AW: Re: ext3 Filessyten in FC5-Test incompatible with other FC or RHEL versions

[Stephen Smalley]

On Thu, 2005-12-22 at 12:10 +0100, gsc.news at online.de wrote:
> >
> >On Thu, 2005-12-22 at 07:24 +0100, "Dr. Günter Schmidt" wrote:
> >> 
> >> I have a multi boot system with FC5-TEST, FC3, RH9 and Centos4 (RHEL4
> >> clone).
> >> The /boot and /home are common to all OS's. Since I installed FC5 I can
> >> not access anymore
> >> the common partitions if I boot into the older systems.
> >> Is there any solution to that problem.
> >
> >Could it be SELinux tagging?  Using SELinux on the file system then
> >booting to an older distro that doesn't have SELinux enabled?
> 
> This may be possible for RH9 but not Cento4, there is SELinux enabled too.
> 
> I tried to disable SELinux and convert the partions back to ext2 but the message
> during boot is still the same:
> mount: wrong fs type, bad option, bad superblock on /dev/hda2
> (which is my boot partition).

In FC5, the security contexts have been extended with an additional
field for the Multi-Category Security (MCS) and Multi-Level Security
(MLS) support, see
http://www.livejournal.com/users/james_morris/5583.html
and
http://www.livejournal.com/users/james_morris/5020.html

Older SELinux kernels with MLS support disabled (i.e. RHEL4/CentOS4,
FC3, older FC4 kernels) will reject the extended security contexts as
being invalid, which yields the error you are seeing.  Some
compatibility patches were upstreamed to help with this problem, and I
think that they went into the latest FC4 kernel update, but I'm not sure
about RHEL4 yet.

On the RH9 side, you are likely running into the old xattr-on-symlinks
problem in older 2.4 kernels; the fix for that problem was backported to
a FC1 kernel update long ago, IIRC, but naturally not to RH9.

-- 
Stephen Smalley
National Security Agency