Reply To: Authentication failed with error 6

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#2738
AvatarMaccas
Participant

Just to update this – we discussed this further offline and the developers found the issue is because PAM had been configured to enforce membership of the wheel group to allow su usage. /etc/pam.d/su contained:

auth required pam_wheel.so use_uid

The information I received was:

Our user “nx” is not in the wheel group while this PAM configuration requires
that nx is in that group to allow authentication working properly.

We now ship our own /etc/pam.d/nx module which can separate PAM
configuration that is used by NoMachine from the one used by SU service.

So, possible solutions are:

1) Comment out the problematic line in /etc/pam.d/su.

2) If you don’t want to change the su configuration,  please replace the
/etc/pam.d/nx module with the file attached to this mail.

It’s a clean copy of your  “su” configuration file just with the problematic line removed.
In this way you can use a custom policy only for NoMachine and don’t need to change
your “su” configuration.  Feel free to edit the nx file according to your needs.

I wanted this restriction to remain so I created the specific nx module suggested, which contained:

auth            sufficient      pam_rootok.so
auth            include         system-auth
account         sufficient      pam_succeed_if.so uid = 0 use_uid quiet
account         include         system-auth
password        include         system-auth
session         include         system-auth
session         optional        pam_xauth.so

Can’t fault the developers who responded. Excellent support to help troubleshoot this issue.