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

[Ondrej Mosnacek]

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).

[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(-)

-- 
2.30.2