4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 5983587c8c5ef00d6886477544ad67d495bc5479 ]

Currently if the stat type is invalid then data[i] is being set
either by dereferencing a null pointer p, or it is reading from
an incorrect previous location if we had a valid stat type
previously.  Fix this by skipping over the read of p on an invalid
stat type.

Detected by CoverityScan, CID#113385 ("Explicit null dereferenced")

Signed-off-by: Colin Ian King <colin.k...@canonical.com>
Reviewed-by: Alexander Duyck <alexander.h.du...@intel.com>
Tested-by: Aaron Brown <aaron.f.br...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/net/ethernet/intel/e1000/e1000_ethtool.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c 
b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
index 5ae8874bbf72..d70b2e5d5222 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
@@ -1826,11 +1826,12 @@ static void e1000_get_ethtool_stats(struct net_device 
*netdev,
 {
        struct e1000_adapter *adapter = netdev_priv(netdev);
        int i;
-       char *p = NULL;
        const struct e1000_stats *stat = e1000_gstrings_stats;
 
        e1000_update_stats(adapter);
-       for (i = 0; i < E1000_GLOBAL_STATS_LEN; i++) {
+       for (i = 0; i < E1000_GLOBAL_STATS_LEN; i++, stat++) {
+               char *p;
+
                switch (stat->type) {
                case NETDEV_STATS:
                        p = (char *)netdev + stat->stat_offset;
@@ -1841,15 +1842,13 @@ static void e1000_get_ethtool_stats(struct net_device 
*netdev,
                default:
                        WARN_ONCE(1, "Invalid E1000 stat type: %u index %d\n",
                                  stat->type, i);
-                       break;
+                       continue;
                }
 
                if (stat->sizeof_stat == sizeof(u64))
                        data[i] = *(u64 *)p;
                else
                        data[i] = *(u32 *)p;
-
-               stat++;
        }
 /* BUG_ON(i != E1000_STATS_LEN); */
 }
-- 
2.17.1



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