netdev - Re: [PATCH] net: ethernet: ti: Prevent divide-by-zero in cpts_calc_mult

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: <CAH-r-ZH+0rsji1f9eEaVDtG3XcMCD_EnAHAMwr8DuqO4D4Ps=w@mail.gmail.com>
Date: Thu, 28 Aug 2025 20:38:20 +0800
From: 林妙倩 <linmq006@...il.com>
To: Vadim Fedorenko <vadim.fedorenko@...ux.dev>
Cc: Andrew Lunn <andrew+netdev@...n.ch>, "David S. Miller" <davem@...emloft.net>, 
	Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, 
	Matthias Brugger <matthias.bgg@...il.com>, 
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>, 
	Thomas Gleixner <tglx@...utronix.de>, Grygorii Strashko <grygorii.strashko@...com>, netdev@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH] net: ethernet: ti: Prevent divide-by-zero in cpts_calc_mult_shift()

Hi, Vadim

Vadim Fedorenko <vadim.fedorenko@...ux.dev> 于2025年8月28日周四 20:06写道：
>
> On 28/08/2025 10:22, Miaoqian Lin wrote:
> > cpts_calc_mult_shift() has a potential divide-by-zero in this line:
> >
> >          do_div(maxsec, freq);
> >
> > due to the fact that clk_get_rate() can return zero in certain error
> > conditions.
>
> Have you seen this happening in the real environment, or is it just
> analysis of the code? I don't see a reason for these "certain error
> conditions" to happen...

This is from code analysis, not from real environment.
The !CONFIG_HAVE_CLK version of clk_get_rate() returns zero.
With CONFIG_COMPILE_TEST && !CONFIG_HAVE_CLK could have the problem.
This may be theoretical.