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

[pierangelo.masarati@polimi.it]

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.

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.
>
>
>


-- 
Pierangelo Masarati
Associate Professor
Dipartimento di Scienze e Tecnologie Aerospaziali
Politecnico di Milano