GPU DDK - Page UAF read in PMMETA_PROTECT heap memory

Software installed and run as a non-privileged user may conduct a sequence of improper GPU system calls causing use after free, which helps in facilitating unprivileged memory access from a shader code.

Triggering failure path in the MMU mapping logic by a malicious code could lead to incomplete cleanup of an internal driver state, allowing for future unauthorized access to the contents of the physical memory.