Bug #20942: Infinite loop when out of memory

• Status: Open
• Assignee: -
• Target version: -
• ruby -v: ruby 3.4.0dev (2024-12-10T10:28:22Z master 3568e7aef7) +PRISM [aarch64-linux]
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[segiddins (Samuel Giddins)]

Similar setup to https://bugs.ruby-lang.org/issues/20941
Pure-ruby reproduction of https://bugs.ruby-lang.org/issues/20629

#!/usr/bin/env -S RUBYOPT="--disable-gems"  gdb --args ruby -v

STDOUT.sync = true

es = Array.new(10000) { Object.new }
es = Array.new(10000) { 0 }

Process.warmup
puts "warmup"

Process.setrlimit(:DATA, 0)

i = 0
loop do
  begin
    Array.new(-1)
  rescue ArgumentError => e
    es[i += 1] = e
  end
end

Backtrace every time I pause in the debugger:

(gdb) bt
#0  rb_multi_ractor_p () at /usr/src/ruby/vm_sync.h:40
#1  rb_vm_lock_leave (line=245, file=<synthetic pointer>, lev=<synthetic pointer>) at /usr/src/ruby/vm_sync.h:92
#2  rb_ec_vm_lock_rec_release (ec=ec@entry=0xaaaaaaabb4f0, recorded_lock_rec=0, current_lock_rec=1) at /usr/src/ruby/vm_sync.c:245
#3  0x0000fffff7c3badc in rb_ec_vm_lock_rec_check (recorded_lock_rec=<optimized out>, ec=0xaaaaaaabb4f0) at /usr/src/ruby/eval_intern.h:136
#4  rb_ec_tag_state (ec=0xaaaaaaabb4f0) at /usr/src/ruby/eval_intern.h:147
#5  rb_vm_exec (ec=0xaaaaaaabb4f0) at /usr/src/ruby/vm.c:2584
#6  0x0000fffff7a52c18 in rb_ec_exec_node (ec=ec@entry=0xaaaaaaabb4f0, n=n@entry=0xfffff72c5068) at /usr/src/ruby/eval.c:281
#7  0x0000fffff7a563b4 in ruby_run_node (n=0xfffff72c5068) at /usr/src/ruby/eval.c:319
#8  0x0000aaaaaaaa0b6c in rb_main (argv=0xfffffffffce8, argc=3) at /usr/src/ruby/main.c:43
#9  main (argc=<optimized out>, argv=<optimized out>) at /usr/src/ruby/main.c:68