vlan/macvlan: fix NULL pointer dereferences in ethtool handlers

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>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 70d3ef4a2c5f..214a8cf2b708 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -376,7 +376,8 @@ 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);
 }
@@ -387,7 +388,8 @@ static int macvlan_ethtool_get_settings(struct net_device *dev,
         const struct macvlan_dev *vlan = netdev_priv(dev);
         struct net_device *lowerdev = vlan->lowerdev;
 
-        if (!lowerdev->ethtool_ops->get_settings)
+        if (!lowerdev->ethtool_ops ||
+            !lowerdev->ethtool_ops->get_settings)
                 return -EOPNOTSUPP;
 
         return lowerdev->ethtool_ops->get_settings(lowerdev, cmd);
@@ -398,7 +400,8 @@ static u32 macvlan_ethtool_get_flags(struct net_device *dev)
         const struct macvlan_dev *vlan = netdev_priv(dev);
         struct net_device *lowerdev = vlan->lowerdev;
 
-        if (!lowerdev->ethtool_ops->get_flags)
+        if (!lowerdev->ethtool_ops ||
+            !lowerdev->ethtool_ops->get_flags)
                 return 0;
         return lowerdev->ethtool_ops->get_flags(lowerdev);
 }