[PATCH 1/2] drm/i2c/ch7006: Add a check to prevent NULL pointer dereference

[Zhang Zekun]

drm_mode_duplicate() could return NULL due to lack of memory,
which will then call NULL pointer dereference. Add a check to
prevent it.

Fixes: 6ee738610f41 ("drm/nouveau: Add DRM driver for NVIDIA GPUs")
Signed-off-by: Zhang Zekun <zhangzeku...@huawei.com>
---
 drivers/gpu/drm/i2c/ch7006_drv.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i2c/ch7006_drv.c b/drivers/gpu/drm/i2c/ch7006_drv.c
index 131512a5f3bd..a2942f497c60 100644
--- a/drivers/gpu/drm/i2c/ch7006_drv.c
+++ b/drivers/gpu/drm/i2c/ch7006_drv.c
@@ -232,12 +232,16 @@ static int ch7006_encoder_get_modes(struct drm_encoder 
*encoder,
        int n = 0;
 
        for (mode = ch7006_modes; mode->mode.clock; mode++) {
+               struct drm_display_mode *new_mode;
+
                if (~mode->valid_scales & 1<<priv->scale ||
                    ~mode->valid_norms & 1<<priv->norm)
                        continue;
 
-               drm_mode_probed_add(connector,
-                               drm_mode_duplicate(encoder->dev, &mode->mode));
+               new_mode = drm_mode_duplicate(encoder->dev, &mode->mode);
+               if (!new_mode)
+                       continue;
+               drm_mode_probed_add(connector, new_mode);
 
                n++;
        }
-- 
2.17.1