[Samba] winbind filling up log with "Possible deadlock: Trying to lookup SID xxx with passdb backend"

[Andre Fonseca de Oliveira]

On 12/13/2010 11:48 AM, Michael Wood wrote:
> On 13 December 2010 12:38, Andre Fonseca de Oliveira
> <andre.f.oliveira at cgu.gov.br>  wrote:
>> Appreciate your reply.
>>
>>> On 6 December 2010 14:54, Andre Fonseca de Oliveira
>>> <andre.f.oliveira at cgu.gov.br>    wrote:
>>>> Hello,
>>>>
>>>> I have samba 3.3.8 installed on CentOS 5.5 on a production server.
>>>>
>>>> Winbind is filling up the logs with these messages:
>>>>
>>>> [2010/12/06 10:43:28,  0] winbindd/winbindd_passdb.c:sid_to_name(159)
>>>>   Possible deadlock: Trying to lookup SID
>>>> S-1-5-21-2106371596-187675891-3351287853 with passdb backend
>>> If you enable debug level 10, do you get this just before each of
>>> those messages?
>>>
>>> Converting SID S-1-5-21-2106371596-187675891-3351287853
>> Yes. Here is a snippet:
>>
>> [2010/12/13 08:28:59, 10]
>> winbindd/winbindd_dual.c:child_process_request(452)
>>   child_process_request: request fn LOOKUPSID
>> [2010/12/13 08:28:59,  3]
>> winbindd/winbindd_async.c:winbindd_dual_lookupsid(239)
>>   [13229]: lookupsid S-1-5-21-2106371596-187675891-3351287853
>> [2010/12/13 08:28:59, 10] winbindd/winbindd_passdb.c:sid_to_name(147)
>> *Converting SID S-1-5-21-2106371596-187675891-3351287853*
>> [2010/12/13 08:28:59,  0] winbindd/winbindd_passdb.c:sid_to_name(159)
>>   Possible deadlock: Trying to lookup SID
>> S-1-5-21-2106371596-187675891-3351287853 with passdb backend
> OK, so it looks like it's coming from the sid_to_name() function
> (which I should have realised from the line number (159) in the first
> place).
>
>>>> We have been having problems when activating winbind daemon.
>>>>
>>>> Could this error message be causing trouble?
>>> I don't think so.  I'm not sure what would cause this, but the code
>>> logs that message if the SID is not in the BUILTIN domain and is not
>>> in your domain and is not a local user/group and is not a well known
>>> SID (like "Everybody").
>>>
>>> It looks like just a sanity check.  I have no idea what it has to do
>>> with deadlocks, but perhaps someone familiar with the code could
>>> comment.
>>>
>> The SID that appears in the logs is the domain SID:
>>
>> [root at phoenix samba]# net getdomainsid
>> SID for local machine PHOENIX is: S-1-5-21-2106371596-187675891-3351287853
>> SID for domain DF-CGU is: S-1-5-21-2106371596-187675891-3351287853
> Strange.  So instead of the SID being e.g. a user or group, it is the
> domain itself.  That explains why you're getting the message, but not
> why someone is calling sid_to_name() on the domain SID.
>
> I'm out of my depth here.  I don't know if it's normal to call
> sid_to_name() on a domain SID.
>
Well, I guess i will have to live with this message.

Is there a way to supress this error message, besides changing the 
source code?
>>>> Attached is smb.conf globals section (shares removed).
>>>>
>>>> Thanks in advance