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authorLars-Peter Clausen <lars@metafoo.de>2014-06-18 13:32:35 +0200
committerTakashi Iwai <tiwai@suse.de>2014-06-18 15:13:37 +0200
commit883a1d49f0d77d30012f114b2e19fc141beb3e8e (patch)
tree619fde383d5c4645712c498bf1af52df6216ac22
parentac902c112d90a89e59916f751c2745f4dbdbb4bd (diff)
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>
-rw-r--r--sound/core/control.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/sound/core/control.c b/sound/core/control.c
index 8d6e4bae7407..f0b0e14497a5 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -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);