git.rot13.org Git - linux/blob - 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                         " 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(current->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 policy_load_memory *plm = filp->private_data;
 445         int ret;
 446
 447         ret = avc_has_perm(&selinux_state,
 448                            current_sid(), SECINITSID_SECURITY,
 449                           SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
 450         if (ret)
 451                 return ret;
 452
 453         return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 454 }
 455
 456 static vm_fault_t 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                 "auid=%u ses=%u lsm=selinux res=1",
 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_unlock;
1186
1187         ret = -ENOMEM;
1188         page = (char *)get_zeroed_page(GFP_KERNEL);
1189         if (!page)
1190                 goto out_unlock;
1191
1192         cur_enforcing = security_get_bool_value(fsi->state, index);
1193         if (cur_enforcing < 0) {
1194                 ret = cur_enforcing;
1195                 goto out_unlock;
1196         }
1197         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1198                           fsi->bool_pending_values[index]);
1199         mutex_unlock(&fsi->mutex);
1200         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1201 out_free:
1202         free_page((unsigned long)page);
1203         return ret;
1204
1205 out_unlock:
1206         mutex_unlock(&fsi->mutex);
1207         goto out_free;
1208 }
1209
1210 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1211                               size_t count, loff_t *ppos)
1212 {
1213         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1214         char *page = NULL;
1215         ssize_t length;
1216         int new_value;
1217         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1218         const char *name = filep->f_path.dentry->d_name.name;
1219
1220         if (count >= PAGE_SIZE)
1221                 return -ENOMEM;
1222
1223         /* No partial writes. */
1224         if (*ppos != 0)
1225                 return -EINVAL;
1226
1227         page = memdup_user_nul(buf, count);
1228         if (IS_ERR(page))
1229                 return PTR_ERR(page);
1230
1231         mutex_lock(&fsi->mutex);
1232
1233         length = avc_has_perm(&selinux_state,
1234                               current_sid(), SECINITSID_SECURITY,
1235                               SECCLASS_SECURITY, SECURITY__SETBOOL,
1236                               NULL);
1237         if (length)
1238                 goto out;
1239
1240         length = -EINVAL;
1241         if (index >= fsi->bool_num || strcmp(name,
1242                                              fsi->bool_pending_names[index]))
1243                 goto out;
1244
1245         length = -EINVAL;
1246         if (sscanf(page, "%d", &new_value) != 1)
1247                 goto out;
1248
1249         if (new_value)
1250                 new_value = 1;
1251
1252         fsi->bool_pending_values[index] = new_value;
1253         length = count;
1254
1255 out:
1256         mutex_unlock(&fsi->mutex);
1257         kfree(page);
1258         return length;
1259 }
1260
1261 static const struct file_operations sel_bool_ops = {
1262         .read           = sel_read_bool,
1263         .write          = sel_write_bool,
1264         .llseek         = generic_file_llseek,
1265 };
1266
1267 static ssize_t sel_commit_bools_write(struct file *filep,
1268                                       const char __user *buf,
1269                                       size_t count, loff_t *ppos)
1270 {
1271         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1272         char *page = NULL;
1273         ssize_t length;
1274         int new_value;
1275
1276         if (count >= PAGE_SIZE)
1277                 return -ENOMEM;
1278
1279         /* No partial writes. */
1280         if (*ppos != 0)
1281                 return -EINVAL;
1282
1283         page = memdup_user_nul(buf, count);
1284         if (IS_ERR(page))
1285                 return PTR_ERR(page);
1286
1287         mutex_lock(&fsi->mutex);
1288
1289         length = avc_has_perm(&selinux_state,
1290                               current_sid(), SECINITSID_SECURITY,
1291                               SECCLASS_SECURITY, SECURITY__SETBOOL,
1292                               NULL);
1293         if (length)
1294                 goto out;
1295
1296         length = -EINVAL;
1297         if (sscanf(page, "%d", &new_value) != 1)
1298                 goto out;
1299
1300         length = 0;
1301         if (new_value && fsi->bool_pending_values)
1302                 length = security_set_bools(fsi->state, fsi->bool_num,
1303                                             fsi->bool_pending_values);
1304
1305         if (!length)
1306                 length = count;
1307
1308 out:
1309         mutex_unlock(&fsi->mutex);
1310         kfree(page);
1311         return length;
1312 }
1313
1314 static const struct file_operations sel_commit_bools_ops = {
1315         .write          = sel_commit_bools_write,
1316         .llseek         = generic_file_llseek,
1317 };
1318
1319 static void sel_remove_entries(struct dentry *de)
1320 {
1321         d_genocide(de);
1322         shrink_dcache_parent(de);
1323 }
1324
1325 #define BOOL_DIR_NAME "booleans"
1326
1327 static int sel_make_bools(struct selinux_fs_info *fsi)
1328 {
1329         int i, ret;
1330         ssize_t len;
1331         struct dentry *dentry = NULL;
1332         struct dentry *dir = fsi->bool_dir;
1333         struct inode *inode = NULL;
1334         struct inode_security_struct *isec;
1335         char **names = NULL, *page;
1336         int num;
1337         int *values = NULL;
1338         u32 sid;
1339
1340         /* remove any existing files */
1341         for (i = 0; i < fsi->bool_num; i++)
1342                 kfree(fsi->bool_pending_names[i]);
1343         kfree(fsi->bool_pending_names);
1344         kfree(fsi->bool_pending_values);
1345         fsi->bool_num = 0;
1346         fsi->bool_pending_names = NULL;
1347         fsi->bool_pending_values = NULL;
1348
1349         sel_remove_entries(dir);
1350
1351         ret = -ENOMEM;
1352         page = (char *)get_zeroed_page(GFP_KERNEL);
1353         if (!page)
1354                 goto out;
1355
1356         ret = security_get_bools(fsi->state, &num, &names, &values);
1357         if (ret)
1358                 goto out;
1359
1360         for (i = 0; i < num; i++) {
1361                 ret = -ENOMEM;
1362                 dentry = d_alloc_name(dir, names[i]);
1363                 if (!dentry)
1364                         goto out;
1365
1366                 ret = -ENOMEM;
1367                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1368                 if (!inode)
1369                         goto out;
1370
1371                 ret = -ENAMETOOLONG;
1372                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1373                 if (len >= PAGE_SIZE)
1374                         goto out;
1375
1376                 isec = (struct inode_security_struct *)inode->i_security;
1377                 ret = security_genfs_sid(fsi->state, "selinuxfs", page,
1378                                          SECCLASS_FILE, &sid);
1379                 if (ret) {
1380                         pr_warn_ratelimited("SELinux: no sid found, defaulting to security isid for %s\n",
1381                                            page);
1382                         sid = SECINITSID_SECURITY;
1383                 }
1384
1385                 isec->sid = sid;
1386                 isec->initialized = LABEL_INITIALIZED;
1387                 inode->i_fop = &sel_bool_ops;
1388                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1389                 d_add(dentry, inode);
1390         }
1391         fsi->bool_num = num;
1392         fsi->bool_pending_names = names;
1393         fsi->bool_pending_values = values;
1394
1395         free_page((unsigned long)page);
1396         return 0;
1397 out:
1398         free_page((unsigned long)page);
1399
1400         if (names) {
1401                 for (i = 0; i < num; i++)
1402                         kfree(names[i]);
1403                 kfree(names);
1404         }
1405         kfree(values);
1406         sel_remove_entries(dir);
1407
1408         return ret;
1409 }
1410
1411 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1412                                             size_t count, loff_t *ppos)
1413 {
1414         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1415         struct selinux_state *state = fsi->state;
1416         char tmpbuf[TMPBUFLEN];
1417         ssize_t length;
1418
1419         length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1420                            avc_get_cache_threshold(state->avc));
1421         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1422 }
1423
1424 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1425                                              const char __user *buf,
1426                                              size_t count, loff_t *ppos)
1427
1428 {
1429         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1430         struct selinux_state *state = fsi->state;
1431         char *page;
1432         ssize_t ret;
1433         unsigned int new_value;
1434
1435         ret = avc_has_perm(&selinux_state,
1436                            current_sid(), SECINITSID_SECURITY,
1437                            SECCLASS_SECURITY, SECURITY__SETSECPARAM,
1438                            NULL);
1439         if (ret)
1440                 return ret;
1441
1442         if (count >= PAGE_SIZE)
1443                 return -ENOMEM;
1444
1445         /* No partial writes. */
1446         if (*ppos != 0)
1447                 return -EINVAL;
1448
1449         page = memdup_user_nul(buf, count);
1450         if (IS_ERR(page))
1451                 return PTR_ERR(page);
1452
1453         ret = -EINVAL;
1454         if (sscanf(page, "%u", &new_value) != 1)
1455                 goto out;
1456
1457         avc_set_cache_threshold(state->avc, new_value);
1458
1459         ret = count;
1460 out:
1461         kfree(page);
1462         return ret;
1463 }
1464
1465 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1466                                        size_t count, loff_t *ppos)
1467 {
1468         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1469         struct selinux_state *state = fsi->state;
1470         char *page;
1471         ssize_t length;
1472
1473         page = (char *)__get_free_page(GFP_KERNEL);
1474         if (!page)
1475                 return -ENOMEM;
1476
1477         length = avc_get_hash_stats(state->avc, page);
1478         if (length >= 0)
1479                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1480         free_page((unsigned long)page);
1481
1482         return length;
1483 }
1484
1485 static const struct file_operations sel_avc_cache_threshold_ops = {
1486         .read           = sel_read_avc_cache_threshold,
1487         .write          = sel_write_avc_cache_threshold,
1488         .llseek         = generic_file_llseek,
1489 };
1490
1491 static const struct file_operations sel_avc_hash_stats_ops = {
1492         .read           = sel_read_avc_hash_stats,
1493         .llseek         = generic_file_llseek,
1494 };
1495
1496 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1497 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1498 {
1499         int cpu;
1500
1501         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1502                 if (!cpu_possible(cpu))
1503                         continue;
1504                 *idx = cpu + 1;
1505                 return &per_cpu(avc_cache_stats, cpu);
1506         }
1507         return NULL;
1508 }
1509
1510 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1511 {
1512         loff_t n = *pos - 1;
1513
1514         if (*pos == 0)
1515                 return SEQ_START_TOKEN;
1516
1517         return sel_avc_get_stat_idx(&n);
1518 }
1519
1520 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1521 {
1522         return sel_avc_get_stat_idx(pos);
1523 }
1524
1525 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1526 {
1527         struct avc_cache_stats *st = v;
1528
1529         if (v == SEQ_START_TOKEN) {
1530                 seq_puts(seq,
1531                          "lookups hits misses allocations reclaims frees\n");
1532         } else {
1533                 unsigned int lookups = st->lookups;
1534                 unsigned int misses = st->misses;
1535                 unsigned int hits = lookups - misses;
1536                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1537                            hits, misses, st->allocations,
1538                            st->reclaims, st->frees);
1539         }
1540         return 0;
1541 }
1542
1543 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1544 { }
1545
1546 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1547         .start          = sel_avc_stats_seq_start,
1548         .next           = sel_avc_stats_seq_next,
1549         .show           = sel_avc_stats_seq_show,
1550         .stop           = sel_avc_stats_seq_stop,
1551 };
1552
1553 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1554 {
1555         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1556 }
1557
1558 static const struct file_operations sel_avc_cache_stats_ops = {
1559         .open           = sel_open_avc_cache_stats,
1560         .read           = seq_read,
1561         .llseek         = seq_lseek,
1562         .release        = seq_release,
1563 };
1564 #endif
1565
1566 static int sel_make_avc_files(struct dentry *dir)
1567 {
1568         struct super_block *sb = dir->d_sb;
1569         struct selinux_fs_info *fsi = sb->s_fs_info;
1570         int i;
1571         static const struct tree_descr files[] = {
1572                 { "cache_threshold",
1573                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1574                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1575 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1576                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1577 #endif
1578         };
1579
1580         for (i = 0; i < ARRAY_SIZE(files); i++) {
1581                 struct inode *inode;
1582                 struct dentry *dentry;
1583
1584                 dentry = d_alloc_name(dir, files[i].name);
1585                 if (!dentry)
1586                         return -ENOMEM;
1587
1588                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1589                 if (!inode)
1590                         return -ENOMEM;
1591
1592                 inode->i_fop = files[i].ops;
1593                 inode->i_ino = ++fsi->last_ino;
1594                 d_add(dentry, inode);
1595         }
1596
1597         return 0;
1598 }
1599
1600 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1601                                 size_t count, loff_t *ppos)
1602 {
1603         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1604         char *con;
1605         u32 sid, len;
1606         ssize_t ret;
1607
1608         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1609         ret = security_sid_to_context(fsi->state, sid, &con, &len);
1610         if (ret)
1611                 return ret;
1612
1613         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1614         kfree(con);
1615         return ret;
1616 }
1617
1618 static const struct file_operations sel_initcon_ops = {
1619         .read           = sel_read_initcon,
1620         .llseek         = generic_file_llseek,
1621 };
1622
1623 static int sel_make_initcon_files(struct dentry *dir)
1624 {
1625         int i;
1626
1627         for (i = 1; i <= SECINITSID_NUM; i++) {
1628                 struct inode *inode;
1629                 struct dentry *dentry;
1630                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1631                 if (!dentry)
1632                         return -ENOMEM;
1633
1634                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1635                 if (!inode)
1636                         return -ENOMEM;
1637
1638                 inode->i_fop = &sel_initcon_ops;
1639                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1640                 d_add(dentry, inode);
1641         }
1642
1643         return 0;
1644 }
1645
1646 static inline unsigned long sel_class_to_ino(u16 class)
1647 {
1648         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1649 }
1650
1651 static inline u16 sel_ino_to_class(unsigned long ino)
1652 {
1653         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1654 }
1655
1656 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1657 {
1658         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1659 }
1660
1661 static inline u32 sel_ino_to_perm(unsigned long ino)
1662 {
1663         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1664 }
1665
1666 static ssize_t sel_read_class(struct file *file, char __user *buf,
1667                                 size_t count, loff_t *ppos)
1668 {
1669         unsigned long ino = file_inode(file)->i_ino;
1670         char res[TMPBUFLEN];
1671         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1672         return simple_read_from_buffer(buf, count, ppos, res, len);
1673 }
1674
1675 static const struct file_operations sel_class_ops = {
1676         .read           = sel_read_class,
1677         .llseek         = generic_file_llseek,
1678 };
1679
1680 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1681                                 size_t count, loff_t *ppos)
1682 {
1683         unsigned long ino = file_inode(file)->i_ino;
1684         char res[TMPBUFLEN];
1685         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1686         return simple_read_from_buffer(buf, count, ppos, res, len);
1687 }
1688
1689 static const struct file_operations sel_perm_ops = {
1690         .read           = sel_read_perm,
1691         .llseek         = generic_file_llseek,
1692 };
1693
1694 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1695                                   size_t count, loff_t *ppos)
1696 {
1697         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1698         int value;
1699         char tmpbuf[TMPBUFLEN];
1700         ssize_t length;
1701         unsigned long i_ino = file_inode(file)->i_ino;
1702
1703         value = security_policycap_supported(fsi->state, i_ino & SEL_INO_MASK);
1704         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1705
1706         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1707 }
1708
1709 static const struct file_operations sel_policycap_ops = {
1710         .read           = sel_read_policycap,
1711         .llseek         = generic_file_llseek,
1712 };
1713
1714 static int sel_make_perm_files(char *objclass, int classvalue,
1715                                 struct dentry *dir)
1716 {
1717         struct selinux_fs_info *fsi = dir->d_sb->s_fs_info;
1718         int i, rc, nperms;
1719         char **perms;
1720
1721         rc = security_get_permissions(fsi->state, objclass, &perms, &nperms);
1722         if (rc)
1723                 return rc;
1724
1725         for (i = 0; i < nperms; i++) {
1726                 struct inode *inode;
1727                 struct dentry *dentry;
1728
1729                 rc = -ENOMEM;
1730                 dentry = d_alloc_name(dir, perms[i]);
1731                 if (!dentry)
1732                         goto out;
1733
1734                 rc = -ENOMEM;
1735                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1736                 if (!inode)
1737                         goto out;
1738
1739                 inode->i_fop = &sel_perm_ops;
1740                 /* i+1 since perm values are 1-indexed */
1741                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1742                 d_add(dentry, inode);
1743         }
1744         rc = 0;
1745 out:
1746         for (i = 0; i < nperms; i++)
1747                 kfree(perms[i]);
1748         kfree(perms);
1749         return rc;
1750 }
1751
1752 static int sel_make_class_dir_entries(char *classname, int index,
1753                                         struct dentry *dir)
1754 {
1755         struct super_block *sb = dir->d_sb;
1756         struct selinux_fs_info *fsi = sb->s_fs_info;
1757         struct dentry *dentry = NULL;
1758         struct inode *inode = NULL;
1759         int rc;
1760
1761         dentry = d_alloc_name(dir, "index");
1762         if (!dentry)
1763                 return -ENOMEM;
1764
1765         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1766         if (!inode)
1767                 return -ENOMEM;
1768
1769         inode->i_fop = &sel_class_ops;
1770         inode->i_ino = sel_class_to_ino(index);
1771         d_add(dentry, inode);
1772
1773         dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino);
1774         if (IS_ERR(dentry))
1775                 return PTR_ERR(dentry);
1776
1777         rc = sel_make_perm_files(classname, index, dentry);
1778
1779         return rc;
1780 }
1781
1782 static int sel_make_classes(struct selinux_fs_info *fsi)
1783 {
1784
1785         int rc, nclasses, i;
1786         char **classes;
1787
1788         /* delete any existing entries */
1789         sel_remove_entries(fsi->class_dir);
1790
1791         rc = security_get_classes(fsi->state, &classes, &nclasses);
1792         if (rc)
1793                 return rc;
1794
1795         /* +2 since classes are 1-indexed */
1796         fsi->last_class_ino = sel_class_to_ino(nclasses + 2);
1797
1798         for (i = 0; i < nclasses; i++) {
1799                 struct dentry *class_name_dir;
1800
1801                 class_name_dir = sel_make_dir(fsi->class_dir, classes[i],
1802                                               &fsi->last_class_ino);
1803                 if (IS_ERR(class_name_dir)) {
1804                         rc = PTR_ERR(class_name_dir);
1805                         goto out;
1806                 }
1807
1808                 /* i+1 since class values are 1-indexed */
1809                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1810                                 class_name_dir);
1811                 if (rc)
1812                         goto out;
1813         }
1814         rc = 0;
1815 out:
1816         for (i = 0; i < nclasses; i++)
1817                 kfree(classes[i]);
1818         kfree(classes);
1819         return rc;
1820 }
1821
1822 static int sel_make_policycap(struct selinux_fs_info *fsi)
1823 {
1824         unsigned int iter;
1825         struct dentry *dentry = NULL;
1826         struct inode *inode = NULL;
1827
1828         sel_remove_entries(fsi->policycap_dir);
1829
1830         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1831                 if (iter < ARRAY_SIZE(selinux_policycap_names))
1832                         dentry = d_alloc_name(fsi->policycap_dir,
1833                                               selinux_policycap_names[iter]);
1834                 else
1835                         dentry = d_alloc_name(fsi->policycap_dir, "unknown");
1836
1837                 if (dentry == NULL)
1838                         return -ENOMEM;
1839
1840                 inode = sel_make_inode(fsi->sb, S_IFREG | 0444);
1841                 if (inode == NULL)
1842                         return -ENOMEM;
1843
1844                 inode->i_fop = &sel_policycap_ops;
1845                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1846                 d_add(dentry, inode);
1847         }
1848
1849         return 0;
1850 }
1851
1852 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1853                         unsigned long *ino)
1854 {
1855         struct dentry *dentry = d_alloc_name(dir, name);
1856         struct inode *inode;
1857
1858         if (!dentry)
1859                 return ERR_PTR(-ENOMEM);
1860
1861         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1862         if (!inode) {
1863                 dput(dentry);
1864                 return ERR_PTR(-ENOMEM);
1865         }
1866
1867         inode->i_op = &simple_dir_inode_operations;
1868         inode->i_fop = &simple_dir_operations;
1869         inode->i_ino = ++(*ino);
1870         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1871         inc_nlink(inode);
1872         d_add(dentry, inode);
1873         /* bump link count on parent directory, too */
1874         inc_nlink(d_inode(dir));
1875
1876         return dentry;
1877 }
1878
1879 #define NULL_FILE_NAME "null"
1880
1881 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1882 {
1883         struct selinux_fs_info *fsi;
1884         int ret;
1885         struct dentry *dentry;
1886         struct inode *inode;
1887         struct inode_security_struct *isec;
1888
1889         static const struct tree_descr selinux_files[] = {
1890                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1891                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1892                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1893                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1894                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1895                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1896                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1897                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1898                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1899                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1900                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1901                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1902                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1903                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1904                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1905                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1906                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1907                 [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops,
1908                                         S_IWUGO},
1909                 /* last one */ {""}
1910         };
1911
1912         ret = selinux_fs_info_create(sb);
1913         if (ret)
1914                 goto err;
1915
1916         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1917         if (ret)
1918                 goto err;
1919
1920         fsi = sb->s_fs_info;
1921         fsi->bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &fsi->last_ino);
1922         if (IS_ERR(fsi->bool_dir)) {
1923                 ret = PTR_ERR(fsi->bool_dir);
1924                 fsi->bool_dir = NULL;
1925                 goto err;
1926         }
1927
1928         ret = -ENOMEM;
1929         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1930         if (!dentry)
1931                 goto err;
1932
1933         ret = -ENOMEM;
1934         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1935         if (!inode)
1936                 goto err;
1937
1938         inode->i_ino = ++fsi->last_ino;
1939         isec = (struct inode_security_struct *)inode->i_security;
1940         isec->sid = SECINITSID_DEVNULL;
1941         isec->sclass = SECCLASS_CHR_FILE;
1942         isec->initialized = LABEL_INITIALIZED;
1943
1944         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1945         d_add(dentry, inode);
1946
1947         dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino);
1948         if (IS_ERR(dentry)) {
1949                 ret = PTR_ERR(dentry);
1950                 goto err;
1951         }
1952
1953         ret = sel_make_avc_files(dentry);
1954         if (ret)
1955                 goto err;
1956
1957         dentry = sel_make_dir(sb->s_root, "initial_contexts", &fsi->last_ino);
1958         if (IS_ERR(dentry)) {
1959                 ret = PTR_ERR(dentry);
1960                 goto err;
1961         }
1962
1963         ret = sel_make_initcon_files(dentry);
1964         if (ret)
1965                 goto err;
1966
1967         fsi->class_dir = sel_make_dir(sb->s_root, "class", &fsi->last_ino);
1968         if (IS_ERR(fsi->class_dir)) {
1969                 ret = PTR_ERR(fsi->class_dir);
1970                 fsi->class_dir = NULL;
1971                 goto err;
1972         }
1973
1974         fsi->policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities",
1975                                           &fsi->last_ino);
1976         if (IS_ERR(fsi->policycap_dir)) {
1977                 ret = PTR_ERR(fsi->policycap_dir);
1978                 fsi->policycap_dir = NULL;
1979                 goto err;
1980         }
1981
1982         ret = sel_make_policy_nodes(fsi);
1983         if (ret)
1984                 goto err;
1985         return 0;
1986 err:
1987         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1988                 __func__);
1989
1990         selinux_fs_info_free(sb);
1991
1992         return ret;
1993 }
1994
1995 static struct dentry *sel_mount(struct file_system_type *fs_type,
1996                       int flags, const char *dev_name, void *data)
1997 {
1998         return mount_single(fs_type, flags, data, sel_fill_super);
1999 }
2000
2001 static void sel_kill_sb(struct super_block *sb)
2002 {
2003         selinux_fs_info_free(sb);
2004         kill_litter_super(sb);
2005 }
2006
2007 static struct file_system_type sel_fs_type = {
2008         .name           = "selinuxfs",
2009         .mount          = sel_mount,
2010         .kill_sb        = sel_kill_sb,
2011 };
2012
2013 struct vfsmount *selinuxfs_mount;
2014 struct path selinux_null;
2015
2016 static int __init init_sel_fs(void)
2017 {
2018         struct qstr null_name = QSTR_INIT(NULL_FILE_NAME,
2019                                           sizeof(NULL_FILE_NAME)-1);
2020         int err;
2021
2022         if (!selinux_enabled)
2023                 return 0;
2024
2025         err = sysfs_create_mount_point(fs_kobj, "selinux");
2026         if (err)
2027                 return err;
2028
2029         err = register_filesystem(&sel_fs_type);
2030         if (err) {
2031                 sysfs_remove_mount_point(fs_kobj, "selinux");
2032                 return err;
2033         }
2034
2035         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
2036         if (IS_ERR(selinuxfs_mount)) {
2037                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
2038                 err = PTR_ERR(selinuxfs_mount);
2039                 selinuxfs_mount = NULL;
2040         }
2041         selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root,
2042                                                 &null_name);
2043         if (IS_ERR(selinux_null.dentry)) {
2044                 pr_err("selinuxfs:  could not lookup null!\n");
2045                 err = PTR_ERR(selinux_null.dentry);
2046                 selinux_null.dentry = NULL;
2047         }
2048
2049         return err;
2050 }
2051
2052 __initcall(init_sel_fs);
2053
2054 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
2055 void exit_sel_fs(void)
2056 {
2057         sysfs_remove_mount_point(fs_kobj, "selinux");
2058         dput(selinux_null.dentry);
2059         kern_unmount(selinuxfs_mount);
2060         unregister_filesystem(&sel_fs_type);
2061 }
2062 #endif