ALSA: hda - hdmi: Do not expose eld data when eld is invalid

Previously, it was possible to read the eld data of the previous monitor connected. This should not be allowed. Also refactor the function slightly. Signed-off-by: David Henningsson <[email protected]> Signed-off-by: Takashi Iwai <[email protected]>
Noltari · Feb 19, 2013 · 68e03de · 68e03de
1 parent bbfd8a1
commit 68e03de
Showing 1 changed file with 18 additions and 7 deletions.
diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
@@ -343,14 +343,16 @@ static int hdmi_eld_ctl_info(struct snd_kcontrol *kcontrol,
 			struct snd_ctl_elem_info *uinfo)
 {
 	struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
-	struct hdmi_spec *spec;
+	struct hdmi_spec *spec = codec->spec;
+	struct hdmi_eld *eld;
 	int pin_idx;
 
-	spec = codec->spec;
 	uinfo->type = SNDRV_CTL_ELEM_TYPE_BYTES;
 
 	pin_idx = kcontrol->private_value;
-	uinfo->count = spec->pins[pin_idx].sink_eld.eld_size;
+	eld = &spec->pins[pin_idx].sink_eld;
+
+	uinfo->count = eld->eld_valid ? eld->eld_size : 0;
 
 	return 0;
 }
@@ -359,14 +361,23 @@ static int hdmi_eld_ctl_get(struct snd_kcontrol *kcontrol,
 			struct snd_ctl_elem_value *ucontrol)
 {
 	struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
-	struct hdmi_spec *spec;
+	struct hdmi_spec *spec = codec->spec;
+	struct hdmi_eld *eld;
 	int pin_idx;
 
-	spec = codec->spec;
 	pin_idx = kcontrol->private_value;
+	eld = &spec->pins[pin_idx].sink_eld;
+
+	if (eld->eld_size > ARRAY_SIZE(ucontrol->value.bytes.data)) {
+		snd_BUG();
+		return -EINVAL;
+	}
 
-	memcpy(ucontrol->value.bytes.data,
-		spec->pins[pin_idx].sink_eld.eld_buffer, ELD_MAX_SIZE);
+	memset(ucontrol->value.bytes.data, 0,
+	       ARRAY_SIZE(ucontrol->value.bytes.data));
+	if (eld->eld_valid)
+		memcpy(ucontrol->value.bytes.data, eld->eld_buffer,
+		       eld->eld_size);
 
 	return 0;
 }