linux-kernel - Re: [PATCH net-next v1 1/1] net: bridge: ensure that link-local traffic cannot unlock a locked port

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Date:   Sun, 24 Jul 2022 10:09:11 +0200
From:   Hans S <schultz.hans@...il.com>
To:     Vladimir Oltean <olteanv@...il.com>
Cc:     Ido Schimmel <idosch@...dia.com>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>, netdev@...r.kernel.org,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Paolo Abeni <pabeni@...hat.com>, Jiri Pirko <jiri@...nulli.us>,
        Ivan Vecera <ivecera@...hat.com>,
        Roopa Prabhu <roopa@...dia.com>,
        Nikolay Aleksandrov <razor@...ckwall.org>,
        Shuah Khan <shuah@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Hans Schultz <schultz.hans+netdev@...il.com>,
        linux-kernel@...r.kernel.org, bridge@...ts.linux-foundation.org,
        linux-kselftest@...r.kernel.org
Subject: Re: [PATCH net-next v1 1/1] net: bridge: ensure that link-local
 traffic cannot unlock a locked port

On Thu, Jul 21, 2022 at 1:45 PM Vladimir Oltean <olteanv@...il.com> wrote:
>
> On Sun, Jul 17, 2022 at 09:20:57PM +0200, Hans S wrote:
>
> I'm only pointing out the obvious here, we need an opt in for MAB, and
> the implemented behavior I've seen here kind of points to mapping this
> to "+learning +locked", where the learning process creates locked FDB entries.

I can go with the reasoning for the opt in for MAB, but disabling link
local learning system wide I don't think is a good idea, unless
someone can ensure me that it does not impact something else.
In general locked ports should never learn from link local, which is a
problem if they do, which suggests to me that this patch should
eventually be accepted as the best solution.