bug#58042: 29.0.50; ASAN use-after-free in re_match_2_internal

[Po Lu]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Really?

Yes.

> The problem was not if it's run from within the GC, the problem was what
> this code does when *it* runs the GC (or other state-changing functions).
> [ And indeed, the fix Gerd installed was to prevent GC while running
>   pending_signals.  But I suspect this is not sufficient because there
>   are other forms of global state that can get messed up.  ]
>
> In bug#62732 we have a related problem when code run from `maybe_quit`
> (an atimer in that case) from the regexp engine, and that atimer
> itself performs a regexp-operation, which messes up the outer regexp
> engine invocation because the regexp engine is still not re-entrant (in
> that bug, the problem is the `gl_state` global variable).

bug#62732?  That's:

  29.0.60; uniquify-trailing-separator-p affects any buffer whose name
  matches a dir in CWD

I don't see how it's related to reentrant use of the regexp engine.
BTW, which atimer is it?