netdev - Re: [PATCH net-next 2/2] net: systemport: pad packets to a minimum of 64 bytes

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Message-ID: <1399150011.24523.72.camel@deadeye.wl.decadent.org.uk>
Date:	Sat, 03 May 2014 21:46:51 +0100
From:	Ben Hutchings <ben@...adent.org.uk>
To:	Florian Fainelli <f.fainelli@...il.com>
Cc:	netdev@...r.kernel.org, davem@...emloft.net
Subject: Re: [PATCH net-next 2/2] net: systemport: pad packets to a minimum
 of 64 bytes

On Sat, 2014-05-03 at 11:31 -0700, Florian Fainelli wrote:
> The switch fabric which is used behind the Broadcom SYSTEMPORT Ethernet
> controller will discard any incoming packet that is not 64 bytes or
> more. Since the UniMAC hardware automatically pads up to the specified
> length, we can simply ensure we instruct it to transmit >= 64 bytes
> packets.
[...]

No, you have to pad with zeroes (skb_padto()) otherwise you're leaking
potentially sensitive data.

Ben.

-- 
Ben Hutchings
All the simple programs have been written, and all the good names taken.

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