From 8409edc4971f34cf0d77c375909c5b8f7b1e058a Mon Sep 17 00:00:00 2001 From: John Hawthorn Date: Mon, 4 Nov 2024 18:05:59 -0800 Subject: [PATCH] Fix regex timeout double-free after stack_double As of 10574857ce167869524b97ee862b610928f6272f, it's possible to crash on a double free due to `stk_alloc` AKA `msa->stack_p` being freed twice, once at the end of match_at and a second time in `FREE_MATCH_ARG` in the parent caller. Fixes [Bug #20886] --- regexec.c | 3 +-- test/ruby/test_regexp.rb | 7 +++++++ 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/regexec.c b/regexec.c index 1039bd2ba1..8245678355 100644 --- a/regexec.c +++ b/regexec.c @@ -4217,9 +4217,8 @@ match_at(regex_t* reg, const UChar* str, const UChar* end, return ONIGERR_UNEXPECTED_BYTECODE; timeout: + STACK_SAVE; xfree(xmalloc_base); - if (stk_base != stk_alloc || IS_NOT_NULL(msa->stack_p)) - xfree(stk_base); return ONIGERR_TIMEOUT; } diff --git a/test/ruby/test_regexp.rb b/test/ruby/test_regexp.rb index 58b3081035..a4e9d7ec8e 100644 --- a/test/ruby/test_regexp.rb +++ b/test/ruby/test_regexp.rb @@ -1845,6 +1845,13 @@ class TestRegexp < Test::Unit::TestCase end end + def test_bug_20886 + re = Regexp.new("d()*+|a*a*bc", timeout: 0.02) + assert_raise(Regexp::TimeoutError) do + re === "b" + "a" * 1000 + end + end + def per_instance_redos_test(global_timeout, per_instance_timeout, expected_timeout) assert_separately([], "#{<<-"begin;"}\n#{<<-'end;'}") global_timeout = #{ EnvUtil.apply_timeout_scale(global_timeout).inspect }