public inbox for git@vger.kernel.org 
 help / color / mirror / Atom feed

From: Taylor Blau <me@ttaylorr•com>
To: Derrick Stolee via GitGitGadget <gitgitgadget@gmail•com>
Cc: git@vger•kernel.org, gitster@pobox•com,
	Derrick Stolee <derrickstolee@github•com>
Subject: Re: [PATCH 2/4] fsck: check rev-index checksums
Date: Mon, 17 Apr 2023 18:24:35 -0400	[thread overview]
Message-ID: <ZD3HI/LIXVv6Pacn@nand.local> (raw)
In-Reply-To: <7db4ec3e327ed3695f4f5409cb2dc80c72688758.1681748502.git.gitgitgadget@gmail.com>

On Mon, Apr 17, 2023 at 04:21:39PM +0000, Derrick Stolee via GitGitGadget wrote:
> @@ -309,6 +310,15 @@ int load_pack_revindex(struct repository *r, struct packed_git *p)
>   */
>  int verify_pack_revindex(struct packed_git *p)
>  {
> +	/* Do not bother checking if not initialized. */

Yep, makes sense; if we don't have an on-disk reverse index (which is
mmap'd into `revindex_map` we don't have anything to verify), so we can
bail here.

> +	if (!p->revindex_map)
> +		return 0;
> +
> +	if (!hashfile_checksum_valid((const unsigned char *)p->revindex_map, p->revindex_size)) {
> +		error(_("invalid checksum"));
> +		return -1;
> +	}
> +
>  	return 0;
>  }
>
> diff --git a/t/t5325-reverse-index.sh b/t/t5325-reverse-index.sh
> index 206c412f50b..6b7c709a1f6 100755
> --- a/t/t5325-reverse-index.sh
> +++ b/t/t5325-reverse-index.sh
> @@ -145,4 +145,44 @@ test_expect_success 'fsck succeeds on good rev-index' '
>  	)
>  '
>
> +test_expect_success 'set up rev-index corruption tests' '

s/set up/setup for easy `--run`-ing (e.g., ./t5325-*.sh --run=setup,fsck).

> +	git init corrupt &&
> +	(
> +		cd corrupt &&
> +
> +		test_commit commit &&
> +		git -c pack.writeReverseIndex=true repack -ad &&
> +
> +		revfile=$(ls .git/objects/pack/pack-*.rev) &&
> +		chmod a+w $revfile &&
> +		cp $revfile $revfile.bak
> +	)
> +'
> +
> +corrupt_rev_and_verify () {
> +	(
> +		pos="$1" &&
> +		value="$2" &&
> +		error="$3" &&
> +
> +		cd corrupt &&
> +		revfile=$(ls .git/objects/pack/pack-*.rev) &&
> +
> +		# Reset to original rev-file.
> +		cp $revfile.bak $revfile &&
> +
> +		printf "$value" | dd of=$revfile bs=1 seek="$pos" conv=notrunc &&
> +		test_must_fail git fsck 2>err &&
> +		grep "$error" err
> +	)
> +}
> +
> +test_expect_success 'fsck catches invalid checksum' '
> +	revfile=$(ls corrupt/.git/objects/pack/pack-*.rev) &&

Would this test be tighter if we introduced a sub-shell and cd'd into
"corrupt" here?

> +	orig_size=$(wc -c <$revfile) &&

I'm nitpicking, but we may want to use `test_file_size` here instead of
`wc -c`. The latter outnumbers the former in terms of number of uses,
but I think we consider `test_file_size` to be canonical these days.

> +	hashpos=$((orig_size - 10)) &&
> +	corrupt_rev_and_verify $hashpos bogus \
> +		"invalid checksum"
> +'

This looks good.

Thanks,
Taylor

next prev parent reply	other threads:[~2023-04-17 22:24 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-17 16:21 [PATCH 0/4] git fsck: check pack rev-index files Derrick Stolee via GitGitGadget
2023-04-17 16:21 ` [PATCH 1/4] fsck: create scaffolding for rev-index checks Derrick Stolee via GitGitGadget
2023-04-17 22:20   ` Taylor Blau
2023-04-17 16:21 ` [PATCH 2/4] fsck: check rev-index checksums Derrick Stolee via GitGitGadget
2023-04-17 22:15   ` Junio C Hamano
2023-04-18 14:24     ` Derrick Stolee
2023-04-17 22:24   ` Taylor Blau [this message]
2023-04-18 14:27     ` Derrick Stolee
2023-04-18 14:51       ` Taylor Blau
2023-04-18 14:57         ` Derrick Stolee
2023-04-18 15:03           ` Taylor Blau
2023-04-17 16:21 ` [PATCH 3/4] fsck: check rev-index position values Derrick Stolee via GitGitGadget
2023-04-17 22:01   ` Junio C Hamano
2023-04-18 14:32     ` Derrick Stolee
2023-04-17 22:52   ` Taylor Blau
2023-04-17 16:21 ` [PATCH 4/4] fsck: validate .rev file header Derrick Stolee via GitGitGadget
2023-04-17 21:37 ` [PATCH 0/4] git fsck: check pack rev-index files Junio C Hamano
2023-04-18 15:23 ` Taylor Blau
2023-04-18 16:59   ` Junio C Hamano

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

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=ZD3HI/LIXVv6Pacn@nand.local \
    --to=me@ttaylorr$(echo .)com \
    --cc=derrickstolee@github$(echo .)com \
    --cc=git@vger$(echo .)kernel.org \
    --cc=gitgitgadget@gmail$(echo .)com \
    --cc=gitster@pobox$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox