sound: control: fix minimum TLV length
Allow TLV blocks that do not have any values; the smallest possible TLV
is an empty container or one where the information is only in the tag.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/core/control.c b/sound/core/control.c
index 6a4764d..439ce64 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1100,7 +1100,7 @@
if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
return -EFAULT;
- if (tlv.length < sizeof(unsigned int) * 3)
+ if (tlv.length < sizeof(unsigned int) * 2)
return -EINVAL;
down_read(&card->controls_rwsem);
kctl = snd_ctl_find_numid(card, tlv.numid);