[0/7] ima/evm: Small enhancements

Message

Roberto Sassu April 9, 2021, 11:43 a.m. UTC

This patch set provides some small enhancements for IMA and EVM.

Patch 1 avoids measurement and audit when access to the file will be denied
by IMA itself.

Patch 2 introduces a new policy keyword meta_immutable to protect the label
transition during binary execution.

Patch 3-5 add new hard-coded policies aiming at producing measurement or
enforcing access to files that likely are provided by software vendors.

Patch 6 increases the crypto resistance of EVM by allowing the choice of
the hash algorithm for the HMAC.

Patch 7 adds two new values for the evm= option in the kernel command line
to facilitate the setup of EVM.

Roberto Sassu (7):
  ima: Avoid measurement and audit if access to the file will be denied
  ima: Add meta_immutable appraisal type
  ima: Introduce exec_tcb and tmpfs policies
  ima: Introduce appraise_exec_tcb and appraise_tmpfs policies
  ima: Introduce appraise_exec_immutable policy
  evm: Allow choice of hash algorithm for HMAC
  evm: Extend evm= with allow_metadata_writes and complete values

 Documentation/ABI/testing/ima_policy          |  2 +-
 .../admin-guide/kernel-parameters.txt         | 36 +++++++-
 security/integrity/evm/Kconfig                | 34 +++++++
 security/integrity/evm/evm.h                  |  2 +
 security/integrity/evm/evm_crypto.c           | 55 ++++++++++--
 security/integrity/evm/evm_main.c             | 29 ++++--
 security/integrity/ima/ima_appraise.c         |  9 ++
 security/integrity/ima/ima_main.c             | 20 +++--
 security/integrity/ima/ima_policy.c           | 90 ++++++++++++++-----
 security/integrity/integrity.h                |  4 +-
 10 files changed, 232 insertions(+), 49 deletions(-)