From mboxrd@z Thu Jan  1 00:00:00 1970
From: Simon Horman <horms@verge.net.au>
Subject: Re: [PATCH net-next v5 1/2] net: Use 16bits for *_headers fields of
 struct skbuff
Date: Thu, 30 May 2013 12:00:53 +0900
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Cc: dev <dev@openvswitch.org>,
	Network Development <netdev@vger.kernel.org>,
	Jesse Gross <jesse@nicira.com>,
	Pravin B Shelar <pshelar@nicira.com>,
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	Maciej =?utf-8?Q?=C5=BBenczykowski?= <maze@google.com>,
	David Miller <davem@davemloft.net>
To: Olof Johansson <olof@lixom.net>
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On Wed, May 29, 2013 at 04:02:12PM -0700, Olof Johansson wrote:
> Hi,
> 
> On Wed, May 29, 2013 at 3:54 PM, Simon Horman <horms@verge.net.au> wrote:
> > On Wed, May 29, 2013 at 02:46:05PM -0700, Olof Johansson wrote:
> >> Sorry, that was not a great bug report.
> >>
> >> So, looks like it's the removal of NET_SKBUFF_DATA_USES_OFFSET that
> >> does it for me.
> >>
> >> The devices I've seen it with are with asix usb-ethernet adapters (on
> >> Tegra seaboard) and with mv643xx_eth on cubox (dove).
> >>
> >> I'll try to get a better stacktrace out of it. Simon, maybe you can
> >> reproduce on shmobile hardware?
> >
> > Sure, I will try and reproduce it.
> >
> > I did subsequently post some fixes for fallout resulting from
> > the patch listed below. Those changes are now net-next.
> > Are you seeing the crash with those patches?
> >
> > The fix-up patches are:
> >
> > net,ipv4,ipv6: Correct assignment of skb->network_header to skb->tail
> > sctp: Correct access to skb->{network,transport}_header
> > ipv4: Correct comparisons and calculations using skb->tail and skb-transport_header
> > ipv6: Correct comparisons and calculations using skb->tail and skb-transport_header
> > net: Correct comparisons and calculations using skb->tail and skb-transport_header
> > cxgb3: Correct comparisons and calculations using skb->tail and skb-transport_header
> > isdn: Correct comparison of skb->tail and skb-transport_header
> > net: Fix build warnings after mac_header and transport_header became __u16.
> 
> Ah, no, looks like those didn't make it into the 0529 linux-next.
> 
> I've merged net-next on top and retested, and I no longer see the panics.

Great news, sorry for the mess.

FWIW I did not have any luck reproducing the problem (without the fix-ups)
on the mackerel board.