From ddecae8696b96cf56154692298fa4511bc7f70d5 Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Mon, 23 Apr 2018 16:15:14 +0200 Subject: l2tp: check sockaddr length in pppol2tp_connect() [ Upstream commit eb1c28c05894a4b1f6b56c5bf072205e64cfa280 ] Check sockaddr_len before dereferencing sp->sa_protocol, to ensure that it actually points to valid data. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Reported-by: syzbot+a70ac890b23b1bf29f5c@syzkaller.appspotmail.com Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/l2tp/l2tp_ppp.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'net/l2tp') diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index 67f2e72723b2..2764c4bd072c 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -606,6 +606,13 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, lock_sock(sk); error = -EINVAL; + + if (sockaddr_len != sizeof(struct sockaddr_pppol2tp) && + sockaddr_len != sizeof(struct sockaddr_pppol2tpv3) && + sockaddr_len != sizeof(struct sockaddr_pppol2tpin6) && + sockaddr_len != sizeof(struct sockaddr_pppol2tpv3in6)) + goto end; + if (sp->sa_protocol != PX_PROTO_OL2TP) goto end; -- cgit v1.2.3