On Fri, Dec 9, 2022 at 10:29 AM Paul Moore paul@paul-moore.com wrote:
On Fri, Dec 9, 2022 at 11:05 AM jeffxu@chromium.org wrote:
From: Jeff Xu jeffxu@google.com
The new security_memfd_create allows lsm to check flags of memfd_create.
The security by default system (such as chromeos) can use this to implement system wide lsm to allow only non-executable memfd being created.
Signed-off-by: Jeff Xu jeffxu@google.com Reported-by: kernel test robot lkp@intel.com
include/linux/lsm_hook_defs.h | 1 + include/linux/lsm_hooks.h | 4 ++++ include/linux/security.h | 6 ++++++ mm/memfd.c | 5 +++++ security/security.c | 5 +++++ 5 files changed, 21 insertions(+)
We typically require at least one in-tree LSM implementation to accompany a new LSM hook. Beyond simply providing proof that the hook has value, it helps provide a functional example both for reviewers as well as future LSM implementations. Also, while the BPF LSM is definitely "in-tree", its nature is such that the actual implementation lives out-of-tree; something like SELinux, AppArmor, Smack, etc. are much more desirable from an in-tree example perspective.
Thanks for the comments. Would that be OK if I add a new LSM in the kernel to block executable memfd creation ? Alternatively, it might be possible to add this into SELinux or landlock, it will be a larger change.
Thanks
Jeff
-- paul-moore.com