[Bluetooth] Avoid NULL pointer dereference with tty->driver

This patch checks for tty->driver before trying to call flush_buffer().

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

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 1994270c16e1..93ba25b7ea32 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -191,7 +191,7 @@ static int hci_uart_flush(struct hci_dev *hdev)
 
         /* Flush any pending characters in the driver and discipline. */
         tty_ldisc_flush(tty);
-        if (tty->driver->flush_buffer)
+        if (tty->driver && tty->driver->flush_buffer)
                 tty->driver->flush_buffer(tty);
 
         if (test_bit(HCI_UART_PROTO_SET, &hu->flags))
@@ -290,7 +290,7 @@ static int hci_uart_tty_open(struct tty_struct *tty)
         if (tty->ldisc.flush_buffer)
                 tty->ldisc.flush_buffer(tty);
 
-        if (tty->driver->flush_buffer)
+        if (tty->driver && tty->driver->flush_buffer)
                 tty->driver->flush_buffer(tty);
 
         return 0;