From: Al Viro <viro@ZenIV.linux.org.uk>
To: Christoph Hellwig <hch@lst.de>
Cc: Avi Kivity <avi@scylladb.com>,
linux-aio@kvack.org, linux-fsdevel@vger.kernel.org,
linux-api@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/6] aio: refactor read/write iocb setup
Date: Fri, 6 Apr 2018 13:28:48 +0100 [thread overview]
Message-ID: <20180406122848.GA30522@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20180406071011.GA21308@lst.de>
On Fri, Apr 06, 2018 at 09:10:11AM +0200, Christoph Hellwig wrote:
> On Fri, Apr 06, 2018 at 04:21:46AM +0100, Al Viro wrote:
> > On Wed, Mar 28, 2018 at 09:26:36AM +0200, Christoph Hellwig wrote:
> > > + struct inode *inode = file_inode(file);
> > > +
> > > req->ki_flags |= IOCB_WRITE;
> > > file_start_write(file);
> > > - ret = aio_ret(req, call_write_iter(file, req, &iter));
> > > + ret = aio_rw_ret(req, call_write_iter(file, req, &iter));
> > > /*
> > > - * 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.
> > > + * We release freeze protection in aio_complete_rw(). Fool
> > > + * lockdep by telling it the lock got released so that it
> > > + * doesn't complain about held lock when we return to userspace.
> > > */
> > > - if (S_ISREG(file_inode(file)->i_mode))
> > > - __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
> > > + if (S_ISREG(inode->i_mode))
> >
> > ... and that's another use-after-free, since we might've already done fput() of
> > that sucker by that point.
>
> Indeed. Not in any way new in this patch, this is an existing issue
> dating way back that needs to be fixed, which will be rather annoying
> without taking an extra reference to the inode or at least sb.
New, actually - mainline has get_file()/fput() around the equivalent area.
next prev parent reply other threads:[~2018-04-06 12:28 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-28 7:26 io_pgetevents & aio fsync V2 Christoph Hellwig
2018-03-28 7:26 ` [PATCH 1/6] aio: don't print the page size at boot time Christoph Hellwig
2018-03-28 7:26 ` [PATCH 2/6] aio: remove an outdated comment in aio_complete Christoph Hellwig
2018-03-28 16:05 ` Darrick J. Wong
2018-03-28 17:05 ` Matthew Wilcox
2018-03-28 7:26 ` [PATCH 3/6] aio: refactor read/write iocb setup Christoph Hellwig
2018-04-06 3:21 ` Al Viro
2018-04-06 7:10 ` Christoph Hellwig
2018-04-06 12:28 ` Al Viro [this message]
2018-03-28 7:26 ` [PATCH 4/6] aio: sanitize ki_list handling Christoph Hellwig
2018-03-28 7:26 ` [PATCH 5/6] aio: implement IOCB_CMD_FSYNC and IOCB_CMD_FDSYNC Christoph Hellwig
2018-04-06 2:59 ` Al Viro
2018-03-28 7:26 ` [PATCH 6/6] aio: implement io_pgetevents Christoph Hellwig
2018-04-06 3:16 ` io_pgetevents & aio fsync V2 Al Viro
2018-04-06 6:27 ` Christoph Hellwig
2018-04-06 12:57 ` Jeff Moyer
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