Ok, confirmed.  Just happened after switching to one of the TTYs:

Jun 16 09:03:35 zfp kernel: [205770.823411] nouveau 0000:02:00.0: DRM: resuming kernel object tree...
Jun 16 09:03:35 zfp kernel: [205770.823583] nouveau 0000:02:00.0: priv: HUB0: 10ecc0 ffffffff (1b70822c)
Jun 16 09:03:36 zfp kernel: [205770.931854] nouveau 0000:02:00.0: DRM: resuming client object trees...
Jun 16 09:03:36 zfp kernel: [205770.932031] BUG: unable to handle kernel NULL pointer dereference at 0000000000000250
Jun 16 09:03:36 zfp kernel: [205770.932035] IP: [<ffffffff816adc10>] __ww_mutex_lock+0x20/0xa0
Jun 16 09:03:36 zfp kernel: [205770.932037] PGD 0 
Jun 16 09:03:36 zfp kernel: [205770.932038] Oops: 0002 [#1] SMP
Jun 16 09:03:36 zfp kernel: [205770.932064] Modules linked in: iwlmvm iwlwifi uas usb_storage btrfs xor raid6_pq ufs qnx4 hfsplus hfs minix ntfs vfat msdos fat jfs xfs libcrc32c crc32c_generic cpuid tun xt_nat xt_tcpudp ctr ccm ecryptfs veth rfcomm ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype xt_conntrack nf_nat nf_conntrack br_netfilter bridge stp llc fuse overlay xt_multiport iptable_filter ip_tables x_tables bnep arc4 x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass mac80211 serio_raw snd_hda_codec_hdmi sg snd_hda_codec_realtek snd_hda_codec_generic snd_usb_audio snd_usbmidi_lib uvcvideo snd_hda_intel cfg80211 snd_hda_codec lpc_ich snd_hda_core snd_hwdep videobuf2_vmalloc rtsx_pci_ms memstick thinkpad_acpi joydev nvram videobuf2_memops snd_seq_midi videobuf2_v4l2 snd_seq_midi_event input_leds snd_rawmidi videobuf2_core snd_pcm snd_seq videodev snd_seq_device snd_timer media mei_me mei ie31200_edac btusb btrtl btbcm btintel bluetooth snd edac_core shpchp battery soundcore ac mac_hid nfsd sch_fq_codel auth_rpcgss nfs_acl lockd grace sunrpc parport_pc ppdev lp parport autofs4 ext4 crc16 jbd2 mbcache algif_skcipher af_alg dm_crypt dm_mod sr_mod cdrom sd_mod hid_thingm led_class hid_generic hid_logitech_hidpp hid_logitech_dj usbhid hid rtsx_pci_sdmmc crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul ahci glue_helper libahci ablk_helper cryptd libata nouveau i915 scsi_mod psmouse ehci_pci mxm_wmi ehci_hcd ttm i2c_algo_bit xhci_pci xhci_hcd rtsx_pci drm_kms_helper syscopyarea sysfillrect usbcore sysimgblt fb_sys_fops e1000e drm usb_common ptp intel_gtt pps_core agpgart thermal wmi fjes button video jitterentropy_rng drbg ansi_cprng [last unloaded: iwlwifi]
Jun 16 09:03:36 zfp kernel: [205770.932098] CPU: 3 PID: 1195 Comm: Xorg Tainted: G        W       4.7.0-040700rc2-generic #201606100641
Jun 16 09:03:36 zfp kernel: [205770.932099] Hardware name: LENOVO 20AN006LUS/20AN006LUS, BIOS GLET83WW (2.37 ) 03/31/2016
Jun 16 09:03:36 zfp kernel: [205770.932100] task: ffff8800351ac380 ti: ffff880426180000 task.ti: ffff880426180000
Jun 16 09:03:36 zfp kernel: [205770.932103] RIP: 0010:[<ffffffff816adc10>]  [<ffffffff816adc10>] __ww_mutex_lock+0x20/0xa0
Jun 16 09:03:36 zfp kernel: [205770.932103] RSP: 0018:ffff880426183908  EFLAGS: 00010246
Jun 16 09:03:36 zfp kernel: [205770.932104] RAX: 00000000ffffffff RBX: 0000000000000250 RCX: 0000000000000006
Jun 16 09:03:36 zfp kernel: [205770.932105] RDX: 0000000080000000 RSI: ffff8801cd7ac300 RDI: 0000000000000250
Jun 16 09:03:36 zfp kernel: [205770.932106] RBP: ffff880426183928 R08: 0000000000000438 R09: 0000000000000898
Jun 16 09:03:36 zfp kernel: [205770.932106] R10: 0000000000000780 R11: 0000000000000898 R12: ffff8801cd7ac300
Jun 16 09:03:36 zfp kernel: [205770.932107] R13: ffff88042448b800 R14: 0000000000000000 R15: ffff8804250d21c0
Jun 16 09:03:36 zfp kernel: [205770.932108] FS:  00007f5b5c7eba00(0000) GS:ffff88043e2c0000(0000) knlGS:0000000000000000
Jun 16 09:03:36 zfp kernel: [205770.932109] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jun 16 09:03:36 zfp kernel: [205770.932110] CR2: 0000000000000250 CR3: 00000004261e7000 CR4: 00000000001406e0
Jun 16 09:03:36 zfp kernel: [205770.932110] Stack:
Jun 16 09:03:36 zfp kernel: [205770.932112]  ffff8801cd7ac300 0000000000000250 ffff88042448b800 0000000000000000
Jun 16 09:03:36 zfp kernel: [205770.932113]  ffff880426183958 ffffffffc00a9a6e ffff880426183968 ffff8802dbaa4800
Jun 16 09:03:36 zfp kernel: [205770.932115]  ffff8802dbaa4800 ffff88042448b800 ffff880426183990 ffffffffc00aa584
Jun 16 09:03:36 zfp kernel: [205770.932115] Call Trace:
Jun 16 09:03:36 zfp kernel: [205770.932142]  [<ffffffffc00a9a6e>] drm_modeset_lock+0x4e/0xe0 [drm]
Jun 16 09:03:36 zfp kernel: [205770.932158]  [<ffffffffc00aa584>] drm_atomic_get_connector_state+0x34/0x1b0 [drm]
Jun 16 09:03:36 zfp kernel: [205770.932168]  [<ffffffffc01d9271>] __drm_atomic_helper_set_config+0x281/0x330 [drm_kms_helper]
Jun 16 09:03:36 zfp kernel: [205770.932175]  [<ffffffffc01da491>] restore_fbdev_mode+0x221/0x260 [drm_kms_helper]
Jun 16 09:03:36 zfp kernel: [205770.932190]  [<ffffffffc00a9b9a>] ? drm_modeset_lock_all_ctx+0x9a/0xb0 [drm]
Jun 16 09:03:36 zfp kernel: [205770.932197]  [<ffffffffc01dc983>] drm_fb_helper_restore_fbdev_mode_unlocked+0x33/0x80 [drm_kms_helper]
Jun 16 09:03:36 zfp kernel: [205770.932204]  [<ffffffffc01dc9fd>] drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper]
Jun 16 09:03:36 zfp kernel: [205770.932235]  [<ffffffffc0358c0a>] intel_fbdev_set_par+0x1a/0x60 [i915]
Jun 16 09:03:36 zfp kernel: [205770.932238]  [<ffffffff813eb165>] ? fb_set_var+0x2f5/0x470
Jun 16 09:03:36 zfp kernel: [205770.932239]  [<ffffffff813eb0a6>] fb_set_var+0x236/0x470
Jun 16 09:03:36 zfp kernel: [205770.932243]  [<ffffffff810b6196>] ? update_curr+0x66/0x180
Jun 16 09:03:36 zfp kernel: [205770.932245]  [<ffffffff810b298c>] ? __enqueue_entity+0x6c/0x70
Jun 16 09:03:36 zfp kernel: [205770.932247]  [<ffffffff810b96e5>] ? enqueue_entity+0x2b5/0x920
Jun 16 09:03:36 zfp kernel: [205770.932250]  [<ffffffff813e139f>] fbcon_blank+0x30f/0x350
Jun 16 09:03:36 zfp kernel: [205770.932253]  [<ffffffff8102c97b>] ? __switch_to+0x4cb/0x5c0
Jun 16 09:03:36 zfp kernel: [205770.932255]  [<ffffffff8146f163>] do_unblank_screen+0xd3/0x1a0
Jun 16 09:03:36 zfp kernel: [205770.932257]  [<ffffffff81464899>] complete_change_console+0x59/0xe0
Jun 16 09:03:36 zfp kernel: [205770.932259]  [<ffffffff81465030>] vt_ioctl+0x710/0x12f0
Jun 16 09:03:36 zfp kernel: [205770.932261]  [<ffffffff814590df>] tty_ioctl+0x35f/0xc80
Jun 16 09:03:36 zfp kernel: [205770.932264]  [<ffffffff814c55c8>] ? __pm_runtime_suspend+0x68/0x80
Jun 16 09:03:36 zfp kernel: [205770.932267]  [<ffffffff81237de1>] do_vfs_ioctl+0xa1/0x5b0
Jun 16 09:03:36 zfp kernel: [205770.932270]  [<ffffffff8106ab65>] ? __do_page_fault+0x205/0x4d0
Jun 16 09:03:36 zfp kernel: [205770.932272]  [<ffffffff81238369>] SyS_ioctl+0x79/0x90
Jun 16 09:03:36 zfp kernel: [205770.932274]  [<ffffffff816b0176>] entry_SYSCALL_64_fastpath+0x1e/0xa8
Jun 16 09:03:36 zfp kernel: [205770.932289] Code: e9 4c ff ff ff e8 01 2b 9d ff 90 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 54 53 49 89 f4 48 89 fb e8 55 e4 ff ff b8 ff ff ff ff <f0> 0f c1 03 83 e8 01 78 2b 41 83 44 24 10 01 4c 89 63 28 0f ae 
Jun 16 09:03:36 zfp kernel: [205770.932291] RIP  [<ffffffff816adc10>] __ww_mutex_lock+0x20/0xa0
Jun 16 09:03:36 zfp kernel: [205770.932291]  RSP <ffff880426183908>
Jun 16 09:03:36 zfp kernel: [205770.932292] CR2: 0000000000000250
Jun 16 09:03:36 zfp kernel: [205770.932293] ---[ end trace cd02b867c374a3be ]---