1 /* 2 * Implementation of the security services. 3 * 4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil> 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 int selinux_policycap_netpeer; 74 int selinux_policycap_openperm; 75 int selinux_policycap_alwaysnetwork; 76 77 static DEFINE_RWLOCK(policy_rwlock); 78 79 static struct sidtab sidtab; 80 struct policydb policydb; 81 int ss_initialized; 82 83 /* 84 * The largest sequence number that has been used when 85 * providing an access decision to the access vector cache. 86 * The sequence number only changes when a policy change 87 * occurs. 88 */ 89 static u32 latest_granting; 90 91 /* Forward declaration. */ 92 static int context_struct_to_string(struct context *context, char **scontext, 93 u32 *scontext_len); 94 95 static void context_struct_compute_av(struct context *scontext, 96 struct context *tcontext, 97 u16 tclass, 98 struct av_decision *avd, 99 struct extended_perms *xperms); 100 101 struct selinux_mapping { 102 u16 value; /* policy value */ 103 unsigned num_perms; 104 u32 perms[sizeof(u32) * 8]; 105 }; 106 107 static struct selinux_mapping *current_mapping; 108 static u16 current_mapping_size; 109 110 static int selinux_set_mapping(struct policydb *pol, 111 struct security_class_mapping *map, 112 struct selinux_mapping **out_map_p, 113 u16 *out_map_size) 114 { 115 struct selinux_mapping *out_map = NULL; 116 size_t size = sizeof(struct selinux_mapping); 117 u16 i, j; 118 unsigned k; 119 bool print_unknown_handle = false; 120 121 /* Find number of classes in the input mapping */ 122 if (!map) 123 return -EINVAL; 124 i = 0; 125 while (map[i].name) 126 i++; 127 128 /* Allocate space for the class records, plus one for class zero */ 129 out_map = kcalloc(++i, size, GFP_ATOMIC); 130 if (!out_map) 131 return -ENOMEM; 132 133 /* Store the raw class and permission values */ 134 j = 0; 135 while (map[j].name) { 136 struct security_class_mapping *p_in = map + (j++); 137 struct selinux_mapping *p_out = out_map + j; 138 139 /* An empty class string skips ahead */ 140 if (!strcmp(p_in->name, "")) { 141 p_out->num_perms = 0; 142 continue; 143 } 144 145 p_out->value = string_to_security_class(pol, p_in->name); 146 if (!p_out->value) { 147 printk(KERN_INFO 148 "SELinux: Class %s not defined in policy.\n", 149 p_in->name); 150 if (pol->reject_unknown) 151 goto err; 152 p_out->num_perms = 0; 153 print_unknown_handle = true; 154 continue; 155 } 156 157 k = 0; 158 while (p_in->perms && p_in->perms[k]) { 159 /* An empty permission string skips ahead */ 160 if (!*p_in->perms[k]) { 161 k++; 162 continue; 163 } 164 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 165 p_in->perms[k]); 166 if (!p_out->perms[k]) { 167 printk(KERN_INFO 168 "SELinux: Permission %s in class %s not defined in policy.\n", 169 p_in->perms[k], p_in->name); 170 if (pol->reject_unknown) 171 goto err; 172 print_unknown_handle = true; 173 } 174 175 k++; 176 } 177 p_out->num_perms = k; 178 } 179 180 if (print_unknown_handle) 181 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n", 182 pol->allow_unknown ? "allowed" : "denied"); 183 184 *out_map_p = out_map; 185 *out_map_size = i; 186 return 0; 187 err: 188 kfree(out_map); 189 return -EINVAL; 190 } 191 192 /* 193 * Get real, policy values from mapped values 194 */ 195 196 static u16 unmap_class(u16 tclass) 197 { 198 if (tclass < current_mapping_size) 199 return current_mapping[tclass].value; 200 201 return tclass; 202 } 203 204 /* 205 * Get kernel value for class from its policy value 206 */ 207 static u16 map_class(u16 pol_value) 208 { 209 u16 i; 210 211 for (i = 1; i < current_mapping_size; i++) { 212 if (current_mapping[i].value == pol_value) 213 return i; 214 } 215 216 return SECCLASS_NULL; 217 } 218 219 static void map_decision(u16 tclass, struct av_decision *avd, 220 int allow_unknown) 221 { 222 if (tclass < current_mapping_size) { 223 unsigned i, n = current_mapping[tclass].num_perms; 224 u32 result; 225 226 for (i = 0, result = 0; i < n; i++) { 227 if (avd->allowed & current_mapping[tclass].perms[i]) 228 result |= 1<<i; 229 if (allow_unknown && !current_mapping[tclass].perms[i]) 230 result |= 1<<i; 231 } 232 avd->allowed = result; 233 234 for (i = 0, result = 0; i < n; i++) 235 if (avd->auditallow & current_mapping[tclass].perms[i]) 236 result |= 1<<i; 237 avd->auditallow = result; 238 239 for (i = 0, result = 0; i < n; i++) { 240 if (avd->auditdeny & current_mapping[tclass].perms[i]) 241 result |= 1<<i; 242 if (!allow_unknown && !current_mapping[tclass].perms[i]) 243 result |= 1<<i; 244 } 245 /* 246 * In case the kernel has a bug and requests a permission 247 * between num_perms and the maximum permission number, we 248 * should audit that denial 249 */ 250 for (; i < (sizeof(u32)*8); i++) 251 result |= 1<<i; 252 avd->auditdeny = result; 253 } 254 } 255 256 int security_mls_enabled(void) 257 { 258 return policydb.mls_enabled; 259 } 260 261 /* 262 * Return the boolean value of a constraint expression 263 * when it is applied to the specified source and target 264 * security contexts. 265 * 266 * xcontext is a special beast... It is used by the validatetrans rules 267 * only. For these rules, scontext is the context before the transition, 268 * tcontext is the context after the transition, and xcontext is the context 269 * of the process performing the transition. All other callers of 270 * constraint_expr_eval should pass in NULL for xcontext. 271 */ 272 static int constraint_expr_eval(struct context *scontext, 273 struct context *tcontext, 274 struct context *xcontext, 275 struct constraint_expr *cexpr) 276 { 277 u32 val1, val2; 278 struct context *c; 279 struct role_datum *r1, *r2; 280 struct mls_level *l1, *l2; 281 struct constraint_expr *e; 282 int s[CEXPR_MAXDEPTH]; 283 int sp = -1; 284 285 for (e = cexpr; e; e = e->next) { 286 switch (e->expr_type) { 287 case CEXPR_NOT: 288 BUG_ON(sp < 0); 289 s[sp] = !s[sp]; 290 break; 291 case CEXPR_AND: 292 BUG_ON(sp < 1); 293 sp--; 294 s[sp] &= s[sp + 1]; 295 break; 296 case CEXPR_OR: 297 BUG_ON(sp < 1); 298 sp--; 299 s[sp] |= s[sp + 1]; 300 break; 301 case CEXPR_ATTR: 302 if (sp == (CEXPR_MAXDEPTH - 1)) 303 return 0; 304 switch (e->attr) { 305 case CEXPR_USER: 306 val1 = scontext->user; 307 val2 = tcontext->user; 308 break; 309 case CEXPR_TYPE: 310 val1 = scontext->type; 311 val2 = tcontext->type; 312 break; 313 case CEXPR_ROLE: 314 val1 = scontext->role; 315 val2 = tcontext->role; 316 r1 = policydb.role_val_to_struct[val1 - 1]; 317 r2 = policydb.role_val_to_struct[val2 - 1]; 318 switch (e->op) { 319 case CEXPR_DOM: 320 s[++sp] = ebitmap_get_bit(&r1->dominates, 321 val2 - 1); 322 continue; 323 case CEXPR_DOMBY: 324 s[++sp] = ebitmap_get_bit(&r2->dominates, 325 val1 - 1); 326 continue; 327 case CEXPR_INCOMP: 328 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 329 val2 - 1) && 330 !ebitmap_get_bit(&r2->dominates, 331 val1 - 1)); 332 continue; 333 default: 334 break; 335 } 336 break; 337 case CEXPR_L1L2: 338 l1 = &(scontext->range.level[0]); 339 l2 = &(tcontext->range.level[0]); 340 goto mls_ops; 341 case CEXPR_L1H2: 342 l1 = &(scontext->range.level[0]); 343 l2 = &(tcontext->range.level[1]); 344 goto mls_ops; 345 case CEXPR_H1L2: 346 l1 = &(scontext->range.level[1]); 347 l2 = &(tcontext->range.level[0]); 348 goto mls_ops; 349 case CEXPR_H1H2: 350 l1 = &(scontext->range.level[1]); 351 l2 = &(tcontext->range.level[1]); 352 goto mls_ops; 353 case CEXPR_L1H1: 354 l1 = &(scontext->range.level[0]); 355 l2 = &(scontext->range.level[1]); 356 goto mls_ops; 357 case CEXPR_L2H2: 358 l1 = &(tcontext->range.level[0]); 359 l2 = &(tcontext->range.level[1]); 360 goto mls_ops; 361 mls_ops: 362 switch (e->op) { 363 case CEXPR_EQ: 364 s[++sp] = mls_level_eq(l1, l2); 365 continue; 366 case CEXPR_NEQ: 367 s[++sp] = !mls_level_eq(l1, l2); 368 continue; 369 case CEXPR_DOM: 370 s[++sp] = mls_level_dom(l1, l2); 371 continue; 372 case CEXPR_DOMBY: 373 s[++sp] = mls_level_dom(l2, l1); 374 continue; 375 case CEXPR_INCOMP: 376 s[++sp] = mls_level_incomp(l2, l1); 377 continue; 378 default: 379 BUG(); 380 return 0; 381 } 382 break; 383 default: 384 BUG(); 385 return 0; 386 } 387 388 switch (e->op) { 389 case CEXPR_EQ: 390 s[++sp] = (val1 == val2); 391 break; 392 case CEXPR_NEQ: 393 s[++sp] = (val1 != val2); 394 break; 395 default: 396 BUG(); 397 return 0; 398 } 399 break; 400 case CEXPR_NAMES: 401 if (sp == (CEXPR_MAXDEPTH-1)) 402 return 0; 403 c = scontext; 404 if (e->attr & CEXPR_TARGET) 405 c = tcontext; 406 else if (e->attr & CEXPR_XTARGET) { 407 c = xcontext; 408 if (!c) { 409 BUG(); 410 return 0; 411 } 412 } 413 if (e->attr & CEXPR_USER) 414 val1 = c->user; 415 else if (e->attr & CEXPR_ROLE) 416 val1 = c->role; 417 else if (e->attr & CEXPR_TYPE) 418 val1 = c->type; 419 else { 420 BUG(); 421 return 0; 422 } 423 424 switch (e->op) { 425 case CEXPR_EQ: 426 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 427 break; 428 case CEXPR_NEQ: 429 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 430 break; 431 default: 432 BUG(); 433 return 0; 434 } 435 break; 436 default: 437 BUG(); 438 return 0; 439 } 440 } 441 442 BUG_ON(sp != 0); 443 return s[0]; 444 } 445 446 /* 447 * security_dump_masked_av - dumps masked permissions during 448 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 449 */ 450 static int dump_masked_av_helper(void *k, void *d, void *args) 451 { 452 struct perm_datum *pdatum = d; 453 char **permission_names = args; 454 455 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 456 457 permission_names[pdatum->value - 1] = (char *)k; 458 459 return 0; 460 } 461 462 static void security_dump_masked_av(struct context *scontext, 463 struct context *tcontext, 464 u16 tclass, 465 u32 permissions, 466 const char *reason) 467 { 468 struct common_datum *common_dat; 469 struct class_datum *tclass_dat; 470 struct audit_buffer *ab; 471 char *tclass_name; 472 char *scontext_name = NULL; 473 char *tcontext_name = NULL; 474 char *permission_names[32]; 475 int index; 476 u32 length; 477 bool need_comma = false; 478 479 if (!permissions) 480 return; 481 482 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1); 483 tclass_dat = policydb.class_val_to_struct[tclass - 1]; 484 common_dat = tclass_dat->comdatum; 485 486 /* init permission_names */ 487 if (common_dat && 488 hashtab_map(common_dat->permissions.table, 489 dump_masked_av_helper, permission_names) < 0) 490 goto out; 491 492 if (hashtab_map(tclass_dat->permissions.table, 493 dump_masked_av_helper, permission_names) < 0) 494 goto out; 495 496 /* get scontext/tcontext in text form */ 497 if (context_struct_to_string(scontext, 498 &scontext_name, &length) < 0) 499 goto out; 500 501 if (context_struct_to_string(tcontext, 502 &tcontext_name, &length) < 0) 503 goto out; 504 505 /* audit a message */ 506 ab = audit_log_start(current->audit_context, 507 GFP_ATOMIC, AUDIT_SELINUX_ERR); 508 if (!ab) 509 goto out; 510 511 audit_log_format(ab, "op=security_compute_av reason=%s " 512 "scontext=%s tcontext=%s tclass=%s perms=", 513 reason, scontext_name, tcontext_name, tclass_name); 514 515 for (index = 0; index < 32; index++) { 516 u32 mask = (1 << index); 517 518 if ((mask & permissions) == 0) 519 continue; 520 521 audit_log_format(ab, "%s%s", 522 need_comma ? "," : "", 523 permission_names[index] 524 ? permission_names[index] : "????"); 525 need_comma = true; 526 } 527 audit_log_end(ab); 528 out: 529 /* release scontext/tcontext */ 530 kfree(tcontext_name); 531 kfree(scontext_name); 532 533 return; 534 } 535 536 /* 537 * security_boundary_permission - drops violated permissions 538 * on boundary constraint. 539 */ 540 static void type_attribute_bounds_av(struct context *scontext, 541 struct context *tcontext, 542 u16 tclass, 543 struct av_decision *avd) 544 { 545 struct context lo_scontext; 546 struct context lo_tcontext, *tcontextp = tcontext; 547 struct av_decision lo_avd; 548 struct type_datum *source; 549 struct type_datum *target; 550 u32 masked = 0; 551 552 source = flex_array_get_ptr(policydb.type_val_to_struct_array, 553 scontext->type - 1); 554 BUG_ON(!source); 555 556 if (!source->bounds) 557 return; 558 559 target = flex_array_get_ptr(policydb.type_val_to_struct_array, 560 tcontext->type - 1); 561 BUG_ON(!target); 562 563 memset(&lo_avd, 0, sizeof(lo_avd)); 564 565 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 566 lo_scontext.type = source->bounds; 567 568 if (target->bounds) { 569 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 570 lo_tcontext.type = target->bounds; 571 tcontextp = &lo_tcontext; 572 } 573 574 context_struct_compute_av(&lo_scontext, 575 tcontextp, 576 tclass, 577 &lo_avd, 578 NULL); 579 580 masked = ~lo_avd.allowed & avd->allowed; 581 582 if (likely(!masked)) 583 return; /* no masked permission */ 584 585 /* mask violated permissions */ 586 avd->allowed &= ~masked; 587 588 /* audit masked permissions */ 589 security_dump_masked_av(scontext, tcontext, 590 tclass, masked, "bounds"); 591 } 592 593 /* 594 * flag which drivers have permissions 595 * only looking for ioctl based extended permssions 596 */ 597 void services_compute_xperms_drivers( 598 struct extended_perms *xperms, 599 struct avtab_node *node) 600 { 601 unsigned int i; 602 603 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 604 /* if one or more driver has all permissions allowed */ 605 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 606 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 607 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 608 /* if allowing permissions within a driver */ 609 security_xperm_set(xperms->drivers.p, 610 node->datum.u.xperms->driver); 611 } 612 613 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */ 614 if (node->key.specified & AVTAB_XPERMS_ALLOWED) 615 xperms->len = 1; 616 } 617 618 /* 619 * Compute access vectors and extended permissions based on a context 620 * structure pair for the permissions in a particular class. 621 */ 622 static void context_struct_compute_av(struct context *scontext, 623 struct context *tcontext, 624 u16 tclass, 625 struct av_decision *avd, 626 struct extended_perms *xperms) 627 { 628 struct constraint_node *constraint; 629 struct role_allow *ra; 630 struct avtab_key avkey; 631 struct avtab_node *node; 632 struct class_datum *tclass_datum; 633 struct ebitmap *sattr, *tattr; 634 struct ebitmap_node *snode, *tnode; 635 unsigned int i, j; 636 637 avd->allowed = 0; 638 avd->auditallow = 0; 639 avd->auditdeny = 0xffffffff; 640 if (xperms) { 641 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 642 xperms->len = 0; 643 } 644 645 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 646 if (printk_ratelimit()) 647 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass); 648 return; 649 } 650 651 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 652 653 /* 654 * If a specific type enforcement rule was defined for 655 * this permission check, then use it. 656 */ 657 avkey.target_class = tclass; 658 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 659 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1); 660 BUG_ON(!sattr); 661 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1); 662 BUG_ON(!tattr); 663 ebitmap_for_each_positive_bit(sattr, snode, i) { 664 ebitmap_for_each_positive_bit(tattr, tnode, j) { 665 avkey.source_type = i + 1; 666 avkey.target_type = j + 1; 667 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 668 node; 669 node = avtab_search_node_next(node, avkey.specified)) { 670 if (node->key.specified == AVTAB_ALLOWED) 671 avd->allowed |= node->datum.u.data; 672 else if (node->key.specified == AVTAB_AUDITALLOW) 673 avd->auditallow |= node->datum.u.data; 674 else if (node->key.specified == AVTAB_AUDITDENY) 675 avd->auditdeny &= node->datum.u.data; 676 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 677 services_compute_xperms_drivers(xperms, node); 678 } 679 680 /* Check conditional av table for additional permissions */ 681 cond_compute_av(&policydb.te_cond_avtab, &avkey, 682 avd, xperms); 683 684 } 685 } 686 687 /* 688 * Remove any permissions prohibited by a constraint (this includes 689 * the MLS policy). 690 */ 691 constraint = tclass_datum->constraints; 692 while (constraint) { 693 if ((constraint->permissions & (avd->allowed)) && 694 !constraint_expr_eval(scontext, tcontext, NULL, 695 constraint->expr)) { 696 avd->allowed &= ~(constraint->permissions); 697 } 698 constraint = constraint->next; 699 } 700 701 /* 702 * If checking process transition permission and the 703 * role is changing, then check the (current_role, new_role) 704 * pair. 705 */ 706 if (tclass == policydb.process_class && 707 (avd->allowed & policydb.process_trans_perms) && 708 scontext->role != tcontext->role) { 709 for (ra = policydb.role_allow; ra; ra = ra->next) { 710 if (scontext->role == ra->role && 711 tcontext->role == ra->new_role) 712 break; 713 } 714 if (!ra) 715 avd->allowed &= ~policydb.process_trans_perms; 716 } 717 718 /* 719 * If the given source and target types have boundary 720 * constraint, lazy checks have to mask any violated 721 * permission and notice it to userspace via audit. 722 */ 723 type_attribute_bounds_av(scontext, tcontext, 724 tclass, avd); 725 } 726 727 static int security_validtrans_handle_fail(struct context *ocontext, 728 struct context *ncontext, 729 struct context *tcontext, 730 u16 tclass) 731 { 732 char *o = NULL, *n = NULL, *t = NULL; 733 u32 olen, nlen, tlen; 734 735 if (context_struct_to_string(ocontext, &o, &olen)) 736 goto out; 737 if (context_struct_to_string(ncontext, &n, &nlen)) 738 goto out; 739 if (context_struct_to_string(tcontext, &t, &tlen)) 740 goto out; 741 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 742 "op=security_validate_transition seresult=denied" 743 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 744 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 745 out: 746 kfree(o); 747 kfree(n); 748 kfree(t); 749 750 if (!selinux_enforcing) 751 return 0; 752 return -EPERM; 753 } 754 755 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid, 756 u16 orig_tclass, bool user) 757 { 758 struct context *ocontext; 759 struct context *ncontext; 760 struct context *tcontext; 761 struct class_datum *tclass_datum; 762 struct constraint_node *constraint; 763 u16 tclass; 764 int rc = 0; 765 766 if (!ss_initialized) 767 return 0; 768 769 read_lock(&policy_rwlock); 770 771 if (!user) 772 tclass = unmap_class(orig_tclass); 773 else 774 tclass = orig_tclass; 775 776 if (!tclass || tclass > policydb.p_classes.nprim) { 777 rc = -EINVAL; 778 goto out; 779 } 780 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 781 782 ocontext = sidtab_search(&sidtab, oldsid); 783 if (!ocontext) { 784 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 785 __func__, oldsid); 786 rc = -EINVAL; 787 goto out; 788 } 789 790 ncontext = sidtab_search(&sidtab, newsid); 791 if (!ncontext) { 792 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 793 __func__, newsid); 794 rc = -EINVAL; 795 goto out; 796 } 797 798 tcontext = sidtab_search(&sidtab, tasksid); 799 if (!tcontext) { 800 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 801 __func__, tasksid); 802 rc = -EINVAL; 803 goto out; 804 } 805 806 constraint = tclass_datum->validatetrans; 807 while (constraint) { 808 if (!constraint_expr_eval(ocontext, ncontext, tcontext, 809 constraint->expr)) { 810 if (user) 811 rc = -EPERM; 812 else 813 rc = security_validtrans_handle_fail(ocontext, 814 ncontext, 815 tcontext, 816 tclass); 817 goto out; 818 } 819 constraint = constraint->next; 820 } 821 822 out: 823 read_unlock(&policy_rwlock); 824 return rc; 825 } 826 827 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, 828 u16 tclass) 829 { 830 return security_compute_validatetrans(oldsid, newsid, tasksid, 831 tclass, true); 832 } 833 834 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 835 u16 orig_tclass) 836 { 837 return security_compute_validatetrans(oldsid, newsid, tasksid, 838 orig_tclass, false); 839 } 840 841 /* 842 * security_bounded_transition - check whether the given 843 * transition is directed to bounded, or not. 844 * It returns 0, if @newsid is bounded by @oldsid. 845 * Otherwise, it returns error code. 846 * 847 * @oldsid : current security identifier 848 * @newsid : destinated security identifier 849 */ 850 int security_bounded_transition(u32 old_sid, u32 new_sid) 851 { 852 struct context *old_context, *new_context; 853 struct type_datum *type; 854 int index; 855 int rc; 856 857 read_lock(&policy_rwlock); 858 859 rc = -EINVAL; 860 old_context = sidtab_search(&sidtab, old_sid); 861 if (!old_context) { 862 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 863 __func__, old_sid); 864 goto out; 865 } 866 867 rc = -EINVAL; 868 new_context = sidtab_search(&sidtab, new_sid); 869 if (!new_context) { 870 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 871 __func__, new_sid); 872 goto out; 873 } 874 875 rc = 0; 876 /* type/domain unchanged */ 877 if (old_context->type == new_context->type) 878 goto out; 879 880 index = new_context->type; 881 while (true) { 882 type = flex_array_get_ptr(policydb.type_val_to_struct_array, 883 index - 1); 884 BUG_ON(!type); 885 886 /* not bounded anymore */ 887 rc = -EPERM; 888 if (!type->bounds) 889 break; 890 891 /* @newsid is bounded by @oldsid */ 892 rc = 0; 893 if (type->bounds == old_context->type) 894 break; 895 896 index = type->bounds; 897 } 898 899 if (rc) { 900 char *old_name = NULL; 901 char *new_name = NULL; 902 u32 length; 903 904 if (!context_struct_to_string(old_context, 905 &old_name, &length) && 906 !context_struct_to_string(new_context, 907 &new_name, &length)) { 908 audit_log(current->audit_context, 909 GFP_ATOMIC, AUDIT_SELINUX_ERR, 910 "op=security_bounded_transition " 911 "seresult=denied " 912 "oldcontext=%s newcontext=%s", 913 old_name, new_name); 914 } 915 kfree(new_name); 916 kfree(old_name); 917 } 918 out: 919 read_unlock(&policy_rwlock); 920 921 return rc; 922 } 923 924 static void avd_init(struct av_decision *avd) 925 { 926 avd->allowed = 0; 927 avd->auditallow = 0; 928 avd->auditdeny = 0xffffffff; 929 avd->seqno = latest_granting; 930 avd->flags = 0; 931 } 932 933 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 934 struct avtab_node *node) 935 { 936 unsigned int i; 937 938 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 939 if (xpermd->driver != node->datum.u.xperms->driver) 940 return; 941 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 942 if (!security_xperm_test(node->datum.u.xperms->perms.p, 943 xpermd->driver)) 944 return; 945 } else { 946 BUG(); 947 } 948 949 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 950 xpermd->used |= XPERMS_ALLOWED; 951 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 952 memset(xpermd->allowed->p, 0xff, 953 sizeof(xpermd->allowed->p)); 954 } 955 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 956 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 957 xpermd->allowed->p[i] |= 958 node->datum.u.xperms->perms.p[i]; 959 } 960 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 961 xpermd->used |= XPERMS_AUDITALLOW; 962 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 963 memset(xpermd->auditallow->p, 0xff, 964 sizeof(xpermd->auditallow->p)); 965 } 966 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 967 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 968 xpermd->auditallow->p[i] |= 969 node->datum.u.xperms->perms.p[i]; 970 } 971 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 972 xpermd->used |= XPERMS_DONTAUDIT; 973 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 974 memset(xpermd->dontaudit->p, 0xff, 975 sizeof(xpermd->dontaudit->p)); 976 } 977 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 978 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 979 xpermd->dontaudit->p[i] |= 980 node->datum.u.xperms->perms.p[i]; 981 } 982 } else { 983 BUG(); 984 } 985 } 986 987 void security_compute_xperms_decision(u32 ssid, 988 u32 tsid, 989 u16 orig_tclass, 990 u8 driver, 991 struct extended_perms_decision *xpermd) 992 { 993 u16 tclass; 994 struct context *scontext, *tcontext; 995 struct avtab_key avkey; 996 struct avtab_node *node; 997 struct ebitmap *sattr, *tattr; 998 struct ebitmap_node *snode, *tnode; 999 unsigned int i, j; 1000 1001 xpermd->driver = driver; 1002 xpermd->used = 0; 1003 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1004 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1005 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1006 1007 read_lock(&policy_rwlock); 1008 if (!ss_initialized) 1009 goto allow; 1010 1011 scontext = sidtab_search(&sidtab, ssid); 1012 if (!scontext) { 1013 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1014 __func__, ssid); 1015 goto out; 1016 } 1017 1018 tcontext = sidtab_search(&sidtab, tsid); 1019 if (!tcontext) { 1020 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1021 __func__, tsid); 1022 goto out; 1023 } 1024 1025 tclass = unmap_class(orig_tclass); 1026 if (unlikely(orig_tclass && !tclass)) { 1027 if (policydb.allow_unknown) 1028 goto allow; 1029 goto out; 1030 } 1031 1032 1033 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 1034 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1035 goto out; 1036 } 1037 1038 avkey.target_class = tclass; 1039 avkey.specified = AVTAB_XPERMS; 1040 sattr = flex_array_get(policydb.type_attr_map_array, 1041 scontext->type - 1); 1042 BUG_ON(!sattr); 1043 tattr = flex_array_get(policydb.type_attr_map_array, 1044 tcontext->type - 1); 1045 BUG_ON(!tattr); 1046 ebitmap_for_each_positive_bit(sattr, snode, i) { 1047 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1048 avkey.source_type = i + 1; 1049 avkey.target_type = j + 1; 1050 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 1051 node; 1052 node = avtab_search_node_next(node, avkey.specified)) 1053 services_compute_xperms_decision(xpermd, node); 1054 1055 cond_compute_xperms(&policydb.te_cond_avtab, 1056 &avkey, xpermd); 1057 } 1058 } 1059 out: 1060 read_unlock(&policy_rwlock); 1061 return; 1062 allow: 1063 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1064 goto out; 1065 } 1066 1067 /** 1068 * security_compute_av - Compute access vector decisions. 1069 * @ssid: source security identifier 1070 * @tsid: target security identifier 1071 * @tclass: target security class 1072 * @avd: access vector decisions 1073 * @xperms: extended permissions 1074 * 1075 * Compute a set of access vector decisions based on the 1076 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1077 */ 1078 void security_compute_av(u32 ssid, 1079 u32 tsid, 1080 u16 orig_tclass, 1081 struct av_decision *avd, 1082 struct extended_perms *xperms) 1083 { 1084 u16 tclass; 1085 struct context *scontext = NULL, *tcontext = NULL; 1086 1087 read_lock(&policy_rwlock); 1088 avd_init(avd); 1089 xperms->len = 0; 1090 if (!ss_initialized) 1091 goto allow; 1092 1093 scontext = sidtab_search(&sidtab, ssid); 1094 if (!scontext) { 1095 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1096 __func__, ssid); 1097 goto out; 1098 } 1099 1100 /* permissive domain? */ 1101 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1102 avd->flags |= AVD_FLAGS_PERMISSIVE; 1103 1104 tcontext = sidtab_search(&sidtab, tsid); 1105 if (!tcontext) { 1106 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1107 __func__, tsid); 1108 goto out; 1109 } 1110 1111 tclass = unmap_class(orig_tclass); 1112 if (unlikely(orig_tclass && !tclass)) { 1113 if (policydb.allow_unknown) 1114 goto allow; 1115 goto out; 1116 } 1117 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms); 1118 map_decision(orig_tclass, avd, policydb.allow_unknown); 1119 out: 1120 read_unlock(&policy_rwlock); 1121 return; 1122 allow: 1123 avd->allowed = 0xffffffff; 1124 goto out; 1125 } 1126 1127 void security_compute_av_user(u32 ssid, 1128 u32 tsid, 1129 u16 tclass, 1130 struct av_decision *avd) 1131 { 1132 struct context *scontext = NULL, *tcontext = NULL; 1133 1134 read_lock(&policy_rwlock); 1135 avd_init(avd); 1136 if (!ss_initialized) 1137 goto allow; 1138 1139 scontext = sidtab_search(&sidtab, ssid); 1140 if (!scontext) { 1141 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1142 __func__, ssid); 1143 goto out; 1144 } 1145 1146 /* permissive domain? */ 1147 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1148 avd->flags |= AVD_FLAGS_PERMISSIVE; 1149 1150 tcontext = sidtab_search(&sidtab, tsid); 1151 if (!tcontext) { 1152 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1153 __func__, tsid); 1154 goto out; 1155 } 1156 1157 if (unlikely(!tclass)) { 1158 if (policydb.allow_unknown) 1159 goto allow; 1160 goto out; 1161 } 1162 1163 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL); 1164 out: 1165 read_unlock(&policy_rwlock); 1166 return; 1167 allow: 1168 avd->allowed = 0xffffffff; 1169 goto out; 1170 } 1171 1172 /* 1173 * Write the security context string representation of 1174 * the context structure `context' into a dynamically 1175 * allocated string of the correct size. Set `*scontext' 1176 * to point to this string and set `*scontext_len' to 1177 * the length of the string. 1178 */ 1179 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) 1180 { 1181 char *scontextp; 1182 1183 if (scontext) 1184 *scontext = NULL; 1185 *scontext_len = 0; 1186 1187 if (context->len) { 1188 *scontext_len = context->len; 1189 if (scontext) { 1190 *scontext = kstrdup(context->str, GFP_ATOMIC); 1191 if (!(*scontext)) 1192 return -ENOMEM; 1193 } 1194 return 0; 1195 } 1196 1197 /* Compute the size of the context. */ 1198 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1; 1199 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1; 1200 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1; 1201 *scontext_len += mls_compute_context_len(context); 1202 1203 if (!scontext) 1204 return 0; 1205 1206 /* Allocate space for the context; caller must free this space. */ 1207 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1208 if (!scontextp) 1209 return -ENOMEM; 1210 *scontext = scontextp; 1211 1212 /* 1213 * Copy the user name, role name and type name into the context. 1214 */ 1215 scontextp += sprintf(scontextp, "%s:%s:%s", 1216 sym_name(&policydb, SYM_USERS, context->user - 1), 1217 sym_name(&policydb, SYM_ROLES, context->role - 1), 1218 sym_name(&policydb, SYM_TYPES, context->type - 1)); 1219 1220 mls_sid_to_context(context, &scontextp); 1221 1222 *scontextp = 0; 1223 1224 return 0; 1225 } 1226 1227 #include "initial_sid_to_string.h" 1228 1229 const char *security_get_initial_sid_context(u32 sid) 1230 { 1231 if (unlikely(sid > SECINITSID_NUM)) 1232 return NULL; 1233 return initial_sid_to_string[sid]; 1234 } 1235 1236 static int security_sid_to_context_core(u32 sid, char **scontext, 1237 u32 *scontext_len, int force) 1238 { 1239 struct context *context; 1240 int rc = 0; 1241 1242 if (scontext) 1243 *scontext = NULL; 1244 *scontext_len = 0; 1245 1246 if (!ss_initialized) { 1247 if (sid <= SECINITSID_NUM) { 1248 char *scontextp; 1249 1250 *scontext_len = strlen(initial_sid_to_string[sid]) + 1; 1251 if (!scontext) 1252 goto out; 1253 scontextp = kmemdup(initial_sid_to_string[sid], 1254 *scontext_len, GFP_ATOMIC); 1255 if (!scontextp) { 1256 rc = -ENOMEM; 1257 goto out; 1258 } 1259 *scontext = scontextp; 1260 goto out; 1261 } 1262 printk(KERN_ERR "SELinux: %s: called before initial " 1263 "load_policy on unknown SID %d\n", __func__, sid); 1264 rc = -EINVAL; 1265 goto out; 1266 } 1267 read_lock(&policy_rwlock); 1268 if (force) 1269 context = sidtab_search_force(&sidtab, sid); 1270 else 1271 context = sidtab_search(&sidtab, sid); 1272 if (!context) { 1273 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1274 __func__, sid); 1275 rc = -EINVAL; 1276 goto out_unlock; 1277 } 1278 rc = context_struct_to_string(context, scontext, scontext_len); 1279 out_unlock: 1280 read_unlock(&policy_rwlock); 1281 out: 1282 return rc; 1283 1284 } 1285 1286 /** 1287 * security_sid_to_context - Obtain a context for a given SID. 1288 * @sid: security identifier, SID 1289 * @scontext: security context 1290 * @scontext_len: length in bytes 1291 * 1292 * Write the string representation of the context associated with @sid 1293 * into a dynamically allocated string of the correct size. Set @scontext 1294 * to point to this string and set @scontext_len to the length of the string. 1295 */ 1296 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1297 { 1298 return security_sid_to_context_core(sid, scontext, scontext_len, 0); 1299 } 1300 1301 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len) 1302 { 1303 return security_sid_to_context_core(sid, scontext, scontext_len, 1); 1304 } 1305 1306 /* 1307 * Caveat: Mutates scontext. 1308 */ 1309 static int string_to_context_struct(struct policydb *pol, 1310 struct sidtab *sidtabp, 1311 char *scontext, 1312 u32 scontext_len, 1313 struct context *ctx, 1314 u32 def_sid) 1315 { 1316 struct role_datum *role; 1317 struct type_datum *typdatum; 1318 struct user_datum *usrdatum; 1319 char *scontextp, *p, oldc; 1320 int rc = 0; 1321 1322 context_init(ctx); 1323 1324 /* Parse the security context. */ 1325 1326 rc = -EINVAL; 1327 scontextp = (char *) scontext; 1328 1329 /* Extract the user. */ 1330 p = scontextp; 1331 while (*p && *p != ':') 1332 p++; 1333 1334 if (*p == 0) 1335 goto out; 1336 1337 *p++ = 0; 1338 1339 usrdatum = hashtab_search(pol->p_users.table, scontextp); 1340 if (!usrdatum) 1341 goto out; 1342 1343 ctx->user = usrdatum->value; 1344 1345 /* Extract role. */ 1346 scontextp = p; 1347 while (*p && *p != ':') 1348 p++; 1349 1350 if (*p == 0) 1351 goto out; 1352 1353 *p++ = 0; 1354 1355 role = hashtab_search(pol->p_roles.table, scontextp); 1356 if (!role) 1357 goto out; 1358 ctx->role = role->value; 1359 1360 /* Extract type. */ 1361 scontextp = p; 1362 while (*p && *p != ':') 1363 p++; 1364 oldc = *p; 1365 *p++ = 0; 1366 1367 typdatum = hashtab_search(pol->p_types.table, scontextp); 1368 if (!typdatum || typdatum->attribute) 1369 goto out; 1370 1371 ctx->type = typdatum->value; 1372 1373 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid); 1374 if (rc) 1375 goto out; 1376 1377 rc = -EINVAL; 1378 if ((p - scontext) < scontext_len) 1379 goto out; 1380 1381 /* Check the validity of the new context. */ 1382 if (!policydb_context_isvalid(pol, ctx)) 1383 goto out; 1384 rc = 0; 1385 out: 1386 if (rc) 1387 context_destroy(ctx); 1388 return rc; 1389 } 1390 1391 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1392 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1393 int force) 1394 { 1395 char *scontext2, *str = NULL; 1396 struct context context; 1397 int rc = 0; 1398 1399 /* An empty security context is never valid. */ 1400 if (!scontext_len) 1401 return -EINVAL; 1402 1403 if (!ss_initialized) { 1404 int i; 1405 1406 for (i = 1; i < SECINITSID_NUM; i++) { 1407 if (!strcmp(initial_sid_to_string[i], scontext)) { 1408 *sid = i; 1409 return 0; 1410 } 1411 } 1412 *sid = SECINITSID_KERNEL; 1413 return 0; 1414 } 1415 *sid = SECSID_NULL; 1416 1417 /* Copy the string so that we can modify the copy as we parse it. */ 1418 scontext2 = kmalloc(scontext_len + 1, gfp_flags); 1419 if (!scontext2) 1420 return -ENOMEM; 1421 memcpy(scontext2, scontext, scontext_len); 1422 scontext2[scontext_len] = 0; 1423 1424 if (force) { 1425 /* Save another copy for storing in uninterpreted form */ 1426 rc = -ENOMEM; 1427 str = kstrdup(scontext2, gfp_flags); 1428 if (!str) 1429 goto out; 1430 } 1431 1432 read_lock(&policy_rwlock); 1433 rc = string_to_context_struct(&policydb, &sidtab, scontext2, 1434 scontext_len, &context, def_sid); 1435 if (rc == -EINVAL && force) { 1436 context.str = str; 1437 context.len = scontext_len; 1438 str = NULL; 1439 } else if (rc) 1440 goto out_unlock; 1441 rc = sidtab_context_to_sid(&sidtab, &context, sid); 1442 context_destroy(&context); 1443 out_unlock: 1444 read_unlock(&policy_rwlock); 1445 out: 1446 kfree(scontext2); 1447 kfree(str); 1448 return rc; 1449 } 1450 1451 /** 1452 * security_context_to_sid - Obtain a SID for a given security context. 1453 * @scontext: security context 1454 * @scontext_len: length in bytes 1455 * @sid: security identifier, SID 1456 * @gfp: context for the allocation 1457 * 1458 * Obtains a SID associated with the security context that 1459 * has the string representation specified by @scontext. 1460 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1461 * memory is available, or 0 on success. 1462 */ 1463 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1464 gfp_t gfp) 1465 { 1466 return security_context_to_sid_core(scontext, scontext_len, 1467 sid, SECSID_NULL, gfp, 0); 1468 } 1469 1470 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1471 { 1472 return security_context_to_sid(scontext, strlen(scontext), sid, gfp); 1473 } 1474 1475 /** 1476 * security_context_to_sid_default - Obtain a SID for a given security context, 1477 * falling back to specified default if needed. 1478 * 1479 * @scontext: security context 1480 * @scontext_len: length in bytes 1481 * @sid: security identifier, SID 1482 * @def_sid: default SID to assign on error 1483 * 1484 * Obtains a SID associated with the security context that 1485 * has the string representation specified by @scontext. 1486 * The default SID is passed to the MLS layer to be used to allow 1487 * kernel labeling of the MLS field if the MLS field is not present 1488 * (for upgrading to MLS without full relabel). 1489 * Implicitly forces adding of the context even if it cannot be mapped yet. 1490 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1491 * memory is available, or 0 on success. 1492 */ 1493 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1494 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1495 { 1496 return security_context_to_sid_core(scontext, scontext_len, 1497 sid, def_sid, gfp_flags, 1); 1498 } 1499 1500 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1501 u32 *sid) 1502 { 1503 return security_context_to_sid_core(scontext, scontext_len, 1504 sid, SECSID_NULL, GFP_KERNEL, 1); 1505 } 1506 1507 static int compute_sid_handle_invalid_context( 1508 struct context *scontext, 1509 struct context *tcontext, 1510 u16 tclass, 1511 struct context *newcontext) 1512 { 1513 char *s = NULL, *t = NULL, *n = NULL; 1514 u32 slen, tlen, nlen; 1515 1516 if (context_struct_to_string(scontext, &s, &slen)) 1517 goto out; 1518 if (context_struct_to_string(tcontext, &t, &tlen)) 1519 goto out; 1520 if (context_struct_to_string(newcontext, &n, &nlen)) 1521 goto out; 1522 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 1523 "op=security_compute_sid invalid_context=%s" 1524 " scontext=%s" 1525 " tcontext=%s" 1526 " tclass=%s", 1527 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 1528 out: 1529 kfree(s); 1530 kfree(t); 1531 kfree(n); 1532 if (!selinux_enforcing) 1533 return 0; 1534 return -EACCES; 1535 } 1536 1537 static void filename_compute_type(struct policydb *p, struct context *newcontext, 1538 u32 stype, u32 ttype, u16 tclass, 1539 const char *objname) 1540 { 1541 struct filename_trans ft; 1542 struct filename_trans_datum *otype; 1543 1544 /* 1545 * Most filename trans rules are going to live in specific directories 1546 * like /dev or /var/run. This bitmap will quickly skip rule searches 1547 * if the ttype does not contain any rules. 1548 */ 1549 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype)) 1550 return; 1551 1552 ft.stype = stype; 1553 ft.ttype = ttype; 1554 ft.tclass = tclass; 1555 ft.name = objname; 1556 1557 otype = hashtab_search(p->filename_trans, &ft); 1558 if (otype) 1559 newcontext->type = otype->otype; 1560 } 1561 1562 static int security_compute_sid(u32 ssid, 1563 u32 tsid, 1564 u16 orig_tclass, 1565 u32 specified, 1566 const char *objname, 1567 u32 *out_sid, 1568 bool kern) 1569 { 1570 struct class_datum *cladatum = NULL; 1571 struct context *scontext = NULL, *tcontext = NULL, newcontext; 1572 struct role_trans *roletr = NULL; 1573 struct avtab_key avkey; 1574 struct avtab_datum *avdatum; 1575 struct avtab_node *node; 1576 u16 tclass; 1577 int rc = 0; 1578 bool sock; 1579 1580 if (!ss_initialized) { 1581 switch (orig_tclass) { 1582 case SECCLASS_PROCESS: /* kernel value */ 1583 *out_sid = ssid; 1584 break; 1585 default: 1586 *out_sid = tsid; 1587 break; 1588 } 1589 goto out; 1590 } 1591 1592 context_init(&newcontext); 1593 1594 read_lock(&policy_rwlock); 1595 1596 if (kern) { 1597 tclass = unmap_class(orig_tclass); 1598 sock = security_is_socket_class(orig_tclass); 1599 } else { 1600 tclass = orig_tclass; 1601 sock = security_is_socket_class(map_class(tclass)); 1602 } 1603 1604 scontext = sidtab_search(&sidtab, ssid); 1605 if (!scontext) { 1606 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1607 __func__, ssid); 1608 rc = -EINVAL; 1609 goto out_unlock; 1610 } 1611 tcontext = sidtab_search(&sidtab, tsid); 1612 if (!tcontext) { 1613 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1614 __func__, tsid); 1615 rc = -EINVAL; 1616 goto out_unlock; 1617 } 1618 1619 if (tclass && tclass <= policydb.p_classes.nprim) 1620 cladatum = policydb.class_val_to_struct[tclass - 1]; 1621 1622 /* Set the user identity. */ 1623 switch (specified) { 1624 case AVTAB_TRANSITION: 1625 case AVTAB_CHANGE: 1626 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1627 newcontext.user = tcontext->user; 1628 } else { 1629 /* notice this gets both DEFAULT_SOURCE and unset */ 1630 /* Use the process user identity. */ 1631 newcontext.user = scontext->user; 1632 } 1633 break; 1634 case AVTAB_MEMBER: 1635 /* Use the related object owner. */ 1636 newcontext.user = tcontext->user; 1637 break; 1638 } 1639 1640 /* Set the role to default values. */ 1641 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1642 newcontext.role = scontext->role; 1643 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1644 newcontext.role = tcontext->role; 1645 } else { 1646 if ((tclass == policydb.process_class) || (sock == true)) 1647 newcontext.role = scontext->role; 1648 else 1649 newcontext.role = OBJECT_R_VAL; 1650 } 1651 1652 /* Set the type to default values. */ 1653 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1654 newcontext.type = scontext->type; 1655 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1656 newcontext.type = tcontext->type; 1657 } else { 1658 if ((tclass == policydb.process_class) || (sock == true)) { 1659 /* Use the type of process. */ 1660 newcontext.type = scontext->type; 1661 } else { 1662 /* Use the type of the related object. */ 1663 newcontext.type = tcontext->type; 1664 } 1665 } 1666 1667 /* Look for a type transition/member/change rule. */ 1668 avkey.source_type = scontext->type; 1669 avkey.target_type = tcontext->type; 1670 avkey.target_class = tclass; 1671 avkey.specified = specified; 1672 avdatum = avtab_search(&policydb.te_avtab, &avkey); 1673 1674 /* If no permanent rule, also check for enabled conditional rules */ 1675 if (!avdatum) { 1676 node = avtab_search_node(&policydb.te_cond_avtab, &avkey); 1677 for (; node; node = avtab_search_node_next(node, specified)) { 1678 if (node->key.specified & AVTAB_ENABLED) { 1679 avdatum = &node->datum; 1680 break; 1681 } 1682 } 1683 } 1684 1685 if (avdatum) { 1686 /* Use the type from the type transition/member/change rule. */ 1687 newcontext.type = avdatum->u.data; 1688 } 1689 1690 /* if we have a objname this is a file trans check so check those rules */ 1691 if (objname) 1692 filename_compute_type(&policydb, &newcontext, scontext->type, 1693 tcontext->type, tclass, objname); 1694 1695 /* Check for class-specific changes. */ 1696 if (specified & AVTAB_TRANSITION) { 1697 /* Look for a role transition rule. */ 1698 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) { 1699 if ((roletr->role == scontext->role) && 1700 (roletr->type == tcontext->type) && 1701 (roletr->tclass == tclass)) { 1702 /* Use the role transition rule. */ 1703 newcontext.role = roletr->new_role; 1704 break; 1705 } 1706 } 1707 } 1708 1709 /* Set the MLS attributes. 1710 This is done last because it may allocate memory. */ 1711 rc = mls_compute_sid(scontext, tcontext, tclass, specified, 1712 &newcontext, sock); 1713 if (rc) 1714 goto out_unlock; 1715 1716 /* Check the validity of the context. */ 1717 if (!policydb_context_isvalid(&policydb, &newcontext)) { 1718 rc = compute_sid_handle_invalid_context(scontext, 1719 tcontext, 1720 tclass, 1721 &newcontext); 1722 if (rc) 1723 goto out_unlock; 1724 } 1725 /* Obtain the sid for the context. */ 1726 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); 1727 out_unlock: 1728 read_unlock(&policy_rwlock); 1729 context_destroy(&newcontext); 1730 out: 1731 return rc; 1732 } 1733 1734 /** 1735 * security_transition_sid - Compute the SID for a new subject/object. 1736 * @ssid: source security identifier 1737 * @tsid: target security identifier 1738 * @tclass: target security class 1739 * @out_sid: security identifier for new subject/object 1740 * 1741 * Compute a SID to use for labeling a new subject or object in the 1742 * class @tclass based on a SID pair (@ssid, @tsid). 1743 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1744 * if insufficient memory is available, or %0 if the new SID was 1745 * computed successfully. 1746 */ 1747 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1748 const struct qstr *qstr, u32 *out_sid) 1749 { 1750 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1751 qstr ? qstr->name : NULL, out_sid, true); 1752 } 1753 1754 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1755 const char *objname, u32 *out_sid) 1756 { 1757 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1758 objname, out_sid, false); 1759 } 1760 1761 /** 1762 * security_member_sid - Compute the SID for member selection. 1763 * @ssid: source security identifier 1764 * @tsid: target security identifier 1765 * @tclass: target security class 1766 * @out_sid: security identifier for selected member 1767 * 1768 * Compute a SID to use when selecting a member of a polyinstantiated 1769 * object of class @tclass based on a SID pair (@ssid, @tsid). 1770 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1771 * if insufficient memory is available, or %0 if the SID was 1772 * computed successfully. 1773 */ 1774 int security_member_sid(u32 ssid, 1775 u32 tsid, 1776 u16 tclass, 1777 u32 *out_sid) 1778 { 1779 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL, 1780 out_sid, false); 1781 } 1782 1783 /** 1784 * security_change_sid - Compute the SID for object relabeling. 1785 * @ssid: source security identifier 1786 * @tsid: target security identifier 1787 * @tclass: target security class 1788 * @out_sid: security identifier for selected member 1789 * 1790 * Compute a SID to use for relabeling an object of class @tclass 1791 * based on a SID pair (@ssid, @tsid). 1792 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1793 * if insufficient memory is available, or %0 if the SID was 1794 * computed successfully. 1795 */ 1796 int security_change_sid(u32 ssid, 1797 u32 tsid, 1798 u16 tclass, 1799 u32 *out_sid) 1800 { 1801 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1802 out_sid, false); 1803 } 1804 1805 /* Clone the SID into the new SID table. */ 1806 static int clone_sid(u32 sid, 1807 struct context *context, 1808 void *arg) 1809 { 1810 struct sidtab *s = arg; 1811 1812 if (sid > SECINITSID_NUM) 1813 return sidtab_insert(s, sid, context); 1814 else 1815 return 0; 1816 } 1817 1818 static inline int convert_context_handle_invalid_context(struct context *context) 1819 { 1820 char *s; 1821 u32 len; 1822 1823 if (selinux_enforcing) 1824 return -EINVAL; 1825 1826 if (!context_struct_to_string(context, &s, &len)) { 1827 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s); 1828 kfree(s); 1829 } 1830 return 0; 1831 } 1832 1833 struct convert_context_args { 1834 struct policydb *oldp; 1835 struct policydb *newp; 1836 }; 1837 1838 /* 1839 * Convert the values in the security context 1840 * structure `c' from the values specified 1841 * in the policy `p->oldp' to the values specified 1842 * in the policy `p->newp'. Verify that the 1843 * context is valid under the new policy. 1844 */ 1845 static int convert_context(u32 key, 1846 struct context *c, 1847 void *p) 1848 { 1849 struct convert_context_args *args; 1850 struct context oldc; 1851 struct ocontext *oc; 1852 struct mls_range *range; 1853 struct role_datum *role; 1854 struct type_datum *typdatum; 1855 struct user_datum *usrdatum; 1856 char *s; 1857 u32 len; 1858 int rc = 0; 1859 1860 if (key <= SECINITSID_NUM) 1861 goto out; 1862 1863 args = p; 1864 1865 if (c->str) { 1866 struct context ctx; 1867 1868 rc = -ENOMEM; 1869 s = kstrdup(c->str, GFP_KERNEL); 1870 if (!s) 1871 goto out; 1872 1873 rc = string_to_context_struct(args->newp, NULL, s, 1874 c->len, &ctx, SECSID_NULL); 1875 kfree(s); 1876 if (!rc) { 1877 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n", 1878 c->str); 1879 /* Replace string with mapped representation. */ 1880 kfree(c->str); 1881 memcpy(c, &ctx, sizeof(*c)); 1882 goto out; 1883 } else if (rc == -EINVAL) { 1884 /* Retain string representation for later mapping. */ 1885 rc = 0; 1886 goto out; 1887 } else { 1888 /* Other error condition, e.g. ENOMEM. */ 1889 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n", 1890 c->str, -rc); 1891 goto out; 1892 } 1893 } 1894 1895 rc = context_cpy(&oldc, c); 1896 if (rc) 1897 goto out; 1898 1899 /* Convert the user. */ 1900 rc = -EINVAL; 1901 usrdatum = hashtab_search(args->newp->p_users.table, 1902 sym_name(args->oldp, SYM_USERS, c->user - 1)); 1903 if (!usrdatum) 1904 goto bad; 1905 c->user = usrdatum->value; 1906 1907 /* Convert the role. */ 1908 rc = -EINVAL; 1909 role = hashtab_search(args->newp->p_roles.table, 1910 sym_name(args->oldp, SYM_ROLES, c->role - 1)); 1911 if (!role) 1912 goto bad; 1913 c->role = role->value; 1914 1915 /* Convert the type. */ 1916 rc = -EINVAL; 1917 typdatum = hashtab_search(args->newp->p_types.table, 1918 sym_name(args->oldp, SYM_TYPES, c->type - 1)); 1919 if (!typdatum) 1920 goto bad; 1921 c->type = typdatum->value; 1922 1923 /* Convert the MLS fields if dealing with MLS policies */ 1924 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 1925 rc = mls_convert_context(args->oldp, args->newp, c); 1926 if (rc) 1927 goto bad; 1928 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) { 1929 /* 1930 * Switching between MLS and non-MLS policy: 1931 * free any storage used by the MLS fields in the 1932 * context for all existing entries in the sidtab. 1933 */ 1934 mls_context_destroy(c); 1935 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 1936 /* 1937 * Switching between non-MLS and MLS policy: 1938 * ensure that the MLS fields of the context for all 1939 * existing entries in the sidtab are filled in with a 1940 * suitable default value, likely taken from one of the 1941 * initial SIDs. 1942 */ 1943 oc = args->newp->ocontexts[OCON_ISID]; 1944 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 1945 oc = oc->next; 1946 rc = -EINVAL; 1947 if (!oc) { 1948 printk(KERN_ERR "SELinux: unable to look up" 1949 " the initial SIDs list\n"); 1950 goto bad; 1951 } 1952 range = &oc->context[0].range; 1953 rc = mls_range_set(c, range); 1954 if (rc) 1955 goto bad; 1956 } 1957 1958 /* Check the validity of the new context. */ 1959 if (!policydb_context_isvalid(args->newp, c)) { 1960 rc = convert_context_handle_invalid_context(&oldc); 1961 if (rc) 1962 goto bad; 1963 } 1964 1965 context_destroy(&oldc); 1966 1967 rc = 0; 1968 out: 1969 return rc; 1970 bad: 1971 /* Map old representation to string and save it. */ 1972 rc = context_struct_to_string(&oldc, &s, &len); 1973 if (rc) 1974 return rc; 1975 context_destroy(&oldc); 1976 context_destroy(c); 1977 c->str = s; 1978 c->len = len; 1979 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n", 1980 c->str); 1981 rc = 0; 1982 goto out; 1983 } 1984 1985 static void security_load_policycaps(void) 1986 { 1987 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps, 1988 POLICYDB_CAPABILITY_NETPEER); 1989 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps, 1990 POLICYDB_CAPABILITY_OPENPERM); 1991 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps, 1992 POLICYDB_CAPABILITY_ALWAYSNETWORK); 1993 } 1994 1995 static int security_preserve_bools(struct policydb *p); 1996 1997 /** 1998 * security_load_policy - Load a security policy configuration. 1999 * @data: binary policy data 2000 * @len: length of data in bytes 2001 * 2002 * Load a new set of security policy configuration data, 2003 * validate it and convert the SID table as necessary. 2004 * This function will flush the access vector cache after 2005 * loading the new policy. 2006 */ 2007 int security_load_policy(void *data, size_t len) 2008 { 2009 struct policydb *oldpolicydb, *newpolicydb; 2010 struct sidtab oldsidtab, newsidtab; 2011 struct selinux_mapping *oldmap, *map = NULL; 2012 struct convert_context_args args; 2013 u32 seqno; 2014 u16 map_size; 2015 int rc = 0; 2016 struct policy_file file = { data, len }, *fp = &file; 2017 2018 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL); 2019 if (!oldpolicydb) { 2020 rc = -ENOMEM; 2021 goto out; 2022 } 2023 newpolicydb = oldpolicydb + 1; 2024 2025 if (!ss_initialized) { 2026 avtab_cache_init(); 2027 rc = policydb_read(&policydb, fp); 2028 if (rc) { 2029 avtab_cache_destroy(); 2030 goto out; 2031 } 2032 2033 policydb.len = len; 2034 rc = selinux_set_mapping(&policydb, secclass_map, 2035 ¤t_mapping, 2036 ¤t_mapping_size); 2037 if (rc) { 2038 policydb_destroy(&policydb); 2039 avtab_cache_destroy(); 2040 goto out; 2041 } 2042 2043 rc = policydb_load_isids(&policydb, &sidtab); 2044 if (rc) { 2045 policydb_destroy(&policydb); 2046 avtab_cache_destroy(); 2047 goto out; 2048 } 2049 2050 security_load_policycaps(); 2051 ss_initialized = 1; 2052 seqno = ++latest_granting; 2053 selinux_complete_init(); 2054 avc_ss_reset(seqno); 2055 selnl_notify_policyload(seqno); 2056 selinux_status_update_policyload(seqno); 2057 selinux_netlbl_cache_invalidate(); 2058 selinux_xfrm_notify_policyload(); 2059 goto out; 2060 } 2061 2062 #if 0 2063 sidtab_hash_eval(&sidtab, "sids"); 2064 #endif 2065 2066 rc = policydb_read(newpolicydb, fp); 2067 if (rc) 2068 goto out; 2069 2070 newpolicydb->len = len; 2071 /* If switching between different policy types, log MLS status */ 2072 if (policydb.mls_enabled && !newpolicydb->mls_enabled) 2073 printk(KERN_INFO "SELinux: Disabling MLS support...\n"); 2074 else if (!policydb.mls_enabled && newpolicydb->mls_enabled) 2075 printk(KERN_INFO "SELinux: Enabling MLS support...\n"); 2076 2077 rc = policydb_load_isids(newpolicydb, &newsidtab); 2078 if (rc) { 2079 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n"); 2080 policydb_destroy(newpolicydb); 2081 goto out; 2082 } 2083 2084 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size); 2085 if (rc) 2086 goto err; 2087 2088 rc = security_preserve_bools(newpolicydb); 2089 if (rc) { 2090 printk(KERN_ERR "SELinux: unable to preserve booleans\n"); 2091 goto err; 2092 } 2093 2094 /* Clone the SID table. */ 2095 sidtab_shutdown(&sidtab); 2096 2097 rc = sidtab_map(&sidtab, clone_sid, &newsidtab); 2098 if (rc) 2099 goto err; 2100 2101 /* 2102 * Convert the internal representations of contexts 2103 * in the new SID table. 2104 */ 2105 args.oldp = &policydb; 2106 args.newp = newpolicydb; 2107 rc = sidtab_map(&newsidtab, convert_context, &args); 2108 if (rc) { 2109 printk(KERN_ERR "SELinux: unable to convert the internal" 2110 " representation of contexts in the new SID" 2111 " table\n"); 2112 goto err; 2113 } 2114 2115 /* Save the old policydb and SID table to free later. */ 2116 memcpy(oldpolicydb, &policydb, sizeof(policydb)); 2117 sidtab_set(&oldsidtab, &sidtab); 2118 2119 /* Install the new policydb and SID table. */ 2120 write_lock_irq(&policy_rwlock); 2121 memcpy(&policydb, newpolicydb, sizeof(policydb)); 2122 sidtab_set(&sidtab, &newsidtab); 2123 security_load_policycaps(); 2124 oldmap = current_mapping; 2125 current_mapping = map; 2126 current_mapping_size = map_size; 2127 seqno = ++latest_granting; 2128 write_unlock_irq(&policy_rwlock); 2129 2130 /* Free the old policydb and SID table. */ 2131 policydb_destroy(oldpolicydb); 2132 sidtab_destroy(&oldsidtab); 2133 kfree(oldmap); 2134 2135 avc_ss_reset(seqno); 2136 selnl_notify_policyload(seqno); 2137 selinux_status_update_policyload(seqno); 2138 selinux_netlbl_cache_invalidate(); 2139 selinux_xfrm_notify_policyload(); 2140 2141 rc = 0; 2142 goto out; 2143 2144 err: 2145 kfree(map); 2146 sidtab_destroy(&newsidtab); 2147 policydb_destroy(newpolicydb); 2148 2149 out: 2150 kfree(oldpolicydb); 2151 return rc; 2152 } 2153 2154 size_t security_policydb_len(void) 2155 { 2156 size_t len; 2157 2158 read_lock(&policy_rwlock); 2159 len = policydb.len; 2160 read_unlock(&policy_rwlock); 2161 2162 return len; 2163 } 2164 2165 /** 2166 * security_port_sid - Obtain the SID for a port. 2167 * @protocol: protocol number 2168 * @port: port number 2169 * @out_sid: security identifier 2170 */ 2171 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2172 { 2173 struct ocontext *c; 2174 int rc = 0; 2175 2176 read_lock(&policy_rwlock); 2177 2178 c = policydb.ocontexts[OCON_PORT]; 2179 while (c) { 2180 if (c->u.port.protocol == protocol && 2181 c->u.port.low_port <= port && 2182 c->u.port.high_port >= port) 2183 break; 2184 c = c->next; 2185 } 2186 2187 if (c) { 2188 if (!c->sid[0]) { 2189 rc = sidtab_context_to_sid(&sidtab, 2190 &c->context[0], 2191 &c->sid[0]); 2192 if (rc) 2193 goto out; 2194 } 2195 *out_sid = c->sid[0]; 2196 } else { 2197 *out_sid = SECINITSID_PORT; 2198 } 2199 2200 out: 2201 read_unlock(&policy_rwlock); 2202 return rc; 2203 } 2204 2205 /** 2206 * security_netif_sid - Obtain the SID for a network interface. 2207 * @name: interface name 2208 * @if_sid: interface SID 2209 */ 2210 int security_netif_sid(char *name, u32 *if_sid) 2211 { 2212 int rc = 0; 2213 struct ocontext *c; 2214 2215 read_lock(&policy_rwlock); 2216 2217 c = policydb.ocontexts[OCON_NETIF]; 2218 while (c) { 2219 if (strcmp(name, c->u.name) == 0) 2220 break; 2221 c = c->next; 2222 } 2223 2224 if (c) { 2225 if (!c->sid[0] || !c->sid[1]) { 2226 rc = sidtab_context_to_sid(&sidtab, 2227 &c->context[0], 2228 &c->sid[0]); 2229 if (rc) 2230 goto out; 2231 rc = sidtab_context_to_sid(&sidtab, 2232 &c->context[1], 2233 &c->sid[1]); 2234 if (rc) 2235 goto out; 2236 } 2237 *if_sid = c->sid[0]; 2238 } else 2239 *if_sid = SECINITSID_NETIF; 2240 2241 out: 2242 read_unlock(&policy_rwlock); 2243 return rc; 2244 } 2245 2246 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2247 { 2248 int i, fail = 0; 2249 2250 for (i = 0; i < 4; i++) 2251 if (addr[i] != (input[i] & mask[i])) { 2252 fail = 1; 2253 break; 2254 } 2255 2256 return !fail; 2257 } 2258 2259 /** 2260 * security_node_sid - Obtain the SID for a node (host). 2261 * @domain: communication domain aka address family 2262 * @addrp: address 2263 * @addrlen: address length in bytes 2264 * @out_sid: security identifier 2265 */ 2266 int security_node_sid(u16 domain, 2267 void *addrp, 2268 u32 addrlen, 2269 u32 *out_sid) 2270 { 2271 int rc; 2272 struct ocontext *c; 2273 2274 read_lock(&policy_rwlock); 2275 2276 switch (domain) { 2277 case AF_INET: { 2278 u32 addr; 2279 2280 rc = -EINVAL; 2281 if (addrlen != sizeof(u32)) 2282 goto out; 2283 2284 addr = *((u32 *)addrp); 2285 2286 c = policydb.ocontexts[OCON_NODE]; 2287 while (c) { 2288 if (c->u.node.addr == (addr & c->u.node.mask)) 2289 break; 2290 c = c->next; 2291 } 2292 break; 2293 } 2294 2295 case AF_INET6: 2296 rc = -EINVAL; 2297 if (addrlen != sizeof(u64) * 2) 2298 goto out; 2299 c = policydb.ocontexts[OCON_NODE6]; 2300 while (c) { 2301 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2302 c->u.node6.mask)) 2303 break; 2304 c = c->next; 2305 } 2306 break; 2307 2308 default: 2309 rc = 0; 2310 *out_sid = SECINITSID_NODE; 2311 goto out; 2312 } 2313 2314 if (c) { 2315 if (!c->sid[0]) { 2316 rc = sidtab_context_to_sid(&sidtab, 2317 &c->context[0], 2318 &c->sid[0]); 2319 if (rc) 2320 goto out; 2321 } 2322 *out_sid = c->sid[0]; 2323 } else { 2324 *out_sid = SECINITSID_NODE; 2325 } 2326 2327 rc = 0; 2328 out: 2329 read_unlock(&policy_rwlock); 2330 return rc; 2331 } 2332 2333 #define SIDS_NEL 25 2334 2335 /** 2336 * security_get_user_sids - Obtain reachable SIDs for a user. 2337 * @fromsid: starting SID 2338 * @username: username 2339 * @sids: array of reachable SIDs for user 2340 * @nel: number of elements in @sids 2341 * 2342 * Generate the set of SIDs for legal security contexts 2343 * for a given user that can be reached by @fromsid. 2344 * Set *@sids to point to a dynamically allocated 2345 * array containing the set of SIDs. Set *@nel to the 2346 * number of elements in the array. 2347 */ 2348 2349 int security_get_user_sids(u32 fromsid, 2350 char *username, 2351 u32 **sids, 2352 u32 *nel) 2353 { 2354 struct context *fromcon, usercon; 2355 u32 *mysids = NULL, *mysids2, sid; 2356 u32 mynel = 0, maxnel = SIDS_NEL; 2357 struct user_datum *user; 2358 struct role_datum *role; 2359 struct ebitmap_node *rnode, *tnode; 2360 int rc = 0, i, j; 2361 2362 *sids = NULL; 2363 *nel = 0; 2364 2365 if (!ss_initialized) 2366 goto out; 2367 2368 read_lock(&policy_rwlock); 2369 2370 context_init(&usercon); 2371 2372 rc = -EINVAL; 2373 fromcon = sidtab_search(&sidtab, fromsid); 2374 if (!fromcon) 2375 goto out_unlock; 2376 2377 rc = -EINVAL; 2378 user = hashtab_search(policydb.p_users.table, username); 2379 if (!user) 2380 goto out_unlock; 2381 2382 usercon.user = user->value; 2383 2384 rc = -ENOMEM; 2385 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); 2386 if (!mysids) 2387 goto out_unlock; 2388 2389 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2390 role = policydb.role_val_to_struct[i]; 2391 usercon.role = i + 1; 2392 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2393 usercon.type = j + 1; 2394 2395 if (mls_setup_user_range(fromcon, user, &usercon)) 2396 continue; 2397 2398 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); 2399 if (rc) 2400 goto out_unlock; 2401 if (mynel < maxnel) { 2402 mysids[mynel++] = sid; 2403 } else { 2404 rc = -ENOMEM; 2405 maxnel += SIDS_NEL; 2406 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2407 if (!mysids2) 2408 goto out_unlock; 2409 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2410 kfree(mysids); 2411 mysids = mysids2; 2412 mysids[mynel++] = sid; 2413 } 2414 } 2415 } 2416 rc = 0; 2417 out_unlock: 2418 read_unlock(&policy_rwlock); 2419 if (rc || !mynel) { 2420 kfree(mysids); 2421 goto out; 2422 } 2423 2424 rc = -ENOMEM; 2425 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2426 if (!mysids2) { 2427 kfree(mysids); 2428 goto out; 2429 } 2430 for (i = 0, j = 0; i < mynel; i++) { 2431 struct av_decision dummy_avd; 2432 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2433 SECCLASS_PROCESS, /* kernel value */ 2434 PROCESS__TRANSITION, AVC_STRICT, 2435 &dummy_avd); 2436 if (!rc) 2437 mysids2[j++] = mysids[i]; 2438 cond_resched(); 2439 } 2440 rc = 0; 2441 kfree(mysids); 2442 *sids = mysids2; 2443 *nel = j; 2444 out: 2445 return rc; 2446 } 2447 2448 /** 2449 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2450 * @fstype: filesystem type 2451 * @path: path from root of mount 2452 * @sclass: file security class 2453 * @sid: SID for path 2454 * 2455 * Obtain a SID to use for a file in a filesystem that 2456 * cannot support xattr or use a fixed labeling behavior like 2457 * transition SIDs or task SIDs. 2458 * 2459 * The caller must acquire the policy_rwlock before calling this function. 2460 */ 2461 static inline int __security_genfs_sid(const char *fstype, 2462 char *path, 2463 u16 orig_sclass, 2464 u32 *sid) 2465 { 2466 int len; 2467 u16 sclass; 2468 struct genfs *genfs; 2469 struct ocontext *c; 2470 int rc, cmp = 0; 2471 2472 while (path[0] == '/' && path[1] == '/') 2473 path++; 2474 2475 sclass = unmap_class(orig_sclass); 2476 *sid = SECINITSID_UNLABELED; 2477 2478 for (genfs = policydb.genfs; genfs; genfs = genfs->next) { 2479 cmp = strcmp(fstype, genfs->fstype); 2480 if (cmp <= 0) 2481 break; 2482 } 2483 2484 rc = -ENOENT; 2485 if (!genfs || cmp) 2486 goto out; 2487 2488 for (c = genfs->head; c; c = c->next) { 2489 len = strlen(c->u.name); 2490 if ((!c->v.sclass || sclass == c->v.sclass) && 2491 (strncmp(c->u.name, path, len) == 0)) 2492 break; 2493 } 2494 2495 rc = -ENOENT; 2496 if (!c) 2497 goto out; 2498 2499 if (!c->sid[0]) { 2500 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); 2501 if (rc) 2502 goto out; 2503 } 2504 2505 *sid = c->sid[0]; 2506 rc = 0; 2507 out: 2508 return rc; 2509 } 2510 2511 /** 2512 * security_genfs_sid - Obtain a SID for a file in a filesystem 2513 * @fstype: filesystem type 2514 * @path: path from root of mount 2515 * @sclass: file security class 2516 * @sid: SID for path 2517 * 2518 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2519 * it afterward. 2520 */ 2521 int security_genfs_sid(const char *fstype, 2522 char *path, 2523 u16 orig_sclass, 2524 u32 *sid) 2525 { 2526 int retval; 2527 2528 read_lock(&policy_rwlock); 2529 retval = __security_genfs_sid(fstype, path, orig_sclass, sid); 2530 read_unlock(&policy_rwlock); 2531 return retval; 2532 } 2533 2534 /** 2535 * security_fs_use - Determine how to handle labeling for a filesystem. 2536 * @sb: superblock in question 2537 */ 2538 int security_fs_use(struct super_block *sb) 2539 { 2540 int rc = 0; 2541 struct ocontext *c; 2542 struct superblock_security_struct *sbsec = sb->s_security; 2543 const char *fstype = sb->s_type->name; 2544 2545 read_lock(&policy_rwlock); 2546 2547 c = policydb.ocontexts[OCON_FSUSE]; 2548 while (c) { 2549 if (strcmp(fstype, c->u.name) == 0) 2550 break; 2551 c = c->next; 2552 } 2553 2554 if (c) { 2555 sbsec->behavior = c->v.behavior; 2556 if (!c->sid[0]) { 2557 rc = sidtab_context_to_sid(&sidtab, &c->context[0], 2558 &c->sid[0]); 2559 if (rc) 2560 goto out; 2561 } 2562 sbsec->sid = c->sid[0]; 2563 } else { 2564 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR, 2565 &sbsec->sid); 2566 if (rc) { 2567 sbsec->behavior = SECURITY_FS_USE_NONE; 2568 rc = 0; 2569 } else { 2570 sbsec->behavior = SECURITY_FS_USE_GENFS; 2571 } 2572 } 2573 2574 out: 2575 read_unlock(&policy_rwlock); 2576 return rc; 2577 } 2578 2579 int security_get_bools(int *len, char ***names, int **values) 2580 { 2581 int i, rc; 2582 2583 read_lock(&policy_rwlock); 2584 *names = NULL; 2585 *values = NULL; 2586 2587 rc = 0; 2588 *len = policydb.p_bools.nprim; 2589 if (!*len) 2590 goto out; 2591 2592 rc = -ENOMEM; 2593 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2594 if (!*names) 2595 goto err; 2596 2597 rc = -ENOMEM; 2598 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2599 if (!*values) 2600 goto err; 2601 2602 for (i = 0; i < *len; i++) { 2603 (*values)[i] = policydb.bool_val_to_struct[i]->state; 2604 2605 rc = -ENOMEM; 2606 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC); 2607 if (!(*names)[i]) 2608 goto err; 2609 } 2610 rc = 0; 2611 out: 2612 read_unlock(&policy_rwlock); 2613 return rc; 2614 err: 2615 if (*names) { 2616 for (i = 0; i < *len; i++) 2617 kfree((*names)[i]); 2618 } 2619 kfree(*values); 2620 goto out; 2621 } 2622 2623 2624 int security_set_bools(int len, int *values) 2625 { 2626 int i, rc; 2627 int lenp, seqno = 0; 2628 struct cond_node *cur; 2629 2630 write_lock_irq(&policy_rwlock); 2631 2632 rc = -EFAULT; 2633 lenp = policydb.p_bools.nprim; 2634 if (len != lenp) 2635 goto out; 2636 2637 for (i = 0; i < len; i++) { 2638 if (!!values[i] != policydb.bool_val_to_struct[i]->state) { 2639 audit_log(current->audit_context, GFP_ATOMIC, 2640 AUDIT_MAC_CONFIG_CHANGE, 2641 "bool=%s val=%d old_val=%d auid=%u ses=%u", 2642 sym_name(&policydb, SYM_BOOLS, i), 2643 !!values[i], 2644 policydb.bool_val_to_struct[i]->state, 2645 from_kuid(&init_user_ns, audit_get_loginuid(current)), 2646 audit_get_sessionid(current)); 2647 } 2648 if (values[i]) 2649 policydb.bool_val_to_struct[i]->state = 1; 2650 else 2651 policydb.bool_val_to_struct[i]->state = 0; 2652 } 2653 2654 for (cur = policydb.cond_list; cur; cur = cur->next) { 2655 rc = evaluate_cond_node(&policydb, cur); 2656 if (rc) 2657 goto out; 2658 } 2659 2660 seqno = ++latest_granting; 2661 rc = 0; 2662 out: 2663 write_unlock_irq(&policy_rwlock); 2664 if (!rc) { 2665 avc_ss_reset(seqno); 2666 selnl_notify_policyload(seqno); 2667 selinux_status_update_policyload(seqno); 2668 selinux_xfrm_notify_policyload(); 2669 } 2670 return rc; 2671 } 2672 2673 int security_get_bool_value(int index) 2674 { 2675 int rc; 2676 int len; 2677 2678 read_lock(&policy_rwlock); 2679 2680 rc = -EFAULT; 2681 len = policydb.p_bools.nprim; 2682 if (index >= len) 2683 goto out; 2684 2685 rc = policydb.bool_val_to_struct[index]->state; 2686 out: 2687 read_unlock(&policy_rwlock); 2688 return rc; 2689 } 2690 2691 static int security_preserve_bools(struct policydb *p) 2692 { 2693 int rc, nbools = 0, *bvalues = NULL, i; 2694 char **bnames = NULL; 2695 struct cond_bool_datum *booldatum; 2696 struct cond_node *cur; 2697 2698 rc = security_get_bools(&nbools, &bnames, &bvalues); 2699 if (rc) 2700 goto out; 2701 for (i = 0; i < nbools; i++) { 2702 booldatum = hashtab_search(p->p_bools.table, bnames[i]); 2703 if (booldatum) 2704 booldatum->state = bvalues[i]; 2705 } 2706 for (cur = p->cond_list; cur; cur = cur->next) { 2707 rc = evaluate_cond_node(p, cur); 2708 if (rc) 2709 goto out; 2710 } 2711 2712 out: 2713 if (bnames) { 2714 for (i = 0; i < nbools; i++) 2715 kfree(bnames[i]); 2716 } 2717 kfree(bnames); 2718 kfree(bvalues); 2719 return rc; 2720 } 2721 2722 /* 2723 * security_sid_mls_copy() - computes a new sid based on the given 2724 * sid and the mls portion of mls_sid. 2725 */ 2726 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 2727 { 2728 struct context *context1; 2729 struct context *context2; 2730 struct context newcon; 2731 char *s; 2732 u32 len; 2733 int rc; 2734 2735 rc = 0; 2736 if (!ss_initialized || !policydb.mls_enabled) { 2737 *new_sid = sid; 2738 goto out; 2739 } 2740 2741 context_init(&newcon); 2742 2743 read_lock(&policy_rwlock); 2744 2745 rc = -EINVAL; 2746 context1 = sidtab_search(&sidtab, sid); 2747 if (!context1) { 2748 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2749 __func__, sid); 2750 goto out_unlock; 2751 } 2752 2753 rc = -EINVAL; 2754 context2 = sidtab_search(&sidtab, mls_sid); 2755 if (!context2) { 2756 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2757 __func__, mls_sid); 2758 goto out_unlock; 2759 } 2760 2761 newcon.user = context1->user; 2762 newcon.role = context1->role; 2763 newcon.type = context1->type; 2764 rc = mls_context_cpy(&newcon, context2); 2765 if (rc) 2766 goto out_unlock; 2767 2768 /* Check the validity of the new context. */ 2769 if (!policydb_context_isvalid(&policydb, &newcon)) { 2770 rc = convert_context_handle_invalid_context(&newcon); 2771 if (rc) { 2772 if (!context_struct_to_string(&newcon, &s, &len)) { 2773 audit_log(current->audit_context, 2774 GFP_ATOMIC, AUDIT_SELINUX_ERR, 2775 "op=security_sid_mls_copy " 2776 "invalid_context=%s", s); 2777 kfree(s); 2778 } 2779 goto out_unlock; 2780 } 2781 } 2782 2783 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid); 2784 out_unlock: 2785 read_unlock(&policy_rwlock); 2786 context_destroy(&newcon); 2787 out: 2788 return rc; 2789 } 2790 2791 /** 2792 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 2793 * @nlbl_sid: NetLabel SID 2794 * @nlbl_type: NetLabel labeling protocol type 2795 * @xfrm_sid: XFRM SID 2796 * 2797 * Description: 2798 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 2799 * resolved into a single SID it is returned via @peer_sid and the function 2800 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 2801 * returns a negative value. A table summarizing the behavior is below: 2802 * 2803 * | function return | @sid 2804 * ------------------------------+-----------------+----------------- 2805 * no peer labels | 0 | SECSID_NULL 2806 * single peer label | 0 | <peer_label> 2807 * multiple, consistent labels | 0 | <peer_label> 2808 * multiple, inconsistent labels | -<errno> | SECSID_NULL 2809 * 2810 */ 2811 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 2812 u32 xfrm_sid, 2813 u32 *peer_sid) 2814 { 2815 int rc; 2816 struct context *nlbl_ctx; 2817 struct context *xfrm_ctx; 2818 2819 *peer_sid = SECSID_NULL; 2820 2821 /* handle the common (which also happens to be the set of easy) cases 2822 * right away, these two if statements catch everything involving a 2823 * single or absent peer SID/label */ 2824 if (xfrm_sid == SECSID_NULL) { 2825 *peer_sid = nlbl_sid; 2826 return 0; 2827 } 2828 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 2829 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 2830 * is present */ 2831 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 2832 *peer_sid = xfrm_sid; 2833 return 0; 2834 } 2835 2836 /* we don't need to check ss_initialized here since the only way both 2837 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 2838 * security server was initialized and ss_initialized was true */ 2839 if (!policydb.mls_enabled) 2840 return 0; 2841 2842 read_lock(&policy_rwlock); 2843 2844 rc = -EINVAL; 2845 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid); 2846 if (!nlbl_ctx) { 2847 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2848 __func__, nlbl_sid); 2849 goto out; 2850 } 2851 rc = -EINVAL; 2852 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid); 2853 if (!xfrm_ctx) { 2854 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2855 __func__, xfrm_sid); 2856 goto out; 2857 } 2858 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 2859 if (rc) 2860 goto out; 2861 2862 /* at present NetLabel SIDs/labels really only carry MLS 2863 * information so if the MLS portion of the NetLabel SID 2864 * matches the MLS portion of the labeled XFRM SID/label 2865 * then pass along the XFRM SID as it is the most 2866 * expressive */ 2867 *peer_sid = xfrm_sid; 2868 out: 2869 read_unlock(&policy_rwlock); 2870 return rc; 2871 } 2872 2873 static int get_classes_callback(void *k, void *d, void *args) 2874 { 2875 struct class_datum *datum = d; 2876 char *name = k, **classes = args; 2877 int value = datum->value - 1; 2878 2879 classes[value] = kstrdup(name, GFP_ATOMIC); 2880 if (!classes[value]) 2881 return -ENOMEM; 2882 2883 return 0; 2884 } 2885 2886 int security_get_classes(char ***classes, int *nclasses) 2887 { 2888 int rc; 2889 2890 read_lock(&policy_rwlock); 2891 2892 rc = -ENOMEM; 2893 *nclasses = policydb.p_classes.nprim; 2894 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 2895 if (!*classes) 2896 goto out; 2897 2898 rc = hashtab_map(policydb.p_classes.table, get_classes_callback, 2899 *classes); 2900 if (rc) { 2901 int i; 2902 for (i = 0; i < *nclasses; i++) 2903 kfree((*classes)[i]); 2904 kfree(*classes); 2905 } 2906 2907 out: 2908 read_unlock(&policy_rwlock); 2909 return rc; 2910 } 2911 2912 static int get_permissions_callback(void *k, void *d, void *args) 2913 { 2914 struct perm_datum *datum = d; 2915 char *name = k, **perms = args; 2916 int value = datum->value - 1; 2917 2918 perms[value] = kstrdup(name, GFP_ATOMIC); 2919 if (!perms[value]) 2920 return -ENOMEM; 2921 2922 return 0; 2923 } 2924 2925 int security_get_permissions(char *class, char ***perms, int *nperms) 2926 { 2927 int rc, i; 2928 struct class_datum *match; 2929 2930 read_lock(&policy_rwlock); 2931 2932 rc = -EINVAL; 2933 match = hashtab_search(policydb.p_classes.table, class); 2934 if (!match) { 2935 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n", 2936 __func__, class); 2937 goto out; 2938 } 2939 2940 rc = -ENOMEM; 2941 *nperms = match->permissions.nprim; 2942 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 2943 if (!*perms) 2944 goto out; 2945 2946 if (match->comdatum) { 2947 rc = hashtab_map(match->comdatum->permissions.table, 2948 get_permissions_callback, *perms); 2949 if (rc) 2950 goto err; 2951 } 2952 2953 rc = hashtab_map(match->permissions.table, get_permissions_callback, 2954 *perms); 2955 if (rc) 2956 goto err; 2957 2958 out: 2959 read_unlock(&policy_rwlock); 2960 return rc; 2961 2962 err: 2963 read_unlock(&policy_rwlock); 2964 for (i = 0; i < *nperms; i++) 2965 kfree((*perms)[i]); 2966 kfree(*perms); 2967 return rc; 2968 } 2969 2970 int security_get_reject_unknown(void) 2971 { 2972 return policydb.reject_unknown; 2973 } 2974 2975 int security_get_allow_unknown(void) 2976 { 2977 return policydb.allow_unknown; 2978 } 2979 2980 /** 2981 * security_policycap_supported - Check for a specific policy capability 2982 * @req_cap: capability 2983 * 2984 * Description: 2985 * This function queries the currently loaded policy to see if it supports the 2986 * capability specified by @req_cap. Returns true (1) if the capability is 2987 * supported, false (0) if it isn't supported. 2988 * 2989 */ 2990 int security_policycap_supported(unsigned int req_cap) 2991 { 2992 int rc; 2993 2994 read_lock(&policy_rwlock); 2995 rc = ebitmap_get_bit(&policydb.policycaps, req_cap); 2996 read_unlock(&policy_rwlock); 2997 2998 return rc; 2999 } 3000 3001 struct selinux_audit_rule { 3002 u32 au_seqno; 3003 struct context au_ctxt; 3004 }; 3005 3006 void selinux_audit_rule_free(void *vrule) 3007 { 3008 struct selinux_audit_rule *rule = vrule; 3009 3010 if (rule) { 3011 context_destroy(&rule->au_ctxt); 3012 kfree(rule); 3013 } 3014 } 3015 3016 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3017 { 3018 struct selinux_audit_rule *tmprule; 3019 struct role_datum *roledatum; 3020 struct type_datum *typedatum; 3021 struct user_datum *userdatum; 3022 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3023 int rc = 0; 3024 3025 *rule = NULL; 3026 3027 if (!ss_initialized) 3028 return -EOPNOTSUPP; 3029 3030 switch (field) { 3031 case AUDIT_SUBJ_USER: 3032 case AUDIT_SUBJ_ROLE: 3033 case AUDIT_SUBJ_TYPE: 3034 case AUDIT_OBJ_USER: 3035 case AUDIT_OBJ_ROLE: 3036 case AUDIT_OBJ_TYPE: 3037 /* only 'equals' and 'not equals' fit user, role, and type */ 3038 if (op != Audit_equal && op != Audit_not_equal) 3039 return -EINVAL; 3040 break; 3041 case AUDIT_SUBJ_SEN: 3042 case AUDIT_SUBJ_CLR: 3043 case AUDIT_OBJ_LEV_LOW: 3044 case AUDIT_OBJ_LEV_HIGH: 3045 /* we do not allow a range, indicated by the presence of '-' */ 3046 if (strchr(rulestr, '-')) 3047 return -EINVAL; 3048 break; 3049 default: 3050 /* only the above fields are valid */ 3051 return -EINVAL; 3052 } 3053 3054 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3055 if (!tmprule) 3056 return -ENOMEM; 3057 3058 context_init(&tmprule->au_ctxt); 3059 3060 read_lock(&policy_rwlock); 3061 3062 tmprule->au_seqno = latest_granting; 3063 3064 switch (field) { 3065 case AUDIT_SUBJ_USER: 3066 case AUDIT_OBJ_USER: 3067 rc = -EINVAL; 3068 userdatum = hashtab_search(policydb.p_users.table, rulestr); 3069 if (!userdatum) 3070 goto out; 3071 tmprule->au_ctxt.user = userdatum->value; 3072 break; 3073 case AUDIT_SUBJ_ROLE: 3074 case AUDIT_OBJ_ROLE: 3075 rc = -EINVAL; 3076 roledatum = hashtab_search(policydb.p_roles.table, rulestr); 3077 if (!roledatum) 3078 goto out; 3079 tmprule->au_ctxt.role = roledatum->value; 3080 break; 3081 case AUDIT_SUBJ_TYPE: 3082 case AUDIT_OBJ_TYPE: 3083 rc = -EINVAL; 3084 typedatum = hashtab_search(policydb.p_types.table, rulestr); 3085 if (!typedatum) 3086 goto out; 3087 tmprule->au_ctxt.type = typedatum->value; 3088 break; 3089 case AUDIT_SUBJ_SEN: 3090 case AUDIT_SUBJ_CLR: 3091 case AUDIT_OBJ_LEV_LOW: 3092 case AUDIT_OBJ_LEV_HIGH: 3093 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC); 3094 if (rc) 3095 goto out; 3096 break; 3097 } 3098 rc = 0; 3099 out: 3100 read_unlock(&policy_rwlock); 3101 3102 if (rc) { 3103 selinux_audit_rule_free(tmprule); 3104 tmprule = NULL; 3105 } 3106 3107 *rule = tmprule; 3108 3109 return rc; 3110 } 3111 3112 /* Check to see if the rule contains any selinux fields */ 3113 int selinux_audit_rule_known(struct audit_krule *rule) 3114 { 3115 int i; 3116 3117 for (i = 0; i < rule->field_count; i++) { 3118 struct audit_field *f = &rule->fields[i]; 3119 switch (f->type) { 3120 case AUDIT_SUBJ_USER: 3121 case AUDIT_SUBJ_ROLE: 3122 case AUDIT_SUBJ_TYPE: 3123 case AUDIT_SUBJ_SEN: 3124 case AUDIT_SUBJ_CLR: 3125 case AUDIT_OBJ_USER: 3126 case AUDIT_OBJ_ROLE: 3127 case AUDIT_OBJ_TYPE: 3128 case AUDIT_OBJ_LEV_LOW: 3129 case AUDIT_OBJ_LEV_HIGH: 3130 return 1; 3131 } 3132 } 3133 3134 return 0; 3135 } 3136 3137 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, 3138 struct audit_context *actx) 3139 { 3140 struct context *ctxt; 3141 struct mls_level *level; 3142 struct selinux_audit_rule *rule = vrule; 3143 int match = 0; 3144 3145 if (unlikely(!rule)) { 3146 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3147 return -ENOENT; 3148 } 3149 3150 read_lock(&policy_rwlock); 3151 3152 if (rule->au_seqno < latest_granting) { 3153 match = -ESTALE; 3154 goto out; 3155 } 3156 3157 ctxt = sidtab_search(&sidtab, sid); 3158 if (unlikely(!ctxt)) { 3159 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3160 sid); 3161 match = -ENOENT; 3162 goto out; 3163 } 3164 3165 /* a field/op pair that is not caught here will simply fall through 3166 without a match */ 3167 switch (field) { 3168 case AUDIT_SUBJ_USER: 3169 case AUDIT_OBJ_USER: 3170 switch (op) { 3171 case Audit_equal: 3172 match = (ctxt->user == rule->au_ctxt.user); 3173 break; 3174 case Audit_not_equal: 3175 match = (ctxt->user != rule->au_ctxt.user); 3176 break; 3177 } 3178 break; 3179 case AUDIT_SUBJ_ROLE: 3180 case AUDIT_OBJ_ROLE: 3181 switch (op) { 3182 case Audit_equal: 3183 match = (ctxt->role == rule->au_ctxt.role); 3184 break; 3185 case Audit_not_equal: 3186 match = (ctxt->role != rule->au_ctxt.role); 3187 break; 3188 } 3189 break; 3190 case AUDIT_SUBJ_TYPE: 3191 case AUDIT_OBJ_TYPE: 3192 switch (op) { 3193 case Audit_equal: 3194 match = (ctxt->type == rule->au_ctxt.type); 3195 break; 3196 case Audit_not_equal: 3197 match = (ctxt->type != rule->au_ctxt.type); 3198 break; 3199 } 3200 break; 3201 case AUDIT_SUBJ_SEN: 3202 case AUDIT_SUBJ_CLR: 3203 case AUDIT_OBJ_LEV_LOW: 3204 case AUDIT_OBJ_LEV_HIGH: 3205 level = ((field == AUDIT_SUBJ_SEN || 3206 field == AUDIT_OBJ_LEV_LOW) ? 3207 &ctxt->range.level[0] : &ctxt->range.level[1]); 3208 switch (op) { 3209 case Audit_equal: 3210 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3211 level); 3212 break; 3213 case Audit_not_equal: 3214 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3215 level); 3216 break; 3217 case Audit_lt: 3218 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3219 level) && 3220 !mls_level_eq(&rule->au_ctxt.range.level[0], 3221 level)); 3222 break; 3223 case Audit_le: 3224 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3225 level); 3226 break; 3227 case Audit_gt: 3228 match = (mls_level_dom(level, 3229 &rule->au_ctxt.range.level[0]) && 3230 !mls_level_eq(level, 3231 &rule->au_ctxt.range.level[0])); 3232 break; 3233 case Audit_ge: 3234 match = mls_level_dom(level, 3235 &rule->au_ctxt.range.level[0]); 3236 break; 3237 } 3238 } 3239 3240 out: 3241 read_unlock(&policy_rwlock); 3242 return match; 3243 } 3244 3245 static int (*aurule_callback)(void) = audit_update_lsm_rules; 3246 3247 static int aurule_avc_callback(u32 event) 3248 { 3249 int err = 0; 3250 3251 if (event == AVC_CALLBACK_RESET && aurule_callback) 3252 err = aurule_callback(); 3253 return err; 3254 } 3255 3256 static int __init aurule_init(void) 3257 { 3258 int err; 3259 3260 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3261 if (err) 3262 panic("avc_add_callback() failed, error %d\n", err); 3263 3264 return err; 3265 } 3266 __initcall(aurule_init); 3267 3268 #ifdef CONFIG_NETLABEL 3269 /** 3270 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3271 * @secattr: the NetLabel packet security attributes 3272 * @sid: the SELinux SID 3273 * 3274 * Description: 3275 * Attempt to cache the context in @ctx, which was derived from the packet in 3276 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3277 * already been initialized. 3278 * 3279 */ 3280 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3281 u32 sid) 3282 { 3283 u32 *sid_cache; 3284 3285 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3286 if (sid_cache == NULL) 3287 return; 3288 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3289 if (secattr->cache == NULL) { 3290 kfree(sid_cache); 3291 return; 3292 } 3293 3294 *sid_cache = sid; 3295 secattr->cache->free = kfree; 3296 secattr->cache->data = sid_cache; 3297 secattr->flags |= NETLBL_SECATTR_CACHE; 3298 } 3299 3300 /** 3301 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3302 * @secattr: the NetLabel packet security attributes 3303 * @sid: the SELinux SID 3304 * 3305 * Description: 3306 * Convert the given NetLabel security attributes in @secattr into a 3307 * SELinux SID. If the @secattr field does not contain a full SELinux 3308 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3309 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3310 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3311 * conversion for future lookups. Returns zero on success, negative values on 3312 * failure. 3313 * 3314 */ 3315 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3316 u32 *sid) 3317 { 3318 int rc; 3319 struct context *ctx; 3320 struct context ctx_new; 3321 3322 if (!ss_initialized) { 3323 *sid = SECSID_NULL; 3324 return 0; 3325 } 3326 3327 read_lock(&policy_rwlock); 3328 3329 if (secattr->flags & NETLBL_SECATTR_CACHE) 3330 *sid = *(u32 *)secattr->cache->data; 3331 else if (secattr->flags & NETLBL_SECATTR_SECID) 3332 *sid = secattr->attr.secid; 3333 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3334 rc = -EIDRM; 3335 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG); 3336 if (ctx == NULL) 3337 goto out; 3338 3339 context_init(&ctx_new); 3340 ctx_new.user = ctx->user; 3341 ctx_new.role = ctx->role; 3342 ctx_new.type = ctx->type; 3343 mls_import_netlbl_lvl(&ctx_new, secattr); 3344 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3345 rc = mls_import_netlbl_cat(&ctx_new, secattr); 3346 if (rc) 3347 goto out; 3348 } 3349 rc = -EIDRM; 3350 if (!mls_context_isvalid(&policydb, &ctx_new)) 3351 goto out_free; 3352 3353 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); 3354 if (rc) 3355 goto out_free; 3356 3357 security_netlbl_cache_add(secattr, *sid); 3358 3359 ebitmap_destroy(&ctx_new.range.level[0].cat); 3360 } else 3361 *sid = SECSID_NULL; 3362 3363 read_unlock(&policy_rwlock); 3364 return 0; 3365 out_free: 3366 ebitmap_destroy(&ctx_new.range.level[0].cat); 3367 out: 3368 read_unlock(&policy_rwlock); 3369 return rc; 3370 } 3371 3372 /** 3373 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3374 * @sid: the SELinux SID 3375 * @secattr: the NetLabel packet security attributes 3376 * 3377 * Description: 3378 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3379 * Returns zero on success, negative values on failure. 3380 * 3381 */ 3382 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3383 { 3384 int rc; 3385 struct context *ctx; 3386 3387 if (!ss_initialized) 3388 return 0; 3389 3390 read_lock(&policy_rwlock); 3391 3392 rc = -ENOENT; 3393 ctx = sidtab_search(&sidtab, sid); 3394 if (ctx == NULL) 3395 goto out; 3396 3397 rc = -ENOMEM; 3398 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1), 3399 GFP_ATOMIC); 3400 if (secattr->domain == NULL) 3401 goto out; 3402 3403 secattr->attr.secid = sid; 3404 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3405 mls_export_netlbl_lvl(ctx, secattr); 3406 rc = mls_export_netlbl_cat(ctx, secattr); 3407 out: 3408 read_unlock(&policy_rwlock); 3409 return rc; 3410 } 3411 #endif /* CONFIG_NETLABEL */ 3412 3413 /** 3414 * security_read_policy - read the policy. 3415 * @data: binary policy data 3416 * @len: length of data in bytes 3417 * 3418 */ 3419 int security_read_policy(void **data, size_t *len) 3420 { 3421 int rc; 3422 struct policy_file fp; 3423 3424 if (!ss_initialized) 3425 return -EINVAL; 3426 3427 *len = security_policydb_len(); 3428 3429 *data = vmalloc_user(*len); 3430 if (!*data) 3431 return -ENOMEM; 3432 3433 fp.data = *data; 3434 fp.len = *len; 3435 3436 read_lock(&policy_rwlock); 3437 rc = policydb_write(&policydb, &fp); 3438 read_unlock(&policy_rwlock); 3439 3440 if (rc) 3441 return rc; 3442 3443 *len = (unsigned long)fp.data - (unsigned long)*data; 3444 return 0; 3445 3446 } 3447