security/selinux/ss/services.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Implementation of the security services.
   4  *
   5  * Authors : Stephen Smalley, <sds@tycho.nsa.gov>
   6  *           James Morris <jmorris@redhat.com>
   7  *
   8  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   9  *
  10  *      Support for enhanced MLS infrastructure.
  11  *      Support for context based audit filters.
  12  *
  13  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  14  *
  15  *      Added conditional policy language extensions
  16  *
  17  * Updated: Hewlett-Packard <paul@paul-moore.com>
  18  *
  19  *      Added support for NetLabel
  20  *      Added support for the policy capability bitmap
  21  *
  22  * Updated: Chad Sellers <csellers@tresys.com>
  23  *
  24  *  Added validation of kernel classes and permissions
  25  *
  26  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  27  *
  28  *  Added support for bounds domain and audit messaged on masked permissions
  29  *
  30  * Updated: Guido Trentalancia <guido@trentalancia.com>
  31  *
  32  *  Added support for runtime switching of the policy type
  33  *
  34  * Copyright (C) 2008, 2009 NEC Corporation
  35  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  36  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  37  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  38  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  39  */
  40 #include <linux/kernel.h>
  41 #include <linux/slab.h>
  42 #include <linux/string.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/rcupdate.h>
  45 #include <linux/errno.h>
  46 #include <linux/in.h>
  47 #include <linux/sched.h>
  48 #include <linux/audit.h>
  49 #include <linux/vmalloc.h>
  50 #include <linux/lsm_hooks.h>
  51 #include <net/netlabel.h>
  52
  53 #include "flask.h"
  54 #include "avc.h"
  55 #include "avc_ss.h"
  56 #include "security.h"
  57 #include "context.h"
  58 #include "policydb.h"
  59 #include "sidtab.h"
  60 #include "services.h"
  61 #include "conditional.h"
  62 #include "mls.h"
  63 #include "objsec.h"
  64 #include "netlabel.h"
  65 #include "xfrm.h"
  66 #include "ebitmap.h"
  67 #include "audit.h"
  68 #include "policycap_names.h"
  69 #include "ima.h"
  70
  71 struct convert_context_args {
  72         struct selinux_state *state;
  73         struct policydb *oldp;
  74         struct policydb *newp;
  75 };
  76
  77 struct selinux_policy_convert_data {
  78         struct convert_context_args args;
  79         struct sidtab_convert_params sidtab_params;
  80 };
  81
  82 /* Forward declaration. */
  83 static int context_struct_to_string(struct policydb *policydb,
  84                                     struct context *context,
  85                                     char **scontext,
  86                                     u32 *scontext_len);
  87
  88 static int sidtab_entry_to_string(struct policydb *policydb,
  89                                   struct sidtab *sidtab,
  90                                   struct sidtab_entry *entry,
  91                                   char **scontext,
  92                                   u32 *scontext_len);
  93
  94 static void context_struct_compute_av(struct policydb *policydb,
  95                                       struct context *scontext,
  96                                       struct context *tcontext,
  97                                       u16 tclass,
  98                                       struct av_decision *avd,
  99                                       struct extended_perms *xperms);
 100
 101 static int selinux_set_mapping(struct policydb *pol,
 102                                struct security_class_mapping *map,
 103                                struct selinux_map *out_map)
 104 {
 105         u16 i, j;
 106         unsigned k;
 107         bool print_unknown_handle = false;
 108
 109         /* Find number of classes in the input mapping */
 110         if (!map)
 111                 return -EINVAL;
 112         i = 0;
 113         while (map[i].name)
 114                 i++;
 115
 116         /* Allocate space for the class records, plus one for class zero */
 117         out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
 118         if (!out_map->mapping)
 119                 return -ENOMEM;
 120
 121         /* Store the raw class and permission values */
 122         j = 0;
 123         while (map[j].name) {
 124                 struct security_class_mapping *p_in = map + (j++);
 125                 struct selinux_mapping *p_out = out_map->mapping + j;
 126
 127                 /* An empty class string skips ahead */
 128                 if (!strcmp(p_in->name, "")) {
 129                         p_out->num_perms = 0;
 130                         continue;
 131                 }
 132
 133                 p_out->value = string_to_security_class(pol, p_in->name);
 134                 if (!p_out->value) {
 135                         pr_info("SELinux:  Class %s not defined in policy.\n",
 136                                p_in->name);
 137                         if (pol->reject_unknown)
 138                                 goto err;
 139                         p_out->num_perms = 0;
 140                         print_unknown_handle = true;
 141                         continue;
 142                 }
 143
 144                 k = 0;
 145                 while (p_in->perms[k]) {
 146                         /* An empty permission string skips ahead */
 147                         if (!*p_in->perms[k]) {
 148                                 k++;
 149                                 continue;
 150                         }
 151                         p_out->perms[k] = string_to_av_perm(pol, p_out->value,
 152                                                             p_in->perms[k]);
 153                         if (!p_out->perms[k]) {
 154                                 pr_info("SELinux:  Permission %s in class %s not defined in policy.\n",
 155                                        p_in->perms[k], p_in->name);
 156                                 if (pol->reject_unknown)
 157                                         goto err;
 158                                 print_unknown_handle = true;
 159                         }
 160
 161                         k++;
 162                 }
 163                 p_out->num_perms = k;
 164         }
 165
 166         if (print_unknown_handle)
 167                 pr_info("SELinux: the above unknown classes and permissions will be %s\n",
 168                        pol->allow_unknown ? "allowed" : "denied");
 169
 170         out_map->size = i;
 171         return 0;
 172 err:
 173         kfree(out_map->mapping);
 174         out_map->mapping = NULL;
 175         return -EINVAL;
 176 }
 177
 178 /*
 179  * Get real, policy values from mapped values
 180  */
 181
 182 static u16 unmap_class(struct selinux_map *map, u16 tclass)
 183 {
 184         if (tclass < map->size)
 185                 return map->mapping[tclass].value;
 186
 187         return tclass;
 188 }
 189
 190 /*
 191  * Get kernel value for class from its policy value
 192  */
 193 static u16 map_class(struct selinux_map *map, u16 pol_value)
 194 {
 195         u16 i;
 196
 197         for (i = 1; i < map->size; i++) {
 198                 if (map->mapping[i].value == pol_value)
 199                         return i;
 200         }
 201
 202         return SECCLASS_NULL;
 203 }
 204
 205 static void map_decision(struct selinux_map *map,
 206                          u16 tclass, struct av_decision *avd,
 207                          int allow_unknown)
 208 {
 209         if (tclass < map->size) {
 210                 struct selinux_mapping *mapping = &map->mapping[tclass];
 211                 unsigned int i, n = mapping->num_perms;
 212                 u32 result;
 213
 214                 for (i = 0, result = 0; i < n; i++) {
 215                         if (avd->allowed & mapping->perms[i])
 216                                 result |= 1<<i;
 217                         if (allow_unknown && !mapping->perms[i])
 218                                 result |= 1<<i;
 219                 }
 220                 avd->allowed = result;
 221
 222                 for (i = 0, result = 0; i < n; i++)
 223                         if (avd->auditallow & mapping->perms[i])
 224                                 result |= 1<<i;
 225                 avd->auditallow = result;
 226
 227                 for (i = 0, result = 0; i < n; i++) {
 228                         if (avd->auditdeny & mapping->perms[i])
 229                                 result |= 1<<i;
 230                         if (!allow_unknown && !mapping->perms[i])
 231                                 result |= 1<<i;
 232                 }
 233                 /*
 234                  * In case the kernel has a bug and requests a permission
 235                  * between num_perms and the maximum permission number, we
 236                  * should audit that denial
 237                  */
 238                 for (; i < (sizeof(u32)*8); i++)
 239                         result |= 1<<i;
 240                 avd->auditdeny = result;
 241         }
 242 }
 243
 244 int security_mls_enabled(struct selinux_state *state)
 245 {
 246         int mls_enabled;
 247         struct selinux_policy *policy;
 248
 249         if (!selinux_initialized(state))
 250                 return 0;
 251
 252         rcu_read_lock();
 253         policy = rcu_dereference(state->policy);
 254         mls_enabled = policy->policydb.mls_enabled;
 255         rcu_read_unlock();
 256         return mls_enabled;
 257 }
 258
 259 /*
 260  * Return the boolean value of a constraint expression
 261  * when it is applied to the specified source and target
 262  * security contexts.
 263  *
 264  * xcontext is a special beast...  It is used by the validatetrans rules
 265  * only.  For these rules, scontext is the context before the transition,
 266  * tcontext is the context after the transition, and xcontext is the context
 267  * of the process performing the transition.  All other callers of
 268  * constraint_expr_eval should pass in NULL for xcontext.
 269  */
 270 static int constraint_expr_eval(struct policydb *policydb,
 271                                 struct context *scontext,
 272                                 struct context *tcontext,
 273                                 struct context *xcontext,
 274                                 struct constraint_expr *cexpr)
 275 {
 276         u32 val1, val2;
 277         struct context *c;
 278         struct role_datum *r1, *r2;
 279         struct mls_level *l1, *l2;
 280         struct constraint_expr *e;
 281         int s[CEXPR_MAXDEPTH];
 282         int sp = -1;
 283
 284         for (e = cexpr; e; e = e->next) {
 285                 switch (e->expr_type) {
 286                 case CEXPR_NOT:
 287                         BUG_ON(sp < 0);
 288                         s[sp] = !s[sp];
 289                         break;
 290                 case CEXPR_AND:
 291                         BUG_ON(sp < 1);
 292                         sp--;
 293                         s[sp] &= s[sp + 1];
 294                         break;
 295                 case CEXPR_OR:
 296                         BUG_ON(sp < 1);
 297                         sp--;
 298                         s[sp] |= s[sp + 1];
 299                         break;
 300                 case CEXPR_ATTR:
 301                         if (sp == (CEXPR_MAXDEPTH - 1))
 302                                 return 0;
 303                         switch (e->attr) {
 304                         case CEXPR_USER:
 305                                 val1 = scontext->user;
 306                                 val2 = tcontext->user;
 307                                 break;
 308                         case CEXPR_TYPE:
 309                                 val1 = scontext->type;
 310                                 val2 = tcontext->type;
 311                                 break;
 312                         case CEXPR_ROLE:
 313                                 val1 = scontext->role;
 314                                 val2 = tcontext->role;
 315                                 r1 = policydb->role_val_to_struct[val1 - 1];
 316                                 r2 = policydb->role_val_to_struct[val2 - 1];
 317                                 switch (e->op) {
 318                                 case CEXPR_DOM:
 319                                         s[++sp] = ebitmap_get_bit(&r1->dominates,
 320                                                                   val2 - 1);
 321                                         continue;
 322                                 case CEXPR_DOMBY:
 323                                         s[++sp] = ebitmap_get_bit(&r2->dominates,
 324                                                                   val1 - 1);
 325                                         continue;
 326                                 case CEXPR_INCOMP:
 327                                         s[++sp] = (!ebitmap_get_bit(&r1->dominates,
 328                                                                     val2 - 1) &&
 329                                                    !ebitmap_get_bit(&r2->dominates,
 330                                                                     val1 - 1));
 331                                         continue;
 332                                 default:
 333                                         break;
 334                                 }
 335                                 break;
 336                         case CEXPR_L1L2:
 337                                 l1 = &(scontext->range.level[0]);
 338                                 l2 = &(tcontext->range.level[0]);
 339                                 goto mls_ops;
 340                         case CEXPR_L1H2:
 341                                 l1 = &(scontext->range.level[0]);
 342                                 l2 = &(tcontext->range.level[1]);
 343                                 goto mls_ops;
 344                         case CEXPR_H1L2:
 345                                 l1 = &(scontext->range.level[1]);
 346                                 l2 = &(tcontext->range.level[0]);
 347                                 goto mls_ops;
 348                         case CEXPR_H1H2:
 349                                 l1 = &(scontext->range.level[1]);
 350                                 l2 = &(tcontext->range.level[1]);
 351                                 goto mls_ops;
 352                         case CEXPR_L1H1:
 353                                 l1 = &(scontext->range.level[0]);
 354                                 l2 = &(scontext->range.level[1]);
 355                                 goto mls_ops;
 356                         case CEXPR_L2H2:
 357                                 l1 = &(tcontext->range.level[0]);
 358                                 l2 = &(tcontext->range.level[1]);
 359                                 goto mls_ops;
 360 mls_ops:
 361                         switch (e->op) {
 362                         case CEXPR_EQ:
 363                                 s[++sp] = mls_level_eq(l1, l2);
 364                                 continue;
 365                         case CEXPR_NEQ:
 366                                 s[++sp] = !mls_level_eq(l1, l2);
 367                                 continue;
 368                         case CEXPR_DOM:
 369                                 s[++sp] = mls_level_dom(l1, l2);
 370                                 continue;
 371                         case CEXPR_DOMBY:
 372                                 s[++sp] = mls_level_dom(l2, l1);
 373                                 continue;
 374                         case CEXPR_INCOMP:
 375                                 s[++sp] = mls_level_incomp(l2, l1);
 376                                 continue;
 377                         default:
 378                                 BUG();
 379                                 return 0;
 380                         }
 381                         break;
 382                         default:
 383                                 BUG();
 384                                 return 0;
 385                         }
 386
 387                         switch (e->op) {
 388                         case CEXPR_EQ:
 389                                 s[++sp] = (val1 == val2);
 390                                 break;
 391                         case CEXPR_NEQ:
 392                                 s[++sp] = (val1 != val2);
 393                                 break;
 394                         default:
 395                                 BUG();
 396                                 return 0;
 397                         }
 398                         break;
 399                 case CEXPR_NAMES:
 400                         if (sp == (CEXPR_MAXDEPTH-1))
 401                                 return 0;
 402                         c = scontext;
 403                         if (e->attr & CEXPR_TARGET)
 404                                 c = tcontext;
 405                         else if (e->attr & CEXPR_XTARGET) {
 406                                 c = xcontext;
 407                                 if (!c) {
 408                                         BUG();
 409                                         return 0;
 410                                 }
 411                         }
 412                         if (e->attr & CEXPR_USER)
 413                                 val1 = c->user;
 414                         else if (e->attr & CEXPR_ROLE)
 415                                 val1 = c->role;
 416                         else if (e->attr & CEXPR_TYPE)
 417                                 val1 = c->type;
 418                         else {
 419                                 BUG();
 420                                 return 0;
 421                         }
 422
 423                         switch (e->op) {
 424                         case CEXPR_EQ:
 425                                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 426                                 break;
 427                         case CEXPR_NEQ:
 428                                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 429                                 break;
 430                         default:
 431                                 BUG();
 432                                 return 0;
 433                         }
 434                         break;
 435                 default:
 436                         BUG();
 437                         return 0;
 438                 }
 439         }
 440
 441         BUG_ON(sp != 0);
 442         return s[0];
 443 }
 444
 445 /*
 446  * security_dump_masked_av - dumps masked permissions during
 447  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
 448  */
 449 static int dump_masked_av_helper(void *k, void *d, void *args)
 450 {
 451         struct perm_datum *pdatum = d;
 452         char **permission_names = args;
 453
 454         BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 455
 456         permission_names[pdatum->value - 1] = (char *)k;
 457
 458         return 0;
 459 }
 460
 461 static void security_dump_masked_av(struct policydb *policydb,
 462                                     struct context *scontext,
 463                                     struct context *tcontext,
 464                                     u16 tclass,
 465                                     u32 permissions,
 466                                     const char *reason)
 467 {
 468         struct common_datum *common_dat;
 469         struct class_datum *tclass_dat;
 470         struct audit_buffer *ab;
 471         char *tclass_name;
 472         char *scontext_name = NULL;
 473         char *tcontext_name = NULL;
 474         char *permission_names[32];
 475         int index;
 476         u32 length;
 477         bool need_comma = false;
 478
 479         if (!permissions)
 480                 return;
 481
 482         tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
 483         tclass_dat = policydb->class_val_to_struct[tclass - 1];
 484         common_dat = tclass_dat->comdatum;
 485
 486         /* init permission_names */
 487         if (common_dat &&
 488             hashtab_map(&common_dat->permissions.table,
 489                         dump_masked_av_helper, permission_names) < 0)
 490                 goto out;
 491
 492         if (hashtab_map(&tclass_dat->permissions.table,
 493                         dump_masked_av_helper, permission_names) < 0)
 494                 goto out;
 495
 496         /* get scontext/tcontext in text form */
 497         if (context_struct_to_string(policydb, scontext,
 498                                      &scontext_name, &length) < 0)
 499                 goto out;
 500
 501         if (context_struct_to_string(policydb, tcontext,
 502                                      &tcontext_name, &length) < 0)
 503                 goto out;
 504
 505         /* audit a message */
 506         ab = audit_log_start(audit_context(),
 507                              GFP_ATOMIC, AUDIT_SELINUX_ERR);
 508         if (!ab)
 509                 goto out;
 510
 511         audit_log_format(ab, "op=security_compute_av reason=%s "
 512                          "scontext=%s tcontext=%s tclass=%s perms=",
 513                          reason, scontext_name, tcontext_name, tclass_name);
 514
 515         for (index = 0; index < 32; index++) {
 516                 u32 mask = (1 << index);
 517
 518                 if ((mask & permissions) == 0)
 519                         continue;
 520
 521                 audit_log_format(ab, "%s%s",
 522                                  need_comma ? "," : "",
 523                                  permission_names[index]
 524                                  ? permission_names[index] : "????");
 525                 need_comma = true;
 526         }
 527         audit_log_end(ab);
 528 out:
 529         /* release scontext/tcontext */
 530         kfree(tcontext_name);
 531         kfree(scontext_name);
 532
 533         return;
 534 }
 535
 536 /*
 537  * security_boundary_permission - drops violated permissions
 538  * on boundary constraint.
 539  */
 540 static void type_attribute_bounds_av(struct policydb *policydb,
 541                                      struct context *scontext,
 542                                      struct context *tcontext,
 543                                      u16 tclass,
 544                                      struct av_decision *avd)
 545 {
 546         struct context lo_scontext;
 547         struct context lo_tcontext, *tcontextp = tcontext;
 548         struct av_decision lo_avd;
 549         struct type_datum *source;
 550         struct type_datum *target;
 551         u32 masked = 0;
 552
 553         source = policydb->type_val_to_struct[scontext->type - 1];
 554         BUG_ON(!source);
 555
 556         if (!source->bounds)
 557                 return;
 558
 559         target = policydb->type_val_to_struct[tcontext->type - 1];
 560         BUG_ON(!target);
 561
 562         memset(&lo_avd, 0, sizeof(lo_avd));
 563
 564         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 565         lo_scontext.type = source->bounds;
 566
 567         if (target->bounds) {
 568                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 569                 lo_tcontext.type = target->bounds;
 570                 tcontextp = &lo_tcontext;
 571         }
 572
 573         context_struct_compute_av(policydb, &lo_scontext,
 574                                   tcontextp,
 575                                   tclass,
 576                                   &lo_avd,
 577                                   NULL);
 578
 579         masked = ~lo_avd.allowed & avd->allowed;
 580
 581         if (likely(!masked))
 582                 return;         /* no masked permission */
 583
 584         /* mask violated permissions */
 585         avd->allowed &= ~masked;
 586
 587         /* audit masked permissions */
 588         security_dump_masked_av(policydb, scontext, tcontext,
 589                                 tclass, masked, "bounds");
 590 }
 591
 592 /*
 593  * flag which drivers have permissions
 594  * only looking for ioctl based extended permssions
 595  */
 596 void services_compute_xperms_drivers(
 597                 struct extended_perms *xperms,
 598                 struct avtab_node *node)
 599 {
 600         unsigned int i;
 601
 602         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 603                 /* if one or more driver has all permissions allowed */
 604                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 605                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 606         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 607                 /* if allowing permissions within a driver */
 608                 security_xperm_set(xperms->drivers.p,
 609                                         node->datum.u.xperms->driver);
 610         }
 611
 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  * @state: SELinux state
 863  * @oldsid : current security identifier
 864  * @newsid : destinated security identifier
 865  */
 866 int security_bounded_transition(struct selinux_state *state,
 867                                 u32 old_sid, u32 new_sid)
 868 {
 869         struct selinux_policy *policy;
 870         struct policydb *policydb;
 871         struct sidtab *sidtab;
 872         struct sidtab_entry *old_entry, *new_entry;
 873         struct type_datum *type;
 874         int index;
 875         int rc;
 876
 877         if (!selinux_initialized(state))
 878                 return 0;
 879
 880         rcu_read_lock();
 881         policy = rcu_dereference(state->policy);
 882         policydb = &policy->policydb;
 883         sidtab = policy->sidtab;
 884
 885         rc = -EINVAL;
 886         old_entry = sidtab_search_entry(sidtab, old_sid);
 887         if (!old_entry) {
 888                 pr_err("SELinux: %s: unrecognized SID %u\n",
 889                        __func__, old_sid);
 890                 goto out;
 891         }
 892
 893         rc = -EINVAL;
 894         new_entry = sidtab_search_entry(sidtab, new_sid);
 895         if (!new_entry) {
 896                 pr_err("SELinux: %s: unrecognized SID %u\n",
 897                        __func__, new_sid);
 898                 goto out;
 899         }
 900
 901         rc = 0;
 902         /* type/domain unchanged */
 903         if (old_entry->context.type == new_entry->context.type)
 904                 goto out;
 905
 906         index = new_entry->context.type;
 907         while (true) {
 908                 type = policydb->type_val_to_struct[index - 1];
 909                 BUG_ON(!type);
 910
 911                 /* not bounded anymore */
 912                 rc = -EPERM;
 913                 if (!type->bounds)
 914                         break;
 915
 916                 /* @newsid is bounded by @oldsid */
 917                 rc = 0;
 918                 if (type->bounds == old_entry->context.type)
 919                         break;
 920
 921                 index = type->bounds;
 922         }
 923
 924         if (rc) {
 925                 char *old_name = NULL;
 926                 char *new_name = NULL;
 927                 u32 length;
 928
 929                 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
 930                                             &old_name, &length) &&
 931                     !sidtab_entry_to_string(policydb, sidtab, new_entry,
 932                                             &new_name, &length)) {
 933                         audit_log(audit_context(),
 934                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 935                                   "op=security_bounded_transition "
 936                                   "seresult=denied "
 937                                   "oldcontext=%s newcontext=%s",
 938                                   old_name, new_name);
 939                 }
 940                 kfree(new_name);
 941                 kfree(old_name);
 942         }
 943 out:
 944         rcu_read_unlock();
 945
 946         return rc;
 947 }
 948
 949 static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
 950 {
 951         avd->allowed = 0;
 952         avd->auditallow = 0;
 953         avd->auditdeny = 0xffffffff;
 954         if (policy)
 955                 avd->seqno = policy->latest_granting;
 956         else
 957                 avd->seqno = 0;
 958         avd->flags = 0;
 959 }
 960
 961 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 962                                         struct avtab_node *node)
 963 {
 964         unsigned int i;
 965
 966         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 967                 if (xpermd->driver != node->datum.u.xperms->driver)
 968                         return;
 969         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 970                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 971                                         xpermd->driver))
 972                         return;
 973         } else {
 974                 BUG();
 975         }
 976
 977         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 978                 xpermd->used |= XPERMS_ALLOWED;
 979                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 980                         memset(xpermd->allowed->p, 0xff,
 981                                         sizeof(xpermd->allowed->p));
 982                 }
 983                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 984                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 985                                 xpermd->allowed->p[i] |=
 986                                         node->datum.u.xperms->perms.p[i];
 987                 }
 988         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 989                 xpermd->used |= XPERMS_AUDITALLOW;
 990                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 991                         memset(xpermd->auditallow->p, 0xff,
 992                                         sizeof(xpermd->auditallow->p));
 993                 }
 994                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 995                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 996                                 xpermd->auditallow->p[i] |=
 997                                         node->datum.u.xperms->perms.p[i];
 998                 }
 999         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
1000                 xpermd->used |= XPERMS_DONTAUDIT;
1001                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
1002                         memset(xpermd->dontaudit->p, 0xff,
1003                                         sizeof(xpermd->dontaudit->p));
1004                 }
1005                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1006                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1007                                 xpermd->dontaudit->p[i] |=
1008                                         node->datum.u.xperms->perms.p[i];
1009                 }
1010         } else {
1011                 BUG();
1012         }
1013 }
1014
1015 void security_compute_xperms_decision(struct selinux_state *state,
1016                                       u32 ssid,
1017                                       u32 tsid,
1018                                       u16 orig_tclass,
1019                                       u8 driver,
1020                                       struct extended_perms_decision *xpermd)
1021 {
1022         struct selinux_policy *policy;
1023         struct policydb *policydb;
1024         struct sidtab *sidtab;
1025         u16 tclass;
1026         struct context *scontext, *tcontext;
1027         struct avtab_key avkey;
1028         struct avtab_node *node;
1029         struct ebitmap *sattr, *tattr;
1030         struct ebitmap_node *snode, *tnode;
1031         unsigned int i, j;
1032
1033         xpermd->driver = driver;
1034         xpermd->used = 0;
1035         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1036         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1037         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1038
1039         rcu_read_lock();
1040         if (!selinux_initialized(state))
1041                 goto allow;
1042
1043         policy = rcu_dereference(state->policy);
1044         policydb = &policy->policydb;
1045         sidtab = policy->sidtab;
1046
1047         scontext = sidtab_search(sidtab, ssid);
1048         if (!scontext) {
1049                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1050                        __func__, ssid);
1051                 goto out;
1052         }
1053
1054         tcontext = sidtab_search(sidtab, tsid);
1055         if (!tcontext) {
1056                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1057                        __func__, tsid);
1058                 goto out;
1059         }
1060
1061         tclass = unmap_class(&policy->map, orig_tclass);
1062         if (unlikely(orig_tclass && !tclass)) {
1063                 if (policydb->allow_unknown)
1064                         goto allow;
1065                 goto out;
1066         }
1067
1068
1069         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1070                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1071                 goto out;
1072         }
1073
1074         avkey.target_class = tclass;
1075         avkey.specified = AVTAB_XPERMS;
1076         sattr = &policydb->type_attr_map_array[scontext->type - 1];
1077         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1078         ebitmap_for_each_positive_bit(sattr, snode, i) {
1079                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1080                         avkey.source_type = i + 1;
1081                         avkey.target_type = j + 1;
1082                         for (node = avtab_search_node(&policydb->te_avtab,
1083                                                       &avkey);
1084                              node;
1085                              node = avtab_search_node_next(node, avkey.specified))
1086                                 services_compute_xperms_decision(xpermd, node);
1087
1088                         cond_compute_xperms(&policydb->te_cond_avtab,
1089                                                 &avkey, xpermd);
1090                 }
1091         }
1092 out:
1093         rcu_read_unlock();
1094         return;
1095 allow:
1096         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1097         goto out;
1098 }
1099
1100 /**
1101  * security_compute_av - Compute access vector decisions.
1102  * @state: SELinux state
1103  * @ssid: source security identifier
1104  * @tsid: target security identifier
1105  * @tclass: target security class
1106  * @avd: access vector decisions
1107  * @xperms: extended permissions
1108  *
1109  * Compute a set of access vector decisions based on the
1110  * SID pair (@ssid, @tsid) for the permissions in @tclass.
1111  */
1112 void security_compute_av(struct selinux_state *state,
1113                          u32 ssid,
1114                          u32 tsid,
1115                          u16 orig_tclass,
1116                          struct av_decision *avd,
1117                          struct extended_perms *xperms)
1118 {
1119         struct selinux_policy *policy;
1120         struct policydb *policydb;
1121         struct sidtab *sidtab;
1122         u16 tclass;
1123         struct context *scontext = NULL, *tcontext = NULL;
1124
1125         rcu_read_lock();
1126         policy = rcu_dereference(state->policy);
1127         avd_init(policy, avd);
1128         xperms->len = 0;
1129         if (!selinux_initialized(state))
1130                 goto allow;
1131
1132         policydb = &policy->policydb;
1133         sidtab = policy->sidtab;
1134
1135         scontext = sidtab_search(sidtab, ssid);
1136         if (!scontext) {
1137                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1138                        __func__, ssid);
1139                 goto out;
1140         }
1141
1142         /* permissive domain? */
1143         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1144                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1145
1146         tcontext = sidtab_search(sidtab, tsid);
1147         if (!tcontext) {
1148                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1149                        __func__, tsid);
1150                 goto out;
1151         }
1152
1153         tclass = unmap_class(&policy->map, orig_tclass);
1154         if (unlikely(orig_tclass && !tclass)) {
1155                 if (policydb->allow_unknown)
1156                         goto allow;
1157                 goto out;
1158         }
1159         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1160                                   xperms);
1161         map_decision(&policy->map, orig_tclass, avd,
1162                      policydb->allow_unknown);
1163 out:
1164         rcu_read_unlock();
1165         return;
1166 allow:
1167         avd->allowed = 0xffffffff;
1168         goto out;
1169 }
1170
1171 void security_compute_av_user(struct selinux_state *state,
1172                               u32 ssid,
1173                               u32 tsid,
1174                               u16 tclass,
1175                               struct av_decision *avd)
1176 {
1177         struct selinux_policy *policy;
1178         struct policydb *policydb;
1179         struct sidtab *sidtab;
1180         struct context *scontext = NULL, *tcontext = NULL;
1181
1182         rcu_read_lock();
1183         policy = rcu_dereference(state->policy);
1184         avd_init(policy, avd);
1185         if (!selinux_initialized(state))
1186                 goto allow;
1187
1188         policydb = &policy->policydb;
1189         sidtab = policy->sidtab;
1190
1191         scontext = sidtab_search(sidtab, ssid);
1192         if (!scontext) {
1193                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1194                        __func__, ssid);
1195                 goto out;
1196         }
1197
1198         /* permissive domain? */
1199         if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
1200                 avd->flags |= AVD_FLAGS_PERMISSIVE;
1201
1202         tcontext = sidtab_search(sidtab, tsid);
1203         if (!tcontext) {
1204                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1205                        __func__, tsid);
1206                 goto out;
1207         }
1208
1209         if (unlikely(!tclass)) {
1210                 if (policydb->allow_unknown)
1211                         goto allow;
1212                 goto out;
1213         }
1214
1215         context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
1216                                   NULL);
1217  out:
1218         rcu_read_unlock();
1219         return;
1220 allow:
1221         avd->allowed = 0xffffffff;
1222         goto out;
1223 }
1224
1225 /*
1226  * Write the security context string representation of
1227  * the context structure `context' into a dynamically
1228  * allocated string of the correct size.  Set `*scontext'
1229  * to point to this string and set `*scontext_len' to
1230  * the length of the string.
1231  */
1232 static int context_struct_to_string(struct policydb *p,
1233                                     struct context *context,
1234                                     char **scontext, u32 *scontext_len)
1235 {
1236         char *scontextp;
1237
1238         if (scontext)
1239                 *scontext = NULL;
1240         *scontext_len = 0;
1241
1242         if (context->len) {
1243                 *scontext_len = context->len;
1244                 if (scontext) {
1245                         *scontext = kstrdup(context->str, GFP_ATOMIC);
1246                         if (!(*scontext))
1247                                 return -ENOMEM;
1248                 }
1249                 return 0;
1250         }
1251
1252         /* Compute the size of the context. */
1253         *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
1254         *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
1255         *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
1256         *scontext_len += mls_compute_context_len(p, context);
1257
1258         if (!scontext)
1259                 return 0;
1260
1261         /* Allocate space for the context; caller must free this space. */
1262         scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
1263         if (!scontextp)
1264                 return -ENOMEM;
1265         *scontext = scontextp;
1266
1267         /*
1268          * Copy the user name, role name and type name into the context.
1269          */
1270         scontextp += sprintf(scontextp, "%s:%s:%s",
1271                 sym_name(p, SYM_USERS, context->user - 1),
1272                 sym_name(p, SYM_ROLES, context->role - 1),
1273                 sym_name(p, SYM_TYPES, context->type - 1));
1274
1275         mls_sid_to_context(p, context, &scontextp);
1276
1277         *scontextp = 0;
1278
1279         return 0;
1280 }
1281
1282 static int sidtab_entry_to_string(struct policydb *p,
1283                                   struct sidtab *sidtab,
1284                                   struct sidtab_entry *entry,
1285                                   char **scontext, u32 *scontext_len)
1286 {
1287         int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
1288
1289         if (rc != -ENOENT)
1290                 return rc;
1291
1292         rc = context_struct_to_string(p, &entry->context, scontext,
1293                                       scontext_len);
1294         if (!rc && scontext)
1295                 sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
1296         return rc;
1297 }
1298
1299 #include "initial_sid_to_string.h"
1300
1301 int security_sidtab_hash_stats(struct selinux_state *state, char *page)
1302 {
1303         struct selinux_policy *policy;
1304         int rc;
1305
1306         if (!selinux_initialized(state)) {
1307                 pr_err("SELinux: %s:  called before initial load_policy\n",
1308                        __func__);
1309                 return -EINVAL;
1310         }
1311
1312         rcu_read_lock();
1313         policy = rcu_dereference(state->policy);
1314         rc = sidtab_hash_stats(policy->sidtab, page);
1315         rcu_read_unlock();
1316
1317         return rc;
1318 }
1319
1320 const char *security_get_initial_sid_context(u32 sid)
1321 {
1322         if (unlikely(sid > SECINITSID_NUM))
1323                 return NULL;
1324         return initial_sid_to_string[sid];
1325 }
1326
1327 static int security_sid_to_context_core(struct selinux_state *state,
1328                                         u32 sid, char **scontext,
1329                                         u32 *scontext_len, int force,
1330                                         int only_invalid)
1331 {
1332         struct selinux_policy *policy;
1333         struct policydb *policydb;
1334         struct sidtab *sidtab;
1335         struct sidtab_entry *entry;
1336         int rc = 0;
1337
1338         if (scontext)
1339                 *scontext = NULL;
1340         *scontext_len  = 0;
1341
1342         if (!selinux_initialized(state)) {
1343                 if (sid <= SECINITSID_NUM) {
1344                         char *scontextp;
1345                         const char *s = initial_sid_to_string[sid];
1346
1347                         if (!s)
1348                                 return -EINVAL;
1349                         *scontext_len = strlen(s) + 1;
1350                         if (!scontext)
1351                                 return 0;
1352                         scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
1353                         if (!scontextp)
1354                                 return -ENOMEM;
1355                         *scontext = scontextp;
1356                         return 0;
1357                 }
1358                 pr_err("SELinux: %s:  called before initial "
1359                        "load_policy on unknown SID %d\n", __func__, sid);
1360                 return -EINVAL;
1361         }
1362         rcu_read_lock();
1363         policy = rcu_dereference(state->policy);
1364         policydb = &policy->policydb;
1365         sidtab = policy->sidtab;
1366
1367         if (force)
1368                 entry = sidtab_search_entry_force(sidtab, sid);
1369         else
1370                 entry = sidtab_search_entry(sidtab, sid);
1371         if (!entry) {
1372                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1373                         __func__, sid);
1374                 rc = -EINVAL;
1375                 goto out_unlock;
1376         }
1377         if (only_invalid && !entry->context.len)
1378                 goto out_unlock;
1379
1380         rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
1381                                     scontext_len);
1382
1383 out_unlock:
1384         rcu_read_unlock();
1385         return rc;
1386
1387 }
1388
1389 /**
1390  * security_sid_to_context - Obtain a context for a given SID.
1391  * @state: SELinux state
1392  * @sid: security identifier, SID
1393  * @scontext: security context
1394  * @scontext_len: length in bytes
1395  *
1396  * Write the string representation of the context associated with @sid
1397  * into a dynamically allocated string of the correct size.  Set @scontext
1398  * to point to this string and set @scontext_len to the length of the string.
1399  */
1400 int security_sid_to_context(struct selinux_state *state,
1401                             u32 sid, char **scontext, u32 *scontext_len)
1402 {
1403         return security_sid_to_context_core(state, sid, scontext,
1404                                             scontext_len, 0, 0);
1405 }
1406
1407 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1408                                   char **scontext, u32 *scontext_len)
1409 {
1410         return security_sid_to_context_core(state, sid, scontext,
1411                                             scontext_len, 1, 0);
1412 }
1413
1414 /**
1415  * security_sid_to_context_inval - Obtain a context for a given SID if it
1416  *                                 is invalid.
1417  * @state: SELinux state
1418  * @sid: security identifier, SID
1419  * @scontext: security context
1420  * @scontext_len: length in bytes
1421  *
1422  * Write the string representation of the context associated with @sid
1423  * into a dynamically allocated string of the correct size, but only if the
1424  * context is invalid in the current policy.  Set @scontext to point to
1425  * this string (or NULL if the context is valid) and set @scontext_len to
1426  * the length of the string (or 0 if the context is valid).
1427  */
1428 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1429                                   char **scontext, u32 *scontext_len)
1430 {
1431         return security_sid_to_context_core(state, sid, scontext,
1432                                             scontext_len, 1, 1);
1433 }
1434
1435 /*
1436  * Caveat:  Mutates scontext.
1437  */
1438 static int string_to_context_struct(struct policydb *pol,
1439                                     struct sidtab *sidtabp,
1440                                     char *scontext,
1441                                     struct context *ctx,
1442                                     u32 def_sid)
1443 {
1444         struct role_datum *role;
1445         struct type_datum *typdatum;
1446         struct user_datum *usrdatum;
1447         char *scontextp, *p, oldc;
1448         int rc = 0;
1449
1450         context_init(ctx);
1451
1452         /* Parse the security context. */
1453
1454         rc = -EINVAL;
1455         scontextp = (char *) scontext;
1456
1457         /* Extract the user. */
1458         p = scontextp;
1459         while (*p && *p != ':')
1460                 p++;
1461
1462         if (*p == 0)
1463                 goto out;
1464
1465         *p++ = 0;
1466
1467         usrdatum = symtab_search(&pol->p_users, scontextp);
1468         if (!usrdatum)
1469                 goto out;
1470
1471         ctx->user = usrdatum->value;
1472
1473         /* Extract role. */
1474         scontextp = p;
1475         while (*p && *p != ':')
1476                 p++;
1477
1478         if (*p == 0)
1479                 goto out;
1480
1481         *p++ = 0;
1482
1483         role = symtab_search(&pol->p_roles, scontextp);
1484         if (!role)
1485                 goto out;
1486         ctx->role = role->value;
1487
1488         /* Extract type. */
1489         scontextp = p;
1490         while (*p && *p != ':')
1491                 p++;
1492         oldc = *p;
1493         *p++ = 0;
1494
1495         typdatum = symtab_search(&pol->p_types, scontextp);
1496         if (!typdatum || typdatum->attribute)
1497                 goto out;
1498
1499         ctx->type = typdatum->value;
1500
1501         rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1502         if (rc)
1503                 goto out;
1504
1505         /* Check the validity of the new context. */
1506         rc = -EINVAL;
1507         if (!policydb_context_isvalid(pol, ctx))
1508                 goto out;
1509         rc = 0;
1510 out:
1511         if (rc)
1512                 context_destroy(ctx);
1513         return rc;
1514 }
1515
1516 static int security_context_to_sid_core(struct selinux_state *state,
1517                                         const char *scontext, u32 scontext_len,
1518                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1519                                         int force)
1520 {
1521         struct selinux_policy *policy;
1522         struct policydb *policydb;
1523         struct sidtab *sidtab;
1524         char *scontext2, *str = NULL;
1525         struct context context;
1526         int rc = 0;
1527
1528         /* An empty security context is never valid. */
1529         if (!scontext_len)
1530                 return -EINVAL;
1531
1532         /* Copy the string to allow changes and ensure a NUL terminator */
1533         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1534         if (!scontext2)
1535                 return -ENOMEM;
1536
1537         if (!selinux_initialized(state)) {
1538                 int i;
1539
1540                 for (i = 1; i < SECINITSID_NUM; i++) {
1541                         const char *s = initial_sid_to_string[i];
1542
1543                         if (s && !strcmp(s, scontext2)) {
1544                                 *sid = i;
1545                                 goto out;
1546                         }
1547                 }
1548                 *sid = SECINITSID_KERNEL;
1549                 goto out;
1550         }
1551         *sid = SECSID_NULL;
1552
1553         if (force) {
1554                 /* Save another copy for storing in uninterpreted form */
1555                 rc = -ENOMEM;
1556                 str = kstrdup(scontext2, gfp_flags);
1557                 if (!str)
1558                         goto out;
1559         }
1560 retry:
1561         rcu_read_lock();
1562         policy = rcu_dereference(state->policy);
1563         policydb = &policy->policydb;
1564         sidtab = policy->sidtab;
1565         rc = string_to_context_struct(policydb, sidtab, scontext2,
1566                                       &context, def_sid);
1567         if (rc == -EINVAL && force) {
1568                 context.str = str;
1569                 context.len = strlen(str) + 1;
1570                 str = NULL;
1571         } else if (rc)
1572                 goto out_unlock;
1573         rc = sidtab_context_to_sid(sidtab, &context, sid);
1574         if (rc == -ESTALE) {
1575                 rcu_read_unlock();
1576                 if (context.str) {
1577                         str = context.str;
1578                         context.str = NULL;
1579                 }
1580                 context_destroy(&context);
1581                 goto retry;
1582         }
1583         context_destroy(&context);
1584 out_unlock:
1585         rcu_read_unlock();
1586 out:
1587         kfree(scontext2);
1588         kfree(str);
1589         return rc;
1590 }
1591
1592 /**
1593  * security_context_to_sid - Obtain a SID for a given security context.
1594  * @state: SELinux state
1595  * @scontext: security context
1596  * @scontext_len: length in bytes
1597  * @sid: security identifier, SID
1598  * @gfp: context for the allocation
1599  *
1600  * Obtains a SID associated with the security context that
1601  * has the string representation specified by @scontext.
1602  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1603  * memory is available, or 0 on success.
1604  */
1605 int security_context_to_sid(struct selinux_state *state,
1606                             const char *scontext, u32 scontext_len, u32 *sid,
1607                             gfp_t gfp)
1608 {
1609         return security_context_to_sid_core(state, scontext, scontext_len,
1610                                             sid, SECSID_NULL, gfp, 0);
1611 }
1612
1613 int security_context_str_to_sid(struct selinux_state *state,
1614                                 const char *scontext, u32 *sid, gfp_t gfp)
1615 {
1616         return security_context_to_sid(state, scontext, strlen(scontext),
1617                                        sid, gfp);
1618 }
1619
1620 /**
1621  * security_context_to_sid_default - Obtain a SID for a given security context,
1622  * falling back to specified default if needed.
1623  *
1624  * @state: SELinux state
1625  * @scontext: security context
1626  * @scontext_len: length in bytes
1627  * @sid: security identifier, SID
1628  * @def_sid: default SID to assign on error
1629  *
1630  * Obtains a SID associated with the security context that
1631  * has the string representation specified by @scontext.
1632  * The default SID is passed to the MLS layer to be used to allow
1633  * kernel labeling of the MLS field if the MLS field is not present
1634  * (for upgrading to MLS without full relabel).
1635  * Implicitly forces adding of the context even if it cannot be mapped yet.
1636  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1637  * memory is available, or 0 on success.
1638  */
1639 int security_context_to_sid_default(struct selinux_state *state,
1640                                     const char *scontext, u32 scontext_len,
1641                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1642 {
1643         return security_context_to_sid_core(state, scontext, scontext_len,
1644                                             sid, def_sid, gfp_flags, 1);
1645 }
1646
1647 int security_context_to_sid_force(struct selinux_state *state,
1648                                   const char *scontext, u32 scontext_len,
1649                                   u32 *sid)
1650 {
1651         return security_context_to_sid_core(state, scontext, scontext_len,
1652                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1653 }
1654
1655 static int compute_sid_handle_invalid_context(
1656         struct selinux_state *state,
1657         struct selinux_policy *policy,
1658         struct sidtab_entry *sentry,
1659         struct sidtab_entry *tentry,
1660         u16 tclass,
1661         struct context *newcontext)
1662 {
1663         struct policydb *policydb = &policy->policydb;
1664         struct sidtab *sidtab = policy->sidtab;
1665         char *s = NULL, *t = NULL, *n = NULL;
1666         u32 slen, tlen, nlen;
1667         struct audit_buffer *ab;
1668
1669         if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1670                 goto out;
1671         if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1672                 goto out;
1673         if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1674                 goto out;
1675         ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1676         audit_log_format(ab,
1677                          "op=security_compute_sid invalid_context=");
1678         /* no need to record the NUL with untrusted strings */
1679         audit_log_n_untrustedstring(ab, n, nlen - 1);
1680         audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1681                          s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1682         audit_log_end(ab);
1683 out:
1684         kfree(s);
1685         kfree(t);
1686         kfree(n);
1687         if (!enforcing_enabled(state))
1688                 return 0;
1689         return -EACCES;
1690 }
1691
1692 static void filename_compute_type(struct policydb *policydb,
1693                                   struct context *newcontext,
1694                                   u32 stype, u32 ttype, u16 tclass,
1695                                   const char *objname)
1696 {
1697         struct filename_trans_key ft;
1698         struct filename_trans_datum *datum;
1699
1700         /*
1701          * Most filename trans rules are going to live in specific directories
1702          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1703          * if the ttype does not contain any rules.
1704          */
1705         if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1706                 return;
1707
1708         ft.ttype = ttype;
1709         ft.tclass = tclass;
1710         ft.name = objname;
1711
1712         datum = policydb_filenametr_search(policydb, &ft);
1713         while (datum) {
1714                 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1715                         newcontext->type = datum->otype;
1716                         return;
1717                 }
1718                 datum = datum->next;
1719         }
1720 }
1721
1722 static int security_compute_sid(struct selinux_state *state,
1723                                 u32 ssid,
1724                                 u32 tsid,
1725                                 u16 orig_tclass,
1726                                 u32 specified,
1727                                 const char *objname,
1728                                 u32 *out_sid,
1729                                 bool kern)
1730 {
1731         struct selinux_policy *policy;
1732         struct policydb *policydb;
1733         struct sidtab *sidtab;
1734         struct class_datum *cladatum;
1735         struct context *scontext, *tcontext, newcontext;
1736         struct sidtab_entry *sentry, *tentry;
1737         struct avtab_key avkey;
1738         struct avtab_datum *avdatum;
1739         struct avtab_node *node;
1740         u16 tclass;
1741         int rc = 0;
1742         bool sock;
1743
1744         if (!selinux_initialized(state)) {
1745                 switch (orig_tclass) {
1746                 case SECCLASS_PROCESS: /* kernel value */
1747                         *out_sid = ssid;
1748                         break;
1749                 default:
1750                         *out_sid = tsid;
1751                         break;
1752                 }
1753                 goto out;
1754         }
1755
1756 retry:
1757         cladatum = NULL;
1758         context_init(&newcontext);
1759
1760         rcu_read_lock();
1761
1762         policy = rcu_dereference(state->policy);
1763
1764         if (kern) {
1765                 tclass = unmap_class(&policy->map, orig_tclass);
1766                 sock = security_is_socket_class(orig_tclass);
1767         } else {
1768                 tclass = orig_tclass;
1769                 sock = security_is_socket_class(map_class(&policy->map,
1770                                                           tclass));
1771         }
1772
1773         policydb = &policy->policydb;
1774         sidtab = policy->sidtab;
1775
1776         sentry = sidtab_search_entry(sidtab, ssid);
1777         if (!sentry) {
1778                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1779                        __func__, ssid);
1780                 rc = -EINVAL;
1781                 goto out_unlock;
1782         }
1783         tentry = sidtab_search_entry(sidtab, tsid);
1784         if (!tentry) {
1785                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1786                        __func__, tsid);
1787                 rc = -EINVAL;
1788                 goto out_unlock;
1789         }
1790
1791         scontext = &sentry->context;
1792         tcontext = &tentry->context;
1793
1794         if (tclass && tclass <= policydb->p_classes.nprim)
1795                 cladatum = policydb->class_val_to_struct[tclass - 1];
1796
1797         /* Set the user identity. */
1798         switch (specified) {
1799         case AVTAB_TRANSITION:
1800         case AVTAB_CHANGE:
1801                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1802                         newcontext.user = tcontext->user;
1803                 } else {
1804                         /* notice this gets both DEFAULT_SOURCE and unset */
1805                         /* Use the process user identity. */
1806                         newcontext.user = scontext->user;
1807                 }
1808                 break;
1809         case AVTAB_MEMBER:
1810                 /* Use the related object owner. */
1811                 newcontext.user = tcontext->user;
1812                 break;
1813         }
1814
1815         /* Set the role to default values. */
1816         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1817                 newcontext.role = scontext->role;
1818         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1819                 newcontext.role = tcontext->role;
1820         } else {
1821                 if ((tclass == policydb->process_class) || sock)
1822                         newcontext.role = scontext->role;
1823                 else
1824                         newcontext.role = OBJECT_R_VAL;
1825         }
1826
1827         /* Set the type to default values. */
1828         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1829                 newcontext.type = scontext->type;
1830         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1831                 newcontext.type = tcontext->type;
1832         } else {
1833                 if ((tclass == policydb->process_class) || sock) {
1834                         /* Use the type of process. */
1835                         newcontext.type = scontext->type;
1836                 } else {
1837                         /* Use the type of the related object. */
1838                         newcontext.type = tcontext->type;
1839                 }
1840         }
1841
1842         /* Look for a type transition/member/change rule. */
1843         avkey.source_type = scontext->type;
1844         avkey.target_type = tcontext->type;
1845         avkey.target_class = tclass;
1846         avkey.specified = specified;
1847         avdatum = avtab_search(&policydb->te_avtab, &avkey);
1848
1849         /* If no permanent rule, also check for enabled conditional rules */
1850         if (!avdatum) {
1851                 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1852                 for (; node; node = avtab_search_node_next(node, specified)) {
1853                         if (node->key.specified & AVTAB_ENABLED) {
1854                                 avdatum = &node->datum;
1855                                 break;
1856                         }
1857                 }
1858         }
1859
1860         if (avdatum) {
1861                 /* Use the type from the type transition/member/change rule. */
1862                 newcontext.type = avdatum->u.data;
1863         }
1864
1865         /* if we have a objname this is a file trans check so check those rules */
1866         if (objname)
1867                 filename_compute_type(policydb, &newcontext, scontext->type,
1868                                       tcontext->type, tclass, objname);
1869
1870         /* Check for class-specific changes. */
1871         if (specified & AVTAB_TRANSITION) {
1872                 /* Look for a role transition rule. */
1873                 struct role_trans_datum *rtd;
1874                 struct role_trans_key rtk = {
1875                         .role = scontext->role,
1876                         .type = tcontext->type,
1877                         .tclass = tclass,
1878                 };
1879
1880                 rtd = policydb_roletr_search(policydb, &rtk);
1881                 if (rtd)
1882                         newcontext.role = rtd->new_role;
1883         }
1884
1885         /* Set the MLS attributes.
1886            This is done last because it may allocate memory. */
1887         rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1888                              &newcontext, sock);
1889         if (rc)
1890                 goto out_unlock;
1891
1892         /* Check the validity of the context. */
1893         if (!policydb_context_isvalid(policydb, &newcontext)) {
1894                 rc = compute_sid_handle_invalid_context(state, policy, sentry,
1895                                                         tentry, tclass,
1896                                                         &newcontext);
1897                 if (rc)
1898                         goto out_unlock;
1899         }
1900         /* Obtain the sid for the context. */
1901         rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1902         if (rc == -ESTALE) {
1903                 rcu_read_unlock();
1904                 context_destroy(&newcontext);
1905                 goto retry;
1906         }
1907 out_unlock:
1908         rcu_read_unlock();
1909         context_destroy(&newcontext);
1910 out:
1911         return rc;
1912 }
1913
1914 /**
1915  * security_transition_sid - Compute the SID for a new subject/object.
1916  * @state: SELinux state
1917  * @ssid: source security identifier
1918  * @tsid: target security identifier
1919  * @tclass: target security class
1920  * @out_sid: security identifier for new subject/object
1921  *
1922  * Compute a SID to use for labeling a new subject or object in the
1923  * class @tclass based on a SID pair (@ssid, @tsid).
1924  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1925  * if insufficient memory is available, or %0 if the new SID was
1926  * computed successfully.
1927  */
1928 int security_transition_sid(struct selinux_state *state,
1929                             u32 ssid, u32 tsid, u16 tclass,
1930                             const struct qstr *qstr, u32 *out_sid)
1931 {
1932         return security_compute_sid(state, ssid, tsid, tclass,
1933                                     AVTAB_TRANSITION,
1934                                     qstr ? qstr->name : NULL, out_sid, true);
1935 }
1936
1937 int security_transition_sid_user(struct selinux_state *state,
1938                                  u32 ssid, u32 tsid, u16 tclass,
1939                                  const char *objname, u32 *out_sid)
1940 {
1941         return security_compute_sid(state, ssid, tsid, tclass,
1942                                     AVTAB_TRANSITION,
1943                                     objname, out_sid, false);
1944 }
1945
1946 /**
1947  * security_member_sid - Compute the SID for member selection.
1948  * @ssid: source security identifier
1949  * @tsid: target security identifier
1950  * @tclass: target security class
1951  * @out_sid: security identifier for selected member
1952  *
1953  * Compute a SID to use when selecting a member of a polyinstantiated
1954  * object of class @tclass based on a SID pair (@ssid, @tsid).
1955  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1956  * if insufficient memory is available, or %0 if the SID was
1957  * computed successfully.
1958  */
1959 int security_member_sid(struct selinux_state *state,
1960                         u32 ssid,
1961                         u32 tsid,
1962                         u16 tclass,
1963                         u32 *out_sid)
1964 {
1965         return security_compute_sid(state, ssid, tsid, tclass,
1966                                     AVTAB_MEMBER, NULL,
1967                                     out_sid, false);
1968 }
1969
1970 /**
1971  * security_change_sid - Compute the SID for object relabeling.
1972  * @state: SELinux state
1973  * @ssid: source security identifier
1974  * @tsid: target security identifier
1975  * @tclass: target security class
1976  * @out_sid: security identifier for selected member
1977  *
1978  * Compute a SID to use for relabeling an object of class @tclass
1979  * based on a SID pair (@ssid, @tsid).
1980  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1981  * if insufficient memory is available, or %0 if the SID was
1982  * computed successfully.
1983  */
1984 int security_change_sid(struct selinux_state *state,
1985                         u32 ssid,
1986                         u32 tsid,
1987                         u16 tclass,
1988                         u32 *out_sid)
1989 {
1990         return security_compute_sid(state,
1991                                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1992                                     out_sid, false);
1993 }
1994
1995 static inline int convert_context_handle_invalid_context(
1996         struct selinux_state *state,
1997         struct policydb *policydb,
1998         struct context *context)
1999 {
2000         char *s;
2001         u32 len;
2002
2003         if (enforcing_enabled(state))
2004                 return -EINVAL;
2005
2006         if (!context_struct_to_string(policydb, context, &s, &len)) {
2007                 pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
2008                         s);
2009                 kfree(s);
2010         }
2011         return 0;
2012 }
2013
2014 /*
2015  * Convert the values in the security context
2016  * structure `oldc' from the values specified
2017  * in the policy `p->oldp' to the values specified
2018  * in the policy `p->newp', storing the new context
2019  * in `newc'.  Verify that the context is valid
2020  * under the new policy.
2021  */
2022 static int convert_context(struct context *oldc, struct context *newc, void *p)
2023 {
2024         struct convert_context_args *args;
2025         struct ocontext *oc;
2026         struct role_datum *role;
2027         struct type_datum *typdatum;
2028         struct user_datum *usrdatum;
2029         char *s;
2030         u32 len;
2031         int rc;
2032
2033         args = p;
2034
2035         if (oldc->str) {
2036                 s = kstrdup(oldc->str, GFP_KERNEL);
2037                 if (!s)
2038                         return -ENOMEM;
2039
2040                 rc = string_to_context_struct(args->newp, NULL, s,
2041                                               newc, SECSID_NULL);
2042                 if (rc == -EINVAL) {
2043                         /*
2044                          * Retain string representation for later mapping.
2045                          *
2046                          * IMPORTANT: We need to copy the contents of oldc->str
2047                          * back into s again because string_to_context_struct()
2048                          * may have garbled it.
2049                          */
2050                         memcpy(s, oldc->str, oldc->len);
2051                         context_init(newc);
2052                         newc->str = s;
2053                         newc->len = oldc->len;
2054                         return 0;
2055                 }
2056                 kfree(s);
2057                 if (rc) {
2058                         /* Other error condition, e.g. ENOMEM. */
2059                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
2060                                oldc->str, -rc);
2061                         return rc;
2062                 }
2063                 pr_info("SELinux:  Context %s became valid (mapped).\n",
2064                         oldc->str);
2065                 return 0;
2066         }
2067
2068         context_init(newc);
2069
2070         /* Convert the user. */
2071         usrdatum = symtab_search(&args->newp->p_users,
2072                                  sym_name(args->oldp,
2073                                           SYM_USERS, oldc->user - 1));
2074         if (!usrdatum)
2075                 goto bad;
2076         newc->user = usrdatum->value;
2077
2078         /* Convert the role. */
2079         role = symtab_search(&args->newp->p_roles,
2080                              sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2081         if (!role)
2082                 goto bad;
2083         newc->role = role->value;
2084
2085         /* Convert the type. */
2086         typdatum = symtab_search(&args->newp->p_types,
2087                                  sym_name(args->oldp,
2088                                           SYM_TYPES, oldc->type - 1));
2089         if (!typdatum)
2090                 goto bad;
2091         newc->type = typdatum->value;
2092
2093         /* Convert the MLS fields if dealing with MLS policies */
2094         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2095                 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2096                 if (rc)
2097                         goto bad;
2098         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2099                 /*
2100                  * Switching between non-MLS and MLS policy:
2101                  * ensure that the MLS fields of the context for all
2102                  * existing entries in the sidtab are filled in with a
2103                  * suitable default value, likely taken from one of the
2104                  * initial SIDs.
2105                  */
2106                 oc = args->newp->ocontexts[OCON_ISID];
2107                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2108                         oc = oc->next;
2109                 if (!oc) {
2110                         pr_err("SELinux:  unable to look up"
2111                                 " the initial SIDs list\n");
2112                         goto bad;
2113                 }
2114                 rc = mls_range_set(newc, &oc->context[0].range);
2115                 if (rc)
2116                         goto bad;
2117         }
2118
2119         /* Check the validity of the new context. */
2120         if (!policydb_context_isvalid(args->newp, newc)) {
2121                 rc = convert_context_handle_invalid_context(args->state,
2122                                                         args->oldp,
2123                                                         oldc);
2124                 if (rc)
2125                         goto bad;
2126         }
2127
2128         return 0;
2129 bad:
2130         /* Map old representation to string and save it. */
2131         rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2132         if (rc)
2133                 return rc;
2134         context_destroy(newc);
2135         newc->str = s;
2136         newc->len = len;
2137         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2138                 newc->str);
2139         return 0;
2140 }
2141
2142 static void security_load_policycaps(struct selinux_state *state,
2143                                 struct selinux_policy *policy)
2144 {
2145         struct policydb *p;
2146         unsigned int i;
2147         struct ebitmap_node *node;
2148
2149         p = &policy->policydb;
2150
2151         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2152                 WRITE_ONCE(state->policycap[i],
2153                         ebitmap_get_bit(&p->policycaps, i));
2154
2155         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2156                 pr_info("SELinux:  policy capability %s=%d\n",
2157                         selinux_policycap_names[i],
2158                         ebitmap_get_bit(&p->policycaps, i));
2159
2160         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2161                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2162                         pr_info("SELinux:  unknown policy capability %u\n",
2163                                 i);
2164         }
2165 }
2166
2167 static int security_preserve_bools(struct selinux_policy *oldpolicy,
2168                                 struct selinux_policy *newpolicy);
2169
2170 static void selinux_policy_free(struct selinux_policy *policy)
2171 {
2172         if (!policy)
2173                 return;
2174
2175         sidtab_destroy(policy->sidtab);
2176         kfree(policy->map.mapping);
2177         policydb_destroy(&policy->policydb);
2178         kfree(policy->sidtab);
2179         kfree(policy);
2180 }
2181
2182 static void selinux_policy_cond_free(struct selinux_policy *policy)
2183 {
2184         cond_policydb_destroy_dup(&policy->policydb);
2185         kfree(policy);
2186 }
2187
2188 void selinux_policy_cancel(struct selinux_state *state,
2189                            struct selinux_load_state *load_state)
2190 {
2191         struct selinux_policy *oldpolicy;
2192
2193         oldpolicy = rcu_dereference_protected(state->policy,
2194                                         lockdep_is_held(&state->policy_mutex));
2195
2196         sidtab_cancel_convert(oldpolicy->sidtab);
2197         selinux_policy_free(load_state->policy);
2198         kfree(load_state->convert_data);
2199 }
2200
2201 static void selinux_notify_policy_change(struct selinux_state *state,
2202                                         u32 seqno)
2203 {
2204         /* Flush external caches and notify userspace of policy load */
2205         avc_ss_reset(state->avc, seqno);
2206         selnl_notify_policyload(seqno);
2207         selinux_status_update_policyload(state, seqno);
2208         selinux_netlbl_cache_invalidate();
2209         selinux_xfrm_notify_policyload();
2210         selinux_ima_measure_state_locked(state);
2211 }
2212
2213 void selinux_policy_commit(struct selinux_state *state,
2214                            struct selinux_load_state *load_state)
2215 {
2216         struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2217         unsigned long flags;
2218         u32 seqno;
2219
2220         oldpolicy = rcu_dereference_protected(state->policy,
2221                                         lockdep_is_held(&state->policy_mutex));
2222
2223         /* If switching between different policy types, log MLS status */
2224         if (oldpolicy) {
2225                 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2226                         pr_info("SELinux: Disabling MLS support...\n");
2227                 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2228                         pr_info("SELinux: Enabling MLS support...\n");
2229         }
2230
2231         /* Set latest granting seqno for new policy. */
2232         if (oldpolicy)
2233                 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2234         else
2235                 newpolicy->latest_granting = 1;
2236         seqno = newpolicy->latest_granting;
2237
2238         /* Install the new policy. */
2239         if (oldpolicy) {
2240                 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2241                 rcu_assign_pointer(state->policy, newpolicy);
2242                 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2243         } else {
2244                 rcu_assign_pointer(state->policy, newpolicy);
2245         }
2246
2247         /* Load the policycaps from the new policy */
2248         security_load_policycaps(state, newpolicy);
2249
2250         if (!selinux_initialized(state)) {
2251                 /*
2252                  * After first policy load, the security server is
2253                  * marked as initialized and ready to handle requests and
2254                  * any objects created prior to policy load are then labeled.
2255                  */
2256                 selinux_mark_initialized(state);
2257                 selinux_complete_init();
2258         }
2259
2260         /* Free the old policy */
2261         synchronize_rcu();
2262         selinux_policy_free(oldpolicy);
2263         kfree(load_state->convert_data);
2264
2265         /* Notify others of the policy change */
2266         selinux_notify_policy_change(state, seqno);
2267 }
2268
2269 /**
2270  * security_load_policy - Load a security policy configuration.
2271  * @state: SELinux state
2272  * @data: binary policy data
2273  * @len: length of data in bytes
2274  *
2275  * Load a new set of security policy configuration data,
2276  * validate it and convert the SID table as necessary.
2277  * This function will flush the access vector cache after
2278  * loading the new policy.
2279  */
2280 int security_load_policy(struct selinux_state *state, void *data, size_t len,
2281                          struct selinux_load_state *load_state)
2282 {
2283         struct selinux_policy *newpolicy, *oldpolicy;
2284         struct selinux_policy_convert_data *convert_data;
2285         int rc = 0;
2286         struct policy_file file = { data, len }, *fp = &file;
2287
2288         newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2289         if (!newpolicy)
2290                 return -ENOMEM;
2291
2292         newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2293         if (!newpolicy->sidtab) {
2294                 rc = -ENOMEM;
2295                 goto err_policy;
2296         }
2297
2298         rc = policydb_read(&newpolicy->policydb, fp);
2299         if (rc)
2300                 goto err_sidtab;
2301
2302         newpolicy->policydb.len = len;
2303         rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2304                                 &newpolicy->map);
2305         if (rc)
2306                 goto err_policydb;
2307
2308         rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2309         if (rc) {
2310                 pr_err("SELinux:  unable to load the initial SIDs\n");
2311                 goto err_mapping;
2312         }
2313
2314         if (!selinux_initialized(state)) {
2315                 /* First policy load, so no need to preserve state from old policy */
2316                 load_state->policy = newpolicy;
2317                 load_state->convert_data = NULL;
2318                 return 0;
2319         }
2320
2321         oldpolicy = rcu_dereference_protected(state->policy,
2322                                         lockdep_is_held(&state->policy_mutex));
2323
2324         /* Preserve active boolean values from the old policy */
2325         rc = security_preserve_bools(oldpolicy, newpolicy);
2326         if (rc) {
2327                 pr_err("SELinux:  unable to preserve booleans\n");
2328                 goto err_free_isids;
2329         }
2330
2331         convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2332         if (!convert_data) {
2333                 rc = -ENOMEM;
2334                 goto err_free_isids;
2335         }
2336
2337         /*
2338          * Convert the internal representations of contexts
2339          * in the new SID table.
2340          */
2341         convert_data->args.state = state;
2342         convert_data->args.oldp = &oldpolicy->policydb;
2343         convert_data->args.newp = &newpolicy->policydb;
2344
2345         convert_data->sidtab_params.func = convert_context;
2346         convert_data->sidtab_params.args = &convert_data->args;
2347         convert_data->sidtab_params.target = newpolicy->sidtab;
2348
2349         rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2350         if (rc) {
2351                 pr_err("SELinux:  unable to convert the internal"
2352                         " representation of contexts in the new SID"
2353                         " table\n");
2354                 goto err_free_convert_data;
2355         }
2356
2357         load_state->policy = newpolicy;
2358         load_state->convert_data = convert_data;
2359         return 0;
2360
2361 err_free_convert_data:
2362         kfree(convert_data);
2363 err_free_isids:
2364         sidtab_destroy(newpolicy->sidtab);
2365 err_mapping:
2366         kfree(newpolicy->map.mapping);
2367 err_policydb:
2368         policydb_destroy(&newpolicy->policydb);
2369 err_sidtab:
2370         kfree(newpolicy->sidtab);
2371 err_policy:
2372         kfree(newpolicy);
2373
2374         return rc;
2375 }
2376
2377 /**
2378  * security_port_sid - Obtain the SID for a port.
2379  * @state: SELinux state
2380  * @protocol: protocol number
2381  * @port: port number
2382  * @out_sid: security identifier
2383  */
2384 int security_port_sid(struct selinux_state *state,
2385                       u8 protocol, u16 port, u32 *out_sid)
2386 {
2387         struct selinux_policy *policy;
2388         struct policydb *policydb;
2389         struct sidtab *sidtab;
2390         struct ocontext *c;
2391         int rc;
2392
2393         if (!selinux_initialized(state)) {
2394                 *out_sid = SECINITSID_PORT;
2395                 return 0;
2396         }
2397
2398 retry:
2399         rc = 0;
2400         rcu_read_lock();
2401         policy = rcu_dereference(state->policy);
2402         policydb = &policy->policydb;
2403         sidtab = policy->sidtab;
2404
2405         c = policydb->ocontexts[OCON_PORT];
2406         while (c) {
2407                 if (c->u.port.protocol == protocol &&
2408                     c->u.port.low_port <= port &&
2409                     c->u.port.high_port >= port)
2410                         break;
2411                 c = c->next;
2412         }
2413
2414         if (c) {
2415                 if (!c->sid[0]) {
2416                         rc = sidtab_context_to_sid(sidtab, &c->context[0],
2417                                                    &c->sid[0]);
2418                         if (rc == -ESTALE) {
2419                                 rcu_read_unlock();
2420                                 goto retry;
2421                         }
2422                         if (rc)
2423                                 goto out;
2424                 }
2425                 *out_sid = c->sid[0];
2426         } else {
2427                 *out_sid = SECINITSID_PORT;
2428         }
2429
2430 out:
2431         rcu_read_unlock();
2432         return rc;
2433 }
2434
2435 /**
2436  * security_ib_pkey_sid - Obtain the SID for a pkey.
2437  * @state: SELinux state
2438  * @subnet_prefix: Subnet Prefix
2439  * @pkey_num: pkey number
2440  * @out_sid: security identifier
2441  */
2442 int security_ib_pkey_sid(struct selinux_state *state,
2443                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2444 {
2445         struct selinux_policy *policy;
2446         struct policydb *policydb;
2447         struct sidtab *sidtab;
2448         struct ocontext *c;
2449         int rc;
2450
2451         if (!selinux_initialized(state)) {
2452                 *out_sid = SECINITSID_UNLABELED;
2453                 return 0;
2454         }
2455
2456 retry:
2457         rc = 0;
2458         rcu_read_lock();
2459         policy = rcu_dereference(state->policy);
2460         policydb = &policy->policydb;
2461         sidtab = policy->sidtab;
2462
2463         c = policydb->ocontexts[OCON_IBPKEY];
2464         while (c) {
2465                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2466                     c->u.ibpkey.high_pkey >= pkey_num &&
2467                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2468                         break;
2469
2470                 c = c->next;
2471         }
2472
2473         if (c) {
2474                 if (!c->sid[0]) {
2475                         rc = sidtab_context_to_sid(sidtab,
2476                                                    &c->context[0],
2477                                                    &c->sid[0]);
2478                         if (rc == -ESTALE) {
2479                                 rcu_read_unlock();
2480                                 goto retry;
2481                         }
2482                         if (rc)
2483                                 goto out;
2484                 }
2485                 *out_sid = c->sid[0];
2486         } else
2487                 *out_sid = SECINITSID_UNLABELED;
2488
2489 out:
2490         rcu_read_unlock();
2491         return rc;
2492 }
2493
2494 /**
2495  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2496  * @state: SELinux state
2497  * @dev_name: device name
2498  * @port: port number
2499  * @out_sid: security identifier
2500  */
2501 int security_ib_endport_sid(struct selinux_state *state,
2502                             const char *dev_name, u8 port_num, u32 *out_sid)
2503 {
2504         struct selinux_policy *policy;
2505         struct policydb *policydb;
2506         struct sidtab *sidtab;
2507         struct ocontext *c;
2508         int rc;
2509
2510         if (!selinux_initialized(state)) {
2511                 *out_sid = SECINITSID_UNLABELED;
2512                 return 0;
2513         }
2514
2515 retry:
2516         rc = 0;
2517         rcu_read_lock();
2518         policy = rcu_dereference(state->policy);
2519         policydb = &policy->policydb;
2520         sidtab = policy->sidtab;
2521
2522         c = policydb->ocontexts[OCON_IBENDPORT];
2523         while (c) {
2524                 if (c->u.ibendport.port == port_num &&
2525                     !strncmp(c->u.ibendport.dev_name,
2526                              dev_name,
2527                              IB_DEVICE_NAME_MAX))
2528                         break;
2529
2530                 c = c->next;
2531         }
2532
2533         if (c) {
2534                 if (!c->sid[0]) {
2535                         rc = sidtab_context_to_sid(sidtab, &c->context[0],
2536                                                    &c->sid[0]);
2537                         if (rc == -ESTALE) {
2538                                 rcu_read_unlock();
2539                                 goto retry;
2540                         }
2541                         if (rc)
2542                                 goto out;
2543                 }
2544                 *out_sid = c->sid[0];
2545         } else
2546                 *out_sid = SECINITSID_UNLABELED;
2547
2548 out:
2549         rcu_read_unlock();
2550         return rc;
2551 }
2552
2553 /**
2554  * security_netif_sid - Obtain the SID for a network interface.
2555  * @state: SELinux state
2556  * @name: interface name
2557  * @if_sid: interface SID
2558  */
2559 int security_netif_sid(struct selinux_state *state,
2560                        char *name, u32 *if_sid)
2561 {
2562         struct selinux_policy *policy;
2563         struct policydb *policydb;
2564         struct sidtab *sidtab;
2565         int rc;
2566         struct ocontext *c;
2567
2568         if (!selinux_initialized(state)) {
2569                 *if_sid = SECINITSID_NETIF;
2570                 return 0;
2571         }
2572
2573 retry:
2574         rc = 0;
2575         rcu_read_lock();
2576         policy = rcu_dereference(state->policy);
2577         policydb = &policy->policydb;
2578         sidtab = policy->sidtab;
2579
2580         c = policydb->ocontexts[OCON_NETIF];
2581         while (c) {
2582                 if (strcmp(name, c->u.name) == 0)
2583                         break;
2584                 c = c->next;
2585         }
2586
2587         if (c) {
2588                 if (!c->sid[0] || !c->sid[1]) {
2589                         rc = sidtab_context_to_sid(sidtab, &c->context[0],
2590                                                    &c->sid[0]);
2591                         if (rc == -ESTALE) {
2592                                 rcu_read_unlock();
2593                                 goto retry;
2594                         }
2595                         if (rc)
2596                                 goto out;
2597                         rc = sidtab_context_to_sid(sidtab, &c->context[1],
2598                                                    &c->sid[1]);
2599                         if (rc == -ESTALE) {
2600                                 rcu_read_unlock();
2601                                 goto retry;
2602                         }
2603                         if (rc)
2604                                 goto out;
2605                 }
2606                 *if_sid = c->sid[0];
2607         } else
2608                 *if_sid = SECINITSID_NETIF;
2609
2610 out:
2611         rcu_read_unlock();
2612         return rc;
2613 }
2614
2615 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2616 {
2617         int i, fail = 0;
2618
2619         for (i = 0; i < 4; i++)
2620                 if (addr[i] != (input[i] & mask[i])) {
2621                         fail = 1;
2622                         break;
2623                 }
2624
2625         return !fail;
2626 }
2627
2628 /**
2629  * security_node_sid - Obtain the SID for a node (host).
2630  * @state: SELinux state
2631  * @domain: communication domain aka address family
2632  * @addrp: address
2633  * @addrlen: address length in bytes
2634  * @out_sid: security identifier
2635  */
2636 int security_node_sid(struct selinux_state *state,
2637                       u16 domain,
2638                       void *addrp,
2639                       u32 addrlen,
2640                       u32 *out_sid)
2641 {
2642         struct selinux_policy *policy;
2643         struct policydb *policydb;
2644         struct sidtab *sidtab;
2645         int rc;
2646         struct ocontext *c;
2647
2648         if (!selinux_initialized(state)) {
2649                 *out_sid = SECINITSID_NODE;
2650                 return 0;
2651         }
2652
2653 retry:
2654         rcu_read_lock();
2655         policy = rcu_dereference(state->policy);
2656         policydb = &policy->policydb;
2657         sidtab = policy->sidtab;
2658
2659         switch (domain) {
2660         case AF_INET: {
2661                 u32 addr;
2662
2663                 rc = -EINVAL;
2664                 if (addrlen != sizeof(u32))
2665                         goto out;
2666
2667                 addr = *((u32 *)addrp);
2668
2669                 c = policydb->ocontexts[OCON_NODE];
2670                 while (c) {
2671                         if (c->u.node.addr == (addr & c->u.node.mask))
2672                                 break;
2673                         c = c->next;
2674                 }
2675                 break;
2676         }
2677
2678         case AF_INET6:
2679                 rc = -EINVAL;
2680                 if (addrlen != sizeof(u64) * 2)
2681                         goto out;
2682                 c = policydb->ocontexts[OCON_NODE6];
2683                 while (c) {
2684                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2685                                                 c->u.node6.mask))
2686                                 break;
2687                         c = c->next;
2688                 }
2689                 break;
2690
2691         default:
2692                 rc = 0;
2693                 *out_sid = SECINITSID_NODE;
2694                 goto out;
2695         }
2696
2697         if (c) {
2698                 if (!c->sid[0]) {
2699                         rc = sidtab_context_to_sid(sidtab,
2700                                                    &c->context[0],
2701                                                    &c->sid[0]);
2702                         if (rc == -ESTALE) {
2703                                 rcu_read_unlock();
2704                                 goto retry;
2705                         }
2706                         if (rc)
2707                                 goto out;
2708                 }
2709                 *out_sid = c->sid[0];
2710         } else {
2711                 *out_sid = SECINITSID_NODE;
2712         }
2713
2714         rc = 0;
2715 out:
2716         rcu_read_unlock();
2717         return rc;
2718 }
2719
2720 #define SIDS_NEL 25
2721
2722 /**
2723  * security_get_user_sids - Obtain reachable SIDs for a user.
2724  * @state: SELinux state
2725  * @fromsid: starting SID
2726  * @username: username
2727  * @sids: array of reachable SIDs for user
2728  * @nel: number of elements in @sids
2729  *
2730  * Generate the set of SIDs for legal security contexts
2731  * for a given user that can be reached by @fromsid.
2732  * Set *@sids to point to a dynamically allocated
2733  * array containing the set of SIDs.  Set *@nel to the
2734  * number of elements in the array.
2735  */
2736
2737 int security_get_user_sids(struct selinux_state *state,
2738                            u32 fromsid,
2739                            char *username,
2740                            u32 **sids,
2741                            u32 *nel)
2742 {
2743         struct selinux_policy *policy;
2744         struct policydb *policydb;
2745         struct sidtab *sidtab;
2746         struct context *fromcon, usercon;
2747         u32 *mysids = NULL, *mysids2, sid;
2748         u32 i, j, mynel, maxnel = SIDS_NEL;
2749         struct user_datum *user;
2750         struct role_datum *role;
2751         struct ebitmap_node *rnode, *tnode;
2752         int rc;
2753
2754         *sids = NULL;
2755         *nel = 0;
2756
2757         if (!selinux_initialized(state))
2758                 return 0;
2759
2760         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2761         if (!mysids)
2762                 return -ENOMEM;
2763
2764 retry:
2765         mynel = 0;
2766         rcu_read_lock();
2767         policy = rcu_dereference(state->policy);
2768         policydb = &policy->policydb;
2769         sidtab = policy->sidtab;
2770
2771         context_init(&usercon);
2772
2773         rc = -EINVAL;
2774         fromcon = sidtab_search(sidtab, fromsid);
2775         if (!fromcon)
2776                 goto out_unlock;
2777
2778         rc = -EINVAL;
2779         user = symtab_search(&policydb->p_users, username);
2780         if (!user)
2781                 goto out_unlock;
2782
2783         usercon.user = user->value;
2784
2785         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2786                 role = policydb->role_val_to_struct[i];
2787                 usercon.role = i + 1;
2788                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2789                         usercon.type = j + 1;
2790
2791                         if (mls_setup_user_range(policydb, fromcon, user,
2792                                                  &usercon))
2793                                 continue;
2794
2795                         rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2796                         if (rc == -ESTALE) {
2797                                 rcu_read_unlock();
2798                                 goto retry;
2799                         }
2800                         if (rc)
2801                                 goto out_unlock;
2802                         if (mynel < maxnel) {
2803                                 mysids[mynel++] = sid;
2804                         } else {
2805                                 rc = -ENOMEM;
2806                                 maxnel += SIDS_NEL;
2807                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2808                                 if (!mysids2)
2809                                         goto out_unlock;
2810                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2811                                 kfree(mysids);
2812                                 mysids = mysids2;
2813                                 mysids[mynel++] = sid;
2814                         }
2815                 }
2816         }
2817         rc = 0;
2818 out_unlock:
2819         rcu_read_unlock();
2820         if (rc || !mynel) {
2821                 kfree(mysids);
2822                 return rc;
2823         }
2824
2825         rc = -ENOMEM;
2826         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2827         if (!mysids2) {
2828                 kfree(mysids);
2829                 return rc;
2830         }
2831         for (i = 0, j = 0; i < mynel; i++) {
2832                 struct av_decision dummy_avd;
2833                 rc = avc_has_perm_noaudit(state,
2834                                           fromsid, mysids[i],
2835                                           SECCLASS_PROCESS, /* kernel value */
2836                                           PROCESS__TRANSITION, AVC_STRICT,
2837                                           &dummy_avd);
2838                 if (!rc)
2839                         mysids2[j++] = mysids[i];
2840                 cond_resched();
2841         }
2842         kfree(mysids);
2843         *sids = mysids2;
2844         *nel = j;
2845         return 0;
2846 }
2847
2848 /**
2849  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2850  * @fstype: filesystem type
2851  * @path: path from root of mount
2852  * @sclass: file security class
2853  * @sid: SID for path
2854  *
2855  * Obtain a SID to use for a file in a filesystem that
2856  * cannot support xattr or use a fixed labeling behavior like
2857  * transition SIDs or task SIDs.
2858  *
2859  * WARNING: This function may return -ESTALE, indicating that the caller
2860  * must retry the operation after re-acquiring the policy pointer!
2861  */
2862 static inline int __security_genfs_sid(struct selinux_policy *policy,
2863                                        const char *fstype,
2864                                        char *path,
2865                                        u16 orig_sclass,
2866                                        u32 *sid)
2867 {
2868         struct policydb *policydb = &policy->policydb;
2869         struct sidtab *sidtab = policy->sidtab;
2870         int len;
2871         u16 sclass;
2872         struct genfs *genfs;
2873         struct ocontext *c;
2874         int rc, cmp = 0;
2875
2876         while (path[0] == '/' && path[1] == '/')
2877                 path++;
2878
2879         sclass = unmap_class(&policy->map, orig_sclass);
2880         *sid = SECINITSID_UNLABELED;
2881
2882         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2883                 cmp = strcmp(fstype, genfs->fstype);
2884                 if (cmp <= 0)
2885                         break;
2886         }
2887
2888         rc = -ENOENT;
2889         if (!genfs || cmp)
2890                 goto out;
2891
2892         for (c = genfs->head; c; c = c->next) {
2893                 len = strlen(c->u.name);
2894                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2895                     (strncmp(c->u.name, path, len) == 0))
2896                         break;
2897         }
2898
2899         rc = -ENOENT;
2900         if (!c)
2901                 goto out;
2902
2903         if (!c->sid[0]) {
2904                 rc = sidtab_context_to_sid(sidtab, &c->context[0], &c->sid[0]);
2905                 if (rc)
2906                         goto out;
2907         }
2908
2909         *sid = c->sid[0];
2910         rc = 0;
2911 out:
2912         return rc;
2913 }
2914
2915 /**
2916  * security_genfs_sid - Obtain a SID for a file in a filesystem
2917  * @state: SELinux state
2918  * @fstype: filesystem type
2919  * @path: path from root of mount
2920  * @sclass: file security class
2921  * @sid: SID for path
2922  *
2923  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2924  * it afterward.
2925  */
2926 int security_genfs_sid(struct selinux_state *state,
2927                        const char *fstype,
2928                        char *path,
2929                        u16 orig_sclass,
2930                        u32 *sid)
2931 {
2932         struct selinux_policy *policy;
2933         int retval;
2934
2935         if (!selinux_initialized(state)) {
2936                 *sid = SECINITSID_UNLABELED;
2937                 return 0;
2938         }
2939
2940         do {
2941                 rcu_read_lock();
2942                 policy = rcu_dereference(state->policy);
2943                 retval = __security_genfs_sid(policy, fstype, path,
2944                                               orig_sclass, sid);
2945                 rcu_read_unlock();
2946         } while (retval == -ESTALE);
2947         return retval;
2948 }
2949
2950 int selinux_policy_genfs_sid(struct selinux_policy *policy,
2951                         const char *fstype,
2952                         char *path,
2953                         u16 orig_sclass,
2954                         u32 *sid)
2955 {
2956         /* no lock required, policy is not yet accessible by other threads */
2957         return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2958 }
2959
2960 /**
2961  * security_fs_use - Determine how to handle labeling for a filesystem.
2962  * @state: SELinux state
2963  * @sb: superblock in question
2964  */
2965 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2966 {
2967         struct selinux_policy *policy;
2968         struct policydb *policydb;
2969         struct sidtab *sidtab;
2970         int rc;
2971         struct ocontext *c;
2972         struct superblock_security_struct *sbsec = selinux_superblock(sb);
2973         const char *fstype = sb->s_type->name;
2974
2975         if (!selinux_initialized(state)) {
2976                 sbsec->behavior = SECURITY_FS_USE_NONE;
2977                 sbsec->sid = SECINITSID_UNLABELED;
2978                 return 0;
2979         }
2980
2981 retry:
2982         rc = 0;
2983         rcu_read_lock();
2984         policy = rcu_dereference(state->policy);
2985         policydb = &policy->policydb;
2986         sidtab = policy->sidtab;
2987
2988         c = policydb->ocontexts[OCON_FSUSE];
2989         while (c) {
2990                 if (strcmp(fstype, c->u.name) == 0)
2991                         break;
2992                 c = c->next;
2993         }
2994
2995         if (c) {
2996                 sbsec->behavior = c->v.behavior;
2997                 if (!c->sid[0]) {
2998                         rc = sidtab_context_to_sid(sidtab, &c->context[0],
2999                                                    &c->sid[0]);
3000                         if (rc == -ESTALE) {
3001                                 rcu_read_unlock();
3002                                 goto retry;
3003                         }
3004                         if (rc)
3005                                 goto out;
3006                 }
3007                 sbsec->sid = c->sid[0];
3008         } else {
3009                 rc = __security_genfs_sid(policy, fstype, "/",
3010                                         SECCLASS_DIR, &sbsec->sid);
3011                 if (rc == -ESTALE) {
3012                         rcu_read_unlock();
3013                         goto retry;
3014                 }
3015                 if (rc) {
3016                         sbsec->behavior = SECURITY_FS_USE_NONE;
3017                         rc = 0;
3018                 } else {
3019                         sbsec->behavior = SECURITY_FS_USE_GENFS;
3020                 }
3021         }
3022
3023 out:
3024         rcu_read_unlock();
3025         return rc;
3026 }
3027
3028 int security_get_bools(struct selinux_policy *policy,
3029                        u32 *len, char ***names, int **values)
3030 {
3031         struct policydb *policydb;
3032         u32 i;
3033         int rc;
3034
3035         policydb = &policy->policydb;
3036
3037         *names = NULL;
3038         *values = NULL;
3039
3040         rc = 0;
3041         *len = policydb->p_bools.nprim;
3042         if (!*len)
3043                 goto out;
3044
3045         rc = -ENOMEM;
3046         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3047         if (!*names)
3048                 goto err;
3049
3050         rc = -ENOMEM;
3051         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3052         if (!*values)
3053                 goto err;
3054
3055         for (i = 0; i < *len; i++) {
3056                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3057
3058                 rc = -ENOMEM;
3059                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3060                                       GFP_ATOMIC);
3061                 if (!(*names)[i])
3062                         goto err;
3063         }
3064         rc = 0;
3065 out:
3066         return rc;
3067 err:
3068         if (*names) {
3069                 for (i = 0; i < *len; i++)
3070                         kfree((*names)[i]);
3071                 kfree(*names);
3072         }
3073         kfree(*values);
3074         *len = 0;
3075         *names = NULL;
3076         *values = NULL;
3077         goto out;
3078 }
3079
3080
3081 int security_set_bools(struct selinux_state *state, u32 len, int *values)
3082 {
3083         struct selinux_policy *newpolicy, *oldpolicy;
3084         int rc;
3085         u32 i, seqno = 0;
3086
3087         if (!selinux_initialized(state))
3088                 return -EINVAL;
3089
3090         oldpolicy = rcu_dereference_protected(state->policy,
3091                                         lockdep_is_held(&state->policy_mutex));
3092
3093         /* Consistency check on number of booleans, should never fail */
3094         if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3095                 return -EINVAL;
3096
3097         newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3098         if (!newpolicy)
3099                 return -ENOMEM;
3100
3101         /*
3102          * Deep copy only the parts of the policydb that might be
3103          * modified as a result of changing booleans.
3104          */
3105         rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3106         if (rc) {
3107                 kfree(newpolicy);
3108                 return -ENOMEM;
3109         }
3110
3111         /* Update the boolean states in the copy */
3112         for (i = 0; i < len; i++) {
3113                 int new_state = !!values[i];
3114                 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3115
3116                 if (new_state != old_state) {
3117                         audit_log(audit_context(), GFP_ATOMIC,
3118                                 AUDIT_MAC_CONFIG_CHANGE,
3119                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3120                                 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3121                                 new_state,
3122                                 old_state,
3123                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3124                                 audit_get_sessionid(current));
3125                         newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3126                 }
3127         }
3128
3129         /* Re-evaluate the conditional rules in the copy */
3130         evaluate_cond_nodes(&newpolicy->policydb);
3131
3132         /* Set latest granting seqno for new policy */
3133         newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3134         seqno = newpolicy->latest_granting;
3135
3136         /* Install the new policy */
3137         rcu_assign_pointer(state->policy, newpolicy);
3138
3139         /*
3140          * Free the conditional portions of the old policydb
3141          * that were copied for the new policy, and the oldpolicy
3142          * structure itself but not what it references.
3143          */
3144         synchronize_rcu();
3145         selinux_policy_cond_free(oldpolicy);
3146
3147         /* Notify others of the policy change */
3148         selinux_notify_policy_change(state, seqno);
3149         return 0;
3150 }
3151
3152 int security_get_bool_value(struct selinux_state *state,
3153                             u32 index)
3154 {
3155         struct selinux_policy *policy;
3156         struct policydb *policydb;
3157         int rc;
3158         u32 len;
3159
3160         if (!selinux_initialized(state))
3161                 return 0;
3162
3163         rcu_read_lock();
3164         policy = rcu_dereference(state->policy);
3165         policydb = &policy->policydb;
3166
3167         rc = -EFAULT;
3168         len = policydb->p_bools.nprim;
3169         if (index >= len)
3170                 goto out;
3171
3172         rc = policydb->bool_val_to_struct[index]->state;
3173 out:
3174         rcu_read_unlock();
3175         return rc;
3176 }
3177
3178 static int security_preserve_bools(struct selinux_policy *oldpolicy,
3179                                 struct selinux_policy *newpolicy)
3180 {
3181         int rc, *bvalues = NULL;
3182         char **bnames = NULL;
3183         struct cond_bool_datum *booldatum;
3184         u32 i, nbools = 0;
3185
3186         rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3187         if (rc)
3188                 goto out;
3189         for (i = 0; i < nbools; i++) {
3190                 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3191                                         bnames[i]);
3192                 if (booldatum)
3193                         booldatum->state = bvalues[i];
3194         }
3195         evaluate_cond_nodes(&newpolicy->policydb);
3196
3197 out:
3198         if (bnames) {
3199                 for (i = 0; i < nbools; i++)
3200                         kfree(bnames[i]);
3201         }
3202         kfree(bnames);
3203         kfree(bvalues);
3204         return rc;
3205 }
3206
3207 /*
3208  * security_sid_mls_copy() - computes a new sid based on the given
3209  * sid and the mls portion of mls_sid.
3210  */
3211 int security_sid_mls_copy(struct selinux_state *state,
3212                           u32 sid, u32 mls_sid, u32 *new_sid)
3213 {
3214         struct selinux_policy *policy;
3215         struct policydb *policydb;
3216         struct sidtab *sidtab;
3217         struct context *context1;
3218         struct context *context2;
3219         struct context newcon;
3220         char *s;
3221         u32 len;
3222         int rc;
3223
3224         if (!selinux_initialized(state)) {
3225                 *new_sid = sid;
3226                 return 0;
3227         }
3228
3229 retry:
3230         rc = 0;
3231         context_init(&newcon);
3232
3233         rcu_read_lock();
3234         policy = rcu_dereference(state->policy);
3235         policydb = &policy->policydb;
3236         sidtab = policy->sidtab;
3237
3238         if (!policydb->mls_enabled) {
3239                 *new_sid = sid;
3240                 goto out_unlock;
3241         }
3242
3243         rc = -EINVAL;
3244         context1 = sidtab_search(sidtab, sid);
3245         if (!context1) {
3246                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3247                         __func__, sid);
3248                 goto out_unlock;
3249         }
3250
3251         rc = -EINVAL;
3252         context2 = sidtab_search(sidtab, mls_sid);
3253         if (!context2) {
3254                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3255                         __func__, mls_sid);
3256                 goto out_unlock;
3257         }
3258
3259         newcon.user = context1->user;
3260         newcon.role = context1->role;
3261         newcon.type = context1->type;
3262         rc = mls_context_cpy(&newcon, context2);
3263         if (rc)
3264                 goto out_unlock;
3265
3266         /* Check the validity of the new context. */
3267         if (!policydb_context_isvalid(policydb, &newcon)) {
3268                 rc = convert_context_handle_invalid_context(state, policydb,
3269                                                         &newcon);
3270                 if (rc) {
3271                         if (!context_struct_to_string(policydb, &newcon, &s,
3272                                                       &len)) {
3273                                 struct audit_buffer *ab;
3274
3275                                 ab = audit_log_start(audit_context(),
3276                                                      GFP_ATOMIC,
3277                                                      AUDIT_SELINUX_ERR);
3278                                 audit_log_format(ab,
3279                                                  "op=security_sid_mls_copy invalid_context=");
3280                                 /* don't record NUL with untrusted strings */
3281                                 audit_log_n_untrustedstring(ab, s, len - 1);
3282                                 audit_log_end(ab);
3283                                 kfree(s);
3284                         }
3285                         goto out_unlock;
3286                 }
3287         }
3288         rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3289         if (rc == -ESTALE) {
3290                 rcu_read_unlock();
3291                 context_destroy(&newcon);
3292                 goto retry;
3293         }
3294 out_unlock:
3295         rcu_read_unlock();
3296         context_destroy(&newcon);
3297         return rc;
3298 }
3299
3300 /**
3301  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3302  * @state: SELinux state
3303  * @nlbl_sid: NetLabel SID
3304  * @nlbl_type: NetLabel labeling protocol type
3305  * @xfrm_sid: XFRM SID
3306  *
3307  * Description:
3308  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3309  * resolved into a single SID it is returned via @peer_sid and the function
3310  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3311  * returns a negative value.  A table summarizing the behavior is below:
3312  *
3313  *                                 | function return |      @sid
3314  *   ------------------------------+-----------------+-----------------
3315  *   no peer labels                |        0        |    SECSID_NULL
3316  *   single peer label             |        0        |    <peer_label>
3317  *   multiple, consistent labels   |        0        |    <peer_label>
3318  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3319  *
3320  */
3321 int security_net_peersid_resolve(struct selinux_state *state,
3322                                  u32 nlbl_sid, u32 nlbl_type,
3323                                  u32 xfrm_sid,
3324                                  u32 *peer_sid)
3325 {
3326         struct selinux_policy *policy;
3327         struct policydb *policydb;
3328         struct sidtab *sidtab;
3329         int rc;
3330         struct context *nlbl_ctx;
3331         struct context *xfrm_ctx;
3332
3333         *peer_sid = SECSID_NULL;
3334
3335         /* handle the common (which also happens to be the set of easy) cases
3336          * right away, these two if statements catch everything involving a
3337          * single or absent peer SID/label */
3338         if (xfrm_sid == SECSID_NULL) {
3339                 *peer_sid = nlbl_sid;
3340                 return 0;
3341         }
3342         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3343          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3344          * is present */
3345         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3346                 *peer_sid = xfrm_sid;
3347                 return 0;
3348         }
3349
3350         if (!selinux_initialized(state))
3351                 return 0;
3352
3353         rcu_read_lock();
3354         policy = rcu_dereference(state->policy);
3355         policydb = &policy->policydb;
3356         sidtab = policy->sidtab;
3357
3358         /*
3359          * We don't need to check initialized here since the only way both
3360          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3361          * security server was initialized and state->initialized was true.
3362          */
3363         if (!policydb->mls_enabled) {
3364                 rc = 0;
3365                 goto out;
3366         }
3367
3368         rc = -EINVAL;
3369         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3370         if (!nlbl_ctx) {
3371                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3372                        __func__, nlbl_sid);
3373                 goto out;
3374         }
3375         rc = -EINVAL;
3376         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3377         if (!xfrm_ctx) {
3378                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3379                        __func__, xfrm_sid);
3380                 goto out;
3381         }
3382         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3383         if (rc)
3384                 goto out;
3385
3386         /* at present NetLabel SIDs/labels really only carry MLS
3387          * information so if the MLS portion of the NetLabel SID
3388          * matches the MLS portion of the labeled XFRM SID/label
3389          * then pass along the XFRM SID as it is the most
3390          * expressive */
3391         *peer_sid = xfrm_sid;
3392 out:
3393         rcu_read_unlock();
3394         return rc;
3395 }
3396
3397 static int get_classes_callback(void *k, void *d, void *args)
3398 {
3399         struct class_datum *datum = d;
3400         char *name = k, **classes = args;
3401         int value = datum->value - 1;
3402
3403         classes[value] = kstrdup(name, GFP_ATOMIC);
3404         if (!classes[value])
3405                 return -ENOMEM;
3406
3407         return 0;
3408 }
3409
3410 int security_get_classes(struct selinux_policy *policy,
3411                          char ***classes, int *nclasses)
3412 {
3413         struct policydb *policydb;
3414         int rc;
3415
3416         policydb = &policy->policydb;
3417
3418         rc = -ENOMEM;
3419         *nclasses = policydb->p_classes.nprim;
3420         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3421         if (!*classes)
3422                 goto out;
3423
3424         rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3425                          *classes);
3426         if (rc) {
3427                 int i;
3428                 for (i = 0; i < *nclasses; i++)
3429                         kfree((*classes)[i]);
3430                 kfree(*classes);
3431         }
3432
3433 out:
3434         return rc;
3435 }
3436
3437 static int get_permissions_callback(void *k, void *d, void *args)
3438 {
3439         struct perm_datum *datum = d;
3440         char *name = k, **perms = args;
3441         int value = datum->value - 1;
3442
3443         perms[value] = kstrdup(name, GFP_ATOMIC);
3444         if (!perms[value])
3445                 return -ENOMEM;
3446
3447         return 0;
3448 }
3449
3450 int security_get_permissions(struct selinux_policy *policy,
3451                              char *class, char ***perms, int *nperms)
3452 {
3453         struct policydb *policydb;
3454         int rc, i;
3455         struct class_datum *match;
3456
3457         policydb = &policy->policydb;
3458
3459         rc = -EINVAL;
3460         match = symtab_search(&policydb->p_classes, class);
3461         if (!match) {
3462                 pr_err("SELinux: %s:  unrecognized class %s\n",
3463                         __func__, class);
3464                 goto out;
3465         }
3466
3467         rc = -ENOMEM;
3468         *nperms = match->permissions.nprim;
3469         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3470         if (!*perms)
3471                 goto out;
3472
3473         if (match->comdatum) {
3474                 rc = hashtab_map(&match->comdatum->permissions.table,
3475                                  get_permissions_callback, *perms);
3476                 if (rc)
3477                         goto err;
3478         }
3479
3480         rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3481                          *perms);
3482         if (rc)
3483                 goto err;
3484
3485 out:
3486         return rc;
3487
3488 err:
3489         for (i = 0; i < *nperms; i++)
3490                 kfree((*perms)[i]);
3491         kfree(*perms);
3492         return rc;
3493 }
3494
3495 int security_get_reject_unknown(struct selinux_state *state)
3496 {
3497         struct selinux_policy *policy;
3498         int value;
3499
3500         if (!selinux_initialized(state))
3501                 return 0;
3502
3503         rcu_read_lock();
3504         policy = rcu_dereference(state->policy);
3505         value = policy->policydb.reject_unknown;
3506         rcu_read_unlock();
3507         return value;
3508 }
3509
3510 int security_get_allow_unknown(struct selinux_state *state)
3511 {
3512         struct selinux_policy *policy;
3513         int value;
3514
3515         if (!selinux_initialized(state))
3516                 return 0;
3517
3518         rcu_read_lock();
3519         policy = rcu_dereference(state->policy);
3520         value = policy->policydb.allow_unknown;
3521         rcu_read_unlock();
3522         return value;
3523 }
3524
3525 /**
3526  * security_policycap_supported - Check for a specific policy capability
3527  * @state: SELinux state
3528  * @req_cap: capability
3529  *
3530  * Description:
3531  * This function queries the currently loaded policy to see if it supports the
3532  * capability specified by @req_cap.  Returns true (1) if the capability is
3533  * supported, false (0) if it isn't supported.
3534  *
3535  */
3536 int security_policycap_supported(struct selinux_state *state,
3537                                  unsigned int req_cap)
3538 {
3539         struct selinux_policy *policy;
3540         int rc;
3541
3542         if (!selinux_initialized(state))
3543                 return 0;
3544
3545         rcu_read_lock();
3546         policy = rcu_dereference(state->policy);
3547         rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3548         rcu_read_unlock();
3549
3550         return rc;
3551 }
3552
3553 struct selinux_audit_rule {
3554         u32 au_seqno;
3555         struct context au_ctxt;
3556 };
3557
3558 void selinux_audit_rule_free(void *vrule)
3559 {
3560         struct selinux_audit_rule *rule = vrule;
3561
3562         if (rule) {
3563                 context_destroy(&rule->au_ctxt);
3564                 kfree(rule);
3565         }
3566 }
3567
3568 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3569 {
3570         struct selinux_state *state = &selinux_state;
3571         struct selinux_policy *policy;
3572         struct policydb *policydb;
3573         struct selinux_audit_rule *tmprule;
3574         struct role_datum *roledatum;
3575         struct type_datum *typedatum;
3576         struct user_datum *userdatum;
3577         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3578         int rc = 0;
3579
3580         *rule = NULL;
3581
3582         if (!selinux_initialized(state))
3583                 return -EOPNOTSUPP;
3584
3585         switch (field) {
3586         case AUDIT_SUBJ_USER:
3587         case AUDIT_SUBJ_ROLE:
3588         case AUDIT_SUBJ_TYPE:
3589         case AUDIT_OBJ_USER:
3590         case AUDIT_OBJ_ROLE:
3591         case AUDIT_OBJ_TYPE:
3592                 /* only 'equals' and 'not equals' fit user, role, and type */
3593                 if (op != Audit_equal && op != Audit_not_equal)
3594                         return -EINVAL;
3595                 break;
3596         case AUDIT_SUBJ_SEN:
3597         case AUDIT_SUBJ_CLR:
3598         case AUDIT_OBJ_LEV_LOW:
3599         case AUDIT_OBJ_LEV_HIGH:
3600                 /* we do not allow a range, indicated by the presence of '-' */
3601                 if (strchr(rulestr, '-'))
3602                         return -EINVAL;
3603                 break;
3604         default:
3605                 /* only the above fields are valid */
3606                 return -EINVAL;
3607         }
3608
3609         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3610         if (!tmprule)
3611                 return -ENOMEM;
3612
3613         context_init(&tmprule->au_ctxt);
3614
3615         rcu_read_lock();
3616         policy = rcu_dereference(state->policy);
3617         policydb = &policy->policydb;
3618
3619         tmprule->au_seqno = policy->latest_granting;
3620
3621         switch (field) {
3622         case AUDIT_SUBJ_USER:
3623         case AUDIT_OBJ_USER:
3624                 rc = -EINVAL;
3625                 userdatum = symtab_search(&policydb->p_users, rulestr);
3626                 if (!userdatum)
3627                         goto out;
3628                 tmprule->au_ctxt.user = userdatum->value;
3629                 break;
3630         case AUDIT_SUBJ_ROLE:
3631         case AUDIT_OBJ_ROLE:
3632                 rc = -EINVAL;
3633                 roledatum = symtab_search(&policydb->p_roles, rulestr);
3634                 if (!roledatum)
3635                         goto out;
3636                 tmprule->au_ctxt.role = roledatum->value;
3637                 break;
3638         case AUDIT_SUBJ_TYPE:
3639         case AUDIT_OBJ_TYPE:
3640                 rc = -EINVAL;
3641                 typedatum = symtab_search(&policydb->p_types, rulestr);
3642                 if (!typedatum)
3643                         goto out;
3644                 tmprule->au_ctxt.type = typedatum->value;
3645                 break;
3646         case AUDIT_SUBJ_SEN:
3647         case AUDIT_SUBJ_CLR:
3648         case AUDIT_OBJ_LEV_LOW:
3649         case AUDIT_OBJ_LEV_HIGH:
3650                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3651                                      GFP_ATOMIC);
3652                 if (rc)
3653                         goto out;
3654                 break;
3655         }
3656         rc = 0;
3657 out:
3658         rcu_read_unlock();
3659
3660         if (rc) {
3661                 selinux_audit_rule_free(tmprule);
3662                 tmprule = NULL;
3663         }
3664
3665         *rule = tmprule;
3666
3667         return rc;
3668 }
3669
3670 /* Check to see if the rule contains any selinux fields */
3671 int selinux_audit_rule_known(struct audit_krule *rule)
3672 {
3673         int i;
3674
3675         for (i = 0; i < rule->field_count; i++) {
3676                 struct audit_field *f = &rule->fields[i];
3677                 switch (f->type) {
3678                 case AUDIT_SUBJ_USER:
3679                 case AUDIT_SUBJ_ROLE:
3680                 case AUDIT_SUBJ_TYPE:
3681                 case AUDIT_SUBJ_SEN:
3682                 case AUDIT_SUBJ_CLR:
3683                 case AUDIT_OBJ_USER:
3684                 case AUDIT_OBJ_ROLE:
3685                 case AUDIT_OBJ_TYPE:
3686                 case AUDIT_OBJ_LEV_LOW:
3687                 case AUDIT_OBJ_LEV_HIGH:
3688                         return 1;
3689                 }
3690         }
3691
3692         return 0;
3693 }
3694
3695 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3696 {
3697         struct selinux_state *state = &selinux_state;
3698         struct selinux_policy *policy;
3699         struct context *ctxt;
3700         struct mls_level *level;
3701         struct selinux_audit_rule *rule = vrule;
3702         int match = 0;
3703
3704         if (unlikely(!rule)) {
3705                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3706                 return -ENOENT;
3707         }
3708
3709         if (!selinux_initialized(state))
3710                 return 0;
3711
3712         rcu_read_lock();
3713
3714         policy = rcu_dereference(state->policy);
3715
3716         if (rule->au_seqno < policy->latest_granting) {
3717                 match = -ESTALE;
3718                 goto out;
3719         }
3720
3721         ctxt = sidtab_search(policy->sidtab, sid);
3722         if (unlikely(!ctxt)) {
3723                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3724                           sid);
3725                 match = -ENOENT;
3726                 goto out;
3727         }
3728
3729         /* a field/op pair that is not caught here will simply fall through
3730            without a match */
3731         switch (field) {
3732         case AUDIT_SUBJ_USER:
3733         case AUDIT_OBJ_USER:
3734                 switch (op) {
3735                 case Audit_equal:
3736                         match = (ctxt->user == rule->au_ctxt.user);
3737                         break;
3738                 case Audit_not_equal:
3739                         match = (ctxt->user != rule->au_ctxt.user);
3740                         break;
3741                 }
3742                 break;
3743         case AUDIT_SUBJ_ROLE:
3744         case AUDIT_OBJ_ROLE:
3745                 switch (op) {
3746                 case Audit_equal:
3747                         match = (ctxt->role == rule->au_ctxt.role);
3748                         break;
3749                 case Audit_not_equal:
3750                         match = (ctxt->role != rule->au_ctxt.role);
3751                         break;
3752                 }
3753                 break;
3754         case AUDIT_SUBJ_TYPE:
3755         case AUDIT_OBJ_TYPE:
3756                 switch (op) {
3757                 case Audit_equal:
3758                         match = (ctxt->type == rule->au_ctxt.type);
3759                         break;
3760                 case Audit_not_equal:
3761                         match = (ctxt->type != rule->au_ctxt.type);
3762                         break;
3763                 }
3764                 break;
3765         case AUDIT_SUBJ_SEN:
3766         case AUDIT_SUBJ_CLR:
3767         case AUDIT_OBJ_LEV_LOW:
3768         case AUDIT_OBJ_LEV_HIGH:
3769                 level = ((field == AUDIT_SUBJ_SEN ||
3770                           field == AUDIT_OBJ_LEV_LOW) ?
3771                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3772                 switch (op) {
3773                 case Audit_equal:
3774                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3775                                              level);
3776                         break;
3777                 case Audit_not_equal:
3778                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3779                                               level);
3780                         break;
3781                 case Audit_lt:
3782                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3783                                                level) &&
3784                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3785                                                level));
3786                         break;
3787                 case Audit_le:
3788                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3789                                               level);
3790                         break;
3791                 case Audit_gt:
3792                         match = (mls_level_dom(level,
3793                                               &rule->au_ctxt.range.level[0]) &&
3794                                  !mls_level_eq(level,
3795                                                &rule->au_ctxt.range.level[0]));
3796                         break;
3797                 case Audit_ge:
3798                         match = mls_level_dom(level,
3799                                               &rule->au_ctxt.range.level[0]);
3800                         break;
3801                 }
3802         }
3803
3804 out:
3805         rcu_read_unlock();
3806         return match;
3807 }
3808
3809 static int aurule_avc_callback(u32 event)
3810 {
3811         if (event == AVC_CALLBACK_RESET)
3812                 return audit_update_lsm_rules();
3813         return 0;
3814 }
3815
3816 static int __init aurule_init(void)
3817 {
3818         int err;
3819
3820         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3821         if (err)
3822                 panic("avc_add_callback() failed, error %d\n", err);
3823
3824         return err;
3825 }
3826 __initcall(aurule_init);
3827
3828 #ifdef CONFIG_NETLABEL
3829 /**
3830  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3831  * @secattr: the NetLabel packet security attributes
3832  * @sid: the SELinux SID
3833  *
3834  * Description:
3835  * Attempt to cache the context in @ctx, which was derived from the packet in
3836  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3837  * already been initialized.
3838  *
3839  */
3840 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3841                                       u32 sid)
3842 {
3843         u32 *sid_cache;
3844
3845         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3846         if (sid_cache == NULL)
3847                 return;
3848         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3849         if (secattr->cache == NULL) {
3850                 kfree(sid_cache);
3851                 return;
3852         }
3853
3854         *sid_cache = sid;
3855         secattr->cache->free = kfree;
3856         secattr->cache->data = sid_cache;
3857         secattr->flags |= NETLBL_SECATTR_CACHE;
3858 }
3859
3860 /**
3861  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3862  * @state: SELinux state
3863  * @secattr: the NetLabel packet security attributes
3864  * @sid: the SELinux SID
3865  *
3866  * Description:
3867  * Convert the given NetLabel security attributes in @secattr into a
3868  * SELinux SID.  If the @secattr field does not contain a full SELinux
3869  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3870  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3871  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3872  * conversion for future lookups.  Returns zero on success, negative values on
3873  * failure.
3874  *
3875  */
3876 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3877                                    struct netlbl_lsm_secattr *secattr,
3878                                    u32 *sid)
3879 {
3880         struct selinux_policy *policy;
3881         struct policydb *policydb;
3882         struct sidtab *sidtab;
3883         int rc;
3884         struct context *ctx;
3885         struct context ctx_new;
3886
3887         if (!selinux_initialized(state)) {
3888                 *sid = SECSID_NULL;
3889                 return 0;
3890         }
3891
3892 retry:
3893         rc = 0;
3894         rcu_read_lock();
3895         policy = rcu_dereference(state->policy);
3896         policydb = &policy->policydb;
3897         sidtab = policy->sidtab;
3898
3899         if (secattr->flags & NETLBL_SECATTR_CACHE)
3900                 *sid = *(u32 *)secattr->cache->data;
3901         else if (secattr->flags & NETLBL_SECATTR_SECID)
3902                 *sid = secattr->attr.secid;
3903         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3904                 rc = -EIDRM;
3905                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3906                 if (ctx == NULL)
3907                         goto out;
3908
3909                 context_init(&ctx_new);
3910                 ctx_new.user = ctx->user;
3911                 ctx_new.role = ctx->role;
3912                 ctx_new.type = ctx->type;
3913                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3914                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3915                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3916                         if (rc)
3917                                 goto out;
3918                 }
3919                 rc = -EIDRM;
3920                 if (!mls_context_isvalid(policydb, &ctx_new)) {
3921                         ebitmap_destroy(&ctx_new.range.level[0].cat);
3922                         goto out;
3923                 }
3924
3925                 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3926                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3927                 if (rc == -ESTALE) {
3928                         rcu_read_unlock();
3929                         goto retry;
3930                 }
3931                 if (rc)
3932                         goto out;
3933
3934                 security_netlbl_cache_add(secattr, *sid);
3935         } else
3936                 *sid = SECSID_NULL;
3937
3938 out:
3939         rcu_read_unlock();
3940         return rc;
3941 }
3942
3943 /**
3944  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3945  * @state: SELinux state
3946  * @sid: the SELinux SID
3947  * @secattr: the NetLabel packet security attributes
3948  *
3949  * Description:
3950  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3951  * Returns zero on success, negative values on failure.
3952  *
3953  */
3954 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3955                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3956 {
3957         struct selinux_policy *policy;
3958         struct policydb *policydb;
3959         int rc;
3960         struct context *ctx;
3961
3962         if (!selinux_initialized(state))
3963                 return 0;
3964
3965         rcu_read_lock();
3966         policy = rcu_dereference(state->policy);
3967         policydb = &policy->policydb;
3968
3969         rc = -ENOENT;
3970         ctx = sidtab_search(policy->sidtab, sid);
3971         if (ctx == NULL)
3972                 goto out;
3973
3974         rc = -ENOMEM;
3975         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3976                                   GFP_ATOMIC);
3977         if (secattr->domain == NULL)
3978                 goto out;
3979
3980         secattr->attr.secid = sid;
3981         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3982         mls_export_netlbl_lvl(policydb, ctx, secattr);
3983         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3984 out:
3985         rcu_read_unlock();
3986         return rc;
3987 }
3988 #endif /* CONFIG_NETLABEL */
3989
3990 /**
3991  * __security_read_policy - read the policy.
3992  * @policy: SELinux policy
3993  * @data: binary policy data
3994  * @len: length of data in bytes
3995  *
3996  */
3997 static int __security_read_policy(struct selinux_policy *policy,
3998                                   void *data, size_t *len)
3999 {
4000         int rc;
4001         struct policy_file fp;
4002
4003         fp.data = data;
4004         fp.len = *len;
4005
4006         rc = policydb_write(&policy->policydb, &fp);
4007         if (rc)
4008                 return rc;
4009
4010         *len = (unsigned long)fp.data - (unsigned long)data;
4011         return 0;
4012 }
4013
4014 /**
4015  * security_read_policy - read the policy.
4016  * @state: selinux_state
4017  * @data: binary policy data
4018  * @len: length of data in bytes
4019  *
4020  */
4021 int security_read_policy(struct selinux_state *state,
4022                          void **data, size_t *len)
4023 {
4024         struct selinux_policy *policy;
4025
4026         policy = rcu_dereference_protected(
4027                         state->policy, lockdep_is_held(&state->policy_mutex));
4028         if (!policy)
4029                 return -EINVAL;
4030
4031         *len = policy->policydb.len;
4032         *data = vmalloc_user(*len);
4033         if (!*data)
4034                 return -ENOMEM;
4035
4036         return __security_read_policy(policy, *data, len);
4037 }
4038
4039 /**
4040  * security_read_state_kernel - read the policy.
4041  * @state: selinux_state
4042  * @data: binary policy data
4043  * @len: length of data in bytes
4044  *
4045  * Allocates kernel memory for reading SELinux policy.
4046  * This function is for internal use only and should not
4047  * be used for returning data to user space.
4048  *
4049  * This function must be called with policy_mutex held.
4050  */
4051 int security_read_state_kernel(struct selinux_state *state,
4052                                void **data, size_t *len)
4053 {
4054         struct selinux_policy *policy;
4055
4056         policy = rcu_dereference_protected(
4057                         state->policy, lockdep_is_held(&state->policy_mutex));
4058         if (!policy)
4059                 return -EINVAL;
4060
4061         *len = policy->policydb.len;
4062         *data = vmalloc(*len);
4063         if (!*data)
4064                 return -ENOMEM;
4065
4066         return __security_read_policy(policy, *data, len);
4067 }