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From: Benjamin LaHaise <bcrl@kvack.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dan Aloni <dan@kernelim.com>,
	"security@kernel.org" <security@kernel.org>,
	linux-aio@kvack.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Mateusz Guzik <mguzik@redhat.com>,
	Petr Matousek <pmatouse@redhat.com>,
	Kent Overstreet <kmo@daterainc.com>,
	Jeff Moyer <jmoyer@redhat.com>, stable <stable@vger.kernel.org>
Subject: Re: Revert "aio: fix aio request leak when events are reaped by user space"
Date: Sun, 24 Aug 2014 14:11:40 -0400	[thread overview]
Message-ID: <20140824181140.GD4376@kvack.org> (raw)
In-Reply-To: <CA+55aFzZbRkEh_MbB-XmurVP-4seMP3z9tbq+YQOhkjtDNTzfg@mail.gmail.com>

On Fri, Aug 22, 2014 at 02:43:56PM -0700, Linus Torvalds wrote:
> Ugh.
> 
> Ben, at this point my gut feel is that we should just revert the
> original "fix", and you should take a much deeper look at this all.
> The original "fix" was more broken then the leak it purported to fix,
> and now the patch to fix your fix has gone through two iterations and
> *still* Dan is finding bugs in it.  I'm getting the feeling that this
> code needs more thinking than you are actually putting into it.

That's why I had't sent it out as an official [PATCH] just yet.  I think 
things worked out okay since the untested patch I sent out pointed Dan in 
the right direction and he was able to put some effort into it while I 
didn't have to immediate time to do so.  I just put in a few hours to 
polish off the final details on this fix now, and it should be coming your 
way as soon as I get an ack back from Dan.  Hopefully Kent can review it 
as well, since I had to modify the approach to try to retain the advantages 
of his batched reqs_available handling and avoid bouncing the cacheline 
ctx->completion_lock is on during io_submit().  Cheers,

		-ben

>                 Linus

-- 
"Thought is the essence of where you are now."

  reply	other threads:[~2014-08-24 18:11 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-24 18:01 [PATCH 0/2] aio: fixes for kernel memory disclosure in aio read events Benjamin LaHaise
2014-06-24 18:01 ` [PATCH 1/2] aio: fix aio request leak when events are reaped by userspace Benjamin LaHaise
2014-06-24 18:20   ` Jeff Moyer
2014-08-19 16:37   ` Revert "aio: fix aio request leak when events are reaped by user space" Dan Aloni
2014-08-19 16:54     ` Benjamin LaHaise
2014-08-19 17:14       ` Dan Aloni
2014-08-20  0:46         ` Benjamin LaHaise
2014-08-22 16:01           ` Benjamin LaHaise
2014-08-22 16:15             ` Dan Aloni
2014-08-22 16:26               ` Benjamin LaHaise
2014-08-22 18:51                 ` Dan Aloni
2014-08-22 21:43                   ` Linus Torvalds
2014-08-24 18:11                     ` Benjamin LaHaise [this message]
2014-08-26  1:11                     ` Kent Overstreet
2014-08-24 18:05                   ` Benjamin LaHaise
2014-08-24 18:48                     ` Dan Aloni
2014-08-27 20:26                       ` Jeff Moyer
2014-08-25 15:06                 ` Elliott, Robert (Server Storage)
2014-08-25 15:11                   ` Benjamin LaHaise
2014-06-24 18:02 ` [PATCH 2/2] aio: fix kernel memory disclosure in io_getevents() introduced in v3.10 Benjamin LaHaise
2014-06-24 18:23   ` Jeff Moyer
2014-06-24 18:39     ` Benjamin LaHaise
2014-06-24 19:21       ` Jeff Moyer

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