ALSA: hda - Fix static checker warning in patch_hdmi.c

The static checker warning is:

	sound/pci/hda/patch_hdmi.c:460 hdmi_eld_ctl_get()
	error: __memcpy() 'eld->eld_buffer' too small (256 vs 512)

I have a hard time figuring out if this can ever cause an information leak
(I don't think so), but nonetheless it does not hurt to increase the
robustness of the code.

Fixes: 68e03de ('ALSA: hda - hdmi: Do not expose eld data when eld is invalid')
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: David Henningsson <[email protected]>
Cc: <[email protected]> # v3.9+
Signed-off-by: Takashi Iwai <[email protected]>

Author: David Henningsson

sound/pci/hda/patch_hdmi.c

@@ -448,7 +448,8 @@ static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
 	eld = &per_pin->sink_eld;
 
 	mutex_lock(&per_pin->lock);
-	if (eld->eld_size > ARRAY_SIZE(ucontrol->value.bytes.data)) {
+	if (eld->eld_size > ARRAY_SIZE(ucontrol->value.bytes.data) ||
+	    eld->eld_size > ELD_MAX_SIZE) {
 		mutex_unlock(&per_pin->lock);
 		snd_BUG();
 		return -EINVAL;