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 int selinux_policycap_netpeer; 84 int selinux_policycap_openperm; 85 int selinux_policycap_extsockclass; 86 int selinux_policycap_alwaysnetwork; 87 int selinux_policycap_cgroupseclabel; 88 int selinux_policycap_nnp_nosuid_transition; 89 90 static DEFINE_RWLOCK(policy_rwlock); 91 92 static struct sidtab sidtab; 93 struct policydb policydb; 94 int ss_initialized; 95 96 /* 97 * The largest sequence number that has been used when 98 * providing an access decision to the access vector cache. 99 * The sequence number only changes when a policy change 100 * occurs. 101 */ 102 static u32 latest_granting; 103 104 /* Forward declaration. */ 105 static int context_struct_to_string(struct context *context, char **scontext, 106 u32 *scontext_len); 107 108 static void context_struct_compute_av(struct context *scontext, 109 struct context *tcontext, 110 u16 tclass, 111 struct av_decision *avd, 112 struct extended_perms *xperms); 113 114 struct selinux_mapping { 115 u16 value; /* policy value */ 116 unsigned num_perms; 117 u32 perms[sizeof(u32) * 8]; 118 }; 119 120 static struct selinux_mapping *current_mapping; 121 static u16 current_mapping_size; 122 123 static int selinux_set_mapping(struct policydb *pol, 124 struct security_class_mapping *map, 125 struct selinux_mapping **out_map_p, 126 u16 *out_map_size) 127 { 128 struct selinux_mapping *out_map = NULL; 129 size_t size = sizeof(struct selinux_mapping); 130 u16 i, j; 131 unsigned k; 132 bool print_unknown_handle = false; 133 134 /* Find number of classes in the input mapping */ 135 if (!map) 136 return -EINVAL; 137 i = 0; 138 while (map[i].name) 139 i++; 140 141 /* Allocate space for the class records, plus one for class zero */ 142 out_map = kcalloc(++i, size, GFP_ATOMIC); 143 if (!out_map) 144 return -ENOMEM; 145 146 /* Store the raw class and permission values */ 147 j = 0; 148 while (map[j].name) { 149 struct security_class_mapping *p_in = map + (j++); 150 struct selinux_mapping *p_out = out_map + j; 151 152 /* An empty class string skips ahead */ 153 if (!strcmp(p_in->name, "")) { 154 p_out->num_perms = 0; 155 continue; 156 } 157 158 p_out->value = string_to_security_class(pol, p_in->name); 159 if (!p_out->value) { 160 printk(KERN_INFO 161 "SELinux: Class %s not defined in policy.\n", 162 p_in->name); 163 if (pol->reject_unknown) 164 goto err; 165 p_out->num_perms = 0; 166 print_unknown_handle = true; 167 continue; 168 } 169 170 k = 0; 171 while (p_in->perms[k]) { 172 /* An empty permission string skips ahead */ 173 if (!*p_in->perms[k]) { 174 k++; 175 continue; 176 } 177 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 178 p_in->perms[k]); 179 if (!p_out->perms[k]) { 180 printk(KERN_INFO 181 "SELinux: Permission %s in class %s not defined in policy.\n", 182 p_in->perms[k], p_in->name); 183 if (pol->reject_unknown) 184 goto err; 185 print_unknown_handle = true; 186 } 187 188 k++; 189 } 190 p_out->num_perms = k; 191 } 192 193 if (print_unknown_handle) 194 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n", 195 pol->allow_unknown ? "allowed" : "denied"); 196 197 *out_map_p = out_map; 198 *out_map_size = i; 199 return 0; 200 err: 201 kfree(out_map); 202 return -EINVAL; 203 } 204 205 /* 206 * Get real, policy values from mapped values 207 */ 208 209 static u16 unmap_class(u16 tclass) 210 { 211 if (tclass < current_mapping_size) 212 return current_mapping[tclass].value; 213 214 return tclass; 215 } 216 217 /* 218 * Get kernel value for class from its policy value 219 */ 220 static u16 map_class(u16 pol_value) 221 { 222 u16 i; 223 224 for (i = 1; i < current_mapping_size; i++) { 225 if (current_mapping[i].value == pol_value) 226 return i; 227 } 228 229 return SECCLASS_NULL; 230 } 231 232 static void map_decision(u16 tclass, struct av_decision *avd, 233 int allow_unknown) 234 { 235 if (tclass < current_mapping_size) { 236 unsigned i, n = current_mapping[tclass].num_perms; 237 u32 result; 238 239 for (i = 0, result = 0; i < n; i++) { 240 if (avd->allowed & current_mapping[tclass].perms[i]) 241 result |= 1<<i; 242 if (allow_unknown && !current_mapping[tclass].perms[i]) 243 result |= 1<<i; 244 } 245 avd->allowed = result; 246 247 for (i = 0, result = 0; i < n; i++) 248 if (avd->auditallow & current_mapping[tclass].perms[i]) 249 result |= 1<<i; 250 avd->auditallow = result; 251 252 for (i = 0, result = 0; i < n; i++) { 253 if (avd->auditdeny & current_mapping[tclass].perms[i]) 254 result |= 1<<i; 255 if (!allow_unknown && !current_mapping[tclass].perms[i]) 256 result |= 1<<i; 257 } 258 /* 259 * In case the kernel has a bug and requests a permission 260 * between num_perms and the maximum permission number, we 261 * should audit that denial 262 */ 263 for (; i < (sizeof(u32)*8); i++) 264 result |= 1<<i; 265 avd->auditdeny = result; 266 } 267 } 268 269 int security_mls_enabled(void) 270 { 271 return policydb.mls_enabled; 272 } 273 274 /* 275 * Return the boolean value of a constraint expression 276 * when it is applied to the specified source and target 277 * security contexts. 278 * 279 * xcontext is a special beast... It is used by the validatetrans rules 280 * only. For these rules, scontext is the context before the transition, 281 * tcontext is the context after the transition, and xcontext is the context 282 * of the process performing the transition. All other callers of 283 * constraint_expr_eval should pass in NULL for xcontext. 284 */ 285 static int constraint_expr_eval(struct context *scontext, 286 struct context *tcontext, 287 struct context *xcontext, 288 struct constraint_expr *cexpr) 289 { 290 u32 val1, val2; 291 struct context *c; 292 struct role_datum *r1, *r2; 293 struct mls_level *l1, *l2; 294 struct constraint_expr *e; 295 int s[CEXPR_MAXDEPTH]; 296 int sp = -1; 297 298 for (e = cexpr; e; e = e->next) { 299 switch (e->expr_type) { 300 case CEXPR_NOT: 301 BUG_ON(sp < 0); 302 s[sp] = !s[sp]; 303 break; 304 case CEXPR_AND: 305 BUG_ON(sp < 1); 306 sp--; 307 s[sp] &= s[sp + 1]; 308 break; 309 case CEXPR_OR: 310 BUG_ON(sp < 1); 311 sp--; 312 s[sp] |= s[sp + 1]; 313 break; 314 case CEXPR_ATTR: 315 if (sp == (CEXPR_MAXDEPTH - 1)) 316 return 0; 317 switch (e->attr) { 318 case CEXPR_USER: 319 val1 = scontext->user; 320 val2 = tcontext->user; 321 break; 322 case CEXPR_TYPE: 323 val1 = scontext->type; 324 val2 = tcontext->type; 325 break; 326 case CEXPR_ROLE: 327 val1 = scontext->role; 328 val2 = tcontext->role; 329 r1 = policydb.role_val_to_struct[val1 - 1]; 330 r2 = policydb.role_val_to_struct[val2 - 1]; 331 switch (e->op) { 332 case CEXPR_DOM: 333 s[++sp] = ebitmap_get_bit(&r1->dominates, 334 val2 - 1); 335 continue; 336 case CEXPR_DOMBY: 337 s[++sp] = ebitmap_get_bit(&r2->dominates, 338 val1 - 1); 339 continue; 340 case CEXPR_INCOMP: 341 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 342 val2 - 1) && 343 !ebitmap_get_bit(&r2->dominates, 344 val1 - 1)); 345 continue; 346 default: 347 break; 348 } 349 break; 350 case CEXPR_L1L2: 351 l1 = &(scontext->range.level[0]); 352 l2 = &(tcontext->range.level[0]); 353 goto mls_ops; 354 case CEXPR_L1H2: 355 l1 = &(scontext->range.level[0]); 356 l2 = &(tcontext->range.level[1]); 357 goto mls_ops; 358 case CEXPR_H1L2: 359 l1 = &(scontext->range.level[1]); 360 l2 = &(tcontext->range.level[0]); 361 goto mls_ops; 362 case CEXPR_H1H2: 363 l1 = &(scontext->range.level[1]); 364 l2 = &(tcontext->range.level[1]); 365 goto mls_ops; 366 case CEXPR_L1H1: 367 l1 = &(scontext->range.level[0]); 368 l2 = &(scontext->range.level[1]); 369 goto mls_ops; 370 case CEXPR_L2H2: 371 l1 = &(tcontext->range.level[0]); 372 l2 = &(tcontext->range.level[1]); 373 goto mls_ops; 374 mls_ops: 375 switch (e->op) { 376 case CEXPR_EQ: 377 s[++sp] = mls_level_eq(l1, l2); 378 continue; 379 case CEXPR_NEQ: 380 s[++sp] = !mls_level_eq(l1, l2); 381 continue; 382 case CEXPR_DOM: 383 s[++sp] = mls_level_dom(l1, l2); 384 continue; 385 case CEXPR_DOMBY: 386 s[++sp] = mls_level_dom(l2, l1); 387 continue; 388 case CEXPR_INCOMP: 389 s[++sp] = mls_level_incomp(l2, l1); 390 continue; 391 default: 392 BUG(); 393 return 0; 394 } 395 break; 396 default: 397 BUG(); 398 return 0; 399 } 400 401 switch (e->op) { 402 case CEXPR_EQ: 403 s[++sp] = (val1 == val2); 404 break; 405 case CEXPR_NEQ: 406 s[++sp] = (val1 != val2); 407 break; 408 default: 409 BUG(); 410 return 0; 411 } 412 break; 413 case CEXPR_NAMES: 414 if (sp == (CEXPR_MAXDEPTH-1)) 415 return 0; 416 c = scontext; 417 if (e->attr & CEXPR_TARGET) 418 c = tcontext; 419 else if (e->attr & CEXPR_XTARGET) { 420 c = xcontext; 421 if (!c) { 422 BUG(); 423 return 0; 424 } 425 } 426 if (e->attr & CEXPR_USER) 427 val1 = c->user; 428 else if (e->attr & CEXPR_ROLE) 429 val1 = c->role; 430 else if (e->attr & CEXPR_TYPE) 431 val1 = c->type; 432 else { 433 BUG(); 434 return 0; 435 } 436 437 switch (e->op) { 438 case CEXPR_EQ: 439 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 440 break; 441 case CEXPR_NEQ: 442 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 443 break; 444 default: 445 BUG(); 446 return 0; 447 } 448 break; 449 default: 450 BUG(); 451 return 0; 452 } 453 } 454 455 BUG_ON(sp != 0); 456 return s[0]; 457 } 458 459 /* 460 * security_dump_masked_av - dumps masked permissions during 461 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 462 */ 463 static int dump_masked_av_helper(void *k, void *d, void *args) 464 { 465 struct perm_datum *pdatum = d; 466 char **permission_names = args; 467 468 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 469 470 permission_names[pdatum->value - 1] = (char *)k; 471 472 return 0; 473 } 474 475 static void security_dump_masked_av(struct context *scontext, 476 struct context *tcontext, 477 u16 tclass, 478 u32 permissions, 479 const char *reason) 480 { 481 struct common_datum *common_dat; 482 struct class_datum *tclass_dat; 483 struct audit_buffer *ab; 484 char *tclass_name; 485 char *scontext_name = NULL; 486 char *tcontext_name = NULL; 487 char *permission_names[32]; 488 int index; 489 u32 length; 490 bool need_comma = false; 491 492 if (!permissions) 493 return; 494 495 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1); 496 tclass_dat = policydb.class_val_to_struct[tclass - 1]; 497 common_dat = tclass_dat->comdatum; 498 499 /* init permission_names */ 500 if (common_dat && 501 hashtab_map(common_dat->permissions.table, 502 dump_masked_av_helper, permission_names) < 0) 503 goto out; 504 505 if (hashtab_map(tclass_dat->permissions.table, 506 dump_masked_av_helper, permission_names) < 0) 507 goto out; 508 509 /* get scontext/tcontext in text form */ 510 if (context_struct_to_string(scontext, 511 &scontext_name, &length) < 0) 512 goto out; 513 514 if (context_struct_to_string(tcontext, 515 &tcontext_name, &length) < 0) 516 goto out; 517 518 /* audit a message */ 519 ab = audit_log_start(current->audit_context, 520 GFP_ATOMIC, AUDIT_SELINUX_ERR); 521 if (!ab) 522 goto out; 523 524 audit_log_format(ab, "op=security_compute_av reason=%s " 525 "scontext=%s tcontext=%s tclass=%s perms=", 526 reason, scontext_name, tcontext_name, tclass_name); 527 528 for (index = 0; index < 32; index++) { 529 u32 mask = (1 << index); 530 531 if ((mask & permissions) == 0) 532 continue; 533 534 audit_log_format(ab, "%s%s", 535 need_comma ? "," : "", 536 permission_names[index] 537 ? permission_names[index] : "????"); 538 need_comma = true; 539 } 540 audit_log_end(ab); 541 out: 542 /* release scontext/tcontext */ 543 kfree(tcontext_name); 544 kfree(scontext_name); 545 546 return; 547 } 548 549 /* 550 * security_boundary_permission - drops violated permissions 551 * on boundary constraint. 552 */ 553 static void type_attribute_bounds_av(struct context *scontext, 554 struct context *tcontext, 555 u16 tclass, 556 struct av_decision *avd) 557 { 558 struct context lo_scontext; 559 struct context lo_tcontext, *tcontextp = tcontext; 560 struct av_decision lo_avd; 561 struct type_datum *source; 562 struct type_datum *target; 563 u32 masked = 0; 564 565 source = flex_array_get_ptr(policydb.type_val_to_struct_array, 566 scontext->type - 1); 567 BUG_ON(!source); 568 569 if (!source->bounds) 570 return; 571 572 target = flex_array_get_ptr(policydb.type_val_to_struct_array, 573 tcontext->type - 1); 574 BUG_ON(!target); 575 576 memset(&lo_avd, 0, sizeof(lo_avd)); 577 578 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 579 lo_scontext.type = source->bounds; 580 581 if (target->bounds) { 582 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 583 lo_tcontext.type = target->bounds; 584 tcontextp = &lo_tcontext; 585 } 586 587 context_struct_compute_av(&lo_scontext, 588 tcontextp, 589 tclass, 590 &lo_avd, 591 NULL); 592 593 masked = ~lo_avd.allowed & avd->allowed; 594 595 if (likely(!masked)) 596 return; /* no masked permission */ 597 598 /* mask violated permissions */ 599 avd->allowed &= ~masked; 600 601 /* audit masked permissions */ 602 security_dump_masked_av(scontext, tcontext, 603 tclass, masked, "bounds"); 604 } 605 606 /* 607 * flag which drivers have permissions 608 * only looking for ioctl based extended permssions 609 */ 610 void services_compute_xperms_drivers( 611 struct extended_perms *xperms, 612 struct avtab_node *node) 613 { 614 unsigned int i; 615 616 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 617 /* if one or more driver has all permissions allowed */ 618 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 619 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 620 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 621 /* if allowing permissions within a driver */ 622 security_xperm_set(xperms->drivers.p, 623 node->datum.u.xperms->driver); 624 } 625 626 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */ 627 if (node->key.specified & AVTAB_XPERMS_ALLOWED) 628 xperms->len = 1; 629 } 630 631 /* 632 * Compute access vectors and extended permissions based on a context 633 * structure pair for the permissions in a particular class. 634 */ 635 static void context_struct_compute_av(struct context *scontext, 636 struct context *tcontext, 637 u16 tclass, 638 struct av_decision *avd, 639 struct extended_perms *xperms) 640 { 641 struct constraint_node *constraint; 642 struct role_allow *ra; 643 struct avtab_key avkey; 644 struct avtab_node *node; 645 struct class_datum *tclass_datum; 646 struct ebitmap *sattr, *tattr; 647 struct ebitmap_node *snode, *tnode; 648 unsigned int i, j; 649 650 avd->allowed = 0; 651 avd->auditallow = 0; 652 avd->auditdeny = 0xffffffff; 653 if (xperms) { 654 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 655 xperms->len = 0; 656 } 657 658 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 659 if (printk_ratelimit()) 660 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass); 661 return; 662 } 663 664 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 665 666 /* 667 * If a specific type enforcement rule was defined for 668 * this permission check, then use it. 669 */ 670 avkey.target_class = tclass; 671 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 672 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1); 673 BUG_ON(!sattr); 674 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1); 675 BUG_ON(!tattr); 676 ebitmap_for_each_positive_bit(sattr, snode, i) { 677 ebitmap_for_each_positive_bit(tattr, tnode, j) { 678 avkey.source_type = i + 1; 679 avkey.target_type = j + 1; 680 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 681 node; 682 node = avtab_search_node_next(node, avkey.specified)) { 683 if (node->key.specified == AVTAB_ALLOWED) 684 avd->allowed |= node->datum.u.data; 685 else if (node->key.specified == AVTAB_AUDITALLOW) 686 avd->auditallow |= node->datum.u.data; 687 else if (node->key.specified == AVTAB_AUDITDENY) 688 avd->auditdeny &= node->datum.u.data; 689 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 690 services_compute_xperms_drivers(xperms, node); 691 } 692 693 /* Check conditional av table for additional permissions */ 694 cond_compute_av(&policydb.te_cond_avtab, &avkey, 695 avd, xperms); 696 697 } 698 } 699 700 /* 701 * Remove any permissions prohibited by a constraint (this includes 702 * the MLS policy). 703 */ 704 constraint = tclass_datum->constraints; 705 while (constraint) { 706 if ((constraint->permissions & (avd->allowed)) && 707 !constraint_expr_eval(scontext, tcontext, NULL, 708 constraint->expr)) { 709 avd->allowed &= ~(constraint->permissions); 710 } 711 constraint = constraint->next; 712 } 713 714 /* 715 * If checking process transition permission and the 716 * role is changing, then check the (current_role, new_role) 717 * pair. 718 */ 719 if (tclass == policydb.process_class && 720 (avd->allowed & policydb.process_trans_perms) && 721 scontext->role != tcontext->role) { 722 for (ra = policydb.role_allow; ra; ra = ra->next) { 723 if (scontext->role == ra->role && 724 tcontext->role == ra->new_role) 725 break; 726 } 727 if (!ra) 728 avd->allowed &= ~policydb.process_trans_perms; 729 } 730 731 /* 732 * If the given source and target types have boundary 733 * constraint, lazy checks have to mask any violated 734 * permission and notice it to userspace via audit. 735 */ 736 type_attribute_bounds_av(scontext, tcontext, 737 tclass, avd); 738 } 739 740 static int security_validtrans_handle_fail(struct context *ocontext, 741 struct context *ncontext, 742 struct context *tcontext, 743 u16 tclass) 744 { 745 char *o = NULL, *n = NULL, *t = NULL; 746 u32 olen, nlen, tlen; 747 748 if (context_struct_to_string(ocontext, &o, &olen)) 749 goto out; 750 if (context_struct_to_string(ncontext, &n, &nlen)) 751 goto out; 752 if (context_struct_to_string(tcontext, &t, &tlen)) 753 goto out; 754 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 755 "op=security_validate_transition seresult=denied" 756 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 757 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 758 out: 759 kfree(o); 760 kfree(n); 761 kfree(t); 762 763 if (!selinux_enforcing) 764 return 0; 765 return -EPERM; 766 } 767 768 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid, 769 u16 orig_tclass, bool user) 770 { 771 struct context *ocontext; 772 struct context *ncontext; 773 struct context *tcontext; 774 struct class_datum *tclass_datum; 775 struct constraint_node *constraint; 776 u16 tclass; 777 int rc = 0; 778 779 if (!ss_initialized) 780 return 0; 781 782 read_lock(&policy_rwlock); 783 784 if (!user) 785 tclass = unmap_class(orig_tclass); 786 else 787 tclass = orig_tclass; 788 789 if (!tclass || tclass > policydb.p_classes.nprim) { 790 rc = -EINVAL; 791 goto out; 792 } 793 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 794 795 ocontext = sidtab_search(&sidtab, oldsid); 796 if (!ocontext) { 797 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 798 __func__, oldsid); 799 rc = -EINVAL; 800 goto out; 801 } 802 803 ncontext = sidtab_search(&sidtab, newsid); 804 if (!ncontext) { 805 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 806 __func__, newsid); 807 rc = -EINVAL; 808 goto out; 809 } 810 811 tcontext = sidtab_search(&sidtab, tasksid); 812 if (!tcontext) { 813 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 814 __func__, tasksid); 815 rc = -EINVAL; 816 goto out; 817 } 818 819 constraint = tclass_datum->validatetrans; 820 while (constraint) { 821 if (!constraint_expr_eval(ocontext, ncontext, tcontext, 822 constraint->expr)) { 823 if (user) 824 rc = -EPERM; 825 else 826 rc = security_validtrans_handle_fail(ocontext, 827 ncontext, 828 tcontext, 829 tclass); 830 goto out; 831 } 832 constraint = constraint->next; 833 } 834 835 out: 836 read_unlock(&policy_rwlock); 837 return rc; 838 } 839 840 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, 841 u16 tclass) 842 { 843 return security_compute_validatetrans(oldsid, newsid, tasksid, 844 tclass, true); 845 } 846 847 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 848 u16 orig_tclass) 849 { 850 return security_compute_validatetrans(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(u32 old_sid, u32 new_sid) 864 { 865 struct context *old_context, *new_context; 866 struct type_datum *type; 867 int index; 868 int rc; 869 870 read_lock(&policy_rwlock); 871 872 rc = -EINVAL; 873 old_context = sidtab_search(&sidtab, old_sid); 874 if (!old_context) { 875 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 876 __func__, old_sid); 877 goto out; 878 } 879 880 rc = -EINVAL; 881 new_context = sidtab_search(&sidtab, new_sid); 882 if (!new_context) { 883 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 884 __func__, new_sid); 885 goto out; 886 } 887 888 rc = 0; 889 /* type/domain unchanged */ 890 if (old_context->type == new_context->type) 891 goto out; 892 893 index = new_context->type; 894 while (true) { 895 type = flex_array_get_ptr(policydb.type_val_to_struct_array, 896 index - 1); 897 BUG_ON(!type); 898 899 /* not bounded anymore */ 900 rc = -EPERM; 901 if (!type->bounds) 902 break; 903 904 /* @newsid is bounded by @oldsid */ 905 rc = 0; 906 if (type->bounds == old_context->type) 907 break; 908 909 index = type->bounds; 910 } 911 912 if (rc) { 913 char *old_name = NULL; 914 char *new_name = NULL; 915 u32 length; 916 917 if (!context_struct_to_string(old_context, 918 &old_name, &length) && 919 !context_struct_to_string(new_context, 920 &new_name, &length)) { 921 audit_log(current->audit_context, 922 GFP_ATOMIC, AUDIT_SELINUX_ERR, 923 "op=security_bounded_transition " 924 "seresult=denied " 925 "oldcontext=%s newcontext=%s", 926 old_name, new_name); 927 } 928 kfree(new_name); 929 kfree(old_name); 930 } 931 out: 932 read_unlock(&policy_rwlock); 933 934 return rc; 935 } 936 937 static void avd_init(struct av_decision *avd) 938 { 939 avd->allowed = 0; 940 avd->auditallow = 0; 941 avd->auditdeny = 0xffffffff; 942 avd->seqno = latest_granting; 943 avd->flags = 0; 944 } 945 946 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 947 struct avtab_node *node) 948 { 949 unsigned int i; 950 951 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 952 if (xpermd->driver != node->datum.u.xperms->driver) 953 return; 954 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 955 if (!security_xperm_test(node->datum.u.xperms->perms.p, 956 xpermd->driver)) 957 return; 958 } else { 959 BUG(); 960 } 961 962 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 963 xpermd->used |= XPERMS_ALLOWED; 964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 965 memset(xpermd->allowed->p, 0xff, 966 sizeof(xpermd->allowed->p)); 967 } 968 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 969 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 970 xpermd->allowed->p[i] |= 971 node->datum.u.xperms->perms.p[i]; 972 } 973 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 974 xpermd->used |= XPERMS_AUDITALLOW; 975 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 976 memset(xpermd->auditallow->p, 0xff, 977 sizeof(xpermd->auditallow->p)); 978 } 979 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 980 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 981 xpermd->auditallow->p[i] |= 982 node->datum.u.xperms->perms.p[i]; 983 } 984 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 985 xpermd->used |= XPERMS_DONTAUDIT; 986 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 987 memset(xpermd->dontaudit->p, 0xff, 988 sizeof(xpermd->dontaudit->p)); 989 } 990 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 991 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 992 xpermd->dontaudit->p[i] |= 993 node->datum.u.xperms->perms.p[i]; 994 } 995 } else { 996 BUG(); 997 } 998 } 999 1000 void security_compute_xperms_decision(u32 ssid, 1001 u32 tsid, 1002 u16 orig_tclass, 1003 u8 driver, 1004 struct extended_perms_decision *xpermd) 1005 { 1006 u16 tclass; 1007 struct context *scontext, *tcontext; 1008 struct avtab_key avkey; 1009 struct avtab_node *node; 1010 struct ebitmap *sattr, *tattr; 1011 struct ebitmap_node *snode, *tnode; 1012 unsigned int i, j; 1013 1014 xpermd->driver = driver; 1015 xpermd->used = 0; 1016 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1017 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1018 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1019 1020 read_lock(&policy_rwlock); 1021 if (!ss_initialized) 1022 goto allow; 1023 1024 scontext = sidtab_search(&sidtab, ssid); 1025 if (!scontext) { 1026 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1027 __func__, ssid); 1028 goto out; 1029 } 1030 1031 tcontext = sidtab_search(&sidtab, tsid); 1032 if (!tcontext) { 1033 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1034 __func__, tsid); 1035 goto out; 1036 } 1037 1038 tclass = unmap_class(orig_tclass); 1039 if (unlikely(orig_tclass && !tclass)) { 1040 if (policydb.allow_unknown) 1041 goto allow; 1042 goto out; 1043 } 1044 1045 1046 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 1047 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1048 goto out; 1049 } 1050 1051 avkey.target_class = tclass; 1052 avkey.specified = AVTAB_XPERMS; 1053 sattr = flex_array_get(policydb.type_attr_map_array, 1054 scontext->type - 1); 1055 BUG_ON(!sattr); 1056 tattr = flex_array_get(policydb.type_attr_map_array, 1057 tcontext->type - 1); 1058 BUG_ON(!tattr); 1059 ebitmap_for_each_positive_bit(sattr, snode, i) { 1060 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1061 avkey.source_type = i + 1; 1062 avkey.target_type = j + 1; 1063 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 1064 node; 1065 node = avtab_search_node_next(node, avkey.specified)) 1066 services_compute_xperms_decision(xpermd, node); 1067 1068 cond_compute_xperms(&policydb.te_cond_avtab, 1069 &avkey, xpermd); 1070 } 1071 } 1072 out: 1073 read_unlock(&policy_rwlock); 1074 return; 1075 allow: 1076 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1077 goto out; 1078 } 1079 1080 /** 1081 * security_compute_av - Compute access vector decisions. 1082 * @ssid: source security identifier 1083 * @tsid: target security identifier 1084 * @tclass: target security class 1085 * @avd: access vector decisions 1086 * @xperms: extended permissions 1087 * 1088 * Compute a set of access vector decisions based on the 1089 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1090 */ 1091 void security_compute_av(u32 ssid, 1092 u32 tsid, 1093 u16 orig_tclass, 1094 struct av_decision *avd, 1095 struct extended_perms *xperms) 1096 { 1097 u16 tclass; 1098 struct context *scontext = NULL, *tcontext = NULL; 1099 1100 read_lock(&policy_rwlock); 1101 avd_init(avd); 1102 xperms->len = 0; 1103 if (!ss_initialized) 1104 goto allow; 1105 1106 scontext = sidtab_search(&sidtab, ssid); 1107 if (!scontext) { 1108 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1109 __func__, ssid); 1110 goto out; 1111 } 1112 1113 /* permissive domain? */ 1114 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1115 avd->flags |= AVD_FLAGS_PERMISSIVE; 1116 1117 tcontext = sidtab_search(&sidtab, tsid); 1118 if (!tcontext) { 1119 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1120 __func__, tsid); 1121 goto out; 1122 } 1123 1124 tclass = unmap_class(orig_tclass); 1125 if (unlikely(orig_tclass && !tclass)) { 1126 if (policydb.allow_unknown) 1127 goto allow; 1128 goto out; 1129 } 1130 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms); 1131 map_decision(orig_tclass, avd, policydb.allow_unknown); 1132 out: 1133 read_unlock(&policy_rwlock); 1134 return; 1135 allow: 1136 avd->allowed = 0xffffffff; 1137 goto out; 1138 } 1139 1140 void security_compute_av_user(u32 ssid, 1141 u32 tsid, 1142 u16 tclass, 1143 struct av_decision *avd) 1144 { 1145 struct context *scontext = NULL, *tcontext = NULL; 1146 1147 read_lock(&policy_rwlock); 1148 avd_init(avd); 1149 if (!ss_initialized) 1150 goto allow; 1151 1152 scontext = sidtab_search(&sidtab, ssid); 1153 if (!scontext) { 1154 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1155 __func__, ssid); 1156 goto out; 1157 } 1158 1159 /* permissive domain? */ 1160 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1161 avd->flags |= AVD_FLAGS_PERMISSIVE; 1162 1163 tcontext = sidtab_search(&sidtab, tsid); 1164 if (!tcontext) { 1165 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1166 __func__, tsid); 1167 goto out; 1168 } 1169 1170 if (unlikely(!tclass)) { 1171 if (policydb.allow_unknown) 1172 goto allow; 1173 goto out; 1174 } 1175 1176 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL); 1177 out: 1178 read_unlock(&policy_rwlock); 1179 return; 1180 allow: 1181 avd->allowed = 0xffffffff; 1182 goto out; 1183 } 1184 1185 /* 1186 * Write the security context string representation of 1187 * the context structure `context' into a dynamically 1188 * allocated string of the correct size. Set `*scontext' 1189 * to point to this string and set `*scontext_len' to 1190 * the length of the string. 1191 */ 1192 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) 1193 { 1194 char *scontextp; 1195 1196 if (scontext) 1197 *scontext = NULL; 1198 *scontext_len = 0; 1199 1200 if (context->len) { 1201 *scontext_len = context->len; 1202 if (scontext) { 1203 *scontext = kstrdup(context->str, GFP_ATOMIC); 1204 if (!(*scontext)) 1205 return -ENOMEM; 1206 } 1207 return 0; 1208 } 1209 1210 /* Compute the size of the context. */ 1211 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1; 1212 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1; 1213 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1; 1214 *scontext_len += mls_compute_context_len(context); 1215 1216 if (!scontext) 1217 return 0; 1218 1219 /* Allocate space for the context; caller must free this space. */ 1220 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1221 if (!scontextp) 1222 return -ENOMEM; 1223 *scontext = scontextp; 1224 1225 /* 1226 * Copy the user name, role name and type name into the context. 1227 */ 1228 scontextp += sprintf(scontextp, "%s:%s:%s", 1229 sym_name(&policydb, SYM_USERS, context->user - 1), 1230 sym_name(&policydb, SYM_ROLES, context->role - 1), 1231 sym_name(&policydb, SYM_TYPES, context->type - 1)); 1232 1233 mls_sid_to_context(context, &scontextp); 1234 1235 *scontextp = 0; 1236 1237 return 0; 1238 } 1239 1240 #include "initial_sid_to_string.h" 1241 1242 const char *security_get_initial_sid_context(u32 sid) 1243 { 1244 if (unlikely(sid > SECINITSID_NUM)) 1245 return NULL; 1246 return initial_sid_to_string[sid]; 1247 } 1248 1249 static int security_sid_to_context_core(u32 sid, char **scontext, 1250 u32 *scontext_len, int force) 1251 { 1252 struct context *context; 1253 int rc = 0; 1254 1255 if (scontext) 1256 *scontext = NULL; 1257 *scontext_len = 0; 1258 1259 if (!ss_initialized) { 1260 if (sid <= SECINITSID_NUM) { 1261 char *scontextp; 1262 1263 *scontext_len = strlen(initial_sid_to_string[sid]) + 1; 1264 if (!scontext) 1265 goto out; 1266 scontextp = kmemdup(initial_sid_to_string[sid], 1267 *scontext_len, GFP_ATOMIC); 1268 if (!scontextp) { 1269 rc = -ENOMEM; 1270 goto out; 1271 } 1272 *scontext = scontextp; 1273 goto out; 1274 } 1275 printk(KERN_ERR "SELinux: %s: called before initial " 1276 "load_policy on unknown SID %d\n", __func__, sid); 1277 rc = -EINVAL; 1278 goto out; 1279 } 1280 read_lock(&policy_rwlock); 1281 if (force) 1282 context = sidtab_search_force(&sidtab, sid); 1283 else 1284 context = sidtab_search(&sidtab, sid); 1285 if (!context) { 1286 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1287 __func__, sid); 1288 rc = -EINVAL; 1289 goto out_unlock; 1290 } 1291 rc = context_struct_to_string(context, scontext, scontext_len); 1292 out_unlock: 1293 read_unlock(&policy_rwlock); 1294 out: 1295 return rc; 1296 1297 } 1298 1299 /** 1300 * security_sid_to_context - Obtain a context for a given SID. 1301 * @sid: security identifier, SID 1302 * @scontext: security context 1303 * @scontext_len: length in bytes 1304 * 1305 * Write the string representation of the context associated with @sid 1306 * into a dynamically allocated string of the correct size. Set @scontext 1307 * to point to this string and set @scontext_len to the length of the string. 1308 */ 1309 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1310 { 1311 return security_sid_to_context_core(sid, scontext, scontext_len, 0); 1312 } 1313 1314 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len) 1315 { 1316 return security_sid_to_context_core(sid, scontext, scontext_len, 1); 1317 } 1318 1319 /* 1320 * Caveat: Mutates scontext. 1321 */ 1322 static int string_to_context_struct(struct policydb *pol, 1323 struct sidtab *sidtabp, 1324 char *scontext, 1325 u32 scontext_len, 1326 struct context *ctx, 1327 u32 def_sid) 1328 { 1329 struct role_datum *role; 1330 struct type_datum *typdatum; 1331 struct user_datum *usrdatum; 1332 char *scontextp, *p, oldc; 1333 int rc = 0; 1334 1335 context_init(ctx); 1336 1337 /* Parse the security context. */ 1338 1339 rc = -EINVAL; 1340 scontextp = (char *) scontext; 1341 1342 /* Extract the user. */ 1343 p = scontextp; 1344 while (*p && *p != ':') 1345 p++; 1346 1347 if (*p == 0) 1348 goto out; 1349 1350 *p++ = 0; 1351 1352 usrdatum = hashtab_search(pol->p_users.table, scontextp); 1353 if (!usrdatum) 1354 goto out; 1355 1356 ctx->user = usrdatum->value; 1357 1358 /* Extract role. */ 1359 scontextp = p; 1360 while (*p && *p != ':') 1361 p++; 1362 1363 if (*p == 0) 1364 goto out; 1365 1366 *p++ = 0; 1367 1368 role = hashtab_search(pol->p_roles.table, scontextp); 1369 if (!role) 1370 goto out; 1371 ctx->role = role->value; 1372 1373 /* Extract type. */ 1374 scontextp = p; 1375 while (*p && *p != ':') 1376 p++; 1377 oldc = *p; 1378 *p++ = 0; 1379 1380 typdatum = hashtab_search(pol->p_types.table, scontextp); 1381 if (!typdatum || typdatum->attribute) 1382 goto out; 1383 1384 ctx->type = typdatum->value; 1385 1386 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid); 1387 if (rc) 1388 goto out; 1389 1390 rc = -EINVAL; 1391 if ((p - scontext) < scontext_len) 1392 goto out; 1393 1394 /* Check the validity of the new context. */ 1395 if (!policydb_context_isvalid(pol, ctx)) 1396 goto out; 1397 rc = 0; 1398 out: 1399 if (rc) 1400 context_destroy(ctx); 1401 return rc; 1402 } 1403 1404 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1405 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1406 int force) 1407 { 1408 char *scontext2, *str = NULL; 1409 struct context context; 1410 int rc = 0; 1411 1412 /* An empty security context is never valid. */ 1413 if (!scontext_len) 1414 return -EINVAL; 1415 1416 if (!ss_initialized) { 1417 int i; 1418 1419 for (i = 1; i < SECINITSID_NUM; i++) { 1420 if (!strcmp(initial_sid_to_string[i], scontext)) { 1421 *sid = i; 1422 return 0; 1423 } 1424 } 1425 *sid = SECINITSID_KERNEL; 1426 return 0; 1427 } 1428 *sid = SECSID_NULL; 1429 1430 /* Copy the string so that we can modify the copy as we parse it. */ 1431 scontext2 = kmalloc(scontext_len + 1, gfp_flags); 1432 if (!scontext2) 1433 return -ENOMEM; 1434 memcpy(scontext2, scontext, scontext_len); 1435 scontext2[scontext_len] = 0; 1436 1437 if (force) { 1438 /* Save another copy for storing in uninterpreted form */ 1439 rc = -ENOMEM; 1440 str = kstrdup(scontext2, gfp_flags); 1441 if (!str) 1442 goto out; 1443 } 1444 1445 read_lock(&policy_rwlock); 1446 rc = string_to_context_struct(&policydb, &sidtab, scontext2, 1447 scontext_len, &context, def_sid); 1448 if (rc == -EINVAL && force) { 1449 context.str = str; 1450 context.len = scontext_len; 1451 str = NULL; 1452 } else if (rc) 1453 goto out_unlock; 1454 rc = sidtab_context_to_sid(&sidtab, &context, sid); 1455 context_destroy(&context); 1456 out_unlock: 1457 read_unlock(&policy_rwlock); 1458 out: 1459 kfree(scontext2); 1460 kfree(str); 1461 return rc; 1462 } 1463 1464 /** 1465 * security_context_to_sid - Obtain a SID for a given security context. 1466 * @scontext: security context 1467 * @scontext_len: length in bytes 1468 * @sid: security identifier, SID 1469 * @gfp: context for the allocation 1470 * 1471 * Obtains a SID associated with the security context that 1472 * has the string representation specified by @scontext. 1473 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1474 * memory is available, or 0 on success. 1475 */ 1476 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1477 gfp_t gfp) 1478 { 1479 return security_context_to_sid_core(scontext, scontext_len, 1480 sid, SECSID_NULL, gfp, 0); 1481 } 1482 1483 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1484 { 1485 return security_context_to_sid(scontext, strlen(scontext), sid, gfp); 1486 } 1487 1488 /** 1489 * security_context_to_sid_default - Obtain a SID for a given security context, 1490 * falling back to specified default if needed. 1491 * 1492 * @scontext: security context 1493 * @scontext_len: length in bytes 1494 * @sid: security identifier, SID 1495 * @def_sid: default SID to assign on error 1496 * 1497 * Obtains a SID associated with the security context that 1498 * has the string representation specified by @scontext. 1499 * The default SID is passed to the MLS layer to be used to allow 1500 * kernel labeling of the MLS field if the MLS field is not present 1501 * (for upgrading to MLS without full relabel). 1502 * Implicitly forces adding of the context even if it cannot be mapped yet. 1503 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1504 * memory is available, or 0 on success. 1505 */ 1506 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1507 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1508 { 1509 return security_context_to_sid_core(scontext, scontext_len, 1510 sid, def_sid, gfp_flags, 1); 1511 } 1512 1513 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1514 u32 *sid) 1515 { 1516 return security_context_to_sid_core(scontext, scontext_len, 1517 sid, SECSID_NULL, GFP_KERNEL, 1); 1518 } 1519 1520 static int compute_sid_handle_invalid_context( 1521 struct context *scontext, 1522 struct context *tcontext, 1523 u16 tclass, 1524 struct context *newcontext) 1525 { 1526 char *s = NULL, *t = NULL, *n = NULL; 1527 u32 slen, tlen, nlen; 1528 1529 if (context_struct_to_string(scontext, &s, &slen)) 1530 goto out; 1531 if (context_struct_to_string(tcontext, &t, &tlen)) 1532 goto out; 1533 if (context_struct_to_string(newcontext, &n, &nlen)) 1534 goto out; 1535 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 1536 "op=security_compute_sid invalid_context=%s" 1537 " scontext=%s" 1538 " tcontext=%s" 1539 " tclass=%s", 1540 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 1541 out: 1542 kfree(s); 1543 kfree(t); 1544 kfree(n); 1545 if (!selinux_enforcing) 1546 return 0; 1547 return -EACCES; 1548 } 1549 1550 static void filename_compute_type(struct policydb *p, struct context *newcontext, 1551 u32 stype, u32 ttype, u16 tclass, 1552 const char *objname) 1553 { 1554 struct filename_trans ft; 1555 struct filename_trans_datum *otype; 1556 1557 /* 1558 * Most filename trans rules are going to live in specific directories 1559 * like /dev or /var/run. This bitmap will quickly skip rule searches 1560 * if the ttype does not contain any rules. 1561 */ 1562 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype)) 1563 return; 1564 1565 ft.stype = stype; 1566 ft.ttype = ttype; 1567 ft.tclass = tclass; 1568 ft.name = objname; 1569 1570 otype = hashtab_search(p->filename_trans, &ft); 1571 if (otype) 1572 newcontext->type = otype->otype; 1573 } 1574 1575 static int security_compute_sid(u32 ssid, 1576 u32 tsid, 1577 u16 orig_tclass, 1578 u32 specified, 1579 const char *objname, 1580 u32 *out_sid, 1581 bool kern) 1582 { 1583 struct class_datum *cladatum = NULL; 1584 struct context *scontext = NULL, *tcontext = NULL, newcontext; 1585 struct role_trans *roletr = NULL; 1586 struct avtab_key avkey; 1587 struct avtab_datum *avdatum; 1588 struct avtab_node *node; 1589 u16 tclass; 1590 int rc = 0; 1591 bool sock; 1592 1593 if (!ss_initialized) { 1594 switch (orig_tclass) { 1595 case SECCLASS_PROCESS: /* kernel value */ 1596 *out_sid = ssid; 1597 break; 1598 default: 1599 *out_sid = tsid; 1600 break; 1601 } 1602 goto out; 1603 } 1604 1605 context_init(&newcontext); 1606 1607 read_lock(&policy_rwlock); 1608 1609 if (kern) { 1610 tclass = unmap_class(orig_tclass); 1611 sock = security_is_socket_class(orig_tclass); 1612 } else { 1613 tclass = orig_tclass; 1614 sock = security_is_socket_class(map_class(tclass)); 1615 } 1616 1617 scontext = sidtab_search(&sidtab, ssid); 1618 if (!scontext) { 1619 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1620 __func__, ssid); 1621 rc = -EINVAL; 1622 goto out_unlock; 1623 } 1624 tcontext = sidtab_search(&sidtab, tsid); 1625 if (!tcontext) { 1626 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1627 __func__, tsid); 1628 rc = -EINVAL; 1629 goto out_unlock; 1630 } 1631 1632 if (tclass && tclass <= policydb.p_classes.nprim) 1633 cladatum = policydb.class_val_to_struct[tclass - 1]; 1634 1635 /* Set the user identity. */ 1636 switch (specified) { 1637 case AVTAB_TRANSITION: 1638 case AVTAB_CHANGE: 1639 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1640 newcontext.user = tcontext->user; 1641 } else { 1642 /* notice this gets both DEFAULT_SOURCE and unset */ 1643 /* Use the process user identity. */ 1644 newcontext.user = scontext->user; 1645 } 1646 break; 1647 case AVTAB_MEMBER: 1648 /* Use the related object owner. */ 1649 newcontext.user = tcontext->user; 1650 break; 1651 } 1652 1653 /* Set the role to default values. */ 1654 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1655 newcontext.role = scontext->role; 1656 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1657 newcontext.role = tcontext->role; 1658 } else { 1659 if ((tclass == policydb.process_class) || (sock == true)) 1660 newcontext.role = scontext->role; 1661 else 1662 newcontext.role = OBJECT_R_VAL; 1663 } 1664 1665 /* Set the type to default values. */ 1666 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1667 newcontext.type = scontext->type; 1668 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1669 newcontext.type = tcontext->type; 1670 } else { 1671 if ((tclass == policydb.process_class) || (sock == true)) { 1672 /* Use the type of process. */ 1673 newcontext.type = scontext->type; 1674 } else { 1675 /* Use the type of the related object. */ 1676 newcontext.type = tcontext->type; 1677 } 1678 } 1679 1680 /* Look for a type transition/member/change rule. */ 1681 avkey.source_type = scontext->type; 1682 avkey.target_type = tcontext->type; 1683 avkey.target_class = tclass; 1684 avkey.specified = specified; 1685 avdatum = avtab_search(&policydb.te_avtab, &avkey); 1686 1687 /* If no permanent rule, also check for enabled conditional rules */ 1688 if (!avdatum) { 1689 node = avtab_search_node(&policydb.te_cond_avtab, &avkey); 1690 for (; node; node = avtab_search_node_next(node, specified)) { 1691 if (node->key.specified & AVTAB_ENABLED) { 1692 avdatum = &node->datum; 1693 break; 1694 } 1695 } 1696 } 1697 1698 if (avdatum) { 1699 /* Use the type from the type transition/member/change rule. */ 1700 newcontext.type = avdatum->u.data; 1701 } 1702 1703 /* if we have a objname this is a file trans check so check those rules */ 1704 if (objname) 1705 filename_compute_type(&policydb, &newcontext, scontext->type, 1706 tcontext->type, tclass, objname); 1707 1708 /* Check for class-specific changes. */ 1709 if (specified & AVTAB_TRANSITION) { 1710 /* Look for a role transition rule. */ 1711 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) { 1712 if ((roletr->role == scontext->role) && 1713 (roletr->type == tcontext->type) && 1714 (roletr->tclass == tclass)) { 1715 /* Use the role transition rule. */ 1716 newcontext.role = roletr->new_role; 1717 break; 1718 } 1719 } 1720 } 1721 1722 /* Set the MLS attributes. 1723 This is done last because it may allocate memory. */ 1724 rc = mls_compute_sid(scontext, tcontext, tclass, specified, 1725 &newcontext, sock); 1726 if (rc) 1727 goto out_unlock; 1728 1729 /* Check the validity of the context. */ 1730 if (!policydb_context_isvalid(&policydb, &newcontext)) { 1731 rc = compute_sid_handle_invalid_context(scontext, 1732 tcontext, 1733 tclass, 1734 &newcontext); 1735 if (rc) 1736 goto out_unlock; 1737 } 1738 /* Obtain the sid for the context. */ 1739 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); 1740 out_unlock: 1741 read_unlock(&policy_rwlock); 1742 context_destroy(&newcontext); 1743 out: 1744 return rc; 1745 } 1746 1747 /** 1748 * security_transition_sid - Compute the SID for a new subject/object. 1749 * @ssid: source security identifier 1750 * @tsid: target security identifier 1751 * @tclass: target security class 1752 * @out_sid: security identifier for new subject/object 1753 * 1754 * Compute a SID to use for labeling a new subject or object in the 1755 * class @tclass based on a SID pair (@ssid, @tsid). 1756 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1757 * if insufficient memory is available, or %0 if the new SID was 1758 * computed successfully. 1759 */ 1760 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1761 const struct qstr *qstr, u32 *out_sid) 1762 { 1763 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1764 qstr ? qstr->name : NULL, out_sid, true); 1765 } 1766 1767 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1768 const char *objname, u32 *out_sid) 1769 { 1770 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1771 objname, out_sid, false); 1772 } 1773 1774 /** 1775 * security_member_sid - Compute the SID for member selection. 1776 * @ssid: source security identifier 1777 * @tsid: target security identifier 1778 * @tclass: target security class 1779 * @out_sid: security identifier for selected member 1780 * 1781 * Compute a SID to use when selecting a member of a polyinstantiated 1782 * object of class @tclass based on a SID pair (@ssid, @tsid). 1783 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1784 * if insufficient memory is available, or %0 if the SID was 1785 * computed successfully. 1786 */ 1787 int security_member_sid(u32 ssid, 1788 u32 tsid, 1789 u16 tclass, 1790 u32 *out_sid) 1791 { 1792 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL, 1793 out_sid, false); 1794 } 1795 1796 /** 1797 * security_change_sid - Compute the SID for object relabeling. 1798 * @ssid: source security identifier 1799 * @tsid: target security identifier 1800 * @tclass: target security class 1801 * @out_sid: security identifier for selected member 1802 * 1803 * Compute a SID to use for relabeling an object of class @tclass 1804 * based on a SID pair (@ssid, @tsid). 1805 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1806 * if insufficient memory is available, or %0 if the SID was 1807 * computed successfully. 1808 */ 1809 int security_change_sid(u32 ssid, 1810 u32 tsid, 1811 u16 tclass, 1812 u32 *out_sid) 1813 { 1814 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1815 out_sid, false); 1816 } 1817 1818 /* Clone the SID into the new SID table. */ 1819 static int clone_sid(u32 sid, 1820 struct context *context, 1821 void *arg) 1822 { 1823 struct sidtab *s = arg; 1824 1825 if (sid > SECINITSID_NUM) 1826 return sidtab_insert(s, sid, context); 1827 else 1828 return 0; 1829 } 1830 1831 static inline int convert_context_handle_invalid_context(struct context *context) 1832 { 1833 char *s; 1834 u32 len; 1835 1836 if (selinux_enforcing) 1837 return -EINVAL; 1838 1839 if (!context_struct_to_string(context, &s, &len)) { 1840 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s); 1841 kfree(s); 1842 } 1843 return 0; 1844 } 1845 1846 struct convert_context_args { 1847 struct policydb *oldp; 1848 struct policydb *newp; 1849 }; 1850 1851 /* 1852 * Convert the values in the security context 1853 * structure `c' from the values specified 1854 * in the policy `p->oldp' to the values specified 1855 * in the policy `p->newp'. Verify that the 1856 * context is valid under the new policy. 1857 */ 1858 static int convert_context(u32 key, 1859 struct context *c, 1860 void *p) 1861 { 1862 struct convert_context_args *args; 1863 struct context oldc; 1864 struct ocontext *oc; 1865 struct mls_range *range; 1866 struct role_datum *role; 1867 struct type_datum *typdatum; 1868 struct user_datum *usrdatum; 1869 char *s; 1870 u32 len; 1871 int rc = 0; 1872 1873 if (key <= SECINITSID_NUM) 1874 goto out; 1875 1876 args = p; 1877 1878 if (c->str) { 1879 struct context ctx; 1880 1881 rc = -ENOMEM; 1882 s = kstrdup(c->str, GFP_KERNEL); 1883 if (!s) 1884 goto out; 1885 1886 rc = string_to_context_struct(args->newp, NULL, s, 1887 c->len, &ctx, SECSID_NULL); 1888 kfree(s); 1889 if (!rc) { 1890 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n", 1891 c->str); 1892 /* Replace string with mapped representation. */ 1893 kfree(c->str); 1894 memcpy(c, &ctx, sizeof(*c)); 1895 goto out; 1896 } else if (rc == -EINVAL) { 1897 /* Retain string representation for later mapping. */ 1898 rc = 0; 1899 goto out; 1900 } else { 1901 /* Other error condition, e.g. ENOMEM. */ 1902 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n", 1903 c->str, -rc); 1904 goto out; 1905 } 1906 } 1907 1908 rc = context_cpy(&oldc, c); 1909 if (rc) 1910 goto out; 1911 1912 /* Convert the user. */ 1913 rc = -EINVAL; 1914 usrdatum = hashtab_search(args->newp->p_users.table, 1915 sym_name(args->oldp, SYM_USERS, c->user - 1)); 1916 if (!usrdatum) 1917 goto bad; 1918 c->user = usrdatum->value; 1919 1920 /* Convert the role. */ 1921 rc = -EINVAL; 1922 role = hashtab_search(args->newp->p_roles.table, 1923 sym_name(args->oldp, SYM_ROLES, c->role - 1)); 1924 if (!role) 1925 goto bad; 1926 c->role = role->value; 1927 1928 /* Convert the type. */ 1929 rc = -EINVAL; 1930 typdatum = hashtab_search(args->newp->p_types.table, 1931 sym_name(args->oldp, SYM_TYPES, c->type - 1)); 1932 if (!typdatum) 1933 goto bad; 1934 c->type = typdatum->value; 1935 1936 /* Convert the MLS fields if dealing with MLS policies */ 1937 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 1938 rc = mls_convert_context(args->oldp, args->newp, c); 1939 if (rc) 1940 goto bad; 1941 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) { 1942 /* 1943 * Switching between MLS and non-MLS policy: 1944 * free any storage used by the MLS fields in the 1945 * context for all existing entries in the sidtab. 1946 */ 1947 mls_context_destroy(c); 1948 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 1949 /* 1950 * Switching between non-MLS and MLS policy: 1951 * ensure that the MLS fields of the context for all 1952 * existing entries in the sidtab are filled in with a 1953 * suitable default value, likely taken from one of the 1954 * initial SIDs. 1955 */ 1956 oc = args->newp->ocontexts[OCON_ISID]; 1957 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 1958 oc = oc->next; 1959 rc = -EINVAL; 1960 if (!oc) { 1961 printk(KERN_ERR "SELinux: unable to look up" 1962 " the initial SIDs list\n"); 1963 goto bad; 1964 } 1965 range = &oc->context[0].range; 1966 rc = mls_range_set(c, range); 1967 if (rc) 1968 goto bad; 1969 } 1970 1971 /* Check the validity of the new context. */ 1972 if (!policydb_context_isvalid(args->newp, c)) { 1973 rc = convert_context_handle_invalid_context(&oldc); 1974 if (rc) 1975 goto bad; 1976 } 1977 1978 context_destroy(&oldc); 1979 1980 rc = 0; 1981 out: 1982 return rc; 1983 bad: 1984 /* Map old representation to string and save it. */ 1985 rc = context_struct_to_string(&oldc, &s, &len); 1986 if (rc) 1987 return rc; 1988 context_destroy(&oldc); 1989 context_destroy(c); 1990 c->str = s; 1991 c->len = len; 1992 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n", 1993 c->str); 1994 rc = 0; 1995 goto out; 1996 } 1997 1998 static void security_load_policycaps(void) 1999 { 2000 unsigned int i; 2001 struct ebitmap_node *node; 2002 2003 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps, 2004 POLICYDB_CAPABILITY_NETPEER); 2005 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps, 2006 POLICYDB_CAPABILITY_OPENPERM); 2007 selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps, 2008 POLICYDB_CAPABILITY_EXTSOCKCLASS); 2009 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps, 2010 POLICYDB_CAPABILITY_ALWAYSNETWORK); 2011 selinux_policycap_cgroupseclabel = 2012 ebitmap_get_bit(&policydb.policycaps, 2013 POLICYDB_CAPABILITY_CGROUPSECLABEL); 2014 selinux_policycap_nnp_nosuid_transition = 2015 ebitmap_get_bit(&policydb.policycaps, 2016 POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION); 2017 2018 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2019 pr_info("SELinux: policy capability %s=%d\n", 2020 selinux_policycap_names[i], 2021 ebitmap_get_bit(&policydb.policycaps, i)); 2022 2023 ebitmap_for_each_positive_bit(&policydb.policycaps, node, i) { 2024 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2025 pr_info("SELinux: unknown policy capability %u\n", 2026 i); 2027 } 2028 } 2029 2030 static int security_preserve_bools(struct policydb *p); 2031 2032 /** 2033 * security_load_policy - Load a security policy configuration. 2034 * @data: binary policy data 2035 * @len: length of data in bytes 2036 * 2037 * Load a new set of security policy configuration data, 2038 * validate it and convert the SID table as necessary. 2039 * This function will flush the access vector cache after 2040 * loading the new policy. 2041 */ 2042 int security_load_policy(void *data, size_t len) 2043 { 2044 struct policydb *oldpolicydb, *newpolicydb; 2045 struct sidtab oldsidtab, newsidtab; 2046 struct selinux_mapping *oldmap, *map = NULL; 2047 struct convert_context_args args; 2048 u32 seqno; 2049 u16 map_size; 2050 int rc = 0; 2051 struct policy_file file = { data, len }, *fp = &file; 2052 2053 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL); 2054 if (!oldpolicydb) { 2055 rc = -ENOMEM; 2056 goto out; 2057 } 2058 newpolicydb = oldpolicydb + 1; 2059 2060 if (!ss_initialized) { 2061 avtab_cache_init(); 2062 ebitmap_cache_init(); 2063 hashtab_cache_init(); 2064 rc = policydb_read(&policydb, fp); 2065 if (rc) { 2066 avtab_cache_destroy(); 2067 ebitmap_cache_destroy(); 2068 hashtab_cache_destroy(); 2069 goto out; 2070 } 2071 2072 policydb.len = len; 2073 rc = selinux_set_mapping(&policydb, secclass_map, 2074 ¤t_mapping, 2075 ¤t_mapping_size); 2076 if (rc) { 2077 policydb_destroy(&policydb); 2078 avtab_cache_destroy(); 2079 ebitmap_cache_destroy(); 2080 hashtab_cache_destroy(); 2081 goto out; 2082 } 2083 2084 rc = policydb_load_isids(&policydb, &sidtab); 2085 if (rc) { 2086 policydb_destroy(&policydb); 2087 avtab_cache_destroy(); 2088 ebitmap_cache_destroy(); 2089 hashtab_cache_destroy(); 2090 goto out; 2091 } 2092 2093 security_load_policycaps(); 2094 ss_initialized = 1; 2095 seqno = ++latest_granting; 2096 selinux_complete_init(); 2097 avc_ss_reset(seqno); 2098 selnl_notify_policyload(seqno); 2099 selinux_status_update_policyload(seqno); 2100 selinux_netlbl_cache_invalidate(); 2101 selinux_xfrm_notify_policyload(); 2102 goto out; 2103 } 2104 2105 #if 0 2106 sidtab_hash_eval(&sidtab, "sids"); 2107 #endif 2108 2109 rc = policydb_read(newpolicydb, fp); 2110 if (rc) 2111 goto out; 2112 2113 newpolicydb->len = len; 2114 /* If switching between different policy types, log MLS status */ 2115 if (policydb.mls_enabled && !newpolicydb->mls_enabled) 2116 printk(KERN_INFO "SELinux: Disabling MLS support...\n"); 2117 else if (!policydb.mls_enabled && newpolicydb->mls_enabled) 2118 printk(KERN_INFO "SELinux: Enabling MLS support...\n"); 2119 2120 rc = policydb_load_isids(newpolicydb, &newsidtab); 2121 if (rc) { 2122 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n"); 2123 policydb_destroy(newpolicydb); 2124 goto out; 2125 } 2126 2127 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size); 2128 if (rc) 2129 goto err; 2130 2131 rc = security_preserve_bools(newpolicydb); 2132 if (rc) { 2133 printk(KERN_ERR "SELinux: unable to preserve booleans\n"); 2134 goto err; 2135 } 2136 2137 /* Clone the SID table. */ 2138 sidtab_shutdown(&sidtab); 2139 2140 rc = sidtab_map(&sidtab, clone_sid, &newsidtab); 2141 if (rc) 2142 goto err; 2143 2144 /* 2145 * Convert the internal representations of contexts 2146 * in the new SID table. 2147 */ 2148 args.oldp = &policydb; 2149 args.newp = newpolicydb; 2150 rc = sidtab_map(&newsidtab, convert_context, &args); 2151 if (rc) { 2152 printk(KERN_ERR "SELinux: unable to convert the internal" 2153 " representation of contexts in the new SID" 2154 " table\n"); 2155 goto err; 2156 } 2157 2158 /* Save the old policydb and SID table to free later. */ 2159 memcpy(oldpolicydb, &policydb, sizeof(policydb)); 2160 sidtab_set(&oldsidtab, &sidtab); 2161 2162 /* Install the new policydb and SID table. */ 2163 write_lock_irq(&policy_rwlock); 2164 memcpy(&policydb, newpolicydb, sizeof(policydb)); 2165 sidtab_set(&sidtab, &newsidtab); 2166 security_load_policycaps(); 2167 oldmap = current_mapping; 2168 current_mapping = map; 2169 current_mapping_size = map_size; 2170 seqno = ++latest_granting; 2171 write_unlock_irq(&policy_rwlock); 2172 2173 /* Free the old policydb and SID table. */ 2174 policydb_destroy(oldpolicydb); 2175 sidtab_destroy(&oldsidtab); 2176 kfree(oldmap); 2177 2178 avc_ss_reset(seqno); 2179 selnl_notify_policyload(seqno); 2180 selinux_status_update_policyload(seqno); 2181 selinux_netlbl_cache_invalidate(); 2182 selinux_xfrm_notify_policyload(); 2183 2184 rc = 0; 2185 goto out; 2186 2187 err: 2188 kfree(map); 2189 sidtab_destroy(&newsidtab); 2190 policydb_destroy(newpolicydb); 2191 2192 out: 2193 kfree(oldpolicydb); 2194 return rc; 2195 } 2196 2197 size_t security_policydb_len(void) 2198 { 2199 size_t len; 2200 2201 read_lock(&policy_rwlock); 2202 len = policydb.len; 2203 read_unlock(&policy_rwlock); 2204 2205 return len; 2206 } 2207 2208 /** 2209 * security_port_sid - Obtain the SID for a port. 2210 * @protocol: protocol number 2211 * @port: port number 2212 * @out_sid: security identifier 2213 */ 2214 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2215 { 2216 struct ocontext *c; 2217 int rc = 0; 2218 2219 read_lock(&policy_rwlock); 2220 2221 c = policydb.ocontexts[OCON_PORT]; 2222 while (c) { 2223 if (c->u.port.protocol == protocol && 2224 c->u.port.low_port <= port && 2225 c->u.port.high_port >= port) 2226 break; 2227 c = c->next; 2228 } 2229 2230 if (c) { 2231 if (!c->sid[0]) { 2232 rc = sidtab_context_to_sid(&sidtab, 2233 &c->context[0], 2234 &c->sid[0]); 2235 if (rc) 2236 goto out; 2237 } 2238 *out_sid = c->sid[0]; 2239 } else { 2240 *out_sid = SECINITSID_PORT; 2241 } 2242 2243 out: 2244 read_unlock(&policy_rwlock); 2245 return rc; 2246 } 2247 2248 /** 2249 * security_pkey_sid - Obtain the SID for a pkey. 2250 * @subnet_prefix: Subnet Prefix 2251 * @pkey_num: pkey number 2252 * @out_sid: security identifier 2253 */ 2254 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2255 { 2256 struct ocontext *c; 2257 int rc = 0; 2258 2259 read_lock(&policy_rwlock); 2260 2261 c = policydb.ocontexts[OCON_IBPKEY]; 2262 while (c) { 2263 if (c->u.ibpkey.low_pkey <= pkey_num && 2264 c->u.ibpkey.high_pkey >= pkey_num && 2265 c->u.ibpkey.subnet_prefix == subnet_prefix) 2266 break; 2267 2268 c = c->next; 2269 } 2270 2271 if (c) { 2272 if (!c->sid[0]) { 2273 rc = sidtab_context_to_sid(&sidtab, 2274 &c->context[0], 2275 &c->sid[0]); 2276 if (rc) 2277 goto out; 2278 } 2279 *out_sid = c->sid[0]; 2280 } else 2281 *out_sid = SECINITSID_UNLABELED; 2282 2283 out: 2284 read_unlock(&policy_rwlock); 2285 return rc; 2286 } 2287 2288 /** 2289 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2290 * @dev_name: device name 2291 * @port: port number 2292 * @out_sid: security identifier 2293 */ 2294 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) 2295 { 2296 struct ocontext *c; 2297 int rc = 0; 2298 2299 read_lock(&policy_rwlock); 2300 2301 c = policydb.ocontexts[OCON_IBENDPORT]; 2302 while (c) { 2303 if (c->u.ibendport.port == port_num && 2304 !strncmp(c->u.ibendport.dev_name, 2305 dev_name, 2306 IB_DEVICE_NAME_MAX)) 2307 break; 2308 2309 c = c->next; 2310 } 2311 2312 if (c) { 2313 if (!c->sid[0]) { 2314 rc = sidtab_context_to_sid(&sidtab, 2315 &c->context[0], 2316 &c->sid[0]); 2317 if (rc) 2318 goto out; 2319 } 2320 *out_sid = c->sid[0]; 2321 } else 2322 *out_sid = SECINITSID_UNLABELED; 2323 2324 out: 2325 read_unlock(&policy_rwlock); 2326 return rc; 2327 } 2328 2329 /** 2330 * security_netif_sid - Obtain the SID for a network interface. 2331 * @name: interface name 2332 * @if_sid: interface SID 2333 */ 2334 int security_netif_sid(char *name, u32 *if_sid) 2335 { 2336 int rc = 0; 2337 struct ocontext *c; 2338 2339 read_lock(&policy_rwlock); 2340 2341 c = policydb.ocontexts[OCON_NETIF]; 2342 while (c) { 2343 if (strcmp(name, c->u.name) == 0) 2344 break; 2345 c = c->next; 2346 } 2347 2348 if (c) { 2349 if (!c->sid[0] || !c->sid[1]) { 2350 rc = sidtab_context_to_sid(&sidtab, 2351 &c->context[0], 2352 &c->sid[0]); 2353 if (rc) 2354 goto out; 2355 rc = sidtab_context_to_sid(&sidtab, 2356 &c->context[1], 2357 &c->sid[1]); 2358 if (rc) 2359 goto out; 2360 } 2361 *if_sid = c->sid[0]; 2362 } else 2363 *if_sid = SECINITSID_NETIF; 2364 2365 out: 2366 read_unlock(&policy_rwlock); 2367 return rc; 2368 } 2369 2370 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2371 { 2372 int i, fail = 0; 2373 2374 for (i = 0; i < 4; i++) 2375 if (addr[i] != (input[i] & mask[i])) { 2376 fail = 1; 2377 break; 2378 } 2379 2380 return !fail; 2381 } 2382 2383 /** 2384 * security_node_sid - Obtain the SID for a node (host). 2385 * @domain: communication domain aka address family 2386 * @addrp: address 2387 * @addrlen: address length in bytes 2388 * @out_sid: security identifier 2389 */ 2390 int security_node_sid(u16 domain, 2391 void *addrp, 2392 u32 addrlen, 2393 u32 *out_sid) 2394 { 2395 int rc; 2396 struct ocontext *c; 2397 2398 read_lock(&policy_rwlock); 2399 2400 switch (domain) { 2401 case AF_INET: { 2402 u32 addr; 2403 2404 rc = -EINVAL; 2405 if (addrlen != sizeof(u32)) 2406 goto out; 2407 2408 addr = *((u32 *)addrp); 2409 2410 c = policydb.ocontexts[OCON_NODE]; 2411 while (c) { 2412 if (c->u.node.addr == (addr & c->u.node.mask)) 2413 break; 2414 c = c->next; 2415 } 2416 break; 2417 } 2418 2419 case AF_INET6: 2420 rc = -EINVAL; 2421 if (addrlen != sizeof(u64) * 2) 2422 goto out; 2423 c = policydb.ocontexts[OCON_NODE6]; 2424 while (c) { 2425 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2426 c->u.node6.mask)) 2427 break; 2428 c = c->next; 2429 } 2430 break; 2431 2432 default: 2433 rc = 0; 2434 *out_sid = SECINITSID_NODE; 2435 goto out; 2436 } 2437 2438 if (c) { 2439 if (!c->sid[0]) { 2440 rc = sidtab_context_to_sid(&sidtab, 2441 &c->context[0], 2442 &c->sid[0]); 2443 if (rc) 2444 goto out; 2445 } 2446 *out_sid = c->sid[0]; 2447 } else { 2448 *out_sid = SECINITSID_NODE; 2449 } 2450 2451 rc = 0; 2452 out: 2453 read_unlock(&policy_rwlock); 2454 return rc; 2455 } 2456 2457 #define SIDS_NEL 25 2458 2459 /** 2460 * security_get_user_sids - Obtain reachable SIDs for a user. 2461 * @fromsid: starting SID 2462 * @username: username 2463 * @sids: array of reachable SIDs for user 2464 * @nel: number of elements in @sids 2465 * 2466 * Generate the set of SIDs for legal security contexts 2467 * for a given user that can be reached by @fromsid. 2468 * Set *@sids to point to a dynamically allocated 2469 * array containing the set of SIDs. Set *@nel to the 2470 * number of elements in the array. 2471 */ 2472 2473 int security_get_user_sids(u32 fromsid, 2474 char *username, 2475 u32 **sids, 2476 u32 *nel) 2477 { 2478 struct context *fromcon, usercon; 2479 u32 *mysids = NULL, *mysids2, sid; 2480 u32 mynel = 0, maxnel = SIDS_NEL; 2481 struct user_datum *user; 2482 struct role_datum *role; 2483 struct ebitmap_node *rnode, *tnode; 2484 int rc = 0, i, j; 2485 2486 *sids = NULL; 2487 *nel = 0; 2488 2489 if (!ss_initialized) 2490 goto out; 2491 2492 read_lock(&policy_rwlock); 2493 2494 context_init(&usercon); 2495 2496 rc = -EINVAL; 2497 fromcon = sidtab_search(&sidtab, fromsid); 2498 if (!fromcon) 2499 goto out_unlock; 2500 2501 rc = -EINVAL; 2502 user = hashtab_search(policydb.p_users.table, username); 2503 if (!user) 2504 goto out_unlock; 2505 2506 usercon.user = user->value; 2507 2508 rc = -ENOMEM; 2509 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); 2510 if (!mysids) 2511 goto out_unlock; 2512 2513 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2514 role = policydb.role_val_to_struct[i]; 2515 usercon.role = i + 1; 2516 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2517 usercon.type = j + 1; 2518 2519 if (mls_setup_user_range(fromcon, user, &usercon)) 2520 continue; 2521 2522 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); 2523 if (rc) 2524 goto out_unlock; 2525 if (mynel < maxnel) { 2526 mysids[mynel++] = sid; 2527 } else { 2528 rc = -ENOMEM; 2529 maxnel += SIDS_NEL; 2530 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2531 if (!mysids2) 2532 goto out_unlock; 2533 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2534 kfree(mysids); 2535 mysids = mysids2; 2536 mysids[mynel++] = sid; 2537 } 2538 } 2539 } 2540 rc = 0; 2541 out_unlock: 2542 read_unlock(&policy_rwlock); 2543 if (rc || !mynel) { 2544 kfree(mysids); 2545 goto out; 2546 } 2547 2548 rc = -ENOMEM; 2549 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2550 if (!mysids2) { 2551 kfree(mysids); 2552 goto out; 2553 } 2554 for (i = 0, j = 0; i < mynel; i++) { 2555 struct av_decision dummy_avd; 2556 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2557 SECCLASS_PROCESS, /* kernel value */ 2558 PROCESS__TRANSITION, AVC_STRICT, 2559 &dummy_avd); 2560 if (!rc) 2561 mysids2[j++] = mysids[i]; 2562 cond_resched(); 2563 } 2564 rc = 0; 2565 kfree(mysids); 2566 *sids = mysids2; 2567 *nel = j; 2568 out: 2569 return rc; 2570 } 2571 2572 /** 2573 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2574 * @fstype: filesystem type 2575 * @path: path from root of mount 2576 * @sclass: file security class 2577 * @sid: SID for path 2578 * 2579 * Obtain a SID to use for a file in a filesystem that 2580 * cannot support xattr or use a fixed labeling behavior like 2581 * transition SIDs or task SIDs. 2582 * 2583 * The caller must acquire the policy_rwlock before calling this function. 2584 */ 2585 static inline int __security_genfs_sid(const char *fstype, 2586 char *path, 2587 u16 orig_sclass, 2588 u32 *sid) 2589 { 2590 int len; 2591 u16 sclass; 2592 struct genfs *genfs; 2593 struct ocontext *c; 2594 int rc, cmp = 0; 2595 2596 while (path[0] == '/' && path[1] == '/') 2597 path++; 2598 2599 sclass = unmap_class(orig_sclass); 2600 *sid = SECINITSID_UNLABELED; 2601 2602 for (genfs = policydb.genfs; genfs; genfs = genfs->next) { 2603 cmp = strcmp(fstype, genfs->fstype); 2604 if (cmp <= 0) 2605 break; 2606 } 2607 2608 rc = -ENOENT; 2609 if (!genfs || cmp) 2610 goto out; 2611 2612 for (c = genfs->head; c; c = c->next) { 2613 len = strlen(c->u.name); 2614 if ((!c->v.sclass || sclass == c->v.sclass) && 2615 (strncmp(c->u.name, path, len) == 0)) 2616 break; 2617 } 2618 2619 rc = -ENOENT; 2620 if (!c) 2621 goto out; 2622 2623 if (!c->sid[0]) { 2624 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); 2625 if (rc) 2626 goto out; 2627 } 2628 2629 *sid = c->sid[0]; 2630 rc = 0; 2631 out: 2632 return rc; 2633 } 2634 2635 /** 2636 * security_genfs_sid - Obtain a SID for a file in a filesystem 2637 * @fstype: filesystem type 2638 * @path: path from root of mount 2639 * @sclass: file security class 2640 * @sid: SID for path 2641 * 2642 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2643 * it afterward. 2644 */ 2645 int security_genfs_sid(const char *fstype, 2646 char *path, 2647 u16 orig_sclass, 2648 u32 *sid) 2649 { 2650 int retval; 2651 2652 read_lock(&policy_rwlock); 2653 retval = __security_genfs_sid(fstype, path, orig_sclass, sid); 2654 read_unlock(&policy_rwlock); 2655 return retval; 2656 } 2657 2658 /** 2659 * security_fs_use - Determine how to handle labeling for a filesystem. 2660 * @sb: superblock in question 2661 */ 2662 int security_fs_use(struct super_block *sb) 2663 { 2664 int rc = 0; 2665 struct ocontext *c; 2666 struct superblock_security_struct *sbsec = sb->s_security; 2667 const char *fstype = sb->s_type->name; 2668 2669 read_lock(&policy_rwlock); 2670 2671 c = policydb.ocontexts[OCON_FSUSE]; 2672 while (c) { 2673 if (strcmp(fstype, c->u.name) == 0) 2674 break; 2675 c = c->next; 2676 } 2677 2678 if (c) { 2679 sbsec->behavior = c->v.behavior; 2680 if (!c->sid[0]) { 2681 rc = sidtab_context_to_sid(&sidtab, &c->context[0], 2682 &c->sid[0]); 2683 if (rc) 2684 goto out; 2685 } 2686 sbsec->sid = c->sid[0]; 2687 } else { 2688 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR, 2689 &sbsec->sid); 2690 if (rc) { 2691 sbsec->behavior = SECURITY_FS_USE_NONE; 2692 rc = 0; 2693 } else { 2694 sbsec->behavior = SECURITY_FS_USE_GENFS; 2695 } 2696 } 2697 2698 out: 2699 read_unlock(&policy_rwlock); 2700 return rc; 2701 } 2702 2703 int security_get_bools(int *len, char ***names, int **values) 2704 { 2705 int i, rc; 2706 2707 read_lock(&policy_rwlock); 2708 *names = NULL; 2709 *values = NULL; 2710 2711 rc = 0; 2712 *len = policydb.p_bools.nprim; 2713 if (!*len) 2714 goto out; 2715 2716 rc = -ENOMEM; 2717 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2718 if (!*names) 2719 goto err; 2720 2721 rc = -ENOMEM; 2722 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2723 if (!*values) 2724 goto err; 2725 2726 for (i = 0; i < *len; i++) { 2727 (*values)[i] = policydb.bool_val_to_struct[i]->state; 2728 2729 rc = -ENOMEM; 2730 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC); 2731 if (!(*names)[i]) 2732 goto err; 2733 } 2734 rc = 0; 2735 out: 2736 read_unlock(&policy_rwlock); 2737 return rc; 2738 err: 2739 if (*names) { 2740 for (i = 0; i < *len; i++) 2741 kfree((*names)[i]); 2742 } 2743 kfree(*values); 2744 goto out; 2745 } 2746 2747 2748 int security_set_bools(int len, int *values) 2749 { 2750 int i, rc; 2751 int lenp, seqno = 0; 2752 struct cond_node *cur; 2753 2754 write_lock_irq(&policy_rwlock); 2755 2756 rc = -EFAULT; 2757 lenp = policydb.p_bools.nprim; 2758 if (len != lenp) 2759 goto out; 2760 2761 for (i = 0; i < len; i++) { 2762 if (!!values[i] != policydb.bool_val_to_struct[i]->state) { 2763 audit_log(current->audit_context, GFP_ATOMIC, 2764 AUDIT_MAC_CONFIG_CHANGE, 2765 "bool=%s val=%d old_val=%d auid=%u ses=%u", 2766 sym_name(&policydb, SYM_BOOLS, i), 2767 !!values[i], 2768 policydb.bool_val_to_struct[i]->state, 2769 from_kuid(&init_user_ns, audit_get_loginuid(current)), 2770 audit_get_sessionid(current)); 2771 } 2772 if (values[i]) 2773 policydb.bool_val_to_struct[i]->state = 1; 2774 else 2775 policydb.bool_val_to_struct[i]->state = 0; 2776 } 2777 2778 for (cur = policydb.cond_list; cur; cur = cur->next) { 2779 rc = evaluate_cond_node(&policydb, cur); 2780 if (rc) 2781 goto out; 2782 } 2783 2784 seqno = ++latest_granting; 2785 rc = 0; 2786 out: 2787 write_unlock_irq(&policy_rwlock); 2788 if (!rc) { 2789 avc_ss_reset(seqno); 2790 selnl_notify_policyload(seqno); 2791 selinux_status_update_policyload(seqno); 2792 selinux_xfrm_notify_policyload(); 2793 } 2794 return rc; 2795 } 2796 2797 int security_get_bool_value(int index) 2798 { 2799 int rc; 2800 int len; 2801 2802 read_lock(&policy_rwlock); 2803 2804 rc = -EFAULT; 2805 len = policydb.p_bools.nprim; 2806 if (index >= len) 2807 goto out; 2808 2809 rc = policydb.bool_val_to_struct[index]->state; 2810 out: 2811 read_unlock(&policy_rwlock); 2812 return rc; 2813 } 2814 2815 static int security_preserve_bools(struct policydb *p) 2816 { 2817 int rc, nbools = 0, *bvalues = NULL, i; 2818 char **bnames = NULL; 2819 struct cond_bool_datum *booldatum; 2820 struct cond_node *cur; 2821 2822 rc = security_get_bools(&nbools, &bnames, &bvalues); 2823 if (rc) 2824 goto out; 2825 for (i = 0; i < nbools; i++) { 2826 booldatum = hashtab_search(p->p_bools.table, bnames[i]); 2827 if (booldatum) 2828 booldatum->state = bvalues[i]; 2829 } 2830 for (cur = p->cond_list; cur; cur = cur->next) { 2831 rc = evaluate_cond_node(p, cur); 2832 if (rc) 2833 goto out; 2834 } 2835 2836 out: 2837 if (bnames) { 2838 for (i = 0; i < nbools; i++) 2839 kfree(bnames[i]); 2840 } 2841 kfree(bnames); 2842 kfree(bvalues); 2843 return rc; 2844 } 2845 2846 /* 2847 * security_sid_mls_copy() - computes a new sid based on the given 2848 * sid and the mls portion of mls_sid. 2849 */ 2850 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 2851 { 2852 struct context *context1; 2853 struct context *context2; 2854 struct context newcon; 2855 char *s; 2856 u32 len; 2857 int rc; 2858 2859 rc = 0; 2860 if (!ss_initialized || !policydb.mls_enabled) { 2861 *new_sid = sid; 2862 goto out; 2863 } 2864 2865 context_init(&newcon); 2866 2867 read_lock(&policy_rwlock); 2868 2869 rc = -EINVAL; 2870 context1 = sidtab_search(&sidtab, sid); 2871 if (!context1) { 2872 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2873 __func__, sid); 2874 goto out_unlock; 2875 } 2876 2877 rc = -EINVAL; 2878 context2 = sidtab_search(&sidtab, mls_sid); 2879 if (!context2) { 2880 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2881 __func__, mls_sid); 2882 goto out_unlock; 2883 } 2884 2885 newcon.user = context1->user; 2886 newcon.role = context1->role; 2887 newcon.type = context1->type; 2888 rc = mls_context_cpy(&newcon, context2); 2889 if (rc) 2890 goto out_unlock; 2891 2892 /* Check the validity of the new context. */ 2893 if (!policydb_context_isvalid(&policydb, &newcon)) { 2894 rc = convert_context_handle_invalid_context(&newcon); 2895 if (rc) { 2896 if (!context_struct_to_string(&newcon, &s, &len)) { 2897 audit_log(current->audit_context, 2898 GFP_ATOMIC, AUDIT_SELINUX_ERR, 2899 "op=security_sid_mls_copy " 2900 "invalid_context=%s", s); 2901 kfree(s); 2902 } 2903 goto out_unlock; 2904 } 2905 } 2906 2907 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid); 2908 out_unlock: 2909 read_unlock(&policy_rwlock); 2910 context_destroy(&newcon); 2911 out: 2912 return rc; 2913 } 2914 2915 /** 2916 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 2917 * @nlbl_sid: NetLabel SID 2918 * @nlbl_type: NetLabel labeling protocol type 2919 * @xfrm_sid: XFRM SID 2920 * 2921 * Description: 2922 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 2923 * resolved into a single SID it is returned via @peer_sid and the function 2924 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 2925 * returns a negative value. A table summarizing the behavior is below: 2926 * 2927 * | function return | @sid 2928 * ------------------------------+-----------------+----------------- 2929 * no peer labels | 0 | SECSID_NULL 2930 * single peer label | 0 | <peer_label> 2931 * multiple, consistent labels | 0 | <peer_label> 2932 * multiple, inconsistent labels | -<errno> | SECSID_NULL 2933 * 2934 */ 2935 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 2936 u32 xfrm_sid, 2937 u32 *peer_sid) 2938 { 2939 int rc; 2940 struct context *nlbl_ctx; 2941 struct context *xfrm_ctx; 2942 2943 *peer_sid = SECSID_NULL; 2944 2945 /* handle the common (which also happens to be the set of easy) cases 2946 * right away, these two if statements catch everything involving a 2947 * single or absent peer SID/label */ 2948 if (xfrm_sid == SECSID_NULL) { 2949 *peer_sid = nlbl_sid; 2950 return 0; 2951 } 2952 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 2953 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 2954 * is present */ 2955 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 2956 *peer_sid = xfrm_sid; 2957 return 0; 2958 } 2959 2960 /* we don't need to check ss_initialized here since the only way both 2961 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 2962 * security server was initialized and ss_initialized was true */ 2963 if (!policydb.mls_enabled) 2964 return 0; 2965 2966 read_lock(&policy_rwlock); 2967 2968 rc = -EINVAL; 2969 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid); 2970 if (!nlbl_ctx) { 2971 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2972 __func__, nlbl_sid); 2973 goto out; 2974 } 2975 rc = -EINVAL; 2976 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid); 2977 if (!xfrm_ctx) { 2978 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2979 __func__, xfrm_sid); 2980 goto out; 2981 } 2982 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 2983 if (rc) 2984 goto out; 2985 2986 /* at present NetLabel SIDs/labels really only carry MLS 2987 * information so if the MLS portion of the NetLabel SID 2988 * matches the MLS portion of the labeled XFRM SID/label 2989 * then pass along the XFRM SID as it is the most 2990 * expressive */ 2991 *peer_sid = xfrm_sid; 2992 out: 2993 read_unlock(&policy_rwlock); 2994 return rc; 2995 } 2996 2997 static int get_classes_callback(void *k, void *d, void *args) 2998 { 2999 struct class_datum *datum = d; 3000 char *name = k, **classes = args; 3001 int value = datum->value - 1; 3002 3003 classes[value] = kstrdup(name, GFP_ATOMIC); 3004 if (!classes[value]) 3005 return -ENOMEM; 3006 3007 return 0; 3008 } 3009 3010 int security_get_classes(char ***classes, int *nclasses) 3011 { 3012 int rc; 3013 3014 read_lock(&policy_rwlock); 3015 3016 rc = -ENOMEM; 3017 *nclasses = policydb.p_classes.nprim; 3018 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3019 if (!*classes) 3020 goto out; 3021 3022 rc = hashtab_map(policydb.p_classes.table, get_classes_callback, 3023 *classes); 3024 if (rc) { 3025 int i; 3026 for (i = 0; i < *nclasses; i++) 3027 kfree((*classes)[i]); 3028 kfree(*classes); 3029 } 3030 3031 out: 3032 read_unlock(&policy_rwlock); 3033 return rc; 3034 } 3035 3036 static int get_permissions_callback(void *k, void *d, void *args) 3037 { 3038 struct perm_datum *datum = d; 3039 char *name = k, **perms = args; 3040 int value = datum->value - 1; 3041 3042 perms[value] = kstrdup(name, GFP_ATOMIC); 3043 if (!perms[value]) 3044 return -ENOMEM; 3045 3046 return 0; 3047 } 3048 3049 int security_get_permissions(char *class, char ***perms, int *nperms) 3050 { 3051 int rc, i; 3052 struct class_datum *match; 3053 3054 read_lock(&policy_rwlock); 3055 3056 rc = -EINVAL; 3057 match = hashtab_search(policydb.p_classes.table, class); 3058 if (!match) { 3059 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n", 3060 __func__, class); 3061 goto out; 3062 } 3063 3064 rc = -ENOMEM; 3065 *nperms = match->permissions.nprim; 3066 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3067 if (!*perms) 3068 goto out; 3069 3070 if (match->comdatum) { 3071 rc = hashtab_map(match->comdatum->permissions.table, 3072 get_permissions_callback, *perms); 3073 if (rc) 3074 goto err; 3075 } 3076 3077 rc = hashtab_map(match->permissions.table, get_permissions_callback, 3078 *perms); 3079 if (rc) 3080 goto err; 3081 3082 out: 3083 read_unlock(&policy_rwlock); 3084 return rc; 3085 3086 err: 3087 read_unlock(&policy_rwlock); 3088 for (i = 0; i < *nperms; i++) 3089 kfree((*perms)[i]); 3090 kfree(*perms); 3091 return rc; 3092 } 3093 3094 int security_get_reject_unknown(void) 3095 { 3096 return policydb.reject_unknown; 3097 } 3098 3099 int security_get_allow_unknown(void) 3100 { 3101 return policydb.allow_unknown; 3102 } 3103 3104 /** 3105 * security_policycap_supported - Check for a specific policy capability 3106 * @req_cap: capability 3107 * 3108 * Description: 3109 * This function queries the currently loaded policy to see if it supports the 3110 * capability specified by @req_cap. Returns true (1) if the capability is 3111 * supported, false (0) if it isn't supported. 3112 * 3113 */ 3114 int security_policycap_supported(unsigned int req_cap) 3115 { 3116 int rc; 3117 3118 read_lock(&policy_rwlock); 3119 rc = ebitmap_get_bit(&policydb.policycaps, req_cap); 3120 read_unlock(&policy_rwlock); 3121 3122 return rc; 3123 } 3124 3125 struct selinux_audit_rule { 3126 u32 au_seqno; 3127 struct context au_ctxt; 3128 }; 3129 3130 void selinux_audit_rule_free(void *vrule) 3131 { 3132 struct selinux_audit_rule *rule = vrule; 3133 3134 if (rule) { 3135 context_destroy(&rule->au_ctxt); 3136 kfree(rule); 3137 } 3138 } 3139 3140 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3141 { 3142 struct selinux_audit_rule *tmprule; 3143 struct role_datum *roledatum; 3144 struct type_datum *typedatum; 3145 struct user_datum *userdatum; 3146 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3147 int rc = 0; 3148 3149 *rule = NULL; 3150 3151 if (!ss_initialized) 3152 return -EOPNOTSUPP; 3153 3154 switch (field) { 3155 case AUDIT_SUBJ_USER: 3156 case AUDIT_SUBJ_ROLE: 3157 case AUDIT_SUBJ_TYPE: 3158 case AUDIT_OBJ_USER: 3159 case AUDIT_OBJ_ROLE: 3160 case AUDIT_OBJ_TYPE: 3161 /* only 'equals' and 'not equals' fit user, role, and type */ 3162 if (op != Audit_equal && op != Audit_not_equal) 3163 return -EINVAL; 3164 break; 3165 case AUDIT_SUBJ_SEN: 3166 case AUDIT_SUBJ_CLR: 3167 case AUDIT_OBJ_LEV_LOW: 3168 case AUDIT_OBJ_LEV_HIGH: 3169 /* we do not allow a range, indicated by the presence of '-' */ 3170 if (strchr(rulestr, '-')) 3171 return -EINVAL; 3172 break; 3173 default: 3174 /* only the above fields are valid */ 3175 return -EINVAL; 3176 } 3177 3178 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3179 if (!tmprule) 3180 return -ENOMEM; 3181 3182 context_init(&tmprule->au_ctxt); 3183 3184 read_lock(&policy_rwlock); 3185 3186 tmprule->au_seqno = latest_granting; 3187 3188 switch (field) { 3189 case AUDIT_SUBJ_USER: 3190 case AUDIT_OBJ_USER: 3191 rc = -EINVAL; 3192 userdatum = hashtab_search(policydb.p_users.table, rulestr); 3193 if (!userdatum) 3194 goto out; 3195 tmprule->au_ctxt.user = userdatum->value; 3196 break; 3197 case AUDIT_SUBJ_ROLE: 3198 case AUDIT_OBJ_ROLE: 3199 rc = -EINVAL; 3200 roledatum = hashtab_search(policydb.p_roles.table, rulestr); 3201 if (!roledatum) 3202 goto out; 3203 tmprule->au_ctxt.role = roledatum->value; 3204 break; 3205 case AUDIT_SUBJ_TYPE: 3206 case AUDIT_OBJ_TYPE: 3207 rc = -EINVAL; 3208 typedatum = hashtab_search(policydb.p_types.table, rulestr); 3209 if (!typedatum) 3210 goto out; 3211 tmprule->au_ctxt.type = typedatum->value; 3212 break; 3213 case AUDIT_SUBJ_SEN: 3214 case AUDIT_SUBJ_CLR: 3215 case AUDIT_OBJ_LEV_LOW: 3216 case AUDIT_OBJ_LEV_HIGH: 3217 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC); 3218 if (rc) 3219 goto out; 3220 break; 3221 } 3222 rc = 0; 3223 out: 3224 read_unlock(&policy_rwlock); 3225 3226 if (rc) { 3227 selinux_audit_rule_free(tmprule); 3228 tmprule = NULL; 3229 } 3230 3231 *rule = tmprule; 3232 3233 return rc; 3234 } 3235 3236 /* Check to see if the rule contains any selinux fields */ 3237 int selinux_audit_rule_known(struct audit_krule *rule) 3238 { 3239 int i; 3240 3241 for (i = 0; i < rule->field_count; i++) { 3242 struct audit_field *f = &rule->fields[i]; 3243 switch (f->type) { 3244 case AUDIT_SUBJ_USER: 3245 case AUDIT_SUBJ_ROLE: 3246 case AUDIT_SUBJ_TYPE: 3247 case AUDIT_SUBJ_SEN: 3248 case AUDIT_SUBJ_CLR: 3249 case AUDIT_OBJ_USER: 3250 case AUDIT_OBJ_ROLE: 3251 case AUDIT_OBJ_TYPE: 3252 case AUDIT_OBJ_LEV_LOW: 3253 case AUDIT_OBJ_LEV_HIGH: 3254 return 1; 3255 } 3256 } 3257 3258 return 0; 3259 } 3260 3261 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, 3262 struct audit_context *actx) 3263 { 3264 struct context *ctxt; 3265 struct mls_level *level; 3266 struct selinux_audit_rule *rule = vrule; 3267 int match = 0; 3268 3269 if (unlikely(!rule)) { 3270 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3271 return -ENOENT; 3272 } 3273 3274 read_lock(&policy_rwlock); 3275 3276 if (rule->au_seqno < latest_granting) { 3277 match = -ESTALE; 3278 goto out; 3279 } 3280 3281 ctxt = sidtab_search(&sidtab, sid); 3282 if (unlikely(!ctxt)) { 3283 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3284 sid); 3285 match = -ENOENT; 3286 goto out; 3287 } 3288 3289 /* a field/op pair that is not caught here will simply fall through 3290 without a match */ 3291 switch (field) { 3292 case AUDIT_SUBJ_USER: 3293 case AUDIT_OBJ_USER: 3294 switch (op) { 3295 case Audit_equal: 3296 match = (ctxt->user == rule->au_ctxt.user); 3297 break; 3298 case Audit_not_equal: 3299 match = (ctxt->user != rule->au_ctxt.user); 3300 break; 3301 } 3302 break; 3303 case AUDIT_SUBJ_ROLE: 3304 case AUDIT_OBJ_ROLE: 3305 switch (op) { 3306 case Audit_equal: 3307 match = (ctxt->role == rule->au_ctxt.role); 3308 break; 3309 case Audit_not_equal: 3310 match = (ctxt->role != rule->au_ctxt.role); 3311 break; 3312 } 3313 break; 3314 case AUDIT_SUBJ_TYPE: 3315 case AUDIT_OBJ_TYPE: 3316 switch (op) { 3317 case Audit_equal: 3318 match = (ctxt->type == rule->au_ctxt.type); 3319 break; 3320 case Audit_not_equal: 3321 match = (ctxt->type != rule->au_ctxt.type); 3322 break; 3323 } 3324 break; 3325 case AUDIT_SUBJ_SEN: 3326 case AUDIT_SUBJ_CLR: 3327 case AUDIT_OBJ_LEV_LOW: 3328 case AUDIT_OBJ_LEV_HIGH: 3329 level = ((field == AUDIT_SUBJ_SEN || 3330 field == AUDIT_OBJ_LEV_LOW) ? 3331 &ctxt->range.level[0] : &ctxt->range.level[1]); 3332 switch (op) { 3333 case Audit_equal: 3334 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3335 level); 3336 break; 3337 case Audit_not_equal: 3338 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3339 level); 3340 break; 3341 case Audit_lt: 3342 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3343 level) && 3344 !mls_level_eq(&rule->au_ctxt.range.level[0], 3345 level)); 3346 break; 3347 case Audit_le: 3348 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3349 level); 3350 break; 3351 case Audit_gt: 3352 match = (mls_level_dom(level, 3353 &rule->au_ctxt.range.level[0]) && 3354 !mls_level_eq(level, 3355 &rule->au_ctxt.range.level[0])); 3356 break; 3357 case Audit_ge: 3358 match = mls_level_dom(level, 3359 &rule->au_ctxt.range.level[0]); 3360 break; 3361 } 3362 } 3363 3364 out: 3365 read_unlock(&policy_rwlock); 3366 return match; 3367 } 3368 3369 static int (*aurule_callback)(void) = audit_update_lsm_rules; 3370 3371 static int aurule_avc_callback(u32 event) 3372 { 3373 int err = 0; 3374 3375 if (event == AVC_CALLBACK_RESET && aurule_callback) 3376 err = aurule_callback(); 3377 return err; 3378 } 3379 3380 static int __init aurule_init(void) 3381 { 3382 int err; 3383 3384 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3385 if (err) 3386 panic("avc_add_callback() failed, error %d\n", err); 3387 3388 return err; 3389 } 3390 __initcall(aurule_init); 3391 3392 #ifdef CONFIG_NETLABEL 3393 /** 3394 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3395 * @secattr: the NetLabel packet security attributes 3396 * @sid: the SELinux SID 3397 * 3398 * Description: 3399 * Attempt to cache the context in @ctx, which was derived from the packet in 3400 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3401 * already been initialized. 3402 * 3403 */ 3404 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3405 u32 sid) 3406 { 3407 u32 *sid_cache; 3408 3409 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3410 if (sid_cache == NULL) 3411 return; 3412 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3413 if (secattr->cache == NULL) { 3414 kfree(sid_cache); 3415 return; 3416 } 3417 3418 *sid_cache = sid; 3419 secattr->cache->free = kfree; 3420 secattr->cache->data = sid_cache; 3421 secattr->flags |= NETLBL_SECATTR_CACHE; 3422 } 3423 3424 /** 3425 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3426 * @secattr: the NetLabel packet security attributes 3427 * @sid: the SELinux SID 3428 * 3429 * Description: 3430 * Convert the given NetLabel security attributes in @secattr into a 3431 * SELinux SID. If the @secattr field does not contain a full SELinux 3432 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3433 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3434 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3435 * conversion for future lookups. Returns zero on success, negative values on 3436 * failure. 3437 * 3438 */ 3439 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3440 u32 *sid) 3441 { 3442 int rc; 3443 struct context *ctx; 3444 struct context ctx_new; 3445 3446 if (!ss_initialized) { 3447 *sid = SECSID_NULL; 3448 return 0; 3449 } 3450 3451 read_lock(&policy_rwlock); 3452 3453 if (secattr->flags & NETLBL_SECATTR_CACHE) 3454 *sid = *(u32 *)secattr->cache->data; 3455 else if (secattr->flags & NETLBL_SECATTR_SECID) 3456 *sid = secattr->attr.secid; 3457 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3458 rc = -EIDRM; 3459 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG); 3460 if (ctx == NULL) 3461 goto out; 3462 3463 context_init(&ctx_new); 3464 ctx_new.user = ctx->user; 3465 ctx_new.role = ctx->role; 3466 ctx_new.type = ctx->type; 3467 mls_import_netlbl_lvl(&ctx_new, secattr); 3468 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3469 rc = mls_import_netlbl_cat(&ctx_new, secattr); 3470 if (rc) 3471 goto out; 3472 } 3473 rc = -EIDRM; 3474 if (!mls_context_isvalid(&policydb, &ctx_new)) 3475 goto out_free; 3476 3477 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); 3478 if (rc) 3479 goto out_free; 3480 3481 security_netlbl_cache_add(secattr, *sid); 3482 3483 ebitmap_destroy(&ctx_new.range.level[0].cat); 3484 } else 3485 *sid = SECSID_NULL; 3486 3487 read_unlock(&policy_rwlock); 3488 return 0; 3489 out_free: 3490 ebitmap_destroy(&ctx_new.range.level[0].cat); 3491 out: 3492 read_unlock(&policy_rwlock); 3493 return rc; 3494 } 3495 3496 /** 3497 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3498 * @sid: the SELinux SID 3499 * @secattr: the NetLabel packet security attributes 3500 * 3501 * Description: 3502 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3503 * Returns zero on success, negative values on failure. 3504 * 3505 */ 3506 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3507 { 3508 int rc; 3509 struct context *ctx; 3510 3511 if (!ss_initialized) 3512 return 0; 3513 3514 read_lock(&policy_rwlock); 3515 3516 rc = -ENOENT; 3517 ctx = sidtab_search(&sidtab, sid); 3518 if (ctx == NULL) 3519 goto out; 3520 3521 rc = -ENOMEM; 3522 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1), 3523 GFP_ATOMIC); 3524 if (secattr->domain == NULL) 3525 goto out; 3526 3527 secattr->attr.secid = sid; 3528 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3529 mls_export_netlbl_lvl(ctx, secattr); 3530 rc = mls_export_netlbl_cat(ctx, secattr); 3531 out: 3532 read_unlock(&policy_rwlock); 3533 return rc; 3534 } 3535 #endif /* CONFIG_NETLABEL */ 3536 3537 /** 3538 * security_read_policy - read the policy. 3539 * @data: binary policy data 3540 * @len: length of data in bytes 3541 * 3542 */ 3543 int security_read_policy(void **data, size_t *len) 3544 { 3545 int rc; 3546 struct policy_file fp; 3547 3548 if (!ss_initialized) 3549 return -EINVAL; 3550 3551 *len = security_policydb_len(); 3552 3553 *data = vmalloc_user(*len); 3554 if (!*data) 3555 return -ENOMEM; 3556 3557 fp.data = *data; 3558 fp.len = *len; 3559 3560 read_lock(&policy_rwlock); 3561 rc = policydb_write(&policydb, &fp); 3562 read_unlock(&policy_rwlock); 3563 3564 if (rc) 3565 return rc; 3566 3567 *len = (unsigned long)fp.data - (unsigned long)*data; 3568 return 0; 3569 3570 } 3571