Story

Also don't think you can blow it off because it's "only a local exploit". All it takes is a (otherwise fairly harmless if the kernel bug was not there) vulnerability in something else that could give an attacker an avenue to get to a local exploit remotely. It happened to me a few years ago. Fortunately, when the attacker did hit my server (via a buggy PHP application), I had actually patched the kernel vulnerability they tried to exploit so they got nowhere (but left some evidence as to who they were).