From e966e132e680ad2593aaddac191ec74120918ea5 Mon Sep 17 00:00:00 2001
From: Samuel Susla <samuelsusla@meta.com>
Date: Mon, 16 Sep 2024 04:35:15 -0700
Subject: [PATCH] fix race condition in IntentModule.mInitialURLListener
 (#46499)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/46499

changelog: [internal]

IntentModule.mInitialURLListener is accessed and mutated on three different threads and is missing synchronisation.

1. In [waitForActivityAndGetInitialURL](https://github.com/facebook/react-native/blob/main/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/intent/IntentModule.java#L83) it is accessed and mutated from thread mqt_v_native.
2.  In [LifecycleEventListener](https://github.com/facebook/react-native/blob/main/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/intent/IntentModule.java#L97) it is mutated from the main thread.

3. In [invalidate](https://github.com/facebook/react-native/blob/main/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/intent/IntentModule.java#L44) it is read and mutated on a another thread.

Reviewed By: javache

Differential Revision: D62698183
---
 .../react/modules/intent/IntentModule.java         | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/intent/IntentModule.java b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/intent/IntentModule.java
index f3efa6cd0fc3..1e285b2c6f17 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/intent/IntentModule.java
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/intent/IntentModule.java
@@ -39,9 +39,11 @@ public IntentModule(ReactApplicationContext reactContext) {
 
   @Override
   public void invalidate() {
-    if (mInitialURLListener != null) {
-      getReactApplicationContext().removeLifecycleEventListener(mInitialURLListener);
-      mInitialURLListener = null;
+    synchronized (this) {
+      if (mInitialURLListener != null) {
+        getReactApplicationContext().removeLifecycleEventListener(mInitialURLListener);
+        mInitialURLListener = null;
+      }
     }
     super.invalidate();
   }
@@ -79,7 +81,7 @@ public void getInitialURL(Promise promise) {
     }
   }
 
-  private void waitForActivityAndGetInitialURL(final Promise promise) {
+  private synchronized void waitForActivityAndGetInitialURL(final Promise promise) {
     if (mInitialURLListener != null) {
       promise.reject(
           new IllegalStateException(
@@ -94,7 +96,9 @@ public void onHostResume() {
             getInitialURL(promise);
 
             getReactApplicationContext().removeLifecycleEventListener(this);
-            mInitialURLListener = null;
+            synchronized (IntentModule.this) {
+              mInitialURLListener = null;
+            }
           }
 
           @Override