From: "rwstauner (Randy Stauner) via ruby-core" <ruby-core@...>
Date: 2026-10-07T21:30:18+00:00
Subject: [ruby-core:126995] [Ruby Bug#22415] Thread.handle_interrupt needs to preserve errinfo

Issue #22415 has been updated by rwstauner (Randy Stauner).


4.0 backport PR: https://github.com/ruby/ruby/pull/19261

----------------------------------------
Bug #22415: Thread.handle_interrupt needs to preserve errinfo
https://bugs.ruby-lang.org/issues/22415#change-119387

* Author: rwstauner (Randy Stauner)
* Status: Open
* Backport: 3.3: REQUIRED, 3.4: REQUIRED, 4.0: REQUIRED
----------------------------------------
Thread.handle_interrupt checks for interrupts after its block has returned but before re-raising the break/return that left the block.  A signal trap that runs in that window clears ec->errinfo, which is where the throw data for the pending break/return lives, so the VM throws nil.

This small script reproduces the SEGV very quickly:

```ruby
trap(:USR1) { raise "boom" rescue nil }

pid = $$
killer = fork { (Process.kill(:USR1, pid); sleep 0.001) while Process.ppid == pid }

1_000_000.times { Thread.handle_interrupt(Exception => :immediate) { break } }

Process.kill(:KILL, killer)
puts "no crash"
```



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