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

Daniel Golle
2026-04-17T18:04:27Z

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.