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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Fri, 13 Oct 2023 09:43:05 -0400
Message-ID: <CADnq5_P4i2J2AaO2R6rMO0nvRGZNT1EUN1jDUB2mC4BkHKOecg@mail.gmail.com>
Subject: Re: [PATCH] drm/amdgpu/vkms: fix a possible null pointer dereference
To:     Ma Ke <make_ruc2021@163.com>
Cc:     alexander.deucher@amd.com, christian.koenig@amd.com,
        Xinhui.Pan@amd.com, airlied@gmail.com, daniel@ffwll.ch,
        guchun.chen@amd.com, yifan1.zhang@amd.com, Tim.Huang@amd.com,
        zackr@vmware.com, dri-devel@lists.freedesktop.org,
        amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
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On Thu, Oct 12, 2023 at 10:32=E2=80=AFPM Ma Ke <make_ruc2021@163.com> wrote=
:
>
> In amdgpu_vkms_conn_get_modes(), the return value of drm_cvt_mode()
> is assigned to mode, which will lead to a NULL pointer dereference
> on failure of drm_cvt_mode(). Add a check to avoid null pointer
> dereference.
>
> Signed-off-by: Ma Ke <make_ruc2021@163.com>

Applied.  Thanks!

Alex

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/a=
md/amdgpu/amdgpu_vkms.c
> index 7148a216ae2f..db6fc0cb18eb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
> @@ -239,6 +239,8 @@ static int amdgpu_vkms_conn_get_modes(struct drm_conn=
ector *connector)
>
>         for (i =3D 0; i < ARRAY_SIZE(common_modes); i++) {
>                 mode =3D drm_cvt_mode(dev, common_modes[i].w, common_mode=
s[i].h, 60, false, false, false);
> +               if (!mode)
> +                       continue;
>                 drm_mode_probed_add(connector, mode);
>         }
>
> --
> 2.37.2
>