From: Vladimir Oltean <vladimir.oltean@nxp.com>
To: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Andrew Lunn <andrew@lunn.ch>,
Heiner Kallweit <hkallweit1@gmail.com>,
Russell King <linux@armlinux.org.uk>,
Florian Fainelli <f.fainelli@gmail.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH net] net: phy: prevent stale pointer dereference in phy_init()
Date: Thu, 20 Jul 2023 03:02:31 +0300 [thread overview]
Message-ID: <20230720000231.1939689-1-vladimir.oltean@nxp.com> (raw)
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>
---
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
next reply other threads:[~2023-07-20 0:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-20 0:02 Vladimir Oltean [this message]
2023-07-20 20:00 ` [PATCH net] net: phy: prevent stale pointer dereference in phy_init() patchwork-bot+netdevbpf
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