Re: [PATCH] audit: add containerid support for IMA-audit

[Richard Guy Briggs]

On 2018-05-18 08:53, Mimi Zohar wrote:
> On Fri, 2018-05-18 at 07:49 -0400, Stefan Berger wrote:
> > On 05/17/2018 05:30 PM, Richard Guy Briggs wrote:
> 
> [...]
> 
> > >>> auxiliary record either by being converted to a syscall auxiliary record
> > >>> by using current->audit_context rather than NULL when calling
> > >>> audit_log_start(), or creating a local audit_context and calling
> > >> ima_parse_rule() is invoked when setting a policy by writing it into
> > >> /sys/kernel/security/ima/policy. We unfortunately don't have the
> > >> current->audit_context in this case.
> > > Sure you do.  What process writes to that file?  That's the one we care
> > > about, unless it is somehow handed off to a queue and processed later in
> > > a different context.
> > 
> > I just printk'd it again. current->audit_context is NULL in this case.
> 
> The builtin policy rules are loaded at __init.  Subsequently a custom
> policy can replace the builtin policy rules by writing to the
> securityfs file.  Is the audit_context NULL in both cases?

I wondered the same.

> > >> If so, which ones? We could probably refactor the current
> > >> integrity_audit_message() and have ima_parse_rule() call into it to get
> > >> those fields as well. I suppose adding new fields to it wouldn't be
> > >> considered breaking user space?
> > > Changing the order of existing fields or inserting fields could break
> > > stuff and is strongly discouraged without a good reason, but appending
> > > fields is usually the right way to add information.
> > >
> > > There are exceptions, and in this case, I'd pick the "more standard" of
> > > the formats for AUDIT_INTEGRITY_RULE (ima_audit_measurement?) and stick
> > > with that, abandoning the other format, renaming the less standard
> > > version of the record (ima_parse_rule?) and perhpas adopting that
> > > abandonned format for the new record type while using
> > > current->audit_context.
> 
> This sounds right, other than "type=INTEGRITY_RULE" (1805) for
> ima_audit_measurement().  Could we rename type=1805 to be
> INTEGRITY_AUDIT or INTEGRITY_IMA_AUDIT?  The new type=1806 audit
> message could be named INTEGRITY_RULE or, if that would be confusing,
> INTEGRITY_POLICY_RULE.

I'm reluctant to change the macro/value.  Just use the existing
AUDIT_INTEGRITY_RULE        1805 as appropriate and create a new
AUDIT_INTEGRITY_AUDIT       1806.

> > 1806 would be in sync with INTEGRITY_RULE now for process related info. 
> > If this looks good, I'll remove the dependency on your local context 
> > creation and post the series.
> > 
> > The justification for the change is that the INTEGRITY_RULE, as produced 
> > by ima_parse_rule(), is broken.
> 
> Post which series?  The IMA namespacing patch set?  This change should
> be upstreamed independently of IMA namespacing.
> 
> Mimi
> 

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635