Add a guard to prevent a buffer overflow when saving a game (#6647)

changelog/snippets/fix.6647.md

@@ -0,0 +1 @@
+- (#6647) Fix a buffer overflow exploit in the `InternalSaveGame` user global

lua/ui/globals/InternalSaveGame.lua

@@ -0,0 +1,43 @@
+---@declare-global
+
+--******************************************************************************************************
+--** Copyright (c) 2024 Willem 'Jip' Wijnia
+--**
+--** Permission is hereby granted, free of charge, to any person obtaining a copy
+--** of this software and associated documentation files (the "Software"), to deal
+--** in the Software without restriction, including without limitation the rights
+--** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+--** copies of the Software, and to permit persons to whom the Software is
+--** furnished to do so, subject to the following conditions:
+--**
+--** The above copyright notice and this permission notice shall be included in all
+--** copies or substantial portions of the Software.
+--**
+--** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+--** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+--** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+--** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+--** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+--** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+--** SOFTWARE.
+--******************************************************************************************************
+
+do
+    local DebugAllocatedSize = debug.allocatedsize
+    local oldInternalSaveGame = _G.InternalSaveGame
+
+    --- Hook to fix a buffer overflow security issue in the engine
+    ---@param filename string
+    _G.InternalSaveGame = function(filename, friendlyFilename, onCompletionCallback)
+        local characterLimit = 100
+        if DebugAllocatedSize(filename) > characterLimit then
+            filename = filename:sub(1, characterLimit)
+        end
+
+        if DebugAllocatedSize(friendlyFilename) > characterLimit then
+            friendlyFilename = friendlyFilename:sub(1, characterLimit)
+        end
+
+        return oldInternalSaveGame(filename, friendlyFilename, onCompletionCallback)
+    end
+end

lua/userInit.lua

@@ -18,6 +18,7 @@ end
 -- # Global (and shared) init
 doscript '/lua/globalInit.lua'
 doscript '/lua/ui/globals/GpgNetSend.lua'
+doscript '/lua/ui/globals/InternalSaveGame.lua'
 
 -- Do we have an custom language set inside user-options ?
 local selectedlanguage = import("/lua/user/prefs.lua").GetFromCurrentProfile('options').selectedlanguage