phylib: fix potential use-after-free

[ Upstream commit cbda1b1 ] Commit bafbdd5 ("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: bafbdd5 ("phylib: Add device reset GPIO support") Signed-off-by: Marek Behún <[email protected]> Reviewed-by: Andrew Lunn <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
ammarfaizi2 · Jan 31, 2022 · b42fbed · b42fbed
1 parent cac874a
commit b42fbed
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
@@ -1746,6 +1746,9 @@ 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.
@@ -1757,9 +1760,6 @@ 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);