Re: [PATCH v2] media: mdp3: Fix resource leak in a for_each_child_of_node() loop

[AngeloGioacchino Del Regno]

Il 20/07/23 14:19, Lu Hongfei ha scritto:
> On 2023/7/20 15:51, AngeloGioacchino Del Regno wrote:
> > [Some people who received this message don't often get email from
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> >
> > Il 20/07/23 08:23, Lu Hongfei ha scritto:
> > > for_each_child_of_node should have of_node_put()
> > > in error path avoid resource leaks.
> > >
> > > Signed-off-by: Lu Hongfei <luhongfei@xxxxxxxx>
> > > ---
> > > Changelog:
> > > v1->v2:
> > > 1. Change the subject line of this patch to include driver name.
> > > 2. Remove the unneeded of_node_put.
> > >
> > >    drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c | 1 +
> > >    1 file changed, 1 insertion(+)
> > >
> > > diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
> > > b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
> > > index a605e80c7dc3..40c4b79a5090 100644
> > > --- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
> > > +++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
> > > @@ -1135,6 +1135,7 @@ int mdp_comp_config(struct mdp_dev *mdp)
> > >                comp = mdp_comp_create(mdp, node, id);
> > >                if (IS_ERR(comp)) {
> > >                        ret = PTR_ERR(comp);
> > > +                     of_node_put(node);
> > >                        goto err_init_comps;
> > >                }
> >
> > In case mdp_comp_sub_create() fails, we still want to decrease the
> > refcount
> > of `node`....
> >
> > ...so, just call of_node_put(node) just once, at the err_init_comps
> > label.
> >
> > err_init_comps:
> >         mdp_comp_destroy(mdp);
> >         of_node_put(node);
> >         return ret;
> >
> > Regards,
> > Angelo
>
> mdp_comp_sub_create() executes after for_each_child_of_node loop ends.
>
> The for_each_child_of_node loop ended, node == NULL and there is nothing
> to put.
>
> So I don't think it's necessary to decrease the refcount of `node` again
> when
>
> mdp_comp_sub_create() fails.
>
> Or you could further explain the reason for doing so.

You're right. My bad.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>