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

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 <redacted>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
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@cambiumnetworks.com/
Link to v2 (mis-threaded): https://lore.kernel.org/netdev/20260505085840.352206-1-shitalkumar.gandhi@cambiumnetworks.com/

 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

On Tue, May 05, 2026 at 06:02:36PM +0530, Shitalkumar Gandhi wrote:

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 <redacted>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Hi Shitalkumar,

Thanks for your work.

On 2026-05-05 18:02:36 +0530, Shitalkumar Gandhi wrote:

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 <redacted>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

-- 
Kind Regards,
Niklas Söderlund

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski [off-list ref]:

On Tue,  5 May 2026 18:02:36 +0530 you wrote:

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 <redacted>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

[...]

Here is the summary with links:
  - [net,v2] net: rtsn: fix mdio_node leak in rtsn_mdio_alloc()
    https://git.kernel.org/netdev/net/c/701ea57feaab

You are awesome, thank you!
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