[net-2.6 PATCH] ethtool: prevent null pointer dereference with NTUPLE set but no set_rx_ntuple

[Alexander Duyck <alexander.h.duyck@intel.com>]

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.

This issue appears to affect all kernels since 2.6.34.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---

 net/core/ethtool.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index c1a71bb..4843674 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -893,6 +893,9 @@ 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;