[PATCH] tvnv17.c: Adding a NULL pointer check.

[Andrey Shumilin]

It is possible to dereference a null pointer if drm_mode_duplicate() returns NULL.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Andrey Shumilin <shum.sdl at nppct.ru>
---
 drivers/gpu/drm/nouveau/dispnv04/tvnv17.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
index 670c9739e5e1..1f0c5f4a5fd2 100644
--- a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
+++ b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
@@ -209,7 +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 == NULL)
+			continue;
 		mode->clock = tv_norm->tv_enc_mode.vrefresh *
 			mode->htotal / 1000 *
 			mode->vtotal / 1000;
@@ -258,6 +259,8 @@ static int nv17_tv_get_hd_modes(struct drm_encoder *encoder,
 		if (modes[i].hdisplay == output_mode->hdisplay &&
 		    modes[i].vdisplay == output_mode->vdisplay) {
 			mode = drm_mode_duplicate(encoder->dev, output_mode);
+			if (mode == NULL)
+				continue;
 			mode->type |= DRM_MODE_TYPE_PREFERRED;
 
 		} else {
-- 
2.30.2