ALSA: control: Make sure that id->index does not overflow

The ALSA control code expects that the range of assigned indices to a control is
continuous and does not overflow. Currently there are no checks to enforce this.
If a control with a overflowing index range is created that control becomes
effectively inaccessible and unremovable since snd_ctl_find_id() will not be
able to find it. This patch adds a check that makes sure that controls with a
overflowing index range can not be created.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Lars-Peter Clausen 2014-06-18 13:32:35 +02:00 committed by Takashi Iwai
parent ac902c112d
commit 883a1d49f0

View File

@ -342,6 +342,9 @@ int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
if (snd_BUG_ON(!card || !kcontrol->info))
goto error;
id = kcontrol->id;
if (id.index > UINT_MAX - kcontrol->count)
goto error;
down_write(&card->controls_rwsem);
if (snd_ctl_find_id(card, &id)) {
up_write(&card->controls_rwsem);