• Mimi Zohar's avatar
    ima: add appraise action keywords and default rules · 07f6a794
    Mimi Zohar authored
    Unlike the IMA measurement policy, the appraise policy can not be dependent
    on runtime process information, such as the task uid, as the 'security.ima'
    xattr is written on file close and must be updated each time the file changes,
    regardless of the current task uid.
    This patch extends the policy language with 'fowner', defines an appraise
    policy, which appraises all files owned by root, and defines 'ima_appraise_tcb',
    a new boot command line option, to enable the appraise policy.
    Changelog v3:
    - separate the measure from the appraise rules in order to support measuring
      without appraising and appraising without measuring.
    - change appraisal default for filesystems without xattr support to fail
    - update default appraise policy for cgroups
    Changelog v1:
    - don't appraise RAMFS (Dmitry Kasatkin)
    - merged rest of "ima: ima_must_appraise_or_measure API change" commit
      (Dmtiry Kasatkin)
      ima_must_appraise_or_measure() called ima_match_policy twice, which
      searched the policy for a matching rule.  Once for a matching measurement
      rule and subsequently for an appraisal rule. Searching the policy twice
      is unnecessary overhead, which could be noticeable with a large policy.
      The new version of ima_must_appraise_or_measure() does everything in a
      single iteration using a new version of ima_match_policy().  It returns
      With the use of action mask only one efficient matching function
      is enough.  Removed other specific versions of matching functions.
    - change 'owner' to 'fowner' to conform to the new LSM conditions posted by
      Roberto Sassu.
    - fix calls to ima_log_string()
    Signed-off-by: default avatarMimi Zohar <zohar@us.ibm.com>
    Signed-off-by: default avatarDmitry Kasatkin <dmitry.kasatkin@intel.com>
ima_policy 2.49 KB