Re: Auditd misses accept syscalls from sshd

[Steve Grubb <sgrubb@redhat.com>]

On Saturday, December 3, 2016 2:11:04 AM EST Nathan Cooprider wrote:
> Hi! It sounds like I'm missing something obvious!
> 
> On Fri, Dec 2, 2016 at 5:13 PM Steve Grubb <sgrubb@redhat.com> wrote:
> > Hello,
> > 
> > Addressing a couple obvious things here...
> > 
> > On Friday, December 2, 2016 9:55:17 PM EST Nathan Cooprider wrote:
> > > On Fri, Dec 2, 2016 at 4:09 PM Steve Grubb <sgrubb@redhat.com> wrote:
> > > > On Friday, December 2, 2016 8:43:46 PM EST Nathan Cooprider wrote:
> > > > > Auditd seems to miss accept syscalls from ssh on Ubuntu 14.
> > > > 
> > > > Its not auditd, the kernel does all the work. Auditd acts a lot like a
> > > > specialized syslog.  :-)
> > > > 
> > > > > I tried versions 2.3.2 and 2.4.5 of the daemon
> > 
> > Support was not added until 2.5.
> 
> Support for what?

Audit by executable. In the example that I gave I showed the syntax for how 
you would audit accept only for sshd. I presume that you are not auditing 
accept across the whole system. What rule are you using to audit accept?


> Auditing the accept syscall? What do you mean by "support?" Those are auditd
> versions that I'm talking about. Is that what you mean? Sorry if I was not
> clear. What did it do with accept syscalls before then? I do not see this
> reflected in the changelog

Let's take a look at how you are auditing it and maybe that will explain a few 
things. Also, does Ubuntu 14 use upstart or systemd? And perhaps for good 
measure include just 1 event when it does work.

-Steve 

> https://people.redhat.com/sgrubb/audit/ChangeLog
> 
> > > > with kernel versions 3.13.0-96
> > 
> > Definitely won't support it.
> 
> Support what?
> 
> > > > > and 4.4.0-47.
> > 
> > The feature landed in 4.3, so 4.4 should have it. However, you need audit
> > 2.5
> > or later to use the kernel feature.
> 
> What feature are you talking about? This sounds like it could be the issue,
> but I am not sure to what you are actually referring.
> 
> > >  I just tried again and had the same problem:
> > > vagrant@vagrant:~$ uname -a
> > > Linux vagrant 4.4.0-51-generic #72~14.04.1-Ubuntu SMP Thu Nov 24
> > > 19:22:30
> > > UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
> > 
> > Try pairing that with a newer auditd so that auditctl has the support to
> > load
> > the rule.
> 
> I'll check this out. My initial attempts to compile more recent versions
> than 2.4.5 on the newer kernel in Ubuntu 14 had issues, but those are
> probably personal problems.
> 
> > -Steve
> > 
> > > That's a newer version than I have on my Ubuntu 16 VM, which does
> > > demonstrate the problem. It's also strange that restarting ssh then
> > > makes
> > > the accept syscall events show up. Other sshd syscalls show up in auditd
> > > before and after the ssh restart.