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

commit 66edf3fb331b6c55439b10f9862987b0916b3726 upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
index be28e7bd7490324c42c4551ba4d1ff835e1d0b46..f0251866e6dd975fc3f1cef62ca405422bc9c4f9 100644 (file)
--- a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
+++ b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
@@ -208,6 +208,8 @@ 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 *