From: "Theodore Ts'o" <tytso@mit.edu>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Amir Goldstein <amir73il@gmail.com>,
Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@lst.de>,
linux-xfs@vger.kernel.org,
Olga Kornievskaia <olga.kornievskaia@gmail.com>,
Luis Henriques <lhenriques@suse.com>,
Al Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
ceph-devel@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-cifs@vger.kernel.org
Subject: Re: [PATCH] vfs: allow copy_file_range from a swapfile
Date: Mon, 10 Jun 2019 22:51:08 -0400 [thread overview]
Message-ID: <20190611025108.GB2774@mit.edu> (raw)
In-Reply-To: <20190611011612.GQ1871505@magnolia>
On Mon, Jun 10, 2019 at 06:16:12PM -0700, Darrick J. Wong wrote:
> On Mon, Jun 10, 2019 at 08:26:06PM +0300, Amir Goldstein wrote:
> > read(2) is allowed from a swapfile, so copy_file_range(2) should
> > be allowed as well.
> >
> > Reported-by: Theodore Ts'o <tytso@mit.edu>
> > Fixes: 96e6e8f4a68d ("vfs: add missing checks to copy_file_range")
> > Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> > ---
> >
> > Darrick,
> >
> > This fixes the generic/554 issue reported by Ted.
>
> Frankly I think we should go the other way -- non-root doesn't get to
> copy from or read from swap files.
The issue is that without this patch, *root* doesn't get to copy from
swap files. Non-root shouldn't have access via Unix permissions. We
could add a special case if we don't trust system administrators to be
able to set the Unix permissions correctly, I suppose, but we don't do
that for block devices when they are mounted....
- Ted
next prev parent reply other threads:[~2019-06-11 2:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-10 17:26 [PATCH] vfs: allow copy_file_range from a swapfile Amir Goldstein
2019-06-11 1:16 ` Darrick J. Wong
2019-06-11 2:51 ` Theodore Ts'o [this message]
2019-06-11 3:29 ` Darrick J. Wong
2019-06-11 5:08 ` Christoph Hellwig
2019-06-11 5:44 ` Amir Goldstein
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