From 50a9c88bb34aa59b10d053f685bec36da655fd60 Mon Sep 17 00:00:00 2001
From: Andrei Litvin <andy314@gmail.com>
Date: Wed, 17 Nov 2021 14:28:40 -0500
Subject: [PATCH] Validate value lenght - 0 size value should not copy anything

---
 src/platform/Darwin/DnssdImpl.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/platform/Darwin/DnssdImpl.cpp b/src/platform/Darwin/DnssdImpl.cpp
index 389ed082a73fe4..81c5aa2b3c261e 100644
--- a/src/platform/Darwin/DnssdImpl.cpp
+++ b/src/platform/Darwin/DnssdImpl.cpp
@@ -434,8 +434,9 @@ static CHIP_ERROR GetAddrInfo(void * context, DnssdResolveCallback callback, uin
             // Truncation, but nothing better we can do
             valueLen = sizeof(value) - 1;
         }
-
-        memcpy(value, valuePtr, valueLen - 1);
+        if (valueLen > 1) {
+          memcpy(value, valuePtr, valueLen - 1);
+        }
         value[valueLen] = 0;
 
         sdCtx->textEntries.push_back(TextEntry{ strdup(key), reinterpret_cast<const uint8_t *>(strdup(value)), valueLen });