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  * @gfp_flags: allocation flags
2017  *
2018  * Convert the values in the security context structure @oldc from the values
2019  * specified in the policy @args->oldp to the values specified in the policy
2020  * @args->newp, storing the new context in @newc, and verifying that the
2021  * context is valid under the new policy.
2022  */
2023 int services_convert_context(struct convert_context_args *args,
2024                              struct context *oldc, struct context *newc,
2025                              gfp_t gfp_flags)
2026 {
2027         struct ocontext *oc;
2028         struct role_datum *role;
2029         struct type_datum *typdatum;
2030         struct user_datum *usrdatum;
2031         char *s;
2032         u32 len;
2033         int rc;
2034
2035         if (oldc->str) {
2036                 s = kstrdup(oldc->str, gfp_flags);
2037                 if (!s)
2038                         return -ENOMEM;
2039
2040                 rc = string_to_context_struct(args->newp, NULL, s, newc, SECSID_NULL);
2041                 if (rc == -EINVAL) {
2042                         /*
2043                          * Retain string representation for later mapping.
2044                          *
2045                          * IMPORTANT: We need to copy the contents of oldc->str
2046                          * back into s again because string_to_context_struct()
2047                          * may have garbled it.
2048                          */
2049                         memcpy(s, oldc->str, oldc->len);
2050                         context_init(newc);
2051                         newc->str = s;
2052                         newc->len = oldc->len;
2053                         return 0;
2054                 }
2055                 kfree(s);
2056                 if (rc) {
2057                         /* Other error condition, e.g. ENOMEM. */
2058                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
2059                                oldc->str, -rc);
2060                         return rc;
2061                 }
2062                 pr_info("SELinux:  Context %s became valid (mapped).\n",
2063                         oldc->str);
2064                 return 0;
2065         }
2066
2067         context_init(newc);
2068
2069         /* Convert the user. */
2070         usrdatum = symtab_search(&args->newp->p_users,
2071                                  sym_name(args->oldp, SYM_USERS, oldc->user - 1));
2072         if (!usrdatum)
2073                 goto bad;
2074         newc->user = usrdatum->value;
2075
2076         /* Convert the role. */
2077         role = symtab_search(&args->newp->p_roles,
2078                              sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2079         if (!role)
2080                 goto bad;
2081         newc->role = role->value;
2082
2083         /* Convert the type. */
2084         typdatum = symtab_search(&args->newp->p_types,
2085                                  sym_name(args->oldp, SYM_TYPES, oldc->type - 1));
2086         if (!typdatum)
2087                 goto bad;
2088         newc->type = typdatum->value;
2089
2090         /* Convert the MLS fields if dealing with MLS policies */
2091         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2092                 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2093                 if (rc)
2094                         goto bad;
2095         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2096                 /*
2097                  * Switching between non-MLS and MLS policy:
2098                  * ensure that the MLS fields of the context for all
2099                  * existing entries in the sidtab are filled in with a
2100                  * suitable default value, likely taken from one of the
2101                  * initial SIDs.
2102                  */
2103                 oc = args->newp->ocontexts[OCON_ISID];
2104                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2105                         oc = oc->next;
2106                 if (!oc) {
2107                         pr_err("SELinux:  unable to look up"
2108                                 " the initial SIDs list\n");
2109                         goto bad;
2110                 }
2111                 rc = mls_range_set(newc, &oc->context[0].range);
2112                 if (rc)
2113                         goto bad;
2114         }
2115
2116         /* Check the validity of the new context. */
2117         if (!policydb_context_isvalid(args->newp, newc)) {
2118                 rc = convert_context_handle_invalid_context(args->state,
2119                                                             args->oldp, oldc);
2120                 if (rc)
2121                         goto bad;
2122         }
2123
2124         return 0;
2125 bad:
2126         /* Map old representation to string and save it. */
2127         rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2128         if (rc)
2129                 return rc;
2130         context_destroy(newc);
2131         newc->str = s;
2132         newc->len = len;
2133         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2134                 newc->str);
2135         return 0;
2136 }
2137
2138 static void security_load_policycaps(struct selinux_state *state,
2139                                 struct selinux_policy *policy)
2140 {
2141         struct policydb *p;
2142         unsigned int i;
2143         struct ebitmap_node *node;
2144
2145         p = &policy->policydb;
2146
2147         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2148                 WRITE_ONCE(state->policycap[i],
2149                         ebitmap_get_bit(&p->policycaps, i));
2150
2151         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2152                 pr_info("SELinux:  policy capability %s=%d\n",
2153                         selinux_policycap_names[i],
2154                         ebitmap_get_bit(&p->policycaps, i));
2155
2156         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2157                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2158                         pr_info("SELinux:  unknown policy capability %u\n",
2159                                 i);
2160         }
2161 }
2162
2163 static int security_preserve_bools(struct selinux_policy *oldpolicy,
2164                                 struct selinux_policy *newpolicy);
2165
2166 static void selinux_policy_free(struct selinux_policy *policy)
2167 {
2168         if (!policy)
2169                 return;
2170
2171         sidtab_destroy(policy->sidtab);
2172         kfree(policy->map.mapping);
2173         policydb_destroy(&policy->policydb);
2174         kfree(policy->sidtab);
2175         kfree(policy);
2176 }
2177
2178 static void selinux_policy_cond_free(struct selinux_policy *policy)
2179 {
2180         cond_policydb_destroy_dup(&policy->policydb);
2181         kfree(policy);
2182 }
2183
2184 void selinux_policy_cancel(struct selinux_state *state,
2185                            struct selinux_load_state *load_state)
2186 {
2187         struct selinux_policy *oldpolicy;
2188
2189         oldpolicy = rcu_dereference_protected(state->policy,
2190                                         lockdep_is_held(&state->policy_mutex));
2191
2192         sidtab_cancel_convert(oldpolicy->sidtab);
2193         selinux_policy_free(load_state->policy);
2194         kfree(load_state->convert_data);
2195 }
2196
2197 static void selinux_notify_policy_change(struct selinux_state *state,
2198                                         u32 seqno)
2199 {
2200         /* Flush external caches and notify userspace of policy load */
2201         avc_ss_reset(state->avc, seqno);
2202         selnl_notify_policyload(seqno);
2203         selinux_status_update_policyload(state, seqno);
2204         selinux_netlbl_cache_invalidate();
2205         selinux_xfrm_notify_policyload();
2206         selinux_ima_measure_state_locked(state);
2207 }
2208
2209 void selinux_policy_commit(struct selinux_state *state,
2210                            struct selinux_load_state *load_state)
2211 {
2212         struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2213         unsigned long flags;
2214         u32 seqno;
2215
2216         oldpolicy = rcu_dereference_protected(state->policy,
2217                                         lockdep_is_held(&state->policy_mutex));
2218
2219         /* If switching between different policy types, log MLS status */
2220         if (oldpolicy) {
2221                 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2222                         pr_info("SELinux: Disabling MLS support...\n");
2223                 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2224                         pr_info("SELinux: Enabling MLS support...\n");
2225         }
2226
2227         /* Set latest granting seqno for new policy. */
2228         if (oldpolicy)
2229                 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2230         else
2231                 newpolicy->latest_granting = 1;
2232         seqno = newpolicy->latest_granting;
2233
2234         /* Install the new policy. */
2235         if (oldpolicy) {
2236                 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2237                 rcu_assign_pointer(state->policy, newpolicy);
2238                 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2239         } else {
2240                 rcu_assign_pointer(state->policy, newpolicy);
2241         }
2242
2243         /* Load the policycaps from the new policy */
2244         security_load_policycaps(state, newpolicy);
2245
2246         if (!selinux_initialized(state)) {
2247                 /*
2248                  * After first policy load, the security server is
2249                  * marked as initialized and ready to handle requests and
2250                  * any objects created prior to policy load are then labeled.
2251                  */
2252                 selinux_mark_initialized(state);
2253                 selinux_complete_init();
2254         }
2255
2256         /* Free the old policy */
2257         synchronize_rcu();
2258         selinux_policy_free(oldpolicy);
2259         kfree(load_state->convert_data);
2260
2261         /* Notify others of the policy change */
2262         selinux_notify_policy_change(state, seqno);
2263 }
2264
2265 /**
2266  * security_load_policy - Load a security policy configuration.
2267  * @state: SELinux state
2268  * @data: binary policy data
2269  * @len: length of data in bytes
2270  * @load_state: policy load state
2271  *
2272  * Load a new set of security policy configuration data,
2273  * validate it and convert the SID table as necessary.
2274  * This function will flush the access vector cache after
2275  * loading the new policy.
2276  */
2277 int security_load_policy(struct selinux_state *state, void *data, size_t len,
2278                          struct selinux_load_state *load_state)
2279 {
2280         struct selinux_policy *newpolicy, *oldpolicy;
2281         struct selinux_policy_convert_data *convert_data;
2282         int rc = 0;
2283         struct policy_file file = { data, len }, *fp = &file;
2284
2285         newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2286         if (!newpolicy)
2287                 return -ENOMEM;
2288
2289         newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2290         if (!newpolicy->sidtab) {
2291                 rc = -ENOMEM;
2292                 goto err_policy;
2293         }
2294
2295         rc = policydb_read(&newpolicy->policydb, fp);
2296         if (rc)
2297                 goto err_sidtab;
2298
2299         newpolicy->policydb.len = len;
2300         rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2301                                 &newpolicy->map);
2302         if (rc)
2303                 goto err_policydb;
2304
2305         rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2306         if (rc) {
2307                 pr_err("SELinux:  unable to load the initial SIDs\n");
2308                 goto err_mapping;
2309         }
2310
2311         if (!selinux_initialized(state)) {
2312                 /* First policy load, so no need to preserve state from old policy */
2313                 load_state->policy = newpolicy;
2314                 load_state->convert_data = NULL;
2315                 return 0;
2316         }
2317
2318         oldpolicy = rcu_dereference_protected(state->policy,
2319                                         lockdep_is_held(&state->policy_mutex));
2320
2321         /* Preserve active boolean values from the old policy */
2322         rc = security_preserve_bools(oldpolicy, newpolicy);
2323         if (rc) {
2324                 pr_err("SELinux:  unable to preserve booleans\n");
2325                 goto err_free_isids;
2326         }
2327
2328         /*
2329          * Convert the internal representations of contexts
2330          * in the new SID table.
2331          */
2332
2333         convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2334         if (!convert_data) {
2335                 rc = -ENOMEM;
2336                 goto err_free_isids;
2337         }
2338
2339         convert_data->args.state = state;
2340         convert_data->args.oldp = &oldpolicy->policydb;
2341         convert_data->args.newp = &newpolicy->policydb;
2342
2343         convert_data->sidtab_params.args = &convert_data->args;
2344         convert_data->sidtab_params.target = newpolicy->sidtab;
2345
2346         rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2347         if (rc) {
2348                 pr_err("SELinux:  unable to convert the internal"
2349                         " representation of contexts in the new SID"
2350                         " table\n");
2351                 goto err_free_convert_data;
2352         }
2353
2354         load_state->policy = newpolicy;
2355         load_state->convert_data = convert_data;
2356         return 0;
2357
2358 err_free_convert_data:
2359         kfree(convert_data);
2360 err_free_isids:
2361         sidtab_destroy(newpolicy->sidtab);
2362 err_mapping:
2363         kfree(newpolicy->map.mapping);
2364 err_policydb:
2365         policydb_destroy(&newpolicy->policydb);
2366 err_sidtab:
2367         kfree(newpolicy->sidtab);
2368 err_policy:
2369         kfree(newpolicy);
2370
2371         return rc;
2372 }
2373
2374 /**
2375  * ocontext_to_sid - Helper to safely get sid for an ocontext
2376  * @sidtab: SID table
2377  * @c: ocontext structure
2378  * @index: index of the context entry (0 or 1)
2379  * @out_sid: pointer to the resulting SID value
2380  *
2381  * For all ocontexts except OCON_ISID the SID fields are populated
2382  * on-demand when needed. Since updating the SID value is an SMP-sensitive
2383  * operation, this helper must be used to do that safely.
2384  *
2385  * WARNING: This function may return -ESTALE, indicating that the caller
2386  * must retry the operation after re-acquiring the policy pointer!
2387  */
2388 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2389                            size_t index, u32 *out_sid)
2390 {
2391         int rc;
2392         u32 sid;
2393
2394         /* Ensure the associated sidtab entry is visible to this thread. */
2395         sid = smp_load_acquire(&c->sid[index]);
2396         if (!sid) {
2397                 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2398                 if (rc)
2399                         return rc;
2400
2401                 /*
2402                  * Ensure the new sidtab entry is visible to other threads
2403                  * when they see the SID.
2404                  */
2405                 smp_store_release(&c->sid[index], sid);
2406         }
2407         *out_sid = sid;
2408         return 0;
2409 }
2410
2411 /**
2412  * security_port_sid - Obtain the SID for a port.
2413  * @state: SELinux state
2414  * @protocol: protocol number
2415  * @port: port number
2416  * @out_sid: security identifier
2417  */
2418 int security_port_sid(struct selinux_state *state,
2419                       u8 protocol, u16 port, u32 *out_sid)
2420 {
2421         struct selinux_policy *policy;
2422         struct policydb *policydb;
2423         struct sidtab *sidtab;
2424         struct ocontext *c;
2425         int rc;
2426
2427         if (!selinux_initialized(state)) {
2428                 *out_sid = SECINITSID_PORT;
2429                 return 0;
2430         }
2431
2432 retry:
2433         rc = 0;
2434         rcu_read_lock();
2435         policy = rcu_dereference(state->policy);
2436         policydb = &policy->policydb;
2437         sidtab = policy->sidtab;
2438
2439         c = policydb->ocontexts[OCON_PORT];
2440         while (c) {
2441                 if (c->u.port.protocol == protocol &&
2442                     c->u.port.low_port <= port &&
2443                     c->u.port.high_port >= port)
2444                         break;
2445                 c = c->next;
2446         }
2447
2448         if (c) {
2449                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2450                 if (rc == -ESTALE) {
2451                         rcu_read_unlock();
2452                         goto retry;
2453                 }
2454                 if (rc)
2455                         goto out;
2456         } else {
2457                 *out_sid = SECINITSID_PORT;
2458         }
2459
2460 out:
2461         rcu_read_unlock();
2462         return rc;
2463 }
2464
2465 /**
2466  * security_ib_pkey_sid - Obtain the SID for a pkey.
2467  * @state: SELinux state
2468  * @subnet_prefix: Subnet Prefix
2469  * @pkey_num: pkey number
2470  * @out_sid: security identifier
2471  */
2472 int security_ib_pkey_sid(struct selinux_state *state,
2473                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2474 {
2475         struct selinux_policy *policy;
2476         struct policydb *policydb;
2477         struct sidtab *sidtab;
2478         struct ocontext *c;
2479         int rc;
2480
2481         if (!selinux_initialized(state)) {
2482                 *out_sid = SECINITSID_UNLABELED;
2483                 return 0;
2484         }
2485
2486 retry:
2487         rc = 0;
2488         rcu_read_lock();
2489         policy = rcu_dereference(state->policy);
2490         policydb = &policy->policydb;
2491         sidtab = policy->sidtab;
2492
2493         c = policydb->ocontexts[OCON_IBPKEY];
2494         while (c) {
2495                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2496                     c->u.ibpkey.high_pkey >= pkey_num &&
2497                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2498                         break;
2499
2500                 c = c->next;
2501         }
2502
2503         if (c) {
2504                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2505                 if (rc == -ESTALE) {
2506                         rcu_read_unlock();
2507                         goto retry;
2508                 }
2509                 if (rc)
2510                         goto out;
2511         } else
2512                 *out_sid = SECINITSID_UNLABELED;
2513
2514 out:
2515         rcu_read_unlock();
2516         return rc;
2517 }
2518
2519 /**
2520  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2521  * @state: SELinux state
2522  * @dev_name: device name
2523  * @port_num: port number
2524  * @out_sid: security identifier
2525  */
2526 int security_ib_endport_sid(struct selinux_state *state,
2527                             const char *dev_name, u8 port_num, u32 *out_sid)
2528 {
2529         struct selinux_policy *policy;
2530         struct policydb *policydb;
2531         struct sidtab *sidtab;
2532         struct ocontext *c;
2533         int rc;
2534
2535         if (!selinux_initialized(state)) {
2536                 *out_sid = SECINITSID_UNLABELED;
2537                 return 0;
2538         }
2539
2540 retry:
2541         rc = 0;
2542         rcu_read_lock();
2543         policy = rcu_dereference(state->policy);
2544         policydb = &policy->policydb;
2545         sidtab = policy->sidtab;
2546
2547         c = policydb->ocontexts[OCON_IBENDPORT];
2548         while (c) {
2549                 if (c->u.ibendport.port == port_num &&
2550                     !strncmp(c->u.ibendport.dev_name,
2551                              dev_name,
2552                              IB_DEVICE_NAME_MAX))
2553                         break;
2554
2555                 c = c->next;
2556         }
2557
2558         if (c) {
2559                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2560                 if (rc == -ESTALE) {
2561                         rcu_read_unlock();
2562                         goto retry;
2563                 }
2564                 if (rc)
2565                         goto out;
2566         } else
2567                 *out_sid = SECINITSID_UNLABELED;
2568
2569 out:
2570         rcu_read_unlock();
2571         return rc;
2572 }
2573
2574 /**
2575  * security_netif_sid - Obtain the SID for a network interface.
2576  * @state: SELinux state
2577  * @name: interface name
2578  * @if_sid: interface SID
2579  */
2580 int security_netif_sid(struct selinux_state *state,
2581                        char *name, u32 *if_sid)
2582 {
2583         struct selinux_policy *policy;
2584         struct policydb *policydb;
2585         struct sidtab *sidtab;
2586         int rc;
2587         struct ocontext *c;
2588
2589         if (!selinux_initialized(state)) {
2590                 *if_sid = SECINITSID_NETIF;
2591                 return 0;
2592         }
2593
2594 retry:
2595         rc = 0;
2596         rcu_read_lock();
2597         policy = rcu_dereference(state->policy);
2598         policydb = &policy->policydb;
2599         sidtab = policy->sidtab;
2600
2601         c = policydb->ocontexts[OCON_NETIF];
2602         while (c) {
2603                 if (strcmp(name, c->u.name) == 0)
2604                         break;
2605                 c = c->next;
2606         }
2607
2608         if (c) {
2609                 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2610                 if (rc == -ESTALE) {
2611                         rcu_read_unlock();
2612                         goto retry;
2613                 }
2614                 if (rc)
2615                         goto out;
2616         } else
2617                 *if_sid = SECINITSID_NETIF;
2618
2619 out:
2620         rcu_read_unlock();
2621         return rc;
2622 }
2623
2624 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2625 {
2626         int i, fail = 0;
2627
2628         for (i = 0; i < 4; i++)
2629                 if (addr[i] != (input[i] & mask[i])) {
2630                         fail = 1;
2631                         break;
2632                 }
2633
2634         return !fail;
2635 }
2636
2637 /**
2638  * security_node_sid - Obtain the SID for a node (host).
2639  * @state: SELinux state
2640  * @domain: communication domain aka address family
2641  * @addrp: address
2642  * @addrlen: address length in bytes
2643  * @out_sid: security identifier
2644  */
2645 int security_node_sid(struct selinux_state *state,
2646                       u16 domain,
2647                       void *addrp,
2648                       u32 addrlen,
2649                       u32 *out_sid)
2650 {
2651         struct selinux_policy *policy;
2652         struct policydb *policydb;
2653         struct sidtab *sidtab;
2654         int rc;
2655         struct ocontext *c;
2656
2657         if (!selinux_initialized(state)) {
2658                 *out_sid = SECINITSID_NODE;
2659                 return 0;
2660         }
2661
2662 retry:
2663         rcu_read_lock();
2664         policy = rcu_dereference(state->policy);
2665         policydb = &policy->policydb;
2666         sidtab = policy->sidtab;
2667
2668         switch (domain) {
2669         case AF_INET: {
2670                 u32 addr;
2671
2672                 rc = -EINVAL;
2673                 if (addrlen != sizeof(u32))
2674                         goto out;
2675
2676                 addr = *((u32 *)addrp);
2677
2678                 c = policydb->ocontexts[OCON_NODE];
2679                 while (c) {
2680                         if (c->u.node.addr == (addr & c->u.node.mask))
2681                                 break;
2682                         c = c->next;
2683                 }
2684                 break;
2685         }
2686
2687         case AF_INET6:
2688                 rc = -EINVAL;
2689                 if (addrlen != sizeof(u64) * 2)
2690                         goto out;
2691                 c = policydb->ocontexts[OCON_NODE6];
2692                 while (c) {
2693                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2694                                                 c->u.node6.mask))
2695                                 break;
2696                         c = c->next;
2697                 }
2698                 break;
2699
2700         default:
2701                 rc = 0;
2702                 *out_sid = SECINITSID_NODE;
2703                 goto out;
2704         }
2705
2706         if (c) {
2707                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2708                 if (rc == -ESTALE) {
2709                         rcu_read_unlock();
2710                         goto retry;
2711                 }
2712                 if (rc)
2713                         goto out;
2714         } else {
2715                 *out_sid = SECINITSID_NODE;
2716         }
2717
2718         rc = 0;
2719 out:
2720         rcu_read_unlock();
2721         return rc;
2722 }
2723
2724 #define SIDS_NEL 25
2725
2726 /**
2727  * security_get_user_sids - Obtain reachable SIDs for a user.
2728  * @state: SELinux state
2729  * @fromsid: starting SID
2730  * @username: username
2731  * @sids: array of reachable SIDs for user
2732  * @nel: number of elements in @sids
2733  *
2734  * Generate the set of SIDs for legal security contexts
2735  * for a given user that can be reached by @fromsid.
2736  * Set *@sids to point to a dynamically allocated
2737  * array containing the set of SIDs.  Set *@nel to the
2738  * number of elements in the array.
2739  */
2740
2741 int security_get_user_sids(struct selinux_state *state,
2742                            u32 fromsid,
2743                            char *username,
2744                            u32 **sids,
2745                            u32 *nel)
2746 {
2747         struct selinux_policy *policy;
2748         struct policydb *policydb;
2749         struct sidtab *sidtab;
2750         struct context *fromcon, usercon;
2751         u32 *mysids = NULL, *mysids2, sid;
2752         u32 i, j, mynel, maxnel = SIDS_NEL;
2753         struct user_datum *user;
2754         struct role_datum *role;
2755         struct ebitmap_node *rnode, *tnode;
2756         int rc;
2757
2758         *sids = NULL;
2759         *nel = 0;
2760
2761         if (!selinux_initialized(state))
2762                 return 0;
2763
2764         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2765         if (!mysids)
2766                 return -ENOMEM;
2767
2768 retry:
2769         mynel = 0;
2770         rcu_read_lock();
2771         policy = rcu_dereference(state->policy);
2772         policydb = &policy->policydb;
2773         sidtab = policy->sidtab;
2774
2775         context_init(&usercon);
2776
2777         rc = -EINVAL;
2778         fromcon = sidtab_search(sidtab, fromsid);
2779         if (!fromcon)
2780                 goto out_unlock;
2781
2782         rc = -EINVAL;
2783         user = symtab_search(&policydb->p_users, username);
2784         if (!user)
2785                 goto out_unlock;
2786
2787         usercon.user = user->value;
2788
2789         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2790                 role = policydb->role_val_to_struct[i];
2791                 usercon.role = i + 1;
2792                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2793                         usercon.type = j + 1;
2794
2795                         if (mls_setup_user_range(policydb, fromcon, user,
2796                                                  &usercon))
2797                                 continue;
2798
2799                         rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2800                         if (rc == -ESTALE) {
2801                                 rcu_read_unlock();
2802                                 goto retry;
2803                         }
2804                         if (rc)
2805                                 goto out_unlock;
2806                         if (mynel < maxnel) {
2807                                 mysids[mynel++] = sid;
2808                         } else {
2809                                 rc = -ENOMEM;
2810                                 maxnel += SIDS_NEL;
2811                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2812                                 if (!mysids2)
2813                                         goto out_unlock;
2814                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2815                                 kfree(mysids);
2816                                 mysids = mysids2;
2817                                 mysids[mynel++] = sid;
2818                         }
2819                 }
2820         }
2821         rc = 0;
2822 out_unlock:
2823         rcu_read_unlock();
2824         if (rc || !mynel) {
2825                 kfree(mysids);
2826                 return rc;
2827         }
2828
2829         rc = -ENOMEM;
2830         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2831         if (!mysids2) {
2832                 kfree(mysids);
2833                 return rc;
2834         }
2835         for (i = 0, j = 0; i < mynel; i++) {
2836                 struct av_decision dummy_avd;
2837                 rc = avc_has_perm_noaudit(state,
2838                                           fromsid, mysids[i],
2839                                           SECCLASS_PROCESS, /* kernel value */
2840                                           PROCESS__TRANSITION, AVC_STRICT,
2841                                           &dummy_avd);
2842                 if (!rc)
2843                         mysids2[j++] = mysids[i];
2844                 cond_resched();
2845         }
2846         kfree(mysids);
2847         *sids = mysids2;
2848         *nel = j;
2849         return 0;
2850 }
2851
2852 /**
2853  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2854  * @policy: policy
2855  * @fstype: filesystem type
2856  * @path: path from root of mount
2857  * @orig_sclass: file security class
2858  * @sid: SID for path
2859  *
2860  * Obtain a SID to use for a file in a filesystem that
2861  * cannot support xattr or use a fixed labeling behavior like
2862  * transition SIDs or task SIDs.
2863  *
2864  * WARNING: This function may return -ESTALE, indicating that the caller
2865  * must retry the operation after re-acquiring the policy pointer!
2866  */
2867 static inline int __security_genfs_sid(struct selinux_policy *policy,
2868                                        const char *fstype,
2869                                        const char *path,
2870                                        u16 orig_sclass,
2871                                        u32 *sid)
2872 {
2873         struct policydb *policydb = &policy->policydb;
2874         struct sidtab *sidtab = policy->sidtab;
2875         int len;
2876         u16 sclass;
2877         struct genfs *genfs;
2878         struct ocontext *c;
2879         int cmp = 0;
2880
2881         while (path[0] == '/' && path[1] == '/')
2882                 path++;
2883
2884         sclass = unmap_class(&policy->map, orig_sclass);
2885         *sid = SECINITSID_UNLABELED;
2886
2887         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2888                 cmp = strcmp(fstype, genfs->fstype);
2889                 if (cmp <= 0)
2890                         break;
2891         }
2892
2893         if (!genfs || cmp)
2894                 return -ENOENT;
2895
2896         for (c = genfs->head; c; c = c->next) {
2897                 len = strlen(c->u.name);
2898                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2899                     (strncmp(c->u.name, path, len) == 0))
2900                         break;
2901         }
2902
2903         if (!c)
2904                 return -ENOENT;
2905
2906         return ocontext_to_sid(sidtab, c, 0, sid);
2907 }
2908
2909 /**
2910  * security_genfs_sid - Obtain a SID for a file in a filesystem
2911  * @state: SELinux state
2912  * @fstype: filesystem type
2913  * @path: path from root of mount
2914  * @orig_sclass: file security class
2915  * @sid: SID for path
2916  *
2917  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2918  * it afterward.
2919  */
2920 int security_genfs_sid(struct selinux_state *state,
2921                        const char *fstype,
2922                        const char *path,
2923                        u16 orig_sclass,
2924                        u32 *sid)
2925 {
2926         struct selinux_policy *policy;
2927         int retval;
2928
2929         if (!selinux_initialized(state)) {
2930                 *sid = SECINITSID_UNLABELED;
2931                 return 0;
2932         }
2933
2934         do {
2935                 rcu_read_lock();
2936                 policy = rcu_dereference(state->policy);
2937                 retval = __security_genfs_sid(policy, fstype, path,
2938                                               orig_sclass, sid);
2939                 rcu_read_unlock();
2940         } while (retval == -ESTALE);
2941         return retval;
2942 }
2943
2944 int selinux_policy_genfs_sid(struct selinux_policy *policy,
2945                         const char *fstype,
2946                         const char *path,
2947                         u16 orig_sclass,
2948                         u32 *sid)
2949 {
2950         /* no lock required, policy is not yet accessible by other threads */
2951         return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2952 }
2953
2954 /**
2955  * security_fs_use - Determine how to handle labeling for a filesystem.
2956  * @state: SELinux state
2957  * @sb: superblock in question
2958  */
2959 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2960 {
2961         struct selinux_policy *policy;
2962         struct policydb *policydb;
2963         struct sidtab *sidtab;
2964         int rc;
2965         struct ocontext *c;
2966         struct superblock_security_struct *sbsec = selinux_superblock(sb);
2967         const char *fstype = sb->s_type->name;
2968
2969         if (!selinux_initialized(state)) {
2970                 sbsec->behavior = SECURITY_FS_USE_NONE;
2971                 sbsec->sid = SECINITSID_UNLABELED;
2972                 return 0;
2973         }
2974
2975 retry:
2976         rcu_read_lock();
2977         policy = rcu_dereference(state->policy);
2978         policydb = &policy->policydb;
2979         sidtab = policy->sidtab;
2980
2981         c = policydb->ocontexts[OCON_FSUSE];
2982         while (c) {
2983                 if (strcmp(fstype, c->u.name) == 0)
2984                         break;
2985                 c = c->next;
2986         }
2987
2988         if (c) {
2989                 sbsec->behavior = c->v.behavior;
2990                 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2991                 if (rc == -ESTALE) {
2992                         rcu_read_unlock();
2993                         goto retry;
2994                 }
2995                 if (rc)
2996                         goto out;
2997         } else {
2998                 rc = __security_genfs_sid(policy, fstype, "/",
2999                                         SECCLASS_DIR, &sbsec->sid);
3000                 if (rc == -ESTALE) {
3001                         rcu_read_unlock();
3002                         goto retry;
3003                 }
3004                 if (rc) {
3005                         sbsec->behavior = SECURITY_FS_USE_NONE;
3006                         rc = 0;
3007                 } else {
3008                         sbsec->behavior = SECURITY_FS_USE_GENFS;
3009                 }
3010         }
3011
3012 out:
3013         rcu_read_unlock();
3014         return rc;
3015 }
3016
3017 int security_get_bools(struct selinux_policy *policy,
3018                        u32 *len, char ***names, int **values)
3019 {
3020         struct policydb *policydb;
3021         u32 i;
3022         int rc;
3023
3024         policydb = &policy->policydb;
3025
3026         *names = NULL;
3027         *values = NULL;
3028
3029         rc = 0;
3030         *len = policydb->p_bools.nprim;
3031         if (!*len)
3032                 goto out;
3033
3034         rc = -ENOMEM;
3035         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3036         if (!*names)
3037                 goto err;
3038
3039         rc = -ENOMEM;
3040         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3041         if (!*values)
3042                 goto err;
3043
3044         for (i = 0; i < *len; i++) {
3045                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3046
3047                 rc = -ENOMEM;
3048                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3049                                       GFP_ATOMIC);
3050                 if (!(*names)[i])
3051                         goto err;
3052         }
3053         rc = 0;
3054 out:
3055         return rc;
3056 err:
3057         if (*names) {
3058                 for (i = 0; i < *len; i++)
3059                         kfree((*names)[i]);
3060                 kfree(*names);
3061         }
3062         kfree(*values);
3063         *len = 0;
3064         *names = NULL;
3065         *values = NULL;
3066         goto out;
3067 }
3068
3069
3070 int security_set_bools(struct selinux_state *state, u32 len, int *values)
3071 {
3072         struct selinux_policy *newpolicy, *oldpolicy;
3073         int rc;
3074         u32 i, seqno = 0;
3075
3076         if (!selinux_initialized(state))
3077                 return -EINVAL;
3078
3079         oldpolicy = rcu_dereference_protected(state->policy,
3080                                         lockdep_is_held(&state->policy_mutex));
3081
3082         /* Consistency check on number of booleans, should never fail */
3083         if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3084                 return -EINVAL;
3085
3086         newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3087         if (!newpolicy)
3088                 return -ENOMEM;
3089
3090         /*
3091          * Deep copy only the parts of the policydb that might be
3092          * modified as a result of changing booleans.
3093          */
3094         rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3095         if (rc) {
3096                 kfree(newpolicy);
3097                 return -ENOMEM;
3098         }
3099
3100         /* Update the boolean states in the copy */
3101         for (i = 0; i < len; i++) {
3102                 int new_state = !!values[i];
3103                 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3104
3105                 if (new_state != old_state) {
3106                         audit_log(audit_context(), GFP_ATOMIC,
3107                                 AUDIT_MAC_CONFIG_CHANGE,
3108                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3109                                 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3110                                 new_state,
3111                                 old_state,
3112                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3113                                 audit_get_sessionid(current));
3114                         newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3115                 }
3116         }
3117
3118         /* Re-evaluate the conditional rules in the copy */
3119         evaluate_cond_nodes(&newpolicy->policydb);
3120
3121         /* Set latest granting seqno for new policy */
3122         newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3123         seqno = newpolicy->latest_granting;
3124
3125         /* Install the new policy */
3126         rcu_assign_pointer(state->policy, newpolicy);
3127
3128         /*
3129          * Free the conditional portions of the old policydb
3130          * that were copied for the new policy, and the oldpolicy
3131          * structure itself but not what it references.
3132          */
3133         synchronize_rcu();
3134         selinux_policy_cond_free(oldpolicy);
3135
3136         /* Notify others of the policy change */
3137         selinux_notify_policy_change(state, seqno);
3138         return 0;
3139 }
3140
3141 int security_get_bool_value(struct selinux_state *state,
3142                             u32 index)
3143 {
3144         struct selinux_policy *policy;
3145         struct policydb *policydb;
3146         int rc;
3147         u32 len;
3148
3149         if (!selinux_initialized(state))
3150                 return 0;
3151
3152         rcu_read_lock();
3153         policy = rcu_dereference(state->policy);
3154         policydb = &policy->policydb;
3155
3156         rc = -EFAULT;
3157         len = policydb->p_bools.nprim;
3158         if (index >= len)
3159                 goto out;
3160
3161         rc = policydb->bool_val_to_struct[index]->state;
3162 out:
3163         rcu_read_unlock();
3164         return rc;
3165 }
3166
3167 static int security_preserve_bools(struct selinux_policy *oldpolicy,
3168                                 struct selinux_policy *newpolicy)
3169 {
3170         int rc, *bvalues = NULL;
3171         char **bnames = NULL;
3172         struct cond_bool_datum *booldatum;
3173         u32 i, nbools = 0;
3174
3175         rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3176         if (rc)
3177                 goto out;
3178         for (i = 0; i < nbools; i++) {
3179                 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3180                                         bnames[i]);
3181                 if (booldatum)
3182                         booldatum->state = bvalues[i];
3183         }
3184         evaluate_cond_nodes(&newpolicy->policydb);
3185
3186 out:
3187         if (bnames) {
3188                 for (i = 0; i < nbools; i++)
3189                         kfree(bnames[i]);
3190         }
3191         kfree(bnames);
3192         kfree(bvalues);
3193         return rc;
3194 }
3195
3196 /*
3197  * security_sid_mls_copy() - computes a new sid based on the given
3198  * sid and the mls portion of mls_sid.
3199  */
3200 int security_sid_mls_copy(struct selinux_state *state,
3201                           u32 sid, u32 mls_sid, u32 *new_sid)
3202 {
3203         struct selinux_policy *policy;
3204         struct policydb *policydb;
3205         struct sidtab *sidtab;
3206         struct context *context1;
3207         struct context *context2;
3208         struct context newcon;
3209         char *s;
3210         u32 len;
3211         int rc;
3212
3213         if (!selinux_initialized(state)) {
3214                 *new_sid = sid;
3215                 return 0;
3216         }
3217
3218 retry:
3219         rc = 0;
3220         context_init(&newcon);
3221
3222         rcu_read_lock();
3223         policy = rcu_dereference(state->policy);
3224         policydb = &policy->policydb;
3225         sidtab = policy->sidtab;
3226
3227         if (!policydb->mls_enabled) {
3228                 *new_sid = sid;
3229                 goto out_unlock;
3230         }
3231
3232         rc = -EINVAL;
3233         context1 = sidtab_search(sidtab, sid);
3234         if (!context1) {
3235                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3236                         __func__, sid);
3237                 goto out_unlock;
3238         }
3239
3240         rc = -EINVAL;
3241         context2 = sidtab_search(sidtab, mls_sid);
3242         if (!context2) {
3243                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3244                         __func__, mls_sid);
3245                 goto out_unlock;
3246         }
3247
3248         newcon.user = context1->user;
3249         newcon.role = context1->role;
3250         newcon.type = context1->type;
3251         rc = mls_context_cpy(&newcon, context2);
3252         if (rc)
3253                 goto out_unlock;
3254
3255         /* Check the validity of the new context. */
3256         if (!policydb_context_isvalid(policydb, &newcon)) {
3257                 rc = convert_context_handle_invalid_context(state, policydb,
3258                                                         &newcon);
3259                 if (rc) {
3260                         if (!context_struct_to_string(policydb, &newcon, &s,
3261                                                       &len)) {
3262                                 struct audit_buffer *ab;
3263
3264                                 ab = audit_log_start(audit_context(),
3265                                                      GFP_ATOMIC,
3266                                                      AUDIT_SELINUX_ERR);
3267                                 audit_log_format(ab,
3268                                                  "op=security_sid_mls_copy invalid_context=");
3269                                 /* don't record NUL with untrusted strings */
3270                                 audit_log_n_untrustedstring(ab, s, len - 1);
3271                                 audit_log_end(ab);
3272                                 kfree(s);
3273                         }
3274                         goto out_unlock;
3275                 }
3276         }
3277         rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3278         if (rc == -ESTALE) {
3279                 rcu_read_unlock();
3280                 context_destroy(&newcon);
3281                 goto retry;
3282         }
3283 out_unlock:
3284         rcu_read_unlock();
3285         context_destroy(&newcon);
3286         return rc;
3287 }
3288
3289 /**
3290  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3291  * @state: SELinux state
3292  * @nlbl_sid: NetLabel SID
3293  * @nlbl_type: NetLabel labeling protocol type
3294  * @xfrm_sid: XFRM SID
3295  * @peer_sid: network peer sid
3296  *
3297  * Description:
3298  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3299  * resolved into a single SID it is returned via @peer_sid and the function
3300  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3301  * returns a negative value.  A table summarizing the behavior is below:
3302  *
3303  *                                 | function return |      @sid
3304  *   ------------------------------+-----------------+-----------------
3305  *   no peer labels                |        0        |    SECSID_NULL
3306  *   single peer label             |        0        |    <peer_label>
3307  *   multiple, consistent labels   |        0        |    <peer_label>
3308  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3309  *
3310  */
3311 int security_net_peersid_resolve(struct selinux_state *state,
3312                                  u32 nlbl_sid, u32 nlbl_type,
3313                                  u32 xfrm_sid,
3314                                  u32 *peer_sid)
3315 {
3316         struct selinux_policy *policy;
3317         struct policydb *policydb;
3318         struct sidtab *sidtab;
3319         int rc;
3320         struct context *nlbl_ctx;
3321         struct context *xfrm_ctx;
3322
3323         *peer_sid = SECSID_NULL;
3324
3325         /* handle the common (which also happens to be the set of easy) cases
3326          * right away, these two if statements catch everything involving a
3327          * single or absent peer SID/label */
3328         if (xfrm_sid == SECSID_NULL) {
3329                 *peer_sid = nlbl_sid;
3330                 return 0;
3331         }
3332         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3333          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3334          * is present */
3335         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3336                 *peer_sid = xfrm_sid;
3337                 return 0;
3338         }
3339
3340         if (!selinux_initialized(state))
3341                 return 0;
3342
3343         rcu_read_lock();
3344         policy = rcu_dereference(state->policy);
3345         policydb = &policy->policydb;
3346         sidtab = policy->sidtab;
3347
3348         /*
3349          * We don't need to check initialized here since the only way both
3350          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3351          * security server was initialized and state->initialized was true.
3352          */
3353         if (!policydb->mls_enabled) {
3354                 rc = 0;
3355                 goto out;
3356         }
3357
3358         rc = -EINVAL;
3359         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3360         if (!nlbl_ctx) {
3361                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3362                        __func__, nlbl_sid);
3363                 goto out;
3364         }
3365         rc = -EINVAL;
3366         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3367         if (!xfrm_ctx) {
3368                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3369                        __func__, xfrm_sid);
3370                 goto out;
3371         }
3372         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3373         if (rc)
3374                 goto out;
3375
3376         /* at present NetLabel SIDs/labels really only carry MLS
3377          * information so if the MLS portion of the NetLabel SID
3378          * matches the MLS portion of the labeled XFRM SID/label
3379          * then pass along the XFRM SID as it is the most
3380          * expressive */
3381         *peer_sid = xfrm_sid;
3382 out:
3383         rcu_read_unlock();
3384         return rc;
3385 }
3386
3387 static int get_classes_callback(void *k, void *d, void *args)
3388 {
3389         struct class_datum *datum = d;
3390         char *name = k, **classes = args;
3391         int value = datum->value - 1;
3392
3393         classes[value] = kstrdup(name, GFP_ATOMIC);
3394         if (!classes[value])
3395                 return -ENOMEM;
3396
3397         return 0;
3398 }
3399
3400 int security_get_classes(struct selinux_policy *policy,
3401                          char ***classes, int *nclasses)
3402 {
3403         struct policydb *policydb;
3404         int rc;
3405
3406         policydb = &policy->policydb;
3407
3408         rc = -ENOMEM;
3409         *nclasses = policydb->p_classes.nprim;
3410         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3411         if (!*classes)
3412                 goto out;
3413
3414         rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3415                          *classes);
3416         if (rc) {
3417                 int i;
3418                 for (i = 0; i < *nclasses; i++)
3419                         kfree((*classes)[i]);
3420                 kfree(*classes);
3421         }
3422
3423 out:
3424         return rc;
3425 }
3426
3427 static int get_permissions_callback(void *k, void *d, void *args)
3428 {
3429         struct perm_datum *datum = d;
3430         char *name = k, **perms = args;
3431         int value = datum->value - 1;
3432
3433         perms[value] = kstrdup(name, GFP_ATOMIC);
3434         if (!perms[value])
3435                 return -ENOMEM;
3436
3437         return 0;
3438 }
3439
3440 int security_get_permissions(struct selinux_policy *policy,
3441                              char *class, char ***perms, int *nperms)
3442 {
3443         struct policydb *policydb;
3444         int rc, i;
3445         struct class_datum *match;
3446
3447         policydb = &policy->policydb;
3448
3449         rc = -EINVAL;
3450         match = symtab_search(&policydb->p_classes, class);
3451         if (!match) {
3452                 pr_err("SELinux: %s:  unrecognized class %s\n",
3453                         __func__, class);
3454                 goto out;
3455         }
3456
3457         rc = -ENOMEM;
3458         *nperms = match->permissions.nprim;
3459         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3460         if (!*perms)
3461                 goto out;
3462
3463         if (match->comdatum) {
3464                 rc = hashtab_map(&match->comdatum->permissions.table,
3465                                  get_permissions_callback, *perms);
3466                 if (rc)
3467                         goto err;
3468         }
3469
3470         rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3471                          *perms);
3472         if (rc)
3473                 goto err;
3474
3475 out:
3476         return rc;
3477
3478 err:
3479         for (i = 0; i < *nperms; i++)
3480                 kfree((*perms)[i]);
3481         kfree(*perms);
3482         return rc;
3483 }
3484
3485 int security_get_reject_unknown(struct selinux_state *state)
3486 {
3487         struct selinux_policy *policy;
3488         int value;
3489
3490         if (!selinux_initialized(state))
3491                 return 0;
3492
3493         rcu_read_lock();
3494         policy = rcu_dereference(state->policy);
3495         value = policy->policydb.reject_unknown;
3496         rcu_read_unlock();
3497         return value;
3498 }
3499
3500 int security_get_allow_unknown(struct selinux_state *state)
3501 {
3502         struct selinux_policy *policy;
3503         int value;
3504
3505         if (!selinux_initialized(state))
3506                 return 0;
3507
3508         rcu_read_lock();
3509         policy = rcu_dereference(state->policy);
3510         value = policy->policydb.allow_unknown;
3511         rcu_read_unlock();
3512         return value;
3513 }
3514
3515 /**
3516  * security_policycap_supported - Check for a specific policy capability
3517  * @state: SELinux state
3518  * @req_cap: capability
3519  *
3520  * Description:
3521  * This function queries the currently loaded policy to see if it supports the
3522  * capability specified by @req_cap.  Returns true (1) if the capability is
3523  * supported, false (0) if it isn't supported.
3524  *
3525  */
3526 int security_policycap_supported(struct selinux_state *state,
3527                                  unsigned int req_cap)
3528 {
3529         struct selinux_policy *policy;
3530         int rc;
3531
3532         if (!selinux_initialized(state))
3533                 return 0;
3534
3535         rcu_read_lock();
3536         policy = rcu_dereference(state->policy);
3537         rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3538         rcu_read_unlock();
3539
3540         return rc;
3541 }
3542
3543 struct selinux_audit_rule {
3544         u32 au_seqno;
3545         struct context au_ctxt;
3546 };
3547
3548 void selinux_audit_rule_free(void *vrule)
3549 {
3550         struct selinux_audit_rule *rule = vrule;
3551
3552         if (rule) {
3553                 context_destroy(&rule->au_ctxt);
3554                 kfree(rule);
3555         }
3556 }
3557
3558 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3559 {
3560         struct selinux_state *state = &selinux_state;
3561         struct selinux_policy *policy;
3562         struct policydb *policydb;
3563         struct selinux_audit_rule *tmprule;
3564         struct role_datum *roledatum;
3565         struct type_datum *typedatum;
3566         struct user_datum *userdatum;
3567         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3568         int rc = 0;
3569
3570         *rule = NULL;
3571
3572         if (!selinux_initialized(state))
3573                 return -EOPNOTSUPP;
3574
3575         switch (field) {
3576         case AUDIT_SUBJ_USER:
3577         case AUDIT_SUBJ_ROLE:
3578         case AUDIT_SUBJ_TYPE:
3579         case AUDIT_OBJ_USER:
3580         case AUDIT_OBJ_ROLE:
3581         case AUDIT_OBJ_TYPE:
3582                 /* only 'equals' and 'not equals' fit user, role, and type */
3583                 if (op != Audit_equal && op != Audit_not_equal)
3584                         return -EINVAL;
3585                 break;
3586         case AUDIT_SUBJ_SEN:
3587         case AUDIT_SUBJ_CLR:
3588         case AUDIT_OBJ_LEV_LOW:
3589         case AUDIT_OBJ_LEV_HIGH:
3590                 /* we do not allow a range, indicated by the presence of '-' */
3591                 if (strchr(rulestr, '-'))
3592                         return -EINVAL;
3593                 break;
3594         default:
3595                 /* only the above fields are valid */
3596                 return -EINVAL;
3597         }
3598
3599         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3600         if (!tmprule)
3601                 return -ENOMEM;
3602
3603         context_init(&tmprule->au_ctxt);
3604
3605         rcu_read_lock();
3606         policy = rcu_dereference(state->policy);
3607         policydb = &policy->policydb;
3608
3609         tmprule->au_seqno = policy->latest_granting;
3610
3611         switch (field) {
3612         case AUDIT_SUBJ_USER:
3613         case AUDIT_OBJ_USER:
3614                 rc = -EINVAL;
3615                 userdatum = symtab_search(&policydb->p_users, rulestr);
3616                 if (!userdatum)
3617                         goto out;
3618                 tmprule->au_ctxt.user = userdatum->value;
3619                 break;
3620         case AUDIT_SUBJ_ROLE:
3621         case AUDIT_OBJ_ROLE:
3622                 rc = -EINVAL;
3623                 roledatum = symtab_search(&policydb->p_roles, rulestr);
3624                 if (!roledatum)
3625                         goto out;
3626                 tmprule->au_ctxt.role = roledatum->value;
3627                 break;
3628         case AUDIT_SUBJ_TYPE:
3629         case AUDIT_OBJ_TYPE:
3630                 rc = -EINVAL;
3631                 typedatum = symtab_search(&policydb->p_types, rulestr);
3632                 if (!typedatum)
3633                         goto out;
3634                 tmprule->au_ctxt.type = typedatum->value;
3635                 break;
3636         case AUDIT_SUBJ_SEN:
3637         case AUDIT_SUBJ_CLR:
3638         case AUDIT_OBJ_LEV_LOW:
3639         case AUDIT_OBJ_LEV_HIGH:
3640                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3641                                      GFP_ATOMIC);
3642                 if (rc)
3643                         goto out;
3644                 break;
3645         }
3646         rc = 0;
3647 out:
3648         rcu_read_unlock();
3649
3650         if (rc) {
3651                 selinux_audit_rule_free(tmprule);
3652                 tmprule = NULL;
3653         }
3654
3655         *rule = tmprule;
3656
3657         return rc;
3658 }
3659
3660 /* Check to see if the rule contains any selinux fields */
3661 int selinux_audit_rule_known(struct audit_krule *rule)
3662 {
3663         int i;
3664
3665         for (i = 0; i < rule->field_count; i++) {
3666                 struct audit_field *f = &rule->fields[i];
3667                 switch (f->type) {
3668                 case AUDIT_SUBJ_USER:
3669                 case AUDIT_SUBJ_ROLE:
3670                 case AUDIT_SUBJ_TYPE:
3671                 case AUDIT_SUBJ_SEN:
3672                 case AUDIT_SUBJ_CLR:
3673                 case AUDIT_OBJ_USER:
3674                 case AUDIT_OBJ_ROLE:
3675                 case AUDIT_OBJ_TYPE:
3676                 case AUDIT_OBJ_LEV_LOW:
3677                 case AUDIT_OBJ_LEV_HIGH:
3678                         return 1;
3679                 }
3680         }
3681
3682         return 0;
3683 }
3684
3685 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3686 {
3687         struct selinux_state *state = &selinux_state;
3688         struct selinux_policy *policy;
3689         struct context *ctxt;
3690         struct mls_level *level;
3691         struct selinux_audit_rule *rule = vrule;
3692         int match = 0;
3693
3694         if (unlikely(!rule)) {
3695                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3696                 return -ENOENT;
3697         }
3698
3699         if (!selinux_initialized(state))
3700                 return 0;
3701
3702         rcu_read_lock();
3703
3704         policy = rcu_dereference(state->policy);
3705
3706         if (rule->au_seqno < policy->latest_granting) {
3707                 match = -ESTALE;
3708                 goto out;
3709         }
3710
3711         ctxt = sidtab_search(policy->sidtab, sid);
3712         if (unlikely(!ctxt)) {
3713                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3714                           sid);
3715                 match = -ENOENT;
3716                 goto out;
3717         }
3718
3719         /* a field/op pair that is not caught here will simply fall through
3720            without a match */
3721         switch (field) {
3722         case AUDIT_SUBJ_USER:
3723         case AUDIT_OBJ_USER:
3724                 switch (op) {
3725                 case Audit_equal:
3726                         match = (ctxt->user == rule->au_ctxt.user);
3727                         break;
3728                 case Audit_not_equal:
3729                         match = (ctxt->user != rule->au_ctxt.user);
3730                         break;
3731                 }
3732                 break;
3733         case AUDIT_SUBJ_ROLE:
3734         case AUDIT_OBJ_ROLE:
3735                 switch (op) {
3736                 case Audit_equal:
3737                         match = (ctxt->role == rule->au_ctxt.role);
3738                         break;
3739                 case Audit_not_equal:
3740                         match = (ctxt->role != rule->au_ctxt.role);
3741                         break;
3742                 }
3743                 break;
3744         case AUDIT_SUBJ_TYPE:
3745         case AUDIT_OBJ_TYPE:
3746                 switch (op) {
3747                 case Audit_equal:
3748                         match = (ctxt->type == rule->au_ctxt.type);
3749                         break;
3750                 case Audit_not_equal:
3751                         match = (ctxt->type != rule->au_ctxt.type);
3752                         break;
3753                 }
3754                 break;
3755         case AUDIT_SUBJ_SEN:
3756         case AUDIT_SUBJ_CLR:
3757         case AUDIT_OBJ_LEV_LOW:
3758         case AUDIT_OBJ_LEV_HIGH:
3759                 level = ((field == AUDIT_SUBJ_SEN ||
3760                           field == AUDIT_OBJ_LEV_LOW) ?
3761                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3762                 switch (op) {
3763                 case Audit_equal:
3764                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3765                                              level);
3766                         break;
3767                 case Audit_not_equal:
3768                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3769                                               level);
3770                         break;
3771                 case Audit_lt:
3772                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3773                                                level) &&
3774                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3775                                                level));
3776                         break;
3777                 case Audit_le:
3778                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3779                                               level);
3780                         break;
3781                 case Audit_gt:
3782                         match = (mls_level_dom(level,
3783                                               &rule->au_ctxt.range.level[0]) &&
3784                                  !mls_level_eq(level,
3785                                                &rule->au_ctxt.range.level[0]));
3786                         break;
3787                 case Audit_ge:
3788                         match = mls_level_dom(level,
3789                                               &rule->au_ctxt.range.level[0]);
3790                         break;
3791                 }
3792         }
3793
3794 out:
3795         rcu_read_unlock();
3796         return match;
3797 }
3798
3799 static int aurule_avc_callback(u32 event)
3800 {
3801         if (event == AVC_CALLBACK_RESET)
3802                 return audit_update_lsm_rules();
3803         return 0;
3804 }
3805
3806 static int __init aurule_init(void)
3807 {
3808         int err;
3809
3810         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3811         if (err)
3812                 panic("avc_add_callback() failed, error %d\n", err);
3813
3814         return err;
3815 }
3816 __initcall(aurule_init);
3817
3818 #ifdef CONFIG_NETLABEL
3819 /**
3820  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3821  * @secattr: the NetLabel packet security attributes
3822  * @sid: the SELinux SID
3823  *
3824  * Description:
3825  * Attempt to cache the context in @ctx, which was derived from the packet in
3826  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3827  * already been initialized.
3828  *
3829  */
3830 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3831                                       u32 sid)
3832 {
3833         u32 *sid_cache;
3834
3835         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3836         if (sid_cache == NULL)
3837                 return;
3838         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3839         if (secattr->cache == NULL) {
3840                 kfree(sid_cache);
3841                 return;
3842         }
3843
3844         *sid_cache = sid;
3845         secattr->cache->free = kfree;
3846         secattr->cache->data = sid_cache;
3847         secattr->flags |= NETLBL_SECATTR_CACHE;
3848 }
3849
3850 /**
3851  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3852  * @state: SELinux state
3853  * @secattr: the NetLabel packet security attributes
3854  * @sid: the SELinux SID
3855  *
3856  * Description:
3857  * Convert the given NetLabel security attributes in @secattr into a
3858  * SELinux SID.  If the @secattr field does not contain a full SELinux
3859  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3860  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3861  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3862  * conversion for future lookups.  Returns zero on success, negative values on
3863  * failure.
3864  *
3865  */
3866 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3867                                    struct netlbl_lsm_secattr *secattr,
3868                                    u32 *sid)
3869 {
3870         struct selinux_policy *policy;
3871         struct policydb *policydb;
3872         struct sidtab *sidtab;
3873         int rc;
3874         struct context *ctx;
3875         struct context ctx_new;
3876
3877         if (!selinux_initialized(state)) {
3878                 *sid = SECSID_NULL;
3879                 return 0;
3880         }
3881
3882 retry:
3883         rc = 0;
3884         rcu_read_lock();
3885         policy = rcu_dereference(state->policy);
3886         policydb = &policy->policydb;
3887         sidtab = policy->sidtab;
3888
3889         if (secattr->flags & NETLBL_SECATTR_CACHE)
3890                 *sid = *(u32 *)secattr->cache->data;
3891         else if (secattr->flags & NETLBL_SECATTR_SECID)
3892                 *sid = secattr->attr.secid;
3893         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3894                 rc = -EIDRM;
3895                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3896                 if (ctx == NULL)
3897                         goto out;
3898
3899                 context_init(&ctx_new);
3900                 ctx_new.user = ctx->user;
3901                 ctx_new.role = ctx->role;
3902                 ctx_new.type = ctx->type;
3903                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3904                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3905                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3906                         if (rc)
3907                                 goto out;
3908                 }
3909                 rc = -EIDRM;
3910                 if (!mls_context_isvalid(policydb, &ctx_new)) {
3911                         ebitmap_destroy(&ctx_new.range.level[0].cat);
3912                         goto out;
3913                 }
3914
3915                 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3916                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3917                 if (rc == -ESTALE) {
3918                         rcu_read_unlock();
3919                         goto retry;
3920                 }
3921                 if (rc)
3922                         goto out;
3923
3924                 security_netlbl_cache_add(secattr, *sid);
3925         } else
3926                 *sid = SECSID_NULL;
3927
3928 out:
3929         rcu_read_unlock();
3930         return rc;
3931 }
3932
3933 /**
3934  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3935  * @state: SELinux state
3936  * @sid: the SELinux SID
3937  * @secattr: the NetLabel packet security attributes
3938  *
3939  * Description:
3940  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3941  * Returns zero on success, negative values on failure.
3942  *
3943  */
3944 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3945                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3946 {
3947         struct selinux_policy *policy;
3948         struct policydb *policydb;
3949         int rc;
3950         struct context *ctx;
3951
3952         if (!selinux_initialized(state))
3953                 return 0;
3954
3955         rcu_read_lock();
3956         policy = rcu_dereference(state->policy);
3957         policydb = &policy->policydb;
3958
3959         rc = -ENOENT;
3960         ctx = sidtab_search(policy->sidtab, sid);
3961         if (ctx == NULL)
3962                 goto out;
3963
3964         rc = -ENOMEM;
3965         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3966                                   GFP_ATOMIC);
3967         if (secattr->domain == NULL)
3968                 goto out;
3969
3970         secattr->attr.secid = sid;
3971         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3972         mls_export_netlbl_lvl(policydb, ctx, secattr);
3973         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3974 out:
3975         rcu_read_unlock();
3976         return rc;
3977 }
3978 #endif /* CONFIG_NETLABEL */
3979
3980 /**
3981  * __security_read_policy - read the policy.
3982  * @policy: SELinux policy
3983  * @data: binary policy data
3984  * @len: length of data in bytes
3985  *
3986  */
3987 static int __security_read_policy(struct selinux_policy *policy,
3988                                   void *data, size_t *len)
3989 {
3990         int rc;
3991         struct policy_file fp;
3992
3993         fp.data = data;
3994         fp.len = *len;
3995
3996         rc = policydb_write(&policy->policydb, &fp);
3997         if (rc)
3998                 return rc;
3999
4000         *len = (unsigned long)fp.data - (unsigned long)data;
4001         return 0;
4002 }
4003
4004 /**
4005  * security_read_policy - read the policy.
4006  * @state: selinux_state
4007  * @data: binary policy data
4008  * @len: length of data in bytes
4009  *
4010  */
4011 int security_read_policy(struct selinux_state *state,
4012                          void **data, size_t *len)
4013 {
4014         struct selinux_policy *policy;
4015
4016         policy = rcu_dereference_protected(
4017                         state->policy, lockdep_is_held(&state->policy_mutex));
4018         if (!policy)
4019                 return -EINVAL;
4020
4021         *len = policy->policydb.len;
4022         *data = vmalloc_user(*len);
4023         if (!*data)
4024                 return -ENOMEM;
4025
4026         return __security_read_policy(policy, *data, len);
4027 }
4028
4029 /**
4030  * security_read_state_kernel - read the policy.
4031  * @state: selinux_state
4032  * @data: binary policy data
4033  * @len: length of data in bytes
4034  *
4035  * Allocates kernel memory for reading SELinux policy.
4036  * This function is for internal use only and should not
4037  * be used for returning data to user space.
4038  *
4039  * This function must be called with policy_mutex held.
4040  */
4041 int security_read_state_kernel(struct selinux_state *state,
4042                                void **data, size_t *len)
4043 {
4044         int err;
4045         struct selinux_policy *policy;
4046
4047         policy = rcu_dereference_protected(
4048                         state->policy, lockdep_is_held(&state->policy_mutex));
4049         if (!policy)
4050                 return -EINVAL;
4051
4052         *len = policy->policydb.len;
4053         *data = vmalloc(*len);
4054         if (!*data)
4055                 return -ENOMEM;
4056
4057         err = __security_read_policy(policy, *data, len);
4058         if (err) {
4059                 vfree(*data);
4060                 *data = NULL;
4061                 *len = 0;
4062         }
4063         return err;
4064 }