From: David Miller <davem@davemloft.net>
To: paulmck@linux.vnet.ibm.com
Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org, jchapman@katalix.com
Subject: Re: [PATCH net-next-2.6] l2tp: fix potential rcu race
Date: Thu, 12 May 2011 17:27:41 -0400 (EDT) [thread overview]
Message-ID: <20110512.172741.1724338998672360298.davem@davemloft.net> (raw)
In-Reply-To: <20110512142641.GO2258@linux.vnet.ibm.com>
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Date: Thu, 12 May 2011 07:26:41 -0700
> On Thu, May 12, 2011 at 06:22:36AM +0200, Eric Dumazet wrote:
>> While trying to remove useless synchronize_rcu() calls, I found l2tp is
>> indeed incorrectly using two of such calls, but also bumps tunnel
>> refcount after list insertion.
>>
>> tunnel refcount must be incremented before being made publically visible
>> by rcu readers.
>>
>> This fix can be applied to 2.6.35+ and might need a backport for older
>> kernels, since things were shuffled in commit fd558d186df2c
>> (l2tp: Split pppol2tp patch into separate l2tp and ppp parts)
>
> Ouch! Good catch, Eric!
>
> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Applied, thanks Eric.
prev parent reply other threads:[~2011-05-12 21:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-12 4:22 [PATCH net-next-2.6] l2tp: fix potential rcu race Eric Dumazet
2011-05-12 14:26 ` Paul E. McKenney
2011-05-12 21:27 ` David Miller [this message]
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