The util_format_is_pure_uint function in vrend_renderer.c in Virgil 3d project (aka virglrenderer) 0.6.0 and earlier allows local guest OS users to cause a denial of service (NULL pointer dereference) via a crafted VIRGL_CCMD_CLEAR command.
https://cgit.freedesktop.org/virglrenderer/commit/?id=48f67f60967f963b698ec8df57ec6912a43d6282
https://bugzilla.redhat.com/show_bug.cgi?id=1420246