From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Tue, 29 Oct 2024 08:36:43 +0000 (+0200)
Subject: imap: Fix potential hang/assert-crash when client sends too long line
X-Git-Tag: 2.4.0~1428
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=06446b47de0ef2eac1bfa8ff248d79dbac30431b;p=thirdparty%2Fdovecot%2Fcore.git

imap: Fix potential hang/assert-crash when client sends too long line

If client sent some commands pipelined, followed by a command with too long
line, the previous commands' tagged replies weren't sent. This caused it to
hang until more input was received. After that it crashed.

Fixes:
Panic: file imap-client.c: line 1098 (client_check_command_hangs): assertion failed: (!have_wait_unfinished || unfinished_count > 0)
---

diff --git a/src/imap/imap-client.c b/src/imap/imap-client.c
index f9dbe1d55c..b157971460 100644
--- a/src/imap/imap-client.c
+++ b/src/imap/imap-client.c
@@ -1432,6 +1432,10 @@ void client_input(struct client *client)
 		cmd->param_error = TRUE;
 		client_send_command_error(cmd, "Too long argument.");
 		client_command_free(&cmd);
+
+		/* We may have delayed syncing previous commands to handle this
+		   one. Do it now to avoid hanging. */
+		(void)cmd_sync_delayed(client);
 	}
 	o_stream_uncork(output);
 	o_stream_unref(&output);