YAML bug: ruby 1.8.1 (2003-12-05) [i686-linux]

ruby-talk
1

When dumping a Hash containing a string with a length greater than about 4100,
ruby segfaults:

...
4099
4100
4101
4102
4103
/pkg/ruby.2/lib/ruby/1.8/yaml.rb:193: [BUG] Segmentation fault
ruby 1.8.1 (2003-12-05) [i686-linux]

Easily reproduced here with simple test

#!/bin/ruby

require 'yaml'

len = 1
while true
	a = {"test"=>'x'*len}
	puts len
	b = YAML.dump(a)
	len += 1
end

I’ve tried two different machines; The magic number of one is 4103 and the
other is 4175

This is coincidentally close to a 4k buffer perhaps???

Andrew Walrond

2

  /pkg/ruby.2/lib/ruby/1.8/yaml.rb:193: [BUG] Segmentation fault
  ruby 1.8.1 (2003-12-05) [i686-linux]

Well, probably the bug is corrected in the CVS version.

To be sure, run your program under the debugger and when it crash execute
the command `bt'

Guy Decoux

3

“Andrew Walrond” andrew@walrond.org schrieb im Newsbeitrag
news:200401151124.23571.andrew@walrond.org…

When dumping a Hash containing a string with a length greater than about
4100,
ruby segfaults:

…
4099
4100
4101
4102
4103
/pkg/ruby.2/lib/ruby/1.8/yaml.rb:193: [BUG] Segmentation fault
ruby 1.8.1 (2003-12-05) [i686-linux]

Easily reproduced here with simple test

#!/bin/ruby

require ‘yaml’

len = 1
while true
a = {“test”=>‘x’*len}
puts len
b = YAML.dump(a)
len += 1
end

I’ve tried two different machines; The magic number of one is 4103 and
the
other is 4175

This is coincidentally close to a 4k buffer perhaps???

This happens on cygwin:

8187
8188
8189
8190
8191
8192
/usr/lib/ruby/1.8/yaml/rubytypes.rb:315:in simple': failed to allocate memory ( NoMemoryError) from /usr/lib/ruby/1.8/yaml/rubytypes.rb:315:in to_yaml’
from /usr/lib/ruby/1.8/yaml/rubytypes.rb:293:in call' from /usr/lib/ruby/1.8/yaml.rb:188:in quick_emit’
from /usr/lib/ruby/1.8/yaml/rubytypes.rb:293:in to_yaml' from /usr/lib/ruby/1.8/yaml/baseemitter.rb:175:in map’
from /usr/lib/ruby/1.8/yaml/baseemitter.rb:164:in each' from /usr/lib/ruby/1.8/yaml/baseemitter.rb:164:in map’
from /usr/lib/ruby/1.8/yaml/rubytypes.rb:60:in to_yaml' from /usr/lib/ruby/1.8/yaml/rubytypes.rb:55:in call’
from /usr/lib/ruby/1.8/yaml.rb:188:in quick_emit' from /usr/lib/ruby/1.8/yaml/rubytypes.rb:55:in to_yaml’
from /usr/lib/ruby/1.8/yaml.rb:31:in `dump’
from ./yaml-bug.rb:10

13:04:39 [ruby]: ruby -v
ruby 1.8.1 (2003-12-25) [i386-cygwin]

These behave identical (mem allocation error):

#!/bin/ruby

hash created outside of loop

require ‘yaml’

len = 1
a={}

while true
a[“test”] = ‘x’*len
puts len
b = YAML.dump(a)
len += 1
end

#!/bin/ruby

only one string instance

require ‘yaml’

str = ‘’

while true
a = {“test”=>str}
puts str.length
b = YAML.dump(a)
str << ‘x’
end

#!/bin/ruby

only 1 string and 1 Hash

require ‘yaml’

str = ‘’
a = {}

while true
a[“test”]=str
puts str.length
b = YAML.dump(a)
str << ‘x’
end

Regards

robert