From patchwork Mon Sep 28 08:24:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 260045 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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 5DB17C2D0A8 for ; Mon, 28 Sep 2020 08:25:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C97F20774 for ; Mon, 28 Sep 2020 08:25:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726625AbgI1IZB (ORCPT ); Mon, 28 Sep 2020 04:25:01 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:48658 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726601AbgI1IY7 (ORCPT ); Mon, 28 Sep 2020 04:24:59 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 6519120534; Mon, 28 Sep 2020 10:24:57 +0200 (CEST) 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 aoh-EbMeEqPu; Mon, 28 Sep 2020 10:24:56 +0200 (CEST) Received: from mail-essen-02.secunet.de (unknown [10.53.40.205]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 505B7204EF; Mon, 28 Sep 2020 10:24:56 +0200 (CEST) Received: from mbx-essen-01.secunet.de (10.53.40.197) by mail-essen-02.secunet.de (10.53.40.205) with Microsoft SMTP Server (TLS) id 14.3.487.0; Mon, 28 Sep 2020 10:24:56 +0200 Received: from gauss2.secunet.de (10.182.7.193) by mbx-essen-01.secunet.de (10.53.40.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2044.4; Mon, 28 Sep 2020 10:24:55 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 935C13184731; Mon, 28 Sep 2020 10:24:54 +0200 (CEST) From: Steffen Klassert To: David Miller CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 8/8] xfrm: Use correct address family in xfrm_state_find Date: Mon, 28 Sep 2020 10:24:50 +0200 Message-ID: <20200928082450.29414-9-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200928082450.29414-1-steffen.klassert@secunet.com> References: <20200928082450.29414-1-steffen.klassert@secunet.com> MIME-Version: 1.0 X-ClientProxiedBy: cas-essen-02.secunet.de (10.53.40.202) To mbx-essen-01.secunet.de (10.53.40.197) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Herbert Xu The struct flowi must never be interpreted by itself as its size depends on the address family. Therefore it must always be grouped with its original family value. In this particular instance, the original family value is lost in the function xfrm_state_find. Therefore we get a bogus read when it's coupled with the wrong family which would occur with inter- family xfrm states. This patch fixes it by keeping the original family value. Note that the same bug could potentially occur in LSM through the xfrm_state_pol_flow_match hook. I checked the current code there and it seems to be safe for now as only secid is used which is part of struct flowi_common. But that API should be changed so that so that we don't get new bugs in the future. We could do that by replacing fl with just secid or adding a family field. Reported-by: syzbot+577fbac3145a6eb2e7a5@syzkaller.appspotmail.com Fixes: 48b8d78315bf ("[XFRM]: State selection update to use inner...") Signed-off-by: Herbert Xu Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_state.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 5ff392e6f3c1..efc89a92961d 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -1019,7 +1019,8 @@ static void xfrm_state_look_at(struct xfrm_policy *pol, struct xfrm_state *x, */ if (x->km.state == XFRM_STATE_VALID) { if ((x->sel.family && - !xfrm_selector_match(&x->sel, fl, x->sel.family)) || + (x->sel.family != family || + !xfrm_selector_match(&x->sel, fl, family))) || !security_xfrm_state_pol_flow_match(x, pol, fl)) return; @@ -1032,7 +1033,9 @@ static void xfrm_state_look_at(struct xfrm_policy *pol, struct xfrm_state *x, *acq_in_progress = 1; } else if (x->km.state == XFRM_STATE_ERROR || x->km.state == XFRM_STATE_EXPIRED) { - if (xfrm_selector_match(&x->sel, fl, x->sel.family) && + if ((!x->sel.family || + (x->sel.family == family && + xfrm_selector_match(&x->sel, fl, family))) && security_xfrm_state_pol_flow_match(x, pol, fl)) *error = -ESRCH; } @@ -1072,7 +1075,7 @@ xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr, tmpl->mode == x->props.mode && tmpl->id.proto == x->id.proto && (tmpl->id.spi == x->id.spi || !tmpl->id.spi)) - xfrm_state_look_at(pol, x, fl, encap_family, + xfrm_state_look_at(pol, x, fl, family, &best, &acquire_in_progress, &error); } if (best || acquire_in_progress) @@ -1089,7 +1092,7 @@ xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr, tmpl->mode == x->props.mode && tmpl->id.proto == x->id.proto && (tmpl->id.spi == x->id.spi || !tmpl->id.spi)) - xfrm_state_look_at(pol, x, fl, encap_family, + xfrm_state_look_at(pol, x, fl, family, &best, &acquire_in_progress, &error); }