From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69C45C43381 for ; Tue, 5 Mar 2019 07:31:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33AE320657 for ; Tue, 5 Mar 2019 07:31:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727118AbfCEHbU (ORCPT ); Tue, 5 Mar 2019 02:31:20 -0500 Received: from a.mx.secunet.com ([62.96.220.36]:51190 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725909AbfCEHbT (ORCPT ); Tue, 5 Mar 2019 02:31:19 -0500 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 3AEFA201E1; Tue, 5 Mar 2019 08:31:18 +0100 (CET) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3xeTK7WOJRTJ; Tue, 5 Mar 2019 08:31:17 +0100 (CET) Received: from mail-essen-01.secunet.de (mail-essen-01.secunet.de [10.53.40.204]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id C776D2007E; Tue, 5 Mar 2019 08:31:17 +0100 (CET) Received: from gauss2.secunet.de (10.182.7.193) by mail-essen-01.secunet.de (10.53.40.204) with Microsoft SMTP Server id 14.3.439.0; Tue, 5 Mar 2019 08:31:17 +0100 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 5C6F93180F05; Tue, 5 Mar 2019 08:31:17 +0100 (CET) Date: Tue, 5 Mar 2019 08:31:17 +0100 From: Steffen Klassert To: "Su Yanjun " CC: Herbert Xu , , , Subject: Re: [PATCH] net: xfrm: Fix potential oops in xfrm_user_rcv_msg and array out of bounds Message-ID: <20190305073117.GD14737@gauss3.secunet.de> References: <1551671259-21311-1-git-send-email-suyj.fnst@cn.fujitsu.com> <20190305064920.gcpwvkp7yikq33cy@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-G-Data-MailSecurity-for-Exchange-State: 0 X-G-Data-MailSecurity-for-Exchange-Error: 0 X-G-Data-MailSecurity-for-Exchange-Sender: 23 X-G-Data-MailSecurity-for-Exchange-Server: d65e63f7-5c15-413f-8f63-c0d707471c93 X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 X-G-Data-MailSecurity-for-Exchange-Guid: F7486E8E-D8E8-44DE-8ED5-21B0E6A81038 X-G-Data-MailSecurity-for-Exchange-ProcessedOnRouted: True Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 05, 2019 at 03:08:49PM +0800, Su Yanjun wrote: > On 2019/3/5 14:49, Herbert Xu wrote: > > > On Sun, Mar 03, 2019 at 10:47:39PM -0500, Su Yanjun wrote: > > > When i review xfrm_user.c code, i found some potentical bug in it. > > > > > > In xfrm_user_rcvmsg if type parameter from user space is set to > > > XFRM_MSG_MAX or XFRM_MSG_NEWSADINFO or XFRM_MSG_NEWSPDINFO. It will cause > > > xfrm_user_rcv_msg referring to null entry in xfrm_dispatch array. > > > > > > Signed-off-by: Su Yanjun > > > --- > > > net/xfrm/xfrm_user.c | 4 +++- > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c > > > index a131f9f..d832783 100644 > > > --- a/net/xfrm/xfrm_user.c > > > +++ b/net/xfrm/xfrm_user.c > > > @@ -2630,11 +2630,13 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, > > > return -EOPNOTSUPP; > > > type = nlh->nlmsg_type; > > > - if (type > XFRM_MSG_MAX) > > > + if (type >= XFRM_MSG_MAX) > > > return -EINVAL; > > Your patch is wrong. Please check the definition of XFRM_MSG_MAX. > > I see, thanks for your reply. > > type -= XFRM_MSG_BASE; > link = &xfrm_dispatch[type]; > + if (!link) > + return -EOPNOTSUPP; > > Here **link** may refer to null entry for special types such as > XFRM_MSG_MAX or XFRM_MSG_NEWSADINFO or XFRM_MSG_NEWSPDINFO > Am i miss something? 'link' is always a valid pointer into that array.