arch/x86/kvm/emulate.c in the Linux kernel through 4.9.3 allows local users to obtain sensitive information from kernel memory or cause a denial of service (use-after-free) via a crafted application that leverages instruction emulation for fxrstor, fxsave, sgdt, and sidt.
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=129a72a0d3c8e139a04512325384fe5ac119e74d
www.debian.org/security/2017/dsa-3791
www.openwall.com/lists/oss-security/2017/01/13/7
www.securityfocus.com/bid/95430
www.securitytracker.com/id/1037603
bugzilla.redhat.com/show_bug.cgi?id=1413001
github.com/torvalds/linux/commit/129a72a0d3c8e139a04512325384fe5ac119e74d
usn.ubuntu.com/3754-1/