This is a note to let you know that I've just added the patch titled
l2tp: take remote address into account in l2tp_ip and l2tp_ip6 socket lookups
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: l2tp-take-remote-address-into-account-in-l2tp_ip-and-l2tp_ip6-socket-lookups.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Wed Dec 6 17:39:55 CET 2017
From: Guillaume Nault g.nault@alphalink.fr Date: Fri, 30 Dec 2016 19:48:20 +0100 Subject: l2tp: take remote address into account in l2tp_ip and l2tp_ip6 socket lookups
From: Guillaume Nault g.nault@alphalink.fr
[ 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 --- net/l2tp/l2tp_ip.c | 19 ++++++------------- net/l2tp/l2tp_ip6.c | 20 ++++++-------------- 2 files changed, 12 insertions(+), 27 deletions(-)
--- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -48,7 +48,8 @@ static inline struct l2tp_ip_sock *l2tp_ 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 @@ static struct sock *__l2tp_ip_bind_looku 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 @@ found: 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 @@ pass_up: 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 @@ static int l2tp_ip_bind(struct sock *sk, 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; --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -59,12 +59,14 @@ static inline struct l2tp_ip6_sock *l2tp
static struct sock *__l2tp_ip6_bind_lookup(struct net *net, struct in6_addr *laddr, + const struct in6_addr *raddr, int dif, u32 tunnel_id) { struct sock *sk;
sk_for_each_bound(sk, &l2tp_ip6_bind_table) { const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); + const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
if (l2tp == NULL) @@ -73,6 +75,7 @@ static struct sock *__l2tp_ip6_bind_look if ((l2tp->conn_id == tunnel_id) && net_eq(sock_net(sk), net) && (!sk_laddr || ipv6_addr_any(sk_laddr) || ipv6_addr_equal(sk_laddr, laddr)) && + (!raddr || ipv6_addr_any(sk_raddr) || ipv6_addr_equal(sk_raddr, raddr)) && (!sk->sk_bound_dev_if || !dif || sk->sk_bound_dev_if == dif)) goto found; @@ -83,17 +86,6 @@ found: return sk; }
-static inline struct sock *l2tp_ip6_bind_lookup(struct net *net, - struct in6_addr *laddr, - int dif, u32 tunnel_id) -{ - struct sock *sk = __l2tp_ip6_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 @@ -200,8 +192,8 @@ pass_up: struct ipv6hdr *iph = ipv6_hdr(skb);
read_lock_bh(&l2tp_ip6_lock); - sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, inet6_iif(skb), - tunnel_id); + sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, + inet6_iif(skb), tunnel_id); if (!sk) { read_unlock_bh(&l2tp_ip6_lock); goto discard; @@ -339,7 +331,7 @@ static int l2tp_ip6_bind(struct sock *sk rcu_read_unlock();
write_lock_bh(&l2tp_ip6_lock); - if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, bound_dev_if, + if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, addr->l2tp_conn_id)) { write_unlock_bh(&l2tp_ip6_lock); err = -EADDRINUSE;
Patches currently in stable-queue which might be from g.nault@alphalink.fr are
queue-4.9/l2tp-take-remote-address-into-account-in-l2tp_ip-and-l2tp_ip6-socket-lookups.patch