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From: Kees Cook <kees@kernel.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: Breno Leitao <leitao@debian.org>,
	Justin Stitt <justinstitt@google.com>,
	elver@google.com, andreyknvl@gmail.com, ryabinin.a.a@gmail.com,
	kasan-dev@googlegroups.com, linux-hardening@vger.kernel.org,
	asml.silence@gmail.com, netdev@vger.kernel.org
Subject: Re: UBSAN: annotation to skip sanitization in variable that will wrap
Date: Fri, 16 Aug 2024 12:47:00 -0700	[thread overview]
Message-ID: <202408151400.614790C62@keescook> (raw)
In-Reply-To: <1019eec3-3b1c-42b4-9649-65f58284bfec@kernel.dk>

On Thu, Aug 15, 2024 at 12:40:12PM -0600, Jens Axboe wrote:
> On 8/15/24 11:58 AM, Breno Leitao wrote:
> >> 1) There exists some new-ish macros in overflow.h that perform
> >> wrapping arithmetic without triggering sanitizer splats -- check out
> >> the wrapping_* suite of macros.
> > 
> > do they work for atomic? I suppose we also need to have them added to
> > this_cpu_add(), this_cpu_sub() helpers.
> 
> I don't think so, it's the bias added specifically to the atomic_long_t
> that's the issue with the percpu refs.

Yeah, the future annotations will be variable attributes, so it should
be much nicer to apply.

-- 
Kees Cook

      reply	other threads:[~2024-08-16 19:47 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-14 17:10 UBSAN: annotation to skip sanitization in variable that will wrap Breno Leitao
2024-08-14 21:05 ` Justin Stitt
2024-08-15 16:20   ` Kees Cook
2024-08-15 17:58   ` Breno Leitao
2024-08-15 18:40     ` Jens Axboe
2024-08-16 19:47       ` Kees Cook [this message]

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