Re: [PATCH v3] tun: bail out from tun_get_user() if the skb is empty

From: Alexander Potapenko <glider@google.com>
Date: Thu, 28 Sep 2017 11:32:37 +0200

KMSAN (https://github.com/google/kmsan) reported accessing uninitialized
skb->data[0] in the case the skb is empty (i.e. skb->len is 0):

 ...

Make sure tun_get_user() doesn't touch skb->data[0] unless there is
actual data.

 ...

Signed-off-by: Alexander Potapenko <glider@google.com>

Applied and queued up for -stable, thanks.