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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 30CA7C4363A for ; Mon, 5 Oct 2020 20:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC113206CB for ; Mon, 5 Oct 2020 20:59:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725865AbgJEU7Q (ORCPT ); Mon, 5 Oct 2020 16:59:16 -0400 Received: from jabberwock.ucw.cz ([46.255.230.98]:56674 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725861AbgJEU7Q (ORCPT ); Mon, 5 Oct 2020 16:59:16 -0400 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 460E61C0B7C; Mon, 5 Oct 2020 22:59:13 +0200 (CEST) Date: Mon, 5 Oct 2020 22:59:13 +0200 From: Pavel Machek To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Will McVicker , Pablo Neira Ayuso Subject: Re: [PATCH 4.19 38/38] netfilter: ctnetlink: add a range check for l3/l4 protonum Message-ID: <20201005205912.GB27782@amd> References: <20201005142108.650363140@linuxfoundation.org> <20201005142110.510691312@linuxfoundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="4bRzO86E/ozDv8r1" Content-Disposition: inline In-Reply-To: <20201005142110.510691312@linuxfoundation.org> User-Agent: Mutt/1.5.23 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org --4bRzO86E/ozDv8r1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > From: Will McVicker >=20 > commit 1cc5ef91d2ff94d2bf2de3b3585423e8a1051cb6 upstream. >=20 > The indexes to the nf_nat_l[34]protos arrays come from userspace. So > check the tuple's family, e.g. l3num, when creating the conntrack in > order to prevent an OOB memory access during setup. Here is an example > kernel panic on 4.14.180 when userspace passes in an index greater than > NFPROTO_NUMPROTO. Since this protects against OOB array access, should it use _nospec() variant to protect from speculation attacks? Best regards, Pavel > +++ b/net/netfilter/nf_conntrack_netlink.c > @@ -1129,6 +1129,8 @@ ctnetlink_parse_tuple(const struct nlatt > if (!tb[CTA_TUPLE_IP]) > return -EINVAL; > =20 > + if (l3num !=3D NFPROTO_IPV4 && l3num !=3D NFPROTO_IPV6) > + return -EOPNOTSUPP; > tuple->src.l3num =3D l3num; > =20 > err =3D ctnetlink_parse_tuple_ip(tb[CTA_TUPLE_IP], tuple); >=20 --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --4bRzO86E/ozDv8r1 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl97iSAACgkQMOfwapXb+vLMjACfeSXSr3aLcuqvi3ECFUw/TmMO NjMAnRrl6xkIoDP5f9hWcptslinge78f =0g3X -----END PGP SIGNATURE----- --4bRzO86E/ozDv8r1--