Public bug reported: I have an Ubuntu 08.04.3 NFSv4 server and a number of NFSv4 clients, also running Ubuntu 08.04.3.
The clients use autofs to mount user home directories from the server. I use Kerberos to authenticate the users logging into the clients (using pam_krb5), and require Kerberos authentication of NFS traffic via the sec=krb5 export and mount options. Things seem to work normally on a workstation used by only one user - people can log in, get, valid kerberos tickets from the KDC and their home directory mounts automatically. However, a problem arises on multi-user systems: if one user (say "user A") has successfully logged in and left themselves logged in such that their Kerberos TGT has expired, then a second user ("user B") attempts to log into the same system then the attempt to access the home directory of "user B" blocks indefinately. If "user A" subsequently obtains a new Kerberos TGT then the login attempt belonging to "user B" unblocks and runs to a successful completion. While "B" is blocked, the kernel logs the following error message over and over again, at a very high rate (3000-6000 times a second): Aug 5 11:37:14 ulf kernel: [3099781.024499] Error: state recovery failed on NFSv4 server 163.1.248.155 with error 13 Aug 5 11:37:14 ulf kernel: [3099781.025007] Error: state recovery failed on NFSv4 server 163.1.248.155 with error 13 Aug 5 11:37:14 ulf kernel: [3099781.025483] Error: state recovery failed on NFSv4 server 163.1.248.155 with error 13 The symptoms that I am observing sound exactly like http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=446238 To be clear: I expect user A's access to NFS mounted filesystems to fail when their Kerberos tickets have expired, but I don't expect user B's access to the same filesystems to depend on user A. ProblemType: Bug Architecture: amd64 Date: Wed Aug 5 17:09:42 2009 Dependencies: DistroRelease: Ubuntu 8.04 Package: linux None [modified: /var/lib/dpkg/info/linux.list] PackageArchitecture: amd64 ProcEnviron: PATH=/opt/mricron:/nfs4/willis.dpag.ox.ac.uk/software/unix/matlab/2009a/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin LANG=en_GB.UTF-8 SHELL=/bin/bash SourcePackage: linux-meta Uname: Linux 2.6.24-24-generic x86_64 ** Affects: linux-meta (Ubuntu) Importance: Undecided Status: New ** Tags: apport-bug krb5 nfs4 -- Multi-user sec=krb5 NFSv4 client blocks when one user has an expired ticket https://bugs.launchpad.net/bugs/409438 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs