gianfar: Fix overflow check and return value for gfar_get_cls_all()

This function may currently fill one entry beyond the end of the
array it is given.  It also doesn't return an error code in case
it does detect overflow.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/net/gianfar_ethtool.c b/drivers/net/gianfar_ethtool.c
index 25a8c2adb00..0caf3c323ec 100644
--- a/drivers/net/gianfar_ethtool.c
+++ b/drivers/net/gianfar_ethtool.c
@@ -1669,10 +1669,10 @@ static int gfar_get_cls_all(struct gfar_private *priv,
         u32 i = 0;
 
         list_for_each_entry(comp, &priv->rx_list.list, list) {
-                if (i <= cmd->rule_cnt) {
-                        rule_locs[i] = comp->fs.location;
-                        i++;
-                }
+                if (i == cmd->rule_cnt)
+                        return -EMSGSIZE;
+                rule_locs[i] = comp->fs.location;
+                i++;
         }
 
         cmd->data = MAX_FILER_IDX;