CVE-2010-4255: Undefined Security Weakness

The fixuppagefault function in arch/x86/traps.c in Xen 4.0.1 and earlier on 64-bit platforms, when paravirtualization is enabled, does not verify that kernel mode is used to call the handlegdtldtmappingfault function, which allows guest OS users to cause a denial of service host OS BUGON via a...