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From:   Nicolas Boichat <drinkcat@chromium.org>
Date:   Thu, 3 Sep 2020 08:08:00 +0800
Message-ID: <CANMq1KDcYRKWxQ6+AQ=eTRcHdkiWyzH7BTahXdag5=FdnF7e1g@mail.gmail.com>
Subject: Re: [PATCH v2] rpmsg: Avoid double-free in mtk_rpmsg_register_device
To:     Mathieu Poirier <mathieu.poirier@linaro.org>
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Ohad Ben-Cohen <ohad@wizery.com>,
        Pi-Hsun Shih <pihsun@chromium.org>,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        lkml <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        "open list:REMOTE PROCESSOR (REMOTEPROC) SUBSYSTEM" 
        <linux-remoteproc@vger.kernel.org>
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On Thu, Sep 3, 2020 at 12:55 AM Mathieu Poirier
<mathieu.poirier@linaro.org> wrote:
>
> On Wed, Sep 02, 2020 at 07:07:15PM +0800, Nicolas Boichat wrote:
> > If rpmsg_register_device fails, it will call
> > mtk_rpmsg_release_device which already frees mdev.
> >
> > Fixes: 7017996951fde84 ("rpmsg: add rpmsg support for mt8183 SCP.")
>
> The SHA should be 12 characters instead of 15.  With that:

Done in v3, thanks (and fixed my process for next time).

> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>
> > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
> > ---
> >
> > Changes in v2:
> >  - Drop useless if and ret variable (Markus Elfring)
> >
> >  drivers/rpmsg/mtk_rpmsg.c | 9 +--------
> >  1 file changed, 1 insertion(+), 8 deletions(-)
> >
> > diff --git a/drivers/rpmsg/mtk_rpmsg.c b/drivers/rpmsg/mtk_rpmsg.c
> > index 83f2b8804ee989d..96a17ec2914011d 100644
> > --- a/drivers/rpmsg/mtk_rpmsg.c
> > +++ b/drivers/rpmsg/mtk_rpmsg.c
> > @@ -200,7 +200,6 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
> >       struct rpmsg_device *rpdev;
> >       struct mtk_rpmsg_device *mdev;
> >       struct platform_device *pdev = mtk_subdev->pdev;
> > -     int ret;
> >
> >       mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
> >       if (!mdev)
> > @@ -219,13 +218,7 @@ static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev,
> >       rpdev->dev.parent = &pdev->dev;
> >       rpdev->dev.release = mtk_rpmsg_release_device;
> >
> > -     ret = rpmsg_register_device(rpdev);
> > -     if (ret) {
> > -             kfree(mdev);
> > -             return ret;
> > -     }
> > -
> > -     return 0;
> > +     return rpmsg_register_device(rpdev);
> >  }
> >
> >  static void mtk_register_device_work_function(struct work_struct *register_work)
> > --
> > 2.28.0.402.g5ffc5be6b7-goog
> >