[PATCH v6 3/4] Audit: Add record for multiple task security contexts

[Paul Moore]

On Aug 16, 2025 Casey Schaufler <casey at schaufler-ca.com> wrote:
> 
> Replace the single skb pointer in an audit_buffer with a list of
> skb pointers. Add the audit_stamp information to the audit_buffer as
> there's no guarantee that there will be an audit_context containing
> the stamp associated with the event. At audit_log_end() time create
> auxiliary records as have been added to the list. Functions are
> created to manage the skb list in the audit_buffer.
> 
> Create a new audit record AUDIT_MAC_TASK_CONTEXTS.
> An example of the MAC_TASK_CONTEXTS record is:
> 
>     type=MAC_TASK_CONTEXTS
>     msg=audit(1600880931.832:113)
>     subj_apparmor=unconfined
>     subj_smack=_
> 
> When an audit event includes a AUDIT_MAC_TASK_CONTEXTS record the
> "subj=" field in other records in the event will be "subj=?".
> An AUDIT_MAC_TASK_CONTEXTS record is supplied when the system has
> multiple security modules that may make access decisions based on a
> subject security context.
> 
> Refactor audit_log_task_context(), creating a new audit_log_subj_ctx().
> This is used in netlabel auditing to provide multiple subject security
> contexts as necessary.
> 
> Suggested-by: Paul Moore <paul at paul-moore.com>
> Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
> ---
>  include/linux/audit.h        |  16 +++
>  include/uapi/linux/audit.h   |   1 +
>  kernel/audit.c               | 208 +++++++++++++++++++++++++++++------
>  net/netlabel/netlabel_user.c |   9 +-
>  security/apparmor/lsm.c      |   3 +
>  security/selinux/hooks.c     |   3 +
>  security/smack/smack_lsm.c   |   3 +
>  7 files changed, 202 insertions(+), 41 deletions(-)

Merged into audit/dev, thanks.

--
paul-moore.com