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

Orabug: 23330832

[ Upstream commit 360a8245680053619205a3ae10e6bfe624a5da1d ]

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@oracle.com>
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Cc: <stable@vger.kernel.org> # v3.9+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
(cherry picked from commit 6cf9d4c32e8e2716eb8e9cb578dbcb2b2cad04b3)

Signed-off-by: Dan Duval <dan.duval@oracle.com>

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 225b78b4ef125f5133572300f372bf7b411713f7..58a24624ecc0ca4c88ee541c1b3c6fbccc63a030 100644 (file)
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -432,7 +432,8 @@ 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;