Bluetooth: Reset the security level after an authentication failure

When authentication fails for a connection the assumed security level
should be set back to BT_SECURITY_LOW so that subsequent connect
attempts over the same link don't falsely assume that security is
adequate enough.
Signed-off-by: NJohan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_event.c

@@ -1049,6 +1049,8 @@ static inline void hci_auth_complete_evt(struct hci_dev *hdev, struct sk_buff *s
 	if (conn) {
 		if (!ev->status)
 			conn->link_mode |= HCI_LM_AUTH;
+		else
+			conn->sec_level = BT_SECURITY_LOW;
 
 		clear_bit(HCI_CONN_AUTH_PEND, &conn->pend);