Strengthen the checking of pos/len vs. i_size, clarify the return values
for the clone prep function, and remove pointless code.
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
v2: Minor tweak suggested by Christoph.
---
fs/ocfs2/refcounttree.c | 2 +-
fs/read_write.c | 18 +++++++++++-------
fs/xfs/xfs_reflink.c | 2 +-
3 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index b18465e..21723dd 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4835,7 +4835,7 @@ int ocfs2_reflink_remap_range(struct file *file_in,
ret = vfs_clone_file_prep_inodes(inode_in, pos_in, inode_out, pos_out,
&len, is_dedupe);
- if (ret || len == 0)
+ if (ret <= 0)
goto out_unlock;
/* Lock out changes to the allocation maps and remap. */
diff --git a/fs/read_write.c b/fs/read_write.c
index dbf3f7f..d50828f 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1671,6 +1671,9 @@ static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write)
* Check that the two inodes are eligible for cloning, the ranges make
* sense, and then flush all dirty data. Caller must ensure that the
* inodes have been locked against any other modifications.
+ *
+ * Returns: 0 for "nothing to clone", 1 for "something to clone", or
+ * the usual negative error code.
*/
int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in,
struct inode *inode_out, loff_t pos_out,
@@ -1697,17 +1700,15 @@ int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in,
/* Are we going all the way to the end? */
isize = i_size_read(inode_in);
- if (isize == 0) {
- *len = 0;
+ if (isize == 0)
return 0;
- }
/* Zero length dedupe exits immediately; reflink goes to EOF. */
if (*len == 0) {
- if (is_dedupe) {
- *len = 0;
+ if (is_dedupe || pos_in == isize)
return 0;
- }
+ if (pos_in > isize)
+ return -EINVAL;
*len = isize - pos_in;
}
@@ -1771,7 +1772,7 @@ int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in,
return -EBADE;
}
- return 0;
+ return 1;
}
EXPORT_SYMBOL(vfs_clone_file_prep_inodes);
@@ -1958,6 +1959,9 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
goto out;
ret = 0;
+ if (off + len > i_size_read(src))
+ return -EINVAL;
+
/* pre-format output fields to sane values */
for (i = 0; i < count; i++) {
same->info[i].bytes_deduped = 0ULL;
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 43c0042..2a8ea32 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1215,7 +1215,7 @@ xfs_reflink_remap_range(
ret = vfs_clone_file_prep_inodes(inode_in, pos_in, inode_out, pos_out,
&len, is_dedupe);
- if (ret || len == 0)
+ if (ret <= 0)
goto out_unlock;
trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
--
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