DOCUMENT:Q272913 08-MAY-2002 [winnt] TITLE :CreateRemoteThread May Leak Handle in Windows NT Terminal Server PRODUCT :Microsoft Windows NT PROD/VER::4.0 SP6 OPER/SYS: KEYWORDS:kbenv kbtool kbWinNT400PreSP7Fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0 SP6, Terminal Server Edition ------------------------------------------------------------------------------- SYMPTOMS ======== The CreateRemoteThread() Application Programming Interface (API) may leak a handle when the call is unsuccessful and returns a NULL handle. This increases the handle count of the process that called the CreateRemoteThread() function. Because the handle is NULL, the calling process cannot close the handle, and this causes a memory leak. NOTE: To detect the handle leak, use Performance Monitor and monitor the handle count for the process that calls the CreateRemoteThread() API. CAUSE ===== The CreateRemoteThread function first successfully creates a thread where it creates a thread handle. If the function is unsuccessful in the later stages of processing, the created thread is terminated and the open handle to this thread is not closed. This open handle causes a memory leak. RESOLUTION ========== A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. This fix may receive additional testing at a later time, to further ensure product quality. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows NT 4.0 service pack that contains this fix. To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, please go to the following address on the World Wide Web: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS NOTE: In special cases, charges that are normally incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. Normal support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this fix should have the following file attributes or later: Date Time Size File name Platform ------------------------------------------------------------- 11/18/1999 06:19p 375,056 Kernel32.dll (x86) 11/18/1999 06:17p 589,584 Kernel32.dll (Alpha) STATUS ====== Microsoft has confirmed this to be a problem in Windows NT 4.0. MORE INFORMATION ================ For additional information about a fix for non-Terminal Server Edition versions of Windows NT, click the article number below to view the article in the Microsoft Knowledge Base: Q246691 The CreateRemoteThread API May Leak a Handle Additional query words: ====================================================================== Keywords : kbenv kbtool kbWinNT400PreSP7Fix Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbNTTermServ400sp6 kbNTTermServSearch Version : :4.0 SP6 Hardware : ALPHA x86 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.