From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Thu, 20 Jul 2023 03:02:31 +0300
Subject: [PATCH] net: phy: prevent stale pointer dereference in phy_init()
References: bsc#1012628
Patch-mainline: 6.4.7
Git-commit: 1c613beaf877c0c0d755853dc62687e2013e55c4
[ Upstream commit 1c613beaf877c0c0d755853dc62687e2013e55c4 ]
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/
Suggested-by: Russell King (Oracle) <linux@armlinux.org.uk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230720000231.1939689-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
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 53598210..2c4e6de8 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -3452,23 +3452,30 @@ 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;
}
--
2.35.3