[PATCH] tty: hso: Fix potential null pointer dereference

[Ren Mingshuai]

Generally, the old always points to the address of a ktermios structure,
so old is unlikely to be NULL. Still check it before dereference as
elsewhere.

Signed-off-by: Ren Mingshuai <renmingshuai@xxxxxxxxxx>
---
 drivers/net/usb/hso.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index ce1f6081d582..4ad829ab54d3 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1396,7 +1396,8 @@ static void hso_serial_set_termios(struct tty_struct *tty,
 	if (serial->port.count)
 		_hso_serial_set_termios(tty);
 	else
-		tty->termios = *old;
+		if (old)
+			tty->termios = *old;
 	spin_unlock_irqrestore(&serial->serial_lock, flags);
 
 	/* done */
-- 
2.33.0