Bug #22415: Thread.handle_interrupt needs to preserve errinfo

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

[rwstauner (Randy Stauner)]

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:

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"

[rwstauner (Randy Stauner)]

bugfix PR: https://github.com/ruby/ruby/pull/19260

[rwstauner (Randy Stauner)]

This is similar to https://bugs.ruby-lang.org/issues/22240 except that the same fix can be applied inside Ruby itself (instead of the fault being from native extensions).

[rwstauner (Randy Stauner)]

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

[rwstauner (Randy Stauner)]

3.4 Backport PR: https://github.com/ruby/ruby/pull/19262

[rwstauner (Randy Stauner)]

3.3 backport PR: https://github.com/ruby/ruby/pull/19264