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Contribs.org Forums => Koozali SME Server 10.x => Topic started by: mauro on August 03, 2021, 10:22:54 AM

Title: cvm-unix segfault
Post by: mauro on August 03, 2021, 10:22:54 AM

SME10
Every about 30 min I get this in /var/log/messages:

Code: [Select]

Aug  3 08:06:35 wintermute kernel: [216543.570193] cvm-unix[13482]: segfault at 0 ip 00007fefe53e9ec6 sp 00007fff8eec3bc8 error 4 in libc-2.17.so[7fefe52ab000+1c4000]
Is it 'normal' log noise or should I open a bug?

Title: Re: cvm-unix segfault
Post by: Jean-Philippe Pialasse on August 03, 2021, 01:07:23 PM

from memory already reported and seems related to trial to auth an account without password defined /locked

you can check time in this error and in qpsmtpd/sqpsmtpd logs

Title: Re: cvm-unix segfault
Post by: mauro on August 03, 2021, 02:39:22 PM

Indeed that is the case.
I see in sqpsmtpd continuous attempts to auth non-existing users. The user names seem to come from a dictionary. Whenever by chance one of this user names matches the name of an existing group in the server, I get the segfault.
I'm thinking to install fail2ban contrib.

Title: Re: cvm-unix segfault
Post by: Jean-Philippe Pialasse on August 03, 2021, 06:18:04 PM

stop thinking. do it ;)

Title: Re: cvm-unix segfault
Post by: ReetP on August 03, 2021, 06:41:37 PM

Quote from: Jean-Philippe Pialasse on August 03, 2021, 06:18:04 PM

stop thinking. do it ;)

:lol:

Title: Re: cvm-unix segfault
Post by: RDMidtun on September 28, 2021, 08:36:46 PM

Quote from: mauro on August 03, 2021, 10:22:54 AM

SME10
Every about 30 min I get this in /var/log/messages:

Code: [Select]

Aug  3 08:06:35 wintermute kernel: [216543.570193] cvm-unix[13482]: segfault at 0 ip 00007fefe53e9ec6 sp 00007fff8eec3bc8 error 4 in libc-2.17.so[7fefe52ab000+1c4000]
Is it 'normal' log noise or should I open a bug?

I had the same problem and installed fail2ban to see if lowering the load on the cvm-unix service would fix the problem. But, no success, I still had a segfault every half an hour or so causing the cvm-unix service to restart. Since the module is used to authenticate users for the mail system, I tried to change the email setting "SMTP authentication" from "Allow both SMTP and SSMTP" to "Allow SMTP" only. This fixed the problem! Since making the change a few days back, I have not seen any cvm-unix segfault in  the /var/log/messages file.

Title: Re: cvm-unix segfault
Post by: Jean-Philippe Pialasse on September 28, 2021, 10:05:15 PM

fail2ban will not prevent any occurrence but could lower by baning offending ip.

preventing auth on smtp port is an idea, please do so if not an issue for you, but you might prevent user behind a firewall to send mail. sometimes smtps port is filtered by firewalls.

Title: Re: cvm-unix segfault
Post by: Mace on September 29, 2021, 07:06:40 AM

Also if using fail2ban see https://forums.contribs.org/index.php/topic,54609.msg286443.html#msg286443 as it's service fails to start when a reconfig and reboot is executed at the moment.

Title: Re: cvm-unix segfault
Post by: ReetP on September 29, 2021, 09:07:07 AM

Yes we know.

More accurately see this and the relevant bugs.

https://forums.contribs.org/index.php/topic,54609.msg286445.html#msg286445

It's an irritation, but not a reason to not use it.

Title: Re: cvm-unix segfault
Post by: ReetP on August 11, 2023, 02:15:46 PM

This should be fixed in smeserver-qpsmtpd.noarch 0:2.7.0-12.el7.sme which was released a few days ago.

Please let us know if you have any issues.