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From: Kalle Valo <kvalo@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: linux-hardening@vger.kernel.org,  Brian Norris
 <briannorris@chromium.org>,  Jonas =?utf-8?Q?Dre=C3=9Fler?=
 <verdre@v0yd.nl>,  Dmitry
 Antipov <dmantipov@yandex.ru>,  Tsuchiya Yuto <kitakar@gmail.com>,
  linux-wireless@vger.kernel.org,  "Gustavo A. R. Silva"
 <gustavoars@kernel.org>,  Bill Wendling <morbo@google.com>,  Justin Stitt
 <justinstitt@google.com>,  linux-kernel@vger.kernel.org
Subject: Re: [PATCH 62/82] mwifiex: pcie: Refactor intentional wrap-around test
References: <20240122235208.work.748-kees@kernel.org>
	<20240123002814.1396804-62-keescook@chromium.org>
Date: Tue, 23 Jan 2024 08:36:38 +0200
In-Reply-To: <20240123002814.1396804-62-keescook@chromium.org> (Kees Cook's
	message of "Mon, 22 Jan 2024 16:27:37 -0800")
Message-ID: <87bk9ceetl.fsf@kernel.org>
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Kees Cook <keescook@chromium.org> writes:

> In an effort to separate intentional arithmetic wrap-around from
> unexpected wrap-around, we need to refactor places that depend on this
> kind of math. One of the most common code patterns of this is:
>
> 	VAR + value < VAR
>
> Notably, this is considered "undefined behavior" for signed and pointer
> types, which the kernel works around by using the -fno-strict-overflow
> option in the build[1] (which used to just be -fwrapv). Regardless, we
> want to get the kernel source to the position where we can meaningfully
> instrument arithmetic wrap-around conditions and catch them when they
> are unexpected, regardless of whether they are signed[2], unsigned[3],
> or pointer[4] types.
>
> Refactor open-coded wrap-around addition test to use add_would_overflow().
> This paves the way to enabling the wrap-around sanitizers in the future.
>
> Link: https://git.kernel.org/linus/68df3755e383e6fecf2354a67b08f92f185365=
94 [1]
> Link: https://github.com/KSPP/linux/issues/26 [2]
> Link: https://github.com/KSPP/linux/issues/27 [3]
> Link: https://github.com/KSPP/linux/issues/344 [4]
> Cc: Brian Norris <briannorris@chromium.org>
> Cc: Kalle Valo <kvalo@kernel.org>
> Cc: "Jonas Dre=C3=9Fler" <verdre@v0yd.nl>
> Cc: Dmitry Antipov <dmantipov@yandex.ru>
> Cc: Tsuchiya Yuto <kitakar@gmail.com>
> Cc: linux-wireless@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

I assume this goes via some other tree than wireless-next so:

Acked-by: Kalle Valo <kvalo@kernel.org>

--=20
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatc=
hes