Re: [PATCH net] net: ethernet: fix use after free bug in ns83820_remove_one due to race condition

From: Zheng Hacker
Date: Wed Mar 15 2023 - 04:59:03 EST


Jakub Kicinski <kuba@xxxxxxxxxx> 于2023年3月15日周三 12:10写道:
>
> On Tue, 14 Mar 2023 09:59:09 +0800 Zheng Hacker wrote:
> > Jakub Kicinski <kuba@xxxxxxxxxx> 于2023年3月14日周二 07:26写道:
> > > On Thu, 9 Mar 2023 17:42:31 +0800 Zheng Wang wrote:
> > > > + cancel_work_sync(&dev->tq_refill);
> > > > ns83820_disable_interrupts(dev); /* paranoia */
> > > >
> > > > unregister_netdev(ndev);
> > >
> > > Canceling the work before unregister can't work.
> > > Please take a closer look, the work to refill a ring should be
> > > canceled when the ring itself is dismantled.
> >
> > Hi Jakub,
> >
> > Thanks for your review! After seeing code again, I found when handling
> > IRQ request, it will finally call ns83820_irq->ns83820_do_isr->
> > ns83820_rx_kick->schedule_work to start work. So I think we should
> > move the code after free_irq. What do you think?
>
> Sorry, we have over 300 patches which need reviews. I don't have
> the time to help you. Perhaps someone else will.
>

Hi Jakub,

Thanks for your precious and kind reminder. I'll think about it again
and write the next version of patch.

> Please make sure you work on a single networking fix at a time.
> All the patches you posted had the same issues.

Yes, I'll keep that in mind.

Best regards,
Zheng