Git Mailing List Archive on lore.kernel.org
 help / color / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Olga Telezhnaya" <olyatelezhnaya@gmail.com>,
	git@vger.kernel.org, "Taylor Blau" <me@ttaylorr.com>,
	"Elijah Newren" <newren@gmail.com>,
	"Johannes Schindelin" <Johannes.Schindelin@gmx.de>
Subject: Re: [PATCH] ref-filter: fix NULL check for parse object failure
Date: Thu, 01 Apr 2021 12:52:31 -0700
Message-ID: <xmqqh7kp3hq8.fsf@gitster.g> (raw)
In-Reply-To: <YGWFGMdGcKeaqCQF@coredump.intra.peff.net> (Jeff King's message of "Thu, 1 Apr 2021 04:32:24 -0400")

Jeff King <peff@peff.net> writes:

> Here's a patch to fix it. This is mostly orthogonal to your patch
> series. It happens to use a similar recipe to reproduce, but that is not
> the only way to do it, and the fix and the test shouldn't conflict
> textually or semantically.
>
> -- >8 --
> Subject: [PATCH] ref-filter: fix NULL check for parse object failure
>
> After we run parse_object_buffer() to get an object's contents, we try
> to check that the return value wasn't NULL. However, since our "struct
> object" is a pointer-to-pointer, and we assign like:
>
>   *obj = parse_object_buffer(...);
>
> it's not correct to check:
>
>   if (!obj)
>
> That will always be true, since our double pointer will continue to
> point to the single pointer (which is itself NULL). This is a regression
> that was introduced by aa46a0da30 (ref-filter: use oid_object_info() to
> get object, 2018-07-17); since that commit we'll segfault on a parse
> failure, as we try to look at the NULL object pointer.
>
> There are many ways a parse could fail, but most of them are hard to set
> up in the tests (it's easy to make a bogus object, but update-ref will
> refuse to point to it). The test here uses a tag which points to a wrong
> object type. A parse of just the broken tag object will succeed, but
> seeing both tag objects in the same process will lead to a parse error
> (since we'll see the pointed-to object as both types).
>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
>  ref-filter.c            |  2 +-
>  t/t6300-for-each-ref.sh | 10 ++++++++++
>  2 files changed, 11 insertions(+), 1 deletion(-)

Makes sense.  Will queue.

> diff --git a/ref-filter.c b/ref-filter.c
> index f0bd32f714..a0adb4551d 100644
> --- a/ref-filter.c
> +++ b/ref-filter.c
> @@ -1608,7 +1608,7 @@ static int get_object(struct ref_array_item *ref, int deref, struct object **obj
>  
>  	if (oi->info.contentp) {
>  		*obj = parse_object_buffer(the_repository, &oi->oid, oi->type, oi->size, oi->content, &eaten);
> -		if (!obj) {
> +		if (!*obj) {
>  			if (!eaten)
>  				free(oi->content);
>  			return strbuf_addf_ret(err, -1, _("parse_object_buffer failed on %s for %s"),
> diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
> index cac7f443d0..2e7c32d50c 100755
> --- a/t/t6300-for-each-ref.sh
> +++ b/t/t6300-for-each-ref.sh
> @@ -1134,4 +1134,14 @@ test_expect_success 'for-each-ref --ignore-case works on multiple sort keys' '
>  	test_cmp expect actual
>  '
>  
> +test_expect_success 'for-each-ref reports broken tags' '
> +	git tag -m "good tag" broken-tag-good HEAD &&
> +	git cat-file tag broken-tag-good >good &&
> +	sed s/commit/blob/ <good >bad &&
> +	bad=$(git hash-object -w -t tag bad) &&
> +	git update-ref refs/tags/broken-tag-bad $bad &&
> +	test_must_fail git for-each-ref --format="%(*objectname)" \
> +		refs/tags/broken-tag-*
> +'
> +
>  test_done

  parent reply index

Thread overview: 142+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-06-22  0:33 [PATCH 0/2] Pull objects of various types Daniel Barkalow
2005-06-22  0:35 ` [PATCH 1/2] Parse tags for absent objects Daniel Barkalow
2021-03-08 20:04   ` [PATCH 0/7] improve reporting of unexpected objects Ævar Arnfjörð Bjarmason
2021-03-28  2:13     ` [PATCH v2 00/10] " Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 01/10] object.c: stop supporting len == -1 in type_from_string_gently() Ævar Arnfjörð Bjarmason
2021-03-28  5:35         ` Junio C Hamano
2021-03-28 15:46           ` Ævar Arnfjörð Bjarmason
2021-03-28 18:25             ` Junio C Hamano
2021-04-22 18:09               ` Felipe Contreras
2021-03-28  2:13       ` [PATCH v2 02/10] object.c: refactor type_from_string_gently() Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 03/10] object.c: make type_from_string() return "enum object_type" Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 04/10] object-file.c: make oid_object_info() " Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 05/10] object-name.c: make dependency on object_type order more obvious Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 06/10] tree.c: fix misindentation in parse_tree_gently() Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 07/10] object.c: add a utility function for "expected type X, got Y" Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 08/10] object.c: add and use oid_is_type_or_die_msg() function Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 09/10] object tests: add test for unexpected objects in tags Ævar Arnfjörð Bjarmason
2021-03-28  2:13       ` [PATCH v2 10/10] tag: don't misreport type of tagged objects in errors Ævar Arnfjörð Bjarmason
2021-03-30  5:50         ` Junio C Hamano
2021-03-31 11:02           ` Jeff King
2021-03-31 18:05             ` Junio C Hamano
2021-03-31 18:31             ` Ævar Arnfjörð Bjarmason
2021-03-31 18:59               ` Jeff King
2021-03-31 20:46                 ` Ævar Arnfjörð Bjarmason
2021-04-01  7:54                   ` Jeff King
2021-04-01  8:32                     ` [PATCH] ref-filter: fix NULL check for parse object failure Jeff King
2021-04-01 13:56                       ` [PATCH v2 0/5] mktag tests & fix for-each-ref segfault Ævar Arnfjörð Bjarmason
2021-04-01 13:56                         ` [PATCH v2 1/5] mktag tests: parse out options in helper Ævar Arnfjörð Bjarmason
2021-04-01 13:56                         ` [PATCH v2 2/5] mktag tests: invert --no-strict test Ævar Arnfjörð Bjarmason
2021-04-01 13:56                         ` [PATCH v2 3/5] mktag tests: do fsck on failure Ævar Arnfjörð Bjarmason
2021-04-01 13:56                         ` [PATCH v2 4/5] mktag tests: test for maybe segfaulting for-each-ref Ævar Arnfjörð Bjarmason
2021-04-01 13:56                         ` [PATCH v2 5/5] ref-filter: fix NULL check for parse object failure Ævar Arnfjörð Bjarmason
2021-04-01 19:19                           ` Ramsay Jones
2021-04-01 19:56                         ` [PATCH v2 0/5] mktag tests & fix for-each-ref segfault Junio C Hamano
2021-04-02 11:37                           ` Ævar Arnfjörð Bjarmason
2021-04-02 20:51                             ` Junio C Hamano
2021-04-01 19:52                       ` Junio C Hamano [this message]
2021-03-31 18:41             ` [PATCH v2 10/10] tag: don't misreport type of tagged objects in errors Junio C Hamano
2021-03-31 19:00               ` Jeff King
2021-03-28  9:27       ` [PATCH v2 00/10] improve reporting of unexpected objects Jeff King
2021-03-29 13:34         ` Ævar Arnfjörð Bjarmason
2021-03-31 10:43           ` Jeff King
2021-04-09  8:07       ` [PATCH 0/2] blob/object.c: trivial readability improvements Ævar Arnfjörð Bjarmason
2021-04-09  8:07         ` [PATCH 1/2] blob.c: remove buffer & size arguments to parse_blob_buffer() Ævar Arnfjörð Bjarmason
2021-04-09 17:51           ` Jeff King
2021-04-09 22:31             ` Junio C Hamano
2021-04-10 12:57             ` Ævar Arnfjörð Bjarmason
2021-04-10 13:01               ` Ævar Arnfjörð Bjarmason
2021-04-13  8:25               ` Jeff King
2021-04-09  8:07         ` [PATCH 2/2] object.c: initialize automatic variable in lookup_object() Ævar Arnfjörð Bjarmason
2021-04-09 17:53           ` Jeff King
2021-04-09 22:32             ` Junio C Hamano
2021-04-09  8:32         ` [PATCH 0/6] {tag,object}*.c: refactorings + prep for a larger change Ævar Arnfjörð Bjarmason
2021-04-09  8:32           ` [PATCH 1/6] object.c: stop supporting len == -1 in type_from_string_gently() Ævar Arnfjörð Bjarmason
2021-04-09 18:06             ` Jeff King
2021-04-09 18:10               ` Jeff King
2021-04-09  8:32           ` [PATCH 2/6] object.c: remove "gently" argument to type_from_string_gently() Ævar Arnfjörð Bjarmason
2021-04-09 18:10             ` Jeff King
2021-04-09  8:32           ` [PATCH 3/6] object.c: make type_from_string() return "enum object_type" Ævar Arnfjörð Bjarmason
2021-04-09 18:14             ` Jeff King
2021-04-09 19:42               ` Ævar Arnfjörð Bjarmason
2021-04-09 21:29                 ` Jeff King
2021-04-09  8:32           ` [PATCH 4/6] object-file.c: make oid_object_info() " Ævar Arnfjörð Bjarmason
2021-04-09 18:24             ` Jeff King
2021-04-09  8:32           ` [PATCH 5/6] object-name.c: make dependency on object_type order more obvious Ævar Arnfjörð Bjarmason
2021-04-09 18:36             ` Jeff King
2021-04-09  8:32           ` [PATCH 6/6] tag.c: use type_from_string_gently() when parsing tags Ævar Arnfjörð Bjarmason
2021-04-09 18:42             ` Jeff King
2021-04-09  8:49           ` [PATCH 0/7] object.c: add and use "is expected" utility function + object_as_type() use Ævar Arnfjörð Bjarmason
2021-04-09  8:49             ` [PATCH 1/7] tree.c: fix misindentation in parse_tree_gently() Ævar Arnfjörð Bjarmason
2021-04-09  8:49             ` [PATCH 2/7] object.c: add a utility function for "expected type X, got Y" Ævar Arnfjörð Bjarmason
2021-04-09  8:49             ` [PATCH 3/7] object.c: add and use oid_is_type_or_die_msg() function Ævar Arnfjörð Bjarmason
2021-04-09  8:49             ` [PATCH 4/7] commit-graph: use obj->type, not object_as_type() Ævar Arnfjörð Bjarmason
2021-04-09  8:50             ` [PATCH 5/7] commit.c: don't use deref_tag() -> object_as_type() Ævar Arnfjörð Bjarmason
2021-04-09  8:50             ` [PATCH 6/7] object.c: normalize brace style in object_as_type() Ævar Arnfjörð Bjarmason
2021-04-09  8:50             ` [PATCH 7/7] object.c: remove "quiet" parameter from object_as_type() Ævar Arnfjörð Bjarmason
2021-04-20 13:36             ` [PATCH v2 0/8] object.c: add and use "is expected" utility function + object_as_type() use Ævar Arnfjörð Bjarmason
2021-04-20 13:36               ` [PATCH v2 1/8] tree.c: fix misindentation in parse_tree_gently() Ævar Arnfjörð Bjarmason
2021-04-20 13:36               ` [PATCH v2 2/8] object.c: add a utility function for "expected type X, got Y" Ævar Arnfjörð Bjarmason
2021-04-21 22:02                 ` Jonathan Tan
2021-04-22  6:10                   ` Ævar Arnfjörð Bjarmason
2021-04-20 13:36               ` [PATCH v2 3/8] object.c: add and use oid_is_type_or_die_msg() function Ævar Arnfjörð Bjarmason
2021-04-21 22:07                 ` Jonathan Tan
2021-04-21 23:28                 ` Josh Steadmon
2021-04-28  4:12                   ` Junio C Hamano
2021-04-20 13:36               ` [PATCH v2 4/8] commit-graph: use obj->type, not object_as_type() Ævar Arnfjörð Bjarmason
2021-04-20 13:36               ` [PATCH v2 5/8] branch tests: assert lookup_commit_reference_gently() error Ævar Arnfjörð Bjarmason
2021-04-20 13:36               ` [PATCH v2 6/8] commit.c: don't use deref_tag() -> object_as_type() Ævar Arnfjörð Bjarmason
2021-04-21 22:26                 ` Jonathan Tan
2021-04-20 13:36               ` [PATCH v2 7/8] object.c: normalize brace style in object_as_type() Ævar Arnfjörð Bjarmason
2021-04-20 13:37               ` [PATCH v2 8/8] object.c: remove "quiet" parameter from object_as_type() Ævar Arnfjörð Bjarmason
2021-04-20 13:00           ` [PATCH v2 00/10] {tag,object}*.c: refactorings + prep for a larger change Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 01/10] object.c: stop supporting len == -1 in type_from_string_gently() Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 02/10] object.c: remove "gently" argument to type_from_string_gently() Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 03/10] object.c: make type_from_string() return "enum object_type" Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 04/10] object-file.c: make oid_object_info() " Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 05/10] object-name.c: make dependency on object_type order more obvious Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 06/10] tag.c: use type_from_string_gently() when parsing tags Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 07/10] hash-object: pass along type length to object.c Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 08/10] hash-object: refactor nested else/if/if into else if/else if Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 09/10] hash-object: show usage on invalid --type Ævar Arnfjörð Bjarmason
2021-04-20 13:00             ` [PATCH v2 10/10] object.c: move type_from_string() code to its last user Ævar Arnfjörð Bjarmason
2021-04-20 12:50         ` [PATCH v2 00/10] object.c et al: tests, small bug fixes etc Ævar Arnfjörð Bjarmason
2021-04-20 12:50           ` [PATCH v2 01/10] cat-file tests: test for bogus type name handling Ævar Arnfjörð Bjarmason
2021-04-29  4:15             ` Junio C Hamano
2021-04-20 12:50           ` [PATCH v2 02/10] hash-object tests: more detailed test for invalid type Ævar Arnfjörð Bjarmason
2021-04-20 12:50           ` [PATCH v2 03/10] mktree tests: add test for invalid object type Ævar Arnfjörð Bjarmason
2021-04-20 12:50           ` [PATCH v2 04/10] object-file.c: take type id, not string, in read_object_with_reference() Ævar Arnfjörð Bjarmason
2021-04-29  4:37             ` Junio C Hamano
2021-04-20 12:50           ` [PATCH v2 05/10] {commit,tree,blob,tag}.c: add a create_{commit,tree,blob,tag}() Ævar Arnfjörð Bjarmason
2021-04-29  4:45             ` Junio C Hamano
2021-04-29 12:01               ` Ævar Arnfjörð Bjarmason
2021-04-20 12:50           ` [PATCH v2 06/10] blob.c: remove parse_blob_buffer() Ævar Arnfjörð Bjarmason
2021-04-29  4:51             ` Junio C Hamano
2021-04-20 12:50           ` [PATCH v2 07/10] object.c: simplify return semantic of parse_object_buffer() Ævar Arnfjörð Bjarmason
2021-04-20 12:50           ` [PATCH v2 08/10] object.c: don't go past "len" under die() in type_from_string_gently() Ævar Arnfjörð Bjarmason
2021-04-29  4:55             ` Junio C Hamano
2021-04-20 12:50           ` [PATCH v2 09/10] mktree: stop setting *ntr++ to NIL Ævar Arnfjörð Bjarmason
2021-04-29  5:01             ` Junio C Hamano
2021-04-20 12:50           ` [PATCH v2 10/10] mktree: emit a more detailed error when the <type> is invalid Ævar Arnfjörð Bjarmason
2021-03-08 20:04   ` [PATCH 1/7] object.c: refactor type_from_string_gently() Ævar Arnfjörð Bjarmason
2021-03-08 20:52     ` Taylor Blau
2021-03-09 10:46     ` Jeff King
2021-03-08 20:04   ` [PATCH 2/7] object.c: make type_from_string() return "enum object_type" Ævar Arnfjörð Bjarmason
2021-03-08 20:56     ` Taylor Blau
2021-03-08 21:48     ` Junio C Hamano
2021-03-08 20:04   ` [PATCH 3/7] oid_object_info(): " Ævar Arnfjörð Bjarmason
2021-03-08 21:54     ` Junio C Hamano
2021-03-08 22:32       ` Junio C Hamano
2021-03-09 10:34     ` Jeff King
2021-03-08 20:04   ` [PATCH 4/7] tree.c: fix misindentation in parse_tree_gently() Ævar Arnfjörð Bjarmason
2021-03-08 20:04   ` [PATCH 5/7] object.c: add a utility function for "expected type X, got Y" Ævar Arnfjörð Bjarmason
2021-03-08 20:59     ` Taylor Blau
2021-03-08 22:15     ` Junio C Hamano
2021-03-08 20:04   ` [PATCH 6/7] object tests: add test for unexpected objects in tags Ævar Arnfjörð Bjarmason
2021-03-09 10:44     ` Jeff King
2021-03-28  1:35       ` Ævar Arnfjörð Bjarmason
2021-03-28  9:06         ` Jeff King
2021-03-28 15:39           ` Ævar Arnfjörð Bjarmason
2021-03-29  9:16             ` Jeff King
2021-03-08 20:04   ` [PATCH 7/7] tag: don't misreport type of tagged objects in errors Ævar Arnfjörð Bjarmason
2005-06-22  0:35 ` [PATCH 2/2] Pull misc objects Daniel Barkalow

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=xmqqh7kp3hq8.fsf@gitster.g \
    --to=gitster@pobox.com \
    --cc=Johannes.Schindelin@gmx.de \
    --cc=avarab@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=me@ttaylorr.com \
    --cc=newren@gmail.com \
    --cc=olyatelezhnaya@gmail.com \
    --cc=peff@peff.net \
    /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

Git Mailing List Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/git/0 git/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 git git/ https://lore.kernel.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.git


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git