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Are linux network drivers really affected by this?

DISCUSSION Nils Petter Vaskinn 6 participants 10 messages Jan 9, 2003 – Jan 18, 2003

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#1 lore raw
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"npv" == Nils Petter Vaskinn <[email protected]> writes:

npv> http://www.kb.cert.org/vuls/id/412115

npv> Summary: Some network drivers don't pad ethernet packets with npv> nulls, they are filled with "garbage" often from previously npv> sent packets. Linux is mentioned as vulnerable.

The paper presented by Olaf Arkin (amongst other) points to some parts of the linux code where this "vulnerability" exists. I think Alan Cox is working on some patches for his tree. I wonder whether it's better
to null-pad ethernet packets or to fill them with random values
(possibly an overkill, but more resiliant against fingerprinting).

bye,

andrea
--
Andrea Glorioso [email protected]

Binary Only                           http://www.binary-only.com/
Via A. Zanolini, 7/b                  Tel:     +39-348.921.43.79
40126 Bologna                         Fax:     +39-051-930.31.133
#2 lore raw
Quoted 5 lines · On Fri, 2003-01-10 at 08:08, [email protected] wrote:

The paper presented by Olaf Arkin (amongst other) points to some parts of the linux code where this "vulnerability" exists. I think Alan Cox is working on some patches for his tree. I wonder whether it's better
to null-pad ethernet packets or to fill them with random values
(possibly an overkill, but more resiliant against fingerprinting).

Most of them will pad with zero. We have a couple of drivers that already pad with something along the lines of "NetBSD is a cool OS too.."

The -ac tree should have the problem fixed for all the drivers I know have the problem or may do.

#3 lore raw
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"ac" == Alan Cox <[email protected]> writes:

ac> Most of them will pad with zero. We have a couple of drivers ac> that already pad with something along the lines of "NetBSD is ac> a cool OS too.."

Let's talk about subliminal messages, then. :)

How sensible would it be to have a runtime or compile time option for choosing between zero padding and random values padding? I think the variable length of the padding could cause some performance problems, but I'm no kernel hacker nor cryptography expert.

ac> The -ac tree should have the problem fixed for all the drivers ac> I know have the problem or may do.

Great.

bye,

andrea
--
Andrea Glorioso [email protected]

Binary Only                           http://www.binary-only.com/
Via A. Zanolini, 7/b                  Tel:     +39-348.921.43.79
40126 Bologna                         Fax:     +39-051-930.31.133
#4 lore raw
Quoted 6 lines · On 10 January 2003 13:12, [email protected] wrote:
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"ac" == Alan Cox <[email protected]> writes:

ac> Most of them will pad with zero. We have a couple of
drivers ac> that already pad with something along the lines of "NetBSD is ac> a cool OS too.."

Quoted 7 lines

Let's talk about subliminal messages, then. :)

How sensible would it be to have a runtime or compile time option for choosing between zero padding and random values padding? I think the variable length of the padding could cause some performance problems, but I'm no kernel hacker nor cryptography expert.

Too much work for zero gain
--
vda

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Quoted 6 lines · On 10 January 2003 16:53, [email protected] wrote:
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"dv" == Denis Vlasenko <[email protected]> writes:

dv> Too much work for zero gain

`Too much work' refers to coding time or to kernel work?

Coding.

IMHO:

Zero padding is secure enough.
There is no point spending time coding random
padding, config options, etc.
--
vda

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"dv" == Denis Vlasenko <[email protected]> writes:

    dv> On 10 January 2003 16:53, [email protected]
    dv> wrote:
    >> >>>>> "dv" == Denis Vlasenko
    >> <[email protected]> >>>>> writes:
    >> 
    dv> Too much work for zero gain
    >> `Too much work' refers to coding time or to kernel work?

    dv> Coding.

I would have said `kernel work' (although the relative occurrence of undersized frames is probably low).

dv> IMHO:

dv> Zero padding is secure enough.

Not for fingerprinting, though.

dv> There is no point spending time coding random padding, config dv> options, etc.

You're probably right.

bye,

andrea
--
Andrea Glorioso [email protected]

Binary Only                           http://www.binary-only.com/
Via A. Zanolini, 7/b                  Tel:     +39-348.921.43.79
40126 Bologna                         Fax:     +39-051-930.31.133
#8 lore raw
In reply to [email protected]
Quoted 5 lines · [email protected] writes:

ac> Most of them will pad with zero. We have a couple of drivers ac> that already pad with something along the lines of "NetBSD is ac> a cool OS too.."

Let's talk about subliminal messages, then. :)

How about `Printer on fire'?

-Miles

Signature · 1 line
I have seen the enemy, and he is us.  -- Pogo
#9 lore raw
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ac> Most of them will pad with zero. We have a couple of drivers ac> that already pad with something along the lines of "NetBSD is ac> a cool OS too.."

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Let's talk about subliminal messages, then. :)

How about `Printer on fire'?

I vote for padding with"

"Linus is god!"
Repeating the exclamation-mark as much as needed.

Folkert
www.vanheusden.com