Comment 4 for bug 606892

I upgraded the kernel to the latest version:

uname -a
Linux byron 2.6.32-24-server #41-Ubuntu SMP Thu Aug 19 02:47:08 UTC 2010 x86_64 GNU/Linux

and within a few hours the issue has reappeared. I attach a log of the console output. Again the kernel locked up, unable even to respond to Magic SysRq.

I notice that the same as last time, the process munin-node is implicated. I will disable munin-node for now, but clearly a user-mode process should not be able to lock up the kernel.

[20265.245221] ------------[ cut here ]------------
[20265.260159] kernel BUG at /build/buildd/linux-2.6.32/kernel/cred.c:168!
[20265.276697] invalid opcode: 0000 [#1] SMP
[20265.290483] last sysfs file: /sys/devices/system/cpu/cpu15/cache/index2/shared_cpu_map
[20265.317858] CPU 9
[20265.330789] Modules linked in: ip6table_filter ip6_tables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables nfsd kvm_intel lockd nfs_acl kvm auth_rpcgss sunrpc exportfs 8021q garp fbcon tileblit bridge font bitblit stp softcursor vga16fb vgastate ipmi_si psmouse ipmi_devintf serio_raw ioatdma ipmi_msghandler joydev usbhid hid igb 3w_9xxx dca
[20265.372725] Pid: 30950, comm: munin-node Not tainted 2.6.32-24-server #41-Ubuntu X8DTU
[20265.372727] RIP: 0010:[<ffffffff8108b48e>] [<ffffffff8108b48e>] __put_cred+0x3e/0x50
[20265.372736] RSP: 0018:ffff8809a3537ed8 EFLAGS: 00010202
[20265.372738] RAX: 0000000000000001 RBX: ffff880622f68fc0 RCX: 00000000ffffffff
[20265.372740] RDX: 00000000ffffffff RSI: ffff880622f68fc0 RDI: ffff880622f68fc0
[20265.372742] RBP: ffff8809a3537ed8 R08: 0000000000000000 R09: ffff880c225d78e0
[20265.372745] R10: 00000000000000c0 R11: 0000000000000000 R12: ffff880622f683c0
[20265.372747] R13: ffff880c21d496f0 R14: 0000000000000001 R15: 0000000000000001
[20265.372750] FS: 00007f5012e9a700(0000) GS:ffff880016ea0000(0000) knlGS:0000000000000000
[20265.372752] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[20265.372755] CR2: 00007f5011f99240 CR3: 00000009a3b31000 CR4: 00000000000026e0
[20265.372757] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000