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Date: Sat, 29 Apr 2017 07:17:28 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Joe Perches <joe@perches.com>
Cc: Geliang Tang <geliangtang@gmail.com>, Ian Abbott <abbotti@mev.co.uk>,
        H Hartley Sweeten <hsweeten@visionengravers.com>,
        Arnd Bergmann <arnd@arndb.de>, devel@driverdev.osuosl.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] staging: comedi: use memdup_user
Message-ID: <20170429051728.GA10599@kroah.com>
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On Fri, Apr 28, 2017 at 06:53:32PM -0700, Joe Perches wrote:
> On Sat, 2017-04-29 at 09:45 +0800, Geliang Tang wrote:
> > Use memdup_user() helper instead of open-coding to simplify the code.
> 
> While I doubt this is a problem, this loses
> the multiplication overflow check for
> sizeof(*insns) * insnlist.n_isns

Yes it is a problem, we need that check.

thanks,

greg k-h