[Samba] Bind DNS crashing after upgrade to 4.9.0

[Fabrizio Faganello]

Hi there,

I'm doing some tests upgrading from 4.8.6 to 4.9.0 (and also 4.9.1) and 
I'm having some issues with bind 9.10 in a debian 9 vm.

When Bind is running, if a machine updates, it crashes with the 
following error:

/kernel: [ 7948.941528] named[22947]: segfault at 0 ip 00007ffa89f87a50 
sp 00007ffa8c6588a0 error 6 in 
libdnsserver-common-samba4.so[7ffa89f82000+9000]/

Also, when it's running (before crashing), I neither can enter at DNS 
(nor group policy objects) through RSAT. In log.samba, the following 
errors are logged:

/../lib/util/fault.c:261(log_stack_trace)//
//  BACKTRACE: 45 stack frames://
//   #0 /opt/samba/lib/libsamba-util.so.0(log_stack_trace+0x1f) 
[0x7fef4f1caa75]//
//   #1 /opt/samba/lib/libsamba-util.so.0(+0x1e804) [0x7fef4f1ca804]//
//   #2 /opt/samba/lib/libsamba-util.so.0(log_stack_trace+0) 
[0x7fef4f1caa56]//
//   #3 /opt/samba/lib/libsamba-util.so.0(+0x1e704) [0x7fef4f1ca704]//
//   #4 /opt/samba/lib/libsamba-util.so.0(+0x1e719) [0x7fef4f1ca719]//
//   #5 /lib/x86_64-linux-gnu/libpthread.so.0(+0x110c0) [0x7fef4f43d0c0]//
//   #6 
/opt/samba/lib/libdcerpc-server.so.0(dnsserver_init_zoneinfo+0x451) 
[0x7fef3e553a57]//
//   #7 /opt/samba/lib/libdcerpc-server.so.0(+0x5d8c5) [0x7fef3e54a8c5]//
//   #8 /opt/samba/lib/libdcerpc-server.so.0(+0x641af) [0x7fef3e5511af]//
//   #9 /opt/samba/lib/libdcerpc-server.so.0(+0x64da8) [0x7fef3e551da8]//
//   #10 /opt/samba/lib/libdcerpc-server.so.0(+0x2ab09) [0x7fef3e517b09]//
//   #11 /opt/samba/lib/libdcerpc-server.so.0(+0x2b582) [0x7fef3e518582]//
//   #12 /opt/samba/lib/libdcerpc-server.so.0(+0x2cf1f) [0x7fef3e519f1f]//
//   #13 
/opt/samba/lib/private/libtevent.so.0(_tevent_req_notify_callback+0x6a) 
[0x7fef4e92d2c9]//
//   #14 /opt/samba/lib/private/libtevent.so.0(+0x842a) [0x7fef4e92d42a]//
//   #15 /opt/samba/lib/private/libtevent.so.0(_tevent_req_done+0x25) 
[0x7fef4e92d457]//
//   #16 /opt/samba/lib/libdcerpc-binding.so.0(+0x1d33f) [0x7fef49a5133f]//
//   #17 
/opt/samba/lib/private/libtevent.so.0(_tevent_req_notify_callback+0x6a) 
[0x7fef4e92d2c9]//
//   #18 /opt/samba/lib/private/libtevent.so.0(+0x842a) [0x7fef4e92d42a]//
//   #19 /opt/samba/lib/private/libtevent.so.0(_tevent_req_done+0x25) 
[0x7fef4e92d457]//
//   #20 /opt/samba/lib/private/libsamba-sockets-samba4.so(+0xd092) 
[0x7fef49c6a092]//
//   #21 /opt/samba/lib/private/libsamba-sockets-samba4.so(+0xd2bd) 
[0x7fef49c6a2bd]//
//   #22 
/opt/samba/lib/private/libtevent.so.0(_tevent_req_notify_callback+0x6a) 
[0x7fef4e92d2c9]//
//   #23 /opt/samba/lib/private/libtevent.so.0(+0x842a) [0x7fef4e92d42a]//
//   #24 /opt/samba/lib/private/libtevent.so.0(_tevent_req_done+0x25) 
[0x7fef4e92d457]//
//   #25 /opt/samba/lib/private/libsamba-sockets-samba4.so(+0xc5e3) 
[0x7fef49c695e3]//
//   #26 
/opt/samba/lib/private/libtevent.so.0(_tevent_req_notify_callback+0x6a) 
[0x7fef4e92d2c9]//
//   #27 /opt/samba/lib/private/libtevent.so.0(+0x842a) [0x7fef4e92d42a]//
//   #28 /opt/samba/lib/private/libtevent.so.0(+0x8557) [0x7fef4e92d557]//
//   #29 
/opt/samba/lib/private/libtevent.so.0(tevent_common_invoke_immediate_handler+0x184) 
[0x7fef4e92c212]//
//   #30 
/opt/samba/lib/private/libtevent.so.0(tevent_common_loop_immediate+0x37) 
[0x7fef4e92c318]//
//   #31 /opt/samba/lib/private/libtevent.so.0(+0x1165b) [0x7fef4e93665b]//
//   #32 /opt/samba/lib/private/libtevent.so.0(+0xe113) [0x7fef4e933113]//
//   #33 /opt/samba/lib/private/libtevent.so.0(_tevent_loop_once+0x10f) 
[0x7fef4e92ad66]//
//   #34 
/opt/samba/lib/private/libtevent.so.0(tevent_common_loop_wait+0x25) 
[0x7fef4e92b07d]//
//   #35 /opt/samba/lib/private/libtevent.so.0(+0xe1b5) [0x7fef4e9331b5]//
//   #36 /opt/samba/lib/private/libtevent.so.0(_tevent_loop_wait+0x2b) 
[0x7fef4e92b120]//
//   #37 /opt/samba/lib/process_model/standard.so(+0x25f7) 
[0x7fef41fd45f7]//
//   #38 
/opt/samba/lib/private/libservice-samba4.so(task_server_startup+0x9b) 
[0x7fef4e50980d]//
//   #39 /opt/samba/lib/private/libservice-samba4.so(+0x28c4) 
[0x7fef4e5078c4]//
//   #40 
/opt/samba/lib/private/libservice-samba4.so(server_service_startup+0x166) 
[0x7fef4e507a49]//
//   #41 samba: task[dcesrv](+0x58b6) [0x558b9ae868b6]//
//   #42 samba: task[dcesrv](main+0x3f) [0x558b9ae869b4]//
//   #43 /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf1) 
[0x7fef4c47c2e1]//
//   #44 samba: task[dcesrv](_start+0x2a) [0x558b9ae8456a]//
//[2018/10/30 10:51:18.318452,  0] 
../source4/smbd/process_standard.c:158(standard_child_pipe_handler)//
//  standard_child_pipe_handler: Child 22399 (rpc) terminated with 
signal 6//
//[2018/10/30 12:00:19.324597,  0] 
../source4/dsdb/dns/dns_update.c:330(dnsupdate_nameupdate_done)//
//  ../source4/dsdb/dns/dns_update.c:330: Failed DNS update - with error 
code 110/

I looked for an answer but couldn't find any, I think it's a recent 
problem or I'm doing something wrong...

Sorry if the email is too extensive.

Thanks.