[sanskarIN]

Confirmed code-level vulnerability

Qt 6.8 documents that QQuickWindow::createRectangleNode() and createImageNode() return null when the scene graph has not initialized. FrameView::updatePaintNode() dereferenced these native pointers without checking, and also forwarded a potentially null texture to the image node. This could cause a native access violation during window initialization, recreation, or teardown.

Official Qt docs: https://doc.qt.io/qt-6.8/qquickwindow.html

Fix

• If FrameView has no QQuickWindow, return the existing node without accessing the window.
• Check rectangle and image node factory returns before using them.
• Do not append a newly created image node until a non-null texture exists.
• If a replacement texture cannot be created, keep the previous valid image and retry on a later update.
• Add a regression for a detached FrameView and the attach-then-detach lifecycle. Qt's scene graph may already be initialized by a newly constructed QQuickWindow under the software backend, so the test does not presume initialization timing.
• Run the new GUI test on Linux and Windows with the offscreen software Qt Quick backend.

Relationship to crash investigation

Tracked separately from Windows ARM startup issue #185 and user export issue #175. This prevents specific null dereferences, but is not proof that they caused either observed 0xC0000005 event.

Gates

• Formatting, Windows/Linux GUI compilation and regression.
• Linux sanitizer and GCC/static-analysis checks.
• Windows packaged verification, including ARM.

No stable release, no change to export FPS, and no claim of completed native crash root cause.