netdev - Re: [PATCH net] vxlan: do not destroy fdb if register

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 24 Jun 2019 11:18:08 +0900
From:   Taehee Yoo <ap420073@...il.com>
To:     David Miller <davem@...emloft.net>
Cc:     Netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH net] vxlan: do not destroy fdb if register_netdevice() is failed

On Mon, 24 Jun 2019 at 03:07, David Miller <davem@...emloft.net> wrote:
>

Hi David,

Thank you for the review!

> From: Taehee Yoo <ap420073@...il.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.

Thank you!