Transferring files by using SMB2 or SMB3 causes memory leak on a Windows computer

Applies to: Windows 8.1 EnterpriseWindows 8.1Windows 8.1 Pro

Symptoms


When multiple users repeatedly transfer files with explicit credentials on a computer that is running Windows 8.1, Windows Server 2012 R2, Windows 8 or Windows Server 2012 by using Server Message Block version 2 (SMB2) or SMB3 protocol, it will cause a memory leak, and then the nonpaged pool memory will be exhausted.


Cause


When an SMB2 or an SMB3 session has explicit credentials, it will hold a reference to the credential object. However, currently the cleanup for the session entry does not remove the reference. Therefore, the credential object becomes leaked.

Resolution


To resolve this issue for Windows 8.1 and Windows Server 2012 R2, install update 2919355.
To resolve this issue for Windows 8 and Windows Server 2012, install the hotfix that is described in this article.

Update information for Windows 8.1 and Windows Server 2012 R2

For more information about how to obtain update 2919355, click the following article number to view the article in the Microsoft Knowledge Base:
2919355 Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 Update April, 2014

Hotfix information for Windows 8 or Windows Server 2012

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, go to the following Microsoft website:
Note 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:
  • Windows 8
  • Windows Server 2012

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any previously released hotfix.

File information

The English (United States) 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.

Status


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

Additional file information


References


See the terminology Microsoft uses to describe software updates for more information.