# \[PATCH 4.9 132/207\] drm/plane-helper: fix uninitialized variable reference

- From: Greg Kroah-Hartman \<gregkh@linuxfoundation.org\>
- Date: 2021-11-24 12:23:29 
- List: stable
- Page: https://ratatoskr.run/stable/2021/11/1584069
- Thread: https://ratatoskr.run/stable/2021/11/1583929/t/2.md

```text
From: Alex Xu (Hello71) <redacted>

[ Upstream commit 7be28bd73f23e53d6e7f5fe891ba9503fc0c7210 ]

drivers/gpu/drm/drm_plane_helper.c: In function 'drm_primary_helper_update':
drivers/gpu/drm/drm_plane_helper.c:113:32: error: 'visible' is used uninitialized [-Werror=uninitialized]
  113 |         struct drm_plane_state plane_state = {
      |                                ^~~~~~~~~~~
drivers/gpu/drm/drm_plane_helper.c:178:14: note: 'visible' was declared here
  178 |         bool visible;
      |              ^~~~~~~
cc1: all warnings being treated as errors

visible is an output, not an input. in practice this use might turn out
OK but it's still UB.

Fixes: df86af9133b4 ("drm/plane-helper: Add drm_plane_helper_check_state()")
Reviewed-by: Simon Ser <redacted>
Signed-off-by: Alex Xu (Hello71) <redacted>
Signed-off-by: Simon Ser <redacted>
Link: https://patchwork.freedesktop.org/patch/msgid/20211007063706.305984-1-alex_y_xu@yahoo.ca
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/drm_plane_helper.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c
index 7899fc1dcdb08..c4fd742ff917a 100644
--- a/drivers/gpu/drm/drm_plane_helper.c
+++ b/drivers/gpu/drm/drm_plane_helper.c
@@ -246,7 +246,6 @@ int drm_plane_helper_check_update(struct drm_plane *plane,
 		.crtc_w = drm_rect_width(dst),
 		.crtc_h = drm_rect_height(dst),
 		.rotation = rotation,
-		.visible = *visible,
 	};
 	int ret;
 
-- 
2.33.0



```
