sudo with PAM - pam_setcred: Permission denied

[Tom Alsberg]

Hi there.
  
Today I recompiled a new version of sudo - sudo-1.6.5p1 on Linux, with
PAM support. My previous sudo didn't use PAM.

My /etc/pam.d/sudo file has only one rule:
auth    required        pam_unix.so 

When I use sudo, it works just fine, except one thing. I always get
this message after entering my password:
sudo: pam_setcred: Permission denied

My commands are executed normally, everything is fine, except I always
get that message.

I recompiled Linux-PAM (version 0.75) with debugging output enabled,
and it seems that pam_unix's setcred actually returns PAM_SUCCESS, and
not PAM_PERM_DENIED. sudo gets PAM_PERM_DENIED returned, though.
I also tried for a short while replacing the rule in /etc/pam.d/sudo
to:
auth    required        pam_permit.so

As I expected, it gives the same message (and does not ask me for my
password).

So generally pam_unix returns PAM_SUCCESS, but sudo gets
PAM_PERM_DENIED, so PAM itself gets PAM_SUCCESS from pam_unix but
returns PAM_PERM_DENIED, for some reason I couldn't find out.

It also gives the same message when invoking sudo as root.

The system is Linux (heavily modified Slackware 8.0), kernel 2.4.16,
glibc-2.2.3, Linux-PAM-0.75.

  Thank you, any help really appreciated,
  -- Tom

-- 
  Tom Alsberg - certified insane, complete illiterate.
        e-mail: <alsbergt at softhome.net>
	Homepage: http://www.cs.huji.ac.il/~alsbergt/
  * An idea is not responsible for the people who believe in it.