Fix potential UAF of CefBPDNativeAura::window_widget_

libcef/browser/native/browser_platform_delegate_native_aura.cc

@@ -216,6 +216,12 @@ gfx::Vector2d CefBrowserPlatformDelegateNativeAura::GetUiWheelEventOffset(
   return gfx::Vector2d(deltaX, deltaY);
 }
 
+base::OnceClosure
+CefBrowserPlatformDelegateNativeAura::GetWidgetDeleteCallback() {
+  return base::BindOnce(&CefBrowserPlatformDelegateNativeAura::WidgetDeleted,
+                        weak_ptr_factory_.GetWeakPtr());
+}
+
 // static
 base::TimeTicks CefBrowserPlatformDelegateNativeAura::GetEventTimeStamp() {
   return base::TimeTicks::Now();
@@ -279,6 +285,11 @@ int CefBrowserPlatformDelegateNativeAura::TranslateUiChangedButtonFlags(
   return result;
 }
 
+void CefBrowserPlatformDelegateNativeAura::WidgetDeleted() {
+  DCHECK(window_widget_);
+  window_widget_ = nullptr;
+}
+
 content::RenderWidgetHostViewAura*
 CefBrowserPlatformDelegateNativeAura::GetHostView() const {
   if (!web_contents_) {

libcef/browser/native/browser_platform_delegate_native_aura.h

@@ -7,6 +7,7 @@
 
 #include "libcef/browser/native/browser_platform_delegate_native.h"
 
+#include "base/memory/weak_ptr.h"
 #include "ui/events/event.h"
 
 namespace content {
@@ -71,6 +72,8 @@ class CefBrowserPlatformDelegateNativeAura
   virtual gfx::Vector2d GetUiWheelEventOffset(int deltaX, int deltaY) const;
 
  protected:
+  base::OnceClosure GetWidgetDeleteCallback();
+
   static base::TimeTicks GetEventTimeStamp();
   static int TranslateUiEventModifiers(uint32 cef_modifiers);
   static int TranslateUiChangedButtonFlags(uint32 cef_modifiers);
@@ -80,7 +83,14 @@ class CefBrowserPlatformDelegateNativeAura
   views::Widget* window_widget_ = nullptr;
 
  private:
+  // Will only be called if the Widget is deleted before
+  // CefBrowserHostBase::DestroyBrowser() is called.
+  void WidgetDeleted();
+
   content::RenderWidgetHostViewAura* GetHostView() const;
+
+  base::WeakPtrFactory<CefBrowserPlatformDelegateNativeAura> weak_ptr_factory_{
+      this};
 };
 
 #endif  // CEF_LIBCEF_BROWSER_NATIVE_BROWSER_PLATFORM_DELEGATE_NATIVE_AURA_H_

libcef/browser/native/browser_platform_delegate_native_linux.cc

@@ -79,7 +79,7 @@ bool CefBrowserPlatformDelegateNativeLinux::CreateHostWindow() {
 
   CefWindowDelegateView* delegate_view = new CefWindowDelegateView(
       GetBackgroundColor(), window_x11_->TopLevelAlwaysOnTop(),
-      GetBoundsChangedCallback());
+      GetBoundsChangedCallback(), GetWidgetDeleteCallback());
   delegate_view->Init(static_cast<gfx::AcceleratedWidget>(window_info_.window),
                       web_contents_, gfx::Rect(gfx::Point(), rect.size()));
 

libcef/browser/native/browser_platform_delegate_native_win.cc

@@ -284,7 +284,8 @@ bool CefBrowserPlatformDelegateNativeWin::CreateHostWindow() {
       (top_level_window_ex_styles & WS_EX_TOPMOST) == WS_EX_TOPMOST;
 
   CefWindowDelegateView* delegate_view = new CefWindowDelegateView(
-      GetBackgroundColor(), always_on_top, GetBoundsChangedCallback());
+      GetBackgroundColor(), always_on_top, GetBoundsChangedCallback(),
+      GetWidgetDeleteCallback());
   delegate_view->Init(window_info_.window, web_contents_,
                       gfx::Rect(0, 0, dip_rect.width(), dip_rect.height()));
 
@@ -702,4 +703,4 @@ LRESULT CALLBACK CefBrowserPlatformDelegateNativeWin::WndProc(HWND hwnd,
   }
 
   return DefWindowProc(hwnd, message, wParam, lParam);
-}
+}

libcef/browser/native/window_delegate_view.cc

@@ -15,11 +15,12 @@
 CefWindowDelegateView::CefWindowDelegateView(
     SkColor background_color,
     bool always_on_top,
-    base::RepeatingClosure on_bounds_changed)
+    base::RepeatingClosure on_bounds_changed,
+    base::OnceClosure on_delete)
     : background_color_(background_color),
-      web_view_(nullptr),
       always_on_top_(always_on_top),
-      on_bounds_changed_(on_bounds_changed) {}
+      on_bounds_changed_(std::move(on_bounds_changed)),
+      on_delete_(std::move(on_delete)) {}
 
 void CefWindowDelegateView::Init(gfx::AcceleratedWidget parent_widget,
                                  content::WebContents* web_contents,
@@ -64,6 +65,10 @@ void CefWindowDelegateView::Init(gfx::AcceleratedWidget parent_widget,
   DCHECK(widget->is_top_level());
   // |widget| must be activatable for focus handling to work correctly.
   DCHECK(widget->widget_delegate()->CanActivate());
+
+  // WidgetDelegate::DeleteDelegate() will execute the registered callback.
+  RegisterDeleteDelegateCallback(base::BindOnce(
+      &CefWindowDelegateView::DeleteDelegate, base::Unretained(this)));
 }
 
 void CefWindowDelegateView::InitContent() {
@@ -72,6 +77,12 @@ void CefWindowDelegateView::InitContent() {
   AddChildView(web_view_);
 }
 
+void CefWindowDelegateView::DeleteDelegate() {
+  if (!on_delete_.is_null()) {
+    std::move(on_delete_).Run();
+  }
+}
+
 void CefWindowDelegateView::ViewHierarchyChanged(
     const views::ViewHierarchyChangedDetails& details) {
   if (details.is_add && details.child == this) {

libcef/browser/native/window_delegate_view.h

@@ -22,7 +22,8 @@ class CefWindowDelegateView : public views::WidgetDelegateView {
  public:
   CefWindowDelegateView(SkColor background_color,
                         bool always_on_top,
-                        base::RepeatingClosure on_bounds_changed);
+                        base::RepeatingClosure on_bounds_changed,
+                        base::OnceClosure on_delete);
 
   CefWindowDelegateView(const CefWindowDelegateView&) = delete;
   CefWindowDelegateView& operator=(const CefWindowDelegateView&) = delete;
@@ -36,6 +37,8 @@ class CefWindowDelegateView : public views::WidgetDelegateView {
   // Initialize the Widget's content.
   void InitContent();
 
+  void DeleteDelegate();
+
   // WidgetDelegateView methods:
   bool CanMaximize() const override { return true; }
   View* GetContentsView() override { return this; }
@@ -46,10 +49,12 @@ class CefWindowDelegateView : public views::WidgetDelegateView {
   void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
 
  private:
-  SkColor background_color_;
-  views::WebView* web_view_;
-  bool always_on_top_;
+  const SkColor background_color_;
+  const bool always_on_top_;
   base::RepeatingClosure on_bounds_changed_;
+  base::OnceClosure on_delete_;
+
+  views::WebView* web_view_ = nullptr;
 };
 
 #endif  // CEF_LIBCEF_BROWSER_NATIVE_WINDOW_DELEGATE_VIEW_H_