linux-kernel - Re: [PATCH] drm/imx: fix memory leak in imx_pd

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Message-ID: <CAEkB2EQUrHpfCXDQ9HV9_hw7Ke5DmX3SvKWJd+wSwXB1Uqaf5g@mail.gmail.com>
Date:   Sat, 12 Oct 2019 14:22:18 -0500
From:   Navid Emamdoost <navid.emamdoost@...il.com>
To:     Markus Elfring <Markus.Elfring@....de>
Cc:     dri-devel@...ts.freedesktop.org,
        linux-arm-kernel@...ts.infradead.org,
        NXP Linux Team <linux-imx@....com>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Navid Emamdoost <emamd001@....edu>, Kangjie Lu <kjlu@....edu>,
        Stephen McCamant <smccaman@....edu>,
        Daniel Vetter <daniel@...ll.ch>,
        David Airlie <airlied@...ux.ie>,
        Fabio Estevam <festevam@...il.com>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Shawn Guo <shawnguo@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] drm/imx: fix memory leak in imx_pd_bind

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@....de> wrote:
>
> > +free_edid:
> > +     kfree(imxpd->edid);
> > +     return ret;
>
> I have taken another look at this change idea.
> Can the function call “devm_kfree(dev, imxpd)” become relevant
> also at this place?
>
> Would you like to combine it with the update suggestion
> “Fix error handling for a kmemdup() call in imx_pd_bind()”?
> 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



-- 
Navid.