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