[Bluetooth] Fix NULL pointer dereference in HCI line discipline

Normally a serial Bluetooth device is opened, TIOSETD'ed to N_HCI line
discipline, HCIUARTSETPROTO'ed and finally closed. In case the device
fails to HCIUARTSETPROTO, closing it produces a NULL pointer dereference.

Signed-off-by: Ohad Ben-Cohen <ohad@bencohen.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 75c15085f81f..e8ae0d7e7716 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -307,7 +307,9 @@ static void hci_uart_tty_close(struct tty_struct *tty)
 
         if (hu) {
                 struct hci_dev *hdev = hu->hdev;
-                hci_uart_close(hdev);
+
+                if (hdev)
+                        hci_uart_close(hdev);
 
                 if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) {
                         hu->proto->close(hu);