From: Kees Cook <keescook@chromium.org>
To: Siddhesh Poyarekar <siddhesh@gotplt.org>
Cc: Qing Zhao <qing.zhao@oracle.com>,
joseph@codesourcery.com, richard.guenther@gmail.com,
jakub@redhat.com, gcc-patches@gcc.gnu.org, uecker@tugraz.at,
isanbard@gmail.com
Subject: Re: [V3][PATCH 0/3] New attribute "counted_by" to annotate bounds for C99 FAM(PR108896)
Date: Thu, 5 Oct 2023 15:35:02 -0700 [thread overview]
Message-ID: <202310051529.7F8FEFBAA@keescook> (raw)
In-Reply-To: <d8858981-05fa-a063-6681-e723205b8969@gotplt.org>
On Thu, Oct 05, 2023 at 04:08:52PM -0400, Siddhesh Poyarekar wrote:
> 2. How would you handle signedness of the size field? The size gets
> converted to sizetype everywhere it is used and overflows/underflows may
> produce interesting results. Do you want to limit the types to unsigned or
> do you want to add a disclaimer in the docs? The former seems like the
> *right* thing to do given that it is a new feature; best to enforce the
> cleaner habit at the outset.
The Linux kernel has a lot of "int" counters, so the goal is to catch
negative offsets just like too-large offsets at runtime with the sanitizer
and report 0 for __bdos. Refactoring all these to be unsigned is going
to take time since at least some of them use the negative values as
special values unrelated to array indexing. :(
So, perhaps if unsigned counters are worth enforcing, can this be a
separate warning the kernel can turn off initially?
-Kees
--
Kees Cook
next prev parent reply other threads:[~2023-10-05 22:35 UTC|newest]
Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-25 15:24 Qing Zhao
2023-08-25 15:24 ` [V3][PATCH 1/3] Provide counted_by attribute to flexible array member field (PR108896) Qing Zhao
2023-09-08 14:12 ` Qing Zhao
2023-09-20 13:44 ` Ping * 2: " Qing Zhao
2023-10-05 18:51 ` Siddhesh Poyarekar
2023-10-05 19:31 ` Siddhesh Poyarekar
2023-10-18 14:51 ` Qing Zhao
2023-10-18 15:18 ` Siddhesh Poyarekar
2023-10-18 15:37 ` Qing Zhao
2023-10-18 14:41 ` Qing Zhao
2023-08-25 15:24 ` [V3][PATCH 2/3] Use the counted_by atribute info in builtin object size [PR108896] Qing Zhao
2023-09-08 14:12 ` Qing Zhao
2023-09-20 13:44 ` PING *2: " Qing Zhao
2023-10-05 20:01 ` Siddhesh Poyarekar
2023-10-18 20:39 ` Qing Zhao
2023-08-25 15:24 ` [V3][PATCH 3/3] Use the counted_by attribute information in bound sanitizer[PR108896] Qing Zhao
2023-09-08 14:12 ` Qing Zhao
2023-09-20 13:45 ` PING * 2: " Qing Zhao
2023-08-25 19:51 ` [V3][PATCH 0/3] New attribute "counted_by" to annotate bounds for C99 FAM(PR108896) Kees Cook
2023-09-08 14:11 ` Qing Zhao
2023-09-20 13:43 ` PING * 2: " Qing Zhao
2023-10-05 20:08 ` Siddhesh Poyarekar
2023-10-05 22:35 ` Kees Cook [this message]
2023-10-06 5:11 ` Martin Uecker
2023-10-06 10:50 ` Siddhesh Poyarekar
2023-10-06 20:01 ` Martin Uecker
2023-10-18 15:37 ` Siddhesh Poyarekar
2023-10-18 19:35 ` Qing Zhao
2023-10-18 21:11 ` Qing Zhao
2023-10-19 23:33 ` Kees Cook
2023-10-20 9:50 ` Martin Uecker
2023-10-20 18:34 ` Kees Cook
2023-10-20 18:48 ` Qing Zhao
2023-10-20 19:54 ` Martin Uecker
2023-10-23 18:17 ` Qing Zhao
2023-10-23 19:52 ` Kees Cook
2023-10-23 19:57 ` Martin Uecker
2023-10-23 22:03 ` Kees Cook
2023-10-20 17:08 ` HELP: Will the reordering happen? " Qing Zhao
2023-10-20 18:22 ` Richard Biener
2023-10-20 18:38 ` Qing Zhao
2023-10-20 19:10 ` Siddhesh Poyarekar
2023-10-20 20:41 ` Qing Zhao
2023-10-23 7:57 ` Richard Biener
2023-10-23 11:27 ` Siddhesh Poyarekar
2023-10-23 12:34 ` Richard Biener
2023-10-23 13:23 ` Siddhesh Poyarekar
2023-10-23 15:14 ` Qing Zhao
2023-10-23 14:56 ` Qing Zhao
2023-10-23 15:57 ` Richard Biener
2023-10-23 16:37 ` Qing Zhao
2023-10-23 18:06 ` Martin Uecker
2023-10-23 18:31 ` Martin Uecker
2023-10-23 19:00 ` Qing Zhao
2023-10-23 19:37 ` Martin Uecker
2023-10-23 20:33 ` Qing Zhao
2023-10-23 18:33 ` Qing Zhao
2023-10-23 18:43 ` Siddhesh Poyarekar
2023-10-23 18:55 ` Martin Uecker
2023-10-23 19:43 ` Qing Zhao
2023-10-23 22:48 ` Siddhesh Poyarekar
2023-10-24 20:30 ` Qing Zhao
2023-10-24 20:38 ` Martin Uecker
2023-10-24 21:09 ` Siddhesh Poyarekar
2023-10-24 22:51 ` Qing Zhao
2023-10-24 23:56 ` Siddhesh Poyarekar
2023-10-25 13:27 ` Qing Zhao
2023-10-25 14:50 ` Siddhesh Poyarekar
2023-10-25 15:38 ` Richard Biener
2023-10-25 19:03 ` Qing Zhao
2023-10-26 5:21 ` Jakub Jelinek
2023-10-26 8:56 ` Richard Biener
2023-10-26 14:58 ` Qing Zhao
2023-10-26 15:48 ` Richard Biener
2023-10-26 16:16 ` Martin Uecker
2023-10-26 14:41 ` Qing Zhao
2023-10-25 18:44 ` Qing Zhao
2023-10-25 22:06 ` Kees Cook
2023-10-25 22:27 ` Qing Zhao
2023-10-25 22:32 ` Kees Cook
2023-10-26 8:15 ` Martin Uecker
2023-10-26 16:13 ` Kees Cook
2023-10-26 16:45 ` Martin Uecker
2023-10-26 19:57 ` Qing Zhao
2023-10-27 7:21 ` Martin Uecker
2023-10-27 14:32 ` Qing Zhao
2023-10-27 14:53 ` Martin Uecker
2023-10-27 15:10 ` Qing Zhao
2023-10-27 17:19 ` Kees Cook
2023-10-27 18:13 ` Qing Zhao
2023-10-25 5:26 ` Martin Uecker
2023-10-25 6:43 ` Richard Biener
2023-10-25 8:16 ` Martin Uecker
2023-10-25 10:25 ` Richard Biener
2023-10-25 10:39 ` Martin Uecker
2023-10-25 18:06 ` Qing Zhao
2023-10-25 10:25 ` Siddhesh Poyarekar
2023-10-25 10:47 ` Martin Uecker
2023-10-25 11:13 ` Richard Biener
2023-10-25 18:16 ` Martin Uecker
2023-10-26 8:45 ` Richard Biener
2023-10-26 9:20 ` Martin Uecker
2023-10-26 10:14 ` Martin Uecker
2023-10-26 14:05 ` Richard Biener
2023-10-26 18:54 ` Qing Zhao
2023-10-27 16:43 ` Qing Zhao
2023-10-26 16:41 ` Qing Zhao
2023-10-26 17:05 ` Martin Uecker
2023-10-26 17:35 ` Richard Biener
2023-10-26 19:20 ` Qing Zhao
2023-10-25 18:17 ` Qing Zhao
2023-10-24 21:03 ` Siddhesh Poyarekar
2023-10-24 22:41 ` Qing Zhao
2023-10-24 23:51 ` Siddhesh Poyarekar
2023-10-25 21:59 ` Kees Cook
2023-10-23 18:10 ` Joseph Myers
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