test: fix use-after-free in fake upstream

test/integration/fake_upstream.cc

@@ -626,6 +626,30 @@ testing::AssertionResult FakeUpstream::rawWriteConnection(uint32_t index, const
       timeout);
 }
 
+FakeRawConnection::~FakeRawConnection() {
+  // If the filter was already deleted, it means the shared_connection_ was too, so don't try to
+  // access it.
+  if (auto filter = read_filter_.lock(); filter != nullptr) {
+    EXPECT_TRUE(shared_connection_.executeOnDispatcher(
+        [filter = std::move(filter)](Network::Connection& connection) {
+          connection.removeReadFilter(filter);
+        }));
+  }
+}
+
+testing::AssertionResult FakeRawConnection::initialize() {
+  auto filter = Network::ReadFilterSharedPtr{new ReadFilter(*this)};
+  read_filter_ = filter;
+  testing::AssertionResult result = shared_connection_.executeOnDispatcher(
+      [filter = std::move(filter)](Network::Connection& connection) {
+        connection.addReadFilter(filter);
+      });
+  if (!result) {
+    return result;
+  }
+  return FakeConnectionBase::initialize();
+}
+
 AssertionResult FakeRawConnection::waitForData(uint64_t num_bytes, std::string* data,
                                                milliseconds timeout) {
   absl::MutexLock lock(&lock_);

test/integration/fake_upstream.h

@@ -471,6 +471,7 @@ class FakeRawConnection : public FakeConnectionBase {
   FakeRawConnection(SharedConnectionWrapper& shared_connection, Event::TestTimeSystem& time_system)
       : FakeConnectionBase(shared_connection, time_system) {}
   using ValidatorFunction = const std::function<bool(const std::string&)>;
+  ~FakeRawConnection() override;
 
   // Writes to data. If data is nullptr, discards the received data.
   ABSL_MUST_USE_RESULT
@@ -493,16 +494,7 @@ class FakeRawConnection : public FakeConnectionBase {
                                  std::chrono::milliseconds timeout = TestUtility::DefaultTimeout);
 
   ABSL_MUST_USE_RESULT
-  testing::AssertionResult initialize() override {
-    testing::AssertionResult result =
-        shared_connection_.executeOnDispatcher([this](Network::Connection& connection) {
-          connection.addReadFilter(Network::ReadFilterSharedPtr{new ReadFilter(*this)});
-        });
-    if (!result) {
-      return result;
-    }
-    return FakeConnectionBase::initialize();
-  }
+  testing::AssertionResult initialize() override;
 
   // Creates a ValidatorFunction which returns true when data_to_wait_for is
   // contained in the incoming data string. Unlike many of Envoy waitFor functions,
@@ -530,6 +522,7 @@ class FakeRawConnection : public FakeConnectionBase {
   };
 
   std::string data_ ABSL_GUARDED_BY(lock_);
+  std::weak_ptr<Network::ReadFilter> read_filter_;
 };
 
 using FakeRawConnectionPtr = std::unique_ptr<FakeRawConnection>;