security/selinux/ss/services.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Implementation of the security services.
   4  *
   5  * Authors : Stephen Smalley, <sds@tycho.nsa.gov>
   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
  71 struct selinux_policy_convert_data {
  72         struct convert_context_args args;
  73         struct sidtab_convert_params sidtab_params;
  74 };
  75
  76 /* Forward declaration. */
  77 static int context_struct_to_string(struct policydb *policydb,
  78                                     struct context *context,
  79                                     char **scontext,
  80                                     u32 *scontext_len);
  81
  82 static 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
  88 static 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
  95 static 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         unsigned k;
 101         bool print_unknown_handle = false;
 102
 103         /* Find number of classes in the input mapping */
 104         if (!map)
 105                 return -EINVAL;
 106         i = 0;
 107         while (map[i].name)
 108                 i++;
 109
 110         /* Allocate space for the class records, plus one for class zero */
 111         out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
 112         if (!out_map->mapping)
 113                 return -ENOMEM;
 114
 115         /* Store the raw class and permission values */
 116         j = 0;
 117         while (map[j].name) {
 118                 const struct security_class_mapping *p_in = map + (j++);
 119                 struct selinux_mapping *p_out = out_map->mapping + j;
 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;
 166 err:
 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
 176 static 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  */
 187 static 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
 199 static 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 |= 1<<i;
 211                         if (allow_unknown && !mapping->perms[i])
 212                                 result |= 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 |= 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 |= 1<<i;
 224                         if (!allow_unknown && !mapping->perms[i])
 225                                 result |= 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 |= 1<<i;
 234                 avd->auditdeny = result;
 235         }
 236 }
 237
 238 int security_mls_enabled(struct selinux_state *state)
 239 {
 240         int mls_enabled;
 241         struct selinux_policy *policy;
 242
 243         if (!selinux_initialized(state))
 244                 return 0;
 245
 246         rcu_read_lock();
 247         policy = rcu_dereference(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  */
 264 static 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;
 354 mls_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  */
 443 static 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
 455 static 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);
 522 out:
 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  */
 532 static 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 permssions
 587  */
 588 void 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  */
 611 static 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
 716 static int security_validtrans_handle_fail(struct selinux_state *state,
 717                                         struct selinux_policy *policy,
 718                                         struct sidtab_entry *oentry,
 719                                         struct sidtab_entry *nentry,
 720                                         struct sidtab_entry *tentry,
 721                                         u16 tclass)
 722 {
 723         struct policydb *p = &policy->policydb;
 724         struct sidtab *sidtab = policy->sidtab;
 725         char *o = NULL, *n = NULL, *t = NULL;
 726         u32 olen, nlen, tlen;
 727
 728         if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
 729                 goto out;
 730         if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
 731                 goto out;
 732         if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
 733                 goto out;
 734         audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
 735                   "op=security_validate_transition seresult=denied"
 736                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 737                   o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
 738 out:
 739         kfree(o);
 740         kfree(n);
 741         kfree(t);
 742
 743         if (!enforcing_enabled(state))
 744                 return 0;
 745         return -EPERM;
 746 }
 747
 748 static int security_compute_validatetrans(struct selinux_state *state,
 749                                           u32 oldsid, u32 newsid, u32 tasksid,
 750                                           u16 orig_tclass, bool user)
 751 {
 752         struct selinux_policy *policy;
 753         struct policydb *policydb;
 754         struct sidtab *sidtab;
 755         struct sidtab_entry *oentry;
 756         struct sidtab_entry *nentry;
 757         struct sidtab_entry *tentry;
 758         struct class_datum *tclass_datum;
 759         struct constraint_node *constraint;
 760         u16 tclass;
 761         int rc = 0;
 762
 763
 764         if (!selinux_initialized(state))
 765                 return 0;
 766
 767         rcu_read_lock();
 768
 769         policy = rcu_dereference(state->policy);
 770         policydb = &policy->policydb;
 771         sidtab = policy->sidtab;
 772
 773         if (!user)
 774                 tclass = unmap_class(&policy->map, orig_tclass);
 775         else
 776                 tclass = orig_tclass;
 777
 778         if (!tclass || tclass > policydb->p_classes.nprim) {
 779                 rc = -EINVAL;
 780                 goto out;
 781         }
 782         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 783
 784         oentry = sidtab_search_entry(sidtab, oldsid);
 785         if (!oentry) {
 786                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 787                         __func__, oldsid);
 788                 rc = -EINVAL;
 789                 goto out;
 790         }
 791
 792         nentry = sidtab_search_entry(sidtab, newsid);
 793         if (!nentry) {
 794                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 795                         __func__, newsid);
 796                 rc = -EINVAL;
 797                 goto out;
 798         }
 799
 800         tentry = sidtab_search_entry(sidtab, tasksid);
 801         if (!tentry) {
 802                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 803                         __func__, tasksid);
 804                 rc = -EINVAL;
 805                 goto out;
 806         }
 807
 808         constraint = tclass_datum->validatetrans;
 809         while (constraint) {
 810                 if (!constraint_expr_eval(policydb, &oentry->context,
 811                                           &nentry->context, &tentry->context,
 812                                           constraint->expr)) {
 813                         if (user)
 814                                 rc = -EPERM;
 815                         else
 816                                 rc = security_validtrans_handle_fail(state,
 817                                                                 policy,
 818                                                                 oentry,
 819                                                                 nentry,
 820                                                                 tentry,
 821                                                                 tclass);
 822                         goto out;
 823                 }
 824                 constraint = constraint->next;
 825         }
 826
 827 out:
 828         rcu_read_unlock();
 829         return rc;
 830 }
 831
 832 int security_validate_transition_user(struct selinux_state *state,
 833                                       u32 oldsid, u32 newsid, u32 tasksid,
 834                                       u16 tclass)
 835 {
 836         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 837                                               tclass, true);
 838 }
 839
 840 int security_validate_transition(struct selinux_state *state,
 841                                  u32 oldsid, u32 newsid, u32 tasksid,
 842                                  u16 orig_tclass)
 843 {
 844         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 845                                               orig_tclass, false);
 846 }
 847
 848 /*
 849  * security_bounded_transition - check whether the given
 850  * transition is directed to bounded, or not.
 851  * It returns 0, if @newsid is bounded by @oldsid.
 852  * Otherwise, it returns error code.
 853  *
 854  * @state: SELinux state
 855  * @oldsid : current security identifier
 856  * @newsid : destinated security identifier
 857  */
 858 int security_bounded_transition(struct selinux_state *state,
 859                                 u32 old_sid, u32 new_sid)
 860 {
 861         struct selinux_policy *policy;
 862         struct policydb *policydb;
 863         struct sidtab *sidtab;
 864         struct sidtab_entry *old_entry, *new_entry;
 865         struct type_datum *type;
 866         int index;
 867         int rc;
 868
 869         if (!selinux_initialized(state))
 870                 return 0;
 871
 872         rcu_read_lock();
 873         policy = rcu_dereference(state->policy);
 874         policydb = &policy->policydb;
 875         sidtab = policy->sidtab;
 876
 877         rc = -EINVAL;
 878         old_entry = sidtab_search_entry(sidtab, old_sid);
 879         if (!old_entry) {
 880                 pr_err("SELinux: %s: unrecognized SID %u\n",
 881                        __func__, old_sid);
 882                 goto out;
 883         }
 884
 885         rc = -EINVAL;
 886         new_entry = sidtab_search_entry(sidtab, new_sid);
 887         if (!new_entry) {
 888                 pr_err("SELinux: %s: unrecognized SID %u\n",
 889                        __func__, new_sid);
 890                 goto out;
 891         }
 892
 893         rc = 0;
 894         /* type/domain unchanged */
 895         if (old_entry->context.type == new_entry->context.type)
 896                 goto out;
 897
 898         index = new_entry->context.type;
 899         while (true) {
 900                 type = policydb->type_val_to_struct[index - 1];
 901                 BUG_ON(!type);
 902
 903                 /* not bounded anymore */
 904                 rc = -EPERM;
 905                 if (!type->bounds)
 906                         break;
 907
 908                 /* @newsid is bounded by @oldsid */
 909                 rc = 0;
 910                 if (type->bounds == old_entry->context.type)
 911                         break;
 912
 913                 index = type->bounds;
 914         }
 915
 916         if (rc) {
 917                 char *old_name = NULL;
 918                 char *new_name = NULL;
 919                 u32 length;
 920
 921                 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
 922                                             &old_name, &length) &&
 923                     !sidtab_entry_to_string(policydb, sidtab, new_entry,
 924                                             &new_name, &length)) {
 925                         audit_log(audit_context(),
 926                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 927                                   "op=security_bounded_transition "
 928                                   "seresult=denied "
 929                                   "oldcontext=%s newcontext=%s",
 930                                   old_name, new_name);
 931                 }
 932                 kfree(new_name);
 933                 kfree(old_name);
 934         }
 935 out:
 936         rcu_read_unlock();
 937
 938         return rc;
 939 }
 940
 941 static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
 942 {
 943         avd->allowed = 0;
 944         avd->auditallow = 0;
 945         avd->auditdeny = 0xffffffff;
 946         if (policy)
 947                 avd->seqno = policy->latest_granting;
 948         else
 949                 avd->seqno = 0;
 950         avd->flags = 0;
 951 }
 952
 953 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 954                                         struct avtab_node *node)
 955 {
 956         unsigned int i;
 957
 958         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 959                 if (xpermd->driver != node->datum.u.xperms->driver)
 960                         return;
 961         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 962                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 963                                         xpermd->driver))
 964                         return;
 965         } else {
 966                 BUG();
 967         }
 968
 969         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 970                 xpermd->used |= XPERMS_ALLOWED;
 971                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 972                         memset(xpermd->allowed->p, 0xff,
 973                                         sizeof(xpermd->allowed->p));
 974                 }
 975                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 976                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 977                                 xpermd->allowed->p[i] |=
 978                                         node->datum.u.xperms->perms.p[i];
 979                 }
 980         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 981                 xpermd->used |= XPERMS_AUDITALLOW;
 982                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 983                         memset(xpermd->auditallow->p, 0xff,
 984                                         sizeof(xpermd->auditallow->p));
 985                 }
 986                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 987                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 988                                 xpermd->auditallow->p[i] |=
 989                                         node->datum.u.xperms->perms.p[i];
 990                 }
 991         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 992                 xpermd->used |= XPERMS_DONTAUDIT;
 993                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 994                         memset(xpermd->dontaudit->p, 0xff,
 995                                         sizeof(xpermd->dontaudit->p));
 996                 }
 997                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 998                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
 999                                 xpermd->dontaudit->p[i] |=
1000                                         node->datum.u.xperms->perms.p[i];
1001                 }
1002         } else {
1003                 BUG();
1004         }
1005 }
1006
1007 void security_compute_xperms_decision(struct selinux_state *state,
1008                                       u32 ssid,
1009                                       u32 tsid,
1010                                       u16 orig_tclass,
1011                                       u8 driver,
1012                                       struct extended_perms_decision *xpermd)
1013 {
1014         struct selinux_policy *policy;
1015         struct policydb *policydb;
1016         struct sidtab *sidtab;
1017         u16 tclass;
1018         struct context *scontext, *tcontext;
1019         struct avtab_key avkey;
1020         struct avtab_node *node;
1021         struct ebitmap *sattr, *tattr;
1022         struct ebitmap_node *snode, *tnode;
1023         unsigned int i, j;
1024
1025         xpermd->driver = driver;
1026         xpermd->used = 0;
1027         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1028         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1029         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1030
1031         rcu_read_lock();
1032         if (!selinux_initialized(state))
1033                 goto allow;
1034
1035         policy = rcu_dereference(state->policy);
1036         policydb = &policy->policydb;
1037         sidtab = policy->sidtab;
1038
1039         scontext = sidtab_search(sidtab, ssid);
1040         if (!scontext) {
1041                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1042                        __func__, ssid);
1043                 goto out;
1044         }
1045
1046         tcontext = sidtab_search(sidtab, tsid);
1047         if (!tcontext) {
1048                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1049                        __func__, tsid);
1050                 goto out;
1051         }
1052
1053         tclass = unmap_class(&policy->map, orig_tclass);
1054         if (unlikely(orig_tclass && !tclass)) {
1055                 if (policydb->allow_unknown)
1056                         goto allow;
1057                 goto out;
1058         }
1059
1060
1061         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1062                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1063                 goto out;
1064         }
1065
1066         avkey.target_class = tclass;
1067         avkey.specified = AVTAB_XPERMS;
1068         sattr = &policydb->type_attr_map_array[scontext->type - 1];
1069         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1070         ebitmap_for_each_positive_bit(sattr, snode, i) {
1071                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1072                         avkey.source_type = i + 1;
1073                         avkey.target_type = j + 1;
1074                         for (node = avtab_search_node(&policydb->te_avtab,
1075                                                       &avkey);
1076                              node;
1077                              node = avtab_search_node_next(node, avkey.specified))
1078                                 services_compute_xperms_decision(xpermd, node);
1079
1080                         cond_compute_xperms(&policydb->te_cond_avtab,
1081                                                 &avkey, xpermd);
1082                 }
1083         }
1084 out:
1085         rcu_read_unlock();
1086         return;
1087 allow:
1088         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1089         goto out;
1090 }
1091
1092 /**
1093  * security_compute_av - Compute access vector decisions.
1094  * @state: SELinux state
1095  * @ssid: source security identifier
1096  * @tsid: target security identifier
1097  * @orig_tclass: target security class
1098  * @avd: access vector decisions
1099  * @xperms: extended permissions
1100  *
1101  * Compute a set of access vector decisions based on the
1102  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1103  */
1104 void security_compute_av(struct selinux_state *state,
1105                          u32 ssid,
1106                          u32 tsid,
1107                          u16 orig_tclass,
1108                          struct av_decision *avd,
1109                          struct extended_perms *xperms)
1110 {
1111         struct selinux_policy *policy;
1112         struct policydb *policydb;
1113         struct sidtab *sidtab;
1114         u16 tclass;
1115         struct context *scontext = NULL, *tcontext = NULL;
1116
1117         rcu_read_lock();
1118         policy = rcu_dereference(state->policy);
1119         avd_init(policy, avd);
1120         xperms->len = 0;
1121         if (!selinux_initialized(state))
1122                 goto allow;
1123
1124         policydb = &policy->policydb;
1125         sidtab = policy->sidtab;
1126
1127         scontext = sidtab_search(sidtab, ssid);
1128         if (!scontext) {
1129                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1130                        __func__, ssid);
1131                 goto out;
1132         }
1133
1134         /* permissive domain? */
1135         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1136                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1137
1138         tcontext = sidtab_search(sidtab, tsid);
1139         if (!tcontext) {
1140                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1141                        __func__, tsid);
1142                 goto out;
1143         }
1144
1145         tclass = unmap_class(&policy->map, orig_tclass);
1146         if (unlikely(orig_tclass && !tclass)) {
1147                 if (policydb->allow_unknown)
1148                         goto allow;
1149                 goto out;
1150         }
1151         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1152                                   xperms);
1153         map_decision(&policy->map, orig_tclass, avd,
1154                      policydb->allow_unknown);
1155 out:
1156         rcu_read_unlock();
1157         return;
1158 allow:
1159         avd->allowed = 0xffffffff;
1160         goto out;
1161 }
1162
1163 void security_compute_av_user(struct selinux_state *state,
1164                               u32 ssid,
1165                               u32 tsid,
1166                               u16 tclass,
1167                               struct av_decision *avd)
1168 {
1169         struct selinux_policy *policy;
1170         struct policydb *policydb;
1171         struct sidtab *sidtab;
1172         struct context *scontext = NULL, *tcontext = NULL;
1173
1174         rcu_read_lock();
1175         policy = rcu_dereference(state->policy);
1176         avd_init(policy, avd);
1177         if (!selinux_initialized(state))
1178                 goto allow;
1179
1180         policydb = &policy->policydb;
1181         sidtab = policy->sidtab;
1182
1183         scontext = sidtab_search(sidtab, ssid);
1184         if (!scontext) {
1185                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1186                        __func__, ssid);
1187                 goto out;
1188         }
1189
1190         /* permissive domain? */
1191         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1192                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1193
1194         tcontext = sidtab_search(sidtab, tsid);
1195         if (!tcontext) {
1196                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1197                        __func__, tsid);
1198                 goto out;
1199         }
1200
1201         if (unlikely(!tclass)) {
1202                 if (policydb->allow_unknown)
1203                         goto allow;
1204                 goto out;
1205         }
1206
1207         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1208                                   NULL);
1209  out:
1210         rcu_read_unlock();
1211         return;
1212 allow:
1213         avd->allowed = 0xffffffff;
1214         goto out;
1215 }
1216
1217 /*
1218  * Write the security context string representation of
1219  * the context structure `context' into a dynamically
1220  * allocated string of the correct size.  Set `*scontext'
1221  * to point to this string and set `*scontext_len' to
1222  * the length of the string.
1223  */
1224 static int context_struct_to_string(struct policydb *p,
1225                                     struct context *context,
1226                                     char **scontext, u32 *scontext_len)
1227 {
1228         char *scontextp;
1229
1230         if (scontext)
1231                 *scontext = NULL;
1232         *scontext_len = 0;
1233
1234         if (context->len) {
1235                 *scontext_len = context->len;
1236                 if (scontext) {
1237                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1238                         if (!(*scontext))
1239                                 return -ENOMEM;
1240                 }
1241                 return 0;
1242         }
1243
1244         /* Compute the size of the context. */
1245         *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1246         *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1247         *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1248         *scontext_len += mls_compute_context_len(p, context);
1249
1250         if (!scontext)
1251                 return 0;
1252
1253         /* Allocate space for the context; caller must free this space. */
1254         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1255         if (!scontextp)
1256                 return -ENOMEM;
1257         *scontext = scontextp;
1258
1259         /*
1260          * Copy the user name, role name and type name into the context.
1261          */
1262         scontextp += sprintf(scontextp, "%s:%s:%s",
1263                 sym_name(p, SYM_USERS, context->user - 1),
1264                 sym_name(p, SYM_ROLES, context->role - 1),
1265                 sym_name(p, SYM_TYPES, context->type - 1));
1266
1267         mls_sid_to_context(p, context, &scontextp);
1268
1269         *scontextp = 0;
1270
1271         return 0;
1272 }
1273
1274 static int sidtab_entry_to_string(struct policydb *p,
1275                                   struct sidtab *sidtab,
1276                                   struct sidtab_entry *entry,
1277                                   char **scontext, u32 *scontext_len)
1278 {
1279         int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1280
1281         if (rc != -ENOENT)
1282                 return rc;
1283
1284         rc = context_struct_to_string(p, &entry->context, scontext,
1285                                       scontext_len);
1286         if (!rc && scontext)
1287                 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1288         return rc;
1289 }
1290
1291 #include "initial_sid_to_string.h"
1292
1293 int security_sidtab_hash_stats(struct selinux_state *state, char *page)
1294 {
1295         struct selinux_policy *policy;
1296         int rc;
1297
1298         if (!selinux_initialized(state)) {
1299                 pr_err("SELinux: %s:  called before initial load_policy\n",
1300                        __func__);
1301                 return -EINVAL;
1302         }
1303
1304         rcu_read_lock();
1305         policy = rcu_dereference(state->policy);
1306         rc = sidtab_hash_stats(policy->sidtab, page);
1307         rcu_read_unlock();
1308
1309         return rc;
1310 }
1311
1312 const char *security_get_initial_sid_context(u32 sid)
1313 {
1314         if (unlikely(sid > SECINITSID_NUM))
1315                 return NULL;
1316         return initial_sid_to_string[sid];
1317 }
1318
1319 static int security_sid_to_context_core(struct selinux_state *state,
1320                                         u32 sid, char **scontext,
1321                                         u32 *scontext_len, int force,
1322                                         int only_invalid)
1323 {
1324         struct selinux_policy *policy;
1325         struct policydb *policydb;
1326         struct sidtab *sidtab;
1327         struct sidtab_entry *entry;
1328         int rc = 0;
1329
1330         if (scontext)
1331                 *scontext = NULL;
1332         *scontext_len  = 0;
1333
1334         if (!selinux_initialized(state)) {
1335                 if (sid <= SECINITSID_NUM) {
1336                         char *scontextp;
1337                         const char *s = initial_sid_to_string[sid];
1338
1339                         if (!s)
1340                                 return -EINVAL;
1341                         *scontext_len = strlen(s) + 1;
1342                         if (!scontext)
1343                                 return 0;
1344                         scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1345                         if (!scontextp)
1346                                 return -ENOMEM;
1347                         *scontext = scontextp;
1348                         return 0;
1349                 }
1350                 pr_err("SELinux: %s:  called before initial "
1351                        "load_policy on unknown SID %d\n", __func__, sid);
1352                 return -EINVAL;
1353         }
1354         rcu_read_lock();
1355         policy = rcu_dereference(state->policy);
1356         policydb = &policy->policydb;
1357         sidtab = policy->sidtab;
1358
1359         if (force)
1360                 entry = sidtab_search_entry_force(sidtab, sid);
1361         else
1362                 entry = sidtab_search_entry(sidtab, sid);
1363         if (!entry) {
1364                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1365                         __func__, sid);
1366                 rc = -EINVAL;
1367                 goto out_unlock;
1368         }
1369         if (only_invalid && !entry->context.len)
1370                 goto out_unlock;
1371
1372         rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1373                                     scontext_len);
1374
1375 out_unlock:
1376         rcu_read_unlock();
1377         return rc;
1378
1379 }
1380
1381 /**
1382  * security_sid_to_context - Obtain a context for a given SID.
1383  * @state: SELinux state
1384  * @sid: security identifier, SID
1385  * @scontext: security context
1386  * @scontext_len: length in bytes
1387  *
1388  * Write the string representation of the context associated with @sid
1389  * into a dynamically allocated string of the correct size.  Set @scontext
1390  * to point to this string and set @scontext_len to the length of the string.
1391  */
1392 int security_sid_to_context(struct selinux_state *state,
1393                             u32 sid, char **scontext, u32 *scontext_len)
1394 {
1395         return security_sid_to_context_core(state, sid, scontext,
1396                                             scontext_len, 0, 0);
1397 }
1398
1399 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1400                                   char **scontext, u32 *scontext_len)
1401 {
1402         return security_sid_to_context_core(state, sid, scontext,
1403                                             scontext_len, 1, 0);
1404 }
1405
1406 /**
1407  * security_sid_to_context_inval - Obtain a context for a given SID if it
1408  *                                 is invalid.
1409  * @state: SELinux state
1410  * @sid: security identifier, SID
1411  * @scontext: security context
1412  * @scontext_len: length in bytes
1413  *
1414  * Write the string representation of the context associated with @sid
1415  * into a dynamically allocated string of the correct size, but only if the
1416  * context is invalid in the current policy.  Set @scontext to point to
1417  * this string (or NULL if the context is valid) and set @scontext_len to
1418  * the length of the string (or 0 if the context is valid).
1419  */
1420 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1421                                   char **scontext, u32 *scontext_len)
1422 {
1423         return security_sid_to_context_core(state, sid, scontext,
1424                                             scontext_len, 1, 1);
1425 }
1426
1427 /*
1428  * Caveat:  Mutates scontext.
1429  */
1430 static int string_to_context_struct(struct policydb *pol,
1431                                     struct sidtab *sidtabp,
1432                                     char *scontext,
1433                                     struct context *ctx,
1434                                     u32 def_sid)
1435 {
1436         struct role_datum *role;
1437         struct type_datum *typdatum;
1438         struct user_datum *usrdatum;
1439         char *scontextp, *p, oldc;
1440         int rc = 0;
1441
1442         context_init(ctx);
1443
1444         /* Parse the security context. */
1445
1446         rc = -EINVAL;
1447         scontextp = scontext;
1448
1449         /* Extract the user. */
1450         p = scontextp;
1451         while (*p && *p != ':')
1452                 p++;
1453
1454         if (*p == 0)
1455                 goto out;
1456
1457         *p++ = 0;
1458
1459         usrdatum = symtab_search(&pol->p_users, scontextp);
1460         if (!usrdatum)
1461                 goto out;
1462
1463         ctx->user = usrdatum->value;
1464
1465         /* Extract role. */
1466         scontextp = p;
1467         while (*p && *p != ':')
1468                 p++;
1469
1470         if (*p == 0)
1471                 goto out;
1472
1473         *p++ = 0;
1474
1475         role = symtab_search(&pol->p_roles, scontextp);
1476         if (!role)
1477                 goto out;
1478         ctx->role = role->value;
1479
1480         /* Extract type. */
1481         scontextp = p;
1482         while (*p && *p != ':')
1483                 p++;
1484         oldc = *p;
1485         *p++ = 0;
1486
1487         typdatum = symtab_search(&pol->p_types, scontextp);
1488         if (!typdatum || typdatum->attribute)
1489                 goto out;
1490
1491         ctx->type = typdatum->value;
1492
1493         rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1494         if (rc)
1495                 goto out;
1496
1497         /* Check the validity of the new context. */
1498         rc = -EINVAL;
1499         if (!policydb_context_isvalid(pol, ctx))
1500                 goto out;
1501         rc = 0;
1502 out:
1503         if (rc)
1504                 context_destroy(ctx);
1505         return rc;
1506 }
1507
1508 static int security_context_to_sid_core(struct selinux_state *state,
1509                                         const char *scontext, u32 scontext_len,
1510                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1511                                         int force)
1512 {
1513         struct selinux_policy *policy;
1514         struct policydb *policydb;
1515         struct sidtab *sidtab;
1516         char *scontext2, *str = NULL;
1517         struct context context;
1518         int rc = 0;
1519
1520         /* An empty security context is never valid. */
1521         if (!scontext_len)
1522                 return -EINVAL;
1523
1524         /* Copy the string to allow changes and ensure a NUL terminator */
1525         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1526         if (!scontext2)
1527                 return -ENOMEM;
1528
1529         if (!selinux_initialized(state)) {
1530                 int i;
1531
1532                 for (i = 1; i < SECINITSID_NUM; i++) {
1533                         const char *s = initial_sid_to_string[i];
1534
1535                         if (s && !strcmp(s, scontext2)) {
1536                                 *sid = i;
1537                                 goto out;
1538                         }
1539                 }
1540                 *sid = SECINITSID_KERNEL;
1541                 goto out;
1542         }
1543         *sid = SECSID_NULL;
1544
1545         if (force) {
1546                 /* Save another copy for storing in uninterpreted form */
1547                 rc = -ENOMEM;
1548                 str = kstrdup(scontext2, gfp_flags);
1549                 if (!str)
1550                         goto out;
1551         }
1552 retry:
1553         rcu_read_lock();
1554         policy = rcu_dereference(state->policy);
1555         policydb = &policy->policydb;
1556         sidtab = policy->sidtab;
1557         rc = string_to_context_struct(policydb, sidtab, scontext2,
1558                                       &context, def_sid);
1559         if (rc == -EINVAL && force) {
1560                 context.str = str;
1561                 context.len = strlen(str) + 1;
1562                 str = NULL;
1563         } else if (rc)
1564                 goto out_unlock;
1565         rc = sidtab_context_to_sid(sidtab, &context, sid);
1566         if (rc == -ESTALE) {
1567                 rcu_read_unlock();
1568                 if (context.str) {
1569                         str = context.str;
1570                         context.str = NULL;
1571                 }
1572                 context_destroy(&context);
1573                 goto retry;
1574         }
1575         context_destroy(&context);
1576 out_unlock:
1577         rcu_read_unlock();
1578 out:
1579         kfree(scontext2);
1580         kfree(str);
1581         return rc;
1582 }
1583
1584 /**
1585  * security_context_to_sid - Obtain a SID for a given security context.
1586  * @state: SELinux state
1587  * @scontext: security context
1588  * @scontext_len: length in bytes
1589  * @sid: security identifier, SID
1590  * @gfp: context for the allocation
1591  *
1592  * Obtains a SID associated with the security context that
1593  * has the string representation specified by @scontext.
1594  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1595  * memory is available, or 0 on success.
1596  */
1597 int security_context_to_sid(struct selinux_state *state,
1598                             const char *scontext, u32 scontext_len, u32 *sid,
1599                             gfp_t gfp)
1600 {
1601         return security_context_to_sid_core(state, scontext, scontext_len,
1602                                             sid, SECSID_NULL, gfp, 0);
1603 }
1604
1605 int security_context_str_to_sid(struct selinux_state *state,
1606                                 const char *scontext, u32 *sid, gfp_t gfp)
1607 {
1608         return security_context_to_sid(state, scontext, strlen(scontext),
1609                                        sid, gfp);
1610 }
1611
1612 /**
1613  * security_context_to_sid_default - Obtain a SID for a given security context,
1614  * falling back to specified default if needed.
1615  *
1616  * @state: SELinux state
1617  * @scontext: security context
1618  * @scontext_len: length in bytes
1619  * @sid: security identifier, SID
1620  * @def_sid: default SID to assign on error
1621  * @gfp_flags: the allocator get-free-page (GFP) flags
1622  *
1623  * Obtains a SID associated with the security context that
1624  * has the string representation specified by @scontext.
1625  * The default SID is passed to the MLS layer to be used to allow
1626  * kernel labeling of the MLS field if the MLS field is not present
1627  * (for upgrading to MLS without full relabel).
1628  * Implicitly forces adding of the context even if it cannot be mapped yet.
1629  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1630  * memory is available, or 0 on success.
1631  */
1632 int security_context_to_sid_default(struct selinux_state *state,
1633                                     const char *scontext, u32 scontext_len,
1634                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1635 {
1636         return security_context_to_sid_core(state, scontext, scontext_len,
1637                                             sid, def_sid, gfp_flags, 1);
1638 }
1639
1640 int security_context_to_sid_force(struct selinux_state *state,
1641                                   const char *scontext, u32 scontext_len,
1642                                   u32 *sid)
1643 {
1644         return security_context_to_sid_core(state, scontext, scontext_len,
1645                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1646 }
1647
1648 static int compute_sid_handle_invalid_context(
1649         struct selinux_state *state,
1650         struct selinux_policy *policy,
1651         struct sidtab_entry *sentry,
1652         struct sidtab_entry *tentry,
1653         u16 tclass,
1654         struct context *newcontext)
1655 {
1656         struct policydb *policydb = &policy->policydb;
1657         struct sidtab *sidtab = policy->sidtab;
1658         char *s = NULL, *t = NULL, *n = NULL;
1659         u32 slen, tlen, nlen;
1660         struct audit_buffer *ab;
1661
1662         if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1663                 goto out;
1664         if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1665                 goto out;
1666         if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1667                 goto out;
1668         ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1669         if (!ab)
1670                 goto out;
1671         audit_log_format(ab,
1672                          "op=security_compute_sid invalid_context=");
1673         /* no need to record the NUL with untrusted strings */
1674         audit_log_n_untrustedstring(ab, n, nlen - 1);
1675         audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1676                          s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1677         audit_log_end(ab);
1678 out:
1679         kfree(s);
1680         kfree(t);
1681         kfree(n);
1682         if (!enforcing_enabled(state))
1683                 return 0;
1684         return -EACCES;
1685 }
1686
1687 static void filename_compute_type(struct policydb *policydb,
1688                                   struct context *newcontext,
1689                                   u32 stype, u32 ttype, u16 tclass,
1690                                   const char *objname)
1691 {
1692         struct filename_trans_key ft;
1693         struct filename_trans_datum *datum;
1694
1695         /*
1696          * Most filename trans rules are going to live in specific directories
1697          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1698          * if the ttype does not contain any rules.
1699          */
1700         if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1701                 return;
1702
1703         ft.ttype = ttype;
1704         ft.tclass = tclass;
1705         ft.name = objname;
1706
1707         datum = policydb_filenametr_search(policydb, &ft);
1708         while (datum) {
1709                 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1710                         newcontext->type = datum->otype;
1711                         return;
1712                 }
1713                 datum = datum->next;
1714         }
1715 }
1716
1717 static int security_compute_sid(struct selinux_state *state,
1718                                 u32 ssid,
1719                                 u32 tsid,
1720                                 u16 orig_tclass,
1721                                 u32 specified,
1722                                 const char *objname,
1723                                 u32 *out_sid,
1724                                 bool kern)
1725 {
1726         struct selinux_policy *policy;
1727         struct policydb *policydb;
1728         struct sidtab *sidtab;
1729         struct class_datum *cladatum;
1730         struct context *scontext, *tcontext, newcontext;
1731         struct sidtab_entry *sentry, *tentry;
1732         struct avtab_key avkey;
1733         struct avtab_datum *avdatum;
1734         struct avtab_node *node;
1735         u16 tclass;
1736         int rc = 0;
1737         bool sock;
1738
1739         if (!selinux_initialized(state)) {
1740                 switch (orig_tclass) {
1741                 case SECCLASS_PROCESS: /* kernel value */
1742                         *out_sid = ssid;
1743                         break;
1744                 default:
1745                         *out_sid = tsid;
1746                         break;
1747                 }
1748                 goto out;
1749         }
1750
1751 retry:
1752         cladatum = NULL;
1753         context_init(&newcontext);
1754
1755         rcu_read_lock();
1756
1757         policy = rcu_dereference(state->policy);
1758
1759         if (kern) {
1760                 tclass = unmap_class(&policy->map, orig_tclass);
1761                 sock = security_is_socket_class(orig_tclass);
1762         } else {
1763                 tclass = orig_tclass;
1764                 sock = security_is_socket_class(map_class(&policy->map,
1765                                                           tclass));
1766         }
1767
1768         policydb = &policy->policydb;
1769         sidtab = policy->sidtab;
1770
1771         sentry = sidtab_search_entry(sidtab, ssid);
1772         if (!sentry) {
1773                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1774                        __func__, ssid);
1775                 rc = -EINVAL;
1776                 goto out_unlock;
1777         }
1778         tentry = sidtab_search_entry(sidtab, tsid);
1779         if (!tentry) {
1780                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1781                        __func__, tsid);
1782                 rc = -EINVAL;
1783                 goto out_unlock;
1784         }
1785
1786         scontext = &sentry->context;
1787         tcontext = &tentry->context;
1788
1789         if (tclass && tclass <= policydb->p_classes.nprim)
1790                 cladatum = policydb->class_val_to_struct[tclass - 1];
1791
1792         /* Set the user identity. */
1793         switch (specified) {
1794         case AVTAB_TRANSITION:
1795         case AVTAB_CHANGE:
1796                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1797                         newcontext.user = tcontext->user;
1798                 } else {
1799                         /* notice this gets both DEFAULT_SOURCE and unset */
1800                         /* Use the process user identity. */
1801                         newcontext.user = scontext->user;
1802                 }
1803                 break;
1804         case AVTAB_MEMBER:
1805                 /* Use the related object owner. */
1806                 newcontext.user = tcontext->user;
1807                 break;
1808         }
1809
1810         /* Set the role to default values. */
1811         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1812                 newcontext.role = scontext->role;
1813         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1814                 newcontext.role = tcontext->role;
1815         } else {
1816                 if ((tclass == policydb->process_class) || sock)
1817                         newcontext.role = scontext->role;
1818                 else
1819                         newcontext.role = OBJECT_R_VAL;
1820         }
1821
1822         /* Set the type to default values. */
1823         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1824                 newcontext.type = scontext->type;
1825         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1826                 newcontext.type = tcontext->type;
1827         } else {
1828                 if ((tclass == policydb->process_class) || sock) {
1829                         /* Use the type of process. */
1830                         newcontext.type = scontext->type;
1831                 } else {
1832                         /* Use the type of the related object. */
1833                         newcontext.type = tcontext->type;
1834                 }
1835         }
1836
1837         /* Look for a type transition/member/change rule. */
1838         avkey.source_type = scontext->type;
1839         avkey.target_type = tcontext->type;
1840         avkey.target_class = tclass;
1841         avkey.specified = specified;
1842         avdatum = avtab_search(&policydb->te_avtab, &avkey);
1843
1844         /* If no permanent rule, also check for enabled conditional rules */
1845         if (!avdatum) {
1846                 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1847                 for (; node; node = avtab_search_node_next(node, specified)) {
1848                         if (node->key.specified & AVTAB_ENABLED) {
1849                                 avdatum = &node->datum;
1850                                 break;
1851                         }
1852                 }
1853         }
1854
1855         if (avdatum) {
1856                 /* Use the type from the type transition/member/change rule. */
1857                 newcontext.type = avdatum->u.data;
1858         }
1859
1860         /* if we have a objname this is a file trans check so check those rules */
1861         if (objname)
1862                 filename_compute_type(policydb, &newcontext, scontext->type,
1863                                       tcontext->type, tclass, objname);
1864
1865         /* Check for class-specific changes. */
1866         if (specified & AVTAB_TRANSITION) {
1867                 /* Look for a role transition rule. */
1868                 struct role_trans_datum *rtd;
1869                 struct role_trans_key rtk = {
1870                         .role = scontext->role,
1871                         .type = tcontext->type,
1872                         .tclass = tclass,
1873                 };
1874
1875                 rtd = policydb_roletr_search(policydb, &rtk);
1876                 if (rtd)
1877                         newcontext.role = rtd->new_role;
1878         }
1879
1880         /* Set the MLS attributes.
1881            This is done last because it may allocate memory. */
1882         rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1883                              &newcontext, sock);
1884         if (rc)
1885                 goto out_unlock;
1886
1887         /* Check the validity of the context. */
1888         if (!policydb_context_isvalid(policydb, &newcontext)) {
1889                 rc = compute_sid_handle_invalid_context(state, policy, sentry,
1890                                                         tentry, tclass,
1891                                                         &newcontext);
1892                 if (rc)
1893                         goto out_unlock;
1894         }
1895         /* Obtain the sid for the context. */
1896         rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1897         if (rc == -ESTALE) {
1898                 rcu_read_unlock();
1899                 context_destroy(&newcontext);
1900                 goto retry;
1901         }
1902 out_unlock:
1903         rcu_read_unlock();
1904         context_destroy(&newcontext);
1905 out:
1906         return rc;
1907 }
1908
1909 /**
1910  * security_transition_sid - Compute the SID for a new subject/object.
1911  * @state: SELinux state
1912  * @ssid: source security identifier
1913  * @tsid: target security identifier
1914  * @tclass: target security class
1915  * @qstr: object name
1916  * @out_sid: security identifier for new subject/object
1917  *
1918  * Compute a SID to use for labeling a new subject or object in the
1919  * class @tclass based on a SID pair (@ssid, @tsid).
1920  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1921  * if insufficient memory is available, or %0 if the new SID was
1922  * computed successfully.
1923  */
1924 int security_transition_sid(struct selinux_state *state,
1925                             u32 ssid, u32 tsid, u16 tclass,
1926                             const struct qstr *qstr, u32 *out_sid)
1927 {
1928         return security_compute_sid(state, ssid, tsid, tclass,
1929                                     AVTAB_TRANSITION,
1930                                     qstr ? qstr->name : NULL, out_sid, true);
1931 }
1932
1933 int security_transition_sid_user(struct selinux_state *state,
1934                                  u32 ssid, u32 tsid, u16 tclass,
1935                                  const char *objname, u32 *out_sid)
1936 {
1937         return security_compute_sid(state, ssid, tsid, tclass,
1938                                     AVTAB_TRANSITION,
1939                                     objname, out_sid, false);
1940 }
1941
1942 /**
1943  * security_member_sid - Compute the SID for member selection.
1944  * @state: SELinux state
1945  * @ssid: source security identifier
1946  * @tsid: target security identifier
1947  * @tclass: target security class
1948  * @out_sid: security identifier for selected member
1949  *
1950  * Compute a SID to use when selecting a member of a polyinstantiated
1951  * object of class @tclass based on a SID pair (@ssid, @tsid).
1952  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1953  * if insufficient memory is available, or %0 if the SID was
1954  * computed successfully.
1955  */
1956 int security_member_sid(struct selinux_state *state,
1957                         u32 ssid,
1958                         u32 tsid,
1959                         u16 tclass,
1960                         u32 *out_sid)
1961 {
1962         return security_compute_sid(state, ssid, tsid, tclass,
1963                                     AVTAB_MEMBER, NULL,
1964                                     out_sid, false);
1965 }
1966
1967 /**
1968  * security_change_sid - Compute the SID for object relabeling.
1969  * @state: SELinux state
1970  * @ssid: source security identifier
1971  * @tsid: target security identifier
1972  * @tclass: target security class
1973  * @out_sid: security identifier for selected member
1974  *
1975  * Compute a SID to use for relabeling an object of class @tclass
1976  * based on a SID pair (@ssid, @tsid).
1977  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1978  * if insufficient memory is available, or %0 if the SID was
1979  * computed successfully.
1980  */
1981 int security_change_sid(struct selinux_state *state,
1982                         u32 ssid,
1983                         u32 tsid,
1984                         u16 tclass,
1985                         u32 *out_sid)
1986 {
1987         return security_compute_sid(state,
1988                                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1989                                     out_sid, false);
1990 }
1991
1992 static inline int convert_context_handle_invalid_context(
1993         struct selinux_state *state,
1994         struct policydb *policydb,
1995         struct context *context)
1996 {
1997         char *s;
1998         u32 len;
1999
2000         if (enforcing_enabled(state))
2001                 return -EINVAL;
2002
2003         if (!context_struct_to_string(policydb, context, &s, &len)) {
2004                 pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
2005                         s);
2006                 kfree(s);
2007         }
2008         return 0;
2009 }
2010
2011 /**
2012  * services_convert_context - Convert a security context across policies.
2013  * @args: populated convert_context_args struct
2014  * @oldc: original context
2015  * @newc: converted context
2016  *
2017  * Convert the values in the security context structure @oldc from the values
2018  * specified in the policy @args->oldp to the values specified in the policy
2019  * @args->newp, storing the new context in @newc, and verifying that the
2020  * context is valid under the new policy.
2021  */
2022 int services_convert_context(struct convert_context_args *args,
2023                              struct context *oldc, struct context *newc)
2024 {
2025         struct ocontext *oc;
2026         struct role_datum *role;
2027         struct type_datum *typdatum;
2028         struct user_datum *usrdatum;
2029         char *s;
2030         u32 len;
2031         int rc;
2032
2033         if (oldc->str) {
2034                 s = kstrdup(oldc->str, GFP_KERNEL);
2035                 if (!s)
2036                         return -ENOMEM;
2037
2038                 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL);
2039                 if (rc == -EINVAL) {
2040                         /*
2041                          * Retain string representation for later mapping.
2042                          *
2043                          * IMPORTANT: We need to copy the contents of oldc->str
2044                          * back into s again because string_to_context_struct()
2045                          * may have garbled it.
2046                          */
2047                         memcpy(s, oldc->str, oldc->len);
2048                         context_init(newc);
2049                         newc->str = s;
2050                         newc->len = oldc->len;
2051                         return 0;
2052                 }
2053                 kfree(s);
2054                 if (rc) {
2055                         /* Other error condition, e.g. ENOMEM. */
2056                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
2057                                oldc->str, -rc);
2058                         return rc;
2059                 }
2060                 pr_info("SELinux:  Context %s became valid (mapped).\n",
2061                         oldc->str);
2062                 return 0;
2063         }
2064
2065         context_init(newc);
2066
2067         /* Convert the user. */
2068         usrdatum = symtab_search(&args->newp->p_users,
2069                                  sym_name(args->oldp, SYM_USERS, oldc->user - 1));
2070         if (!usrdatum)
2071                 goto bad;
2072         newc->user = usrdatum->value;
2073
2074         /* Convert the role. */
2075         role = symtab_search(&args->newp->p_roles,
2076                              sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2077         if (!role)
2078                 goto bad;
2079         newc->role = role->value;
2080
2081         /* Convert the type. */
2082         typdatum = symtab_search(&args->newp->p_types,
2083                                  sym_name(args->oldp, SYM_TYPES, oldc->type - 1));
2084         if (!typdatum)
2085                 goto bad;
2086         newc->type = typdatum->value;
2087
2088         /* Convert the MLS fields if dealing with MLS policies */
2089         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2090                 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2091                 if (rc)
2092                         goto bad;
2093         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2094                 /*
2095                  * Switching between non-MLS and MLS policy:
2096                  * ensure that the MLS fields of the context for all
2097                  * existing entries in the sidtab are filled in with a
2098                  * suitable default value, likely taken from one of the
2099                  * initial SIDs.
2100                  */
2101                 oc = args->newp->ocontexts[OCON_ISID];
2102                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2103                         oc = oc->next;
2104                 if (!oc) {
2105                         pr_err("SELinux:  unable to look up"
2106                                 " the initial SIDs list\n");
2107                         goto bad;
2108                 }
2109                 rc = mls_range_set(newc, &oc->context[0].range);
2110                 if (rc)
2111                         goto bad;
2112         }
2113
2114         /* Check the validity of the new context. */
2115         if (!policydb_context_isvalid(args->newp, newc)) {
2116                 rc = convert_context_handle_invalid_context(args->state,
2117                                                             args->oldp, oldc);
2118                 if (rc)
2119                         goto bad;
2120         }
2121
2122         return 0;
2123 bad:
2124         /* Map old representation to string and save it. */
2125         rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2126         if (rc)
2127                 return rc;
2128         context_destroy(newc);
2129         newc->str = s;
2130         newc->len = len;
2131         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2132                 newc->str);
2133         return 0;
2134 }
2135
2136 static void security_load_policycaps(struct selinux_state *state,
2137                                 struct selinux_policy *policy)
2138 {
2139         struct policydb *p;
2140         unsigned int i;
2141         struct ebitmap_node *node;
2142
2143         p = &policy->policydb;
2144
2145         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2146                 WRITE_ONCE(state->policycap[i],
2147                         ebitmap_get_bit(&p->policycaps, i));
2148
2149         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2150                 pr_info("SELinux:  policy capability %s=%d\n",
2151                         selinux_policycap_names[i],
2152                         ebitmap_get_bit(&p->policycaps, i));
2153
2154         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2155                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2156                         pr_info("SELinux:  unknown policy capability %u\n",
2157                                 i);
2158         }
2159 }
2160
2161 static int security_preserve_bools(struct selinux_policy *oldpolicy,
2162                                 struct selinux_policy *newpolicy);
2163
2164 static void selinux_policy_free(struct selinux_policy *policy)
2165 {
2166         if (!policy)
2167                 return;
2168
2169         sidtab_destroy(policy->sidtab);
2170         kfree(policy->map.mapping);
2171         policydb_destroy(&policy->policydb);
2172         kfree(policy->sidtab);
2173         kfree(policy);
2174 }
2175
2176 static void selinux_policy_cond_free(struct selinux_policy *policy)
2177 {
2178         cond_policydb_destroy_dup(&policy->policydb);
2179         kfree(policy);
2180 }
2181
2182 void selinux_policy_cancel(struct selinux_state *state,
2183                            struct selinux_load_state *load_state)
2184 {
2185         struct selinux_policy *oldpolicy;
2186
2187         oldpolicy = rcu_dereference_protected(state->policy,
2188                                         lockdep_is_held(&state->policy_mutex));
2189
2190         sidtab_cancel_convert(oldpolicy->sidtab);
2191         selinux_policy_free(load_state->policy);
2192         kfree(load_state->convert_data);
2193 }
2194
2195 static void selinux_notify_policy_change(struct selinux_state *state,
2196                                         u32 seqno)
2197 {
2198         /* Flush external caches and notify userspace of policy load */
2199         avc_ss_reset(state->avc, seqno);
2200         selnl_notify_policyload(seqno);
2201         selinux_status_update_policyload(state, seqno);
2202         selinux_netlbl_cache_invalidate();
2203         selinux_xfrm_notify_policyload();
2204         selinux_ima_measure_state_locked(state);
2205 }
2206
2207 void selinux_policy_commit(struct selinux_state *state,
2208                            struct selinux_load_state *load_state)
2209 {
2210         struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2211         unsigned long flags;
2212         u32 seqno;
2213
2214         oldpolicy = rcu_dereference_protected(state->policy,
2215                                         lockdep_is_held(&state->policy_mutex));
2216
2217         /* If switching between different policy types, log MLS status */
2218         if (oldpolicy) {
2219                 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2220                         pr_info("SELinux: Disabling MLS support...\n");
2221                 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2222                         pr_info("SELinux: Enabling MLS support...\n");
2223         }
2224
2225         /* Set latest granting seqno for new policy. */
2226         if (oldpolicy)
2227                 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2228         else
2229                 newpolicy->latest_granting = 1;
2230         seqno = newpolicy->latest_granting;
2231
2232         /* Install the new policy. */
2233         if (oldpolicy) {
2234                 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2235                 rcu_assign_pointer(state->policy, newpolicy);
2236                 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2237         } else {
2238                 rcu_assign_pointer(state->policy, newpolicy);
2239         }
2240
2241         /* Load the policycaps from the new policy */
2242         security_load_policycaps(state, newpolicy);
2243
2244         if (!selinux_initialized(state)) {
2245                 /*
2246                  * After first policy load, the security server is
2247                  * marked as initialized and ready to handle requests and
2248                  * any objects created prior to policy load are then labeled.
2249                  */
2250                 selinux_mark_initialized(state);
2251                 selinux_complete_init();
2252         }
2253
2254         /* Free the old policy */
2255         synchronize_rcu();
2256         selinux_policy_free(oldpolicy);
2257         kfree(load_state->convert_data);
2258
2259         /* Notify others of the policy change */
2260         selinux_notify_policy_change(state, seqno);
2261 }
2262
2263 /**
2264  * security_load_policy - Load a security policy configuration.
2265  * @state: SELinux state
2266  * @data: binary policy data
2267  * @len: length of data in bytes
2268  * @load_state: policy load state
2269  *
2270  * Load a new set of security policy configuration data,
2271  * validate it and convert the SID table as necessary.
2272  * This function will flush the access vector cache after
2273  * loading the new policy.
2274  */
2275 int security_load_policy(struct selinux_state *state, void *data, size_t len,
2276                          struct selinux_load_state *load_state)
2277 {
2278         struct selinux_policy *newpolicy, *oldpolicy;
2279         struct selinux_policy_convert_data *convert_data;
2280         int rc = 0;
2281         struct policy_file file = { data, len }, *fp = &file;
2282
2283         newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2284         if (!newpolicy)
2285                 return -ENOMEM;
2286
2287         newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2288         if (!newpolicy->sidtab) {
2289                 rc = -ENOMEM;
2290                 goto err_policy;
2291         }
2292
2293         rc = policydb_read(&newpolicy->policydb, fp);
2294         if (rc)
2295                 goto err_sidtab;
2296
2297         newpolicy->policydb.len = len;
2298         rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2299                                 &newpolicy->map);
2300         if (rc)
2301                 goto err_policydb;
2302
2303         rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2304         if (rc) {
2305                 pr_err("SELinux:  unable to load the initial SIDs\n");
2306                 goto err_mapping;
2307         }
2308
2309         if (!selinux_initialized(state)) {
2310                 /* First policy load, so no need to preserve state from old policy */
2311                 load_state->policy = newpolicy;
2312                 load_state->convert_data = NULL;
2313                 return 0;
2314         }
2315
2316         oldpolicy = rcu_dereference_protected(state->policy,
2317                                         lockdep_is_held(&state->policy_mutex));
2318
2319         /* Preserve active boolean values from the old policy */
2320         rc = security_preserve_bools(oldpolicy, newpolicy);
2321         if (rc) {
2322                 pr_err("SELinux:  unable to preserve booleans\n");
2323                 goto err_free_isids;
2324         }
2325
2326         /*
2327          * Convert the internal representations of contexts
2328          * in the new SID table.
2329          */
2330
2331         convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2332         if (!convert_data) {
2333                 rc = -ENOMEM;
2334                 goto err_free_isids;
2335         }
2336
2337         convert_data->args.state = state;
2338         convert_data->args.oldp = &oldpolicy->policydb;
2339         convert_data->args.newp = &newpolicy->policydb;
2340
2341         convert_data->sidtab_params.args = &convert_data->args;
2342         convert_data->sidtab_params.target = newpolicy->sidtab;
2343
2344         rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2345         if (rc) {
2346                 pr_err("SELinux:  unable to convert the internal"
2347                         " representation of contexts in the new SID"
2348                         " table\n");
2349                 goto err_free_convert_data;
2350         }
2351
2352         load_state->policy = newpolicy;
2353         load_state->convert_data = convert_data;
2354         return 0;
2355
2356 err_free_convert_data:
2357         kfree(convert_data);
2358 err_free_isids:
2359         sidtab_destroy(newpolicy->sidtab);
2360 err_mapping:
2361         kfree(newpolicy->map.mapping);
2362 err_policydb:
2363         policydb_destroy(&newpolicy->policydb);
2364 err_sidtab:
2365         kfree(newpolicy->sidtab);
2366 err_policy:
2367         kfree(newpolicy);
2368
2369         return rc;
2370 }
2371
2372 /**
2373  * ocontext_to_sid - Helper to safely get sid for an ocontext
2374  * @sidtab: SID table
2375  * @c: ocontext structure
2376  * @index: index of the context entry (0 or 1)
2377  * @out_sid: pointer to the resulting SID value
2378  *
2379  * For all ocontexts except OCON_ISID the SID fields are populated
2380  * on-demand when needed. Since updating the SID value is an SMP-sensitive
2381  * operation, this helper must be used to do that safely.
2382  *
2383  * WARNING: This function may return -ESTALE, indicating that the caller
2384  * must retry the operation after re-acquiring the policy pointer!
2385  */
2386 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2387                            size_t index, u32 *out_sid)
2388 {
2389         int rc;
2390         u32 sid;
2391
2392         /* Ensure the associated sidtab entry is visible to this thread. */
2393         sid = smp_load_acquire(&c->sid[index]);
2394         if (!sid) {
2395                 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2396                 if (rc)
2397                         return rc;
2398
2399                 /*
2400                  * Ensure the new sidtab entry is visible to other threads
2401                  * when they see the SID.
2402                  */
2403                 smp_store_release(&c->sid[index], sid);
2404         }
2405         *out_sid = sid;
2406         return 0;
2407 }
2408
2409 /**
2410  * security_port_sid - Obtain the SID for a port.
2411  * @state: SELinux state
2412  * @protocol: protocol number
2413  * @port: port number
2414  * @out_sid: security identifier
2415  */
2416 int security_port_sid(struct selinux_state *state,
2417                       u8 protocol, u16 port, u32 *out_sid)
2418 {
2419         struct selinux_policy *policy;
2420         struct policydb *policydb;
2421         struct sidtab *sidtab;
2422         struct ocontext *c;
2423         int rc;
2424
2425         if (!selinux_initialized(state)) {
2426                 *out_sid = SECINITSID_PORT;
2427                 return 0;
2428         }
2429
2430 retry:
2431         rc = 0;
2432         rcu_read_lock();
2433         policy = rcu_dereference(state->policy);
2434         policydb = &policy->policydb;
2435         sidtab = policy->sidtab;
2436
2437         c = policydb->ocontexts[OCON_PORT];
2438         while (c) {
2439                 if (c->u.port.protocol == protocol &&
2440                     c->u.port.low_port <= port &&
2441                     c->u.port.high_port >= port)
2442                         break;
2443                 c = c->next;
2444         }
2445
2446         if (c) {
2447                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2448                 if (rc == -ESTALE) {
2449                         rcu_read_unlock();
2450                         goto retry;
2451                 }
2452                 if (rc)
2453                         goto out;
2454         } else {
2455                 *out_sid = SECINITSID_PORT;
2456         }
2457
2458 out:
2459         rcu_read_unlock();
2460         return rc;
2461 }
2462
2463 /**
2464  * security_ib_pkey_sid - Obtain the SID for a pkey.
2465  * @state: SELinux state
2466  * @subnet_prefix: Subnet Prefix
2467  * @pkey_num: pkey number
2468  * @out_sid: security identifier
2469  */
2470 int security_ib_pkey_sid(struct selinux_state *state,
2471                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2472 {
2473         struct selinux_policy *policy;
2474         struct policydb *policydb;
2475         struct sidtab *sidtab;
2476         struct ocontext *c;
2477         int rc;
2478
2479         if (!selinux_initialized(state)) {
2480                 *out_sid = SECINITSID_UNLABELED;
2481                 return 0;
2482         }
2483
2484 retry:
2485         rc = 0;
2486         rcu_read_lock();
2487         policy = rcu_dereference(state->policy);
2488         policydb = &policy->policydb;
2489         sidtab = policy->sidtab;
2490
2491         c = policydb->ocontexts[OCON_IBPKEY];
2492         while (c) {
2493                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2494                     c->u.ibpkey.high_pkey >= pkey_num &&
2495                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2496                         break;
2497
2498                 c = c->next;
2499         }
2500
2501         if (c) {
2502                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2503                 if (rc == -ESTALE) {
2504                         rcu_read_unlock();
2505                         goto retry;
2506                 }
2507                 if (rc)
2508                         goto out;
2509         } else
2510                 *out_sid = SECINITSID_UNLABELED;
2511
2512 out:
2513         rcu_read_unlock();
2514         return rc;
2515 }
2516
2517 /**
2518  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2519  * @state: SELinux state
2520  * @dev_name: device name
2521  * @port_num: port number
2522  * @out_sid: security identifier
2523  */
2524 int security_ib_endport_sid(struct selinux_state *state,
2525                             const char *dev_name, u8 port_num, u32 *out_sid)
2526 {
2527         struct selinux_policy *policy;
2528         struct policydb *policydb;
2529         struct sidtab *sidtab;
2530         struct ocontext *c;
2531         int rc;
2532
2533         if (!selinux_initialized(state)) {
2534                 *out_sid = SECINITSID_UNLABELED;
2535                 return 0;
2536         }
2537
2538 retry:
2539         rc = 0;
2540         rcu_read_lock();
2541         policy = rcu_dereference(state->policy);
2542         policydb = &policy->policydb;
2543         sidtab = policy->sidtab;
2544
2545         c = policydb->ocontexts[OCON_IBENDPORT];
2546         while (c) {
2547                 if (c->u.ibendport.port == port_num &&
2548                     !strncmp(c->u.ibendport.dev_name,
2549                              dev_name,
2550                              IB_DEVICE_NAME_MAX))
2551                         break;
2552
2553                 c = c->next;
2554         }
2555
2556         if (c) {
2557                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2558                 if (rc == -ESTALE) {
2559                         rcu_read_unlock();
2560                         goto retry;
2561                 }
2562                 if (rc)
2563                         goto out;
2564         } else
2565                 *out_sid = SECINITSID_UNLABELED;
2566
2567 out:
2568         rcu_read_unlock();
2569         return rc;
2570 }
2571
2572 /**
2573  * security_netif_sid - Obtain the SID for a network interface.
2574  * @state: SELinux state
2575  * @name: interface name
2576  * @if_sid: interface SID
2577  */
2578 int security_netif_sid(struct selinux_state *state,
2579                        char *name, u32 *if_sid)
2580 {
2581         struct selinux_policy *policy;
2582         struct policydb *policydb;
2583         struct sidtab *sidtab;
2584         int rc;
2585         struct ocontext *c;
2586
2587         if (!selinux_initialized(state)) {
2588                 *if_sid = SECINITSID_NETIF;
2589                 return 0;
2590         }
2591
2592 retry:
2593         rc = 0;
2594         rcu_read_lock();
2595         policy = rcu_dereference(state->policy);
2596         policydb = &policy->policydb;
2597         sidtab = policy->sidtab;
2598
2599         c = policydb->ocontexts[OCON_NETIF];
2600         while (c) {
2601                 if (strcmp(name, c->u.name) == 0)
2602                         break;
2603                 c = c->next;
2604         }
2605
2606         if (c) {
2607                 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2608                 if (rc == -ESTALE) {
2609                         rcu_read_unlock();
2610                         goto retry;
2611                 }
2612                 if (rc)
2613                         goto out;
2614         } else
2615                 *if_sid = SECINITSID_NETIF;
2616
2617 out:
2618         rcu_read_unlock();
2619         return rc;
2620 }
2621
2622 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2623 {
2624         int i, fail = 0;
2625
2626         for (i = 0; i < 4; i++)
2627                 if (addr[i] != (input[i] & mask[i])) {
2628                         fail = 1;
2629                         break;
2630                 }
2631
2632         return !fail;
2633 }
2634
2635 /**
2636  * security_node_sid - Obtain the SID for a node (host).
2637  * @state: SELinux state
2638  * @domain: communication domain aka address family
2639  * @addrp: address
2640  * @addrlen: address length in bytes
2641  * @out_sid: security identifier
2642  */
2643 int security_node_sid(struct selinux_state *state,
2644                       u16 domain,
2645                       void *addrp,
2646                       u32 addrlen,
2647                       u32 *out_sid)
2648 {
2649         struct selinux_policy *policy;
2650         struct policydb *policydb;
2651         struct sidtab *sidtab;
2652         int rc;
2653         struct ocontext *c;
2654
2655         if (!selinux_initialized(state)) {
2656                 *out_sid = SECINITSID_NODE;
2657                 return 0;
2658         }
2659
2660 retry:
2661         rcu_read_lock();
2662         policy = rcu_dereference(state->policy);
2663         policydb = &policy->policydb;
2664         sidtab = policy->sidtab;
2665
2666         switch (domain) {
2667         case AF_INET: {
2668                 u32 addr;
2669
2670                 rc = -EINVAL;
2671                 if (addrlen != sizeof(u32))
2672                         goto out;
2673
2674                 addr = *((u32 *)addrp);
2675
2676                 c = policydb->ocontexts[OCON_NODE];
2677                 while (c) {
2678                         if (c->u.node.addr == (addr & c->u.node.mask))
2679                                 break;
2680                         c = c->next;
2681                 }
2682                 break;
2683         }
2684
2685         case AF_INET6:
2686                 rc = -EINVAL;
2687                 if (addrlen != sizeof(u64) * 2)
2688                         goto out;
2689                 c = policydb->ocontexts[OCON_NODE6];
2690                 while (c) {
2691                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2692                                                 c->u.node6.mask))
2693                                 break;
2694                         c = c->next;
2695                 }
2696                 break;
2697
2698         default:
2699                 rc = 0;
2700                 *out_sid = SECINITSID_NODE;
2701                 goto out;
2702         }
2703
2704         if (c) {
2705                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2706                 if (rc == -ESTALE) {
2707                         rcu_read_unlock();
2708                         goto retry;
2709                 }
2710                 if (rc)
2711                         goto out;
2712         } else {
2713                 *out_sid = SECINITSID_NODE;
2714         }
2715
2716         rc = 0;
2717 out:
2718         rcu_read_unlock();
2719         return rc;
2720 }
2721
2722 #define SIDS_NEL 25
2723
2724 /**
2725  * security_get_user_sids - Obtain reachable SIDs for a user.
2726  * @state: SELinux state
2727  * @fromsid: starting SID
2728  * @username: username
2729  * @sids: array of reachable SIDs for user
2730  * @nel: number of elements in @sids
2731  *
2732  * Generate the set of SIDs for legal security contexts
2733  * for a given user that can be reached by @fromsid.
2734  * Set *@sids to point to a dynamically allocated
2735  * array containing the set of SIDs.  Set *@nel to the
2736  * number of elements in the array.
2737  */
2738
2739 int security_get_user_sids(struct selinux_state *state,
2740                            u32 fromsid,
2741                            char *username,
2742                            u32 **sids,
2743                            u32 *nel)
2744 {
2745         struct selinux_policy *policy;
2746         struct policydb *policydb;
2747         struct sidtab *sidtab;
2748         struct context *fromcon, usercon;
2749         u32 *mysids = NULL, *mysids2, sid;
2750         u32 i, j, mynel, maxnel = SIDS_NEL;
2751         struct user_datum *user;
2752         struct role_datum *role;
2753         struct ebitmap_node *rnode, *tnode;
2754         int rc;
2755
2756         *sids = NULL;
2757         *nel = 0;
2758
2759         if (!selinux_initialized(state))
2760                 return 0;
2761
2762         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2763         if (!mysids)
2764                 return -ENOMEM;
2765
2766 retry:
2767         mynel = 0;
2768         rcu_read_lock();
2769         policy = rcu_dereference(state->policy);
2770         policydb = &policy->policydb;
2771         sidtab = policy->sidtab;
2772
2773         context_init(&usercon);
2774
2775         rc = -EINVAL;
2776         fromcon = sidtab_search(sidtab, fromsid);
2777         if (!fromcon)
2778                 goto out_unlock;
2779
2780         rc = -EINVAL;
2781         user = symtab_search(&policydb->p_users, username);
2782         if (!user)
2783                 goto out_unlock;
2784
2785         usercon.user = user->value;
2786
2787         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2788                 role = policydb->role_val_to_struct[i];
2789                 usercon.role = i + 1;
2790                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2791                         usercon.type = j + 1;
2792
2793                         if (mls_setup_user_range(policydb, fromcon, user,
2794                                                  &usercon))
2795                                 continue;
2796
2797                         rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2798                         if (rc == -ESTALE) {
2799                                 rcu_read_unlock();
2800                                 goto retry;
2801                         }
2802                         if (rc)
2803                                 goto out_unlock;
2804                         if (mynel < maxnel) {
2805                                 mysids[mynel++] = sid;
2806                         } else {
2807                                 rc = -ENOMEM;
2808                                 maxnel += SIDS_NEL;
2809                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2810                                 if (!mysids2)
2811                                         goto out_unlock;
2812                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2813                                 kfree(mysids);
2814                                 mysids = mysids2;
2815                                 mysids[mynel++] = sid;
2816                         }
2817                 }
2818         }
2819         rc = 0;
2820 out_unlock:
2821         rcu_read_unlock();
2822         if (rc || !mynel) {
2823                 kfree(mysids);
2824                 return rc;
2825         }
2826
2827         rc = -ENOMEM;
2828         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2829         if (!mysids2) {
2830                 kfree(mysids);
2831                 return rc;
2832         }
2833         for (i = 0, j = 0; i < mynel; i++) {
2834                 struct av_decision dummy_avd;
2835                 rc = avc_has_perm_noaudit(state,
2836                                           fromsid, mysids[i],
2837                                           SECCLASS_PROCESS, /* kernel value */
2838                                           PROCESS__TRANSITION, AVC_STRICT,
2839                                           &dummy_avd);
2840                 if (!rc)
2841                         mysids2[j++] = mysids[i];
2842                 cond_resched();
2843         }
2844         kfree(mysids);
2845         *sids = mysids2;
2846         *nel = j;
2847         return 0;
2848 }
2849
2850 /**
2851  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2852  * @policy: policy
2853  * @fstype: filesystem type
2854  * @path: path from root of mount
2855  * @orig_sclass: file security class
2856  * @sid: SID for path
2857  *
2858  * Obtain a SID to use for a file in a filesystem that
2859  * cannot support xattr or use a fixed labeling behavior like
2860  * transition SIDs or task SIDs.
2861  *
2862  * WARNING: This function may return -ESTALE, indicating that the caller
2863  * must retry the operation after re-acquiring the policy pointer!
2864  */
2865 static inline int __security_genfs_sid(struct selinux_policy *policy,
2866                                        const char *fstype,
2867                                        const char *path,
2868                                        u16 orig_sclass,
2869                                        u32 *sid)
2870 {
2871         struct policydb *policydb = &policy->policydb;
2872         struct sidtab *sidtab = policy->sidtab;
2873         int len;
2874         u16 sclass;
2875         struct genfs *genfs;
2876         struct ocontext *c;
2877         int cmp = 0;
2878
2879         while (path[0] == '/' && path[1] == '/')
2880                 path++;
2881
2882         sclass = unmap_class(&policy->map, orig_sclass);
2883         *sid = SECINITSID_UNLABELED;
2884
2885         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2886                 cmp = strcmp(fstype, genfs->fstype);
2887                 if (cmp <= 0)
2888                         break;
2889         }
2890
2891         if (!genfs || cmp)
2892                 return -ENOENT;
2893
2894         for (c = genfs->head; c; c = c->next) {
2895                 len = strlen(c->u.name);
2896                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2897                     (strncmp(c->u.name, path, len) == 0))
2898                         break;
2899         }
2900
2901         if (!c)
2902                 return -ENOENT;
2903
2904         return ocontext_to_sid(sidtab, c, 0, sid);
2905 }
2906
2907 /**
2908  * security_genfs_sid - Obtain a SID for a file in a filesystem
2909  * @state: SELinux state
2910  * @fstype: filesystem type
2911  * @path: path from root of mount
2912  * @orig_sclass: file security class
2913  * @sid: SID for path
2914  *
2915  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2916  * it afterward.
2917  */
2918 int security_genfs_sid(struct selinux_state *state,
2919                        const char *fstype,
2920                        const char *path,
2921                        u16 orig_sclass,
2922                        u32 *sid)
2923 {
2924         struct selinux_policy *policy;
2925         int retval;
2926
2927         if (!selinux_initialized(state)) {
2928                 *sid = SECINITSID_UNLABELED;
2929                 return 0;
2930         }
2931
2932         do {
2933                 rcu_read_lock();
2934                 policy = rcu_dereference(state->policy);
2935                 retval = __security_genfs_sid(policy, fstype, path,
2936                                               orig_sclass, sid);
2937                 rcu_read_unlock();
2938         } while (retval == -ESTALE);
2939         return retval;
2940 }
2941
2942 int selinux_policy_genfs_sid(struct selinux_policy *policy,
2943                         const char *fstype,
2944                         const char *path,
2945                         u16 orig_sclass,
2946                         u32 *sid)
2947 {
2948         /* no lock required, policy is not yet accessible by other threads */
2949         return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2950 }
2951
2952 /**
2953  * security_fs_use - Determine how to handle labeling for a filesystem.
2954  * @state: SELinux state
2955  * @sb: superblock in question
2956  */
2957 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2958 {
2959         struct selinux_policy *policy;
2960         struct policydb *policydb;
2961         struct sidtab *sidtab;
2962         int rc;
2963         struct ocontext *c;
2964         struct superblock_security_struct *sbsec = selinux_superblock(sb);
2965         const char *fstype = sb->s_type->name;
2966
2967         if (!selinux_initialized(state)) {
2968                 sbsec->behavior = SECURITY_FS_USE_NONE;
2969                 sbsec->sid = SECINITSID_UNLABELED;
2970                 return 0;
2971         }
2972
2973 retry:
2974         rcu_read_lock();
2975         policy = rcu_dereference(state->policy);
2976         policydb = &policy->policydb;
2977         sidtab = policy->sidtab;
2978
2979         c = policydb->ocontexts[OCON_FSUSE];
2980         while (c) {
2981                 if (strcmp(fstype, c->u.name) == 0)
2982                         break;
2983                 c = c->next;
2984         }
2985
2986         if (c) {
2987                 sbsec->behavior = c->v.behavior;
2988                 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2989                 if (rc == -ESTALE) {
2990                         rcu_read_unlock();
2991                         goto retry;
2992                 }
2993                 if (rc)
2994                         goto out;
2995         } else {
2996                 rc = __security_genfs_sid(policy, fstype, "/",
2997                                         SECCLASS_DIR, &sbsec->sid);
2998                 if (rc == -ESTALE) {
2999                         rcu_read_unlock();
3000                         goto retry;
3001                 }
3002                 if (rc) {
3003                         sbsec->behavior = SECURITY_FS_USE_NONE;
3004                         rc = 0;
3005                 } else {
3006                         sbsec->behavior = SECURITY_FS_USE_GENFS;
3007                 }
3008         }
3009
3010 out:
3011         rcu_read_unlock();
3012         return rc;
3013 }
3014
3015 int security_get_bools(struct selinux_policy *policy,
3016                        u32 *len, char ***names, int **values)
3017 {
3018         struct policydb *policydb;
3019         u32 i;
3020         int rc;
3021
3022         policydb = &policy->policydb;
3023
3024         *names = NULL;
3025         *values = NULL;
3026
3027         rc = 0;
3028         *len = policydb->p_bools.nprim;
3029         if (!*len)
3030                 goto out;
3031
3032         rc = -ENOMEM;
3033         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3034         if (!*names)
3035                 goto err;
3036
3037         rc = -ENOMEM;
3038         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3039         if (!*values)
3040                 goto err;
3041
3042         for (i = 0; i < *len; i++) {
3043                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3044
3045                 rc = -ENOMEM;
3046                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3047                                       GFP_ATOMIC);
3048                 if (!(*names)[i])
3049                         goto err;
3050         }
3051         rc = 0;
3052 out:
3053         return rc;
3054 err:
3055         if (*names) {
3056                 for (i = 0; i < *len; i++)
3057                         kfree((*names)[i]);
3058                 kfree(*names);
3059         }
3060         kfree(*values);
3061         *len = 0;
3062         *names = NULL;
3063         *values = NULL;
3064         goto out;
3065 }
3066
3067
3068 int security_set_bools(struct selinux_state *state, u32 len, int *values)
3069 {
3070         struct selinux_policy *newpolicy, *oldpolicy;
3071         int rc;
3072         u32 i, seqno = 0;
3073
3074         if (!selinux_initialized(state))
3075                 return -EINVAL;
3076
3077         oldpolicy = rcu_dereference_protected(state->policy,
3078                                         lockdep_is_held(&state->policy_mutex));
3079
3080         /* Consistency check on number of booleans, should never fail */
3081         if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3082                 return -EINVAL;
3083
3084         newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3085         if (!newpolicy)
3086                 return -ENOMEM;
3087
3088         /*
3089          * Deep copy only the parts of the policydb that might be
3090          * modified as a result of changing booleans.
3091          */
3092         rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3093         if (rc) {
3094                 kfree(newpolicy);
3095                 return -ENOMEM;
3096         }
3097
3098         /* Update the boolean states in the copy */
3099         for (i = 0; i < len; i++) {
3100                 int new_state = !!values[i];
3101                 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3102
3103                 if (new_state != old_state) {
3104                         audit_log(audit_context(), GFP_ATOMIC,
3105                                 AUDIT_MAC_CONFIG_CHANGE,
3106                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3107                                 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3108                                 new_state,
3109                                 old_state,
3110                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3111                                 audit_get_sessionid(current));
3112                         newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3113                 }
3114         }
3115
3116         /* Re-evaluate the conditional rules in the copy */
3117         evaluate_cond_nodes(&newpolicy->policydb);
3118
3119         /* Set latest granting seqno for new policy */
3120         newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3121         seqno = newpolicy->latest_granting;
3122
3123         /* Install the new policy */
3124         rcu_assign_pointer(state->policy, newpolicy);
3125
3126         /*
3127          * Free the conditional portions of the old policydb
3128          * that were copied for the new policy, and the oldpolicy
3129          * structure itself but not what it references.
3130          */
3131         synchronize_rcu();
3132         selinux_policy_cond_free(oldpolicy);
3133
3134         /* Notify others of the policy change */
3135         selinux_notify_policy_change(state, seqno);
3136         return 0;
3137 }
3138
3139 int security_get_bool_value(struct selinux_state *state,
3140                             u32 index)
3141 {
3142         struct selinux_policy *policy;
3143         struct policydb *policydb;
3144         int rc;
3145         u32 len;
3146
3147         if (!selinux_initialized(state))
3148                 return 0;
3149
3150         rcu_read_lock();
3151         policy = rcu_dereference(state->policy);
3152         policydb = &policy->policydb;
3153
3154         rc = -EFAULT;
3155         len = policydb->p_bools.nprim;
3156         if (index >= len)
3157                 goto out;
3158
3159         rc = policydb->bool_val_to_struct[index]->state;
3160 out:
3161         rcu_read_unlock();
3162         return rc;
3163 }
3164
3165 static int security_preserve_bools(struct selinux_policy *oldpolicy,
3166                                 struct selinux_policy *newpolicy)
3167 {
3168         int rc, *bvalues = NULL;
3169         char **bnames = NULL;
3170         struct cond_bool_datum *booldatum;
3171         u32 i, nbools = 0;
3172
3173         rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3174         if (rc)
3175                 goto out;
3176         for (i = 0; i < nbools; i++) {
3177                 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3178                                         bnames[i]);
3179                 if (booldatum)
3180                         booldatum->state = bvalues[i];
3181         }
3182         evaluate_cond_nodes(&newpolicy->policydb);
3183
3184 out:
3185         if (bnames) {
3186                 for (i = 0; i < nbools; i++)
3187                         kfree(bnames[i]);
3188         }
3189         kfree(bnames);
3190         kfree(bvalues);
3191         return rc;
3192 }
3193
3194 /*
3195  * security_sid_mls_copy() - computes a new sid based on the given
3196  * sid and the mls portion of mls_sid.
3197  */
3198 int security_sid_mls_copy(struct selinux_state *state,
3199                           u32 sid, u32 mls_sid, u32 *new_sid)
3200 {
3201         struct selinux_policy *policy;
3202         struct policydb *policydb;
3203         struct sidtab *sidtab;
3204         struct context *context1;
3205         struct context *context2;
3206         struct context newcon;
3207         char *s;
3208         u32 len;
3209         int rc;
3210
3211         if (!selinux_initialized(state)) {
3212                 *new_sid = sid;
3213                 return 0;
3214         }
3215
3216 retry:
3217         rc = 0;
3218         context_init(&newcon);
3219
3220         rcu_read_lock();
3221         policy = rcu_dereference(state->policy);
3222         policydb = &policy->policydb;
3223         sidtab = policy->sidtab;
3224
3225         if (!policydb->mls_enabled) {
3226                 *new_sid = sid;
3227                 goto out_unlock;
3228         }
3229
3230         rc = -EINVAL;
3231         context1 = sidtab_search(sidtab, sid);
3232         if (!context1) {
3233                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3234                         __func__, sid);
3235                 goto out_unlock;
3236         }
3237
3238         rc = -EINVAL;
3239         context2 = sidtab_search(sidtab, mls_sid);
3240         if (!context2) {
3241                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3242                         __func__, mls_sid);
3243                 goto out_unlock;
3244         }
3245
3246         newcon.user = context1->user;
3247         newcon.role = context1->role;
3248         newcon.type = context1->type;
3249         rc = mls_context_cpy(&newcon, context2);
3250         if (rc)
3251                 goto out_unlock;
3252
3253         /* Check the validity of the new context. */
3254         if (!policydb_context_isvalid(policydb, &newcon)) {
3255                 rc = convert_context_handle_invalid_context(state, policydb,
3256                                                         &newcon);
3257                 if (rc) {
3258                         if (!context_struct_to_string(policydb, &newcon, &s,
3259                                                       &len)) {
3260                                 struct audit_buffer *ab;
3261
3262                                 ab = audit_log_start(audit_context(),
3263                                                      GFP_ATOMIC,
3264                                                      AUDIT_SELINUX_ERR);
3265                                 audit_log_format(ab,
3266                                                  "op=security_sid_mls_copy invalid_context=");
3267                                 /* don't record NUL with untrusted strings */
3268                                 audit_log_n_untrustedstring(ab, s, len - 1);
3269                                 audit_log_end(ab);
3270                                 kfree(s);
3271                         }
3272                         goto out_unlock;
3273                 }
3274         }
3275         rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3276         if (rc == -ESTALE) {
3277                 rcu_read_unlock();
3278                 context_destroy(&newcon);
3279                 goto retry;
3280         }
3281 out_unlock:
3282         rcu_read_unlock();
3283         context_destroy(&newcon);
3284         return rc;
3285 }
3286
3287 /**
3288  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3289  * @state: SELinux state
3290  * @nlbl_sid: NetLabel SID
3291  * @nlbl_type: NetLabel labeling protocol type
3292  * @xfrm_sid: XFRM SID
3293  * @peer_sid: network peer sid
3294  *
3295  * Description:
3296  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3297  * resolved into a single SID it is returned via @peer_sid and the function
3298  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3299  * returns a negative value.  A table summarizing the behavior is below:
3300  *
3301  *                                 | function return |      @sid
3302  *   ------------------------------+-----------------+-----------------
3303  *   no peer labels                |        0        |    SECSID_NULL
3304  *   single peer label             |        0        |    <peer_label>
3305  *   multiple, consistent labels   |        0        |    <peer_label>
3306  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3307  *
3308  */
3309 int security_net_peersid_resolve(struct selinux_state *state,
3310                                  u32 nlbl_sid, u32 nlbl_type,
3311                                  u32 xfrm_sid,
3312                                  u32 *peer_sid)
3313 {
3314         struct selinux_policy *policy;
3315         struct policydb *policydb;
3316         struct sidtab *sidtab;
3317         int rc;
3318         struct context *nlbl_ctx;
3319         struct context *xfrm_ctx;
3320
3321         *peer_sid = SECSID_NULL;
3322
3323         /* handle the common (which also happens to be the set of easy) cases
3324          * right away, these two if statements catch everything involving a
3325          * single or absent peer SID/label */
3326         if (xfrm_sid == SECSID_NULL) {
3327                 *peer_sid = nlbl_sid;
3328                 return 0;
3329         }
3330         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3331          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3332          * is present */
3333         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3334                 *peer_sid = xfrm_sid;
3335                 return 0;
3336         }
3337
3338         if (!selinux_initialized(state))
3339                 return 0;
3340
3341         rcu_read_lock();
3342         policy = rcu_dereference(state->policy);
3343         policydb = &policy->policydb;
3344         sidtab = policy->sidtab;
3345
3346         /*
3347          * We don't need to check initialized here since the only way both
3348          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3349          * security server was initialized and state->initialized was true.
3350          */
3351         if (!policydb->mls_enabled) {
3352                 rc = 0;
3353                 goto out;
3354         }
3355
3356         rc = -EINVAL;
3357         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3358         if (!nlbl_ctx) {
3359                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3360                        __func__, nlbl_sid);
3361                 goto out;
3362         }
3363         rc = -EINVAL;
3364         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3365         if (!xfrm_ctx) {
3366                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3367                        __func__, xfrm_sid);
3368                 goto out;
3369         }
3370         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3371         if (rc)
3372                 goto out;
3373
3374         /* at present NetLabel SIDs/labels really only carry MLS
3375          * information so if the MLS portion of the NetLabel SID
3376          * matches the MLS portion of the labeled XFRM SID/label
3377          * then pass along the XFRM SID as it is the most
3378          * expressive */
3379         *peer_sid = xfrm_sid;
3380 out:
3381         rcu_read_unlock();
3382         return rc;
3383 }
3384
3385 static int get_classes_callback(void *k, void *d, void *args)
3386 {
3387         struct class_datum *datum = d;
3388         char *name = k, **classes = args;
3389         int value = datum->value - 1;
3390
3391         classes[value] = kstrdup(name, GFP_ATOMIC);
3392         if (!classes[value])
3393                 return -ENOMEM;
3394
3395         return 0;
3396 }
3397
3398 int security_get_classes(struct selinux_policy *policy,
3399                          char ***classes, int *nclasses)
3400 {
3401         struct policydb *policydb;
3402         int rc;
3403
3404         policydb = &policy->policydb;
3405
3406         rc = -ENOMEM;
3407         *nclasses = policydb->p_classes.nprim;
3408         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3409         if (!*classes)
3410                 goto out;
3411
3412         rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3413                          *classes);
3414         if (rc) {
3415                 int i;
3416                 for (i = 0; i < *nclasses; i++)
3417                         kfree((*classes)[i]);
3418                 kfree(*classes);
3419         }
3420
3421 out:
3422         return rc;
3423 }
3424
3425 static int get_permissions_callback(void *k, void *d, void *args)
3426 {
3427         struct perm_datum *datum = d;
3428         char *name = k, **perms = args;
3429         int value = datum->value - 1;
3430
3431         perms[value] = kstrdup(name, GFP_ATOMIC);
3432         if (!perms[value])
3433                 return -ENOMEM;
3434
3435         return 0;
3436 }
3437
3438 int security_get_permissions(struct selinux_policy *policy,
3439                              char *class, char ***perms, int *nperms)
3440 {
3441         struct policydb *policydb;
3442         int rc, i;
3443         struct class_datum *match;
3444
3445         policydb = &policy->policydb;
3446
3447         rc = -EINVAL;
3448         match = symtab_search(&policydb->p_classes, class);
3449         if (!match) {
3450                 pr_err("SELinux: %s:  unrecognized class %s\n",
3451                         __func__, class);
3452                 goto out;
3453         }
3454
3455         rc = -ENOMEM;
3456         *nperms = match->permissions.nprim;
3457         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3458         if (!*perms)
3459                 goto out;
3460
3461         if (match->comdatum) {
3462                 rc = hashtab_map(&match->comdatum->permissions.table,
3463                                  get_permissions_callback, *perms);
3464                 if (rc)
3465                         goto err;
3466         }
3467
3468         rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3469                          *perms);
3470         if (rc)
3471                 goto err;
3472
3473 out:
3474         return rc;
3475
3476 err:
3477         for (i = 0; i < *nperms; i++)
3478                 kfree((*perms)[i]);
3479         kfree(*perms);
3480         return rc;
3481 }
3482
3483 int security_get_reject_unknown(struct selinux_state *state)
3484 {
3485         struct selinux_policy *policy;
3486         int value;
3487
3488         if (!selinux_initialized(state))
3489                 return 0;
3490
3491         rcu_read_lock();
3492         policy = rcu_dereference(state->policy);
3493         value = policy->policydb.reject_unknown;
3494         rcu_read_unlock();
3495         return value;
3496 }
3497
3498 int security_get_allow_unknown(struct selinux_state *state)
3499 {
3500         struct selinux_policy *policy;
3501         int value;
3502
3503         if (!selinux_initialized(state))
3504                 return 0;
3505
3506         rcu_read_lock();
3507         policy = rcu_dereference(state->policy);
3508         value = policy->policydb.allow_unknown;
3509         rcu_read_unlock();
3510         return value;
3511 }
3512
3513 /**
3514  * security_policycap_supported - Check for a specific policy capability
3515  * @state: SELinux state
3516  * @req_cap: capability
3517  *
3518  * Description:
3519  * This function queries the currently loaded policy to see if it supports the
3520  * capability specified by @req_cap.  Returns true (1) if the capability is
3521  * supported, false (0) if it isn't supported.
3522  *
3523  */
3524 int security_policycap_supported(struct selinux_state *state,
3525                                  unsigned int req_cap)
3526 {
3527         struct selinux_policy *policy;
3528         int rc;
3529
3530         if (!selinux_initialized(state))
3531                 return 0;
3532
3533         rcu_read_lock();
3534         policy = rcu_dereference(state->policy);
3535         rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3536         rcu_read_unlock();
3537
3538         return rc;
3539 }
3540
3541 struct selinux_audit_rule {
3542         u32 au_seqno;
3543         struct context au_ctxt;
3544 };
3545
3546 void selinux_audit_rule_free(void *vrule)
3547 {
3548         struct selinux_audit_rule *rule = vrule;
3549
3550         if (rule) {
3551                 context_destroy(&rule->au_ctxt);
3552                 kfree(rule);
3553         }
3554 }
3555
3556 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3557 {
3558         struct selinux_state *state = &selinux_state;
3559         struct selinux_policy *policy;
3560         struct policydb *policydb;
3561         struct selinux_audit_rule *tmprule;
3562         struct role_datum *roledatum;
3563         struct type_datum *typedatum;
3564         struct user_datum *userdatum;
3565         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3566         int rc = 0;
3567
3568         *rule = NULL;
3569
3570         if (!selinux_initialized(state))
3571                 return -EOPNOTSUPP;
3572
3573         switch (field) {
3574         case AUDIT_SUBJ_USER:
3575         case AUDIT_SUBJ_ROLE:
3576         case AUDIT_SUBJ_TYPE:
3577         case AUDIT_OBJ_USER:
3578         case AUDIT_OBJ_ROLE:
3579         case AUDIT_OBJ_TYPE:
3580                 /* only 'equals' and 'not equals' fit user, role, and type */
3581                 if (op != Audit_equal && op != Audit_not_equal)
3582                         return -EINVAL;
3583                 break;
3584         case AUDIT_SUBJ_SEN:
3585         case AUDIT_SUBJ_CLR:
3586         case AUDIT_OBJ_LEV_LOW:
3587         case AUDIT_OBJ_LEV_HIGH:
3588                 /* we do not allow a range, indicated by the presence of '-' */
3589                 if (strchr(rulestr, '-'))
3590                         return -EINVAL;
3591                 break;
3592         default:
3593                 /* only the above fields are valid */
3594                 return -EINVAL;
3595         }
3596
3597         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3598         if (!tmprule)
3599                 return -ENOMEM;
3600
3601         context_init(&tmprule->au_ctxt);
3602
3603         rcu_read_lock();
3604         policy = rcu_dereference(state->policy);
3605         policydb = &policy->policydb;
3606
3607         tmprule->au_seqno = policy->latest_granting;
3608
3609         switch (field) {
3610         case AUDIT_SUBJ_USER:
3611         case AUDIT_OBJ_USER:
3612                 rc = -EINVAL;
3613                 userdatum = symtab_search(&policydb->p_users, rulestr);
3614                 if (!userdatum)
3615                         goto out;
3616                 tmprule->au_ctxt.user = userdatum->value;
3617                 break;
3618         case AUDIT_SUBJ_ROLE:
3619         case AUDIT_OBJ_ROLE:
3620                 rc = -EINVAL;
3621                 roledatum = symtab_search(&policydb->p_roles, rulestr);
3622                 if (!roledatum)
3623                         goto out;
3624                 tmprule->au_ctxt.role = roledatum->value;
3625                 break;
3626         case AUDIT_SUBJ_TYPE:
3627         case AUDIT_OBJ_TYPE:
3628                 rc = -EINVAL;
3629                 typedatum = symtab_search(&policydb->p_types, rulestr);
3630                 if (!typedatum)
3631                         goto out;
3632                 tmprule->au_ctxt.type = typedatum->value;
3633                 break;
3634         case AUDIT_SUBJ_SEN:
3635         case AUDIT_SUBJ_CLR:
3636         case AUDIT_OBJ_LEV_LOW:
3637         case AUDIT_OBJ_LEV_HIGH:
3638                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3639                                      GFP_ATOMIC);
3640                 if (rc)
3641                         goto out;
3642                 break;
3643         }
3644         rc = 0;
3645 out:
3646         rcu_read_unlock();
3647
3648         if (rc) {
3649                 selinux_audit_rule_free(tmprule);
3650                 tmprule = NULL;
3651         }
3652
3653         *rule = tmprule;
3654
3655         return rc;
3656 }
3657
3658 /* Check to see if the rule contains any selinux fields */
3659 int selinux_audit_rule_known(struct audit_krule *rule)
3660 {
3661         int i;
3662
3663         for (i = 0; i < rule->field_count; i++) {
3664                 struct audit_field *f = &rule->fields[i];
3665                 switch (f->type) {
3666                 case AUDIT_SUBJ_USER:
3667                 case AUDIT_SUBJ_ROLE:
3668                 case AUDIT_SUBJ_TYPE:
3669                 case AUDIT_SUBJ_SEN:
3670                 case AUDIT_SUBJ_CLR:
3671                 case AUDIT_OBJ_USER:
3672                 case AUDIT_OBJ_ROLE:
3673                 case AUDIT_OBJ_TYPE:
3674                 case AUDIT_OBJ_LEV_LOW:
3675                 case AUDIT_OBJ_LEV_HIGH:
3676                         return 1;
3677                 }
3678         }
3679
3680         return 0;
3681 }
3682
3683 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3684 {
3685         struct selinux_state *state = &selinux_state;
3686         struct selinux_policy *policy;
3687         struct context *ctxt;
3688         struct mls_level *level;
3689         struct selinux_audit_rule *rule = vrule;
3690         int match = 0;
3691
3692         if (unlikely(!rule)) {
3693                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3694                 return -ENOENT;
3695         }
3696
3697         if (!selinux_initialized(state))
3698                 return 0;
3699
3700         rcu_read_lock();
3701
3702         policy = rcu_dereference(state->policy);
3703
3704         if (rule->au_seqno < policy->latest_granting) {
3705                 match = -ESTALE;
3706                 goto out;
3707         }
3708
3709         ctxt = sidtab_search(policy->sidtab, sid);
3710         if (unlikely(!ctxt)) {
3711                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3712                           sid);
3713                 match = -ENOENT;
3714                 goto out;
3715         }
3716
3717         /* a field/op pair that is not caught here will simply fall through
3718            without a match */
3719         switch (field) {
3720         case AUDIT_SUBJ_USER:
3721         case AUDIT_OBJ_USER:
3722                 switch (op) {
3723                 case Audit_equal:
3724                         match = (ctxt->user == rule->au_ctxt.user);
3725                         break;
3726                 case Audit_not_equal:
3727                         match = (ctxt->user != rule->au_ctxt.user);
3728                         break;
3729                 }
3730                 break;
3731         case AUDIT_SUBJ_ROLE:
3732         case AUDIT_OBJ_ROLE:
3733                 switch (op) {
3734                 case Audit_equal:
3735                         match = (ctxt->role == rule->au_ctxt.role);
3736                         break;
3737                 case Audit_not_equal:
3738                         match = (ctxt->role != rule->au_ctxt.role);
3739                         break;
3740                 }
3741                 break;
3742         case AUDIT_SUBJ_TYPE:
3743         case AUDIT_OBJ_TYPE:
3744                 switch (op) {
3745                 case Audit_equal:
3746                         match = (ctxt->type == rule->au_ctxt.type);
3747                         break;
3748                 case Audit_not_equal:
3749                         match = (ctxt->type != rule->au_ctxt.type);
3750                         break;
3751                 }
3752                 break;
3753         case AUDIT_SUBJ_SEN:
3754         case AUDIT_SUBJ_CLR:
3755         case AUDIT_OBJ_LEV_LOW:
3756         case AUDIT_OBJ_LEV_HIGH:
3757                 level = ((field == AUDIT_SUBJ_SEN ||
3758                           field == AUDIT_OBJ_LEV_LOW) ?
3759                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3760                 switch (op) {
3761                 case Audit_equal:
3762                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3763                                              level);
3764                         break;
3765                 case Audit_not_equal:
3766                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3767                                               level);
3768                         break;
3769                 case Audit_lt:
3770                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3771                                                level) &&
3772                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3773                                                level));
3774                         break;
3775                 case Audit_le:
3776                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3777                                               level);
3778                         break;
3779                 case Audit_gt:
3780                         match = (mls_level_dom(level,
3781                                               &rule->au_ctxt.range.level[0]) &&
3782                                  !mls_level_eq(level,
3783                                                &rule->au_ctxt.range.level[0]));
3784                         break;
3785                 case Audit_ge:
3786                         match = mls_level_dom(level,
3787                                               &rule->au_ctxt.range.level[0]);
3788                         break;
3789                 }
3790         }
3791
3792 out:
3793         rcu_read_unlock();
3794         return match;
3795 }
3796
3797 static int aurule_avc_callback(u32 event)
3798 {
3799         if (event == AVC_CALLBACK_RESET)
3800                 return audit_update_lsm_rules();
3801         return 0;
3802 }
3803
3804 static int __init aurule_init(void)
3805 {
3806         int err;
3807
3808         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3809         if (err)
3810                 panic("avc_add_callback() failed, error %d\n", err);
3811
3812         return err;
3813 }
3814 __initcall(aurule_init);
3815
3816 #ifdef CONFIG_NETLABEL
3817 /**
3818  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3819  * @secattr: the NetLabel packet security attributes
3820  * @sid: the SELinux SID
3821  *
3822  * Description:
3823  * Attempt to cache the context in @ctx, which was derived from the packet in
3824  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3825  * already been initialized.
3826  *
3827  */
3828 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3829                                       u32 sid)
3830 {
3831         u32 *sid_cache;
3832
3833         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3834         if (sid_cache == NULL)
3835                 return;
3836         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3837         if (secattr->cache == NULL) {
3838                 kfree(sid_cache);
3839                 return;
3840         }
3841
3842         *sid_cache = sid;
3843         secattr->cache->free = kfree;
3844         secattr->cache->data = sid_cache;
3845         secattr->flags |= NETLBL_SECATTR_CACHE;
3846 }
3847
3848 /**
3849  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3850  * @state: SELinux state
3851  * @secattr: the NetLabel packet security attributes
3852  * @sid: the SELinux SID
3853  *
3854  * Description:
3855  * Convert the given NetLabel security attributes in @secattr into a
3856  * SELinux SID.  If the @secattr field does not contain a full SELinux
3857  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3858  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3859  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3860  * conversion for future lookups.  Returns zero on success, negative values on
3861  * failure.
3862  *
3863  */
3864 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3865                                    struct netlbl_lsm_secattr *secattr,
3866                                    u32 *sid)
3867 {
3868         struct selinux_policy *policy;
3869         struct policydb *policydb;
3870         struct sidtab *sidtab;
3871         int rc;
3872         struct context *ctx;
3873         struct context ctx_new;
3874
3875         if (!selinux_initialized(state)) {
3876                 *sid = SECSID_NULL;
3877                 return 0;
3878         }
3879
3880 retry:
3881         rc = 0;
3882         rcu_read_lock();
3883         policy = rcu_dereference(state->policy);
3884         policydb = &policy->policydb;
3885         sidtab = policy->sidtab;
3886
3887         if (secattr->flags & NETLBL_SECATTR_CACHE)
3888                 *sid = *(u32 *)secattr->cache->data;
3889         else if (secattr->flags & NETLBL_SECATTR_SECID)
3890                 *sid = secattr->attr.secid;
3891         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3892                 rc = -EIDRM;
3893                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3894                 if (ctx == NULL)
3895                         goto out;
3896
3897                 context_init(&ctx_new);
3898                 ctx_new.user = ctx->user;
3899                 ctx_new.role = ctx->role;
3900                 ctx_new.type = ctx->type;
3901                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3902                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3903                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3904                         if (rc)
3905                                 goto out;
3906                 }
3907                 rc = -EIDRM;
3908                 if (!mls_context_isvalid(policydb, &ctx_new)) {
3909                         ebitmap_destroy(&ctx_new.range.level[0].cat);
3910                         goto out;
3911                 }
3912
3913                 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3914                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3915                 if (rc == -ESTALE) {
3916                         rcu_read_unlock();
3917                         goto retry;
3918                 }
3919                 if (rc)
3920                         goto out;
3921
3922                 security_netlbl_cache_add(secattr, *sid);
3923         } else
3924                 *sid = SECSID_NULL;
3925
3926 out:
3927         rcu_read_unlock();
3928         return rc;
3929 }
3930
3931 /**
3932  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3933  * @state: SELinux state
3934  * @sid: the SELinux SID
3935  * @secattr: the NetLabel packet security attributes
3936  *
3937  * Description:
3938  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3939  * Returns zero on success, negative values on failure.
3940  *
3941  */
3942 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3943                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3944 {
3945         struct selinux_policy *policy;
3946         struct policydb *policydb;
3947         int rc;
3948         struct context *ctx;
3949
3950         if (!selinux_initialized(state))
3951                 return 0;
3952
3953         rcu_read_lock();
3954         policy = rcu_dereference(state->policy);
3955         policydb = &policy->policydb;
3956
3957         rc = -ENOENT;
3958         ctx = sidtab_search(policy->sidtab, sid);
3959         if (ctx == NULL)
3960                 goto out;
3961
3962         rc = -ENOMEM;
3963         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3964                                   GFP_ATOMIC);
3965         if (secattr->domain == NULL)
3966                 goto out;
3967
3968         secattr->attr.secid = sid;
3969         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3970         mls_export_netlbl_lvl(policydb, ctx, secattr);
3971         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3972 out:
3973         rcu_read_unlock();
3974         return rc;
3975 }
3976 #endif /* CONFIG_NETLABEL */
3977
3978 /**
3979  * __security_read_policy - read the policy.
3980  * @policy: SELinux policy
3981  * @data: binary policy data
3982  * @len: length of data in bytes
3983  *
3984  */
3985 static int __security_read_policy(struct selinux_policy *policy,
3986                                   void *data, size_t *len)
3987 {
3988         int rc;
3989         struct policy_file fp;
3990
3991         fp.data = data;
3992         fp.len = *len;
3993
3994         rc = policydb_write(&policy->policydb, &fp);
3995         if (rc)
3996                 return rc;
3997
3998         *len = (unsigned long)fp.data - (unsigned long)data;
3999         return 0;
4000 }
4001
4002 /**
4003  * security_read_policy - read the policy.
4004  * @state: selinux_state
4005  * @data: binary policy data
4006  * @len: length of data in bytes
4007  *
4008  */
4009 int security_read_policy(struct selinux_state *state,
4010                          void **data, size_t *len)
4011 {
4012         struct selinux_policy *policy;
4013
4014         policy = rcu_dereference_protected(
4015                         state->policy, lockdep_is_held(&state->policy_mutex));
4016         if (!policy)
4017                 return -EINVAL;
4018
4019         *len = policy->policydb.len;
4020         *data = vmalloc_user(*len);
4021         if (!*data)
4022                 return -ENOMEM;
4023
4024         return __security_read_policy(policy, *data, len);
4025 }
4026
4027 /**
4028  * security_read_state_kernel - read the policy.
4029  * @state: selinux_state
4030  * @data: binary policy data
4031  * @len: length of data in bytes
4032  *
4033  * Allocates kernel memory for reading SELinux policy.
4034  * This function is for internal use only and should not
4035  * be used for returning data to user space.
4036  *
4037  * This function must be called with policy_mutex held.
4038  */
4039 int security_read_state_kernel(struct selinux_state *state,
4040                                void **data, size_t *len)
4041 {
4042         int err;
4043         struct selinux_policy *policy;
4044
4045         policy = rcu_dereference_protected(
4046                         state->policy, lockdep_is_held(&state->policy_mutex));
4047         if (!policy)
4048                 return -EINVAL;
4049
4050         *len = policy->policydb.len;
4051         *data = vmalloc(*len);
4052         if (!*data)
4053                 return -ENOMEM;
4054
4055         err = __security_read_policy(policy, *data, len);
4056         if (err) {
4057                 vfree(*data);
4058                 *data = NULL;
4059                 *len = 0;
4060         }
4061         return err;
4062 }