[ruby-dev:50031] [Ruby trunk Bug#13352] RegExp infinite looping

Issue #13352 has been updated by duerst (Martin D=C3=BCrst).


I haven't yet had time to analyze the regular expression in detail. Are you=
 sure this is really an infinite loop, and not just a case of exponentially=
 slow processing (e.g. similar to stackoverflow.com/questions/16580665/node=
-js-regex-engine-fails-on-large-input)?

----------------------------------------
Bug #13352: RegExp infinite looping
https://bugs.ruby-lang.org/issues/13352#change-63729

* Author: jumnichi_kose (=E5=B0=8F=E7=80=AC =E6=B7=B3=E4=B8=80)
* Status: Open
* Priority: Normal
* Assignee:=20
* Target version:=20
* ruby -v: 2.3.3p222 (2016-11-21 revision 56859) [x64-mingw32],  ruby 2.2.4=
p230 (2015-12-16 revision 53155) [i386-mingw32]
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
----------------------------------------
ruby entered an infinite loop with the following three steps.

~~~ ruby
r =3D /(?=3D\W)\W?(?:(?:(?:\/\*<)?[\'\"]?([\w_\$]+)[\'\"]?(?:>\*\/\s+this)?=
|(this))\.(\$scope|json)|([\'\"](?:\$scope|json)[\'\"]))((\.)(inputObjects)=
|(\.)(spreadSheets)(?:\.[\'\"]?([^\.\'\"\|\s,]+)[\'\"]?|\[[\'\"]?((?:[^\'\"=
\]\[]*|\[[^\]]*\])*)[\'\"]?\])(\.)(model))\s*(?:\.[\'\"]?([^\.\'\"\|\s,]+)[=
\'\"]?|\[[\'\"]?((?:[^\'\"\]\[]*|\[[^\]]*\])*)[\'\"]?\])/
txt =3D ".model |,| 'anController'.$scope.inputObjects['fieldName .../* !! =
comment ...*/"
txt.scan r
~~~

Node.js also falls into an infinite loop.
~~~ javascript
var r =3D /(?=3D\W)\W?(?:(?:(?:\/\*<)?[\'\"]?([\w_\$]+)[\'\"]?(?:>\*\/\s+th=
is)?|(this))\.(\$scope|json)|([\'\"](?:\$scope|json)[\'\"]))((\.)(inputObje=
cts)|(\.)(spreadSheets)(?:\.[\'\"]?([^\.\'\"\|\s,]+)[\'\"]?|\[[\'\"]?((?:[^=
\'\"\]\[]*|\[[^\]]*\])*)[\'\"]?\])(\.)(model))\s*(?:\.[\'\"]?([^\.\'\"\|\s,=
]+)[\'\"]?|\[[\'\"]?((?:[^\'\"\]\[]*|\[[^\]]*\])*)[\'\"]?\])/
var txt =3D ".model |,| 'anController'.$scope.inputObjects['fieldName .../*=
 !! comment ...*/"

var s =3Dr.exec (txt)

console.log(s)


~~~





--=20
https://bugs.ruby-lang.org/