fix(core): clear 5-minute timeouts in oauth flow to prevent memory leaks (#24968)

packages/core/src/code_assist/oauth2.ts

@@ -424,6 +424,7 @@ async function authWithUserCode(client: OAuth2Client): Promise<boolean> {
         '\n\n',
     );
 
+    let authTimeoutId: NodeJS.Timeout | undefined;
     const code = await new Promise<string>((resolve, reject) => {
       const rl = readline.createInterface({
         input: process.stdin,
@@ -431,20 +432,29 @@ async function authWithUserCode(client: OAuth2Client): Promise<boolean> {
         terminal: true,
       });
 
-      const timeout = setTimeout(() => {
-        rl.close();
-        reject(
+      const abortController = new AbortController();
+      authTimeoutId = setTimeout(() => {
+        abortController.abort(
           new FatalAuthenticationError(
             'Authorization timed out after 5 minutes.',
           ),
         );
       }, 300000); // 5 minute timeout
+      authTimeoutId.unref();
+
+      const onAbort = () => {
+        rl.close();
+        reject(abortController.signal.reason);
+      };
+      abortController.signal.addEventListener('abort', onAbort, { once: true });
 
       rl.question('Enter the authorization code: ', (code) => {
-        clearTimeout(timeout);
+        abortController.signal.removeEventListener('abort', onAbort);
         rl.close();
         resolve(code.trim());
       });
+    }).finally(() => {
+      if (authTimeoutId) clearTimeout(authTimeoutId);
     });
 
     if (!code) {

packages/core/src/mcp/oauth-provider.test.ts

@@ -1023,31 +1023,35 @@ describe('MCPOAuthProvider', () => {
     });
 
     it('should handle callback timeout', async () => {
-      vi.mocked(http.createServer).mockImplementation(
-        () => mockHttpServer as unknown as http.Server,
-      );
+      vi.useFakeTimers();
+      try {
+        vi.mocked(http.createServer).mockImplementation(
+          () => mockHttpServer as unknown as http.Server,
+        );
 
-      mockHttpServer.listen.mockImplementation((port, callback) => {
-        callback?.();
-        // Don't trigger callback - simulate timeout
-      });
+        mockHttpServer.listen.mockImplementation((port, callback) => {
+          callback?.();
+          // Don't trigger callback - simulate timeout
+        });
 
-      // Mock setTimeout to trigger timeout immediately
-      const originalSetTimeout = global.setTimeout;
-      global.setTimeout = vi.fn((callback, delay) => {
-        if (delay === 5 * 60 * 1000) {
-          // 5 minute timeout
-          callback();
-        }
-        return originalSetTimeout(callback, 0);
-      }) as unknown as typeof setTimeout;
+        const authProvider = new MCPOAuthProvider();
 
-      const authProvider = new MCPOAuthProvider();
-      await expect(
-        authProvider.authenticate('test-server', mockConfig),
-      ).rejects.toThrow('OAuth callback timeout');
+        const authPromise = authProvider
+          .authenticate('test-server', mockConfig)
+          .catch((e: Error) => {
+            if (e.message !== 'OAuth callback timeout') throw e;
+            return e;
+          });
 
-      global.setTimeout = originalSetTimeout;
+        // Advance timers by 5 minutes
+        await vi.advanceTimersByTimeAsync(5 * 60 * 1000);
+
+        const error = await authPromise;
+        expect(error).toBeInstanceOf(Error);
+        expect((error as Error).message).toBe('OAuth callback timeout');
+      } finally {
+        vi.useRealTimers();
+      }
     });
 
     it('should use port from redirectUri if provided', async () => {

packages/core/src/utils/oauth-flow.test.ts

@@ -305,6 +305,28 @@ describe('oauth-flow', () => {
         'Invalid value for OAUTH_CALLBACK_PORT',
       );
     });
+
+    it('should settle on timeout without keeping the process alive', async () => {
+      vi.useFakeTimers();
+      try {
+        const server = startCallbackServer('timeout-state');
+        await server.port;
+
+        const responsePromise = server.response.catch((e: Error) => {
+          if (e.message !== 'OAuth callback timeout') throw e;
+          return e;
+        });
+
+        // Advance timers by 5 minutes to trigger the timeout
+        await vi.advanceTimersByTimeAsync(5 * 60 * 1000);
+
+        const error = await responsePromise;
+        expect(error).toBeInstanceOf(Error);
+        expect((error as Error).message).toBe('OAuth callback timeout');
+      } finally {
+        vi.useRealTimers();
+      }
+    });
   });
 
   describe('exchangeCodeForToken', () => {

packages/core/src/utils/oauth-flow.ts

@@ -116,6 +116,8 @@ export function startCallbackServer(
     portReject = reject;
   });
 
+  let timeoutId: NodeJS.Timeout | undefined;
+
   const responsePromise = new Promise<OAuthAuthorizationResponse>(
     (resolve, reject) => {
       let serverPort: number;
@@ -221,18 +223,31 @@ export function startCallbackServer(
         portResolve(serverPort); // Resolve port promise immediately
       });
 
-      // Timeout after 5 minutes
-      setTimeout(
+      const abortController = new AbortController();
+      timeoutId = setTimeout(
         () => {
-          server.close();
-          reject(new Error('OAuth callback timeout'));
+          abortController.abort(new Error('OAuth callback timeout'));
         },
         5 * 60 * 1000,
       );
+      timeoutId.unref();
+
+      const onAbort = () => {
+        server.close();
+        reject(abortController.signal.reason);
+      };
+      abortController.signal.addEventListener('abort', onAbort, { once: true });
+
+      server.on('close', () => {
+        abortController.signal.removeEventListener('abort', onAbort);
+      });
     },
   );
 
-  return { port: portPromise, response: responsePromise };
+  return {
+    port: portPromise,
+    response: responsePromise,
+  };
 }
 
 /**