NTSTATUS TCOpenFsVolume (PEXTENSION Extension, PHANDLE volumeHandle, PFILE_OBJECT * fileObject)
{
	NTSTATUS ntStatus;
	OBJECT_ATTRIBUTES objectAttributes;
	UNICODE_STRING fullFileName;
	IO_STATUS_BLOCK ioStatus;
	WCHAR volumeName[TC_MAX_PATH];

	TCGetNTNameFromNumber (volumeName, sizeof(volumeName),Extension->nDosDriveNo);
	RtlInitUnicodeString (&fullFileName, volumeName);
	InitializeObjectAttributes (&objectAttributes, &fullFileName, OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE, NULL, NULL);

	ntStatus = ZwCreateFile (volumeHandle,
		SYNCHRONIZE | GENERIC_READ,
		&objectAttributes,
		&ioStatus,
		NULL,
		FILE_ATTRIBUTE_NORMAL,
		FILE_SHARE_READ | FILE_SHARE_WRITE,
		FILE_OPEN,
		FILE_SYNCHRONOUS_IO_NONALERT,
		NULL,
		0);

	Dump ("Volume %ls open NTSTATUS 0x%08x\n", volumeName, ntStatus);

	if (!NT_SUCCESS (ntStatus))
		return ntStatus;

	ntStatus = ObReferenceObjectByHandle (*volumeHandle,
		FILE_READ_DATA,
		NULL,
		KernelMode,
		fileObject,
		NULL);

	if (!NT_SUCCESS (ntStatus))
		ZwClose (*volumeHandle);

	return ntStatus;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.