Nouveau - Jun 2024 - [PATCH] drm/nouveau/dispnv04: fix null pointer dereference in nv17_tv_get_ld_modes

Reviewed-by: Lyude Paul <lyude at redhat.com>

On Tue, 2024-06-25 at 16:18 +0800, Ma Ke wrote:
> In nv17_tv_get_ld_modes(), the return value of drm_mode_duplicate()
> is
> assigned to mode, which will lead to a possible NULL pointer
> dereference
> on failure of drm_mode_duplicate(). Add a check to avoid npd.
> 
> Cc: stable at vger.kernel.org
> Signed-off-by: Ma Ke <make24 at iscas.ac.cn>
> ---
> ?drivers/gpu/drm/nouveau/dispnv04/tvnv17.c | 2 ++
> ?1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
> b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
> index 670c9739e5e1..4a08e61f3336 100644
> --- a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
> +++ b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
> @@ -209,6 +209,8 @@ static int nv17_tv_get_ld_modes(struct
> drm_encoder *encoder,
> ?		struct drm_display_mode *mode;
> ?
> ?		mode = drm_mode_duplicate(encoder->dev, tv_mode);
> +		if (!mode)
> +			continue;
> ?
> ?		mode->clock = tv_norm->tv_enc_mode.vrefresh *
> ?			mode->htotal / 1000 *
-- 
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat