Kernel Panic when accessing NFS share and locking files

[Michael Lang <Michael.Lang@jackal-net.at>]

Hi,

we encountered a serious problem, when using Solaris NFS (Server) 
accessing it with a CentOS5.1/RHEL5.1 client.
There are more occurrences of the problem, one i felt over when tried to 
recreate a different one was, that a unprivileged
User is able to Kernel Panic a machine with a few lines of code. I 
tested it with the result that 3 threads requesting a lock
on the same file already cause the kernel panic. Since this is my first 
kernel bug request, and it's at least for my understandig
a security problem, i will provide the code for recreation to a closed 
group only. Please point me to the right group ...

Call Trace:
  [<ffffffff80012323>] __fput+0x94/0x198
  [<ffffffff8002e2d2>] sys_fcntl+0x2d0/0x2dc
  [<ffffffff8005b28d>] tracesys+0xd5/0xe0
 Code: 0f 0b 68 8a de 28 80 c2 c7 07 48 89 c3 48 8b 03 48 85 c0 75
 RIP  [<ffffffff80027073>] locks_remove_flock+0xe4/0x122
 RSP <ffff81000be87e48>


regards
Michael Lang