Samba 4.7.0 Available for Download

Samba 4.7.0 (gzipped)

                   Release Notes for Samba 4.7.0
                        September 20, 2017

This is the first stable release of Samba 4.7.
Please read the release notes carefully before upgrading.


'smbclient' changes

'smbclient' no longer prints a 'Domain=[...] OS=[Windows 6.1] Server=[...]'
banner when connecting to the first server. With SMB2 and Kerberos,
there's no way to print this information reliably. Now we avoid it at all
consistently. In interactive sessions the following banner is now presented
to the user: 'Try "help" do get a list of possible commands.'.

The default for "client max protocol" has changed to "SMB3_11",
which means that 'smbclient' (and related commands) will work against
servers without SMB1 support.

It's possible to use the '-m/--max-protocol' option to overwrite
the "client max protocol" option temporarily.

Note that the '-e/--encrypt' option also works with most SMB3 servers
(e.g. Windows >= 2012 and Samba >= 4.0.0), so the SMB1 unix extensions
are not required for encryption.

The change to SMB3_11 as default also means 'smbclient' no longer
negotiates SMB1 unix extensions by default, when talking to a Samba server with
"unix extensions = yes".  As a result, some commands are not available, e.g.
'posix_encrypt', 'posix_open', 'posix_mkdir', 'posix_rmdir', 'posix_unlink',
'posix_whoami', 'getfacl' and 'symlink'. Using "-mNT1" reenables them, if the
server supports SMB1.

Note the default ("CORE") for "client min protocol" hasn't changed,
so it's still possible to connect to SMB1-only servers by default.

'smbclient' learned a new command 'deltree' that is able to do
a recursive deletion of a directory tree.


Whole DB read locks: Improved LDAP and replication consistency

Prior to Samba 4.7 and ldb 1.2.0, the LDB database layer used by Samba
erroneously did not take whole-DB read locks to protect search
and DRS replication operations.

While each object returned remained subject to a record-level lock (so
would remain consistent to itself), under a race condition with a
rename or delete, it and any links (like the member attribute) to it
would not be returned.

The symptoms of this issue include:

Replication failures with this error showing in the client side logs:
 error during DRS repl ADD: No objectClass found in replPropertyMetaData for
 Failed to commit objects:

A crash of the server, in particular the rpc_server process with

LDAP read inconsistency
 A DN subject to a search at the same time as it is being renamed
 may not appear under either the old or new name, but will re-appear
 for a subsequent search.

See for more details
and updated advise on database recovery for affected installations.

Samba AD with MIT Kerberos

After four years of development, Samba finally supports compiling and
running Samba AD with MIT Kerberos. You can enable it with:

    ./configure --with-system-mitkrb5

Samba requires version 1.15.1 of MIT Kerberos to build with AD DC support.
The krb5-devel and krb5-server packages are required.
The feature set is not on par with the Heimdal build but the most important
things, like forest and external trusts, are working. Samba uses the KDC binary
provided by MIT Kerberos.

Missing features, compared to Heimdal, are:
  * PKINIT support
  * S4U2SELF/S4U2PROXY support
  * RODC support (not fully working with Heimdal either)

The Samba AD process will take care of starting the MIT KDC and it will load a
KDB (Kerberos Database) driver to access the Samba AD database.  When
provisioning an AD DC using 'samba-tool' it will take care of creating a correct
kdc.conf file for the MIT KDC.

For further details, see:

Dynamic RPC port range

The dynamic port range for RPC services has been changed from the old default
value "1024-1300" to "49152-65535". This port range is not only used by a
Samba AD DC, but also applies to all other server roles including NT4-style
domain controllers. The new value has been defined by Microsoft in Windows
Server 2008 and newer versions. To make it easier for Administrators to control
those port ranges we use the same default and make it configurable with the
option: "rpc server dynamic port range".

The "rpc server port" option sets the first available port from the new
"rpc server dynamic port range" option. The option "rpc server port" only
applies to Samba provisioned as an AD DC.

Authentication and Authorization audit support

Detailed authentication and authorization audit information is now
logged to Samba's debug logs under the "auth_audit" debug class,
including in particular the client IP address triggering the audit
line.  Additionally, if Samba is compiled against the jansson JSON
library, a JSON representation is logged under the "auth_json_audit"
debug class.

Audit support is comprehensive for all authentication and
authorisation of user accounts in the Samba Active Directory Domain
Controller, as well as the implicit authentication in password
changes.  In the file server and classic/NT4 domain controller, NTLM
authentication, SMB and RPC authorization is covered, however password
changes are not at this stage, and this support is not currently
backed by a testsuite.

For further details, see:

Multi-process LDAP Server

The LDAP server in the AD DC now honours the process model used for
the rest of the 'samba' process, rather than being forced into a single
process.  This aids in Samba's ability to scale to larger numbers of AD
clients and the AD DC's overall resiliency, but will mean that there is a
fork()ed child for every LDAP client, which may be more resource
intensive in some situations.  If you run Samba in a
resource-constrained VM, consider allocating more RAM and swap space.

Improved Read-Only Domain Controller (RODC) Support

Support for RODCs in Samba AD until now has been experimental. With this latest
version, many of the critical bugs have been fixed and the RODC can be used in
DC environments requiring no writable behaviour. RODCs now correctly support
bad password lockouts and password disclosure auditing through the
msDS-RevealedUsers attribute.

The fixes made to the RWDC will also allow Windows RODC to function more
correctly and to avoid strange data omissions such as failures to replicate
groups or updated passwords. Password changes are currently rejected at the
RODC, although referrals should be given over LDAP. While any bad passwords can
trigger domain-wide lockout, good passwords which have not been replicated yet
for a password change can only be used via NTLM on the RODC (and not Kerberos).

The reliability of RODCs locating a writable partner still requires some
improvements and so the 'password server' configuration option is generally
recommended on the RODC.

Samba 4.7 is the first Samba release to be secure as an RODC or when
hosting an RODC.  If you have been using earlier Samba versions to
host or be an RODC, please upgrade.

In particular see for
details on the security implications for password disclosure to an
RODC using earlier versions.

Additional password hashes stored in supplementalCredentials

A new config option 'password hash userPassword schemes' has been added to
enable generation of SHA-256 and SHA-512 hashes (without storing the plaintext
password with reversible encryption). This builds upon previous work to improve
password sync for the AD DC (originally using GPG).

The user command of 'samba-tool' has been updated in order to be able to
extract these additional hashes, as well as extracting the (HTTP) WDigest
hashes that we had also been storing in supplementalCredentials.

Improvements to DNS during Active Directory domain join

The 'samba-tool' domain join command will now add the A and GUID DNS records
(on both the local and remote servers) during a join if possible via RPC. This
should allow replication to proceed more smoothly post-join.

The mname element of the SOA record will now also be dynamically generated to
point to the local read-write server. 'samba_dnsupdate' should now be more
reliable as it will now find the appropriate name server even when resolv.conf
points to a forwarder.

Significant AD performance and replication improvements

Previously, replication of group memberships was been an incredibly expensive
process for the AD DC. This was mostly due to unnecessary CPU time being spent
parsing member linked attributes. The database now stores these linked
attributes in sorted form to perform efficient searches for existing members.
In domains with a large number of group memberships, a join can now be
completed in half the time compared with Samba 4.6.

LDAP search performance has also improved, particularly in the unindexed search
case. Parsing and processing of security descriptors should now be more
efficient, improving replication but also overall performance.

Query record for open file or directory

The record attached to an open file or directory in Samba can be
queried through the 'net tdb locking' command. In clustered Samba this
can be useful to determine the file or directory triggering
corresponding "hot" record warnings in ctdb.

Removal of lpcfg_register_defaults_hook()

The undocumented and unsupported function lpcfg_register_defaults_hook()
that was used by external projects to call into Samba and modify
smb.conf default parameter settings has been removed. If your project
was using this call please raise the issue on in order to design a supported
way of obtaining the same functionality.

Change of loadable module interface

The _init function of all loadable modules in Samba has changed

NTSTATUS _init(void);



This allows a program loading a module to pass in a long-lived
talloc context (which must be guaranteed to be alive for the
lifetime of the module). This allows modules to avoid use of
the talloc_autofree_context() (which is inherently thread-unsafe)
and still be valgrind-clean on exit. Modules that don't need to
free long-lived data on exit should use the NULL talloc context.

SHA256 LDAPS Certificates

The self-signed certificate generated for use on LDAPS will now be
generated with a SHA256 self-signature, not a SHA1 self-signature.

Replacing this certificate with a certificate signed by a trusted
CA is still highly recommended.

CTDB changes

* CTDB no longer allows mixed minor versions in a cluster

  See the AllowMixedVersions tunable option in ctdb-tunables(7) and also

* CTDB now ignores hints from Samba about TDB flags when attaching to databases

  CTDB will use the correct flags depending on the type of database.
  For clustered databases, the smb.conf setting
  dbwrap_tdb_mutexes:*=true will be ignored. Instead, CTDB continues
  to use the TDBMutexEnabled tunable.

* New configuration variable CTDB_NFS_CHECKS_DIR

  See ctdbd.conf(5) for more details.

* The CTDB_SERVICE_AUTOSTARTSTOP configuration variable has been

  To continue to manage/unmanage services while CTDB is running:

  - Start service by hand and then flag it as managed

  - Mark service as unmanaged and shut it down by hand

  - In some cases CTDB does something fancy - e.g. start Samba under
    "nice", so care is needed. One technique is to disable the
    eventscript, mark as managed, run the startup event by hand and then
    re-enable the eventscript.

* The CTDB_SCRIPT_DEBUGLEVEL configuration variable has been removed

* The example NFS Ganesha call-out has been improved

* A new "replicated" database type is available

  Replicated databases are intended for CTDB's internal use to
  replicate state data across the cluster, but may find other
  uses. The data in replicated databases is valid for the lifetime of
  CTDB and cleared on first attach.

Using x86_64 Accelerated AES Crypto Instructions

Samba on x86_64 can now be configured to use the Intel accelerated AES
instruction set, which has the potential to make SMB3 signing and
encryption much faster on client and server. To enable this, configure
Samba using the new option --accel-aes=intelaesni.

This is a temporary solution that is being included to allow users
to enjoy the benefits of Intel accelerated AES on the x86_64 platform,
but the longer-term solution will be to move Samba to a fully supported
external crypto library.

The third_party/aesni-intel code will be removed from Samba as soon as
external crypto library performance reaches parity.

The default is to build without setting --accel-aes, which uses the
existing Samba software AES implementation.

Parameter changes

The "strict sync" global parameter has been changed from
a default of "no" to "yes". This means smbd will by default
obey client requests to synchronize unwritten data in operating
system buffers safely onto disk. This is a safer default setting
for modern SMB1/2/3 clients.

The 'ntlm auth' option default is renamed to 'ntlmv2-only', reflecting
the previous behaviour.  Two new values have been provided,
'mschapv2-and-ntlmv2-only' (allowing MSCHAPv2 while denying NTLMv1)
and 'disabled', totally disabling NTLM authentication and password

smb.conf changes

  Parameter Name                     Description             Default
  --------------                     -----------             -------
  allow unsafe cluster upgrade       New parameter           no
  auth event notification            New parameter           no
  auth methods                       Deprecated
  client max protocol                Effective               SMB3_11
                                     default changed
  map untrusted to domain            New value/              auto
                                     Default changed/
  mit kdc command                    New parameter
  profile acls                       Deprecated
  rpc server dynamic port range      New parameter           49152-65535
  strict sync                        Default changed         yes
  password hash userPassword schemes New parameter
  ntlm auth                          New values              ntlmv2-only



o  CVE-2017-12150:
   A man in the middle attack may hijack client connections.

o  CVE-2017-12151:
   A man in the middle attack can read and may alter confidential
   documents transferred via a client connection, which are reached
   via DFS redirect when the original connection used SMB3.

o  CVE-2017-12163:
   Client with write access to a share can cause server memory contents to be
   written into a file or printer.


o  Jeremy Allison <>
   * BUG 13003: s3: vfs: catia: compression get/set must act only on base file, and
     must cope with fsp==NULL.
   * BUG 13008: lib: crypto: Make smbd use the Intel AES instruction set for signing
     and encryption.

o  Andrew Bartlett <>
   * BUG 12946: s4-drsuapi: Avoid segfault when replicating as a non-admin with
   * BUG 13015: Allow re-index of newer databases with binary GUID TDB keys
     (this officially removes support for re-index of the original pack format 0,
     rather than simply segfaulting).
   * BUG 13017: Add ldb_ldif_message_redacted_string() to allow debug of redacted
     log messages, avoiding showing secret values.
   * BUG 13023: ldb: version 1.2.2.
   * BUG 13025: schema: Rework dsdb_schema_set_indices_and_attributes() db

o  Alexander Bokovoy <>
   * BUG 13030: Install dcerpc/ for all Python environments.

o  Ralph Boehme <>
   * BUG 13024: s3/smbd: Sticky write time offset miscalculation causes broken
   * BUG 13037: lib/util: Only close the event_fd in tfork if the caller didn't
     call tfork_event_fd().

o  Volker Lendecke <>
   * BUG 13006: messaging: Avoid a socket leak after fork.

o  Stefan Metzmacher <>
   * BUG 13018: charset: Fix str[n]casecmp_m() by comparing lower case values.

o  Gary Lockyer <>
   * BUG 13037: util_runcmd: Free the fde in event handler.

o  Amitay Isaacs <>
   * BUG 13012: ctdb-daemon: Fix implementation of process_exists control.
   * BUG 13021: GET_DB_SEQNUM control can cause ctdb to deadlock when databases
     are frozen.
   * BUG 13029: ctdb-daemon: Free up record data if a call request is deferred.
   * BUG 13036: ctdb-client: Initialize ctdb_ltdb_header completely for empty

o  Christof Schmitt <>
   * BUG 13032: vfs_streams_xattr: Fix segfault when running with log level 10.


o  Andrew Bartlett <>
   * BUG 12929: smb.conf: Explain that "ntlm auth" is a per-passdb setting.
   * BUG 12953: s4/lib/tls: Use SHA256 to sign the TLS certificates.

o  Jeremy Allison <>
   * BUG 12932: Get rid of talloc_autofree_context().

o  Amitay Isaacs <>
   * BUG 12978: After restarting CTDB, it attaches replicated databases with
     wrong flags.

o  Stefan Metzmacher <>
   * BUG 12863: s3:smbclient: Don't try any workgroup listing with
     "client min protocol = SMB2".
   * BUG 12876: s3:libsmb: Don't call cli_NetServerEnum() on SMB2/3 connections
     in SMBC_opendir_ctx().
   * BUG 12881: s3:libsmb: Let do_connect() debug the negotiation result
     similar to "session request ok".
   * BUG 12919: s4:http/gensec: add missing tevent_req_done() to
   * BUG 12968: Fix 'smbclient tarmode' with SMB2/3.
   * BUG 12973: 'smbd': Don't use a lot of CPU on startup of a connection.

o  Christof Schmitt <>
   * BUG 12983: vfs_default: Fix passing of errno from async calls.

o  Andreas Schneider <>
   * BUG 12629: s3:utils: Do not report an invalid range for AD DC role.
   * BUG 12704: s3:libsmb: Let get_ipc_connect() use
   * BUG 12930: Fix build issues with GCC 7.1.
   * BUG 12950: s3:script: Untaint user supplied data in
   * BUG 12956: s3:libads: Fix changing passwords with Kerberos.
   * BUG 12975: Fix changing the password with 'smbpasswd' as a local user on
     a domain member.


o  Jeremy Allison <>
   * BUG 12913: Implement cli_smb2_setatr() by calling cli_smb2_setpathinfo().

o  Andrew Bartlett <>
   * BUG 11392: s4-cldap/netlogon: Match Windows 2012R2 and return
     NETLOGON_NT_VERSION_5 when version unspecified.
   * BUG 12855: dsdb: Do not force a re-index of sam.ldb on upgrade to 4.7.
   * BUG 12904: dsdb: Fix dsdb_next_callback to correctly use ldb_module_done()
   * BUG 12939: s4-rpc_server: Improve debug of new endpoints.

o  Ralph Boehme <>
   * BUG 12791: Fix kernel oplocks issues with named streams.
   * BUG 12944: vfs_gpfs: Handle EACCES when fetching DOS attributes from xattr.

o  Bob Campbell <>
   * BUG 12842: samdb/cracknames: Support user and service principal as desired

o  David Disseldorp <>
   * BUG 12911: vfs_ceph: Fix cephwrap_chdir().

o  Gary Lockyer <>
   * BUG 12865: Track machine account ServerAuthenticate3.

o  Marc Muehlfeld <>
   * BUG 12947: python: Fix incorrect kdc.conf parameter name in

o  Noel Power <>
   * BUG 12937: s3/utils: 'smbcacls' failed to detect DIRECTORIES using SMB2
     (Windows only).

o  Arvid Requate <>
   * BUG 11392: s4-dsdb/netlogon: Allow missing ntver in cldap ping.

o  Anoop C S <>
   * BUG 12936: source3/client: Fix typo in help message displayed by default.

o  Andreas Schneider <>
   * BUG 12930: Fix building with GCC 7.1.1.


o  Jeremy Allison <>
   * BUG 12836: s3: smbd: Fix a read after free if a chained SMB1 call goes
   * BUG 12899: s3: libsmb: Reverse sense of 'clear all attributes', ignore
     attribute change in SMB2 to match SMB1.
   * BUG 12914: s3: smbclient: Add new command deltree.

o  Ralph Boehme <>
   * BUG 12885: s3/smbd: Let non_widelink_open() chdir() to directories
   * BUG 12887: Remove SMB_VFS_STRICT_UNLOCK noop from the VFS.
   * BUG 12891: Enable TDB mutexes in dbwrap and ctdb.
   * BUG 12897: vfs_fruit: don't use MS NFS ACEs with Windows clients.
   * BUG 12910: s3/notifyd: Ensure notifyd doesn't return from

o  Alexander Bokovoy <>
   * BUG 12905: Build py3 versions of other rpc modules.

o  Günther Deschner <>
   * BUG 12840: vfs_fruit: Add "fruit:model = <modelname>" parametric option.

o  Dustin L. Howett
   * BUG 12720: idmap_ad: Retry query_user exactly once if we get

o  Amitay Isaacs <>
   * BUG 12891: dbwrap_ctdb: Fix calculation of persistent flag.

o  Thomas Jarosch <>
   * BUG 12927: s3: libsmb: Fix use-after-free when accessing pointer *p.

o  Volker Lendecke <>
   * BUG 12925: smbd: Fix a connection run-down race condition.

o  Stefan Metzmacher <>
   * tevent: version 0.9.33: make tevent_req_print() more robust against crashes.
   * ldb: version 1.2.1
   * BUG 12882: Do not install if we have system libldb.
   * BUG 12890: s3:smbd: consistently use talloc_tos() memory for
   * BUG 12900: Fix index out of bound in ldb_msg_find_common_values.

o  Rowland Penny <>
   * BUG 12884: Easily edit a users object in AD, as if using 'ldbedit'.

o  Bernhard M. Wiedemann <>
   * BUG 12906: s3: drop build_env

o  Andreas Schneider <>
   * BUG 12882: waf: Do not install if we have system libldb.

o  Martin Schwenke <>
   * BUG 12898: ctdb-common: Set close-on-exec when creating PID file.


o  Jeffrey Altman <>
   * BUG 12894: CVE-2017-11103: Orpheus' Lyre KDC-REP service name validation