security/selinux/selinuxfs.c

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