The handle_dr function in arch/x86/kvm/vmx.c in the KVM subsystem in the Linux kernel before 2.6.31.1 does not properly verify the Current Privilege Level (CPL) before accessing a debug register, which allows guest OS users to cause a denial of service (trap) on the host OS via a crafted application.
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=0a79b009525b160081d75cef5dbf45817956acf2
marc.info/?l=oss-security&m=125678631403558&w=2
marc.info/?l=oss-security&m=125680666827148&w=2
www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.30.9
www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.31.1
www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.32-rc1
www.mandriva.com/security/advisories?name=MDVSA-2010:198
www.redhat.com/support/errata/RHSA-2010-0126.html
www.securityfocus.com/bid/37221
www.ubuntu.com/usn/usn-864-1
bugzilla.redhat.com/show_bug.cgi?id=531660
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9892