Re: [PATCH net] net: dsa: mt7530: fix .get_stats64 sleeping in atomic context

[Daniel Golle <daniel@makrotopia.org>]

On Fri, Apr 17, 2026 at 10:46:29AM -0700, Breno Leitao wrote:
> On Fri, Apr 17, 2026 at 04:55:57AM +0100, Daniel Golle wrote:
> > @@ -3404,6 +3449,9 @@ EXPORT_SYMBOL_GPL(mt7530_probe_common);
> >  void
> >  mt7530_remove_common(struct mt7530_priv *priv)
> >  {
> > +	if (priv->bus)
> > +		cancel_delayed_work_sync(&priv->stats_work);
> > +
> 
> Shouldn't you cancel the work later, after dsa_unregister_switch()?
> 
> I am wondering if the following race cannot happen:
> 
>  mt7530_remove_common()                  someone reading /proc/net/dev
>     cancel_delayed_work_sync()
>       /* returns: work neither pending
>          nor executing - true at this
>          instant */
>                                           mt7530_get_stats64()
>                                             mod_delayed_work(...)
>                                             /* work is queued again */
>     dsa_unregister_switch()
>     return

Thanks you for pointing this out.
cancel_delayed_work_sync() should be moved after dsa_unregister_switch()
to avoid this kind of race.