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the product is no longer active in Red Hat Bugzilla.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.
Created attachment 1616227[details]
/etc/named.conf
Description of problem:
BIND 9.9 from RHEL 7.6 behaves like this:
[root@tux ~]# rpm -q bind
bind-9.9.4-72.el7.x86_64
[root@tux ~]#
[root@tux ~]# ss -lpn | grep :53
udp UNCONN 0 0 127.0.0.1:53 *:* users:(("named",pid=1323,fd=513),("named",pid=1323,fd=512))
tcp LISTEN 0 10 127.0.0.1:53 *:* users:(("named",pid=1323,fd=21))
[root@tux ~]#
When now using the exactly same configuration file, BIND 9.11 from RHEL 7.7 behaves like this:
[root@tux ~]# rpm -q bind
bind-9.11.4-9.P2.el7.x86_64
[root@tux ~]#
[root@tux ~]# ss -lpn | grep :53
udp UNCONN 0 0 127.0.0.1:53 *:* users:(("named",pid=1444,fd=513))
udp UNCONN 0 0 :::53 :::* users:(("named",pid=1444,fd=512))
tcp LISTEN 0 10 127.0.0.1:53 *:* users:(("named",pid=1444,fd=22))
tcp LISTEN 0 10 :::53 :::* users:(("named",pid=1444,fd=21))
[root@tux ~]#
While I'm tempted to not call this a "regression" explicitly, because the world needs to use more IPv6 for sure, it still is a undocumented change that must be at least documented in the RHEL 7.7 release notes.
Version-Release number of selected component (if applicable):
bind-9.11.4-9.P2.el7.x86_64
How reproducible:
Always, see above and below.
Steps to Reproduce:
1. Install bind-9.9.4-72.el7.x86_64
2. Use attached configuration file for /etc/named.conf
3. systemctl start named
4. "ss -lpn | grep :53" outputs listening on 127.0.0.1:53
5. Update to bind-9.11.4-9.P2.el7.x86_64
6. Ensure /etc/named.conf configuration file remained unchanged
7. systemctl stop named; systemctl start named
8. "ss -lpn | grep :53" outputs listening on 127.0.0.1:53 AND [::]:53
Actual results:
BIND 9.11 listens on [::]:53 even it isn't configured to do so.
Expected results:
a) Document this new behaviour in the RHEL 7.7 release notes, or alternatively
b) Treat this new behaviour as regression and restore the old behaviour
Additional info:
While it seems a trivial issue, any unintended new listening on [::]:53 might break other daemons like in our use-case where Samba-AD/DC was listening on [::1]:53 which no longer worked because the port was consumed by BIND now.
As a workaround, it is always possible to specify in options:
listen-on-v6 { none; };
It it was intended to be turned off by default. Default action when listen-on-v6 is missing at all should have been not to listen on RHEL 7.
Needs change in bin/named/config.c from any to none.
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-2020:1061
Created attachment 1616227 [details] /etc/named.conf Description of problem: BIND 9.9 from RHEL 7.6 behaves like this: [root@tux ~]# rpm -q bind bind-9.9.4-72.el7.x86_64 [root@tux ~]# [root@tux ~]# ss -lpn | grep :53 udp UNCONN 0 0 127.0.0.1:53 *:* users:(("named",pid=1323,fd=513),("named",pid=1323,fd=512)) tcp LISTEN 0 10 127.0.0.1:53 *:* users:(("named",pid=1323,fd=21)) [root@tux ~]# When now using the exactly same configuration file, BIND 9.11 from RHEL 7.7 behaves like this: [root@tux ~]# rpm -q bind bind-9.11.4-9.P2.el7.x86_64 [root@tux ~]# [root@tux ~]# ss -lpn | grep :53 udp UNCONN 0 0 127.0.0.1:53 *:* users:(("named",pid=1444,fd=513)) udp UNCONN 0 0 :::53 :::* users:(("named",pid=1444,fd=512)) tcp LISTEN 0 10 127.0.0.1:53 *:* users:(("named",pid=1444,fd=22)) tcp LISTEN 0 10 :::53 :::* users:(("named",pid=1444,fd=21)) [root@tux ~]# While I'm tempted to not call this a "regression" explicitly, because the world needs to use more IPv6 for sure, it still is a undocumented change that must be at least documented in the RHEL 7.7 release notes. Version-Release number of selected component (if applicable): bind-9.11.4-9.P2.el7.x86_64 How reproducible: Always, see above and below. Steps to Reproduce: 1. Install bind-9.9.4-72.el7.x86_64 2. Use attached configuration file for /etc/named.conf 3. systemctl start named 4. "ss -lpn | grep :53" outputs listening on 127.0.0.1:53 5. Update to bind-9.11.4-9.P2.el7.x86_64 6. Ensure /etc/named.conf configuration file remained unchanged 7. systemctl stop named; systemctl start named 8. "ss -lpn | grep :53" outputs listening on 127.0.0.1:53 AND [::]:53 Actual results: BIND 9.11 listens on [::]:53 even it isn't configured to do so. Expected results: a) Document this new behaviour in the RHEL 7.7 release notes, or alternatively b) Treat this new behaviour as regression and restore the old behaviour Additional info: While it seems a trivial issue, any unintended new listening on [::]:53 might break other daemons like in our use-case where Samba-AD/DC was listening on [::1]:53 which no longer worked because the port was consumed by BIND now.