[CentOS] Update to EL 6.3 breaks TCP NFS automounts

Wed Aug 8 23:25:56 UTC 2012
Cal Webster <cwebster at ec.rr.com>

On Wed, 2012-08-08 at 18:37 -0400, Cal Webster wrote:
> See Red Hat Bugzilla bug #846852 for details.
> https://bugzilla.redhat.com/show_bug.cgi?id=846852
> FYI:
> We discovered that after updating to EL 6.3 on our x86_64 server, autofs
> 5.0.5-54 broke our nightly backups that rely on automounting an NFS
> share hosted on another EL 6 machine on our local network. The machine
> hosting NFS server was configured to allow only TCP connections to the
> port specified by MOUNTD_PORT in "/etc/sysconfig/nfs"
> Any attempts to access this share caused segmentation faults in the
> automount daemon.
> EL 6.2 hosts that had not yet been updated had no problems accessing the
> same NFS shares.
> While testing we found that opening the UDP MOUNTD_PORT on the NFS
> server firewall allowed successful access to the NFS shares from the EL
> 6.3 NFS client without segfault. Closing the port caused the EL 6.3 NFS
> client to return to the faulty behavior.
> On another fully updated EL 6.3 i386 host, we were able to duplicate the
> same symptoms.
> On one of the EL 6.2 hosts not yet updated we confirmed no issues with
> the previous autofs package, then upgraded only autofs. After the
> upgrade we confirmed symptoms identical to the fully updated 6.3
> machines.
> While filing the bug report I found 2 other, possibly related, bugs
> written against autofs 5.0.5-54 that did not describe our symptoms but
> may be relevant to other users on this list.
> Bug 840025 - autofs 5.0.5-54 fails to mount share on IPv6 netapp 
> https://bugzilla.redhat.com/show_bug.cgi?id=840025
> Bug 834641 - autofs requires portmapper on server for NFSv4 mounts 
> https://bugzilla.redhat.com/show_bug.cgi?id=834641
> [Workaround]
> For now, we are leaving the UDP NFS port open on the firewall of the NFS
> server. Our networks are completely isolated from the outside world so
> this doesn't pose a significant risk. However, this may not be
> acceptable for everyone's environment.

I forgot to mention that I did find what appeared to be an identical bug
reported apparently as a private upstream support case #155523. I found
it in a Google search but the link
(https://access.redhat.com/knowledge/solutions/155523) raised a
permission error, even though I was logged into the site. The text-only
cached page from July 24 read like this:

Autofs process segfault on startup after upgrading to RHEL6.3 release.
last modified by Shijoe Panjikkaran on 07/10/12 - 03:26

    Autofs is getting segfaults after upgrading the autofs package to
the 6.3 release
    Automount segfaults with the following message in logs,

automount[5195]: segfault at 28 ip 00007f0dfe22b862 sp 00007f0e01a7b960
error 4 in lookup_hosts.so[7f0dfe222000+1c000]


    Red Hat Enterprise Linux(RHEL) 6.3

This leads me to believe that upstream is aware of this issue and
someone there is working on a fix.