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 convert_context_args { 72 struct selinux_state *state; 73 struct policydb *oldp; 74 struct policydb *newp; 75 }; 76 77 struct selinux_policy_convert_data { 78 struct convert_context_args args; 79 struct sidtab_convert_params sidtab_params; 80 }; 81 82 /* Forward declaration. */ 83 static int context_struct_to_string(struct policydb *policydb, 84 struct context *context, 85 char **scontext, 86 u32 *scontext_len); 87 88 static int sidtab_entry_to_string(struct policydb *policydb, 89 struct sidtab *sidtab, 90 struct sidtab_entry *entry, 91 char **scontext, 92 u32 *scontext_len); 93 94 static void context_struct_compute_av(struct policydb *policydb, 95 struct context *scontext, 96 struct context *tcontext, 97 u16 tclass, 98 struct av_decision *avd, 99 struct extended_perms *xperms); 100 101 static int selinux_set_mapping(struct policydb *pol, 102 const struct security_class_mapping *map, 103 struct selinux_map *out_map) 104 { 105 u16 i, j; 106 unsigned k; 107 bool print_unknown_handle = false; 108 109 /* Find number of classes in the input mapping */ 110 if (!map) 111 return -EINVAL; 112 i = 0; 113 while (map[i].name) 114 i++; 115 116 /* Allocate space for the class records, plus one for class zero */ 117 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 118 if (!out_map->mapping) 119 return -ENOMEM; 120 121 /* Store the raw class and permission values */ 122 j = 0; 123 while (map[j].name) { 124 const struct security_class_mapping *p_in = map + (j++); 125 struct selinux_mapping *p_out = out_map->mapping + j; 126 127 /* An empty class string skips ahead */ 128 if (!strcmp(p_in->name, "")) { 129 p_out->num_perms = 0; 130 continue; 131 } 132 133 p_out->value = string_to_security_class(pol, p_in->name); 134 if (!p_out->value) { 135 pr_info("SELinux: Class %s not defined in policy.\n", 136 p_in->name); 137 if (pol->reject_unknown) 138 goto err; 139 p_out->num_perms = 0; 140 print_unknown_handle = true; 141 continue; 142 } 143 144 k = 0; 145 while (p_in->perms[k]) { 146 /* An empty permission string skips ahead */ 147 if (!*p_in->perms[k]) { 148 k++; 149 continue; 150 } 151 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 152 p_in->perms[k]); 153 if (!p_out->perms[k]) { 154 pr_info("SELinux: Permission %s in class %s not defined in policy.\n", 155 p_in->perms[k], p_in->name); 156 if (pol->reject_unknown) 157 goto err; 158 print_unknown_handle = true; 159 } 160 161 k++; 162 } 163 p_out->num_perms = k; 164 } 165 166 if (print_unknown_handle) 167 pr_info("SELinux: the above unknown classes and permissions will be %s\n", 168 pol->allow_unknown ? "allowed" : "denied"); 169 170 out_map->size = i; 171 return 0; 172 err: 173 kfree(out_map->mapping); 174 out_map->mapping = NULL; 175 return -EINVAL; 176 } 177 178 /* 179 * Get real, policy values from mapped values 180 */ 181 182 static u16 unmap_class(struct selinux_map *map, u16 tclass) 183 { 184 if (tclass < map->size) 185 return map->mapping[tclass].value; 186 187 return tclass; 188 } 189 190 /* 191 * Get kernel value for class from its policy value 192 */ 193 static u16 map_class(struct selinux_map *map, u16 pol_value) 194 { 195 u16 i; 196 197 for (i = 1; i < map->size; i++) { 198 if (map->mapping[i].value == pol_value) 199 return i; 200 } 201 202 return SECCLASS_NULL; 203 } 204 205 static void map_decision(struct selinux_map *map, 206 u16 tclass, struct av_decision *avd, 207 int allow_unknown) 208 { 209 if (tclass < map->size) { 210 struct selinux_mapping *mapping = &map->mapping[tclass]; 211 unsigned int i, n = mapping->num_perms; 212 u32 result; 213 214 for (i = 0, result = 0; i < n; i++) { 215 if (avd->allowed & mapping->perms[i]) 216 result |= 1<<i; 217 if (allow_unknown && !mapping->perms[i]) 218 result |= 1<<i; 219 } 220 avd->allowed = result; 221 222 for (i = 0, result = 0; i < n; i++) 223 if (avd->auditallow & mapping->perms[i]) 224 result |= 1<<i; 225 avd->auditallow = result; 226 227 for (i = 0, result = 0; i < n; i++) { 228 if (avd->auditdeny & mapping->perms[i]) 229 result |= 1<<i; 230 if (!allow_unknown && !mapping->perms[i]) 231 result |= 1<<i; 232 } 233 /* 234 * In case the kernel has a bug and requests a permission 235 * between num_perms and the maximum permission number, we 236 * should audit that denial 237 */ 238 for (; i < (sizeof(u32)*8); i++) 239 result |= 1<<i; 240 avd->auditdeny = result; 241 } 242 } 243 244 int security_mls_enabled(struct selinux_state *state) 245 { 246 int mls_enabled; 247 struct selinux_policy *policy; 248 249 if (!selinux_initialized(state)) 250 return 0; 251 252 rcu_read_lock(); 253 policy = rcu_dereference(state->policy); 254 mls_enabled = policy->policydb.mls_enabled; 255 rcu_read_unlock(); 256 return mls_enabled; 257 } 258 259 /* 260 * Return the boolean value of a constraint expression 261 * when it is applied to the specified source and target 262 * security contexts. 263 * 264 * xcontext is a special beast... It is used by the validatetrans rules 265 * only. For these rules, scontext is the context before the transition, 266 * tcontext is the context after the transition, and xcontext is the context 267 * of the process performing the transition. All other callers of 268 * constraint_expr_eval should pass in NULL for xcontext. 269 */ 270 static int constraint_expr_eval(struct policydb *policydb, 271 struct context *scontext, 272 struct context *tcontext, 273 struct context *xcontext, 274 struct constraint_expr *cexpr) 275 { 276 u32 val1, val2; 277 struct context *c; 278 struct role_datum *r1, *r2; 279 struct mls_level *l1, *l2; 280 struct constraint_expr *e; 281 int s[CEXPR_MAXDEPTH]; 282 int sp = -1; 283 284 for (e = cexpr; e; e = e->next) { 285 switch (e->expr_type) { 286 case CEXPR_NOT: 287 BUG_ON(sp < 0); 288 s[sp] = !s[sp]; 289 break; 290 case CEXPR_AND: 291 BUG_ON(sp < 1); 292 sp--; 293 s[sp] &= s[sp + 1]; 294 break; 295 case CEXPR_OR: 296 BUG_ON(sp < 1); 297 sp--; 298 s[sp] |= s[sp + 1]; 299 break; 300 case CEXPR_ATTR: 301 if (sp == (CEXPR_MAXDEPTH - 1)) 302 return 0; 303 switch (e->attr) { 304 case CEXPR_USER: 305 val1 = scontext->user; 306 val2 = tcontext->user; 307 break; 308 case CEXPR_TYPE: 309 val1 = scontext->type; 310 val2 = tcontext->type; 311 break; 312 case CEXPR_ROLE: 313 val1 = scontext->role; 314 val2 = tcontext->role; 315 r1 = policydb->role_val_to_struct[val1 - 1]; 316 r2 = policydb->role_val_to_struct[val2 - 1]; 317 switch (e->op) { 318 case CEXPR_DOM: 319 s[++sp] = ebitmap_get_bit(&r1->dominates, 320 val2 - 1); 321 continue; 322 case CEXPR_DOMBY: 323 s[++sp] = ebitmap_get_bit(&r2->dominates, 324 val1 - 1); 325 continue; 326 case CEXPR_INCOMP: 327 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 328 val2 - 1) && 329 !ebitmap_get_bit(&r2->dominates, 330 val1 - 1)); 331 continue; 332 default: 333 break; 334 } 335 break; 336 case CEXPR_L1L2: 337 l1 = &(scontext->range.level[0]); 338 l2 = &(tcontext->range.level[0]); 339 goto mls_ops; 340 case CEXPR_L1H2: 341 l1 = &(scontext->range.level[0]); 342 l2 = &(tcontext->range.level[1]); 343 goto mls_ops; 344 case CEXPR_H1L2: 345 l1 = &(scontext->range.level[1]); 346 l2 = &(tcontext->range.level[0]); 347 goto mls_ops; 348 case CEXPR_H1H2: 349 l1 = &(scontext->range.level[1]); 350 l2 = &(tcontext->range.level[1]); 351 goto mls_ops; 352 case CEXPR_L1H1: 353 l1 = &(scontext->range.level[0]); 354 l2 = &(scontext->range.level[1]); 355 goto mls_ops; 356 case CEXPR_L2H2: 357 l1 = &(tcontext->range.level[0]); 358 l2 = &(tcontext->range.level[1]); 359 goto mls_ops; 360 mls_ops: 361 switch (e->op) { 362 case CEXPR_EQ: 363 s[++sp] = mls_level_eq(l1, l2); 364 continue; 365 case CEXPR_NEQ: 366 s[++sp] = !mls_level_eq(l1, l2); 367 continue; 368 case CEXPR_DOM: 369 s[++sp] = mls_level_dom(l1, l2); 370 continue; 371 case CEXPR_DOMBY: 372 s[++sp] = mls_level_dom(l2, l1); 373 continue; 374 case CEXPR_INCOMP: 375 s[++sp] = mls_level_incomp(l2, l1); 376 continue; 377 default: 378 BUG(); 379 return 0; 380 } 381 break; 382 default: 383 BUG(); 384 return 0; 385 } 386 387 switch (e->op) { 388 case CEXPR_EQ: 389 s[++sp] = (val1 == val2); 390 break; 391 case CEXPR_NEQ: 392 s[++sp] = (val1 != val2); 393 break; 394 default: 395 BUG(); 396 return 0; 397 } 398 break; 399 case CEXPR_NAMES: 400 if (sp == (CEXPR_MAXDEPTH-1)) 401 return 0; 402 c = scontext; 403 if (e->attr & CEXPR_TARGET) 404 c = tcontext; 405 else if (e->attr & CEXPR_XTARGET) { 406 c = xcontext; 407 if (!c) { 408 BUG(); 409 return 0; 410 } 411 } 412 if (e->attr & CEXPR_USER) 413 val1 = c->user; 414 else if (e->attr & CEXPR_ROLE) 415 val1 = c->role; 416 else if (e->attr & CEXPR_TYPE) 417 val1 = c->type; 418 else { 419 BUG(); 420 return 0; 421 } 422 423 switch (e->op) { 424 case CEXPR_EQ: 425 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 426 break; 427 case CEXPR_NEQ: 428 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 429 break; 430 default: 431 BUG(); 432 return 0; 433 } 434 break; 435 default: 436 BUG(); 437 return 0; 438 } 439 } 440 441 BUG_ON(sp != 0); 442 return s[0]; 443 } 444 445 /* 446 * security_dump_masked_av - dumps masked permissions during 447 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 448 */ 449 static int dump_masked_av_helper(void *k, void *d, void *args) 450 { 451 struct perm_datum *pdatum = d; 452 char **permission_names = args; 453 454 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 455 456 permission_names[pdatum->value - 1] = (char *)k; 457 458 return 0; 459 } 460 461 static void security_dump_masked_av(struct policydb *policydb, 462 struct context *scontext, 463 struct context *tcontext, 464 u16 tclass, 465 u32 permissions, 466 const char *reason) 467 { 468 struct common_datum *common_dat; 469 struct class_datum *tclass_dat; 470 struct audit_buffer *ab; 471 char *tclass_name; 472 char *scontext_name = NULL; 473 char *tcontext_name = NULL; 474 char *permission_names[32]; 475 int index; 476 u32 length; 477 bool need_comma = false; 478 479 if (!permissions) 480 return; 481 482 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); 483 tclass_dat = policydb->class_val_to_struct[tclass - 1]; 484 common_dat = tclass_dat->comdatum; 485 486 /* init permission_names */ 487 if (common_dat && 488 hashtab_map(&common_dat->permissions.table, 489 dump_masked_av_helper, permission_names) < 0) 490 goto out; 491 492 if (hashtab_map(&tclass_dat->permissions.table, 493 dump_masked_av_helper, permission_names) < 0) 494 goto out; 495 496 /* get scontext/tcontext in text form */ 497 if (context_struct_to_string(policydb, scontext, 498 &scontext_name, &length) < 0) 499 goto out; 500 501 if (context_struct_to_string(policydb, tcontext, 502 &tcontext_name, &length) < 0) 503 goto out; 504 505 /* audit a message */ 506 ab = audit_log_start(audit_context(), 507 GFP_ATOMIC, AUDIT_SELINUX_ERR); 508 if (!ab) 509 goto out; 510 511 audit_log_format(ab, "op=security_compute_av reason=%s " 512 "scontext=%s tcontext=%s tclass=%s perms=", 513 reason, scontext_name, tcontext_name, tclass_name); 514 515 for (index = 0; index < 32; index++) { 516 u32 mask = (1 << index); 517 518 if ((mask & permissions) == 0) 519 continue; 520 521 audit_log_format(ab, "%s%s", 522 need_comma ? "," : "", 523 permission_names[index] 524 ? permission_names[index] : "????"); 525 need_comma = true; 526 } 527 audit_log_end(ab); 528 out: 529 /* release scontext/tcontext */ 530 kfree(tcontext_name); 531 kfree(scontext_name); 532 } 533 534 /* 535 * security_boundary_permission - drops violated permissions 536 * on boundary constraint. 537 */ 538 static void type_attribute_bounds_av(struct policydb *policydb, 539 struct context *scontext, 540 struct context *tcontext, 541 u16 tclass, 542 struct av_decision *avd) 543 { 544 struct context lo_scontext; 545 struct context lo_tcontext, *tcontextp = tcontext; 546 struct av_decision lo_avd; 547 struct type_datum *source; 548 struct type_datum *target; 549 u32 masked = 0; 550 551 source = policydb->type_val_to_struct[scontext->type - 1]; 552 BUG_ON(!source); 553 554 if (!source->bounds) 555 return; 556 557 target = policydb->type_val_to_struct[tcontext->type - 1]; 558 BUG_ON(!target); 559 560 memset(&lo_avd, 0, sizeof(lo_avd)); 561 562 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 563 lo_scontext.type = source->bounds; 564 565 if (target->bounds) { 566 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 567 lo_tcontext.type = target->bounds; 568 tcontextp = &lo_tcontext; 569 } 570 571 context_struct_compute_av(policydb, &lo_scontext, 572 tcontextp, 573 tclass, 574 &lo_avd, 575 NULL); 576 577 masked = ~lo_avd.allowed & avd->allowed; 578 579 if (likely(!masked)) 580 return; /* no masked permission */ 581 582 /* mask violated permissions */ 583 avd->allowed &= ~masked; 584 585 /* audit masked permissions */ 586 security_dump_masked_av(policydb, scontext, tcontext, 587 tclass, masked, "bounds"); 588 } 589 590 /* 591 * flag which drivers have permissions 592 * only looking for ioctl based extended permssions 593 */ 594 void services_compute_xperms_drivers( 595 struct extended_perms *xperms, 596 struct avtab_node *node) 597 { 598 unsigned int i; 599 600 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 601 /* if one or more driver has all permissions allowed */ 602 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 603 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 604 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 605 /* if allowing permissions within a driver */ 606 security_xperm_set(xperms->drivers.p, 607 node->datum.u.xperms->driver); 608 } 609 610 xperms->len = 1; 611 } 612 613 /* 614 * Compute access vectors and extended permissions based on a context 615 * structure pair for the permissions in a particular class. 616 */ 617 static void context_struct_compute_av(struct policydb *policydb, 618 struct context *scontext, 619 struct context *tcontext, 620 u16 tclass, 621 struct av_decision *avd, 622 struct extended_perms *xperms) 623 { 624 struct constraint_node *constraint; 625 struct role_allow *ra; 626 struct avtab_key avkey; 627 struct avtab_node *node; 628 struct class_datum *tclass_datum; 629 struct ebitmap *sattr, *tattr; 630 struct ebitmap_node *snode, *tnode; 631 unsigned int i, j; 632 633 avd->allowed = 0; 634 avd->auditallow = 0; 635 avd->auditdeny = 0xffffffff; 636 if (xperms) { 637 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 638 xperms->len = 0; 639 } 640 641 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 642 if (printk_ratelimit()) 643 pr_warn("SELinux: Invalid class %hu\n", tclass); 644 return; 645 } 646 647 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 648 649 /* 650 * If a specific type enforcement rule was defined for 651 * this permission check, then use it. 652 */ 653 avkey.target_class = tclass; 654 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 655 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 656 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 657 ebitmap_for_each_positive_bit(sattr, snode, i) { 658 ebitmap_for_each_positive_bit(tattr, tnode, j) { 659 avkey.source_type = i + 1; 660 avkey.target_type = j + 1; 661 for (node = avtab_search_node(&policydb->te_avtab, 662 &avkey); 663 node; 664 node = avtab_search_node_next(node, avkey.specified)) { 665 if (node->key.specified == AVTAB_ALLOWED) 666 avd->allowed |= node->datum.u.data; 667 else if (node->key.specified == AVTAB_AUDITALLOW) 668 avd->auditallow |= node->datum.u.data; 669 else if (node->key.specified == AVTAB_AUDITDENY) 670 avd->auditdeny &= node->datum.u.data; 671 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 672 services_compute_xperms_drivers(xperms, node); 673 } 674 675 /* Check conditional av table for additional permissions */ 676 cond_compute_av(&policydb->te_cond_avtab, &avkey, 677 avd, xperms); 678 679 } 680 } 681 682 /* 683 * Remove any permissions prohibited by a constraint (this includes 684 * the MLS policy). 685 */ 686 constraint = tclass_datum->constraints; 687 while (constraint) { 688 if ((constraint->permissions & (avd->allowed)) && 689 !constraint_expr_eval(policydb, scontext, tcontext, NULL, 690 constraint->expr)) { 691 avd->allowed &= ~(constraint->permissions); 692 } 693 constraint = constraint->next; 694 } 695 696 /* 697 * If checking process transition permission and the 698 * role is changing, then check the (current_role, new_role) 699 * pair. 700 */ 701 if (tclass == policydb->process_class && 702 (avd->allowed & policydb->process_trans_perms) && 703 scontext->role != tcontext->role) { 704 for (ra = policydb->role_allow; ra; ra = ra->next) { 705 if (scontext->role == ra->role && 706 tcontext->role == ra->new_role) 707 break; 708 } 709 if (!ra) 710 avd->allowed &= ~policydb->process_trans_perms; 711 } 712 713 /* 714 * If the given source and target types have boundary 715 * constraint, lazy checks have to mask any violated 716 * permission and notice it to userspace via audit. 717 */ 718 type_attribute_bounds_av(policydb, scontext, tcontext, 719 tclass, avd); 720 } 721 722 static int security_validtrans_handle_fail(struct selinux_state *state, 723 struct selinux_policy *policy, 724 struct sidtab_entry *oentry, 725 struct sidtab_entry *nentry, 726 struct sidtab_entry *tentry, 727 u16 tclass) 728 { 729 struct policydb *p = &policy->policydb; 730 struct sidtab *sidtab = policy->sidtab; 731 char *o = NULL, *n = NULL, *t = NULL; 732 u32 olen, nlen, tlen; 733 734 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) 735 goto out; 736 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) 737 goto out; 738 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) 739 goto out; 740 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 741 "op=security_validate_transition seresult=denied" 742 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 743 o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); 744 out: 745 kfree(o); 746 kfree(n); 747 kfree(t); 748 749 if (!enforcing_enabled(state)) 750 return 0; 751 return -EPERM; 752 } 753 754 static int security_compute_validatetrans(struct selinux_state *state, 755 u32 oldsid, u32 newsid, u32 tasksid, 756 u16 orig_tclass, bool user) 757 { 758 struct selinux_policy *policy; 759 struct policydb *policydb; 760 struct sidtab *sidtab; 761 struct sidtab_entry *oentry; 762 struct sidtab_entry *nentry; 763 struct sidtab_entry *tentry; 764 struct class_datum *tclass_datum; 765 struct constraint_node *constraint; 766 u16 tclass; 767 int rc = 0; 768 769 770 if (!selinux_initialized(state)) 771 return 0; 772 773 rcu_read_lock(); 774 775 policy = rcu_dereference(state->policy); 776 policydb = &policy->policydb; 777 sidtab = policy->sidtab; 778 779 if (!user) 780 tclass = unmap_class(&policy->map, orig_tclass); 781 else 782 tclass = orig_tclass; 783 784 if (!tclass || tclass > policydb->p_classes.nprim) { 785 rc = -EINVAL; 786 goto out; 787 } 788 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 789 790 oentry = sidtab_search_entry(sidtab, oldsid); 791 if (!oentry) { 792 pr_err("SELinux: %s: unrecognized SID %d\n", 793 __func__, oldsid); 794 rc = -EINVAL; 795 goto out; 796 } 797 798 nentry = sidtab_search_entry(sidtab, newsid); 799 if (!nentry) { 800 pr_err("SELinux: %s: unrecognized SID %d\n", 801 __func__, newsid); 802 rc = -EINVAL; 803 goto out; 804 } 805 806 tentry = sidtab_search_entry(sidtab, tasksid); 807 if (!tentry) { 808 pr_err("SELinux: %s: unrecognized SID %d\n", 809 __func__, tasksid); 810 rc = -EINVAL; 811 goto out; 812 } 813 814 constraint = tclass_datum->validatetrans; 815 while (constraint) { 816 if (!constraint_expr_eval(policydb, &oentry->context, 817 &nentry->context, &tentry->context, 818 constraint->expr)) { 819 if (user) 820 rc = -EPERM; 821 else 822 rc = security_validtrans_handle_fail(state, 823 policy, 824 oentry, 825 nentry, 826 tentry, 827 tclass); 828 goto out; 829 } 830 constraint = constraint->next; 831 } 832 833 out: 834 rcu_read_unlock(); 835 return rc; 836 } 837 838 int security_validate_transition_user(struct selinux_state *state, 839 u32 oldsid, u32 newsid, u32 tasksid, 840 u16 tclass) 841 { 842 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 843 tclass, true); 844 } 845 846 int security_validate_transition(struct selinux_state *state, 847 u32 oldsid, u32 newsid, u32 tasksid, 848 u16 orig_tclass) 849 { 850 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 851 orig_tclass, false); 852 } 853 854 /* 855 * security_bounded_transition - check whether the given 856 * transition is directed to bounded, or not. 857 * It returns 0, if @newsid is bounded by @oldsid. 858 * Otherwise, it returns error code. 859 * 860 * @state: SELinux state 861 * @oldsid : current security identifier 862 * @newsid : destinated security identifier 863 */ 864 int security_bounded_transition(struct selinux_state *state, 865 u32 old_sid, u32 new_sid) 866 { 867 struct selinux_policy *policy; 868 struct policydb *policydb; 869 struct sidtab *sidtab; 870 struct sidtab_entry *old_entry, *new_entry; 871 struct type_datum *type; 872 int index; 873 int rc; 874 875 if (!selinux_initialized(state)) 876 return 0; 877 878 rcu_read_lock(); 879 policy = rcu_dereference(state->policy); 880 policydb = &policy->policydb; 881 sidtab = policy->sidtab; 882 883 rc = -EINVAL; 884 old_entry = sidtab_search_entry(sidtab, old_sid); 885 if (!old_entry) { 886 pr_err("SELinux: %s: unrecognized SID %u\n", 887 __func__, old_sid); 888 goto out; 889 } 890 891 rc = -EINVAL; 892 new_entry = sidtab_search_entry(sidtab, new_sid); 893 if (!new_entry) { 894 pr_err("SELinux: %s: unrecognized SID %u\n", 895 __func__, new_sid); 896 goto out; 897 } 898 899 rc = 0; 900 /* type/domain unchanged */ 901 if (old_entry->context.type == new_entry->context.type) 902 goto out; 903 904 index = new_entry->context.type; 905 while (true) { 906 type = policydb->type_val_to_struct[index - 1]; 907 BUG_ON(!type); 908 909 /* not bounded anymore */ 910 rc = -EPERM; 911 if (!type->bounds) 912 break; 913 914 /* @newsid is bounded by @oldsid */ 915 rc = 0; 916 if (type->bounds == old_entry->context.type) 917 break; 918 919 index = type->bounds; 920 } 921 922 if (rc) { 923 char *old_name = NULL; 924 char *new_name = NULL; 925 u32 length; 926 927 if (!sidtab_entry_to_string(policydb, sidtab, old_entry, 928 &old_name, &length) && 929 !sidtab_entry_to_string(policydb, sidtab, new_entry, 930 &new_name, &length)) { 931 audit_log(audit_context(), 932 GFP_ATOMIC, AUDIT_SELINUX_ERR, 933 "op=security_bounded_transition " 934 "seresult=denied " 935 "oldcontext=%s newcontext=%s", 936 old_name, new_name); 937 } 938 kfree(new_name); 939 kfree(old_name); 940 } 941 out: 942 rcu_read_unlock(); 943 944 return rc; 945 } 946 947 static void avd_init(struct selinux_policy *policy, struct av_decision *avd) 948 { 949 avd->allowed = 0; 950 avd->auditallow = 0; 951 avd->auditdeny = 0xffffffff; 952 if (policy) 953 avd->seqno = policy->latest_granting; 954 else 955 avd->seqno = 0; 956 avd->flags = 0; 957 } 958 959 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 960 struct avtab_node *node) 961 { 962 unsigned int i; 963 964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 965 if (xpermd->driver != node->datum.u.xperms->driver) 966 return; 967 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 968 if (!security_xperm_test(node->datum.u.xperms->perms.p, 969 xpermd->driver)) 970 return; 971 } else { 972 BUG(); 973 } 974 975 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 976 xpermd->used |= XPERMS_ALLOWED; 977 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 978 memset(xpermd->allowed->p, 0xff, 979 sizeof(xpermd->allowed->p)); 980 } 981 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 982 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 983 xpermd->allowed->p[i] |= 984 node->datum.u.xperms->perms.p[i]; 985 } 986 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 987 xpermd->used |= XPERMS_AUDITALLOW; 988 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 989 memset(xpermd->auditallow->p, 0xff, 990 sizeof(xpermd->auditallow->p)); 991 } 992 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 993 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 994 xpermd->auditallow->p[i] |= 995 node->datum.u.xperms->perms.p[i]; 996 } 997 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 998 xpermd->used |= XPERMS_DONTAUDIT; 999 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 1000 memset(xpermd->dontaudit->p, 0xff, 1001 sizeof(xpermd->dontaudit->p)); 1002 } 1003 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 1004 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 1005 xpermd->dontaudit->p[i] |= 1006 node->datum.u.xperms->perms.p[i]; 1007 } 1008 } else { 1009 BUG(); 1010 } 1011 } 1012 1013 void security_compute_xperms_decision(struct selinux_state *state, 1014 u32 ssid, 1015 u32 tsid, 1016 u16 orig_tclass, 1017 u8 driver, 1018 struct extended_perms_decision *xpermd) 1019 { 1020 struct selinux_policy *policy; 1021 struct policydb *policydb; 1022 struct sidtab *sidtab; 1023 u16 tclass; 1024 struct context *scontext, *tcontext; 1025 struct avtab_key avkey; 1026 struct avtab_node *node; 1027 struct ebitmap *sattr, *tattr; 1028 struct ebitmap_node *snode, *tnode; 1029 unsigned int i, j; 1030 1031 xpermd->driver = driver; 1032 xpermd->used = 0; 1033 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1034 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1035 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1036 1037 rcu_read_lock(); 1038 if (!selinux_initialized(state)) 1039 goto allow; 1040 1041 policy = rcu_dereference(state->policy); 1042 policydb = &policy->policydb; 1043 sidtab = policy->sidtab; 1044 1045 scontext = sidtab_search(sidtab, ssid); 1046 if (!scontext) { 1047 pr_err("SELinux: %s: unrecognized SID %d\n", 1048 __func__, ssid); 1049 goto out; 1050 } 1051 1052 tcontext = sidtab_search(sidtab, tsid); 1053 if (!tcontext) { 1054 pr_err("SELinux: %s: unrecognized SID %d\n", 1055 __func__, tsid); 1056 goto out; 1057 } 1058 1059 tclass = unmap_class(&policy->map, orig_tclass); 1060 if (unlikely(orig_tclass && !tclass)) { 1061 if (policydb->allow_unknown) 1062 goto allow; 1063 goto out; 1064 } 1065 1066 1067 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1068 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1069 goto out; 1070 } 1071 1072 avkey.target_class = tclass; 1073 avkey.specified = AVTAB_XPERMS; 1074 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 1075 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 1076 ebitmap_for_each_positive_bit(sattr, snode, i) { 1077 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1078 avkey.source_type = i + 1; 1079 avkey.target_type = j + 1; 1080 for (node = avtab_search_node(&policydb->te_avtab, 1081 &avkey); 1082 node; 1083 node = avtab_search_node_next(node, avkey.specified)) 1084 services_compute_xperms_decision(xpermd, node); 1085 1086 cond_compute_xperms(&policydb->te_cond_avtab, 1087 &avkey, xpermd); 1088 } 1089 } 1090 out: 1091 rcu_read_unlock(); 1092 return; 1093 allow: 1094 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1095 goto out; 1096 } 1097 1098 /** 1099 * security_compute_av - Compute access vector decisions. 1100 * @state: SELinux state 1101 * @ssid: source security identifier 1102 * @tsid: target security identifier 1103 * @orig_tclass: target security class 1104 * @avd: access vector decisions 1105 * @xperms: extended permissions 1106 * 1107 * Compute a set of access vector decisions based on the 1108 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1109 */ 1110 void security_compute_av(struct selinux_state *state, 1111 u32 ssid, 1112 u32 tsid, 1113 u16 orig_tclass, 1114 struct av_decision *avd, 1115 struct extended_perms *xperms) 1116 { 1117 struct selinux_policy *policy; 1118 struct policydb *policydb; 1119 struct sidtab *sidtab; 1120 u16 tclass; 1121 struct context *scontext = NULL, *tcontext = NULL; 1122 1123 rcu_read_lock(); 1124 policy = rcu_dereference(state->policy); 1125 avd_init(policy, avd); 1126 xperms->len = 0; 1127 if (!selinux_initialized(state)) 1128 goto allow; 1129 1130 policydb = &policy->policydb; 1131 sidtab = policy->sidtab; 1132 1133 scontext = sidtab_search(sidtab, ssid); 1134 if (!scontext) { 1135 pr_err("SELinux: %s: unrecognized SID %d\n", 1136 __func__, ssid); 1137 goto out; 1138 } 1139 1140 /* permissive domain? */ 1141 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1142 avd->flags |= AVD_FLAGS_PERMISSIVE; 1143 1144 tcontext = sidtab_search(sidtab, tsid); 1145 if (!tcontext) { 1146 pr_err("SELinux: %s: unrecognized SID %d\n", 1147 __func__, tsid); 1148 goto out; 1149 } 1150 1151 tclass = unmap_class(&policy->map, orig_tclass); 1152 if (unlikely(orig_tclass && !tclass)) { 1153 if (policydb->allow_unknown) 1154 goto allow; 1155 goto out; 1156 } 1157 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1158 xperms); 1159 map_decision(&policy->map, orig_tclass, avd, 1160 policydb->allow_unknown); 1161 out: 1162 rcu_read_unlock(); 1163 return; 1164 allow: 1165 avd->allowed = 0xffffffff; 1166 goto out; 1167 } 1168 1169 void security_compute_av_user(struct selinux_state *state, 1170 u32 ssid, 1171 u32 tsid, 1172 u16 tclass, 1173 struct av_decision *avd) 1174 { 1175 struct selinux_policy *policy; 1176 struct policydb *policydb; 1177 struct sidtab *sidtab; 1178 struct context *scontext = NULL, *tcontext = NULL; 1179 1180 rcu_read_lock(); 1181 policy = rcu_dereference(state->policy); 1182 avd_init(policy, avd); 1183 if (!selinux_initialized(state)) 1184 goto allow; 1185 1186 policydb = &policy->policydb; 1187 sidtab = policy->sidtab; 1188 1189 scontext = sidtab_search(sidtab, ssid); 1190 if (!scontext) { 1191 pr_err("SELinux: %s: unrecognized SID %d\n", 1192 __func__, ssid); 1193 goto out; 1194 } 1195 1196 /* permissive domain? */ 1197 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1198 avd->flags |= AVD_FLAGS_PERMISSIVE; 1199 1200 tcontext = sidtab_search(sidtab, tsid); 1201 if (!tcontext) { 1202 pr_err("SELinux: %s: unrecognized SID %d\n", 1203 __func__, tsid); 1204 goto out; 1205 } 1206 1207 if (unlikely(!tclass)) { 1208 if (policydb->allow_unknown) 1209 goto allow; 1210 goto out; 1211 } 1212 1213 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1214 NULL); 1215 out: 1216 rcu_read_unlock(); 1217 return; 1218 allow: 1219 avd->allowed = 0xffffffff; 1220 goto out; 1221 } 1222 1223 /* 1224 * Write the security context string representation of 1225 * the context structure `context' into a dynamically 1226 * allocated string of the correct size. Set `*scontext' 1227 * to point to this string and set `*scontext_len' to 1228 * the length of the string. 1229 */ 1230 static int context_struct_to_string(struct policydb *p, 1231 struct context *context, 1232 char **scontext, u32 *scontext_len) 1233 { 1234 char *scontextp; 1235 1236 if (scontext) 1237 *scontext = NULL; 1238 *scontext_len = 0; 1239 1240 if (context->len) { 1241 *scontext_len = context->len; 1242 if (scontext) { 1243 *scontext = kstrdup(context->str, GFP_ATOMIC); 1244 if (!(*scontext)) 1245 return -ENOMEM; 1246 } 1247 return 0; 1248 } 1249 1250 /* Compute the size of the context. */ 1251 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1252 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1253 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1254 *scontext_len += mls_compute_context_len(p, context); 1255 1256 if (!scontext) 1257 return 0; 1258 1259 /* Allocate space for the context; caller must free this space. */ 1260 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1261 if (!scontextp) 1262 return -ENOMEM; 1263 *scontext = scontextp; 1264 1265 /* 1266 * Copy the user name, role name and type name into the context. 1267 */ 1268 scontextp += sprintf(scontextp, "%s:%s:%s", 1269 sym_name(p, SYM_USERS, context->user - 1), 1270 sym_name(p, SYM_ROLES, context->role - 1), 1271 sym_name(p, SYM_TYPES, context->type - 1)); 1272 1273 mls_sid_to_context(p, context, &scontextp); 1274 1275 *scontextp = 0; 1276 1277 return 0; 1278 } 1279 1280 static int sidtab_entry_to_string(struct policydb *p, 1281 struct sidtab *sidtab, 1282 struct sidtab_entry *entry, 1283 char **scontext, u32 *scontext_len) 1284 { 1285 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); 1286 1287 if (rc != -ENOENT) 1288 return rc; 1289 1290 rc = context_struct_to_string(p, &entry->context, scontext, 1291 scontext_len); 1292 if (!rc && scontext) 1293 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); 1294 return rc; 1295 } 1296 1297 #include "initial_sid_to_string.h" 1298 1299 int security_sidtab_hash_stats(struct selinux_state *state, char *page) 1300 { 1301 struct selinux_policy *policy; 1302 int rc; 1303 1304 if (!selinux_initialized(state)) { 1305 pr_err("SELinux: %s: called before initial load_policy\n", 1306 __func__); 1307 return -EINVAL; 1308 } 1309 1310 rcu_read_lock(); 1311 policy = rcu_dereference(state->policy); 1312 rc = sidtab_hash_stats(policy->sidtab, page); 1313 rcu_read_unlock(); 1314 1315 return rc; 1316 } 1317 1318 const char *security_get_initial_sid_context(u32 sid) 1319 { 1320 if (unlikely(sid > SECINITSID_NUM)) 1321 return NULL; 1322 return initial_sid_to_string[sid]; 1323 } 1324 1325 static int security_sid_to_context_core(struct selinux_state *state, 1326 u32 sid, char **scontext, 1327 u32 *scontext_len, int force, 1328 int only_invalid) 1329 { 1330 struct selinux_policy *policy; 1331 struct policydb *policydb; 1332 struct sidtab *sidtab; 1333 struct sidtab_entry *entry; 1334 int rc = 0; 1335 1336 if (scontext) 1337 *scontext = NULL; 1338 *scontext_len = 0; 1339 1340 if (!selinux_initialized(state)) { 1341 if (sid <= SECINITSID_NUM) { 1342 char *scontextp; 1343 const char *s = initial_sid_to_string[sid]; 1344 1345 if (!s) 1346 return -EINVAL; 1347 *scontext_len = strlen(s) + 1; 1348 if (!scontext) 1349 return 0; 1350 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1351 if (!scontextp) 1352 return -ENOMEM; 1353 *scontext = scontextp; 1354 return 0; 1355 } 1356 pr_err("SELinux: %s: called before initial " 1357 "load_policy on unknown SID %d\n", __func__, sid); 1358 return -EINVAL; 1359 } 1360 rcu_read_lock(); 1361 policy = rcu_dereference(state->policy); 1362 policydb = &policy->policydb; 1363 sidtab = policy->sidtab; 1364 1365 if (force) 1366 entry = sidtab_search_entry_force(sidtab, sid); 1367 else 1368 entry = sidtab_search_entry(sidtab, sid); 1369 if (!entry) { 1370 pr_err("SELinux: %s: unrecognized SID %d\n", 1371 __func__, sid); 1372 rc = -EINVAL; 1373 goto out_unlock; 1374 } 1375 if (only_invalid && !entry->context.len) 1376 goto out_unlock; 1377 1378 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1379 scontext_len); 1380 1381 out_unlock: 1382 rcu_read_unlock(); 1383 return rc; 1384 1385 } 1386 1387 /** 1388 * security_sid_to_context - Obtain a context for a given SID. 1389 * @state: SELinux state 1390 * @sid: security identifier, SID 1391 * @scontext: security context 1392 * @scontext_len: length in bytes 1393 * 1394 * Write the string representation of the context associated with @sid 1395 * into a dynamically allocated string of the correct size. Set @scontext 1396 * to point to this string and set @scontext_len to the length of the string. 1397 */ 1398 int security_sid_to_context(struct selinux_state *state, 1399 u32 sid, char **scontext, u32 *scontext_len) 1400 { 1401 return security_sid_to_context_core(state, sid, scontext, 1402 scontext_len, 0, 0); 1403 } 1404 1405 int security_sid_to_context_force(struct selinux_state *state, u32 sid, 1406 char **scontext, u32 *scontext_len) 1407 { 1408 return security_sid_to_context_core(state, sid, scontext, 1409 scontext_len, 1, 0); 1410 } 1411 1412 /** 1413 * security_sid_to_context_inval - Obtain a context for a given SID if it 1414 * is invalid. 1415 * @state: SELinux state 1416 * @sid: security identifier, SID 1417 * @scontext: security context 1418 * @scontext_len: length in bytes 1419 * 1420 * Write the string representation of the context associated with @sid 1421 * into a dynamically allocated string of the correct size, but only if the 1422 * context is invalid in the current policy. Set @scontext to point to 1423 * this string (or NULL if the context is valid) and set @scontext_len to 1424 * the length of the string (or 0 if the context is valid). 1425 */ 1426 int security_sid_to_context_inval(struct selinux_state *state, u32 sid, 1427 char **scontext, u32 *scontext_len) 1428 { 1429 return security_sid_to_context_core(state, sid, scontext, 1430 scontext_len, 1, 1); 1431 } 1432 1433 /* 1434 * Caveat: Mutates scontext. 1435 */ 1436 static int string_to_context_struct(struct policydb *pol, 1437 struct sidtab *sidtabp, 1438 char *scontext, 1439 struct context *ctx, 1440 u32 def_sid) 1441 { 1442 struct role_datum *role; 1443 struct type_datum *typdatum; 1444 struct user_datum *usrdatum; 1445 char *scontextp, *p, oldc; 1446 int rc = 0; 1447 1448 context_init(ctx); 1449 1450 /* Parse the security context. */ 1451 1452 rc = -EINVAL; 1453 scontextp = scontext; 1454 1455 /* Extract the user. */ 1456 p = scontextp; 1457 while (*p && *p != ':') 1458 p++; 1459 1460 if (*p == 0) 1461 goto out; 1462 1463 *p++ = 0; 1464 1465 usrdatum = symtab_search(&pol->p_users, scontextp); 1466 if (!usrdatum) 1467 goto out; 1468 1469 ctx->user = usrdatum->value; 1470 1471 /* Extract role. */ 1472 scontextp = p; 1473 while (*p && *p != ':') 1474 p++; 1475 1476 if (*p == 0) 1477 goto out; 1478 1479 *p++ = 0; 1480 1481 role = symtab_search(&pol->p_roles, scontextp); 1482 if (!role) 1483 goto out; 1484 ctx->role = role->value; 1485 1486 /* Extract type. */ 1487 scontextp = p; 1488 while (*p && *p != ':') 1489 p++; 1490 oldc = *p; 1491 *p++ = 0; 1492 1493 typdatum = symtab_search(&pol->p_types, scontextp); 1494 if (!typdatum || typdatum->attribute) 1495 goto out; 1496 1497 ctx->type = typdatum->value; 1498 1499 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1500 if (rc) 1501 goto out; 1502 1503 /* Check the validity of the new context. */ 1504 rc = -EINVAL; 1505 if (!policydb_context_isvalid(pol, ctx)) 1506 goto out; 1507 rc = 0; 1508 out: 1509 if (rc) 1510 context_destroy(ctx); 1511 return rc; 1512 } 1513 1514 static int security_context_to_sid_core(struct selinux_state *state, 1515 const char *scontext, u32 scontext_len, 1516 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1517 int force) 1518 { 1519 struct selinux_policy *policy; 1520 struct policydb *policydb; 1521 struct sidtab *sidtab; 1522 char *scontext2, *str = NULL; 1523 struct context context; 1524 int rc = 0; 1525 1526 /* An empty security context is never valid. */ 1527 if (!scontext_len) 1528 return -EINVAL; 1529 1530 /* Copy the string to allow changes and ensure a NUL terminator */ 1531 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1532 if (!scontext2) 1533 return -ENOMEM; 1534 1535 if (!selinux_initialized(state)) { 1536 int i; 1537 1538 for (i = 1; i < SECINITSID_NUM; i++) { 1539 const char *s = initial_sid_to_string[i]; 1540 1541 if (s && !strcmp(s, scontext2)) { 1542 *sid = i; 1543 goto out; 1544 } 1545 } 1546 *sid = SECINITSID_KERNEL; 1547 goto out; 1548 } 1549 *sid = SECSID_NULL; 1550 1551 if (force) { 1552 /* Save another copy for storing in uninterpreted form */ 1553 rc = -ENOMEM; 1554 str = kstrdup(scontext2, gfp_flags); 1555 if (!str) 1556 goto out; 1557 } 1558 retry: 1559 rcu_read_lock(); 1560 policy = rcu_dereference(state->policy); 1561 policydb = &policy->policydb; 1562 sidtab = policy->sidtab; 1563 rc = string_to_context_struct(policydb, sidtab, scontext2, 1564 &context, def_sid); 1565 if (rc == -EINVAL && force) { 1566 context.str = str; 1567 context.len = strlen(str) + 1; 1568 str = NULL; 1569 } else if (rc) 1570 goto out_unlock; 1571 rc = sidtab_context_to_sid(sidtab, &context, sid); 1572 if (rc == -ESTALE) { 1573 rcu_read_unlock(); 1574 if (context.str) { 1575 str = context.str; 1576 context.str = NULL; 1577 } 1578 context_destroy(&context); 1579 goto retry; 1580 } 1581 context_destroy(&context); 1582 out_unlock: 1583 rcu_read_unlock(); 1584 out: 1585 kfree(scontext2); 1586 kfree(str); 1587 return rc; 1588 } 1589 1590 /** 1591 * security_context_to_sid - Obtain a SID for a given security context. 1592 * @state: SELinux state 1593 * @scontext: security context 1594 * @scontext_len: length in bytes 1595 * @sid: security identifier, SID 1596 * @gfp: context for the allocation 1597 * 1598 * Obtains a SID associated with the security context that 1599 * has the string representation specified by @scontext. 1600 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1601 * memory is available, or 0 on success. 1602 */ 1603 int security_context_to_sid(struct selinux_state *state, 1604 const char *scontext, u32 scontext_len, u32 *sid, 1605 gfp_t gfp) 1606 { 1607 return security_context_to_sid_core(state, scontext, scontext_len, 1608 sid, SECSID_NULL, gfp, 0); 1609 } 1610 1611 int security_context_str_to_sid(struct selinux_state *state, 1612 const char *scontext, u32 *sid, gfp_t gfp) 1613 { 1614 return security_context_to_sid(state, scontext, strlen(scontext), 1615 sid, gfp); 1616 } 1617 1618 /** 1619 * security_context_to_sid_default - Obtain a SID for a given security context, 1620 * falling back to specified default if needed. 1621 * 1622 * @state: SELinux state 1623 * @scontext: security context 1624 * @scontext_len: length in bytes 1625 * @sid: security identifier, SID 1626 * @def_sid: default SID to assign on error 1627 * @gfp_flags: the allocator get-free-page (GFP) flags 1628 * 1629 * Obtains a SID associated with the security context that 1630 * has the string representation specified by @scontext. 1631 * The default SID is passed to the MLS layer to be used to allow 1632 * kernel labeling of the MLS field if the MLS field is not present 1633 * (for upgrading to MLS without full relabel). 1634 * Implicitly forces adding of the context even if it cannot be mapped yet. 1635 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1636 * memory is available, or 0 on success. 1637 */ 1638 int security_context_to_sid_default(struct selinux_state *state, 1639 const char *scontext, u32 scontext_len, 1640 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1641 { 1642 return security_context_to_sid_core(state, scontext, scontext_len, 1643 sid, def_sid, gfp_flags, 1); 1644 } 1645 1646 int security_context_to_sid_force(struct selinux_state *state, 1647 const char *scontext, u32 scontext_len, 1648 u32 *sid) 1649 { 1650 return security_context_to_sid_core(state, scontext, scontext_len, 1651 sid, SECSID_NULL, GFP_KERNEL, 1); 1652 } 1653 1654 static int compute_sid_handle_invalid_context( 1655 struct selinux_state *state, 1656 struct selinux_policy *policy, 1657 struct sidtab_entry *sentry, 1658 struct sidtab_entry *tentry, 1659 u16 tclass, 1660 struct context *newcontext) 1661 { 1662 struct policydb *policydb = &policy->policydb; 1663 struct sidtab *sidtab = policy->sidtab; 1664 char *s = NULL, *t = NULL, *n = NULL; 1665 u32 slen, tlen, nlen; 1666 struct audit_buffer *ab; 1667 1668 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) 1669 goto out; 1670 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) 1671 goto out; 1672 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1673 goto out; 1674 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); 1675 if (!ab) 1676 goto out; 1677 audit_log_format(ab, 1678 "op=security_compute_sid invalid_context="); 1679 /* no need to record the NUL with untrusted strings */ 1680 audit_log_n_untrustedstring(ab, n, nlen - 1); 1681 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1682 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1683 audit_log_end(ab); 1684 out: 1685 kfree(s); 1686 kfree(t); 1687 kfree(n); 1688 if (!enforcing_enabled(state)) 1689 return 0; 1690 return -EACCES; 1691 } 1692 1693 static void filename_compute_type(struct policydb *policydb, 1694 struct context *newcontext, 1695 u32 stype, u32 ttype, u16 tclass, 1696 const char *objname) 1697 { 1698 struct filename_trans_key ft; 1699 struct filename_trans_datum *datum; 1700 1701 /* 1702 * Most filename trans rules are going to live in specific directories 1703 * like /dev or /var/run. This bitmap will quickly skip rule searches 1704 * if the ttype does not contain any rules. 1705 */ 1706 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1707 return; 1708 1709 ft.ttype = ttype; 1710 ft.tclass = tclass; 1711 ft.name = objname; 1712 1713 datum = policydb_filenametr_search(policydb, &ft); 1714 while (datum) { 1715 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1716 newcontext->type = datum->otype; 1717 return; 1718 } 1719 datum = datum->next; 1720 } 1721 } 1722 1723 static int security_compute_sid(struct selinux_state *state, 1724 u32 ssid, 1725 u32 tsid, 1726 u16 orig_tclass, 1727 u32 specified, 1728 const char *objname, 1729 u32 *out_sid, 1730 bool kern) 1731 { 1732 struct selinux_policy *policy; 1733 struct policydb *policydb; 1734 struct sidtab *sidtab; 1735 struct class_datum *cladatum; 1736 struct context *scontext, *tcontext, newcontext; 1737 struct sidtab_entry *sentry, *tentry; 1738 struct avtab_key avkey; 1739 struct avtab_datum *avdatum; 1740 struct avtab_node *node; 1741 u16 tclass; 1742 int rc = 0; 1743 bool sock; 1744 1745 if (!selinux_initialized(state)) { 1746 switch (orig_tclass) { 1747 case SECCLASS_PROCESS: /* kernel value */ 1748 *out_sid = ssid; 1749 break; 1750 default: 1751 *out_sid = tsid; 1752 break; 1753 } 1754 goto out; 1755 } 1756 1757 retry: 1758 cladatum = NULL; 1759 context_init(&newcontext); 1760 1761 rcu_read_lock(); 1762 1763 policy = rcu_dereference(state->policy); 1764 1765 if (kern) { 1766 tclass = unmap_class(&policy->map, orig_tclass); 1767 sock = security_is_socket_class(orig_tclass); 1768 } else { 1769 tclass = orig_tclass; 1770 sock = security_is_socket_class(map_class(&policy->map, 1771 tclass)); 1772 } 1773 1774 policydb = &policy->policydb; 1775 sidtab = policy->sidtab; 1776 1777 sentry = sidtab_search_entry(sidtab, ssid); 1778 if (!sentry) { 1779 pr_err("SELinux: %s: unrecognized SID %d\n", 1780 __func__, ssid); 1781 rc = -EINVAL; 1782 goto out_unlock; 1783 } 1784 tentry = sidtab_search_entry(sidtab, tsid); 1785 if (!tentry) { 1786 pr_err("SELinux: %s: unrecognized SID %d\n", 1787 __func__, tsid); 1788 rc = -EINVAL; 1789 goto out_unlock; 1790 } 1791 1792 scontext = &sentry->context; 1793 tcontext = &tentry->context; 1794 1795 if (tclass && tclass <= policydb->p_classes.nprim) 1796 cladatum = policydb->class_val_to_struct[tclass - 1]; 1797 1798 /* Set the user identity. */ 1799 switch (specified) { 1800 case AVTAB_TRANSITION: 1801 case AVTAB_CHANGE: 1802 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1803 newcontext.user = tcontext->user; 1804 } else { 1805 /* notice this gets both DEFAULT_SOURCE and unset */ 1806 /* Use the process user identity. */ 1807 newcontext.user = scontext->user; 1808 } 1809 break; 1810 case AVTAB_MEMBER: 1811 /* Use the related object owner. */ 1812 newcontext.user = tcontext->user; 1813 break; 1814 } 1815 1816 /* Set the role to default values. */ 1817 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1818 newcontext.role = scontext->role; 1819 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1820 newcontext.role = tcontext->role; 1821 } else { 1822 if ((tclass == policydb->process_class) || sock) 1823 newcontext.role = scontext->role; 1824 else 1825 newcontext.role = OBJECT_R_VAL; 1826 } 1827 1828 /* Set the type to default values. */ 1829 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1830 newcontext.type = scontext->type; 1831 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1832 newcontext.type = tcontext->type; 1833 } else { 1834 if ((tclass == policydb->process_class) || sock) { 1835 /* Use the type of process. */ 1836 newcontext.type = scontext->type; 1837 } else { 1838 /* Use the type of the related object. */ 1839 newcontext.type = tcontext->type; 1840 } 1841 } 1842 1843 /* Look for a type transition/member/change rule. */ 1844 avkey.source_type = scontext->type; 1845 avkey.target_type = tcontext->type; 1846 avkey.target_class = tclass; 1847 avkey.specified = specified; 1848 avdatum = avtab_search(&policydb->te_avtab, &avkey); 1849 1850 /* If no permanent rule, also check for enabled conditional rules */ 1851 if (!avdatum) { 1852 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1853 for (; node; node = avtab_search_node_next(node, specified)) { 1854 if (node->key.specified & AVTAB_ENABLED) { 1855 avdatum = &node->datum; 1856 break; 1857 } 1858 } 1859 } 1860 1861 if (avdatum) { 1862 /* Use the type from the type transition/member/change rule. */ 1863 newcontext.type = avdatum->u.data; 1864 } 1865 1866 /* if we have a objname this is a file trans check so check those rules */ 1867 if (objname) 1868 filename_compute_type(policydb, &newcontext, scontext->type, 1869 tcontext->type, tclass, objname); 1870 1871 /* Check for class-specific changes. */ 1872 if (specified & AVTAB_TRANSITION) { 1873 /* Look for a role transition rule. */ 1874 struct role_trans_datum *rtd; 1875 struct role_trans_key rtk = { 1876 .role = scontext->role, 1877 .type = tcontext->type, 1878 .tclass = tclass, 1879 }; 1880 1881 rtd = policydb_roletr_search(policydb, &rtk); 1882 if (rtd) 1883 newcontext.role = rtd->new_role; 1884 } 1885 1886 /* Set the MLS attributes. 1887 This is done last because it may allocate memory. */ 1888 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1889 &newcontext, sock); 1890 if (rc) 1891 goto out_unlock; 1892 1893 /* Check the validity of the context. */ 1894 if (!policydb_context_isvalid(policydb, &newcontext)) { 1895 rc = compute_sid_handle_invalid_context(state, policy, sentry, 1896 tentry, tclass, 1897 &newcontext); 1898 if (rc) 1899 goto out_unlock; 1900 } 1901 /* Obtain the sid for the context. */ 1902 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1903 if (rc == -ESTALE) { 1904 rcu_read_unlock(); 1905 context_destroy(&newcontext); 1906 goto retry; 1907 } 1908 out_unlock: 1909 rcu_read_unlock(); 1910 context_destroy(&newcontext); 1911 out: 1912 return rc; 1913 } 1914 1915 /** 1916 * security_transition_sid - Compute the SID for a new subject/object. 1917 * @state: SELinux state 1918 * @ssid: source security identifier 1919 * @tsid: target security identifier 1920 * @tclass: target security class 1921 * @qstr: object name 1922 * @out_sid: security identifier for new subject/object 1923 * 1924 * Compute a SID to use for labeling a new subject or object in the 1925 * class @tclass based on a SID pair (@ssid, @tsid). 1926 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1927 * if insufficient memory is available, or %0 if the new SID was 1928 * computed successfully. 1929 */ 1930 int security_transition_sid(struct selinux_state *state, 1931 u32 ssid, u32 tsid, u16 tclass, 1932 const struct qstr *qstr, u32 *out_sid) 1933 { 1934 return security_compute_sid(state, ssid, tsid, tclass, 1935 AVTAB_TRANSITION, 1936 qstr ? qstr->name : NULL, out_sid, true); 1937 } 1938 1939 int security_transition_sid_user(struct selinux_state *state, 1940 u32 ssid, u32 tsid, u16 tclass, 1941 const char *objname, u32 *out_sid) 1942 { 1943 return security_compute_sid(state, ssid, tsid, tclass, 1944 AVTAB_TRANSITION, 1945 objname, out_sid, false); 1946 } 1947 1948 /** 1949 * security_member_sid - Compute the SID for member selection. 1950 * @state: SELinux state 1951 * @ssid: source security identifier 1952 * @tsid: target security identifier 1953 * @tclass: target security class 1954 * @out_sid: security identifier for selected member 1955 * 1956 * Compute a SID to use when selecting a member of a polyinstantiated 1957 * object of class @tclass based on a SID pair (@ssid, @tsid). 1958 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1959 * if insufficient memory is available, or %0 if the SID was 1960 * computed successfully. 1961 */ 1962 int security_member_sid(struct selinux_state *state, 1963 u32 ssid, 1964 u32 tsid, 1965 u16 tclass, 1966 u32 *out_sid) 1967 { 1968 return security_compute_sid(state, ssid, tsid, tclass, 1969 AVTAB_MEMBER, NULL, 1970 out_sid, false); 1971 } 1972 1973 /** 1974 * security_change_sid - Compute the SID for object relabeling. 1975 * @state: SELinux state 1976 * @ssid: source security identifier 1977 * @tsid: target security identifier 1978 * @tclass: target security class 1979 * @out_sid: security identifier for selected member 1980 * 1981 * Compute a SID to use for relabeling an object of class @tclass 1982 * based on a SID pair (@ssid, @tsid). 1983 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1984 * if insufficient memory is available, or %0 if the SID was 1985 * computed successfully. 1986 */ 1987 int security_change_sid(struct selinux_state *state, 1988 u32 ssid, 1989 u32 tsid, 1990 u16 tclass, 1991 u32 *out_sid) 1992 { 1993 return security_compute_sid(state, 1994 ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1995 out_sid, false); 1996 } 1997 1998 static inline int convert_context_handle_invalid_context( 1999 struct selinux_state *state, 2000 struct policydb *policydb, 2001 struct context *context) 2002 { 2003 char *s; 2004 u32 len; 2005 2006 if (enforcing_enabled(state)) 2007 return -EINVAL; 2008 2009 if (!context_struct_to_string(policydb, context, &s, &len)) { 2010 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 2011 s); 2012 kfree(s); 2013 } 2014 return 0; 2015 } 2016 2017 /* 2018 * Convert the values in the security context 2019 * structure `oldc' from the values specified 2020 * in the policy `p->oldp' to the values specified 2021 * in the policy `p->newp', storing the new context 2022 * in `newc'. Verify that the context is valid 2023 * under the new policy. 2024 */ 2025 static int convert_context(struct context *oldc, struct context *newc, void *p) 2026 { 2027 struct convert_context_args *args; 2028 struct ocontext *oc; 2029 struct role_datum *role; 2030 struct type_datum *typdatum; 2031 struct user_datum *usrdatum; 2032 char *s; 2033 u32 len; 2034 int rc; 2035 2036 args = p; 2037 2038 if (oldc->str) { 2039 s = kstrdup(oldc->str, GFP_KERNEL); 2040 if (!s) 2041 return -ENOMEM; 2042 2043 rc = string_to_context_struct(args->newp, NULL, s, 2044 newc, SECSID_NULL); 2045 if (rc == -EINVAL) { 2046 /* 2047 * Retain string representation for later mapping. 2048 * 2049 * IMPORTANT: We need to copy the contents of oldc->str 2050 * back into s again because string_to_context_struct() 2051 * may have garbled it. 2052 */ 2053 memcpy(s, oldc->str, oldc->len); 2054 context_init(newc); 2055 newc->str = s; 2056 newc->len = oldc->len; 2057 return 0; 2058 } 2059 kfree(s); 2060 if (rc) { 2061 /* Other error condition, e.g. ENOMEM. */ 2062 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2063 oldc->str, -rc); 2064 return rc; 2065 } 2066 pr_info("SELinux: Context %s became valid (mapped).\n", 2067 oldc->str); 2068 return 0; 2069 } 2070 2071 context_init(newc); 2072 2073 /* Convert the user. */ 2074 usrdatum = symtab_search(&args->newp->p_users, 2075 sym_name(args->oldp, 2076 SYM_USERS, oldc->user - 1)); 2077 if (!usrdatum) 2078 goto bad; 2079 newc->user = usrdatum->value; 2080 2081 /* Convert the role. */ 2082 role = symtab_search(&args->newp->p_roles, 2083 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2084 if (!role) 2085 goto bad; 2086 newc->role = role->value; 2087 2088 /* Convert the type. */ 2089 typdatum = symtab_search(&args->newp->p_types, 2090 sym_name(args->oldp, 2091 SYM_TYPES, oldc->type - 1)); 2092 if (!typdatum) 2093 goto bad; 2094 newc->type = typdatum->value; 2095 2096 /* Convert the MLS fields if dealing with MLS policies */ 2097 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2098 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2099 if (rc) 2100 goto bad; 2101 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2102 /* 2103 * Switching between non-MLS and MLS policy: 2104 * ensure that the MLS fields of the context for all 2105 * existing entries in the sidtab are filled in with a 2106 * suitable default value, likely taken from one of the 2107 * initial SIDs. 2108 */ 2109 oc = args->newp->ocontexts[OCON_ISID]; 2110 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2111 oc = oc->next; 2112 if (!oc) { 2113 pr_err("SELinux: unable to look up" 2114 " the initial SIDs list\n"); 2115 goto bad; 2116 } 2117 rc = mls_range_set(newc, &oc->context[0].range); 2118 if (rc) 2119 goto bad; 2120 } 2121 2122 /* Check the validity of the new context. */ 2123 if (!policydb_context_isvalid(args->newp, newc)) { 2124 rc = convert_context_handle_invalid_context(args->state, 2125 args->oldp, 2126 oldc); 2127 if (rc) 2128 goto bad; 2129 } 2130 2131 return 0; 2132 bad: 2133 /* Map old representation to string and save it. */ 2134 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2135 if (rc) 2136 return rc; 2137 context_destroy(newc); 2138 newc->str = s; 2139 newc->len = len; 2140 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2141 newc->str); 2142 return 0; 2143 } 2144 2145 static void security_load_policycaps(struct selinux_state *state, 2146 struct selinux_policy *policy) 2147 { 2148 struct policydb *p; 2149 unsigned int i; 2150 struct ebitmap_node *node; 2151 2152 p = &policy->policydb; 2153 2154 for (i = 0; i < ARRAY_SIZE(state->policycap); i++) 2155 WRITE_ONCE(state->policycap[i], 2156 ebitmap_get_bit(&p->policycaps, i)); 2157 2158 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2159 pr_info("SELinux: policy capability %s=%d\n", 2160 selinux_policycap_names[i], 2161 ebitmap_get_bit(&p->policycaps, i)); 2162 2163 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2164 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2165 pr_info("SELinux: unknown policy capability %u\n", 2166 i); 2167 } 2168 } 2169 2170 static int security_preserve_bools(struct selinux_policy *oldpolicy, 2171 struct selinux_policy *newpolicy); 2172 2173 static void selinux_policy_free(struct selinux_policy *policy) 2174 { 2175 if (!policy) 2176 return; 2177 2178 sidtab_destroy(policy->sidtab); 2179 kfree(policy->map.mapping); 2180 policydb_destroy(&policy->policydb); 2181 kfree(policy->sidtab); 2182 kfree(policy); 2183 } 2184 2185 static void selinux_policy_cond_free(struct selinux_policy *policy) 2186 { 2187 cond_policydb_destroy_dup(&policy->policydb); 2188 kfree(policy); 2189 } 2190 2191 void selinux_policy_cancel(struct selinux_state *state, 2192 struct selinux_load_state *load_state) 2193 { 2194 struct selinux_policy *oldpolicy; 2195 2196 oldpolicy = rcu_dereference_protected(state->policy, 2197 lockdep_is_held(&state->policy_mutex)); 2198 2199 sidtab_cancel_convert(oldpolicy->sidtab); 2200 selinux_policy_free(load_state->policy); 2201 kfree(load_state->convert_data); 2202 } 2203 2204 static void selinux_notify_policy_change(struct selinux_state *state, 2205 u32 seqno) 2206 { 2207 /* Flush external caches and notify userspace of policy load */ 2208 avc_ss_reset(state->avc, seqno); 2209 selnl_notify_policyload(seqno); 2210 selinux_status_update_policyload(state, seqno); 2211 selinux_netlbl_cache_invalidate(); 2212 selinux_xfrm_notify_policyload(); 2213 selinux_ima_measure_state_locked(state); 2214 } 2215 2216 void selinux_policy_commit(struct selinux_state *state, 2217 struct selinux_load_state *load_state) 2218 { 2219 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2220 unsigned long flags; 2221 u32 seqno; 2222 2223 oldpolicy = rcu_dereference_protected(state->policy, 2224 lockdep_is_held(&state->policy_mutex)); 2225 2226 /* If switching between different policy types, log MLS status */ 2227 if (oldpolicy) { 2228 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2229 pr_info("SELinux: Disabling MLS support...\n"); 2230 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2231 pr_info("SELinux: Enabling MLS support...\n"); 2232 } 2233 2234 /* Set latest granting seqno for new policy. */ 2235 if (oldpolicy) 2236 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2237 else 2238 newpolicy->latest_granting = 1; 2239 seqno = newpolicy->latest_granting; 2240 2241 /* Install the new policy. */ 2242 if (oldpolicy) { 2243 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2244 rcu_assign_pointer(state->policy, newpolicy); 2245 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2246 } else { 2247 rcu_assign_pointer(state->policy, newpolicy); 2248 } 2249 2250 /* Load the policycaps from the new policy */ 2251 security_load_policycaps(state, newpolicy); 2252 2253 if (!selinux_initialized(state)) { 2254 /* 2255 * After first policy load, the security server is 2256 * marked as initialized and ready to handle requests and 2257 * any objects created prior to policy load are then labeled. 2258 */ 2259 selinux_mark_initialized(state); 2260 selinux_complete_init(); 2261 } 2262 2263 /* Free the old policy */ 2264 synchronize_rcu(); 2265 selinux_policy_free(oldpolicy); 2266 kfree(load_state->convert_data); 2267 2268 /* Notify others of the policy change */ 2269 selinux_notify_policy_change(state, seqno); 2270 } 2271 2272 /** 2273 * security_load_policy - Load a security policy configuration. 2274 * @state: SELinux state 2275 * @data: binary policy data 2276 * @len: length of data in bytes 2277 * @load_state: policy load state 2278 * 2279 * Load a new set of security policy configuration data, 2280 * validate it and convert the SID table as necessary. 2281 * This function will flush the access vector cache after 2282 * loading the new policy. 2283 */ 2284 int security_load_policy(struct selinux_state *state, void *data, size_t len, 2285 struct selinux_load_state *load_state) 2286 { 2287 struct selinux_policy *newpolicy, *oldpolicy; 2288 struct selinux_policy_convert_data *convert_data; 2289 int rc = 0; 2290 struct policy_file file = { data, len }, *fp = &file; 2291 2292 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); 2293 if (!newpolicy) 2294 return -ENOMEM; 2295 2296 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); 2297 if (!newpolicy->sidtab) { 2298 rc = -ENOMEM; 2299 goto err_policy; 2300 } 2301 2302 rc = policydb_read(&newpolicy->policydb, fp); 2303 if (rc) 2304 goto err_sidtab; 2305 2306 newpolicy->policydb.len = len; 2307 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, 2308 &newpolicy->map); 2309 if (rc) 2310 goto err_policydb; 2311 2312 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); 2313 if (rc) { 2314 pr_err("SELinux: unable to load the initial SIDs\n"); 2315 goto err_mapping; 2316 } 2317 2318 if (!selinux_initialized(state)) { 2319 /* First policy load, so no need to preserve state from old policy */ 2320 load_state->policy = newpolicy; 2321 load_state->convert_data = NULL; 2322 return 0; 2323 } 2324 2325 oldpolicy = rcu_dereference_protected(state->policy, 2326 lockdep_is_held(&state->policy_mutex)); 2327 2328 /* Preserve active boolean values from the old policy */ 2329 rc = security_preserve_bools(oldpolicy, newpolicy); 2330 if (rc) { 2331 pr_err("SELinux: unable to preserve booleans\n"); 2332 goto err_free_isids; 2333 } 2334 2335 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2336 if (!convert_data) { 2337 rc = -ENOMEM; 2338 goto err_free_isids; 2339 } 2340 2341 /* 2342 * Convert the internal representations of contexts 2343 * in the new SID table. 2344 */ 2345 convert_data->args.state = state; 2346 convert_data->args.oldp = &oldpolicy->policydb; 2347 convert_data->args.newp = &newpolicy->policydb; 2348 2349 convert_data->sidtab_params.func = convert_context; 2350 convert_data->sidtab_params.args = &convert_data->args; 2351 convert_data->sidtab_params.target = newpolicy->sidtab; 2352 2353 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); 2354 if (rc) { 2355 pr_err("SELinux: unable to convert the internal" 2356 " representation of contexts in the new SID" 2357 " table\n"); 2358 goto err_free_convert_data; 2359 } 2360 2361 load_state->policy = newpolicy; 2362 load_state->convert_data = convert_data; 2363 return 0; 2364 2365 err_free_convert_data: 2366 kfree(convert_data); 2367 err_free_isids: 2368 sidtab_destroy(newpolicy->sidtab); 2369 err_mapping: 2370 kfree(newpolicy->map.mapping); 2371 err_policydb: 2372 policydb_destroy(&newpolicy->policydb); 2373 err_sidtab: 2374 kfree(newpolicy->sidtab); 2375 err_policy: 2376 kfree(newpolicy); 2377 2378 return rc; 2379 } 2380 2381 /** 2382 * ocontext_to_sid - Helper to safely get sid for an ocontext 2383 * @sidtab: SID table 2384 * @c: ocontext structure 2385 * @index: index of the context entry (0 or 1) 2386 * @out_sid: pointer to the resulting SID value 2387 * 2388 * For all ocontexts except OCON_ISID the SID fields are populated 2389 * on-demand when needed. Since updating the SID value is an SMP-sensitive 2390 * operation, this helper must be used to do that safely. 2391 * 2392 * WARNING: This function may return -ESTALE, indicating that the caller 2393 * must retry the operation after re-acquiring the policy pointer! 2394 */ 2395 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, 2396 size_t index, u32 *out_sid) 2397 { 2398 int rc; 2399 u32 sid; 2400 2401 /* Ensure the associated sidtab entry is visible to this thread. */ 2402 sid = smp_load_acquire(&c->sid[index]); 2403 if (!sid) { 2404 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); 2405 if (rc) 2406 return rc; 2407 2408 /* 2409 * Ensure the new sidtab entry is visible to other threads 2410 * when they see the SID. 2411 */ 2412 smp_store_release(&c->sid[index], sid); 2413 } 2414 *out_sid = sid; 2415 return 0; 2416 } 2417 2418 /** 2419 * security_port_sid - Obtain the SID for a port. 2420 * @state: SELinux state 2421 * @protocol: protocol number 2422 * @port: port number 2423 * @out_sid: security identifier 2424 */ 2425 int security_port_sid(struct selinux_state *state, 2426 u8 protocol, u16 port, u32 *out_sid) 2427 { 2428 struct selinux_policy *policy; 2429 struct policydb *policydb; 2430 struct sidtab *sidtab; 2431 struct ocontext *c; 2432 int rc; 2433 2434 if (!selinux_initialized(state)) { 2435 *out_sid = SECINITSID_PORT; 2436 return 0; 2437 } 2438 2439 retry: 2440 rc = 0; 2441 rcu_read_lock(); 2442 policy = rcu_dereference(state->policy); 2443 policydb = &policy->policydb; 2444 sidtab = policy->sidtab; 2445 2446 c = policydb->ocontexts[OCON_PORT]; 2447 while (c) { 2448 if (c->u.port.protocol == protocol && 2449 c->u.port.low_port <= port && 2450 c->u.port.high_port >= port) 2451 break; 2452 c = c->next; 2453 } 2454 2455 if (c) { 2456 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2457 if (rc == -ESTALE) { 2458 rcu_read_unlock(); 2459 goto retry; 2460 } 2461 if (rc) 2462 goto out; 2463 } else { 2464 *out_sid = SECINITSID_PORT; 2465 } 2466 2467 out: 2468 rcu_read_unlock(); 2469 return rc; 2470 } 2471 2472 /** 2473 * security_ib_pkey_sid - Obtain the SID for a pkey. 2474 * @state: SELinux state 2475 * @subnet_prefix: Subnet Prefix 2476 * @pkey_num: pkey number 2477 * @out_sid: security identifier 2478 */ 2479 int security_ib_pkey_sid(struct selinux_state *state, 2480 u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2481 { 2482 struct selinux_policy *policy; 2483 struct policydb *policydb; 2484 struct sidtab *sidtab; 2485 struct ocontext *c; 2486 int rc; 2487 2488 if (!selinux_initialized(state)) { 2489 *out_sid = SECINITSID_UNLABELED; 2490 return 0; 2491 } 2492 2493 retry: 2494 rc = 0; 2495 rcu_read_lock(); 2496 policy = rcu_dereference(state->policy); 2497 policydb = &policy->policydb; 2498 sidtab = policy->sidtab; 2499 2500 c = policydb->ocontexts[OCON_IBPKEY]; 2501 while (c) { 2502 if (c->u.ibpkey.low_pkey <= pkey_num && 2503 c->u.ibpkey.high_pkey >= pkey_num && 2504 c->u.ibpkey.subnet_prefix == subnet_prefix) 2505 break; 2506 2507 c = c->next; 2508 } 2509 2510 if (c) { 2511 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2512 if (rc == -ESTALE) { 2513 rcu_read_unlock(); 2514 goto retry; 2515 } 2516 if (rc) 2517 goto out; 2518 } else 2519 *out_sid = SECINITSID_UNLABELED; 2520 2521 out: 2522 rcu_read_unlock(); 2523 return rc; 2524 } 2525 2526 /** 2527 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2528 * @state: SELinux state 2529 * @dev_name: device name 2530 * @port_num: port number 2531 * @out_sid: security identifier 2532 */ 2533 int security_ib_endport_sid(struct selinux_state *state, 2534 const char *dev_name, u8 port_num, u32 *out_sid) 2535 { 2536 struct selinux_policy *policy; 2537 struct policydb *policydb; 2538 struct sidtab *sidtab; 2539 struct ocontext *c; 2540 int rc; 2541 2542 if (!selinux_initialized(state)) { 2543 *out_sid = SECINITSID_UNLABELED; 2544 return 0; 2545 } 2546 2547 retry: 2548 rc = 0; 2549 rcu_read_lock(); 2550 policy = rcu_dereference(state->policy); 2551 policydb = &policy->policydb; 2552 sidtab = policy->sidtab; 2553 2554 c = policydb->ocontexts[OCON_IBENDPORT]; 2555 while (c) { 2556 if (c->u.ibendport.port == port_num && 2557 !strncmp(c->u.ibendport.dev_name, 2558 dev_name, 2559 IB_DEVICE_NAME_MAX)) 2560 break; 2561 2562 c = c->next; 2563 } 2564 2565 if (c) { 2566 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2567 if (rc == -ESTALE) { 2568 rcu_read_unlock(); 2569 goto retry; 2570 } 2571 if (rc) 2572 goto out; 2573 } else 2574 *out_sid = SECINITSID_UNLABELED; 2575 2576 out: 2577 rcu_read_unlock(); 2578 return rc; 2579 } 2580 2581 /** 2582 * security_netif_sid - Obtain the SID for a network interface. 2583 * @state: SELinux state 2584 * @name: interface name 2585 * @if_sid: interface SID 2586 */ 2587 int security_netif_sid(struct selinux_state *state, 2588 char *name, u32 *if_sid) 2589 { 2590 struct selinux_policy *policy; 2591 struct policydb *policydb; 2592 struct sidtab *sidtab; 2593 int rc; 2594 struct ocontext *c; 2595 2596 if (!selinux_initialized(state)) { 2597 *if_sid = SECINITSID_NETIF; 2598 return 0; 2599 } 2600 2601 retry: 2602 rc = 0; 2603 rcu_read_lock(); 2604 policy = rcu_dereference(state->policy); 2605 policydb = &policy->policydb; 2606 sidtab = policy->sidtab; 2607 2608 c = policydb->ocontexts[OCON_NETIF]; 2609 while (c) { 2610 if (strcmp(name, c->u.name) == 0) 2611 break; 2612 c = c->next; 2613 } 2614 2615 if (c) { 2616 rc = ocontext_to_sid(sidtab, c, 0, if_sid); 2617 if (rc == -ESTALE) { 2618 rcu_read_unlock(); 2619 goto retry; 2620 } 2621 if (rc) 2622 goto out; 2623 } else 2624 *if_sid = SECINITSID_NETIF; 2625 2626 out: 2627 rcu_read_unlock(); 2628 return rc; 2629 } 2630 2631 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2632 { 2633 int i, fail = 0; 2634 2635 for (i = 0; i < 4; i++) 2636 if (addr[i] != (input[i] & mask[i])) { 2637 fail = 1; 2638 break; 2639 } 2640 2641 return !fail; 2642 } 2643 2644 /** 2645 * security_node_sid - Obtain the SID for a node (host). 2646 * @state: SELinux state 2647 * @domain: communication domain aka address family 2648 * @addrp: address 2649 * @addrlen: address length in bytes 2650 * @out_sid: security identifier 2651 */ 2652 int security_node_sid(struct selinux_state *state, 2653 u16 domain, 2654 void *addrp, 2655 u32 addrlen, 2656 u32 *out_sid) 2657 { 2658 struct selinux_policy *policy; 2659 struct policydb *policydb; 2660 struct sidtab *sidtab; 2661 int rc; 2662 struct ocontext *c; 2663 2664 if (!selinux_initialized(state)) { 2665 *out_sid = SECINITSID_NODE; 2666 return 0; 2667 } 2668 2669 retry: 2670 rcu_read_lock(); 2671 policy = rcu_dereference(state->policy); 2672 policydb = &policy->policydb; 2673 sidtab = policy->sidtab; 2674 2675 switch (domain) { 2676 case AF_INET: { 2677 u32 addr; 2678 2679 rc = -EINVAL; 2680 if (addrlen != sizeof(u32)) 2681 goto out; 2682 2683 addr = *((u32 *)addrp); 2684 2685 c = policydb->ocontexts[OCON_NODE]; 2686 while (c) { 2687 if (c->u.node.addr == (addr & c->u.node.mask)) 2688 break; 2689 c = c->next; 2690 } 2691 break; 2692 } 2693 2694 case AF_INET6: 2695 rc = -EINVAL; 2696 if (addrlen != sizeof(u64) * 2) 2697 goto out; 2698 c = policydb->ocontexts[OCON_NODE6]; 2699 while (c) { 2700 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2701 c->u.node6.mask)) 2702 break; 2703 c = c->next; 2704 } 2705 break; 2706 2707 default: 2708 rc = 0; 2709 *out_sid = SECINITSID_NODE; 2710 goto out; 2711 } 2712 2713 if (c) { 2714 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2715 if (rc == -ESTALE) { 2716 rcu_read_unlock(); 2717 goto retry; 2718 } 2719 if (rc) 2720 goto out; 2721 } else { 2722 *out_sid = SECINITSID_NODE; 2723 } 2724 2725 rc = 0; 2726 out: 2727 rcu_read_unlock(); 2728 return rc; 2729 } 2730 2731 #define SIDS_NEL 25 2732 2733 /** 2734 * security_get_user_sids - Obtain reachable SIDs for a user. 2735 * @state: SELinux state 2736 * @fromsid: starting SID 2737 * @username: username 2738 * @sids: array of reachable SIDs for user 2739 * @nel: number of elements in @sids 2740 * 2741 * Generate the set of SIDs for legal security contexts 2742 * for a given user that can be reached by @fromsid. 2743 * Set *@sids to point to a dynamically allocated 2744 * array containing the set of SIDs. Set *@nel to the 2745 * number of elements in the array. 2746 */ 2747 2748 int security_get_user_sids(struct selinux_state *state, 2749 u32 fromsid, 2750 char *username, 2751 u32 **sids, 2752 u32 *nel) 2753 { 2754 struct selinux_policy *policy; 2755 struct policydb *policydb; 2756 struct sidtab *sidtab; 2757 struct context *fromcon, usercon; 2758 u32 *mysids = NULL, *mysids2, sid; 2759 u32 i, j, mynel, maxnel = SIDS_NEL; 2760 struct user_datum *user; 2761 struct role_datum *role; 2762 struct ebitmap_node *rnode, *tnode; 2763 int rc; 2764 2765 *sids = NULL; 2766 *nel = 0; 2767 2768 if (!selinux_initialized(state)) 2769 return 0; 2770 2771 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2772 if (!mysids) 2773 return -ENOMEM; 2774 2775 retry: 2776 mynel = 0; 2777 rcu_read_lock(); 2778 policy = rcu_dereference(state->policy); 2779 policydb = &policy->policydb; 2780 sidtab = policy->sidtab; 2781 2782 context_init(&usercon); 2783 2784 rc = -EINVAL; 2785 fromcon = sidtab_search(sidtab, fromsid); 2786 if (!fromcon) 2787 goto out_unlock; 2788 2789 rc = -EINVAL; 2790 user = symtab_search(&policydb->p_users, username); 2791 if (!user) 2792 goto out_unlock; 2793 2794 usercon.user = user->value; 2795 2796 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2797 role = policydb->role_val_to_struct[i]; 2798 usercon.role = i + 1; 2799 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2800 usercon.type = j + 1; 2801 2802 if (mls_setup_user_range(policydb, fromcon, user, 2803 &usercon)) 2804 continue; 2805 2806 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2807 if (rc == -ESTALE) { 2808 rcu_read_unlock(); 2809 goto retry; 2810 } 2811 if (rc) 2812 goto out_unlock; 2813 if (mynel < maxnel) { 2814 mysids[mynel++] = sid; 2815 } else { 2816 rc = -ENOMEM; 2817 maxnel += SIDS_NEL; 2818 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2819 if (!mysids2) 2820 goto out_unlock; 2821 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2822 kfree(mysids); 2823 mysids = mysids2; 2824 mysids[mynel++] = sid; 2825 } 2826 } 2827 } 2828 rc = 0; 2829 out_unlock: 2830 rcu_read_unlock(); 2831 if (rc || !mynel) { 2832 kfree(mysids); 2833 return rc; 2834 } 2835 2836 rc = -ENOMEM; 2837 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2838 if (!mysids2) { 2839 kfree(mysids); 2840 return rc; 2841 } 2842 for (i = 0, j = 0; i < mynel; i++) { 2843 struct av_decision dummy_avd; 2844 rc = avc_has_perm_noaudit(state, 2845 fromsid, mysids[i], 2846 SECCLASS_PROCESS, /* kernel value */ 2847 PROCESS__TRANSITION, AVC_STRICT, 2848 &dummy_avd); 2849 if (!rc) 2850 mysids2[j++] = mysids[i]; 2851 cond_resched(); 2852 } 2853 kfree(mysids); 2854 *sids = mysids2; 2855 *nel = j; 2856 return 0; 2857 } 2858 2859 /** 2860 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2861 * @policy: policy 2862 * @fstype: filesystem type 2863 * @path: path from root of mount 2864 * @orig_sclass: file security class 2865 * @sid: SID for path 2866 * 2867 * Obtain a SID to use for a file in a filesystem that 2868 * cannot support xattr or use a fixed labeling behavior like 2869 * transition SIDs or task SIDs. 2870 * 2871 * WARNING: This function may return -ESTALE, indicating that the caller 2872 * must retry the operation after re-acquiring the policy pointer! 2873 */ 2874 static inline int __security_genfs_sid(struct selinux_policy *policy, 2875 const char *fstype, 2876 const char *path, 2877 u16 orig_sclass, 2878 u32 *sid) 2879 { 2880 struct policydb *policydb = &policy->policydb; 2881 struct sidtab *sidtab = policy->sidtab; 2882 int len; 2883 u16 sclass; 2884 struct genfs *genfs; 2885 struct ocontext *c; 2886 int cmp = 0; 2887 2888 while (path[0] == '/' && path[1] == '/') 2889 path++; 2890 2891 sclass = unmap_class(&policy->map, orig_sclass); 2892 *sid = SECINITSID_UNLABELED; 2893 2894 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2895 cmp = strcmp(fstype, genfs->fstype); 2896 if (cmp <= 0) 2897 break; 2898 } 2899 2900 if (!genfs || cmp) 2901 return -ENOENT; 2902 2903 for (c = genfs->head; c; c = c->next) { 2904 len = strlen(c->u.name); 2905 if ((!c->v.sclass || sclass == c->v.sclass) && 2906 (strncmp(c->u.name, path, len) == 0)) 2907 break; 2908 } 2909 2910 if (!c) 2911 return -ENOENT; 2912 2913 return ocontext_to_sid(sidtab, c, 0, sid); 2914 } 2915 2916 /** 2917 * security_genfs_sid - Obtain a SID for a file in a filesystem 2918 * @state: SELinux state 2919 * @fstype: filesystem type 2920 * @path: path from root of mount 2921 * @orig_sclass: file security class 2922 * @sid: SID for path 2923 * 2924 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2925 * it afterward. 2926 */ 2927 int security_genfs_sid(struct selinux_state *state, 2928 const char *fstype, 2929 const char *path, 2930 u16 orig_sclass, 2931 u32 *sid) 2932 { 2933 struct selinux_policy *policy; 2934 int retval; 2935 2936 if (!selinux_initialized(state)) { 2937 *sid = SECINITSID_UNLABELED; 2938 return 0; 2939 } 2940 2941 do { 2942 rcu_read_lock(); 2943 policy = rcu_dereference(state->policy); 2944 retval = __security_genfs_sid(policy, fstype, path, 2945 orig_sclass, sid); 2946 rcu_read_unlock(); 2947 } while (retval == -ESTALE); 2948 return retval; 2949 } 2950 2951 int selinux_policy_genfs_sid(struct selinux_policy *policy, 2952 const char *fstype, 2953 const char *path, 2954 u16 orig_sclass, 2955 u32 *sid) 2956 { 2957 /* no lock required, policy is not yet accessible by other threads */ 2958 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2959 } 2960 2961 /** 2962 * security_fs_use - Determine how to handle labeling for a filesystem. 2963 * @state: SELinux state 2964 * @sb: superblock in question 2965 */ 2966 int security_fs_use(struct selinux_state *state, struct super_block *sb) 2967 { 2968 struct selinux_policy *policy; 2969 struct policydb *policydb; 2970 struct sidtab *sidtab; 2971 int rc; 2972 struct ocontext *c; 2973 struct superblock_security_struct *sbsec = selinux_superblock(sb); 2974 const char *fstype = sb->s_type->name; 2975 2976 if (!selinux_initialized(state)) { 2977 sbsec->behavior = SECURITY_FS_USE_NONE; 2978 sbsec->sid = SECINITSID_UNLABELED; 2979 return 0; 2980 } 2981 2982 retry: 2983 rcu_read_lock(); 2984 policy = rcu_dereference(state->policy); 2985 policydb = &policy->policydb; 2986 sidtab = policy->sidtab; 2987 2988 c = policydb->ocontexts[OCON_FSUSE]; 2989 while (c) { 2990 if (strcmp(fstype, c->u.name) == 0) 2991 break; 2992 c = c->next; 2993 } 2994 2995 if (c) { 2996 sbsec->behavior = c->v.behavior; 2997 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); 2998 if (rc == -ESTALE) { 2999 rcu_read_unlock(); 3000 goto retry; 3001 } 3002 if (rc) 3003 goto out; 3004 } else { 3005 rc = __security_genfs_sid(policy, fstype, "/", 3006 SECCLASS_DIR, &sbsec->sid); 3007 if (rc == -ESTALE) { 3008 rcu_read_unlock(); 3009 goto retry; 3010 } 3011 if (rc) { 3012 sbsec->behavior = SECURITY_FS_USE_NONE; 3013 rc = 0; 3014 } else { 3015 sbsec->behavior = SECURITY_FS_USE_GENFS; 3016 } 3017 } 3018 3019 out: 3020 rcu_read_unlock(); 3021 return rc; 3022 } 3023 3024 int security_get_bools(struct selinux_policy *policy, 3025 u32 *len, char ***names, int **values) 3026 { 3027 struct policydb *policydb; 3028 u32 i; 3029 int rc; 3030 3031 policydb = &policy->policydb; 3032 3033 *names = NULL; 3034 *values = NULL; 3035 3036 rc = 0; 3037 *len = policydb->p_bools.nprim; 3038 if (!*len) 3039 goto out; 3040 3041 rc = -ENOMEM; 3042 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 3043 if (!*names) 3044 goto err; 3045 3046 rc = -ENOMEM; 3047 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 3048 if (!*values) 3049 goto err; 3050 3051 for (i = 0; i < *len; i++) { 3052 (*values)[i] = policydb->bool_val_to_struct[i]->state; 3053 3054 rc = -ENOMEM; 3055 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 3056 GFP_ATOMIC); 3057 if (!(*names)[i]) 3058 goto err; 3059 } 3060 rc = 0; 3061 out: 3062 return rc; 3063 err: 3064 if (*names) { 3065 for (i = 0; i < *len; i++) 3066 kfree((*names)[i]); 3067 kfree(*names); 3068 } 3069 kfree(*values); 3070 *len = 0; 3071 *names = NULL; 3072 *values = NULL; 3073 goto out; 3074 } 3075 3076 3077 int security_set_bools(struct selinux_state *state, u32 len, int *values) 3078 { 3079 struct selinux_policy *newpolicy, *oldpolicy; 3080 int rc; 3081 u32 i, seqno = 0; 3082 3083 if (!selinux_initialized(state)) 3084 return -EINVAL; 3085 3086 oldpolicy = rcu_dereference_protected(state->policy, 3087 lockdep_is_held(&state->policy_mutex)); 3088 3089 /* Consistency check on number of booleans, should never fail */ 3090 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) 3091 return -EINVAL; 3092 3093 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); 3094 if (!newpolicy) 3095 return -ENOMEM; 3096 3097 /* 3098 * Deep copy only the parts of the policydb that might be 3099 * modified as a result of changing booleans. 3100 */ 3101 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); 3102 if (rc) { 3103 kfree(newpolicy); 3104 return -ENOMEM; 3105 } 3106 3107 /* Update the boolean states in the copy */ 3108 for (i = 0; i < len; i++) { 3109 int new_state = !!values[i]; 3110 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; 3111 3112 if (new_state != old_state) { 3113 audit_log(audit_context(), GFP_ATOMIC, 3114 AUDIT_MAC_CONFIG_CHANGE, 3115 "bool=%s val=%d old_val=%d auid=%u ses=%u", 3116 sym_name(&newpolicy->policydb, SYM_BOOLS, i), 3117 new_state, 3118 old_state, 3119 from_kuid(&init_user_ns, audit_get_loginuid(current)), 3120 audit_get_sessionid(current)); 3121 newpolicy->policydb.bool_val_to_struct[i]->state = new_state; 3122 } 3123 } 3124 3125 /* Re-evaluate the conditional rules in the copy */ 3126 evaluate_cond_nodes(&newpolicy->policydb); 3127 3128 /* Set latest granting seqno for new policy */ 3129 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 3130 seqno = newpolicy->latest_granting; 3131 3132 /* Install the new policy */ 3133 rcu_assign_pointer(state->policy, newpolicy); 3134 3135 /* 3136 * Free the conditional portions of the old policydb 3137 * that were copied for the new policy, and the oldpolicy 3138 * structure itself but not what it references. 3139 */ 3140 synchronize_rcu(); 3141 selinux_policy_cond_free(oldpolicy); 3142 3143 /* Notify others of the policy change */ 3144 selinux_notify_policy_change(state, seqno); 3145 return 0; 3146 } 3147 3148 int security_get_bool_value(struct selinux_state *state, 3149 u32 index) 3150 { 3151 struct selinux_policy *policy; 3152 struct policydb *policydb; 3153 int rc; 3154 u32 len; 3155 3156 if (!selinux_initialized(state)) 3157 return 0; 3158 3159 rcu_read_lock(); 3160 policy = rcu_dereference(state->policy); 3161 policydb = &policy->policydb; 3162 3163 rc = -EFAULT; 3164 len = policydb->p_bools.nprim; 3165 if (index >= len) 3166 goto out; 3167 3168 rc = policydb->bool_val_to_struct[index]->state; 3169 out: 3170 rcu_read_unlock(); 3171 return rc; 3172 } 3173 3174 static int security_preserve_bools(struct selinux_policy *oldpolicy, 3175 struct selinux_policy *newpolicy) 3176 { 3177 int rc, *bvalues = NULL; 3178 char **bnames = NULL; 3179 struct cond_bool_datum *booldatum; 3180 u32 i, nbools = 0; 3181 3182 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); 3183 if (rc) 3184 goto out; 3185 for (i = 0; i < nbools; i++) { 3186 booldatum = symtab_search(&newpolicy->policydb.p_bools, 3187 bnames[i]); 3188 if (booldatum) 3189 booldatum->state = bvalues[i]; 3190 } 3191 evaluate_cond_nodes(&newpolicy->policydb); 3192 3193 out: 3194 if (bnames) { 3195 for (i = 0; i < nbools; i++) 3196 kfree(bnames[i]); 3197 } 3198 kfree(bnames); 3199 kfree(bvalues); 3200 return rc; 3201 } 3202 3203 /* 3204 * security_sid_mls_copy() - computes a new sid based on the given 3205 * sid and the mls portion of mls_sid. 3206 */ 3207 int security_sid_mls_copy(struct selinux_state *state, 3208 u32 sid, u32 mls_sid, u32 *new_sid) 3209 { 3210 struct selinux_policy *policy; 3211 struct policydb *policydb; 3212 struct sidtab *sidtab; 3213 struct context *context1; 3214 struct context *context2; 3215 struct context newcon; 3216 char *s; 3217 u32 len; 3218 int rc; 3219 3220 if (!selinux_initialized(state)) { 3221 *new_sid = sid; 3222 return 0; 3223 } 3224 3225 retry: 3226 rc = 0; 3227 context_init(&newcon); 3228 3229 rcu_read_lock(); 3230 policy = rcu_dereference(state->policy); 3231 policydb = &policy->policydb; 3232 sidtab = policy->sidtab; 3233 3234 if (!policydb->mls_enabled) { 3235 *new_sid = sid; 3236 goto out_unlock; 3237 } 3238 3239 rc = -EINVAL; 3240 context1 = sidtab_search(sidtab, sid); 3241 if (!context1) { 3242 pr_err("SELinux: %s: unrecognized SID %d\n", 3243 __func__, sid); 3244 goto out_unlock; 3245 } 3246 3247 rc = -EINVAL; 3248 context2 = sidtab_search(sidtab, mls_sid); 3249 if (!context2) { 3250 pr_err("SELinux: %s: unrecognized SID %d\n", 3251 __func__, mls_sid); 3252 goto out_unlock; 3253 } 3254 3255 newcon.user = context1->user; 3256 newcon.role = context1->role; 3257 newcon.type = context1->type; 3258 rc = mls_context_cpy(&newcon, context2); 3259 if (rc) 3260 goto out_unlock; 3261 3262 /* Check the validity of the new context. */ 3263 if (!policydb_context_isvalid(policydb, &newcon)) { 3264 rc = convert_context_handle_invalid_context(state, policydb, 3265 &newcon); 3266 if (rc) { 3267 if (!context_struct_to_string(policydb, &newcon, &s, 3268 &len)) { 3269 struct audit_buffer *ab; 3270 3271 ab = audit_log_start(audit_context(), 3272 GFP_ATOMIC, 3273 AUDIT_SELINUX_ERR); 3274 audit_log_format(ab, 3275 "op=security_sid_mls_copy invalid_context="); 3276 /* don't record NUL with untrusted strings */ 3277 audit_log_n_untrustedstring(ab, s, len - 1); 3278 audit_log_end(ab); 3279 kfree(s); 3280 } 3281 goto out_unlock; 3282 } 3283 } 3284 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3285 if (rc == -ESTALE) { 3286 rcu_read_unlock(); 3287 context_destroy(&newcon); 3288 goto retry; 3289 } 3290 out_unlock: 3291 rcu_read_unlock(); 3292 context_destroy(&newcon); 3293 return rc; 3294 } 3295 3296 /** 3297 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3298 * @state: SELinux state 3299 * @nlbl_sid: NetLabel SID 3300 * @nlbl_type: NetLabel labeling protocol type 3301 * @xfrm_sid: XFRM SID 3302 * @peer_sid: network peer sid 3303 * 3304 * Description: 3305 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3306 * resolved into a single SID it is returned via @peer_sid and the function 3307 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3308 * returns a negative value. A table summarizing the behavior is below: 3309 * 3310 * | function return | @sid 3311 * ------------------------------+-----------------+----------------- 3312 * no peer labels | 0 | SECSID_NULL 3313 * single peer label | 0 | <peer_label> 3314 * multiple, consistent labels | 0 | <peer_label> 3315 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3316 * 3317 */ 3318 int security_net_peersid_resolve(struct selinux_state *state, 3319 u32 nlbl_sid, u32 nlbl_type, 3320 u32 xfrm_sid, 3321 u32 *peer_sid) 3322 { 3323 struct selinux_policy *policy; 3324 struct policydb *policydb; 3325 struct sidtab *sidtab; 3326 int rc; 3327 struct context *nlbl_ctx; 3328 struct context *xfrm_ctx; 3329 3330 *peer_sid = SECSID_NULL; 3331 3332 /* handle the common (which also happens to be the set of easy) cases 3333 * right away, these two if statements catch everything involving a 3334 * single or absent peer SID/label */ 3335 if (xfrm_sid == SECSID_NULL) { 3336 *peer_sid = nlbl_sid; 3337 return 0; 3338 } 3339 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3340 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3341 * is present */ 3342 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3343 *peer_sid = xfrm_sid; 3344 return 0; 3345 } 3346 3347 if (!selinux_initialized(state)) 3348 return 0; 3349 3350 rcu_read_lock(); 3351 policy = rcu_dereference(state->policy); 3352 policydb = &policy->policydb; 3353 sidtab = policy->sidtab; 3354 3355 /* 3356 * We don't need to check initialized here since the only way both 3357 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3358 * security server was initialized and state->initialized was true. 3359 */ 3360 if (!policydb->mls_enabled) { 3361 rc = 0; 3362 goto out; 3363 } 3364 3365 rc = -EINVAL; 3366 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3367 if (!nlbl_ctx) { 3368 pr_err("SELinux: %s: unrecognized SID %d\n", 3369 __func__, nlbl_sid); 3370 goto out; 3371 } 3372 rc = -EINVAL; 3373 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3374 if (!xfrm_ctx) { 3375 pr_err("SELinux: %s: unrecognized SID %d\n", 3376 __func__, xfrm_sid); 3377 goto out; 3378 } 3379 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3380 if (rc) 3381 goto out; 3382 3383 /* at present NetLabel SIDs/labels really only carry MLS 3384 * information so if the MLS portion of the NetLabel SID 3385 * matches the MLS portion of the labeled XFRM SID/label 3386 * then pass along the XFRM SID as it is the most 3387 * expressive */ 3388 *peer_sid = xfrm_sid; 3389 out: 3390 rcu_read_unlock(); 3391 return rc; 3392 } 3393 3394 static int get_classes_callback(void *k, void *d, void *args) 3395 { 3396 struct class_datum *datum = d; 3397 char *name = k, **classes = args; 3398 int value = datum->value - 1; 3399 3400 classes[value] = kstrdup(name, GFP_ATOMIC); 3401 if (!classes[value]) 3402 return -ENOMEM; 3403 3404 return 0; 3405 } 3406 3407 int security_get_classes(struct selinux_policy *policy, 3408 char ***classes, int *nclasses) 3409 { 3410 struct policydb *policydb; 3411 int rc; 3412 3413 policydb = &policy->policydb; 3414 3415 rc = -ENOMEM; 3416 *nclasses = policydb->p_classes.nprim; 3417 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3418 if (!*classes) 3419 goto out; 3420 3421 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3422 *classes); 3423 if (rc) { 3424 int i; 3425 for (i = 0; i < *nclasses; i++) 3426 kfree((*classes)[i]); 3427 kfree(*classes); 3428 } 3429 3430 out: 3431 return rc; 3432 } 3433 3434 static int get_permissions_callback(void *k, void *d, void *args) 3435 { 3436 struct perm_datum *datum = d; 3437 char *name = k, **perms = args; 3438 int value = datum->value - 1; 3439 3440 perms[value] = kstrdup(name, GFP_ATOMIC); 3441 if (!perms[value]) 3442 return -ENOMEM; 3443 3444 return 0; 3445 } 3446 3447 int security_get_permissions(struct selinux_policy *policy, 3448 char *class, char ***perms, int *nperms) 3449 { 3450 struct policydb *policydb; 3451 int rc, i; 3452 struct class_datum *match; 3453 3454 policydb = &policy->policydb; 3455 3456 rc = -EINVAL; 3457 match = symtab_search(&policydb->p_classes, class); 3458 if (!match) { 3459 pr_err("SELinux: %s: unrecognized class %s\n", 3460 __func__, class); 3461 goto out; 3462 } 3463 3464 rc = -ENOMEM; 3465 *nperms = match->permissions.nprim; 3466 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3467 if (!*perms) 3468 goto out; 3469 3470 if (match->comdatum) { 3471 rc = hashtab_map(&match->comdatum->permissions.table, 3472 get_permissions_callback, *perms); 3473 if (rc) 3474 goto err; 3475 } 3476 3477 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3478 *perms); 3479 if (rc) 3480 goto err; 3481 3482 out: 3483 return rc; 3484 3485 err: 3486 for (i = 0; i < *nperms; i++) 3487 kfree((*perms)[i]); 3488 kfree(*perms); 3489 return rc; 3490 } 3491 3492 int security_get_reject_unknown(struct selinux_state *state) 3493 { 3494 struct selinux_policy *policy; 3495 int value; 3496 3497 if (!selinux_initialized(state)) 3498 return 0; 3499 3500 rcu_read_lock(); 3501 policy = rcu_dereference(state->policy); 3502 value = policy->policydb.reject_unknown; 3503 rcu_read_unlock(); 3504 return value; 3505 } 3506 3507 int security_get_allow_unknown(struct selinux_state *state) 3508 { 3509 struct selinux_policy *policy; 3510 int value; 3511 3512 if (!selinux_initialized(state)) 3513 return 0; 3514 3515 rcu_read_lock(); 3516 policy = rcu_dereference(state->policy); 3517 value = policy->policydb.allow_unknown; 3518 rcu_read_unlock(); 3519 return value; 3520 } 3521 3522 /** 3523 * security_policycap_supported - Check for a specific policy capability 3524 * @state: SELinux state 3525 * @req_cap: capability 3526 * 3527 * Description: 3528 * This function queries the currently loaded policy to see if it supports the 3529 * capability specified by @req_cap. Returns true (1) if the capability is 3530 * supported, false (0) if it isn't supported. 3531 * 3532 */ 3533 int security_policycap_supported(struct selinux_state *state, 3534 unsigned int req_cap) 3535 { 3536 struct selinux_policy *policy; 3537 int rc; 3538 3539 if (!selinux_initialized(state)) 3540 return 0; 3541 3542 rcu_read_lock(); 3543 policy = rcu_dereference(state->policy); 3544 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3545 rcu_read_unlock(); 3546 3547 return rc; 3548 } 3549 3550 struct selinux_audit_rule { 3551 u32 au_seqno; 3552 struct context au_ctxt; 3553 }; 3554 3555 void selinux_audit_rule_free(void *vrule) 3556 { 3557 struct selinux_audit_rule *rule = vrule; 3558 3559 if (rule) { 3560 context_destroy(&rule->au_ctxt); 3561 kfree(rule); 3562 } 3563 } 3564 3565 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3566 { 3567 struct selinux_state *state = &selinux_state; 3568 struct selinux_policy *policy; 3569 struct policydb *policydb; 3570 struct selinux_audit_rule *tmprule; 3571 struct role_datum *roledatum; 3572 struct type_datum *typedatum; 3573 struct user_datum *userdatum; 3574 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3575 int rc = 0; 3576 3577 *rule = NULL; 3578 3579 if (!selinux_initialized(state)) 3580 return -EOPNOTSUPP; 3581 3582 switch (field) { 3583 case AUDIT_SUBJ_USER: 3584 case AUDIT_SUBJ_ROLE: 3585 case AUDIT_SUBJ_TYPE: 3586 case AUDIT_OBJ_USER: 3587 case AUDIT_OBJ_ROLE: 3588 case AUDIT_OBJ_TYPE: 3589 /* only 'equals' and 'not equals' fit user, role, and type */ 3590 if (op != Audit_equal && op != Audit_not_equal) 3591 return -EINVAL; 3592 break; 3593 case AUDIT_SUBJ_SEN: 3594 case AUDIT_SUBJ_CLR: 3595 case AUDIT_OBJ_LEV_LOW: 3596 case AUDIT_OBJ_LEV_HIGH: 3597 /* we do not allow a range, indicated by the presence of '-' */ 3598 if (strchr(rulestr, '-')) 3599 return -EINVAL; 3600 break; 3601 default: 3602 /* only the above fields are valid */ 3603 return -EINVAL; 3604 } 3605 3606 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3607 if (!tmprule) 3608 return -ENOMEM; 3609 3610 context_init(&tmprule->au_ctxt); 3611 3612 rcu_read_lock(); 3613 policy = rcu_dereference(state->policy); 3614 policydb = &policy->policydb; 3615 3616 tmprule->au_seqno = policy->latest_granting; 3617 3618 switch (field) { 3619 case AUDIT_SUBJ_USER: 3620 case AUDIT_OBJ_USER: 3621 rc = -EINVAL; 3622 userdatum = symtab_search(&policydb->p_users, rulestr); 3623 if (!userdatum) 3624 goto out; 3625 tmprule->au_ctxt.user = userdatum->value; 3626 break; 3627 case AUDIT_SUBJ_ROLE: 3628 case AUDIT_OBJ_ROLE: 3629 rc = -EINVAL; 3630 roledatum = symtab_search(&policydb->p_roles, rulestr); 3631 if (!roledatum) 3632 goto out; 3633 tmprule->au_ctxt.role = roledatum->value; 3634 break; 3635 case AUDIT_SUBJ_TYPE: 3636 case AUDIT_OBJ_TYPE: 3637 rc = -EINVAL; 3638 typedatum = symtab_search(&policydb->p_types, rulestr); 3639 if (!typedatum) 3640 goto out; 3641 tmprule->au_ctxt.type = typedatum->value; 3642 break; 3643 case AUDIT_SUBJ_SEN: 3644 case AUDIT_SUBJ_CLR: 3645 case AUDIT_OBJ_LEV_LOW: 3646 case AUDIT_OBJ_LEV_HIGH: 3647 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3648 GFP_ATOMIC); 3649 if (rc) 3650 goto out; 3651 break; 3652 } 3653 rc = 0; 3654 out: 3655 rcu_read_unlock(); 3656 3657 if (rc) { 3658 selinux_audit_rule_free(tmprule); 3659 tmprule = NULL; 3660 } 3661 3662 *rule = tmprule; 3663 3664 return rc; 3665 } 3666 3667 /* Check to see if the rule contains any selinux fields */ 3668 int selinux_audit_rule_known(struct audit_krule *rule) 3669 { 3670 int i; 3671 3672 for (i = 0; i < rule->field_count; i++) { 3673 struct audit_field *f = &rule->fields[i]; 3674 switch (f->type) { 3675 case AUDIT_SUBJ_USER: 3676 case AUDIT_SUBJ_ROLE: 3677 case AUDIT_SUBJ_TYPE: 3678 case AUDIT_SUBJ_SEN: 3679 case AUDIT_SUBJ_CLR: 3680 case AUDIT_OBJ_USER: 3681 case AUDIT_OBJ_ROLE: 3682 case AUDIT_OBJ_TYPE: 3683 case AUDIT_OBJ_LEV_LOW: 3684 case AUDIT_OBJ_LEV_HIGH: 3685 return 1; 3686 } 3687 } 3688 3689 return 0; 3690 } 3691 3692 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) 3693 { 3694 struct selinux_state *state = &selinux_state; 3695 struct selinux_policy *policy; 3696 struct context *ctxt; 3697 struct mls_level *level; 3698 struct selinux_audit_rule *rule = vrule; 3699 int match = 0; 3700 3701 if (unlikely(!rule)) { 3702 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3703 return -ENOENT; 3704 } 3705 3706 if (!selinux_initialized(state)) 3707 return 0; 3708 3709 rcu_read_lock(); 3710 3711 policy = rcu_dereference(state->policy); 3712 3713 if (rule->au_seqno < policy->latest_granting) { 3714 match = -ESTALE; 3715 goto out; 3716 } 3717 3718 ctxt = sidtab_search(policy->sidtab, sid); 3719 if (unlikely(!ctxt)) { 3720 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3721 sid); 3722 match = -ENOENT; 3723 goto out; 3724 } 3725 3726 /* a field/op pair that is not caught here will simply fall through 3727 without a match */ 3728 switch (field) { 3729 case AUDIT_SUBJ_USER: 3730 case AUDIT_OBJ_USER: 3731 switch (op) { 3732 case Audit_equal: 3733 match = (ctxt->user == rule->au_ctxt.user); 3734 break; 3735 case Audit_not_equal: 3736 match = (ctxt->user != rule->au_ctxt.user); 3737 break; 3738 } 3739 break; 3740 case AUDIT_SUBJ_ROLE: 3741 case AUDIT_OBJ_ROLE: 3742 switch (op) { 3743 case Audit_equal: 3744 match = (ctxt->role == rule->au_ctxt.role); 3745 break; 3746 case Audit_not_equal: 3747 match = (ctxt->role != rule->au_ctxt.role); 3748 break; 3749 } 3750 break; 3751 case AUDIT_SUBJ_TYPE: 3752 case AUDIT_OBJ_TYPE: 3753 switch (op) { 3754 case Audit_equal: 3755 match = (ctxt->type == rule->au_ctxt.type); 3756 break; 3757 case Audit_not_equal: 3758 match = (ctxt->type != rule->au_ctxt.type); 3759 break; 3760 } 3761 break; 3762 case AUDIT_SUBJ_SEN: 3763 case AUDIT_SUBJ_CLR: 3764 case AUDIT_OBJ_LEV_LOW: 3765 case AUDIT_OBJ_LEV_HIGH: 3766 level = ((field == AUDIT_SUBJ_SEN || 3767 field == AUDIT_OBJ_LEV_LOW) ? 3768 &ctxt->range.level[0] : &ctxt->range.level[1]); 3769 switch (op) { 3770 case Audit_equal: 3771 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3772 level); 3773 break; 3774 case Audit_not_equal: 3775 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3776 level); 3777 break; 3778 case Audit_lt: 3779 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3780 level) && 3781 !mls_level_eq(&rule->au_ctxt.range.level[0], 3782 level)); 3783 break; 3784 case Audit_le: 3785 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3786 level); 3787 break; 3788 case Audit_gt: 3789 match = (mls_level_dom(level, 3790 &rule->au_ctxt.range.level[0]) && 3791 !mls_level_eq(level, 3792 &rule->au_ctxt.range.level[0])); 3793 break; 3794 case Audit_ge: 3795 match = mls_level_dom(level, 3796 &rule->au_ctxt.range.level[0]); 3797 break; 3798 } 3799 } 3800 3801 out: 3802 rcu_read_unlock(); 3803 return match; 3804 } 3805 3806 static int aurule_avc_callback(u32 event) 3807 { 3808 if (event == AVC_CALLBACK_RESET) 3809 return audit_update_lsm_rules(); 3810 return 0; 3811 } 3812 3813 static int __init aurule_init(void) 3814 { 3815 int err; 3816 3817 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3818 if (err) 3819 panic("avc_add_callback() failed, error %d\n", err); 3820 3821 return err; 3822 } 3823 __initcall(aurule_init); 3824 3825 #ifdef CONFIG_NETLABEL 3826 /** 3827 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3828 * @secattr: the NetLabel packet security attributes 3829 * @sid: the SELinux SID 3830 * 3831 * Description: 3832 * Attempt to cache the context in @ctx, which was derived from the packet in 3833 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3834 * already been initialized. 3835 * 3836 */ 3837 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3838 u32 sid) 3839 { 3840 u32 *sid_cache; 3841 3842 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3843 if (sid_cache == NULL) 3844 return; 3845 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3846 if (secattr->cache == NULL) { 3847 kfree(sid_cache); 3848 return; 3849 } 3850 3851 *sid_cache = sid; 3852 secattr->cache->free = kfree; 3853 secattr->cache->data = sid_cache; 3854 secattr->flags |= NETLBL_SECATTR_CACHE; 3855 } 3856 3857 /** 3858 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3859 * @state: SELinux state 3860 * @secattr: the NetLabel packet security attributes 3861 * @sid: the SELinux SID 3862 * 3863 * Description: 3864 * Convert the given NetLabel security attributes in @secattr into a 3865 * SELinux SID. If the @secattr field does not contain a full SELinux 3866 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3867 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3868 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3869 * conversion for future lookups. Returns zero on success, negative values on 3870 * failure. 3871 * 3872 */ 3873 int security_netlbl_secattr_to_sid(struct selinux_state *state, 3874 struct netlbl_lsm_secattr *secattr, 3875 u32 *sid) 3876 { 3877 struct selinux_policy *policy; 3878 struct policydb *policydb; 3879 struct sidtab *sidtab; 3880 int rc; 3881 struct context *ctx; 3882 struct context ctx_new; 3883 3884 if (!selinux_initialized(state)) { 3885 *sid = SECSID_NULL; 3886 return 0; 3887 } 3888 3889 retry: 3890 rc = 0; 3891 rcu_read_lock(); 3892 policy = rcu_dereference(state->policy); 3893 policydb = &policy->policydb; 3894 sidtab = policy->sidtab; 3895 3896 if (secattr->flags & NETLBL_SECATTR_CACHE) 3897 *sid = *(u32 *)secattr->cache->data; 3898 else if (secattr->flags & NETLBL_SECATTR_SECID) 3899 *sid = secattr->attr.secid; 3900 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3901 rc = -EIDRM; 3902 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3903 if (ctx == NULL) 3904 goto out; 3905 3906 context_init(&ctx_new); 3907 ctx_new.user = ctx->user; 3908 ctx_new.role = ctx->role; 3909 ctx_new.type = ctx->type; 3910 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3911 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3912 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3913 if (rc) 3914 goto out; 3915 } 3916 rc = -EIDRM; 3917 if (!mls_context_isvalid(policydb, &ctx_new)) { 3918 ebitmap_destroy(&ctx_new.range.level[0].cat); 3919 goto out; 3920 } 3921 3922 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3923 ebitmap_destroy(&ctx_new.range.level[0].cat); 3924 if (rc == -ESTALE) { 3925 rcu_read_unlock(); 3926 goto retry; 3927 } 3928 if (rc) 3929 goto out; 3930 3931 security_netlbl_cache_add(secattr, *sid); 3932 } else 3933 *sid = SECSID_NULL; 3934 3935 out: 3936 rcu_read_unlock(); 3937 return rc; 3938 } 3939 3940 /** 3941 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3942 * @state: SELinux state 3943 * @sid: the SELinux SID 3944 * @secattr: the NetLabel packet security attributes 3945 * 3946 * Description: 3947 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3948 * Returns zero on success, negative values on failure. 3949 * 3950 */ 3951 int security_netlbl_sid_to_secattr(struct selinux_state *state, 3952 u32 sid, struct netlbl_lsm_secattr *secattr) 3953 { 3954 struct selinux_policy *policy; 3955 struct policydb *policydb; 3956 int rc; 3957 struct context *ctx; 3958 3959 if (!selinux_initialized(state)) 3960 return 0; 3961 3962 rcu_read_lock(); 3963 policy = rcu_dereference(state->policy); 3964 policydb = &policy->policydb; 3965 3966 rc = -ENOENT; 3967 ctx = sidtab_search(policy->sidtab, sid); 3968 if (ctx == NULL) 3969 goto out; 3970 3971 rc = -ENOMEM; 3972 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3973 GFP_ATOMIC); 3974 if (secattr->domain == NULL) 3975 goto out; 3976 3977 secattr->attr.secid = sid; 3978 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3979 mls_export_netlbl_lvl(policydb, ctx, secattr); 3980 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3981 out: 3982 rcu_read_unlock(); 3983 return rc; 3984 } 3985 #endif /* CONFIG_NETLABEL */ 3986 3987 /** 3988 * __security_read_policy - read the policy. 3989 * @policy: SELinux policy 3990 * @data: binary policy data 3991 * @len: length of data in bytes 3992 * 3993 */ 3994 static int __security_read_policy(struct selinux_policy *policy, 3995 void *data, size_t *len) 3996 { 3997 int rc; 3998 struct policy_file fp; 3999 4000 fp.data = data; 4001 fp.len = *len; 4002 4003 rc = policydb_write(&policy->policydb, &fp); 4004 if (rc) 4005 return rc; 4006 4007 *len = (unsigned long)fp.data - (unsigned long)data; 4008 return 0; 4009 } 4010 4011 /** 4012 * security_read_policy - read the policy. 4013 * @state: selinux_state 4014 * @data: binary policy data 4015 * @len: length of data in bytes 4016 * 4017 */ 4018 int security_read_policy(struct selinux_state *state, 4019 void **data, size_t *len) 4020 { 4021 struct selinux_policy *policy; 4022 4023 policy = rcu_dereference_protected( 4024 state->policy, lockdep_is_held(&state->policy_mutex)); 4025 if (!policy) 4026 return -EINVAL; 4027 4028 *len = policy->policydb.len; 4029 *data = vmalloc_user(*len); 4030 if (!*data) 4031 return -ENOMEM; 4032 4033 return __security_read_policy(policy, *data, len); 4034 } 4035 4036 /** 4037 * security_read_state_kernel - read the policy. 4038 * @state: selinux_state 4039 * @data: binary policy data 4040 * @len: length of data in bytes 4041 * 4042 * Allocates kernel memory for reading SELinux policy. 4043 * This function is for internal use only and should not 4044 * be used for returning data to user space. 4045 * 4046 * This function must be called with policy_mutex held. 4047 */ 4048 int security_read_state_kernel(struct selinux_state *state, 4049 void **data, size_t *len) 4050 { 4051 struct selinux_policy *policy; 4052 4053 policy = rcu_dereference_protected( 4054 state->policy, lockdep_is_held(&state->policy_mutex)); 4055 if (!policy) 4056 return -EINVAL; 4057 4058 *len = policy->policydb.len; 4059 *data = vmalloc(*len); 4060 if (!*data) 4061 return -ENOMEM; 4062 4063 return __security_read_policy(policy, *data, len); 4064 } 4065