From: Steve Grubb <sgrubb@redhat.com>
To: linux-audit@redhat.com
Cc: wmealing <wmealing@redhat.com>, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC] Create an audit record of USB specific details
Date: Mon, 04 Apr 2016 17:37:01 -0400
Message-ID: <4430946.BXbQgWNMDe@x2>
Organization: Red Hat
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On Monday, April 04, 2016 12:02:42 AM wmealing wrote:
> I'm looking to create an audit trail for when devices are added or removed
> from the system.
> 
> The audit subsystem is a logging subsystem in kernel space that can be
> used to create advanced filters on generated events.  It has partnered
> userspace utilities ausearch, auditd, aureport, auditctl which work
> exclusively on audit records.
> 
> These tools are able to set filters to "trigger" on specific in-kernel
> events specified by privileged users.  While the userspace tools can create
> audit events these are not able to be handled intelligently
> (decoded,filtered or ignored) as kernel generated audit events are.
> 
> I have this working at the moment with the USB subsystem (as an example).
> Its been suggested that I use systemd-udev however this means that the audit
> tools (ausearch) will not be able to index these records.
> 
> Here is an example of picking out the AUDIT_DEVICE record type for example.
> 
> > # ausearch -l -i -ts today -m AUDIT_DEVICE
> > ----
> > type=AUDIT_DEVICE msg=audit(31/03/16 16:37:15.642:2) : action=add
> > manufacturer=Linux 4.4.0-ktest ehci_hcd product=EHCI Host Controller
> > serial=0000:00:06.7 major=189 minor=0 bus="usb"

About this event's format...we can't have any spaces in the value side of the 
name=value fields unless its encoded as an untrusted string. You can replace 
spaces with an underscore or dash for readability. So, manufacturer and 
product would need this treatment.

-Steve

> Admittedly this is only the USB device type at the moment, but I'd like to
> break this out into other bus types at some time in the future, gotta start
> somewhere.