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                                const 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                 const 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
 534 /*
 535  * security_boundary_permission - drops violated permissions
 536  * on boundary constraint.
 537  */
 538 static void type_attribute_bounds_av(struct policydb *policydb,
 539                                      struct context *scontext,
 540                                      struct context *tcontext,
 541                                      u16 tclass,
 542                                      struct av_decision *avd)
 543 {
 544         struct context lo_scontext;
 545         struct context lo_tcontext, *tcontextp = tcontext;
 546         struct av_decision lo_avd;
 547         struct type_datum *source;
 548         struct type_datum *target;
 549         u32 masked = 0;
 550
 551         source = policydb->type_val_to_struct[scontext->type - 1];
 552         BUG_ON(!source);
 553
 554         if (!source->bounds)
 555                 return;
 556
 557         target = policydb->type_val_to_struct[tcontext->type - 1];
 558         BUG_ON(!target);
 559
 560         memset(&lo_avd, 0, sizeof(lo_avd));
 561
 562         memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
 563         lo_scontext.type = source->bounds;
 564
 565         if (target->bounds) {
 566                 memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
 567                 lo_tcontext.type = target->bounds;
 568                 tcontextp = &lo_tcontext;
 569         }
 570
 571         context_struct_compute_av(policydb, &lo_scontext,
 572                                   tcontextp,
 573                                   tclass,
 574                                   &lo_avd,
 575                                   NULL);
 576
 577         masked = ~lo_avd.allowed & avd->allowed;
 578
 579         if (likely(!masked))
 580                 return;         /* no masked permission */
 581
 582         /* mask violated permissions */
 583         avd->allowed &= ~masked;
 584
 585         /* audit masked permissions */
 586         security_dump_masked_av(policydb, scontext, tcontext,
 587                                 tclass, masked, "bounds");
 588 }
 589
 590 /*
 591  * flag which drivers have permissions
 592  * only looking for ioctl based extended permssions
 593  */
 594 void services_compute_xperms_drivers(
 595                 struct extended_perms *xperms,
 596                 struct avtab_node *node)
 597 {
 598         unsigned int i;
 599
 600         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 601                 /* if one or more driver has all permissions allowed */
 602                 for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
 603                         xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
 604         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 605                 /* if allowing permissions within a driver */
 606                 security_xperm_set(xperms->drivers.p,
 607                                         node->datum.u.xperms->driver);
 608         }
 609
 610         xperms->len = 1;
 611 }
 612
 613 /*
 614  * Compute access vectors and extended permissions based on a context
 615  * structure pair for the permissions in a particular class.
 616  */
 617 static void context_struct_compute_av(struct policydb *policydb,
 618                                       struct context *scontext,
 619                                       struct context *tcontext,
 620                                       u16 tclass,
 621                                       struct av_decision *avd,
 622                                       struct extended_perms *xperms)
 623 {
 624         struct constraint_node *constraint;
 625         struct role_allow *ra;
 626         struct avtab_key avkey;
 627         struct avtab_node *node;
 628         struct class_datum *tclass_datum;
 629         struct ebitmap *sattr, *tattr;
 630         struct ebitmap_node *snode, *tnode;
 631         unsigned int i, j;
 632
 633         avd->allowed = 0;
 634         avd->auditallow = 0;
 635         avd->auditdeny = 0xffffffff;
 636         if (xperms) {
 637                 memset(&xperms->drivers, 0, sizeof(xperms->drivers));
 638                 xperms->len = 0;
 639         }
 640
 641         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
 642                 if (printk_ratelimit())
 643                         pr_warn("SELinux:  Invalid class %hu\n", tclass);
 644                 return;
 645         }
 646
 647         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 648
 649         /*
 650          * If a specific type enforcement rule was defined for
 651          * this permission check, then use it.
 652          */
 653         avkey.target_class = tclass;
 654         avkey.specified = AVTAB_AV | AVTAB_XPERMS;
 655         sattr = &policydb->type_attr_map_array[scontext->type - 1];
 656         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
 657         ebitmap_for_each_positive_bit(sattr, snode, i) {
 658                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
 659                         avkey.source_type = i + 1;
 660                         avkey.target_type = j + 1;
 661                         for (node = avtab_search_node(&policydb->te_avtab,
 662                                                       &avkey);
 663                              node;
 664                              node = avtab_search_node_next(node, avkey.specified)) {
 665                                 if (node->key.specified == AVTAB_ALLOWED)
 666                                         avd->allowed |= node->datum.u.data;
 667                                 else if (node->key.specified == AVTAB_AUDITALLOW)
 668                                         avd->auditallow |= node->datum.u.data;
 669                                 else if (node->key.specified == AVTAB_AUDITDENY)
 670                                         avd->auditdeny &= node->datum.u.data;
 671                                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
 672                                         services_compute_xperms_drivers(xperms, node);
 673                         }
 674
 675                         /* Check conditional av table for additional permissions */
 676                         cond_compute_av(&policydb->te_cond_avtab, &avkey,
 677                                         avd, xperms);
 678
 679                 }
 680         }
 681
 682         /*
 683          * Remove any permissions prohibited by a constraint (this includes
 684          * the MLS policy).
 685          */
 686         constraint = tclass_datum->constraints;
 687         while (constraint) {
 688                 if ((constraint->permissions & (avd->allowed)) &&
 689                     !constraint_expr_eval(policydb, scontext, tcontext, NULL,
 690                                           constraint->expr)) {
 691                         avd->allowed &= ~(constraint->permissions);
 692                 }
 693                 constraint = constraint->next;
 694         }
 695
 696         /*
 697          * If checking process transition permission and the
 698          * role is changing, then check the (current_role, new_role)
 699          * pair.
 700          */
 701         if (tclass == policydb->process_class &&
 702             (avd->allowed & policydb->process_trans_perms) &&
 703             scontext->role != tcontext->role) {
 704                 for (ra = policydb->role_allow; ra; ra = ra->next) {
 705                         if (scontext->role == ra->role &&
 706                             tcontext->role == ra->new_role)
 707                                 break;
 708                 }
 709                 if (!ra)
 710                         avd->allowed &= ~policydb->process_trans_perms;
 711         }
 712
 713         /*
 714          * If the given source and target types have boundary
 715          * constraint, lazy checks have to mask any violated
 716          * permission and notice it to userspace via audit.
 717          */
 718         type_attribute_bounds_av(policydb, scontext, tcontext,
 719                                  tclass, avd);
 720 }
 721
 722 static int security_validtrans_handle_fail(struct selinux_state *state,
 723                                         struct selinux_policy *policy,
 724                                         struct sidtab_entry *oentry,
 725                                         struct sidtab_entry *nentry,
 726                                         struct sidtab_entry *tentry,
 727                                         u16 tclass)
 728 {
 729         struct policydb *p = &policy->policydb;
 730         struct sidtab *sidtab = policy->sidtab;
 731         char *o = NULL, *n = NULL, *t = NULL;
 732         u32 olen, nlen, tlen;
 733
 734         if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
 735                 goto out;
 736         if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
 737                 goto out;
 738         if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
 739                 goto out;
 740         audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
 741                   "op=security_validate_transition seresult=denied"
 742                   " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 743                   o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
 744 out:
 745         kfree(o);
 746         kfree(n);
 747         kfree(t);
 748
 749         if (!enforcing_enabled(state))
 750                 return 0;
 751         return -EPERM;
 752 }
 753
 754 static int security_compute_validatetrans(struct selinux_state *state,
 755                                           u32 oldsid, u32 newsid, u32 tasksid,
 756                                           u16 orig_tclass, bool user)
 757 {
 758         struct selinux_policy *policy;
 759         struct policydb *policydb;
 760         struct sidtab *sidtab;
 761         struct sidtab_entry *oentry;
 762         struct sidtab_entry *nentry;
 763         struct sidtab_entry *tentry;
 764         struct class_datum *tclass_datum;
 765         struct constraint_node *constraint;
 766         u16 tclass;
 767         int rc = 0;
 768
 769
 770         if (!selinux_initialized(state))
 771                 return 0;
 772
 773         rcu_read_lock();
 774
 775         policy = rcu_dereference(state->policy);
 776         policydb = &policy->policydb;
 777         sidtab = policy->sidtab;
 778
 779         if (!user)
 780                 tclass = unmap_class(&policy->map, orig_tclass);
 781         else
 782                 tclass = orig_tclass;
 783
 784         if (!tclass || tclass > policydb->p_classes.nprim) {
 785                 rc = -EINVAL;
 786                 goto out;
 787         }
 788         tclass_datum = policydb->class_val_to_struct[tclass - 1];
 789
 790         oentry = sidtab_search_entry(sidtab, oldsid);
 791         if (!oentry) {
 792                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 793                         __func__, oldsid);
 794                 rc = -EINVAL;
 795                 goto out;
 796         }
 797
 798         nentry = sidtab_search_entry(sidtab, newsid);
 799         if (!nentry) {
 800                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 801                         __func__, newsid);
 802                 rc = -EINVAL;
 803                 goto out;
 804         }
 805
 806         tentry = sidtab_search_entry(sidtab, tasksid);
 807         if (!tentry) {
 808                 pr_err("SELinux: %s:  unrecognized SID %d\n",
 809                         __func__, tasksid);
 810                 rc = -EINVAL;
 811                 goto out;
 812         }
 813
 814         constraint = tclass_datum->validatetrans;
 815         while (constraint) {
 816                 if (!constraint_expr_eval(policydb, &oentry->context,
 817                                           &nentry->context, &tentry->context,
 818                                           constraint->expr)) {
 819                         if (user)
 820                                 rc = -EPERM;
 821                         else
 822                                 rc = security_validtrans_handle_fail(state,
 823                                                                 policy,
 824                                                                 oentry,
 825                                                                 nentry,
 826                                                                 tentry,
 827                                                                 tclass);
 828                         goto out;
 829                 }
 830                 constraint = constraint->next;
 831         }
 832
 833 out:
 834         rcu_read_unlock();
 835         return rc;
 836 }
 837
 838 int security_validate_transition_user(struct selinux_state *state,
 839                                       u32 oldsid, u32 newsid, u32 tasksid,
 840                                       u16 tclass)
 841 {
 842         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 843                                               tclass, true);
 844 }
 845
 846 int security_validate_transition(struct selinux_state *state,
 847                                  u32 oldsid, u32 newsid, u32 tasksid,
 848                                  u16 orig_tclass)
 849 {
 850         return security_compute_validatetrans(state, oldsid, newsid, tasksid,
 851                                               orig_tclass, false);
 852 }
 853
 854 /*
 855  * security_bounded_transition - check whether the given
 856  * transition is directed to bounded, or not.
 857  * It returns 0, if @newsid is bounded by @oldsid.
 858  * Otherwise, it returns error code.
 859  *
 860  * @state: SELinux state
 861  * @oldsid : current security identifier
 862  * @newsid : destinated security identifier
 863  */
 864 int security_bounded_transition(struct selinux_state *state,
 865                                 u32 old_sid, u32 new_sid)
 866 {
 867         struct selinux_policy *policy;
 868         struct policydb *policydb;
 869         struct sidtab *sidtab;
 870         struct sidtab_entry *old_entry, *new_entry;
 871         struct type_datum *type;
 872         int index;
 873         int rc;
 874
 875         if (!selinux_initialized(state))
 876                 return 0;
 877
 878         rcu_read_lock();
 879         policy = rcu_dereference(state->policy);
 880         policydb = &policy->policydb;
 881         sidtab = policy->sidtab;
 882
 883         rc = -EINVAL;
 884         old_entry = sidtab_search_entry(sidtab, old_sid);
 885         if (!old_entry) {
 886                 pr_err("SELinux: %s: unrecognized SID %u\n",
 887                        __func__, old_sid);
 888                 goto out;
 889         }
 890
 891         rc = -EINVAL;
 892         new_entry = sidtab_search_entry(sidtab, new_sid);
 893         if (!new_entry) {
 894                 pr_err("SELinux: %s: unrecognized SID %u\n",
 895                        __func__, new_sid);
 896                 goto out;
 897         }
 898
 899         rc = 0;
 900         /* type/domain unchanged */
 901         if (old_entry->context.type == new_entry->context.type)
 902                 goto out;
 903
 904         index = new_entry->context.type;
 905         while (true) {
 906                 type = policydb->type_val_to_struct[index - 1];
 907                 BUG_ON(!type);
 908
 909                 /* not bounded anymore */
 910                 rc = -EPERM;
 911                 if (!type->bounds)
 912                         break;
 913
 914                 /* @newsid is bounded by @oldsid */
 915                 rc = 0;
 916                 if (type->bounds == old_entry->context.type)
 917                         break;
 918
 919                 index = type->bounds;
 920         }
 921
 922         if (rc) {
 923                 char *old_name = NULL;
 924                 char *new_name = NULL;
 925                 u32 length;
 926
 927                 if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
 928                                             &old_name, &length) &&
 929                     !sidtab_entry_to_string(policydb, sidtab, new_entry,
 930                                             &new_name, &length)) {
 931                         audit_log(audit_context(),
 932                                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
 933                                   "op=security_bounded_transition "
 934                                   "seresult=denied "
 935                                   "oldcontext=%s newcontext=%s",
 936                                   old_name, new_name);
 937                 }
 938                 kfree(new_name);
 939                 kfree(old_name);
 940         }
 941 out:
 942         rcu_read_unlock();
 943
 944         return rc;
 945 }
 946
 947 static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
 948 {
 949         avd->allowed = 0;
 950         avd->auditallow = 0;
 951         avd->auditdeny = 0xffffffff;
 952         if (policy)
 953                 avd->seqno = policy->latest_granting;
 954         else
 955                 avd->seqno = 0;
 956         avd->flags = 0;
 957 }
 958
 959 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
 960                                         struct avtab_node *node)
 961 {
 962         unsigned int i;
 963
 964         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 965                 if (xpermd->driver != node->datum.u.xperms->driver)
 966                         return;
 967         } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 968                 if (!security_xperm_test(node->datum.u.xperms->perms.p,
 969                                         xpermd->driver))
 970                         return;
 971         } else {
 972                 BUG();
 973         }
 974
 975         if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
 976                 xpermd->used |= XPERMS_ALLOWED;
 977                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 978                         memset(xpermd->allowed->p, 0xff,
 979                                         sizeof(xpermd->allowed->p));
 980                 }
 981                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 982                         for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
 983                                 xpermd->allowed->p[i] |=
 984                                         node->datum.u.xperms->perms.p[i];
 985                 }
 986         } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
 987                 xpermd->used |= XPERMS_AUDITALLOW;
 988                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
 989                         memset(xpermd->auditallow->p, 0xff,
 990                                         sizeof(xpermd->auditallow->p));
 991                 }
 992                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
 993                         for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
 994                                 xpermd->auditallow->p[i] |=
 995                                         node->datum.u.xperms->perms.p[i];
 996                 }
 997         } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
 998                 xpermd->used |= XPERMS_DONTAUDIT;
 999                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
1000                         memset(xpermd->dontaudit->p, 0xff,
1001                                         sizeof(xpermd->dontaudit->p));
1002                 }
1003                 if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
1004                         for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
1005                                 xpermd->dontaudit->p[i] |=
1006                                         node->datum.u.xperms->perms.p[i];
1007                 }
1008         } else {
1009                 BUG();
1010         }
1011 }
1012
1013 void security_compute_xperms_decision(struct selinux_state *state,
1014                                       u32 ssid,
1015                                       u32 tsid,
1016                                       u16 orig_tclass,
1017                                       u8 driver,
1018                                       struct extended_perms_decision *xpermd)
1019 {
1020         struct selinux_policy *policy;
1021         struct policydb *policydb;
1022         struct sidtab *sidtab;
1023         u16 tclass;
1024         struct context *scontext, *tcontext;
1025         struct avtab_key avkey;
1026         struct avtab_node *node;
1027         struct ebitmap *sattr, *tattr;
1028         struct ebitmap_node *snode, *tnode;
1029         unsigned int i, j;
1030
1031         xpermd->driver = driver;
1032         xpermd->used = 0;
1033         memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
1034         memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
1035         memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
1036
1037         rcu_read_lock();
1038         if (!selinux_initialized(state))
1039                 goto allow;
1040
1041         policy = rcu_dereference(state->policy);
1042         policydb = &policy->policydb;
1043         sidtab = policy->sidtab;
1044
1045         scontext = sidtab_search(sidtab, ssid);
1046         if (!scontext) {
1047                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1048                        __func__, ssid);
1049                 goto out;
1050         }
1051
1052         tcontext = sidtab_search(sidtab, tsid);
1053         if (!tcontext) {
1054                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1055                        __func__, tsid);
1056                 goto out;
1057         }
1058
1059         tclass = unmap_class(&policy->map, orig_tclass);
1060         if (unlikely(orig_tclass && !tclass)) {
1061                 if (policydb->allow_unknown)
1062                         goto allow;
1063                 goto out;
1064         }
1065
1066
1067         if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
1068                 pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
1069                 goto out;
1070         }
1071
1072         avkey.target_class = tclass;
1073         avkey.specified = AVTAB_XPERMS;
1074         sattr = &policydb->type_attr_map_array[scontext->type - 1];
1075         tattr = &policydb->type_attr_map_array[tcontext->type - 1];
1076         ebitmap_for_each_positive_bit(sattr, snode, i) {
1077                 ebitmap_for_each_positive_bit(tattr, tnode, j) {
1078                         avkey.source_type = i + 1;
1079                         avkey.target_type = j + 1;
1080                         for (node = avtab_search_node(&policydb->te_avtab,
1081                                                       &avkey);
1082                              node;
1083                              node = avtab_search_node_next(node, avkey.specified))
1084                                 services_compute_xperms_decision(xpermd, node);
1085
1086                         cond_compute_xperms(&policydb->te_cond_avtab,
1087                                                 &avkey, xpermd);
1088                 }
1089         }
1090 out:
1091         rcu_read_unlock();
1092         return;
1093 allow:
1094         memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
1095         goto out;
1096 }
1097
1098 /**
1099  * security_compute_av - Compute access vector decisions.
1100  * @state: SELinux state
1101  * @ssid: source security identifier
1102  * @tsid: target security identifier
1103  * @orig_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  * @state: SELinux state
1390  * @sid: security identifier, SID
1391  * @scontext: security context
1392  * @scontext_len: length in bytes
1393  *
1394  * Write the string representation of the context associated with @sid
1395  * into a dynamically allocated string of the correct size.  Set @scontext
1396  * to point to this string and set @scontext_len to the length of the string.
1397  */
1398 int security_sid_to_context(struct selinux_state *state,
1399                             u32 sid, char **scontext, u32 *scontext_len)
1400 {
1401         return security_sid_to_context_core(state, sid, scontext,
1402                                             scontext_len, 0, 0);
1403 }
1404
1405 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
1406                                   char **scontext, u32 *scontext_len)
1407 {
1408         return security_sid_to_context_core(state, sid, scontext,
1409                                             scontext_len, 1, 0);
1410 }
1411
1412 /**
1413  * security_sid_to_context_inval - Obtain a context for a given SID if it
1414  *                                 is invalid.
1415  * @state: SELinux state
1416  * @sid: security identifier, SID
1417  * @scontext: security context
1418  * @scontext_len: length in bytes
1419  *
1420  * Write the string representation of the context associated with @sid
1421  * into a dynamically allocated string of the correct size, but only if the
1422  * context is invalid in the current policy.  Set @scontext to point to
1423  * this string (or NULL if the context is valid) and set @scontext_len to
1424  * the length of the string (or 0 if the context is valid).
1425  */
1426 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
1427                                   char **scontext, u32 *scontext_len)
1428 {
1429         return security_sid_to_context_core(state, sid, scontext,
1430                                             scontext_len, 1, 1);
1431 }
1432
1433 /*
1434  * Caveat:  Mutates scontext.
1435  */
1436 static int string_to_context_struct(struct policydb *pol,
1437                                     struct sidtab *sidtabp,
1438                                     char *scontext,
1439                                     struct context *ctx,
1440                                     u32 def_sid)
1441 {
1442         struct role_datum *role;
1443         struct type_datum *typdatum;
1444         struct user_datum *usrdatum;
1445         char *scontextp, *p, oldc;
1446         int rc = 0;
1447
1448         context_init(ctx);
1449
1450         /* Parse the security context. */
1451
1452         rc = -EINVAL;
1453         scontextp = scontext;
1454
1455         /* Extract the user. */
1456         p = scontextp;
1457         while (*p && *p != ':')
1458                 p++;
1459
1460         if (*p == 0)
1461                 goto out;
1462
1463         *p++ = 0;
1464
1465         usrdatum = symtab_search(&pol->p_users, scontextp);
1466         if (!usrdatum)
1467                 goto out;
1468
1469         ctx->user = usrdatum->value;
1470
1471         /* Extract role. */
1472         scontextp = p;
1473         while (*p && *p != ':')
1474                 p++;
1475
1476         if (*p == 0)
1477                 goto out;
1478
1479         *p++ = 0;
1480
1481         role = symtab_search(&pol->p_roles, scontextp);
1482         if (!role)
1483                 goto out;
1484         ctx->role = role->value;
1485
1486         /* Extract type. */
1487         scontextp = p;
1488         while (*p && *p != ':')
1489                 p++;
1490         oldc = *p;
1491         *p++ = 0;
1492
1493         typdatum = symtab_search(&pol->p_types, scontextp);
1494         if (!typdatum || typdatum->attribute)
1495                 goto out;
1496
1497         ctx->type = typdatum->value;
1498
1499         rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
1500         if (rc)
1501                 goto out;
1502
1503         /* Check the validity of the new context. */
1504         rc = -EINVAL;
1505         if (!policydb_context_isvalid(pol, ctx))
1506                 goto out;
1507         rc = 0;
1508 out:
1509         if (rc)
1510                 context_destroy(ctx);
1511         return rc;
1512 }
1513
1514 static int security_context_to_sid_core(struct selinux_state *state,
1515                                         const char *scontext, u32 scontext_len,
1516                                         u32 *sid, u32 def_sid, gfp_t gfp_flags,
1517                                         int force)
1518 {
1519         struct selinux_policy *policy;
1520         struct policydb *policydb;
1521         struct sidtab *sidtab;
1522         char *scontext2, *str = NULL;
1523         struct context context;
1524         int rc = 0;
1525
1526         /* An empty security context is never valid. */
1527         if (!scontext_len)
1528                 return -EINVAL;
1529
1530         /* Copy the string to allow changes and ensure a NUL terminator */
1531         scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
1532         if (!scontext2)
1533                 return -ENOMEM;
1534
1535         if (!selinux_initialized(state)) {
1536                 int i;
1537
1538                 for (i = 1; i < SECINITSID_NUM; i++) {
1539                         const char *s = initial_sid_to_string[i];
1540
1541                         if (s && !strcmp(s, scontext2)) {
1542                                 *sid = i;
1543                                 goto out;
1544                         }
1545                 }
1546                 *sid = SECINITSID_KERNEL;
1547                 goto out;
1548         }
1549         *sid = SECSID_NULL;
1550
1551         if (force) {
1552                 /* Save another copy for storing in uninterpreted form */
1553                 rc = -ENOMEM;
1554                 str = kstrdup(scontext2, gfp_flags);
1555                 if (!str)
1556                         goto out;
1557         }
1558 retry:
1559         rcu_read_lock();
1560         policy = rcu_dereference(state->policy);
1561         policydb = &policy->policydb;
1562         sidtab = policy->sidtab;
1563         rc = string_to_context_struct(policydb, sidtab, scontext2,
1564                                       &context, def_sid);
1565         if (rc == -EINVAL && force) {
1566                 context.str = str;
1567                 context.len = strlen(str) + 1;
1568                 str = NULL;
1569         } else if (rc)
1570                 goto out_unlock;
1571         rc = sidtab_context_to_sid(sidtab, &context, sid);
1572         if (rc == -ESTALE) {
1573                 rcu_read_unlock();
1574                 if (context.str) {
1575                         str = context.str;
1576                         context.str = NULL;
1577                 }
1578                 context_destroy(&context);
1579                 goto retry;
1580         }
1581         context_destroy(&context);
1582 out_unlock:
1583         rcu_read_unlock();
1584 out:
1585         kfree(scontext2);
1586         kfree(str);
1587         return rc;
1588 }
1589
1590 /**
1591  * security_context_to_sid - Obtain a SID for a given security context.
1592  * @state: SELinux state
1593  * @scontext: security context
1594  * @scontext_len: length in bytes
1595  * @sid: security identifier, SID
1596  * @gfp: context for the allocation
1597  *
1598  * Obtains a SID associated with the security context that
1599  * has the string representation specified by @scontext.
1600  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1601  * memory is available, or 0 on success.
1602  */
1603 int security_context_to_sid(struct selinux_state *state,
1604                             const char *scontext, u32 scontext_len, u32 *sid,
1605                             gfp_t gfp)
1606 {
1607         return security_context_to_sid_core(state, scontext, scontext_len,
1608                                             sid, SECSID_NULL, gfp, 0);
1609 }
1610
1611 int security_context_str_to_sid(struct selinux_state *state,
1612                                 const char *scontext, u32 *sid, gfp_t gfp)
1613 {
1614         return security_context_to_sid(state, scontext, strlen(scontext),
1615                                        sid, gfp);
1616 }
1617
1618 /**
1619  * security_context_to_sid_default - Obtain a SID for a given security context,
1620  * falling back to specified default if needed.
1621  *
1622  * @state: SELinux state
1623  * @scontext: security context
1624  * @scontext_len: length in bytes
1625  * @sid: security identifier, SID
1626  * @def_sid: default SID to assign on error
1627  * @gfp_flags: the allocator get-free-page (GFP) flags
1628  *
1629  * Obtains a SID associated with the security context that
1630  * has the string representation specified by @scontext.
1631  * The default SID is passed to the MLS layer to be used to allow
1632  * kernel labeling of the MLS field if the MLS field is not present
1633  * (for upgrading to MLS without full relabel).
1634  * Implicitly forces adding of the context even if it cannot be mapped yet.
1635  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
1636  * memory is available, or 0 on success.
1637  */
1638 int security_context_to_sid_default(struct selinux_state *state,
1639                                     const char *scontext, u32 scontext_len,
1640                                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
1641 {
1642         return security_context_to_sid_core(state, scontext, scontext_len,
1643                                             sid, def_sid, gfp_flags, 1);
1644 }
1645
1646 int security_context_to_sid_force(struct selinux_state *state,
1647                                   const char *scontext, u32 scontext_len,
1648                                   u32 *sid)
1649 {
1650         return security_context_to_sid_core(state, scontext, scontext_len,
1651                                             sid, SECSID_NULL, GFP_KERNEL, 1);
1652 }
1653
1654 static int compute_sid_handle_invalid_context(
1655         struct selinux_state *state,
1656         struct selinux_policy *policy,
1657         struct sidtab_entry *sentry,
1658         struct sidtab_entry *tentry,
1659         u16 tclass,
1660         struct context *newcontext)
1661 {
1662         struct policydb *policydb = &policy->policydb;
1663         struct sidtab *sidtab = policy->sidtab;
1664         char *s = NULL, *t = NULL, *n = NULL;
1665         u32 slen, tlen, nlen;
1666         struct audit_buffer *ab;
1667
1668         if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
1669                 goto out;
1670         if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
1671                 goto out;
1672         if (context_struct_to_string(policydb, newcontext, &n, &nlen))
1673                 goto out;
1674         ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
1675         if (!ab)
1676                 goto out;
1677         audit_log_format(ab,
1678                          "op=security_compute_sid invalid_context=");
1679         /* no need to record the NUL with untrusted strings */
1680         audit_log_n_untrustedstring(ab, n, nlen - 1);
1681         audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
1682                          s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
1683         audit_log_end(ab);
1684 out:
1685         kfree(s);
1686         kfree(t);
1687         kfree(n);
1688         if (!enforcing_enabled(state))
1689                 return 0;
1690         return -EACCES;
1691 }
1692
1693 static void filename_compute_type(struct policydb *policydb,
1694                                   struct context *newcontext,
1695                                   u32 stype, u32 ttype, u16 tclass,
1696                                   const char *objname)
1697 {
1698         struct filename_trans_key ft;
1699         struct filename_trans_datum *datum;
1700
1701         /*
1702          * Most filename trans rules are going to live in specific directories
1703          * like /dev or /var/run.  This bitmap will quickly skip rule searches
1704          * if the ttype does not contain any rules.
1705          */
1706         if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
1707                 return;
1708
1709         ft.ttype = ttype;
1710         ft.tclass = tclass;
1711         ft.name = objname;
1712
1713         datum = policydb_filenametr_search(policydb, &ft);
1714         while (datum) {
1715                 if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
1716                         newcontext->type = datum->otype;
1717                         return;
1718                 }
1719                 datum = datum->next;
1720         }
1721 }
1722
1723 static int security_compute_sid(struct selinux_state *state,
1724                                 u32 ssid,
1725                                 u32 tsid,
1726                                 u16 orig_tclass,
1727                                 u32 specified,
1728                                 const char *objname,
1729                                 u32 *out_sid,
1730                                 bool kern)
1731 {
1732         struct selinux_policy *policy;
1733         struct policydb *policydb;
1734         struct sidtab *sidtab;
1735         struct class_datum *cladatum;
1736         struct context *scontext, *tcontext, newcontext;
1737         struct sidtab_entry *sentry, *tentry;
1738         struct avtab_key avkey;
1739         struct avtab_datum *avdatum;
1740         struct avtab_node *node;
1741         u16 tclass;
1742         int rc = 0;
1743         bool sock;
1744
1745         if (!selinux_initialized(state)) {
1746                 switch (orig_tclass) {
1747                 case SECCLASS_PROCESS: /* kernel value */
1748                         *out_sid = ssid;
1749                         break;
1750                 default:
1751                         *out_sid = tsid;
1752                         break;
1753                 }
1754                 goto out;
1755         }
1756
1757 retry:
1758         cladatum = NULL;
1759         context_init(&newcontext);
1760
1761         rcu_read_lock();
1762
1763         policy = rcu_dereference(state->policy);
1764
1765         if (kern) {
1766                 tclass = unmap_class(&policy->map, orig_tclass);
1767                 sock = security_is_socket_class(orig_tclass);
1768         } else {
1769                 tclass = orig_tclass;
1770                 sock = security_is_socket_class(map_class(&policy->map,
1771                                                           tclass));
1772         }
1773
1774         policydb = &policy->policydb;
1775         sidtab = policy->sidtab;
1776
1777         sentry = sidtab_search_entry(sidtab, ssid);
1778         if (!sentry) {
1779                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1780                        __func__, ssid);
1781                 rc = -EINVAL;
1782                 goto out_unlock;
1783         }
1784         tentry = sidtab_search_entry(sidtab, tsid);
1785         if (!tentry) {
1786                 pr_err("SELinux: %s:  unrecognized SID %d\n",
1787                        __func__, tsid);
1788                 rc = -EINVAL;
1789                 goto out_unlock;
1790         }
1791
1792         scontext = &sentry->context;
1793         tcontext = &tentry->context;
1794
1795         if (tclass && tclass <= policydb->p_classes.nprim)
1796                 cladatum = policydb->class_val_to_struct[tclass - 1];
1797
1798         /* Set the user identity. */
1799         switch (specified) {
1800         case AVTAB_TRANSITION:
1801         case AVTAB_CHANGE:
1802                 if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
1803                         newcontext.user = tcontext->user;
1804                 } else {
1805                         /* notice this gets both DEFAULT_SOURCE and unset */
1806                         /* Use the process user identity. */
1807                         newcontext.user = scontext->user;
1808                 }
1809                 break;
1810         case AVTAB_MEMBER:
1811                 /* Use the related object owner. */
1812                 newcontext.user = tcontext->user;
1813                 break;
1814         }
1815
1816         /* Set the role to default values. */
1817         if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
1818                 newcontext.role = scontext->role;
1819         } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
1820                 newcontext.role = tcontext->role;
1821         } else {
1822                 if ((tclass == policydb->process_class) || sock)
1823                         newcontext.role = scontext->role;
1824                 else
1825                         newcontext.role = OBJECT_R_VAL;
1826         }
1827
1828         /* Set the type to default values. */
1829         if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
1830                 newcontext.type = scontext->type;
1831         } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
1832                 newcontext.type = tcontext->type;
1833         } else {
1834                 if ((tclass == policydb->process_class) || sock) {
1835                         /* Use the type of process. */
1836                         newcontext.type = scontext->type;
1837                 } else {
1838                         /* Use the type of the related object. */
1839                         newcontext.type = tcontext->type;
1840                 }
1841         }
1842
1843         /* Look for a type transition/member/change rule. */
1844         avkey.source_type = scontext->type;
1845         avkey.target_type = tcontext->type;
1846         avkey.target_class = tclass;
1847         avkey.specified = specified;
1848         avdatum = avtab_search(&policydb->te_avtab, &avkey);
1849
1850         /* If no permanent rule, also check for enabled conditional rules */
1851         if (!avdatum) {
1852                 node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
1853                 for (; node; node = avtab_search_node_next(node, specified)) {
1854                         if (node->key.specified & AVTAB_ENABLED) {
1855                                 avdatum = &node->datum;
1856                                 break;
1857                         }
1858                 }
1859         }
1860
1861         if (avdatum) {
1862                 /* Use the type from the type transition/member/change rule. */
1863                 newcontext.type = avdatum->u.data;
1864         }
1865
1866         /* if we have a objname this is a file trans check so check those rules */
1867         if (objname)
1868                 filename_compute_type(policydb, &newcontext, scontext->type,
1869                                       tcontext->type, tclass, objname);
1870
1871         /* Check for class-specific changes. */
1872         if (specified & AVTAB_TRANSITION) {
1873                 /* Look for a role transition rule. */
1874                 struct role_trans_datum *rtd;
1875                 struct role_trans_key rtk = {
1876                         .role = scontext->role,
1877                         .type = tcontext->type,
1878                         .tclass = tclass,
1879                 };
1880
1881                 rtd = policydb_roletr_search(policydb, &rtk);
1882                 if (rtd)
1883                         newcontext.role = rtd->new_role;
1884         }
1885
1886         /* Set the MLS attributes.
1887            This is done last because it may allocate memory. */
1888         rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
1889                              &newcontext, sock);
1890         if (rc)
1891                 goto out_unlock;
1892
1893         /* Check the validity of the context. */
1894         if (!policydb_context_isvalid(policydb, &newcontext)) {
1895                 rc = compute_sid_handle_invalid_context(state, policy, sentry,
1896                                                         tentry, tclass,
1897                                                         &newcontext);
1898                 if (rc)
1899                         goto out_unlock;
1900         }
1901         /* Obtain the sid for the context. */
1902         rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
1903         if (rc == -ESTALE) {
1904                 rcu_read_unlock();
1905                 context_destroy(&newcontext);
1906                 goto retry;
1907         }
1908 out_unlock:
1909         rcu_read_unlock();
1910         context_destroy(&newcontext);
1911 out:
1912         return rc;
1913 }
1914
1915 /**
1916  * security_transition_sid - Compute the SID for a new subject/object.
1917  * @state: SELinux state
1918  * @ssid: source security identifier
1919  * @tsid: target security identifier
1920  * @tclass: target security class
1921  * @qstr: object name
1922  * @out_sid: security identifier for new subject/object
1923  *
1924  * Compute a SID to use for labeling a new subject or object in the
1925  * class @tclass based on a SID pair (@ssid, @tsid).
1926  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1927  * if insufficient memory is available, or %0 if the new SID was
1928  * computed successfully.
1929  */
1930 int security_transition_sid(struct selinux_state *state,
1931                             u32 ssid, u32 tsid, u16 tclass,
1932                             const struct qstr *qstr, u32 *out_sid)
1933 {
1934         return security_compute_sid(state, ssid, tsid, tclass,
1935                                     AVTAB_TRANSITION,
1936                                     qstr ? qstr->name : NULL, out_sid, true);
1937 }
1938
1939 int security_transition_sid_user(struct selinux_state *state,
1940                                  u32 ssid, u32 tsid, u16 tclass,
1941                                  const char *objname, u32 *out_sid)
1942 {
1943         return security_compute_sid(state, ssid, tsid, tclass,
1944                                     AVTAB_TRANSITION,
1945                                     objname, out_sid, false);
1946 }
1947
1948 /**
1949  * security_member_sid - Compute the SID for member selection.
1950  * @state: SELinux state
1951  * @ssid: source security identifier
1952  * @tsid: target security identifier
1953  * @tclass: target security class
1954  * @out_sid: security identifier for selected member
1955  *
1956  * Compute a SID to use when selecting a member of a polyinstantiated
1957  * object of class @tclass based on a SID pair (@ssid, @tsid).
1958  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1959  * if insufficient memory is available, or %0 if the SID was
1960  * computed successfully.
1961  */
1962 int security_member_sid(struct selinux_state *state,
1963                         u32 ssid,
1964                         u32 tsid,
1965                         u16 tclass,
1966                         u32 *out_sid)
1967 {
1968         return security_compute_sid(state, ssid, tsid, tclass,
1969                                     AVTAB_MEMBER, NULL,
1970                                     out_sid, false);
1971 }
1972
1973 /**
1974  * security_change_sid - Compute the SID for object relabeling.
1975  * @state: SELinux state
1976  * @ssid: source security identifier
1977  * @tsid: target security identifier
1978  * @tclass: target security class
1979  * @out_sid: security identifier for selected member
1980  *
1981  * Compute a SID to use for relabeling an object of class @tclass
1982  * based on a SID pair (@ssid, @tsid).
1983  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1984  * if insufficient memory is available, or %0 if the SID was
1985  * computed successfully.
1986  */
1987 int security_change_sid(struct selinux_state *state,
1988                         u32 ssid,
1989                         u32 tsid,
1990                         u16 tclass,
1991                         u32 *out_sid)
1992 {
1993         return security_compute_sid(state,
1994                                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
1995                                     out_sid, false);
1996 }
1997
1998 static inline int convert_context_handle_invalid_context(
1999         struct selinux_state *state,
2000         struct policydb *policydb,
2001         struct context *context)
2002 {
2003         char *s;
2004         u32 len;
2005
2006         if (enforcing_enabled(state))
2007                 return -EINVAL;
2008
2009         if (!context_struct_to_string(policydb, context, &s, &len)) {
2010                 pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
2011                         s);
2012                 kfree(s);
2013         }
2014         return 0;
2015 }
2016
2017 /*
2018  * Convert the values in the security context
2019  * structure `oldc' from the values specified
2020  * in the policy `p->oldp' to the values specified
2021  * in the policy `p->newp', storing the new context
2022  * in `newc'.  Verify that the context is valid
2023  * under the new policy.
2024  */
2025 static int convert_context(struct context *oldc, struct context *newc, void *p)
2026 {
2027         struct convert_context_args *args;
2028         struct ocontext *oc;
2029         struct role_datum *role;
2030         struct type_datum *typdatum;
2031         struct user_datum *usrdatum;
2032         char *s;
2033         u32 len;
2034         int rc;
2035
2036         args = p;
2037
2038         if (oldc->str) {
2039                 s = kstrdup(oldc->str, GFP_KERNEL);
2040                 if (!s)
2041                         return -ENOMEM;
2042
2043                 rc = string_to_context_struct(args->newp, NULL, s,
2044                                               newc, SECSID_NULL);
2045                 if (rc == -EINVAL) {
2046                         /*
2047                          * Retain string representation for later mapping.
2048                          *
2049                          * IMPORTANT: We need to copy the contents of oldc->str
2050                          * back into s again because string_to_context_struct()
2051                          * may have garbled it.
2052                          */
2053                         memcpy(s, oldc->str, oldc->len);
2054                         context_init(newc);
2055                         newc->str = s;
2056                         newc->len = oldc->len;
2057                         return 0;
2058                 }
2059                 kfree(s);
2060                 if (rc) {
2061                         /* Other error condition, e.g. ENOMEM. */
2062                         pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
2063                                oldc->str, -rc);
2064                         return rc;
2065                 }
2066                 pr_info("SELinux:  Context %s became valid (mapped).\n",
2067                         oldc->str);
2068                 return 0;
2069         }
2070
2071         context_init(newc);
2072
2073         /* Convert the user. */
2074         usrdatum = symtab_search(&args->newp->p_users,
2075                                  sym_name(args->oldp,
2076                                           SYM_USERS, oldc->user - 1));
2077         if (!usrdatum)
2078                 goto bad;
2079         newc->user = usrdatum->value;
2080
2081         /* Convert the role. */
2082         role = symtab_search(&args->newp->p_roles,
2083                              sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
2084         if (!role)
2085                 goto bad;
2086         newc->role = role->value;
2087
2088         /* Convert the type. */
2089         typdatum = symtab_search(&args->newp->p_types,
2090                                  sym_name(args->oldp,
2091                                           SYM_TYPES, oldc->type - 1));
2092         if (!typdatum)
2093                 goto bad;
2094         newc->type = typdatum->value;
2095
2096         /* Convert the MLS fields if dealing with MLS policies */
2097         if (args->oldp->mls_enabled && args->newp->mls_enabled) {
2098                 rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
2099                 if (rc)
2100                         goto bad;
2101         } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
2102                 /*
2103                  * Switching between non-MLS and MLS policy:
2104                  * ensure that the MLS fields of the context for all
2105                  * existing entries in the sidtab are filled in with a
2106                  * suitable default value, likely taken from one of the
2107                  * initial SIDs.
2108                  */
2109                 oc = args->newp->ocontexts[OCON_ISID];
2110                 while (oc && oc->sid[0] != SECINITSID_UNLABELED)
2111                         oc = oc->next;
2112                 if (!oc) {
2113                         pr_err("SELinux:  unable to look up"
2114                                 " the initial SIDs list\n");
2115                         goto bad;
2116                 }
2117                 rc = mls_range_set(newc, &oc->context[0].range);
2118                 if (rc)
2119                         goto bad;
2120         }
2121
2122         /* Check the validity of the new context. */
2123         if (!policydb_context_isvalid(args->newp, newc)) {
2124                 rc = convert_context_handle_invalid_context(args->state,
2125                                                         args->oldp,
2126                                                         oldc);
2127                 if (rc)
2128                         goto bad;
2129         }
2130
2131         return 0;
2132 bad:
2133         /* Map old representation to string and save it. */
2134         rc = context_struct_to_string(args->oldp, oldc, &s, &len);
2135         if (rc)
2136                 return rc;
2137         context_destroy(newc);
2138         newc->str = s;
2139         newc->len = len;
2140         pr_info("SELinux:  Context %s became invalid (unmapped).\n",
2141                 newc->str);
2142         return 0;
2143 }
2144
2145 static void security_load_policycaps(struct selinux_state *state,
2146                                 struct selinux_policy *policy)
2147 {
2148         struct policydb *p;
2149         unsigned int i;
2150         struct ebitmap_node *node;
2151
2152         p = &policy->policydb;
2153
2154         for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
2155                 WRITE_ONCE(state->policycap[i],
2156                         ebitmap_get_bit(&p->policycaps, i));
2157
2158         for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
2159                 pr_info("SELinux:  policy capability %s=%d\n",
2160                         selinux_policycap_names[i],
2161                         ebitmap_get_bit(&p->policycaps, i));
2162
2163         ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
2164                 if (i >= ARRAY_SIZE(selinux_policycap_names))
2165                         pr_info("SELinux:  unknown policy capability %u\n",
2166                                 i);
2167         }
2168 }
2169
2170 static int security_preserve_bools(struct selinux_policy *oldpolicy,
2171                                 struct selinux_policy *newpolicy);
2172
2173 static void selinux_policy_free(struct selinux_policy *policy)
2174 {
2175         if (!policy)
2176                 return;
2177
2178         sidtab_destroy(policy->sidtab);
2179         kfree(policy->map.mapping);
2180         policydb_destroy(&policy->policydb);
2181         kfree(policy->sidtab);
2182         kfree(policy);
2183 }
2184
2185 static void selinux_policy_cond_free(struct selinux_policy *policy)
2186 {
2187         cond_policydb_destroy_dup(&policy->policydb);
2188         kfree(policy);
2189 }
2190
2191 void selinux_policy_cancel(struct selinux_state *state,
2192                            struct selinux_load_state *load_state)
2193 {
2194         struct selinux_policy *oldpolicy;
2195
2196         oldpolicy = rcu_dereference_protected(state->policy,
2197                                         lockdep_is_held(&state->policy_mutex));
2198
2199         sidtab_cancel_convert(oldpolicy->sidtab);
2200         selinux_policy_free(load_state->policy);
2201         kfree(load_state->convert_data);
2202 }
2203
2204 static void selinux_notify_policy_change(struct selinux_state *state,
2205                                         u32 seqno)
2206 {
2207         /* Flush external caches and notify userspace of policy load */
2208         avc_ss_reset(state->avc, seqno);
2209         selnl_notify_policyload(seqno);
2210         selinux_status_update_policyload(state, seqno);
2211         selinux_netlbl_cache_invalidate();
2212         selinux_xfrm_notify_policyload();
2213         selinux_ima_measure_state_locked(state);
2214 }
2215
2216 void selinux_policy_commit(struct selinux_state *state,
2217                            struct selinux_load_state *load_state)
2218 {
2219         struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
2220         unsigned long flags;
2221         u32 seqno;
2222
2223         oldpolicy = rcu_dereference_protected(state->policy,
2224                                         lockdep_is_held(&state->policy_mutex));
2225
2226         /* If switching between different policy types, log MLS status */
2227         if (oldpolicy) {
2228                 if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
2229                         pr_info("SELinux: Disabling MLS support...\n");
2230                 else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
2231                         pr_info("SELinux: Enabling MLS support...\n");
2232         }
2233
2234         /* Set latest granting seqno for new policy. */
2235         if (oldpolicy)
2236                 newpolicy->latest_granting = oldpolicy->latest_granting + 1;
2237         else
2238                 newpolicy->latest_granting = 1;
2239         seqno = newpolicy->latest_granting;
2240
2241         /* Install the new policy. */
2242         if (oldpolicy) {
2243                 sidtab_freeze_begin(oldpolicy->sidtab, &flags);
2244                 rcu_assign_pointer(state->policy, newpolicy);
2245                 sidtab_freeze_end(oldpolicy->sidtab, &flags);
2246         } else {
2247                 rcu_assign_pointer(state->policy, newpolicy);
2248         }
2249
2250         /* Load the policycaps from the new policy */
2251         security_load_policycaps(state, newpolicy);
2252
2253         if (!selinux_initialized(state)) {
2254                 /*
2255                  * After first policy load, the security server is
2256                  * marked as initialized and ready to handle requests and
2257                  * any objects created prior to policy load are then labeled.
2258                  */
2259                 selinux_mark_initialized(state);
2260                 selinux_complete_init();
2261         }
2262
2263         /* Free the old policy */
2264         synchronize_rcu();
2265         selinux_policy_free(oldpolicy);
2266         kfree(load_state->convert_data);
2267
2268         /* Notify others of the policy change */
2269         selinux_notify_policy_change(state, seqno);
2270 }
2271
2272 /**
2273  * security_load_policy - Load a security policy configuration.
2274  * @state: SELinux state
2275  * @data: binary policy data
2276  * @len: length of data in bytes
2277  * @load_state: policy load state
2278  *
2279  * Load a new set of security policy configuration data,
2280  * validate it and convert the SID table as necessary.
2281  * This function will flush the access vector cache after
2282  * loading the new policy.
2283  */
2284 int security_load_policy(struct selinux_state *state, void *data, size_t len,
2285                          struct selinux_load_state *load_state)
2286 {
2287         struct selinux_policy *newpolicy, *oldpolicy;
2288         struct selinux_policy_convert_data *convert_data;
2289         int rc = 0;
2290         struct policy_file file = { data, len }, *fp = &file;
2291
2292         newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
2293         if (!newpolicy)
2294                 return -ENOMEM;
2295
2296         newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
2297         if (!newpolicy->sidtab) {
2298                 rc = -ENOMEM;
2299                 goto err_policy;
2300         }
2301
2302         rc = policydb_read(&newpolicy->policydb, fp);
2303         if (rc)
2304                 goto err_sidtab;
2305
2306         newpolicy->policydb.len = len;
2307         rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
2308                                 &newpolicy->map);
2309         if (rc)
2310                 goto err_policydb;
2311
2312         rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
2313         if (rc) {
2314                 pr_err("SELinux:  unable to load the initial SIDs\n");
2315                 goto err_mapping;
2316         }
2317
2318         if (!selinux_initialized(state)) {
2319                 /* First policy load, so no need to preserve state from old policy */
2320                 load_state->policy = newpolicy;
2321                 load_state->convert_data = NULL;
2322                 return 0;
2323         }
2324
2325         oldpolicy = rcu_dereference_protected(state->policy,
2326                                         lockdep_is_held(&state->policy_mutex));
2327
2328         /* Preserve active boolean values from the old policy */
2329         rc = security_preserve_bools(oldpolicy, newpolicy);
2330         if (rc) {
2331                 pr_err("SELinux:  unable to preserve booleans\n");
2332                 goto err_free_isids;
2333         }
2334
2335         convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
2336         if (!convert_data) {
2337                 rc = -ENOMEM;
2338                 goto err_free_isids;
2339         }
2340
2341         /*
2342          * Convert the internal representations of contexts
2343          * in the new SID table.
2344          */
2345         convert_data->args.state = state;
2346         convert_data->args.oldp = &oldpolicy->policydb;
2347         convert_data->args.newp = &newpolicy->policydb;
2348
2349         convert_data->sidtab_params.func = convert_context;
2350         convert_data->sidtab_params.args = &convert_data->args;
2351         convert_data->sidtab_params.target = newpolicy->sidtab;
2352
2353         rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
2354         if (rc) {
2355                 pr_err("SELinux:  unable to convert the internal"
2356                         " representation of contexts in the new SID"
2357                         " table\n");
2358                 goto err_free_convert_data;
2359         }
2360
2361         load_state->policy = newpolicy;
2362         load_state->convert_data = convert_data;
2363         return 0;
2364
2365 err_free_convert_data:
2366         kfree(convert_data);
2367 err_free_isids:
2368         sidtab_destroy(newpolicy->sidtab);
2369 err_mapping:
2370         kfree(newpolicy->map.mapping);
2371 err_policydb:
2372         policydb_destroy(&newpolicy->policydb);
2373 err_sidtab:
2374         kfree(newpolicy->sidtab);
2375 err_policy:
2376         kfree(newpolicy);
2377
2378         return rc;
2379 }
2380
2381 /**
2382  * ocontext_to_sid - Helper to safely get sid for an ocontext
2383  * @sidtab: SID table
2384  * @c: ocontext structure
2385  * @index: index of the context entry (0 or 1)
2386  * @out_sid: pointer to the resulting SID value
2387  *
2388  * For all ocontexts except OCON_ISID the SID fields are populated
2389  * on-demand when needed. Since updating the SID value is an SMP-sensitive
2390  * operation, this helper must be used to do that safely.
2391  *
2392  * WARNING: This function may return -ESTALE, indicating that the caller
2393  * must retry the operation after re-acquiring the policy pointer!
2394  */
2395 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
2396                            size_t index, u32 *out_sid)
2397 {
2398         int rc;
2399         u32 sid;
2400
2401         /* Ensure the associated sidtab entry is visible to this thread. */
2402         sid = smp_load_acquire(&c->sid[index]);
2403         if (!sid) {
2404                 rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
2405                 if (rc)
2406                         return rc;
2407
2408                 /*
2409                  * Ensure the new sidtab entry is visible to other threads
2410                  * when they see the SID.
2411                  */
2412                 smp_store_release(&c->sid[index], sid);
2413         }
2414         *out_sid = sid;
2415         return 0;
2416 }
2417
2418 /**
2419  * security_port_sid - Obtain the SID for a port.
2420  * @state: SELinux state
2421  * @protocol: protocol number
2422  * @port: port number
2423  * @out_sid: security identifier
2424  */
2425 int security_port_sid(struct selinux_state *state,
2426                       u8 protocol, u16 port, u32 *out_sid)
2427 {
2428         struct selinux_policy *policy;
2429         struct policydb *policydb;
2430         struct sidtab *sidtab;
2431         struct ocontext *c;
2432         int rc;
2433
2434         if (!selinux_initialized(state)) {
2435                 *out_sid = SECINITSID_PORT;
2436                 return 0;
2437         }
2438
2439 retry:
2440         rc = 0;
2441         rcu_read_lock();
2442         policy = rcu_dereference(state->policy);
2443         policydb = &policy->policydb;
2444         sidtab = policy->sidtab;
2445
2446         c = policydb->ocontexts[OCON_PORT];
2447         while (c) {
2448                 if (c->u.port.protocol == protocol &&
2449                     c->u.port.low_port <= port &&
2450                     c->u.port.high_port >= port)
2451                         break;
2452                 c = c->next;
2453         }
2454
2455         if (c) {
2456                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2457                 if (rc == -ESTALE) {
2458                         rcu_read_unlock();
2459                         goto retry;
2460                 }
2461                 if (rc)
2462                         goto out;
2463         } else {
2464                 *out_sid = SECINITSID_PORT;
2465         }
2466
2467 out:
2468         rcu_read_unlock();
2469         return rc;
2470 }
2471
2472 /**
2473  * security_ib_pkey_sid - Obtain the SID for a pkey.
2474  * @state: SELinux state
2475  * @subnet_prefix: Subnet Prefix
2476  * @pkey_num: pkey number
2477  * @out_sid: security identifier
2478  */
2479 int security_ib_pkey_sid(struct selinux_state *state,
2480                          u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
2481 {
2482         struct selinux_policy *policy;
2483         struct policydb *policydb;
2484         struct sidtab *sidtab;
2485         struct ocontext *c;
2486         int rc;
2487
2488         if (!selinux_initialized(state)) {
2489                 *out_sid = SECINITSID_UNLABELED;
2490                 return 0;
2491         }
2492
2493 retry:
2494         rc = 0;
2495         rcu_read_lock();
2496         policy = rcu_dereference(state->policy);
2497         policydb = &policy->policydb;
2498         sidtab = policy->sidtab;
2499
2500         c = policydb->ocontexts[OCON_IBPKEY];
2501         while (c) {
2502                 if (c->u.ibpkey.low_pkey <= pkey_num &&
2503                     c->u.ibpkey.high_pkey >= pkey_num &&
2504                     c->u.ibpkey.subnet_prefix == subnet_prefix)
2505                         break;
2506
2507                 c = c->next;
2508         }
2509
2510         if (c) {
2511                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2512                 if (rc == -ESTALE) {
2513                         rcu_read_unlock();
2514                         goto retry;
2515                 }
2516                 if (rc)
2517                         goto out;
2518         } else
2519                 *out_sid = SECINITSID_UNLABELED;
2520
2521 out:
2522         rcu_read_unlock();
2523         return rc;
2524 }
2525
2526 /**
2527  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
2528  * @state: SELinux state
2529  * @dev_name: device name
2530  * @port_num: port number
2531  * @out_sid: security identifier
2532  */
2533 int security_ib_endport_sid(struct selinux_state *state,
2534                             const char *dev_name, u8 port_num, u32 *out_sid)
2535 {
2536         struct selinux_policy *policy;
2537         struct policydb *policydb;
2538         struct sidtab *sidtab;
2539         struct ocontext *c;
2540         int rc;
2541
2542         if (!selinux_initialized(state)) {
2543                 *out_sid = SECINITSID_UNLABELED;
2544                 return 0;
2545         }
2546
2547 retry:
2548         rc = 0;
2549         rcu_read_lock();
2550         policy = rcu_dereference(state->policy);
2551         policydb = &policy->policydb;
2552         sidtab = policy->sidtab;
2553
2554         c = policydb->ocontexts[OCON_IBENDPORT];
2555         while (c) {
2556                 if (c->u.ibendport.port == port_num &&
2557                     !strncmp(c->u.ibendport.dev_name,
2558                              dev_name,
2559                              IB_DEVICE_NAME_MAX))
2560                         break;
2561
2562                 c = c->next;
2563         }
2564
2565         if (c) {
2566                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2567                 if (rc == -ESTALE) {
2568                         rcu_read_unlock();
2569                         goto retry;
2570                 }
2571                 if (rc)
2572                         goto out;
2573         } else
2574                 *out_sid = SECINITSID_UNLABELED;
2575
2576 out:
2577         rcu_read_unlock();
2578         return rc;
2579 }
2580
2581 /**
2582  * security_netif_sid - Obtain the SID for a network interface.
2583  * @state: SELinux state
2584  * @name: interface name
2585  * @if_sid: interface SID
2586  */
2587 int security_netif_sid(struct selinux_state *state,
2588                        char *name, u32 *if_sid)
2589 {
2590         struct selinux_policy *policy;
2591         struct policydb *policydb;
2592         struct sidtab *sidtab;
2593         int rc;
2594         struct ocontext *c;
2595
2596         if (!selinux_initialized(state)) {
2597                 *if_sid = SECINITSID_NETIF;
2598                 return 0;
2599         }
2600
2601 retry:
2602         rc = 0;
2603         rcu_read_lock();
2604         policy = rcu_dereference(state->policy);
2605         policydb = &policy->policydb;
2606         sidtab = policy->sidtab;
2607
2608         c = policydb->ocontexts[OCON_NETIF];
2609         while (c) {
2610                 if (strcmp(name, c->u.name) == 0)
2611                         break;
2612                 c = c->next;
2613         }
2614
2615         if (c) {
2616                 rc = ocontext_to_sid(sidtab, c, 0, if_sid);
2617                 if (rc == -ESTALE) {
2618                         rcu_read_unlock();
2619                         goto retry;
2620                 }
2621                 if (rc)
2622                         goto out;
2623         } else
2624                 *if_sid = SECINITSID_NETIF;
2625
2626 out:
2627         rcu_read_unlock();
2628         return rc;
2629 }
2630
2631 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
2632 {
2633         int i, fail = 0;
2634
2635         for (i = 0; i < 4; i++)
2636                 if (addr[i] != (input[i] & mask[i])) {
2637                         fail = 1;
2638                         break;
2639                 }
2640
2641         return !fail;
2642 }
2643
2644 /**
2645  * security_node_sid - Obtain the SID for a node (host).
2646  * @state: SELinux state
2647  * @domain: communication domain aka address family
2648  * @addrp: address
2649  * @addrlen: address length in bytes
2650  * @out_sid: security identifier
2651  */
2652 int security_node_sid(struct selinux_state *state,
2653                       u16 domain,
2654                       void *addrp,
2655                       u32 addrlen,
2656                       u32 *out_sid)
2657 {
2658         struct selinux_policy *policy;
2659         struct policydb *policydb;
2660         struct sidtab *sidtab;
2661         int rc;
2662         struct ocontext *c;
2663
2664         if (!selinux_initialized(state)) {
2665                 *out_sid = SECINITSID_NODE;
2666                 return 0;
2667         }
2668
2669 retry:
2670         rcu_read_lock();
2671         policy = rcu_dereference(state->policy);
2672         policydb = &policy->policydb;
2673         sidtab = policy->sidtab;
2674
2675         switch (domain) {
2676         case AF_INET: {
2677                 u32 addr;
2678
2679                 rc = -EINVAL;
2680                 if (addrlen != sizeof(u32))
2681                         goto out;
2682
2683                 addr = *((u32 *)addrp);
2684
2685                 c = policydb->ocontexts[OCON_NODE];
2686                 while (c) {
2687                         if (c->u.node.addr == (addr & c->u.node.mask))
2688                                 break;
2689                         c = c->next;
2690                 }
2691                 break;
2692         }
2693
2694         case AF_INET6:
2695                 rc = -EINVAL;
2696                 if (addrlen != sizeof(u64) * 2)
2697                         goto out;
2698                 c = policydb->ocontexts[OCON_NODE6];
2699                 while (c) {
2700                         if (match_ipv6_addrmask(addrp, c->u.node6.addr,
2701                                                 c->u.node6.mask))
2702                                 break;
2703                         c = c->next;
2704                 }
2705                 break;
2706
2707         default:
2708                 rc = 0;
2709                 *out_sid = SECINITSID_NODE;
2710                 goto out;
2711         }
2712
2713         if (c) {
2714                 rc = ocontext_to_sid(sidtab, c, 0, out_sid);
2715                 if (rc == -ESTALE) {
2716                         rcu_read_unlock();
2717                         goto retry;
2718                 }
2719                 if (rc)
2720                         goto out;
2721         } else {
2722                 *out_sid = SECINITSID_NODE;
2723         }
2724
2725         rc = 0;
2726 out:
2727         rcu_read_unlock();
2728         return rc;
2729 }
2730
2731 #define SIDS_NEL 25
2732
2733 /**
2734  * security_get_user_sids - Obtain reachable SIDs for a user.
2735  * @state: SELinux state
2736  * @fromsid: starting SID
2737  * @username: username
2738  * @sids: array of reachable SIDs for user
2739  * @nel: number of elements in @sids
2740  *
2741  * Generate the set of SIDs for legal security contexts
2742  * for a given user that can be reached by @fromsid.
2743  * Set *@sids to point to a dynamically allocated
2744  * array containing the set of SIDs.  Set *@nel to the
2745  * number of elements in the array.
2746  */
2747
2748 int security_get_user_sids(struct selinux_state *state,
2749                            u32 fromsid,
2750                            char *username,
2751                            u32 **sids,
2752                            u32 *nel)
2753 {
2754         struct selinux_policy *policy;
2755         struct policydb *policydb;
2756         struct sidtab *sidtab;
2757         struct context *fromcon, usercon;
2758         u32 *mysids = NULL, *mysids2, sid;
2759         u32 i, j, mynel, maxnel = SIDS_NEL;
2760         struct user_datum *user;
2761         struct role_datum *role;
2762         struct ebitmap_node *rnode, *tnode;
2763         int rc;
2764
2765         *sids = NULL;
2766         *nel = 0;
2767
2768         if (!selinux_initialized(state))
2769                 return 0;
2770
2771         mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
2772         if (!mysids)
2773                 return -ENOMEM;
2774
2775 retry:
2776         mynel = 0;
2777         rcu_read_lock();
2778         policy = rcu_dereference(state->policy);
2779         policydb = &policy->policydb;
2780         sidtab = policy->sidtab;
2781
2782         context_init(&usercon);
2783
2784         rc = -EINVAL;
2785         fromcon = sidtab_search(sidtab, fromsid);
2786         if (!fromcon)
2787                 goto out_unlock;
2788
2789         rc = -EINVAL;
2790         user = symtab_search(&policydb->p_users, username);
2791         if (!user)
2792                 goto out_unlock;
2793
2794         usercon.user = user->value;
2795
2796         ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
2797                 role = policydb->role_val_to_struct[i];
2798                 usercon.role = i + 1;
2799                 ebitmap_for_each_positive_bit(&role->types, tnode, j) {
2800                         usercon.type = j + 1;
2801
2802                         if (mls_setup_user_range(policydb, fromcon, user,
2803                                                  &usercon))
2804                                 continue;
2805
2806                         rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
2807                         if (rc == -ESTALE) {
2808                                 rcu_read_unlock();
2809                                 goto retry;
2810                         }
2811                         if (rc)
2812                                 goto out_unlock;
2813                         if (mynel < maxnel) {
2814                                 mysids[mynel++] = sid;
2815                         } else {
2816                                 rc = -ENOMEM;
2817                                 maxnel += SIDS_NEL;
2818                                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
2819                                 if (!mysids2)
2820                                         goto out_unlock;
2821                                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
2822                                 kfree(mysids);
2823                                 mysids = mysids2;
2824                                 mysids[mynel++] = sid;
2825                         }
2826                 }
2827         }
2828         rc = 0;
2829 out_unlock:
2830         rcu_read_unlock();
2831         if (rc || !mynel) {
2832                 kfree(mysids);
2833                 return rc;
2834         }
2835
2836         rc = -ENOMEM;
2837         mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
2838         if (!mysids2) {
2839                 kfree(mysids);
2840                 return rc;
2841         }
2842         for (i = 0, j = 0; i < mynel; i++) {
2843                 struct av_decision dummy_avd;
2844                 rc = avc_has_perm_noaudit(state,
2845                                           fromsid, mysids[i],
2846                                           SECCLASS_PROCESS, /* kernel value */
2847                                           PROCESS__TRANSITION, AVC_STRICT,
2848                                           &dummy_avd);
2849                 if (!rc)
2850                         mysids2[j++] = mysids[i];
2851                 cond_resched();
2852         }
2853         kfree(mysids);
2854         *sids = mysids2;
2855         *nel = j;
2856         return 0;
2857 }
2858
2859 /**
2860  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
2861  * @policy: policy
2862  * @fstype: filesystem type
2863  * @path: path from root of mount
2864  * @orig_sclass: file security class
2865  * @sid: SID for path
2866  *
2867  * Obtain a SID to use for a file in a filesystem that
2868  * cannot support xattr or use a fixed labeling behavior like
2869  * transition SIDs or task SIDs.
2870  *
2871  * WARNING: This function may return -ESTALE, indicating that the caller
2872  * must retry the operation after re-acquiring the policy pointer!
2873  */
2874 static inline int __security_genfs_sid(struct selinux_policy *policy,
2875                                        const char *fstype,
2876                                        const char *path,
2877                                        u16 orig_sclass,
2878                                        u32 *sid)
2879 {
2880         struct policydb *policydb = &policy->policydb;
2881         struct sidtab *sidtab = policy->sidtab;
2882         int len;
2883         u16 sclass;
2884         struct genfs *genfs;
2885         struct ocontext *c;
2886         int cmp = 0;
2887
2888         while (path[0] == '/' && path[1] == '/')
2889                 path++;
2890
2891         sclass = unmap_class(&policy->map, orig_sclass);
2892         *sid = SECINITSID_UNLABELED;
2893
2894         for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
2895                 cmp = strcmp(fstype, genfs->fstype);
2896                 if (cmp <= 0)
2897                         break;
2898         }
2899
2900         if (!genfs || cmp)
2901                 return -ENOENT;
2902
2903         for (c = genfs->head; c; c = c->next) {
2904                 len = strlen(c->u.name);
2905                 if ((!c->v.sclass || sclass == c->v.sclass) &&
2906                     (strncmp(c->u.name, path, len) == 0))
2907                         break;
2908         }
2909
2910         if (!c)
2911                 return -ENOENT;
2912
2913         return ocontext_to_sid(sidtab, c, 0, sid);
2914 }
2915
2916 /**
2917  * security_genfs_sid - Obtain a SID for a file in a filesystem
2918  * @state: SELinux state
2919  * @fstype: filesystem type
2920  * @path: path from root of mount
2921  * @orig_sclass: file security class
2922  * @sid: SID for path
2923  *
2924  * Acquire policy_rwlock before calling __security_genfs_sid() and release
2925  * it afterward.
2926  */
2927 int security_genfs_sid(struct selinux_state *state,
2928                        const char *fstype,
2929                        const char *path,
2930                        u16 orig_sclass,
2931                        u32 *sid)
2932 {
2933         struct selinux_policy *policy;
2934         int retval;
2935
2936         if (!selinux_initialized(state)) {
2937                 *sid = SECINITSID_UNLABELED;
2938                 return 0;
2939         }
2940
2941         do {
2942                 rcu_read_lock();
2943                 policy = rcu_dereference(state->policy);
2944                 retval = __security_genfs_sid(policy, fstype, path,
2945                                               orig_sclass, sid);
2946                 rcu_read_unlock();
2947         } while (retval == -ESTALE);
2948         return retval;
2949 }
2950
2951 int selinux_policy_genfs_sid(struct selinux_policy *policy,
2952                         const char *fstype,
2953                         const char *path,
2954                         u16 orig_sclass,
2955                         u32 *sid)
2956 {
2957         /* no lock required, policy is not yet accessible by other threads */
2958         return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
2959 }
2960
2961 /**
2962  * security_fs_use - Determine how to handle labeling for a filesystem.
2963  * @state: SELinux state
2964  * @sb: superblock in question
2965  */
2966 int security_fs_use(struct selinux_state *state, struct super_block *sb)
2967 {
2968         struct selinux_policy *policy;
2969         struct policydb *policydb;
2970         struct sidtab *sidtab;
2971         int rc;
2972         struct ocontext *c;
2973         struct superblock_security_struct *sbsec = selinux_superblock(sb);
2974         const char *fstype = sb->s_type->name;
2975
2976         if (!selinux_initialized(state)) {
2977                 sbsec->behavior = SECURITY_FS_USE_NONE;
2978                 sbsec->sid = SECINITSID_UNLABELED;
2979                 return 0;
2980         }
2981
2982 retry:
2983         rcu_read_lock();
2984         policy = rcu_dereference(state->policy);
2985         policydb = &policy->policydb;
2986         sidtab = policy->sidtab;
2987
2988         c = policydb->ocontexts[OCON_FSUSE];
2989         while (c) {
2990                 if (strcmp(fstype, c->u.name) == 0)
2991                         break;
2992                 c = c->next;
2993         }
2994
2995         if (c) {
2996                 sbsec->behavior = c->v.behavior;
2997                 rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
2998                 if (rc == -ESTALE) {
2999                         rcu_read_unlock();
3000                         goto retry;
3001                 }
3002                 if (rc)
3003                         goto out;
3004         } else {
3005                 rc = __security_genfs_sid(policy, fstype, "/",
3006                                         SECCLASS_DIR, &sbsec->sid);
3007                 if (rc == -ESTALE) {
3008                         rcu_read_unlock();
3009                         goto retry;
3010                 }
3011                 if (rc) {
3012                         sbsec->behavior = SECURITY_FS_USE_NONE;
3013                         rc = 0;
3014                 } else {
3015                         sbsec->behavior = SECURITY_FS_USE_GENFS;
3016                 }
3017         }
3018
3019 out:
3020         rcu_read_unlock();
3021         return rc;
3022 }
3023
3024 int security_get_bools(struct selinux_policy *policy,
3025                        u32 *len, char ***names, int **values)
3026 {
3027         struct policydb *policydb;
3028         u32 i;
3029         int rc;
3030
3031         policydb = &policy->policydb;
3032
3033         *names = NULL;
3034         *values = NULL;
3035
3036         rc = 0;
3037         *len = policydb->p_bools.nprim;
3038         if (!*len)
3039                 goto out;
3040
3041         rc = -ENOMEM;
3042         *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
3043         if (!*names)
3044                 goto err;
3045
3046         rc = -ENOMEM;
3047         *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
3048         if (!*values)
3049                 goto err;
3050
3051         for (i = 0; i < *len; i++) {
3052                 (*values)[i] = policydb->bool_val_to_struct[i]->state;
3053
3054                 rc = -ENOMEM;
3055                 (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
3056                                       GFP_ATOMIC);
3057                 if (!(*names)[i])
3058                         goto err;
3059         }
3060         rc = 0;
3061 out:
3062         return rc;
3063 err:
3064         if (*names) {
3065                 for (i = 0; i < *len; i++)
3066                         kfree((*names)[i]);
3067                 kfree(*names);
3068         }
3069         kfree(*values);
3070         *len = 0;
3071         *names = NULL;
3072         *values = NULL;
3073         goto out;
3074 }
3075
3076
3077 int security_set_bools(struct selinux_state *state, u32 len, int *values)
3078 {
3079         struct selinux_policy *newpolicy, *oldpolicy;
3080         int rc;
3081         u32 i, seqno = 0;
3082
3083         if (!selinux_initialized(state))
3084                 return -EINVAL;
3085
3086         oldpolicy = rcu_dereference_protected(state->policy,
3087                                         lockdep_is_held(&state->policy_mutex));
3088
3089         /* Consistency check on number of booleans, should never fail */
3090         if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
3091                 return -EINVAL;
3092
3093         newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
3094         if (!newpolicy)
3095                 return -ENOMEM;
3096
3097         /*
3098          * Deep copy only the parts of the policydb that might be
3099          * modified as a result of changing booleans.
3100          */
3101         rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
3102         if (rc) {
3103                 kfree(newpolicy);
3104                 return -ENOMEM;
3105         }
3106
3107         /* Update the boolean states in the copy */
3108         for (i = 0; i < len; i++) {
3109                 int new_state = !!values[i];
3110                 int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
3111
3112                 if (new_state != old_state) {
3113                         audit_log(audit_context(), GFP_ATOMIC,
3114                                 AUDIT_MAC_CONFIG_CHANGE,
3115                                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
3116                                 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
3117                                 new_state,
3118                                 old_state,
3119                                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
3120                                 audit_get_sessionid(current));
3121                         newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
3122                 }
3123         }
3124
3125         /* Re-evaluate the conditional rules in the copy */
3126         evaluate_cond_nodes(&newpolicy->policydb);
3127
3128         /* Set latest granting seqno for new policy */
3129         newpolicy->latest_granting = oldpolicy->latest_granting + 1;
3130         seqno = newpolicy->latest_granting;
3131
3132         /* Install the new policy */
3133         rcu_assign_pointer(state->policy, newpolicy);
3134
3135         /*
3136          * Free the conditional portions of the old policydb
3137          * that were copied for the new policy, and the oldpolicy
3138          * structure itself but not what it references.
3139          */
3140         synchronize_rcu();
3141         selinux_policy_cond_free(oldpolicy);
3142
3143         /* Notify others of the policy change */
3144         selinux_notify_policy_change(state, seqno);
3145         return 0;
3146 }
3147
3148 int security_get_bool_value(struct selinux_state *state,
3149                             u32 index)
3150 {
3151         struct selinux_policy *policy;
3152         struct policydb *policydb;
3153         int rc;
3154         u32 len;
3155
3156         if (!selinux_initialized(state))
3157                 return 0;
3158
3159         rcu_read_lock();
3160         policy = rcu_dereference(state->policy);
3161         policydb = &policy->policydb;
3162
3163         rc = -EFAULT;
3164         len = policydb->p_bools.nprim;
3165         if (index >= len)
3166                 goto out;
3167
3168         rc = policydb->bool_val_to_struct[index]->state;
3169 out:
3170         rcu_read_unlock();
3171         return rc;
3172 }
3173
3174 static int security_preserve_bools(struct selinux_policy *oldpolicy,
3175                                 struct selinux_policy *newpolicy)
3176 {
3177         int rc, *bvalues = NULL;
3178         char **bnames = NULL;
3179         struct cond_bool_datum *booldatum;
3180         u32 i, nbools = 0;
3181
3182         rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
3183         if (rc)
3184                 goto out;
3185         for (i = 0; i < nbools; i++) {
3186                 booldatum = symtab_search(&newpolicy->policydb.p_bools,
3187                                         bnames[i]);
3188                 if (booldatum)
3189                         booldatum->state = bvalues[i];
3190         }
3191         evaluate_cond_nodes(&newpolicy->policydb);
3192
3193 out:
3194         if (bnames) {
3195                 for (i = 0; i < nbools; i++)
3196                         kfree(bnames[i]);
3197         }
3198         kfree(bnames);
3199         kfree(bvalues);
3200         return rc;
3201 }
3202
3203 /*
3204  * security_sid_mls_copy() - computes a new sid based on the given
3205  * sid and the mls portion of mls_sid.
3206  */
3207 int security_sid_mls_copy(struct selinux_state *state,
3208                           u32 sid, u32 mls_sid, u32 *new_sid)
3209 {
3210         struct selinux_policy *policy;
3211         struct policydb *policydb;
3212         struct sidtab *sidtab;
3213         struct context *context1;
3214         struct context *context2;
3215         struct context newcon;
3216         char *s;
3217         u32 len;
3218         int rc;
3219
3220         if (!selinux_initialized(state)) {
3221                 *new_sid = sid;
3222                 return 0;
3223         }
3224
3225 retry:
3226         rc = 0;
3227         context_init(&newcon);
3228
3229         rcu_read_lock();
3230         policy = rcu_dereference(state->policy);
3231         policydb = &policy->policydb;
3232         sidtab = policy->sidtab;
3233
3234         if (!policydb->mls_enabled) {
3235                 *new_sid = sid;
3236                 goto out_unlock;
3237         }
3238
3239         rc = -EINVAL;
3240         context1 = sidtab_search(sidtab, sid);
3241         if (!context1) {
3242                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3243                         __func__, sid);
3244                 goto out_unlock;
3245         }
3246
3247         rc = -EINVAL;
3248         context2 = sidtab_search(sidtab, mls_sid);
3249         if (!context2) {
3250                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3251                         __func__, mls_sid);
3252                 goto out_unlock;
3253         }
3254
3255         newcon.user = context1->user;
3256         newcon.role = context1->role;
3257         newcon.type = context1->type;
3258         rc = mls_context_cpy(&newcon, context2);
3259         if (rc)
3260                 goto out_unlock;
3261
3262         /* Check the validity of the new context. */
3263         if (!policydb_context_isvalid(policydb, &newcon)) {
3264                 rc = convert_context_handle_invalid_context(state, policydb,
3265                                                         &newcon);
3266                 if (rc) {
3267                         if (!context_struct_to_string(policydb, &newcon, &s,
3268                                                       &len)) {
3269                                 struct audit_buffer *ab;
3270
3271                                 ab = audit_log_start(audit_context(),
3272                                                      GFP_ATOMIC,
3273                                                      AUDIT_SELINUX_ERR);
3274                                 audit_log_format(ab,
3275                                                  "op=security_sid_mls_copy invalid_context=");
3276                                 /* don't record NUL with untrusted strings */
3277                                 audit_log_n_untrustedstring(ab, s, len - 1);
3278                                 audit_log_end(ab);
3279                                 kfree(s);
3280                         }
3281                         goto out_unlock;
3282                 }
3283         }
3284         rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
3285         if (rc == -ESTALE) {
3286                 rcu_read_unlock();
3287                 context_destroy(&newcon);
3288                 goto retry;
3289         }
3290 out_unlock:
3291         rcu_read_unlock();
3292         context_destroy(&newcon);
3293         return rc;
3294 }
3295
3296 /**
3297  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
3298  * @state: SELinux state
3299  * @nlbl_sid: NetLabel SID
3300  * @nlbl_type: NetLabel labeling protocol type
3301  * @xfrm_sid: XFRM SID
3302  * @peer_sid: network peer sid
3303  *
3304  * Description:
3305  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
3306  * resolved into a single SID it is returned via @peer_sid and the function
3307  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
3308  * returns a negative value.  A table summarizing the behavior is below:
3309  *
3310  *                                 | function return |      @sid
3311  *   ------------------------------+-----------------+-----------------
3312  *   no peer labels                |        0        |    SECSID_NULL
3313  *   single peer label             |        0        |    <peer_label>
3314  *   multiple, consistent labels   |        0        |    <peer_label>
3315  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
3316  *
3317  */
3318 int security_net_peersid_resolve(struct selinux_state *state,
3319                                  u32 nlbl_sid, u32 nlbl_type,
3320                                  u32 xfrm_sid,
3321                                  u32 *peer_sid)
3322 {
3323         struct selinux_policy *policy;
3324         struct policydb *policydb;
3325         struct sidtab *sidtab;
3326         int rc;
3327         struct context *nlbl_ctx;
3328         struct context *xfrm_ctx;
3329
3330         *peer_sid = SECSID_NULL;
3331
3332         /* handle the common (which also happens to be the set of easy) cases
3333          * right away, these two if statements catch everything involving a
3334          * single or absent peer SID/label */
3335         if (xfrm_sid == SECSID_NULL) {
3336                 *peer_sid = nlbl_sid;
3337                 return 0;
3338         }
3339         /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
3340          * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
3341          * is present */
3342         if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
3343                 *peer_sid = xfrm_sid;
3344                 return 0;
3345         }
3346
3347         if (!selinux_initialized(state))
3348                 return 0;
3349
3350         rcu_read_lock();
3351         policy = rcu_dereference(state->policy);
3352         policydb = &policy->policydb;
3353         sidtab = policy->sidtab;
3354
3355         /*
3356          * We don't need to check initialized here since the only way both
3357          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
3358          * security server was initialized and state->initialized was true.
3359          */
3360         if (!policydb->mls_enabled) {
3361                 rc = 0;
3362                 goto out;
3363         }
3364
3365         rc = -EINVAL;
3366         nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
3367         if (!nlbl_ctx) {
3368                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3369                        __func__, nlbl_sid);
3370                 goto out;
3371         }
3372         rc = -EINVAL;
3373         xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
3374         if (!xfrm_ctx) {
3375                 pr_err("SELinux: %s:  unrecognized SID %d\n",
3376                        __func__, xfrm_sid);
3377                 goto out;
3378         }
3379         rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
3380         if (rc)
3381                 goto out;
3382
3383         /* at present NetLabel SIDs/labels really only carry MLS
3384          * information so if the MLS portion of the NetLabel SID
3385          * matches the MLS portion of the labeled XFRM SID/label
3386          * then pass along the XFRM SID as it is the most
3387          * expressive */
3388         *peer_sid = xfrm_sid;
3389 out:
3390         rcu_read_unlock();
3391         return rc;
3392 }
3393
3394 static int get_classes_callback(void *k, void *d, void *args)
3395 {
3396         struct class_datum *datum = d;
3397         char *name = k, **classes = args;
3398         int value = datum->value - 1;
3399
3400         classes[value] = kstrdup(name, GFP_ATOMIC);
3401         if (!classes[value])
3402                 return -ENOMEM;
3403
3404         return 0;
3405 }
3406
3407 int security_get_classes(struct selinux_policy *policy,
3408                          char ***classes, int *nclasses)
3409 {
3410         struct policydb *policydb;
3411         int rc;
3412
3413         policydb = &policy->policydb;
3414
3415         rc = -ENOMEM;
3416         *nclasses = policydb->p_classes.nprim;
3417         *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
3418         if (!*classes)
3419                 goto out;
3420
3421         rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
3422                          *classes);
3423         if (rc) {
3424                 int i;
3425                 for (i = 0; i < *nclasses; i++)
3426                         kfree((*classes)[i]);
3427                 kfree(*classes);
3428         }
3429
3430 out:
3431         return rc;
3432 }
3433
3434 static int get_permissions_callback(void *k, void *d, void *args)
3435 {
3436         struct perm_datum *datum = d;
3437         char *name = k, **perms = args;
3438         int value = datum->value - 1;
3439
3440         perms[value] = kstrdup(name, GFP_ATOMIC);
3441         if (!perms[value])
3442                 return -ENOMEM;
3443
3444         return 0;
3445 }
3446
3447 int security_get_permissions(struct selinux_policy *policy,
3448                              char *class, char ***perms, int *nperms)
3449 {
3450         struct policydb *policydb;
3451         int rc, i;
3452         struct class_datum *match;
3453
3454         policydb = &policy->policydb;
3455
3456         rc = -EINVAL;
3457         match = symtab_search(&policydb->p_classes, class);
3458         if (!match) {
3459                 pr_err("SELinux: %s:  unrecognized class %s\n",
3460                         __func__, class);
3461                 goto out;
3462         }
3463
3464         rc = -ENOMEM;
3465         *nperms = match->permissions.nprim;
3466         *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
3467         if (!*perms)
3468                 goto out;
3469
3470         if (match->comdatum) {
3471                 rc = hashtab_map(&match->comdatum->permissions.table,
3472                                  get_permissions_callback, *perms);
3473                 if (rc)
3474                         goto err;
3475         }
3476
3477         rc = hashtab_map(&match->permissions.table, get_permissions_callback,
3478                          *perms);
3479         if (rc)
3480                 goto err;
3481
3482 out:
3483         return rc;
3484
3485 err:
3486         for (i = 0; i < *nperms; i++)
3487                 kfree((*perms)[i]);
3488         kfree(*perms);
3489         return rc;
3490 }
3491
3492 int security_get_reject_unknown(struct selinux_state *state)
3493 {
3494         struct selinux_policy *policy;
3495         int value;
3496
3497         if (!selinux_initialized(state))
3498                 return 0;
3499
3500         rcu_read_lock();
3501         policy = rcu_dereference(state->policy);
3502         value = policy->policydb.reject_unknown;
3503         rcu_read_unlock();
3504         return value;
3505 }
3506
3507 int security_get_allow_unknown(struct selinux_state *state)
3508 {
3509         struct selinux_policy *policy;
3510         int value;
3511
3512         if (!selinux_initialized(state))
3513                 return 0;
3514
3515         rcu_read_lock();
3516         policy = rcu_dereference(state->policy);
3517         value = policy->policydb.allow_unknown;
3518         rcu_read_unlock();
3519         return value;
3520 }
3521
3522 /**
3523  * security_policycap_supported - Check for a specific policy capability
3524  * @state: SELinux state
3525  * @req_cap: capability
3526  *
3527  * Description:
3528  * This function queries the currently loaded policy to see if it supports the
3529  * capability specified by @req_cap.  Returns true (1) if the capability is
3530  * supported, false (0) if it isn't supported.
3531  *
3532  */
3533 int security_policycap_supported(struct selinux_state *state,
3534                                  unsigned int req_cap)
3535 {
3536         struct selinux_policy *policy;
3537         int rc;
3538
3539         if (!selinux_initialized(state))
3540                 return 0;
3541
3542         rcu_read_lock();
3543         policy = rcu_dereference(state->policy);
3544         rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
3545         rcu_read_unlock();
3546
3547         return rc;
3548 }
3549
3550 struct selinux_audit_rule {
3551         u32 au_seqno;
3552         struct context au_ctxt;
3553 };
3554
3555 void selinux_audit_rule_free(void *vrule)
3556 {
3557         struct selinux_audit_rule *rule = vrule;
3558
3559         if (rule) {
3560                 context_destroy(&rule->au_ctxt);
3561                 kfree(rule);
3562         }
3563 }
3564
3565 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3566 {
3567         struct selinux_state *state = &selinux_state;
3568         struct selinux_policy *policy;
3569         struct policydb *policydb;
3570         struct selinux_audit_rule *tmprule;
3571         struct role_datum *roledatum;
3572         struct type_datum *typedatum;
3573         struct user_datum *userdatum;
3574         struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
3575         int rc = 0;
3576
3577         *rule = NULL;
3578
3579         if (!selinux_initialized(state))
3580                 return -EOPNOTSUPP;
3581
3582         switch (field) {
3583         case AUDIT_SUBJ_USER:
3584         case AUDIT_SUBJ_ROLE:
3585         case AUDIT_SUBJ_TYPE:
3586         case AUDIT_OBJ_USER:
3587         case AUDIT_OBJ_ROLE:
3588         case AUDIT_OBJ_TYPE:
3589                 /* only 'equals' and 'not equals' fit user, role, and type */
3590                 if (op != Audit_equal && op != Audit_not_equal)
3591                         return -EINVAL;
3592                 break;
3593         case AUDIT_SUBJ_SEN:
3594         case AUDIT_SUBJ_CLR:
3595         case AUDIT_OBJ_LEV_LOW:
3596         case AUDIT_OBJ_LEV_HIGH:
3597                 /* we do not allow a range, indicated by the presence of '-' */
3598                 if (strchr(rulestr, '-'))
3599                         return -EINVAL;
3600                 break;
3601         default:
3602                 /* only the above fields are valid */
3603                 return -EINVAL;
3604         }
3605
3606         tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
3607         if (!tmprule)
3608                 return -ENOMEM;
3609
3610         context_init(&tmprule->au_ctxt);
3611
3612         rcu_read_lock();
3613         policy = rcu_dereference(state->policy);
3614         policydb = &policy->policydb;
3615
3616         tmprule->au_seqno = policy->latest_granting;
3617
3618         switch (field) {
3619         case AUDIT_SUBJ_USER:
3620         case AUDIT_OBJ_USER:
3621                 rc = -EINVAL;
3622                 userdatum = symtab_search(&policydb->p_users, rulestr);
3623                 if (!userdatum)
3624                         goto out;
3625                 tmprule->au_ctxt.user = userdatum->value;
3626                 break;
3627         case AUDIT_SUBJ_ROLE:
3628         case AUDIT_OBJ_ROLE:
3629                 rc = -EINVAL;
3630                 roledatum = symtab_search(&policydb->p_roles, rulestr);
3631                 if (!roledatum)
3632                         goto out;
3633                 tmprule->au_ctxt.role = roledatum->value;
3634                 break;
3635         case AUDIT_SUBJ_TYPE:
3636         case AUDIT_OBJ_TYPE:
3637                 rc = -EINVAL;
3638                 typedatum = symtab_search(&policydb->p_types, rulestr);
3639                 if (!typedatum)
3640                         goto out;
3641                 tmprule->au_ctxt.type = typedatum->value;
3642                 break;
3643         case AUDIT_SUBJ_SEN:
3644         case AUDIT_SUBJ_CLR:
3645         case AUDIT_OBJ_LEV_LOW:
3646         case AUDIT_OBJ_LEV_HIGH:
3647                 rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
3648                                      GFP_ATOMIC);
3649                 if (rc)
3650                         goto out;
3651                 break;
3652         }
3653         rc = 0;
3654 out:
3655         rcu_read_unlock();
3656
3657         if (rc) {
3658                 selinux_audit_rule_free(tmprule);
3659                 tmprule = NULL;
3660         }
3661
3662         *rule = tmprule;
3663
3664         return rc;
3665 }
3666
3667 /* Check to see if the rule contains any selinux fields */
3668 int selinux_audit_rule_known(struct audit_krule *rule)
3669 {
3670         int i;
3671
3672         for (i = 0; i < rule->field_count; i++) {
3673                 struct audit_field *f = &rule->fields[i];
3674                 switch (f->type) {
3675                 case AUDIT_SUBJ_USER:
3676                 case AUDIT_SUBJ_ROLE:
3677                 case AUDIT_SUBJ_TYPE:
3678                 case AUDIT_SUBJ_SEN:
3679                 case AUDIT_SUBJ_CLR:
3680                 case AUDIT_OBJ_USER:
3681                 case AUDIT_OBJ_ROLE:
3682                 case AUDIT_OBJ_TYPE:
3683                 case AUDIT_OBJ_LEV_LOW:
3684                 case AUDIT_OBJ_LEV_HIGH:
3685                         return 1;
3686                 }
3687         }
3688
3689         return 0;
3690 }
3691
3692 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
3693 {
3694         struct selinux_state *state = &selinux_state;
3695         struct selinux_policy *policy;
3696         struct context *ctxt;
3697         struct mls_level *level;
3698         struct selinux_audit_rule *rule = vrule;
3699         int match = 0;
3700
3701         if (unlikely(!rule)) {
3702                 WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
3703                 return -ENOENT;
3704         }
3705
3706         if (!selinux_initialized(state))
3707                 return 0;
3708
3709         rcu_read_lock();
3710
3711         policy = rcu_dereference(state->policy);
3712
3713         if (rule->au_seqno < policy->latest_granting) {
3714                 match = -ESTALE;
3715                 goto out;
3716         }
3717
3718         ctxt = sidtab_search(policy->sidtab, sid);
3719         if (unlikely(!ctxt)) {
3720                 WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
3721                           sid);
3722                 match = -ENOENT;
3723                 goto out;
3724         }
3725
3726         /* a field/op pair that is not caught here will simply fall through
3727            without a match */
3728         switch (field) {
3729         case AUDIT_SUBJ_USER:
3730         case AUDIT_OBJ_USER:
3731                 switch (op) {
3732                 case Audit_equal:
3733                         match = (ctxt->user == rule->au_ctxt.user);
3734                         break;
3735                 case Audit_not_equal:
3736                         match = (ctxt->user != rule->au_ctxt.user);
3737                         break;
3738                 }
3739                 break;
3740         case AUDIT_SUBJ_ROLE:
3741         case AUDIT_OBJ_ROLE:
3742                 switch (op) {
3743                 case Audit_equal:
3744                         match = (ctxt->role == rule->au_ctxt.role);
3745                         break;
3746                 case Audit_not_equal:
3747                         match = (ctxt->role != rule->au_ctxt.role);
3748                         break;
3749                 }
3750                 break;
3751         case AUDIT_SUBJ_TYPE:
3752         case AUDIT_OBJ_TYPE:
3753                 switch (op) {
3754                 case Audit_equal:
3755                         match = (ctxt->type == rule->au_ctxt.type);
3756                         break;
3757                 case Audit_not_equal:
3758                         match = (ctxt->type != rule->au_ctxt.type);
3759                         break;
3760                 }
3761                 break;
3762         case AUDIT_SUBJ_SEN:
3763         case AUDIT_SUBJ_CLR:
3764         case AUDIT_OBJ_LEV_LOW:
3765         case AUDIT_OBJ_LEV_HIGH:
3766                 level = ((field == AUDIT_SUBJ_SEN ||
3767                           field == AUDIT_OBJ_LEV_LOW) ?
3768                          &ctxt->range.level[0] : &ctxt->range.level[1]);
3769                 switch (op) {
3770                 case Audit_equal:
3771                         match = mls_level_eq(&rule->au_ctxt.range.level[0],
3772                                              level);
3773                         break;
3774                 case Audit_not_equal:
3775                         match = !mls_level_eq(&rule->au_ctxt.range.level[0],
3776                                               level);
3777                         break;
3778                 case Audit_lt:
3779                         match = (mls_level_dom(&rule->au_ctxt.range.level[0],
3780                                                level) &&
3781                                  !mls_level_eq(&rule->au_ctxt.range.level[0],
3782                                                level));
3783                         break;
3784                 case Audit_le:
3785                         match = mls_level_dom(&rule->au_ctxt.range.level[0],
3786                                               level);
3787                         break;
3788                 case Audit_gt:
3789                         match = (mls_level_dom(level,
3790                                               &rule->au_ctxt.range.level[0]) &&
3791                                  !mls_level_eq(level,
3792                                                &rule->au_ctxt.range.level[0]));
3793                         break;
3794                 case Audit_ge:
3795                         match = mls_level_dom(level,
3796                                               &rule->au_ctxt.range.level[0]);
3797                         break;
3798                 }
3799         }
3800
3801 out:
3802         rcu_read_unlock();
3803         return match;
3804 }
3805
3806 static int aurule_avc_callback(u32 event)
3807 {
3808         if (event == AVC_CALLBACK_RESET)
3809                 return audit_update_lsm_rules();
3810         return 0;
3811 }
3812
3813 static int __init aurule_init(void)
3814 {
3815         int err;
3816
3817         err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
3818         if (err)
3819                 panic("avc_add_callback() failed, error %d\n", err);
3820
3821         return err;
3822 }
3823 __initcall(aurule_init);
3824
3825 #ifdef CONFIG_NETLABEL
3826 /**
3827  * security_netlbl_cache_add - Add an entry to the NetLabel cache
3828  * @secattr: the NetLabel packet security attributes
3829  * @sid: the SELinux SID
3830  *
3831  * Description:
3832  * Attempt to cache the context in @ctx, which was derived from the packet in
3833  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
3834  * already been initialized.
3835  *
3836  */
3837 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
3838                                       u32 sid)
3839 {
3840         u32 *sid_cache;
3841
3842         sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
3843         if (sid_cache == NULL)
3844                 return;
3845         secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
3846         if (secattr->cache == NULL) {
3847                 kfree(sid_cache);
3848                 return;
3849         }
3850
3851         *sid_cache = sid;
3852         secattr->cache->free = kfree;
3853         secattr->cache->data = sid_cache;
3854         secattr->flags |= NETLBL_SECATTR_CACHE;
3855 }
3856
3857 /**
3858  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
3859  * @state: SELinux state
3860  * @secattr: the NetLabel packet security attributes
3861  * @sid: the SELinux SID
3862  *
3863  * Description:
3864  * Convert the given NetLabel security attributes in @secattr into a
3865  * SELinux SID.  If the @secattr field does not contain a full SELinux
3866  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
3867  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
3868  * allow the @secattr to be used by NetLabel to cache the secattr to SID
3869  * conversion for future lookups.  Returns zero on success, negative values on
3870  * failure.
3871  *
3872  */
3873 int security_netlbl_secattr_to_sid(struct selinux_state *state,
3874                                    struct netlbl_lsm_secattr *secattr,
3875                                    u32 *sid)
3876 {
3877         struct selinux_policy *policy;
3878         struct policydb *policydb;
3879         struct sidtab *sidtab;
3880         int rc;
3881         struct context *ctx;
3882         struct context ctx_new;
3883
3884         if (!selinux_initialized(state)) {
3885                 *sid = SECSID_NULL;
3886                 return 0;
3887         }
3888
3889 retry:
3890         rc = 0;
3891         rcu_read_lock();
3892         policy = rcu_dereference(state->policy);
3893         policydb = &policy->policydb;
3894         sidtab = policy->sidtab;
3895
3896         if (secattr->flags & NETLBL_SECATTR_CACHE)
3897                 *sid = *(u32 *)secattr->cache->data;
3898         else if (secattr->flags & NETLBL_SECATTR_SECID)
3899                 *sid = secattr->attr.secid;
3900         else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
3901                 rc = -EIDRM;
3902                 ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
3903                 if (ctx == NULL)
3904                         goto out;
3905
3906                 context_init(&ctx_new);
3907                 ctx_new.user = ctx->user;
3908                 ctx_new.role = ctx->role;
3909                 ctx_new.type = ctx->type;
3910                 mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
3911                 if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
3912                         rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
3913                         if (rc)
3914                                 goto out;
3915                 }
3916                 rc = -EIDRM;
3917                 if (!mls_context_isvalid(policydb, &ctx_new)) {
3918                         ebitmap_destroy(&ctx_new.range.level[0].cat);
3919                         goto out;
3920                 }
3921
3922                 rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
3923                 ebitmap_destroy(&ctx_new.range.level[0].cat);
3924                 if (rc == -ESTALE) {
3925                         rcu_read_unlock();
3926                         goto retry;
3927                 }
3928                 if (rc)
3929                         goto out;
3930
3931                 security_netlbl_cache_add(secattr, *sid);
3932         } else
3933                 *sid = SECSID_NULL;
3934
3935 out:
3936         rcu_read_unlock();
3937         return rc;
3938 }
3939
3940 /**
3941  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
3942  * @state: SELinux state
3943  * @sid: the SELinux SID
3944  * @secattr: the NetLabel packet security attributes
3945  *
3946  * Description:
3947  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
3948  * Returns zero on success, negative values on failure.
3949  *
3950  */
3951 int security_netlbl_sid_to_secattr(struct selinux_state *state,
3952                                    u32 sid, struct netlbl_lsm_secattr *secattr)
3953 {
3954         struct selinux_policy *policy;
3955         struct policydb *policydb;
3956         int rc;
3957         struct context *ctx;
3958
3959         if (!selinux_initialized(state))
3960                 return 0;
3961
3962         rcu_read_lock();
3963         policy = rcu_dereference(state->policy);
3964         policydb = &policy->policydb;
3965
3966         rc = -ENOENT;
3967         ctx = sidtab_search(policy->sidtab, sid);
3968         if (ctx == NULL)
3969                 goto out;
3970
3971         rc = -ENOMEM;
3972         secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
3973                                   GFP_ATOMIC);
3974         if (secattr->domain == NULL)
3975                 goto out;
3976
3977         secattr->attr.secid = sid;
3978         secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
3979         mls_export_netlbl_lvl(policydb, ctx, secattr);
3980         rc = mls_export_netlbl_cat(policydb, ctx, secattr);
3981 out:
3982         rcu_read_unlock();
3983         return rc;
3984 }
3985 #endif /* CONFIG_NETLABEL */
3986
3987 /**
3988  * __security_read_policy - read the policy.
3989  * @policy: SELinux policy
3990  * @data: binary policy data
3991  * @len: length of data in bytes
3992  *
3993  */
3994 static int __security_read_policy(struct selinux_policy *policy,
3995                                   void *data, size_t *len)
3996 {
3997         int rc;
3998         struct policy_file fp;
3999
4000         fp.data = data;
4001         fp.len = *len;
4002
4003         rc = policydb_write(&policy->policydb, &fp);
4004         if (rc)
4005                 return rc;
4006
4007         *len = (unsigned long)fp.data - (unsigned long)data;
4008         return 0;
4009 }
4010
4011 /**
4012  * security_read_policy - read the policy.
4013  * @state: selinux_state
4014  * @data: binary policy data
4015  * @len: length of data in bytes
4016  *
4017  */
4018 int security_read_policy(struct selinux_state *state,
4019                          void **data, size_t *len)
4020 {
4021         struct selinux_policy *policy;
4022
4023         policy = rcu_dereference_protected(
4024                         state->policy, lockdep_is_held(&state->policy_mutex));
4025         if (!policy)
4026                 return -EINVAL;
4027
4028         *len = policy->policydb.len;
4029         *data = vmalloc_user(*len);
4030         if (!*data)
4031                 return -ENOMEM;
4032
4033         return __security_read_policy(policy, *data, len);
4034 }
4035
4036 /**
4037  * security_read_state_kernel - read the policy.
4038  * @state: selinux_state
4039  * @data: binary policy data
4040  * @len: length of data in bytes
4041  *
4042  * Allocates kernel memory for reading SELinux policy.
4043  * This function is for internal use only and should not
4044  * be used for returning data to user space.
4045  *
4046  * This function must be called with policy_mutex held.
4047  */
4048 int security_read_state_kernel(struct selinux_state *state,
4049                                void **data, size_t *len)
4050 {
4051         struct selinux_policy *policy;
4052
4053         policy = rcu_dereference_protected(
4054                         state->policy, lockdep_is_held(&state->policy_mutex));
4055         if (!policy)
4056                 return -EINVAL;
4057
4058         *len = policy->policydb.len;
4059         *data = vmalloc(*len);
4060         if (!*data)
4061                 return -ENOMEM;
4062
4063         return __security_read_policy(policy, *data, len);
4064 }