l2tp: take remote address into account in l2tp_ip and l2tp_ip6 socket lookups
[ Upstream commit a9b2dff80be979432484afaf7f8d8e73f9e8838a ]
For connected sockets, __l2tp_ip{,6}_bind_lookup() needs to check the
remote IP when looking for a matching socket. Otherwise a connected
socket can receive traffic not originating from its peer.
Drop l2tp_ip_bind_lookup() and l2tp_ip6_bind_lookup() instead of
updating their prototype, as these functions aren't used.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c
index 3468d56..9d77a54 100644
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -48,7 +48,8 @@
return (struct l2tp_ip_sock *)sk;
}
-static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
+static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr,
+ __be32 raddr, int dif, u32 tunnel_id)
{
struct sock *sk;
@@ -62,6 +63,7 @@
if ((l2tp->conn_id == tunnel_id) &&
net_eq(sock_net(sk), net) &&
!(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
+ (!inet->inet_daddr || !raddr || inet->inet_daddr == raddr) &&
(!sk->sk_bound_dev_if || !dif ||
sk->sk_bound_dev_if == dif))
goto found;
@@ -72,15 +74,6 @@
return sk;
}
-static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
-{
- struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
- if (sk)
- sock_hold(sk);
-
- return sk;
-}
-
/* When processing receive frames, there are two cases to
* consider. Data frames consist of a non-zero session-id and an
* optional cookie. Control frames consist of a regular L2TP header
@@ -186,8 +179,8 @@
struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
read_lock_bh(&l2tp_ip_lock);
- sk = __l2tp_ip_bind_lookup(net, iph->daddr, inet_iif(skb),
- tunnel_id);
+ sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr,
+ inet_iif(skb), tunnel_id);
if (!sk) {
read_unlock_bh(&l2tp_ip_lock);
goto discard;
@@ -289,7 +282,7 @@
inet->inet_saddr = 0; /* Use device */
write_lock_bh(&l2tp_ip_lock);
- if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr,
+ if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0,
sk->sk_bound_dev_if, addr->l2tp_conn_id)) {
write_unlock_bh(&l2tp_ip_lock);
ret = -EADDRINUSE;