flow_offload: action should not be NULL when it is referenced

"action" should not be NULL when it is referenced.
Signed-off-by: Ngushengxian <13145886936@163.com>
Signed-off-by: Ngushengxian <gushengxian@yulong.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/flow_offload.h

@@ -319,12 +319,14 @@ flow_action_mixed_hw_stats_check(const struct flow_action *action,
 	if (flow_offload_has_one_action(action))
 		return true;
 
-	flow_action_for_each(i, action_entry, action) {
-		if (i && action_entry->hw_stats != last_hw_stats) {
-			NL_SET_ERR_MSG_MOD(extack, "Mixing HW stats types for actions is not supported");
-			return false;
+	if (action) {
+		flow_action_for_each(i, action_entry, action) {
+			if (i && action_entry->hw_stats != last_hw_stats) {
+				NL_SET_ERR_MSG_MOD(extack, "Mixing HW stats types for actions is not supported");
+				return false;
+			}
+			last_hw_stats = action_entry->hw_stats;
 		}
-		last_hw_stats = action_entry->hw_stats;
 	}
 	return true;
 }