Linux Today: Linux News On Internet Time.
Search Linux Today
Linux News Sections:  Developer -  High Performance -  Infrastructure -  IT Management -  Security -  Storage -
Linux Today Navigation
LT Home
Contribute
Contribute
Link to Us
Linux Jobs


Top White Papers

  • Corporate e-Learning technology has a long and diverse pedigree. As far back as the 1980s, companies were adopting computer-based training to supplement...
    Download

  • With 81% of employees using their phones at work, companies have stopped asking: "Is corporate data leaking from personal devices?" and started asking:...
    Download

More on LinuxToday


Samba 2.2.2 released

Oct 14, 2001, 08:42 (8 Talkback[s])
Subject: Samba 2.2.2 released
From: jra@samba.org (Jeremy Allison)
Date: Sat, 13 Oct 2001 16:22:20 -0700

The Samba Team is proud to announce the release of Samba 2.2.2.

This is the latest stable release of Samba. This is the version that all
production Samba servers should be running for all current bug-fixes.

There are several important oplock logic bugs that have been fixed in
this release, so an upgrade is recommended.

Binary packages will be released shortly for major platforms. The source
code can be downloaded from :

ftp://ftp.samba.org/pub/samba/

in the file samba-2.2.2.tar.gz/.

The release notes follow.

As always, all bugs are our responsibility.

Regards,

        The Samba Team.

----------------------------------------------------------------------------
              WHATS NEW IN Samba 2.2.2: 13th October 2001
              ===========================================

This is the latest stable release of Samba. This is the version that all
production Samba servers should be running for all current bug-fixes.

There are several important oplock logic bugs that have been fixed in
this release, so an upgrade is recommended.

New daemon included - winbindd
------------------------------

Samba 2.2.2 is the first release to include the winbind daemon.
This code allows UNIX systems that implement the name service
switch (nss) to be entered into a Windows NT/2000 domain and
use the Domain controller for all user and group enumeration.

This allows a Samba server added to a Windows domain to serve
file and print services with NO local users needed in /etc/passwd
and /etc/group - all users and groups are read directly from the
Windows domain controller. In addition with pam_winbind which allows
a PAM enabled UNIX system to use a Windows domain for authentication
service this allows single sign on and account control across
UNIX and Windows systems.

The current version of winbindd shipped in 2.2.2 does have some
memory leaks, which will be addressed for the next Samba release,
so it is advisable to monitor the winbind process. This code is
being used in production by several vendors, so the leaks are
managable. In addition, this version of winbind does not work
correctly against a Samba PDC, due to some missing calls on the
PDC side. These problems are being addressed for the next Samba
release, but it was thought better to release the code now rather
than delay the main Samba code to match the winbind release schedule.

For more information on using winbind, see the man pages for 
winbindd and wbinfo.

Note that winbindd is not installed by default.

New/Changed parameters in 2.2.2
-------------------------------

For more information on these parameters, see the man pages for
smb.conf.

Added/changed parameters.
-------------------------

strict allocate

Causes Samba not to create UNIX 'sparse' files, but to follow the
Windows behaviour of always allocating on-disk space.

use mmap

Set to 'on' by default, only set to 'off' on HPUX 11.x or below or other
UNIX systems that don't have coherent mmap/read-write internal caches.
You should not need to set this parameter.

nt acl support

This parameter has been changed to a per-share option, and is very
useful in enabling Windows 2000 SP2 to load/save profiles from a 
Samba share.

New printing parameters.
------------------------

disable spoolss

Setting this parameter causes Samba to go back to the old 2.0.x
LANMAN printing behaviour, for people who wish to disable the
new SPOOLSS pipe.

use client driver

Causes Windows NT/2000 clients to need have a local printer driver
installed and to treat the printer as local.

New LDAP parameters.
--------------------

Samba 2.2.2 contains new code to maintain a Samba SAM database
on a remote LDAP server. These parameters have been added as
part of this code. These parameters are only available when Samba
has been compiled with the --with-ldapsam option.

ldap admin dn
ldap ssl

New SSL parameters.
-------------------

The SSL support in Samba has been fixed. These new parameters
are part of the changes added. These parameters are only available
when Samba has been compiled with the --with-ssl option. 
Please see the smb.conf man page for details.

ssl egd socket
ssl entropy file
ssl entropy bytes

New winbindd parameters.
------------------------

These parameters are used by winbindd. See the man page for
winbindd for details.

winbind separator
winbind uid
winbind gid
winbind cache time
winbind enum users
winbind enum groups
template homedir
template shell

Removed parameters.
-------------------

share modes
ldap root
ldap root passwd

New Documentation.
------------------

Some new README's have been added in the docs/ directory. These cover
using roving profiles with Windows 2000 SP2 (docs/README.Win2kSP2),
and how to use Samba to help prevent Windows virus spread
(docs/README.Win32-Viruses).

Quota problems on a Linux 2.4 kernel.
-------------------------------------

Currently the quota interfaces have diverged between the Linus
2.4.x kernels and the Alan Cox 2.4.x kernels (the Alan Cox varients
are shipped with RedHat). Running quota-enabled Samba compiled on
an Alan Cox kernel works correctly on an Alan Cox kernel (the one
shipped by default with RedHat 7.x) but fails on a Linus kernel.

This is a mess, and hopefully Alan and Linus will sort it out soon.
In the meantime we need to ship.....

Changes in 2.2.2
-----------------

1). mmap tdb code disabled on HPUX. This should prevent the reports of
tdb corruption on HUPX.
2). Large file support set to off in Solaris 5.5 and below.
3). Better CUPS detection.
4). New SAM (password database) backends - smbpasswd (traditional),
LDAP, NIS+ and Samba TDB.
5). Quota fixups on Linux.
6). libsmbclient stand-alone code added. Can be built as a shared library
under Linux.
7). Tru64 ACL suppport added.
8). winbindd option added.
9). Realloc fail tidyup fixes all over the code.
10). Large improvement in hash table code efficiency - would be found with
large stat caches.
11). Error code consistency improved (still needs more work).
12). Profile shared memory support added to nmbd.
13). New Windows 2000/NT passthrough info levels added.
14). readraw/writeraw code rewritten - many bugs fixed.
15). UNIX password sync (non pam) code fixed, use correct wildcard matcher.
16). Reverse DNS lookup avoided on socket open.
17). Bug preventing nmbd re-registering names on WINS server timeout fixed.
18). Zero length byte range lock code added. Much closer to Windows semantics.
19). Alignment fault fixes for Linux/Alpha.
20). Error checking on tdb returns vastly improved.
21). Handling of delete on close fixed. No longer possible to leave 'dead'
file entries.
22). Handling of oplock break failure cleanups improved. Should not be
able to leave 'dead' entries.
23). Fix handling of errors trying to set 64 bit locks on 32 bit NFS mounts.
24). Misc. MS-DFS code fixes.
25). Ignore logon packets if not a PDC (needed for PDC/BDC failover).
26). winbind pam module added.
27). Order N^^2 enumeration of printers problem fixed.
28). Password backend database code re-ordered to allow different password
backends (at compile time currently).
29). Improved print driver version detection for Windows 2000.
30). Driver DEVMODE initialization fixes.
31). Improved SYSV print parse code.
32). Fixed enumeration of large numbers of users/groups from Windows clients.
Code still too slow.
33). Fix for buggy NetApp RPC pipe clients.
34). Fix for NT sending multiple SetPrinterDataEx calls.
35). Fix for logic bug where smbd could delay oplock break request messages
from other smbd daemons whilst client kept us busy.
36). Fix deadlock problem with connections tdb on enumeration.
37). Fixes for setting/getting NT ACLs - improved POSIX mapping both ways.
38). Removed unused readbmpx/writebmpx code.
39). Attempt to fix Linux 2.4.x quota mess.
40). Improved ctemp code for Windows 2000 compatibilty.
41). Finally understood difference between set EOF and set allocation requests.
Added strict allocate parameter to help.
42). Correctly return name types on name to SID lookups.
43). tdb spinlock code update.
44). Use pread/pwrite on systems that have it to fix race condition in tdb code.

Older release notes for Samba 2.2.x follow.

-----------------------------------------------------------------------------
The release notes for 2.2.1a follow :

This is a minor bugfix release for 2.2.1, NOT security related.

1). 2.2.1 had a bug where using smbpasswd -m to add a Windows NT or
Windows2000 machine into a Samba hosted PDC would fail due to our
stricter user name checking. We were disallowing user names
containing '$', which is needed when using smbpasswd to add a
machine into a domain. Automatically adding machines (using the
native Windows tools) into a Samba domain worked correctly.

2.2.1a fixes this single problem.

-----------------------------------------------------------------------------
The release notes for 2.2.1 follow :

New/Changed parameters in 2.2.1
-------------------------------

Added parameters.
-----------------

obey pam restrictions

When Samba is configured to use PAM, turns on or off Samba checking
the PAM account restrictions. Defaults to off.

pam password change

When Samba is configured to use PAM, turns on or off Samba passing
the password changes to PAM. Defaults to off.

large readwrite

New option to allow new Windows 2000 large file (64k) streaming
read/write options. Needs a 64 bit underlying operating system
(for Linux use kernel 2.4 with glibc 2.2 or above). Can improve performance
by 10% with Windows 2000 clients. Defaults to off. Not as tested
as some other Samba code paths.

hide unreadable

Prevents clients from seeing the existance of files that cannot
be read. Off by default.

enhanced browsing

Turn on/off the enhanced Samba browing functionality (*1B names).
Default is "on". Can prevent eternal machines in workgroups when
WINS servers are not synchronised.

Removed parameters.
-------------------

domain groups
domain admin users
domain guest users

Changes in 2.2.1
-----------------

1). "find" command removed for smbclient. Internal code now used.
2). smbspool updates to retry connections from Michael Sweet.
3). Fix for mapping 8859-15 characters to UNICODE.
4). Changed "security=server" to try with invalid username to prevent
    account lockouts.
5). Fixes to allow Windows 2000 SP2 clients to join a Samba PDC.
6). Support for Windows 9x Nexus tools to allow security changes from Win9x.
7). Two locking fixes added. Samba 2.2.1 now passes the Clarion network
    lock tester tool for distributed databases.
8). Preliminary support added for Windows 2000 large file read/write SMBs.
9). Changed random number generator in Samba to prevent guess attacks.
10). Fixes for tdb corruption in connections.tdb and file locking brlock.tdb.
     smbd's clean the tdb files on startup and shutdown.
11). Fixes for default ACLs on Solaris.
12). Tidyup of password entry caching code.
13). Correct shutdowns added for send fails. Helps tdb cleanup code.
14). Prevent invalid '/' characters in workgroup names.
15). Removed more static arrays in SAMR code.
16). Client code is now UNICODE on the wire.
17). Fix 2 second timstamp resolution everywhere if dos timestamp set to yes.
18). All tdb opens now going through logging function.
19). Add pam password changing and pam restrictions code.
20). Printer driver management improvements (delete driver).
21). Fix difference between NULL security descriptors and empty
     security descriptors.
22). Fix SID returns for server roles.
23). Allow Windows 2000 mmc to view and set Samba share security descriptors.
24). Allow smbcontrol to forcibly disconnect a share.
25). tdb fixes for HPUX, OpenBSD and other OS's that don't have a coherent
     mmap/file read/write cache.
26). Fix race condition in returning create disposition for file create/open.
27). Fix NT rewriting of security descriptors to their canonical form for
     ACLs.
28). Fix for Samba running on top of Linux VFAT ftruncate bug.
29). Swat fixes for being run with xinetd that doesn't set the umask.
30). Fix for slow writes with Win9x Explorer clients. Emulates Microsoft
     TCP stack early ack specification error.
31). Changed lock & persistant tdb directory to /var/cache/samba by default on
     RedHat and Mandrake as they clear the /var/lock/samba directory on reboot.

-----------------------------------------------------------------------------
The release notes for 2.2.0a follow :

SECURITY FIX
============

This is a security bugfix release for Samba 2.2.0. This release provides the
following two changes ONLY from the 2.2.0 release.

1). Fix for the security hole discovered by Michal Zalewski (lcamtuf@bos.bindview.com)
    and described in the security advisory below.
2). Fix for the hosts allow/hosts deny parameters not being honoured.

No other changes are being made for this release to ensure a security fix only.
For new functionality (including these security fixes) download Samba 2.2.1
when it is available.

The security advisory follows :


                IMPORTANT: Security bugfix for Samba
                ------------------------------------

June 23rd 2001


Summary
-------

A serious security hole has been discovered in all versions of Samba
that allows an attacker to gain root access on the target machine for
certain types of common Samba configuration.

The immediate fix is to edit your smb.conf configuration file and
remove all occurances of the macro "%m". Replacing occurances of %m
with %I is probably the best solution for most sites.

Details
-------

A remote attacker can use a netbios name containing unix path
characters which will then be substituted into the %m macro wherever
it occurs in smb.conf. This can be used to cause Samba to create a log
file on top of an important system file, which in turn can be used to
compromise security on the server.

The most commonly used configuration option that can be vulnerable to
this attack is the "log file" option. The default value for this
option is VARDIR/log.smbd. If the default is used then Samba is not
vulnerable to this attack.

The security hole occurs when a log file option like the following is
used:

  log file = /var/log/samba/%m.log

In that case the attacker can use a locally created symbolic link to
overwrite any file on the system. This requires local access to the
server.

If your Samba configuration has something like the following:

  log file = /var/log/samba/%m

Then the attacker could successfully compromise your server remotely
as no symbolic link is required. This type of configuration is very
rare.

The most commonly used log file configuration containing %m is the
distributed in the sample configuration file that comes with Samba:

  log file = /var/log/samba/log.%m

in that case your machine is not vulnerable to this attack unless you
happen to have a subdirectory in /var/log/samba/ which starts with the
prefix "log."

Credit
------

Thanks to Michal Zalewski (lcamtuf@bos.bindview.com) for finding this
vulnerability.


New Release
-----------

While we recommend that vulnerable sites immediately change their
smb.conf configuration file to prevent the attack we will also be
making new releases of Samba within the next 24 hours to properly fix
the problem. Please see http://www.samba.org/ for the new releases.

Please report any attacks to the appropriate authority.

        The Samba Team
        security@samba.org

---------------------------------------------------------------------------

The release notes for 2.2.0 follow :

This is the official Samba 2.2.0 release. This version of Samba provides
the following new features and enhancements.

Integration between Windows oplocks and NFS file opens (IRIX and Linux
2.4 kernel only). This gives complete data and locking integrity between
Windows and UNIX file access to the same data files.

Ability to act as an authentication source for Windows 2000 clients as
well as for NT4.x clients.

Integration with the winbind daemon that provides a single
sign on facility for UNIX servers in Windows 2000/NT4 networks
driven by a Windows 2000/NT4 PDC. winbind is not included in
this release, it currently must be obtained separately. We are
committed to including winbind in a future Samba 2.2.x release.

Support for native Windows 2000/NT4 printing RPCs. This includes
support for automatic printer driver download.

Support for server supported Access Control Lists (ACLs).
This release contains support for the following filesystems: 

    Solaris 2.6+ 
    SGI Irix 
    Linux Kernel with ACL patch from http://acl.bestbits.at
        Linux Kernel with XFS ACL support.
        Caldera/SCO UnixWare
        IBM AIX
        FreeBSD (with external patch)

Other platforms will be supported as resources are
available to test and implement the encessary modules. If
you are interested in writing the support for a particular
ACL filesystem, please join the samba-technical mailing
list and coordinate your efforts. 
 
On PAM (Pluggable Authentication Module) based systems - better debugging
messages and encrypted password users now have access control verified via
PAM - Note: Authentication still uses the encrypted password database.
 
Rewritten internal locking semantics for more robustness.
This release supports full 64 bit locking semantics on all
(even 32 bit) platforms. SMB locks are mapped onto POSIX
locks (32 bit or 64 bit) as the underlying system allows.

Conversion of various internal flat data structures to use
database records for increased performance and
flexibility. 

Support for acting as a MS-DFS (Distributed File System) server.

Support for manipulating Samba shares using Windows client tools
(server manager). Per share security can be set using these tools
and Samba will obey the access restrictions applied.

Samba profiling support (see below).

Compile time option for enabling a (Virtual file system) VFS layer 
to allow non-disk resources to be exported as Windows filesystems
(such as databases etc.).

The documentation in this release has been updated and converted
from Yodl to DocBook 4.1. There are many new parameters since 2.0.7
and some defaults have changed.

Profiling support.
------------------
Support for collection of profile information. A shared 
memory area has been created which contains counters for
the number of calls to and the amount of time spent in
various system calls, smb transactions and nmbd activity. See 
the file profile.h for a complete listing of the information 
collected. Sample code for a samba pmda (collection agent
for Performance Co-Pilot) has been included in the pcp
directory. 

To enable the profile data collection code in samba, you must 
compile samba with profile data support (run configure with 
the --with-profiling-data option). On startup, collection of 
data is disabled. To begin collecting data use the smbcontrol
program to turn on profiling (see the smbcontrol man page).
Profile information collection can be enabled for nmbd, all smbd
processes or one or more selected processes. The profiling
data collected is the aggragate for all processes that have
profiling enabled.

With samba compiled for profile data collection, you may see
a very slight degradation in performance even with profiling
collection turned off. On initial tests with NetBench on an
SGI Origin 200 server, this degradation was not measureable 
with profile collection off compared to no profile collection
compiled into samba. 

With count profile collection enabled on all clients, the 
degradation was less than 2%. With full profile collection 
enabled on all clients, the degradation was about 8.5%. 

=====================================================================

If you think you have found a bug please email a report to :

        samba@samba.org

As always, all bugs are our responsibility.

Regards,

        The Samba Team.