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 <net/netlabel.h> 51 52 #include "flask.h" 53 #include "avc.h" 54 #include "avc_ss.h" 55 #include "security.h" 56 #include "context.h" 57 #include "policydb.h" 58 #include "sidtab.h" 59 #include "services.h" 60 #include "conditional.h" 61 #include "mls.h" 62 #include "objsec.h" 63 #include "netlabel.h" 64 #include "xfrm.h" 65 #include "ebitmap.h" 66 #include "audit.h" 67 #include "policycap_names.h" 68 #include "ima.h" 69 70 struct convert_context_args { 71 struct selinux_state *state; 72 struct policydb *oldp; 73 struct policydb *newp; 74 }; 75 76 struct selinux_policy_convert_data { 77 struct convert_context_args args; 78 struct sidtab_convert_params sidtab_params; 79 }; 80 81 /* Forward declaration. */ 82 static int context_struct_to_string(struct policydb *policydb, 83 struct context *context, 84 char **scontext, 85 u32 *scontext_len); 86 87 static int sidtab_entry_to_string(struct policydb *policydb, 88 struct sidtab *sidtab, 89 struct sidtab_entry *entry, 90 char **scontext, 91 u32 *scontext_len); 92 93 static void context_struct_compute_av(struct policydb *policydb, 94 struct context *scontext, 95 struct context *tcontext, 96 u16 tclass, 97 struct av_decision *avd, 98 struct extended_perms *xperms); 99 100 static int selinux_set_mapping(struct policydb *pol, 101 struct security_class_mapping *map, 102 struct selinux_map *out_map) 103 { 104 u16 i, j; 105 unsigned k; 106 bool print_unknown_handle = false; 107 108 /* Find number of classes in the input mapping */ 109 if (!map) 110 return -EINVAL; 111 i = 0; 112 while (map[i].name) 113 i++; 114 115 /* Allocate space for the class records, plus one for class zero */ 116 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 117 if (!out_map->mapping) 118 return -ENOMEM; 119 120 /* Store the raw class and permission values */ 121 j = 0; 122 while (map[j].name) { 123 struct security_class_mapping *p_in = map + (j++); 124 struct selinux_mapping *p_out = out_map->mapping + j; 125 126 /* An empty class string skips ahead */ 127 if (!strcmp(p_in->name, "")) { 128 p_out->num_perms = 0; 129 continue; 130 } 131 132 p_out->value = string_to_security_class(pol, p_in->name); 133 if (!p_out->value) { 134 pr_info("SELinux: Class %s not defined in policy.\n", 135 p_in->name); 136 if (pol->reject_unknown) 137 goto err; 138 p_out->num_perms = 0; 139 print_unknown_handle = true; 140 continue; 141 } 142 143 k = 0; 144 while (p_in->perms[k]) { 145 /* An empty permission string skips ahead */ 146 if (!*p_in->perms[k]) { 147 k++; 148 continue; 149 } 150 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 151 p_in->perms[k]); 152 if (!p_out->perms[k]) { 153 pr_info("SELinux: Permission %s in class %s not defined in policy.\n", 154 p_in->perms[k], p_in->name); 155 if (pol->reject_unknown) 156 goto err; 157 print_unknown_handle = true; 158 } 159 160 k++; 161 } 162 p_out->num_perms = k; 163 } 164 165 if (print_unknown_handle) 166 pr_info("SELinux: the above unknown classes and permissions will be %s\n", 167 pol->allow_unknown ? "allowed" : "denied"); 168 169 out_map->size = i; 170 return 0; 171 err: 172 kfree(out_map->mapping); 173 out_map->mapping = NULL; 174 return -EINVAL; 175 } 176 177 /* 178 * Get real, policy values from mapped values 179 */ 180 181 static u16 unmap_class(struct selinux_map *map, u16 tclass) 182 { 183 if (tclass < map->size) 184 return map->mapping[tclass].value; 185 186 return tclass; 187 } 188 189 /* 190 * Get kernel value for class from its policy value 191 */ 192 static u16 map_class(struct selinux_map *map, u16 pol_value) 193 { 194 u16 i; 195 196 for (i = 1; i < map->size; i++) { 197 if (map->mapping[i].value == pol_value) 198 return i; 199 } 200 201 return SECCLASS_NULL; 202 } 203 204 static void map_decision(struct selinux_map *map, 205 u16 tclass, struct av_decision *avd, 206 int allow_unknown) 207 { 208 if (tclass < map->size) { 209 struct selinux_mapping *mapping = &map->mapping[tclass]; 210 unsigned int i, n = mapping->num_perms; 211 u32 result; 212 213 for (i = 0, result = 0; i < n; i++) { 214 if (avd->allowed & mapping->perms[i]) 215 result |= 1<<i; 216 if (allow_unknown && !mapping->perms[i]) 217 result |= 1<<i; 218 } 219 avd->allowed = result; 220 221 for (i = 0, result = 0; i < n; i++) 222 if (avd->auditallow & mapping->perms[i]) 223 result |= 1<<i; 224 avd->auditallow = result; 225 226 for (i = 0, result = 0; i < n; i++) { 227 if (avd->auditdeny & mapping->perms[i]) 228 result |= 1<<i; 229 if (!allow_unknown && !mapping->perms[i]) 230 result |= 1<<i; 231 } 232 /* 233 * In case the kernel has a bug and requests a permission 234 * between num_perms and the maximum permission number, we 235 * should audit that denial 236 */ 237 for (; i < (sizeof(u32)*8); i++) 238 result |= 1<<i; 239 avd->auditdeny = result; 240 } 241 } 242 243 int security_mls_enabled(struct selinux_state *state) 244 { 245 int mls_enabled; 246 struct selinux_policy *policy; 247 248 if (!selinux_initialized(state)) 249 return 0; 250 251 rcu_read_lock(); 252 policy = rcu_dereference(state->policy); 253 mls_enabled = policy->policydb.mls_enabled; 254 rcu_read_unlock(); 255 return mls_enabled; 256 } 257 258 /* 259 * Return the boolean value of a constraint expression 260 * when it is applied to the specified source and target 261 * security contexts. 262 * 263 * xcontext is a special beast... It is used by the validatetrans rules 264 * only. For these rules, scontext is the context before the transition, 265 * tcontext is the context after the transition, and xcontext is the context 266 * of the process performing the transition. All other callers of 267 * constraint_expr_eval should pass in NULL for xcontext. 268 */ 269 static int constraint_expr_eval(struct policydb *policydb, 270 struct context *scontext, 271 struct context *tcontext, 272 struct context *xcontext, 273 struct constraint_expr *cexpr) 274 { 275 u32 val1, val2; 276 struct context *c; 277 struct role_datum *r1, *r2; 278 struct mls_level *l1, *l2; 279 struct constraint_expr *e; 280 int s[CEXPR_MAXDEPTH]; 281 int sp = -1; 282 283 for (e = cexpr; e; e = e->next) { 284 switch (e->expr_type) { 285 case CEXPR_NOT: 286 BUG_ON(sp < 0); 287 s[sp] = !s[sp]; 288 break; 289 case CEXPR_AND: 290 BUG_ON(sp < 1); 291 sp--; 292 s[sp] &= s[sp + 1]; 293 break; 294 case CEXPR_OR: 295 BUG_ON(sp < 1); 296 sp--; 297 s[sp] |= s[sp + 1]; 298 break; 299 case CEXPR_ATTR: 300 if (sp == (CEXPR_MAXDEPTH - 1)) 301 return 0; 302 switch (e->attr) { 303 case CEXPR_USER: 304 val1 = scontext->user; 305 val2 = tcontext->user; 306 break; 307 case CEXPR_TYPE: 308 val1 = scontext->type; 309 val2 = tcontext->type; 310 break; 311 case CEXPR_ROLE: 312 val1 = scontext->role; 313 val2 = tcontext->role; 314 r1 = policydb->role_val_to_struct[val1 - 1]; 315 r2 = policydb->role_val_to_struct[val2 - 1]; 316 switch (e->op) { 317 case CEXPR_DOM: 318 s[++sp] = ebitmap_get_bit(&r1->dominates, 319 val2 - 1); 320 continue; 321 case CEXPR_DOMBY: 322 s[++sp] = ebitmap_get_bit(&r2->dominates, 323 val1 - 1); 324 continue; 325 case CEXPR_INCOMP: 326 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 327 val2 - 1) && 328 !ebitmap_get_bit(&r2->dominates, 329 val1 - 1)); 330 continue; 331 default: 332 break; 333 } 334 break; 335 case CEXPR_L1L2: 336 l1 = &(scontext->range.level[0]); 337 l2 = &(tcontext->range.level[0]); 338 goto mls_ops; 339 case CEXPR_L1H2: 340 l1 = &(scontext->range.level[0]); 341 l2 = &(tcontext->range.level[1]); 342 goto mls_ops; 343 case CEXPR_H1L2: 344 l1 = &(scontext->range.level[1]); 345 l2 = &(tcontext->range.level[0]); 346 goto mls_ops; 347 case CEXPR_H1H2: 348 l1 = &(scontext->range.level[1]); 349 l2 = &(tcontext->range.level[1]); 350 goto mls_ops; 351 case CEXPR_L1H1: 352 l1 = &(scontext->range.level[0]); 353 l2 = &(scontext->range.level[1]); 354 goto mls_ops; 355 case CEXPR_L2H2: 356 l1 = &(tcontext->range.level[0]); 357 l2 = &(tcontext->range.level[1]); 358 goto mls_ops; 359 mls_ops: 360 switch (e->op) { 361 case CEXPR_EQ: 362 s[++sp] = mls_level_eq(l1, l2); 363 continue; 364 case CEXPR_NEQ: 365 s[++sp] = !mls_level_eq(l1, l2); 366 continue; 367 case CEXPR_DOM: 368 s[++sp] = mls_level_dom(l1, l2); 369 continue; 370 case CEXPR_DOMBY: 371 s[++sp] = mls_level_dom(l2, l1); 372 continue; 373 case CEXPR_INCOMP: 374 s[++sp] = mls_level_incomp(l2, l1); 375 continue; 376 default: 377 BUG(); 378 return 0; 379 } 380 break; 381 default: 382 BUG(); 383 return 0; 384 } 385 386 switch (e->op) { 387 case CEXPR_EQ: 388 s[++sp] = (val1 == val2); 389 break; 390 case CEXPR_NEQ: 391 s[++sp] = (val1 != val2); 392 break; 393 default: 394 BUG(); 395 return 0; 396 } 397 break; 398 case CEXPR_NAMES: 399 if (sp == (CEXPR_MAXDEPTH-1)) 400 return 0; 401 c = scontext; 402 if (e->attr & CEXPR_TARGET) 403 c = tcontext; 404 else if (e->attr & CEXPR_XTARGET) { 405 c = xcontext; 406 if (!c) { 407 BUG(); 408 return 0; 409 } 410 } 411 if (e->attr & CEXPR_USER) 412 val1 = c->user; 413 else if (e->attr & CEXPR_ROLE) 414 val1 = c->role; 415 else if (e->attr & CEXPR_TYPE) 416 val1 = c->type; 417 else { 418 BUG(); 419 return 0; 420 } 421 422 switch (e->op) { 423 case CEXPR_EQ: 424 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 425 break; 426 case CEXPR_NEQ: 427 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 428 break; 429 default: 430 BUG(); 431 return 0; 432 } 433 break; 434 default: 435 BUG(); 436 return 0; 437 } 438 } 439 440 BUG_ON(sp != 0); 441 return s[0]; 442 } 443 444 /* 445 * security_dump_masked_av - dumps masked permissions during 446 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 447 */ 448 static int dump_masked_av_helper(void *k, void *d, void *args) 449 { 450 struct perm_datum *pdatum = d; 451 char **permission_names = args; 452 453 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 454 455 permission_names[pdatum->value - 1] = (char *)k; 456 457 return 0; 458 } 459 460 static void security_dump_masked_av(struct policydb *policydb, 461 struct context *scontext, 462 struct context *tcontext, 463 u16 tclass, 464 u32 permissions, 465 const char *reason) 466 { 467 struct common_datum *common_dat; 468 struct class_datum *tclass_dat; 469 struct audit_buffer *ab; 470 char *tclass_name; 471 char *scontext_name = NULL; 472 char *tcontext_name = NULL; 473 char *permission_names[32]; 474 int index; 475 u32 length; 476 bool need_comma = false; 477 478 if (!permissions) 479 return; 480 481 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); 482 tclass_dat = policydb->class_val_to_struct[tclass - 1]; 483 common_dat = tclass_dat->comdatum; 484 485 /* init permission_names */ 486 if (common_dat && 487 hashtab_map(&common_dat->permissions.table, 488 dump_masked_av_helper, permission_names) < 0) 489 goto out; 490 491 if (hashtab_map(&tclass_dat->permissions.table, 492 dump_masked_av_helper, permission_names) < 0) 493 goto out; 494 495 /* get scontext/tcontext in text form */ 496 if (context_struct_to_string(policydb, scontext, 497 &scontext_name, &length) < 0) 498 goto out; 499 500 if (context_struct_to_string(policydb, tcontext, 501 &tcontext_name, &length) < 0) 502 goto out; 503 504 /* audit a message */ 505 ab = audit_log_start(audit_context(), 506 GFP_ATOMIC, AUDIT_SELINUX_ERR); 507 if (!ab) 508 goto out; 509 510 audit_log_format(ab, "op=security_compute_av reason=%s " 511 "scontext=%s tcontext=%s tclass=%s perms=", 512 reason, scontext_name, tcontext_name, tclass_name); 513 514 for (index = 0; index < 32; index++) { 515 u32 mask = (1 << index); 516 517 if ((mask & permissions) == 0) 518 continue; 519 520 audit_log_format(ab, "%s%s", 521 need_comma ? "," : "", 522 permission_names[index] 523 ? permission_names[index] : "????"); 524 need_comma = true; 525 } 526 audit_log_end(ab); 527 out: 528 /* release scontext/tcontext */ 529 kfree(tcontext_name); 530 kfree(scontext_name); 531 532 return; 533 } 534 535 /* 536 * security_boundary_permission - drops violated permissions 537 * on boundary constraint. 538 */ 539 static void type_attribute_bounds_av(struct policydb *policydb, 540 struct context *scontext, 541 struct context *tcontext, 542 u16 tclass, 543 struct av_decision *avd) 544 { 545 struct context lo_scontext; 546 struct context lo_tcontext, *tcontextp = tcontext; 547 struct av_decision lo_avd; 548 struct type_datum *source; 549 struct type_datum *target; 550 u32 masked = 0; 551 552 source = policydb->type_val_to_struct[scontext->type - 1]; 553 BUG_ON(!source); 554 555 if (!source->bounds) 556 return; 557 558 target = policydb->type_val_to_struct[tcontext->type - 1]; 559 BUG_ON(!target); 560 561 memset(&lo_avd, 0, sizeof(lo_avd)); 562 563 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 564 lo_scontext.type = source->bounds; 565 566 if (target->bounds) { 567 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 568 lo_tcontext.type = target->bounds; 569 tcontextp = &lo_tcontext; 570 } 571 572 context_struct_compute_av(policydb, &lo_scontext, 573 tcontextp, 574 tclass, 575 &lo_avd, 576 NULL); 577 578 masked = ~lo_avd.allowed & avd->allowed; 579 580 if (likely(!masked)) 581 return; /* no masked permission */ 582 583 /* mask violated permissions */ 584 avd->allowed &= ~masked; 585 586 /* audit masked permissions */ 587 security_dump_masked_av(policydb, scontext, tcontext, 588 tclass, masked, "bounds"); 589 } 590 591 /* 592 * flag which drivers have permissions 593 * only looking for ioctl based extended permssions 594 */ 595 void services_compute_xperms_drivers( 596 struct extended_perms *xperms, 597 struct avtab_node *node) 598 { 599 unsigned int i; 600 601 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 602 /* if one or more driver has all permissions allowed */ 603 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 604 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 605 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 606 /* if allowing permissions within a driver */ 607 security_xperm_set(xperms->drivers.p, 608 node->datum.u.xperms->driver); 609 } 610 611 xperms->len = 1; 612 } 613 614 /* 615 * Compute access vectors and extended permissions based on a context 616 * structure pair for the permissions in a particular class. 617 */ 618 static void context_struct_compute_av(struct policydb *policydb, 619 struct context *scontext, 620 struct context *tcontext, 621 u16 tclass, 622 struct av_decision *avd, 623 struct extended_perms *xperms) 624 { 625 struct constraint_node *constraint; 626 struct role_allow *ra; 627 struct avtab_key avkey; 628 struct avtab_node *node; 629 struct class_datum *tclass_datum; 630 struct ebitmap *sattr, *tattr; 631 struct ebitmap_node *snode, *tnode; 632 unsigned int i, j; 633 634 avd->allowed = 0; 635 avd->auditallow = 0; 636 avd->auditdeny = 0xffffffff; 637 if (xperms) { 638 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 639 xperms->len = 0; 640 } 641 642 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 643 if (printk_ratelimit()) 644 pr_warn("SELinux: Invalid class %hu\n", tclass); 645 return; 646 } 647 648 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 649 650 /* 651 * If a specific type enforcement rule was defined for 652 * this permission check, then use it. 653 */ 654 avkey.target_class = tclass; 655 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 656 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 657 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 658 ebitmap_for_each_positive_bit(sattr, snode, i) { 659 ebitmap_for_each_positive_bit(tattr, tnode, j) { 660 avkey.source_type = i + 1; 661 avkey.target_type = j + 1; 662 for (node = avtab_search_node(&policydb->te_avtab, 663 &avkey); 664 node; 665 node = avtab_search_node_next(node, avkey.specified)) { 666 if (node->key.specified == AVTAB_ALLOWED) 667 avd->allowed |= node->datum.u.data; 668 else if (node->key.specified == AVTAB_AUDITALLOW) 669 avd->auditallow |= node->datum.u.data; 670 else if (node->key.specified == AVTAB_AUDITDENY) 671 avd->auditdeny &= node->datum.u.data; 672 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 673 services_compute_xperms_drivers(xperms, node); 674 } 675 676 /* Check conditional av table for additional permissions */ 677 cond_compute_av(&policydb->te_cond_avtab, &avkey, 678 avd, xperms); 679 680 } 681 } 682 683 /* 684 * Remove any permissions prohibited by a constraint (this includes 685 * the MLS policy). 686 */ 687 constraint = tclass_datum->constraints; 688 while (constraint) { 689 if ((constraint->permissions & (avd->allowed)) && 690 !constraint_expr_eval(policydb, scontext, tcontext, NULL, 691 constraint->expr)) { 692 avd->allowed &= ~(constraint->permissions); 693 } 694 constraint = constraint->next; 695 } 696 697 /* 698 * If checking process transition permission and the 699 * role is changing, then check the (current_role, new_role) 700 * pair. 701 */ 702 if (tclass == policydb->process_class && 703 (avd->allowed & policydb->process_trans_perms) && 704 scontext->role != tcontext->role) { 705 for (ra = policydb->role_allow; ra; ra = ra->next) { 706 if (scontext->role == ra->role && 707 tcontext->role == ra->new_role) 708 break; 709 } 710 if (!ra) 711 avd->allowed &= ~policydb->process_trans_perms; 712 } 713 714 /* 715 * If the given source and target types have boundary 716 * constraint, lazy checks have to mask any violated 717 * permission and notice it to userspace via audit. 718 */ 719 type_attribute_bounds_av(policydb, scontext, tcontext, 720 tclass, avd); 721 } 722 723 static int security_validtrans_handle_fail(struct selinux_state *state, 724 struct selinux_policy *policy, 725 struct sidtab_entry *oentry, 726 struct sidtab_entry *nentry, 727 struct sidtab_entry *tentry, 728 u16 tclass) 729 { 730 struct policydb *p = &policy->policydb; 731 struct sidtab *sidtab = policy->sidtab; 732 char *o = NULL, *n = NULL, *t = NULL; 733 u32 olen, nlen, tlen; 734 735 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) 736 goto out; 737 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) 738 goto out; 739 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) 740 goto out; 741 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 742 "op=security_validate_transition seresult=denied" 743 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 744 o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); 745 out: 746 kfree(o); 747 kfree(n); 748 kfree(t); 749 750 if (!enforcing_enabled(state)) 751 return 0; 752 return -EPERM; 753 } 754 755 static int security_compute_validatetrans(struct selinux_state *state, 756 u32 oldsid, u32 newsid, u32 tasksid, 757 u16 orig_tclass, bool user) 758 { 759 struct selinux_policy *policy; 760 struct policydb *policydb; 761 struct sidtab *sidtab; 762 struct sidtab_entry *oentry; 763 struct sidtab_entry *nentry; 764 struct sidtab_entry *tentry; 765 struct class_datum *tclass_datum; 766 struct constraint_node *constraint; 767 u16 tclass; 768 int rc = 0; 769 770 771 if (!selinux_initialized(state)) 772 return 0; 773 774 rcu_read_lock(); 775 776 policy = rcu_dereference(state->policy); 777 policydb = &policy->policydb; 778 sidtab = policy->sidtab; 779 780 if (!user) 781 tclass = unmap_class(&policy->map, orig_tclass); 782 else 783 tclass = orig_tclass; 784 785 if (!tclass || tclass > policydb->p_classes.nprim) { 786 rc = -EINVAL; 787 goto out; 788 } 789 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 790 791 oentry = sidtab_search_entry(sidtab, oldsid); 792 if (!oentry) { 793 pr_err("SELinux: %s: unrecognized SID %d\n", 794 __func__, oldsid); 795 rc = -EINVAL; 796 goto out; 797 } 798 799 nentry = sidtab_search_entry(sidtab, newsid); 800 if (!nentry) { 801 pr_err("SELinux: %s: unrecognized SID %d\n", 802 __func__, newsid); 803 rc = -EINVAL; 804 goto out; 805 } 806 807 tentry = sidtab_search_entry(sidtab, tasksid); 808 if (!tentry) { 809 pr_err("SELinux: %s: unrecognized SID %d\n", 810 __func__, tasksid); 811 rc = -EINVAL; 812 goto out; 813 } 814 815 constraint = tclass_datum->validatetrans; 816 while (constraint) { 817 if (!constraint_expr_eval(policydb, &oentry->context, 818 &nentry->context, &tentry->context, 819 constraint->expr)) { 820 if (user) 821 rc = -EPERM; 822 else 823 rc = security_validtrans_handle_fail(state, 824 policy, 825 oentry, 826 nentry, 827 tentry, 828 tclass); 829 goto out; 830 } 831 constraint = constraint->next; 832 } 833 834 out: 835 rcu_read_unlock(); 836 return rc; 837 } 838 839 int security_validate_transition_user(struct selinux_state *state, 840 u32 oldsid, u32 newsid, u32 tasksid, 841 u16 tclass) 842 { 843 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 844 tclass, true); 845 } 846 847 int security_validate_transition(struct selinux_state *state, 848 u32 oldsid, u32 newsid, u32 tasksid, 849 u16 orig_tclass) 850 { 851 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 852 orig_tclass, false); 853 } 854 855 /* 856 * security_bounded_transition - check whether the given 857 * transition is directed to bounded, or not. 858 * It returns 0, if @newsid is bounded by @oldsid. 859 * Otherwise, it returns error code. 860 * 861 * @oldsid : current security identifier 862 * @newsid : destinated security identifier 863 */ 864 int security_bounded_transition(struct selinux_state *state, 865 u32 old_sid, u32 new_sid) 866 { 867 struct selinux_policy *policy; 868 struct policydb *policydb; 869 struct sidtab *sidtab; 870 struct sidtab_entry *old_entry, *new_entry; 871 struct type_datum *type; 872 int index; 873 int rc; 874 875 if (!selinux_initialized(state)) 876 return 0; 877 878 rcu_read_lock(); 879 policy = rcu_dereference(state->policy); 880 policydb = &policy->policydb; 881 sidtab = policy->sidtab; 882 883 rc = -EINVAL; 884 old_entry = sidtab_search_entry(sidtab, old_sid); 885 if (!old_entry) { 886 pr_err("SELinux: %s: unrecognized SID %u\n", 887 __func__, old_sid); 888 goto out; 889 } 890 891 rc = -EINVAL; 892 new_entry = sidtab_search_entry(sidtab, new_sid); 893 if (!new_entry) { 894 pr_err("SELinux: %s: unrecognized SID %u\n", 895 __func__, new_sid); 896 goto out; 897 } 898 899 rc = 0; 900 /* type/domain unchanged */ 901 if (old_entry->context.type == new_entry->context.type) 902 goto out; 903 904 index = new_entry->context.type; 905 while (true) { 906 type = policydb->type_val_to_struct[index - 1]; 907 BUG_ON(!type); 908 909 /* not bounded anymore */ 910 rc = -EPERM; 911 if (!type->bounds) 912 break; 913 914 /* @newsid is bounded by @oldsid */ 915 rc = 0; 916 if (type->bounds == old_entry->context.type) 917 break; 918 919 index = type->bounds; 920 } 921 922 if (rc) { 923 char *old_name = NULL; 924 char *new_name = NULL; 925 u32 length; 926 927 if (!sidtab_entry_to_string(policydb, sidtab, old_entry, 928 &old_name, &length) && 929 !sidtab_entry_to_string(policydb, sidtab, new_entry, 930 &new_name, &length)) { 931 audit_log(audit_context(), 932 GFP_ATOMIC, AUDIT_SELINUX_ERR, 933 "op=security_bounded_transition " 934 "seresult=denied " 935 "oldcontext=%s newcontext=%s", 936 old_name, new_name); 937 } 938 kfree(new_name); 939 kfree(old_name); 940 } 941 out: 942 rcu_read_unlock(); 943 944 return rc; 945 } 946 947 static void avd_init(struct selinux_policy *policy, struct av_decision *avd) 948 { 949 avd->allowed = 0; 950 avd->auditallow = 0; 951 avd->auditdeny = 0xffffffff; 952 if (policy) 953 avd->seqno = policy->latest_granting; 954 else 955 avd->seqno = 0; 956 avd->flags = 0; 957 } 958 959 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 960 struct avtab_node *node) 961 { 962 unsigned int i; 963 964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 965 if (xpermd->driver != node->datum.u.xperms->driver) 966 return; 967 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 968 if (!security_xperm_test(node->datum.u.xperms->perms.p, 969 xpermd->driver)) 970 return; 971 } else { 972 BUG(); 973 } 974 975 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 976 xpermd->used |= XPERMS_ALLOWED; 977 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 978 memset(xpermd->allowed->p, 0xff, 979 sizeof(xpermd->allowed->p)); 980 } 981 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 982 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 983 xpermd->allowed->p[i] |= 984 node->datum.u.xperms->perms.p[i]; 985 } 986 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 987 xpermd->used |= XPERMS_AUDITALLOW; 988 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 989 memset(xpermd->auditallow->p, 0xff, 990 sizeof(xpermd->auditallow->p)); 991 } 992 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 993 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 994 xpermd->auditallow->p[i] |= 995 node->datum.u.xperms->perms.p[i]; 996 } 997 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 998 xpermd->used |= XPERMS_DONTAUDIT; 999 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 1000 memset(xpermd->dontaudit->p, 0xff, 1001 sizeof(xpermd->dontaudit->p)); 1002 } 1003 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 1004 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 1005 xpermd->dontaudit->p[i] |= 1006 node->datum.u.xperms->perms.p[i]; 1007 } 1008 } else { 1009 BUG(); 1010 } 1011 } 1012 1013 void security_compute_xperms_decision(struct selinux_state *state, 1014 u32 ssid, 1015 u32 tsid, 1016 u16 orig_tclass, 1017 u8 driver, 1018 struct extended_perms_decision *xpermd) 1019 { 1020 struct selinux_policy *policy; 1021 struct policydb *policydb; 1022 struct sidtab *sidtab; 1023 u16 tclass; 1024 struct context *scontext, *tcontext; 1025 struct avtab_key avkey; 1026 struct avtab_node *node; 1027 struct ebitmap *sattr, *tattr; 1028 struct ebitmap_node *snode, *tnode; 1029 unsigned int i, j; 1030 1031 xpermd->driver = driver; 1032 xpermd->used = 0; 1033 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1034 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1035 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1036 1037 rcu_read_lock(); 1038 if (!selinux_initialized(state)) 1039 goto allow; 1040 1041 policy = rcu_dereference(state->policy); 1042 policydb = &policy->policydb; 1043 sidtab = policy->sidtab; 1044 1045 scontext = sidtab_search(sidtab, ssid); 1046 if (!scontext) { 1047 pr_err("SELinux: %s: unrecognized SID %d\n", 1048 __func__, ssid); 1049 goto out; 1050 } 1051 1052 tcontext = sidtab_search(sidtab, tsid); 1053 if (!tcontext) { 1054 pr_err("SELinux: %s: unrecognized SID %d\n", 1055 __func__, tsid); 1056 goto out; 1057 } 1058 1059 tclass = unmap_class(&policy->map, orig_tclass); 1060 if (unlikely(orig_tclass && !tclass)) { 1061 if (policydb->allow_unknown) 1062 goto allow; 1063 goto out; 1064 } 1065 1066 1067 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1068 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1069 goto out; 1070 } 1071 1072 avkey.target_class = tclass; 1073 avkey.specified = AVTAB_XPERMS; 1074 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 1075 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 1076 ebitmap_for_each_positive_bit(sattr, snode, i) { 1077 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1078 avkey.source_type = i + 1; 1079 avkey.target_type = j + 1; 1080 for (node = avtab_search_node(&policydb->te_avtab, 1081 &avkey); 1082 node; 1083 node = avtab_search_node_next(node, avkey.specified)) 1084 services_compute_xperms_decision(xpermd, node); 1085 1086 cond_compute_xperms(&policydb->te_cond_avtab, 1087 &avkey, xpermd); 1088 } 1089 } 1090 out: 1091 rcu_read_unlock(); 1092 return; 1093 allow: 1094 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1095 goto out; 1096 } 1097 1098 /** 1099 * security_compute_av - Compute access vector decisions. 1100 * @ssid: source security identifier 1101 * @tsid: target security identifier 1102 * @tclass: target security class 1103 * @avd: access vector decisions 1104 * @xperms: extended permissions 1105 * 1106 * Compute a set of access vector decisions based on the 1107 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1108 */ 1109 void security_compute_av(struct selinux_state *state, 1110 u32 ssid, 1111 u32 tsid, 1112 u16 orig_tclass, 1113 struct av_decision *avd, 1114 struct extended_perms *xperms) 1115 { 1116 struct selinux_policy *policy; 1117 struct policydb *policydb; 1118 struct sidtab *sidtab; 1119 u16 tclass; 1120 struct context *scontext = NULL, *tcontext = NULL; 1121 1122 rcu_read_lock(); 1123 policy = rcu_dereference(state->policy); 1124 avd_init(policy, avd); 1125 xperms->len = 0; 1126 if (!selinux_initialized(state)) 1127 goto allow; 1128 1129 policydb = &policy->policydb; 1130 sidtab = policy->sidtab; 1131 1132 scontext = sidtab_search(sidtab, ssid); 1133 if (!scontext) { 1134 pr_err("SELinux: %s: unrecognized SID %d\n", 1135 __func__, ssid); 1136 goto out; 1137 } 1138 1139 /* permissive domain? */ 1140 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1141 avd->flags |= AVD_FLAGS_PERMISSIVE; 1142 1143 tcontext = sidtab_search(sidtab, tsid); 1144 if (!tcontext) { 1145 pr_err("SELinux: %s: unrecognized SID %d\n", 1146 __func__, tsid); 1147 goto out; 1148 } 1149 1150 tclass = unmap_class(&policy->map, orig_tclass); 1151 if (unlikely(orig_tclass && !tclass)) { 1152 if (policydb->allow_unknown) 1153 goto allow; 1154 goto out; 1155 } 1156 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1157 xperms); 1158 map_decision(&policy->map, orig_tclass, avd, 1159 policydb->allow_unknown); 1160 out: 1161 rcu_read_unlock(); 1162 return; 1163 allow: 1164 avd->allowed = 0xffffffff; 1165 goto out; 1166 } 1167 1168 void security_compute_av_user(struct selinux_state *state, 1169 u32 ssid, 1170 u32 tsid, 1171 u16 tclass, 1172 struct av_decision *avd) 1173 { 1174 struct selinux_policy *policy; 1175 struct policydb *policydb; 1176 struct sidtab *sidtab; 1177 struct context *scontext = NULL, *tcontext = NULL; 1178 1179 rcu_read_lock(); 1180 policy = rcu_dereference(state->policy); 1181 avd_init(policy, avd); 1182 if (!selinux_initialized(state)) 1183 goto allow; 1184 1185 policydb = &policy->policydb; 1186 sidtab = policy->sidtab; 1187 1188 scontext = sidtab_search(sidtab, ssid); 1189 if (!scontext) { 1190 pr_err("SELinux: %s: unrecognized SID %d\n", 1191 __func__, ssid); 1192 goto out; 1193 } 1194 1195 /* permissive domain? */ 1196 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1197 avd->flags |= AVD_FLAGS_PERMISSIVE; 1198 1199 tcontext = sidtab_search(sidtab, tsid); 1200 if (!tcontext) { 1201 pr_err("SELinux: %s: unrecognized SID %d\n", 1202 __func__, tsid); 1203 goto out; 1204 } 1205 1206 if (unlikely(!tclass)) { 1207 if (policydb->allow_unknown) 1208 goto allow; 1209 goto out; 1210 } 1211 1212 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1213 NULL); 1214 out: 1215 rcu_read_unlock(); 1216 return; 1217 allow: 1218 avd->allowed = 0xffffffff; 1219 goto out; 1220 } 1221 1222 /* 1223 * Write the security context string representation of 1224 * the context structure `context' into a dynamically 1225 * allocated string of the correct size. Set `*scontext' 1226 * to point to this string and set `*scontext_len' to 1227 * the length of the string. 1228 */ 1229 static int context_struct_to_string(struct policydb *p, 1230 struct context *context, 1231 char **scontext, u32 *scontext_len) 1232 { 1233 char *scontextp; 1234 1235 if (scontext) 1236 *scontext = NULL; 1237 *scontext_len = 0; 1238 1239 if (context->len) { 1240 *scontext_len = context->len; 1241 if (scontext) { 1242 *scontext = kstrdup(context->str, GFP_ATOMIC); 1243 if (!(*scontext)) 1244 return -ENOMEM; 1245 } 1246 return 0; 1247 } 1248 1249 /* Compute the size of the context. */ 1250 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1251 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1252 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1253 *scontext_len += mls_compute_context_len(p, context); 1254 1255 if (!scontext) 1256 return 0; 1257 1258 /* Allocate space for the context; caller must free this space. */ 1259 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1260 if (!scontextp) 1261 return -ENOMEM; 1262 *scontext = scontextp; 1263 1264 /* 1265 * Copy the user name, role name and type name into the context. 1266 */ 1267 scontextp += sprintf(scontextp, "%s:%s:%s", 1268 sym_name(p, SYM_USERS, context->user - 1), 1269 sym_name(p, SYM_ROLES, context->role - 1), 1270 sym_name(p, SYM_TYPES, context->type - 1)); 1271 1272 mls_sid_to_context(p, context, &scontextp); 1273 1274 *scontextp = 0; 1275 1276 return 0; 1277 } 1278 1279 static int sidtab_entry_to_string(struct policydb *p, 1280 struct sidtab *sidtab, 1281 struct sidtab_entry *entry, 1282 char **scontext, u32 *scontext_len) 1283 { 1284 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); 1285 1286 if (rc != -ENOENT) 1287 return rc; 1288 1289 rc = context_struct_to_string(p, &entry->context, scontext, 1290 scontext_len); 1291 if (!rc && scontext) 1292 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); 1293 return rc; 1294 } 1295 1296 #include "initial_sid_to_string.h" 1297 1298 int security_sidtab_hash_stats(struct selinux_state *state, char *page) 1299 { 1300 struct selinux_policy *policy; 1301 int rc; 1302 1303 if (!selinux_initialized(state)) { 1304 pr_err("SELinux: %s: called before initial load_policy\n", 1305 __func__); 1306 return -EINVAL; 1307 } 1308 1309 rcu_read_lock(); 1310 policy = rcu_dereference(state->policy); 1311 rc = sidtab_hash_stats(policy->sidtab, page); 1312 rcu_read_unlock(); 1313 1314 return rc; 1315 } 1316 1317 const char *security_get_initial_sid_context(u32 sid) 1318 { 1319 if (unlikely(sid > SECINITSID_NUM)) 1320 return NULL; 1321 return initial_sid_to_string[sid]; 1322 } 1323 1324 static int security_sid_to_context_core(struct selinux_state *state, 1325 u32 sid, char **scontext, 1326 u32 *scontext_len, int force, 1327 int only_invalid) 1328 { 1329 struct selinux_policy *policy; 1330 struct policydb *policydb; 1331 struct sidtab *sidtab; 1332 struct sidtab_entry *entry; 1333 int rc = 0; 1334 1335 if (scontext) 1336 *scontext = NULL; 1337 *scontext_len = 0; 1338 1339 if (!selinux_initialized(state)) { 1340 if (sid <= SECINITSID_NUM) { 1341 char *scontextp; 1342 const char *s = initial_sid_to_string[sid]; 1343 1344 if (!s) 1345 return -EINVAL; 1346 *scontext_len = strlen(s) + 1; 1347 if (!scontext) 1348 return 0; 1349 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1350 if (!scontextp) 1351 return -ENOMEM; 1352 *scontext = scontextp; 1353 return 0; 1354 } 1355 pr_err("SELinux: %s: called before initial " 1356 "load_policy on unknown SID %d\n", __func__, sid); 1357 return -EINVAL; 1358 } 1359 rcu_read_lock(); 1360 policy = rcu_dereference(state->policy); 1361 policydb = &policy->policydb; 1362 sidtab = policy->sidtab; 1363 1364 if (force) 1365 entry = sidtab_search_entry_force(sidtab, sid); 1366 else 1367 entry = sidtab_search_entry(sidtab, sid); 1368 if (!entry) { 1369 pr_err("SELinux: %s: unrecognized SID %d\n", 1370 __func__, sid); 1371 rc = -EINVAL; 1372 goto out_unlock; 1373 } 1374 if (only_invalid && !entry->context.len) 1375 goto out_unlock; 1376 1377 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1378 scontext_len); 1379 1380 out_unlock: 1381 rcu_read_unlock(); 1382 return rc; 1383 1384 } 1385 1386 /** 1387 * security_sid_to_context - Obtain a context for a given SID. 1388 * @sid: security identifier, SID 1389 * @scontext: security context 1390 * @scontext_len: length in bytes 1391 * 1392 * Write the string representation of the context associated with @sid 1393 * into a dynamically allocated string of the correct size. Set @scontext 1394 * to point to this string and set @scontext_len to the length of the string. 1395 */ 1396 int security_sid_to_context(struct selinux_state *state, 1397 u32 sid, char **scontext, u32 *scontext_len) 1398 { 1399 return security_sid_to_context_core(state, sid, scontext, 1400 scontext_len, 0, 0); 1401 } 1402 1403 int security_sid_to_context_force(struct selinux_state *state, u32 sid, 1404 char **scontext, u32 *scontext_len) 1405 { 1406 return security_sid_to_context_core(state, sid, scontext, 1407 scontext_len, 1, 0); 1408 } 1409 1410 /** 1411 * security_sid_to_context_inval - Obtain a context for a given SID if it 1412 * is invalid. 1413 * @sid: security identifier, SID 1414 * @scontext: security context 1415 * @scontext_len: length in bytes 1416 * 1417 * Write the string representation of the context associated with @sid 1418 * into a dynamically allocated string of the correct size, but only if the 1419 * context is invalid in the current policy. Set @scontext to point to 1420 * this string (or NULL if the context is valid) and set @scontext_len to 1421 * the length of the string (or 0 if the context is valid). 1422 */ 1423 int security_sid_to_context_inval(struct selinux_state *state, u32 sid, 1424 char **scontext, u32 *scontext_len) 1425 { 1426 return security_sid_to_context_core(state, sid, scontext, 1427 scontext_len, 1, 1); 1428 } 1429 1430 /* 1431 * Caveat: Mutates scontext. 1432 */ 1433 static int string_to_context_struct(struct policydb *pol, 1434 struct sidtab *sidtabp, 1435 char *scontext, 1436 struct context *ctx, 1437 u32 def_sid) 1438 { 1439 struct role_datum *role; 1440 struct type_datum *typdatum; 1441 struct user_datum *usrdatum; 1442 char *scontextp, *p, oldc; 1443 int rc = 0; 1444 1445 context_init(ctx); 1446 1447 /* Parse the security context. */ 1448 1449 rc = -EINVAL; 1450 scontextp = (char *) scontext; 1451 1452 /* Extract the user. */ 1453 p = scontextp; 1454 while (*p && *p != ':') 1455 p++; 1456 1457 if (*p == 0) 1458 goto out; 1459 1460 *p++ = 0; 1461 1462 usrdatum = symtab_search(&pol->p_users, scontextp); 1463 if (!usrdatum) 1464 goto out; 1465 1466 ctx->user = usrdatum->value; 1467 1468 /* Extract role. */ 1469 scontextp = p; 1470 while (*p && *p != ':') 1471 p++; 1472 1473 if (*p == 0) 1474 goto out; 1475 1476 *p++ = 0; 1477 1478 role = symtab_search(&pol->p_roles, scontextp); 1479 if (!role) 1480 goto out; 1481 ctx->role = role->value; 1482 1483 /* Extract type. */ 1484 scontextp = p; 1485 while (*p && *p != ':') 1486 p++; 1487 oldc = *p; 1488 *p++ = 0; 1489 1490 typdatum = symtab_search(&pol->p_types, scontextp); 1491 if (!typdatum || typdatum->attribute) 1492 goto out; 1493 1494 ctx->type = typdatum->value; 1495 1496 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1497 if (rc) 1498 goto out; 1499 1500 /* Check the validity of the new context. */ 1501 rc = -EINVAL; 1502 if (!policydb_context_isvalid(pol, ctx)) 1503 goto out; 1504 rc = 0; 1505 out: 1506 if (rc) 1507 context_destroy(ctx); 1508 return rc; 1509 } 1510 1511 static int security_context_to_sid_core(struct selinux_state *state, 1512 const char *scontext, u32 scontext_len, 1513 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1514 int force) 1515 { 1516 struct selinux_policy *policy; 1517 struct policydb *policydb; 1518 struct sidtab *sidtab; 1519 char *scontext2, *str = NULL; 1520 struct context context; 1521 int rc = 0; 1522 1523 /* An empty security context is never valid. */ 1524 if (!scontext_len) 1525 return -EINVAL; 1526 1527 /* Copy the string to allow changes and ensure a NUL terminator */ 1528 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1529 if (!scontext2) 1530 return -ENOMEM; 1531 1532 if (!selinux_initialized(state)) { 1533 int i; 1534 1535 for (i = 1; i < SECINITSID_NUM; i++) { 1536 const char *s = initial_sid_to_string[i]; 1537 1538 if (s && !strcmp(s, scontext2)) { 1539 *sid = i; 1540 goto out; 1541 } 1542 } 1543 *sid = SECINITSID_KERNEL; 1544 goto out; 1545 } 1546 *sid = SECSID_NULL; 1547 1548 if (force) { 1549 /* Save another copy for storing in uninterpreted form */ 1550 rc = -ENOMEM; 1551 str = kstrdup(scontext2, gfp_flags); 1552 if (!str) 1553 goto out; 1554 } 1555 retry: 1556 rcu_read_lock(); 1557 policy = rcu_dereference(state->policy); 1558 policydb = &policy->policydb; 1559 sidtab = policy->sidtab; 1560 rc = string_to_context_struct(policydb, sidtab, scontext2, 1561 &context, def_sid); 1562 if (rc == -EINVAL && force) { 1563 context.str = str; 1564 context.len = strlen(str) + 1; 1565 str = NULL; 1566 } else if (rc) 1567 goto out_unlock; 1568 rc = sidtab_context_to_sid(sidtab, &context, sid); 1569 if (rc == -ESTALE) { 1570 rcu_read_unlock(); 1571 if (context.str) { 1572 str = context.str; 1573 context.str = NULL; 1574 } 1575 context_destroy(&context); 1576 goto retry; 1577 } 1578 context_destroy(&context); 1579 out_unlock: 1580 rcu_read_unlock(); 1581 out: 1582 kfree(scontext2); 1583 kfree(str); 1584 return rc; 1585 } 1586 1587 /** 1588 * security_context_to_sid - Obtain a SID for a given security context. 1589 * @scontext: security context 1590 * @scontext_len: length in bytes 1591 * @sid: security identifier, SID 1592 * @gfp: context for the allocation 1593 * 1594 * Obtains a SID associated with the security context that 1595 * has the string representation specified by @scontext. 1596 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1597 * memory is available, or 0 on success. 1598 */ 1599 int security_context_to_sid(struct selinux_state *state, 1600 const char *scontext, u32 scontext_len, u32 *sid, 1601 gfp_t gfp) 1602 { 1603 return security_context_to_sid_core(state, scontext, scontext_len, 1604 sid, SECSID_NULL, gfp, 0); 1605 } 1606 1607 int security_context_str_to_sid(struct selinux_state *state, 1608 const char *scontext, u32 *sid, gfp_t gfp) 1609 { 1610 return security_context_to_sid(state, scontext, strlen(scontext), 1611 sid, gfp); 1612 } 1613 1614 /** 1615 * security_context_to_sid_default - Obtain a SID for a given security context, 1616 * falling back to specified default if needed. 1617 * 1618 * @scontext: security context 1619 * @scontext_len: length in bytes 1620 * @sid: security identifier, SID 1621 * @def_sid: default SID to assign on error 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 audit_log_format(ab, 1670 "op=security_compute_sid invalid_context="); 1671 /* no need to record the NUL with untrusted strings */ 1672 audit_log_n_untrustedstring(ab, n, nlen - 1); 1673 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1674 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1675 audit_log_end(ab); 1676 out: 1677 kfree(s); 1678 kfree(t); 1679 kfree(n); 1680 if (!enforcing_enabled(state)) 1681 return 0; 1682 return -EACCES; 1683 } 1684 1685 static void filename_compute_type(struct policydb *policydb, 1686 struct context *newcontext, 1687 u32 stype, u32 ttype, u16 tclass, 1688 const char *objname) 1689 { 1690 struct filename_trans_key ft; 1691 struct filename_trans_datum *datum; 1692 1693 /* 1694 * Most filename trans rules are going to live in specific directories 1695 * like /dev or /var/run. This bitmap will quickly skip rule searches 1696 * if the ttype does not contain any rules. 1697 */ 1698 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1699 return; 1700 1701 ft.ttype = ttype; 1702 ft.tclass = tclass; 1703 ft.name = objname; 1704 1705 datum = policydb_filenametr_search(policydb, &ft); 1706 while (datum) { 1707 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1708 newcontext->type = datum->otype; 1709 return; 1710 } 1711 datum = datum->next; 1712 } 1713 } 1714 1715 static int security_compute_sid(struct selinux_state *state, 1716 u32 ssid, 1717 u32 tsid, 1718 u16 orig_tclass, 1719 u32 specified, 1720 const char *objname, 1721 u32 *out_sid, 1722 bool kern) 1723 { 1724 struct selinux_policy *policy; 1725 struct policydb *policydb; 1726 struct sidtab *sidtab; 1727 struct class_datum *cladatum; 1728 struct context *scontext, *tcontext, newcontext; 1729 struct sidtab_entry *sentry, *tentry; 1730 struct avtab_key avkey; 1731 struct avtab_datum *avdatum; 1732 struct avtab_node *node; 1733 u16 tclass; 1734 int rc = 0; 1735 bool sock; 1736 1737 if (!selinux_initialized(state)) { 1738 switch (orig_tclass) { 1739 case SECCLASS_PROCESS: /* kernel value */ 1740 *out_sid = ssid; 1741 break; 1742 default: 1743 *out_sid = tsid; 1744 break; 1745 } 1746 goto out; 1747 } 1748 1749 retry: 1750 cladatum = NULL; 1751 context_init(&newcontext); 1752 1753 rcu_read_lock(); 1754 1755 policy = rcu_dereference(state->policy); 1756 1757 if (kern) { 1758 tclass = unmap_class(&policy->map, orig_tclass); 1759 sock = security_is_socket_class(orig_tclass); 1760 } else { 1761 tclass = orig_tclass; 1762 sock = security_is_socket_class(map_class(&policy->map, 1763 tclass)); 1764 } 1765 1766 policydb = &policy->policydb; 1767 sidtab = policy->sidtab; 1768 1769 sentry = sidtab_search_entry(sidtab, ssid); 1770 if (!sentry) { 1771 pr_err("SELinux: %s: unrecognized SID %d\n", 1772 __func__, ssid); 1773 rc = -EINVAL; 1774 goto out_unlock; 1775 } 1776 tentry = sidtab_search_entry(sidtab, tsid); 1777 if (!tentry) { 1778 pr_err("SELinux: %s: unrecognized SID %d\n", 1779 __func__, tsid); 1780 rc = -EINVAL; 1781 goto out_unlock; 1782 } 1783 1784 scontext = &sentry->context; 1785 tcontext = &tentry->context; 1786 1787 if (tclass && tclass <= policydb->p_classes.nprim) 1788 cladatum = policydb->class_val_to_struct[tclass - 1]; 1789 1790 /* Set the user identity. */ 1791 switch (specified) { 1792 case AVTAB_TRANSITION: 1793 case AVTAB_CHANGE: 1794 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1795 newcontext.user = tcontext->user; 1796 } else { 1797 /* notice this gets both DEFAULT_SOURCE and unset */ 1798 /* Use the process user identity. */ 1799 newcontext.user = scontext->user; 1800 } 1801 break; 1802 case AVTAB_MEMBER: 1803 /* Use the related object owner. */ 1804 newcontext.user = tcontext->user; 1805 break; 1806 } 1807 1808 /* Set the role to default values. */ 1809 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1810 newcontext.role = scontext->role; 1811 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1812 newcontext.role = tcontext->role; 1813 } else { 1814 if ((tclass == policydb->process_class) || sock) 1815 newcontext.role = scontext->role; 1816 else 1817 newcontext.role = OBJECT_R_VAL; 1818 } 1819 1820 /* Set the type to default values. */ 1821 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1822 newcontext.type = scontext->type; 1823 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1824 newcontext.type = tcontext->type; 1825 } else { 1826 if ((tclass == policydb->process_class) || sock) { 1827 /* Use the type of process. */ 1828 newcontext.type = scontext->type; 1829 } else { 1830 /* Use the type of the related object. */ 1831 newcontext.type = tcontext->type; 1832 } 1833 } 1834 1835 /* Look for a type transition/member/change rule. */ 1836 avkey.source_type = scontext->type; 1837 avkey.target_type = tcontext->type; 1838 avkey.target_class = tclass; 1839 avkey.specified = specified; 1840 avdatum = avtab_search(&policydb->te_avtab, &avkey); 1841 1842 /* If no permanent rule, also check for enabled conditional rules */ 1843 if (!avdatum) { 1844 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1845 for (; node; node = avtab_search_node_next(node, specified)) { 1846 if (node->key.specified & AVTAB_ENABLED) { 1847 avdatum = &node->datum; 1848 break; 1849 } 1850 } 1851 } 1852 1853 if (avdatum) { 1854 /* Use the type from the type transition/member/change rule. */ 1855 newcontext.type = avdatum->u.data; 1856 } 1857 1858 /* if we have a objname this is a file trans check so check those rules */ 1859 if (objname) 1860 filename_compute_type(policydb, &newcontext, scontext->type, 1861 tcontext->type, tclass, objname); 1862 1863 /* Check for class-specific changes. */ 1864 if (specified & AVTAB_TRANSITION) { 1865 /* Look for a role transition rule. */ 1866 struct role_trans_datum *rtd; 1867 struct role_trans_key rtk = { 1868 .role = scontext->role, 1869 .type = tcontext->type, 1870 .tclass = tclass, 1871 }; 1872 1873 rtd = policydb_roletr_search(policydb, &rtk); 1874 if (rtd) 1875 newcontext.role = rtd->new_role; 1876 } 1877 1878 /* Set the MLS attributes. 1879 This is done last because it may allocate memory. */ 1880 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1881 &newcontext, sock); 1882 if (rc) 1883 goto out_unlock; 1884 1885 /* Check the validity of the context. */ 1886 if (!policydb_context_isvalid(policydb, &newcontext)) { 1887 rc = compute_sid_handle_invalid_context(state, policy, sentry, 1888 tentry, tclass, 1889 &newcontext); 1890 if (rc) 1891 goto out_unlock; 1892 } 1893 /* Obtain the sid for the context. */ 1894 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1895 if (rc == -ESTALE) { 1896 rcu_read_unlock(); 1897 context_destroy(&newcontext); 1898 goto retry; 1899 } 1900 out_unlock: 1901 rcu_read_unlock(); 1902 context_destroy(&newcontext); 1903 out: 1904 return rc; 1905 } 1906 1907 /** 1908 * security_transition_sid - Compute the SID for a new subject/object. 1909 * @ssid: source security identifier 1910 * @tsid: target security identifier 1911 * @tclass: target security class 1912 * @out_sid: security identifier for new subject/object 1913 * 1914 * Compute a SID to use for labeling a new subject or object in the 1915 * class @tclass based on a SID pair (@ssid, @tsid). 1916 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1917 * if insufficient memory is available, or %0 if the new SID was 1918 * computed successfully. 1919 */ 1920 int security_transition_sid(struct selinux_state *state, 1921 u32 ssid, u32 tsid, u16 tclass, 1922 const struct qstr *qstr, u32 *out_sid) 1923 { 1924 return security_compute_sid(state, ssid, tsid, tclass, 1925 AVTAB_TRANSITION, 1926 qstr ? qstr->name : NULL, out_sid, true); 1927 } 1928 1929 int security_transition_sid_user(struct selinux_state *state, 1930 u32 ssid, u32 tsid, u16 tclass, 1931 const char *objname, u32 *out_sid) 1932 { 1933 return security_compute_sid(state, ssid, tsid, tclass, 1934 AVTAB_TRANSITION, 1935 objname, out_sid, false); 1936 } 1937 1938 /** 1939 * security_member_sid - Compute the SID for member selection. 1940 * @ssid: source security identifier 1941 * @tsid: target security identifier 1942 * @tclass: target security class 1943 * @out_sid: security identifier for selected member 1944 * 1945 * Compute a SID to use when selecting a member of a polyinstantiated 1946 * object of class @tclass based on a SID pair (@ssid, @tsid). 1947 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1948 * if insufficient memory is available, or %0 if the SID was 1949 * computed successfully. 1950 */ 1951 int security_member_sid(struct selinux_state *state, 1952 u32 ssid, 1953 u32 tsid, 1954 u16 tclass, 1955 u32 *out_sid) 1956 { 1957 return security_compute_sid(state, ssid, tsid, tclass, 1958 AVTAB_MEMBER, NULL, 1959 out_sid, false); 1960 } 1961 1962 /** 1963 * security_change_sid - Compute the SID for object relabeling. 1964 * @ssid: source security identifier 1965 * @tsid: target security identifier 1966 * @tclass: target security class 1967 * @out_sid: security identifier for selected member 1968 * 1969 * Compute a SID to use for relabeling an object of class @tclass 1970 * based on a SID pair (@ssid, @tsid). 1971 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1972 * if insufficient memory is available, or %0 if the SID was 1973 * computed successfully. 1974 */ 1975 int security_change_sid(struct selinux_state *state, 1976 u32 ssid, 1977 u32 tsid, 1978 u16 tclass, 1979 u32 *out_sid) 1980 { 1981 return security_compute_sid(state, 1982 ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1983 out_sid, false); 1984 } 1985 1986 static inline int convert_context_handle_invalid_context( 1987 struct selinux_state *state, 1988 struct policydb *policydb, 1989 struct context *context) 1990 { 1991 char *s; 1992 u32 len; 1993 1994 if (enforcing_enabled(state)) 1995 return -EINVAL; 1996 1997 if (!context_struct_to_string(policydb, context, &s, &len)) { 1998 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 1999 s); 2000 kfree(s); 2001 } 2002 return 0; 2003 } 2004 2005 /* 2006 * Convert the values in the security context 2007 * structure `oldc' from the values specified 2008 * in the policy `p->oldp' to the values specified 2009 * in the policy `p->newp', storing the new context 2010 * in `newc'. Verify that the context is valid 2011 * under the new policy. 2012 */ 2013 static int convert_context(struct context *oldc, struct context *newc, void *p) 2014 { 2015 struct convert_context_args *args; 2016 struct ocontext *oc; 2017 struct role_datum *role; 2018 struct type_datum *typdatum; 2019 struct user_datum *usrdatum; 2020 char *s; 2021 u32 len; 2022 int rc; 2023 2024 args = p; 2025 2026 if (oldc->str) { 2027 s = kstrdup(oldc->str, GFP_KERNEL); 2028 if (!s) 2029 return -ENOMEM; 2030 2031 rc = string_to_context_struct(args->newp, NULL, s, 2032 newc, SECSID_NULL); 2033 if (rc == -EINVAL) { 2034 /* 2035 * Retain string representation for later mapping. 2036 * 2037 * IMPORTANT: We need to copy the contents of oldc->str 2038 * back into s again because string_to_context_struct() 2039 * may have garbled it. 2040 */ 2041 memcpy(s, oldc->str, oldc->len); 2042 context_init(newc); 2043 newc->str = s; 2044 newc->len = oldc->len; 2045 return 0; 2046 } 2047 kfree(s); 2048 if (rc) { 2049 /* Other error condition, e.g. ENOMEM. */ 2050 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2051 oldc->str, -rc); 2052 return rc; 2053 } 2054 pr_info("SELinux: Context %s became valid (mapped).\n", 2055 oldc->str); 2056 return 0; 2057 } 2058 2059 context_init(newc); 2060 2061 /* Convert the user. */ 2062 rc = -EINVAL; 2063 usrdatum = symtab_search(&args->newp->p_users, 2064 sym_name(args->oldp, 2065 SYM_USERS, oldc->user - 1)); 2066 if (!usrdatum) 2067 goto bad; 2068 newc->user = usrdatum->value; 2069 2070 /* Convert the role. */ 2071 rc = -EINVAL; 2072 role = symtab_search(&args->newp->p_roles, 2073 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2074 if (!role) 2075 goto bad; 2076 newc->role = role->value; 2077 2078 /* Convert the type. */ 2079 rc = -EINVAL; 2080 typdatum = symtab_search(&args->newp->p_types, 2081 sym_name(args->oldp, 2082 SYM_TYPES, oldc->type - 1)); 2083 if (!typdatum) 2084 goto bad; 2085 newc->type = typdatum->value; 2086 2087 /* Convert the MLS fields if dealing with MLS policies */ 2088 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2089 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2090 if (rc) 2091 goto bad; 2092 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2093 /* 2094 * Switching between non-MLS and MLS policy: 2095 * ensure that the MLS fields of the context for all 2096 * existing entries in the sidtab are filled in with a 2097 * suitable default value, likely taken from one of the 2098 * initial SIDs. 2099 */ 2100 oc = args->newp->ocontexts[OCON_ISID]; 2101 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2102 oc = oc->next; 2103 rc = -EINVAL; 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, 2118 oldc); 2119 if (rc) 2120 goto bad; 2121 } 2122 2123 return 0; 2124 bad: 2125 /* Map old representation to string and save it. */ 2126 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2127 if (rc) 2128 return rc; 2129 context_destroy(newc); 2130 newc->str = s; 2131 newc->len = len; 2132 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2133 newc->str); 2134 return 0; 2135 } 2136 2137 static void security_load_policycaps(struct selinux_state *state, 2138 struct selinux_policy *policy) 2139 { 2140 struct policydb *p; 2141 unsigned int i; 2142 struct ebitmap_node *node; 2143 2144 p = &policy->policydb; 2145 2146 for (i = 0; i < ARRAY_SIZE(state->policycap); i++) 2147 WRITE_ONCE(state->policycap[i], 2148 ebitmap_get_bit(&p->policycaps, i)); 2149 2150 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2151 pr_info("SELinux: policy capability %s=%d\n", 2152 selinux_policycap_names[i], 2153 ebitmap_get_bit(&p->policycaps, i)); 2154 2155 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2156 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2157 pr_info("SELinux: unknown policy capability %u\n", 2158 i); 2159 } 2160 } 2161 2162 static int security_preserve_bools(struct selinux_policy *oldpolicy, 2163 struct selinux_policy *newpolicy); 2164 2165 static void selinux_policy_free(struct selinux_policy *policy) 2166 { 2167 if (!policy) 2168 return; 2169 2170 sidtab_destroy(policy->sidtab); 2171 kfree(policy->map.mapping); 2172 policydb_destroy(&policy->policydb); 2173 kfree(policy->sidtab); 2174 kfree(policy); 2175 } 2176 2177 static void selinux_policy_cond_free(struct selinux_policy *policy) 2178 { 2179 cond_policydb_destroy_dup(&policy->policydb); 2180 kfree(policy); 2181 } 2182 2183 void selinux_policy_cancel(struct selinux_state *state, 2184 struct selinux_load_state *load_state) 2185 { 2186 struct selinux_policy *oldpolicy; 2187 2188 oldpolicy = rcu_dereference_protected(state->policy, 2189 lockdep_is_held(&state->policy_mutex)); 2190 2191 sidtab_cancel_convert(oldpolicy->sidtab); 2192 selinux_policy_free(load_state->policy); 2193 kfree(load_state->convert_data); 2194 } 2195 2196 static void selinux_notify_policy_change(struct selinux_state *state, 2197 u32 seqno) 2198 { 2199 /* Flush external caches and notify userspace of policy load */ 2200 avc_ss_reset(state->avc, seqno); 2201 selnl_notify_policyload(seqno); 2202 selinux_status_update_policyload(state, seqno); 2203 selinux_netlbl_cache_invalidate(); 2204 selinux_xfrm_notify_policyload(); 2205 selinux_ima_measure_state(state); 2206 } 2207 2208 void selinux_policy_commit(struct selinux_state *state, 2209 struct selinux_load_state *load_state) 2210 { 2211 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2212 unsigned long flags; 2213 u32 seqno; 2214 2215 oldpolicy = rcu_dereference_protected(state->policy, 2216 lockdep_is_held(&state->policy_mutex)); 2217 2218 /* If switching between different policy types, log MLS status */ 2219 if (oldpolicy) { 2220 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2221 pr_info("SELinux: Disabling MLS support...\n"); 2222 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2223 pr_info("SELinux: Enabling MLS support...\n"); 2224 } 2225 2226 /* Set latest granting seqno for new policy. */ 2227 if (oldpolicy) 2228 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2229 else 2230 newpolicy->latest_granting = 1; 2231 seqno = newpolicy->latest_granting; 2232 2233 /* Install the new policy. */ 2234 if (oldpolicy) { 2235 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2236 rcu_assign_pointer(state->policy, newpolicy); 2237 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2238 } else { 2239 rcu_assign_pointer(state->policy, newpolicy); 2240 } 2241 2242 /* Load the policycaps from the new policy */ 2243 security_load_policycaps(state, newpolicy); 2244 2245 if (!selinux_initialized(state)) { 2246 /* 2247 * After first policy load, the security server is 2248 * marked as initialized and ready to handle requests and 2249 * any objects created prior to policy load are then labeled. 2250 */ 2251 selinux_mark_initialized(state); 2252 selinux_complete_init(); 2253 } 2254 2255 /* Free the old policy */ 2256 synchronize_rcu(); 2257 selinux_policy_free(oldpolicy); 2258 kfree(load_state->convert_data); 2259 2260 /* Notify others of the policy change */ 2261 selinux_notify_policy_change(state, seqno); 2262 } 2263 2264 /** 2265 * security_load_policy - Load a security policy configuration. 2266 * @data: binary policy data 2267 * @len: length of data in bytes 2268 * 2269 * Load a new set of security policy configuration data, 2270 * validate it and convert the SID table as necessary. 2271 * This function will flush the access vector cache after 2272 * loading the new policy. 2273 */ 2274 int security_load_policy(struct selinux_state *state, void *data, size_t len, 2275 struct selinux_load_state *load_state) 2276 { 2277 struct selinux_policy *newpolicy, *oldpolicy; 2278 struct selinux_policy_convert_data *convert_data; 2279 int rc = 0; 2280 struct policy_file file = { data, len }, *fp = &file; 2281 2282 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); 2283 if (!newpolicy) 2284 return -ENOMEM; 2285 2286 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); 2287 if (!newpolicy->sidtab) { 2288 rc = -ENOMEM; 2289 goto err_policy; 2290 } 2291 2292 rc = policydb_read(&newpolicy->policydb, fp); 2293 if (rc) 2294 goto err_sidtab; 2295 2296 newpolicy->policydb.len = len; 2297 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, 2298 &newpolicy->map); 2299 if (rc) 2300 goto err_policydb; 2301 2302 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); 2303 if (rc) { 2304 pr_err("SELinux: unable to load the initial SIDs\n"); 2305 goto err_mapping; 2306 } 2307 2308 if (!selinux_initialized(state)) { 2309 /* First policy load, so no need to preserve state from old policy */ 2310 load_state->policy = newpolicy; 2311 load_state->convert_data = NULL; 2312 return 0; 2313 } 2314 2315 oldpolicy = rcu_dereference_protected(state->policy, 2316 lockdep_is_held(&state->policy_mutex)); 2317 2318 /* Preserve active boolean values from the old policy */ 2319 rc = security_preserve_bools(oldpolicy, newpolicy); 2320 if (rc) { 2321 pr_err("SELinux: unable to preserve booleans\n"); 2322 goto err_free_isids; 2323 } 2324 2325 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2326 if (!convert_data) { 2327 rc = -ENOMEM; 2328 goto err_free_isids; 2329 } 2330 2331 /* 2332 * Convert the internal representations of contexts 2333 * in the new SID table. 2334 */ 2335 convert_data->args.state = state; 2336 convert_data->args.oldp = &oldpolicy->policydb; 2337 convert_data->args.newp = &newpolicy->policydb; 2338 2339 convert_data->sidtab_params.func = convert_context; 2340 convert_data->sidtab_params.args = &convert_data->args; 2341 convert_data->sidtab_params.target = newpolicy->sidtab; 2342 2343 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); 2344 if (rc) { 2345 pr_err("SELinux: unable to convert the internal" 2346 " representation of contexts in the new SID" 2347 " table\n"); 2348 goto err_free_convert_data; 2349 } 2350 2351 load_state->policy = newpolicy; 2352 load_state->convert_data = convert_data; 2353 return 0; 2354 2355 err_free_convert_data: 2356 kfree(convert_data); 2357 err_free_isids: 2358 sidtab_destroy(newpolicy->sidtab); 2359 err_mapping: 2360 kfree(newpolicy->map.mapping); 2361 err_policydb: 2362 policydb_destroy(&newpolicy->policydb); 2363 err_sidtab: 2364 kfree(newpolicy->sidtab); 2365 err_policy: 2366 kfree(newpolicy); 2367 2368 return rc; 2369 } 2370 2371 /** 2372 * security_port_sid - Obtain the SID for a port. 2373 * @protocol: protocol number 2374 * @port: port number 2375 * @out_sid: security identifier 2376 */ 2377 int security_port_sid(struct selinux_state *state, 2378 u8 protocol, u16 port, u32 *out_sid) 2379 { 2380 struct selinux_policy *policy; 2381 struct policydb *policydb; 2382 struct sidtab *sidtab; 2383 struct ocontext *c; 2384 int rc; 2385 2386 if (!selinux_initialized(state)) { 2387 *out_sid = SECINITSID_PORT; 2388 return 0; 2389 } 2390 2391 retry: 2392 rc = 0; 2393 rcu_read_lock(); 2394 policy = rcu_dereference(state->policy); 2395 policydb = &policy->policydb; 2396 sidtab = policy->sidtab; 2397 2398 c = policydb->ocontexts[OCON_PORT]; 2399 while (c) { 2400 if (c->u.port.protocol == protocol && 2401 c->u.port.low_port <= port && 2402 c->u.port.high_port >= port) 2403 break; 2404 c = c->next; 2405 } 2406 2407 if (c) { 2408 if (!c->sid[0]) { 2409 rc = sidtab_context_to_sid(sidtab, &c->context[0], 2410 &c->sid[0]); 2411 if (rc == -ESTALE) { 2412 rcu_read_unlock(); 2413 goto retry; 2414 } 2415 if (rc) 2416 goto out; 2417 } 2418 *out_sid = c->sid[0]; 2419 } else { 2420 *out_sid = SECINITSID_PORT; 2421 } 2422 2423 out: 2424 rcu_read_unlock(); 2425 return rc; 2426 } 2427 2428 /** 2429 * security_pkey_sid - Obtain the SID for a pkey. 2430 * @subnet_prefix: Subnet Prefix 2431 * @pkey_num: pkey number 2432 * @out_sid: security identifier 2433 */ 2434 int security_ib_pkey_sid(struct selinux_state *state, 2435 u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2436 { 2437 struct selinux_policy *policy; 2438 struct policydb *policydb; 2439 struct sidtab *sidtab; 2440 struct ocontext *c; 2441 int rc; 2442 2443 if (!selinux_initialized(state)) { 2444 *out_sid = SECINITSID_UNLABELED; 2445 return 0; 2446 } 2447 2448 retry: 2449 rc = 0; 2450 rcu_read_lock(); 2451 policy = rcu_dereference(state->policy); 2452 policydb = &policy->policydb; 2453 sidtab = policy->sidtab; 2454 2455 c = policydb->ocontexts[OCON_IBPKEY]; 2456 while (c) { 2457 if (c->u.ibpkey.low_pkey <= pkey_num && 2458 c->u.ibpkey.high_pkey >= pkey_num && 2459 c->u.ibpkey.subnet_prefix == subnet_prefix) 2460 break; 2461 2462 c = c->next; 2463 } 2464 2465 if (c) { 2466 if (!c->sid[0]) { 2467 rc = sidtab_context_to_sid(sidtab, 2468 &c->context[0], 2469 &c->sid[0]); 2470 if (rc == -ESTALE) { 2471 rcu_read_unlock(); 2472 goto retry; 2473 } 2474 if (rc) 2475 goto out; 2476 } 2477 *out_sid = c->sid[0]; 2478 } else 2479 *out_sid = SECINITSID_UNLABELED; 2480 2481 out: 2482 rcu_read_unlock(); 2483 return rc; 2484 } 2485 2486 /** 2487 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2488 * @dev_name: device name 2489 * @port: port number 2490 * @out_sid: security identifier 2491 */ 2492 int security_ib_endport_sid(struct selinux_state *state, 2493 const char *dev_name, u8 port_num, u32 *out_sid) 2494 { 2495 struct selinux_policy *policy; 2496 struct policydb *policydb; 2497 struct sidtab *sidtab; 2498 struct ocontext *c; 2499 int rc; 2500 2501 if (!selinux_initialized(state)) { 2502 *out_sid = SECINITSID_UNLABELED; 2503 return 0; 2504 } 2505 2506 retry: 2507 rc = 0; 2508 rcu_read_lock(); 2509 policy = rcu_dereference(state->policy); 2510 policydb = &policy->policydb; 2511 sidtab = policy->sidtab; 2512 2513 c = policydb->ocontexts[OCON_IBENDPORT]; 2514 while (c) { 2515 if (c->u.ibendport.port == port_num && 2516 !strncmp(c->u.ibendport.dev_name, 2517 dev_name, 2518 IB_DEVICE_NAME_MAX)) 2519 break; 2520 2521 c = c->next; 2522 } 2523 2524 if (c) { 2525 if (!c->sid[0]) { 2526 rc = sidtab_context_to_sid(sidtab, &c->context[0], 2527 &c->sid[0]); 2528 if (rc == -ESTALE) { 2529 rcu_read_unlock(); 2530 goto retry; 2531 } 2532 if (rc) 2533 goto out; 2534 } 2535 *out_sid = c->sid[0]; 2536 } else 2537 *out_sid = SECINITSID_UNLABELED; 2538 2539 out: 2540 rcu_read_unlock(); 2541 return rc; 2542 } 2543 2544 /** 2545 * security_netif_sid - Obtain the SID for a network interface. 2546 * @name: interface name 2547 * @if_sid: interface SID 2548 */ 2549 int security_netif_sid(struct selinux_state *state, 2550 char *name, u32 *if_sid) 2551 { 2552 struct selinux_policy *policy; 2553 struct policydb *policydb; 2554 struct sidtab *sidtab; 2555 int rc; 2556 struct ocontext *c; 2557 2558 if (!selinux_initialized(state)) { 2559 *if_sid = SECINITSID_NETIF; 2560 return 0; 2561 } 2562 2563 retry: 2564 rc = 0; 2565 rcu_read_lock(); 2566 policy = rcu_dereference(state->policy); 2567 policydb = &policy->policydb; 2568 sidtab = policy->sidtab; 2569 2570 c = policydb->ocontexts[OCON_NETIF]; 2571 while (c) { 2572 if (strcmp(name, c->u.name) == 0) 2573 break; 2574 c = c->next; 2575 } 2576 2577 if (c) { 2578 if (!c->sid[0] || !c->sid[1]) { 2579 rc = sidtab_context_to_sid(sidtab, &c->context[0], 2580 &c->sid[0]); 2581 if (rc == -ESTALE) { 2582 rcu_read_unlock(); 2583 goto retry; 2584 } 2585 if (rc) 2586 goto out; 2587 rc = sidtab_context_to_sid(sidtab, &c->context[1], 2588 &c->sid[1]); 2589 if (rc == -ESTALE) { 2590 rcu_read_unlock(); 2591 goto retry; 2592 } 2593 if (rc) 2594 goto out; 2595 } 2596 *if_sid = c->sid[0]; 2597 } else 2598 *if_sid = SECINITSID_NETIF; 2599 2600 out: 2601 rcu_read_unlock(); 2602 return rc; 2603 } 2604 2605 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2606 { 2607 int i, fail = 0; 2608 2609 for (i = 0; i < 4; i++) 2610 if (addr[i] != (input[i] & mask[i])) { 2611 fail = 1; 2612 break; 2613 } 2614 2615 return !fail; 2616 } 2617 2618 /** 2619 * security_node_sid - Obtain the SID for a node (host). 2620 * @domain: communication domain aka address family 2621 * @addrp: address 2622 * @addrlen: address length in bytes 2623 * @out_sid: security identifier 2624 */ 2625 int security_node_sid(struct selinux_state *state, 2626 u16 domain, 2627 void *addrp, 2628 u32 addrlen, 2629 u32 *out_sid) 2630 { 2631 struct selinux_policy *policy; 2632 struct policydb *policydb; 2633 struct sidtab *sidtab; 2634 int rc; 2635 struct ocontext *c; 2636 2637 if (!selinux_initialized(state)) { 2638 *out_sid = SECINITSID_NODE; 2639 return 0; 2640 } 2641 2642 retry: 2643 rcu_read_lock(); 2644 policy = rcu_dereference(state->policy); 2645 policydb = &policy->policydb; 2646 sidtab = policy->sidtab; 2647 2648 switch (domain) { 2649 case AF_INET: { 2650 u32 addr; 2651 2652 rc = -EINVAL; 2653 if (addrlen != sizeof(u32)) 2654 goto out; 2655 2656 addr = *((u32 *)addrp); 2657 2658 c = policydb->ocontexts[OCON_NODE]; 2659 while (c) { 2660 if (c->u.node.addr == (addr & c->u.node.mask)) 2661 break; 2662 c = c->next; 2663 } 2664 break; 2665 } 2666 2667 case AF_INET6: 2668 rc = -EINVAL; 2669 if (addrlen != sizeof(u64) * 2) 2670 goto out; 2671 c = policydb->ocontexts[OCON_NODE6]; 2672 while (c) { 2673 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2674 c->u.node6.mask)) 2675 break; 2676 c = c->next; 2677 } 2678 break; 2679 2680 default: 2681 rc = 0; 2682 *out_sid = SECINITSID_NODE; 2683 goto out; 2684 } 2685 2686 if (c) { 2687 if (!c->sid[0]) { 2688 rc = sidtab_context_to_sid(sidtab, 2689 &c->context[0], 2690 &c->sid[0]); 2691 if (rc == -ESTALE) { 2692 rcu_read_unlock(); 2693 goto retry; 2694 } 2695 if (rc) 2696 goto out; 2697 } 2698 *out_sid = c->sid[0]; 2699 } else { 2700 *out_sid = SECINITSID_NODE; 2701 } 2702 2703 rc = 0; 2704 out: 2705 rcu_read_unlock(); 2706 return rc; 2707 } 2708 2709 #define SIDS_NEL 25 2710 2711 /** 2712 * security_get_user_sids - Obtain reachable SIDs for a user. 2713 * @fromsid: starting SID 2714 * @username: username 2715 * @sids: array of reachable SIDs for user 2716 * @nel: number of elements in @sids 2717 * 2718 * Generate the set of SIDs for legal security contexts 2719 * for a given user that can be reached by @fromsid. 2720 * Set *@sids to point to a dynamically allocated 2721 * array containing the set of SIDs. Set *@nel to the 2722 * number of elements in the array. 2723 */ 2724 2725 int security_get_user_sids(struct selinux_state *state, 2726 u32 fromsid, 2727 char *username, 2728 u32 **sids, 2729 u32 *nel) 2730 { 2731 struct selinux_policy *policy; 2732 struct policydb *policydb; 2733 struct sidtab *sidtab; 2734 struct context *fromcon, usercon; 2735 u32 *mysids = NULL, *mysids2, sid; 2736 u32 i, j, mynel, maxnel = SIDS_NEL; 2737 struct user_datum *user; 2738 struct role_datum *role; 2739 struct ebitmap_node *rnode, *tnode; 2740 int rc; 2741 2742 *sids = NULL; 2743 *nel = 0; 2744 2745 if (!selinux_initialized(state)) 2746 return 0; 2747 2748 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2749 if (!mysids) 2750 return -ENOMEM; 2751 2752 retry: 2753 mynel = 0; 2754 rcu_read_lock(); 2755 policy = rcu_dereference(state->policy); 2756 policydb = &policy->policydb; 2757 sidtab = policy->sidtab; 2758 2759 context_init(&usercon); 2760 2761 rc = -EINVAL; 2762 fromcon = sidtab_search(sidtab, fromsid); 2763 if (!fromcon) 2764 goto out_unlock; 2765 2766 rc = -EINVAL; 2767 user = symtab_search(&policydb->p_users, username); 2768 if (!user) 2769 goto out_unlock; 2770 2771 usercon.user = user->value; 2772 2773 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2774 role = policydb->role_val_to_struct[i]; 2775 usercon.role = i + 1; 2776 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2777 usercon.type = j + 1; 2778 2779 if (mls_setup_user_range(policydb, fromcon, user, 2780 &usercon)) 2781 continue; 2782 2783 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2784 if (rc == -ESTALE) { 2785 rcu_read_unlock(); 2786 goto retry; 2787 } 2788 if (rc) 2789 goto out_unlock; 2790 if (mynel < maxnel) { 2791 mysids[mynel++] = sid; 2792 } else { 2793 rc = -ENOMEM; 2794 maxnel += SIDS_NEL; 2795 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2796 if (!mysids2) 2797 goto out_unlock; 2798 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2799 kfree(mysids); 2800 mysids = mysids2; 2801 mysids[mynel++] = sid; 2802 } 2803 } 2804 } 2805 rc = 0; 2806 out_unlock: 2807 rcu_read_unlock(); 2808 if (rc || !mynel) { 2809 kfree(mysids); 2810 return rc; 2811 } 2812 2813 rc = -ENOMEM; 2814 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2815 if (!mysids2) { 2816 kfree(mysids); 2817 return rc; 2818 } 2819 for (i = 0, j = 0; i < mynel; i++) { 2820 struct av_decision dummy_avd; 2821 rc = avc_has_perm_noaudit(state, 2822 fromsid, mysids[i], 2823 SECCLASS_PROCESS, /* kernel value */ 2824 PROCESS__TRANSITION, AVC_STRICT, 2825 &dummy_avd); 2826 if (!rc) 2827 mysids2[j++] = mysids[i]; 2828 cond_resched(); 2829 } 2830 kfree(mysids); 2831 *sids = mysids2; 2832 *nel = j; 2833 return 0; 2834 } 2835 2836 /** 2837 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2838 * @fstype: filesystem type 2839 * @path: path from root of mount 2840 * @sclass: file security class 2841 * @sid: SID for path 2842 * 2843 * Obtain a SID to use for a file in a filesystem that 2844 * cannot support xattr or use a fixed labeling behavior like 2845 * transition SIDs or task SIDs. 2846 * 2847 * WARNING: This function may return -ESTALE, indicating that the caller 2848 * must retry the operation after re-acquiring the policy pointer! 2849 */ 2850 static inline int __security_genfs_sid(struct selinux_policy *policy, 2851 const char *fstype, 2852 char *path, 2853 u16 orig_sclass, 2854 u32 *sid) 2855 { 2856 struct policydb *policydb = &policy->policydb; 2857 struct sidtab *sidtab = policy->sidtab; 2858 int len; 2859 u16 sclass; 2860 struct genfs *genfs; 2861 struct ocontext *c; 2862 int rc, cmp = 0; 2863 2864 while (path[0] == '/' && path[1] == '/') 2865 path++; 2866 2867 sclass = unmap_class(&policy->map, orig_sclass); 2868 *sid = SECINITSID_UNLABELED; 2869 2870 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2871 cmp = strcmp(fstype, genfs->fstype); 2872 if (cmp <= 0) 2873 break; 2874 } 2875 2876 rc = -ENOENT; 2877 if (!genfs || cmp) 2878 goto out; 2879 2880 for (c = genfs->head; c; c = c->next) { 2881 len = strlen(c->u.name); 2882 if ((!c->v.sclass || sclass == c->v.sclass) && 2883 (strncmp(c->u.name, path, len) == 0)) 2884 break; 2885 } 2886 2887 rc = -ENOENT; 2888 if (!c) 2889 goto out; 2890 2891 if (!c->sid[0]) { 2892 rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]); 2893 if (rc) 2894 goto out; 2895 } 2896 2897 *sid = c->sid[0]; 2898 rc = 0; 2899 out: 2900 return rc; 2901 } 2902 2903 /** 2904 * security_genfs_sid - Obtain a SID for a file in a filesystem 2905 * @fstype: filesystem type 2906 * @path: path from root of mount 2907 * @sclass: file security class 2908 * @sid: SID for path 2909 * 2910 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2911 * it afterward. 2912 */ 2913 int security_genfs_sid(struct selinux_state *state, 2914 const char *fstype, 2915 char *path, 2916 u16 orig_sclass, 2917 u32 *sid) 2918 { 2919 struct selinux_policy *policy; 2920 int retval; 2921 2922 if (!selinux_initialized(state)) { 2923 *sid = SECINITSID_UNLABELED; 2924 return 0; 2925 } 2926 2927 do { 2928 rcu_read_lock(); 2929 policy = rcu_dereference(state->policy); 2930 retval = __security_genfs_sid(policy, fstype, path, 2931 orig_sclass, sid); 2932 rcu_read_unlock(); 2933 } while (retval == -ESTALE); 2934 return retval; 2935 } 2936 2937 int selinux_policy_genfs_sid(struct selinux_policy *policy, 2938 const char *fstype, 2939 char *path, 2940 u16 orig_sclass, 2941 u32 *sid) 2942 { 2943 /* no lock required, policy is not yet accessible by other threads */ 2944 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2945 } 2946 2947 /** 2948 * security_fs_use - Determine how to handle labeling for a filesystem. 2949 * @sb: superblock in question 2950 */ 2951 int security_fs_use(struct selinux_state *state, struct super_block *sb) 2952 { 2953 struct selinux_policy *policy; 2954 struct policydb *policydb; 2955 struct sidtab *sidtab; 2956 int rc; 2957 struct ocontext *c; 2958 struct superblock_security_struct *sbsec = sb->s_security; 2959 const char *fstype = sb->s_type->name; 2960 2961 if (!selinux_initialized(state)) { 2962 sbsec->behavior = SECURITY_FS_USE_NONE; 2963 sbsec->sid = SECINITSID_UNLABELED; 2964 return 0; 2965 } 2966 2967 retry: 2968 rc = 0; 2969 rcu_read_lock(); 2970 policy = rcu_dereference(state->policy); 2971 policydb = &policy->policydb; 2972 sidtab = policy->sidtab; 2973 2974 c = policydb->ocontexts[OCON_FSUSE]; 2975 while (c) { 2976 if (strcmp(fstype, c->u.name) == 0) 2977 break; 2978 c = c->next; 2979 } 2980 2981 if (c) { 2982 sbsec->behavior = c->v.behavior; 2983 if (!c->sid[0]) { 2984 rc = sidtab_context_to_sid(sidtab, &c->context[0], 2985 &c->sid[0]); 2986 if (rc == -ESTALE) { 2987 rcu_read_unlock(); 2988 goto retry; 2989 } 2990 if (rc) 2991 goto out; 2992 } 2993 sbsec->sid = c->sid[0]; 2994 } else { 2995 rc = __security_genfs_sid(policy, fstype, "/", 2996 SECCLASS_DIR, &sbsec->sid); 2997 if (rc == -ESTALE) { 2998 rcu_read_unlock(); 2999 goto retry; 3000 } 3001 if (rc) { 3002 sbsec->behavior = SECURITY_FS_USE_NONE; 3003 rc = 0; 3004 } else { 3005 sbsec->behavior = SECURITY_FS_USE_GENFS; 3006 } 3007 } 3008 3009 out: 3010 rcu_read_unlock(); 3011 return rc; 3012 } 3013 3014 int security_get_bools(struct selinux_policy *policy, 3015 u32 *len, char ***names, int **values) 3016 { 3017 struct policydb *policydb; 3018 u32 i; 3019 int rc; 3020 3021 policydb = &policy->policydb; 3022 3023 *names = NULL; 3024 *values = NULL; 3025 3026 rc = 0; 3027 *len = policydb->p_bools.nprim; 3028 if (!*len) 3029 goto out; 3030 3031 rc = -ENOMEM; 3032 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 3033 if (!*names) 3034 goto err; 3035 3036 rc = -ENOMEM; 3037 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 3038 if (!*values) 3039 goto err; 3040 3041 for (i = 0; i < *len; i++) { 3042 (*values)[i] = policydb->bool_val_to_struct[i]->state; 3043 3044 rc = -ENOMEM; 3045 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 3046 GFP_ATOMIC); 3047 if (!(*names)[i]) 3048 goto err; 3049 } 3050 rc = 0; 3051 out: 3052 return rc; 3053 err: 3054 if (*names) { 3055 for (i = 0; i < *len; i++) 3056 kfree((*names)[i]); 3057 kfree(*names); 3058 } 3059 kfree(*values); 3060 *len = 0; 3061 *names = NULL; 3062 *values = NULL; 3063 goto out; 3064 } 3065 3066 3067 int security_set_bools(struct selinux_state *state, u32 len, int *values) 3068 { 3069 struct selinux_policy *newpolicy, *oldpolicy; 3070 int rc; 3071 u32 i, seqno = 0; 3072 3073 if (!selinux_initialized(state)) 3074 return -EINVAL; 3075 3076 oldpolicy = rcu_dereference_protected(state->policy, 3077 lockdep_is_held(&state->policy_mutex)); 3078 3079 /* Consistency check on number of booleans, should never fail */ 3080 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) 3081 return -EINVAL; 3082 3083 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); 3084 if (!newpolicy) 3085 return -ENOMEM; 3086 3087 /* 3088 * Deep copy only the parts of the policydb that might be 3089 * modified as a result of changing booleans. 3090 */ 3091 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); 3092 if (rc) { 3093 kfree(newpolicy); 3094 return -ENOMEM; 3095 } 3096 3097 /* Update the boolean states in the copy */ 3098 for (i = 0; i < len; i++) { 3099 int new_state = !!values[i]; 3100 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; 3101 3102 if (new_state != old_state) { 3103 audit_log(audit_context(), GFP_ATOMIC, 3104 AUDIT_MAC_CONFIG_CHANGE, 3105 "bool=%s val=%d old_val=%d auid=%u ses=%u", 3106 sym_name(&newpolicy->policydb, SYM_BOOLS, i), 3107 new_state, 3108 old_state, 3109 from_kuid(&init_user_ns, audit_get_loginuid(current)), 3110 audit_get_sessionid(current)); 3111 newpolicy->policydb.bool_val_to_struct[i]->state = new_state; 3112 } 3113 } 3114 3115 /* Re-evaluate the conditional rules in the copy */ 3116 evaluate_cond_nodes(&newpolicy->policydb); 3117 3118 /* Set latest granting seqno for new policy */ 3119 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 3120 seqno = newpolicy->latest_granting; 3121 3122 /* Install the new policy */ 3123 rcu_assign_pointer(state->policy, newpolicy); 3124 3125 /* 3126 * Free the conditional portions of the old policydb 3127 * that were copied for the new policy, and the oldpolicy 3128 * structure itself but not what it references. 3129 */ 3130 synchronize_rcu(); 3131 selinux_policy_cond_free(oldpolicy); 3132 3133 /* Notify others of the policy change */ 3134 selinux_notify_policy_change(state, seqno); 3135 return 0; 3136 } 3137 3138 int security_get_bool_value(struct selinux_state *state, 3139 u32 index) 3140 { 3141 struct selinux_policy *policy; 3142 struct policydb *policydb; 3143 int rc; 3144 u32 len; 3145 3146 if (!selinux_initialized(state)) 3147 return 0; 3148 3149 rcu_read_lock(); 3150 policy = rcu_dereference(state->policy); 3151 policydb = &policy->policydb; 3152 3153 rc = -EFAULT; 3154 len = policydb->p_bools.nprim; 3155 if (index >= len) 3156 goto out; 3157 3158 rc = policydb->bool_val_to_struct[index]->state; 3159 out: 3160 rcu_read_unlock(); 3161 return rc; 3162 } 3163 3164 static int security_preserve_bools(struct selinux_policy *oldpolicy, 3165 struct selinux_policy *newpolicy) 3166 { 3167 int rc, *bvalues = NULL; 3168 char **bnames = NULL; 3169 struct cond_bool_datum *booldatum; 3170 u32 i, nbools = 0; 3171 3172 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); 3173 if (rc) 3174 goto out; 3175 for (i = 0; i < nbools; i++) { 3176 booldatum = symtab_search(&newpolicy->policydb.p_bools, 3177 bnames[i]); 3178 if (booldatum) 3179 booldatum->state = bvalues[i]; 3180 } 3181 evaluate_cond_nodes(&newpolicy->policydb); 3182 3183 out: 3184 if (bnames) { 3185 for (i = 0; i < nbools; i++) 3186 kfree(bnames[i]); 3187 } 3188 kfree(bnames); 3189 kfree(bvalues); 3190 return rc; 3191 } 3192 3193 /* 3194 * security_sid_mls_copy() - computes a new sid based on the given 3195 * sid and the mls portion of mls_sid. 3196 */ 3197 int security_sid_mls_copy(struct selinux_state *state, 3198 u32 sid, u32 mls_sid, u32 *new_sid) 3199 { 3200 struct selinux_policy *policy; 3201 struct policydb *policydb; 3202 struct sidtab *sidtab; 3203 struct context *context1; 3204 struct context *context2; 3205 struct context newcon; 3206 char *s; 3207 u32 len; 3208 int rc; 3209 3210 if (!selinux_initialized(state)) { 3211 *new_sid = sid; 3212 return 0; 3213 } 3214 3215 retry: 3216 rc = 0; 3217 context_init(&newcon); 3218 3219 rcu_read_lock(); 3220 policy = rcu_dereference(state->policy); 3221 policydb = &policy->policydb; 3222 sidtab = policy->sidtab; 3223 3224 if (!policydb->mls_enabled) { 3225 *new_sid = sid; 3226 goto out_unlock; 3227 } 3228 3229 rc = -EINVAL; 3230 context1 = sidtab_search(sidtab, sid); 3231 if (!context1) { 3232 pr_err("SELinux: %s: unrecognized SID %d\n", 3233 __func__, sid); 3234 goto out_unlock; 3235 } 3236 3237 rc = -EINVAL; 3238 context2 = sidtab_search(sidtab, mls_sid); 3239 if (!context2) { 3240 pr_err("SELinux: %s: unrecognized SID %d\n", 3241 __func__, mls_sid); 3242 goto out_unlock; 3243 } 3244 3245 newcon.user = context1->user; 3246 newcon.role = context1->role; 3247 newcon.type = context1->type; 3248 rc = mls_context_cpy(&newcon, context2); 3249 if (rc) 3250 goto out_unlock; 3251 3252 /* Check the validity of the new context. */ 3253 if (!policydb_context_isvalid(policydb, &newcon)) { 3254 rc = convert_context_handle_invalid_context(state, policydb, 3255 &newcon); 3256 if (rc) { 3257 if (!context_struct_to_string(policydb, &newcon, &s, 3258 &len)) { 3259 struct audit_buffer *ab; 3260 3261 ab = audit_log_start(audit_context(), 3262 GFP_ATOMIC, 3263 AUDIT_SELINUX_ERR); 3264 audit_log_format(ab, 3265 "op=security_sid_mls_copy invalid_context="); 3266 /* don't record NUL with untrusted strings */ 3267 audit_log_n_untrustedstring(ab, s, len - 1); 3268 audit_log_end(ab); 3269 kfree(s); 3270 } 3271 goto out_unlock; 3272 } 3273 } 3274 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3275 if (rc == -ESTALE) { 3276 rcu_read_unlock(); 3277 context_destroy(&newcon); 3278 goto retry; 3279 } 3280 out_unlock: 3281 rcu_read_unlock(); 3282 context_destroy(&newcon); 3283 return rc; 3284 } 3285 3286 /** 3287 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3288 * @nlbl_sid: NetLabel SID 3289 * @nlbl_type: NetLabel labeling protocol type 3290 * @xfrm_sid: XFRM SID 3291 * 3292 * Description: 3293 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3294 * resolved into a single SID it is returned via @peer_sid and the function 3295 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3296 * returns a negative value. A table summarizing the behavior is below: 3297 * 3298 * | function return | @sid 3299 * ------------------------------+-----------------+----------------- 3300 * no peer labels | 0 | SECSID_NULL 3301 * single peer label | 0 | <peer_label> 3302 * multiple, consistent labels | 0 | <peer_label> 3303 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3304 * 3305 */ 3306 int security_net_peersid_resolve(struct selinux_state *state, 3307 u32 nlbl_sid, u32 nlbl_type, 3308 u32 xfrm_sid, 3309 u32 *peer_sid) 3310 { 3311 struct selinux_policy *policy; 3312 struct policydb *policydb; 3313 struct sidtab *sidtab; 3314 int rc; 3315 struct context *nlbl_ctx; 3316 struct context *xfrm_ctx; 3317 3318 *peer_sid = SECSID_NULL; 3319 3320 /* handle the common (which also happens to be the set of easy) cases 3321 * right away, these two if statements catch everything involving a 3322 * single or absent peer SID/label */ 3323 if (xfrm_sid == SECSID_NULL) { 3324 *peer_sid = nlbl_sid; 3325 return 0; 3326 } 3327 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3328 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3329 * is present */ 3330 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3331 *peer_sid = xfrm_sid; 3332 return 0; 3333 } 3334 3335 if (!selinux_initialized(state)) 3336 return 0; 3337 3338 rcu_read_lock(); 3339 policy = rcu_dereference(state->policy); 3340 policydb = &policy->policydb; 3341 sidtab = policy->sidtab; 3342 3343 /* 3344 * We don't need to check initialized here since the only way both 3345 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3346 * security server was initialized and state->initialized was true. 3347 */ 3348 if (!policydb->mls_enabled) { 3349 rc = 0; 3350 goto out; 3351 } 3352 3353 rc = -EINVAL; 3354 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3355 if (!nlbl_ctx) { 3356 pr_err("SELinux: %s: unrecognized SID %d\n", 3357 __func__, nlbl_sid); 3358 goto out; 3359 } 3360 rc = -EINVAL; 3361 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3362 if (!xfrm_ctx) { 3363 pr_err("SELinux: %s: unrecognized SID %d\n", 3364 __func__, xfrm_sid); 3365 goto out; 3366 } 3367 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3368 if (rc) 3369 goto out; 3370 3371 /* at present NetLabel SIDs/labels really only carry MLS 3372 * information so if the MLS portion of the NetLabel SID 3373 * matches the MLS portion of the labeled XFRM SID/label 3374 * then pass along the XFRM SID as it is the most 3375 * expressive */ 3376 *peer_sid = xfrm_sid; 3377 out: 3378 rcu_read_unlock(); 3379 return rc; 3380 } 3381 3382 static int get_classes_callback(void *k, void *d, void *args) 3383 { 3384 struct class_datum *datum = d; 3385 char *name = k, **classes = args; 3386 int value = datum->value - 1; 3387 3388 classes[value] = kstrdup(name, GFP_ATOMIC); 3389 if (!classes[value]) 3390 return -ENOMEM; 3391 3392 return 0; 3393 } 3394 3395 int security_get_classes(struct selinux_policy *policy, 3396 char ***classes, int *nclasses) 3397 { 3398 struct policydb *policydb; 3399 int rc; 3400 3401 policydb = &policy->policydb; 3402 3403 rc = -ENOMEM; 3404 *nclasses = policydb->p_classes.nprim; 3405 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3406 if (!*classes) 3407 goto out; 3408 3409 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3410 *classes); 3411 if (rc) { 3412 int i; 3413 for (i = 0; i < *nclasses; i++) 3414 kfree((*classes)[i]); 3415 kfree(*classes); 3416 } 3417 3418 out: 3419 return rc; 3420 } 3421 3422 static int get_permissions_callback(void *k, void *d, void *args) 3423 { 3424 struct perm_datum *datum = d; 3425 char *name = k, **perms = args; 3426 int value = datum->value - 1; 3427 3428 perms[value] = kstrdup(name, GFP_ATOMIC); 3429 if (!perms[value]) 3430 return -ENOMEM; 3431 3432 return 0; 3433 } 3434 3435 int security_get_permissions(struct selinux_policy *policy, 3436 char *class, char ***perms, int *nperms) 3437 { 3438 struct policydb *policydb; 3439 int rc, i; 3440 struct class_datum *match; 3441 3442 policydb = &policy->policydb; 3443 3444 rc = -EINVAL; 3445 match = symtab_search(&policydb->p_classes, class); 3446 if (!match) { 3447 pr_err("SELinux: %s: unrecognized class %s\n", 3448 __func__, class); 3449 goto out; 3450 } 3451 3452 rc = -ENOMEM; 3453 *nperms = match->permissions.nprim; 3454 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3455 if (!*perms) 3456 goto out; 3457 3458 if (match->comdatum) { 3459 rc = hashtab_map(&match->comdatum->permissions.table, 3460 get_permissions_callback, *perms); 3461 if (rc) 3462 goto err; 3463 } 3464 3465 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3466 *perms); 3467 if (rc) 3468 goto err; 3469 3470 out: 3471 return rc; 3472 3473 err: 3474 for (i = 0; i < *nperms; i++) 3475 kfree((*perms)[i]); 3476 kfree(*perms); 3477 return rc; 3478 } 3479 3480 int security_get_reject_unknown(struct selinux_state *state) 3481 { 3482 struct selinux_policy *policy; 3483 int value; 3484 3485 if (!selinux_initialized(state)) 3486 return 0; 3487 3488 rcu_read_lock(); 3489 policy = rcu_dereference(state->policy); 3490 value = policy->policydb.reject_unknown; 3491 rcu_read_unlock(); 3492 return value; 3493 } 3494 3495 int security_get_allow_unknown(struct selinux_state *state) 3496 { 3497 struct selinux_policy *policy; 3498 int value; 3499 3500 if (!selinux_initialized(state)) 3501 return 0; 3502 3503 rcu_read_lock(); 3504 policy = rcu_dereference(state->policy); 3505 value = policy->policydb.allow_unknown; 3506 rcu_read_unlock(); 3507 return value; 3508 } 3509 3510 /** 3511 * security_policycap_supported - Check for a specific policy capability 3512 * @req_cap: capability 3513 * 3514 * Description: 3515 * This function queries the currently loaded policy to see if it supports the 3516 * capability specified by @req_cap. Returns true (1) if the capability is 3517 * supported, false (0) if it isn't supported. 3518 * 3519 */ 3520 int security_policycap_supported(struct selinux_state *state, 3521 unsigned int req_cap) 3522 { 3523 struct selinux_policy *policy; 3524 int rc; 3525 3526 if (!selinux_initialized(state)) 3527 return 0; 3528 3529 rcu_read_lock(); 3530 policy = rcu_dereference(state->policy); 3531 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3532 rcu_read_unlock(); 3533 3534 return rc; 3535 } 3536 3537 struct selinux_audit_rule { 3538 u32 au_seqno; 3539 struct context au_ctxt; 3540 }; 3541 3542 void selinux_audit_rule_free(void *vrule) 3543 { 3544 struct selinux_audit_rule *rule = vrule; 3545 3546 if (rule) { 3547 context_destroy(&rule->au_ctxt); 3548 kfree(rule); 3549 } 3550 } 3551 3552 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3553 { 3554 struct selinux_state *state = &selinux_state; 3555 struct selinux_policy *policy; 3556 struct policydb *policydb; 3557 struct selinux_audit_rule *tmprule; 3558 struct role_datum *roledatum; 3559 struct type_datum *typedatum; 3560 struct user_datum *userdatum; 3561 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3562 int rc = 0; 3563 3564 *rule = NULL; 3565 3566 if (!selinux_initialized(state)) 3567 return -EOPNOTSUPP; 3568 3569 switch (field) { 3570 case AUDIT_SUBJ_USER: 3571 case AUDIT_SUBJ_ROLE: 3572 case AUDIT_SUBJ_TYPE: 3573 case AUDIT_OBJ_USER: 3574 case AUDIT_OBJ_ROLE: 3575 case AUDIT_OBJ_TYPE: 3576 /* only 'equals' and 'not equals' fit user, role, and type */ 3577 if (op != Audit_equal && op != Audit_not_equal) 3578 return -EINVAL; 3579 break; 3580 case AUDIT_SUBJ_SEN: 3581 case AUDIT_SUBJ_CLR: 3582 case AUDIT_OBJ_LEV_LOW: 3583 case AUDIT_OBJ_LEV_HIGH: 3584 /* we do not allow a range, indicated by the presence of '-' */ 3585 if (strchr(rulestr, '-')) 3586 return -EINVAL; 3587 break; 3588 default: 3589 /* only the above fields are valid */ 3590 return -EINVAL; 3591 } 3592 3593 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3594 if (!tmprule) 3595 return -ENOMEM; 3596 3597 context_init(&tmprule->au_ctxt); 3598 3599 rcu_read_lock(); 3600 policy = rcu_dereference(state->policy); 3601 policydb = &policy->policydb; 3602 3603 tmprule->au_seqno = policy->latest_granting; 3604 3605 switch (field) { 3606 case AUDIT_SUBJ_USER: 3607 case AUDIT_OBJ_USER: 3608 rc = -EINVAL; 3609 userdatum = symtab_search(&policydb->p_users, rulestr); 3610 if (!userdatum) 3611 goto out; 3612 tmprule->au_ctxt.user = userdatum->value; 3613 break; 3614 case AUDIT_SUBJ_ROLE: 3615 case AUDIT_OBJ_ROLE: 3616 rc = -EINVAL; 3617 roledatum = symtab_search(&policydb->p_roles, rulestr); 3618 if (!roledatum) 3619 goto out; 3620 tmprule->au_ctxt.role = roledatum->value; 3621 break; 3622 case AUDIT_SUBJ_TYPE: 3623 case AUDIT_OBJ_TYPE: 3624 rc = -EINVAL; 3625 typedatum = symtab_search(&policydb->p_types, rulestr); 3626 if (!typedatum) 3627 goto out; 3628 tmprule->au_ctxt.type = typedatum->value; 3629 break; 3630 case AUDIT_SUBJ_SEN: 3631 case AUDIT_SUBJ_CLR: 3632 case AUDIT_OBJ_LEV_LOW: 3633 case AUDIT_OBJ_LEV_HIGH: 3634 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3635 GFP_ATOMIC); 3636 if (rc) 3637 goto out; 3638 break; 3639 } 3640 rc = 0; 3641 out: 3642 rcu_read_unlock(); 3643 3644 if (rc) { 3645 selinux_audit_rule_free(tmprule); 3646 tmprule = NULL; 3647 } 3648 3649 *rule = tmprule; 3650 3651 return rc; 3652 } 3653 3654 /* Check to see if the rule contains any selinux fields */ 3655 int selinux_audit_rule_known(struct audit_krule *rule) 3656 { 3657 int i; 3658 3659 for (i = 0; i < rule->field_count; i++) { 3660 struct audit_field *f = &rule->fields[i]; 3661 switch (f->type) { 3662 case AUDIT_SUBJ_USER: 3663 case AUDIT_SUBJ_ROLE: 3664 case AUDIT_SUBJ_TYPE: 3665 case AUDIT_SUBJ_SEN: 3666 case AUDIT_SUBJ_CLR: 3667 case AUDIT_OBJ_USER: 3668 case AUDIT_OBJ_ROLE: 3669 case AUDIT_OBJ_TYPE: 3670 case AUDIT_OBJ_LEV_LOW: 3671 case AUDIT_OBJ_LEV_HIGH: 3672 return 1; 3673 } 3674 } 3675 3676 return 0; 3677 } 3678 3679 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) 3680 { 3681 struct selinux_state *state = &selinux_state; 3682 struct selinux_policy *policy; 3683 struct context *ctxt; 3684 struct mls_level *level; 3685 struct selinux_audit_rule *rule = vrule; 3686 int match = 0; 3687 3688 if (unlikely(!rule)) { 3689 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3690 return -ENOENT; 3691 } 3692 3693 if (!selinux_initialized(state)) 3694 return 0; 3695 3696 rcu_read_lock(); 3697 3698 policy = rcu_dereference(state->policy); 3699 3700 if (rule->au_seqno < policy->latest_granting) { 3701 match = -ESTALE; 3702 goto out; 3703 } 3704 3705 ctxt = sidtab_search(policy->sidtab, sid); 3706 if (unlikely(!ctxt)) { 3707 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3708 sid); 3709 match = -ENOENT; 3710 goto out; 3711 } 3712 3713 /* a field/op pair that is not caught here will simply fall through 3714 without a match */ 3715 switch (field) { 3716 case AUDIT_SUBJ_USER: 3717 case AUDIT_OBJ_USER: 3718 switch (op) { 3719 case Audit_equal: 3720 match = (ctxt->user == rule->au_ctxt.user); 3721 break; 3722 case Audit_not_equal: 3723 match = (ctxt->user != rule->au_ctxt.user); 3724 break; 3725 } 3726 break; 3727 case AUDIT_SUBJ_ROLE: 3728 case AUDIT_OBJ_ROLE: 3729 switch (op) { 3730 case Audit_equal: 3731 match = (ctxt->role == rule->au_ctxt.role); 3732 break; 3733 case Audit_not_equal: 3734 match = (ctxt->role != rule->au_ctxt.role); 3735 break; 3736 } 3737 break; 3738 case AUDIT_SUBJ_TYPE: 3739 case AUDIT_OBJ_TYPE: 3740 switch (op) { 3741 case Audit_equal: 3742 match = (ctxt->type == rule->au_ctxt.type); 3743 break; 3744 case Audit_not_equal: 3745 match = (ctxt->type != rule->au_ctxt.type); 3746 break; 3747 } 3748 break; 3749 case AUDIT_SUBJ_SEN: 3750 case AUDIT_SUBJ_CLR: 3751 case AUDIT_OBJ_LEV_LOW: 3752 case AUDIT_OBJ_LEV_HIGH: 3753 level = ((field == AUDIT_SUBJ_SEN || 3754 field == AUDIT_OBJ_LEV_LOW) ? 3755 &ctxt->range.level[0] : &ctxt->range.level[1]); 3756 switch (op) { 3757 case Audit_equal: 3758 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3759 level); 3760 break; 3761 case Audit_not_equal: 3762 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3763 level); 3764 break; 3765 case Audit_lt: 3766 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3767 level) && 3768 !mls_level_eq(&rule->au_ctxt.range.level[0], 3769 level)); 3770 break; 3771 case Audit_le: 3772 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3773 level); 3774 break; 3775 case Audit_gt: 3776 match = (mls_level_dom(level, 3777 &rule->au_ctxt.range.level[0]) && 3778 !mls_level_eq(level, 3779 &rule->au_ctxt.range.level[0])); 3780 break; 3781 case Audit_ge: 3782 match = mls_level_dom(level, 3783 &rule->au_ctxt.range.level[0]); 3784 break; 3785 } 3786 } 3787 3788 out: 3789 rcu_read_unlock(); 3790 return match; 3791 } 3792 3793 static int aurule_avc_callback(u32 event) 3794 { 3795 if (event == AVC_CALLBACK_RESET) 3796 return audit_update_lsm_rules(); 3797 return 0; 3798 } 3799 3800 static int __init aurule_init(void) 3801 { 3802 int err; 3803 3804 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3805 if (err) 3806 panic("avc_add_callback() failed, error %d\n", err); 3807 3808 return err; 3809 } 3810 __initcall(aurule_init); 3811 3812 #ifdef CONFIG_NETLABEL 3813 /** 3814 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3815 * @secattr: the NetLabel packet security attributes 3816 * @sid: the SELinux SID 3817 * 3818 * Description: 3819 * Attempt to cache the context in @ctx, which was derived from the packet in 3820 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3821 * already been initialized. 3822 * 3823 */ 3824 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3825 u32 sid) 3826 { 3827 u32 *sid_cache; 3828 3829 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3830 if (sid_cache == NULL) 3831 return; 3832 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3833 if (secattr->cache == NULL) { 3834 kfree(sid_cache); 3835 return; 3836 } 3837 3838 *sid_cache = sid; 3839 secattr->cache->free = kfree; 3840 secattr->cache->data = sid_cache; 3841 secattr->flags |= NETLBL_SECATTR_CACHE; 3842 } 3843 3844 /** 3845 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3846 * @secattr: the NetLabel packet security attributes 3847 * @sid: the SELinux SID 3848 * 3849 * Description: 3850 * Convert the given NetLabel security attributes in @secattr into a 3851 * SELinux SID. If the @secattr field does not contain a full SELinux 3852 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3853 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3854 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3855 * conversion for future lookups. Returns zero on success, negative values on 3856 * failure. 3857 * 3858 */ 3859 int security_netlbl_secattr_to_sid(struct selinux_state *state, 3860 struct netlbl_lsm_secattr *secattr, 3861 u32 *sid) 3862 { 3863 struct selinux_policy *policy; 3864 struct policydb *policydb; 3865 struct sidtab *sidtab; 3866 int rc; 3867 struct context *ctx; 3868 struct context ctx_new; 3869 3870 if (!selinux_initialized(state)) { 3871 *sid = SECSID_NULL; 3872 return 0; 3873 } 3874 3875 retry: 3876 rc = 0; 3877 rcu_read_lock(); 3878 policy = rcu_dereference(state->policy); 3879 policydb = &policy->policydb; 3880 sidtab = policy->sidtab; 3881 3882 if (secattr->flags & NETLBL_SECATTR_CACHE) 3883 *sid = *(u32 *)secattr->cache->data; 3884 else if (secattr->flags & NETLBL_SECATTR_SECID) 3885 *sid = secattr->attr.secid; 3886 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3887 rc = -EIDRM; 3888 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3889 if (ctx == NULL) 3890 goto out; 3891 3892 context_init(&ctx_new); 3893 ctx_new.user = ctx->user; 3894 ctx_new.role = ctx->role; 3895 ctx_new.type = ctx->type; 3896 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3897 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3898 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3899 if (rc) 3900 goto out; 3901 } 3902 rc = -EIDRM; 3903 if (!mls_context_isvalid(policydb, &ctx_new)) { 3904 ebitmap_destroy(&ctx_new.range.level[0].cat); 3905 goto out; 3906 } 3907 3908 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3909 ebitmap_destroy(&ctx_new.range.level[0].cat); 3910 if (rc == -ESTALE) { 3911 rcu_read_unlock(); 3912 goto retry; 3913 } 3914 if (rc) 3915 goto out; 3916 3917 security_netlbl_cache_add(secattr, *sid); 3918 } else 3919 *sid = SECSID_NULL; 3920 3921 out: 3922 rcu_read_unlock(); 3923 return rc; 3924 } 3925 3926 /** 3927 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3928 * @sid: the SELinux SID 3929 * @secattr: the NetLabel packet security attributes 3930 * 3931 * Description: 3932 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3933 * Returns zero on success, negative values on failure. 3934 * 3935 */ 3936 int security_netlbl_sid_to_secattr(struct selinux_state *state, 3937 u32 sid, struct netlbl_lsm_secattr *secattr) 3938 { 3939 struct selinux_policy *policy; 3940 struct policydb *policydb; 3941 int rc; 3942 struct context *ctx; 3943 3944 if (!selinux_initialized(state)) 3945 return 0; 3946 3947 rcu_read_lock(); 3948 policy = rcu_dereference(state->policy); 3949 policydb = &policy->policydb; 3950 3951 rc = -ENOENT; 3952 ctx = sidtab_search(policy->sidtab, sid); 3953 if (ctx == NULL) 3954 goto out; 3955 3956 rc = -ENOMEM; 3957 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3958 GFP_ATOMIC); 3959 if (secattr->domain == NULL) 3960 goto out; 3961 3962 secattr->attr.secid = sid; 3963 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3964 mls_export_netlbl_lvl(policydb, ctx, secattr); 3965 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3966 out: 3967 rcu_read_unlock(); 3968 return rc; 3969 } 3970 #endif /* CONFIG_NETLABEL */ 3971 3972 /** 3973 * __security_read_policy - read the policy. 3974 * @policy: SELinux policy 3975 * @data: binary policy data 3976 * @len: length of data in bytes 3977 * 3978 */ 3979 static int __security_read_policy(struct selinux_policy *policy, 3980 void *data, size_t *len) 3981 { 3982 int rc; 3983 struct policy_file fp; 3984 3985 fp.data = data; 3986 fp.len = *len; 3987 3988 rc = policydb_write(&policy->policydb, &fp); 3989 if (rc) 3990 return rc; 3991 3992 *len = (unsigned long)fp.data - (unsigned long)data; 3993 return 0; 3994 } 3995 3996 /** 3997 * security_read_policy - read the policy. 3998 * @state: selinux_state 3999 * @data: binary policy data 4000 * @len: length of data in bytes 4001 * 4002 */ 4003 int security_read_policy(struct selinux_state *state, 4004 void **data, size_t *len) 4005 { 4006 struct selinux_policy *policy; 4007 4008 policy = rcu_dereference_protected( 4009 state->policy, lockdep_is_held(&state->policy_mutex)); 4010 if (!policy) 4011 return -EINVAL; 4012 4013 *len = policy->policydb.len; 4014 *data = vmalloc_user(*len); 4015 if (!*data) 4016 return -ENOMEM; 4017 4018 return __security_read_policy(policy, *data, len); 4019 } 4020 4021 /** 4022 * security_read_state_kernel - read the policy. 4023 * @state: selinux_state 4024 * @data: binary policy data 4025 * @len: length of data in bytes 4026 * 4027 * Allocates kernel memory for reading SELinux policy. 4028 * This function is for internal use only and should not 4029 * be used for returning data to user space. 4030 * 4031 * This function must be called with policy_mutex held. 4032 */ 4033 int security_read_state_kernel(struct selinux_state *state, 4034 void **data, size_t *len) 4035 { 4036 struct selinux_policy *policy; 4037 4038 policy = rcu_dereference_protected( 4039 state->policy, lockdep_is_held(&state->policy_mutex)); 4040 if (!policy) 4041 return -EINVAL; 4042 4043 *len = policy->policydb.len; 4044 *data = vmalloc(*len); 4045 if (!*data) 4046 return -ENOMEM; 4047 4048 return __security_read_policy(policy, *data, len); 4049 } 4050