git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Jeff King <peff@peff.net>
To: Junio C Hamano <gitster@pobox.com>,
	git@vger.kernel.org, stolee@gmail.com, avarab@gmail.com
Subject: Re: [PATCH v3 2/3] commit-graph: fix buffer read-overflow
Date: Tue, 11 Dec 2018 04:50:02 -0500	[thread overview]
Message-ID: <20181211095002.GB31588@sigill.intra.peff.net> (raw)
In-Reply-To: <20181210215649.GC37614@google.com>

On Mon, Dec 10, 2018 at 01:56:49PM -0800, Josh Steadmon wrote:

> > "stat(1)" is not so portable, so you'll get complaints from minority
> > platform users later.  So is "truncate(1)".
> 
> Ack, thanks for the catch. I have a workaround for stat in the form of
> "wc -c", and for truncate with a combination of dd and /dev/zero.
> However, I'm finding conflicting information about whether or not
> /dev/zero exists on macOS. At the least, it sounds like it might not
> work on very old versions. Would this be acceptable, or should I add a
> new test function to do this?

If you're just interested in truncation (and not a bunch of zero bytes),
you can dd from /dev/null.

Another way to truncate is to move the file elsewhere, and then copy
only some of the bytes back (see t1450's "fsck detects truncated loose
object").

-Peff

  reply	other threads:[~2018-12-11  9:50 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-05 22:32 [PATCH 0/2] Add commit-graph fuzzer and fix buffer overflow Josh Steadmon
2018-12-05 22:32 ` [PATCH 1/2] commit-graph, fuzz: Add fuzzer for commit-graph Josh Steadmon
2018-12-05 22:48   ` Ævar Arnfjörð Bjarmason
2018-12-06  1:00     ` Josh Steadmon
2018-12-06  1:32   ` Junio C Hamano
2018-12-06  1:41     ` Junio C Hamano
2018-12-06  4:47   ` Junio C Hamano
2018-12-05 22:32 ` [PATCH 2/2] commit-graph: fix buffer read-overflow Josh Steadmon
2018-12-06 13:11   ` Derrick Stolee
2018-12-06 20:20 ` [PATCH v2 0/3] Add commit-graph fuzzer and fix buffer overflow Josh Steadmon
2018-12-06 20:20   ` [PATCH v2 1/3] commit-graph, fuzz: Add fuzzer for commit-graph Josh Steadmon
2018-12-06 20:20   ` [PATCH v2 2/3] commit-graph: fix buffer read-overflow Josh Steadmon
2018-12-07  9:07     ` Jeff King
2018-12-07 13:33     ` Derrick Stolee
2018-12-06 20:20   ` [PATCH v2 3/3] Makefile: correct example fuzz build Josh Steadmon
2018-12-07 22:27   ` [PATCH v3 0/3] Add commit-graph fuzzer and fix buffer overflow Josh Steadmon
2018-12-07 22:27     ` [PATCH v3 1/3] commit-graph, fuzz: Add fuzzer for commit-graph Josh Steadmon
2018-12-07 22:27     ` [PATCH v3 2/3] commit-graph: fix buffer read-overflow Josh Steadmon
2018-12-09  4:01       ` Junio C Hamano
2018-12-10  4:28         ` SZEDER Gábor
2018-12-10 21:58           ` Josh Steadmon
2018-12-10 21:56         ` Josh Steadmon
2018-12-11  9:50           ` Jeff King [this message]
2018-12-07 22:27     ` [PATCH v3 3/3] Makefile: correct example fuzz build Josh Steadmon
2018-12-13 19:43 ` [PATCH v4 0/3] Add commit-graph fuzzer and fix buffer overflow Josh Steadmon
2018-12-13 19:43   ` [PATCH v4 1/3] commit-graph, fuzz: Add fuzzer for commit-graph Josh Steadmon
2018-12-13 19:43   ` [PATCH v4 2/3] commit-graph: fix buffer read-overflow Josh Steadmon
2019-01-12 10:57     ` SZEDER Gábor
2019-01-15 19:58       ` Josh Steadmon
2018-12-13 19:43   ` [PATCH v4 3/3] Makefile: correct example fuzz build Josh Steadmon
2018-12-18 17:35   ` [PATCH v4 0/3] Add commit-graph fuzzer and fix buffer overflow Jeff King
2018-12-18 21:05     ` Josh Steadmon
2018-12-19 15:51       ` Jeff King
2018-12-20 19:35         ` Johannes Schindelin
2018-12-20 20:11           ` Jeff King
2018-12-26 22:29         ` Junio C Hamano
2019-01-15 19:59 ` [PATCH v5 " Josh Steadmon
2019-01-15 19:59   ` [PATCH v5 1/3] commit-graph, fuzz: Add fuzzer for commit-graph Josh Steadmon
2019-01-15 20:33     ` Junio C Hamano
2019-01-15 19:59   ` [PATCH v5 2/3] commit-graph: fix buffer read-overflow Josh Steadmon
2019-01-15 19:59   ` [PATCH v5 3/3] Makefile: correct example fuzz build Josh Steadmon
2019-01-15 20:39     ` Junio C Hamano
2019-01-15 21:59       ` Josh Steadmon
2019-01-15 22:34         ` Junio C Hamano
2019-01-15 22:25 ` [PATCH v6 0/3] Add commit-graph fuzzer and fix buffer overflow Josh Steadmon
2019-01-15 22:25   ` [PATCH v6 1/3] commit-graph, fuzz: Add fuzzer for commit-graph Josh Steadmon
2019-01-15 22:25   ` [PATCH v6 2/3] commit-graph: fix buffer read-overflow Josh Steadmon
2019-02-20 14:55     ` Ævar Arnfjörð Bjarmason
2019-02-20 16:50       ` SZEDER Gábor
2019-01-15 22:25   ` [PATCH v6 3/3] Makefile: correct example fuzz build Josh Steadmon

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=20181211095002.GB31588@sigill.intra.peff.net \
    --to=peff@peff.net \
    --cc=avarab@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=stolee@gmail.com \
    /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).