Bluetooth: Restrict blocked device check in l2cap_recv_frame to LE

BR/EDR has the connection request and connection request rejection, but
LE doesn't have anything similar. We still request LE connections to
blocked devices to be disconnected but it's possible that ACL data slips
through before that. The check in l2cap_recv_frame really only needs to
be for LE and not BR/EDR because of this.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

net/bluetooth/l2cap_core.c

@@ -6914,7 +6914,11 @@ static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
 		return;
 	}
 
-	if (hci_blacklist_lookup(hcon->hdev, &hcon->dst,
+	/* Since we can't actively block incoming LE connections we must
+	 * at least ensure that we ignore incoming data from them.
+	 */
+	if (hcon->type == LE_LINK &&
+	    hci_blacklist_lookup(hcon->hdev, &hcon->dst,
 				 bdaddr_type(hcon, hcon->dst_type))) {
 		kfree_skb(skb);
 		return;