kernel: drm_modeset_ctl signedness issue

Integer signedness error in the drmmodesetctl function in 1 drivers/gpu/drm/drmirq.c in the Direct Rendering Manager DRM subsystem in the Linux kernel before 2.6.38 and 2 sys/dev/pci/drm/drmirq.c in the kernel in OpenBSD before 4.9 allows local users to trigger out-of-bounds write operations, and...