From: Roopa Prabhu <roopa@cumulusnetworks.com>
To: Taehee Yoo <ap420073@gmail.com>
Cc: David Miller <davem@davemloft.net>, Netdev <netdev@vger.kernel.org>
Subject: Re: [PATCH net] vxlan: do not destroy fdb if register_netdevice() is failed
Date: Mon, 24 Jun 2019 21:12:01 -0700 [thread overview]
Message-ID: <CAJieiUjri=-w2PqB9q5fEa=4jqkTWSfK0dUwnT7Cvxdo2sRRzg@mail.gmail.com> (raw)
In-Reply-To: <CAMArcTXWNY6WTjuBuUVxeb3c6dTqf8wf6sHFmNL5SvsGBbPqdQ@mail.gmail.com>
On Sun, Jun 23, 2019 at 7:18 PM Taehee Yoo <ap420073@gmail.com> wrote:
>
> On Mon, 24 Jun 2019 at 03:07, David Miller <davem@davemloft.net> wrote:
> >
>
> Hi David,
>
> Thank you for the review!
>
> > From: Taehee Yoo <ap420073@gmail.com>
> > Date: Thu, 20 Jun 2019 20:51:08 +0900
> >
> > > __vxlan_dev_create() destroys FDB using specific pointer which indicates
> > > a fdb when error occurs.
> > > But that pointer should not be used when register_netdevice() fails because
> > > register_netdevice() internally destroys fdb when error occurs.
> > >
> > > In order to avoid un-registered dev's notification, fdb destroying routine
> > > checks dev's register status before notification.
> >
> > Simply pass do_notify as false in this failure code path of __vxlan_dev_create(),
> > thank you.
>
> Failure path of __vxlan_dev_create() can't handle do_notify in that case
> because if register_netdevice() fails it internally calls
> ->ndo_uninit() which is
> vxlan_uninit().
> vxlan_uninit() internally calls vxlan_fdb_delete_default() and it callls
> vxlan_fdb_destroy().
> do_notify of vxlan_fdb_destroy() in vxlan_fdb_delete_default() is always true.
> So, failure path of __vxlan_dev_create() doesn't have any opportunity to
> handle do_notify.
I don't see register_netdevice calling ndo_uninit in case of all
errors. In the case where it does not,
does your patch leak the fdb entry ?.
Wondering if we should just use vxlan_fdb_delete_default with a notify
flag to delete the entry if exists.
Will that help ?
There is another commit that touched this code path:
commit 6db9246871394b3a136cd52001a0763676563840
Author: Petr Machata <petrm@mellanox.com>
Date: Tue Dec 18 13:16:00 2018 +0000
vxlan: Fix error path in __vxlan_dev_create()
next prev parent reply other threads:[~2019-06-25 4:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-20 11:51 [PATCH net] vxlan: do not destroy fdb if register_netdevice() is failed Taehee Yoo
2019-06-23 18:07 ` David Miller
2019-06-24 2:18 ` Taehee Yoo
2019-06-25 4:12 ` Roopa Prabhu [this message]
2019-06-25 16:08 ` Taehee Yoo
2019-06-26 5:03 ` Roopa Prabhu
2019-06-26 14:53 ` Taehee Yoo
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