(gdb) bt
#0  0x00007fd669dcda57 in __GI___wait4 (pid=4892, stat_loc=stat_loc@entry=0x7ffe1a00c9c8, options=options@entry=0, usage=usage@entry=0x0) at ../sysdeps/unix/sysv/linux/wait4.c:30
#1  0x00007fd669dcd9d7 in __GI___waitpid (pid=<optimized out>, stat_loc=stat_loc@entry=0x7ffe1a00c9c8, options=options@entry=0) at ./posix/waitpid.c:38
#2  0x00007fd669d4620b in do_system (line=line@entry=0x5556251bbea0 "/bin/sleep 999999") at ../sysdeps/posix/system.c:171
#3  0x00007fd669d463aa in __libc_system (line=line@entry=0x5556251bbea0 "/bin/sleep 999999") at ../sysdeps/posix/system.c:207
#4  0x00007fd66a26b937 in smb_panic_s3 (why=<optimized out>) at ../../source3/lib/util.c:692
#5  0x00007fd669f5486a in smb_panic (why=why@entry=0x7ffe1a00cd90 "Signal 11: Segmentation fault") at ../../lib/util/fault.c:209
#6  0x00007fd669f548f1 in fault_report (sig=11) at ../../lib/util/fault.c:83
#7  sig_fault (sig=11) at ../../lib/util/fault.c:94
#8  <signal handler called>
#9  0x00007fd66a325147 in vfs_offload_token_db_fetch_fsp (ctx=0x0, token_blob=token_blob@entry=0x5556251a3880, fsp=fsp@entry=0x7ffe1a00d318) at ../../source3/modules/offload_token.c:203
#10 0x00007fd665951332 in btrfs_offload_write_send (handle=0x55562519f790, mem_ctx=<optimized out>, ev=0x555625174ad0, fsctl=1327346, token=0x5556251a3880, transfer_offset=0,
    dest_fsp=0x5556251aec80, dest_off=0, num=1048576) at ../../source3/modules/vfs_btrfs.c:266
#11 0x00007fd66a39e140 in fsctl_srv_copychunk_loop (req=req@entry=0x5556251a3650) at ../../source3/smbd/smb2_ioctl_network_fs.c:199
#12 0x00007fd66a39f0f3 in fsctl_srv_copychunk_send (smb2req=<optimized out>, in_max_output=12, in_input=0x5556251b64c8, dst_fsp=0x5556251aec80, ctl_code=622283472, ev=0x555625174ad0,
    mem_ctx=0x5556251b64b0) at ../../source3/smbd/smb2_ioctl_network_fs.c:165
#13 smb2_ioctl_network_fs (ctl_code=ctl_code@entry=1327346, ev=ev@entry=0x555625174ad0, req=req@entry=0x5556251b62d0, state=0x5556251b64b0)
    at ../../source3/smbd/smb2_ioctl_network_fs.c:632
#14 0x00007fd66a39bee5 in smbd_smb2_ioctl_send (in_flags=1, in_max_output=<optimized out>, in_input=..., in_ctl_code=<optimized out>, fsp=0x5556251aec80, smb2req=0x5556251b5d30,
    ev=0x555625174ad0, mem_ctx=0x5556251b5d30) at ../../source3/smbd/smb2_ioctl.c:465
#15 smbd_smb2_request_process_ioctl (req=req@entry=0x5556251b5d30) at ../../source3/smbd/smb2_ioctl.c:224
#16 0x00007fd66a38aa54 in smbd_smb2_request_dispatch (req=req@entry=0x5556251b5d30) at ../../source3/smbd/smb2_server.c:3510
#17 0x00007fd66a38bbb1 in smbd_smb2_io_handler (fde_flags=<optimized out>, xconn=0x55562518b8a0) at ../../source3/smbd/smb2_server.c:5101
#18 smbd_smb2_connection_handler (ev=<optimized out>, fde=<optimized out>, flags=<optimized out>, private_data=<optimized out>) at ../../source3/smbd/smb2_server.c:5139
#19 0x00007fd669ee39e1 in tevent_common_invoke_fd_handler (fde=fde@entry=0x55562518a680, flags=1, removed=removed@entry=0x0) at ../../tevent_fd.c:158
#20 0x00007fd669ee9f97 in epoll_event_loop (tvalp=0x7ffe1a00d730, epoll_ev=0x55562517bf90) at ../../tevent_epoll.c:730
#21 epoll_event_loop_once (ev=<optimized out>, location=<optimized out>) at ../../tevent_epoll.c:946
#22 0x00007fd669ee82b7 in std_event_loop_once (ev=0x555625174ad0, location=0x7fd66a44acc8 "../../source3/smbd/smb2_process.c:2017") at ../../tevent_standard.c:110
#23 0x00007fd669ee2c11 in _tevent_loop_once (ev=ev@entry=0x555625174ad0, location=location@entry=0x7fd66a44acc8 "../../source3/smbd/smb2_process.c:2017") at ../../tevent.c:823
#24 0x00007fd669ee2f0b in tevent_common_loop_wait (ev=0x555625174ad0, location=0x7fd66a44acc8 "../../source3/smbd/smb2_process.c:2017") at ../../tevent.c:952
#25 0x00007fd669ee8257 in std_event_loop_wait (ev=0x555625174ad0, location=0x7fd66a44acc8 "../../source3/smbd/smb2_process.c:2017") at ../../tevent_standard.c:141
#26 0x00007fd66a378c6c in smbd_process (ev_ctx=ev_ctx@entry=0x555625174ad0, msg_ctx=msg_ctx@entry=0x55562515f8f0, sock_fd=sock_fd@entry=35, interactive=interactive@entry=false)
    at ../../source3/smbd/smb2_process.c:2017
#27 0x00005556238ece8e in smbd_accept_connection (ev=0x555625174ad0, fde=<optimized out>, flags=<optimized out>, private_data=<optimized out>) at ../../source3/smbd/server.c:1031
#28 0x00007fd669ee39e1 in tevent_common_invoke_fd_handler (fde=fde@entry=0x55562518a3e0, flags=1, removed=removed@entry=0x0) at ../../tevent_fd.c:158
#29 0x00007fd669ee9f97 in epoll_event_loop (tvalp=0x7ffe1a00da00, epoll_ev=0x555625174d00) at ../../tevent_epoll.c:730
#30 epoll_event_loop_once (ev=<optimized out>, location=<optimized out>) at ../../tevent_epoll.c:946
#31 0x00007fd669ee82b7 in std_event_loop_once (ev=0x555625174ad0, location=0x5556238efd48 "../../source3/smbd/server.c:1373") at ../../tevent_standard.c:110
#32 0x00007fd669ee2c11 in _tevent_loop_once (ev=ev@entry=0x555625174ad0, location=location@entry=0x5556238efd48 "../../source3/smbd/server.c:1373") at ../../tevent.c:823
#33 0x00007fd669ee2f0b in tevent_common_loop_wait (ev=0x555625174ad0, location=0x5556238efd48 "../../source3/smbd/server.c:1373") at ../../tevent.c:952
#34 0x00007fd669ee8257 in std_event_loop_wait (ev=0x555625174ad0, location=0x5556238efd48 "../../source3/smbd/server.c:1373") at ../../tevent_standard.c:141
#35 0x00005556238ea29b in smbd_parent_loop (parent=0x5556251726a0, ev_ctx=0x555625174ad0) at ../../source3/smbd/server.c:1373
#36 main (argc=<optimized out>, argv=<optimized out>) at ../../source3/smbd/server.c:2130