Bug #22535: Release mode segfault due to half-initialized error in singleton_method

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 3.3: DONTNEED, 3.4: REQUIRED, 4.0: REQUIRED

[tekknolagi (Maxwell Bernstein)]

This causes a segfault seemingly only in release mode:

name = "never_interned_#{rand(10**12)}"
begin
  Object.new.singleton_method(name)
rescue NameError => e
  STDERR.puts "rescued #{e.class}; e.name.class = #{e.name.class}"
  STDERR.puts e.message          # segfaults here (rb_sym_to_s on ID2SYM(0))
end

[jhawthorn (John Hawthorn)]

Fix: https://github.com/ruby/ruby/pull/19839

[jhawthorn (John Hawthorn)]

• Status changed from Open to Closed

Applied in changeset git|45666487ee3868605bc6fd792f21ff8ac42264da.

---

Fix NameError from singleton_method for a name with no ID

rb_check_id returns 0 when the name has no ID, and we were passing that
to ID2SYM. 0 is never a valid ID, so also assert against it in
rb_id2sym.

[Bug #22535]

[jhawthorn (John Hawthorn)]

• Backport changed from 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN to 3.3: DONTNEED, 3.4: REQUIRED, 4.0: REQUIRED

4.0: https://github.com/ruby/ruby/pull/19848
3.4: https://github.com/ruby/ruby/pull/19849