From: Lukas Wunner lukas@wunner.de
[ Upstream commit d1408f6b4dd78fb1b9e26bcf64477984e5f85409 ]
Commit 2c9d6c2b871d ("usbnet: run unbind() before unregister_netdev()") sought to fix a use-after-free on disconnect of USB Ethernet adapters.
It turns out that a different fix is necessary to address the issue: https://lore.kernel.org/netdev/18b3541e5372bc9b9fc733d422f4e698c089077c.1650...
So the commit was not necessary.
The commit made binding and unbinding of USB Ethernet asymmetrical: Before, usbnet_probe() first invoked the ->bind() callback and then register_netdev(). usbnet_disconnect() mirrored that by first invoking unregister_netdev() and then ->unbind().
Since the commit, the order in usbnet_disconnect() is reversed and no longer mirrors usbnet_probe().
One consequence is that a PHY disconnected (and stopped) in ->unbind() is afterwards stopped once more by unregister_netdev() as it closes the netdev before unregistering. That necessitates a contortion in ->stop() because the PHY may only be stopped if it hasn't already been disconnected.
Reverting the commit allows making the call to phy_stop() unconditional in ->stop().
Tested-by: Oleksij Rempel o.rempel@pengutronix.de # LAN9514/9512/9500 Tested-by: Ferry Toth fntoth@gmail.com # LAN9514 Signed-off-by: Lukas Wunner lukas@wunner.de Acked-by: Oliver Neukum oneukum@suse.com Cc: Martyn Welch martyn.welch@collabora.com Cc: Andrew Lunn andrew@lunn.ch Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/asix_devices.c | 6 +----- drivers/net/usb/smsc95xx.c | 3 +-- drivers/net/usb/usbnet.c | 6 +++--- 3 files changed, 5 insertions(+), 10 deletions(-)
diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c index 6b2fbdf4e0fd..34854ee537dc 100644 --- a/drivers/net/usb/asix_devices.c +++ b/drivers/net/usb/asix_devices.c @@ -799,11 +799,7 @@ static int ax88772_stop(struct usbnet *dev) { struct asix_common_private *priv = dev->driver_priv;
- /* On unplugged USB, we will get MDIO communication errors and the - * PHY will be set in to PHY_HALTED state. - */ - if (priv->phydev->state != PHY_HALTED) - phy_stop(priv->phydev); + phy_stop(priv->phydev);
return 0; } diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index a0f29482294d..d81485cd7e90 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -1218,8 +1218,7 @@ static int smsc95xx_start_phy(struct usbnet *dev)
static int smsc95xx_stop(struct usbnet *dev) { - if (dev->net->phydev) - phy_stop(dev->net->phydev); + phy_stop(dev->net->phydev);
return 0; } diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 9a6450f796dc..36b24ec11650 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1616,9 +1616,6 @@ void usbnet_disconnect (struct usb_interface *intf) xdev->bus->bus_name, xdev->devpath, dev->driver_info->description);
- if (dev->driver_info->unbind) - dev->driver_info->unbind(dev, intf); - net = dev->net; unregister_netdev (net);
@@ -1626,6 +1623,9 @@ void usbnet_disconnect (struct usb_interface *intf)
usb_scuttle_anchored_urbs(&dev->deferred);
+ if (dev->driver_info->unbind) + dev->driver_info->unbind(dev, intf); + usb_kill_urb(dev->interrupt); usb_free_urb(dev->interrupt); kfree(dev->padding_pkt);