[PATCH v3 6/6] ALSA: hda: Add input value sanity checks to HDMI channel map controls

[Takashi Iwai <tiwai@suse.de>]

Add a simple sanity check to HD-audio HDMI Channel Map controls.
Although the value might not be accepted for the actual connection, we
can filter out some bogus values beforehand, and that should be enough
for making kselftest happier.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/hda/hdmi_chmap.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/sound/hda/hdmi_chmap.c b/sound/hda/hdmi_chmap.c
index 5d8e1d944b0a..7b276047f85a 100644
--- a/sound/hda/hdmi_chmap.c
+++ b/sound/hda/hdmi_chmap.c
@@ -753,6 +753,20 @@ static int hdmi_chmap_ctl_get(struct snd_kcontrol *kcontrol,
 	return 0;
 }
 
+/* a simple sanity check for input values to chmap kcontrol */
+static int chmap_value_check(struct hdac_chmap *hchmap,
+			     const struct snd_ctl_elem_value *ucontrol)
+{
+	int i;
+
+	for (i = 0; i < hchmap->channels_max; i++) {
+		if (ucontrol->value.integer.value[i] < 0 ||
+		    ucontrol->value.integer.value[i] > SNDRV_CHMAP_LAST)
+			return -EINVAL;
+	}
+	return 0;
+}
+
 static int hdmi_chmap_ctl_put(struct snd_kcontrol *kcontrol,
 			      struct snd_ctl_elem_value *ucontrol)
 {
@@ -764,6 +778,10 @@ static int hdmi_chmap_ctl_put(struct snd_kcontrol *kcontrol,
 	unsigned char chmap[8], per_pin_chmap[8];
 	int i, err, ca, prepared = 0;
 
+	err = chmap_value_check(hchmap, ucontrol);
+	if (err < 0)
+		return err;
+
 	/* No monitor is connected in dyn_pcm_assign.
 	 * It's invalid to setup the chmap
 	 */
-- 
2.43.0