smbd frequently crashes in _wkssvc_NetWkstaEnumUsers

Issue

We are facing frequent smbd crashes on their production box, It seems the crash occurs in every 30 minutes.
Backtrace from the core file generated by smbd.

#0  0x00007f02396648a5 in raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007f0239666085 in abort () at abort.c:92
#2  0x00007f023cce2e31 in dump_core () at lib/fault.c:391
#3  0x00007f023ccf2869 in smb_panic (why=<value optimized out>) at lib/util.c:1133
#4  0x00007f023cce32b4 in fault_report (sig=11) at lib/fault.c:53
#5  sig_fault (sig=11) at lib/fault.c:76
#6  <signal handler called>
#7  0x00007f023cb61844 in _wkssvc_NetWkstaEnumUsers (p=<value optimized out>, r=<value optimized out>)  at rpc_server/wkssvc/srv_wkssvc_nt.c:591
#8  0x00007f023cb606f7 in api_wkssvc_NetWkstaEnumUsers (p=0x7f023e84baf0) at librpc/gen_ndr/srv_wkssvc.c:209
#9  0x00007f023cbe54b6 in api_rpcTNP (p=0x7f023e84baf0, pkt=0x7f023e843ed0, api_rpc_cmds=0x7f023d4689c0,   n_cmds=<value optimized out>) at rpc_server/srv_pipe.c:1647
#10 0x00007f023cbe672f in api_pipe_request (p=0x7f023e84baf0) at rpc_server/srv_pipe.c:1580
#11 process_request_pdu (p=0x7f023e84baf0) at rpc_server/srv_pipe.c:1837
#12 process_complete_pdu (p=0x7f023e84baf0) at rpc_server/srv_pipe.c:1894
#13 0x00007f023cbe7ea8 in process_incoming_data (p=0x7f023e84baf0, data=0x7f023e85d020 "D", n=<value optimized out>)  at rpc_server/srv_pipe_hnd.c:218
#14 0x00007f023cbe8341 in write_to_internal_pipe (mem_ctx=<value optimized out>, ev=0x7f023e82d4f0, handle=<value optimized out>,   data=<value optimized out>, len=92) at rpc_server/srv_pipe_hnd.c:244
#15 np_write_send (mem_ctx=<value optimized out>, ev=0x7f023e82d4f0, handle=<value optimized out>, data=<value optimized out>,   len=92) at rpc_server/srv_pipe_hnd.c:538
#16 0x00007f023c9d7f79 in api_dcerpc_cmd (conn=0x7f023e844b00, vuid=<value optimized out>, req=<value optimized out>,   setup=<value optimized out>, data=<value optimized out>, params=<value optimized out>, suwcnt=2, tdscnt=92, tpscnt=0,   mdrcnt=1024, mprcnt=0) at smbd/ipc.c:271
#17 api_fd_reply (conn=0x7f023e844b00, vuid=<value optimized out>, req=<value optimized out>, setup=<value optimized out>,   data=<value optimized out>, params=<value optimized out>, suwcnt=2, tdscnt=92, tpscnt=0, mdrcnt=1024, mprcnt=0)  at smbd/ipc.c:482
#18 0x00007f023c9d847b in named_pipe (conn=0x7f023e844b00, req=0x7f023e85ceb0, state=0x7f023e846c10) at smbd/ipc.c:537
#19 handle_trans (conn=0x7f023e844b00, req=0x7f023e85ceb0, state=0x7f023e846c10) at smbd/ipc.c:594
#20 0x00007f023c9d92ea in reply_trans (req=0x7f023e85ceb0) at smbd/ipc.c:779
#21 0x00007f023ca41604 in switch_message (type=37 '%', req=0x7f023e85ceb0, size=180) at smbd/process.c:1574
#22 0x00007f023ca41a1b in construct_reply (sconn=0x7f023e82d5b0, inbuf=<value optimized out>, nread=180, unread_bytes=0, seqnum=<value optimized out>, encrypted=false, deferred_pcd=0x0) at smbd/process.c:1610
#23 process_smb (sconn=0x7f023e82d5b0, inbuf=<value optimized out>, nread=180, unread_bytes=0, seqnum=<value optimized out>,   encrypted=false, deferred_pcd=0x0) at smbd/process.c:1688
#24 0x00007f023ca41e35 in smbd_server_connection_read_handler (conn=0x7f023e82d5b0, fd=27) at smbd/process.c:2318
#25 0x00007f023cd01ad7 in run_events_poll (ev=0x7f023e82d4f0, pollrtn=<value optimized out>, pfds=0x7f023e844670, num_pfds=2)  at lib/events.c:286
#26 0x00007f023ca3f97d in smbd_server_connection_loop_once (sconn=0x7f023e82d5b0) at smbd/process.c:1017
#27 smbd_process (sconn=0x7f023e82d5b0) at smbd/process.c:3159
#28 0x00007f023cf628cf in smbd_accept_connection (ev=<value optimized out>, fde=<value optimized out>,   flags=<value optimized out>, private_data=<value optimized out>) at smbd/server.c:514
#29 0x00007f023cd01ad7 in run_events_poll (ev=0x7f023e82d4f0, pollrtn=<value optimized out>, pfds=0x7f023e846e40, num_pfds=5)  at lib/events.c:286
#30 0x00007f023cd01f8f in s3_event_loop_once (ev=0x7f023e82d4f0, location=<value optimized out>) at lib/events.c:349
#31 0x00007f023cd02310 in _tevent_loop_once (ev=0x7f023e82d4f0, location=0x7f023d16d929 "smbd/server.c:820")  at ../lib/tevent/tevent.c:494
#32 0x00007f023cf63bcb in smbd_parent_loop (argc=<value optimized out>, argv=0x7f023e851450) at smbd/server.c:820
#33 main (argc=<value optimized out>, argv=0x7f023e851450) at smbd/server.c:1304