Bug 760109

Summary:	pam_winbind.so prevents users from other auth sources logging in
Product:	Red Hat Enterprise Linux 6	Reporter:	Marko Myllynen <myllynen>
Component:	samba	Assignee:	Guenther Deschner <gdeschner>
Status:	CLOSED ERRATA	QA Contact:	qe-baseos-daemons
Severity:	medium	Docs Contact:
Priority:	medium
Version:	6.2	CC:	asn, azelinka, dpal, gdeschner, prc, sbose, tmraz
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	samba-3.6.8-130.el6	Doc Type:	Bug Fix
Doc Text:	Cause: pam_winbind returned the wrong PAM error code if winbind was not reachable. Consequence: Users were not able to login at all, even if another PAM Module authenticated the user successful. Fix: We always return PAM_USER_UNKNOWN in case winbind had a problem. Result: Users successfully authenticated by another PAM module can login again.	Story Points:	---
Clone Of:
Clones:	859390 (view as bug list)		Environment:
Last Closed:	2013-02-21 08:44:38 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	859390

Description Marko Myllynen 2011-12-05 13:17:58 UTC

Description of problem:
When enabling Winbind and SSSD (or any other PAM module) and configuring Winbind to authenticate from an AD domain and SSSD from non-AD LDAP/Kerberos, pam_winbind.so prevents LDAP/Kerberos users logging in.

In /etc/pam.d/system-auth generated by authconfig there is:

account [default=bad success=ok user_unknown=ignore] pam_sss.so
account [default=bad success=ok user_unknown=ignore] pam_winbind.so

A user authenticated by Winbind is able to login as SSSD correctly ignores the user unknown to it but a user successfully authenticated by SSSD fails to login.

If changing the above to

account [default=bad success=ok user_unknown=ignore] pam_sss.so
account [default=ignore success=ok user_unknown=ignore] pam_winbind.so

then also SSSD authenticated users are able login but it might be better to change pam_winbind.so to honour the user_unknown=ignore parameter (as SSSD does).

Version-Release number of selected component (if applicable):
RHEL 6.2

Comment 2 Tomas Mraz 2011-12-07 12:18:40 UTC

This is interesting - surely pam_winbind should return user_unknown in this case. But also I'd like to know what is returned by pam_winbind.so currently in this situation. If the return value is PAM_IGNORE, authconfig should probably use

account [default=bad success=ok ignore=ignore user_unknown=ignore] pam_sss.so

Comment 4 RHEL Program Management 2012-01-24 23:49:11 UTC

This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux maintenance release. Product Management has 
requested further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed 
products. This request is not yet committed for inclusion in an Update release.

Comment 15 RHEL Program Management 2012-07-10 06:49:59 UTC

This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.

Comment 16 RHEL Program Management 2012-07-11 01:53:34 UTC

This request was erroneously removed from consideration in Red Hat Enterprise Linux 6.4, which is currently under development.  This request will be evaluated for inclusion in Red Hat Enterprise Linux 6.4.

Comment 23 Marko Myllynen 2012-09-26 10:05:25 UTC

I'm happy to confirm that the build samba-3.6.8-130.el6 fixes this issue, thanks!

Comment 24 Guenther Deschner 2012-09-26 10:32:32 UTC

Great! Thanks for verifying!

Comment 27 errata-xmlrpc 2013-02-21 08:44:38 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2013-0338.html