The load_segment_descriptor implementation in arch/x86/kvm/emulate.c in the Linux kernel before 4.9.5 improperly emulates a MOV SS, NULL selector instruction, which allows guest OS users to cause a denial of service (guest OS crash) or gain guest OS privileges via a crafted application. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2017-2583
