[PATCH V1] audit: add warning that an old auditd may be starved out by a new auditd

[Paul Moore]

On Wed, Sep 16, 2015 at 6:24 AM, Richard Guy Briggs <rgb at redhat.com> wrote:
> On 15/09/14, Paul Moore wrote:
>> On Sunday, September 13, 2015 12:08:19 PM Richard Guy Briggs wrote:
>> > On 15/09/11, Paul Moore wrote:
>> > > Although I suppose if nothing else we could send a record indicating
>> > > that another auditd attempted to replace it ... if we can send it
>> > > great, drop the new request and be glad we audited it, if we can't
>> > > send it, reset the auditd tracking.
>> >
>> > This is actually a good idea.
>>
>> This would go well with your last patch to try harder on netlink send
>> failures.
>
> Re-looking at the AUDIT_STATUS_PID case, I'm noticing we only
> audit_log_config_change() on success.  At the moment, auditd userspace
> doesn't know about this new AUDIT_PING netlink message type I'm adding
> for testing the health of the existing audit, so it will just be dropped
> by existing auditd.  I think it makes sense to add
> audit_log_config_change() on both the orphaning and starving cases
> indicating the result=0 so that there is a record.  Arguably the
> orphaning case can never happen again since the starving fix will
> prevent a newer auditd from running.

Just so I'm clear, the "starving" case is when a new auditd tries to
evict a perfectly good auditd?

Otherwise, I think adding a result/success field to the
AUDIT_CONFIG_CHANGE record makes sense as long as it doesn't break
Steve's parsing code (I don't think it will, although it may simply
ignore it, which is okay).

-- 
paul moore
www.paul-moore.com