diff options
| author | Xin Long <lucien.xin@gmail.com> | 2018-11-13 01:08:25 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-23 08:17:05 +0100 |
| commit | 79272fc2c124166ea9c0960241fc60cd47712ef3 (patch) | |
| tree | 7831ab45015c9de8735e57c27bfbecc2968ef244 /net/l2tp | |
| parent | 115973a608a1d99f8569496cb6f0f165be325f19 (diff) | |
l2tp: fix a sock refcnt leak in l2tp_tunnel_register
[ Upstream commit f8504f4ca0a0e9f84546ef86e00b24d2ea9a0bd2 ]
This issue happens when trying to add an existent tunnel. It
doesn't call sock_put() before returning -EEXIST to release
the sock refcnt that was held by calling sock_hold() before
the existence check.
This patch is to fix it by holding the sock after doing the
existence check.
Fixes: f6cd651b056f ("l2tp: fix race in duplicate tunnel detection")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/l2tp')
| -rw-r--r-- | net/l2tp/l2tp_core.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 82cdf9020b53..26f1d435696a 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1490,12 +1490,7 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, goto err_sock; } - sk = sock->sk; - - sock_hold(sk); - tunnel->sock = sk; tunnel->l2tp_net = net; - pn = l2tp_pernet(net); spin_lock_bh(&pn->l2tp_tunnel_list_lock); @@ -1510,6 +1505,10 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); spin_unlock_bh(&pn->l2tp_tunnel_list_lock); + sk = sock->sk; + sock_hold(sk); + tunnel->sock = sk; + if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { struct udp_tunnel_sock_cfg udp_cfg = { .sk_user_data = tunnel, |