From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>,
torvalds@linux-foundation.org, jack@suse.cz,
dmonakhov@openvz.org, jmoyer@redhat.com,
linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] aio: fix a user triggered use after free (and fix freeze protection of aio writes)
Date: Sat, 29 Oct 2016 17:20:17 +0200 [thread overview]
Message-ID: <20161029152017.GA7388@lst.de> (raw)
In-Reply-To: <20161029122451.GQ19539@ZenIV.linux.org.uk>
On Sat, Oct 29, 2016 at 01:24:51PM +0100, Al Viro wrote:
> How about taking this chunk (i.e. telling lockdep that we are not holding this
> thing) past the iter_op() call, where file_end_write() used to be?
We can't as that would not fix the use after free (at least for the lockdep
case - otherwise the call is a no-op). Once iter_op returns aio_complete
might have dropped our reference to the file, and another thread might
have closed the fd so that the fput from aio_complete was the last one.
This is something that xfstests/323 can reproduce under the right conditions.
next prev parent reply other threads:[~2016-10-29 15:20 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1477727070-18806-1-git-send-email-hch@lst.de>
2016-10-29 7:44 ` [PATCH] aio: fix a user triggered use after free (and fix freeze protection of aio writes) Christoph Hellwig
2016-10-29 12:24 ` Al Viro
2016-10-29 15:20 ` Christoph Hellwig [this message]
2016-10-29 16:12 ` Al Viro
2016-10-29 16:29 ` Al Viro
2016-10-30 6:32 ` Christoph Hellwig
2016-10-29 17:47 ` Linus Torvalds
2016-10-29 18:52 ` Al Viro
2016-10-29 19:07 ` Linus Torvalds
2016-10-29 19:17 ` Al Viro
2016-10-29 20:09 ` Linus Torvalds
2016-10-30 9:44 ` Jan Kara
2016-10-30 10:52 ` Jan Kara
2016-10-30 15:58 ` Christoph Hellwig
2016-10-30 6:29 ` Christoph Hellwig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20161029152017.GA7388@lst.de \
--to=hch@lst.de \
--cc=dmonakhov@openvz.org \
--cc=jack@suse.cz \
--cc=jmoyer@redhat.com \
--cc=linux-aio@kvack.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=viro@ZenIV.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).