diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 9ec12504634368b4f8c49fa43bdf5dc79331175c..a054d03c22e7b7376824927ce577d46644b01f16 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -417,6 +417,10 @@ EXPORT_SYMBOL_GPL(tty_ldisc_flush);
  *	they are not on hot paths so a little discipline won't do
  *	any harm.
  *
+ *	The line discipline-related tty_struct fields are reset to
+ *	prevent the ldisc driver from re-using stale information for
+ *	the new ldisc instance.
+ *
  *	Locking: takes termios_rwsem
  */
 
@@ -425,6 +429,9 @@ static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
 	down_write(&tty->termios_rwsem);
 	tty->termios.c_line = num;
 	up_write(&tty->termios_rwsem);
+
+	tty->disc_data = NULL;
+	tty->receive_room = 0;
 }
 
 /**