[PATCH v1 net-next 05/14] net: Hold __rtnl_net_lock() in netdev_wait_allrefs_any().

[Kuniyuki Iwashima <kuniyu@google.com>]

Currently, netdev_run_todo() processes pending devices from multiple
namespaces in a batch.

To expand the per-netns RTNL coverage for NETDEV_UNREGISTER, let's
acquire __rtnl_net_lock() in netdev_wait_allrefs_any().

Note that netdev_run_todo() itself will need to be namespacified
before RTNL is removed.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 net/core/dev.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index c477c4f84ed9..48818a194fa5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -11608,8 +11608,13 @@ static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
 			rtnl_lock();
 
 			/* Rebroadcast unregister notification */
-			list_for_each_entry(dev, list, todo_list)
+			list_for_each_entry(dev, list, todo_list) {
+				struct net *net = dev_net(dev);
+
+				__rtnl_net_lock(net);
 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
+				__rtnl_net_unlock(net);
+			}
 
 			__rtnl_unlock();
 			rcu_barrier();
-- 
2.55.0.rc0.799.gd6f94ed593-goog