From ebecb74997d7acdeeb3a808e8abc8ec37ced5444 Mon Sep 17 00:00:00 2001
From: Sangbaek Park <sangbaekpark@google.com>
Date: Mon, 01 Jun 2026 17:29:46 -0700
Subject: [PATCH] media: Fix uninitialized GPU VRAM leak in MFVEA NV12 copy paths

When the Windows Media Foundation Video Encode Accelerator (MFVEA)
performs a zero-copy GPU encode, it may allocate intermediate D3D11
textures to copy NV12 video frames. Previously, these textures were
allocated using the `coded_size` of the video frame, but only the
`visible_rect` portion was copied over via `CopySubresourceRegion`.
This left the padding region between the visible rect and the coded
size uninitialized, potentially leaking stale GPU memory to the
compressed video stream.

This CL updates the D3D11 texture allocation logic in the copy paths
(`CreateSampleFromTexture`, `GenerateResourceOnSyncTokenReleased`,
and `PerformD3DCopy`) to allocate the intermediate textures using the
exact dimensions of the `visible_rect`. This ensures that the texture
is completely filled by `CopySubresourceRegion`, eliminating any
uninitialized padding and preventing cross-origin information
disclosure.

The newly added unit test (repro case) fails without this fix.

Tests added: {
MFHelpersTest.CreateSampleFromTextureDoesNotLeakUninitializedMemory }

Bug: 517993381
Change-Id: Ifffcc8df7fb735ebd96c030fa46f75831298c12b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7886163
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Sangbaek Park <sangbaekpark@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1639808}
---

diff --git a/media/base/BUILD.gn b/media/base/BUILD.gn
index edcb8cc..82ef507 100644
--- a/media/base/BUILD.gn
+++ b/media/base/BUILD.gn
@@ -718,6 +718,7 @@
     sources += [
       "win/dxgi_device_scope_handle_unittest.cc",
       "win/media_foundation_package_locator_unittest.cc",
+      "win/mf_helpers_unittest.cc",
     ]
     deps += [
       "//media",
diff --git a/media/base/win/mf_helpers.cc b/media/base/win/mf_helpers.cc
index be0929e..2911c218 100644
--- a/media/base/win/mf_helpers.cc
+++ b/media/base/win/mf_helpers.cc
@@ -895,6 +895,8 @@
   if (need_perform_copy) {
     D3D11_TEXTURE2D_DESC desc;
     input_texture->GetDesc(&desc);
+    desc.Width = static_cast<UINT>(frame->visible_rect().width());
+    desc.Height = static_cast<UINT>(frame->visible_rect().height());
     desc.Usage = D3D11_USAGE_DEFAULT;
     desc.BindFlags = D3D11_BIND_VIDEO_ENCODER;
     desc.ArraySize = 1;
@@ -1163,6 +1165,8 @@
     texture_desc.CPUAccessFlags = 0;
     texture_desc.MiscFlags = D3D11_RESOURCE_MISC_SHARED_NTHANDLE |
                              D3D11_RESOURCE_MISC_SHARED_KEYEDMUTEX;
+    texture_desc.Width = static_cast<UINT>(frame->visible_rect().width());
+    texture_desc.Height = static_cast<UINT>(frame->visible_rect().height());
     Microsoft::WRL::ComPtr<ID3D11Texture2D> shared_texture;
     hr = shared_d3d11_device->CreateTexture2D(&texture_desc, nullptr,
                                               &shared_texture);
diff --git a/media/base/win/mf_helpers_unittest.cc b/media/base/win/mf_helpers_unittest.cc
new file mode 100644
index 0000000..d39e2bc5
--- /dev/null
+++ b/media/base/win/mf_helpers_unittest.cc
@@ -0,0 +1,84 @@
+// Copyright 2026 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/base/win/mf_helpers.h"
+
+#include <d3d11.h>
+#include <mfapi.h>
+#include <wrl/client.h>
+
+#include "base/memory/scoped_refptr.h"
+#include "media/base/video_frame.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+namespace {
+
+TEST(MFHelpersTest, CreateSampleFromTextureDoesNotLeakUninitializedMemory) {
+  Microsoft::WRL::ComPtr<ID3D11Device> device;
+  Microsoft::WRL::ComPtr<ID3D11DeviceContext> context;
+  HRESULT hr =
+      D3D11CreateDevice(nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, 0, nullptr,
+                        0, D3D11_SDK_VERSION, &device, nullptr, &context);
+  if (FAILED(hr)) {
+    // Fallback to WARP if hardware is not available.
+    hr = D3D11CreateDevice(nullptr, D3D_DRIVER_TYPE_WARP, nullptr, 0, nullptr,
+                           0, D3D11_SDK_VERSION, &device, nullptr, &context);
+    if (FAILED(hr)) {
+      GTEST_SKIP() << "D3D11 device creation failed";
+    }
+  }
+
+  // Create a texture with a larger coded size than the visible size.
+  D3D11_TEXTURE2D_DESC desc = {};
+  desc.Width = 1920;
+  desc.Height = 1088;
+  desc.MipLevels = 1;
+  desc.ArraySize = 1;
+  desc.Format = DXGI_FORMAT_NV12;
+  desc.SampleDesc.Count = 1;
+  desc.Usage = D3D11_USAGE_DEFAULT;
+  desc.BindFlags = D3D11_BIND_SHADER_RESOURCE | D3D11_BIND_RENDER_TARGET;
+
+  Microsoft::WRL::ComPtr<ID3D11Texture2D> input_texture;
+  hr = device->CreateTexture2D(&desc, nullptr, &input_texture);
+  ASSERT_TRUE(SUCCEEDED(hr));
+
+  // Create a video frame with a smaller visible rect.
+  gfx::Size coded_size(1920, 1088);
+  gfx::Rect visible_rect(0, 0, 1920, 1080);
+  gfx::Size natural_size(1920, 1080);
+  scoped_refptr<VideoFrame> frame =
+      VideoFrame::CreateFrame(PIXEL_FORMAT_NV12, coded_size, visible_rect,
+                              natural_size, base::TimeDelta());
+
+  // Create the sample and perform the copy.
+  Microsoft::WRL::ComPtr<IMFSample> sample = CreateSampleFromTexture(
+      device, frame, input_texture, /*need_perform_copy=*/true);
+  ASSERT_TRUE(sample);
+
+  // Get the texture from the sample.
+  Microsoft::WRL::ComPtr<IMFMediaBuffer> buffer;
+  hr = sample->GetBufferByIndex(0, &buffer);
+  ASSERT_TRUE(SUCCEEDED(hr));
+
+  Microsoft::WRL::ComPtr<IMFDXGIBuffer> dxgi_buffer;
+  hr = buffer.As(&dxgi_buffer);
+  ASSERT_TRUE(SUCCEEDED(hr));
+
+  Microsoft::WRL::ComPtr<ID3D11Texture2D> output_texture;
+  hr = dxgi_buffer->GetResource(IID_PPV_ARGS(&output_texture));
+  ASSERT_TRUE(SUCCEEDED(hr));
+
+  D3D11_TEXTURE2D_DESC output_desc;
+  output_texture->GetDesc(&output_desc);
+
+  // The copied texture should exactly match the visible rect, not the coded
+  // size. This ensures no uninitialized padding is left.
+  EXPECT_EQ(output_desc.Width, static_cast<UINT>(visible_rect.width()));
+  EXPECT_EQ(output_desc.Height, static_cast<UINT>(visible_rect.height()));
+}
+
+}  // namespace
+}  // namespace media
diff --git a/media/gpu/windows/media_foundation_video_encode_accelerator_win.cc b/media/gpu/windows/media_foundation_video_encode_accelerator_win.cc
index 81eed05..1549ada 100644
--- a/media/gpu/windows/media_foundation_video_encode_accelerator_win.cc
+++ b/media/gpu/windows/media_foundation_video_encode_accelerator_win.cc
@@ -2974,23 +2974,21 @@
 HRESULT MediaFoundationVideoEncodeAccelerator::InitializeD3DCopying(
     ID3D11Texture2D* input_texture) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  D3D11_TEXTURE2D_DESC input_desc = {};
-  input_texture->GetDesc(&input_desc);
   // Return early if `copied_d3d11_texture_` is already the correct size,
   // avoiding the overhead of creating a new destination texture.
   if (copied_d3d11_texture_) {
     D3D11_TEXTURE2D_DESC copy_desc = {};
     copied_d3d11_texture_->GetDesc(&copy_desc);
-    if (input_desc.Width == copy_desc.Width &&
-        input_desc.Height == copy_desc.Height) {
+    if (static_cast<UINT>(input_visible_size_.width()) == copy_desc.Width &&
+        static_cast<UINT>(input_visible_size_.height()) == copy_desc.Height) {
       return S_OK;
     }
   }
   ComD3D11Device texture_device;
   input_texture->GetDevice(&texture_device);
   D3D11_TEXTURE2D_DESC copy_desc = {
-      .Width = input_desc.Width,
-      .Height = input_desc.Height,
+      .Width = static_cast<UINT>(input_visible_size_.width()),
+      .Height = static_cast<UINT>(input_visible_size_.height()),
       .MipLevels = 1,
       .ArraySize = 1,
       .Format = DXGI_FORMAT_NV12,

diff --git a/media/base/win/mf_helpers_unittest.cc b/media/base/win/mf_helpers_unittest.cc
new file mode 100644
index 0000000..d39e2bc5
--- /dev/null
+++ b/media/base/win/mf_helpers_unittest.cc
@@ -0,0 +1,84 @@
+// Copyright 2026 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/base/win/mf_helpers.h"
+
+#include <d3d11.h>
+#include <mfapi.h>
+#include <wrl/client.h>
+
+#include "base/memory/scoped_refptr.h"
+#include "media/base/video_frame.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+namespace {
+
+TEST(MFHelpersTest, CreateSampleFromTextureDoesNotLeakUninitializedMemory) {
+  Microsoft::WRL::ComPtr<ID3D11Device> device;
+  Microsoft::WRL::ComPtr<ID3D11DeviceContext> context;
+  HRESULT hr =
+      D3D11CreateDevice(nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, 0, nullptr,
+                        0, D3D11_SDK_VERSION, &device, nullptr, &context);
+  if (FAILED(hr)) {
+    // Fallback to WARP if hardware is not available.
+    hr = D3D11CreateDevice(nullptr, D3D_DRIVER_TYPE_WARP, nullptr, 0, nullptr,
+                           0, D3D11_SDK_VERSION, &device, nullptr, &context);
+    if (FAILED(hr)) {
+      GTEST_SKIP() << "D3D11 device creation failed";
+    }
+  }
+
+  // Create a texture with a larger coded size than the visible size.
+  D3D11_TEXTURE2D_DESC desc = {};
+  desc.Width = 1920;
+  desc.Height = 1088;
+  desc.MipLevels = 1;
+  desc.ArraySize = 1;
+  desc.Format = DXGI_FORMAT_NV12;
+  desc.SampleDesc.Count = 1;
+  desc.Usage = D3D11_USAGE_DEFAULT;
+  desc.BindFlags = D3D11_BIND_SHADER_RESOURCE | D3D11_BIND_RENDER_TARGET;
+
+  Microsoft::WRL::ComPtr<ID3D11Texture2D> input_texture;
+  hr = device->CreateTexture2D(&desc, nullptr, &input_texture);
+  ASSERT_TRUE(SUCCEEDED(hr));
+
+  // Create a video frame with a smaller visible rect.
+  gfx::Size coded_size(1920, 1088);
+  gfx::Rect visible_rect(0, 0, 1920, 1080);
+  gfx::Size natural_size(1920, 1080);
+  scoped_refptr<VideoFrame> frame =
+      VideoFrame::CreateFrame(PIXEL_FORMAT_NV12, coded_size, visible_rect,
+                              natural_size, base::TimeDelta());
+
+  // Create the sample and perform the copy.
+  Microsoft::WRL::ComPtr<IMFSample> sample = CreateSampleFromTexture(
+      device, frame, input_texture, /*need_perform_copy=*/true);
+  ASSERT_TRUE(sample);
+
+  // Get the texture from the sample.
+  Microsoft::WRL::ComPtr<IMFMediaBuffer> buffer;
+  hr = sample->GetBufferByIndex(0, &buffer);
+  ASSERT_TRUE(SUCCEEDED(hr));
+
+  Microsoft::WRL::ComPtr<IMFDXGIBuffer> dxgi_buffer;
+  hr = buffer.As(&dxgi_buffer);
+  ASSERT_TRUE(SUCCEEDED(hr));
+
+  Microsoft::WRL::ComPtr<ID3D11Texture2D> output_texture;
+  hr = dxgi_buffer->GetResource(IID_PPV_ARGS(&output_texture));
+  ASSERT_TRUE(SUCCEEDED(hr));
+
+  D3D11_TEXTURE2D_DESC output_desc;
+  output_texture->GetDesc(&output_desc);
+
+  // The copied texture should exactly match the visible rect, not the coded
+  // size. This ensures no uninitialized padding is left.
+  EXPECT_EQ(output_desc.Width, static_cast<UINT>(visible_rect.width()));
+  EXPECT_EQ(output_desc.Height, static_cast<UINT>(visible_rect.height()));
+}
+
+}  // namespace
+}  // namespace media