please try the following patch.
Index: uhidev.c
===================================================================
RCS file: /cvs/src/sys/dev/usb/uhidev.c,v
retrieving revision 1.56
diff -u -p -r1.56 uhidev.c
--- uhidev.c 19 Mar 2014 08:59:37 -0000 1.56
+++ uhidev.c 23 Mar 2014 10:45:14 -0000
@@ -387,7 +387,8 @@ uhidev_detach(struct device *self, int f
* IDs, this is a hack since we need a dev -> Report ID mapping
* for uhidev_intr().
*/
- if (sc->sc_nrepid > 0 && sc->sc_subdevs[0] == sc->sc_subdevs[1])
+ if (sc->sc_nrepid > 0 && sc->sc_subdevs[0] != NULL &&
+ sc->sc_subdevs[0] == sc->sc_subdevs[1])
return (config_detach(&sc->sc_subdevs[0]->sc_dev, flags));
for (i = 0; i < sc->sc_nrepid; i++) {
