Merge "Fix a possible system server crash"

service/src/com/android/server/ConnectivityService.java

@@ -5907,7 +5907,13 @@ public class ConnectivityService extends IConnectivityManager.Stub
         public void binderDied() {
             log("ConnectivityService NetworkRequestInfo binderDied(" +
                     "uid/pid:" + mUid + "/" + mPid + ", " + mBinder + ")");
-            mHandler.post(() -> handleRemoveNetworkRequest(this));
+            // As an immutable collection, mRequests cannot change by the time the
+            // lambda is evaluated on the handler thread so calling .get() from a binder thread
+            // is acceptable. Use handleReleaseNetworkRequest and not directly
+            // handleRemoveNetworkRequest so as to force a lookup in the requests map, in case
+            // the app already unregistered the request.
+            mHandler.post(() -> handleReleaseNetworkRequest(mRequests.get(0),
+                    mUid, false /* callOnUnavailable */));
         }
 
         @Override

tests/unit/java/com/android/server/ConnectivityServiceTest.java

@@ -280,6 +280,7 @@ import android.os.HandlerThread;
 import android.os.IBinder;
 import android.os.INetworkManagementService;
 import android.os.Looper;
+import android.os.Messenger;
 import android.os.Parcel;
 import android.os.ParcelFileDescriptor;
 import android.os.Parcelable;
@@ -2168,6 +2169,45 @@ public class ConnectivityServiceTest {
         mCm.unregisterNetworkCallback(fgMobileListenCallback);
     }
 
+    @Test
+    public void testBinderDeathAfterUnregister() throws Exception {
+        final NetworkCapabilities caps = new NetworkCapabilities.Builder()
+                .addTransportType(TRANSPORT_WIFI)
+                .build();
+        final Handler handler = new Handler(ConnectivityThread.getInstanceLooper());
+        final Messenger messenger = new Messenger(handler);
+        final CompletableFuture<Binder.DeathRecipient> deathRecipient = new CompletableFuture<>();
+        final Binder binder = new Binder() {
+            private DeathRecipient mDeathRecipient;
+            @Override
+            public void linkToDeath(@NonNull final DeathRecipient recipient, final int flags) {
+                synchronized (this) {
+                    mDeathRecipient = recipient;
+                }
+                super.linkToDeath(recipient, flags);
+                deathRecipient.complete(recipient);
+            }
+
+            @Override
+            public boolean unlinkToDeath(@NonNull final DeathRecipient recipient, final int flags) {
+                synchronized (this) {
+                    if (null == mDeathRecipient) {
+                        throw new IllegalStateException();
+                    }
+                    mDeathRecipient = null;
+                }
+                return super.unlinkToDeath(recipient, flags);
+            }
+        };
+        final NetworkRequest request = mService.listenForNetwork(caps, messenger, binder,
+                NetworkCallback.FLAG_NONE, mContext.getOpPackageName(),
+                mContext.getAttributionTag());
+        mService.releaseNetworkRequest(request);
+        deathRecipient.get().binderDied();
+        // Wait for the release message to be processed.
+        waitForIdle();
+    }
+
     @Test
     public void testValidatedCellularOutscoresUnvalidatedWiFi() throws Exception {
         // Test bringing up unvalidated WiFi