Subject: Re: [PATCH v2] lan743x: Fix for potential null pointer dereference

From: Andrew Lunn <[email-masked]>
Date: Sun, 1 Nov 2020 21:38:20 +0100

On Sun, Nov 01, 2020 at 10:54:38PM +0300, Sergej Bauer wrote:
> > > Signed-off-by: Sergej Bauer <[email-masked]>
> > 
> > * I miss a change description here.
> The reason for the fix is when the device is down netdev->phydev will be NULL 
> and there is no checking for this situation. So 'ethtool ethN' leads to kernel 
> panic.

> > > @@ -809,9 +812,12 @@ static int lan743x_ethtool_set_wol(struct net_device
> > > *netdev,> 
> > >  	device_set_wakeup_enable(&adapter->pdev->dev, (bool)wol->wolopts);
> > > 
> > > -	phy_ethtool_set_wol(netdev->phydev, wol);
> > > +	if (netdev->phydev)
> > > +		ret = phy_ethtool_set_wol(netdev->phydev, wol);
> > > +	else
> > > +		ret = -EIO;

-ENETDOWN would be better, it gives a hit that WoL can be configured
when the interface is configured up.

 Andrew