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References: <20220109184245.124850-1-jose.exposito89@gmail.com> <139784cd-6cb7-18e0-bb09-b35113bd83ef@amd.com>
In-Reply-To: <139784cd-6cb7-18e0-bb09-b35113bd83ef@amd.com>
From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Mon, 10 Jan 2022 13:37:34 -0500
Message-ID: <CADnq5_N1-kKfhZ9mttcRq7RON0DsEjs1cpvxo4M7jJN3M8Sx9w@mail.gmail.com>
Subject: Re: [PATCH] drm/amd/display: invalid parameter check in dmub_hpd_callback
To:     Harry Wentland <harry.wentland@amd.com>
Cc:     =?UTF-8?B?Sm9zw6kgRXhww7NzaXRv?= <jose.exposito89@gmail.com>,
        Jude Shih <shenshih@amd.com>,
        Anson Jacob <Anson.Jacob@amd.com>,
        "Leo (Sunpeng) Li" <sunpeng.li@amd.com>,
        xinhui pan <Xinhui.Pan@amd.com>,
        "Siqueira, Rodrigo" <Rodrigo.Siqueira@amd.com>,
        LKML <linux-kernel@vger.kernel.org>,
        amd-gfx list <amd-gfx@lists.freedesktop.org>,
        "Kazlauskas, Nicholas" <nicholas.kazlauskas@amd.com>,
        Dave Airlie <airlied@linux.ie>,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>, Daniel Vetter <daniel@ffwll.ch>,
        "Deucher, Alexander" <alexander.deucher@amd.com>,
        Christian Koenig <christian.koenig@amd.com>
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Precedence: bulk

Applied.  Thanks!

Alex

On Mon, Jan 10, 2022 at 11:34 AM Harry Wentland <harry.wentland@amd.com> wr=
ote:
>
> On 2022-01-09 13:42, Jos=C3=A9 Exp=C3=B3sito wrote:
> > The function performs a check on the "adev" input parameter, however, i=
t
> > is used before the check.
> >
> > Initialize the "dev" variable after the sanity check to avoid a possibl=
e
> > NULL pointer dereference.
> >
> > Fixes: e27c41d5b0681 ("drm/amd/display: Support for DMUB HPD interrupt =
handling")
> > Addresses-Coverity-ID: 1493909 ("Null pointer dereference")
> > Signed-off-by: Jos=C3=A9 Exp=C3=B3sito <jose.exposito89@gmail.com>
>
> Reviewed-by: Harry Wentland <harry.wentland@amd.com>
>
> Harry
>
> > ---
> >  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/driver=
s/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > index e727f1dd2a9a..7fbded7a6d9c 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > @@ -656,7 +656,7 @@ void dmub_hpd_callback(struct amdgpu_device *adev, =
struct dmub_notification *not
> >       struct drm_connector_list_iter iter;
> >       struct dc_link *link;
> >       uint8_t link_index =3D 0;
> > -     struct drm_device *dev =3D adev->dm.ddev;
> > +     struct drm_device *dev;
> >
> >       if (adev =3D=3D NULL)
> >               return;
> > @@ -673,6 +673,7 @@ void dmub_hpd_callback(struct amdgpu_device *adev, =
struct dmub_notification *not
> >
> >       link_index =3D notify->link_index;
> >       link =3D adev->dm.dc->links[link_index];
> > +     dev =3D adev->dm.ddev;
> >
> >       drm_connector_list_iter_begin(dev, &iter);
> >       drm_for_each_connector_iter(connector, &iter) {
>