Here's another one if it helps:
[848423.023156] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [848423.023180] IP: [<ffffffff8130d7f1>] rb_next+0x1/0x50 [848423.023194] PGD 18ad83067 PUD 18ad82067 PMD 0 [848423.023203] Oops: 0000 [#1] SMP [848423.023210] CPU 1 [848423.023213] Modules linked in: ipt_REJECT xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack iptable_filter ip_tables x_tables parport_pc ppdev lp parport isofs acpiphp [848423.023245] [848423.023249] Pid: 18572, comm: chef-client Not tainted 3.2.0-24-virtual #37-Ubuntu [848423.023258] RIP: e030:[<ffffffff8130d7f1>] [<ffffffff8130d7f1>] rb_next+0x1/0x50 [848423.023267] RSP: e02b:ffff88018af21c18 EFLAGS: 00010046 [848423.023273] RAX: 0000000000000000 RBX: ffff8801a125ce00 RCX: 0000000000000000 [848423.023278] RDX: fffffffffffffff0 RSI: 0000000000000000 RDI: 0000000000000010 [848423.023285] RBP: ffff88018af21c48 R08: 0000000000000000 R09: 0000000000000000 [848423.023291] R10: ffff8801dff866c0 R11: 0000000000000001 R12: 0000000000000000 [848423.023299] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000003a5a9d0 [848423.023311] FS: 00007fb6bdc16700(0000) GS:ffff8801dff8f000(0000) knlGS:0000000000000000 [848423.023319] CS: e033 DS: 0000 ES: 0000 CR0: 000000008005003b [848423.023325] CR2: 0000000000000010 CR3: 00000001a12e8000 CR4: 0000000000002660 [848423.023332] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [848423.023339] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [848423.023346] Process chef-client (pid: 18572, threadinfo ffff88018af20000, task ffff8801a12f8000) [848423.023353] Stack: [848423.023356] ffff88018af21c48 ffffffff8104ece9 ffff8801a125ce00 ffff8801dffa26c0 [848423.023369] ffff8801d29cc600 0000000000000000 ffff88018af21c78 ffffffff810544b8 [848423.023380] ffff88018af21c78 ffff8801dffa26c0 0000000000000001 ffff8801a12f83a8 [848423.023392] Call Trace: [848423.023402] [<ffffffff8104ece9>] ? pick_next_entity+0xb9/0xe0 [848423.023410] [<ffffffff810544b8>] pick_next_task_fair+0x38/0x70 [848423.023419] [<ffffffff81652ddc>] __schedule+0x14c/0x6f0 [848423.023426] [<ffffffff816554ee>] ? _raw_spin_unlock_irqrestore+0x1e/0x30 [848423.023433] [<ffffffff8165344f>] schedule+0x3f/0x60 [848423.023441] [<ffffffff8117e119>] pipe_wait+0x59/0x80 [848423.023449] [<ffffffff81089340>] ? add_wait_queue+0x60/0x60 [848423.023456] [<ffffffff8117e87a>] pipe_read+0x1da/0x330 [848423.023463] [<ffffffff81174522>] do_sync_read+0xd2/0x110 [848423.023471] [<ffffffff8100a25d>] ? xen_force_evtchn_callback+0xd/0x10 [848423.023478] [<ffffffff8100aa32>] ? check_events+0x12/0x20 [848423.023486] [<ffffffff81298d33>] ? security_file_permission+0x93/0xb0 [848423.023493] [<ffffffff811749a1>] ? rw_verify_area+0x61/0xf0 [848423.023499] [<ffffffff81174e80>] vfs_read+0xb0/0x180 [848423.023505] [<ffffffff81174f9a>] sys_read+0x4a/0x90 [848423.023513] [<ffffffff8165d8c2>] system_call_fastpath+0x16/0x1b [848423.023518] 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 [848423.023608] RIP [<ffffffff8130d7f1>] rb_next+0x1/0x50 [848423.023615] RSP <ffff88018af21c18> [848423.023619] CR2: 0000000000000010 [848423.023637] ---[ end trace 5361bc1ec5930886 ]---
Here's another one if it helps:
[848423.023156] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 7f1>] rb_next+0x1/0x50 ffffffff8130d7f 1>] [<ffffffff8130d 7f1>] rb_next+0x1/0x50 f21c18 EFLAGS: 00010046 0(0000) GS:ffff8801dff8 f000(0000) knlGS:000000000 0000000 ce9>] ? pick_next_ entity+ 0xb9/0xe0 4b8>] pick_next_ task_fair+ 0x38/0x70 ddc>] __schedule+ 0x14c/0x6f0 4ee>] ? _raw_spin_ unlock_ irqrestore+ 0x1e/0x30 44f>] schedule+0x3f/0x60 119>] pipe_wait+0x59/0x80 340>] ? add_wait_ queue+0x60/ 0x60 87a>] pipe_read+ 0x1da/0x330 522>] do_sync_ read+0xd2/ 0x110 25d>] ? xen_force_ evtchn_ callback+ 0xd/0x10 a32>] ? check_events+ 0x12/0x20 d33>] ? security_ file_permission +0x93/0xb0 9a1>] ? rw_verify_ area+0x61/ 0xf0 e80>] vfs_read+0xb0/0x180 f9a>] sys_read+0x4a/0x90 8c2>] system_ call_fastpath+ 0x16/0x1b 7f1>] rb_next+0x1/0x50
[848423.023180] IP: [<ffffffff8130d
[848423.023194] PGD 18ad83067 PUD 18ad82067 PMD 0
[848423.023203] Oops: 0000 [#1] SMP
[848423.023210] CPU 1
[848423.023213] Modules linked in: ipt_REJECT xt_tcpudp nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack iptable_filter ip_tables x_tables parport_pc ppdev lp parport isofs acpiphp
[848423.023245]
[848423.023249] Pid: 18572, comm: chef-client Not tainted 3.2.0-24-virtual #37-Ubuntu
[848423.023258] RIP: e030:[<
[848423.023267] RSP: e02b:ffff88018a
[848423.023273] RAX: 0000000000000000 RBX: ffff8801a125ce00 RCX: 0000000000000000
[848423.023278] RDX: fffffffffffffff0 RSI: 0000000000000000 RDI: 0000000000000010
[848423.023285] RBP: ffff88018af21c48 R08: 0000000000000000 R09: 0000000000000000
[848423.023291] R10: ffff8801dff866c0 R11: 0000000000000001 R12: 0000000000000000
[848423.023299] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000003a5a9d0
[848423.023311] FS: 00007fb6bdc1670
[848423.023319] CS: e033 DS: 0000 ES: 0000 CR0: 000000008005003b
[848423.023325] CR2: 0000000000000010 CR3: 00000001a12e8000 CR4: 0000000000002660
[848423.023332] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[848423.023339] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[848423.023346] Process chef-client (pid: 18572, threadinfo ffff88018af20000, task ffff8801a12f8000)
[848423.023353] Stack:
[848423.023356] ffff88018af21c48 ffffffff8104ece9 ffff8801a125ce00 ffff8801dffa26c0
[848423.023369] ffff8801d29cc600 0000000000000000 ffff88018af21c78 ffffffff810544b8
[848423.023380] ffff88018af21c78 ffff8801dffa26c0 0000000000000001 ffff8801a12f83a8
[848423.023392] Call Trace:
[848423.023402] [<ffffffff8104e
[848423.023410] [<ffffffff81054
[848423.023419] [<ffffffff81652
[848423.023426] [<ffffffff81655
[848423.023433] [<ffffffff81653
[848423.023441] [<ffffffff8117e
[848423.023449] [<ffffffff81089
[848423.023456] [<ffffffff8117e
[848423.023463] [<ffffffff81174
[848423.023471] [<ffffffff8100a
[848423.023478] [<ffffffff8100a
[848423.023486] [<ffffffff81298
[848423.023493] [<ffffffff81174
[848423.023499] [<ffffffff81174
[848423.023505] [<ffffffff81174
[848423.023513] [<ffffffff8165d
[848423.023518] 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
[848423.023608] RIP [<ffffffff8130d
[848423.023615] RSP <ffff88018af21c18>
[848423.023619] CR2: 0000000000000010
[848423.023637] ---[ end trace 5361bc1ec5930886 ]---