ethtool: prevent null pointer dereference with NTUPLE set but no set_rx_ntuple

This change is meant to prevent a possible null pointer dereference if
NETIF_F_NTUPLE is defined but the set_rx_ntuple function pointer is not.

The main motivation behind this patch is to eventually replace the ntuple
interfaces entirely with the network flow classifier interfaces.  This
allows the device drivers to maintain the ntuple check internally while
using the network flow classifier interface for setting up and displaying
rules.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 1b7fa984de7d743903472c5c16215f5329621764..704e176ad3a99381d4a055609d17427020809649 100644 (file)
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -910,6 +910,9 @@ static noinline_for_stack int ethtool_set_rx_ntuple(struct net_device *dev,
        struct ethtool_rx_ntuple_flow_spec_container *fsc = NULL;
        int ret;
 
+       if (!ops->set_rx_ntuple)
+               return -EOPNOTSUPP;
+
        if (!(dev->features & NETIF_F_NTUPLE))
                return -EINVAL;