From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Tue, 9 Jun 2026 20:41:14 +0000 (+0000)
Subject: login-common: Fix connection hanging if ostream write fails
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;p=thirdparty%2Fdovecot%2Fcore.git

login-common: Fix connection hanging if ostream write fails

If the ostream write failed, the istream was closed. This prevented its IO
callback from being called, so the connection was just stuck.

This happaned at least with haproxy health check connections.
---

diff --git a/src/login-common/client-common.c b/src/login-common/client-common.c
index 1cc1b2dcbb..ec954d63f7 100644
--- a/src/login-common/client-common.c
+++ b/src/login-common/client-common.c
@@ -1649,6 +1649,11 @@ void client_notify_status(struct client *client, bool bad, const char *text)
 		client->v.notify_status(client, bad, text);
 }
 
+static void client_send_raw_data_destroy(struct client *client)
+{
+	client_destroy(client, "Disconnected: Output error");
+}
+
 void client_common_send_raw_data(struct client *client,
 				 const void *data, size_t size)
 {
@@ -1659,8 +1664,18 @@ void client_common_send_raw_data(struct client *client,
 		/* either disconnection or buffer full. in either case we want
 		   this connection destroyed. however destroying it here might
 		   break things if client is still tried to be accessed without
-		   being referenced.. */
+		   being referenced, so do it lazily from a timeout. */
+		io_remove(&client->io);
 		i_stream_close(client->input);
+		/* If the client is already being destroyed, don't schedule
+		   another destroy. Its to_disconnect was already removed and
+		   wouldn't be cleaned up again, leaking the timeout. */
+		if (!client->destroyed) {
+			timeout_remove(&client->to_disconnect);
+			client->to_disconnect =
+				timeout_add_short(0,
+					client_send_raw_data_destroy, client);
+		}
 	}
 }