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 if (!ss_initialized) 871 return 0; 872 873 read_lock(&policy_rwlock); 874 875 rc = -EINVAL; 876 old_context = sidtab_search(&sidtab, old_sid); 877 if (!old_context) { 878 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 879 __func__, old_sid); 880 goto out; 881 } 882 883 rc = -EINVAL; 884 new_context = sidtab_search(&sidtab, new_sid); 885 if (!new_context) { 886 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 887 __func__, new_sid); 888 goto out; 889 } 890 891 rc = 0; 892 /* type/domain unchanged */ 893 if (old_context->type == new_context->type) 894 goto out; 895 896 index = new_context->type; 897 while (true) { 898 type = flex_array_get_ptr(policydb.type_val_to_struct_array, 899 index - 1); 900 BUG_ON(!type); 901 902 /* not bounded anymore */ 903 rc = -EPERM; 904 if (!type->bounds) 905 break; 906 907 /* @newsid is bounded by @oldsid */ 908 rc = 0; 909 if (type->bounds == old_context->type) 910 break; 911 912 index = type->bounds; 913 } 914 915 if (rc) { 916 char *old_name = NULL; 917 char *new_name = NULL; 918 u32 length; 919 920 if (!context_struct_to_string(old_context, 921 &old_name, &length) && 922 !context_struct_to_string(new_context, 923 &new_name, &length)) { 924 audit_log(current->audit_context, 925 GFP_ATOMIC, AUDIT_SELINUX_ERR, 926 "op=security_bounded_transition " 927 "seresult=denied " 928 "oldcontext=%s newcontext=%s", 929 old_name, new_name); 930 } 931 kfree(new_name); 932 kfree(old_name); 933 } 934 out: 935 read_unlock(&policy_rwlock); 936 937 return rc; 938 } 939 940 static void avd_init(struct av_decision *avd) 941 { 942 avd->allowed = 0; 943 avd->auditallow = 0; 944 avd->auditdeny = 0xffffffff; 945 avd->seqno = latest_granting; 946 avd->flags = 0; 947 } 948 949 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 950 struct avtab_node *node) 951 { 952 unsigned int i; 953 954 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 955 if (xpermd->driver != node->datum.u.xperms->driver) 956 return; 957 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 958 if (!security_xperm_test(node->datum.u.xperms->perms.p, 959 xpermd->driver)) 960 return; 961 } else { 962 BUG(); 963 } 964 965 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 966 xpermd->used |= XPERMS_ALLOWED; 967 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 968 memset(xpermd->allowed->p, 0xff, 969 sizeof(xpermd->allowed->p)); 970 } 971 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 972 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 973 xpermd->allowed->p[i] |= 974 node->datum.u.xperms->perms.p[i]; 975 } 976 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 977 xpermd->used |= XPERMS_AUDITALLOW; 978 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 979 memset(xpermd->auditallow->p, 0xff, 980 sizeof(xpermd->auditallow->p)); 981 } 982 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 983 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 984 xpermd->auditallow->p[i] |= 985 node->datum.u.xperms->perms.p[i]; 986 } 987 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 988 xpermd->used |= XPERMS_DONTAUDIT; 989 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 990 memset(xpermd->dontaudit->p, 0xff, 991 sizeof(xpermd->dontaudit->p)); 992 } 993 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 994 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 995 xpermd->dontaudit->p[i] |= 996 node->datum.u.xperms->perms.p[i]; 997 } 998 } else { 999 BUG(); 1000 } 1001 } 1002 1003 void security_compute_xperms_decision(u32 ssid, 1004 u32 tsid, 1005 u16 orig_tclass, 1006 u8 driver, 1007 struct extended_perms_decision *xpermd) 1008 { 1009 u16 tclass; 1010 struct context *scontext, *tcontext; 1011 struct avtab_key avkey; 1012 struct avtab_node *node; 1013 struct ebitmap *sattr, *tattr; 1014 struct ebitmap_node *snode, *tnode; 1015 unsigned int i, j; 1016 1017 xpermd->driver = driver; 1018 xpermd->used = 0; 1019 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1020 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1021 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1022 1023 read_lock(&policy_rwlock); 1024 if (!ss_initialized) 1025 goto allow; 1026 1027 scontext = sidtab_search(&sidtab, ssid); 1028 if (!scontext) { 1029 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1030 __func__, ssid); 1031 goto out; 1032 } 1033 1034 tcontext = sidtab_search(&sidtab, tsid); 1035 if (!tcontext) { 1036 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1037 __func__, tsid); 1038 goto out; 1039 } 1040 1041 tclass = unmap_class(orig_tclass); 1042 if (unlikely(orig_tclass && !tclass)) { 1043 if (policydb.allow_unknown) 1044 goto allow; 1045 goto out; 1046 } 1047 1048 1049 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 1050 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1051 goto out; 1052 } 1053 1054 avkey.target_class = tclass; 1055 avkey.specified = AVTAB_XPERMS; 1056 sattr = flex_array_get(policydb.type_attr_map_array, 1057 scontext->type - 1); 1058 BUG_ON(!sattr); 1059 tattr = flex_array_get(policydb.type_attr_map_array, 1060 tcontext->type - 1); 1061 BUG_ON(!tattr); 1062 ebitmap_for_each_positive_bit(sattr, snode, i) { 1063 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1064 avkey.source_type = i + 1; 1065 avkey.target_type = j + 1; 1066 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 1067 node; 1068 node = avtab_search_node_next(node, avkey.specified)) 1069 services_compute_xperms_decision(xpermd, node); 1070 1071 cond_compute_xperms(&policydb.te_cond_avtab, 1072 &avkey, xpermd); 1073 } 1074 } 1075 out: 1076 read_unlock(&policy_rwlock); 1077 return; 1078 allow: 1079 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1080 goto out; 1081 } 1082 1083 /** 1084 * security_compute_av - Compute access vector decisions. 1085 * @ssid: source security identifier 1086 * @tsid: target security identifier 1087 * @tclass: target security class 1088 * @avd: access vector decisions 1089 * @xperms: extended permissions 1090 * 1091 * Compute a set of access vector decisions based on the 1092 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1093 */ 1094 void security_compute_av(u32 ssid, 1095 u32 tsid, 1096 u16 orig_tclass, 1097 struct av_decision *avd, 1098 struct extended_perms *xperms) 1099 { 1100 u16 tclass; 1101 struct context *scontext = NULL, *tcontext = NULL; 1102 1103 read_lock(&policy_rwlock); 1104 avd_init(avd); 1105 xperms->len = 0; 1106 if (!ss_initialized) 1107 goto allow; 1108 1109 scontext = sidtab_search(&sidtab, ssid); 1110 if (!scontext) { 1111 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1112 __func__, ssid); 1113 goto out; 1114 } 1115 1116 /* permissive domain? */ 1117 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1118 avd->flags |= AVD_FLAGS_PERMISSIVE; 1119 1120 tcontext = sidtab_search(&sidtab, tsid); 1121 if (!tcontext) { 1122 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1123 __func__, tsid); 1124 goto out; 1125 } 1126 1127 tclass = unmap_class(orig_tclass); 1128 if (unlikely(orig_tclass && !tclass)) { 1129 if (policydb.allow_unknown) 1130 goto allow; 1131 goto out; 1132 } 1133 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms); 1134 map_decision(orig_tclass, avd, policydb.allow_unknown); 1135 out: 1136 read_unlock(&policy_rwlock); 1137 return; 1138 allow: 1139 avd->allowed = 0xffffffff; 1140 goto out; 1141 } 1142 1143 void security_compute_av_user(u32 ssid, 1144 u32 tsid, 1145 u16 tclass, 1146 struct av_decision *avd) 1147 { 1148 struct context *scontext = NULL, *tcontext = NULL; 1149 1150 read_lock(&policy_rwlock); 1151 avd_init(avd); 1152 if (!ss_initialized) 1153 goto allow; 1154 1155 scontext = sidtab_search(&sidtab, ssid); 1156 if (!scontext) { 1157 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1158 __func__, ssid); 1159 goto out; 1160 } 1161 1162 /* permissive domain? */ 1163 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1164 avd->flags |= AVD_FLAGS_PERMISSIVE; 1165 1166 tcontext = sidtab_search(&sidtab, tsid); 1167 if (!tcontext) { 1168 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1169 __func__, tsid); 1170 goto out; 1171 } 1172 1173 if (unlikely(!tclass)) { 1174 if (policydb.allow_unknown) 1175 goto allow; 1176 goto out; 1177 } 1178 1179 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL); 1180 out: 1181 read_unlock(&policy_rwlock); 1182 return; 1183 allow: 1184 avd->allowed = 0xffffffff; 1185 goto out; 1186 } 1187 1188 /* 1189 * Write the security context string representation of 1190 * the context structure `context' into a dynamically 1191 * allocated string of the correct size. Set `*scontext' 1192 * to point to this string and set `*scontext_len' to 1193 * the length of the string. 1194 */ 1195 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) 1196 { 1197 char *scontextp; 1198 1199 if (scontext) 1200 *scontext = NULL; 1201 *scontext_len = 0; 1202 1203 if (context->len) { 1204 *scontext_len = context->len; 1205 if (scontext) { 1206 *scontext = kstrdup(context->str, GFP_ATOMIC); 1207 if (!(*scontext)) 1208 return -ENOMEM; 1209 } 1210 return 0; 1211 } 1212 1213 /* Compute the size of the context. */ 1214 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1; 1215 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1; 1216 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1; 1217 *scontext_len += mls_compute_context_len(context); 1218 1219 if (!scontext) 1220 return 0; 1221 1222 /* Allocate space for the context; caller must free this space. */ 1223 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1224 if (!scontextp) 1225 return -ENOMEM; 1226 *scontext = scontextp; 1227 1228 /* 1229 * Copy the user name, role name and type name into the context. 1230 */ 1231 scontextp += sprintf(scontextp, "%s:%s:%s", 1232 sym_name(&policydb, SYM_USERS, context->user - 1), 1233 sym_name(&policydb, SYM_ROLES, context->role - 1), 1234 sym_name(&policydb, SYM_TYPES, context->type - 1)); 1235 1236 mls_sid_to_context(context, &scontextp); 1237 1238 *scontextp = 0; 1239 1240 return 0; 1241 } 1242 1243 #include "initial_sid_to_string.h" 1244 1245 const char *security_get_initial_sid_context(u32 sid) 1246 { 1247 if (unlikely(sid > SECINITSID_NUM)) 1248 return NULL; 1249 return initial_sid_to_string[sid]; 1250 } 1251 1252 static int security_sid_to_context_core(u32 sid, char **scontext, 1253 u32 *scontext_len, int force) 1254 { 1255 struct context *context; 1256 int rc = 0; 1257 1258 if (scontext) 1259 *scontext = NULL; 1260 *scontext_len = 0; 1261 1262 if (!ss_initialized) { 1263 if (sid <= SECINITSID_NUM) { 1264 char *scontextp; 1265 1266 *scontext_len = strlen(initial_sid_to_string[sid]) + 1; 1267 if (!scontext) 1268 goto out; 1269 scontextp = kmemdup(initial_sid_to_string[sid], 1270 *scontext_len, GFP_ATOMIC); 1271 if (!scontextp) { 1272 rc = -ENOMEM; 1273 goto out; 1274 } 1275 *scontext = scontextp; 1276 goto out; 1277 } 1278 printk(KERN_ERR "SELinux: %s: called before initial " 1279 "load_policy on unknown SID %d\n", __func__, sid); 1280 rc = -EINVAL; 1281 goto out; 1282 } 1283 read_lock(&policy_rwlock); 1284 if (force) 1285 context = sidtab_search_force(&sidtab, sid); 1286 else 1287 context = sidtab_search(&sidtab, sid); 1288 if (!context) { 1289 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1290 __func__, sid); 1291 rc = -EINVAL; 1292 goto out_unlock; 1293 } 1294 rc = context_struct_to_string(context, scontext, scontext_len); 1295 out_unlock: 1296 read_unlock(&policy_rwlock); 1297 out: 1298 return rc; 1299 1300 } 1301 1302 /** 1303 * security_sid_to_context - Obtain a context for a given SID. 1304 * @sid: security identifier, SID 1305 * @scontext: security context 1306 * @scontext_len: length in bytes 1307 * 1308 * Write the string representation of the context associated with @sid 1309 * into a dynamically allocated string of the correct size. Set @scontext 1310 * to point to this string and set @scontext_len to the length of the string. 1311 */ 1312 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1313 { 1314 return security_sid_to_context_core(sid, scontext, scontext_len, 0); 1315 } 1316 1317 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len) 1318 { 1319 return security_sid_to_context_core(sid, scontext, scontext_len, 1); 1320 } 1321 1322 /* 1323 * Caveat: Mutates scontext. 1324 */ 1325 static int string_to_context_struct(struct policydb *pol, 1326 struct sidtab *sidtabp, 1327 char *scontext, 1328 u32 scontext_len, 1329 struct context *ctx, 1330 u32 def_sid) 1331 { 1332 struct role_datum *role; 1333 struct type_datum *typdatum; 1334 struct user_datum *usrdatum; 1335 char *scontextp, *p, oldc; 1336 int rc = 0; 1337 1338 context_init(ctx); 1339 1340 /* Parse the security context. */ 1341 1342 rc = -EINVAL; 1343 scontextp = (char *) scontext; 1344 1345 /* Extract the user. */ 1346 p = scontextp; 1347 while (*p && *p != ':') 1348 p++; 1349 1350 if (*p == 0) 1351 goto out; 1352 1353 *p++ = 0; 1354 1355 usrdatum = hashtab_search(pol->p_users.table, scontextp); 1356 if (!usrdatum) 1357 goto out; 1358 1359 ctx->user = usrdatum->value; 1360 1361 /* Extract role. */ 1362 scontextp = p; 1363 while (*p && *p != ':') 1364 p++; 1365 1366 if (*p == 0) 1367 goto out; 1368 1369 *p++ = 0; 1370 1371 role = hashtab_search(pol->p_roles.table, scontextp); 1372 if (!role) 1373 goto out; 1374 ctx->role = role->value; 1375 1376 /* Extract type. */ 1377 scontextp = p; 1378 while (*p && *p != ':') 1379 p++; 1380 oldc = *p; 1381 *p++ = 0; 1382 1383 typdatum = hashtab_search(pol->p_types.table, scontextp); 1384 if (!typdatum || typdatum->attribute) 1385 goto out; 1386 1387 ctx->type = typdatum->value; 1388 1389 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid); 1390 if (rc) 1391 goto out; 1392 1393 rc = -EINVAL; 1394 if ((p - scontext) < scontext_len) 1395 goto out; 1396 1397 /* Check the validity of the new context. */ 1398 if (!policydb_context_isvalid(pol, ctx)) 1399 goto out; 1400 rc = 0; 1401 out: 1402 if (rc) 1403 context_destroy(ctx); 1404 return rc; 1405 } 1406 1407 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1408 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1409 int force) 1410 { 1411 char *scontext2, *str = NULL; 1412 struct context context; 1413 int rc = 0; 1414 1415 /* An empty security context is never valid. */ 1416 if (!scontext_len) 1417 return -EINVAL; 1418 1419 /* Copy the string to allow changes and ensure a NUL terminator */ 1420 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1421 if (!scontext2) 1422 return -ENOMEM; 1423 1424 if (!ss_initialized) { 1425 int i; 1426 1427 for (i = 1; i < SECINITSID_NUM; i++) { 1428 if (!strcmp(initial_sid_to_string[i], scontext2)) { 1429 *sid = i; 1430 goto out; 1431 } 1432 } 1433 *sid = SECINITSID_KERNEL; 1434 goto out; 1435 } 1436 *sid = SECSID_NULL; 1437 1438 if (force) { 1439 /* Save another copy for storing in uninterpreted form */ 1440 rc = -ENOMEM; 1441 str = kstrdup(scontext2, gfp_flags); 1442 if (!str) 1443 goto out; 1444 } 1445 1446 read_lock(&policy_rwlock); 1447 rc = string_to_context_struct(&policydb, &sidtab, scontext2, 1448 scontext_len, &context, def_sid); 1449 if (rc == -EINVAL && force) { 1450 context.str = str; 1451 context.len = scontext_len; 1452 str = NULL; 1453 } else if (rc) 1454 goto out_unlock; 1455 rc = sidtab_context_to_sid(&sidtab, &context, sid); 1456 context_destroy(&context); 1457 out_unlock: 1458 read_unlock(&policy_rwlock); 1459 out: 1460 kfree(scontext2); 1461 kfree(str); 1462 return rc; 1463 } 1464 1465 /** 1466 * security_context_to_sid - Obtain a SID for a given security context. 1467 * @scontext: security context 1468 * @scontext_len: length in bytes 1469 * @sid: security identifier, SID 1470 * @gfp: context for the allocation 1471 * 1472 * Obtains a SID associated with the security context that 1473 * has the string representation specified by @scontext. 1474 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1475 * memory is available, or 0 on success. 1476 */ 1477 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1478 gfp_t gfp) 1479 { 1480 return security_context_to_sid_core(scontext, scontext_len, 1481 sid, SECSID_NULL, gfp, 0); 1482 } 1483 1484 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1485 { 1486 return security_context_to_sid(scontext, strlen(scontext), sid, gfp); 1487 } 1488 1489 /** 1490 * security_context_to_sid_default - Obtain a SID for a given security context, 1491 * falling back to specified default if needed. 1492 * 1493 * @scontext: security context 1494 * @scontext_len: length in bytes 1495 * @sid: security identifier, SID 1496 * @def_sid: default SID to assign on error 1497 * 1498 * Obtains a SID associated with the security context that 1499 * has the string representation specified by @scontext. 1500 * The default SID is passed to the MLS layer to be used to allow 1501 * kernel labeling of the MLS field if the MLS field is not present 1502 * (for upgrading to MLS without full relabel). 1503 * Implicitly forces adding of the context even if it cannot be mapped yet. 1504 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1505 * memory is available, or 0 on success. 1506 */ 1507 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1508 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1509 { 1510 return security_context_to_sid_core(scontext, scontext_len, 1511 sid, def_sid, gfp_flags, 1); 1512 } 1513 1514 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1515 u32 *sid) 1516 { 1517 return security_context_to_sid_core(scontext, scontext_len, 1518 sid, SECSID_NULL, GFP_KERNEL, 1); 1519 } 1520 1521 static int compute_sid_handle_invalid_context( 1522 struct context *scontext, 1523 struct context *tcontext, 1524 u16 tclass, 1525 struct context *newcontext) 1526 { 1527 char *s = NULL, *t = NULL, *n = NULL; 1528 u32 slen, tlen, nlen; 1529 1530 if (context_struct_to_string(scontext, &s, &slen)) 1531 goto out; 1532 if (context_struct_to_string(tcontext, &t, &tlen)) 1533 goto out; 1534 if (context_struct_to_string(newcontext, &n, &nlen)) 1535 goto out; 1536 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 1537 "op=security_compute_sid invalid_context=%s" 1538 " scontext=%s" 1539 " tcontext=%s" 1540 " tclass=%s", 1541 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 1542 out: 1543 kfree(s); 1544 kfree(t); 1545 kfree(n); 1546 if (!selinux_enforcing) 1547 return 0; 1548 return -EACCES; 1549 } 1550 1551 static void filename_compute_type(struct policydb *p, struct context *newcontext, 1552 u32 stype, u32 ttype, u16 tclass, 1553 const char *objname) 1554 { 1555 struct filename_trans ft; 1556 struct filename_trans_datum *otype; 1557 1558 /* 1559 * Most filename trans rules are going to live in specific directories 1560 * like /dev or /var/run. This bitmap will quickly skip rule searches 1561 * if the ttype does not contain any rules. 1562 */ 1563 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype)) 1564 return; 1565 1566 ft.stype = stype; 1567 ft.ttype = ttype; 1568 ft.tclass = tclass; 1569 ft.name = objname; 1570 1571 otype = hashtab_search(p->filename_trans, &ft); 1572 if (otype) 1573 newcontext->type = otype->otype; 1574 } 1575 1576 static int security_compute_sid(u32 ssid, 1577 u32 tsid, 1578 u16 orig_tclass, 1579 u32 specified, 1580 const char *objname, 1581 u32 *out_sid, 1582 bool kern) 1583 { 1584 struct class_datum *cladatum = NULL; 1585 struct context *scontext = NULL, *tcontext = NULL, newcontext; 1586 struct role_trans *roletr = NULL; 1587 struct avtab_key avkey; 1588 struct avtab_datum *avdatum; 1589 struct avtab_node *node; 1590 u16 tclass; 1591 int rc = 0; 1592 bool sock; 1593 1594 if (!ss_initialized) { 1595 switch (orig_tclass) { 1596 case SECCLASS_PROCESS: /* kernel value */ 1597 *out_sid = ssid; 1598 break; 1599 default: 1600 *out_sid = tsid; 1601 break; 1602 } 1603 goto out; 1604 } 1605 1606 context_init(&newcontext); 1607 1608 read_lock(&policy_rwlock); 1609 1610 if (kern) { 1611 tclass = unmap_class(orig_tclass); 1612 sock = security_is_socket_class(orig_tclass); 1613 } else { 1614 tclass = orig_tclass; 1615 sock = security_is_socket_class(map_class(tclass)); 1616 } 1617 1618 scontext = sidtab_search(&sidtab, ssid); 1619 if (!scontext) { 1620 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1621 __func__, ssid); 1622 rc = -EINVAL; 1623 goto out_unlock; 1624 } 1625 tcontext = sidtab_search(&sidtab, tsid); 1626 if (!tcontext) { 1627 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1628 __func__, tsid); 1629 rc = -EINVAL; 1630 goto out_unlock; 1631 } 1632 1633 if (tclass && tclass <= policydb.p_classes.nprim) 1634 cladatum = policydb.class_val_to_struct[tclass - 1]; 1635 1636 /* Set the user identity. */ 1637 switch (specified) { 1638 case AVTAB_TRANSITION: 1639 case AVTAB_CHANGE: 1640 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1641 newcontext.user = tcontext->user; 1642 } else { 1643 /* notice this gets both DEFAULT_SOURCE and unset */ 1644 /* Use the process user identity. */ 1645 newcontext.user = scontext->user; 1646 } 1647 break; 1648 case AVTAB_MEMBER: 1649 /* Use the related object owner. */ 1650 newcontext.user = tcontext->user; 1651 break; 1652 } 1653 1654 /* Set the role to default values. */ 1655 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1656 newcontext.role = scontext->role; 1657 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1658 newcontext.role = tcontext->role; 1659 } else { 1660 if ((tclass == policydb.process_class) || (sock == true)) 1661 newcontext.role = scontext->role; 1662 else 1663 newcontext.role = OBJECT_R_VAL; 1664 } 1665 1666 /* Set the type to default values. */ 1667 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1668 newcontext.type = scontext->type; 1669 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1670 newcontext.type = tcontext->type; 1671 } else { 1672 if ((tclass == policydb.process_class) || (sock == true)) { 1673 /* Use the type of process. */ 1674 newcontext.type = scontext->type; 1675 } else { 1676 /* Use the type of the related object. */ 1677 newcontext.type = tcontext->type; 1678 } 1679 } 1680 1681 /* Look for a type transition/member/change rule. */ 1682 avkey.source_type = scontext->type; 1683 avkey.target_type = tcontext->type; 1684 avkey.target_class = tclass; 1685 avkey.specified = specified; 1686 avdatum = avtab_search(&policydb.te_avtab, &avkey); 1687 1688 /* If no permanent rule, also check for enabled conditional rules */ 1689 if (!avdatum) { 1690 node = avtab_search_node(&policydb.te_cond_avtab, &avkey); 1691 for (; node; node = avtab_search_node_next(node, specified)) { 1692 if (node->key.specified & AVTAB_ENABLED) { 1693 avdatum = &node->datum; 1694 break; 1695 } 1696 } 1697 } 1698 1699 if (avdatum) { 1700 /* Use the type from the type transition/member/change rule. */ 1701 newcontext.type = avdatum->u.data; 1702 } 1703 1704 /* if we have a objname this is a file trans check so check those rules */ 1705 if (objname) 1706 filename_compute_type(&policydb, &newcontext, scontext->type, 1707 tcontext->type, tclass, objname); 1708 1709 /* Check for class-specific changes. */ 1710 if (specified & AVTAB_TRANSITION) { 1711 /* Look for a role transition rule. */ 1712 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) { 1713 if ((roletr->role == scontext->role) && 1714 (roletr->type == tcontext->type) && 1715 (roletr->tclass == tclass)) { 1716 /* Use the role transition rule. */ 1717 newcontext.role = roletr->new_role; 1718 break; 1719 } 1720 } 1721 } 1722 1723 /* Set the MLS attributes. 1724 This is done last because it may allocate memory. */ 1725 rc = mls_compute_sid(scontext, tcontext, tclass, specified, 1726 &newcontext, sock); 1727 if (rc) 1728 goto out_unlock; 1729 1730 /* Check the validity of the context. */ 1731 if (!policydb_context_isvalid(&policydb, &newcontext)) { 1732 rc = compute_sid_handle_invalid_context(scontext, 1733 tcontext, 1734 tclass, 1735 &newcontext); 1736 if (rc) 1737 goto out_unlock; 1738 } 1739 /* Obtain the sid for the context. */ 1740 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); 1741 out_unlock: 1742 read_unlock(&policy_rwlock); 1743 context_destroy(&newcontext); 1744 out: 1745 return rc; 1746 } 1747 1748 /** 1749 * security_transition_sid - Compute the SID for a new subject/object. 1750 * @ssid: source security identifier 1751 * @tsid: target security identifier 1752 * @tclass: target security class 1753 * @out_sid: security identifier for new subject/object 1754 * 1755 * Compute a SID to use for labeling a new subject or object in the 1756 * class @tclass based on a SID pair (@ssid, @tsid). 1757 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1758 * if insufficient memory is available, or %0 if the new SID was 1759 * computed successfully. 1760 */ 1761 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1762 const struct qstr *qstr, u32 *out_sid) 1763 { 1764 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1765 qstr ? qstr->name : NULL, out_sid, true); 1766 } 1767 1768 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1769 const char *objname, u32 *out_sid) 1770 { 1771 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1772 objname, out_sid, false); 1773 } 1774 1775 /** 1776 * security_member_sid - Compute the SID for member selection. 1777 * @ssid: source security identifier 1778 * @tsid: target security identifier 1779 * @tclass: target security class 1780 * @out_sid: security identifier for selected member 1781 * 1782 * Compute a SID to use when selecting a member of a polyinstantiated 1783 * object of class @tclass based on a SID pair (@ssid, @tsid). 1784 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1785 * if insufficient memory is available, or %0 if the SID was 1786 * computed successfully. 1787 */ 1788 int security_member_sid(u32 ssid, 1789 u32 tsid, 1790 u16 tclass, 1791 u32 *out_sid) 1792 { 1793 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL, 1794 out_sid, false); 1795 } 1796 1797 /** 1798 * security_change_sid - Compute the SID for object relabeling. 1799 * @ssid: source security identifier 1800 * @tsid: target security identifier 1801 * @tclass: target security class 1802 * @out_sid: security identifier for selected member 1803 * 1804 * Compute a SID to use for relabeling an object of class @tclass 1805 * based on a SID pair (@ssid, @tsid). 1806 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1807 * if insufficient memory is available, or %0 if the SID was 1808 * computed successfully. 1809 */ 1810 int security_change_sid(u32 ssid, 1811 u32 tsid, 1812 u16 tclass, 1813 u32 *out_sid) 1814 { 1815 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1816 out_sid, false); 1817 } 1818 1819 /* Clone the SID into the new SID table. */ 1820 static int clone_sid(u32 sid, 1821 struct context *context, 1822 void *arg) 1823 { 1824 struct sidtab *s = arg; 1825 1826 if (sid > SECINITSID_NUM) 1827 return sidtab_insert(s, sid, context); 1828 else 1829 return 0; 1830 } 1831 1832 static inline int convert_context_handle_invalid_context(struct context *context) 1833 { 1834 char *s; 1835 u32 len; 1836 1837 if (selinux_enforcing) 1838 return -EINVAL; 1839 1840 if (!context_struct_to_string(context, &s, &len)) { 1841 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s); 1842 kfree(s); 1843 } 1844 return 0; 1845 } 1846 1847 struct convert_context_args { 1848 struct policydb *oldp; 1849 struct policydb *newp; 1850 }; 1851 1852 /* 1853 * Convert the values in the security context 1854 * structure `c' from the values specified 1855 * in the policy `p->oldp' to the values specified 1856 * in the policy `p->newp'. Verify that the 1857 * context is valid under the new policy. 1858 */ 1859 static int convert_context(u32 key, 1860 struct context *c, 1861 void *p) 1862 { 1863 struct convert_context_args *args; 1864 struct context oldc; 1865 struct ocontext *oc; 1866 struct mls_range *range; 1867 struct role_datum *role; 1868 struct type_datum *typdatum; 1869 struct user_datum *usrdatum; 1870 char *s; 1871 u32 len; 1872 int rc = 0; 1873 1874 if (key <= SECINITSID_NUM) 1875 goto out; 1876 1877 args = p; 1878 1879 if (c->str) { 1880 struct context ctx; 1881 1882 rc = -ENOMEM; 1883 s = kstrdup(c->str, GFP_KERNEL); 1884 if (!s) 1885 goto out; 1886 1887 rc = string_to_context_struct(args->newp, NULL, s, 1888 c->len, &ctx, SECSID_NULL); 1889 kfree(s); 1890 if (!rc) { 1891 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n", 1892 c->str); 1893 /* Replace string with mapped representation. */ 1894 kfree(c->str); 1895 memcpy(c, &ctx, sizeof(*c)); 1896 goto out; 1897 } else if (rc == -EINVAL) { 1898 /* Retain string representation for later mapping. */ 1899 rc = 0; 1900 goto out; 1901 } else { 1902 /* Other error condition, e.g. ENOMEM. */ 1903 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n", 1904 c->str, -rc); 1905 goto out; 1906 } 1907 } 1908 1909 rc = context_cpy(&oldc, c); 1910 if (rc) 1911 goto out; 1912 1913 /* Convert the user. */ 1914 rc = -EINVAL; 1915 usrdatum = hashtab_search(args->newp->p_users.table, 1916 sym_name(args->oldp, SYM_USERS, c->user - 1)); 1917 if (!usrdatum) 1918 goto bad; 1919 c->user = usrdatum->value; 1920 1921 /* Convert the role. */ 1922 rc = -EINVAL; 1923 role = hashtab_search(args->newp->p_roles.table, 1924 sym_name(args->oldp, SYM_ROLES, c->role - 1)); 1925 if (!role) 1926 goto bad; 1927 c->role = role->value; 1928 1929 /* Convert the type. */ 1930 rc = -EINVAL; 1931 typdatum = hashtab_search(args->newp->p_types.table, 1932 sym_name(args->oldp, SYM_TYPES, c->type - 1)); 1933 if (!typdatum) 1934 goto bad; 1935 c->type = typdatum->value; 1936 1937 /* Convert the MLS fields if dealing with MLS policies */ 1938 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 1939 rc = mls_convert_context(args->oldp, args->newp, c); 1940 if (rc) 1941 goto bad; 1942 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) { 1943 /* 1944 * Switching between MLS and non-MLS policy: 1945 * free any storage used by the MLS fields in the 1946 * context for all existing entries in the sidtab. 1947 */ 1948 mls_context_destroy(c); 1949 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 1950 /* 1951 * Switching between non-MLS and MLS policy: 1952 * ensure that the MLS fields of the context for all 1953 * existing entries in the sidtab are filled in with a 1954 * suitable default value, likely taken from one of the 1955 * initial SIDs. 1956 */ 1957 oc = args->newp->ocontexts[OCON_ISID]; 1958 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 1959 oc = oc->next; 1960 rc = -EINVAL; 1961 if (!oc) { 1962 printk(KERN_ERR "SELinux: unable to look up" 1963 " the initial SIDs list\n"); 1964 goto bad; 1965 } 1966 range = &oc->context[0].range; 1967 rc = mls_range_set(c, range); 1968 if (rc) 1969 goto bad; 1970 } 1971 1972 /* Check the validity of the new context. */ 1973 if (!policydb_context_isvalid(args->newp, c)) { 1974 rc = convert_context_handle_invalid_context(&oldc); 1975 if (rc) 1976 goto bad; 1977 } 1978 1979 context_destroy(&oldc); 1980 1981 rc = 0; 1982 out: 1983 return rc; 1984 bad: 1985 /* Map old representation to string and save it. */ 1986 rc = context_struct_to_string(&oldc, &s, &len); 1987 if (rc) 1988 return rc; 1989 context_destroy(&oldc); 1990 context_destroy(c); 1991 c->str = s; 1992 c->len = len; 1993 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n", 1994 c->str); 1995 rc = 0; 1996 goto out; 1997 } 1998 1999 static void security_load_policycaps(void) 2000 { 2001 unsigned int i; 2002 struct ebitmap_node *node; 2003 2004 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps, 2005 POLICYDB_CAPABILITY_NETPEER); 2006 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps, 2007 POLICYDB_CAPABILITY_OPENPERM); 2008 selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps, 2009 POLICYDB_CAPABILITY_EXTSOCKCLASS); 2010 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps, 2011 POLICYDB_CAPABILITY_ALWAYSNETWORK); 2012 selinux_policycap_cgroupseclabel = 2013 ebitmap_get_bit(&policydb.policycaps, 2014 POLICYDB_CAPABILITY_CGROUPSECLABEL); 2015 selinux_policycap_nnp_nosuid_transition = 2016 ebitmap_get_bit(&policydb.policycaps, 2017 POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION); 2018 2019 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2020 pr_info("SELinux: policy capability %s=%d\n", 2021 selinux_policycap_names[i], 2022 ebitmap_get_bit(&policydb.policycaps, i)); 2023 2024 ebitmap_for_each_positive_bit(&policydb.policycaps, node, i) { 2025 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2026 pr_info("SELinux: unknown policy capability %u\n", 2027 i); 2028 } 2029 } 2030 2031 static int security_preserve_bools(struct policydb *p); 2032 2033 /** 2034 * security_load_policy - Load a security policy configuration. 2035 * @data: binary policy data 2036 * @len: length of data in bytes 2037 * 2038 * Load a new set of security policy configuration data, 2039 * validate it and convert the SID table as necessary. 2040 * This function will flush the access vector cache after 2041 * loading the new policy. 2042 */ 2043 int security_load_policy(void *data, size_t len) 2044 { 2045 struct policydb *oldpolicydb, *newpolicydb; 2046 struct sidtab oldsidtab, newsidtab; 2047 struct selinux_mapping *oldmap, *map = NULL; 2048 struct convert_context_args args; 2049 u32 seqno; 2050 u16 map_size; 2051 int rc = 0; 2052 struct policy_file file = { data, len }, *fp = &file; 2053 2054 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL); 2055 if (!oldpolicydb) { 2056 rc = -ENOMEM; 2057 goto out; 2058 } 2059 newpolicydb = oldpolicydb + 1; 2060 2061 if (!ss_initialized) { 2062 avtab_cache_init(); 2063 ebitmap_cache_init(); 2064 hashtab_cache_init(); 2065 rc = policydb_read(&policydb, fp); 2066 if (rc) { 2067 avtab_cache_destroy(); 2068 ebitmap_cache_destroy(); 2069 hashtab_cache_destroy(); 2070 goto out; 2071 } 2072 2073 policydb.len = len; 2074 rc = selinux_set_mapping(&policydb, secclass_map, 2075 ¤t_mapping, 2076 ¤t_mapping_size); 2077 if (rc) { 2078 policydb_destroy(&policydb); 2079 avtab_cache_destroy(); 2080 ebitmap_cache_destroy(); 2081 hashtab_cache_destroy(); 2082 goto out; 2083 } 2084 2085 rc = policydb_load_isids(&policydb, &sidtab); 2086 if (rc) { 2087 policydb_destroy(&policydb); 2088 avtab_cache_destroy(); 2089 ebitmap_cache_destroy(); 2090 hashtab_cache_destroy(); 2091 goto out; 2092 } 2093 2094 security_load_policycaps(); 2095 ss_initialized = 1; 2096 seqno = ++latest_granting; 2097 selinux_complete_init(); 2098 avc_ss_reset(seqno); 2099 selnl_notify_policyload(seqno); 2100 selinux_status_update_policyload(seqno); 2101 selinux_netlbl_cache_invalidate(); 2102 selinux_xfrm_notify_policyload(); 2103 goto out; 2104 } 2105 2106 #if 0 2107 sidtab_hash_eval(&sidtab, "sids"); 2108 #endif 2109 2110 rc = policydb_read(newpolicydb, fp); 2111 if (rc) 2112 goto out; 2113 2114 newpolicydb->len = len; 2115 /* If switching between different policy types, log MLS status */ 2116 if (policydb.mls_enabled && !newpolicydb->mls_enabled) 2117 printk(KERN_INFO "SELinux: Disabling MLS support...\n"); 2118 else if (!policydb.mls_enabled && newpolicydb->mls_enabled) 2119 printk(KERN_INFO "SELinux: Enabling MLS support...\n"); 2120 2121 rc = policydb_load_isids(newpolicydb, &newsidtab); 2122 if (rc) { 2123 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n"); 2124 policydb_destroy(newpolicydb); 2125 goto out; 2126 } 2127 2128 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size); 2129 if (rc) 2130 goto err; 2131 2132 rc = security_preserve_bools(newpolicydb); 2133 if (rc) { 2134 printk(KERN_ERR "SELinux: unable to preserve booleans\n"); 2135 goto err; 2136 } 2137 2138 /* Clone the SID table. */ 2139 sidtab_shutdown(&sidtab); 2140 2141 rc = sidtab_map(&sidtab, clone_sid, &newsidtab); 2142 if (rc) 2143 goto err; 2144 2145 /* 2146 * Convert the internal representations of contexts 2147 * in the new SID table. 2148 */ 2149 args.oldp = &policydb; 2150 args.newp = newpolicydb; 2151 rc = sidtab_map(&newsidtab, convert_context, &args); 2152 if (rc) { 2153 printk(KERN_ERR "SELinux: unable to convert the internal" 2154 " representation of contexts in the new SID" 2155 " table\n"); 2156 goto err; 2157 } 2158 2159 /* Save the old policydb and SID table to free later. */ 2160 memcpy(oldpolicydb, &policydb, sizeof(policydb)); 2161 sidtab_set(&oldsidtab, &sidtab); 2162 2163 /* Install the new policydb and SID table. */ 2164 write_lock_irq(&policy_rwlock); 2165 memcpy(&policydb, newpolicydb, sizeof(policydb)); 2166 sidtab_set(&sidtab, &newsidtab); 2167 security_load_policycaps(); 2168 oldmap = current_mapping; 2169 current_mapping = map; 2170 current_mapping_size = map_size; 2171 seqno = ++latest_granting; 2172 write_unlock_irq(&policy_rwlock); 2173 2174 /* Free the old policydb and SID table. */ 2175 policydb_destroy(oldpolicydb); 2176 sidtab_destroy(&oldsidtab); 2177 kfree(oldmap); 2178 2179 avc_ss_reset(seqno); 2180 selnl_notify_policyload(seqno); 2181 selinux_status_update_policyload(seqno); 2182 selinux_netlbl_cache_invalidate(); 2183 selinux_xfrm_notify_policyload(); 2184 2185 rc = 0; 2186 goto out; 2187 2188 err: 2189 kfree(map); 2190 sidtab_destroy(&newsidtab); 2191 policydb_destroy(newpolicydb); 2192 2193 out: 2194 kfree(oldpolicydb); 2195 return rc; 2196 } 2197 2198 size_t security_policydb_len(void) 2199 { 2200 size_t len; 2201 2202 read_lock(&policy_rwlock); 2203 len = policydb.len; 2204 read_unlock(&policy_rwlock); 2205 2206 return len; 2207 } 2208 2209 /** 2210 * security_port_sid - Obtain the SID for a port. 2211 * @protocol: protocol number 2212 * @port: port number 2213 * @out_sid: security identifier 2214 */ 2215 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2216 { 2217 struct ocontext *c; 2218 int rc = 0; 2219 2220 read_lock(&policy_rwlock); 2221 2222 c = policydb.ocontexts[OCON_PORT]; 2223 while (c) { 2224 if (c->u.port.protocol == protocol && 2225 c->u.port.low_port <= port && 2226 c->u.port.high_port >= port) 2227 break; 2228 c = c->next; 2229 } 2230 2231 if (c) { 2232 if (!c->sid[0]) { 2233 rc = sidtab_context_to_sid(&sidtab, 2234 &c->context[0], 2235 &c->sid[0]); 2236 if (rc) 2237 goto out; 2238 } 2239 *out_sid = c->sid[0]; 2240 } else { 2241 *out_sid = SECINITSID_PORT; 2242 } 2243 2244 out: 2245 read_unlock(&policy_rwlock); 2246 return rc; 2247 } 2248 2249 /** 2250 * security_pkey_sid - Obtain the SID for a pkey. 2251 * @subnet_prefix: Subnet Prefix 2252 * @pkey_num: pkey number 2253 * @out_sid: security identifier 2254 */ 2255 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2256 { 2257 struct ocontext *c; 2258 int rc = 0; 2259 2260 read_lock(&policy_rwlock); 2261 2262 c = policydb.ocontexts[OCON_IBPKEY]; 2263 while (c) { 2264 if (c->u.ibpkey.low_pkey <= pkey_num && 2265 c->u.ibpkey.high_pkey >= pkey_num && 2266 c->u.ibpkey.subnet_prefix == subnet_prefix) 2267 break; 2268 2269 c = c->next; 2270 } 2271 2272 if (c) { 2273 if (!c->sid[0]) { 2274 rc = sidtab_context_to_sid(&sidtab, 2275 &c->context[0], 2276 &c->sid[0]); 2277 if (rc) 2278 goto out; 2279 } 2280 *out_sid = c->sid[0]; 2281 } else 2282 *out_sid = SECINITSID_UNLABELED; 2283 2284 out: 2285 read_unlock(&policy_rwlock); 2286 return rc; 2287 } 2288 2289 /** 2290 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2291 * @dev_name: device name 2292 * @port: port number 2293 * @out_sid: security identifier 2294 */ 2295 int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) 2296 { 2297 struct ocontext *c; 2298 int rc = 0; 2299 2300 read_lock(&policy_rwlock); 2301 2302 c = policydb.ocontexts[OCON_IBENDPORT]; 2303 while (c) { 2304 if (c->u.ibendport.port == port_num && 2305 !strncmp(c->u.ibendport.dev_name, 2306 dev_name, 2307 IB_DEVICE_NAME_MAX)) 2308 break; 2309 2310 c = c->next; 2311 } 2312 2313 if (c) { 2314 if (!c->sid[0]) { 2315 rc = sidtab_context_to_sid(&sidtab, 2316 &c->context[0], 2317 &c->sid[0]); 2318 if (rc) 2319 goto out; 2320 } 2321 *out_sid = c->sid[0]; 2322 } else 2323 *out_sid = SECINITSID_UNLABELED; 2324 2325 out: 2326 read_unlock(&policy_rwlock); 2327 return rc; 2328 } 2329 2330 /** 2331 * security_netif_sid - Obtain the SID for a network interface. 2332 * @name: interface name 2333 * @if_sid: interface SID 2334 */ 2335 int security_netif_sid(char *name, u32 *if_sid) 2336 { 2337 int rc = 0; 2338 struct ocontext *c; 2339 2340 read_lock(&policy_rwlock); 2341 2342 c = policydb.ocontexts[OCON_NETIF]; 2343 while (c) { 2344 if (strcmp(name, c->u.name) == 0) 2345 break; 2346 c = c->next; 2347 } 2348 2349 if (c) { 2350 if (!c->sid[0] || !c->sid[1]) { 2351 rc = sidtab_context_to_sid(&sidtab, 2352 &c->context[0], 2353 &c->sid[0]); 2354 if (rc) 2355 goto out; 2356 rc = sidtab_context_to_sid(&sidtab, 2357 &c->context[1], 2358 &c->sid[1]); 2359 if (rc) 2360 goto out; 2361 } 2362 *if_sid = c->sid[0]; 2363 } else 2364 *if_sid = SECINITSID_NETIF; 2365 2366 out: 2367 read_unlock(&policy_rwlock); 2368 return rc; 2369 } 2370 2371 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2372 { 2373 int i, fail = 0; 2374 2375 for (i = 0; i < 4; i++) 2376 if (addr[i] != (input[i] & mask[i])) { 2377 fail = 1; 2378 break; 2379 } 2380 2381 return !fail; 2382 } 2383 2384 /** 2385 * security_node_sid - Obtain the SID for a node (host). 2386 * @domain: communication domain aka address family 2387 * @addrp: address 2388 * @addrlen: address length in bytes 2389 * @out_sid: security identifier 2390 */ 2391 int security_node_sid(u16 domain, 2392 void *addrp, 2393 u32 addrlen, 2394 u32 *out_sid) 2395 { 2396 int rc; 2397 struct ocontext *c; 2398 2399 read_lock(&policy_rwlock); 2400 2401 switch (domain) { 2402 case AF_INET: { 2403 u32 addr; 2404 2405 rc = -EINVAL; 2406 if (addrlen != sizeof(u32)) 2407 goto out; 2408 2409 addr = *((u32 *)addrp); 2410 2411 c = policydb.ocontexts[OCON_NODE]; 2412 while (c) { 2413 if (c->u.node.addr == (addr & c->u.node.mask)) 2414 break; 2415 c = c->next; 2416 } 2417 break; 2418 } 2419 2420 case AF_INET6: 2421 rc = -EINVAL; 2422 if (addrlen != sizeof(u64) * 2) 2423 goto out; 2424 c = policydb.ocontexts[OCON_NODE6]; 2425 while (c) { 2426 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2427 c->u.node6.mask)) 2428 break; 2429 c = c->next; 2430 } 2431 break; 2432 2433 default: 2434 rc = 0; 2435 *out_sid = SECINITSID_NODE; 2436 goto out; 2437 } 2438 2439 if (c) { 2440 if (!c->sid[0]) { 2441 rc = sidtab_context_to_sid(&sidtab, 2442 &c->context[0], 2443 &c->sid[0]); 2444 if (rc) 2445 goto out; 2446 } 2447 *out_sid = c->sid[0]; 2448 } else { 2449 *out_sid = SECINITSID_NODE; 2450 } 2451 2452 rc = 0; 2453 out: 2454 read_unlock(&policy_rwlock); 2455 return rc; 2456 } 2457 2458 #define SIDS_NEL 25 2459 2460 /** 2461 * security_get_user_sids - Obtain reachable SIDs for a user. 2462 * @fromsid: starting SID 2463 * @username: username 2464 * @sids: array of reachable SIDs for user 2465 * @nel: number of elements in @sids 2466 * 2467 * Generate the set of SIDs for legal security contexts 2468 * for a given user that can be reached by @fromsid. 2469 * Set *@sids to point to a dynamically allocated 2470 * array containing the set of SIDs. Set *@nel to the 2471 * number of elements in the array. 2472 */ 2473 2474 int security_get_user_sids(u32 fromsid, 2475 char *username, 2476 u32 **sids, 2477 u32 *nel) 2478 { 2479 struct context *fromcon, usercon; 2480 u32 *mysids = NULL, *mysids2, sid; 2481 u32 mynel = 0, maxnel = SIDS_NEL; 2482 struct user_datum *user; 2483 struct role_datum *role; 2484 struct ebitmap_node *rnode, *tnode; 2485 int rc = 0, i, j; 2486 2487 *sids = NULL; 2488 *nel = 0; 2489 2490 if (!ss_initialized) 2491 goto out; 2492 2493 read_lock(&policy_rwlock); 2494 2495 context_init(&usercon); 2496 2497 rc = -EINVAL; 2498 fromcon = sidtab_search(&sidtab, fromsid); 2499 if (!fromcon) 2500 goto out_unlock; 2501 2502 rc = -EINVAL; 2503 user = hashtab_search(policydb.p_users.table, username); 2504 if (!user) 2505 goto out_unlock; 2506 2507 usercon.user = user->value; 2508 2509 rc = -ENOMEM; 2510 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); 2511 if (!mysids) 2512 goto out_unlock; 2513 2514 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2515 role = policydb.role_val_to_struct[i]; 2516 usercon.role = i + 1; 2517 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2518 usercon.type = j + 1; 2519 2520 if (mls_setup_user_range(fromcon, user, &usercon)) 2521 continue; 2522 2523 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); 2524 if (rc) 2525 goto out_unlock; 2526 if (mynel < maxnel) { 2527 mysids[mynel++] = sid; 2528 } else { 2529 rc = -ENOMEM; 2530 maxnel += SIDS_NEL; 2531 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2532 if (!mysids2) 2533 goto out_unlock; 2534 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2535 kfree(mysids); 2536 mysids = mysids2; 2537 mysids[mynel++] = sid; 2538 } 2539 } 2540 } 2541 rc = 0; 2542 out_unlock: 2543 read_unlock(&policy_rwlock); 2544 if (rc || !mynel) { 2545 kfree(mysids); 2546 goto out; 2547 } 2548 2549 rc = -ENOMEM; 2550 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2551 if (!mysids2) { 2552 kfree(mysids); 2553 goto out; 2554 } 2555 for (i = 0, j = 0; i < mynel; i++) { 2556 struct av_decision dummy_avd; 2557 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2558 SECCLASS_PROCESS, /* kernel value */ 2559 PROCESS__TRANSITION, AVC_STRICT, 2560 &dummy_avd); 2561 if (!rc) 2562 mysids2[j++] = mysids[i]; 2563 cond_resched(); 2564 } 2565 rc = 0; 2566 kfree(mysids); 2567 *sids = mysids2; 2568 *nel = j; 2569 out: 2570 return rc; 2571 } 2572 2573 /** 2574 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2575 * @fstype: filesystem type 2576 * @path: path from root of mount 2577 * @sclass: file security class 2578 * @sid: SID for path 2579 * 2580 * Obtain a SID to use for a file in a filesystem that 2581 * cannot support xattr or use a fixed labeling behavior like 2582 * transition SIDs or task SIDs. 2583 * 2584 * The caller must acquire the policy_rwlock before calling this function. 2585 */ 2586 static inline int __security_genfs_sid(const char *fstype, 2587 char *path, 2588 u16 orig_sclass, 2589 u32 *sid) 2590 { 2591 int len; 2592 u16 sclass; 2593 struct genfs *genfs; 2594 struct ocontext *c; 2595 int rc, cmp = 0; 2596 2597 while (path[0] == '/' && path[1] == '/') 2598 path++; 2599 2600 sclass = unmap_class(orig_sclass); 2601 *sid = SECINITSID_UNLABELED; 2602 2603 for (genfs = policydb.genfs; genfs; genfs = genfs->next) { 2604 cmp = strcmp(fstype, genfs->fstype); 2605 if (cmp <= 0) 2606 break; 2607 } 2608 2609 rc = -ENOENT; 2610 if (!genfs || cmp) 2611 goto out; 2612 2613 for (c = genfs->head; c; c = c->next) { 2614 len = strlen(c->u.name); 2615 if ((!c->v.sclass || sclass == c->v.sclass) && 2616 (strncmp(c->u.name, path, len) == 0)) 2617 break; 2618 } 2619 2620 rc = -ENOENT; 2621 if (!c) 2622 goto out; 2623 2624 if (!c->sid[0]) { 2625 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); 2626 if (rc) 2627 goto out; 2628 } 2629 2630 *sid = c->sid[0]; 2631 rc = 0; 2632 out: 2633 return rc; 2634 } 2635 2636 /** 2637 * security_genfs_sid - Obtain a SID for a file in a filesystem 2638 * @fstype: filesystem type 2639 * @path: path from root of mount 2640 * @sclass: file security class 2641 * @sid: SID for path 2642 * 2643 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2644 * it afterward. 2645 */ 2646 int security_genfs_sid(const char *fstype, 2647 char *path, 2648 u16 orig_sclass, 2649 u32 *sid) 2650 { 2651 int retval; 2652 2653 read_lock(&policy_rwlock); 2654 retval = __security_genfs_sid(fstype, path, orig_sclass, sid); 2655 read_unlock(&policy_rwlock); 2656 return retval; 2657 } 2658 2659 /** 2660 * security_fs_use - Determine how to handle labeling for a filesystem. 2661 * @sb: superblock in question 2662 */ 2663 int security_fs_use(struct super_block *sb) 2664 { 2665 int rc = 0; 2666 struct ocontext *c; 2667 struct superblock_security_struct *sbsec = sb->s_security; 2668 const char *fstype = sb->s_type->name; 2669 2670 read_lock(&policy_rwlock); 2671 2672 c = policydb.ocontexts[OCON_FSUSE]; 2673 while (c) { 2674 if (strcmp(fstype, c->u.name) == 0) 2675 break; 2676 c = c->next; 2677 } 2678 2679 if (c) { 2680 sbsec->behavior = c->v.behavior; 2681 if (!c->sid[0]) { 2682 rc = sidtab_context_to_sid(&sidtab, &c->context[0], 2683 &c->sid[0]); 2684 if (rc) 2685 goto out; 2686 } 2687 sbsec->sid = c->sid[0]; 2688 } else { 2689 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR, 2690 &sbsec->sid); 2691 if (rc) { 2692 sbsec->behavior = SECURITY_FS_USE_NONE; 2693 rc = 0; 2694 } else { 2695 sbsec->behavior = SECURITY_FS_USE_GENFS; 2696 } 2697 } 2698 2699 out: 2700 read_unlock(&policy_rwlock); 2701 return rc; 2702 } 2703 2704 int security_get_bools(int *len, char ***names, int **values) 2705 { 2706 int i, rc; 2707 2708 read_lock(&policy_rwlock); 2709 *names = NULL; 2710 *values = NULL; 2711 2712 rc = 0; 2713 *len = policydb.p_bools.nprim; 2714 if (!*len) 2715 goto out; 2716 2717 rc = -ENOMEM; 2718 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2719 if (!*names) 2720 goto err; 2721 2722 rc = -ENOMEM; 2723 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2724 if (!*values) 2725 goto err; 2726 2727 for (i = 0; i < *len; i++) { 2728 (*values)[i] = policydb.bool_val_to_struct[i]->state; 2729 2730 rc = -ENOMEM; 2731 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC); 2732 if (!(*names)[i]) 2733 goto err; 2734 } 2735 rc = 0; 2736 out: 2737 read_unlock(&policy_rwlock); 2738 return rc; 2739 err: 2740 if (*names) { 2741 for (i = 0; i < *len; i++) 2742 kfree((*names)[i]); 2743 } 2744 kfree(*values); 2745 goto out; 2746 } 2747 2748 2749 int security_set_bools(int len, int *values) 2750 { 2751 int i, rc; 2752 int lenp, seqno = 0; 2753 struct cond_node *cur; 2754 2755 write_lock_irq(&policy_rwlock); 2756 2757 rc = -EFAULT; 2758 lenp = policydb.p_bools.nprim; 2759 if (len != lenp) 2760 goto out; 2761 2762 for (i = 0; i < len; i++) { 2763 if (!!values[i] != policydb.bool_val_to_struct[i]->state) { 2764 audit_log(current->audit_context, GFP_ATOMIC, 2765 AUDIT_MAC_CONFIG_CHANGE, 2766 "bool=%s val=%d old_val=%d auid=%u ses=%u", 2767 sym_name(&policydb, SYM_BOOLS, i), 2768 !!values[i], 2769 policydb.bool_val_to_struct[i]->state, 2770 from_kuid(&init_user_ns, audit_get_loginuid(current)), 2771 audit_get_sessionid(current)); 2772 } 2773 if (values[i]) 2774 policydb.bool_val_to_struct[i]->state = 1; 2775 else 2776 policydb.bool_val_to_struct[i]->state = 0; 2777 } 2778 2779 for (cur = policydb.cond_list; cur; cur = cur->next) { 2780 rc = evaluate_cond_node(&policydb, cur); 2781 if (rc) 2782 goto out; 2783 } 2784 2785 seqno = ++latest_granting; 2786 rc = 0; 2787 out: 2788 write_unlock_irq(&policy_rwlock); 2789 if (!rc) { 2790 avc_ss_reset(seqno); 2791 selnl_notify_policyload(seqno); 2792 selinux_status_update_policyload(seqno); 2793 selinux_xfrm_notify_policyload(); 2794 } 2795 return rc; 2796 } 2797 2798 int security_get_bool_value(int index) 2799 { 2800 int rc; 2801 int len; 2802 2803 read_lock(&policy_rwlock); 2804 2805 rc = -EFAULT; 2806 len = policydb.p_bools.nprim; 2807 if (index >= len) 2808 goto out; 2809 2810 rc = policydb.bool_val_to_struct[index]->state; 2811 out: 2812 read_unlock(&policy_rwlock); 2813 return rc; 2814 } 2815 2816 static int security_preserve_bools(struct policydb *p) 2817 { 2818 int rc, nbools = 0, *bvalues = NULL, i; 2819 char **bnames = NULL; 2820 struct cond_bool_datum *booldatum; 2821 struct cond_node *cur; 2822 2823 rc = security_get_bools(&nbools, &bnames, &bvalues); 2824 if (rc) 2825 goto out; 2826 for (i = 0; i < nbools; i++) { 2827 booldatum = hashtab_search(p->p_bools.table, bnames[i]); 2828 if (booldatum) 2829 booldatum->state = bvalues[i]; 2830 } 2831 for (cur = p->cond_list; cur; cur = cur->next) { 2832 rc = evaluate_cond_node(p, cur); 2833 if (rc) 2834 goto out; 2835 } 2836 2837 out: 2838 if (bnames) { 2839 for (i = 0; i < nbools; i++) 2840 kfree(bnames[i]); 2841 } 2842 kfree(bnames); 2843 kfree(bvalues); 2844 return rc; 2845 } 2846 2847 /* 2848 * security_sid_mls_copy() - computes a new sid based on the given 2849 * sid and the mls portion of mls_sid. 2850 */ 2851 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 2852 { 2853 struct context *context1; 2854 struct context *context2; 2855 struct context newcon; 2856 char *s; 2857 u32 len; 2858 int rc; 2859 2860 rc = 0; 2861 if (!ss_initialized || !policydb.mls_enabled) { 2862 *new_sid = sid; 2863 goto out; 2864 } 2865 2866 context_init(&newcon); 2867 2868 read_lock(&policy_rwlock); 2869 2870 rc = -EINVAL; 2871 context1 = sidtab_search(&sidtab, sid); 2872 if (!context1) { 2873 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2874 __func__, sid); 2875 goto out_unlock; 2876 } 2877 2878 rc = -EINVAL; 2879 context2 = sidtab_search(&sidtab, mls_sid); 2880 if (!context2) { 2881 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2882 __func__, mls_sid); 2883 goto out_unlock; 2884 } 2885 2886 newcon.user = context1->user; 2887 newcon.role = context1->role; 2888 newcon.type = context1->type; 2889 rc = mls_context_cpy(&newcon, context2); 2890 if (rc) 2891 goto out_unlock; 2892 2893 /* Check the validity of the new context. */ 2894 if (!policydb_context_isvalid(&policydb, &newcon)) { 2895 rc = convert_context_handle_invalid_context(&newcon); 2896 if (rc) { 2897 if (!context_struct_to_string(&newcon, &s, &len)) { 2898 audit_log(current->audit_context, 2899 GFP_ATOMIC, AUDIT_SELINUX_ERR, 2900 "op=security_sid_mls_copy " 2901 "invalid_context=%s", s); 2902 kfree(s); 2903 } 2904 goto out_unlock; 2905 } 2906 } 2907 2908 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid); 2909 out_unlock: 2910 read_unlock(&policy_rwlock); 2911 context_destroy(&newcon); 2912 out: 2913 return rc; 2914 } 2915 2916 /** 2917 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 2918 * @nlbl_sid: NetLabel SID 2919 * @nlbl_type: NetLabel labeling protocol type 2920 * @xfrm_sid: XFRM SID 2921 * 2922 * Description: 2923 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 2924 * resolved into a single SID it is returned via @peer_sid and the function 2925 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 2926 * returns a negative value. A table summarizing the behavior is below: 2927 * 2928 * | function return | @sid 2929 * ------------------------------+-----------------+----------------- 2930 * no peer labels | 0 | SECSID_NULL 2931 * single peer label | 0 | <peer_label> 2932 * multiple, consistent labels | 0 | <peer_label> 2933 * multiple, inconsistent labels | -<errno> | SECSID_NULL 2934 * 2935 */ 2936 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 2937 u32 xfrm_sid, 2938 u32 *peer_sid) 2939 { 2940 int rc; 2941 struct context *nlbl_ctx; 2942 struct context *xfrm_ctx; 2943 2944 *peer_sid = SECSID_NULL; 2945 2946 /* handle the common (which also happens to be the set of easy) cases 2947 * right away, these two if statements catch everything involving a 2948 * single or absent peer SID/label */ 2949 if (xfrm_sid == SECSID_NULL) { 2950 *peer_sid = nlbl_sid; 2951 return 0; 2952 } 2953 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 2954 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 2955 * is present */ 2956 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 2957 *peer_sid = xfrm_sid; 2958 return 0; 2959 } 2960 2961 /* we don't need to check ss_initialized here since the only way both 2962 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 2963 * security server was initialized and ss_initialized was true */ 2964 if (!policydb.mls_enabled) 2965 return 0; 2966 2967 read_lock(&policy_rwlock); 2968 2969 rc = -EINVAL; 2970 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid); 2971 if (!nlbl_ctx) { 2972 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2973 __func__, nlbl_sid); 2974 goto out; 2975 } 2976 rc = -EINVAL; 2977 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid); 2978 if (!xfrm_ctx) { 2979 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2980 __func__, xfrm_sid); 2981 goto out; 2982 } 2983 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 2984 if (rc) 2985 goto out; 2986 2987 /* at present NetLabel SIDs/labels really only carry MLS 2988 * information so if the MLS portion of the NetLabel SID 2989 * matches the MLS portion of the labeled XFRM SID/label 2990 * then pass along the XFRM SID as it is the most 2991 * expressive */ 2992 *peer_sid = xfrm_sid; 2993 out: 2994 read_unlock(&policy_rwlock); 2995 return rc; 2996 } 2997 2998 static int get_classes_callback(void *k, void *d, void *args) 2999 { 3000 struct class_datum *datum = d; 3001 char *name = k, **classes = args; 3002 int value = datum->value - 1; 3003 3004 classes[value] = kstrdup(name, GFP_ATOMIC); 3005 if (!classes[value]) 3006 return -ENOMEM; 3007 3008 return 0; 3009 } 3010 3011 int security_get_classes(char ***classes, int *nclasses) 3012 { 3013 int rc; 3014 3015 read_lock(&policy_rwlock); 3016 3017 rc = -ENOMEM; 3018 *nclasses = policydb.p_classes.nprim; 3019 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3020 if (!*classes) 3021 goto out; 3022 3023 rc = hashtab_map(policydb.p_classes.table, get_classes_callback, 3024 *classes); 3025 if (rc) { 3026 int i; 3027 for (i = 0; i < *nclasses; i++) 3028 kfree((*classes)[i]); 3029 kfree(*classes); 3030 } 3031 3032 out: 3033 read_unlock(&policy_rwlock); 3034 return rc; 3035 } 3036 3037 static int get_permissions_callback(void *k, void *d, void *args) 3038 { 3039 struct perm_datum *datum = d; 3040 char *name = k, **perms = args; 3041 int value = datum->value - 1; 3042 3043 perms[value] = kstrdup(name, GFP_ATOMIC); 3044 if (!perms[value]) 3045 return -ENOMEM; 3046 3047 return 0; 3048 } 3049 3050 int security_get_permissions(char *class, char ***perms, int *nperms) 3051 { 3052 int rc, i; 3053 struct class_datum *match; 3054 3055 read_lock(&policy_rwlock); 3056 3057 rc = -EINVAL; 3058 match = hashtab_search(policydb.p_classes.table, class); 3059 if (!match) { 3060 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n", 3061 __func__, class); 3062 goto out; 3063 } 3064 3065 rc = -ENOMEM; 3066 *nperms = match->permissions.nprim; 3067 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3068 if (!*perms) 3069 goto out; 3070 3071 if (match->comdatum) { 3072 rc = hashtab_map(match->comdatum->permissions.table, 3073 get_permissions_callback, *perms); 3074 if (rc) 3075 goto err; 3076 } 3077 3078 rc = hashtab_map(match->permissions.table, get_permissions_callback, 3079 *perms); 3080 if (rc) 3081 goto err; 3082 3083 out: 3084 read_unlock(&policy_rwlock); 3085 return rc; 3086 3087 err: 3088 read_unlock(&policy_rwlock); 3089 for (i = 0; i < *nperms; i++) 3090 kfree((*perms)[i]); 3091 kfree(*perms); 3092 return rc; 3093 } 3094 3095 int security_get_reject_unknown(void) 3096 { 3097 return policydb.reject_unknown; 3098 } 3099 3100 int security_get_allow_unknown(void) 3101 { 3102 return policydb.allow_unknown; 3103 } 3104 3105 /** 3106 * security_policycap_supported - Check for a specific policy capability 3107 * @req_cap: capability 3108 * 3109 * Description: 3110 * This function queries the currently loaded policy to see if it supports the 3111 * capability specified by @req_cap. Returns true (1) if the capability is 3112 * supported, false (0) if it isn't supported. 3113 * 3114 */ 3115 int security_policycap_supported(unsigned int req_cap) 3116 { 3117 int rc; 3118 3119 read_lock(&policy_rwlock); 3120 rc = ebitmap_get_bit(&policydb.policycaps, req_cap); 3121 read_unlock(&policy_rwlock); 3122 3123 return rc; 3124 } 3125 3126 struct selinux_audit_rule { 3127 u32 au_seqno; 3128 struct context au_ctxt; 3129 }; 3130 3131 void selinux_audit_rule_free(void *vrule) 3132 { 3133 struct selinux_audit_rule *rule = vrule; 3134 3135 if (rule) { 3136 context_destroy(&rule->au_ctxt); 3137 kfree(rule); 3138 } 3139 } 3140 3141 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3142 { 3143 struct selinux_audit_rule *tmprule; 3144 struct role_datum *roledatum; 3145 struct type_datum *typedatum; 3146 struct user_datum *userdatum; 3147 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3148 int rc = 0; 3149 3150 *rule = NULL; 3151 3152 if (!ss_initialized) 3153 return -EOPNOTSUPP; 3154 3155 switch (field) { 3156 case AUDIT_SUBJ_USER: 3157 case AUDIT_SUBJ_ROLE: 3158 case AUDIT_SUBJ_TYPE: 3159 case AUDIT_OBJ_USER: 3160 case AUDIT_OBJ_ROLE: 3161 case AUDIT_OBJ_TYPE: 3162 /* only 'equals' and 'not equals' fit user, role, and type */ 3163 if (op != Audit_equal && op != Audit_not_equal) 3164 return -EINVAL; 3165 break; 3166 case AUDIT_SUBJ_SEN: 3167 case AUDIT_SUBJ_CLR: 3168 case AUDIT_OBJ_LEV_LOW: 3169 case AUDIT_OBJ_LEV_HIGH: 3170 /* we do not allow a range, indicated by the presence of '-' */ 3171 if (strchr(rulestr, '-')) 3172 return -EINVAL; 3173 break; 3174 default: 3175 /* only the above fields are valid */ 3176 return -EINVAL; 3177 } 3178 3179 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3180 if (!tmprule) 3181 return -ENOMEM; 3182 3183 context_init(&tmprule->au_ctxt); 3184 3185 read_lock(&policy_rwlock); 3186 3187 tmprule->au_seqno = latest_granting; 3188 3189 switch (field) { 3190 case AUDIT_SUBJ_USER: 3191 case AUDIT_OBJ_USER: 3192 rc = -EINVAL; 3193 userdatum = hashtab_search(policydb.p_users.table, rulestr); 3194 if (!userdatum) 3195 goto out; 3196 tmprule->au_ctxt.user = userdatum->value; 3197 break; 3198 case AUDIT_SUBJ_ROLE: 3199 case AUDIT_OBJ_ROLE: 3200 rc = -EINVAL; 3201 roledatum = hashtab_search(policydb.p_roles.table, rulestr); 3202 if (!roledatum) 3203 goto out; 3204 tmprule->au_ctxt.role = roledatum->value; 3205 break; 3206 case AUDIT_SUBJ_TYPE: 3207 case AUDIT_OBJ_TYPE: 3208 rc = -EINVAL; 3209 typedatum = hashtab_search(policydb.p_types.table, rulestr); 3210 if (!typedatum) 3211 goto out; 3212 tmprule->au_ctxt.type = typedatum->value; 3213 break; 3214 case AUDIT_SUBJ_SEN: 3215 case AUDIT_SUBJ_CLR: 3216 case AUDIT_OBJ_LEV_LOW: 3217 case AUDIT_OBJ_LEV_HIGH: 3218 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC); 3219 if (rc) 3220 goto out; 3221 break; 3222 } 3223 rc = 0; 3224 out: 3225 read_unlock(&policy_rwlock); 3226 3227 if (rc) { 3228 selinux_audit_rule_free(tmprule); 3229 tmprule = NULL; 3230 } 3231 3232 *rule = tmprule; 3233 3234 return rc; 3235 } 3236 3237 /* Check to see if the rule contains any selinux fields */ 3238 int selinux_audit_rule_known(struct audit_krule *rule) 3239 { 3240 int i; 3241 3242 for (i = 0; i < rule->field_count; i++) { 3243 struct audit_field *f = &rule->fields[i]; 3244 switch (f->type) { 3245 case AUDIT_SUBJ_USER: 3246 case AUDIT_SUBJ_ROLE: 3247 case AUDIT_SUBJ_TYPE: 3248 case AUDIT_SUBJ_SEN: 3249 case AUDIT_SUBJ_CLR: 3250 case AUDIT_OBJ_USER: 3251 case AUDIT_OBJ_ROLE: 3252 case AUDIT_OBJ_TYPE: 3253 case AUDIT_OBJ_LEV_LOW: 3254 case AUDIT_OBJ_LEV_HIGH: 3255 return 1; 3256 } 3257 } 3258 3259 return 0; 3260 } 3261 3262 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, 3263 struct audit_context *actx) 3264 { 3265 struct context *ctxt; 3266 struct mls_level *level; 3267 struct selinux_audit_rule *rule = vrule; 3268 int match = 0; 3269 3270 if (unlikely(!rule)) { 3271 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3272 return -ENOENT; 3273 } 3274 3275 read_lock(&policy_rwlock); 3276 3277 if (rule->au_seqno < latest_granting) { 3278 match = -ESTALE; 3279 goto out; 3280 } 3281 3282 ctxt = sidtab_search(&sidtab, sid); 3283 if (unlikely(!ctxt)) { 3284 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3285 sid); 3286 match = -ENOENT; 3287 goto out; 3288 } 3289 3290 /* a field/op pair that is not caught here will simply fall through 3291 without a match */ 3292 switch (field) { 3293 case AUDIT_SUBJ_USER: 3294 case AUDIT_OBJ_USER: 3295 switch (op) { 3296 case Audit_equal: 3297 match = (ctxt->user == rule->au_ctxt.user); 3298 break; 3299 case Audit_not_equal: 3300 match = (ctxt->user != rule->au_ctxt.user); 3301 break; 3302 } 3303 break; 3304 case AUDIT_SUBJ_ROLE: 3305 case AUDIT_OBJ_ROLE: 3306 switch (op) { 3307 case Audit_equal: 3308 match = (ctxt->role == rule->au_ctxt.role); 3309 break; 3310 case Audit_not_equal: 3311 match = (ctxt->role != rule->au_ctxt.role); 3312 break; 3313 } 3314 break; 3315 case AUDIT_SUBJ_TYPE: 3316 case AUDIT_OBJ_TYPE: 3317 switch (op) { 3318 case Audit_equal: 3319 match = (ctxt->type == rule->au_ctxt.type); 3320 break; 3321 case Audit_not_equal: 3322 match = (ctxt->type != rule->au_ctxt.type); 3323 break; 3324 } 3325 break; 3326 case AUDIT_SUBJ_SEN: 3327 case AUDIT_SUBJ_CLR: 3328 case AUDIT_OBJ_LEV_LOW: 3329 case AUDIT_OBJ_LEV_HIGH: 3330 level = ((field == AUDIT_SUBJ_SEN || 3331 field == AUDIT_OBJ_LEV_LOW) ? 3332 &ctxt->range.level[0] : &ctxt->range.level[1]); 3333 switch (op) { 3334 case Audit_equal: 3335 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3336 level); 3337 break; 3338 case Audit_not_equal: 3339 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3340 level); 3341 break; 3342 case Audit_lt: 3343 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3344 level) && 3345 !mls_level_eq(&rule->au_ctxt.range.level[0], 3346 level)); 3347 break; 3348 case Audit_le: 3349 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3350 level); 3351 break; 3352 case Audit_gt: 3353 match = (mls_level_dom(level, 3354 &rule->au_ctxt.range.level[0]) && 3355 !mls_level_eq(level, 3356 &rule->au_ctxt.range.level[0])); 3357 break; 3358 case Audit_ge: 3359 match = mls_level_dom(level, 3360 &rule->au_ctxt.range.level[0]); 3361 break; 3362 } 3363 } 3364 3365 out: 3366 read_unlock(&policy_rwlock); 3367 return match; 3368 } 3369 3370 static int (*aurule_callback)(void) = audit_update_lsm_rules; 3371 3372 static int aurule_avc_callback(u32 event) 3373 { 3374 int err = 0; 3375 3376 if (event == AVC_CALLBACK_RESET && aurule_callback) 3377 err = aurule_callback(); 3378 return err; 3379 } 3380 3381 static int __init aurule_init(void) 3382 { 3383 int err; 3384 3385 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3386 if (err) 3387 panic("avc_add_callback() failed, error %d\n", err); 3388 3389 return err; 3390 } 3391 __initcall(aurule_init); 3392 3393 #ifdef CONFIG_NETLABEL 3394 /** 3395 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3396 * @secattr: the NetLabel packet security attributes 3397 * @sid: the SELinux SID 3398 * 3399 * Description: 3400 * Attempt to cache the context in @ctx, which was derived from the packet in 3401 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3402 * already been initialized. 3403 * 3404 */ 3405 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3406 u32 sid) 3407 { 3408 u32 *sid_cache; 3409 3410 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3411 if (sid_cache == NULL) 3412 return; 3413 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3414 if (secattr->cache == NULL) { 3415 kfree(sid_cache); 3416 return; 3417 } 3418 3419 *sid_cache = sid; 3420 secattr->cache->free = kfree; 3421 secattr->cache->data = sid_cache; 3422 secattr->flags |= NETLBL_SECATTR_CACHE; 3423 } 3424 3425 /** 3426 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3427 * @secattr: the NetLabel packet security attributes 3428 * @sid: the SELinux SID 3429 * 3430 * Description: 3431 * Convert the given NetLabel security attributes in @secattr into a 3432 * SELinux SID. If the @secattr field does not contain a full SELinux 3433 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3434 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3435 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3436 * conversion for future lookups. Returns zero on success, negative values on 3437 * failure. 3438 * 3439 */ 3440 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3441 u32 *sid) 3442 { 3443 int rc; 3444 struct context *ctx; 3445 struct context ctx_new; 3446 3447 if (!ss_initialized) { 3448 *sid = SECSID_NULL; 3449 return 0; 3450 } 3451 3452 read_lock(&policy_rwlock); 3453 3454 if (secattr->flags & NETLBL_SECATTR_CACHE) 3455 *sid = *(u32 *)secattr->cache->data; 3456 else if (secattr->flags & NETLBL_SECATTR_SECID) 3457 *sid = secattr->attr.secid; 3458 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3459 rc = -EIDRM; 3460 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG); 3461 if (ctx == NULL) 3462 goto out; 3463 3464 context_init(&ctx_new); 3465 ctx_new.user = ctx->user; 3466 ctx_new.role = ctx->role; 3467 ctx_new.type = ctx->type; 3468 mls_import_netlbl_lvl(&ctx_new, secattr); 3469 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3470 rc = mls_import_netlbl_cat(&ctx_new, secattr); 3471 if (rc) 3472 goto out; 3473 } 3474 rc = -EIDRM; 3475 if (!mls_context_isvalid(&policydb, &ctx_new)) 3476 goto out_free; 3477 3478 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); 3479 if (rc) 3480 goto out_free; 3481 3482 security_netlbl_cache_add(secattr, *sid); 3483 3484 ebitmap_destroy(&ctx_new.range.level[0].cat); 3485 } else 3486 *sid = SECSID_NULL; 3487 3488 read_unlock(&policy_rwlock); 3489 return 0; 3490 out_free: 3491 ebitmap_destroy(&ctx_new.range.level[0].cat); 3492 out: 3493 read_unlock(&policy_rwlock); 3494 return rc; 3495 } 3496 3497 /** 3498 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3499 * @sid: the SELinux SID 3500 * @secattr: the NetLabel packet security attributes 3501 * 3502 * Description: 3503 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3504 * Returns zero on success, negative values on failure. 3505 * 3506 */ 3507 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3508 { 3509 int rc; 3510 struct context *ctx; 3511 3512 if (!ss_initialized) 3513 return 0; 3514 3515 read_lock(&policy_rwlock); 3516 3517 rc = -ENOENT; 3518 ctx = sidtab_search(&sidtab, sid); 3519 if (ctx == NULL) 3520 goto out; 3521 3522 rc = -ENOMEM; 3523 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1), 3524 GFP_ATOMIC); 3525 if (secattr->domain == NULL) 3526 goto out; 3527 3528 secattr->attr.secid = sid; 3529 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3530 mls_export_netlbl_lvl(ctx, secattr); 3531 rc = mls_export_netlbl_cat(ctx, secattr); 3532 out: 3533 read_unlock(&policy_rwlock); 3534 return rc; 3535 } 3536 #endif /* CONFIG_NETLABEL */ 3537 3538 /** 3539 * security_read_policy - read the policy. 3540 * @data: binary policy data 3541 * @len: length of data in bytes 3542 * 3543 */ 3544 int security_read_policy(void **data, size_t *len) 3545 { 3546 int rc; 3547 struct policy_file fp; 3548 3549 if (!ss_initialized) 3550 return -EINVAL; 3551 3552 *len = security_policydb_len(); 3553 3554 *data = vmalloc_user(*len); 3555 if (!*data) 3556 return -ENOMEM; 3557 3558 fp.data = *data; 3559 fp.len = *len; 3560 3561 read_lock(&policy_rwlock); 3562 rc = policydb_write(&policydb, &fp); 3563 read_unlock(&policy_rwlock); 3564 3565 if (rc) 3566 return rc; 3567 3568 *len = (unsigned long)fp.data - (unsigned long)*data; 3569 return 0; 3570 3571 } 3572