--- x/net/bluetooth/hci_core.c
+++ y/net/bluetooth/hci_core.c
@@ -3787,8 +3787,10 @@ static void hci_acldata_packet(struct hc
 	if (conn) {
 		hci_conn_enter_active_mode(conn, BT_POWER_FORCE_ACTIVE_OFF);
 
+		hci_req_sync_lock(hdev);
 		/* Send to upper protocol */
 		l2cap_recv_acldata(conn, skb, flags);
+		hci_req_sync_unlock(hdev);
 		return;
 	} else {
 		bt_dev_err(hdev, "ACL packet for unknown connection handle %d",