arch/i386/kernel/sysenter.c in the Virtual Dynamic Shared Objects (vDSO) implementation in the Linux kernel before 2.6.21 does not properly check boundaries, which allows local users to gain privileges or cause a denial of service via unspecified vectors, related to the install_special_mapping, syscall, and syscall32_nopage functions.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10602
https://bugzilla.redhat.com/show_bug.cgi?id=460251
http://www.securitytracker.com/id?1021137
http://www.redhat.com/support/errata/RHSA-2008-0957.html
http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.21
http://www.debian.org/security/2008/dsa-1687
http://secunia.com/advisories/33180
http://secunia.com/advisories/32759
http://secunia.com/advisories/32485
http://lists.opensuse.org/opensuse-security-announce/2008-11/msg00001.html