1 files changed, 5 insertions, 0 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2d3949789cef..e86b28482ca7 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -418,9 +418,11 @@ void __rtnl_link_unregister(struct rtnl_link_ops *ops)
 {
         struct net *net;
 
+        down_read(&net_rwsem);
         for_each_net(net) {
                 __rtnl_kill_links(net, ops);
         }
+        up_read(&net_rwsem);
         list_del(&ops->list);
 }
 EXPORT_SYMBOL_GPL(__rtnl_link_unregister);
@@ -438,6 +440,9 @@ static void rtnl_lock_unregistering_all(void)
         for (;;) {
                 unregistering = false;
                 rtnl_lock();
+                /* We held write locked pernet_ops_rwsem, and parallel
+                 * setup_net() and cleanup_net() are not possible.
+                 */
                 for_each_net(net) {
                         if (net->dev_unreg_count > 0) {
                                 unregistering = true;