The virtqueue_map_desc function in hw/virtio/virtio.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a zero length for the descriptor buffer.
https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg06246.html
https://security.gentoo.org/glsa/201609-01