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/selinux.h> 53 #include <linux/flex_array.h> 54 #include <linux/vmalloc.h> 55 #include <net/netlabel.h> 56 57 #include "flask.h" 58 #include "avc.h" 59 #include "avc_ss.h" 60 #include "security.h" 61 #include "context.h" 62 #include "policydb.h" 63 #include "sidtab.h" 64 #include "services.h" 65 #include "conditional.h" 66 #include "mls.h" 67 #include "objsec.h" 68 #include "netlabel.h" 69 #include "xfrm.h" 70 #include "ebitmap.h" 71 #include "audit.h" 72 73 /* Policy capability names */ 74 char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = { 75 "network_peer_controls", 76 "open_perms", 77 "extended_socket_class", 78 "always_check_network", 79 "cgroup_seclabel", 80 "nnp_nosuid_transition" 81 }; 82 83 static struct selinux_ss selinux_ss; 84 85 void selinux_ss_init(struct selinux_ss **ss) 86 { 87 rwlock_init(&selinux_ss.policy_rwlock); 88 mutex_init(&selinux_ss.status_lock); 89 *ss = &selinux_ss; 90 } 91 92 /* Forward declaration. */ 93 static int context_struct_to_string(struct policydb *policydb, 94 struct context *context, 95 char **scontext, 96 u32 *scontext_len); 97 98 static void context_struct_compute_av(struct policydb *policydb, 99 struct context *scontext, 100 struct context *tcontext, 101 u16 tclass, 102 struct av_decision *avd, 103 struct extended_perms *xperms); 104 105 static int selinux_set_mapping(struct policydb *pol, 106 struct security_class_mapping *map, 107 struct selinux_map *out_map) 108 { 109 u16 i, j; 110 unsigned k; 111 bool print_unknown_handle = false; 112 113 /* Find number of classes in the input mapping */ 114 if (!map) 115 return -EINVAL; 116 i = 0; 117 while (map[i].name) 118 i++; 119 120 /* Allocate space for the class records, plus one for class zero */ 121 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 122 if (!out_map->mapping) 123 return -ENOMEM; 124 125 /* Store the raw class and permission values */ 126 j = 0; 127 while (map[j].name) { 128 struct security_class_mapping *p_in = map + (j++); 129 struct selinux_mapping *p_out = out_map->mapping + j; 130 131 /* An empty class string skips ahead */ 132 if (!strcmp(p_in->name, "")) { 133 p_out->num_perms = 0; 134 continue; 135 } 136 137 p_out->value = string_to_security_class(pol, p_in->name); 138 if (!p_out->value) { 139 pr_info("SELinux: Class %s not defined in policy.\n", 140 p_in->name); 141 if (pol->reject_unknown) 142 goto err; 143 p_out->num_perms = 0; 144 print_unknown_handle = true; 145 continue; 146 } 147 148 k = 0; 149 while (p_in->perms[k]) { 150 /* An empty permission string skips ahead */ 151 if (!*p_in->perms[k]) { 152 k++; 153 continue; 154 } 155 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 156 p_in->perms[k]); 157 if (!p_out->perms[k]) { 158 pr_info("SELinux: Permission %s in class %s not defined in policy.\n", 159 p_in->perms[k], p_in->name); 160 if (pol->reject_unknown) 161 goto err; 162 print_unknown_handle = true; 163 } 164 165 k++; 166 } 167 p_out->num_perms = k; 168 } 169 170 if (print_unknown_handle) 171 pr_info("SELinux: the above unknown classes and permissions will be %s\n", 172 pol->allow_unknown ? "allowed" : "denied"); 173 174 out_map->size = i; 175 return 0; 176 err: 177 kfree(out_map->mapping); 178 out_map->mapping = NULL; 179 return -EINVAL; 180 } 181 182 /* 183 * Get real, policy values from mapped values 184 */ 185 186 static u16 unmap_class(struct selinux_map *map, u16 tclass) 187 { 188 if (tclass < map->size) 189 return map->mapping[tclass].value; 190 191 return tclass; 192 } 193 194 /* 195 * Get kernel value for class from its policy value 196 */ 197 static u16 map_class(struct selinux_map *map, u16 pol_value) 198 { 199 u16 i; 200 201 for (i = 1; i < map->size; i++) { 202 if (map->mapping[i].value == pol_value) 203 return i; 204 } 205 206 return SECCLASS_NULL; 207 } 208 209 static void map_decision(struct selinux_map *map, 210 u16 tclass, struct av_decision *avd, 211 int allow_unknown) 212 { 213 if (tclass < map->size) { 214 struct selinux_mapping *mapping = &map->mapping[tclass]; 215 unsigned int i, n = mapping->num_perms; 216 u32 result; 217 218 for (i = 0, result = 0; i < n; i++) { 219 if (avd->allowed & mapping->perms[i]) 220 result |= 1<<i; 221 if (allow_unknown && !mapping->perms[i]) 222 result |= 1<<i; 223 } 224 avd->allowed = result; 225 226 for (i = 0, result = 0; i < n; i++) 227 if (avd->auditallow & mapping->perms[i]) 228 result |= 1<<i; 229 avd->auditallow = result; 230 231 for (i = 0, result = 0; i < n; i++) { 232 if (avd->auditdeny & mapping->perms[i]) 233 result |= 1<<i; 234 if (!allow_unknown && !mapping->perms[i]) 235 result |= 1<<i; 236 } 237 /* 238 * In case the kernel has a bug and requests a permission 239 * between num_perms and the maximum permission number, we 240 * should audit that denial 241 */ 242 for (; i < (sizeof(u32)*8); i++) 243 result |= 1<<i; 244 avd->auditdeny = result; 245 } 246 } 247 248 int security_mls_enabled(struct selinux_state *state) 249 { 250 struct policydb *p = &state->ss->policydb; 251 252 return p->mls_enabled; 253 } 254 255 /* 256 * Return the boolean value of a constraint expression 257 * when it is applied to the specified source and target 258 * security contexts. 259 * 260 * xcontext is a special beast... It is used by the validatetrans rules 261 * only. For these rules, scontext is the context before the transition, 262 * tcontext is the context after the transition, and xcontext is the context 263 * of the process performing the transition. All other callers of 264 * constraint_expr_eval should pass in NULL for xcontext. 265 */ 266 static int constraint_expr_eval(struct policydb *policydb, 267 struct context *scontext, 268 struct context *tcontext, 269 struct context *xcontext, 270 struct constraint_expr *cexpr) 271 { 272 u32 val1, val2; 273 struct context *c; 274 struct role_datum *r1, *r2; 275 struct mls_level *l1, *l2; 276 struct constraint_expr *e; 277 int s[CEXPR_MAXDEPTH]; 278 int sp = -1; 279 280 for (e = cexpr; e; e = e->next) { 281 switch (e->expr_type) { 282 case CEXPR_NOT: 283 BUG_ON(sp < 0); 284 s[sp] = !s[sp]; 285 break; 286 case CEXPR_AND: 287 BUG_ON(sp < 1); 288 sp--; 289 s[sp] &= s[sp + 1]; 290 break; 291 case CEXPR_OR: 292 BUG_ON(sp < 1); 293 sp--; 294 s[sp] |= s[sp + 1]; 295 break; 296 case CEXPR_ATTR: 297 if (sp == (CEXPR_MAXDEPTH - 1)) 298 return 0; 299 switch (e->attr) { 300 case CEXPR_USER: 301 val1 = scontext->user; 302 val2 = tcontext->user; 303 break; 304 case CEXPR_TYPE: 305 val1 = scontext->type; 306 val2 = tcontext->type; 307 break; 308 case CEXPR_ROLE: 309 val1 = scontext->role; 310 val2 = tcontext->role; 311 r1 = policydb->role_val_to_struct[val1 - 1]; 312 r2 = policydb->role_val_to_struct[val2 - 1]; 313 switch (e->op) { 314 case CEXPR_DOM: 315 s[++sp] = ebitmap_get_bit(&r1->dominates, 316 val2 - 1); 317 continue; 318 case CEXPR_DOMBY: 319 s[++sp] = ebitmap_get_bit(&r2->dominates, 320 val1 - 1); 321 continue; 322 case CEXPR_INCOMP: 323 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 324 val2 - 1) && 325 !ebitmap_get_bit(&r2->dominates, 326 val1 - 1)); 327 continue; 328 default: 329 break; 330 } 331 break; 332 case CEXPR_L1L2: 333 l1 = &(scontext->range.level[0]); 334 l2 = &(tcontext->range.level[0]); 335 goto mls_ops; 336 case CEXPR_L1H2: 337 l1 = &(scontext->range.level[0]); 338 l2 = &(tcontext->range.level[1]); 339 goto mls_ops; 340 case CEXPR_H1L2: 341 l1 = &(scontext->range.level[1]); 342 l2 = &(tcontext->range.level[0]); 343 goto mls_ops; 344 case CEXPR_H1H2: 345 l1 = &(scontext->range.level[1]); 346 l2 = &(tcontext->range.level[1]); 347 goto mls_ops; 348 case CEXPR_L1H1: 349 l1 = &(scontext->range.level[0]); 350 l2 = &(scontext->range.level[1]); 351 goto mls_ops; 352 case CEXPR_L2H2: 353 l1 = &(tcontext->range.level[0]); 354 l2 = &(tcontext->range.level[1]); 355 goto mls_ops; 356 mls_ops: 357 switch (e->op) { 358 case CEXPR_EQ: 359 s[++sp] = mls_level_eq(l1, l2); 360 continue; 361 case CEXPR_NEQ: 362 s[++sp] = !mls_level_eq(l1, l2); 363 continue; 364 case CEXPR_DOM: 365 s[++sp] = mls_level_dom(l1, l2); 366 continue; 367 case CEXPR_DOMBY: 368 s[++sp] = mls_level_dom(l2, l1); 369 continue; 370 case CEXPR_INCOMP: 371 s[++sp] = mls_level_incomp(l2, l1); 372 continue; 373 default: 374 BUG(); 375 return 0; 376 } 377 break; 378 default: 379 BUG(); 380 return 0; 381 } 382 383 switch (e->op) { 384 case CEXPR_EQ: 385 s[++sp] = (val1 == val2); 386 break; 387 case CEXPR_NEQ: 388 s[++sp] = (val1 != val2); 389 break; 390 default: 391 BUG(); 392 return 0; 393 } 394 break; 395 case CEXPR_NAMES: 396 if (sp == (CEXPR_MAXDEPTH-1)) 397 return 0; 398 c = scontext; 399 if (e->attr & CEXPR_TARGET) 400 c = tcontext; 401 else if (e->attr & CEXPR_XTARGET) { 402 c = xcontext; 403 if (!c) { 404 BUG(); 405 return 0; 406 } 407 } 408 if (e->attr & CEXPR_USER) 409 val1 = c->user; 410 else if (e->attr & CEXPR_ROLE) 411 val1 = c->role; 412 else if (e->attr & CEXPR_TYPE) 413 val1 = c->type; 414 else { 415 BUG(); 416 return 0; 417 } 418 419 switch (e->op) { 420 case CEXPR_EQ: 421 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 422 break; 423 case CEXPR_NEQ: 424 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 425 break; 426 default: 427 BUG(); 428 return 0; 429 } 430 break; 431 default: 432 BUG(); 433 return 0; 434 } 435 } 436 437 BUG_ON(sp != 0); 438 return s[0]; 439 } 440 441 /* 442 * security_dump_masked_av - dumps masked permissions during 443 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 444 */ 445 static int dump_masked_av_helper(void *k, void *d, void *args) 446 { 447 struct perm_datum *pdatum = d; 448 char **permission_names = args; 449 450 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 451 452 permission_names[pdatum->value - 1] = (char *)k; 453 454 return 0; 455 } 456 457 static void security_dump_masked_av(struct policydb *policydb, 458 struct context *scontext, 459 struct context *tcontext, 460 u16 tclass, 461 u32 permissions, 462 const char *reason) 463 { 464 struct common_datum *common_dat; 465 struct class_datum *tclass_dat; 466 struct audit_buffer *ab; 467 char *tclass_name; 468 char *scontext_name = NULL; 469 char *tcontext_name = NULL; 470 char *permission_names[32]; 471 int index; 472 u32 length; 473 bool need_comma = false; 474 475 if (!permissions) 476 return; 477 478 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); 479 tclass_dat = policydb->class_val_to_struct[tclass - 1]; 480 common_dat = tclass_dat->comdatum; 481 482 /* init permission_names */ 483 if (common_dat && 484 hashtab_map(common_dat->permissions.table, 485 dump_masked_av_helper, permission_names) < 0) 486 goto out; 487 488 if (hashtab_map(tclass_dat->permissions.table, 489 dump_masked_av_helper, permission_names) < 0) 490 goto out; 491 492 /* get scontext/tcontext in text form */ 493 if (context_struct_to_string(policydb, scontext, 494 &scontext_name, &length) < 0) 495 goto out; 496 497 if (context_struct_to_string(policydb, tcontext, 498 &tcontext_name, &length) < 0) 499 goto out; 500 501 /* audit a message */ 502 ab = audit_log_start(audit_context(), 503 GFP_ATOMIC, AUDIT_SELINUX_ERR); 504 if (!ab) 505 goto out; 506 507 audit_log_format(ab, "op=security_compute_av reason=%s " 508 "scontext=%s tcontext=%s tclass=%s perms=", 509 reason, scontext_name, tcontext_name, tclass_name); 510 511 for (index = 0; index < 32; index++) { 512 u32 mask = (1 << index); 513 514 if ((mask & permissions) == 0) 515 continue; 516 517 audit_log_format(ab, "%s%s", 518 need_comma ? "," : "", 519 permission_names[index] 520 ? permission_names[index] : "????"); 521 need_comma = true; 522 } 523 audit_log_end(ab); 524 out: 525 /* release scontext/tcontext */ 526 kfree(tcontext_name); 527 kfree(scontext_name); 528 529 return; 530 } 531 532 /* 533 * security_boundary_permission - drops violated permissions 534 * on boundary constraint. 535 */ 536 static void type_attribute_bounds_av(struct policydb *policydb, 537 struct context *scontext, 538 struct context *tcontext, 539 u16 tclass, 540 struct av_decision *avd) 541 { 542 struct context lo_scontext; 543 struct context lo_tcontext, *tcontextp = tcontext; 544 struct av_decision lo_avd; 545 struct type_datum *source; 546 struct type_datum *target; 547 u32 masked = 0; 548 549 source = flex_array_get_ptr(policydb->type_val_to_struct_array, 550 scontext->type - 1); 551 BUG_ON(!source); 552 553 if (!source->bounds) 554 return; 555 556 target = flex_array_get_ptr(policydb->type_val_to_struct_array, 557 tcontext->type - 1); 558 BUG_ON(!target); 559 560 memset(&lo_avd, 0, sizeof(lo_avd)); 561 562 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 563 lo_scontext.type = source->bounds; 564 565 if (target->bounds) { 566 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 567 lo_tcontext.type = target->bounds; 568 tcontextp = &lo_tcontext; 569 } 570 571 context_struct_compute_av(policydb, &lo_scontext, 572 tcontextp, 573 tclass, 574 &lo_avd, 575 NULL); 576 577 masked = ~lo_avd.allowed & avd->allowed; 578 579 if (likely(!masked)) 580 return; /* no masked permission */ 581 582 /* mask violated permissions */ 583 avd->allowed &= ~masked; 584 585 /* audit masked permissions */ 586 security_dump_masked_av(policydb, scontext, tcontext, 587 tclass, masked, "bounds"); 588 } 589 590 /* 591 * flag which drivers have permissions 592 * only looking for ioctl based extended permssions 593 */ 594 void services_compute_xperms_drivers( 595 struct extended_perms *xperms, 596 struct avtab_node *node) 597 { 598 unsigned int i; 599 600 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 601 /* if one or more driver has all permissions allowed */ 602 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 603 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 604 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 605 /* if allowing permissions within a driver */ 606 security_xperm_set(xperms->drivers.p, 607 node->datum.u.xperms->driver); 608 } 609 610 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */ 611 if (node->key.specified & AVTAB_XPERMS_ALLOWED) 612 xperms->len = 1; 613 } 614 615 /* 616 * Compute access vectors and extended permissions based on a context 617 * structure pair for the permissions in a particular class. 618 */ 619 static void context_struct_compute_av(struct policydb *policydb, 620 struct context *scontext, 621 struct context *tcontext, 622 u16 tclass, 623 struct av_decision *avd, 624 struct extended_perms *xperms) 625 { 626 struct constraint_node *constraint; 627 struct role_allow *ra; 628 struct avtab_key avkey; 629 struct avtab_node *node; 630 struct class_datum *tclass_datum; 631 struct ebitmap *sattr, *tattr; 632 struct ebitmap_node *snode, *tnode; 633 unsigned int i, j; 634 635 avd->allowed = 0; 636 avd->auditallow = 0; 637 avd->auditdeny = 0xffffffff; 638 if (xperms) { 639 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 640 xperms->len = 0; 641 } 642 643 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 644 if (printk_ratelimit()) 645 pr_warn("SELinux: Invalid class %hu\n", tclass); 646 return; 647 } 648 649 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 650 651 /* 652 * If a specific type enforcement rule was defined for 653 * this permission check, then use it. 654 */ 655 avkey.target_class = tclass; 656 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 657 sattr = flex_array_get(policydb->type_attr_map_array, 658 scontext->type - 1); 659 BUG_ON(!sattr); 660 tattr = flex_array_get(policydb->type_attr_map_array, 661 tcontext->type - 1); 662 BUG_ON(!tattr); 663 ebitmap_for_each_positive_bit(sattr, snode, i) { 664 ebitmap_for_each_positive_bit(tattr, tnode, j) { 665 avkey.source_type = i + 1; 666 avkey.target_type = j + 1; 667 for (node = avtab_search_node(&policydb->te_avtab, 668 &avkey); 669 node; 670 node = avtab_search_node_next(node, avkey.specified)) { 671 if (node->key.specified == AVTAB_ALLOWED) 672 avd->allowed |= node->datum.u.data; 673 else if (node->key.specified == AVTAB_AUDITALLOW) 674 avd->auditallow |= node->datum.u.data; 675 else if (node->key.specified == AVTAB_AUDITDENY) 676 avd->auditdeny &= node->datum.u.data; 677 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 678 services_compute_xperms_drivers(xperms, node); 679 } 680 681 /* Check conditional av table for additional permissions */ 682 cond_compute_av(&policydb->te_cond_avtab, &avkey, 683 avd, xperms); 684 685 } 686 } 687 688 /* 689 * Remove any permissions prohibited by a constraint (this includes 690 * the MLS policy). 691 */ 692 constraint = tclass_datum->constraints; 693 while (constraint) { 694 if ((constraint->permissions & (avd->allowed)) && 695 !constraint_expr_eval(policydb, scontext, tcontext, NULL, 696 constraint->expr)) { 697 avd->allowed &= ~(constraint->permissions); 698 } 699 constraint = constraint->next; 700 } 701 702 /* 703 * If checking process transition permission and the 704 * role is changing, then check the (current_role, new_role) 705 * pair. 706 */ 707 if (tclass == policydb->process_class && 708 (avd->allowed & policydb->process_trans_perms) && 709 scontext->role != tcontext->role) { 710 for (ra = policydb->role_allow; ra; ra = ra->next) { 711 if (scontext->role == ra->role && 712 tcontext->role == ra->new_role) 713 break; 714 } 715 if (!ra) 716 avd->allowed &= ~policydb->process_trans_perms; 717 } 718 719 /* 720 * If the given source and target types have boundary 721 * constraint, lazy checks have to mask any violated 722 * permission and notice it to userspace via audit. 723 */ 724 type_attribute_bounds_av(policydb, scontext, tcontext, 725 tclass, avd); 726 } 727 728 static int security_validtrans_handle_fail(struct selinux_state *state, 729 struct context *ocontext, 730 struct context *ncontext, 731 struct context *tcontext, 732 u16 tclass) 733 { 734 struct policydb *p = &state->ss->policydb; 735 char *o = NULL, *n = NULL, *t = NULL; 736 u32 olen, nlen, tlen; 737 738 if (context_struct_to_string(p, ocontext, &o, &olen)) 739 goto out; 740 if (context_struct_to_string(p, ncontext, &n, &nlen)) 741 goto out; 742 if (context_struct_to_string(p, tcontext, &t, &tlen)) 743 goto out; 744 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 745 "op=security_validate_transition seresult=denied" 746 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 747 o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); 748 out: 749 kfree(o); 750 kfree(n); 751 kfree(t); 752 753 if (!enforcing_enabled(state)) 754 return 0; 755 return -EPERM; 756 } 757 758 static int security_compute_validatetrans(struct selinux_state *state, 759 u32 oldsid, u32 newsid, u32 tasksid, 760 u16 orig_tclass, bool user) 761 { 762 struct policydb *policydb; 763 struct sidtab *sidtab; 764 struct context *ocontext; 765 struct context *ncontext; 766 struct context *tcontext; 767 struct class_datum *tclass_datum; 768 struct constraint_node *constraint; 769 u16 tclass; 770 int rc = 0; 771 772 773 if (!state->initialized) 774 return 0; 775 776 read_lock(&state->ss->policy_rwlock); 777 778 policydb = &state->ss->policydb; 779 sidtab = &state->ss->sidtab; 780 781 if (!user) 782 tclass = unmap_class(&state->ss->map, orig_tclass); 783 else 784 tclass = orig_tclass; 785 786 if (!tclass || tclass > policydb->p_classes.nprim) { 787 rc = -EINVAL; 788 goto out; 789 } 790 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 791 792 ocontext = sidtab_search(sidtab, oldsid); 793 if (!ocontext) { 794 pr_err("SELinux: %s: unrecognized SID %d\n", 795 __func__, oldsid); 796 rc = -EINVAL; 797 goto out; 798 } 799 800 ncontext = sidtab_search(sidtab, newsid); 801 if (!ncontext) { 802 pr_err("SELinux: %s: unrecognized SID %d\n", 803 __func__, newsid); 804 rc = -EINVAL; 805 goto out; 806 } 807 808 tcontext = sidtab_search(sidtab, tasksid); 809 if (!tcontext) { 810 pr_err("SELinux: %s: unrecognized SID %d\n", 811 __func__, tasksid); 812 rc = -EINVAL; 813 goto out; 814 } 815 816 constraint = tclass_datum->validatetrans; 817 while (constraint) { 818 if (!constraint_expr_eval(policydb, ocontext, ncontext, 819 tcontext, constraint->expr)) { 820 if (user) 821 rc = -EPERM; 822 else 823 rc = security_validtrans_handle_fail(state, 824 ocontext, 825 ncontext, 826 tcontext, 827 tclass); 828 goto out; 829 } 830 constraint = constraint->next; 831 } 832 833 out: 834 read_unlock(&state->ss->policy_rwlock); 835 return rc; 836 } 837 838 int security_validate_transition_user(struct selinux_state *state, 839 u32 oldsid, u32 newsid, u32 tasksid, 840 u16 tclass) 841 { 842 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 843 tclass, true); 844 } 845 846 int security_validate_transition(struct selinux_state *state, 847 u32 oldsid, u32 newsid, u32 tasksid, 848 u16 orig_tclass) 849 { 850 return security_compute_validatetrans(state, oldsid, newsid, tasksid, 851 orig_tclass, false); 852 } 853 854 /* 855 * security_bounded_transition - check whether the given 856 * transition is directed to bounded, or not. 857 * It returns 0, if @newsid is bounded by @oldsid. 858 * Otherwise, it returns error code. 859 * 860 * @oldsid : current security identifier 861 * @newsid : destinated security identifier 862 */ 863 int security_bounded_transition(struct selinux_state *state, 864 u32 old_sid, u32 new_sid) 865 { 866 struct policydb *policydb; 867 struct sidtab *sidtab; 868 struct context *old_context, *new_context; 869 struct type_datum *type; 870 int index; 871 int rc; 872 873 if (!state->initialized) 874 return 0; 875 876 read_lock(&state->ss->policy_rwlock); 877 878 policydb = &state->ss->policydb; 879 sidtab = &state->ss->sidtab; 880 881 rc = -EINVAL; 882 old_context = sidtab_search(sidtab, old_sid); 883 if (!old_context) { 884 pr_err("SELinux: %s: unrecognized SID %u\n", 885 __func__, old_sid); 886 goto out; 887 } 888 889 rc = -EINVAL; 890 new_context = sidtab_search(sidtab, new_sid); 891 if (!new_context) { 892 pr_err("SELinux: %s: unrecognized SID %u\n", 893 __func__, new_sid); 894 goto out; 895 } 896 897 rc = 0; 898 /* type/domain unchanged */ 899 if (old_context->type == new_context->type) 900 goto out; 901 902 index = new_context->type; 903 while (true) { 904 type = flex_array_get_ptr(policydb->type_val_to_struct_array, 905 index - 1); 906 BUG_ON(!type); 907 908 /* not bounded anymore */ 909 rc = -EPERM; 910 if (!type->bounds) 911 break; 912 913 /* @newsid is bounded by @oldsid */ 914 rc = 0; 915 if (type->bounds == old_context->type) 916 break; 917 918 index = type->bounds; 919 } 920 921 if (rc) { 922 char *old_name = NULL; 923 char *new_name = NULL; 924 u32 length; 925 926 if (!context_struct_to_string(policydb, old_context, 927 &old_name, &length) && 928 !context_struct_to_string(policydb, new_context, 929 &new_name, &length)) { 930 audit_log(audit_context(), 931 GFP_ATOMIC, AUDIT_SELINUX_ERR, 932 "op=security_bounded_transition " 933 "seresult=denied " 934 "oldcontext=%s newcontext=%s", 935 old_name, new_name); 936 } 937 kfree(new_name); 938 kfree(old_name); 939 } 940 out: 941 read_unlock(&state->ss->policy_rwlock); 942 943 return rc; 944 } 945 946 static void avd_init(struct selinux_state *state, struct av_decision *avd) 947 { 948 avd->allowed = 0; 949 avd->auditallow = 0; 950 avd->auditdeny = 0xffffffff; 951 avd->seqno = state->ss->latest_granting; 952 avd->flags = 0; 953 } 954 955 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 956 struct avtab_node *node) 957 { 958 unsigned int i; 959 960 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 961 if (xpermd->driver != node->datum.u.xperms->driver) 962 return; 963 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 964 if (!security_xperm_test(node->datum.u.xperms->perms.p, 965 xpermd->driver)) 966 return; 967 } else { 968 BUG(); 969 } 970 971 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 972 xpermd->used |= XPERMS_ALLOWED; 973 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 974 memset(xpermd->allowed->p, 0xff, 975 sizeof(xpermd->allowed->p)); 976 } 977 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 978 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 979 xpermd->allowed->p[i] |= 980 node->datum.u.xperms->perms.p[i]; 981 } 982 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 983 xpermd->used |= XPERMS_AUDITALLOW; 984 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 985 memset(xpermd->auditallow->p, 0xff, 986 sizeof(xpermd->auditallow->p)); 987 } 988 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 989 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 990 xpermd->auditallow->p[i] |= 991 node->datum.u.xperms->perms.p[i]; 992 } 993 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 994 xpermd->used |= XPERMS_DONTAUDIT; 995 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 996 memset(xpermd->dontaudit->p, 0xff, 997 sizeof(xpermd->dontaudit->p)); 998 } 999 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 1000 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 1001 xpermd->dontaudit->p[i] |= 1002 node->datum.u.xperms->perms.p[i]; 1003 } 1004 } else { 1005 BUG(); 1006 } 1007 } 1008 1009 void security_compute_xperms_decision(struct selinux_state *state, 1010 u32 ssid, 1011 u32 tsid, 1012 u16 orig_tclass, 1013 u8 driver, 1014 struct extended_perms_decision *xpermd) 1015 { 1016 struct policydb *policydb; 1017 struct sidtab *sidtab; 1018 u16 tclass; 1019 struct context *scontext, *tcontext; 1020 struct avtab_key avkey; 1021 struct avtab_node *node; 1022 struct ebitmap *sattr, *tattr; 1023 struct ebitmap_node *snode, *tnode; 1024 unsigned int i, j; 1025 1026 xpermd->driver = driver; 1027 xpermd->used = 0; 1028 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1029 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1030 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1031 1032 read_lock(&state->ss->policy_rwlock); 1033 if (!state->initialized) 1034 goto allow; 1035 1036 policydb = &state->ss->policydb; 1037 sidtab = &state->ss->sidtab; 1038 1039 scontext = sidtab_search(sidtab, ssid); 1040 if (!scontext) { 1041 pr_err("SELinux: %s: unrecognized SID %d\n", 1042 __func__, ssid); 1043 goto out; 1044 } 1045 1046 tcontext = sidtab_search(sidtab, tsid); 1047 if (!tcontext) { 1048 pr_err("SELinux: %s: unrecognized SID %d\n", 1049 __func__, tsid); 1050 goto out; 1051 } 1052 1053 tclass = unmap_class(&state->ss->map, orig_tclass); 1054 if (unlikely(orig_tclass && !tclass)) { 1055 if (policydb->allow_unknown) 1056 goto allow; 1057 goto out; 1058 } 1059 1060 1061 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1062 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1063 goto out; 1064 } 1065 1066 avkey.target_class = tclass; 1067 avkey.specified = AVTAB_XPERMS; 1068 sattr = flex_array_get(policydb->type_attr_map_array, 1069 scontext->type - 1); 1070 BUG_ON(!sattr); 1071 tattr = flex_array_get(policydb->type_attr_map_array, 1072 tcontext->type - 1); 1073 BUG_ON(!tattr); 1074 ebitmap_for_each_positive_bit(sattr, snode, i) { 1075 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1076 avkey.source_type = i + 1; 1077 avkey.target_type = j + 1; 1078 for (node = avtab_search_node(&policydb->te_avtab, 1079 &avkey); 1080 node; 1081 node = avtab_search_node_next(node, avkey.specified)) 1082 services_compute_xperms_decision(xpermd, node); 1083 1084 cond_compute_xperms(&policydb->te_cond_avtab, 1085 &avkey, xpermd); 1086 } 1087 } 1088 out: 1089 read_unlock(&state->ss->policy_rwlock); 1090 return; 1091 allow: 1092 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1093 goto out; 1094 } 1095 1096 /** 1097 * security_compute_av - Compute access vector decisions. 1098 * @ssid: source security identifier 1099 * @tsid: target security identifier 1100 * @tclass: target security class 1101 * @avd: access vector decisions 1102 * @xperms: extended permissions 1103 * 1104 * Compute a set of access vector decisions based on the 1105 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1106 */ 1107 void security_compute_av(struct selinux_state *state, 1108 u32 ssid, 1109 u32 tsid, 1110 u16 orig_tclass, 1111 struct av_decision *avd, 1112 struct extended_perms *xperms) 1113 { 1114 struct policydb *policydb; 1115 struct sidtab *sidtab; 1116 u16 tclass; 1117 struct context *scontext = NULL, *tcontext = NULL; 1118 1119 read_lock(&state->ss->policy_rwlock); 1120 avd_init(state, avd); 1121 xperms->len = 0; 1122 if (!state->initialized) 1123 goto allow; 1124 1125 policydb = &state->ss->policydb; 1126 sidtab = &state->ss->sidtab; 1127 1128 scontext = sidtab_search(sidtab, ssid); 1129 if (!scontext) { 1130 pr_err("SELinux: %s: unrecognized SID %d\n", 1131 __func__, ssid); 1132 goto out; 1133 } 1134 1135 /* permissive domain? */ 1136 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1137 avd->flags |= AVD_FLAGS_PERMISSIVE; 1138 1139 tcontext = sidtab_search(sidtab, tsid); 1140 if (!tcontext) { 1141 pr_err("SELinux: %s: unrecognized SID %d\n", 1142 __func__, tsid); 1143 goto out; 1144 } 1145 1146 tclass = unmap_class(&state->ss->map, orig_tclass); 1147 if (unlikely(orig_tclass && !tclass)) { 1148 if (policydb->allow_unknown) 1149 goto allow; 1150 goto out; 1151 } 1152 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1153 xperms); 1154 map_decision(&state->ss->map, orig_tclass, avd, 1155 policydb->allow_unknown); 1156 out: 1157 read_unlock(&state->ss->policy_rwlock); 1158 return; 1159 allow: 1160 avd->allowed = 0xffffffff; 1161 goto out; 1162 } 1163 1164 void security_compute_av_user(struct selinux_state *state, 1165 u32 ssid, 1166 u32 tsid, 1167 u16 tclass, 1168 struct av_decision *avd) 1169 { 1170 struct policydb *policydb; 1171 struct sidtab *sidtab; 1172 struct context *scontext = NULL, *tcontext = NULL; 1173 1174 read_lock(&state->ss->policy_rwlock); 1175 avd_init(state, avd); 1176 if (!state->initialized) 1177 goto allow; 1178 1179 policydb = &state->ss->policydb; 1180 sidtab = &state->ss->sidtab; 1181 1182 scontext = sidtab_search(sidtab, ssid); 1183 if (!scontext) { 1184 pr_err("SELinux: %s: unrecognized SID %d\n", 1185 __func__, ssid); 1186 goto out; 1187 } 1188 1189 /* permissive domain? */ 1190 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1191 avd->flags |= AVD_FLAGS_PERMISSIVE; 1192 1193 tcontext = sidtab_search(sidtab, tsid); 1194 if (!tcontext) { 1195 pr_err("SELinux: %s: unrecognized SID %d\n", 1196 __func__, tsid); 1197 goto out; 1198 } 1199 1200 if (unlikely(!tclass)) { 1201 if (policydb->allow_unknown) 1202 goto allow; 1203 goto out; 1204 } 1205 1206 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1207 NULL); 1208 out: 1209 read_unlock(&state->ss->policy_rwlock); 1210 return; 1211 allow: 1212 avd->allowed = 0xffffffff; 1213 goto out; 1214 } 1215 1216 /* 1217 * Write the security context string representation of 1218 * the context structure `context' into a dynamically 1219 * allocated string of the correct size. Set `*scontext' 1220 * to point to this string and set `*scontext_len' to 1221 * the length of the string. 1222 */ 1223 static int context_struct_to_string(struct policydb *p, 1224 struct context *context, 1225 char **scontext, u32 *scontext_len) 1226 { 1227 char *scontextp; 1228 1229 if (scontext) 1230 *scontext = NULL; 1231 *scontext_len = 0; 1232 1233 if (context->len) { 1234 *scontext_len = context->len; 1235 if (scontext) { 1236 *scontext = kstrdup(context->str, GFP_ATOMIC); 1237 if (!(*scontext)) 1238 return -ENOMEM; 1239 } 1240 return 0; 1241 } 1242 1243 /* Compute the size of the context. */ 1244 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1245 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1246 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1247 *scontext_len += mls_compute_context_len(p, context); 1248 1249 if (!scontext) 1250 return 0; 1251 1252 /* Allocate space for the context; caller must free this space. */ 1253 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1254 if (!scontextp) 1255 return -ENOMEM; 1256 *scontext = scontextp; 1257 1258 /* 1259 * Copy the user name, role name and type name into the context. 1260 */ 1261 scontextp += sprintf(scontextp, "%s:%s:%s", 1262 sym_name(p, SYM_USERS, context->user - 1), 1263 sym_name(p, SYM_ROLES, context->role - 1), 1264 sym_name(p, SYM_TYPES, context->type - 1)); 1265 1266 mls_sid_to_context(p, context, &scontextp); 1267 1268 *scontextp = 0; 1269 1270 return 0; 1271 } 1272 1273 #include "initial_sid_to_string.h" 1274 1275 const char *security_get_initial_sid_context(u32 sid) 1276 { 1277 if (unlikely(sid > SECINITSID_NUM)) 1278 return NULL; 1279 return initial_sid_to_string[sid]; 1280 } 1281 1282 static int security_sid_to_context_core(struct selinux_state *state, 1283 u32 sid, char **scontext, 1284 u32 *scontext_len, int force) 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 rc = context_struct_to_string(policydb, context, scontext, 1330 scontext_len); 1331 out_unlock: 1332 read_unlock(&state->ss->policy_rwlock); 1333 out: 1334 return rc; 1335 1336 } 1337 1338 /** 1339 * security_sid_to_context - Obtain a context for a given SID. 1340 * @sid: security identifier, SID 1341 * @scontext: security context 1342 * @scontext_len: length in bytes 1343 * 1344 * Write the string representation of the context associated with @sid 1345 * into a dynamically allocated string of the correct size. Set @scontext 1346 * to point to this string and set @scontext_len to the length of the string. 1347 */ 1348 int security_sid_to_context(struct selinux_state *state, 1349 u32 sid, char **scontext, u32 *scontext_len) 1350 { 1351 return security_sid_to_context_core(state, sid, scontext, 1352 scontext_len, 0); 1353 } 1354 1355 int security_sid_to_context_force(struct selinux_state *state, u32 sid, 1356 char **scontext, u32 *scontext_len) 1357 { 1358 return security_sid_to_context_core(state, sid, scontext, 1359 scontext_len, 1); 1360 } 1361 1362 /* 1363 * Caveat: Mutates scontext. 1364 */ 1365 static int string_to_context_struct(struct policydb *pol, 1366 struct sidtab *sidtabp, 1367 char *scontext, 1368 u32 scontext_len, 1369 struct context *ctx, 1370 u32 def_sid) 1371 { 1372 struct role_datum *role; 1373 struct type_datum *typdatum; 1374 struct user_datum *usrdatum; 1375 char *scontextp, *p, oldc; 1376 int rc = 0; 1377 1378 context_init(ctx); 1379 1380 /* Parse the security context. */ 1381 1382 rc = -EINVAL; 1383 scontextp = (char *) scontext; 1384 1385 /* Extract the user. */ 1386 p = scontextp; 1387 while (*p && *p != ':') 1388 p++; 1389 1390 if (*p == 0) 1391 goto out; 1392 1393 *p++ = 0; 1394 1395 usrdatum = hashtab_search(pol->p_users.table, scontextp); 1396 if (!usrdatum) 1397 goto out; 1398 1399 ctx->user = usrdatum->value; 1400 1401 /* Extract role. */ 1402 scontextp = p; 1403 while (*p && *p != ':') 1404 p++; 1405 1406 if (*p == 0) 1407 goto out; 1408 1409 *p++ = 0; 1410 1411 role = hashtab_search(pol->p_roles.table, scontextp); 1412 if (!role) 1413 goto out; 1414 ctx->role = role->value; 1415 1416 /* Extract type. */ 1417 scontextp = p; 1418 while (*p && *p != ':') 1419 p++; 1420 oldc = *p; 1421 *p++ = 0; 1422 1423 typdatum = hashtab_search(pol->p_types.table, scontextp); 1424 if (!typdatum || typdatum->attribute) 1425 goto out; 1426 1427 ctx->type = typdatum->value; 1428 1429 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid); 1430 if (rc) 1431 goto out; 1432 1433 rc = -EINVAL; 1434 if ((p - scontext) < scontext_len) 1435 goto out; 1436 1437 /* Check the validity of the new context. */ 1438 if (!policydb_context_isvalid(pol, ctx)) 1439 goto out; 1440 rc = 0; 1441 out: 1442 if (rc) 1443 context_destroy(ctx); 1444 return rc; 1445 } 1446 1447 static int security_context_to_sid_core(struct selinux_state *state, 1448 const char *scontext, u32 scontext_len, 1449 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1450 int force) 1451 { 1452 struct policydb *policydb; 1453 struct sidtab *sidtab; 1454 char *scontext2, *str = NULL; 1455 struct context context; 1456 int rc = 0; 1457 1458 /* An empty security context is never valid. */ 1459 if (!scontext_len) 1460 return -EINVAL; 1461 1462 /* Copy the string to allow changes and ensure a NUL terminator */ 1463 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1464 if (!scontext2) 1465 return -ENOMEM; 1466 1467 if (!state->initialized) { 1468 int i; 1469 1470 for (i = 1; i < SECINITSID_NUM; i++) { 1471 if (!strcmp(initial_sid_to_string[i], scontext2)) { 1472 *sid = i; 1473 goto out; 1474 } 1475 } 1476 *sid = SECINITSID_KERNEL; 1477 goto out; 1478 } 1479 *sid = SECSID_NULL; 1480 1481 if (force) { 1482 /* Save another copy for storing in uninterpreted form */ 1483 rc = -ENOMEM; 1484 str = kstrdup(scontext2, gfp_flags); 1485 if (!str) 1486 goto out; 1487 } 1488 read_lock(&state->ss->policy_rwlock); 1489 policydb = &state->ss->policydb; 1490 sidtab = &state->ss->sidtab; 1491 rc = string_to_context_struct(policydb, sidtab, scontext2, 1492 scontext_len, &context, def_sid); 1493 if (rc == -EINVAL && force) { 1494 context.str = str; 1495 context.len = strlen(str) + 1; 1496 str = NULL; 1497 } else if (rc) 1498 goto out_unlock; 1499 rc = sidtab_context_to_sid(sidtab, &context, sid); 1500 context_destroy(&context); 1501 out_unlock: 1502 read_unlock(&state->ss->policy_rwlock); 1503 out: 1504 kfree(scontext2); 1505 kfree(str); 1506 return rc; 1507 } 1508 1509 /** 1510 * security_context_to_sid - Obtain a SID for a given security context. 1511 * @scontext: security context 1512 * @scontext_len: length in bytes 1513 * @sid: security identifier, SID 1514 * @gfp: context for the allocation 1515 * 1516 * Obtains a SID associated with the security context that 1517 * has the string representation specified by @scontext. 1518 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1519 * memory is available, or 0 on success. 1520 */ 1521 int security_context_to_sid(struct selinux_state *state, 1522 const char *scontext, u32 scontext_len, u32 *sid, 1523 gfp_t gfp) 1524 { 1525 return security_context_to_sid_core(state, scontext, scontext_len, 1526 sid, SECSID_NULL, gfp, 0); 1527 } 1528 1529 int security_context_str_to_sid(struct selinux_state *state, 1530 const char *scontext, u32 *sid, gfp_t gfp) 1531 { 1532 return security_context_to_sid(state, scontext, strlen(scontext), 1533 sid, gfp); 1534 } 1535 1536 /** 1537 * security_context_to_sid_default - Obtain a SID for a given security context, 1538 * falling back to specified default if needed. 1539 * 1540 * @scontext: security context 1541 * @scontext_len: length in bytes 1542 * @sid: security identifier, SID 1543 * @def_sid: default SID to assign on error 1544 * 1545 * Obtains a SID associated with the security context that 1546 * has the string representation specified by @scontext. 1547 * The default SID is passed to the MLS layer to be used to allow 1548 * kernel labeling of the MLS field if the MLS field is not present 1549 * (for upgrading to MLS without full relabel). 1550 * Implicitly forces adding of the context even if it cannot be mapped yet. 1551 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1552 * memory is available, or 0 on success. 1553 */ 1554 int security_context_to_sid_default(struct selinux_state *state, 1555 const char *scontext, u32 scontext_len, 1556 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1557 { 1558 return security_context_to_sid_core(state, scontext, scontext_len, 1559 sid, def_sid, gfp_flags, 1); 1560 } 1561 1562 int security_context_to_sid_force(struct selinux_state *state, 1563 const char *scontext, u32 scontext_len, 1564 u32 *sid) 1565 { 1566 return security_context_to_sid_core(state, scontext, scontext_len, 1567 sid, SECSID_NULL, GFP_KERNEL, 1); 1568 } 1569 1570 static int compute_sid_handle_invalid_context( 1571 struct selinux_state *state, 1572 struct context *scontext, 1573 struct context *tcontext, 1574 u16 tclass, 1575 struct context *newcontext) 1576 { 1577 struct policydb *policydb = &state->ss->policydb; 1578 char *s = NULL, *t = NULL, *n = NULL; 1579 u32 slen, tlen, nlen; 1580 1581 if (context_struct_to_string(policydb, scontext, &s, &slen)) 1582 goto out; 1583 if (context_struct_to_string(policydb, tcontext, &t, &tlen)) 1584 goto out; 1585 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1586 goto out; 1587 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 1588 "op=security_compute_sid invalid_context=%s" 1589 " scontext=%s" 1590 " tcontext=%s" 1591 " tclass=%s", 1592 n, s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1593 out: 1594 kfree(s); 1595 kfree(t); 1596 kfree(n); 1597 if (!enforcing_enabled(state)) 1598 return 0; 1599 return -EACCES; 1600 } 1601 1602 static void filename_compute_type(struct policydb *policydb, 1603 struct context *newcontext, 1604 u32 stype, u32 ttype, u16 tclass, 1605 const char *objname) 1606 { 1607 struct filename_trans ft; 1608 struct filename_trans_datum *otype; 1609 1610 /* 1611 * Most filename trans rules are going to live in specific directories 1612 * like /dev or /var/run. This bitmap will quickly skip rule searches 1613 * if the ttype does not contain any rules. 1614 */ 1615 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1616 return; 1617 1618 ft.stype = stype; 1619 ft.ttype = ttype; 1620 ft.tclass = tclass; 1621 ft.name = objname; 1622 1623 otype = hashtab_search(policydb->filename_trans, &ft); 1624 if (otype) 1625 newcontext->type = otype->otype; 1626 } 1627 1628 static int security_compute_sid(struct selinux_state *state, 1629 u32 ssid, 1630 u32 tsid, 1631 u16 orig_tclass, 1632 u32 specified, 1633 const char *objname, 1634 u32 *out_sid, 1635 bool kern) 1636 { 1637 struct policydb *policydb; 1638 struct sidtab *sidtab; 1639 struct class_datum *cladatum = NULL; 1640 struct context *scontext = NULL, *tcontext = NULL, newcontext; 1641 struct role_trans *roletr = NULL; 1642 struct avtab_key avkey; 1643 struct avtab_datum *avdatum; 1644 struct avtab_node *node; 1645 u16 tclass; 1646 int rc = 0; 1647 bool sock; 1648 1649 if (!state->initialized) { 1650 switch (orig_tclass) { 1651 case SECCLASS_PROCESS: /* kernel value */ 1652 *out_sid = ssid; 1653 break; 1654 default: 1655 *out_sid = tsid; 1656 break; 1657 } 1658 goto out; 1659 } 1660 1661 context_init(&newcontext); 1662 1663 read_lock(&state->ss->policy_rwlock); 1664 1665 if (kern) { 1666 tclass = unmap_class(&state->ss->map, orig_tclass); 1667 sock = security_is_socket_class(orig_tclass); 1668 } else { 1669 tclass = orig_tclass; 1670 sock = security_is_socket_class(map_class(&state->ss->map, 1671 tclass)); 1672 } 1673 1674 policydb = &state->ss->policydb; 1675 sidtab = &state->ss->sidtab; 1676 1677 scontext = sidtab_search(sidtab, ssid); 1678 if (!scontext) { 1679 pr_err("SELinux: %s: unrecognized SID %d\n", 1680 __func__, ssid); 1681 rc = -EINVAL; 1682 goto out_unlock; 1683 } 1684 tcontext = sidtab_search(sidtab, tsid); 1685 if (!tcontext) { 1686 pr_err("SELinux: %s: unrecognized SID %d\n", 1687 __func__, tsid); 1688 rc = -EINVAL; 1689 goto out_unlock; 1690 } 1691 1692 if (tclass && tclass <= policydb->p_classes.nprim) 1693 cladatum = policydb->class_val_to_struct[tclass - 1]; 1694 1695 /* Set the user identity. */ 1696 switch (specified) { 1697 case AVTAB_TRANSITION: 1698 case AVTAB_CHANGE: 1699 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1700 newcontext.user = tcontext->user; 1701 } else { 1702 /* notice this gets both DEFAULT_SOURCE and unset */ 1703 /* Use the process user identity. */ 1704 newcontext.user = scontext->user; 1705 } 1706 break; 1707 case AVTAB_MEMBER: 1708 /* Use the related object owner. */ 1709 newcontext.user = tcontext->user; 1710 break; 1711 } 1712 1713 /* Set the role to default values. */ 1714 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1715 newcontext.role = scontext->role; 1716 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1717 newcontext.role = tcontext->role; 1718 } else { 1719 if ((tclass == policydb->process_class) || (sock == true)) 1720 newcontext.role = scontext->role; 1721 else 1722 newcontext.role = OBJECT_R_VAL; 1723 } 1724 1725 /* Set the type to default values. */ 1726 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1727 newcontext.type = scontext->type; 1728 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1729 newcontext.type = tcontext->type; 1730 } else { 1731 if ((tclass == policydb->process_class) || (sock == true)) { 1732 /* Use the type of process. */ 1733 newcontext.type = scontext->type; 1734 } else { 1735 /* Use the type of the related object. */ 1736 newcontext.type = tcontext->type; 1737 } 1738 } 1739 1740 /* Look for a type transition/member/change rule. */ 1741 avkey.source_type = scontext->type; 1742 avkey.target_type = tcontext->type; 1743 avkey.target_class = tclass; 1744 avkey.specified = specified; 1745 avdatum = avtab_search(&policydb->te_avtab, &avkey); 1746 1747 /* If no permanent rule, also check for enabled conditional rules */ 1748 if (!avdatum) { 1749 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1750 for (; node; node = avtab_search_node_next(node, specified)) { 1751 if (node->key.specified & AVTAB_ENABLED) { 1752 avdatum = &node->datum; 1753 break; 1754 } 1755 } 1756 } 1757 1758 if (avdatum) { 1759 /* Use the type from the type transition/member/change rule. */ 1760 newcontext.type = avdatum->u.data; 1761 } 1762 1763 /* if we have a objname this is a file trans check so check those rules */ 1764 if (objname) 1765 filename_compute_type(policydb, &newcontext, scontext->type, 1766 tcontext->type, tclass, objname); 1767 1768 /* Check for class-specific changes. */ 1769 if (specified & AVTAB_TRANSITION) { 1770 /* Look for a role transition rule. */ 1771 for (roletr = policydb->role_tr; roletr; 1772 roletr = roletr->next) { 1773 if ((roletr->role == scontext->role) && 1774 (roletr->type == tcontext->type) && 1775 (roletr->tclass == tclass)) { 1776 /* Use the role transition rule. */ 1777 newcontext.role = roletr->new_role; 1778 break; 1779 } 1780 } 1781 } 1782 1783 /* Set the MLS attributes. 1784 This is done last because it may allocate memory. */ 1785 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1786 &newcontext, sock); 1787 if (rc) 1788 goto out_unlock; 1789 1790 /* Check the validity of the context. */ 1791 if (!policydb_context_isvalid(policydb, &newcontext)) { 1792 rc = compute_sid_handle_invalid_context(state, scontext, 1793 tcontext, 1794 tclass, 1795 &newcontext); 1796 if (rc) 1797 goto out_unlock; 1798 } 1799 /* Obtain the sid for the context. */ 1800 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1801 out_unlock: 1802 read_unlock(&state->ss->policy_rwlock); 1803 context_destroy(&newcontext); 1804 out: 1805 return rc; 1806 } 1807 1808 /** 1809 * security_transition_sid - Compute the SID for a new subject/object. 1810 * @ssid: source security identifier 1811 * @tsid: target security identifier 1812 * @tclass: target security class 1813 * @out_sid: security identifier for new subject/object 1814 * 1815 * Compute a SID to use for labeling a new subject or object in the 1816 * class @tclass based on a SID pair (@ssid, @tsid). 1817 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1818 * if insufficient memory is available, or %0 if the new SID was 1819 * computed successfully. 1820 */ 1821 int security_transition_sid(struct selinux_state *state, 1822 u32 ssid, u32 tsid, u16 tclass, 1823 const struct qstr *qstr, u32 *out_sid) 1824 { 1825 return security_compute_sid(state, ssid, tsid, tclass, 1826 AVTAB_TRANSITION, 1827 qstr ? qstr->name : NULL, out_sid, true); 1828 } 1829 1830 int security_transition_sid_user(struct selinux_state *state, 1831 u32 ssid, u32 tsid, u16 tclass, 1832 const char *objname, u32 *out_sid) 1833 { 1834 return security_compute_sid(state, ssid, tsid, tclass, 1835 AVTAB_TRANSITION, 1836 objname, out_sid, false); 1837 } 1838 1839 /** 1840 * security_member_sid - Compute the SID for member selection. 1841 * @ssid: source security identifier 1842 * @tsid: target security identifier 1843 * @tclass: target security class 1844 * @out_sid: security identifier for selected member 1845 * 1846 * Compute a SID to use when selecting a member of a polyinstantiated 1847 * object of class @tclass based on a SID pair (@ssid, @tsid). 1848 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1849 * if insufficient memory is available, or %0 if the SID was 1850 * computed successfully. 1851 */ 1852 int security_member_sid(struct selinux_state *state, 1853 u32 ssid, 1854 u32 tsid, 1855 u16 tclass, 1856 u32 *out_sid) 1857 { 1858 return security_compute_sid(state, ssid, tsid, tclass, 1859 AVTAB_MEMBER, NULL, 1860 out_sid, false); 1861 } 1862 1863 /** 1864 * security_change_sid - Compute the SID for object relabeling. 1865 * @ssid: source security identifier 1866 * @tsid: target security identifier 1867 * @tclass: target security class 1868 * @out_sid: security identifier for selected member 1869 * 1870 * Compute a SID to use for relabeling an object of class @tclass 1871 * based on a SID pair (@ssid, @tsid). 1872 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1873 * if insufficient memory is available, or %0 if the SID was 1874 * computed successfully. 1875 */ 1876 int security_change_sid(struct selinux_state *state, 1877 u32 ssid, 1878 u32 tsid, 1879 u16 tclass, 1880 u32 *out_sid) 1881 { 1882 return security_compute_sid(state, 1883 ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1884 out_sid, false); 1885 } 1886 1887 /* Clone the SID into the new SID table. */ 1888 static int clone_sid(u32 sid, 1889 struct context *context, 1890 void *arg) 1891 { 1892 struct sidtab *s = arg; 1893 1894 if (sid > SECINITSID_NUM) 1895 return sidtab_insert(s, sid, context); 1896 else 1897 return 0; 1898 } 1899 1900 static inline int convert_context_handle_invalid_context( 1901 struct selinux_state *state, 1902 struct context *context) 1903 { 1904 struct policydb *policydb = &state->ss->policydb; 1905 char *s; 1906 u32 len; 1907 1908 if (enforcing_enabled(state)) 1909 return -EINVAL; 1910 1911 if (!context_struct_to_string(policydb, context, &s, &len)) { 1912 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 1913 s); 1914 kfree(s); 1915 } 1916 return 0; 1917 } 1918 1919 struct convert_context_args { 1920 struct selinux_state *state; 1921 struct policydb *oldp; 1922 struct policydb *newp; 1923 }; 1924 1925 /* 1926 * Convert the values in the security context 1927 * structure `c' from the values specified 1928 * in the policy `p->oldp' to the values specified 1929 * in the policy `p->newp'. Verify that the 1930 * context is valid under the new policy. 1931 */ 1932 static int convert_context(u32 key, 1933 struct context *c, 1934 void *p) 1935 { 1936 struct convert_context_args *args; 1937 struct context oldc; 1938 struct ocontext *oc; 1939 struct mls_range *range; 1940 struct role_datum *role; 1941 struct type_datum *typdatum; 1942 struct user_datum *usrdatum; 1943 char *s; 1944 u32 len; 1945 int rc = 0; 1946 1947 if (key <= SECINITSID_NUM) 1948 goto out; 1949 1950 args = p; 1951 1952 if (c->str) { 1953 struct context ctx; 1954 1955 rc = -ENOMEM; 1956 s = kstrdup(c->str, GFP_KERNEL); 1957 if (!s) 1958 goto out; 1959 1960 rc = string_to_context_struct(args->newp, NULL, s, 1961 c->len, &ctx, SECSID_NULL); 1962 kfree(s); 1963 if (!rc) { 1964 pr_info("SELinux: Context %s became valid (mapped).\n", 1965 c->str); 1966 /* Replace string with mapped representation. */ 1967 kfree(c->str); 1968 memcpy(c, &ctx, sizeof(*c)); 1969 goto out; 1970 } else if (rc == -EINVAL) { 1971 /* Retain string representation for later mapping. */ 1972 rc = 0; 1973 goto out; 1974 } else { 1975 /* Other error condition, e.g. ENOMEM. */ 1976 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 1977 c->str, -rc); 1978 goto out; 1979 } 1980 } 1981 1982 rc = context_cpy(&oldc, c); 1983 if (rc) 1984 goto out; 1985 1986 /* Convert the user. */ 1987 rc = -EINVAL; 1988 usrdatum = hashtab_search(args->newp->p_users.table, 1989 sym_name(args->oldp, SYM_USERS, c->user - 1)); 1990 if (!usrdatum) 1991 goto bad; 1992 c->user = usrdatum->value; 1993 1994 /* Convert the role. */ 1995 rc = -EINVAL; 1996 role = hashtab_search(args->newp->p_roles.table, 1997 sym_name(args->oldp, SYM_ROLES, c->role - 1)); 1998 if (!role) 1999 goto bad; 2000 c->role = role->value; 2001 2002 /* Convert the type. */ 2003 rc = -EINVAL; 2004 typdatum = hashtab_search(args->newp->p_types.table, 2005 sym_name(args->oldp, SYM_TYPES, c->type - 1)); 2006 if (!typdatum) 2007 goto bad; 2008 c->type = typdatum->value; 2009 2010 /* Convert the MLS fields if dealing with MLS policies */ 2011 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2012 rc = mls_convert_context(args->oldp, args->newp, c); 2013 if (rc) 2014 goto bad; 2015 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) { 2016 /* 2017 * Switching between MLS and non-MLS policy: 2018 * free any storage used by the MLS fields in the 2019 * context for all existing entries in the sidtab. 2020 */ 2021 mls_context_destroy(c); 2022 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2023 /* 2024 * Switching between non-MLS and MLS policy: 2025 * ensure that the MLS fields of the context for all 2026 * existing entries in the sidtab are filled in with a 2027 * suitable default value, likely taken from one of the 2028 * initial SIDs. 2029 */ 2030 oc = args->newp->ocontexts[OCON_ISID]; 2031 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2032 oc = oc->next; 2033 rc = -EINVAL; 2034 if (!oc) { 2035 pr_err("SELinux: unable to look up" 2036 " the initial SIDs list\n"); 2037 goto bad; 2038 } 2039 range = &oc->context[0].range; 2040 rc = mls_range_set(c, range); 2041 if (rc) 2042 goto bad; 2043 } 2044 2045 /* Check the validity of the new context. */ 2046 if (!policydb_context_isvalid(args->newp, c)) { 2047 rc = convert_context_handle_invalid_context(args->state, 2048 &oldc); 2049 if (rc) 2050 goto bad; 2051 } 2052 2053 context_destroy(&oldc); 2054 2055 rc = 0; 2056 out: 2057 return rc; 2058 bad: 2059 /* Map old representation to string and save it. */ 2060 rc = context_struct_to_string(args->oldp, &oldc, &s, &len); 2061 if (rc) 2062 return rc; 2063 context_destroy(&oldc); 2064 context_destroy(c); 2065 c->str = s; 2066 c->len = len; 2067 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2068 c->str); 2069 rc = 0; 2070 goto out; 2071 } 2072 2073 static void security_load_policycaps(struct selinux_state *state) 2074 { 2075 struct policydb *p = &state->ss->policydb; 2076 unsigned int i; 2077 struct ebitmap_node *node; 2078 2079 for (i = 0; i < ARRAY_SIZE(state->policycap); i++) 2080 state->policycap[i] = ebitmap_get_bit(&p->policycaps, i); 2081 2082 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2083 pr_info("SELinux: policy capability %s=%d\n", 2084 selinux_policycap_names[i], 2085 ebitmap_get_bit(&p->policycaps, i)); 2086 2087 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2088 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2089 pr_info("SELinux: unknown policy capability %u\n", 2090 i); 2091 } 2092 } 2093 2094 static int security_preserve_bools(struct selinux_state *state, 2095 struct policydb *newpolicydb); 2096 2097 /** 2098 * security_load_policy - Load a security policy configuration. 2099 * @data: binary policy data 2100 * @len: length of data in bytes 2101 * 2102 * Load a new set of security policy configuration data, 2103 * validate it and convert the SID table as necessary. 2104 * This function will flush the access vector cache after 2105 * loading the new policy. 2106 */ 2107 int security_load_policy(struct selinux_state *state, void *data, size_t len) 2108 { 2109 struct policydb *policydb; 2110 struct sidtab *sidtab; 2111 struct policydb *oldpolicydb, *newpolicydb; 2112 struct sidtab oldsidtab, newsidtab; 2113 struct selinux_mapping *oldmapping; 2114 struct selinux_map newmap; 2115 struct convert_context_args args; 2116 u32 seqno; 2117 int rc = 0; 2118 struct policy_file file = { data, len }, *fp = &file; 2119 2120 oldpolicydb = kcalloc(2, sizeof(*oldpolicydb), GFP_KERNEL); 2121 if (!oldpolicydb) { 2122 rc = -ENOMEM; 2123 goto out; 2124 } 2125 newpolicydb = oldpolicydb + 1; 2126 2127 policydb = &state->ss->policydb; 2128 sidtab = &state->ss->sidtab; 2129 2130 if (!state->initialized) { 2131 rc = policydb_read(policydb, fp); 2132 if (rc) 2133 goto out; 2134 2135 policydb->len = len; 2136 rc = selinux_set_mapping(policydb, secclass_map, 2137 &state->ss->map); 2138 if (rc) { 2139 policydb_destroy(policydb); 2140 goto out; 2141 } 2142 2143 rc = policydb_load_isids(policydb, sidtab); 2144 if (rc) { 2145 policydb_destroy(policydb); 2146 goto out; 2147 } 2148 2149 security_load_policycaps(state); 2150 state->initialized = 1; 2151 seqno = ++state->ss->latest_granting; 2152 selinux_complete_init(); 2153 avc_ss_reset(state->avc, seqno); 2154 selnl_notify_policyload(seqno); 2155 selinux_status_update_policyload(state, seqno); 2156 selinux_netlbl_cache_invalidate(); 2157 selinux_xfrm_notify_policyload(); 2158 goto out; 2159 } 2160 2161 #if 0 2162 sidtab_hash_eval(sidtab, "sids"); 2163 #endif 2164 2165 rc = policydb_read(newpolicydb, fp); 2166 if (rc) 2167 goto out; 2168 2169 newpolicydb->len = len; 2170 /* If switching between different policy types, log MLS status */ 2171 if (policydb->mls_enabled && !newpolicydb->mls_enabled) 2172 pr_info("SELinux: Disabling MLS support...\n"); 2173 else if (!policydb->mls_enabled && newpolicydb->mls_enabled) 2174 pr_info("SELinux: Enabling MLS support...\n"); 2175 2176 rc = policydb_load_isids(newpolicydb, &newsidtab); 2177 if (rc) { 2178 pr_err("SELinux: unable to load the initial SIDs\n"); 2179 policydb_destroy(newpolicydb); 2180 goto out; 2181 } 2182 2183 rc = selinux_set_mapping(newpolicydb, secclass_map, &newmap); 2184 if (rc) 2185 goto err; 2186 2187 rc = security_preserve_bools(state, newpolicydb); 2188 if (rc) { 2189 pr_err("SELinux: unable to preserve booleans\n"); 2190 goto err; 2191 } 2192 2193 /* Clone the SID table. */ 2194 sidtab_shutdown(sidtab); 2195 2196 rc = sidtab_map(sidtab, clone_sid, &newsidtab); 2197 if (rc) 2198 goto err; 2199 2200 /* 2201 * Convert the internal representations of contexts 2202 * in the new SID table. 2203 */ 2204 args.state = state; 2205 args.oldp = policydb; 2206 args.newp = newpolicydb; 2207 rc = sidtab_map(&newsidtab, convert_context, &args); 2208 if (rc) { 2209 pr_err("SELinux: unable to convert the internal" 2210 " representation of contexts in the new SID" 2211 " table\n"); 2212 goto err; 2213 } 2214 2215 /* Save the old policydb and SID table to free later. */ 2216 memcpy(oldpolicydb, policydb, sizeof(*policydb)); 2217 sidtab_set(&oldsidtab, sidtab); 2218 2219 /* Install the new policydb and SID table. */ 2220 write_lock_irq(&state->ss->policy_rwlock); 2221 memcpy(policydb, newpolicydb, sizeof(*policydb)); 2222 sidtab_set(sidtab, &newsidtab); 2223 security_load_policycaps(state); 2224 oldmapping = state->ss->map.mapping; 2225 state->ss->map.mapping = newmap.mapping; 2226 state->ss->map.size = newmap.size; 2227 seqno = ++state->ss->latest_granting; 2228 write_unlock_irq(&state->ss->policy_rwlock); 2229 2230 /* Free the old policydb and SID table. */ 2231 policydb_destroy(oldpolicydb); 2232 sidtab_destroy(&oldsidtab); 2233 kfree(oldmapping); 2234 2235 avc_ss_reset(state->avc, seqno); 2236 selnl_notify_policyload(seqno); 2237 selinux_status_update_policyload(state, seqno); 2238 selinux_netlbl_cache_invalidate(); 2239 selinux_xfrm_notify_policyload(); 2240 2241 rc = 0; 2242 goto out; 2243 2244 err: 2245 kfree(newmap.mapping); 2246 sidtab_destroy(&newsidtab); 2247 policydb_destroy(newpolicydb); 2248 2249 out: 2250 kfree(oldpolicydb); 2251 return rc; 2252 } 2253 2254 size_t security_policydb_len(struct selinux_state *state) 2255 { 2256 struct policydb *p = &state->ss->policydb; 2257 size_t len; 2258 2259 read_lock(&state->ss->policy_rwlock); 2260 len = p->len; 2261 read_unlock(&state->ss->policy_rwlock); 2262 2263 return len; 2264 } 2265 2266 /** 2267 * security_port_sid - Obtain the SID for a port. 2268 * @protocol: protocol number 2269 * @port: port number 2270 * @out_sid: security identifier 2271 */ 2272 int security_port_sid(struct selinux_state *state, 2273 u8 protocol, u16 port, u32 *out_sid) 2274 { 2275 struct policydb *policydb; 2276 struct sidtab *sidtab; 2277 struct ocontext *c; 2278 int rc = 0; 2279 2280 read_lock(&state->ss->policy_rwlock); 2281 2282 policydb = &state->ss->policydb; 2283 sidtab = &state->ss->sidtab; 2284 2285 c = policydb->ocontexts[OCON_PORT]; 2286 while (c) { 2287 if (c->u.port.protocol == protocol && 2288 c->u.port.low_port <= port && 2289 c->u.port.high_port >= port) 2290 break; 2291 c = c->next; 2292 } 2293 2294 if (c) { 2295 if (!c->sid[0]) { 2296 rc = sidtab_context_to_sid(sidtab, 2297 &c->context[0], 2298 &c->sid[0]); 2299 if (rc) 2300 goto out; 2301 } 2302 *out_sid = c->sid[0]; 2303 } else { 2304 *out_sid = SECINITSID_PORT; 2305 } 2306 2307 out: 2308 read_unlock(&state->ss->policy_rwlock); 2309 return rc; 2310 } 2311 2312 /** 2313 * security_pkey_sid - Obtain the SID for a pkey. 2314 * @subnet_prefix: Subnet Prefix 2315 * @pkey_num: pkey number 2316 * @out_sid: security identifier 2317 */ 2318 int security_ib_pkey_sid(struct selinux_state *state, 2319 u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2320 { 2321 struct policydb *policydb; 2322 struct sidtab *sidtab; 2323 struct ocontext *c; 2324 int rc = 0; 2325 2326 read_lock(&state->ss->policy_rwlock); 2327 2328 policydb = &state->ss->policydb; 2329 sidtab = &state->ss->sidtab; 2330 2331 c = policydb->ocontexts[OCON_IBPKEY]; 2332 while (c) { 2333 if (c->u.ibpkey.low_pkey <= pkey_num && 2334 c->u.ibpkey.high_pkey >= pkey_num && 2335 c->u.ibpkey.subnet_prefix == subnet_prefix) 2336 break; 2337 2338 c = c->next; 2339 } 2340 2341 if (c) { 2342 if (!c->sid[0]) { 2343 rc = sidtab_context_to_sid(sidtab, 2344 &c->context[0], 2345 &c->sid[0]); 2346 if (rc) 2347 goto out; 2348 } 2349 *out_sid = c->sid[0]; 2350 } else 2351 *out_sid = SECINITSID_UNLABELED; 2352 2353 out: 2354 read_unlock(&state->ss->policy_rwlock); 2355 return rc; 2356 } 2357 2358 /** 2359 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2360 * @dev_name: device name 2361 * @port: port number 2362 * @out_sid: security identifier 2363 */ 2364 int security_ib_endport_sid(struct selinux_state *state, 2365 const char *dev_name, u8 port_num, u32 *out_sid) 2366 { 2367 struct policydb *policydb; 2368 struct sidtab *sidtab; 2369 struct ocontext *c; 2370 int rc = 0; 2371 2372 read_lock(&state->ss->policy_rwlock); 2373 2374 policydb = &state->ss->policydb; 2375 sidtab = &state->ss->sidtab; 2376 2377 c = policydb->ocontexts[OCON_IBENDPORT]; 2378 while (c) { 2379 if (c->u.ibendport.port == port_num && 2380 !strncmp(c->u.ibendport.dev_name, 2381 dev_name, 2382 IB_DEVICE_NAME_MAX)) 2383 break; 2384 2385 c = c->next; 2386 } 2387 2388 if (c) { 2389 if (!c->sid[0]) { 2390 rc = sidtab_context_to_sid(sidtab, 2391 &c->context[0], 2392 &c->sid[0]); 2393 if (rc) 2394 goto out; 2395 } 2396 *out_sid = c->sid[0]; 2397 } else 2398 *out_sid = SECINITSID_UNLABELED; 2399 2400 out: 2401 read_unlock(&state->ss->policy_rwlock); 2402 return rc; 2403 } 2404 2405 /** 2406 * security_netif_sid - Obtain the SID for a network interface. 2407 * @name: interface name 2408 * @if_sid: interface SID 2409 */ 2410 int security_netif_sid(struct selinux_state *state, 2411 char *name, u32 *if_sid) 2412 { 2413 struct policydb *policydb; 2414 struct sidtab *sidtab; 2415 int rc = 0; 2416 struct ocontext *c; 2417 2418 read_lock(&state->ss->policy_rwlock); 2419 2420 policydb = &state->ss->policydb; 2421 sidtab = &state->ss->sidtab; 2422 2423 c = policydb->ocontexts[OCON_NETIF]; 2424 while (c) { 2425 if (strcmp(name, c->u.name) == 0) 2426 break; 2427 c = c->next; 2428 } 2429 2430 if (c) { 2431 if (!c->sid[0] || !c->sid[1]) { 2432 rc = sidtab_context_to_sid(sidtab, 2433 &c->context[0], 2434 &c->sid[0]); 2435 if (rc) 2436 goto out; 2437 rc = sidtab_context_to_sid(sidtab, 2438 &c->context[1], 2439 &c->sid[1]); 2440 if (rc) 2441 goto out; 2442 } 2443 *if_sid = c->sid[0]; 2444 } else 2445 *if_sid = SECINITSID_NETIF; 2446 2447 out: 2448 read_unlock(&state->ss->policy_rwlock); 2449 return rc; 2450 } 2451 2452 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2453 { 2454 int i, fail = 0; 2455 2456 for (i = 0; i < 4; i++) 2457 if (addr[i] != (input[i] & mask[i])) { 2458 fail = 1; 2459 break; 2460 } 2461 2462 return !fail; 2463 } 2464 2465 /** 2466 * security_node_sid - Obtain the SID for a node (host). 2467 * @domain: communication domain aka address family 2468 * @addrp: address 2469 * @addrlen: address length in bytes 2470 * @out_sid: security identifier 2471 */ 2472 int security_node_sid(struct selinux_state *state, 2473 u16 domain, 2474 void *addrp, 2475 u32 addrlen, 2476 u32 *out_sid) 2477 { 2478 struct policydb *policydb; 2479 struct sidtab *sidtab; 2480 int rc; 2481 struct ocontext *c; 2482 2483 read_lock(&state->ss->policy_rwlock); 2484 2485 policydb = &state->ss->policydb; 2486 sidtab = &state->ss->sidtab; 2487 2488 switch (domain) { 2489 case AF_INET: { 2490 u32 addr; 2491 2492 rc = -EINVAL; 2493 if (addrlen != sizeof(u32)) 2494 goto out; 2495 2496 addr = *((u32 *)addrp); 2497 2498 c = policydb->ocontexts[OCON_NODE]; 2499 while (c) { 2500 if (c->u.node.addr == (addr & c->u.node.mask)) 2501 break; 2502 c = c->next; 2503 } 2504 break; 2505 } 2506 2507 case AF_INET6: 2508 rc = -EINVAL; 2509 if (addrlen != sizeof(u64) * 2) 2510 goto out; 2511 c = policydb->ocontexts[OCON_NODE6]; 2512 while (c) { 2513 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2514 c->u.node6.mask)) 2515 break; 2516 c = c->next; 2517 } 2518 break; 2519 2520 default: 2521 rc = 0; 2522 *out_sid = SECINITSID_NODE; 2523 goto out; 2524 } 2525 2526 if (c) { 2527 if (!c->sid[0]) { 2528 rc = sidtab_context_to_sid(sidtab, 2529 &c->context[0], 2530 &c->sid[0]); 2531 if (rc) 2532 goto out; 2533 } 2534 *out_sid = c->sid[0]; 2535 } else { 2536 *out_sid = SECINITSID_NODE; 2537 } 2538 2539 rc = 0; 2540 out: 2541 read_unlock(&state->ss->policy_rwlock); 2542 return rc; 2543 } 2544 2545 #define SIDS_NEL 25 2546 2547 /** 2548 * security_get_user_sids - Obtain reachable SIDs for a user. 2549 * @fromsid: starting SID 2550 * @username: username 2551 * @sids: array of reachable SIDs for user 2552 * @nel: number of elements in @sids 2553 * 2554 * Generate the set of SIDs for legal security contexts 2555 * for a given user that can be reached by @fromsid. 2556 * Set *@sids to point to a dynamically allocated 2557 * array containing the set of SIDs. Set *@nel to the 2558 * number of elements in the array. 2559 */ 2560 2561 int security_get_user_sids(struct selinux_state *state, 2562 u32 fromsid, 2563 char *username, 2564 u32 **sids, 2565 u32 *nel) 2566 { 2567 struct policydb *policydb; 2568 struct sidtab *sidtab; 2569 struct context *fromcon, usercon; 2570 u32 *mysids = NULL, *mysids2, sid; 2571 u32 mynel = 0, maxnel = SIDS_NEL; 2572 struct user_datum *user; 2573 struct role_datum *role; 2574 struct ebitmap_node *rnode, *tnode; 2575 int rc = 0, i, j; 2576 2577 *sids = NULL; 2578 *nel = 0; 2579 2580 if (!state->initialized) 2581 goto out; 2582 2583 read_lock(&state->ss->policy_rwlock); 2584 2585 policydb = &state->ss->policydb; 2586 sidtab = &state->ss->sidtab; 2587 2588 context_init(&usercon); 2589 2590 rc = -EINVAL; 2591 fromcon = sidtab_search(sidtab, fromsid); 2592 if (!fromcon) 2593 goto out_unlock; 2594 2595 rc = -EINVAL; 2596 user = hashtab_search(policydb->p_users.table, username); 2597 if (!user) 2598 goto out_unlock; 2599 2600 usercon.user = user->value; 2601 2602 rc = -ENOMEM; 2603 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); 2604 if (!mysids) 2605 goto out_unlock; 2606 2607 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2608 role = policydb->role_val_to_struct[i]; 2609 usercon.role = i + 1; 2610 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2611 usercon.type = j + 1; 2612 2613 if (mls_setup_user_range(policydb, fromcon, user, 2614 &usercon)) 2615 continue; 2616 2617 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2618 if (rc) 2619 goto out_unlock; 2620 if (mynel < maxnel) { 2621 mysids[mynel++] = sid; 2622 } else { 2623 rc = -ENOMEM; 2624 maxnel += SIDS_NEL; 2625 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2626 if (!mysids2) 2627 goto out_unlock; 2628 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2629 kfree(mysids); 2630 mysids = mysids2; 2631 mysids[mynel++] = sid; 2632 } 2633 } 2634 } 2635 rc = 0; 2636 out_unlock: 2637 read_unlock(&state->ss->policy_rwlock); 2638 if (rc || !mynel) { 2639 kfree(mysids); 2640 goto out; 2641 } 2642 2643 rc = -ENOMEM; 2644 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2645 if (!mysids2) { 2646 kfree(mysids); 2647 goto out; 2648 } 2649 for (i = 0, j = 0; i < mynel; i++) { 2650 struct av_decision dummy_avd; 2651 rc = avc_has_perm_noaudit(state, 2652 fromsid, mysids[i], 2653 SECCLASS_PROCESS, /* kernel value */ 2654 PROCESS__TRANSITION, AVC_STRICT, 2655 &dummy_avd); 2656 if (!rc) 2657 mysids2[j++] = mysids[i]; 2658 cond_resched(); 2659 } 2660 rc = 0; 2661 kfree(mysids); 2662 *sids = mysids2; 2663 *nel = j; 2664 out: 2665 return rc; 2666 } 2667 2668 /** 2669 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2670 * @fstype: filesystem type 2671 * @path: path from root of mount 2672 * @sclass: file security class 2673 * @sid: SID for path 2674 * 2675 * Obtain a SID to use for a file in a filesystem that 2676 * cannot support xattr or use a fixed labeling behavior like 2677 * transition SIDs or task SIDs. 2678 * 2679 * The caller must acquire the policy_rwlock before calling this function. 2680 */ 2681 static inline int __security_genfs_sid(struct selinux_state *state, 2682 const char *fstype, 2683 char *path, 2684 u16 orig_sclass, 2685 u32 *sid) 2686 { 2687 struct policydb *policydb = &state->ss->policydb; 2688 struct sidtab *sidtab = &state->ss->sidtab; 2689 int len; 2690 u16 sclass; 2691 struct genfs *genfs; 2692 struct ocontext *c; 2693 int rc, cmp = 0; 2694 2695 while (path[0] == '/' && path[1] == '/') 2696 path++; 2697 2698 sclass = unmap_class(&state->ss->map, orig_sclass); 2699 *sid = SECINITSID_UNLABELED; 2700 2701 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2702 cmp = strcmp(fstype, genfs->fstype); 2703 if (cmp <= 0) 2704 break; 2705 } 2706 2707 rc = -ENOENT; 2708 if (!genfs || cmp) 2709 goto out; 2710 2711 for (c = genfs->head; c; c = c->next) { 2712 len = strlen(c->u.name); 2713 if ((!c->v.sclass || sclass == c->v.sclass) && 2714 (strncmp(c->u.name, path, len) == 0)) 2715 break; 2716 } 2717 2718 rc = -ENOENT; 2719 if (!c) 2720 goto out; 2721 2722 if (!c->sid[0]) { 2723 rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]); 2724 if (rc) 2725 goto out; 2726 } 2727 2728 *sid = c->sid[0]; 2729 rc = 0; 2730 out: 2731 return rc; 2732 } 2733 2734 /** 2735 * security_genfs_sid - Obtain a SID for a file in a filesystem 2736 * @fstype: filesystem type 2737 * @path: path from root of mount 2738 * @sclass: file security class 2739 * @sid: SID for path 2740 * 2741 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2742 * it afterward. 2743 */ 2744 int security_genfs_sid(struct selinux_state *state, 2745 const char *fstype, 2746 char *path, 2747 u16 orig_sclass, 2748 u32 *sid) 2749 { 2750 int retval; 2751 2752 read_lock(&state->ss->policy_rwlock); 2753 retval = __security_genfs_sid(state, fstype, path, orig_sclass, sid); 2754 read_unlock(&state->ss->policy_rwlock); 2755 return retval; 2756 } 2757 2758 /** 2759 * security_fs_use - Determine how to handle labeling for a filesystem. 2760 * @sb: superblock in question 2761 */ 2762 int security_fs_use(struct selinux_state *state, struct super_block *sb) 2763 { 2764 struct policydb *policydb; 2765 struct sidtab *sidtab; 2766 int rc = 0; 2767 struct ocontext *c; 2768 struct superblock_security_struct *sbsec = sb->s_security; 2769 const char *fstype = sb->s_type->name; 2770 2771 read_lock(&state->ss->policy_rwlock); 2772 2773 policydb = &state->ss->policydb; 2774 sidtab = &state->ss->sidtab; 2775 2776 c = policydb->ocontexts[OCON_FSUSE]; 2777 while (c) { 2778 if (strcmp(fstype, c->u.name) == 0) 2779 break; 2780 c = c->next; 2781 } 2782 2783 if (c) { 2784 sbsec->behavior = c->v.behavior; 2785 if (!c->sid[0]) { 2786 rc = sidtab_context_to_sid(sidtab, &c->context[0], 2787 &c->sid[0]); 2788 if (rc) 2789 goto out; 2790 } 2791 sbsec->sid = c->sid[0]; 2792 } else { 2793 rc = __security_genfs_sid(state, fstype, "/", SECCLASS_DIR, 2794 &sbsec->sid); 2795 if (rc) { 2796 sbsec->behavior = SECURITY_FS_USE_NONE; 2797 rc = 0; 2798 } else { 2799 sbsec->behavior = SECURITY_FS_USE_GENFS; 2800 } 2801 } 2802 2803 out: 2804 read_unlock(&state->ss->policy_rwlock); 2805 return rc; 2806 } 2807 2808 int security_get_bools(struct selinux_state *state, 2809 int *len, char ***names, int **values) 2810 { 2811 struct policydb *policydb; 2812 int i, rc; 2813 2814 if (!state->initialized) { 2815 *len = 0; 2816 *names = NULL; 2817 *values = NULL; 2818 return 0; 2819 } 2820 2821 read_lock(&state->ss->policy_rwlock); 2822 2823 policydb = &state->ss->policydb; 2824 2825 *names = NULL; 2826 *values = NULL; 2827 2828 rc = 0; 2829 *len = policydb->p_bools.nprim; 2830 if (!*len) 2831 goto out; 2832 2833 rc = -ENOMEM; 2834 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2835 if (!*names) 2836 goto err; 2837 2838 rc = -ENOMEM; 2839 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2840 if (!*values) 2841 goto err; 2842 2843 for (i = 0; i < *len; i++) { 2844 (*values)[i] = policydb->bool_val_to_struct[i]->state; 2845 2846 rc = -ENOMEM; 2847 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 2848 GFP_ATOMIC); 2849 if (!(*names)[i]) 2850 goto err; 2851 } 2852 rc = 0; 2853 out: 2854 read_unlock(&state->ss->policy_rwlock); 2855 return rc; 2856 err: 2857 if (*names) { 2858 for (i = 0; i < *len; i++) 2859 kfree((*names)[i]); 2860 } 2861 kfree(*values); 2862 goto out; 2863 } 2864 2865 2866 int security_set_bools(struct selinux_state *state, int len, int *values) 2867 { 2868 struct policydb *policydb; 2869 int i, rc; 2870 int lenp, seqno = 0; 2871 struct cond_node *cur; 2872 2873 write_lock_irq(&state->ss->policy_rwlock); 2874 2875 policydb = &state->ss->policydb; 2876 2877 rc = -EFAULT; 2878 lenp = policydb->p_bools.nprim; 2879 if (len != lenp) 2880 goto out; 2881 2882 for (i = 0; i < len; i++) { 2883 if (!!values[i] != policydb->bool_val_to_struct[i]->state) { 2884 audit_log(audit_context(), GFP_ATOMIC, 2885 AUDIT_MAC_CONFIG_CHANGE, 2886 "bool=%s val=%d old_val=%d auid=%u ses=%u", 2887 sym_name(policydb, SYM_BOOLS, i), 2888 !!values[i], 2889 policydb->bool_val_to_struct[i]->state, 2890 from_kuid(&init_user_ns, audit_get_loginuid(current)), 2891 audit_get_sessionid(current)); 2892 } 2893 if (values[i]) 2894 policydb->bool_val_to_struct[i]->state = 1; 2895 else 2896 policydb->bool_val_to_struct[i]->state = 0; 2897 } 2898 2899 for (cur = policydb->cond_list; cur; cur = cur->next) { 2900 rc = evaluate_cond_node(policydb, cur); 2901 if (rc) 2902 goto out; 2903 } 2904 2905 seqno = ++state->ss->latest_granting; 2906 rc = 0; 2907 out: 2908 write_unlock_irq(&state->ss->policy_rwlock); 2909 if (!rc) { 2910 avc_ss_reset(state->avc, seqno); 2911 selnl_notify_policyload(seqno); 2912 selinux_status_update_policyload(state, seqno); 2913 selinux_xfrm_notify_policyload(); 2914 } 2915 return rc; 2916 } 2917 2918 int security_get_bool_value(struct selinux_state *state, 2919 int index) 2920 { 2921 struct policydb *policydb; 2922 int rc; 2923 int len; 2924 2925 read_lock(&state->ss->policy_rwlock); 2926 2927 policydb = &state->ss->policydb; 2928 2929 rc = -EFAULT; 2930 len = policydb->p_bools.nprim; 2931 if (index >= len) 2932 goto out; 2933 2934 rc = policydb->bool_val_to_struct[index]->state; 2935 out: 2936 read_unlock(&state->ss->policy_rwlock); 2937 return rc; 2938 } 2939 2940 static int security_preserve_bools(struct selinux_state *state, 2941 struct policydb *policydb) 2942 { 2943 int rc, nbools = 0, *bvalues = NULL, i; 2944 char **bnames = NULL; 2945 struct cond_bool_datum *booldatum; 2946 struct cond_node *cur; 2947 2948 rc = security_get_bools(state, &nbools, &bnames, &bvalues); 2949 if (rc) 2950 goto out; 2951 for (i = 0; i < nbools; i++) { 2952 booldatum = hashtab_search(policydb->p_bools.table, bnames[i]); 2953 if (booldatum) 2954 booldatum->state = bvalues[i]; 2955 } 2956 for (cur = policydb->cond_list; cur; cur = cur->next) { 2957 rc = evaluate_cond_node(policydb, cur); 2958 if (rc) 2959 goto out; 2960 } 2961 2962 out: 2963 if (bnames) { 2964 for (i = 0; i < nbools; i++) 2965 kfree(bnames[i]); 2966 } 2967 kfree(bnames); 2968 kfree(bvalues); 2969 return rc; 2970 } 2971 2972 /* 2973 * security_sid_mls_copy() - computes a new sid based on the given 2974 * sid and the mls portion of mls_sid. 2975 */ 2976 int security_sid_mls_copy(struct selinux_state *state, 2977 u32 sid, u32 mls_sid, u32 *new_sid) 2978 { 2979 struct policydb *policydb = &state->ss->policydb; 2980 struct sidtab *sidtab = &state->ss->sidtab; 2981 struct context *context1; 2982 struct context *context2; 2983 struct context newcon; 2984 char *s; 2985 u32 len; 2986 int rc; 2987 2988 rc = 0; 2989 if (!state->initialized || !policydb->mls_enabled) { 2990 *new_sid = sid; 2991 goto out; 2992 } 2993 2994 context_init(&newcon); 2995 2996 read_lock(&state->ss->policy_rwlock); 2997 2998 rc = -EINVAL; 2999 context1 = sidtab_search(sidtab, sid); 3000 if (!context1) { 3001 pr_err("SELinux: %s: unrecognized SID %d\n", 3002 __func__, sid); 3003 goto out_unlock; 3004 } 3005 3006 rc = -EINVAL; 3007 context2 = sidtab_search(sidtab, mls_sid); 3008 if (!context2) { 3009 pr_err("SELinux: %s: unrecognized SID %d\n", 3010 __func__, mls_sid); 3011 goto out_unlock; 3012 } 3013 3014 newcon.user = context1->user; 3015 newcon.role = context1->role; 3016 newcon.type = context1->type; 3017 rc = mls_context_cpy(&newcon, context2); 3018 if (rc) 3019 goto out_unlock; 3020 3021 /* Check the validity of the new context. */ 3022 if (!policydb_context_isvalid(policydb, &newcon)) { 3023 rc = convert_context_handle_invalid_context(state, &newcon); 3024 if (rc) { 3025 if (!context_struct_to_string(policydb, &newcon, &s, 3026 &len)) { 3027 audit_log(audit_context(), 3028 GFP_ATOMIC, AUDIT_SELINUX_ERR, 3029 "op=security_sid_mls_copy " 3030 "invalid_context=%s", s); 3031 kfree(s); 3032 } 3033 goto out_unlock; 3034 } 3035 } 3036 3037 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3038 out_unlock: 3039 read_unlock(&state->ss->policy_rwlock); 3040 context_destroy(&newcon); 3041 out: 3042 return rc; 3043 } 3044 3045 /** 3046 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3047 * @nlbl_sid: NetLabel SID 3048 * @nlbl_type: NetLabel labeling protocol type 3049 * @xfrm_sid: XFRM SID 3050 * 3051 * Description: 3052 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3053 * resolved into a single SID it is returned via @peer_sid and the function 3054 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3055 * returns a negative value. A table summarizing the behavior is below: 3056 * 3057 * | function return | @sid 3058 * ------------------------------+-----------------+----------------- 3059 * no peer labels | 0 | SECSID_NULL 3060 * single peer label | 0 | <peer_label> 3061 * multiple, consistent labels | 0 | <peer_label> 3062 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3063 * 3064 */ 3065 int security_net_peersid_resolve(struct selinux_state *state, 3066 u32 nlbl_sid, u32 nlbl_type, 3067 u32 xfrm_sid, 3068 u32 *peer_sid) 3069 { 3070 struct policydb *policydb = &state->ss->policydb; 3071 struct sidtab *sidtab = &state->ss->sidtab; 3072 int rc; 3073 struct context *nlbl_ctx; 3074 struct context *xfrm_ctx; 3075 3076 *peer_sid = SECSID_NULL; 3077 3078 /* handle the common (which also happens to be the set of easy) cases 3079 * right away, these two if statements catch everything involving a 3080 * single or absent peer SID/label */ 3081 if (xfrm_sid == SECSID_NULL) { 3082 *peer_sid = nlbl_sid; 3083 return 0; 3084 } 3085 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3086 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3087 * is present */ 3088 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3089 *peer_sid = xfrm_sid; 3090 return 0; 3091 } 3092 3093 /* 3094 * We don't need to check initialized here since the only way both 3095 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3096 * security server was initialized and state->initialized was true. 3097 */ 3098 if (!policydb->mls_enabled) 3099 return 0; 3100 3101 read_lock(&state->ss->policy_rwlock); 3102 3103 rc = -EINVAL; 3104 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3105 if (!nlbl_ctx) { 3106 pr_err("SELinux: %s: unrecognized SID %d\n", 3107 __func__, nlbl_sid); 3108 goto out; 3109 } 3110 rc = -EINVAL; 3111 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3112 if (!xfrm_ctx) { 3113 pr_err("SELinux: %s: unrecognized SID %d\n", 3114 __func__, xfrm_sid); 3115 goto out; 3116 } 3117 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3118 if (rc) 3119 goto out; 3120 3121 /* at present NetLabel SIDs/labels really only carry MLS 3122 * information so if the MLS portion of the NetLabel SID 3123 * matches the MLS portion of the labeled XFRM SID/label 3124 * then pass along the XFRM SID as it is the most 3125 * expressive */ 3126 *peer_sid = xfrm_sid; 3127 out: 3128 read_unlock(&state->ss->policy_rwlock); 3129 return rc; 3130 } 3131 3132 static int get_classes_callback(void *k, void *d, void *args) 3133 { 3134 struct class_datum *datum = d; 3135 char *name = k, **classes = args; 3136 int value = datum->value - 1; 3137 3138 classes[value] = kstrdup(name, GFP_ATOMIC); 3139 if (!classes[value]) 3140 return -ENOMEM; 3141 3142 return 0; 3143 } 3144 3145 int security_get_classes(struct selinux_state *state, 3146 char ***classes, int *nclasses) 3147 { 3148 struct policydb *policydb = &state->ss->policydb; 3149 int rc; 3150 3151 if (!state->initialized) { 3152 *nclasses = 0; 3153 *classes = NULL; 3154 return 0; 3155 } 3156 3157 read_lock(&state->ss->policy_rwlock); 3158 3159 rc = -ENOMEM; 3160 *nclasses = policydb->p_classes.nprim; 3161 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3162 if (!*classes) 3163 goto out; 3164 3165 rc = hashtab_map(policydb->p_classes.table, get_classes_callback, 3166 *classes); 3167 if (rc) { 3168 int i; 3169 for (i = 0; i < *nclasses; i++) 3170 kfree((*classes)[i]); 3171 kfree(*classes); 3172 } 3173 3174 out: 3175 read_unlock(&state->ss->policy_rwlock); 3176 return rc; 3177 } 3178 3179 static int get_permissions_callback(void *k, void *d, void *args) 3180 { 3181 struct perm_datum *datum = d; 3182 char *name = k, **perms = args; 3183 int value = datum->value - 1; 3184 3185 perms[value] = kstrdup(name, GFP_ATOMIC); 3186 if (!perms[value]) 3187 return -ENOMEM; 3188 3189 return 0; 3190 } 3191 3192 int security_get_permissions(struct selinux_state *state, 3193 char *class, char ***perms, int *nperms) 3194 { 3195 struct policydb *policydb = &state->ss->policydb; 3196 int rc, i; 3197 struct class_datum *match; 3198 3199 read_lock(&state->ss->policy_rwlock); 3200 3201 rc = -EINVAL; 3202 match = hashtab_search(policydb->p_classes.table, class); 3203 if (!match) { 3204 pr_err("SELinux: %s: unrecognized class %s\n", 3205 __func__, class); 3206 goto out; 3207 } 3208 3209 rc = -ENOMEM; 3210 *nperms = match->permissions.nprim; 3211 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3212 if (!*perms) 3213 goto out; 3214 3215 if (match->comdatum) { 3216 rc = hashtab_map(match->comdatum->permissions.table, 3217 get_permissions_callback, *perms); 3218 if (rc) 3219 goto err; 3220 } 3221 3222 rc = hashtab_map(match->permissions.table, get_permissions_callback, 3223 *perms); 3224 if (rc) 3225 goto err; 3226 3227 out: 3228 read_unlock(&state->ss->policy_rwlock); 3229 return rc; 3230 3231 err: 3232 read_unlock(&state->ss->policy_rwlock); 3233 for (i = 0; i < *nperms; i++) 3234 kfree((*perms)[i]); 3235 kfree(*perms); 3236 return rc; 3237 } 3238 3239 int security_get_reject_unknown(struct selinux_state *state) 3240 { 3241 return state->ss->policydb.reject_unknown; 3242 } 3243 3244 int security_get_allow_unknown(struct selinux_state *state) 3245 { 3246 return state->ss->policydb.allow_unknown; 3247 } 3248 3249 /** 3250 * security_policycap_supported - Check for a specific policy capability 3251 * @req_cap: capability 3252 * 3253 * Description: 3254 * This function queries the currently loaded policy to see if it supports the 3255 * capability specified by @req_cap. Returns true (1) if the capability is 3256 * supported, false (0) if it isn't supported. 3257 * 3258 */ 3259 int security_policycap_supported(struct selinux_state *state, 3260 unsigned int req_cap) 3261 { 3262 struct policydb *policydb = &state->ss->policydb; 3263 int rc; 3264 3265 read_lock(&state->ss->policy_rwlock); 3266 rc = ebitmap_get_bit(&policydb->policycaps, req_cap); 3267 read_unlock(&state->ss->policy_rwlock); 3268 3269 return rc; 3270 } 3271 3272 struct selinux_audit_rule { 3273 u32 au_seqno; 3274 struct context au_ctxt; 3275 }; 3276 3277 void selinux_audit_rule_free(void *vrule) 3278 { 3279 struct selinux_audit_rule *rule = vrule; 3280 3281 if (rule) { 3282 context_destroy(&rule->au_ctxt); 3283 kfree(rule); 3284 } 3285 } 3286 3287 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3288 { 3289 struct selinux_state *state = &selinux_state; 3290 struct policydb *policydb = &state->ss->policydb; 3291 struct selinux_audit_rule *tmprule; 3292 struct role_datum *roledatum; 3293 struct type_datum *typedatum; 3294 struct user_datum *userdatum; 3295 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3296 int rc = 0; 3297 3298 *rule = NULL; 3299 3300 if (!state->initialized) 3301 return -EOPNOTSUPP; 3302 3303 switch (field) { 3304 case AUDIT_SUBJ_USER: 3305 case AUDIT_SUBJ_ROLE: 3306 case AUDIT_SUBJ_TYPE: 3307 case AUDIT_OBJ_USER: 3308 case AUDIT_OBJ_ROLE: 3309 case AUDIT_OBJ_TYPE: 3310 /* only 'equals' and 'not equals' fit user, role, and type */ 3311 if (op != Audit_equal && op != Audit_not_equal) 3312 return -EINVAL; 3313 break; 3314 case AUDIT_SUBJ_SEN: 3315 case AUDIT_SUBJ_CLR: 3316 case AUDIT_OBJ_LEV_LOW: 3317 case AUDIT_OBJ_LEV_HIGH: 3318 /* we do not allow a range, indicated by the presence of '-' */ 3319 if (strchr(rulestr, '-')) 3320 return -EINVAL; 3321 break; 3322 default: 3323 /* only the above fields are valid */ 3324 return -EINVAL; 3325 } 3326 3327 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3328 if (!tmprule) 3329 return -ENOMEM; 3330 3331 context_init(&tmprule->au_ctxt); 3332 3333 read_lock(&state->ss->policy_rwlock); 3334 3335 tmprule->au_seqno = state->ss->latest_granting; 3336 3337 switch (field) { 3338 case AUDIT_SUBJ_USER: 3339 case AUDIT_OBJ_USER: 3340 rc = -EINVAL; 3341 userdatum = hashtab_search(policydb->p_users.table, rulestr); 3342 if (!userdatum) 3343 goto out; 3344 tmprule->au_ctxt.user = userdatum->value; 3345 break; 3346 case AUDIT_SUBJ_ROLE: 3347 case AUDIT_OBJ_ROLE: 3348 rc = -EINVAL; 3349 roledatum = hashtab_search(policydb->p_roles.table, rulestr); 3350 if (!roledatum) 3351 goto out; 3352 tmprule->au_ctxt.role = roledatum->value; 3353 break; 3354 case AUDIT_SUBJ_TYPE: 3355 case AUDIT_OBJ_TYPE: 3356 rc = -EINVAL; 3357 typedatum = hashtab_search(policydb->p_types.table, rulestr); 3358 if (!typedatum) 3359 goto out; 3360 tmprule->au_ctxt.type = typedatum->value; 3361 break; 3362 case AUDIT_SUBJ_SEN: 3363 case AUDIT_SUBJ_CLR: 3364 case AUDIT_OBJ_LEV_LOW: 3365 case AUDIT_OBJ_LEV_HIGH: 3366 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3367 GFP_ATOMIC); 3368 if (rc) 3369 goto out; 3370 break; 3371 } 3372 rc = 0; 3373 out: 3374 read_unlock(&state->ss->policy_rwlock); 3375 3376 if (rc) { 3377 selinux_audit_rule_free(tmprule); 3378 tmprule = NULL; 3379 } 3380 3381 *rule = tmprule; 3382 3383 return rc; 3384 } 3385 3386 /* Check to see if the rule contains any selinux fields */ 3387 int selinux_audit_rule_known(struct audit_krule *rule) 3388 { 3389 int i; 3390 3391 for (i = 0; i < rule->field_count; i++) { 3392 struct audit_field *f = &rule->fields[i]; 3393 switch (f->type) { 3394 case AUDIT_SUBJ_USER: 3395 case AUDIT_SUBJ_ROLE: 3396 case AUDIT_SUBJ_TYPE: 3397 case AUDIT_SUBJ_SEN: 3398 case AUDIT_SUBJ_CLR: 3399 case AUDIT_OBJ_USER: 3400 case AUDIT_OBJ_ROLE: 3401 case AUDIT_OBJ_TYPE: 3402 case AUDIT_OBJ_LEV_LOW: 3403 case AUDIT_OBJ_LEV_HIGH: 3404 return 1; 3405 } 3406 } 3407 3408 return 0; 3409 } 3410 3411 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, 3412 struct audit_context *actx) 3413 { 3414 struct selinux_state *state = &selinux_state; 3415 struct context *ctxt; 3416 struct mls_level *level; 3417 struct selinux_audit_rule *rule = vrule; 3418 int match = 0; 3419 3420 if (unlikely(!rule)) { 3421 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3422 return -ENOENT; 3423 } 3424 3425 read_lock(&state->ss->policy_rwlock); 3426 3427 if (rule->au_seqno < state->ss->latest_granting) { 3428 match = -ESTALE; 3429 goto out; 3430 } 3431 3432 ctxt = sidtab_search(&state->ss->sidtab, sid); 3433 if (unlikely(!ctxt)) { 3434 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3435 sid); 3436 match = -ENOENT; 3437 goto out; 3438 } 3439 3440 /* a field/op pair that is not caught here will simply fall through 3441 without a match */ 3442 switch (field) { 3443 case AUDIT_SUBJ_USER: 3444 case AUDIT_OBJ_USER: 3445 switch (op) { 3446 case Audit_equal: 3447 match = (ctxt->user == rule->au_ctxt.user); 3448 break; 3449 case Audit_not_equal: 3450 match = (ctxt->user != rule->au_ctxt.user); 3451 break; 3452 } 3453 break; 3454 case AUDIT_SUBJ_ROLE: 3455 case AUDIT_OBJ_ROLE: 3456 switch (op) { 3457 case Audit_equal: 3458 match = (ctxt->role == rule->au_ctxt.role); 3459 break; 3460 case Audit_not_equal: 3461 match = (ctxt->role != rule->au_ctxt.role); 3462 break; 3463 } 3464 break; 3465 case AUDIT_SUBJ_TYPE: 3466 case AUDIT_OBJ_TYPE: 3467 switch (op) { 3468 case Audit_equal: 3469 match = (ctxt->type == rule->au_ctxt.type); 3470 break; 3471 case Audit_not_equal: 3472 match = (ctxt->type != rule->au_ctxt.type); 3473 break; 3474 } 3475 break; 3476 case AUDIT_SUBJ_SEN: 3477 case AUDIT_SUBJ_CLR: 3478 case AUDIT_OBJ_LEV_LOW: 3479 case AUDIT_OBJ_LEV_HIGH: 3480 level = ((field == AUDIT_SUBJ_SEN || 3481 field == AUDIT_OBJ_LEV_LOW) ? 3482 &ctxt->range.level[0] : &ctxt->range.level[1]); 3483 switch (op) { 3484 case Audit_equal: 3485 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3486 level); 3487 break; 3488 case Audit_not_equal: 3489 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3490 level); 3491 break; 3492 case Audit_lt: 3493 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3494 level) && 3495 !mls_level_eq(&rule->au_ctxt.range.level[0], 3496 level)); 3497 break; 3498 case Audit_le: 3499 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3500 level); 3501 break; 3502 case Audit_gt: 3503 match = (mls_level_dom(level, 3504 &rule->au_ctxt.range.level[0]) && 3505 !mls_level_eq(level, 3506 &rule->au_ctxt.range.level[0])); 3507 break; 3508 case Audit_ge: 3509 match = mls_level_dom(level, 3510 &rule->au_ctxt.range.level[0]); 3511 break; 3512 } 3513 } 3514 3515 out: 3516 read_unlock(&state->ss->policy_rwlock); 3517 return match; 3518 } 3519 3520 static int (*aurule_callback)(void) = audit_update_lsm_rules; 3521 3522 static int aurule_avc_callback(u32 event) 3523 { 3524 int err = 0; 3525 3526 if (event == AVC_CALLBACK_RESET && aurule_callback) 3527 err = aurule_callback(); 3528 return err; 3529 } 3530 3531 static int __init aurule_init(void) 3532 { 3533 int err; 3534 3535 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3536 if (err) 3537 panic("avc_add_callback() failed, error %d\n", err); 3538 3539 return err; 3540 } 3541 __initcall(aurule_init); 3542 3543 #ifdef CONFIG_NETLABEL 3544 /** 3545 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3546 * @secattr: the NetLabel packet security attributes 3547 * @sid: the SELinux SID 3548 * 3549 * Description: 3550 * Attempt to cache the context in @ctx, which was derived from the packet in 3551 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3552 * already been initialized. 3553 * 3554 */ 3555 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3556 u32 sid) 3557 { 3558 u32 *sid_cache; 3559 3560 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3561 if (sid_cache == NULL) 3562 return; 3563 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3564 if (secattr->cache == NULL) { 3565 kfree(sid_cache); 3566 return; 3567 } 3568 3569 *sid_cache = sid; 3570 secattr->cache->free = kfree; 3571 secattr->cache->data = sid_cache; 3572 secattr->flags |= NETLBL_SECATTR_CACHE; 3573 } 3574 3575 /** 3576 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3577 * @secattr: the NetLabel packet security attributes 3578 * @sid: the SELinux SID 3579 * 3580 * Description: 3581 * Convert the given NetLabel security attributes in @secattr into a 3582 * SELinux SID. If the @secattr field does not contain a full SELinux 3583 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3584 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3585 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3586 * conversion for future lookups. Returns zero on success, negative values on 3587 * failure. 3588 * 3589 */ 3590 int security_netlbl_secattr_to_sid(struct selinux_state *state, 3591 struct netlbl_lsm_secattr *secattr, 3592 u32 *sid) 3593 { 3594 struct policydb *policydb = &state->ss->policydb; 3595 struct sidtab *sidtab = &state->ss->sidtab; 3596 int rc; 3597 struct context *ctx; 3598 struct context ctx_new; 3599 3600 if (!state->initialized) { 3601 *sid = SECSID_NULL; 3602 return 0; 3603 } 3604 3605 read_lock(&state->ss->policy_rwlock); 3606 3607 if (secattr->flags & NETLBL_SECATTR_CACHE) 3608 *sid = *(u32 *)secattr->cache->data; 3609 else if (secattr->flags & NETLBL_SECATTR_SECID) 3610 *sid = secattr->attr.secid; 3611 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3612 rc = -EIDRM; 3613 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3614 if (ctx == NULL) 3615 goto out; 3616 3617 context_init(&ctx_new); 3618 ctx_new.user = ctx->user; 3619 ctx_new.role = ctx->role; 3620 ctx_new.type = ctx->type; 3621 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3622 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3623 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3624 if (rc) 3625 goto out; 3626 } 3627 rc = -EIDRM; 3628 if (!mls_context_isvalid(policydb, &ctx_new)) 3629 goto out_free; 3630 3631 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3632 if (rc) 3633 goto out_free; 3634 3635 security_netlbl_cache_add(secattr, *sid); 3636 3637 ebitmap_destroy(&ctx_new.range.level[0].cat); 3638 } else 3639 *sid = SECSID_NULL; 3640 3641 read_unlock(&state->ss->policy_rwlock); 3642 return 0; 3643 out_free: 3644 ebitmap_destroy(&ctx_new.range.level[0].cat); 3645 out: 3646 read_unlock(&state->ss->policy_rwlock); 3647 return rc; 3648 } 3649 3650 /** 3651 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3652 * @sid: the SELinux SID 3653 * @secattr: the NetLabel packet security attributes 3654 * 3655 * Description: 3656 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3657 * Returns zero on success, negative values on failure. 3658 * 3659 */ 3660 int security_netlbl_sid_to_secattr(struct selinux_state *state, 3661 u32 sid, struct netlbl_lsm_secattr *secattr) 3662 { 3663 struct policydb *policydb = &state->ss->policydb; 3664 int rc; 3665 struct context *ctx; 3666 3667 if (!state->initialized) 3668 return 0; 3669 3670 read_lock(&state->ss->policy_rwlock); 3671 3672 rc = -ENOENT; 3673 ctx = sidtab_search(&state->ss->sidtab, sid); 3674 if (ctx == NULL) 3675 goto out; 3676 3677 rc = -ENOMEM; 3678 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3679 GFP_ATOMIC); 3680 if (secattr->domain == NULL) 3681 goto out; 3682 3683 secattr->attr.secid = sid; 3684 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3685 mls_export_netlbl_lvl(policydb, ctx, secattr); 3686 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3687 out: 3688 read_unlock(&state->ss->policy_rwlock); 3689 return rc; 3690 } 3691 #endif /* CONFIG_NETLABEL */ 3692 3693 /** 3694 * security_read_policy - read the policy. 3695 * @data: binary policy data 3696 * @len: length of data in bytes 3697 * 3698 */ 3699 int security_read_policy(struct selinux_state *state, 3700 void **data, size_t *len) 3701 { 3702 struct policydb *policydb = &state->ss->policydb; 3703 int rc; 3704 struct policy_file fp; 3705 3706 if (!state->initialized) 3707 return -EINVAL; 3708 3709 *len = security_policydb_len(state); 3710 3711 *data = vmalloc_user(*len); 3712 if (!*data) 3713 return -ENOMEM; 3714 3715 fp.data = *data; 3716 fp.len = *len; 3717 3718 read_lock(&state->ss->policy_rwlock); 3719 rc = policydb_write(policydb, &fp); 3720 read_unlock(&state->ss->policy_rwlock); 3721 3722 if (rc) 3723 return rc; 3724 3725 *len = (unsigned long)fp.data - (unsigned long)*data; 3726 return 0; 3727 3728 } 3729