FileStream.ReadAsync() with isAsync: true is throwing IOException

[X9VoiD]

Description

FileStreams opened with isAsync: true fails to perform asynchronous read operations. Not specifying isAsync: true runs completely fine.

The function used to get a FileStream:

private void InitializeFileStream(string filePath, bool exclusive, int readSize, int writeSize)
{
    FileAccess access = 0;
    if (readSize > 0)
        access |= FileAccess.Read;
    if (writeSize > 0)
        access |= FileAccess.Write;

    FileShare share = exclusive ? FileShare.None : (FileShare)access;
    FileStream = new FileStream(filePath, FileMode.Open, access, share, Math.Max(readSize, writeSize), true);
}

Run loop of the task:

private async void ReadPoll()
{
    while (_run)
    {
        int bytesReturned = await FileStream!.ReadAsync(_readBuffer);
        OnInput(_readBuffer.Slice(0, bytesReturned));
    }
}

Configuration

OS Version	Windows 10 21H1
.NET Version	.NET 6 preview 4

Regression?

I'm not sure...

Other information

Exception has occurred: CLR/System.IO.IOException
An exception of type 'System.IO.IOException' occurred in System.Private.CoreLib.dll but was not handled in user code: 'Incorrect function. : '\\?\hid#vid_28bd&pid_0906&mi_02#7&194ad48b&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}''
   at System.IO.Strategies.FileStreamHelpers.GetFileLength(SafeFileHandle handle, String path)
   at System.IO.Strategies.WindowsFileStreamStrategy.get_Length()
   at System.IO.Strategies.AsyncWindowsFileStreamStrategy.ReadAsyncInternal(Memory`1 destination, CancellationToken cancellationToken)
   at System.IO.Strategies.AsyncWindowsFileStreamStrategy.ReadAsync(Memory`1 destination, CancellationToken cancellationToken)
   at System.IO.Strategies.BufferedFileStreamStrategy.ReadAsync(Memory`1 buffer, CancellationToken cancellationToken)
   at System.IO.FileStream.ReadAsync(Memory`1 buffer, CancellationToken cancellationToken)

The source repo is currently private, but if more information or testing is needed from my side then I'll do it willingly.

Tagging subscribers to this area: @dotnet/area-system-io
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

FileStreams opened with isAsync: true fails to perform asynchronous read operations. Not specifying isAsync: true runs completely fine.

The function used to get a FileStream:

private void InitializeFileStream(string filePath, bool exclusive, int readSize, int writeSize)
{
    FileAccess access = 0;
    if (readSize > 0)
        access |= FileAccess.Read;
    if (writeSize > 0)
        access |= FileAccess.Write;

    FileShare share = exclusive ? FileShare.None : (FileShare)access;
    FileStream = new FileStream(filePath, FileMode.Open, access, share, Math.Max(readSize, writeSize), true);
}

Run loop of the task:

private async Task ReadPoll()
{
    while (_run)
    {
        int bytesReturned = await FileStream!.ReadAsync(_readBuffer);
        OnInput(_readBuffer.Slice(0, bytesReturned));
    }
}

Configuration

OS Version	Windows 10 21H1
.NET Version	.NET 6 preview 4

Regression?

I'm not sure...

Other information

An unhandled exception of type 'System.IO.IOException' occurred in System.Private.CoreLib.dll: 'Incorrect function. : '\\?\hid#vid_28bd&pid_0906&mi_02#7&194ad48b&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}''
   at System.IO.Strategies.FileStreamHelpers.GetFileLength(SafeFileHandle handle, String path)
   at System.IO.Strategies.WindowsFileStreamStrategy.get_Length()
   at System.IO.Strategies.AsyncWindowsFileStreamStrategy.ReadAsyncInternal(Memory`1 destination, CancellationToken cancellationToken)
   at System.IO.Strategies.AsyncWindowsFileStreamStrategy.Read(Byte[] buffer, Int32 offset, Int32 count)
   at System.IO.Stream.Read(Span`1 buffer)
   at System.IO.Strategies.BufferedFileStreamStrategy.ReadSpan(Span`1 destination, ArraySegment`1 arraySegment)
   at System.IO.FileStream.Read(Span`1 buffer)

The source repo is currently private, but if more information or testing is needed from my side then I'll do it willingly.

Author:	X9VoiD
Assignees:	-
Labels:	area-System.IO, untriaged
Milestone:	-

[adamsitnik]

Hi @X9VoiD

Are you sure that you have provided the right example and stack trace?

In the source code I can see a call to ReadAsync

await FileStream!.ReadAsync(_readBuffer);

While in the stack trace I can see a call to Read (sync, not async):

System.IO.FileStream.Read(Span`1 buffer)

The method that should be invoked:

runtime/src/libraries/System.Private.CoreLib/src/System/IO/FileStream.cs

Line 358 in 8a9a24b

return _strategy.ReadAsync(buffer, cancellationToken);

[X9VoiD]

My bad, here's the correct stack trace:

Exception has occurred: CLR/System.IO.IOException
An exception of type 'System.IO.IOException' occurred in System.Private.CoreLib.dll but was not handled in user code: 'Incorrect function. : '\\?\hid#vid_28bd&pid_0906&mi_02#7&194ad48b&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}''
   at System.IO.Strategies.FileStreamHelpers.GetFileLength(SafeFileHandle handle, String path)
   at System.IO.Strategies.WindowsFileStreamStrategy.get_Length()
   at System.IO.Strategies.AsyncWindowsFileStreamStrategy.ReadAsyncInternal(Memory`1 destination, CancellationToken cancellationToken)
   at System.IO.Strategies.AsyncWindowsFileStreamStrategy.ReadAsync(Memory`1 destination, CancellationToken cancellationToken)
   at System.IO.Strategies.BufferedFileStreamStrategy.ReadAsync(Memory`1 buffer, CancellationToken cancellationToken)
   at System.IO.FileStream.ReadAsync(Memory`1 buffer, CancellationToken cancellationToken)

Also updated the stack trace in issue.

[adamsitnik]

@X9VoiD Could you please try to run your example with the following env var enabled:

set DOTNET_SYSTEM_IO_USENET5COMPATFILESTREAM=1

And see if it works?

Which Windows version are you using? Is the file a local file or a file located on a remote machine? What is the file system?

[X9VoiD]

I'm running Windows 10 21H1, the latest one, and the file is a local HID device found through SetupDi functions.

I've set the environment variable on either the cmd prompt or globally like this;

Then I rebuilt it just to be sure, but both still failed with this stack trace:

Exception has occurred: CLR/System.IO.IOException
An exception of type 'System.IO.IOException' occurred in System.Private.CoreLib.dll but was not handled in user code: 'Incorrect function. : '\\?\hid#vid_28bd&pid_0906&mi_02#7&194ad48b&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}''
   at System.IO.Strategies.FileStreamHelpers.GetFileLength(SafeFileHandle handle, String path)
   at System.IO.Strategies.WindowsFileStreamStrategy.get_Length()
   at System.IO.Strategies.AsyncWindowsFileStreamStrategy.ReadAsyncInternal(Memory`1 destination, CancellationToken cancellationToken)
   at System.IO.Strategies.AsyncWindowsFileStreamStrategy.ReadAsync(Memory`1 destination, CancellationToken cancellationToken)
   at System.IO.Strategies.BufferedFileStreamStrategy.ReadAsync(Memory`1 buffer, CancellationToken cancellationToken)
   at System.IO.FileStream.ReadAsync(Memory`1 buffer, CancellationToken cancellationToken)

[stephentoub]

but both still failed with this stack trace

If that's the exact stack trace you saw in both cases, then the environment variable didn't properly configure things. Can you share the exact stack trace you got with the environment variable set?

[stephentoub]

Regression? I'm not sure...

Does it work for you with .NET 5 or any other version of .NET besides .NET 6?

[adamsitnik]

@X9VoiD could you please run the following app by providing the path as first argument?

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
  </PropertyGroup>
</Project>

using Microsoft.Win32.SafeHandles;
using System;
using System.IO;
using System.Runtime.InteropServices;

namespace Issue54143
{
    class Program
    {
        static void Main(string[] args)
        {
            Test(args[0]);
            Test(Path.GetFullPath(args[0]));
        }

        private static unsafe void Test(string path)
        {
            Console.WriteLine($"Path: '{path}'");
            using (SafeFileHandle handle = CreateFile(path, FileAccess.Read, FileShare.Read, IntPtr.Zero, FileMode.Open, (int)FileOptions.Asynchronous, IntPtr.Zero))
            {
                Console.WriteLine($"IsInvalid: {handle.IsInvalid}");
                Console.WriteLine($"GetFileType(): {GetFileType(handle)}");

                FILE_STANDARD_INFO info;
                if (!GetFileInformationByHandleEx(handle, 1 /* FILE_STANDARD_INFO */, &info, (uint)sizeof(FILE_STANDARD_INFO)))
                {
                    Console.WriteLine($"Marshal.GetLastWin32Error(): {Marshal.GetLastWin32Error()}");
                }
                else
                {
                    Console.WriteLine($"EndOfFile: {info.EndOfFile}");
                }
            }
        }

        [DllImport("kernel32.dll", EntryPoint = "CreateFileW", SetLastError = true, CharSet = CharSet.Unicode, BestFitMapping = false, ExactSpelling = true)]
        private static extern unsafe SafeFileHandle CreateFile(
             string lpFileName,
             FileAccess dwDesiredAccess,
             FileShare dwShareMode,
             IntPtr lpSecurityAttributes,
             FileMode dwCreationDisposition,
             int dwFlagsAndAttributes,
             IntPtr hTemplateFile);

        [DllImport("kernel32.dll", SetLastError = true)]
        internal static extern int GetFileType(SafeHandle handle);

        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
        internal static extern unsafe bool GetFileInformationByHandleEx(SafeFileHandle hFile, int FileInformationClass, void* lpFileInformation, uint dwBufferSize);

        internal enum BOOL : int
        {
            FALSE = 0,
            TRUE = 1,
        }

        internal struct FILE_STANDARD_INFO
        {
            internal long AllocationSize;
            internal long EndOfFile;
            internal uint NumberOfLinks;
            internal BOOL DeletePending;
            internal BOOL Directory;
        }
    }
}

dotnet run -- "thePathGoesHere"

[X9VoiD]

dotnet run -- "\\?\hid#vid_28bd&pid_0906&mi_02#7&194ad48b&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}"

Path: '\\?\hid#vid_28bd&pid_0906&mi_02#7&194ad48b&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}'
IsInvalid: False
GetFileType(): 0
Marshal.GetLastWin32Error(): 1
Path: '\\?\hid#vid_28bd&pid_0906&mi_02#7&194ad48b&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}'
IsInvalid: False
GetFileType(): 0
Marshal.GetLastWin32Error(): 1

[adamsitnik]

@X9VoiD big thanks for providing all the information. Looking at the results you have provided we have most probably never supported this scenario (GetFileType() returns 0 which means UNKNOWN file type) but I think that we should be able to get it working by recognizing such files as non-seekable files. The problem is that I can't repro the problem locally...

Is there any chance that you could tell me which sys-calls do you use exactly to get such a path? Or help me to create a repro? This is what I got so far:

using System;
using System.Runtime.InteropServices;
using System.Text;

namespace DeviceIds
{
    class Program
    {
        static void Main(string[] args)
        {
            const int DIGCF_PRESENT = 0x2;
            const int DIGCF_ALLCLASSES = 0x4;

            IntPtr deviceInfoSet = SetupDiGetClassDevs(IntPtr.Zero, "HID", IntPtr.Zero, DIGCF_ALLCLASSES | DIGCF_PRESENT);

            try
            {
                SP_DEVINFO_DATA deviceInfoData = new SP_DEVINFO_DATA();
                deviceInfoData.cbSize = (uint)Marshal.SizeOf(deviceInfoData);

                int deviceIndex = 0;
                while (SetupDiEnumDeviceInfo(deviceInfoSet, deviceIndex++, ref deviceInfoData))
                {
                    StringBuilder deviceInstanceId = new StringBuilder(1024);
                    if (SetupDiGetDeviceInstanceId(deviceInfoSet, ref deviceInfoData, deviceInstanceId, deviceInstanceId.Capacity, out int requiredSize))
                    {
                        Console.WriteLine(deviceInstanceId.ToString());
                    }
                }
            }
            finally
            {
                SetupDiDestroyDeviceInfoList(deviceInfoSet);
            }
        }

        [StructLayout(LayoutKind.Sequential)]
        struct SP_DEVICE_INTERFACE_DATA
        {
            public int cbSize;
            public Guid interfaceClassGuid;
            public int flags;
            private UIntPtr reserved;
        }

        [StructLayout(LayoutKind.Sequential)]
        internal struct SP_DEVINFO_DATA
        {
            public uint cbSize;
            public Guid ClassGuid;
            public uint DevInst;
            public IntPtr Reserved;
        }

        [DllImport("setupapi.dll", CharSet = CharSet.Auto)]
        static extern IntPtr SetupDiGetClassDevs(IntPtr ClassGuid, [MarshalAs(UnmanagedType.LPTStr)] string Enumerator, IntPtr hwndParent, int Flags);

        [DllImport("setupapi.dll", SetLastError = true)]
        public static extern bool SetupDiDestroyDeviceInfoList(IntPtr DeviceInfoSet);

        [DllImport("setupapi.dll", SetLastError = true)]
        internal static extern bool SetupDiEnumDeviceInfo(IntPtr DeviceInfoSet, int MemberIndex, ref SP_DEVINFO_DATA DeviceInfoData);

        [DllImport("setupapi.dll", SetLastError = true, CharSet = CharSet.Auto)]
        static extern bool SetupDiGetDeviceInstanceId(IntPtr DeviceInfoSet, ref SP_DEVINFO_DATA DeviceInfoData, StringBuilder DeviceInstanceId, int DeviceInstanceIdSize, out int RequiredSize);
    }
}

Which gives me a list of device IDs:

HID\VID_0B0E&PID_24C8&MI_03&COL04\B&92AE56&0&0003
HID\VID_0B0E&PID_24C8&MI_03&COL01\B&92AE56&0&0000
HID\VID_045E&PID_07A5&MI_02&COL03\A&EF954E6&0&0002
HID\VID_045E&PID_07A5&MI_02&COL02\A&EF954E6&0&0001
HID\VID_045E&PID_07A5&MI_02&COL01\A&EF954E6&0&0000
HID\VID_0B0E&PID_24C8&MI_03&COL02\B&92AE56&0&0001
HID\VID_045E&PID_07A5&MI_00\A&1B0D0663&0&0000
HID\VID_0424&PID_274C\8&12BBBD2C&0&0000
HID\VID_045E&PID_07A5&MI_01&COL01\A&32D092A8&0&0000
HID\VID_0B0E&PID_24C8&MI_03&COL03\B&92AE56&0&0002
HID\VID_045E&PID_07A5&MI_01&COL02\A&32D092A8&0&0001

But I don't know how to get a path to a file like yours.

[X9VoiD]

using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Text;

namespace DeviceIds
{
    class Program
    {
        static void Main(string[] args)
        {
            const int DIGCF_PRESENT = 0x2;
            const int DIGCF_DEVICEINTERFACE = 0x10;
            const int ERROR_NO_MORE_ITEMS = 259;
            HidD_GetHidGuid(out Guid HidGuid);

            IntPtr deviceInfoSet = SetupDiGetClassDevs(in HidGuid, IntPtr.Zero, IntPtr.Zero, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);

            try
            {
                SP_DEVINFO_DATA deviceInfoData = new SP_DEVINFO_DATA();
                deviceInfoData.cbSize = (uint)Marshal.SizeOf(deviceInfoData);

                uint deviceIndex = 0;
                while (SetupDiEnumDeviceInfo(deviceInfoSet, deviceIndex++, ref deviceInfoData))
                {
                    if (Marshal.GetLastWin32Error() == ERROR_NO_MORE_ITEMS)
                        break;

                    SP_DEVICE_INTERFACE_DATA deviceInterfaceData = new SP_DEVICE_INTERFACE_DATA();
                    deviceInterfaceData.cbSize = Marshal.SizeOf(deviceInterfaceData);

                    if (!SetupDiEnumDeviceInterfaces(deviceInfoSet, IntPtr.Zero, in HidGuid, deviceIndex, ref deviceInterfaceData))
                    {
                        // throw new Win32Exception("Failed to get device interface data");
                    }

                    SP_DEVICE_INTERFACE_DETAIL_DATA deviceInterfaceDetailData = new SP_DEVICE_INTERFACE_DETAIL_DATA();
                    deviceInterfaceDetailData.cbSize = IntPtr.Size == 8 ? 8 : 6;

                    uint size = (uint)Marshal.SizeOf(deviceInterfaceDetailData);

                    if (!SetupDiGetDeviceInterfaceDetail(deviceInfoSet, ref deviceInterfaceData, ref deviceInterfaceDetailData, size, ref size, IntPtr.Zero))
                    {
                        // throw new Exception("Failed to get device interface detail");
                    }

                    Console.WriteLine(deviceInterfaceDetailData.DevicePath);
                }
            }
            finally
            {
                SetupDiDestroyDeviceInfoList(deviceInfoSet);
            }
        }

        [StructLayout(LayoutKind.Sequential)]
        struct SP_DEVICE_INTERFACE_DATA
        {
            public int cbSize;
            public Guid interfaceClassGuid;
            public int flags;
            private UIntPtr reserved;
        }

        [StructLayout(LayoutKind.Sequential)]
        struct SP_DEVINFO_DATA
        {
            public uint cbSize;
            public Guid ClassGuid;
            public uint DevInst;
            public IntPtr Reserved;
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        struct SP_DEVICE_INTERFACE_DETAIL_DATA
        {
            public int cbSize;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 256)]
            public string DevicePath;
        }

        [DllImport("setupapi.dll", CharSet = CharSet.Auto)]
        static extern IntPtr SetupDiGetClassDevs(IntPtr ClassGuid, [MarshalAs(UnmanagedType.LPTStr)] string Enumerator, IntPtr hwndParent, int Flags);

        [DllImport("setupapi.dll", CharSet = CharSet.Auto)]
        static extern IntPtr SetupDiGetClassDevs(in Guid ClassGuid, IntPtr Enumerator, IntPtr hwndParent, int Flags);

        [DllImport("setupapi.dll", SetLastError = true)]
        static extern bool SetupDiDestroyDeviceInfoList(IntPtr DeviceInfoSet);

        [DllImport("setupapi.dll", SetLastError = true)]
        static extern bool SetupDiEnumDeviceInfo(IntPtr DeviceInfoSet, uint MemberIndex, ref SP_DEVINFO_DATA DeviceInfoData);

        [DllImport("setupapi.dll", SetLastError = true, CharSet = CharSet.Auto)]
        static extern bool SetupDiGetDeviceInstanceId(IntPtr DeviceInfoSet, ref SP_DEVINFO_DATA DeviceInfoData, StringBuilder DeviceInstanceId, int DeviceInstanceIdSize, out int RequiredSize);

        [DllImport("setupapi.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        static extern bool SetupDiEnumDeviceInterfaces(IntPtr hDevInfo, IntPtr devInfo, in Guid interfaceClassGuid, uint memberIndex, ref SP_DEVICE_INTERFACE_DATA deviceInterfaceData);

        [DllImport("setupapi.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        static extern bool SetupDiGetDeviceInterfaceDetail(IntPtr hDevInfo, ref SP_DEVICE_INTERFACE_DATA deviceInterfaceData, ref SP_DEVICE_INTERFACE_DETAIL_DATA deviceInterfaceDetailData, uint deviceInterfaceDetailDataSize, ref uint requiredSize, IntPtr deviceInfoData);

        [DllImport("hid.dll", SetLastError = true)]
        static extern void HidD_GetHidGuid(out Guid Guid);
    }
}

This gives me:

\\?\hid#vid_1ea7&pid_0907&mi_00#7&5b581ed&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}\kbd
\\?\hid#hid&col05#1&2d595ca7&0&0004#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_1ea7&pid_0907&mi_02&col04#7&65e2f90&0&0003#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#{3c316a9d-e0f1-4138-9ae1-72ab823e022f}&col03#1&ec462fd&0&0002#{4d1e55b2-f16f-11cf-88cb-001111000030}\kbd
\\?\hid#vid_28bd&pid_0906&mi_00&col03#7&255e8608&1&0002#{4d1e55b2-f16f-11cf-88cb-001111000030}\kbd
\\?\hid#vid_046d&pid_c084&mi_01&col02#8&39e92dbc&0&0001#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_046d&pid_c084&mi_01&col03#8&39e92dbc&0&0002#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_046d&pid_c084&mi_01&col04#8&39e92dbc&0&0003#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_28bd&pid_0906&mi_00&col01#7&255e8608&1&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_1ea7&pid_0907&mi_02&col03#7&65e2f90&0&0002#{4d1e55b2-f16f-11cf-88cb-001111000030}\kbd
\\?\hid#vid_046d&pid_c084&mi_00#8&2225a177&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_046d&pid_c084&mi_01&col05#8&39e92dbc&0&0004#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_28bd&pid_0906&mi_00&col02#7&255e8608&1&0001#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_1ea7&pid_0907&mi_01#7&1e21bbd5&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_046d&pid_c084&mi_01&col01#8&39e92dbc&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}\kbd
\\?\hid#{3c316a9d-e0f1-4138-9ae1-72ab823e022f}&col01#1&ec462fd&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_1ea7&pid_0907&mi_02&col01#7&65e2f90&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#{3c316a9d-e0f1-4138-9ae1-72ab823e022f}&col02#1&ec462fd&0&0001#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_1ea7&pid_0907&mi_02&col02#7&65e2f90&0&0001#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#hpq6001#3&3229b8bb&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#hid&col01#1&2d595ca7&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#vid_28bd&pid_0906&mi_02#7&194ad48b&1&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#hid&col02#1&2d595ca7&0&0001#{4d1e55b2-f16f-11cf-88cb-001111000030}
\\?\hid#hid&col03#1&2d595ca7&0&0002#{4d1e55b2-f16f-11cf-88cb-001111000030}

Which should be a valid path. Some of these file paths though are exclusively opened by Windows, for example, all of the paths ending in \kbd