1 /* 2 * Implementation of the security services. 3 * 4 * Authors : Stephen Smalley, <sds@tycho.nsa.gov> 5 * James Morris <jmorris@redhat.com> 6 * 7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> 8 * 9 * Support for enhanced MLS infrastructure. 10 * Support for context based audit filters. 11 * 12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> 13 * 14 * Added conditional policy language extensions 15 * 16 * Updated: Hewlett-Packard <paul@paul-moore.com> 17 * 18 * Added support for NetLabel 19 * Added support for the policy capability bitmap 20 * 21 * Updated: Chad Sellers <csellers@tresys.com> 22 * 23 * Added validation of kernel classes and permissions 24 * 25 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> 26 * 27 * Added support for bounds domain and audit messaged on masked permissions 28 * 29 * Updated: Guido Trentalancia <guido@trentalancia.com> 30 * 31 * Added support for runtime switching of the policy type 32 * 33 * Copyright (C) 2008, 2009 NEC Corporation 34 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. 35 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. 36 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC 37 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> 38 * This program is free software; you can redistribute it and/or modify 39 * it under the terms of the GNU General Public License as published by 40 * the Free Software Foundation, version 2. 41 */ 42 #include <linux/kernel.h> 43 #include <linux/slab.h> 44 #include <linux/string.h> 45 #include <linux/spinlock.h> 46 #include <linux/rcupdate.h> 47 #include <linux/errno.h> 48 #include <linux/in.h> 49 #include <linux/sched.h> 50 #include <linux/audit.h> 51 #include <linux/mutex.h> 52 #include <linux/flex_array.h> 53 #include <linux/vmalloc.h> 54 #include <net/netlabel.h> 55 56 #include "flask.h" 57 #include "avc.h" 58 #include "avc_ss.h" 59 #include "security.h" 60 #include "context.h" 61 #include "policydb.h" 62 #include "sidtab.h" 63 #include "services.h" 64 #include "conditional.h" 65 #include "mls.h" 66 #include "objsec.h" 67 #include "netlabel.h" 68 #include "xfrm.h" 69 #include "ebitmap.h" 70 #include "audit.h" 71 72 /* Policy capability names */ 73 const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = { 74 "network_peer_controls", 75 "open_perms", 76 "extended_socket_class", 77 "always_check_network", 78 "cgroup_seclabel", 79 "nnp_nosuid_transition" 80 }; 81 82 static struct selinux_ss selinux_ss; 83 84 void selinux_ss_init(struct selinux_ss **ss) 85 { 86 rwlock_init(&selinux_ss.policy_rwlock); 87 mutex_init(&selinux_ss.status_lock); 88 *ss = &selinux_ss; 89 } 90 91 /* Forward declaration. */ 92 static int context_struct_to_string(struct policydb *policydb, 93 struct context *context, 94 char **scontext, 95 u32 *scontext_len); 96 97 static void context_struct_compute_av(struct policydb *policydb, 98 struct context *scontext, 99 struct context *tcontext, 100 u16 tclass, 101 struct av_decision *avd, 102 struct extended_perms *xperms); 103 104 static int selinux_set_mapping(struct policydb *pol, 105 struct security_class_mapping *map, 106 struct selinux_map *out_map) 107 { 108 u16 i, j; 109 unsigned k; 110 bool print_unknown_handle = false; 111 112 /* Find number of classes in the input mapping */ 113 if (!map) 114 return -EINVAL; 115 i = 0; 116 while (map[i].name) 117 i++; 118 119 /* Allocate space for the class records, plus one for class zero */ 120 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 121 if (!out_map->mapping) 122 return -ENOMEM; 123 124 /* Store the raw class and permission values */ 125 j = 0; 126 while (map[j].name) { 127 struct security_class_mapping *p_in = map + (j++); 128 struct selinux_mapping *p_out = out_map->mapping + j; 129 130 /* An empty class string skips ahead */ 131 if (!strcmp(p_in->name, "")) { 132 p_out->num_perms = 0; 133 continue; 134 } 135 136 p_out->value = string_to_security_class(pol, p_in->name); 137 if (!p_out->value) { 138 pr_info("SELinux: Class %s not defined in policy.\n", 139 p_in->name); 140 if (pol->reject_unknown) 141 goto err; 142 p_out->num_perms = 0; 143 print_unknown_handle = true; 144 continue; 145 } 146 147 k = 0; 148 while (p_in->perms[k]) { 149 /* An empty permission string skips ahead */ 150 if (!*p_in->perms[k]) { 151 k++; 152 continue; 153 } 154 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 155 p_in->perms[k]); 156 if (!p_out->perms[k]) { 157 pr_info("SELinux: Permission %s in class %s not defined in policy.\n", 158 p_in->perms[k], p_in->name); 159 if (pol->reject_unknown) 160 goto err; 161 print_unknown_handle = true; 162 } 163 164 k++; 165 } 166 p_out->num_perms = k; 167 } 168 169 if (print_unknown_handle) 170 pr_info("SELinux: the above unknown classes and permissions will be %s\n", 171 pol->allow_unknown ? "allowed" : "denied"); 172 173 out_map->size = i; 174 return 0; 175 err: 176 kfree(out_map->mapping); 177 out_map->mapping = NULL; 178 return -EINVAL; 179 } 180 181 /* 182 * Get real, policy values from mapped values 183 */ 184 185 static u16 unmap_class(struct selinux_map *map, u16 tclass) 186 { 187 if (tclass < map->size) 188 return map->mapping[tclass].value; 189 190 return tclass; 191 } 192 193 /* 194 * Get kernel value for class from its policy value 195 */ 196 static u16 map_class(struct selinux_map *map, u16 pol_value) 197 { 198 u16 i; 199 200 for (i = 1; i < map->size; i++) { 201 if (map->mapping[i].value == pol_value) 202 return i; 203 } 204 205 return SECCLASS_NULL; 206 } 207 208 static void map_decision(struct selinux_map *map, 209 u16 tclass, struct av_decision *avd, 210 int allow_unknown) 211 { 212 if (tclass < map->size) { 213 struct selinux_mapping *mapping = &map->mapping[tclass]; 214 unsigned int i, n = mapping->num_perms; 215 u32 result; 216 217 for (i = 0, result = 0; i < n; i++) { 218 if (avd->allowed & mapping->perms[i]) 219 result |= 1<<i; 220 if (allow_unknown && !mapping->perms[i]) 221 result |= 1<<i; 222 } 223 avd->allowed = result; 224 225 for (i = 0, result = 0; i < n; i++) 226 if (avd->auditallow & mapping->perms[i]) 227 result |= 1<<i; 228 avd->auditallow = result; 229 230 for (i = 0, result = 0; i < n; i++) { 231 if (avd->auditdeny & mapping->perms[i]) 232 result |= 1<<i; 233 if (!allow_unknown && !mapping->perms[i]) 234 result |= 1<<i; 235 } 236 /* 237 * In case the kernel has a bug and requests a permission 238 * between num_perms and the maximum permission number, we 239 * should audit that denial 240 */ 241 for (; i < (sizeof(u32)*8); i++) 242 result |= 1<<i; 243 avd->auditdeny = result; 244 } 245 } 246 247 int security_mls_enabled(struct selinux_state *state) 248 { 249 struct policydb *p = &state->ss->policydb; 250 251 return p->mls_enabled; 252 } 253 254 /* 255 * Return the boolean value of a constraint expression 256 * when it is applied to the specified source and target 257 * security contexts. 258 * 259 * xcontext is a special beast... It is used by the validatetrans rules 260 * only. For these rules, scontext is the context before the transition, 261 * tcontext is the context after the transition, and xcontext is the context 262 * of the process performing the transition. All other callers of 263 * constraint_expr_eval should pass in NULL for xcontext. 264 */ 265 static int constraint_expr_eval(struct policydb *policydb, 266 struct context *scontext, 267 struct context *tcontext, 268 struct context *xcontext, 269 struct constraint_expr *cexpr) 270 { 271 u32 val1, val2; 272 struct context *c; 273 struct role_datum *r1, *r2; 274 struct mls_level *l1, *l2; 275 struct constraint_expr *e; 276 int s[CEXPR_MAXDEPTH]; 277 int sp = -1; 278 279 for (e = cexpr; e; e = e->next) { 280 switch (e->expr_type) { 281 case CEXPR_NOT: 282 BUG_ON(sp < 0); 283 s[sp] = !s[sp]; 284 break; 285 case CEXPR_AND: 286 BUG_ON(sp < 1); 287 sp--; 288 s[sp] &= s[sp + 1]; 289 break; 290 case CEXPR_OR: 291 BUG_ON(sp < 1); 292 sp--; 293 s[sp] |= s[sp + 1]; 294 break; 295 case CEXPR_ATTR: 296 if (sp == (CEXPR_MAXDEPTH - 1)) 297 return 0; 298 switch (e->attr) { 299 case CEXPR_USER: 300 val1 = scontext->user; 301 val2 = tcontext->user; 302 break; 303 case CEXPR_TYPE: 304 val1 = scontext->type; 305 val2 = tcontext->type; 306 break; 307 case CEXPR_ROLE: 308 val1 = scontext->role; 309 val2 = tcontext->role; 310 r1 = policydb->role_val_to_struct[val1 - 1]; 311 r2 = policydb->role_val_to_struct[val2 - 1]; 312 switch (e->op) { 313 case CEXPR_DOM: 314 s[++sp] = ebitmap_get_bit(&r1->dominates, 315 val2 - 1); 316 continue; 317 case CEXPR_DOMBY: 318 s[++sp] = ebitmap_get_bit(&r2->dominates, 319 val1 - 1); 320 continue; 321 case CEXPR_INCOMP: 322 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 323 val2 - 1) && 324 !ebitmap_get_bit(&r2->dominates, 325 val1 - 1)); 326 continue; 327 default: 328 break; 329 } 330 break; 331 case CEXPR_L1L2: 332 l1 = &(scontext->range.level[0]); 333 l2 = &(tcontext->range.level[0]); 334 goto mls_ops; 335 case CEXPR_L1H2: 336 l1 = &(scontext->range.level[0]); 337 l2 = &(tcontext->range.level[1]); 338 goto mls_ops; 339 case CEXPR_H1L2: 340 l1 = &(scontext->range.level[1]); 341 l2 = &(tcontext->range.level[0]); 342 goto mls_ops; 343 case CEXPR_H1H2: 344 l1 = &(scontext->range.level[1]); 345 l2 = &(tcontext->range.level[1]); 346 goto mls_ops; 347 case CEXPR_L1H1: 348 l1 = &(scontext->range.level[0]); 349 l2 = &(scontext->range.level[1]); 350 goto mls_ops; 351 case CEXPR_L2H2: 352 l1 = &(tcontext->range.level[0]); 353 l2 = &(tcontext->range.level[1]); 354 goto mls_ops; 355 mls_ops: 356 switch (e->op) { 357 case CEXPR_EQ: 358 s[++sp] = mls_level_eq(l1, l2); 359 continue; 360 case CEXPR_NEQ: 361 s[++sp] = !mls_level_eq(l1, l2); 362 continue; 363 case CEXPR_DOM: 364 s[++sp] = mls_level_dom(l1, l2); 365 continue; 366 case CEXPR_DOMBY: 367 s[++sp] = mls_level_dom(l2, l1); 368 continue; 369 case CEXPR_INCOMP: 370 s[++sp] = mls_level_incomp(l2, l1); 371 continue; 372 default: 373 BUG(); 374 return 0; 375 } 376 break; 377 default: 378 BUG(); 379 return 0; 380 } 381 382 switch (e->op) { 383 case CEXPR_EQ: 384 s[++sp] = (val1 == val2); 385 break; 386 case CEXPR_NEQ: 387 s[++sp] = (val1 != val2); 388 break; 389 default: 390 BUG(); 391 return 0; 392 } 393 break; 394 case CEXPR_NAMES: 395 if (sp == (CEXPR_MAXDEPTH-1)) 396 return 0; 397 c = scontext; 398 if (e->attr & CEXPR_TARGET) 399 c = tcontext; 400 else if (e->attr & CEXPR_XTARGET) { 401 c = xcontext; 402 if (!c) { 403 BUG(); 404 return 0; 405 } 406 } 407 if (e->attr & CEXPR_USER) 408 val1 = c->user; 409 else if (e->attr & CEXPR_ROLE) 410 val1 = c->role; 411 else if (e->attr & CEXPR_TYPE) 412 val1 = c->type; 413 else { 414 BUG(); 415 return 0; 416 } 417 418 switch (e->op) { 419 case CEXPR_EQ: 420 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 421 break; 422 case CEXPR_NEQ: 423 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 424 break; 425 default: 426 BUG(); 427 return 0; 428 } 429 break; 430 default: 431 BUG(); 432 return 0; 433 } 434 } 435 436 BUG_ON(sp != 0); 437 return s[0]; 438 } 439 440 /* 441 * security_dump_masked_av - dumps masked permissions during 442 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 443 */ 444 static int dump_masked_av_helper(void *k, void *d, void *args) 445 { 446 struct perm_datum *pdatum = d; 447 char **permission_names = args; 448 449 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 450 451 permission_names[pdatum->value - 1] = (char *)k; 452 453 return 0; 454 } 455 456 static void security_dump_masked_av(struct policydb *policydb, 457 struct context *scontext, 458 struct context *tcontext, 459 u16 tclass, 460 u32 permissions, 461 const char *reason) 462 { 463 struct common_datum *common_dat; 464 struct class_datum *tclass_dat; 465 struct audit_buffer *ab; 466 char *tclass_name; 467 char *scontext_name = NULL; 468 char *tcontext_name = NULL; 469 char *permission_names[32]; 470 int index; 471 u32 length; 472 bool need_comma = false; 473 474 if (!permissions) 475 return; 476 477 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); 478 tclass_dat = policydb->class_val_to_struct[tclass - 1]; 479 common_dat = tclass_dat->comdatum; 480 481 /* init permission_names */ 482 if (common_dat && 483 hashtab_map(common_dat->permissions.table, 484 dump_masked_av_helper, permission_names) < 0) 485 goto out; 486 487 if (hashtab_map(tclass_dat->permissions.table, 488 dump_masked_av_helper, permission_names) < 0) 489 goto out; 490 491 /* get scontext/tcontext in text form */ 492 if (context_struct_to_string(policydb, scontext, 493 &scontext_name, &length) < 0) 494 goto out; 495 496 if (context_struct_to_string(policydb, tcontext, 497 &tcontext_name, &length) < 0) 498 goto out; 499 500 /* audit a message */ 501 ab = audit_log_start(audit_context(), 502 GFP_ATOMIC, AUDIT_SELINUX_ERR); 503 if (!ab) 504 goto out; 505 506 audit_log_format(ab, "op=security_compute_av reason=%s " 507 "scontext=%s tcontext=%s tclass=%s perms=", 508 reason, scontext_name, tcontext_name, tclass_name); 509 510 for (index = 0; index < 32; index++) { 511 u32 mask = (1 << index); 512 513 if ((mask & permissions) == 0) 514 continue; 515 516 audit_log_format(ab, "%s%s", 517 need_comma ? "," : "", 518 permission_names[index] 519 ? permission_names[index] : "????"); 520 need_comma = true; 521 } 522 audit_log_end(ab); 523 out: 524 /* release scontext/tcontext */ 525 kfree(tcontext_name); 526 kfree(scontext_name); 527 528 return; 529 } 530 531 /* 532 * security_boundary_permission - drops violated permissions 533 * on boundary constraint. 534 */ 535 static void type_attribute_bounds_av(struct policydb *policydb, 536 struct context *scontext, 537 struct context *tcontext, 538 u16 tclass, 539 struct av_decision *avd) 540 { 541 struct context lo_scontext; 542 struct context lo_tcontext, *tcontextp = tcontext; 543 struct av_decision lo_avd; 544 struct type_datum *source; 545 struct type_datum *target; 546 u32 masked = 0; 547 548 source = flex_array_get_ptr(policydb->type_val_to_struct_array, 549 scontext->type - 1); 550 BUG_ON(!source); 551 552 if (!source->bounds) 553 return; 554 555 target = flex_array_get_ptr(policydb->type_val_to_struct_array, 556 tcontext->type - 1); 557 BUG_ON(!target); 558 559 memset(&lo_avd, 0, sizeof(lo_avd)); 560 561 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 562 lo_scontext.type = source->bounds; 563 564 if (target->bounds) { 565 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 566 lo_tcontext.type = target->bounds; 567 tcontextp = &lo_tcontext; 568 } 569 570 context_struct_compute_av(policydb, &lo_scontext, 571 tcontextp, 572 tclass, 573 &lo_avd, 574 NULL); 575 576 masked = ~lo_avd.allowed & avd->allowed; 577 578 if (likely(!masked)) 579 return; /* no masked permission */ 580 581 /* mask violated permissions */ 582 avd->allowed &= ~masked; 583 584 /* audit masked permissions */ 585 security_dump_masked_av(policydb, scontext, tcontext, 586 tclass, masked, "bounds"); 587 } 588 589 /* 590 * flag which drivers have permissions 591 * only looking for ioctl based extended permssions 592 */ 593 void services_compute_xperms_drivers( 594 struct extended_perms *xperms, 595 struct avtab_node *node) 596 { 597 unsigned int i; 598 599 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 600 /* if one or more driver has all permissions allowed */ 601 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 602 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 603 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 604 /* if allowing permissions within a driver */ 605 security_xperm_set(xperms->drivers.p, 606 node->datum.u.xperms->driver); 607 } 608 609 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */ 610 if (node->key.specified & AVTAB_XPERMS_ALLOWED) 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 = flex_array_get(policydb->type_attr_map_array, 657 scontext->type - 1); 658 BUG_ON(!sattr); 659 tattr = flex_array_get(policydb->type_attr_map_array, 660 tcontext->type - 1); 661 BUG_ON(!tattr); 662 ebitmap_for_each_positive_bit(sattr, snode, i) { 663 ebitmap_for_each_positive_bit(tattr, tnode, j) { 664 avkey.source_type = i + 1; 665 avkey.target_type = j + 1; 666 for (node = avtab_search_node(&policydb->te_avtab, 667 &avkey); 668 node; 669 node = avtab_search_node_next(node, avkey.specified)) { 670 if (node->key.specified == AVTAB_ALLOWED) 671 avd->allowed |= node->datum.u.data; 672 else if (node->key.specified == AVTAB_AUDITALLOW) 673 avd->auditallow |= node->datum.u.data; 674 else if (node->key.specified == AVTAB_AUDITDENY) 675 avd->auditdeny &= node->datum.u.data; 676 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 677 services_compute_xperms_drivers(xperms, node); 678 } 679 680 /* Check conditional av table for additional permissions */ 681 cond_compute_av(&policydb->te_cond_avtab, &avkey, 682 avd, xperms); 683 684 } 685 } 686 687 /* 688 * Remove any permissions prohibited by a constraint (this includes 689 * the MLS policy). 690 */ 691 constraint = tclass_datum->constraints; 692 while (constraint) { 693 if ((constraint->permissions & (avd->allowed)) && 694 !constraint_expr_eval(policydb, scontext, tcontext, NULL, 695 constraint->expr)) { 696 avd->allowed &= ~(constraint->permissions); 697 } 698 constraint = constraint->next; 699 } 700 701 /* 702 * If checking process transition permission and the 703 * role is changing, then check the (current_role, new_role) 704 * pair. 705 */ 706 if (tclass == policydb->process_class && 707 (avd->allowed & policydb->process_trans_perms) && 708 scontext->role != tcontext->role) { 709 for (ra = policydb->role_allow; ra; ra = ra->next) { 710 if (scontext->role == ra->role && 711 tcontext->role == ra->new_role) 712 break; 713 } 714 if (!ra) 715 avd->allowed &= ~policydb->process_trans_perms; 716 } 717 718 /* 719 * If the given source and target types have boundary 720 * constraint, lazy checks have to mask any violated 721 * permission and notice it to userspace via audit. 722 */ 723 type_attribute_bounds_av(policydb, scontext, tcontext, 724 tclass, avd); 725 } 726 727 static int security_validtrans_handle_fail(struct selinux_state *state, 728 struct context *ocontext, 729 struct context *ncontext, 730 struct context *tcontext, 731 u16 tclass) 732 { 733 struct policydb *p = &state->ss->policydb; 734 char *o = NULL, *n = NULL, *t = NULL; 735 u32 olen, nlen, tlen; 736 737 if (context_struct_to_string(p, ocontext, &o, &olen)) 738 goto out; 739 if (context_struct_to_string(p, ncontext, &n, &nlen)) 740 goto out; 741 if (context_struct_to_string(p, tcontext, &t, &tlen)) 742 goto out; 743 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 744 "op=security_validate_transition seresult=denied" 745 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 746 o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); 747 out: 748 kfree(o); 749 kfree(n); 750 kfree(t); 751 752 if (!enforcing_enabled(state)) 753 return 0; 754 return -EPERM; 755 } 756 757 static int security_compute_validatetrans(struct selinux_state *state, 758 u32 oldsid, u32 newsid, u32 tasksid, 759 u16 orig_tclass, bool user) 760 { 761 struct policydb *policydb; 762 struct sidtab *sidtab; 763 struct context *ocontext; 764 struct context *ncontext; 765 struct context *tcontext; 766 struct class_datum *tclass_datum; 767 struct constraint_node *constraint; 768 u16 tclass; 769 int rc = 0; 770 771 772 if (!state->initialized) 773 return 0; 774 775 read_lock(&state->ss->policy_rwlock); 776 777 policydb = &state->ss->policydb; 778 sidtab = state->ss->sidtab; 779 780 if (!user) 781 tclass = unmap_class(&state->ss->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 ocontext = sidtab_search(sidtab, oldsid); 792 if (!ocontext) { 793 pr_err("SELinux: %s: unrecognized SID %d\n", 794 __func__, oldsid); 795 rc = -EINVAL; 796 goto out; 797 } 798 799 ncontext = sidtab_search(sidtab, newsid); 800 if (!ncontext) { 801 pr_err("SELinux: %s: unrecognized SID %d\n", 802 __func__, newsid); 803 rc = -EINVAL; 804 goto out; 805 } 806 807 tcontext = sidtab_search(sidtab, tasksid); 808 if (!tcontext) { 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, ocontext, ncontext, 818 tcontext, constraint->expr)) { 819 if (user) 820 rc = -EPERM; 821 else 822 rc = security_validtrans_handle_fail(state, 823 ocontext, 824 ncontext, 825 tcontext, 826 tclass); 827 goto out; 828 } 829 constraint = constraint->next; 830 } 831 832 out: 833 read_unlock(&state->ss->policy_rwlock); 834 return rc; 835 } 836 837 int security_validate_transition_user(struct selinux_state *state, 838 u32 oldsid, u32 newsid, u32 tasksid, 839 u16 tclass) 840 { 841 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 842 tclass, true); 843 } 844 845 int security_validate_transition(struct selinux_state *state, 846 u32 oldsid, u32 newsid, u32 tasksid, 847 u16 orig_tclass) 848 { 849 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 850 orig_tclass, false); 851 } 852 853 /* 854 * security_bounded_transition - check whether the given 855 * transition is directed to bounded, or not. 856 * It returns 0, if @newsid is bounded by @oldsid. 857 * Otherwise, it returns error code. 858 * 859 * @oldsid : current security identifier 860 * @newsid : destinated security identifier 861 */ 862 int security_bounded_transition(struct selinux_state *state, 863 u32 old_sid, u32 new_sid) 864 { 865 struct policydb *policydb; 866 struct sidtab *sidtab; 867 struct context *old_context, *new_context; 868 struct type_datum *type; 869 int index; 870 int rc; 871 872 if (!state->initialized) 873 return 0; 874 875 read_lock(&state->ss->policy_rwlock); 876 877 policydb = &state->ss->policydb; 878 sidtab = state->ss->sidtab; 879 880 rc = -EINVAL; 881 old_context = sidtab_search(sidtab, old_sid); 882 if (!old_context) { 883 pr_err("SELinux: %s: unrecognized SID %u\n", 884 __func__, old_sid); 885 goto out; 886 } 887 888 rc = -EINVAL; 889 new_context = sidtab_search(sidtab, new_sid); 890 if (!new_context) { 891 pr_err("SELinux: %s: unrecognized SID %u\n", 892 __func__, new_sid); 893 goto out; 894 } 895 896 rc = 0; 897 /* type/domain unchanged */ 898 if (old_context->type == new_context->type) 899 goto out; 900 901 index = new_context->type; 902 while (true) { 903 type = flex_array_get_ptr(policydb->type_val_to_struct_array, 904 index - 1); 905 BUG_ON(!type); 906 907 /* not bounded anymore */ 908 rc = -EPERM; 909 if (!type->bounds) 910 break; 911 912 /* @newsid is bounded by @oldsid */ 913 rc = 0; 914 if (type->bounds == old_context->type) 915 break; 916 917 index = type->bounds; 918 } 919 920 if (rc) { 921 char *old_name = NULL; 922 char *new_name = NULL; 923 u32 length; 924 925 if (!context_struct_to_string(policydb, old_context, 926 &old_name, &length) && 927 !context_struct_to_string(policydb, new_context, 928 &new_name, &length)) { 929 audit_log(audit_context(), 930 GFP_ATOMIC, AUDIT_SELINUX_ERR, 931 "op=security_bounded_transition " 932 "seresult=denied " 933 "oldcontext=%s newcontext=%s", 934 old_name, new_name); 935 } 936 kfree(new_name); 937 kfree(old_name); 938 } 939 out: 940 read_unlock(&state->ss->policy_rwlock); 941 942 return rc; 943 } 944 945 static void avd_init(struct selinux_state *state, struct av_decision *avd) 946 { 947 avd->allowed = 0; 948 avd->auditallow = 0; 949 avd->auditdeny = 0xffffffff; 950 avd->seqno = state->ss->latest_granting; 951 avd->flags = 0; 952 } 953 954 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 955 struct avtab_node *node) 956 { 957 unsigned int i; 958 959 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 960 if (xpermd->driver != node->datum.u.xperms->driver) 961 return; 962 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 963 if (!security_xperm_test(node->datum.u.xperms->perms.p, 964 xpermd->driver)) 965 return; 966 } else { 967 BUG(); 968 } 969 970 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 971 xpermd->used |= XPERMS_ALLOWED; 972 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 973 memset(xpermd->allowed->p, 0xff, 974 sizeof(xpermd->allowed->p)); 975 } 976 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 977 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 978 xpermd->allowed->p[i] |= 979 node->datum.u.xperms->perms.p[i]; 980 } 981 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 982 xpermd->used |= XPERMS_AUDITALLOW; 983 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 984 memset(xpermd->auditallow->p, 0xff, 985 sizeof(xpermd->auditallow->p)); 986 } 987 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 988 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 989 xpermd->auditallow->p[i] |= 990 node->datum.u.xperms->perms.p[i]; 991 } 992 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 993 xpermd->used |= XPERMS_DONTAUDIT; 994 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 995 memset(xpermd->dontaudit->p, 0xff, 996 sizeof(xpermd->dontaudit->p)); 997 } 998 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 999 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 1000 xpermd->dontaudit->p[i] |= 1001 node->datum.u.xperms->perms.p[i]; 1002 } 1003 } else { 1004 BUG(); 1005 } 1006 } 1007 1008 void security_compute_xperms_decision(struct selinux_state *state, 1009 u32 ssid, 1010 u32 tsid, 1011 u16 orig_tclass, 1012 u8 driver, 1013 struct extended_perms_decision *xpermd) 1014 { 1015 struct policydb *policydb; 1016 struct sidtab *sidtab; 1017 u16 tclass; 1018 struct context *scontext, *tcontext; 1019 struct avtab_key avkey; 1020 struct avtab_node *node; 1021 struct ebitmap *sattr, *tattr; 1022 struct ebitmap_node *snode, *tnode; 1023 unsigned int i, j; 1024 1025 xpermd->driver = driver; 1026 xpermd->used = 0; 1027 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1028 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1029 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1030 1031 read_lock(&state->ss->policy_rwlock); 1032 if (!state->initialized) 1033 goto allow; 1034 1035 policydb = &state->ss->policydb; 1036 sidtab = state->ss->sidtab; 1037 1038 scontext = sidtab_search(sidtab, ssid); 1039 if (!scontext) { 1040 pr_err("SELinux: %s: unrecognized SID %d\n", 1041 __func__, ssid); 1042 goto out; 1043 } 1044 1045 tcontext = sidtab_search(sidtab, tsid); 1046 if (!tcontext) { 1047 pr_err("SELinux: %s: unrecognized SID %d\n", 1048 __func__, tsid); 1049 goto out; 1050 } 1051 1052 tclass = unmap_class(&state->ss->map, orig_tclass); 1053 if (unlikely(orig_tclass && !tclass)) { 1054 if (policydb->allow_unknown) 1055 goto allow; 1056 goto out; 1057 } 1058 1059 1060 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1061 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1062 goto out; 1063 } 1064 1065 avkey.target_class = tclass; 1066 avkey.specified = AVTAB_XPERMS; 1067 sattr = flex_array_get(policydb->type_attr_map_array, 1068 scontext->type - 1); 1069 BUG_ON(!sattr); 1070 tattr = flex_array_get(policydb->type_attr_map_array, 1071 tcontext->type - 1); 1072 BUG_ON(!tattr); 1073 ebitmap_for_each_positive_bit(sattr, snode, i) { 1074 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1075 avkey.source_type = i + 1; 1076 avkey.target_type = j + 1; 1077 for (node = avtab_search_node(&policydb->te_avtab, 1078 &avkey); 1079 node; 1080 node = avtab_search_node_next(node, avkey.specified)) 1081 services_compute_xperms_decision(xpermd, node); 1082 1083 cond_compute_xperms(&policydb->te_cond_avtab, 1084 &avkey, xpermd); 1085 } 1086 } 1087 out: 1088 read_unlock(&state->ss->policy_rwlock); 1089 return; 1090 allow: 1091 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1092 goto out; 1093 } 1094 1095 /** 1096 * security_compute_av - Compute access vector decisions. 1097 * @ssid: source security identifier 1098 * @tsid: target security identifier 1099 * @tclass: target security class 1100 * @avd: access vector decisions 1101 * @xperms: extended permissions 1102 * 1103 * Compute a set of access vector decisions based on the 1104 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1105 */ 1106 void security_compute_av(struct selinux_state *state, 1107 u32 ssid, 1108 u32 tsid, 1109 u16 orig_tclass, 1110 struct av_decision *avd, 1111 struct extended_perms *xperms) 1112 { 1113 struct policydb *policydb; 1114 struct sidtab *sidtab; 1115 u16 tclass; 1116 struct context *scontext = NULL, *tcontext = NULL; 1117 1118 read_lock(&state->ss->policy_rwlock); 1119 avd_init(state, avd); 1120 xperms->len = 0; 1121 if (!state->initialized) 1122 goto allow; 1123 1124 policydb = &state->ss->policydb; 1125 sidtab = state->ss->sidtab; 1126 1127 scontext = sidtab_search(sidtab, ssid); 1128 if (!scontext) { 1129 pr_err("SELinux: %s: unrecognized SID %d\n", 1130 __func__, ssid); 1131 goto out; 1132 } 1133 1134 /* permissive domain? */ 1135 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1136 avd->flags |= AVD_FLAGS_PERMISSIVE; 1137 1138 tcontext = sidtab_search(sidtab, tsid); 1139 if (!tcontext) { 1140 pr_err("SELinux: %s: unrecognized SID %d\n", 1141 __func__, tsid); 1142 goto out; 1143 } 1144 1145 tclass = unmap_class(&state->ss->map, orig_tclass); 1146 if (unlikely(orig_tclass && !tclass)) { 1147 if (policydb->allow_unknown) 1148 goto allow; 1149 goto out; 1150 } 1151 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1152 xperms); 1153 map_decision(&state->ss->map, orig_tclass, avd, 1154 policydb->allow_unknown); 1155 out: 1156 read_unlock(&state->ss->policy_rwlock); 1157 return; 1158 allow: 1159 avd->allowed = 0xffffffff; 1160 goto out; 1161 } 1162 1163 void security_compute_av_user(struct selinux_state *state, 1164 u32 ssid, 1165 u32 tsid, 1166 u16 tclass, 1167 struct av_decision *avd) 1168 { 1169 struct policydb *policydb; 1170 struct sidtab *sidtab; 1171 struct context *scontext = NULL, *tcontext = NULL; 1172 1173 read_lock(&state->ss->policy_rwlock); 1174 avd_init(state, avd); 1175 if (!state->initialized) 1176 goto allow; 1177 1178 policydb = &state->ss->policydb; 1179 sidtab = state->ss->sidtab; 1180 1181 scontext = sidtab_search(sidtab, ssid); 1182 if (!scontext) { 1183 pr_err("SELinux: %s: unrecognized SID %d\n", 1184 __func__, ssid); 1185 goto out; 1186 } 1187 1188 /* permissive domain? */ 1189 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1190 avd->flags |= AVD_FLAGS_PERMISSIVE; 1191 1192 tcontext = sidtab_search(sidtab, tsid); 1193 if (!tcontext) { 1194 pr_err("SELinux: %s: unrecognized SID %d\n", 1195 __func__, tsid); 1196 goto out; 1197 } 1198 1199 if (unlikely(!tclass)) { 1200 if (policydb->allow_unknown) 1201 goto allow; 1202 goto out; 1203 } 1204 1205 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1206 NULL); 1207 out: 1208 read_unlock(&state->ss->policy_rwlock); 1209 return; 1210 allow: 1211 avd->allowed = 0xffffffff; 1212 goto out; 1213 } 1214 1215 /* 1216 * Write the security context string representation of 1217 * the context structure `context' into a dynamically 1218 * allocated string of the correct size. Set `*scontext' 1219 * to point to this string and set `*scontext_len' to 1220 * the length of the string. 1221 */ 1222 static int context_struct_to_string(struct policydb *p, 1223 struct context *context, 1224 char **scontext, u32 *scontext_len) 1225 { 1226 char *scontextp; 1227 1228 if (scontext) 1229 *scontext = NULL; 1230 *scontext_len = 0; 1231 1232 if (context->len) { 1233 *scontext_len = context->len; 1234 if (scontext) { 1235 *scontext = kstrdup(context->str, GFP_ATOMIC); 1236 if (!(*scontext)) 1237 return -ENOMEM; 1238 } 1239 return 0; 1240 } 1241 1242 /* Compute the size of the context. */ 1243 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1244 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1245 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1246 *scontext_len += mls_compute_context_len(p, context); 1247 1248 if (!scontext) 1249 return 0; 1250 1251 /* Allocate space for the context; caller must free this space. */ 1252 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1253 if (!scontextp) 1254 return -ENOMEM; 1255 *scontext = scontextp; 1256 1257 /* 1258 * Copy the user name, role name and type name into the context. 1259 */ 1260 scontextp += sprintf(scontextp, "%s:%s:%s", 1261 sym_name(p, SYM_USERS, context->user - 1), 1262 sym_name(p, SYM_ROLES, context->role - 1), 1263 sym_name(p, SYM_TYPES, context->type - 1)); 1264 1265 mls_sid_to_context(p, context, &scontextp); 1266 1267 *scontextp = 0; 1268 1269 return 0; 1270 } 1271 1272 #include "initial_sid_to_string.h" 1273 1274 const char *security_get_initial_sid_context(u32 sid) 1275 { 1276 if (unlikely(sid > SECINITSID_NUM)) 1277 return NULL; 1278 return initial_sid_to_string[sid]; 1279 } 1280 1281 static int security_sid_to_context_core(struct selinux_state *state, 1282 u32 sid, char **scontext, 1283 u32 *scontext_len, int force, 1284 int only_invalid) 1285 { 1286 struct policydb *policydb; 1287 struct sidtab *sidtab; 1288 struct context *context; 1289 int rc = 0; 1290 1291 if (scontext) 1292 *scontext = NULL; 1293 *scontext_len = 0; 1294 1295 if (!state->initialized) { 1296 if (sid <= SECINITSID_NUM) { 1297 char *scontextp; 1298 1299 *scontext_len = strlen(initial_sid_to_string[sid]) + 1; 1300 if (!scontext) 1301 goto out; 1302 scontextp = kmemdup(initial_sid_to_string[sid], 1303 *scontext_len, GFP_ATOMIC); 1304 if (!scontextp) { 1305 rc = -ENOMEM; 1306 goto out; 1307 } 1308 *scontext = scontextp; 1309 goto out; 1310 } 1311 pr_err("SELinux: %s: called before initial " 1312 "load_policy on unknown SID %d\n", __func__, sid); 1313 rc = -EINVAL; 1314 goto out; 1315 } 1316 read_lock(&state->ss->policy_rwlock); 1317 policydb = &state->ss->policydb; 1318 sidtab = state->ss->sidtab; 1319 if (force) 1320 context = sidtab_search_force(sidtab, sid); 1321 else 1322 context = sidtab_search(sidtab, sid); 1323 if (!context) { 1324 pr_err("SELinux: %s: unrecognized SID %d\n", 1325 __func__, sid); 1326 rc = -EINVAL; 1327 goto out_unlock; 1328 } 1329 if (only_invalid && !context->len) { 1330 scontext = NULL; 1331 scontext_len = 0; 1332 rc = 0; 1333 } else { 1334 rc = context_struct_to_string(policydb, context, scontext, 1335 scontext_len); 1336 } 1337 out_unlock: 1338 read_unlock(&state->ss->policy_rwlock); 1339 out: 1340 return rc; 1341 1342 } 1343 1344 /** 1345 * security_sid_to_context - Obtain a context for a given SID. 1346 * @sid: security identifier, SID 1347 * @scontext: security context 1348 * @scontext_len: length in bytes 1349 * 1350 * Write the string representation of the context associated with @sid 1351 * into a dynamically allocated string of the correct size. Set @scontext 1352 * to point to this string and set @scontext_len to the length of the string. 1353 */ 1354 int security_sid_to_context(struct selinux_state *state, 1355 u32 sid, char **scontext, u32 *scontext_len) 1356 { 1357 return security_sid_to_context_core(state, sid, scontext, 1358 scontext_len, 0, 0); 1359 } 1360 1361 int security_sid_to_context_force(struct selinux_state *state, u32 sid, 1362 char **scontext, u32 *scontext_len) 1363 { 1364 return security_sid_to_context_core(state, sid, scontext, 1365 scontext_len, 1, 0); 1366 } 1367 1368 /** 1369 * security_sid_to_context_inval - Obtain a context for a given SID if it 1370 * is invalid. 1371 * @sid: security identifier, SID 1372 * @scontext: security context 1373 * @scontext_len: length in bytes 1374 * 1375 * Write the string representation of the context associated with @sid 1376 * into a dynamically allocated string of the correct size, but only if the 1377 * context is invalid in the current policy. Set @scontext to point to 1378 * this string (or NULL if the context is valid) and set @scontext_len to 1379 * the length of the string (or 0 if the context is valid). 1380 */ 1381 int security_sid_to_context_inval(struct selinux_state *state, u32 sid, 1382 char **scontext, u32 *scontext_len) 1383 { 1384 return security_sid_to_context_core(state, sid, scontext, 1385 scontext_len, 1, 1); 1386 } 1387 1388 /* 1389 * Caveat: Mutates scontext. 1390 */ 1391 static int string_to_context_struct(struct policydb *pol, 1392 struct sidtab *sidtabp, 1393 char *scontext, 1394 struct context *ctx, 1395 u32 def_sid) 1396 { 1397 struct role_datum *role; 1398 struct type_datum *typdatum; 1399 struct user_datum *usrdatum; 1400 char *scontextp, *p, oldc; 1401 int rc = 0; 1402 1403 context_init(ctx); 1404 1405 /* Parse the security context. */ 1406 1407 rc = -EINVAL; 1408 scontextp = (char *) scontext; 1409 1410 /* Extract the user. */ 1411 p = scontextp; 1412 while (*p && *p != ':') 1413 p++; 1414 1415 if (*p == 0) 1416 goto out; 1417 1418 *p++ = 0; 1419 1420 usrdatum = hashtab_search(pol->p_users.table, scontextp); 1421 if (!usrdatum) 1422 goto out; 1423 1424 ctx->user = usrdatum->value; 1425 1426 /* Extract role. */ 1427 scontextp = p; 1428 while (*p && *p != ':') 1429 p++; 1430 1431 if (*p == 0) 1432 goto out; 1433 1434 *p++ = 0; 1435 1436 role = hashtab_search(pol->p_roles.table, scontextp); 1437 if (!role) 1438 goto out; 1439 ctx->role = role->value; 1440 1441 /* Extract type. */ 1442 scontextp = p; 1443 while (*p && *p != ':') 1444 p++; 1445 oldc = *p; 1446 *p++ = 0; 1447 1448 typdatum = hashtab_search(pol->p_types.table, scontextp); 1449 if (!typdatum || typdatum->attribute) 1450 goto out; 1451 1452 ctx->type = typdatum->value; 1453 1454 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1455 if (rc) 1456 goto out; 1457 1458 /* Check the validity of the new context. */ 1459 rc = -EINVAL; 1460 if (!policydb_context_isvalid(pol, ctx)) 1461 goto out; 1462 rc = 0; 1463 out: 1464 if (rc) 1465 context_destroy(ctx); 1466 return rc; 1467 } 1468 1469 static int security_context_to_sid_core(struct selinux_state *state, 1470 const char *scontext, u32 scontext_len, 1471 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1472 int force) 1473 { 1474 struct policydb *policydb; 1475 struct sidtab *sidtab; 1476 char *scontext2, *str = NULL; 1477 struct context context; 1478 int rc = 0; 1479 1480 /* An empty security context is never valid. */ 1481 if (!scontext_len) 1482 return -EINVAL; 1483 1484 /* Copy the string to allow changes and ensure a NUL terminator */ 1485 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1486 if (!scontext2) 1487 return -ENOMEM; 1488 1489 if (!state->initialized) { 1490 int i; 1491 1492 for (i = 1; i < SECINITSID_NUM; i++) { 1493 if (!strcmp(initial_sid_to_string[i], scontext2)) { 1494 *sid = i; 1495 goto out; 1496 } 1497 } 1498 *sid = SECINITSID_KERNEL; 1499 goto out; 1500 } 1501 *sid = SECSID_NULL; 1502 1503 if (force) { 1504 /* Save another copy for storing in uninterpreted form */ 1505 rc = -ENOMEM; 1506 str = kstrdup(scontext2, gfp_flags); 1507 if (!str) 1508 goto out; 1509 } 1510 read_lock(&state->ss->policy_rwlock); 1511 policydb = &state->ss->policydb; 1512 sidtab = state->ss->sidtab; 1513 rc = string_to_context_struct(policydb, sidtab, scontext2, 1514 &context, def_sid); 1515 if (rc == -EINVAL && force) { 1516 context.str = str; 1517 context.len = strlen(str) + 1; 1518 str = NULL; 1519 } else if (rc) 1520 goto out_unlock; 1521 rc = sidtab_context_to_sid(sidtab, &context, sid); 1522 context_destroy(&context); 1523 out_unlock: 1524 read_unlock(&state->ss->policy_rwlock); 1525 out: 1526 kfree(scontext2); 1527 kfree(str); 1528 return rc; 1529 } 1530 1531 /** 1532 * security_context_to_sid - Obtain a SID for a given security context. 1533 * @scontext: security context 1534 * @scontext_len: length in bytes 1535 * @sid: security identifier, SID 1536 * @gfp: context for the allocation 1537 * 1538 * Obtains a SID associated with the security context that 1539 * has the string representation specified by @scontext. 1540 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1541 * memory is available, or 0 on success. 1542 */ 1543 int security_context_to_sid(struct selinux_state *state, 1544 const char *scontext, u32 scontext_len, u32 *sid, 1545 gfp_t gfp) 1546 { 1547 return security_context_to_sid_core(state, scontext, scontext_len, 1548 sid, SECSID_NULL, gfp, 0); 1549 } 1550 1551 int security_context_str_to_sid(struct selinux_state *state, 1552 const char *scontext, u32 *sid, gfp_t gfp) 1553 { 1554 return security_context_to_sid(state, scontext, strlen(scontext), 1555 sid, gfp); 1556 } 1557 1558 /** 1559 * security_context_to_sid_default - Obtain a SID for a given security context, 1560 * falling back to specified default if needed. 1561 * 1562 * @scontext: security context 1563 * @scontext_len: length in bytes 1564 * @sid: security identifier, SID 1565 * @def_sid: default SID to assign on error 1566 * 1567 * Obtains a SID associated with the security context that 1568 * has the string representation specified by @scontext. 1569 * The default SID is passed to the MLS layer to be used to allow 1570 * kernel labeling of the MLS field if the MLS field is not present 1571 * (for upgrading to MLS without full relabel). 1572 * Implicitly forces adding of the context even if it cannot be mapped yet. 1573 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1574 * memory is available, or 0 on success. 1575 */ 1576 int security_context_to_sid_default(struct selinux_state *state, 1577 const char *scontext, u32 scontext_len, 1578 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1579 { 1580 return security_context_to_sid_core(state, scontext, scontext_len, 1581 sid, def_sid, gfp_flags, 1); 1582 } 1583 1584 int security_context_to_sid_force(struct selinux_state *state, 1585 const char *scontext, u32 scontext_len, 1586 u32 *sid) 1587 { 1588 return security_context_to_sid_core(state, scontext, scontext_len, 1589 sid, SECSID_NULL, GFP_KERNEL, 1); 1590 } 1591 1592 static int compute_sid_handle_invalid_context( 1593 struct selinux_state *state, 1594 struct context *scontext, 1595 struct context *tcontext, 1596 u16 tclass, 1597 struct context *newcontext) 1598 { 1599 struct policydb *policydb = &state->ss->policydb; 1600 char *s = NULL, *t = NULL, *n = NULL; 1601 u32 slen, tlen, nlen; 1602 1603 if (context_struct_to_string(policydb, scontext, &s, &slen)) 1604 goto out; 1605 if (context_struct_to_string(policydb, tcontext, &t, &tlen)) 1606 goto out; 1607 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1608 goto out; 1609 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 1610 "op=security_compute_sid invalid_context=%s" 1611 " scontext=%s" 1612 " tcontext=%s" 1613 " tclass=%s", 1614 n, s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1615 out: 1616 kfree(s); 1617 kfree(t); 1618 kfree(n); 1619 if (!enforcing_enabled(state)) 1620 return 0; 1621 return -EACCES; 1622 } 1623 1624 static void filename_compute_type(struct policydb *policydb, 1625 struct context *newcontext, 1626 u32 stype, u32 ttype, u16 tclass, 1627 const char *objname) 1628 { 1629 struct filename_trans ft; 1630 struct filename_trans_datum *otype; 1631 1632 /* 1633 * Most filename trans rules are going to live in specific directories 1634 * like /dev or /var/run. This bitmap will quickly skip rule searches 1635 * if the ttype does not contain any rules. 1636 */ 1637 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1638 return; 1639 1640 ft.stype = stype; 1641 ft.ttype = ttype; 1642 ft.tclass = tclass; 1643 ft.name = objname; 1644 1645 otype = hashtab_search(policydb->filename_trans, &ft); 1646 if (otype) 1647 newcontext->type = otype->otype; 1648 } 1649 1650 static int security_compute_sid(struct selinux_state *state, 1651 u32 ssid, 1652 u32 tsid, 1653 u16 orig_tclass, 1654 u32 specified, 1655 const char *objname, 1656 u32 *out_sid, 1657 bool kern) 1658 { 1659 struct policydb *policydb; 1660 struct sidtab *sidtab; 1661 struct class_datum *cladatum = NULL; 1662 struct context *scontext = NULL, *tcontext = NULL, newcontext; 1663 struct role_trans *roletr = NULL; 1664 struct avtab_key avkey; 1665 struct avtab_datum *avdatum; 1666 struct avtab_node *node; 1667 u16 tclass; 1668 int rc = 0; 1669 bool sock; 1670 1671 if (!state->initialized) { 1672 switch (orig_tclass) { 1673 case SECCLASS_PROCESS: /* kernel value */ 1674 *out_sid = ssid; 1675 break; 1676 default: 1677 *out_sid = tsid; 1678 break; 1679 } 1680 goto out; 1681 } 1682 1683 context_init(&newcontext); 1684 1685 read_lock(&state->ss->policy_rwlock); 1686 1687 if (kern) { 1688 tclass = unmap_class(&state->ss->map, orig_tclass); 1689 sock = security_is_socket_class(orig_tclass); 1690 } else { 1691 tclass = orig_tclass; 1692 sock = security_is_socket_class(map_class(&state->ss->map, 1693 tclass)); 1694 } 1695 1696 policydb = &state->ss->policydb; 1697 sidtab = state->ss->sidtab; 1698 1699 scontext = sidtab_search(sidtab, ssid); 1700 if (!scontext) { 1701 pr_err("SELinux: %s: unrecognized SID %d\n", 1702 __func__, ssid); 1703 rc = -EINVAL; 1704 goto out_unlock; 1705 } 1706 tcontext = sidtab_search(sidtab, tsid); 1707 if (!tcontext) { 1708 pr_err("SELinux: %s: unrecognized SID %d\n", 1709 __func__, tsid); 1710 rc = -EINVAL; 1711 goto out_unlock; 1712 } 1713 1714 if (tclass && tclass <= policydb->p_classes.nprim) 1715 cladatum = policydb->class_val_to_struct[tclass - 1]; 1716 1717 /* Set the user identity. */ 1718 switch (specified) { 1719 case AVTAB_TRANSITION: 1720 case AVTAB_CHANGE: 1721 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1722 newcontext.user = tcontext->user; 1723 } else { 1724 /* notice this gets both DEFAULT_SOURCE and unset */ 1725 /* Use the process user identity. */ 1726 newcontext.user = scontext->user; 1727 } 1728 break; 1729 case AVTAB_MEMBER: 1730 /* Use the related object owner. */ 1731 newcontext.user = tcontext->user; 1732 break; 1733 } 1734 1735 /* Set the role to default values. */ 1736 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1737 newcontext.role = scontext->role; 1738 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1739 newcontext.role = tcontext->role; 1740 } else { 1741 if ((tclass == policydb->process_class) || (sock == true)) 1742 newcontext.role = scontext->role; 1743 else 1744 newcontext.role = OBJECT_R_VAL; 1745 } 1746 1747 /* Set the type to default values. */ 1748 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1749 newcontext.type = scontext->type; 1750 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1751 newcontext.type = tcontext->type; 1752 } else { 1753 if ((tclass == policydb->process_class) || (sock == true)) { 1754 /* Use the type of process. */ 1755 newcontext.type = scontext->type; 1756 } else { 1757 /* Use the type of the related object. */ 1758 newcontext.type = tcontext->type; 1759 } 1760 } 1761 1762 /* Look for a type transition/member/change rule. */ 1763 avkey.source_type = scontext->type; 1764 avkey.target_type = tcontext->type; 1765 avkey.target_class = tclass; 1766 avkey.specified = specified; 1767 avdatum = avtab_search(&policydb->te_avtab, &avkey); 1768 1769 /* If no permanent rule, also check for enabled conditional rules */ 1770 if (!avdatum) { 1771 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1772 for (; node; node = avtab_search_node_next(node, specified)) { 1773 if (node->key.specified & AVTAB_ENABLED) { 1774 avdatum = &node->datum; 1775 break; 1776 } 1777 } 1778 } 1779 1780 if (avdatum) { 1781 /* Use the type from the type transition/member/change rule. */ 1782 newcontext.type = avdatum->u.data; 1783 } 1784 1785 /* if we have a objname this is a file trans check so check those rules */ 1786 if (objname) 1787 filename_compute_type(policydb, &newcontext, scontext->type, 1788 tcontext->type, tclass, objname); 1789 1790 /* Check for class-specific changes. */ 1791 if (specified & AVTAB_TRANSITION) { 1792 /* Look for a role transition rule. */ 1793 for (roletr = policydb->role_tr; roletr; 1794 roletr = roletr->next) { 1795 if ((roletr->role == scontext->role) && 1796 (roletr->type == tcontext->type) && 1797 (roletr->tclass == tclass)) { 1798 /* Use the role transition rule. */ 1799 newcontext.role = roletr->new_role; 1800 break; 1801 } 1802 } 1803 } 1804 1805 /* Set the MLS attributes. 1806 This is done last because it may allocate memory. */ 1807 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1808 &newcontext, sock); 1809 if (rc) 1810 goto out_unlock; 1811 1812 /* Check the validity of the context. */ 1813 if (!policydb_context_isvalid(policydb, &newcontext)) { 1814 rc = compute_sid_handle_invalid_context(state, scontext, 1815 tcontext, 1816 tclass, 1817 &newcontext); 1818 if (rc) 1819 goto out_unlock; 1820 } 1821 /* Obtain the sid for the context. */ 1822 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1823 out_unlock: 1824 read_unlock(&state->ss->policy_rwlock); 1825 context_destroy(&newcontext); 1826 out: 1827 return rc; 1828 } 1829 1830 /** 1831 * security_transition_sid - Compute the SID for a new subject/object. 1832 * @ssid: source security identifier 1833 * @tsid: target security identifier 1834 * @tclass: target security class 1835 * @out_sid: security identifier for new subject/object 1836 * 1837 * Compute a SID to use for labeling a new subject or object in the 1838 * class @tclass based on a SID pair (@ssid, @tsid). 1839 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1840 * if insufficient memory is available, or %0 if the new SID was 1841 * computed successfully. 1842 */ 1843 int security_transition_sid(struct selinux_state *state, 1844 u32 ssid, u32 tsid, u16 tclass, 1845 const struct qstr *qstr, u32 *out_sid) 1846 { 1847 return security_compute_sid(state, ssid, tsid, tclass, 1848 AVTAB_TRANSITION, 1849 qstr ? qstr->name : NULL, out_sid, true); 1850 } 1851 1852 int security_transition_sid_user(struct selinux_state *state, 1853 u32 ssid, u32 tsid, u16 tclass, 1854 const char *objname, u32 *out_sid) 1855 { 1856 return security_compute_sid(state, ssid, tsid, tclass, 1857 AVTAB_TRANSITION, 1858 objname, out_sid, false); 1859 } 1860 1861 /** 1862 * security_member_sid - Compute the SID for member selection. 1863 * @ssid: source security identifier 1864 * @tsid: target security identifier 1865 * @tclass: target security class 1866 * @out_sid: security identifier for selected member 1867 * 1868 * Compute a SID to use when selecting a member of a polyinstantiated 1869 * object of class @tclass based on a SID pair (@ssid, @tsid). 1870 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1871 * if insufficient memory is available, or %0 if the SID was 1872 * computed successfully. 1873 */ 1874 int security_member_sid(struct selinux_state *state, 1875 u32 ssid, 1876 u32 tsid, 1877 u16 tclass, 1878 u32 *out_sid) 1879 { 1880 return security_compute_sid(state, ssid, tsid, tclass, 1881 AVTAB_MEMBER, NULL, 1882 out_sid, false); 1883 } 1884 1885 /** 1886 * security_change_sid - Compute the SID for object relabeling. 1887 * @ssid: source security identifier 1888 * @tsid: target security identifier 1889 * @tclass: target security class 1890 * @out_sid: security identifier for selected member 1891 * 1892 * Compute a SID to use for relabeling an object of class @tclass 1893 * based on a SID pair (@ssid, @tsid). 1894 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1895 * if insufficient memory is available, or %0 if the SID was 1896 * computed successfully. 1897 */ 1898 int security_change_sid(struct selinux_state *state, 1899 u32 ssid, 1900 u32 tsid, 1901 u16 tclass, 1902 u32 *out_sid) 1903 { 1904 return security_compute_sid(state, 1905 ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1906 out_sid, false); 1907 } 1908 1909 static inline int convert_context_handle_invalid_context( 1910 struct selinux_state *state, 1911 struct context *context) 1912 { 1913 struct policydb *policydb = &state->ss->policydb; 1914 char *s; 1915 u32 len; 1916 1917 if (enforcing_enabled(state)) 1918 return -EINVAL; 1919 1920 if (!context_struct_to_string(policydb, context, &s, &len)) { 1921 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 1922 s); 1923 kfree(s); 1924 } 1925 return 0; 1926 } 1927 1928 struct convert_context_args { 1929 struct selinux_state *state; 1930 struct policydb *oldp; 1931 struct policydb *newp; 1932 }; 1933 1934 /* 1935 * Convert the values in the security context 1936 * structure `oldc' from the values specified 1937 * in the policy `p->oldp' to the values specified 1938 * in the policy `p->newp', storing the new context 1939 * in `newc'. Verify that the context is valid 1940 * under the new policy. 1941 */ 1942 static int convert_context(struct context *oldc, struct context *newc, void *p) 1943 { 1944 struct convert_context_args *args; 1945 struct ocontext *oc; 1946 struct role_datum *role; 1947 struct type_datum *typdatum; 1948 struct user_datum *usrdatum; 1949 char *s; 1950 u32 len; 1951 int rc; 1952 1953 args = p; 1954 1955 if (oldc->str) { 1956 s = kstrdup(oldc->str, GFP_KERNEL); 1957 if (!s) 1958 return -ENOMEM; 1959 1960 rc = string_to_context_struct(args->newp, NULL, s, 1961 newc, SECSID_NULL); 1962 if (rc == -EINVAL) { 1963 /* Retain string representation for later mapping. */ 1964 context_init(newc); 1965 newc->str = s; 1966 newc->len = oldc->len; 1967 return 0; 1968 } 1969 kfree(s); 1970 if (rc) { 1971 /* Other error condition, e.g. ENOMEM. */ 1972 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 1973 oldc->str, -rc); 1974 return rc; 1975 } 1976 pr_info("SELinux: Context %s became valid (mapped).\n", 1977 oldc->str); 1978 return 0; 1979 } 1980 1981 context_init(newc); 1982 1983 /* Convert the user. */ 1984 rc = -EINVAL; 1985 usrdatum = hashtab_search(args->newp->p_users.table, 1986 sym_name(args->oldp, 1987 SYM_USERS, oldc->user - 1)); 1988 if (!usrdatum) 1989 goto bad; 1990 newc->user = usrdatum->value; 1991 1992 /* Convert the role. */ 1993 rc = -EINVAL; 1994 role = hashtab_search(args->newp->p_roles.table, 1995 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 1996 if (!role) 1997 goto bad; 1998 newc->role = role->value; 1999 2000 /* Convert the type. */ 2001 rc = -EINVAL; 2002 typdatum = hashtab_search(args->newp->p_types.table, 2003 sym_name(args->oldp, 2004 SYM_TYPES, oldc->type - 1)); 2005 if (!typdatum) 2006 goto bad; 2007 newc->type = typdatum->value; 2008 2009 /* Convert the MLS fields if dealing with MLS policies */ 2010 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2011 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2012 if (rc) 2013 goto bad; 2014 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2015 /* 2016 * Switching between non-MLS and MLS policy: 2017 * ensure that the MLS fields of the context for all 2018 * existing entries in the sidtab are filled in with a 2019 * suitable default value, likely taken from one of the 2020 * initial SIDs. 2021 */ 2022 oc = args->newp->ocontexts[OCON_ISID]; 2023 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2024 oc = oc->next; 2025 rc = -EINVAL; 2026 if (!oc) { 2027 pr_err("SELinux: unable to look up" 2028 " the initial SIDs list\n"); 2029 goto bad; 2030 } 2031 rc = mls_range_set(newc, &oc->context[0].range); 2032 if (rc) 2033 goto bad; 2034 } 2035 2036 /* Check the validity of the new context. */ 2037 if (!policydb_context_isvalid(args->newp, newc)) { 2038 rc = convert_context_handle_invalid_context(args->state, oldc); 2039 if (rc) 2040 goto bad; 2041 } 2042 2043 return 0; 2044 bad: 2045 /* Map old representation to string and save it. */ 2046 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2047 if (rc) 2048 return rc; 2049 context_destroy(newc); 2050 newc->str = s; 2051 newc->len = len; 2052 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2053 newc->str); 2054 return 0; 2055 } 2056 2057 static void security_load_policycaps(struct selinux_state *state) 2058 { 2059 struct policydb *p = &state->ss->policydb; 2060 unsigned int i; 2061 struct ebitmap_node *node; 2062 2063 for (i = 0; i < ARRAY_SIZE(state->policycap); i++) 2064 state->policycap[i] = ebitmap_get_bit(&p->policycaps, i); 2065 2066 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2067 pr_info("SELinux: policy capability %s=%d\n", 2068 selinux_policycap_names[i], 2069 ebitmap_get_bit(&p->policycaps, i)); 2070 2071 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2072 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2073 pr_info("SELinux: unknown policy capability %u\n", 2074 i); 2075 } 2076 } 2077 2078 static int security_preserve_bools(struct selinux_state *state, 2079 struct policydb *newpolicydb); 2080 2081 /** 2082 * security_load_policy - Load a security policy configuration. 2083 * @data: binary policy data 2084 * @len: length of data in bytes 2085 * 2086 * Load a new set of security policy configuration data, 2087 * validate it and convert the SID table as necessary. 2088 * This function will flush the access vector cache after 2089 * loading the new policy. 2090 */ 2091 int security_load_policy(struct selinux_state *state, void *data, size_t len) 2092 { 2093 struct policydb *policydb; 2094 struct sidtab *oldsidtab, *newsidtab; 2095 struct policydb *oldpolicydb, *newpolicydb; 2096 struct selinux_mapping *oldmapping; 2097 struct selinux_map newmap; 2098 struct sidtab_convert_params convert_params; 2099 struct convert_context_args args; 2100 u32 seqno; 2101 int rc = 0; 2102 struct policy_file file = { data, len }, *fp = &file; 2103 2104 oldpolicydb = kcalloc(2, sizeof(*oldpolicydb), GFP_KERNEL); 2105 if (!oldpolicydb) { 2106 rc = -ENOMEM; 2107 goto out; 2108 } 2109 newpolicydb = oldpolicydb + 1; 2110 2111 policydb = &state->ss->policydb; 2112 2113 newsidtab = kmalloc(sizeof(*newsidtab), GFP_KERNEL); 2114 if (!newsidtab) { 2115 rc = -ENOMEM; 2116 goto out; 2117 } 2118 2119 if (!state->initialized) { 2120 rc = policydb_read(policydb, fp); 2121 if (rc) { 2122 kfree(newsidtab); 2123 goto out; 2124 } 2125 2126 policydb->len = len; 2127 rc = selinux_set_mapping(policydb, secclass_map, 2128 &state->ss->map); 2129 if (rc) { 2130 kfree(newsidtab); 2131 policydb_destroy(policydb); 2132 goto out; 2133 } 2134 2135 rc = policydb_load_isids(policydb, newsidtab); 2136 if (rc) { 2137 kfree(newsidtab); 2138 policydb_destroy(policydb); 2139 goto out; 2140 } 2141 2142 state->ss->sidtab = newsidtab; 2143 security_load_policycaps(state); 2144 state->initialized = 1; 2145 seqno = ++state->ss->latest_granting; 2146 selinux_complete_init(); 2147 avc_ss_reset(state->avc, seqno); 2148 selnl_notify_policyload(seqno); 2149 selinux_status_update_policyload(state, seqno); 2150 selinux_netlbl_cache_invalidate(); 2151 selinux_xfrm_notify_policyload(); 2152 goto out; 2153 } 2154 2155 rc = policydb_read(newpolicydb, fp); 2156 if (rc) { 2157 kfree(newsidtab); 2158 goto out; 2159 } 2160 2161 newpolicydb->len = len; 2162 /* If switching between different policy types, log MLS status */ 2163 if (policydb->mls_enabled && !newpolicydb->mls_enabled) 2164 pr_info("SELinux: Disabling MLS support...\n"); 2165 else if (!policydb->mls_enabled && newpolicydb->mls_enabled) 2166 pr_info("SELinux: Enabling MLS support...\n"); 2167 2168 rc = policydb_load_isids(newpolicydb, newsidtab); 2169 if (rc) { 2170 pr_err("SELinux: unable to load the initial SIDs\n"); 2171 policydb_destroy(newpolicydb); 2172 kfree(newsidtab); 2173 goto out; 2174 } 2175 2176 rc = selinux_set_mapping(newpolicydb, secclass_map, &newmap); 2177 if (rc) 2178 goto err; 2179 2180 rc = security_preserve_bools(state, newpolicydb); 2181 if (rc) { 2182 pr_err("SELinux: unable to preserve booleans\n"); 2183 goto err; 2184 } 2185 2186 oldsidtab = state->ss->sidtab; 2187 2188 /* 2189 * Convert the internal representations of contexts 2190 * in the new SID table. 2191 */ 2192 args.state = state; 2193 args.oldp = policydb; 2194 args.newp = newpolicydb; 2195 2196 convert_params.func = convert_context; 2197 convert_params.args = &args; 2198 convert_params.target = newsidtab; 2199 2200 rc = sidtab_convert(oldsidtab, &convert_params); 2201 if (rc) { 2202 pr_err("SELinux: unable to convert the internal" 2203 " representation of contexts in the new SID" 2204 " table\n"); 2205 goto err; 2206 } 2207 2208 /* Save the old policydb and SID table to free later. */ 2209 memcpy(oldpolicydb, policydb, sizeof(*policydb)); 2210 2211 /* Install the new policydb and SID table. */ 2212 write_lock_irq(&state->ss->policy_rwlock); 2213 memcpy(policydb, newpolicydb, sizeof(*policydb)); 2214 state->ss->sidtab = newsidtab; 2215 security_load_policycaps(state); 2216 oldmapping = state->ss->map.mapping; 2217 state->ss->map.mapping = newmap.mapping; 2218 state->ss->map.size = newmap.size; 2219 seqno = ++state->ss->latest_granting; 2220 write_unlock_irq(&state->ss->policy_rwlock); 2221 2222 /* Free the old policydb and SID table. */ 2223 policydb_destroy(oldpolicydb); 2224 sidtab_destroy(oldsidtab); 2225 kfree(oldsidtab); 2226 kfree(oldmapping); 2227 2228 avc_ss_reset(state->avc, seqno); 2229 selnl_notify_policyload(seqno); 2230 selinux_status_update_policyload(state, seqno); 2231 selinux_netlbl_cache_invalidate(); 2232 selinux_xfrm_notify_policyload(); 2233 2234 rc = 0; 2235 goto out; 2236 2237 err: 2238 kfree(newmap.mapping); 2239 sidtab_destroy(newsidtab); 2240 kfree(newsidtab); 2241 policydb_destroy(newpolicydb); 2242 2243 out: 2244 kfree(oldpolicydb); 2245 return rc; 2246 } 2247 2248 size_t security_policydb_len(struct selinux_state *state) 2249 { 2250 struct policydb *p = &state->ss->policydb; 2251 size_t len; 2252 2253 read_lock(&state->ss->policy_rwlock); 2254 len = p->len; 2255 read_unlock(&state->ss->policy_rwlock); 2256 2257 return len; 2258 } 2259 2260 /** 2261 * security_port_sid - Obtain the SID for a port. 2262 * @protocol: protocol number 2263 * @port: port number 2264 * @out_sid: security identifier 2265 */ 2266 int security_port_sid(struct selinux_state *state, 2267 u8 protocol, u16 port, u32 *out_sid) 2268 { 2269 struct policydb *policydb; 2270 struct sidtab *sidtab; 2271 struct ocontext *c; 2272 int rc = 0; 2273 2274 read_lock(&state->ss->policy_rwlock); 2275 2276 policydb = &state->ss->policydb; 2277 sidtab = state->ss->sidtab; 2278 2279 c = policydb->ocontexts[OCON_PORT]; 2280 while (c) { 2281 if (c->u.port.protocol == protocol && 2282 c->u.port.low_port <= port && 2283 c->u.port.high_port >= port) 2284 break; 2285 c = c->next; 2286 } 2287 2288 if (c) { 2289 if (!c->sid[0]) { 2290 rc = sidtab_context_to_sid(sidtab, 2291 &c->context[0], 2292 &c->sid[0]); 2293 if (rc) 2294 goto out; 2295 } 2296 *out_sid = c->sid[0]; 2297 } else { 2298 *out_sid = SECINITSID_PORT; 2299 } 2300 2301 out: 2302 read_unlock(&state->ss->policy_rwlock); 2303 return rc; 2304 } 2305 2306 /** 2307 * security_pkey_sid - Obtain the SID for a pkey. 2308 * @subnet_prefix: Subnet Prefix 2309 * @pkey_num: pkey number 2310 * @out_sid: security identifier 2311 */ 2312 int security_ib_pkey_sid(struct selinux_state *state, 2313 u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2314 { 2315 struct policydb *policydb; 2316 struct sidtab *sidtab; 2317 struct ocontext *c; 2318 int rc = 0; 2319 2320 read_lock(&state->ss->policy_rwlock); 2321 2322 policydb = &state->ss->policydb; 2323 sidtab = state->ss->sidtab; 2324 2325 c = policydb->ocontexts[OCON_IBPKEY]; 2326 while (c) { 2327 if (c->u.ibpkey.low_pkey <= pkey_num && 2328 c->u.ibpkey.high_pkey >= pkey_num && 2329 c->u.ibpkey.subnet_prefix == subnet_prefix) 2330 break; 2331 2332 c = c->next; 2333 } 2334 2335 if (c) { 2336 if (!c->sid[0]) { 2337 rc = sidtab_context_to_sid(sidtab, 2338 &c->context[0], 2339 &c->sid[0]); 2340 if (rc) 2341 goto out; 2342 } 2343 *out_sid = c->sid[0]; 2344 } else 2345 *out_sid = SECINITSID_UNLABELED; 2346 2347 out: 2348 read_unlock(&state->ss->policy_rwlock); 2349 return rc; 2350 } 2351 2352 /** 2353 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2354 * @dev_name: device name 2355 * @port: port number 2356 * @out_sid: security identifier 2357 */ 2358 int security_ib_endport_sid(struct selinux_state *state, 2359 const char *dev_name, u8 port_num, u32 *out_sid) 2360 { 2361 struct policydb *policydb; 2362 struct sidtab *sidtab; 2363 struct ocontext *c; 2364 int rc = 0; 2365 2366 read_lock(&state->ss->policy_rwlock); 2367 2368 policydb = &state->ss->policydb; 2369 sidtab = state->ss->sidtab; 2370 2371 c = policydb->ocontexts[OCON_IBENDPORT]; 2372 while (c) { 2373 if (c->u.ibendport.port == port_num && 2374 !strncmp(c->u.ibendport.dev_name, 2375 dev_name, 2376 IB_DEVICE_NAME_MAX)) 2377 break; 2378 2379 c = c->next; 2380 } 2381 2382 if (c) { 2383 if (!c->sid[0]) { 2384 rc = sidtab_context_to_sid(sidtab, 2385 &c->context[0], 2386 &c->sid[0]); 2387 if (rc) 2388 goto out; 2389 } 2390 *out_sid = c->sid[0]; 2391 } else 2392 *out_sid = SECINITSID_UNLABELED; 2393 2394 out: 2395 read_unlock(&state->ss->policy_rwlock); 2396 return rc; 2397 } 2398 2399 /** 2400 * security_netif_sid - Obtain the SID for a network interface. 2401 * @name: interface name 2402 * @if_sid: interface SID 2403 */ 2404 int security_netif_sid(struct selinux_state *state, 2405 char *name, u32 *if_sid) 2406 { 2407 struct policydb *policydb; 2408 struct sidtab *sidtab; 2409 int rc = 0; 2410 struct ocontext *c; 2411 2412 read_lock(&state->ss->policy_rwlock); 2413 2414 policydb = &state->ss->policydb; 2415 sidtab = state->ss->sidtab; 2416 2417 c = policydb->ocontexts[OCON_NETIF]; 2418 while (c) { 2419 if (strcmp(name, c->u.name) == 0) 2420 break; 2421 c = c->next; 2422 } 2423 2424 if (c) { 2425 if (!c->sid[0] || !c->sid[1]) { 2426 rc = sidtab_context_to_sid(sidtab, 2427 &c->context[0], 2428 &c->sid[0]); 2429 if (rc) 2430 goto out; 2431 rc = sidtab_context_to_sid(sidtab, 2432 &c->context[1], 2433 &c->sid[1]); 2434 if (rc) 2435 goto out; 2436 } 2437 *if_sid = c->sid[0]; 2438 } else 2439 *if_sid = SECINITSID_NETIF; 2440 2441 out: 2442 read_unlock(&state->ss->policy_rwlock); 2443 return rc; 2444 } 2445 2446 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2447 { 2448 int i, fail = 0; 2449 2450 for (i = 0; i < 4; i++) 2451 if (addr[i] != (input[i] & mask[i])) { 2452 fail = 1; 2453 break; 2454 } 2455 2456 return !fail; 2457 } 2458 2459 /** 2460 * security_node_sid - Obtain the SID for a node (host). 2461 * @domain: communication domain aka address family 2462 * @addrp: address 2463 * @addrlen: address length in bytes 2464 * @out_sid: security identifier 2465 */ 2466 int security_node_sid(struct selinux_state *state, 2467 u16 domain, 2468 void *addrp, 2469 u32 addrlen, 2470 u32 *out_sid) 2471 { 2472 struct policydb *policydb; 2473 struct sidtab *sidtab; 2474 int rc; 2475 struct ocontext *c; 2476 2477 read_lock(&state->ss->policy_rwlock); 2478 2479 policydb = &state->ss->policydb; 2480 sidtab = state->ss->sidtab; 2481 2482 switch (domain) { 2483 case AF_INET: { 2484 u32 addr; 2485 2486 rc = -EINVAL; 2487 if (addrlen != sizeof(u32)) 2488 goto out; 2489 2490 addr = *((u32 *)addrp); 2491 2492 c = policydb->ocontexts[OCON_NODE]; 2493 while (c) { 2494 if (c->u.node.addr == (addr & c->u.node.mask)) 2495 break; 2496 c = c->next; 2497 } 2498 break; 2499 } 2500 2501 case AF_INET6: 2502 rc = -EINVAL; 2503 if (addrlen != sizeof(u64) * 2) 2504 goto out; 2505 c = policydb->ocontexts[OCON_NODE6]; 2506 while (c) { 2507 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2508 c->u.node6.mask)) 2509 break; 2510 c = c->next; 2511 } 2512 break; 2513 2514 default: 2515 rc = 0; 2516 *out_sid = SECINITSID_NODE; 2517 goto out; 2518 } 2519 2520 if (c) { 2521 if (!c->sid[0]) { 2522 rc = sidtab_context_to_sid(sidtab, 2523 &c->context[0], 2524 &c->sid[0]); 2525 if (rc) 2526 goto out; 2527 } 2528 *out_sid = c->sid[0]; 2529 } else { 2530 *out_sid = SECINITSID_NODE; 2531 } 2532 2533 rc = 0; 2534 out: 2535 read_unlock(&state->ss->policy_rwlock); 2536 return rc; 2537 } 2538 2539 #define SIDS_NEL 25 2540 2541 /** 2542 * security_get_user_sids - Obtain reachable SIDs for a user. 2543 * @fromsid: starting SID 2544 * @username: username 2545 * @sids: array of reachable SIDs for user 2546 * @nel: number of elements in @sids 2547 * 2548 * Generate the set of SIDs for legal security contexts 2549 * for a given user that can be reached by @fromsid. 2550 * Set *@sids to point to a dynamically allocated 2551 * array containing the set of SIDs. Set *@nel to the 2552 * number of elements in the array. 2553 */ 2554 2555 int security_get_user_sids(struct selinux_state *state, 2556 u32 fromsid, 2557 char *username, 2558 u32 **sids, 2559 u32 *nel) 2560 { 2561 struct policydb *policydb; 2562 struct sidtab *sidtab; 2563 struct context *fromcon, usercon; 2564 u32 *mysids = NULL, *mysids2, sid; 2565 u32 mynel = 0, maxnel = SIDS_NEL; 2566 struct user_datum *user; 2567 struct role_datum *role; 2568 struct ebitmap_node *rnode, *tnode; 2569 int rc = 0, i, j; 2570 2571 *sids = NULL; 2572 *nel = 0; 2573 2574 if (!state->initialized) 2575 goto out; 2576 2577 read_lock(&state->ss->policy_rwlock); 2578 2579 policydb = &state->ss->policydb; 2580 sidtab = state->ss->sidtab; 2581 2582 context_init(&usercon); 2583 2584 rc = -EINVAL; 2585 fromcon = sidtab_search(sidtab, fromsid); 2586 if (!fromcon) 2587 goto out_unlock; 2588 2589 rc = -EINVAL; 2590 user = hashtab_search(policydb->p_users.table, username); 2591 if (!user) 2592 goto out_unlock; 2593 2594 usercon.user = user->value; 2595 2596 rc = -ENOMEM; 2597 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); 2598 if (!mysids) 2599 goto out_unlock; 2600 2601 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2602 role = policydb->role_val_to_struct[i]; 2603 usercon.role = i + 1; 2604 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2605 usercon.type = j + 1; 2606 2607 if (mls_setup_user_range(policydb, fromcon, user, 2608 &usercon)) 2609 continue; 2610 2611 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2612 if (rc) 2613 goto out_unlock; 2614 if (mynel < maxnel) { 2615 mysids[mynel++] = sid; 2616 } else { 2617 rc = -ENOMEM; 2618 maxnel += SIDS_NEL; 2619 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2620 if (!mysids2) 2621 goto out_unlock; 2622 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2623 kfree(mysids); 2624 mysids = mysids2; 2625 mysids[mynel++] = sid; 2626 } 2627 } 2628 } 2629 rc = 0; 2630 out_unlock: 2631 read_unlock(&state->ss->policy_rwlock); 2632 if (rc || !mynel) { 2633 kfree(mysids); 2634 goto out; 2635 } 2636 2637 rc = -ENOMEM; 2638 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2639 if (!mysids2) { 2640 kfree(mysids); 2641 goto out; 2642 } 2643 for (i = 0, j = 0; i < mynel; i++) { 2644 struct av_decision dummy_avd; 2645 rc = avc_has_perm_noaudit(state, 2646 fromsid, mysids[i], 2647 SECCLASS_PROCESS, /* kernel value */ 2648 PROCESS__TRANSITION, AVC_STRICT, 2649 &dummy_avd); 2650 if (!rc) 2651 mysids2[j++] = mysids[i]; 2652 cond_resched(); 2653 } 2654 rc = 0; 2655 kfree(mysids); 2656 *sids = mysids2; 2657 *nel = j; 2658 out: 2659 return rc; 2660 } 2661 2662 /** 2663 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2664 * @fstype: filesystem type 2665 * @path: path from root of mount 2666 * @sclass: file security class 2667 * @sid: SID for path 2668 * 2669 * Obtain a SID to use for a file in a filesystem that 2670 * cannot support xattr or use a fixed labeling behavior like 2671 * transition SIDs or task SIDs. 2672 * 2673 * The caller must acquire the policy_rwlock before calling this function. 2674 */ 2675 static inline int __security_genfs_sid(struct selinux_state *state, 2676 const char *fstype, 2677 char *path, 2678 u16 orig_sclass, 2679 u32 *sid) 2680 { 2681 struct policydb *policydb = &state->ss->policydb; 2682 struct sidtab *sidtab = state->ss->sidtab; 2683 int len; 2684 u16 sclass; 2685 struct genfs *genfs; 2686 struct ocontext *c; 2687 int rc, cmp = 0; 2688 2689 while (path[0] == '/' && path[1] == '/') 2690 path++; 2691 2692 sclass = unmap_class(&state->ss->map, orig_sclass); 2693 *sid = SECINITSID_UNLABELED; 2694 2695 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2696 cmp = strcmp(fstype, genfs->fstype); 2697 if (cmp <= 0) 2698 break; 2699 } 2700 2701 rc = -ENOENT; 2702 if (!genfs || cmp) 2703 goto out; 2704 2705 for (c = genfs->head; c; c = c->next) { 2706 len = strlen(c->u.name); 2707 if ((!c->v.sclass || sclass == c->v.sclass) && 2708 (strncmp(c->u.name, path, len) == 0)) 2709 break; 2710 } 2711 2712 rc = -ENOENT; 2713 if (!c) 2714 goto out; 2715 2716 if (!c->sid[0]) { 2717 rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]); 2718 if (rc) 2719 goto out; 2720 } 2721 2722 *sid = c->sid[0]; 2723 rc = 0; 2724 out: 2725 return rc; 2726 } 2727 2728 /** 2729 * security_genfs_sid - Obtain a SID for a file in a filesystem 2730 * @fstype: filesystem type 2731 * @path: path from root of mount 2732 * @sclass: file security class 2733 * @sid: SID for path 2734 * 2735 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2736 * it afterward. 2737 */ 2738 int security_genfs_sid(struct selinux_state *state, 2739 const char *fstype, 2740 char *path, 2741 u16 orig_sclass, 2742 u32 *sid) 2743 { 2744 int retval; 2745 2746 read_lock(&state->ss->policy_rwlock); 2747 retval = __security_genfs_sid(state, fstype, path, orig_sclass, sid); 2748 read_unlock(&state->ss->policy_rwlock); 2749 return retval; 2750 } 2751 2752 /** 2753 * security_fs_use - Determine how to handle labeling for a filesystem. 2754 * @sb: superblock in question 2755 */ 2756 int security_fs_use(struct selinux_state *state, struct super_block *sb) 2757 { 2758 struct policydb *policydb; 2759 struct sidtab *sidtab; 2760 int rc = 0; 2761 struct ocontext *c; 2762 struct superblock_security_struct *sbsec = sb->s_security; 2763 const char *fstype = sb->s_type->name; 2764 2765 read_lock(&state->ss->policy_rwlock); 2766 2767 policydb = &state->ss->policydb; 2768 sidtab = state->ss->sidtab; 2769 2770 c = policydb->ocontexts[OCON_FSUSE]; 2771 while (c) { 2772 if (strcmp(fstype, c->u.name) == 0) 2773 break; 2774 c = c->next; 2775 } 2776 2777 if (c) { 2778 sbsec->behavior = c->v.behavior; 2779 if (!c->sid[0]) { 2780 rc = sidtab_context_to_sid(sidtab, &c->context[0], 2781 &c->sid[0]); 2782 if (rc) 2783 goto out; 2784 } 2785 sbsec->sid = c->sid[0]; 2786 } else { 2787 rc = __security_genfs_sid(state, fstype, "/", SECCLASS_DIR, 2788 &sbsec->sid); 2789 if (rc) { 2790 sbsec->behavior = SECURITY_FS_USE_NONE; 2791 rc = 0; 2792 } else { 2793 sbsec->behavior = SECURITY_FS_USE_GENFS; 2794 } 2795 } 2796 2797 out: 2798 read_unlock(&state->ss->policy_rwlock); 2799 return rc; 2800 } 2801 2802 int security_get_bools(struct selinux_state *state, 2803 int *len, char ***names, int **values) 2804 { 2805 struct policydb *policydb; 2806 int i, rc; 2807 2808 if (!state->initialized) { 2809 *len = 0; 2810 *names = NULL; 2811 *values = NULL; 2812 return 0; 2813 } 2814 2815 read_lock(&state->ss->policy_rwlock); 2816 2817 policydb = &state->ss->policydb; 2818 2819 *names = NULL; 2820 *values = NULL; 2821 2822 rc = 0; 2823 *len = policydb->p_bools.nprim; 2824 if (!*len) 2825 goto out; 2826 2827 rc = -ENOMEM; 2828 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2829 if (!*names) 2830 goto err; 2831 2832 rc = -ENOMEM; 2833 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2834 if (!*values) 2835 goto err; 2836 2837 for (i = 0; i < *len; i++) { 2838 (*values)[i] = policydb->bool_val_to_struct[i]->state; 2839 2840 rc = -ENOMEM; 2841 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 2842 GFP_ATOMIC); 2843 if (!(*names)[i]) 2844 goto err; 2845 } 2846 rc = 0; 2847 out: 2848 read_unlock(&state->ss->policy_rwlock); 2849 return rc; 2850 err: 2851 if (*names) { 2852 for (i = 0; i < *len; i++) 2853 kfree((*names)[i]); 2854 } 2855 kfree(*values); 2856 goto out; 2857 } 2858 2859 2860 int security_set_bools(struct selinux_state *state, int len, int *values) 2861 { 2862 struct policydb *policydb; 2863 int i, rc; 2864 int lenp, seqno = 0; 2865 struct cond_node *cur; 2866 2867 write_lock_irq(&state->ss->policy_rwlock); 2868 2869 policydb = &state->ss->policydb; 2870 2871 rc = -EFAULT; 2872 lenp = policydb->p_bools.nprim; 2873 if (len != lenp) 2874 goto out; 2875 2876 for (i = 0; i < len; i++) { 2877 if (!!values[i] != policydb->bool_val_to_struct[i]->state) { 2878 audit_log(audit_context(), GFP_ATOMIC, 2879 AUDIT_MAC_CONFIG_CHANGE, 2880 "bool=%s val=%d old_val=%d auid=%u ses=%u", 2881 sym_name(policydb, SYM_BOOLS, i), 2882 !!values[i], 2883 policydb->bool_val_to_struct[i]->state, 2884 from_kuid(&init_user_ns, audit_get_loginuid(current)), 2885 audit_get_sessionid(current)); 2886 } 2887 if (values[i]) 2888 policydb->bool_val_to_struct[i]->state = 1; 2889 else 2890 policydb->bool_val_to_struct[i]->state = 0; 2891 } 2892 2893 for (cur = policydb->cond_list; cur; cur = cur->next) { 2894 rc = evaluate_cond_node(policydb, cur); 2895 if (rc) 2896 goto out; 2897 } 2898 2899 seqno = ++state->ss->latest_granting; 2900 rc = 0; 2901 out: 2902 write_unlock_irq(&state->ss->policy_rwlock); 2903 if (!rc) { 2904 avc_ss_reset(state->avc, seqno); 2905 selnl_notify_policyload(seqno); 2906 selinux_status_update_policyload(state, seqno); 2907 selinux_xfrm_notify_policyload(); 2908 } 2909 return rc; 2910 } 2911 2912 int security_get_bool_value(struct selinux_state *state, 2913 int index) 2914 { 2915 struct policydb *policydb; 2916 int rc; 2917 int len; 2918 2919 read_lock(&state->ss->policy_rwlock); 2920 2921 policydb = &state->ss->policydb; 2922 2923 rc = -EFAULT; 2924 len = policydb->p_bools.nprim; 2925 if (index >= len) 2926 goto out; 2927 2928 rc = policydb->bool_val_to_struct[index]->state; 2929 out: 2930 read_unlock(&state->ss->policy_rwlock); 2931 return rc; 2932 } 2933 2934 static int security_preserve_bools(struct selinux_state *state, 2935 struct policydb *policydb) 2936 { 2937 int rc, nbools = 0, *bvalues = NULL, i; 2938 char **bnames = NULL; 2939 struct cond_bool_datum *booldatum; 2940 struct cond_node *cur; 2941 2942 rc = security_get_bools(state, &nbools, &bnames, &bvalues); 2943 if (rc) 2944 goto out; 2945 for (i = 0; i < nbools; i++) { 2946 booldatum = hashtab_search(policydb->p_bools.table, bnames[i]); 2947 if (booldatum) 2948 booldatum->state = bvalues[i]; 2949 } 2950 for (cur = policydb->cond_list; cur; cur = cur->next) { 2951 rc = evaluate_cond_node(policydb, cur); 2952 if (rc) 2953 goto out; 2954 } 2955 2956 out: 2957 if (bnames) { 2958 for (i = 0; i < nbools; i++) 2959 kfree(bnames[i]); 2960 } 2961 kfree(bnames); 2962 kfree(bvalues); 2963 return rc; 2964 } 2965 2966 /* 2967 * security_sid_mls_copy() - computes a new sid based on the given 2968 * sid and the mls portion of mls_sid. 2969 */ 2970 int security_sid_mls_copy(struct selinux_state *state, 2971 u32 sid, u32 mls_sid, u32 *new_sid) 2972 { 2973 struct policydb *policydb = &state->ss->policydb; 2974 struct sidtab *sidtab = state->ss->sidtab; 2975 struct context *context1; 2976 struct context *context2; 2977 struct context newcon; 2978 char *s; 2979 u32 len; 2980 int rc; 2981 2982 rc = 0; 2983 if (!state->initialized || !policydb->mls_enabled) { 2984 *new_sid = sid; 2985 goto out; 2986 } 2987 2988 context_init(&newcon); 2989 2990 read_lock(&state->ss->policy_rwlock); 2991 2992 rc = -EINVAL; 2993 context1 = sidtab_search(sidtab, sid); 2994 if (!context1) { 2995 pr_err("SELinux: %s: unrecognized SID %d\n", 2996 __func__, sid); 2997 goto out_unlock; 2998 } 2999 3000 rc = -EINVAL; 3001 context2 = sidtab_search(sidtab, mls_sid); 3002 if (!context2) { 3003 pr_err("SELinux: %s: unrecognized SID %d\n", 3004 __func__, mls_sid); 3005 goto out_unlock; 3006 } 3007 3008 newcon.user = context1->user; 3009 newcon.role = context1->role; 3010 newcon.type = context1->type; 3011 rc = mls_context_cpy(&newcon, context2); 3012 if (rc) 3013 goto out_unlock; 3014 3015 /* Check the validity of the new context. */ 3016 if (!policydb_context_isvalid(policydb, &newcon)) { 3017 rc = convert_context_handle_invalid_context(state, &newcon); 3018 if (rc) { 3019 if (!context_struct_to_string(policydb, &newcon, &s, 3020 &len)) { 3021 audit_log(audit_context(), 3022 GFP_ATOMIC, AUDIT_SELINUX_ERR, 3023 "op=security_sid_mls_copy " 3024 "invalid_context=%s", s); 3025 kfree(s); 3026 } 3027 goto out_unlock; 3028 } 3029 } 3030 3031 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3032 out_unlock: 3033 read_unlock(&state->ss->policy_rwlock); 3034 context_destroy(&newcon); 3035 out: 3036 return rc; 3037 } 3038 3039 /** 3040 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3041 * @nlbl_sid: NetLabel SID 3042 * @nlbl_type: NetLabel labeling protocol type 3043 * @xfrm_sid: XFRM SID 3044 * 3045 * Description: 3046 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3047 * resolved into a single SID it is returned via @peer_sid and the function 3048 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3049 * returns a negative value. A table summarizing the behavior is below: 3050 * 3051 * | function return | @sid 3052 * ------------------------------+-----------------+----------------- 3053 * no peer labels | 0 | SECSID_NULL 3054 * single peer label | 0 | <peer_label> 3055 * multiple, consistent labels | 0 | <peer_label> 3056 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3057 * 3058 */ 3059 int security_net_peersid_resolve(struct selinux_state *state, 3060 u32 nlbl_sid, u32 nlbl_type, 3061 u32 xfrm_sid, 3062 u32 *peer_sid) 3063 { 3064 struct policydb *policydb = &state->ss->policydb; 3065 struct sidtab *sidtab = state->ss->sidtab; 3066 int rc; 3067 struct context *nlbl_ctx; 3068 struct context *xfrm_ctx; 3069 3070 *peer_sid = SECSID_NULL; 3071 3072 /* handle the common (which also happens to be the set of easy) cases 3073 * right away, these two if statements catch everything involving a 3074 * single or absent peer SID/label */ 3075 if (xfrm_sid == SECSID_NULL) { 3076 *peer_sid = nlbl_sid; 3077 return 0; 3078 } 3079 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3080 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3081 * is present */ 3082 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3083 *peer_sid = xfrm_sid; 3084 return 0; 3085 } 3086 3087 /* 3088 * We don't need to check initialized here since the only way both 3089 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3090 * security server was initialized and state->initialized was true. 3091 */ 3092 if (!policydb->mls_enabled) 3093 return 0; 3094 3095 read_lock(&state->ss->policy_rwlock); 3096 3097 rc = -EINVAL; 3098 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3099 if (!nlbl_ctx) { 3100 pr_err("SELinux: %s: unrecognized SID %d\n", 3101 __func__, nlbl_sid); 3102 goto out; 3103 } 3104 rc = -EINVAL; 3105 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3106 if (!xfrm_ctx) { 3107 pr_err("SELinux: %s: unrecognized SID %d\n", 3108 __func__, xfrm_sid); 3109 goto out; 3110 } 3111 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3112 if (rc) 3113 goto out; 3114 3115 /* at present NetLabel SIDs/labels really only carry MLS 3116 * information so if the MLS portion of the NetLabel SID 3117 * matches the MLS portion of the labeled XFRM SID/label 3118 * then pass along the XFRM SID as it is the most 3119 * expressive */ 3120 *peer_sid = xfrm_sid; 3121 out: 3122 read_unlock(&state->ss->policy_rwlock); 3123 return rc; 3124 } 3125 3126 static int get_classes_callback(void *k, void *d, void *args) 3127 { 3128 struct class_datum *datum = d; 3129 char *name = k, **classes = args; 3130 int value = datum->value - 1; 3131 3132 classes[value] = kstrdup(name, GFP_ATOMIC); 3133 if (!classes[value]) 3134 return -ENOMEM; 3135 3136 return 0; 3137 } 3138 3139 int security_get_classes(struct selinux_state *state, 3140 char ***classes, int *nclasses) 3141 { 3142 struct policydb *policydb = &state->ss->policydb; 3143 int rc; 3144 3145 if (!state->initialized) { 3146 *nclasses = 0; 3147 *classes = NULL; 3148 return 0; 3149 } 3150 3151 read_lock(&state->ss->policy_rwlock); 3152 3153 rc = -ENOMEM; 3154 *nclasses = policydb->p_classes.nprim; 3155 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3156 if (!*classes) 3157 goto out; 3158 3159 rc = hashtab_map(policydb->p_classes.table, get_classes_callback, 3160 *classes); 3161 if (rc) { 3162 int i; 3163 for (i = 0; i < *nclasses; i++) 3164 kfree((*classes)[i]); 3165 kfree(*classes); 3166 } 3167 3168 out: 3169 read_unlock(&state->ss->policy_rwlock); 3170 return rc; 3171 } 3172 3173 static int get_permissions_callback(void *k, void *d, void *args) 3174 { 3175 struct perm_datum *datum = d; 3176 char *name = k, **perms = args; 3177 int value = datum->value - 1; 3178 3179 perms[value] = kstrdup(name, GFP_ATOMIC); 3180 if (!perms[value]) 3181 return -ENOMEM; 3182 3183 return 0; 3184 } 3185 3186 int security_get_permissions(struct selinux_state *state, 3187 char *class, char ***perms, int *nperms) 3188 { 3189 struct policydb *policydb = &state->ss->policydb; 3190 int rc, i; 3191 struct class_datum *match; 3192 3193 read_lock(&state->ss->policy_rwlock); 3194 3195 rc = -EINVAL; 3196 match = hashtab_search(policydb->p_classes.table, class); 3197 if (!match) { 3198 pr_err("SELinux: %s: unrecognized class %s\n", 3199 __func__, class); 3200 goto out; 3201 } 3202 3203 rc = -ENOMEM; 3204 *nperms = match->permissions.nprim; 3205 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3206 if (!*perms) 3207 goto out; 3208 3209 if (match->comdatum) { 3210 rc = hashtab_map(match->comdatum->permissions.table, 3211 get_permissions_callback, *perms); 3212 if (rc) 3213 goto err; 3214 } 3215 3216 rc = hashtab_map(match->permissions.table, get_permissions_callback, 3217 *perms); 3218 if (rc) 3219 goto err; 3220 3221 out: 3222 read_unlock(&state->ss->policy_rwlock); 3223 return rc; 3224 3225 err: 3226 read_unlock(&state->ss->policy_rwlock); 3227 for (i = 0; i < *nperms; i++) 3228 kfree((*perms)[i]); 3229 kfree(*perms); 3230 return rc; 3231 } 3232 3233 int security_get_reject_unknown(struct selinux_state *state) 3234 { 3235 return state->ss->policydb.reject_unknown; 3236 } 3237 3238 int security_get_allow_unknown(struct selinux_state *state) 3239 { 3240 return state->ss->policydb.allow_unknown; 3241 } 3242 3243 /** 3244 * security_policycap_supported - Check for a specific policy capability 3245 * @req_cap: capability 3246 * 3247 * Description: 3248 * This function queries the currently loaded policy to see if it supports the 3249 * capability specified by @req_cap. Returns true (1) if the capability is 3250 * supported, false (0) if it isn't supported. 3251 * 3252 */ 3253 int security_policycap_supported(struct selinux_state *state, 3254 unsigned int req_cap) 3255 { 3256 struct policydb *policydb = &state->ss->policydb; 3257 int rc; 3258 3259 read_lock(&state->ss->policy_rwlock); 3260 rc = ebitmap_get_bit(&policydb->policycaps, req_cap); 3261 read_unlock(&state->ss->policy_rwlock); 3262 3263 return rc; 3264 } 3265 3266 struct selinux_audit_rule { 3267 u32 au_seqno; 3268 struct context au_ctxt; 3269 }; 3270 3271 void selinux_audit_rule_free(void *vrule) 3272 { 3273 struct selinux_audit_rule *rule = vrule; 3274 3275 if (rule) { 3276 context_destroy(&rule->au_ctxt); 3277 kfree(rule); 3278 } 3279 } 3280 3281 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3282 { 3283 struct selinux_state *state = &selinux_state; 3284 struct policydb *policydb = &state->ss->policydb; 3285 struct selinux_audit_rule *tmprule; 3286 struct role_datum *roledatum; 3287 struct type_datum *typedatum; 3288 struct user_datum *userdatum; 3289 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3290 int rc = 0; 3291 3292 *rule = NULL; 3293 3294 if (!state->initialized) 3295 return -EOPNOTSUPP; 3296 3297 switch (field) { 3298 case AUDIT_SUBJ_USER: 3299 case AUDIT_SUBJ_ROLE: 3300 case AUDIT_SUBJ_TYPE: 3301 case AUDIT_OBJ_USER: 3302 case AUDIT_OBJ_ROLE: 3303 case AUDIT_OBJ_TYPE: 3304 /* only 'equals' and 'not equals' fit user, role, and type */ 3305 if (op != Audit_equal && op != Audit_not_equal) 3306 return -EINVAL; 3307 break; 3308 case AUDIT_SUBJ_SEN: 3309 case AUDIT_SUBJ_CLR: 3310 case AUDIT_OBJ_LEV_LOW: 3311 case AUDIT_OBJ_LEV_HIGH: 3312 /* we do not allow a range, indicated by the presence of '-' */ 3313 if (strchr(rulestr, '-')) 3314 return -EINVAL; 3315 break; 3316 default: 3317 /* only the above fields are valid */ 3318 return -EINVAL; 3319 } 3320 3321 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3322 if (!tmprule) 3323 return -ENOMEM; 3324 3325 context_init(&tmprule->au_ctxt); 3326 3327 read_lock(&state->ss->policy_rwlock); 3328 3329 tmprule->au_seqno = state->ss->latest_granting; 3330 3331 switch (field) { 3332 case AUDIT_SUBJ_USER: 3333 case AUDIT_OBJ_USER: 3334 rc = -EINVAL; 3335 userdatum = hashtab_search(policydb->p_users.table, rulestr); 3336 if (!userdatum) 3337 goto out; 3338 tmprule->au_ctxt.user = userdatum->value; 3339 break; 3340 case AUDIT_SUBJ_ROLE: 3341 case AUDIT_OBJ_ROLE: 3342 rc = -EINVAL; 3343 roledatum = hashtab_search(policydb->p_roles.table, rulestr); 3344 if (!roledatum) 3345 goto out; 3346 tmprule->au_ctxt.role = roledatum->value; 3347 break; 3348 case AUDIT_SUBJ_TYPE: 3349 case AUDIT_OBJ_TYPE: 3350 rc = -EINVAL; 3351 typedatum = hashtab_search(policydb->p_types.table, rulestr); 3352 if (!typedatum) 3353 goto out; 3354 tmprule->au_ctxt.type = typedatum->value; 3355 break; 3356 case AUDIT_SUBJ_SEN: 3357 case AUDIT_SUBJ_CLR: 3358 case AUDIT_OBJ_LEV_LOW: 3359 case AUDIT_OBJ_LEV_HIGH: 3360 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3361 GFP_ATOMIC); 3362 if (rc) 3363 goto out; 3364 break; 3365 } 3366 rc = 0; 3367 out: 3368 read_unlock(&state->ss->policy_rwlock); 3369 3370 if (rc) { 3371 selinux_audit_rule_free(tmprule); 3372 tmprule = NULL; 3373 } 3374 3375 *rule = tmprule; 3376 3377 return rc; 3378 } 3379 3380 /* Check to see if the rule contains any selinux fields */ 3381 int selinux_audit_rule_known(struct audit_krule *rule) 3382 { 3383 int i; 3384 3385 for (i = 0; i < rule->field_count; i++) { 3386 struct audit_field *f = &rule->fields[i]; 3387 switch (f->type) { 3388 case AUDIT_SUBJ_USER: 3389 case AUDIT_SUBJ_ROLE: 3390 case AUDIT_SUBJ_TYPE: 3391 case AUDIT_SUBJ_SEN: 3392 case AUDIT_SUBJ_CLR: 3393 case AUDIT_OBJ_USER: 3394 case AUDIT_OBJ_ROLE: 3395 case AUDIT_OBJ_TYPE: 3396 case AUDIT_OBJ_LEV_LOW: 3397 case AUDIT_OBJ_LEV_HIGH: 3398 return 1; 3399 } 3400 } 3401 3402 return 0; 3403 } 3404 3405 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) 3406 { 3407 struct selinux_state *state = &selinux_state; 3408 struct context *ctxt; 3409 struct mls_level *level; 3410 struct selinux_audit_rule *rule = vrule; 3411 int match = 0; 3412 3413 if (unlikely(!rule)) { 3414 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3415 return -ENOENT; 3416 } 3417 3418 read_lock(&state->ss->policy_rwlock); 3419 3420 if (rule->au_seqno < state->ss->latest_granting) { 3421 match = -ESTALE; 3422 goto out; 3423 } 3424 3425 ctxt = sidtab_search(state->ss->sidtab, sid); 3426 if (unlikely(!ctxt)) { 3427 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3428 sid); 3429 match = -ENOENT; 3430 goto out; 3431 } 3432 3433 /* a field/op pair that is not caught here will simply fall through 3434 without a match */ 3435 switch (field) { 3436 case AUDIT_SUBJ_USER: 3437 case AUDIT_OBJ_USER: 3438 switch (op) { 3439 case Audit_equal: 3440 match = (ctxt->user == rule->au_ctxt.user); 3441 break; 3442 case Audit_not_equal: 3443 match = (ctxt->user != rule->au_ctxt.user); 3444 break; 3445 } 3446 break; 3447 case AUDIT_SUBJ_ROLE: 3448 case AUDIT_OBJ_ROLE: 3449 switch (op) { 3450 case Audit_equal: 3451 match = (ctxt->role == rule->au_ctxt.role); 3452 break; 3453 case Audit_not_equal: 3454 match = (ctxt->role != rule->au_ctxt.role); 3455 break; 3456 } 3457 break; 3458 case AUDIT_SUBJ_TYPE: 3459 case AUDIT_OBJ_TYPE: 3460 switch (op) { 3461 case Audit_equal: 3462 match = (ctxt->type == rule->au_ctxt.type); 3463 break; 3464 case Audit_not_equal: 3465 match = (ctxt->type != rule->au_ctxt.type); 3466 break; 3467 } 3468 break; 3469 case AUDIT_SUBJ_SEN: 3470 case AUDIT_SUBJ_CLR: 3471 case AUDIT_OBJ_LEV_LOW: 3472 case AUDIT_OBJ_LEV_HIGH: 3473 level = ((field == AUDIT_SUBJ_SEN || 3474 field == AUDIT_OBJ_LEV_LOW) ? 3475 &ctxt->range.level[0] : &ctxt->range.level[1]); 3476 switch (op) { 3477 case Audit_equal: 3478 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3479 level); 3480 break; 3481 case Audit_not_equal: 3482 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3483 level); 3484 break; 3485 case Audit_lt: 3486 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3487 level) && 3488 !mls_level_eq(&rule->au_ctxt.range.level[0], 3489 level)); 3490 break; 3491 case Audit_le: 3492 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3493 level); 3494 break; 3495 case Audit_gt: 3496 match = (mls_level_dom(level, 3497 &rule->au_ctxt.range.level[0]) && 3498 !mls_level_eq(level, 3499 &rule->au_ctxt.range.level[0])); 3500 break; 3501 case Audit_ge: 3502 match = mls_level_dom(level, 3503 &rule->au_ctxt.range.level[0]); 3504 break; 3505 } 3506 } 3507 3508 out: 3509 read_unlock(&state->ss->policy_rwlock); 3510 return match; 3511 } 3512 3513 static int (*aurule_callback)(void) = audit_update_lsm_rules; 3514 3515 static int aurule_avc_callback(u32 event) 3516 { 3517 int err = 0; 3518 3519 if (event == AVC_CALLBACK_RESET && aurule_callback) 3520 err = aurule_callback(); 3521 return err; 3522 } 3523 3524 static int __init aurule_init(void) 3525 { 3526 int err; 3527 3528 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3529 if (err) 3530 panic("avc_add_callback() failed, error %d\n", err); 3531 3532 return err; 3533 } 3534 __initcall(aurule_init); 3535 3536 #ifdef CONFIG_NETLABEL 3537 /** 3538 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3539 * @secattr: the NetLabel packet security attributes 3540 * @sid: the SELinux SID 3541 * 3542 * Description: 3543 * Attempt to cache the context in @ctx, which was derived from the packet in 3544 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3545 * already been initialized. 3546 * 3547 */ 3548 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3549 u32 sid) 3550 { 3551 u32 *sid_cache; 3552 3553 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3554 if (sid_cache == NULL) 3555 return; 3556 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3557 if (secattr->cache == NULL) { 3558 kfree(sid_cache); 3559 return; 3560 } 3561 3562 *sid_cache = sid; 3563 secattr->cache->free = kfree; 3564 secattr->cache->data = sid_cache; 3565 secattr->flags |= NETLBL_SECATTR_CACHE; 3566 } 3567 3568 /** 3569 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3570 * @secattr: the NetLabel packet security attributes 3571 * @sid: the SELinux SID 3572 * 3573 * Description: 3574 * Convert the given NetLabel security attributes in @secattr into a 3575 * SELinux SID. If the @secattr field does not contain a full SELinux 3576 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3577 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3578 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3579 * conversion for future lookups. Returns zero on success, negative values on 3580 * failure. 3581 * 3582 */ 3583 int security_netlbl_secattr_to_sid(struct selinux_state *state, 3584 struct netlbl_lsm_secattr *secattr, 3585 u32 *sid) 3586 { 3587 struct policydb *policydb = &state->ss->policydb; 3588 struct sidtab *sidtab = state->ss->sidtab; 3589 int rc; 3590 struct context *ctx; 3591 struct context ctx_new; 3592 3593 if (!state->initialized) { 3594 *sid = SECSID_NULL; 3595 return 0; 3596 } 3597 3598 read_lock(&state->ss->policy_rwlock); 3599 3600 if (secattr->flags & NETLBL_SECATTR_CACHE) 3601 *sid = *(u32 *)secattr->cache->data; 3602 else if (secattr->flags & NETLBL_SECATTR_SECID) 3603 *sid = secattr->attr.secid; 3604 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3605 rc = -EIDRM; 3606 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3607 if (ctx == NULL) 3608 goto out; 3609 3610 context_init(&ctx_new); 3611 ctx_new.user = ctx->user; 3612 ctx_new.role = ctx->role; 3613 ctx_new.type = ctx->type; 3614 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3615 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3616 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3617 if (rc) 3618 goto out; 3619 } 3620 rc = -EIDRM; 3621 if (!mls_context_isvalid(policydb, &ctx_new)) 3622 goto out_free; 3623 3624 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3625 if (rc) 3626 goto out_free; 3627 3628 security_netlbl_cache_add(secattr, *sid); 3629 3630 ebitmap_destroy(&ctx_new.range.level[0].cat); 3631 } else 3632 *sid = SECSID_NULL; 3633 3634 read_unlock(&state->ss->policy_rwlock); 3635 return 0; 3636 out_free: 3637 ebitmap_destroy(&ctx_new.range.level[0].cat); 3638 out: 3639 read_unlock(&state->ss->policy_rwlock); 3640 return rc; 3641 } 3642 3643 /** 3644 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3645 * @sid: the SELinux SID 3646 * @secattr: the NetLabel packet security attributes 3647 * 3648 * Description: 3649 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3650 * Returns zero on success, negative values on failure. 3651 * 3652 */ 3653 int security_netlbl_sid_to_secattr(struct selinux_state *state, 3654 u32 sid, struct netlbl_lsm_secattr *secattr) 3655 { 3656 struct policydb *policydb = &state->ss->policydb; 3657 int rc; 3658 struct context *ctx; 3659 3660 if (!state->initialized) 3661 return 0; 3662 3663 read_lock(&state->ss->policy_rwlock); 3664 3665 rc = -ENOENT; 3666 ctx = sidtab_search(state->ss->sidtab, sid); 3667 if (ctx == NULL) 3668 goto out; 3669 3670 rc = -ENOMEM; 3671 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3672 GFP_ATOMIC); 3673 if (secattr->domain == NULL) 3674 goto out; 3675 3676 secattr->attr.secid = sid; 3677 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3678 mls_export_netlbl_lvl(policydb, ctx, secattr); 3679 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3680 out: 3681 read_unlock(&state->ss->policy_rwlock); 3682 return rc; 3683 } 3684 #endif /* CONFIG_NETLABEL */ 3685 3686 /** 3687 * security_read_policy - read the policy. 3688 * @data: binary policy data 3689 * @len: length of data in bytes 3690 * 3691 */ 3692 int security_read_policy(struct selinux_state *state, 3693 void **data, size_t *len) 3694 { 3695 struct policydb *policydb = &state->ss->policydb; 3696 int rc; 3697 struct policy_file fp; 3698 3699 if (!state->initialized) 3700 return -EINVAL; 3701 3702 *len = security_policydb_len(state); 3703 3704 *data = vmalloc_user(*len); 3705 if (!*data) 3706 return -ENOMEM; 3707 3708 fp.data = *data; 3709 fp.len = *len; 3710 3711 read_lock(&state->ss->policy_rwlock); 3712 rc = policydb_write(policydb, &fp); 3713 read_unlock(&state->ss->policy_rwlock); 3714 3715 if (rc) 3716 return rc; 3717 3718 *len = (unsigned long)fp.data - (unsigned long)*data; 3719 return 0; 3720 3721 } 3722