Fwd: Mailscanner child freezes

Glenn Steen glenn.steen at gmail.com
Sat Nov 22 09:58:13 GMT 2008


2008/11/21 Scott Silva <ssilva at sgvwater.com>:
> on 11-21-2008 7:10 AM Glenn Steen spake the following:
>> Guys,
>>
>> I know my quoting style will drive you nuts, but ... please look at this.
>> It's a heads up for 4.72.5, keep a lookout for children busy-looping
>> while "cleaning messages".
>> Hopefully Jules, or one of you, will have a solution ... really quick.
>>
>> Cheers
>> -- Glenn
>>
> Glenn,
> If you have a sample of this available, I can run it through my sendmail box
> and see if it is only postfix related or deeper.
>
The trouble is in Message.pm, so it probably affects all. You can
easily create a testcase yourself:
zip any file into an archive called "archive.zip" (or whatever you
like:-), then zip "archive.zip" into a new zip file named
"archive.zip"... then send it through .... Keep an eye on top and
you'll see one MS child "get stuck" in "cleaning messages" eating
close to 100% CPU.
This bug only affect 4.72.5 (and later, from what it seems ... from
reading the code), so all who run 4.71 are unaffected.

Since this is easily and readily exploitable, I hesitated "going
public" with this... I'm looking at finding a solution (it should be
something simple, either safeguarding when constructing the hashes, or
"loop-detecting" when travesing the "hash list"), but as always...
Jules genius (and superior understanding of all nuances of the code)
would likely find a simple solution to this in no time at all:-).

I'd appreciate if you did do a test Scott.

Cheers
-- 
-- Glenn
email: glenn < dot > steen < at > gmail < dot > com
work: glenn < dot > steen < at > ap1 < dot > se


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