Upstream bug: 1162782 I've added Jakob to the watch list, I can add others if you ask. TUV makes kernel bugs private by default. Pat On 11/11/2014 09:52 AM, Jakob Blomer wrote: > Hi Pat, > > I found similar steps with ntfs-3g: > > On the server side: > # Create volume and a file > dd if=/dev/zero of=ntfs-volume bs=1024 count=$((10*1024)) > mkfs.ntfs -F ntfs-volume > mkdir /mnt/ntfs > ntfs-3g ntfs-volume /mnt/ntfs > echo foo > /mnt/ntfs/foo > > # Remount > umount /mnt/ntfs > ntfs-3g ntfs-volume /mnt/ntfs > > # Export > echo '/mnt/ntfs *(fsid=1)' > /etc/exports > exportfs -a > > > On the client side > mkdir /mnt/nfs > mount <SERVER>:/mnt/ntfs /mnt/nfs > find /mnt/nfs -exec cat {} \; # <-- Server crashes > > Cheers, > Jakob > > > On 11/11/14 16:36, Jakob Blomer wrote: >> 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 >>> -- Pat Riehecky Scientific Linux developer http://www.scientificlinux.org/