1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Implementation of the security services. 4 * 5 * Authors : Stephen Smalley, <stephen.smalley.work@gmail.com> 6 * James Morris <jmorris@redhat.com> 7 * 8 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> 9 * 10 * Support for enhanced MLS infrastructure. 11 * Support for context based audit filters. 12 * 13 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> 14 * 15 * Added conditional policy language extensions 16 * 17 * Updated: Hewlett-Packard <paul@paul-moore.com> 18 * 19 * Added support for NetLabel 20 * Added support for the policy capability bitmap 21 * 22 * Updated: Chad Sellers <csellers@tresys.com> 23 * 24 * Added validation of kernel classes and permissions 25 * 26 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> 27 * 28 * Added support for bounds domain and audit messaged on masked permissions 29 * 30 * Updated: Guido Trentalancia <guido@trentalancia.com> 31 * 32 * Added support for runtime switching of the policy type 33 * 34 * Copyright (C) 2008, 2009 NEC Corporation 35 * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. 36 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. 37 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC 38 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> 39 */ 40#include <linux/kernel.h> 41#include <linux/slab.h> 42#include <linux/string.h> 43#include <linux/spinlock.h> 44#include <linux/rcupdate.h> 45#include <linux/errno.h> 46#include <linux/in.h> 47#include <linux/sched.h> 48#include <linux/audit.h> 49#include <linux/vmalloc.h> 50#include <linux/lsm_hooks.h> 51#include <net/netlabel.h> 52 53#include "flask.h" 54#include "avc.h" 55#include "avc_ss.h" 56#include "security.h" 57#include "context.h" 58#include "policydb.h" 59#include "sidtab.h" 60#include "services.h" 61#include "conditional.h" 62#include "mls.h" 63#include "objsec.h" 64#include "netlabel.h" 65#include "xfrm.h" 66#include "ebitmap.h" 67#include "audit.h" 68#include "policycap_names.h" 69#include "ima.h" 70 71struct selinux_policy_convert_data { 72 struct convert_context_args args; 73 struct sidtab_convert_params sidtab_params; 74}; 75 76/* Forward declaration. */ 77static int context_struct_to_string(struct policydb *policydb, 78 struct context *context, 79 char **scontext, 80 u32 *scontext_len); 81 82static int sidtab_entry_to_string(struct policydb *policydb, 83 struct sidtab *sidtab, 84 struct sidtab_entry *entry, 85 char **scontext, 86 u32 *scontext_len); 87 88static void context_struct_compute_av(struct policydb *policydb, 89 struct context *scontext, 90 struct context *tcontext, 91 u16 tclass, 92 struct av_decision *avd, 93 struct extended_perms *xperms); 94 95static int selinux_set_mapping(struct policydb *pol, 96 const struct security_class_mapping *map, 97 struct selinux_map *out_map) 98{ 99 u16 i, j; 100 bool print_unknown_handle = false; 101 102 /* Find number of classes in the input mapping */ 103 if (!map) 104 return -EINVAL; 105 i = 0; 106 while (map[i].name) 107 i++; 108 109 /* Allocate space for the class records, plus one for class zero */ 110 out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); 111 if (!out_map->mapping) 112 return -ENOMEM; 113 114 /* Store the raw class and permission values */ 115 j = 0; 116 while (map[j].name) { 117 const struct security_class_mapping *p_in = map + (j++); 118 struct selinux_mapping *p_out = out_map->mapping + j; 119 u16 k; 120 121 /* An empty class string skips ahead */ 122 if (!strcmp(p_in->name, "")) { 123 p_out->num_perms = 0; 124 continue; 125 } 126 127 p_out->value = string_to_security_class(pol, p_in->name); 128 if (!p_out->value) { 129 pr_info("SELinux: Class %s not defined in policy.\n", 130 p_in->name); 131 if (pol->reject_unknown) 132 goto err; 133 p_out->num_perms = 0; 134 print_unknown_handle = true; 135 continue; 136 } 137 138 k = 0; 139 while (p_in->perms[k]) { 140 /* An empty permission string skips ahead */ 141 if (!*p_in->perms[k]) { 142 k++; 143 continue; 144 } 145 p_out->perms[k] = string_to_av_perm(pol, p_out->value, 146 p_in->perms[k]); 147 if (!p_out->perms[k]) { 148 pr_info("SELinux: Permission %s in class %s not defined in policy.\n", 149 p_in->perms[k], p_in->name); 150 if (pol->reject_unknown) 151 goto err; 152 print_unknown_handle = true; 153 } 154 155 k++; 156 } 157 p_out->num_perms = k; 158 } 159 160 if (print_unknown_handle) 161 pr_info("SELinux: the above unknown classes and permissions will be %s\n", 162 pol->allow_unknown ? "allowed" : "denied"); 163 164 out_map->size = i; 165 return 0; 166err: 167 kfree(out_map->mapping); 168 out_map->mapping = NULL; 169 return -EINVAL; 170} 171 172/* 173 * Get real, policy values from mapped values 174 */ 175 176static u16 unmap_class(struct selinux_map *map, u16 tclass) 177{ 178 if (tclass < map->size) 179 return map->mapping[tclass].value; 180 181 return tclass; 182} 183 184/* 185 * Get kernel value for class from its policy value 186 */ 187static u16 map_class(struct selinux_map *map, u16 pol_value) 188{ 189 u16 i; 190 191 for (i = 1; i < map->size; i++) { 192 if (map->mapping[i].value == pol_value) 193 return i; 194 } 195 196 return SECCLASS_NULL; 197} 198 199static void map_decision(struct selinux_map *map, 200 u16 tclass, struct av_decision *avd, 201 int allow_unknown) 202{ 203 if (tclass < map->size) { 204 struct selinux_mapping *mapping = &map->mapping[tclass]; 205 unsigned int i, n = mapping->num_perms; 206 u32 result; 207 208 for (i = 0, result = 0; i < n; i++) { 209 if (avd->allowed & mapping->perms[i]) 210 result |= (u32)1<<i; 211 if (allow_unknown && !mapping->perms[i]) 212 result |= (u32)1<<i; 213 } 214 avd->allowed = result; 215 216 for (i = 0, result = 0; i < n; i++) 217 if (avd->auditallow & mapping->perms[i]) 218 result |= (u32)1<<i; 219 avd->auditallow = result; 220 221 for (i = 0, result = 0; i < n; i++) { 222 if (avd->auditdeny & mapping->perms[i]) 223 result |= (u32)1<<i; 224 if (!allow_unknown && !mapping->perms[i]) 225 result |= (u32)1<<i; 226 } 227 /* 228 * In case the kernel has a bug and requests a permission 229 * between num_perms and the maximum permission number, we 230 * should audit that denial 231 */ 232 for (; i < (sizeof(u32)*8); i++) 233 result |= (u32)1<<i; 234 avd->auditdeny = result; 235 } 236} 237 238int security_mls_enabled(void) 239{ 240 int mls_enabled; 241 struct selinux_policy *policy; 242 243 if (!selinux_initialized()) 244 return 0; 245 246 rcu_read_lock(); 247 policy = rcu_dereference(selinux_state.policy); 248 mls_enabled = policy->policydb.mls_enabled; 249 rcu_read_unlock(); 250 return mls_enabled; 251} 252 253/* 254 * Return the boolean value of a constraint expression 255 * when it is applied to the specified source and target 256 * security contexts. 257 * 258 * xcontext is a special beast... It is used by the validatetrans rules 259 * only. For these rules, scontext is the context before the transition, 260 * tcontext is the context after the transition, and xcontext is the context 261 * of the process performing the transition. All other callers of 262 * constraint_expr_eval should pass in NULL for xcontext. 263 */ 264static int constraint_expr_eval(struct policydb *policydb, 265 struct context *scontext, 266 struct context *tcontext, 267 struct context *xcontext, 268 struct constraint_expr *cexpr) 269{ 270 u32 val1, val2; 271 struct context *c; 272 struct role_datum *r1, *r2; 273 struct mls_level *l1, *l2; 274 struct constraint_expr *e; 275 int s[CEXPR_MAXDEPTH]; 276 int sp = -1; 277 278 for (e = cexpr; e; e = e->next) { 279 switch (e->expr_type) { 280 case CEXPR_NOT: 281 BUG_ON(sp < 0); 282 s[sp] = !s[sp]; 283 break; 284 case CEXPR_AND: 285 BUG_ON(sp < 1); 286 sp--; 287 s[sp] &= s[sp + 1]; 288 break; 289 case CEXPR_OR: 290 BUG_ON(sp < 1); 291 sp--; 292 s[sp] |= s[sp + 1]; 293 break; 294 case CEXPR_ATTR: 295 if (sp == (CEXPR_MAXDEPTH - 1)) 296 return 0; 297 switch (e->attr) { 298 case CEXPR_USER: 299 val1 = scontext->user; 300 val2 = tcontext->user; 301 break; 302 case CEXPR_TYPE: 303 val1 = scontext->type; 304 val2 = tcontext->type; 305 break; 306 case CEXPR_ROLE: 307 val1 = scontext->role; 308 val2 = tcontext->role; 309 r1 = policydb->role_val_to_struct[val1 - 1]; 310 r2 = policydb->role_val_to_struct[val2 - 1]; 311 switch (e->op) { 312 case CEXPR_DOM: 313 s[++sp] = ebitmap_get_bit(&r1->dominates, 314 val2 - 1); 315 continue; 316 case CEXPR_DOMBY: 317 s[++sp] = ebitmap_get_bit(&r2->dominates, 318 val1 - 1); 319 continue; 320 case CEXPR_INCOMP: 321 s[++sp] = (!ebitmap_get_bit(&r1->dominates, 322 val2 - 1) && 323 !ebitmap_get_bit(&r2->dominates, 324 val1 - 1)); 325 continue; 326 default: 327 break; 328 } 329 break; 330 case CEXPR_L1L2: 331 l1 = &(scontext->range.level[0]); 332 l2 = &(tcontext->range.level[0]); 333 goto mls_ops; 334 case CEXPR_L1H2: 335 l1 = &(scontext->range.level[0]); 336 l2 = &(tcontext->range.level[1]); 337 goto mls_ops; 338 case CEXPR_H1L2: 339 l1 = &(scontext->range.level[1]); 340 l2 = &(tcontext->range.level[0]); 341 goto mls_ops; 342 case CEXPR_H1H2: 343 l1 = &(scontext->range.level[1]); 344 l2 = &(tcontext->range.level[1]); 345 goto mls_ops; 346 case CEXPR_L1H1: 347 l1 = &(scontext->range.level[0]); 348 l2 = &(scontext->range.level[1]); 349 goto mls_ops; 350 case CEXPR_L2H2: 351 l1 = &(tcontext->range.level[0]); 352 l2 = &(tcontext->range.level[1]); 353 goto mls_ops; 354mls_ops: 355 switch (e->op) { 356 case CEXPR_EQ: 357 s[++sp] = mls_level_eq(l1, l2); 358 continue; 359 case CEXPR_NEQ: 360 s[++sp] = !mls_level_eq(l1, l2); 361 continue; 362 case CEXPR_DOM: 363 s[++sp] = mls_level_dom(l1, l2); 364 continue; 365 case CEXPR_DOMBY: 366 s[++sp] = mls_level_dom(l2, l1); 367 continue; 368 case CEXPR_INCOMP: 369 s[++sp] = mls_level_incomp(l2, l1); 370 continue; 371 default: 372 BUG(); 373 return 0; 374 } 375 break; 376 default: 377 BUG(); 378 return 0; 379 } 380 381 switch (e->op) { 382 case CEXPR_EQ: 383 s[++sp] = (val1 == val2); 384 break; 385 case CEXPR_NEQ: 386 s[++sp] = (val1 != val2); 387 break; 388 default: 389 BUG(); 390 return 0; 391 } 392 break; 393 case CEXPR_NAMES: 394 if (sp == (CEXPR_MAXDEPTH-1)) 395 return 0; 396 c = scontext; 397 if (e->attr & CEXPR_TARGET) 398 c = tcontext; 399 else if (e->attr & CEXPR_XTARGET) { 400 c = xcontext; 401 if (!c) { 402 BUG(); 403 return 0; 404 } 405 } 406 if (e->attr & CEXPR_USER) 407 val1 = c->user; 408 else if (e->attr & CEXPR_ROLE) 409 val1 = c->role; 410 else if (e->attr & CEXPR_TYPE) 411 val1 = c->type; 412 else { 413 BUG(); 414 return 0; 415 } 416 417 switch (e->op) { 418 case CEXPR_EQ: 419 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 420 break; 421 case CEXPR_NEQ: 422 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 423 break; 424 default: 425 BUG(); 426 return 0; 427 } 428 break; 429 default: 430 BUG(); 431 return 0; 432 } 433 } 434 435 BUG_ON(sp != 0); 436 return s[0]; 437} 438 439/* 440 * security_dump_masked_av - dumps masked permissions during 441 * security_compute_av due to RBAC, MLS/Constraint and Type bounds. 442 */ 443static int dump_masked_av_helper(void *k, void *d, void *args) 444{ 445 struct perm_datum *pdatum = d; 446 char **permission_names = args; 447 448 BUG_ON(pdatum->value < 1 || pdatum->value > 32); 449 450 permission_names[pdatum->value - 1] = (char *)k; 451 452 return 0; 453} 454 455static void security_dump_masked_av(struct policydb *policydb, 456 struct context *scontext, 457 struct context *tcontext, 458 u16 tclass, 459 u32 permissions, 460 const char *reason) 461{ 462 struct common_datum *common_dat; 463 struct class_datum *tclass_dat; 464 struct audit_buffer *ab; 465 char *tclass_name; 466 char *scontext_name = NULL; 467 char *tcontext_name = NULL; 468 char *permission_names[32]; 469 int index; 470 u32 length; 471 bool need_comma = false; 472 473 if (!permissions) 474 return; 475 476 tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); 477 tclass_dat = policydb->class_val_to_struct[tclass - 1]; 478 common_dat = tclass_dat->comdatum; 479 480 /* init permission_names */ 481 if (common_dat && 482 hashtab_map(&common_dat->permissions.table, 483 dump_masked_av_helper, permission_names) < 0) 484 goto out; 485 486 if (hashtab_map(&tclass_dat->permissions.table, 487 dump_masked_av_helper, permission_names) < 0) 488 goto out; 489 490 /* get scontext/tcontext in text form */ 491 if (context_struct_to_string(policydb, scontext, 492 &scontext_name, &length) < 0) 493 goto out; 494 495 if (context_struct_to_string(policydb, tcontext, 496 &tcontext_name, &length) < 0) 497 goto out; 498 499 /* audit a message */ 500 ab = audit_log_start(audit_context(), 501 GFP_ATOMIC, AUDIT_SELINUX_ERR); 502 if (!ab) 503 goto out; 504 505 audit_log_format(ab, "op=security_compute_av reason=%s " 506 "scontext=%s tcontext=%s tclass=%s perms=", 507 reason, scontext_name, tcontext_name, tclass_name); 508 509 for (index = 0; index < 32; index++) { 510 u32 mask = (1 << index); 511 512 if ((mask & permissions) == 0) 513 continue; 514 515 audit_log_format(ab, "%s%s", 516 need_comma ? "," : "", 517 permission_names[index] 518 ? permission_names[index] : "????"); 519 need_comma = true; 520 } 521 audit_log_end(ab); 522out: 523 /* release scontext/tcontext */ 524 kfree(tcontext_name); 525 kfree(scontext_name); 526} 527 528/* 529 * security_boundary_permission - drops violated permissions 530 * on boundary constraint. 531 */ 532static void type_attribute_bounds_av(struct policydb *policydb, 533 struct context *scontext, 534 struct context *tcontext, 535 u16 tclass, 536 struct av_decision *avd) 537{ 538 struct context lo_scontext; 539 struct context lo_tcontext, *tcontextp = tcontext; 540 struct av_decision lo_avd; 541 struct type_datum *source; 542 struct type_datum *target; 543 u32 masked = 0; 544 545 source = policydb->type_val_to_struct[scontext->type - 1]; 546 BUG_ON(!source); 547 548 if (!source->bounds) 549 return; 550 551 target = policydb->type_val_to_struct[tcontext->type - 1]; 552 BUG_ON(!target); 553 554 memset(&lo_avd, 0, sizeof(lo_avd)); 555 556 memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); 557 lo_scontext.type = source->bounds; 558 559 if (target->bounds) { 560 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); 561 lo_tcontext.type = target->bounds; 562 tcontextp = &lo_tcontext; 563 } 564 565 context_struct_compute_av(policydb, &lo_scontext, 566 tcontextp, 567 tclass, 568 &lo_avd, 569 NULL); 570 571 masked = ~lo_avd.allowed & avd->allowed; 572 573 if (likely(!masked)) 574 return; /* no masked permission */ 575 576 /* mask violated permissions */ 577 avd->allowed &= ~masked; 578 579 /* audit masked permissions */ 580 security_dump_masked_av(policydb, scontext, tcontext, 581 tclass, masked, "bounds"); 582} 583 584/* 585 * flag which drivers have permissions 586 * only looking for ioctl based extended permissions 587 */ 588void services_compute_xperms_drivers( 589 struct extended_perms *xperms, 590 struct avtab_node *node) 591{ 592 unsigned int i; 593 594 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 595 /* if one or more driver has all permissions allowed */ 596 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) 597 xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; 598 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 599 /* if allowing permissions within a driver */ 600 security_xperm_set(xperms->drivers.p, 601 node->datum.u.xperms->driver); 602 } 603 604 xperms->len = 1; 605} 606 607/* 608 * Compute access vectors and extended permissions based on a context 609 * structure pair for the permissions in a particular class. 610 */ 611static void context_struct_compute_av(struct policydb *policydb, 612 struct context *scontext, 613 struct context *tcontext, 614 u16 tclass, 615 struct av_decision *avd, 616 struct extended_perms *xperms) 617{ 618 struct constraint_node *constraint; 619 struct role_allow *ra; 620 struct avtab_key avkey; 621 struct avtab_node *node; 622 struct class_datum *tclass_datum; 623 struct ebitmap *sattr, *tattr; 624 struct ebitmap_node *snode, *tnode; 625 unsigned int i, j; 626 627 avd->allowed = 0; 628 avd->auditallow = 0; 629 avd->auditdeny = 0xffffffff; 630 if (xperms) { 631 memset(&xperms->drivers, 0, sizeof(xperms->drivers)); 632 xperms->len = 0; 633 } 634 635 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 636 if (printk_ratelimit()) 637 pr_warn("SELinux: Invalid class %hu\n", tclass); 638 return; 639 } 640 641 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 642 643 /* 644 * If a specific type enforcement rule was defined for 645 * this permission check, then use it. 646 */ 647 avkey.target_class = tclass; 648 avkey.specified = AVTAB_AV | AVTAB_XPERMS; 649 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 650 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 651 ebitmap_for_each_positive_bit(sattr, snode, i) { 652 ebitmap_for_each_positive_bit(tattr, tnode, j) { 653 avkey.source_type = i + 1; 654 avkey.target_type = j + 1; 655 for (node = avtab_search_node(&policydb->te_avtab, 656 &avkey); 657 node; 658 node = avtab_search_node_next(node, avkey.specified)) { 659 if (node->key.specified == AVTAB_ALLOWED) 660 avd->allowed |= node->datum.u.data; 661 else if (node->key.specified == AVTAB_AUDITALLOW) 662 avd->auditallow |= node->datum.u.data; 663 else if (node->key.specified == AVTAB_AUDITDENY) 664 avd->auditdeny &= node->datum.u.data; 665 else if (xperms && (node->key.specified & AVTAB_XPERMS)) 666 services_compute_xperms_drivers(xperms, node); 667 } 668 669 /* Check conditional av table for additional permissions */ 670 cond_compute_av(&policydb->te_cond_avtab, &avkey, 671 avd, xperms); 672 673 } 674 } 675 676 /* 677 * Remove any permissions prohibited by a constraint (this includes 678 * the MLS policy). 679 */ 680 constraint = tclass_datum->constraints; 681 while (constraint) { 682 if ((constraint->permissions & (avd->allowed)) && 683 !constraint_expr_eval(policydb, scontext, tcontext, NULL, 684 constraint->expr)) { 685 avd->allowed &= ~(constraint->permissions); 686 } 687 constraint = constraint->next; 688 } 689 690 /* 691 * If checking process transition permission and the 692 * role is changing, then check the (current_role, new_role) 693 * pair. 694 */ 695 if (tclass == policydb->process_class && 696 (avd->allowed & policydb->process_trans_perms) && 697 scontext->role != tcontext->role) { 698 for (ra = policydb->role_allow; ra; ra = ra->next) { 699 if (scontext->role == ra->role && 700 tcontext->role == ra->new_role) 701 break; 702 } 703 if (!ra) 704 avd->allowed &= ~policydb->process_trans_perms; 705 } 706 707 /* 708 * If the given source and target types have boundary 709 * constraint, lazy checks have to mask any violated 710 * permission and notice it to userspace via audit. 711 */ 712 type_attribute_bounds_av(policydb, scontext, tcontext, 713 tclass, avd); 714} 715 716static int security_validtrans_handle_fail(struct selinux_policy *policy, 717 struct sidtab_entry *oentry, 718 struct sidtab_entry *nentry, 719 struct sidtab_entry *tentry, 720 u16 tclass) 721{ 722 struct policydb *p = &policy->policydb; 723 struct sidtab *sidtab = policy->sidtab; 724 char *o = NULL, *n = NULL, *t = NULL; 725 u32 olen, nlen, tlen; 726 727 if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) 728 goto out; 729 if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) 730 goto out; 731 if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) 732 goto out; 733 audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, 734 "op=security_validate_transition seresult=denied" 735 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 736 o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); 737out: 738 kfree(o); 739 kfree(n); 740 kfree(t); 741 742 if (!enforcing_enabled()) 743 return 0; 744 return -EPERM; 745} 746 747static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid, 748 u16 orig_tclass, bool user) 749{ 750 struct selinux_policy *policy; 751 struct policydb *policydb; 752 struct sidtab *sidtab; 753 struct sidtab_entry *oentry; 754 struct sidtab_entry *nentry; 755 struct sidtab_entry *tentry; 756 struct class_datum *tclass_datum; 757 struct constraint_node *constraint; 758 u16 tclass; 759 int rc = 0; 760 761 762 if (!selinux_initialized()) 763 return 0; 764 765 rcu_read_lock(); 766 767 policy = rcu_dereference(selinux_state.policy); 768 policydb = &policy->policydb; 769 sidtab = policy->sidtab; 770 771 if (!user) 772 tclass = unmap_class(&policy->map, orig_tclass); 773 else 774 tclass = orig_tclass; 775 776 if (!tclass || tclass > policydb->p_classes.nprim) { 777 rc = -EINVAL; 778 goto out; 779 } 780 tclass_datum = policydb->class_val_to_struct[tclass - 1]; 781 782 oentry = sidtab_search_entry(sidtab, oldsid); 783 if (!oentry) { 784 pr_err("SELinux: %s: unrecognized SID %d\n", 785 __func__, oldsid); 786 rc = -EINVAL; 787 goto out; 788 } 789 790 nentry = sidtab_search_entry(sidtab, newsid); 791 if (!nentry) { 792 pr_err("SELinux: %s: unrecognized SID %d\n", 793 __func__, newsid); 794 rc = -EINVAL; 795 goto out; 796 } 797 798 tentry = sidtab_search_entry(sidtab, tasksid); 799 if (!tentry) { 800 pr_err("SELinux: %s: unrecognized SID %d\n", 801 __func__, tasksid); 802 rc = -EINVAL; 803 goto out; 804 } 805 806 constraint = tclass_datum->validatetrans; 807 while (constraint) { 808 if (!constraint_expr_eval(policydb, &oentry->context, 809 &nentry->context, &tentry->context, 810 constraint->expr)) { 811 if (user) 812 rc = -EPERM; 813 else 814 rc = security_validtrans_handle_fail(policy, 815 oentry, 816 nentry, 817 tentry, 818 tclass); 819 goto out; 820 } 821 constraint = constraint->next; 822 } 823 824out: 825 rcu_read_unlock(); 826 return rc; 827} 828 829int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid, 830 u16 tclass) 831{ 832 return security_compute_validatetrans(oldsid, newsid, tasksid, 833 tclass, true); 834} 835 836int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 837 u16 orig_tclass) 838{ 839 return security_compute_validatetrans(oldsid, newsid, tasksid, 840 orig_tclass, false); 841} 842 843/* 844 * security_bounded_transition - check whether the given 845 * transition is directed to bounded, or not. 846 * It returns 0, if @newsid is bounded by @oldsid. 847 * Otherwise, it returns error code. 848 * 849 * @oldsid : current security identifier 850 * @newsid : destinated security identifier 851 */ 852int security_bounded_transition(u32 old_sid, u32 new_sid) 853{ 854 struct selinux_policy *policy; 855 struct policydb *policydb; 856 struct sidtab *sidtab; 857 struct sidtab_entry *old_entry, *new_entry; 858 struct type_datum *type; 859 u32 index; 860 int rc; 861 862 if (!selinux_initialized()) 863 return 0; 864 865 rcu_read_lock(); 866 policy = rcu_dereference(selinux_state.policy); 867 policydb = &policy->policydb; 868 sidtab = policy->sidtab; 869 870 rc = -EINVAL; 871 old_entry = sidtab_search_entry(sidtab, old_sid); 872 if (!old_entry) { 873 pr_err("SELinux: %s: unrecognized SID %u\n", 874 __func__, old_sid); 875 goto out; 876 } 877 878 rc = -EINVAL; 879 new_entry = sidtab_search_entry(sidtab, new_sid); 880 if (!new_entry) { 881 pr_err("SELinux: %s: unrecognized SID %u\n", 882 __func__, new_sid); 883 goto out; 884 } 885 886 rc = 0; 887 /* type/domain unchanged */ 888 if (old_entry->context.type == new_entry->context.type) 889 goto out; 890 891 index = new_entry->context.type; 892 while (true) { 893 type = policydb->type_val_to_struct[index - 1]; 894 BUG_ON(!type); 895 896 /* not bounded anymore */ 897 rc = -EPERM; 898 if (!type->bounds) 899 break; 900 901 /* @newsid is bounded by @oldsid */ 902 rc = 0; 903 if (type->bounds == old_entry->context.type) 904 break; 905 906 index = type->bounds; 907 } 908 909 if (rc) { 910 char *old_name = NULL; 911 char *new_name = NULL; 912 u32 length; 913 914 if (!sidtab_entry_to_string(policydb, sidtab, old_entry, 915 &old_name, &length) && 916 !sidtab_entry_to_string(policydb, sidtab, new_entry, 917 &new_name, &length)) { 918 audit_log(audit_context(), 919 GFP_ATOMIC, AUDIT_SELINUX_ERR, 920 "op=security_bounded_transition " 921 "seresult=denied " 922 "oldcontext=%s newcontext=%s", 923 old_name, new_name); 924 } 925 kfree(new_name); 926 kfree(old_name); 927 } 928out: 929 rcu_read_unlock(); 930 931 return rc; 932} 933 934static void avd_init(struct selinux_policy *policy, struct av_decision *avd) 935{ 936 avd->allowed = 0; 937 avd->auditallow = 0; 938 avd->auditdeny = 0xffffffff; 939 if (policy) 940 avd->seqno = policy->latest_granting; 941 else 942 avd->seqno = 0; 943 avd->flags = 0; 944} 945 946void services_compute_xperms_decision(struct extended_perms_decision *xpermd, 947 struct avtab_node *node) 948{ 949 unsigned int i; 950 951 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 952 if (xpermd->driver != node->datum.u.xperms->driver) 953 return; 954 } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 955 if (!security_xperm_test(node->datum.u.xperms->perms.p, 956 xpermd->driver)) 957 return; 958 } else { 959 BUG(); 960 } 961 962 if (node->key.specified == AVTAB_XPERMS_ALLOWED) { 963 xpermd->used |= XPERMS_ALLOWED; 964 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 965 memset(xpermd->allowed->p, 0xff, 966 sizeof(xpermd->allowed->p)); 967 } 968 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 969 for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) 970 xpermd->allowed->p[i] |= 971 node->datum.u.xperms->perms.p[i]; 972 } 973 } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { 974 xpermd->used |= XPERMS_AUDITALLOW; 975 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 976 memset(xpermd->auditallow->p, 0xff, 977 sizeof(xpermd->auditallow->p)); 978 } 979 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 980 for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) 981 xpermd->auditallow->p[i] |= 982 node->datum.u.xperms->perms.p[i]; 983 } 984 } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { 985 xpermd->used |= XPERMS_DONTAUDIT; 986 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { 987 memset(xpermd->dontaudit->p, 0xff, 988 sizeof(xpermd->dontaudit->p)); 989 } 990 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { 991 for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) 992 xpermd->dontaudit->p[i] |= 993 node->datum.u.xperms->perms.p[i]; 994 } 995 } else { 996 BUG(); 997 } 998} 999 1000void security_compute_xperms_decision(u32 ssid, 1001 u32 tsid, 1002 u16 orig_tclass, 1003 u8 driver, 1004 struct extended_perms_decision *xpermd) 1005{ 1006 struct selinux_policy *policy; 1007 struct policydb *policydb; 1008 struct sidtab *sidtab; 1009 u16 tclass; 1010 struct context *scontext, *tcontext; 1011 struct avtab_key avkey; 1012 struct avtab_node *node; 1013 struct ebitmap *sattr, *tattr; 1014 struct ebitmap_node *snode, *tnode; 1015 unsigned int i, j; 1016 1017 xpermd->driver = driver; 1018 xpermd->used = 0; 1019 memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); 1020 memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); 1021 memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); 1022 1023 rcu_read_lock(); 1024 if (!selinux_initialized()) 1025 goto allow; 1026 1027 policy = rcu_dereference(selinux_state.policy); 1028 policydb = &policy->policydb; 1029 sidtab = policy->sidtab; 1030 1031 scontext = sidtab_search(sidtab, ssid); 1032 if (!scontext) { 1033 pr_err("SELinux: %s: unrecognized SID %d\n", 1034 __func__, ssid); 1035 goto out; 1036 } 1037 1038 tcontext = sidtab_search(sidtab, tsid); 1039 if (!tcontext) { 1040 pr_err("SELinux: %s: unrecognized SID %d\n", 1041 __func__, tsid); 1042 goto out; 1043 } 1044 1045 tclass = unmap_class(&policy->map, orig_tclass); 1046 if (unlikely(orig_tclass && !tclass)) { 1047 if (policydb->allow_unknown) 1048 goto allow; 1049 goto out; 1050 } 1051 1052 1053 if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { 1054 pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); 1055 goto out; 1056 } 1057 1058 avkey.target_class = tclass; 1059 avkey.specified = AVTAB_XPERMS; 1060 sattr = &policydb->type_attr_map_array[scontext->type - 1]; 1061 tattr = &policydb->type_attr_map_array[tcontext->type - 1]; 1062 ebitmap_for_each_positive_bit(sattr, snode, i) { 1063 ebitmap_for_each_positive_bit(tattr, tnode, j) { 1064 avkey.source_type = i + 1; 1065 avkey.target_type = j + 1; 1066 for (node = avtab_search_node(&policydb->te_avtab, 1067 &avkey); 1068 node; 1069 node = avtab_search_node_next(node, avkey.specified)) 1070 services_compute_xperms_decision(xpermd, node); 1071 1072 cond_compute_xperms(&policydb->te_cond_avtab, 1073 &avkey, xpermd); 1074 } 1075 } 1076out: 1077 rcu_read_unlock(); 1078 return; 1079allow: 1080 memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); 1081 goto out; 1082} 1083 1084/** 1085 * security_compute_av - Compute access vector decisions. 1086 * @ssid: source security identifier 1087 * @tsid: target security identifier 1088 * @orig_tclass: target security class 1089 * @avd: access vector decisions 1090 * @xperms: extended permissions 1091 * 1092 * Compute a set of access vector decisions based on the 1093 * SID pair (@ssid, @tsid) for the permissions in @tclass. 1094 */ 1095void security_compute_av(u32 ssid, 1096 u32 tsid, 1097 u16 orig_tclass, 1098 struct av_decision *avd, 1099 struct extended_perms *xperms) 1100{ 1101 struct selinux_policy *policy; 1102 struct policydb *policydb; 1103 struct sidtab *sidtab; 1104 u16 tclass; 1105 struct context *scontext = NULL, *tcontext = NULL; 1106 1107 rcu_read_lock(); 1108 policy = rcu_dereference(selinux_state.policy); 1109 avd_init(policy, avd); 1110 xperms->len = 0; 1111 if (!selinux_initialized()) 1112 goto allow; 1113 1114 policydb = &policy->policydb; 1115 sidtab = policy->sidtab; 1116 1117 scontext = sidtab_search(sidtab, ssid); 1118 if (!scontext) { 1119 pr_err("SELinux: %s: unrecognized SID %d\n", 1120 __func__, ssid); 1121 goto out; 1122 } 1123 1124 /* permissive domain? */ 1125 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1126 avd->flags |= AVD_FLAGS_PERMISSIVE; 1127 1128 tcontext = sidtab_search(sidtab, tsid); 1129 if (!tcontext) { 1130 pr_err("SELinux: %s: unrecognized SID %d\n", 1131 __func__, tsid); 1132 goto out; 1133 } 1134 1135 tclass = unmap_class(&policy->map, orig_tclass); 1136 if (unlikely(orig_tclass && !tclass)) { 1137 if (policydb->allow_unknown) 1138 goto allow; 1139 goto out; 1140 } 1141 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1142 xperms); 1143 map_decision(&policy->map, orig_tclass, avd, 1144 policydb->allow_unknown); 1145out: 1146 rcu_read_unlock(); 1147 return; 1148allow: 1149 avd->allowed = 0xffffffff; 1150 goto out; 1151} 1152 1153void security_compute_av_user(u32 ssid, 1154 u32 tsid, 1155 u16 tclass, 1156 struct av_decision *avd) 1157{ 1158 struct selinux_policy *policy; 1159 struct policydb *policydb; 1160 struct sidtab *sidtab; 1161 struct context *scontext = NULL, *tcontext = NULL; 1162 1163 rcu_read_lock(); 1164 policy = rcu_dereference(selinux_state.policy); 1165 avd_init(policy, avd); 1166 if (!selinux_initialized()) 1167 goto allow; 1168 1169 policydb = &policy->policydb; 1170 sidtab = policy->sidtab; 1171 1172 scontext = sidtab_search(sidtab, ssid); 1173 if (!scontext) { 1174 pr_err("SELinux: %s: unrecognized SID %d\n", 1175 __func__, ssid); 1176 goto out; 1177 } 1178 1179 /* permissive domain? */ 1180 if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) 1181 avd->flags |= AVD_FLAGS_PERMISSIVE; 1182 1183 tcontext = sidtab_search(sidtab, tsid); 1184 if (!tcontext) { 1185 pr_err("SELinux: %s: unrecognized SID %d\n", 1186 __func__, tsid); 1187 goto out; 1188 } 1189 1190 if (unlikely(!tclass)) { 1191 if (policydb->allow_unknown) 1192 goto allow; 1193 goto out; 1194 } 1195 1196 context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, 1197 NULL); 1198 out: 1199 rcu_read_unlock(); 1200 return; 1201allow: 1202 avd->allowed = 0xffffffff; 1203 goto out; 1204} 1205 1206/* 1207 * Write the security context string representation of 1208 * the context structure `context' into a dynamically 1209 * allocated string of the correct size. Set `*scontext' 1210 * to point to this string and set `*scontext_len' to 1211 * the length of the string. 1212 */ 1213static int context_struct_to_string(struct policydb *p, 1214 struct context *context, 1215 char **scontext, u32 *scontext_len) 1216{ 1217 char *scontextp; 1218 1219 if (scontext) 1220 *scontext = NULL; 1221 *scontext_len = 0; 1222 1223 if (context->len) { 1224 *scontext_len = context->len; 1225 if (scontext) { 1226 *scontext = kstrdup(context->str, GFP_ATOMIC); 1227 if (!(*scontext)) 1228 return -ENOMEM; 1229 } 1230 return 0; 1231 } 1232 1233 /* Compute the size of the context. */ 1234 *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; 1235 *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; 1236 *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; 1237 *scontext_len += mls_compute_context_len(p, context); 1238 1239 if (!scontext) 1240 return 0; 1241 1242 /* Allocate space for the context; caller must free this space. */ 1243 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 1244 if (!scontextp) 1245 return -ENOMEM; 1246 *scontext = scontextp; 1247 1248 /* 1249 * Copy the user name, role name and type name into the context. 1250 */ 1251 scontextp += sprintf(scontextp, "%s:%s:%s", 1252 sym_name(p, SYM_USERS, context->user - 1), 1253 sym_name(p, SYM_ROLES, context->role - 1), 1254 sym_name(p, SYM_TYPES, context->type - 1)); 1255 1256 mls_sid_to_context(p, context, &scontextp); 1257 1258 *scontextp = 0; 1259 1260 return 0; 1261} 1262 1263static int sidtab_entry_to_string(struct policydb *p, 1264 struct sidtab *sidtab, 1265 struct sidtab_entry *entry, 1266 char **scontext, u32 *scontext_len) 1267{ 1268 int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); 1269 1270 if (rc != -ENOENT) 1271 return rc; 1272 1273 rc = context_struct_to_string(p, &entry->context, scontext, 1274 scontext_len); 1275 if (!rc && scontext) 1276 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); 1277 return rc; 1278} 1279 1280#include "initial_sid_to_string.h" 1281 1282int security_sidtab_hash_stats(char *page) 1283{ 1284 struct selinux_policy *policy; 1285 int rc; 1286 1287 if (!selinux_initialized()) { 1288 pr_err("SELinux: %s: called before initial load_policy\n", 1289 __func__); 1290 return -EINVAL; 1291 } 1292 1293 rcu_read_lock(); 1294 policy = rcu_dereference(selinux_state.policy); 1295 rc = sidtab_hash_stats(policy->sidtab, page); 1296 rcu_read_unlock(); 1297 1298 return rc; 1299} 1300 1301const char *security_get_initial_sid_context(u32 sid) 1302{ 1303 if (unlikely(sid > SECINITSID_NUM)) 1304 return NULL; 1305 return initial_sid_to_string[sid]; 1306} 1307 1308static int security_sid_to_context_core(u32 sid, char **scontext, 1309 u32 *scontext_len, int force, 1310 int only_invalid) 1311{ 1312 struct selinux_policy *policy; 1313 struct policydb *policydb; 1314 struct sidtab *sidtab; 1315 struct sidtab_entry *entry; 1316 int rc = 0; 1317 1318 if (scontext) 1319 *scontext = NULL; 1320 *scontext_len = 0; 1321 1322 if (!selinux_initialized()) { 1323 if (sid <= SECINITSID_NUM) { 1324 char *scontextp; 1325 const char *s = initial_sid_to_string[sid]; 1326 1327 if (!s) 1328 return -EINVAL; 1329 *scontext_len = strlen(s) + 1; 1330 if (!scontext) 1331 return 0; 1332 scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); 1333 if (!scontextp) 1334 return -ENOMEM; 1335 *scontext = scontextp; 1336 return 0; 1337 } 1338 pr_err("SELinux: %s: called before initial " 1339 "load_policy on unknown SID %d\n", __func__, sid); 1340 return -EINVAL; 1341 } 1342 rcu_read_lock(); 1343 policy = rcu_dereference(selinux_state.policy); 1344 policydb = &policy->policydb; 1345 sidtab = policy->sidtab; 1346 1347 if (force) 1348 entry = sidtab_search_entry_force(sidtab, sid); 1349 else 1350 entry = sidtab_search_entry(sidtab, sid); 1351 if (!entry) { 1352 pr_err("SELinux: %s: unrecognized SID %d\n", 1353 __func__, sid); 1354 rc = -EINVAL; 1355 goto out_unlock; 1356 } 1357 if (only_invalid && !entry->context.len) 1358 goto out_unlock; 1359 1360 rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, 1361 scontext_len); 1362 1363out_unlock: 1364 rcu_read_unlock(); 1365 return rc; 1366 1367} 1368 1369/** 1370 * security_sid_to_context - Obtain a context for a given SID. 1371 * @sid: security identifier, SID 1372 * @scontext: security context 1373 * @scontext_len: length in bytes 1374 * 1375 * Write the string representation of the context associated with @sid 1376 * into a dynamically allocated string of the correct size. Set @scontext 1377 * to point to this string and set @scontext_len to the length of the string. 1378 */ 1379int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 1380{ 1381 return security_sid_to_context_core(sid, scontext, 1382 scontext_len, 0, 0); 1383} 1384 1385int security_sid_to_context_force(u32 sid, 1386 char **scontext, u32 *scontext_len) 1387{ 1388 return security_sid_to_context_core(sid, scontext, 1389 scontext_len, 1, 0); 1390} 1391 1392/** 1393 * security_sid_to_context_inval - Obtain a context for a given SID if it 1394 * is invalid. 1395 * @sid: security identifier, SID 1396 * @scontext: security context 1397 * @scontext_len: length in bytes 1398 * 1399 * Write the string representation of the context associated with @sid 1400 * into a dynamically allocated string of the correct size, but only if the 1401 * context is invalid in the current policy. Set @scontext to point to 1402 * this string (or NULL if the context is valid) and set @scontext_len to 1403 * the length of the string (or 0 if the context is valid). 1404 */ 1405int security_sid_to_context_inval(u32 sid, 1406 char **scontext, u32 *scontext_len) 1407{ 1408 return security_sid_to_context_core(sid, scontext, 1409 scontext_len, 1, 1); 1410} 1411 1412/* 1413 * Caveat: Mutates scontext. 1414 */ 1415static int string_to_context_struct(struct policydb *pol, 1416 struct sidtab *sidtabp, 1417 char *scontext, 1418 struct context *ctx, 1419 u32 def_sid) 1420{ 1421 struct role_datum *role; 1422 struct type_datum *typdatum; 1423 struct user_datum *usrdatum; 1424 char *scontextp, *p, oldc; 1425 int rc = 0; 1426 1427 context_init(ctx); 1428 1429 /* Parse the security context. */ 1430 1431 rc = -EINVAL; 1432 scontextp = scontext; 1433 1434 /* Extract the user. */ 1435 p = scontextp; 1436 while (*p && *p != ':') 1437 p++; 1438 1439 if (*p == 0) 1440 goto out; 1441 1442 *p++ = 0; 1443 1444 usrdatum = symtab_search(&pol->p_users, scontextp); 1445 if (!usrdatum) 1446 goto out; 1447 1448 ctx->user = usrdatum->value; 1449 1450 /* Extract role. */ 1451 scontextp = p; 1452 while (*p && *p != ':') 1453 p++; 1454 1455 if (*p == 0) 1456 goto out; 1457 1458 *p++ = 0; 1459 1460 role = symtab_search(&pol->p_roles, scontextp); 1461 if (!role) 1462 goto out; 1463 ctx->role = role->value; 1464 1465 /* Extract type. */ 1466 scontextp = p; 1467 while (*p && *p != ':') 1468 p++; 1469 oldc = *p; 1470 *p++ = 0; 1471 1472 typdatum = symtab_search(&pol->p_types, scontextp); 1473 if (!typdatum || typdatum->attribute) 1474 goto out; 1475 1476 ctx->type = typdatum->value; 1477 1478 rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); 1479 if (rc) 1480 goto out; 1481 1482 /* Check the validity of the new context. */ 1483 rc = -EINVAL; 1484 if (!policydb_context_isvalid(pol, ctx)) 1485 goto out; 1486 rc = 0; 1487out: 1488 if (rc) 1489 context_destroy(ctx); 1490 return rc; 1491} 1492 1493static int security_context_to_sid_core(const char *scontext, u32 scontext_len, 1494 u32 *sid, u32 def_sid, gfp_t gfp_flags, 1495 int force) 1496{ 1497 struct selinux_policy *policy; 1498 struct policydb *policydb; 1499 struct sidtab *sidtab; 1500 char *scontext2, *str = NULL; 1501 struct context context; 1502 int rc = 0; 1503 1504 /* An empty security context is never valid. */ 1505 if (!scontext_len) 1506 return -EINVAL; 1507 1508 /* Copy the string to allow changes and ensure a NUL terminator */ 1509 scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); 1510 if (!scontext2) 1511 return -ENOMEM; 1512 1513 if (!selinux_initialized()) { 1514 u32 i; 1515 1516 for (i = 1; i < SECINITSID_NUM; i++) { 1517 const char *s = initial_sid_to_string[i]; 1518 1519 if (s && !strcmp(s, scontext2)) { 1520 *sid = i; 1521 goto out; 1522 } 1523 } 1524 *sid = SECINITSID_KERNEL; 1525 goto out; 1526 } 1527 *sid = SECSID_NULL; 1528 1529 if (force) { 1530 /* Save another copy for storing in uninterpreted form */ 1531 rc = -ENOMEM; 1532 str = kstrdup(scontext2, gfp_flags); 1533 if (!str) 1534 goto out; 1535 } 1536retry: 1537 rcu_read_lock(); 1538 policy = rcu_dereference(selinux_state.policy); 1539 policydb = &policy->policydb; 1540 sidtab = policy->sidtab; 1541 rc = string_to_context_struct(policydb, sidtab, scontext2, 1542 &context, def_sid); 1543 if (rc == -EINVAL && force) { 1544 context.str = str; 1545 context.len = strlen(str) + 1; 1546 str = NULL; 1547 } else if (rc) 1548 goto out_unlock; 1549 rc = sidtab_context_to_sid(sidtab, &context, sid); 1550 if (rc == -ESTALE) { 1551 rcu_read_unlock(); 1552 if (context.str) { 1553 str = context.str; 1554 context.str = NULL; 1555 } 1556 context_destroy(&context); 1557 goto retry; 1558 } 1559 context_destroy(&context); 1560out_unlock: 1561 rcu_read_unlock(); 1562out: 1563 kfree(scontext2); 1564 kfree(str); 1565 return rc; 1566} 1567 1568/** 1569 * security_context_to_sid - Obtain a SID for a given security context. 1570 * @scontext: security context 1571 * @scontext_len: length in bytes 1572 * @sid: security identifier, SID 1573 * @gfp: context for the allocation 1574 * 1575 * Obtains a SID associated with the security context that 1576 * has the string representation specified by @scontext. 1577 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1578 * memory is available, or 0 on success. 1579 */ 1580int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid, 1581 gfp_t gfp) 1582{ 1583 return security_context_to_sid_core(scontext, scontext_len, 1584 sid, SECSID_NULL, gfp, 0); 1585} 1586 1587int security_context_str_to_sid(const char *scontext, u32 *sid, gfp_t gfp) 1588{ 1589 return security_context_to_sid(scontext, strlen(scontext), 1590 sid, gfp); 1591} 1592 1593/** 1594 * security_context_to_sid_default - Obtain a SID for a given security context, 1595 * falling back to specified default if needed. 1596 * 1597 * @scontext: security context 1598 * @scontext_len: length in bytes 1599 * @sid: security identifier, SID 1600 * @def_sid: default SID to assign on error 1601 * @gfp_flags: the allocator get-free-page (GFP) flags 1602 * 1603 * Obtains a SID associated with the security context that 1604 * has the string representation specified by @scontext. 1605 * The default SID is passed to the MLS layer to be used to allow 1606 * kernel labeling of the MLS field if the MLS field is not present 1607 * (for upgrading to MLS without full relabel). 1608 * Implicitly forces adding of the context even if it cannot be mapped yet. 1609 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 1610 * memory is available, or 0 on success. 1611 */ 1612int security_context_to_sid_default(const char *scontext, u32 scontext_len, 1613 u32 *sid, u32 def_sid, gfp_t gfp_flags) 1614{ 1615 return security_context_to_sid_core(scontext, scontext_len, 1616 sid, def_sid, gfp_flags, 1); 1617} 1618 1619int security_context_to_sid_force(const char *scontext, u32 scontext_len, 1620 u32 *sid) 1621{ 1622 return security_context_to_sid_core(scontext, scontext_len, 1623 sid, SECSID_NULL, GFP_KERNEL, 1); 1624} 1625 1626static int compute_sid_handle_invalid_context( 1627 struct selinux_policy *policy, 1628 struct sidtab_entry *sentry, 1629 struct sidtab_entry *tentry, 1630 u16 tclass, 1631 struct context *newcontext) 1632{ 1633 struct policydb *policydb = &policy->policydb; 1634 struct sidtab *sidtab = policy->sidtab; 1635 char *s = NULL, *t = NULL, *n = NULL; 1636 u32 slen, tlen, nlen; 1637 struct audit_buffer *ab; 1638 1639 if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) 1640 goto out; 1641 if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) 1642 goto out; 1643 if (context_struct_to_string(policydb, newcontext, &n, &nlen)) 1644 goto out; 1645 ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); 1646 if (!ab) 1647 goto out; 1648 audit_log_format(ab, 1649 "op=security_compute_sid invalid_context="); 1650 /* no need to record the NUL with untrusted strings */ 1651 audit_log_n_untrustedstring(ab, n, nlen - 1); 1652 audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", 1653 s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); 1654 audit_log_end(ab); 1655out: 1656 kfree(s); 1657 kfree(t); 1658 kfree(n); 1659 if (!enforcing_enabled()) 1660 return 0; 1661 return -EACCES; 1662} 1663 1664static void filename_compute_type(struct policydb *policydb, 1665 struct context *newcontext, 1666 u32 stype, u32 ttype, u16 tclass, 1667 const char *objname) 1668{ 1669 struct filename_trans_key ft; 1670 struct filename_trans_datum *datum; 1671 1672 /* 1673 * Most filename trans rules are going to live in specific directories 1674 * like /dev or /var/run. This bitmap will quickly skip rule searches 1675 * if the ttype does not contain any rules. 1676 */ 1677 if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) 1678 return; 1679 1680 ft.ttype = ttype; 1681 ft.tclass = tclass; 1682 ft.name = objname; 1683 1684 datum = policydb_filenametr_search(policydb, &ft); 1685 while (datum) { 1686 if (ebitmap_get_bit(&datum->stypes, stype - 1)) { 1687 newcontext->type = datum->otype; 1688 return; 1689 } 1690 datum = datum->next; 1691 } 1692} 1693 1694static int security_compute_sid(u32 ssid, 1695 u32 tsid, 1696 u16 orig_tclass, 1697 u16 specified, 1698 const char *objname, 1699 u32 *out_sid, 1700 bool kern) 1701{ 1702 struct selinux_policy *policy; 1703 struct policydb *policydb; 1704 struct sidtab *sidtab; 1705 struct class_datum *cladatum; 1706 struct context *scontext, *tcontext, newcontext; 1707 struct sidtab_entry *sentry, *tentry; 1708 struct avtab_key avkey; 1709 struct avtab_node *avnode, *node; 1710 u16 tclass; 1711 int rc = 0; 1712 bool sock; 1713 1714 if (!selinux_initialized()) { 1715 switch (orig_tclass) { 1716 case SECCLASS_PROCESS: /* kernel value */ 1717 *out_sid = ssid; 1718 break; 1719 default: 1720 *out_sid = tsid; 1721 break; 1722 } 1723 goto out; 1724 } 1725 1726retry: 1727 cladatum = NULL; 1728 context_init(&newcontext); 1729 1730 rcu_read_lock(); 1731 1732 policy = rcu_dereference(selinux_state.policy); 1733 1734 if (kern) { 1735 tclass = unmap_class(&policy->map, orig_tclass); 1736 sock = security_is_socket_class(orig_tclass); 1737 } else { 1738 tclass = orig_tclass; 1739 sock = security_is_socket_class(map_class(&policy->map, 1740 tclass)); 1741 } 1742 1743 policydb = &policy->policydb; 1744 sidtab = policy->sidtab; 1745 1746 sentry = sidtab_search_entry(sidtab, ssid); 1747 if (!sentry) { 1748 pr_err("SELinux: %s: unrecognized SID %d\n", 1749 __func__, ssid); 1750 rc = -EINVAL; 1751 goto out_unlock; 1752 } 1753 tentry = sidtab_search_entry(sidtab, tsid); 1754 if (!tentry) { 1755 pr_err("SELinux: %s: unrecognized SID %d\n", 1756 __func__, tsid); 1757 rc = -EINVAL; 1758 goto out_unlock; 1759 } 1760 1761 scontext = &sentry->context; 1762 tcontext = &tentry->context; 1763 1764 if (tclass && tclass <= policydb->p_classes.nprim) 1765 cladatum = policydb->class_val_to_struct[tclass - 1]; 1766 1767 /* Set the user identity. */ 1768 switch (specified) { 1769 case AVTAB_TRANSITION: 1770 case AVTAB_CHANGE: 1771 if (cladatum && cladatum->default_user == DEFAULT_TARGET) { 1772 newcontext.user = tcontext->user; 1773 } else { 1774 /* notice this gets both DEFAULT_SOURCE and unset */ 1775 /* Use the process user identity. */ 1776 newcontext.user = scontext->user; 1777 } 1778 break; 1779 case AVTAB_MEMBER: 1780 /* Use the related object owner. */ 1781 newcontext.user = tcontext->user; 1782 break; 1783 } 1784 1785 /* Set the role to default values. */ 1786 if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { 1787 newcontext.role = scontext->role; 1788 } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { 1789 newcontext.role = tcontext->role; 1790 } else { 1791 if ((tclass == policydb->process_class) || sock) 1792 newcontext.role = scontext->role; 1793 else 1794 newcontext.role = OBJECT_R_VAL; 1795 } 1796 1797 /* Set the type to default values. */ 1798 if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { 1799 newcontext.type = scontext->type; 1800 } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { 1801 newcontext.type = tcontext->type; 1802 } else { 1803 if ((tclass == policydb->process_class) || sock) { 1804 /* Use the type of process. */ 1805 newcontext.type = scontext->type; 1806 } else { 1807 /* Use the type of the related object. */ 1808 newcontext.type = tcontext->type; 1809 } 1810 } 1811 1812 /* Look for a type transition/member/change rule. */ 1813 avkey.source_type = scontext->type; 1814 avkey.target_type = tcontext->type; 1815 avkey.target_class = tclass; 1816 avkey.specified = specified; 1817 avnode = avtab_search_node(&policydb->te_avtab, &avkey); 1818 1819 /* If no permanent rule, also check for enabled conditional rules */ 1820 if (!avnode) { 1821 node = avtab_search_node(&policydb->te_cond_avtab, &avkey); 1822 for (; node; node = avtab_search_node_next(node, specified)) { 1823 if (node->key.specified & AVTAB_ENABLED) { 1824 avnode = node; 1825 break; 1826 } 1827 } 1828 } 1829 1830 if (avnode) { 1831 /* Use the type from the type transition/member/change rule. */ 1832 newcontext.type = avnode->datum.u.data; 1833 } 1834 1835 /* if we have a objname this is a file trans check so check those rules */ 1836 if (objname) 1837 filename_compute_type(policydb, &newcontext, scontext->type, 1838 tcontext->type, tclass, objname); 1839 1840 /* Check for class-specific changes. */ 1841 if (specified & AVTAB_TRANSITION) { 1842 /* Look for a role transition rule. */ 1843 struct role_trans_datum *rtd; 1844 struct role_trans_key rtk = { 1845 .role = scontext->role, 1846 .type = tcontext->type, 1847 .tclass = tclass, 1848 }; 1849 1850 rtd = policydb_roletr_search(policydb, &rtk); 1851 if (rtd) 1852 newcontext.role = rtd->new_role; 1853 } 1854 1855 /* Set the MLS attributes. 1856 This is done last because it may allocate memory. */ 1857 rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, 1858 &newcontext, sock); 1859 if (rc) 1860 goto out_unlock; 1861 1862 /* Check the validity of the context. */ 1863 if (!policydb_context_isvalid(policydb, &newcontext)) { 1864 rc = compute_sid_handle_invalid_context(policy, sentry, 1865 tentry, tclass, 1866 &newcontext); 1867 if (rc) 1868 goto out_unlock; 1869 } 1870 /* Obtain the sid for the context. */ 1871 rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); 1872 if (rc == -ESTALE) { 1873 rcu_read_unlock(); 1874 context_destroy(&newcontext); 1875 goto retry; 1876 } 1877out_unlock: 1878 rcu_read_unlock(); 1879 context_destroy(&newcontext); 1880out: 1881 return rc; 1882} 1883 1884/** 1885 * security_transition_sid - Compute the SID for a new subject/object. 1886 * @ssid: source security identifier 1887 * @tsid: target security identifier 1888 * @tclass: target security class 1889 * @qstr: object name 1890 * @out_sid: security identifier for new subject/object 1891 * 1892 * Compute a SID to use for labeling a new subject or object in the 1893 * class @tclass based on a SID pair (@ssid, @tsid). 1894 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1895 * if insufficient memory is available, or %0 if the new SID was 1896 * computed successfully. 1897 */ 1898int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, 1899 const struct qstr *qstr, u32 *out_sid) 1900{ 1901 return security_compute_sid(ssid, tsid, tclass, 1902 AVTAB_TRANSITION, 1903 qstr ? qstr->name : NULL, out_sid, true); 1904} 1905 1906int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, 1907 const char *objname, u32 *out_sid) 1908{ 1909 return security_compute_sid(ssid, tsid, tclass, 1910 AVTAB_TRANSITION, 1911 objname, out_sid, false); 1912} 1913 1914/** 1915 * security_member_sid - Compute the SID for member selection. 1916 * @ssid: source security identifier 1917 * @tsid: target security identifier 1918 * @tclass: target security class 1919 * @out_sid: security identifier for selected member 1920 * 1921 * Compute a SID to use when selecting a member of a polyinstantiated 1922 * object of class @tclass based on a SID pair (@ssid, @tsid). 1923 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1924 * if insufficient memory is available, or %0 if the SID was 1925 * computed successfully. 1926 */ 1927int security_member_sid(u32 ssid, 1928 u32 tsid, 1929 u16 tclass, 1930 u32 *out_sid) 1931{ 1932 return security_compute_sid(ssid, tsid, tclass, 1933 AVTAB_MEMBER, NULL, 1934 out_sid, false); 1935} 1936 1937/** 1938 * security_change_sid - Compute the SID for object relabeling. 1939 * @ssid: source security identifier 1940 * @tsid: target security identifier 1941 * @tclass: target security class 1942 * @out_sid: security identifier for selected member 1943 * 1944 * Compute a SID to use for relabeling an object of class @tclass 1945 * based on a SID pair (@ssid, @tsid). 1946 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 1947 * if insufficient memory is available, or %0 if the SID was 1948 * computed successfully. 1949 */ 1950int security_change_sid(u32 ssid, 1951 u32 tsid, 1952 u16 tclass, 1953 u32 *out_sid) 1954{ 1955 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, 1956 out_sid, false); 1957} 1958 1959static inline int convert_context_handle_invalid_context( 1960 struct policydb *policydb, 1961 struct context *context) 1962{ 1963 char *s; 1964 u32 len; 1965 1966 if (enforcing_enabled()) 1967 return -EINVAL; 1968 1969 if (!context_struct_to_string(policydb, context, &s, &len)) { 1970 pr_warn("SELinux: Context %s would be invalid if enforcing\n", 1971 s); 1972 kfree(s); 1973 } 1974 return 0; 1975} 1976 1977/** 1978 * services_convert_context - Convert a security context across policies. 1979 * @args: populated convert_context_args struct 1980 * @oldc: original context 1981 * @newc: converted context 1982 * @gfp_flags: allocation flags 1983 * 1984 * Convert the values in the security context structure @oldc from the values 1985 * specified in the policy @args->oldp to the values specified in the policy 1986 * @args->newp, storing the new context in @newc, and verifying that the 1987 * context is valid under the new policy. 1988 */ 1989int services_convert_context(struct convert_context_args *args, 1990 struct context *oldc, struct context *newc, 1991 gfp_t gfp_flags) 1992{ 1993 struct ocontext *oc; 1994 struct role_datum *role; 1995 struct type_datum *typdatum; 1996 struct user_datum *usrdatum; 1997 char *s; 1998 u32 len; 1999 int rc; 2000 2001 if (oldc->str) { 2002 s = kstrdup(oldc->str, gfp_flags); 2003 if (!s) 2004 return -ENOMEM; 2005 2006 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL); 2007 if (rc == -EINVAL) { 2008 /* 2009 * Retain string representation for later mapping. 2010 * 2011 * IMPORTANT: We need to copy the contents of oldc->str 2012 * back into s again because string_to_context_struct() 2013 * may have garbled it. 2014 */ 2015 memcpy(s, oldc->str, oldc->len); 2016 context_init(newc); 2017 newc->str = s; 2018 newc->len = oldc->len; 2019 return 0; 2020 } 2021 kfree(s); 2022 if (rc) { 2023 /* Other error condition, e.g. ENOMEM. */ 2024 pr_err("SELinux: Unable to map context %s, rc = %d.\n", 2025 oldc->str, -rc); 2026 return rc; 2027 } 2028 pr_info("SELinux: Context %s became valid (mapped).\n", 2029 oldc->str); 2030 return 0; 2031 } 2032 2033 context_init(newc); 2034 2035 /* Convert the user. */ 2036 usrdatum = symtab_search(&args->newp->p_users, 2037 sym_name(args->oldp, SYM_USERS, oldc->user - 1)); 2038 if (!usrdatum) 2039 goto bad; 2040 newc->user = usrdatum->value; 2041 2042 /* Convert the role. */ 2043 role = symtab_search(&args->newp->p_roles, 2044 sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); 2045 if (!role) 2046 goto bad; 2047 newc->role = role->value; 2048 2049 /* Convert the type. */ 2050 typdatum = symtab_search(&args->newp->p_types, 2051 sym_name(args->oldp, SYM_TYPES, oldc->type - 1)); 2052 if (!typdatum) 2053 goto bad; 2054 newc->type = typdatum->value; 2055 2056 /* Convert the MLS fields if dealing with MLS policies */ 2057 if (args->oldp->mls_enabled && args->newp->mls_enabled) { 2058 rc = mls_convert_context(args->oldp, args->newp, oldc, newc); 2059 if (rc) 2060 goto bad; 2061 } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { 2062 /* 2063 * Switching between non-MLS and MLS policy: 2064 * ensure that the MLS fields of the context for all 2065 * existing entries in the sidtab are filled in with a 2066 * suitable default value, likely taken from one of the 2067 * initial SIDs. 2068 */ 2069 oc = args->newp->ocontexts[OCON_ISID]; 2070 while (oc && oc->sid[0] != SECINITSID_UNLABELED) 2071 oc = oc->next; 2072 if (!oc) { 2073 pr_err("SELinux: unable to look up" 2074 " the initial SIDs list\n"); 2075 goto bad; 2076 } 2077 rc = mls_range_set(newc, &oc->context[0].range); 2078 if (rc) 2079 goto bad; 2080 } 2081 2082 /* Check the validity of the new context. */ 2083 if (!policydb_context_isvalid(args->newp, newc)) { 2084 rc = convert_context_handle_invalid_context(args->oldp, oldc); 2085 if (rc) 2086 goto bad; 2087 } 2088 2089 return 0; 2090bad: 2091 /* Map old representation to string and save it. */ 2092 rc = context_struct_to_string(args->oldp, oldc, &s, &len); 2093 if (rc) 2094 return rc; 2095 context_destroy(newc); 2096 newc->str = s; 2097 newc->len = len; 2098 pr_info("SELinux: Context %s became invalid (unmapped).\n", 2099 newc->str); 2100 return 0; 2101} 2102 2103static void security_load_policycaps(struct selinux_policy *policy) 2104{ 2105 struct policydb *p; 2106 unsigned int i; 2107 struct ebitmap_node *node; 2108 2109 p = &policy->policydb; 2110 2111 for (i = 0; i < ARRAY_SIZE(selinux_state.policycap); i++) 2112 WRITE_ONCE(selinux_state.policycap[i], 2113 ebitmap_get_bit(&p->policycaps, i)); 2114 2115 for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) 2116 pr_info("SELinux: policy capability %s=%d\n", 2117 selinux_policycap_names[i], 2118 ebitmap_get_bit(&p->policycaps, i)); 2119 2120 ebitmap_for_each_positive_bit(&p->policycaps, node, i) { 2121 if (i >= ARRAY_SIZE(selinux_policycap_names)) 2122 pr_info("SELinux: unknown policy capability %u\n", 2123 i); 2124 } 2125} 2126 2127static int security_preserve_bools(struct selinux_policy *oldpolicy, 2128 struct selinux_policy *newpolicy); 2129 2130static void selinux_policy_free(struct selinux_policy *policy) 2131{ 2132 if (!policy) 2133 return; 2134 2135 sidtab_destroy(policy->sidtab); 2136 kfree(policy->map.mapping); 2137 policydb_destroy(&policy->policydb); 2138 kfree(policy->sidtab); 2139 kfree(policy); 2140} 2141 2142static void selinux_policy_cond_free(struct selinux_policy *policy) 2143{ 2144 cond_policydb_destroy_dup(&policy->policydb); 2145 kfree(policy); 2146} 2147 2148void selinux_policy_cancel(struct selinux_load_state *load_state) 2149{ 2150 struct selinux_state *state = &selinux_state; 2151 struct selinux_policy *oldpolicy; 2152 2153 oldpolicy = rcu_dereference_protected(state->policy, 2154 lockdep_is_held(&state->policy_mutex)); 2155 2156 sidtab_cancel_convert(oldpolicy->sidtab); 2157 selinux_policy_free(load_state->policy); 2158 kfree(load_state->convert_data); 2159} 2160 2161static void selinux_notify_policy_change(u32 seqno) 2162{ 2163 /* Flush external caches and notify userspace of policy load */ 2164 avc_ss_reset(seqno); 2165 selnl_notify_policyload(seqno); 2166 selinux_status_update_policyload(seqno); 2167 selinux_netlbl_cache_invalidate(); 2168 selinux_xfrm_notify_policyload(); 2169 selinux_ima_measure_state_locked(); 2170} 2171 2172void selinux_policy_commit(struct selinux_load_state *load_state) 2173{ 2174 struct selinux_state *state = &selinux_state; 2175 struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; 2176 unsigned long flags; 2177 u32 seqno; 2178 2179 oldpolicy = rcu_dereference_protected(state->policy, 2180 lockdep_is_held(&state->policy_mutex)); 2181 2182 /* If switching between different policy types, log MLS status */ 2183 if (oldpolicy) { 2184 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) 2185 pr_info("SELinux: Disabling MLS support...\n"); 2186 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) 2187 pr_info("SELinux: Enabling MLS support...\n"); 2188 } 2189 2190 /* Set latest granting seqno for new policy. */ 2191 if (oldpolicy) 2192 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 2193 else 2194 newpolicy->latest_granting = 1; 2195 seqno = newpolicy->latest_granting; 2196 2197 /* Install the new policy. */ 2198 if (oldpolicy) { 2199 sidtab_freeze_begin(oldpolicy->sidtab, &flags); 2200 rcu_assign_pointer(state->policy, newpolicy); 2201 sidtab_freeze_end(oldpolicy->sidtab, &flags); 2202 } else { 2203 rcu_assign_pointer(state->policy, newpolicy); 2204 } 2205 2206 /* Load the policycaps from the new policy */ 2207 security_load_policycaps(newpolicy); 2208 2209 if (!selinux_initialized()) { 2210 /* 2211 * After first policy load, the security server is 2212 * marked as initialized and ready to handle requests and 2213 * any objects created prior to policy load are then labeled. 2214 */ 2215 selinux_mark_initialized(); 2216 selinux_complete_init(); 2217 } 2218 2219 /* Free the old policy */ 2220 synchronize_rcu(); 2221 selinux_policy_free(oldpolicy); 2222 kfree(load_state->convert_data); 2223 2224 /* Notify others of the policy change */ 2225 selinux_notify_policy_change(seqno); 2226} 2227 2228/** 2229 * security_load_policy - Load a security policy configuration. 2230 * @data: binary policy data 2231 * @len: length of data in bytes 2232 * @load_state: policy load state 2233 * 2234 * Load a new set of security policy configuration data, 2235 * validate it and convert the SID table as necessary. 2236 * This function will flush the access vector cache after 2237 * loading the new policy. 2238 */ 2239int security_load_policy(void *data, size_t len, 2240 struct selinux_load_state *load_state) 2241{ 2242 struct selinux_state *state = &selinux_state; 2243 struct selinux_policy *newpolicy, *oldpolicy; 2244 struct selinux_policy_convert_data *convert_data; 2245 int rc = 0; 2246 struct policy_file file = { data, len }, *fp = &file; 2247 2248 newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); 2249 if (!newpolicy) 2250 return -ENOMEM; 2251 2252 newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); 2253 if (!newpolicy->sidtab) { 2254 rc = -ENOMEM; 2255 goto err_policy; 2256 } 2257 2258 rc = policydb_read(&newpolicy->policydb, fp); 2259 if (rc) 2260 goto err_sidtab; 2261 2262 newpolicy->policydb.len = len; 2263 rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, 2264 &newpolicy->map); 2265 if (rc) 2266 goto err_policydb; 2267 2268 rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); 2269 if (rc) { 2270 pr_err("SELinux: unable to load the initial SIDs\n"); 2271 goto err_mapping; 2272 } 2273 2274 if (!selinux_initialized()) { 2275 /* First policy load, so no need to preserve state from old policy */ 2276 load_state->policy = newpolicy; 2277 load_state->convert_data = NULL; 2278 return 0; 2279 } 2280 2281 oldpolicy = rcu_dereference_protected(state->policy, 2282 lockdep_is_held(&state->policy_mutex)); 2283 2284 /* Preserve active boolean values from the old policy */ 2285 rc = security_preserve_bools(oldpolicy, newpolicy); 2286 if (rc) { 2287 pr_err("SELinux: unable to preserve booleans\n"); 2288 goto err_free_isids; 2289 } 2290 2291 /* 2292 * Convert the internal representations of contexts 2293 * in the new SID table. 2294 */ 2295 2296 convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); 2297 if (!convert_data) { 2298 rc = -ENOMEM; 2299 goto err_free_isids; 2300 } 2301 2302 convert_data->args.oldp = &oldpolicy->policydb; 2303 convert_data->args.newp = &newpolicy->policydb; 2304 2305 convert_data->sidtab_params.args = &convert_data->args; 2306 convert_data->sidtab_params.target = newpolicy->sidtab; 2307 2308 rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); 2309 if (rc) { 2310 pr_err("SELinux: unable to convert the internal" 2311 " representation of contexts in the new SID" 2312 " table\n"); 2313 goto err_free_convert_data; 2314 } 2315 2316 load_state->policy = newpolicy; 2317 load_state->convert_data = convert_data; 2318 return 0; 2319 2320err_free_convert_data: 2321 kfree(convert_data); 2322err_free_isids: 2323 sidtab_destroy(newpolicy->sidtab); 2324err_mapping: 2325 kfree(newpolicy->map.mapping); 2326err_policydb: 2327 policydb_destroy(&newpolicy->policydb); 2328err_sidtab: 2329 kfree(newpolicy->sidtab); 2330err_policy: 2331 kfree(newpolicy); 2332 2333 return rc; 2334} 2335 2336/** 2337 * ocontext_to_sid - Helper to safely get sid for an ocontext 2338 * @sidtab: SID table 2339 * @c: ocontext structure 2340 * @index: index of the context entry (0 or 1) 2341 * @out_sid: pointer to the resulting SID value 2342 * 2343 * For all ocontexts except OCON_ISID the SID fields are populated 2344 * on-demand when needed. Since updating the SID value is an SMP-sensitive 2345 * operation, this helper must be used to do that safely. 2346 * 2347 * WARNING: This function may return -ESTALE, indicating that the caller 2348 * must retry the operation after re-acquiring the policy pointer! 2349 */ 2350static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, 2351 size_t index, u32 *out_sid) 2352{ 2353 int rc; 2354 u32 sid; 2355 2356 /* Ensure the associated sidtab entry is visible to this thread. */ 2357 sid = smp_load_acquire(&c->sid[index]); 2358 if (!sid) { 2359 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); 2360 if (rc) 2361 return rc; 2362 2363 /* 2364 * Ensure the new sidtab entry is visible to other threads 2365 * when they see the SID. 2366 */ 2367 smp_store_release(&c->sid[index], sid); 2368 } 2369 *out_sid = sid; 2370 return 0; 2371} 2372 2373/** 2374 * security_port_sid - Obtain the SID for a port. 2375 * @protocol: protocol number 2376 * @port: port number 2377 * @out_sid: security identifier 2378 */ 2379int security_port_sid(u8 protocol, u16 port, u32 *out_sid) 2380{ 2381 struct selinux_policy *policy; 2382 struct policydb *policydb; 2383 struct sidtab *sidtab; 2384 struct ocontext *c; 2385 int rc; 2386 2387 if (!selinux_initialized()) { 2388 *out_sid = SECINITSID_PORT; 2389 return 0; 2390 } 2391 2392retry: 2393 rc = 0; 2394 rcu_read_lock(); 2395 policy = rcu_dereference(selinux_state.policy); 2396 policydb = &policy->policydb; 2397 sidtab = policy->sidtab; 2398 2399 c = policydb->ocontexts[OCON_PORT]; 2400 while (c) { 2401 if (c->u.port.protocol == protocol && 2402 c->u.port.low_port <= port && 2403 c->u.port.high_port >= port) 2404 break; 2405 c = c->next; 2406 } 2407 2408 if (c) { 2409 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2410 if (rc == -ESTALE) { 2411 rcu_read_unlock(); 2412 goto retry; 2413 } 2414 if (rc) 2415 goto out; 2416 } else { 2417 *out_sid = SECINITSID_PORT; 2418 } 2419 2420out: 2421 rcu_read_unlock(); 2422 return rc; 2423} 2424 2425/** 2426 * security_ib_pkey_sid - Obtain the SID for a pkey. 2427 * @subnet_prefix: Subnet Prefix 2428 * @pkey_num: pkey number 2429 * @out_sid: security identifier 2430 */ 2431int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid) 2432{ 2433 struct selinux_policy *policy; 2434 struct policydb *policydb; 2435 struct sidtab *sidtab; 2436 struct ocontext *c; 2437 int rc; 2438 2439 if (!selinux_initialized()) { 2440 *out_sid = SECINITSID_UNLABELED; 2441 return 0; 2442 } 2443 2444retry: 2445 rc = 0; 2446 rcu_read_lock(); 2447 policy = rcu_dereference(selinux_state.policy); 2448 policydb = &policy->policydb; 2449 sidtab = policy->sidtab; 2450 2451 c = policydb->ocontexts[OCON_IBPKEY]; 2452 while (c) { 2453 if (c->u.ibpkey.low_pkey <= pkey_num && 2454 c->u.ibpkey.high_pkey >= pkey_num && 2455 c->u.ibpkey.subnet_prefix == subnet_prefix) 2456 break; 2457 2458 c = c->next; 2459 } 2460 2461 if (c) { 2462 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2463 if (rc == -ESTALE) { 2464 rcu_read_unlock(); 2465 goto retry; 2466 } 2467 if (rc) 2468 goto out; 2469 } else 2470 *out_sid = SECINITSID_UNLABELED; 2471 2472out: 2473 rcu_read_unlock(); 2474 return rc; 2475} 2476 2477/** 2478 * security_ib_endport_sid - Obtain the SID for a subnet management interface. 2479 * @dev_name: device name 2480 * @port_num: port number 2481 * @out_sid: security identifier 2482 */ 2483int security_ib_endport_sid(const char *dev_name, u8 port_num, u32 *out_sid) 2484{ 2485 struct selinux_policy *policy; 2486 struct policydb *policydb; 2487 struct sidtab *sidtab; 2488 struct ocontext *c; 2489 int rc; 2490 2491 if (!selinux_initialized()) { 2492 *out_sid = SECINITSID_UNLABELED; 2493 return 0; 2494 } 2495 2496retry: 2497 rc = 0; 2498 rcu_read_lock(); 2499 policy = rcu_dereference(selinux_state.policy); 2500 policydb = &policy->policydb; 2501 sidtab = policy->sidtab; 2502 2503 c = policydb->ocontexts[OCON_IBENDPORT]; 2504 while (c) { 2505 if (c->u.ibendport.port == port_num && 2506 !strncmp(c->u.ibendport.dev_name, 2507 dev_name, 2508 IB_DEVICE_NAME_MAX)) 2509 break; 2510 2511 c = c->next; 2512 } 2513 2514 if (c) { 2515 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2516 if (rc == -ESTALE) { 2517 rcu_read_unlock(); 2518 goto retry; 2519 } 2520 if (rc) 2521 goto out; 2522 } else 2523 *out_sid = SECINITSID_UNLABELED; 2524 2525out: 2526 rcu_read_unlock(); 2527 return rc; 2528} 2529 2530/** 2531 * security_netif_sid - Obtain the SID for a network interface. 2532 * @name: interface name 2533 * @if_sid: interface SID 2534 */ 2535int security_netif_sid(char *name, u32 *if_sid) 2536{ 2537 struct selinux_policy *policy; 2538 struct policydb *policydb; 2539 struct sidtab *sidtab; 2540 int rc; 2541 struct ocontext *c; 2542 2543 if (!selinux_initialized()) { 2544 *if_sid = SECINITSID_NETIF; 2545 return 0; 2546 } 2547 2548retry: 2549 rc = 0; 2550 rcu_read_lock(); 2551 policy = rcu_dereference(selinux_state.policy); 2552 policydb = &policy->policydb; 2553 sidtab = policy->sidtab; 2554 2555 c = policydb->ocontexts[OCON_NETIF]; 2556 while (c) { 2557 if (strcmp(name, c->u.name) == 0) 2558 break; 2559 c = c->next; 2560 } 2561 2562 if (c) { 2563 rc = ocontext_to_sid(sidtab, c, 0, if_sid); 2564 if (rc == -ESTALE) { 2565 rcu_read_unlock(); 2566 goto retry; 2567 } 2568 if (rc) 2569 goto out; 2570 } else 2571 *if_sid = SECINITSID_NETIF; 2572 2573out: 2574 rcu_read_unlock(); 2575 return rc; 2576} 2577 2578static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 2579{ 2580 int i, fail = 0; 2581 2582 for (i = 0; i < 4; i++) 2583 if (addr[i] != (input[i] & mask[i])) { 2584 fail = 1; 2585 break; 2586 } 2587 2588 return !fail; 2589} 2590 2591/** 2592 * security_node_sid - Obtain the SID for a node (host). 2593 * @domain: communication domain aka address family 2594 * @addrp: address 2595 * @addrlen: address length in bytes 2596 * @out_sid: security identifier 2597 */ 2598int security_node_sid(u16 domain, 2599 void *addrp, 2600 u32 addrlen, 2601 u32 *out_sid) 2602{ 2603 struct selinux_policy *policy; 2604 struct policydb *policydb; 2605 struct sidtab *sidtab; 2606 int rc; 2607 struct ocontext *c; 2608 2609 if (!selinux_initialized()) { 2610 *out_sid = SECINITSID_NODE; 2611 return 0; 2612 } 2613 2614retry: 2615 rcu_read_lock(); 2616 policy = rcu_dereference(selinux_state.policy); 2617 policydb = &policy->policydb; 2618 sidtab = policy->sidtab; 2619 2620 switch (domain) { 2621 case AF_INET: { 2622 u32 addr; 2623 2624 rc = -EINVAL; 2625 if (addrlen != sizeof(u32)) 2626 goto out; 2627 2628 addr = *((u32 *)addrp); 2629 2630 c = policydb->ocontexts[OCON_NODE]; 2631 while (c) { 2632 if (c->u.node.addr == (addr & c->u.node.mask)) 2633 break; 2634 c = c->next; 2635 } 2636 break; 2637 } 2638 2639 case AF_INET6: 2640 rc = -EINVAL; 2641 if (addrlen != sizeof(u64) * 2) 2642 goto out; 2643 c = policydb->ocontexts[OCON_NODE6]; 2644 while (c) { 2645 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 2646 c->u.node6.mask)) 2647 break; 2648 c = c->next; 2649 } 2650 break; 2651 2652 default: 2653 rc = 0; 2654 *out_sid = SECINITSID_NODE; 2655 goto out; 2656 } 2657 2658 if (c) { 2659 rc = ocontext_to_sid(sidtab, c, 0, out_sid); 2660 if (rc == -ESTALE) { 2661 rcu_read_unlock(); 2662 goto retry; 2663 } 2664 if (rc) 2665 goto out; 2666 } else { 2667 *out_sid = SECINITSID_NODE; 2668 } 2669 2670 rc = 0; 2671out: 2672 rcu_read_unlock(); 2673 return rc; 2674} 2675 2676#define SIDS_NEL 25 2677 2678/** 2679 * security_get_user_sids - Obtain reachable SIDs for a user. 2680 * @fromsid: starting SID 2681 * @username: username 2682 * @sids: array of reachable SIDs for user 2683 * @nel: number of elements in @sids 2684 * 2685 * Generate the set of SIDs for legal security contexts 2686 * for a given user that can be reached by @fromsid. 2687 * Set *@sids to point to a dynamically allocated 2688 * array containing the set of SIDs. Set *@nel to the 2689 * number of elements in the array. 2690 */ 2691 2692int security_get_user_sids(u32 fromsid, 2693 char *username, 2694 u32 **sids, 2695 u32 *nel) 2696{ 2697 struct selinux_policy *policy; 2698 struct policydb *policydb; 2699 struct sidtab *sidtab; 2700 struct context *fromcon, usercon; 2701 u32 *mysids = NULL, *mysids2, sid; 2702 u32 i, j, mynel, maxnel = SIDS_NEL; 2703 struct user_datum *user; 2704 struct role_datum *role; 2705 struct ebitmap_node *rnode, *tnode; 2706 int rc; 2707 2708 *sids = NULL; 2709 *nel = 0; 2710 2711 if (!selinux_initialized()) 2712 return 0; 2713 2714 mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); 2715 if (!mysids) 2716 return -ENOMEM; 2717 2718retry: 2719 mynel = 0; 2720 rcu_read_lock(); 2721 policy = rcu_dereference(selinux_state.policy); 2722 policydb = &policy->policydb; 2723 sidtab = policy->sidtab; 2724 2725 context_init(&usercon); 2726 2727 rc = -EINVAL; 2728 fromcon = sidtab_search(sidtab, fromsid); 2729 if (!fromcon) 2730 goto out_unlock; 2731 2732 rc = -EINVAL; 2733 user = symtab_search(&policydb->p_users, username); 2734 if (!user) 2735 goto out_unlock; 2736 2737 usercon.user = user->value; 2738 2739 ebitmap_for_each_positive_bit(&user->roles, rnode, i) { 2740 role = policydb->role_val_to_struct[i]; 2741 usercon.role = i + 1; 2742 ebitmap_for_each_positive_bit(&role->types, tnode, j) { 2743 usercon.type = j + 1; 2744 2745 if (mls_setup_user_range(policydb, fromcon, user, 2746 &usercon)) 2747 continue; 2748 2749 rc = sidtab_context_to_sid(sidtab, &usercon, &sid); 2750 if (rc == -ESTALE) { 2751 rcu_read_unlock(); 2752 goto retry; 2753 } 2754 if (rc) 2755 goto out_unlock; 2756 if (mynel < maxnel) { 2757 mysids[mynel++] = sid; 2758 } else { 2759 rc = -ENOMEM; 2760 maxnel += SIDS_NEL; 2761 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); 2762 if (!mysids2) 2763 goto out_unlock; 2764 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 2765 kfree(mysids); 2766 mysids = mysids2; 2767 mysids[mynel++] = sid; 2768 } 2769 } 2770 } 2771 rc = 0; 2772out_unlock: 2773 rcu_read_unlock(); 2774 if (rc || !mynel) { 2775 kfree(mysids); 2776 return rc; 2777 } 2778 2779 rc = -ENOMEM; 2780 mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); 2781 if (!mysids2) { 2782 kfree(mysids); 2783 return rc; 2784 } 2785 for (i = 0, j = 0; i < mynel; i++) { 2786 struct av_decision dummy_avd; 2787 rc = avc_has_perm_noaudit(fromsid, mysids[i], 2788 SECCLASS_PROCESS, /* kernel value */ 2789 PROCESS__TRANSITION, AVC_STRICT, 2790 &dummy_avd); 2791 if (!rc) 2792 mysids2[j++] = mysids[i]; 2793 cond_resched(); 2794 } 2795 kfree(mysids); 2796 *sids = mysids2; 2797 *nel = j; 2798 return 0; 2799} 2800 2801/** 2802 * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem 2803 * @policy: policy 2804 * @fstype: filesystem type 2805 * @path: path from root of mount 2806 * @orig_sclass: file security class 2807 * @sid: SID for path 2808 * 2809 * Obtain a SID to use for a file in a filesystem that 2810 * cannot support xattr or use a fixed labeling behavior like 2811 * transition SIDs or task SIDs. 2812 * 2813 * WARNING: This function may return -ESTALE, indicating that the caller 2814 * must retry the operation after re-acquiring the policy pointer! 2815 */ 2816static inline int __security_genfs_sid(struct selinux_policy *policy, 2817 const char *fstype, 2818 const char *path, 2819 u16 orig_sclass, 2820 u32 *sid) 2821{ 2822 struct policydb *policydb = &policy->policydb; 2823 struct sidtab *sidtab = policy->sidtab; 2824 u16 sclass; 2825 struct genfs *genfs; 2826 struct ocontext *c; 2827 int cmp = 0; 2828 2829 while (path[0] == '/' && path[1] == '/') 2830 path++; 2831 2832 sclass = unmap_class(&policy->map, orig_sclass); 2833 *sid = SECINITSID_UNLABELED; 2834 2835 for (genfs = policydb->genfs; genfs; genfs = genfs->next) { 2836 cmp = strcmp(fstype, genfs->fstype); 2837 if (cmp <= 0) 2838 break; 2839 } 2840 2841 if (!genfs || cmp) 2842 return -ENOENT; 2843 2844 for (c = genfs->head; c; c = c->next) { 2845 size_t len = strlen(c->u.name); 2846 if ((!c->v.sclass || sclass == c->v.sclass) && 2847 (strncmp(c->u.name, path, len) == 0)) 2848 break; 2849 } 2850 2851 if (!c) 2852 return -ENOENT; 2853 2854 return ocontext_to_sid(sidtab, c, 0, sid); 2855} 2856 2857/** 2858 * security_genfs_sid - Obtain a SID for a file in a filesystem 2859 * @fstype: filesystem type 2860 * @path: path from root of mount 2861 * @orig_sclass: file security class 2862 * @sid: SID for path 2863 * 2864 * Acquire policy_rwlock before calling __security_genfs_sid() and release 2865 * it afterward. 2866 */ 2867int security_genfs_sid(const char *fstype, 2868 const char *path, 2869 u16 orig_sclass, 2870 u32 *sid) 2871{ 2872 struct selinux_policy *policy; 2873 int retval; 2874 2875 if (!selinux_initialized()) { 2876 *sid = SECINITSID_UNLABELED; 2877 return 0; 2878 } 2879 2880 do { 2881 rcu_read_lock(); 2882 policy = rcu_dereference(selinux_state.policy); 2883 retval = __security_genfs_sid(policy, fstype, path, 2884 orig_sclass, sid); 2885 rcu_read_unlock(); 2886 } while (retval == -ESTALE); 2887 return retval; 2888} 2889 2890int selinux_policy_genfs_sid(struct selinux_policy *policy, 2891 const char *fstype, 2892 const char *path, 2893 u16 orig_sclass, 2894 u32 *sid) 2895{ 2896 /* no lock required, policy is not yet accessible by other threads */ 2897 return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); 2898} 2899 2900/** 2901 * security_fs_use - Determine how to handle labeling for a filesystem. 2902 * @sb: superblock in question 2903 */ 2904int security_fs_use(struct super_block *sb) 2905{ 2906 struct selinux_policy *policy; 2907 struct policydb *policydb; 2908 struct sidtab *sidtab; 2909 int rc; 2910 struct ocontext *c; 2911 struct superblock_security_struct *sbsec = selinux_superblock(sb); 2912 const char *fstype = sb->s_type->name; 2913 2914 if (!selinux_initialized()) { 2915 sbsec->behavior = SECURITY_FS_USE_NONE; 2916 sbsec->sid = SECINITSID_UNLABELED; 2917 return 0; 2918 } 2919 2920retry: 2921 rcu_read_lock(); 2922 policy = rcu_dereference(selinux_state.policy); 2923 policydb = &policy->policydb; 2924 sidtab = policy->sidtab; 2925 2926 c = policydb->ocontexts[OCON_FSUSE]; 2927 while (c) { 2928 if (strcmp(fstype, c->u.name) == 0) 2929 break; 2930 c = c->next; 2931 } 2932 2933 if (c) { 2934 sbsec->behavior = c->v.behavior; 2935 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); 2936 if (rc == -ESTALE) { 2937 rcu_read_unlock(); 2938 goto retry; 2939 } 2940 if (rc) 2941 goto out; 2942 } else { 2943 rc = __security_genfs_sid(policy, fstype, "/", 2944 SECCLASS_DIR, &sbsec->sid); 2945 if (rc == -ESTALE) { 2946 rcu_read_unlock(); 2947 goto retry; 2948 } 2949 if (rc) { 2950 sbsec->behavior = SECURITY_FS_USE_NONE; 2951 rc = 0; 2952 } else { 2953 sbsec->behavior = SECURITY_FS_USE_GENFS; 2954 } 2955 } 2956 2957out: 2958 rcu_read_unlock(); 2959 return rc; 2960} 2961 2962int security_get_bools(struct selinux_policy *policy, 2963 u32 *len, char ***names, int **values) 2964{ 2965 struct policydb *policydb; 2966 u32 i; 2967 int rc; 2968 2969 policydb = &policy->policydb; 2970 2971 *names = NULL; 2972 *values = NULL; 2973 2974 rc = 0; 2975 *len = policydb->p_bools.nprim; 2976 if (!*len) 2977 goto out; 2978 2979 rc = -ENOMEM; 2980 *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); 2981 if (!*names) 2982 goto err; 2983 2984 rc = -ENOMEM; 2985 *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); 2986 if (!*values) 2987 goto err; 2988 2989 for (i = 0; i < *len; i++) { 2990 (*values)[i] = policydb->bool_val_to_struct[i]->state; 2991 2992 rc = -ENOMEM; 2993 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), 2994 GFP_ATOMIC); 2995 if (!(*names)[i]) 2996 goto err; 2997 } 2998 rc = 0; 2999out: 3000 return rc; 3001err: 3002 if (*names) { 3003 for (i = 0; i < *len; i++) 3004 kfree((*names)[i]); 3005 kfree(*names); 3006 } 3007 kfree(*values); 3008 *len = 0; 3009 *names = NULL; 3010 *values = NULL; 3011 goto out; 3012} 3013 3014 3015int security_set_bools(u32 len, int *values) 3016{ 3017 struct selinux_state *state = &selinux_state; 3018 struct selinux_policy *newpolicy, *oldpolicy; 3019 int rc; 3020 u32 i, seqno = 0; 3021 3022 if (!selinux_initialized()) 3023 return -EINVAL; 3024 3025 oldpolicy = rcu_dereference_protected(state->policy, 3026 lockdep_is_held(&state->policy_mutex)); 3027 3028 /* Consistency check on number of booleans, should never fail */ 3029 if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) 3030 return -EINVAL; 3031 3032 newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); 3033 if (!newpolicy) 3034 return -ENOMEM; 3035 3036 /* 3037 * Deep copy only the parts of the policydb that might be 3038 * modified as a result of changing booleans. 3039 */ 3040 rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); 3041 if (rc) { 3042 kfree(newpolicy); 3043 return -ENOMEM; 3044 } 3045 3046 /* Update the boolean states in the copy */ 3047 for (i = 0; i < len; i++) { 3048 int new_state = !!values[i]; 3049 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; 3050 3051 if (new_state != old_state) { 3052 audit_log(audit_context(), GFP_ATOMIC, 3053 AUDIT_MAC_CONFIG_CHANGE, 3054 "bool=%s val=%d old_val=%d auid=%u ses=%u", 3055 sym_name(&newpolicy->policydb, SYM_BOOLS, i), 3056 new_state, 3057 old_state, 3058 from_kuid(&init_user_ns, audit_get_loginuid(current)), 3059 audit_get_sessionid(current)); 3060 newpolicy->policydb.bool_val_to_struct[i]->state = new_state; 3061 } 3062 } 3063 3064 /* Re-evaluate the conditional rules in the copy */ 3065 evaluate_cond_nodes(&newpolicy->policydb); 3066 3067 /* Set latest granting seqno for new policy */ 3068 newpolicy->latest_granting = oldpolicy->latest_granting + 1; 3069 seqno = newpolicy->latest_granting; 3070 3071 /* Install the new policy */ 3072 rcu_assign_pointer(state->policy, newpolicy); 3073 3074 /* 3075 * Free the conditional portions of the old policydb 3076 * that were copied for the new policy, and the oldpolicy 3077 * structure itself but not what it references. 3078 */ 3079 synchronize_rcu(); 3080 selinux_policy_cond_free(oldpolicy); 3081 3082 /* Notify others of the policy change */ 3083 selinux_notify_policy_change(seqno); 3084 return 0; 3085} 3086 3087int security_get_bool_value(u32 index) 3088{ 3089 struct selinux_policy *policy; 3090 struct policydb *policydb; 3091 int rc; 3092 u32 len; 3093 3094 if (!selinux_initialized()) 3095 return 0; 3096 3097 rcu_read_lock(); 3098 policy = rcu_dereference(selinux_state.policy); 3099 policydb = &policy->policydb; 3100 3101 rc = -EFAULT; 3102 len = policydb->p_bools.nprim; 3103 if (index >= len) 3104 goto out; 3105 3106 rc = policydb->bool_val_to_struct[index]->state; 3107out: 3108 rcu_read_unlock(); 3109 return rc; 3110} 3111 3112static int security_preserve_bools(struct selinux_policy *oldpolicy, 3113 struct selinux_policy *newpolicy) 3114{ 3115 int rc, *bvalues = NULL; 3116 char **bnames = NULL; 3117 struct cond_bool_datum *booldatum; 3118 u32 i, nbools = 0; 3119 3120 rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); 3121 if (rc) 3122 goto out; 3123 for (i = 0; i < nbools; i++) { 3124 booldatum = symtab_search(&newpolicy->policydb.p_bools, 3125 bnames[i]); 3126 if (booldatum) 3127 booldatum->state = bvalues[i]; 3128 } 3129 evaluate_cond_nodes(&newpolicy->policydb); 3130 3131out: 3132 if (bnames) { 3133 for (i = 0; i < nbools; i++) 3134 kfree(bnames[i]); 3135 } 3136 kfree(bnames); 3137 kfree(bvalues); 3138 return rc; 3139} 3140 3141/* 3142 * security_sid_mls_copy() - computes a new sid based on the given 3143 * sid and the mls portion of mls_sid. 3144 */ 3145int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) 3146{ 3147 struct selinux_policy *policy; 3148 struct policydb *policydb; 3149 struct sidtab *sidtab; 3150 struct context *context1; 3151 struct context *context2; 3152 struct context newcon; 3153 char *s; 3154 u32 len; 3155 int rc; 3156 3157 if (!selinux_initialized()) { 3158 *new_sid = sid; 3159 return 0; 3160 } 3161 3162retry: 3163 rc = 0; 3164 context_init(&newcon); 3165 3166 rcu_read_lock(); 3167 policy = rcu_dereference(selinux_state.policy); 3168 policydb = &policy->policydb; 3169 sidtab = policy->sidtab; 3170 3171 if (!policydb->mls_enabled) { 3172 *new_sid = sid; 3173 goto out_unlock; 3174 } 3175 3176 rc = -EINVAL; 3177 context1 = sidtab_search(sidtab, sid); 3178 if (!context1) { 3179 pr_err("SELinux: %s: unrecognized SID %d\n", 3180 __func__, sid); 3181 goto out_unlock; 3182 } 3183 3184 rc = -EINVAL; 3185 context2 = sidtab_search(sidtab, mls_sid); 3186 if (!context2) { 3187 pr_err("SELinux: %s: unrecognized SID %d\n", 3188 __func__, mls_sid); 3189 goto out_unlock; 3190 } 3191 3192 newcon.user = context1->user; 3193 newcon.role = context1->role; 3194 newcon.type = context1->type; 3195 rc = mls_context_cpy(&newcon, context2); 3196 if (rc) 3197 goto out_unlock; 3198 3199 /* Check the validity of the new context. */ 3200 if (!policydb_context_isvalid(policydb, &newcon)) { 3201 rc = convert_context_handle_invalid_context(policydb, 3202 &newcon); 3203 if (rc) { 3204 if (!context_struct_to_string(policydb, &newcon, &s, 3205 &len)) { 3206 struct audit_buffer *ab; 3207 3208 ab = audit_log_start(audit_context(), 3209 GFP_ATOMIC, 3210 AUDIT_SELINUX_ERR); 3211 audit_log_format(ab, 3212 "op=security_sid_mls_copy invalid_context="); 3213 /* don't record NUL with untrusted strings */ 3214 audit_log_n_untrustedstring(ab, s, len - 1); 3215 audit_log_end(ab); 3216 kfree(s); 3217 } 3218 goto out_unlock; 3219 } 3220 } 3221 rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); 3222 if (rc == -ESTALE) { 3223 rcu_read_unlock(); 3224 context_destroy(&newcon); 3225 goto retry; 3226 } 3227out_unlock: 3228 rcu_read_unlock(); 3229 context_destroy(&newcon); 3230 return rc; 3231} 3232 3233/** 3234 * security_net_peersid_resolve - Compare and resolve two network peer SIDs 3235 * @nlbl_sid: NetLabel SID 3236 * @nlbl_type: NetLabel labeling protocol type 3237 * @xfrm_sid: XFRM SID 3238 * @peer_sid: network peer sid 3239 * 3240 * Description: 3241 * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be 3242 * resolved into a single SID it is returned via @peer_sid and the function 3243 * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function 3244 * returns a negative value. A table summarizing the behavior is below: 3245 * 3246 * | function return | @sid 3247 * ------------------------------+-----------------+----------------- 3248 * no peer labels | 0 | SECSID_NULL 3249 * single peer label | 0 | <peer_label> 3250 * multiple, consistent labels | 0 | <peer_label> 3251 * multiple, inconsistent labels | -<errno> | SECSID_NULL 3252 * 3253 */ 3254int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, 3255 u32 xfrm_sid, 3256 u32 *peer_sid) 3257{ 3258 struct selinux_policy *policy; 3259 struct policydb *policydb; 3260 struct sidtab *sidtab; 3261 int rc; 3262 struct context *nlbl_ctx; 3263 struct context *xfrm_ctx; 3264 3265 *peer_sid = SECSID_NULL; 3266 3267 /* handle the common (which also happens to be the set of easy) cases 3268 * right away, these two if statements catch everything involving a 3269 * single or absent peer SID/label */ 3270 if (xfrm_sid == SECSID_NULL) { 3271 *peer_sid = nlbl_sid; 3272 return 0; 3273 } 3274 /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label 3275 * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label 3276 * is present */ 3277 if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { 3278 *peer_sid = xfrm_sid; 3279 return 0; 3280 } 3281 3282 if (!selinux_initialized()) 3283 return 0; 3284 3285 rcu_read_lock(); 3286 policy = rcu_dereference(selinux_state.policy); 3287 policydb = &policy->policydb; 3288 sidtab = policy->sidtab; 3289 3290 /* 3291 * We don't need to check initialized here since the only way both 3292 * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the 3293 * security server was initialized and state->initialized was true. 3294 */ 3295 if (!policydb->mls_enabled) { 3296 rc = 0; 3297 goto out; 3298 } 3299 3300 rc = -EINVAL; 3301 nlbl_ctx = sidtab_search(sidtab, nlbl_sid); 3302 if (!nlbl_ctx) { 3303 pr_err("SELinux: %s: unrecognized SID %d\n", 3304 __func__, nlbl_sid); 3305 goto out; 3306 } 3307 rc = -EINVAL; 3308 xfrm_ctx = sidtab_search(sidtab, xfrm_sid); 3309 if (!xfrm_ctx) { 3310 pr_err("SELinux: %s: unrecognized SID %d\n", 3311 __func__, xfrm_sid); 3312 goto out; 3313 } 3314 rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); 3315 if (rc) 3316 goto out; 3317 3318 /* at present NetLabel SIDs/labels really only carry MLS 3319 * information so if the MLS portion of the NetLabel SID 3320 * matches the MLS portion of the labeled XFRM SID/label 3321 * then pass along the XFRM SID as it is the most 3322 * expressive */ 3323 *peer_sid = xfrm_sid; 3324out: 3325 rcu_read_unlock(); 3326 return rc; 3327} 3328 3329static int get_classes_callback(void *k, void *d, void *args) 3330{ 3331 struct class_datum *datum = d; 3332 char *name = k, **classes = args; 3333 u32 value = datum->value - 1; 3334 3335 classes[value] = kstrdup(name, GFP_ATOMIC); 3336 if (!classes[value]) 3337 return -ENOMEM; 3338 3339 return 0; 3340} 3341 3342int security_get_classes(struct selinux_policy *policy, 3343 char ***classes, u32 *nclasses) 3344{ 3345 struct policydb *policydb; 3346 int rc; 3347 3348 policydb = &policy->policydb; 3349 3350 rc = -ENOMEM; 3351 *nclasses = policydb->p_classes.nprim; 3352 *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); 3353 if (!*classes) 3354 goto out; 3355 3356 rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, 3357 *classes); 3358 if (rc) { 3359 u32 i; 3360 3361 for (i = 0; i < *nclasses; i++) 3362 kfree((*classes)[i]); 3363 kfree(*classes); 3364 } 3365 3366out: 3367 return rc; 3368} 3369 3370static int get_permissions_callback(void *k, void *d, void *args) 3371{ 3372 struct perm_datum *datum = d; 3373 char *name = k, **perms = args; 3374 u32 value = datum->value - 1; 3375 3376 perms[value] = kstrdup(name, GFP_ATOMIC); 3377 if (!perms[value]) 3378 return -ENOMEM; 3379 3380 return 0; 3381} 3382 3383int security_get_permissions(struct selinux_policy *policy, 3384 const char *class, char ***perms, u32 *nperms) 3385{ 3386 struct policydb *policydb; 3387 u32 i; 3388 int rc; 3389 struct class_datum *match; 3390 3391 policydb = &policy->policydb; 3392 3393 rc = -EINVAL; 3394 match = symtab_search(&policydb->p_classes, class); 3395 if (!match) { 3396 pr_err("SELinux: %s: unrecognized class %s\n", 3397 __func__, class); 3398 goto out; 3399 } 3400 3401 rc = -ENOMEM; 3402 *nperms = match->permissions.nprim; 3403 *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); 3404 if (!*perms) 3405 goto out; 3406 3407 if (match->comdatum) { 3408 rc = hashtab_map(&match->comdatum->permissions.table, 3409 get_permissions_callback, *perms); 3410 if (rc) 3411 goto err; 3412 } 3413 3414 rc = hashtab_map(&match->permissions.table, get_permissions_callback, 3415 *perms); 3416 if (rc) 3417 goto err; 3418 3419out: 3420 return rc; 3421 3422err: 3423 for (i = 0; i < *nperms; i++) 3424 kfree((*perms)[i]); 3425 kfree(*perms); 3426 return rc; 3427} 3428 3429int security_get_reject_unknown(void) 3430{ 3431 struct selinux_policy *policy; 3432 int value; 3433 3434 if (!selinux_initialized()) 3435 return 0; 3436 3437 rcu_read_lock(); 3438 policy = rcu_dereference(selinux_state.policy); 3439 value = policy->policydb.reject_unknown; 3440 rcu_read_unlock(); 3441 return value; 3442} 3443 3444int security_get_allow_unknown(void) 3445{ 3446 struct selinux_policy *policy; 3447 int value; 3448 3449 if (!selinux_initialized()) 3450 return 0; 3451 3452 rcu_read_lock(); 3453 policy = rcu_dereference(selinux_state.policy); 3454 value = policy->policydb.allow_unknown; 3455 rcu_read_unlock(); 3456 return value; 3457} 3458 3459/** 3460 * security_policycap_supported - Check for a specific policy capability 3461 * @req_cap: capability 3462 * 3463 * Description: 3464 * This function queries the currently loaded policy to see if it supports the 3465 * capability specified by @req_cap. Returns true (1) if the capability is 3466 * supported, false (0) if it isn't supported. 3467 * 3468 */ 3469int security_policycap_supported(unsigned int req_cap) 3470{ 3471 struct selinux_policy *policy; 3472 int rc; 3473 3474 if (!selinux_initialized()) 3475 return 0; 3476 3477 rcu_read_lock(); 3478 policy = rcu_dereference(selinux_state.policy); 3479 rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); 3480 rcu_read_unlock(); 3481 3482 return rc; 3483} 3484 3485struct selinux_audit_rule { 3486 u32 au_seqno; 3487 struct context au_ctxt; 3488}; 3489 3490void selinux_audit_rule_free(void *vrule) 3491{ 3492 struct selinux_audit_rule *rule = vrule; 3493 3494 if (rule) { 3495 context_destroy(&rule->au_ctxt); 3496 kfree(rule); 3497 } 3498} 3499 3500int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 3501{ 3502 struct selinux_state *state = &selinux_state; 3503 struct selinux_policy *policy; 3504 struct policydb *policydb; 3505 struct selinux_audit_rule *tmprule; 3506 struct role_datum *roledatum; 3507 struct type_datum *typedatum; 3508 struct user_datum *userdatum; 3509 struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; 3510 int rc = 0; 3511 3512 *rule = NULL; 3513 3514 if (!selinux_initialized()) 3515 return -EOPNOTSUPP; 3516 3517 switch (field) { 3518 case AUDIT_SUBJ_USER: 3519 case AUDIT_SUBJ_ROLE: 3520 case AUDIT_SUBJ_TYPE: 3521 case AUDIT_OBJ_USER: 3522 case AUDIT_OBJ_ROLE: 3523 case AUDIT_OBJ_TYPE: 3524 /* only 'equals' and 'not equals' fit user, role, and type */ 3525 if (op != Audit_equal && op != Audit_not_equal) 3526 return -EINVAL; 3527 break; 3528 case AUDIT_SUBJ_SEN: 3529 case AUDIT_SUBJ_CLR: 3530 case AUDIT_OBJ_LEV_LOW: 3531 case AUDIT_OBJ_LEV_HIGH: 3532 /* we do not allow a range, indicated by the presence of '-' */ 3533 if (strchr(rulestr, '-')) 3534 return -EINVAL; 3535 break; 3536 default: 3537 /* only the above fields are valid */ 3538 return -EINVAL; 3539 } 3540 3541 tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); 3542 if (!tmprule) 3543 return -ENOMEM; 3544 context_init(&tmprule->au_ctxt); 3545 3546 rcu_read_lock(); 3547 policy = rcu_dereference(state->policy); 3548 policydb = &policy->policydb; 3549 tmprule->au_seqno = policy->latest_granting; 3550 switch (field) { 3551 case AUDIT_SUBJ_USER: 3552 case AUDIT_OBJ_USER: 3553 userdatum = symtab_search(&policydb->p_users, rulestr); 3554 if (!userdatum) { 3555 rc = -EINVAL; 3556 goto err; 3557 } 3558 tmprule->au_ctxt.user = userdatum->value; 3559 break; 3560 case AUDIT_SUBJ_ROLE: 3561 case AUDIT_OBJ_ROLE: 3562 roledatum = symtab_search(&policydb->p_roles, rulestr); 3563 if (!roledatum) { 3564 rc = -EINVAL; 3565 goto err; 3566 } 3567 tmprule->au_ctxt.role = roledatum->value; 3568 break; 3569 case AUDIT_SUBJ_TYPE: 3570 case AUDIT_OBJ_TYPE: 3571 typedatum = symtab_search(&policydb->p_types, rulestr); 3572 if (!typedatum) { 3573 rc = -EINVAL; 3574 goto err; 3575 } 3576 tmprule->au_ctxt.type = typedatum->value; 3577 break; 3578 case AUDIT_SUBJ_SEN: 3579 case AUDIT_SUBJ_CLR: 3580 case AUDIT_OBJ_LEV_LOW: 3581 case AUDIT_OBJ_LEV_HIGH: 3582 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, 3583 GFP_ATOMIC); 3584 if (rc) 3585 goto err; 3586 break; 3587 } 3588 rcu_read_unlock(); 3589 3590 *rule = tmprule; 3591 return 0; 3592 3593err: 3594 rcu_read_unlock(); 3595 selinux_audit_rule_free(tmprule); 3596 *rule = NULL; 3597 return rc; 3598} 3599 3600/* Check to see if the rule contains any selinux fields */ 3601int selinux_audit_rule_known(struct audit_krule *rule) 3602{ 3603 u32 i; 3604 3605 for (i = 0; i < rule->field_count; i++) { 3606 struct audit_field *f = &rule->fields[i]; 3607 switch (f->type) { 3608 case AUDIT_SUBJ_USER: 3609 case AUDIT_SUBJ_ROLE: 3610 case AUDIT_SUBJ_TYPE: 3611 case AUDIT_SUBJ_SEN: 3612 case AUDIT_SUBJ_CLR: 3613 case AUDIT_OBJ_USER: 3614 case AUDIT_OBJ_ROLE: 3615 case AUDIT_OBJ_TYPE: 3616 case AUDIT_OBJ_LEV_LOW: 3617 case AUDIT_OBJ_LEV_HIGH: 3618 return 1; 3619 } 3620 } 3621 3622 return 0; 3623} 3624 3625int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) 3626{ 3627 struct selinux_state *state = &selinux_state; 3628 struct selinux_policy *policy; 3629 struct context *ctxt; 3630 struct mls_level *level; 3631 struct selinux_audit_rule *rule = vrule; 3632 int match = 0; 3633 3634 if (unlikely(!rule)) { 3635 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); 3636 return -ENOENT; 3637 } 3638 3639 if (!selinux_initialized()) 3640 return 0; 3641 3642 rcu_read_lock(); 3643 3644 policy = rcu_dereference(state->policy); 3645 3646 if (rule->au_seqno < policy->latest_granting) { 3647 match = -ESTALE; 3648 goto out; 3649 } 3650 3651 ctxt = sidtab_search(policy->sidtab, sid); 3652 if (unlikely(!ctxt)) { 3653 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", 3654 sid); 3655 match = -ENOENT; 3656 goto out; 3657 } 3658 3659 /* a field/op pair that is not caught here will simply fall through 3660 without a match */ 3661 switch (field) { 3662 case AUDIT_SUBJ_USER: 3663 case AUDIT_OBJ_USER: 3664 switch (op) { 3665 case Audit_equal: 3666 match = (ctxt->user == rule->au_ctxt.user); 3667 break; 3668 case Audit_not_equal: 3669 match = (ctxt->user != rule->au_ctxt.user); 3670 break; 3671 } 3672 break; 3673 case AUDIT_SUBJ_ROLE: 3674 case AUDIT_OBJ_ROLE: 3675 switch (op) { 3676 case Audit_equal: 3677 match = (ctxt->role == rule->au_ctxt.role); 3678 break; 3679 case Audit_not_equal: 3680 match = (ctxt->role != rule->au_ctxt.role); 3681 break; 3682 } 3683 break; 3684 case AUDIT_SUBJ_TYPE: 3685 case AUDIT_OBJ_TYPE: 3686 switch (op) { 3687 case Audit_equal: 3688 match = (ctxt->type == rule->au_ctxt.type); 3689 break; 3690 case Audit_not_equal: 3691 match = (ctxt->type != rule->au_ctxt.type); 3692 break; 3693 } 3694 break; 3695 case AUDIT_SUBJ_SEN: 3696 case AUDIT_SUBJ_CLR: 3697 case AUDIT_OBJ_LEV_LOW: 3698 case AUDIT_OBJ_LEV_HIGH: 3699 level = ((field == AUDIT_SUBJ_SEN || 3700 field == AUDIT_OBJ_LEV_LOW) ? 3701 &ctxt->range.level[0] : &ctxt->range.level[1]); 3702 switch (op) { 3703 case Audit_equal: 3704 match = mls_level_eq(&rule->au_ctxt.range.level[0], 3705 level); 3706 break; 3707 case Audit_not_equal: 3708 match = !mls_level_eq(&rule->au_ctxt.range.level[0], 3709 level); 3710 break; 3711 case Audit_lt: 3712 match = (mls_level_dom(&rule->au_ctxt.range.level[0], 3713 level) && 3714 !mls_level_eq(&rule->au_ctxt.range.level[0], 3715 level)); 3716 break; 3717 case Audit_le: 3718 match = mls_level_dom(&rule->au_ctxt.range.level[0], 3719 level); 3720 break; 3721 case Audit_gt: 3722 match = (mls_level_dom(level, 3723 &rule->au_ctxt.range.level[0]) && 3724 !mls_level_eq(level, 3725 &rule->au_ctxt.range.level[0])); 3726 break; 3727 case Audit_ge: 3728 match = mls_level_dom(level, 3729 &rule->au_ctxt.range.level[0]); 3730 break; 3731 } 3732 } 3733 3734out: 3735 rcu_read_unlock(); 3736 return match; 3737} 3738 3739static int aurule_avc_callback(u32 event) 3740{ 3741 if (event == AVC_CALLBACK_RESET) 3742 return audit_update_lsm_rules(); 3743 return 0; 3744} 3745 3746static int __init aurule_init(void) 3747{ 3748 int err; 3749 3750 err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); 3751 if (err) 3752 panic("avc_add_callback() failed, error %d\n", err); 3753 3754 return err; 3755} 3756__initcall(aurule_init); 3757 3758#ifdef CONFIG_NETLABEL 3759/** 3760 * security_netlbl_cache_add - Add an entry to the NetLabel cache 3761 * @secattr: the NetLabel packet security attributes 3762 * @sid: the SELinux SID 3763 * 3764 * Description: 3765 * Attempt to cache the context in @ctx, which was derived from the packet in 3766 * @skb, in the NetLabel subsystem cache. This function assumes @secattr has 3767 * already been initialized. 3768 * 3769 */ 3770static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, 3771 u32 sid) 3772{ 3773 u32 *sid_cache; 3774 3775 sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); 3776 if (sid_cache == NULL) 3777 return; 3778 secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); 3779 if (secattr->cache == NULL) { 3780 kfree(sid_cache); 3781 return; 3782 } 3783 3784 *sid_cache = sid; 3785 secattr->cache->free = kfree; 3786 secattr->cache->data = sid_cache; 3787 secattr->flags |= NETLBL_SECATTR_CACHE; 3788} 3789 3790/** 3791 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID 3792 * @secattr: the NetLabel packet security attributes 3793 * @sid: the SELinux SID 3794 * 3795 * Description: 3796 * Convert the given NetLabel security attributes in @secattr into a 3797 * SELinux SID. If the @secattr field does not contain a full SELinux 3798 * SID/context then use SECINITSID_NETMSG as the foundation. If possible the 3799 * 'cache' field of @secattr is set and the CACHE flag is set; this is to 3800 * allow the @secattr to be used by NetLabel to cache the secattr to SID 3801 * conversion for future lookups. Returns zero on success, negative values on 3802 * failure. 3803 * 3804 */ 3805int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 3806 u32 *sid) 3807{ 3808 struct selinux_policy *policy; 3809 struct policydb *policydb; 3810 struct sidtab *sidtab; 3811 int rc; 3812 struct context *ctx; 3813 struct context ctx_new; 3814 3815 if (!selinux_initialized()) { 3816 *sid = SECSID_NULL; 3817 return 0; 3818 } 3819 3820retry: 3821 rc = 0; 3822 rcu_read_lock(); 3823 policy = rcu_dereference(selinux_state.policy); 3824 policydb = &policy->policydb; 3825 sidtab = policy->sidtab; 3826 3827 if (secattr->flags & NETLBL_SECATTR_CACHE) 3828 *sid = *(u32 *)secattr->cache->data; 3829 else if (secattr->flags & NETLBL_SECATTR_SECID) 3830 *sid = secattr->attr.secid; 3831 else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { 3832 rc = -EIDRM; 3833 ctx = sidtab_search(sidtab, SECINITSID_NETMSG); 3834 if (ctx == NULL) 3835 goto out; 3836 3837 context_init(&ctx_new); 3838 ctx_new.user = ctx->user; 3839 ctx_new.role = ctx->role; 3840 ctx_new.type = ctx->type; 3841 mls_import_netlbl_lvl(policydb, &ctx_new, secattr); 3842 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { 3843 rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); 3844 if (rc) 3845 goto out; 3846 } 3847 rc = -EIDRM; 3848 if (!mls_context_isvalid(policydb, &ctx_new)) { 3849 ebitmap_destroy(&ctx_new.range.level[0].cat); 3850 goto out; 3851 } 3852 3853 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); 3854 ebitmap_destroy(&ctx_new.range.level[0].cat); 3855 if (rc == -ESTALE) { 3856 rcu_read_unlock(); 3857 goto retry; 3858 } 3859 if (rc) 3860 goto out; 3861 3862 security_netlbl_cache_add(secattr, *sid); 3863 } else 3864 *sid = SECSID_NULL; 3865 3866out: 3867 rcu_read_unlock(); 3868 return rc; 3869} 3870 3871/** 3872 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr 3873 * @sid: the SELinux SID 3874 * @secattr: the NetLabel packet security attributes 3875 * 3876 * Description: 3877 * Convert the given SELinux SID in @sid into a NetLabel security attribute. 3878 * Returns zero on success, negative values on failure. 3879 * 3880 */ 3881int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) 3882{ 3883 struct selinux_policy *policy; 3884 struct policydb *policydb; 3885 int rc; 3886 struct context *ctx; 3887 3888 if (!selinux_initialized()) 3889 return 0; 3890 3891 rcu_read_lock(); 3892 policy = rcu_dereference(selinux_state.policy); 3893 policydb = &policy->policydb; 3894 3895 rc = -ENOENT; 3896 ctx = sidtab_search(policy->sidtab, sid); 3897 if (ctx == NULL) 3898 goto out; 3899 3900 rc = -ENOMEM; 3901 secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), 3902 GFP_ATOMIC); 3903 if (secattr->domain == NULL) 3904 goto out; 3905 3906 secattr->attr.secid = sid; 3907 secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; 3908 mls_export_netlbl_lvl(policydb, ctx, secattr); 3909 rc = mls_export_netlbl_cat(policydb, ctx, secattr); 3910out: 3911 rcu_read_unlock(); 3912 return rc; 3913} 3914#endif /* CONFIG_NETLABEL */ 3915 3916/** 3917 * __security_read_policy - read the policy. 3918 * @policy: SELinux policy 3919 * @data: binary policy data 3920 * @len: length of data in bytes 3921 * 3922 */ 3923static int __security_read_policy(struct selinux_policy *policy, 3924 void *data, size_t *len) 3925{ 3926 int rc; 3927 struct policy_file fp; 3928 3929 fp.data = data; 3930 fp.len = *len; 3931 3932 rc = policydb_write(&policy->policydb, &fp); 3933 if (rc) 3934 return rc; 3935 3936 *len = (unsigned long)fp.data - (unsigned long)data; 3937 return 0; 3938} 3939 3940/** 3941 * security_read_policy - read the policy. 3942 * @data: binary policy data 3943 * @len: length of data in bytes 3944 * 3945 */ 3946int security_read_policy(void **data, size_t *len) 3947{ 3948 struct selinux_state *state = &selinux_state; 3949 struct selinux_policy *policy; 3950 3951 policy = rcu_dereference_protected( 3952 state->policy, lockdep_is_held(&state->policy_mutex)); 3953 if (!policy) 3954 return -EINVAL; 3955 3956 *len = policy->policydb.len; 3957 *data = vmalloc_user(*len); 3958 if (!*data) 3959 return -ENOMEM; 3960 3961 return __security_read_policy(policy, *data, len); 3962} 3963 3964/** 3965 * security_read_state_kernel - read the policy. 3966 * @data: binary policy data 3967 * @len: length of data in bytes 3968 * 3969 * Allocates kernel memory for reading SELinux policy. 3970 * This function is for internal use only and should not 3971 * be used for returning data to user space. 3972 * 3973 * This function must be called with policy_mutex held. 3974 */ 3975int security_read_state_kernel(void **data, size_t *len) 3976{ 3977 int err; 3978 struct selinux_state *state = &selinux_state; 3979 struct selinux_policy *policy; 3980 3981 policy = rcu_dereference_protected( 3982 state->policy, lockdep_is_held(&state->policy_mutex)); 3983 if (!policy) 3984 return -EINVAL; 3985 3986 *len = policy->policydb.len; 3987 *data = vmalloc(*len); 3988 if (!*data) 3989 return -ENOMEM; 3990 3991 err = __security_read_policy(policy, *data, len); 3992 if (err) { 3993 vfree(*data); 3994 *data = NULL; 3995 *len = 0; 3996 } 3997 return err; 3998} 3999