Svchost.exe running NSI service leaks memory and non-paged pool memory leak Tag NSpc

Hotfix information

A supported hotfix is available from Microsoft Support. 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:

http://support.microsoft.com/contactus/?ws=support

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 have Service Pack 1 for Windows 7 or Windows Server 2008 R2 installed.

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.

Windows 7 and Windows Server 2008 R2 file information and 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 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
  6.1.760 0. 16 xxx	Windows 7 and Windows Server 2008 R2	RTM	GDR
  6.1.760 1. 22 xxx	Windows 7 and Windows Server 2008 R2	SP1	LDR

  
  
• GDR service branches contain only those fixes that are widely released to address widespread, extremely important issues. LDR service branches contain hotfixes in addition to widely released fixes.
• 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 7 and Windows Server 2008 R2" section.
• MUM 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 7

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

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

Additional file information for Windows 7 and Windows Server 2008 R2

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

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

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

Workaround

To work around this problem, use one of the following workarounds as appropriate for your situation.

Workaround for Scenario 1

Make sure that the application, such as ping.exe, is not forcibly stopped. Instead, let the application gracefully shutdown.

Alternatively, upgrade to Windows Server 2012. This problem is fixed in Windows Server 2012. This fix prevents the NSI service from leaking memory regardless of how the application is stopped.

Workaround for Scenario 2

A software developer should create multiple ICMP handles to send ICMP requests. If you must send a large number of ICMP packets, you should use Raw sockets and directly send and receive ICMP packets on the RAW socket. This will give fastest performance.

Workaround for Scenario 3

In this scenario, if you disable and enable the network adapter, the memory usage immediately decreases but has a short spike of CPU usage.

This occurs because when a change occurs in the IP address or the interface, the NSI service is notified by the kernel. The NSI service then tries to notifiy all the clients that are registered for the notification. When the service tries to notify a client process that does not exist, the RPC reports an error. Therefore, the NSI service deletes all the state information that was saved for that client process. After this occurs, that memory is freed.

In this case, several hundred thousand notifications are registered. After the event occurs, all the memory for these invalid clients is freed.

This problem is fixed in Windows 8.