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From:   Navid Emamdoost <navid.emamdoost@gmail.com>
Date:   Sat, 12 Oct 2019 14:22:18 -0500
Message-ID: <CAEkB2EQUrHpfCXDQ9HV9_hw7Ke5DmX3SvKWJd+wSwXB1Uqaf5g@mail.gmail.com>
Subject: Re: [PATCH] drm/imx: fix memory leak in imx_pd_bind
To:     Markus Elfring <Markus.Elfring@web.de>
Cc:     dri-devel@lists.freedesktop.org,
        linux-arm-kernel@lists.infradead.org,
        NXP Linux Team <linux-imx@nxp.com>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Navid Emamdoost <emamd001@umn.edu>, Kangjie Lu <kjlu@umn.edu>,
        Stephen McCamant <smccaman@umn.edu>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Fabio Estevam <festevam@gmail.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Shawn Guo <shawnguo@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        kernel-janitors@vger.kernel.org
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No, that is not correct! You should not try to free imxpd here as it
is a resource-managed allocation via devm_kzalloc(). It means memory
allocated with this function is automatically freed on driver detach.
So, this patch introduces a double-free.

On Sat, Oct 12, 2019 at 6:54 AM Markus Elfring <Markus.Elfring@web.de> wrot=
e:
>
> > +free_edid:
> > +     kfree(imxpd->edid);
> > +     return ret;
>
> I have taken another look at this change idea.
> Can the function call =E2=80=9Cdevm_kfree(dev, imxpd)=E2=80=9D become rel=
evant
> also at this place?
>
> Would you like to combine it with the update suggestion
> =E2=80=9CFix error handling for a kmemdup() call in imx_pd_bind()=E2=80=
=9D?
> https://lore.kernel.org/r/3fd6aa8b-2529-7ff5-3e19-05267101b2a4@web.de/
> https://lore.kernel.org/patchwork/patch/1138912/
> https://lkml.org/lkml/2019/10/12/87
>
> Regards,
> Markus


--=20
Navid.