Red Hat Bugzilla – Bug 74061
imapd has hardcoded /etc/nologin test -- does not use pam_nologin
Last modified: 2007-04-18 12:46:43 EDT
From Bugzilla Helper: User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0) Description of problem: imapd has a hardcoded test for the presence of the /etc/nologin file, and it denies all client connections if this file exists. This is incorrect behavior, as the test for /etc/nologin should be done using the pam_nologin module. Our problem is that we want a machine which our users cannot log in to, but which will still run an imap server using regular unix accounts and regular home directories. The default settings in /etc/pam.d on 7.3 have pam_nologin in "interactive" style services (such as ssh), but not in /etc/pam.d/system- auth, which is all that /etc/pam.d/imap uses. This is exactly what we want (imap does not use pam_nologin), but we do not obtain the desired behavior because imapd checks itself for the presence of the /etc/nologin file and denies user access if it is found. Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1. touch /etc/nologin 2. chkconfig imap on 3. Use an imap client to try and read mail. Actual Results: The imap client will not be able to connect. It receives a "BYE" disconnect message from the server. Expected Results: The imap client should still be able to connect and read mail, as pam_nologin is not in the /etc/pam.d/imap configuration file. Additional info: The required change appears to be removing the stat at line 256 of src/imapd/imapd.c in the imap-2001a package. The name "/etc/nologin" is hardcoded in src/imapd/Makefile.
Red Hat apologizes that these issues have not been resolved yet. We do want to make sure that no important bugs slip through the cracks. Red Hat Linux 7.3 and Red Hat Linux 9 are no longer supported by Red Hat, Inc. They are maintained by the Fedora Legacy project (http://www.fedoralegacy.org/) for security updates only. If this is a security issue, please reassign to the 'Fedora Legacy' product in bugzilla. Please note that Legacy security update support for these products will stop on December 31st, 2006. If this is not a security issue, please check if this issue is still present in a current Fedora Core release. If so, please change the product and version to match, and check the box indicating that the requested information has been provided. If you are currently still running Red Hat Linux 7.3 or 9, please note that Fedora Legacy security update support for these products will stop on December 31st, 2006. You are strongly advised to upgrade to a current Fedora Core release or Red Hat Enterprise Linux or comparable. Some information on which option may be right for you is available at http://www.redhat.com/rhel/migrate/redhatlinux/. Any bug still open against Red Hat Linux 7.3 or 9 at the end of 2006 will be closed 'CANTFIX'. Again, if this bug still exists in a current release, or is a security issue, please change the product as necessary. We thank you for your help, and apologize again that we haven't handled these issues to this point.
This problem is still present in Fedora Extras 5 in the package uw-imap-2004g-4.fc5.2, but I guess it's really an upstream problem. With the introduction of Dovecot as a replacement IMAP server it's no longer very important.