[PATCH v3] media: v4l2-core: Drop manual fwnode_handle_put() via scope-based cleanup

[PATCH v3] media: v4l2-core: Drop manual fwnode_handle_put() via scope-based cleanup

[Biren Pandya]

Simplify v4l2_subdev_get_fwnode_pad_1_to_1() by converting the local
fwnode variable to use the __free(fwnode_handle) scope-based cleanup
macro.

This removes the need for manual fwnode_handle_put() calls and naturally
ensures the fwnode reference is held during the device_match_fwnode()
comparison.

Signed-off-by: Biren Pandya <birenpandya@gmail.com>
---
Changes in v3:
- Resend as a standalone patch to resolve Media CI robot grouping error caused by duplicate Message-IDs in the v2 thread. No code changes.
- Link to v2: https://lore.kernel.org/all/20260616162208.56488-2-birenpandya@gmail.com/

Changes in v2:
- Updated the commit message to remove the "Use-After-Free" language,
  as there is no vulnerability in practice.
- Adjusted the implementation to declare `struct fwnode_handle *fwnode`
  directly at the point of initialization, rather than at the top of the
  block, conforming to recommended usage.
- Renamed the patch subject to better reflect the true nature of the change.
- Link to v1: https://lore.kernel.org/all/20260616092516.46339-1-birenpandya@gmail.com/

 drivers/media/v4l2-core/v4l2-subdev.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index e6b133ef7850..806b059410ce 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1243,15 +1243,14 @@ const struct v4l2_file_operations v4l2_subdev_fops = {
 int v4l2_subdev_get_fwnode_pad_1_to_1(struct media_entity *entity,
 				      struct fwnode_endpoint *endpoint)
 {
-	struct fwnode_handle *fwnode;
+	struct fwnode_handle *fwnode __free(fwnode_handle) =
+		fwnode_graph_get_port_parent(endpoint->local_fwnode);
 	struct v4l2_subdev *sd;
 
 	if (!is_media_entity_v4l2_subdev(entity))
 		return -EINVAL;
 
 	sd = media_entity_to_v4l2_subdev(entity);
 
-	fwnode = fwnode_graph_get_port_parent(endpoint->local_fwnode);
-	fwnode_handle_put(fwnode);
 
 	if (device_match_fwnode(sd->dev, fwnode))
 		return endpoint->port;
 
-- 
2.50.1 (Apple Git-155)