Re: [PATCH v4 0/3] dm: audit event logging

From: Steve Grubb
Date: Wed Sep 08 2021 - 11:39:54 EST


On Wednesday, September 8, 2021 9:16:16 AM EDT Richard Guy Briggs wrote:
> Another minor oddity is the double "=" for the subj
>
> > > field, which doesn't appear to be a bug in your code, but still
> > > puzzling.
> >
> > In the test setup, I had Apparmor enabled and set as default security
> > module. This behavior occurs in any audit_log message.
> > Seems that this is coming from the label handling there. Having a quick
> > look at the code there is that they use '=' in the label to provide a
> > root view as part of their policy virtualization. The corresponding
> > commit is sitting there since 2017:
> > "26b7899510ae243e392960704ebdba52d05fbb13"
>
> Interesting... Thanks for tracking down that cause. I don't know how
> much pain that will cause the userspace parsing tools. I've added Steve
> Grubb to the Cc: to get his input, but this should not derail this patch
> set.

It likely breaks any parser. I would even say that it's a malformed event
that should be corrected. There's been a published a specification for audit
events for at least 5 years. Latest copy is here:

https://github.com/linux-audit/audit-documentation/wiki/SPEC-Writing-Good-Events

-Steve