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References: <20230309100248.3831498-1-zyytlz.wz@163.com> <cca0b40b-d6f8-54c7-1e46-83cb62d0a2f1@huawei.com>
In-Reply-To: <cca0b40b-d6f8-54c7-1e46-83cb62d0a2f1@huawei.com>
From:   Zheng Hacker <hackerzheng666@gmail.com>
Date:   Sat, 11 Mar 2023 00:38:10 +0800
Message-ID: <CAJedcCy2n9jHm+uS5RG1T7u8aK8RazrzrC-sQhxFQ_v_ZphjWA@mail.gmail.com>
Subject: Re: [PATCH net] net: ravb: Fix possible UAF bug in ravb_remove
To:     Yunsheng Lin <linyunsheng@huawei.com>
Cc:     Zheng Wang <zyytlz.wz@163.com>, s.shtylyov@omp.ru,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, 1395428693sheep@gmail.com,
        alex000young@gmail.com
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Yunsheng Lin <linyunsheng@huawei.com> =E4=BA=8E2023=E5=B9=B43=E6=9C=8810=E6=
=97=A5=E5=91=A8=E4=BA=94 09:12=E5=86=99=E9=81=93=EF=BC=9A
>
> On 2023/3/9 18:02, Zheng Wang wrote:
> > In ravb_probe, priv->work was bound with ravb_tx_timeout_work.
> > If timeout occurs, it will start the work. And if we call
> > ravb_remove without finishing the work, ther may be a use
>
> ther -> there
>

Sorry about the typo, will correct it in the next version.

> > after free bug on ndev.
> >
> > Fix it by finishing the job before cleanup in ravb_remove.
> >
> > Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
> > Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
> > ---
> >  drivers/net/ethernet/renesas/ravb_main.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/eth=
ernet/renesas/ravb_main.c
> > index 0f54849a3823..07a08e72f440 100644
> > --- a/drivers/net/ethernet/renesas/ravb_main.c
> > +++ b/drivers/net/ethernet/renesas/ravb_main.c
> > @@ -2892,6 +2892,7 @@ static int ravb_remove(struct platform_device *pd=
ev)
> >       struct ravb_private *priv =3D netdev_priv(ndev);
> >       const struct ravb_hw_info *info =3D priv->info;
> >
> > +     cancel_work_sync(&priv->work);
>
> As your previous patch, I still do not see anything stopping
> dev_watchdog() from calling dev->netdev_ops->ndo_tx_timeout
> after cancel_work_sync(), maybe I missed something obvious
> here?
>
Yes, that's a keyed suggestion. I was hurry to report the issue today
so wrote with many mistakes.
Thanks agagin for the advice. I will review other patch carefully.

Best regards,
Zheng

>

> >       /* Stop PTP Clock driver */
> >       if (info->ccc_gac)
> >               ravb_ptp_stop(ndev);
> >