BUG: unable to handle kernel NULL pointer dereference at 0000000000000304
IP: flush_unmaps_timeout+0xa7/0x1c0
PGD 3fec744067 
PUD 3fec672067 
PMD 0 

Oops: 0000 [#1] PREEMPT SMP
Modules linked in: nct7904 i2c_i801 coretemp hwmon
CPU: 4 PID: 3731 Comm: bacula-fd Not tainted 4.11.0-gentoo #1
Hardware name: Supermicro X10DAi/X10DAC, BIOS 2.0a 11/09/2016
task: ffff881fe9429c40 task.stack: ffffc9001ebd8000
RIP: 0010:flush_unmaps_timeout+0xa7/0x1c0
RSP: 0000:ffff881fffb03e48 EFLAGS: 00010006
RAX: ffff883ff1201f48 RBX: 0000000000000000 RCX: 0000000000000a70
RDX: 000000000000003f RSI: 0000000000000082 RDI: ffff881fff595780
RBP: ffff881fffb03e98 R08: 0000000000000010 R09: ffff881fff595780
R10: ffff881fe1f05400 R11: 0000000000000008 R12: 0000000000000000
R13: ffff883ff1201f48 R14: ffff881fff413800 R15: 00000000000b2e28
FS:  00007fc2d75fb700(0000) GS:ffff881fffb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000304 CR3: 0000003feaba3000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 ? iommu_flush_iotlb_psi+0x120/0x120
 call_timer_fn+0x35/0x180
 ? iommu_flush_iotlb_psi+0x120/0x120
 run_timer_softirq+0x1ef/0x450
 ? clockevents_program_event+0x82/0x120
 __do_softirq+0xc0/0x2d0
 irq_exit+0xb0/0xc0
 smp_apic_timer_interrupt+0x3d/0x50
 apic_timer_interrupt+0x86/0x90
RIP: 0033:0x7fc2d984691c
RSP: 002b:00007fc2d75fa3a0 EFLAGS: 00000a13 ORIG_RAX: ffffffffffffff10
RAX: 0000000056a75d93 RBX: 00000000e586bdbe RCX: 0000000052447dc3
RDX: 00000000228609c4 RSI: 00007fc2d0007750 RDI: 00007fc2d0014a50
RBP: 00007fc2d00034e0 R08: 000000003c10a1cb R09: 000000006911d202
R10: 0000000008689b90 R11: 00000000ffffffff R12: 00000000f9ce1e7e
R13: 0000000000010000 R14: 00000000d5ac9f3d R15: 000000006e32da1e
 </IRQ>
Code: 8b 45 00 85 c0 0f 84 d5 00 00 00 41 f6 46 18 80 0f 84 04 01 00 00 85 c0 0f 8e ba 00 00 00 31 db eb 3d ba ff ff ff ff 49 0f bd d2 <41> 80 bc 24 04 03 00 00 00 75 7e 49 8d bc 24 18 03 00 00 4c 89 
RIP: flush_unmaps_timeout+0xa7/0x1c0 RSP: ffff881fffb03e48
CR2: 0000000000000304
---[ end trace 1fc0a9589f99eebf ]---
Kernel panic - not syncing: Fatal exception in interrupt
Kernel Offset: disabled
---[ end Kernel panic - not syncing: Fatal exception in interrupt