This is a patch to fix a local root exploit revealed in early February 2008. To apply it to the 2.6.21.5 kernel, do this: cd /usr/src/linux-2.6.21.5 zcat splice.c.gz | patch -p1 You'll then be ready to build patched kernels from the config files in the other kernel-* directories. Copy the config file to /usr/src/linux-2.6.21.5/.config, run "make oldconfig", run "make bzImage", and then copy the files into (for example) kernel-generic: cd kernel-generic cp -a /usr/src/linux-2.6.21.5/System.map \ /usr/src/linux-2.6.21.5/.config \ /usr/src/linux-2.6.21.5/arch/i386/boot/bzImage . gzip -9 System.map mv .config config Then build the Slackware kernel package like this: ./kernel-generic.SlackBuild Don't forget to run lilo again if you use that.