Subject: ANNOUNCE: nfs-utils 1.0.4
To: nfs@lists.sourceforge.net, linux-kernel@vger.kernel.org
cc: Janusz Niewiadomski <funkysh@isec.pl>

This release of nfs-utils contains:

 1/ Fix for a remotely exploitable buffer-overflow bug.
 2/ assorted minor bug fixes
 3/ Extensive changes to make use of new functionality in linux-2.6.0 nfsd

nfs-utils 1.0.4 can be downloaded from 
  http://sourceforge.net/project/showfiles.php?group_id=14
or
  http://www.{countrycode}.kernel.org/pub/linux/utils/nfs/

I consider this release to be a pre-release for 1.1.0 which I hope to release before
linux-2.6.0-final.  Bug reports are very welcome.


1/ A buffer-overflow bug was found by 
    Janusz Niewiadomski
    iSEC Security Research
    http://isec.pl/

  It is trivially exploitable to effect a remote denial of service.  More subtle
  exploits may be possible.

  I recommend that all users of nfs-utils either:
    1/ upgrade to 1.0.4 
  or
    2/ Get an update from their vendor (most vendors should have an update 
       available).

  I also recommend that all NFS services be protected from the internet-at-large by 
  a firewall where that is possible.

2/ See the change log in the source for details on bug fixes.

3/ In 2.4 and earlier kernels, the nfs server needed to know about any client
 that expected to be able to access files via NFS.  This information would be given
 to the kernel by "mountd" when the client mounted the filesystem, or by
 "exportfs" at system startup.  exportfs would take information about active clients
 from /var/lib/nfs/rmtab.
 This approach is quite fragile as it depends on rmtab being correct which
 is not always easy, particularly when trying to implement fail-over.  Even when
 the system is working well, rmtab suffers from getting lots of old entries that 
 never get removed.

 With 2.6 we have the option of having the kernel tell mountd when it gets a request
 from an unknown host, and mountd can give appropriate export information to
 the kernel.  This removes the dependancy on rmtab and means that the kernel only
 needs to know about currently active clients.

 To enable this new functionality, you need to:
   mount -t nfsd nfsd /proc/fs/nfs

 before running exportfs or mountd.  

 If you are using 2.6.0-testX and exporting files with NFS *please* test this out
 and let me know of any problems.

NeilBrown - July 2003