Bug #19339: Defining ivar on special constants with @ syntax causes segv

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.7: DONTNEED, 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONE

[luke-gru (Luke Gruber)]

1.instance_eval do
  @a = 1
end

There's a missing check at the top of vm_setivar_fastpath, should be:

    if (UNLIKELY(RB_SPECIAL_CONST_P(obj))) { // example code: 1.instance_eval { @a = 1 }
        rb_check_frozen(obj); // raise FrozenError, because it's always frozen
        return Qundef;
    }

[peterzhu2118 (Peter Zhu)]

• Backport changed from 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN to 2.7: DONTNEED, 3.0: DONTNEED, 3.1: DONTNEED, 3.2: REQUIRED

Thank you for reporting this bug. I opened a PR with the fix here: https://github.com/ruby/ruby/pull/7129

[peterzhu2118 (Peter Zhu)]

• Status changed from Open to Closed

Applied in changeset git|ed6fbb79e19bf401db0e85447fee955fd10a25c7.

---

Fix crash when defining ivars on special constants

[Bug #19339]

[naruse (Yui NARUSE)]

• Backport changed from 2.7: DONTNEED, 3.0: DONTNEED, 3.1: DONTNEED, 3.2: REQUIRED to 2.7: DONTNEED, 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONE

ruby_3_2 c0df0a85dec77a09308caddb1e1efd4d38fbf7b8 merged revision(s) ed6fbb79e19bf401db0e85447fee955fd10a25c7.