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; 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 target = flex_array_get_ptr(policydb.type_val_to_struct_array, 557 tcontext->type - 1); 558 BUG_ON(!target); 559 560 if (source->bounds) { 561 memset(&lo_avd, 0, sizeof(lo_avd)); 562 563 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 564 lo_scontext.type = source->bounds; 565 566 context_struct_compute_av(&lo_scontext, 567 tcontext, 568 tclass, 569 &lo_avd, 570 NULL); 571 if ((lo_avd.allowed & avd->allowed) == avd->allowed) 572 return; /* no masked permission */ 573 masked = ~lo_avd.allowed & avd->allowed; 574 } 575 576 if (target->bounds) { 577 memset(&lo_avd, 0, sizeof(lo_avd)); 578 579 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 580 lo_tcontext.type = target->bounds; 581 582 context_struct_compute_av(scontext, 583 &lo_tcontext, 584 tclass, 585 &lo_avd, 586 NULL); 587 if ((lo_avd.allowed & avd->allowed) == avd->allowed) 588 return; /* no masked permission */ 589 masked = ~lo_avd.allowed & avd->allowed; 590 } 591 592 if (source->bounds && target->bounds) { 593 memset(&lo_avd, 0, sizeof(lo_avd)); 594 /* 595 * lo_scontext and lo_tcontext are already 596 * set up. 597 */ 598 599 context_struct_compute_av(&lo_scontext, 600 &lo_tcontext, 601 tclass, 602 &lo_avd, 603 NULL); 604 if ((lo_avd.allowed & avd->allowed) == avd->allowed) 605 return; /* no masked permission */ 606 masked = ~lo_avd.allowed & avd->allowed; 607 } 608 609 if (masked) { 610 /* mask violated permissions */ 611 avd->allowed &= ~masked; 612 613 /* audit masked permissions */ 614 security_dump_masked_av(scontext, tcontext, 615 tclass, masked, "bounds"); 616 } 617 } 618 619 /* 620 * flag which drivers have permissions 621 * only looking for ioctl based extended permssions 622 */ 623 void services_compute_xperms_drivers( 624 struct extended_perms *xperms, 625 struct avtab_node *node) 626 { 627 unsigned int i; 628 629 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 630 /* if one or more driver has all permissions allowed */ 631 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 632 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 633 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 634 /* if allowing permissions within a driver */ 635 security_xperm_set(xperms->drivers.p, 636 node->datum.u.xperms->driver); 637 } 638 639 /* If no ioctl commands are allowed, ignore auditallow and auditdeny */ 640 if (node->key.specified & AVTAB_XPERMS_ALLOWED) 641 xperms->len = 1; 642 } 643 644 /* 645 * Compute access vectors and extended permissions based on a context 646 * structure pair for the permissions in a particular class. 647 */ 648 static void context_struct_compute_av(struct context *scontext, 649 struct context *tcontext, 650 u16 tclass, 651 struct av_decision *avd, 652 struct extended_perms *xperms) 653 { 654 struct constraint_node *constraint; 655 struct role_allow *ra; 656 struct avtab_key avkey; 657 struct avtab_node *node; 658 struct class_datum *tclass_datum; 659 struct ebitmap *sattr, *tattr; 660 struct ebitmap_node *snode, *tnode; 661 unsigned int i, j; 662 663 avd->allowed = 0; 664 avd->auditallow = 0; 665 avd->auditdeny = 0xffffffff; 666 if (xperms) { 667 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 668 xperms->len = 0; 669 } 670 671 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 672 if (printk_ratelimit()) 673 printk(KERN_WARNING "SELinux: Invalid class %hu\n", tclass); 674 return; 675 } 676 677 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 678 679 /* 680 * If a specific type enforcement rule was defined for 681 * this permission check, then use it. 682 */ 683 avkey.target_class = tclass; 684 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 685 sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1); 686 BUG_ON(!sattr); 687 tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1); 688 BUG_ON(!tattr); 689 ebitmap_for_each_positive_bit(sattr, snode, i) { 690 ebitmap_for_each_positive_bit(tattr, tnode, j) { 691 avkey.source_type = i + 1; 692 avkey.target_type = j + 1; 693 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 694 node; 695 node = avtab_search_node_next(node, avkey.specified)) { 696 if (node->key.specified == AVTAB_ALLOWED) 697 avd->allowed |= node->datum.u.data; 698 else if (node->key.specified == AVTAB_AUDITALLOW) 699 avd->auditallow |= node->datum.u.data; 700 else if (node->key.specified == AVTAB_AUDITDENY) 701 avd->auditdeny &= node->datum.u.data; 702 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 703 services_compute_xperms_drivers(xperms, node); 704 } 705 706 /* Check conditional av table for additional permissions */ 707 cond_compute_av(&policydb.te_cond_avtab, &avkey, 708 avd, xperms); 709 710 } 711 } 712 713 /* 714 * Remove any permissions prohibited by a constraint (this includes 715 * the MLS policy). 716 */ 717 constraint = tclass_datum->constraints; 718 while (constraint) { 719 if ((constraint->permissions & (avd->allowed)) && 720 !constraint_expr_eval(scontext, tcontext, NULL, 721 constraint->expr)) { 722 avd->allowed &= ~(constraint->permissions); 723 } 724 constraint = constraint->next; 725 } 726 727 /* 728 * If checking process transition permission and the 729 * role is changing, then check the (current_role, new_role) 730 * pair. 731 */ 732 if (tclass == policydb.process_class && 733 (avd->allowed & policydb.process_trans_perms) && 734 scontext->role != tcontext->role) { 735 for (ra = policydb.role_allow; ra; ra = ra->next) { 736 if (scontext->role == ra->role && 737 tcontext->role == ra->new_role) 738 break; 739 } 740 if (!ra) 741 avd->allowed &= ~policydb.process_trans_perms; 742 } 743 744 /* 745 * If the given source and target types have boundary 746 * constraint, lazy checks have to mask any violated 747 * permission and notice it to userspace via audit. 748 */ 749 type_attribute_bounds_av(scontext, tcontext, 750 tclass, avd); 751 } 752 753 static int security_validtrans_handle_fail(struct context *ocontext, 754 struct context *ncontext, 755 struct context *tcontext, 756 u16 tclass) 757 { 758 char *o = NULL, *n = NULL, *t = NULL; 759 u32 olen, nlen, tlen; 760 761 if (context_struct_to_string(ocontext, &o, &olen)) 762 goto out; 763 if (context_struct_to_string(ncontext, &n, &nlen)) 764 goto out; 765 if (context_struct_to_string(tcontext, &t, &tlen)) 766 goto out; 767 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 768 "op=security_validate_transition seresult=denied" 769 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 770 o, n, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 771 out: 772 kfree(o); 773 kfree(n); 774 kfree(t); 775 776 if (!selinux_enforcing) 777 return 0; 778 return -EPERM; 779 } 780 781 static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid, 782 u16 orig_tclass, bool user) 783 { 784 struct context *ocontext; 785 struct context *ncontext; 786 struct context *tcontext; 787 struct class_datum *tclass_datum; 788 struct constraint_node *constraint; 789 u16 tclass; 790 int rc = 0; 791 792 if (!ss_initialized) 793 return 0; 794 795 read_lock(&policy_rwlock); 796 797 if (!user) 798 tclass = unmap_class(orig_tclass); 799 else 800 tclass = orig_tclass; 801 802 if (!tclass || tclass > policydb.p_classes.nprim) { 803 rc = -EINVAL; 804 goto out; 805 } 806 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 807 808 ocontext = sidtab_search(&sidtab, oldsid); 809 if (!ocontext) { 810 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 811 __func__, oldsid); 812 rc = -EINVAL; 813 goto out; 814 } 815 816 ncontext = sidtab_search(&sidtab, newsid); 817 if (!ncontext) { 818 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 819 __func__, newsid); 820 rc = -EINVAL; 821 goto out; 822 } 823 824 tcontext = sidtab_search(&sidtab, tasksid); 825 if (!tcontext) { 826 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 827 __func__, tasksid); 828 rc = -EINVAL; 829 goto out; 830 } 831 832 constraint = tclass_datum->validatetrans; 833 while (constraint) { 834 if (!constraint_expr_eval(ocontext, ncontext, tcontext, 835 constraint->expr)) { 836 if (user) 837 rc = -EPERM; 838 else 839 rc = security_validtrans_handle_fail(ocontext, 840 ncontext, 841 tcontext, 842 tclass); 843 goto out; 844 } 845 constraint = constraint->next; 846 } 847 848 out: 849 read_unlock(&policy_rwlock); 850 return rc; 851 } 852 853 int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, 854 u16 tclass) 855 { 856 return security_compute_validatetrans(oldsid, newsid, tasksid, 857 tclass, true); 858 } 859 860 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 861 u16 orig_tclass) 862 { 863 return security_compute_validatetrans(oldsid, newsid, tasksid, 864 orig_tclass, false); 865 } 866 867 /* 868 * security_bounded_transition - check whether the given 869 * transition is directed to bounded, or not. 870 * It returns 0, if @newsid is bounded by @oldsid. 871 * Otherwise, it returns error code. 872 * 873 * @oldsid : current security identifier 874 * @newsid : destinated security identifier 875 */ 876 int security_bounded_transition(u32 old_sid, u32 new_sid) 877 { 878 struct context *old_context, *new_context; 879 struct type_datum *type; 880 int index; 881 int rc; 882 883 read_lock(&policy_rwlock); 884 885 rc = -EINVAL; 886 old_context = sidtab_search(&sidtab, old_sid); 887 if (!old_context) { 888 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 889 __func__, old_sid); 890 goto out; 891 } 892 893 rc = -EINVAL; 894 new_context = sidtab_search(&sidtab, new_sid); 895 if (!new_context) { 896 printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", 897 __func__, new_sid); 898 goto out; 899 } 900 901 rc = 0; 902 /* type/domain unchanged */ 903 if (old_context->type == new_context->type) 904 goto out; 905 906 index = new_context->type; 907 while (true) { 908 type = flex_array_get_ptr(policydb.type_val_to_struct_array, 909 index - 1); 910 BUG_ON(!type); 911 912 /* not bounded anymore */ 913 rc = -EPERM; 914 if (!type->bounds) 915 break; 916 917 /* @newsid is bounded by @oldsid */ 918 rc = 0; 919 if (type->bounds == old_context->type) 920 break; 921 922 index = type->bounds; 923 } 924 925 if (rc) { 926 char *old_name = NULL; 927 char *new_name = NULL; 928 u32 length; 929 930 if (!context_struct_to_string(old_context, 931 &old_name, &length) && 932 !context_struct_to_string(new_context, 933 &new_name, &length)) { 934 audit_log(current->audit_context, 935 GFP_ATOMIC, AUDIT_SELINUX_ERR, 936 "op=security_bounded_transition " 937 "seresult=denied " 938 "oldcontext=%s newcontext=%s", 939 old_name, new_name); 940 } 941 kfree(new_name); 942 kfree(old_name); 943 } 944 out: 945 read_unlock(&policy_rwlock); 946 947 return rc; 948 } 949 950 static void avd_init(struct av_decision *avd) 951 { 952 avd->allowed = 0; 953 avd->auditallow = 0; 954 avd->auditdeny = 0xffffffff; 955 avd->seqno = latest_granting; 956 avd->flags = 0; 957 } 958 959 void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 960 struct avtab_node *node) 961 { 962 unsigned int i; 963 964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 965 if (xpermd->driver != node->datum.u.xperms->driver) 966 return; 967 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 968 if (!security_xperm_test(node->datum.u.xperms->perms.p, 969 xpermd->driver)) 970 return; 971 } else { 972 BUG(); 973 } 974 975 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 976 xpermd->used |= XPERMS_ALLOWED; 977 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 978 memset(xpermd->allowed->p, 0xff, 979 sizeof(xpermd->allowed->p)); 980 } 981 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 982 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 983 xpermd->allowed->p[i] |= 984 node->datum.u.xperms->perms.p[i]; 985 } 986 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 987 xpermd->used |= XPERMS_AUDITALLOW; 988 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 989 memset(xpermd->auditallow->p, 0xff, 990 sizeof(xpermd->auditallow->p)); 991 } 992 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 993 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 994 xpermd->auditallow->p[i] |= 995 node->datum.u.xperms->perms.p[i]; 996 } 997 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 998 xpermd->used |= XPERMS_DONTAUDIT; 999 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 1000 memset(xpermd->dontaudit->p, 0xff, 1001 sizeof(xpermd->dontaudit->p)); 1002 } 1003 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 1004 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 1005 xpermd->dontaudit->p[i] |= 1006 node->datum.u.xperms->perms.p[i]; 1007 } 1008 } else { 1009 BUG(); 1010 } 1011 } 1012 1013 void security_compute_xperms_decision(u32 ssid, 1014 u32 tsid, 1015 u16 orig_tclass, 1016 u8 driver, 1017 struct extended_perms_decision *xpermd) 1018 { 1019 u16 tclass; 1020 struct context *scontext, *tcontext; 1021 struct avtab_key avkey; 1022 struct avtab_node *node; 1023 struct ebitmap *sattr, *tattr; 1024 struct ebitmap_node *snode, *tnode; 1025 unsigned int i, j; 1026 1027 xpermd->driver = driver; 1028 xpermd->used = 0; 1029 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1030 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1031 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1032 1033 read_lock(&policy_rwlock); 1034 if (!ss_initialized) 1035 goto allow; 1036 1037 scontext = sidtab_search(&sidtab, ssid); 1038 if (!scontext) { 1039 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1040 __func__, ssid); 1041 goto out; 1042 } 1043 1044 tcontext = sidtab_search(&sidtab, tsid); 1045 if (!tcontext) { 1046 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1047 __func__, tsid); 1048 goto out; 1049 } 1050 1051 tclass = unmap_class(orig_tclass); 1052 if (unlikely(orig_tclass && !tclass)) { 1053 if (policydb.allow_unknown) 1054 goto allow; 1055 goto out; 1056 } 1057 1058 1059 if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { 1060 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1061 goto out; 1062 } 1063 1064 avkey.target_class = tclass; 1065 avkey.specified = AVTAB_XPERMS; 1066 sattr = flex_array_get(policydb.type_attr_map_array, 1067 scontext->type - 1); 1068 BUG_ON(!sattr); 1069 tattr = flex_array_get(policydb.type_attr_map_array, 1070 tcontext->type - 1); 1071 BUG_ON(!tattr); 1072 ebitmap_for_each_positive_bit(sattr, snode, i) { 1073 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1074 avkey.source_type = i + 1; 1075 avkey.target_type = j + 1; 1076 for (node = avtab_search_node(&policydb.te_avtab, &avkey); 1077 node; 1078 node = avtab_search_node_next(node, avkey.specified)) 1079 services_compute_xperms_decision(xpermd, node); 1080 1081 cond_compute_xperms(&policydb.te_cond_avtab, 1082 &avkey, xpermd); 1083 } 1084 } 1085 out: 1086 read_unlock(&policy_rwlock); 1087 return; 1088 allow: 1089 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1090 goto out; 1091 } 1092 1093 /** 1094 * security_compute_av - Compute access vector decisions. 1095 * @ssid: source security identifier 1096 * @tsid: target security identifier 1097 * @tclass: target security class 1098 * @avd: access vector decisions 1099 * @xperms: extended permissions 1100 * 1101 * Compute a set of access vector decisions based on the 1102 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1103 */ 1104 void security_compute_av(u32 ssid, 1105 u32 tsid, 1106 u16 orig_tclass, 1107 struct av_decision *avd, 1108 struct extended_perms *xperms) 1109 { 1110 u16 tclass; 1111 struct context *scontext = NULL, *tcontext = NULL; 1112 1113 read_lock(&policy_rwlock); 1114 avd_init(avd); 1115 xperms->len = 0; 1116 if (!ss_initialized) 1117 goto allow; 1118 1119 scontext = sidtab_search(&sidtab, ssid); 1120 if (!scontext) { 1121 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1122 __func__, ssid); 1123 goto out; 1124 } 1125 1126 /* permissive domain? */ 1127 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1128 avd->flags |= AVD_FLAGS_PERMISSIVE; 1129 1130 tcontext = sidtab_search(&sidtab, tsid); 1131 if (!tcontext) { 1132 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1133 __func__, tsid); 1134 goto out; 1135 } 1136 1137 tclass = unmap_class(orig_tclass); 1138 if (unlikely(orig_tclass && !tclass)) { 1139 if (policydb.allow_unknown) 1140 goto allow; 1141 goto out; 1142 } 1143 context_struct_compute_av(scontext, tcontext, tclass, avd, xperms); 1144 map_decision(orig_tclass, avd, policydb.allow_unknown); 1145 out: 1146 read_unlock(&policy_rwlock); 1147 return; 1148 allow: 1149 avd->allowed = 0xffffffff; 1150 goto out; 1151 } 1152 1153 void security_compute_av_user(u32 ssid, 1154 u32 tsid, 1155 u16 tclass, 1156 struct av_decision *avd) 1157 { 1158 struct context *scontext = NULL, *tcontext = NULL; 1159 1160 read_lock(&policy_rwlock); 1161 avd_init(avd); 1162 if (!ss_initialized) 1163 goto allow; 1164 1165 scontext = sidtab_search(&sidtab, ssid); 1166 if (!scontext) { 1167 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1168 __func__, ssid); 1169 goto out; 1170 } 1171 1172 /* permissive domain? */ 1173 if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) 1174 avd->flags |= AVD_FLAGS_PERMISSIVE; 1175 1176 tcontext = sidtab_search(&sidtab, tsid); 1177 if (!tcontext) { 1178 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1179 __func__, tsid); 1180 goto out; 1181 } 1182 1183 if (unlikely(!tclass)) { 1184 if (policydb.allow_unknown) 1185 goto allow; 1186 goto out; 1187 } 1188 1189 context_struct_compute_av(scontext, tcontext, tclass, avd, NULL); 1190 out: 1191 read_unlock(&policy_rwlock); 1192 return; 1193 allow: 1194 avd->allowed = 0xffffffff; 1195 goto out; 1196 } 1197 1198 /* 1199 * Write the security context string representation of 1200 * the context structure `context' into a dynamically 1201 * allocated string of the correct size. Set `*scontext' 1202 * to point to this string and set `*scontext_len' to 1203 * the length of the string. 1204 */ 1205 static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) 1206 { 1207 char *scontextp; 1208 1209 if (scontext) 1210 *scontext = NULL; 1211 *scontext_len = 0; 1212 1213 if (context->len) { 1214 *scontext_len = context->len; 1215 if (scontext) { 1216 *scontext = kstrdup(context->str, GFP_ATOMIC); 1217 if (!(*scontext)) 1218 return -ENOMEM; 1219 } 1220 return 0; 1221 } 1222 1223 /* Compute the size of the context. */ 1224 *scontext_len += strlen(sym_name(&policydb, SYM_USERS, context->user - 1)) + 1; 1225 *scontext_len += strlen(sym_name(&policydb, SYM_ROLES, context->role - 1)) + 1; 1226 *scontext_len += strlen(sym_name(&policydb, SYM_TYPES, context->type - 1)) + 1; 1227 *scontext_len += mls_compute_context_len(context); 1228 1229 if (!scontext) 1230 return 0; 1231 1232 /* Allocate space for the context; caller must free this space. */ 1233 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1234 if (!scontextp) 1235 return -ENOMEM; 1236 *scontext = scontextp; 1237 1238 /* 1239 * Copy the user name, role name and type name into the context. 1240 */ 1241 scontextp += sprintf(scontextp, "%s:%s:%s", 1242 sym_name(&policydb, SYM_USERS, context->user - 1), 1243 sym_name(&policydb, SYM_ROLES, context->role - 1), 1244 sym_name(&policydb, SYM_TYPES, context->type - 1)); 1245 1246 mls_sid_to_context(context, &scontextp); 1247 1248 *scontextp = 0; 1249 1250 return 0; 1251 } 1252 1253 #include "initial_sid_to_string.h" 1254 1255 const char *security_get_initial_sid_context(u32 sid) 1256 { 1257 if (unlikely(sid > SECINITSID_NUM)) 1258 return NULL; 1259 return initial_sid_to_string[sid]; 1260 } 1261 1262 static int security_sid_to_context_core(u32 sid, char **scontext, 1263 u32 *scontext_len, int force) 1264 { 1265 struct context *context; 1266 int rc = 0; 1267 1268 if (scontext) 1269 *scontext = NULL; 1270 *scontext_len = 0; 1271 1272 if (!ss_initialized) { 1273 if (sid <= SECINITSID_NUM) { 1274 char *scontextp; 1275 1276 *scontext_len = strlen(initial_sid_to_string[sid]) + 1; 1277 if (!scontext) 1278 goto out; 1279 scontextp = kmemdup(initial_sid_to_string[sid], 1280 *scontext_len, GFP_ATOMIC); 1281 if (!scontextp) { 1282 rc = -ENOMEM; 1283 goto out; 1284 } 1285 *scontext = scontextp; 1286 goto out; 1287 } 1288 printk(KERN_ERR "SELinux: %s: called before initial " 1289 "load_policy on unknown SID %d\n", __func__, sid); 1290 rc = -EINVAL; 1291 goto out; 1292 } 1293 read_lock(&policy_rwlock); 1294 if (force) 1295 context = sidtab_search_force(&sidtab, sid); 1296 else 1297 context = sidtab_search(&sidtab, sid); 1298 if (!context) { 1299 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1300 __func__, sid); 1301 rc = -EINVAL; 1302 goto out_unlock; 1303 } 1304 rc = context_struct_to_string(context, scontext, scontext_len); 1305 out_unlock: 1306 read_unlock(&policy_rwlock); 1307 out: 1308 return rc; 1309 1310 } 1311 1312 /** 1313 * security_sid_to_context - Obtain a context for a given SID. 1314 * @sid: security identifier, SID 1315 * @scontext: security context 1316 * @scontext_len: length in bytes 1317 * 1318 * Write the string representation of the context associated with @sid 1319 * into a dynamically allocated string of the correct size. Set @scontext 1320 * to point to this string and set @scontext_len to the length of the string. 1321 */ 1322 int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1323 { 1324 return security_sid_to_context_core(sid, scontext, scontext_len, 0); 1325 } 1326 1327 int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len) 1328 { 1329 return security_sid_to_context_core(sid, scontext, scontext_len, 1); 1330 } 1331 1332 /* 1333 * Caveat: Mutates scontext. 1334 */ 1335 static int string_to_context_struct(struct policydb *pol, 1336 struct sidtab *sidtabp, 1337 char *scontext, 1338 u32 scontext_len, 1339 struct context *ctx, 1340 u32 def_sid) 1341 { 1342 struct role_datum *role; 1343 struct type_datum *typdatum; 1344 struct user_datum *usrdatum; 1345 char *scontextp, *p, oldc; 1346 int rc = 0; 1347 1348 context_init(ctx); 1349 1350 /* Parse the security context. */ 1351 1352 rc = -EINVAL; 1353 scontextp = (char *) scontext; 1354 1355 /* Extract the user. */ 1356 p = scontextp; 1357 while (*p && *p != ':') 1358 p++; 1359 1360 if (*p == 0) 1361 goto out; 1362 1363 *p++ = 0; 1364 1365 usrdatum = hashtab_search(pol->p_users.table, scontextp); 1366 if (!usrdatum) 1367 goto out; 1368 1369 ctx->user = usrdatum->value; 1370 1371 /* Extract role. */ 1372 scontextp = p; 1373 while (*p && *p != ':') 1374 p++; 1375 1376 if (*p == 0) 1377 goto out; 1378 1379 *p++ = 0; 1380 1381 role = hashtab_search(pol->p_roles.table, scontextp); 1382 if (!role) 1383 goto out; 1384 ctx->role = role->value; 1385 1386 /* Extract type. */ 1387 scontextp = p; 1388 while (*p && *p != ':') 1389 p++; 1390 oldc = *p; 1391 *p++ = 0; 1392 1393 typdatum = hashtab_search(pol->p_types.table, scontextp); 1394 if (!typdatum || typdatum->attribute) 1395 goto out; 1396 1397 ctx->type = typdatum->value; 1398 1399 rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid); 1400 if (rc) 1401 goto out; 1402 1403 rc = -EINVAL; 1404 if ((p - scontext) < scontext_len) 1405 goto out; 1406 1407 /* Check the validity of the new context. */ 1408 if (!policydb_context_isvalid(pol, ctx)) 1409 goto out; 1410 rc = 0; 1411 out: 1412 if (rc) 1413 context_destroy(ctx); 1414 return rc; 1415 } 1416 1417 static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1418 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1419 int force) 1420 { 1421 char *scontext2, *str = NULL; 1422 struct context context; 1423 int rc = 0; 1424 1425 /* An empty security context is never valid. */ 1426 if (!scontext_len) 1427 return -EINVAL; 1428 1429 if (!ss_initialized) { 1430 int i; 1431 1432 for (i = 1; i < SECINITSID_NUM; i++) { 1433 if (!strcmp(initial_sid_to_string[i], scontext)) { 1434 *sid = i; 1435 return 0; 1436 } 1437 } 1438 *sid = SECINITSID_KERNEL; 1439 return 0; 1440 } 1441 *sid = SECSID_NULL; 1442 1443 /* Copy the string so that we can modify the copy as we parse it. */ 1444 scontext2 = kmalloc(scontext_len + 1, gfp_flags); 1445 if (!scontext2) 1446 return -ENOMEM; 1447 memcpy(scontext2, scontext, scontext_len); 1448 scontext2[scontext_len] = 0; 1449 1450 if (force) { 1451 /* Save another copy for storing in uninterpreted form */ 1452 rc = -ENOMEM; 1453 str = kstrdup(scontext2, gfp_flags); 1454 if (!str) 1455 goto out; 1456 } 1457 1458 read_lock(&policy_rwlock); 1459 rc = string_to_context_struct(&policydb, &sidtab, scontext2, 1460 scontext_len, &context, def_sid); 1461 if (rc == -EINVAL && force) { 1462 context.str = str; 1463 context.len = scontext_len; 1464 str = NULL; 1465 } else if (rc) 1466 goto out_unlock; 1467 rc = sidtab_context_to_sid(&sidtab, &context, sid); 1468 context_destroy(&context); 1469 out_unlock: 1470 read_unlock(&policy_rwlock); 1471 out: 1472 kfree(scontext2); 1473 kfree(str); 1474 return rc; 1475 } 1476 1477 /** 1478 * security_context_to_sid - Obtain a SID for a given security context. 1479 * @scontext: security context 1480 * @scontext_len: length in bytes 1481 * @sid: security identifier, SID 1482 * @gfp: context for the allocation 1483 * 1484 * Obtains a SID associated with the security context that 1485 * has the string representation specified by @scontext. 1486 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1487 * memory is available, or 0 on success. 1488 */ 1489 int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1490 gfp_t gfp) 1491 { 1492 return security_context_to_sid_core(scontext, scontext_len, 1493 sid, SECSID_NULL, gfp, 0); 1494 } 1495 1496 int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1497 { 1498 return security_context_to_sid(scontext, strlen(scontext), sid, gfp); 1499 } 1500 1501 /** 1502 * security_context_to_sid_default - Obtain a SID for a given security context, 1503 * falling back to specified default if needed. 1504 * 1505 * @scontext: security context 1506 * @scontext_len: length in bytes 1507 * @sid: security identifier, SID 1508 * @def_sid: default SID to assign on error 1509 * 1510 * Obtains a SID associated with the security context that 1511 * has the string representation specified by @scontext. 1512 * The default SID is passed to the MLS layer to be used to allow 1513 * kernel labeling of the MLS field if the MLS field is not present 1514 * (for upgrading to MLS without full relabel). 1515 * Implicitly forces adding of the context even if it cannot be mapped yet. 1516 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1517 * memory is available, or 0 on success. 1518 */ 1519 int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1520 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1521 { 1522 return security_context_to_sid_core(scontext, scontext_len, 1523 sid, def_sid, gfp_flags, 1); 1524 } 1525 1526 int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1527 u32 *sid) 1528 { 1529 return security_context_to_sid_core(scontext, scontext_len, 1530 sid, SECSID_NULL, GFP_KERNEL, 1); 1531 } 1532 1533 static int compute_sid_handle_invalid_context( 1534 struct context *scontext, 1535 struct context *tcontext, 1536 u16 tclass, 1537 struct context *newcontext) 1538 { 1539 char *s = NULL, *t = NULL, *n = NULL; 1540 u32 slen, tlen, nlen; 1541 1542 if (context_struct_to_string(scontext, &s, &slen)) 1543 goto out; 1544 if (context_struct_to_string(tcontext, &t, &tlen)) 1545 goto out; 1546 if (context_struct_to_string(newcontext, &n, &nlen)) 1547 goto out; 1548 audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, 1549 "op=security_compute_sid invalid_context=%s" 1550 " scontext=%s" 1551 " tcontext=%s" 1552 " tclass=%s", 1553 n, s, t, sym_name(&policydb, SYM_CLASSES, tclass-1)); 1554 out: 1555 kfree(s); 1556 kfree(t); 1557 kfree(n); 1558 if (!selinux_enforcing) 1559 return 0; 1560 return -EACCES; 1561 } 1562 1563 static void filename_compute_type(struct policydb *p, struct context *newcontext, 1564 u32 stype, u32 ttype, u16 tclass, 1565 const char *objname) 1566 { 1567 struct filename_trans ft; 1568 struct filename_trans_datum *otype; 1569 1570 /* 1571 * Most filename trans rules are going to live in specific directories 1572 * like /dev or /var/run. This bitmap will quickly skip rule searches 1573 * if the ttype does not contain any rules. 1574 */ 1575 if (!ebitmap_get_bit(&p->filename_trans_ttypes, ttype)) 1576 return; 1577 1578 ft.stype = stype; 1579 ft.ttype = ttype; 1580 ft.tclass = tclass; 1581 ft.name = objname; 1582 1583 otype = hashtab_search(p->filename_trans, &ft); 1584 if (otype) 1585 newcontext->type = otype->otype; 1586 } 1587 1588 static int security_compute_sid(u32 ssid, 1589 u32 tsid, 1590 u16 orig_tclass, 1591 u32 specified, 1592 const char *objname, 1593 u32 *out_sid, 1594 bool kern) 1595 { 1596 struct class_datum *cladatum = NULL; 1597 struct context *scontext = NULL, *tcontext = NULL, newcontext; 1598 struct role_trans *roletr = NULL; 1599 struct avtab_key avkey; 1600 struct avtab_datum *avdatum; 1601 struct avtab_node *node; 1602 u16 tclass; 1603 int rc = 0; 1604 bool sock; 1605 1606 if (!ss_initialized) { 1607 switch (orig_tclass) { 1608 case SECCLASS_PROCESS: /* kernel value */ 1609 *out_sid = ssid; 1610 break; 1611 default: 1612 *out_sid = tsid; 1613 break; 1614 } 1615 goto out; 1616 } 1617 1618 context_init(&newcontext); 1619 1620 read_lock(&policy_rwlock); 1621 1622 if (kern) { 1623 tclass = unmap_class(orig_tclass); 1624 sock = security_is_socket_class(orig_tclass); 1625 } else { 1626 tclass = orig_tclass; 1627 sock = security_is_socket_class(map_class(tclass)); 1628 } 1629 1630 scontext = sidtab_search(&sidtab, ssid); 1631 if (!scontext) { 1632 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1633 __func__, ssid); 1634 rc = -EINVAL; 1635 goto out_unlock; 1636 } 1637 tcontext = sidtab_search(&sidtab, tsid); 1638 if (!tcontext) { 1639 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 1640 __func__, tsid); 1641 rc = -EINVAL; 1642 goto out_unlock; 1643 } 1644 1645 if (tclass && tclass <= policydb.p_classes.nprim) 1646 cladatum = policydb.class_val_to_struct[tclass - 1]; 1647 1648 /* Set the user identity. */ 1649 switch (specified) { 1650 case AVTAB_TRANSITION: 1651 case AVTAB_CHANGE: 1652 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1653 newcontext.user = tcontext->user; 1654 } else { 1655 /* notice this gets both DEFAULT_SOURCE and unset */ 1656 /* Use the process user identity. */ 1657 newcontext.user = scontext->user; 1658 } 1659 break; 1660 case AVTAB_MEMBER: 1661 /* Use the related object owner. */ 1662 newcontext.user = tcontext->user; 1663 break; 1664 } 1665 1666 /* Set the role to default values. */ 1667 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1668 newcontext.role = scontext->role; 1669 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1670 newcontext.role = tcontext->role; 1671 } else { 1672 if ((tclass == policydb.process_class) || (sock == true)) 1673 newcontext.role = scontext->role; 1674 else 1675 newcontext.role = OBJECT_R_VAL; 1676 } 1677 1678 /* Set the type to default values. */ 1679 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1680 newcontext.type = scontext->type; 1681 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1682 newcontext.type = tcontext->type; 1683 } else { 1684 if ((tclass == policydb.process_class) || (sock == true)) { 1685 /* Use the type of process. */ 1686 newcontext.type = scontext->type; 1687 } else { 1688 /* Use the type of the related object. */ 1689 newcontext.type = tcontext->type; 1690 } 1691 } 1692 1693 /* Look for a type transition/member/change rule. */ 1694 avkey.source_type = scontext->type; 1695 avkey.target_type = tcontext->type; 1696 avkey.target_class = tclass; 1697 avkey.specified = specified; 1698 avdatum = avtab_search(&policydb.te_avtab, &avkey); 1699 1700 /* If no permanent rule, also check for enabled conditional rules */ 1701 if (!avdatum) { 1702 node = avtab_search_node(&policydb.te_cond_avtab, &avkey); 1703 for (; node; node = avtab_search_node_next(node, specified)) { 1704 if (node->key.specified & AVTAB_ENABLED) { 1705 avdatum = &node->datum; 1706 break; 1707 } 1708 } 1709 } 1710 1711 if (avdatum) { 1712 /* Use the type from the type transition/member/change rule. */ 1713 newcontext.type = avdatum->u.data; 1714 } 1715 1716 /* if we have a objname this is a file trans check so check those rules */ 1717 if (objname) 1718 filename_compute_type(&policydb, &newcontext, scontext->type, 1719 tcontext->type, tclass, objname); 1720 1721 /* Check for class-specific changes. */ 1722 if (specified & AVTAB_TRANSITION) { 1723 /* Look for a role transition rule. */ 1724 for (roletr = policydb.role_tr; roletr; roletr = roletr->next) { 1725 if ((roletr->role == scontext->role) && 1726 (roletr->type == tcontext->type) && 1727 (roletr->tclass == tclass)) { 1728 /* Use the role transition rule. */ 1729 newcontext.role = roletr->new_role; 1730 break; 1731 } 1732 } 1733 } 1734 1735 /* Set the MLS attributes. 1736 This is done last because it may allocate memory. */ 1737 rc = mls_compute_sid(scontext, tcontext, tclass, specified, 1738 &newcontext, sock); 1739 if (rc) 1740 goto out_unlock; 1741 1742 /* Check the validity of the context. */ 1743 if (!policydb_context_isvalid(&policydb, &newcontext)) { 1744 rc = compute_sid_handle_invalid_context(scontext, 1745 tcontext, 1746 tclass, 1747 &newcontext); 1748 if (rc) 1749 goto out_unlock; 1750 } 1751 /* Obtain the sid for the context. */ 1752 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); 1753 out_unlock: 1754 read_unlock(&policy_rwlock); 1755 context_destroy(&newcontext); 1756 out: 1757 return rc; 1758 } 1759 1760 /** 1761 * security_transition_sid - Compute the SID for a new subject/object. 1762 * @ssid: source security identifier 1763 * @tsid: target security identifier 1764 * @tclass: target security class 1765 * @out_sid: security identifier for new subject/object 1766 * 1767 * Compute a SID to use for labeling a new subject or object in the 1768 * class @tclass based on a SID pair (@ssid, @tsid). 1769 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1770 * if insufficient memory is available, or %0 if the new SID was 1771 * computed successfully. 1772 */ 1773 int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1774 const struct qstr *qstr, u32 *out_sid) 1775 { 1776 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1777 qstr ? qstr->name : NULL, out_sid, true); 1778 } 1779 1780 int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1781 const char *objname, u32 *out_sid) 1782 { 1783 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, 1784 objname, out_sid, false); 1785 } 1786 1787 /** 1788 * security_member_sid - Compute the SID for member selection. 1789 * @ssid: source security identifier 1790 * @tsid: target security identifier 1791 * @tclass: target security class 1792 * @out_sid: security identifier for selected member 1793 * 1794 * Compute a SID to use when selecting a member of a polyinstantiated 1795 * object of class @tclass based on a SID pair (@ssid, @tsid). 1796 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1797 * if insufficient memory is available, or %0 if the SID was 1798 * computed successfully. 1799 */ 1800 int security_member_sid(u32 ssid, 1801 u32 tsid, 1802 u16 tclass, 1803 u32 *out_sid) 1804 { 1805 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL, 1806 out_sid, false); 1807 } 1808 1809 /** 1810 * security_change_sid - Compute the SID for object relabeling. 1811 * @ssid: source security identifier 1812 * @tsid: target security identifier 1813 * @tclass: target security class 1814 * @out_sid: security identifier for selected member 1815 * 1816 * Compute a SID to use for relabeling an object of class @tclass 1817 * based on a SID pair (@ssid, @tsid). 1818 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1819 * if insufficient memory is available, or %0 if the SID was 1820 * computed successfully. 1821 */ 1822 int security_change_sid(u32 ssid, 1823 u32 tsid, 1824 u16 tclass, 1825 u32 *out_sid) 1826 { 1827 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1828 out_sid, false); 1829 } 1830 1831 /* Clone the SID into the new SID table. */ 1832 static int clone_sid(u32 sid, 1833 struct context *context, 1834 void *arg) 1835 { 1836 struct sidtab *s = arg; 1837 1838 if (sid > SECINITSID_NUM) 1839 return sidtab_insert(s, sid, context); 1840 else 1841 return 0; 1842 } 1843 1844 static inline int convert_context_handle_invalid_context(struct context *context) 1845 { 1846 char *s; 1847 u32 len; 1848 1849 if (selinux_enforcing) 1850 return -EINVAL; 1851 1852 if (!context_struct_to_string(context, &s, &len)) { 1853 printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s); 1854 kfree(s); 1855 } 1856 return 0; 1857 } 1858 1859 struct convert_context_args { 1860 struct policydb *oldp; 1861 struct policydb *newp; 1862 }; 1863 1864 /* 1865 * Convert the values in the security context 1866 * structure `c' from the values specified 1867 * in the policy `p->oldp' to the values specified 1868 * in the policy `p->newp'. Verify that the 1869 * context is valid under the new policy. 1870 */ 1871 static int convert_context(u32 key, 1872 struct context *c, 1873 void *p) 1874 { 1875 struct convert_context_args *args; 1876 struct context oldc; 1877 struct ocontext *oc; 1878 struct mls_range *range; 1879 struct role_datum *role; 1880 struct type_datum *typdatum; 1881 struct user_datum *usrdatum; 1882 char *s; 1883 u32 len; 1884 int rc = 0; 1885 1886 if (key <= SECINITSID_NUM) 1887 goto out; 1888 1889 args = p; 1890 1891 if (c->str) { 1892 struct context ctx; 1893 1894 rc = -ENOMEM; 1895 s = kstrdup(c->str, GFP_KERNEL); 1896 if (!s) 1897 goto out; 1898 1899 rc = string_to_context_struct(args->newp, NULL, s, 1900 c->len, &ctx, SECSID_NULL); 1901 kfree(s); 1902 if (!rc) { 1903 printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n", 1904 c->str); 1905 /* Replace string with mapped representation. */ 1906 kfree(c->str); 1907 memcpy(c, &ctx, sizeof(*c)); 1908 goto out; 1909 } else if (rc == -EINVAL) { 1910 /* Retain string representation for later mapping. */ 1911 rc = 0; 1912 goto out; 1913 } else { 1914 /* Other error condition, e.g. ENOMEM. */ 1915 printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n", 1916 c->str, -rc); 1917 goto out; 1918 } 1919 } 1920 1921 rc = context_cpy(&oldc, c); 1922 if (rc) 1923 goto out; 1924 1925 /* Convert the user. */ 1926 rc = -EINVAL; 1927 usrdatum = hashtab_search(args->newp->p_users.table, 1928 sym_name(args->oldp, SYM_USERS, c->user - 1)); 1929 if (!usrdatum) 1930 goto bad; 1931 c->user = usrdatum->value; 1932 1933 /* Convert the role. */ 1934 rc = -EINVAL; 1935 role = hashtab_search(args->newp->p_roles.table, 1936 sym_name(args->oldp, SYM_ROLES, c->role - 1)); 1937 if (!role) 1938 goto bad; 1939 c->role = role->value; 1940 1941 /* Convert the type. */ 1942 rc = -EINVAL; 1943 typdatum = hashtab_search(args->newp->p_types.table, 1944 sym_name(args->oldp, SYM_TYPES, c->type - 1)); 1945 if (!typdatum) 1946 goto bad; 1947 c->type = typdatum->value; 1948 1949 /* Convert the MLS fields if dealing with MLS policies */ 1950 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 1951 rc = mls_convert_context(args->oldp, args->newp, c); 1952 if (rc) 1953 goto bad; 1954 } else if (args->oldp->mls_enabled && !args->newp->mls_enabled) { 1955 /* 1956 * Switching between MLS and non-MLS policy: 1957 * free any storage used by the MLS fields in the 1958 * context for all existing entries in the sidtab. 1959 */ 1960 mls_context_destroy(c); 1961 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 1962 /* 1963 * Switching between non-MLS and MLS policy: 1964 * ensure that the MLS fields of the context for all 1965 * existing entries in the sidtab are filled in with a 1966 * suitable default value, likely taken from one of the 1967 * initial SIDs. 1968 */ 1969 oc = args->newp->ocontexts[OCON_ISID]; 1970 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 1971 oc = oc->next; 1972 rc = -EINVAL; 1973 if (!oc) { 1974 printk(KERN_ERR "SELinux: unable to look up" 1975 " the initial SIDs list\n"); 1976 goto bad; 1977 } 1978 range = &oc->context[0].range; 1979 rc = mls_range_set(c, range); 1980 if (rc) 1981 goto bad; 1982 } 1983 1984 /* Check the validity of the new context. */ 1985 if (!policydb_context_isvalid(args->newp, c)) { 1986 rc = convert_context_handle_invalid_context(&oldc); 1987 if (rc) 1988 goto bad; 1989 } 1990 1991 context_destroy(&oldc); 1992 1993 rc = 0; 1994 out: 1995 return rc; 1996 bad: 1997 /* Map old representation to string and save it. */ 1998 rc = context_struct_to_string(&oldc, &s, &len); 1999 if (rc) 2000 return rc; 2001 context_destroy(&oldc); 2002 context_destroy(c); 2003 c->str = s; 2004 c->len = len; 2005 printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n", 2006 c->str); 2007 rc = 0; 2008 goto out; 2009 } 2010 2011 static void security_load_policycaps(void) 2012 { 2013 selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps, 2014 POLICYDB_CAPABILITY_NETPEER); 2015 selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps, 2016 POLICYDB_CAPABILITY_OPENPERM); 2017 selinux_policycap_alwaysnetwork = ebitmap_get_bit(&policydb.policycaps, 2018 POLICYDB_CAPABILITY_ALWAYSNETWORK); 2019 } 2020 2021 static int security_preserve_bools(struct policydb *p); 2022 2023 /** 2024 * security_load_policy - Load a security policy configuration. 2025 * @data: binary policy data 2026 * @len: length of data in bytes 2027 * 2028 * Load a new set of security policy configuration data, 2029 * validate it and convert the SID table as necessary. 2030 * This function will flush the access vector cache after 2031 * loading the new policy. 2032 */ 2033 int security_load_policy(void *data, size_t len) 2034 { 2035 struct policydb *oldpolicydb, *newpolicydb; 2036 struct sidtab oldsidtab, newsidtab; 2037 struct selinux_mapping *oldmap, *map = NULL; 2038 struct convert_context_args args; 2039 u32 seqno; 2040 u16 map_size; 2041 int rc = 0; 2042 struct policy_file file = { data, len }, *fp = &file; 2043 2044 oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL); 2045 if (!oldpolicydb) { 2046 rc = -ENOMEM; 2047 goto out; 2048 } 2049 newpolicydb = oldpolicydb + 1; 2050 2051 if (!ss_initialized) { 2052 avtab_cache_init(); 2053 rc = policydb_read(&policydb, fp); 2054 if (rc) { 2055 avtab_cache_destroy(); 2056 goto out; 2057 } 2058 2059 policydb.len = len; 2060 rc = selinux_set_mapping(&policydb, secclass_map, 2061 ¤t_mapping, 2062 ¤t_mapping_size); 2063 if (rc) { 2064 policydb_destroy(&policydb); 2065 avtab_cache_destroy(); 2066 goto out; 2067 } 2068 2069 rc = policydb_load_isids(&policydb, &sidtab); 2070 if (rc) { 2071 policydb_destroy(&policydb); 2072 avtab_cache_destroy(); 2073 goto out; 2074 } 2075 2076 security_load_policycaps(); 2077 ss_initialized = 1; 2078 seqno = ++latest_granting; 2079 selinux_complete_init(); 2080 avc_ss_reset(seqno); 2081 selnl_notify_policyload(seqno); 2082 selinux_status_update_policyload(seqno); 2083 selinux_netlbl_cache_invalidate(); 2084 selinux_xfrm_notify_policyload(); 2085 goto out; 2086 } 2087 2088 #if 0 2089 sidtab_hash_eval(&sidtab, "sids"); 2090 #endif 2091 2092 rc = policydb_read(newpolicydb, fp); 2093 if (rc) 2094 goto out; 2095 2096 newpolicydb->len = len; 2097 /* If switching between different policy types, log MLS status */ 2098 if (policydb.mls_enabled && !newpolicydb->mls_enabled) 2099 printk(KERN_INFO "SELinux: Disabling MLS support...\n"); 2100 else if (!policydb.mls_enabled && newpolicydb->mls_enabled) 2101 printk(KERN_INFO "SELinux: Enabling MLS support...\n"); 2102 2103 rc = policydb_load_isids(newpolicydb, &newsidtab); 2104 if (rc) { 2105 printk(KERN_ERR "SELinux: unable to load the initial SIDs\n"); 2106 policydb_destroy(newpolicydb); 2107 goto out; 2108 } 2109 2110 rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size); 2111 if (rc) 2112 goto err; 2113 2114 rc = security_preserve_bools(newpolicydb); 2115 if (rc) { 2116 printk(KERN_ERR "SELinux: unable to preserve booleans\n"); 2117 goto err; 2118 } 2119 2120 /* Clone the SID table. */ 2121 sidtab_shutdown(&sidtab); 2122 2123 rc = sidtab_map(&sidtab, clone_sid, &newsidtab); 2124 if (rc) 2125 goto err; 2126 2127 /* 2128 * Convert the internal representations of contexts 2129 * in the new SID table. 2130 */ 2131 args.oldp = &policydb; 2132 args.newp = newpolicydb; 2133 rc = sidtab_map(&newsidtab, convert_context, &args); 2134 if (rc) { 2135 printk(KERN_ERR "SELinux: unable to convert the internal" 2136 " representation of contexts in the new SID" 2137 " table\n"); 2138 goto err; 2139 } 2140 2141 /* Save the old policydb and SID table to free later. */ 2142 memcpy(oldpolicydb, &policydb, sizeof(policydb)); 2143 sidtab_set(&oldsidtab, &sidtab); 2144 2145 /* Install the new policydb and SID table. */ 2146 write_lock_irq(&policy_rwlock); 2147 memcpy(&policydb, newpolicydb, sizeof(policydb)); 2148 sidtab_set(&sidtab, &newsidtab); 2149 security_load_policycaps(); 2150 oldmap = current_mapping; 2151 current_mapping = map; 2152 current_mapping_size = map_size; 2153 seqno = ++latest_granting; 2154 write_unlock_irq(&policy_rwlock); 2155 2156 /* Free the old policydb and SID table. */ 2157 policydb_destroy(oldpolicydb); 2158 sidtab_destroy(&oldsidtab); 2159 kfree(oldmap); 2160 2161 avc_ss_reset(seqno); 2162 selnl_notify_policyload(seqno); 2163 selinux_status_update_policyload(seqno); 2164 selinux_netlbl_cache_invalidate(); 2165 selinux_xfrm_notify_policyload(); 2166 2167 rc = 0; 2168 goto out; 2169 2170 err: 2171 kfree(map); 2172 sidtab_destroy(&newsidtab); 2173 policydb_destroy(newpolicydb); 2174 2175 out: 2176 kfree(oldpolicydb); 2177 return rc; 2178 } 2179 2180 size_t security_policydb_len(void) 2181 { 2182 size_t len; 2183 2184 read_lock(&policy_rwlock); 2185 len = policydb.len; 2186 read_unlock(&policy_rwlock); 2187 2188 return len; 2189 } 2190 2191 /** 2192 * security_port_sid - Obtain the SID for a port. 2193 * @protocol: protocol number 2194 * @port: port number 2195 * @out_sid: security identifier 2196 */ 2197 int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2198 { 2199 struct ocontext *c; 2200 int rc = 0; 2201 2202 read_lock(&policy_rwlock); 2203 2204 c = policydb.ocontexts[OCON_PORT]; 2205 while (c) { 2206 if (c->u.port.protocol == protocol && 2207 c->u.port.low_port <= port && 2208 c->u.port.high_port >= port) 2209 break; 2210 c = c->next; 2211 } 2212 2213 if (c) { 2214 if (!c->sid[0]) { 2215 rc = sidtab_context_to_sid(&sidtab, 2216 &c->context[0], 2217 &c->sid[0]); 2218 if (rc) 2219 goto out; 2220 } 2221 *out_sid = c->sid[0]; 2222 } else { 2223 *out_sid = SECINITSID_PORT; 2224 } 2225 2226 out: 2227 read_unlock(&policy_rwlock); 2228 return rc; 2229 } 2230 2231 /** 2232 * security_netif_sid - Obtain the SID for a network interface. 2233 * @name: interface name 2234 * @if_sid: interface SID 2235 */ 2236 int security_netif_sid(char *name, u32 *if_sid) 2237 { 2238 int rc = 0; 2239 struct ocontext *c; 2240 2241 read_lock(&policy_rwlock); 2242 2243 c = policydb.ocontexts[OCON_NETIF]; 2244 while (c) { 2245 if (strcmp(name, c->u.name) == 0) 2246 break; 2247 c = c->next; 2248 } 2249 2250 if (c) { 2251 if (!c->sid[0] || !c->sid[1]) { 2252 rc = sidtab_context_to_sid(&sidtab, 2253 &c->context[0], 2254 &c->sid[0]); 2255 if (rc) 2256 goto out; 2257 rc = sidtab_context_to_sid(&sidtab, 2258 &c->context[1], 2259 &c->sid[1]); 2260 if (rc) 2261 goto out; 2262 } 2263 *if_sid = c->sid[0]; 2264 } else 2265 *if_sid = SECINITSID_NETIF; 2266 2267 out: 2268 read_unlock(&policy_rwlock); 2269 return rc; 2270 } 2271 2272 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2273 { 2274 int i, fail = 0; 2275 2276 for (i = 0; i < 4; i++) 2277 if (addr[i] != (input[i] & mask[i])) { 2278 fail = 1; 2279 break; 2280 } 2281 2282 return !fail; 2283 } 2284 2285 /** 2286 * security_node_sid - Obtain the SID for a node (host). 2287 * @domain: communication domain aka address family 2288 * @addrp: address 2289 * @addrlen: address length in bytes 2290 * @out_sid: security identifier 2291 */ 2292 int security_node_sid(u16 domain, 2293 void *addrp, 2294 u32 addrlen, 2295 u32 *out_sid) 2296 { 2297 int rc; 2298 struct ocontext *c; 2299 2300 read_lock(&policy_rwlock); 2301 2302 switch (domain) { 2303 case AF_INET: { 2304 u32 addr; 2305 2306 rc = -EINVAL; 2307 if (addrlen != sizeof(u32)) 2308 goto out; 2309 2310 addr = *((u32 *)addrp); 2311 2312 c = policydb.ocontexts[OCON_NODE]; 2313 while (c) { 2314 if (c->u.node.addr == (addr & c->u.node.mask)) 2315 break; 2316 c = c->next; 2317 } 2318 break; 2319 } 2320 2321 case AF_INET6: 2322 rc = -EINVAL; 2323 if (addrlen != sizeof(u64) * 2) 2324 goto out; 2325 c = policydb.ocontexts[OCON_NODE6]; 2326 while (c) { 2327 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2328 c->u.node6.mask)) 2329 break; 2330 c = c->next; 2331 } 2332 break; 2333 2334 default: 2335 rc = 0; 2336 *out_sid = SECINITSID_NODE; 2337 goto out; 2338 } 2339 2340 if (c) { 2341 if (!c->sid[0]) { 2342 rc = sidtab_context_to_sid(&sidtab, 2343 &c->context[0], 2344 &c->sid[0]); 2345 if (rc) 2346 goto out; 2347 } 2348 *out_sid = c->sid[0]; 2349 } else { 2350 *out_sid = SECINITSID_NODE; 2351 } 2352 2353 rc = 0; 2354 out: 2355 read_unlock(&policy_rwlock); 2356 return rc; 2357 } 2358 2359 #define SIDS_NEL 25 2360 2361 /** 2362 * security_get_user_sids - Obtain reachable SIDs for a user. 2363 * @fromsid: starting SID 2364 * @username: username 2365 * @sids: array of reachable SIDs for user 2366 * @nel: number of elements in @sids 2367 * 2368 * Generate the set of SIDs for legal security contexts 2369 * for a given user that can be reached by @fromsid. 2370 * Set *@sids to point to a dynamically allocated 2371 * array containing the set of SIDs. Set *@nel to the 2372 * number of elements in the array. 2373 */ 2374 2375 int security_get_user_sids(u32 fromsid, 2376 char *username, 2377 u32 **sids, 2378 u32 *nel) 2379 { 2380 struct context *fromcon, usercon; 2381 u32 *mysids = NULL, *mysids2, sid; 2382 u32 mynel = 0, maxnel = SIDS_NEL; 2383 struct user_datum *user; 2384 struct role_datum *role; 2385 struct ebitmap_node *rnode, *tnode; 2386 int rc = 0, i, j; 2387 2388 *sids = NULL; 2389 *nel = 0; 2390 2391 if (!ss_initialized) 2392 goto out; 2393 2394 read_lock(&policy_rwlock); 2395 2396 context_init(&usercon); 2397 2398 rc = -EINVAL; 2399 fromcon = sidtab_search(&sidtab, fromsid); 2400 if (!fromcon) 2401 goto out_unlock; 2402 2403 rc = -EINVAL; 2404 user = hashtab_search(policydb.p_users.table, username); 2405 if (!user) 2406 goto out_unlock; 2407 2408 usercon.user = user->value; 2409 2410 rc = -ENOMEM; 2411 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); 2412 if (!mysids) 2413 goto out_unlock; 2414 2415 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2416 role = policydb.role_val_to_struct[i]; 2417 usercon.role = i + 1; 2418 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2419 usercon.type = j + 1; 2420 2421 if (mls_setup_user_range(fromcon, user, &usercon)) 2422 continue; 2423 2424 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); 2425 if (rc) 2426 goto out_unlock; 2427 if (mynel < maxnel) { 2428 mysids[mynel++] = sid; 2429 } else { 2430 rc = -ENOMEM; 2431 maxnel += SIDS_NEL; 2432 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2433 if (!mysids2) 2434 goto out_unlock; 2435 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2436 kfree(mysids); 2437 mysids = mysids2; 2438 mysids[mynel++] = sid; 2439 } 2440 } 2441 } 2442 rc = 0; 2443 out_unlock: 2444 read_unlock(&policy_rwlock); 2445 if (rc || !mynel) { 2446 kfree(mysids); 2447 goto out; 2448 } 2449 2450 rc = -ENOMEM; 2451 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2452 if (!mysids2) { 2453 kfree(mysids); 2454 goto out; 2455 } 2456 for (i = 0, j = 0; i < mynel; i++) { 2457 struct av_decision dummy_avd; 2458 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2459 SECCLASS_PROCESS, /* kernel value */ 2460 PROCESS__TRANSITION, AVC_STRICT, 2461 &dummy_avd); 2462 if (!rc) 2463 mysids2[j++] = mysids[i]; 2464 cond_resched(); 2465 } 2466 rc = 0; 2467 kfree(mysids); 2468 *sids = mysids2; 2469 *nel = j; 2470 out: 2471 return rc; 2472 } 2473 2474 /** 2475 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2476 * @fstype: filesystem type 2477 * @path: path from root of mount 2478 * @sclass: file security class 2479 * @sid: SID for path 2480 * 2481 * Obtain a SID to use for a file in a filesystem that 2482 * cannot support xattr or use a fixed labeling behavior like 2483 * transition SIDs or task SIDs. 2484 * 2485 * The caller must acquire the policy_rwlock before calling this function. 2486 */ 2487 static inline int __security_genfs_sid(const char *fstype, 2488 char *path, 2489 u16 orig_sclass, 2490 u32 *sid) 2491 { 2492 int len; 2493 u16 sclass; 2494 struct genfs *genfs; 2495 struct ocontext *c; 2496 int rc, cmp = 0; 2497 2498 while (path[0] == '/' && path[1] == '/') 2499 path++; 2500 2501 sclass = unmap_class(orig_sclass); 2502 *sid = SECINITSID_UNLABELED; 2503 2504 for (genfs = policydb.genfs; genfs; genfs = genfs->next) { 2505 cmp = strcmp(fstype, genfs->fstype); 2506 if (cmp <= 0) 2507 break; 2508 } 2509 2510 rc = -ENOENT; 2511 if (!genfs || cmp) 2512 goto out; 2513 2514 for (c = genfs->head; c; c = c->next) { 2515 len = strlen(c->u.name); 2516 if ((!c->v.sclass || sclass == c->v.sclass) && 2517 (strncmp(c->u.name, path, len) == 0)) 2518 break; 2519 } 2520 2521 rc = -ENOENT; 2522 if (!c) 2523 goto out; 2524 2525 if (!c->sid[0]) { 2526 rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); 2527 if (rc) 2528 goto out; 2529 } 2530 2531 *sid = c->sid[0]; 2532 rc = 0; 2533 out: 2534 return rc; 2535 } 2536 2537 /** 2538 * security_genfs_sid - Obtain a SID for a file in a filesystem 2539 * @fstype: filesystem type 2540 * @path: path from root of mount 2541 * @sclass: file security class 2542 * @sid: SID for path 2543 * 2544 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2545 * it afterward. 2546 */ 2547 int security_genfs_sid(const char *fstype, 2548 char *path, 2549 u16 orig_sclass, 2550 u32 *sid) 2551 { 2552 int retval; 2553 2554 read_lock(&policy_rwlock); 2555 retval = __security_genfs_sid(fstype, path, orig_sclass, sid); 2556 read_unlock(&policy_rwlock); 2557 return retval; 2558 } 2559 2560 /** 2561 * security_fs_use - Determine how to handle labeling for a filesystem. 2562 * @sb: superblock in question 2563 */ 2564 int security_fs_use(struct super_block *sb) 2565 { 2566 int rc = 0; 2567 struct ocontext *c; 2568 struct superblock_security_struct *sbsec = sb->s_security; 2569 const char *fstype = sb->s_type->name; 2570 2571 read_lock(&policy_rwlock); 2572 2573 c = policydb.ocontexts[OCON_FSUSE]; 2574 while (c) { 2575 if (strcmp(fstype, c->u.name) == 0) 2576 break; 2577 c = c->next; 2578 } 2579 2580 if (c) { 2581 sbsec->behavior = c->v.behavior; 2582 if (!c->sid[0]) { 2583 rc = sidtab_context_to_sid(&sidtab, &c->context[0], 2584 &c->sid[0]); 2585 if (rc) 2586 goto out; 2587 } 2588 sbsec->sid = c->sid[0]; 2589 } else { 2590 rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR, 2591 &sbsec->sid); 2592 if (rc) { 2593 sbsec->behavior = SECURITY_FS_USE_NONE; 2594 rc = 0; 2595 } else { 2596 sbsec->behavior = SECURITY_FS_USE_GENFS; 2597 } 2598 } 2599 2600 out: 2601 read_unlock(&policy_rwlock); 2602 return rc; 2603 } 2604 2605 int security_get_bools(int *len, char ***names, int **values) 2606 { 2607 int i, rc; 2608 2609 read_lock(&policy_rwlock); 2610 *names = NULL; 2611 *values = NULL; 2612 2613 rc = 0; 2614 *len = policydb.p_bools.nprim; 2615 if (!*len) 2616 goto out; 2617 2618 rc = -ENOMEM; 2619 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2620 if (!*names) 2621 goto err; 2622 2623 rc = -ENOMEM; 2624 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2625 if (!*values) 2626 goto err; 2627 2628 for (i = 0; i < *len; i++) { 2629 (*values)[i] = policydb.bool_val_to_struct[i]->state; 2630 2631 rc = -ENOMEM; 2632 (*names)[i] = kstrdup(sym_name(&policydb, SYM_BOOLS, i), GFP_ATOMIC); 2633 if (!(*names)[i]) 2634 goto err; 2635 } 2636 rc = 0; 2637 out: 2638 read_unlock(&policy_rwlock); 2639 return rc; 2640 err: 2641 if (*names) { 2642 for (i = 0; i < *len; i++) 2643 kfree((*names)[i]); 2644 } 2645 kfree(*values); 2646 goto out; 2647 } 2648 2649 2650 int security_set_bools(int len, int *values) 2651 { 2652 int i, rc; 2653 int lenp, seqno = 0; 2654 struct cond_node *cur; 2655 2656 write_lock_irq(&policy_rwlock); 2657 2658 rc = -EFAULT; 2659 lenp = policydb.p_bools.nprim; 2660 if (len != lenp) 2661 goto out; 2662 2663 for (i = 0; i < len; i++) { 2664 if (!!values[i] != policydb.bool_val_to_struct[i]->state) { 2665 audit_log(current->audit_context, GFP_ATOMIC, 2666 AUDIT_MAC_CONFIG_CHANGE, 2667 "bool=%s val=%d old_val=%d auid=%u ses=%u", 2668 sym_name(&policydb, SYM_BOOLS, i), 2669 !!values[i], 2670 policydb.bool_val_to_struct[i]->state, 2671 from_kuid(&init_user_ns, audit_get_loginuid(current)), 2672 audit_get_sessionid(current)); 2673 } 2674 if (values[i]) 2675 policydb.bool_val_to_struct[i]->state = 1; 2676 else 2677 policydb.bool_val_to_struct[i]->state = 0; 2678 } 2679 2680 for (cur = policydb.cond_list; cur; cur = cur->next) { 2681 rc = evaluate_cond_node(&policydb, cur); 2682 if (rc) 2683 goto out; 2684 } 2685 2686 seqno = ++latest_granting; 2687 rc = 0; 2688 out: 2689 write_unlock_irq(&policy_rwlock); 2690 if (!rc) { 2691 avc_ss_reset(seqno); 2692 selnl_notify_policyload(seqno); 2693 selinux_status_update_policyload(seqno); 2694 selinux_xfrm_notify_policyload(); 2695 } 2696 return rc; 2697 } 2698 2699 int security_get_bool_value(int index) 2700 { 2701 int rc; 2702 int len; 2703 2704 read_lock(&policy_rwlock); 2705 2706 rc = -EFAULT; 2707 len = policydb.p_bools.nprim; 2708 if (index >= len) 2709 goto out; 2710 2711 rc = policydb.bool_val_to_struct[index]->state; 2712 out: 2713 read_unlock(&policy_rwlock); 2714 return rc; 2715 } 2716 2717 static int security_preserve_bools(struct policydb *p) 2718 { 2719 int rc, nbools = 0, *bvalues = NULL, i; 2720 char **bnames = NULL; 2721 struct cond_bool_datum *booldatum; 2722 struct cond_node *cur; 2723 2724 rc = security_get_bools(&nbools, &bnames, &bvalues); 2725 if (rc) 2726 goto out; 2727 for (i = 0; i < nbools; i++) { 2728 booldatum = hashtab_search(p->p_bools.table, bnames[i]); 2729 if (booldatum) 2730 booldatum->state = bvalues[i]; 2731 } 2732 for (cur = p->cond_list; cur; cur = cur->next) { 2733 rc = evaluate_cond_node(p, cur); 2734 if (rc) 2735 goto out; 2736 } 2737 2738 out: 2739 if (bnames) { 2740 for (i = 0; i < nbools; i++) 2741 kfree(bnames[i]); 2742 } 2743 kfree(bnames); 2744 kfree(bvalues); 2745 return rc; 2746 } 2747 2748 /* 2749 * security_sid_mls_copy() - computes a new sid based on the given 2750 * sid and the mls portion of mls_sid. 2751 */ 2752 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 2753 { 2754 struct context *context1; 2755 struct context *context2; 2756 struct context newcon; 2757 char *s; 2758 u32 len; 2759 int rc; 2760 2761 rc = 0; 2762 if (!ss_initialized || !policydb.mls_enabled) { 2763 *new_sid = sid; 2764 goto out; 2765 } 2766 2767 context_init(&newcon); 2768 2769 read_lock(&policy_rwlock); 2770 2771 rc = -EINVAL; 2772 context1 = sidtab_search(&sidtab, sid); 2773 if (!context1) { 2774 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2775 __func__, sid); 2776 goto out_unlock; 2777 } 2778 2779 rc = -EINVAL; 2780 context2 = sidtab_search(&sidtab, mls_sid); 2781 if (!context2) { 2782 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2783 __func__, mls_sid); 2784 goto out_unlock; 2785 } 2786 2787 newcon.user = context1->user; 2788 newcon.role = context1->role; 2789 newcon.type = context1->type; 2790 rc = mls_context_cpy(&newcon, context2); 2791 if (rc) 2792 goto out_unlock; 2793 2794 /* Check the validity of the new context. */ 2795 if (!policydb_context_isvalid(&policydb, &newcon)) { 2796 rc = convert_context_handle_invalid_context(&newcon); 2797 if (rc) { 2798 if (!context_struct_to_string(&newcon, &s, &len)) { 2799 audit_log(current->audit_context, 2800 GFP_ATOMIC, AUDIT_SELINUX_ERR, 2801 "op=security_sid_mls_copy " 2802 "invalid_context=%s", s); 2803 kfree(s); 2804 } 2805 goto out_unlock; 2806 } 2807 } 2808 2809 rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid); 2810 out_unlock: 2811 read_unlock(&policy_rwlock); 2812 context_destroy(&newcon); 2813 out: 2814 return rc; 2815 } 2816 2817 /** 2818 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 2819 * @nlbl_sid: NetLabel SID 2820 * @nlbl_type: NetLabel labeling protocol type 2821 * @xfrm_sid: XFRM SID 2822 * 2823 * Description: 2824 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 2825 * resolved into a single SID it is returned via @peer_sid and the function 2826 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 2827 * returns a negative value. A table summarizing the behavior is below: 2828 * 2829 * | function return | @sid 2830 * ------------------------------+-----------------+----------------- 2831 * no peer labels | 0 | SECSID_NULL 2832 * single peer label | 0 | <peer_label> 2833 * multiple, consistent labels | 0 | <peer_label> 2834 * multiple, inconsistent labels | -<errno> | SECSID_NULL 2835 * 2836 */ 2837 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 2838 u32 xfrm_sid, 2839 u32 *peer_sid) 2840 { 2841 int rc; 2842 struct context *nlbl_ctx; 2843 struct context *xfrm_ctx; 2844 2845 *peer_sid = SECSID_NULL; 2846 2847 /* handle the common (which also happens to be the set of easy) cases 2848 * right away, these two if statements catch everything involving a 2849 * single or absent peer SID/label */ 2850 if (xfrm_sid == SECSID_NULL) { 2851 *peer_sid = nlbl_sid; 2852 return 0; 2853 } 2854 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 2855 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 2856 * is present */ 2857 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 2858 *peer_sid = xfrm_sid; 2859 return 0; 2860 } 2861 2862 /* we don't need to check ss_initialized here since the only way both 2863 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 2864 * security server was initialized and ss_initialized was true */ 2865 if (!policydb.mls_enabled) 2866 return 0; 2867 2868 read_lock(&policy_rwlock); 2869 2870 rc = -EINVAL; 2871 nlbl_ctx = sidtab_search(&sidtab, nlbl_sid); 2872 if (!nlbl_ctx) { 2873 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2874 __func__, nlbl_sid); 2875 goto out; 2876 } 2877 rc = -EINVAL; 2878 xfrm_ctx = sidtab_search(&sidtab, xfrm_sid); 2879 if (!xfrm_ctx) { 2880 printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", 2881 __func__, xfrm_sid); 2882 goto out; 2883 } 2884 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 2885 if (rc) 2886 goto out; 2887 2888 /* at present NetLabel SIDs/labels really only carry MLS 2889 * information so if the MLS portion of the NetLabel SID 2890 * matches the MLS portion of the labeled XFRM SID/label 2891 * then pass along the XFRM SID as it is the most 2892 * expressive */ 2893 *peer_sid = xfrm_sid; 2894 out: 2895 read_unlock(&policy_rwlock); 2896 return rc; 2897 } 2898 2899 static int get_classes_callback(void *k, void *d, void *args) 2900 { 2901 struct class_datum *datum = d; 2902 char *name = k, **classes = args; 2903 int value = datum->value - 1; 2904 2905 classes[value] = kstrdup(name, GFP_ATOMIC); 2906 if (!classes[value]) 2907 return -ENOMEM; 2908 2909 return 0; 2910 } 2911 2912 int security_get_classes(char ***classes, int *nclasses) 2913 { 2914 int rc; 2915 2916 read_lock(&policy_rwlock); 2917 2918 rc = -ENOMEM; 2919 *nclasses = policydb.p_classes.nprim; 2920 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 2921 if (!*classes) 2922 goto out; 2923 2924 rc = hashtab_map(policydb.p_classes.table, get_classes_callback, 2925 *classes); 2926 if (rc) { 2927 int i; 2928 for (i = 0; i < *nclasses; i++) 2929 kfree((*classes)[i]); 2930 kfree(*classes); 2931 } 2932 2933 out: 2934 read_unlock(&policy_rwlock); 2935 return rc; 2936 } 2937 2938 static int get_permissions_callback(void *k, void *d, void *args) 2939 { 2940 struct perm_datum *datum = d; 2941 char *name = k, **perms = args; 2942 int value = datum->value - 1; 2943 2944 perms[value] = kstrdup(name, GFP_ATOMIC); 2945 if (!perms[value]) 2946 return -ENOMEM; 2947 2948 return 0; 2949 } 2950 2951 int security_get_permissions(char *class, char ***perms, int *nperms) 2952 { 2953 int rc, i; 2954 struct class_datum *match; 2955 2956 read_lock(&policy_rwlock); 2957 2958 rc = -EINVAL; 2959 match = hashtab_search(policydb.p_classes.table, class); 2960 if (!match) { 2961 printk(KERN_ERR "SELinux: %s: unrecognized class %s\n", 2962 __func__, class); 2963 goto out; 2964 } 2965 2966 rc = -ENOMEM; 2967 *nperms = match->permissions.nprim; 2968 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 2969 if (!*perms) 2970 goto out; 2971 2972 if (match->comdatum) { 2973 rc = hashtab_map(match->comdatum->permissions.table, 2974 get_permissions_callback, *perms); 2975 if (rc) 2976 goto err; 2977 } 2978 2979 rc = hashtab_map(match->permissions.table, get_permissions_callback, 2980 *perms); 2981 if (rc) 2982 goto err; 2983 2984 out: 2985 read_unlock(&policy_rwlock); 2986 return rc; 2987 2988 err: 2989 read_unlock(&policy_rwlock); 2990 for (i = 0; i < *nperms; i++) 2991 kfree((*perms)[i]); 2992 kfree(*perms); 2993 return rc; 2994 } 2995 2996 int security_get_reject_unknown(void) 2997 { 2998 return policydb.reject_unknown; 2999 } 3000 3001 int security_get_allow_unknown(void) 3002 { 3003 return policydb.allow_unknown; 3004 } 3005 3006 /** 3007 * security_policycap_supported - Check for a specific policy capability 3008 * @req_cap: capability 3009 * 3010 * Description: 3011 * This function queries the currently loaded policy to see if it supports the 3012 * capability specified by @req_cap. Returns true (1) if the capability is 3013 * supported, false (0) if it isn't supported. 3014 * 3015 */ 3016 int security_policycap_supported(unsigned int req_cap) 3017 { 3018 int rc; 3019 3020 read_lock(&policy_rwlock); 3021 rc = ebitmap_get_bit(&policydb.policycaps, req_cap); 3022 read_unlock(&policy_rwlock); 3023 3024 return rc; 3025 } 3026 3027 struct selinux_audit_rule { 3028 u32 au_seqno; 3029 struct context au_ctxt; 3030 }; 3031 3032 void selinux_audit_rule_free(void *vrule) 3033 { 3034 struct selinux_audit_rule *rule = vrule; 3035 3036 if (rule) { 3037 context_destroy(&rule->au_ctxt); 3038 kfree(rule); 3039 } 3040 } 3041 3042 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3043 { 3044 struct selinux_audit_rule *tmprule; 3045 struct role_datum *roledatum; 3046 struct type_datum *typedatum; 3047 struct user_datum *userdatum; 3048 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3049 int rc = 0; 3050 3051 *rule = NULL; 3052 3053 if (!ss_initialized) 3054 return -EOPNOTSUPP; 3055 3056 switch (field) { 3057 case AUDIT_SUBJ_USER: 3058 case AUDIT_SUBJ_ROLE: 3059 case AUDIT_SUBJ_TYPE: 3060 case AUDIT_OBJ_USER: 3061 case AUDIT_OBJ_ROLE: 3062 case AUDIT_OBJ_TYPE: 3063 /* only 'equals' and 'not equals' fit user, role, and type */ 3064 if (op != Audit_equal && op != Audit_not_equal) 3065 return -EINVAL; 3066 break; 3067 case AUDIT_SUBJ_SEN: 3068 case AUDIT_SUBJ_CLR: 3069 case AUDIT_OBJ_LEV_LOW: 3070 case AUDIT_OBJ_LEV_HIGH: 3071 /* we do not allow a range, indicated by the presence of '-' */ 3072 if (strchr(rulestr, '-')) 3073 return -EINVAL; 3074 break; 3075 default: 3076 /* only the above fields are valid */ 3077 return -EINVAL; 3078 } 3079 3080 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3081 if (!tmprule) 3082 return -ENOMEM; 3083 3084 context_init(&tmprule->au_ctxt); 3085 3086 read_lock(&policy_rwlock); 3087 3088 tmprule->au_seqno = latest_granting; 3089 3090 switch (field) { 3091 case AUDIT_SUBJ_USER: 3092 case AUDIT_OBJ_USER: 3093 rc = -EINVAL; 3094 userdatum = hashtab_search(policydb.p_users.table, rulestr); 3095 if (!userdatum) 3096 goto out; 3097 tmprule->au_ctxt.user = userdatum->value; 3098 break; 3099 case AUDIT_SUBJ_ROLE: 3100 case AUDIT_OBJ_ROLE: 3101 rc = -EINVAL; 3102 roledatum = hashtab_search(policydb.p_roles.table, rulestr); 3103 if (!roledatum) 3104 goto out; 3105 tmprule->au_ctxt.role = roledatum->value; 3106 break; 3107 case AUDIT_SUBJ_TYPE: 3108 case AUDIT_OBJ_TYPE: 3109 rc = -EINVAL; 3110 typedatum = hashtab_search(policydb.p_types.table, rulestr); 3111 if (!typedatum) 3112 goto out; 3113 tmprule->au_ctxt.type = typedatum->value; 3114 break; 3115 case AUDIT_SUBJ_SEN: 3116 case AUDIT_SUBJ_CLR: 3117 case AUDIT_OBJ_LEV_LOW: 3118 case AUDIT_OBJ_LEV_HIGH: 3119 rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC); 3120 if (rc) 3121 goto out; 3122 break; 3123 } 3124 rc = 0; 3125 out: 3126 read_unlock(&policy_rwlock); 3127 3128 if (rc) { 3129 selinux_audit_rule_free(tmprule); 3130 tmprule = NULL; 3131 } 3132 3133 *rule = tmprule; 3134 3135 return rc; 3136 } 3137 3138 /* Check to see if the rule contains any selinux fields */ 3139 int selinux_audit_rule_known(struct audit_krule *rule) 3140 { 3141 int i; 3142 3143 for (i = 0; i < rule->field_count; i++) { 3144 struct audit_field *f = &rule->fields[i]; 3145 switch (f->type) { 3146 case AUDIT_SUBJ_USER: 3147 case AUDIT_SUBJ_ROLE: 3148 case AUDIT_SUBJ_TYPE: 3149 case AUDIT_SUBJ_SEN: 3150 case AUDIT_SUBJ_CLR: 3151 case AUDIT_OBJ_USER: 3152 case AUDIT_OBJ_ROLE: 3153 case AUDIT_OBJ_TYPE: 3154 case AUDIT_OBJ_LEV_LOW: 3155 case AUDIT_OBJ_LEV_HIGH: 3156 return 1; 3157 } 3158 } 3159 3160 return 0; 3161 } 3162 3163 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, 3164 struct audit_context *actx) 3165 { 3166 struct context *ctxt; 3167 struct mls_level *level; 3168 struct selinux_audit_rule *rule = vrule; 3169 int match = 0; 3170 3171 if (unlikely(!rule)) { 3172 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3173 return -ENOENT; 3174 } 3175 3176 read_lock(&policy_rwlock); 3177 3178 if (rule->au_seqno < latest_granting) { 3179 match = -ESTALE; 3180 goto out; 3181 } 3182 3183 ctxt = sidtab_search(&sidtab, sid); 3184 if (unlikely(!ctxt)) { 3185 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3186 sid); 3187 match = -ENOENT; 3188 goto out; 3189 } 3190 3191 /* a field/op pair that is not caught here will simply fall through 3192 without a match */ 3193 switch (field) { 3194 case AUDIT_SUBJ_USER: 3195 case AUDIT_OBJ_USER: 3196 switch (op) { 3197 case Audit_equal: 3198 match = (ctxt->user == rule->au_ctxt.user); 3199 break; 3200 case Audit_not_equal: 3201 match = (ctxt->user != rule->au_ctxt.user); 3202 break; 3203 } 3204 break; 3205 case AUDIT_SUBJ_ROLE: 3206 case AUDIT_OBJ_ROLE: 3207 switch (op) { 3208 case Audit_equal: 3209 match = (ctxt->role == rule->au_ctxt.role); 3210 break; 3211 case Audit_not_equal: 3212 match = (ctxt->role != rule->au_ctxt.role); 3213 break; 3214 } 3215 break; 3216 case AUDIT_SUBJ_TYPE: 3217 case AUDIT_OBJ_TYPE: 3218 switch (op) { 3219 case Audit_equal: 3220 match = (ctxt->type == rule->au_ctxt.type); 3221 break; 3222 case Audit_not_equal: 3223 match = (ctxt->type != rule->au_ctxt.type); 3224 break; 3225 } 3226 break; 3227 case AUDIT_SUBJ_SEN: 3228 case AUDIT_SUBJ_CLR: 3229 case AUDIT_OBJ_LEV_LOW: 3230 case AUDIT_OBJ_LEV_HIGH: 3231 level = ((field == AUDIT_SUBJ_SEN || 3232 field == AUDIT_OBJ_LEV_LOW) ? 3233 &ctxt->range.level[0] : &ctxt->range.level[1]); 3234 switch (op) { 3235 case Audit_equal: 3236 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3237 level); 3238 break; 3239 case Audit_not_equal: 3240 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3241 level); 3242 break; 3243 case Audit_lt: 3244 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3245 level) && 3246 !mls_level_eq(&rule->au_ctxt.range.level[0], 3247 level)); 3248 break; 3249 case Audit_le: 3250 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3251 level); 3252 break; 3253 case Audit_gt: 3254 match = (mls_level_dom(level, 3255 &rule->au_ctxt.range.level[0]) && 3256 !mls_level_eq(level, 3257 &rule->au_ctxt.range.level[0])); 3258 break; 3259 case Audit_ge: 3260 match = mls_level_dom(level, 3261 &rule->au_ctxt.range.level[0]); 3262 break; 3263 } 3264 } 3265 3266 out: 3267 read_unlock(&policy_rwlock); 3268 return match; 3269 } 3270 3271 static int (*aurule_callback)(void) = audit_update_lsm_rules; 3272 3273 static int aurule_avc_callback(u32 event) 3274 { 3275 int err = 0; 3276 3277 if (event == AVC_CALLBACK_RESET && aurule_callback) 3278 err = aurule_callback(); 3279 return err; 3280 } 3281 3282 static int __init aurule_init(void) 3283 { 3284 int err; 3285 3286 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3287 if (err) 3288 panic("avc_add_callback() failed, error %d\n", err); 3289 3290 return err; 3291 } 3292 __initcall(aurule_init); 3293 3294 #ifdef CONFIG_NETLABEL 3295 /** 3296 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3297 * @secattr: the NetLabel packet security attributes 3298 * @sid: the SELinux SID 3299 * 3300 * Description: 3301 * Attempt to cache the context in @ctx, which was derived from the packet in 3302 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3303 * already been initialized. 3304 * 3305 */ 3306 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3307 u32 sid) 3308 { 3309 u32 *sid_cache; 3310 3311 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3312 if (sid_cache == NULL) 3313 return; 3314 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3315 if (secattr->cache == NULL) { 3316 kfree(sid_cache); 3317 return; 3318 } 3319 3320 *sid_cache = sid; 3321 secattr->cache->free = kfree; 3322 secattr->cache->data = sid_cache; 3323 secattr->flags |= NETLBL_SECATTR_CACHE; 3324 } 3325 3326 /** 3327 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3328 * @secattr: the NetLabel packet security attributes 3329 * @sid: the SELinux SID 3330 * 3331 * Description: 3332 * Convert the given NetLabel security attributes in @secattr into a 3333 * SELinux SID. If the @secattr field does not contain a full SELinux 3334 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3335 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3336 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3337 * conversion for future lookups. Returns zero on success, negative values on 3338 * failure. 3339 * 3340 */ 3341 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3342 u32 *sid) 3343 { 3344 int rc; 3345 struct context *ctx; 3346 struct context ctx_new; 3347 3348 if (!ss_initialized) { 3349 *sid = SECSID_NULL; 3350 return 0; 3351 } 3352 3353 read_lock(&policy_rwlock); 3354 3355 if (secattr->flags & NETLBL_SECATTR_CACHE) 3356 *sid = *(u32 *)secattr->cache->data; 3357 else if (secattr->flags & NETLBL_SECATTR_SECID) 3358 *sid = secattr->attr.secid; 3359 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3360 rc = -EIDRM; 3361 ctx = sidtab_search(&sidtab, SECINITSID_NETMSG); 3362 if (ctx == NULL) 3363 goto out; 3364 3365 context_init(&ctx_new); 3366 ctx_new.user = ctx->user; 3367 ctx_new.role = ctx->role; 3368 ctx_new.type = ctx->type; 3369 mls_import_netlbl_lvl(&ctx_new, secattr); 3370 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3371 rc = mls_import_netlbl_cat(&ctx_new, secattr); 3372 if (rc) 3373 goto out; 3374 } 3375 rc = -EIDRM; 3376 if (!mls_context_isvalid(&policydb, &ctx_new)) 3377 goto out_free; 3378 3379 rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); 3380 if (rc) 3381 goto out_free; 3382 3383 security_netlbl_cache_add(secattr, *sid); 3384 3385 ebitmap_destroy(&ctx_new.range.level[0].cat); 3386 } else 3387 *sid = SECSID_NULL; 3388 3389 read_unlock(&policy_rwlock); 3390 return 0; 3391 out_free: 3392 ebitmap_destroy(&ctx_new.range.level[0].cat); 3393 out: 3394 read_unlock(&policy_rwlock); 3395 return rc; 3396 } 3397 3398 /** 3399 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3400 * @sid: the SELinux SID 3401 * @secattr: the NetLabel packet security attributes 3402 * 3403 * Description: 3404 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3405 * Returns zero on success, negative values on failure. 3406 * 3407 */ 3408 int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3409 { 3410 int rc; 3411 struct context *ctx; 3412 3413 if (!ss_initialized) 3414 return 0; 3415 3416 read_lock(&policy_rwlock); 3417 3418 rc = -ENOENT; 3419 ctx = sidtab_search(&sidtab, sid); 3420 if (ctx == NULL) 3421 goto out; 3422 3423 rc = -ENOMEM; 3424 secattr->domain = kstrdup(sym_name(&policydb, SYM_TYPES, ctx->type - 1), 3425 GFP_ATOMIC); 3426 if (secattr->domain == NULL) 3427 goto out; 3428 3429 secattr->attr.secid = sid; 3430 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3431 mls_export_netlbl_lvl(ctx, secattr); 3432 rc = mls_export_netlbl_cat(ctx, secattr); 3433 out: 3434 read_unlock(&policy_rwlock); 3435 return rc; 3436 } 3437 #endif /* CONFIG_NETLABEL */ 3438 3439 /** 3440 * security_read_policy - read the policy. 3441 * @data: binary policy data 3442 * @len: length of data in bytes 3443 * 3444 */ 3445 int security_read_policy(void **data, size_t *len) 3446 { 3447 int rc; 3448 struct policy_file fp; 3449 3450 if (!ss_initialized) 3451 return -EINVAL; 3452 3453 *len = security_policydb_len(); 3454 3455 *data = vmalloc_user(*len); 3456 if (!*data) 3457 return -ENOMEM; 3458 3459 fp.data = *data; 3460 fp.len = *len; 3461 3462 read_lock(&policy_rwlock); 3463 rc = policydb_write(&policydb, &fp); 3464 read_unlock(&policy_rwlock); 3465 3466 if (rc) 3467 return rc; 3468 3469 *len = (unsigned long)fp.data - (unsigned long)*data; 3470 return 0; 3471 3472 } 3473