diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 26debec26b4e..1150de531460 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2304,12 +2304,13 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
 	if (get_user(ch, p))
 		return -EFAULT;
 	tty_audit_tiocsti(tty, ch);
+	tty_buffer_lock_exclusive(tty->port);
 	ld = tty_ldisc_ref_wait(tty);
 	if (!ld)
 		return -EIO;
-	if (ld->ops->receive_buf)
-		ld->ops->receive_buf(tty, &ch, &mbz, 1);
+	tty_ldisc_receive_buf(ld, &ch, &mbz, 1);
 	tty_ldisc_deref(ld);
+	tty_buffer_unlock_exclusive(tty->port);
 	return 0;
 }