From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Thu, 11 Jan 2018 18:38:14 +0000 (-0500)
Subject: *-login: Fix clients linked list corruption with SSL connections
X-Git-Tag: 2.3.1~229
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1c3b6f9221dc2a5270fe691bb625d0630196508e;p=thirdparty%2Fdovecot%2Fcore.git

*-login: Fix clients linked list corruption with SSL connections

This could have resulted in infinite loops or some of the clients being
skipped for some operations.
---

diff --git a/src/login-common/client-common.c b/src/login-common/client-common.c
index 636af8b0d4..a3c6d7a54c 100644
--- a/src/login-common/client-common.c
+++ b/src/login-common/client-common.c
@@ -261,6 +261,7 @@ void client_disconnect(struct client *client, const char *reason)
 		   so don't disconnect the client until client_unref(). */
 		if (client->iostream_fd_proxy != NULL) {
 			client->fd_proxying = TRUE;
+			i_assert(client->prev == NULL && client->next == NULL);
 			DLLIST_PREPEND(&client_fd_proxies, client);
 			client_fd_proxies_count++;
 		}
@@ -275,14 +276,16 @@ void client_destroy(struct client *client, const char *reason)
 		return;
 	client->destroyed = TRUE;
 
-	client_disconnect(client, reason);
-
-	pool_unref(&client->preproxy_pool);
-
 	if (last_client == client)
 		last_client = client->prev;
+	/* remove from clients linked list before it's added to
+	   client_fd_proxies. */
 	DLLIST_REMOVE(&clients, client);
 
+	client_disconnect(client, reason);
+
+	pool_unref(&client->preproxy_pool);
+
 	if (client->master_tag != 0) {
 		i_assert(client->auth_request == NULL);
 		i_assert(client->authenticating);