Re: [PATCH] media: mtk-vcodec: Fix reference count leak in mtk_vcodec_fw_scp_init

[Nicolas Dufresne]

Le mercredi 02 avril 2025 à 11:37 -0400, Nicolas Dufresne a écrit :
> Hi,
> 
> Le mardi 18 mars 2025 à 19:05 +0800, Miaoqian Lin a écrit :
> > scp_get() returns a reference that needs to be released with scp_put().
> > Add missing scp_put() before returning error in mtk_vcodec_fw_scp_init().
> > 
> > Fixes: 53dbe0850444 ("media: mtk-vcodec: potential null pointer deference in SCP")
> > Signed-off-by: Miaoqian Lin <linmq006@xxxxxxxxx>
> > ---
> >  .../platform/mediatek/vcodec/common/mtk_vcodec_fw_scp.c      | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_scp.c b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_scp.c
> > index ff23b225db70..11ab3bc60217 100644
> > --- a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_scp.c
> > +++ b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_scp.c
> > @@ -71,7 +71,6 @@ struct mtk_vcodec_fw *mtk_vcodec_fw_scp_init(void *priv, enum mtk_vcodec_fw_use
> >  		pr_err("Invalid fw_use %d (use a reasonable fw id here)\n", fw_use);
> >  		return ERR_PTR(-EINVAL);
> >  	}
> > -
> 
> Might sound nit-picky, but don't do style fixes in patches intended for
> backports. It increases the chance of conflicts.
> 
> >  	scp = scp_get(plat_dev);
> >  	if (!scp) {
> >  		dev_err(&plat_dev->dev, "could not get vdec scp handle");
> > @@ -79,8 +78,10 @@ struct mtk_vcodec_fw *mtk_vcodec_fw_scp_init(void *priv, enum mtk_vcodec_fw_use
> >  	}
> >  
> >  	fw = devm_kzalloc(&plat_dev->dev, sizeof(*fw), GFP_KERNEL);
> > -	if (!fw)
> > +	if (!fw) {
> > +		scp_put(scp);
> >  		return ERR_PTR(-ENOMEM);
> > +	}
> 
> With the above style change removed:
> 
> Reviewed-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxxx>

Sorry for the noise, I see that Hans fixed and merged it already.

Nicolas

> 
> >  	fw->type = SCP;
> >  	fw->ops = &mtk_vcodec_rproc_msg;
> >  	fw->scp = scp;