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