From: Benjamin LaHaise <bcrl@kvack.org>
To: Dan Aloni <dan@kernelim.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
security@kernel.org, linux-aio@kvack.org,
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@vger.kernel.org
Subject: Re: Revert "aio: fix aio request leak when events are reaped by user space"
Date: Tue, 19 Aug 2014 12:54:04 -0400 [thread overview]
Message-ID: <20140819165404.GD13858@kvack.org> (raw)
In-Reply-To: <20140819163733.GA10132@gmail.com>
On Tue, Aug 19, 2014 at 07:37:33PM +0300, Dan Aloni wrote:
> Some testing I've done today indicates that the original commit broke
> AIO with regard to users that overflow the maximum number of request
> per IO context (where -EAGAIN is returned).
>
> In fact, it did worse - the attached C program can easily overrun the
> ring buffer that is responsible for managing the completed requests,
> and caused notification about their completion never to be returned.
Argh, that would be a problem.
...
> This reverts commit b34e0e1319b31202eb142dcd9688cf7145a30bf6.
Reverting isn't okay, as that reintroduces another regression. We need
to come up with a fix for this issue that doesn't reintroduce the other
regression for events reaped in user space. Let me have a look and see
what I can come up with...
-ben
--
"Thought is the essence of where you are now."
next prev parent reply other threads:[~2014-08-19 16:54 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 [this message]
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
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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