Re: (ITS#7723) slapd crashes on multi core machines if a search request is *immediately* followed by an unbind

[hyc@symas.com]

michael.vishchers@7p-group.com wrote:
> --_004_96779DE2D69B3E4DB46CA3AEAA8C409D8B0DCCRTGMX02intranetlo_
> Content-Type: multipart/alternative;
> 	boundary="_000_96779DE2D69B3E4DB46CA3AEAA8C409D8B0DCCRTGMX02intranetlo_"
>
> --_000_96779DE2D69B3E4DB46CA3AEAA8C409D8B0DCCRTGMX02intranetlo_
> Content-Type: text/plain; charset="iso-8859-1"
> Content-Transfer-Encoding: quoted-printable
>
> It is not the client loop that is multithreading but the ldap server.

Thanks for clarifying.
>
> And it is not a misuse of the API but a problem that may be raised by day t=
> o day network problems.
>
> I've boiled down the problem to a few simple configurations that work (or b=
> etter, fail ;-) with both 2.4.23 and 2.4.36. A tgz file containing a setup =
> with start script and testclient is attached. It should be sufficient to re=
> produce the fault.
>
> The problem occurs only if we use session variable substitution in the rwm =
> overlay, and only if a search is *immediately* (e.g. caused by network loss=
>   and client timeout) followed by an unbind.

Yes, your test config shows that the problem is that rwm_conn_destroy frees 
the session context while rwm_op_search is using it. Seems like the rwm 
overlay is not doing reference counting properly.

-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/