[PATCH 6.1 31/83] net: mdiobus: fix an OF node reference leak

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>

[ Upstream commit 572af9f284669d31d9175122bbef9bc62cea8ded ]

fwnode_find_mii_timestamper() calls of_parse_phandle_with_fixed_args()
but does not decrement the refcount of the obtained OF node. Add an
of_node_put() call before returning from the function.

This bug was detected by an experimental static analysis tool that I am
developing.

Fixes: bc1bee3b87ee ("net: mdiobus: Introduce fwnode_mdiobus_register_phy()")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20241218035106.1436405-1-joe@pf.is.s.u-tokyo.ac.jp
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/mdio/fwnode_mdio.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mdio/fwnode_mdio.c b/drivers/net/mdio/fwnode_mdio.c
index b782c35c4ac1..8ada397bc357 100644
--- a/drivers/net/mdio/fwnode_mdio.c
+++ b/drivers/net/mdio/fwnode_mdio.c
@@ -38,6 +38,7 @@ fwnode_find_pse_control(struct fwnode_handle *fwnode)
 static struct mii_timestamper *
 fwnode_find_mii_timestamper(struct fwnode_handle *fwnode)
 {
+	struct mii_timestamper *mii_ts;
 	struct of_phandle_args arg;
 	int err;
 
@@ -51,10 +52,16 @@ fwnode_find_mii_timestamper(struct fwnode_handle *fwnode)
 	else if (err)
 		return ERR_PTR(err);
 
-	if (arg.args_count != 1)
-		return ERR_PTR(-EINVAL);
+	if (arg.args_count != 1) {
+		mii_ts = ERR_PTR(-EINVAL);
+		goto put_node;
+	}
+
+	mii_ts = register_mii_timestamper(arg.np, arg.args[0]);
 
-	return register_mii_timestamper(arg.np, arg.args[0]);
+put_node:
+	of_node_put(arg.np);
+	return mii_ts;
 }
 
 int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
-- 
2.39.5