From a49e2f5d5fb141884452ddb428f551b123d436b5 Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Mon, 23 Apr 2018 16:38:27 +0200 Subject: pppoe: check sockaddr length in pppoe_connect() We must validate sockaddr_len, otherwise userspace can pass fewer data than we expect and we end up accessing invalid data. Fixes: 224cf5ad14c0 ("ppp: Move the PPP drivers") Reported-by: syzbot+4f03bdf92fdf9ef5ddab@syzkaller.appspotmail.com Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller --- drivers/net/ppp/pppoe.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c index 1483bc7b01e1..7df07337d69c 100644 --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -620,6 +620,10 @@ static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr, lock_sock(sk); error = -EINVAL; + + if (sockaddr_len != sizeof(struct sockaddr_pppox)) + goto end; + if (sp->sa_protocol != PX_PROTO_OE) goto end; -- cgit v1.2.3-59-g8ed1b