netdev - Re: [net-next 1/8] e1000e: Minimum packet size must be 17 bytes

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]

Date:	Tue, 23 Oct 2012 09:37:08 -0700
From:	Alexander Duyck <alexander.h.duyck@...el.com>
To:	David Laight <David.Laight@...LAB.COM>
CC:	Jeff Kirsher <jeffrey.t.kirsher@...el.com>, davem@...emloft.net,
	Tushar Dave <tushar.n.dave@...el.com>, netdev@...r.kernel.org,
	gospo@...hat.com, sassmann@...hat.com
Subject: Re: [net-next 1/8] e1000e: Minimum packet size must be 17 bytes

On 10/23/2012 08:25 AM, David Laight wrote:
>> This is a HW requirement. Although a buffer as short as 1 byte is allowed,
>> the total length of packet before, padding and CRC insertion, must be at
>> least 17 bytes.  So pad all small packets manually up to 17 bytes before
>> delivering them to HW.
> Where do such very short packets come from?
> The shortest one I know of have:
>  6 bytes dest-mac
>  6 bytes src-mac
>  2 bytes length
>  3 bytes llc header (eg reflect request).
> 17 bytes total.
>
> 	David
>

This mostly has to do with security fuzz testers sending raw packets at
the interface trying to see what can cause it to hang.  As far as I know
nothing from the stack will be that small, but we still have to support
raw packets that size.

Thanks,

Alex
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html