4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Nault <g.nault@xxxxxxxxxxxx> [ Upstream commit 97b84fd6d91766ea57dcc350d78f42639e011c30 ] An L2TP socket bound to the unspecified address should match with any address. If not, it can't receive any packet and __l2tp_ip6_bind_lookup() can't prevent another socket from binding on the same device/tunnel ID. While there, rename the 'addr' variable to 'sk_laddr' (local addr), to make following patch clearer. Signed-off-by: Guillaume Nault <g.nault@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/l2tp/l2tp_ip6.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -64,7 +64,7 @@ static struct sock *__l2tp_ip6_bind_look struct sock *sk; sk_for_each_bound(sk, &l2tp_ip6_bind_table) { - const struct in6_addr *addr = inet6_rcv_saddr(sk); + const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); if (l2tp == NULL) @@ -72,7 +72,7 @@ static struct sock *__l2tp_ip6_bind_look if ((l2tp->conn_id == tunnel_id) && net_eq(sock_net(sk), net) && - (!addr || ipv6_addr_equal(addr, laddr)) && + (!sk_laddr || ipv6_addr_any(sk_laddr) || ipv6_addr_equal(sk_laddr, laddr)) && (!sk->sk_bound_dev_if || !dif || sk->sk_bound_dev_if == dif)) goto found;