Ksplice : an automatic system for rebootless kernel security updates

Abstract

Ksplice allows system administrators to apply security patches to their operating system kernels without having to reboot. Based on a source code patch and the kernel source code to be patched, Ksplice applies the patch to the corresponding running kernel, without requiring work from a programmer. To be fully automatic, Ksplice's design is limited to patches that do not introduce semantic changes to data structures, but a study of all significant x86-32 Linux security patches from May 2005 to December 2007 finds that only eight patches of 50 make semantic changes. An evaluation with Debian and kernel.org Linux kernels shows that Ksplice can automatically apply the remaining 42 patches, which means that 84% of the Linux kernel vulnerabilities from this interval can be corrected by Ksplice without the need for rebooting.