hardening: bound plugin loader cache

src/plugins/loader.test.ts

@@ -623,6 +623,47 @@ describe("loadOpenClawPlugins", () => {
     expect(third).toBe(second);
   });
 
+  it("evicts least recently used registries when the loader cache exceeds its cap", () => {
+    useNoBundledPlugins();
+    const plugin = writePlugin({
+      id: "cache-eviction",
+      filename: "cache-eviction.cjs",
+      body: `module.exports = { id: "cache-eviction", register() {} };`,
+    });
+    const stateDirs = Array.from({ length: __testing.maxPluginRegistryCacheEntries + 1 }, () =>
+      makeTempDir(),
+    );
+
+    const loadWithStateDir = (stateDir: string) =>
+      loadOpenClawPlugins({
+        env: {
+          ...process.env,
+          OPENCLAW_STATE_DIR: stateDir,
+          OPENCLAW_BUNDLED_PLUGINS_DIR: "/nonexistent/bundled/plugins",
+        },
+        config: {
+          plugins: {
+            allow: ["cache-eviction"],
+            load: {
+              paths: [plugin.file],
+            },
+          },
+        },
+      });
+
+    const first = loadWithStateDir(stateDirs[0] ?? makeTempDir());
+    const second = loadWithStateDir(stateDirs[1] ?? makeTempDir());
+
+    expect(loadWithStateDir(stateDirs[0] ?? makeTempDir())).toBe(first);
+
+    for (const stateDir of stateDirs.slice(2)) {
+      loadWithStateDir(stateDir);
+    }
+
+    expect(loadWithStateDir(stateDirs[0] ?? makeTempDir())).toBe(first);
+    expect(loadWithStateDir(stateDirs[1] ?? makeTempDir())).not.toBe(second);
+  });
+
   it("normalizes bundled plugin env overrides against the provided env", () => {
     const bundledDir = makeTempDir();
     const homeDir = path.dirname(bundledDir);

src/plugins/loader.ts

@@ -49,6 +49,7 @@ export type PluginLoadOptions = {
   mode?: "full" | "validate";
 };
 
+const MAX_PLUGIN_REGISTRY_CACHE_ENTRIES = 32;
 const registryCache = new Map<string, PluginRegistry>();
 
 export function clearPluginLoaderCache(): void {
@@ -171,8 +172,34 @@ export const __testing = {
   listPluginSdkExportedSubpaths,
   resolvePluginSdkAliasCandidateOrder,
   resolvePluginSdkAliasFile,
+  maxPluginRegistryCacheEntries: MAX_PLUGIN_REGISTRY_CACHE_ENTRIES,
 };
 
+function getCachedPluginRegistry(cacheKey: string): PluginRegistry | undefined {
+  const cached = registryCache.get(cacheKey);
+  if (!cached) {
+    return undefined;
+  }
+  // Refresh insertion order so frequently reused registries survive eviction.
+  registryCache.delete(cacheKey);
+  registryCache.set(cacheKey, cached);
+  return cached;
+}
+
+function setCachedPluginRegistry(cacheKey: string, registry: PluginRegistry): void {
+  if (registryCache.has(cacheKey)) {
+    registryCache.delete(cacheKey);
+  }
+  registryCache.set(cacheKey, registry);
+  while (registryCache.size > MAX_PLUGIN_REGISTRY_CACHE_ENTRIES) {
+    const oldestKey = registryCache.keys().next().value;
+    if (!oldestKey) {
+      break;
+    }
+    registryCache.delete(oldestKey);
+  }
+}
+
 function buildCacheKey(params: {
   workspaceDir?: string;
   plugins: NormalizedPluginsConfig;
@@ -503,7 +530,7 @@ export function loadOpenClawPlugins(options: PluginLoadOptions = {}): PluginRegi
   });
   const cacheEnabled = options.cache !== false;
   if (cacheEnabled) {
-    const cached = registryCache.get(cacheKey);
+    const cached = getCachedPluginRegistry(cacheKey);
     if (cached) {
       activatePluginRegistry(cached, cacheKey);
       return cached;
@@ -863,7 +890,7 @@ export function loadOpenClawPlugins(options: PluginLoadOptions = {}): PluginRegi
   });
 
   if (cacheEnabled) {
-    registryCache.set(cacheKey, registry);
+    setCachedPluginRegistry(cacheKey, registry);
   }
   activatePluginRegistry(registry, cacheKey);
   return registry;