Commit 883a1d49 authored Jun 18, 2014 by Lars-Peter Clausen Committed by Takashi Iwai Jun 18, 2014

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>

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);

Admin message