Overflow from NtGdiAddFontResourceW Returning Uninitialized Pool

ID: Q240740

The information in this article applies to:

Microsoft Windows NT Server version 4.0
Microsoft Windows NT Workstation version 4.0
Microsoft Windows NT Server, Enterprise Edition version 4.0

SYMPTOMS

When the NtGdiAddFontResourceW() function call is started on your computer running Windows NT 4.0, the calling process may stop responding (hang) and an overflow error message may be returned to the user.

CAUSE

This behavior occurs because the string length needs to be limited to a smaller value.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

The length of pwszFile has been changed to accommodate this requirement and to enable the processing of this routine without overflow.

STATUS

Microsoft has confirmed this to be a problem in Windows NT 4.0. This problem was first corrected in Windows NT 4.0 Service Pack 6.

MORE INFORMATION

When the NtGdiAddFontResourceW() function is started, a WCHAR pointer is passed from usermode. The routine then allocates a buffer and forwards the process to bCheckAndCapThePath(). The bCheckAndCapThePath() function calls cCapString() to copy and uppercase the string, and cCapString() uses RtlUpcaseUnicodeString() to copy and uppercase the strings if it has the correct word buffer size. If the string length is greater than 32,767 bytes, the routine cannot start all of the output buffer and some of the pool may be returned as 'not started' and cause an overflow.

Additional query words: win32 subsystem

Keywords : kbprg ntsp kbbug4.00 kbfix4.00 NT4SP6Fix
Version : winnt:4.0
Platform : winnt
Issue type : kbbug