Bug 218723

Description of problem:
I have been trying to get the dibbler DHCPv6 server/client working on my
network. I get the following oops immediately every 
time I quit the dibbler dhcpv6 client:

Dec  5 22:03:17 mbooth kernel: BUG: unable to handle kernel NULL pointer
dereference at virtual address 00000003
Dec  5 22:03:17 mbooth kernel:  printing eip:
Dec  5 22:03:17 mbooth kernel: f8defe18
Dec  5 22:03:17 mbooth kernel: *pde = 00000000
Dec  5 22:03:17 mbooth kernel: Oops: 0000 [#1]
Dec  5 22:03:17 mbooth kernel: SMP 
Dec  5 22:03:17 mbooth kernel: last sysfs file:
/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/cmd
Dec  5 22:03:17 mbooth kernel: Modules linked in: rfcomm hidp l2cap ohci1394
ieee1394 button xt_state ip_conntrack nfnetlink 
ip6table_filter ip6_tables x_tables i915 drm arc4 ieee80211_crypt_wep autofs4
rpcsec_gss_krb5 auth_rpcgss des sunrpc ipv6 cpu
freq_ondemand dm_multipath video sbs ibm_acpi i2c_ec dock battery asus_acpi ac
parport_pc lp parport snd_hda_intel snd_hda_co
dec snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq sg snd_seq_device
snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd so
undcore ipw3945(U) snd_page_alloc i2c_i801 sdhci pcspkr serio_raw ieee80211
mmc_core hci_usb i2c_core ieee80211_crypt e1000 b
luetooth dm_snapshot dm_zero dm_mirror dm_mod ahci libata sd_mod scsi_mod ext3
jbd ehci_hcd ohci_hcd uhci_hcd
Dec  5 22:03:17 mbooth kernel: CPU:    0
Dec  5 22:03:17 mbooth kernel: EIP:    0060:[<f8defe18>]    Not tainted VLI
Dec  5 22:03:17 mbooth kernel: EFLAGS: 00010246   (2.6.18-1.2849.fc6 #1) 
Dec  5 22:03:17 mbooth kernel: EIP is at inet6_addr_del+0x67/0x95 [ipv6]
Dec  5 22:03:17 mbooth kernel: eax: 0000000b   ebx: 000000c0   ecx: f7fff180  
edx: 00000000
Dec  5 22:03:17 mbooth avahi-daemon[2455]: Withdrawing address record for
2001:4bd0:2057:1:ffff:7a92:9714:9b5c on eth1.
Dec  5 22:03:17 mbooth kernel: esi: ffffffff   edi: d83f1a1c   ebp: 000000c0  
esp: f50b3ca4
Dec  5 22:03:17 mbooth kernel: ds: 007b   es: 007b   ss: 0068
Dec  5 22:03:17 mbooth kernel: Process dibbler-client (pid: 28100, ti=f50b3000
task=f73809e0 task.ti=f50b3000)
Dec  5 22:03:17 mbooth kernel: Stack: 00000001 d83f1a00 f8defe46 00000028
c05c0689 00000000 00000000 00000005 
Dec  5 22:03:17 mbooth kernel:        00000044 f50b3cf8 e33bd6c0 f8e23748
e33bd6c0 d83f1a00 f50b3d10 00000040 
Dec  5 22:03:17 mbooth kernel:        c05cc961 c05c04ca c18f3c00 c18f3c84
00000040 c06a78a0 c18f3c00 00000040 
Dec  5 22:03:17 mbooth kernel: Call Trace:
Dec  5 22:03:17 mbooth kernel:  [<c05c0689>] rtnetlink_rcv_msg+0x1bf/0x1e4
Dec  5 22:03:17 mbooth kernel:  [<c05cc961>] netlink_run_queue+0x6b/0x102
Dec  5 22:03:17 mbooth kernel:  [<c05c0486>] rtnetlink_rcv+0x25/0x3d
Dec  5 22:03:17 mbooth kernel:  [<c05cce13>] netlink_data_ready+0x12/0x52
Dec  5 22:03:17 mbooth kernel:  [<c05cbe5c>] netlink_sendskb+0x1c/0x33
Dec  5 22:03:17 mbooth kernel:  [<c05ccdf5>] netlink_sendmsg+0x282/0x28e
Dec  5 22:03:17 mbooth kernel:  [<c05af6a6>] sock_sendmsg+0xd0/0xeb
Dec  5 22:03:17 mbooth kernel:  [<c05afec9>] sys_sendmsg+0x192/0x1f7
Dec  5 22:03:17 mbooth kernel:  [<c05b1427>] sys_socketcall+0x240/0x261
Dec  5 22:03:17 mbooth kernel:  [<c0404013>] syscall_call+0x7/0xb
Dec  5 22:03:17 mbooth kernel: DWARF2 unwinder stuck at syscall_call+0x7/0xb
Dec  5 22:03:17 mbooth kernel: Leftover inexact backtrace:
Dec  5 22:03:17 mbooth kernel:  =======================
Dec  5 22:03:17 mbooth kernel: Code: 04 39 47 04 75 38 8b 43 08 39 47 08 75 30
8b 43 0c 39 47 0c 75 28 f0 ff 43 24 8d 46 60 e
8 a0 46 82 c7 89 d8 e8 f9 fb ff ff 31 d2 <83> 7e 04 00 75 21 8b 06 b2 01 e8 1b
f3 ff ff 31 d2 eb 14 8b 5b 
Dec  5 22:03:17 mbooth kernel: EIP: [<f8defe18>] inet6_addr_del+0x67/0x95 [ipv6]
SS:ESP 0068:f50b3ca4

Version-Release number of selected component (if applicable):
kernel-2.6.18-1.2849.fc6

How reproducible:
Always

Steps to Reproduce:
1. On a machine on the network, run 'dibbler-server run'(I'm running it on RHEL4)
2. On the client, run 'dibbler-client run'
3. Wait for the client to get an address
4. Ctrl-C the client
  
Additional info:
Everything is 32 bit. NIC in laptop is ipw3945.