CRAMFS error "attempt to access beyond end of device"

[Sidik Isani]

Hello -

  Is there maybe a missing boundary check in cramfs that causes
  accesses slightly past (up to 24 or 32K?) the end of a device?
  Here's an example of a cramfs image mounted on a loop device
  (the same thing happens with other block devices, and when the
  kernel itself mounts a partition as cramfs-root.)

attempt to access beyond end of device
07:01: rw=0, want=1156, limit=1152
attempt to access beyond end of device
07:01: rw=0, want=1160, limit=1152
attempt to access beyond end of device
07:01: rw=0, want=1164, limit=1152

  The messages appear while running "diff -r" against the original tree.
  The diff itself doesn't find any problems with the filesystem.
  The size of the cramfs is 1179648 bytes, or exactly 1152 * 1024.
  My kernel version is 2.4.5, but this behavior has existed since
  the 2.4.0-test kernels.

  If anyone has ideas on this, please let me know.

- Sidik