From: Amir Goldstein <amir73il@gmail.com>
To: "Darrick J . Wong" <darrick.wong@oracle.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: [PATCH v3 05/13] vfs: add missing checks to copy_file_range
Date: Wed, 29 May 2019 20:43:09 +0300 [thread overview]
Message-ID: <20190529174318.22424-6-amir73il@gmail.com> (raw)
In-Reply-To: <20190529174318.22424-1-amir73il@gmail.com>
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>
---
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 17:44 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 ` Amir Goldstein [this message]
2019-05-29 18:24 ` [PATCH v3 05/13] vfs: add missing checks to copy_file_range Darrick J. Wong
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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