policydb = &policy->policydb; 2761 sidtab = policy->sidtab; 2762 2763 context_init(&usercon); 2764 2765 rc = -EINVAL; 2766 fromcon = sidtab_search(sidtab, fromsid); 2767 if (!fromcon) 2768 goto out_unlock; 2769 2770 rc = -EINVAL; 2771 user = symtab_search(&policydb->p_users, username); 2772 if (!user) 2773 goto out_unlock; 2774 2775 usercon.user = user->value; 2776 2777 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2778 role = policydb->role_val_to_struct[i]; 2779 usercon.role = i + 1; 2780 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2781 usercon.type = j + 1; 2782 2783 if (mls_setup_user_range(policydb, fromcon, user, 2784 &usercon)) 2785 continue; 2786 2787 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2788 if (rc == -ESTALE) { 2789 rcu_read_unlock(); 2790 goto retry; 2791 } 2792 if (rc) 2793 goto out_unlock; 2794 if (mynel < maxnel) { 2795 mysids[mynel++] = sid; 2796 } else { 2797 rc = -ENOMEM; 2798 maxnel += SIDS_NEL; 2799 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2800 if (!mysids2) 2801 goto out_unlock; 2802 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2803 kfree(mysids); 2804 mysids = mysids2; 2805 mysids[mynel++] = sid; 2806 } 2807 } 2808 } 2809 rc = 0; 2810 out_unlock: 2811 rcu_read_unlock(); 2812 if (rc || !mynel) { 2813 kfree(mysids); 2814 return rc; 2815 } 2816 2817 rc = -ENOMEM; 2818 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2819 if (!mysids2) { 2820 kfree(mysids); 2821 return rc; 2822 } 2823 for (i = 0, j = 0; i < mynel; i++) { 2824 struct av_decision dummy_avd; 2825 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2826 SECCLASS_PROCESS, /* kernel value */ 2827 PROCESS__TRANSITION, AVC_STRICT, 2828 &dummy_avd); 2829 if (!rc) 2830 mysids2[j++] = mysids[i]; 2831 cond_resched(); 2832 } 2833 kfree(mysids); 2834 *sids = mysids2; 2835 *nel = j; 2836 return 0; 2837 } 2838 2839 /** 2840 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2841 * @policy: policy 2842 * @fstype: filesystem type 2843 * @path: path from root of mount 2844 * @orig_sclass: file security class 2845 * @sid: SID for path 2846 * 2847 * Obtain a SID to use for a file in a filesystem that 2848 * cannot support xattr or use a fixed labeling behavior like 2849 * transition SIDs or task SIDs. 2850 * 2851 * WARNING: This function may return -ESTALE, indicating that the caller 2852 * must retry the operation after re-acquiring the policy pointer! 2853 */ 2854 static inline int __security_genfs_sid(struct selinux_policy *policy, 2855 const char *fstype, 2856 const char *path, 2857 u16 orig_sclass, 2858 u32 *sid) 2859 { 2860 struct policydb *policydb = &policy->policydb; 2861 struct sidtab *sidtab = policy->sidtab; 2862 u16 sclass; 2863 struct genfs *genfs; 2864 struct ocontext *c; 2865 int cmp = 0; 2866 2867 while (path[0] == '/' && path[1] == '/') 2868 path++; 2869 2870 sclass = unmap_class(&policy->map, orig_sclass); 2871 *sid = SECINITSID_UNLABELED; 2872 2873 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2874 cmp = strcmp(fstype, genfs->fstype); 2875 if (cmp <= 0) 2876 break; 2877 } 2878 2879 if (!genfs || cmp) 2880 return -ENOENT; 2881 2882 for (c = genfs->head; c; c = c->next) { 2883 size_t len = strlen(c->u.name); 2884 if ((!c->v.sclass || sclass == c->v.sclass) && 2885 (strncmp(c->u.name, path, len) == 0)) 2886 break; 2887 } 2888 2889 if (!c) 2890 return -ENOENT; 2891 2892 return ocontext_to_sid(sidtab, c, 0, sid); 2893 } 2894 2895 /** 2896 * security_genfs_sid - Obtain a SID for a file in a filesystem 2897 * @fstype: filesystem type 2898 * @path: path from root of mount 2899 * @orig_sclass: file security class 2900 * @sid: SID for path 2901 * 2902 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2903 * it afterward. 2904 */ 2905 int security_genfs_sid(const char *fstype, 2906 const char *path, 2907 u16 orig_sclass, 2908 u32 *sid) 2909 { 2910 struct selinux_policy *policy; 2911 int retval; 2912 2913 if (!selinux_initialized()) { 2914 *sid = SECINITSID_UNLABELED; 2915 return 0; 2916 } 2917 2918 do { 2919 rcu_read_lock(); 2920 policy = rcu_dereference(selinux_state.policy); 2921 retval = __security_genfs_sid(policy, fstype, path, 2922 orig_sclass, sid); 2923 rcu_read_unlock(); 2924 } while (retval == -ESTALE); 2925 return retval; 2926 } 2927 2928 int selinux_policy_genfs_sid(struct selinux_policy *policy, 2929 const char *fstype, 2930 const char *path, 2931 u16 orig_sclass, 2932 u32 *sid) 2933 { 2934 /* no lock required, policy is not yet accessible by other threads */ 2935 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2936 } 2937 2938 /** 2939 * security_fs_use - Determine how to handle labeling for a filesystem. 2940 * @sb: superblock in question 2941 */ 2942 int security_fs_use(struct super_block *sb) 2943 { 2944 struct selinux_policy *policy; 2945 struct policydb *policydb; 2946 struct sidtab *sidtab; 2947 int rc; 2948 struct ocontext *c; 2949 struct superblock_security_struct *sbsec = selinux_superblock(sb); 2950 const char *fstype = sb->s_type->name; 2951 2952 if (!selinux_initialized()) { 2953 sbsec->behavior = SECURITY_FS_USE_NONE; 2954 sbsec->sid = SECINITSID_UNLABELED; 2955 return 0; 2956 } 2957 2958 retry: 2959 rcu_read_lock(); 2960 policy = rcu_dereference(selinux_state.policy); 2961 policydb = &policy->policydb; 2962 sidtab = policy->sidtab; 2963 2964 c = policydb->ocontexts[OCON_FSUSE]; 2965 while (c) { 2966 if (strcmp(fstype, c->u.name) == 0) 2967 break; 2968 c = c->next; 2969 } 2970 2971 if (c) { 2972 sbsec->behavior = c->v.behavior; 2973 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); 2974 if (rc == -ESTALE) { 2975 rcu_read_unlock(); 2976 goto retry; 2977 } 2978 if (rc) 2979 goto out; 2980 } else { 2981 rc = __security_genfs_sid(policy, fstype, "/", 2982 SECCLASS_DIR, &sbsec->sid); 2983 if (rc == -ESTALE) { 2984 rcu_read_unlock(); 2985 goto retry; 2986 } 2987 if (rc) { 2988 sbsec->behavior = SECURITY_FS_USE_NONE; 2989 rc = 0; 2990 } else { 2991 sbsec->behavior = SECURITY_FS_USE_GENFS; 2992 } 2993 } 2994 2995 out: 2996 rcu_read_unlock(); 2997 return rc; 2998 } 2999 3000 int security_get_bools(struct selinux_policy *policy, 3001 u32 *len, char ***names, int **values) 3002 { 3003 struct policydb *policydb; 3004 u32 i; 3005 int rc; 3006 3007 policydb = &policy->policydb; 3008 3009 *names = NULL; 3010 *values = NULL; 3011 3012 rc = 0; 3013 *len = policydb->p_bools.nprim; 3014 if (!*len) 3015 goto out; 3016 3017 rc = -ENOMEM; 3018 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 3019 if (!*names) 3020 goto err; 3021 3022 rc = -ENOMEM; 3023 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 3024 if (!*values) 3025 goto err; 3026 3027 for (i = 0; i < *len; i++) { 3028 (*values)[i] = policydb->bool_val_to_struct[i]->state; 3029 3030 rc = -ENOMEM; 3031 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 3032 GFP_ATOMIC); 3033 if (!(*names)[i]) 3034 goto err; 3035 } 3036 rc = 0; 3037 out: 3038 return rc; 3039 err: 3040 if (*names) { 3041 for (i = 0; i < *len; i++) 3042 kfree((*names)[i]); 3043 kfree(*names); 3044 } 3045 kfree(*values); 3046 *len = 0; 3047 *names = NULL; 3048 *values = NULL; 3049 goto out; 3050 } 3051 3052 3053 int security_set_bools(u32 len, const int *values) 3054 { 3055 struct selinux_state *state = &selinux_state; 3056 struct selinux_policy *newpolicy, *oldpolicy; 3057 int rc; 3058 u32 i, seqno = 0; 3059 3060 if (!selinux_initialized()) 3061 return -EINVAL; 3062 3063 oldpolicy = rcu_dereference_protected(state->policy, 3064 lockdep_is_held(&state->policy_mutex)); 3065 3066 /* Consistency check on number of booleans, should never fail */ 3067 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) 3068 return -EINVAL; 3069 3070 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); 3071 if (!newpolicy) 3072 return -ENOMEM; 3073 3074 /* 3075 * Deep copy only the parts of the policydb that might be 3076 * modified as a result of changing booleans. 3077 */ 3078 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); 3079 if (rc) { 3080 kfree(newpolicy); 3081 return -ENOMEM; 3082 } 3083 3084 /* Update the boolean states in the copy */ 3085 for (i = 0; i < len; i++) { 3086 int new_state = !!values[i]; 3087 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; 3088 3089 if (new_state != old_state) { 3090 audit_log(audit_context(), GFP_ATOMIC, 3091 AUDIT_MAC_CONFIG_CHANGE, 3092 "bool=%s val=%d old_val=%d auid=%u ses=%u", 3093 sym_name(&newpolicy->policydb, SYM_BOOLS, i), 3094 new_state, 3095 old_state, 3096 from_kuid(&init_user_ns, audit_get_loginuid(current)), 3097 audit_get_sessionid(current)); 3098 newpolicy->policydb.bool_val_to_struct[i]->state = new_state; 3099 } 3100 } 3101 3102 /* Re-evaluate the conditional rules in the copy */ 3103 evaluate_cond_nodes(&newpolicy->policydb); 3104 3105 /* Set latest granting seqno for new policy */ 3106 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 3107 seqno = newpolicy->latest_granting; 3108 3109 /* Install the new policy */ 3110 rcu_assign_pointer(state->policy, newpolicy); 3111 3112 /* 3113 * Free the conditional portions of the old policydb 3114 * that were copied for the new policy, and the oldpolicy 3115 * structure itself but not what it references. 3116 */ 3117 synchronize_rcu(); 3118 selinux_policy_cond_free(oldpolicy); 3119 3120 /* Notify others of the policy change */ 3121 selinux_notify_policy_change(seqno); 3122 return 0; 3123 } 3124 3125 int security_get_bool_value(u32 index) 3126 { 3127 struct selinux_policy *policy; 3128 struct policydb *policydb; 3129 int rc; 3130 u32 len; 3131 3132 if (!selinux_initialized()) 3133 return 0; 3134 3135 rcu_read_lock(); 3136 policy = rcu_dereference(selinux_state.policy); 3137 policydb = &policy->policydb; 3138 3139 rc = -EFAULT; 3140 len = policydb->p_bools.nprim; 3141 if (index >= len) 3142 goto out; 3143 3144 rc = policydb->bool_val_to_struct[index]->state; 3145 out: 3146 rcu_read_unlock(); 3147 return rc; 3148 } 3149 3150 static int security_preserve_bools(struct selinux_policy *oldpolicy, 3151 struct selinux_policy *newpolicy) 3152 { 3153 int rc, *bvalues = NULL; 3154 char **bnames = NULL; 3155 struct cond_bool_datum *booldatum; 3156 u32 i, nbools = 0; 3157 3158 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); 3159 if (rc) 3160 goto out; 3161 for (i = 0; i < nbools; i++) { 3162 booldatum = symtab_search(&newpolicy->policydb.p_bools, 3163 bnames[i]); 3164 if (booldatum) 3165 booldatum->state = bvalues[i]; 3166 } 3167 evaluate_cond_nodes(&newpolicy->policydb); 3168 3169 out: 3170 if (bnames) { 3171 for (i = 0; i < nbools; i++) 3172 kfree(bnames[i]); 3173 } 3174 kfree(bnames); 3175 kfree(bvalues); 3176 return rc; 3177 } 3178 3179 /* 3180 * security_sid_mls_copy() - computes a new sid based on the given 3181 * sid and the mls portion of mls_sid. 3182 */ 3183 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 3184 { 3185 struct selinux_policy *policy; 3186 struct policydb *policydb; 3187 struct sidtab *sidtab; 3188 struct context *context1; 3189 struct context *context2; 3190 struct context newcon; 3191 char *s; 3192 u32 len; 3193 int rc; 3194 3195 if (!selinux_initialized()) { 3196 *new_sid = sid; 3197 return 0; 3198 } 3199 3200 retry: 3201 rc = 0; 3202 context_init(&newcon); 3203 3204 rcu_read_lock(); 3205 policy = rcu_dereference(selinux_state.policy); 3206 policydb = &policy->policydb; 3207 sidtab = policy->sidtab; 3208 3209 if (!policydb->mls_enabled) { 3210 *new_sid = sid; 3211 goto out_unlock; 3212 } 3213 3214 rc = -EINVAL; 3215 context1 = sidtab_search(sidtab, sid); 3216 if (!context1) { 3217 pr_err("SELinux: %s: unrecognized SID %d\n", 3218 __func__, sid); 3219 goto out_unlock; 3220 } 3221 3222 rc = -EINVAL; 3223 context2 = sidtab_search(sidtab, mls_sid); 3224 if (!context2) { 3225 pr_err("SELinux: %s: unrecognized SID %d\n", 3226 __func__, mls_sid); 3227 goto out_unlock; 3228 } 3229 3230 newcon.user = context1->user; 3231 newcon.role = context1->role; 3232 newcon.type = context1->type; 3233 rc = mls_context_cpy(&newcon, context2); 3234 if (rc) 3235 goto out_unlock; 3236 3237 /* Check the validity of the new context. */ 3238 if (!policydb_context_isvalid(policydb, &newcon)) { 3239 rc = convert_context_handle_invalid_context(policydb, 3240 &newcon); 3241 if (rc) { 3242 if (!context_struct_to_string(policydb, &newcon, &s, 3243 &len)) { 3244 struct audit_buffer *ab; 3245 3246 ab = audit_log_start(audit_context(), 3247 GFP_ATOMIC, 3248 AUDIT_SELINUX_ERR); 3249 audit_log_format(ab, 3250 "op=security_sid_mls_copy invalid_context="); 3251 /* don't record NUL with untrusted strings */ 3252 audit_log_n_untrustedstring(ab, s, len - 1); 3253 audit_log_end(ab); 3254 kfree(s); 3255 } 3256 goto out_unlock; 3257 } 3258 } 3259 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3260 if (rc == -ESTALE) { 3261 rcu_read_unlock(); 3262 context_destroy(&newcon); 3263 goto retry; 3264 } 3265 out_unlock: 3266 rcu_read_unlock(); 3267 context_destroy(&newcon); 3268 return rc; 3269 } 3270 3271 /** 3272 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3273 * @nlbl_sid: NetLabel SID 3274 * @nlbl_type: NetLabel labeling protocol type 3275 * @xfrm_sid: XFRM SID 3276 * @peer_sid: network peer sid 3277 * 3278 * Description: 3279 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3280 * resolved into a single SID it is returned via @peer_sid and the function 3281 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3282 * returns a negative value. A table summarizing the behavior is below: 3283 * 3284 * | function return | @sid 3285 * ------------------------------+-----------------+----------------- 3286 * no peer labels | 0 | SECSID_NULL 3287 * single peer label | 0 | <peer_label> 3288 * multiple, consistent labels | 0 | <peer_label> 3289 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3290 * 3291 */ 3292 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 3293 u32 xfrm_sid, 3294 u32 *peer_sid) 3295 { 3296 struct selinux_policy *policy; 3297 struct policydb *policydb; 3298 struct sidtab *sidtab; 3299 int rc; 3300 struct context *nlbl_ctx; 3301 struct context *xfrm_ctx; 3302 3303 *peer_sid = SECSID_NULL; 3304 3305 /* handle the common (which also happens to be the set of easy) cases 3306 * right away, these two if statements catch everything involving a 3307 * single or absent peer SID/label */ 3308 if (xfrm_sid == SECSID_NULL) { 3309 *peer_sid = nlbl_sid; 3310 return 0; 3311 } 3312 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3313 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3314 * is present */ 3315 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3316 *peer_sid = xfrm_sid; 3317 return 0; 3318 } 3319 3320 if (!selinux_initialized()) 3321 return 0; 3322 3323 rcu_read_lock(); 3324 policy = rcu_dereference(selinux_state.policy); 3325 policydb = &policy->policydb; 3326 sidtab = policy->sidtab; 3327 3328 /* 3329 * We don't need to check initialized here since the only way both 3330 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3331 * security server was initialized and state->initialized was true. 3332 */ 3333 if (!policydb->mls_enabled) { 3334 rc = 0; 3335 goto out; 3336 } 3337 3338 rc = -EINVAL; 3339 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3340 if (!nlbl_ctx) { 3341 pr_err("SELinux: %s: unrecognized SID %d\n", 3342 __func__, nlbl_sid); 3343 goto out; 3344 } 3345 rc = -EINVAL; 3346 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3347 if (!xfrm_ctx) { 3348 pr_err("SELinux: %s: unrecognized SID %d\n", 3349 __func__, xfrm_sid); 3350 goto out; 3351 } 3352 rc = (mls_context_equal(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3353 if (rc) 3354 goto out; 3355 3356 /* at present NetLabel SIDs/labels really only carry MLS 3357 * information so if the MLS portion of the NetLabel SID 3358 * matches the MLS portion of the labeled XFRM SID/label 3359 * then pass along the XFRM SID as it is the most 3360 * expressive */ 3361 *peer_sid = xfrm_sid; 3362 out: 3363 rcu_read_unlock(); 3364 return rc; 3365 } 3366 3367 static int get_classes_callback(void *k, void *d, void *args) 3368 { 3369 struct class_datum *datum = d; 3370 char *name = k, **classes = args; 3371 u32 value = datum->value - 1; 3372 3373 classes[value] = kstrdup(name, GFP_ATOMIC); 3374 if (!classes[value]) 3375 return -ENOMEM; 3376 3377 return 0; 3378 } 3379 3380 int security_get_classes(struct selinux_policy *policy, 3381 char ***classes, u32 *nclasses) 3382 { 3383 struct policydb *policydb; 3384 int rc; 3385 3386 policydb = &policy->policydb; 3387 3388 rc = -ENOMEM; 3389 *nclasses = policydb->p_classes.nprim; 3390 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3391 if (!*classes) 3392 goto out; 3393 3394 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3395 *classes); 3396 if (rc) { 3397 u32 i; 3398 3399 for (i = 0; i < *nclasses; i++) 3400 kfree((*classes)[i]); 3401 kfree(*classes); 3402 } 3403 3404 out: 3405 return rc; 3406 } 3407 3408 static int get_permissions_callback(void *k, void *d, void *args) 3409 { 3410 struct perm_datum *datum = d; 3411 char *name = k, **perms = args; 3412 u32 value = datum->value - 1; 3413 3414 perms[value] = kstrdup(name, GFP_ATOMIC); 3415 if (!perms[value]) 3416 return -ENOMEM; 3417 3418 return 0; 3419 } 3420 3421 int security_get_permissions(struct selinux_policy *policy, 3422 const char *class, char ***perms, u32 *nperms) 3423 { 3424 struct policydb *policydb; 3425 u32 i; 3426 int rc; 3427 struct class_datum *match; 3428 3429 policydb = &policy->policydb; 3430 3431 rc = -EINVAL; 3432 match = symtab_search(&policydb->p_classes, class); 3433 if (!match) { 3434 pr_err("SELinux: %s: unrecognized class %s\n", 3435 __func__, class); 3436 goto out; 3437 } 3438 3439 rc = -ENOMEM; 3440 *nperms = match->permissions.nprim; 3441 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3442 if (!*perms) 3443 goto out; 3444 3445 if (match->comdatum) { 3446 rc = hashtab_map(&match->comdatum->permissions.table, 3447 get_permissions_callback, *perms); 3448 if (rc) 3449 goto err; 3450 } 3451 3452 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3453 *perms); 3454 if (rc) 3455 goto err; 3456 3457 out: 3458 return rc; 3459 3460 err: 3461 for (i = 0; i < *nperms; i++) 3462 kfree((*perms)[i]); 3463 kfree(*perms); 3464 return rc; 3465 } 3466 3467 int security_get_reject_unknown(void) 3468 { 3469 struct selinux_policy *policy; 3470 int value; 3471 3472 if (!selinux_initialized()) 3473 return 0; 3474 3475 rcu_read_lock(); 3476 policy = rcu_dereference(selinux_state.policy); 3477 value = policy->policydb.reject_unknown; 3478 rcu_read_unlock(); 3479 return value; 3480 } 3481 3482 int security_get_allow_unknown(void) 3483 { 3484 struct selinux_policy *policy; 3485 int value; 3486 3487 if (!selinux_initialized()) 3488 return 0; 3489 3490 rcu_read_lock(); 3491 policy = rcu_dereference(selinux_state.policy); 3492 value = policy->policydb.allow_unknown; 3493 rcu_read_unlock(); 3494 return value; 3495 } 3496 3497 /** 3498 * security_policycap_supported - Check for a specific policy capability 3499 * @req_cap: capability 3500 * 3501 * Description: 3502 * This function queries the currently loaded policy to see if it supports the 3503 * capability specified by @req_cap. Returns true (1) if the capability is 3504 * supported, false (0) if it isn't supported. 3505 * 3506 */ 3507 int security_policycap_supported(unsigned int req_cap) 3508 { 3509 struct selinux_policy *policy; 3510 int rc; 3511 3512 if (!selinux_initialized()) 3513 return 0; 3514 3515 rcu_read_lock(); 3516 policy = rcu_dereference(selinux_state.policy); 3517 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3518 rcu_read_unlock(); 3519 3520 return rc; 3521 } 3522 3523 struct selinux_audit_rule { 3524 u32 au_seqno; 3525 struct context au_ctxt; 3526 }; 3527 3528 void selinux_audit_rule_free(void *vrule) 3529 { 3530 struct selinux_audit_rule *rule = vrule; 3531 3532 if (rule) { 3533 context_destroy(&rule->au_ctxt); 3534 kfree(rule); 3535 } 3536 } 3537 3538 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule, 3539 gfp_t gfp) 3540 { 3541 struct selinux_state *state = &selinux_state; 3542 struct selinux_policy *policy; 3543 struct policydb *policydb; 3544 struct selinux_audit_rule *tmprule; 3545 struct role_datum *roledatum; 3546 struct type_datum *typedatum; 3547 struct user_datum *userdatum; 3548 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3549 int rc = 0; 3550 3551 *rule = NULL; 3552 3553 if (!selinux_initialized()) 3554 return -EOPNOTSUPP; 3555 3556 switch (field) { 3557 case AUDIT_SUBJ_USER: 3558 case AUDIT_SUBJ_ROLE: 3559 case AUDIT_SUBJ_TYPE: 3560 case AUDIT_OBJ_USER: 3561 case AUDIT_OBJ_ROLE: 3562 case AUDIT_OBJ_TYPE: 3563 /* only 'equals' and 'not equals' fit user, role, and type */ 3564 if (op != Audit_equal && op != Audit_not_equal) 3565 return -EINVAL; 3566 break; 3567 case AUDIT_SUBJ_SEN: 3568 case AUDIT_SUBJ_CLR: 3569 case AUDIT_OBJ_LEV_LOW: 3570 case AUDIT_OBJ_LEV_HIGH: 3571 /* we do not allow a range, indicated by the presence of '-' */ 3572 if (strchr(rulestr, '-')) 3573 return -EINVAL; 3574 break; 3575 default: 3576 /* only the above fields are valid */ 3577 return -EINVAL; 3578 } 3579 3580 tmprule = kzalloc(sizeof(struct selinux_audit_rule), gfp); 3581 if (!tmprule) 3582 return -ENOMEM; 3583 context_init(&tmprule->au_ctxt); 3584 3585 rcu_read_lock(); 3586 policy = rcu_dereference(state->policy); 3587 policydb = &policy->policydb; 3588 tmprule->au_seqno = policy->latest_granting; 3589 switch (field) { 3590 case AUDIT_SUBJ_USER: 3591 case AUDIT_OBJ_USER: 3592 userdatum = symtab_search(&policydb->p_users, rulestr); 3593 if (!userdatum) { 3594 rc = -EINVAL; 3595 goto err; 3596 } 3597 tmprule->au_ctxt.user = userdatum->value; 3598 break; 3599 case AUDIT_SUBJ_ROLE: 3600 case AUDIT_OBJ_ROLE: 3601 roledatum = symtab_search(&policydb->p_roles, rulestr); 3602 if (!roledatum) { 3603 rc = -EINVAL; 3604 goto err; 3605 } 3606 tmprule->au_ctxt.role = roledatum->value; 3607 break; 3608 case AUDIT_SUBJ_TYPE: 3609 case AUDIT_OBJ_TYPE: 3610 typedatum = symtab_search(&policydb->p_types, rulestr); 3611 if (!typedatum) { 3612 rc = -EINVAL; 3613 goto err; 3614 } 3615 tmprule->au_ctxt.type = typedatum->value; 3616 break; 3617 case AUDIT_SUBJ_SEN: 3618 case AUDIT_SUBJ_CLR: 3619 case AUDIT_OBJ_LEV_LOW: 3620 case AUDIT_OBJ_LEV_HIGH: 3621 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3622 GFP_ATOMIC); 3623 if (rc) 3624 goto err; 3625 break; 3626 } 3627 rcu_read_unlock(); 3628 3629 *rule = tmprule; 3630 return 0; 3631 3632 err: 3633 rcu_read_unlock(); 3634 selinux_audit_rule_free(tmprule); 3635 *rule = NULL; 3636 return rc; 3637 } 3638 3639 /* Check to see if the rule contains any selinux fields */ 3640 int selinux_audit_rule_known(struct audit_krule *rule) 3641 { 3642 u32 i; 3643 3644 for (i = 0; i < rule->field_count; i++) { 3645 struct audit_field *f = &rule->fields[i]; 3646 switch (f->type) { 3647 case AUDIT_SUBJ_USER: 3648 case AUDIT_SUBJ_ROLE: 3649 case AUDIT_SUBJ_TYPE: 3650 case AUDIT_SUBJ_SEN: 3651 case AUDIT_SUBJ_CLR: 3652 case AUDIT_OBJ_USER: 3653 case AUDIT_OBJ_ROLE: 3654 case AUDIT_OBJ_TYPE: 3655 case AUDIT_OBJ_LEV_LOW: 3656 case AUDIT_OBJ_LEV_HIGH: 3657 return 1; 3658 } 3659 } 3660 3661 return 0; 3662 } 3663 3664 int selinux_audit_rule_match(struct lsm_prop *prop, u32 field, u32 op, void *vrule) 3665 { 3666 struct selinux_state *state = &selinux_state; 3667 struct selinux_policy *policy; 3668 struct context *ctxt; 3669 struct mls_level *level; 3670 struct selinux_audit_rule *rule = vrule; 3671 int match = 0; 3672 3673 if (unlikely(!rule)) { 3674 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3675 return -ENOENT; 3676 } 3677 3678 if (!selinux_initialized()) 3679 return 0; 3680 3681 rcu_read_lock(); 3682 3683 policy = rcu_dereference(state->policy); 3684 3685 if (rule->au_seqno < policy->latest_granting) { 3686 match = -ESTALE; 3687 goto out; 3688 } 3689 3690 ctxt = sidtab_search(policy->sidtab, prop->selinux.secid); 3691 if (unlikely(!ctxt)) { 3692 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3693 prop->selinux.secid); 3694 match = -ENOENT; 3695 goto out; 3696 } 3697 3698 /* a field/op pair that is not caught here will simply fall through 3699 without a match */ 3700 switch (field) { 3701 case AUDIT_SUBJ_USER: 3702 case AUDIT_OBJ_USER: 3703 switch (op) { 3704 case Audit_equal: 3705 match = (ctxt->user == rule->au_ctxt.user); 3706 break; 3707 case Audit_not_equal: 3708 match = (ctxt->user != rule->au_ctxt.user); 3709 break; 3710 } 3711 break; 3712 case AUDIT_SUBJ_ROLE: 3713 case AUDIT_OBJ_ROLE: 3714 switch (op) { 3715 case Audit_equal: 3716 match = (ctxt->role == rule->au_ctxt.role); 3717 break; 3718 case Audit_not_equal: 3719 match = (ctxt->role != rule->au_ctxt.role); 3720 break; 3721 } 3722 break; 3723 case AUDIT_SUBJ_TYPE: 3724 case AUDIT_OBJ_TYPE: 3725 switch (op) { 3726 case Audit_equal: 3727 match = (ctxt->type == rule->au_ctxt.type); 3728 break; 3729 case Audit_not_equal: 3730 match = (ctxt->type != rule->au_ctxt.type); 3731 break; 3732 } 3733 break; 3734 case AUDIT_SUBJ_SEN: 3735 case AUDIT_SUBJ_CLR: 3736 case AUDIT_OBJ_LEV_LOW: 3737 case AUDIT_OBJ_LEV_HIGH: 3738 level = ((field == AUDIT_SUBJ_SEN || 3739 field == AUDIT_OBJ_LEV_LOW) ? 3740 &ctxt->range.level[0] : &ctxt->range.level[1]); 3741 switch (op) { 3742 case Audit_equal: 3743 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3744 level); 3745 break; 3746 case Audit_not_equal: 3747 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3748 level); 3749 break; 3750 case Audit_lt: 3751 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3752 level) && 3753 !mls_level_eq(&rule->au_ctxt.range.level[0], 3754 level)); 3755 break; 3756 case Audit_le: 3757 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3758 level); 3759 break; 3760 case Audit_gt: 3761 match = (mls_level_dom(level, 3762 &rule->au_ctxt.range.level[0]) && 3763 !mls_level_eq(level, 3764 &rule->au_ctxt.range.level[0])); 3765 break; 3766 case Audit_ge: 3767 match = mls_level_dom(level, 3768 &rule->au_ctxt.range.level[0]); 3769 break; 3770 } 3771 } 3772 3773 out: 3774 rcu_read_unlock(); 3775 return match; 3776 } 3777 3778 static int aurule_avc_callback(u32 event) 3779 { 3780 if (event == AVC_CALLBACK_RESET) 3781 return audit_update_lsm_rules(); 3782 return 0; 3783 } 3784 3785 static int __init aurule_init(void) 3786 { 3787 int err; 3788 3789 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3790 if (err) 3791 panic("avc_add_callback() failed, error %d\n", err); 3792 3793 return err; 3794 } 3795 __initcall(aurule_init); 3796 3797 #ifdef CONFIG_NETLABEL 3798 /** 3799 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3800 * @secattr: the NetLabel packet security attributes 3801 * @sid: the SELinux SID 3802 * 3803 * Description: 3804 * Attempt to cache the context in @ctx, which was derived from the packet in 3805 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3806 * already been initialized. 3807 * 3808 */ 3809 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3810 u32 sid) 3811 { 3812 u32 *sid_cache; 3813 3814 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3815 if (sid_cache == NULL) 3816 return; 3817 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3818 if (secattr->cache == NULL) { 3819 kfree(sid_cache); 3820 return; 3821 } 3822 3823 *sid_cache = sid; 3824 secattr->cache->free = kfree; 3825 secattr->cache->data = sid_cache; 3826 secattr->flags |= NETLBL_SECATTR_CACHE; 3827 } 3828 3829 /** 3830 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3831 * @secattr: the NetLabel packet security attributes 3832 * @sid: the SELinux SID 3833 * 3834 * Description: 3835 * Convert the given NetLabel security attributes in @secattr into a 3836 * SELinux SID. If the @secattr field does not contain a full SELinux 3837 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3838 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3839 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3840 * conversion for future lookups. Returns zero on success, negative values on 3841 * failure. 3842 * 3843 */ 3844 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3845 u32 *sid) 3846 { 3847 struct selinux_policy *policy; 3848 struct policydb *policydb; 3849 struct sidtab *sidtab; 3850 int rc; 3851 struct context *ctx; 3852 struct context ctx_new; 3853 3854 if (!selinux_initialized()) { 3855 *sid = SECSID_NULL; 3856 return 0; 3857 } 3858 3859 retry: 3860 rc = 0; 3861 rcu_read_lock(); 3862 policy = rcu_dereference(selinux_state.policy); 3863 policydb = &policy->policydb; 3864 sidtab = policy->sidtab; 3865 3866 if (secattr->flags & NETLBL_SECATTR_CACHE) 3867 *sid = *(u32 *)secattr->cache->data; 3868 else if (secattr->flags & NETLBL_SECATTR_SECID) 3869 *sid = secattr->attr.secid; 3870 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3871 rc = -EIDRM; 3872 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3873 if (ctx == NULL) 3874 goto out; 3875 3876 context_init(&ctx_new); 3877 ctx_new.user = ctx->user; 3878 ctx_new.role = ctx->role; 3879 ctx_new.type = ctx->type; 3880 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3881 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3882 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3883 if (rc) 3884 goto out; 3885 } 3886 rc = -EIDRM; 3887 if (!mls_context_isvalid(policydb, &ctx_new)) { 3888 ebitmap_destroy(&ctx_new.range.level[0].cat); 3889 goto out; 3890 } 3891 3892 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3893 ebitmap_destroy(&ctx_new.range.level[0].cat); 3894 if (rc == -ESTALE) { 3895 rcu_read_unlock(); 3896 goto retry; 3897 } 3898 if (rc) 3899 goto out; 3900 3901 security_netlbl_cache_add(secattr, *sid); 3902 } else 3903 *sid = SECSID_NULL; 3904 3905 out: 3906 rcu_read_unlock(); 3907 return rc; 3908 } 3909 3910 /** 3911 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3912 * @sid: the SELinux SID 3913 * @secattr: the NetLabel packet security attributes 3914 * 3915 * Description: 3916 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3917 * Returns zero on success, negative values on failure. 3918 * 3919 */ 3920 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3921 { 3922 struct selinux_policy *policy; 3923 struct policydb *policydb; 3924 int rc; 3925 struct context *ctx; 3926 3927 if (!selinux_initialized()) 3928 return 0; 3929 3930 rcu_read_lock(); 3931 policy = rcu_dereference(selinux_state.policy); 3932 policydb = &policy->policydb; 3933 3934 rc = -ENOENT; 3935 ctx = sidtab_search(policy->sidtab, sid); 3936 if (ctx == NULL) 3937 goto out; 3938 3939 rc = -ENOMEM; 3940 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3941 GFP_ATOMIC); 3942 if (secattr->domain == NULL) 3943 goto out; 3944 3945 secattr->attr.secid = sid; 3946 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3947 mls_export_netlbl_lvl(policydb, ctx, secattr); 3948 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3949 out: 3950 rcu_read_unlock(); 3951 return rc; 3952 } 3953 #endif /* CONFIG_NETLABEL */ 3954 3955 /** 3956 * __security_read_policy - read the policy. 3957 * @policy: SELinux policy 3958 * @data: binary policy data 3959 * @len: length of data in bytes 3960 * 3961 */ 3962 static int __security_read_policy(struct selinux_policy *policy, 3963 void *data, size_t *len) 3964 { 3965 int rc; 3966 struct policy_file fp; 3967 3968 fp.data = data; 3969 fp.len = *len; 3970 3971 rc = policydb_write(&policy->policydb, &fp); 3972 if (rc) 3973 return rc; 3974 3975 *len = (unsigned long)fp.data - (unsigned long)data; 3976 return 0; 3977 } 3978 3979 /** 3980 * security_read_policy - read the policy. 3981 * @data: binary policy data 3982 * @len: length of data in bytes 3983 * 3984 */ 3985 int security_read_policy(void **data, size_t *len) 3986 { 3987 struct selinux_state *state = &selinux_state; 3988 struct selinux_policy *policy; 3989 3990 policy = rcu_dereference_protected( 3991 state->policy, lockdep_is_held(&state->policy_mutex)); 3992 if (!policy) 3993 return -EINVAL; 3994 3995 *len = policy->policydb.len; 3996 *data = vmalloc_user(*len); 3997 if (!*data) 3998 return -ENOMEM; 3999 4000 return __security_read_policy(policy, *data, len); 4001 } 4002 4003 /** 4004 * security_read_state_kernel - read the policy. 4005 * @data: binary policy data 4006 * @len: length of data in bytes 4007 * 4008 * Allocates kernel memory for reading SELinux policy. 4009 * This function is for internal use only and should not 4010 * be used for returning data to user space. 4011 * 4012 * This function must be called with policy_mutex held. 4013 */ 4014 int security_read_state_kernel(void **data, size_t *len) 4015 { 4016 int err; 4017 struct selinux_state *state = &selinux_state; 4018 struct selinux_policy *policy; 4019 4020 policy = rcu_dereference_protected( 4021 state->policy, lockdep_is_held(&state->policy_mutex)); 4022 if (!policy) 4023 return -EINVAL; 4024 4025 *len = policy->policydb.len; 4026 *data = vmalloc(*len); 4027 if (!*data) 4028 return -ENOMEM; 4029 4030 err = __security_read_policy(policy, *data, len); 4031 if (err) { 4032 vfree(*data); 4033 *data = NULL; 4034 *len = 0; 4035 } 4036 return err; 4037 } 4038