Two remarks.
1) you show a # as prompt in your examples. That means that you are already root. No need to do a sudo.
2) when doing an ls on a file and getting "permission denied" that means that you have no permission to read the
directory that contains the file, it is not about the file itself. Better information for us would have been to show (as root):
Code:
ls -d <the-absolute-path-to-the-dir-involved>
ls -l <the-absolute-path-to-the-dir-involved>
ls -l <the-absolute-path-to-the-dir-involved>/<one-of-the-files-involved>
and then cut/paste that
completely in your post (preferable within CODE tags).