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From: Teng Long <dyroneteng@gmail.com>
To: peff@peff.net
Cc: avarab@gmail.com, dyroneteng@gmail.com, git@vger.kernel.org,
	gitster@pobox.com, sunshine@sunshineco.com,
	tenglong.tl@alibaba-inc.com
Subject: Re: [PATCH v10 4/6] notes.c: introduce '[--[no-]separator|--separator=<paragraph-break>]' option
Date: Sat, 27 May 2023 15:17:21 +0800	[thread overview]
Message-ID: <20230527071721.24285-1-tenglong.tl@alibaba-inc.com> (raw)
In-Reply-To: <20230519005447.GA2955320@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

> > +static void insert_separator(struct strbuf *message, size_t pos)
> > +{
> > +	if (!separator)
> > +		return;
> > +	else if (separator[strlen(separator) - 1] == '\n')
> > +		strbuf_insertstr(message, pos, separator);
> > +	else
> > +		strbuf_insertf(message, pos, "%s%s", separator, "\n");
> > +}

> This function causes UBSan to complain on 'next' (though curiously only
> with clang, not with gcc[1]). The version in next seems to be from your
> v9, but it's largely the same except for the "if (!separator)"
> condition.
> 
> The problem is in the middle condition here. If "separator" is non-NULL,
> but is an empty string, then strlen() will return 0, and we will look at
> the out-of-bounds byte just before the string.

You definitely correct, will fix.

> This function causes UBSan to complain on 'next' (though curiously only
> with clang, not with gcc[1]). The version in next seems to be from your
> v9, but it's largely the same except for the "if (!separator)"
> condition.
> 
> The problem is in the middle condition here. If "separator" is non-NULL,
> but is an empty string, then strlen() will return 0, and we will look at
> the out-of-bounds byte just before the string.
> 
> We'd probably want something like this:
> 
> diff --git a/builtin/notes.c b/builtin/notes.c
> index 3215bce19b..a46d6dac5c 100644
> --- a/builtin/notes.c
> +++ b/builtin/notes.c
> @@ -231,7 +231,8 @@ static void write_note_data(struct note_data *d, struct object_id *oid)
>  
>  static void insert_separator(struct strbuf *message, size_t pos)
>  {
> -	if (separator[strlen(separator) - 1] == '\n')
> +	size_t sep_len = strlen(separator);
> +	if (sep_len && separator[sep_len - 1] == '\n')
>  		strbuf_addstr(message, separator);
>  	else
>  		strbuf_insertf(message, pos, "%s%s", separator, "\n");
> 
> to fix it, though I am not 100% clear on what is supposed to happen for
> an empty separator here.

It's supposed to be the same behaviour with not to specify the option, which
is the default behaviour(to use a '\n' as the separator).

The diff looks good to me, will apply.

> I was also confused that applying the fix on top of the culprit in
> 'next', 3993a53a13 (notes.c: introduce '--separator=<paragraph-break>'
> option, 2023-04-28), still leads to test failures in t3301. But I think
> that is independent of this fix. It fails even without my patch above
> (and without UBSan) in test 66, "append: specify separator with line
> break". But the failure goes away in the following patch, ad3d1f8feb
> (notes.c: append separator instead of insert by pos, 2023-04-28).

Yes, that's a problem which be taken in patch v9 4/6[1] at insert_separator(...)
, we should use strbuf_insert* api here, otherwise will always do append
but not to do insert with the position, finally break the test.

In the v9 5/6 patch[2], I tried to remove the postion to simply the logic from
insert with position to just append, and this patch cover the test case failure
in 4/6.

> I haven't been following this series enough to know what's going on, but
> you may want to figure out where the failure is coming from in
> 3993a53a13. If the change in ad3d1f8feb is merely papering over it, then
> we'd need to find and fix the true cause. If the bug is really fixed by
> ad3d1f8feb, we might want to squash those two together to avoid broken
> bisections.

Sure, we should avoid that, will fix.

> [1] To reproduce, I did:
> 
>       git checkout 3993a53a13
>       make SANITIZE=address,undefined CC=clang
>       cd t && ./t3301-notes.sh -v -i
> 
>     I'm using clang-14 on a Debian machine.

Do you always do the 'make' with 'SANITIZE=address,undefined', should I
follow that approach, may I ask you to give some advices about it?

Thanks.

[1] https://public-inbox.org/git/ed930ef4f795f30792bc14d9c1939484e4976db8.1682671758.git.dyroneteng@gmail.com/
[2] https://public-inbox.org/git/eea2246f44a3adfc4888db93975854448271032b.1682671758.git.dyroneteng@gmail.com/

  reply	other threads:[~2023-05-27  7:17 UTC|newest]

Thread overview: 186+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-13  5:56 [RFC PATCH 0/2] notes.c: introduce "--no-blankline" option Teng Long
2022-10-13  5:56 ` [RFC PATCH 1/2] " Teng Long
2022-10-13  6:06   ` Junio C Hamano
2022-10-17 13:19     ` Teng Long
2022-10-13  9:31   ` Ævar Arnfjörð Bjarmason
2022-10-17 13:33     ` Teng Long
2022-10-13  5:56 ` [RFC PATCH 2/2] notes.c: fixed tip when target and append note are both empty Teng Long
2022-10-13  9:36   ` Ævar Arnfjörð Bjarmason
2022-10-13 10:10     ` Phillip Wood
2022-10-13 10:23       ` Ævar Arnfjörð Bjarmason
2022-10-15 19:40         ` Phillip Wood
2022-10-18  3:25       ` Teng Long
2022-10-18  8:08       ` Teng Long
2022-10-18  3:11     ` Teng Long
2022-10-18  9:23       ` Ævar Arnfjörð Bjarmason
2022-11-07 13:57 ` [PATCH v2 0/3] notes.c: introduce "--blank-line" option Teng Long
2022-11-07 13:57   ` [PATCH v2 1/3] " Teng Long
2022-11-07 14:45     ` Ævar Arnfjörð Bjarmason
2022-11-07 15:45       ` Eric Sunshine
2022-11-07 17:22         ` Ævar Arnfjörð Bjarmason
2022-11-07 21:46           ` Taylor Blau
2022-11-07 22:36             ` Ævar Arnfjörð Bjarmason
2022-11-08  0:32               ` Taylor Blau
2022-11-08  3:45       ` Teng Long
2022-11-08 13:06       ` Teng Long
2022-11-08 13:22         ` Ævar Arnfjörð Bjarmason
2022-11-09  6:35           ` Teng Long
2022-11-07 15:06     ` Ævar Arnfjörð Bjarmason
2022-11-08  6:32       ` Teng Long
2022-11-07 21:47     ` Taylor Blau
2022-11-08  7:36       ` Teng Long
2022-11-07 13:57   ` [PATCH v2 2/3] notes.c: fixed tip when target and append note are both empty Teng Long
2022-11-07 14:40     ` Ævar Arnfjörð Bjarmason
2022-11-07 21:51       ` Taylor Blau
2022-11-07 22:33         ` Ævar Arnfjörð Bjarmason
2022-11-07 22:45           ` Taylor Blau
2022-11-08  8:55           ` Teng Long
2022-11-07 13:57   ` [PATCH v2 3/3] notes.c: drop unreachable code in "append_edit()" Teng Long
2022-11-07 14:41     ` Ævar Arnfjörð Bjarmason
2022-11-07 14:57   ` [PATCH v2 0/3] notes.c: introduce "--blank-line" option Ævar Arnfjörð Bjarmason
2022-11-09  7:05     ` Teng Long
2022-11-09  7:06     ` Teng Long
2022-11-09  9:06   ` [PATCH v3 0/5] notes.c: introduce "--no-blank-line" option Teng Long
2022-11-09  9:06     ` [PATCH v3 1/5] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2022-11-09  9:06     ` [PATCH v3 2/5] notes.c: cleanup for "designated init" and "char ptr init" Teng Long
2022-11-09  9:06     ` [PATCH v3 3/5] notes.c: drop unreachable code in 'append_edit()' Teng Long
2022-11-09  9:06     ` [PATCH v3 4/5] notes.c: provide tips when target and append note are both empty Teng Long
2022-11-09  9:06     ` [PATCH v3 5/5] notes.c: introduce "--no-blank-line" option Teng Long
2022-11-28 14:20     ` [PATCH v3 0/5] " Teng Long
2022-11-29  1:10       ` Junio C Hamano
2022-11-29 22:53         ` Taylor Blau
2022-11-29 12:57     ` Teng Long
2022-11-29 13:19       ` Junio C Hamano
2022-12-15 12:48         ` Teng Long
2022-12-19  3:03           ` Eric Sunshine
2022-12-21  9:16             ` Teng Long
2022-12-21 11:35               ` Junio C Hamano
2022-12-22  9:30             ` Teng Long
2022-12-23  1:36               ` Eric Sunshine
2023-01-12  2:48     ` [PATCH v4 0/5] notes.c: introduce "--separator" optio Teng Long
2023-01-12  2:48       ` [PATCH v4 1/5] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2023-01-15  4:53         ` Eric Sunshine
2023-01-28 11:22           ` Teng Long
2023-01-12  2:48       ` [PATCH v4 2/5] notes.c: cleanup for "designated init" and "char ptr init" Teng Long
2023-01-12  9:51         ` Ævar Arnfjörð Bjarmason
2023-01-28 11:33           ` Teng Long
2023-01-12  2:48       ` [PATCH v4 3/5] notes.c: drop unreachable code in 'append_edit()' Teng Long
2023-01-15 20:59         ` Eric Sunshine
2023-01-15 21:10           ` Eric Sunshine
2023-01-28 11:50           ` Teng Long
2023-01-30  5:38             ` Eric Sunshine
2023-02-01  8:08               ` Teng Long
2023-01-12  2:48       ` [PATCH v4 4/5] notes.c: provide tips when target and append note are both empty Teng Long
2023-01-12  9:52         ` Ævar Arnfjörð Bjarmason
2023-01-15 21:28         ` Eric Sunshine
2023-01-12  2:48       ` [PATCH v4 5/5] notes.c: introduce "--separator" option Teng Long
2023-01-12  9:53         ` Ævar Arnfjörð Bjarmason
2023-01-15 22:04           ` Eric Sunshine
2023-01-15 22:15         ` Eric Sunshine
2023-02-16 13:05       ` [PATCH v5 0/3] " Teng Long
2023-02-16 13:05         ` [PATCH v5 1/3] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2023-02-16 18:39           ` Junio C Hamano
2023-02-20  3:34             ` Teng Long
2023-02-16 13:05         ` [PATCH v5 2/3] notes.c: cleanup for "designated init" Teng Long
2023-02-16 18:39           ` Junio C Hamano
2023-02-16 13:05         ` [PATCH v5 3/3] notes.c: introduce "--separator" option Teng Long
2023-02-16 23:22           ` Junio C Hamano
2023-02-20 14:00             ` Teng Long
2023-02-21 21:31               ` Junio C Hamano
2023-02-22  8:17                 ` Teng Long
2023-02-22 23:15                   ` Junio C Hamano
2023-02-23  7:29         ` [PATCH v6 0/3] " Teng Long
2023-02-23  7:29           ` [PATCH v6 1/3] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2023-02-23  7:29           ` [PATCH v6 2/3] notes.c: cleanup for "designated init" Teng Long
2023-02-23  7:29           ` [PATCH v6 3/3] notes.c: introduce '--separator=<paragraph-break>' option Teng Long
2023-02-23 18:21             ` Junio C Hamano
2023-02-28 14:11               ` Teng Long
2023-02-25 21:30             ` Junio C Hamano
2023-02-28 14:14               ` Teng Long
2023-03-27 13:13           ` [PATCH v6 0/3] notes.c: introduce "--separator" option Teng Long
2023-03-28 14:28           ` [PATCH v7 0/4] " Teng Long
2023-03-28 14:28             ` [PATCH v7 1/4] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2023-03-28 14:28             ` [PATCH v7 2/4] notes.c: cleanup for "designated init" Teng Long
2023-03-29 22:17               ` Junio C Hamano
2023-03-28 14:28             ` [PATCH v7 3/4] notes.c: introduce '--separator=<paragraph-break>' option Teng Long
2023-03-28 15:37               ` Junio C Hamano
2023-03-29 14:15                 ` Teng Long
2023-03-29 21:48                   ` Junio C Hamano
2023-04-13  9:36                     ` Teng Long
2023-03-28 14:28             ` [PATCH v7 4/4] notes.c: don't do stripespace when parse file arg Teng Long
2023-03-28 15:54               ` Junio C Hamano
2023-03-29 12:06                 ` Teng Long
2023-03-29 16:21                   ` Junio C Hamano
2023-04-25 13:34             ` [PATCH 0/6] notes.c: introduce "--separator" option Teng Long
2023-04-25 13:34               ` [PATCH v8 1/6] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2023-04-25 13:34               ` [PATCH v8 2/6] notes.c: use designated initializers for clarity Teng Long
2023-04-25 13:34               ` [PATCH v8 3/6] t3321: add test cases about the notes stripspace behavior Teng Long
2023-04-25 16:25                 ` Junio C Hamano
2023-04-27  3:47                   ` Teng Long
2023-04-25 13:34               ` [PATCH v8 4/6] notes.c: introduce '--separator=<paragraph-break>' option Teng Long
2023-04-25 17:34                 ` Junio C Hamano
2023-04-27  7:21                   ` Teng Long
2023-04-27 18:21                     ` Junio C Hamano
2023-04-25 17:35                 ` Junio C Hamano
2023-04-25 13:34               ` [PATCH v8 5/6] notes.c: append separator instead of insert by pos Teng Long
2023-04-25 17:47                 ` Junio C Hamano
2023-04-27  7:51                   ` Teng Long
2023-04-25 13:34               ` [PATCH v8 6/6] notes.c: introduce "--[no-]stripspace" option Teng Long
2023-04-25 17:49                 ` Junio C Hamano
2023-04-28  7:40                   ` Teng Long
2023-04-28 18:21                     ` Junio C Hamano
2023-04-28  9:23               ` [PATCH v9 0/6] notes.c: introduce "--separator" option Teng Long
2023-04-28  9:23                 ` [PATCH v9 1/6] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2023-04-28  9:23                 ` [PATCH v9 2/6] notes.c: use designated initializers for clarity Teng Long
2023-04-28  9:23                 ` [PATCH v9 3/6] t3321: add test cases about the notes stripspace behavior Teng Long
2023-04-28  9:23                 ` [PATCH v9 4/6] notes.c: introduce '--separator=<paragraph-break>' option Teng Long
2023-04-28 20:44                   ` Junio C Hamano
2023-05-06  9:12                     ` Teng Long
2023-05-06  9:22                       ` Teng Long
2023-05-10 19:19                   ` Kristoffer Haugsbakk
2023-05-12  4:07                     ` Teng Long
2023-05-12  7:29                       ` Kristoffer Haugsbakk
2023-05-16 17:00                       ` Junio C Hamano
2023-05-17  3:58                         ` Teng Long
2023-05-17 15:32                           ` Junio C Hamano
2023-06-14  1:02                   ` Junio C Hamano
2023-06-14  1:10                     ` [PATCH] notes: do not access before the beginning of an array Junio C Hamano
2023-06-14  1:41                     ` [PATCH v9 4/6] notes.c: introduce '--separator=<paragraph-break>' option Eric Sunshine
2023-06-14  2:07                       ` Junio C Hamano
2023-06-15  7:13                         ` Jeff King
2023-06-15 19:15                           ` Junio C Hamano
2023-06-19  6:08                             ` Teng Long
2023-06-20 20:36                               ` Junio C Hamano
2023-06-21  2:50                                 ` Teng Long
2023-04-28  9:23                 ` [PATCH v9 5/6] notes.c: append separator instead of insert by pos Teng Long
2023-04-28  9:23                 ` [PATCH v9 6/6] notes.c: introduce "--[no-]stripspace" option Teng Long
2023-04-28 20:46                 ` [PATCH v9 0/6] notes.c: introduce "--separator" option Junio C Hamano
2023-05-01 22:29                 ` Junio C Hamano
2023-05-18 12:02                 ` [PATCH v10 " Teng Long
2023-05-18 12:02                   ` [PATCH v10 1/6] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2023-05-18 12:02                   ` [PATCH v10 2/6] notes.c: use designated initializers for clarity Teng Long
2023-05-18 12:02                   ` [PATCH v10 3/6] t3321: add test cases about the notes stripspace behavior Teng Long
2023-05-18 12:02                   ` [PATCH v10 4/6] notes.c: introduce '[--[no-]separator|--separator=<paragraph-break>]' option Teng Long
2023-05-18 14:34                     ` Kristoffer Haugsbakk
2023-05-20 10:41                       ` Teng Long
2023-05-20 16:12                         ` Kristoffer Haugsbakk
2023-05-19  0:54                     ` Jeff King
2023-05-27  7:17                       ` Teng Long [this message]
2023-05-27 17:19                         ` Jeff King
2023-05-29 11:48                           ` Teng Long
2023-05-18 12:02                   ` [PATCH v10 5/6] notes.c: append separator instead of insert by pos Teng Long
2023-05-18 12:02                   ` [PATCH v10 6/6] notes.c: introduce "--[no-]stripspace" option Teng Long
2023-05-18 13:56                   ` [PATCH v10 0/6] notes.c: introduce "--separator" option Kristoffer Haugsbakk
2023-05-20 10:22                     ` Teng Long
2023-05-18 15:17                   ` Junio C Hamano
2023-05-20 10:59                     ` Teng Long
2023-05-27  7:57                   ` [PATCH v11 0/7] notes.c: introduce "--separator" Teng Long
2023-05-27  7:57                     ` [PATCH v11 1/7] notes.c: cleanup 'strbuf_grow' call in 'append_edit' Teng Long
2023-05-27  7:57                     ` [PATCH v11 2/7] notes.c: use designated initializers for clarity Teng Long
2023-05-27  7:57                     ` [PATCH v11 3/7] t3321: add test cases about the notes stripspace behavior Teng Long
2023-05-27  7:57                     ` [PATCH v11 4/7] notes.c: introduce '--separator=<paragraph-break>' option Teng Long
2023-05-27  7:57                     ` [PATCH v11 5/7] notes.c: append separator instead of insert by pos Teng Long
2023-05-27  7:57                     ` [PATCH v11 6/7] notes.c: introduce "--[no-]stripspace" option Teng Long
2023-05-27  7:57                     ` [PATCH v11 7/7] notes: introduce "--no-separator" option Teng Long
2023-06-01  5:50                     ` [PATCH v11 0/7] notes.c: introduce "--separator" Junio C Hamano
2023-06-03 10:01                       ` Teng Long

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