Windows-Binary-Interop fails with "Invalid argument" under certain circumstances

Windows Version

Microsoft Windows [Version 10.0.22631.5624]

WSL Version

2.5.10.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

6.6.87.2-1

Distro Version

Ubuntu 24.04.2 LTS (Noble Numbat)

Other Software

No response

Repro Steps

Steps to reproduce:

• Import a new Installation of Ubuntu using wsl --install Ubuntu and walk through OOBE (create a user).
• After Setup is complete, switch to root using sudo -i.
• Run /mnt/c/Windows/System32/wsl.exe --version, it should output version info
• Create /root/.cache directory and switch to it
• Run /mnt/c/Windows/System32/wsl.exe --version again, it should still work.
• Modify /etc/wsl.conf (adding interop options): I am still not sure, what exactly causes this, but according to the documentation, the following should have no changing effect (but it will anyway):

[interop]
enabled=true
appendWindowsPath=true

• Exit the distribution and terminate it (wsl --terminate Ubuntu)
• Start it again wsl -d Ubuntu and switch to root
• Try running /mnt/c/Windows/System32/wsl.exe --version in /root, it should still work
• Switch to /root/.cache and run /mnt/c/Windows/System32/wsl.exe --version again. Now you should receive:

root@FAVF-5CD4468BBT:~/.cache# /mnt/c/Windows/System32/wsl.exe --version
/mnt/c/Windows/System32/wsl.exe: Invalid argument
                                                 root@FAVF-5CD4468BBT:~/.cache#

Note: We sporadically got errors like these about 1,5 years ago (mostly in systemd services) and only now I have a valid way of reproducing them. So the error persists for quite a while in WSL.

Expected Behavior

The expected behaviour is, that no matter where I execute Windows binaries, they work or I receive a meaningful error on why it does not work.

Actual Behavior

The Windows binary just returns with Invalid argument and exits.

Diagnostic Logs

No response

Start by reproducing the failure through /mnt/c/Windows/System32/wsl.exe --version after enabling [interop] in /etc/wsl.conf, comparing /root with /root/.cache. Trace the Windows-binary interop entry point involved in the Invalid argument result; done means the command works from both directories or reports a meaningful error.