mail scanner stuck

[Jim Holland]

On Mon, 17 Apr 2006, Eduardo Casarero wrote:

> Date: Mon, 17 Apr 2006 17:33:54 -0300
> From: Eduardo Casarero <ecasarero at gmail.com>
> Reply-To: MailScanner discussion <mailscanner at lists.mailscanner.info>
> To: MailScanner discussion <mailscanner at lists.mailscanner.info>
> Subject: Re: mail scanner stuck
> 
> hi, after doing some investigation i found the following:
> with 4 particular emails:

> in /var/log/maillog:

Apr 17 16:54:22 avas2 MailScanner[4150]: Virus and Content Scanning: Starting
Apr 17 16:59:23 avas2 MailScanner[4150]: Commercial scanner clamavmodule timed out!
Apr 17 16:59:23 avas2 MailScanner[4150]: Virus Scanning: Denial Of Service attack detected!
-----------------------------------------------------------------------------
> After this last log message the mail scanner rescan of the same email
> looping. This was logged with 1 child runnig (just for debuggin, in 
> normal operation runs 6 childs)

. . . 

> After this i really don´t know what to do. Cause Clamav is the only AV 
> on the system and MScanner has a Timeout for AV of 300 segs an clamav takes
> only 37.24 seg. so MScanner cant see that clamav finished or something 
> is missing.

. . .

This seems to be very similar to the problem I wrote about earlier this 
evening in:

	Subject: Solved? Re: Still stuck in queue, version 4.52.2

I would be very interested to know:

	The size of the message

	What files it contained

	Whether the files were compressed, and if so
	what was the uncompressed file size

	How many messages were in the batch that failed?

Clearly if the message is one of say 30 in a batch then it is going to be
easier for ClamAV to time out on the batch than if there was only one in
the batch.  My understanding is that the timeout setting applies to the
whole batch and not to a single message.

As indicated in my message, I have changed the default for:

	Virus Scanner Timeout =

in MailScanner.conf from 300 to 600 seconds to try to avoid this kind of 
problem.

Regards

Jim Holland
System Administrator
MANGO - Zimbabwe's non-profit e-mail service