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_extsockclass; 76 int selinux_policycap_alwaysnetwork; 77 int selinux_policycap_cgroupseclabel; 78 79 static DEFINE_RWLOCK(policy_rwlock); 80 81 static struct sidtab sidtab; 82 struct policydb policydb; 83 int ss_initialized; 84 85 /* 86 * The largest sequence number that has been used when 87 * providing an access decision to the access vector cache. 88 * The sequence number only changes when a policy change 89 * occurs. 90 */ 91 static u32 latest_granting; 92 93 /* Forward declaration. */ 94 static int context_struct_to_string(struct context *context, char **scontext, 95 u32 *scontext_len); 96 97 static void context_struct_compute_av(struct context *scontext, 98 struct context *tcontext, 99 u16 tclass, 100 struct av_decision *avd, 101 struct extended_perms *xperms); 102 103 struct selinux_mapping { 104 u16 value; /* policy value */ 105 unsigned num_perms; 106 u32 perms[sizeof(u32) * 8]; 107 }; 108 109 static struct selinux_mapping *current_mapping; 110 static u16 current_mapping_size; 111 112 static int selinux_set_mapping(struct policydb *pol, 113 struct security_class_mapping *map, 114 struct selinux_mapping **out_map_p, 115 u16 *out_map_size) 116 { 117 struct selinux_mapping *out_map = NULL; 118 size_t size = sizeof(struct selinux_mapping); 119 u16 i, j; 120 unsigned k; 121 bool print_unknown_handle = false; 122 123 /* Find number of classes in the input mapping */ 124 if (!map) 125 return -EINVAL; 126 i = 0; 127 while (map[i].name) 128 i++; 129 130 /* Allocate space for the class records, plus one for class zero */ 131 out_map = kcalloc(++i, size, GFP_ATOMIC); 132 if (!out_map) 133 return -ENOMEM; 134 135 /* Store the raw class and permission values */ 136 j = 0; 137 while (map[j].name) { 138 struct security_class_mapping *p_in = map + (j++); 139 struct selinux_mapping *p_out = out_map + j; 140 141 /* An empty class string skips ahead */ 142 if (!strcmp(p_in->name, "")) { 143 p_out->num_perms = 0; 144 continue; 145 } 146 147 p_out->value = string_to_security_class(pol, p_in->name); 148 if (!p_out->value) { 149 printk(KERN_INFO 150 "SELinux: Class %s not defined in policy.\n", 151 p_in->name); 152 if (pol->reject_unknown) 153 goto err; 154 p_out->num_perms = 0; 155 print_unknown_handle = true; 156 continue; 157 } 158 159 k = 0; 160 while (p_in->perms[k]) { 161 /* An empty permission string skips ahead */ 162 if (!*p_in->perms[k]) { 163 k++; 164 continue; 165 } 166 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 167 p_in->perms[k]); 168 if (!p_out->perms[k]) { 169 printk(KERN_INFO 170 "SELinux: Permission %s in class %s not defined in policy.\n", 171 p_in->perms[k], p_in->name); 172 if (pol->reject_unknown) 173 goto err; 174 print_unknown_handle = true; 175 } 176 177 k++; 178 } 179 p_out->num_perms = k; 180 } 181 182 if (print_unknown_handle) 183 printk(KERN_INFO "SELinux: the above unknown classes and permissions will be %s\n", 184 pol->allow_unknown ? "allowed" : "denied"); 185 186 *out_map_p = out_map; 187 *out_map_size = i; 188 return 0; 189 err: 190 kfree(out_map); 191 return -EINVAL; 192 } 193 194 /* 195 * Get real, policy values from mapped values 196 */ 197 198 static u16 unmap_class(u16 tclass) 199 { 200 if (tclass < current_mapping_size) 201 return current_mapping[tclass].value; 202 203 return tclass; 204 } 205 206 /* 207 * Get kernel value for class from its policy value 208 */ 209 static u16 map_class(u16 pol_value) 210 { 211 u16 i; 212 213 for (i = 1; i < current_mapping_size; i++) { 214 if (current_mapping[i].value == pol_value) 215 return i; 216 } 217 218 return SECCLASS_NULL; 219 } 220 221 static void map_decision(u16 tclass, struct av_decision *avd, 222 int allow_unknown) 223 { 224 if (tclass < current_mapping_size) { 225 unsigned i, n = current_mapping[tclass].num_perms; 226 u32 result; 227 228 for (i = 0, result = 0; i < n; i++) { 229 if (avd->allowed & current_mapping[tclass].perms[i]) 230 result |= 1<<i; 231 if (allow_unknown && !current_mapping[tclass].perms[i]) 232 result |= 1<<i; 233 } 234 avd->allowed = result; 235 236 for (i = 0, result = 0; i < n; i++) 237 if (avd->auditallow & current_mapping[tclass].perms[i]) 238 result |= 1<<i; 239 avd->auditallow = result; 240 241 for (i = 0, result = 0; i < n; i++) { 242 if (avd->auditdeny & current_mapping[tclass].perms[i]) 243 result |= 1<<i; 244 if (!allow_unknown && !current_mapping[tclass].perms[i]) 245 result |= 1<<i; 246 } 247 /* 248 * In case the kernel has a bug and requests a permission 249 * between num_perms and the maximum permission number, we 250 * should audit that denial 251 */ 252 for (; i < (sizeof(u32)*8); i++) 253 result |= 1<<i; 254 avd->auditdeny = result; 255 } 256 } 257 258 int security_mls_enabled(void) 259 { 260 return policydb.mls_enabled; 261 } 262 263 /* 264 * Return the boolean value of a constraint expression 265 * when it is applied to the specified source and target 266 * security contexts. 267 * 268 * xcontext is a special beast... It is used by the validatetrans rules 269 * only. For these rules, scontext is the context before the transition, 270 * tcontext is the context after the transition, and xcontext is the context 271 * of the process performing the transition. All other callers of 272 * constraint_expr_eval should pass in NULL for xcontext. 273 */ 274 static int constraint_expr_eval(struct context *scontext, 275 struct context *tcontext, 276 struct context *xcontext, 277 struct constraint_expr *cexpr) 278 { 279 u32 val1, val2; 280 struct context *c; 281 struct role_datum *r1, *r2; 282 struct mls_level *l1, *l2; 283 struct constraint_expr *e; 284 int s[CEXPR_MAXDEPTH]; 285 int sp = -1; 286 287 for (e = cexpr; e; e = e->next) { 288 switch (e->expr_type) { 289 case CEXPR_NOT: 290 BUG_ON(sp < 0); 291 s[sp] = !s[sp]; 292 break; 293 case CEXPR_AND: 294 BUG_ON(sp < 1); 295 sp--; 296 s[sp] &= s[sp + 1]; 297 break; 298 case CEXPR_OR: 299 BUG_ON(sp < 1); 300 sp--; 301 s[sp] |= s[sp + 1]; 302 break; 303 case CEXPR_ATTR: 304 if (sp == (CEXPR_MAXDEPTH - 1)) 305 return 0; 306 switch (e->attr) { 307 case CEXPR_USER: 308 val1 = scontext->user; 309 val2 = tcontext->user; 310 break; 311 case CEXPR_TYPE: 312 val1 = scontext->type; 313 val2 = tcontext->type; 314 break; 315 case CEXPR_ROLE: 316 val1 = scontext->role; 317 val2 = tcontext->role; 318 r1 = policydb.role_val_to_struct[val1 - 1]; 319 r2 = policydb.role_val_to_struct[val2 - 1]; 320 switch (e->op) { 321 case CEXPR_DOM: 322 s[++sp] = ebitmap_get_bit(&r1->dominates, 323 val2 - 1); 324 continue; 325 case CEXPR_DOMBY: 326 s[++sp] = ebitmap_get_bit(&r2->dominates, 327 val1 - 1); 328 continue; 329 case CEXPR_INCOMP: 330 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 331 val2 - 1) && 332 !ebitmap_get_bit(&r2->dominates, 333 val1 - 1)); 334 continue; 335 default: 336 break; 337 } 338 break; 339 case CEXPR_L1L2: 340 l1 = &(scontext->range.level[0]); 341 l2 = &(tcontext->range.level[0]); 342 goto mls_ops; 343 case CEXPR_L1H2: 344 l1 = &(scontext->range.level[0]); 345 l2 = &(tcontext->range.level[1]); 346 goto mls_ops; 347 case CEXPR_H1L2: 348 l1 = &(scontext->range.level[1]); 349 l2 = &(tcontext->range.level[0]); 350 goto mls_ops; 351 case CEXPR_H1H2: 352 l1 = &(scontext->range.level[1]); 353 l2 = &(tcontext->range.level[1]); 354 goto mls_ops; 355 case CEXPR_L1H1: 356 l1 = &(scontext->range.level[0]); 357 l2 = &(scontext->range.level[1]); 358 goto mls_ops; 359 case CEXPR_L2H2: 360 l1 = &(tcontext->range.level[0]); 361 l2 = &(tcontext->range.level[1]); 362 goto mls_ops; 363 mls_ops: 364 switch (e->op) { 365 case CEXPR_EQ: 366 s[++sp] = mls_level_eq(l1, l2); 367 continue; 368 case CEXPR_NEQ: 369 s[++sp] = !mls_level_eq(l1, l2); 370 continue; 371 case CEXPR_DOM: 372 s[++sp] = mls_level_dom(l1, l2); 373 continue; 374 case CEXPR_DOMBY: 375 s[++sp] = mls_level_dom(l2, l1); 376 continue; 377 case CEXPR_INCOMP: 378 s[++sp] = mls_level_incomp(l2, l1); 379 continue; 380 default: 381 BUG(); 382 return 0; 383 } 384 break; 385 default: 386 BUG(); 387 return 0; 388 } 389 390 switch (e->op) { 391 case CEXPR_EQ: 392 s[++sp] = (val1 == val2); 393 break; 394 case CEXPR_NEQ: 395 s[++sp] = (val1 != val2); 396 break; 397 default: 398 BUG(); 399 return 0; 400 } 401 break; 402 case CEXPR_NAMES: 403 if (sp == (CEXPR_MAXDEPTH-1)) 404 return 0; 405 c = scontext; 406 if (e->attr & CEXPR_TARGET) 407 c = tcontext; 408 else if (e->attr & CEXPR_XTARGET) { 409 c = xcontext; 410 if (!c) { 411 BUG(); 412 return 0; 413 } 414 } 415 if (e->attr & CEXPR_USER) 416 val1 = c->user; 417 else if (e->attr & CEXPR_ROLE) 418 val1 = c->role; 419 else if (e->attr & CEXPR_TYPE) 420 val1 = c->type; 421 else { 422 BUG(); 423 return 0; 424 } 425 426 switch (e->op) { 427 case CEXPR_EQ: 428 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 429 break; 430 case CEXPR_NEQ: 431 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 432 break; 433 default: 434 BUG(); 435 return 0; 436 } 437 break; 438 default: 439 BUG(); 440 return 0; 441 } 442 } 443 444 BUG_ON(sp != 0); 445 return s[0]; 446 } 447 448 /* 449 * security_dump_masked_av - dumps masked permissions during 450 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 451 */ 452 static int dump_masked_av_helper(void *k, void *d, void *args) 453 { 454 struct perm_datum *pdatum = d; 455 char **permission_names = args; 456 457 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 458 459 permission_names[pdatum->value - 1] = (char *)k; 460 461 return 0; 462 } 463 464 static void security_dump_masked_av(struct context *scontext, 465 struct context *tcontext, 466 u16 tclass, 467 u32 permissions, 468 const char *reason) 469 { 470 struct common_datum *common_dat; 471 struct class_datum *tclass_dat; 472 struct audit_buffer *ab; 473 char *tclass_name; 474 char *scontext_name = NULL; 475 char *tcontext_name = NULL; 476 char *permission_names[32]; 477 int index; 478 u32 length; 479 bool need_comma = false; 480 481 if (!permissions) 482 return; 483 484 tclass_name = sym_name(&policydb, SYM_CLASSES, tclass - 1); 485 tclass_dat = policydb.class_val_to_struct[tclass - 1]; 486 common_dat = tclass_dat->comdatum; 487 488 /* init permission_names */ 489 if (common_dat && 490 hashtab_map(common_dat->permissions.table, 491 dump_masked_av_helper, permission_names) < 0) 492 goto out; 493 494 if (hashtab_map(tclass_dat->permissions.table, 495 dump_masked_av_helper, permission_names) < 0) 496 goto out; 497 498 /* get scontext/tcontext in text form */ 499 if (context_struct_to_string(scontext, 500 &scontext_name, &length) < 0) 501 goto out; 502 503 if (context_struct_to_string(tcontext, 504 &tcontext_name, &length) < 0) 505 goto out; 506 507 /* audit a message */ 508 ab = audit_log_start(current->audit_context, 509 GFP_ATOMIC, AUDIT_SELINUX_ERR); 510 if (!ab) 511 goto out; 512 513 audit_log_format(ab, "op=security_compute_av reason=%s " 514 "scontext=%s tcontext=%s tclass=%s perms=", 515 reason, scontext_name, tcontext_name, tclass_name); 516 517 for (index = 0; index < 32; index++) { 518 u32 mask = (1 << index); 519 520 if ((mask & permissions) == 0) 521 continue; 522 523 audit_log_format(ab, "%s%s", 524 need_comma ? "," : "", 525 permission_names[index] 526 ? permission_names[index] : "????"); 527 need_comma = true; 528 } 529 audit_log_end(ab); 530 out: 531 /* release scontext/tcontext */ 532 kfree(tcontext_name); 533 kfree(scontext_name); 534 535 return; 536 } 537 538 /* 539 * security_boundary_permission - drops violated permissions 540 * on boundary constraint. 541 */ 542 static void type_attribute_bounds_av(struct context *scontext, 543 struct context *tcontext, 544 u16 tclass, 545 struct av_decision *avd) 546 { 547 struct context lo_scontext; 548 struct context lo_tcontext, *tcontextp = tcontext; 549 struct av_decision lo_avd; 550 struct type_datum *source; 551 struct type_datum *target; 552 u32 masked = 0; 553 554 source = flex_array_get_ptr(policydb.type_val_to_struct_array, 555 scontext->type - 1); 556 BUG_ON(!source); 557 558 if (!source->bounds) 559 return; 560 561 target = flex_array_get_ptr(policydb.type_val_to_struct_array, 562 tcontext->type - 1); 563 BUG_ON(!target); 564 565 memset(&lo_avd, 0, sizeof(lo_avd)); 566 567 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 568 lo_scontext.type = source->bounds; 569 570 if (target->bounds) { 571 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 572 lo_tcontext.type = target->bounds; 573 tcontextp = &lo_tcontext; 574 } 575 576 context_struct_compute_av(&lo_scontext, 577 tcontextp, 578 tclass, 579 &lo_avd, 580 NULL); 581 582 masked = ~lo_avd.allowed & avd->allowed; 583 584 if (likely(!masked)) 585 return; /* no masked permission */ 586 587 /* mask violated permissions */ 588 avd->allowed &= ~masked; 589 590 /* audit masked permissions */ 591 security_dump_masked_av(scontext, tcontext, 592 tclass, masked, "bounds"); 593 } 594 595 /* 596 * flag which drivers have permissions 597 * only looking for ioctl based extended permssions 598 */ 599 void services_compute_xperms_drivers( 600 struct extended_perms *xperms, 601 struct avtab_node *node) 602 { 603 unsigned int i; 604 605 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 606 /* if one or more driver has all permissions allowed */ 607 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 608 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 609 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 610 /* if allowing permissions within a driver */ 611 security_xperm_set(xperms->drivers.p, 612 node->datum.u.xperms->driver); 613 } 614 615 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */ 616 if (node->key.specified & AVTAB_XPERMS_ALLOWED) 617 xperms->len = 1; 618 } 619 620 /* 621 * Compute access vectors and extended permissions based on a context 622 * structure pair for the permissions in a particular class. 623 */ 624 static void context_struct_compute_av(struct context *scontext, 625 struct context *tcontext, 626 u16 tclass, 627 struct av_decision *avd, 628 struct extended_perms *xperms) 629 { 630 struct constraint_node *constraint; 631 struct role_allow *ra; 632 struct avtab_key avkey; 633 struct avtab_node *node; 634 struct class_datum *tclass_datum; 635 struct ebitmap *sattr, *tattr; 636 struct ebitmap_node *snode, *tnode; 637 unsigned int i, j; 638 639 avd->allowed = 0; 640 avd->auditallow = 0; 641 avd->auditdeny = 0xffffffff; 642 if (xperms) { 643 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 644 xperms->len = 0; 645 } 646 647 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 648 if (printk_ratelimit()) 649 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass); 650 return; 651 } 652 653 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 654 655 /* 656 * If a specific type enforcement rule was defined for 657 * this permission check, then use it. 658 */ 659 avkey.target_class = tclass; 660 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 661 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1); 662 BUG_ON(!sattr); 663 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1); 664 BUG_ON(!tattr); 665 ebitmap_for_each_positive_bit(sattr, snode, i) { 666 ebitmap_for_each_positive_bit(tattr, tnode, j) { 667 avkey.source_type = i + 1; 668 avkey.target_type = j + 1; 669 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 670 node; 671 node = avtab_search_node_next(node, avkey.specified)) { 672 if (node->key.specified == AVTAB_ALLOWED) 673 avd->allowed |= node->datum.u.data; 674 else if (node->key.specified == AVTAB_AUDITALLOW) 675 avd->auditallow |= node->datum.u.data; 676 else if (node->key.specified == AVTAB_AUDITDENY) 677 avd->auditdeny &= node->datum.u.data; 678 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 679 services_compute_xperms_drivers(xperms, node); 680 } 681 682 /* Check conditional av table for additional permissions */ 683 cond_compute_av(&policydb.te_cond_avtab, &avkey, 684 avd, xperms); 685 686 } 687 } 688 689 /* 690 * Remove any permissions prohibited by a constraint (this includes 691 * the MLS policy). 692 */ 693 constraint = tclass_datum->constraints; 694 while (constraint) { 695 if ((constraint->permissions & (avd->allowed)) && 696 !constraint_expr_eval(scontext, tcontext, NULL, 697 constraint->expr)) { 698 avd->allowed &= ~(constraint->permissions); 699 } 700 constraint = constraint->next; 701 } 702 703 /* 704 * If checking process transition permission and the 705 * role is changing, then check the (current_role, new_role) 706 * pair. 707 */ 708 if (tclass == policydb.process_class && 709 (avd->allowed & policydb.process_trans_perms) && 710 scontext->role != tcontext->role) { 711 for (ra = policydb.role_allow; ra; ra = ra->next) { 712 if (scontext->role == ra->role && 713 tcontext->role == ra->new_role) 714 break; 715 } 716 if (!ra) 717 avd->allowed &= ~policydb.process_trans_perms; 718 } 719 720 /* 721 * If the given source and target types have boundary 722 * constraint, lazy checks have to mask any violated 723 * permission and notice it to userspace via audit. 724 */ 725 type_attribute_bounds_av(scontext, tcontext, 726 tclass, avd); 727 } 728 729 static int security_validtrans_handle_fail(struct context *ocontext, 730 struct context *ncontext, 731 struct context *tcontext, 732 u16 tclass) 733 { 734 char *o = NULL, *n = NULL, *t = NULL; 735 u32 olen, nlen, tlen; 736 737 if (context_struct_to_string(ocontext, &o, &olen)) 738 goto out; 739 if (context_struct_to_string(ncontext, &n, &nlen)) 740 goto out; 741 if (context_struct_to_string(tcontext, &t, &tlen)) 742 goto out; 743 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 744 "op=security_validate_transition seresult=denied" 745 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 746 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 747 out: 748 kfree(o); 749 kfree(n); 750 kfree(t); 751 752 if (!selinux_enforcing) 753 return 0; 754 return -EPERM; 755 } 756 757 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid, 758 u16 orig_tclass, bool user) 759 { 760 struct context *ocontext; 761 struct context *ncontext; 762 struct context *tcontext; 763 struct class_datum *tclass_datum; 764 struct constraint_node *constraint; 765 u16 tclass; 766 int rc = 0; 767 768 if (!ss_initialized) 769 return 0; 770 771 read_lock(&policy_rwlock); 772 773 if (!user) 774 tclass = unmap_class(orig_tclass); 775 else 776 tclass = orig_tclass; 777 778 if (!tclass || tclass > policydb.p_classes.nprim) { 779 rc = -EINVAL; 780 goto out; 781 } 782 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 783 784 ocontext = sidtab_search(&sidtab, oldsid); 785 if (!ocontext) { 786 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 787 __func__, oldsid); 788 rc = -EINVAL; 789 goto out; 790 } 791 792 ncontext = sidtab_search(&sidtab, newsid); 793 if (!ncontext) { 794 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 795 __func__, newsid); 796 rc = -EINVAL; 797 goto out; 798 } 799 800 tcontext = sidtab_search(&sidtab, tasksid); 801 if (!tcontext) { 802 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 803 __func__, tasksid); 804 rc = -EINVAL; 805 goto out; 806 } 807 808 constraint = tclass_datum->validatetrans; 809 while (constraint) { 810 if (!constraint_expr_eval(ocontext, ncontext, tcontext, 811 constraint->expr)) { 812 if (user) 813 rc = -EPERM; 814 else 815 rc = security_validtrans_handle_fail(ocontext, 816 ncontext, 817 tcontext, 818 tclass); 819 goto out; 820 } 821 constraint = constraint->next; 822 } 823 824 out: 825 read_unlock(&policy_rwlock); 826 return rc; 827 } 828 829 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, 830 u16 tclass) 831 { 832 return security_compute_validatetrans(oldsid, newsid, tasksid, 833 tclass, true); 834 } 835 836 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 837 u16 orig_tclass) 838 { 839 return security_compute_validatetrans(oldsid, newsid, tasksid, 840 orig_tclass, false); 841 } 842 843 /* 844 * security_bounded_transition - check whether the given 845 * transition is directed to bounded, or not. 846 * It returns 0, if @newsid is bounded by @oldsid. 847 * Otherwise, it returns error code. 848 * 849 * @oldsid : current security identifier 850 * @newsid : destinated security identifier 851 */ 852 int security_bounded_transition(u32 old_sid, u32 new_sid) 853 { 854 struct context *old_context, *new_context; 855 struct type_datum *type; 856 int index; 857 int rc; 858 859 read_lock(&policy_rwlock); 860 861 rc = -EINVAL; 862 old_context = sidtab_search(&sidtab, old_sid); 863 if (!old_context) { 864 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 865 __func__, old_sid); 866 goto out; 867 } 868 869 rc = -EINVAL; 870 new_context = sidtab_search(&sidtab, new_sid); 871 if (!new_context) { 872 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 873 __func__, new_sid); 874 goto out; 875 } 876 877 rc = 0; 878 /* type/domain unchanged */ 879 if (old_context->type == new_context->type) 880 goto out; 881 882 index = new_context->type; 883 while (true) { 884 type = flex_array_get_ptr(policydb.type_val_to_struct_array, 885 index - 1); 886 BUG_ON(!type); 887 888 /* not bounded anymore */ 889 rc = -EPERM; 890 if (!type->bounds) 891 break; 892 893 /* @newsid is bounded by @oldsid */ 894 rc = 0; 895 if (type->bounds == old_context->type) 896 break; 897 898 index = type->bounds; 899 } 900 901 if (rc) { 902 char *old_name = NULL; 903 char *new_name = NULL; 904 u32 length; 905 906 if (!context_struct_to_string(old_context, 907 &old_name, &length) && 908 !context_struct_to_string(new_context, 909 &new_name, &length)) { 910 audit_log(current->audit_context, 911 GFP_ATOMIC, AUDIT_SELINUX_ERR, 912 "op=security_bounded_transition " 913 "seresult=denied " 914 "oldcontext=%s newcontext=%s", 915 old_name, new_name); 916 } 917 kfree(new_name); 918 kfree(old_name); 919 } 920 out: 921 read_unlock(&policy_rwlock); 922 923 return rc; 924 } 925 926 static void avd_init(struct av_decision *avd) 927 { 928 avd->allowed = 0; 929 avd->auditallow = 0; 930 avd->auditdeny = 0xffffffff; 931 avd->seqno = latest_granting; 932 avd->flags = 0; 933 } 934 935 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 936 struct avtab_node *node) 937 { 938 unsigned int i; 939 940 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 941 if (xpermd->driver != node->datum.u.xperms->driver) 942 return; 943 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 944 if (!security_xperm_test(node->datum.u.xperms->perms.p, 945 xpermd->driver)) 946 return; 947 } else { 948 BUG(); 949 } 950 951 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 952 xpermd->used |= XPERMS_ALLOWED; 953 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 954 memset(xpermd->allowed->p, 0xff, 955 sizeof(xpermd->allowed->p)); 956 } 957 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 958 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 959 xpermd->allowed->p[i] |= 960 node->datum.u.xperms->perms.p[i]; 961 } 962 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 963 xpermd->used |= XPERMS_AUDITALLOW; 964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 965 memset(xpermd->auditallow->p, 0xff, 966 sizeof(xpermd->auditallow->p)); 967 } 968 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 969 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 970 xpermd->auditallow->p[i] |= 971 node->datum.u.xperms->perms.p[i]; 972 } 973 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 974 xpermd->used |= XPERMS_DONTAUDIT; 975 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 976 memset(xpermd->dontaudit->p, 0xff, 977 sizeof(xpermd->dontaudit->p)); 978 } 979 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 980 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 981 xpermd->dontaudit->p[i] |= 982 node->datum.u.xperms->perms.p[i]; 983 } 984 } else { 985 BUG(); 986 } 987 } 988 989 void security_compute_xperms_decision(u32 ssid, 990 u32 tsid, 991 u16 orig_tclass, 992 u8 driver, 993 struct extended_perms_decision *xpermd) 994 { 995 u16 tclass; 996 struct context *scontext, *tcontext; 997 struct avtab_key avkey; 998 struct avtab_node *node; 999 struct ebitmap *sattr, *tattr; 1000 struct ebitmap_node *snode, *tnode; 1001 unsigned int i, j; 1002 1003 xpermd->driver = driver; 1004 xpermd->used = 0; 1005 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1006 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1007 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1008 1009 read_lock(&policy_rwlock); 1010 if (!ss_initialized) 1011 goto allow; 1012 1013 scontext = sidtab_search(&sidtab, ssid); 1014 if (!scontext) { 1015 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1016 __func__, ssid); 1017 goto out; 1018 } 1019 1020 tcontext = sidtab_search(&sidtab, tsid); 1021 if (!tcontext) { 1022 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1023 __func__, tsid); 1024 goto out; 1025 } 1026 1027 tclass = unmap_class(orig_tclass); 1028 if (unlikely(orig_tclass && !tclass)) { 1029 if (policydb.allow_unknown) 1030 goto allow; 1031 goto out; 1032 } 1033 1034 1035 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 1036 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1037 goto out; 1038 } 1039 1040 avkey.target_class = tclass; 1041 avkey.specified = AVTAB_XPERMS; 1042 sattr = flex_array_get(policydb.type_attr_map_array, 1043 scontext->type - 1); 1044 BUG_ON(!sattr); 1045 tattr = flex_array_get(policydb.type_attr_map_array, 1046 tcontext->type - 1); 1047 BUG_ON(!tattr); 1048 ebitmap_for_each_positive_bit(sattr, snode, i) { 1049 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1050 avkey.source_type = i + 1; 1051 avkey.target_type = j + 1; 1052 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 1053 node; 1054 node = avtab_search_node_next(node, avkey.specified)) 1055 services_compute_xperms_decision(xpermd, node); 1056 1057 cond_compute_xperms(&policydb.te_cond_avtab, 1058 &avkey, xpermd); 1059 } 1060 } 1061 out: 1062 read_unlock(&policy_rwlock); 1063 return; 1064 allow: 1065 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1066 goto out; 1067 } 1068 1069 /** 1070 * security_compute_av - Compute access vector decisions. 1071 * @ssid: source security identifier 1072 * @tsid: target security identifier 1073 * @tclass: target security class 1074 * @avd: access vector decisions 1075 * @xperms: extended permissions 1076 * 1077 * Compute a set of access vector decisions based on the 1078 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1079 */ 1080 void security_compute_av(u32 ssid, 1081 u32 tsid, 1082 u16 orig_tclass, 1083 struct av_decision *avd, 1084 struct extended_perms *xperms) 1085 { 1086 u16 tclass; 1087 struct context *scontext = NULL, *tcontext = NULL; 1088 1089 read_lock(&policy_rwlock); 1090 avd_init(avd); 1091 xperms->len = 0; 1092 if (!ss_initialized) 1093 goto allow; 1094 1095 scontext = sidtab_search(&sidtab, ssid); 1096 if (!scontext) { 1097 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1098 __func__, ssid); 1099 goto out; 1100 } 1101 1102 /* permissive domain? */ 1103 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1104 avd->flags |= AVD_FLAGS_PERMISSIVE; 1105 1106 tcontext = sidtab_search(&sidtab, tsid); 1107 if (!tcontext) { 1108 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1109 __func__, tsid); 1110 goto out; 1111 } 1112 1113 tclass = unmap_class(orig_tclass); 1114 if (unlikely(orig_tclass && !tclass)) { 1115 if (policydb.allow_unknown) 1116 goto allow; 1117 goto out; 1118 } 1119 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms); 1120 map_decision(orig_tclass, avd, policydb.allow_unknown); 1121 out: 1122 read_unlock(&policy_rwlock); 1123 return; 1124 allow: 1125 avd->allowed = 0xffffffff; 1126 goto out; 1127 } 1128 1129 void security_compute_av_user(u32 ssid, 1130 u32 tsid, 1131 u16 tclass, 1132 struct av_decision *avd) 1133 { 1134 struct context *scontext = NULL, *tcontext = NULL; 1135 1136 read_lock(&policy_rwlock); 1137 avd_init(avd); 1138 if (!ss_initialized) 1139 goto allow; 1140 1141 scontext = sidtab_search(&sidtab, ssid); 1142 if (!scontext) { 1143 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1144 __func__, ssid); 1145 goto out; 1146 } 1147 1148 /* permissive domain? */ 1149 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1150 avd->flags |= AVD_FLAGS_PERMISSIVE; 1151 1152 tcontext = sidtab_search(&sidtab, tsid); 1153 if (!tcontext) { 1154 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1155 __func__, tsid); 1156 goto out; 1157 } 1158 1159 if (unlikely(!tclass)) { 1160 if (policydb.allow_unknown) 1161 goto allow; 1162 goto out; 1163 } 1164 1165 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL); 1166 out: 1167 read_unlock(&policy_rwlock); 1168 return; 1169 allow: 1170 avd->allowed = 0xffffffff; 1171 goto out; 1172 } 1173 1174 /* 1175 * Write the security context string representation of 1176 * the context structure `context' into a dynamically 1177 * allocated string of the correct size. Set `*scontext' 1178 * to point to this string and set `*scontext_len' to 1179 * the length of the string. 1180 */ 1181 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) 1182 { 1183 char *scontextp; 1184 1185 if (scontext) 1186 *scontext = NULL; 1187 *scontext_len = 0; 1188 1189 if (context->len) { 1190 *scontext_len = context->len; 1191 if (scontext) { 1192 *scontext = kstrdup(context->str, GFP_ATOMIC); 1193 if (!(*scontext)) 1194 return -ENOMEM; 1195 } 1196 return 0; 1197 } 1198 1199 /* Compute the size of the context. */ 1200 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1; 1201 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1; 1202 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1; 1203 *scontext_len += mls_compute_context_len(context); 1204 1205 if (!scontext) 1206 return 0; 1207 1208 /* Allocate space for the context; caller must free this space. */ 1209 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1210 if (!scontextp) 1211 return -ENOMEM; 1212 *scontext = scontextp; 1213 1214 /* 1215 * Copy the user name, role name and type name into the context. 1216 */ 1217 scontextp += sprintf(scontextp, "%s:%s:%s", 1218 sym_name(&policydb, SYM_USERS, context->user - 1), 1219 sym_name(&policydb, SYM_ROLES, context->role - 1), 1220 sym_name(&policydb, SYM_TYPES, context->type - 1)); 1221 1222 mls_sid_to_context(context, &scontextp); 1223 1224 *scontextp = 0; 1225 1226 return 0; 1227 } 1228 1229 #include "initial_sid_to_string.h" 1230 1231 const char *security_get_initial_sid_context(u32 sid) 1232 { 1233 if (unlikely(sid > SECINITSID_NUM)) 1234 return NULL; 1235 return initial_sid_to_string[sid]; 1236 } 1237 1238 static int security_sid_to_context_core(u32 sid, char **scontext, 1239 u32 *scontext_len, int force) 1240 { 1241 struct context *context; 1242 int rc = 0; 1243 1244 if (scontext) 1245 *scontext = NULL; 1246 *scontext_len = 0; 1247 1248 if (!ss_initialized) { 1249 if (sid <= SECINITSID_NUM) { 1250 char *scontextp; 1251 1252 *scontext_len = strlen(initial_sid_to_string[sid]) + 1; 1253 if (!scontext) 1254 goto out; 1255 scontextp = kmemdup(initial_sid_to_string[sid], 1256 *scontext_len, GFP_ATOMIC); 1257 if (!scontextp) { 1258 rc = -ENOMEM; 1259 goto out; 1260 } 1261 *scontext = scontextp; 1262 goto out; 1263 } 1264 printk(KERN_ERR "SELinux: %s: called before initial " 1265 "load_policy on unknown SID %d\n", __func__, sid); 1266 rc = -EINVAL; 1267 goto out; 1268 } 1269 read_lock(&policy_rwlock); 1270 if (force) 1271 context = sidtab_search_force(&sidtab, sid); 1272 else 1273 context = sidtab_search(&sidtab, sid); 1274 if (!context) { 1275 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1276 __func__, sid); 1277 rc = -EINVAL; 1278 goto out_unlock; 1279 } 1280 rc = context_struct_to_string(context, scontext, scontext_len); 1281 out_unlock: 1282 read_unlock(&policy_rwlock); 1283 out: 1284 return rc; 1285 1286 } 1287 1288 /** 1289 * security_sid_to_context - Obtain a context for a given SID. 1290 * @sid: security identifier, SID 1291 * @scontext: security context 1292 * @scontext_len: length in bytes 1293 * 1294 * Write the string representation of the context associated with @sid 1295 * into a dynamically allocated string of the correct size. Set @scontext 1296 * to point to this string and set @scontext_len to the length of the string. 1297 */ 1298 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1299 { 1300 return security_sid_to_context_core(sid, scontext, scontext_len, 0); 1301 } 1302 1303 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len) 1304 { 1305 return security_sid_to_context_core(sid, scontext, scontext_len, 1); 1306 } 1307 1308 /* 1309 * Caveat: Mutates scontext. 1310 */ 1311 static int string_to_context_struct(struct policydb *pol, 1312 struct sidtab *sidtabp, 1313 char *scontext, 1314 u32 scontext_len, 1315 struct context *ctx, 1316 u32 def_sid) 1317 { 1318 struct role_datum *role; 1319 struct type_datum *typdatum; 1320 struct user_datum *usrdatum; 1321 char *scontextp, *p, oldc; 1322 int rc = 0; 1323 1324 context_init(ctx); 1325 1326 /* Parse the security context. */ 1327 1328 rc = -EINVAL; 1329 scontextp = (char *) scontext; 1330 1331 /* Extract the user. */ 1332 p = scontextp; 1333 while (*p && *p != ':') 1334 p++; 1335 1336 if (*p == 0) 1337 goto out; 1338 1339 *p++ = 0; 1340 1341 usrdatum = hashtab_search(pol->p_users.table, scontextp); 1342 if (!usrdatum) 1343 goto out; 1344 1345 ctx->user = usrdatum->value; 1346 1347 /* Extract role. */ 1348 scontextp = p; 1349 while (*p && *p != ':') 1350 p++; 1351 1352 if (*p == 0) 1353 goto out; 1354 1355 *p++ = 0; 1356 1357 role = hashtab_search(pol->p_roles.table, scontextp); 1358 if (!role) 1359 goto out; 1360 ctx->role = role->value; 1361 1362 /* Extract type. */ 1363 scontextp = p; 1364 while (*p && *p != ':') 1365 p++; 1366 oldc = *p; 1367 *p++ = 0; 1368 1369 typdatum = hashtab_search(pol->p_types.table, scontextp); 1370 if (!typdatum || typdatum->attribute) 1371 goto out; 1372 1373 ctx->type = typdatum->value; 1374 1375 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid); 1376 if (rc) 1377 goto out; 1378 1379 rc = -EINVAL; 1380 if ((p - scontext) < scontext_len) 1381 goto out; 1382 1383 /* Check the validity of the new context. */ 1384 if (!policydb_context_isvalid(pol, ctx)) 1385 goto out; 1386 rc = 0; 1387 out: 1388 if (rc) 1389 context_destroy(ctx); 1390 return rc; 1391 } 1392 1393 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1394 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1395 int force) 1396 { 1397 char *scontext2, *str = NULL; 1398 struct context context; 1399 int rc = 0; 1400 1401 /* An empty security context is never valid. */ 1402 if (!scontext_len) 1403 return -EINVAL; 1404 1405 if (!ss_initialized) { 1406 int i; 1407 1408 for (i = 1; i < SECINITSID_NUM; i++) { 1409 if (!strcmp(initial_sid_to_string[i], scontext)) { 1410 *sid = i; 1411 return 0; 1412 } 1413 } 1414 *sid = SECINITSID_KERNEL; 1415 return 0; 1416 } 1417 *sid = SECSID_NULL; 1418 1419 /* Copy the string so that we can modify the copy as we parse it. */ 1420 scontext2 = kmalloc(scontext_len + 1, gfp_flags); 1421 if (!scontext2) 1422 return -ENOMEM; 1423 memcpy(scontext2, scontext, scontext_len); 1424 scontext2[scontext_len] = 0; 1425 1426 if (force) { 1427 /* Save another copy for storing in uninterpreted form */ 1428 rc = -ENOMEM; 1429 str = kstrdup(scontext2, gfp_flags); 1430 if (!str) 1431 goto out; 1432 } 1433 1434 read_lock(&policy_rwlock); 1435 rc = string_to_context_struct(&policydb, &sidtab, scontext2, 1436 scontext_len, &context, def_sid); 1437 if (rc == -EINVAL && force) { 1438 context.str = str; 1439 context.len = scontext_len; 1440 str = NULL; 1441 } else if (rc) 1442 goto out_unlock; 1443 rc = sidtab_context_to_sid(&sidtab, &context, sid); 1444 context_destroy(&context); 1445 out_unlock: 1446 read_unlock(&policy_rwlock); 1447 out: 1448 kfree(scontext2); 1449 kfree(str); 1450 return rc; 1451 } 1452 1453 /** 1454 * security_context_to_sid - Obtain a SID for a given security context. 1455 * @scontext: security context 1456 * @scontext_len: length in bytes 1457 * @sid: security identifier, SID 1458 * @gfp: context for the allocation 1459 * 1460 * Obtains a SID associated with the security context that 1461 * has the string representation specified by @scontext. 1462 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1463 * memory is available, or 0 on success. 1464 */ 1465 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1466 gfp_t gfp) 1467 { 1468 return security_context_to_sid_core(scontext, scontext_len, 1469 sid, SECSID_NULL, gfp, 0); 1470 } 1471 1472 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1473 { 1474 return security_context_to_sid(scontext, strlen(scontext), sid, gfp); 1475 } 1476 1477 /** 1478 * security_context_to_sid_default - Obtain a SID for a given security context, 1479 * falling back to specified default if needed. 1480 * 1481 * @scontext: security context 1482 * @scontext_len: length in bytes 1483 * @sid: security identifier, SID 1484 * @def_sid: default SID to assign on error 1485 * 1486 * Obtains a SID associated with the security context that 1487 * has the string representation specified by @scontext. 1488 * The default SID is passed to the MLS layer to be used to allow 1489 * kernel labeling of the MLS field if the MLS field is not present 1490 * (for upgrading to MLS without full relabel). 1491 * Implicitly forces adding of the context even if it cannot be mapped yet. 1492 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1493 * memory is available, or 0 on success. 1494 */ 1495 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1496 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1497 { 1498 return security_context_to_sid_core(scontext, scontext_len, 1499 sid, def_sid, gfp_flags, 1); 1500 } 1501 1502 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1503 u32 *sid) 1504 { 1505 return security_context_to_sid_core(scontext, scontext_len, 1506 sid, SECSID_NULL, GFP_KERNEL, 1); 1507 } 1508 1509 static int compute_sid_handle_invalid_context( 1510 struct context *scontext, 1511 struct context *tcontext, 1512 u16 tclass, 1513 struct context *newcontext) 1514 { 1515 char *s = NULL, *t = NULL, *n = NULL; 1516 u32 slen, tlen, nlen; 1517 1518 if (context_struct_to_string(scontext, &s, &slen)) 1519 goto out; 1520 if (context_struct_to_string(tcontext, &t, &tlen)) 1521 goto out; 1522 if (context_struct_to_string(newcontext, &n, &nlen)) 1523 goto out; 1524 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 1525 "op=security_compute_sid invalid_context=%s" 1526 " scontext=%s" 1527 " tcontext=%s" 1528 " tclass=%s", 1529 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 1530 out: 1531 kfree(s); 1532 kfree(t); 1533 kfree(n); 1534 if (!selinux_enforcing) 1535 return 0; 1536 return -EACCES; 1537 } 1538 1539 static void filename_compute_type(struct policydb *p, struct context *newcontext, 1540 u32 stype, u32 ttype, u16 tclass, 1541 const char *objname) 1542 { 1543 struct filename_trans ft; 1544 struct filename_trans_datum *otype; 1545 1546 /* 1547 * Most filename trans rules are going to live in specific directories 1548 * like /dev or /var/run. This bitmap will quickly skip rule searches 1549 * if the ttype does not contain any rules. 1550 */ 1551 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype)) 1552 return; 1553 1554 ft.stype = stype; 1555 ft.ttype = ttype; 1556 ft.tclass = tclass; 1557 ft.name = objname; 1558 1559 otype = hashtab_search(p->filename_trans, &ft); 1560 if (otype) 1561 newcontext->type = otype->otype; 1562 } 1563 1564 static int security_compute_sid(u32 ssid, 1565 u32 tsid, 1566 u16 orig_tclass, 1567 u32 specified, 1568 const char *objname, 1569 u32 *out_sid, 1570 bool kern) 1571 { 1572 struct class_datum *cladatum = NULL; 1573 struct context *scontext = NULL, *tcontext = NULL, newcontext; 1574 struct role_trans *roletr = NULL; 1575 struct avtab_key avkey; 1576 struct avtab_datum *avdatum; 1577 struct avtab_node *node; 1578 u16 tclass; 1579 int rc = 0; 1580 bool sock; 1581 1582 if (!ss_initialized) { 1583 switch (orig_tclass) { 1584 case SECCLASS_PROCESS: /* kernel value */ 1585 *out_sid = ssid; 1586 break; 1587 default: 1588 *out_sid = tsid; 1589 break; 1590 } 1591 goto out; 1592 } 1593 1594 context_init(&newcontext); 1595 1596 read_lock(&policy_rwlock); 1597 1598 if (kern) { 1599 tclass = unmap_class(orig_tclass); 1600 sock = security_is_socket_class(orig_tclass); 1601 } else { 1602 tclass = orig_tclass; 1603 sock = security_is_socket_class(map_class(tclass)); 1604 } 1605 1606 scontext = sidtab_search(&sidtab, ssid); 1607 if (!scontext) { 1608 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1609 __func__, ssid); 1610 rc = -EINVAL; 1611 goto out_unlock; 1612 } 1613 tcontext = sidtab_search(&sidtab, tsid); 1614 if (!tcontext) { 1615 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1616 __func__, tsid); 1617 rc = -EINVAL; 1618 goto out_unlock; 1619 } 1620 1621 if (tclass && tclass <= policydb.p_classes.nprim) 1622 cladatum = policydb.class_val_to_struct[tclass - 1]; 1623 1624 /* Set the user identity. */ 1625 switch (specified) { 1626 case AVTAB_TRANSITION: 1627 case AVTAB_CHANGE: 1628 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1629 newcontext.user = tcontext->user; 1630 } else { 1631 /* notice this gets both DEFAULT_SOURCE and unset */ 1632 /* Use the process user identity. */ 1633 newcontext.user = scontext->user; 1634 } 1635 break; 1636 case AVTAB_MEMBER: 1637 /* Use the related object owner. */ 1638 newcontext.user = tcontext->user; 1639 break; 1640 } 1641 1642 /* Set the role to default values. */ 1643 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1644 newcontext.role = scontext->role; 1645 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1646 newcontext.role = tcontext->role; 1647 } else { 1648 if ((tclass == policydb.process_class) || (sock == true)) 1649 newcontext.role = scontext->role; 1650 else 1651 newcontext.role = OBJECT_R_VAL; 1652 } 1653 1654 /* Set the type to default values. */ 1655 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1656 newcontext.type = scontext->type; 1657 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1658 newcontext.type = tcontext->type; 1659 } else { 1660 if ((tclass == policydb.process_class) || (sock == true)) { 1661 /* Use the type of process. */ 1662 newcontext.type = scontext->type; 1663 } else { 1664 /* Use the type of the related object. */ 1665 newcontext.type = tcontext->type; 1666 } 1667 } 1668 1669 /* Look for a type transition/member/change rule. */ 1670 avkey.source_type = scontext->type; 1671 avkey.target_type = tcontext->type; 1672 avkey.target_class = tclass; 1673 avkey.specified = specified; 1674 avdatum = avtab_search(&policydb.te_avtab, &avkey); 1675 1676 /* If no permanent rule, also check for enabled conditional rules */ 1677 if (!avdatum) { 1678 node = avtab_search_node(&policydb.te_cond_avtab, &avkey); 1679 for (; node; node = avtab_search_node_next(node, specified)) { 1680 if (node->key.specified & AVTAB_ENABLED) { 1681 avdatum = &node->datum; 1682 break; 1683 } 1684 } 1685 } 1686 1687 if (avdatum) { 1688 /* Use the type from the type transition/member/change rule. */ 1689 newcontext.type = avdatum->u.data; 1690 } 1691 1692 /* if we have a objname this is a file trans check so check those rules */ 1693 if (objname) 1694 filename_compute_type(&policydb, &newcontext, scontext->type, 1695 tcontext->type, tclass, objname); 1696 1697 /* Check for class-specific changes. */ 1698 if (specified & AVTAB_TRANSITION) { 1699 /* Look for a role transition rule. */ 1700 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) { 1701 if ((roletr->role == scontext->role) && 1702 (roletr->type == tcontext->type) && 1703 (roletr->tclass == tclass)) { 1704 /* Use the role transition rule. */ 1705 newcontext.role = roletr->new_role; 1706 break; 1707 } 1708 } 1709 } 1710 1711 /* Set the MLS attributes. 1712 This is done last because it may allocate memory. */ 1713 rc = mls_compute_sid(scontext, tcontext, tclass, specified, 1714 &newcontext, sock); 1715 if (rc) 1716 goto out_unlock; 1717 1718 /* Check the validity of the context. */ 1719 if (!policydb_context_isvalid(&policydb, &newcontext)) { 1720 rc = compute_sid_handle_invalid_context(scontext, 1721 tcontext, 1722 tclass, 1723 &newcontext); 1724 if (rc) 1725 goto out_unlock; 1726 } 1727 /* Obtain the sid for the context. */ 1728 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); 1729 out_unlock: 1730 read_unlock(&policy_rwlock); 1731 context_destroy(&newcontext); 1732 out: 1733 return rc; 1734 } 1735 1736 /** 1737 * security_transition_sid - Compute the SID for a new subject/object. 1738 * @ssid: source security identifier 1739 * @tsid: target security identifier 1740 * @tclass: target security class 1741 * @out_sid: security identifier for new subject/object 1742 * 1743 * Compute a SID to use for labeling a new subject or object in the 1744 * class @tclass based on a SID pair (@ssid, @tsid). 1745 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1746 * if insufficient memory is available, or %0 if the new SID was 1747 * computed successfully. 1748 */ 1749 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1750 const struct qstr *qstr, u32 *out_sid) 1751 { 1752 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1753 qstr ? qstr->name : NULL, out_sid, true); 1754 } 1755 1756 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1757 const char *objname, u32 *out_sid) 1758 { 1759 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1760 objname, out_sid, false); 1761 } 1762 1763 /** 1764 * security_member_sid - Compute the SID for member selection. 1765 * @ssid: source security identifier 1766 * @tsid: target security identifier 1767 * @tclass: target security class 1768 * @out_sid: security identifier for selected member 1769 * 1770 * Compute a SID to use when selecting a member of a polyinstantiated 1771 * object of class @tclass based on a SID pair (@ssid, @tsid). 1772 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1773 * if insufficient memory is available, or %0 if the SID was 1774 * computed successfully. 1775 */ 1776 int security_member_sid(u32 ssid, 1777 u32 tsid, 1778 u16 tclass, 1779 u32 *out_sid) 1780 { 1781 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL, 1782 out_sid, false); 1783 } 1784 1785 /** 1786 * security_change_sid - Compute the SID for object relabeling. 1787 * @ssid: source security identifier 1788 * @tsid: target security identifier 1789 * @tclass: target security class 1790 * @out_sid: security identifier for selected member 1791 * 1792 * Compute a SID to use for relabeling an object of class @tclass 1793 * based on a SID pair (@ssid, @tsid). 1794 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1795 * if insufficient memory is available, or %0 if the SID was 1796 * computed successfully. 1797 */ 1798 int security_change_sid(u32 ssid, 1799 u32 tsid, 1800 u16 tclass, 1801 u32 *out_sid) 1802 { 1803 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1804 out_sid, false); 1805 } 1806 1807 /* Clone the SID into the new SID table. */ 1808 static int clone_sid(u32 sid, 1809 struct context *context, 1810 void *arg) 1811 { 1812 struct sidtab *s = arg; 1813 1814 if (sid > SECINITSID_NUM) 1815 return sidtab_insert(s, sid, context); 1816 else 1817 return 0; 1818 } 1819 1820 static inline int convert_context_handle_invalid_context(struct context *context) 1821 { 1822 char *s; 1823 u32 len; 1824 1825 if (selinux_enforcing) 1826 return -EINVAL; 1827 1828 if (!context_struct_to_string(context, &s, &len)) { 1829 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s); 1830 kfree(s); 1831 } 1832 return 0; 1833 } 1834 1835 struct convert_context_args { 1836 struct policydb *oldp; 1837 struct policydb *newp; 1838 }; 1839 1840 /* 1841 * Convert the values in the security context 1842 * structure `c' from the values specified 1843 * in the policy `p->oldp' to the values specified 1844 * in the policy `p->newp'. Verify that the 1845 * context is valid under the new policy. 1846 */ 1847 static int convert_context(u32 key, 1848 struct context *c, 1849 void *p) 1850 { 1851 struct convert_context_args *args; 1852 struct context oldc; 1853 struct ocontext *oc; 1854 struct mls_range *range; 1855 struct role_datum *role; 1856 struct type_datum *typdatum; 1857 struct user_datum *usrdatum; 1858 char *s; 1859 u32 len; 1860 int rc = 0; 1861 1862 if (key <= SECINITSID_NUM) 1863 goto out; 1864 1865 args = p; 1866 1867 if (c->str) { 1868 struct context ctx; 1869 1870 rc = -ENOMEM; 1871 s = kstrdup(c->str, GFP_KERNEL); 1872 if (!s) 1873 goto out; 1874 1875 rc = string_to_context_struct(args->newp, NULL, s, 1876 c->len, &ctx, SECSID_NULL); 1877 kfree(s); 1878 if (!rc) { 1879 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n", 1880 c->str); 1881 /* Replace string with mapped representation. */ 1882 kfree(c->str); 1883 memcpy(c, &ctx, sizeof(*c)); 1884 goto out; 1885 } else if (rc == -EINVAL) { 1886 /* Retain string representation for later mapping. */ 1887 rc = 0; 1888 goto out; 1889 } else { 1890 /* Other error condition, e.g. ENOMEM. */ 1891 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n", 1892 c->str, -rc); 1893 goto out; 1894 } 1895 } 1896 1897 rc = context_cpy(&oldc, c); 1898 if (rc) 1899 goto out; 1900 1901 /* Convert the user. */ 1902 rc = -EINVAL; 1903 usrdatum = hashtab_search(args->newp->p_users.table, 1904 sym_name(args->oldp, SYM_USERS, c->user - 1)); 1905 if (!usrdatum) 1906 goto bad; 1907 c->user = usrdatum->value; 1908 1909 /* Convert the role. */ 1910 rc = -EINVAL; 1911 role = hashtab_search(args->newp->p_roles.table, 1912 sym_name(args->oldp, SYM_ROLES, c->role - 1)); 1913 if (!role) 1914 goto bad; 1915 c->role = role->value; 1916 1917 /* Convert the type. */ 1918 rc = -EINVAL; 1919 typdatum = hashtab_search(args->newp->p_types.table, 1920 sym_name(args->oldp, SYM_TYPES, c->type - 1)); 1921 if (!typdatum) 1922 goto bad; 1923 c->type = typdatum->value; 1924 1925 /* Convert the MLS fields if dealing with MLS policies */ 1926 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 1927 rc = mls_convert_context(args->oldp, args->newp, c); 1928 if (rc) 1929 goto bad; 1930 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) { 1931 /* 1932 * Switching between MLS and non-MLS policy: 1933 * free any storage used by the MLS fields in the 1934 * context for all existing entries in the sidtab. 1935 */ 1936 mls_context_destroy(c); 1937 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 1938 /* 1939 * Switching between non-MLS and MLS policy: 1940 * ensure that the MLS fields of the context for all 1941 * existing entries in the sidtab are filled in with a 1942 * suitable default value, likely taken from one of the 1943 * initial SIDs. 1944 */ 1945 oc = args->newp->ocontexts[OCON_ISID]; 1946 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 1947 oc = oc->next; 1948 rc = -EINVAL; 1949 if (!oc) { 1950 printk(KERN_ERR "SELinux: unable to look up" 1951 " the initial SIDs list\n"); 1952 goto bad; 1953 } 1954 range = &oc->context[0].range; 1955 rc = mls_range_set(c, range); 1956 if (rc) 1957 goto bad; 1958 } 1959 1960 /* Check the validity of the new context. */ 1961 if (!policydb_context_isvalid(args->newp, c)) { 1962 rc = convert_context_handle_invalid_context(&oldc); 1963 if (rc) 1964 goto bad; 1965 } 1966 1967 context_destroy(&oldc); 1968 1969 rc = 0; 1970 out: 1971 return rc; 1972 bad: 1973 /* Map old representation to string and save it. */ 1974 rc = context_struct_to_string(&oldc, &s, &len); 1975 if (rc) 1976 return rc; 1977 context_destroy(&oldc); 1978 context_destroy(c); 1979 c->str = s; 1980 c->len = len; 1981 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n", 1982 c->str); 1983 rc = 0; 1984 goto out; 1985 } 1986 1987 static void security_load_policycaps(void) 1988 { 1989 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps, 1990 POLICYDB_CAPABILITY_NETPEER); 1991 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps, 1992 POLICYDB_CAPABILITY_OPENPERM); 1993 selinux_policycap_extsockclass = ebitmap_get_bit(&policydb.policycaps, 1994 POLICYDB_CAPABILITY_EXTSOCKCLASS); 1995 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps, 1996 POLICYDB_CAPABILITY_ALWAYSNETWORK); 1997 selinux_policycap_cgroupseclabel = 1998 ebitmap_get_bit(&policydb.policycaps, 1999 POLICYDB_CAPABILITY_CGROUPSECLABEL); 2000 } 2001 2002 static int security_preserve_bools(struct policydb *p); 2003 2004 /** 2005 * security_load_policy - Load a security policy configuration. 2006 * @data: binary policy data 2007 * @len: length of data in bytes 2008 * 2009 * Load a new set of security policy configuration data, 2010 * validate it and convert the SID table as necessary. 2011 * This function will flush the access vector cache after 2012 * loading the new policy. 2013 */ 2014 int security_load_policy(void *data, size_t len) 2015 { 2016 struct policydb *oldpolicydb, *newpolicydb; 2017 struct sidtab oldsidtab, newsidtab; 2018 struct selinux_mapping *oldmap, *map = NULL; 2019 struct convert_context_args args; 2020 u32 seqno; 2021 u16 map_size; 2022 int rc = 0; 2023 struct policy_file file = { data, len }, *fp = &file; 2024 2025 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL); 2026 if (!oldpolicydb) { 2027 rc = -ENOMEM; 2028 goto out; 2029 } 2030 newpolicydb = oldpolicydb + 1; 2031 2032 if (!ss_initialized) { 2033 avtab_cache_init(); 2034 rc = policydb_read(&policydb, fp); 2035 if (rc) { 2036 avtab_cache_destroy(); 2037 goto out; 2038 } 2039 2040 policydb.len = len; 2041 rc = selinux_set_mapping(&policydb, secclass_map, 2042 ¤t_mapping, 2043 ¤t_mapping_size); 2044 if (rc) { 2045 policydb_destroy(&policydb); 2046 avtab_cache_destroy(); 2047 goto out; 2048 } 2049 2050 rc = policydb_load_isids(&policydb, &sidtab); 2051 if (rc) { 2052 policydb_destroy(&policydb); 2053 avtab_cache_destroy(); 2054 goto out; 2055 } 2056 2057 security_load_policycaps(); 2058 ss_initialized = 1; 2059 seqno = ++latest_granting; 2060 selinux_complete_init(); 2061 avc_ss_reset(seqno); 2062 selnl_notify_policyload(seqno); 2063 selinux_status_update_policyload(seqno); 2064 selinux_netlbl_cache_invalidate(); 2065 selinux_xfrm_notify_policyload(); 2066 goto out; 2067 } 2068 2069 #if 0 2070 sidtab_hash_eval(&sidtab, "sids"); 2071 #endif 2072 2073 rc = policydb_read(newpolicydb, fp); 2074 if (rc) 2075 goto out; 2076 2077 newpolicydb->len = len; 2078 /* If switching between different policy types, log MLS status */ 2079 if (policydb.mls_enabled && !newpolicydb->mls_enabled) 2080 printk(KERN_INFO "SELinux: Disabling MLS support...\n"); 2081 else if (!policydb.mls_enabled && newpolicydb->mls_enabled) 2082 printk(KERN_INFO "SELinux: Enabling MLS support...\n"); 2083 2084 rc = policydb_load_isids(newpolicydb, &newsidtab); 2085 if (rc) { 2086 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n"); 2087 policydb_destroy(newpolicydb); 2088 goto out; 2089 } 2090 2091 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size); 2092 if (rc) 2093 goto err; 2094 2095 rc = security_preserve_bools(newpolicydb); 2096 if (rc) { 2097 printk(KERN_ERR "SELinux: unable to preserve booleans\n"); 2098 goto err; 2099 } 2100 2101 /* Clone the SID table. */ 2102 sidtab_shutdown(&sidtab); 2103 2104 rc = sidtab_map(&sidtab, clone_sid, &newsidtab); 2105 if (rc) 2106 goto err; 2107 2108 /* 2109 * Convert the internal representations of contexts 2110 * in the new SID table. 2111 */ 2112 args.oldp = &policydb; 2113 args.newp = newpolicydb; 2114 rc = sidtab_map(&newsidtab, convert_context, &args); 2115 if (rc) { 2116 printk(KERN_ERR "SELinux: unable to convert the internal" 2117 " representation of contexts in the new SID" 2118 " table\n"); 2119 goto err; 2120 } 2121 2122 /* Save the old policydb and SID table to free later. */ 2123 memcpy(oldpolicydb, &policydb, sizeof(policydb)); 2124 sidtab_set(&oldsidtab, &sidtab); 2125 2126 /* Install the new policydb and SID table. */ 2127 write_lock_irq(&policy_rwlock); 2128 memcpy(&policydb, newpolicydb, sizeof(policydb)); 2129 sidtab_set(&sidtab, &newsidtab); 2130 security_load_policycaps(); 2131 oldmap = current_mapping; 2132 current_mapping = map; 2133 current_mapping_size = map_size; 2134 seqno = ++latest_granting; 2135 write_unlock_irq(&policy_rwlock); 2136 2137 /* Free the old policydb and SID table. */ 2138 policydb_destroy(oldpolicydb); 2139 sidtab_destroy(&oldsidtab); 2140 kfree(oldmap); 2141 2142 avc_ss_reset(seqno); 2143 selnl_notify_policyload(seqno); 2144 selinux_status_update_policyload(seqno); 2145 selinux_netlbl_cache_invalidate(); 2146 selinux_xfrm_notify_policyload(); 2147 2148 rc = 0; 2149 goto out; 2150 2151 err: 2152 kfree(map); 2153 sidtab_destroy(&newsidtab); 2154 policydb_destroy(newpolicydb); 2155 2156 out: 2157 kfree(oldpolicydb); 2158 return rc; 2159 } 2160 2161 size_t security_policydb_len(void) 2162 { 2163 size_t len; 2164 2165 read_lock(&policy_rwlock); 2166 len = policydb.len; 2167 read_unlock(&policy_rwlock); 2168 2169 return len; 2170 } 2171 2172 /** 2173 * security_port_sid - Obtain the SID for a port. 2174 * @protocol: protocol number 2175 * @port: port number 2176 * @out_sid: security identifier 2177 */ 2178 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2179 { 2180 struct ocontext *c; 2181 int rc = 0; 2182 2183 read_lock(&policy_rwlock); 2184 2185 c = policydb.ocontexts[OCON_PORT]; 2186 while (c) { 2187 if (c->u.port.protocol == protocol && 2188 c->u.port.low_port <= port && 2189 c->u.port.high_port >= port) 2190 break; 2191 c = c->next; 2192 } 2193 2194 if (c) { 2195 if (!c->sid[0]) { 2196 rc = sidtab_context_to_sid(&sidtab, 2197 &c->context[0], 2198 &c->sid[0]); 2199 if (rc) 2200 goto out; 2201 } 2202 *out_sid = c->sid[0]; 2203 } else { 2204 *out_sid = SECINITSID_PORT; 2205 } 2206 2207 out: 2208 read_unlock(&policy_rwlock); 2209 return rc; 2210 } 2211 2212 /** 2213 * security_netif_sid - Obtain the SID for a network interface. 2214 * @name: interface name 2215 * @if_sid: interface SID 2216 */ 2217 int security_netif_sid(char *name, u32 *if_sid) 2218 { 2219 int rc = 0; 2220 struct ocontext *c; 2221 2222 read_lock(&policy_rwlock); 2223 2224 c = policydb.ocontexts[OCON_NETIF]; 2225 while (c) { 2226 if (strcmp(name, c->u.name) == 0) 2227 break; 2228 c = c->next; 2229 } 2230 2231 if (c) { 2232 if (!c->sid[0] || !c->sid[1]) { 2233 rc = sidtab_context_to_sid(&sidtab, 2234 &c->context[0], 2235 &c->sid[0]); 2236 if (rc) 2237 goto out; 2238 rc = sidtab_context_to_sid(&sidtab, 2239 &c->context[1], 2240 &c->sid[1]); 2241 if (rc) 2242 goto out; 2243 } 2244 *if_sid = c->sid[0]; 2245 } else 2246 *if_sid = SECINITSID_NETIF; 2247 2248 out: 2249 read_unlock(&policy_rwlock); 2250 return rc; 2251 } 2252 2253 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2254 { 2255 int i, fail = 0; 2256 2257 for (i = 0; i < 4; i++) 2258 if (addr[i] != (input[i] & mask[i])) { 2259 fail = 1; 2260 break; 2261 } 2262 2263 return !fail; 2264 } 2265 2266 /** 2267 * security_node_sid - Obtain the SID for a node (host). 2268 * @domain: communication domain aka address family 2269 * @addrp: address 2270 * @addrlen: address length in bytes 2271 * @out_sid: security identifier 2272 */ 2273 int security_node_sid(u16 domain, 2274 void *addrp, 2275 u32 addrlen, 2276 u32 *out_sid) 2277 { 2278 int rc; 2279 struct ocontext *c; 2280 2281 read_lock(&policy_rwlock); 2282 2283 switch (domain) { 2284 case AF_INET: { 2285 u32 addr; 2286 2287 rc = -EINVAL; 2288 if (addrlen != sizeof(u32)) 2289 goto out; 2290 2291 addr = *((u32 *)addrp); 2292 2293 c = policydb.ocontexts[OCON_NODE]; 2294 while (c) { 2295 if (c->u.node.addr == (addr & c->u.node.mask)) 2296 break; 2297 c = c->next; 2298 } 2299 break; 2300 } 2301 2302 case AF_INET6: 2303 rc = -EINVAL; 2304 if (addrlen != sizeof(u64) * 2) 2305 goto out; 2306 c = policydb.ocontexts[OCON_NODE6]; 2307 while (c) { 2308 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2309 c->u.node6.mask)) 2310 break; 2311 c = c->next; 2312 } 2313 break; 2314 2315 default: 2316 rc = 0; 2317 *out_sid = SECINITSID_NODE; 2318 goto out; 2319 } 2320 2321 if (c) { 2322 if (!c->sid[0]) { 2323 rc = sidtab_context_to_sid(&sidtab, 2324 &c->context[0], 2325 &c->sid[0]); 2326 if (rc) 2327 goto out; 2328 } 2329 *out_sid = c->sid[0]; 2330 } else { 2331 *out_sid = SECINITSID_NODE; 2332 } 2333 2334 rc = 0; 2335 out: 2336 read_unlock(&policy_rwlock); 2337 return rc; 2338 } 2339 2340 #define SIDS_NEL 25 2341 2342 /** 2343 * security_get_user_sids - Obtain reachable SIDs for a user. 2344 * @fromsid: starting SID 2345 * @username: username 2346 * @sids: array of reachable SIDs for user 2347 * @nel: number of elements in @sids 2348 * 2349 * Generate the set of SIDs for legal security contexts 2350 * for a given user that can be reached by @fromsid. 2351 * Set *@sids to point to a dynamically allocated 2352 * array containing the set of SIDs. Set *@nel to the 2353 * number of elements in the array. 2354 */ 2355 2356 int security_get_user_sids(u32 fromsid, 2357 char *username, 2358 u32 **sids, 2359 u32 *nel) 2360 { 2361 struct context *fromcon, usercon; 2362 u32 *mysids = NULL, *mysids2, sid; 2363 u32 mynel = 0, maxnel = SIDS_NEL; 2364 struct user_datum *user; 2365 struct role_datum *role; 2366 struct ebitmap_node *rnode, *tnode; 2367 int rc = 0, i, j; 2368 2369 *sids = NULL; 2370 *nel = 0; 2371 2372 if (!ss_initialized) 2373 goto out; 2374 2375 read_lock(&policy_rwlock); 2376 2377 context_init(&usercon); 2378 2379 rc = -EINVAL; 2380 fromcon = sidtab_search(&sidtab, fromsid); 2381 if (!fromcon) 2382 goto out_unlock; 2383 2384 rc = -EINVAL; 2385 user = hashtab_search(policydb.p_users.table, username); 2386 if (!user) 2387 goto out_unlock; 2388 2389 usercon.user = user->value; 2390 2391 rc = -ENOMEM; 2392 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); 2393 if (!mysids) 2394 goto out_unlock; 2395 2396 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2397 role = policydb.role_val_to_struct[i]; 2398 usercon.role = i + 1; 2399 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2400 usercon.type = j + 1; 2401 2402 if (mls_setup_user_range(fromcon, user, &usercon)) 2403 continue; 2404 2405 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); 2406 if (rc) 2407 goto out_unlock; 2408 if (mynel < maxnel) { 2409 mysids[mynel++] = sid; 2410 } else { 2411 rc = -ENOMEM; 2412 maxnel += SIDS_NEL; 2413 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2414 if (!mysids2) 2415 goto out_unlock; 2416 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2417 kfree(mysids); 2418 mysids = mysids2; 2419 mysids[mynel++] = sid; 2420 } 2421 } 2422 } 2423 rc = 0; 2424 out_unlock: 2425 read_unlock(&policy_rwlock); 2426 if (rc || !mynel) { 2427 kfree(mysids); 2428 goto out; 2429 } 2430 2431 rc = -ENOMEM; 2432 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2433 if (!mysids2) { 2434 kfree(mysids); 2435 goto out; 2436 } 2437 for (i = 0, j = 0; i < mynel; i++) { 2438 struct av_decision dummy_avd; 2439 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2440 SECCLASS_PROCESS, /* kernel value */ 2441 PROCESS__TRANSITION, AVC_STRICT, 2442 &dummy_avd); 2443 if (!rc) 2444 mysids2[j++] = mysids[i]; 2445 cond_resched(); 2446 } 2447 rc = 0; 2448 kfree(mysids); 2449 *sids = mysids2; 2450 *nel = j; 2451 out: 2452 return rc; 2453 } 2454 2455 /** 2456 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2457 * @fstype: filesystem type 2458 * @path: path from root of mount 2459 * @sclass: file security class 2460 * @sid: SID for path 2461 * 2462 * Obtain a SID to use for a file in a filesystem that 2463 * cannot support xattr or use a fixed labeling behavior like 2464 * transition SIDs or task SIDs. 2465 * 2466 * The caller must acquire the policy_rwlock before calling this function. 2467 */ 2468 static inline int __security_genfs_sid(const char *fstype, 2469 char *path, 2470 u16 orig_sclass, 2471 u32 *sid) 2472 { 2473 int len; 2474 u16 sclass; 2475 struct genfs *genfs; 2476 struct ocontext *c; 2477 int rc, cmp = 0; 2478 2479 while (path[0] == '/' && path[1] == '/') 2480 path++; 2481 2482 sclass = unmap_class(orig_sclass); 2483 *sid = SECINITSID_UNLABELED; 2484 2485 for (genfs = policydb.genfs; genfs; genfs = genfs->next) { 2486 cmp = strcmp(fstype, genfs->fstype); 2487 if (cmp <= 0) 2488 break; 2489 } 2490 2491 rc = -ENOENT; 2492 if (!genfs || cmp) 2493 goto out; 2494 2495 for (c = genfs->head; c; c = c->next) { 2496 len = strlen(c->u.name); 2497 if ((!c->v.sclass || sclass == c->v.sclass) && 2498 (strncmp(c->u.name, path, len) == 0)) 2499 break; 2500 } 2501 2502 rc = -ENOENT; 2503 if (!c) 2504 goto out; 2505 2506 if (!c->sid[0]) { 2507 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); 2508 if (rc) 2509 goto out; 2510 } 2511 2512 *sid = c->sid[0]; 2513 rc = 0; 2514 out: 2515 return rc; 2516 } 2517 2518 /** 2519 * security_genfs_sid - Obtain a SID for a file in a filesystem 2520 * @fstype: filesystem type 2521 * @path: path from root of mount 2522 * @sclass: file security class 2523 * @sid: SID for path 2524 * 2525 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2526 * it afterward. 2527 */ 2528 int security_genfs_sid(const char *fstype, 2529 char *path, 2530 u16 orig_sclass, 2531 u32 *sid) 2532 { 2533 int retval; 2534 2535 read_lock(&policy_rwlock); 2536 retval = __security_genfs_sid(fstype, path, orig_sclass, sid); 2537 read_unlock(&policy_rwlock); 2538 return retval; 2539 } 2540 2541 /** 2542 * security_fs_use - Determine how to handle labeling for a filesystem. 2543 * @sb: superblock in question 2544 */ 2545 int security_fs_use(struct super_block *sb) 2546 { 2547 int rc = 0; 2548 struct ocontext *c; 2549 struct superblock_security_struct *sbsec = sb->s_security; 2550 const char *fstype = sb->s_type->name; 2551 2552 read_lock(&policy_rwlock); 2553 2554 c = policydb.ocontexts[OCON_FSUSE]; 2555 while (c) { 2556 if (strcmp(fstype, c->u.name) == 0) 2557 break; 2558 c = c->next; 2559 } 2560 2561 if (c) { 2562 sbsec->behavior = c->v.behavior; 2563 if (!c->sid[0]) { 2564 rc = sidtab_context_to_sid(&sidtab, &c->context[0], 2565 &c->sid[0]); 2566 if (rc) 2567 goto out; 2568 } 2569 sbsec->sid = c->sid[0]; 2570 } else { 2571 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR, 2572 &sbsec->sid); 2573 if (rc) { 2574 sbsec->behavior = SECURITY_FS_USE_NONE; 2575 rc = 0; 2576 } else { 2577 sbsec->behavior = SECURITY_FS_USE_GENFS; 2578 } 2579 } 2580 2581 out: 2582 read_unlock(&policy_rwlock); 2583 return rc; 2584 } 2585 2586 int security_get_bools(int *len, char ***names, int **values) 2587 { 2588 int i, rc; 2589 2590 read_lock(&policy_rwlock); 2591 *names = NULL; 2592 *values = NULL; 2593 2594 rc = 0; 2595 *len = policydb.p_bools.nprim; 2596 if (!*len) 2597 goto out; 2598 2599 rc = -ENOMEM; 2600 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2601 if (!*names) 2602 goto err; 2603 2604 rc = -ENOMEM; 2605 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2606 if (!*values) 2607 goto err; 2608 2609 for (i = 0; i < *len; i++) { 2610 (*values)[i] = policydb.bool_val_to_struct[i]->state; 2611 2612 rc = -ENOMEM; 2613 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC); 2614 if (!(*names)[i]) 2615 goto err; 2616 } 2617 rc = 0; 2618 out: 2619 read_unlock(&policy_rwlock); 2620 return rc; 2621 err: 2622 if (*names) { 2623 for (i = 0; i < *len; i++) 2624 kfree((*names)[i]); 2625 } 2626 kfree(*values); 2627 goto out; 2628 } 2629 2630 2631 int security_set_bools(int len, int *values) 2632 { 2633 int i, rc; 2634 int lenp, seqno = 0; 2635 struct cond_node *cur; 2636 2637 write_lock_irq(&policy_rwlock); 2638 2639 rc = -EFAULT; 2640 lenp = policydb.p_bools.nprim; 2641 if (len != lenp) 2642 goto out; 2643 2644 for (i = 0; i < len; i++) { 2645 if (!!values[i] != policydb.bool_val_to_struct[i]->state) { 2646 audit_log(current->audit_context, GFP_ATOMIC, 2647 AUDIT_MAC_CONFIG_CHANGE, 2648 "bool=%s val=%d old_val=%d auid=%u ses=%u", 2649 sym_name(&policydb, SYM_BOOLS, i), 2650 !!values[i], 2651 policydb.bool_val_to_struct[i]->state, 2652 from_kuid(&init_user_ns, audit_get_loginuid(current)), 2653 audit_get_sessionid(current)); 2654 } 2655 if (values[i]) 2656 policydb.bool_val_to_struct[i]->state = 1; 2657 else 2658 policydb.bool_val_to_struct[i]->state = 0; 2659 } 2660 2661 for (cur = policydb.cond_list; cur; cur = cur->next) { 2662 rc = evaluate_cond_node(&policydb, cur); 2663 if (rc) 2664 goto out; 2665 } 2666 2667 seqno = ++latest_granting; 2668 rc = 0; 2669 out: 2670 write_unlock_irq(&policy_rwlock); 2671 if (!rc) { 2672 avc_ss_reset(seqno); 2673 selnl_notify_policyload(seqno); 2674 selinux_status_update_policyload(seqno); 2675 selinux_xfrm_notify_policyload(); 2676 } 2677 return rc; 2678 } 2679 2680 int security_get_bool_value(int index) 2681 { 2682 int rc; 2683 int len; 2684 2685 read_lock(&policy_rwlock); 2686 2687 rc = -EFAULT; 2688 len = policydb.p_bools.nprim; 2689 if (index >= len) 2690 goto out; 2691 2692 rc = policydb.bool_val_to_struct[index]->state; 2693 out: 2694 read_unlock(&policy_rwlock); 2695 return rc; 2696 } 2697 2698 static int security_preserve_bools(struct policydb *p) 2699 { 2700 int rc, nbools = 0, *bvalues = NULL, i; 2701 char **bnames = NULL; 2702 struct cond_bool_datum *booldatum; 2703 struct cond_node *cur; 2704 2705 rc = security_get_bools(&nbools, &bnames, &bvalues); 2706 if (rc) 2707 goto out; 2708 for (i = 0; i < nbools; i++) { 2709 booldatum = hashtab_search(p->p_bools.table, bnames[i]); 2710 if (booldatum) 2711 booldatum->state = bvalues[i]; 2712 } 2713 for (cur = p->cond_list; cur; cur = cur->next) { 2714 rc = evaluate_cond_node(p, cur); 2715 if (rc) 2716 goto out; 2717 } 2718 2719 out: 2720 if (bnames) { 2721 for (i = 0; i < nbools; i++) 2722 kfree(bnames[i]); 2723 } 2724 kfree(bnames); 2725 kfree(bvalues); 2726 return rc; 2727 } 2728 2729 /* 2730 * security_sid_mls_copy() - computes a new sid based on the given 2731 * sid and the mls portion of mls_sid. 2732 */ 2733 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 2734 { 2735 struct context *context1; 2736 struct context *context2; 2737 struct context newcon; 2738 char *s; 2739 u32 len; 2740 int rc; 2741 2742 rc = 0; 2743 if (!ss_initialized || !policydb.mls_enabled) { 2744 *new_sid = sid; 2745 goto out; 2746 } 2747 2748 context_init(&newcon); 2749 2750 read_lock(&policy_rwlock); 2751 2752 rc = -EINVAL; 2753 context1 = sidtab_search(&sidtab, sid); 2754 if (!context1) { 2755 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2756 __func__, sid); 2757 goto out_unlock; 2758 } 2759 2760 rc = -EINVAL; 2761 context2 = sidtab_search(&sidtab, mls_sid); 2762 if (!context2) { 2763 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2764 __func__, mls_sid); 2765 goto out_unlock; 2766 } 2767 2768 newcon.user = context1->user; 2769 newcon.role = context1->role; 2770 newcon.type = context1->type; 2771 rc = mls_context_cpy(&newcon, context2); 2772 if (rc) 2773 goto out_unlock; 2774 2775 /* Check the validity of the new context. */ 2776 if (!policydb_context_isvalid(&policydb, &newcon)) { 2777 rc = convert_context_handle_invalid_context(&newcon); 2778 if (rc) { 2779 if (!context_struct_to_string(&newcon, &s, &len)) { 2780 audit_log(current->audit_context, 2781 GFP_ATOMIC, AUDIT_SELINUX_ERR, 2782 "op=security_sid_mls_copy " 2783 "invalid_context=%s", s); 2784 kfree(s); 2785 } 2786 goto out_unlock; 2787 } 2788 } 2789 2790 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid); 2791 out_unlock: 2792 read_unlock(&policy_rwlock); 2793 context_destroy(&newcon); 2794 out: 2795 return rc; 2796 } 2797 2798 /** 2799 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 2800 * @nlbl_sid: NetLabel SID 2801 * @nlbl_type: NetLabel labeling protocol type 2802 * @xfrm_sid: XFRM SID 2803 * 2804 * Description: 2805 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 2806 * resolved into a single SID it is returned via @peer_sid and the function 2807 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 2808 * returns a negative value. A table summarizing the behavior is below: 2809 * 2810 * | function return | @sid 2811 * ------------------------------+-----------------+----------------- 2812 * no peer labels | 0 | SECSID_NULL 2813 * single peer label | 0 | <peer_label> 2814 * multiple, consistent labels | 0 | <peer_label> 2815 * multiple, inconsistent labels | -<errno> | SECSID_NULL 2816 * 2817 */ 2818 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 2819 u32 xfrm_sid, 2820 u32 *peer_sid) 2821 { 2822 int rc; 2823 struct context *nlbl_ctx; 2824 struct context *xfrm_ctx; 2825 2826 *peer_sid = SECSID_NULL; 2827 2828 /* handle the common (which also happens to be the set of easy) cases 2829 * right away, these two if statements catch everything involving a 2830 * single or absent peer SID/label */ 2831 if (xfrm_sid == SECSID_NULL) { 2832 *peer_sid = nlbl_sid; 2833 return 0; 2834 } 2835 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 2836 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 2837 * is present */ 2838 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 2839 *peer_sid = xfrm_sid; 2840 return 0; 2841 } 2842 2843 /* we don't need to check ss_initialized here since the only way both 2844 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 2845 * security server was initialized and ss_initialized was true */ 2846 if (!policydb.mls_enabled) 2847 return 0; 2848 2849 read_lock(&policy_rwlock); 2850 2851 rc = -EINVAL; 2852 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid); 2853 if (!nlbl_ctx) { 2854 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2855 __func__, nlbl_sid); 2856 goto out; 2857 } 2858 rc = -EINVAL; 2859 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid); 2860 if (!xfrm_ctx) { 2861 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2862 __func__, xfrm_sid); 2863 goto out; 2864 } 2865 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 2866 if (rc) 2867 goto out; 2868 2869 /* at present NetLabel SIDs/labels really only carry MLS 2870 * information so if the MLS portion of the NetLabel SID 2871 * matches the MLS portion of the labeled XFRM SID/label 2872 * then pass along the XFRM SID as it is the most 2873 * expressive */ 2874 *peer_sid = xfrm_sid; 2875 out: 2876 read_unlock(&policy_rwlock); 2877 return rc; 2878 } 2879 2880 static int get_classes_callback(void *k, void *d, void *args) 2881 { 2882 struct class_datum *datum = d; 2883 char *name = k, **classes = args; 2884 int value = datum->value - 1; 2885 2886 classes[value] = kstrdup(name, GFP_ATOMIC); 2887 if (!classes[value]) 2888 return -ENOMEM; 2889 2890 return 0; 2891 } 2892 2893 int security_get_classes(char ***classes, int *nclasses) 2894 { 2895 int rc; 2896 2897 read_lock(&policy_rwlock); 2898 2899 rc = -ENOMEM; 2900 *nclasses = policydb.p_classes.nprim; 2901 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 2902 if (!*classes) 2903 goto out; 2904 2905 rc = hashtab_map(policydb.p_classes.table, get_classes_callback, 2906 *classes); 2907 if (rc) { 2908 int i; 2909 for (i = 0; i < *nclasses; i++) 2910 kfree((*classes)[i]); 2911 kfree(*classes); 2912 } 2913 2914 out: 2915 read_unlock(&policy_rwlock); 2916 return rc; 2917 } 2918 2919 static int get_permissions_callback(void *k, void *d, void *args) 2920 { 2921 struct perm_datum *datum = d; 2922 char *name = k, **perms = args; 2923 int value = datum->value - 1; 2924 2925 perms[value] = kstrdup(name, GFP_ATOMIC); 2926 if (!perms[value]) 2927 return -ENOMEM; 2928 2929 return 0; 2930 } 2931 2932 int security_get_permissions(char *class, char ***perms, int *nperms) 2933 { 2934 int rc, i; 2935 struct class_datum *match; 2936 2937 read_lock(&policy_rwlock); 2938 2939 rc = -EINVAL; 2940 match = hashtab_search(policydb.p_classes.table, class); 2941 if (!match) { 2942 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n", 2943 __func__, class); 2944 goto out; 2945 } 2946 2947 rc = -ENOMEM; 2948 *nperms = match->permissions.nprim; 2949 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 2950 if (!*perms) 2951 goto out; 2952 2953 if (match->comdatum) { 2954 rc = hashtab_map(match->comdatum->permissions.table, 2955 get_permissions_callback, *perms); 2956 if (rc) 2957 goto err; 2958 } 2959 2960 rc = hashtab_map(match->permissions.table, get_permissions_callback, 2961 *perms); 2962 if (rc) 2963 goto err; 2964 2965 out: 2966 read_unlock(&policy_rwlock); 2967 return rc; 2968 2969 err: 2970 read_unlock(&policy_rwlock); 2971 for (i = 0; i < *nperms; i++) 2972 kfree((*perms)[i]); 2973 kfree(*perms); 2974 return rc; 2975 } 2976 2977 int security_get_reject_unknown(void) 2978 { 2979 return policydb.reject_unknown; 2980 } 2981 2982 int security_get_allow_unknown(void) 2983 { 2984 return policydb.allow_unknown; 2985 } 2986 2987 /** 2988 * security_policycap_supported - Check for a specific policy capability 2989 * @req_cap: capability 2990 * 2991 * Description: 2992 * This function queries the currently loaded policy to see if it supports the 2993 * capability specified by @req_cap. Returns true (1) if the capability is 2994 * supported, false (0) if it isn't supported. 2995 * 2996 */ 2997 int security_policycap_supported(unsigned int req_cap) 2998 { 2999 int rc; 3000 3001 read_lock(&policy_rwlock); 3002 rc = ebitmap_get_bit(&policydb.policycaps, req_cap); 3003 read_unlock(&policy_rwlock); 3004 3005 return rc; 3006 } 3007 3008 struct selinux_audit_rule { 3009 u32 au_seqno; 3010 struct context au_ctxt; 3011 }; 3012 3013 void selinux_audit_rule_free(void *vrule) 3014 { 3015 struct selinux_audit_rule *rule = vrule; 3016 3017 if (rule) { 3018 context_destroy(&rule->au_ctxt); 3019 kfree(rule); 3020 } 3021 } 3022 3023 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3024 { 3025 struct selinux_audit_rule *tmprule; 3026 struct role_datum *roledatum; 3027 struct type_datum *typedatum; 3028 struct user_datum *userdatum; 3029 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3030 int rc = 0; 3031 3032 *rule = NULL; 3033 3034 if (!ss_initialized) 3035 return -EOPNOTSUPP; 3036 3037 switch (field) { 3038 case AUDIT_SUBJ_USER: 3039 case AUDIT_SUBJ_ROLE: 3040 case AUDIT_SUBJ_TYPE: 3041 case AUDIT_OBJ_USER: 3042 case AUDIT_OBJ_ROLE: 3043 case AUDIT_OBJ_TYPE: 3044 /* only 'equals' and 'not equals' fit user, role, and type */ 3045 if (op != Audit_equal && op != Audit_not_equal) 3046 return -EINVAL; 3047 break; 3048 case AUDIT_SUBJ_SEN: 3049 case AUDIT_SUBJ_CLR: 3050 case AUDIT_OBJ_LEV_LOW: 3051 case AUDIT_OBJ_LEV_HIGH: 3052 /* we do not allow a range, indicated by the presence of '-' */ 3053 if (strchr(rulestr, '-')) 3054 return -EINVAL; 3055 break; 3056 default: 3057 /* only the above fields are valid */ 3058 return -EINVAL; 3059 } 3060 3061 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3062 if (!tmprule) 3063 return -ENOMEM; 3064 3065 context_init(&tmprule->au_ctxt); 3066 3067 read_lock(&policy_rwlock); 3068 3069 tmprule->au_seqno = latest_granting; 3070 3071 switch (field) { 3072 case AUDIT_SUBJ_USER: 3073 case AUDIT_OBJ_USER: 3074 rc = -EINVAL; 3075 userdatum = hashtab_search(policydb.p_users.table, rulestr); 3076 if (!userdatum) 3077 goto out; 3078 tmprule->au_ctxt.user = userdatum->value; 3079 break; 3080 case AUDIT_SUBJ_ROLE: 3081 case AUDIT_OBJ_ROLE: 3082 rc = -EINVAL; 3083 roledatum = hashtab_search(policydb.p_roles.table, rulestr); 3084 if (!roledatum) 3085 goto out; 3086 tmprule->au_ctxt.role = roledatum->value; 3087 break; 3088 case AUDIT_SUBJ_TYPE: 3089 case AUDIT_OBJ_TYPE: 3090 rc = -EINVAL; 3091 typedatum = hashtab_search(policydb.p_types.table, rulestr); 3092 if (!typedatum) 3093 goto out; 3094 tmprule->au_ctxt.type = typedatum->value; 3095 break; 3096 case AUDIT_SUBJ_SEN: 3097 case AUDIT_SUBJ_CLR: 3098 case AUDIT_OBJ_LEV_LOW: 3099 case AUDIT_OBJ_LEV_HIGH: 3100 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC); 3101 if (rc) 3102 goto out; 3103 break; 3104 } 3105 rc = 0; 3106 out: 3107 read_unlock(&policy_rwlock); 3108 3109 if (rc) { 3110 selinux_audit_rule_free(tmprule); 3111 tmprule = NULL; 3112 } 3113 3114 *rule = tmprule; 3115 3116 return rc; 3117 } 3118 3119 /* Check to see if the rule contains any selinux fields */ 3120 int selinux_audit_rule_known(struct audit_krule *rule) 3121 { 3122 int i; 3123 3124 for (i = 0; i < rule->field_count; i++) { 3125 struct audit_field *f = &rule->fields[i]; 3126 switch (f->type) { 3127 case AUDIT_SUBJ_USER: 3128 case AUDIT_SUBJ_ROLE: 3129 case AUDIT_SUBJ_TYPE: 3130 case AUDIT_SUBJ_SEN: 3131 case AUDIT_SUBJ_CLR: 3132 case AUDIT_OBJ_USER: 3133 case AUDIT_OBJ_ROLE: 3134 case AUDIT_OBJ_TYPE: 3135 case AUDIT_OBJ_LEV_LOW: 3136 case AUDIT_OBJ_LEV_HIGH: 3137 return 1; 3138 } 3139 } 3140 3141 return 0; 3142 } 3143 3144 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, 3145 struct audit_context *actx) 3146 { 3147 struct context *ctxt; 3148 struct mls_level *level; 3149 struct selinux_audit_rule *rule = vrule; 3150 int match = 0; 3151 3152 if (unlikely(!rule)) { 3153 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3154 return -ENOENT; 3155 } 3156 3157 read_lock(&policy_rwlock); 3158 3159 if (rule->au_seqno < latest_granting) { 3160 match = -ESTALE; 3161 goto out; 3162 } 3163 3164 ctxt = sidtab_search(&sidtab, sid); 3165 if (unlikely(!ctxt)) { 3166 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3167 sid); 3168 match = -ENOENT; 3169 goto out; 3170 } 3171 3172 /* a field/op pair that is not caught here will simply fall through 3173 without a match */ 3174 switch (field) { 3175 case AUDIT_SUBJ_USER: 3176 case AUDIT_OBJ_USER: 3177 switch (op) { 3178 case Audit_equal: 3179 match = (ctxt->user == rule->au_ctxt.user); 3180 break; 3181 case Audit_not_equal: 3182 match = (ctxt->user != rule->au_ctxt.user); 3183 break; 3184 } 3185 break; 3186 case AUDIT_SUBJ_ROLE: 3187 case AUDIT_OBJ_ROLE: 3188 switch (op) { 3189 case Audit_equal: 3190 match = (ctxt->role == rule->au_ctxt.role); 3191 break; 3192 case Audit_not_equal: 3193 match = (ctxt->role != rule->au_ctxt.role); 3194 break; 3195 } 3196 break; 3197 case AUDIT_SUBJ_TYPE: 3198 case AUDIT_OBJ_TYPE: 3199 switch (op) { 3200 case Audit_equal: 3201 match = (ctxt->type == rule->au_ctxt.type); 3202 break; 3203 case Audit_not_equal: 3204 match = (ctxt->type != rule->au_ctxt.type); 3205 break; 3206 } 3207 break; 3208 case AUDIT_SUBJ_SEN: 3209 case AUDIT_SUBJ_CLR: 3210 case AUDIT_OBJ_LEV_LOW: 3211 case AUDIT_OBJ_LEV_HIGH: 3212 level = ((field == AUDIT_SUBJ_SEN || 3213 field == AUDIT_OBJ_LEV_LOW) ? 3214 &ctxt->range.level[0] : &ctxt->range.level[1]); 3215 switch (op) { 3216 case Audit_equal: 3217 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3218 level); 3219 break; 3220 case Audit_not_equal: 3221 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3222 level); 3223 break; 3224 case Audit_lt: 3225 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3226 level) && 3227 !mls_level_eq(&rule->au_ctxt.range.level[0], 3228 level)); 3229 break; 3230 case Audit_le: 3231 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3232 level); 3233 break; 3234 case Audit_gt: 3235 match = (mls_level_dom(level, 3236 &rule->au_ctxt.range.level[0]) && 3237 !mls_level_eq(level, 3238 &rule->au_ctxt.range.level[0])); 3239 break; 3240 case Audit_ge: 3241 match = mls_level_dom(level, 3242 &rule->au_ctxt.range.level[0]); 3243 break; 3244 } 3245 } 3246 3247 out: 3248 read_unlock(&policy_rwlock); 3249 return match; 3250 } 3251 3252 static int (*aurule_callback)(void) = audit_update_lsm_rules; 3253 3254 static int aurule_avc_callback(u32 event) 3255 { 3256 int err = 0; 3257 3258 if (event == AVC_CALLBACK_RESET && aurule_callback) 3259 err = aurule_callback(); 3260 return err; 3261 } 3262 3263 static int __init aurule_init(void) 3264 { 3265 int err; 3266 3267 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3268 if (err) 3269 panic("avc_add_callback() failed, error %d\n", err); 3270 3271 return err; 3272 } 3273 __initcall(aurule_init); 3274 3275 #ifdef CONFIG_NETLABEL 3276 /** 3277 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3278 * @secattr: the NetLabel packet security attributes 3279 * @sid: the SELinux SID 3280 * 3281 * Description: 3282 * Attempt to cache the context in @ctx, which was derived from the packet in 3283 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3284 * already been initialized. 3285 * 3286 */ 3287 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3288 u32 sid) 3289 { 3290 u32 *sid_cache; 3291 3292 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3293 if (sid_cache == NULL) 3294 return; 3295 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3296 if (secattr->cache == NULL) { 3297 kfree(sid_cache); 3298 return; 3299 } 3300 3301 *sid_cache = sid; 3302 secattr->cache->free = kfree; 3303 secattr->cache->data = sid_cache; 3304 secattr->flags |= NETLBL_SECATTR_CACHE; 3305 } 3306 3307 /** 3308 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3309 * @secattr: the NetLabel packet security attributes 3310 * @sid: the SELinux SID 3311 * 3312 * Description: 3313 * Convert the given NetLabel security attributes in @secattr into a 3314 * SELinux SID. If the @secattr field does not contain a full SELinux 3315 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3316 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3317 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3318 * conversion for future lookups. Returns zero on success, negative values on 3319 * failure. 3320 * 3321 */ 3322 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3323 u32 *sid) 3324 { 3325 int rc; 3326 struct context *ctx; 3327 struct context ctx_new; 3328 3329 if (!ss_initialized) { 3330 *sid = SECSID_NULL; 3331 return 0; 3332 } 3333 3334 read_lock(&policy_rwlock); 3335 3336 if (secattr->flags & NETLBL_SECATTR_CACHE) 3337 *sid = *(u32 *)secattr->cache->data; 3338 else if (secattr->flags & NETLBL_SECATTR_SECID) 3339 *sid = secattr->attr.secid; 3340 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3341 rc = -EIDRM; 3342 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG); 3343 if (ctx == NULL) 3344 goto out; 3345 3346 context_init(&ctx_new); 3347 ctx_new.user = ctx->user; 3348 ctx_new.role = ctx->role; 3349 ctx_new.type = ctx->type; 3350 mls_import_netlbl_lvl(&ctx_new, secattr); 3351 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3352 rc = mls_import_netlbl_cat(&ctx_new, secattr); 3353 if (rc) 3354 goto out; 3355 } 3356 rc = -EIDRM; 3357 if (!mls_context_isvalid(&policydb, &ctx_new)) 3358 goto out_free; 3359 3360 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); 3361 if (rc) 3362 goto out_free; 3363 3364 security_netlbl_cache_add(secattr, *sid); 3365 3366 ebitmap_destroy(&ctx_new.range.level[0].cat); 3367 } else 3368 *sid = SECSID_NULL; 3369 3370 read_unlock(&policy_rwlock); 3371 return 0; 3372 out_free: 3373 ebitmap_destroy(&ctx_new.range.level[0].cat); 3374 out: 3375 read_unlock(&policy_rwlock); 3376 return rc; 3377 } 3378 3379 /** 3380 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3381 * @sid: the SELinux SID 3382 * @secattr: the NetLabel packet security attributes 3383 * 3384 * Description: 3385 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3386 * Returns zero on success, negative values on failure. 3387 * 3388 */ 3389 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3390 { 3391 int rc; 3392 struct context *ctx; 3393 3394 if (!ss_initialized) 3395 return 0; 3396 3397 read_lock(&policy_rwlock); 3398 3399 rc = -ENOENT; 3400 ctx = sidtab_search(&sidtab, sid); 3401 if (ctx == NULL) 3402 goto out; 3403 3404 rc = -ENOMEM; 3405 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1), 3406 GFP_ATOMIC); 3407 if (secattr->domain == NULL) 3408 goto out; 3409 3410 secattr->attr.secid = sid; 3411 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3412 mls_export_netlbl_lvl(ctx, secattr); 3413 rc = mls_export_netlbl_cat(ctx, secattr); 3414 out: 3415 read_unlock(&policy_rwlock); 3416 return rc; 3417 } 3418 #endif /* CONFIG_NETLABEL */ 3419 3420 /** 3421 * security_read_policy - read the policy. 3422 * @data: binary policy data 3423 * @len: length of data in bytes 3424 * 3425 */ 3426 int security_read_policy(void **data, size_t *len) 3427 { 3428 int rc; 3429 struct policy_file fp; 3430 3431 if (!ss_initialized) 3432 return -EINVAL; 3433 3434 *len = security_policydb_len(); 3435 3436 *data = vmalloc_user(*len); 3437 if (!*data) 3438 return -ENOMEM; 3439 3440 fp.data = *data; 3441 fp.len = *len; 3442 3443 read_lock(&policy_rwlock); 3444 rc = policydb_write(&policydb, &fp); 3445 read_unlock(&policy_rwlock); 3446 3447 if (rc) 3448 return rc; 3449 3450 *len = (unsigned long)fp.data - (unsigned long)*data; 3451 return 0; 3452 3453 } 3454