The vc4getbcl function in drivers/gpu/drm/vc4/vc4gem.c in the VideoCore DRM driver in the Linux kernel before 4.9.7 does not set an errno value upon certain overflow detections, which allows local users to cause a denial of service (incorrect pointer dereference and OOPS) via inconsistent size values in a VC4SUBMIT_CL ioctl call.