diff --git a/sys/dev/sound/pcm/channel.c b/sys/dev/sound/pcm/channel.c
--- a/sys/dev/sound/pcm/channel.c
+++ b/sys/dev/sound/pcm/channel.c
@@ -2092,9 +2092,23 @@
 int
 chn_setformat(struct pcm_channel *c, uint32_t format)
 {
-	uint32_t oldformat, oldspeed;
+	uint32_t oldformat, oldspeed, x;
 	int ret;
 
+	/*
+	 * Detect unsupported formats. This checks if the format is supported
+	 * in the first place, and that no more than 1 format is specified at
+	 * the same time.
+	 */
+	x = format & AFMT_CONVERTIBLE;
+	if ((x & (x - 1)) != 0) {
+		if (snd_verbose > 3) {
+			device_printf(c->dev, "%s(): Unsupported format: "
+			    "0x%08x\n", __func__, format);
+		}
+		return (EINVAL);
+	}
+
 	/* XXX force stereo */
 	if ((format & AFMT_PASSTHROUGH) && AFMT_CHANNEL(format) < 2) {
 		format = SND_FORMAT(format, AFMT_PASSTHROUGH_CHANNEL,