This is an old POC for CVE-2011-1237 on Windows 7 written in 2013. The vulnerability was discovered by Tarjei Mandt (@kernelpool) and explain in his paper Kernel Attacks through User-Mode Callbacks.
Several things are hardcoded in this POC and it call the Null page which does not work anymore. The exploit is describe in my talk A Look into the Windows Kernel.
The only thing the shellcode does is trigger a breakpoint.