Windows Kernel 64-bit pool memory disclosure in win32k!UMPDOBJ::LockSurface(CVE-2018-0813)

We have discovered that the win32k!UMPDOBJ::LockSurface function discloses portions of uninitialized pool memory to user-mode clients. The bug was encountered on Windows 7 64-bit; other versions were not tested. The leak was detected in the context of the splwow64.exe process, under the following...