[Bluetooth] Check if DLC is still attached to the TTY

If the DLC device is no longer attached to the TTY device, then it
makes no sense to go through with changing the termios settings.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index 5833b87c51cf..b8e3a5f1c8a8 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -765,6 +765,9 @@ static void rfcomm_tty_set_termios(struct tty_struct *tty, struct termios *old)
 
         BT_DBG("tty %p termios %p", tty, old);
 
+        if (!dev)
+                return;
+
         /* Handle turning off CRTSCTS */
         if ((old->c_cflag & CRTSCTS) && !(new->c_cflag & CRTSCTS)) 
                 BT_DBG("Turning off CRTSCTS unsupported");