[PATCH net v2] net: rtsn: fix mdio_node leak in rtsn_mdio_alloc()

From: Shitalkumar Gandhi

Date: Tue May 05 2026 - 08:33:31 EST


of_get_child_by_name() takes a reference. The rtsn_reset() and
rtsn_change_mode() failure paths jump to out_free_bus and leak
mdio_node.

Add out_put_node to drop it before falling through.

Fixes: b0d3969d2b4d ("net: ethernet: rtsn: Add support for Renesas Ethernet-TSN")
Signed-off-by: Shitalkumar Gandhi <shitalkumar.gandhi@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
Changes in v2:
- Restore blank line between `return 0;` and `out_put_node:` label (Geert)
- Add Reviewed-by: Geert Uytterhoeven

Resent as a new thread (no code changes) so netdev CI picks it up
(Andrew).

Link to v1: https://lore.kernel.org/netdev/20260504200356.3529873-1-shitalkumar.gandhi@xxxxxxxxxxxxxxxxxxx/
Link to v2 (mis-threaded): https://lore.kernel.org/netdev/20260505085840.352206-1-shitalkumar.gandhi@xxxxxxxxxxxxxxxxxxx/

drivers/net/ethernet/renesas/rtsn.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/renesas/rtsn.c b/drivers/net/ethernet/renesas/rtsn.c
index 03a2669f0518..ee8381b60b8d 100644
--- a/drivers/net/ethernet/renesas/rtsn.c
+++ b/drivers/net/ethernet/renesas/rtsn.c
@@ -797,11 +797,11 @@ static int rtsn_mdio_alloc(struct rtsn_private *priv)
/* Enter config mode before registering the MDIO bus */
ret = rtsn_reset(priv);
if (ret)
- goto out_free_bus;
+ goto out_put_node;

ret = rtsn_change_mode(priv, OCR_OPC_CONFIG);
if (ret)
- goto out_free_bus;
+ goto out_put_node;

rtsn_modify(priv, MPIC, MPIC_PSMCS_MASK | MPIC_PSMHT_MASK,
MPIC_PSMCS_DEFAULT | MPIC_PSMHT_DEFAULT);
@@ -824,6 +824,8 @@ static int rtsn_mdio_alloc(struct rtsn_private *priv)

return 0;

+out_put_node:
+ of_node_put(mdio_node);
out_free_bus:
mdiobus_free(mii);
return ret;
--
2.25.1