vlan/macvlan: fix NULL pointer dereferences in ethtool handlers

[ Upstream commit 7816a0a862d851d0b05710e7d94bfe390f3180e2 ]

Check whether the underlying device provides a set of ethtool ops before
checking for individual handlers to avoid NULL pointer dereferences.

Reported-by: Art van Breemen <ard@telegraafnet.nl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 4239450..1aa0388 100644 (file)
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -328,7 +328,8 @@ static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
        const struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;
 
-       if (lowerdev->ethtool_ops->get_rx_csum == NULL)
+       if (lowerdev->ethtool_ops == NULL ||
+           lowerdev->ethtool_ops->get_rx_csum == NULL)
                return 0;
        return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
 }