From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: jengelh@inai.de, kadlec@blackhole.kfki.hu, sploving1@gmail.com,
pablo@netfilter.org, kaber@trash.net,
netfilter-devel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: BUG: net/netfilter: KASAN: stack-out-of-bounds in tcp_packet
Date: Mon, 28 Mar 2016 19:54:57 -0400 (EDT) [thread overview]
Message-ID: <20160328.195457.1407210954449940457.davem@davemloft.net> (raw)
In-Reply-To: <1459198306.6473.126.camel@edumazet-glaptop3.roam.corp.google.com>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 28 Mar 2016 13:51:46 -0700
> On Mon, 2016-03-28 at 13:46 -0700, Eric Dumazet wrote:
>
>> We have at least 384 bytes of padding in skb->head (this is struct
>> skb_shared_info).
>>
>> Whatever garbage we might read, current code is fine.
>>
>> We have to deal with a false positive here.
>
> Very similar to the one fixed in
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=10ec9472f05b45c94db3c854d22581a20b97db41
I don't see them as similar.
The current options code we are talking about here never references
past legitimate parts of the packet data. We always check 'length',
and we never access past the boundary it describes.
This was the entire point of my posting.
Talking about padding, rather than the logical correctness of the
code, is therefore a distraction I think :-)
next prev parent reply other threads:[~2016-03-28 23:55 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-27 12:35 BUG: net/netfilter: KASAN: stack-out-of-bounds in tcp_packet Baozeng Ding
2016-03-27 22:11 ` Jozsef Kadlecsik
2016-03-27 22:25 ` Jozsef Kadlecsik
[not found] ` <56F8987B.5030501@gmail.com>
2016-03-28 13:14 ` Baozeng Ding
2016-03-28 16:48 ` Jozsef Kadlecsik
2016-03-28 17:05 ` Pablo Neira Ayuso
2016-03-28 19:29 ` David Miller
2016-03-28 20:07 ` Eric Dumazet
2016-03-28 20:20 ` Jan Engelhardt
2016-03-28 20:46 ` Eric Dumazet
2016-03-28 20:51 ` Eric Dumazet
2016-03-28 23:54 ` David Miller [this message]
2016-03-29 1:17 ` Eric Dumazet
2016-03-28 21:11 ` Jozsef Kadlecsik
2016-03-28 21:29 ` Eric Dumazet
2016-03-28 23:52 ` David Miller
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