linux-kernel - Re: [PATCH RESEND v6 2/8] blk-throttle: prevent overflow while calculating wait time

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <YuGD1s2TJ9euYpCv@slm.duckdns.org>
Date:   Wed, 27 Jul 2022 08:28:38 -1000
From:   Tejun Heo <tj@...nel.org>
To:     Yu Kuai <yukuai1@...weicloud.com>
Cc:     mkoutny@...e.com, axboe@...nel.dk, ming.lei@...hat.com,
        cgroups@...r.kernel.org, linux-block@...r.kernel.org,
        linux-kernel@...r.kernel.org, yukuai3@...wei.com,
        yi.zhang@...wei.com
Subject: Re: [PATCH RESEND v6 2/8] blk-throttle: prevent overflow while
 calculating wait time

On Fri, Jul 01, 2022 at 05:34:35PM +0800, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@...wei.com>
> 
> In tg_with_in_bps_limit(), 'bps_limit * jiffy_elapsed_rnd' might
> overflow. FIx the problem by calling mul_u64_u64_div_u64() instead.
> 
> Signed-off-by: Yu Kuai <yukuai3@...wei.com>

Acked-by: Tejun Heo <tj@...nel.org>

BTW, have you observed this happening or is it from just reviewing the code?

Thanks.

-- 
tejun