From fb5f191b36181f3a7700fcab26214beff0288ce1 Mon Sep 17 00:00:00 2001
From: HetCreep <zxc59217412@gmail.com>
Date: Sun, 21 Jun 2026 17:13:51 +0700
Subject: [PATCH] Enumerate a config snapshot under the lock (#1357)

ConfigFile documents its public methods as thread-safe, but GetEnumerator
returned the live Dictionary enumerator with no lock, so a concurrent
Bind/Reload could invalidate it mid-foreach. Snapshot under _ioLock instead.
---
 BepInEx.Core/Configuration/ConfigFile.cs | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/BepInEx.Core/Configuration/ConfigFile.cs b/BepInEx.Core/Configuration/ConfigFile.cs
index 8f67ef7..dfa756b 100644
--- a/BepInEx.Core/Configuration/ConfigFile.cs
+++ b/BepInEx.Core/Configuration/ConfigFile.cs
@@ -92,9 +92,12 @@ public class ConfigFile : IDictionary<ConfigDefinition, ConfigEntryBase>
     public ConfigEntryBase this[string section, string key] => this[new ConfigDefinition(section, key)];
 
     /// <inheritdoc />
-    public IEnumerator<KeyValuePair<ConfigDefinition, ConfigEntryBase>> GetEnumerator() =>
-        // We can't really do a read lock for this
-        Entries.GetEnumerator();
+    public IEnumerator<KeyValuePair<ConfigDefinition, ConfigEntryBase>> GetEnumerator()
+    {
+        // Enumerate a snapshot taken under the lock so a concurrent mutation cannot invalidate the iterator.
+        lock (_ioLock)
+            return Entries.ToList().GetEnumerator();
+    }
 
     IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();