1// SPDX-License-Identifier: GPL-2.0-only
   2/* Updated: Karl MacMillan <kmacmillan@tresys.com>
   3 *
   4 *	Added conditional policy language extensions
   5 *
   6 *  Updated: Hewlett-Packard <paul@paul-moore.com>
   7 *
   8 *	Added support for the policy capability bitmap
   9 *
  10 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
  11 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  12 * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
  13 */
  14
  15#include <linux/kernel.h>
  16#include <linux/pagemap.h>
  17#include <linux/slab.h>
  18#include <linux/vmalloc.h>
  19#include <linux/fs.h>
  20#include <linux/fs_context.h>
  21#include <linux/mount.h>
  22#include <linux/mutex.h>
 
  23#include <linux/init.h>
  24#include <linux/string.h>
  25#include <linux/security.h>
  26#include <linux/major.h>
  27#include <linux/seq_file.h>
  28#include <linux/percpu.h>
  29#include <linux/audit.h>
  30#include <linux/uaccess.h>
  31#include <linux/kobject.h>
  32#include <linux/ctype.h>
  33
  34/* selinuxfs pseudo filesystem for exporting the security policy API.
  35   Based on the proc code and the fs/nfsd/nfsctl.c code. */
  36
  37#include "flask.h"
  38#include "avc.h"
  39#include "avc_ss.h"
  40#include "security.h"
  41#include "objsec.h"
  42#include "conditional.h"
 
  43
  44enum sel_inos {
  45	SEL_ROOT_INO = 2,
  46	SEL_LOAD,	/* load policy */
  47	SEL_ENFORCE,	/* get or set enforcing status */
  48	SEL_CONTEXT,	/* validate context */
  49	SEL_ACCESS,	/* compute access decision */
  50	SEL_CREATE,	/* compute create labeling decision */
  51	SEL_RELABEL,	/* compute relabeling decision */
  52	SEL_USER,	/* compute reachable user contexts */
  53	SEL_POLICYVERS,	/* return policy version for this kernel */
  54	SEL_COMMIT_BOOLS, /* commit new boolean values */
  55	SEL_MLS,	/* return if MLS policy is enabled */
  56	SEL_DISABLE,	/* disable SELinux until next reboot */
  57	SEL_MEMBER,	/* compute polyinstantiation membership decision */
  58	SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
  59	SEL_COMPAT_NET,	/* whether to use old compat network packet controls */
  60	SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
  61	SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
  62	SEL_STATUS,	/* export current status using mmap() */
  63	SEL_POLICY,	/* allow userspace to read the in kernel policy */
  64	SEL_VALIDATE_TRANS, /* compute validatetrans decision */
  65	SEL_INO_NEXT,	/* The next inode number to use */
  66};
  67
  68struct selinux_fs_info {
  69	struct dentry *bool_dir;
  70	unsigned int bool_num;
  71	char **bool_pending_names;
  72	unsigned int *bool_pending_values;
  73	struct dentry *class_dir;
  74	unsigned long last_class_ino;
  75	bool policy_opened;
  76	struct dentry *policycap_dir;
  77	struct mutex mutex;
  78	unsigned long last_ino;
  79	struct selinux_state *state;
  80	struct super_block *sb;
  81};
  82
  83static int selinux_fs_info_create(struct super_block *sb)
  84{
  85	struct selinux_fs_info *fsi;
  86
  87	fsi = kzalloc(sizeof(*fsi), GFP_KERNEL);
  88	if (!fsi)
  89		return -ENOMEM;
  90
  91	mutex_init(&fsi->mutex);
  92	fsi->last_ino = SEL_INO_NEXT - 1;
  93	fsi->state = &selinux_state;
  94	fsi->sb = sb;
  95	sb->s_fs_info = fsi;
  96	return 0;
  97}
  98
  99static void selinux_fs_info_free(struct super_block *sb)
 100{
 101	struct selinux_fs_info *fsi = sb->s_fs_info;
 102	int i;
 103
 104	if (fsi) {
 105		for (i = 0; i < fsi->bool_num; i++)
 106			kfree(fsi->bool_pending_names[i]);
 107		kfree(fsi->bool_pending_names);
 108		kfree(fsi->bool_pending_values);
 109	}
 110	kfree(sb->s_fs_info);
 111	sb->s_fs_info = NULL;
 112}
 113
 114#define SEL_INITCON_INO_OFFSET		0x01000000
 115#define SEL_BOOL_INO_OFFSET		0x02000000
 116#define SEL_CLASS_INO_OFFSET		0x04000000
 117#define SEL_POLICYCAP_INO_OFFSET	0x08000000
 118#define SEL_INO_MASK			0x00ffffff
 119
 
 
 
 
 120#define TMPBUFLEN	12
 121static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 122				size_t count, loff_t *ppos)
 123{
 124	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 125	char tmpbuf[TMPBUFLEN];
 126	ssize_t length;
 127
 128	length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 129			   enforcing_enabled(fsi->state));
 130	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 131}
 132
 133#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 134static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 135				 size_t count, loff_t *ppos)
 136
 137{
 138	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 139	struct selinux_state *state = fsi->state;
 140	char *page = NULL;
 141	ssize_t length;
 142	int old_value, new_value;
 
 143
 144	if (count >= PAGE_SIZE)
 145		return -ENOMEM;
 146
 147	/* No partial writes. */
 148	if (*ppos != 0)
 149		return -EINVAL;
 150
 151	page = memdup_user_nul(buf, count);
 152	if (IS_ERR(page))
 153		return PTR_ERR(page);
 154
 155	length = -EINVAL;
 156	if (sscanf(page, "%d", &new_value) != 1)
 157		goto out;
 158
 159	new_value = !!new_value;
 160
 161	old_value = enforcing_enabled(state);
 162	if (new_value != old_value) {
 163		length = avc_has_perm(&selinux_state,
 164				      current_sid(), SECINITSID_SECURITY,
 165				      SECCLASS_SECURITY, SECURITY__SETENFORCE,
 166				      NULL);
 167		if (length)
 168			goto out;
 169		audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
 170			"enforcing=%d old_enforcing=%d auid=%u ses=%u"
 171			" enabled=%d old-enabled=%d lsm=selinux res=1",
 172			new_value, old_value,
 173			from_kuid(&init_user_ns, audit_get_loginuid(current)),
 174			audit_get_sessionid(current),
 175			selinux_enabled, selinux_enabled);
 176		enforcing_set(state, new_value);
 177		if (new_value)
 178			avc_ss_reset(state->avc, 0);
 179		selnl_notify_setenforce(new_value);
 180		selinux_status_update_setenforce(state, new_value);
 181		if (!new_value)
 182			call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
 
 
 183	}
 184	length = count;
 185out:
 186	kfree(page);
 187	return length;
 188}
 189#else
 190#define sel_write_enforce NULL
 191#endif
 192
 193static const struct file_operations sel_enforce_ops = {
 194	.read		= sel_read_enforce,
 195	.write		= sel_write_enforce,
 196	.llseek		= generic_file_llseek,
 197};
 198
 199static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 200					size_t count, loff_t *ppos)
 201{
 202	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 203	struct selinux_state *state = fsi->state;
 204	char tmpbuf[TMPBUFLEN];
 205	ssize_t length;
 206	ino_t ino = file_inode(filp)->i_ino;
 207	int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 208		security_get_reject_unknown(state) :
 209		!security_get_allow_unknown(state);
 210
 211	length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 212	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 213}
 214
 215static const struct file_operations sel_handle_unknown_ops = {
 216	.read		= sel_read_handle_unknown,
 217	.llseek		= generic_file_llseek,
 218};
 219
 220static int sel_open_handle_status(struct inode *inode, struct file *filp)
 221{
 222	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 223	struct page    *status = selinux_kernel_status_page(fsi->state);
 224
 225	if (!status)
 226		return -ENOMEM;
 227
 228	filp->private_data = status;
 229
 230	return 0;
 231}
 232
 233static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 234				      size_t count, loff_t *ppos)
 235{
 236	struct page    *status = filp->private_data;
 237
 238	BUG_ON(!status);
 239
 240	return simple_read_from_buffer(buf, count, ppos,
 241				       page_address(status),
 242				       sizeof(struct selinux_kernel_status));
 243}
 244
 245static int sel_mmap_handle_status(struct file *filp,
 246				  struct vm_area_struct *vma)
 247{
 248	struct page    *status = filp->private_data;
 249	unsigned long	size = vma->vm_end - vma->vm_start;
 250
 251	BUG_ON(!status);
 252
 253	/* only allows one page from the head */
 254	if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 255		return -EIO;
 256	/* disallow writable mapping */
 257	if (vma->vm_flags & VM_WRITE)
 258		return -EPERM;
 259	/* disallow mprotect() turns it into writable */
 260	vma->vm_flags &= ~VM_MAYWRITE;
 261
 262	return remap_pfn_range(vma, vma->vm_start,
 263			       page_to_pfn(status),
 264			       size, vma->vm_page_prot);
 265}
 266
 267static const struct file_operations sel_handle_status_ops = {
 268	.open		= sel_open_handle_status,
 269	.read		= sel_read_handle_status,
 270	.mmap		= sel_mmap_handle_status,
 271	.llseek		= generic_file_llseek,
 272};
 273
 274#ifdef CONFIG_SECURITY_SELINUX_DISABLE
 275static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 276				 size_t count, loff_t *ppos)
 277
 278{
 279	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 280	char *page;
 281	ssize_t length;
 282	int new_value;
 283	int enforcing;
 284
 285	if (count >= PAGE_SIZE)
 286		return -ENOMEM;
 287
 288	/* No partial writes. */
 289	if (*ppos != 0)
 290		return -EINVAL;
 291
 292	page = memdup_user_nul(buf, count);
 293	if (IS_ERR(page))
 294		return PTR_ERR(page);
 295
 296	length = -EINVAL;
 297	if (sscanf(page, "%d", &new_value) != 1)
 298		goto out;
 
 
 299
 300	if (new_value) {
 301		enforcing = enforcing_enabled(fsi->state);
 302		length = selinux_disable(fsi->state);
 303		if (length)
 304			goto out;
 305		audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
 306			"enforcing=%d old_enforcing=%d auid=%u ses=%u"
 307			" enabled=%d old-enabled=%d lsm=selinux res=1",
 308			enforcing, enforcing,
 309			from_kuid(&init_user_ns, audit_get_loginuid(current)),
 310			audit_get_sessionid(current), 0, 1);
 311	}
 312
 313	length = count;
 314out:
 315	kfree(page);
 316	return length;
 317}
 318#else
 319#define sel_write_disable NULL
 320#endif
 321
 322static const struct file_operations sel_disable_ops = {
 323	.write		= sel_write_disable,
 324	.llseek		= generic_file_llseek,
 325};
 326
 327static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 328				   size_t count, loff_t *ppos)
 329{
 330	char tmpbuf[TMPBUFLEN];
 331	ssize_t length;
 332
 333	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 334	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 335}
 336
 337static const struct file_operations sel_policyvers_ops = {
 338	.read		= sel_read_policyvers,
 339	.llseek		= generic_file_llseek,
 340};
 341
 342/* declaration for sel_write_load */
 343static int sel_make_bools(struct selinux_fs_info *fsi);
 344static int sel_make_classes(struct selinux_fs_info *fsi);
 345static int sel_make_policycap(struct selinux_fs_info *fsi);
 
 
 
 346
 347/* declaration for sel_make_class_dirs */
 348static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
 349			unsigned long *ino);
 350
 
 
 
 
 351static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 352				size_t count, loff_t *ppos)
 353{
 354	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 355	char tmpbuf[TMPBUFLEN];
 356	ssize_t length;
 357
 358	length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 359			   security_mls_enabled(fsi->state));
 360	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 361}
 362
 363static const struct file_operations sel_mls_ops = {
 364	.read		= sel_read_mls,
 365	.llseek		= generic_file_llseek,
 366};
 367
 368struct policy_load_memory {
 369	size_t len;
 370	void *data;
 371};
 372
 373static int sel_open_policy(struct inode *inode, struct file *filp)
 374{
 375	struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
 376	struct selinux_state *state = fsi->state;
 377	struct policy_load_memory *plm = NULL;
 378	int rc;
 379
 380	BUG_ON(filp->private_data);
 381
 382	mutex_lock(&fsi->mutex);
 383
 384	rc = avc_has_perm(&selinux_state,
 385			  current_sid(), SECINITSID_SECURITY,
 386			  SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
 387	if (rc)
 388		goto err;
 389
 390	rc = -EBUSY;
 391	if (fsi->policy_opened)
 392		goto err;
 393
 394	rc = -ENOMEM;
 395	plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 396	if (!plm)
 397		goto err;
 398
 399	if (i_size_read(inode) != security_policydb_len(state)) {
 
 
 
 
 400		inode_lock(inode);
 401		i_size_write(inode, security_policydb_len(state));
 402		inode_unlock(inode);
 403	}
 404
 405	rc = security_read_policy(state, &plm->data, &plm->len);
 406	if (rc)
 407		goto err;
 408
 409	fsi->policy_opened = 1;
 410
 411	filp->private_data = plm;
 412
 413	mutex_unlock(&fsi->mutex);
 414
 415	return 0;
 416err:
 417	mutex_unlock(&fsi->mutex);
 418
 419	if (plm)
 420		vfree(plm->data);
 421	kfree(plm);
 422	return rc;
 423}
 424
 425static int sel_release_policy(struct inode *inode, struct file *filp)
 426{
 427	struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
 428	struct policy_load_memory *plm = filp->private_data;
 429
 430	BUG_ON(!plm);
 431
 432	fsi->policy_opened = 0;
 433
 434	vfree(plm->data);
 435	kfree(plm);
 436
 437	return 0;
 438}
 439
 440static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 441			       size_t count, loff_t *ppos)
 442{
 443	struct policy_load_memory *plm = filp->private_data;
 444	int ret;
 445
 446	ret = avc_has_perm(&selinux_state,
 447			   current_sid(), SECINITSID_SECURITY,
 448			  SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
 449	if (ret)
 450		return ret;
 451
 452	return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 453}
 454
 455static vm_fault_t sel_mmap_policy_fault(struct vm_fault *vmf)
 456{
 457	struct policy_load_memory *plm = vmf->vma->vm_file->private_data;
 458	unsigned long offset;
 459	struct page *page;
 460
 461	if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 462		return VM_FAULT_SIGBUS;
 463
 464	offset = vmf->pgoff << PAGE_SHIFT;
 465	if (offset >= roundup(plm->len, PAGE_SIZE))
 466		return VM_FAULT_SIGBUS;
 467
 468	page = vmalloc_to_page(plm->data + offset);
 469	get_page(page);
 470
 471	vmf->page = page;
 472
 473	return 0;
 474}
 475
 476static const struct vm_operations_struct sel_mmap_policy_ops = {
 477	.fault = sel_mmap_policy_fault,
 478	.page_mkwrite = sel_mmap_policy_fault,
 479};
 480
 481static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 482{
 483	if (vma->vm_flags & VM_SHARED) {
 484		/* do not allow mprotect to make mapping writable */
 485		vma->vm_flags &= ~VM_MAYWRITE;
 486
 487		if (vma->vm_flags & VM_WRITE)
 488			return -EACCES;
 489	}
 490
 491	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 492	vma->vm_ops = &sel_mmap_policy_ops;
 493
 494	return 0;
 495}
 496
 497static const struct file_operations sel_policy_ops = {
 498	.open		= sel_open_policy,
 499	.read		= sel_read_policy,
 500	.mmap		= sel_mmap_policy,
 501	.release	= sel_release_policy,
 502	.llseek		= generic_file_llseek,
 503};
 504
 505static int sel_make_policy_nodes(struct selinux_fs_info *fsi)
 
 506{
 507	int ret;
 508
 509	ret = sel_make_bools(fsi);
 510	if (ret) {
 511		pr_err("SELinux: failed to load policy booleans\n");
 512		return ret;
 513	}
 
 514
 515	ret = sel_make_classes(fsi);
 516	if (ret) {
 517		pr_err("SELinux: failed to load policy classes\n");
 518		return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 519	}
 520
 521	ret = sel_make_policycap(fsi);
 522	if (ret) {
 523		pr_err("SELinux: failed to load policy capabilities\n");
 524		return ret;
 
 525	}
 526
 527	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 528}
 529
 530static ssize_t sel_write_load(struct file *file, const char __user *buf,
 531			      size_t count, loff_t *ppos)
 532
 533{
 534	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 
 535	ssize_t length;
 536	void *data = NULL;
 537
 538	mutex_lock(&fsi->mutex);
 539
 540	length = avc_has_perm(&selinux_state,
 541			      current_sid(), SECINITSID_SECURITY,
 542			      SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL);
 543	if (length)
 544		goto out;
 545
 546	/* No partial writes. */
 547	length = -EINVAL;
 548	if (*ppos != 0)
 549		goto out;
 550
 551	length = -EFBIG;
 552	if (count > 64 * 1024 * 1024)
 553		goto out;
 554
 555	length = -ENOMEM;
 556	data = vmalloc(count);
 557	if (!data)
 558		goto out;
 559
 560	length = -EFAULT;
 561	if (copy_from_user(data, buf, count) != 0)
 562		goto out;
 563
 564	length = security_load_policy(fsi->state, data, count);
 565	if (length) {
 566		pr_warn_ratelimited("SELinux: failed to load policy\n");
 567		goto out;
 568	}
 569
 570	length = sel_make_policy_nodes(fsi);
 571	if (length)
 572		goto out1;
 
 
 
 
 
 573
 574	length = count;
 575
 576out1:
 577	audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 578		"auid=%u ses=%u lsm=selinux res=1",
 579		from_kuid(&init_user_ns, audit_get_loginuid(current)),
 580		audit_get_sessionid(current));
 581out:
 582	mutex_unlock(&fsi->mutex);
 583	vfree(data);
 584	return length;
 585}
 586
 587static const struct file_operations sel_load_ops = {
 588	.write		= sel_write_load,
 589	.llseek		= generic_file_llseek,
 590};
 591
 592static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 593{
 594	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 595	struct selinux_state *state = fsi->state;
 596	char *canon = NULL;
 597	u32 sid, len;
 598	ssize_t length;
 599
 600	length = avc_has_perm(&selinux_state,
 601			      current_sid(), SECINITSID_SECURITY,
 602			      SECCLASS_SECURITY, SECURITY__CHECK_CONTEXT, NULL);
 603	if (length)
 604		goto out;
 605
 606	length = security_context_to_sid(state, buf, size, &sid, GFP_KERNEL);
 607	if (length)
 608		goto out;
 609
 610	length = security_sid_to_context(state, sid, &canon, &len);
 611	if (length)
 612		goto out;
 613
 614	length = -ERANGE;
 615	if (len > SIMPLE_TRANSACTION_LIMIT) {
 616		pr_err("SELinux: %s:  context size (%u) exceeds "
 617			"payload max\n", __func__, len);
 618		goto out;
 619	}
 620
 621	memcpy(buf, canon, len);
 622	length = len;
 623out:
 624	kfree(canon);
 625	return length;
 626}
 627
 628static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 629				     size_t count, loff_t *ppos)
 630{
 631	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
 632	char tmpbuf[TMPBUFLEN];
 633	ssize_t length;
 634
 635	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", fsi->state->checkreqprot);
 
 636	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 637}
 638
 639static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 640				      size_t count, loff_t *ppos)
 641{
 642	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 643	char *page;
 644	ssize_t length;
 645	unsigned int new_value;
 646
 647	length = avc_has_perm(&selinux_state,
 648			      current_sid(), SECINITSID_SECURITY,
 649			      SECCLASS_SECURITY, SECURITY__SETCHECKREQPROT,
 650			      NULL);
 651	if (length)
 652		return length;
 653
 654	if (count >= PAGE_SIZE)
 655		return -ENOMEM;
 656
 657	/* No partial writes. */
 658	if (*ppos != 0)
 659		return -EINVAL;
 660
 661	page = memdup_user_nul(buf, count);
 662	if (IS_ERR(page))
 663		return PTR_ERR(page);
 664
 665	length = -EINVAL;
 666	if (sscanf(page, "%u", &new_value) != 1)
 667		goto out;
 668
 669	fsi->state->checkreqprot = new_value ? 1 : 0;
 670	length = count;
 
 
 
 
 
 
 
 
 
 
 
 671out:
 672	kfree(page);
 673	return length;
 674}
 675static const struct file_operations sel_checkreqprot_ops = {
 676	.read		= sel_read_checkreqprot,
 677	.write		= sel_write_checkreqprot,
 678	.llseek		= generic_file_llseek,
 679};
 680
 681static ssize_t sel_write_validatetrans(struct file *file,
 682					const char __user *buf,
 683					size_t count, loff_t *ppos)
 684{
 685	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 686	struct selinux_state *state = fsi->state;
 687	char *oldcon = NULL, *newcon = NULL, *taskcon = NULL;
 688	char *req = NULL;
 689	u32 osid, nsid, tsid;
 690	u16 tclass;
 691	int rc;
 692
 693	rc = avc_has_perm(&selinux_state,
 694			  current_sid(), SECINITSID_SECURITY,
 695			  SECCLASS_SECURITY, SECURITY__VALIDATE_TRANS, NULL);
 696	if (rc)
 697		goto out;
 698
 699	rc = -ENOMEM;
 700	if (count >= PAGE_SIZE)
 701		goto out;
 702
 703	/* No partial writes. */
 704	rc = -EINVAL;
 705	if (*ppos != 0)
 706		goto out;
 707
 708	req = memdup_user_nul(buf, count);
 709	if (IS_ERR(req)) {
 710		rc = PTR_ERR(req);
 711		req = NULL;
 712		goto out;
 713	}
 714
 715	rc = -ENOMEM;
 716	oldcon = kzalloc(count + 1, GFP_KERNEL);
 717	if (!oldcon)
 718		goto out;
 719
 720	newcon = kzalloc(count + 1, GFP_KERNEL);
 721	if (!newcon)
 722		goto out;
 723
 724	taskcon = kzalloc(count + 1, GFP_KERNEL);
 725	if (!taskcon)
 726		goto out;
 727
 728	rc = -EINVAL;
 729	if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4)
 730		goto out;
 731
 732	rc = security_context_str_to_sid(state, oldcon, &osid, GFP_KERNEL);
 733	if (rc)
 734		goto out;
 735
 736	rc = security_context_str_to_sid(state, newcon, &nsid, GFP_KERNEL);
 737	if (rc)
 738		goto out;
 739
 740	rc = security_context_str_to_sid(state, taskcon, &tsid, GFP_KERNEL);
 741	if (rc)
 742		goto out;
 743
 744	rc = security_validate_transition_user(state, osid, nsid, tsid, tclass);
 745	if (!rc)
 746		rc = count;
 747out:
 748	kfree(req);
 749	kfree(oldcon);
 750	kfree(newcon);
 751	kfree(taskcon);
 752	return rc;
 753}
 754
 755static const struct file_operations sel_transition_ops = {
 756	.write		= sel_write_validatetrans,
 757	.llseek		= generic_file_llseek,
 758};
 759
 760/*
 761 * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 762 */
 763static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 764static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 765static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 766static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 767static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 768
 769static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
 770	[SEL_ACCESS] = sel_write_access,
 771	[SEL_CREATE] = sel_write_create,
 772	[SEL_RELABEL] = sel_write_relabel,
 773	[SEL_USER] = sel_write_user,
 774	[SEL_MEMBER] = sel_write_member,
 775	[SEL_CONTEXT] = sel_write_context,
 776};
 777
 778static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 779{
 780	ino_t ino = file_inode(file)->i_ino;
 781	char *data;
 782	ssize_t rv;
 783
 784	if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 785		return -EINVAL;
 786
 787	data = simple_transaction_get(file, buf, size);
 788	if (IS_ERR(data))
 789		return PTR_ERR(data);
 790
 791	rv = write_op[ino](file, data, size);
 792	if (rv > 0) {
 793		simple_transaction_set(file, rv);
 794		rv = size;
 795	}
 796	return rv;
 797}
 798
 799static const struct file_operations transaction_ops = {
 800	.write		= selinux_transaction_write,
 801	.read		= simple_transaction_read,
 802	.release	= simple_transaction_release,
 803	.llseek		= generic_file_llseek,
 804};
 805
 806/*
 807 * payload - write methods
 808 * If the method has a response, the response should be put in buf,
 809 * and the length returned.  Otherwise return 0 or and -error.
 810 */
 811
 812static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 813{
 814	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 815	struct selinux_state *state = fsi->state;
 816	char *scon = NULL, *tcon = NULL;
 817	u32 ssid, tsid;
 818	u16 tclass;
 819	struct av_decision avd;
 820	ssize_t length;
 821
 822	length = avc_has_perm(&selinux_state,
 823			      current_sid(), SECINITSID_SECURITY,
 824			      SECCLASS_SECURITY, SECURITY__COMPUTE_AV, NULL);
 825	if (length)
 826		goto out;
 827
 828	length = -ENOMEM;
 829	scon = kzalloc(size + 1, GFP_KERNEL);
 830	if (!scon)
 831		goto out;
 832
 833	length = -ENOMEM;
 834	tcon = kzalloc(size + 1, GFP_KERNEL);
 835	if (!tcon)
 836		goto out;
 837
 838	length = -EINVAL;
 839	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 840		goto out;
 841
 842	length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
 843	if (length)
 844		goto out;
 845
 846	length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
 847	if (length)
 848		goto out;
 849
 850	security_compute_av_user(state, ssid, tsid, tclass, &avd);
 851
 852	length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 853			  "%x %x %x %x %u %x",
 854			  avd.allowed, 0xffffffff,
 855			  avd.auditallow, avd.auditdeny,
 856			  avd.seqno, avd.flags);
 857out:
 858	kfree(tcon);
 859	kfree(scon);
 860	return length;
 861}
 862
 863static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 864{
 865	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 866	struct selinux_state *state = fsi->state;
 867	char *scon = NULL, *tcon = NULL;
 868	char *namebuf = NULL, *objname = NULL;
 869	u32 ssid, tsid, newsid;
 870	u16 tclass;
 871	ssize_t length;
 872	char *newcon = NULL;
 873	u32 len;
 874	int nargs;
 875
 876	length = avc_has_perm(&selinux_state,
 877			      current_sid(), SECINITSID_SECURITY,
 878			      SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE,
 879			      NULL);
 880	if (length)
 881		goto out;
 882
 883	length = -ENOMEM;
 884	scon = kzalloc(size + 1, GFP_KERNEL);
 885	if (!scon)
 886		goto out;
 887
 888	length = -ENOMEM;
 889	tcon = kzalloc(size + 1, GFP_KERNEL);
 890	if (!tcon)
 891		goto out;
 892
 893	length = -ENOMEM;
 894	namebuf = kzalloc(size + 1, GFP_KERNEL);
 895	if (!namebuf)
 896		goto out;
 897
 898	length = -EINVAL;
 899	nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 900	if (nargs < 3 || nargs > 4)
 901		goto out;
 902	if (nargs == 4) {
 903		/*
 904		 * If and when the name of new object to be queried contains
 905		 * either whitespace or multibyte characters, they shall be
 906		 * encoded based on the percentage-encoding rule.
 907		 * If not encoded, the sscanf logic picks up only left-half
 908		 * of the supplied name; splitted by a whitespace unexpectedly.
 909		 */
 910		char   *r, *w;
 911		int     c1, c2;
 912
 913		r = w = namebuf;
 914		do {
 915			c1 = *r++;
 916			if (c1 == '+')
 917				c1 = ' ';
 918			else if (c1 == '%') {
 919				c1 = hex_to_bin(*r++);
 920				if (c1 < 0)
 921					goto out;
 922				c2 = hex_to_bin(*r++);
 923				if (c2 < 0)
 924					goto out;
 925				c1 = (c1 << 4) | c2;
 926			}
 927			*w++ = c1;
 928		} while (c1 != '\0');
 929
 930		objname = namebuf;
 931	}
 932
 933	length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
 934	if (length)
 935		goto out;
 936
 937	length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
 938	if (length)
 939		goto out;
 940
 941	length = security_transition_sid_user(state, ssid, tsid, tclass,
 942					      objname, &newsid);
 943	if (length)
 944		goto out;
 945
 946	length = security_sid_to_context(state, newsid, &newcon, &len);
 947	if (length)
 948		goto out;
 949
 950	length = -ERANGE;
 951	if (len > SIMPLE_TRANSACTION_LIMIT) {
 952		pr_err("SELinux: %s:  context size (%u) exceeds "
 953			"payload max\n", __func__, len);
 954		goto out;
 955	}
 956
 957	memcpy(buf, newcon, len);
 958	length = len;
 959out:
 960	kfree(newcon);
 961	kfree(namebuf);
 962	kfree(tcon);
 963	kfree(scon);
 964	return length;
 965}
 966
 967static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 968{
 969	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
 970	struct selinux_state *state = fsi->state;
 971	char *scon = NULL, *tcon = NULL;
 972	u32 ssid, tsid, newsid;
 973	u16 tclass;
 974	ssize_t length;
 975	char *newcon = NULL;
 976	u32 len;
 977
 978	length = avc_has_perm(&selinux_state,
 979			      current_sid(), SECINITSID_SECURITY,
 980			      SECCLASS_SECURITY, SECURITY__COMPUTE_RELABEL,
 981			      NULL);
 982	if (length)
 983		goto out;
 984
 985	length = -ENOMEM;
 986	scon = kzalloc(size + 1, GFP_KERNEL);
 987	if (!scon)
 988		goto out;
 989
 990	length = -ENOMEM;
 991	tcon = kzalloc(size + 1, GFP_KERNEL);
 992	if (!tcon)
 993		goto out;
 994
 995	length = -EINVAL;
 996	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 997		goto out;
 998
 999	length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
1000	if (length)
1001		goto out;
1002
1003	length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
1004	if (length)
1005		goto out;
1006
1007	length = security_change_sid(state, ssid, tsid, tclass, &newsid);
1008	if (length)
1009		goto out;
1010
1011	length = security_sid_to_context(state, newsid, &newcon, &len);
1012	if (length)
1013		goto out;
1014
1015	length = -ERANGE;
1016	if (len > SIMPLE_TRANSACTION_LIMIT)
1017		goto out;
1018
1019	memcpy(buf, newcon, len);
1020	length = len;
1021out:
1022	kfree(newcon);
1023	kfree(tcon);
1024	kfree(scon);
1025	return length;
1026}
1027
1028static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
1029{
1030	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1031	struct selinux_state *state = fsi->state;
1032	char *con = NULL, *user = NULL, *ptr;
1033	u32 sid, *sids = NULL;
1034	ssize_t length;
1035	char *newcon;
1036	int i, rc;
1037	u32 len, nsids;
1038
1039	length = avc_has_perm(&selinux_state,
1040			      current_sid(), SECINITSID_SECURITY,
1041			      SECCLASS_SECURITY, SECURITY__COMPUTE_USER,
1042			      NULL);
1043	if (length)
1044		goto out;
1045
1046	length = -ENOMEM;
1047	con = kzalloc(size + 1, GFP_KERNEL);
1048	if (!con)
1049		goto out;
1050
1051	length = -ENOMEM;
1052	user = kzalloc(size + 1, GFP_KERNEL);
1053	if (!user)
1054		goto out;
1055
1056	length = -EINVAL;
1057	if (sscanf(buf, "%s %s", con, user) != 2)
1058		goto out;
1059
1060	length = security_context_str_to_sid(state, con, &sid, GFP_KERNEL);
1061	if (length)
1062		goto out;
1063
1064	length = security_get_user_sids(state, sid, user, &sids, &nsids);
1065	if (length)
1066		goto out;
1067
1068	length = sprintf(buf, "%u", nsids) + 1;
1069	ptr = buf + length;
1070	for (i = 0; i < nsids; i++) {
1071		rc = security_sid_to_context(state, sids[i], &newcon, &len);
1072		if (rc) {
1073			length = rc;
1074			goto out;
1075		}
1076		if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
1077			kfree(newcon);
1078			length = -ERANGE;
1079			goto out;
1080		}
1081		memcpy(ptr, newcon, len);
1082		kfree(newcon);
1083		ptr += len;
1084		length += len;
1085	}
1086out:
1087	kfree(sids);
1088	kfree(user);
1089	kfree(con);
1090	return length;
1091}
1092
1093static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
1094{
1095	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1096	struct selinux_state *state = fsi->state;
1097	char *scon = NULL, *tcon = NULL;
1098	u32 ssid, tsid, newsid;
1099	u16 tclass;
1100	ssize_t length;
1101	char *newcon = NULL;
1102	u32 len;
1103
1104	length = avc_has_perm(&selinux_state,
1105			      current_sid(), SECINITSID_SECURITY,
1106			      SECCLASS_SECURITY, SECURITY__COMPUTE_MEMBER,
1107			      NULL);
1108	if (length)
1109		goto out;
1110
1111	length = -ENOMEM;
1112	scon = kzalloc(size + 1, GFP_KERNEL);
1113	if (!scon)
1114		goto out;
1115
1116	length = -ENOMEM;
1117	tcon = kzalloc(size + 1, GFP_KERNEL);
1118	if (!tcon)
1119		goto out;
1120
1121	length = -EINVAL;
1122	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1123		goto out;
1124
1125	length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
1126	if (length)
1127		goto out;
1128
1129	length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
1130	if (length)
1131		goto out;
1132
1133	length = security_member_sid(state, ssid, tsid, tclass, &newsid);
1134	if (length)
1135		goto out;
1136
1137	length = security_sid_to_context(state, newsid, &newcon, &len);
1138	if (length)
1139		goto out;
1140
1141	length = -ERANGE;
1142	if (len > SIMPLE_TRANSACTION_LIMIT) {
1143		pr_err("SELinux: %s:  context size (%u) exceeds "
1144			"payload max\n", __func__, len);
1145		goto out;
1146	}
1147
1148	memcpy(buf, newcon, len);
1149	length = len;
1150out:
1151	kfree(newcon);
1152	kfree(tcon);
1153	kfree(scon);
1154	return length;
1155}
1156
1157static struct inode *sel_make_inode(struct super_block *sb, int mode)
1158{
1159	struct inode *ret = new_inode(sb);
1160
1161	if (ret) {
1162		ret->i_mode = mode;
1163		ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
1164	}
1165	return ret;
1166}
1167
1168static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1169			     size_t count, loff_t *ppos)
1170{
1171	struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1172	char *page = NULL;
1173	ssize_t length;
1174	ssize_t ret;
1175	int cur_enforcing;
1176	unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1177	const char *name = filep->f_path.dentry->d_name.name;
1178
1179	mutex_lock(&fsi->mutex);
1180
1181	ret = -EINVAL;
1182	if (index >= fsi->bool_num || strcmp(name,
1183					     fsi->bool_pending_names[index]))
1184		goto out_unlock;
1185
1186	ret = -ENOMEM;
1187	page = (char *)get_zeroed_page(GFP_KERNEL);
1188	if (!page)
1189		goto out_unlock;
1190
1191	cur_enforcing = security_get_bool_value(fsi->state, index);
1192	if (cur_enforcing < 0) {
1193		ret = cur_enforcing;
1194		goto out_unlock;
1195	}
1196	length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1197			  fsi->bool_pending_values[index]);
1198	mutex_unlock(&fsi->mutex);
1199	ret = simple_read_from_buffer(buf, count, ppos, page, length);
1200out_free:
1201	free_page((unsigned long)page);
1202	return ret;
1203
1204out_unlock:
1205	mutex_unlock(&fsi->mutex);
1206	goto out_free;
1207}
1208
1209static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1210			      size_t count, loff_t *ppos)
1211{
1212	struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1213	char *page = NULL;
1214	ssize_t length;
1215	int new_value;
1216	unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1217	const char *name = filep->f_path.dentry->d_name.name;
1218
1219	if (count >= PAGE_SIZE)
1220		return -ENOMEM;
1221
1222	/* No partial writes. */
1223	if (*ppos != 0)
1224		return -EINVAL;
1225
1226	page = memdup_user_nul(buf, count);
1227	if (IS_ERR(page))
1228		return PTR_ERR(page);
1229
1230	mutex_lock(&fsi->mutex);
1231
1232	length = avc_has_perm(&selinux_state,
1233			      current_sid(), SECINITSID_SECURITY,
1234			      SECCLASS_SECURITY, SECURITY__SETBOOL,
1235			      NULL);
1236	if (length)
1237		goto out;
1238
1239	length = -EINVAL;
1240	if (index >= fsi->bool_num || strcmp(name,
1241					     fsi->bool_pending_names[index]))
1242		goto out;
1243
1244	length = -EINVAL;
1245	if (sscanf(page, "%d", &new_value) != 1)
1246		goto out;
1247
1248	if (new_value)
1249		new_value = 1;
1250
1251	fsi->bool_pending_values[index] = new_value;
1252	length = count;
1253
1254out:
1255	mutex_unlock(&fsi->mutex);
1256	kfree(page);
1257	return length;
1258}
1259
1260static const struct file_operations sel_bool_ops = {
1261	.read		= sel_read_bool,
1262	.write		= sel_write_bool,
1263	.llseek		= generic_file_llseek,
1264};
1265
1266static ssize_t sel_commit_bools_write(struct file *filep,
1267				      const char __user *buf,
1268				      size_t count, loff_t *ppos)
1269{
1270	struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1271	char *page = NULL;
1272	ssize_t length;
1273	int new_value;
1274
1275	if (count >= PAGE_SIZE)
1276		return -ENOMEM;
1277
1278	/* No partial writes. */
1279	if (*ppos != 0)
1280		return -EINVAL;
1281
1282	page = memdup_user_nul(buf, count);
1283	if (IS_ERR(page))
1284		return PTR_ERR(page);
1285
1286	mutex_lock(&fsi->mutex);
1287
1288	length = avc_has_perm(&selinux_state,
1289			      current_sid(), SECINITSID_SECURITY,
1290			      SECCLASS_SECURITY, SECURITY__SETBOOL,
1291			      NULL);
1292	if (length)
1293		goto out;
1294
1295	length = -EINVAL;
1296	if (sscanf(page, "%d", &new_value) != 1)
1297		goto out;
1298
1299	length = 0;
1300	if (new_value && fsi->bool_pending_values)
1301		length = security_set_bools(fsi->state, fsi->bool_num,
1302					    fsi->bool_pending_values);
1303
1304	if (!length)
1305		length = count;
1306
1307out:
1308	mutex_unlock(&fsi->mutex);
1309	kfree(page);
1310	return length;
1311}
1312
1313static const struct file_operations sel_commit_bools_ops = {
1314	.write		= sel_commit_bools_write,
1315	.llseek		= generic_file_llseek,
1316};
1317
1318static void sel_remove_entries(struct dentry *de)
 
 
1319{
1320	d_genocide(de);
1321	shrink_dcache_parent(de);
1322}
1323
1324#define BOOL_DIR_NAME "booleans"
1325
1326static int sel_make_bools(struct selinux_fs_info *fsi)
1327{
1328	int i, ret;
1329	ssize_t len;
1330	struct dentry *dentry = NULL;
1331	struct dentry *dir = fsi->bool_dir;
1332	struct inode *inode = NULL;
1333	struct inode_security_struct *isec;
1334	char **names = NULL, *page;
1335	int num;
1336	int *values = NULL;
1337	u32 sid;
1338
1339	/* remove any existing files */
1340	for (i = 0; i < fsi->bool_num; i++)
1341		kfree(fsi->bool_pending_names[i]);
1342	kfree(fsi->bool_pending_names);
1343	kfree(fsi->bool_pending_values);
1344	fsi->bool_num = 0;
1345	fsi->bool_pending_names = NULL;
1346	fsi->bool_pending_values = NULL;
1347
1348	sel_remove_entries(dir);
1349
1350	ret = -ENOMEM;
1351	page = (char *)get_zeroed_page(GFP_KERNEL);
1352	if (!page)
1353		goto out;
1354
1355	ret = security_get_bools(fsi->state, &num, &names, &values);
1356	if (ret)
1357		goto out;
1358
1359	for (i = 0; i < num; i++) {
1360		ret = -ENOMEM;
1361		dentry = d_alloc_name(dir, names[i]);
1362		if (!dentry)
1363			goto out;
1364
1365		ret = -ENOMEM;
1366		inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1367		if (!inode) {
1368			dput(dentry);
1369			goto out;
1370		}
1371
1372		ret = -ENAMETOOLONG;
1373		len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1374		if (len >= PAGE_SIZE) {
 
 
 
 
 
 
 
 
 
 
 
1375			dput(dentry);
1376			iput(inode);
1377			goto out;
1378		}
1379
1380		isec = selinux_inode(inode);
1381		ret = security_genfs_sid(fsi->state, "selinuxfs", page,
1382					 SECCLASS_FILE, &sid);
1383		if (ret) {
1384			pr_warn_ratelimited("SELinux: no sid found, defaulting to security isid for %s\n",
1385					   page);
1386			sid = SECINITSID_SECURITY;
1387		}
1388
1389		isec->sid = sid;
1390		isec->initialized = LABEL_INITIALIZED;
1391		inode->i_fop = &sel_bool_ops;
1392		inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1393		d_add(dentry, inode);
1394	}
1395	fsi->bool_num = num;
1396	fsi->bool_pending_names = names;
1397	fsi->bool_pending_values = values;
1398
1399	free_page((unsigned long)page);
1400	return 0;
1401out:
1402	free_page((unsigned long)page);
1403
1404	if (names) {
1405		for (i = 0; i < num; i++)
1406			kfree(names[i]);
1407		kfree(names);
1408	}
1409	kfree(values);
1410	sel_remove_entries(dir);
1411
1412	return ret;
1413}
1414
1415static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1416					    size_t count, loff_t *ppos)
1417{
1418	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1419	struct selinux_state *state = fsi->state;
1420	char tmpbuf[TMPBUFLEN];
1421	ssize_t length;
1422
1423	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1424			   avc_get_cache_threshold(state->avc));
1425	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1426}
1427
1428static ssize_t sel_write_avc_cache_threshold(struct file *file,
1429					     const char __user *buf,
1430					     size_t count, loff_t *ppos)
1431
1432{
1433	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1434	struct selinux_state *state = fsi->state;
1435	char *page;
1436	ssize_t ret;
1437	unsigned int new_value;
1438
1439	ret = avc_has_perm(&selinux_state,
1440			   current_sid(), SECINITSID_SECURITY,
1441			   SECCLASS_SECURITY, SECURITY__SETSECPARAM,
1442			   NULL);
1443	if (ret)
1444		return ret;
1445
1446	if (count >= PAGE_SIZE)
1447		return -ENOMEM;
1448
1449	/* No partial writes. */
1450	if (*ppos != 0)
1451		return -EINVAL;
1452
1453	page = memdup_user_nul(buf, count);
1454	if (IS_ERR(page))
1455		return PTR_ERR(page);
1456
1457	ret = -EINVAL;
1458	if (sscanf(page, "%u", &new_value) != 1)
1459		goto out;
1460
1461	avc_set_cache_threshold(state->avc, new_value);
1462
1463	ret = count;
1464out:
1465	kfree(page);
1466	return ret;
1467}
1468
1469static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1470				       size_t count, loff_t *ppos)
1471{
1472	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1473	struct selinux_state *state = fsi->state;
1474	char *page;
1475	ssize_t length;
1476
1477	page = (char *)__get_free_page(GFP_KERNEL);
1478	if (!page)
1479		return -ENOMEM;
1480
1481	length = avc_get_hash_stats(state->avc, page);
1482	if (length >= 0)
1483		length = simple_read_from_buffer(buf, count, ppos, page, length);
1484	free_page((unsigned long)page);
1485
1486	return length;
1487}
1488
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1489static const struct file_operations sel_avc_cache_threshold_ops = {
1490	.read		= sel_read_avc_cache_threshold,
1491	.write		= sel_write_avc_cache_threshold,
1492	.llseek		= generic_file_llseek,
1493};
1494
1495static const struct file_operations sel_avc_hash_stats_ops = {
1496	.read		= sel_read_avc_hash_stats,
1497	.llseek		= generic_file_llseek,
1498};
1499
1500#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1501static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1502{
1503	int cpu;
1504
1505	for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1506		if (!cpu_possible(cpu))
1507			continue;
1508		*idx = cpu + 1;
1509		return &per_cpu(avc_cache_stats, cpu);
1510	}
 
1511	return NULL;
1512}
1513
1514static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1515{
1516	loff_t n = *pos - 1;
1517
1518	if (*pos == 0)
1519		return SEQ_START_TOKEN;
1520
1521	return sel_avc_get_stat_idx(&n);
1522}
1523
1524static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1525{
1526	return sel_avc_get_stat_idx(pos);
1527}
1528
1529static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1530{
1531	struct avc_cache_stats *st = v;
1532
1533	if (v == SEQ_START_TOKEN) {
1534		seq_puts(seq,
1535			 "lookups hits misses allocations reclaims frees\n");
1536	} else {
1537		unsigned int lookups = st->lookups;
1538		unsigned int misses = st->misses;
1539		unsigned int hits = lookups - misses;
1540		seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1541			   hits, misses, st->allocations,
1542			   st->reclaims, st->frees);
1543	}
1544	return 0;
1545}
1546
1547static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1548{ }
1549
1550static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1551	.start		= sel_avc_stats_seq_start,
1552	.next		= sel_avc_stats_seq_next,
1553	.show		= sel_avc_stats_seq_show,
1554	.stop		= sel_avc_stats_seq_stop,
1555};
1556
1557static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1558{
1559	return seq_open(file, &sel_avc_cache_stats_seq_ops);
1560}
1561
1562static const struct file_operations sel_avc_cache_stats_ops = {
1563	.open		= sel_open_avc_cache_stats,
1564	.read		= seq_read,
1565	.llseek		= seq_lseek,
1566	.release	= seq_release,
1567};
1568#endif
1569
1570static int sel_make_avc_files(struct dentry *dir)
1571{
1572	struct super_block *sb = dir->d_sb;
1573	struct selinux_fs_info *fsi = sb->s_fs_info;
1574	int i;
1575	static const struct tree_descr files[] = {
1576		{ "cache_threshold",
1577		  &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1578		{ "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1579#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1580		{ "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1581#endif
1582	};
1583
1584	for (i = 0; i < ARRAY_SIZE(files); i++) {
1585		struct inode *inode;
1586		struct dentry *dentry;
1587
1588		dentry = d_alloc_name(dir, files[i].name);
1589		if (!dentry)
1590			return -ENOMEM;
1591
1592		inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1593		if (!inode) {
1594			dput(dentry);
1595			return -ENOMEM;
1596		}
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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1606static 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
1624static const struct file_operations sel_initcon_ops = {
1625	.read		= sel_read_initcon,
1626	.llseek		= generic_file_llseek,
1627};
1628
1629static 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			dput(dentry);
1643			return -ENOMEM;
1644		}
1645
1646		inode->i_fop = &sel_initcon_ops;
1647		inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1648		d_add(dentry, inode);
1649	}
1650
1651	return 0;
1652}
1653
1654static inline unsigned long sel_class_to_ino(u16 class)
1655{
1656	return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1657}
1658
1659static inline u16 sel_ino_to_class(unsigned long ino)
1660{
1661	return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1662}
1663
1664static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1665{
1666	return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1667}
1668
1669static inline u32 sel_ino_to_perm(unsigned long ino)
1670{
1671	return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1672}
1673
1674static ssize_t sel_read_class(struct file *file, char __user *buf,
1675				size_t count, loff_t *ppos)
1676{
1677	unsigned long ino = file_inode(file)->i_ino;
1678	char res[TMPBUFLEN];
1679	ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1680	return simple_read_from_buffer(buf, count, ppos, res, len);
1681}
1682
1683static const struct file_operations sel_class_ops = {
1684	.read		= sel_read_class,
1685	.llseek		= generic_file_llseek,
1686};
1687
1688static ssize_t sel_read_perm(struct file *file, char __user *buf,
1689				size_t count, loff_t *ppos)
1690{
1691	unsigned long ino = file_inode(file)->i_ino;
1692	char res[TMPBUFLEN];
1693	ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1694	return simple_read_from_buffer(buf, count, ppos, res, len);
1695}
1696
1697static const struct file_operations sel_perm_ops = {
1698	.read		= sel_read_perm,
1699	.llseek		= generic_file_llseek,
1700};
1701
1702static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1703				  size_t count, loff_t *ppos)
1704{
1705	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1706	int value;
1707	char tmpbuf[TMPBUFLEN];
1708	ssize_t length;
1709	unsigned long i_ino = file_inode(file)->i_ino;
1710
1711	value = security_policycap_supported(fsi->state, i_ino & SEL_INO_MASK);
1712	length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1713
1714	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1715}
1716
1717static const struct file_operations sel_policycap_ops = {
1718	.read		= sel_read_policycap,
1719	.llseek		= generic_file_llseek,
1720};
1721
1722static int sel_make_perm_files(char *objclass, int classvalue,
1723				struct dentry *dir)
 
1724{
1725	struct selinux_fs_info *fsi = dir->d_sb->s_fs_info;
1726	int i, rc, nperms;
1727	char **perms;
1728
1729	rc = security_get_permissions(fsi->state, objclass, &perms, &nperms);
1730	if (rc)
1731		return rc;
1732
1733	for (i = 0; i < nperms; i++) {
1734		struct inode *inode;
1735		struct dentry *dentry;
1736
1737		rc = -ENOMEM;
1738		dentry = d_alloc_name(dir, perms[i]);
1739		if (!dentry)
1740			goto out;
1741
1742		rc = -ENOMEM;
1743		inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1744		if (!inode) {
1745			dput(dentry);
1746			goto out;
1747		}
1748
1749		inode->i_fop = &sel_perm_ops;
1750		/* i+1 since perm values are 1-indexed */
1751		inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1752		d_add(dentry, inode);
1753	}
1754	rc = 0;
1755out:
1756	for (i = 0; i < nperms; i++)
1757		kfree(perms[i]);
1758	kfree(perms);
1759	return rc;
1760}
1761
1762static int sel_make_class_dir_entries(char *classname, int index,
1763					struct dentry *dir)
 
1764{
1765	struct super_block *sb = dir->d_sb;
1766	struct selinux_fs_info *fsi = sb->s_fs_info;
1767	struct dentry *dentry = NULL;
1768	struct inode *inode = NULL;
1769	int rc;
1770
1771	dentry = d_alloc_name(dir, "index");
1772	if (!dentry)
1773		return -ENOMEM;
1774
1775	inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1776	if (!inode) {
1777		dput(dentry);
1778		return -ENOMEM;
1779	}
1780
1781	inode->i_fop = &sel_class_ops;
1782	inode->i_ino = sel_class_to_ino(index);
1783	d_add(dentry, inode);
1784
1785	dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino);
1786	if (IS_ERR(dentry))
1787		return PTR_ERR(dentry);
1788
1789	rc = sel_make_perm_files(classname, index, dentry);
1790
1791	return rc;
1792}
1793
1794static int sel_make_classes(struct selinux_fs_info *fsi)
 
 
1795{
1796
1797	int rc, nclasses, i;
1798	char **classes;
1799
1800	/* delete any existing entries */
1801	sel_remove_entries(fsi->class_dir);
1802
1803	rc = security_get_classes(fsi->state, &classes, &nclasses);
1804	if (rc)
1805		return rc;
1806
1807	/* +2 since classes are 1-indexed */
1808	fsi->last_class_ino = sel_class_to_ino(nclasses + 2);
1809
1810	for (i = 0; i < nclasses; i++) {
1811		struct dentry *class_name_dir;
1812
1813		class_name_dir = sel_make_dir(fsi->class_dir, classes[i],
1814					      &fsi->last_class_ino);
1815		if (IS_ERR(class_name_dir)) {
1816			rc = PTR_ERR(class_name_dir);
1817			goto out;
1818		}
1819
1820		/* i+1 since class values are 1-indexed */
1821		rc = sel_make_class_dir_entries(classes[i], i + 1,
1822				class_name_dir);
1823		if (rc)
1824			goto out;
1825	}
1826	rc = 0;
1827out:
1828	for (i = 0; i < nclasses; i++)
1829		kfree(classes[i]);
1830	kfree(classes);
1831	return rc;
1832}
1833
1834static int sel_make_policycap(struct selinux_fs_info *fsi)
1835{
1836	unsigned int iter;
1837	struct dentry *dentry = NULL;
1838	struct inode *inode = NULL;
1839
1840	sel_remove_entries(fsi->policycap_dir);
1841
1842	for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1843		if (iter < ARRAY_SIZE(selinux_policycap_names))
1844			dentry = d_alloc_name(fsi->policycap_dir,
1845					      selinux_policycap_names[iter]);
1846		else
1847			dentry = d_alloc_name(fsi->policycap_dir, "unknown");
1848
1849		if (dentry == NULL)
1850			return -ENOMEM;
1851
1852		inode = sel_make_inode(fsi->sb, S_IFREG | 0444);
1853		if (inode == NULL) {
1854			dput(dentry);
1855			return -ENOMEM;
1856		}
1857
1858		inode->i_fop = &sel_policycap_ops;
1859		inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1860		d_add(dentry, inode);
1861	}
1862
1863	return 0;
1864}
1865
1866static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1867			unsigned long *ino)
1868{
1869	struct dentry *dentry = d_alloc_name(dir, name);
1870	struct inode *inode;
1871
1872	if (!dentry)
1873		return ERR_PTR(-ENOMEM);
1874
1875	inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1876	if (!inode) {
1877		dput(dentry);
1878		return ERR_PTR(-ENOMEM);
1879	}
1880
1881	inode->i_op = &simple_dir_inode_operations;
1882	inode->i_fop = &simple_dir_operations;
1883	inode->i_ino = ++(*ino);
1884	/* directory inodes start off with i_nlink == 2 (for "." entry) */
1885	inc_nlink(inode);
1886	d_add(dentry, inode);
1887	/* bump link count on parent directory, too */
1888	inc_nlink(d_inode(dir));
1889
1890	return dentry;
1891}
1892
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1893#define NULL_FILE_NAME "null"
1894
1895static int sel_fill_super(struct super_block *sb, struct fs_context *fc)
1896{
1897	struct selinux_fs_info *fsi;
1898	int ret;
1899	struct dentry *dentry;
1900	struct inode *inode;
1901	struct inode_security_struct *isec;
1902
1903	static const struct tree_descr selinux_files[] = {
1904		[SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1905		[SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1906		[SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1907		[SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1908		[SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1909		[SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1910		[SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1911		[SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1912		[SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1913		[SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1914		[SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1915		[SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1916		[SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1917		[SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1918		[SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1919		[SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1920		[SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1921		[SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops,
1922					S_IWUGO},
1923		/* last one */ {""}
1924	};
1925
1926	ret = selinux_fs_info_create(sb);
1927	if (ret)
1928		goto err;
1929
1930	ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1931	if (ret)
1932		goto err;
1933
1934	fsi = sb->s_fs_info;
1935	fsi->bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &fsi->last_ino);
1936	if (IS_ERR(fsi->bool_dir)) {
1937		ret = PTR_ERR(fsi->bool_dir);
1938		fsi->bool_dir = NULL;
1939		goto err;
1940	}
1941
1942	ret = -ENOMEM;
1943	dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1944	if (!dentry)
1945		goto err;
1946
1947	ret = -ENOMEM;
1948	inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1949	if (!inode) {
1950		dput(dentry);
1951		goto err;
1952	}
1953
1954	inode->i_ino = ++fsi->last_ino;
1955	isec = selinux_inode(inode);
1956	isec->sid = SECINITSID_DEVNULL;
1957	isec->sclass = SECCLASS_CHR_FILE;
1958	isec->initialized = LABEL_INITIALIZED;
1959
1960	init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1961	d_add(dentry, inode);
1962
1963	dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino);
1964	if (IS_ERR(dentry)) {
1965		ret = PTR_ERR(dentry);
1966		goto err;
1967	}
1968
1969	ret = sel_make_avc_files(dentry);
1970	if (ret)
1971		goto err;
1972
 
 
 
 
 
 
 
 
 
 
1973	dentry = sel_make_dir(sb->s_root, "initial_contexts", &fsi->last_ino);
1974	if (IS_ERR(dentry)) {
1975		ret = PTR_ERR(dentry);
1976		goto err;
1977	}
1978
1979	ret = sel_make_initcon_files(dentry);
1980	if (ret)
1981		goto err;
1982
1983	fsi->class_dir = sel_make_dir(sb->s_root, "class", &fsi->last_ino);
1984	if (IS_ERR(fsi->class_dir)) {
1985		ret = PTR_ERR(fsi->class_dir);
1986		fsi->class_dir = NULL;
1987		goto err;
1988	}
1989
1990	fsi->policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities",
1991					  &fsi->last_ino);
1992	if (IS_ERR(fsi->policycap_dir)) {
1993		ret = PTR_ERR(fsi->policycap_dir);
1994		fsi->policycap_dir = NULL;
1995		goto err;
1996	}
1997
1998	ret = sel_make_policy_nodes(fsi);
1999	if (ret)
 
2000		goto err;
 
 
2001	return 0;
2002err:
2003	pr_err("SELinux: %s:  failed while creating inodes\n",
2004		__func__);
2005
2006	selinux_fs_info_free(sb);
2007
2008	return ret;
2009}
2010
2011static int sel_get_tree(struct fs_context *fc)
2012{
2013	return get_tree_single(fc, sel_fill_super);
2014}
2015
2016static const struct fs_context_operations sel_context_ops = {
2017	.get_tree	= sel_get_tree,
2018};
2019
2020static int sel_init_fs_context(struct fs_context *fc)
2021{
2022	fc->ops = &sel_context_ops;
2023	return 0;
2024}
2025
2026static void sel_kill_sb(struct super_block *sb)
2027{
2028	selinux_fs_info_free(sb);
2029	kill_litter_super(sb);
2030}
2031
2032static struct file_system_type sel_fs_type = {
2033	.name		= "selinuxfs",
2034	.init_fs_context = sel_init_fs_context,
2035	.kill_sb	= sel_kill_sb,
2036};
2037
2038struct vfsmount *selinuxfs_mount;
2039struct path selinux_null;
2040
2041static int __init init_sel_fs(void)
2042{
2043	struct qstr null_name = QSTR_INIT(NULL_FILE_NAME,
2044					  sizeof(NULL_FILE_NAME)-1);
2045	int err;
2046
2047	if (!selinux_enabled)
2048		return 0;
2049
2050	err = sysfs_create_mount_point(fs_kobj, "selinux");
2051	if (err)
2052		return err;
2053
2054	err = register_filesystem(&sel_fs_type);
2055	if (err) {
2056		sysfs_remove_mount_point(fs_kobj, "selinux");
2057		return err;
2058	}
2059
2060	selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
2061	if (IS_ERR(selinuxfs_mount)) {
2062		pr_err("selinuxfs:  could not mount!\n");
2063		err = PTR_ERR(selinuxfs_mount);
2064		selinuxfs_mount = NULL;
 
2065	}
 
2066	selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root,
2067						&null_name);
2068	if (IS_ERR(selinux_null.dentry)) {
2069		pr_err("selinuxfs:  could not lookup null!\n");
2070		err = PTR_ERR(selinux_null.dentry);
2071		selinux_null.dentry = NULL;
 
2072	}
2073
2074	return err;
2075}
2076
2077__initcall(init_sel_fs);
2078
2079#ifdef CONFIG_SECURITY_SELINUX_DISABLE
2080void exit_sel_fs(void)
2081{
2082	sysfs_remove_mount_point(fs_kobj, "selinux");
2083	dput(selinux_null.dentry);
2084	kern_unmount(selinuxfs_mount);
2085	unregister_filesystem(&sel_fs_type);
2086}
2087#endif