i40evf: ethtool RSS fixes

Add an extra check to make sure that the indirection table pointer is
valid before dereferencing it.

Change-ID: I698adbf3daff03081d01f489dc95a9f1ad8b12f1
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c b/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
index c5ffaccb59d3..681a5d4b4f6a 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
@@ -642,12 +642,14 @@ static int i40evf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
         if (!indir)
                 return 0;
 
-        for (i = 0, j = 0; i <= I40E_VFQF_HLUT_MAX_INDEX; i++) {
-                hlut_val = rd32(hw, I40E_VFQF_HLUT(i));
-                indir[j++] = hlut_val & 0xff;
-                indir[j++] = (hlut_val >> 8) & 0xff;
-                indir[j++] = (hlut_val >> 16) & 0xff;
-                indir[j++] = (hlut_val >> 24) & 0xff;
+        if (indir) {
+                for (i = 0, j = 0; i <= I40E_VFQF_HLUT_MAX_INDEX; i++) {
+                        hlut_val = rd32(hw, I40E_VFQF_HLUT(i));
+                        indir[j++] = hlut_val & 0xff;
+                        indir[j++] = (hlut_val >> 8) & 0xff;
+                        indir[j++] = (hlut_val >> 16) & 0xff;
+                        indir[j++] = (hlut_val >> 24) & 0xff;
+                }
         }
         return 0;
 }