There are a number of active Linux Kernel hardening projects and this page gives details on some of them.
Smatch is a static analysis tool for C.
Project page: http://repo.or.cz/w/smatch.git Contributors: Dan Carpenter, Fengguang Wu
Trinity is a Linux system call fuzzer.
Project page: http://codemonkey.org.uk/projects/trinity/ Contributors: Dave Jones, Fengguang Wu