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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 D596FC2D0C9 for ; Thu, 12 Dec 2019 17:32:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAF3421655 for ; Thu, 12 Dec 2019 17:32:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730231AbfLLRcZ (ORCPT ); Thu, 12 Dec 2019 12:32:25 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34958 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730061AbfLLRcY (ORCPT ); Thu, 12 Dec 2019 12:32:24 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ifSK3-00027O-P9; Thu, 12 Dec 2019 17:32:19 +0000 Received: from ben by deadeye with local (Exim 4.93-RC7) (envelope-from ) id 1ifSK3-0005J3-82; Thu, 12 Dec 2019 17:32:19 +0000 Message-ID: Subject: Re: [PATCH 4.9 45/47] Smack: Dont ignore other bprm->unsafe flags if LSM_UNSAFE_PTRACE is set From: Ben Hutchings To: Greg Kroah-Hartman Cc: Jann Horn , Casey Schaufler , stable@vger.kernel.org, LKML Date: Thu, 12 Dec 2019 17:32:14 +0000 In-Reply-To: <20191212170649.GA1681017@kroah.com> References: <20191006172016.873463083@linuxfoundation.org> <20191006172019.260683324@linuxfoundation.org> <64c5b8b423774029c3030ae778bf214d36499d2a.camel@decadent.org.uk> <20191212170649.GA1681017@kroah.com> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-5TWjip13pX9rhqBM9tED" User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-5TWjip13pX9rhqBM9tED Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2019-12-12 at 18:06 +0100, Greg Kroah-Hartman wrote: > On Thu, Dec 05, 2019 at 03:50:07PM +0000, Ben Hutchings wrote: > > On Sun, 2019-10-06 at 19:21 +0200, Greg Kroah-Hartman wrote: > > > From: Jann Horn > > >=20 > > > commit 3675f052b43ba51b99b85b073c7070e083f3e6fb upstream. > > [...] > > > --- a/security/smack/smack_lsm.c > > > +++ b/security/smack/smack_lsm.c > > > @@ -949,7 +949,8 @@ static int smack_bprm_set_creds(struct l > > > =20 > > > if (rc !=3D 0) > > > return rc; > > > - } else if (bprm->unsafe) > > > + } > > > + if (bprm->unsafe & ~LSM_UNSAFE_PTRACE) > >=20 > > I think this needs to be ~(LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP) > > for 4.9 and older branches. >=20 > Why? Where did the LSM_UNSAFE_PTRACE_CAP requirement come from (or > really, go away?) LSM_UNSAFE_PTRACE_CAP was combined with LSM_UNSAFE_PTRACE by: commit 9227dd2a84a765fcfef1677ff17de0958b192eda Author: Eric W. Biederman Date: Mon Jan 23 17:26:31 2017 +1300 exec: Remove LSM_UNSAFE_PTRACE_CAP If I understand the patch ("Smack: Dont ignore other bprm->unsafe flags =E2=80=A6") correctly, this function should have one if-statement handling LSM_UNSAFE_PTRACE (and LSM_UNSAFE_PTRACE_CAP if it exists), followed by another if-statement handling all other flags in bprm->unsafe. Ben. --=20 Ben Hutchings Sturgeon's Law: Ninety percent of everything is crap. --=-5TWjip13pX9rhqBM9tED Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEErCspvTSmr92z9o8157/I7JWGEQkFAl3yeZ8ACgkQ57/I7JWG EQlZtA//Vc+1fMfaULjuYh6nSrneMY6YWu/Y5Q1MFJoxEycjb7rMr9CYFyfTa2gK S+SQdPneKD3Aqc7j/nYwdXLC3M8JvSHQHzUMQS6AqB377LPlsHDKEoTkZDv7aTFv g4PP7L2S3JIKGKkehRu63OEVPbBWyXkNcFmVdnzwxF/aH2x1cBcdAeiyK4wa8Ggb 4nIHDH7quI3BMAllYH5bwVrz5K3GF2l/kaEhLEsi/EtYHZ+mgdMhFFDzwBWyiIYU /J4LEUKf85qtDn/8fToactAOW8Q50oMoPlt/apQ/GnzWbUIjlhDq9DCp5wtjdMXW lBhm7W9H8G10lTGeq/hz68WmnWGZT8lMAJ6hqD5wacGTuO2d2JHNrlboLVZWs7RY M3uDgJAUTWebubmFr3eu1dahnDxMPy5OIz2f/hxzHZB9A++4s56WKfHH3X2TZG6m 8gU/57zhLBg3u9LWeR2P4K7IXWqtibfN7dy7qnNO16xhX7pRcCjRqM9YlbSO8Yxs Zxe1HPcUphhiHXt2V3j2fAWk9UPNxFeCEg0T3SMAVlR1+0FfxBS/STDbYnWJV0oq 5vUi+QnJYGE8N6Bcy7yyphubfbfEne9AYzUkwj6+OZcKGxyke4QMbS5wioeTsCJk eyaW/S95ud0OmgJc8rESE8sORgJeyL4Lqq2NWsqFbCqmZxQtJDY= =Halt -----END PGP SIGNATURE----- --=-5TWjip13pX9rhqBM9tED--