GPU DDK - libusc UAF via WebGPU shaders at MergeConsecutiveBarriersBP

A web page that contains unusual GPU shader code is loaded from the Internet into the GPU compiler process triggers a write use-after-free crash in the GPU shader compiler library. On certain platforms, when the compiler process has system privileges this could enable further exploits on the device.

The shader code contained in the web page executes a path in the compiler that held onto an out of date pointer, pointing to a freed memory object.