Re: [PATCH can v1 1/2] can: j1939: use netdevice_tracker for j1939_{priv,session,ecu} tracking

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Tue, Jul 28, 2026 at 06:13:38AM +0000, sashiko-bot@kernel.org wrote:
> --- Patch [1]: [PATCH can v1 1/2] can: j1939: use netdevice_tracker for j1939_{priv,session,ecu} tracking ---
> commit fa6ae711cbc8e468a294fc1a54de5efa19c0b5b3
> Author: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> 
> can: j1939: use netdevice_tracker for j1939_{priv,session,ecu} tracking
>     
> This patch enables netdevice_tracker for j1939_priv, j1939_session, and
> j1939_ecu structures. It aims to help identify the source of refcount
> leaks reported by syzbot during unregister_netdevice().
> 
> > diff --git a/net/can/j1939/bus.c b/net/can/j1939/bus.c
> > index dc374286eeb6e..cdc3c0a719379 100644
> > --- a/net/can/j1939/bus.c
> > +++ b/net/can/j1939/bus.c
> > @@ -20,6 +20,7 @@ static void __j1939_ecu_release(struct kref *kref)
> >  	struct j1939_priv *priv = ecu->priv;
> >  
> >  	list_del(&ecu->list);
> 
> [Severity: High]
> This is a pre-existing issue, but is it safe to modify priv->ecus here without
> holding priv->lock?
> 
> If a process unbinds a socket and drops its ECU reference concurrently with the
> network receive path processing a packet:

Ack - we will keep it mind. This is not blocker for current patch set.

Best Regards,
Oleksij
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