timetobleed.com/a-closer-look-at-a-recent-privilege-escalation-bug-in-linux-cve-2013-2094/
You need to build the C file of your choice like this:
gcc -O2 file-name.c
-O2 is required due to how the exploit actually works (see the blog post for more information).
I thought the original exploit was cool and really interesting, but hard to understand especially for beginners so I decided to rewrite it a bit, add lots of comments, and write a blog post about it.