The vmsplice_to_user function in fs/splice.c in the Linux kernel 2.6.22 through 2.6.24 does not validate a certain userspace pointer before dereference, which might allow local users to access arbitrary kernel memory locations.
https://www.redhat.com/archives/fedora-package-announce/2008-February/msg00255.html
https://www.redhat.com/archives/fedora-package-announce/2008-February/msg00254.html
http://www.vupen.com/english/advisories/2008/0487/references
http://www.securityfocus.com/bid/27799
http://www.securityfocus.com/bid/27704
http://www.securityfocus.com/archive/1/487982/100/0/threaded