From 58d5e964c7ce6a44efb5f4d5dfb69aa3890c730c Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Tue, 23 Jun 2020 03:59:45 -0600 Subject: UPSTREAM: wireguard: device: avoid circular netns references 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 Signed-off-by: David S. Miller (cherry picked from commit 900575aa33a3eaaef802b31de187a85c4a4b4bd0) Bug: 152722841 [Jason: netlink notifier uses exit instead of pre_exit] Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman Change-Id: Iea52fe3ca0e41318c392d9e91edb1856de6c9528 --- drivers/net/wireguard/socket.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) (limited to 'drivers/net/wireguard/socket.c') diff --git a/drivers/net/wireguard/socket.c b/drivers/net/wireguard/socket.c index f9018027fc13..c33e2c81635f 100644 --- a/drivers/net/wireguard/socket.c +++ b/drivers/net/wireguard/socket.c @@ -347,6 +347,7 @@ static void set_sock_opts(struct socket *sock) 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, u16 port) }; #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, -- cgit v1.2.3