The IA32 system call emulation functionality in arch/x86/ia32/ia32entry.S in the Linux kernel before 2.6.36-rc4-git2 on the x86_64 platform does not zero extend the %eax register after the 32-bit entry path to ptrace is used, which allows local users to gain privileges by triggering an out-of-bounds access to the system call table using the %rax register. NOTE: this vulnerability exists because of a CVE-2007-4573 regression.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=36d001c70d8a0144ac1d038f6876c484849a74de
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=eefdca043e8391dcd719711716492063030b55ac
lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.html
lists.opensuse.org/opensuse-security-announce/2011-02/msg00000.html
secunia.com/advisories/42758
sota.gen.nz/compat2/
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-2010:247
www.openwall.com/lists/oss-security/2010/09/16/1
www.openwall.com/lists/oss-security/2010/09/16/3
www.redhat.com/support/errata/RHSA-2010-0842.html
www.ubuntu.com/usn/USN-1041-1
www.vupen.com/english/advisories/2010/3117
www.vupen.com/english/advisories/2011/0070
www.vupen.com/english/advisories/2011/0298
bugzilla.redhat.com/show_bug.cgi?id=634449