Bug #10223: Stack level too deep in CSV when parsing long line

• Status: Closed
• Assignee: -
• Target version: 2.2.0
• ruby -v: ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-linux], ruby 2.1.2p95 (2014-05-08 revision 45877) [x86_64-linux]
• Backport: 2.0.0: REQUIRED, 2.1: REQUIRED

[apohllo (Aleksander Pohl)]

The following code:

#!/usr/bin/env ruby                                                                                                                                                        
# encoding: utf-8

require 'bundler/setup'
require 'csv'

CSV.open("csv_error.csv") do |input|
  input.each do |category,*mappings|
    # do nothing
  end
end

with the data file attached causes the follwing error:

/usr/local/rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/csv.rb:1768: stack level too deep (SystemStackError)

Interestingly almost the same code:

#!/usr/bin/env ruby                                                                                                                                                        
# encoding: utf-8

require 'bundler/setup'
require 'csv'

CSV.open("csv_error.csv") do |input|
  input.each do |tuple|
    # do nothing
  end
end

works fine. The error appears both in Ruby 1.9.2 (ancient) and Ruby 2.1.2. So I suppose it is an error inside CSV lib.

This might be important for any developer parsing CSV files comming from the outside world, since it may cause DOS error.

[apohllo (Aleksander Pohl)]

I guess, that CSV has not much to do with that error. Probably the root cause is that *mappings inside

|category,*mappings|

is a very long array, which is (de)composed recursively. And this causes the Stack-level to deep problem.

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)
• Priority changed from 5 to Normal
• Target version set to 2.2.0
• Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN to 2.0.0: REQUIRED, 2.1: REQUIRED

The shortest code would be:

def t;yield [0]*200000; end
t{|a,|}

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

[usa (Usaku NAKAMURA)]

How did you make Closed, nobu?