--- sys/dev/sound/pcm/feeder_eq.c	2026-06-29 12:51:19.000000000 +0000
+++ sys/dev/sound/pcm/feeder_eq.c
@@ -342,6 +342,10 @@ feed_eq_init(struct pcm_feeder *f)
 	if (f->desc->in != f->desc->out)
 		return (EINVAL);

+	if (AFMT_CHANNEL(f->desc->in) < SND_CHN_MIN ||
+	    AFMT_CHANNEL(f->desc->in) > SND_CHN_MAX)
+		return (EINVAL);
+
 	biquad_op = NULL;

 	for (i = 0; i < FEEDEQ_BIQUAD_TAB_SIZE && biquad_op == NULL; i++) {