From 4221b1c8c942912b14d05ad03c24f9009b26ba94 Mon Sep 17 00:00:00 2001
From: Matt Kulukundis <matt.fowles@gmail.com>
Date: Thu, 16 Apr 2020 19:30:08 -0400
Subject: [PATCH] src: fix null deref in AllocatedBuffer::clear
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An empty buffer can have a null environment.  Previously, we were
getting away with with this, but -fsanitize=null in clang caught it.

PR-URL: https://github.com/nodejs/node/pull/32892
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
---
 src/env-inl.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/env-inl.h b/src/env-inl.h
index 853c74f3e5b0f1..9ba5bebe00cb27 100644
--- a/src/env-inl.h
+++ b/src/env-inl.h
@@ -995,7 +995,10 @@ inline AllocatedBuffer::~AllocatedBuffer() {
 
 inline void AllocatedBuffer::clear() {
   uv_buf_t buf = release();
-  env_->Free(buf.base, buf.len);
+  if (buf.base != nullptr) {
+    CHECK_NOT_NULL(env_);
+    env_->Free(buf.base, buf.len);
+  }
 }
 
 // It's a bit awkward to define this Buffer::New() overload here, but it