diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
old mode 100644
new mode 100755
index 860b2ce..359a3bd
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -6923,6 +6923,7 @@
 
     @Override
     public void unofferNetwork(@NonNull final INetworkOfferCallback callback) {
+        Objects.requireNonNull(callback);
         mHandler.sendMessage(mHandler.obtainMessage(EVENT_UNREGISTER_NETWORK_OFFER, callback));
     }