Issue #20096 has been updated by kjtsanaktsidis (KJ Tsanaktsidis). Thank you for your report. Your diagnosis looks right, this probably is a memory overread. Your patch looks reasonable - are you able to open this as a Github pull request? Also, are you familiar with `REG_MULTI_SZ`? To my quick glance, that looks like it should also not need the `termsize` value (it's already appending `WCHAR_NUL` like your patch is). Do you think that should be removed too? ---------------------------------------- Bug #20096: Ruby 3.2.2 win32/registry: Junk appended to Windows Registry String Value https://bugs.ruby-lang.org/issues/20096#change-105901 * Author: jay4rubydev (Jay M) * Status: Open * Priority: Normal * ruby -v: ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x64-mswin64_140] * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Ruby Version: ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x64-mswin64_140] Compiler: MSVC 2019 - Microsoft (R) C/C++ Optimizing Compiler Version 19.29.30147 for x64. Issue: win32/registry adds junk to Windows Registry String Value Code: require 'win32/registry' win_oracle_key = "SOFTWARE\\MicroSoft" reg=Win32::Registry::HKEY_LOCAL_MACHINE.open(win_oracle_key, Win32::Registry::KEY_ALL_ACCESS) inst_loc_key = "inst_loc" inv_dir="C:\\Program Files\\Tester\\ModuleInfo" reg[inst_loc_key] = inv_dir Result: Registry contains: C:\Program Files\Tester\ModuleInfo爀 Observation: Looks like memory overread Expected Result - without the junk: C:\Program Files\Tester\ModuleInfo After changing the code in registry.rb: From: def write(name, type, data) termsize = 0 case type when REG_SZ, REG_EXPAND_SZ data = data.encode(WCHAR) termsize = WCHAR_SIZE To: def write(name, type, data) termsize = 0 case type when REG_SZ, REG_EXPAND_SZ enc_data = data.encode(WCHAR) # Add NULL WCHAR for string data and don't set the termsize because # enc_data.bytesize will now include the size of the NULL character. enc_data += WCHAR_NUL # termsize = WCHAR_SIZE ... -- https://bugs.ruby-lang.org/