From ca290e85eab4953f0188bd022bf829228c9af5e3 Mon Sep 17 00:00:00 2001
From: yinshengkai <yinshengkai@xiaomi.com>
Date: Mon, 13 Mar 2023 22:42:00 +0800
Subject: [PATCH] libc: stream adds length check

Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
---
 libs/libc/stream/lib_syslogstream.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libs/libc/stream/lib_syslogstream.c b/libs/libc/stream/lib_syslogstream.c
index 9566d7cbbc..21eb8654f9 100644
--- a/libs/libc/stream/lib_syslogstream.c
+++ b/libs/libc/stream/lib_syslogstream.c
@@ -200,6 +200,11 @@ static int syslogstream_puts(FAR struct lib_outstream_s *this,
   int ret = 0;
 
   DEBUGASSERT(stream != NULL);
+  if (len <= 0)
+    {
+      return 0;
+    }
+
   stream->last_ch = ((FAR const char *)buff)[len -1];
 
 #ifdef CONFIG_SYSLOG_BUFFER