[issue33113] Query performance is very low and can even lead to denial of service

Tal Einat added the comment: Serhiy, that would be a good idea. A short mention of the issue with a link to an external reference would also suffice IMO. -- ___ Python tracker

[issue33113] Query performance is very low and can even lead to denial of service

Serhiy Storchaka added the comment: Perhaps it would be nice to add a section about catastrophic backtracking and ways of resolving it in the RE Howto. -- ___ Python tracker

[issue33113] Query performance is very low and can even lead to denial of service

Tim Peters added the comment: Note: if you found a regexp like this _in_ the Python distribution, then a bug report would be appropriate. It's certainly possible to write regexps that can suffer catastrophic backtracking, and we've repaired a few of those, over the years, that shipped

[issue33113] Query performance is very low and can even lead to denial of service

Serhiy Storchaka added the comment: I concur with Tal. This problem is called "catastrophic backtracking". -- resolution: -> wont fix stage: -> resolved status: open -> closed ___ Python tracker

[issue33113] Query performance is very low and can even lead to denial of service

Tal Einat added the comment: Clarification: The given pattern is equivalent to that in my previous post, assuming the latter is used with the re.VERBOSE flag. -- ___ Python tracker

[issue33113] Query performance is very low and can even lead to denial of service

Tal Einat added the comment: I suggest closing this as "wontfix". This is a just an non-optimized regexp pattern leading to long run times. That these are possible is a well-known trait of backtracking regular expression engines in general, and ours in particular. IMO this isn't a

[issue33113] Query performance is very low and can even lead to denial of service

Change by Xiang Zhang : -- nosy: +serhiy.storchaka ___ Python tracker ___ ___

[issue33113] Query performance is very low and can even lead to denial of service

New submission from guohui : I found a issue in regex (findall search)function, when seaching some content by some pattern, the function return for a long long time, match performance is very low. I think this issue could lead to too low query performance, or a attacker may