MIME-Version: 1.0
References: <20230311170836.3919005-1-zyytlz.wz@163.com> <20230313171500.35400df5@kernel.org>
In-Reply-To: <20230313171500.35400df5@kernel.org>
From:   Zheng Hacker <hackerzheng666@gmail.com>
Date:   Tue, 14 Mar 2023 10:12:10 +0800
Message-ID: <CAJedcCwhAL0ZdCqVK=i4Ss_iZnWS+PNzq2juBmuqmKR0rbJ9QQ@mail.gmail.com>
Subject: Re: [PATCH v2] xirc2ps_cs: Fix use after free bug in xirc2ps_detach
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Zheng Wang <zyytlz.wz@163.com>, davem@davemloft.net,
        simon.horman@corigine.com, edumazet@google.com, pabeni@redhat.com,
        petrm@nvidia.com, thomas.lendacky@amd.com,
        wsa+renesas@sang-engineering.com, leon@kernel.org,
        shayagr@amazon.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, 1395428693sheep@gmail.com,
        alex000young@gmail.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Jakub Kicinski <kuba@kernel.org> =E4=BA=8E2023=E5=B9=B43=E6=9C=8814=E6=97=
=A5=E5=91=A8=E4=BA=8C 08:15=E5=86=99=E9=81=93=EF=BC=9A
>
> On Sun, 12 Mar 2023 01:08:36 +0800 Zheng Wang wrote:
> > In xirc2ps_probe, the local->tx_timeout_task was bounded
> > with xirc2ps_tx_timeout_task. When timeout occurs,
> > it will call xirc_tx_timeout->schedule_work to start the
> > work.
> >
> > When we call xirc2ps_detach to remove the driver, there
> > may be a sequence as follows:
> >
> > Stop responding to timeout tasks and complete scheduled
> > tasks before cleanup in xirc2ps_detach, which will fix
> > the problem.
> >
> > CPU0                  CPU1
> >
> >                     |xirc2ps_tx_timeout_task
> > xirc2ps_detach      |
> >   free_netdev       |
> >     kfree(dev);     |
> >                     |
> >                     | do_reset
> >                     |   //use dev
> >
> > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> > Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
> > ---
> > v2:
> > - fix indentation error suggested by Simon Horman,
> > and stop the timeout tasks  suggested by Yunsheng Lin
> > ---
> >  drivers/net/ethernet/xircom/xirc2ps_cs.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/xircom/xirc2ps_cs.c b/drivers/net/eth=
ernet/xircom/xirc2ps_cs.c
> > index 894e92ef415b..c77ca11d9497 100644
> > --- a/drivers/net/ethernet/xircom/xirc2ps_cs.c
> > +++ b/drivers/net/ethernet/xircom/xirc2ps_cs.c
> > @@ -503,6 +503,11 @@ static void
> >  xirc2ps_detach(struct pcmcia_device *link)
> >  {
> >      struct net_device *dev =3D link->priv;
> > +             struct local_info *local =3D netdev_priv(dev);
> > +
> > +             netif_carrier_off(dev);
> > +             netif_tx_disable(dev);
> > +             cancel_work_sync(&local->tx_timeout_task);
> >
> >      dev_dbg(&link->dev, "detach\n");
> >
>
> Please fix the formatting and make sure you CC the maintainers when you
> post v3.

Hi Jakub,

Get it!

Best regards,
Zheng