From mboxrd@z Thu Jan  1 00:00:00 1970
From: Richard Cochran <richardcochran@gmail.com>
Subject: Re: [PATCH v2] net: dsa: mv88e6xxx: hwtstamp: fix potential negative
 array index read
Date: Fri, 16 Feb 2018 07:56:17 -0800
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References: <20180215183139.GA23076@embeddedor.com>
 <20180216154846.7ge6seynwxjkopmp@localhost>
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Cc: Brandon Streiff <brandon.streiff@ni.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
To: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
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On Fri, Feb 16, 2018 at 07:48:46AM -0800, Richard Cochran wrote:
> On Thu, Feb 15, 2018 at 12:31:39PM -0600, Gustavo A. R. Silva wrote:
> > _port_ is being used as index to array port_hwtstamp before verifying
> > it is a non-negative number and a valid index at line 209 and 258:
> > 
> > if (port < 0 || port >= mv88e6xxx_num_ports(chip))
> > 
> > Fix this by checking _port_ before using it as index to array
> > port_hwtstamp.
> 
> NAK.   Port is already known to be valid in the callers.

And so the real bug is the pointless range checking tests.  I would
welcome patches to remove those.

Thanks,
Richard