Design/Logic Flaw

The fpufxrstor function in arch/x86/i387.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits...

CVE-2016-3159

CVE-2016-3159 affects Xen 4.x on AMD64, where the fpu_fxrstor handler in arch/x86/i387.c mishandles writes to the FSW.ES bit, enabling a local guest to read sensitive register content from another guest by exploiting pending exception/mask bits. The issue stems from an incorrect fix for CVE-2013-...