======================================
| fbnic-err: bad register access fbnic_mac_read_sig address 0x11a01
| [  853.468465][   T70] fbnic 0000:01:00.0 enp1s0: Link is Down
| [  854.220017][   T94] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000046: 0000 [#1] SMP KASAN
| [  854.220374][   T94] KASAN: null-ptr-deref in range [0x0000000000000230-0x0000000000000237]
[  854.220841][   T94] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  854.221174][   T94] Workqueue: events fbnic_service_task
[  854.221332][   T94] RIP: 0010:fbnic_napi_depletion_check (drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:2808)
[  854.221525][   T94] Code: 00 48 89 d1 48 c1 e9 03 42 80 3c 21 00 0f 85 3c 06 00 00 48 8b 1a 48 8d bb 32 02 00 00 48 89 f9 48 89 fe 48 c1 e9 03 83 e6 07 <42> 0f b6 0c 21 40 38 f1 7f 08 84 c9 0f 85 e1 05 00 00 48 8d bb 33
All code
========
   0:	00 48 89             	add    %cl,-0x77(%rax)
   3:	d1 48 c1             	rorl   $1,-0x3f(%rax)
   6:	e9 03 42 80 3c       	jmp    0x3c80420e
   b:	21 00                	and    %eax,(%rax)
   d:	0f 85 3c 06 00 00    	jne    0x64f
  13:	48 8b 1a             	mov    (%rdx),%rbx
  16:	48 8d bb 32 02 00 00 	lea    0x232(%rbx),%rdi
  1d:	48 89 f9             	mov    %rdi,%rcx
  20:	48 89 fe             	mov    %rdi,%rsi
  23:	48 c1 e9 03          	shr    $0x3,%rcx
  27:	83 e6 07             	and    $0x7,%esi
  2a:*	42 0f b6 0c 21       	movzbl (%rcx,%r12,1),%ecx		<-- trapping instruction
  2f:	40 38 f1             	cmp    %sil,%cl
  32:	7f 08                	jg     0x3c
  34:	84 c9                	test   %cl,%cl
  36:	0f 85 e1 05 00 00    	jne    0x61d
  3c:	48                   	rex.W
  3d:	8d                   	.byte 0x8d
  3e:	bb                   	.byte 0xbb
  3f:	33                   	.byte 0x33

Code starting with the faulting instruction
===========================================
   0:	42 0f b6 0c 21       	movzbl (%rcx,%r12,1),%ecx
   5:	40 38 f1             	cmp    %sil,%cl
   8:	7f 08                	jg     0x12
   a:	84 c9                	test   %cl,%cl
   c:	0f 85 e1 05 00 00    	jne    0x5f3
  12:	48                   	rex.W
  13:	8d                   	.byte 0x8d
  14:	bb                   	.byte 0xbb
  15:	33                   	.byte 0x33
[  854.222065][   T94] RSP: 0018:ffffc9000066fad0 EFLAGS: 00010202
[  854.222248][   T94] RAX: ffffc9000066fb38 RBX: 0000000000000000 RCX: 0000000000000046
[  854.222464][   T94] RDX: ffff888008159908 RSI: 0000000000000002 RDI: 0000000000000232
[  854.222679][   T94] RBP: ffff8880081580a0 R08: 0000000000000000 R09: fffffbfff3b0edaa
[  854.222897][   T94] R10: 0000000000000003 R11: ffffffff9aeb7d30 R12: dffffc0000000000
[  854.223113][   T94] R13: ffff8880081580a0 R14: ffff888008318368 R15: ffff888008158000
[  854.223325][   T94] FS:  0000000000000000(0000) GS:ffff8880cec24000(0000) knlGS:0000000000000000
[  854.223575][   T94] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  854.223755][   T94] CR2: 00007fe072a01000 CR3: 000000001b131006 CR4: 0000000000772ef0
[  854.223974][   T94] PKRU: 55555554
[  854.224082][   T94] Call Trace:
[  854.224191][   T94]  <TASK>
[  854.224266][   T94]  ? fbnic_write_rules (drivers/net/ethernet/meta/fbnic/fbnic_rpc.c:1210 drivers/net/ethernet/meta/fbnic/fbnic_rpc.c:1238)
[  854.224419][   T94]  ? fbnic_napi_enable (drivers/net/ethernet/meta/fbnic/fbnic_txrx.c:2798)
[  854.224565][   T94]  fbnic_service_task (drivers/net/ethernet/meta/fbnic/fbnic_pci.c:235)
[  854.224714][   T94]  process_one_work (kernel/workqueue.c:3262)
[  854.224864][   T94]  ? pwq_dec_nr_in_flight (kernel/workqueue.c:3159)
[  854.225009][   T94]  ? assign_work (kernel/workqueue.c:1200)
[  854.225153][   T94]  worker_thread (kernel/workqueue.c:3334 kernel/workqueue.c:3421)
[  854.225297][   T94]  ? bh_worker (kernel/workqueue.c:3367)
[  854.225439][   T94]  kthread (kernel/kthread.c:463)
[  854.225552][   T94]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[  854.225695][   T94]  ? ret_from_fork (arch/x86/kernel/process.c:157)
[  854.225840][   T94]  ? __lock_release (kernel/locking/lockdep.c:5536)
[  854.225987][   T94]  ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5831)
[  854.226131][   T94]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[  854.226276][   T94]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[  854.226417][   T94]  ret_from_fork (arch/x86/kernel/process.c:164)
[  854.226560][   T94]  ? arch_exit_to_user_mode_prepare.constprop.0 (arch/x86/entry/syscall_64.c:37)
[  854.226773][   T94]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[  854.226918][   T94]  ? __switch_to (./arch/x86/include/asm/cpufeature.h:101 arch/x86/kernel/process_64.c:377 arch/x86/kernel/process_64.c:665)
[  854.227064][   T94]  ? kthread_is_per_cpu (kernel/kthread.c:412)


Finger prints:
fbnic_napi_depletion_check:fbnic_service_task:process_one_work:worker_thread:kthread