3.16.61-rc1 review patch. If anyone has any objections, please let me know.
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From: Guillaume Nault g.nault@alphalink.fr
commit 7ac6ab1f8a38ba7f8d97f95475bb6a2575db4658 upstream.
l2tp_session_priv() returns a struct pppol2tp_session pointer only for PPPoL2TP sessions. In particular, if the session is an L2TP_PWTYPE_ETH pseudo-wire, l2tp_session_priv() returns a pointer to an l2tp_eth_sess structure, which is much smaller than struct pppol2tp_session. This leads to invalid memory dereference when trying to lock ps->sk_lock.
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 Signed-off-by: Ben Hutchings ben@decadent.org.uk --- net/l2tp/l2tp_ppp.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -756,6 +756,12 @@ static int pppol2tp_connect(struct socke session = l2tp_session_get(sock_net(sk), tunnel, session_id, false); if (session) { drop_refcnt = true; + + if (session->pwtype != L2TP_PWTYPE_PPP) { + error = -EPROTOTYPE; + goto end; + } + ps = l2tp_session_priv(session);
/* Using a pre-existing session is fine as long as it hasn't