arch/x86/kvm/mmu.c in the Linux kernel through 4.13.5, when nested virtualisation is used, does not properly traverse guest pagetable entries to resolve a guest virtual address, which allows L1 guest OS users to execute arbitrary code on the host OS or cause a denial of service (incorrect index during page walking, and host OS crash), aka an MMU potential stack buffer overrun. https://nvd.nist.gov/vuln/detail/CVE-2017-12188
CONFIG_KVM=y
