From: Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
To: Eli Zaretskii <eliz@gnu.org>
Cc: gerd.moellmann@gmail.com, 56108@debbugs.gnu.org
Subject: bug#56108: 29.0.50; ASAN use-after-free in re_match_2_internal
Date: Thu, 23 Jun 2022 17:29:13 -0400 [thread overview]
Message-ID: <jwvedzfoz1i.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <831qvfg876.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 23 Jun 2022 10:17:17 +0300")
> Stefan, do you happen to know why some of the callers of
> compile_pattern don't call freeze_pattern to protect the new cache
> entry? Is it just an omission or do we miss something here?
Before `freeze_pattern`, the design was that nothing could happen while
running the regexp matcher (no GC, no execution of Lisp code).
Commit 938d252d1c6c5e2027aa250c649deb024154f936 changed that so that
searching inside a *buffer* could end up running ELisp code (and hence
also GC). AFAIK this still can't happen when searching in strings.
[ IIRC The need to run ELisp is so as to apply `syntax-table` text
properties on demand via `syntax-propertize`. ]
So I think freeze_pattern should be used in all cases where
`compile_pattern` is used to search inside a buffer, but it shouldn't be
necessary when searching within a string.
At least, that's my recollection.
Stefan
next prev parent reply other threads:[~2022-06-23 21:29 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-20 14:07 bug#56108: 29.0.50; ASAN use-after-free in re_match_2_internal Gerd Möllmann
2022-06-20 19:09 ` Eli Zaretskii
2022-06-22 8:13 ` Gerd Möllmann
2022-06-22 13:38 ` Eli Zaretskii
2022-06-22 14:10 ` Gerd Möllmann
2022-06-22 14:24 ` Eli Zaretskii
2022-06-22 15:11 ` Gerd Möllmann
2022-06-22 16:19 ` Eli Zaretskii
2022-06-23 5:53 ` Gerd Möllmann
2022-06-23 6:57 ` Eli Zaretskii
2022-06-23 7:17 ` Eli Zaretskii
2022-06-23 21:29 ` Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors [this message]
2022-06-24 5:55 ` Eli Zaretskii
2022-06-24 6:01 ` Gerd Möllmann
2022-06-24 9:35 ` Gerd Möllmann
2022-06-24 15:40 ` Eli Zaretskii
2022-06-25 9:18 ` Eli Zaretskii
2022-06-27 13:26 ` Eli Zaretskii
2022-06-27 13:29 ` Gerd Möllmann
2022-06-23 8:24 ` Gerd Möllmann
2022-06-23 8:37 ` Eli Zaretskii
2022-06-23 8:49 ` Gerd Möllmann
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