The compat_alloc_user_space functions in include/asm/compat.h files in the Linux kernel before 2.6.36-rc4-git2 on 64-bit platforms do not properly allocate the userspace memory required for the 32-bit compatibility layer, which allows local users to gain privileges by leveraging the ability of the compat_mc_getsockopt function (aka the MCAST_MSFILTER getsockopt support) to control a certain length value, related to a “stack pointer underflow” issue, as exploited in the wild in September 2010.
archives.neohapsis.com/archives/fulldisclosure/2010-09/0273.html
archives.neohapsis.com/archives/fulldisclosure/2010-09/0278.html
blog.ksplice.com/2010/09/cve-2010-3081/
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=c41d68a513c71e35a14f66d71782d27a79a81ea6
isc.sans.edu/diary.html?storyid=9574
lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.html
lists.opensuse.org/opensuse-security-announce/2010-10/msg00003.html
lists.opensuse.org/opensuse-security-announce/2011-02/msg00000.html
marc.info/?l=oss-security&m=128461522230211&w=2
secunia.com/advisories/42384
secunia.com/advisories/43315
sota.gen.nz/compat1/
www.kernel.org/pub/linux/kernel/v2.6/snapshots/patch-2.6.36-rc4-git2.log
www.mandriva.com/security/advisories?name=MDVSA-2010:198
www.mandriva.com/security/advisories?name=MDVSA-2010:214
www.mandriva.com/security/advisories?name=MDVSA-2010:247
www.redhat.com/support/errata/RHSA-2010-0758.html
www.redhat.com/support/errata/RHSA-2010-0842.html
www.redhat.com/support/errata/RHSA-2010-0882.html
www.securityfocus.com/archive/1/514938/30/30/threaded
www.securityfocus.com/archive/1/516397/100/0/threaded
www.vmware.com/security/advisories/VMSA-2010-0017.html
www.vmware.com/security/advisories/VMSA-2011-0003.html
www.vupen.com/english/advisories/2010/3083
www.vupen.com/english/advisories/2010/3117
www.vupen.com/english/advisories/2011/0298
access.redhat.com/kb/docs/DOC-40265
bugzilla.redhat.com/show_bug.cgi?id=634457