Brakeman hangs on some platforms

[stanley90]

Background

Brakeman version: 6.1.1
Rails version: 6.1.7.6
Ruby version: 3.1.4

Hanging or Slowness

Brakeman (4.10.0) has been hanging since I moved to a Macbook Pro M1, but the same scan worked on an Ubuntu server. Currently I upgraded to 6.1.1 and in addition to hanging locally, it now also hangs on an Azure Ubuntu 20 image (but still works on the Ubuntu 22 server).

I narrowed the problem down to an individual file, the scan works when the file is skipped. The exception after interrupting is:

Interrupted - exiting.
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/bundle/ruby/3.0.0/gems/sexp_processor-4.17.0/lib/sexp.rb:36:in `initialize'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/bundle/ruby/3.0.0/gems/sexp_processor-4.17.0/lib/sexp.rb:36:in `initialize'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:28:in `new'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:28:in `deep_clone'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:32:in `block in deep_clone'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:30:in `each'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:30:in `deep_clone'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:32:in `block in deep_clone'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:30:in `each'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:30:in `deep_clone'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:32:in `block in deep_clone'
/Users/stanley/.asdf/installs/ruby/3.1.4/lib/ruby/gems/3.1.0/gems/brakeman-6.1.1/lib/ruby_parser/bm_sexp.rb:30:in `each'

I can provide the file privately (it's a module included in several controllers).

[presidentbeef]

Just as a guess, the machines that work probably have more memory?

I'd be interested in looking at the file - you can send it to brakeman@presidentbeef.com 📧

[stanley90]

Just as a guess, the machines that work probably have more memory?

Wouldn't bet on that, both have 16GB (though there is definitely a difference in how much stuff is running on which machine).

I'd be interested in looking at the file - you can send it to brakeman@presidentbeef.com 📧

Sending.

[presidentbeef]

@stanley90 Brakeman is struggling due to many conditional re-assignments to the same variable that also use the variable as part of the new value (e.g. x = f(x) if y - take a look at the first method in the file you shared). This is the most common performance issue I see.

I have a potential fix I'll add soon.

[stanley90]

@presidentbeef Not the prettiest file, I know 🙂 I can then test it, if it helps.

[presidentbeef]

Fixed with #1820