From 29268f92bbf3b2a2c5566bab2eb4d16b0e5bee49 Mon Sep 17 00:00:00 2001
From: Guido Urdaneta <[email protected]>
Date: Thu, 22 Oct 2026 03:56:15 -0700
Subject: [PATCH] [MediaStream] Fix UAF in MediaStream(Audio|Video)Track::StopAndNotify

Stopping a track stops the corresponding source if the track was the
last one connected to the source. Stopping the source synchronously
dispatches the `ended` event on other MediaStreamTrackImpls sharing
that source, which runs script and can trigger an Oilpan GC.
If nothing else references the MediaStreamComponentImpl owning
the platform track, the compoenent's pre-finalizer
(MediaStreamComponentImpl::Dispose) deletes the platform track while
StopAndNotify() is still on the stack.

In that case, the platform track destructor has already called Stop()
(ending sinks and invalidating weak pointers), so check a `WeakPtr`
acquired before stopping the track and return early if the platform
track has been deleted.

Bug: 576215540
Change-Id: I06e79a8afc1f5b23b2b903ca364b27c6c689ce0e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8626348
Commit-Queue: Guido Urdaneta <[email protected]>
Reviewed-by: Henrik Boström <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1724620}
---
diff --git a/third_party/blink/renderer/modules/mediastream/media_stream_video_track.cc b/third_party/blink/renderer/modules/mediastream/media_stream_video_track.cc
index 235dbf3c..53f11849 100644
--- a/third_party/blink/renderer/modules/mediastream/media_stream_video_track.cc
+++ b/third_party/blink/renderer/modules/mediastream/media_stream_video_track.cc
@@ -1113,8 +1113,25 @@
   TRACE_EVENT("media", "MediaStreamVideoTrack::StopAndNotify");
   DCHECK_CALLED_ON_VALID_THREAD(main_render_thread_checker_);
   if (source_) {
-    source_->RemoveTrack(this, std::move(callback));
-    source_ = nullptr;
+    // MediaStreamVideoSource::RemoveTrack() stops the source if this was its
+    // last track. That synchronously fires 'ended' on other
+    // MediaStreamTrackImpls sharing the source, which runs script, which can
+    // trigger a GC. If nothing else references the MediaStreamComponentImpl
+    // owning |this|, its pre-finalizer deletes |this| while this frame is still
+    // on the stack. See https://crbug.com/576215540.
+    //
+    // Clear |source_| before calling RemoveTrack() so that the re-entrant
+    // Stop() call from ~MediaStreamVideoTrack() does not try to remove |this|
+    // from the source a second time. The destructor's Stop() call takes care
+    // of ending the sinks and stopping |refresh_timer_|, and |callback| is
+    // owned by the source once RemoveTrack() has been called, so there is
+    // nothing left to do here if |this| is gone.
+    base::WeakPtr<MediaStreamVideoTrack> weak_this = weak_factory_.GetWeakPtr();
+    MediaStreamVideoSource* source = std::exchange(source_, nullptr).get();
+    source->RemoveTrack(this, std::move(callback));
+    if (!weak_this) {
+      return;
+    }
   } else if (callback) {
     std::move(callback).Run();
   }
diff --git a/third_party/blink/renderer/modules/mediastream/media_stream_video_track.h b/third_party/blink/renderer/modules/mediastream/media_stream_video_track.h
index 40f92b9..e7f553b 100644
--- a/third_party/blink/renderer/modules/mediastream/media_stream_video_track.h
+++ b/third_party/blink/renderer/modules/mediastream/media_stream_video_track.h
@@ -199,6 +199,10 @@
     is_screencast_ = is_screencast;
   }
 
+  base::WeakPtr<MediaStreamVideoTrack> GetWeakPtrForTesting() {
+    return weak_factory_.GetWeakPtr();
+  }
+
   MediaStreamTrackPlatform::StreamType Type() const override {
     return MediaStreamTrackPlatform::StreamType::kVideo;
   }
diff --git a/third_party/blink/renderer/platform/mediastream/media_stream_audio_track.cc b/third_party/blink/renderer/platform/mediastream/media_stream_audio_track.cc
index ac47c0dd..0626c0c 100644
--- a/third_party/blink/renderer/platform/mediastream/media_stream_audio_track.cc
+++ b/third_party/blink/renderer/platform/mediastream/media_stream_audio_track.cc
@@ -144,8 +144,26 @@
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   WebRtcLog(kTag, this, "%s()", __func__);
 
-  if (!stop_callback_.is_null())
+  // Running |stop_callback_| (MediaStreamAudioSource::StopAudioDeliveryTo)
+  // stops the source if this was its last track. That synchronously fires
+  // 'ended' on other MediaStreamTrackImpls sharing the source, which runs
+  // script, which can trigger a GC. If nothing else references the
+  // MediaStreamComponentImpl owning |this|, its pre-finalizer deletes |this|
+  // while this frame is still on the stack. In that case
+  // ~MediaStreamAudioTrack() has already run Stop() (ending the sinks and
+  // invalidating weak pointers), so the only thing left to do is run
+  // |callback|, which UserMediaClient's request queue relies on to make
+  // progress. See https://crbug.com/576215540.
+  base::WeakPtr<MediaStreamAudioTrack> weak_this = GetWeakPtr();
+  if (!stop_callback_.is_null()) {
     std::move(stop_callback_).Run();
+  }
+  if (!weak_this) {
+    if (callback) {
+      std::move(callback).Run();
+    }
+    return;
+  }
 
   Vector<WebMediaStreamAudioSink*> sinks_to_end;
   deliverer_.GetConsumerList(&sinks_to_end);
@@ -154,8 +172,9 @@
     sink->OnReadyStateChanged(WebMediaStreamSource::kReadyStateEnded);
   }
 
-  if (callback)
+  if (callback) {
     std::move(callback).Run();
+  }
   weak_factory_.InvalidateWeakPtrs();
 }
 
diff --git a/third_party/blink/renderer/modules/mediastream/media_stream_track_impl_test.cc b/third_party/blink/renderer/modules/mediastream/media_stream_track_impl_test.cc
index fec1479a..4460fea 100644
--- a/third_party/blink/renderer/modules/mediastream/media_stream_track_impl_test.cc
+++ b/third_party/blink/renderer/modules/mediastream/media_stream_track_impl_test.cc
@@ -24,6 +24,7 @@
 #include "third_party/blink/renderer/bindings/modules/v8/v8_media_stream_track_state.h"
 #include "third_party/blink/renderer/bindings/modules/v8/v8_media_track_constraints.h"
 #include "third_party/blink/renderer/bindings/modules/v8/v8_union_constrainlongrange_long.h"
+#include "third_party/blink/renderer/core/dom/events/event.h"
 #include "third_party/blink/renderer/core/dom/events/native_event_listener.h"
 #include "third_party/blink/renderer/core/frame/frame_test_helpers.h"
 #include "third_party/blink/renderer/core/html/media/html_media_element.h"
@@ -957,4 +958,107 @@
   // The test passes if it doesn't crash.
 }
 
+TEST_F(MediaStreamTrackImplTest, StopAudioTrackWhenEndedEventTriggersGC) {
+  V8TestingScope v8_scope;
+
+  Persistent<MediaStreamComponent> component = MakeMockAudioComponent();
+  MediaStreamAudioSource* source =
+      MediaStreamAudioSource::From(component->Source());
+  MediaStreamAudioTrack* platform_track =
+      MediaStreamAudioTrack::From(component.Get());
+  ASSERT_TRUE(source);
+  ASSERT_TRUE(platform_track);
+  EXPECT_TRUE(source->ConnectToInitializedTrack(component.Get()));
+
+  MediaStreamComponent* other_component =
+      MakeGarbageCollected<MediaStreamComponentImpl>(
+          component->Source(),
+          std::make_unique<MediaStreamAudioTrack>(/*is_local_track=*/true));
+  Persistent<MediaStreamTrackImpl> other_track =
+      MakeGarbageCollected<MediaStreamTrackImpl>(v8_scope.GetExecutionContext(),
+                                                 other_component);
+
+  Persistent<testing::StrictMock<MockEventListener>> event_listener =
+      MakeGarbageCollected<testing::StrictMock<MockEventListener>>();
+  other_track->addEventListener(event_type_names::kEnded, event_listener.Get());
+
+  base::WeakPtr<MediaStreamAudioTrack> weak_platform_track =
+      platform_track->GetWeakPtr();
+  // Precise GC (WebHeap::CollectAllGarbageForTesting) does not scan the C++
+  // stack and would otherwise collect the in-flight Event, which
+  // EventDispatcher holds only on the stack.
+  Persistent<Event> keep_event_alive;
+  EXPECT_CALL(*event_listener, Invoke(_, _))
+      .WillOnce([&](ExecutionContext*, Event* event) {
+        keep_event_alive = event;
+        component.Clear();
+        WebHeap::CollectAllGarbageForTesting();
+        EXPECT_FALSE(weak_platform_track);
+      });
+
+  bool callback_called = false;
+  platform_track->StopAndNotify(
+      blink::BindOnce([](bool* called) { *called = true; },
+                      base::Unretained(&callback_called)));
+  EXPECT_TRUE(callback_called);
+  EXPECT_FALSE(weak_platform_track);
+}
+
+TEST_F(MediaStreamTrackImplTest, StopVideoTrackWhenEndedEventTriggersGC) {
+  V8TestingScope v8_scope;
+
+  Persistent<MediaStreamComponent> component = MakeMockVideoComponent();
+  MediaStreamVideoSource* source =
+      MediaStreamVideoSource::GetVideoSource(component->Source());
+  MediaStreamVideoTrack* platform_track =
+      MediaStreamVideoTrack::From(component.Get());
+  ASSERT_TRUE(source);
+  ASSERT_TRUE(platform_track);
+
+  // A second track on the same source, with an 'ended' listener. Its platform
+  // track is stopped right away so that |platform_track| is the source's last
+  // track and stopping it stops the source.
+  MediaStreamComponent* other_component =
+      MakeGarbageCollected<MediaStreamComponentImpl>(
+          component->Source(),
+          std::make_unique<MediaStreamVideoTrack>(
+              source, MediaStreamVideoSource::ConstraintsOnceCallback(),
+              /*enabled=*/true));
+  MediaStreamVideoTrack::From(other_component)->Stop();
+  Persistent<MediaStreamTrackImpl> other_track =
+      MakeGarbageCollected<MediaStreamTrackImpl>(v8_scope.GetExecutionContext(),
+                                                 other_component);
+
+  Persistent<testing::StrictMock<MockEventListener>> event_listener =
+      MakeGarbageCollected<testing::StrictMock<MockEventListener>>();
+  other_track->addEventListener(event_type_names::kEnded, event_listener.Get());
+
+  base::WeakPtr<MediaStreamVideoTrack> weak_platform_track =
+      platform_track->GetWeakPtrForTesting();
+  // Precise GC (WebHeap::CollectAllGarbageForTesting) does not scan the C++
+  // stack and would otherwise collect the in-flight Event, which
+  // EventDispatcher holds only on the stack.
+  Persistent<Event> keep_event_alive;
+  EXPECT_CALL(*event_listener, Invoke(_, _))
+      .WillOnce([&](ExecutionContext*, Event* event) {
+        keep_event_alive = event;
+        component.Clear();
+        WebHeap::CollectAllGarbageForTesting();
+        EXPECT_FALSE(weak_platform_track);
+      });
+
+  bool callback_called = false;
+  platform_track->StopAndNotify(
+      blink::BindOnce([](bool* called) { *called = true; },
+                      base::Unretained(&callback_called)));
+  EXPECT_FALSE(weak_platform_track);
+  EXPECT_EQ(MediaStreamSource::kReadyStateEnded,
+            other_component->Source()->GetReadyState());
+
+  // MediaStreamVideoSource runs the callback once the source has actually
+  // stopped, which happens on a separate task.
+  test::RunPendingTasks();
+  EXPECT_TRUE(callback_called);
+}
+
 }  // namespace blink
diff --git a/third_party/blink/renderer/modules/mediastream/media_stream_video_track_test.cc b/third_party/blink/renderer/modules/mediastream/media_stream_video_track_test.cc
index 2d5a72c..1b178807 100644
--- a/third_party/blink/renderer/modules/mediastream/media_stream_video_track_test.cc
+++ b/third_party/blink/renderer/modules/mediastream/media_stream_video_track_test.cc
@@ -15,6 +15,7 @@
 #include "base/functional/callback_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/raw_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
@@ -24,6 +25,7 @@
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/test_future.h"
 #include "base/threading/thread_checker.h"
+#include "build/build_config.h"
 #include "media/base/video_frame.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -379,6 +381,77 @@
   sink2.DisconnectFromTrack();
 }
 
+class GarbageCollectingSourceObserver final
+    : public GarbageCollected<GarbageCollectingSourceObserver>,
+      public MediaStreamSource::Observer {
+ public:
+  explicit GarbageCollectingSourceObserver(base::OnceClosure on_state_changed)
+      : on_state_changed_(std::move(on_state_changed)) {}
+
+  void SourceChangedState() override {
+    if (on_state_changed_) {
+      std::move(on_state_changed_).Run();
+    }
+  }
+  void SourceChangedCaptureConfiguration() override {}
+  void SourceChangedCaptureHandle() override {}
+#if !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_IOS)
+  void SourceChangedZoomLevel(int) override {}
+#endif
+
+  void Trace(Visitor* visitor) const override {
+    MediaStreamSource::Observer::Trace(visitor);
+  }
+
+ private:
+  base::OnceClosure on_state_changed_;
+};
+
+// Regression test for https://crbug.com/576215540: verifies that
+// MediaStreamVideoTrack::StopAndNotify() does not UAF if stopping the source
+// synchronously triggers garbage collection of the owning
+// MediaStreamComponentImpl and destroys the MediaStreamVideoTrack.
+TEST_F(MediaStreamVideoTrackTest,
+       StopAndNotifyComponentGarbageCollectedOnSourceStop) {
+  InitializeSource();
+  WebMediaStreamTrack track = CreateTrack();
+  MediaStreamVideoTrack* raw_track = MediaStreamVideoTrack::From(track);
+  ASSERT_TRUE(raw_track);
+  base::WeakPtr<MediaStreamVideoTrack> weak_track =
+      raw_track->GetWeakPtrForTesting();
+  ASSERT_TRUE(weak_track);
+  EXPECT_EQ(MediaStreamSource::kReadyStateLive,
+            stream_source()->GetReadyState());
+
+  bool observer_called = false;
+  Persistent<GarbageCollectingSourceObserver> observer =
+      MakeGarbageCollected<GarbageCollectingSourceObserver>(
+          base::BindLambdaForTesting([&]() {
+            observer_called = true;
+            // Drop the last reference to the MediaStreamComponentImpl owning
+            // |raw_track| and collect it, which destroys |raw_track| while
+            // StopAndNotify() is still on the stack.
+            track.Reset();
+            WebHeap::CollectAllGarbageForTesting();
+            EXPECT_FALSE(weak_track);
+          }));
+  stream_source()->AddObserver(observer.Get());
+
+  bool notify_callback_called = false;
+  raw_track->StopAndNotify(
+      base::BindLambdaForTesting([&]() { notify_callback_called = true; }));
+
+  EXPECT_TRUE(observer_called);
+  EXPECT_FALSE(weak_track);
+  EXPECT_EQ(MediaStreamSource::kReadyStateEnded,
+            stream_source()->GetReadyState());
+
+  // The source runs the callback once it has actually stopped, which happens
+  // on a separate task.
+  base::RunLoop().RunUntilIdle();
+  EXPECT_TRUE(notify_callback_called);
+}
+
 TEST_F(MediaStreamVideoTrackTest, CheckTrackRequestsFrame) {
   InitializeSource();
   UpdateVideoSourceToRespondToRequestRefreshFrame();
diff --git a/third_party/blink/renderer/platform/mediastream/media_stream_audio_test.cc b/third_party/blink/renderer/platform/mediastream/media_stream_audio_test.cc
index 609e99a..0a875d0 100644
--- a/third_party/blink/renderer/platform/mediastream/media_stream_audio_test.cc
+++ b/third_party/blink/renderer/platform/mediastream/media_stream_audio_test.cc
@@ -15,11 +15,13 @@
 #include "base/numerics/safe_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/test/bind.h"
 #include "base/test/task_environment.h"
 #include "base/test/test_timeouts.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
+#include "build/build_config.h"
 #include "build/buildflag.h"
 #include "media/base/audio_bus.h"
 #include "media/base/audio_glitch_info.h"
@@ -632,4 +634,72 @@
 #endif
 }
 
+namespace {
+
+class GarbageCollectingSourceObserver final
+    : public GarbageCollected<GarbageCollectingSourceObserver>,
+      public MediaStreamSource::Observer {
+ public:
+  explicit GarbageCollectingSourceObserver(base::OnceClosure on_state_changed)
+      : on_state_changed_(std::move(on_state_changed)) {}
+
+  void SourceChangedState() override {
+    if (on_state_changed_) {
+      std::move(on_state_changed_).Run();
+    }
+  }
+  void SourceChangedCaptureConfiguration() override {}
+  void SourceChangedCaptureHandle() override {}
+#if !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_IOS)
+  void SourceChangedZoomLevel(int) override {}
+#endif
+
+  void Trace(Visitor* visitor) const override {
+    MediaStreamSource::Observer::Trace(visitor);
+  }
+
+ private:
+  base::OnceClosure on_state_changed_;
+};
+
+}  // namespace
+
+// Regression test for https://crbug.com/576215540: verifies that
+// MediaStreamAudioTrack::StopAndNotify() does not UAF if stopping the source
+// synchronously triggers garbage collection of the owning
+// MediaStreamComponentImpl and destroys the MediaStreamAudioTrack.
+TEST_F(MediaStreamAudioTest,
+       StopAndNotifyComponentGarbageCollectedOnSourceStop) {
+  ASSERT_TRUE(source());
+  EXPECT_TRUE(source()->ConnectToInitializedTrack(audio_component_));
+  MediaStreamAudioTrack* raw_track = track();
+  ASSERT_TRUE(raw_track);
+  base::WeakPtr<MediaStreamAudioTrack> weak_track = raw_track->GetWeakPtr();
+  ASSERT_TRUE(weak_track);
+
+  FakeMediaStreamAudioSink sink;
... (file diff truncated)

diff --git a/third_party/blink/renderer/modules/mediastream/media_stream_track_impl_test.cc b/third_party/blink/renderer/modules/mediastream/media_stream_track_impl_test.cc
index fec1479a..4460fea 100644
--- a/third_party/blink/renderer/modules/mediastream/media_stream_track_impl_test.cc
+++ b/third_party/blink/renderer/modules/mediastream/media_stream_track_impl_test.cc
@@ -24,6 +24,7 @@
 #include "third_party/blink/renderer/bindings/modules/v8/v8_media_stream_track_state.h"
 #include "third_party/blink/renderer/bindings/modules/v8/v8_media_track_constraints.h"
 #include "third_party/blink/renderer/bindings/modules/v8/v8_union_constrainlongrange_long.h"
+#include "third_party/blink/renderer/core/dom/events/event.h"
 #include "third_party/blink/renderer/core/dom/events/native_event_listener.h"
 #include "third_party/blink/renderer/core/frame/frame_test_helpers.h"
 #include "third_party/blink/renderer/core/html/media/html_media_element.h"
@@ -957,4 +958,107 @@
   // The test passes if it doesn't crash.
 }
 
+TEST_F(MediaStreamTrackImplTest, StopAudioTrackWhenEndedEventTriggersGC) {
+  V8TestingScope v8_scope;
+
+  Persistent<MediaStreamComponent> component = MakeMockAudioComponent();
+  MediaStreamAudioSource* source =
+      MediaStreamAudioSource::From(component->Source());
+  MediaStreamAudioTrack* platform_track =
+      MediaStreamAudioTrack::From(component.Get());
+  ASSERT_TRUE(source);
+  ASSERT_TRUE(platform_track);
+  EXPECT_TRUE(source->ConnectToInitializedTrack(component.Get()));
+
+  MediaStreamComponent* other_component =
+      MakeGarbageCollected<MediaStreamComponentImpl>(
+          component->Source(),
+          std::make_unique<MediaStreamAudioTrack>(/*is_local_track=*/true));
+  Persistent<MediaStreamTrackImpl> other_track =
+      MakeGarbageCollected<MediaStreamTrackImpl>(v8_scope.GetExecutionContext(),
+                                                 other_component);
+
+  Persistent<testing::StrictMock<MockEventListener>> event_listener =
+      MakeGarbageCollected<testing::StrictMock<MockEventListener>>();
+  other_track->addEventListener(event_type_names::kEnded, event_listener.Get());
+
+  base::WeakPtr<MediaStreamAudioTrack> weak_platform_track =
+      platform_track->GetWeakPtr();
+  // Precise GC (WebHeap::CollectAllGarbageForTesting) does not scan the C++
+  // stack and would otherwise collect the in-flight Event, which
+  // EventDispatcher holds only on the stack.
+  Persistent<Event> keep_event_alive;
+  EXPECT_CALL(*event_listener, Invoke(_, _))
+      .WillOnce([&](ExecutionContext*, Event* event) {
+        keep_event_alive = event;
+        component.Clear();
+        WebHeap::CollectAllGarbageForTesting();
+        EXPECT_FALSE(weak_platform_track);
+      });
+
+  bool callback_called = false;
+  platform_track->StopAndNotify(
+      blink::BindOnce([](bool* called) { *called = true; },
+                      base::Unretained(&callback_called)));
+  EXPECT_TRUE(callback_called);
+  EXPECT_FALSE(weak_platform_track);
+}
+
+TEST_F(MediaStreamTrackImplTest, StopVideoTrackWhenEndedEventTriggersGC) {
+  V8TestingScope v8_scope;
+
+  Persistent<MediaStreamComponent> component = MakeMockVideoComponent();
+  MediaStreamVideoSource* source =
+      MediaStreamVideoSource::GetVideoSource(component->Source());
+  MediaStreamVideoTrack* platform_track =
+      MediaStreamVideoTrack::From(component.Get());
+  ASSERT_TRUE(source);
+  ASSERT_TRUE(platform_track);
+
+  // A second track on the same source, with an 'ended' listener. Its platform
+  // track is stopped right away so that |platform_track| is the source's last
+  // track and stopping it stops the source.
+  MediaStreamComponent* other_component =
+      MakeGarbageCollected<MediaStreamComponentImpl>(
+          component->Source(),
+          std::make_unique<MediaStreamVideoTrack>(
+              source, MediaStreamVideoSource::ConstraintsOnceCallback(),
+              /*enabled=*/true));
+  MediaStreamVideoTrack::From(other_component)->Stop();
+  Persistent<MediaStreamTrackImpl> other_track =
+      MakeGarbageCollected<MediaStreamTrackImpl>(v8_scope.GetExecutionContext(),
+                                                 other_component);
+
+  Persistent<testing::StrictMock<MockEventListener>> event_listener =
+      MakeGarbageCollected<testing::StrictMock<MockEventListener>>();
+  other_track->addEventListener(event_type_names::kEnded, event_listener.Get());
+
+  base::WeakPtr<MediaStreamVideoTrack> weak_platform_track =
+      platform_track->GetWeakPtrForTesting();
+  // Precise GC (WebHeap::CollectAllGarbageForTesting) does not scan the C++
+  // stack and would otherwise collect the in-flight Event, which
+  // EventDispatcher holds only on the stack.
+  Persistent<Event> keep_event_alive;
+  EXPECT_CALL(*event_listener, Invoke(_, _))
+      .WillOnce([&](ExecutionContext*, Event* event) {
+        keep_event_alive = event;
+        component.Clear();
+        WebHeap::CollectAllGarbageForTesting();
+        EXPECT_FALSE(weak_platform_track);
+      });
+
+  bool callback_called = false;
+  platform_track->StopAndNotify(
+      blink::BindOnce([](bool* called) { *called = true; },
+                      base::Unretained(&callback_called)));
+  EXPECT_FALSE(weak_platform_track);
+  EXPECT_EQ(MediaStreamSource::kReadyStateEnded,
+            other_component->Source()->GetReadyState());
+
+  // MediaStreamVideoSource runs the callback once the source has actually
+  // stopped, which happens on a separate task.
+  test::RunPendingTasks();
+  EXPECT_TRUE(callback_called);
+}
+
 }  // namespace blink
diff --git a/third_party/blink/renderer/modules/mediastream/media_stream_video_track_test.cc b/third_party/blink/renderer/modules/mediastream/media_stream_video_track_test.cc
index 2d5a72c..1b178807 100644
--- a/third_party/blink/renderer/modules/mediastream/media_stream_video_track_test.cc
+++ b/third_party/blink/renderer/modules/mediastream/media_stream_video_track_test.cc
@@ -15,6 +15,7 @@
 #include "base/functional/callback_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/raw_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
@@ -24,6 +25,7 @@
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/test_future.h"
 #include "base/threading/thread_checker.h"
+#include "build/build_config.h"
 #include "media/base/video_frame.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -379,6 +381,77 @@
   sink2.DisconnectFromTrack();
 }
 
+class GarbageCollectingSourceObserver final
+    : public GarbageCollected<GarbageCollectingSourceObserver>,
+      public MediaStreamSource::Observer {
+ public:
+  explicit GarbageCollectingSourceObserver(base::OnceClosure on_state_changed)
+      : on_state_changed_(std::move(on_state_changed)) {}
+
+  void SourceChangedState() override {
+    if (on_state_changed_) {
+      std::move(on_state_changed_).Run();
+    }
+  }
+  void SourceChangedCaptureConfiguration() override {}
+  void SourceChangedCaptureHandle() override {}
+#if !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_IOS)
+  void SourceChangedZoomLevel(int) override {}
+#endif
+
+  void Trace(Visitor* visitor) const override {
+    MediaStreamSource::Observer::Trace(visitor);
+  }
+
+ private:
+  base::OnceClosure on_state_changed_;
+};
+
+// Regression test for https://crbug.com/576215540: verifies that
+// MediaStreamVideoTrack::StopAndNotify() does not UAF if stopping the source
+// synchronously triggers garbage collection of the owning
+// MediaStreamComponentImpl and destroys the MediaStreamVideoTrack.
+TEST_F(MediaStreamVideoTrackTest,
+       StopAndNotifyComponentGarbageCollectedOnSourceStop) {
+  InitializeSource();
+  WebMediaStreamTrack track = CreateTrack();
+  MediaStreamVideoTrack* raw_track = MediaStreamVideoTrack::From(track);
+  ASSERT_TRUE(raw_track);
+  base::WeakPtr<MediaStreamVideoTrack> weak_track =
+      raw_track->GetWeakPtrForTesting();
+  ASSERT_TRUE(weak_track);
+  EXPECT_EQ(MediaStreamSource::kReadyStateLive,
+            stream_source()->GetReadyState());
+
+  bool observer_called = false;
+  Persistent<GarbageCollectingSourceObserver> observer =
+      MakeGarbageCollected<GarbageCollectingSourceObserver>(
+          base::BindLambdaForTesting([&]() {
+            observer_called = true;
+            // Drop the last reference to the MediaStreamComponentImpl owning
+            // |raw_track| and collect it, which destroys |raw_track| while
+            // StopAndNotify() is still on the stack.
+            track.Reset();
+            WebHeap::CollectAllGarbageForTesting();
+            EXPECT_FALSE(weak_track);
+          }));
+  stream_source()->AddObserver(observer.Get());
+
+  bool notify_callback_called = false;
+  raw_track->StopAndNotify(
+      base::BindLambdaForTesting([&]() { notify_callback_called = true; }));
+
+  EXPECT_TRUE(observer_called);
+  EXPECT_FALSE(weak_track);
+  EXPECT_EQ(MediaStreamSource::kReadyStateEnded,
+            stream_source()->GetReadyState());
+
+  // The source runs the callback once it has actually stopped, which happens
+  // on a separate task.
+  base::RunLoop().RunUntilIdle();
+  EXPECT_TRUE(notify_callback_called);
+}
+
 TEST_F(MediaStreamVideoTrackTest, CheckTrackRequestsFrame) {
   InitializeSource();
   UpdateVideoSourceToRespondToRequestRefreshFrame();
diff --git a/third_party/blink/renderer/platform/mediastream/media_stream_audio_test.cc b/third_party/blink/renderer/platform/mediastream/media_stream_audio_test.cc
index 609e99a..0a875d0 100644
--- a/third_party/blink/renderer/platform/mediastream/media_stream_audio_test.cc
+++ b/third_party/blink/renderer/platform/mediastream/media_stream_audio_test.cc
@@ -15,11 +15,13 @@
 #include "base/numerics/safe_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/test/bind.h"
 #include "base/test/task_environment.h"
 #include "base/test/test_timeouts.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
+#include "build/build_config.h"
 #include "build/buildflag.h"
 #include "media/base/audio_bus.h"
 #include "media/base/audio_glitch_info.h"
@@ -632,4 +634,72 @@
 #endif
 }
 
+namespace {
+
+class GarbageCollectingSourceObserver final
+    : public GarbageCollected<GarbageCollectingSourceObserver>,
+      public MediaStreamSource::Observer {
+ public:
+  explicit GarbageCollectingSourceObserver(base::OnceClosure on_state_changed)
+      : on_state_changed_(std::move(on_state_changed)) {}
+
+  void SourceChangedState() override {
+    if (on_state_changed_) {
+      std::move(on_state_changed_).Run();
+    }
+  }
+  void SourceChangedCaptureConfiguration() override {}
+  void SourceChangedCaptureHandle() override {}
+#if !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_IOS)
+  void SourceChangedZoomLevel(int) override {}
+#endif
+
+  void Trace(Visitor* visitor) const override {
+    MediaStreamSource::Observer::Trace(visitor);
+  }
+
+ private:
+  base::OnceClosure on_state_changed_;
+};
+
+}  // namespace
+
+// Regression test for https://crbug.com/576215540: verifies that
+// MediaStreamAudioTrack::StopAndNotify() does not UAF if stopping the source
+// synchronously triggers garbage collection of the owning
+// MediaStreamComponentImpl and destroys the MediaStreamAudioTrack.
+TEST_F(MediaStreamAudioTest,
+       StopAndNotifyComponentGarbageCollectedOnSourceStop) {
+  ASSERT_TRUE(source());
+  EXPECT_TRUE(source()->ConnectToInitializedTrack(audio_component_));
+  MediaStreamAudioTrack* raw_track = track();
+  ASSERT_TRUE(raw_track);
+  base::WeakPtr<MediaStreamAudioTrack> weak_track = raw_track->GetWeakPtr();
+  ASSERT_TRUE(weak_track);
+
+  FakeMediaStreamAudioSink sink;
+  raw_track->AddSink(&sink);
+  EXPECT_FALSE(sink.was_ended());
+
+  bool observer_called = false;
+  Persistent<GarbageCollectingSourceObserver> observer =
+      MakeGarbageCollected<GarbageCollectingSourceObserver>(
+          base::BindLambdaForTesting([&]() {
+            observer_called = true;
+            audio_component_ = nullptr;
+            WebHeap::CollectAllGarbageForTesting();
+            EXPECT_FALSE(weak_track);
+          }));
+  audio_source_->AddObserver(observer.Get());
+
+  bool notify_callback_called = false;
+  raw_track->StopAndNotify(
... (truncated)