security/selinux/selinuxfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
   3  *
   4  *      Added conditional policy language extensions
   5  *
   6  *  Updated: Hewlett-Packard <paul@paul-moore.com>
   7  *
   8  *      Added support for the policy capability bitmap
   9  *
  10  * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
  11  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  12  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/slab.h>
  18 #include <linux/vmalloc.h>
  19 #include <linux/fs.h>
  20 #include <linux/fs_context.h>
  21 #include <linux/mount.h>
  22 #include <linux/mutex.h>
  23 #include <linux/init.h>
  24 #include <linux/string.h>
  25 #include <linux/security.h>
  26 #include <linux/major.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/percpu.h>
  29 #include <linux/audit.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/kobject.h>
  32 #include <linux/ctype.h>
  33
  34 /* selinuxfs pseudo filesystem for exporting the security policy API.
  35    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  36
  37 #include "flask.h"
  38 #include "avc.h"
  39 #include "avc_ss.h"
  40 #include "security.h"
  41 #include "objsec.h"
  42 #include "conditional.h"
  43
  44 enum sel_inos {
  45         SEL_ROOT_INO = 2,
  46         SEL_LOAD,       /* load policy */
  47         SEL_ENFORCE,    /* get or set enforcing status */
  48         SEL_CONTEXT,    /* validate context */
  49         SEL_ACCESS,     /* compute access decision */
  50         SEL_CREATE,     /* compute create labeling decision */
  51         SEL_RELABEL,    /* compute relabeling decision */
  52         SEL_USER,       /* compute reachable user contexts */
  53         SEL_POLICYVERS, /* return policy version for this kernel */
  54         SEL_COMMIT_BOOLS, /* commit new boolean values */
  55         SEL_MLS,        /* return if MLS policy is enabled */
  56         SEL_DISABLE,    /* disable SELinux until next reboot */
  57         SEL_MEMBER,     /* compute polyinstantiation membership decision */
  58         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
  59         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
  60         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
  61         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
  62         SEL_STATUS,     /* export current status using mmap() */
  63         SEL_POLICY,     /* allow userspace to read the in kernel policy */
  64         SEL_VALIDATE_TRANS, /* compute validatetrans decision */
  65         SEL_INO_NEXT,   /* The next inode number to use */
  66 };
  67
  68 struct selinux_fs_info {
  69         struct dentry *bool_dir;
  70         unsigned int bool_num;
  71         char **bool_pending_names;
  72         unsigned int *bool_pending_values;
  73         struct dentry *class_dir;
  74         unsigned long last_class_ino;
  75         bool policy_opened;
  76         struct dentry *policycap_dir;
  77         struct mutex mutex;
  78         unsigned long last_ino;
  79         struct selinux_state *state;
  80         struct super_block *sb;
  81 };
  82
  83 static int selinux_fs_info_create(struct super_block *sb)
  84 {
  85         struct selinux_fs_info *fsi;
  86
  87         fsi = kzalloc(sizeof(*fsi), GFP_KERNEL);
  88         if (!fsi)
  89                 return -ENOMEM;
  90
  91         mutex_init(&fsi->mutex);
  92         fsi->last_ino = SEL_INO_NEXT - 1;
  93         fsi->state = &selinux_state;
  94         fsi->sb = sb;
  95         sb->s_fs_info = fsi;
  96         return 0;
  97 }
  98
  99 static void selinux_fs_info_free(struct super_block *sb)
 100 {
 101         struct selinux_fs_info *fsi = sb->s_fs_info;
 102         int i;
 103
 104         if (fsi) {
 105                 for (i = 0; i < fsi->bool_num; i++)
 106                         kfree(fsi->bool_pending_names[i]);
 107                 kfree(fsi->bool_pending_names);
 108                 kfree(fsi->bool_pending_values);
 109         }
 110         kfree(sb->s_fs_info);
 111         sb->s_fs_info = NULL;
 112 }
 113
 114 #define SEL_INITCON_INO_OFFSET          0x01000000
 115 #define SEL_BOOL_INO_OFFSET             0x02000000
 116 #define SEL_CLASS_INO_OFFSET            0x04000000
 117 #define SEL_POLICYCAP_INO_OFFSET        0x08000000
 118 #define SEL_INO_MASK                    0x00ffffff
 119
 120 #define TMPBUFLEN       12
 121 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 122                                 size_t count, loff_t *ppos)
 123 {
 124         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 125         char tmpbuf[TMPBUFLEN];
 126         ssize_t length;
 127
 128         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 129                            enforcing_enabled(fsi->state));
 130         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 131 }
 132
 133 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 134 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 135                                  size_t count, loff_t *ppos)
 136
 137 {
 138         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 139         struct selinux_state *state = fsi->state;
 140         char *page = NULL;
 141         ssize_t length;
 142         int old_value, new_value;
 143
 144         if (count >= PAGE_SIZE)
 145                 return -ENOMEM;
 146
 147         /* No partial writes. */
 148         if (*ppos != 0)
 149                 return -EINVAL;
 150
 151         page = memdup_user_nul(buf, count);
 152         if (IS_ERR(page))
 153                 return PTR_ERR(page);
 154
 155         length = -EINVAL;
 156         if (sscanf(page, "%d", &new_value) != 1)
 157                 goto out;
 158
 159         new_value = !!new_value;
 160
 161         old_value = enforcing_enabled(state);
 162         if (new_value != old_value) {
 163                 length = avc_has_perm(&selinux_state,
 164                                       current_sid(), SECINITSID_SECURITY,
 165                                       SECCLASS_SECURITY, SECURITY__SETENFORCE,
 166                                       NULL);
 167                 if (length)
 168                         goto out;
 169                 audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
 170                         "enforcing=%d old_enforcing=%d auid=%u ses=%u"
 171                         " enabled=%d old-enabled=%d lsm=selinux res=1",
 172                         new_value, old_value,
 173                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
 174                         audit_get_sessionid(current),
 175                         selinux_enabled, selinux_enabled);
 176                 enforcing_set(state, new_value);
 177                 if (new_value)
 178                         avc_ss_reset(state->avc, 0);
 179                 selnl_notify_setenforce(new_value);
 180                 selinux_status_update_setenforce(state, new_value);
 181                 if (!new_value)
 182                         call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
 183         }
 184         length = count;
 185 out:
 186         kfree(page);
 187         return length;
 188 }
 189 #else
 190 #define sel_write_enforce NULL
 191 #endif
 192
 193 static const struct file_operations sel_enforce_ops = {
 194         .read           = sel_read_enforce,
 195         .write          = sel_write_enforce,
 196         .llseek         = generic_file_llseek,
 197 };
 198
 199 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 200                                         size_t count, loff_t *ppos)
 201 {
 202         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 203         struct selinux_state *state = fsi->state;
 204         char tmpbuf[TMPBUFLEN];
 205         ssize_t length;
 206         ino_t ino = file_inode(filp)->i_ino;
 207         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 208                 security_get_reject_unknown(state) :
 209                 !security_get_allow_unknown(state);
 210
 211         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 212         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 213 }
 214
 215 static const struct file_operations sel_handle_unknown_ops = {
 216         .read           = sel_read_handle_unknown,
 217         .llseek         = generic_file_llseek,
 218 };
 219
 220 static int sel_open_handle_status(struct inode *inode, struct file *filp)
 221 {
 222         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 223         struct page    *status = selinux_kernel_status_page(fsi->state);
 224
 225         if (!status)
 226                 return -ENOMEM;
 227
 228         filp->private_data = status;
 229
 230         return 0;
 231 }
 232
 233 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 234                                       size_t count, loff_t *ppos)
 235 {
 236         struct page    *status = filp->private_data;
 237
 238         BUG_ON(!status);
 239
 240         return simple_read_from_buffer(buf, count, ppos,
 241                                        page_address(status),
 242                                        sizeof(struct selinux_kernel_status));
 243 }
 244
 245 static int sel_mmap_handle_status(struct file *filp,
 246                                   struct vm_area_struct *vma)
 247 {
 248         struct page    *status = filp->private_data;
 249         unsigned long   size = vma->vm_end - vma->vm_start;
 250
 251         BUG_ON(!status);
 252
 253         /* only allows one page from the head */
 254         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 255                 return -EIO;
 256         /* disallow writable mapping */
 257         if (vma->vm_flags & VM_WRITE)
 258                 return -EPERM;
 259         /* disallow mprotect() turns it into writable */
 260         vma->vm_flags &= ~VM_MAYWRITE;
 261
 262         return remap_pfn_range(vma, vma->vm_start,
 263                                page_to_pfn(status),
 264                                size, vma->vm_page_prot);
 265 }
 266
 267 static const struct file_operations sel_handle_status_ops = {
 268         .open           = sel_open_handle_status,
 269         .read           = sel_read_handle_status,
 270         .mmap           = sel_mmap_handle_status,
 271         .llseek         = generic_file_llseek,
 272 };
 273
 274 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 275 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 276                                  size_t count, loff_t *ppos)
 277
 278 {
 279         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 280         char *page;
 281         ssize_t length;
 282         int new_value;
 283         int enforcing;
 284
 285         if (count >= PAGE_SIZE)
 286                 return -ENOMEM;
 287
 288         /* No partial writes. */
 289         if (*ppos != 0)
 290                 return -EINVAL;
 291
 292         page = memdup_user_nul(buf, count);
 293         if (IS_ERR(page))
 294                 return PTR_ERR(page);
 295
 296         length = -EINVAL;
 297         if (sscanf(page, "%d", &new_value) != 1)
 298                 goto out;
 299
 300         if (new_value) {
 301                 enforcing = enforcing_enabled(fsi->state);
 302                 length = selinux_disable(fsi->state);
 303                 if (length)
 304                         goto out;
 305                 audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
 306                         "enforcing=%d old_enforcing=%d auid=%u ses=%u"
 307                         " enabled=%d old-enabled=%d lsm=selinux res=1",
 308                         enforcing, enforcing,
 309                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
 310                         audit_get_sessionid(current), 0, 1);
 311         }
 312
 313         length = count;
 314 out:
 315         kfree(page);
 316         return length;
 317 }
 318 #else
 319 #define sel_write_disable NULL
 320 #endif
 321
 322 static const struct file_operations sel_disable_ops = {
 323         .write          = sel_write_disable,
 324         .llseek         = generic_file_llseek,
 325 };
 326
 327 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 328                                    size_t count, loff_t *ppos)
 329 {
 330         char tmpbuf[TMPBUFLEN];
 331         ssize_t length;
 332
 333         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 334         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 335 }
 336
 337 static const struct file_operations sel_policyvers_ops = {
 338         .read           = sel_read_policyvers,
 339         .llseek         = generic_file_llseek,
 340 };
 341
 342 /* declaration for sel_write_load */
 343 static int sel_make_bools(struct selinux_fs_info *fsi);
 344 static int sel_make_classes(struct selinux_fs_info *fsi);
 345 static int sel_make_policycap(struct selinux_fs_info *fsi);
 346
 347 /* declaration for sel_make_class_dirs */
 348 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
 349                         unsigned long *ino);
 350
 351 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 352                                 size_t count, loff_t *ppos)
 353 {
 354         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 355         char tmpbuf[TMPBUFLEN];
 356         ssize_t length;
 357
 358         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 359                            security_mls_enabled(fsi->state));
 360         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 361 }
 362
 363 static const struct file_operations sel_mls_ops = {
 364         .read           = sel_read_mls,
 365         .llseek         = generic_file_llseek,
 366 };
 367
 368 struct policy_load_memory {
 369         size_t len;
 370         void *data;
 371 };
 372
 373 static int sel_open_policy(struct inode *inode, struct file *filp)
 374 {
 375         struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
 376         struct selinux_state *state = fsi->state;
 377         struct policy_load_memory *plm = NULL;
 378         int rc;
 379
 380         BUG_ON(filp->private_data);
 381
 382         mutex_lock(&fsi->mutex);
 383
 384         rc = avc_has_perm(&selinux_state,
 385                           current_sid(), SECINITSID_SECURITY,
 386                           SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
 387         if (rc)
 388                 goto err;
 389
 390         rc = -EBUSY;
 391         if (fsi->policy_opened)
 392                 goto err;
 393
 394         rc = -ENOMEM;
 395         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 396         if (!plm)
 397                 goto err;
 398
 399         if (i_size_read(inode) != security_policydb_len(state)) {
 400                 inode_lock(inode);
 401                 i_size_write(inode, security_policydb_len(state));
 402                 inode_unlock(inode);
 403         }
 404
 405         rc = security_read_policy(state, &plm->data, &plm->len);
 406         if (rc)
 407                 goto err;
 408
 409         fsi->policy_opened = 1;
 410
 411         filp->private_data = plm;
 412
 413         mutex_unlock(&fsi->mutex);
 414
 415         return 0;
 416 err:
 417         mutex_unlock(&fsi->mutex);
 418
 419         if (plm)
 420                 vfree(plm->data);
 421         kfree(plm);
 422         return rc;
 423 }
 424
 425 static int sel_release_policy(struct inode *inode, struct file *filp)
 426 {
 427         struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
 428         struct policy_load_memory *plm = filp->private_data;
 429
 430         BUG_ON(!plm);
 431
 432         fsi->policy_opened = 0;
 433
 434         vfree(plm->data);
 435         kfree(plm);
 436
 437         return 0;
 438 }
 439
 440 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 441                                size_t count, loff_t *ppos)
 442 {
 443         struct policy_load_memory *plm = filp->private_data;
 444         int ret;
 445
 446         ret = avc_has_perm(&selinux_state,
 447                            current_sid(), SECINITSID_SECURITY,
 448                           SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
 449         if (ret)
 450                 return ret;
 451
 452         return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 453 }
 454
 455 static vm_fault_t sel_mmap_policy_fault(struct vm_fault *vmf)
 456 {
 457         struct policy_load_memory *plm = vmf->vma->vm_file->private_data;
 458         unsigned long offset;
 459         struct page *page;
 460
 461         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 462                 return VM_FAULT_SIGBUS;
 463
 464         offset = vmf->pgoff << PAGE_SHIFT;
 465         if (offset >= roundup(plm->len, PAGE_SIZE))
 466                 return VM_FAULT_SIGBUS;
 467
 468         page = vmalloc_to_page(plm->data + offset);
 469         get_page(page);
 470
 471         vmf->page = page;
 472
 473         return 0;
 474 }
 475
 476 static const struct vm_operations_struct sel_mmap_policy_ops = {
 477         .fault = sel_mmap_policy_fault,
 478         .page_mkwrite = sel_mmap_policy_fault,
 479 };
 480
 481 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 482 {
 483         if (vma->vm_flags & VM_SHARED) {
 484                 /* do not allow mprotect to make mapping writable */
 485                 vma->vm_flags &= ~VM_MAYWRITE;
 486
 487                 if (vma->vm_flags & VM_WRITE)
 488                         return -EACCES;
 489         }
 490
 491         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 492         vma->vm_ops = &sel_mmap_policy_ops;
 493
 494         return 0;
 495 }
 496
 497 static const struct file_operations sel_policy_ops = {
 498         .open           = sel_open_policy,
 499         .read           = sel_read_policy,
 500         .mmap           = sel_mmap_policy,
 501         .release        = sel_release_policy,
 502         .llseek         = generic_file_llseek,
 503 };
 504
 505 static int sel_make_policy_nodes(struct selinux_fs_info *fsi)
 506 {
 507         int ret;
 508
 509         ret = sel_make_bools(fsi);
 510         if (ret) {
 511                 pr_err("SELinux: failed to load policy booleans\n");
 512                 return ret;
 513         }
 514
 515         ret = sel_make_classes(fsi);
 516         if (ret) {
 517                 pr_err("SELinux: failed to load policy classes\n");
 518                 return ret;
 519         }
 520
 521         ret = sel_make_policycap(fsi);
 522         if (ret) {
 523                 pr_err("SELinux: failed to load policy capabilities\n");
 524                 return ret;
 525         }
 526
 527         return 0;
 528 }
 529
 530 static ssize_t sel_write_load(struct file *file, const char __user *buf,
 531                               size_t count, loff_t *ppos)
 532
 533 {
 534         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 535         ssize_t length;
 536         void *data = NULL;
 537
 538         mutex_lock(&fsi->mutex);
 539
 540         length = avc_has_perm(&selinux_state,
 541                               current_sid(), SECINITSID_SECURITY,
 542                               SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL);
 543         if (length)
 544                 goto out;
 545
 546         /* No partial writes. */
 547         length = -EINVAL;
 548         if (*ppos != 0)
 549                 goto out;
 550
 551         length = -ENOMEM;
 552         data = vmalloc(count);
 553         if (!data)
 554                 goto out;
 555
 556         length = -EFAULT;
 557         if (copy_from_user(data, buf, count) != 0)
 558                 goto out;
 559
 560         length = security_load_policy(fsi->state, data, count);
 561         if (length) {
 562                 pr_warn_ratelimited("SELinux: failed to load policy\n");
 563                 goto out;
 564         }
 565
 566         length = sel_make_policy_nodes(fsi);
 567         if (length)
 568                 goto out1;
 569
 570         length = count;
 571
 572 out1:
 573         audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 574                 "auid=%u ses=%u lsm=selinux res=1",
 575                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
 576                 audit_get_sessionid(current));
 577 out:
 578         mutex_unlock(&fsi->mutex);
 579         vfree(data);
 580         return length;
 581 }
 582
 583 static const struct file_operations sel_load_ops = {
 584         .write          = sel_write_load,
 585         .llseek         = generic_file_llseek,
 586 };
 587
 588 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 589 {
 590         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 591         struct selinux_state *state = fsi->state;
 592         char *canon = NULL;
 593         u32 sid, len;
 594         ssize_t length;
 595
 596         length = avc_has_perm(&selinux_state,
 597                               current_sid(), SECINITSID_SECURITY,
 598                               SECCLASS_SECURITY, SECURITY__CHECK_CONTEXT, NULL);
 599         if (length)
 600                 goto out;
 601
 602         length = security_context_to_sid(state, buf, size, &sid, GFP_KERNEL);
 603         if (length)
 604                 goto out;
 605
 606         length = security_sid_to_context(state, sid, &canon, &len);
 607         if (length)
 608                 goto out;
 609
 610         length = -ERANGE;
 611         if (len > SIMPLE_TRANSACTION_LIMIT) {
 612                 pr_err("SELinux: %s:  context size (%u) exceeds "
 613                         "payload max\n", __func__, len);
 614                 goto out;
 615         }
 616
 617         memcpy(buf, canon, len);
 618         length = len;
 619 out:
 620         kfree(canon);
 621         return length;
 622 }
 623
 624 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 625                                      size_t count, loff_t *ppos)
 626 {
 627         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 628         char tmpbuf[TMPBUFLEN];
 629         ssize_t length;
 630
 631         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", fsi->state->checkreqprot);
 632         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 633 }
 634
 635 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 636                                       size_t count, loff_t *ppos)
 637 {
 638         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 639         char *page;
 640         ssize_t length;
 641         unsigned int new_value;
 642
 643         length = avc_has_perm(&selinux_state,
 644                               current_sid(), SECINITSID_SECURITY,
 645                               SECCLASS_SECURITY, SECURITY__SETCHECKREQPROT,
 646                               NULL);
 647         if (length)
 648                 return length;
 649
 650         if (count >= PAGE_SIZE)
 651                 return -ENOMEM;
 652
 653         /* No partial writes. */
 654         if (*ppos != 0)
 655                 return -EINVAL;
 656
 657         page = memdup_user_nul(buf, count);
 658         if (IS_ERR(page))
 659                 return PTR_ERR(page);
 660
 661         length = -EINVAL;
 662         if (sscanf(page, "%u", &new_value) != 1)
 663                 goto out;
 664
 665         fsi->state->checkreqprot = new_value ? 1 : 0;
 666         length = count;
 667 out:
 668         kfree(page);
 669         return length;
 670 }
 671 static const struct file_operations sel_checkreqprot_ops = {
 672         .read           = sel_read_checkreqprot,
 673         .write          = sel_write_checkreqprot,
 674         .llseek         = generic_file_llseek,
 675 };
 676
 677 static ssize_t sel_write_validatetrans(struct file *file,
 678                                         const char __user *buf,
 679                                         size_t count, loff_t *ppos)
 680 {
 681         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 682         struct selinux_state *state = fsi->state;
 683         char *oldcon = NULL, *newcon = NULL, *taskcon = NULL;
 684         char *req = NULL;
 685         u32 osid, nsid, tsid;
 686         u16 tclass;
 687         int rc;
 688
 689         rc = avc_has_perm(&selinux_state,
 690                           current_sid(), SECINITSID_SECURITY,
 691                           SECCLASS_SECURITY, SECURITY__VALIDATE_TRANS, NULL);
 692         if (rc)
 693                 goto out;
 694
 695         rc = -ENOMEM;
 696         if (count >= PAGE_SIZE)
 697                 goto out;
 698
 699         /* No partial writes. */
 700         rc = -EINVAL;
 701         if (*ppos != 0)
 702                 goto out;
 703
 704         req = memdup_user_nul(buf, count);
 705         if (IS_ERR(req)) {
 706                 rc = PTR_ERR(req);
 707                 req = NULL;
 708                 goto out;
 709         }
 710
 711         rc = -ENOMEM;
 712         oldcon = kzalloc(count + 1, GFP_KERNEL);
 713         if (!oldcon)
 714                 goto out;
 715
 716         newcon = kzalloc(count + 1, GFP_KERNEL);
 717         if (!newcon)
 718                 goto out;
 719
 720         taskcon = kzalloc(count + 1, GFP_KERNEL);
 721         if (!taskcon)
 722                 goto out;
 723
 724         rc = -EINVAL;
 725         if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4)
 726                 goto out;
 727
 728         rc = security_context_str_to_sid(state, oldcon, &osid, GFP_KERNEL);
 729         if (rc)
 730                 goto out;
 731
 732         rc = security_context_str_to_sid(state, newcon, &nsid, GFP_KERNEL);
 733         if (rc)
 734                 goto out;
 735
 736         rc = security_context_str_to_sid(state, taskcon, &tsid, GFP_KERNEL);
 737         if (rc)
 738                 goto out;
 739
 740         rc = security_validate_transition_user(state, osid, nsid, tsid, tclass);
 741         if (!rc)
 742                 rc = count;
 743 out:
 744         kfree(req);
 745         kfree(oldcon);
 746         kfree(newcon);
 747         kfree(taskcon);
 748         return rc;
 749 }
 750
 751 static const struct file_operations sel_transition_ops = {
 752         .write          = sel_write_validatetrans,
 753         .llseek         = generic_file_llseek,
 754 };
 755
 756 /*
 757  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 758  */
 759 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 760 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 761 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 762 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 763 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 764
 765 static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
 766         [SEL_ACCESS] = sel_write_access,
 767         [SEL_CREATE] = sel_write_create,
 768         [SEL_RELABEL] = sel_write_relabel,
 769         [SEL_USER] = sel_write_user,
 770         [SEL_MEMBER] = sel_write_member,
 771         [SEL_CONTEXT] = sel_write_context,
 772 };
 773
 774 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 775 {
 776         ino_t ino = file_inode(file)->i_ino;
 777         char *data;
 778         ssize_t rv;
 779
 780         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 781                 return -EINVAL;
 782
 783         data = simple_transaction_get(file, buf, size);
 784         if (IS_ERR(data))
 785                 return PTR_ERR(data);
 786
 787         rv = write_op[ino](file, data, size);
 788         if (rv > 0) {
 789                 simple_transaction_set(file, rv);
 790                 rv = size;
 791         }
 792         return rv;
 793 }
 794
 795 static const struct file_operations transaction_ops = {
 796         .write          = selinux_transaction_write,
 797         .read           = simple_transaction_read,
 798         .release        = simple_transaction_release,
 799         .llseek         = generic_file_llseek,
 800 };
 801
 802 /*
 803  * payload - write methods
 804  * If the method has a response, the response should be put in buf,
 805  * and the length returned.  Otherwise return 0 or and -error.
 806  */
 807
 808 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 809 {
 810         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 811         struct selinux_state *state = fsi->state;
 812         char *scon = NULL, *tcon = NULL;
 813         u32 ssid, tsid;
 814         u16 tclass;
 815         struct av_decision avd;
 816         ssize_t length;
 817
 818         length = avc_has_perm(&selinux_state,
 819                               current_sid(), SECINITSID_SECURITY,
 820                               SECCLASS_SECURITY, SECURITY__COMPUTE_AV, NULL);
 821         if (length)
 822                 goto out;
 823
 824         length = -ENOMEM;
 825         scon = kzalloc(size + 1, GFP_KERNEL);
 826         if (!scon)
 827                 goto out;
 828
 829         length = -ENOMEM;
 830         tcon = kzalloc(size + 1, GFP_KERNEL);
 831         if (!tcon)
 832                 goto out;
 833
 834         length = -EINVAL;
 835         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 836                 goto out;
 837
 838         length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
 839         if (length)
 840                 goto out;
 841
 842         length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
 843         if (length)
 844                 goto out;
 845
 846         security_compute_av_user(state, ssid, tsid, tclass, &avd);
 847
 848         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 849                           "%x %x %x %x %u %x",
 850                           avd.allowed, 0xffffffff,
 851                           avd.auditallow, avd.auditdeny,
 852                           avd.seqno, avd.flags);
 853 out:
 854         kfree(tcon);
 855         kfree(scon);
 856         return length;
 857 }
 858
 859 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 860 {
 861         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 862         struct selinux_state *state = fsi->state;
 863         char *scon = NULL, *tcon = NULL;
 864         char *namebuf = NULL, *objname = NULL;
 865         u32 ssid, tsid, newsid;
 866         u16 tclass;
 867         ssize_t length;
 868         char *newcon = NULL;
 869         u32 len;
 870         int nargs;
 871
 872         length = avc_has_perm(&selinux_state,
 873                               current_sid(), SECINITSID_SECURITY,
 874                               SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE,
 875                               NULL);
 876         if (length)
 877                 goto out;
 878
 879         length = -ENOMEM;
 880         scon = kzalloc(size + 1, GFP_KERNEL);
 881         if (!scon)
 882                 goto out;
 883
 884         length = -ENOMEM;
 885         tcon = kzalloc(size + 1, GFP_KERNEL);
 886         if (!tcon)
 887                 goto out;
 888
 889         length = -ENOMEM;
 890         namebuf = kzalloc(size + 1, GFP_KERNEL);
 891         if (!namebuf)
 892                 goto out;
 893
 894         length = -EINVAL;
 895         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 896         if (nargs < 3 || nargs > 4)
 897                 goto out;
 898         if (nargs == 4) {
 899                 /*
 900                  * If and when the name of new object to be queried contains
 901                  * either whitespace or multibyte characters, they shall be
 902                  * encoded based on the percentage-encoding rule.
 903                  * If not encoded, the sscanf logic picks up only left-half
 904                  * of the supplied name; splitted by a whitespace unexpectedly.
 905                  */
 906                 char   *r, *w;
 907                 int     c1, c2;
 908
 909                 r = w = namebuf;
 910                 do {
 911                         c1 = *r++;
 912                         if (c1 == '+')
 913                                 c1 = ' ';
 914                         else if (c1 == '%') {
 915                                 c1 = hex_to_bin(*r++);
 916                                 if (c1 < 0)
 917                                         goto out;
 918                                 c2 = hex_to_bin(*r++);
 919                                 if (c2 < 0)
 920                                         goto out;
 921                                 c1 = (c1 << 4) | c2;
 922                         }
 923                         *w++ = c1;
 924                 } while (c1 != '\0');
 925
 926                 objname = namebuf;
 927         }
 928
 929         length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
 930         if (length)
 931                 goto out;
 932
 933         length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
 934         if (length)
 935                 goto out;
 936
 937         length = security_transition_sid_user(state, ssid, tsid, tclass,
 938                                               objname, &newsid);
 939         if (length)
 940                 goto out;
 941
 942         length = security_sid_to_context(state, newsid, &newcon, &len);
 943         if (length)
 944                 goto out;
 945
 946         length = -ERANGE;
 947         if (len > SIMPLE_TRANSACTION_LIMIT) {
 948                 pr_err("SELinux: %s:  context size (%u) exceeds "
 949                         "payload max\n", __func__, len);
 950                 goto out;
 951         }
 952
 953         memcpy(buf, newcon, len);
 954         length = len;
 955 out:
 956         kfree(newcon);
 957         kfree(namebuf);
 958         kfree(tcon);
 959         kfree(scon);
 960         return length;
 961 }
 962
 963 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 964 {
 965         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 966         struct selinux_state *state = fsi->state;
 967         char *scon = NULL, *tcon = NULL;
 968         u32 ssid, tsid, newsid;
 969         u16 tclass;
 970         ssize_t length;
 971         char *newcon = NULL;
 972         u32 len;
 973
 974         length = avc_has_perm(&selinux_state,
 975                               current_sid(), SECINITSID_SECURITY,
 976                               SECCLASS_SECURITY, SECURITY__COMPUTE_RELABEL,
 977                               NULL);
 978         if (length)
 979                 goto out;
 980
 981         length = -ENOMEM;
 982         scon = kzalloc(size + 1, GFP_KERNEL);
 983         if (!scon)
 984                 goto out;
 985
 986         length = -ENOMEM;
 987         tcon = kzalloc(size + 1, GFP_KERNEL);
 988         if (!tcon)
 989                 goto out;
 990
 991         length = -EINVAL;
 992         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 993                 goto out;
 994
 995         length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
 996         if (length)
 997                 goto out;
 998
 999         length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
1000         if (length)
1001                 goto out;
1002
1003         length = security_change_sid(state, ssid, tsid, tclass, &newsid);
1004         if (length)
1005                 goto out;
1006
1007         length = security_sid_to_context(state, newsid, &newcon, &len);
1008         if (length)
1009                 goto out;
1010
1011         length = -ERANGE;
1012         if (len > SIMPLE_TRANSACTION_LIMIT)
1013                 goto out;
1014
1015         memcpy(buf, newcon, len);
1016         length = len;
1017 out:
1018         kfree(newcon);
1019         kfree(tcon);
1020         kfree(scon);
1021         return length;
1022 }
1023
1024 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
1025 {
1026         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1027         struct selinux_state *state = fsi->state;
1028         char *con = NULL, *user = NULL, *ptr;
1029         u32 sid, *sids = NULL;
1030         ssize_t length;
1031         char *newcon;
1032         int i, rc;
1033         u32 len, nsids;
1034
1035         length = avc_has_perm(&selinux_state,
1036                               current_sid(), SECINITSID_SECURITY,
1037                               SECCLASS_SECURITY, SECURITY__COMPUTE_USER,
1038                               NULL);
1039         if (length)
1040                 goto out;
1041
1042         length = -ENOMEM;
1043         con = kzalloc(size + 1, GFP_KERNEL);
1044         if (!con)
1045                 goto out;
1046
1047         length = -ENOMEM;
1048         user = kzalloc(size + 1, GFP_KERNEL);
1049         if (!user)
1050                 goto out;
1051
1052         length = -EINVAL;
1053         if (sscanf(buf, "%s %s", con, user) != 2)
1054                 goto out;
1055
1056         length = security_context_str_to_sid(state, con, &sid, GFP_KERNEL);
1057         if (length)
1058                 goto out;
1059
1060         length = security_get_user_sids(state, sid, user, &sids, &nsids);
1061         if (length)
1062                 goto out;
1063
1064         length = sprintf(buf, "%u", nsids) + 1;
1065         ptr = buf + length;
1066         for (i = 0; i < nsids; i++) {
1067                 rc = security_sid_to_context(state, sids[i], &newcon, &len);
1068                 if (rc) {
1069                         length = rc;
1070                         goto out;
1071                 }
1072                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
1073                         kfree(newcon);
1074                         length = -ERANGE;
1075                         goto out;
1076                 }
1077                 memcpy(ptr, newcon, len);
1078                 kfree(newcon);
1079                 ptr += len;
1080                 length += len;
1081         }
1082 out:
1083         kfree(sids);
1084         kfree(user);
1085         kfree(con);
1086         return length;
1087 }
1088
1089 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
1090 {
1091         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1092         struct selinux_state *state = fsi->state;
1093         char *scon = NULL, *tcon = NULL;
1094         u32 ssid, tsid, newsid;
1095         u16 tclass;
1096         ssize_t length;
1097         char *newcon = NULL;
1098         u32 len;
1099
1100         length = avc_has_perm(&selinux_state,
1101                               current_sid(), SECINITSID_SECURITY,
1102                               SECCLASS_SECURITY, SECURITY__COMPUTE_MEMBER,
1103                               NULL);
1104         if (length)
1105                 goto out;
1106
1107         length = -ENOMEM;
1108         scon = kzalloc(size + 1, GFP_KERNEL);
1109         if (!scon)
1110                 goto out;
1111
1112         length = -ENOMEM;
1113         tcon = kzalloc(size + 1, GFP_KERNEL);
1114         if (!tcon)
1115                 goto out;
1116
1117         length = -EINVAL;
1118         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1119                 goto out;
1120
1121         length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
1122         if (length)
1123                 goto out;
1124
1125         length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
1126         if (length)
1127                 goto out;
1128
1129         length = security_member_sid(state, ssid, tsid, tclass, &newsid);
1130         if (length)
1131                 goto out;
1132
1133         length = security_sid_to_context(state, newsid, &newcon, &len);
1134         if (length)
1135                 goto out;
1136
1137         length = -ERANGE;
1138         if (len > SIMPLE_TRANSACTION_LIMIT) {
1139                 pr_err("SELinux: %s:  context size (%u) exceeds "
1140                         "payload max\n", __func__, len);
1141                 goto out;
1142         }
1143
1144         memcpy(buf, newcon, len);
1145         length = len;
1146 out:
1147         kfree(newcon);
1148         kfree(tcon);
1149         kfree(scon);
1150         return length;
1151 }
1152
1153 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1154 {
1155         struct inode *ret = new_inode(sb);
1156
1157         if (ret) {
1158                 ret->i_mode = mode;
1159                 ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
1160         }
1161         return ret;
1162 }
1163
1164 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1165                              size_t count, loff_t *ppos)
1166 {
1167         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1168         char *page = NULL;
1169         ssize_t length;
1170         ssize_t ret;
1171         int cur_enforcing;
1172         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1173         const char *name = filep->f_path.dentry->d_name.name;
1174
1175         mutex_lock(&fsi->mutex);
1176
1177         ret = -EINVAL;
1178         if (index >= fsi->bool_num || strcmp(name,
1179                                              fsi->bool_pending_names[index]))
1180                 goto out_unlock;
1181
1182         ret = -ENOMEM;
1183         page = (char *)get_zeroed_page(GFP_KERNEL);
1184         if (!page)
1185                 goto out_unlock;
1186
1187         cur_enforcing = security_get_bool_value(fsi->state, index);
1188         if (cur_enforcing < 0) {
1189                 ret = cur_enforcing;
1190                 goto out_unlock;
1191         }
1192         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1193                           fsi->bool_pending_values[index]);
1194         mutex_unlock(&fsi->mutex);
1195         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1196 out_free:
1197         free_page((unsigned long)page);
1198         return ret;
1199
1200 out_unlock:
1201         mutex_unlock(&fsi->mutex);
1202         goto out_free;
1203 }
1204
1205 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1206                               size_t count, loff_t *ppos)
1207 {
1208         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1209         char *page = NULL;
1210         ssize_t length;
1211         int new_value;
1212         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1213         const char *name = filep->f_path.dentry->d_name.name;
1214
1215         if (count >= PAGE_SIZE)
1216                 return -ENOMEM;
1217
1218         /* No partial writes. */
1219         if (*ppos != 0)
1220                 return -EINVAL;
1221
1222         page = memdup_user_nul(buf, count);
1223         if (IS_ERR(page))
1224                 return PTR_ERR(page);
1225
1226         mutex_lock(&fsi->mutex);
1227
1228         length = avc_has_perm(&selinux_state,
1229                               current_sid(), SECINITSID_SECURITY,
1230                               SECCLASS_SECURITY, SECURITY__SETBOOL,
1231                               NULL);
1232         if (length)
1233                 goto out;
1234
1235         length = -EINVAL;
1236         if (index >= fsi->bool_num || strcmp(name,
1237                                              fsi->bool_pending_names[index]))
1238                 goto out;
1239
1240         length = -EINVAL;
1241         if (sscanf(page, "%d", &new_value) != 1)
1242                 goto out;
1243
1244         if (new_value)
1245                 new_value = 1;
1246
1247         fsi->bool_pending_values[index] = new_value;
1248         length = count;
1249
1250 out:
1251         mutex_unlock(&fsi->mutex);
1252         kfree(page);
1253         return length;
1254 }
1255
1256 static const struct file_operations sel_bool_ops = {
1257         .read           = sel_read_bool,
1258         .write          = sel_write_bool,
1259         .llseek         = generic_file_llseek,
1260 };
1261
1262 static ssize_t sel_commit_bools_write(struct file *filep,
1263                                       const char __user *buf,
1264                                       size_t count, loff_t *ppos)
1265 {
1266         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1267         char *page = NULL;
1268         ssize_t length;
1269         int new_value;
1270
1271         if (count >= PAGE_SIZE)
1272                 return -ENOMEM;
1273
1274         /* No partial writes. */
1275         if (*ppos != 0)
1276                 return -EINVAL;
1277
1278         page = memdup_user_nul(buf, count);
1279         if (IS_ERR(page))
1280                 return PTR_ERR(page);
1281
1282         mutex_lock(&fsi->mutex);
1283
1284         length = avc_has_perm(&selinux_state,
1285                               current_sid(), SECINITSID_SECURITY,
1286                               SECCLASS_SECURITY, SECURITY__SETBOOL,
1287                               NULL);
1288         if (length)
1289                 goto out;
1290
1291         length = -EINVAL;
1292         if (sscanf(page, "%d", &new_value) != 1)
1293                 goto out;
1294
1295         length = 0;
1296         if (new_value && fsi->bool_pending_values)
1297                 length = security_set_bools(fsi->state, fsi->bool_num,
1298                                             fsi->bool_pending_values);
1299
1300         if (!length)
1301                 length = count;
1302
1303 out:
1304         mutex_unlock(&fsi->mutex);
1305         kfree(page);
1306         return length;
1307 }
1308
1309 static const struct file_operations sel_commit_bools_ops = {
1310         .write          = sel_commit_bools_write,
1311         .llseek         = generic_file_llseek,
1312 };
1313
1314 static void sel_remove_entries(struct dentry *de)
1315 {
1316         d_genocide(de);
1317         shrink_dcache_parent(de);
1318 }
1319
1320 #define BOOL_DIR_NAME "booleans"
1321
1322 static int sel_make_bools(struct selinux_fs_info *fsi)
1323 {
1324         int i, ret;
1325         ssize_t len;
1326         struct dentry *dentry = NULL;
1327         struct dentry *dir = fsi->bool_dir;
1328         struct inode *inode = NULL;
1329         struct inode_security_struct *isec;
1330         char **names = NULL, *page;
1331         int num;
1332         int *values = NULL;
1333         u32 sid;
1334
1335         /* remove any existing files */
1336         for (i = 0; i < fsi->bool_num; i++)
1337                 kfree(fsi->bool_pending_names[i]);
1338         kfree(fsi->bool_pending_names);
1339         kfree(fsi->bool_pending_values);
1340         fsi->bool_num = 0;
1341         fsi->bool_pending_names = NULL;
1342         fsi->bool_pending_values = NULL;
1343
1344         sel_remove_entries(dir);
1345
1346         ret = -ENOMEM;
1347         page = (char *)get_zeroed_page(GFP_KERNEL);
1348         if (!page)
1349                 goto out;
1350
1351         ret = security_get_bools(fsi->state, &num, &names, &values);
1352         if (ret)
1353                 goto out;
1354
1355         for (i = 0; i < num; i++) {
1356                 ret = -ENOMEM;
1357                 dentry = d_alloc_name(dir, names[i]);
1358                 if (!dentry)
1359                         goto out;
1360
1361                 ret = -ENOMEM;
1362                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1363                 if (!inode) {
1364                         dput(dentry);
1365                         goto out;
1366                 }
1367
1368                 ret = -ENAMETOOLONG;
1369                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1370                 if (len >= PAGE_SIZE) {
1371                         dput(dentry);
1372                         iput(inode);
1373                         goto out;
1374                 }
1375
1376                 isec = selinux_inode(inode);
1377                 ret = security_genfs_sid(fsi->state, "selinuxfs", page,
1378                                          SECCLASS_FILE, &sid);
1379                 if (ret) {
1380                         pr_warn_ratelimited("SELinux: no sid found, defaulting to security isid for %s\n",
1381                                            page);
1382                         sid = SECINITSID_SECURITY;
1383                 }
1384
1385                 isec->sid = sid;
1386                 isec->initialized = LABEL_INITIALIZED;
1387                 inode->i_fop = &sel_bool_ops;
1388                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1389                 d_add(dentry, inode);
1390         }
1391         fsi->bool_num = num;
1392         fsi->bool_pending_names = names;
1393         fsi->bool_pending_values = values;
1394
1395         free_page((unsigned long)page);
1396         return 0;
1397 out:
1398         free_page((unsigned long)page);
1399
1400         if (names) {
1401                 for (i = 0; i < num; i++)
1402                         kfree(names[i]);
1403                 kfree(names);
1404         }
1405         kfree(values);
1406         sel_remove_entries(dir);
1407
1408         return ret;
1409 }
1410
1411 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1412                                             size_t count, loff_t *ppos)
1413 {
1414         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1415         struct selinux_state *state = fsi->state;
1416         char tmpbuf[TMPBUFLEN];
1417         ssize_t length;
1418
1419         length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1420                            avc_get_cache_threshold(state->avc));
1421         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1422 }
1423
1424 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1425                                              const char __user *buf,
1426                                              size_t count, loff_t *ppos)
1427
1428 {
1429         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1430         struct selinux_state *state = fsi->state;
1431         char *page;
1432         ssize_t ret;
1433         unsigned int new_value;
1434
1435         ret = avc_has_perm(&selinux_state,
1436                            current_sid(), SECINITSID_SECURITY,
1437                            SECCLASS_SECURITY, SECURITY__SETSECPARAM,
1438                            NULL);
1439         if (ret)
1440                 return ret;
1441
1442         if (count >= PAGE_SIZE)
1443                 return -ENOMEM;
1444
1445         /* No partial writes. */
1446         if (*ppos != 0)
1447                 return -EINVAL;
1448
1449         page = memdup_user_nul(buf, count);
1450         if (IS_ERR(page))
1451                 return PTR_ERR(page);
1452
1453         ret = -EINVAL;
1454         if (sscanf(page, "%u", &new_value) != 1)
1455                 goto out;
1456
1457         avc_set_cache_threshold(state->avc, new_value);
1458
1459         ret = count;
1460 out:
1461         kfree(page);
1462         return ret;
1463 }
1464
1465 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1466                                        size_t count, loff_t *ppos)
1467 {
1468         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1469         struct selinux_state *state = fsi->state;
1470         char *page;
1471         ssize_t length;
1472
1473         page = (char *)__get_free_page(GFP_KERNEL);
1474         if (!page)
1475                 return -ENOMEM;
1476
1477         length = avc_get_hash_stats(state->avc, page);
1478         if (length >= 0)
1479                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1480         free_page((unsigned long)page);
1481
1482         return length;
1483 }
1484
1485 static const struct file_operations sel_avc_cache_threshold_ops = {
1486         .read           = sel_read_avc_cache_threshold,
1487         .write          = sel_write_avc_cache_threshold,
1488         .llseek         = generic_file_llseek,
1489 };
1490
1491 static const struct file_operations sel_avc_hash_stats_ops = {
1492         .read           = sel_read_avc_hash_stats,
1493         .llseek         = generic_file_llseek,
1494 };
1495
1496 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1497 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1498 {
1499         int cpu;
1500
1501         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1502                 if (!cpu_possible(cpu))
1503                         continue;
1504                 *idx = cpu + 1;
1505                 return &per_cpu(avc_cache_stats, cpu);
1506         }
1507         return NULL;
1508 }
1509
1510 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1511 {
1512         loff_t n = *pos - 1;
1513
1514         if (*pos == 0)
1515                 return SEQ_START_TOKEN;
1516
1517         return sel_avc_get_stat_idx(&n);
1518 }
1519
1520 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1521 {
1522         return sel_avc_get_stat_idx(pos);
1523 }
1524
1525 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1526 {
1527         struct avc_cache_stats *st = v;
1528
1529         if (v == SEQ_START_TOKEN) {
1530                 seq_puts(seq,
1531                          "lookups hits misses allocations reclaims frees\n");
1532         } else {
1533                 unsigned int lookups = st->lookups;
1534                 unsigned int misses = st->misses;
1535                 unsigned int hits = lookups - misses;
1536                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1537                            hits, misses, st->allocations,
1538                            st->reclaims, st->frees);
1539         }
1540         return 0;
1541 }
1542
1543 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1544 { }
1545
1546 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1547         .start          = sel_avc_stats_seq_start,
1548         .next           = sel_avc_stats_seq_next,
1549         .show           = sel_avc_stats_seq_show,
1550         .stop           = sel_avc_stats_seq_stop,
1551 };
1552
1553 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1554 {
1555         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1556 }
1557
1558 static const struct file_operations sel_avc_cache_stats_ops = {
1559         .open           = sel_open_avc_cache_stats,
1560         .read           = seq_read,
1561         .llseek         = seq_lseek,
1562         .release        = seq_release,
1563 };
1564 #endif
1565
1566 static int sel_make_avc_files(struct dentry *dir)
1567 {
1568         struct super_block *sb = dir->d_sb;
1569         struct selinux_fs_info *fsi = sb->s_fs_info;
1570         int i;
1571         static const struct tree_descr files[] = {
1572                 { "cache_threshold",
1573                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1574                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1575 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1576                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1577 #endif
1578         };
1579
1580         for (i = 0; i < ARRAY_SIZE(files); i++) {
1581                 struct inode *inode;
1582                 struct dentry *dentry;
1583
1584                 dentry = d_alloc_name(dir, files[i].name);
1585                 if (!dentry)
1586                         return -ENOMEM;
1587
1588                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1589                 if (!inode) {
1590                         dput(dentry);
1591                         return -ENOMEM;
1592                 }
1593
1594                 inode->i_fop = files[i].ops;
1595                 inode->i_ino = ++fsi->last_ino;
1596                 d_add(dentry, inode);
1597         }
1598
1599         return 0;
1600 }
1601
1602 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1603                                 size_t count, loff_t *ppos)
1604 {
1605         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1606         char *con;
1607         u32 sid, len;
1608         ssize_t ret;
1609
1610         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1611         ret = security_sid_to_context(fsi->state, sid, &con, &len);
1612         if (ret)
1613                 return ret;
1614
1615         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1616         kfree(con);
1617         return ret;
1618 }
1619
1620 static const struct file_operations sel_initcon_ops = {
1621         .read           = sel_read_initcon,
1622         .llseek         = generic_file_llseek,
1623 };
1624
1625 static int sel_make_initcon_files(struct dentry *dir)
1626 {
1627         int i;
1628
1629         for (i = 1; i <= SECINITSID_NUM; i++) {
1630                 struct inode *inode;
1631                 struct dentry *dentry;
1632                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1633                 if (!dentry)
1634                         return -ENOMEM;
1635
1636                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1637                 if (!inode) {
1638                         dput(dentry);
1639                         return -ENOMEM;
1640                 }
1641
1642                 inode->i_fop = &sel_initcon_ops;
1643                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1644                 d_add(dentry, inode);
1645         }
1646
1647         return 0;
1648 }
1649
1650 static inline unsigned long sel_class_to_ino(u16 class)
1651 {
1652         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1653 }
1654
1655 static inline u16 sel_ino_to_class(unsigned long ino)
1656 {
1657         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1658 }
1659
1660 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1661 {
1662         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1663 }
1664
1665 static inline u32 sel_ino_to_perm(unsigned long ino)
1666 {
1667         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1668 }
1669
1670 static ssize_t sel_read_class(struct file *file, char __user *buf,
1671                                 size_t count, loff_t *ppos)
1672 {
1673         unsigned long ino = file_inode(file)->i_ino;
1674         char res[TMPBUFLEN];
1675         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1676         return simple_read_from_buffer(buf, count, ppos, res, len);
1677 }
1678
1679 static const struct file_operations sel_class_ops = {
1680         .read           = sel_read_class,
1681         .llseek         = generic_file_llseek,
1682 };
1683
1684 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1685                                 size_t count, loff_t *ppos)
1686 {
1687         unsigned long ino = file_inode(file)->i_ino;
1688         char res[TMPBUFLEN];
1689         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1690         return simple_read_from_buffer(buf, count, ppos, res, len);
1691 }
1692
1693 static const struct file_operations sel_perm_ops = {
1694         .read           = sel_read_perm,
1695         .llseek         = generic_file_llseek,
1696 };
1697
1698 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1699                                   size_t count, loff_t *ppos)
1700 {
1701         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1702         int value;
1703         char tmpbuf[TMPBUFLEN];
1704         ssize_t length;
1705         unsigned long i_ino = file_inode(file)->i_ino;
1706
1707         value = security_policycap_supported(fsi->state, i_ino & SEL_INO_MASK);
1708         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1709
1710         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1711 }
1712
1713 static const struct file_operations sel_policycap_ops = {
1714         .read           = sel_read_policycap,
1715         .llseek         = generic_file_llseek,
1716 };
1717
1718 static int sel_make_perm_files(char *objclass, int classvalue,
1719                                 struct dentry *dir)
1720 {
1721         struct selinux_fs_info *fsi = dir->d_sb->s_fs_info;
1722         int i, rc, nperms;
1723         char **perms;
1724
1725         rc = security_get_permissions(fsi->state, objclass, &perms, &nperms);
1726         if (rc)
1727                 return rc;
1728
1729         for (i = 0; i < nperms; i++) {
1730                 struct inode *inode;
1731                 struct dentry *dentry;
1732
1733                 rc = -ENOMEM;
1734                 dentry = d_alloc_name(dir, perms[i]);
1735                 if (!dentry)
1736                         goto out;
1737
1738                 rc = -ENOMEM;
1739                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1740                 if (!inode) {
1741                         dput(dentry);
1742                         goto out;
1743                 }
1744
1745                 inode->i_fop = &sel_perm_ops;
1746                 /* i+1 since perm values are 1-indexed */
1747                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1748                 d_add(dentry, inode);
1749         }
1750         rc = 0;
1751 out:
1752         for (i = 0; i < nperms; i++)
1753                 kfree(perms[i]);
1754         kfree(perms);
1755         return rc;
1756 }
1757
1758 static int sel_make_class_dir_entries(char *classname, int index,
1759                                         struct dentry *dir)
1760 {
1761         struct super_block *sb = dir->d_sb;
1762         struct selinux_fs_info *fsi = sb->s_fs_info;
1763         struct dentry *dentry = NULL;
1764         struct inode *inode = NULL;
1765         int rc;
1766
1767         dentry = d_alloc_name(dir, "index");
1768         if (!dentry)
1769                 return -ENOMEM;
1770
1771         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1772         if (!inode) {
1773                 dput(dentry);
1774                 return -ENOMEM;
1775         }
1776
1777         inode->i_fop = &sel_class_ops;
1778         inode->i_ino = sel_class_to_ino(index);
1779         d_add(dentry, inode);
1780
1781         dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino);
1782         if (IS_ERR(dentry))
1783                 return PTR_ERR(dentry);
1784
1785         rc = sel_make_perm_files(classname, index, dentry);
1786
1787         return rc;
1788 }
1789
1790 static int sel_make_classes(struct selinux_fs_info *fsi)
1791 {
1792
1793         int rc, nclasses, i;
1794         char **classes;
1795
1796         /* delete any existing entries */
1797         sel_remove_entries(fsi->class_dir);
1798
1799         rc = security_get_classes(fsi->state, &classes, &nclasses);
1800         if (rc)
1801                 return rc;
1802
1803         /* +2 since classes are 1-indexed */
1804         fsi->last_class_ino = sel_class_to_ino(nclasses + 2);
1805
1806         for (i = 0; i < nclasses; i++) {
1807                 struct dentry *class_name_dir;
1808
1809                 class_name_dir = sel_make_dir(fsi->class_dir, classes[i],
1810                                               &fsi->last_class_ino);
1811                 if (IS_ERR(class_name_dir)) {
1812                         rc = PTR_ERR(class_name_dir);
1813                         goto out;
1814                 }
1815
1816                 /* i+1 since class values are 1-indexed */
1817                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1818                                 class_name_dir);
1819                 if (rc)
1820                         goto out;
1821         }
1822         rc = 0;
1823 out:
1824         for (i = 0; i < nclasses; i++)
1825                 kfree(classes[i]);
1826         kfree(classes);
1827         return rc;
1828 }
1829
1830 static int sel_make_policycap(struct selinux_fs_info *fsi)
1831 {
1832         unsigned int iter;
1833         struct dentry *dentry = NULL;
1834         struct inode *inode = NULL;
1835
1836         sel_remove_entries(fsi->policycap_dir);
1837
1838         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1839                 if (iter < ARRAY_SIZE(selinux_policycap_names))
1840                         dentry = d_alloc_name(fsi->policycap_dir,
1841                                               selinux_policycap_names[iter]);
1842                 else
1843                         dentry = d_alloc_name(fsi->policycap_dir, "unknown");
1844
1845                 if (dentry == NULL)
1846                         return -ENOMEM;
1847
1848                 inode = sel_make_inode(fsi->sb, S_IFREG | 0444);
1849                 if (inode == NULL) {
1850                         dput(dentry);
1851                         return -ENOMEM;
1852                 }
1853
1854                 inode->i_fop = &sel_policycap_ops;
1855                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1856                 d_add(dentry, inode);
1857         }
1858
1859         return 0;
1860 }
1861
1862 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1863                         unsigned long *ino)
1864 {
1865         struct dentry *dentry = d_alloc_name(dir, name);
1866         struct inode *inode;
1867
1868         if (!dentry)
1869                 return ERR_PTR(-ENOMEM);
1870
1871         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1872         if (!inode) {
1873                 dput(dentry);
1874                 return ERR_PTR(-ENOMEM);
1875         }
1876
1877         inode->i_op = &simple_dir_inode_operations;
1878         inode->i_fop = &simple_dir_operations;
1879         inode->i_ino = ++(*ino);
1880         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1881         inc_nlink(inode);
1882         d_add(dentry, inode);
1883         /* bump link count on parent directory, too */
1884         inc_nlink(d_inode(dir));
1885
1886         return dentry;
1887 }
1888
1889 #define NULL_FILE_NAME "null"
1890
1891 static int sel_fill_super(struct super_block *sb, struct fs_context *fc)
1892 {
1893         struct selinux_fs_info *fsi;
1894         int ret;
1895         struct dentry *dentry;
1896         struct inode *inode;
1897         struct inode_security_struct *isec;
1898
1899         static const struct tree_descr selinux_files[] = {
1900                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1901                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1902                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1903                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1904                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1905                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1906                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1907                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1908                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1909                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1910                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1911                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1912                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1913                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1914                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1915                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1916                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1917                 [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops,
1918                                         S_IWUGO},
1919                 /* last one */ {""}
1920         };
1921
1922         ret = selinux_fs_info_create(sb);
1923         if (ret)
1924                 goto err;
1925
1926         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1927         if (ret)
1928                 goto err;
1929
1930         fsi = sb->s_fs_info;
1931         fsi->bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &fsi->last_ino);
1932         if (IS_ERR(fsi->bool_dir)) {
1933                 ret = PTR_ERR(fsi->bool_dir);
1934                 fsi->bool_dir = NULL;
1935                 goto err;
1936         }
1937
1938         ret = -ENOMEM;
1939         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1940         if (!dentry)
1941                 goto err;
1942
1943         ret = -ENOMEM;
1944         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1945         if (!inode) {
1946                 dput(dentry);
1947                 goto err;
1948         }
1949
1950         inode->i_ino = ++fsi->last_ino;
1951         isec = selinux_inode(inode);
1952         isec->sid = SECINITSID_DEVNULL;
1953         isec->sclass = SECCLASS_CHR_FILE;
1954         isec->initialized = LABEL_INITIALIZED;
1955
1956         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1957         d_add(dentry, inode);
1958
1959         dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino);
1960         if (IS_ERR(dentry)) {
1961                 ret = PTR_ERR(dentry);
1962                 goto err;
1963         }
1964
1965         ret = sel_make_avc_files(dentry);
1966         if (ret)
1967                 goto err;
1968
1969         dentry = sel_make_dir(sb->s_root, "initial_contexts", &fsi->last_ino);
1970         if (IS_ERR(dentry)) {
1971                 ret = PTR_ERR(dentry);
1972                 goto err;
1973         }
1974
1975         ret = sel_make_initcon_files(dentry);
1976         if (ret)
1977                 goto err;
1978
1979         fsi->class_dir = sel_make_dir(sb->s_root, "class", &fsi->last_ino);
1980         if (IS_ERR(fsi->class_dir)) {
1981                 ret = PTR_ERR(fsi->class_dir);
1982                 fsi->class_dir = NULL;
1983                 goto err;
1984         }
1985
1986         fsi->policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities",
1987                                           &fsi->last_ino);
1988         if (IS_ERR(fsi->policycap_dir)) {
1989                 ret = PTR_ERR(fsi->policycap_dir);
1990                 fsi->policycap_dir = NULL;
1991                 goto err;
1992         }
1993
1994         ret = sel_make_policy_nodes(fsi);
1995         if (ret)
1996                 goto err;
1997         return 0;
1998 err:
1999         pr_err("SELinux: %s:  failed while creating inodes\n",
2000                 __func__);
2001
2002         selinux_fs_info_free(sb);
2003
2004         return ret;
2005 }
2006
2007 static int sel_get_tree(struct fs_context *fc)
2008 {
2009         return get_tree_single(fc, sel_fill_super);
2010 }
2011
2012 static const struct fs_context_operations sel_context_ops = {
2013         .get_tree       = sel_get_tree,
2014 };
2015
2016 static int sel_init_fs_context(struct fs_context *fc)
2017 {
2018         fc->ops = &sel_context_ops;
2019         return 0;
2020 }
2021
2022 static void sel_kill_sb(struct super_block *sb)
2023 {
2024         selinux_fs_info_free(sb);
2025         kill_litter_super(sb);
2026 }
2027
2028 static struct file_system_type sel_fs_type = {
2029         .name           = "selinuxfs",
2030         .init_fs_context = sel_init_fs_context,
2031         .kill_sb        = sel_kill_sb,
2032 };
2033
2034 struct vfsmount *selinuxfs_mount;
2035 struct path selinux_null;
2036
2037 static int __init init_sel_fs(void)
2038 {
2039         struct qstr null_name = QSTR_INIT(NULL_FILE_NAME,
2040                                           sizeof(NULL_FILE_NAME)-1);
2041         int err;
2042
2043         if (!selinux_enabled)
2044                 return 0;
2045
2046         err = sysfs_create_mount_point(fs_kobj, "selinux");
2047         if (err)
2048                 return err;
2049
2050         err = register_filesystem(&sel_fs_type);
2051         if (err) {
2052                 sysfs_remove_mount_point(fs_kobj, "selinux");
2053                 return err;
2054         }
2055
2056         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
2057         if (IS_ERR(selinuxfs_mount)) {
2058                 pr_err("selinuxfs:  could not mount!\n");
2059                 err = PTR_ERR(selinuxfs_mount);
2060                 selinuxfs_mount = NULL;
2061         }
2062         selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root,
2063                                                 &null_name);
2064         if (IS_ERR(selinux_null.dentry)) {
2065                 pr_err("selinuxfs:  could not lookup null!\n");
2066                 err = PTR_ERR(selinux_null.dentry);
2067                 selinux_null.dentry = NULL;
2068         }
2069
2070         return err;
2071 }
2072
2073 __initcall(init_sel_fs);
2074
2075 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
2076 void exit_sel_fs(void)
2077 {
2078         sysfs_remove_mount_point(fs_kobj, "selinux");
2079         dput(selinux_null.dentry);
2080         kern_unmount(selinuxfs_mount);
2081         unregister_filesystem(&sel_fs_type);
2082 }
2083 #endif