Re: (ITS#7968) SIGSEGV shortly after reconnection performed by syncrepl due to synchronization conflicts

[hyc@symas.com]

leo@yuriev.ru wrote:
> Full_Name: Leonid Yuriev
> Version: 2.4.40
> OS: RHEL7
> URL: ftp://ftp.openldap.org/incoming/
> Submission from: (NULL) (31.130.36.33)
>
>
> Currently there is a couple of backtraces only.
> This is the result of a stress test of replication in the presence of
> sync-conflicts after a "split brain" case.
> No any network troubles (just a loopback connections).

Looks like it's accessing freed memory, and it's also related to Abandon 
processing. You might be running into ITS#7967 as well. If you can reproduce 
this, try running with a malloc debugger.
>
> ** Signal 11 (Segmentation fault), address is 0x797a from 0x50e8bd
> (0) /opt/openldap.devel/libexec/slapd() [0x50e8bd]: syncprov_op_abandon
> /home/ly/Projects/openldap.git/servers/slapd/overlays/syncprov.c:1134
> (1) /opt/openldap.devel/libexec/slapd() [0x48b31a]: overlay_op_walk
> /home/ly/Projects/openldap.git/servers/slapd/backover.c:662
> (2) /opt/openldap.devel/libexec/slapd() [0x48b4c1]: over_op_func
> /home/ly/Projects/openldap.git/servers/slapd/backover.c:724
> (3) /opt/openldap.devel/libexec/slapd() [0x4429a7]: fe_op_abandon
> /home/ly/Projects/openldap.git/servers/slapd/abandon.c:134 (discriminator 2)
> (4) /opt/openldap.devel/libexec/slapd() [0x42283c]: connection_abandon
> /home/ly/Projects/openldap.git/servers/slapd/connection.c:740 (discriminator 3)
> (5) /opt/openldap.devel/libexec/slapd() [0x424509]: connection_closing
> /home/ly/Projects/openldap.git/servers/slapd/connection.c:829
> (6) /opt/openldap.devel/libexec/slapd() [0x4250ef]: connection_read
> /home/ly/Projects/openldap.git/servers/slapd/connection.c:1477
> connection_read_thread
> /home/ly/Projects/openldap.git/servers/slapd/connection.c:1284
> (7) /opt/openldap.devel/lib/libldap_r-2.4.so.2(+0x10cf2) [0x7f8c6de89cf2]: ??
>
> *** Signal 11 (Segmentation fault), address is 0x7f7a1e1c5000 from
> 0x7f7a1eebfb54
> (0) /lib/x86_64-linux-gnu/libc.so.6(+0x98b54) [0x7f7a1eebfb54]: ????:0
> (1) /opt/openldap.devel/libexec/slapd() [0x4afa7d]: mdb_search
> /home/ly/Projects/openldap.git/servers/slapd/back-mdb/search.c:987
> (discriminator 3)
> (2) /opt/openldap.devel/libexec/slapd() [0x48b356]: 543edda2 overlay_op_walk
> /home/ly/Projects/openldap.git/servers/slapd/backover.c:674
> (3) /opt/openldap.devel/libexec/slapd() [0x48b4c1]: over_op_func
> /home/ly/Projects/openldap.git/servers/slapd/backover.c:724
> (4) /opt/openldap.devel/libexec/slapd() [0x427201]: fe_op_search
> /home/ly/Projects/openldap.git/servers/slapd/search.c:402
> (5) /opt/openldap.devel/libexec/slapd() [0x426c0c]: do_search
> /home/ly/Projects/openldap.git/servers/slapd/search.c:247
> (6) /opt/openld.d.devel/libexec/slapd() [0x424b54]: connection_operation
> /home/ly/Projects/openldap.git/servers/slapd/connection.c:1158
> (7) /opt/openldap.devel/libexec/slapd() [0x42526c]: connection_read_thread
> /home/ly/Projects/openldap.git/servers/slapd/connection.c:1291
> (8) /opt/openldap.devel/lib/libldap_r-2.4.so.2(+0x10cf2) [0x7f7a1f629cf2]: ??
>
>


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