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From:   Zheng Hacker <hackerzheng666@gmail.com>
Date:   Wed, 15 Mar 2023 16:58:45 +0800
Message-ID: <CAJedcCwuH7eus+bVBvyDJOriPVgSp1UPjvXXjb9szy7C5t5h-A@mail.gmail.com>
Subject: Re: [PATCH net] net: ethernet: fix use after free bug in
 ns83820_remove_one due to race condition
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Zheng Wang <zyytlz.wz@163.com>, davem@davemloft.net,
        edumazet@google.com, pabeni@redhat.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, 1395428693sheep@gmail.com,
        alex000young@gmail.com
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Jakub Kicinski <kuba@kernel.org> =E4=BA=8E2023=E5=B9=B43=E6=9C=8815=E6=97=
=A5=E5=91=A8=E4=B8=89 12:10=E5=86=99=E9=81=93=EF=BC=9A
>
> On Tue, 14 Mar 2023 09:59:09 +0800 Zheng Hacker wrote:
> > Jakub Kicinski <kuba@kernel.org> =E4=BA=8E2023=E5=B9=B43=E6=9C=8814=E6=
=97=A5=E5=91=A8=E4=BA=8C 07:26=E5=86=99=E9=81=93=EF=BC=9A
> > > 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