[Nagios-devel] [Nagios-users] external commands and segfault -- again

Andreas Ericsson ae at op5.se
Mon Jan 8 15:48:50 UTC 2007

David G Schlecht wrote:
> Helmut W. Januschka <h.januschka <at> krone.at> writes:
>> You may move the strlen() to a sperate variable
>> And after that reproduce the gbd session and use "info locales" to see 
>> What are the actual values of the variables and maybe just the strlen fails
>> Also try "print name1" and "print name1[i]" and look if there are some
> unterminated strings 
>> And backtrace to  where the call to the hashfunc2 occurs and have a look at
> the value wich originally gots
>> sended in
>> Maybe its just a old version or a bad implemantion of the tool submitting the
> external command (sure nagios
>> should do a segfault at all ;)) 
> Thanks for your reply, Helmut. From the segfault, it appears that
> both name1 and name2 are corrupt as both are outside the program's
> address space. Since name1 is received as a const, it's unlikely
> that this routine (hashfunc2) is causing the problem. The calling
> routine (find_service) doesn't change the contents of the variable
> so it's not likely the problem. Tracing all the way back,
> event_execution_loop seems the most likely cause of the segfault.
> However this is not a trivial routine and I'm not able to debug it.
> Is there anyone familiar enough with the code available to take a look?
> This problem doesn't occur with each external command, but only
> once every 200-300 times.
> Any help would be most appreciated.

I think you'd have better luck posting this to the nagios-devel list, so 
I'm cross-posting it there now. Provided you're subscribed there, we 
should be able to drop this from the nagios-users list where it really 
doesn't belong.


What command is being sent into the command-pipe when nagios crashes?
Have you made any modifications to the code?
Does this happen with latest CVS code (without any local modifications)?

Andreas Ericsson                   andreas.ericsson at op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

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