From 29e577d966ae48810507c7a016ff1489a5843b2c Mon Sep 17 00:00:00 2001
From: agalq13 <71724834+agalq13@users.noreply.github.com>
Date: Thu, 11 Jun 2026 12:35:30 +0300
Subject: [PATCH] NetPlay: Validate controller packet indices

---
 Source/Core/Core/NetPlayServer.cpp | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/Source/Core/Core/NetPlayServer.cpp b/Source/Core/Core/NetPlayServer.cpp
index d26cc399c1..f37bc4200c 100644
--- a/Source/Core/Core/NetPlayServer.cpp
+++ b/Source/Core/Core/NetPlayServer.cpp
@@ -192,6 +192,12 @@ static void ClearPeerPlayerId(ENetPeer* peer)
   }
 }
 
+template <typename T>
+static bool IsValidPadIndex(const T& map_array, PadIndex index)
+{
+  return index >= 0 && static_cast<size_t>(index) < map_array.size();
+}
+
 void NetPlayServer::SetupIndex()
 {
   if (!Config::Get(Config::NETPLAY_USE_INDEX) || Config::Get(Config::NETPLAY_INDEX_NAME).empty() ||
@@ -814,7 +820,7 @@ unsigned int NetPlayServer::OnData(sf::Packet& packet, Client& player)
 
       // If the data is not from the correct player,
       // then disconnect them.
-      if (m_pad_map.at(map) != player.pid)
+      if (!IsValidPadIndex(m_pad_map, map) || m_pad_map.at(map) != player.pid)
       {
         return 1;
       }
@@ -862,6 +868,9 @@ unsigned int NetPlayServer::OnData(sf::Packet& packet, Client& player)
       PadIndex map;
       packet >> map;
 
+      if (!IsValidPadIndex(m_pad_map, map))
+        return 1;
+
       GCPadStatus pad;
       packet >> pad.button;
       spac << map << pad.button;
@@ -895,7 +904,7 @@ unsigned int NetPlayServer::OnData(sf::Packet& packet, Client& player)
 
       // If the data is not from the correct player,
       // then disconnect them.
-      if (m_wiimote_map.at(map) != player.pid)
+      if (!IsValidPadIndex(m_wiimote_map, map) || m_wiimote_map.at(map) != player.pid)
       {
         return 1;
       }