[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: (ITS#8064) SIGSEGV in monitor-shutdown code

Yes, Howard you are right.
In our CI-process 'make test' crashes only for 2.5 branch.
I was noted 2.4 in the ITS, it's my mistake.

To fix this bug seems a de-registration should be provided by monitor-backend.

2015-02-25 17:47 GMT+03:00 Howard Chu <hyc@symas.com>:
> pierangelo.masarati@polimi.it wrote:
>>
>> back-monitor was designed before back-config, without considering the
>> possibility of database removal during regular operations.  There might
>> be several flaws of that kind.
>
>
> Removal is not supported in 2.4. All of that is work-in-progress for 2.5.
> Patches welcome, but this is not a 2.4 bug.
>
>
>> My suggestion is that back-monitor is never shut down (it should be
>> inhibited) except at slapd shutdown.  Meanwhile, the code initialization
>> and shutdown could be redesigned to properly handle those cases.
>>
>> On 25/02/2015 15:18, leo@yuriev.ru wrote:
>>>
>>> Full_Name: Leonid Yuriev
>>> Version: 2.4-HEAD
>>> OS: RHEL7
>>> URL: ftp://ftp.openldap.org/incoming/
>>> Submission from: (NULL) (31.130.36.33)
>>>
>>>
>>> Monitor-backend shutdown code could call a callback from registered
>>> subsystem
>>> after it is already destroyed.
>>>
>>> For instance, currently ldap-backend frees its own registered context
>>> (lmi_mss
>>> from ldap_monitor_info_t) before than monitor_back_db_destroy() will be
>>> called.
>>>
>>> Therefore SIGSEGV would be occur on monitor shutdown if any ldap-backend
>>> database is configured and such freed context will be overwrited.
>>>
>>> This bug could be reproduced by a filling-memory-with-non-zero before
>>> calling
>>> free() from glibc.
>>>
>>>
>>>
>>
>>
>
>
> --
>   -- Howard Chu
>   CTO, Symas Corp.           http://www.symas.com
>   Director, Highland Sun     http://highlandsun.com/hyc/
>   Chief Architect, OpenLDAP  http://www.openldap.org/project/