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

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>
(cherry picked from commit 883a1d49f0d77d30012f114b2e19fc141beb3e8e)
[wt: part 1 of CVE-2014-4656 fix]
Signed-off-by: Willy Tarreau <w@1wt.eu>