Bluetooth: Expire RPA if encryption fails

If encryption fails and we're using an RPA it may be because of a
conflict with another device. To avoid repeated failures the safest
action is to simply mark the RPA as expired so that a new one gets
generated as soon as the connection drops.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_event.c

@@ -2438,6 +2438,12 @@ static void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *skb)
 		}
 	}
 
+	/* We should disregard the current RPA and generate a new one
+	 * whenever the encryption procedure fails.
+	 */
+	if (ev->status && conn->type == LE_LINK)
+		set_bit(HCI_RPA_EXPIRED, &hdev->dev_flags);
+
 	clear_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags);
 
 	if (ev->status && conn->state == BT_CONNECTED) {