Re: [PATCH net] net: core: Correctly iterate over lower adjacency list

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 136ae6bb..465e128 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h

@@ -3877,7 +3877,7 @@ struct net_device *netdev_all_lower_get_next_rcu(struct net_device *dev,
 	     ldev = netdev_all_lower_get_next(dev, &(iter)))
 
 #define netdev_for_each_all_lower_dev_rcu(dev, ldev, iter) \
-	for (iter = (dev)->all_adj_list.lower.next, \
+	for (iter = &(dev)->all_adj_list.lower, \
 	     ldev = netdev_all_lower_get_next_rcu(dev, &(iter)); \
 	     ldev; \
 	     ldev = netdev_all_lower_get_next_rcu(dev, &(iter)))

diff --git a/net/core/dev.c b/net/core/dev.c
index f1fe26f..b09ac57 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c

@@ -5511,10 +5511,14 @@ struct net_device *netdev_all_lower_get_next_rcu(struct net_device *dev,
 {
 	struct netdev_adjacent *lower;
 
-	lower = list_first_or_null_rcu(&dev->all_adj_list.lower,
-				       struct netdev_adjacent, list);
+	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
+
+	if (&lower->list == &dev->all_adj_list.lower)
+		return NULL;
+
+	*iter = &lower->list;
 
-	return lower ? lower->dev : NULL;
+	return lower->dev;
 }
 EXPORT_SYMBOL(netdev_all_lower_get_next_rcu);