Re: [PATCH] media: rzg2l-cru: Fix possible ERR_PTR deference

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Sun, Feb 08, 2026 at 02:07:48PM +0300, Alper Ak wrote:
> > Have you seen this happening ?
> 
> No, I haven't seen this happen in practice. This was reported by
> static analysis tool. Since the function explicitly documents these
> error cases, it seemed appropriate to add defensive error checking to
> avoid potential ERR_PTR dereference.

It's a false positive, this can't happen in practice due to the
MEDIA_PAD_FL_MUST_CONNECT flag being set on the RZG2L_CRU_IP_SINK pad.

In the future, please disclose usage of static analysis tools when you
submit patches.

> Laurent Pinchart, 8 Şub 2026 Paz, 00:27 tarihinde şunu yazdı:
> > On Sat, Feb 07, 2026 at 12:48:39PM +0300, Alper Ak wrote:
> > > The media_pad_remote_pad_unique() can return ERR_PTR() on failure
> > > (-ENOTUNIQ or -ENOLINK), but the code was dereferencing the return
> > > value without checking for errors. Add IS_ERR() check before
> > > dereferencing the pointer.
> >
> > Have you seen this happening ?
> >
> > > Fixes: d7d72dae81d5 ("media: rzg2l-cru: Retrieve virtual channel information")
> > > Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
> > > ---
> > >  drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c | 6 ++++++
> > >  1 file changed, 6 insertions(+)
> > >
> > > diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> > > index 162e2ace6931..a34c2188df1a 100644
> > > --- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> > > +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-video.c
> > > @@ -411,6 +411,12 @@ static int rzg2l_cru_get_virtual_channel(struct rzg2l_cru_dev *cru)
> > >       int ret;
> > >
> > >       remote_pad = media_pad_remote_pad_unique(&cru->ip.pads[RZG2L_CRU_IP_SINK]);
> > > +     if (IS_ERR(remote_pad)) {
> > > +             ret = PTR_ERR(remote_pad);
> > > +             dev_err(cru->dev, "Failed to get remote source pad: %d\n", ret);
> > > +             return ret;
> > > +     }
> > > +
> > >       ret = v4l2_subdev_call(cru->ip.remote, pad, get_frame_desc, remote_pad->index, &fd);
> > >       if (ret < 0 && ret != -ENOIOCTLCMD) {
> > >               dev_err(cru->dev, "get_frame_desc failed on IP remote subdev\n");

-- 
Regards,

Laurent Pinchart