From: David Miller <davem@davemloft.net>
To: sd@queasysnail.net
Cc: netdev@vger.kernel.org, sergei.shtylyov@cogentembedded.com
Subject: Re: [PATCH net v2] l2tp: fix use-after-free during module unload
Date: Fri, 02 Sep 2016 11:45:10 -0700 (PDT) [thread overview]
Message-ID: <20160902.114510.2079683210993243165.davem@davemloft.net> (raw)
In-Reply-To: <996e12b7faf7fd20ba9c0c76614fd5bb4a3d70c4.1472804437.git.sd@queasysnail.net>
From: Sabrina Dubroca <sd@queasysnail.net>
Date: Fri, 2 Sep 2016 10:22:54 +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_exit_net() 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 <sd@queasysnail.net>
> ---
> v2: fix typo in commit message, spotted by Sergei Shtylyov
Applied.
prev parent reply other threads:[~2016-09-02 18:45 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-02 8:22 [PATCH net v2] l2tp: fix use-after-free during module unload Sabrina Dubroca
2016-09-02 18:45 ` David Miller [this message]
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