Re: [PATCH 0/2] vfs/security/NFS/btrfs: clean up and fix LSM option handling

From: Casey Schaufler <casey@schaufler-ca.com>
To: Ondrej Mosnacek <omosnace@redhat.com>,
	linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
	linux-btrfs@vger.kernel.org, Paul Moore <paul@paul-moore.com>,
	Olga Kornievskaia <aglo@umich.edu>,
	Al Viro <viro@zeniv.linux.org.uk>,
	David Howells <dhowells@redhat.com>,
	Stephen Smalley <stephen.smalley.work@gmail.com>,
	Casey Schaufler <casey@schaufler-ca.com>
Subject: Re: [PATCH 0/2] vfs/security/NFS/btrfs: clean up and fix LSM option handling
Date: Fri, 9 Apr 2021 10:00:43 -0700	[thread overview]
Message-ID: <53c532c8-fecf-ff13-ac82-7755f11a087d@schaufler-ca.com> (raw)
In-Reply-To: <20210409111254.271800-1-omosnace@redhat.com>

On 4/9/2021 4:12 AM, Ondrej Mosnacek wrote:
> This series attempts to clean up part of the mess that has grown around
> the LSM mount option handling across different subsystems.
>
> The original motivation was to fix a NFS+SELinux bug that I found while
> trying to get the NFS part of the selinux-testsuite [1] to work, which
> is fixed by patch 2.
>
> The first patch paves the way for the second one by eliminating the
> special case workaround in selinux_set_mnt_opts(), while also
> simplifying BTRFS's LSM mount option handling.
>
> I tested the patches by running the NFS part of the SELinux testsuite
> (which is now fully passing). I also added the pending patch for
> broken BTRFS LSM options support with fsconfig(2) [2] and ran the
> proposed BTRFS SELinux tests for selinux-testsuite [3] (still passing
> with all patches).

The Smack testsuite can be found at:
	https://github.com/smack-team/smack-testsuite.git

It might provide another layer of confidence.

>
> [1] https://github.com/SELinuxProject/selinux-testsuite/
> [2] https://lore.kernel.org/selinux/20210401065403.GA1363493@infradead.org/T/
> [3] https://lore.kernel.org/selinux/20201103110121.53919-2-richard_c_haines@btinternet.com/
>     ^^ the original patch no longer applies - a rebased version is here:
>     https://github.com/WOnder93/selinux-testsuite/commit/212e76b5bd0775c7507c1996bd172de3bcbff139.patch
>
> Ondrej Mosnacek (2):
>   vfs,LSM: introduce the FS_HANDLES_LSM_OPTS flag
>   selinux: fix SECURITY_LSM_NATIVE_LABELS flag handling on double mount
>
>  fs/btrfs/super.c         | 35 ++++++-----------------------------
>  fs/nfs/fs_context.c      |  6 ++++--
>  fs/super.c               | 10 ++++++----
>  include/linux/fs.h       |  3 ++-
>  security/selinux/hooks.c | 32 +++++++++++++++++---------------
>  5 files changed, 35 insertions(+), 51 deletions(-)
>