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>

1 files changed, 1 insertions, 1 deletions

diff --git a/sound/core/control.c b/sound/core/control.c
index 6a4764dcb180..439ce64f9d82 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1100,7 +1100,7 @@ static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
 
         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);