[patch 1/1][NETNS] resend: fix net released by rcu callback

[Eric W. Biederman]

Daniel Lezcano <dlezcano at fr.ibm.com> writes:

> Yes, I had this problem when doing ipv6 isolation for netns49. The ipv6
> subsystem creation failed and the different subsystem where rollbacked in the
> setup_net function.
> When the network namespace was about to be freed in free_net function, I had the
> error with an usage refcount different from zero.
> It appears that was coming from core/neighbour.c
>
> neigh_parms_release
>  -> neigh_rcu_free_parms
>    -> neigh_parms_put
>      -> neigh_parms_destroy
>        -> release_net
>
> The free_net function was called before rcu callback neigh_rcu_free_parms.

Ok. Cool.  It is good to know that this patch was tested.  These kinds
of subtle fixes are always more solid when you can actually test them.

Eric