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Nan::Callback::Call improperly garbage collects the return value under Node 10.12, causing segfaults #813
Description
Under Node 10.12, calling the Call method of a Nan::Callback object returns a garbage object that appears to have been prematurely garbage collected. I have put together a toy extension that demonstrates this:
main.cc:
#include <node.h>
#include <nan.h>
NAN_METHOD(RunCallback) {
if (!info[0]->IsFunction()) {
return Nan::ThrowTypeError("Argument must be function");
}
Nan::Callback *callback = new Nan::Callback(v8::Local<v8::Function>::Cast(info[0]));
int argc = 0;
v8::Local<v8::Value> argv[argc] = {};
v8::Local<v8::Value> result = callback->Call(argc, argv);
if (result->IsNumber()) {
info.GetReturnValue().Set(Nan::True());
} else {
info.GetReturnValue().Set(Nan::False());
}
}
void init(v8::Local<v8::Object> exports) {
Nan::Set(exports, Nan::New("runCallback").ToLocalChecked(),
Nan::GetFunction(Nan::New<v8::FunctionTemplate>(RunCallback)).ToLocalChecked());
}
NODE_MODULE(callback_test, init);index.js:
const callbackTest = require('./build/Release/callback_test.node');
console.log(callbackTest.runCallback(() => {return 1;}));binding.gyp:
{
"targets": [
{
"target_name": "callback_test",
"sources": [ "main.cc" ],
"include_dirs" : [
"<!(node -e \"require('nan')\")"
]
}
]
}Running index.js with Node 10.11 correctly outputs "true", and running it with Node 10.12 causes a segmentation fault in result->IsNumber(). The code works correctly under Node 10.12 if the callback->Call line is replaced with
v8::Local<v8::Value> result = Nan::Call(*callback, argc, argv).ToLocalChecked();
Activity
addaleax commentedon Oct 17, 2018
I think the issue is that this line requires an additional
scope.Escape()? 1caf258#diff-558c37be49a47656e3ff41806c24bd33R1624 /cc @kkoopakkoopa commentedon Oct 17, 2018
Flarna commentedon Oct 19, 2018
The change suggested by @addaleax solves the issue.
I was able to reproduce this and created a PR: #817