diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 4cfdef6ca4f6..c8490729b4ae 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -64,6 +64,14 @@ struct inet6_ifaddr {
 
 	struct hlist_node	addr_lst;
 	struct list_head	if_list;
+	/*
+	 * Used to safely traverse idev->addr_list in process context
+	 * if the idev->lock needed to protect idev->addr_list cannot be held.
+	 * In that case, add the items to this list temporarily and iterate
+	 * without holding idev->lock.
+	 * See addrconf_ifdown and dev_forward_change.
+	 */
+	struct list_head	if_list_aux;
 
 	struct list_head	tmp_list;
 	struct inet6_ifaddr	*ifpub;
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index b22504176588..1afc4c024981 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -797,6 +797,7 @@ static void dev_forward_change(struct inet6_dev *idev)
 {
 	struct net_device *dev;
 	struct inet6_ifaddr *ifa;
+	LIST_HEAD(tmp_addr_list);
 
 	if (!idev)
 		return;
@@ -815,14 +816,24 @@ static void dev_forward_change(struct inet6_dev *idev)
 		}
 	}
 
+	read_lock_bh(&idev->lock);
 	list_for_each_entry(ifa, &idev->addr_list, if_list) {
 		if (ifa->flags&IFA_F_TENTATIVE)
 			continue;
+		list_add_tail(&ifa->if_list_aux, &tmp_addr_list);
+	}
+	read_unlock_bh(&idev->lock);
+
+	while (!list_empty(&tmp_addr_list)) {
+		ifa = list_first_entry(&tmp_addr_list,
+				       struct inet6_ifaddr, if_list_aux);
+		list_del(&ifa->if_list_aux);
 		if (idev->cnf.forwarding)
 			addrconf_join_anycast(ifa);
 		else
 			addrconf_leave_anycast(ifa);
 	}
+
 	inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
 				     NETCONFA_FORWARDING,
 				     dev->ifindex, &idev->cnf);
@@ -3728,7 +3739,8 @@ static int addrconf_ifdown(struct net_device *dev, bool unregister)
 	unsigned long event = unregister ? NETDEV_UNREGISTER : NETDEV_DOWN;
 	struct net *net = dev_net(dev);
 	struct inet6_dev *idev;
-	struct inet6_ifaddr *ifa, *tmp;
+	struct inet6_ifaddr *ifa;
+	LIST_HEAD(tmp_addr_list);
 	bool keep_addr = false;
 	bool was_ready;
 	int state, i;
@@ -3820,16 +3832,23 @@ restart:
 		write_lock_bh(&idev->lock);
 	}
 
-	list_for_each_entry_safe(ifa, tmp, &idev->addr_list, if_list) {
+	list_for_each_entry(ifa, &idev->addr_list, if_list)
+		list_add_tail(&ifa->if_list_aux, &tmp_addr_list);
+	write_unlock_bh(&idev->lock);
+
+	while (!list_empty(&tmp_addr_list)) {
 		struct fib6_info *rt = NULL;
 		bool keep;
 
+		ifa = list_first_entry(&tmp_addr_list,
+				       struct inet6_ifaddr, if_list_aux);
+		list_del(&ifa->if_list_aux);
+
 		addrconf_del_dad_work(ifa);
 
 		keep = keep_addr && (ifa->flags & IFA_F_PERMANENT) &&
 			!addr_is_local(&ifa->addr);
 
-		write_unlock_bh(&idev->lock);
 		spin_lock_bh(&ifa->lock);
 
 		if (keep) {
@@ -3860,15 +3879,14 @@ restart:
 			addrconf_leave_solict(ifa->idev, &ifa->addr);
 		}
 
-		write_lock_bh(&idev->lock);
 		if (!keep) {
+			write_lock_bh(&idev->lock);
 			list_del_rcu(&ifa->if_list);
+			write_unlock_bh(&idev->lock);
 			in6_ifa_put(ifa);
 		}
 	}
 
-	write_unlock_bh(&idev->lock);
-
 	/* Step 5: Discard anycast and multicast list */
 	if (unregister) {
 		ipv6_ac_destroy_dev(idev);