Merge tag 'tty-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull TTY fix from Greg KH:
 "Here is a single tty fix for a reported issue that you wrote the patch
  for :)

  It's been in linux-next for a week or so with no reported issues"

* tag 'tty-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD)

drivers/tty/n_tty.c

@@ -1762,7 +1762,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 
-	if (!old || (old->c_lflag ^ tty->termios.c_lflag) & ICANON) {
+	if (!old || (old->c_lflag ^ tty->termios.c_lflag) & (ICANON | EXTPROC)) {
 		bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
 		ldata->line_start = ldata->read_tail;
 		if (!L_ICANON(tty) || !read_cnt(ldata)) {
@@ -2425,7 +2425,7 @@ static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
 		return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
 	case TIOCINQ:
 		down_write(&tty->termios_rwsem);
-		if (L_ICANON(tty))
+		if (L_ICANON(tty) && !L_EXTPROC(tty))
 			retval = inq_canon(ldata);
 		else
 			retval = read_cnt(ldata);