From 6eb456bc4e6bcdf2f9f9b41c4b8265b9bee3af54 Mon Sep 17 00:00:00 2001
From: Alex Hunt <huntie@meta.com>
Date: Tue, 16 Sep 2025 03:03:06 -0700
Subject: [PATCH] Fix data race condition in NetworkHandler (#53788)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/53788

Fix thread safety issue due to member variable  in `NetworkHandler` singleton without mutex.

Also intend to un-singleton this class in the imminent future.

Changelog: [Internal]

Reviewed By: hoxyq

Differential Revision: D82460574

fbshipit-source-id: c0c614f8f1bb5ffba22872ae5717fbd2ca01f2e9
---
 .../network/NetworkHandler.cpp                | 38 +++++++++++--------
 .../network/NetworkHandler.h                  |  5 ++-
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.cpp b/packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.cpp
index 80ed5bb23b1..5e7c1b558a2 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.cpp
+++ b/packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.cpp
@@ -56,7 +56,7 @@ bool NetworkHandler::disable() {
   }
 
   enabled_.store(false, std::memory_order_release);
-  requestBodyBuffer_.clear();
+  responseBodyBuffer_.clear();
   return true;
 }
 
@@ -113,7 +113,10 @@ void NetworkHandler::onResponseReceived(
   }
 
   auto resourceType = cdp::network::resourceTypeFromMimeType(response.mimeType);
-  resourceTypeMap_.emplace(requestId, resourceType);
+  {
+    std::lock_guard<std::mutex> lock(resourceTypeMapMutex_);
+    resourceTypeMap_.emplace(requestId, resourceType);
+  }
 
   auto params = cdp::network::ResponseReceivedParams{
       .requestId = requestId,
@@ -166,23 +169,26 @@ void NetworkHandler::onLoadingFinished(
 
 void NetworkHandler::onLoadingFailed(
     const std::string& requestId,
-    bool cancelled) const {
+    bool cancelled) {
   if (!isEnabledNoSync()) {
     return;
   }
 
-  auto params = cdp::network::LoadingFailedParams{
-      .requestId = requestId,
-      .timestamp = getCurrentUnixTimestampSeconds(),
-      .type = resourceTypeMap_.find(requestId) != resourceTypeMap_.end()
-          ? resourceTypeMap_.at(requestId)
-          : "Other",
-      .errorText = cancelled ? "net::ERR_ABORTED" : "net::ERR_FAILED",
-      .canceled = cancelled,
-  };
+  {
+    std::lock_guard<std::mutex> lock(resourceTypeMapMutex_);
+    auto params = cdp::network::LoadingFailedParams{
+        .requestId = requestId,
+        .timestamp = getCurrentUnixTimestampSeconds(),
+        .type = resourceTypeMap_.find(requestId) != resourceTypeMap_.end()
+            ? resourceTypeMap_.at(requestId)
+            : "Other",
+        .errorText = cancelled ? "net::ERR_ABORTED" : "net::ERR_FAILED",
+        .canceled = cancelled,
+    };
 
-  frontendChannel_(
-      cdp::jsonNotification("Network.loadingFailed", params.toDynamic()));
+    frontendChannel_(
+        cdp::jsonNotification("Network.loadingFailed", params.toDynamic()));
+  }
 }
 
 void NetworkHandler::storeResponseBody(
@@ -190,13 +196,13 @@ void NetworkHandler::storeResponseBody(
     std::string_view body,
     bool base64Encoded) {
   std::lock_guard<std::mutex> lock(requestBodyMutex_);
-  requestBodyBuffer_.put(requestId, body, base64Encoded);
+  responseBodyBuffer_.put(requestId, body, base64Encoded);
 }
 
 std::optional<std::tuple<std::string, bool>> NetworkHandler::getResponseBody(
     const std::string& requestId) {
   std::lock_guard<std::mutex> lock(requestBodyMutex_);
-  auto responseBody = requestBodyBuffer_.get(requestId);
+  auto responseBody = responseBodyBuffer_.get(requestId);
 
   if (responseBody == nullptr) {
     return std::nullopt;
diff --git a/packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.h b/packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.h
index cb38d1b7628..b3c51b83ce4 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.h
+++ b/packages/react-native/ReactCommon/jsinspector-modern/network/NetworkHandler.h
@@ -100,7 +100,7 @@ class NetworkHandler {
   /**
    * @cdp Network.loadingFailed
    */
-  void onLoadingFailed(const std::string& requestId, bool cancelled) const;
+  void onLoadingFailed(const std::string& requestId, bool cancelled);
 
   /**
    * Store the fetched response body for a text or image network response.
@@ -139,8 +139,9 @@ class NetworkHandler {
   FrontendChannel frontendChannel_;
 
   std::map<std::string, std::string> resourceTypeMap_{};
+  std::mutex resourceTypeMapMutex_{};
 
-  BoundedRequestBuffer requestBodyBuffer_{};
+  BoundedRequestBuffer responseBodyBuffer_{};
   std::mutex requestBodyMutex_;
 };