Data corruption when multiple users perform read and write operations to a shared file in the SMB2 environment

Support for Windows Vista Service Pack 1 (SP1) ends on July 12, 2011. To continue receiving security updates for Windows, make sure you're running Windows Vista with Service Pack 2 (SP2). For more information, refer to this Microsoft web page: Support is ending for some versions of Windows.

Symptoms

Assume that you configure a network environment that uses the Server Message Block (SMB) Version 2 protocol. In this network, data corruption occurs when multiple users perform read and write operations to the same file on a network share. Specifically, the data from one user overwrites the data from the other users.

Note By default, the SMB2 protocol is enabled in the following operating systems:

  • Windows 7

  • Windows Server 2008 R2

  • Windows Vista

  • Windows Server 2008



For more information about how to reproduce this issue, see the "More information" section.

Cause

This issue occurs because a user queries the local cache for attributes of a shared file regardless of the opportunistic lock status in the SMB2 environment. When other users change the shared file, the original user obtains incorrect file attributes if the local cache is not updated in time. Therefore, a data corruption issue occurs.

Resolution

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=supportNote The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, you must be running one of the following operating systems:

  • Windows Vista Service Pack 1 (SP1)

  • Windows Vista Service Pack 2 (SP2)

  • Windows Server 2008

  • Windows Server 2008 Service Pack 2 (SP2)

  • Windows 7

  • Windows Server 2008 R2


Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

Restart requirement

You may have to restart the computer after you apply this hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows Vista and Windows Server 2008 file information notes

Important Windows Vista hotfixes and Windows Server 2008 hotfixes are included in the same packages. However, only "Windows Vista" is listed on the Hotfix Request page. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows Vista" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

  • The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.

    Version

    Product

    SR_Level

    Service branch

    6.0.600
    1.
    22xxx

    Windows Vista and Windows Server 2008

    SP1

    LDR

    6.0.600
    2.
    22xxx

    Windows Vista and Windows Server 2008

    SP2

    LDR

  • Service Pack 1 is integrated into the release version of Windows Server 2008. Therefore, RTM milestone files apply only to Windows Vista. RTM milestone files have a 6.0.0000.xxxxx version number.

  • The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. MUM files and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Server 2008 and of Windows Vista

File name

File version

File size

Date

Time

Platform

Mrxsmb20.sys

6.0.6001.22718

79,360

24-Jun-2010

13:02

x86

Mrxsmb20.sys

6.0.6002.22431

80,384

24-Jun-2010

13:21

x86

For all supported x64-based versions of Windows Server 2008 and of Windows Vista

File name

File version

File size

Date

Time

Platform

Mrxsmb20.sys

6.0.6001.22718

106,496

24-Jun-2010

13:22

x64

Mrxsmb20.sys

6.0.6002.22431

107,520

24-Jun-2010

13:34

x64

For all supported IA-64-based versions of Windows Server 2008

File name

File version

File size

Date

Time

Platform

Mrxsmb20.sys

6.0.6001.22718

263,168

24-Jun-2010

13:05

IA-64

Mrxsmb20.sys

6.0.6002.22431

265,728

24-Jun-2010

13:19

IA-64

Windows 7 and Windows Server 2008 R2 file information notes

Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

  • The MANIFEST files (.manifest) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MANIFEST files and the associated security catalog (.cat) files, are very important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows 7

File name

File version

File size

Date

Time

Platform

Mrxsmb20.sys

6.1.7600.20714

95,744

17-May-2010

22:28

x86


For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Mrxsmb20.sys

6.1.7600.20714

126,464

17-May-2010

22:53

x64

For all supported IA-64-based versions of Windows Server 2008 R2

File name

File version

File size

Date

Time

Platform

Mrxsmb20.sys

6.1.7600.20714

305,664

17-May-2010

21:53

IA-64



Workaround

To work around this issue, disable or reduce the time-out threshold for the local cache update by modifying the registry. To do this, follow these steps:

  1. Click Start, click Run, type Regedit, and then press ENTER.

  2. Locate the following registry subkey:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanWorkstation\Parameters

  3. Under this registry subkey, right-click FileInfoCacheLifetime, and then click Modify.

  4. Under Base, click Decimal, and then type a number that is smaller than the number that appears in the Value date box.

    Notes

    • Type 0 to disable the time-out threshold for the local cache update.

    • The number that you type indicates the length in second of the time-out threshold for local cache update.

Note If you use this method, the network traffic will increase.

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


More Information

Steps to reproduce this problem

To reproduce this problem, set up the following scenario:

  • User1 on machine1 opens a shared file.

  • User2 on machine2 opens the same shared file and then writes to this file.

In this scenario, the data attributes of the shared file that are cached on machine1 are not kept in sync. When user1 changes the shared file, the local file information cache does not reflect the updated information that was entered by user2. Therefore, the changes that are made by user1 overwrite the data from user2.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional file information

Additional file information for Windows Vista and for Windows Server 2008

Additional files for all supported x86-based versions of Windows Vista and of Windows Server 2008

File name

X86_274b2124864fda06ae1a882d9d72ed50_31bf3856ad364e35_6.0.6002.22431_none_48e5540ff06ad7e0.manifest

File version

Not applicable

File size

701

Date (UTC)

25-Jun-2010

Time (UTC)

05:32

Platform

Not applicable

File name

X86_c0933876011a14191d6a8e168f09f637_31bf3856ad364e35_6.0.6001.22718_none_1373df0a7d2f09b0.manifest

File version

Not applicable

File size

701

Date (UTC)

25-Jun-2010

Time (UTC)

05:32

Platform

Not applicable

File name

X86_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.0.6001.22718_none_8b61d02ea2e45653.manifest

File version

Not applicable

File size

6,960

Date (UTC)

24-Jun-2010

Time (UTC)

15:10

Platform

Not applicable

File name

X86_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.0.6002.22431_none_8d2ba038a02131f8.manifest

File version

Not applicable

File size

6,960

Date (UTC)

24-Jun-2010

Time (UTC)

16:23

Platform

Not applicable

Additional files for all supported x64-based versions of Windows Vista and of Windows Server 2008

File name

Amd64_095009b1db40032261911eaf96c33ddf_31bf3856ad364e35_6.0.6002.22431_none_a2a6525a41574894.manifest

File version

Not applicable

File size

705

Date (UTC)

25-Jun-2010

Time (UTC)

05:32

Platform

Not applicable

File name

Amd64_77dedcd524ebfb3018baef9c219c3742_31bf3856ad364e35_6.0.6001.22718_none_4c96696e98302385.manifest

File version

Not applicable

File size

705

Date (UTC)

25-Jun-2010

Time (UTC)

05:32

Platform

Not applicable

File name

Amd64_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.0.6001.22718_none_e7806bb25b41c789.manifest

File version

Not applicable

File size

6,972

Date (UTC)

24-Jun-2010

Time (UTC)

15:37

Platform

Not applicable

File name

Amd64_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.0.6002.22431_none_e94a3bbc587ea32e.manifest

File version

Not applicable

File size

6,972

Date (UTC)

24-Jun-2010

Time (UTC)

16:39

Platform

Not applicable

Additional files for all supported IA-64-based versions of Windows Server 2008

File name

Ia64_19432ea5e5a7a1ef00684b2853fe9394_31bf3856ad364e35_6.0.6002.22431_none_2e292dd0a0cd7496.manifest

File version

Not applicable

File size

703

Date (UTC)

25-Jun-2010

Time (UTC)

05:32

Platform

Not applicable

File name

Ia64_27bd75126997a150fa118414223c5434_31bf3856ad364e35_6.0.6001.22718_none_b784eed10a712d8a.manifest

File version

Not applicable

File size

703

Date (UTC)

25-Jun-2010

Time (UTC)

05:32

Platform

Not applicable

File name

Ia64_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.0.6001.22718_none_8b637424a2e25f4f.manifest

File version

Not applicable

File size

6,966

Date (UTC)

24-Jun-2010

Time (UTC)

15:04

Platform

Not applicable

File name

Ia64_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.0.6002.22431_none_8d2d442ea01f3af4.manifest

File version

Not applicable

File size

6,966

Date (UTC)

24-Jun-2010

Time (UTC)

15:59

Platform

Not applicable

Win7

Additional file information for Windows 7 and for Windows Server 2008 R2

Additional files for all supported x86-based versions of Windows 7

File name

X86_ab0ed5ad8223e31af1ad03694281c339_31bf3856ad364e35_6.1.7600.20714_none_e0a873196f594bcd.manifest

File version

Not applicable

File size

701

Date (UTC)

18-May-2010

Time (UTC)

17:22

Platform

Not applicable


File name

X86_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.1.7600.20714_none_8b859d6603ff30b8.manifest

File version

Not applicable

File size

4,035

Date (UTC)

18-May-2010

Time (UTC)

04:31

Platform

Not applicable

Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

File name

Amd64_9faac1c9c226641843cf13140e2bf798_31bf3856ad364e35_6.1.7600.20714_none_8b6624ba659459ea.manifest

File version

Not applicable

File size

705

Date (UTC)

18-May-2010

Time (UTC)

17:22

Platform

Not applicable


File name

Amd64_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.1.7600.20714_none_e7a438e9bc5ca1ee.manifest

File version

Not applicable

File size

4,039

Date (UTC)

18-May-2010

Time (UTC)

09:00

Platform

Not applicable

Additional files for all supported IA-64-based versions of Windows Server 2008 R2

File name

Ia64_932de067902ca87c73235f9097960df8_31bf3856ad364e35_6.1.7600.20714_none_be35aaf898e7bada.manifest

File version

Not applicable

File size

703

Date (UTC)

18-May-2010

Time (UTC)

17:22

Platform

Not applicable


File name

Ia64_microsoft-windows-smb20-minirdr_31bf3856ad364e35_6.1.7600.20714_none_8b87415c03fd39b4.manifest

File version

Not applicable

File size

4,037

Date (UTC)

18-May-2010

Time (UTC)

04:26

Platform

Not applicable


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