[PATCH 4.4 123/137] ovl: allow zero size xattr

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <miklos@szeredi.hu>

commit 97daf8b97ad6f913a34c82515be64dc9ac08d63e upstream.

When ovl_copy_xattr() encountered a zero size xattr no more xattrs were
copied and the function returned success.  This is clearly not the desired
behavior.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/overlayfs/copy_up.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c

@@ -54,7 +54,7 @@ int ovl_copy_xattr(struct dentry *old, s
 
 	for (name = buf; name < (buf + list_size); name += strlen(name) + 1) {
 		size = vfs_getxattr(old, name, value, XATTR_SIZE_MAX);
-		if (size <= 0) {
+		if (size < 0) {
 			error = size;
 			goto out_free_value;
 		}