[PATCH net] net: phy: prevent stale pointer dereference in phy_init()
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: 2023-07-20 00:02:49
Also in:
lkml
Subsystem:
ethernet phy library, networking drivers, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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: 55d8f053ce1b ("net: phy: Register ethtool PHY operations")
Link: https://lore.kernel.org/netdev/ZLaiJ4G6TaJYGJyU@shell.armlinux.org.uk/ (local)
Suggested-by: Russell King (Oracle) <linux@armlinux.org.uk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
drivers/net/phy/phy_device.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 0c2014accba7..61921d4dbb13 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c@@ -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: - mdio_bus_exit(); - } + phy_driver_unregister(&genphy_c45_driver); +err_mdio_bus: + mdio_bus_exit(); +err_ethtool_phy_ops: + ethtool_set_ethtool_phy_ops(NULL); return rc; }
--
2.34.1