Panic or segfault in Samba

[Steve Westwood]

Crash happens irregularly, sometimes on boot, sometimes not. Error is
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007f9d8453db4c in __libc_waitpid (pid=1641, stat_loc=stat_loc@entry=0x7fff4cf624a0, options=options@entry=0) at ../sysdeps/unix/sysv/linux/waitpid.c:31
#0 0x00007f9d8453db4c in __libc_waitpid (pid=1641, stat_loc=stat_loc@entry=0x7fff4cf624a0, options=options@entry=0) at ../sysdeps/unix/sysv/linux/waitpid.c:31
#1 0x00007f9d844c32e2 in do_system (line=line@entry=0x7f9d88890bc0 "/usr/share/samba/panic-action 857") at ../sysdeps/posix/system.c:148
#2 0x00007f9d844c364a in __libc_system (line=line@entry=0x7f9d88890bc0 "/usr/share/samba/panic-action 857") at ../sysdeps/posix/system.c:184
#3 0x00007f9d875a7235 in system (line=line@entry=0x7f9d88890bc0 "/usr/share/samba/panic-action 857") at pt-system.c:28
#4 0x00007f9d85e57061 in smb_panic_s3 (why=<optimized out>) at ../source3/lib/util.c:798
#5 0x00007f9d8737fc6f in smb_panic (why=why@entry=0x7f9d879e67e3 "open_sockets_smbd() failed") at ../lib/util/fault.c:159
#6 0x00007f9d86f9d922 in exit_server_common (how=how@entry=SERVER_EXIT_ABNORMAL, reason=0x7f9d879e67e3 "open_sockets_smbd() failed") at ../source3/smbd/server_exit.c:206
#7 0x00007f9d86f9dbe1 in smbd_exit_server (explanation=<optimized out>) at ../source3/smbd/server_exit.c:224
#8 0x00007f9d857b0b02 in exit_server (reason=<optimized out>) at ../source3/lib/smbd_shim.c:105
#9 0x00007f9d879e05bf in main (argc=<optimized out>, argv=<optimized out>) at ../source3/smbd/server.c:1544
A debugging session is active.