On 11/11/2014 07:50 AM, Jakob Blomer wrote:
> Dear Scientific Linux team,
>
> the latest kernel 2.6.32-504 crashes if a fuse file system is accessed
> from within the kernel space.  As discovered by Simon, this happens for
> instance when a fuse file system is re-exported via NFS.  When it
> happens, the stack trace starts with
>
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
> IP: [<ffffffffa0202260>] fuse_dentry_revalidate+0xf0/0x400 [fuse]
>
>
> The behavior was not present with the previous kernel 2.6.32-431.29.2.
> Besides security patches, the latest kernel seems to also backport new
> fuse features which triggers the problem.  As a workaround, we managed
> to avoid the problem with a small kernel patch [1].
>
> Could you report the problem back to Redhat?  If necessary, I can
> provide detailed steps how to reproduce it.
>
> Cheers,
> Jakob
>
>
> [1]
> https://raw.githubusercontent.com/cvmfs/aufs2-standalone/aufs2.1-32-rhel6.6/rhel6.6-fuse.patch

If we can get some more detailed replication steps it should help get 
the issue clearly explained to upstream.

Do you have a bugzilla account?

Pat

-- 
Pat Riehecky

Scientific Linux developer
http://www.scientificlinux.org/