l2tp: take PMTU from tunnel UDP socket
[ Upstream commit f34c4a35d87949fbb0e0f31eba3c054e9f8199ba ]
When l2tp driver tries to get PMTU for the tunnel destination, it uses
the pointer to struct sock that represents PPPoX socket, while it
should use the pointer that represents UDP socket of the tunnel.
Signed-off-by: Dmitry Petukhov <dmgenp@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 2211275..4e38a81 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -772,9 +772,9 @@
session->deref = pppol2tp_session_sock_put;
/* If PMTU discovery was enabled, use the MTU that was discovered */
- dst = sk_dst_get(sk);
+ dst = sk_dst_get(tunnel->sock);
if (dst != NULL) {
- u32 pmtu = dst_mtu(__sk_dst_get(sk));
+ u32 pmtu = dst_mtu(__sk_dst_get(tunnel->sock));
if (pmtu != 0)
session->mtu = session->mru = pmtu -
PPPOL2TP_HEADER_OVERHEAD;