src: check for empty maybe local

Xstoudi · targos · commit 13a7e0546f38 · 2020-04-22T18:25:05.000+02:00
Using ToLocalChecked on MaybeLocal without verifying it's empty can lead to unattempted crash. PR-URL: #32339 Reviewed-By: Michaël Zasso <targos@protonmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: David Carlier <devnexen@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
diff --git a/src/udp_wrap.cc b/src/udp_wrap.cc
@@ -477,7 +477,8 @@ void UDPWrap::DoSend(const FunctionCallbackInfo<Value>& args, int family) {
 
   // construct uv_buf_t array
   for (size_t i = 0; i < count; i++) {
-    Local<Value> chunk = chunks->Get(env->context(), i).ToLocalChecked();
+    Local<Value> chunk;
+    if (!chunks->Get(env->context(), i).ToLocal(&chunk)) return;
 
     size_t length = Buffer::Length(chunk);
 
