diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index c122640..28b5b6d 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -1704,7 +1704,7 @@
         mUserAllContext.registerReceiver(mPackageIntentReceiver, packageIntentFilter,
                 null /* broadcastPermission */, mHandler);
 
-        mNetworkActivityTracker = new LegacyNetworkActivityTracker(mContext, mNetd);
+        mNetworkActivityTracker = new LegacyNetworkActivityTracker(mContext, mNetd, mHandler);
 
         final NetdCallback netdCallback = new NetdCallback();
         try {
@@ -11125,6 +11125,7 @@
         private static final int NO_UID = -1;
         private final Context mContext;
         private final INetd mNetd;
+        private final Handler mHandler;
         private final RemoteCallbackList<INetworkActivityListener> mNetworkActivityListeners =
                 new RemoteCallbackList<>();
         // Indicate the current system default network activity is active or not.
@@ -11143,12 +11144,22 @@
             }
         }
 
-        LegacyNetworkActivityTracker(@NonNull Context context, @NonNull INetd netd) {
+        LegacyNetworkActivityTracker(@NonNull Context context, @NonNull INetd netd,
+                @NonNull Handler handler) {
             mContext = context;
             mNetd = netd;
+            mHandler = handler;
+        }
+
+        private void ensureRunningOnConnectivityServiceThread() {
+            if (mHandler.getLooper().getThread() != Thread.currentThread()) {
+                throw new IllegalStateException("Not running on ConnectivityService thread: "
+                                + Thread.currentThread().getName());
+            }
         }
 
         public void handleReportNetworkActivity(NetworkActivityParams activityParams) {
+            ensureRunningOnConnectivityServiceThread();
             sendDataActivityBroadcast(transportTypeToLegacyType(activityParams.label),
                     activityParams.isActive, activityParams.timestampNs);
             synchronized (mActiveIdleTimers) {
@@ -11309,6 +11320,7 @@
          */
         public void updateDataActivityTracking(NetworkAgentInfo newNetwork,
                 NetworkAgentInfo oldNetwork) {
+            ensureRunningOnConnectivityServiceThread();
             if (newNetwork != null) {
                 setupDataActivityTracking(newNetwork);
             }