This series fixes two bugs: 1. A bug with BTRFS where LSM options are ignored when BTRFS is mounted via the new fsconfig(2) API. (fixed by patch 1) 2. A bug with NFS + SELinux where an attempt to do the same mount twice might incidentally turn off LSM labeling, making any fresh inode show up as unlabeled. (fixed by patch 2, with patch 1 as a prereq) For bug (1.) I previously posted a different patch [1], which is no longer needed if these patches are applied. While these patches do add a new fs_type flag (which seems to be frowned upon), they also reduce the semantics of FS_BINARY_MOUNT_DATA flag to *only* the mount data being binary, while before it was also (ab)used to skip mount option processing in SELinux for NFS and BTRFS. The result is perhaps still not perfect, but it seems to be the only non-invasive solution for these bugs in the short term. Once BTRFS is finally converted to the new mount API, a lot of the ugliness can likely be refactored to something nicer (and these patches do not really make that any harder to do, IMHO). I tested the patches by running the NFS part of the SELinux testsuite [2] (which is now fully passing). I also ran the proposed BTRFS SELinux test coverage for selinux-testsuite [3], which is now passing. Changes since v1: - in BTRFS, move the FS_HANDLES_LSM_OPTS flag to btrfs_root_fs_type, and remove FS_BINARY_MOUNTDATA from both fs_types now v1: https://lore.kernel.org/selinux/20210409111254.271800-1-omosnace@xxxxxxxxxx/T/ [1] https://lore.kernel.org/selinux/20210401065403.GA1363493@xxxxxxxxxxxxx/T/ [2] https://github.com/SELinuxProject/selinux-testsuite/ [3] https://lore.kernel.org/selinux/20201103110121.53919-2-richard_c_haines@xxxxxxxxxxxxxx/ ^^ 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 | 34 +++++----------------------------- fs/nfs/fs_context.c | 6 ++++-- fs/super.c | 10 ++++++---- include/linux/fs.h | 3 ++- security/selinux/hooks.c | 32 +++++++++++++++++--------------- 5 files changed, 34 insertions(+), 51 deletions(-) -- 2.31.1
