From c2b727df7caa33876e7066bde090f40001b6d643 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Wed, 16 Sep 2020 20:43:09 -0700 Subject: net: phy: Avoid NPD upon phy_detach() when driver is unbound 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 Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/phy/phy_device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/net/phy/phy_device.c') diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index b93b40cda54a..5dab6be6fc38 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1682,7 +1682,8 @@ void phy_detach(struct phy_device *phydev) 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 -- cgit v1.2.3-70-g09d2