Note the issue is already in boot.log
<6>[    5.074822] snd_hda_codec_realtek hdaudioC0D0: autoconfig for ALC283: line_outs=2 (0x1b/0x21/0x0/0x0/0x0) type:hp
<6>[    5.074830] snd_hda_codec_realtek hdaudioC0D0:    speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
<6>[    5.074834] snd_hda_codec_realtek hdaudioC0D0:    hp_outs=0 (0x0/0x0/0x0/0x0/0x0)
<6>[    5.074838] snd_hda_codec_realtek hdaudioC0D0:    mono: mono_out=0x0
<6>[    5.074843] snd_hda_codec_realtek hdaudioC0D0:    dig-out=0x1e/0x0
<6>[    5.074847] snd_hda_codec_realtek hdaudioC0D0:    inputs:
<6>[    5.074851] snd_hda_codec_realtek hdaudioC0D0:      Mic=0x19
<6>[    5.074856] snd_hda_codec_realtek hdaudioC0D0:      Internal Mic=0x12
<1>[    5.150957] BUG: unable to handle kernel NULL pointer dereference at           (null)
<1>[    5.150971] IP: hda_widget_sysfs_reinit+0x13c/0x200 [snd_hda_core]
<6>[    5.150973] PGD 0 P4D 0 
<4>[    5.150977] Oops: 0000 [#1] PREEMPT SMP PTI
<4>[    5.150979] Modules linked in: snd_hda_codec_hdmi(+) snd_hda_codec_realtek snd_hda_codec_generic i915 x86_pkg_temp_thermal coretemp crct10dif_pclmul crc32_pclmul snd_hda_intel ghash_clmulni_intel snd_hda_codec snd_hwdep snd_hda_core r8169 lpc_ich mii snd_pcm mei_me mei prime_numbers pinctrl_broxton pinctrl_intel
<4>[    5.151001] CPU: 3 PID: 253 Comm: systemd-udevd Not tainted 4.15.0-rc9-CI-CI_DRM_3673+ #1
<4>[    5.151002] Hardware name:                  /NUC6CAYB, BIOS AYAPLCEL.86A.0040.2017.0619.1722 06/19/2017
<4>[    5.151008] RIP: 0010:hda_widget_sysfs_reinit+0x13c/0x200 [snd_hda_core]
<4>[    5.151009] RSP: 0018:ffffc900003e3b80 EFLAGS: 00010246
<4>[    5.151011] RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffff88025ff69b58
<4>[    5.151012] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff82246460
<4>[    5.151014] RBP: ffff880265b84548 R08: 0000000000000001 R09: ffff88026e3fa198
<4>[    5.151015] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
<4>[    5.151016] R13: 0000000000000038 R14: ffffffffa00a67c0 R15: ffff88026a193e38
<4>[    5.151017] FS:  00007fbaf82658c0(0000) GS:ffff88027fd80000(0000) knlGS:0000000000000000
<4>[    5.151018] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[    5.151020] CR2: 0000000000000000 CR3: 000000027326c000 CR4: 00000000003406e0
<4>[    5.151021] Call Trace:
<4>[    5.151030]  snd_hdac_refresh_widgets+0x65/0x90 [snd_hda_core]
<4>[    5.151040]  snd_hda_codec_update_widgets+0xe/0x50 [snd_hda_codec]
<4>[    5.151047]  intel_hsw_common_init.part.20+0x2b/0x90 [snd_hda_codec_hdmi]
<4>[    5.151053]  hda_codec_driver_probe+0x5e/0x100 [snd_hda_codec]
<4>[    5.151059]  driver_probe_device+0x2a3/0x480
<4>[    5.151063]  __driver_attach+0xd9/0xe0
<4>[    5.151066]  ? driver_probe_device+0x480/0x480
<4>[    5.151067]  bus_for_each_dev+0x57/0x90
<4>[    5.151070]  bus_add_driver+0x168/0x260
<4>[    5.151074]  driver_register+0x52/0xc0
<4>[    5.151075]  ? 0xffffffffa03a1000
<4>[    5.151078]  do_one_initcall+0x39/0x150
<4>[    5.151082]  ? rcu_read_lock_sched_held+0x6f/0x80
<4>[    5.151085]  ? kmem_cache_alloc_trace+0x248/0x2b0
<4>[    5.151088]  do_init_module+0x56/0x1ef
<4>[    5.151091]  load_module+0x231c/0x2d70
<4>[    5.151096]  ? show_coresize+0x20/0x20
<4>[    5.151098]  ? vfs_read+0x126/0x150
<4>[    5.151106]  ? SyS_finit_module+0xa5/0xe0
<4>[    5.151108]  SyS_finit_module+0xa5/0xe0
<4>[    5.151115]  do_syscall_64+0x59/0x1a0
<4>[    5.151119]  entry_SYSCALL64_slow_path+0x25/0x25
<4>[    5.151121] RIP: 0033:0x7fbaf70ee9f9
<4>[    5.151122] RSP: 002b:00007ffefb0c8e58 EFLAGS: 00000202 ORIG_RAX: 0000000000000139
<4>[    5.151124] RAX: ffffffffffffffda RBX: 00005591f5ae89f0 RCX: 00007fbaf70ee9f9
<4>[    5.151125] RDX: 0000000000000000 RSI: 00007fbaf7a11e23 RDI: 0000000000000007
<4>[    5.151126] RBP: 00007fbaf7a11e23 R08: 0000000000000000 R09: 0000000000000000
<4>[    5.151127] R10: 0000000000000007 R11: 0000000000000202 R12: 0000000000000000
<4>[    5.151128] R13: 00005591f5aac150 R14: 0000000000020000 R15: 00005591f4a6fe30
<4>[    5.151135] Code: e4 49 c7 c6 c0 67 0a a0 83 e8 01 4c 8d 2c c5 08 00 00 00 eb 2b 48 8b 8d a8 04 00 00 0f b7 d3 83 c3 01 29 c2 48 63 c2 48 8b 51 10 <48> 8b 14 c2 49 8b 47 10 4a 89 14 20 49 83 c4 08 4d 39 e5 74 36 
<1>[    5.151183] RIP: hda_widget_sysfs_reinit+0x13c/0x200 [snd_hda_core] RSP: ffffc900003e3b80
<4>[    5.151184] CR2: 0000000000000000
<4>[    5.151187] ---[ end trace 8765903cf6e4535d ]---
<3>[    5.283499] BUG: sleeping function called from invalid context at ./include/linux/percpu-rwsem.h:34
<3>[    5.283502] in_atomic(): 0, irqs_disabled(): 1, pid: 253, name: systemd-udevd
<4>[    5.283503] INFO: lockdep is turned off.
<4>[    5.283504] irq event stamp: 118478
<4>[    5.283511] hardirqs last  enabled at (118477): [<0000000078628d23>] __slab_alloc.isra.24.constprop.29+0x4d/0x70
<4>[    5.283515] hardirqs last disabled at (118478): [<000000006fb68814>] error_entry+0x88/0x100
<4>[    5.283518] softirqs last  enabled at (115924): [<000000007982b724>] peernet2id+0x3c/0x50
<4>[    5.283521] softirqs last disabled at (115922): [<00000000fd53c90f>] peernet2id+0x1d/0x50
<4>[    5.283524] CPU: 3 PID: 253 Comm: systemd-udevd Tainted: G      D          4.15.0-rc9-CI-CI_DRM_3673+ #1
<4>[    5.283525] Hardware name:                  /NUC6CAYB, BIOS AYAPLCEL.86A.0040.2017.0619.1722 06/19/2017
<4>[    5.283526] Call Trace:
<4>[    5.283532]  dump_stack+0x5f/0x86
<4>[    5.283536]  ___might_sleep+0x1d9/0x240
<4>[    5.283541]  exit_signals+0x1b/0x2a0
<4>[    5.283545]  do_exit+0x93/0xcb0
<4>[    5.283553]  rewind_stack_do_exit+0x17/0x20
<6>[    5.295079] input: HDA Intel PCH Mic as /devices/pci0000:00/0000:00:0e.0/sound/card0/input6
<6>[    5.295693] input: HDA Intel PCH Headphone Front as /devices/pci0000:00/0000:00:0e.0/sound/card0/input7
<6>[    5.296355] input: HDA Intel PCH Front Headphone Surround as /devices/pci0000:00/0000:00:0e.0/sound/card0/input8

This has never been reproduced