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1/* 2 * Implementation of the security services. 3 * 4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil> 5 * James Morris <jmorris@redhat.com> 6 * 7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> 8 * 9 * Support for enhanced MLS infrastructure. 10 * 11 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> 12 * 13 * Added conditional policy language extensions 14 * 15 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. 16 * Copyright (C) 2003 - 2004 Tresys Technology, LLC 17 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> 18 * This program is free software; you can redistribute it and/or modify 19 * it under the terms of the GNU General Public License as published by 20 * the Free Software Foundation, version 2. 21 */ 22#include <linux/kernel.h> 23#include <linux/slab.h> 24#include <linux/string.h> 25#include <linux/spinlock.h> 26#include <linux/errno.h> 27#include <linux/in.h> 28#include <linux/sched.h> 29#include <linux/audit.h> 30#include <asm/semaphore.h> 31#include "flask.h" 32#include "avc.h" 33#include "avc_ss.h" 34#include "security.h" 35#include "context.h" 36#include "policydb.h" 37#include "sidtab.h" 38#include "services.h" 39#include "conditional.h" 40#include "mls.h" 41 42extern void selnl_notify_policyload(u32 seqno); 43unsigned int policydb_loaded_version; 44 45static DEFINE_RWLOCK(policy_rwlock); 46#define POLICY_RDLOCK read_lock(&policy_rwlock) 47#define POLICY_WRLOCK write_lock_irq(&policy_rwlock) 48#define POLICY_RDUNLOCK read_unlock(&policy_rwlock) 49#define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock) 50 51static DECLARE_MUTEX(load_sem); 52#define LOAD_LOCK down(&load_sem) 53#define LOAD_UNLOCK up(&load_sem) 54 55static struct sidtab sidtab; 56struct policydb policydb; 57int ss_initialized = 0; 58 59/* 60 * The largest sequence number that has been used when 61 * providing an access decision to the access vector cache. 62 * The sequence number only changes when a policy change 63 * occurs. 64 */ 65static u32 latest_granting = 0; 66 67/* Forward declaration. */ 68static int context_struct_to_string(struct context *context, char **scontext, 69 u32 *scontext_len); 70 71/* 72 * Return the boolean value of a constraint expression 73 * when it is applied to the specified source and target 74 * security contexts. 75 * 76 * xcontext is a special beast... It is used by the validatetrans rules 77 * only. For these rules, scontext is the context before the transition, 78 * tcontext is the context after the transition, and xcontext is the context 79 * of the process performing the transition. All other callers of 80 * constraint_expr_eval should pass in NULL for xcontext. 81 */ 82static int constraint_expr_eval(struct context *scontext, 83 struct context *tcontext, 84 struct context *xcontext, 85 struct constraint_expr *cexpr) 86{ 87 u32 val1, val2; 88 struct context *c; 89 struct role_datum *r1, *r2; 90 struct mls_level *l1, *l2; 91 struct constraint_expr *e; 92 int s[CEXPR_MAXDEPTH]; 93 int sp = -1; 94 95 for (e = cexpr; e; e = e->next) { 96 switch (e->expr_type) { 97 case CEXPR_NOT: 98 BUG_ON(sp < 0); 99 s[sp] = !s[sp]; 100 break; 101 case CEXPR_AND: 102 BUG_ON(sp < 1); 103 sp--; 104 s[sp] &= s[sp+1]; 105 break; 106 case CEXPR_OR: 107 BUG_ON(sp < 1); 108 sp--; 109 s[sp] |= s[sp+1]; 110 break; 111 case CEXPR_ATTR: 112 if (sp == (CEXPR_MAXDEPTH-1)) 113 return 0; 114 switch (e->attr) { 115 case CEXPR_USER: 116 val1 = scontext->user; 117 val2 = tcontext->user; 118 break; 119 case CEXPR_TYPE: 120 val1 = scontext->type; 121 val2 = tcontext->type; 122 break; 123 case CEXPR_ROLE: 124 val1 = scontext->role; 125 val2 = tcontext->role; 126 r1 = policydb.role_val_to_struct[val1 - 1]; 127 r2 = policydb.role_val_to_struct[val2 - 1]; 128 switch (e->op) { 129 case CEXPR_DOM: 130 s[++sp] = ebitmap_get_bit(&r1->dominates, 131 val2 - 1); 132 continue; 133 case CEXPR_DOMBY: 134 s[++sp] = ebitmap_get_bit(&r2->dominates, 135 val1 - 1); 136 continue; 137 case CEXPR_INCOMP: 138 s[++sp] = ( !ebitmap_get_bit(&r1->dominates, 139 val2 - 1) && 140 !ebitmap_get_bit(&r2->dominates, 141 val1 - 1) ); 142 continue; 143 default: 144 break; 145 } 146 break; 147 case CEXPR_L1L2: 148 l1 = &(scontext->range.level[0]); 149 l2 = &(tcontext->range.level[0]); 150 goto mls_ops; 151 case CEXPR_L1H2: 152 l1 = &(scontext->range.level[0]); 153 l2 = &(tcontext->range.level[1]); 154 goto mls_ops; 155 case CEXPR_H1L2: 156 l1 = &(scontext->range.level[1]); 157 l2 = &(tcontext->range.level[0]); 158 goto mls_ops; 159 case CEXPR_H1H2: 160 l1 = &(scontext->range.level[1]); 161 l2 = &(tcontext->range.level[1]); 162 goto mls_ops; 163 case CEXPR_L1H1: 164 l1 = &(scontext->range.level[0]); 165 l2 = &(scontext->range.level[1]); 166 goto mls_ops; 167 case CEXPR_L2H2: 168 l1 = &(tcontext->range.level[0]); 169 l2 = &(tcontext->range.level[1]); 170 goto mls_ops; 171mls_ops: 172 switch (e->op) { 173 case CEXPR_EQ: 174 s[++sp] = mls_level_eq(l1, l2); 175 continue; 176 case CEXPR_NEQ: 177 s[++sp] = !mls_level_eq(l1, l2); 178 continue; 179 case CEXPR_DOM: 180 s[++sp] = mls_level_dom(l1, l2); 181 continue; 182 case CEXPR_DOMBY: 183 s[++sp] = mls_level_dom(l2, l1); 184 continue; 185 case CEXPR_INCOMP: 186 s[++sp] = mls_level_incomp(l2, l1); 187 continue; 188 default: 189 BUG(); 190 return 0; 191 } 192 break; 193 default: 194 BUG(); 195 return 0; 196 } 197 198 switch (e->op) { 199 case CEXPR_EQ: 200 s[++sp] = (val1 == val2); 201 break; 202 case CEXPR_NEQ: 203 s[++sp] = (val1 != val2); 204 break; 205 default: 206 BUG(); 207 return 0; 208 } 209 break; 210 case CEXPR_NAMES: 211 if (sp == (CEXPR_MAXDEPTH-1)) 212 return 0; 213 c = scontext; 214 if (e->attr & CEXPR_TARGET) 215 c = tcontext; 216 else if (e->attr & CEXPR_XTARGET) { 217 c = xcontext; 218 if (!c) { 219 BUG(); 220 return 0; 221 } 222 } 223 if (e->attr & CEXPR_USER) 224 val1 = c->user; 225 else if (e->attr & CEXPR_ROLE) 226 val1 = c->role; 227 else if (e->attr & CEXPR_TYPE) 228 val1 = c->type; 229 else { 230 BUG(); 231 return 0; 232 } 233 234 switch (e->op) { 235 case CEXPR_EQ: 236 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); 237 break; 238 case CEXPR_NEQ: 239 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); 240 break; 241 default: 242 BUG(); 243 return 0; 244 } 245 break; 246 default: 247 BUG(); 248 return 0; 249 } 250 } 251 252 BUG_ON(sp != 0); 253 return s[0]; 254} 255 256/* 257 * Compute access vectors based on a context structure pair for 258 * the permissions in a particular class. 259 */ 260static int context_struct_compute_av(struct context *scontext, 261 struct context *tcontext, 262 u16 tclass, 263 u32 requested, 264 struct av_decision *avd) 265{ 266 struct constraint_node *constraint; 267 struct role_allow *ra; 268 struct avtab_key avkey; 269 struct avtab_datum *avdatum; 270 struct class_datum *tclass_datum; 271 272 /* 273 * Remap extended Netlink classes for old policy versions. 274 * Do this here rather than socket_type_to_security_class() 275 * in case a newer policy version is loaded, allowing sockets 276 * to remain in the correct class. 277 */ 278 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) 279 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && 280 tclass <= SECCLASS_NETLINK_DNRT_SOCKET) 281 tclass = SECCLASS_NETLINK_SOCKET; 282 283 if (!tclass || tclass > policydb.p_classes.nprim) { 284 printk(KERN_ERR "security_compute_av: unrecognized class %d\n", 285 tclass); 286 return -EINVAL; 287 } 288 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 289 290 /* 291 * Initialize the access vectors to the default values. 292 */ 293 avd->allowed = 0; 294 avd->decided = 0xffffffff; 295 avd->auditallow = 0; 296 avd->auditdeny = 0xffffffff; 297 avd->seqno = latest_granting; 298 299 /* 300 * If a specific type enforcement rule was defined for 301 * this permission check, then use it. 302 */ 303 avkey.source_type = scontext->type; 304 avkey.target_type = tcontext->type; 305 avkey.target_class = tclass; 306 avdatum = avtab_search(&policydb.te_avtab, &avkey, AVTAB_AV); 307 if (avdatum) { 308 if (avdatum->specified & AVTAB_ALLOWED) 309 avd->allowed = avtab_allowed(avdatum); 310 if (avdatum->specified & AVTAB_AUDITDENY) 311 avd->auditdeny = avtab_auditdeny(avdatum); 312 if (avdatum->specified & AVTAB_AUDITALLOW) 313 avd->auditallow = avtab_auditallow(avdatum); 314 } 315 316 /* Check conditional av table for additional permissions */ 317 cond_compute_av(&policydb.te_cond_avtab, &avkey, avd); 318 319 /* 320 * Remove any permissions prohibited by a constraint (this includes 321 * the MLS policy). 322 */ 323 constraint = tclass_datum->constraints; 324 while (constraint) { 325 if ((constraint->permissions & (avd->allowed)) && 326 !constraint_expr_eval(scontext, tcontext, NULL, 327 constraint->expr)) { 328 avd->allowed = (avd->allowed) & ~(constraint->permissions); 329 } 330 constraint = constraint->next; 331 } 332 333 /* 334 * If checking process transition permission and the 335 * role is changing, then check the (current_role, new_role) 336 * pair. 337 */ 338 if (tclass == SECCLASS_PROCESS && 339 (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) && 340 scontext->role != tcontext->role) { 341 for (ra = policydb.role_allow; ra; ra = ra->next) { 342 if (scontext->role == ra->role && 343 tcontext->role == ra->new_role) 344 break; 345 } 346 if (!ra) 347 avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION | 348 PROCESS__DYNTRANSITION); 349 } 350 351 return 0; 352} 353 354static int security_validtrans_handle_fail(struct context *ocontext, 355 struct context *ncontext, 356 struct context *tcontext, 357 u16 tclass) 358{ 359 char *o = NULL, *n = NULL, *t = NULL; 360 u32 olen, nlen, tlen; 361 362 if (context_struct_to_string(ocontext, &o, &olen) < 0) 363 goto out; 364 if (context_struct_to_string(ncontext, &n, &nlen) < 0) 365 goto out; 366 if (context_struct_to_string(tcontext, &t, &tlen) < 0) 367 goto out; 368 audit_log(current->audit_context, AUDIT_SELINUX_ERR, 369 "security_validate_transition: denied for" 370 " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", 371 o, n, t, policydb.p_class_val_to_name[tclass-1]); 372out: 373 kfree(o); 374 kfree(n); 375 kfree(t); 376 377 if (!selinux_enforcing) 378 return 0; 379 return -EPERM; 380} 381 382int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, 383 u16 tclass) 384{ 385 struct context *ocontext; 386 struct context *ncontext; 387 struct context *tcontext; 388 struct class_datum *tclass_datum; 389 struct constraint_node *constraint; 390 int rc = 0; 391 392 if (!ss_initialized) 393 return 0; 394 395 POLICY_RDLOCK; 396 397 /* 398 * Remap extended Netlink classes for old policy versions. 399 * Do this here rather than socket_type_to_security_class() 400 * in case a newer policy version is loaded, allowing sockets 401 * to remain in the correct class. 402 */ 403 if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) 404 if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && 405 tclass <= SECCLASS_NETLINK_DNRT_SOCKET) 406 tclass = SECCLASS_NETLINK_SOCKET; 407 408 if (!tclass || tclass > policydb.p_classes.nprim) { 409 printk(KERN_ERR "security_validate_transition: " 410 "unrecognized class %d\n", tclass); 411 rc = -EINVAL; 412 goto out; 413 } 414 tclass_datum = policydb.class_val_to_struct[tclass - 1]; 415 416 ocontext = sidtab_search(&sidtab, oldsid); 417 if (!ocontext) { 418 printk(KERN_ERR "security_validate_transition: " 419 " unrecognized SID %d\n", oldsid); 420 rc = -EINVAL; 421 goto out; 422 } 423 424 ncontext = sidtab_search(&sidtab, newsid); 425 if (!ncontext) { 426 printk(KERN_ERR "security_validate_transition: " 427 " unrecognized SID %d\n", newsid); 428 rc = -EINVAL; 429 goto out; 430 } 431 432 tcontext = sidtab_search(&sidtab, tasksid); 433 if (!tcontext) { 434 printk(KERN_ERR "security_validate_transition: " 435 " unrecognized SID %d\n", tasksid); 436 rc = -EINVAL; 437 goto out; 438 } 439 440 constraint = tclass_datum->validatetrans; 441 while (constraint) { 442 if (!constraint_expr_eval(ocontext, ncontext, tcontext, 443 constraint->expr)) { 444 rc = security_validtrans_handle_fail(ocontext, ncontext, 445 tcontext, tclass); 446 goto out; 447 } 448 constraint = constraint->next; 449 } 450 451out: 452 POLICY_RDUNLOCK; 453 return rc; 454} 455 456/** 457 * security_compute_av - Compute access vector decisions. 458 * @ssid: source security identifier 459 * @tsid: target security identifier 460 * @tclass: target security class 461 * @requested: requested permissions 462 * @avd: access vector decisions 463 * 464 * Compute a set of access vector decisions based on the 465 * SID pair (@ssid, @tsid) for the permissions in @tclass. 466 * Return -%EINVAL if any of the parameters are invalid or %0 467 * if the access vector decisions were computed successfully. 468 */ 469int security_compute_av(u32 ssid, 470 u32 tsid, 471 u16 tclass, 472 u32 requested, 473 struct av_decision *avd) 474{ 475 struct context *scontext = NULL, *tcontext = NULL; 476 int rc = 0; 477 478 if (!ss_initialized) { 479 avd->allowed = 0xffffffff; 480 avd->decided = 0xffffffff; 481 avd->auditallow = 0; 482 avd->auditdeny = 0xffffffff; 483 avd->seqno = latest_granting; 484 return 0; 485 } 486 487 POLICY_RDLOCK; 488 489 scontext = sidtab_search(&sidtab, ssid); 490 if (!scontext) { 491 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n", 492 ssid); 493 rc = -EINVAL; 494 goto out; 495 } 496 tcontext = sidtab_search(&sidtab, tsid); 497 if (!tcontext) { 498 printk(KERN_ERR "security_compute_av: unrecognized SID %d\n", 499 tsid); 500 rc = -EINVAL; 501 goto out; 502 } 503 504 rc = context_struct_compute_av(scontext, tcontext, tclass, 505 requested, avd); 506out: 507 POLICY_RDUNLOCK; 508 return rc; 509} 510 511/* 512 * Write the security context string representation of 513 * the context structure `context' into a dynamically 514 * allocated string of the correct size. Set `*scontext' 515 * to point to this string and set `*scontext_len' to 516 * the length of the string. 517 */ 518static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) 519{ 520 char *scontextp; 521 522 *scontext = NULL; 523 *scontext_len = 0; 524 525 /* Compute the size of the context. */ 526 *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1; 527 *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1; 528 *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1; 529 *scontext_len += mls_compute_context_len(context); 530 531 /* Allocate space for the context; caller must free this space. */ 532 scontextp = kmalloc(*scontext_len, GFP_ATOMIC); 533 if (!scontextp) { 534 return -ENOMEM; 535 } 536 *scontext = scontextp; 537 538 /* 539 * Copy the user name, role name and type name into the context. 540 */ 541 sprintf(scontextp, "%s:%s:%s", 542 policydb.p_user_val_to_name[context->user - 1], 543 policydb.p_role_val_to_name[context->role - 1], 544 policydb.p_type_val_to_name[context->type - 1]); 545 scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) + 546 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) + 547 1 + strlen(policydb.p_type_val_to_name[context->type - 1]); 548 549 mls_sid_to_context(context, &scontextp); 550 551 *scontextp = 0; 552 553 return 0; 554} 555 556#include "initial_sid_to_string.h" 557 558/** 559 * security_sid_to_context - Obtain a context for a given SID. 560 * @sid: security identifier, SID 561 * @scontext: security context 562 * @scontext_len: length in bytes 563 * 564 * Write the string representation of the context associated with @sid 565 * into a dynamically allocated string of the correct size. Set @scontext 566 * to point to this string and set @scontext_len to the length of the string. 567 */ 568int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) 569{ 570 struct context *context; 571 int rc = 0; 572 573 if (!ss_initialized) { 574 if (sid <= SECINITSID_NUM) { 575 char *scontextp; 576 577 *scontext_len = strlen(initial_sid_to_string[sid]) + 1; 578 scontextp = kmalloc(*scontext_len,GFP_ATOMIC); 579 strcpy(scontextp, initial_sid_to_string[sid]); 580 *scontext = scontextp; 581 goto out; 582 } 583 printk(KERN_ERR "security_sid_to_context: called before initial " 584 "load_policy on unknown SID %d\n", sid); 585 rc = -EINVAL; 586 goto out; 587 } 588 POLICY_RDLOCK; 589 context = sidtab_search(&sidtab, sid); 590 if (!context) { 591 printk(KERN_ERR "security_sid_to_context: unrecognized SID " 592 "%d\n", sid); 593 rc = -EINVAL; 594 goto out_unlock; 595 } 596 rc = context_struct_to_string(context, scontext, scontext_len); 597out_unlock: 598 POLICY_RDUNLOCK; 599out: 600 return rc; 601 602} 603 604static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid) 605{ 606 char *scontext2; 607 struct context context; 608 struct role_datum *role; 609 struct type_datum *typdatum; 610 struct user_datum *usrdatum; 611 char *scontextp, *p, oldc; 612 int rc = 0; 613 614 if (!ss_initialized) { 615 int i; 616 617 for (i = 1; i < SECINITSID_NUM; i++) { 618 if (!strcmp(initial_sid_to_string[i], scontext)) { 619 *sid = i; 620 goto out; 621 } 622 } 623 *sid = SECINITSID_KERNEL; 624 goto out; 625 } 626 *sid = SECSID_NULL; 627 628 /* Copy the string so that we can modify the copy as we parse it. 629 The string should already by null terminated, but we append a 630 null suffix to the copy to avoid problems with the existing 631 attr package, which doesn't view the null terminator as part 632 of the attribute value. */ 633 scontext2 = kmalloc(scontext_len+1,GFP_KERNEL); 634 if (!scontext2) { 635 rc = -ENOMEM; 636 goto out; 637 } 638 memcpy(scontext2, scontext, scontext_len); 639 scontext2[scontext_len] = 0; 640 641 context_init(&context); 642 *sid = SECSID_NULL; 643 644 POLICY_RDLOCK; 645 646 /* Parse the security context. */ 647 648 rc = -EINVAL; 649 scontextp = (char *) scontext2; 650 651 /* Extract the user. */ 652 p = scontextp; 653 while (*p && *p != ':') 654 p++; 655 656 if (*p == 0) 657 goto out_unlock; 658 659 *p++ = 0; 660 661 usrdatum = hashtab_search(policydb.p_users.table, scontextp); 662 if (!usrdatum) 663 goto out_unlock; 664 665 context.user = usrdatum->value; 666 667 /* Extract role. */ 668 scontextp = p; 669 while (*p && *p != ':') 670 p++; 671 672 if (*p == 0) 673 goto out_unlock; 674 675 *p++ = 0; 676 677 role = hashtab_search(policydb.p_roles.table, scontextp); 678 if (!role) 679 goto out_unlock; 680 context.role = role->value; 681 682 /* Extract type. */ 683 scontextp = p; 684 while (*p && *p != ':') 685 p++; 686 oldc = *p; 687 *p++ = 0; 688 689 typdatum = hashtab_search(policydb.p_types.table, scontextp); 690 if (!typdatum) 691 goto out_unlock; 692 693 context.type = typdatum->value; 694 695 rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid); 696 if (rc) 697 goto out_unlock; 698 699 if ((p - scontext2) < scontext_len) { 700 rc = -EINVAL; 701 goto out_unlock; 702 } 703 704 /* Check the validity of the new context. */ 705 if (!policydb_context_isvalid(&policydb, &context)) { 706 rc = -EINVAL; 707 goto out_unlock; 708 } 709 /* Obtain the new sid. */ 710 rc = sidtab_context_to_sid(&sidtab, &context, sid); 711out_unlock: 712 POLICY_RDUNLOCK; 713 context_destroy(&context); 714 kfree(scontext2); 715out: 716 return rc; 717} 718 719/** 720 * security_context_to_sid - Obtain a SID for a given security context. 721 * @scontext: security context 722 * @scontext_len: length in bytes 723 * @sid: security identifier, SID 724 * 725 * Obtains a SID associated with the security context that 726 * has the string representation specified by @scontext. 727 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 728 * memory is available, or 0 on success. 729 */ 730int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid) 731{ 732 return security_context_to_sid_core(scontext, scontext_len, 733 sid, SECSID_NULL); 734} 735 736/** 737 * security_context_to_sid_default - Obtain a SID for a given security context, 738 * falling back to specified default if needed. 739 * 740 * @scontext: security context 741 * @scontext_len: length in bytes 742 * @sid: security identifier, SID 743 * @def_sid: default SID to assign on errror 744 * 745 * Obtains a SID associated with the security context that 746 * has the string representation specified by @scontext. 747 * The default SID is passed to the MLS layer to be used to allow 748 * kernel labeling of the MLS field if the MLS field is not present 749 * (for upgrading to MLS without full relabel). 750 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient 751 * memory is available, or 0 on success. 752 */ 753int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid) 754{ 755 return security_context_to_sid_core(scontext, scontext_len, 756 sid, def_sid); 757} 758 759static int compute_sid_handle_invalid_context( 760 struct context *scontext, 761 struct context *tcontext, 762 u16 tclass, 763 struct context *newcontext) 764{ 765 char *s = NULL, *t = NULL, *n = NULL; 766 u32 slen, tlen, nlen; 767 768 if (context_struct_to_string(scontext, &s, &slen) < 0) 769 goto out; 770 if (context_struct_to_string(tcontext, &t, &tlen) < 0) 771 goto out; 772 if (context_struct_to_string(newcontext, &n, &nlen) < 0) 773 goto out; 774 audit_log(current->audit_context, AUDIT_SELINUX_ERR, 775 "security_compute_sid: invalid context %s" 776 " for scontext=%s" 777 " tcontext=%s" 778 " tclass=%s", 779 n, s, t, policydb.p_class_val_to_name[tclass-1]); 780out: 781 kfree(s); 782 kfree(t); 783 kfree(n); 784 if (!selinux_enforcing) 785 return 0; 786 return -EACCES; 787} 788 789static int security_compute_sid(u32 ssid, 790 u32 tsid, 791 u16 tclass, 792 u32 specified, 793 u32 *out_sid) 794{ 795 struct context *scontext = NULL, *tcontext = NULL, newcontext; 796 struct role_trans *roletr = NULL; 797 struct avtab_key avkey; 798 struct avtab_datum *avdatum; 799 struct avtab_node *node; 800 unsigned int type_change = 0; 801 int rc = 0; 802 803 if (!ss_initialized) { 804 switch (tclass) { 805 case SECCLASS_PROCESS: 806 *out_sid = ssid; 807 break; 808 default: 809 *out_sid = tsid; 810 break; 811 } 812 goto out; 813 } 814 815 POLICY_RDLOCK; 816 817 scontext = sidtab_search(&sidtab, ssid); 818 if (!scontext) { 819 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n", 820 ssid); 821 rc = -EINVAL; 822 goto out_unlock; 823 } 824 tcontext = sidtab_search(&sidtab, tsid); 825 if (!tcontext) { 826 printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n", 827 tsid); 828 rc = -EINVAL; 829 goto out_unlock; 830 } 831 832 context_init(&newcontext); 833 834 /* Set the user identity. */ 835 switch (specified) { 836 case AVTAB_TRANSITION: 837 case AVTAB_CHANGE: 838 /* Use the process user identity. */ 839 newcontext.user = scontext->user; 840 break; 841 case AVTAB_MEMBER: 842 /* Use the related object owner. */ 843 newcontext.user = tcontext->user; 844 break; 845 } 846 847 /* Set the role and type to default values. */ 848 switch (tclass) { 849 case SECCLASS_PROCESS: 850 /* Use the current role and type of process. */ 851 newcontext.role = scontext->role; 852 newcontext.type = scontext->type; 853 break; 854 default: 855 /* Use the well-defined object role. */ 856 newcontext.role = OBJECT_R_VAL; 857 /* Use the type of the related object. */ 858 newcontext.type = tcontext->type; 859 } 860 861 /* Look for a type transition/member/change rule. */ 862 avkey.source_type = scontext->type; 863 avkey.target_type = tcontext->type; 864 avkey.target_class = tclass; 865 avdatum = avtab_search(&policydb.te_avtab, &avkey, AVTAB_TYPE); 866 867 /* If no permanent rule, also check for enabled conditional rules */ 868 if(!avdatum) { 869 node = avtab_search_node(&policydb.te_cond_avtab, &avkey, specified); 870 for (; node != NULL; node = avtab_search_node_next(node, specified)) { 871 if (node->datum.specified & AVTAB_ENABLED) { 872 avdatum = &node->datum; 873 break; 874 } 875 } 876 } 877 878 type_change = (avdatum && (avdatum->specified & specified)); 879 if (type_change) { 880 /* Use the type from the type transition/member/change rule. */ 881 switch (specified) { 882 case AVTAB_TRANSITION: 883 newcontext.type = avtab_transition(avdatum); 884 break; 885 case AVTAB_MEMBER: 886 newcontext.type = avtab_member(avdatum); 887 break; 888 case AVTAB_CHANGE: 889 newcontext.type = avtab_change(avdatum); 890 break; 891 } 892 } 893 894 /* Check for class-specific changes. */ 895 switch (tclass) { 896 case SECCLASS_PROCESS: 897 if (specified & AVTAB_TRANSITION) { 898 /* Look for a role transition rule. */ 899 for (roletr = policydb.role_tr; roletr; 900 roletr = roletr->next) { 901 if (roletr->role == scontext->role && 902 roletr->type == tcontext->type) { 903 /* Use the role transition rule. */ 904 newcontext.role = roletr->new_role; 905 break; 906 } 907 } 908 } 909 break; 910 default: 911 break; 912 } 913 914 /* Set the MLS attributes. 915 This is done last because it may allocate memory. */ 916 rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext); 917 if (rc) 918 goto out_unlock; 919 920 /* Check the validity of the context. */ 921 if (!policydb_context_isvalid(&policydb, &newcontext)) { 922 rc = compute_sid_handle_invalid_context(scontext, 923 tcontext, 924 tclass, 925 &newcontext); 926 if (rc) 927 goto out_unlock; 928 } 929 /* Obtain the sid for the context. */ 930 rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); 931out_unlock: 932 POLICY_RDUNLOCK; 933 context_destroy(&newcontext); 934out: 935 return rc; 936} 937 938/** 939 * security_transition_sid - Compute the SID for a new subject/object. 940 * @ssid: source security identifier 941 * @tsid: target security identifier 942 * @tclass: target security class 943 * @out_sid: security identifier for new subject/object 944 * 945 * Compute a SID to use for labeling a new subject or object in the 946 * class @tclass based on a SID pair (@ssid, @tsid). 947 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 948 * if insufficient memory is available, or %0 if the new SID was 949 * computed successfully. 950 */ 951int security_transition_sid(u32 ssid, 952 u32 tsid, 953 u16 tclass, 954 u32 *out_sid) 955{ 956 return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid); 957} 958 959/** 960 * security_member_sid - Compute the SID for member selection. 961 * @ssid: source security identifier 962 * @tsid: target security identifier 963 * @tclass: target security class 964 * @out_sid: security identifier for selected member 965 * 966 * Compute a SID to use when selecting a member of a polyinstantiated 967 * object of class @tclass based on a SID pair (@ssid, @tsid). 968 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 969 * if insufficient memory is available, or %0 if the SID was 970 * computed successfully. 971 */ 972int security_member_sid(u32 ssid, 973 u32 tsid, 974 u16 tclass, 975 u32 *out_sid) 976{ 977 return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid); 978} 979 980/** 981 * security_change_sid - Compute the SID for object relabeling. 982 * @ssid: source security identifier 983 * @tsid: target security identifier 984 * @tclass: target security class 985 * @out_sid: security identifier for selected member 986 * 987 * Compute a SID to use for relabeling an object of class @tclass 988 * based on a SID pair (@ssid, @tsid). 989 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM 990 * if insufficient memory is available, or %0 if the SID was 991 * computed successfully. 992 */ 993int security_change_sid(u32 ssid, 994 u32 tsid, 995 u16 tclass, 996 u32 *out_sid) 997{ 998 return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid); 999} 1000 1001/* 1002 * Verify that each permission that is defined under the 1003 * existing policy is still defined with the same value 1004 * in the new policy. 1005 */ 1006static int validate_perm(void *key, void *datum, void *p) 1007{ 1008 struct hashtab *h; 1009 struct perm_datum *perdatum, *perdatum2; 1010 int rc = 0; 1011 1012 1013 h = p; 1014 perdatum = datum; 1015 1016 perdatum2 = hashtab_search(h, key); 1017 if (!perdatum2) { 1018 printk(KERN_ERR "security: permission %s disappeared", 1019 (char *)key); 1020 rc = -ENOENT; 1021 goto out; 1022 } 1023 if (perdatum->value != perdatum2->value) { 1024 printk(KERN_ERR "security: the value of permission %s changed", 1025 (char *)key); 1026 rc = -EINVAL; 1027 } 1028out: 1029 return rc; 1030} 1031 1032/* 1033 * Verify that each class that is defined under the 1034 * existing policy is still defined with the same 1035 * attributes in the new policy. 1036 */ 1037static int validate_class(void *key, void *datum, void *p) 1038{ 1039 struct policydb *newp; 1040 struct class_datum *cladatum, *cladatum2; 1041 int rc; 1042 1043 newp = p; 1044 cladatum = datum; 1045 1046 cladatum2 = hashtab_search(newp->p_classes.table, key); 1047 if (!cladatum2) { 1048 printk(KERN_ERR "security: class %s disappeared\n", 1049 (char *)key); 1050 rc = -ENOENT; 1051 goto out; 1052 } 1053 if (cladatum->value != cladatum2->value) { 1054 printk(KERN_ERR "security: the value of class %s changed\n", 1055 (char *)key); 1056 rc = -EINVAL; 1057 goto out; 1058 } 1059 if ((cladatum->comdatum && !cladatum2->comdatum) || 1060 (!cladatum->comdatum && cladatum2->comdatum)) { 1061 printk(KERN_ERR "security: the inherits clause for the access " 1062 "vector definition for class %s changed\n", (char *)key); 1063 rc = -EINVAL; 1064 goto out; 1065 } 1066 if (cladatum->comdatum) { 1067 rc = hashtab_map(cladatum->comdatum->permissions.table, validate_perm, 1068 cladatum2->comdatum->permissions.table); 1069 if (rc) { 1070 printk(" in the access vector definition for class " 1071 "%s\n", (char *)key); 1072 goto out; 1073 } 1074 } 1075 rc = hashtab_map(cladatum->permissions.table, validate_perm, 1076 cladatum2->permissions.table); 1077 if (rc) 1078 printk(" in access vector definition for class %s\n", 1079 (char *)key); 1080out: 1081 return rc; 1082} 1083 1084/* Clone the SID into the new SID table. */ 1085static int clone_sid(u32 sid, 1086 struct context *context, 1087 void *arg) 1088{ 1089 struct sidtab *s = arg; 1090 1091 return sidtab_insert(s, sid, context); 1092} 1093 1094static inline int convert_context_handle_invalid_context(struct context *context) 1095{ 1096 int rc = 0; 1097 1098 if (selinux_enforcing) { 1099 rc = -EINVAL; 1100 } else { 1101 char *s; 1102 u32 len; 1103 1104 context_struct_to_string(context, &s, &len); 1105 printk(KERN_ERR "security: context %s is invalid\n", s); 1106 kfree(s); 1107 } 1108 return rc; 1109} 1110 1111struct convert_context_args { 1112 struct policydb *oldp; 1113 struct policydb *newp; 1114}; 1115 1116/* 1117 * Convert the values in the security context 1118 * structure `c' from the values specified 1119 * in the policy `p->oldp' to the values specified 1120 * in the policy `p->newp'. Verify that the 1121 * context is valid under the new policy. 1122 */ 1123static int convert_context(u32 key, 1124 struct context *c, 1125 void *p) 1126{ 1127 struct convert_context_args *args; 1128 struct context oldc; 1129 struct role_datum *role; 1130 struct type_datum *typdatum; 1131 struct user_datum *usrdatum; 1132 char *s; 1133 u32 len; 1134 int rc; 1135 1136 args = p; 1137 1138 rc = context_cpy(&oldc, c); 1139 if (rc) 1140 goto out; 1141 1142 rc = -EINVAL; 1143 1144 /* Convert the user. */ 1145 usrdatum = hashtab_search(args->newp->p_users.table, 1146 args->oldp->p_user_val_to_name[c->user - 1]); 1147 if (!usrdatum) { 1148 goto bad; 1149 } 1150 c->user = usrdatum->value; 1151 1152 /* Convert the role. */ 1153 role = hashtab_search(args->newp->p_roles.table, 1154 args->oldp->p_role_val_to_name[c->role - 1]); 1155 if (!role) { 1156 goto bad; 1157 } 1158 c->role = role->value; 1159 1160 /* Convert the type. */ 1161 typdatum = hashtab_search(args->newp->p_types.table, 1162 args->oldp->p_type_val_to_name[c->type - 1]); 1163 if (!typdatum) { 1164 goto bad; 1165 } 1166 c->type = typdatum->value; 1167 1168 rc = mls_convert_context(args->oldp, args->newp, c); 1169 if (rc) 1170 goto bad; 1171 1172 /* Check the validity of the new context. */ 1173 if (!policydb_context_isvalid(args->newp, c)) { 1174 rc = convert_context_handle_invalid_context(&oldc); 1175 if (rc) 1176 goto bad; 1177 } 1178 1179 context_destroy(&oldc); 1180out: 1181 return rc; 1182bad: 1183 context_struct_to_string(&oldc, &s, &len); 1184 context_destroy(&oldc); 1185 printk(KERN_ERR "security: invalidating context %s\n", s); 1186 kfree(s); 1187 goto out; 1188} 1189 1190extern void selinux_complete_init(void); 1191 1192/** 1193 * security_load_policy - Load a security policy configuration. 1194 * @data: binary policy data 1195 * @len: length of data in bytes 1196 * 1197 * Load a new set of security policy configuration data, 1198 * validate it and convert the SID table as necessary. 1199 * This function will flush the access vector cache after 1200 * loading the new policy. 1201 */ 1202int security_load_policy(void *data, size_t len) 1203{ 1204 struct policydb oldpolicydb, newpolicydb; 1205 struct sidtab oldsidtab, newsidtab; 1206 struct convert_context_args args; 1207 u32 seqno; 1208 int rc = 0; 1209 struct policy_file file = { data, len }, *fp = &file; 1210 1211 LOAD_LOCK; 1212 1213 if (!ss_initialized) { 1214 avtab_cache_init(); 1215 if (policydb_read(&policydb, fp)) { 1216 LOAD_UNLOCK; 1217 avtab_cache_destroy(); 1218 return -EINVAL; 1219 } 1220 if (policydb_load_isids(&policydb, &sidtab)) { 1221 LOAD_UNLOCK; 1222 policydb_destroy(&policydb); 1223 avtab_cache_destroy(); 1224 return -EINVAL; 1225 } 1226 policydb_loaded_version = policydb.policyvers; 1227 ss_initialized = 1; 1228 seqno = ++latest_granting; 1229 LOAD_UNLOCK; 1230 selinux_complete_init(); 1231 avc_ss_reset(seqno); 1232 selnl_notify_policyload(seqno); 1233 return 0; 1234 } 1235 1236#if 0 1237 sidtab_hash_eval(&sidtab, "sids"); 1238#endif 1239 1240 if (policydb_read(&newpolicydb, fp)) { 1241 LOAD_UNLOCK; 1242 return -EINVAL; 1243 } 1244 1245 sidtab_init(&newsidtab); 1246 1247 /* Verify that the existing classes did not change. */ 1248 if (hashtab_map(policydb.p_classes.table, validate_class, &newpolicydb)) { 1249 printk(KERN_ERR "security: the definition of an existing " 1250 "class changed\n"); 1251 rc = -EINVAL; 1252 goto err; 1253 } 1254 1255 /* Clone the SID table. */ 1256 sidtab_shutdown(&sidtab); 1257 if (sidtab_map(&sidtab, clone_sid, &newsidtab)) { 1258 rc = -ENOMEM; 1259 goto err; 1260 } 1261 1262 /* Convert the internal representations of contexts 1263 in the new SID table and remove invalid SIDs. */ 1264 args.oldp = &policydb; 1265 args.newp = &newpolicydb; 1266 sidtab_map_remove_on_error(&newsidtab, convert_context, &args); 1267 1268 /* Save the old policydb and SID table to free later. */ 1269 memcpy(&oldpolicydb, &policydb, sizeof policydb); 1270 sidtab_set(&oldsidtab, &sidtab); 1271 1272 /* Install the new policydb and SID table. */ 1273 POLICY_WRLOCK; 1274 memcpy(&policydb, &newpolicydb, sizeof policydb); 1275 sidtab_set(&sidtab, &newsidtab); 1276 seqno = ++latest_granting; 1277 policydb_loaded_version = policydb.policyvers; 1278 POLICY_WRUNLOCK; 1279 LOAD_UNLOCK; 1280 1281 /* Free the old policydb and SID table. */ 1282 policydb_destroy(&oldpolicydb); 1283 sidtab_destroy(&oldsidtab); 1284 1285 avc_ss_reset(seqno); 1286 selnl_notify_policyload(seqno); 1287 1288 return 0; 1289 1290err: 1291 LOAD_UNLOCK; 1292 sidtab_destroy(&newsidtab); 1293 policydb_destroy(&newpolicydb); 1294 return rc; 1295 1296} 1297 1298/** 1299 * security_port_sid - Obtain the SID for a port. 1300 * @domain: communication domain aka address family 1301 * @type: socket type 1302 * @protocol: protocol number 1303 * @port: port number 1304 * @out_sid: security identifier 1305 */ 1306int security_port_sid(u16 domain, 1307 u16 type, 1308 u8 protocol, 1309 u16 port, 1310 u32 *out_sid) 1311{ 1312 struct ocontext *c; 1313 int rc = 0; 1314 1315 POLICY_RDLOCK; 1316 1317 c = policydb.ocontexts[OCON_PORT]; 1318 while (c) { 1319 if (c->u.port.protocol == protocol && 1320 c->u.port.low_port <= port && 1321 c->u.port.high_port >= port) 1322 break; 1323 c = c->next; 1324 } 1325 1326 if (c) { 1327 if (!c->sid[0]) { 1328 rc = sidtab_context_to_sid(&sidtab, 1329 &c->context[0], 1330 &c->sid[0]); 1331 if (rc) 1332 goto out; 1333 } 1334 *out_sid = c->sid[0]; 1335 } else { 1336 *out_sid = SECINITSID_PORT; 1337 } 1338 1339out: 1340 POLICY_RDUNLOCK; 1341 return rc; 1342} 1343 1344/** 1345 * security_netif_sid - Obtain the SID for a network interface. 1346 * @name: interface name 1347 * @if_sid: interface SID 1348 * @msg_sid: default SID for received packets 1349 */ 1350int security_netif_sid(char *name, 1351 u32 *if_sid, 1352 u32 *msg_sid) 1353{ 1354 int rc = 0; 1355 struct ocontext *c; 1356 1357 POLICY_RDLOCK; 1358 1359 c = policydb.ocontexts[OCON_NETIF]; 1360 while (c) { 1361 if (strcmp(name, c->u.name) == 0) 1362 break; 1363 c = c->next; 1364 } 1365 1366 if (c) { 1367 if (!c->sid[0] || !c->sid[1]) { 1368 rc = sidtab_context_to_sid(&sidtab, 1369 &c->context[0], 1370 &c->sid[0]); 1371 if (rc) 1372 goto out; 1373 rc = sidtab_context_to_sid(&sidtab, 1374 &c->context[1], 1375 &c->sid[1]); 1376 if (rc) 1377 goto out; 1378 } 1379 *if_sid = c->sid[0]; 1380 *msg_sid = c->sid[1]; 1381 } else { 1382 *if_sid = SECINITSID_NETIF; 1383 *msg_sid = SECINITSID_NETMSG; 1384 } 1385 1386out: 1387 POLICY_RDUNLOCK; 1388 return rc; 1389} 1390 1391static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) 1392{ 1393 int i, fail = 0; 1394 1395 for(i = 0; i < 4; i++) 1396 if(addr[i] != (input[i] & mask[i])) { 1397 fail = 1; 1398 break; 1399 } 1400 1401 return !fail; 1402} 1403 1404/** 1405 * security_node_sid - Obtain the SID for a node (host). 1406 * @domain: communication domain aka address family 1407 * @addrp: address 1408 * @addrlen: address length in bytes 1409 * @out_sid: security identifier 1410 */ 1411int security_node_sid(u16 domain, 1412 void *addrp, 1413 u32 addrlen, 1414 u32 *out_sid) 1415{ 1416 int rc = 0; 1417 struct ocontext *c; 1418 1419 POLICY_RDLOCK; 1420 1421 switch (domain) { 1422 case AF_INET: { 1423 u32 addr; 1424 1425 if (addrlen != sizeof(u32)) { 1426 rc = -EINVAL; 1427 goto out; 1428 } 1429 1430 addr = *((u32 *)addrp); 1431 1432 c = policydb.ocontexts[OCON_NODE]; 1433 while (c) { 1434 if (c->u.node.addr == (addr & c->u.node.mask)) 1435 break; 1436 c = c->next; 1437 } 1438 break; 1439 } 1440 1441 case AF_INET6: 1442 if (addrlen != sizeof(u64) * 2) { 1443 rc = -EINVAL; 1444 goto out; 1445 } 1446 c = policydb.ocontexts[OCON_NODE6]; 1447 while (c) { 1448 if (match_ipv6_addrmask(addrp, c->u.node6.addr, 1449 c->u.node6.mask)) 1450 break; 1451 c = c->next; 1452 } 1453 break; 1454 1455 default: 1456 *out_sid = SECINITSID_NODE; 1457 goto out; 1458 } 1459 1460 if (c) { 1461 if (!c->sid[0]) { 1462 rc = sidtab_context_to_sid(&sidtab, 1463 &c->context[0], 1464 &c->sid[0]); 1465 if (rc) 1466 goto out; 1467 } 1468 *out_sid = c->sid[0]; 1469 } else { 1470 *out_sid = SECINITSID_NODE; 1471 } 1472 1473out: 1474 POLICY_RDUNLOCK; 1475 return rc; 1476} 1477 1478#define SIDS_NEL 25 1479 1480/** 1481 * security_get_user_sids - Obtain reachable SIDs for a user. 1482 * @fromsid: starting SID 1483 * @username: username 1484 * @sids: array of reachable SIDs for user 1485 * @nel: number of elements in @sids 1486 * 1487 * Generate the set of SIDs for legal security contexts 1488 * for a given user that can be reached by @fromsid. 1489 * Set *@sids to point to a dynamically allocated 1490 * array containing the set of SIDs. Set *@nel to the 1491 * number of elements in the array. 1492 */ 1493 1494int security_get_user_sids(u32 fromsid, 1495 char *username, 1496 u32 **sids, 1497 u32 *nel) 1498{ 1499 struct context *fromcon, usercon; 1500 u32 *mysids, *mysids2, sid; 1501 u32 mynel = 0, maxnel = SIDS_NEL; 1502 struct user_datum *user; 1503 struct role_datum *role; 1504 struct av_decision avd; 1505 int rc = 0, i, j; 1506 1507 if (!ss_initialized) { 1508 *sids = NULL; 1509 *nel = 0; 1510 goto out; 1511 } 1512 1513 POLICY_RDLOCK; 1514 1515 fromcon = sidtab_search(&sidtab, fromsid); 1516 if (!fromcon) { 1517 rc = -EINVAL; 1518 goto out_unlock; 1519 } 1520 1521 user = hashtab_search(policydb.p_users.table, username); 1522 if (!user) { 1523 rc = -EINVAL; 1524 goto out_unlock; 1525 } 1526 usercon.user = user->value; 1527 1528 mysids = kmalloc(maxnel*sizeof(*mysids), GFP_ATOMIC); 1529 if (!mysids) { 1530 rc = -ENOMEM; 1531 goto out_unlock; 1532 } 1533 memset(mysids, 0, maxnel*sizeof(*mysids)); 1534 1535 for (i = ebitmap_startbit(&user->roles); i < ebitmap_length(&user->roles); i++) { 1536 if (!ebitmap_get_bit(&user->roles, i)) 1537 continue; 1538 role = policydb.role_val_to_struct[i]; 1539 usercon.role = i+1; 1540 for (j = ebitmap_startbit(&role->types); j < ebitmap_length(&role->types); j++) { 1541 if (!ebitmap_get_bit(&role->types, j)) 1542 continue; 1543 usercon.type = j+1; 1544 1545 if (mls_setup_user_range(fromcon, user, &usercon)) 1546 continue; 1547 1548 rc = context_struct_compute_av(fromcon, &usercon, 1549 SECCLASS_PROCESS, 1550 PROCESS__TRANSITION, 1551 &avd); 1552 if (rc || !(avd.allowed & PROCESS__TRANSITION)) 1553 continue; 1554 rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); 1555 if (rc) { 1556 kfree(mysids); 1557 goto out_unlock; 1558 } 1559 if (mynel < maxnel) { 1560 mysids[mynel++] = sid; 1561 } else { 1562 maxnel += SIDS_NEL; 1563 mysids2 = kmalloc(maxnel*sizeof(*mysids2), GFP_ATOMIC); 1564 if (!mysids2) { 1565 rc = -ENOMEM; 1566 kfree(mysids); 1567 goto out_unlock; 1568 } 1569 memset(mysids2, 0, maxnel*sizeof(*mysids2)); 1570 memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); 1571 kfree(mysids); 1572 mysids = mysids2; 1573 mysids[mynel++] = sid; 1574 } 1575 } 1576 } 1577 1578 *sids = mysids; 1579 *nel = mynel; 1580 1581out_unlock: 1582 POLICY_RDUNLOCK; 1583out: 1584 return rc; 1585} 1586 1587/** 1588 * security_genfs_sid - Obtain a SID for a file in a filesystem 1589 * @fstype: filesystem type 1590 * @path: path from root of mount 1591 * @sclass: file security class 1592 * @sid: SID for path 1593 * 1594 * Obtain a SID to use for a file in a filesystem that 1595 * cannot support xattr or use a fixed labeling behavior like 1596 * transition SIDs or task SIDs. 1597 */ 1598int security_genfs_sid(const char *fstype, 1599 char *path, 1600 u16 sclass, 1601 u32 *sid) 1602{ 1603 int len; 1604 struct genfs *genfs; 1605 struct ocontext *c; 1606 int rc = 0, cmp = 0; 1607 1608 POLICY_RDLOCK; 1609 1610 for (genfs = policydb.genfs; genfs; genfs = genfs->next) { 1611 cmp = strcmp(fstype, genfs->fstype); 1612 if (cmp <= 0) 1613 break; 1614 } 1615 1616 if (!genfs || cmp) { 1617 *sid = SECINITSID_UNLABELED; 1618 rc = -ENOENT; 1619 goto out; 1620 } 1621 1622 for (c = genfs->head; c; c = c->next) { 1623 len = strlen(c->u.name); 1624 if ((!c->v.sclass || sclass == c->v.sclass) && 1625 (strncmp(c->u.name, path, len) == 0)) 1626 break; 1627 } 1628 1629 if (!c) { 1630 *sid = SECINITSID_UNLABELED; 1631 rc = -ENOENT; 1632 goto out; 1633 } 1634 1635 if (!c->sid[0]) { 1636 rc = sidtab_context_to_sid(&sidtab, 1637 &c->context[0], 1638 &c->sid[0]); 1639 if (rc) 1640 goto out; 1641 } 1642 1643 *sid = c->sid[0]; 1644out: 1645 POLICY_RDUNLOCK; 1646 return rc; 1647} 1648 1649/** 1650 * security_fs_use - Determine how to handle labeling for a filesystem. 1651 * @fstype: filesystem type 1652 * @behavior: labeling behavior 1653 * @sid: SID for filesystem (superblock) 1654 */ 1655int security_fs_use( 1656 const char *fstype, 1657 unsigned int *behavior, 1658 u32 *sid) 1659{ 1660 int rc = 0; 1661 struct ocontext *c; 1662 1663 POLICY_RDLOCK; 1664 1665 c = policydb.ocontexts[OCON_FSUSE]; 1666 while (c) { 1667 if (strcmp(fstype, c->u.name) == 0) 1668 break; 1669 c = c->next; 1670 } 1671 1672 if (c) { 1673 *behavior = c->v.behavior; 1674 if (!c->sid[0]) { 1675 rc = sidtab_context_to_sid(&sidtab, 1676 &c->context[0], 1677 &c->sid[0]); 1678 if (rc) 1679 goto out; 1680 } 1681 *sid = c->sid[0]; 1682 } else { 1683 rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid); 1684 if (rc) { 1685 *behavior = SECURITY_FS_USE_NONE; 1686 rc = 0; 1687 } else { 1688 *behavior = SECURITY_FS_USE_GENFS; 1689 } 1690 } 1691 1692out: 1693 POLICY_RDUNLOCK; 1694 return rc; 1695} 1696 1697int security_get_bools(int *len, char ***names, int **values) 1698{ 1699 int i, rc = -ENOMEM; 1700 1701 POLICY_RDLOCK; 1702 *names = NULL; 1703 *values = NULL; 1704 1705 *len = policydb.p_bools.nprim; 1706 if (!*len) { 1707 rc = 0; 1708 goto out; 1709 } 1710 1711 *names = (char**)kmalloc(sizeof(char*) * *len, GFP_ATOMIC); 1712 if (!*names) 1713 goto err; 1714 memset(*names, 0, sizeof(char*) * *len); 1715 1716 *values = (int*)kmalloc(sizeof(int) * *len, GFP_ATOMIC); 1717 if (!*values) 1718 goto err; 1719 1720 for (i = 0; i < *len; i++) { 1721 size_t name_len; 1722 (*values)[i] = policydb.bool_val_to_struct[i]->state; 1723 name_len = strlen(policydb.p_bool_val_to_name[i]) + 1; 1724 (*names)[i] = (char*)kmalloc(sizeof(char) * name_len, GFP_ATOMIC); 1725 if (!(*names)[i]) 1726 goto err; 1727 strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len); 1728 (*names)[i][name_len - 1] = 0; 1729 } 1730 rc = 0; 1731out: 1732 POLICY_RDUNLOCK; 1733 return rc; 1734err: 1735 if (*names) { 1736 for (i = 0; i < *len; i++) 1737 kfree((*names)[i]); 1738 } 1739 kfree(*values); 1740 goto out; 1741} 1742 1743 1744int security_set_bools(int len, int *values) 1745{ 1746 int i, rc = 0; 1747 int lenp, seqno = 0; 1748 struct cond_node *cur; 1749 1750 POLICY_WRLOCK; 1751 1752 lenp = policydb.p_bools.nprim; 1753 if (len != lenp) { 1754 rc = -EFAULT; 1755 goto out; 1756 } 1757 1758 printk(KERN_INFO "security: committed booleans { "); 1759 for (i = 0; i < len; i++) { 1760 if (values[i]) { 1761 policydb.bool_val_to_struct[i]->state = 1; 1762 } else { 1763 policydb.bool_val_to_struct[i]->state = 0; 1764 } 1765 if (i != 0) 1766 printk(", "); 1767 printk("%s:%d", policydb.p_bool_val_to_name[i], 1768 policydb.bool_val_to_struct[i]->state); 1769 } 1770 printk(" }\n"); 1771 1772 for (cur = policydb.cond_list; cur != NULL; cur = cur->next) { 1773 rc = evaluate_cond_node(&policydb, cur); 1774 if (rc) 1775 goto out; 1776 } 1777 1778 seqno = ++latest_granting; 1779 1780out: 1781 POLICY_WRUNLOCK; 1782 if (!rc) { 1783 avc_ss_reset(seqno); 1784 selnl_notify_policyload(seqno); 1785 } 1786 return rc; 1787} 1788 1789int security_get_bool_value(int bool) 1790{ 1791 int rc = 0; 1792 int len; 1793 1794 POLICY_RDLOCK; 1795 1796 len = policydb.p_bools.nprim; 1797 if (bool >= len) { 1798 rc = -EFAULT; 1799 goto out; 1800 } 1801 1802 rc = policydb.bool_val_to_struct[bool]->state; 1803out: 1804 POLICY_RDUNLOCK; 1805 return rc; 1806}