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