kernel panics in nfs4_proc_lock() - CVE-2009-3726.

Issue

• System crashes with following panic message:

  Unable to handle kernel NULL pointer dereference at 0000000000000030 RIP:
   [<ffffffff8837b210>] :nfs:nfs4_proc_lock+0x21f/0x3ad
  PGD 1026eec067 PUD 1026f2f067 PMD 0
  Oops: 0000 [1] SMP
  last sysfs file: /block/dm-1/range
  CPU 0
  Modules linked in: ipmi_devintf ipmi_si ipmi_msghandler nfs lockd fscache
  nfs_acl sunrpc bonding ipv6 xfrm_nalgo crypto_api video hwmon backlight sbs
  i2c_ec button battery asus_acpi acpi_memhotplug ac joydev sg shpchp i2c_nforce2
  i2c_core forcedeth dm_snapshot dm_zero dm_mod sata_nv libata mptsas mptscsih
  mptbase scsi_transport_sas sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd
  Pid: 4070, comm: XMLMissingField Not tainted 2.6.18-164.2.1.el5 #1
  RIP: 0010:[<ffffffff8837b210>]  [<ffffffff8837b210>]
  :nfs:nfs4_proc_lock+0x21f/0x3ad