[Pkg-samba-maint] segfault when using Samba template

[Sam Nazarko]

Hello

We're still experiencing a problem where using automount templates in smb.conf. There seems to be a segfault in
load_usershare_service(), although the reason for this is not obvious.

Program received signal SIGSEGV, Segmentation fault.
0xf70802a4 in load_usershare_service (servicename=0xaadf7be0 "verbatim") at ../source3/param/loadparm.c:3399
3399    ../source3/param/loadparm.c: No such file or directory.
(gdb) thread apply all bt full

Thread 1 (Thread 0xf5cc2000 (LWP 2444)):
#0  0xf70802a4 in load_usershare_service (servicename=0xaadf7be0 "verbatim") at ../source3/param/loadparm.c:3399
        sbuf = {st_ex_dev = 64768, st_ex_ino = 2353, st_ex_mode = 17400, st_ex_nlink = 2, st_ex_uid = 0, st_ex_gid = 112, st_ex_rdev = 0, st_ex_size = 0, st_ex_atime = {tv_sec = 1490705557, tv_nsec = 670066722}, st_ex_mtime = {
            tv_sec = 1490705482, tv_nsec = 10000004}, st_ex_ctime = {tv_sec = 1490705482, tv_nsec = 10000004}, st_ex_btime = {tv_sec = 1490705482, tv_nsec = 10000004}, st_ex_calculated_birthtime = true, st_ex_blksize = 4096,
          st_ex_blocks = 8, st_ex_flags = 0, st_ex_mask = 4294897140}
        usersharepath = 0xaadc9a88 "/var/lib/samba/usershares"
        max_user_shares = <optimized out>
        snum_template = 3
        __FUNCTION__ = "load_usershare_service"

The full backtrace can be found here [1].

This issue can be replicated with the following smb.conf:

[global]​
    config file = /etc/samba/smb-local.conf
    workgroup = WORKGROUP
    security=user
    follow symlinks = yes
    wide links = no
    unix extensions = no
    lock directory = /var/cache/samba
    load printers = no
    printing = bsd
    printcap name = /dev/null
    disable spoolss = yes
    log level = 1
    map to guest = bad user
    usershare template share = automount template
    read raw = Yes
    write raw = Yes
    strict locking = no
    min receivefile size = 16384
    use sendfile = true
    aio read size = 2048
    aio write size = 2048
    socket options = TCP_NODELAY IPTOS_LOWDELAY SO_RCVBUF=131072 SO_SNDBUF=131072

[osmc]
    browsable = yes
    read only = no
    valid users = osmc
    path = /home/osmc
    comment = OSMC Home Directory

[automount template]
    browseable = yes
    -valid = no
    valid users = osmc
    path = %P
    hide files = /$RECYCLE.BIN/System Volume Information/desktop.ini/thumbs.db/

Please let us know what further information you need to get this addressed. I would appreciate being copied in on any replies
as I am not subscribed to this list.

Thank you,
  
Sam Nazarko
  
[1] http://paste.osmc.io/uyidofulus.xml