[Linux-cluster] BUG: "NULL pointer dereference" in dlm_recv

[Jens Beyer]

Hi,

I am currently testing an GFS testcluster (2 Nodes) based on cluster-2.00.00 and 
a Vanilla 2.6.21-rc7 Kernel (As far as I saw in changes there where no gfs/related 
patches from 2.6.21-rc7 to 2.6.21 ?). 

While testing access via NFS on both nodes I got the following bug on one Node 
while writing on the other one:

428481.314146] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
[428481.314152]  printing eip:
[428481.314154] 00000000
[428481.314155] *pde = 00000000
[428481.314158] Oops: 0000 [#1]
[428481.314164] SMP 
[428481.314167] Modules linked in: nfs nfsd exportfs lockd nfs_acl sunrpc lock_dlm gfs2 dlm configfs drbd cn floppy nvram autofs4 e1000 piix tg3 dm_mod md_mod ide_cd cdrom ide_core sg sd_mod qla2300 
[428481.314197] CPU:    1
[428481.314198] EIP:    0060:[<00000000>]    Not tainted VLI
[428481.314199] EFLAGS: 00010097   (2.6.21-rc7-QLw #1)
[428481.314208] EIP is at rest_init+0x3feff000/0x25
[428481.314211] eax: ef7601f4   ebx: ef7601f4   ecx: 00000000   edx: 00000003
[428481.314215] esi: 00001f68   edi: 00000000   ebp: edf9df14   esp: edf9def4
[428481.314219] ds: 007b   es: 007b   fs: 00d8  gs: 0000  ss: 0068
[428481.314223] Process dlm_recv/1 (pid: 14727, ti=edf9c000 task=ee3e3570 task.ti=edf9c000)
[428481.314226] Stack: c0117515 00000000 ef760288 00000001 00000003 ef760278 00000000 00000001 
[428481.314235]        edf9df38 c0117567 00000000 00000000 00000082 00000003 ef6cf830 ef760240 
[428481.314244]        ef6cf82c 00000246 c012af03 00000000 c38296e0 ee3e3690 0000006e ef760278 
[428481.314253] Call Trace:
[428481.314257]  [<c0117515>] __wake_up_common+0x35/0x55
[428481.314264]  [<c0117567>] __wake_up+0x32/0x43
[428481.314270]  [<c012af03>] run_workqueue+0xd0/0x146
[428481.314277]  [<f0b8e8b5>] process_recv_sockets+0x0/0x15 [dlm]
[428481.314293]  [<c012b0a4>] worker_thread+0x12b/0x156
[428481.314299]  [<c01174d4>] default_wake_function+0x0/0xc
[428481.314305]  [<c01174d4>] default_wake_function+0x0/0xc
[428481.314310]  [<c012af79>] worker_thread+0x0/0x156
[428481.314315]  [<c012e050>] kthread+0x8c/0xb1
[428481.314320]  [<c012dfc4>] kthread+0x0/0xb1
[428481.314325]  [<c0104a23>] kernel_thread_helper+0x7/0x14
[428481.314331]  =======================
[428481.314333] Code:  Bad EIP value.
[428481.314338] EIP: [<00000000>] rest_init+0x3feff000/0x25 SS:ESP 0068:edf9def4

Regards,
Jens