From: Amir Goldstein <amir73il@gmail.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>,
linux-xfs <linux-xfs@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux Btrfs <linux-btrfs@vger.kernel.org>,
ocfs2-devel@oss.oracle.com, Eric Sandeen <sandeen@redhat.com>
Subject: Re: [PATCH 06/15] vfs: strengthen checking of file range inputs to clone/dedupe range
Date: Fri, 5 Oct 2018 09:10:12 +0300 [thread overview]
Message-ID: <CAOQ4uxiVPvNPxTNZ-njeyte6yk3jo3tjNKv78kS9NqA_Xzxc6g@mail.gmail.com> (raw)
In-Reply-To: <153870031519.29072.18289185889660082318.stgit@magnolia>
On Fri, Oct 5, 2018 at 3:46 AM Darrick J. Wong <darrick.wong@oracle.com> wrote:
>
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> Clone range is an optimization on a regular file write. File writes
> that extend the file length are subject to various constraints which are
> not checked by clonerange. This is a correctness problem, because we're
> never allowed to touch ranges that the page cache can't support
> (s_maxbytes); we're not supposed to deal with large offsets
> (MAX_NON_LFS) if O_LARGEFILE isn't set; and we must obey resource limits
> (RLIMIT_FSIZE).
>
> Therefore, add these checks to the new generic_clone_checks function so
> that we curtail unexpected behavior.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> mm/filemap.c | 31 +++++++++++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
>
>
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 68ec91d05c7b..f74391721234 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -3015,6 +3015,37 @@ int generic_clone_checks(struct file *file_in, loff_t pos_in,
> return -EINVAL;
> count = min(count, size_in - (uint64_t)pos_in);
>
> + /* Don't exceed RLMIT_FSIZE in the file we're writing into. */
> + if (limit != RLIM_INFINITY) {
> + if (pos_out >= limit) {
> + send_sig(SIGXFSZ, current, 0);
> + return -EFBIG;
> + }
> + count = min(count, limit - (uint64_t)pos_out);
> + }
> +
> + /* Don't exceed the LFS limits. */
> + if (unlikely(pos_out + count > MAX_NON_LFS &&
> + !(file_out->f_flags & O_LARGEFILE))) {
> + if (pos_out >= MAX_NON_LFS)
> + return -EFBIG;
> + count = min(count, MAX_NON_LFS - (uint64_t)pos_out);
> + }
> + if (unlikely(pos_in + count > MAX_NON_LFS &&
> + !(file_in->f_flags & O_LARGEFILE))) {
> + if (pos_in >= MAX_NON_LFS)
> + return -EFBIG;
> + count = min(count, MAX_NON_LFS - (uint64_t)pos_in);
> + }
> +
> + /* Don't operate on ranges the page cache doesn't support. */
> + if (unlikely(pos_out >= inode_out->i_sb->s_maxbytes ||
> + pos_in >= inode_in->i_sb->s_maxbytes))
> + return -EFBIG;
> +
Forget my standards, this doesn't abide by your own standards ;-)
Please factor out generic_write_checks() and use it instead of
duplicating the code. The in/out variant doesn't justify not calling
the helper twice IMO.
Thanks,
Amir.
next prev parent reply other threads:[~2018-10-05 13:07 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-05 0:44 [PATCH 00/15] fs: fixes for serious clone/dedupe problems Darrick J. Wong
2018-10-05 0:44 ` [PATCH 01/15] xfs: add a per-xfs trace_printk macro Darrick J. Wong
2018-10-05 0:44 ` [PATCH 02/15] xfs: refactor clonerange preparation into a separate helper Darrick J. Wong
2018-10-05 5:28 ` Dave Chinner
2018-10-05 17:06 ` Darrick J. Wong
2018-10-06 10:30 ` Christoph Hellwig
2018-10-05 7:02 ` Dave Chinner
2018-10-05 9:02 ` Dave Chinner
2018-10-05 17:21 ` Darrick J. Wong
2018-10-05 23:42 ` Dave Chinner
2018-10-05 0:44 ` [PATCH 03/15] xfs: zero posteof blocks when cloning above eof Darrick J. Wong
2018-10-05 5:28 ` Dave Chinner
2018-10-06 10:34 ` Christoph Hellwig
2018-10-05 0:45 ` [PATCH 04/15] xfs: update ctime and remove suid before cloning files Darrick J. Wong
2018-10-05 5:30 ` Dave Chinner
2018-10-06 10:35 ` Christoph Hellwig
2018-10-05 0:45 ` [PATCH 05/15] vfs: check file ranges " Darrick J. Wong
2018-10-06 10:38 ` Christoph Hellwig
2018-10-05 0:45 ` [PATCH 06/15] vfs: strengthen checking of file range inputs to clone/dedupe range Darrick J. Wong
2018-10-05 6:10 ` Amir Goldstein [this message]
2018-10-05 17:36 ` Darrick J. Wong
2018-10-05 0:45 ` [PATCH 07/15] vfs: skip zero-length dedupe requests Darrick J. Wong
2018-10-05 8:39 ` Amir Goldstein
2018-10-06 10:39 ` Christoph Hellwig
2018-10-05 0:45 ` [PATCH 08/15] vfs: change clone and dedupe range function pointers to return bytes completed Darrick J. Wong
2018-10-05 8:06 ` Amir Goldstein
2018-10-05 21:47 ` Darrick J. Wong
2018-10-06 10:41 ` Christoph Hellwig
2018-10-08 18:59 ` Darrick J. Wong
2018-10-05 0:45 ` [PATCH 09/15] vfs: pass operation flags to {clone, dedupe}_file_range implementations Darrick J. Wong
2018-10-05 7:07 ` Amir Goldstein
2018-10-05 17:50 ` Darrick J. Wong
2018-10-06 10:44 ` Christoph Hellwig
2018-10-05 0:45 ` [PATCH 10/15] vfs: make cloning to source file eof more explicit Darrick J. Wong
2018-10-05 6:47 ` Amir Goldstein
2018-10-05 0:45 ` [PATCH 11/15] vfs: allow short clone and dedupe operations Darrick J. Wong
2018-10-05 0:46 ` [PATCH 12/15] vfs: implement opportunistic short dedupe Darrick J. Wong
2018-10-05 6:40 ` Amir Goldstein
2018-10-05 17:42 ` Darrick J. Wong
2018-10-05 0:46 ` [PATCH 13/15] ocfs2: truncate page cache for clone destination file before remapping Darrick J. Wong
2018-10-05 0:46 ` [PATCH 14/15] ocfs2: support partial clone range and dedupe range Darrick J. Wong
2018-10-05 0:46 ` [PATCH 15/15] xfs: support returning partial reflink results Darrick J. Wong
2018-10-05 1:17 ` [PATCH 00/15] fs: fixes for serious clone/dedupe problems Dave Chinner
2018-10-05 1:24 ` Darrick J. Wong
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