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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 EE42EC10F07 for ; Wed, 20 Feb 2019 19:35:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD90D2147A for ; Wed, 20 Feb 2019 19:35:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725834AbfBTTfL (ORCPT ); Wed, 20 Feb 2019 14:35:11 -0500 Received: from dgrift.xs4all.space ([80.100.19.56]:50350 "EHLO agnus.defensec.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725847AbfBTTfL (ORCPT ); Wed, 20 Feb 2019 14:35:11 -0500 Received: from localhost (localhost [127.0.0.1]) by agnus.defensec.nl (Postfix) with ESMTP id 4C5122E0566; Wed, 20 Feb 2019 20:35:09 +0100 (CET) X-Virus-Scanned: amavisd-new at defensec.nl Received: from agnus.defensec.nl ([127.0.0.1]) by localhost (agnus.defensec.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id kShBOHooWvu2; Wed, 20 Feb 2019 20:35:07 +0100 (CET) Received: from brutus.lan (brutus.lan [IPv6:2001:985:d55d::438]) by agnus.defensec.nl (Postfix) with ESMTPSA id 2F9732E0165; Wed, 20 Feb 2019 20:35:07 +0100 (CET) Date: Wed, 20 Feb 2019 20:35:06 +0100 From: Dominick Grift To: Stephen Smalley Cc: selinux@vger.kernel.org Subject: Re: [PATCH] scripts/selinux: modernize mdp Message-ID: <20190220193505.GA28292@brutus.lan> References: <20190220123354.1589-1-dominick.grift@defensec.nl> <20190220140922.GA10412@brutus.lan> <20190220144742.GB10412@brutus.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Every email client sucks, this one just sucks less. X-PGP-Key: https://sks-keyservers.net/pks/lookup?op=get&search=0x3B6C5F1D2C7B6B02 Sender: selinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org On Wed, Feb 20, 2019 at 02:25:16PM -0500, Stephen Smalley wrote: > On Wed, Feb 20, 2019 at 2:21 PM Stephen Smalley > wrote: > > > > On Wed, Feb 20, 2019 at 9:48 AM Dominick Grift > > wrote: > > > > > > On Wed, Feb 20, 2019 at 03:09:22PM +0100, Dominick Grift wrote: > > > > On Wed, Feb 20, 2019 at 01:33:54PM +0100, Dominick Grift wrote: > > > > > The MDP example no longer works on modern systems. > > > > > > > > > > Add support for devtmpfs. This is required by login programs to relabel terminals. > > > > > Compile the policy with deny_unknown allow status to anticipate user space object managers in core components such as systemd. > > > > > Add default seusers mapping and failsafe context for the SELinux PAM module. > > > > > > > > There are a couple more possible improvements that i have identified: > > > > > > > > Fail gracefully if checkpolicy does not exist > > > > Run setfiles with -F. There *might* be one scenario where this might be a good idea. Where the filesystem is labeled with invalid contexts but where SELinux is disabled. > > > > In that case setfiles will reset, but only types (I suppose) > > > > > > This also does not make sense to me: > > > > > > if [ -f /sbin/setfiles ]; then > > > SF="/usr/setfiles" > > > > > > I think "-f /usr/setfiles" was meant here? I suppose `which setfiles` only searches "PATH", and so it wouldnt find /usr/setfiles. > > > But then, who uses /usr/setfiles? > > > > No one AFAIK. So I agree that this does not make sense. Might have > > been a broken attempt to support either /sbin/setfiles or > > /usr/sbin/setfiles as the install location of setfiles, since that did > > change at some point. > > Or if as you say it was just an attempt to deal with a PATH that omits > /sbin, then maybe they should both be /sbin/setfiles. We should probably remove those particular file tests altogether? If which does not find it then you have a problem that I am not we want to support? Not to mention that we just dont know the reason for this and what is right or what is wrong? > > > > > > > > > > > > > > > > > > > > Signed-off-by: Dominick Grift > > > > > --- > > > > > scripts/selinux/install_policy.sh | 6 +++++- > > > > > scripts/selinux/mdp/mdp.c | 1 + > > > > > 2 files changed, 6 insertions(+), 1 deletion(-) > > > > > > > > > > diff --git a/scripts/selinux/install_policy.sh b/scripts/selinux/install_policy.sh > > > > > index 0b86c47baf7d..334fcf8903d5 100755 > > > > > --- a/scripts/selinux/install_policy.sh > > > > > +++ b/scripts/selinux/install_policy.sh > > > > > @@ -20,14 +20,18 @@ CP=`which checkpolicy` > > > > > VERS=`$CP -V | awk '{print $1}'` > > > > > > > > > > ./mdp policy.conf file_contexts > > > > > -$CP -o policy.$VERS policy.conf > > > > > +$CP -U allow -o policy.$VERS policy.conf > > > > > > > > > > mkdir -p /etc/selinux/dummy/policy > > > > > mkdir -p /etc/selinux/dummy/contexts/files > > > > > > > > > > +echo "__default__:user_u" > /etc/selinux/dummy/seusers > > > > > +echo "base_r:base_t" > /etc/selinux/dummy/contexts/failsafe_context > > > > > + > > > > > cp file_contexts /etc/selinux/dummy/contexts/files > > > > > cp dbus_contexts /etc/selinux/dummy/contexts > > > > > cp policy.$VERS /etc/selinux/dummy/policy > > > > > + > > > > > FC_FILE=/etc/selinux/dummy/contexts/files/file_contexts > > > > > > > > > > if [ ! -d /etc/selinux ]; then > > > > > diff --git a/scripts/selinux/mdp/mdp.c b/scripts/selinux/mdp/mdp.c > > > > > index 073fe7537f6c..cf06d5694cbc 100644 > > > > > --- a/scripts/selinux/mdp/mdp.c > > > > > +++ b/scripts/selinux/mdp/mdp.c > > > > > @@ -131,6 +131,7 @@ int main(int argc, char *argv[]) > > > > > > > > > > fprintf(fout, "fs_use_trans mqueue user_u:base_r:base_t;\n"); > > > > > fprintf(fout, "fs_use_trans devpts user_u:base_r:base_t;\n"); > > > > > + fprintf(fout, "fs_use_trans devtmpfs user_u:base_r:base_t;\n"); > > > > > fprintf(fout, "fs_use_trans hugetlbfs user_u:base_r:base_t;\n"); > > > > > fprintf(fout, "fs_use_trans tmpfs user_u:base_r:base_t;\n"); > > > > > fprintf(fout, "fs_use_trans shm user_u:base_r:base_t;\n"); > > > > > -- > > > > > 2.21.0.rc1 > > > > > > > > > > > > > -- > > > > Key fingerprint = 5F4D 3CDB D3F8 3652 FBD8 02D5 3B6C 5F1D 2C7B 6B02 > > > > https://sks-keyservers.net/pks/lookup?op=get&search=0x3B6C5F1D2C7B6B02 > > > > Dominick Grift > > > > > > -- > > > Key fingerprint = 5F4D 3CDB D3F8 3652 FBD8 02D5 3B6C 5F1D 2C7B 6B02 > > > https://sks-keyservers.net/pks/lookup?op=get&search=0x3B6C5F1D2C7B6B02 > > > Dominick Grift -- Key fingerprint = 5F4D 3CDB D3F8 3652 FBD8 02D5 3B6C 5F1D 2C7B 6B02 https://sks-keyservers.net/pks/lookup?op=get&search=0x3B6C5F1D2C7B6B02 Dominick Grift