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Commit 4f9dce23 authored by Ben Hutchings's avatar Ben Hutchings Committed by David S. Miller
Browse files

sh_eth: Fix ethtool operation crash when net device is down 



The driver connects and disconnects the PHY device whenever the
net device is brought up and down.  The ethtool get_settings,
set_settings and nway_reset operations will dereference a null
or dangling pointer if called while it is down.

I think it would be preferable to keep the PHY connected, but there
may be good reasons not to.

As an immediate fix for this bug:
- Set the phydev pointer to NULL after disconnecting the PHY
- Change those three operations to return -ENODEV while the PHY is
  not connected

Signed-off-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b37feed7

drivers/net/ethernet/renesas/sh_eth.c

+10 −0
Original line number Diff line number Diff line
@@ -1827,6 +1827,9 @@ static int sh_eth_get_settings(struct net_device *ndev, 
	unsigned long flags;

	int ret;



	if (!mdp->phydev)

		return -ENODEV;



	spin_lock_irqsave(&mdp->lock, flags);

	ret = phy_ethtool_gset(mdp->phydev, ecmd);

	spin_unlock_irqrestore(&mdp->lock, flags);
@@ -1841,6 +1844,9 @@ static int sh_eth_set_settings(struct net_device *ndev, 
	unsigned long flags;

	int ret;



	if (!mdp->phydev)

		return -ENODEV;



	spin_lock_irqsave(&mdp->lock, flags);



	/* disable tx and rx */
@@ -1875,6 +1881,9 @@ static int sh_eth_nway_reset(struct net_device *ndev) 
	unsigned long flags;

	int ret;



	if (!mdp->phydev)

		return -ENODEV;



	spin_lock_irqsave(&mdp->lock, flags);

	ret = phy_start_aneg(mdp->phydev);

	spin_unlock_irqrestore(&mdp->lock, flags);
@@ -2184,6 +2193,7 @@ static int sh_eth_close(struct net_device *ndev) 
	if (mdp->phydev) {

		phy_stop(mdp->phydev);

		phy_disconnect(mdp->phydev);

		mdp->phydev = NULL;

	}



	free_irq(ndev->irq, ndev);