From: David Laight <David.Laight@ACULAB.COM>
To: "'Gustavo A. R. Silva'" <garsilva@embeddedor.com>,
Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
"Wong Hoi Sing, Edison" <hswong3i@gmail.com>,
"Hung Hing Lun, Mike" <hlhung3i@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] tcp_lp: use 64-bit arithmetic instead of 32-bit
Date: Thu, 1 Feb 2018 10:14:29 +0000 [thread overview]
Message-ID: <ef625a4f15144822a037ddabc33a4134@AcuMS.aculab.com> (raw)
In-Reply-To: <20180131190749.Horde.bsc7GhewsZwdnkmDtMlSwWO@gator4166.hostgator.com>
> > The question you need to ask is 'can it overflow 32bit maths', otherwise
> > you are potentially making the system do extra work for no reason.
> >
>
> Yeah, I get your point and it seems that in this particular case there
> is no risk of a 32bit overflow, but in general and IMHO as the code
> evolves, the use of incorrect arithmetic may have security
> implications in the future, so I advocate for code correctness in this
> case.
Even if the variable are 64bit you still need to worry (maybe less)
about arithmetic overflow.
The only real way to avoid overflow is to understand the domain
of the values being used.
David
next prev parent reply other threads:[~2018-02-01 10:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-01 0:24 Gustavo A. R. Silva
2018-02-01 0:32 ` Alan Cox
2018-02-01 1:07 ` Gustavo A. R. Silva
2018-02-01 1:51 ` Andrew Lunn
2018-02-02 2:32 ` Gustavo A. R. Silva
2018-02-01 10:14 ` David Laight [this message]
2018-02-02 2:33 ` Gustavo A. R. Silva
2018-02-01 14:45 ` David Miller
2018-02-02 2:38 ` Gustavo A. R. Silva
2018-02-02 9:32 ` kbuild test robot
2018-02-02 10:44 ` kbuild test robot
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