src: no abort from getter if object isn't wrapped

v8::Object::GetAlignedPointerFromInternalField() returns a random value
if Wrap() hasn't been run on the object handle. Causing v8 to abort if
certain getters are accessed. It's possible to access these getters and
functions during class construction through the AsyncWrap init()
callback, and also possible in a subset of those scenarios while running
the persistent handle visitor.

Mitigate this issue by manually setting the internal aligned pointer
field to nullptr in the BaseObject constructor and add necessary logic
to return appropriate values when nullptr is encountered.

PR-URL: https://github.com/nodejs/node/pull/6184
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 12 insertions, 6 deletions

diff --git a/src/pipe_wrap.cc b/src/pipe_wrap.cc
index 7be07de74b2..286ea30a87c 100644
--- a/src/pipe_wrap.cc
+++ b/src/pipe_wrap.cc
@@ -138,7 +138,8 @@ PipeWrap::PipeWrap(Environment* env,
 
 
 void PipeWrap::Bind(const FunctionCallbackInfo<Value>& args) {
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   node::Utf8Value name(args.GetIsolate(), args[0]);
   int err = uv_pipe_bind(&wrap->handle_, *name);
   args.GetReturnValue().Set(err);
@@ -147,7 +148,8 @@ void PipeWrap::Bind(const FunctionCallbackInfo<Value>& args) {
 
 #ifdef _WIN32
 void PipeWrap::SetPendingInstances(const FunctionCallbackInfo<Value>& args) {
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   int instances = args[0]->Int32Value();
   uv_pipe_pending_instances(&wrap->handle_, instances);
 }
@@ -155,7 +157,8 @@ void PipeWrap::SetPendingInstances(const FunctionCallbackInfo<Value>& args) {
 
 
 void PipeWrap::Listen(const FunctionCallbackInfo<Value>& args) {
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   int backlog = args[0]->Int32Value();
   int err = uv_listen(reinterpret_cast<uv_stream_t*>(&wrap->handle_),
                       backlog,
@@ -191,7 +194,8 @@ void PipeWrap::OnConnection(uv_stream_t* handle, int status) {
   Local<Object> client_obj = Instantiate(env, pipe_wrap);
 
   // Unwrap the client javascript object.
-  PipeWrap* wrap = Unwrap<PipeWrap>(client_obj);
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, client_obj);
   uv_stream_t* client_handle = reinterpret_cast<uv_stream_t*>(&wrap->handle_);
   if (uv_accept(handle, client_handle))
     return;
@@ -242,7 +246,8 @@ void PipeWrap::AfterConnect(uv_connect_t* req, int status) {
 void PipeWrap::Open(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   int fd = args[0]->Int32Value();
 
@@ -256,7 +261,8 @@ void PipeWrap::Open(const FunctionCallbackInfo<Value>& args) {
 void PipeWrap::Connect(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   CHECK(args[0]->IsObject());
   CHECK(args[1]->IsString());