From ecd012e45ab5fd76ed57546865897ce35920f56b Mon Sep 17 00:00:00 2001
From: Guillaume Nault <g.nault@alphalink.fr>
Date: Fri, 15 Jun 2018 15:39:19 +0200
Subject: [PATCH] l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()
pppol2tp_tunnel_ioctl() can act on an L2TPv3 tunnel, in which case
'session' may be an Ethernet pseudo-wire.
However, pppol2tp_session_ioctl() expects a PPP pseudo-wire, as it
assumes l2tp_session_priv() points to a pppol2tp_session structure. For
an Ethernet pseudo-wire l2tp_session_priv() points to an l2tp_eth_sess
structure instead, making pppol2tp_session_ioctl() access invalid
memory.
Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/l2tp/l2tp_ppp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index f429fed06a1e7..55188382845c3 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -1201,7 +1201,7 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
l2tp_session_get(sock_net(sk), tunnel,
stats.session_id);
- if (session) {
+ if (session && session->pwtype == L2TP_PWTYPE_PPP) {
err = pppol2tp_session_ioctl(session, cmd,
arg);
l2tp_session_dec_refcount(session);
--
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