[PATCH v1 net-next 2/3] geneve: Protect geneve_net and geneve_sock with per-netns mutex.
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-07-31 16:46:19
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
struct geneve_dev.net is the netns where the backend geneve socket resides. struct geneve_dev is linked to the geneve_net.geneve_list of the socket's netns. During netns dismantle or module unload, geneve_exit_rtnl_net() iterates the list and queues devices for destruction regardless of devices' netns. Moreover, a socket can be shared by multiple geneve devices in different netns, and geneve_open() and geneve_stop() modify geneve_sock.vni_list and geneve_net.sock_list. Thus, once RTNL is removed, the three lists can be modified concurrently from different netns due to device removal and link-up/down. Let's protect them with per-netns mutex. geneve_newlink() is still protected by rtnl_net_lock()s, so acquiring gn->lock twice in geneve_find_dev() and geneve_configure() is not a problem. Note that udp_tunnel_notify_add_rx_port() is moved outside of the mutex, otherwise gn->lock -> utn->lock ordering would trigger AB-BA deadlock in geneve_offload_rx_ports(), which acquires gn->lock under utn->lock. Even without gn->lock, geneve_sock_add() and geneve_offload_rx_ports() are still serialised with (per-netns) RTNL, so there is no race. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> --- drivers/net/geneve.c | 82 ++++++++++++++++++++++++++++++++++++-------- 1 file changed, 68 insertions(+), 14 deletions(-)
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index bd4fc6dba2fa..f456a85dca77 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c@@ -69,8 +69,8 @@ struct geneve_skb_cb { /* per-network namespace private data for this module */ struct geneve_net { struct list_head geneve_list; - /* sock_list is protected by rtnl lock */ struct list_head sock_list; + struct mutex lock; }; static unsigned int geneve_net_id;
@@ -1035,9 +1035,6 @@ static struct geneve_sock *geneve_socket_create(struct net *net, for (h = 0; h < VNI_HASH_SIZE; ++h) INIT_HLIST_HEAD(&gs->vni_list[h]); - /* Initialize the geneve udp offloads structure */ - udp_tunnel_notify_add_rx_port(sk, UDP_TUNNEL_TYPE_GENEVE); - /* Mark socket as an encapsulation socket */ memset(&tunnel_cfg, 0, sizeof(tunnel_cfg)); tunnel_cfg.sk_user_data = gs;
@@ -1056,6 +1053,7 @@ static void __geneve_sock_release(struct geneve_dev *geneve, bool ipv6) { struct geneve_dev_node *node; struct geneve_sock *gs; + struct geneve_net *gn; #if IS_ENABLED(CONFIG_IPV6) if (ipv6) {
@@ -1073,12 +1071,19 @@ static void __geneve_sock_release(struct geneve_dev *geneve, bool ipv6) if (!gs) return; + gn = net_generic(sock_net(gs->sk), geneve_net_id); + mutex_lock(&gn->lock); + hlist_del_init_rcu(&node->hlist); - if (--gs->refcnt) + if (--gs->refcnt) { + mutex_unlock(&gn->lock); return; + } list_del(&gs->list); + mutex_unlock(&gn->lock); + udp_tunnel_notify_del_rx_port(gs->sk, UDP_TUNNEL_TYPE_GENEVE); udp_tunnel_sock_release(gs->sk); kfree_rcu(gs, rcu);
@@ -1135,22 +1140,31 @@ static int geneve_sock_add(struct geneve_dev *geneve, struct net *net = geneve->net; struct geneve_dev_node *node; struct geneve_sock *gs; + struct geneve_net *gn; + bool created = false; __u8 vni[3]; + int ret = 0; __u32 hash; + gn = net_generic(net, geneve_net_id); + mutex_lock(&gn->lock); + gs = geneve_find_sock(net, geneve, cfg, ipv6); if (gs) { gs->refcnt++; - goto out; - } + } else { + gs = geneve_socket_create(net, geneve, cfg, ipv6); + if (IS_ERR(gs)) { + ret = PTR_ERR(gs); + goto out; + } - gs = geneve_socket_create(net, geneve, cfg, ipv6); - if (IS_ERR(gs)) - return PTR_ERR(gs); + created = true; + } -out: gs->collect_md = cfg->collect_md; gs->gro_hint = cfg->gro_hint; + #if IS_ENABLED(CONFIG_IPV6) if (ipv6) { rcu_assign_pointer(geneve->sock6, gs);
@@ -1166,7 +1180,16 @@ static int geneve_sock_add(struct geneve_dev *geneve, tunnel_id_to_vni(cfg->info.key.tun_id, vni); hash = geneve_net_vni_hash(vni); hlist_add_head_rcu(&node->hlist, &gs->vni_list[hash]); - return 0; + +out: + mutex_unlock(&gn->lock); + + if (created) { + /* Initialize the geneve udp offloads structure */ + udp_tunnel_notify_add_rx_port(gs->sk, UDP_TUNNEL_TYPE_GENEVE); + } + + return ret; } static int geneve_open(struct net_device *dev)
@@ -1743,6 +1766,8 @@ static void geneve_offload_rx_ports(struct net_device *dev, bool push) ASSERT_RTNL(); + mutex_lock(&gn->lock); + list_for_each_entry(gs, &gn->sock_list, list) { if (push) { udp_tunnel_push_rx_port(dev, gs->sk,
@@ -1752,6 +1777,8 @@ static void geneve_offload_rx_ports(struct net_device *dev, bool push) UDP_TUNNEL_TYPE_GENEVE); } } + + mutex_unlock(&gn->lock); } static struct geneve_config *geneve_config_alloc(const struct geneve_config *src)
@@ -1968,6 +1995,9 @@ static struct geneve_dev *geneve_find_dev(struct geneve_net *gn, *tun_on_same_port = false; *tun_collect_md = false; + + mutex_lock(&gn->lock); + list_for_each_entry(geneve, &gn->geneve_list, next) { const struct geneve_config *gcfg = rtnl_dereference(geneve->cfg);
@@ -1982,6 +2012,9 @@ static struct geneve_dev *geneve_find_dev(struct geneve_net *gn, !memcmp(&info->key.u, &gcfg->info.key.u, sizeof(info->key.u))) t = geneve; } + + mutex_unlock(&gn->lock); + return t; }
@@ -2076,7 +2109,10 @@ static int geneve_configure(struct net *net, struct net_device *dev, return err; } + mutex_lock(&gn->lock); list_add(&geneve->next, &gn->geneve_list); + mutex_unlock(&gn->lock); + return 0; }
@@ -2466,7 +2502,7 @@ static int geneve_changelink(struct net_device *dev, struct nlattr *tb[], return err; } -static void geneve_dellink(struct net_device *dev, struct list_head *head) +static void __geneve_dellink(struct net_device *dev, struct list_head *head) { struct geneve_dev *geneve = netdev_priv(dev);
@@ -2474,6 +2510,18 @@ static void geneve_dellink(struct net_device *dev, struct list_head *head) unregister_netdevice_queue(dev, head); } +static void geneve_dellink(struct net_device *dev, struct list_head *head) +{ + struct geneve_dev *geneve = netdev_priv(dev); + struct geneve_net *gn; + + gn = net_generic(geneve->net, geneve_net_id); + + mutex_lock(&gn->lock); + __geneve_dellink(dev, head); + mutex_unlock(&gn->lock); +} + static size_t geneve_get_size(const struct net_device *dev) { return nla_total_size(sizeof(__u32)) + /* IFLA_GENEVE_ID */
@@ -2692,6 +2740,8 @@ static __net_init int geneve_init_net(struct net *net) INIT_LIST_HEAD(&gn->geneve_list); INIT_LIST_HEAD(&gn->sock_list); + mutex_init(&gn->lock); + return 0; }
@@ -2701,8 +2751,12 @@ static void __net_exit geneve_exit_rtnl_net(struct net *net, struct geneve_net *gn = net_generic(net, geneve_net_id); struct geneve_dev *geneve, *next; + mutex_lock(&gn->lock); + list_for_each_entry_safe(geneve, next, &gn->geneve_list, next) - geneve_dellink(geneve->dev, dev_to_kill); + __geneve_dellink(geneve->dev, dev_to_kill); + + mutex_unlock(&gn->lock); } static void __net_exit geneve_exit_net(struct net *net)
--
2.55.0.571.g244d577d93-goog