This is an old issue, but apparently still active. But I don't think it is an issue with the SerialPort modules at all.

I started getting "Win32::API:Call: parameter X had a buffer overflow" errors in a large project that has been alive for years. It was quite easy to see what had changed recently: I had started using Encode::decode() to read UTF-8-encoded strings.

It looks to me that the problem is with Win32::API. It cannot handle UTF-8 strings properly. I have filed a bug here.

This could easily be the same problem. On linux side, it would then be a completely different bug, but still likely caused by the same utf-8 confusion.