From 1b4c56cf5aead8cf45357bf32060fa0de848f186 Mon Sep 17 00:00:00 2001
From: BoB13-Matter <bob13wtm@gmail.com>
Date: Fri, 3 Jan 2025 09:53:25 +0900
Subject: [PATCH] Add nullptr check for String TLV data with zero length
 (#36921)

* Add nullptr check for String TLV data with zero length

* Compare len instead of buf
---
 src/lib/support/BufferWriter.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/support/BufferWriter.cpp b/src/lib/support/BufferWriter.cpp
index 2ba03e22d24e03..3f9a51fe18b815 100644
--- a/src/lib/support/BufferWriter.cpp
+++ b/src/lib/support/BufferWriter.cpp
@@ -30,7 +30,7 @@ BufferWriter & BufferWriter::Put(const void * buf, size_t len)
 {
     size_t available = Available();
 
-    if (available > 0)
+    if (available > 0 && len > 0)
     {
         memmove(mBuf + mNeeded, buf, available < len ? available : len);
     }