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From: Kristian Nielsen <knielsen@knielsen-hq.org>
To: Gu Zheng <guz.fnst@cn.fujitsu.com>
Cc: Dave Jones <davej@redhat.com>, Benjamin LaHaise <bcrl@kvack.org>,
        Kent Overstreet <kmo@daterainc.com>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        Sasha Levin <sasha.levin@oracle.com>
Subject: Re: GPF in aio_migratepage
References: <20131126032645.GA32301@redhat.com>
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Date: Sun, 22 Dec 2013 21:44:45 +0100
In-Reply-To: <52AE6C4A.9080203@cn.fujitsu.com> (Gu Zheng's message of "Mon, 16
	Dec 2013 10:58:18 +0800")
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Gu Zheng <guz.fnst@cn.fujitsu.com> writes:

> This issue seems like a problem that has been fixed yet:
> http://article.gmane.org/gmane.linux.kernel.aio.general/3741/match=potential+use+after+free+aio%5fmigratepage
> commit 5e9ae2e5da0beb93f8557fc92a8f4fbc05ea448f
> aio: fix use-after-free in aio_migratepage
> So I think maybe you can run with latest Linus' tree or 3.13-rc4 to
> check whether this issue still appears.

Hm. I checked that thread, and as far as I can see, that patch was already
included in the tree I hit the BUG in (3.13-rc1):

    http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=5e9ae2e5da0beb93f8557fc92a8f4fbc05ea448f

There are other changes in that area since 3.13-rc1 though.

Anyway, I am now running with 3.13-rc4 and will report if I see anything.
Given that I do not have any way to reproduce (I only ever saw this once),
this seems the best that can be done for now.

Thanks for following up on this!

 - Kristian.