From: Lars-Peter Clausen Date: Wed, 18 Jun 2014 11:32:35 +0000 (+0200) Subject: ALSA: control: Make sure that id->index does not overflow X-Git-Tag: v3.2.61~39 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7500568b7633324e7c4282bb8baa3ff3f17fd7a;p=thirdparty%2Fkernel%2Fstable.git ALSA: control: Make sure that id->index does not overflow commit 883a1d49f0d77d30012f114b2e19fc141beb3e8e upstream. 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 Acked-by: Jaroslav Kysela Signed-off-by: Takashi Iwai Signed-off-by: Ben Hutchings --- diff --git a/sound/core/control.c b/sound/core/control.c index d3f17deecf0c2..92105946dcfc7 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -341,6 +341,9 @@ 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);