A flaw was found in KVM. When updating a guest's page table entry, vm_pgoff was improperly used as the offset to get the page's pfn. As vad…

A flaw was found in KVM. When updating a guest's page table entry, vm_pgoff was improperly used as the offset to get the page's pfn. As vaddr and vm_pgoff are controllable by user-mode processes, this flaw allows unprivileged local users on the host to write outside the userspace region and potentially corrupt the kernel, resulting in a denial of service condition.