From: Eric Dumazet <erdnetdev@gmail.com>
To: Ben Hutchings <bhutchings@solarflare.com>
Cc: Tom Parkin <tparkin@katalix.com>,
David Miller <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>
Subject: Re: NULL pointer dereference in veth_stats_one
Date: Fri, 04 Jan 2013 11:23:26 -0800 [thread overview]
Message-ID: <1357327406.1678.2139.camel@edumazet-glaptop> (raw)
In-Reply-To: <1357323443.2693.9.camel@bwh-desktop.uk.solarflarecom.com>
On Fri, 2013-01-04 at 18:17 +0000, Ben Hutchings wrote:
> This possibly needs some memory barriers to properly synchronise with
> veth_newlink(). But can you not move initialisation of the peer
> pointers before registration of the devices in veth_newlink(), so that
> veth_get_stats64() cannot be called before they are initialised?
The ->peer pointer cannot change once set. ( its never cleared )
So the problem would not be in veth_newlink(), but might be in
veth_dellink()
It seems we would have a problem in veth_get_ethtool_stats() already...
More generally, what prevents a get_stats() being called while a
dellink() (-> veth_dev_free() -> free_percpu()) is done ?
(Same thing is done for tunnel/dummy stats percpu data)
next prev parent reply other threads:[~2013-01-04 19:23 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-04 10:59 NULL pointer dereference in veth_stats_one Tom Parkin
2013-01-04 15:45 ` Eric Dumazet
2013-01-04 16:17 ` Eric Dumazet
2013-01-04 18:17 ` Ben Hutchings
2013-01-04 19:23 ` Eric Dumazet [this message]
2013-01-04 20:25 ` Ben Hutchings
2013-01-05 1:42 ` Eric Dumazet
2013-01-08 3:43 ` David Miller
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