io_delimited_ios_hotpatch

Recent versions of Crystal -- 1.12.2, at least, though maybe other versions, as well -- have a bug that can be exposed by doing a file upload with a multipart form, from an iOS platform. The problem is still be isolated in specific detail, but the failure is related to a Slice overrun. Something about how iOS is returning the data triggers an execution path that results in IO::Delimited#read_with_peek attempting to copy more data into a buffer than there is space for it.

This current fix doesn't address the root problem, but it does address the symptom. It adds a check to IO::Delimited#read_with_peek to ensure that the buffer has enough space for the data that is being copied into it. If it doesn't, the buffer is resized to be large enough.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     io_delimited_ios_hotpatch:
       github: wyhaines/io_delimited_ios_hotpatch.cr
   

2. Run shards install

Usage

require "io_delimited_ios_hotpatch"

Contributing

1. Fork it (https://github.com/wyhaines/io_delimited_ios_hotpatch/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Kirk Haines - creator and maintainer