Issue #20453 has been updated by dodecadaniel (Daniel Colson). I opened https://github.com/ruby/ruby/pull/10630. I'm still fairly new to all this, so please correct me if I got something wrong! ---------------------------------------- Bug #20453: Pointer being freed was not allocated in Regexp timeout https://bugs.ruby-lang.org/issues/20453#change-108107 * Author: dodecadaniel (Daniel Colson) * Status: Open * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- https://bugs.ruby-lang.org/issues/20228 frees `stk_base` to avoid a memory leak, but `stk_base` is sometimes stack allocated ([see `xalloca`](https://github.com/ruby/ruby/blob/dde99215f2bc60c22a00fc941ff7f714f011e920/regexec.c#L1177-L1181)). So the free only works if the regex stack grows enough that it needs to double ([see `xmalloc` and `xrealloc` in `stack_double`](https://github.com/ruby/ruby/blob/dde99215f2bc60c22a00fc941ff7f714f011e920/regexec.c#L1210-L1249). Reproduction: ```ruby Regexp.timeout = 0.001 /^(a*)x$/ =~ "a" * 1000000 + "x"' ``` I'll open a PR shortly. https://bugs.ruby-lang.org/issues/20228 was backported to 3.3.1, so this bug affects that version as well. -- https://bugs.ruby-lang.org/