From: Florian Fainelli f.fainelli@gmail.com
[ Upstream commit c2b727df7caa33876e7066bde090f40001b6d643 ]
If we have unbound the PHY driver prior to calling phy_detach() (often via phy_disconnect()) then we can cause a NULL pointer de-reference accessing the driver owner member. The steps to reproduce are:
echo unimac-mdio-0:01 > /sys/class/net/eth0/phydev/driver/unbind ip link set eth0 down
Fixes: cafe8df8b9bc ("net: phy: Fix lack of reference count on PHY driver") Signed-off-by: Florian Fainelli f.fainelli@gmail.com Reviewed-by: Andrew Lunn andrew@lunn.ch Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/phy/phy_device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1421,7 +1421,8 @@ void phy_detach(struct phy_device *phyde
phy_led_triggers_unregister(phydev);
- module_put(phydev->mdio.dev.driver->owner); + if (phydev->mdio.dev.driver) + module_put(phydev->mdio.dev.driver->owner);
/* If the device had no specific driver before (i.e. - it * was using the generic driver), we unbind the device