[PATCH] Bluetooth: hci_ldisc: Add NULL check for tty set_termios operation

[Myungho Jung]

set_termios should not be NULL so return EOPNOTSUPP if tty driver does
not support the operation.
Reported-by: syzbot+a950165cbb86bdd02...@syzkaller.appspotmail.com
Signed-off-by: Myungho Jung <mhju...@gmail.com>
---
 drivers/bluetooth/hci_ldisc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index fbf7b4df23ab..44ac2e9494cc 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -474,10 +474,10 @@ static int hci_uart_tty_open(struct tty_struct *tty)
 
        BT_DBG("tty %p", tty);
 
-       /* Error if the tty has no write op instead of leaving an exploitable
-        * hole
+       /* Error if the tty has no write or set_termios op instead of leaving an
+        * exploitable hole
         */
-       if (tty->ops->write == NULL)
+       if (tty->ops->write == NULL || tty->ops->set_termios == NULL)
                return -EOPNOTSUPP;
 
        hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL);
-- 
2.17.1