drm/nouveau/dispnv04: fix null pointer dereference in nv17_tv_get_ld_modes

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@vger.kernel.org
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240625081828.2620794-1-make24@iscas.ac.cn

diff --git a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
index 9c3dc9a5bb46e51cde02ee8e93c8991beec858f6..2033214c4b7848cdf55f2def59c4ecea687f649b 100644 (file)
--- 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 *