4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Amir Goldstein <amir73il@xxxxxxxxx>
commit 11cbfb10775aa2a01cee966d118049ede9d0bdf2 upstream.
There is no in-tree file system that implements copy_file_range()
for non regular files.
Deny an attempt to copy_file_range() a directory with EISDIR
and any other non regualr file with EINVAL to conform with
behavior of vfs_{clone,dedup}_file_range().
This change is needed prior to converting sb_start_write()
to file_start_write() in the vfs helper.
Cc: linux-api@xxxxxxxxxxxxxxx
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/read_write.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1518,6 +1518,11 @@ ssize_t vfs_copy_file_range(struct file
if (flags != 0)
return -EINVAL;
+ if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
+ return -EISDIR;
+ if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
+ return -EINVAL;
+
ret = rw_verify_area(READ, file_in, &pos_in, len);
if (unlikely(ret))
return ret;