diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index e1c205a6126..9f06b6c075c 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1428,7 +1428,9 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid, void *r
 	int input_pins, num_ins, num_outs;
 	int pin, ich, err;
 
-	if (desc->bLength < 11 || ! (input_pins = desc->bNrInPins) || ! (num_outs = uac_mixer_unit_bNrChannels(desc))) {
+	if (desc->bLength < 11 || ! (input_pins = desc->bNrInPins) ||
+	    desc->bLength < sizeof(*desc) + desc->bNrInPins ||
+	    !(num_outs = uac_mixer_unit_bNrChannels(desc))) {
 		snd_printk(KERN_ERR "invalid MIXER UNIT descriptor %d\n", unitid);
 		return -EINVAL;
 	}