[PATCH v1 net-next 2/7] ip_tunnel: Set itn->fb_tunnel_dev to NULL in ip_tunnel_delete_net().
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-09-07 22:58:56
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
ip_tunnel_dellink() ignores itn->fb_tunnel_dev, so the per-netns fallback tunnel device cannot be removed by userspace. This also makes default_device_exit_batch() impossible to remove the device since it calls ->dellink(). So, ip_tunnel_delete_net() has to iterate devices in the dying netns and call unregister_netdevice_queue() directly. But then, this duplicates ip_tunnel_del() in ip_tunnel_dellink() and ip_tunnel_uninit(). Let's set itn->fb_tunnel_dev to NULL in ip_tunnel_delete_net() and remove for_each_netdev_safe() in ip_tunnel_delete_net(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> --- net/ipv4/ip_tunnel.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index e6bcf01411d0..d29e2ba7cdd3 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c@@ -1155,26 +1155,19 @@ void ip_tunnel_delete_net(struct net *net, unsigned int id, struct list_head *head) { struct ip_tunnel_net *itn = net_generic(net, id); - struct net_device *dev, *aux; int h; ASSERT_RTNL_NET(net); - for_each_netdev_safe(net, dev, aux) - if (dev->rtnl_link_ops == ops) - unregister_netdevice_queue(dev, head); + WRITE_ONCE(itn->fb_tunnel_dev, NULL); for (h = 0; h < IP_TNL_HASH_SIZE; h++) { - struct ip_tunnel *t; - struct hlist_node *n; struct hlist_head *thead = &itn->tunnels[h]; + struct hlist_node *n; + struct ip_tunnel *t; hlist_for_each_entry_safe(t, n, thead, hash_node) - /* If dev is in the same netns, it has already - * been added to the list by the previous loop. - */ - if (!net_eq(dev_net(t->dev), net)) - unregister_netdevice_queue(t->dev, head); + unregister_netdevice_queue(t->dev, head); } } EXPORT_SYMBOL_GPL(ip_tunnel_delete_net);
@@ -1310,8 +1303,6 @@ void ip_tunnel_uninit(struct net_device *dev) itn = net_generic(net, tunnel->ip_tnl_net_id); ip_tunnel_del(itn, netdev_priv(dev)); - if (itn->fb_tunnel_dev == dev) - WRITE_ONCE(itn->fb_tunnel_dev, NULL); dst_cache_reset(&tunnel->dst_cache); }
--
2.55.0.1003.g10538fe699-goog