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 <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 32adaa6c5627d397c5c77b3d9bd60afc0ef108f6..6bcdd667f514d970d210b72700a9c4609c9993df 100644 (file)
--- 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;
 }