diff --git a/adapter/uhdf2/host/src/device_service_stub.c b/adapter/uhdf2/host/src/device_service_stub.c
index 572a6336c13a98523a20a432aa76e0a507b23eca..07e73631c49e6b7c0c9bfecdf3349e50b035d3a1 100644
--- a/adapter/uhdf2/host/src/device_service_stub.c
+++ b/adapter/uhdf2/host/src/device_service_stub.c
@@ -27,13 +27,12 @@ int DeviceServiceStubDispatch(
     struct HdfRemoteService *stub, int code, struct HdfSBuf *data, struct HdfSBuf *reply)
 {
     struct DeviceServiceStub *service = (struct DeviceServiceStub *)stub;
-    struct IDeviceIoService *ioService = service->super.deviceObject.service;
     int ret = HDF_FAILURE;
 
 #ifdef __USER__
     pthread_rwlock_rdlock(&service->super.deviceObject.mutex);
 #endif
-
+    struct IDeviceIoService *ioService = service->super.deviceObject.service;
     if (ioService == NULL) {
 #ifdef __USER__
         pthread_rwlock_unlock(&service->super.deviceObject.mutex);