======================================
| xx__-> [   19.723131][  T305] netem: version 1.3
| [   21.101501][    C2] ------------[ cut here ]------------
| [   21.101936][    C2] WARNING: CPU: 2 PID: 27 at ./include/net/sch_generic.h:843 netem_dequeue (./include/net/sch_generic.h:843 ./include/net/sch_generic.h:889 ./include/net/sch_generic.h:901 net/sched/sch_netem.c:712) sch_netem
| [   21.102466][    C2] Modules linked in: sch_netem
[   21.103319][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   21.103678][    C2] RIP: 0010:netem_dequeue (./include/net/sch_generic.h:843 ./include/net/sch_generic.h:889 ./include/net/sch_generic.h:901 net/sched/sch_netem.c:712) sch_netem
[   21.104036][    C2] Code: 7d 06 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 89 09 00 00 66 83 7d 06 00 74 04 90 <0f> 0b 90 48 b8 00 00 00 00 00 fc ff df 4c 89 d2 48 c1 ea 03 0f b6
All code
========
   0:	7d 06                	jge    0x8
   2:	48 89 fa             	mov    %rdi,%rdx
   5:	48 c1 ea 03          	shr    $0x3,%rdx
   9:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx
   d:	48 89 f8             	mov    %rdi,%rax
  10:	83 e0 07             	and    $0x7,%eax
  13:	83 c0 01             	add    $0x1,%eax
  16:	38 d0                	cmp    %dl,%al
  18:	7c 08                	jl     0x22
  1a:	84 d2                	test   %dl,%dl
  1c:	0f 85 89 09 00 00    	jne    0x9ab
  22:	66 83 7d 06 00       	cmpw   $0x0,0x6(%rbp)
  27:	74 04                	je     0x2d
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  34:	fc ff df 
  37:	4c 89 d2             	mov    %r10,%rdx
  3a:	48 c1 ea 03          	shr    $0x3,%rdx
  3e:	0f                   	.byte 0xf
  3f:	b6                   	.byte 0xb6

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   a:	fc ff df 
   d:	4c 89 d2             	mov    %r10,%rdx
  10:	48 c1 ea 03          	shr    $0x3,%rdx
  14:	0f                   	.byte 0xf
  15:	b6                   	.byte 0xb6
[   21.104981][    C2] RSP: 0018:ffffc900001efb50 EFLAGS: 00010202
[   21.105334][    C2] RAX: 0000000000000007 RBX: ffff888004afa800 RCX: 0000000000000017
[   21.105856][    C2] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88800b96a106
[   21.106263][    C2] RBP: ffff88800b96a100 R08: 000000050e1a24df R09: 0000000000000001
[   21.106678][    C2] R10: ffff888009654148 R11: ffffffff9c3a2008 R12: 0000000000000001
[   21.107088][    C2] R13: dffffc0000000000 R14: ffff888009654120 R15: ffff888009654120
[   21.107512][    C2] FS:  0000000000000000(0000) GS:ffff88809aa83000(0000) knlGS:0000000000000000
[   21.107994][    C2] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   21.108339][    C2] CR2: 0000000008312008 CR3: 000000000bf32003 CR4: 0000000000772ef0
[   21.108753][    C2] PKRU: 55555554
[   21.108973][    C2] Call Trace:
[   21.109191][    C2]  <TASK>
[   21.109353][    C2]  ? get_slot_next (net/sched/sch_netem.c:703) sch_netem
[   21.109707][    C2]  ? skb_defer_free_flush (net/core/dev.c:6786)
[   21.109987][    C2]  ? __napi_poll.constprop.0 (net/core/dev.c:7673)
[   21.110273][    C2]  dequeue_skb (net/sched/sch_generic.c:297)
[   21.110561][    C2]  __qdisc_run (net/sched/sch_generic.c:403 net/sched/sch_generic.c:420)
[   21.110853][    C2]  ? sch_direct_xmit (net/sched/sch_generic.c:416)
[   21.111128][    C2]  ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:107 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116)
[   21.111409][    C2]  ? spin_bug (kernel/locking/spinlock_debug.c:114)
[   21.111626][    C2]  ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5831)
[   21.111909][    C2]  ? net_tx_action (./include/linux/spinlock.h:352 net/core/dev.c:5767)
[   21.112193][    C2]  net_tx_action (./include/net/sch_generic.h:223 ./include/net/pkt_sched.h:121 ./include/net/pkt_sched.h:117 net/core/dev.c:5783)
[   21.112475][    C2]  handle_softirqs (kernel/softirq.c:623)
[   21.112780][    C2]  ? run_ktimerd (kernel/softirq.c:1056)
[   21.113060][    C2]  run_ksoftirqd (kernel/softirq.c:479 kernel/softirq.c:1064 kernel/softirq.c:1055)
[   21.113338][    C2]  smpboot_thread_fn (kernel/smpboot.c:160 (discriminator 3))
[   21.113621][    C2]  ? sort_range (kernel/smpboot.c:103)
[   21.113848][    C2]  kthread (kernel/kthread.c:463)
[   21.114068][    C2]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[   21.114347][    C2]  ? ret_from_fork (arch/x86/kernel/process.c:157)
[   21.114626][    C2]  ? __lock_release (kernel/locking/lockdep.c:5536)
[   21.114918][    C2]  ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:751)
[   21.115201][    C2]  ? kthread_is_per_cpu (kernel/kthread.c:412)
[   21.115481][    C2]  ret_from_fork (arch/x86/kernel/process.c:164)
[   21.115769][    C2]  ? kthread_is_per_cpu (kernel/kthread.c:412)


Finger prints:
netem_dequeue:dequeue_skb:__qdisc_run:net_tx_action:handle_softirqs