The xfs_ioc_fsgetxattr function in fs/xfs/linux-2.6/xfs_ioctl.c in the Linux kernel before 2.6.36-rc4 does not initialize a certain structure member, which allows local users to obtain potentially sensitive information from kernel stack memory via an ioctl call.
http://lists.opensuse.org/opensuse-security-announce/2010-09/msg00005.html
http://lists.opensuse.org/opensuse-security-announce/2010-10/msg00003.html
http://lists.opensuse.org/opensuse-security-announce/2010-11/msg00000.html
http://lists.opensuse.org/opensuse-security-announce/2011-02/msg00000.html
https://bugzilla.redhat.com/show_bug.cgi?id=630804
http://secunia.com/advisories/41284
http://secunia.com/advisories/41512
http://secunia.com/advisories/42890
http://secunia.com/advisories/46397
http://securitytracker.com/id?1024418
http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.36-rc4
http://www.openwall.com/lists/oss-security/2010/09/07/1
http://www.openwall.com/lists/oss-security/2010/09/07/12
http://www.redhat.com/support/errata/RHSA-2010-0839.html
http://www.redhat.com/support/errata/RHSA-2011-0007.html
http://www.ubuntu.com/usn/USN-1000-1
http://www.vmware.com/security/advisories/VMSA-2011-0012.html