Too large queries cause process to crash instead of throwing an error

[odedsh]

When sending a malformed query I expect an exception to be thrown. Instead node crashes with a stack trace that does not allow to debug the issue

This example code reproduces the problem

var mongoose = require("mongoose");
var uuid = require('uuid');

mongoose.set('debug', false);
mongoose.connect("mongodb://localhost:27017/bug_reproduce", {useMongoClient:true, keepAlive:true});

var schema = new mongoose.Schema({
  firstName: String,
  middleName: String,
  lastName: String,
  fullName: String,
  email: String
}, {collection: 'TestCollection'});

var model = mongoose.model("TestCollection", schema);
var ridicolousAmountOfData = new Array(400000)

for (var i=0; i<ridicolousAmountOfData.length; ++i) {
  ridicolousAmountOfData[i] = uuid.v1();
}

console.log("Starting");
model.find({email: {$in: ridicolousAmountOfData}}).lean().exec()
  .then( function() {
    console.log("All is Well");
    process.exit(0);
  })
  .catch(function(err) {console.log("Error Caught")})

The output:

Starting
(node:73146) DeprecationWarning: Mongoose: mpromise (mongoose's default promise library) is deprecated, plug in your own promise library instead: http://mongoosejs.com/docs/promises.html
/Users/oded/wisdo/bug-reproduce/node_modules/mongodb/lib/utils.js:123
    process.nextTick(function() { throw err; });
                                  ^

RangeError: Attempt to write outside buffer bounds
    at Buffer.write (buffer.js:876:13)
    at serializeString (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/parser/serializer.js:41:83)
    at serializeInto (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/parser/serializer.js:600:17)
    at serializeObject (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/parser/serializer.js:308:18)
    at serializeInto (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/parser/serializer.js:776:17)
    at serializeObject (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/parser/serializer.js:308:18)
    at serializeInto (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/parser/serializer.js:776:17)
    at serializeObject (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/parser/serializer.js:308:18)
    at serializeInto (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/parser/serializer.js:776:17)
    at BSON.serialize (/Users/oded/wisdo/bug-reproduce/node_modules/bson/lib/bson/bson.js:58:27)
    at Query.toBin (/Users/oded/wisdo/bug-reproduce/node_modules/mongodb-core/lib/connection/commands.js:140:25)
    at Pool.write (/Users/oded/wisdo/bug-reproduce/node_modules/mongodb-core/lib/connection/pool.js:986:23)
    at Cursor._find (/Users/oded/wisdo/bug-reproduce/node_modules/mongodb-core/lib/cursor.js:286:22)
    at nextFunction (/Users/oded/wisdo/bug-reproduce/node_modules/mongodb-core/lib/cursor.js:591:10)
    at Cursor.next [as _next] (/Users/oded/wisdo/bug-reproduce/node_modules/mongodb-core/lib/cursor.js:699:3)
    at fetchDocs (/Users/oded/wisdo/bug-reproduce/node_modules/mongodb/lib/cursor.js:857:10)

I expected the output to be:

Starting
Error Caught

Note: I understand that the query size is limited and when it is exceeded the query will fail.
However I expect to fail with an error in the Promise thread that caused this.

What happens is that Node crashes in a separate execution thread and I could find no way to figure out what query causes this error.

In my specific scenario an express server was querying one collection to get a list of Ids then using a second collection to look up all the matching documents.
When a user would use a filter condition that would match too many ids the system would simply crash because the resulting query is too large.

[sobafuchs]

oof, this looks like a problem with the underlying bson module which can't handle the size of the array you're passing in. It looks like mongoose isn't containing any errors that might bubble up from the stuff that prepares the data. I'll mark this as a bug for now.