Samba 4.12 Features added/changed

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Samba 4.12 is ''Security Fixes_Only Mode.

Samba 4.12.15

Release Notes for Samba 4.12.15
April 29, 2021

This is a security release in order to address the following defect:

  • CVE-2021-20254: Negative idmap cache entries can cause incorrect group entries in the Samba file server process token.


The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user.
Most commonly this flaw caused the calling code to crash, but an alert user (Peter Eriksson, IT Department, Linköping University) found this flaw by noticing an unprivileged user was able to delete a file within a network share that they should have been disallowed access to.
Analysis of the code paths has not allowed us to discover a way for a remote user to be able to trigger this flaw reproducibly or on demand, but this CVE has been issued out of an abundance of caution.

Changes since 4.12.14

  • Volker Lendecke <>
  • BUG #14571: CVE-2021-20254: Fix buffer overrun in sids_to_unixids().
  Release Notes Samba 4.12.15.

Samba 4.12.14

Release Notes for Samba 4.12.14
March 24, 2021

This is a security release in order to address the following defects:


An anonymous attacker can crash the Samba AD DC LDAP server by sending easily crafted DNs as part of a bind request. More serious heap corruption is likely also possible.
User-controlled LDAP filter strings against the AD DC LDAP server may crash the LDAP server.

For more details, please refer to the security advisories.

Changes since 4.12.12

  • Release with dependency on ldb version 2.1.5.
  • Andrew Bartlett <>
  • Douglas Bagnall <>
  Release Notes Samba 4.12.14.

Samba 4.12.12

Release Notes for Samba 4.12.12
March 11, 2021

This is the latest stable release of the Samba 4.12 release series.

Please note that this will be the last bugfix release of the Samba 4.12 release series. There will be Security Releases only beyond this point.

New GPG key

The GPG release key for Samba releases changed from:

pub   dsa1024/6F33915B6568B7EA 2007-02-04 [SC] [expires: 2021-02-05]
      Key fingerprint = 52FB C0B8 6D95 4B08 4332  4CDC 6F33 915B 6568 B7EA
uid                 [  full  ] Samba Distribution Verification Key <>
sub   elg2048/9C6ED163DA6DFB44 2007-02-04 [E] [expires: 2021-02-05]

to the following new key:

pub   rsa4096/AA99442FB680B620 2020-12-21 [SC] [expires: 2022-12-21]
      Key fingerprint = 81F5 E283 2BD2 545A 1897  B713 AA99 442F B680 B620
uid                 [ultimate] Samba Distribution Verification Key <>
sub   rsa4096/97EF9386FBFD4002 2020-12-21 [E] [expires: 2022-12-21]

Starting from Jan 21th 2021, all Samba releases will be signed with the new key.

See also GPG_AA99442FB680B620_replaces_6F33915B6568B7EA.txt

Changes since 4.12.11

  • Trever L. Adams <>
  • BUG #14634: s3:modules:vfs_virusfilter: Recent talloc changes cause infinite start-up failure.
  • Jeremy Allison <>
  • BUG #13992: SAMBA RPC share error.
  • BUG #14612: s3: smbd: Add call to conn_setup_case_options() to create_conn_struct_as_root().
  • Ralph Boehme <>
  • BUG #14602: s3/auth: Implement "winbind:ignore domains".
  • BUG #14612: build: Remove smbd_conn private library.
  • Peter Eriksson <>
  • BUG #14648: s3: VFS: nfs4_acls. Add missing TALLOC_FREE(frame) in error path.
  • Björn Jacke <>
  • BUG #14624: classicupgrade: Treat old never expires value right.
  • Volker Lendecke <>
  • BUG #14636: g_lock: Fix uninitalized variable reads.
  • Stefan Metzmacher <>
  • BUG #13898: s3:pysmbd: Fix fd leak in py_smbd_create_file().
  • BUG #14607: Work around special SMB2 IOCTL response behavior of NetApp Ontap 7.3.7.
  • Andreas Schneider <>
  • BUG #14625: Fix smbd share mode double free crash.
  • Paul Wise <>
  • BUG #12505: HEIMDAL: krb5_storage_free(NULL) should work.
 Release Notes Samba 4.12.12.

Samba 4.12.11

Release Notes for Samba 4.12.11
January 14, 2021

This is the latest stable release of the Samba 4.12 release series.

Changes since 4.12.10

  • Jeremy Allison <>
  • BUG #14210: libcli: smb2: Never print length if smb2_signing_key_valid() fails for crypto blob.
  • BUG #14486: s3: modules: gluster. Fix the error I made in preventing talloc leaks from a function.
  • BUG #14515: s3: smbd: Don't overwrite contents of fsp->aio_requests[0] with NULL via TALLOC_FREE().
  • BUG #14568: s3: spoolss: Make parameters in call to user_ok_token() match all other uses.
  • BUG #14590: s3: smbd: Quiet log messages from usershares for an unknown share.
  • Dimitry Andric <>
  • BUG #14605: lib: Avoid declaring zero-length VLAs in various messaging functions.
  • Andrew Bartlett <>
  • BUG #14579: Do not create an empty DB when accessing a sam.ldb.
  • Ralph Boehme <>
  • BUG #14248: samba process does not honor "max log size".
  • BUG #14587: vfs_zfsacl: add missing inherited flag on hidden "magic" everyone@ ACE.
  • BUG #14596: vfs_fruit may close wrong backend fd.
  • Günther Deschner <>
  • BUG #14486: s3-vfs_glusterfs: always disable write-behind translator.
  • Arne Kreddig <>
  • BUG #14606: vfs_virusfilter: Allocate separate memory for config char*.
  • Stefan Metzmacher <>
  • Anoop C S <>
  • BUG #14486: manpages/vfs_glusterfs: Mention silent skipping of write-behind translator.
  • BUG #14573: vfs_shadow_copy2: Preserve all open flags assuming ROFS.
  • Andreas Schneider <>
  • BUG #14601: s3:lib: Create the cache path of user gencache recursively.
  • Martin Schwenke <>
  • BUG #14594: Be more flexible with repository names in CentOS 8 test environments.
  • Jones Syue <>
  • BUG #14514: interface: Fix if_index is not parsed correctly.
Release Notes Samba 4.12.11.

Samba 4.12.10

Release Notes for Samba 4.12.10
November 05, 2020

This is the latest stable release of the Samba 4.12 release series.

Major enhancements include:

  • BUG #14537: ctdb-common: Avoid aliasing errors during code optimization.
  • BUG #14486: vfs_glusterfs: Avoid data corruption with the write-behind translator.


The GlusterFS write-behind performance translator, when used with Samba, could be a source of data corruption. The translator, while processing a write call, immediately returns success but continues writing the data to the server in the background. This can cause data corruption when two clients relying on Samba to provide data consistency are operating on the same file.

The write-behind translator is enabled by default on GlusterFS. The vfs_glusterfs plugin will check for the presence of the translator and refuse to connect if detected. Please disable the write-behind translator for the GlusterFS volume to allow the plugin to connect to the volume.

Changes since 4.12.9

  • Jeremy Allison <>
  • BUG #14486: s3: modules: vfs_glusterfs: Fix leak of char **lines onto mem_ctx on return.
  • Ralph Boehme <>
  • BUG #14471: RN: vfs_zfsacl: Only grant DELETE_CHILD if ACL tag is special.
  • Alexander Bokovoy <>
  • BUG #14538: smb.conf.5: Add clarification how configuration changes reflected by Samba.
  • Günther Deschner <>
  • BUG #14486: s3-vfs_glusterfs: Refuse connection when write-behind xlator is present.
  • winexe:: Add configure option to control whether to build it (default: auto).
  • Amitay Isaacs <>
  • BUG #14487: Latest version of Bind9 is now 9.20.
  • BUG #14537: ctdb-common: Avoid aliasing errors during code optimization.
  • Björn Jacke <>
  • BUG #14522: docs: Fix default value of spoolss:architecture.
  • Stefan Metzmacher <>
  • BUG #14531: s4:dsdb:acl_read: Implement "List Object" mode feature.
  • Sachin Prabhu <>
  • BUG #14486: docs-xml/manpages: Add warning about write-behind translator for vfs_glusterfs.
  • Khem Raj <>
  • nsswitch/nsstest.c: Avoid nss function conflicts with glibc nss.h.
  • Martin Schwenke <>
  • BUG #14513: ctdb disable/enable can still fail due to race condition.
  • Andrew Walker <>
  • BUG #14471: RN: vfs_zfsacl: Only grant DELETE_CHILD if ACL tag is special.
Release Notes Samba 4.12.10.

Samba 4.12.9

Release Notes for Samba 4.12.9
October 29, 2020

This is a security release in order to address the following defects:

  • CVE-2020-14318: Missing handle permissions check in SMB1/2/3 ChangeNotify.
  • CVE-2020-14323: Unprivileged user can crash winbind.
  • CVE-2020-14383: An authenticated user can crash the DCE/RPC DNS with easily crafted records.


The SMB1/2/3 protocols have a concept of "ChangeNotify", where a client can request file name notification on a directory handle when a condition such as "new file creation" or "file size change" or "file timestamp update" occurs.
A missing permissions check on a directory handle requesting ChangeNotify meant that a client with a directory handle open only for FILE_READ_ATTRIBUTES (minimal access rights) could be used to obtain change notify replies from the server. These replies contain information that should not be available to directory handles open for FILE_READ_ATTRIBUTE only.
winbind in version 3.6 and later implements a request to translate multiple Windows SIDs into names in one request. This was done for performance reasons: The Microsoft RPC call domain controllers offer to do this translation, so it was an obvious extension to also offer this batch operation on the winbind unix domain stream socket that is available to local processes on the Samba server.
Due to improper input validation a hand-crafted packet can make winbind perform a NULL pointer dereference and thus crash.
Some DNS records (such as MX and NS records) usually contain data in the additional section. Samba's dnsserver RPC pipe (which is an administrative interface not used in the DNS server itself) made an error in handling the case where there are no records present: instead of noticing the lack of records, it dereferenced uninitialised memory, causing the RPC server to crash. This RPC server, which also serves protocols other than dnsserver, will be restarted after a short delay, but it is easy for an authenticated non-admin attacker to crash it again as soon as it returns. The Samba DNS server itself will continue to operate, but many RPC services will not.

For more details, please refer to the security advisories.

Changes since 4.12.8

o Jeremy Allison <>

  • BUG #14434: CVE-2020-14318: s3: smbd: Ensure change notifies can't get set unless the directory handle is open for SEC_DIR_LIST.
  • Douglas Bagnall <>
  • Volker Lendecke <>
Release Notes Samba 4.12.9.

Samba 4.12.8

Release Notes for Samba 4.12.8
October 07, 2020

This is the latest stable release of the Samba 4.12 release series.

Changes since 4.12.7

  • Günther Deschner <>
  • Volker Lendecke <>
  • BUG #14465: idmap_ad does not deal properly with a RFC4511 section 4.4.1 response.
  • Laurent Menase <>
  • Stefan Metzmacher <>
  • BUG #14465: idmap_ad does not deal properly with a RFC4511 section 4.4.1 response.
  • BUG #14482: Compilation of heimdal tree fails if libbsd is not installed.
  • Christof Schmitt <>
  • BUG #14166: util: Allow symlinks in directory_create_or_exist.
  • Andreas Schneider <>
  • BUG #14399: waf: Only use gnutls_aead_cipher_encryptv2() for GnuTLS > 3.6.14.
  • BUG #14467: s3:smbd: Fix %U substitutions if it contains a domain name.
  • Martin Schwenke <>
  • BUG #14466: ctdb disable/enable can fail due to race condition.
Release Notes Samba 4.12.8.

Samba 4.12.7

Release Notes for Samba 4.12.7
September 18, 2020

This is a security release in order to address the following defect:

  • CVE-2020-1472: Unauthenticated domain takeover via netlogon ("ZeroLogon").

The following applies to Samba used as domain controller only (most seriously the Active Directory DC, but also the classic/NT4-style DC).

Installations running Samba as a file server only are not directly affected by this flaw, though they may need configuration changes to continue to talk to domain controllers (see "file servers and domain members" below).

The netlogon protocol contains a flaw that allows an authentication bypass. This was reported and patched by Microsoft as CVE-2020-1472. Since the bug is a protocol level flaw, and Samba implements the protocol, Samba is also vulnerable.

However, since version 4.8 (released in March 2018), the default behaviour of Samba has been to insist on a secure netlogon channel, which is a sufficient fix against the known exploits. This default is equivalent to having 'server schannel = yes' in the smb.conf.

Therefore versions 4.8 and above are not vulnerable unless they have the smb.conf lines

'server schannel = no' 


'server schannel = auto'.

Samba versions 4.7 and below are vulnerable unless they have

'server schannel = yes' 

in the smb.conf.

Note: each domain controller needs the correct settings in its smb.conf.

Vendors supporting Samba 4.7 and below are advised to patch their installations and packages to add this line to the [global] section if their smb.conf file.

The 'server schannel = yes' smb.conf line is equivalent to Microsoft's 'FullSecureChannelProtection=1' registry key, the introduction of which we understand forms the core of Microsoft's fix.

Some domains employ third-party software that will not work with a 'server schannel = yes'. For these cases patches are available that allow specific machines to use insecure netlogon. For example, the following smb.conf:

  server schannel = yes
  server require schannel:triceratops$ = no
  server require schannel:greywacke$ = no

will allow only "triceratops$" and "greywacke$" to avoid schannel.

More details can be found here:


Changes since 4.12.6

  • Jeremy Allison <>
  • BUG #14497: CVE-2020-1472(ZeroLogon): s3:rpc_server/netlogon: Protect netr_ServerPasswordSet2 against unencrypted passwords.
  • Günther Deschner <>
  • BUG #14497: CVE-2020-1472(ZeroLogon): s3:rpc_server/netlogon: Support "server require schannel:WORKSTATION$ = no" about unsecure configurations.
  • Gary Lockyer <>
  • Stefan Metzmacher <>
  • BUG #14497: CVE-2020-1472(ZeroLogon): libcli/auth: Reject weak client challenges in netlogon_creds_server_init() "server require schannel:WORKSTATION$ = no".
Release Notes Samba 4.12.7.

Samba 4.12.6

Release Notes for Samba 4.12.6
August 13, 2020

This is the latest stable release of the Samba 4.12 release series.

Changes since 4.12.5

  • Jeremy Allison <>
  • BUG #14403: s3: libsmb: Fix SMB2 client rename bug to a Windows server.
  • Andrew Bartlett <>
  • BUG #14424: dsdb: Allow "password hash userPassword schemes = CryptSHA256" to work on RHEL7.
  • BUG #14450: dbcheck: Allow a dangling forward link outside our known NCs.
  • Ralph Boehme <>
  • BUG #14426: lib/debug: Set the correct default backend loglevel to MAX_DEBUG_LEVEL.
  • BUG #14428: PANIC: Assert failed in get_lease_type().
  • Bjoern Jacke <>
  • BUG #14422: util: Fix build on AIX by fixing the order of replace.h include.
  • Volker Lendecke <>
  • BUG #14355: srvsvc_NetFileEnum asserts with open files.
  • Stefan Metzmacher <>
  • BUG #14354: KDC breaks with DES keys still in the database and msDS-SupportedEncryptionTypes 31 indicating support for it.
  • BUG #14427: s3:smbd: Make sure vfs_ChDir() always sets conn->cwd_fsp->fh->fd = AT_FDCWD.
  • BUG #14428: PANIC: Assert failed in get_lease_type().
  • Andreas Schneider <>
  • BUG #14358: docs: Fix documentation for require_membership_of of pam_winbind.conf.
  • Martin Schwenke <>
  • BUG #14444: ctdb-scripts: Use nfsconf utility for variable values in CTDB NFS scripts.
  • Andrew Walker <>
  • BUG #14425: s3:winbind:idmap_ad: Make failure to get attrnames for schema mode fatal.
Release Notes Samba 4.12.6.

Samba 4.12.5

Release Notes for Samba 4.12.5
July 02, 2020

This is the latest stable release of the Samba 4.12 release series.

Changes since 4.12.4

  • Jeremy Allison <>
  • BUG #14301: Fix smbd panic on force-close share during async io.
  • BUG #14374: Fix segfault when using SMBC_opendir_ctx() routine for share folder that contains incorrect symbols in any file name.
  • BUG #14391: Fix DFS links.
  • Andrew Bartlett <>
  • BUG #14310: Can't use DNS functionality after a Windows DC has been in domain.
  • Alexander Bokovoy <>
  • Isaac Boukris <>
  • BUG #14396: Add net-ads-join dnshostname=fqdn option.
  • BUG #14406: Fix adding msDS-AdditionalDnsHostName to keytab with Windows DC.
  • Björn Jacke <>
  • BUG #14386: docs-xml: Update list of posible VFS operations for vfs_full_audit.
  • Volker Lendecke <>
  • BUG #14382: winbindd: Fix a use-after-free when winbind clients exit.
  • Andreas Schneider <>
  • BUG #14370: Client tools are not able to read gencache anymore.
Release Notes Samba 4.12.5.

Samba 4.12.4

Release Notes for Samba 4.12.4
July 02, 2020

This is a security release in order to address the following defects:

  • CVE-2020-10730: NULL pointer de-reference and use-after-free in Samba AD DC LDAP Server with ASQ, VLV and paged_results.
  • CVE-2020-10745: Parsing and packing of NBT and DNS packets can consume excessive CPU
  • CVE-2020-10760: LDAP Use-after-free in Samba AD DC Global Catalog with paged_results and VLV.
  • CVE-2020-14303: Empty UDP packet DoS in Samba AD DC nbtd.


A client combining the 'ASQ' and 'VLV' LDAP controls can cause a NULL pointer de-reference and further combinations with the LDAP paged_results feature can give a use-after-free in Samba's AD DC LDAP server.
Parsing and packing of NBT and DNS packets can consume excessive CPU.
The use of the paged_results or VLV controls against the Global Catalog LDAP server on the AD DC will cause a use-after-free.
The AD DC NBT server in Samba 4.0 will enter a CPU spin and not process further requests once it receives an empty (zero-length) UDP packet to port 137.

For more details, please refer to the security advisories.

Changes since 4.12.3

  • Douglas Bagnall <>
  • Andrew Bartlett <>
  • Gary Lockyer <>
  • BUG #14364: CVE-2020-10730: NULL de-reference in AD DC LDAP server when ASQ and VLV combined, ldb: Bump version to 1.5.8.
Release Notes Samba 4.12.4.

Samba 4.12.3

Release Notes for Samba 4.12.3
May 19, 2020

This is the latest stable release of the Samba 4.12 release series.

Changes since 4.12.2

  • Jeremy Allison <>
  • BUG #14301: Fix smbd panic on force-close share during async io.
  • BUG #14343: s3: vfs_full_audit: Add missing fcntl entry in vfs_op_names[] array.
  • BUG #14361: vfs_io_uring: Fix data corruption with Windows clients.
  • BUG #14372: Fix smbd crashes when MacOS Catalina connects if iconv initialization fails.
  • Ralph Boehme <>
  • BUG #14150: Exporting from macOS Adobe Illustrator creates multiple copies.
  • BUG #14256: smbd does a chdir() twice per request.
  • BUG #14320: smbd mistakenly updates a file's write-time on close.
  • BUG #14350: vfs_shadow_copy2: implement case canonicalisation in shadow_copy2_get_real_filename().
  • BUG #14375: Fix Windows 7 clients problem after upgrading samba file server.
  • Alexander Bokovoy <>
  • BUG #14359: s3: Pass DCE RPC handle type to create_policy_hnd.
  • Isaac Boukris <>
  • BUG #14155: Fix uxsuccess test with new MIT krb5 library 1.18.
  • BUG #14342: mit-kdc: Explicitly reject S4U requests.
  • Anoop C S <>
  • BUG #14352: dbwrap_watch: Set rec->value_valid while returning nested share_mode_do_locked().
  • Amit Kumar <>
  • BUG #14345: lib:util: Fix smbclient -l basename dir.
  • Volker Lendecke <>
  • Gary Lockyer <>
  • BUG #14330: ldb: Bump version to 2.1.3, LMDB databases can grow without bounds
  • Stefan Metzmacher <>
  • BUG #14361: vfs_io_uring: Fix data corruption with Windows clients.
  • Noel Power <>
  • BUG #14344: s3/librpc/crypto: Fix double free with unresolved credential cache.
  • Andreas Schneider <>
  • BUG #14358: docs-xml: Fix usernames in pam_winbind manpages.
Release Notes Samba 4.12.3.

Samba 4.12.2

Release Notes for Samba 4.12.2
April 28, 2020

This is a Security Release in order to address the following defects:



A client combining the 'ASQ' and 'Paged Results' LDAP controls can cause a use-after-free in Samba's AD DC LDAP server.


A deeply nested filter in an un-authenticated LDAP search can exhaust the LDAP server's stack memory causing a SIGSEGV.

For more details, please refer to the security advisories.

Changes since 4.12.1

  • Andrew Bartlett <>
  • Gary Lockyer <>
Release Notes Samba 4.12.2.

Samba 4.12.1

Release Notes for Samba 4.12.1
April 07, 2020

This is the latest stable release of the Samba 4.12 release series.

Changes since 4.12.0

  • Douglas Bagnall <>
  • BUG #14242: nmblib: avoid undefined behaviour in handle_name_ptrs().
  • Björn Baumbach <>
  • BUG #14296: samba-tool group: Handle group names with special chars correctly.
  • Ralph Boehme <>
  • BUG #14293: Add missing check for DMAPI offline status in async DOS attributes.
  • BUG #14295: Starting ctdb node that was powered off hard before results in recovery loop.
  • BUG #14307: smbd: Ignore set NTACL requests which contain S-1-5-88 NFS ACEs.
  • BUG #14316: vfs_recycle: Prevent flooding the log if we're called on non-existant paths.
  • Günther Deschner <>
  • BUG #14313: librpc: Fix IDL for svcctl_ChangeServiceConfigW.
  • BUG #14327: nsswitch: Fix use-after-free causing segfault in _pam_delete_cred.
  • Art M. Gallagher <>
  • BUG #13622: fruit:time machine max size is broken on arm.
  • Amitay Isaacs <>
  • BUG #14294: CTDB recovery corner cases can cause record resurrection and node banning.
  • Noel Power <>
  • BUG #14332: s3/utils: Fix double free error with smbtree.
  • Martin Schwenke <>
  • BUG #14294: CTDB recovery corner cases can cause record resurrection and node banning.
  • BUG #14295: Starting ctdb node that was powered off hard before results in recovery loop.
  • BUG #14324: CTDB recovery daemon can crash due to dereference of NULL pointer.

Samba 4.12.0

Release Notes for Samba 4.12.0
March 03, 2020

Release Announcements

This is the first stable release of the Samba 4.12 release series.

Please read the release notes carefully before upgrading.


Python 3.5 Required

Samba's minimum runtime requirement for python was raised to Python 3.4 with samba 4.11. Samba 4.12 raises this minimum version to Python 3.5 both to access new features and because this is the oldest version we test with in our CI infrastructure.

(Build time support for the file server with Python 2.6 has not changed)

Removing in-tree cryptography: GnuTLS 3.4.7 required

Samba is making efforts to remove in-tree cryptographic functionality, and to instead rely on externally maintained libraries. To this end, Samba has chosen GnuTLS as our standard cryptographic provider.

Samba now requires GnuTLS 3.4.7 to be installed (including development headers at build time) for all configurations, not just the Samba AD DC.

Thanks to this work Samba no longer ships an in-tree DES implementation and on GnuTLS 3.6.5 or later Samba will include no in-tree cryptography other than the MD4 hash and that implemented in our copy of Heimdal.

Using GnuTLS for SMB3 encryption you will notice huge performance and copy speed improvements. Tests with the CIFS Kernel client from Linux Kernel 5.3 show a 3x speed improvement for writing and a 2.5x speed improvement for reads!

NOTE WELL: The use of GnuTLS means that Samba will honour the system-wide 'FIPS mode' (a reference to the US FIPS-140 cryptographic standard) and so will not operate in many still common situations if this system-wide parameter is in effect, as many of our protocols rely on outdated cryptography.

A future Samba version will mitigate this to some extent where good cryptography effectively wraps bad cryptography, but for now that above applies.

zlib library is now required to build Samba

Samba no longer includes a local copy of zlib in our source tarball. By removing this we do not need to ship (even where we did not build) the old, broken zip encryption code found there.

New Spotlight backend for Elasticsearch

Support for the macOS specific Spotlight search protocol has been enhanced significantly. Starting with 4.12 Samba supports using Elasticsearch as search backend. Various new parameters have been added to configure this:

 spotlight backend = noindex | elasticsearch | tracker
 elasticsearch:address = ADDRESS
 elasticsearch:port = PORT
 elasticsearch:use tls = BOOLEAN
 elasticsearch:index = INDEXNAME
 elasticsearch:mappings = PATH
 elasticsearch:max results = NUMBER

Samba also ships a Spotlight client command "mdfind" which can be used to search any SMB server that runs the Spotlight RPC service. See the manpage of mdfind for details.

Note that when upgrading existing installations that are using the previous default Spotlight backend Gnome Tracker must explicitly set "spotlight backend = tracker" as the new default is "noindex".

"net ads kerberos pac save" and "net eventlog export"

The "net ads kerberos pac save" and "net eventlog export" tools will no longer silently overwrite an existing file during data export. If the filename given exits, an error will be shown.


A large number of fuzz targets have been added to Samba, and Samba has been registered in Google's oss-fuzz cloud fuzzing service. In particular, we now have good fuzzing coverage of our generated NDR parsing code.

A large number of issues have been found and fixed thanks to this effort.

'samba-tool' improvements add contacts as member to groups

Previously 'samba-tool group addmemers' can just add users, groups and computers as members to groups. But also contacts can be members of groups. Samba 4.12 adds the functionality to add contacts to groups. Since contacts have no sAMAccountName, it's possible that there are more than one contact with the same name in different organizational units. Therefore it's necessary to have an option to handle group members by their DN.

To get the DN of an object there is now the "--full-dn" option available for all necessary commands.

The MS Windows UI allows to search for specific types of group members when searching for new members for a group. This feature is included here with the new samba-tool group addmembers "--object-type=OBJECTYPE" option. The different types are selected accordingly to the Windows UI. The default samba-toole behaviour shouldn't be changed.

Allow filtering by OU or subtree in samba-tool

A new "--base-dn" and "--member-base-dn" option is added to relevant samba-tool user, group and ou management commands to allow operation on just one part of the AD tree, such as a single OU.



Samba now uses a sentinel value based on utimensat(2) UTIME_OMIT to denote to-be-ignored timestamp variables passed to the SMB_VFS_NTIMES() VFS function.

VFS modules can check whether any of the time values inside a struct smb_file_time is to be ignored by calling is_omit_timespec() on the value.

'io_uring' vfs module

The module makes use of the new io_uring infrastructure (intruduced in Linux 5.1), see

Currently this implements SMB_VFS_{PREAD,PWRITE,FSYNC}_SEND/RECV and avoids the overhead of the userspace threadpool in the default vfs backend. See also vfs_io_uring(8).

In order to build the module you need the liburing userspace library and its developement headers installed, see

At runtime you'll need a Linux kernel with version 5.1 or higher. Note that 5.4.14 and 5.4.15 have a regression that breaks the Samba module! The regression was fixed in Linux 5.4.16 again.

MS-DFS changes in the VFS

This release changes set getting and setting of MS-DFS redirects on the filesystem to go through two new VFS functions:


instead of smbd explicitly storing MS-DFS redirects inside symbolic links on the filesystem. The underlying default implementations of this has not changed, the redirects are still stored inside symbolic links on the filesystem, but moving the creation and reading of these links into the VFS as first-class functions now allows alternate methods of storing them (maybe in extended attributes) for OEMs who don't want to mis-use filesystem symbolic links in this way.

CTDB changes

  • The ctdb_mutex_fcntl_helper periodically re-checks the lock file
The re-check period is specified using a 2nd argument to this helper. The default re-check period is 5s.
If the file no longer exists or the inode number changes then the helper exits. This triggers an election.


smb.conf "write cache size"

The smb.conf parameter "write cache size" has been removed.

Since the in-memory write caching code was written, our write path has changed significantly. In particular we have gained very flexible support for async I/O, with the new linux io_uring interface in development. The old write cache concept which cached data in main memory followed by a blocking pwrite no longer gives any improvement on modern systems, and may make performance worse on memory-contrained systems, so this functionality should not be enabled in core smbd code.

In addition, it complicated the write code, which is a performance critical code path.

If required for specialist purposes, it can be recreated as a VFS module.

Retiring DES encryption types in Kerberos.

With this release, support for DES encryption types has been removed from Samba, and setting DES_ONLY flag for an account will cause Kerberos authentication to fail for that account (see RFC-6649).

Samba-DC: DES keys no longer saved in DB.

When a new password is set for an account, Samba DC will store random keys in DB instead of DES keys derived from the password. If the account is being migrated to Windbows or to an older version of Samba in order to use DES keys, the password must be reset to make it work.

Heimdal-DC: removal of weak-crypto.

Following removal of DES encryption types from Samba, the embedded Heimdal build has been updated to not compile weak crypto code (HEIM_WEAK_CRYPTO).

vfs_netatalk: The netatalk VFS module has been removed.

The netatalk VFS module has been removed. It was unmaintained and is not needed any more.

BIND9_FLATFILE deprecated

The BIND9_FLATFILE DNS backend is deprecated in this release and will be removed in the future. This was only practically useful on a single domain controller or under expert care and supervision.

This release removes the 'rndc command' smb.conf parameter, which supported this configuration by writing out a list of DCs permitted to make changes to the DNS Zone and nudging the 'named' server if a new DC was added to the domain. Administrators using BIND9_FLATFILE will need to maintain this manually from now on.

smb.conf changes

 Parameter Name                     Description                Default
 --------------                     -----------                -------
 elasticsearch:address              New                        localhost
 elasticsearch:port                 New                        9200
 elasticsearch:use tls              New                        No
 elasticsearch:index                New                        _all
 elasticsearch:mappings             New                        DATADIR/elasticsearch_mappings.json
 elasticsearch:max results          New                        100
 nfs4:acedup                        Changed default            merge
 rndc command                       Removed
 write cache size                   Removed
 spotlight backend		     New			noindex


  • Andrew Bartlett <>
  • BUG #14258: dsdb: Correctly handle memory in objectclass_attrs.


  • Jeremy Allison <>
  • BUG #14269: s3: DFS: Don't allow link deletion on a read-only share.
  • Douglas Bagnall <>
  • BUG #14284: pidl/wscript: configure should insist on Parse::Yapp::Driver.
  • Andrew Bartlett <>
  • BUG #14270: ldb: Fix search with scope ONE and small result sets.
  • BUG #14284: build: Do not check if system perl modules should be bundled.
  • Volker Lendecke <>
  • BUG #14285: smbd fails to handle EINTR from open(2) properly.
  • Stefan Metzmacher <>


  • Jeremy Allison <>
  • BUG #14282: Set getting and setting of MS-DFS redirects on the filesystem to go through two new VFS functions SMB_VFS_CREATE_DFS_PATHAT() and SMB_VFS_READ_DFS_PATHAT().
  • Andrew Bartlett <>
  • BUG #14255: bootstrap: Remove un-used dependency python3-crypto.
  • Volker Lendecke <>
  • BUG #14247: Fix CID 1458418 and 1458420.
  • BUG #14281: lib: Fix a shutdown crash with "clustering = yes".
  • Stefan Metzmacher <>
  • BUG #14247: Winbind member (source3) fails local SAM auth with empty domain name.
  • BUG #14265: winbindd: Handle missing idmap in getgrgid().
  • BUG #14271: Don't use forward declaration for GnuTLS typedefs.
  • BUG #14280: Add io_uring vfs module.
  • Andreas Schneider <>
  • BUG #14250: libcli:smb: Improve check for gnutls_aead_cipher_(en|de)cryptv2.


  • Jeremy Allison <>
  • BUG #14239: s3: lib: nmblib. Clean up and harden nmb packet processing.
  • Andreas Schneider <>
  • BUG #14253: lib:util: Log mkdir error on correct debug levels.