Bug #17756: StringScanner#charpos makes segmentation fault when target.byteslice returns non string value

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.0.0p0 (2020-12-25 revision 95aff21468) [x86_64-darwin20]
• Backport: 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: DONE

[kachick (Kenichi Kamiya)]

GH-PR: https://github.com/ruby/strscan/pull/20

This is a strscan issue.
I'm not sure the best way of how to handle bundled libraries tickets since they are Gemfied.
So I created this ticket just in case.

---

This code makes segmentation fault.

$ ruby -v
ruby 3.0.0p0 (2020-12-25 revision 95aff21468) [x86_64-darwin20]

require 'strscan'
string = 'ruby'
scnanner = StringScanner.new(string)
pre = Module.new do
  def byteslice(*args)
  end
end
string.singleton_class.prepend(pre)
scnanner.charpos

[kachick (Kenichi Kamiya)]

• Status changed from Open to Closed

Applied in changeset git|564ccd095a9d7fbe869031dbf666d61dadfdcb03.

---

[ruby/strscan] Fix segmentation fault of StringScanner#charpos when String#byteslice returns non string value [Bug #17756] (#20)

https://github.com/ruby/strscan/commit/92961cde2b

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN to 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: REQUIRED

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: REQUIRED to 2.6: UNKNOWN, 2.7: REQUIRED, 3.0: DONE

ruby_3_0 7b55ff21b52e818819b698326f80158643175645 merged revision(s) 564ccd095a9d7fbe869031dbf666d61dadfdcb03.