ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0107-wireguard-device-avoid-circular-netns-references.patch b/target/linux/generic/backport-5.4/080-wireguard-0107-wireguard-device-avoid-circular-netns-references.patch
new file mode 100644
index 0000000..013023a
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0107-wireguard-device-avoid-circular-netns-references.patch
@@ -0,0 +1,296 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Tue, 23 Jun 2020 03:59:45 -0600
+Subject: [PATCH] wireguard: device: avoid circular netns references
+
+commit 900575aa33a3eaaef802b31de187a85c4a4b4bd0 upstream.
+
+Before, we took a reference to the creating netns if the new netns was
+different. This caused issues with circular references, with two
+wireguard interfaces swapping namespaces. The solution is to rather not
+take any extra references at all, but instead simply invalidate the
+creating netns pointer when that netns is deleted.
+
+In order to prevent this from happening again, this commit improves the
+rough object leak tracking by allowing it to account for created and
+destroyed interfaces, aside from just peers and keys. That then makes it
+possible to check for the object leak when having two interfaces take a
+reference to each others' namespaces.
+
+Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ drivers/net/wireguard/device.c | 58 ++++++++++------------
+ drivers/net/wireguard/device.h | 3 +-
+ drivers/net/wireguard/netlink.c | 14 ++++--
+ drivers/net/wireguard/socket.c | 25 +++++++---
+ tools/testing/selftests/wireguard/netns.sh | 13 ++++-
+ 5 files changed, 67 insertions(+), 46 deletions(-)
+
+--- a/drivers/net/wireguard/device.c
++++ b/drivers/net/wireguard/device.c
+@@ -45,17 +45,18 @@ static int wg_open(struct net_device *de
+ if (dev_v6)
+ dev_v6->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_NONE;
+
++ mutex_lock(&wg->device_update_lock);
+ ret = wg_socket_init(wg, wg->incoming_port);
+ if (ret < 0)
+- return ret;
+- mutex_lock(&wg->device_update_lock);
++ goto out;
+ list_for_each_entry(peer, &wg->peer_list, peer_list) {
+ wg_packet_send_staged_packets(peer);
+ if (peer->persistent_keepalive_interval)
+ wg_packet_send_keepalive(peer);
+ }
++out:
+ mutex_unlock(&wg->device_update_lock);
+- return 0;
++ return ret;
+ }
+
+ #ifdef CONFIG_PM_SLEEP
+@@ -225,6 +226,7 @@ static void wg_destruct(struct net_devic
+ list_del(&wg->device_list);
+ rtnl_unlock();
+ mutex_lock(&wg->device_update_lock);
++ rcu_assign_pointer(wg->creating_net, NULL);
+ wg->incoming_port = 0;
+ wg_socket_reinit(wg, NULL, NULL);
+ /* The final references are cleared in the below calls to destroy_workqueue. */
+@@ -240,13 +242,11 @@ static void wg_destruct(struct net_devic
+ skb_queue_purge(&wg->incoming_handshakes);
+ free_percpu(dev->tstats);
+ free_percpu(wg->incoming_handshakes_worker);
+- if (wg->have_creating_net_ref)
+- put_net(wg->creating_net);
+ kvfree(wg->index_hashtable);
+ kvfree(wg->peer_hashtable);
+ mutex_unlock(&wg->device_update_lock);
+
+- pr_debug("%s: Interface deleted\n", dev->name);
++ pr_debug("%s: Interface destroyed\n", dev->name);
+ free_netdev(dev);
+ }
+
+@@ -292,7 +292,7 @@ static int wg_newlink(struct net *src_ne
+ struct wg_device *wg = netdev_priv(dev);
+ int ret = -ENOMEM;
+
+- wg->creating_net = src_net;
++ rcu_assign_pointer(wg->creating_net, src_net);
+ init_rwsem(&wg->static_identity.lock);
+ mutex_init(&wg->socket_update_lock);
+ mutex_init(&wg->device_update_lock);
+@@ -393,30 +393,26 @@ static struct rtnl_link_ops link_ops __r
+ .newlink = wg_newlink,
+ };
+
+-static int wg_netdevice_notification(struct notifier_block *nb,
+- unsigned long action, void *data)
++static void wg_netns_pre_exit(struct net *net)
+ {
+- struct net_device *dev = ((struct netdev_notifier_info *)data)->dev;
+- struct wg_device *wg = netdev_priv(dev);
+-
+- ASSERT_RTNL();
+-
+- if (action != NETDEV_REGISTER || dev->netdev_ops != &netdev_ops)
+- return 0;
++ struct wg_device *wg;
+
+- if (dev_net(dev) == wg->creating_net && wg->have_creating_net_ref) {
+- put_net(wg->creating_net);
+- wg->have_creating_net_ref = false;
+- } else if (dev_net(dev) != wg->creating_net &&
+- !wg->have_creating_net_ref) {
+- wg->have_creating_net_ref = true;
+- get_net(wg->creating_net);
++ rtnl_lock();
++ list_for_each_entry(wg, &device_list, device_list) {
++ if (rcu_access_pointer(wg->creating_net) == net) {
++ pr_debug("%s: Creating namespace exiting\n", wg->dev->name);
++ netif_carrier_off(wg->dev);
++ mutex_lock(&wg->device_update_lock);
++ rcu_assign_pointer(wg->creating_net, NULL);
++ wg_socket_reinit(wg, NULL, NULL);
++ mutex_unlock(&wg->device_update_lock);
++ }
+ }
+- return 0;
++ rtnl_unlock();
+ }
+
+-static struct notifier_block netdevice_notifier = {
+- .notifier_call = wg_netdevice_notification
++static struct pernet_operations pernet_ops = {
++ .pre_exit = wg_netns_pre_exit
+ };
+
+ int __init wg_device_init(void)
+@@ -429,18 +425,18 @@ int __init wg_device_init(void)
+ return ret;
+ #endif
+
+- ret = register_netdevice_notifier(&netdevice_notifier);
++ ret = register_pernet_device(&pernet_ops);
+ if (ret)
+ goto error_pm;
+
+ ret = rtnl_link_register(&link_ops);
+ if (ret)
+- goto error_netdevice;
++ goto error_pernet;
+
+ return 0;
+
+-error_netdevice:
+- unregister_netdevice_notifier(&netdevice_notifier);
++error_pernet:
++ unregister_pernet_device(&pernet_ops);
+ error_pm:
+ #ifdef CONFIG_PM_SLEEP
+ unregister_pm_notifier(&pm_notifier);
+@@ -451,7 +447,7 @@ error_pm:
+ void wg_device_uninit(void)
+ {
+ rtnl_link_unregister(&link_ops);
+- unregister_netdevice_notifier(&netdevice_notifier);
++ unregister_pernet_device(&pernet_ops);
+ #ifdef CONFIG_PM_SLEEP
+ unregister_pm_notifier(&pm_notifier);
+ #endif
+--- a/drivers/net/wireguard/device.h
++++ b/drivers/net/wireguard/device.h
+@@ -40,7 +40,7 @@ struct wg_device {
+ struct net_device *dev;
+ struct crypt_queue encrypt_queue, decrypt_queue;
+ struct sock __rcu *sock4, *sock6;
+- struct net *creating_net;
++ struct net __rcu *creating_net;
+ struct noise_static_identity static_identity;
+ struct workqueue_struct *handshake_receive_wq, *handshake_send_wq;
+ struct workqueue_struct *packet_crypt_wq;
+@@ -56,7 +56,6 @@ struct wg_device {
+ unsigned int num_peers, device_update_gen;
+ u32 fwmark;
+ u16 incoming_port;
+- bool have_creating_net_ref;
+ };
+
+ int wg_device_init(void);
+--- a/drivers/net/wireguard/netlink.c
++++ b/drivers/net/wireguard/netlink.c
+@@ -517,11 +517,15 @@ static int wg_set_device(struct sk_buff
+ if (flags & ~__WGDEVICE_F_ALL)
+ goto out;
+
+- ret = -EPERM;
+- if ((info->attrs[WGDEVICE_A_LISTEN_PORT] ||
+- info->attrs[WGDEVICE_A_FWMARK]) &&
+- !ns_capable(wg->creating_net->user_ns, CAP_NET_ADMIN))
+- goto out;
++ if (info->attrs[WGDEVICE_A_LISTEN_PORT] || info->attrs[WGDEVICE_A_FWMARK]) {
++ struct net *net;
++ rcu_read_lock();
++ net = rcu_dereference(wg->creating_net);
++ ret = !net || !ns_capable(net->user_ns, CAP_NET_ADMIN) ? -EPERM : 0;
++ rcu_read_unlock();
++ if (ret)
++ goto out;
++ }
+
+ ++wg->device_update_gen;
+
+--- a/drivers/net/wireguard/socket.c
++++ b/drivers/net/wireguard/socket.c
+@@ -347,6 +347,7 @@ static void set_sock_opts(struct socket
+
+ int wg_socket_init(struct wg_device *wg, u16 port)
+ {
++ struct net *net;
+ int ret;
+ struct udp_tunnel_sock_cfg cfg = {
+ .sk_user_data = wg,
+@@ -371,37 +372,47 @@ int wg_socket_init(struct wg_device *wg,
+ };
+ #endif
+
++ rcu_read_lock();
++ net = rcu_dereference(wg->creating_net);
++ net = net ? maybe_get_net(net) : NULL;
++ rcu_read_unlock();
++ if (unlikely(!net))
++ return -ENONET;
++
+ #if IS_ENABLED(CONFIG_IPV6)
+ retry:
+ #endif
+
+- ret = udp_sock_create(wg->creating_net, &port4, &new4);
++ ret = udp_sock_create(net, &port4, &new4);
+ if (ret < 0) {
+ pr_err("%s: Could not create IPv4 socket\n", wg->dev->name);
+- return ret;
++ goto out;
+ }
+ set_sock_opts(new4);
+- setup_udp_tunnel_sock(wg->creating_net, new4, &cfg);
++ setup_udp_tunnel_sock(net, new4, &cfg);
+
+ #if IS_ENABLED(CONFIG_IPV6)
+ if (ipv6_mod_enabled()) {
+ port6.local_udp_port = inet_sk(new4->sk)->inet_sport;
+- ret = udp_sock_create(wg->creating_net, &port6, &new6);
++ ret = udp_sock_create(net, &port6, &new6);
+ if (ret < 0) {
+ udp_tunnel_sock_release(new4);
+ if (ret == -EADDRINUSE && !port && retries++ < 100)
+ goto retry;
+ pr_err("%s: Could not create IPv6 socket\n",
+ wg->dev->name);
+- return ret;
++ goto out;
+ }
+ set_sock_opts(new6);
+- setup_udp_tunnel_sock(wg->creating_net, new6, &cfg);
++ setup_udp_tunnel_sock(net, new6, &cfg);
+ }
+ #endif
+
+ wg_socket_reinit(wg, new4->sk, new6 ? new6->sk : NULL);
+- return 0;
++ ret = 0;
++out:
++ put_net(net);
++ return ret;
+ }
+
+ void wg_socket_reinit(struct wg_device *wg, struct sock *new4,
+--- a/tools/testing/selftests/wireguard/netns.sh
++++ b/tools/testing/selftests/wireguard/netns.sh
+@@ -587,9 +587,20 @@ ip0 link set wg0 up
+ kill $ncat_pid
+ ip0 link del wg0
+
++# Ensure there aren't circular reference loops
++ip1 link add wg1 type wireguard
++ip2 link add wg2 type wireguard
++ip1 link set wg1 netns $netns2
++ip2 link set wg2 netns $netns1
++pp ip netns delete $netns1
++pp ip netns delete $netns2
++pp ip netns add $netns1
++pp ip netns add $netns2
++
++sleep 2 # Wait for cleanup and grace periods
+ declare -A objects
+ while read -t 0.1 -r line 2>/dev/null || [[ $? -ne 142 ]]; do
+- [[ $line =~ .*(wg[0-9]+:\ [A-Z][a-z]+\ [0-9]+)\ .*(created|destroyed).* ]] || continue
++ [[ $line =~ .*(wg[0-9]+:\ [A-Z][a-z]+\ ?[0-9]*)\ .*(created|destroyed).* ]] || continue
+ objects["${BASH_REMATCH[1]}"]+="${BASH_REMATCH[2]}"
+ done < /dev/kmsg
+ alldeleted=1