From: Al Viro <viro@ZenIV.linux.org.uk>
To: Christoph Hellwig <hch@lst.de>
Cc: 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 13:24:51 +0100 [thread overview]
Message-ID: <20161029122451.GQ19539@ZenIV.linux.org.uk> (raw)
In-Reply-To: <1477727070-18806-2-git-send-email-hch@lst.de>
On Sat, Oct 29, 2016 at 09:44:29AM +0200, Christoph Hellwig wrote:
> - if (rw == WRITE)
> + if (rw == WRITE) {
> file_start_write(file);
> + req->ki_flags |= IOCB_WRITE;
> + }
> + if (rw == WRITE) {
> + /*
> + * We release freeze protection in aio_complete(). Fool
> + * lockdep by telling it the lock got released so that
> + * it doesn't complain about held lock when we return
> + * to userspace.
> + */
> + __sb_writers_release(file_inode(file)->i_sb,
> + SB_FREEZE_WRITE);
> + }
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?
As it is, you risk hiding the lock dependencies the current mainline would've
caught. Other than that I see no problems with the patch...
next prev parent reply other threads:[~2016-10-29 12:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-29 7:44 aio: fix a user triggered use after free Christoph Hellwig
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 [this message]
2016-10-29 15:20 ` Christoph Hellwig
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=20161029122451.GQ19539@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=dmonakhov@openvz.org \
--cc=hch@lst.de \
--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 \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.