Microsoft Windows Kernel - 'bGetRealizedBrush' Use-After-Free (MS15-097)

Source: https://code.google.com/p/google-security-research/issues/detail?id=458

---
The attached testcase crashes Win 7 with Special Pool on win32k while accessing freed memory in bGetRealizedBrush.
---

Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/38277.zip