Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  SELinux: properly handle empty tty_files list

security/selinux/hooks.c

@@ -2126,14 +2126,16 @@ static inline void flush_unauthorized_files(struct files_struct *files)
 	tty = get_current_tty();
 	if (tty) {
 		file_list_lock();
-		file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
-		if (file) {
+		if (!list_empty(&tty->tty_files)) {
+			struct inode *inode;
+
 			/* Revalidate access to controlling tty.
 			   Use inode_has_perm on the tty inode 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. */
-			struct inode *inode = file->f_path.dentry->d_inode;
+			file = list_first_entry(&tty->tty_files, struct file, f_u.fu_list);
+			inode = file->f_path.dentry->d_inode;
 			if (inode_has_perm(current, inode,
 					   FILE__READ | FILE__WRITE, NULL)) {
 				drop_tty = 1;