From: Marek Behún kabel@kernel.org
stable inclusion from linux-4.19.228 commit 67d271760b037ce0806d687ee6057edc8afd4205
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[ 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 Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com Signed-off-by: Laibin Qiu qiulaibin@huawei.com --- drivers/net/phy/phy_device.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 1117355313bc..2de2cbed7c5f 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1154,6 +1154,9 @@ void phy_detach(struct phy_device *phydev) phydev->mdio.dev.driver == &genphy_driver.mdiodrv.driver) 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. @@ -1163,9 +1166,6 @@ void phy_detach(struct phy_device *phydev) put_device(&phydev->mdio.dev); if (ndev_owner != bus->owner) module_put(bus->owner); - - /* Assert the reset signal */ - phy_device_reset(phydev, 1); } EXPORT_SYMBOL(phy_detach);