peass-ng/PEASS-ng · warning · ArgumentNullException

volumeMountPoint

Error message

volumeMountPoint

What it means

SetVolumeMountPoint(string volumeMountPoint, string volumeGuid) throws ArgumentNullException with paramName "volumeMountPoint" when the first argument is null, empty, or whitespace. This API creates a mounted-drive link at the given mount point and validates both arguments before any native call.

Source

Thrown at winPEAS/winPEASexe/winPEAS/3rdParty/AlphaFS/Device/Volume/Volume.SetVolumeMountPoint.cs:45

namespace Alphaleonis.Win32.Filesystem
{
   public static partial class Volume
   {
      /// <summary>[AlphaFS] Associates a volume with a Drive letter or a directory on another volume.</summary>
      /// <exception cref="ArgumentException"/>
      /// <exception cref="ArgumentNullException"/>
      /// <param name="volumeMountPoint">
      ///   The user-mode path to be associated with the volume. This may be a Drive letter (for example, "X:\")
      ///   or a directory on another volume (for example, "Y:\MountX\").
      /// </param>
      /// <param name="volumeGuid">A <see cref="string"/> containing the volume <see cref="Guid"/>.</param>      
      [SuppressMessage("Microsoft.Design", "CA1062:Validate arguments of public methods", MessageId = "1", Justification = "Utils.IsNullOrWhiteSpace validates arguments.")]
      [SecurityCritical]
      public static void SetVolumeMountPoint(string volumeMountPoint, string volumeGuid)
      {
         if (Utils.IsNullOrWhiteSpace(volumeMountPoint))
            throw new ArgumentNullException("volumeMountPoint");

         if (Utils.IsNullOrWhiteSpace(volumeGuid))
            throw new ArgumentNullException("volumeGuid");

         if (!volumeGuid.StartsWith(Path.VolumePrefix + "{", StringComparison.OrdinalIgnoreCase))
            throw new ArgumentException(Resources.Not_A_Valid_Guid, "volumeGuid");


         volumeMountPoint = Path.GetFullPathCore(null, false, volumeMountPoint, GetFullPathOptions.AsLongPath | GetFullPathOptions.AddTrailingDirectorySeparator | GetFullPathOptions.FullCheck);


         // This string must be of the form "\\?\Volume{GUID}\"
         volumeGuid = Path.AddTrailingDirectorySeparator(volumeGuid, false);


         // ChangeErrorMode is for the Win32 SetThreadErrorMode() method, used to suppress possible pop-ups.
         using (new NativeMethods.ChangeErrorMode(NativeMethods.ErrorMode.FailCriticalErrors))
         {

View on GitHub (pinned to 53fb989abc)

Solutions

1. Pass an existing NTFS directory path (e.g. "C:\Mount\Data") as volumeMountPoint
2. Validate both arguments with string.IsNullOrWhiteSpace before calling
3. Catch ArgumentNullException to report a configuration error to the user

Example fix

// before
Volume.SetVolumeMountPoint(mountDir, guid);
// after
if (string.IsNullOrWhiteSpace(mountDir)) throw new InvalidOperationException("Mount dir not configured");
Volume.SetVolumeMountPoint(mountDir, guid);

if (string.IsNullOrWhiteSpace(volumeMountPoint))
    throw new InvalidOperationException("volumeMountPoint must be an existing NTFS directory path.");

static bool CanMountAt(string dir) => !string.IsNullOrWhiteSpace(dir) && Directory.Exists(dir);

try { Volume.SetVolumeMountPoint(mountDir, guid); }
catch (ArgumentNullException ex) { Log.Error($"Mount failed, missing argument: {ex.ParamName}"); }

When it happens

Trigger: Calling Volume.SetVolumeMountPoint(null, guid) or passing ""/" " as the mount point directory while the GUID argument is valid.

Common situations: Scripted mount-point creation where the target folder variable was never set; config-driven mounting with a missing mount-path entry.

Related errors

• volumeGuid
• volumeGuid
• volumePathName
• volumeMountPoint
• path

AI-assisted analysis of peass-ng/PEASS-ng@53fb989abc (2026-09-02). Data as JSON: /api/errors/386103de588002aa. Report an issue: GitHub.