EVM verifies the existing 'security.evm' value, before allowing it
to be updated.  The EVM HMAC and the original file signatures contain
filesystem specific metadata (e.g. i_ino, i_generation and s_uuid).

This poses a challenge when transitioning from the lower backing file
to the upper backing file.

Until a complete solution is developed, disable EVM on overlayfs.

Mimi Zohar (2):
  evm: don't copy up 'security.evm' xattr
  evm: add support to disable EVM on unsupported filesystems

 include/linux/evm.h               |  6 +++++
 security/integrity/evm/evm_main.c | 42 ++++++++++++++++++++++++++++++-
 security/security.c               |  4 +++
 3 files changed, 51 insertions(+), 1 deletion(-)

-- 
2.39.3