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From: "Martin Ågren" <martin.agren@gmail.com>
To: Jeff King <peff@peff.net>
Cc: Taylor Blau <me@ttaylorr.com>,
	Git Mailing List <git@vger.kernel.org>,
	Derrick Stolee <dstolee@microsoft.com>,
	Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH 03/23] pack-bitmap: bounds-check size of cache extension
Date: Fri, 13 Nov 2020 06:26:02 +0100	[thread overview]
Message-ID: <CAN0heSpQURCY4xnLHzq8ok7as-YUq4VingPrZ-NJnetsv-RG1w@mail.gmail.com> (raw)
In-Reply-To: <20201113045700.GA743619@coredump.intra.peff.net>

On Fri, 13 Nov 2020 at 05:57, Jeff King <peff@peff.net> wrote:
>
> On Thu, Nov 12, 2020 at 06:47:09PM +0100, Martin Ågren wrote:
>
> > > +               uint32_t cache_size = st_mult(index->pack->num_objects, sizeof(uint32_t));
> >
> > Hmm. If `sizeof(size_t)` is 8, then this multiplication can't possibly
> > overflow. A huge value of `num_objects` (say, 0xffffffff) would give a
> > huge return value (0xffffffff<<2) which would be truncated (0xfffffffc).
> > I think?
>
> Yeah, `cache_size` should absolutely be a `size_t`. If you have more
> than a billion objects, obviously your cache is going to be bigger than
> that. But most importantly, somebody can _claim_ to have a huge number
> of objects and foil the size checks by wrapping around.
>
> > Do we want a `u32_mult()`?
>
> Nah, we should be doing this as a size_t in the first place. There are
> similar problems with the .idx format, btw. I have a series to deal with
> that which I've been meaning to post.

Yes, that makes sense!

> >   if (cache_size > index_end - index->map - header_size)
>
> Yes, I agree this should be done as a subtraction as you showed to avoid
> integer overflow.

> >   -       if (index->map_size < sizeof(*header) + the_hash_algo->rawsz)
> >   +       if (index->map_size < header_size + the_hash_algo->rawsz)

> Right. I think that's right, and the previous patch is just buggy.

Martin

  reply	other threads:[~2020-11-13  5:26 UTC|newest]

Thread overview: 173+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-11 19:41 [PATCH 00/23] pack-bitmap: bitmap generation improvements Taylor Blau
2020-11-11 19:41 ` [PATCH 01/23] ewah/ewah_bitmap.c: grow buffer past 1 Taylor Blau
2020-11-22 19:36   ` Junio C Hamano
2020-11-23 16:22     ` Taylor Blau
2020-11-24  2:48       ` Jeff King
2020-11-24  2:51         ` Jeff King
2020-12-01 22:56           ` Taylor Blau
2020-11-11 19:41 ` [PATCH 02/23] pack-bitmap: fix header size check Taylor Blau
2020-11-12 17:39   ` Martin Ågren
2020-11-11 19:42 ` [PATCH 03/23] pack-bitmap: bounds-check size of cache extension Taylor Blau
2020-11-12 17:47   ` Martin Ågren
2020-11-13  4:57     ` Jeff King
2020-11-13  5:26       ` Martin Ågren [this message]
2020-11-13 21:29       ` Taylor Blau
2020-11-13 21:39         ` Jeff King
2020-11-13 21:49           ` Taylor Blau
2020-11-13 22:11             ` Jeff King
2020-11-11 19:42 ` [PATCH 04/23] t5310: drop size of truncated ewah bitmap Taylor Blau
2020-11-11 19:42 ` [PATCH 05/23] rev-list: die when --test-bitmap detects a mismatch Taylor Blau
2020-11-11 19:42 ` [PATCH 06/23] ewah: factor out bitmap growth Taylor Blau
2020-11-11 19:42 ` [PATCH 07/23] ewah: make bitmap growth less aggressive Taylor Blau
2020-11-22 20:32   ` Junio C Hamano
2020-11-23 16:49     ` Taylor Blau
2020-11-24  3:00       ` Jeff King
2020-11-24 20:11         ` Junio C Hamano
2020-11-11 19:43 ` [PATCH 08/23] ewah: implement bitmap_or() Taylor Blau
2020-11-22 20:34   ` Junio C Hamano
2020-11-23 16:52     ` Taylor Blau
2020-11-11 19:43 ` [PATCH 09/23] ewah: add bitmap_dup() function Taylor Blau
2020-11-11 19:43 ` [PATCH 10/23] pack-bitmap-write: reimplement bitmap writing Taylor Blau
2020-11-11 19:43 ` [PATCH 11/23] pack-bitmap-write: pass ownership of intermediate bitmaps Taylor Blau
2020-11-11 19:43 ` [PATCH 12/23] pack-bitmap-write: fill bitmap with commit history Taylor Blau
2020-11-11 19:43 ` [PATCH 13/23] bitmap: add bitmap_diff_nonzero() Taylor Blau
2020-11-11 19:43 ` [PATCH 14/23] commit: implement commit_list_contains() Taylor Blau
2020-11-11 19:43 ` [PATCH 15/23] t5310: add branch-based checks Taylor Blau
2020-11-11 20:58   ` Derrick Stolee
2020-11-11 21:04     ` Junio C Hamano
2020-11-15 23:26       ` Johannes Schindelin
2020-11-11 19:43 ` [PATCH 16/23] pack-bitmap-write: rename children to reverse_edges Taylor Blau
2020-11-11 19:43 ` [PATCH 17/23] pack-bitmap-write: build fewer intermediate bitmaps Taylor Blau
2020-11-13 22:23   ` SZEDER Gábor
2020-11-13 23:03     ` Jeff King
2020-11-14  6:23       ` Jeff King
2020-11-11 19:43 ` [PATCH 18/23] pack-bitmap-write: ignore BITMAP_FLAG_REUSE Taylor Blau
2020-11-11 19:44 ` [PATCH 19/23] pack-bitmap: factor out 'bitmap_for_commit()' Taylor Blau
2020-11-11 19:44 ` [PATCH 20/23] pack-bitmap: factor out 'add_commit_to_bitmap()' Taylor Blau
2020-11-11 19:44 ` [PATCH 21/23] pack-bitmap-write: use existing bitmaps Taylor Blau
2020-11-11 19:44 ` [PATCH 22/23] pack-bitmap-write: relax unique rewalk condition Taylor Blau
2020-11-11 19:44 ` [PATCH 23/23] pack-bitmap-write: better reuse bitmaps Taylor Blau
2020-11-17 21:46 ` [PATCH v2 00/24] pack-bitmap: bitmap generation improvements Taylor Blau
2020-11-17 21:46   ` [PATCH v2 01/24] ewah/ewah_bitmap.c: grow buffer past 1 Taylor Blau
2020-11-17 21:46   ` [PATCH v2 02/24] pack-bitmap: fix header size check Taylor Blau
2020-11-17 21:46   ` [PATCH v2 03/24] pack-bitmap: bounds-check size of cache extension Taylor Blau
2020-11-17 21:46   ` [PATCH v2 04/24] t5310: drop size of truncated ewah bitmap Taylor Blau
2020-11-17 21:46   ` [PATCH v2 05/24] rev-list: die when --test-bitmap detects a mismatch Taylor Blau
2020-11-17 21:46   ` [PATCH v2 06/24] ewah: factor out bitmap growth Taylor Blau
2020-11-17 21:47   ` [PATCH v2 07/24] ewah: make bitmap growth less aggressive Taylor Blau
2020-11-17 21:47   ` [PATCH v2 08/24] ewah: implement bitmap_or() Taylor Blau
2020-11-17 21:47   ` [PATCH v2 09/24] ewah: add bitmap_dup() function Taylor Blau
2020-11-17 21:47   ` [PATCH v2 10/24] pack-bitmap-write: reimplement bitmap writing Taylor Blau
2020-11-25  0:53     ` Jonathan Tan
2020-11-28 17:27       ` Taylor Blau
2020-11-17 21:47   ` [PATCH v2 11/24] pack-bitmap-write: pass ownership of intermediate bitmaps Taylor Blau
2020-11-25  1:00     ` Jonathan Tan
2020-11-17 21:47   ` [PATCH v2 12/24] pack-bitmap-write: fill bitmap with commit history Taylor Blau
2020-11-22 21:50     ` Junio C Hamano
2020-11-23 14:54       ` Derrick Stolee
2020-11-25  1:14     ` Jonathan Tan
2020-11-28 17:21       ` Taylor Blau
2020-11-30 18:33         ` Jonathan Tan
2020-11-17 21:47   ` [PATCH v2 13/24] bitmap: add bitmap_diff_nonzero() Taylor Blau
2020-11-22 22:01     ` Junio C Hamano
2020-11-23 20:19       ` Taylor Blau
2020-11-17 21:47   ` [PATCH v2 14/24] commit: implement commit_list_contains() Taylor Blau
2020-11-17 21:47   ` [PATCH v2 15/24] t5310: add branch-based checks Taylor Blau
2020-11-25  1:17     ` Jonathan Tan
2020-11-28 17:30       ` Taylor Blau
2020-11-17 21:47   ` [PATCH v2 16/24] pack-bitmap-write: rename children to reverse_edges Taylor Blau
2020-11-17 21:47   ` [PATCH v2 17/24] pack-bitmap.c: check reads more aggressively when loading Taylor Blau
2020-11-17 21:48   ` [PATCH v2 18/24] pack-bitmap-write: build fewer intermediate bitmaps Taylor Blau
2020-11-24  6:07     ` Jonathan Tan
2020-11-25  1:46     ` Jonathan Tan
2020-11-30 18:41       ` Derrick Stolee
2020-11-17 21:48   ` [PATCH v2 19/24] pack-bitmap-write: ignore BITMAP_FLAG_REUSE Taylor Blau
2020-12-02  7:13     ` Jonathan Tan
2020-11-17 21:48   ` [PATCH v2 20/24] pack-bitmap: factor out 'bitmap_for_commit()' Taylor Blau
2020-12-02  7:17     ` Jonathan Tan
2020-11-17 21:48   ` [PATCH v2 21/24] pack-bitmap: factor out 'add_commit_to_bitmap()' Taylor Blau
2020-12-02  7:20     ` Jonathan Tan
2020-11-17 21:48   ` [PATCH v2 22/24] pack-bitmap-write: use existing bitmaps Taylor Blau
2020-12-02  7:28     ` Jonathan Tan
2020-12-02 16:21       ` Taylor Blau
2020-11-17 21:48   ` [PATCH v2 23/24] pack-bitmap-write: relax unique rewalk condition Taylor Blau
2020-12-02  7:44     ` Jonathan Tan
2020-12-02 16:30       ` Taylor Blau
2020-12-07 18:19         ` Jonathan Tan
2020-12-07 18:43           ` Derrick Stolee
2020-12-07 18:45             ` Derrick Stolee
2020-12-07 18:48           ` Jeff King
2020-11-17 21:48   ` [PATCH v2 24/24] pack-bitmap-write: better reuse bitmaps Taylor Blau
2020-12-02  8:08     ` Jonathan Tan
2020-12-02 16:35       ` Taylor Blau
2020-12-02 18:22         ` Derrick Stolee
2020-12-02 18:25           ` Taylor Blau
2020-12-07 18:26             ` Jonathan Tan
2020-12-07 18:24           ` Jonathan Tan
2020-12-07 19:20             ` Derrick Stolee
2020-11-18 18:32   ` [PATCH v2 00/24] pack-bitmap: bitmap generation improvements SZEDER Gábor
2020-11-18 19:51     ` Taylor Blau
2020-11-22  2:17       ` Taylor Blau
2020-11-22  2:28         ` Taylor Blau
2020-11-20  6:34   ` Martin Ågren
2020-11-21 19:37     ` Junio C Hamano
2020-11-21 20:11       ` Martin Ågren
2020-11-22  2:31         ` Taylor Blau
2020-11-24  2:43           ` Jeff King
2020-12-01 23:04             ` Taylor Blau
2020-12-01 23:37               ` Jonathan Tan
2020-12-01 23:43                 ` Taylor Blau
2020-12-02  8:11                   ` Jonathan Tan
2020-12-08  0:04 ` [PATCH v3 " Taylor Blau
2020-12-08  0:04   ` [PATCH v3 01/24] ewah/ewah_bitmap.c: avoid open-coding ALLOC_GROW() Taylor Blau
2020-12-08  0:04   ` [PATCH v3 02/24] pack-bitmap: fix header size check Taylor Blau
2020-12-08  0:04   ` [PATCH v3 03/24] pack-bitmap: bounds-check size of cache extension Taylor Blau
2020-12-08  0:04   ` [PATCH v3 04/24] t5310: drop size of truncated ewah bitmap Taylor Blau
2020-12-08  0:04   ` [PATCH v3 05/24] rev-list: die when --test-bitmap detects a mismatch Taylor Blau
2020-12-08  0:04   ` [PATCH v3 06/24] ewah: factor out bitmap growth Taylor Blau
2020-12-08  0:04   ` [PATCH v3 07/24] ewah: make bitmap growth less aggressive Taylor Blau
2020-12-08  0:04   ` [PATCH v3 08/24] ewah: implement bitmap_or() Taylor Blau
2020-12-08  0:04   ` [PATCH v3 09/24] ewah: add bitmap_dup() function Taylor Blau
2020-12-08  0:04   ` [PATCH v3 10/24] pack-bitmap-write: reimplement bitmap writing Taylor Blau
2020-12-08  0:05   ` [PATCH v3 11/24] pack-bitmap-write: pass ownership of intermediate bitmaps Taylor Blau
2020-12-08  0:05   ` [PATCH v3 12/24] pack-bitmap-write: fill bitmap with commit history Taylor Blau
2020-12-08  0:05   ` [PATCH v3 13/24] bitmap: implement bitmap_is_subset() Taylor Blau
2020-12-08  0:05   ` [PATCH v3 14/24] commit: implement commit_list_contains() Taylor Blau
2020-12-08  0:05   ` [PATCH v3 15/24] t5310: add branch-based checks Taylor Blau
2020-12-08  0:05   ` [PATCH v3 16/24] pack-bitmap-write: rename children to reverse_edges Taylor Blau
2020-12-08  0:05   ` [PATCH v3 17/24] pack-bitmap.c: check reads more aggressively when loading Taylor Blau
2020-12-08  0:05   ` [PATCH v3 18/24] pack-bitmap-write: build fewer intermediate bitmaps Taylor Blau
2020-12-08  0:05   ` [PATCH v3 19/24] pack-bitmap-write: ignore BITMAP_FLAG_REUSE Taylor Blau
2020-12-08  0:05   ` [PATCH v3 20/24] pack-bitmap: factor out 'bitmap_for_commit()' Taylor Blau
2020-12-08  0:05   ` [PATCH v3 21/24] pack-bitmap: factor out 'add_commit_to_bitmap()' Taylor Blau
2020-12-08  0:05   ` [PATCH v3 22/24] pack-bitmap-write: use existing bitmaps Taylor Blau
2020-12-08  0:05   ` [PATCH v3 23/24] pack-bitmap-write: relax unique rewalk condition Taylor Blau
2020-12-08  0:05   ` [PATCH v3 24/24] pack-bitmap-write: better reuse bitmaps Taylor Blau
2020-12-08 20:56   ` [PATCH v3 00/24] pack-bitmap: bitmap generation improvements Junio C Hamano
2020-12-08 21:03     ` Taylor Blau
2020-12-08 22:03       ` Junio C Hamano
2020-12-08 22:03 ` [PATCH v4 " Taylor Blau
2020-12-08 22:03   ` [PATCH v4 01/24] ewah/ewah_bitmap.c: avoid open-coding ALLOC_GROW() Taylor Blau
2020-12-08 22:03   ` [PATCH v4 02/24] pack-bitmap: fix header size check Taylor Blau
2020-12-08 22:03   ` [PATCH v4 03/24] pack-bitmap: bounds-check size of cache extension Taylor Blau
2020-12-08 22:03   ` [PATCH v4 04/24] t5310: drop size of truncated ewah bitmap Taylor Blau
2020-12-08 22:03   ` [PATCH v4 05/24] rev-list: die when --test-bitmap detects a mismatch Taylor Blau
2020-12-08 22:03   ` [PATCH v4 06/24] ewah: factor out bitmap growth Taylor Blau
2020-12-08 22:03   ` [PATCH v4 07/24] ewah: make bitmap growth less aggressive Taylor Blau
2020-12-08 22:03   ` [PATCH v4 08/24] ewah: implement bitmap_or() Taylor Blau
2020-12-08 22:03   ` [PATCH v4 09/24] ewah: add bitmap_dup() function Taylor Blau
2020-12-08 22:03   ` [PATCH v4 10/24] pack-bitmap-write: reimplement bitmap writing Taylor Blau
2020-12-08 22:03   ` [PATCH v4 11/24] pack-bitmap-write: pass ownership of intermediate bitmaps Taylor Blau
2020-12-08 22:04   ` [PATCH v4 12/24] pack-bitmap-write: fill bitmap with commit history Taylor Blau
2020-12-08 22:04   ` [PATCH v4 13/24] bitmap: implement bitmap_is_subset() Taylor Blau
2020-12-08 22:04   ` [PATCH v4 14/24] commit: implement commit_list_contains() Taylor Blau
2020-12-08 22:04   ` [PATCH v4 15/24] t5310: add branch-based checks Taylor Blau
2020-12-08 22:04   ` [PATCH v4 16/24] pack-bitmap-write: rename children to reverse_edges Taylor Blau
2020-12-08 22:04   ` [PATCH v4 17/24] pack-bitmap.c: check reads more aggressively when loading Taylor Blau
2020-12-08 22:04   ` [PATCH v4 18/24] pack-bitmap-write: build fewer intermediate bitmaps Taylor Blau
2020-12-08 22:04   ` [PATCH v4 19/24] pack-bitmap-write: ignore BITMAP_FLAG_REUSE Taylor Blau
2020-12-08 22:04   ` [PATCH v4 20/24] pack-bitmap: factor out 'bitmap_for_commit()' Taylor Blau
2020-12-08 22:05   ` [PATCH v4 21/24] pack-bitmap: factor out 'add_commit_to_bitmap()' Taylor Blau
2020-12-08 22:05   ` [PATCH v4 22/24] pack-bitmap-write: use existing bitmaps Taylor Blau
2020-12-08 22:05   ` [PATCH v4 23/24] pack-bitmap-write: relax unique revwalk condition Taylor Blau
2020-12-08 22:05   ` [PATCH v4 24/24] pack-bitmap-write: better reuse bitmaps Taylor Blau

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