From ba7ad73e928de9972398def61c5758c42b23aec2 Mon Sep 17 00:00:00 2001
From: JosJuice <josjuice@gmail.com>
Date: Fri, 7 May 2021 18:19:42 +0200
Subject: [PATCH] NetPlay: Check that memory card region is valid

---
 Source/Core/Core/NetPlayClient.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Source/Core/Core/NetPlayClient.cpp b/Source/Core/Core/NetPlayClient.cpp
index c82cb891d8..f073e70f17 100644
--- a/Source/Core/Core/NetPlayClient.cpp
+++ b/Source/Core/Core/NetPlayClient.cpp
@@ -859,6 +859,13 @@ unsigned int NetPlayClient::OnData(sf::Packet& packet)
       bool mc251;
       packet >> is_slot_a >> region >> mc251;
 
+      // This check is mainly intended to filter out characters which have special meanings in paths
+      if (region != JAP_DIR && region != USA_DIR && region != EUR_DIR)
+      {
+        SyncSaveDataResponse(false);
+        return 0;
+      }
+
       const std::string path = File::GetUserPath(D_GCUSER_IDX) + GC_MEMCARD_NETPLAY +
                                (is_slot_a ? "A." : "B.") + region + (mc251 ? ".251" : "") + ".raw";
       if (File::Exists(path) && !File::Delete(path))