From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Amir Goldstein <amir73il@gmail.com>
Cc: 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, Dave Chinner <dchinner@redhat.com>
Subject: Re: [PATCH v3 05/13] vfs: add missing checks to copy_file_range
Date: Wed, 29 May 2019 11:24:47 -0700 [thread overview]
Message-ID: <20190529182447.GE5231@magnolia> (raw)
In-Reply-To: <20190529174318.22424-6-amir73il@gmail.com>
On Wed, May 29, 2019 at 08:43:09PM +0300, Amir Goldstein wrote:
> Like the clone and dedupe interfaces we've recently fixed, the
> copy_file_range() implementation is missing basic sanity, limits and
> boundary condition tests on the parameters that are passed to it
> from userspace. Create a new "generic_copy_file_checks()" function
> modelled on the generic_remap_checks() function to provide this
> missing functionality.
>
> [Amir] Shorten copy length instead of checking pos_in limits
> because input file size already abides by the limits.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
--D
> ---
> fs/read_write.c | 3 ++-
> include/linux/fs.h | 3 +++
> mm/filemap.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 58 insertions(+), 1 deletion(-)
>
> diff --git a/fs/read_write.c b/fs/read_write.c
> index f1900bdb3127..b0fb1176b628 100644
> --- a/fs/read_write.c
> +++ b/fs/read_write.c
> @@ -1626,7 +1626,8 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
> if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
> return -EXDEV;
>
> - ret = generic_file_rw_checks(file_in, file_out);
> + ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len,
> + flags);
> if (unlikely(ret))
> return ret;
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 89b9b73eb581..e4d382c4342a 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -3050,6 +3050,9 @@ extern int generic_remap_checks(struct file *file_in, loff_t pos_in,
> struct file *file_out, loff_t pos_out,
> loff_t *count, unsigned int remap_flags);
> extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
> +extern int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
> + struct file *file_out, loff_t pos_out,
> + size_t *count, unsigned int flags);
> extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
> extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
> extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 44361928bbb0..aac71aef4c61 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -3056,6 +3056,59 @@ int generic_file_rw_checks(struct file *file_in, struct file *file_out)
> return 0;
> }
>
> +/*
> + * Performs necessary checks before doing a file copy
> + *
> + * Can adjust amount of bytes to copy via @req_count argument.
> + * Returns appropriate error code that caller should return or
> + * zero in case the copy should be allowed.
> + */
> +int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
> + struct file *file_out, loff_t pos_out,
> + size_t *req_count, unsigned int flags)
> +{
> + struct inode *inode_in = file_inode(file_in);
> + struct inode *inode_out = file_inode(file_out);
> + uint64_t count = *req_count;
> + loff_t size_in;
> + int ret;
> +
> + ret = generic_file_rw_checks(file_in, file_out);
> + if (ret)
> + return ret;
> +
> + /* Don't touch certain kinds of inodes */
> + if (IS_IMMUTABLE(inode_out))
> + return -EPERM;
> +
> + if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
> + return -ETXTBSY;
> +
> + /* Ensure offsets don't wrap. */
> + if (pos_in + count < pos_in || pos_out + count < pos_out)
> + return -EOVERFLOW;
> +
> + /* Shorten the copy to EOF */
> + size_in = i_size_read(inode_in);
> + if (pos_in >= size_in)
> + count = 0;
> + else
> + count = min(count, size_in - (uint64_t)pos_in);
> +
> + ret = generic_write_check_limits(file_out, pos_out, &count);
> + if (ret)
> + return ret;
> +
> + /* Don't allow overlapped copying within the same file. */
> + if (inode_in == inode_out &&
> + pos_out + count > pos_in &&
> + pos_out < pos_in + count)
> + return -EINVAL;
> +
> + *req_count = count;
> + return 0;
> +}
> +
> int pagecache_write_begin(struct file *file, struct address_space *mapping,
> loff_t pos, unsigned len, unsigned flags,
> struct page **pagep, void **fsdata)
> --
> 2.17.1
>
next prev parent reply other threads:[~2019-05-29 18:25 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-29 17:43 [PATCH v3 00/13] Fixes for major copy_file_range() issues Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 01/13] vfs: introduce generic_copy_file_range() Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 02/13] vfs: no fallback for ->copy_file_range Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 03/13] vfs: introduce generic_file_rw_checks() Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 04/13] vfs: remove redundant checks from generic_remap_checks() Amir Goldstein
2019-05-29 18:23 ` Darrick J. Wong
2019-05-29 17:43 ` [PATCH v3 05/13] vfs: add missing checks to copy_file_range Amir Goldstein
2019-05-29 18:24 ` Darrick J. Wong [this message]
2019-05-29 17:43 ` [PATCH v3 06/13] vfs: introduce file_modified() helper Amir Goldstein
2019-05-29 18:27 ` Darrick J. Wong
2019-05-29 19:08 ` Amir Goldstein
2019-05-29 19:23 ` Amir Goldstein
2019-05-29 21:41 ` Dave Chinner
2019-05-29 17:43 ` [PATCH v3 07/13] xfs: use " Amir Goldstein
2019-05-29 18:31 ` Darrick J. Wong
2019-05-29 19:10 ` Amir Goldstein
2019-05-29 19:13 ` Darrick J. Wong
2019-05-29 17:43 ` [PATCH v3 08/13] vfs: copy_file_range needs to strip setuid bits and update timestamps Amir Goldstein
2019-05-29 18:33 ` Darrick J. Wong
2019-05-29 21:08 ` Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 09/13] ceph: " Amir Goldstein
2019-05-29 19:43 ` Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 10/13] cifs: " Amir Goldstein
2019-05-29 19:36 ` Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 11/13] fuse: " Amir Goldstein
2019-05-29 19:37 ` Amir Goldstein
2019-05-29 20:07 ` Miklos Szeredi
2019-05-29 17:43 ` [PATCH v3 12/13] nfs: " Amir Goldstein
2019-05-29 19:34 ` Amir Goldstein
2019-05-29 20:02 ` Trond Myklebust
2019-05-29 21:00 ` Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 13/13] vfs: allow copy_file_range to copy across devices Amir Goldstein
2019-05-29 20:09 ` Olga Kornievskaia
2019-05-29 21:03 ` Amir Goldstein
2019-06-03 20:39 ` Olga Kornievskaia
2019-06-04 4:11 ` Amir Goldstein
2019-05-29 17:43 ` [PATCH v3 14/13] man-pages: copy_file_range updates Amir Goldstein
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