Integer signedness error in NetBSD 4.0, 5.0, and NetBSD-current before 2010-01-21 allows local users to cause a denial of service (kernel panic) via a negative mixer index number being passed to (1) the azalia_query_devinfo function in the azalia audio driver (src/sys/dev/pci/azalia.c) or (2) the hdaudio_afg_query_devinfo function in the hdaudio audio driver (src/sys/dev/pci/hdaudio/hdaudio_afg.c).