[Samba] Samba 4.4.5 exists with segmention fault on FreeBSD 10.3 during domain provision

[Michael Osipov]

Hi folks,

I am trying to set up a domain/forest in VirtualBox server.
My setup:
* # uname -a
   FreeBSD bsd1dc.ad001.osipov.eu 10.3-RELEASE-p4 FreeBSD 
10.3-RELEASE-p4 64 bit
* Samba 4.4.5 from Ports tree
   # samba-tool -V
   4.4.5
* Python 2 from Ports tree
   # python2 --version
   Python 2.7.12

Installation went smoothly but during domain provisioning Python fails 
with a segmentation fault and leaves a core dump file.

The very last output of samba-tool:
store_acl_blob_fsp: storing blob length 356 on file 
/var/db/samba4/sysvol/ad001.osipov.eu/Policies
delete_windows_lock_ref_count for file 
/var/db/samba4/sysvol/ad001.osipov.eu/Policies
Speicherschutzverletzung(core dumped)

Running the same operation again with truss:
write(2,"store_acl_blob_fsp: storing blob"...,99) = 99 (0x63)
extattr_set_fd(0xf,0x1,0x827447cbf,0x825859760,0x164) = 356 (0x164)
write(2,"delete_windows_lock_ref_count fo"...,86) = 86 (0x56)
close(15)                                        = 0 (0x0)
umask(0x12)                                      = 0 (0x0)
fcntl(10,F_SETLKW,0x7fffffffcba8)                = 0 (0x0)
fcntl(10,F_SETLKW,0x7fffffffcc48)                = 0 (0x0)
fcntl(12,F_SETLK,0x7fffffffbdf8)                 = 0 (0x0)
fcntl(12,F_SETLKW,0x7fffffffbe78)                = 0 (0x0)
fcntl(12,F_SETLKW,0x7fffffffbee8)                = 0 (0x0)
fcntl(11,F_SETLK,0x7fffffffcd28)                 = 0 (0x0)
fcntl(11,F_SETLKW,0x7fffffffcda8)                = 0 (0x0)
fcntl(11,F_SETLKW,0x7fffffffce18)                = 0 (0x0)
SIGNAL 11 (SIGSEGV)
process killed, signal = 11 (core dumped)

Loading the core dump in GDB (command 'where') gives me:
#0  0x0000000806e5ba6e in ndr_pull_uint8 (ndr=0x833ce82e0, ndr_flags=256,
     v=0x7fffffffcc5f "") at ../librpc/ndr/ndr_basic.c:82
#1  0x0000000806e5f133 in ndr_pull_enum_uint8 (ndr=0x833ce82e0, 
ndr_flags=256,
     v=0x7fffffffcc5f "") at ../librpc/ndr/ndr_basic.c:346
#2  0x000000080708bf95 in ndr_pull_security_descriptor_revision (
     ndr=0x833ce82e0, ndr_flags=256, r=0x832200480)
     at default/librpc/gen_ndr/ndr_security.c:657
#3  0x000000080708ccb7 in ndr_pull_security_descriptor (ndr=0x833ce82e0,
     ndr_flags=768, r=0x832200480) at 
default/librpc/gen_ndr/ndr_security.c:768
#4  0x0000000806e692f6 in ndr_pull_struct_blob_all (blob=0x7fffffffce08,
     mem_ctx=0x8021fb100, p=0x832200480,
     fn=0x80708cbb0 <ndr_pull_security_descriptor>) at 
../librpc/ndr/ndr.c:1133
#5  0x0000000811761084 in py_security_descriptor_ndr_unpack (
     py_obj=0x82607bf50, args=0x817a7aa10, kwargs=0x82607d398)
     at default/librpc/gen_ndr/py_security.c:1518
..

Both, truss output and core dump can be provided.

What can I do about this crash? Downgrade Python?

Help is pretty much appreciated.

Michael