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