Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
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.
Previously, if the cgroup pluggable authentication module (PAM) was configured without arguments, the module terminated unexpectedly when opening the session. This update fixes argument processing so that such configuration is handled correctly, which prevents the described crash from occurring.
Description of problem:
If pam_cgroup.so is configured without arguments, it crashes while opening session.
Version-Release number of selected component (if applicable):
libcgroup-0.40.rc1-23.el6
How reproducible:
always
Steps to Reproduce:
$ yum install libcgroup libcgroup-pam openssh-server
$ service cgconfig start
$ service sshd start
# configure sshd to load pam_cgroup.so module without arguments
$ echo "session optional pam_cgroup.so" >> /etc/pam.d/sshd
# try to connect to localhost
$ ssh localhost
Actual results:
Write failed: Broken pipe
sshd[5849]: segfault at 0 ip 00007f2a258beac4 sp 00007ffcff89ff10 error 4 in pam_cgroup.so[7f2a258be000+1000]
Expected results:
successful login, no crash
Additional info:
Found originally in bug #1413904.
Simple workaround is to add an agrument to pam_cgroup.so (any string will prevent the crash, but only "debug" is actually recognized):
session optional pam_cgroup.so debug
The OS license might be $399 or whatever, but the fun of having to reboot a bunch of machines in single user mode to fix pam after applying this update is really priceless.
You knew about this bug more than a month before the broken libcgroup got released in 6.9, and didn't do anything about it? Didn't mark it as a blocker? STILL didn't release a fix for it, 2 months after the busted release? That's just unconscionable.
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/RHBA-2018:1861