[PATCH] drm/of: free the iterator object on failure

[Steven Price]

When bailing out due to the sanity check the iterator value needs to be
freed because the early return prevents for_each_child_of_node() from
doing the dereference itself.

Fixes: 4ee48cc5586b ("drm: of: Fix double-free bug")
Signed-off-by: Steven Price <steven.price at arm.com>
---
 drivers/gpu/drm/drm_of.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Daniel's email[1] made me take a look at this function and it appears
that for_each_child_of_node()'s interface had caused a bad bug fix due
to the hidden reference counting in the iterator.

[1] https://lore.kernel.org/r/YOxQ5TbkNrqCGBDJ%40phenom.ffwll.local

diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
index 197c57477344..997b8827fed2 100644
--- a/drivers/gpu/drm/drm_of.c
+++ b/drivers/gpu/drm/drm_of.c
@@ -331,8 +331,10 @@ static int drm_of_lvds_get_remote_pixels_type(
 		 * configurations by passing the endpoints explicitly to
 		 * drm_of_lvds_get_dual_link_pixel_order().
 		 */
-		if (!current_pt || pixels_type != current_pt)
+		if (!current_pt || pixels_type != current_pt) {
+			of_node_put(endpoint);
 			return -EINVAL;
+		}
 	}
 
 	return pixels_type;
-- 
2.20.1