1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Implementation of the security services. 4 * 5 * Authors : Stephen Smalley, <sds@tycho.nsa.gov> 6 * James Morris <jmorris@redhat.com> 7 * 8 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> 9 * 10 * Support for enhanced MLS infrastructure. 11 * Support for context based audit filters. 12 * 13 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> 14 * 15 * Added conditional policy language extensions 16 * 17 * Updated: Hewlett-Packard <paul@paul-moore.com> 18 * 19 * Added support for NetLabel 20 * Added support for the policy capability bitmap 21 * 22 * Updated: Chad Sellers <csellers@tresys.com> 23 * 24 * Added validation of kernel classes and permissions 25 * 26 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> 27 * 28 * Added support for bounds domain and audit messaged on masked permissions 29 * 30 * Updated: Guido Trentalancia <guido@trentalancia.com> 31 * 32 * Added support for runtime switching of the policy type 33 * 34 * Copyright (C) 2008, 2009 NEC Corporation 35 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. 36 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. 37 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC 38 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> 39 */ 40 #include <linux/kernel.h> 41 #include <linux/slab.h> 42 #include <linux/string.h> 43 #include <linux/spinlock.h> 44 #include <linux/rcupdate.h> 45 #include <linux/errno.h> 46 #include <linux/in.h> 47 #include <linux/sched.h> 48 #include <linux/audit.h> 49 #include <linux/vmalloc.h> 50 #include <linux/lsm_hooks.h> 51 #include <net/netlabel.h> 52 53 #include "flask.h" 54 #include "avc.h" 55 #include "avc_ss.h" 56 #include "security.h" 57 #include "context.h" 58 #include "policydb.h" 59 #include "sidtab.h" 60 #include "services.h" 61 #include "conditional.h" 62 #include "mls.h" 63 #include "objsec.h" 64 #include "netlabel.h" 65 #include "xfrm.h" 66 #include "ebitmap.h" 67 #include "audit.h" 68 #include "policycap_names.h" 69 #include "ima.h" 70 71 struct selinux_policy_convert_data { 72 struct convert_context_args args; 73 struct sidtab_convert_params sidtab_params; 74 }; 75 76 /* Forward declaration. */ 77 static int context_struct_to_string(struct policydb *policydb, 78 struct context *context, 79 char **scontext, 80 u32 *scontext_len); 81 82 static int sidtab_entry_to_string(struct policydb *policydb, 83 struct sidtab *sidtab, 84 struct sidtab_entry *entry, 85 char **scontext, 86 u32 *scontext_len); 87 88 static void context_struct_compute_av(struct policydb *policydb, 89 struct context *scontext, 90 struct context *tcontext, 91 u16 tclass, 92 struct av_decision *avd, 93 struct extended_perms *xperms); 94 95 static int selinux_set_mapping(struct policydb *pol, 96 const struct security_class_mapping *map, 97 struct selinux_map *out_map) 98 { 99 u16 i, j; 100 unsigned k; 101 bool print_unknown_handle = false; 102 103 /* Find number of classes in the input mapping */ 104 if (!map) 105 return -EINVAL; 106 i = 0; 107 while (map[i].name) 108 i++; 109 110 /* Allocate space for the class records, plus one for class zero */ 111 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 112 if (!out_map->mapping) 113 return -ENOMEM; 114 115 /* Store the raw class and permission values */ 116 j = 0; 117 while (map[j].name) { 118 const struct security_class_mapping *p_in = map + (j++); 119 struct selinux_mapping *p_out = out_map->mapping + j; 120 121 /* An empty class string skips ahead */ 122 if (!strcmp(p_in->name, "")) { 123 p_out->num_perms = 0; 124 continue; 125 } 126 127 p_out->value = string_to_security_class(pol, p_in->name); 128 if (!p_out->value) { 129 pr_info("SELinux: Class %s not defined in policy.\n", 130 p_in->name); 131 if (pol->reject_unknown) 132 goto err; 133 p_out->num_perms = 0; 134 print_unknown_handle = true; 135 continue; 136 } 137 138 k = 0; 139 while (p_in->perms[k]) { 140 /* An empty permission string skips ahead */ 141 if (!*p_in->perms[k]) { 142 k++; 143 continue; 144 } 145 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 146 p_in->perms[k]); 147 if (!p_out->perms[k]) { 148 pr_info("SELinux: Permission %s in class %s not defined in policy.\n", 149 p_in->perms[k], p_in->name); 150 if (pol->reject_unknown) 151 goto err; 152 print_unknown_handle = true; 153 } 154 155 k++; 156 } 157 p_out->num_perms = k; 158 } 159 160 if (print_unknown_handle) 161 pr_info("SELinux: the above unknown classes and permissions will be %s\n", 162 pol->allow_unknown ? "allowed" : "denied"); 163 164 out_map->size = i; 165 return 0; 166 err: 167 kfree(out_map->mapping); 168 out_map->mapping = NULL; 169 return -EINVAL; 170 } 171 172 /* 173 * Get real, policy values from mapped values 174 */ 175 176 static u16 unmap_class(struct selinux_map *map, u16 tclass) 177 { 178 if (tclass < map->size) 179 return map->mapping[tclass].value; 180 181 return tclass; 182 } 183 184 /* 185 * Get kernel value for class from its policy value 186 */ 187 static u16 map_class(struct selinux_map *map, u16 pol_value) 188 { 189 u16 i; 190 191 for (i = 1; i < map->size; i++) { 192 if (map->mapping[i].value == pol_value) 193 return i; 194 } 195 196 return SECCLASS_NULL; 197 } 198 199 static void map_decision(struct selinux_map *map, 200 u16 tclass, struct av_decision *avd, 201 int allow_unknown) 202 { 203 if (tclass < map->size) { 204 struct selinux_mapping *mapping = &map->mapping[tclass]; 205 unsigned int i, n = mapping->num_perms; 206 u32 result; 207 208 for (i = 0, result = 0; i < n; i++) { 209 if (avd->allowed & mapping->perms[i]) 210 result |= 1<<i; 211 if (allow_unknown && !mapping->perms[i]) 212 result |= 1<<i; 213 } 214 avd->allowed = result; 215 216 for (i = 0, result = 0; i < n; i++) 217 if (avd->auditallow & mapping->perms[i]) 218 result |= 1<<i; 219 avd->auditallow = result; 220 221 for (i = 0, result = 0; i < n; i++) { 222 if (avd->auditdeny & mapping->perms[i]) 223 result |= 1<<i; 224 if (!allow_unknown && !mapping->perms[i]) 225 result |= 1<<i; 226 } 227 /* 228 * In case the kernel has a bug and requests a permission 229 * between num_perms and the maximum permission number, we 230 * should audit that denial 231 */ 232 for (; i < (sizeof(u32)*8); i++) 233 result |= 1<<i; 234 avd->auditdeny = result; 235 } 236 } 237 238 int security_mls_enabled(struct selinux_state *state) 239 { 240 int mls_enabled; 241 struct selinux_policy *policy; 242 243 if (!selinux_initialized(state)) 244 return 0; 245 246 rcu_read_lock(); 247 policy = rcu_dereference(state->policy); 248 mls_enabled = policy->policydb.mls_enabled; 249 rcu_read_unlock(); 250 return mls_enabled; 251 } 252 253 /* 254 * Return the boolean value of a constraint expression 255 * when it is applied to the specified source and target 256 * security contexts. 257 * 258 * xcontext is a special beast... It is used by the validatetrans rules 259 * only. For these rules, scontext is the context before the transition, 260 * tcontext is the context after the transition, and xcontext is the context 261 * of the process performing the transition. All other callers of 262 * constraint_expr_eval should pass in NULL for xcontext. 263 */ 264 static int constraint_expr_eval(struct policydb *policydb, 265 struct context *scontext, 266 struct context *tcontext, 267 struct context *xcontext, 268 struct constraint_expr *cexpr) 269 { 270 u32 val1, val2; 271 struct context *c; 272 struct role_datum *r1, *r2; 273 struct mls_level *l1, *l2; 274 struct constraint_expr *e; 275 int s[CEXPR_MAXDEPTH]; 276 int sp = -1; 277 278 for (e = cexpr; e; e = e->next) { 279 switch (e->expr_type) { 280 case CEXPR_NOT: 281 BUG_ON(sp < 0); 282 s[sp] = !s[sp]; 283 break; 284 case CEXPR_AND: 285 BUG_ON(sp < 1); 286 sp--; 287 s[sp] &= s[sp + 1]; 288 break; 289 case CEXPR_OR: 290 BUG_ON(sp < 1); 291 sp--; 292 s[sp] |= s[sp + 1]; 293 break; 294 case CEXPR_ATTR: 295 if (sp == (CEXPR_MAXDEPTH - 1)) 296 return 0; 297 switch (e->attr) { 298 case CEXPR_USER: 299 val1 = scontext->user; 300 val2 = tcontext->user; 301 break; 302 case CEXPR_TYPE: 303 val1 = scontext->type; 304 val2 = tcontext->type; 305 break; 306 case CEXPR_ROLE: 307 val1 = scontext->role; 308 val2 = tcontext->role; 309 r1 = policydb->role_val_to_struct[val1 - 1]; 310 r2 = policydb->role_val_to_struct[val2 - 1]; 311 switch (e->op) { 312 case CEXPR_DOM: 313 s[++sp] = ebitmap_get_bit(&r1->dominates, 314 val2 - 1); 315 continue; 316 case CEXPR_DOMBY: 317 s[++sp] = ebitmap_get_bit(&r2->dominates, 318 val1 - 1); 319 continue; 320 case CEXPR_INCOMP: 321 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 322 val2 - 1) && 323 !ebitmap_get_bit(&r2->dominates, 324 val1 - 1)); 325 continue; 326 default: 327 break; 328 } 329 break; 330 case CEXPR_L1L2: 331 l1 = &(scontext->range.level[0]); 332 l2 = &(tcontext->range.level[0]); 333 goto mls_ops; 334 case CEXPR_L1H2: 335 l1 = &(scontext->range.level[0]); 336 l2 = &(tcontext->range.level[1]); 337 goto mls_ops; 338 case CEXPR_H1L2: 339 l1 = &(scontext->range.level[1]); 340 l2 = &(tcontext->range.level[0]); 341 goto mls_ops; 342 case CEXPR_H1H2: 343 l1 = &(scontext->range.level[1]); 344 l2 = &(tcontext->range.level[1]); 345 goto mls_ops; 346 case CEXPR_L1H1: 347 l1 = &(scontext->range.level[0]); 348 l2 = &(scontext->range.level[1]); 349 goto mls_ops; 350 case CEXPR_L2H2: 351 l1 = &(tcontext->range.level[0]); 352 l2 = &(tcontext->range.level[1]); 353 goto mls_ops; 354 mls_ops: 355 switch (e->op) { 356 case CEXPR_EQ: 357 s[++sp] = mls_level_eq(l1, l2); 358 continue; 359 case CEXPR_NEQ: 360 s[++sp] = !mls_level_eq(l1, l2); 361 continue; 362 case CEXPR_DOM: 363 s[++sp] = mls_level_dom(l1, l2); 364 continue; 365 case CEXPR_DOMBY: 366 s[++sp] = mls_level_dom(l2, l1); 367 continue; 368 case CEXPR_INCOMP: 369 s[++sp] = mls_level_incomp(l2, l1); 370 continue; 371 default: 372 BUG(); 373 return 0; 374 } 375 break; 376 default: 377 BUG(); 378 return 0; 379 } 380 381 switch (e->op) { 382 case CEXPR_EQ: 383 s[++sp] = (val1 == val2); 384 break; 385 case CEXPR_NEQ: 386 s[++sp] = (val1 != val2); 387 break; 388 default: 389 BUG(); 390 return 0; 391 } 392 break; 393 case CEXPR_NAMES: 394 if (sp == (CEXPR_MAXDEPTH-1)) 395 return 0; 396 c = scontext; 397 if (e->attr & CEXPR_TARGET) 398 c = tcontext; 399 else if (e->attr & CEXPR_XTARGET) { 400 c = xcontext; 401 if (!c) { 402 BUG(); 403 return 0; 404 } 405 } 406 if (e->attr & CEXPR_USER) 407 val1 = c->user; 408 else if (e->attr & CEXPR_ROLE) 409 val1 = c->role; 410 else if (e->attr & CEXPR_TYPE) 411 val1 = c->type; 412 else { 413 BUG(); 414 return 0; 415 } 416 417 switch (e->op) { 418 case CEXPR_EQ: 419 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 420 break; 421 case CEXPR_NEQ: 422 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 423 break; 424 default: 425 BUG(); 426 return 0; 427 } 428 break; 429 default: 430 BUG(); 431 return 0; 432 } 433 } 434 435 BUG_ON(sp != 0); 436 return s[0]; 437 } 438 439 /* 440 * security_dump_masked_av - dumps masked permissions during 441 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 442 */ 443 static int dump_masked_av_helper(void *k, void *d, void *args) 444 { 445 struct perm_datum *pdatum = d; 446 char **permission_names = args; 447 448 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 449 450 permission_names[pdatum->value - 1] = (char *)k; 451 452 return 0; 453 } 454 455 static void security_dump_masked_av(struct policydb *policydb, 456 struct context *scontext, 457 struct context *tcontext, 458 u16 tclass, 459 u32 permissions, 460 const char *reason) 461 { 462 struct common_datum *common_dat; 463 struct class_datum *tclass_dat; 464 struct audit_buffer *ab; 465 char *tclass_name; 466 char *scontext_name = NULL; 467 char *tcontext_name = NULL; 468 char *permission_names[32]; 469 int index; 470 u32 length; 471 bool need_comma = false; 472 473 if (!permissions) 474 return; 475 476 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); 477 tclass_dat = policydb->class_val_to_struct[tclass - 1]; 478 common_dat = tclass_dat->comdatum; 479 480 /* init permission_names */ 481 if (common_dat && 482 hashtab_map(&common_dat->permissions.table, 483 dump_masked_av_helper, permission_names) < 0) 484 goto out; 485 486 if (hashtab_map(&tclass_dat->permissions.table, 487 dump_masked_av_helper, permission_names) < 0) 488 goto out; 489 490 /* get scontext/tcontext in text form */ 491 if (context_struct_to_string(policydb, scontext, 492 &scontext_name, &length) < 0) 493 goto out; 494 495 if (context_struct_to_string(policydb, tcontext, 496 &tcontext_name, &length) < 0) 497 goto out; 498 499 /* audit a message */ 500 ab = audit_log_start(audit_context(), 501 GFP_ATOMIC, AUDIT_SELINUX_ERR); 502 if (!ab) 503 goto out; 504 505 audit_log_format(ab, "op=security_compute_av reason=%s " 506 "scontext=%s tcontext=%s tclass=%s perms=", 507 reason, scontext_name, tcontext_name, tclass_name); 508 509 for (index = 0; index < 32; index++) { 510 u32 mask = (1 << index); 511 512 if ((mask & permissions) == 0) 513 continue; 514 515 audit_log_format(ab, "%s%s", 516 need_comma ? "," : "", 517 permission_names[index] 518 ? permission_names[index] : "????"); 519 need_comma = true; 520 } 521 audit_log_end(ab); 522 out: 523 /* release scontext/tcontext */ 524 kfree(tcontext_name); 525 kfree(scontext_name); 526 } 527 528 /* 529 * security_boundary_permission - drops violated permissions 530 * on boundary constraint. 531 */ 532 static void type_attribute_bounds_av(struct policydb *policydb, 533 struct context *scontext, 534 struct context *tcontext, 535 u16 tclass, 536 struct av_decision *avd) 537 { 538 struct context lo_scontext; 539 struct context lo_tcontext, *tcontextp = tcontext; 540 struct av_decision lo_avd; 541 struct type_datum *source; 542 struct type_datum *target; 543 u32 masked = 0; 544 545 source = policydb->type_val_to_struct[scontext->type - 1]; 546 BUG_ON(!source); 547 548 if (!source->bounds) 549 return; 550 551 target = policydb->type_val_to_struct[tcontext->type - 1]; 552 BUG_ON(!target); 553 554 memset(&lo_avd, 0, sizeof(lo_avd)); 555 556 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 557 lo_scontext.type = source->bounds; 558 559 if (target->bounds) { 560 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 561 lo_tcontext.type = target->bounds; 562 tcontextp = &lo_tcontext; 563 } 564 565 context_struct_compute_av(policydb, &lo_scontext, 566 tcontextp, 567 tclass, 568 &lo_avd, 569 NULL); 570 571 masked = ~lo_avd.allowed & avd->allowed; 572 573 if (likely(!masked)) 574 return; /* no masked permission */ 575 576 /* mask violated permissions */ 577 avd->allowed &= ~masked; 578 579 /* audit masked permissions */ 580 security_dump_masked_av(policydb, scontext, tcontext, 581 tclass, masked, "bounds"); 582 } 583 584 /* 585 * flag which drivers have permissions 586 * only looking for ioctl based extended permssions 587 */ 588 void services_compute_xperms_drivers( 589 struct extended_perms *xperms, 590 struct avtab_node *node) 591 { 592 unsigned int i; 593 594 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 595 /* if one or more driver has all permissions allowed */ 596 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 597 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 598 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 599 /* if allowing permissions within a driver */ 600 security_xperm_set(xperms->drivers.p, 601 node->datum.u.xperms->driver); 602 } 603 604 xperms->len = 1; 605 } 606 607 /* 608 * Compute access vectors and extended permissions based on a context 609 * structure pair for the permissions in a particular class. 610 */ 611 static void context_struct_compute_av(struct policydb *policydb, 612 struct context *scontext, 613 struct context *tcontext, 614 u16 tclass, 615 struct av_decision *avd, 616 struct extended_perms *xperms) 617 { 618 struct constraint_node *constraint; 619 struct role_allow *ra; 620 struct avtab_key avkey; 621 struct avtab_node *node; 622 struct class_datum *tclass_datum; 623 struct ebitmap *sattr, *tattr; 624 struct ebitmap_node *snode, *tnode; 625 unsigned int i, j; 626 627 avd->allowed = 0; 628 avd->auditallow = 0; 629 avd->auditdeny = 0xffffffff; 630 if (xperms) { 631 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 632 xperms->len = 0; 633 } 634 635 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 636 if (printk_ratelimit()) 637 pr_warn("SELinux: Invalid class %hu\n", tclass); 638 return; 639 } 640 641 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 642 643 /* 644 * If a specific type enforcement rule was defined for 645 * this permission check, then use it. 646 */ 647 avkey.target_class = tclass; 648 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 649 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 650 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 651 ebitmap_for_each_positive_bit(sattr, snode, i) { 652 ebitmap_for_each_positive_bit(tattr, tnode, j) { 653 avkey.source_type = i + 1; 654 avkey.target_type = j + 1; 655 for (node = avtab_search_node(&policydb->te_avtab, 656 &avkey); 657 node; 658 node = avtab_search_node_next(node, avkey.specified)) { 659 if (node->key.specified == AVTAB_ALLOWED) 660 avd->allowed |= node->datum.u.data; 661 else if (node->key.specified == AVTAB_AUDITALLOW) 662 avd->auditallow |= node->datum.u.data; 663 else if (node->key.specified == AVTAB_AUDITDENY) 664 avd->auditdeny &= node->datum.u.data; 665 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 666 services_compute_xperms_drivers(xperms, node); 667 } 668 669 /* Check conditional av table for additional permissions */ 670 cond_compute_av(&policydb->te_cond_avtab, &avkey, 671 avd, xperms); 672 673 } 674 } 675 676 /* 677 * Remove any permissions prohibited by a constraint (this includes 678 * the MLS policy). 679 */ 680 constraint = tclass_datum->constraints; 681 while (constraint) { 682 if ((constraint->permissions & (avd->allowed)) && 683 !constraint_expr_eval(policydb, scontext, tcontext, NULL, 684 constraint->expr)) { 685 avd->allowed &= ~(constraint->permissions); 686 } 687 constraint = constraint->next; 688 } 689 690 /* 691 * If checking process transition permission and the 692 * role is changing, then check the (current_role, new_role) 693 * pair. 694 */ 695 if (tclass == policydb->process_class && 696 (avd->allowed & policydb->process_trans_perms) && 697 scontext->role != tcontext->role) { 698 for (ra = policydb->role_allow; ra; ra = ra->next) { 699 if (scontext->role == ra->role && 700 tcontext->role == ra->new_role) 701 break; 702 } 703 if (!ra) 704 avd->allowed &= ~policydb->process_trans_perms; 705 } 706 707 /* 708 * If the given source and target types have boundary 709 * constraint, lazy checks have to mask any violated 710 * permission and notice it to userspace via audit. 711 */ 712 type_attribute_bounds_av(policydb, scontext, tcontext, 713 tclass, avd); 714 } 715 716 static int security_validtrans_handle_fail(struct selinux_state *state, 717 struct selinux_policy *policy, 718 struct sidtab_entry *oentry, 719 struct sidtab_entry *nentry, 720 struct sidtab_entry *tentry, 721 u16 tclass) 722 { 723 struct policydb *p = &policy->policydb; 724 struct sidtab *sidtab = policy->sidtab; 725 char *o = NULL, *n = NULL, *t = NULL; 726 u32 olen, nlen, tlen; 727 728 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) 729 goto out; 730 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) 731 goto out; 732 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) 733 goto out; 734 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 735 "op=security_validate_transition seresult=denied" 736 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 737 o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); 738 out: 739 kfree(o); 740 kfree(n); 741 kfree(t); 742 743 if (!enforcing_enabled(state)) 744 return 0; 745 return -EPERM; 746 } 747 748 static int security_compute_validatetrans(struct selinux_state *state, 749 u32 oldsid, u32 newsid, u32 tasksid, 750 u16 orig_tclass, bool user) 751 { 752 struct selinux_policy *policy; 753 struct policydb *policydb; 754 struct sidtab *sidtab; 755 struct sidtab_entry *oentry; 756 struct sidtab_entry *nentry; 757 struct sidtab_entry *tentry; 758 struct class_datum *tclass_datum; 759 struct constraint_node *constraint; 760 u16 tclass; 761 int rc = 0; 762 763 764 if (!selinux_initialized(state)) 765 return 0; 766 767 rcu_read_lock(); 768 769 policy = rcu_dereference(state->policy); 770 policydb = &policy->policydb; 771 sidtab = policy->sidtab; 772 773 if (!user) 774 tclass = unmap_class(&policy->map, orig_tclass); 775 else 776 tclass = orig_tclass; 777 778 if (!tclass || tclass > policydb->p_classes.nprim) { 779 rc = -EINVAL; 780 goto out; 781 } 782 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 783 784 oentry = sidtab_search_entry(sidtab, oldsid); 785 if (!oentry) { 786 pr_err("SELinux: %s: unrecognized SID %d\n", 787 __func__, oldsid); 788 rc = -EINVAL; 789 goto out; 790 } 791 792 nentry = sidtab_search_entry(sidtab, newsid); 793 if (!nentry) { 794 pr_err("SELinux: %s: unrecognized SID %d\n", 795 __func__, newsid); 796 rc = -EINVAL; 797 goto out; 798 } 799 800 tentry = sidtab_search_entry(sidtab, tasksid); 801 if (!tentry) { 802 pr_err("SELinux: %s: unrecognized SID %d\n", 803 __func__, tasksid); 804 rc = -EINVAL; 805 goto out; 806 } 807 808 constraint = tclass_datum->validatetrans; 809 while (constraint) { 810 if (!constraint_expr_eval(policydb, &oentry->context, 811 &nentry->context, &tentry->context, 812 constraint->expr)) { 813 if (user) 814 rc = -EPERM; 815 else 816 rc = security_validtrans_handle_fail(state, 817 policy, 818 oentry, 819 nentry, 820 tentry, 821 tclass); 822 goto out; 823 } 824 constraint = constraint->next; 825 } 826 827 out: 828 rcu_read_unlock(); 829 return rc; 830 } 831 832 int security_validate_transition_user(struct selinux_state *state, 833 u32 oldsid, u32 newsid, u32 tasksid, 834 u16 tclass) 835 { 836 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 837 tclass, true); 838 } 839 840 int security_validate_transition(struct selinux_state *state, 841 u32 oldsid, u32 newsid, u32 tasksid, 842 u16 orig_tclass) 843 { 844 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 845 orig_tclass, false); 846 } 847 848 /* 849 * security_bounded_transition - check whether the given 850 * transition is directed to bounded, or not. 851 * It returns 0, if @newsid is bounded by @oldsid. 852 * Otherwise, it returns error code. 853 * 854 * @state: SELinux state 855 * @oldsid : current security identifier 856 * @newsid : destinated security identifier 857 */ 858 int security_bounded_transition(struct selinux_state *state, 859 u32 old_sid, u32 new_sid) 860 { 861 struct selinux_policy *policy; 862 struct policydb *policydb; 863 struct sidtab *sidtab; 864 struct sidtab_entry *old_entry, *new_entry; 865 struct type_datum *type; 866 int index; 867 int rc; 868 869 if (!selinux_initialized(state)) 870 return 0; 871 872 rcu_read_lock(); 873 policy = rcu_dereference(state->policy); 874 policydb = &policy->policydb; 875 sidtab = policy->sidtab; 876 877 rc = -EINVAL; 878 old_entry = sidtab_search_entry(sidtab, old_sid); 879 if (!old_entry) { 880 pr_err("SELinux: %s: unrecognized SID %u\n", 881 __func__, old_sid); 882 goto out; 883 } 884 885 rc = -EINVAL; 886 new_entry = sidtab_search_entry(sidtab, new_sid); 887 if (!new_entry) { 888 pr_err("SELinux: %s: unrecognized SID %u\n", 889 __func__, new_sid); 890 goto out; 891 } 892 893 rc = 0; 894 /* type/domain unchanged */ 895 if (old_entry->context.type == new_entry->context.type) 896 goto out; 897 898 index = new_entry->context.type; 899 while (true) { 900 type = policydb->type_val_to_struct[index - 1]; 901 BUG_ON(!type); 902 903 /* not bounded anymore */ 904 rc = -EPERM; 905 if (!type->bounds) 906 break; 907 908 /* @newsid is bounded by @oldsid */ 909 rc = 0; 910 if (type->bounds == old_entry->context.type) 911 break; 912 913 index = type->bounds; 914 } 915 916 if (rc) { 917 char *old_name = NULL; 918 char *new_name = NULL; 919 u32 length; 920 921 if (!sidtab_entry_to_string(policydb, sidtab, old_entry, 922 &old_name, &length) && 923 !sidtab_entry_to_string(policydb, sidtab, new_entry, 924 &new_name, &length)) { 925 audit_log(audit_context(), 926 GFP_ATOMIC, AUDIT_SELINUX_ERR, 927 "op=security_bounded_transition " 928 "seresult=denied " 929 "oldcontext=%s newcontext=%s", 930 old_name, new_name); 931 } 932 kfree(new_name); 933 kfree(old_name); 934 } 935 out: 936 rcu_read_unlock(); 937 938 return rc; 939 } 940 941 static void avd_init(struct selinux_policy *policy, struct av_decision *avd) 942 { 943 avd->allowed = 0; 944 avd->auditallow = 0; 945 avd->auditdeny = 0xffffffff; 946 if (policy) 947 avd->seqno = policy->latest_granting; 948 else 949 avd->seqno = 0; 950 avd->flags = 0; 951 } 952 953 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 954 struct avtab_node *node) 955 { 956 unsigned int i; 957 958 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 959 if (xpermd->driver != node->datum.u.xperms->driver) 960 return; 961 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 962 if (!security_xperm_test(node->datum.u.xperms->perms.p, 963 xpermd->driver)) 964 return; 965 } else { 966 BUG(); 967 } 968 969 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 970 xpermd->used |= XPERMS_ALLOWED; 971 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 972 memset(xpermd->allowed->p, 0xff, 973 sizeof(xpermd->allowed->p)); 974 } 975 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 976 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 977 xpermd->allowed->p[i] |= 978 node->datum.u.xperms->perms.p[i]; 979 } 980 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 981 xpermd->used |= XPERMS_AUDITALLOW; 982 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 983 memset(xpermd->auditallow->p, 0xff, 984 sizeof(xpermd->auditallow->p)); 985 } 986 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 987 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 988 xpermd->auditallow->p[i] |= 989 node->datum.u.xperms->perms.p[i]; 990 } 991 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 992 xpermd->used |= XPERMS_DONTAUDIT; 993 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 994 memset(xpermd->dontaudit->p, 0xff, 995 sizeof(xpermd->dontaudit->p)); 996 } 997 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 998 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 999 xpermd->dontaudit->p[i] |= 1000 node->datum.u.xperms->perms.p[i]; 1001 } 1002 } else { 1003 BUG(); 1004 } 1005 } 1006 1007 void security_compute_xperms_decision(struct selinux_state *state, 1008 u32 ssid, 1009 u32 tsid, 1010 u16 orig_tclass, 1011 u8 driver, 1012 struct extended_perms_decision *xpermd) 1013 { 1014 struct selinux_policy *policy; 1015 struct policydb *policydb; 1016 struct sidtab *sidtab; 1017 u16 tclass; 1018 struct context *scontext, *tcontext; 1019 struct avtab_key avkey; 1020 struct avtab_node *node; 1021 struct ebitmap *sattr, *tattr; 1022 struct ebitmap_node *snode, *tnode; 1023 unsigned int i, j; 1024 1025 xpermd->driver = driver; 1026 xpermd->used = 0; 1027 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1028 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1029 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1030 1031 rcu_read_lock(); 1032 if (!selinux_initialized(state)) 1033 goto allow; 1034 1035 policy = rcu_dereference(state->policy); 1036 policydb = &policy->policydb; 1037 sidtab = policy->sidtab; 1038 1039 scontext = sidtab_search(sidtab, ssid); 1040 if (!scontext) { 1041 pr_err("SELinux: %s: unrecognized SID %d\n", 1042 __func__, ssid); 1043 goto out; 1044 } 1045 1046 tcontext = sidtab_search(sidtab, tsid); 1047 if (!tcontext) { 1048 pr_err("SELinux: %s: unrecognized SID %d\n", 1049 __func__, tsid); 1050 goto out; 1051 } 1052 1053 tclass = unmap_class(&policy->map, orig_tclass); 1054 if (unlikely(orig_tclass && !tclass)) { 1055 if (policydb->allow_unknown) 1056 goto allow; 1057 goto out; 1058 } 1059 1060 1061 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1062 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1063 goto out; 1064 } 1065 1066 avkey.target_class = tclass; 1067 avkey.specified = AVTAB_XPERMS; 1068 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 1069 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 1070 ebitmap_for_each_positive_bit(sattr, snode, i) { 1071 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1072 avkey.source_type = i + 1; 1073 avkey.target_type = j + 1; 1074 for (node = avtab_search_node(&policydb->te_avtab, 1075 &avkey); 1076 node; 1077 node = avtab_search_node_next(node, avkey.specified)) 1078 services_compute_xperms_decision(xpermd, node); 1079 1080 cond_compute_xperms(&policydb->te_cond_avtab, 1081 &avkey, xpermd); 1082 } 1083 } 1084 out: 1085 rcu_read_unlock(); 1086 return; 1087 allow: 1088 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1089 goto out; 1090 } 1091 1092 /** 1093 * security_compute_av - Compute access vector decisions. 1094 * @state: SELinux state 1095 * @ssid: source security identifier 1096 * @tsid: target security identifier 1097 * @orig_tclass: target security class 1098 * @avd: access vector decisions 1099 * @xperms: extended permissions 1100 * 1101 * Compute a set of access vector decisions based on the 1102 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1103 */ 1104 void security_compute_av(struct selinux_state *state, 1105 u32 ssid, 1106 u32 tsid, 1107 u16 orig_tclass, 1108 struct av_decision *avd, 1109 struct extended_perms *xperms) 1110 { 1111 struct selinux_policy *policy; 1112 struct policydb *policydb; 1113 struct sidtab *sidtab; 1114 u16 tclass; 1115 struct context *scontext = NULL, *tcontext = NULL; 1116 1117 rcu_read_lock(); 1118 policy = rcu_dereference(state->policy); 1119 avd_init(policy, avd); 1120 xperms->len = 0; 1121 if (!selinux_initialized(state)) 1122 goto allow; 1123 1124 policydb = &policy->policydb; 1125 sidtab = policy->sidtab; 1126 1127 scontext = sidtab_search(sidtab, ssid); 1128 if (!scontext) { 1129 pr_err("SELinux: %s: unrecognized SID %d\n", 1130 __func__, ssid); 1131 goto out; 1132 } 1133 1134 /* permissive domain? */ 1135 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1136 avd->flags |= AVD_FLAGS_PERMISSIVE; 1137 1138 tcontext = sidtab_search(sidtab, tsid); 1139 if (!tcontext) { 1140 pr_err("SELinux: %s: unrecognized SID %d\n", 1141 __func__, tsid); 1142 goto out; 1143 } 1144 1145 tclass = unmap_class(&policy->map, orig_tclass); 1146 if (unlikely(orig_tclass && !tclass)) { 1147 if (policydb->allow_unknown) 1148 goto allow; 1149 goto out; 1150 } 1151 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1152 xperms); 1153 map_decision(&policy->map, orig_tclass, avd, 1154 policydb->allow_unknown); 1155 out: 1156 rcu_read_unlock(); 1157 return; 1158 allow: 1159 avd->allowed = 0xffffffff; 1160 goto out; 1161 } 1162 1163 void security_compute_av_user(struct selinux_state *state, 1164 u32 ssid, 1165 u32 tsid, 1166 u16 tclass, 1167 struct av_decision *avd) 1168 { 1169 struct selinux_policy *policy; 1170 struct policydb *policydb; 1171 struct sidtab *sidtab; 1172 struct context *scontext = NULL, *tcontext = NULL; 1173 1174 rcu_read_lock(); 1175 policy = rcu_dereference(state->policy); 1176 avd_init(policy, avd); 1177 if (!selinux_initialized(state)) 1178 goto allow; 1179 1180 policydb = &policy->policydb; 1181 sidtab = policy->sidtab; 1182 1183 scontext = sidtab_search(sidtab, ssid); 1184 if (!scontext) { 1185 pr_err("SELinux: %s: unrecognized SID %d\n", 1186 __func__, ssid); 1187 goto out; 1188 } 1189 1190 /* permissive domain? */ 1191 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1192 avd->flags |= AVD_FLAGS_PERMISSIVE; 1193 1194 tcontext = sidtab_search(sidtab, tsid); 1195 if (!tcontext) { 1196 pr_err("SELinux: %s: unrecognized SID %d\n", 1197 __func__, tsid); 1198 goto out; 1199 } 1200 1201 if (unlikely(!tclass)) { 1202 if (policydb->allow_unknown) 1203 goto allow; 1204 goto out; 1205 } 1206 1207 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1208 NULL); 1209 out: 1210 rcu_read_unlock(); 1211 return; 1212 allow: 1213 avd->allowed = 0xffffffff; 1214 goto out; 1215 } 1216 1217 /* 1218 * Write the security context string representation of 1219 * the context structure `context' into a dynamically 1220 * allocated string of the correct size. Set `*scontext' 1221 * to point to this string and set `*scontext_len' to 1222 * the length of the string. 1223 */ 1224 static int context_struct_to_string(struct policydb *p, 1225 struct context *context, 1226 char **scontext, u32 *scontext_len) 1227 { 1228 char *scontextp; 1229 1230 if (scontext) 1231 *scontext = NULL; 1232 *scontext_len = 0; 1233 1234 if (context->len) { 1235 *scontext_len = context->len; 1236 if (scontext) { 1237 *scontext = kstrdup(context->str, GFP_ATOMIC); 1238 if (!(*scontext)) 1239 return -ENOMEM; 1240 } 1241 return 0; 1242 } 1243 1244 /* Compute the size of the context. */ 1245 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1246 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1247 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1248 *scontext_len += mls_compute_context_len(p, context); 1249 1250 if (!scontext) 1251 return 0; 1252 1253 /* Allocate space for the context; caller must free this space. */ 1254 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1255 if (!scontextp) 1256 return -ENOMEM; 1257 *scontext = scontextp; 1258 1259 /* 1260 * Copy the user name, role name and type name into the context. 1261 */ 1262 scontextp += sprintf(scontextp, "%s:%s:%s", 1263 sym_name(p, SYM_USERS, context->user - 1), 1264 sym_name(p, SYM_ROLES, context->role - 1), 1265 sym_name(p, SYM_TYPES, context->type - 1)); 1266 1267 mls_sid_to_context(p, context, &scontextp); 1268 1269 *scontextp = 0; 1270 1271 return 0; 1272 } 1273 1274 static int sidtab_entry_to_string(struct policydb *p, 1275 struct sidtab *sidtab, 1276 struct sidtab_entry *entry, 1277 char **scontext, u32 *scontext_len) 1278 { 1279 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); 1280 1281 if (rc != -ENOENT) 1282 return rc; 1283 1284 rc = context_struct_to_string(p, &entry->context, scontext, 1285 scontext_len); 1286 if (!rc && scontext) 1287 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); 1288 return rc; 1289 } 1290 1291 #include "initial_sid_to_string.h" 1292 1293 int security_sidtab_hash_stats(struct selinux_state *state, char *page) 1294 { 1295 struct selinux_policy *policy; 1296 int rc; 1297 1298 if (!selinux_initialized(state)) { 1299 pr_err("SELinux: %s: called before initial load_policy\n", 1300 __func__); 1301 return -EINVAL; 1302 } 1303 1304 rcu_read_lock(); 1305 policy = rcu_dereference(state->policy); 1306 rc = sidtab_hash_stats(policy->sidtab, page); 1307 rcu_read_unlock(); 1308 1309 return rc; 1310 } 1311 1312 const char *security_get_initial_sid_context(u32 sid) 1313 { 1314 if (unlikely(sid > SECINITSID_NUM)) 1315 return NULL; 1316 return initial_sid_to_string[sid]; 1317 } 1318 1319 static int security_sid_to_context_core(struct selinux_state *state, 1320 u32 sid, char **scontext, 1321 u32 *scontext_len, int force, 1322 int only_invalid) 1323 { 1324 struct selinux_policy *policy; 1325 struct policydb *policydb; 1326 struct sidtab *sidtab; 1327 struct sidtab_entry *entry; 1328 int rc = 0; 1329 1330 if (scontext) 1331 *scontext = NULL; 1332 *scontext_len = 0; 1333 1334 if (!selinux_initialized(state)) { 1335 if (sid <= SECINITSID_NUM) { 1336 char *scontextp; 1337 const char *s = initial_sid_to_string[sid]; 1338 1339 if (!s) 1340 return -EINVAL; 1341 *scontext_len = strlen(s) + 1; 1342 if (!scontext) 1343 return 0; 1344 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1345 if (!scontextp) 1346 return -ENOMEM; 1347 *scontext = scontextp; 1348 return 0; 1349 } 1350 pr_err("SELinux: %s: called before initial " 1351 "load_policy on unknown SID %d\n", __func__, sid); 1352 return -EINVAL; 1353 } 1354 rcu_read_lock(); 1355 policy = rcu_dereference(state->policy); 1356 policydb = &policy->policydb; 1357 sidtab = policy->sidtab; 1358 1359 if (force) 1360 entry = sidtab_search_entry_force(sidtab, sid); 1361 else 1362 entry = sidtab_search_entry(sidtab, sid); 1363 if (!entry) { 1364 pr_err("SELinux: %s: unrecognized SID %d\n", 1365 __func__, sid); 1366 rc = -EINVAL; 1367 goto out_unlock; 1368 } 1369 if (only_invalid && !entry->context.len) 1370 goto out_unlock; 1371 1372 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1373 scontext_len); 1374 1375 out_unlock: 1376 rcu_read_unlock(); 1377 return rc; 1378 1379 } 1380 1381 /** 1382 * security_sid_to_context - Obtain a context for a given SID. 1383 * @state: SELinux state 1384 * @sid: security identifier, SID 1385 * @scontext: security context 1386 * @scontext_len: length in bytes 1387 * 1388 * Write the string representation of the context associated with @sid 1389 * into a dynamically allocated string of the correct size. Set @scontext 1390 * to point to this string and set @scontext_len to the length of the string. 1391 */ 1392 int security_sid_to_context(struct selinux_state *state, 1393 u32 sid, char **scontext, u32 *scontext_len) 1394 { 1395 return security_sid_to_context_core(state, sid, scontext, 1396 scontext_len, 0, 0); 1397 } 1398 1399 int security_sid_to_context_force(struct selinux_state *state, u32 sid, 1400 char **scontext, u32 *scontext_len) 1401 { 1402 return security_sid_to_context_core(state, sid, scontext, 1403 scontext_len, 1, 0); 1404 } 1405 1406 /** 1407 * security_sid_to_context_inval - Obtain a context for a given SID if it 1408 * is invalid. 1409 * @state: SELinux state 1410 * @sid: security identifier, SID 1411 * @scontext: security context 1412 * @scontext_len: length in bytes 1413 * 1414 * Write the string representation of the context associated with @sid 1415 * into a dynamically allocated string of the correct size, but only if the 1416 * context is invalid in the current policy. Set @scontext to point to 1417 * this string (or NULL if the context is valid) and set @scontext_len to 1418 * the length of the string (or 0 if the context is valid). 1419 */ 1420 int security_sid_to_context_inval(struct selinux_state *state, u32 sid, 1421 char **scontext, u32 *scontext_len) 1422 { 1423 return security_sid_to_context_core(state, sid, scontext, 1424 scontext_len, 1, 1); 1425 } 1426 1427 /* 1428 * Caveat: Mutates scontext. 1429 */ 1430 static int string_to_context_struct(struct policydb *pol, 1431 struct sidtab *sidtabp, 1432 char *scontext, 1433 struct context *ctx, 1434 u32 def_sid) 1435 { 1436 struct role_datum *role; 1437 struct type_datum *typdatum; 1438 struct user_datum *usrdatum; 1439 char *scontextp, *p, oldc; 1440 int rc = 0; 1441 1442 context_init(ctx); 1443 1444 /* Parse the security context. */ 1445 1446 rc = -EINVAL; 1447 scontextp = scontext; 1448 1449 /* Extract the user. */ 1450 p = scontextp; 1451 while (*p && *p != ':') 1452 p++; 1453 1454 if (*p == 0) 1455 goto out; 1456 1457 *p++ = 0; 1458 1459 usrdatum = symtab_search(&pol->p_users, scontextp); 1460 if (!usrdatum) 1461 goto out; 1462 1463 ctx->user = usrdatum->value; 1464 1465 /* Extract role. */ 1466 scontextp = p; 1467 while (*p && *p != ':') 1468 p++; 1469 1470 if (*p == 0) 1471 goto out; 1472 1473 *p++ = 0; 1474 1475 role = symtab_search(&pol->p_roles, scontextp); 1476 if (!role) 1477 goto out; 1478 ctx->role = role->value; 1479 1480 /* Extract type. */ 1481 scontextp = p; 1482 while (*p && *p != ':') 1483 p++; 1484 oldc = *p; 1485 *p++ = 0; 1486 1487 typdatum = symtab_search(&pol->p_types, scontextp); 1488 if (!typdatum || typdatum->attribute) 1489 goto out; 1490 1491 ctx->type = typdatum->value; 1492 1493 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1494 if (rc) 1495 goto out; 1496 1497 /* Check the validity of the new context. */ 1498 rc = -EINVAL; 1499 if (!policydb_context_isvalid(pol, ctx)) 1500 goto out; 1501 rc = 0; 1502 out: 1503 if (rc) 1504 context_destroy(ctx); 1505 return rc; 1506 } 1507 1508 static int security_context_to_sid_core(struct selinux_state *state, 1509 const char *scontext, u32 scontext_len, 1510 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1511 int force) 1512 { 1513 struct selinux_policy *policy; 1514 struct policydb *policydb; 1515 struct sidtab *sidtab; 1516 char *scontext2, *str = NULL; 1517 struct context context; 1518 int rc = 0; 1519 1520 /* An empty security context is never valid. */ 1521 if (!scontext_len) 1522 return -EINVAL; 1523 1524 /* Copy the string to allow changes and ensure a NUL terminator */ 1525 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1526 if (!scontext2) 1527 return -ENOMEM; 1528 1529 if (!selinux_initialized(state)) { 1530 int i; 1531 1532 for (i = 1; i < SECINITSID_NUM; i++) { 1533 const char *s = initial_sid_to_string[i]; 1534 1535 if (s && !strcmp(s, scontext2)) { 1536 *sid = i; 1537 goto out; 1538 } 1539 } 1540 *sid = SECINITSID_KERNEL; 1541 goto out; 1542 } 1543 *sid = SECSID_NULL; 1544 1545 if (force) { 1546 /* Save another copy for storing in uninterpreted form */ 1547 rc = -ENOMEM; 1548 str = kstrdup(scontext2, gfp_flags); 1549 if (!str) 1550 goto out; 1551 } 1552 retry: 1553 rcu_read_lock(); 1554 policy = rcu_dereference(state->policy); 1555 policydb = &policy->policydb; 1556 sidtab = policy->sidtab; 1557 rc = string_to_context_struct(policydb, sidtab, scontext2, 1558 &context, def_sid); 1559 if (rc == -EINVAL && force) { 1560 context.str = str; 1561 context.len = strlen(str) + 1; 1562 str = NULL; 1563 } else if (rc) 1564 goto out_unlock; 1565 rc = sidtab_context_to_sid(sidtab, &context, sid); 1566 if (rc == -ESTALE) { 1567 rcu_read_unlock(); 1568 if (context.str) { 1569 str = context.str; 1570 context.str = NULL; 1571 } 1572 context_destroy(&context); 1573 goto retry; 1574 } 1575 context_destroy(&context); 1576 out_unlock: 1577 rcu_read_unlock(); 1578 out: 1579 kfree(scontext2); 1580 kfree(str); 1581 return rc; 1582 } 1583 1584 /** 1585 * security_context_to_sid - Obtain a SID for a given security context. 1586 * @state: SELinux state 1587 * @scontext: security context 1588 * @scontext_len: length in bytes 1589 * @sid: security identifier, SID 1590 * @gfp: context for the allocation 1591 * 1592 * Obtains a SID associated with the security context that 1593 * has the string representation specified by @scontext. 1594 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1595 * memory is available, or 0 on success. 1596 */ 1597 int security_context_to_sid(struct selinux_state *state, 1598 const char *scontext, u32 scontext_len, u32 *sid, 1599 gfp_t gfp) 1600 { 1601 return security_context_to_sid_core(state, scontext, scontext_len, 1602 sid, SECSID_NULL, gfp, 0); 1603 } 1604 1605 int security_context_str_to_sid(struct selinux_state *state, 1606 const char *scontext, u32 *sid, gfp_t gfp) 1607 { 1608 return security_context_to_sid(state, scontext, strlen(scontext), 1609 sid, gfp); 1610 } 1611 1612 /** 1613 * security_context_to_sid_default - Obtain a SID for a given security context, 1614 * falling back to specified default if needed. 1615 * 1616 * @state: SELinux state 1617 * @scontext: security context 1618 * @scontext_len: length in bytes 1619 * @sid: security identifier, SID 1620 * @def_sid: default SID to assign on error 1621 * @gfp_flags: the allocator get-free-page (GFP) flags 1622 * 1623 * Obtains a SID associated with the security context that 1624 * has the string representation specified by @scontext. 1625 * The default SID is passed to the MLS layer to be used to allow 1626 * kernel labeling of the MLS field if the MLS field is not present 1627 * (for upgrading to MLS without full relabel). 1628 * Implicitly forces adding of the context even if it cannot be mapped yet. 1629 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1630 * memory is available, or 0 on success. 1631 */ 1632 int security_context_to_sid_default(struct selinux_state *state, 1633 const char *scontext, u32 scontext_len, 1634 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1635 { 1636 return security_context_to_sid_core(state, scontext, scontext_len, 1637 sid, def_sid, gfp_flags, 1); 1638 } 1639 1640 int security_context_to_sid_force(struct selinux_state *state, 1641 const char *scontext, u32 scontext_len, 1642 u32 *sid) 1643 { 1644 return security_context_to_sid_core(state, scontext, scontext_len, 1645 sid, SECSID_NULL, GFP_KERNEL, 1); 1646 } 1647 1648 static int compute_sid_handle_invalid_context( 1649 struct selinux_state *state, 1650 struct selinux_policy *policy, 1651 struct sidtab_entry *sentry, 1652 struct sidtab_entry *tentry, 1653 u16 tclass, 1654 struct context *newcontext) 1655 { 1656 struct policydb *policydb = &policy->policydb; 1657 struct sidtab *sidtab = policy->sidtab; 1658 char *s = NULL, *t = NULL, *n = NULL; 1659 u32 slen, tlen, nlen; 1660 struct audit_buffer *ab; 1661 1662 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) 1663 goto out; 1664 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) 1665 goto out; 1666 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1667 goto out; 1668 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); 1669 if (!ab) 1670 goto out; 1671 audit_log_format(ab, 1672 "op=security_compute_sid invalid_context="); 1673 /* no need to record the NUL with untrusted strings */ 1674 audit_log_n_untrustedstring(ab, n, nlen - 1); 1675 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1676 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1677 audit_log_end(ab); 1678 out: 1679 kfree(s); 1680 kfree(t); 1681 kfree(n); 1682 if (!enforcing_enabled(state)) 1683 return 0; 1684 return -EACCES; 1685 } 1686 1687 static void filename_compute_type(struct policydb *policydb, 1688 struct context *newcontext, 1689 u32 stype, u32 ttype, u16 tclass, 1690 const char *objname) 1691 { 1692 struct filename_trans_key ft; 1693 struct filename_trans_datum *datum; 1694 1695 /* 1696 * Most filename trans rules are going to live in specific directories 1697 * like /dev or /var/run. This bitmap will quickly skip rule searches 1698 * if the ttype does not contain any rules. 1699 */ 1700 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1701 return; 1702 1703 ft.ttype = ttype; 1704 ft.tclass = tclass; 1705 ft.name = objname; 1706 1707 datum = policydb_filenametr_search(policydb, &ft); 1708 while (datum) { 1709 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1710 newcontext->type = datum->otype; 1711 return; 1712 } 1713 datum = datum->next; 1714 } 1715 } 1716 1717 static int security_compute_sid(struct selinux_state *state, 1718 u32 ssid, 1719 u32 tsid, 1720 u16 orig_tclass, 1721 u32 specified, 1722 const char *objname, 1723 u32 *out_sid, 1724 bool kern) 1725 { 1726 struct selinux_policy *policy; 1727 struct policydb *policydb; 1728 struct sidtab *sidtab; 1729 struct class_datum *cladatum; 1730 struct context *scontext, *tcontext, newcontext; 1731 struct sidtab_entry *sentry, *tentry; 1732 struct avtab_key avkey; 1733 struct avtab_datum *avdatum; 1734 struct avtab_node *node; 1735 u16 tclass; 1736 int rc = 0; 1737 bool sock; 1738 1739 if (!selinux_initialized(state)) { 1740 switch (orig_tclass) { 1741 case SECCLASS_PROCESS: /* kernel value */ 1742 *out_sid = ssid; 1743 break; 1744 default: 1745 *out_sid = tsid; 1746 break; 1747 } 1748 goto out; 1749 } 1750 1751 retry: 1752 cladatum = NULL; 1753 context_init(&newcontext); 1754 1755 rcu_read_lock(); 1756 1757 policy = rcu_dereference(state->policy); 1758 1759 if (kern) { 1760 tclass = unmap_class(&policy->map, orig_tclass); 1761 sock = security_is_socket_class(orig_tclass); 1762 } else { 1763 tclass = orig_tclass; 1764 sock = security_is_socket_class(map_class(&policy->map, 1765 tclass)); 1766 } 1767 1768 policydb = &policy->policydb; 1769 sidtab = policy->sidtab; 1770 1771 sentry = sidtab_search_entry(sidtab, ssid); 1772 if (!sentry) { 1773 pr_err("SELinux: %s: unrecognized SID %d\n", 1774 __func__, ssid); 1775 rc = -EINVAL; 1776 goto out_unlock; 1777 } 1778 tentry = sidtab_search_entry(sidtab, tsid); 1779 if (!tentry) { 1780 pr_err("SELinux: %s: unrecognized SID %d\n", 1781 __func__, tsid); 1782 rc = -EINVAL; 1783 goto out_unlock; 1784 } 1785 1786 scontext = &sentry->context; 1787 tcontext = &tentry->context; 1788 1789 if (tclass && tclass <= policydb->p_classes.nprim) 1790 cladatum = policydb->class_val_to_struct[tclass - 1]; 1791 1792 /* Set the user identity. */ 1793 switch (specified) { 1794 case AVTAB_TRANSITION: 1795 case AVTAB_CHANGE: 1796 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1797 newcontext.user = tcontext->user; 1798 } else { 1799 /* notice this gets both DEFAULT_SOURCE and unset */ 1800 /* Use the process user identity. */ 1801 newcontext.user = scontext->user; 1802 } 1803 break; 1804 case AVTAB_MEMBER: 1805 /* Use the related object owner. */ 1806 newcontext.user = tcontext->user; 1807 break; 1808 } 1809 1810 /* Set the role to default values. */ 1811 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1812 newcontext.role = scontext->role; 1813 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1814 newcontext.role = tcontext->role; 1815 } else { 1816 if ((tclass == policydb->process_class) || sock) 1817 newcontext.role = scontext->role; 1818 else 1819 newcontext.role = OBJECT_R_VAL; 1820 } 1821 1822 /* Set the type to default values. */ 1823 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1824 newcontext.type = scontext->type; 1825 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1826 newcontext.type = tcontext->type; 1827 } else { 1828 if ((tclass == policydb->process_class) || sock) { 1829 /* Use the type of process. */ 1830 newcontext.type = scontext->type; 1831 } else { 1832 /* Use the type of the related object. */ 1833 newcontext.type = tcontext->type; 1834 } 1835 } 1836 1837 /* Look for a type transition/member/change rule. */ 1838 avkey.source_type = scontext->type; 1839 avkey.target_type = tcontext->type; 1840 avkey.target_class = tclass; 1841 avkey.specified = specified; 1842 avdatum = avtab_search(&policydb->te_avtab, &avkey); 1843 1844 /* If no permanent rule, also check for enabled conditional rules */ 1845 if (!avdatum) { 1846 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1847 for (; node; node = avtab_search_node_next(node, specified)) { 1848 if (node->key.specified & AVTAB_ENABLED) { 1849 avdatum = &node->datum; 1850 break; 1851 } 1852 } 1853 } 1854 1855 if (avdatum) { 1856 /* Use the type from the type transition/member/change rule. */ 1857 newcontext.type = avdatum->u.data; 1858 } 1859 1860 /* if we have a objname this is a file trans check so check those rules */ 1861 if (objname) 1862 filename_compute_type(policydb, &newcontext, scontext->type, 1863 tcontext->type, tclass, objname); 1864 1865 /* Check for class-specific changes. */ 1866 if (specified & AVTAB_TRANSITION) { 1867 /* Look for a role transition rule. */ 1868 struct role_trans_datum *rtd; 1869 struct role_trans_key rtk = { 1870 .role = scontext->role, 1871 .type = tcontext->type, 1872 .tclass = tclass, 1873 }; 1874 1875 rtd = policydb_roletr_search(policydb, &rtk); 1876 if (rtd) 1877 newcontext.role = rtd->new_role; 1878 } 1879 1880 /* Set the MLS attributes. 1881 This is done last because it may allocate memory. */ 1882 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1883 &newcontext, sock); 1884 if (rc) 1885 goto out_unlock; 1886 1887 /* Check the validity of the context. */ 1888 if (!policydb_context_isvalid(policydb, &newcontext)) { 1889 rc = compute_sid_handle_invalid_context(state, policy, sentry, 1890 tentry, tclass, 1891 &newcontext); 1892 if (rc) 1893 goto out_unlock; 1894 } 1895 /* Obtain the sid for the context. */ 1896 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1897 if (rc == -ESTALE) { 1898 rcu_read_unlock(); 1899 context_destroy(&newcontext); 1900 goto retry; 1901 } 1902 out_unlock: 1903 rcu_read_unlock(); 1904 context_destroy(&newcontext); 1905 out: 1906 return rc; 1907 } 1908 1909 /** 1910 * security_transition_sid - Compute the SID for a new subject/object. 1911 * @state: SELinux state 1912 * @ssid: source security identifier 1913 * @tsid: target security identifier 1914 * @tclass: target security class 1915 * @qstr: object name 1916 * @out_sid: security identifier for new subject/object 1917 * 1918 * Compute a SID to use for labeling a new subject or object in the 1919 * class @tclass based on a SID pair (@ssid, @tsid). 1920 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1921 * if insufficient memory is available, or %0 if the new SID was 1922 * computed successfully. 1923 */ 1924 int security_transition_sid(struct selinux_state *state, 1925 u32 ssid, u32 tsid, u16 tclass, 1926 const struct qstr *qstr, u32 *out_sid) 1927 { 1928 return security_compute_sid(state, ssid, tsid, tclass, 1929 AVTAB_TRANSITION, 1930 qstr ? qstr->name : NULL, out_sid, true); 1931 } 1932 1933 int security_transition_sid_user(struct selinux_state *state, 1934 u32 ssid, u32 tsid, u16 tclass, 1935 const char *objname, u32 *out_sid) 1936 { 1937 return security_compute_sid(state, ssid, tsid, tclass, 1938 AVTAB_TRANSITION, 1939 objname, out_sid, false); 1940 } 1941 1942 /** 1943 * security_member_sid - Compute the SID for member selection. 1944 * @state: SELinux state 1945 * @ssid: source security identifier 1946 * @tsid: target security identifier 1947 * @tclass: target security class 1948 * @out_sid: security identifier for selected member 1949 * 1950 * Compute a SID to use when selecting a member of a polyinstantiated 1951 * object of class @tclass based on a SID pair (@ssid, @tsid). 1952 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1953 * if insufficient memory is available, or %0 if the SID was 1954 * computed successfully. 1955 */ 1956 int security_member_sid(struct selinux_state *state, 1957 u32 ssid, 1958 u32 tsid, 1959 u16 tclass, 1960 u32 *out_sid) 1961 { 1962 return security_compute_sid(state, ssid, tsid, tclass, 1963 AVTAB_MEMBER, NULL, 1964 out_sid, false); 1965 } 1966 1967 /** 1968 * security_change_sid - Compute the SID for object relabeling. 1969 * @state: SELinux state 1970 * @ssid: source security identifier 1971 * @tsid: target security identifier 1972 * @tclass: target security class 1973 * @out_sid: security identifier for selected member 1974 * 1975 * Compute a SID to use for relabeling an object of class @tclass 1976 * based on a SID pair (@ssid, @tsid). 1977 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1978 * if insufficient memory is available, or %0 if the SID was 1979 * computed successfully. 1980 */ 1981 int security_change_sid(struct selinux_state *state, 1982 u32 ssid, 1983 u32 tsid, 1984 u16 tclass, 1985 u32 *out_sid) 1986 { 1987 return security_compute_sid(state, 1988 ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1989 out_sid, false); 1990 } 1991 1992 static inline int convert_context_handle_invalid_context( 1993 struct selinux_state *state, 1994 struct policydb *policydb, 1995 struct context *context) 1996 { 1997 char *s; 1998 u32 len; 1999 2000 if (enforcing_enabled(state)) 2001 return -EINVAL; 2002 2003 if (!context_struct_to_string(policydb, context, &s, &len)) { 2004 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 2005 s); 2006 kfree(s); 2007 } 2008 return 0; 2009 } 2010 2011 /** 2012 * services_convert_context - Convert a security context across policies. 2013 * @args: populated convert_context_args struct 2014 * @oldc: original context 2015 * @newc: converted context 2016 * 2017 * Convert the values in the security context structure @oldc from the values 2018 * specified in the policy @args->oldp to the values specified in the policy 2019 * @args->newp, storing the new context in @newc, and verifying that the 2020 * context is valid under the new policy. 2021 */ 2022 int services_convert_context(struct convert_context_args *args, 2023 struct context *oldc, struct context *newc) 2024 { 2025 struct ocontext *oc; 2026 struct role_datum *role; 2027 struct type_datum *typdatum; 2028 struct user_datum *usrdatum; 2029 char *s; 2030 u32 len; 2031 int rc; 2032 2033 if (oldc->str) { 2034 s = kstrdup(oldc->str, GFP_KERNEL); 2035 if (!s) 2036 return -ENOMEM; 2037 2038 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL); 2039 if (rc == -EINVAL) { 2040 /* 2041 * Retain string representation for later mapping. 2042 * 2043 * IMPORTANT: We need to copy the contents of oldc->str 2044 * back into s again because string_to_context_struct() 2045 * may have garbled it. 2046 */ 2047 memcpy(s, oldc->str, oldc->len); 2048 context_init(newc); 2049 newc->str = s; 2050 newc->len = oldc->len; 2051 return 0; 2052 } 2053 kfree(s); 2054 if (rc) { 2055 /* Other error condition, e.g. ENOMEM. */ 2056 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2057 oldc->str, -rc); 2058 return rc; 2059 } 2060 pr_info("SELinux: Context %s became valid (mapped).\n", 2061 oldc->str); 2062 return 0; 2063 } 2064 2065 context_init(newc); 2066 2067 /* Convert the user. */ 2068 usrdatum = symtab_search(&args->newp->p_users, 2069 sym_name(args->oldp, SYM_USERS, oldc->user - 1)); 2070 if (!usrdatum) 2071 goto bad; 2072 newc->user = usrdatum->value; 2073 2074 /* Convert the role. */ 2075 role = symtab_search(&args->newp->p_roles, 2076 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2077 if (!role) 2078 goto bad; 2079 newc->role = role->value; 2080 2081 /* Convert the type. */ 2082 typdatum = symtab_search(&args->newp->p_types, 2083 sym_name(args->oldp, 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 if (!oc) { 2105 pr_err("SELinux: unable to look up" 2106 " the initial SIDs list\n"); 2107 goto bad; 2108 } 2109 rc = mls_range_set(newc, &oc->context[0].range); 2110 if (rc) 2111 goto bad; 2112 } 2113 2114 /* Check the validity of the new context. */ 2115 if (!policydb_context_isvalid(args->newp, newc)) { 2116 rc = convert_context_handle_invalid_context(args->state, 2117 args->oldp, oldc); 2118 if (rc) 2119 goto bad; 2120 } 2121 2122 return 0; 2123 bad: 2124 /* Map old representation to string and save it. */ 2125 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2126 if (rc) 2127 return rc; 2128 context_destroy(newc); 2129 newc->str = s; 2130 newc->len = len; 2131 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2132 newc->str); 2133 return 0; 2134 } 2135 2136 static void security_load_policycaps(struct selinux_state *state, 2137 struct selinux_policy *policy) 2138 { 2139 struct policydb *p; 2140 unsigned int i; 2141 struct ebitmap_node *node; 2142 2143 p = &policy->policydb; 2144 2145 for (i = 0; i < ARRAY_SIZE(state->policycap); i++) 2146 WRITE_ONCE(state->policycap[i], 2147 ebitmap_get_bit(&p->policycaps, i)); 2148 2149 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2150 pr_info("SELinux: policy capability %s=%d\n", 2151 selinux_policycap_names[i], 2152 ebitmap_get_bit(&p->policycaps, i)); 2153 2154 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2155 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2156 pr_info("SELinux: unknown policy capability %u\n", 2157 i); 2158 } 2159 } 2160 2161 static int security_preserve_bools(struct selinux_policy *oldpolicy, 2162 struct selinux_policy *newpolicy); 2163 2164 static void selinux_policy_free(struct selinux_policy *policy) 2165 { 2166 if (!policy) 2167 return; 2168 2169 sidtab_destroy(policy->sidtab); 2170 kfree(policy->map.mapping); 2171 policydb_destroy(&policy->policydb); 2172 kfree(policy->sidtab); 2173 kfree(policy); 2174 } 2175 2176 static void selinux_policy_cond_free(struct selinux_policy *policy) 2177 { 2178 cond_policydb_destroy_dup(&policy->policydb); 2179 kfree(policy); 2180 } 2181 2182 void selinux_policy_cancel(struct selinux_state *state, 2183 struct selinux_load_state *load_state) 2184 { 2185 struct selinux_policy *oldpolicy; 2186 2187 oldpolicy = rcu_dereference_protected(state->policy, 2188 lockdep_is_held(&state->policy_mutex)); 2189 2190 sidtab_cancel_convert(oldpolicy->sidtab); 2191 selinux_policy_free(load_state->policy); 2192 kfree(load_state->convert_data); 2193 } 2194 2195 static void selinux_notify_policy_change(struct selinux_state *state, 2196 u32 seqno) 2197 { 2198 /* Flush external caches and notify userspace of policy load */ 2199 avc_ss_reset(state->avc, seqno); 2200 selnl_notify_policyload(seqno); 2201 selinux_status_update_policyload(state, seqno); 2202 selinux_netlbl_cache_invalidate(); 2203 selinux_xfrm_notify_policyload(); 2204 selinux_ima_measure_state_locked(state); 2205 } 2206 2207 void selinux_policy_commit(struct selinux_state *state, 2208 struct selinux_load_state *load_state) 2209 { 2210 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2211 unsigned long flags; 2212 u32 seqno; 2213 2214 oldpolicy = rcu_dereference_protected(state->policy, 2215 lockdep_is_held(&state->policy_mutex)); 2216 2217 /* If switching between different policy types, log MLS status */ 2218 if (oldpolicy) { 2219 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2220 pr_info("SELinux: Disabling MLS support...\n"); 2221 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2222 pr_info("SELinux: Enabling MLS support...\n"); 2223 } 2224 2225 /* Set latest granting seqno for new policy. */ 2226 if (oldpolicy) 2227 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2228 else 2229 newpolicy->latest_granting = 1; 2230 seqno = newpolicy->latest_granting; 2231 2232 /* Install the new policy. */ 2233 if (oldpolicy) { 2234 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2235 rcu_assign_pointer(state->policy, newpolicy); 2236 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2237 } else { 2238 rcu_assign_pointer(state->policy, newpolicy); 2239 } 2240 2241 /* Load the policycaps from the new policy */ 2242 security_load_policycaps(state, newpolicy); 2243 2244 if (!selinux_initialized(state)) { 2245 /* 2246 * After first policy load, the security server is 2247 * marked as initialized and ready to handle requests and 2248 * any objects created prior to policy load are then labeled. 2249 */ 2250 selinux_mark_initialized(state); 2251 selinux_complete_init(); 2252 } 2253 2254 /* Free the old policy */ 2255 synchronize_rcu(); 2256 selinux_policy_free(oldpolicy); 2257 kfree(load_state->convert_data); 2258 2259 /* Notify others of the policy change */ 2260 selinux_notify_policy_change(state, seqno); 2261 } 2262 2263 /** 2264 * security_load_policy - Load a security policy configuration. 2265 * @state: SELinux state 2266 * @data: binary policy data 2267 * @len: length of data in bytes 2268 * @load_state: policy load state 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 /* 2327 * Convert the internal representations of contexts 2328 * in the new SID table. 2329 */ 2330 2331 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2332 if (!convert_data) { 2333 rc = -ENOMEM; 2334 goto err_free_isids; 2335 } 2336 2337 convert_data->args.state = state; 2338 convert_data->args.oldp = &oldpolicy->policydb; 2339 convert_data->args.newp = &newpolicy->policydb; 2340 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 * ocontext_to_sid - Helper to safely get sid for an ocontext 2374 * @sidtab: SID table 2375 * @c: ocontext structure 2376 * @index: index of the context entry (0 or 1) 2377 * @out_sid: pointer to the resulting SID value 2378 * 2379 * For all ocontexts except OCON_ISID the SID fields are populated 2380 * on-demand when needed. Since updating the SID value is an SMP-sensitive 2381 * operation, this helper must be used to do that safely. 2382 * 2383 * WARNING: This function may return -ESTALE, indicating that the caller 2384 * must retry the operation after re-acquiring the policy pointer! 2385 */ 2386 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, 2387 size_t index, u32 *out_sid) 2388 { 2389 int rc; 2390 u32 sid; 2391 2392 /* Ensure the associated sidtab entry is visible to this thread. */ 2393 sid = smp_load_acquire(&c->sid[index]); 2394 if (!sid) { 2395 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); 2396 if (rc) 2397 return rc; 2398 2399 /* 2400 * Ensure the new sidtab entry is visible to other threads 2401 * when they see the SID. 2402 */ 2403 smp_store_release(&c->sid[index], sid); 2404 } 2405 *out_sid = sid; 2406 return 0; 2407 } 2408 2409 /** 2410 * security_port_sid - Obtain the SID for a port. 2411 * @state: SELinux state 2412 * @protocol: protocol number 2413 * @port: port number 2414 * @out_sid: security identifier 2415 */ 2416 int security_port_sid(struct selinux_state *state, 2417 u8 protocol, u16 port, u32 *out_sid) 2418 { 2419 struct selinux_policy *policy; 2420 struct policydb *policydb; 2421 struct sidtab *sidtab; 2422 struct ocontext *c; 2423 int rc; 2424 2425 if (!selinux_initialized(state)) { 2426 *out_sid = SECINITSID_PORT; 2427 return 0; 2428 } 2429 2430 retry: 2431 rc = 0; 2432 rcu_read_lock(); 2433 policy = rcu_dereference(state->policy); 2434 policydb = &policy->policydb; 2435 sidtab = policy->sidtab; 2436 2437 c = policydb->ocontexts[OCON_PORT]; 2438 while (c) { 2439 if (c->u.port.protocol == protocol && 2440 c->u.port.low_port <= port && 2441 c->u.port.high_port >= port) 2442 break; 2443 c = c->next; 2444 } 2445 2446 if (c) { 2447 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2448 if (rc == -ESTALE) { 2449 rcu_read_unlock(); 2450 goto retry; 2451 } 2452 if (rc) 2453 goto out; 2454 } else { 2455 *out_sid = SECINITSID_PORT; 2456 } 2457 2458 out: 2459 rcu_read_unlock(); 2460 return rc; 2461 } 2462 2463 /** 2464 * security_ib_pkey_sid - Obtain the SID for a pkey. 2465 * @state: SELinux state 2466 * @subnet_prefix: Subnet Prefix 2467 * @pkey_num: pkey number 2468 * @out_sid: security identifier 2469 */ 2470 int security_ib_pkey_sid(struct selinux_state *state, 2471 u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2472 { 2473 struct selinux_policy *policy; 2474 struct policydb *policydb; 2475 struct sidtab *sidtab; 2476 struct ocontext *c; 2477 int rc; 2478 2479 if (!selinux_initialized(state)) { 2480 *out_sid = SECINITSID_UNLABELED; 2481 return 0; 2482 } 2483 2484 retry: 2485 rc = 0; 2486 rcu_read_lock(); 2487 policy = rcu_dereference(state->policy); 2488 policydb = &policy->policydb; 2489 sidtab = policy->sidtab; 2490 2491 c = policydb->ocontexts[OCON_IBPKEY]; 2492 while (c) { 2493 if (c->u.ibpkey.low_pkey <= pkey_num && 2494 c->u.ibpkey.high_pkey >= pkey_num && 2495 c->u.ibpkey.subnet_prefix == subnet_prefix) 2496 break; 2497 2498 c = c->next; 2499 } 2500 2501 if (c) { 2502 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2503 if (rc == -ESTALE) { 2504 rcu_read_unlock(); 2505 goto retry; 2506 } 2507 if (rc) 2508 goto out; 2509 } else 2510 *out_sid = SECINITSID_UNLABELED; 2511 2512 out: 2513 rcu_read_unlock(); 2514 return rc; 2515 } 2516 2517 /** 2518 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2519 * @state: SELinux state 2520 * @dev_name: device name 2521 * @port_num: port number 2522 * @out_sid: security identifier 2523 */ 2524 int security_ib_endport_sid(struct selinux_state *state, 2525 const char *dev_name, u8 port_num, u32 *out_sid) 2526 { 2527 struct selinux_policy *policy; 2528 struct policydb *policydb; 2529 struct sidtab *sidtab; 2530 struct ocontext *c; 2531 int rc; 2532 2533 if (!selinux_initialized(state)) { 2534 *out_sid = SECINITSID_UNLABELED; 2535 return 0; 2536 } 2537 2538 retry: 2539 rc = 0; 2540 rcu_read_lock(); 2541 policy = rcu_dereference(state->policy); 2542 policydb = &policy->policydb; 2543 sidtab = policy->sidtab; 2544 2545 c = policydb->ocontexts[OCON_IBENDPORT]; 2546 while (c) { 2547 if (c->u.ibendport.port == port_num && 2548 !strncmp(c->u.ibendport.dev_name, 2549 dev_name, 2550 IB_DEVICE_NAME_MAX)) 2551 break; 2552 2553 c = c->next; 2554 } 2555 2556 if (c) { 2557 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2558 if (rc == -ESTALE) { 2559 rcu_read_unlock(); 2560 goto retry; 2561 } 2562 if (rc) 2563 goto out; 2564 } else 2565 *out_sid = SECINITSID_UNLABELED; 2566 2567 out: 2568 rcu_read_unlock(); 2569 return rc; 2570 } 2571 2572 /** 2573 * security_netif_sid - Obtain the SID for a network interface. 2574 * @state: SELinux state 2575 * @name: interface name 2576 * @if_sid: interface SID 2577 */ 2578 int security_netif_sid(struct selinux_state *state, 2579 char *name, u32 *if_sid) 2580 { 2581 struct selinux_policy *policy; 2582 struct policydb *policydb; 2583 struct sidtab *sidtab; 2584 int rc; 2585 struct ocontext *c; 2586 2587 if (!selinux_initialized(state)) { 2588 *if_sid = SECINITSID_NETIF; 2589 return 0; 2590 } 2591 2592 retry: 2593 rc = 0; 2594 rcu_read_lock(); 2595 policy = rcu_dereference(state->policy); 2596 policydb = &policy->policydb; 2597 sidtab = policy->sidtab; 2598 2599 c = policydb->ocontexts[OCON_NETIF]; 2600 while (c) { 2601 if (strcmp(name, c->u.name) == 0) 2602 break; 2603 c = c->next; 2604 } 2605 2606 if (c) { 2607 rc = ocontext_to_sid(sidtab, c, 0, if_sid); 2608 if (rc == -ESTALE) { 2609 rcu_read_unlock(); 2610 goto retry; 2611 } 2612 if (rc) 2613 goto out; 2614 } else 2615 *if_sid = SECINITSID_NETIF; 2616 2617 out: 2618 rcu_read_unlock(); 2619 return rc; 2620 } 2621 2622 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2623 { 2624 int i, fail = 0; 2625 2626 for (i = 0; i < 4; i++) 2627 if (addr[i] != (input[i] & mask[i])) { 2628 fail = 1; 2629 break; 2630 } 2631 2632 return !fail; 2633 } 2634 2635 /** 2636 * security_node_sid - Obtain the SID for a node (host). 2637 * @state: SELinux state 2638 * @domain: communication domain aka address family 2639 * @addrp: address 2640 * @addrlen: address length in bytes 2641 * @out_sid: security identifier 2642 */ 2643 int security_node_sid(struct selinux_state *state, 2644 u16 domain, 2645 void *addrp, 2646 u32 addrlen, 2647 u32 *out_sid) 2648 { 2649 struct selinux_policy *policy; 2650 struct policydb *policydb; 2651 struct sidtab *sidtab; 2652 int rc; 2653 struct ocontext *c; 2654 2655 if (!selinux_initialized(state)) { 2656 *out_sid = SECINITSID_NODE; 2657 return 0; 2658 } 2659 2660 retry: 2661 rcu_read_lock(); 2662 policy = rcu_dereference(state->policy); 2663 policydb = &policy->policydb; 2664 sidtab = policy->sidtab; 2665 2666 switch (domain) { 2667 case AF_INET: { 2668 u32 addr; 2669 2670 rc = -EINVAL; 2671 if (addrlen != sizeof(u32)) 2672 goto out; 2673 2674 addr = *((u32 *)addrp); 2675 2676 c = policydb->ocontexts[OCON_NODE]; 2677 while (c) { 2678 if (c->u.node.addr == (addr & c->u.node.mask)) 2679 break; 2680 c = c->next; 2681 } 2682 break; 2683 } 2684 2685 case AF_INET6: 2686 rc = -EINVAL; 2687 if (addrlen != sizeof(u64) * 2) 2688 goto out; 2689 c = policydb->ocontexts[OCON_NODE6]; 2690 while (c) { 2691 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2692 c->u.node6.mask)) 2693 break; 2694 c = c->next; 2695 } 2696 break; 2697 2698 default: 2699 rc = 0; 2700 *out_sid = SECINITSID_NODE; 2701 goto out; 2702 } 2703 2704 if (c) { 2705 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2706 if (rc == -ESTALE) { 2707 rcu_read_unlock(); 2708 goto retry; 2709 } 2710 if (rc) 2711 goto out; 2712 } else { 2713 *out_sid = SECINITSID_NODE; 2714 } 2715 2716 rc = 0; 2717 out: 2718 rcu_read_unlock(); 2719 return rc; 2720 } 2721 2722 #define SIDS_NEL 25 2723 2724 /** 2725 * security_get_user_sids - Obtain reachable SIDs for a user. 2726 * @state: SELinux state 2727 * @fromsid: starting SID 2728 * @username: username 2729 * @sids: array of reachable SIDs for user 2730 * @nel: number of elements in @sids 2731 * 2732 * Generate the set of SIDs for legal security contexts 2733 * for a given user that can be reached by @fromsid. 2734 * Set *@sids to point to a dynamically allocated 2735 * array containing the set of SIDs. Set *@nel to the 2736 * number of elements in the array. 2737 */ 2738 2739 int security_get_user_sids(struct selinux_state *state, 2740 u32 fromsid, 2741 char *username, 2742 u32 **sids, 2743 u32 *nel) 2744 { 2745 struct selinux_policy *policy; 2746 struct policydb *policydb; 2747 struct sidtab *sidtab; 2748 struct context *fromcon, usercon; 2749 u32 *mysids = NULL, *mysids2, sid; 2750 u32 i, j, mynel, maxnel = SIDS_NEL; 2751 struct user_datum *user; 2752 struct role_datum *role; 2753 struct ebitmap_node *rnode, *tnode; 2754 int rc; 2755 2756 *sids = NULL; 2757 *nel = 0; 2758 2759 if (!selinux_initialized(state)) 2760 return 0; 2761 2762 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2763 if (!mysids) 2764 return -ENOMEM; 2765 2766 retry: 2767 mynel = 0; 2768 rcu_read_lock(); 2769 policy = rcu_dereference(state->policy); 2770 policydb = &policy->policydb; 2771 sidtab = policy->sidtab; 2772 2773 context_init(&usercon); 2774 2775 rc = -EINVAL; 2776 fromcon = sidtab_search(sidtab, fromsid); 2777 if (!fromcon) 2778 goto out_unlock; 2779 2780 rc = -EINVAL; 2781 user = symtab_search(&policydb->p_users, username); 2782 if (!user) 2783 goto out_unlock; 2784 2785 usercon.user = user->value; 2786 2787 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2788 role = policydb->role_val_to_struct[i]; 2789 usercon.role = i + 1; 2790 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2791 usercon.type = j + 1; 2792 2793 if (mls_setup_user_range(policydb, fromcon, user, 2794 &usercon)) 2795 continue; 2796 2797 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2798 if (rc == -ESTALE) { 2799 rcu_read_unlock(); 2800 goto retry; 2801 } 2802 if (rc) 2803 goto out_unlock; 2804 if (mynel < maxnel) { 2805 mysids[mynel++] = sid; 2806 } else { 2807 rc = -ENOMEM; 2808 maxnel += SIDS_NEL; 2809 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2810 if (!mysids2) 2811 goto out_unlock; 2812 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2813 kfree(mysids); 2814 mysids = mysids2; 2815 mysids[mynel++] = sid; 2816 } 2817 } 2818 } 2819 rc = 0; 2820 out_unlock: 2821 rcu_read_unlock(); 2822 if (rc || !mynel) { 2823 kfree(mysids); 2824 return rc; 2825 } 2826 2827 rc = -ENOMEM; 2828 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2829 if (!mysids2) { 2830 kfree(mysids); 2831 return rc; 2832 } 2833 for (i = 0, j = 0; i < mynel; i++) { 2834 struct av_decision dummy_avd; 2835 rc = avc_has_perm_noaudit(state, 2836 fromsid, mysids[i], 2837 SECCLASS_PROCESS, /* kernel value */ 2838 PROCESS__TRANSITION, AVC_STRICT, 2839 &dummy_avd); 2840 if (!rc) 2841 mysids2[j++] = mysids[i]; 2842 cond_resched(); 2843 } 2844 kfree(mysids); 2845 *sids = mysids2; 2846 *nel = j; 2847 return 0; 2848 } 2849 2850 /** 2851 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2852 * @policy: policy 2853 * @fstype: filesystem type 2854 * @path: path from root of mount 2855 * @orig_sclass: file security class 2856 * @sid: SID for path 2857 * 2858 * Obtain a SID to use for a file in a filesystem that 2859 * cannot support xattr or use a fixed labeling behavior like 2860 * transition SIDs or task SIDs. 2861 * 2862 * WARNING: This function may return -ESTALE, indicating that the caller 2863 * must retry the operation after re-acquiring the policy pointer! 2864 */ 2865 static inline int __security_genfs_sid(struct selinux_policy *policy, 2866 const char *fstype, 2867 const char *path, 2868 u16 orig_sclass, 2869 u32 *sid) 2870 { 2871 struct policydb *policydb = &policy->policydb; 2872 struct sidtab *sidtab = policy->sidtab; 2873 int len; 2874 u16 sclass; 2875 struct genfs *genfs; 2876 struct ocontext *c; 2877 int cmp = 0; 2878 2879 while (path[0] == '/' && path[1] == '/') 2880 path++; 2881 2882 sclass = unmap_class(&policy->map, orig_sclass); 2883 *sid = SECINITSID_UNLABELED; 2884 2885 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2886 cmp = strcmp(fstype, genfs->fstype); 2887 if (cmp <= 0) 2888 break; 2889 } 2890 2891 if (!genfs || cmp) 2892 return -ENOENT; 2893 2894 for (c = genfs->head; c; c = c->next) { 2895 len = strlen(c->u.name); 2896 if ((!c->v.sclass || sclass == c->v.sclass) && 2897 (strncmp(c->u.name, path, len) == 0)) 2898 break; 2899 } 2900 2901 if (!c) 2902 return -ENOENT; 2903 2904 return ocontext_to_sid(sidtab, c, 0, sid); 2905 } 2906 2907 /** 2908 * security_genfs_sid - Obtain a SID for a file in a filesystem 2909 * @state: SELinux state 2910 * @fstype: filesystem type 2911 * @path: path from root of mount 2912 * @orig_sclass: file security class 2913 * @sid: SID for path 2914 * 2915 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2916 * it afterward. 2917 */ 2918 int security_genfs_sid(struct selinux_state *state, 2919 const char *fstype, 2920 const char *path, 2921 u16 orig_sclass, 2922 u32 *sid) 2923 { 2924 struct selinux_policy *policy; 2925 int retval; 2926 2927 if (!selinux_initialized(state)) { 2928 *sid = SECINITSID_UNLABELED; 2929 return 0; 2930 } 2931 2932 do { 2933 rcu_read_lock(); 2934 policy = rcu_dereference(state->policy); 2935 retval = __security_genfs_sid(policy, fstype, path, 2936 orig_sclass, sid); 2937 rcu_read_unlock(); 2938 } while (retval == -ESTALE); 2939 return retval; 2940 } 2941 2942 int selinux_policy_genfs_sid(struct selinux_policy *policy, 2943 const char *fstype, 2944 const char *path, 2945 u16 orig_sclass, 2946 u32 *sid) 2947 { 2948 /* no lock required, policy is not yet accessible by other threads */ 2949 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2950 } 2951 2952 /** 2953 * security_fs_use - Determine how to handle labeling for a filesystem. 2954 * @state: SELinux state 2955 * @sb: superblock in question 2956 */ 2957 int security_fs_use(struct selinux_state *state, struct super_block *sb) 2958 { 2959 struct selinux_policy *policy; 2960 struct policydb *policydb; 2961 struct sidtab *sidtab; 2962 int rc; 2963 struct ocontext *c; 2964 struct superblock_security_struct *sbsec = selinux_superblock(sb); 2965 const char *fstype = sb->s_type->name; 2966 2967 if (!selinux_initialized(state)) { 2968 sbsec->behavior = SECURITY_FS_USE_NONE; 2969 sbsec->sid = SECINITSID_UNLABELED; 2970 return 0; 2971 } 2972 2973 retry: 2974 rcu_read_lock(); 2975 policy = rcu_dereference(state->policy); 2976 policydb = &policy->policydb; 2977 sidtab = policy->sidtab; 2978 2979 c = policydb->ocontexts[OCON_FSUSE]; 2980 while (c) { 2981 if (strcmp(fstype, c->u.name) == 0) 2982 break; 2983 c = c->next; 2984 } 2985 2986 if (c) { 2987 sbsec->behavior = c->v.behavior; 2988 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); 2989 if (rc == -ESTALE) { 2990 rcu_read_unlock(); 2991 goto retry; 2992 } 2993 if (rc) 2994 goto out; 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 * @state: SELinux state 3290 * @nlbl_sid: NetLabel SID 3291 * @nlbl_type: NetLabel labeling protocol type 3292 * @xfrm_sid: XFRM SID 3293 * @peer_sid: network peer sid 3294 * 3295 * Description: 3296 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3297 * resolved into a single SID it is returned via @peer_sid and the function 3298 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3299 * returns a negative value. A table summarizing the behavior is below: 3300 * 3301 * | function return | @sid 3302 * ------------------------------+-----------------+----------------- 3303 * no peer labels | 0 | SECSID_NULL 3304 * single peer label | 0 | <peer_label> 3305 * multiple, consistent labels | 0 | <peer_label> 3306 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3307 * 3308 */ 3309 int security_net_peersid_resolve(struct selinux_state *state, 3310 u32 nlbl_sid, u32 nlbl_type, 3311 u32 xfrm_sid, 3312 u32 *peer_sid) 3313 { 3314 struct selinux_policy *policy; 3315 struct policydb *policydb; 3316 struct sidtab *sidtab; 3317 int rc; 3318 struct context *nlbl_ctx; 3319 struct context *xfrm_ctx; 3320 3321 *peer_sid = SECSID_NULL; 3322 3323 /* handle the common (which also happens to be the set of easy) cases 3324 * right away, these two if statements catch everything involving a 3325 * single or absent peer SID/label */ 3326 if (xfrm_sid == SECSID_NULL) { 3327 *peer_sid = nlbl_sid; 3328 return 0; 3329 } 3330 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3331 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3332 * is present */ 3333 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3334 *peer_sid = xfrm_sid; 3335 return 0; 3336 } 3337 3338 if (!selinux_initialized(state)) 3339 return 0; 3340 3341 rcu_read_lock(); 3342 policy = rcu_dereference(state->policy); 3343 policydb = &policy->policydb; 3344 sidtab = policy->sidtab; 3345 3346 /* 3347 * We don't need to check initialized here since the only way both 3348 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3349 * security server was initialized and state->initialized was true. 3350 */ 3351 if (!policydb->mls_enabled) { 3352 rc = 0; 3353 goto out; 3354 } 3355 3356 rc = -EINVAL; 3357 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3358 if (!nlbl_ctx) { 3359 pr_err("SELinux: %s: unrecognized SID %d\n", 3360 __func__, nlbl_sid); 3361 goto out; 3362 } 3363 rc = -EINVAL; 3364 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3365 if (!xfrm_ctx) { 3366 pr_err("SELinux: %s: unrecognized SID %d\n", 3367 __func__, xfrm_sid); 3368 goto out; 3369 } 3370 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3371 if (rc) 3372 goto out; 3373 3374 /* at present NetLabel SIDs/labels really only carry MLS 3375 * information so if the MLS portion of the NetLabel SID 3376 * matches the MLS portion of the labeled XFRM SID/label 3377 * then pass along the XFRM SID as it is the most 3378 * expressive */ 3379 *peer_sid = xfrm_sid; 3380 out: 3381 rcu_read_unlock(); 3382 return rc; 3383 } 3384 3385 static int get_classes_callback(void *k, void *d, void *args) 3386 { 3387 struct class_datum *datum = d; 3388 char *name = k, **classes = args; 3389 int value = datum->value - 1; 3390 3391 classes[value] = kstrdup(name, GFP_ATOMIC); 3392 if (!classes[value]) 3393 return -ENOMEM; 3394 3395 return 0; 3396 } 3397 3398 int security_get_classes(struct selinux_policy *policy, 3399 char ***classes, int *nclasses) 3400 { 3401 struct policydb *policydb; 3402 int rc; 3403 3404 policydb = &policy->policydb; 3405 3406 rc = -ENOMEM; 3407 *nclasses = policydb->p_classes.nprim; 3408 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3409 if (!*classes) 3410 goto out; 3411 3412 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3413 *classes); 3414 if (rc) { 3415 int i; 3416 for (i = 0; i < *nclasses; i++) 3417 kfree((*classes)[i]); 3418 kfree(*classes); 3419 } 3420 3421 out: 3422 return rc; 3423 } 3424 3425 static int get_permissions_callback(void *k, void *d, void *args) 3426 { 3427 struct perm_datum *datum = d; 3428 char *name = k, **perms = args; 3429 int value = datum->value - 1; 3430 3431 perms[value] = kstrdup(name, GFP_ATOMIC); 3432 if (!perms[value]) 3433 return -ENOMEM; 3434 3435 return 0; 3436 } 3437 3438 int security_get_permissions(struct selinux_policy *policy, 3439 char *class, char ***perms, int *nperms) 3440 { 3441 struct policydb *policydb; 3442 int rc, i; 3443 struct class_datum *match; 3444 3445 policydb = &policy->policydb; 3446 3447 rc = -EINVAL; 3448 match = symtab_search(&policydb->p_classes, class); 3449 if (!match) { 3450 pr_err("SELinux: %s: unrecognized class %s\n", 3451 __func__, class); 3452 goto out; 3453 } 3454 3455 rc = -ENOMEM; 3456 *nperms = match->permissions.nprim; 3457 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3458 if (!*perms) 3459 goto out; 3460 3461 if (match->comdatum) { 3462 rc = hashtab_map(&match->comdatum->permissions.table, 3463 get_permissions_callback, *perms); 3464 if (rc) 3465 goto err; 3466 } 3467 3468 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3469 *perms); 3470 if (rc) 3471 goto err; 3472 3473 out: 3474 return rc; 3475 3476 err: 3477 for (i = 0; i < *nperms; i++) 3478 kfree((*perms)[i]); 3479 kfree(*perms); 3480 return rc; 3481 } 3482 3483 int security_get_reject_unknown(struct selinux_state *state) 3484 { 3485 struct selinux_policy *policy; 3486 int value; 3487 3488 if (!selinux_initialized(state)) 3489 return 0; 3490 3491 rcu_read_lock(); 3492 policy = rcu_dereference(state->policy); 3493 value = policy->policydb.reject_unknown; 3494 rcu_read_unlock(); 3495 return value; 3496 } 3497 3498 int security_get_allow_unknown(struct selinux_state *state) 3499 { 3500 struct selinux_policy *policy; 3501 int value; 3502 3503 if (!selinux_initialized(state)) 3504 return 0; 3505 3506 rcu_read_lock(); 3507 policy = rcu_dereference(state->policy); 3508 value = policy->policydb.allow_unknown; 3509 rcu_read_unlock(); 3510 return value; 3511 } 3512 3513 /** 3514 * security_policycap_supported - Check for a specific policy capability 3515 * @state: SELinux state 3516 * @req_cap: capability 3517 * 3518 * Description: 3519 * This function queries the currently loaded policy to see if it supports the 3520 * capability specified by @req_cap. Returns true (1) if the capability is 3521 * supported, false (0) if it isn't supported. 3522 * 3523 */ 3524 int security_policycap_supported(struct selinux_state *state, 3525 unsigned int req_cap) 3526 { 3527 struct selinux_policy *policy; 3528 int rc; 3529 3530 if (!selinux_initialized(state)) 3531 return 0; 3532 3533 rcu_read_lock(); 3534 policy = rcu_dereference(state->policy); 3535 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3536 rcu_read_unlock(); 3537 3538 return rc; 3539 } 3540 3541 struct selinux_audit_rule { 3542 u32 au_seqno; 3543 struct context au_ctxt; 3544 }; 3545 3546 void selinux_audit_rule_free(void *vrule) 3547 { 3548 struct selinux_audit_rule *rule = vrule; 3549 3550 if (rule) { 3551 context_destroy(&rule->au_ctxt); 3552 kfree(rule); 3553 } 3554 } 3555 3556 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3557 { 3558 struct selinux_state *state = &selinux_state; 3559 struct selinux_policy *policy; 3560 struct policydb *policydb; 3561 struct selinux_audit_rule *tmprule; 3562 struct role_datum *roledatum; 3563 struct type_datum *typedatum; 3564 struct user_datum *userdatum; 3565 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3566 int rc = 0; 3567 3568 *rule = NULL; 3569 3570 if (!selinux_initialized(state)) 3571 return -EOPNOTSUPP; 3572 3573 switch (field) { 3574 case AUDIT_SUBJ_USER: 3575 case AUDIT_SUBJ_ROLE: 3576 case AUDIT_SUBJ_TYPE: 3577 case AUDIT_OBJ_USER: 3578 case AUDIT_OBJ_ROLE: 3579 case AUDIT_OBJ_TYPE: 3580 /* only 'equals' and 'not equals' fit user, role, and type */ 3581 if (op != Audit_equal && op != Audit_not_equal) 3582 return -EINVAL; 3583 break; 3584 case AUDIT_SUBJ_SEN: 3585 case AUDIT_SUBJ_CLR: 3586 case AUDIT_OBJ_LEV_LOW: 3587 case AUDIT_OBJ_LEV_HIGH: 3588 /* we do not allow a range, indicated by the presence of '-' */ 3589 if (strchr(rulestr, '-')) 3590 return -EINVAL; 3591 break; 3592 default: 3593 /* only the above fields are valid */ 3594 return -EINVAL; 3595 } 3596 3597 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3598 if (!tmprule) 3599 return -ENOMEM; 3600 3601 context_init(&tmprule->au_ctxt); 3602 3603 rcu_read_lock(); 3604 policy = rcu_dereference(state->policy); 3605 policydb = &policy->policydb; 3606 3607 tmprule->au_seqno = policy->latest_granting; 3608 3609 switch (field) { 3610 case AUDIT_SUBJ_USER: 3611 case AUDIT_OBJ_USER: 3612 rc = -EINVAL; 3613 userdatum = symtab_search(&policydb->p_users, rulestr); 3614 if (!userdatum) 3615 goto out; 3616 tmprule->au_ctxt.user = userdatum->value; 3617 break; 3618 case AUDIT_SUBJ_ROLE: 3619 case AUDIT_OBJ_ROLE: 3620 rc = -EINVAL; 3621 roledatum = symtab_search(&policydb->p_roles, rulestr); 3622 if (!roledatum) 3623 goto out; 3624 tmprule->au_ctxt.role = roledatum->value; 3625 break; 3626 case AUDIT_SUBJ_TYPE: 3627 case AUDIT_OBJ_TYPE: 3628 rc = -EINVAL; 3629 typedatum = symtab_search(&policydb->p_types, rulestr); 3630 if (!typedatum) 3631 goto out; 3632 tmprule->au_ctxt.type = typedatum->value; 3633 break; 3634 case AUDIT_SUBJ_SEN: 3635 case AUDIT_SUBJ_CLR: 3636 case AUDIT_OBJ_LEV_LOW: 3637 case AUDIT_OBJ_LEV_HIGH: 3638 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3639 GFP_ATOMIC); 3640 if (rc) 3641 goto out; 3642 break; 3643 } 3644 rc = 0; 3645 out: 3646 rcu_read_unlock(); 3647 3648 if (rc) { 3649 selinux_audit_rule_free(tmprule); 3650 tmprule = NULL; 3651 } 3652 3653 *rule = tmprule; 3654 3655 return rc; 3656 } 3657 3658 /* Check to see if the rule contains any selinux fields */ 3659 int selinux_audit_rule_known(struct audit_krule *rule) 3660 { 3661 int i; 3662 3663 for (i = 0; i < rule->field_count; i++) { 3664 struct audit_field *f = &rule->fields[i]; 3665 switch (f->type) { 3666 case AUDIT_SUBJ_USER: 3667 case AUDIT_SUBJ_ROLE: 3668 case AUDIT_SUBJ_TYPE: 3669 case AUDIT_SUBJ_SEN: 3670 case AUDIT_SUBJ_CLR: 3671 case AUDIT_OBJ_USER: 3672 case AUDIT_OBJ_ROLE: 3673 case AUDIT_OBJ_TYPE: 3674 case AUDIT_OBJ_LEV_LOW: 3675 case AUDIT_OBJ_LEV_HIGH: 3676 return 1; 3677 } 3678 } 3679 3680 return 0; 3681 } 3682 3683 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) 3684 { 3685 struct selinux_state *state = &selinux_state; 3686 struct selinux_policy *policy; 3687 struct context *ctxt; 3688 struct mls_level *level; 3689 struct selinux_audit_rule *rule = vrule; 3690 int match = 0; 3691 3692 if (unlikely(!rule)) { 3693 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3694 return -ENOENT; 3695 } 3696 3697 if (!selinux_initialized(state)) 3698 return 0; 3699 3700 rcu_read_lock(); 3701 3702 policy = rcu_dereference(state->policy); 3703 3704 if (rule->au_seqno < policy->latest_granting) { 3705 match = -ESTALE; 3706 goto out; 3707 } 3708 3709 ctxt = sidtab_search(policy->sidtab, sid); 3710 if (unlikely(!ctxt)) { 3711 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3712 sid); 3713 match = -ENOENT; 3714 goto out; 3715 } 3716 3717 /* a field/op pair that is not caught here will simply fall through 3718 without a match */ 3719 switch (field) { 3720 case AUDIT_SUBJ_USER: 3721 case AUDIT_OBJ_USER: 3722 switch (op) { 3723 case Audit_equal: 3724 match = (ctxt->user == rule->au_ctxt.user); 3725 break; 3726 case Audit_not_equal: 3727 match = (ctxt->user != rule->au_ctxt.user); 3728 break; 3729 } 3730 break; 3731 case AUDIT_SUBJ_ROLE: 3732 case AUDIT_OBJ_ROLE: 3733 switch (op) { 3734 case Audit_equal: 3735 match = (ctxt->role == rule->au_ctxt.role); 3736 break; 3737 case Audit_not_equal: 3738 match = (ctxt->role != rule->au_ctxt.role); 3739 break; 3740 } 3741 break; 3742 case AUDIT_SUBJ_TYPE: 3743 case AUDIT_OBJ_TYPE: 3744 switch (op) { 3745 case Audit_equal: 3746 match = (ctxt->type == rule->au_ctxt.type); 3747 break; 3748 case Audit_not_equal: 3749 match = (ctxt->type != rule->au_ctxt.type); 3750 break; 3751 } 3752 break; 3753 case AUDIT_SUBJ_SEN: 3754 case AUDIT_SUBJ_CLR: 3755 case AUDIT_OBJ_LEV_LOW: 3756 case AUDIT_OBJ_LEV_HIGH: 3757 level = ((field == AUDIT_SUBJ_SEN || 3758 field == AUDIT_OBJ_LEV_LOW) ? 3759 &ctxt->range.level[0] : &ctxt->range.level[1]); 3760 switch (op) { 3761 case Audit_equal: 3762 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3763 level); 3764 break; 3765 case Audit_not_equal: 3766 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3767 level); 3768 break; 3769 case Audit_lt: 3770 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3771 level) && 3772 !mls_level_eq(&rule->au_ctxt.range.level[0], 3773 level)); 3774 break; 3775 case Audit_le: 3776 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3777 level); 3778 break; 3779 case Audit_gt: 3780 match = (mls_level_dom(level, 3781 &rule->au_ctxt.range.level[0]) && 3782 !mls_level_eq(level, 3783 &rule->au_ctxt.range.level[0])); 3784 break; 3785 case Audit_ge: 3786 match = mls_level_dom(level, 3787 &rule->au_ctxt.range.level[0]); 3788 break; 3789 } 3790 } 3791 3792 out: 3793 rcu_read_unlock(); 3794 return match; 3795 } 3796 3797 static int aurule_avc_callback(u32 event) 3798 { 3799 if (event == AVC_CALLBACK_RESET) 3800 return audit_update_lsm_rules(); 3801 return 0; 3802 } 3803 3804 static int __init aurule_init(void) 3805 { 3806 int err; 3807 3808 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3809 if (err) 3810 panic("avc_add_callback() failed, error %d\n", err); 3811 3812 return err; 3813 } 3814 __initcall(aurule_init); 3815 3816 #ifdef CONFIG_NETLABEL 3817 /** 3818 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3819 * @secattr: the NetLabel packet security attributes 3820 * @sid: the SELinux SID 3821 * 3822 * Description: 3823 * Attempt to cache the context in @ctx, which was derived from the packet in 3824 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3825 * already been initialized. 3826 * 3827 */ 3828 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3829 u32 sid) 3830 { 3831 u32 *sid_cache; 3832 3833 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3834 if (sid_cache == NULL) 3835 return; 3836 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3837 if (secattr->cache == NULL) { 3838 kfree(sid_cache); 3839 return; 3840 } 3841 3842 *sid_cache = sid; 3843 secattr->cache->free = kfree; 3844 secattr->cache->data = sid_cache; 3845 secattr->flags |= NETLBL_SECATTR_CACHE; 3846 } 3847 3848 /** 3849 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3850 * @state: SELinux state 3851 * @secattr: the NetLabel packet security attributes 3852 * @sid: the SELinux SID 3853 * 3854 * Description: 3855 * Convert the given NetLabel security attributes in @secattr into a 3856 * SELinux SID. If the @secattr field does not contain a full SELinux 3857 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3858 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3859 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3860 * conversion for future lookups. Returns zero on success, negative values on 3861 * failure. 3862 * 3863 */ 3864 int security_netlbl_secattr_to_sid(struct selinux_state *state, 3865 struct netlbl_lsm_secattr *secattr, 3866 u32 *sid) 3867 { 3868 struct selinux_policy *policy; 3869 struct policydb *policydb; 3870 struct sidtab *sidtab; 3871 int rc; 3872 struct context *ctx; 3873 struct context ctx_new; 3874 3875 if (!selinux_initialized(state)) { 3876 *sid = SECSID_NULL; 3877 return 0; 3878 } 3879 3880 retry: 3881 rc = 0; 3882 rcu_read_lock(); 3883 policy = rcu_dereference(state->policy); 3884 policydb = &policy->policydb; 3885 sidtab = policy->sidtab; 3886 3887 if (secattr->flags & NETLBL_SECATTR_CACHE) 3888 *sid = *(u32 *)secattr->cache->data; 3889 else if (secattr->flags & NETLBL_SECATTR_SECID) 3890 *sid = secattr->attr.secid; 3891 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3892 rc = -EIDRM; 3893 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3894 if (ctx == NULL) 3895 goto out; 3896 3897 context_init(&ctx_new); 3898 ctx_new.user = ctx->user; 3899 ctx_new.role = ctx->role; 3900 ctx_new.type = ctx->type; 3901 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3902 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3903 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3904 if (rc) 3905 goto out; 3906 } 3907 rc = -EIDRM; 3908 if (!mls_context_isvalid(policydb, &ctx_new)) { 3909 ebitmap_destroy(&ctx_new.range.level[0].cat); 3910 goto out; 3911 } 3912 3913 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3914 ebitmap_destroy(&ctx_new.range.level[0].cat); 3915 if (rc == -ESTALE) { 3916 rcu_read_unlock(); 3917 goto retry; 3918 } 3919 if (rc) 3920 goto out; 3921 3922 security_netlbl_cache_add(secattr, *sid); 3923 } else 3924 *sid = SECSID_NULL; 3925 3926 out: 3927 rcu_read_unlock(); 3928 return rc; 3929 } 3930 3931 /** 3932 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3933 * @state: SELinux state 3934 * @sid: the SELinux SID 3935 * @secattr: the NetLabel packet security attributes 3936 * 3937 * Description: 3938 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3939 * Returns zero on success, negative values on failure. 3940 * 3941 */ 3942 int security_netlbl_sid_to_secattr(struct selinux_state *state, 3943 u32 sid, struct netlbl_lsm_secattr *secattr) 3944 { 3945 struct selinux_policy *policy; 3946 struct policydb *policydb; 3947 int rc; 3948 struct context *ctx; 3949 3950 if (!selinux_initialized(state)) 3951 return 0; 3952 3953 rcu_read_lock(); 3954 policy = rcu_dereference(state->policy); 3955 policydb = &policy->policydb; 3956 3957 rc = -ENOENT; 3958 ctx = sidtab_search(policy->sidtab, sid); 3959 if (ctx == NULL) 3960 goto out; 3961 3962 rc = -ENOMEM; 3963 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3964 GFP_ATOMIC); 3965 if (secattr->domain == NULL) 3966 goto out; 3967 3968 secattr->attr.secid = sid; 3969 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3970 mls_export_netlbl_lvl(policydb, ctx, secattr); 3971 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3972 out: 3973 rcu_read_unlock(); 3974 return rc; 3975 } 3976 #endif /* CONFIG_NETLABEL */ 3977 3978 /** 3979 * __security_read_policy - read the policy. 3980 * @policy: SELinux policy 3981 * @data: binary policy data 3982 * @len: length of data in bytes 3983 * 3984 */ 3985 static int __security_read_policy(struct selinux_policy *policy, 3986 void *data, size_t *len) 3987 { 3988 int rc; 3989 struct policy_file fp; 3990 3991 fp.data = data; 3992 fp.len = *len; 3993 3994 rc = policydb_write(&policy->policydb, &fp); 3995 if (rc) 3996 return rc; 3997 3998 *len = (unsigned long)fp.data - (unsigned long)data; 3999 return 0; 4000 } 4001 4002 /** 4003 * security_read_policy - read the policy. 4004 * @state: selinux_state 4005 * @data: binary policy data 4006 * @len: length of data in bytes 4007 * 4008 */ 4009 int security_read_policy(struct selinux_state *state, 4010 void **data, size_t *len) 4011 { 4012 struct selinux_policy *policy; 4013 4014 policy = rcu_dereference_protected( 4015 state->policy, lockdep_is_held(&state->policy_mutex)); 4016 if (!policy) 4017 return -EINVAL; 4018 4019 *len = policy->policydb.len; 4020 *data = vmalloc_user(*len); 4021 if (!*data) 4022 return -ENOMEM; 4023 4024 return __security_read_policy(policy, *data, len); 4025 } 4026 4027 /** 4028 * security_read_state_kernel - read the policy. 4029 * @state: selinux_state 4030 * @data: binary policy data 4031 * @len: length of data in bytes 4032 * 4033 * Allocates kernel memory for reading SELinux policy. 4034 * This function is for internal use only and should not 4035 * be used for returning data to user space. 4036 * 4037 * This function must be called with policy_mutex held. 4038 */ 4039 int security_read_state_kernel(struct selinux_state *state, 4040 void **data, size_t *len) 4041 { 4042 int err; 4043 struct selinux_policy *policy; 4044 4045 policy = rcu_dereference_protected( 4046 state->policy, lockdep_is_held(&state->policy_mutex)); 4047 if (!policy) 4048 return -EINVAL; 4049 4050 *len = policy->policydb.len; 4051 *data = vmalloc(*len); 4052 if (!*data) 4053 return -ENOMEM; 4054 4055 err = __security_read_policy(policy, *data, len); 4056 if (err) { 4057 vfree(*data); 4058 *data = NULL; 4059 *len = 0; 4060 } 4061 return err; 4062 } 4063