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From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: aduyck@mirantis.com, netdev@vger.kernel.org,
	alexander.duyck@gmail.com, sowmini.varadhan@oracle.com,
	tom@herbertland.com
Subject: Re: [net PATCH] flow_dissector: Fix unaligned access in __skb_flow_dissector when used by eth_get_headlen
Date: Fri, 29 Jan 2016 19:35:20 -0800 (PST)	[thread overview]
Message-ID: <20160129.193520.477355610549821770.davem@davemloft.net> (raw)
In-Reply-To: <1454124234.7627.119.camel@edumazet-glaptop2.roam.corp.google.com>

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 29 Jan 2016 19:23:54 -0800

> On Fri, 2016-01-29 at 18:49 -0800, Alexander Duyck wrote:
>> This patch fixes an issue with unaligned accesses when using
>> eth_get_headlen on a page that was DMA aligned instead of being IP aligned.
>> The fact is when trying to check the length we don't need to be looking at
>> the flow label so we can reorder the checks to first check if we are
>> supposed to gather the flow label and then make the call to actually get
>> it.
>> 
>> Reported-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
>> Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
>> ---
> 
> 
> You did not quite follow the discussion Alexander, we did not exactly
> took a decision about this bug.
> 
> As we mentioned, there are other parts that need care.
> 
> key_keyid->keyid = *keyid;
> 
> Please address them, instead of having to 'wait' for the next crash.

Indeed, this is a more fundamental issue.

This change in and of itself isn't bad, and is probably a suitable
micro-optimization for net-next, but it doesn't fix the bug in
question.

  reply	other threads:[~2016-01-30  3:35 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-29 18:06 [RFC] Kernel unaligned access at __skb_flow_dissect Sowmini Varadhan
2016-01-29 18:33 ` Eric Dumazet
2016-01-29 18:40   ` Eric Dumazet
2016-01-29 19:08     ` David Miller
2016-01-29 19:39       ` Eric Dumazet
2016-01-29 18:54   ` Eric Dumazet
2016-01-29 19:22     ` Sowmini Varadhan
2016-01-29 21:00     ` Tom Herbert
2016-01-29 21:09       ` Sowmini Varadhan
2016-01-29 21:33         ` Tom Herbert
2016-01-29 23:00         ` Tom Herbert
2016-01-29 23:04           ` Sowmini Varadhan
2016-01-29 23:31             ` Tom Herbert
2016-01-29 23:58               ` Sowmini Varadhan
2016-01-30  0:47                 ` Tom Herbert
2016-01-30  1:18                   ` David Miller
2016-01-30  2:15                   ` Eric Dumazet
2016-01-31 22:13                     ` Tom Herbert
2016-02-01  0:04                       ` Eric Dumazet
2016-01-29 19:06   ` David Miller
2016-01-29 19:37     ` Eric Dumazet
2016-01-29 19:41       ` David Miller
2016-01-29 19:44       ` Sowmini Varadhan
2016-01-29 20:01         ` Eric Dumazet
2016-01-29 20:06           ` Eric Dumazet
2016-01-29 21:16           ` Alexander Duyck
2016-01-29 21:33             ` Eric Dumazet
2016-01-29 22:08               ` Alexander Duyck
2016-01-29 22:28                 ` Eric Dumazet
2016-01-29 23:00                   ` Alexander Duyck
2016-02-01 16:55                   ` David Laight
2016-02-01 17:25                     ` Eric Dumazet
2016-01-29 19:04 ` David Miller
2016-01-30  2:49 ` [net PATCH] flow_dissector: Fix unaligned access in __skb_flow_dissector when used by eth_get_headlen Alexander Duyck
2016-01-30  3:23   ` Eric Dumazet
2016-01-30  3:35     ` David Miller [this message]
2016-01-30  4:46       ` Alexander Duyck
2016-01-30 16:17     ` Sowmini Varadhan
2016-01-30 17:43       ` Tom Herbert
2016-01-30 19:12         ` Sowmini Varadhan
2016-01-30 18:36       ` Alexander Duyck
2016-01-30 19:26         ` Eric Dumazet
2016-01-31  1:13           ` Alexander Duyck
2016-01-31  3:45             ` David Miller
2016-01-31  9:12               ` Alexander Duyck
2016-01-31 19:17                 ` David Miller
2016-01-31 21:23                   ` Sowmini Varadhan
2016-02-01 16:50               ` David Laight
2016-02-01 18:18                 ` Alexander Duyck
2016-02-02  9:47                   ` David Laight

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