Found a stack trace in /var/log/messages/

May 12 04:46:22 ubuntu kernel: [43380.856587] Pid: 19245, comm: chmod Tainted: P           (2.6.32-31-generic #61-Ubuntu) HP Compaq 8000 Elite SFF PC
May 12 04:46:22 ubuntu kernel: [43380.856591] EIP: 0060:[<c02f4a2a>] EFLAGS: 00210246 CPU: 3
May 12 04:46:22 ubuntu kernel: [43380.856594] EIP is at wait_for_key_construction+0x2a/0x70
May 12 04:46:22 ubuntu kernel: [43380.856596] EAX: 00000000 EBX: 00000000 ECX: c02f4a70 EDX: 00000000
May 12 04:46:22 ubuntu kernel: [43380.856599] ESI: 00000002 EDI: f28b4300 EBP: f0e3bb18 ESP: f0e3bb0c
May 12 04:46:22 ubuntu kernel: [43380.856601]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
May 12 04:46:22 ubuntu kernel: [43380.856607]  f8b168c0 00000000 f13d9e00 f0e3bb40 c02f53ba 00000000 00000000 00000000
May 12 04:46:22 ubuntu kernel: [43380.856614] <0> 00000000 f8b0900c f2905480 f2905480 f13d9e00 f0e3bb6c f8b023fc f29054cf
May 12 04:46:22 ubuntu kernel: [43380.856621] <0> f8b09002 00004b2d f6bf2320 f6bf2320 f28b43a2 f28b4300 00000800 00004058
May 12 04:46:22 ubuntu kernel: [43380.856633]  [<c02f53ba>] ? request_key+0x5a/0x90
May 12 04:46:22 ubuntu kernel: [43380.856642]  [<f8b023fc>] ? cifs_get_spnego_key+0x17c/0x1d0 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856649]  [<f8b00e1d>] ? CIFS_SessSetup+0x66d/0xc10 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856654]  [<c012a768>] ? default_spin_lock_flags+0x8/0x10
May 12 04:46:22 ubuntu kernel: [43380.856659]  [<c03b3bee>] ? extract_buf+0x7e/0xe0
May 12 04:46:22 ubuntu kernel: [43380.856665]  [<f8ae8a79>] ? cifs_setup_session+0x69/0x1a0 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856670]  [<c058f74f>] ? _spin_lock_irqsave+0x2f/0x50
May 12 04:46:22 ubuntu kernel: [43380.856676]  [<f8adf5eb>] ? cifs_reconnect_tcon+0x1ab/0x280 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856682]  [<f8adf6e4>] ? smb_init+0x24/0x80 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856688]  [<f8ae3375>] ? CIFSSMBUnixQPathInfo+0x55/0x250 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856696]  [<f8af4a5e>] ? cifs_get_inode_info_unix+0x5e/0x100 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856703]  [<f8aed8c5>] ? build_path_from_dentry+0xa5/0x1e0 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856710]  [<f8aed99c>] ? build_path_from_dentry+0x17c/0x1e0 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856714]  [<c058f84d>] ? _spin_lock+0xd/0x10
May 12 04:46:22 ubuntu kernel: [43380.856721]  [<f8af4cf4>] ? cifs_revalidate+0x1f4/0x3e0 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856725]  [<c021c811>] ? dput+0x91/0x130
May 12 04:46:22 ubuntu kernel: [43380.856728]  [<c0130925>] ? kmap_atomic_prot+0xd5/0xf0
May 12 04:46:22 ubuntu kernel: [43380.856735]  [<f8aedf1f>] ? cifs_d_revalidate+0x1f/0xe0 [cifs]
May 12 04:46:22 ubuntu kernel: [43380.856739]  [<c02142d1>] ? do_lookup+0x41/0xc0
May 12 04:46:22 ubuntu kernel: [43380.856743]  [<c021268f>] ? generic_permission+0x1f/0xa0
May 12 04:46:22 ubuntu kernel: [43380.856747]  [<c021476d>] ? __link_path_walk+0x15d/0xca0
May 12 04:46:22 ubuntu kernel: [43380.856750]  [<c01307b0>] ? kunmap_atomic+0x60/0x70
May 12 04:46:22 ubuntu kernel: [43380.856753]  [<c02154c4>] ? path_walk+0x54/0xc0
May 12 04:46:22 ubuntu kernel: [43380.856756]  [<c0215649>] ? do_path_lookup+0x59/0x90
May 12 04:46:22 ubuntu kernel: [43380.856760]  [<c0216191>] ? user_path_at+0x41/0x80
May 12 04:46:22 ubuntu kernel: [43380.856763]  [<c0130925>] ? kmap_atomic_prot+0xd5/0xf0
May 12 04:46:22 ubuntu kernel: [43380.856767]  [<c01e68e8>] ? __do_fault+0x3a8/0x490
May 12 04:46:22 ubuntu kernel: [43380.856771]  [<c020df3a>] ? vfs_fstatat+0x3a/0x70
May 12 04:46:22 ubuntu kernel: [43380.856774]  [<c020e090>] ? vfs_stat+0x20/0x30
May 12 04:46:22 ubuntu kernel: [43380.856777]  [<c020e0b9>] ? sys_stat64+0x19/0x30
May 12 04:46:22 ubuntu kernel: [43380.856781]  [<c0591c80>] ? do_page_fault+0x160/0x3a0
May 12 04:46:22 ubuntu kernel: [43380.856785]  [<c058fe70>] ? do_device_not_available+0x0/0x60
May 12 04:46:22 ubuntu kernel: [43380.856789]  [<c01033ec>] ? syscall_call+0x7/0xb
May 12 04:46:22 ubuntu kernel: [43380.856792]  [<c0590000>] ? do_debug+0x130/0x160
May 12 04:46:22 ubuntu kernel: [43380.856843] ---[ end trace 56c7be23cacaff6e ]---