pppoe: check sockaddr length in pppoe_connect()

[ Upstream commit a49e2f5d5fb141884452ddb428f551b123d436b5 ]

We must validate sockaddr_len, otherwise userspace can pass fewer data
than we expect and we end up accessing invalid data.

Fixes: 224cf5ad14 ("ppp: Move the PPP drivers")
Reported-by: syzbot+4f03bdf92fdf9ef5ddab@syzkaller.appspotmail.com
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Guillaume Nault 2018-04-23 16:38:27 +02:00 committed by Greg Kroah-Hartman
parent 183f20fb01
commit dedf29a064

View File

@ -638,6 +638,10 @@ 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;