From: Jeff King <peff@peff.net>
To: Martin Englund <martin@englund.nu>
Cc: Philippe Blain <levraiphilippeblain@gmail.com>, git@vger.kernel.org
Subject: Re: Git Bug Report: out of memory using git tag
Date: Tue, 1 Nov 2022 08:22:24 -0400 [thread overview]
Message-ID: <Y2EPgICMsmzKvCC8@coredump.intra.peff.net> (raw)
In-Reply-To: <CABYbkvP=fMmaFUD3bQbeQ-XKiMSP6g-u0p7Vq1Qt_K5=D5WJ+A@mail.gmail.com>
On Fri, Oct 28, 2022 at 03:29:33PM -0700, Martin Englund wrote:
> What did you do before the bug happened? (Steps to reproduce your issue)
> I created a signed tag (git tag -s) using a ssh-agent key and then ran
> git tag -l --format '%(contents:body)' v0.6.1
>
> What did you expect to happen? (Expected behavior)
> I get the output
>
> What happened instead? (Actual behavior)
> fatal: Out of memory, malloc failed (tried to allocate
> 18446744073709551266 bytes)
Thanks for the report. This looks like pointer or size_t arithmetic that
has gone negative. Here's a minimal reproduction:
{
echo subject
echo "-----BEGIN PGP SIGNATURE-----"
} | git tag -F - foo
git tag -l --format='%(contents:body)' foo
The issue isn't unique to pgp signatures; the problem is in the parsing
done by ref-filter's find_subpos(), so any signature type exhibits the
problem. At the end of that function we do:
*nonsiglen = sigstart - buf;
but "buf" has moved beyond "sigstart". Presumably because it uses
strstr() to look for end-of-line in buf. Since there isn't one before
the signature begins, we go to the end of the signature.
The bug bisects to 9f75ce3d8f (ref-filter: handle CRLF at end-of-line
more gracefully, 2020-10-29). Before then, I think our loop was careful
about moving past the start of the signature. Author cc'd.
-Peff
next prev parent reply other threads:[~2022-11-01 12:22 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-28 22:29 Git Bug Report: out of memory using git tag Martin Englund
2022-11-01 12:22 ` Jeff King [this message]
2022-11-02 0:41 ` Philippe Blain
2022-11-02 7:39 ` Jeff King
2022-11-02 7:42 ` [PATCH 1/2] ref-filter: fix parsing of signatures without blank lines Jeff King
2022-11-02 7:44 ` [PATCH 2/2] ref-filter: fix parsing of signatures with CRLF and no body Jeff King
2022-11-02 8:14 ` Git Bug Report: out of memory using git tag Elijah Newren
2022-11-02 9:13 ` gigantic commit messages, was " Jeff King
2022-11-02 14:26 ` Ævar Arnfjörð Bjarmason
2022-11-02 15:43 ` Elijah Newren
2022-11-02 8:24 ` Eric Sunshine
2022-11-02 12:13 ` Philippe Blain
2022-11-03 4:32 ` Jeff King
2022-11-03 0:42 ` Taylor Blau
2022-11-02 0:42 ` Philippe Blain
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Y2EPgICMsmzKvCC8@coredump.intra.peff.net \
--to=peff@peff.net \
--cc=git@vger.kernel.org \
--cc=levraiphilippeblain@gmail.com \
--cc=martin@englund.nu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).