From: nicm <nicm@openbsd.org>
Date: Mon, 30 Oct 2023 16:05:30 +0000 (+0000)
Subject: Do not allow combined UTF-8 characters that are too long, GitHub issue
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=eed425c7caf4153573e2f7e3f2b808c266309eef;p=openbsd

Do not allow combined UTF-8 characters that are too long, GitHub issue
3729.
---

diff --git a/usr.bin/tmux/screen-write.c b/usr.bin/tmux/screen-write.c
index 45b36c8f3a1..71b7f99cadf 100644
--- a/usr.bin/tmux/screen-write.c
+++ b/usr.bin/tmux/screen-write.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-write.c,v 1.223 2023/10/23 08:12:00 nicm Exp $ */
+/* $OpenBSD: screen-write.c,v 1.224 2023/10/30 16:05:30 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -2025,6 +2025,10 @@ screen_write_combine(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 			return (0);
 	}
 
+	/* Check if this combined character would be too long. */
+	if (last.data.size + ud->size > sizeof last.data.data)
+		return (0);
+
 	/* Combining; flush any pending output. */
 	screen_write_collect_flush(ctx, 0, __func__);