Date: Mon, 24 Sep 2007 09:43:23 +0200
From: Jarek Poplawski <jarkao2@o2.pl>
To: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
       Alexey Dobriyan <adobriyan@sw.ru>, linux-kernel@vger.kernel.org
Subject: Re: 2.6.23-rc6-mm1: IPC: sleeping function called ...
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On Mon, Sep 24, 2007 at 08:54:07AM +0200, Jarek Poplawski wrote:
> After rethinking, this scenario seems to be wrong or very unprobable
> (I'm not sure of all ways "if (--container...)" could be compiled),
> so there should be no such risk - double kfree/vfree is more probable,
> so no danger. More likely is such refcount abuse: ipc_rcu_getref() in
> do_msgsnd() done a bit after ipc_rcu_putref() in freeque() (msq
> pointer acquired by do_msgsend() before freeque() started); then,
> after schedule(), do_msgsnd() can work with kfreed msq_queue structure
> (at least considering classic RCU).

I see this scenario is even more impossible, so you were right,
it's all right at this point.

Jarek P.
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