I've reproduced this by running the OHAI command from the OpsCode Chef ohai gem (0.6.12) in a loop, although it took nearly 2 days before it triggered. Basically I ran `gem install ohai; while true; do ohai; done` in a screen session. The stack trace is: [18362917.357055] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [18362917.357079] IP: [] rb_next+0x1/0x50 [18362917.357098] PGD 1d098d067 PUD 1d045b067 PMD 0 [18362917.357110] Oops: 0000 [#1] SMP [18362917.357122] CPU 0 [18362917.357126] Modules linked in: ipt_REJECT xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack iptable_filter ip_tables x_tables isofs acpiphp [18362917.357152] [18362917.357157] Pid: 21217, comm: ohai Not tainted 3.2.0-23-virtual #36-Ubuntu [18362917.357166] RIP: e030:[] [] rb_next+0x1/0x50 [18362917.357176] RSP: e02b:ffff8801d22f1808 EFLAGS: 00010046 [18362917.357181] RAX: 0000000000000000 RBX: ffff8801d0842600 RCX: 0000000000000000 [18362917.357187] RDX: fffffffffffffff0 RSI: 0000000000000000 RDI: 0000000000000010 [18362917.357193] RBP: ffff8801d22f1838 R08: 0000000000000000 R09: 0000000000000000 [18362917.357199] R10: ffff8801dffa26c0 R11: 0000000000000001 R12: 0000000000000000 [18362917.357207] R13: 0000000000000000 R14: 0000000000000008 R15: ffff8801d0dc2d00 [18362917.357218] FS: 00007fcdb3810700(0000) GS:ffff8801dff73000(0000) knlGS:0000000000000000 [18362917.357225] CS: e033 DS: 0000 ES: 0000 CR0: 000000008005003b [18362917.357232] CR2: 0000000000000010 CR3: 00000001d2641000 CR4: 0000000000002660 [18362917.357240] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [18362917.357246] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [18362917.357253] Process ohai (pid: 21217, threadinfo ffff8801d22f0000, task ffff8801d0ad44a0) [18362917.357261] Stack: [18362917.357265] ffff8801d22f1838 ffffffff8104ece9 ffff8801d0842600 ffff8801dff866c0 [18362917.357277] ffff8801d0842e00 0000000000000008 ffff8801d22f1868 ffffffff810544b8 [18362917.357289] ffff8801d22f1868 ffff8801dff866c0 0000000000000000 ffff8801d0ad4848 [18362917.357301] Call Trace: [18362917.357314] [] ? pick_next_entity+0xb9/0xe0 [18362917.357322] [] pick_next_task_fair+0x38/0x70 [18362917.357331] [] __schedule+0x14c/0x6f0 [18362917.357341] [] ? xen_force_evtchn_callback+0xd/0x10 [18362917.357348] [] schedule+0x3f/0x60 [18362917.357355] [] schedule_hrtimeout_range_clock+0x14d/0x170 [18362917.357365] [] ? xen_restore_fl_direct_reloc+0x4/0x4 [18362917.357373] [] ? _raw_spin_unlock_irqrestore+0x1e/0x30 [18362917.357383] [] ? add_wait_queue+0x4d/0x60 [18362917.357389] [] schedule_hrtimeout_range+0x13/0x20 [18362917.357400] [] poll_schedule_timeout+0x49/0x70 [18362917.357408] [] do_select+0x4d6/0x600 [18362917.357414] [] ? poll_freewait+0xe0/0xe0 [18362917.357422] [] ? __pollwait+0xf0/0xf0 [18362917.357431] [] ? cpumask_next_and+0x36/0x50 [18362917.357438] [] ? select_idle_sibling+0x174/0x220 [18362917.357445] [] ? radix_tree_lookup+0xb/0x10 [18362917.357453] [] ? irq_to_desc+0x17/0x20 [18362917.357461] [] ? irq_get_irq_data+0xe/0x10 [18362917.357472] [] ? info_for_irq+0xe/0x30 [18362917.357478] [] ? cpumask_next_and+0x36/0x50 [18362917.357487] [] ? find_busiest_group+0x171/0xbb0 [18362917.357494] [] core_sys_select+0x1c1/0x330 [18362917.357501] [] ? _raw_spin_unlock_irqrestore+0x1e/0x30 [18362917.357511] [] ? idle_balance+0xf0/0x11b [18362917.357517] [] ? xen_force_evtchn_callback+0xd/0x10 [18362917.357524] [] ? check_events+0x12/0x20 [18362917.357531] [] ? xen_restore_fl_direct_reloc+0x4/0x4 [18362917.357538] [] ? xen_mc_flush+0xb2/0x1c0 [18362917.357545] [] ? xen_restore_fl_direct_reloc+0x4/0x4 [18362917.357552] [] sys_select+0xbb/0x100 [18362917.357559] [] ? schedule_tail+0x27/0xb0 [18362917.357568] [] system_call_fastpath+0x16/0x1b [18362917.357573] Code: 89 06 48 8b 47 08 48 89 46 08 48 8b 47 10 48 89 46 10 c3 0f 1f 80 00 00 00 00 48 89 32 eb b2 0f 1f 00 48 89 70 10 eb a9 66 90 55 <48> 8b 17 48 89 e5 48 89 d0 48 83 e0 fc 48 39 c7 74 34 48 8b 47 [18362917.357653] RIP [] rb_next+0x1/0x50 [18362917.357660] RSP [18362917.357664] CR2: 0000000000000010 [18362917.357673] ---[ end trace de16620c8d9e9c7c ]---