diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 2fa28c8..3c02be3 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -750,7 +750,37 @@
 	goto out;
 }
 
-static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
+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,
 					struct super_block *newsb)
 {
 	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
@@ -765,14 +795,14 @@
 	 * mount options.  thus we can safely deal with this superblock later
 	 */
 	if (!ss_initialized)
-		return;
+		return 0;
 
 	/* how can we clone if the old one wasn't set up?? */
 	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
 
-	/* if fs is reusing a sb, just let its options stand... */
+	/* if fs is reusing a sb, make sure that the contexts match */
 	if (newsbsec->flags & SE_SBINITIALIZED)
-		return;
+		return selinux_cmp_sb_context(oldsb, newsb);
 
 	mutex_lock(&newsbsec->lock);
 
@@ -805,6 +835,7 @@
 
 	sb_finish_set_opts(newsb);
 	mutex_unlock(&newsbsec->lock);
+	return 0;
 }
 
 static int selinux_parse_opts_str(char *options,