X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Ftty%2Ftty_ldisc.c;h=9bee25cfa0be5e5a39cd00a2aa8e2fd57ac69096;hb=79ae01aa89b569ed599d1263eb26c6b98f039c27;hp=629e3c865072035f14fd4e6ece5a2544bcbf713c;hpb=11c1879e11bacc8d12e2cc4603a73d09db3da3bc;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 629e3c865072..9bee25cfa0be 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;
 }
 
 /**