1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Implementation of the security services. 4 * 5 * Authors : Stephen Smalley, <sds@tycho.nsa.gov> 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 unsigned k; 101 bool print_unknown_handle = false; 102 103 /* Find number of classes in the input mapping */ 104 if (!map) 105 return -EINVAL; 106 i = 0; 107 while (map[i].name) 108 i++; 109 110 /* Allocate space for the class records, plus one for class zero */ 111 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 112 if (!out_map->mapping) 113 return -ENOMEM; 114 115 /* Store the raw class and permission values */ 116 j = 0; 117 while (map[j].name) { 118 const struct security_class_mapping *p_in = map + (j++); 119 struct selinux_mapping *p_out = out_map->mapping + j; 120 121 /* 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 |= 1<<i; 211 if (allow_unknown && !mapping->perms[i]) 212 result |= 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 |= 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 |= 1<<i; 224 if (!allow_unknown && !mapping->perms[i]) 225 result |= 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 |= 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 int 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 = initial_sid_to_string[sid]; 1326 1327 if (!s) 1328 return -EINVAL; 1329 *scontext_len = strlen(s) + 1; 1330 if (!scontext) 1331 return 0; 1332 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1333 if (!scontextp) 1334 return -ENOMEM; 1335 *scontext = scontextp; 1336 return 0; 1337 } 1338 pr_err("SELinux: %s: called before initial " 1339 "load_policy on unknown SID %d\n", __func__, sid); 1340 return -EINVAL; 1341 } 1342 rcu_read_lock(); 1343 policy = rcu_dereference(selinux_state.policy); 1344 policydb = &policy->policydb; 1345 sidtab = policy->sidtab; 1346 1347 if (force) 1348 entry = sidtab_search_entry_force(sidtab, sid); 1349 else 1350 entry = sidtab_search_entry(sidtab, sid); 1351 if (!entry) { 1352 pr_err("SELinux: %s: unrecognized SID %d\n", 1353 __func__, sid); 1354 rc = -EINVAL; 1355 goto out_unlock; 1356 } 1357 if (only_invalid && !entry->context.len) 1358 goto out_unlock; 1359 1360 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1361 scontext_len); 1362 1363 out_unlock: 1364 rcu_read_unlock(); 1365 return rc; 1366 1367 } 1368 1369 /** 1370 * security_sid_to_context - Obtain a context for a given SID. 1371 * @sid: security identifier, SID 1372 * @scontext: security context 1373 * @scontext_len: length in bytes 1374 * 1375 * Write the string representation of the context associated with @sid 1376 * into a dynamically allocated string of the correct size. Set @scontext 1377 * to point to this string and set @scontext_len to the length of the string. 1378 */ 1379 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1380 { 1381 return security_sid_to_context_core(sid, scontext, 1382 scontext_len, 0, 0); 1383 } 1384 1385 int security_sid_to_context_force(u32 sid, 1386 char **scontext, u32 *scontext_len) 1387 { 1388 return security_sid_to_context_core(sid, scontext, 1389 scontext_len, 1, 0); 1390 } 1391 1392 /** 1393 * security_sid_to_context_inval - Obtain a context for a given SID if it 1394 * is invalid. 1395 * @sid: security identifier, SID 1396 * @scontext: security context 1397 * @scontext_len: length in bytes 1398 * 1399 * Write the string representation of the context associated with @sid 1400 * into a dynamically allocated string of the correct size, but only if the 1401 * context is invalid in the current policy. Set @scontext to point to 1402 * this string (or NULL if the context is valid) and set @scontext_len to 1403 * the length of the string (or 0 if the context is valid). 1404 */ 1405 int security_sid_to_context_inval(u32 sid, 1406 char **scontext, u32 *scontext_len) 1407 { 1408 return security_sid_to_context_core(sid, scontext, 1409 scontext_len, 1, 1); 1410 } 1411 1412 /* 1413 * Caveat: Mutates scontext. 1414 */ 1415 static int string_to_context_struct(struct policydb *pol, 1416 struct sidtab *sidtabp, 1417 char *scontext, 1418 struct context *ctx, 1419 u32 def_sid) 1420 { 1421 struct role_datum *role; 1422 struct type_datum *typdatum; 1423 struct user_datum *usrdatum; 1424 char *scontextp, *p, oldc; 1425 int rc = 0; 1426 1427 context_init(ctx); 1428 1429 /* Parse the security context. */ 1430 1431 rc = -EINVAL; 1432 scontextp = scontext; 1433 1434 /* Extract the user. */ 1435 p = scontextp; 1436 while (*p && *p != ':') 1437 p++; 1438 1439 if (*p == 0) 1440 goto out; 1441 1442 *p++ = 0; 1443 1444 usrdatum = symtab_search(&pol->p_users, scontextp); 1445 if (!usrdatum) 1446 goto out; 1447 1448 ctx->user = usrdatum->value; 1449 1450 /* Extract role. */ 1451 scontextp = p; 1452 while (*p && *p != ':') 1453 p++; 1454 1455 if (*p == 0) 1456 goto out; 1457 1458 *p++ = 0; 1459 1460 role = symtab_search(&pol->p_roles, scontextp); 1461 if (!role) 1462 goto out; 1463 ctx->role = role->value; 1464 1465 /* Extract type. */ 1466 scontextp = p; 1467 while (*p && *p != ':') 1468 p++; 1469 oldc = *p; 1470 *p++ = 0; 1471 1472 typdatum = symtab_search(&pol->p_types, scontextp); 1473 if (!typdatum || typdatum->attribute) 1474 goto out; 1475 1476 ctx->type = typdatum->value; 1477 1478 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1479 if (rc) 1480 goto out; 1481 1482 /* Check the validity of the new context. */ 1483 rc = -EINVAL; 1484 if (!policydb_context_isvalid(pol, ctx)) 1485 goto out; 1486 rc = 0; 1487 out: 1488 if (rc) 1489 context_destroy(ctx); 1490 return rc; 1491 } 1492 1493 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1494 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1495 int force) 1496 { 1497 struct selinux_policy *policy; 1498 struct policydb *policydb; 1499 struct sidtab *sidtab; 1500 char *scontext2, *str = NULL; 1501 struct context context; 1502 int rc = 0; 1503 1504 /* An empty security context is never valid. */ 1505 if (!scontext_len) 1506 return -EINVAL; 1507 1508 /* Copy the string to allow changes and ensure a NUL terminator */ 1509 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1510 if (!scontext2) 1511 return -ENOMEM; 1512 1513 if (!selinux_initialized()) { 1514 int i; 1515 1516 for (i = 1; i < SECINITSID_NUM; i++) { 1517 const char *s = initial_sid_to_string[i]; 1518 1519 if (s && !strcmp(s, scontext2)) { 1520 *sid = i; 1521 goto out; 1522 } 1523 } 1524 *sid = SECINITSID_KERNEL; 1525 goto out; 1526 } 1527 *sid = SECSID_NULL; 1528 1529 if (force) { 1530 /* Save another copy for storing in uninterpreted form */ 1531 rc = -ENOMEM; 1532 str = kstrdup(scontext2, gfp_flags); 1533 if (!str) 1534 goto out; 1535 } 1536 retry: 1537 rcu_read_lock(); 1538 policy = rcu_dereference(selinux_state.policy); 1539 policydb = &policy->policydb; 1540 sidtab = policy->sidtab; 1541 rc = string_to_context_struct(policydb, sidtab, scontext2, 1542 &context, def_sid); 1543 if (rc == -EINVAL && force) { 1544 context.str = str; 1545 context.len = strlen(str) + 1; 1546 str = NULL; 1547 } else if (rc) 1548 goto out_unlock; 1549 rc = sidtab_context_to_sid(sidtab, &context, sid); 1550 if (rc == -ESTALE) { 1551 rcu_read_unlock(); 1552 if (context.str) { 1553 str = context.str; 1554 context.str = NULL; 1555 } 1556 context_destroy(&context); 1557 goto retry; 1558 } 1559 context_destroy(&context); 1560 out_unlock: 1561 rcu_read_unlock(); 1562 out: 1563 kfree(scontext2); 1564 kfree(str); 1565 return rc; 1566 } 1567 1568 /** 1569 * security_context_to_sid - Obtain a SID for a given security context. 1570 * @scontext: security context 1571 * @scontext_len: length in bytes 1572 * @sid: security identifier, SID 1573 * @gfp: context for the allocation 1574 * 1575 * Obtains a SID associated with the security context that 1576 * has the string representation specified by @scontext. 1577 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1578 * memory is available, or 0 on success. 1579 */ 1580 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1581 gfp_t gfp) 1582 { 1583 return security_context_to_sid_core(scontext, scontext_len, 1584 sid, SECSID_NULL, gfp, 0); 1585 } 1586 1587 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1588 { 1589 return security_context_to_sid(scontext, strlen(scontext), 1590 sid, gfp); 1591 } 1592 1593 /** 1594 * security_context_to_sid_default - Obtain a SID for a given security context, 1595 * falling back to specified default if needed. 1596 * 1597 * @scontext: security context 1598 * @scontext_len: length in bytes 1599 * @sid: security identifier, SID 1600 * @def_sid: default SID to assign on error 1601 * @gfp_flags: the allocator get-free-page (GFP) flags 1602 * 1603 * Obtains a SID associated with the security context that 1604 * has the string representation specified by @scontext. 1605 * The default SID is passed to the MLS layer to be used to allow 1606 * kernel labeling of the MLS field if the MLS field is not present 1607 * (for upgrading to MLS without full relabel). 1608 * Implicitly forces adding of the context even if it cannot be mapped yet. 1609 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1610 * memory is available, or 0 on success. 1611 */ 1612 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1613 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1614 { 1615 return security_context_to_sid_core(scontext, scontext_len, 1616 sid, def_sid, gfp_flags, 1); 1617 } 1618 1619 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1620 u32 *sid) 1621 { 1622 return security_context_to_sid_core(scontext, scontext_len, 1623 sid, SECSID_NULL, GFP_KERNEL, 1); 1624 } 1625 1626 static int compute_sid_handle_invalid_context( 1627 struct selinux_policy *policy, 1628 struct sidtab_entry *sentry, 1629 struct sidtab_entry *tentry, 1630 u16 tclass, 1631 struct context *newcontext) 1632 { 1633 struct policydb *policydb = &policy->policydb; 1634 struct sidtab *sidtab = policy->sidtab; 1635 char *s = NULL, *t = NULL, *n = NULL; 1636 u32 slen, tlen, nlen; 1637 struct audit_buffer *ab; 1638 1639 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) 1640 goto out; 1641 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) 1642 goto out; 1643 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1644 goto out; 1645 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); 1646 if (!ab) 1647 goto out; 1648 audit_log_format(ab, 1649 "op=security_compute_sid invalid_context="); 1650 /* no need to record the NUL with untrusted strings */ 1651 audit_log_n_untrustedstring(ab, n, nlen - 1); 1652 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1653 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1654 audit_log_end(ab); 1655 out: 1656 kfree(s); 1657 kfree(t); 1658 kfree(n); 1659 if (!enforcing_enabled()) 1660 return 0; 1661 return -EACCES; 1662 } 1663 1664 static void filename_compute_type(struct policydb *policydb, 1665 struct context *newcontext, 1666 u32 stype, u32 ttype, u16 tclass, 1667 const char *objname) 1668 { 1669 struct filename_trans_key ft; 1670 struct filename_trans_datum *datum; 1671 1672 /* 1673 * Most filename trans rules are going to live in specific directories 1674 * like /dev or /var/run. This bitmap will quickly skip rule searches 1675 * if the ttype does not contain any rules. 1676 */ 1677 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1678 return; 1679 1680 ft.ttype = ttype; 1681 ft.tclass = tclass; 1682 ft.name = objname; 1683 1684 datum = policydb_filenametr_search(policydb, &ft); 1685 while (datum) { 1686 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1687 newcontext->type = datum->otype; 1688 return; 1689 } 1690 datum = datum->next; 1691 } 1692 } 1693 1694 static int security_compute_sid(u32 ssid, 1695 u32 tsid, 1696 u16 orig_tclass, 1697 u32 specified, 1698 const char *objname, 1699 u32 *out_sid, 1700 bool kern) 1701 { 1702 struct selinux_policy *policy; 1703 struct policydb *policydb; 1704 struct sidtab *sidtab; 1705 struct class_datum *cladatum; 1706 struct context *scontext, *tcontext, newcontext; 1707 struct sidtab_entry *sentry, *tentry; 1708 struct avtab_key avkey; 1709 struct avtab_datum *avdatum; 1710 struct avtab_node *node; 1711 u16 tclass; 1712 int rc = 0; 1713 bool sock; 1714 1715 if (!selinux_initialized()) { 1716 switch (orig_tclass) { 1717 case SECCLASS_PROCESS: /* kernel value */ 1718 *out_sid = ssid; 1719 break; 1720 default: 1721 *out_sid = tsid; 1722 break; 1723 } 1724 goto out; 1725 } 1726 1727 retry: 1728 cladatum = NULL; 1729 context_init(&newcontext); 1730 1731 rcu_read_lock(); 1732 1733 policy = rcu_dereference(selinux_state.policy); 1734 1735 if (kern) { 1736 tclass = unmap_class(&policy->map, orig_tclass); 1737 sock = security_is_socket_class(orig_tclass); 1738 } else { 1739 tclass = orig_tclass; 1740 sock = security_is_socket_class(map_class(&policy->map, 1741 tclass)); 1742 } 1743 1744 policydb = &policy->policydb; 1745 sidtab = policy->sidtab; 1746 1747 sentry = sidtab_search_entry(sidtab, ssid); 1748 if (!sentry) { 1749 pr_err("SELinux: %s: unrecognized SID %d\n", 1750 __func__, ssid); 1751 rc = -EINVAL; 1752 goto out_unlock; 1753 } 1754 tentry = sidtab_search_entry(sidtab, tsid); 1755 if (!tentry) { 1756 pr_err("SELinux: %s: unrecognized SID %d\n", 1757 __func__, tsid); 1758 rc = -EINVAL; 1759 goto out_unlock; 1760 } 1761 1762 scontext = &sentry->context; 1763 tcontext = &tentry->context; 1764 1765 if (tclass && tclass <= policydb->p_classes.nprim) 1766 cladatum = policydb->class_val_to_struct[tclass - 1]; 1767 1768 /* Set the user identity. */ 1769 switch (specified) { 1770 case AVTAB_TRANSITION: 1771 case AVTAB_CHANGE: 1772 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1773 newcontext.user = tcontext->user; 1774 } else { 1775 /* notice this gets both DEFAULT_SOURCE and unset */ 1776 /* Use the process user identity. */ 1777 newcontext.user = scontext->user; 1778 } 1779 break; 1780 case AVTAB_MEMBER: 1781 /* Use the related object owner. */ 1782 newcontext.user = tcontext->user; 1783 break; 1784 } 1785 1786 /* Set the role to default values. */ 1787 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1788 newcontext.role = scontext->role; 1789 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1790 newcontext.role = tcontext->role; 1791 } else { 1792 if ((tclass == policydb->process_class) || sock) 1793 newcontext.role = scontext->role; 1794 else 1795 newcontext.role = OBJECT_R_VAL; 1796 } 1797 1798 /* Set the type to default values. */ 1799 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1800 newcontext.type = scontext->type; 1801 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1802 newcontext.type = tcontext->type; 1803 } else { 1804 if ((tclass == policydb->process_class) || sock) { 1805 /* Use the type of process. */ 1806 newcontext.type = scontext->type; 1807 } else { 1808 /* Use the type of the related object. */ 1809 newcontext.type = tcontext->type; 1810 } 1811 } 1812 1813 /* Look for a type transition/member/change rule. */ 1814 avkey.source_type = scontext->type; 1815 avkey.target_type = tcontext->type; 1816 avkey.target_class = tclass; 1817 avkey.specified = specified; 1818 avdatum = avtab_search(&policydb->te_avtab, &avkey); 1819 1820 /* If no permanent rule, also check for enabled conditional rules */ 1821 if (!avdatum) { 1822 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1823 for (; node; node = avtab_search_node_next(node, specified)) { 1824 if (node->key.specified & AVTAB_ENABLED) { 1825 avdatum = &node->datum; 1826 break; 1827 } 1828 } 1829 } 1830 1831 if (avdatum) { 1832 /* Use the type from the type transition/member/change rule. */ 1833 newcontext.type = avdatum->u.data; 1834 } 1835 1836 /* if we have a objname this is a file trans check so check those rules */ 1837 if (objname) 1838 filename_compute_type(policydb, &newcontext, scontext->type, 1839 tcontext->type, tclass, objname); 1840 1841 /* Check for class-specific changes. */ 1842 if (specified & AVTAB_TRANSITION) { 1843 /* Look for a role transition rule. */ 1844 struct role_trans_datum *rtd; 1845 struct role_trans_key rtk = { 1846 .role = scontext->role, 1847 .type = tcontext->type, 1848 .tclass = tclass, 1849 }; 1850 1851 rtd = policydb_roletr_search(policydb, &rtk); 1852 if (rtd) 1853 newcontext.role = rtd->new_role; 1854 } 1855 1856 /* Set the MLS attributes. 1857 This is done last because it may allocate memory. */ 1858 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1859 &newcontext, sock); 1860 if (rc) 1861 goto out_unlock; 1862 1863 /* Check the validity of the context. */ 1864 if (!policydb_context_isvalid(policydb, &newcontext)) { 1865 rc = compute_sid_handle_invalid_context(policy, sentry, 1866 tentry, tclass, 1867 &newcontext); 1868 if (rc) 1869 goto out_unlock; 1870 } 1871 /* Obtain the sid for the context. */ 1872 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1873 if (rc == -ESTALE) { 1874 rcu_read_unlock(); 1875 context_destroy(&newcontext); 1876 goto retry; 1877 } 1878 out_unlock: 1879 rcu_read_unlock(); 1880 context_destroy(&newcontext); 1881 out: 1882 return rc; 1883 } 1884 1885 /** 1886 * security_transition_sid - Compute the SID for a new subject/object. 1887 * @ssid: source security identifier 1888 * @tsid: target security identifier 1889 * @tclass: target security class 1890 * @qstr: object name 1891 * @out_sid: security identifier for new subject/object 1892 * 1893 * Compute a SID to use for labeling a new subject or object in the 1894 * class @tclass based on a SID pair (@ssid, @tsid). 1895 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1896 * if insufficient memory is available, or %0 if the new SID was 1897 * computed successfully. 1898 */ 1899 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1900 const struct qstr *qstr, u32 *out_sid) 1901 { 1902 return security_compute_sid(ssid, tsid, tclass, 1903 AVTAB_TRANSITION, 1904 qstr ? qstr->name : NULL, out_sid, true); 1905 } 1906 1907 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1908 const char *objname, u32 *out_sid) 1909 { 1910 return security_compute_sid(ssid, tsid, tclass, 1911 AVTAB_TRANSITION, 1912 objname, out_sid, false); 1913 } 1914 1915 /** 1916 * security_member_sid - Compute the SID for member selection. 1917 * @ssid: source security identifier 1918 * @tsid: target security identifier 1919 * @tclass: target security class 1920 * @out_sid: security identifier for selected member 1921 * 1922 * Compute a SID to use when selecting a member of a polyinstantiated 1923 * object of class @tclass based on a SID pair (@ssid, @tsid). 1924 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1925 * if insufficient memory is available, or %0 if the SID was 1926 * computed successfully. 1927 */ 1928 int security_member_sid(u32 ssid, 1929 u32 tsid, 1930 u16 tclass, 1931 u32 *out_sid) 1932 { 1933 return security_compute_sid(ssid, tsid, tclass, 1934 AVTAB_MEMBER, NULL, 1935 out_sid, false); 1936 } 1937 1938 /** 1939 * security_change_sid - Compute the SID for object relabeling. 1940 * @ssid: source security identifier 1941 * @tsid: target security identifier 1942 * @tclass: target security class 1943 * @out_sid: security identifier for selected member 1944 * 1945 * Compute a SID to use for relabeling an object of class @tclass 1946 * based on a SID pair (@ssid, @tsid). 1947 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1948 * if insufficient memory is available, or %0 if the SID was 1949 * computed successfully. 1950 */ 1951 int security_change_sid(u32 ssid, 1952 u32 tsid, 1953 u16 tclass, 1954 u32 *out_sid) 1955 { 1956 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1957 out_sid, false); 1958 } 1959 1960 static inline int convert_context_handle_invalid_context( 1961 struct policydb *policydb, 1962 struct context *context) 1963 { 1964 char *s; 1965 u32 len; 1966 1967 if (enforcing_enabled()) 1968 return -EINVAL; 1969 1970 if (!context_struct_to_string(policydb, context, &s, &len)) { 1971 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 1972 s); 1973 kfree(s); 1974 } 1975 return 0; 1976 } 1977 1978 /** 1979 * services_convert_context - Convert a security context across policies. 1980 * @args: populated convert_context_args struct 1981 * @oldc: original context 1982 * @newc: converted context 1983 * @gfp_flags: allocation flags 1984 * 1985 * Convert the values in the security context structure @oldc from the values 1986 * specified in the policy @args->oldp to the values specified in the policy 1987 * @args->newp, storing the new context in @newc, and verifying that the 1988 * context is valid under the new policy. 1989 */ 1990 int services_convert_context(struct convert_context_args *args, 1991 struct context *oldc, struct context *newc, 1992 gfp_t gfp_flags) 1993 { 1994 struct ocontext *oc; 1995 struct role_datum *role; 1996 struct type_datum *typdatum; 1997 struct user_datum *usrdatum; 1998 char *s; 1999 u32 len; 2000 int rc; 2001 2002 if (oldc->str) { 2003 s = kstrdup(oldc->str, gfp_flags); 2004 if (!s) 2005 return -ENOMEM; 2006 2007 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL); 2008 if (rc == -EINVAL) { 2009 /* 2010 * Retain string representation for later mapping. 2011 * 2012 * IMPORTANT: We need to copy the contents of oldc->str 2013 * back into s again because string_to_context_struct() 2014 * may have garbled it. 2015 */ 2016 memcpy(s, oldc->str, oldc->len); 2017 context_init(newc); 2018 newc->str = s; 2019 newc->len = oldc->len; 2020 return 0; 2021 } 2022 kfree(s); 2023 if (rc) { 2024 /* Other error condition, e.g. ENOMEM. */ 2025 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2026 oldc->str, -rc); 2027 return rc; 2028 } 2029 pr_info("SELinux: Context %s became valid (mapped).\n", 2030 oldc->str); 2031 return 0; 2032 } 2033 2034 context_init(newc); 2035 2036 /* Convert the user. */ 2037 usrdatum = symtab_search(&args->newp->p_users, 2038 sym_name(args->oldp, SYM_USERS, oldc->user - 1)); 2039 if (!usrdatum) 2040 goto bad; 2041 newc->user = usrdatum->value; 2042 2043 /* Convert the role. */ 2044 role = symtab_search(&args->newp->p_roles, 2045 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2046 if (!role) 2047 goto bad; 2048 newc->role = role->value; 2049 2050 /* Convert the type. */ 2051 typdatum = symtab_search(&args->newp->p_types, 2052 sym_name(args->oldp, SYM_TYPES, oldc->type - 1)); 2053 if (!typdatum) 2054 goto bad; 2055 newc->type = typdatum->value; 2056 2057 /* Convert the MLS fields if dealing with MLS policies */ 2058 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2059 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2060 if (rc) 2061 goto bad; 2062 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2063 /* 2064 * Switching between non-MLS and MLS policy: 2065 * ensure that the MLS fields of the context for all 2066 * existing entries in the sidtab are filled in with a 2067 * suitable default value, likely taken from one of the 2068 * initial SIDs. 2069 */ 2070 oc = args->newp->ocontexts[OCON_ISID]; 2071 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2072 oc = oc->next; 2073 if (!oc) { 2074 pr_err("SELinux: unable to look up" 2075 " the initial SIDs list\n"); 2076 goto bad; 2077 } 2078 rc = mls_range_set(newc, &oc->context[0].range); 2079 if (rc) 2080 goto bad; 2081 } 2082 2083 /* Check the validity of the new context. */ 2084 if (!policydb_context_isvalid(args->newp, newc)) { 2085 rc = convert_context_handle_invalid_context(args->oldp, oldc); 2086 if (rc) 2087 goto bad; 2088 } 2089 2090 return 0; 2091 bad: 2092 /* Map old representation to string and save it. */ 2093 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2094 if (rc) 2095 return rc; 2096 context_destroy(newc); 2097 newc->str = s; 2098 newc->len = len; 2099 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2100 newc->str); 2101 return 0; 2102 } 2103 2104 static void security_load_policycaps(struct selinux_policy *policy) 2105 { 2106 struct policydb *p; 2107 unsigned int i; 2108 struct ebitmap_node *node; 2109 2110 p = &policy->policydb; 2111 2112 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++) 2113 WRITE_ONCE(selinux_state.policycap[i], 2114 ebitmap_get_bit(&p->policycaps, i)); 2115 2116 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2117 pr_info("SELinux: policy capability %s=%d\n", 2118 selinux_policycap_names[i], 2119 ebitmap_get_bit(&p->policycaps, i)); 2120 2121 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2122 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2123 pr_info("SELinux: unknown policy capability %u\n", 2124 i); 2125 } 2126 } 2127 2128 static int security_preserve_bools(struct selinux_policy *oldpolicy, 2129 struct selinux_policy *newpolicy); 2130 2131 static void selinux_policy_free(struct selinux_policy *policy) 2132 { 2133 if (!policy) 2134 return; 2135 2136 sidtab_destroy(policy->sidtab); 2137 kfree(policy->map.mapping); 2138 policydb_destroy(&policy->policydb); 2139 kfree(policy->sidtab); 2140 kfree(policy); 2141 } 2142 2143 static void selinux_policy_cond_free(struct selinux_policy *policy) 2144 { 2145 cond_policydb_destroy_dup(&policy->policydb); 2146 kfree(policy); 2147 } 2148 2149 void selinux_policy_cancel(struct selinux_load_state *load_state) 2150 { 2151 struct selinux_state *state = &selinux_state; 2152 struct selinux_policy *oldpolicy; 2153 2154 oldpolicy = rcu_dereference_protected(state->policy, 2155 lockdep_is_held(&state->policy_mutex)); 2156 2157 sidtab_cancel_convert(oldpolicy->sidtab); 2158 selinux_policy_free(load_state->policy); 2159 kfree(load_state->convert_data); 2160 } 2161 2162 static void selinux_notify_policy_change(u32 seqno) 2163 { 2164 /* Flush external caches and notify userspace of policy load */ 2165 avc_ss_reset(seqno); 2166 selnl_notify_policyload(seqno); 2167 selinux_status_update_policyload(seqno); 2168 selinux_netlbl_cache_invalidate(); 2169 selinux_xfrm_notify_policyload(); 2170 selinux_ima_measure_state_locked(); 2171 } 2172 2173 void selinux_policy_commit(struct selinux_load_state *load_state) 2174 { 2175 struct selinux_state *state = &selinux_state; 2176 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2177 unsigned long flags; 2178 u32 seqno; 2179 2180 oldpolicy = rcu_dereference_protected(state->policy, 2181 lockdep_is_held(&state->policy_mutex)); 2182 2183 /* If switching between different policy types, log MLS status */ 2184 if (oldpolicy) { 2185 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2186 pr_info("SELinux: Disabling MLS support...\n"); 2187 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2188 pr_info("SELinux: Enabling MLS support...\n"); 2189 } 2190 2191 /* Set latest granting seqno for new policy. */ 2192 if (oldpolicy) 2193 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2194 else 2195 newpolicy->latest_granting = 1; 2196 seqno = newpolicy->latest_granting; 2197 2198 /* Install the new policy. */ 2199 if (oldpolicy) { 2200 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2201 rcu_assign_pointer(state->policy, newpolicy); 2202 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2203 } else { 2204 rcu_assign_pointer(state->policy, newpolicy); 2205 } 2206 2207 /* Load the policycaps from the new policy */ 2208 security_load_policycaps(newpolicy); 2209 2210 if (!selinux_initialized()) { 2211 /* 2212 * After first policy load, the security server is 2213 * marked as initialized and ready to handle requests and 2214 * any objects created prior to policy load are then labeled. 2215 */ 2216 selinux_mark_initialized(); 2217 selinux_complete_init(); 2218 } 2219 2220 /* Free the old policy */ 2221 synchronize_rcu(); 2222 selinux_policy_free(oldpolicy); 2223 kfree(load_state->convert_data); 2224 2225 /* Notify others of the policy change */ 2226 selinux_notify_policy_change(seqno); 2227 } 2228 2229 /** 2230 * security_load_policy - Load a security policy configuration. 2231 * @data: binary policy data 2232 * @len: length of data in bytes 2233 * @load_state: policy load state 2234 * 2235 * Load a new set of security policy configuration data, 2236 * validate it and convert the SID table as necessary. 2237 * This function will flush the access vector cache after 2238 * loading the new policy. 2239 */ 2240 int security_load_policy(void *data, size_t len, 2241 struct selinux_load_state *load_state) 2242 { 2243 struct selinux_state *state = &selinux_state; 2244 struct selinux_policy *newpolicy, *oldpolicy; 2245 struct selinux_policy_convert_data *convert_data; 2246 int rc = 0; 2247 struct policy_file file = { data, len }, *fp = &file; 2248 2249 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); 2250 if (!newpolicy) 2251 return -ENOMEM; 2252 2253 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); 2254 if (!newpolicy->sidtab) { 2255 rc = -ENOMEM; 2256 goto err_policy; 2257 } 2258 2259 rc = policydb_read(&newpolicy->policydb, fp); 2260 if (rc) 2261 goto err_sidtab; 2262 2263 newpolicy->policydb.len = len; 2264 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, 2265 &newpolicy->map); 2266 if (rc) 2267 goto err_policydb; 2268 2269 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); 2270 if (rc) { 2271 pr_err("SELinux: unable to load the initial SIDs\n"); 2272 goto err_mapping; 2273 } 2274 2275 if (!selinux_initialized()) { 2276 /* First policy load, so no need to preserve state from old policy */ 2277 load_state->policy = newpolicy; 2278 load_state->convert_data = NULL; 2279 return 0; 2280 } 2281 2282 oldpolicy = rcu_dereference_protected(state->policy, 2283 lockdep_is_held(&state->policy_mutex)); 2284 2285 /* Preserve active boolean values from the old policy */ 2286 rc = security_preserve_bools(oldpolicy, newpolicy); 2287 if (rc) { 2288 pr_err("SELinux: unable to preserve booleans\n"); 2289 goto err_free_isids; 2290 } 2291 2292 /* 2293 * Convert the internal representations of contexts 2294 * in the new SID table. 2295 */ 2296 2297 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2298 if (!convert_data) { 2299 rc = -ENOMEM; 2300 goto err_free_isids; 2301 } 2302 2303 convert_data->args.oldp = &oldpolicy->policydb; 2304 convert_data->args.newp = &newpolicy->policydb; 2305 2306 convert_data->sidtab_params.args = &convert_data->args; 2307 convert_data->sidtab_params.target = newpolicy->sidtab; 2308 2309 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); 2310 if (rc) { 2311 pr_err("SELinux: unable to convert the internal" 2312 " representation of contexts in the new SID" 2313 " table\n"); 2314 goto err_free_convert_data; 2315 } 2316 2317 load_state->policy = newpolicy; 2318 load_state->convert_data = convert_data; 2319 return 0; 2320 2321 err_free_convert_data: 2322 kfree(convert_data); 2323 err_free_isids: 2324 sidtab_destroy(newpolicy->sidtab); 2325 err_mapping: 2326 kfree(newpolicy->map.mapping); 2327 err_policydb: 2328 policydb_destroy(&newpolicy->policydb); 2329 err_sidtab: 2330 kfree(newpolicy->sidtab); 2331 err_policy: 2332 kfree(newpolicy); 2333 2334 return rc; 2335 } 2336 2337 /** 2338 * ocontext_to_sid - Helper to safely get sid for an ocontext 2339 * @sidtab: SID table 2340 * @c: ocontext structure 2341 * @index: index of the context entry (0 or 1) 2342 * @out_sid: pointer to the resulting SID value 2343 * 2344 * For all ocontexts except OCON_ISID the SID fields are populated 2345 * on-demand when needed. Since updating the SID value is an SMP-sensitive 2346 * operation, this helper must be used to do that safely. 2347 * 2348 * WARNING: This function may return -ESTALE, indicating that the caller 2349 * must retry the operation after re-acquiring the policy pointer! 2350 */ 2351 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, 2352 size_t index, u32 *out_sid) 2353 { 2354 int rc; 2355 u32 sid; 2356 2357 /* Ensure the associated sidtab entry is visible to this thread. */ 2358 sid = smp_load_acquire(&c->sid[index]); 2359 if (!sid) { 2360 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); 2361 if (rc) 2362 return rc; 2363 2364 /* 2365 * Ensure the new sidtab entry is visible to other threads 2366 * when they see the SID. 2367 */ 2368 smp_store_release(&c->sid[index], sid); 2369 } 2370 *out_sid = sid; 2371 return 0; 2372 } 2373 2374 /** 2375 * security_port_sid - Obtain the SID for a port. 2376 * @protocol: protocol number 2377 * @port: port number 2378 * @out_sid: security identifier 2379 */ 2380 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2381 { 2382 struct selinux_policy *policy; 2383 struct policydb *policydb; 2384 struct sidtab *sidtab; 2385 struct ocontext *c; 2386 int rc; 2387 2388 if (!selinux_initialized()) { 2389 *out_sid = SECINITSID_PORT; 2390 return 0; 2391 } 2392 2393 retry: 2394 rc = 0; 2395 rcu_read_lock(); 2396 policy = rcu_dereference(selinux_state.policy); 2397 policydb = &policy->policydb; 2398 sidtab = policy->sidtab; 2399 2400 c = policydb->ocontexts[OCON_PORT]; 2401 while (c) { 2402 if (c->u.port.protocol == protocol && 2403 c->u.port.low_port <= port && 2404 c->u.port.high_port >= port) 2405 break; 2406 c = c->next; 2407 } 2408 2409 if (c) { 2410 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2411 if (rc == -ESTALE) { 2412 rcu_read_unlock(); 2413 goto retry; 2414 } 2415 if (rc) 2416 goto out; 2417 } else { 2418 *out_sid = SECINITSID_PORT; 2419 } 2420 2421 out: 2422 rcu_read_unlock(); 2423 return rc; 2424 } 2425 2426 /** 2427 * security_ib_pkey_sid - Obtain the SID for a pkey. 2428 * @subnet_prefix: Subnet Prefix 2429 * @pkey_num: pkey number 2430 * @out_sid: security identifier 2431 */ 2432 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2433 { 2434 struct selinux_policy *policy; 2435 struct policydb *policydb; 2436 struct sidtab *sidtab; 2437 struct ocontext *c; 2438 int rc; 2439 2440 if (!selinux_initialized()) { 2441 *out_sid = SECINITSID_UNLABELED; 2442 return 0; 2443 } 2444 2445 retry: 2446 rc = 0; 2447 rcu_read_lock(); 2448 policy = rcu_dereference(selinux_state.policy); 2449 policydb = &policy->policydb; 2450 sidtab = policy->sidtab; 2451 2452 c = policydb->ocontexts[OCON_IBPKEY]; 2453 while (c) { 2454 if (c->u.ibpkey.low_pkey <= pkey_num && 2455 c->u.ibpkey.high_pkey >= pkey_num && 2456 c->u.ibpkey.subnet_prefix == subnet_prefix) 2457 break; 2458 2459 c = c->next; 2460 } 2461 2462 if (c) { 2463 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2464 if (rc == -ESTALE) { 2465 rcu_read_unlock(); 2466 goto retry; 2467 } 2468 if (rc) 2469 goto out; 2470 } else 2471 *out_sid = SECINITSID_UNLABELED; 2472 2473 out: 2474 rcu_read_unlock(); 2475 return rc; 2476 } 2477 2478 /** 2479 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2480 * @dev_name: device name 2481 * @port_num: port number 2482 * @out_sid: security identifier 2483 */ 2484 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) 2485 { 2486 struct selinux_policy *policy; 2487 struct policydb *policydb; 2488 struct sidtab *sidtab; 2489 struct ocontext *c; 2490 int rc; 2491 2492 if (!selinux_initialized()) { 2493 *out_sid = SECINITSID_UNLABELED; 2494 return 0; 2495 } 2496 2497 retry: 2498 rc = 0; 2499 rcu_read_lock(); 2500 policy = rcu_dereference(selinux_state.policy); 2501 policydb = &policy->policydb; 2502 sidtab = policy->sidtab; 2503 2504 c = policydb->ocontexts[OCON_IBENDPORT]; 2505 while (c) { 2506 if (c->u.ibendport.port == port_num && 2507 !strncmp(c->u.ibendport.dev_name, 2508 dev_name, 2509 IB_DEVICE_NAME_MAX)) 2510 break; 2511 2512 c = c->next; 2513 } 2514 2515 if (c) { 2516 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2517 if (rc == -ESTALE) { 2518 rcu_read_unlock(); 2519 goto retry; 2520 } 2521 if (rc) 2522 goto out; 2523 } else 2524 *out_sid = SECINITSID_UNLABELED; 2525 2526 out: 2527 rcu_read_unlock(); 2528 return rc; 2529 } 2530 2531 /** 2532 * security_netif_sid - Obtain the SID for a network interface. 2533 * @name: interface name 2534 * @if_sid: interface SID 2535 */ 2536 int security_netif_sid(char *name, u32 *if_sid) 2537 { 2538 struct selinux_policy *policy; 2539 struct policydb *policydb; 2540 struct sidtab *sidtab; 2541 int rc; 2542 struct ocontext *c; 2543 2544 if (!selinux_initialized()) { 2545 *if_sid = SECINITSID_NETIF; 2546 return 0; 2547 } 2548 2549 retry: 2550 rc = 0; 2551 rcu_read_lock(); 2552 policy = rcu_dereference(selinux_state.policy); 2553 policydb = &policy->policydb; 2554 sidtab = policy->sidtab; 2555 2556 c = policydb->ocontexts[OCON_NETIF]; 2557 while (c) { 2558 if (strcmp(name, c->u.name) == 0) 2559 break; 2560 c = c->next; 2561 } 2562 2563 if (c) { 2564 rc = ocontext_to_sid(sidtab, c, 0, if_sid); 2565 if (rc == -ESTALE) { 2566 rcu_read_unlock(); 2567 goto retry; 2568 } 2569 if (rc) 2570 goto out; 2571 } else 2572 *if_sid = SECINITSID_NETIF; 2573 2574 out: 2575 rcu_read_unlock(); 2576 return rc; 2577 } 2578 2579 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2580 { 2581 int i, fail = 0; 2582 2583 for (i = 0; i < 4; i++) 2584 if (addr[i] != (input[i] & mask[i])) { 2585 fail = 1; 2586 break; 2587 } 2588 2589 return !fail; 2590 } 2591 2592 /** 2593 * security_node_sid - Obtain the SID for a node (host). 2594 * @domain: communication domain aka address family 2595 * @addrp: address 2596 * @addrlen: address length in bytes 2597 * @out_sid: security identifier 2598 */ 2599 int security_node_sid(u16 domain, 2600 void *addrp, 2601 u32 addrlen, 2602 u32 *out_sid) 2603 { 2604 struct selinux_policy *policy; 2605 struct policydb *policydb; 2606 struct sidtab *sidtab; 2607 int rc; 2608 struct ocontext *c; 2609 2610 if (!selinux_initialized()) { 2611 *out_sid = SECINITSID_NODE; 2612 return 0; 2613 } 2614 2615 retry: 2616 rcu_read_lock(); 2617 policy = rcu_dereference(selinux_state.policy); 2618 policydb = &policy->policydb; 2619 sidtab = policy->sidtab; 2620 2621 switch (domain) { 2622 case AF_INET: { 2623 u32 addr; 2624 2625 rc = -EINVAL; 2626 if (addrlen != sizeof(u32)) 2627 goto out; 2628 2629 addr = *((u32 *)addrp); 2630 2631 c = policydb->ocontexts[OCON_NODE]; 2632 while (c) { 2633 if (c->u.node.addr == (addr & c->u.node.mask)) 2634 break; 2635 c = c->next; 2636 } 2637 break; 2638 } 2639 2640 case AF_INET6: 2641 rc = -EINVAL; 2642 if (addrlen != sizeof(u64) * 2) 2643 goto out; 2644 c = policydb->ocontexts[OCON_NODE6]; 2645 while (c) { 2646 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2647 c->u.node6.mask)) 2648 break; 2649 c = c->next; 2650 } 2651 break; 2652 2653 default: 2654 rc = 0; 2655 *out_sid = SECINITSID_NODE; 2656 goto out; 2657 } 2658 2659 if (c) { 2660 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2661 if (rc == -ESTALE) { 2662 rcu_read_unlock(); 2663 goto retry; 2664 } 2665 if (rc) 2666 goto out; 2667 } else { 2668 *out_sid = SECINITSID_NODE; 2669 } 2670 2671 rc = 0; 2672 out: 2673 rcu_read_unlock(); 2674 return rc; 2675 } 2676 2677 #define SIDS_NEL 25 2678 2679 /** 2680 * security_get_user_sids - Obtain reachable SIDs for a user. 2681 * @fromsid: starting SID 2682 * @username: username 2683 * @sids: array of reachable SIDs for user 2684 * @nel: number of elements in @sids 2685 * 2686 * Generate the set of SIDs for legal security contexts 2687 * for a given user that can be reached by @fromsid. 2688 * Set *@sids to point to a dynamically allocated 2689 * array containing the set of SIDs. Set *@nel to the 2690 * number of elements in the array. 2691 */ 2692 2693 int security_get_user_sids(u32 fromsid, 2694 char *username, 2695 u32 **sids, 2696 u32 *nel) 2697 { 2698 struct selinux_policy *policy; 2699 struct policydb *policydb; 2700 struct sidtab *sidtab; 2701 struct context *fromcon, usercon; 2702 u32 *mysids = NULL, *mysids2, sid; 2703 u32 i, j, mynel, maxnel = SIDS_NEL; 2704 struct user_datum *user; 2705 struct role_datum *role; 2706 struct ebitmap_node *rnode, *tnode; 2707 int rc; 2708 2709 *sids = NULL; 2710 *nel = 0; 2711 2712 if (!selinux_initialized()) 2713 return 0; 2714 2715 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2716 if (!mysids) 2717 return -ENOMEM; 2718 2719 retry: 2720 mynel = 0; 2721 rcu_read_lock(); 2722 policy = rcu_dereference(selinux_state.policy); 2723 policydb = &policy->policydb; 2724 sidtab = policy->sidtab; 2725 2726 context_init(&usercon); 2727 2728 rc = -EINVAL; 2729 fromcon = sidtab_search(sidtab, fromsid); 2730 if (!fromcon) 2731 goto out_unlock; 2732 2733 rc = -EINVAL; 2734 user = symtab_search(&policydb->p_users, username); 2735 if (!user) 2736 goto out_unlock; 2737 2738 usercon.user = user->value; 2739 2740 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2741 role = policydb->role_val_to_struct[i]; 2742 usercon.role = i + 1; 2743 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2744 usercon.type = j + 1; 2745 2746 if (mls_setup_user_range(policydb, fromcon, user, 2747 &usercon)) 2748 continue; 2749 2750 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2751 if (rc == -ESTALE) { 2752 rcu_read_unlock(); 2753 goto retry; 2754 } 2755 if (rc) 2756 goto out_unlock; 2757 if (mynel < maxnel) { 2758 mysids[mynel++] = sid; 2759 } else { 2760 rc = -ENOMEM; 2761 maxnel += SIDS_NEL; 2762 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2763 if (!mysids2) 2764 goto out_unlock; 2765 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2766 kfree(mysids); 2767 mysids = mysids2; 2768 mysids[mynel++] = sid; 2769 } 2770 } 2771 } 2772 rc = 0; 2773 out_unlock: 2774 rcu_read_unlock(); 2775 if (rc || !mynel) { 2776 kfree(mysids); 2777 return rc; 2778 } 2779 2780 rc = -ENOMEM; 2781 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2782 if (!mysids2) { 2783 kfree(mysids); 2784 return rc; 2785 } 2786 for (i = 0, j = 0; i < mynel; i++) { 2787 struct av_decision dummy_avd; 2788 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2789 SECCLASS_PROCESS, /* kernel value */ 2790 PROCESS__TRANSITION, AVC_STRICT, 2791 &dummy_avd); 2792 if (!rc) 2793 mysids2[j++] = mysids[i]; 2794 cond_resched(); 2795 } 2796 kfree(mysids); 2797 *sids = mysids2; 2798 *nel = j; 2799 return 0; 2800 } 2801 2802 /** 2803 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2804 * @policy: policy 2805 * @fstype: filesystem type 2806 * @path: path from root of mount 2807 * @orig_sclass: file security class 2808 * @sid: SID for path 2809 * 2810 * Obtain a SID to use for a file in a filesystem that 2811 * cannot support xattr or use a fixed labeling behavior like 2812 * transition SIDs or task SIDs. 2813 * 2814 * WARNING: This function may return -ESTALE, indicating that the caller 2815 * must retry the operation after re-acquiring the policy pointer! 2816 */ 2817 static inline int __security_genfs_sid(struct selinux_policy *policy, 2818 const char *fstype, 2819 const char *path, 2820 u16 orig_sclass, 2821 u32 *sid) 2822 { 2823 struct policydb *policydb = &policy->policydb; 2824 struct sidtab *sidtab = policy->sidtab; 2825 int len; 2826 u16 sclass; 2827 struct genfs *genfs; 2828 struct ocontext *c; 2829 int cmp = 0; 2830 2831 while (path[0] == '/' && path[1] == '/') 2832 path++; 2833 2834 sclass = unmap_class(&policy->map, orig_sclass); 2835 *sid = SECINITSID_UNLABELED; 2836 2837 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2838 cmp = strcmp(fstype, genfs->fstype); 2839 if (cmp <= 0) 2840 break; 2841 } 2842 2843 if (!genfs || cmp) 2844 return -ENOENT; 2845 2846 for (c = genfs->head; c; c = c->next) { 2847 len = strlen(c->u.name); 2848 if ((!c->v.sclass || sclass == c->v.sclass) && 2849 (strncmp(c->u.name, path, len) == 0)) 2850 break; 2851 } 2852 2853 if (!c) 2854 return -ENOENT; 2855 2856 return ocontext_to_sid(sidtab, c, 0, sid); 2857 } 2858 2859 /** 2860 * security_genfs_sid - Obtain a SID for a file in a filesystem 2861 * @fstype: filesystem type 2862 * @path: path from root of mount 2863 * @orig_sclass: file security class 2864 * @sid: SID for path 2865 * 2866 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2867 * it afterward. 2868 */ 2869 int security_genfs_sid(const char *fstype, 2870 const char *path, 2871 u16 orig_sclass, 2872 u32 *sid) 2873 { 2874 struct selinux_policy *policy; 2875 int retval; 2876 2877 if (!selinux_initialized()) { 2878 *sid = SECINITSID_UNLABELED; 2879 return 0; 2880 } 2881 2882 do { 2883 rcu_read_lock(); 2884 policy = rcu_dereference(selinux_state.policy); 2885 retval = __security_genfs_sid(policy, fstype, path, 2886 orig_sclass, sid); 2887 rcu_read_unlock(); 2888 } while (retval == -ESTALE); 2889 return retval; 2890 } 2891 2892 int selinux_policy_genfs_sid(struct selinux_policy *policy, 2893 const char *fstype, 2894 const char *path, 2895 u16 orig_sclass, 2896 u32 *sid) 2897 { 2898 /* no lock required, policy is not yet accessible by other threads */ 2899 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2900 } 2901 2902 /** 2903 * security_fs_use - Determine how to handle labeling for a filesystem. 2904 * @sb: superblock in question 2905 */ 2906 int security_fs_use(struct super_block *sb) 2907 { 2908 struct selinux_policy *policy; 2909 struct policydb *policydb; 2910 struct sidtab *sidtab; 2911 int rc; 2912 struct ocontext *c; 2913 struct superblock_security_struct *sbsec = selinux_superblock(sb); 2914 const char *fstype = sb->s_type->name; 2915 2916 if (!selinux_initialized()) { 2917 sbsec->behavior = SECURITY_FS_USE_NONE; 2918 sbsec->sid = SECINITSID_UNLABELED; 2919 return 0; 2920 } 2921 2922 retry: 2923 rcu_read_lock(); 2924 policy = rcu_dereference(selinux_state.policy); 2925 policydb = &policy->policydb; 2926 sidtab = policy->sidtab; 2927 2928 c = policydb->ocontexts[OCON_FSUSE]; 2929 while (c) { 2930 if (strcmp(fstype, c->u.name) == 0) 2931 break; 2932 c = c->next; 2933 } 2934 2935 if (c) { 2936 sbsec->behavior = c->v.behavior; 2937 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); 2938 if (rc == -ESTALE) { 2939 rcu_read_unlock(); 2940 goto retry; 2941 } 2942 if (rc) 2943 goto out; 2944 } else { 2945 rc = __security_genfs_sid(policy, fstype, "/", 2946 SECCLASS_DIR, &sbsec->sid); 2947 if (rc == -ESTALE) { 2948 rcu_read_unlock(); 2949 goto retry; 2950 } 2951 if (rc) { 2952 sbsec->behavior = SECURITY_FS_USE_NONE; 2953 rc = 0; 2954 } else { 2955 sbsec->behavior = SECURITY_FS_USE_GENFS; 2956 } 2957 } 2958 2959 out: 2960 rcu_read_unlock(); 2961 return rc; 2962 } 2963 2964 int security_get_bools(struct selinux_policy *policy, 2965 u32 *len, char ***names, int **values) 2966 { 2967 struct policydb *policydb; 2968 u32 i; 2969 int rc; 2970 2971 policydb = &policy->policydb; 2972 2973 *names = NULL; 2974 *values = NULL; 2975 2976 rc = 0; 2977 *len = policydb->p_bools.nprim; 2978 if (!*len) 2979 goto out; 2980 2981 rc = -ENOMEM; 2982 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2983 if (!*names) 2984 goto err; 2985 2986 rc = -ENOMEM; 2987 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2988 if (!*values) 2989 goto err; 2990 2991 for (i = 0; i < *len; i++) { 2992 (*values)[i] = policydb->bool_val_to_struct[i]->state; 2993 2994 rc = -ENOMEM; 2995 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 2996 GFP_ATOMIC); 2997 if (!(*names)[i]) 2998 goto err; 2999 } 3000 rc = 0; 3001 out: 3002 return rc; 3003 err: 3004 if (*names) { 3005 for (i = 0; i < *len; i++) 3006 kfree((*names)[i]); 3007 kfree(*names); 3008 } 3009 kfree(*values); 3010 *len = 0; 3011 *names = NULL; 3012 *values = NULL; 3013 goto out; 3014 } 3015 3016 3017 int security_set_bools(u32 len, int *values) 3018 { 3019 struct selinux_state *state = &selinux_state; 3020 struct selinux_policy *newpolicy, *oldpolicy; 3021 int rc; 3022 u32 i, seqno = 0; 3023 3024 if (!selinux_initialized()) 3025 return -EINVAL; 3026 3027 oldpolicy = rcu_dereference_protected(state->policy, 3028 lockdep_is_held(&state->policy_mutex)); 3029 3030 /* Consistency check on number of booleans, should never fail */ 3031 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) 3032 return -EINVAL; 3033 3034 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); 3035 if (!newpolicy) 3036 return -ENOMEM; 3037 3038 /* 3039 * Deep copy only the parts of the policydb that might be 3040 * modified as a result of changing booleans. 3041 */ 3042 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); 3043 if (rc) { 3044 kfree(newpolicy); 3045 return -ENOMEM; 3046 } 3047 3048 /* Update the boolean states in the copy */ 3049 for (i = 0; i < len; i++) { 3050 int new_state = !!values[i]; 3051 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; 3052 3053 if (new_state != old_state) { 3054 audit_log(audit_context(), GFP_ATOMIC, 3055 AUDIT_MAC_CONFIG_CHANGE, 3056 "bool=%s val=%d old_val=%d auid=%u ses=%u", 3057 sym_name(&newpolicy->policydb, SYM_BOOLS, i), 3058 new_state, 3059 old_state, 3060 from_kuid(&init_user_ns, audit_get_loginuid(current)), 3061 audit_get_sessionid(current)); 3062 newpolicy->policydb.bool_val_to_struct[i]->state = new_state; 3063 } 3064 } 3065 3066 /* Re-evaluate the conditional rules in the copy */ 3067 evaluate_cond_nodes(&newpolicy->policydb); 3068 3069 /* Set latest granting seqno for new policy */ 3070 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 3071 seqno = newpolicy->latest_granting; 3072 3073 /* Install the new policy */ 3074 rcu_assign_pointer(state->policy, newpolicy); 3075 3076 /* 3077 * Free the conditional portions of the old policydb 3078 * that were copied for the new policy, and the oldpolicy 3079 * structure itself but not what it references. 3080 */ 3081 synchronize_rcu(); 3082 selinux_policy_cond_free(oldpolicy); 3083 3084 /* Notify others of the policy change */ 3085 selinux_notify_policy_change(seqno); 3086 return 0; 3087 } 3088 3089 int security_get_bool_value(u32 index) 3090 { 3091 struct selinux_policy *policy; 3092 struct policydb *policydb; 3093 int rc; 3094 u32 len; 3095 3096 if (!selinux_initialized()) 3097 return 0; 3098 3099 rcu_read_lock(); 3100 policy = rcu_dereference(selinux_state.policy); 3101 policydb = &policy->policydb; 3102 3103 rc = -EFAULT; 3104 len = policydb->p_bools.nprim; 3105 if (index >= len) 3106 goto out; 3107 3108 rc = policydb->bool_val_to_struct[index]->state; 3109 out: 3110 rcu_read_unlock(); 3111 return rc; 3112 } 3113 3114 static int security_preserve_bools(struct selinux_policy *oldpolicy, 3115 struct selinux_policy *newpolicy) 3116 { 3117 int rc, *bvalues = NULL; 3118 char **bnames = NULL; 3119 struct cond_bool_datum *booldatum; 3120 u32 i, nbools = 0; 3121 3122 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); 3123 if (rc) 3124 goto out; 3125 for (i = 0; i < nbools; i++) { 3126 booldatum = symtab_search(&newpolicy->policydb.p_bools, 3127 bnames[i]); 3128 if (booldatum) 3129 booldatum->state = bvalues[i]; 3130 } 3131 evaluate_cond_nodes(&newpolicy->policydb); 3132 3133 out: 3134 if (bnames) { 3135 for (i = 0; i < nbools; i++) 3136 kfree(bnames[i]); 3137 } 3138 kfree(bnames); 3139 kfree(bvalues); 3140 return rc; 3141 } 3142 3143 /* 3144 * security_sid_mls_copy() - computes a new sid based on the given 3145 * sid and the mls portion of mls_sid. 3146 */ 3147 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 3148 { 3149 struct selinux_policy *policy; 3150 struct policydb *policydb; 3151 struct sidtab *sidtab; 3152 struct context *context1; 3153 struct context *context2; 3154 struct context newcon; 3155 char *s; 3156 u32 len; 3157 int rc; 3158 3159 if (!selinux_initialized()) { 3160 *new_sid = sid; 3161 return 0; 3162 } 3163 3164 retry: 3165 rc = 0; 3166 context_init(&newcon); 3167 3168 rcu_read_lock(); 3169 policy = rcu_dereference(selinux_state.policy); 3170 policydb = &policy->policydb; 3171 sidtab = policy->sidtab; 3172 3173 if (!policydb->mls_enabled) { 3174 *new_sid = sid; 3175 goto out_unlock; 3176 } 3177 3178 rc = -EINVAL; 3179 context1 = sidtab_search(sidtab, sid); 3180 if (!context1) { 3181 pr_err("SELinux: %s: unrecognized SID %d\n", 3182 __func__, sid); 3183 goto out_unlock; 3184 } 3185 3186 rc = -EINVAL; 3187 context2 = sidtab_search(sidtab, mls_sid); 3188 if (!context2) { 3189 pr_err("SELinux: %s: unrecognized SID %d\n", 3190 __func__, mls_sid); 3191 goto out_unlock; 3192 } 3193 3194 newcon.user = context1->user; 3195 newcon.role = context1->role; 3196 newcon.type = context1->type; 3197 rc = mls_context_cpy(&newcon, context2); 3198 if (rc) 3199 goto out_unlock; 3200 3201 /* Check the validity of the new context. */ 3202 if (!policydb_context_isvalid(policydb, &newcon)) { 3203 rc = convert_context_handle_invalid_context(policydb, 3204 &newcon); 3205 if (rc) { 3206 if (!context_struct_to_string(policydb, &newcon, &s, 3207 &len)) { 3208 struct audit_buffer *ab; 3209 3210 ab = audit_log_start(audit_context(), 3211 GFP_ATOMIC, 3212 AUDIT_SELINUX_ERR); 3213 audit_log_format(ab, 3214 "op=security_sid_mls_copy invalid_context="); 3215 /* don't record NUL with untrusted strings */ 3216 audit_log_n_untrustedstring(ab, s, len - 1); 3217 audit_log_end(ab); 3218 kfree(s); 3219 } 3220 goto out_unlock; 3221 } 3222 } 3223 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3224 if (rc == -ESTALE) { 3225 rcu_read_unlock(); 3226 context_destroy(&newcon); 3227 goto retry; 3228 } 3229 out_unlock: 3230 rcu_read_unlock(); 3231 context_destroy(&newcon); 3232 return rc; 3233 } 3234 3235 /** 3236 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3237 * @nlbl_sid: NetLabel SID 3238 * @nlbl_type: NetLabel labeling protocol type 3239 * @xfrm_sid: XFRM SID 3240 * @peer_sid: network peer sid 3241 * 3242 * Description: 3243 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3244 * resolved into a single SID it is returned via @peer_sid and the function 3245 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3246 * returns a negative value. A table summarizing the behavior is below: 3247 * 3248 * | function return | @sid 3249 * ------------------------------+-----------------+----------------- 3250 * no peer labels | 0 | SECSID_NULL 3251 * single peer label | 0 | <peer_label> 3252 * multiple, consistent labels | 0 | <peer_label> 3253 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3254 * 3255 */ 3256 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 3257 u32 xfrm_sid, 3258 u32 *peer_sid) 3259 { 3260 struct selinux_policy *policy; 3261 struct policydb *policydb; 3262 struct sidtab *sidtab; 3263 int rc; 3264 struct context *nlbl_ctx; 3265 struct context *xfrm_ctx; 3266 3267 *peer_sid = SECSID_NULL; 3268 3269 /* handle the common (which also happens to be the set of easy) cases 3270 * right away, these two if statements catch everything involving a 3271 * single or absent peer SID/label */ 3272 if (xfrm_sid == SECSID_NULL) { 3273 *peer_sid = nlbl_sid; 3274 return 0; 3275 } 3276 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3277 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3278 * is present */ 3279 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3280 *peer_sid = xfrm_sid; 3281 return 0; 3282 } 3283 3284 if (!selinux_initialized()) 3285 return 0; 3286 3287 rcu_read_lock(); 3288 policy = rcu_dereference(selinux_state.policy); 3289 policydb = &policy->policydb; 3290 sidtab = policy->sidtab; 3291 3292 /* 3293 * We don't need to check initialized here since the only way both 3294 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3295 * security server was initialized and state->initialized was true. 3296 */ 3297 if (!policydb->mls_enabled) { 3298 rc = 0; 3299 goto out; 3300 } 3301 3302 rc = -EINVAL; 3303 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3304 if (!nlbl_ctx) { 3305 pr_err("SELinux: %s: unrecognized SID %d\n", 3306 __func__, nlbl_sid); 3307 goto out; 3308 } 3309 rc = -EINVAL; 3310 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3311 if (!xfrm_ctx) { 3312 pr_err("SELinux: %s: unrecognized SID %d\n", 3313 __func__, xfrm_sid); 3314 goto out; 3315 } 3316 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3317 if (rc) 3318 goto out; 3319 3320 /* at present NetLabel SIDs/labels really only carry MLS 3321 * information so if the MLS portion of the NetLabel SID 3322 * matches the MLS portion of the labeled XFRM SID/label 3323 * then pass along the XFRM SID as it is the most 3324 * expressive */ 3325 *peer_sid = xfrm_sid; 3326 out: 3327 rcu_read_unlock(); 3328 return rc; 3329 } 3330 3331 static int get_classes_callback(void *k, void *d, void *args) 3332 { 3333 struct class_datum *datum = d; 3334 char *name = k, **classes = args; 3335 int value = datum->value - 1; 3336 3337 classes[value] = kstrdup(name, GFP_ATOMIC); 3338 if (!classes[value]) 3339 return -ENOMEM; 3340 3341 return 0; 3342 } 3343 3344 int security_get_classes(struct selinux_policy *policy, 3345 char ***classes, int *nclasses) 3346 { 3347 struct policydb *policydb; 3348 int rc; 3349 3350 policydb = &policy->policydb; 3351 3352 rc = -ENOMEM; 3353 *nclasses = policydb->p_classes.nprim; 3354 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3355 if (!*classes) 3356 goto out; 3357 3358 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3359 *classes); 3360 if (rc) { 3361 int i; 3362 for (i = 0; i < *nclasses; i++) 3363 kfree((*classes)[i]); 3364 kfree(*classes); 3365 } 3366 3367 out: 3368 return rc; 3369 } 3370 3371 static int get_permissions_callback(void *k, void *d, void *args) 3372 { 3373 struct perm_datum *datum = d; 3374 char *name = k, **perms = args; 3375 int value = datum->value - 1; 3376 3377 perms[value] = kstrdup(name, GFP_ATOMIC); 3378 if (!perms[value]) 3379 return -ENOMEM; 3380 3381 return 0; 3382 } 3383 3384 int security_get_permissions(struct selinux_policy *policy, 3385 char *class, char ***perms, int *nperms) 3386 { 3387 struct policydb *policydb; 3388 int rc, i; 3389 struct class_datum *match; 3390 3391 policydb = &policy->policydb; 3392 3393 rc = -EINVAL; 3394 match = symtab_search(&policydb->p_classes, class); 3395 if (!match) { 3396 pr_err("SELinux: %s: unrecognized class %s\n", 3397 __func__, class); 3398 goto out; 3399 } 3400 3401 rc = -ENOMEM; 3402 *nperms = match->permissions.nprim; 3403 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3404 if (!*perms) 3405 goto out; 3406 3407 if (match->comdatum) { 3408 rc = hashtab_map(&match->comdatum->permissions.table, 3409 get_permissions_callback, *perms); 3410 if (rc) 3411 goto err; 3412 } 3413 3414 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3415 *perms); 3416 if (rc) 3417 goto err; 3418 3419 out: 3420 return rc; 3421 3422 err: 3423 for (i = 0; i < *nperms; i++) 3424 kfree((*perms)[i]); 3425 kfree(*perms); 3426 return rc; 3427 } 3428 3429 int security_get_reject_unknown(void) 3430 { 3431 struct selinux_policy *policy; 3432 int value; 3433 3434 if (!selinux_initialized()) 3435 return 0; 3436 3437 rcu_read_lock(); 3438 policy = rcu_dereference(selinux_state.policy); 3439 value = policy->policydb.reject_unknown; 3440 rcu_read_unlock(); 3441 return value; 3442 } 3443 3444 int security_get_allow_unknown(void) 3445 { 3446 struct selinux_policy *policy; 3447 int value; 3448 3449 if (!selinux_initialized()) 3450 return 0; 3451 3452 rcu_read_lock(); 3453 policy = rcu_dereference(selinux_state.policy); 3454 value = policy->policydb.allow_unknown; 3455 rcu_read_unlock(); 3456 return value; 3457 } 3458 3459 /** 3460 * security_policycap_supported - Check for a specific policy capability 3461 * @req_cap: capability 3462 * 3463 * Description: 3464 * This function queries the currently loaded policy to see if it supports the 3465 * capability specified by @req_cap. Returns true (1) if the capability is 3466 * supported, false (0) if it isn't supported. 3467 * 3468 */ 3469 int security_policycap_supported(unsigned int req_cap) 3470 { 3471 struct selinux_policy *policy; 3472 int rc; 3473 3474 if (!selinux_initialized()) 3475 return 0; 3476 3477 rcu_read_lock(); 3478 policy = rcu_dereference(selinux_state.policy); 3479 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3480 rcu_read_unlock(); 3481 3482 return rc; 3483 } 3484 3485 struct selinux_audit_rule { 3486 u32 au_seqno; 3487 struct context au_ctxt; 3488 }; 3489 3490 void selinux_audit_rule_free(void *vrule) 3491 { 3492 struct selinux_audit_rule *rule = vrule; 3493 3494 if (rule) { 3495 context_destroy(&rule->au_ctxt); 3496 kfree(rule); 3497 } 3498 } 3499 3500 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3501 { 3502 struct selinux_state *state = &selinux_state; 3503 struct selinux_policy *policy; 3504 struct policydb *policydb; 3505 struct selinux_audit_rule *tmprule; 3506 struct role_datum *roledatum; 3507 struct type_datum *typedatum; 3508 struct user_datum *userdatum; 3509 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3510 int rc = 0; 3511 3512 *rule = NULL; 3513 3514 if (!selinux_initialized()) 3515 return -EOPNOTSUPP; 3516 3517 switch (field) { 3518 case AUDIT_SUBJ_USER: 3519 case AUDIT_SUBJ_ROLE: 3520 case AUDIT_SUBJ_TYPE: 3521 case AUDIT_OBJ_USER: 3522 case AUDIT_OBJ_ROLE: 3523 case AUDIT_OBJ_TYPE: 3524 /* only 'equals' and 'not equals' fit user, role, and type */ 3525 if (op != Audit_equal && op != Audit_not_equal) 3526 return -EINVAL; 3527 break; 3528 case AUDIT_SUBJ_SEN: 3529 case AUDIT_SUBJ_CLR: 3530 case AUDIT_OBJ_LEV_LOW: 3531 case AUDIT_OBJ_LEV_HIGH: 3532 /* we do not allow a range, indicated by the presence of '-' */ 3533 if (strchr(rulestr, '-')) 3534 return -EINVAL; 3535 break; 3536 default: 3537 /* only the above fields are valid */ 3538 return -EINVAL; 3539 } 3540 3541 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3542 if (!tmprule) 3543 return -ENOMEM; 3544 context_init(&tmprule->au_ctxt); 3545 3546 rcu_read_lock(); 3547 policy = rcu_dereference(state->policy); 3548 policydb = &policy->policydb; 3549 tmprule->au_seqno = policy->latest_granting; 3550 switch (field) { 3551 case AUDIT_SUBJ_USER: 3552 case AUDIT_OBJ_USER: 3553 userdatum = symtab_search(&policydb->p_users, rulestr); 3554 if (!userdatum) { 3555 rc = -EINVAL; 3556 goto err; 3557 } 3558 tmprule->au_ctxt.user = userdatum->value; 3559 break; 3560 case AUDIT_SUBJ_ROLE: 3561 case AUDIT_OBJ_ROLE: 3562 roledatum = symtab_search(&policydb->p_roles, rulestr); 3563 if (!roledatum) { 3564 rc = -EINVAL; 3565 goto err; 3566 } 3567 tmprule->au_ctxt.role = roledatum->value; 3568 break; 3569 case AUDIT_SUBJ_TYPE: 3570 case AUDIT_OBJ_TYPE: 3571 typedatum = symtab_search(&policydb->p_types, rulestr); 3572 if (!typedatum) { 3573 rc = -EINVAL; 3574 goto err; 3575 } 3576 tmprule->au_ctxt.type = typedatum->value; 3577 break; 3578 case AUDIT_SUBJ_SEN: 3579 case AUDIT_SUBJ_CLR: 3580 case AUDIT_OBJ_LEV_LOW: 3581 case AUDIT_OBJ_LEV_HIGH: 3582 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3583 GFP_ATOMIC); 3584 if (rc) 3585 goto err; 3586 break; 3587 } 3588 rcu_read_unlock(); 3589 3590 *rule = tmprule; 3591 return 0; 3592 3593 err: 3594 rcu_read_unlock(); 3595 selinux_audit_rule_free(tmprule); 3596 *rule = NULL; 3597 return rc; 3598 } 3599 3600 /* Check to see if the rule contains any selinux fields */ 3601 int selinux_audit_rule_known(struct audit_krule *rule) 3602 { 3603 int i; 3604 3605 for (i = 0; i < rule->field_count; i++) { 3606 struct audit_field *f = &rule->fields[i]; 3607 switch (f->type) { 3608 case AUDIT_SUBJ_USER: 3609 case AUDIT_SUBJ_ROLE: 3610 case AUDIT_SUBJ_TYPE: 3611 case AUDIT_SUBJ_SEN: 3612 case AUDIT_SUBJ_CLR: 3613 case AUDIT_OBJ_USER: 3614 case AUDIT_OBJ_ROLE: 3615 case AUDIT_OBJ_TYPE: 3616 case AUDIT_OBJ_LEV_LOW: 3617 case AUDIT_OBJ_LEV_HIGH: 3618 return 1; 3619 } 3620 } 3621 3622 return 0; 3623 } 3624 3625 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) 3626 { 3627 struct selinux_state *state = &selinux_state; 3628 struct selinux_policy *policy; 3629 struct context *ctxt; 3630 struct mls_level *level; 3631 struct selinux_audit_rule *rule = vrule; 3632 int match = 0; 3633 3634 if (unlikely(!rule)) { 3635 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3636 return -ENOENT; 3637 } 3638 3639 if (!selinux_initialized()) 3640 return 0; 3641 3642 rcu_read_lock(); 3643 3644 policy = rcu_dereference(state->policy); 3645 3646 if (rule->au_seqno < policy->latest_granting) { 3647 match = -ESTALE; 3648 goto out; 3649 } 3650 3651 ctxt = sidtab_search(policy->sidtab, sid); 3652 if (unlikely(!ctxt)) { 3653 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3654 sid); 3655 match = -ENOENT; 3656 goto out; 3657 } 3658 3659 /* a field/op pair that is not caught here will simply fall through 3660 without a match */ 3661 switch (field) { 3662 case AUDIT_SUBJ_USER: 3663 case AUDIT_OBJ_USER: 3664 switch (op) { 3665 case Audit_equal: 3666 match = (ctxt->user == rule->au_ctxt.user); 3667 break; 3668 case Audit_not_equal: 3669 match = (ctxt->user != rule->au_ctxt.user); 3670 break; 3671 } 3672 break; 3673 case AUDIT_SUBJ_ROLE: 3674 case AUDIT_OBJ_ROLE: 3675 switch (op) { 3676 case Audit_equal: 3677 match = (ctxt->role == rule->au_ctxt.role); 3678 break; 3679 case Audit_not_equal: 3680 match = (ctxt->role != rule->au_ctxt.role); 3681 break; 3682 } 3683 break; 3684 case AUDIT_SUBJ_TYPE: 3685 case AUDIT_OBJ_TYPE: 3686 switch (op) { 3687 case Audit_equal: 3688 match = (ctxt->type == rule->au_ctxt.type); 3689 break; 3690 case Audit_not_equal: 3691 match = (ctxt->type != rule->au_ctxt.type); 3692 break; 3693 } 3694 break; 3695 case AUDIT_SUBJ_SEN: 3696 case AUDIT_SUBJ_CLR: 3697 case AUDIT_OBJ_LEV_LOW: 3698 case AUDIT_OBJ_LEV_HIGH: 3699 level = ((field == AUDIT_SUBJ_SEN || 3700 field == AUDIT_OBJ_LEV_LOW) ? 3701 &ctxt->range.level[0] : &ctxt->range.level[1]); 3702 switch (op) { 3703 case Audit_equal: 3704 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3705 level); 3706 break; 3707 case Audit_not_equal: 3708 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3709 level); 3710 break; 3711 case Audit_lt: 3712 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3713 level) && 3714 !mls_level_eq(&rule->au_ctxt.range.level[0], 3715 level)); 3716 break; 3717 case Audit_le: 3718 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3719 level); 3720 break; 3721 case Audit_gt: 3722 match = (mls_level_dom(level, 3723 &rule->au_ctxt.range.level[0]) && 3724 !mls_level_eq(level, 3725 &rule->au_ctxt.range.level[0])); 3726 break; 3727 case Audit_ge: 3728 match = mls_level_dom(level, 3729 &rule->au_ctxt.range.level[0]); 3730 break; 3731 } 3732 } 3733 3734 out: 3735 rcu_read_unlock(); 3736 return match; 3737 } 3738 3739 static int aurule_avc_callback(u32 event) 3740 { 3741 if (event == AVC_CALLBACK_RESET) 3742 return audit_update_lsm_rules(); 3743 return 0; 3744 } 3745 3746 static int __init aurule_init(void) 3747 { 3748 int err; 3749 3750 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3751 if (err) 3752 panic("avc_add_callback() failed, error %d\n", err); 3753 3754 return err; 3755 } 3756 __initcall(aurule_init); 3757 3758 #ifdef CONFIG_NETLABEL 3759 /** 3760 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3761 * @secattr: the NetLabel packet security attributes 3762 * @sid: the SELinux SID 3763 * 3764 * Description: 3765 * Attempt to cache the context in @ctx, which was derived from the packet in 3766 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3767 * already been initialized. 3768 * 3769 */ 3770 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3771 u32 sid) 3772 { 3773 u32 *sid_cache; 3774 3775 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3776 if (sid_cache == NULL) 3777 return; 3778 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3779 if (secattr->cache == NULL) { 3780 kfree(sid_cache); 3781 return; 3782 } 3783 3784 *sid_cache = sid; 3785 secattr->cache->free = kfree; 3786 secattr->cache->data = sid_cache; 3787 secattr->flags |= NETLBL_SECATTR_CACHE; 3788 } 3789 3790 /** 3791 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3792 * @secattr: the NetLabel packet security attributes 3793 * @sid: the SELinux SID 3794 * 3795 * Description: 3796 * Convert the given NetLabel security attributes in @secattr into a 3797 * SELinux SID. If the @secattr field does not contain a full SELinux 3798 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3799 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3800 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3801 * conversion for future lookups. Returns zero on success, negative values on 3802 * failure. 3803 * 3804 */ 3805 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3806 u32 *sid) 3807 { 3808 struct selinux_policy *policy; 3809 struct policydb *policydb; 3810 struct sidtab *sidtab; 3811 int rc; 3812 struct context *ctx; 3813 struct context ctx_new; 3814 3815 if (!selinux_initialized()) { 3816 *sid = SECSID_NULL; 3817 return 0; 3818 } 3819 3820 retry: 3821 rc = 0; 3822 rcu_read_lock(); 3823 policy = rcu_dereference(selinux_state.policy); 3824 policydb = &policy->policydb; 3825 sidtab = policy->sidtab; 3826 3827 if (secattr->flags & NETLBL_SECATTR_CACHE) 3828 *sid = *(u32 *)secattr->cache->data; 3829 else if (secattr->flags & NETLBL_SECATTR_SECID) 3830 *sid = secattr->attr.secid; 3831 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3832 rc = -EIDRM; 3833 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3834 if (ctx == NULL) 3835 goto out; 3836 3837 context_init(&ctx_new); 3838 ctx_new.user = ctx->user; 3839 ctx_new.role = ctx->role; 3840 ctx_new.type = ctx->type; 3841 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3842 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3843 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3844 if (rc) 3845 goto out; 3846 } 3847 rc = -EIDRM; 3848 if (!mls_context_isvalid(policydb, &ctx_new)) { 3849 ebitmap_destroy(&ctx_new.range.level[0].cat); 3850 goto out; 3851 } 3852 3853 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3854 ebitmap_destroy(&ctx_new.range.level[0].cat); 3855 if (rc == -ESTALE) { 3856 rcu_read_unlock(); 3857 goto retry; 3858 } 3859 if (rc) 3860 goto out; 3861 3862 security_netlbl_cache_add(secattr, *sid); 3863 } else 3864 *sid = SECSID_NULL; 3865 3866 out: 3867 rcu_read_unlock(); 3868 return rc; 3869 } 3870 3871 /** 3872 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3873 * @sid: the SELinux SID 3874 * @secattr: the NetLabel packet security attributes 3875 * 3876 * Description: 3877 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3878 * Returns zero on success, negative values on failure. 3879 * 3880 */ 3881 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3882 { 3883 struct selinux_policy *policy; 3884 struct policydb *policydb; 3885 int rc; 3886 struct context *ctx; 3887 3888 if (!selinux_initialized()) 3889 return 0; 3890 3891 rcu_read_lock(); 3892 policy = rcu_dereference(selinux_state.policy); 3893 policydb = &policy->policydb; 3894 3895 rc = -ENOENT; 3896 ctx = sidtab_search(policy->sidtab, sid); 3897 if (ctx == NULL) 3898 goto out; 3899 3900 rc = -ENOMEM; 3901 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3902 GFP_ATOMIC); 3903 if (secattr->domain == NULL) 3904 goto out; 3905 3906 secattr->attr.secid = sid; 3907 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3908 mls_export_netlbl_lvl(policydb, ctx, secattr); 3909 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3910 out: 3911 rcu_read_unlock(); 3912 return rc; 3913 } 3914 #endif /* CONFIG_NETLABEL */ 3915 3916 /** 3917 * __security_read_policy - read the policy. 3918 * @policy: SELinux policy 3919 * @data: binary policy data 3920 * @len: length of data in bytes 3921 * 3922 */ 3923 static int __security_read_policy(struct selinux_policy *policy, 3924 void *data, size_t *len) 3925 { 3926 int rc; 3927 struct policy_file fp; 3928 3929 fp.data = data; 3930 fp.len = *len; 3931 3932 rc = policydb_write(&policy->policydb, &fp); 3933 if (rc) 3934 return rc; 3935 3936 *len = (unsigned long)fp.data - (unsigned long)data; 3937 return 0; 3938 } 3939 3940 /** 3941 * security_read_policy - read the policy. 3942 * @data: binary policy data 3943 * @len: length of data in bytes 3944 * 3945 */ 3946 int security_read_policy(void **data, size_t *len) 3947 { 3948 struct selinux_state *state = &selinux_state; 3949 struct selinux_policy *policy; 3950 3951 policy = rcu_dereference_protected( 3952 state->policy, lockdep_is_held(&state->policy_mutex)); 3953 if (!policy) 3954 return -EINVAL; 3955 3956 *len = policy->policydb.len; 3957 *data = vmalloc_user(*len); 3958 if (!*data) 3959 return -ENOMEM; 3960 3961 return __security_read_policy(policy, *data, len); 3962 } 3963 3964 /** 3965 * security_read_state_kernel - read the policy. 3966 * @data: binary policy data 3967 * @len: length of data in bytes 3968 * 3969 * Allocates kernel memory for reading SELinux policy. 3970 * This function is for internal use only and should not 3971 * be used for returning data to user space. 3972 * 3973 * This function must be called with policy_mutex held. 3974 */ 3975 int security_read_state_kernel(void **data, size_t *len) 3976 { 3977 int err; 3978 struct selinux_state *state = &selinux_state; 3979 struct selinux_policy *policy; 3980 3981 policy = rcu_dereference_protected( 3982 state->policy, lockdep_is_held(&state->policy_mutex)); 3983 if (!policy) 3984 return -EINVAL; 3985 3986 *len = policy->policydb.len; 3987 *data = vmalloc(*len); 3988 if (!*data) 3989 return -ENOMEM; 3990 3991 err = __security_read_policy(policy, *data, len); 3992 if (err) { 3993 vfree(*data); 3994 *data = NULL; 3995 *len = 0; 3996 } 3997 return err; 3998 } 3999