From c2b727df7caa33876e7066bde090f40001b6d643 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Wed, 16 Sep 2020 20:43:09 -0700 Subject: [PATCH 1/2] 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(-) diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index b93b40cda54ab..5dab6be6fc383 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 From 5116a8ade333b6c2e180782139c9c516a437b21c Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Wed, 16 Sep 2020 20:43:10 -0700 Subject: [PATCH 2/2] net: phy: Do not warn in phy_stop() on PHY_DOWN When phy_is_started() was added to catch incorrect PHY states, phy_stop() would not be qualified against PHY_DOWN. It is possible to reach that state when the PHY driver has been unbound and the network device is then brought down. Fixes: 2b3e88ea6528 ("net: phy: improve phy state checking") Signed-off-by: Florian Fainelli Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/phy/phy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 735a806045ac3..8947d58f2a25f 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -996,7 +996,7 @@ void phy_stop(struct phy_device *phydev) { struct net_device *dev = phydev->attached_dev; - if (!phy_is_started(phydev)) { + if (!phy_is_started(phydev) && phydev->state != PHY_DOWN) { WARN(1, "called from state %s\n", phy_state_to_str(phydev->state)); return;