[PATCH 4.2.y-ckt 103/273] ALSA: hda - Fix static checker warning in patch_hdmi.c

[Kamal Mostafa]

4.2.8-ckt5 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: David Henningsson <david.henningsson at canonical.com>

commit 360a8245680053619205a3ae10e6bfe624a5da1d upstream.

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: 68e03de98507 ('ALSA: hda - hdmi: Do not expose eld data when eld is invalid')
Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: David Henningsson <david.henningsson at canonical.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/pci/hda/patch_hdmi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 9d1f91d..1383ce4 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -433,7 +433,8 @@ 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;
-- 
2.7.0