On 11/04/2013 03:11 PM, hyc@symas.com wrote:

jsynacek@redhat.com wrote:

...

On 10/15/2013 01:10 PM, michael.vishchers@7p-group.com wrote:

...

It is not the client loop that is multithreading but the ldap server.

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.

I modified the reproducer a bit (the start script) and find out a few things. You can find the reproducer I'm using at [1].

Valgrind's helgrind shows some lock problems in the rwm overlay and also in back-ldap and connection.c. After correcting those the issue seems to be gone.

You can find helgrind logs at [2] (before the fix) and [3] (after).

Also, ElectricFence reveals some problems [4], which I didn't fix yet.

A fix attempt can be found at [5]. I'm not sure if that is a correct fix, or it just masked the real issue. But I didn't to manage to reproduce the problem after applying it.

I already explained the problem. The other issues you identified are not relevant, and your patch is not correct. Reread Followup #4 of this ITS.

Another take on the fix:

http://jsynacek.fedorapeople.org/openldap/its7723/0001-ITS-7723-fix-referenc...