Re: [PATCH ghak90 V9 05/13] audit: log container info of syscalls

[Paul Moore]

On Wed, Oct 21, 2020 at 12:39 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> Here is an exmple I was able to generate after updating the testsuite
> script to include a signalling example of a nested audit container
> identifier:
>
> ----
> type=PROCTITLE msg=audit(2020-10-21 10:31:16.655:6731) : proctitle=/usr/bin/perl -w containerid/test
> type=CONTAINER_ID msg=audit(2020-10-21 10:31:16.655:6731) : contid=7129731255799087104^3333941723245477888
> type=OBJ_PID msg=audit(2020-10-21 10:31:16.655:6731) : opid=115583 oauid=root ouid=root oses=1 obj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 ocomm=perl
> type=CONTAINER_ID msg=audit(2020-10-21 10:31:16.655:6731) : contid=3333941723245477888
> type=OBJ_PID msg=audit(2020-10-21 10:31:16.655:6731) : opid=115580 oauid=root ouid=root oses=1 obj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 ocomm=perl
> type=CONTAINER_ID msg=audit(2020-10-21 10:31:16.655:6731) : contid=8098399240850112512^3333941723245477888
> type=OBJ_PID msg=audit(2020-10-21 10:31:16.655:6731) : opid=115582 oauid=root ouid=root oses=1 obj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 ocomm=perl
> type=SYSCALL msg=audit(2020-10-21 10:31:16.655:6731) : arch=x86_64 syscall=kill success=yes exit=0 a0=0xfffe3c84 a1=SIGTERM a2=0x4d524554 a3=0x0 items=0 ppid=115564 pid=115567 auid=root uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=ttyS0 ses=1 comm=perl exe=/usr/bin/perl subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=testsuite-1603290671-AcLtUulY
> ----
>
> There are three CONTAINER_ID records which need some way of associating with OBJ_PID records.  An additional CONTAINER_ID record would be present if the killing process itself had an audit container identifier.  I think the most obvious way to connect them is with a pid= field in the CONTAINER_ID record.

Using a "pid=" field as a way to link CONTAINER_ID records to other
records raises a few questions.  What happens if/when we need to
represent those PIDs in the context of a namespace?  Are we ever going
to need to link to records which don't have a "pid=" field?  I haven't
done the homework to know if either of these are a concern right now,
but I worry that this might become a problem in the future.

The idea of using something like "item=" is interesting.  As you
mention, the "item=" field does present some overlap problems with the
PATH record, but perhaps we can do something similar.  What if we
added a "record=" (or similar, I'm not worried about names at this
point) to each record, reset to 0/1 at the start of each event, and
when we needed to link records somehow we could add a "related=1,..,N"
field.  This would potentially be useful beyond just the audit
container ID work.

-- 
paul moore
www.paul-moore.com