The vmw_surface_define_ioctl function in drivers/gpu/drm/vmwgfx/vmwgfx_surface.c in the Linux kernel through 4.10.5 does not check for a zero value of certain levels data, which allows local users to cause a denial of service (ZERO_SIZE_PTR dereference, and GPF and possibly panic) via a crafted ioctl call for a /dev/dri/renderD* device. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2017-7261
