From b76c5760919b33fe15d9350a23ccaebcc905397c Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Fri, 15 Feb 2019 07:49:01 -0800
Subject: listener: fix buffer overflow reading external file.

When an external file is edited, and is longer than the
listener's buffer allows, the buffer overflows, trashing the
other fields in the linenoise structure, and memory beyond.

* parser.c (lino_gets): Decrement nchar in the loop.
Also, eliminate useless return case.
---
 parser.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

(limited to 'parser.c')

diff --git a/parser.c b/parser.c
index d0c4b7a9..0f5d5c99 100644
--- a/parser.c
+++ b/parser.c
@@ -1496,18 +1496,13 @@ static wchar_t *lino_gets(mem_t *stream_in, wchar_t *buf, size_t nchar)
   if (nchar == 0)
     return buf;
 
-  while (nchar > 1) {
+  while (nchar-- > 1) {
     val ch = get_char(stream);
     if (!ch)
       break;
     *ptr++ = c_num(ch);
   }
 
-  if (ptr == buf) {
-    *ptr++ = 0;
-    return 0;
-  }
-
   *ptr++ = 0;
   return buf;
 }
-- 
cgit v1.2.3