[PATCH v2] net: dsa: mv88e6xxx: Fix refcount leak in mv88e6xxx_mdios_register

[PATCH v2] net: dsa: mv88e6xxx: Fix refcount leak in mv88e6xxx_mdios_register

[Miaoqian Lin]

of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.
This function missing of_node_put() in an error path.
Add missing of_node_put() to avoid refcount leak.

Fixes: a3c53be55c95 ("net: dsa: mv88e6xxx: Support multiple MDIO busses")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
changes in v2:
- Add Fixes tag.
v1 link: https://lore.kernel.org/r/20220526083748.39816-1-linmq006@gmail.com/
---
 drivers/net/dsa/mv88e6xxx/chip.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 5d2c57a7c708..0726df6aeb1f 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -3960,8 +3960,10 @@ static int mv88e6xxx_mdios_register(struct mv88e6xxx_chip *chip,
 	 */
 	child = of_get_child_by_name(np, "mdio");
 	err = mv88e6xxx_mdio_register(chip, child, false);
-	if (err)
+	if (err) {
+		of_node_put(child);
 		return err;
+	}
 
 	/* Walk the device tree, and see if there are any other nodes
 	 * which say they are compatible with the external mdio
-- 
2.25.1

Re: [PATCH v2] net: dsa: mv88e6xxx: Fix refcount leak in mv88e6xxx_mdios_register

[Andrew Lunn]

On Thu, May 26, 2022 at 03:24:15PM +0400, Miaoqian Lin wrote:
> of_get_child_by_name() returns a node pointer with refcount
> incremented, we should use of_node_put() on it when done.
> This function missing of_node_put() in an error path.
> Add missing of_node_put() to avoid refcount leak.

What about releasing the reference on the non error case?
Where is that.

     Andrew