This whitepaper is the Linux Exploit Writing Tutorial Part 2 – Stack Overflow ASLR bypass using ret2reg instruction from vulnerable_1.
You can download it from the following link: https://packetstormsecurity.com/files/download/99766/lewt2-aslrbypass.pdf
Source: https://packetstormsecurity.com/files/99766/Linux-Exploit-Writing-Tutorial-Part-2.html