hooks.c 145.9 KB
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/*
 *  NSA Security-Enhanced Linux (SELinux) security module
 *
 *  This file contains the SELinux hook function implementations.
 *
 *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
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 *	      Chris Vance, <cvance@nai.com>
 *	      Wayne Salamon, <wsalamon@nai.com>
 *	      James Morris <jmorris@redhat.com>
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 *
 *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
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 *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
 *					   Eric Paris <eparis@redhat.com>
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 *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
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 *			    <dgoeddel@trustedcs.com>
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 *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
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 *	Paul Moore <paul@paul-moore.com>
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 *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
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 *		       Yuichi Nakamura <ynakam@hitachisoft.jp>
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 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License version 2,
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 *	as published by the Free Software Foundation.
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 */

#include <linux/init.h>
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#include <linux/kd.h>
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#include <linux/kernel.h>
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#include <linux/tracehook.h>
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#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/xattr.h>
#include <linux/capability.h>
#include <linux/unistd.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
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#include <linux/proc_fs.h>
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#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
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#include <linux/dcache.h>
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#include <linux/file.h>
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#include <linux/fdtable.h>
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#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/tty.h>
#include <net/icmp.h>
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#include <net/ip.h>		/* for local_port_range[] */
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#include <net/sock.h>
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#include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
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#include <net/net_namespace.h>
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#include <net/netlabel.h>
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#include <linux/uaccess.h>
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#include <asm/ioctls.h>
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#include <linux/atomic.h>
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#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>	/* for network interface checks */
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#include <net/netlink.h>
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#include <linux/tcp.h>
#include <linux/udp.h>
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#include <linux/dccp.h>
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#include <linux/quota.h>
#include <linux/un.h>		/* for Unix socket types */
#include <net/af_unix.h>	/* for Unix socket types */
#include <linux/parser.h>
#include <linux/nfs_mount.h>
#include <net/ipv6.h>
#include <linux/hugetlb.h>
#include <linux/personality.h>
#include <linux/audit.h>
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#include <linux/string.h>
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#include <linux/selinux.h>
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#include <linux/mutex.h>
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#include <linux/posix-timers.h>
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#include <linux/syslog.h>
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#include <linux/user_namespace.h>
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#include <linux/export.h>
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#include <linux/security.h>
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#include <linux/msg.h>
#include <linux/shm.h>
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#include "avc.h"
#include "objsec.h"
#include "netif.h"
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#include "netnode.h"
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#include "netport.h"
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#include "xfrm.h"
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#include "netlabel.h"
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#include "audit.h"
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#include "avc_ss.h"
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#define NUM_SEL_MNT_OPTS 5
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extern struct security_operations *security_ops;
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/* SECMARK reference count */
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static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
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#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
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int selinux_enforcing;
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static int __init enforcing_setup(char *str)
{
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	unsigned long enforcing;
	if (!strict_strtoul(str, 0, &enforcing))
		selinux_enforcing = enforcing ? 1 : 0;
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	return 1;
}
__setup("enforcing=", enforcing_setup);
#endif

#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;

static int __init selinux_enabled_setup(char *str)
{
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	unsigned long enabled;
	if (!strict_strtoul(str, 0, &enabled))
		selinux_enabled = enabled ? 1 : 0;
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	return 1;
}
__setup("selinux=", selinux_enabled_setup);
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#else
int selinux_enabled = 1;
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#endif

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static struct kmem_cache *sel_inode_cache;
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/**
 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
 *
 * Description:
 * This function checks the SECMARK reference counter to see if any SECMARK
 * targets are currently configured, if the reference counter is greater than
 * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
 * enabled, false (0) if SECMARK is disabled.
 *
 */
static int selinux_secmark_enabled(void)
{
	return (atomic_read(&selinux_secmark_refcount) > 0);
}

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/*
 * initialise the security for the init task
 */
static void cred_init_security(void)
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{
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	struct cred *cred = (struct cred *) current->real_cred;
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	struct task_security_struct *tsec;

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	tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
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	if (!tsec)
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		panic("SELinux:  Failed to initialize initial task.\n");
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	tsec->osid = tsec->sid = SECINITSID_KERNEL;
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	cred->security = tsec;
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}

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/*
 * get the security ID of a set of credentials
 */
static inline u32 cred_sid(const struct cred *cred)
{
	const struct task_security_struct *tsec;

	tsec = cred->security;
	return tsec->sid;
}

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/*
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 * get the objective security ID of a task
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 */
static inline u32 task_sid(const struct task_struct *task)
{
	u32 sid;

	rcu_read_lock();
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	sid = cred_sid(__task_cred(task));
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	rcu_read_unlock();
	return sid;
}

/*
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 * get the subjective security ID of the current task
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 */
static inline u32 current_sid(void)
{
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	const struct task_security_struct *tsec = current_security();
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	return tsec->sid;
}

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/* Allocate and free functions for each kind of security blob. */

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static int inode_alloc_security(struct inode *inode)
{
	struct inode_security_struct *isec;
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	u32 sid = current_sid();
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	isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
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	if (!isec)
		return -ENOMEM;

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	mutex_init(&isec->lock);
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	INIT_LIST_HEAD(&isec->list);
	isec->inode = inode;
	isec->sid = SECINITSID_UNLABELED;
	isec->sclass = SECCLASS_FILE;
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	isec->task_sid = sid;
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	inode->i_security = isec;

	return 0;
}

static void inode_free_security(struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec = inode->i_sb->s_security;

	spin_lock(&sbsec->isec_lock);
	if (!list_empty(&isec->list))
		list_del_init(&isec->list);
	spin_unlock(&sbsec->isec_lock);

	inode->i_security = NULL;
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	kmem_cache_free(sel_inode_cache, isec);
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}

static int file_alloc_security(struct file *file)
{
	struct file_security_struct *fsec;
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	u32 sid = current_sid();
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	fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
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	if (!fsec)
		return -ENOMEM;

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	fsec->sid = sid;
	fsec->fown_sid = sid;
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	file->f_security = fsec;

	return 0;
}

static void file_free_security(struct file *file)
{
	struct file_security_struct *fsec = file->f_security;
	file->f_security = NULL;
	kfree(fsec);
}

static int superblock_alloc_security(struct super_block *sb)
{
	struct superblock_security_struct *sbsec;

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	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
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	if (!sbsec)
		return -ENOMEM;

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	mutex_init(&sbsec->lock);
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	INIT_LIST_HEAD(&sbsec->isec_head);
	spin_lock_init(&sbsec->isec_lock);
	sbsec->sb = sb;
	sbsec->sid = SECINITSID_UNLABELED;
	sbsec->def_sid = SECINITSID_FILE;
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	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
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	sb->s_security = sbsec;

	return 0;
}

static void superblock_free_security(struct super_block *sb)
{
	struct superblock_security_struct *sbsec = sb->s_security;
	sb->s_security = NULL;
	kfree(sbsec);
}

/* The file system's label must be initialized prior to use. */

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static const char *labeling_behaviors[7] = {
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	"uses xattr",
	"uses transition SIDs",
	"uses task SIDs",
	"uses genfs_contexts",
	"not configured for labeling",
	"uses mountpoint labeling",
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	"uses native labeling",
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};

static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);

static inline int inode_doinit(struct inode *inode)
{
	return inode_doinit_with_dentry(inode, NULL);
}

enum {
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	Opt_error = -1,
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	Opt_context = 1,
	Opt_fscontext = 2,
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	Opt_defcontext = 3,
	Opt_rootcontext = 4,
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	Opt_labelsupport = 5,
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};

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static const match_table_t tokens = {
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	{Opt_context, CONTEXT_STR "%s"},
	{Opt_fscontext, FSCONTEXT_STR "%s"},
	{Opt_defcontext, DEFCONTEXT_STR "%s"},
	{Opt_rootcontext, ROOTCONTEXT_STR "%s"},
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	{Opt_labelsupport, LABELSUPP_STR},
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	{Opt_error, NULL},
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};

#define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"

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static int may_context_mount_sb_relabel(u32 sid,
			struct superblock_security_struct *sbsec,
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			const struct cred *cred)
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{
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	const struct task_security_struct *tsec = cred->security;
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	int rc;

	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
			  FILESYSTEM__RELABELFROM, NULL);
	if (rc)
		return rc;

	rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
			  FILESYSTEM__RELABELTO, NULL);
	return rc;
}

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static int may_context_mount_inode_relabel(u32 sid,
			struct superblock_security_struct *sbsec,
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			const struct cred *cred)
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{
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	const struct task_security_struct *tsec = cred->security;
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	int rc;
	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
			  FILESYSTEM__RELABELFROM, NULL);
	if (rc)
		return rc;

	rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
			  FILESYSTEM__ASSOCIATE, NULL);
	return rc;
}

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static int sb_finish_set_opts(struct super_block *sb)
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{
	struct superblock_security_struct *sbsec = sb->s_security;
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	struct dentry *root = sb->s_root;
	struct inode *root_inode = root->d_inode;
	int rc = 0;
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	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
		/* Make sure that the xattr handler exists and that no
		   error other than -ENODATA is returned by getxattr on
		   the root directory.  -ENODATA is ok, as this may be
		   the first boot of the SELinux kernel before we have
		   assigned xattr values to the filesystem. */
		if (!root_inode->i_op->getxattr) {
			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
			       "xattr support\n", sb->s_id, sb->s_type->name);
			rc = -EOPNOTSUPP;
			goto out;
		}
		rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
		if (rc < 0 && rc != -ENODATA) {
			if (rc == -EOPNOTSUPP)
				printk(KERN_WARNING "SELinux: (dev %s, type "
				       "%s) has no security xattr handler\n",
				       sb->s_id, sb->s_type->name);
			else
				printk(KERN_WARNING "SELinux: (dev %s, type "
				       "%s) getxattr errno %d\n", sb->s_id,
				       sb->s_type->name, -rc);
			goto out;
		}
	}
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	sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
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	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
		       sb->s_id, sb->s_type->name);
	else
		printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
		       sb->s_id, sb->s_type->name,
		       labeling_behaviors[sbsec->behavior-1]);
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	if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
	    sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
	    sbsec->behavior == SECURITY_FS_USE_NONE ||
	    sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
		sbsec->flags &= ~SE_SBLABELSUPP;

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	/* Special handling for sysfs. Is genfs but also has setxattr handler*/
	if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
		sbsec->flags |= SE_SBLABELSUPP;

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	/* Initialize the root inode. */
	rc = inode_doinit_with_dentry(root_inode, root);
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	/* Initialize any other inodes associated with the superblock, e.g.
	   inodes created prior to initial policy load or inodes created
	   during get_sb by a pseudo filesystem that directly
	   populates itself. */
	spin_lock(&sbsec->isec_lock);
next_inode:
	if (!list_empty(&sbsec->isec_head)) {
		struct inode_security_struct *isec =
				list_entry(sbsec->isec_head.next,
					   struct inode_security_struct, list);
		struct inode *inode = isec->inode;
		spin_unlock(&sbsec->isec_lock);
		inode = igrab(inode);
		if (inode) {
			if (!IS_PRIVATE(inode))
				inode_doinit(inode);
			iput(inode);
		}
		spin_lock(&sbsec->isec_lock);
		list_del_init(&isec->list);
		goto next_inode;
	}
	spin_unlock(&sbsec->isec_lock);
out:
	return rc;
}
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/*
 * This function should allow an FS to ask what it's mount security
 * options were so it can use those later for submounts, displaying
 * mount options, or whatever.
 */
static int selinux_get_mnt_opts(const struct super_block *sb,
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				struct security_mnt_opts *opts)
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{
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	char *context = NULL;
	u32 len;
	char tmp;
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	security_init_mnt_opts(opts);
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	if (!(sbsec->flags & SE_SBINITIALIZED))
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		return -EINVAL;
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	if (!ss_initialized)
		return -EINVAL;
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	tmp = sbsec->flags & SE_MNTMASK;
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	/* count the number of mount options for this sb */
	for (i = 0; i < 8; i++) {
		if (tmp & 0x01)
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			opts->num_mnt_opts++;
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		tmp >>= 1;
	}
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	/* Check if the Label support flag is set */
	if (sbsec->flags & SE_SBLABELSUPP)
		opts->num_mnt_opts++;
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	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts) {
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		rc = -ENOMEM;
		goto out_free;
	}
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	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
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		rc = -ENOMEM;
		goto out_free;
	}
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	i = 0;
	if (sbsec->flags & FSCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->sid, &context, &len);
		if (rc)
			goto out_free;
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		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
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	}
	if (sbsec->flags & CONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
		if (rc)
			goto out_free;
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		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
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	}
	if (sbsec->flags & DEFCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
		if (rc)
			goto out_free;
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		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
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	}
	if (sbsec->flags & ROOTCONTEXT_MNT) {
		struct inode *root = sbsec->sb->s_root->d_inode;
		struct inode_security_struct *isec = root->i_security;
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		rc = security_sid_to_context(isec->sid, &context, &len);
		if (rc)
			goto out_free;
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		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
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	}
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	if (sbsec->flags & SE_SBLABELSUPP) {
		opts->mnt_opts[i] = NULL;
		opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
	}
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	BUG_ON(i != opts->num_mnt_opts);
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	return 0;

out_free:
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	security_free_mnt_opts(opts);
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	return rc;
}
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static int bad_option(struct superblock_security_struct *sbsec, char flag,
		      u32 old_sid, u32 new_sid)
{
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	char mnt_flags = sbsec->flags & SE_MNTMASK;

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	/* check if the old mount command had the same options */
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	if (sbsec->flags & SE_SBINITIALIZED)
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		if (!(sbsec->flags & flag) ||
		    (old_sid != new_sid))
			return 1;

	/* check if we were passed the same options twice,
	 * aka someone passed context=a,context=b
	 */
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	if (!(sbsec->flags & SE_SBINITIALIZED))
		if (mnt_flags & flag)
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			return 1;
	return 0;
}
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/*
 * Allow filesystems with binary mount data to explicitly set mount point
 * labeling information.
 */
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static int selinux_set_mnt_opts(struct super_block *sb,
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				struct security_mnt_opts *opts,
				unsigned long kern_flags,
				unsigned long *set_kern_flags)
560
{
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	const struct cred *cred = current_cred();
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	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	const char *name = sb->s_type->name;
565 566
	struct inode *inode = sbsec->sb->s_root->d_inode;
	struct inode_security_struct *root_isec = inode->i_security;
567 568
	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
	u32 defcontext_sid = 0;
569 570 571
	char **mount_options = opts->mnt_opts;
	int *flags = opts->mnt_opts_flags;
	int num_opts = opts->num_mnt_opts;
572 573 574 575 576 577 578 579 580 581 582

	mutex_lock(&sbsec->lock);

	if (!ss_initialized) {
		if (!num_opts) {
			/* Defer initialization until selinux_complete_init,
			   after the initial policy is loaded and the security
			   server is ready to handle calls. */
			goto out;
		}
		rc = -EINVAL;
E
Eric Paris 已提交
583 584
		printk(KERN_WARNING "SELinux: Unable to set superblock options "
			"before the security server is initialized\n");
L
Linus Torvalds 已提交
585
		goto out;
586
	}
587 588 589 590 591 592
	if (kern_flags && !set_kern_flags) {
		/* Specifying internal flags without providing a place to
		 * place the results is not allowed */
		rc = -EINVAL;
		goto out;
	}
L
Linus Torvalds 已提交
593

594 595 596 597 598 599 600 601 602 603 604
	/*
	 * Binary mount data FS will come through this function twice.  Once
	 * from an explicit call and once from the generic calls from the vfs.
	 * Since the generic VFS calls will not contain any security mount data
	 * we need to skip the double mount verification.
	 *
	 * This does open a hole in which we will not notice if the first
	 * mount using this sb set explict options and a second mount using
	 * this sb does not set any security options.  (The first options
	 * will be used for both mounts)
	 */
605
	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
606
	    && (num_opts == 0))
607
		goto out;
608

609 610 611 612 613 614 615
	/*
	 * parse the mount options, check if they are valid sids.
	 * also check if someone is trying to mount the same sb more
	 * than once with different security options.
	 */
	for (i = 0; i < num_opts; i++) {
		u32 sid;
616 617 618

		if (flags[i] == SE_SBLABELSUPP)
			continue;
619 620
		rc = security_context_to_sid(mount_options[i],
					     strlen(mount_options[i]), &sid);
L
Linus Torvalds 已提交
621 622 623
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668
			       mount_options[i], sb->s_id, name, rc);
			goto out;
		}
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			fscontext_sid = sid;

			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
					fscontext_sid))
				goto out_double_mount;

			sbsec->flags |= FSCONTEXT_MNT;
			break;
		case CONTEXT_MNT:
			context_sid = sid;

			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
					context_sid))
				goto out_double_mount;

			sbsec->flags |= CONTEXT_MNT;
			break;
		case ROOTCONTEXT_MNT:
			rootcontext_sid = sid;

			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
					rootcontext_sid))
				goto out_double_mount;

			sbsec->flags |= ROOTCONTEXT_MNT;

			break;
		case DEFCONTEXT_MNT:
			defcontext_sid = sid;

			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
					defcontext_sid))
				goto out_double_mount;

			sbsec->flags |= DEFCONTEXT_MNT;

			break;
		default:
			rc = -EINVAL;
			goto out;
L
Linus Torvalds 已提交
669
		}
670 671
	}

672
	if (sbsec->flags & SE_SBINITIALIZED) {
673
		/* previously mounted with options, but not on this attempt? */
674
		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
675 676 677 678 679
			goto out_double_mount;
		rc = 0;
		goto out;
	}

680
	if (strcmp(sb->s_type->name, "proc") == 0)
681
		sbsec->flags |= SE_SBPROC;
682

683 684 685 686 687 688 689 690 691 692 693 694 695 696
	if (!sbsec->behavior) {
		/*
		 * Determine the labeling behavior to use for this
		 * filesystem type.
		 */
		rc = security_fs_use((sbsec->flags & SE_SBPROC) ?
					"proc" : sb->s_type->name,
					&sbsec->behavior, &sbsec->sid);
		if (rc) {
			printk(KERN_WARNING
				"%s: security_fs_use(%s) returned %d\n",
					__func__, sb->s_type->name, rc);
			goto out;
		}
697 698 699
	}
	/* sets the context of the superblock for the fs being mounted. */
	if (fscontext_sid) {
700
		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
L
Linus Torvalds 已提交
701
		if (rc)
702
			goto out;
L
Linus Torvalds 已提交
703

704
		sbsec->sid = fscontext_sid;
705 706 707 708 709 710 711
	}

	/*
	 * Switch to using mount point labeling behavior.
	 * sets the label used on all file below the mountpoint, and will set
	 * the superblock context if not already set.
	 */
712 713 714 715 716
	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
		sbsec->behavior = SECURITY_FS_USE_NATIVE;
		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
	}

717 718
	if (context_sid) {
		if (!fscontext_sid) {
719 720
			rc = may_context_mount_sb_relabel(context_sid, sbsec,
							  cred);
721
			if (rc)
722 723
				goto out;
			sbsec->sid = context_sid;
724
		} else {
725 726
			rc = may_context_mount_inode_relabel(context_sid, sbsec,
							     cred);
727
			if (rc)
728
				goto out;
729
		}
730 731
		if (!rootcontext_sid)
			rootcontext_sid = context_sid;
L
Linus Torvalds 已提交
732

733
		sbsec->mntpoint_sid = context_sid;
734
		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
L
Linus Torvalds 已提交
735 736
	}

737
	if (rootcontext_sid) {
738 739
		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
						     cred);
740
		if (rc)
741
			goto out;
742

743 744
		root_isec->sid = rootcontext_sid;
		root_isec->initialized = 1;
745 746
	}

747
	if (defcontext_sid) {
748 749
		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
750 751 752 753
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux: defcontext option is "
			       "invalid for this filesystem type\n");
			goto out;
L
Linus Torvalds 已提交
754 755
		}

756 757
		if (defcontext_sid != sbsec->def_sid) {
			rc = may_context_mount_inode_relabel(defcontext_sid,
758
							     sbsec, cred);
759 760 761
			if (rc)
				goto out;
		}
L
Linus Torvalds 已提交
762

763
		sbsec->def_sid = defcontext_sid;
L
Linus Torvalds 已提交
764 765
	}

766
	rc = sb_finish_set_opts(sb);
L
Linus Torvalds 已提交
767
out:
768
	mutex_unlock(&sbsec->lock);
L
Linus Torvalds 已提交
769
	return rc;
770 771 772 773 774
out_double_mount:
	rc = -EINVAL;
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
	goto out;
L
Linus Torvalds 已提交
775 776
}

777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807
static int selinux_cmp_sb_context(const struct super_block *oldsb,
				    const struct super_block *newsb)
{
	struct superblock_security_struct *old = oldsb->s_security;
	struct superblock_security_struct *new = newsb->s_security;
	char oldflags = old->flags & SE_MNTMASK;
	char newflags = new->flags & SE_MNTMASK;

	if (oldflags != newflags)
		goto mismatch;
	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
		goto mismatch;
	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
		goto mismatch;
	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
		goto mismatch;
	if (oldflags & ROOTCONTEXT_MNT) {
		struct inode_security_struct *oldroot = oldsb->s_root->d_inode->i_security;
		struct inode_security_struct *newroot = newsb->s_root->d_inode->i_security;
		if (oldroot->sid != newroot->sid)
			goto mismatch;
	}
	return 0;
mismatch:
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, "
			    "different security settings for (dev %s, "
			    "type %s)\n", newsb->s_id, newsb->s_type->name);
	return -EBUSY;
}

static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
808
					struct super_block *newsb)
L
Linus Torvalds 已提交
809
{
810 811
	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
	struct superblock_security_struct *newsbsec = newsb->s_security;
L
Linus Torvalds 已提交
812

813 814 815
	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);
L
Linus Torvalds 已提交
816

817 818
	/*
	 * if the parent was able to be mounted it clearly had no special lsm
819
	 * mount options.  thus we can safely deal with this superblock later
820
	 */
821
	if (!ss_initialized)
822
		return 0;
823 824

	/* how can we clone if the old one wasn't set up?? */
825
	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
826

827
	/* if fs is reusing a sb, make sure that the contexts match */
828
	if (newsbsec->flags & SE_SBINITIALIZED)
829
		return selinux_cmp_sb_context(oldsb, newsb);
830

831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849
	mutex_lock(&newsbsec->lock);

	newsbsec->flags = oldsbsec->flags;

	newsbsec->sid = oldsbsec->sid;
	newsbsec->def_sid = oldsbsec->def_sid;
	newsbsec->behavior = oldsbsec->behavior;

	if (set_context) {
		u32 sid = oldsbsec->mntpoint_sid;

		if (!set_fscontext)
			newsbsec->sid = sid;
		if (!set_rootcontext) {
			struct inode *newinode = newsb->s_root->d_inode;
			struct inode_security_struct *newisec = newinode->i_security;
			newisec->sid = sid;
		}
		newsbsec->mntpoint_sid = sid;
L
Linus Torvalds 已提交
850
	}
851 852 853 854 855
	if (set_rootcontext) {
		const struct inode *oldinode = oldsb->s_root->d_inode;
		const struct inode_security_struct *oldisec = oldinode->i_security;
		struct inode *newinode = newsb->s_root->d_inode;
		struct inode_security_struct *newisec = newinode->i_security;
L
Linus Torvalds 已提交
856

857
		newisec->sid = oldisec->sid;
L
Linus Torvalds 已提交
858 859
	}

860 861
	sb_finish_set_opts(newsb);
	mutex_unlock(&newsbsec->lock);
862
	return 0;
863 864
}

865 866
static int selinux_parse_opts_str(char *options,
				  struct security_mnt_opts *opts)
867
{
868
	char *p;
869 870
	char *context = NULL, *defcontext = NULL;
	char *fscontext = NULL, *rootcontext = NULL;
871
	int rc, num_mnt_opts = 0;
L
Linus Torvalds 已提交
872

873
	opts->num_mnt_opts = 0;
L
Linus Torvalds 已提交
874

875 876 877 878
	/* Standard string-based options. */
	while ((p = strsep(&options, "|")) != NULL) {
		int token;
		substring_t args[MAX_OPT_ARGS];
L
Linus Torvalds 已提交
879

880 881
		if (!*p)
			continue;
L
Linus Torvalds 已提交
882

883
		token = match_token(p, tokens, args);
L
Linus Torvalds 已提交
884

885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936
		switch (token) {
		case Opt_context:
			if (context || defcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			context = match_strdup(&args[0]);
			if (!context) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_fscontext:
			if (fscontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			fscontext = match_strdup(&args[0]);
			if (!fscontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_rootcontext:
			if (rootcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			rootcontext = match_strdup(&args[0]);
			if (!rootcontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_defcontext:
			if (context || defcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			defcontext = match_strdup(&args[0]);
			if (!defcontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;
937 938
		case Opt_labelsupport:
			break;
939 940 941 942
		default:
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux:  unknown mount option\n");
			goto out_err;
L
Linus Torvalds 已提交
943 944 945

		}
	}
946

947 948 949 950 951 952 953 954 955 956 957
	rc = -ENOMEM;
	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts)
		goto out_err;

	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
		kfree(opts->mnt_opts);
		goto out_err;
	}

958
	if (fscontext) {
959 960
		opts->mnt_opts[num_mnt_opts] = fscontext;
		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
961 962
	}
	if (context) {
963 964
		opts->mnt_opts[num_mnt_opts] = context;
		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
965 966
	}
	if (rootcontext) {
967 968
		opts->mnt_opts[num_mnt_opts] = rootcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
969 970
	}
	if (defcontext) {
971 972
		opts->mnt_opts[num_mnt_opts] = defcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
973 974
	}

975 976 977
	opts->num_mnt_opts = num_mnt_opts;
	return 0;

978 979 980 981 982
out_err:
	kfree(context);
	kfree(defcontext);
	kfree(fscontext);
	kfree(rootcontext);
L
Linus Torvalds 已提交
983 984
	return rc;
}
985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005
/*
 * string mount options parsing and call set the sbsec
 */
static int superblock_doinit(struct super_block *sb, void *data)
{
	int rc = 0;
	char *options = data;
	struct security_mnt_opts opts;

	security_init_mnt_opts(&opts);

	if (!data)
		goto out;

	BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);

	rc = selinux_parse_opts_str(options, &opts);
	if (rc)
		goto out_err;

out:
1006
	rc = selinux_set_mnt_opts(sb, &opts, 0, NULL);
1007 1008 1009 1010 1011

out_err:
	security_free_mnt_opts(&opts);
	return rc;
}
L
Linus Torvalds 已提交
1012

A
Adrian Bunk 已提交
1013 1014
static void selinux_write_opts(struct seq_file *m,
			       struct security_mnt_opts *opts)
1015 1016 1017 1018 1019
{
	int i;
	char *prefix;

	for (i = 0; i < opts->num_mnt_opts; i++) {
1020 1021 1022 1023 1024 1025
		char *has_comma;

		if (opts->mnt_opts[i])
			has_comma = strchr(opts->mnt_opts[i], ',');
		else
			has_comma = NULL;
1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039

		switch (opts->mnt_opts_flags[i]) {
		case CONTEXT_MNT:
			prefix = CONTEXT_STR;
			break;
		case FSCONTEXT_MNT:
			prefix = FSCONTEXT_STR;
			break;
		case ROOTCONTEXT_MNT:
			prefix = ROOTCONTEXT_STR;
			break;
		case DEFCONTEXT_MNT:
			prefix = DEFCONTEXT_STR;
			break;
1040 1041 1042 1043
		case SE_SBLABELSUPP:
			seq_putc(m, ',');
			seq_puts(m, LABELSUPP_STR);
			continue;
1044 1045
		default:
			BUG();
1046
			return;
1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064
		};
		/* we need a comma before each option */
		seq_putc(m, ',');
		seq_puts(m, prefix);
		if (has_comma)
			seq_putc(m, '\"');
		seq_puts(m, opts->mnt_opts[i]);
		if (has_comma)
			seq_putc(m, '\"');
	}
}

static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
{
	struct security_mnt_opts opts;
	int rc;

	rc = selinux_get_mnt_opts(sb, &opts);
1065 1066 1067 1068
	if (rc) {
		/* before policy load we may get EINVAL, don't show anything */
		if (rc == -EINVAL)
			rc = 0;
1069
		return rc;
1070
	}
1071 1072 1073 1074 1075 1076 1077 1078

	selinux_write_opts(m, &opts);

	security_free_mnt_opts(&opts);

	return rc;
}

L
Linus Torvalds 已提交
1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101
static inline u16 inode_mode_to_security_class(umode_t mode)
{
	switch (mode & S_IFMT) {
	case S_IFSOCK:
		return SECCLASS_SOCK_FILE;
	case S_IFLNK:
		return SECCLASS_LNK_FILE;
	case S_IFREG:
		return SECCLASS_FILE;
	case S_IFBLK:
		return SECCLASS_BLK_FILE;
	case S_IFDIR:
		return SECCLASS_DIR;
	case S_IFCHR:
		return SECCLASS_CHR_FILE;
	case S_IFIFO:
		return SECCLASS_FIFO_FILE;

	}

	return SECCLASS_FILE;
}

1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
static inline int default_protocol_stream(int protocol)
{
	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
}

static inline int default_protocol_dgram(int protocol)
{
	return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
}

L
Linus Torvalds 已提交
1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127
static inline u16 socket_type_to_security_class(int family, int type, int protocol)
{
	switch (family) {
	case PF_UNIX:
		switch (type) {
		case SOCK_STREAM:
		case SOCK_SEQPACKET:
			return SECCLASS_UNIX_STREAM_SOCKET;
		case SOCK_DGRAM:
			return SECCLASS_UNIX_DGRAM_SOCKET;
		}
		break;
	case PF_INET:
	case PF_INET6:
		switch (type) {
		case SOCK_STREAM:
1128 1129 1130 1131
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
L
Linus Torvalds 已提交
1132
		case SOCK_DGRAM:
1133 1134 1135 1136
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
J
James Morris 已提交
1137 1138
		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
1139
		default:
L
Linus Torvalds 已提交
1140 1141 1142 1143 1144 1145 1146 1147 1148
			return SECCLASS_RAWIP_SOCKET;
		}
		break;
	case PF_NETLINK:
		switch (protocol) {
		case NETLINK_ROUTE:
			return SECCLASS_NETLINK_ROUTE_SOCKET;
		case NETLINK_FIREWALL:
			return SECCLASS_NETLINK_FIREWALL_SOCKET;
1149
		case NETLINK_SOCK_DIAG:
L
Linus Torvalds 已提交
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162
			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
		case NETLINK_NFLOG:
			return SECCLASS_NETLINK_NFLOG_SOCKET;
		case NETLINK_XFRM:
			return SECCLASS_NETLINK_XFRM_SOCKET;
		case NETLINK_SELINUX:
			return SECCLASS_NETLINK_SELINUX_SOCKET;
		case NETLINK_AUDIT:
			return SECCLASS_NETLINK_AUDIT_SOCKET;
		case NETLINK_IP6_FW:
			return SECCLASS_NETLINK_IP6FW_SOCKET;
		case NETLINK_DNRTMSG:
			return SECCLASS_NETLINK_DNRT_SOCKET;
1163 1164
		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
L
Linus Torvalds 已提交
1165 1166 1167 1168 1169 1170 1171
		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
1172 1173
	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
L
Linus Torvalds 已提交
1174 1175 1176 1177 1178 1179
	}

	return SECCLASS_SOCKET;
}

#ifdef CONFIG_PROC_FS
1180
static int selinux_proc_get_sid(struct dentry *dentry,
L
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1181 1182 1183
				u16 tclass,
				u32 *sid)
{
1184 1185
	int rc;
	char *buffer, *path;
L
Linus Torvalds 已提交
1186

1187
	buffer = (char *)__get_free_page(GFP_KERNEL);
L
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1188 1189 1190
	if (!buffer)
		return -ENOMEM;

1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
	if (IS_ERR(path))
		rc = PTR_ERR(path);
	else {
		/* each process gets a /proc/PID/ entry. Strip off the
		 * PID part to get a valid selinux labeling.
		 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
		while (path[1] >= '0' && path[1] <= '9') {
			path[1] = '/';
			path++;
		}
		rc = security_genfs_sid("proc", path, tclass, sid);
L
Linus Torvalds 已提交
1203 1204 1205 1206 1207
	}
	free_page((unsigned long)buffer);
	return rc;
}
#else
1208
static int selinux_proc_get_sid(struct dentry *dentry,
L
Linus Torvalds 已提交
1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230
				u16 tclass,
				u32 *sid)
{
	return -EINVAL;
}
#endif

/* The inode's security attributes must be initialized before first use. */
static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
{
	struct superblock_security_struct *sbsec = NULL;
	struct inode_security_struct *isec = inode->i_security;
	u32 sid;
	struct dentry *dentry;
#define INITCONTEXTLEN 255
	char *context = NULL;
	unsigned len = 0;
	int rc = 0;

	if (isec->initialized)
		goto out;

1231
	mutex_lock(&isec->lock);
L
Linus Torvalds 已提交
1232
	if (isec->initialized)
1233
		goto out_unlock;
L
Linus Torvalds 已提交
1234 1235

	sbsec = inode->i_sb->s_security;
1236
	if (!(sbsec->flags & SE_SBINITIALIZED)) {
L
Linus Torvalds 已提交
1237 1238 1239 1240 1241 1242 1243
		/* Defer initialization until selinux_complete_init,
		   after the initial policy is loaded and the security
		   server is ready to handle calls. */
		spin_lock(&sbsec->isec_lock);
		if (list_empty(&isec->list))
			list_add(&isec->list, &sbsec->isec_head);
		spin_unlock(&sbsec->isec_lock);
1244
		goto out_unlock;
L
Linus Torvalds 已提交
1245 1246 1247
	}

	switch (sbsec->behavior) {
1248 1249
	case SECURITY_FS_USE_NATIVE:
		break;
L
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1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265
	case SECURITY_FS_USE_XATTR:
		if (!inode->i_op->getxattr) {
			isec->sid = sbsec->def_sid;
			break;
		}

		/* Need a dentry, since the xattr API requires one.
		   Life would be simpler if we could just pass the inode. */
		if (opt_dentry) {
			/* Called from d_instantiate or d_splice_alias. */
			dentry = dget(opt_dentry);
		} else {
			/* Called from selinux_complete_init, try to find a dentry. */
			dentry = d_find_alias(inode);
		}
		if (!dentry) {
1266 1267 1268 1269 1270 1271 1272 1273 1274
			/*
			 * this is can be hit on boot when a file is accessed
			 * before the policy is loaded.  When we load policy we
			 * may find inodes that have no dentry on the
			 * sbsec->isec_head list.  No reason to complain as these
			 * will get fixed up the next time we go through
			 * inode_doinit with a dentry, before these inodes could
			 * be used again by userspace.
			 */
1275
			goto out_unlock;
L
Linus Torvalds 已提交
1276 1277 1278
		}

		len = INITCONTEXTLEN;
1279
		context = kmalloc(len+1, GFP_NOFS);
L
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1280 1281 1282
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
1283
			goto out_unlock;
L
Linus Torvalds 已提交
1284
		}
1285
		context[len] = '\0';
L
Linus Torvalds 已提交
1286 1287 1288
		rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
					   context, len);
		if (rc == -ERANGE) {
1289 1290
			kfree(context);

L
Linus Torvalds 已提交
1291 1292 1293 1294 1295
			/* Need a larger buffer.  Query for the right size. */
			rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
						   NULL, 0);
			if (rc < 0) {
				dput(dentry);
1296
				goto out_unlock;
L
Linus Torvalds 已提交
1297 1298
			}
			len = rc;
1299
			context = kmalloc(len+1, GFP_NOFS);
L
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1300 1301 1302
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
1303
				goto out_unlock;
L
Linus Torvalds 已提交
1304
			}
1305
			context[len] = '\0';
L
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1306 1307 1308 1309 1310 1311 1312
			rc = inode->i_op->getxattr(dentry,
						   XATTR_NAME_SELINUX,
						   context, len);
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
E
Eric Paris 已提交
1313
				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1314
				       "%d for dev=%s ino=%ld\n", __func__,
L
Linus Torvalds 已提交
1315 1316
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
1317
				goto out_unlock;
L
Linus Torvalds 已提交
1318 1319 1320 1321 1322
			}
			/* Map ENODATA to the default file SID */
			sid = sbsec->def_sid;
			rc = 0;
		} else {
1323
			rc = security_context_to_sid_default(context, rc, &sid,
1324 1325
							     sbsec->def_sid,
							     GFP_NOFS);
L
Linus Torvalds 已提交
1326
			if (rc) {
1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339
				char *dev = inode->i_sb->s_id;
				unsigned long ino = inode->i_ino;

				if (rc == -EINVAL) {
					if (printk_ratelimit())
						printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
							"context=%s.  This indicates you may need to relabel the inode or the "
							"filesystem in question.\n", ino, dev, context);
				} else {
					printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
					       "returned %d for dev=%s ino=%ld\n",
					       __func__, context, -rc, dev, ino);
				}
L
Linus Torvalds 已提交
1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
				kfree(context);
				/* Leave with the unlabeled SID */
				rc = 0;
				break;
			}
		}
		kfree(context);
		isec->sid = sid;
		break;
	case SECURITY_FS_USE_TASK:
		isec->sid = isec->task_sid;
		break;
	case SECURITY_FS_USE_TRANS:
		/* Default to the fs SID. */
		isec->sid = sbsec->sid;

		/* Try to obtain a transition SID. */
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1358 1359
		rc = security_transition_sid(isec->task_sid, sbsec->sid,
					     isec->sclass, NULL, &sid);
L
Linus Torvalds 已提交
1360
		if (rc)
1361
			goto out_unlock;
L
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1362 1363
		isec->sid = sid;
		break;
1364 1365 1366
	case SECURITY_FS_USE_MNTPOINT:
		isec->sid = sbsec->mntpoint_sid;
		break;
L
Linus Torvalds 已提交
1367
	default:
1368
		/* Default to the fs superblock SID. */
L
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1369 1370
		isec->sid = sbsec->sid;

1371
		if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1372
			if (opt_dentry) {
L
Linus Torvalds 已提交
1373
				isec->sclass = inode_mode_to_security_class(inode->i_mode);
1374
				rc = selinux_proc_get_sid(opt_dentry,
L
Linus Torvalds 已提交
1375 1376 1377
							  isec->sclass,
							  &sid);
				if (rc)
1378
					goto out_unlock;
L
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1379 1380 1381 1382 1383 1384 1385 1386
				isec->sid = sid;
			}
		}
		break;
	}

	isec->initialized = 1;

1387 1388
out_unlock:
	mutex_unlock(&isec->lock);
L
Linus Torvalds 已提交
1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
out:
	if (isec->sclass == SECCLASS_FILE)
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
	return rc;
}

/* Convert a Linux signal to an access vector. */
static inline u32 signal_to_av(int sig)
{
	u32 perm = 0;

	switch (sig) {
	case SIGCHLD:
		/* Commonly granted from child to parent. */
		perm = PROCESS__SIGCHLD;
		break;
	case SIGKILL:
		/* Cannot be caught or ignored */
		perm = PROCESS__SIGKILL;
		break;
	case SIGSTOP:
		/* Cannot be caught or ignored */
		perm = PROCESS__SIGSTOP;
		break;
	default:
		/* All other signals. */
		perm = PROCESS__SIGNAL;
		break;
	}

	return perm;
}

D
David Howells 已提交
1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434
/*
 * Check permission between a pair of credentials
 * fork check, ptrace check, etc.
 */
static int cred_has_perm(const struct cred *actor,
			 const struct cred *target,
			 u32 perms)
{
	u32 asid = cred_sid(actor), tsid = cred_sid(target);

	return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
}

1435
/*
1436
 * Check permission between a pair of tasks, e.g. signal checks,
1437 1438
 * fork check, ptrace check, etc.
 * tsk1 is the actor and tsk2 is the target
1439
 * - this uses the default subjective creds of tsk1
1440 1441 1442
 */
static int task_has_perm(const struct task_struct *tsk1,
			 const struct task_struct *tsk2,
L
Linus Torvalds 已提交
1443 1444
			 u32 perms)
{
1445 1446
	const struct task_security_struct *__tsec1, *__tsec2;
	u32 sid1, sid2;
L
Linus Torvalds 已提交
1447

1448 1449 1450 1451 1452
	rcu_read_lock();
	__tsec1 = __task_cred(tsk1)->security;	sid1 = __tsec1->sid;
	__tsec2 = __task_cred(tsk2)->security;	sid2 = __tsec2->sid;
	rcu_read_unlock();
	return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
L
Linus Torvalds 已提交
1453 1454
}

1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470
/*
 * Check permission between current and another task, e.g. signal checks,
 * fork check, ptrace check, etc.
 * current is the actor and tsk2 is the target
 * - this uses current's subjective creds
 */
static int current_has_perm(const struct task_struct *tsk,
			    u32 perms)
{
	u32 sid, tsid;

	sid = current_sid();
	tsid = task_sid(tsk);
	return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
}

1471 1472 1473 1474
#if CAP_LAST_CAP > 63
#error Fix SELinux to handle capabilities > 63.
#endif

L
Linus Torvalds 已提交
1475
/* Check whether a task is allowed to use a capability. */
1476
static int cred_has_capability(const struct cred *cred,
1477
			       int cap, int audit)
L
Linus Torvalds 已提交
1478
{
1479
	struct common_audit_data ad;
1480
	struct av_decision avd;
1481
	u16 sclass;
1482
	u32 sid = cred_sid(cred);
1483
	u32 av = CAP_TO_MASK(cap);
1484
	int rc;
L
Linus Torvalds 已提交
1485

1486
	ad.type = LSM_AUDIT_DATA_CAP;
L
Linus Torvalds 已提交
1487 1488
	ad.u.cap = cap;

1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499
	switch (CAP_TO_INDEX(cap)) {
	case 0:
		sclass = SECCLASS_CAPABILITY;
		break;
	case 1:
		sclass = SECCLASS_CAPABILITY2;
		break;
	default:
		printk(KERN_ERR
		       "SELinux:  out of range capability %d\n", cap);
		BUG();
1500
		return -EINVAL;
1501
	}
1502

1503
	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1504 1505 1506 1507 1508
	if (audit == SECURITY_CAP_AUDIT) {
		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
		if (rc2)
			return rc2;
	}
1509
	return rc;
L
Linus Torvalds 已提交
1510 1511 1512 1513 1514 1515
}

/* Check whether a task is allowed to use a system operation. */
static int task_has_system(struct task_struct *tsk,
			   u32 perms)
{
1516
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
1517

1518
	return avc_has_perm(sid, SECINITSID_KERNEL,
L
Linus Torvalds 已提交
1519 1520 1521 1522 1523 1524
			    SECCLASS_SYSTEM, perms, NULL);
}

/* Check whether a task has a particular permission to an inode.
   The 'adp' parameter is optional and allows other audit
   data to be passed (e.g. the dentry). */
1525
static int inode_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1526 1527
			  struct inode *inode,
			  u32 perms,
1528 1529
			  struct common_audit_data *adp,
			  unsigned flags)
L
Linus Torvalds 已提交
1530 1531
{
	struct inode_security_struct *isec;
1532
	u32 sid;
L
Linus Torvalds 已提交
1533

1534 1535
	validate_creds(cred);

1536
	if (unlikely(IS_PRIVATE(inode)))
1537 1538
		return 0;

1539
	sid = cred_sid(cred);
L
Linus Torvalds 已提交
1540 1541
	isec = inode->i_security;

1542
	return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
L
Linus Torvalds 已提交
1543 1544 1545 1546 1547
}

/* Same as inode_has_perm, but pass explicit audit data containing
   the dentry to help the auditing code to more easily generate the
   pathname if needed. */
1548
static inline int dentry_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1549 1550 1551 1552
				  struct dentry *dentry,
				  u32 av)
{
	struct inode *inode = dentry->d_inode;
1553
	struct common_audit_data ad;
1554

1555
	ad.type = LSM_AUDIT_DATA_DENTRY;
E
Eric Paris 已提交
1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569
	ad.u.dentry = dentry;
	return inode_has_perm(cred, inode, av, &ad, 0);
}

/* Same as inode_has_perm, but pass explicit audit data containing
   the path to help the auditing code to more easily generate the
   pathname if needed. */
static inline int path_has_perm(const struct cred *cred,
				struct path *path,
				u32 av)
{
	struct inode *inode = path->dentry->d_inode;
	struct common_audit_data ad;

1570
	ad.type = LSM_AUDIT_DATA_PATH;
E
Eric Paris 已提交
1571
	ad.u.path = *path;
1572
	return inode_has_perm(cred, inode, av, &ad, 0);
L
Linus Torvalds 已提交
1573 1574
}

1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586
/* Same as path_has_perm, but uses the inode from the file struct. */
static inline int file_path_has_perm(const struct cred *cred,
				     struct file *file,
				     u32 av)
{
	struct common_audit_data ad;

	ad.type = LSM_AUDIT_DATA_PATH;
	ad.u.path = file->f_path;
	return inode_has_perm(cred, file_inode(file), av, &ad, 0);
}

L
Linus Torvalds 已提交
1587 1588 1589 1590 1591 1592 1593 1594
/* Check whether a task can use an open file descriptor to
   access an inode in a given way.  Check access to the
   descriptor itself, and then use dentry_has_perm to
   check a particular permission to the file.
   Access to the descriptor is implicitly granted if it
   has the same SID as the process.  If av is zero, then
   access to the file is not checked, e.g. for cases
   where only the descriptor is affected like seek. */
1595 1596 1597
static int file_has_perm(const struct cred *cred,
			 struct file *file,
			 u32 av)
L
Linus Torvalds 已提交
1598 1599
{
	struct file_security_struct *fsec = file->f_security;
A
Al Viro 已提交
1600
	struct inode *inode = file_inode(file);
1601
	struct common_audit_data ad;
1602
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1603 1604
	int rc;

1605
	ad.type = LSM_AUDIT_DATA_PATH;
1606
	ad.u.path = file->f_path;
L
Linus Torvalds 已提交
1607

1608 1609
	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid,
L
Linus Torvalds 已提交
1610 1611 1612 1613
				  SECCLASS_FD,
				  FD__USE,
				  &ad);
		if (rc)
1614
			goto out;
L
Linus Torvalds 已提交
1615 1616 1617
	}

	/* av is zero if only checking access to the descriptor. */
1618
	rc = 0;
L
Linus Torvalds 已提交
1619
	if (av)
1620
		rc = inode_has_perm(cred, inode, av, &ad, 0);
L
Linus Torvalds 已提交
1621

1622 1623
out:
	return rc;
L
Linus Torvalds 已提交
1624 1625 1626 1627 1628 1629 1630
}

/* Check whether a task can create a file. */
static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
1631
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
1632 1633
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
1634
	u32 sid, newsid;
1635
	struct common_audit_data ad;
L
Linus Torvalds 已提交
1636 1637 1638 1639 1640
	int rc;

	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

1641 1642 1643
	sid = tsec->sid;
	newsid = tsec->create_sid;

1644
	ad.type = LSM_AUDIT_DATA_DENTRY;
1645
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1646

1647
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1648 1649 1650 1651 1652
			  DIR__ADD_NAME | DIR__SEARCH,
			  &ad);
	if (rc)
		return rc;

1653
	if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
1654 1655
		rc = security_transition_sid(sid, dsec->sid, tclass,
					     &dentry->d_name, &newsid);
L
Linus Torvalds 已提交
1656 1657 1658 1659
		if (rc)
			return rc;
	}

1660
	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
L
Linus Torvalds 已提交
1661 1662 1663 1664 1665 1666 1667 1668
	if (rc)
		return rc;

	return avc_has_perm(newsid, sbsec->sid,
			    SECCLASS_FILESYSTEM,
			    FILESYSTEM__ASSOCIATE, &ad);
}

1669 1670 1671 1672
/* Check whether a task can create a key. */
static int may_create_key(u32 ksid,
			  struct task_struct *ctx)
{
1673
	u32 sid = task_sid(ctx);
1674

1675
	return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1676 1677
}

1678 1679 1680
#define MAY_LINK	0
#define MAY_UNLINK	1
#define MAY_RMDIR	2
L
Linus Torvalds 已提交
1681 1682 1683 1684 1685 1686 1687 1688

/* Check whether a task can link, unlink, or rmdir a file/directory. */
static int may_link(struct inode *dir,
		    struct dentry *dentry,
		    int kind)

{
	struct inode_security_struct *dsec, *isec;
1689
	struct common_audit_data ad;
1690
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1691 1692 1693 1694 1695 1696
	u32 av;
	int rc;

	dsec = dir->i_security;
	isec = dentry->d_inode->i_security;

1697
	ad.type = LSM_AUDIT_DATA_DENTRY;
1698
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1699 1700 1701

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1702
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716
	if (rc)
		return rc;

	switch (kind) {
	case MAY_LINK:
		av = FILE__LINK;
		break;
	case MAY_UNLINK:
		av = FILE__UNLINK;
		break;
	case MAY_RMDIR:
		av = DIR__RMDIR;
		break;
	default:
E
Eric Paris 已提交
1717 1718
		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
			__func__, kind);
L
Linus Torvalds 已提交
1719 1720 1721
		return 0;
	}

1722
	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
L
Linus Torvalds 已提交
1723 1724 1725 1726 1727 1728 1729 1730 1731
	return rc;
}

static inline int may_rename(struct inode *old_dir,
			     struct dentry *old_dentry,
			     struct inode *new_dir,
			     struct dentry *new_dentry)
{
	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1732
	struct common_audit_data ad;
1733
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1734 1735 1736 1737 1738 1739 1740 1741 1742
	u32 av;
	int old_is_dir, new_is_dir;
	int rc;

	old_dsec = old_dir->i_security;
	old_isec = old_dentry->d_inode->i_security;
	old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
	new_dsec = new_dir->i_security;

1743
	ad.type = LSM_AUDIT_DATA_DENTRY;
L
Linus Torvalds 已提交
1744

1745
	ad.u.dentry = old_dentry;
1746
	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1747 1748 1749
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
1750
	rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1751 1752 1753 1754
			  old_isec->sclass, FILE__RENAME, &ad);
	if (rc)
		return rc;
	if (old_is_dir && new_dir != old_dir) {
1755
		rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1756 1757 1758 1759 1760
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

1761
	ad.u.dentry = new_dentry;
L
Linus Torvalds 已提交
1762 1763 1764
	av = DIR__ADD_NAME | DIR__SEARCH;
	if (new_dentry->d_inode)
		av |= DIR__REMOVE_NAME;
1765
	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1766 1767 1768 1769 1770
	if (rc)
		return rc;
	if (new_dentry->d_inode) {
		new_isec = new_dentry->d_inode->i_security;
		new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1771
		rc = avc_has_perm(sid, new_isec->sid,
L
Linus Torvalds 已提交
1772 1773 1774 1775 1776 1777 1778 1779 1780 1781
				  new_isec->sclass,
				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
		if (rc)
			return rc;
	}

	return 0;
}

/* Check whether a task can perform a filesystem operation. */
1782
static int superblock_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1783 1784
			       struct super_block *sb,
			       u32 perms,
1785
			       struct common_audit_data *ad)
L
Linus Torvalds 已提交
1786 1787
{
	struct superblock_security_struct *sbsec;
1788
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1789 1790

	sbsec = sb->s_security;
1791
	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
L
Linus Torvalds 已提交
1792 1793 1794 1795 1796 1797 1798
}

/* Convert a Linux mode and permission mask to an access vector. */
static inline u32 file_mask_to_av(int mode, int mask)
{
	u32 av = 0;

A
Al Viro 已提交
1799
	if (!S_ISDIR(mode)) {
L
Linus Torvalds 已提交
1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821
		if (mask & MAY_EXEC)
			av |= FILE__EXECUTE;
		if (mask & MAY_READ)
			av |= FILE__READ;

		if (mask & MAY_APPEND)
			av |= FILE__APPEND;
		else if (mask & MAY_WRITE)
			av |= FILE__WRITE;

	} else {
		if (mask & MAY_EXEC)
			av |= DIR__SEARCH;
		if (mask & MAY_WRITE)
			av |= DIR__WRITE;
		if (mask & MAY_READ)
			av |= DIR__READ;
	}

	return av;
}

1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844
/* Convert a Linux file to an access vector. */
static inline u32 file_to_av(struct file *file)
{
	u32 av = 0;

	if (file->f_mode & FMODE_READ)
		av |= FILE__READ;
	if (file->f_mode & FMODE_WRITE) {
		if (file->f_flags & O_APPEND)
			av |= FILE__APPEND;
		else
			av |= FILE__WRITE;
	}
	if (!av) {
		/*
		 * Special file opened with flags 3 for ioctl-only use.
		 */
		av = FILE__IOCTL;
	}

	return av;
}

E
Eric Paris 已提交
1845
/*
1846
 * Convert a file to an access vector and include the correct open
E
Eric Paris 已提交
1847 1848
 * open permission.
 */
1849
static inline u32 open_file_to_av(struct file *file)
E
Eric Paris 已提交
1850
{
1851
	u32 av = file_to_av(file);
E
Eric Paris 已提交
1852

1853 1854 1855
	if (selinux_policycap_openperm)
		av |= FILE__OPEN;

E
Eric Paris 已提交
1856 1857 1858
	return av;
}

L
Linus Torvalds 已提交
1859 1860
/* Hook functions begin here. */

1861
static int selinux_ptrace_access_check(struct task_struct *child,
1862
				     unsigned int mode)
L
Linus Torvalds 已提交
1863 1864 1865
{
	int rc;

1866
	rc = cap_ptrace_access_check(child, mode);
L
Linus Torvalds 已提交
1867 1868 1869
	if (rc)
		return rc;

1870
	if (mode & PTRACE_MODE_READ) {
1871 1872 1873
		u32 sid = current_sid();
		u32 csid = task_sid(child);
		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1874 1875
	}

1876
	return current_has_perm(child, PROCESS__PTRACE);
1877 1878 1879 1880 1881 1882
}

static int selinux_ptrace_traceme(struct task_struct *parent)
{
	int rc;

1883
	rc = cap_ptrace_traceme(parent);
1884 1885 1886 1887
	if (rc)
		return rc;

	return task_has_perm(parent, current, PROCESS__PTRACE);
L
Linus Torvalds 已提交
1888 1889 1890
}

static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1891
			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
L
Linus Torvalds 已提交
1892 1893 1894
{
	int error;

1895
	error = current_has_perm(target, PROCESS__GETCAP);
L
Linus Torvalds 已提交
1896 1897 1898
	if (error)
		return error;

1899
	return cap_capget(target, effective, inheritable, permitted);
L
Linus Torvalds 已提交
1900 1901
}

D
David Howells 已提交
1902 1903 1904 1905
static int selinux_capset(struct cred *new, const struct cred *old,
			  const kernel_cap_t *effective,
			  const kernel_cap_t *inheritable,
			  const kernel_cap_t *permitted)
L
Linus Torvalds 已提交
1906 1907 1908
{
	int error;

1909
	error = cap_capset(new, old,
D
David Howells 已提交
1910
				      effective, inheritable, permitted);
L
Linus Torvalds 已提交
1911 1912 1913
	if (error)
		return error;

D
David Howells 已提交
1914
	return cred_has_perm(old, new, PROCESS__SETCAP);
L
Linus Torvalds 已提交
1915 1916
}

1917 1918 1919 1920 1921 1922 1923 1924 1925 1926
/*
 * (This comment used to live with the selinux_task_setuid hook,
 * which was removed).
 *
 * Since setuid only affects the current process, and since the SELinux
 * controls are not based on the Linux identity attributes, SELinux does not
 * need to control this operation.  However, SELinux does control the use of
 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
 */

1927 1928
static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
			   int cap, int audit)
L
Linus Torvalds 已提交
1929 1930 1931
{
	int rc;

1932
	rc = cap_capable(cred, ns, cap, audit);
L
Linus Torvalds 已提交
1933 1934 1935
	if (rc)
		return rc;

1936
	return cred_has_capability(cred, cap, audit);
L
Linus Torvalds 已提交
1937 1938 1939 1940
}

static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
{
1941
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
1942 1943 1944 1945 1946 1947
	int rc = 0;

	if (!sb)
		return 0;

	switch (cmds) {
1948 1949 1950 1951 1952
	case Q_SYNC:
	case Q_QUOTAON:
	case Q_QUOTAOFF:
	case Q_SETINFO:
	case Q_SETQUOTA:
1953
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1954 1955 1956 1957
		break;
	case Q_GETFMT:
	case Q_GETINFO:
	case Q_GETQUOTA:
1958
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1959 1960 1961 1962
		break;
	default:
		rc = 0;  /* let the kernel handle invalid cmds */
		break;
L
Linus Torvalds 已提交
1963 1964 1965 1966 1967 1968
	}
	return rc;
}

static int selinux_quota_on(struct dentry *dentry)
{
1969 1970
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
1971
	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
L
Linus Torvalds 已提交
1972 1973
}

1974
static int selinux_syslog(int type)
L
Linus Torvalds 已提交
1975 1976 1977 1978
{
	int rc;

	switch (type) {
1979 1980
	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
1981 1982
		rc = task_has_system(current, SYSTEM__SYSLOG_READ);
		break;
1983 1984 1985 1986
	case SYSLOG_ACTION_CONSOLE_OFF:	/* Disable logging to console */
	case SYSLOG_ACTION_CONSOLE_ON:	/* Enable logging to console */
	/* Set level of messages printed to console */
	case SYSLOG_ACTION_CONSOLE_LEVEL:
1987 1988
		rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
		break;
1989 1990 1991 1992 1993
	case SYSLOG_ACTION_CLOSE:	/* Close log */
	case SYSLOG_ACTION_OPEN:	/* Open log */
	case SYSLOG_ACTION_READ:	/* Read from log */
	case SYSLOG_ACTION_READ_CLEAR:	/* Read/clear last kernel messages */
	case SYSLOG_ACTION_CLEAR:	/* Clear ring buffer */
1994 1995 1996
	default:
		rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
		break;
L
Linus Torvalds 已提交
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
	}
	return rc;
}

/*
 * Check that a process has enough memory to allocate a new virtual
 * mapping. 0 means there is enough memory for the allocation to
 * succeed and -ENOMEM implies there is not.
 *
 * Do not audit the selinux permission check, as this is applied to all
 * processes that allocate mappings.
 */
2009
static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
L
Linus Torvalds 已提交
2010 2011 2012
{
	int rc, cap_sys_admin = 0;

2013
	rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
2014
			     SECURITY_CAP_NOAUDIT);
L
Linus Torvalds 已提交
2015 2016 2017
	if (rc == 0)
		cap_sys_admin = 1;

2018
	return __vm_enough_memory(mm, pages, cap_sys_admin);
L
Linus Torvalds 已提交
2019 2020 2021 2022
}

/* binprm security operations */

2023
static int selinux_bprm_set_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2024
{
2025 2026
	const struct task_security_struct *old_tsec;
	struct task_security_struct *new_tsec;
L
Linus Torvalds 已提交
2027
	struct inode_security_struct *isec;
2028
	struct common_audit_data ad;
A
Al Viro 已提交
2029
	struct inode *inode = file_inode(bprm->file);
L
Linus Torvalds 已提交
2030 2031
	int rc;

2032
	rc = cap_bprm_set_creds(bprm);
L
Linus Torvalds 已提交
2033 2034 2035
	if (rc)
		return rc;

2036 2037 2038
	/* SELinux context only depends on initial program or script and not
	 * the script interpreter */
	if (bprm->cred_prepared)
L
Linus Torvalds 已提交
2039 2040
		return 0;

2041 2042
	old_tsec = current_security();
	new_tsec = bprm->cred->security;
L
Linus Torvalds 已提交
2043 2044 2045
	isec = inode->i_security;

	/* Default to the current task SID. */
2046 2047
	new_tsec->sid = old_tsec->sid;
	new_tsec->osid = old_tsec->sid;
L
Linus Torvalds 已提交
2048

2049
	/* Reset fs, key, and sock SIDs on execve. */
2050 2051 2052
	new_tsec->create_sid = 0;
	new_tsec->keycreate_sid = 0;
	new_tsec->sockcreate_sid = 0;
L
Linus Torvalds 已提交
2053

2054 2055
	if (old_tsec->exec_sid) {
		new_tsec->sid = old_tsec->exec_sid;
L
Linus Torvalds 已提交
2056
		/* Reset exec SID on execve. */
2057
		new_tsec->exec_sid = 0;
2058 2059 2060 2061 2062 2063 2064

		/*
		 * Minimize confusion: if no_new_privs and a transition is
		 * explicitly requested, then fail the exec.
		 */
		if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
			return -EPERM;
L
Linus Torvalds 已提交
2065 2066
	} else {
		/* Check for a default transition on this program. */
2067
		rc = security_transition_sid(old_tsec->sid, isec->sid,
2068 2069
					     SECCLASS_PROCESS, NULL,
					     &new_tsec->sid);
L
Linus Torvalds 已提交
2070 2071 2072 2073
		if (rc)
			return rc;
	}

2074
	ad.type = LSM_AUDIT_DATA_PATH;
2075
	ad.u.path = bprm->file->f_path;
L
Linus Torvalds 已提交
2076

2077 2078
	if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) ||
	    (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS))
2079
		new_tsec->sid = old_tsec->sid;
L
Linus Torvalds 已提交
2080

2081 2082
	if (new_tsec->sid == old_tsec->sid) {
		rc = avc_has_perm(old_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2083 2084 2085 2086 2087
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		/* Check permissions for the transition. */
2088
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
L
Linus Torvalds 已提交
2089 2090 2091 2092
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

2093
		rc = avc_has_perm(new_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2094 2095 2096 2097
				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
		if (rc)
			return rc;

2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115
		/* Check for shared state */
		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
					  SECCLASS_PROCESS, PROCESS__SHARE,
					  NULL);
			if (rc)
				return -EPERM;
		}

		/* Make sure that anyone attempting to ptrace over a task that
		 * changes its SID has the appropriate permit */
		if (bprm->unsafe &
		    (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
			struct task_struct *tracer;
			struct task_security_struct *sec;
			u32 ptsid = 0;

			rcu_read_lock();
2116
			tracer = ptrace_parent(current);
2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130
			if (likely(tracer != NULL)) {
				sec = __task_cred(tracer)->security;
				ptsid = sec->sid;
			}
			rcu_read_unlock();

			if (ptsid != 0) {
				rc = avc_has_perm(ptsid, new_tsec->sid,
						  SECCLASS_PROCESS,
						  PROCESS__PTRACE, NULL);
				if (rc)
					return -EPERM;
			}
		}
L
Linus Torvalds 已提交
2131

2132 2133
		/* Clear any possibly unsafe personality bits on exec: */
		bprm->per_clear |= PER_CLEAR_ON_SETID;
L
Linus Torvalds 已提交
2134 2135 2136 2137 2138
	}

	return 0;
}

2139
static int selinux_bprm_secureexec(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2140
{
2141
	const struct task_security_struct *tsec = current_security();
2142
	u32 sid, osid;
L
Linus Torvalds 已提交
2143 2144
	int atsecure = 0;

2145 2146 2147 2148
	sid = tsec->sid;
	osid = tsec->osid;

	if (osid != sid) {
L
Linus Torvalds 已提交
2149 2150 2151
		/* Enable secure mode for SIDs transitions unless
		   the noatsecure permission is granted between
		   the two SIDs, i.e. ahp returns 0. */
2152
		atsecure = avc_has_perm(osid, sid,
2153 2154
					SECCLASS_PROCESS,
					PROCESS__NOATSECURE, NULL);
L
Linus Torvalds 已提交
2155 2156
	}

2157
	return (atsecure || cap_bprm_secureexec(bprm));
L
Linus Torvalds 已提交
2158 2159
}

A
Al Viro 已提交
2160 2161 2162 2163 2164
static int match_file(const void *p, struct file *file, unsigned fd)
{
	return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
}

L
Linus Torvalds 已提交
2165
/* Derived from fs/exec.c:flush_old_files. */
2166 2167
static inline void flush_unauthorized_files(const struct cred *cred,
					    struct files_struct *files)
L
Linus Torvalds 已提交
2168 2169
{
	struct file *file, *devnull = NULL;
2170
	struct tty_struct *tty;
2171
	int drop_tty = 0;
A
Al Viro 已提交
2172
	unsigned n;
L
Linus Torvalds 已提交
2173

2174
	tty = get_current_tty();
L
Linus Torvalds 已提交
2175
	if (tty) {
N
Nick Piggin 已提交
2176
		spin_lock(&tty_files_lock);
2177
		if (!list_empty(&tty->tty_files)) {
N
Nick Piggin 已提交
2178
			struct tty_file_private *file_priv;
2179

L
Linus Torvalds 已提交
2180
			/* Revalidate access to controlling tty.
2181 2182 2183 2184
			   Use file_path_has_perm on the tty path directly
			   rather than using file_has_perm, as this particular
			   open file may belong to another process and we are
			   only interested in the inode-based check here. */
N
Nick Piggin 已提交
2185 2186 2187
			file_priv = list_first_entry(&tty->tty_files,
						struct tty_file_private, list);
			file = file_priv->file;
2188
			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2189
				drop_tty = 1;
L
Linus Torvalds 已提交
2190
		}
N
Nick Piggin 已提交
2191
		spin_unlock(&tty_files_lock);
A
Alan Cox 已提交
2192
		tty_kref_put(tty);
L
Linus Torvalds 已提交
2193
	}
2194 2195 2196
	/* Reset controlling tty. */
	if (drop_tty)
		no_tty();
L
Linus Torvalds 已提交
2197 2198

	/* Revalidate access to inherited open files. */
A
Al Viro 已提交
2199 2200 2201
	n = iterate_fd(files, 0, match_file, cred);
	if (!n) /* none found? */
		return;
L
Linus Torvalds 已提交
2202

A
Al Viro 已提交
2203
	devnull = dentry_open(&selinux_null, O_RDWR, cred);
A
Al Viro 已提交
2204 2205 2206 2207 2208 2209 2210
	if (IS_ERR(devnull))
		devnull = NULL;
	/* replace all the matching ones with this */
	do {
		replace_fd(n - 1, devnull, 0);
	} while ((n = iterate_fd(files, n, match_file, cred)) != 0);
	if (devnull)
A
Al Viro 已提交
2211
		fput(devnull);
L
Linus Torvalds 已提交
2212 2213
}

2214 2215 2216 2217
/*
 * Prepare a process for imminent new credential changes due to exec
 */
static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2218
{
2219 2220 2221
	struct task_security_struct *new_tsec;
	struct rlimit *rlim, *initrlim;
	int rc, i;
D
David Howells 已提交
2222

2223 2224 2225
	new_tsec = bprm->cred->security;
	if (new_tsec->sid == new_tsec->osid)
		return;
L
Linus Torvalds 已提交
2226

2227 2228
	/* Close files for which the new task SID is not authorized. */
	flush_unauthorized_files(bprm->cred, current->files);
R
Roland McGrath 已提交
2229

2230 2231
	/* Always clear parent death signal on SID transitions. */
	current->pdeath_signal = 0;
R
Roland McGrath 已提交
2232

2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245
	/* Check whether the new SID can inherit resource limits from the old
	 * SID.  If not, reset all soft limits to the lower of the current
	 * task's hard limit and the init task's soft limit.
	 *
	 * Note that the setting of hard limits (even to lower them) can be
	 * controlled by the setrlimit check.  The inclusion of the init task's
	 * soft limit into the computation is to avoid resetting soft limits
	 * higher than the default soft limit for cases where the default is
	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
	 */
	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
			  PROCESS__RLIMITINH, NULL);
	if (rc) {
2246 2247
		/* protect against do_prlimit() */
		task_lock(current);
2248 2249 2250 2251
		for (i = 0; i < RLIM_NLIMITS; i++) {
			rlim = current->signal->rlim + i;
			initrlim = init_task.signal->rlim + i;
			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
L
Linus Torvalds 已提交
2252
		}
2253 2254
		task_unlock(current);
		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
L
Linus Torvalds 已提交
2255 2256 2257 2258
	}
}

/*
2259 2260
 * Clean up the process immediately after the installation of new credentials
 * due to exec
L
Linus Torvalds 已提交
2261
 */
2262
static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2263
{
2264
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
2265
	struct itimerval itimer;
2266
	u32 osid, sid;
L
Linus Torvalds 已提交
2267 2268
	int rc, i;

2269 2270 2271 2272
	osid = tsec->osid;
	sid = tsec->sid;

	if (sid == osid)
L
Linus Torvalds 已提交
2273 2274
		return;

2275 2276 2277 2278 2279 2280 2281 2282
	/* Check whether the new SID can inherit signal state from the old SID.
	 * If not, clear itimers to avoid subsequent signal generation and
	 * flush and unblock signals.
	 *
	 * This must occur _after_ the task SID has been updated so that any
	 * kill done after the flush will be checked against the new SID.
	 */
	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
L
Linus Torvalds 已提交
2283 2284 2285 2286 2287
	if (rc) {
		memset(&itimer, 0, sizeof itimer);
		for (i = 0; i < 3; i++)
			do_setitimer(i, &itimer, NULL);
		spin_lock_irq(&current->sighand->siglock);
2288 2289 2290 2291 2292
		if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
			__flush_signals(current);
			flush_signal_handlers(current, 1);
			sigemptyset(&current->blocked);
		}
L
Linus Torvalds 已提交
2293 2294 2295
		spin_unlock_irq(&current->sighand->siglock);
	}

2296 2297
	/* Wake up the parent if it is waiting so that it can recheck
	 * wait permission to the new task SID. */
2298
	read_lock(&tasklist_lock);
2299
	__wake_up_parent(current, current->real_parent);
2300
	read_unlock(&tasklist_lock);
L
Linus Torvalds 已提交
2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324
}

/* superblock security operations */

static int selinux_sb_alloc_security(struct super_block *sb)
{
	return superblock_alloc_security(sb);
}

static void selinux_sb_free_security(struct super_block *sb)
{
	superblock_free_security(sb);
}

static inline int match_prefix(char *prefix, int plen, char *option, int olen)
{
	if (plen > olen)
		return 0;

	return !memcmp(prefix, option, plen);
}

static inline int selinux_option(char *option, int len)
{
2325 2326 2327
	return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
		match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
		match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2328 2329
		match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
		match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
L
Linus Torvalds 已提交
2330 2331 2332 2333 2334 2335 2336
}

static inline void take_option(char **to, char *from, int *first, int len)
{
	if (!*first) {
		**to = ',';
		*to += 1;
2337
	} else
L
Linus Torvalds 已提交
2338 2339 2340 2341 2342
		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}

2343 2344
static inline void take_selinux_option(char **to, char *from, int *first,
				       int len)
2345 2346 2347 2348 2349 2350
{
	int current_size = 0;

	if (!*first) {
		**to = '|';
		*to += 1;
2351
	} else
2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363
		*first = 0;

	while (current_size < len) {
		if (*from != '"') {
			**to = *from;
			*to += 1;
		}
		from += 1;
		current_size += 1;
	}
}

2364
static int selinux_sb_copy_data(char *orig, char *copy)
L
Linus Torvalds 已提交
2365 2366 2367 2368
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_curr, *in_end;
	char *sec_curr, *nosec_save, *nosec;
2369
	int open_quote = 0;
L
Linus Torvalds 已提交
2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384

	in_curr = orig;
	sec_curr = copy;

	nosec = (char *)get_zeroed_page(GFP_KERNEL);
	if (!nosec) {
		rc = -ENOMEM;
		goto out;
	}

	nosec_save = nosec;
	fnosec = fsec = 1;
	in_save = in_end = orig;

	do {
2385 2386 2387 2388
		if (*in_end == '"')
			open_quote = !open_quote;
		if ((*in_end == ',' && open_quote == 0) ||
				*in_end == '\0') {
L
Linus Torvalds 已提交
2389 2390 2391
			int len = in_end - in_curr;

			if (selinux_option(in_curr, len))
2392
				take_selinux_option(&sec_curr, in_curr, &fsec, len);
L
Linus Torvalds 已提交
2393 2394 2395 2396 2397 2398 2399
			else
				take_option(&nosec, in_curr, &fnosec, len);

			in_curr = in_end + 1;
		}
	} while (*in_end++);

2400
	strcpy(in_save, nosec_save);
2401
	free_page((unsigned long)nosec_save);
L
Linus Torvalds 已提交
2402 2403 2404 2405
out:
	return rc;
}

2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490
static int selinux_sb_remount(struct super_block *sb, void *data)
{
	int rc, i, *flags;
	struct security_mnt_opts opts;
	char *secdata, **mount_options;
	struct superblock_security_struct *sbsec = sb->s_security;

	if (!(sbsec->flags & SE_SBINITIALIZED))
		return 0;

	if (!data)
		return 0;

	if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
		return 0;

	security_init_mnt_opts(&opts);
	secdata = alloc_secdata();
	if (!secdata)
		return -ENOMEM;
	rc = selinux_sb_copy_data(data, secdata);
	if (rc)
		goto out_free_secdata;

	rc = selinux_parse_opts_str(secdata, &opts);
	if (rc)
		goto out_free_secdata;

	mount_options = opts.mnt_opts;
	flags = opts.mnt_opts_flags;

	for (i = 0; i < opts.num_mnt_opts; i++) {
		u32 sid;
		size_t len;

		if (flags[i] == SE_SBLABELSUPP)
			continue;
		len = strlen(mount_options[i]);
		rc = security_context_to_sid(mount_options[i], len, &sid);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, sb->s_type->name, rc);
			goto out_free_opts;
		}
		rc = -EINVAL;
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
				goto out_bad_option;
			break;
		case CONTEXT_MNT:
			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
				goto out_bad_option;
			break;
		case ROOTCONTEXT_MNT: {
			struct inode_security_struct *root_isec;
			root_isec = sb->s_root->d_inode->i_security;

			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
				goto out_bad_option;
			break;
		}
		case DEFCONTEXT_MNT:
			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
				goto out_bad_option;
			break;
		default:
			goto out_free_opts;
		}
	}

	rc = 0;
out_free_opts:
	security_free_mnt_opts(&opts);
out_free_secdata:
	free_secdata(secdata);
	return rc;
out_bad_option:
	printk(KERN_WARNING "SELinux: unable to change security options "
	       "during remount (dev %s, type=%s)\n", sb->s_id,
	       sb->s_type->name);
	goto out_free_opts;
}

2491
static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
L
Linus Torvalds 已提交
2492
{
2493
	const struct cred *cred = current_cred();
2494
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2495 2496 2497 2498 2499 2500
	int rc;

	rc = superblock_doinit(sb, data);
	if (rc)
		return rc;

2501 2502 2503 2504
	/* Allow all mounts performed by the kernel */
	if (flags & MS_KERNMOUNT)
		return 0;

2505
	ad.type = LSM_AUDIT_DATA_DENTRY;
2506
	ad.u.dentry = sb->s_root;
2507
	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
L
Linus Torvalds 已提交
2508 2509
}

2510
static int selinux_sb_statfs(struct dentry *dentry)
L
Linus Torvalds 已提交
2511
{
2512
	const struct cred *cred = current_cred();
2513
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2514

2515
	ad.type = LSM_AUDIT_DATA_DENTRY;
2516
	ad.u.dentry = dentry->d_sb->s_root;
2517
	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
L
Linus Torvalds 已提交
2518 2519
}

A
Al Viro 已提交
2520
static int selinux_mount(const char *dev_name,
2521
			 struct path *path,
A
Al Viro 已提交
2522
			 const char *type,
2523 2524
			 unsigned long flags,
			 void *data)
L
Linus Torvalds 已提交
2525
{
2526
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2527 2528

	if (flags & MS_REMOUNT)
2529
		return superblock_has_perm(cred, path->dentry->d_sb,
2530
					   FILESYSTEM__REMOUNT, NULL);
L
Linus Torvalds 已提交
2531
	else
E
Eric Paris 已提交
2532
		return path_has_perm(cred, path, FILE__MOUNTON);
L
Linus Torvalds 已提交
2533 2534 2535 2536
}

static int selinux_umount(struct vfsmount *mnt, int flags)
{
2537
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2538

2539
	return superblock_has_perm(cred, mnt->mnt_sb,
2540
				   FILESYSTEM__UNMOUNT, NULL);
L
Linus Torvalds 已提交
2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554
}

/* inode security operations */

static int selinux_inode_alloc_security(struct inode *inode)
{
	return inode_alloc_security(inode);
}

static void selinux_inode_free_security(struct inode *inode)
{
	inode_free_security(inode);
}

2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588
static int selinux_dentry_init_security(struct dentry *dentry, int mode,
					struct qstr *name, void **ctx,
					u32 *ctxlen)
{
	const struct cred *cred = current_cred();
	struct task_security_struct *tsec;
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
	struct inode *dir = dentry->d_parent->d_inode;
	u32 newsid;
	int rc;

	tsec = cred->security;
	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
		newsid = tsec->create_sid;
	} else {
		rc = security_transition_sid(tsec->sid, dsec->sid,
					     inode_mode_to_security_class(mode),
					     name,
					     &newsid);
		if (rc) {
			printk(KERN_WARNING
				"%s: security_transition_sid failed, rc=%d\n",
			       __func__, -rc);
			return rc;
		}
	}

	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
}

2589
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2590 2591
				       const struct qstr *qstr,
				       const char **name,
2592
				       void **value, size_t *len)
2593
{
2594
	const struct task_security_struct *tsec = current_security();
2595 2596
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
2597
	u32 sid, newsid, clen;
2598
	int rc;
2599
	char *context;
2600 2601 2602 2603

	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

2604 2605 2606
	sid = tsec->sid;
	newsid = tsec->create_sid;

2607 2608 2609 2610
	if ((sbsec->flags & SE_SBINITIALIZED) &&
	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
		newsid = sbsec->mntpoint_sid;
	else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2611
		rc = security_transition_sid(sid, dsec->sid,
2612
					     inode_mode_to_security_class(inode->i_mode),
2613
					     qstr, &newsid);
2614 2615 2616 2617
		if (rc) {
			printk(KERN_WARNING "%s:  "
			       "security_transition_sid failed, rc=%d (dev=%s "
			       "ino=%ld)\n",
2618
			       __func__,
2619 2620 2621 2622 2623
			       -rc, inode->i_sb->s_id, inode->i_ino);
			return rc;
		}
	}

2624
	/* Possibly defer initialization to selinux_complete_init. */
2625
	if (sbsec->flags & SE_SBINITIALIZED) {
2626 2627 2628 2629 2630
		struct inode_security_struct *isec = inode->i_security;
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		isec->sid = newsid;
		isec->initialized = 1;
	}
2631

2632
	if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2633 2634
		return -EOPNOTSUPP;

2635 2636
	if (name)
		*name = XATTR_SELINUX_SUFFIX;
2637

2638
	if (value && len) {
2639
		rc = security_sid_to_context_force(newsid, &context, &clen);
2640
		if (rc)
2641 2642 2643
			return rc;
		*value = context;
		*len = clen;
2644 2645 2646 2647 2648
	}

	return 0;
}

A
Al Viro 已提交
2649
static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668
{
	return may_create(dir, dentry, SECCLASS_FILE);
}

static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
{
	return may_link(dir, old_dentry, MAY_LINK);
}

static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
{
	return may_link(dir, dentry, MAY_UNLINK);
}

static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
{
	return may_create(dir, dentry, SECCLASS_LNK_FILE);
}

2669
static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
L
Linus Torvalds 已提交
2670 2671 2672 2673 2674 2675 2676 2677 2678
{
	return may_create(dir, dentry, SECCLASS_DIR);
}

static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
{
	return may_link(dir, dentry, MAY_RMDIR);
}

A
Al Viro 已提交
2679
static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
L
Linus Torvalds 已提交
2680 2681 2682 2683 2684
{
	return may_create(dir, dentry, inode_mode_to_security_class(mode));
}

static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2685
				struct inode *new_inode, struct dentry *new_dentry)
L
Linus Torvalds 已提交
2686 2687 2688 2689 2690 2691
{
	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
}

static int selinux_inode_readlink(struct dentry *dentry)
{
2692 2693
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2694
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
2695 2696 2697 2698
}

static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
{
2699
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2700

E
Eric Paris 已提交
2701
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
2702 2703
}

2704 2705 2706
static noinline int audit_inode_permission(struct inode *inode,
					   u32 perms, u32 audited, u32 denied,
					   unsigned flags)
L
Linus Torvalds 已提交
2707
{
2708
	struct common_audit_data ad;
2709 2710 2711
	struct inode_security_struct *isec = inode->i_security;
	int rc;

2712
	ad.type = LSM_AUDIT_DATA_INODE;
2713 2714 2715 2716 2717 2718 2719 2720 2721
	ad.u.inode = inode;

	rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
			    audited, denied, &ad, flags);
	if (rc)
		return rc;
	return 0;
}

2722
static int selinux_inode_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
2723
{
2724
	const struct cred *cred = current_cred();
2725 2726
	u32 perms;
	bool from_access;
2727
	unsigned flags = mask & MAY_NOT_BLOCK;
2728 2729 2730 2731 2732
	struct inode_security_struct *isec;
	u32 sid;
	struct av_decision avd;
	int rc, rc2;
	u32 audited, denied;
L
Linus Torvalds 已提交
2733

2734
	from_access = mask & MAY_ACCESS;
2735 2736
	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);

2737 2738
	/* No permission to check.  Existence test. */
	if (!mask)
L
Linus Torvalds 已提交
2739 2740
		return 0;

2741
	validate_creds(cred);
2742

2743 2744
	if (unlikely(IS_PRIVATE(inode)))
		return 0;
2745 2746 2747

	perms = file_mask_to_av(inode->i_mode, mask);

2748 2749 2750 2751 2752 2753 2754 2755 2756 2757
	sid = cred_sid(cred);
	isec = inode->i_security;

	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
	audited = avc_audit_required(perms, &avd, rc,
				     from_access ? FILE__AUDIT_ACCESS : 0,
				     &denied);
	if (likely(!audited))
		return rc;

2758
	rc2 = audit_inode_permission(inode, perms, audited, denied, flags);
2759 2760 2761
	if (rc2)
		return rc2;
	return rc;
L
Linus Torvalds 已提交
2762 2763 2764 2765
}

static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
2766
	const struct cred *cred = current_cred();
2767
	unsigned int ia_valid = iattr->ia_valid;
2768
	__u32 av = FILE__WRITE;
L
Linus Torvalds 已提交
2769

2770 2771 2772 2773 2774 2775 2776
	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
	if (ia_valid & ATTR_FORCE) {
		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
			      ATTR_FORCE);
		if (!ia_valid)
			return 0;
	}
L
Linus Torvalds 已提交
2777

2778 2779
	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
E
Eric Paris 已提交
2780
		return dentry_has_perm(cred, dentry, FILE__SETATTR);
L
Linus Torvalds 已提交
2781

2782
	if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE))
2783 2784 2785
		av |= FILE__OPEN;

	return dentry_has_perm(cred, dentry, av);
L
Linus Torvalds 已提交
2786 2787 2788 2789
}

static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
2790
	const struct cred *cred = current_cred();
E
Eric Paris 已提交
2791 2792 2793 2794
	struct path path;

	path.dentry = dentry;
	path.mnt = mnt;
2795

E
Eric Paris 已提交
2796
	return path_has_perm(cred, &path, FILE__GETATTR);
L
Linus Torvalds 已提交
2797 2798
}

2799
static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2800
{
2801 2802
	const struct cred *cred = current_cred();

2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816
	if (!strncmp(name, XATTR_SECURITY_PREFIX,
		     sizeof XATTR_SECURITY_PREFIX - 1)) {
		if (!strcmp(name, XATTR_NAME_CAPS)) {
			if (!capable(CAP_SETFCAP))
				return -EPERM;
		} else if (!capable(CAP_SYS_ADMIN)) {
			/* A different attribute in the security namespace.
			   Restrict to administrator. */
			return -EPERM;
		}
	}

	/* Not an attribute we recognize, so just check the
	   ordinary setattr permission. */
E
Eric Paris 已提交
2817
	return dentry_has_perm(cred, dentry, FILE__SETATTR);
2818 2819
}

2820 2821
static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
				  const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
2822 2823 2824 2825
{
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec;
2826
	struct common_audit_data ad;
2827
	u32 newsid, sid = current_sid();
L
Linus Torvalds 已提交
2828 2829
	int rc = 0;

2830 2831
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
2832 2833

	sbsec = inode->i_sb->s_security;
2834
	if (!(sbsec->flags & SE_SBLABELSUPP))
L
Linus Torvalds 已提交
2835 2836
		return -EOPNOTSUPP;

2837
	if (!inode_owner_or_capable(inode))
L
Linus Torvalds 已提交
2838 2839
		return -EPERM;

2840
	ad.type = LSM_AUDIT_DATA_DENTRY;
2841
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
2842

2843
	rc = avc_has_perm(sid, isec->sid, isec->sclass,
L
Linus Torvalds 已提交
2844 2845 2846 2847 2848
			  FILE__RELABELFROM, &ad);
	if (rc)
		return rc;

	rc = security_context_to_sid(value, size, &newsid);
2849
	if (rc == -EINVAL) {
2850 2851 2852 2853 2854 2855 2856
		if (!capable(CAP_MAC_ADMIN)) {
			struct audit_buffer *ab;
			size_t audit_size;
			const char *str;

			/* We strip a nul only if it is at the end, otherwise the
			 * context contains a nul and we should audit that */
2857 2858 2859 2860 2861 2862 2863 2864 2865 2866
			if (value) {
				str = value;
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
			} else {
				str = "";
				audit_size = 0;
			}
2867 2868 2869 2870 2871
			ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
			audit_log_format(ab, "op=setxattr invalid_context=");
			audit_log_n_untrustedstring(ab, value, audit_size);
			audit_log_end(ab);

2872
			return rc;
2873
		}
2874 2875
		rc = security_context_to_sid_force(value, size, &newsid);
	}
L
Linus Torvalds 已提交
2876 2877 2878
	if (rc)
		return rc;

2879
	rc = avc_has_perm(sid, newsid, isec->sclass,
L
Linus Torvalds 已提交
2880 2881 2882 2883
			  FILE__RELABELTO, &ad);
	if (rc)
		return rc;

2884
	rc = security_validate_transition(isec->sid, newsid, sid,
2885
					  isec->sclass);
L
Linus Torvalds 已提交
2886 2887 2888 2889 2890 2891 2892 2893 2894 2895
	if (rc)
		return rc;

	return avc_has_perm(newsid,
			    sbsec->sid,
			    SECCLASS_FILESYSTEM,
			    FILESYSTEM__ASSOCIATE,
			    &ad);
}

2896
static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2897
					const void *value, size_t size,
2898
					int flags)
L
Linus Torvalds 已提交
2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909
{
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	u32 newsid;
	int rc;

	if (strcmp(name, XATTR_NAME_SELINUX)) {
		/* Not an attribute we recognize, so nothing to do. */
		return;
	}

2910
	rc = security_context_to_sid_force(value, size, &newsid);
L
Linus Torvalds 已提交
2911
	if (rc) {
2912 2913 2914
		printk(KERN_ERR "SELinux:  unable to map context to SID"
		       "for (%s, %lu), rc=%d\n",
		       inode->i_sb->s_id, inode->i_ino, -rc);
L
Linus Torvalds 已提交
2915 2916 2917
		return;
	}

2918
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
2919
	isec->sid = newsid;
2920 2921
	isec->initialized = 1;

L
Linus Torvalds 已提交
2922 2923 2924
	return;
}

2925
static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
2926
{
2927 2928
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2929
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
2930 2931
}

2932
static int selinux_inode_listxattr(struct dentry *dentry)
L
Linus Torvalds 已提交
2933
{
2934 2935
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2936
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
2937 2938
}

2939
static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
2940
{
2941 2942
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
2943 2944 2945 2946 2947 2948

	/* No one is allowed to remove a SELinux security label.
	   You can change the label, but all data must be labeled. */
	return -EACCES;
}

2949
/*
2950
 * Copy the inode security context value to the user.
2951 2952 2953
 *
 * Permission check is handled by selinux_inode_getxattr hook.
 */
2954
static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
L
Linus Torvalds 已提交
2955
{
2956 2957 2958
	u32 size;
	int error;
	char *context = NULL;
L
Linus Torvalds 已提交
2959
	struct inode_security_struct *isec = inode->i_security;
2960

2961 2962
	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;
2963

2964 2965 2966 2967 2968 2969 2970 2971 2972
	/*
	 * If the caller has CAP_MAC_ADMIN, then get the raw context
	 * value even if it is not defined by current policy; otherwise,
	 * use the in-core value under current policy.
	 * Use the non-auditing forms of the permission checks since
	 * getxattr may be called by unprivileged processes commonly
	 * and lack of permission just means that we fall back to the
	 * in-core context value, not a denial.
	 */
2973
	error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
2974
				SECURITY_CAP_NOAUDIT);
2975 2976 2977 2978 2979
	if (!error)
		error = security_sid_to_context_force(isec->sid, &context,
						      &size);
	else
		error = security_sid_to_context(isec->sid, &context, &size);
2980 2981 2982 2983 2984 2985 2986 2987 2988 2989
	if (error)
		return error;
	error = size;
	if (alloc) {
		*buffer = context;
		goto out_nofree;
	}
	kfree(context);
out_nofree:
	return error;
L
Linus Torvalds 已提交
2990 2991 2992
}

static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2993
				     const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004
{
	struct inode_security_struct *isec = inode->i_security;
	u32 newsid;
	int rc;

	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;

	if (!value || !size)
		return -EACCES;

3005
	rc = security_context_to_sid((void *)value, size, &newsid);
L
Linus Torvalds 已提交
3006 3007 3008
	if (rc)
		return rc;

3009
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
3010
	isec->sid = newsid;
3011
	isec->initialized = 1;
L
Linus Torvalds 已提交
3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022
	return 0;
}

static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
{
	const int len = sizeof(XATTR_NAME_SELINUX);
	if (buffer && len <= buffer_size)
		memcpy(buffer, XATTR_NAME_SELINUX, len);
	return len;
}

3023 3024 3025 3026 3027 3028
static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
{
	struct inode_security_struct *isec = inode->i_security;
	*secid = isec->sid;
}

L
Linus Torvalds 已提交
3029 3030
/* file security operations */

3031
static int selinux_revalidate_file_permission(struct file *file, int mask)
L
Linus Torvalds 已提交
3032
{
3033
	const struct cred *cred = current_cred();
A
Al Viro 已提交
3034
	struct inode *inode = file_inode(file);
L
Linus Torvalds 已提交
3035 3036 3037 3038 3039

	/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
		mask |= MAY_APPEND;

3040 3041
	return file_has_perm(cred, file,
			     file_mask_to_av(inode->i_mode, mask));
L
Linus Torvalds 已提交
3042 3043
}

3044 3045
static int selinux_file_permission(struct file *file, int mask)
{
A
Al Viro 已提交
3046
	struct inode *inode = file_inode(file);
3047 3048 3049 3050
	struct file_security_struct *fsec = file->f_security;
	struct inode_security_struct *isec = inode->i_security;
	u32 sid = current_sid();

3051
	if (!mask)
3052 3053 3054
		/* No permission to check.  Existence test. */
		return 0;

3055 3056
	if (sid == fsec->sid && fsec->isid == isec->sid &&
	    fsec->pseqno == avc_policy_seqno())
3057
		/* No change since file_open check. */
3058 3059
		return 0;

3060 3061 3062
	return selinux_revalidate_file_permission(file, mask);
}

L
Linus Torvalds 已提交
3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075
static int selinux_file_alloc_security(struct file *file)
{
	return file_alloc_security(file);
}

static void selinux_file_free_security(struct file *file)
{
	file_free_security(file);
}

static int selinux_file_ioctl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3076
	const struct cred *cred = current_cred();
3077
	int error = 0;
L
Linus Torvalds 已提交
3078

3079 3080 3081 3082 3083 3084 3085
	switch (cmd) {
	case FIONREAD:
	/* fall through */
	case FIBMAP:
	/* fall through */
	case FIGETBSZ:
	/* fall through */
3086
	case FS_IOC_GETFLAGS:
3087
	/* fall through */
3088
	case FS_IOC_GETVERSION:
3089 3090
		error = file_has_perm(cred, file, FILE__GETATTR);
		break;
L
Linus Torvalds 已提交
3091

3092
	case FS_IOC_SETFLAGS:
3093
	/* fall through */
3094
	case FS_IOC_SETVERSION:
3095 3096 3097 3098 3099 3100 3101 3102 3103
		error = file_has_perm(cred, file, FILE__SETATTR);
		break;

	/* sys_ioctl() checks */
	case FIONBIO:
	/* fall through */
	case FIOASYNC:
		error = file_has_perm(cred, file, 0);
		break;
L
Linus Torvalds 已提交
3104

3105 3106
	case KDSKBENT:
	case KDSKBSENT:
3107 3108
		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
					    SECURITY_CAP_AUDIT);
3109 3110 3111 3112 3113 3114 3115 3116 3117
		break;

	/* default case assumes that the command will go
	 * to the file's ioctl() function.
	 */
	default:
		error = file_has_perm(cred, file, FILE__IOCTL);
	}
	return error;
L
Linus Torvalds 已提交
3118 3119
}

3120 3121
static int default_noexec;

L
Linus Torvalds 已提交
3122 3123
static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
3124
	const struct cred *cred = current_cred();
D
David Howells 已提交
3125
	int rc = 0;
3126

3127 3128
	if (default_noexec &&
	    (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
L
Linus Torvalds 已提交
3129 3130 3131 3132 3133
		/*
		 * We are making executable an anonymous mapping or a
		 * private file mapping that will also be writable.
		 * This has an additional check.
		 */
D
David Howells 已提交
3134
		rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
L
Linus Torvalds 已提交
3135
		if (rc)
D
David Howells 已提交
3136
			goto error;
L
Linus Torvalds 已提交
3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149
	}

	if (file) {
		/* read access is always possible with a mapping */
		u32 av = FILE__READ;

		/* write access only matters if the mapping is shared */
		if (shared && (prot & PROT_WRITE))
			av |= FILE__WRITE;

		if (prot & PROT_EXEC)
			av |= FILE__EXECUTE;

3150
		return file_has_perm(cred, file, av);
L
Linus Torvalds 已提交
3151
	}
D
David Howells 已提交
3152 3153 3154

error:
	return rc;
L
Linus Torvalds 已提交
3155 3156
}

3157
static int selinux_mmap_addr(unsigned long addr)
L
Linus Torvalds 已提交
3158
{
3159
	int rc = 0;
3160
	u32 sid = current_sid();
L
Linus Torvalds 已提交
3161

3162 3163 3164 3165 3166 3167
	/*
	 * notice that we are intentionally putting the SELinux check before
	 * the secondary cap_file_mmap check.  This is such a likely attempt
	 * at bad behaviour/exploit that we always want to get the AVC, even
	 * if DAC would have also denied the operation.
	 */
3168
	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3169 3170
		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
				  MEMPROTECT__MMAP_ZERO, NULL);
3171 3172 3173 3174 3175
		if (rc)
			return rc;
	}

	/* do DAC check on address space usage */
3176 3177
	return cap_mmap_addr(addr);
}
L
Linus Torvalds 已提交
3178

3179 3180 3181
static int selinux_mmap_file(struct file *file, unsigned long reqprot,
			     unsigned long prot, unsigned long flags)
{
L
Linus Torvalds 已提交
3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192
	if (selinux_checkreqprot)
		prot = reqprot;

	return file_map_prot_check(file, prot,
				   (flags & MAP_TYPE) == MAP_SHARED);
}

static int selinux_file_mprotect(struct vm_area_struct *vma,
				 unsigned long reqprot,
				 unsigned long prot)
{
3193
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3194 3195 3196 3197

	if (selinux_checkreqprot)
		prot = reqprot;

3198 3199
	if (default_noexec &&
	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3200
		int rc = 0;
3201 3202
		if (vma->vm_start >= vma->vm_mm->start_brk &&
		    vma->vm_end <= vma->vm_mm->brk) {
D
David Howells 已提交
3203
			rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3204 3205 3206
		} else if (!vma->vm_file &&
			   vma->vm_start <= vma->vm_mm->start_stack &&
			   vma->vm_end >= vma->vm_mm->start_stack) {
3207
			rc = current_has_perm(current, PROCESS__EXECSTACK);
3208 3209 3210 3211 3212 3213 3214 3215
		} else if (vma->vm_file && vma->anon_vma) {
			/*
			 * We are making executable a file mapping that has
			 * had some COW done. Since pages might have been
			 * written, check ability to execute the possibly
			 * modified content.  This typically should only
			 * occur for text relocations.
			 */
D
David Howells 已提交
3216
			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3217
		}
3218 3219 3220
		if (rc)
			return rc;
	}
L
Linus Torvalds 已提交
3221 3222 3223 3224 3225 3226

	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
}

static int selinux_file_lock(struct file *file, unsigned int cmd)
{
3227 3228 3229
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, FILE__LOCK);
L
Linus Torvalds 已提交
3230 3231 3232 3233 3234
}

static int selinux_file_fcntl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3235
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3236 3237 3238
	int err = 0;

	switch (cmd) {
3239 3240
	case F_SETFL:
		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3241
			err = file_has_perm(cred, file, FILE__WRITE);
L
Linus Torvalds 已提交
3242
			break;
3243 3244 3245 3246 3247 3248 3249
		}
		/* fall through */
	case F_SETOWN:
	case F_SETSIG:
	case F_GETFL:
	case F_GETOWN:
	case F_GETSIG:
3250
	case F_GETOWNER_UIDS:
3251
		/* Just check FD__USE permission */
3252
		err = file_has_perm(cred, file, 0);
3253 3254 3255 3256
		break;
	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
L
Linus Torvalds 已提交
3257
#if BITS_PER_LONG == 32
3258 3259 3260
	case F_GETLK64:
	case F_SETLK64:
	case F_SETLKW64:
L
Linus Torvalds 已提交
3261
#endif
3262
		err = file_has_perm(cred, file, FILE__LOCK);
3263
		break;
L
Linus Torvalds 已提交
3264 3265 3266 3267 3268 3269 3270 3271 3272 3273
	}

	return err;
}

static int selinux_file_set_fowner(struct file *file)
{
	struct file_security_struct *fsec;

	fsec = file->f_security;
3274
	fsec->fown_sid = current_sid();
L
Linus Torvalds 已提交
3275 3276 3277 3278 3279 3280 3281

	return 0;
}

static int selinux_file_send_sigiotask(struct task_struct *tsk,
				       struct fown_struct *fown, int signum)
{
3282
	struct file *file;
3283
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
3284 3285 3286 3287
	u32 perm;
	struct file_security_struct *fsec;

	/* struct fown_struct is never outside the context of a struct file */
3288
	file = container_of(fown, struct file, f_owner);
L
Linus Torvalds 已提交
3289 3290 3291 3292 3293 3294 3295 3296

	fsec = file->f_security;

	if (!signum)
		perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
	else
		perm = signal_to_av(signum);

3297
	return avc_has_perm(fsec->fown_sid, sid,
L
Linus Torvalds 已提交
3298 3299 3300 3301 3302
			    SECCLASS_PROCESS, perm, NULL);
}

static int selinux_file_receive(struct file *file)
{
3303 3304 3305
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, file_to_av(file));
L
Linus Torvalds 已提交
3306 3307
}

3308
static int selinux_file_open(struct file *file, const struct cred *cred)
3309 3310 3311
{
	struct file_security_struct *fsec;
	struct inode_security_struct *isec;
D
David Howells 已提交
3312

3313
	fsec = file->f_security;
A
Al Viro 已提交
3314
	isec = file_inode(file)->i_security;
3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331
	/*
	 * Save inode label and policy sequence number
	 * at open-time so that selinux_file_permission
	 * can determine whether revalidation is necessary.
	 * Task label is already saved in the file security
	 * struct as its SID.
	 */
	fsec->isid = isec->sid;
	fsec->pseqno = avc_policy_seqno();
	/*
	 * Since the inode label or policy seqno may have changed
	 * between the selinux_inode_permission check and the saving
	 * of state above, recheck that access is still permitted.
	 * Otherwise, access might never be revalidated against the
	 * new inode label or new policy.
	 * This check is not redundant - do not remove.
	 */
3332
	return file_path_has_perm(cred, file, open_file_to_av(file));
3333 3334
}

L
Linus Torvalds 已提交
3335 3336 3337 3338
/* task security operations */

static int selinux_task_create(unsigned long clone_flags)
{
3339
	return current_has_perm(current, PROCESS__FORK);
L
Linus Torvalds 已提交
3340 3341
}

3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356
/*
 * allocate the SELinux part of blank credentials
 */
static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
	struct task_security_struct *tsec;

	tsec = kzalloc(sizeof(struct task_security_struct), gfp);
	if (!tsec)
		return -ENOMEM;

	cred->security = tsec;
	return 0;
}

D
David Howells 已提交
3357 3358 3359 3360
/*
 * detach and free the LSM part of a set of credentials
 */
static void selinux_cred_free(struct cred *cred)
L
Linus Torvalds 已提交
3361
{
D
David Howells 已提交
3362
	struct task_security_struct *tsec = cred->security;
3363

3364 3365 3366 3367 3368
	/*
	 * cred->security == NULL if security_cred_alloc_blank() or
	 * security_prepare_creds() returned an error.
	 */
	BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3369
	cred->security = (void *) 0x7UL;
D
David Howells 已提交
3370 3371
	kfree(tsec);
}
L
Linus Torvalds 已提交
3372

D
David Howells 已提交
3373 3374 3375 3376 3377 3378 3379 3380
/*
 * prepare a new set of credentials for modification
 */
static int selinux_cred_prepare(struct cred *new, const struct cred *old,
				gfp_t gfp)
{
	const struct task_security_struct *old_tsec;
	struct task_security_struct *tsec;
L
Linus Torvalds 已提交
3381

D
David Howells 已提交
3382
	old_tsec = old->security;
L
Linus Torvalds 已提交
3383

D
David Howells 已提交
3384 3385 3386
	tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
	if (!tsec)
		return -ENOMEM;
L
Linus Torvalds 已提交
3387

D
David Howells 已提交
3388
	new->security = tsec;
L
Linus Torvalds 已提交
3389 3390 3391
	return 0;
}

3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402
/*
 * transfer the SELinux data to a blank set of creds
 */
static void selinux_cred_transfer(struct cred *new, const struct cred *old)
{
	const struct task_security_struct *old_tsec = old->security;
	struct task_security_struct *tsec = new->security;

	*tsec = *old_tsec;
}

3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443
/*
 * set the security data for a kernel service
 * - all the creation contexts are set to unlabelled
 */
static int selinux_kernel_act_as(struct cred *new, u32 secid)
{
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

	ret = avc_has_perm(sid, secid,
			   SECCLASS_KERNEL_SERVICE,
			   KERNEL_SERVICE__USE_AS_OVERRIDE,
			   NULL);
	if (ret == 0) {
		tsec->sid = secid;
		tsec->create_sid = 0;
		tsec->keycreate_sid = 0;
		tsec->sockcreate_sid = 0;
	}
	return ret;
}

/*
 * set the file creation context in a security record to the same as the
 * objective context of the specified inode
 */
static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

	ret = avc_has_perm(sid, isec->sid,
			   SECCLASS_KERNEL_SERVICE,
			   KERNEL_SERVICE__CREATE_FILES_AS,
			   NULL);

	if (ret == 0)
		tsec->create_sid = isec->sid;
3444
	return ret;
3445 3446
}

3447
static int selinux_kernel_module_request(char *kmod_name)
3448
{
3449 3450 3451 3452 3453
	u32 sid;
	struct common_audit_data ad;

	sid = task_sid(current);

3454
	ad.type = LSM_AUDIT_DATA_KMOD;
3455 3456 3457 3458
	ad.u.kmod_name = kmod_name;

	return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
			    SYSTEM__MODULE_REQUEST, &ad);
3459 3460
}

L
Linus Torvalds 已提交
3461 3462
static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
{
3463
	return current_has_perm(p, PROCESS__SETPGID);
L
Linus Torvalds 已提交
3464 3465 3466 3467
}

static int selinux_task_getpgid(struct task_struct *p)
{
3468
	return current_has_perm(p, PROCESS__GETPGID);
L
Linus Torvalds 已提交
3469 3470 3471 3472
}

static int selinux_task_getsid(struct task_struct *p)
{
3473
	return current_has_perm(p, PROCESS__GETSESSION);
L
Linus Torvalds 已提交
3474 3475
}

3476 3477
static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
{
3478
	*secid = task_sid(p);
3479 3480
}

L
Linus Torvalds 已提交
3481 3482 3483 3484
static int selinux_task_setnice(struct task_struct *p, int nice)
{
	int rc;

3485
	rc = cap_task_setnice(p, nice);
L
Linus Torvalds 已提交
3486 3487 3488
	if (rc)
		return rc;

3489
	return current_has_perm(p, PROCESS__SETSCHED);
L
Linus Torvalds 已提交
3490 3491
}

3492 3493
static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
3494 3495
	int rc;

3496
	rc = cap_task_setioprio(p, ioprio);
3497 3498 3499
	if (rc)
		return rc;

3500
	return current_has_perm(p, PROCESS__SETSCHED);
3501 3502
}

3503 3504
static int selinux_task_getioprio(struct task_struct *p)
{
3505
	return current_has_perm(p, PROCESS__GETSCHED);
3506 3507
}

3508 3509
static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
		struct rlimit *new_rlim)
L
Linus Torvalds 已提交
3510
{
3511
	struct rlimit *old_rlim = p->signal->rlim + resource;
L
Linus Torvalds 已提交
3512 3513 3514 3515

	/* Control the ability to change the hard limit (whether
	   lowering or raising it), so that the hard limit can
	   later be used as a safe reset point for the soft limit
D
David Howells 已提交
3516
	   upon context transitions.  See selinux_bprm_committing_creds. */
L
Linus Torvalds 已提交
3517
	if (old_rlim->rlim_max != new_rlim->rlim_max)
3518
		return current_has_perm(p, PROCESS__SETRLIMIT);
L
Linus Torvalds 已提交
3519 3520 3521 3522

	return 0;
}

3523
static int selinux_task_setscheduler(struct task_struct *p)
L
Linus Torvalds 已提交
3524
{
3525 3526
	int rc;

3527
	rc = cap_task_setscheduler(p);
3528 3529 3530
	if (rc)
		return rc;

3531
	return current_has_perm(p, PROCESS__SETSCHED);
L
Linus Torvalds 已提交
3532 3533 3534 3535
}

static int selinux_task_getscheduler(struct task_struct *p)
{
3536
	return current_has_perm(p, PROCESS__GETSCHED);
L
Linus Torvalds 已提交
3537 3538
}

3539 3540
static int selinux_task_movememory(struct task_struct *p)
{
3541
	return current_has_perm(p, PROCESS__SETSCHED);
3542 3543
}

3544 3545
static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
				int sig, u32 secid)
L
Linus Torvalds 已提交
3546 3547 3548 3549 3550 3551 3552 3553
{
	u32 perm;
	int rc;

	if (!sig)
		perm = PROCESS__SIGNULL; /* null signal; existence test */
	else
		perm = signal_to_av(sig);
3554
	if (secid)
3555 3556
		rc = avc_has_perm(secid, task_sid(p),
				  SECCLASS_PROCESS, perm, NULL);
3557
	else
3558
		rc = current_has_perm(p, perm);
3559
	return rc;
L
Linus Torvalds 已提交
3560 3561 3562 3563
}

static int selinux_task_wait(struct task_struct *p)
{
3564
	return task_has_perm(p, current, PROCESS__SIGCHLD);
L
Linus Torvalds 已提交
3565 3566 3567 3568 3569 3570
}

static void selinux_task_to_inode(struct task_struct *p,
				  struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
3571
	u32 sid = task_sid(p);
L
Linus Torvalds 已提交
3572

3573
	isec->sid = sid;
L
Linus Torvalds 已提交
3574 3575 3576 3577
	isec->initialized = 1;
}

/* Returns error only if unable to parse addresses */
3578
static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3579
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
3580 3581 3582 3583
{
	int offset, ihlen, ret = -EINVAL;
	struct iphdr _iph, *ih;

3584
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
3585 3586 3587 3588 3589 3590 3591 3592
	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
	if (ih == NULL)
		goto out;

	ihlen = ih->ihl * 4;
	if (ihlen < sizeof(_iph))
		goto out;

3593 3594
	ad->u.net->v4info.saddr = ih->saddr;
	ad->u.net->v4info.daddr = ih->daddr;
L
Linus Torvalds 已提交
3595 3596
	ret = 0;

3597 3598 3599
	if (proto)
		*proto = ih->protocol;

L
Linus Torvalds 已提交
3600
	switch (ih->protocol) {
3601 3602
	case IPPROTO_TCP: {
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
3603

3604 3605
		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;
L
Linus Torvalds 已提交
3606 3607 3608 3609 3610 3611

		offset += ihlen;
		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
		if (th == NULL)
			break;

3612 3613
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
3614
		break;
3615 3616 3617 3618 3619 3620 3621 3622
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

L
Linus Torvalds 已提交
3623
		offset += ihlen;
3624
		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
L
Linus Torvalds 已提交
3625
		if (uh == NULL)
3626
			break;
L
Linus Torvalds 已提交
3627

3628 3629
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
3630 3631
		break;
	}
L
Linus Torvalds 已提交
3632

J
James Morris 已提交
3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

		offset += ihlen;
		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
		if (dh == NULL)
			break;

3644 3645
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
3646
		break;
3647
	}
J
James Morris 已提交
3648

3649 3650 3651
	default:
		break;
	}
L
Linus Torvalds 已提交
3652 3653 3654 3655 3656 3657 3658
out:
	return ret;
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

/* Returns error only if unable to parse addresses */
3659
static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3660
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
3661 3662 3663 3664
{
	u8 nexthdr;
	int ret = -EINVAL, offset;
	struct ipv6hdr _ipv6h, *ip6;
3665
	__be16 frag_off;
L
Linus Torvalds 已提交
3666

3667
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
3668 3669 3670 3671
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		goto out;

3672 3673
	ad->u.net->v6info.saddr = ip6->saddr;
	ad->u.net->v6info.daddr = ip6->daddr;
L
Linus Torvalds 已提交
3674 3675 3676 3677
	ret = 0;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
3678
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
L
Linus Torvalds 已提交
3679 3680 3681
	if (offset < 0)
		goto out;

3682 3683 3684
	if (proto)
		*proto = nexthdr;

L
Linus Torvalds 已提交
3685 3686
	switch (nexthdr) {
	case IPPROTO_TCP: {
3687
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
3688 3689 3690 3691 3692

		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
		if (th == NULL)
			break;

3693 3694
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
3695 3696 3697 3698 3699 3700 3701 3702 3703 3704
		break;
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
		if (uh == NULL)
			break;

3705 3706
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
L
Linus Torvalds 已提交
3707 3708 3709
		break;
	}

J
James Morris 已提交
3710 3711 3712 3713 3714 3715 3716
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
		if (dh == NULL)
			break;

3717 3718
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
3719
		break;
3720
	}
J
James Morris 已提交
3721

L
Linus Torvalds 已提交
3722 3723 3724 3725 3726 3727 3728 3729 3730 3731
	/* includes fragments */
	default:
		break;
	}
out:
	return ret;
}

#endif /* IPV6 */

3732
static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3733
			     char **_addrp, int src, u8 *proto)
L
Linus Torvalds 已提交
3734
{
3735 3736
	char *addrp;
	int ret;
L
Linus Torvalds 已提交
3737

3738
	switch (ad->u.net->family) {
L
Linus Torvalds 已提交
3739
	case PF_INET:
3740
		ret = selinux_parse_skb_ipv4(skb, ad, proto);
3741 3742
		if (ret)
			goto parse_error;
3743 3744
		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
				       &ad->u.net->v4info.daddr);
3745
		goto okay;
L
Linus Torvalds 已提交
3746 3747 3748

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	case PF_INET6:
3749
		ret = selinux_parse_skb_ipv6(skb, ad, proto);
3750 3751
		if (ret)
			goto parse_error;
3752 3753
		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
				       &ad->u.net->v6info.daddr);
3754
		goto okay;
L
Linus Torvalds 已提交
3755 3756
#endif	/* IPV6 */
	default:
3757 3758
		addrp = NULL;
		goto okay;
L
Linus Torvalds 已提交
3759 3760
	}

3761 3762 3763 3764
parse_error:
	printk(KERN_WARNING
	       "SELinux: failure in selinux_parse_skb(),"
	       " unable to parse packet\n");
L
Linus Torvalds 已提交
3765
	return ret;
3766 3767 3768 3769 3770

okay:
	if (_addrp)
		*_addrp = addrp;
	return 0;
L
Linus Torvalds 已提交
3771 3772
}

3773
/**
3774
 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3775
 * @skb: the packet
3776
 * @family: protocol family
3777
 * @sid: the packet's peer label SID
3778 3779
 *
 * Description:
3780 3781 3782 3783 3784 3785
 * Check the various different forms of network peer labeling and determine
 * the peer label/SID for the packet; most of the magic actually occurs in
 * the security server function security_net_peersid_cmp().  The function
 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
 * or -EACCES if @sid is invalid due to inconsistencies with the different
 * peer labels.
3786 3787
 *
 */
3788
static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3789
{
3790
	int err;
3791 3792
	u32 xfrm_sid;
	u32 nlbl_sid;
3793
	u32 nlbl_type;
3794 3795

	selinux_skb_xfrm_sid(skb, &xfrm_sid);
3796
	selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3797

3798 3799 3800 3801 3802
	err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
	if (unlikely(err)) {
		printk(KERN_WARNING
		       "SELinux: failure in selinux_skb_peerlbl_sid(),"
		       " unable to determine packet's peer label\n");
3803
		return -EACCES;
3804
	}
3805 3806

	return 0;
3807 3808
}

L
Linus Torvalds 已提交
3809
/* socket security operations */
3810

3811 3812
static int socket_sockcreate_sid(const struct task_security_struct *tsec,
				 u16 secclass, u32 *socksid)
3813
{
3814 3815 3816 3817 3818 3819 3820
	if (tsec->sockcreate_sid > SECSID_NULL) {
		*socksid = tsec->sockcreate_sid;
		return 0;
	}

	return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
				       socksid);
3821 3822
}

3823
static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
L
Linus Torvalds 已提交
3824
{
3825
	struct sk_security_struct *sksec = sk->sk_security;
3826
	struct common_audit_data ad;
3827
	struct lsm_network_audit net = {0,};
3828
	u32 tsid = task_sid(task);
L
Linus Torvalds 已提交
3829

3830 3831
	if (sksec->sid == SECINITSID_KERNEL)
		return 0;
L
Linus Torvalds 已提交
3832

3833
	ad.type = LSM_AUDIT_DATA_NET;
3834 3835
	ad.u.net = &net;
	ad.u.net->sk = sk;
L
Linus Torvalds 已提交
3836

3837
	return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
L
Linus Torvalds 已提交
3838 3839 3840 3841 3842
}

static int selinux_socket_create(int family, int type,
				 int protocol, int kern)
{
3843
	const struct task_security_struct *tsec = current_security();
3844
	u32 newsid;
3845
	u16 secclass;
3846
	int rc;
L
Linus Torvalds 已提交
3847 3848

	if (kern)
3849
		return 0;
3850 3851

	secclass = socket_type_to_security_class(family, type, protocol);
3852 3853 3854 3855
	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
	if (rc)
		return rc;

3856
	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
L
Linus Torvalds 已提交
3857 3858
}

V
Venkat Yekkirala 已提交
3859 3860
static int selinux_socket_post_create(struct socket *sock, int family,
				      int type, int protocol, int kern)
L
Linus Torvalds 已提交
3861
{
3862
	const struct task_security_struct *tsec = current_security();
3863
	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3864
	struct sk_security_struct *sksec;
3865 3866
	int err = 0;

3867 3868
	isec->sclass = socket_type_to_security_class(family, type, protocol);

3869 3870
	if (kern)
		isec->sid = SECINITSID_KERNEL;
3871 3872 3873 3874 3875
	else {
		err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
		if (err)
			return err;
	}
3876

L
Linus Torvalds 已提交
3877 3878
	isec->initialized = 1;

3879 3880 3881
	if (sock->sk) {
		sksec = sock->sk->sk_security;
		sksec->sid = isec->sid;
3882
		sksec->sclass = isec->sclass;
3883
		err = selinux_netlbl_socket_post_create(sock->sk, family);
3884 3885
	}

V
Venkat Yekkirala 已提交
3886
	return err;
L
Linus Torvalds 已提交
3887 3888 3889 3890 3891 3892 3893 3894
}

/* Range of port numbers used to automatically bind.
   Need to determine whether we should perform a name_bind
   permission check between the socket and the port number. */

static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
{
3895
	struct sock *sk = sock->sk;
L
Linus Torvalds 已提交
3896 3897 3898
	u16 family;
	int err;

3899
	err = sock_has_perm(current, sk, SOCKET__BIND);
L
Linus Torvalds 已提交
3900 3901 3902 3903 3904
	if (err)
		goto out;

	/*
	 * If PF_INET or PF_INET6, check name_bind permission for the port.
3905 3906
	 * Multiple address binding for SCTP is not supported yet: we just
	 * check the first address now.
L
Linus Torvalds 已提交
3907
	 */
3908
	family = sk->sk_family;
L
Linus Torvalds 已提交
3909 3910
	if (family == PF_INET || family == PF_INET6) {
		char *addrp;
3911
		struct sk_security_struct *sksec = sk->sk_security;
3912
		struct common_audit_data ad;
3913
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
3914 3915 3916
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
3917
		u32 sid, node_perm;
L
Linus Torvalds 已提交
3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928

		if (family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
			snum = ntohs(addr4->sin_port);
			addrp = (char *)&addr4->sin_addr.s_addr;
		} else {
			addr6 = (struct sockaddr_in6 *)address;
			snum = ntohs(addr6->sin6_port);
			addrp = (char *)&addr6->sin6_addr.s6_addr;
		}

3929 3930 3931
		if (snum) {
			int low, high;

3932
			inet_get_local_port_range(sock_net(sk), &low, &high);
3933 3934

			if (snum < max(PROT_SOCK, low) || snum > high) {
P
Paul Moore 已提交
3935 3936
				err = sel_netport_sid(sk->sk_protocol,
						      snum, &sid);
3937 3938
				if (err)
					goto out;
3939
				ad.type = LSM_AUDIT_DATA_NET;
3940 3941 3942
				ad.u.net = &net;
				ad.u.net->sport = htons(snum);
				ad.u.net->family = family;
3943 3944
				err = avc_has_perm(sksec->sid, sid,
						   sksec->sclass,
3945 3946 3947 3948
						   SOCKET__NAME_BIND, &ad);
				if (err)
					goto out;
			}
L
Linus Torvalds 已提交
3949
		}
3950

3951
		switch (sksec->sclass) {
3952
		case SECCLASS_TCP_SOCKET:
L
Linus Torvalds 已提交
3953 3954
			node_perm = TCP_SOCKET__NODE_BIND;
			break;
3955

3956
		case SECCLASS_UDP_SOCKET:
L
Linus Torvalds 已提交
3957 3958
			node_perm = UDP_SOCKET__NODE_BIND;
			break;
J
James Morris 已提交
3959 3960 3961 3962 3963

		case SECCLASS_DCCP_SOCKET:
			node_perm = DCCP_SOCKET__NODE_BIND;
			break;

L
Linus Torvalds 已提交
3964 3965 3966 3967
		default:
			node_perm = RAWIP_SOCKET__NODE_BIND;
			break;
		}
3968

3969
		err = sel_netnode_sid(addrp, family, &sid);
L
Linus Torvalds 已提交
3970 3971
		if (err)
			goto out;
3972

3973
		ad.type = LSM_AUDIT_DATA_NET;
3974 3975 3976
		ad.u.net = &net;
		ad.u.net->sport = htons(snum);
		ad.u.net->family = family;
L
Linus Torvalds 已提交
3977 3978

		if (family == PF_INET)
3979
			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
L
Linus Torvalds 已提交
3980
		else
3981
			ad.u.net->v6info.saddr = addr6->sin6_addr;
L
Linus Torvalds 已提交
3982

3983 3984
		err = avc_has_perm(sksec->sid, sid,
				   sksec->sclass, node_perm, &ad);
L
Linus Torvalds 已提交
3985 3986 3987 3988 3989 3990 3991 3992 3993
		if (err)
			goto out;
	}
out:
	return err;
}

static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
{
3994
	struct sock *sk = sock->sk;
3995
	struct sk_security_struct *sksec = sk->sk_security;
L
Linus Torvalds 已提交
3996 3997
	int err;

3998
	err = sock_has_perm(current, sk, SOCKET__CONNECT);
L
Linus Torvalds 已提交
3999 4000 4001 4002
	if (err)
		return err;

	/*
J
James Morris 已提交
4003
	 * If a TCP or DCCP socket, check name_connect permission for the port.
L
Linus Torvalds 已提交
4004
	 */
4005 4006
	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
4007
		struct common_audit_data ad;
4008
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4009 4010 4011
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
J
James Morris 已提交
4012
		u32 sid, perm;
L
Linus Torvalds 已提交
4013 4014 4015

		if (sk->sk_family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
4016
			if (addrlen < sizeof(struct sockaddr_in))
L
Linus Torvalds 已提交
4017 4018 4019 4020
				return -EINVAL;
			snum = ntohs(addr4->sin_port);
		} else {
			addr6 = (struct sockaddr_in6 *)address;
4021
			if (addrlen < SIN6_LEN_RFC2133)
L
Linus Torvalds 已提交
4022 4023 4024 4025
				return -EINVAL;
			snum = ntohs(addr6->sin6_port);
		}

P
Paul Moore 已提交
4026
		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
L
Linus Torvalds 已提交
4027 4028 4029
		if (err)
			goto out;

4030
		perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
J
James Morris 已提交
4031 4032
		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;

4033
		ad.type = LSM_AUDIT_DATA_NET;
4034 4035 4036
		ad.u.net = &net;
		ad.u.net->dport = htons(snum);
		ad.u.net->family = sk->sk_family;
4037
		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
L
Linus Torvalds 已提交
4038 4039 4040 4041
		if (err)
			goto out;
	}

4042 4043
	err = selinux_netlbl_socket_connect(sk, address);

L
Linus Torvalds 已提交
4044 4045 4046 4047 4048 4049
out:
	return err;
}

static int selinux_socket_listen(struct socket *sock, int backlog)
{
4050
	return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
L
Linus Torvalds 已提交
4051 4052 4053 4054 4055 4056 4057 4058
}

static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
{
	int err;
	struct inode_security_struct *isec;
	struct inode_security_struct *newisec;

4059
	err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
L
Linus Torvalds 已提交
4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073
	if (err)
		return err;

	newisec = SOCK_INODE(newsock)->i_security;

	isec = SOCK_INODE(sock)->i_security;
	newisec->sclass = isec->sclass;
	newisec->sid = isec->sid;
	newisec->initialized = 1;

	return 0;
}

static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4074
				  int size)
L
Linus Torvalds 已提交
4075
{
4076
	return sock_has_perm(current, sock->sk, SOCKET__WRITE);
L
Linus Torvalds 已提交
4077 4078 4079 4080 4081
}

static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
				  int size, int flags)
{
4082
	return sock_has_perm(current, sock->sk, SOCKET__READ);
L
Linus Torvalds 已提交
4083 4084 4085 4086
}

static int selinux_socket_getsockname(struct socket *sock)
{
4087
	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4088 4089 4090 4091
}

static int selinux_socket_getpeername(struct socket *sock)
{
4092
	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4093 4094
}

4095
static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
L
Linus Torvalds 已提交
4096
{
4097 4098
	int err;

4099
	err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4100 4101 4102 4103
	if (err)
		return err;

	return selinux_netlbl_socket_setsockopt(sock, level, optname);
L
Linus Torvalds 已提交
4104 4105 4106 4107 4108
}

static int selinux_socket_getsockopt(struct socket *sock, int level,
				     int optname)
{
4109
	return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
L
Linus Torvalds 已提交
4110 4111 4112 4113
}

static int selinux_socket_shutdown(struct socket *sock, int how)
{
4114
	return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
L
Linus Torvalds 已提交
4115 4116
}

4117 4118
static int selinux_socket_unix_stream_connect(struct sock *sock,
					      struct sock *other,
L
Linus Torvalds 已提交
4119 4120
					      struct sock *newsk)
{
4121 4122
	struct sk_security_struct *sksec_sock = sock->sk_security;
	struct sk_security_struct *sksec_other = other->sk_security;
4123
	struct sk_security_struct *sksec_new = newsk->sk_security;
4124
	struct common_audit_data ad;
4125
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4126 4127
	int err;

4128
	ad.type = LSM_AUDIT_DATA_NET;
4129 4130
	ad.u.net = &net;
	ad.u.net->sk = other;
L
Linus Torvalds 已提交
4131

4132 4133
	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
			   sksec_other->sclass,
L
Linus Torvalds 已提交
4134 4135 4136 4137 4138
			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
	if (err)
		return err;

	/* server child socket */
4139 4140 4141 4142 4143
	sksec_new->peer_sid = sksec_sock->sid;
	err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
				    &sksec_new->sid);
	if (err)
		return err;
4144

4145 4146 4147 4148
	/* connecting socket */
	sksec_sock->peer_sid = sksec_new->sid;

	return 0;
L
Linus Torvalds 已提交
4149 4150 4151 4152 4153
}

static int selinux_socket_unix_may_send(struct socket *sock,
					struct socket *other)
{
4154 4155
	struct sk_security_struct *ssec = sock->sk->sk_security;
	struct sk_security_struct *osec = other->sk->sk_security;
4156
	struct common_audit_data ad;
4157
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4158

4159
	ad.type = LSM_AUDIT_DATA_NET;
4160 4161
	ad.u.net = &net;
	ad.u.net->sk = other->sk;
L
Linus Torvalds 已提交
4162

4163 4164
	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
			    &ad);
L
Linus Torvalds 已提交
4165 4166
}

4167 4168
static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
				    u32 peer_sid,
4169
				    struct common_audit_data *ad)
4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189
{
	int err;
	u32 if_sid;
	u32 node_sid;

	err = sel_netif_sid(ifindex, &if_sid);
	if (err)
		return err;
	err = avc_has_perm(peer_sid, if_sid,
			   SECCLASS_NETIF, NETIF__INGRESS, ad);
	if (err)
		return err;

	err = sel_netnode_sid(addrp, family, &node_sid);
	if (err)
		return err;
	return avc_has_perm(peer_sid, node_sid,
			    SECCLASS_NODE, NODE__RECVFROM, ad);
}

4190
static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4191
				       u16 family)
4192
{
4193
	int err = 0;
4194 4195
	struct sk_security_struct *sksec = sk->sk_security;
	u32 sk_sid = sksec->sid;
4196
	struct common_audit_data ad;
4197
	struct lsm_network_audit net = {0,};
4198 4199
	char *addrp;

4200
	ad.type = LSM_AUDIT_DATA_NET;
4201 4202 4203
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4204 4205 4206
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
	if (err)
		return err;
L
Linus Torvalds 已提交
4207

4208
	if (selinux_secmark_enabled()) {
4209
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4210
				   PACKET__RECV, &ad);
4211 4212 4213
		if (err)
			return err;
	}
4214

4215 4216 4217 4218
	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
	if (err)
		return err;
	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4219

4220 4221 4222 4223 4224
	return err;
}

static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
4225
	int err;
4226
	struct sk_security_struct *sksec = sk->sk_security;
4227 4228
	u16 family = sk->sk_family;
	u32 sk_sid = sksec->sid;
4229
	struct common_audit_data ad;
4230
	struct lsm_network_audit net = {0,};
4231
	char *addrp;
4232 4233
	u8 secmark_active;
	u8 peerlbl_active;
4234 4235

	if (family != PF_INET && family != PF_INET6)
4236
		return 0;
4237 4238

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
A
Al Viro 已提交
4239
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4240 4241
		family = PF_INET;

4242 4243 4244 4245
	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_sock_rcv_skb_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
4246
	if (!selinux_policycap_netpeer)
4247 4248 4249 4250 4251 4252 4253
		return selinux_sock_rcv_skb_compat(sk, skb, family);

	secmark_active = selinux_secmark_enabled();
	peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
	if (!secmark_active && !peerlbl_active)
		return 0;

4254
	ad.type = LSM_AUDIT_DATA_NET;
4255 4256 4257
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4258
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4259
	if (err)
4260
		return err;
4261

4262
	if (peerlbl_active) {
4263 4264 4265
		u32 peer_sid;

		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4266 4267
		if (err)
			return err;
4268
		err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4269
					       peer_sid, &ad);
4270 4271
		if (err) {
			selinux_netlbl_err(skb, err, 0);
4272
			return err;
4273
		}
4274 4275
		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
				   PEER__RECV, &ad);
4276 4277
		if (err)
			selinux_netlbl_err(skb, err, 0);
4278 4279
	}

4280
	if (secmark_active) {
4281 4282 4283 4284 4285 4286
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
				   PACKET__RECV, &ad);
		if (err)
			return err;
	}

4287
	return err;
L
Linus Torvalds 已提交
4288 4289
}

C
Catherine Zhang 已提交
4290 4291
static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
					    int __user *optlen, unsigned len)
L
Linus Torvalds 已提交
4292 4293 4294 4295
{
	int err = 0;
	char *scontext;
	u32 scontext_len;
4296
	struct sk_security_struct *sksec = sock->sk->sk_security;
4297
	u32 peer_sid = SECSID_NULL;
L
Linus Torvalds 已提交
4298

4299 4300
	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
	    sksec->sclass == SECCLASS_TCP_SOCKET)
4301
		peer_sid = sksec->peer_sid;
4302 4303
	if (peer_sid == SECSID_NULL)
		return -ENOPROTOOPT;
L
Linus Torvalds 已提交
4304

C
Catherine Zhang 已提交
4305
	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
L
Linus Torvalds 已提交
4306
	if (err)
4307
		return err;
L
Linus Torvalds 已提交
4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323

	if (scontext_len > len) {
		err = -ERANGE;
		goto out_len;
	}

	if (copy_to_user(optval, scontext, scontext_len))
		err = -EFAULT;

out_len:
	if (put_user(scontext_len, optlen))
		err = -EFAULT;
	kfree(scontext);
	return err;
}

4324
static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
C
Catherine Zhang 已提交
4325
{
4326
	u32 peer_secid = SECSID_NULL;
4327
	u16 family;
C
Catherine Zhang 已提交
4328

4329 4330 4331 4332 4333
	if (skb && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;
	else if (skb && skb->protocol == htons(ETH_P_IPV6))
		family = PF_INET6;
	else if (sock)
4334 4335 4336 4337 4338
		family = sock->sk->sk_family;
	else
		goto out;

	if (sock && family == PF_UNIX)
4339
		selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4340
	else if (skb)
4341
		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
C
Catherine Zhang 已提交
4342

4343
out:
4344
	*secid = peer_secid;
4345 4346 4347
	if (peer_secid == SECSID_NULL)
		return -EINVAL;
	return 0;
C
Catherine Zhang 已提交
4348 4349
}

A
Al Viro 已提交
4350
static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
L
Linus Torvalds 已提交
4351
{
4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363
	struct sk_security_struct *sksec;

	sksec = kzalloc(sizeof(*sksec), priority);
	if (!sksec)
		return -ENOMEM;

	sksec->peer_sid = SECINITSID_UNLABELED;
	sksec->sid = SECINITSID_UNLABELED;
	selinux_netlbl_sk_security_reset(sksec);
	sk->sk_security = sksec;

	return 0;
L
Linus Torvalds 已提交
4364 4365 4366 4367
}

static void selinux_sk_free_security(struct sock *sk)
{
4368 4369 4370 4371 4372
	struct sk_security_struct *sksec = sk->sk_security;

	sk->sk_security = NULL;
	selinux_netlbl_sk_security_free(sksec);
	kfree(sksec);
L
Linus Torvalds 已提交
4373 4374
}

4375
static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4376
{
4377 4378
	struct sk_security_struct *sksec = sk->sk_security;
	struct sk_security_struct *newsksec = newsk->sk_security;
4379

4380 4381 4382
	newsksec->sid = sksec->sid;
	newsksec->peer_sid = sksec->peer_sid;
	newsksec->sclass = sksec->sclass;
4383

4384
	selinux_netlbl_sk_security_reset(newsksec);
4385 4386
}

V
Venkat Yekkirala 已提交
4387
static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4388
{
4389
	if (!sk)
V
Venkat Yekkirala 已提交
4390
		*secid = SECINITSID_ANY_SOCKET;
4391 4392
	else {
		struct sk_security_struct *sksec = sk->sk_security;
4393

V
Venkat Yekkirala 已提交
4394
		*secid = sksec->sid;
4395
	}
4396 4397
}

4398
static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4399 4400 4401 4402
{
	struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
	struct sk_security_struct *sksec = sk->sk_security;

4403 4404 4405
	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
	    sk->sk_family == PF_UNIX)
		isec->sid = sksec->sid;
4406
	sksec->sclass = isec->sclass;
4407 4408
}

4409 4410
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				     struct request_sock *req)
4411 4412 4413
{
	struct sk_security_struct *sksec = sk->sk_security;
	int err;
4414
	u16 family = sk->sk_family;
V
Venkat Yekkirala 已提交
4415
	u32 newsid;
4416 4417
	u32 peersid;

4418 4419 4420 4421 4422
	/* handle mapped IPv4 packets arriving via IPv6 sockets */
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;

	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4423 4424
	if (err)
		return err;
4425 4426
	if (peersid == SECSID_NULL) {
		req->secid = sksec->sid;
4427
		req->peer_secid = SECSID_NULL;
4428 4429 4430 4431 4432 4433
	} else {
		err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
		if (err)
			return err;
		req->secid = newsid;
		req->peer_secid = peersid;
4434 4435
	}

4436
	return selinux_netlbl_inet_conn_request(req, family);
4437 4438
}

4439 4440
static void selinux_inet_csk_clone(struct sock *newsk,
				   const struct request_sock *req)
4441 4442 4443 4444
{
	struct sk_security_struct *newsksec = newsk->sk_security;

	newsksec->sid = req->secid;
4445
	newsksec->peer_sid = req->peer_secid;
4446 4447 4448 4449
	/* NOTE: Ideally, we should also get the isec->sid for the
	   new socket in sync, but we don't have the isec available yet.
	   So we will wait until sock_graft to do it, by which
	   time it will have been created and available. */
4450

P
Paul Moore 已提交
4451 4452
	/* We don't need to take any sort of lock here as we are the only
	 * thread with access to newsksec */
4453
	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4454 4455
}

4456
static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4457
{
4458
	u16 family = sk->sk_family;
4459 4460
	struct sk_security_struct *sksec = sk->sk_security;

4461 4462 4463 4464 4465
	/* handle mapped IPv4 packets arriving via IPv6 sockets */
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;

	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4466 4467
}

4468 4469 4470 4471 4472
static void selinux_skb_owned_by(struct sk_buff *skb, struct sock *sk)
{
	skb_set_owner_w(skb, sk);
}

4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487 4488 4489 4490 4491 4492 4493
static int selinux_secmark_relabel_packet(u32 sid)
{
	const struct task_security_struct *__tsec;
	u32 tsid;

	__tsec = current_security();
	tsid = __tsec->sid;

	return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
}

static void selinux_secmark_refcount_inc(void)
{
	atomic_inc(&selinux_secmark_refcount);
}

static void selinux_secmark_refcount_dec(void)
{
	atomic_dec(&selinux_secmark_refcount);
}

4494 4495
static void selinux_req_classify_flow(const struct request_sock *req,
				      struct flowi *fl)
4496
{
4497
	fl->flowi_secid = req->secid;
4498 4499
}

4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517
static int selinux_tun_dev_alloc_security(void **security)
{
	struct tun_security_struct *tunsec;

	tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
	if (!tunsec)
		return -ENOMEM;
	tunsec->sid = current_sid();

	*security = tunsec;
	return 0;
}

static void selinux_tun_dev_free_security(void *security)
{
	kfree(security);
}

4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532
static int selinux_tun_dev_create(void)
{
	u32 sid = current_sid();

	/* we aren't taking into account the "sockcreate" SID since the socket
	 * that is being created here is not a socket in the traditional sense,
	 * instead it is a private sock, accessible only to the kernel, and
	 * representing a wide range of network traffic spanning multiple
	 * connections unlike traditional sockets - check the TUN driver to
	 * get a better understanding of why this socket is special */

	return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
			    NULL);
}

4533
static int selinux_tun_dev_attach_queue(void *security)
4534
{
4535 4536 4537 4538 4539 4540 4541 4542 4543
	struct tun_security_struct *tunsec = security;

	return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
			    TUN_SOCKET__ATTACH_QUEUE, NULL);
}

static int selinux_tun_dev_attach(struct sock *sk, void *security)
{
	struct tun_security_struct *tunsec = security;
4544 4545 4546 4547 4548 4549 4550 4551 4552
	struct sk_security_struct *sksec = sk->sk_security;

	/* we don't currently perform any NetLabel based labeling here and it
	 * isn't clear that we would want to do so anyway; while we could apply
	 * labeling without the support of the TUN user the resulting labeled
	 * traffic from the other end of the connection would almost certainly
	 * cause confusion to the TUN user that had no idea network labeling
	 * protocols were being used */

4553
	sksec->sid = tunsec->sid;
4554
	sksec->sclass = SECCLASS_TUN_SOCKET;
4555 4556

	return 0;
4557 4558
}

4559
static int selinux_tun_dev_open(void *security)
4560
{
4561
	struct tun_security_struct *tunsec = security;
4562 4563 4564
	u32 sid = current_sid();
	int err;

4565
	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
4566 4567 4568 4569 4570 4571 4572
			   TUN_SOCKET__RELABELFROM, NULL);
	if (err)
		return err;
	err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
			   TUN_SOCKET__RELABELTO, NULL);
	if (err)
		return err;
4573
	tunsec->sid = sid;
4574 4575 4576 4577

	return 0;
}

L
Linus Torvalds 已提交
4578 4579 4580 4581 4582
static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
{
	int err = 0;
	u32 perm;
	struct nlmsghdr *nlh;
4583
	struct sk_security_struct *sksec = sk->sk_security;
4584

4585
	if (skb->len < NLMSG_HDRLEN) {
L
Linus Torvalds 已提交
4586 4587 4588
		err = -EINVAL;
		goto out;
	}
4589
	nlh = nlmsg_hdr(skb);
4590

4591
	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
L
Linus Torvalds 已提交
4592 4593
	if (err) {
		if (err == -EINVAL) {
4594
			audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
L
Linus Torvalds 已提交
4595 4596
				  "SELinux:  unrecognized netlink message"
				  " type=%hu for sclass=%hu\n",
4597
				  nlh->nlmsg_type, sksec->sclass);
4598
			if (!selinux_enforcing || security_get_allow_unknown())
L
Linus Torvalds 已提交
4599 4600 4601 4602 4603 4604 4605 4606 4607
				err = 0;
		}

		/* Ignore */
		if (err == -ENOENT)
			err = 0;
		goto out;
	}

4608
	err = sock_has_perm(current, sk, perm);
L
Linus Torvalds 已提交
4609 4610 4611 4612 4613 4614
out:
	return err;
}

#ifdef CONFIG_NETFILTER

4615 4616
static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
				       u16 family)
L
Linus Torvalds 已提交
4617
{
4618
	int err;
4619 4620
	char *addrp;
	u32 peer_sid;
4621
	struct common_audit_data ad;
4622
	struct lsm_network_audit net = {0,};
4623
	u8 secmark_active;
4624
	u8 netlbl_active;
4625
	u8 peerlbl_active;
4626

4627 4628
	if (!selinux_policycap_netpeer)
		return NF_ACCEPT;
4629

4630
	secmark_active = selinux_secmark_enabled();
4631 4632
	netlbl_active = netlbl_enabled();
	peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4633 4634
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;
4635

4636 4637 4638
	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
		return NF_DROP;

4639
	ad.type = LSM_AUDIT_DATA_NET;
4640 4641 4642
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4643 4644 4645
	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
		return NF_DROP;

4646 4647 4648 4649 4650
	if (peerlbl_active) {
		err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
					       peer_sid, &ad);
		if (err) {
			selinux_netlbl_err(skb, err, 1);
4651
			return NF_DROP;
4652 4653
		}
	}
4654 4655 4656 4657 4658 4659

	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
			return NF_DROP;

4660 4661 4662 4663 4664 4665 4666 4667
	if (netlbl_active)
		/* we do this in the FORWARD path and not the POST_ROUTING
		 * path because we want to make sure we apply the necessary
		 * labeling before IPsec is applied so we can leverage AH
		 * protection */
		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
			return NF_DROP;

4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690
	return NF_ACCEPT;
}

static unsigned int selinux_ipv4_forward(unsigned int hooknum,
					 struct sk_buff *skb,
					 const struct net_device *in,
					 const struct net_device *out,
					 int (*okfn)(struct sk_buff *))
{
	return selinux_ip_forward(skb, in->ifindex, PF_INET);
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static unsigned int selinux_ipv6_forward(unsigned int hooknum,
					 struct sk_buff *skb,
					 const struct net_device *in,
					 const struct net_device *out,
					 int (*okfn)(struct sk_buff *))
{
	return selinux_ip_forward(skb, in->ifindex, PF_INET6);
}
#endif	/* IPV6 */

4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721
static unsigned int selinux_ip_output(struct sk_buff *skb,
				      u16 family)
{
	u32 sid;

	if (!netlbl_enabled())
		return NF_ACCEPT;

	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
	 * because we want to make sure we apply the necessary labeling
	 * before IPsec is applied so we can leverage AH protection */
	if (skb->sk) {
		struct sk_security_struct *sksec = skb->sk->sk_security;
		sid = sksec->sid;
	} else
		sid = SECINITSID_KERNEL;
	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
		return NF_DROP;

	return NF_ACCEPT;
}

static unsigned int selinux_ipv4_output(unsigned int hooknum,
					struct sk_buff *skb,
					const struct net_device *in,
					const struct net_device *out,
					int (*okfn)(struct sk_buff *))
{
	return selinux_ip_output(skb, PF_INET);
}

4722 4723
static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
						int ifindex,
4724
						u16 family)
4725 4726 4727
{
	struct sock *sk = skb->sk;
	struct sk_security_struct *sksec;
4728
	struct common_audit_data ad;
4729
	struct lsm_network_audit net = {0,};
4730 4731
	char *addrp;
	u8 proto;
L
Linus Torvalds 已提交
4732

4733 4734 4735 4736
	if (sk == NULL)
		return NF_ACCEPT;
	sksec = sk->sk_security;

4737
	ad.type = LSM_AUDIT_DATA_NET;
4738 4739 4740
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4741 4742 4743
	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
		return NF_DROP;

4744
	if (selinux_secmark_enabled())
4745
		if (avc_has_perm(sksec->sid, skb->secmark,
4746
				 SECCLASS_PACKET, PACKET__SEND, &ad))
4747
			return NF_DROP_ERR(-ECONNREFUSED);
4748

4749 4750
	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
		return NF_DROP_ERR(-ECONNREFUSED);
4751 4752

	return NF_ACCEPT;
4753 4754
}

4755 4756
static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
					 u16 family)
4757
{
4758 4759
	u32 secmark_perm;
	u32 peer_sid;
4760
	struct sock *sk;
4761
	struct common_audit_data ad;
4762
	struct lsm_network_audit net = {0,};
4763 4764 4765
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;
4766

4767 4768 4769 4770
	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_ip_postroute_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
4771
	if (!selinux_policycap_netpeer)
4772
		return selinux_ip_postroute_compat(skb, ifindex, family);
4773
#ifdef CONFIG_XFRM
4774 4775 4776 4777 4778 4779
	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
	 * packet transformation so allow the packet to pass without any checks
	 * since we'll have another chance to perform access control checks
	 * when the packet is on it's final way out.
	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
	 *       is NULL, in this case go ahead and apply access control. */
E
Eric Dumazet 已提交
4780
	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4781
		return NF_ACCEPT;
4782
#endif
4783 4784 4785 4786 4787
	secmark_active = selinux_secmark_enabled();
	peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;

4788 4789 4790 4791
	/* if the packet is being forwarded then get the peer label from the
	 * packet itself; otherwise check to see if it is from a local
	 * application or the kernel, if from an application get the peer label
	 * from the sending socket, otherwise use the kernel's sid */
4792
	sk = skb->sk;
4793
	if (sk == NULL) {
4794 4795
		if (skb->skb_iif) {
			secmark_perm = PACKET__FORWARD_OUT;
4796
			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4797
				return NF_DROP;
4798 4799
		} else {
			secmark_perm = PACKET__SEND;
4800
			peer_sid = SECINITSID_KERNEL;
4801
		}
4802
	} else {
4803 4804 4805 4806
		struct sk_security_struct *sksec = sk->sk_security;
		peer_sid = sksec->sid;
		secmark_perm = PACKET__SEND;
	}
4807

4808
	ad.type = LSM_AUDIT_DATA_NET;
4809 4810 4811
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4812
	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4813
		return NF_DROP;
4814

4815 4816 4817
	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, secmark_perm, &ad))
4818
			return NF_DROP_ERR(-ECONNREFUSED);
4819 4820 4821 4822 4823 4824

	if (peerlbl_active) {
		u32 if_sid;
		u32 node_sid;

		if (sel_netif_sid(ifindex, &if_sid))
4825
			return NF_DROP;
4826 4827
		if (avc_has_perm(peer_sid, if_sid,
				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4828
			return NF_DROP_ERR(-ECONNREFUSED);
4829 4830

		if (sel_netnode_sid(addrp, family, &node_sid))
4831
			return NF_DROP;
4832 4833
		if (avc_has_perm(peer_sid, node_sid,
				 SECCLASS_NODE, NODE__SENDTO, &ad))
4834
			return NF_DROP_ERR(-ECONNREFUSED);
4835
	}
4836

4837
	return NF_ACCEPT;
L
Linus Torvalds 已提交
4838 4839
}

4840 4841 4842 4843 4844
static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
					   struct sk_buff *skb,
					   const struct net_device *in,
					   const struct net_device *out,
					   int (*okfn)(struct sk_buff *))
L
Linus Torvalds 已提交
4845
{
4846
	return selinux_ip_postroute(skb, out->ifindex, PF_INET);
L
Linus Torvalds 已提交
4847 4848 4849
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4850 4851 4852 4853 4854
static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
					   struct sk_buff *skb,
					   const struct net_device *in,
					   const struct net_device *out,
					   int (*okfn)(struct sk_buff *))
L
Linus Torvalds 已提交
4855
{
4856
	return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
L
Linus Torvalds 已提交
4857 4858 4859 4860 4861 4862 4863 4864 4865
}
#endif	/* IPV6 */

#endif	/* CONFIG_NETFILTER */

static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
{
	int err;

4866
	err = cap_netlink_send(sk, skb);
L
Linus Torvalds 已提交
4867 4868 4869
	if (err)
		return err;

4870
	return selinux_nlmsg_perm(sk, skb);
L
Linus Torvalds 已提交
4871 4872 4873 4874 4875 4876 4877
}

static int ipc_alloc_security(struct task_struct *task,
			      struct kern_ipc_perm *perm,
			      u16 sclass)
{
	struct ipc_security_struct *isec;
4878
	u32 sid;
L
Linus Torvalds 已提交
4879

J
James Morris 已提交
4880
	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
4881 4882 4883
	if (!isec)
		return -ENOMEM;

4884
	sid = task_sid(task);
L
Linus Torvalds 已提交
4885
	isec->sclass = sclass;
4886
	isec->sid = sid;
L
Linus Torvalds 已提交
4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902
	perm->security = isec;

	return 0;
}

static void ipc_free_security(struct kern_ipc_perm *perm)
{
	struct ipc_security_struct *isec = perm->security;
	perm->security = NULL;
	kfree(isec);
}

static int msg_msg_alloc_security(struct msg_msg *msg)
{
	struct msg_security_struct *msec;

J
James Morris 已提交
4903
	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921
	if (!msec)
		return -ENOMEM;

	msec->sid = SECINITSID_UNLABELED;
	msg->security = msec;

	return 0;
}

static void msg_msg_free_security(struct msg_msg *msg)
{
	struct msg_security_struct *msec = msg->security;

	msg->security = NULL;
	kfree(msec);
}

static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4922
			u32 perms)
L
Linus Torvalds 已提交
4923 4924
{
	struct ipc_security_struct *isec;
4925
	struct common_audit_data ad;
4926
	u32 sid = current_sid();
L
Linus Torvalds 已提交
4927 4928 4929

	isec = ipc_perms->security;

4930
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
4931 4932
	ad.u.ipc_id = ipc_perms->key;

4933
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
L
Linus Torvalds 已提交
4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949
}

static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
{
	return msg_msg_alloc_security(msg);
}

static void selinux_msg_msg_free_security(struct msg_msg *msg)
{
	msg_msg_free_security(msg);
}

/* message queue security operations */
static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
{
	struct ipc_security_struct *isec;
4950
	struct common_audit_data ad;
4951
	u32 sid = current_sid();
L
Linus Torvalds 已提交
4952 4953 4954 4955 4956 4957 4958 4959
	int rc;

	rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
	if (rc)
		return rc;

	isec = msq->q_perm.security;

4960
	ad.type = LSM_AUDIT_DATA_IPC;
4961
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
4962

4963
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
4964 4965 4966 4967 4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979
			  MSGQ__CREATE, &ad);
	if (rc) {
		ipc_free_security(&msq->q_perm);
		return rc;
	}
	return 0;
}

static void selinux_msg_queue_free_security(struct msg_queue *msq)
{
	ipc_free_security(&msq->q_perm);
}

static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
{
	struct ipc_security_struct *isec;
4980
	struct common_audit_data ad;
4981
	u32 sid = current_sid();
L
Linus Torvalds 已提交
4982 4983 4984

	isec = msq->q_perm.security;

4985
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
4986 4987
	ad.u.ipc_id = msq->q_perm.key;

4988
	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
4989 4990 4991 4992 4993 4994 4995 4996
			    MSGQ__ASSOCIATE, &ad);
}

static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
{
	int err;
	int perms;

4997
	switch (cmd) {
L
Linus Torvalds 已提交
4998 4999 5000 5001 5002 5003 5004 5005 5006 5007 5008 5009 5010 5011 5012 5013 5014 5015
	case IPC_INFO:
	case MSG_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	case IPC_STAT:
	case MSG_STAT:
		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
		break;
	case IPC_SET:
		perms = MSGQ__SETATTR;
		break;
	case IPC_RMID:
		perms = MSGQ__DESTROY;
		break;
	default:
		return 0;
	}

5016
	err = ipc_has_perm(&msq->q_perm, perms);
L
Linus Torvalds 已提交
5017 5018 5019 5020 5021 5022 5023
	return err;
}

static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
{
	struct ipc_security_struct *isec;
	struct msg_security_struct *msec;
5024
	struct common_audit_data ad;
5025
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038
	int rc;

	isec = msq->q_perm.security;
	msec = msg->security;

	/*
	 * First time through, need to assign label to the message
	 */
	if (msec->sid == SECINITSID_UNLABELED) {
		/*
		 * Compute new sid based on current process and
		 * message queue this message will be stored in
		 */
5039
		rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5040
					     NULL, &msec->sid);
L
Linus Torvalds 已提交
5041 5042 5043 5044
		if (rc)
			return rc;
	}

5045
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5046 5047 5048
	ad.u.ipc_id = msq->q_perm.key;

	/* Can this process write to the queue? */
5049
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5050 5051 5052
			  MSGQ__WRITE, &ad);
	if (!rc)
		/* Can this process send the message */
5053 5054
		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
				  MSG__SEND, &ad);
L
Linus Torvalds 已提交
5055 5056
	if (!rc)
		/* Can the message be put in the queue? */
5057 5058
		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
				  MSGQ__ENQUEUE, &ad);
L
Linus Torvalds 已提交
5059 5060 5061 5062 5063 5064 5065 5066 5067 5068

	return rc;
}

static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
				    struct task_struct *target,
				    long type, int mode)
{
	struct ipc_security_struct *isec;
	struct msg_security_struct *msec;
5069
	struct common_audit_data ad;
5070
	u32 sid = task_sid(target);
L
Linus Torvalds 已提交
5071 5072 5073 5074 5075
	int rc;

	isec = msq->q_perm.security;
	msec = msg->security;

5076
	ad.type = LSM_AUDIT_DATA_IPC;
5077
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5078

5079
	rc = avc_has_perm(sid, isec->sid,
L
Linus Torvalds 已提交
5080 5081
			  SECCLASS_MSGQ, MSGQ__READ, &ad);
	if (!rc)
5082
		rc = avc_has_perm(sid, msec->sid,
L
Linus Torvalds 已提交
5083 5084 5085 5086 5087 5088 5089 5090
				  SECCLASS_MSG, MSG__RECEIVE, &ad);
	return rc;
}

/* Shared Memory security operations */
static int selinux_shm_alloc_security(struct shmid_kernel *shp)
{
	struct ipc_security_struct *isec;
5091
	struct common_audit_data ad;
5092
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5093 5094 5095 5096 5097 5098 5099 5100
	int rc;

	rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
	if (rc)
		return rc;

	isec = shp->shm_perm.security;

5101
	ad.type = LSM_AUDIT_DATA_IPC;
5102
	ad.u.ipc_id = shp->shm_perm.key;
L
Linus Torvalds 已提交
5103

5104
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5105 5106 5107 5108 5109 5110 5111 5112 5113 5114 5115 5116 5117 5118 5119 5120
			  SHM__CREATE, &ad);
	if (rc) {
		ipc_free_security(&shp->shm_perm);
		return rc;
	}
	return 0;
}

static void selinux_shm_free_security(struct shmid_kernel *shp)
{
	ipc_free_security(&shp->shm_perm);
}

static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
{
	struct ipc_security_struct *isec;
5121
	struct common_audit_data ad;
5122
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5123 5124 5125

	isec = shp->shm_perm.security;

5126
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5127 5128
	ad.u.ipc_id = shp->shm_perm.key;

5129
	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5130 5131 5132 5133 5134 5135 5136 5137 5138
			    SHM__ASSOCIATE, &ad);
}

/* Note, at this point, shp is locked down */
static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
{
	int perms;
	int err;

5139
	switch (cmd) {
L
Linus Torvalds 已提交
5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161
	case IPC_INFO:
	case SHM_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	case IPC_STAT:
	case SHM_STAT:
		perms = SHM__GETATTR | SHM__ASSOCIATE;
		break;
	case IPC_SET:
		perms = SHM__SETATTR;
		break;
	case SHM_LOCK:
	case SHM_UNLOCK:
		perms = SHM__LOCK;
		break;
	case IPC_RMID:
		perms = SHM__DESTROY;
		break;
	default:
		return 0;
	}

5162
	err = ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173 5174 5175
	return err;
}

static int selinux_shm_shmat(struct shmid_kernel *shp,
			     char __user *shmaddr, int shmflg)
{
	u32 perms;

	if (shmflg & SHM_RDONLY)
		perms = SHM__READ;
	else
		perms = SHM__READ | SHM__WRITE;

5176
	return ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5177 5178 5179 5180 5181 5182
}

/* Semaphore security operations */
static int selinux_sem_alloc_security(struct sem_array *sma)
{
	struct ipc_security_struct *isec;
5183
	struct common_audit_data ad;
5184
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5185 5186 5187 5188 5189 5190 5191 5192
	int rc;

	rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
	if (rc)
		return rc;

	isec = sma->sem_perm.security;

5193
	ad.type = LSM_AUDIT_DATA_IPC;
5194
	ad.u.ipc_id = sma->sem_perm.key;
L
Linus Torvalds 已提交
5195

5196
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5197 5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212
			  SEM__CREATE, &ad);
	if (rc) {
		ipc_free_security(&sma->sem_perm);
		return rc;
	}
	return 0;
}

static void selinux_sem_free_security(struct sem_array *sma)
{
	ipc_free_security(&sma->sem_perm);
}

static int selinux_sem_associate(struct sem_array *sma, int semflg)
{
	struct ipc_security_struct *isec;
5213
	struct common_audit_data ad;
5214
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5215 5216 5217

	isec = sma->sem_perm.security;

5218
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5219 5220
	ad.u.ipc_id = sma->sem_perm.key;

5221
	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5222 5223 5224 5225 5226 5227 5228 5229 5230
			    SEM__ASSOCIATE, &ad);
}

/* Note, at this point, sma is locked down */
static int selinux_sem_semctl(struct sem_array *sma, int cmd)
{
	int err;
	u32 perms;

5231
	switch (cmd) {
L
Linus Torvalds 已提交
5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262
	case IPC_INFO:
	case SEM_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	case GETPID:
	case GETNCNT:
	case GETZCNT:
		perms = SEM__GETATTR;
		break;
	case GETVAL:
	case GETALL:
		perms = SEM__READ;
		break;
	case SETVAL:
	case SETALL:
		perms = SEM__WRITE;
		break;
	case IPC_RMID:
		perms = SEM__DESTROY;
		break;
	case IPC_SET:
		perms = SEM__SETATTR;
		break;
	case IPC_STAT:
	case SEM_STAT:
		perms = SEM__GETATTR | SEM__ASSOCIATE;
		break;
	default:
		return 0;
	}

5263
	err = ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5264 5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276
	return err;
}

static int selinux_sem_semop(struct sem_array *sma,
			     struct sembuf *sops, unsigned nsops, int alter)
{
	u32 perms;

	if (alter)
		perms = SEM__READ | SEM__WRITE;
	else
		perms = SEM__READ;

5277
	return ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291 5292
}

static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
{
	u32 av = 0;

	av = 0;
	if (flag & S_IRUGO)
		av |= IPC__UNIX_READ;
	if (flag & S_IWUGO)
		av |= IPC__UNIX_WRITE;

	if (av == 0)
		return 0;

5293
	return ipc_has_perm(ipcp, av);
L
Linus Torvalds 已提交
5294 5295
}

5296 5297 5298 5299 5300 5301
static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
{
	struct ipc_security_struct *isec = ipcp->security;
	*secid = isec->sid;
}

5302
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
L
Linus Torvalds 已提交
5303 5304 5305 5306 5307 5308
{
	if (inode)
		inode_doinit_with_dentry(inode, dentry);
}

static int selinux_getprocattr(struct task_struct *p,
5309
			       char *name, char **value)
L
Linus Torvalds 已提交
5310
{
5311
	const struct task_security_struct *__tsec;
5312
	u32 sid;
L
Linus Torvalds 已提交
5313
	int error;
5314
	unsigned len;
L
Linus Torvalds 已提交
5315 5316

	if (current != p) {
5317
		error = current_has_perm(p, PROCESS__GETATTR);
L
Linus Torvalds 已提交
5318 5319 5320 5321
		if (error)
			return error;
	}

5322 5323
	rcu_read_lock();
	__tsec = __task_cred(p)->security;
L
Linus Torvalds 已提交
5324 5325

	if (!strcmp(name, "current"))
5326
		sid = __tsec->sid;
L
Linus Torvalds 已提交
5327
	else if (!strcmp(name, "prev"))
5328
		sid = __tsec->osid;
L
Linus Torvalds 已提交
5329
	else if (!strcmp(name, "exec"))
5330
		sid = __tsec->exec_sid;
L
Linus Torvalds 已提交
5331
	else if (!strcmp(name, "fscreate"))
5332
		sid = __tsec->create_sid;
5333
	else if (!strcmp(name, "keycreate"))
5334
		sid = __tsec->keycreate_sid;
5335
	else if (!strcmp(name, "sockcreate"))
5336
		sid = __tsec->sockcreate_sid;
L
Linus Torvalds 已提交
5337
	else
5338 5339
		goto invalid;
	rcu_read_unlock();
L
Linus Torvalds 已提交
5340 5341 5342 5343

	if (!sid)
		return 0;

5344 5345 5346 5347
	error = security_sid_to_context(sid, value, &len);
	if (error)
		return error;
	return len;
5348 5349 5350 5351

invalid:
	rcu_read_unlock();
	return -EINVAL;
L
Linus Torvalds 已提交
5352 5353 5354 5355 5356 5357
}

static int selinux_setprocattr(struct task_struct *p,
			       char *name, void *value, size_t size)
{
	struct task_security_struct *tsec;
R
Roland McGrath 已提交
5358
	struct task_struct *tracer;
D
David Howells 已提交
5359 5360
	struct cred *new;
	u32 sid = 0, ptsid;
L
Linus Torvalds 已提交
5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375
	int error;
	char *str = value;

	if (current != p) {
		/* SELinux only allows a process to change its own
		   security attributes. */
		return -EACCES;
	}

	/*
	 * Basic control over ability to set these attributes at all.
	 * current == p, but we'll pass them separately in case the
	 * above restriction is ever removed.
	 */
	if (!strcmp(name, "exec"))
5376
		error = current_has_perm(p, PROCESS__SETEXEC);
L
Linus Torvalds 已提交
5377
	else if (!strcmp(name, "fscreate"))
5378
		error = current_has_perm(p, PROCESS__SETFSCREATE);
5379
	else if (!strcmp(name, "keycreate"))
5380
		error = current_has_perm(p, PROCESS__SETKEYCREATE);
5381
	else if (!strcmp(name, "sockcreate"))
5382
		error = current_has_perm(p, PROCESS__SETSOCKCREATE);
L
Linus Torvalds 已提交
5383
	else if (!strcmp(name, "current"))
5384
		error = current_has_perm(p, PROCESS__SETCURRENT);
L
Linus Torvalds 已提交
5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396
	else
		error = -EINVAL;
	if (error)
		return error;

	/* Obtain a SID for the context, if one was specified. */
	if (size && str[1] && str[1] != '\n') {
		if (str[size-1] == '\n') {
			str[size-1] = 0;
			size--;
		}
		error = security_context_to_sid(value, size, &sid);
5397
		if (error == -EINVAL && !strcmp(name, "fscreate")) {
5398 5399 5400 5401 5402 5403 5404 5405 5406 5407 5408 5409 5410 5411 5412
			if (!capable(CAP_MAC_ADMIN)) {
				struct audit_buffer *ab;
				size_t audit_size;

				/* We strip a nul only if it is at the end, otherwise the
				 * context contains a nul and we should audit that */
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
				ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
				audit_log_format(ab, "op=fscreate invalid_context=");
				audit_log_n_untrustedstring(ab, value, audit_size);
				audit_log_end(ab);

5413
				return error;
5414
			}
5415 5416 5417
			error = security_context_to_sid_force(value, size,
							      &sid);
		}
L
Linus Torvalds 已提交
5418 5419 5420 5421
		if (error)
			return error;
	}

D
David Howells 已提交
5422 5423 5424 5425
	new = prepare_creds();
	if (!new)
		return -ENOMEM;

L
Linus Torvalds 已提交
5426 5427 5428
	/* Permission checking based on the specified context is
	   performed during the actual operation (execve,
	   open/mkdir/...), when we know the full context of the
D
David Howells 已提交
5429
	   operation.  See selinux_bprm_set_creds for the execve
L
Linus Torvalds 已提交
5430 5431
	   checks and may_create for the file creation checks. The
	   operation will then fail if the context is not permitted. */
D
David Howells 已提交
5432 5433
	tsec = new->security;
	if (!strcmp(name, "exec")) {
L
Linus Torvalds 已提交
5434
		tsec->exec_sid = sid;
D
David Howells 已提交
5435
	} else if (!strcmp(name, "fscreate")) {
L
Linus Torvalds 已提交
5436
		tsec->create_sid = sid;
D
David Howells 已提交
5437
	} else if (!strcmp(name, "keycreate")) {
5438 5439
		error = may_create_key(sid, p);
		if (error)
D
David Howells 已提交
5440
			goto abort_change;
5441
		tsec->keycreate_sid = sid;
D
David Howells 已提交
5442
	} else if (!strcmp(name, "sockcreate")) {
5443
		tsec->sockcreate_sid = sid;
D
David Howells 已提交
5444 5445
	} else if (!strcmp(name, "current")) {
		error = -EINVAL;
L
Linus Torvalds 已提交
5446
		if (sid == 0)
D
David Howells 已提交
5447 5448 5449 5450
			goto abort_change;

		/* Only allow single threaded processes to change context */
		error = -EPERM;
5451
		if (!current_is_single_threaded()) {
D
David Howells 已提交
5452 5453 5454
			error = security_bounded_transition(tsec->sid, sid);
			if (error)
				goto abort_change;
5455
		}
L
Linus Torvalds 已提交
5456 5457 5458

		/* Check permissions for the transition. */
		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5459
				     PROCESS__DYNTRANSITION, NULL);
L
Linus Torvalds 已提交
5460
		if (error)
D
David Howells 已提交
5461
			goto abort_change;
L
Linus Torvalds 已提交
5462 5463 5464

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and fail. */
D
David Howells 已提交
5465
		ptsid = 0;
L
Linus Torvalds 已提交
5466
		task_lock(p);
5467
		tracer = ptrace_parent(p);
D
David Howells 已提交
5468 5469 5470 5471 5472 5473 5474
		if (tracer)
			ptsid = task_sid(tracer);
		task_unlock(p);

		if (tracer) {
			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
					     PROCESS__PTRACE, NULL);
L
Linus Torvalds 已提交
5475
			if (error)
D
David Howells 已提交
5476
				goto abort_change;
L
Linus Torvalds 已提交
5477 5478
		}

D
David Howells 已提交
5479 5480 5481 5482 5483 5484 5485
		tsec->sid = sid;
	} else {
		error = -EINVAL;
		goto abort_change;
	}

	commit_creds(new);
L
Linus Torvalds 已提交
5486
	return size;
D
David Howells 已提交
5487 5488 5489 5490

abort_change:
	abort_creds(new);
	return error;
L
Linus Torvalds 已提交
5491 5492
}

5493 5494 5495 5496 5497
static int selinux_ismaclabel(const char *name)
{
	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
}

5498 5499 5500 5501 5502
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
	return security_sid_to_context(secid, secdata, seclen);
}

5503
static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5504 5505 5506 5507
{
	return security_context_to_sid(secdata, seclen, secid);
}

5508 5509
static void selinux_release_secctx(char *secdata, u32 seclen)
{
5510
	kfree(secdata);
5511 5512
}

5513 5514 5515 5516 5517 5518 5519 5520 5521 5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537 5538
/*
 *	called with inode->i_mutex locked
 */
static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
{
	return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
}

/*
 *	called with inode->i_mutex locked
 */
static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
{
	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
}

static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
{
	int len = 0;
	len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
						ctx, true);
	if (len < 0)
		return len;
	*ctxlen = len;
	return 0;
}
5539 5540
#ifdef CONFIG_KEYS

D
David Howells 已提交
5541
static int selinux_key_alloc(struct key *k, const struct cred *cred,
5542
			     unsigned long flags)
5543
{
D
David Howells 已提交
5544
	const struct task_security_struct *tsec;
5545 5546 5547 5548 5549 5550
	struct key_security_struct *ksec;

	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
	if (!ksec)
		return -ENOMEM;

D
David Howells 已提交
5551 5552 5553
	tsec = cred->security;
	if (tsec->keycreate_sid)
		ksec->sid = tsec->keycreate_sid;
5554
	else
D
David Howells 已提交
5555
		ksec->sid = tsec->sid;
5556

5557
	k->security = ksec;
5558 5559 5560 5561 5562 5563 5564 5565 5566 5567 5568 5569
	return 0;
}

static void selinux_key_free(struct key *k)
{
	struct key_security_struct *ksec = k->security;

	k->security = NULL;
	kfree(ksec);
}

static int selinux_key_permission(key_ref_t key_ref,
D
David Howells 已提交
5570 5571
				  const struct cred *cred,
				  key_perm_t perm)
5572 5573 5574
{
	struct key *key;
	struct key_security_struct *ksec;
5575
	u32 sid;
5576 5577 5578 5579 5580 5581 5582

	/* if no specific permissions are requested, we skip the
	   permission check. No serious, additional covert channels
	   appear to be created. */
	if (perm == 0)
		return 0;

D
David Howells 已提交
5583
	sid = cred_sid(cred);
5584 5585 5586 5587 5588

	key = key_ref_to_ptr(key_ref);
	ksec = key->security;

	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5589 5590
}

5591 5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604
static int selinux_key_getsecurity(struct key *key, char **_buffer)
{
	struct key_security_struct *ksec = key->security;
	char *context = NULL;
	unsigned len;
	int rc;

	rc = security_sid_to_context(ksec->sid, &context, &len);
	if (!rc)
		rc = len;
	*_buffer = context;
	return rc;
}

5605 5606
#endif

L
Linus Torvalds 已提交
5607
static struct security_operations selinux_ops = {
5608 5609
	.name =				"selinux",

5610
	.ptrace_access_check =		selinux_ptrace_access_check,
5611
	.ptrace_traceme =		selinux_ptrace_traceme,
L
Linus Torvalds 已提交
5612
	.capget =			selinux_capget,
D
David Howells 已提交
5613
	.capset =			selinux_capset,
L
Linus Torvalds 已提交
5614 5615 5616 5617 5618 5619 5620 5621
	.capable =			selinux_capable,
	.quotactl =			selinux_quotactl,
	.quota_on =			selinux_quota_on,
	.syslog =			selinux_syslog,
	.vm_enough_memory =		selinux_vm_enough_memory,

	.netlink_send =			selinux_netlink_send,

5622 5623 5624
	.bprm_set_creds =		selinux_bprm_set_creds,
	.bprm_committing_creds =	selinux_bprm_committing_creds,
	.bprm_committed_creds =		selinux_bprm_committed_creds,
L
Linus Torvalds 已提交
5625 5626 5627 5628 5629
	.bprm_secureexec =		selinux_bprm_secureexec,

	.sb_alloc_security =		selinux_sb_alloc_security,
	.sb_free_security =		selinux_sb_free_security,
	.sb_copy_data =			selinux_sb_copy_data,
5630
	.sb_remount =			selinux_sb_remount,
5631
	.sb_kern_mount =		selinux_sb_kern_mount,
5632
	.sb_show_options =		selinux_sb_show_options,
L
Linus Torvalds 已提交
5633 5634 5635
	.sb_statfs =			selinux_sb_statfs,
	.sb_mount =			selinux_mount,
	.sb_umount =			selinux_umount,
5636
	.sb_set_mnt_opts =		selinux_set_mnt_opts,
5637
	.sb_clone_mnt_opts =		selinux_sb_clone_mnt_opts,
5638 5639
	.sb_parse_opts_str = 		selinux_parse_opts_str,

5640
	.dentry_init_security =		selinux_dentry_init_security,
L
Linus Torvalds 已提交
5641 5642 5643

	.inode_alloc_security =		selinux_inode_alloc_security,
	.inode_free_security =		selinux_inode_free_security,
5644
	.inode_init_security =		selinux_inode_init_security,
L
Linus Torvalds 已提交
5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662
	.inode_create =			selinux_inode_create,
	.inode_link =			selinux_inode_link,
	.inode_unlink =			selinux_inode_unlink,
	.inode_symlink =		selinux_inode_symlink,
	.inode_mkdir =			selinux_inode_mkdir,
	.inode_rmdir =			selinux_inode_rmdir,
	.inode_mknod =			selinux_inode_mknod,
	.inode_rename =			selinux_inode_rename,
	.inode_readlink =		selinux_inode_readlink,
	.inode_follow_link =		selinux_inode_follow_link,
	.inode_permission =		selinux_inode_permission,
	.inode_setattr =		selinux_inode_setattr,
	.inode_getattr =		selinux_inode_getattr,
	.inode_setxattr =		selinux_inode_setxattr,
	.inode_post_setxattr =		selinux_inode_post_setxattr,
	.inode_getxattr =		selinux_inode_getxattr,
	.inode_listxattr =		selinux_inode_listxattr,
	.inode_removexattr =		selinux_inode_removexattr,
5663 5664 5665
	.inode_getsecurity =		selinux_inode_getsecurity,
	.inode_setsecurity =		selinux_inode_setsecurity,
	.inode_listsecurity =		selinux_inode_listsecurity,
5666
	.inode_getsecid =		selinux_inode_getsecid,
L
Linus Torvalds 已提交
5667 5668 5669 5670 5671

	.file_permission =		selinux_file_permission,
	.file_alloc_security =		selinux_file_alloc_security,
	.file_free_security =		selinux_file_free_security,
	.file_ioctl =			selinux_file_ioctl,
5672 5673
	.mmap_file =			selinux_mmap_file,
	.mmap_addr =			selinux_mmap_addr,
L
Linus Torvalds 已提交
5674 5675 5676 5677 5678 5679 5680
	.file_mprotect =		selinux_file_mprotect,
	.file_lock =			selinux_file_lock,
	.file_fcntl =			selinux_file_fcntl,
	.file_set_fowner =		selinux_file_set_fowner,
	.file_send_sigiotask =		selinux_file_send_sigiotask,
	.file_receive =			selinux_file_receive,

5681
	.file_open =			selinux_file_open,
5682

L
Linus Torvalds 已提交
5683
	.task_create =			selinux_task_create,
5684
	.cred_alloc_blank =		selinux_cred_alloc_blank,
5685
	.cred_free =			selinux_cred_free,
D
David Howells 已提交
5686
	.cred_prepare =			selinux_cred_prepare,
5687
	.cred_transfer =		selinux_cred_transfer,
5688 5689
	.kernel_act_as =		selinux_kernel_act_as,
	.kernel_create_files_as =	selinux_kernel_create_files_as,
5690
	.kernel_module_request =	selinux_kernel_module_request,
L
Linus Torvalds 已提交
5691 5692
	.task_setpgid =			selinux_task_setpgid,
	.task_getpgid =			selinux_task_getpgid,
5693
	.task_getsid =			selinux_task_getsid,
5694
	.task_getsecid =		selinux_task_getsecid,
L
Linus Torvalds 已提交
5695
	.task_setnice =			selinux_task_setnice,
5696
	.task_setioprio =		selinux_task_setioprio,
5697
	.task_getioprio =		selinux_task_getioprio,
L
Linus Torvalds 已提交
5698 5699 5700
	.task_setrlimit =		selinux_task_setrlimit,
	.task_setscheduler =		selinux_task_setscheduler,
	.task_getscheduler =		selinux_task_getscheduler,
5701
	.task_movememory =		selinux_task_movememory,
L
Linus Torvalds 已提交
5702 5703
	.task_kill =			selinux_task_kill,
	.task_wait =			selinux_task_wait,
5704
	.task_to_inode =		selinux_task_to_inode,
L
Linus Torvalds 已提交
5705 5706

	.ipc_permission =		selinux_ipc_permission,
5707
	.ipc_getsecid =			selinux_ipc_getsecid,
L
Linus Torvalds 已提交
5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724

	.msg_msg_alloc_security =	selinux_msg_msg_alloc_security,
	.msg_msg_free_security =	selinux_msg_msg_free_security,

	.msg_queue_alloc_security =	selinux_msg_queue_alloc_security,
	.msg_queue_free_security =	selinux_msg_queue_free_security,
	.msg_queue_associate =		selinux_msg_queue_associate,
	.msg_queue_msgctl =		selinux_msg_queue_msgctl,
	.msg_queue_msgsnd =		selinux_msg_queue_msgsnd,
	.msg_queue_msgrcv =		selinux_msg_queue_msgrcv,

	.shm_alloc_security =		selinux_shm_alloc_security,
	.shm_free_security =		selinux_shm_free_security,
	.shm_associate =		selinux_shm_associate,
	.shm_shmctl =			selinux_shm_shmctl,
	.shm_shmat =			selinux_shm_shmat,

5725 5726
	.sem_alloc_security =		selinux_sem_alloc_security,
	.sem_free_security =		selinux_sem_free_security,
L
Linus Torvalds 已提交
5727 5728 5729 5730
	.sem_associate =		selinux_sem_associate,
	.sem_semctl =			selinux_sem_semctl,
	.sem_semop =			selinux_sem_semop,

5731
	.d_instantiate =		selinux_d_instantiate,
L
Linus Torvalds 已提交
5732

5733 5734
	.getprocattr =			selinux_getprocattr,
	.setprocattr =			selinux_setprocattr,
L
Linus Torvalds 已提交
5735

5736
	.ismaclabel =			selinux_ismaclabel,
5737
	.secid_to_secctx =		selinux_secid_to_secctx,
5738
	.secctx_to_secid =		selinux_secctx_to_secid,
5739
	.release_secctx =		selinux_release_secctx,
5740 5741 5742
	.inode_notifysecctx =		selinux_inode_notifysecctx,
	.inode_setsecctx =		selinux_inode_setsecctx,
	.inode_getsecctx =		selinux_inode_getsecctx,
5743

5744
	.unix_stream_connect =		selinux_socket_unix_stream_connect,
L
Linus Torvalds 已提交
5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760
	.unix_may_send =		selinux_socket_unix_may_send,

	.socket_create =		selinux_socket_create,
	.socket_post_create =		selinux_socket_post_create,
	.socket_bind =			selinux_socket_bind,
	.socket_connect =		selinux_socket_connect,
	.socket_listen =		selinux_socket_listen,
	.socket_accept =		selinux_socket_accept,
	.socket_sendmsg =		selinux_socket_sendmsg,
	.socket_recvmsg =		selinux_socket_recvmsg,
	.socket_getsockname =		selinux_socket_getsockname,
	.socket_getpeername =		selinux_socket_getpeername,
	.socket_getsockopt =		selinux_socket_getsockopt,
	.socket_setsockopt =		selinux_socket_setsockopt,
	.socket_shutdown =		selinux_socket_shutdown,
	.socket_sock_rcv_skb =		selinux_socket_sock_rcv_skb,
C
Catherine Zhang 已提交
5761 5762
	.socket_getpeersec_stream =	selinux_socket_getpeersec_stream,
	.socket_getpeersec_dgram =	selinux_socket_getpeersec_dgram,
L
Linus Torvalds 已提交
5763 5764
	.sk_alloc_security =		selinux_sk_alloc_security,
	.sk_free_security =		selinux_sk_free_security,
5765
	.sk_clone_security =		selinux_sk_clone_security,
5766
	.sk_getsecid =			selinux_sk_getsecid,
5767 5768 5769
	.sock_graft =			selinux_sock_graft,
	.inet_conn_request =		selinux_inet_conn_request,
	.inet_csk_clone =		selinux_inet_csk_clone,
5770
	.inet_conn_established =	selinux_inet_conn_established,
5771 5772 5773
	.secmark_relabel_packet =	selinux_secmark_relabel_packet,
	.secmark_refcount_inc =		selinux_secmark_refcount_inc,
	.secmark_refcount_dec =		selinux_secmark_refcount_dec,
5774
	.req_classify_flow =		selinux_req_classify_flow,
5775 5776
	.tun_dev_alloc_security =	selinux_tun_dev_alloc_security,
	.tun_dev_free_security =	selinux_tun_dev_free_security,
5777
	.tun_dev_create =		selinux_tun_dev_create,
5778
	.tun_dev_attach_queue =		selinux_tun_dev_attach_queue,
5779
	.tun_dev_attach =		selinux_tun_dev_attach,
5780
	.tun_dev_open =			selinux_tun_dev_open,
5781
	.skb_owned_by =			selinux_skb_owned_by,
5782 5783 5784 5785 5786

#ifdef CONFIG_SECURITY_NETWORK_XFRM
	.xfrm_policy_alloc_security =	selinux_xfrm_policy_alloc,
	.xfrm_policy_clone_security =	selinux_xfrm_policy_clone,
	.xfrm_policy_free_security =	selinux_xfrm_policy_free,
C
Catherine Zhang 已提交
5787
	.xfrm_policy_delete_security =	selinux_xfrm_policy_delete,
5788 5789
	.xfrm_state_alloc_security =	selinux_xfrm_state_alloc,
	.xfrm_state_free_security =	selinux_xfrm_state_free,
C
Catherine Zhang 已提交
5790
	.xfrm_state_delete_security =	selinux_xfrm_state_delete,
5791
	.xfrm_policy_lookup =		selinux_xfrm_policy_lookup,
5792 5793
	.xfrm_state_pol_flow_match =	selinux_xfrm_state_pol_flow_match,
	.xfrm_decode_session =		selinux_xfrm_decode_session,
L
Linus Torvalds 已提交
5794
#endif
5795 5796

#ifdef CONFIG_KEYS
5797 5798 5799
	.key_alloc =			selinux_key_alloc,
	.key_free =			selinux_key_free,
	.key_permission =		selinux_key_permission,
5800
	.key_getsecurity =		selinux_key_getsecurity,
5801
#endif
5802 5803 5804 5805 5806 5807 5808

#ifdef CONFIG_AUDIT
	.audit_rule_init =		selinux_audit_rule_init,
	.audit_rule_known =		selinux_audit_rule_known,
	.audit_rule_match =		selinux_audit_rule_match,
	.audit_rule_free =		selinux_audit_rule_free,
#endif
L
Linus Torvalds 已提交
5809 5810 5811 5812
};

static __init int selinux_init(void)
{
5813 5814 5815 5816 5817
	if (!security_module_enable(&selinux_ops)) {
		selinux_enabled = 0;
		return 0;
	}

L
Linus Torvalds 已提交
5818 5819 5820 5821 5822 5823 5824 5825
	if (!selinux_enabled) {
		printk(KERN_INFO "SELinux:  Disabled at boot.\n");
		return 0;
	}

	printk(KERN_INFO "SELinux:  Initializing.\n");

	/* Set the security state for the initial task. */
D
David Howells 已提交
5826
	cred_init_security();
L
Linus Torvalds 已提交
5827

5828 5829
	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);

5830 5831
	sel_inode_cache = kmem_cache_create("selinux_inode_security",
					    sizeof(struct inode_security_struct),
5832
					    0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
5833 5834
	avc_init();

5835
	if (register_security(&selinux_ops))
L
Linus Torvalds 已提交
5836 5837
		panic("SELinux: Unable to register with kernel.\n");

5838
	if (selinux_enforcing)
5839
		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
5840
	else
5841
		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
5842

L
Linus Torvalds 已提交
5843 5844 5845
	return 0;
}

5846 5847 5848 5849 5850
static void delayed_superblock_init(struct super_block *sb, void *unused)
{
	superblock_doinit(sb, NULL);
}

L
Linus Torvalds 已提交
5851 5852
void selinux_complete_init(void)
{
5853
	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
L
Linus Torvalds 已提交
5854 5855

	/* Set up any superblocks initialized prior to the policy load. */
5856
	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
5857
	iterate_supers(delayed_superblock_init, NULL);
L
Linus Torvalds 已提交
5858 5859 5860 5861 5862 5863
}

/* SELinux requires early initialization in order to label
   all processes and objects when they are created. */
security_initcall(selinux_init);

5864
#if defined(CONFIG_NETFILTER)
L
Linus Torvalds 已提交
5865

5866 5867 5868 5869
static struct nf_hook_ops selinux_ipv4_ops[] = {
	{
		.hook =		selinux_ipv4_postroute,
		.owner =	THIS_MODULE,
5870
		.pf =		NFPROTO_IPV4,
5871 5872 5873 5874 5875 5876
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv4_forward,
		.owner =	THIS_MODULE,
5877
		.pf =		NFPROTO_IPV4,
5878 5879
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
5880 5881 5882 5883
	},
	{
		.hook =		selinux_ipv4_output,
		.owner =	THIS_MODULE,
5884
		.pf =		NFPROTO_IPV4,
5885 5886
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
5887
	}
L
Linus Torvalds 已提交
5888 5889 5890 5891
};

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

5892 5893 5894 5895
static struct nf_hook_ops selinux_ipv6_ops[] = {
	{
		.hook =		selinux_ipv6_postroute,
		.owner =	THIS_MODULE,
5896
		.pf =		NFPROTO_IPV6,
5897 5898 5899 5900 5901 5902
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP6_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv6_forward,
		.owner =	THIS_MODULE,
5903
		.pf =		NFPROTO_IPV6,
5904 5905 5906
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
	}
L
Linus Torvalds 已提交
5907 5908 5909 5910 5911 5912 5913 5914 5915 5916
};

#endif	/* IPV6 */

static int __init selinux_nf_ip_init(void)
{
	int err = 0;

	if (!selinux_enabled)
		goto out;
5917 5918 5919

	printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");

5920 5921 5922
	err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
	if (err)
		panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
L
Linus Torvalds 已提交
5923 5924

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5925 5926 5927
	err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
	if (err)
		panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
L
Linus Torvalds 已提交
5928
#endif	/* IPV6 */
5929

L
Linus Torvalds 已提交
5930 5931 5932 5933 5934 5935 5936 5937 5938
out:
	return err;
}

__initcall(selinux_nf_ip_init);

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static void selinux_nf_ip_exit(void)
{
5939
	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
L
Linus Torvalds 已提交
5940

5941
	nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
L
Linus Torvalds 已提交
5942
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5943
	nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
L
Linus Torvalds 已提交
5944 5945 5946 5947
#endif	/* IPV6 */
}
#endif

5948
#else /* CONFIG_NETFILTER */
L
Linus Torvalds 已提交
5949 5950 5951 5952 5953

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
#define selinux_nf_ip_exit()
#endif

5954
#endif /* CONFIG_NETFILTER */
L
Linus Torvalds 已提交
5955 5956

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
5957 5958
static int selinux_disabled;

L
Linus Torvalds 已提交
5959 5960 5961 5962 5963 5964 5965 5966 5967 5968 5969 5970 5971 5972 5973
int selinux_disable(void)
{
	if (ss_initialized) {
		/* Not permitted after initial policy load. */
		return -EINVAL;
	}

	if (selinux_disabled) {
		/* Only do this once. */
		return -EINVAL;
	}

	printk(KERN_INFO "SELinux:  Disabled at runtime.\n");

	selinux_disabled = 1;
5974
	selinux_enabled = 0;
L
Linus Torvalds 已提交
5975

5976
	reset_security_ops();
L
Linus Torvalds 已提交
5977

5978 5979 5980
	/* Try to destroy the avc node cache */
	avc_disable();

L
Linus Torvalds 已提交
5981 5982 5983 5984 5985 5986 5987 5988 5989
	/* Unregister netfilter hooks. */
	selinux_nf_ip_exit();

	/* Unregister selinuxfs. */
	exit_sel_fs();

	return 0;
}
#endif