Hi Pat, thanks for the quick reply! I just created a bugzilla account. The best I can provide quickly uses the cvmfs file system, which is not in the standard repositories but it is a normal fuse module. On the NFS server side: o) Install cvmfs: yum install https://ecsft.cern.ch/dist/cvmfs/cvmfs-release/cvmfs-release-2-4.el6.noarch.rpm yum install cvmfs o) Configure and mount cvmfs echo 'CVMFS_HTTP_PROXY=DIRECT' > /etc/cvmfs/default.local echo 'CVMFS_NFS_SOURCE=yes' >> /etc/cvmfs/default.local mkdir /mnt/cvmfs mount -t cvmfs grid.cern.ch /mnt/cvmfs o) Export via NFS echo '/mnt/cvmfs *(ro,fsid=1)' > /etc/exports exportfs -ra On the NFS client side: mkdir /mnt/nfs mount <SERVER>:/mnt/cvmfs /mnt/nfs ls /mnt/nfs # Server crashes Let me see if I can produce something similar with a fuse module that comes in the normal repository. Cheers, Jakob On 11/11/14 15:23, Pat Riehecky wrote: > 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 >