linux-kernel - Re: [PATCH] psi:fix divide by zero in psi_update

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: <20191108093136.GI4114@hirez.programming.kicks-ass.net>
Date:   Fri, 8 Nov 2019 10:31:36 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     tim <xiejingfeng@...ux.alibaba.com>
Cc:     Johannes Weiner <hannes@...xchg.org>,
        Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] psi:fix divide by zero in psi_update_stats

On Fri, Nov 08, 2019 at 03:33:24PM +0800, tim wrote:
> In psi_update_stats, it is possible that period has value like
> 0xXXXXXXXX00000000 where the lower 32 bit is 0, then it calls div_u64 which

How can this happen? Is that a valid case or should we be avoiding that?