Commit ecd012e4 authored Jun 15, 2018 by Guillaume Nault Committed by David S. Miller Jun 15, 2018

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: d9e31d17 ("l2tp: Add L2TP ethernet pseudowire support")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent de9bada5

net/l2tp/l2tp_ppp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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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