net: mdiobus: fix an OF node reference leak

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>

diff --git a/drivers/net/mdio/fwnode_mdio.c b/drivers/net/mdio/fwnode_mdio.c
index b156493d7084156d3b2845e783af0a0f533c9cfd..aea0f03575689a57670605383544cf8ee8a25653 100644 (file)
--- a/drivers/net/mdio/fwnode_mdio.c
+++ b/drivers/net/mdio/fwnode_mdio.c
@@ -40,6 +40,7 @@ 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;
 
@@ -53,10 +54,16 @@ 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,