escape challenge (user-land oob --> kernel-land bof --> emulator heap corruption)

[writeup](https://ptr-yudai.hatenablog.com/entry/2020/12/09/200118#pwn-383pts-Pwnception-6-solves)

Original writeup (https://ptr-yudai.hatenablog.com/entry/2020/12/09/200118#pwn-383pts-Pwnception-6-solves).