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 <net/netlabel.h>
  51
  52 #include "flask.h"
  53 #include "avc.h"
  54 #include "avc_ss.h"
  55 #include "security.h"
  56 #include "context.h"
  57 #include "policydb.h"
  58 #include "sidtab.h"
  59 #include "services.h"
  60 #include "conditional.h"
  61 #include "mls.h"
  62 #include "objsec.h"
  63 #include "netlabel.h"
  64 #include "xfrm.h"
  65 #include "ebitmap.h"
  66 #include "audit.h"
  67 #include "policycap_names.h"
  68
  69 struct convert_context_args {
  70         struct selinux_state *state;
  71         struct policydb *oldp;
  72         struct policydb *newp;
  73 };
  74
  75 struct selinux_policy_convert_data {
  76         struct convert_context_args args;
  77         struct sidtab_convert_params sidtab_params;
  78 };
  79
  80 /* Forward declaration. */
  81 static int context_struct_to_string(struct policydb *policydb,
  82                                     struct context *context,
  83                                     char **scontext,
  84                                     u32 *scontext_len);
  85
  86 static int sidtab_entry_to_string(struct policydb *policydb,
  87                                   struct sidtab *sidtab,
  88                                   struct sidtab_entry *entry,
  89                                   char **scontext,
  90                                   u32 *scontext_len);
  91
  92 static void context_struct_compute_av(struct policydb *policydb,
  93                                       struct context *scontext,
  94                                       struct context *tcontext,
  95                                       u16 tclass,
  96                                       struct av_decision *avd,
  97                                       struct extended_perms *xperms);
  98
  99 static int selinux_set_mapping(struct policydb *pol,
 100                                struct security_class_mapping *map,
 101                                struct selinux_map *out_map)
 102 {
 103         u16 i, j;
 104         unsigned k;
 105         bool print_unknown_handle = false;
 106
 107         /* Find number of classes in the input mapping */
 108         if (!map)
 109                 return -EINVAL;
 110         i = 0;
 111         while (map[i].name)
 112                 i++;
 113
 114         /* Allocate space for the class records, plus one for class zero */
 115         out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
 116         if (!out_map->mapping)
 117                 return -ENOMEM;
 118
 119         /* Store the raw class and permission values */
 120         j = 0;
 121         while (map[j].name) {
 122                 struct security_class_mapping *p_in = map + (j++);
 123                 struct selinux_mapping *p_out = out_map->mapping + j;
 124
 125                 /* An empty class string skips ahead */
 126                 if (!strcmp(p_in->name, "")) {
 127                         p_out->num_perms = 0;
 128                         continue;
 129                 }
 130
 131                 p_out->value = string_to_security_class(pol, p_in->name);
 132                 if (!p_out->value) {
 133                         pr_info("SELinux:  Class %s not defined in policy.\n",
 134                                p_in->name);
 135                         if (pol->reject_unknown)
 136                                 goto err;
 137                         p_out->num_perms = 0;
 138                         print_unknown_handle = true;
 139                         continue;
 140                 }
 141
 142                 k = 0;
 143                 while (p_in->perms[k]) {
 144                         /* An empty permission string skips ahead */
 145                         if (!*p_in->perms[k]) {
 146                                 k++;
 147                                 continue;
 148                         }
 149                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 150                                                             p_in->perms[k]);
 151                         if (!p_out->perms[k]) {
 152                                 pr_info("SELinux:  Permission %s in class %s not defined in policy.\n",
 153                                        p_in->perms[k], p_in->name);
 154                                 if (pol->reject_unknown)
 155                                         goto err;
 156                                 print_unknown_handle = true;
 157                         }
 158
 159                         k++;
 160                 }
 161                 p_out->num_perms = k;
 162         }
 163
 164         if (print_unknown_handle)
 165                 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
 166                        pol->allow_unknown ? "allowed" : "denied");
 167
 168         out_map->size = i;
 169         return 0;
 170 err:
 171         kfree(out_map->mapping);
 172         out_map->mapping = NULL;
 173         return -EINVAL;
 174 }
 175
 176 /*
 177  * Get real, policy values from mapped values
 178  */
 179
 180 static u16 unmap_class(struct selinux_map *map, u16 tclass)
 181 {
 182         if (tclass < map->size)
 183                 return map->mapping[tclass].value;
 184
 185         return tclass;
 186 }
 187
 188 /*
 189  * Get kernel value for class from its policy value
 190  */
 191 static u16 map_class(struct selinux_map *map, u16 pol_value)
 192 {
 193         u16 i;
 194
 195         for (i = 1; i < map->size; i++) {
 196                 if (map->mapping[i].value == pol_value)
 197                         return i;
 198         }
 199
 200         return SECCLASS_NULL;
 201 }
 202
 203 static void map_decision(struct selinux_map *map,
 204                          u16 tclass, struct av_decision *avd,
 205                          int allow_unknown)
 206 {
 207         if (tclass < map->size) {
 208                 struct selinux_mapping *mapping = &map->mapping[tclass];
 209                 unsigned int i, n = mapping->num_perms;
 210                 u32 result;
 211
 212                 for (i = 0, result = 0; i < n; i++) {
 213                         if (avd->allowed & mapping->perms[i])
 214                                 result |= 1<<i;
 215                         if (allow_unknown && !mapping->perms[i])
 216                                 result |= 1<<i;
 217                 }
 218                 avd->allowed = result;
 219
 220                 for (i = 0, result = 0; i < n; i++)
 221                         if (avd->auditallow & mapping->perms[i])
 222                                 result |= 1<<i;
 223                 avd->auditallow = result;
 224
 225                 for (i = 0, result = 0; i < n; i++) {
 226                         if (avd->auditdeny & mapping->perms[i])
 227                                 result |= 1<<i;
 228                         if (!allow_unknown && !mapping->perms[i])
 229                                 result |= 1<<i;
 230                 }
 231                 /*
 232                  * In case the kernel has a bug and requests a permission
 233                  * between num_perms and the maximum permission number, we
 234                  * should audit that denial
 235                  */
 236                 for (; i < (sizeof(u32)*8); i++)
 237                         result |= 1<<i;
 238                 avd->auditdeny = result;
 239         }
 240 }
 241
 242 int security_mls_enabled(struct selinux_state *state)
 243 {
 244         int mls_enabled;
 245         struct selinux_policy *policy;
 246
 247         if (!selinux_initialized(state))
 248                 return 0;
 249
 250         rcu_read_lock();
 251         policy = rcu_dereference(state->policy);
 252         mls_enabled = policy->policydb.mls_enabled;
 253         rcu_read_unlock();
 254         return mls_enabled;
 255 }
 256
 257 /*
 258  * Return the boolean value of a constraint expression
 259  * when it is applied to the specified source and target
 260  * security contexts.
 261  *
 262  * xcontext is a special beast...  It is used by the validatetrans rules
 263  * only.  For these rules, scontext is the context before the transition,
 264  * tcontext is the context after the transition, and xcontext is the context
 265  * of the process performing the transition.  All other callers of
 266  * constraint_expr_eval should pass in NULL for xcontext.
 267  */
 268 static int constraint_expr_eval(struct policydb *policydb,
 269                                 struct context *scontext,
 270                                 struct context *tcontext,
 271                                 struct context *xcontext,
 272                                 struct constraint_expr *cexpr)
 273 {
 274         u32 val1, val2;
 275         struct context *c;
 276         struct role_datum *r1, *r2;
 277         struct mls_level *l1, *l2;
 278         struct constraint_expr *e;
 279         int s[CEXPR_MAXDEPTH];
 280         int sp = -1;
 281
 282         for (e = cexpr; e; e = e->next) {
 283                 switch (e->expr_type) {
 284                 case CEXPR_NOT:
 285                         BUG_ON(sp < 0);
 286                         s[sp] = !s[sp];
 287                         break;
 288                 case CEXPR_AND:
 289                         BUG_ON(sp < 1);
 290                         sp--;
 291                         s[sp] &= s[sp + 1];
 292                         break;
 293                 case CEXPR_OR:
 294                         BUG_ON(sp < 1);
 295                         sp--;
 296                         s[sp] |= s[sp + 1];
 297                         break;
 298                 case CEXPR_ATTR:
 299                         if (sp == (CEXPR_MAXDEPTH - 1))
 300                                 return 0;
 301                         switch (e->attr) {
 302                         case CEXPR_USER:
 303                                 val1 = scontext->user;
 304                                 val2 = tcontext->user;
 305                                 break;
 306                         case CEXPR_TYPE:
 307                                 val1 = scontext->type;
 308                                 val2 = tcontext->type;
 309                                 break;
 310                         case CEXPR_ROLE:
 311                                 val1 = scontext->role;
 312                                 val2 = tcontext->role;
 313                                 r1 = policydb->role_val_to_struct[val1 - 1];
 314                                 r2 = policydb->role_val_to_struct[val2 - 1];
 315                                 switch (e->op) {
 316                                 case CEXPR_DOM:
 317                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 318                                                                   val2 - 1);
 319                                         continue;
 320                                 case CEXPR_DOMBY:
 321                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 322                                                                   val1 - 1);
 323                                         continue;
 324                                 case CEXPR_INCOMP:
 325                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 326                                                                     val2 - 1) &&
 327                                                    !ebitmap_get_bit(&r2->dominates,
 328                                                                     val1 - 1));
 329                                         continue;
 330                                 default:
 331                                         break;
 332                                 }
 333                                 break;
 334                         case CEXPR_L1L2:
 335                                 l1 = &(scontext->range.level[0]);
 336                                 l2 = &(tcontext->range.level[0]);
 337                                 goto mls_ops;
 338                         case CEXPR_L1H2:
 339                                 l1 = &(scontext->range.level[0]);
 340                                 l2 = &(tcontext->range.level[1]);
 341                                 goto mls_ops;
 342                         case CEXPR_H1L2:
 343                                 l1 = &(scontext->range.level[1]);
 344                                 l2 = &(tcontext->range.level[0]);
 345                                 goto mls_ops;
 346                         case CEXPR_H1H2:
 347                                 l1 = &(scontext->range.level[1]);
 348                                 l2 = &(tcontext->range.level[1]);
 349                                 goto mls_ops;
 350                         case CEXPR_L1H1:
 351                                 l1 = &(scontext->range.level[0]);
 352                                 l2 = &(scontext->range.level[1]);
 353                                 goto mls_ops;
 354                         case CEXPR_L2H2:
 355                                 l1 = &(tcontext->range.level[0]);
 356                                 l2 = &(tcontext->range.level[1]);
 357                                 goto mls_ops;
 358 mls_ops:
 359                         switch (e->op) {
 360                         case CEXPR_EQ:
 361                                 s[++sp] = mls_level_eq(l1, l2);
 362                                 continue;
 363                         case CEXPR_NEQ:
 364                                 s[++sp] = !mls_level_eq(l1, l2);
 365                                 continue;
 366                         case CEXPR_DOM:
 367                                 s[++sp] = mls_level_dom(l1, l2);
 368                                 continue;
 369                         case CEXPR_DOMBY:
 370                                 s[++sp] = mls_level_dom(l2, l1);
 371                                 continue;
 372                         case CEXPR_INCOMP:
 373                                 s[++sp] = mls_level_incomp(l2, l1);
 374                                 continue;
 375                         default:
 376                                 BUG();
 377                                 return 0;
 378                         }
 379                         break;
 380                         default:
 381                                 BUG();
 382                                 return 0;
 383                         }
 384
 385                         switch (e->op) {
 386                         case CEXPR_EQ:
 387                                 s[++sp] = (val1 == val2);
 388                                 break;
 389                         case CEXPR_NEQ:
 390                                 s[++sp] = (val1 != val2);
 391                                 break;
 392                         default:
 393                                 BUG();
 394                                 return 0;
 395                         }
 396                         break;
 397                 case CEXPR_NAMES:
 398                         if (sp == (CEXPR_MAXDEPTH-1))
 399                                 return 0;
 400                         c = scontext;
 401                         if (e->attr & CEXPR_TARGET)
 402                                 c = tcontext;
 403                         else if (e->attr & CEXPR_XTARGET) {
 404                                 c = xcontext;
 405                                 if (!c) {
 406                                         BUG();
 407                                         return 0;
 408                                 }
 409                         }
 410                         if (e->attr & CEXPR_USER)
 411                                 val1 = c->user;
 412                         else if (e->attr & CEXPR_ROLE)
 413                                 val1 = c->role;
 414                         else if (e->attr & CEXPR_TYPE)
 415                                 val1 = c->type;
 416                         else {
 417                                 BUG();
 418                                 return 0;
 419                         }
 420
 421                         switch (e->op) {
 422                         case CEXPR_EQ:
 423                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 424                                 break;
 425                         case CEXPR_NEQ:
 426                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 427                                 break;
 428                         default:
 429                                 BUG();
 430                                 return 0;
 431                         }
 432                         break;
 433                 default:
 434                         BUG();
 435                         return 0;
 436                 }
 437         }
 438
 439         BUG_ON(sp != 0);
 440         return s[0];
 441 }
 442
 443 /*
 444  * security_dump_masked_av - dumps masked permissions during
 445  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 446  */
 447 static int dump_masked_av_helper(void *k, void *d, void *args)
 448 {
 449         struct perm_datum *pdatum = d;
 450         char **permission_names = args;
 451
 452         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 453
 454         permission_names[pdatum->value - 1] = (char *)k;
 455
 456         return 0;
 457 }
 458
 459 static void security_dump_masked_av(struct policydb *policydb,
 460                                     struct context *scontext,
 461                                     struct context *tcontext,
 462                                     u16 tclass,
 463                                     u32 permissions,
 464                                     const char *reason)
 465 {
 466         struct common_datum *common_dat;
 467         struct class_datum *tclass_dat;
 468         struct audit_buffer *ab;
 469         char *tclass_name;
 470         char *scontext_name = NULL;
 471         char *tcontext_name = NULL;
 472         char *permission_names[32];
 473         int index;
 474         u32 length;
 475         bool need_comma = false;
 476
 477         if (!permissions)
 478                 return;
 479
 480         tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
 481         tclass_dat = policydb->class_val_to_struct[tclass - 1];
 482         common_dat = tclass_dat->comdatum;
 483
 484         /* init permission_names */
 485         if (common_dat &&
 486             hashtab_map(&common_dat->permissions.table,
 487                         dump_masked_av_helper, permission_names) < 0)
 488                 goto out;
 489
 490         if (hashtab_map(&tclass_dat->permissions.table,
 491                         dump_masked_av_helper, permission_names) < 0)
 492                 goto out;
 493
 494         /* get scontext/tcontext in text form */
 495         if (context_struct_to_string(policydb, scontext,
 496                                      &scontext_name, &length) < 0)
 497                 goto out;
 498
 499         if (context_struct_to_string(policydb, tcontext,
 500                                      &tcontext_name, &length) < 0)
 501                 goto out;
 502
 503         /* audit a message */
 504         ab = audit_log_start(audit_context(),
 505                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 506         if (!ab)
 507                 goto out;
 508
 509         audit_log_format(ab, "op=security_compute_av reason=%s "
 510                          "scontext=%s tcontext=%s tclass=%s perms=",
 511                          reason, scontext_name, tcontext_name, tclass_name);
 512
 513         for (index = 0; index < 32; index++) {
 514                 u32 mask = (1 << index);
 515
 516                 if ((mask & permissions) == 0)
 517                         continue;
 518
 519                 audit_log_format(ab, "%s%s",
 520                                  need_comma ? "," : "",
 521                                  permission_names[index]
 522                                  ? permission_names[index] : "????");
 523                 need_comma = true;
 524         }
 525         audit_log_end(ab);
 526 out:
 527         /* release scontext/tcontext */
 528         kfree(tcontext_name);
 529         kfree(scontext_name);
 530
 531         return;
 532 }
 533
 534 /*
 535  * security_boundary_permission - drops violated permissions
 536  * on boundary constraint.
 537  */
 538 static void type_attribute_bounds_av(struct policydb *policydb,
 539                                      struct context *scontext,
 540                                      struct context *tcontext,
 541                                      u16 tclass,
 542                                      struct av_decision *avd)
 543 {
 544         struct context lo_scontext;
 545         struct context lo_tcontext, *tcontextp = tcontext;
 546         struct av_decision lo_avd;
 547         struct type_datum *source;
 548         struct type_datum *target;
 549         u32 masked = 0;
 550
 551         source = policydb->type_val_to_struct[scontext->type - 1];
 552         BUG_ON(!source);
 553
 554         if (!source->bounds)
 555                 return;
 556
 557         target = policydb->type_val_to_struct[tcontext->type - 1];
 558         BUG_ON(!target);
 559
 560         memset(&lo_avd, 0, sizeof(lo_avd));
 561
 562         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 563         lo_scontext.type = source->bounds;
 564
 565         if (target->bounds) {
 566                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 567                 lo_tcontext.type = target->bounds;
 568                 tcontextp = &lo_tcontext;
 569         }
 570
 571         context_struct_compute_av(policydb, &lo_scontext,
 572                                   tcontextp,
 573                                   tclass,
 574                                   &lo_avd,
 575                                   NULL);
 576
 577         masked = ~lo_avd.allowed & avd->allowed;
 578
 579         if (likely(!masked))
 580                 return;         /* no masked permission */
 581
 582         /* mask violated permissions */
 583         avd->allowed &= ~masked;
 584
 585         /* audit masked permissions */
 586         security_dump_masked_av(policydb, scontext, tcontext,
 587                                 tclass, masked, "bounds");
 588 }
 589
 590 /*
 591  * flag which drivers have permissions
 592  * only looking for ioctl based extended permssions
 593  */
 594 void services_compute_xperms_drivers(
 595                 struct extended_perms *xperms,
 596                 struct avtab_node *node)
 597 {
 598         unsigned int i;
 599
 600         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 601                 /* if one or more driver has all permissions allowed */
 602                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 603                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 604         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 605                 /* if allowing permissions within a driver */
 606                 security_xperm_set(xperms->drivers.p,
 607                                         node->datum.u.xperms->driver);
 608         }
 609
 610         /* If no ioctl commands are allowed, ignore auditallow and auditdeny */
 611         if (node->key.specified & AVTAB_XPERMS_ALLOWED)
 612                 xperms->len = 1;
 613 }
 614
 615 /*
 616  * Compute access vectors and extended permissions based on a context
 617  * structure pair for the permissions in a particular class.
 618  */
 619 static void context_struct_compute_av(struct policydb *policydb,
 620                                       struct context *scontext,
 621                                       struct context *tcontext,
 622                                       u16 tclass,
 623                                       struct av_decision *avd,
 624                                       struct extended_perms *xperms)
 625 {
 626         struct constraint_node *constraint;
 627         struct role_allow *ra;
 628         struct avtab_key avkey;
 629         struct avtab_node *node;
 630         struct class_datum *tclass_datum;
 631         struct ebitmap *sattr, *tattr;
 632         struct ebitmap_node *snode, *tnode;
 633         unsigned int i, j;
 634
 635         avd->allowed = 0;
 636         avd->auditallow = 0;
 637         avd->auditdeny = 0xffffffff;
 638         if (xperms) {
 639                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
 640                 xperms->len = 0;
 641         }
 642
 643         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
 644                 if (printk_ratelimit())
 645                         pr_warn("SELinux:  Invalid class %hu\n", tclass);
 646                 return;
 647         }
 648
 649         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 650
 651         /*
 652          * If a specific type enforcement rule was defined for
 653          * this permission check, then use it.
 654          */
 655         avkey.target_class = tclass;
 656         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
 657         sattr = &policydb->type_attr_map_array[scontext->type - 1];
 658         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
 659         ebitmap_for_each_positive_bit(sattr, snode, i) {
 660                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 661                         avkey.source_type = i + 1;
 662                         avkey.target_type = j + 1;
 663                         for (node = avtab_search_node(&policydb->te_avtab,
 664                                                       &avkey);
 665                              node;
 666                              node = avtab_search_node_next(node, avkey.specified)) {
 667                                 if (node->key.specified == AVTAB_ALLOWED)
 668                                         avd->allowed |= node->datum.u.data;
 669                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 670                                         avd->auditallow |= node->datum.u.data;
 671                                 else if (node->key.specified == AVTAB_AUDITDENY)
 672                                         avd->auditdeny &= node->datum.u.data;
 673                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
 674                                         services_compute_xperms_drivers(xperms, node);
 675                         }
 676
 677                         /* Check conditional av table for additional permissions */
 678                         cond_compute_av(&policydb->te_cond_avtab, &avkey,
 679                                         avd, xperms);
 680
 681                 }
 682         }
 683
 684         /*
 685          * Remove any permissions prohibited by a constraint (this includes
 686          * the MLS policy).
 687          */
 688         constraint = tclass_datum->constraints;
 689         while (constraint) {
 690                 if ((constraint->permissions & (avd->allowed)) &&
 691                     !constraint_expr_eval(policydb, scontext, tcontext, NULL,
 692                                           constraint->expr)) {
 693                         avd->allowed &= ~(constraint->permissions);
 694                 }
 695                 constraint = constraint->next;
 696         }
 697
 698         /*
 699          * If checking process transition permission and the
 700          * role is changing, then check the (current_role, new_role)
 701          * pair.
 702          */
 703         if (tclass == policydb->process_class &&
 704             (avd->allowed & policydb->process_trans_perms) &&
 705             scontext->role != tcontext->role) {
 706                 for (ra = policydb->role_allow; ra; ra = ra->next) {
 707                         if (scontext->role == ra->role &&
 708                             tcontext->role == ra->new_role)
 709                                 break;
 710                 }
 711                 if (!ra)
 712                         avd->allowed &= ~policydb->process_trans_perms;
 713         }
 714
 715         /*
 716          * If the given source and target types have boundary
 717          * constraint, lazy checks have to mask any violated
 718          * permission and notice it to userspace via audit.
 719          */
 720         type_attribute_bounds_av(policydb, scontext, tcontext,
 721                                  tclass, avd);
 722 }
 723
 724 static int security_validtrans_handle_fail(struct selinux_state *state,
 725                                         struct selinux_policy *policy,
 726                                         struct sidtab_entry *oentry,
 727                                         struct sidtab_entry *nentry,
 728                                         struct sidtab_entry *tentry,
 729                                         u16 tclass)
 730 {
 731         struct policydb *p = &policy->policydb;
 732         struct sidtab *sidtab = policy->sidtab;
 733         char *o = NULL, *n = NULL, *t = NULL;
 734         u32 olen, nlen, tlen;
 735
 736         if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
 737                 goto out;
 738         if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
 739                 goto out;
 740         if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
 741                 goto out;
 742         audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
 743                   "op=security_validate_transition seresult=denied"
 744                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 745                   o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
 746 out:
 747         kfree(o);
 748         kfree(n);
 749         kfree(t);
 750
 751         if (!enforcing_enabled(state))
 752                 return 0;
 753         return -EPERM;
 754 }
 755
 756 static int security_compute_validatetrans(struct selinux_state *state,
 757                                           u32 oldsid, u32 newsid, u32 tasksid,
 758                                           u16 orig_tclass, bool user)
 759 {
 760         struct selinux_policy *policy;
 761         struct policydb *policydb;
 762         struct sidtab *sidtab;
 763         struct sidtab_entry *oentry;
 764         struct sidtab_entry *nentry;
 765         struct sidtab_entry *tentry;
 766         struct class_datum *tclass_datum;
 767         struct constraint_node *constraint;
 768         u16 tclass;
 769         int rc = 0;
 770
 771
 772         if (!selinux_initialized(state))
 773                 return 0;
 774
 775         rcu_read_lock();
 776
 777         policy = rcu_dereference(state->policy);
 778         policydb = &policy->policydb;
 779         sidtab = policy->sidtab;
 780
 781         if (!user)
 782                 tclass = unmap_class(&policy->map, orig_tclass);
 783         else
 784                 tclass = orig_tclass;
 785
 786         if (!tclass || tclass > policydb->p_classes.nprim) {
 787                 rc = -EINVAL;
 788                 goto out;
 789         }
 790         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 791
 792         oentry = sidtab_search_entry(sidtab, oldsid);
 793         if (!oentry) {
 794                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 795                         __func__, oldsid);
 796                 rc = -EINVAL;
 797                 goto out;
 798         }
 799
 800         nentry = sidtab_search_entry(sidtab, newsid);
 801         if (!nentry) {
 802                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 803                         __func__, newsid);
 804                 rc = -EINVAL;
 805                 goto out;
 806         }
 807
 808         tentry = sidtab_search_entry(sidtab, tasksid);
 809         if (!tentry) {
 810                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 811                         __func__, tasksid);
 812                 rc = -EINVAL;
 813                 goto out;
 814         }
 815
 816         constraint = tclass_datum->validatetrans;
 817         while (constraint) {
 818                 if (!constraint_expr_eval(policydb, &oentry->context,
 819                                           &nentry->context, &tentry->context,
 820                                           constraint->expr)) {
 821                         if (user)
 822                                 rc = -EPERM;
 823                         else
 824                                 rc = security_validtrans_handle_fail(state,
 825                                                                 policy,
 826                                                                 oentry,
 827                                                                 nentry,
 828                                                                 tentry,
 829                                                                 tclass);
 830                         goto out;
 831                 }
 832                 constraint = constraint->next;
 833         }
 834
 835 out:
 836         rcu_read_unlock();
 837         return rc;
 838 }
 839
 840 int security_validate_transition_user(struct selinux_state *state,
 841                                       u32 oldsid, u32 newsid, u32 tasksid,
 842                                       u16 tclass)
 843 {
 844         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 845                                               tclass, true);
 846 }
 847
 848 int security_validate_transition(struct selinux_state *state,
 849                                  u32 oldsid, u32 newsid, u32 tasksid,
 850                                  u16 orig_tclass)
 851 {
 852         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 853                                               orig_tclass, false);
 854 }
 855
 856 /*
 857  * security_bounded_transition - check whether the given
 858  * transition is directed to bounded, or not.
 859  * It returns 0, if @newsid is bounded by @oldsid.
 860  * Otherwise, it returns error code.
 861  *
 862  * @oldsid : current security identifier
 863  * @newsid : destinated security identifier
 864  */
 865 int security_bounded_transition(struct selinux_state *state,
 866                                 u32 old_sid, u32 new_sid)
 867 {
 868         struct selinux_policy *policy;
 869         struct policydb *policydb;
 870         struct sidtab *sidtab;
 871         struct sidtab_entry *old_entry, *new_entry;
 872         struct type_datum *type;
 873         int index;
 874         int rc;
 875
 876         if (!selinux_initialized(state))
 877                 return 0;
 878
 879         rcu_read_lock();
 880         policy = rcu_dereference(state->policy);
 881         policydb = &policy->policydb;
 882         sidtab = policy->sidtab;
 883
 884         rc = -EINVAL;
 885         old_entry = sidtab_search_entry(sidtab, old_sid);
 886         if (!old_entry) {
 887                 pr_err("SELinux: %s: unrecognized SID %u\n",
 888                        __func__, old_sid);
 889                 goto out;
 890         }
 891
 892         rc = -EINVAL;
 893         new_entry = sidtab_search_entry(sidtab, new_sid);
 894         if (!new_entry) {
 895                 pr_err("SELinux: %s: unrecognized SID %u\n",
 896                        __func__, new_sid);
 897                 goto out;
 898         }
 899
 900         rc = 0;
 901         /* type/domain unchanged */
 902         if (old_entry->context.type == new_entry->context.type)
 903                 goto out;
 904
 905         index = new_entry->context.type;
 906         while (true) {
 907                 type = policydb->type_val_to_struct[index - 1];
 908                 BUG_ON(!type);
 909
 910                 /* not bounded anymore */
 911                 rc = -EPERM;
 912                 if (!type->bounds)
 913                         break;
 914
 915                 /* @newsid is bounded by @oldsid */
 916                 rc = 0;
 917                 if (type->bounds == old_entry->context.type)
 918                         break;
 919
 920                 index = type->bounds;
 921         }
 922
 923         if (rc) {
 924                 char *old_name = NULL;
 925                 char *new_name = NULL;
 926                 u32 length;
 927
 928                 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
 929                                             &old_name, &length) &&
 930                     !sidtab_entry_to_string(policydb, sidtab, new_entry,
 931                                             &new_name, &length)) {
 932                         audit_log(audit_context(),
 933                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 934                                   "op=security_bounded_transition "
 935                                   "seresult=denied "
 936                                   "oldcontext=%s newcontext=%s",
 937                                   old_name, new_name);
 938                 }
 939                 kfree(new_name);
 940                 kfree(old_name);
 941         }
 942 out:
 943         rcu_read_unlock();
 944
 945         return rc;
 946 }
 947
 948 static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
 949 {
 950         avd->allowed = 0;
 951         avd->auditallow = 0;
 952         avd->auditdeny = 0xffffffff;
 953         if (policy)
 954                 avd->seqno = policy->latest_granting;
 955         else
 956                 avd->seqno = 0;
 957         avd->flags = 0;
 958 }
 959
 960 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 961                                         struct avtab_node *node)
 962 {
 963         unsigned int i;
 964
 965         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 966                 if (xpermd->driver != node->datum.u.xperms->driver)
 967                         return;
 968         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 969                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 970                                         xpermd->driver))
 971                         return;
 972         } else {
 973                 BUG();
 974         }
 975
 976         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 977                 xpermd->used |= XPERMS_ALLOWED;
 978                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 979                         memset(xpermd->allowed->p, 0xff,
 980                                         sizeof(xpermd->allowed->p));
 981                 }
 982                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 983                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 984                                 xpermd->allowed->p[i] |=
 985                                         node->datum.u.xperms->perms.p[i];
 986                 }
 987         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 988                 xpermd->used |= XPERMS_AUDITALLOW;
 989                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 990                         memset(xpermd->auditallow->p, 0xff,
 991                                         sizeof(xpermd->auditallow->p));
 992                 }
 993                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 994                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 995                                 xpermd->auditallow->p[i] |=
 996                                         node->datum.u.xperms->perms.p[i];
 997                 }
 998         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 999                 xpermd->used |= XPERMS_DONTAUDIT;
1000                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
1001                         memset(xpermd->dontaudit->p, 0xff,
1002                                         sizeof(xpermd->dontaudit->p));
1003                 }
1004                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1005                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1006                                 xpermd->dontaudit->p[i] |=
1007                                         node->datum.u.xperms->perms.p[i];
1008                 }
1009         } else {
1010                 BUG();
1011         }
1012 }
1013
1014 void security_compute_xperms_decision(struct selinux_state *state,
1015                                       u32 ssid,
1016                                       u32 tsid,
1017                                       u16 orig_tclass,
1018                                       u8 driver,
1019                                       struct extended_perms_decision *xpermd)
1020 {
1021         struct selinux_policy *policy;
1022         struct policydb *policydb;
1023         struct sidtab *sidtab;
1024         u16 tclass;
1025         struct context *scontext, *tcontext;
1026         struct avtab_key avkey;
1027         struct avtab_node *node;
1028         struct ebitmap *sattr, *tattr;
1029         struct ebitmap_node *snode, *tnode;
1030         unsigned int i, j;
1031
1032         xpermd->driver = driver;
1033         xpermd->used = 0;
1034         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1035         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1036         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1037
1038         rcu_read_lock();
1039         if (!selinux_initialized(state))
1040                 goto allow;
1041
1042         policy = rcu_dereference(state->policy);
1043         policydb = &policy->policydb;
1044         sidtab = policy->sidtab;
1045
1046         scontext = sidtab_search(sidtab, ssid);
1047         if (!scontext) {
1048                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1049                        __func__, ssid);
1050                 goto out;
1051         }
1052
1053         tcontext = sidtab_search(sidtab, tsid);
1054         if (!tcontext) {
1055                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1056                        __func__, tsid);
1057                 goto out;
1058         }
1059
1060         tclass = unmap_class(&policy->map, orig_tclass);
1061         if (unlikely(orig_tclass && !tclass)) {
1062                 if (policydb->allow_unknown)
1063                         goto allow;
1064                 goto out;
1065         }
1066
1067
1068         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1069                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1070                 goto out;
1071         }
1072
1073         avkey.target_class = tclass;
1074         avkey.specified = AVTAB_XPERMS;
1075         sattr = &policydb->type_attr_map_array[scontext->type - 1];
1076         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1077         ebitmap_for_each_positive_bit(sattr, snode, i) {
1078                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1079                         avkey.source_type = i + 1;
1080                         avkey.target_type = j + 1;
1081                         for (node = avtab_search_node(&policydb->te_avtab,
1082                                                       &avkey);
1083                              node;
1084                              node = avtab_search_node_next(node, avkey.specified))
1085                                 services_compute_xperms_decision(xpermd, node);
1086
1087                         cond_compute_xperms(&policydb->te_cond_avtab,
1088                                                 &avkey, xpermd);
1089                 }
1090         }
1091 out:
1092         rcu_read_unlock();
1093         return;
1094 allow:
1095         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1096         goto out;
1097 }
1098
1099 /**
1100  * security_compute_av - Compute access vector decisions.
1101  * @ssid: source security identifier
1102  * @tsid: target security identifier
1103  * @tclass: target security class
1104  * @avd: access vector decisions
1105  * @xperms: extended permissions
1106  *
1107  * Compute a set of access vector decisions based on the
1108  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1109  */
1110 void security_compute_av(struct selinux_state *state,
1111                          u32 ssid,
1112                          u32 tsid,
1113                          u16 orig_tclass,
1114                          struct av_decision *avd,
1115                          struct extended_perms *xperms)
1116 {
1117         struct selinux_policy *policy;
1118         struct policydb *policydb;
1119         struct sidtab *sidtab;
1120         u16 tclass;
1121         struct context *scontext = NULL, *tcontext = NULL;
1122
1123         rcu_read_lock();
1124         policy = rcu_dereference(state->policy);
1125         avd_init(policy, avd);
1126         xperms->len = 0;
1127         if (!selinux_initialized(state))
1128                 goto allow;
1129
1130         policydb = &policy->policydb;
1131         sidtab = policy->sidtab;
1132
1133         scontext = sidtab_search(sidtab, ssid);
1134         if (!scontext) {
1135                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1136                        __func__, ssid);
1137                 goto out;
1138         }
1139
1140         /* permissive domain? */
1141         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1142                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1143
1144         tcontext = sidtab_search(sidtab, tsid);
1145         if (!tcontext) {
1146                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1147                        __func__, tsid);
1148                 goto out;
1149         }
1150
1151         tclass = unmap_class(&policy->map, orig_tclass);
1152         if (unlikely(orig_tclass && !tclass)) {
1153                 if (policydb->allow_unknown)
1154                         goto allow;
1155                 goto out;
1156         }
1157         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1158                                   xperms);
1159         map_decision(&policy->map, orig_tclass, avd,
1160                      policydb->allow_unknown);
1161 out:
1162         rcu_read_unlock();
1163         return;
1164 allow:
1165         avd->allowed = 0xffffffff;
1166         goto out;
1167 }
1168
1169 void security_compute_av_user(struct selinux_state *state,
1170                               u32 ssid,
1171                               u32 tsid,
1172                               u16 tclass,
1173                               struct av_decision *avd)
1174 {
1175         struct selinux_policy *policy;
1176         struct policydb *policydb;
1177         struct sidtab *sidtab;
1178         struct context *scontext = NULL, *tcontext = NULL;
1179
1180         rcu_read_lock();
1181         policy = rcu_dereference(state->policy);
1182         avd_init(policy, avd);
1183         if (!selinux_initialized(state))
1184                 goto allow;
1185
1186         policydb = &policy->policydb;
1187         sidtab = policy->sidtab;
1188
1189         scontext = sidtab_search(sidtab, ssid);
1190         if (!scontext) {
1191                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1192                        __func__, ssid);
1193                 goto out;
1194         }
1195
1196         /* permissive domain? */
1197         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1198                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1199
1200         tcontext = sidtab_search(sidtab, tsid);
1201         if (!tcontext) {
1202                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1203                        __func__, tsid);
1204                 goto out;
1205         }
1206
1207         if (unlikely(!tclass)) {
1208                 if (policydb->allow_unknown)
1209                         goto allow;
1210                 goto out;
1211         }
1212
1213         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1214                                   NULL);
1215  out:
1216         rcu_read_unlock();
1217         return;
1218 allow:
1219         avd->allowed = 0xffffffff;
1220         goto out;
1221 }
1222
1223 /*
1224  * Write the security context string representation of
1225  * the context structure `context' into a dynamically
1226  * allocated string of the correct size.  Set `*scontext'
1227  * to point to this string and set `*scontext_len' to
1228  * the length of the string.
1229  */
1230 static int context_struct_to_string(struct policydb *p,
1231                                     struct context *context,
1232                                     char **scontext, u32 *scontext_len)
1233 {
1234         char *scontextp;
1235
1236         if (scontext)
1237                 *scontext = NULL;
1238         *scontext_len = 0;
1239
1240         if (context->len) {
1241                 *scontext_len = context->len;
1242                 if (scontext) {
1243                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1244                         if (!(*scontext))
1245                                 return -ENOMEM;
1246                 }
1247                 return 0;
1248         }
1249
1250         /* Compute the size of the context. */
1251         *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1252         *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1253         *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1254         *scontext_len += mls_compute_context_len(p, context);
1255
1256         if (!scontext)
1257                 return 0;
1258
1259         /* Allocate space for the context; caller must free this space. */
1260         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1261         if (!scontextp)
1262                 return -ENOMEM;
1263         *scontext = scontextp;
1264
1265         /*
1266          * Copy the user name, role name and type name into the context.
1267          */
1268         scontextp += sprintf(scontextp, "%s:%s:%s",
1269                 sym_name(p, SYM_USERS, context->user - 1),
1270                 sym_name(p, SYM_ROLES, context->role - 1),
1271                 sym_name(p, SYM_TYPES, context->type - 1));
1272
1273         mls_sid_to_context(p, context, &scontextp);
1274
1275         *scontextp = 0;
1276
1277         return 0;
1278 }
1279
1280 static int sidtab_entry_to_string(struct policydb *p,
1281                                   struct sidtab *sidtab,
1282                                   struct sidtab_entry *entry,
1283                                   char **scontext, u32 *scontext_len)
1284 {
1285         int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1286
1287         if (rc != -ENOENT)
1288                 return rc;
1289
1290         rc = context_struct_to_string(p, &entry->context, scontext,
1291                                       scontext_len);
1292         if (!rc && scontext)
1293                 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1294         return rc;
1295 }
1296
1297 #include "initial_sid_to_string.h"
1298
1299 int security_sidtab_hash_stats(struct selinux_state *state, char *page)
1300 {
1301         struct selinux_policy *policy;
1302         int rc;
1303
1304         if (!selinux_initialized(state)) {
1305                 pr_err("SELinux: %s:  called before initial load_policy\n",
1306                        __func__);
1307                 return -EINVAL;
1308         }
1309
1310         rcu_read_lock();
1311         policy = rcu_dereference(state->policy);
1312         rc = sidtab_hash_stats(policy->sidtab, page);
1313         rcu_read_unlock();
1314
1315         return rc;
1316 }
1317
1318 const char *security_get_initial_sid_context(u32 sid)
1319 {
1320         if (unlikely(sid > SECINITSID_NUM))
1321                 return NULL;
1322         return initial_sid_to_string[sid];
1323 }
1324
1325 static int security_sid_to_context_core(struct selinux_state *state,
1326                                         u32 sid, char **scontext,
1327                                         u32 *scontext_len, int force,
1328                                         int only_invalid)
1329 {
1330         struct selinux_policy *policy;
1331         struct policydb *policydb;
1332         struct sidtab *sidtab;
1333         struct sidtab_entry *entry;
1334         int rc = 0;
1335
1336         if (scontext)
1337                 *scontext = NULL;
1338         *scontext_len  = 0;
1339
1340         if (!selinux_initialized(state)) {
1341                 if (sid <= SECINITSID_NUM) {
1342                         char *scontextp;
1343                         const char *s = initial_sid_to_string[sid];
1344
1345                         if (!s)
1346                                 return -EINVAL;
1347                         *scontext_len = strlen(s) + 1;
1348                         if (!scontext)
1349                                 return 0;
1350                         scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1351                         if (!scontextp)
1352                                 return -ENOMEM;
1353                         *scontext = scontextp;
1354                         return 0;
1355                 }
1356                 pr_err("SELinux: %s:  called before initial "
1357                        "load_policy on unknown SID %d\n", __func__, sid);
1358                 return -EINVAL;
1359         }
1360         rcu_read_lock();
1361         policy = rcu_dereference(state->policy);
1362         policydb = &policy->policydb;
1363         sidtab = policy->sidtab;
1364
1365         if (force)
1366                 entry = sidtab_search_entry_force(sidtab, sid);
1367         else
1368                 entry = sidtab_search_entry(sidtab, sid);
1369         if (!entry) {
1370                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1371                         __func__, sid);
1372                 rc = -EINVAL;
1373                 goto out_unlock;
1374         }
1375         if (only_invalid && !entry->context.len)
1376                 goto out_unlock;
1377
1378         rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1379                                     scontext_len);
1380
1381 out_unlock:
1382         rcu_read_unlock();
1383         return rc;
1384
1385 }
1386
1387 /**
1388  * security_sid_to_context - Obtain a context for a given SID.
1389  * @sid: security identifier, SID
1390  * @scontext: security context
1391  * @scontext_len: length in bytes
1392  *
1393  * Write the string representation of the context associated with @sid
1394  * into a dynamically allocated string of the correct size.  Set @scontext
1395  * to point to this string and set @scontext_len to the length of the string.
1396  */
1397 int security_sid_to_context(struct selinux_state *state,
1398                             u32 sid, char **scontext, u32 *scontext_len)
1399 {
1400         return security_sid_to_context_core(state, sid, scontext,
1401                                             scontext_len, 0, 0);
1402 }
1403
1404 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1405                                   char **scontext, u32 *scontext_len)
1406 {
1407         return security_sid_to_context_core(state, sid, scontext,
1408                                             scontext_len, 1, 0);
1409 }
1410
1411 /**
1412  * security_sid_to_context_inval - Obtain a context for a given SID if it
1413  *                                 is invalid.
1414  * @sid: security identifier, SID
1415  * @scontext: security context
1416  * @scontext_len: length in bytes
1417  *
1418  * Write the string representation of the context associated with @sid
1419  * into a dynamically allocated string of the correct size, but only if the
1420  * context is invalid in the current policy.  Set @scontext to point to
1421  * this string (or NULL if the context is valid) and set @scontext_len to
1422  * the length of the string (or 0 if the context is valid).
1423  */
1424 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1425                                   char **scontext, u32 *scontext_len)
1426 {
1427         return security_sid_to_context_core(state, sid, scontext,
1428                                             scontext_len, 1, 1);
1429 }
1430
1431 /*
1432  * Caveat:  Mutates scontext.
1433  */
1434 static int string_to_context_struct(struct policydb *pol,
1435                                     struct sidtab *sidtabp,
1436                                     char *scontext,
1437                                     struct context *ctx,
1438                                     u32 def_sid)
1439 {
1440         struct role_datum *role;
1441         struct type_datum *typdatum;
1442         struct user_datum *usrdatum;
1443         char *scontextp, *p, oldc;
1444         int rc = 0;
1445
1446         context_init(ctx);
1447
1448         /* Parse the security context. */
1449
1450         rc = -EINVAL;
1451         scontextp = (char *) scontext;
1452
1453         /* Extract the user. */
1454         p = scontextp;
1455         while (*p && *p != ':')
1456                 p++;
1457
1458         if (*p == 0)
1459                 goto out;
1460
1461         *p++ = 0;
1462
1463         usrdatum = symtab_search(&pol->p_users, scontextp);
1464         if (!usrdatum)
1465                 goto out;
1466
1467         ctx->user = usrdatum->value;
1468
1469         /* Extract role. */
1470         scontextp = p;
1471         while (*p && *p != ':')
1472                 p++;
1473
1474         if (*p == 0)
1475                 goto out;
1476
1477         *p++ = 0;
1478
1479         role = symtab_search(&pol->p_roles, scontextp);
1480         if (!role)
1481                 goto out;
1482         ctx->role = role->value;
1483
1484         /* Extract type. */
1485         scontextp = p;
1486         while (*p && *p != ':')
1487                 p++;
1488         oldc = *p;
1489         *p++ = 0;
1490
1491         typdatum = symtab_search(&pol->p_types, scontextp);
1492         if (!typdatum || typdatum->attribute)
1493                 goto out;
1494
1495         ctx->type = typdatum->value;
1496
1497         rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1498         if (rc)
1499                 goto out;
1500
1501         /* Check the validity of the new context. */
1502         rc = -EINVAL;
1503         if (!policydb_context_isvalid(pol, ctx))
1504                 goto out;
1505         rc = 0;
1506 out:
1507         if (rc)
1508                 context_destroy(ctx);
1509         return rc;
1510 }
1511
1512 static int security_context_to_sid_core(struct selinux_state *state,
1513                                         const char *scontext, u32 scontext_len,
1514                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1515                                         int force)
1516 {
1517         struct selinux_policy *policy;
1518         struct policydb *policydb;
1519         struct sidtab *sidtab;
1520         char *scontext2, *str = NULL;
1521         struct context context;
1522         int rc = 0;
1523
1524         /* An empty security context is never valid. */
1525         if (!scontext_len)
1526                 return -EINVAL;
1527
1528         /* Copy the string to allow changes and ensure a NUL terminator */
1529         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1530         if (!scontext2)
1531                 return -ENOMEM;
1532
1533         if (!selinux_initialized(state)) {
1534                 int i;
1535
1536                 for (i = 1; i < SECINITSID_NUM; i++) {
1537                         const char *s = initial_sid_to_string[i];
1538
1539                         if (s && !strcmp(s, scontext2)) {
1540                                 *sid = i;
1541                                 goto out;
1542                         }
1543                 }
1544                 *sid = SECINITSID_KERNEL;
1545                 goto out;
1546         }
1547         *sid = SECSID_NULL;
1548
1549         if (force) {
1550                 /* Save another copy for storing in uninterpreted form */
1551                 rc = -ENOMEM;
1552                 str = kstrdup(scontext2, gfp_flags);
1553                 if (!str)
1554                         goto out;
1555         }
1556 retry:
1557         rcu_read_lock();
1558         policy = rcu_dereference(state->policy);
1559         policydb = &policy->policydb;
1560         sidtab = policy->sidtab;
1561         rc = string_to_context_struct(policydb, sidtab, scontext2,
1562                                       &context, def_sid);
1563         if (rc == -EINVAL && force) {
1564                 context.str = str;
1565                 context.len = strlen(str) + 1;
1566                 str = NULL;
1567         } else if (rc)
1568                 goto out_unlock;
1569         rc = sidtab_context_to_sid(sidtab, &context, sid);
1570         if (rc == -ESTALE) {
1571                 rcu_read_unlock();
1572                 if (context.str) {
1573                         str = context.str;
1574                         context.str = NULL;
1575                 }
1576                 context_destroy(&context);
1577                 goto retry;
1578         }
1579         context_destroy(&context);
1580 out_unlock:
1581         rcu_read_unlock();
1582 out:
1583         kfree(scontext2);
1584         kfree(str);
1585         return rc;
1586 }
1587
1588 /**
1589  * security_context_to_sid - Obtain a SID for a given security context.
1590  * @scontext: security context
1591  * @scontext_len: length in bytes
1592  * @sid: security identifier, SID
1593  * @gfp: context for the allocation
1594  *
1595  * Obtains a SID associated with the security context that
1596  * has the string representation specified by @scontext.
1597  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1598  * memory is available, or 0 on success.
1599  */
1600 int security_context_to_sid(struct selinux_state *state,
1601                             const char *scontext, u32 scontext_len, u32 *sid,
1602                             gfp_t gfp)
1603 {
1604         return security_context_to_sid_core(state, scontext, scontext_len,
1605                                             sid, SECSID_NULL, gfp, 0);
1606 }
1607
1608 int security_context_str_to_sid(struct selinux_state *state,
1609                                 const char *scontext, u32 *sid, gfp_t gfp)
1610 {
1611         return security_context_to_sid(state, scontext, strlen(scontext),
1612                                        sid, gfp);
1613 }
1614
1615 /**
1616  * security_context_to_sid_default - Obtain a SID for a given security context,
1617  * falling back to specified default if needed.
1618  *
1619  * @scontext: security context
1620  * @scontext_len: length in bytes
1621  * @sid: security identifier, SID
1622  * @def_sid: default SID to assign on error
1623  *
1624  * Obtains a SID associated with the security context that
1625  * has the string representation specified by @scontext.
1626  * The default SID is passed to the MLS layer to be used to allow
1627  * kernel labeling of the MLS field if the MLS field is not present
1628  * (for upgrading to MLS without full relabel).
1629  * Implicitly forces adding of the context even if it cannot be mapped yet.
1630  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1631  * memory is available, or 0 on success.
1632  */
1633 int security_context_to_sid_default(struct selinux_state *state,
1634                                     const char *scontext, u32 scontext_len,
1635                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1636 {
1637         return security_context_to_sid_core(state, scontext, scontext_len,
1638                                             sid, def_sid, gfp_flags, 1);
1639 }
1640
1641 int security_context_to_sid_force(struct selinux_state *state,
1642                                   const char *scontext, u32 scontext_len,
1643                                   u32 *sid)
1644 {
1645         return security_context_to_sid_core(state, scontext, scontext_len,
1646                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1647 }
1648
1649 static int compute_sid_handle_invalid_context(
1650         struct selinux_state *state,
1651         struct selinux_policy *policy,
1652         struct sidtab_entry *sentry,
1653         struct sidtab_entry *tentry,
1654         u16 tclass,
1655         struct context *newcontext)
1656 {
1657         struct policydb *policydb = &policy->policydb;
1658         struct sidtab *sidtab = policy->sidtab;
1659         char *s = NULL, *t = NULL, *n = NULL;
1660         u32 slen, tlen, nlen;
1661         struct audit_buffer *ab;
1662
1663         if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1664                 goto out;
1665         if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1666                 goto out;
1667         if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1668                 goto out;
1669         ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1670         audit_log_format(ab,
1671                          "op=security_compute_sid invalid_context=");
1672         /* no need to record the NUL with untrusted strings */
1673         audit_log_n_untrustedstring(ab, n, nlen - 1);
1674         audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1675                          s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1676         audit_log_end(ab);
1677 out:
1678         kfree(s);
1679         kfree(t);
1680         kfree(n);
1681         if (!enforcing_enabled(state))
1682                 return 0;
1683         return -EACCES;
1684 }
1685
1686 static void filename_compute_type(struct policydb *policydb,
1687                                   struct context *newcontext,
1688                                   u32 stype, u32 ttype, u16 tclass,
1689                                   const char *objname)
1690 {
1691         struct filename_trans_key ft;
1692         struct filename_trans_datum *datum;
1693
1694         /*
1695          * Most filename trans rules are going to live in specific directories
1696          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1697          * if the ttype does not contain any rules.
1698          */
1699         if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1700                 return;
1701
1702         ft.ttype = ttype;
1703         ft.tclass = tclass;
1704         ft.name = objname;
1705
1706         datum = policydb_filenametr_search(policydb, &ft);
1707         while (datum) {
1708                 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1709                         newcontext->type = datum->otype;
1710                         return;
1711                 }
1712                 datum = datum->next;
1713         }
1714 }
1715
1716 static int security_compute_sid(struct selinux_state *state,
1717                                 u32 ssid,
1718                                 u32 tsid,
1719                                 u16 orig_tclass,
1720                                 u32 specified,
1721                                 const char *objname,
1722                                 u32 *out_sid,
1723                                 bool kern)
1724 {
1725         struct selinux_policy *policy;
1726         struct policydb *policydb;
1727         struct sidtab *sidtab;
1728         struct class_datum *cladatum;
1729         struct context *scontext, *tcontext, newcontext;
1730         struct sidtab_entry *sentry, *tentry;
1731         struct avtab_key avkey;
1732         struct avtab_datum *avdatum;
1733         struct avtab_node *node;
1734         u16 tclass;
1735         int rc = 0;
1736         bool sock;
1737
1738         if (!selinux_initialized(state)) {
1739                 switch (orig_tclass) {
1740                 case SECCLASS_PROCESS: /* kernel value */
1741                         *out_sid = ssid;
1742                         break;
1743                 default:
1744                         *out_sid = tsid;
1745                         break;
1746                 }
1747                 goto out;
1748         }
1749
1750 retry:
1751         cladatum = NULL;
1752         context_init(&newcontext);
1753
1754         rcu_read_lock();
1755
1756         policy = rcu_dereference(state->policy);
1757
1758         if (kern) {
1759                 tclass = unmap_class(&policy->map, orig_tclass);
1760                 sock = security_is_socket_class(orig_tclass);
1761         } else {
1762                 tclass = orig_tclass;
1763                 sock = security_is_socket_class(map_class(&policy->map,
1764                                                           tclass));
1765         }
1766
1767         policydb = &policy->policydb;
1768         sidtab = policy->sidtab;
1769
1770         sentry = sidtab_search_entry(sidtab, ssid);
1771         if (!sentry) {
1772                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1773                        __func__, ssid);
1774                 rc = -EINVAL;
1775                 goto out_unlock;
1776         }
1777         tentry = sidtab_search_entry(sidtab, tsid);
1778         if (!tentry) {
1779                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1780                        __func__, tsid);
1781                 rc = -EINVAL;
1782                 goto out_unlock;
1783         }
1784
1785         scontext = &sentry->context;
1786         tcontext = &tentry->context;
1787
1788         if (tclass && tclass <= policydb->p_classes.nprim)
1789                 cladatum = policydb->class_val_to_struct[tclass - 1];
1790
1791         /* Set the user identity. */
1792         switch (specified) {
1793         case AVTAB_TRANSITION:
1794         case AVTAB_CHANGE:
1795                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1796                         newcontext.user = tcontext->user;
1797                 } else {
1798                         /* notice this gets both DEFAULT_SOURCE and unset */
1799                         /* Use the process user identity. */
1800                         newcontext.user = scontext->user;
1801                 }
1802                 break;
1803         case AVTAB_MEMBER:
1804                 /* Use the related object owner. */
1805                 newcontext.user = tcontext->user;
1806                 break;
1807         }
1808
1809         /* Set the role to default values. */
1810         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1811                 newcontext.role = scontext->role;
1812         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1813                 newcontext.role = tcontext->role;
1814         } else {
1815                 if ((tclass == policydb->process_class) || sock)
1816                         newcontext.role = scontext->role;
1817                 else
1818                         newcontext.role = OBJECT_R_VAL;
1819         }
1820
1821         /* Set the type to default values. */
1822         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1823                 newcontext.type = scontext->type;
1824         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1825                 newcontext.type = tcontext->type;
1826         } else {
1827                 if ((tclass == policydb->process_class) || sock) {
1828                         /* Use the type of process. */
1829                         newcontext.type = scontext->type;
1830                 } else {
1831                         /* Use the type of the related object. */
1832                         newcontext.type = tcontext->type;
1833                 }
1834         }
1835
1836         /* Look for a type transition/member/change rule. */
1837         avkey.source_type = scontext->type;
1838         avkey.target_type = tcontext->type;
1839         avkey.target_class = tclass;
1840         avkey.specified = specified;
1841         avdatum = avtab_search(&policydb->te_avtab, &avkey);
1842
1843         /* If no permanent rule, also check for enabled conditional rules */
1844         if (!avdatum) {
1845                 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1846                 for (; node; node = avtab_search_node_next(node, specified)) {
1847                         if (node->key.specified & AVTAB_ENABLED) {
1848                                 avdatum = &node->datum;
1849                                 break;
1850                         }
1851                 }
1852         }
1853
1854         if (avdatum) {
1855                 /* Use the type from the type transition/member/change rule. */
1856                 newcontext.type = avdatum->u.data;
1857         }
1858
1859         /* if we have a objname this is a file trans check so check those rules */
1860         if (objname)
1861                 filename_compute_type(policydb, &newcontext, scontext->type,
1862                                       tcontext->type, tclass, objname);
1863
1864         /* Check for class-specific changes. */
1865         if (specified & AVTAB_TRANSITION) {
1866                 /* Look for a role transition rule. */
1867                 struct role_trans_datum *rtd;
1868                 struct role_trans_key rtk = {
1869                         .role = scontext->role,
1870                         .type = tcontext->type,
1871                         .tclass = tclass,
1872                 };
1873
1874                 rtd = policydb_roletr_search(policydb, &rtk);
1875                 if (rtd)
1876                         newcontext.role = rtd->new_role;
1877         }
1878
1879         /* Set the MLS attributes.
1880            This is done last because it may allocate memory. */
1881         rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1882                              &newcontext, sock);
1883         if (rc)
1884                 goto out_unlock;
1885
1886         /* Check the validity of the context. */
1887         if (!policydb_context_isvalid(policydb, &newcontext)) {
1888                 rc = compute_sid_handle_invalid_context(state, policy, sentry,
1889                                                         tentry, tclass,
1890                                                         &newcontext);
1891                 if (rc)
1892                         goto out_unlock;
1893         }
1894         /* Obtain the sid for the context. */
1895         rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1896         if (rc == -ESTALE) {
1897                 rcu_read_unlock();
1898                 context_destroy(&newcontext);
1899                 goto retry;
1900         }
1901 out_unlock:
1902         rcu_read_unlock();
1903         context_destroy(&newcontext);
1904 out:
1905         return rc;
1906 }
1907
1908 /**
1909  * security_transition_sid - Compute the SID for a new subject/object.
1910  * @ssid: source security identifier
1911  * @tsid: target security identifier
1912  * @tclass: target security class
1913  * @out_sid: security identifier for new subject/object
1914  *
1915  * Compute a SID to use for labeling a new subject or object in the
1916  * class @tclass based on a SID pair (@ssid, @tsid).
1917  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1918  * if insufficient memory is available, or %0 if the new SID was
1919  * computed successfully.
1920  */
1921 int security_transition_sid(struct selinux_state *state,
1922                             u32 ssid, u32 tsid, u16 tclass,
1923                             const struct qstr *qstr, u32 *out_sid)
1924 {
1925         return security_compute_sid(state, ssid, tsid, tclass,
1926                                     AVTAB_TRANSITION,
1927                                     qstr ? qstr->name : NULL, out_sid, true);
1928 }
1929
1930 int security_transition_sid_user(struct selinux_state *state,
1931                                  u32 ssid, u32 tsid, u16 tclass,
1932                                  const char *objname, u32 *out_sid)
1933 {
1934         return security_compute_sid(state, ssid, tsid, tclass,
1935                                     AVTAB_TRANSITION,
1936                                     objname, out_sid, false);
1937 }
1938
1939 /**
1940  * security_member_sid - Compute the SID for member selection.
1941  * @ssid: source security identifier
1942  * @tsid: target security identifier
1943  * @tclass: target security class
1944  * @out_sid: security identifier for selected member
1945  *
1946  * Compute a SID to use when selecting a member of a polyinstantiated
1947  * object of class @tclass based on a SID pair (@ssid, @tsid).
1948  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1949  * if insufficient memory is available, or %0 if the SID was
1950  * computed successfully.
1951  */
1952 int security_member_sid(struct selinux_state *state,
1953                         u32 ssid,
1954                         u32 tsid,
1955                         u16 tclass,
1956                         u32 *out_sid)
1957 {
1958         return security_compute_sid(state, ssid, tsid, tclass,
1959                                     AVTAB_MEMBER, NULL,
1960                                     out_sid, false);
1961 }
1962
1963 /**
1964  * security_change_sid - Compute the SID for object relabeling.
1965  * @ssid: source security identifier
1966  * @tsid: target security identifier
1967  * @tclass: target security class
1968  * @out_sid: security identifier for selected member
1969  *
1970  * Compute a SID to use for relabeling an object of class @tclass
1971  * based on a SID pair (@ssid, @tsid).
1972  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1973  * if insufficient memory is available, or %0 if the SID was
1974  * computed successfully.
1975  */
1976 int security_change_sid(struct selinux_state *state,
1977                         u32 ssid,
1978                         u32 tsid,
1979                         u16 tclass,
1980                         u32 *out_sid)
1981 {
1982         return security_compute_sid(state,
1983                                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1984                                     out_sid, false);
1985 }
1986
1987 static inline int convert_context_handle_invalid_context(
1988         struct selinux_state *state,
1989         struct policydb *policydb,
1990         struct context *context)
1991 {
1992         char *s;
1993         u32 len;
1994
1995         if (enforcing_enabled(state))
1996                 return -EINVAL;
1997
1998         if (!context_struct_to_string(policydb, context, &s, &len)) {
1999                 pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
2000                         s);
2001                 kfree(s);
2002         }
2003         return 0;
2004 }
2005
2006 /*
2007  * Convert the values in the security context
2008  * structure `oldc' from the values specified
2009  * in the policy `p->oldp' to the values specified
2010  * in the policy `p->newp', storing the new context
2011  * in `newc'.  Verify that the context is valid
2012  * under the new policy.
2013  */
2014 static int convert_context(struct context *oldc, struct context *newc, void *p,
2015                            gfp_t gfp_flags)
2016 {
2017         struct convert_context_args *args;
2018         struct ocontext *oc;
2019         struct role_datum *role;
2020         struct type_datum *typdatum;
2021         struct user_datum *usrdatum;
2022         char *s;
2023         u32 len;
2024         int rc;
2025
2026         args = p;
2027
2028         if (oldc->str) {
2029                 s = kstrdup(oldc->str, gfp_flags);
2030                 if (!s)
2031                         return -ENOMEM;
2032
2033                 rc = string_to_context_struct(args->newp, NULL, s,
2034                                               newc, SECSID_NULL);
2035                 if (rc == -EINVAL) {
2036                         /*
2037                          * Retain string representation for later mapping.
2038                          *
2039                          * IMPORTANT: We need to copy the contents of oldc->str
2040                          * back into s again because string_to_context_struct()
2041                          * may have garbled it.
2042                          */
2043                         memcpy(s, oldc->str, oldc->len);
2044                         context_init(newc);
2045                         newc->str = s;
2046                         newc->len = oldc->len;
2047                         return 0;
2048                 }
2049                 kfree(s);
2050                 if (rc) {
2051                         /* Other error condition, e.g. ENOMEM. */
2052                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
2053                                oldc->str, -rc);
2054                         return rc;
2055                 }
2056                 pr_info("SELinux:  Context %s became valid (mapped).\n",
2057                         oldc->str);
2058                 return 0;
2059         }
2060
2061         context_init(newc);
2062
2063         /* Convert the user. */
2064         rc = -EINVAL;
2065         usrdatum = symtab_search(&args->newp->p_users,
2066                                  sym_name(args->oldp,
2067                                           SYM_USERS, oldc->user - 1));
2068         if (!usrdatum)
2069                 goto bad;
2070         newc->user = usrdatum->value;
2071
2072         /* Convert the role. */
2073         rc = -EINVAL;
2074         role = symtab_search(&args->newp->p_roles,
2075                              sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2076         if (!role)
2077                 goto bad;
2078         newc->role = role->value;
2079
2080         /* Convert the type. */
2081         rc = -EINVAL;
2082         typdatum = symtab_search(&args->newp->p_types,
2083                                  sym_name(args->oldp,
2084                                           SYM_TYPES, oldc->type - 1));
2085         if (!typdatum)
2086                 goto bad;
2087         newc->type = typdatum->value;
2088
2089         /* Convert the MLS fields if dealing with MLS policies */
2090         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2091                 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2092                 if (rc)
2093                         goto bad;
2094         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2095                 /*
2096                  * Switching between non-MLS and MLS policy:
2097                  * ensure that the MLS fields of the context for all
2098                  * existing entries in the sidtab are filled in with a
2099                  * suitable default value, likely taken from one of the
2100                  * initial SIDs.
2101                  */
2102                 oc = args->newp->ocontexts[OCON_ISID];
2103                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2104                         oc = oc->next;
2105                 rc = -EINVAL;
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,
2120                                                         oldc);
2121                 if (rc)
2122                         goto bad;
2123         }
2124
2125         return 0;
2126 bad:
2127         /* Map old representation to string and save it. */
2128         rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2129         if (rc)
2130                 return rc;
2131         context_destroy(newc);
2132         newc->str = s;
2133         newc->len = len;
2134         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2135                 newc->str);
2136         return 0;
2137 }
2138
2139 static void security_load_policycaps(struct selinux_state *state,
2140                                 struct selinux_policy *policy)
2141 {
2142         struct policydb *p;
2143         unsigned int i;
2144         struct ebitmap_node *node;
2145
2146         p = &policy->policydb;
2147
2148         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2149                 WRITE_ONCE(state->policycap[i],
2150                         ebitmap_get_bit(&p->policycaps, i));
2151
2152         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2153                 pr_info("SELinux:  policy capability %s=%d\n",
2154                         selinux_policycap_names[i],
2155                         ebitmap_get_bit(&p->policycaps, i));
2156
2157         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2158                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2159                         pr_info("SELinux:  unknown policy capability %u\n",
2160                                 i);
2161         }
2162 }
2163
2164 static int security_preserve_bools(struct selinux_policy *oldpolicy,
2165                                 struct selinux_policy *newpolicy);
2166
2167 static void selinux_policy_free(struct selinux_policy *policy)
2168 {
2169         if (!policy)
2170                 return;
2171
2172         sidtab_destroy(policy->sidtab);
2173         kfree(policy->map.mapping);
2174         policydb_destroy(&policy->policydb);
2175         kfree(policy->sidtab);
2176         kfree(policy);
2177 }
2178
2179 static void selinux_policy_cond_free(struct selinux_policy *policy)
2180 {
2181         cond_policydb_destroy_dup(&policy->policydb);
2182         kfree(policy);
2183 }
2184
2185 void selinux_policy_cancel(struct selinux_state *state,
2186                            struct selinux_load_state *load_state)
2187 {
2188         struct selinux_policy *oldpolicy;
2189
2190         oldpolicy = rcu_dereference_protected(state->policy,
2191                                         lockdep_is_held(&state->policy_mutex));
2192
2193         sidtab_cancel_convert(oldpolicy->sidtab);
2194         selinux_policy_free(load_state->policy);
2195         kfree(load_state->convert_data);
2196 }
2197
2198 static void selinux_notify_policy_change(struct selinux_state *state,
2199                                         u32 seqno)
2200 {
2201         /* Flush external caches and notify userspace of policy load */
2202         avc_ss_reset(state->avc, seqno);
2203         selnl_notify_policyload(seqno);
2204         selinux_status_update_policyload(state, seqno);
2205         selinux_netlbl_cache_invalidate();
2206         selinux_xfrm_notify_policyload();
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  * @data: binary policy data
2268  * @len: length of data in bytes
2269  *
2270  * Load a new set of security policy configuration data,
2271  * validate it and convert the SID table as necessary.
2272  * This function will flush the access vector cache after
2273  * loading the new policy.
2274  */
2275 int security_load_policy(struct selinux_state *state, void *data, size_t len,
2276                          struct selinux_load_state *load_state)
2277 {
2278         struct selinux_policy *newpolicy, *oldpolicy;
2279         struct selinux_policy_convert_data *convert_data;
2280         int rc = 0;
2281         struct policy_file file = { data, len }, *fp = &file;
2282
2283         newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2284         if (!newpolicy)
2285                 return -ENOMEM;
2286
2287         newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2288         if (!newpolicy->sidtab) {
2289                 rc = -ENOMEM;
2290                 goto err_policy;
2291         }
2292
2293         rc = policydb_read(&newpolicy->policydb, fp);
2294         if (rc)
2295                 goto err_sidtab;
2296
2297         newpolicy->policydb.len = len;
2298         rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2299                                 &newpolicy->map);
2300         if (rc)
2301                 goto err_policydb;
2302
2303         rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2304         if (rc) {
2305                 pr_err("SELinux:  unable to load the initial SIDs\n");
2306                 goto err_mapping;
2307         }
2308
2309         if (!selinux_initialized(state)) {
2310                 /* First policy load, so no need to preserve state from old policy */
2311                 load_state->policy = newpolicy;
2312                 load_state->convert_data = NULL;
2313                 return 0;
2314         }
2315
2316         oldpolicy = rcu_dereference_protected(state->policy,
2317                                         lockdep_is_held(&state->policy_mutex));
2318
2319         /* Preserve active boolean values from the old policy */
2320         rc = security_preserve_bools(oldpolicy, newpolicy);
2321         if (rc) {
2322                 pr_err("SELinux:  unable to preserve booleans\n");
2323                 goto err_free_isids;
2324         }
2325
2326         convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2327         if (!convert_data) {
2328                 rc = -ENOMEM;
2329                 goto err_free_isids;
2330         }
2331
2332         /*
2333          * Convert the internal representations of contexts
2334          * in the new SID table.
2335          */
2336         convert_data->args.state = state;
2337         convert_data->args.oldp = &oldpolicy->policydb;
2338         convert_data->args.newp = &newpolicy->policydb;
2339
2340         convert_data->sidtab_params.func = convert_context;
2341         convert_data->sidtab_params.args = &convert_data->args;
2342         convert_data->sidtab_params.target = newpolicy->sidtab;
2343
2344         rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2345         if (rc) {
2346                 pr_err("SELinux:  unable to convert the internal"
2347                         " representation of contexts in the new SID"
2348                         " table\n");
2349                 goto err_free_convert_data;
2350         }
2351
2352         load_state->policy = newpolicy;
2353         load_state->convert_data = convert_data;
2354         return 0;
2355
2356 err_free_convert_data:
2357         kfree(convert_data);
2358 err_free_isids:
2359         sidtab_destroy(newpolicy->sidtab);
2360 err_mapping:
2361         kfree(newpolicy->map.mapping);
2362 err_policydb:
2363         policydb_destroy(&newpolicy->policydb);
2364 err_sidtab:
2365         kfree(newpolicy->sidtab);
2366 err_policy:
2367         kfree(newpolicy);
2368
2369         return rc;
2370 }
2371
2372 /**
2373  * ocontext_to_sid - Helper to safely get sid for an ocontext
2374  * @sidtab: SID table
2375  * @c: ocontext structure
2376  * @index: index of the context entry (0 or 1)
2377  * @out_sid: pointer to the resulting SID value
2378  *
2379  * For all ocontexts except OCON_ISID the SID fields are populated
2380  * on-demand when needed. Since updating the SID value is an SMP-sensitive
2381  * operation, this helper must be used to do that safely.
2382  *
2383  * WARNING: This function may return -ESTALE, indicating that the caller
2384  * must retry the operation after re-acquiring the policy pointer!
2385  */
2386 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2387                            size_t index, u32 *out_sid)
2388 {
2389         int rc;
2390         u32 sid;
2391
2392         /* Ensure the associated sidtab entry is visible to this thread. */
2393         sid = smp_load_acquire(&c->sid[index]);
2394         if (!sid) {
2395                 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2396                 if (rc)
2397                         return rc;
2398
2399                 /*
2400                  * Ensure the new sidtab entry is visible to other threads
2401                  * when they see the SID.
2402                  */
2403                 smp_store_release(&c->sid[index], sid);
2404         }
2405         *out_sid = sid;
2406         return 0;
2407 }
2408
2409 /**
2410  * security_port_sid - Obtain the SID for a port.
2411  * @protocol: protocol number
2412  * @port: port number
2413  * @out_sid: security identifier
2414  */
2415 int security_port_sid(struct selinux_state *state,
2416                       u8 protocol, u16 port, u32 *out_sid)
2417 {
2418         struct selinux_policy *policy;
2419         struct policydb *policydb;
2420         struct sidtab *sidtab;
2421         struct ocontext *c;
2422         int rc;
2423
2424         if (!selinux_initialized(state)) {
2425                 *out_sid = SECINITSID_PORT;
2426                 return 0;
2427         }
2428
2429 retry:
2430         rc = 0;
2431         rcu_read_lock();
2432         policy = rcu_dereference(state->policy);
2433         policydb = &policy->policydb;
2434         sidtab = policy->sidtab;
2435
2436         c = policydb->ocontexts[OCON_PORT];
2437         while (c) {
2438                 if (c->u.port.protocol == protocol &&
2439                     c->u.port.low_port <= port &&
2440                     c->u.port.high_port >= port)
2441                         break;
2442                 c = c->next;
2443         }
2444
2445         if (c) {
2446                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2447                 if (rc == -ESTALE) {
2448                         rcu_read_unlock();
2449                         goto retry;
2450                 }
2451                 if (rc)
2452                         goto out;
2453         } else {
2454                 *out_sid = SECINITSID_PORT;
2455         }
2456
2457 out:
2458         rcu_read_unlock();
2459         return rc;
2460 }
2461
2462 /**
2463  * security_pkey_sid - Obtain the SID for a pkey.
2464  * @subnet_prefix: Subnet Prefix
2465  * @pkey_num: pkey number
2466  * @out_sid: security identifier
2467  */
2468 int security_ib_pkey_sid(struct selinux_state *state,
2469                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2470 {
2471         struct selinux_policy *policy;
2472         struct policydb *policydb;
2473         struct sidtab *sidtab;
2474         struct ocontext *c;
2475         int rc;
2476
2477         if (!selinux_initialized(state)) {
2478                 *out_sid = SECINITSID_UNLABELED;
2479                 return 0;
2480         }
2481
2482 retry:
2483         rc = 0;
2484         rcu_read_lock();
2485         policy = rcu_dereference(state->policy);
2486         policydb = &policy->policydb;
2487         sidtab = policy->sidtab;
2488
2489         c = policydb->ocontexts[OCON_IBPKEY];
2490         while (c) {
2491                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2492                     c->u.ibpkey.high_pkey >= pkey_num &&
2493                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2494                         break;
2495
2496                 c = c->next;
2497         }
2498
2499         if (c) {
2500                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2501                 if (rc == -ESTALE) {
2502                         rcu_read_unlock();
2503                         goto retry;
2504                 }
2505                 if (rc)
2506                         goto out;
2507         } else
2508                 *out_sid = SECINITSID_UNLABELED;
2509
2510 out:
2511         rcu_read_unlock();
2512         return rc;
2513 }
2514
2515 /**
2516  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2517  * @dev_name: device name
2518  * @port: port number
2519  * @out_sid: security identifier
2520  */
2521 int security_ib_endport_sid(struct selinux_state *state,
2522                             const char *dev_name, u8 port_num, u32 *out_sid)
2523 {
2524         struct selinux_policy *policy;
2525         struct policydb *policydb;
2526         struct sidtab *sidtab;
2527         struct ocontext *c;
2528         int rc;
2529
2530         if (!selinux_initialized(state)) {
2531                 *out_sid = SECINITSID_UNLABELED;
2532                 return 0;
2533         }
2534
2535 retry:
2536         rc = 0;
2537         rcu_read_lock();
2538         policy = rcu_dereference(state->policy);
2539         policydb = &policy->policydb;
2540         sidtab = policy->sidtab;
2541
2542         c = policydb->ocontexts[OCON_IBENDPORT];
2543         while (c) {
2544                 if (c->u.ibendport.port == port_num &&
2545                     !strncmp(c->u.ibendport.dev_name,
2546                              dev_name,
2547                              IB_DEVICE_NAME_MAX))
2548                         break;
2549
2550                 c = c->next;
2551         }
2552
2553         if (c) {
2554                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2555                 if (rc == -ESTALE) {
2556                         rcu_read_unlock();
2557                         goto retry;
2558                 }
2559                 if (rc)
2560                         goto out;
2561         } else
2562                 *out_sid = SECINITSID_UNLABELED;
2563
2564 out:
2565         rcu_read_unlock();
2566         return rc;
2567 }
2568
2569 /**
2570  * security_netif_sid - Obtain the SID for a network interface.
2571  * @name: interface name
2572  * @if_sid: interface SID
2573  */
2574 int security_netif_sid(struct selinux_state *state,
2575                        char *name, u32 *if_sid)
2576 {
2577         struct selinux_policy *policy;
2578         struct policydb *policydb;
2579         struct sidtab *sidtab;
2580         int rc;
2581         struct ocontext *c;
2582
2583         if (!selinux_initialized(state)) {
2584                 *if_sid = SECINITSID_NETIF;
2585                 return 0;
2586         }
2587
2588 retry:
2589         rc = 0;
2590         rcu_read_lock();
2591         policy = rcu_dereference(state->policy);
2592         policydb = &policy->policydb;
2593         sidtab = policy->sidtab;
2594
2595         c = policydb->ocontexts[OCON_NETIF];
2596         while (c) {
2597                 if (strcmp(name, c->u.name) == 0)
2598                         break;
2599                 c = c->next;
2600         }
2601
2602         if (c) {
2603                 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2604                 if (rc == -ESTALE) {
2605                         rcu_read_unlock();
2606                         goto retry;
2607                 }
2608                 if (rc)
2609                         goto out;
2610         } else
2611                 *if_sid = SECINITSID_NETIF;
2612
2613 out:
2614         rcu_read_unlock();
2615         return rc;
2616 }
2617
2618 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2619 {
2620         int i, fail = 0;
2621
2622         for (i = 0; i < 4; i++)
2623                 if (addr[i] != (input[i] & mask[i])) {
2624                         fail = 1;
2625                         break;
2626                 }
2627
2628         return !fail;
2629 }
2630
2631 /**
2632  * security_node_sid - Obtain the SID for a node (host).
2633  * @domain: communication domain aka address family
2634  * @addrp: address
2635  * @addrlen: address length in bytes
2636  * @out_sid: security identifier
2637  */
2638 int security_node_sid(struct selinux_state *state,
2639                       u16 domain,
2640                       void *addrp,
2641                       u32 addrlen,
2642                       u32 *out_sid)
2643 {
2644         struct selinux_policy *policy;
2645         struct policydb *policydb;
2646         struct sidtab *sidtab;
2647         int rc;
2648         struct ocontext *c;
2649
2650         if (!selinux_initialized(state)) {
2651                 *out_sid = SECINITSID_NODE;
2652                 return 0;
2653         }
2654
2655 retry:
2656         rcu_read_lock();
2657         policy = rcu_dereference(state->policy);
2658         policydb = &policy->policydb;
2659         sidtab = policy->sidtab;
2660
2661         switch (domain) {
2662         case AF_INET: {
2663                 u32 addr;
2664
2665                 rc = -EINVAL;
2666                 if (addrlen != sizeof(u32))
2667                         goto out;
2668
2669                 addr = *((u32 *)addrp);
2670
2671                 c = policydb->ocontexts[OCON_NODE];
2672                 while (c) {
2673                         if (c->u.node.addr == (addr & c->u.node.mask))
2674                                 break;
2675                         c = c->next;
2676                 }
2677                 break;
2678         }
2679
2680         case AF_INET6:
2681                 rc = -EINVAL;
2682                 if (addrlen != sizeof(u64) * 2)
2683                         goto out;
2684                 c = policydb->ocontexts[OCON_NODE6];
2685                 while (c) {
2686                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2687                                                 c->u.node6.mask))
2688                                 break;
2689                         c = c->next;
2690                 }
2691                 break;
2692
2693         default:
2694                 rc = 0;
2695                 *out_sid = SECINITSID_NODE;
2696                 goto out;
2697         }
2698
2699         if (c) {
2700                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2701                 if (rc == -ESTALE) {
2702                         rcu_read_unlock();
2703                         goto retry;
2704                 }
2705                 if (rc)
2706                         goto out;
2707         } else {
2708                 *out_sid = SECINITSID_NODE;
2709         }
2710
2711         rc = 0;
2712 out:
2713         rcu_read_unlock();
2714         return rc;
2715 }
2716
2717 #define SIDS_NEL 25
2718
2719 /**
2720  * security_get_user_sids - Obtain reachable SIDs for a user.
2721  * @fromsid: starting SID
2722  * @username: username
2723  * @sids: array of reachable SIDs for user
2724  * @nel: number of elements in @sids
2725  *
2726  * Generate the set of SIDs for legal security contexts
2727  * for a given user that can be reached by @fromsid.
2728  * Set *@sids to point to a dynamically allocated
2729  * array containing the set of SIDs.  Set *@nel to the
2730  * number of elements in the array.
2731  */
2732
2733 int security_get_user_sids(struct selinux_state *state,
2734                            u32 fromsid,
2735                            char *username,
2736                            u32 **sids,
2737                            u32 *nel)
2738 {
2739         struct selinux_policy *policy;
2740         struct policydb *policydb;
2741         struct sidtab *sidtab;
2742         struct context *fromcon, usercon;
2743         u32 *mysids = NULL, *mysids2, sid;
2744         u32 i, j, mynel, maxnel = SIDS_NEL;
2745         struct user_datum *user;
2746         struct role_datum *role;
2747         struct ebitmap_node *rnode, *tnode;
2748         int rc;
2749
2750         *sids = NULL;
2751         *nel = 0;
2752
2753         if (!selinux_initialized(state))
2754                 return 0;
2755
2756         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2757         if (!mysids)
2758                 return -ENOMEM;
2759
2760 retry:
2761         mynel = 0;
2762         rcu_read_lock();
2763         policy = rcu_dereference(state->policy);
2764         policydb = &policy->policydb;
2765         sidtab = policy->sidtab;
2766
2767         context_init(&usercon);
2768
2769         rc = -EINVAL;
2770         fromcon = sidtab_search(sidtab, fromsid);
2771         if (!fromcon)
2772                 goto out_unlock;
2773
2774         rc = -EINVAL;
2775         user = symtab_search(&policydb->p_users, username);
2776         if (!user)
2777                 goto out_unlock;
2778
2779         usercon.user = user->value;
2780
2781         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2782                 role = policydb->role_val_to_struct[i];
2783                 usercon.role = i + 1;
2784                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2785                         usercon.type = j + 1;
2786
2787                         if (mls_setup_user_range(policydb, fromcon, user,
2788                                                  &usercon))
2789                                 continue;
2790
2791                         rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2792                         if (rc == -ESTALE) {
2793                                 rcu_read_unlock();
2794                                 goto retry;
2795                         }
2796                         if (rc)
2797                                 goto out_unlock;
2798                         if (mynel < maxnel) {
2799                                 mysids[mynel++] = sid;
2800                         } else {
2801                                 rc = -ENOMEM;
2802                                 maxnel += SIDS_NEL;
2803                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2804                                 if (!mysids2)
2805                                         goto out_unlock;
2806                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2807                                 kfree(mysids);
2808                                 mysids = mysids2;
2809                                 mysids[mynel++] = sid;
2810                         }
2811                 }
2812         }
2813         rc = 0;
2814 out_unlock:
2815         rcu_read_unlock();
2816         if (rc || !mynel) {
2817                 kfree(mysids);
2818                 return rc;
2819         }
2820
2821         rc = -ENOMEM;
2822         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2823         if (!mysids2) {
2824                 kfree(mysids);
2825                 return rc;
2826         }
2827         for (i = 0, j = 0; i < mynel; i++) {
2828                 struct av_decision dummy_avd;
2829                 rc = avc_has_perm_noaudit(state,
2830                                           fromsid, mysids[i],
2831                                           SECCLASS_PROCESS, /* kernel value */
2832                                           PROCESS__TRANSITION, AVC_STRICT,
2833                                           &dummy_avd);
2834                 if (!rc)
2835                         mysids2[j++] = mysids[i];
2836                 cond_resched();
2837         }
2838         kfree(mysids);
2839         *sids = mysids2;
2840         *nel = j;
2841         return 0;
2842 }
2843
2844 /**
2845  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2846  * @fstype: filesystem type
2847  * @path: path from root of mount
2848  * @sclass: file security class
2849  * @sid: SID for path
2850  *
2851  * Obtain a SID to use for a file in a filesystem that
2852  * cannot support xattr or use a fixed labeling behavior like
2853  * transition SIDs or task SIDs.
2854  *
2855  * WARNING: This function may return -ESTALE, indicating that the caller
2856  * must retry the operation after re-acquiring the policy pointer!
2857  */
2858 static inline int __security_genfs_sid(struct selinux_policy *policy,
2859                                        const char *fstype,
2860                                        char *path,
2861                                        u16 orig_sclass,
2862                                        u32 *sid)
2863 {
2864         struct policydb *policydb = &policy->policydb;
2865         struct sidtab *sidtab = policy->sidtab;
2866         int len;
2867         u16 sclass;
2868         struct genfs *genfs;
2869         struct ocontext *c;
2870         int cmp = 0;
2871
2872         while (path[0] == '/' && path[1] == '/')
2873                 path++;
2874
2875         sclass = unmap_class(&policy->map, orig_sclass);
2876         *sid = SECINITSID_UNLABELED;
2877
2878         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2879                 cmp = strcmp(fstype, genfs->fstype);
2880                 if (cmp <= 0)
2881                         break;
2882         }
2883
2884         if (!genfs || cmp)
2885                 return -ENOENT;
2886
2887         for (c = genfs->head; c; c = c->next) {
2888                 len = strlen(c->u.name);
2889                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2890                     (strncmp(c->u.name, path, len) == 0))
2891                         break;
2892         }
2893
2894         if (!c)
2895                 return -ENOENT;
2896
2897         return ocontext_to_sid(sidtab, c, 0, sid);
2898 }
2899
2900 /**
2901  * security_genfs_sid - Obtain a SID for a file in a filesystem
2902  * @fstype: filesystem type
2903  * @path: path from root of mount
2904  * @sclass: file security class
2905  * @sid: SID for path
2906  *
2907  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2908  * it afterward.
2909  */
2910 int security_genfs_sid(struct selinux_state *state,
2911                        const char *fstype,
2912                        char *path,
2913                        u16 orig_sclass,
2914                        u32 *sid)
2915 {
2916         struct selinux_policy *policy;
2917         int retval;
2918
2919         if (!selinux_initialized(state)) {
2920                 *sid = SECINITSID_UNLABELED;
2921                 return 0;
2922         }
2923
2924         do {
2925                 rcu_read_lock();
2926                 policy = rcu_dereference(state->policy);
2927                 retval = __security_genfs_sid(policy, fstype, path,
2928                                               orig_sclass, sid);
2929                 rcu_read_unlock();
2930         } while (retval == -ESTALE);
2931         return retval;
2932 }
2933
2934 int selinux_policy_genfs_sid(struct selinux_policy *policy,
2935                         const char *fstype,
2936                         char *path,
2937                         u16 orig_sclass,
2938                         u32 *sid)
2939 {
2940         /* no lock required, policy is not yet accessible by other threads */
2941         return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2942 }
2943
2944 /**
2945  * security_fs_use - Determine how to handle labeling for a filesystem.
2946  * @sb: superblock in question
2947  */
2948 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2949 {
2950         struct selinux_policy *policy;
2951         struct policydb *policydb;
2952         struct sidtab *sidtab;
2953         int rc;
2954         struct ocontext *c;
2955         struct superblock_security_struct *sbsec = sb->s_security;
2956         const char *fstype = sb->s_type->name;
2957
2958         if (!selinux_initialized(state)) {
2959                 sbsec->behavior = SECURITY_FS_USE_NONE;
2960                 sbsec->sid = SECINITSID_UNLABELED;
2961                 return 0;
2962         }
2963
2964 retry:
2965         rc = 0;
2966         rcu_read_lock();
2967         policy = rcu_dereference(state->policy);
2968         policydb = &policy->policydb;
2969         sidtab = policy->sidtab;
2970
2971         c = policydb->ocontexts[OCON_FSUSE];
2972         while (c) {
2973                 if (strcmp(fstype, c->u.name) == 0)
2974                         break;
2975                 c = c->next;
2976         }
2977
2978         if (c) {
2979                 sbsec->behavior = c->v.behavior;
2980                 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2981                 if (rc == -ESTALE) {
2982                         rcu_read_unlock();
2983                         goto retry;
2984                 }
2985                 if (rc)
2986                         goto out;
2987         } else {
2988                 rc = __security_genfs_sid(policy, fstype, "/",
2989                                         SECCLASS_DIR, &sbsec->sid);
2990                 if (rc == -ESTALE) {
2991                         rcu_read_unlock();
2992                         goto retry;
2993                 }
2994                 if (rc) {
2995                         sbsec->behavior = SECURITY_FS_USE_NONE;
2996                         rc = 0;
2997                 } else {
2998                         sbsec->behavior = SECURITY_FS_USE_GENFS;
2999                 }
3000         }
3001
3002 out:
3003         rcu_read_unlock();
3004         return rc;
3005 }
3006
3007 int security_get_bools(struct selinux_policy *policy,
3008                        u32 *len, char ***names, int **values)
3009 {
3010         struct policydb *policydb;
3011         u32 i;
3012         int rc;
3013
3014         policydb = &policy->policydb;
3015
3016         *names = NULL;
3017         *values = NULL;
3018
3019         rc = 0;
3020         *len = policydb->p_bools.nprim;
3021         if (!*len)
3022                 goto out;
3023
3024         rc = -ENOMEM;
3025         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3026         if (!*names)
3027                 goto err;
3028
3029         rc = -ENOMEM;
3030         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3031         if (!*values)
3032                 goto err;
3033
3034         for (i = 0; i < *len; i++) {
3035                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3036
3037                 rc = -ENOMEM;
3038                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3039                                       GFP_ATOMIC);
3040                 if (!(*names)[i])
3041                         goto err;
3042         }
3043         rc = 0;
3044 out:
3045         return rc;
3046 err:
3047         if (*names) {
3048                 for (i = 0; i < *len; i++)
3049                         kfree((*names)[i]);
3050                 kfree(*names);
3051         }
3052         kfree(*values);
3053         *len = 0;
3054         *names = NULL;
3055         *values = NULL;
3056         goto out;
3057 }
3058
3059
3060 int security_set_bools(struct selinux_state *state, u32 len, int *values)
3061 {
3062         struct selinux_policy *newpolicy, *oldpolicy;
3063         int rc;
3064         u32 i, seqno = 0;
3065
3066         if (!selinux_initialized(state))
3067                 return -EINVAL;
3068
3069         oldpolicy = rcu_dereference_protected(state->policy,
3070                                         lockdep_is_held(&state->policy_mutex));
3071
3072         /* Consistency check on number of booleans, should never fail */
3073         if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3074                 return -EINVAL;
3075
3076         newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3077         if (!newpolicy)
3078                 return -ENOMEM;
3079
3080         /*
3081          * Deep copy only the parts of the policydb that might be
3082          * modified as a result of changing booleans.
3083          */
3084         rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3085         if (rc) {
3086                 kfree(newpolicy);
3087                 return -ENOMEM;
3088         }
3089
3090         /* Update the boolean states in the copy */
3091         for (i = 0; i < len; i++) {
3092                 int new_state = !!values[i];
3093                 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3094
3095                 if (new_state != old_state) {
3096                         audit_log(audit_context(), GFP_ATOMIC,
3097                                 AUDIT_MAC_CONFIG_CHANGE,
3098                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3099                                 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3100                                 new_state,
3101                                 old_state,
3102                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3103                                 audit_get_sessionid(current));
3104                         newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3105                 }
3106         }
3107
3108         /* Re-evaluate the conditional rules in the copy */
3109         evaluate_cond_nodes(&newpolicy->policydb);
3110
3111         /* Set latest granting seqno for new policy */
3112         newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3113         seqno = newpolicy->latest_granting;
3114
3115         /* Install the new policy */
3116         rcu_assign_pointer(state->policy, newpolicy);
3117
3118         /*
3119          * Free the conditional portions of the old policydb
3120          * that were copied for the new policy, and the oldpolicy
3121          * structure itself but not what it references.
3122          */
3123         synchronize_rcu();
3124         selinux_policy_cond_free(oldpolicy);
3125
3126         /* Notify others of the policy change */
3127         selinux_notify_policy_change(state, seqno);
3128         return 0;
3129 }
3130
3131 int security_get_bool_value(struct selinux_state *state,
3132                             u32 index)
3133 {
3134         struct selinux_policy *policy;
3135         struct policydb *policydb;
3136         int rc;
3137         u32 len;
3138
3139         if (!selinux_initialized(state))
3140                 return 0;
3141
3142         rcu_read_lock();
3143         policy = rcu_dereference(state->policy);
3144         policydb = &policy->policydb;
3145
3146         rc = -EFAULT;
3147         len = policydb->p_bools.nprim;
3148         if (index >= len)
3149                 goto out;
3150
3151         rc = policydb->bool_val_to_struct[index]->state;
3152 out:
3153         rcu_read_unlock();
3154         return rc;
3155 }
3156
3157 static int security_preserve_bools(struct selinux_policy *oldpolicy,
3158                                 struct selinux_policy *newpolicy)
3159 {
3160         int rc, *bvalues = NULL;
3161         char **bnames = NULL;
3162         struct cond_bool_datum *booldatum;
3163         u32 i, nbools = 0;
3164
3165         rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3166         if (rc)
3167                 goto out;
3168         for (i = 0; i < nbools; i++) {
3169                 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3170                                         bnames[i]);
3171                 if (booldatum)
3172                         booldatum->state = bvalues[i];
3173         }
3174         evaluate_cond_nodes(&newpolicy->policydb);
3175
3176 out:
3177         if (bnames) {
3178                 for (i = 0; i < nbools; i++)
3179                         kfree(bnames[i]);
3180         }
3181         kfree(bnames);
3182         kfree(bvalues);
3183         return rc;
3184 }
3185
3186 /*
3187  * security_sid_mls_copy() - computes a new sid based on the given
3188  * sid and the mls portion of mls_sid.
3189  */
3190 int security_sid_mls_copy(struct selinux_state *state,
3191                           u32 sid, u32 mls_sid, u32 *new_sid)
3192 {
3193         struct selinux_policy *policy;
3194         struct policydb *policydb;
3195         struct sidtab *sidtab;
3196         struct context *context1;
3197         struct context *context2;
3198         struct context newcon;
3199         char *s;
3200         u32 len;
3201         int rc;
3202
3203         if (!selinux_initialized(state)) {
3204                 *new_sid = sid;
3205                 return 0;
3206         }
3207
3208 retry:
3209         rc = 0;
3210         context_init(&newcon);
3211
3212         rcu_read_lock();
3213         policy = rcu_dereference(state->policy);
3214         policydb = &policy->policydb;
3215         sidtab = policy->sidtab;
3216
3217         if (!policydb->mls_enabled) {
3218                 *new_sid = sid;
3219                 goto out_unlock;
3220         }
3221
3222         rc = -EINVAL;
3223         context1 = sidtab_search(sidtab, sid);
3224         if (!context1) {
3225                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3226                         __func__, sid);
3227                 goto out_unlock;
3228         }
3229
3230         rc = -EINVAL;
3231         context2 = sidtab_search(sidtab, mls_sid);
3232         if (!context2) {
3233                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3234                         __func__, mls_sid);
3235                 goto out_unlock;
3236         }
3237
3238         newcon.user = context1->user;
3239         newcon.role = context1->role;
3240         newcon.type = context1->type;
3241         rc = mls_context_cpy(&newcon, context2);
3242         if (rc)
3243                 goto out_unlock;
3244
3245         /* Check the validity of the new context. */
3246         if (!policydb_context_isvalid(policydb, &newcon)) {
3247                 rc = convert_context_handle_invalid_context(state, policydb,
3248                                                         &newcon);
3249                 if (rc) {
3250                         if (!context_struct_to_string(policydb, &newcon, &s,
3251                                                       &len)) {
3252                                 struct audit_buffer *ab;
3253
3254                                 ab = audit_log_start(audit_context(),
3255                                                      GFP_ATOMIC,
3256                                                      AUDIT_SELINUX_ERR);
3257                                 audit_log_format(ab,
3258                                                  "op=security_sid_mls_copy invalid_context=");
3259                                 /* don't record NUL with untrusted strings */
3260                                 audit_log_n_untrustedstring(ab, s, len - 1);
3261                                 audit_log_end(ab);
3262                                 kfree(s);
3263                         }
3264                         goto out_unlock;
3265                 }
3266         }
3267         rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3268         if (rc == -ESTALE) {
3269                 rcu_read_unlock();
3270                 context_destroy(&newcon);
3271                 goto retry;
3272         }
3273 out_unlock:
3274         rcu_read_unlock();
3275         context_destroy(&newcon);
3276         return rc;
3277 }
3278
3279 /**
3280  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3281  * @nlbl_sid: NetLabel SID
3282  * @nlbl_type: NetLabel labeling protocol type
3283  * @xfrm_sid: XFRM SID
3284  *
3285  * Description:
3286  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3287  * resolved into a single SID it is returned via @peer_sid and the function
3288  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3289  * returns a negative value.  A table summarizing the behavior is below:
3290  *
3291  *                                 | function return |      @sid
3292  *   ------------------------------+-----------------+-----------------
3293  *   no peer labels                |        0        |    SECSID_NULL
3294  *   single peer label             |        0        |    <peer_label>
3295  *   multiple, consistent labels   |        0        |    <peer_label>
3296  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3297  *
3298  */
3299 int security_net_peersid_resolve(struct selinux_state *state,
3300                                  u32 nlbl_sid, u32 nlbl_type,
3301                                  u32 xfrm_sid,
3302                                  u32 *peer_sid)
3303 {
3304         struct selinux_policy *policy;
3305         struct policydb *policydb;
3306         struct sidtab *sidtab;
3307         int rc;
3308         struct context *nlbl_ctx;
3309         struct context *xfrm_ctx;
3310
3311         *peer_sid = SECSID_NULL;
3312
3313         /* handle the common (which also happens to be the set of easy) cases
3314          * right away, these two if statements catch everything involving a
3315          * single or absent peer SID/label */
3316         if (xfrm_sid == SECSID_NULL) {
3317                 *peer_sid = nlbl_sid;
3318                 return 0;
3319         }
3320         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3321          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3322          * is present */
3323         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3324                 *peer_sid = xfrm_sid;
3325                 return 0;
3326         }
3327
3328         if (!selinux_initialized(state))
3329                 return 0;
3330
3331         rcu_read_lock();
3332         policy = rcu_dereference(state->policy);
3333         policydb = &policy->policydb;
3334         sidtab = policy->sidtab;
3335
3336         /*
3337          * We don't need to check initialized here since the only way both
3338          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3339          * security server was initialized and state->initialized was true.
3340          */
3341         if (!policydb->mls_enabled) {
3342                 rc = 0;
3343                 goto out;
3344         }
3345
3346         rc = -EINVAL;
3347         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3348         if (!nlbl_ctx) {
3349                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3350                        __func__, nlbl_sid);
3351                 goto out;
3352         }
3353         rc = -EINVAL;
3354         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3355         if (!xfrm_ctx) {
3356                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3357                        __func__, xfrm_sid);
3358                 goto out;
3359         }
3360         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3361         if (rc)
3362                 goto out;
3363
3364         /* at present NetLabel SIDs/labels really only carry MLS
3365          * information so if the MLS portion of the NetLabel SID
3366          * matches the MLS portion of the labeled XFRM SID/label
3367          * then pass along the XFRM SID as it is the most
3368          * expressive */
3369         *peer_sid = xfrm_sid;
3370 out:
3371         rcu_read_unlock();
3372         return rc;
3373 }
3374
3375 static int get_classes_callback(void *k, void *d, void *args)
3376 {
3377         struct class_datum *datum = d;
3378         char *name = k, **classes = args;
3379         int value = datum->value - 1;
3380
3381         classes[value] = kstrdup(name, GFP_ATOMIC);
3382         if (!classes[value])
3383                 return -ENOMEM;
3384
3385         return 0;
3386 }
3387
3388 int security_get_classes(struct selinux_policy *policy,
3389                          char ***classes, int *nclasses)
3390 {
3391         struct policydb *policydb;
3392         int rc;
3393
3394         policydb = &policy->policydb;
3395
3396         rc = -ENOMEM;
3397         *nclasses = policydb->p_classes.nprim;
3398         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3399         if (!*classes)
3400                 goto out;
3401
3402         rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3403                          *classes);
3404         if (rc) {
3405                 int i;
3406                 for (i = 0; i < *nclasses; i++)
3407                         kfree((*classes)[i]);
3408                 kfree(*classes);
3409         }
3410
3411 out:
3412         return rc;
3413 }
3414
3415 static int get_permissions_callback(void *k, void *d, void *args)
3416 {
3417         struct perm_datum *datum = d;
3418         char *name = k, **perms = args;
3419         int value = datum->value - 1;
3420
3421         perms[value] = kstrdup(name, GFP_ATOMIC);
3422         if (!perms[value])
3423                 return -ENOMEM;
3424
3425         return 0;
3426 }
3427
3428 int security_get_permissions(struct selinux_policy *policy,
3429                              char *class, char ***perms, int *nperms)
3430 {
3431         struct policydb *policydb;
3432         int rc, i;
3433         struct class_datum *match;
3434
3435         policydb = &policy->policydb;
3436
3437         rc = -EINVAL;
3438         match = symtab_search(&policydb->p_classes, class);
3439         if (!match) {
3440                 pr_err("SELinux: %s:  unrecognized class %s\n",
3441                         __func__, class);
3442                 goto out;
3443         }
3444
3445         rc = -ENOMEM;
3446         *nperms = match->permissions.nprim;
3447         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3448         if (!*perms)
3449                 goto out;
3450
3451         if (match->comdatum) {
3452                 rc = hashtab_map(&match->comdatum->permissions.table,
3453                                  get_permissions_callback, *perms);
3454                 if (rc)
3455                         goto err;
3456         }
3457
3458         rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3459                          *perms);
3460         if (rc)
3461                 goto err;
3462
3463 out:
3464         return rc;
3465
3466 err:
3467         for (i = 0; i < *nperms; i++)
3468                 kfree((*perms)[i]);
3469         kfree(*perms);
3470         return rc;
3471 }
3472
3473 int security_get_reject_unknown(struct selinux_state *state)
3474 {
3475         struct selinux_policy *policy;
3476         int value;
3477
3478         if (!selinux_initialized(state))
3479                 return 0;
3480
3481         rcu_read_lock();
3482         policy = rcu_dereference(state->policy);
3483         value = policy->policydb.reject_unknown;
3484         rcu_read_unlock();
3485         return value;
3486 }
3487
3488 int security_get_allow_unknown(struct selinux_state *state)
3489 {
3490         struct selinux_policy *policy;
3491         int value;
3492
3493         if (!selinux_initialized(state))
3494                 return 0;
3495
3496         rcu_read_lock();
3497         policy = rcu_dereference(state->policy);
3498         value = policy->policydb.allow_unknown;
3499         rcu_read_unlock();
3500         return value;
3501 }
3502
3503 /**
3504  * security_policycap_supported - Check for a specific policy capability
3505  * @req_cap: capability
3506  *
3507  * Description:
3508  * This function queries the currently loaded policy to see if it supports the
3509  * capability specified by @req_cap.  Returns true (1) if the capability is
3510  * supported, false (0) if it isn't supported.
3511  *
3512  */
3513 int security_policycap_supported(struct selinux_state *state,
3514                                  unsigned int req_cap)
3515 {
3516         struct selinux_policy *policy;
3517         int rc;
3518
3519         if (!selinux_initialized(state))
3520                 return 0;
3521
3522         rcu_read_lock();
3523         policy = rcu_dereference(state->policy);
3524         rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3525         rcu_read_unlock();
3526
3527         return rc;
3528 }
3529
3530 struct selinux_audit_rule {
3531         u32 au_seqno;
3532         struct context au_ctxt;
3533 };
3534
3535 void selinux_audit_rule_free(void *vrule)
3536 {
3537         struct selinux_audit_rule *rule = vrule;
3538
3539         if (rule) {
3540                 context_destroy(&rule->au_ctxt);
3541                 kfree(rule);
3542         }
3543 }
3544
3545 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3546 {
3547         struct selinux_state *state = &selinux_state;
3548         struct selinux_policy *policy;
3549         struct policydb *policydb;
3550         struct selinux_audit_rule *tmprule;
3551         struct role_datum *roledatum;
3552         struct type_datum *typedatum;
3553         struct user_datum *userdatum;
3554         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3555         int rc = 0;
3556
3557         *rule = NULL;
3558
3559         if (!selinux_initialized(state))
3560                 return -EOPNOTSUPP;
3561
3562         switch (field) {
3563         case AUDIT_SUBJ_USER:
3564         case AUDIT_SUBJ_ROLE:
3565         case AUDIT_SUBJ_TYPE:
3566         case AUDIT_OBJ_USER:
3567         case AUDIT_OBJ_ROLE:
3568         case AUDIT_OBJ_TYPE:
3569                 /* only 'equals' and 'not equals' fit user, role, and type */
3570                 if (op != Audit_equal && op != Audit_not_equal)
3571                         return -EINVAL;
3572                 break;
3573         case AUDIT_SUBJ_SEN:
3574         case AUDIT_SUBJ_CLR:
3575         case AUDIT_OBJ_LEV_LOW:
3576         case AUDIT_OBJ_LEV_HIGH:
3577                 /* we do not allow a range, indicated by the presence of '-' */
3578                 if (strchr(rulestr, '-'))
3579                         return -EINVAL;
3580                 break;
3581         default:
3582                 /* only the above fields are valid */
3583                 return -EINVAL;
3584         }
3585
3586         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3587         if (!tmprule)
3588                 return -ENOMEM;
3589
3590         context_init(&tmprule->au_ctxt);
3591
3592         rcu_read_lock();
3593         policy = rcu_dereference(state->policy);
3594         policydb = &policy->policydb;
3595
3596         tmprule->au_seqno = policy->latest_granting;
3597
3598         switch (field) {
3599         case AUDIT_SUBJ_USER:
3600         case AUDIT_OBJ_USER:
3601                 rc = -EINVAL;
3602                 userdatum = symtab_search(&policydb->p_users, rulestr);
3603                 if (!userdatum)
3604                         goto out;
3605                 tmprule->au_ctxt.user = userdatum->value;
3606                 break;
3607         case AUDIT_SUBJ_ROLE:
3608         case AUDIT_OBJ_ROLE:
3609                 rc = -EINVAL;
3610                 roledatum = symtab_search(&policydb->p_roles, rulestr);
3611                 if (!roledatum)
3612                         goto out;
3613                 tmprule->au_ctxt.role = roledatum->value;
3614                 break;
3615         case AUDIT_SUBJ_TYPE:
3616         case AUDIT_OBJ_TYPE:
3617                 rc = -EINVAL;
3618                 typedatum = symtab_search(&policydb->p_types, rulestr);
3619                 if (!typedatum)
3620                         goto out;
3621                 tmprule->au_ctxt.type = typedatum->value;
3622                 break;
3623         case AUDIT_SUBJ_SEN:
3624         case AUDIT_SUBJ_CLR:
3625         case AUDIT_OBJ_LEV_LOW:
3626         case AUDIT_OBJ_LEV_HIGH:
3627                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3628                                      GFP_ATOMIC);
3629                 if (rc)
3630                         goto out;
3631                 break;
3632         }
3633         rc = 0;
3634 out:
3635         rcu_read_unlock();
3636
3637         if (rc) {
3638                 selinux_audit_rule_free(tmprule);
3639                 tmprule = NULL;
3640         }
3641
3642         *rule = tmprule;
3643
3644         return rc;
3645 }
3646
3647 /* Check to see if the rule contains any selinux fields */
3648 int selinux_audit_rule_known(struct audit_krule *rule)
3649 {
3650         int i;
3651
3652         for (i = 0; i < rule->field_count; i++) {
3653                 struct audit_field *f = &rule->fields[i];
3654                 switch (f->type) {
3655                 case AUDIT_SUBJ_USER:
3656                 case AUDIT_SUBJ_ROLE:
3657                 case AUDIT_SUBJ_TYPE:
3658                 case AUDIT_SUBJ_SEN:
3659                 case AUDIT_SUBJ_CLR:
3660                 case AUDIT_OBJ_USER:
3661                 case AUDIT_OBJ_ROLE:
3662                 case AUDIT_OBJ_TYPE:
3663                 case AUDIT_OBJ_LEV_LOW:
3664                 case AUDIT_OBJ_LEV_HIGH:
3665                         return 1;
3666                 }
3667         }
3668
3669         return 0;
3670 }
3671
3672 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3673 {
3674         struct selinux_state *state = &selinux_state;
3675         struct selinux_policy *policy;
3676         struct context *ctxt;
3677         struct mls_level *level;
3678         struct selinux_audit_rule *rule = vrule;
3679         int match = 0;
3680
3681         if (unlikely(!rule)) {
3682                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3683                 return -ENOENT;
3684         }
3685
3686         if (!selinux_initialized(state))
3687                 return 0;
3688
3689         rcu_read_lock();
3690
3691         policy = rcu_dereference(state->policy);
3692
3693         if (rule->au_seqno < policy->latest_granting) {
3694                 match = -ESTALE;
3695                 goto out;
3696         }
3697
3698         ctxt = sidtab_search(policy->sidtab, sid);
3699         if (unlikely(!ctxt)) {
3700                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3701                           sid);
3702                 match = -ENOENT;
3703                 goto out;
3704         }
3705
3706         /* a field/op pair that is not caught here will simply fall through
3707            without a match */
3708         switch (field) {
3709         case AUDIT_SUBJ_USER:
3710         case AUDIT_OBJ_USER:
3711                 switch (op) {
3712                 case Audit_equal:
3713                         match = (ctxt->user == rule->au_ctxt.user);
3714                         break;
3715                 case Audit_not_equal:
3716                         match = (ctxt->user != rule->au_ctxt.user);
3717                         break;
3718                 }
3719                 break;
3720         case AUDIT_SUBJ_ROLE:
3721         case AUDIT_OBJ_ROLE:
3722                 switch (op) {
3723                 case Audit_equal:
3724                         match = (ctxt->role == rule->au_ctxt.role);
3725                         break;
3726                 case Audit_not_equal:
3727                         match = (ctxt->role != rule->au_ctxt.role);
3728                         break;
3729                 }
3730                 break;
3731         case AUDIT_SUBJ_TYPE:
3732         case AUDIT_OBJ_TYPE:
3733                 switch (op) {
3734                 case Audit_equal:
3735                         match = (ctxt->type == rule->au_ctxt.type);
3736                         break;
3737                 case Audit_not_equal:
3738                         match = (ctxt->type != rule->au_ctxt.type);
3739                         break;
3740                 }
3741                 break;
3742         case AUDIT_SUBJ_SEN:
3743         case AUDIT_SUBJ_CLR:
3744         case AUDIT_OBJ_LEV_LOW:
3745         case AUDIT_OBJ_LEV_HIGH:
3746                 level = ((field == AUDIT_SUBJ_SEN ||
3747                           field == AUDIT_OBJ_LEV_LOW) ?
3748                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3749                 switch (op) {
3750                 case Audit_equal:
3751                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3752                                              level);
3753                         break;
3754                 case Audit_not_equal:
3755                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3756                                               level);
3757                         break;
3758                 case Audit_lt:
3759                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3760                                                level) &&
3761                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3762                                                level));
3763                         break;
3764                 case Audit_le:
3765                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3766                                               level);
3767                         break;
3768                 case Audit_gt:
3769                         match = (mls_level_dom(level,
3770                                               &rule->au_ctxt.range.level[0]) &&
3771                                  !mls_level_eq(level,
3772                                                &rule->au_ctxt.range.level[0]));
3773                         break;
3774                 case Audit_ge:
3775                         match = mls_level_dom(level,
3776                                               &rule->au_ctxt.range.level[0]);
3777                         break;
3778                 }
3779         }
3780
3781 out:
3782         rcu_read_unlock();
3783         return match;
3784 }
3785
3786 static int (*aurule_callback)(void) = audit_update_lsm_rules;
3787
3788 static int aurule_avc_callback(u32 event)
3789 {
3790         int err = 0;
3791
3792         if (event == AVC_CALLBACK_RESET && aurule_callback)
3793                 err = aurule_callback();
3794         return err;
3795 }
3796
3797 static int __init aurule_init(void)
3798 {
3799         int err;
3800
3801         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3802         if (err)
3803                 panic("avc_add_callback() failed, error %d\n", err);
3804
3805         return err;
3806 }
3807 __initcall(aurule_init);
3808
3809 #ifdef CONFIG_NETLABEL
3810 /**
3811  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3812  * @secattr: the NetLabel packet security attributes
3813  * @sid: the SELinux SID
3814  *
3815  * Description:
3816  * Attempt to cache the context in @ctx, which was derived from the packet in
3817  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3818  * already been initialized.
3819  *
3820  */
3821 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3822                                       u32 sid)
3823 {
3824         u32 *sid_cache;
3825
3826         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3827         if (sid_cache == NULL)
3828                 return;
3829         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3830         if (secattr->cache == NULL) {
3831                 kfree(sid_cache);
3832                 return;
3833         }
3834
3835         *sid_cache = sid;
3836         secattr->cache->free = kfree;
3837         secattr->cache->data = sid_cache;
3838         secattr->flags |= NETLBL_SECATTR_CACHE;
3839 }
3840
3841 /**
3842  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3843  * @secattr: the NetLabel packet security attributes
3844  * @sid: the SELinux SID
3845  *
3846  * Description:
3847  * Convert the given NetLabel security attributes in @secattr into a
3848  * SELinux SID.  If the @secattr field does not contain a full SELinux
3849  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3850  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3851  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3852  * conversion for future lookups.  Returns zero on success, negative values on
3853  * failure.
3854  *
3855  */
3856 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3857                                    struct netlbl_lsm_secattr *secattr,
3858                                    u32 *sid)
3859 {
3860         struct selinux_policy *policy;
3861         struct policydb *policydb;
3862         struct sidtab *sidtab;
3863         int rc;
3864         struct context *ctx;
3865         struct context ctx_new;
3866
3867         if (!selinux_initialized(state)) {
3868                 *sid = SECSID_NULL;
3869                 return 0;
3870         }
3871
3872 retry:
3873         rc = 0;
3874         rcu_read_lock();
3875         policy = rcu_dereference(state->policy);
3876         policydb = &policy->policydb;
3877         sidtab = policy->sidtab;
3878
3879         if (secattr->flags & NETLBL_SECATTR_CACHE)
3880                 *sid = *(u32 *)secattr->cache->data;
3881         else if (secattr->flags & NETLBL_SECATTR_SECID)
3882                 *sid = secattr->attr.secid;
3883         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3884                 rc = -EIDRM;
3885                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3886                 if (ctx == NULL)
3887                         goto out;
3888
3889                 context_init(&ctx_new);
3890                 ctx_new.user = ctx->user;
3891                 ctx_new.role = ctx->role;
3892                 ctx_new.type = ctx->type;
3893                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3894                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3895                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3896                         if (rc)
3897                                 goto out;
3898                 }
3899                 rc = -EIDRM;
3900                 if (!mls_context_isvalid(policydb, &ctx_new)) {
3901                         ebitmap_destroy(&ctx_new.range.level[0].cat);
3902                         goto out;
3903                 }
3904
3905                 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3906                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3907                 if (rc == -ESTALE) {
3908                         rcu_read_unlock();
3909                         goto retry;
3910                 }
3911                 if (rc)
3912                         goto out;
3913
3914                 security_netlbl_cache_add(secattr, *sid);
3915         } else
3916                 *sid = SECSID_NULL;
3917
3918 out:
3919         rcu_read_unlock();
3920         return rc;
3921 }
3922
3923 /**
3924  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3925  * @sid: the SELinux SID
3926  * @secattr: the NetLabel packet security attributes
3927  *
3928  * Description:
3929  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3930  * Returns zero on success, negative values on failure.
3931  *
3932  */
3933 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3934                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3935 {
3936         struct selinux_policy *policy;
3937         struct policydb *policydb;
3938         int rc;
3939         struct context *ctx;
3940
3941         if (!selinux_initialized(state))
3942                 return 0;
3943
3944         rcu_read_lock();
3945         policy = rcu_dereference(state->policy);
3946         policydb = &policy->policydb;
3947
3948         rc = -ENOENT;
3949         ctx = sidtab_search(policy->sidtab, sid);
3950         if (ctx == NULL)
3951                 goto out;
3952
3953         rc = -ENOMEM;
3954         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3955                                   GFP_ATOMIC);
3956         if (secattr->domain == NULL)
3957                 goto out;
3958
3959         secattr->attr.secid = sid;
3960         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3961         mls_export_netlbl_lvl(policydb, ctx, secattr);
3962         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3963 out:
3964         rcu_read_unlock();
3965         return rc;
3966 }
3967 #endif /* CONFIG_NETLABEL */
3968
3969 /**
3970  * security_read_policy - read the policy.
3971  * @data: binary policy data
3972  * @len: length of data in bytes
3973  *
3974  */
3975 int security_read_policy(struct selinux_state *state,
3976                          void **data, size_t *len)
3977 {
3978         struct selinux_policy *policy;
3979         int rc;
3980         struct policy_file fp;
3981
3982         policy = rcu_dereference_protected(
3983                         state->policy, lockdep_is_held(&state->policy_mutex));
3984         if (!policy)
3985                 return -EINVAL;
3986
3987         *len = policy->policydb.len;
3988         *data = vmalloc_user(*len);
3989         if (!*data)
3990                 return -ENOMEM;
3991
3992         fp.data = *data;
3993         fp.len = *len;
3994
3995         rc = policydb_write(&policy->policydb, &fp);
3996         if (rc)
3997                 return rc;
3998
3999         *len = (unsigned long)fp.data - (unsigned long)*data;
4000         return 0;
4001
4002 }