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From: Changli Gao <xiaosuo@gmail.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>,
	hagen@jauu.net, wirelesser@gmail.com, netdev@vger.kernel.org,
	Dan Rosenberg <drosenberg@vsecurity.com>
Subject: Re: [PATCH net-next-2.6] filter: add a security check at install time
Date: Thu, 2 Dec 2010 18:10:05 +0800	[thread overview]
Message-ID: <AANLkTikkeQNzTMs_AifJFFU3oEKAmMBaCO9PCRWLRTSo@mail.gmail.com> (raw)
In-Reply-To: <1291283693.2871.48.camel@edumazet-laptop>

On Thu, Dec 2, 2010 at 5:54 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> Le jeudi 02 décembre 2010 à 17:10 +0800, Changli Gao a écrit :
>>
>> Oops. We were wrong. The RAM of BPF machine is initialized to 0. So
>> loading from a cell, in which no value is stored before, is valid. So
>> we can't prevent the following instructions.
>>
>
> It was not 'initialized to 0', thats the point of previous patches.
>

I checked the implementation of bpf in FreeBSD, and found RAM isn't
initialized to 0. Then it could not be a common 'feature', and no
application relies on it. Maybe we can drop this 'feature' added by
accident, and break the 'ABI'.

Now, I agree with you totally. Thank for your explaining..

Acked-by: Changli Gao <xiaosuo@gmail.com>

>
> (By the way, I believe FreeBSD has the security problem Dan reported to us)

Yes. it doesn't do this check.

-- 
Regards,
Changli Gao(xiaosuo@gmail.com)

  reply	other threads:[~2010-12-02 10:10 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-30  9:22 multi bpf filter will impact performance? Rui
2010-11-30  9:34 ` Eric Dumazet
     [not found]   ` <AANLkTi=VpmnrXTBNV7McQm6mq9ULT7KTKbM8_hLPoL=2@mail.gmail.com>
     [not found]     ` <1291127670.2904.96.camel@edumazet-laptop>
2010-12-01  3:48       ` Rui
2010-12-01  4:03         ` Eric Dumazet
2010-12-01  7:45           ` [PATCH net-next-2.6] filter: add SKF_AD_RXHASH and SKF_AD_CPU Eric Dumazet
2010-12-01  8:03             ` Changli Gao
2010-12-06 21:02             ` David Miller
2010-12-03  9:40           ` multi bpf filter will impact performance? Junchang Wang
2010-12-01  7:36         ` Changli Gao
2010-12-01  7:47           ` Eric Dumazet
2010-12-01  7:59             ` Changli Gao
2010-12-01  8:09               ` Eric Dumazet
2010-12-01  8:15                 ` Changli Gao
2010-12-01  8:42                   ` Eric Dumazet
2010-12-01 17:22                     ` Hagen Paul Pfeifer
2010-12-01 18:18                       ` David Miller
2010-12-01 18:24                         ` David Miller
2010-12-01 18:24                         ` Eric Dumazet
2010-12-01 18:44                           ` David Miller
2010-12-01 19:48                             ` Eric Dumazet
2010-12-01 20:23                               ` David Miller
2010-12-01 20:45                                 ` [PATCH net-next-2.6] filter: add a security check at install time Eric Dumazet
2010-12-02  2:30                                   ` Changli Gao
2010-12-02  6:46                                     ` Eric Dumazet
2010-12-02  8:11                                       ` Changli Gao
2010-12-02  8:53                                         ` Eric Dumazet
2010-12-02  9:00                                           ` Eric Dumazet
2010-12-02  9:10                                             ` Changli Gao
2010-12-02  9:54                                               ` Eric Dumazet
2010-12-02 10:10                                                 ` Changli Gao [this message]
2010-12-02 11:15                                                   ` Eric Dumazet
2010-12-02 11:29                                                     ` Changli Gao
2010-12-02 13:14                                                       ` Eric Dumazet
2010-12-02 10:59                                             ` Changli Gao
2010-12-06 21:07                                       ` David Miller
2010-12-03  6:32                         ` multi bpf filter will impact performance? Eric Dumazet
2010-12-05 20:53                           ` PATCH] filter: fix sk_filter rcu handling Eric Dumazet
2010-12-05 21:08                             ` Andi Kleen
2010-12-05 21:28                               ` Eric Dumazet
2010-12-06 17:29                             ` David Miller
2010-11-30 10:01 ` multi bpf filter will impact performance? Eric Dumazet
2010-11-30 11:17 ` Eric Dumazet

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