On Wed, Mar 16, 2022 at 11:39 AM Brian J. Murrell <brian@interlinx.bc.ca> wrote:
> Hi,

Hi.

> What OS are running on your system?

EL8.5

Did you tune any default selinux policies?
 

> What is the output of `cat /etc/nsswitch.conf | grep passwd` on your
> system?

passwd:     sss files systemd

You might want to consider:
 - changing the order to: 'files sss ...'
and
 - setting `enable_files_domain = false` (see `man sssd.conf` for details)
 

> Do you use SSSD on purpose?

Yes.  I use FreeIPA here.

Does `getent passwd $your_ipa_use` work for you?
 

So it's not at all surprising to see these /var/lib/sss accesses.  I
just want to understand what they might be for and why nothing is
(apparently) breaking due to the accesses being denied,

Most probably those are lookups (`getpwnam()`, etc) of local users.
When SSSD fails to serve this lookup, it's being served by next source in your nsswitch.conf (i.e. 'files')

 
and if that's a
condition that can continue to happen without there being some future
fall-out.  I.e. what is the result of those accesses being denied
instead of being allowed?

If client app can't connect to the sssd_nss responder socket, then any SSSD lookup should fail...