Commit eb1c28c0 authored Apr 23, 2018 by Guillaume Nault Committed by David S. Miller Apr 23, 2018

l2tp: check sockaddr length in pppol2tp_connect()



Check sockaddr_len before dereferencing sp->sa_protocol, to ensure that
it actually points to valid data.

Fixes: fd558d18 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Reported-by:  <syzbot+a70ac890b23b1bf29f5c@syzkaller.appspotmail.com>
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent b6a930fa

net/l2tp/l2tp_ppp.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -619,6 +619,13 @@ 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;

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