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From: John Fastabend <john.r.fastabend@intel.com>
To: Gao feng <gaofeng@cn.fujitsu.com>
Cc: davem@davemloft.net, nhorman@tuxdriver.com,
	mark.d.rustad@intel.com, netdev@vger.kernel.org,
	eric.dumazet@gmail.com
Subject: Re: [RFC PATCH] net: cgroup: null ptr dereference in netprio cgroup during init
Date: Tue, 17 Jul 2012 22:50:13 -0700	[thread overview]
Message-ID: <50064E95.7020503@intel.com> (raw)
In-Reply-To: <5006188B.7060606@cn.fujitsu.com>

On 7/17/2012 6:59 PM, Gao feng wrote:
> 于 2012年07月18日 08:33, John Fastabend 写道:
>> When the netprio cgroup is built in the kernel cgroup_init will call
>> cgrp_create which eventually calls update_netdev_tables. This is
>> being called before do_initcalls() so a null ptr dereference occurs
>> on init_net.
>>

[...]

>
>
> Thanks John.
> It's my mistake.
>
> Can we make sure init_net.count is zero here?
> I can't find some places to initialize it to zero.
>

Its defined in net_namespace.c so it's zeroed by virtue
of being global. And initialized in setup_net via
pure_initcall() always after cgroup_init() if I've done
my accounting correctly.

.John

  reply	other threads:[~2012-07-18  5:50 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-18  0:33 [RFC PATCH] net: cgroup: null ptr dereference in netprio cgroup during init John Fastabend
2012-07-18  1:59 ` Gao feng
2012-07-18  5:50   ` John Fastabend [this message]
2012-07-18  7:58     ` Gao feng
2012-07-18 12:45 ` Neil Horman
2012-07-18 14:21   ` John Fastabend
2012-07-18 15:14     ` John Fastabend
2012-07-18 16:50       ` Neil Horman
2012-07-18 17:14       ` Neil Horman
2012-07-18 15:25     ` Neil Horman
2012-07-18 15:53       ` David Miller
2012-07-18 16:37         ` Neil Horman
2012-07-18 16:39           ` David Miller
2012-07-18 16:26 ` David Miller

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