netdev - Re: [PATCH v2 net] net: bridge: annotate data-races around fdb->{updated,used}

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Message-ID: <64698c47-18a8-4dae-938c-ef8203031396@blackwall.org>
Date: Wed, 7 Jan 2026 12:43:00 +0200
From: Nikolay Aleksandrov <razor@...ckwall.org>
To: Eric Dumazet <edumazet@...gle.com>, "David S . Miller"
 <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>
Cc: Simon Horman <horms@...nel.org>, netdev@...r.kernel.org,
 eric.dumazet@...il.com, Ido Schimmel <idosch@...dia.com>
Subject: Re: [PATCH v2 net] net: bridge: annotate data-races around
 fdb->{updated,used}

On 07/01/2026 11:00, Nikolay Aleksandrov wrote:
> On 07/01/2026 10:32, Eric Dumazet wrote:
>> fdb->updated and fdb->used are read and written locklessly.
>>
>> Add READ_ONCE()/WRITE_ONCE() annotations.
>>
>> Fixes: 31cbc39b6344 ("net: bridge: add option to allow activity 
>> notifications for any fdb entries")
>> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
>> Cc: Nikolay Aleksandrov <razor@...ckwall.org>
>> ---
>> v2: annotate all problematic fdb->updated and fdb->used reads/writes.
>> v1: https://lore.kernel.org/netdev/CANn89iL8-e_jphcg49eX=zdWrOeuA- 
>> AJDL0qhsTrApA4YnOFEg@...l.gmail.com/T/ 
>> #mf99b76469697813939abe745f42ace3e201ef6f4
>>
>>   net/bridge/br_fdb.c | 28 ++++++++++++++++------------
>>   1 file changed, 16 insertions(+), 12 deletions(-)
>>
> 
> +CC Ido
> 
> Oh you took care of ->used as well, even better. Thanks!
> Acked-by: Nikolay Aleksandrov <razor@...ckwall.org>
> 

Sorry, I forgot about br_input.c: br_handle_frame_finish()
use of ->used:
...
                 if (now != dst->used)
                         dst->used = now;
...

That will need annotations as well.