Re: [PATCH] audit: skip sessionid sentinel value when auto-incrementing

From: Paul Moore
Date: Sun Nov 20 2016 - 15:34:39 EST


On Thu, Nov 17, 2016 at 9:27 PM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> On 2016-11-17 18:34, Paul Moore wrote:
>> On Tue, Nov 15, 2016 at 3:49 AM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
>> > On 2016-11-14 15:17, Paul Moore wrote:
>> >> On Thu, Nov 10, 2016 at 1:41 AM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
>> >> > The value (unsigned int)-1 is used as a sentinel to indicate the
>> >> > sessionID is unset. Skip this value when the session_id value wraps.
>> >> >
>> >> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
>> >> > ---
>> >> > kernel/auditsc.c | 5 ++++-
>> >> > 1 files changed, 4 insertions(+), 1 deletions(-)
>> >>
>> >> Since we haven't merged the session ID kernel patches into audit#next
>> >> yet, why don't you just squash this patch in with the session ID patch
>> >> and resubmit upstream in one nice neat patch.
>> >
>> > This was an existing bug regardless of new functionality added, so the
>> > fix should not be buried in a new feature patch.
>>
>> No, it's not an existing bug. The existing code simply reports/logs
>> the session ID, it doesn't filter on it, so there are no magic values
>> to worry about.
>
> The existing code autoincrements through sessionID==-1. The existing
> code (ausearch and aureport) reports and logs the sessionID and there
> are existing reporting tools that are able to filter on sessionID even
> though kernel filters don't yet exist for them. Therefore, it is
> possible for the counter to roll and to erroneously report that the
> value is unset.

I hadn't realize that the audit userspace was using this as an unset
value. Anyway, merged.

--
paul moore
www.paul-moore.com