Commit 1c613bea authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
Browse files

net: phy: prevent stale pointer dereference in phy_init() 

mdio_bus_init() and phy_driver_register() both have error paths, and if
those are ever hit, ethtool will have a stale pointer to the
phy_ethtool_phy_ops stub structure, which references memory from a
module that failed to load (phylib).

It is probably hard to force an error in this code path even manually,
but the error teardown path of phy_init() should be the same as
phy_exit(), which is now simply not the case.

Fixes: 55d8f053 ("net: phy: Register ethtool PHY operations")
Link: https://lore.kernel.org/netdev/ZLaiJ4G6TaJYGJyU@shell.armlinux.org.uk/


Suggested-by: default avatarRussell King (Oracle) <linux@armlinux.org.uk>
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230720000231.1939689-1-vladimir.oltean@nxp.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7998c0ad

drivers/net/phy/phy_device.c

+14 −7
Original line number Diff line number Diff line
@@ -3451,23 +3451,30 @@ static int __init phy_init(void) 
{

	int rc;



	ethtool_set_ethtool_phy_ops(&phy_ethtool_phy_ops);



	rc = mdio_bus_init();

	if (rc)

		return rc;

		goto err_ethtool_phy_ops;



	ethtool_set_ethtool_phy_ops(&phy_ethtool_phy_ops);

	features_init();



	rc = phy_driver_register(&genphy_c45_driver, THIS_MODULE);

	if (rc)

		goto err_c45;

		goto err_mdio_bus;



	rc = phy_driver_register(&genphy_driver, THIS_MODULE);

	if (rc) {

		phy_driver_unregister(&genphy_c45_driver);

	if (rc)

		goto err_c45;



	return 0;



err_c45:

	phy_driver_unregister(&genphy_c45_driver);

err_mdio_bus:

	mdio_bus_exit();

	}

err_ethtool_phy_ops:

	ethtool_set_ethtool_phy_ops(NULL);



	return rc;

}