diff mbox series

[5.10,074/100] phylib: fix potential use-after-free

Message ID 20220131105222.910242948@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH Jan. 31, 2022, 10:56 a.m. UTC 
From: Marek Behún <kabel@kernel.org>

[ Upstream commit cbda1b16687580d5beee38273f6241ae3725960c ]

Commit bafbdd527d56 ("phylib: Add device reset GPIO support") added call
to phy_device_reset(phydev) after the put_device() call in phy_detach().

The comment before the put_device() call says that the phydev might go
away with put_device().

Fix potential use-after-free by calling phy_device_reset() before
put_device().

Fixes: bafbdd527d56 ("phylib: Add device reset GPIO support")
Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220119162748.32418-1-kabel@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/phy/phy_device.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 85f3cde5ffd09..d2f6d8107595a 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1682,6 +1682,9 @@  void phy_detach(struct phy_device *phydev)
 	    phy_driver_is_genphy_10g(phydev))
 		device_release_driver(&phydev->mdio.dev);
 
+	/* Assert the reset signal */
+	phy_device_reset(phydev, 1);
+
 	/*
 	 * The phydev might go away on the put_device() below, so avoid
 	 * a use-after-free bug by reading the underlying bus first.
@@ -1693,9 +1696,6 @@  void phy_detach(struct phy_device *phydev)
 		ndev_owner = dev->dev.parent->driver->owner;
 	if (ndev_owner != bus->owner)
 		module_put(bus->owner);
-
-	/* Assert the reset signal */
-	phy_device_reset(phydev, 1);
 }
 EXPORT_SYMBOL(phy_detach);