From secunia security advisory at $URL: Description: The vulnerability is caused due to a NULL pointer dereference error within the implementation of the GHASH algorithm, which can be exploited to e.g. cause a crash via a specially crafted application. The vulnerability is confirmed in version 2.6.39.4. Other versions may also be affected. Solution: Fixed in the GIT repository. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=7ed47b7d142ec99ad6880bbbec51e9f12b3af74c
There are no longer any 2.x kernels available in the repository with the exception of sys-kernel/xbox-sources which is unsupported by security.