From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:46778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932387AbeD0N6c (ORCPT ); Fri, 27 Apr 2018 09:58:32 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+4f03bdf92fdf9ef5ddab@syzkaller.appspotmail.com, Guillaume Nault , "David S. Miller" Subject: [PATCH 3.18 15/24] pppoe: check sockaddr length in pppoe_connect() Date: Fri, 27 Apr 2018 15:57:50 +0200 Message-Id: <20180427135632.204591428@linuxfoundation.org> In-Reply-To: <20180427135631.584839868@linuxfoundation.org> References: <20180427135631.584839868@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Nault [ 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: 224cf5ad14c0 ("ppp: Move the PPP drivers") Reported-by: syzbot+4f03bdf92fdf9ef5ddab@syzkaller.appspotmail.com Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ppp/pppoe.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -613,6 +613,10 @@ static int pppoe_connect(struct socket * lock_sock(sk); error = -EINVAL; + + if (sockaddr_len != sizeof(struct sockaddr_pppox)) + goto end; + if (sp->sa_protocol != PX_PROTO_OE) goto end;