Latest working kernel version: 2.6.16.59
Earliest failing kernel version: 2.6.16.59
Distribution: gentoo, vanile kernel

Hardware Environment:
00:00.0 Host bridge: nVidia Corporation nForce2 AGP (different version?) (rev c1)
00:00.1 RAM memory: nVidia Corporation nForce2 Memory Controller 1 (rev c1)
00:00.2 RAM memory: nVidia Corporation nForce2 Memory Controller 4 (rev c1)
00:00.3 RAM memory: nVidia Corporation nForce2 Memory Controller 3 (rev c1)
00:00.4 RAM memory: nVidia Corporation nForce2 Memory Controller 2 (rev c1)
00:00.5 RAM memory: nVidia Corporation nForce2 Memory Controller 5 (rev c1)
00:01.0 ISA bridge: nVidia Corporation nForce2 ISA Bridge (rev a4)
00:01.1 SMBus: nVidia Corporation nForce2 SMBus (MCP) (rev a2)
00:02.0 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)
00:02.1 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)
00:02.2 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)
00:08.0 PCI bridge: nVidia Corporation nForce2 External PCI Bridge (rev a3)
00:09.0 IDE interface: nVidia Corporation nForce2 IDE (rev a2)
00:1e.0 PCI bridge: nVidia Corporation nForce2 AGP (rev c1)
01:07.0 Multimedia audio controller: Cirrus Logic Crystal CS4281 PCI Audio (rev 01)
01:08.0 Multimedia audio controller: Creative Labs SB Audigy LS
01:09.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
01:0a.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
02:00.0 VGA compatible controller: nVidia Corporation NV34 [GeForce FX 5200] (rev a1)

Software Environment:
Problem Description:
This bug show in syslog on main machine. I do nothing on there at that time. I only connect notebook to switch, where was connected main machine. After that in syslog show this messages:

May  8 13:23:57 sky kernel: ------------[ cut here ]------------
May  8 13:23:57 sky kernel: kernel BUG at mm/mmap.c:1980!
May  8 13:23:57 sky kernel: invalid opcode: 0000 [#1]
May  8 13:23:57 sky kernel: PREEMPT 
May  8 13:23:57 sky kernel: Modules linked in: ppp_deflate zlib_deflate zlib_inflate bsd_comp nfsd exportfs lockd sunrpc snd_seq_midi snd_pcm_oss snd_mixer_oss snd_seq_oss snd_seq_midi_event snd_seq snd_cs4281 snd_opl3_lib snd_hwdep xt_state iptable_nat snd_ca0106 snd_rawmidi snd_seq_device snd_ac97_codec snd_pcm snd_timer snd snd_ac97_bus snd_page_alloc ip_nat ip_conntrack it87 hwmon_vid hwmon i2c_isa rfcomm l2cap ppp_async ppp_generic slhc crc_ccitt lp tun kqemu fuse pktcdvd hci_usb bluetooth parport_pc parport i2c_nforce2 nvidia i2c_core nvidiafb ohci_hcd 8139too
May  8 13:23:57 sky kernel: CPU:    0
May  8 13:23:57 sky kernel: EIP:    0060:[exit_mmap+260/288]    Tainted: P      VLI
May  8 13:23:57 sky kernel: EIP:    0060:[<c0152ce4>]    Tainted: P      VLI
May  8 13:23:57 sky kernel: EFLAGS: 00210282   (2.6.16.59 #1) 
May  8 13:23:57 sky kernel: EIP is at exit_mmap+0x104/0x120
May  8 13:23:57 sky kernel: eax: 00000000   ebx: fffffffe   ecx: 00000001   edx: 00000000
May  8 13:23:57 sky kernel: esi: 00000000   edi: dfa3e8a0   ebp: 00000001   esp: ce727e50
May  8 13:23:57 sky kernel: ds: 007b   es: 007b   ss: 0068
May  8 13:23:57 sky kernel: Process enconv (pid: 23306, threadinfo=ce726000 task=cb569a70)
May  8 13:23:57 sky kernel: Stack: <0>c950bd2c c950b2dc 00000000 00000000 ce727e6c 00000000 c043013c 00000018 
May  8 13:23:57 sky kernel:        dfa3e8a0 dfa3e8e0 0000000b c0118c27 dfa3e8a0 ce726000 cb569a70 c011e343 
May  8 13:23:57 sky kernel:        dfa3e8a0 ce727f24 ce727fbc cb569ed4 cd2e1760 ce726000 0000000b ce727f24 
May  8 13:23:57 sky kernel: Call Trace:
May  8 13:23:57 sky kernel:  [mmput+55/176] mmput+0x37/0xb0
May  8 13:23:57 sky kernel:  [<c0118c27>] mmput+0x37/0xb0
May  8 13:23:57 sky kernel:  [do_exit+195/1152] do_exit+0xc3/0x480
May  8 13:23:57 sky kernel:  [<c011e343>] do_exit+0xc3/0x480
May  8 13:23:57 sky kernel:  [do_group_exit+60/208] do_group_exit+0x3c/0xd0
May  8 13:23:57 sky kernel:  [<c011e77c>] do_group_exit+0x3c/0xd0
May  8 13:23:57 sky kernel:  [get_signal_to_deliver+510/752] get_signal_to_deliver+0x1fe/0x2f0
May  8 13:23:57 sky kernel:  [<c0128c1e>] get_signal_to_deliver+0x1fe/0x2f0
May  8 13:23:57 sky kernel:  [do_signal+115/368] do_signal+0x73/0x170
May  8 13:23:57 sky kernel:  [<c01030c3>] do_signal+0x73/0x170
May  8 13:23:57 sky kernel:  [wake_up_state+26/32] wake_up_state+0x1a/0x20
May  8 13:23:57 sky kernel:  [<c0116aea>] wake_up_state+0x1a/0x20
May  8 13:23:57 sky kernel:  [force_sig_info+118/176] force_sig_info+0x76/0xb0
May  8 13:23:57 sky kernel:  [<c01271b6>] force_sig_info+0x76/0xb0
May  8 13:23:57 sky kernel:  [force_sig+31/48] force_sig+0x1f/0x30
May  8 13:23:57 sky kernel:  [<c0127c7f>] force_sig+0x1f/0x30
May  8 13:23:57 sky kernel:  [do_general_protection+174/560] do_general_protection+0xae/0x230
May  8 13:23:57 sky kernel:  [<c010467e>] do_general_protection+0xae/0x230
May  8 13:23:57 sky kernel:  [do_general_protection+0/560] do_general_protection+0x0/0x230
May  8 13:23:57 sky kernel:  [<c01045d0>] do_general_protection+0x0/0x230
May  8 13:23:57 sky kernel:  [do_notify_resume+55/60] do_notify_resume+0x37/0x3c
May  8 13:23:57 sky kernel:  [<c01031f7>] do_notify_resume+0x37/0x3c
May  8 13:23:57 sky kernel:  [work_notifysig+19/25] work_notifysig+0x13/0x19
May  8 13:23:57 sky kernel:  [<c01033be>] work_notifysig+0x13/0x19
May  8 13:23:57 sky kernel: Code: 8d b4 26 00 00 00 00 89 34 24 e8 58 dc ff ff 89 c6 85 f6 75 f2 8b 5f 74 85 db 75 0f 83 c4 20 5b 5e 5f c3 0f 20 d8 0f 22 d8 eb bb <0f> 0b bc 07 17 30 37 c0 eb e7 e8 0d 4f 20 00 eb d5 8d 74 26 00 
May  8 13:23:57 sky kernel:  <1>Fixing recursive fault but reboot is needed!


Steps to reproduce:
This message show once. I can not reproduce it.