fix: improve socket cleanup to prevent potential memory leaks

andris9 · andris9 · commit 6069fdcff68a · 2026-02-02T08:22:45.000+01:00
- Clear socket timeout before destruction to prevent timer leaks
- Explicitly remove all socket event listeners in close() method
- Remove error listener from plain socket after TLS upgrade
diff --git a/lib/smtp-connection/index.js b/lib/smtp-connection/index.js
@@ -414,6 +414,14 @@ class SMTPConnection extends EventEmitter {
 
         if (socket && !socket.destroyed) {
             try {
+                // Clear socket timeout to prevent timer leaks
+                socket.setTimeout(0);
+                // Remove all listeners to allow proper garbage collection
+                socket.removeListener('data', this._onSocketData);
+                socket.removeListener('timeout', this._onSocketTimeout);
+                socket.removeListener('close', this._onSocketClose);
+                socket.removeListener('end', this._onSocketEnd);
+                socket.removeListener('error', this._onSocketError);
                 socket[closeMethod]();
             } catch (_E) {
                 // just ignore
@@ -941,8 +949,10 @@ class SMTPConnection extends EventEmitter {
                 this.upgrading = false;
                 this._socket.on('data', this._onSocketData);
 
+                // Remove all listeners from the plain socket to allow proper garbage collection
                 socketPlain.removeListener('close', this._onSocketClose);
                 socketPlain.removeListener('end', this._onSocketEnd);
+                socketPlain.removeListener('error', this._onSocketError);
 
                 return callback(null, true);
             });
