fs/direct-io.c in the dio subsystem in the Linux kernel before 2.6.23 does not properly zero out the dio struct, which allows local users to cause a denial of service (OOPS), as demonstrated by a certain fio test.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10053
https://bugzilla.redhat.com/show_bug.cgi?id=461082
http://www.ubuntu.com/usn/usn-659-1
http://www.securityfocus.com/bid/31515
http://www.openwall.com/lists/oss-security/2008/09/04/1
http://www.debian.org/security/2008/dsa-1653
http://rhn.redhat.com/errata/RHSA-2008-0972.html
http://lists.opensuse.org/opensuse-security-announce/2008-12/msg00000.html
http://lists.opensuse.org/opensuse-security-announce/2008-11/msg00001.html
http://lists.opensuse.org/opensuse-security-announce/2008-10/msg00008.html
http://lists.opensuse.org/opensuse-security-announce/2008-10/msg00007.html
http://lists.opensuse.org/opensuse-security-announce/2008-10/msg00000.html