RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Description of problem:
In RHEL-7.6 mounting a CIFS share takes a long time (54s) to complete. The same mount completes on a RHEL-7.5 system within 3s.

The machine uses SSSD and 'krb5' as 'auth' and 'chpass' provider.  The /etc/krb5.conf contains a list of AD domain controllers.

It turns out that cifs.upcall interferes with the 'kdcinfo' file from the SSSD locator plugin. When this file is in place and 'krb5_use_kdcinfo' is set to 'true' in sssd.conf (which is the default), we see unwanted krb5 kpasswd packets going to the AD DC stored in the 'kdcinfo' file. Removing 'kdcinfo' or setting 'krb5_use_kdcinfo' to 'false' resolves the issue.

Version-Release number of selected component (if applicable):
sssd-1.16.0-19.el7_5.8.x86_64

How reproducible:
Always 

Steps to Reproduce:
1. Configure a RHEL-7.6 machine as AD client using SSSD with 'ldap' as identity provider and 'krb5' as 'auth' and 'chpass' provider
2. Make sure /var/lib/sss/pubconf/kdcinfo.* exists and contains one of the AD DC IP's
3. Mount an AD CIFS share using an AD account with krb5 security options 

Actual results:
It takes very long for the mount to complete.

Expected results:
Mount completes immediately.

Additional info:

In our environment with mount delays and the krb5_use_kdcinfo option...

We experience, as of RHEL 7.6, NFSv4 mount delays of 45 seconds when using sec=sys and 90 seconds when using sec=krb5 to a NetApp NFS server if there isn't already a mount to the server. Doesn't appear to experience the delay automounting homedir directly after a reboot though. But if a umount is performed on said homedir and attempt to remount triggers 45/90 sec mount delay. Always reproducible.

Disabling gssproxy in nfs config is one workaround. Setting 'krb5_use_kdcinfo' to 'false' while keeping gssproxy enabled is another.

Our SSSD config is 'ad' for id_provider and chpass_provider, 'krb5' for auth_provider.

Upstream ticket:
https://pagure.io/SSSD/sssd/issue/3958

* master: 05350ab
* sssd-1-16: 1791eed

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.

https://access.redhat.com/errata/RHSA-2019:2177