flow_offload: action should not be NULL when it is referenced

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

include/net/flow_offload.h

@@ -319,6 +319,7 @@ flow_action_mixed_hw_stats_check(const struct flow_action *action,
 	if (flow_offload_has_one_action(action))
 		return true;
 
+	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");
@@ -326,6 +327,7 @@ flow_action_mixed_hw_stats_check(const struct flow_action *action,
 			}
 			last_hw_stats = action_entry->hw_stats;
 		}
+	}
 	return true;
 }