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the product is no longer active in Red Hat Bugzilla.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.
To setup the problem, edit /etc/nsswith.conf and add 'db' first, for example
-passwd files sss
+passwd db files sss
Then, this example program will crash if setpwent is not called:
"""
#include <stdio.h>
#include <sys/types.h>
#include <pwd.h>
#include <grp.h>
void main()
{
int usercnt;
int grpcnt;
struct passwd *p;
// setpwent(); not absolutely required but good practice
p = getpwent();
for(usercnt = 0; p; p = getpwent(), usercnt++);
endpwent();
// setpwent(); if uncomment it the code does not segfault
p = getpwent();
for(usercnt = 0; p; p = getpwent(), usercnt++) {
printf("%s (%d)\tHOME %s\tSHELL %s\n", p->pw_name, p->pw_uid, p->pw_dir, p->pw_shell);
}
setpwent();
}
"""
If not using passwd.db apparently the default behaviour is to have
endpwent to implicitly rewind, so, setpwent is somewhat useless other
than when using a database.
Is the crash (due to reading past the end of the stream) expected?
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-2020:0989
To setup the problem, edit /etc/nsswith.conf and add 'db' first, for example -passwd files sss +passwd db files sss Then, this example program will crash if setpwent is not called: """ #include <stdio.h> #include <sys/types.h> #include <pwd.h> #include <grp.h> void main() { int usercnt; int grpcnt; struct passwd *p; // setpwent(); not absolutely required but good practice p = getpwent(); for(usercnt = 0; p; p = getpwent(), usercnt++); endpwent(); // setpwent(); if uncomment it the code does not segfault p = getpwent(); for(usercnt = 0; p; p = getpwent(), usercnt++) { printf("%s (%d)\tHOME %s\tSHELL %s\n", p->pw_name, p->pw_uid, p->pw_dir, p->pw_shell); } setpwent(); } """ If not using passwd.db apparently the default behaviour is to have endpwent to implicitly rewind, so, setpwent is somewhat useless other than when using a database. Is the crash (due to reading past the end of the stream) expected?