From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Mon, 11 Nov 2019 12:27:55 +0000 (+0200)
Subject: imap-hibernate: Fix crash when imap-master communication fails
X-Git-Tag: 2.3.10~286
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=64a176b122f6378185ce5ee9e0cbf3b3523050b3;p=thirdparty%2Fdovecot%2Fcore.git

imap-hibernate: Fix crash when imap-master communication fails

Fixes a segfault if the communication times out or gets disconnected too
early. This happens because read_callback() already frees the
imap_master_connection.
---

diff --git a/src/imap-hibernate/imap-master-connection.c b/src/imap-hibernate/imap-master-connection.c
index a44785333c..a058a68799 100644
--- a/src/imap-hibernate/imap-master-connection.c
+++ b/src/imap-hibernate/imap-master-connection.c
@@ -54,15 +54,23 @@ int imap_master_connection_init(const char *path,
 	return 1;
 }
 
-void imap_master_connection_deinit(struct imap_master_connection **_conn)
+static void
+imap_master_read_callback(struct imap_master_connection **_conn,
+			  const char *line)
 {
 	struct imap_master_connection *conn = *_conn;
+	imap_master_connection_read_callback_t *read_callback =
+		conn->read_callback;
 
 	*_conn = NULL;
+	conn->read_callback = NULL;
+	read_callback(conn->context, line);
+	/* connection is destroyed now */
+}
 
-	if (conn->read_callback != NULL)
-		conn->read_callback(conn->context, "-");
-	imap_master_connection_free(&conn);
+void imap_master_connection_deinit(struct imap_master_connection **_conn)
+{
+	imap_master_read_callback(_conn, "-");
 }
 
 void imap_master_connection_free(struct imap_master_connection **_conn)
@@ -97,11 +105,7 @@ imap_master_client_input_line(struct connection *_conn, const char *line)
 		conn->send_callback(conn->context, _conn->output);
 		return 1;
 	} else {
-		imap_master_connection_read_callback_t *read_callback =
-			conn->read_callback;
-
-		conn->read_callback = NULL;
-		read_callback(conn->context, line);
+		imap_master_read_callback(&conn, line);
 		/* we're finished now with this connection - disconnect it */
 		return -1;
 	}