The Xen hypervisor block backend driver for Linux kernel 2.6.18, when running on a 64-bit host with a 32-bit paravirtualized guest, allows local privileged users in the guest OS to cause a denial of service (host OS crash) via a request that specifies a large number of blocks.
secunia.com/advisories/30116
secunia.com/advisories/32918
www.redhat.com/support/errata/RHSA-2008-0233.html
www.securityfocus.com/bid/29082
www.ubuntu.com/usn/usn-679-1
bugzilla.redhat.com/show_bug.cgi?id=369531
exchange.xforce.ibmcloud.com/vulnerabilities/42274
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9452