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the product is no longer active in Red Hat Bugzilla.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.
This problem is very difficult to reproduce. It did
happen all the time with the command:
$ su -
The analysis of the code path shows:
if (!(announce & LASTLOG_QUIET)) {
if (last_login.ll_time) {
/* we want the date? */
if (announce & LASTLOG_DATE) {
struct tm *tm, tm_buf;
time_t ll_time;
ll_time = last_login.ll_time;
tm = localtime_r (&ll_time, &tm_buf);
strftime (the_time, sizeof (the_time),
/* TRANSLATORS: "strftime options for date of last login" */
_(" %a %b %e %H:%M:%S %Z %Y"), tm);
The localtime_r call returns NULL, then it pass NULL
to strftime, and crashes.
It should check the return value of localtime_r before
calling strftime.
The user was told to execute:
# sed -e 's/\(pam_lastlog.so.*\)/\1 nodate/g' -i /etc/pam.d/postlogin
that fixed the problem, but more interestingly, after
reverting the sed script change, it continued to work,
so, the problem appears to have been a corrupted
last_login.ll_time, that may have been a corrupted
/var/log/lastlog
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://rhn.redhat.com/errata/RHBA-2016-2314.html
This problem is very difficult to reproduce. It did happen all the time with the command: $ su - The analysis of the code path shows: if (!(announce & LASTLOG_QUIET)) { if (last_login.ll_time) { /* we want the date? */ if (announce & LASTLOG_DATE) { struct tm *tm, tm_buf; time_t ll_time; ll_time = last_login.ll_time; tm = localtime_r (&ll_time, &tm_buf); strftime (the_time, sizeof (the_time), /* TRANSLATORS: "strftime options for date of last login" */ _(" %a %b %e %H:%M:%S %Z %Y"), tm); The localtime_r call returns NULL, then it pass NULL to strftime, and crashes. It should check the return value of localtime_r before calling strftime. The user was told to execute: # sed -e 's/\(pam_lastlog.so.*\)/\1 nodate/g' -i /etc/pam.d/postlogin that fixed the problem, but more interestingly, after reverting the sed script change, it continued to work, so, the problem appears to have been a corrupted last_login.ll_time, that may have been a corrupted /var/log/lastlog