net: add BUG_ON if kernel advertises msg_namelen > sizeof(struct sockaddr_storage)
In that case it is probable that kernel code overwrote part of the
stack. So we should bail out loudly here.
The BUG_ON may be removed in future if we are sure all protocols are
conformant.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>