[PATCH net] ip6_tunnel: fix ip6_tnl_lookup

[PATCH net] ip6_tunnel: fix ip6_tnl_lookup

[Vadim Fedorenko]

The commit ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel
endpoints.") introduces support for wildcards in tunnels endpoints,
but in some rare circumstances ip6_tnl_lookup selects wrong tunnel
interface relying only on source or destination address of the packet
and not checking presence of wildcard in tunnels endpoints. Later in
ip6_tnl_rcv this packets can be dicarded because of difference in
ipproto even if fallback device have proper ipproto configuration.

This patch adds checks of wildcard endpoint in tunnel avoiding such
behavior

Fixes: ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel
endpoints.")

Signed-off-by: Vadim Fedorenko <junk@yandex-team.ru>
---
 net/ipv6/ip6_tunnel.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 6a66adb..5692d6b 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -157,6 +157,7 @@ ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_
 	hash = HASH(&any, local);
 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 		if (ipv6_addr_equal(local, &t->parms.laddr) &&
+		    ipv6_addr_any(&t->parms.raddr) &&
 		    (t->dev->flags & IFF_UP))
 			return t;
 	}
@@ -164,6 +165,7 @@ ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_
 	hash = HASH(remote, &any);
 	for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 		if (ipv6_addr_equal(remote, &t->parms.raddr) &&
+		    ipv6_addr_any(&t->parms.laddr) &&
 		    (t->dev->flags & IFF_UP))
 			return t;
 	}
-- 
1.9.1

Re: [PATCH net] ip6_tunnel: fix ip6_tnl_lookup

[David Miller]

From: Vadim Fedorenko <junk@yandex-team.ru>
Date: Tue, 11 Oct 2016 22:47:20 +0300

> The commit ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel
> endpoints.") introduces support for wildcards in tunnels endpoints,
> but in some rare circumstances ip6_tnl_lookup selects wrong tunnel
> interface relying only on source or destination address of the packet
> and not checking presence of wildcard in tunnels endpoints. Later in
> ip6_tnl_rcv this packets can be dicarded because of difference in
> ipproto even if fallback device have proper ipproto configuration.
> 
> This patch adds checks of wildcard endpoint in tunnel avoiding such
> behavior
> 
> Fixes: ea3dc9601bda ("ip6_tunnel: Add support for wildcard tunnel
> endpoints.")
> 
> Signed-off-by: Vadim Fedorenko <junk@yandex-team.ru>

Applied and queued up for -stable.