[PATCH net-next] net: dsa: hellcreek: fix device_node leak in hellcreek_led_setup()

[Xia Yan]

hellcreek_led_setup() walks the two LED child nodes of the "leds" node
with of_get_next_available_child(). The helper drops the reference on
the child passed to it and takes one on the child it returns. After
the second call the caller holds a reference on the second LED node.

That reference is never dropped. The out: label only releases the
"leds" node itself. Boards with both LED child nodes leak one
device_node reference per probe, on the registration failures as well
as on the success path.

Drop it at the out: label, before the parent node. The early exits,
where the walk stopped before the second child, pass NULL, which
of_node_put() ignores.

Found during a code review of the OF node handling in DSA drivers.

Signed-off-by: Xia Yan <yanxia@xxxxxxxxxxxxxxxxxxxx>
---
  drivers/net/dsa/hirschmann/hellcreek_ptp.c | 1 +
  1 file changed, 1 insertion(+)
diff --git a/drivers/net/dsa/hirschmann/hellcreek_ptp.c b/drivers/net/dsa/hirschmann/hellcreek_ptp.c
index cb23bea9c21b..ed27731d4f4e 100644
--- a/drivers/net/dsa/hirschmann/hellcreek_ptp.c
+++ b/drivers/net/dsa/hirschmann/hellcreek_ptp.c
@@ -392,6 +392,7 @@ static int hellcreek_led_setup(struct hellcreek *hellcreek)
 	ret = 0;
 
 out:
+	of_node_put(led);
 	of_node_put(leds);
 
 	return ret;