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Commit 883a1d49 authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Takashi Iwai
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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: default avatarLars-Peter Clausen <lars@metafoo.de>
Acked-by: default avatarJaroslav Kysela <perex@perex.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent ac902c11

sound/core/control.c

+3 −0
Original line number Diff line number Diff line
@@ -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);