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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 3536DC433E0 for ; Thu, 14 May 2020 10:12:57 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 92A542065D for ; Thu, 14 May 2020 10:12:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92A542065D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ACULAB.COM Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-18787-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 5624 invoked by uid 550); 14 May 2020 10:12:49 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 5604 invoked from network); 14 May 2020 10:12:49 -0000 X-MC-Unique: y0BDf4GNOjC8TdKy0usypQ-1 From: David Laight To: 'Kees Cook' , Stephen Smalley CC: =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= , linux-kernel , Aleksa Sarai , "Alexei Starovoitov" , Al Viro , "Andy Lutomirski" , Christian Heimes , "Daniel Borkmann" , Deven Bowers , Eric Chiang , Florian Weimer , James Morris , "Jan Kara" , Jann Horn , Jonathan Corbet , Lakshmi Ramasubramanian , Matthew Garrett , Matthew Wilcox , Michael Kerrisk , =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= , Mimi Zohar , =?iso-8859-1?Q?Philippe_Tr=E9buchet?= , "Scott Shell" , Sean Christopherson , Shuah Khan , Steve Dower , Steve Grubb , Thibaut Sautereau , Vincent Strubel , "kernel-hardening@lists.openwall.com" , "linux-api@vger.kernel.org" , "linux-integrity@vger.kernel.org" , LSM List , Linux FS Devel Subject: RE: [PATCH v5 3/6] fs: Enable to enforce noexec mounts or file exec through O_MAYEXEC Thread-Topic: [PATCH v5 3/6] fs: Enable to enforce noexec mounts or file exec through O_MAYEXEC Thread-Index: AQHWKZyBpmhTpEnBl0+f5QrKafolWKinXOJQ Date: Thu, 14 May 2020 10:12:34 +0000 Message-ID: <33eba9f60af54f1585ba82af73be4eb2@AcuMS.aculab.com> References: <20200505153156.925111-1-mic@digikod.net> <20200505153156.925111-4-mic@digikod.net> <202005131525.D08BFB3@keescook> <202005132002.91B8B63@keescook> In-Reply-To: <202005132002.91B8B63@keescook> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable From: Kees Cook > Sent: 14 May 2020 04:05 > On Wed, May 13, 2020 at 04:27:39PM -0700, Kees Cook wrote: > > Like, couldn't just the entire thing just be: > > > > diff --git a/fs/namei.c b/fs/namei.c > > index a320371899cf..0ab18e19f5da 100644 > > --- a/fs/namei.c > > +++ b/fs/namei.c > > @@ -2849,6 +2849,13 @@ static int may_open(const struct path *path, int= acc_mode, int flag) > > =09=09break; > > =09} > > > > +=09if (unlikely(mask & MAY_OPENEXEC)) { > > +=09=09if (sysctl_omayexec_enforce & OMAYEXEC_ENFORCE_MOUNT && > > +=09=09 path_noexec(path)) > > +=09=09=09return -EACCES; > > +=09=09if (sysctl_omayexec_enforce & OMAYEXEC_ENFORCE_FILE) > > +=09=09=09acc_mode |=3D MAY_EXEC; > > +=09} > > =09error =3D inode_permission(inode, MAY_OPEN | acc_mode); > > =09if (error) > > =09=09return error; > > >=20 > FYI, I've confirmed this now. Effectively with patch 2 dropped, patch 3 > reduced to this plus the Kconfig and sysctl changes, the self tests > pass. >=20 > I think this makes things much cleaner and correct. And a summary of that would be right for the 0/n patch email. =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)