From: Sabrina Dubroca <s...@queasysnail.net>
Date: Tue, 30 Aug 2016 16:05:16 +0200
> Tunnel deletion is delayed by both a workqueue (l2tp_tunnel_delete -> wq
> -> l2tp_tunnel_del_work) and RCU (sk_destruct -> RCU ->
> l2tp_tunnel_destruct).
>
> By the time l2tp_tunnel_destruct() runs to destroy the tunnel and finish
> destroying the socket, the private data reserved via the net_generic
> mechanism has already been freed, but l2tp_tunnel_destruct() actually
> uses this data.
>
> Make sure tunnel deletion for the netns has completed before returning
> from l2tp_net_exit() by first flushing the tunnel removal workqueue, and
> then waiting for RCU callbacks to complete.
>
> Fixes: 167eb17e0b17 ("l2tp: create tunnel sockets in the right namespace")
> Signed-off-by: Sabrina Dubroca <s...@queasysnail.net>
Please resubmit this with Sergei's feedback addressed.
Thanks.
