src,inspector: fix empty MaybeLocal crash

Return early when the Inspector StringView to V8 String conversion fails and returns an empty MaybeLocal instead of running the invalid ToLocalChecked() assertion. Fixes: #42407 Signed-off-by: Darshan Sen <[email protected]> PR-URL: #42409 Reviewed-By: Richard Lau <[email protected]> Reviewed-By: Mohammed Keyvanzadeh <[email protected]> Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Tobias Nießen <[email protected]> Reviewed-By: Juan José Arboleda <[email protected]> Reviewed-By: James M Snell <[email protected]>
nodejs · Apr 9, 2022 · be01185 · be01185
1 parent dfc2dc8
commit be01185
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Showing 2 changed files with 24 additions and 4 deletions.
diff --git a/src/inspector_js_api.cc b/src/inspector_js_api.cc
@@ -75,10 +75,10 @@ class JSBindingsConnection : public AsyncWrap {
       Isolate* isolate = env_->isolate();
       HandleScope handle_scope(isolate);
       Context::Scope context_scope(env_->context());
-      MaybeLocal<String> v8string =
-          String::NewFromTwoByte(isolate, message.characters16(),
-                                 NewStringType::kNormal, message.length());
-      Local<Value> argument = v8string.ToLocalChecked().As<Value>();
+      Local<Value> argument;
+      if (!String::NewFromTwoByte(isolate, message.characters16(),
+                                  NewStringType::kNormal,
+                                  message.length()).ToLocal(&argument)) return;
       connection_->OnMessage(argument);
     }
 

diff --git a/test/pummel/test-repl-empty-maybelocal-crash.js b/test/pummel/test-repl-empty-maybelocal-crash.js
@@ -0,0 +1,20 @@
+'use strict';
+const common = require('../common');
+
+if (process.config.variables.arm_version === '7') {
+  common.skip('Too slow for armv7 bots');
+}
+
+// The process should not crash when the REPL receives the string, 'ss'.
+// Test for https://github.com/nodejs/node/issues/42407.
+
+const repl = require('repl');
+
+const r = repl.start();
+
+r.write('var buf = Buffer.from({length:200e6},(_,i) => i%256);\n');
+r.write('var ss = buf.toString("binary");\n');
+r.write('ss');
+r.write('.');
+
+r.close();