kernel null pointer dereference

[Ken Corbin]

System started freezing up a couple days ago. After the latest one, I looked at the syslog file and found what appears to be a kernel bug report.

May 5 18:06:03 corbin-goul kernel: [ 4650.769677] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
May 5 18:06:03 corbin-goul kernel: [ 4650.769694] IP: rm_hole+0x19/0x70 [drm]
May 5 18:06:03 corbin-goul kernel: [ 4650.769696] PGD 0 P4D 0
May 5 18:06:03 corbin-goul kernel: [ 4650.769698] Oops: 0002 [#1] SMP PTI
May 5 18:06:03 corbin-goul kernel: [ 4650.769700] Modules linked in: nls_iso8859_1 snd_hda_codec_realtek snd_hda_codec_hdmi intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_hda_codec_generic snd_hda_intel snd
_hda_codec kvm snd_hda_core snd_hwdep snd_pcm irqbypass mei_me intel_cstate mei intel_rapl_perf snd_seq_midi input_leds snd_seq_midi_event serio_raw snd_rawmidi snd_seq snd_seq_device snd_timer lpc_ich snd shpchp soundcore mac_hid s
ch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi parport_pc ppdev lp parport ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq a
sync_xor async_tx xor raid6_pq libcrc32c raid0 multipath linear raid1 hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc i915
May 5 18:06:03 corbin-goul kernel: [ 4650.769733] aesni_intel i2c_algo_bit aes_x86_64 crypto_simd drm_kms_helper glue_helper cryptd syscopyarea sysfillrect sysimgblt r8169 fb_sys_fops ahci mii drm libahci sata_inic162x video
May 5 18:06:03 corbin-goul kernel: [ 4650.769743] CPU: 0 PID: 8713 Comm: kworker/0:0 Not tainted 4.15.0-48-generic #51-Ubuntu
May 5 18:06:03 corbin-goul kernel: [ 4650.769744] Hardware name: Gigabyte Technology Co., Ltd. H87M-D3H/H87M-D3H, BIOS F3 04/24/2013
May 5 18:06:03 corbin-goul kernel: [ 4650.769770] Workqueue: events __i915_gem_free_work [i915]
May 5 18:06:03 corbin-goul kernel: [ 4650.769778] RIP: 0010:rm_hole+0x19/0x70 [drm]
May 5 18:06:03 corbin-goul kernel: [ 4650.769779] RSP: 0018:ffff95fb81f2bd20 EFLAGS: 00010202
May 5 18:06:03 corbin-goul kernel: [ 4650.769780] RAX: 0000000000000000 RBX: ffff89d51f1382c0 RCX: 0000000000000000
May 5 18:06:03 corbin-goul kernel: [ 4650.769781] RDX: 0000000000000000 RSI: ffff89d765cf8b40 RDI: ffff89d51f138318
May 5 18:06:03 corbin-goul kernel: [ 4650.769782] RBP: ffff95fb81f2bd28 R08: ffff89d5e7b71bc0 R09: 0000000000000000
May 5 18:06:03 corbin-goul kernel: [ 4650.769783] R10: ffff95fb81f2bde0 R11: 0000000000000001 R12: ffff89d765cf8b00
May 5 18:06:03 corbin-goul kernel: [ 4650.769784] R13: 0000000000000000 R14: ffff89d51f1382e0 R15: ffff89d75f6c37c8
May 5 18:06:03 corbin-goul kernel: [ 4650.769786] FS: 0000000000000000(0000) GS:ffff89d77e200000(0000) knlGS:0000000000000000
May 5 18:06:03 corbin-goul kernel: [ 4650.769787] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
May 5 18:06:03 corbin-goul kernel: [ 4650.769788] CR2: 0000000000000008 CR3: 00000002eac0a002 CR4: 00000000001606f0
May 5 18:06:03 corbin-goul kernel: [ 4650.769789] Call Trace:
May 5 18:06:03 corbin-goul kernel: [ 4650.769797] drm_mm_remove_node+0x29d/0x360 [drm]
May 5 18:06:03 corbin-goul kernel: [ 4650.769801] ? __internal_add_timer+0x1f/0x60
May 5 18:06:03 corbin-goul kernel: [ 4650.769816] i915_vma_remove+0x3a/0x100 [i915]
May 5 18:06:03 corbin-goul kernel: [ 4650.769830] i915_vma_unbind+0x1cd/0x370 [i915]
May 5 18:06:03 corbin-goul kernel: [ 4650.769843] i915_vma_close+0x7d/0xa0 [i915]
May 5 18:06:03 corbin-goul kernel: [ 4650.769856] __i915_gem_free_objects+0xa3/0x2c0 [i915]
May 5 18:06:03 corbin-goul kernel: [ 4650.769867] __i915_gem_free_work+0x60/0x90 [i915]
May 5 18:06:03 corbin-goul kernel: [ 4650.769870] process_one_work+0x1de/0x410
May 5 18:06:03 corbin-goul kernel: [ 4650.769872] worker_thread+0x32/0x410
May 5 18:06:03 corbin-goul kernel: [ 4650.769874] kthread+0x121/0x140
May 5 18:06:03 corbin-goul kernel: [ 4650.769876] ? process_one_work+0x410/0x410
May 5 18:06:03 corbin-goul kernel: [ 4650.769878] ? kthread_create_worker_on_cpu+0x70/0x70
May 5 18:06:03 corbin-goul kernel: [ 4650.769881] ret_from_fork+0x35/0x40
May 5 18:06:03 corbin-goul kernel: [ 4650.769882] Code: 00 00 00 45 31 d2 eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 8b 57 30 48 8b 47 38 48 89 fb 48 8d 7f 58 <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 47 d8
May 5 18:06:03 corbin-goul kernel: [ 4650.769909] RIP: rm_hole+0x19/0x70 [drm] RSP: ffff95fb81f2bd20
May 5 18:06:03 corbin-goul kernel: [ 4650.769910] CR2: 0000000000000008
May 5 18:06:03 corbin-goul kernel: [ 4650.769912] ---[ end trace 4488bf4278af9827 ]---

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-48-generic 4.15.0-48.51
ProcVersionSignature: Ubuntu 4.15.0-48.51-generic 4.15.18
Uname: Linux 4.15.0-48-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: ken 2604 F.... pulseaudio
 /dev/snd/controlC1: ken 2604 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Sun May 5 18:18:41 2019
HibernationDevice: RESUME=UUID=d9769aee-0f6e-4d98-8376-a6ba3aa6edf8
InstallationDate: Installed on 2018-10-18 (199 days ago)
InstallationMedia: Ubuntu-Server 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
IwConfig:
 lo no wireless extensions.

 enp2s0 no wireless extensions.
MachineType: Gigabyte Technology Co., Ltd. H87M-D3H
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-48-generic root=/dev/mapper/system-Ubuntu--18.04.1 ro
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-48-generic N/A
 linux-backports-modules-4.15.0-48-generic N/A
 linux-firmware 1.173.5
RfKill:

SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/24/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F3
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: H87M-D3H
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF3:bd04/24/2013:svnGigabyteTechnologyCo.,Ltd.:pnH87M-D3H:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnH87M-D3H:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: H87M-D3H
dmi.product.version: To be filled by O.E.M.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Po-Hsu Lin (cypressyew)]

Hello,
can this issue be reproduced? How to trigger it?

Also, do you have this issue with an older Bionic kernel? (like 4.15.0-47)
Thanks.

[Ken Corbin (kencx)]

No I can not reproduce this. Which is not that surprising, deep kernel bugs are unlikely to be correlated with anything the user is doing at the UI level. System is still crashing sporadically, they do not occur on any of my other systems, nor did they happen on this system before a certain date, which inclines me to claim that they were not happening with older kernels.

It did lock up again this morning. Unfortunately the last 5 minutes of the syslog file were corrupted and contained no useful information, so I could not tell you if it was the same problem or not.

[Darin (newhoa)]

I just had this happen to me. I'll attach the relevant part of the syslog. If there's any more info that I could give that would help just let me know. Using Kernel 5.3.0-10-generic from Eoan.

Oct 5 18:02:26 kernel: [493310.092229] BUG: kernel NULL pointer dereference, address: 00000000000002ac
Oct 5 18:02:26 kernel: [493310.092235] #PF: supervisor read access in kernel mode
Oct 5 18:02:26 kernel: [493310.092237] #PF: error_code(0x0000) - not-present page
Oct 5 18:02:26 kernel: [493310.092239] PGD 0 P4D 0
Oct 5 18:02:26 kernel: [493310.092244] Oops: 0000 [#1] SMP NOPTI
Oct 5 18:02:26 kernel: [493310.092248] CPU: 0 PID: 2063 Comm: kworker/u32:3 Not tainted 5.3.0-10-generic #11-Ubuntu
Oct 5 18:02:26 kernel: [493310.092250] Hardware name: Micro-Star International Co., Ltd MS-7C02/B450 TOMAHAWK (MS-7C02), BIOS 1.50 01/25/2019
Oct 5 18:02:26 kernel: [493310.092266] Workqueue: events_unbound commit_work [drm_kms_helper]
Oct 5 18:02:26 kernel: [493310.092409] RIP: 0010:dc_stream_log+0x12/0xc0 [amdgpu]
Oct 5 18:02:26 kernel: [493310.092414] Code: 83 f1 01 0f b6 c9 e8 8d 92 35 d3 e9 71 ff ff ff 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 f2 bf 04 00 00 00 48 89 e5 53 <8b> 86 ac 02 00 00 48 89 f3 8b 8e 0c 01 00 00 50 8b 86 28 01 00 00
Oct 5 18:02:26 kernel: [493310.092418] RSP: 0018:ffffb81e08617b80 EFLAGS: 00010202
Oct 5 18:02:26 kernel: [493310.092422] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000002
Oct 5 18:02:26 kernel: [493310.092424] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
Oct 5 18:02:26 kernel: [493310.092427] RBP: ffffb81e08617b88 R08: 0000000000000000 R09: 0000000000000001
Oct 5 18:02:26 kernel: [493310.092430] R10: ffff9c49fea173c8 R11: 0000000000000000 R12: ffff9c43047a0000
Oct 5 18:02:26 kernel: [493310.092432] R13: ffff9c49f2e00000 R14: ffff9c43047a0000 R15: ffff9c49e90c0000
Oct 5 18:02:26 kernel: [493310.092436] FS: 0000000000000000(0000) GS:ffff9c49fea00000(0000) knlGS:0000000000000000
Oct 5 18:02:26 kernel: [493310.092439] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 5 18:02:26 kernel: [493310.092441] CR2: 00000000000002ac CR3: 00000007ecba0000 CR4: 00000000003406f0
Oct 5 18:02:26 kernel: [493310.092445] DR0: 000000001004c7c0 DR1: 0000000010183c60 DR2: 00000000100f14a0
Oct 5 18:02:26 kernel: [493310.092447] DR3: 00000000100efd10 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Oct 5 18:02:26 kernel: [493310.092449] Call Trace:
Oct 5 18:02:26 kernel: [493310.092611] dc_commit_state+0x7e/0xb0 [amdgpu]
Oct 5 18:02:26 kernel: [493310.092745] amdgpu_dm_atomic_commit_tail+0x3bf/0xfb0 [amdgpu]
Oct 5 18:02:26 kernel: [493310.092753] ? cpumask_next_and+0x1e/0x20
Oct 5 18:02:26 kernel: [493310.092759] ? free_one_page+0xb7/0x4b0
Oct 5 18:02:26 kernel: [493310.092764] ? __switch_to_asm+0x40/0x70
Oct 5 18:02:26 kernel: [493310.092767] ? __switch_to_asm+0x34/0x70
Oct 5 18:02:26 kernel: [493310.092770] ? __switch_to_asm+0x40/0x70
Oct 5 18:02:26 kernel: [493310.092773] ? __switch_to_asm+0x34/0x70
Oct 5 18:02:26 kernel: [493310.092776] ? __switch_to_asm+0x40/0x70
Oct 5 18:02:26 kernel: [493310.092779] ? __switch_to_asm+0x34/0x...

[Ken Corbin (kencx)]

A month or so after reporting this, amid a frustrating series of unpredictable lockups, I figured out how to run memtest which indicated I had a bad memory card. Since replacing it, I have had no further problems.

[Darin (newhoa)]

Thanks for the response. What version of memtest did you run and how long did you have to run it? You ended up having a bad stick of ram? Did you have to test each one individually?

I just built this PC a few months ago and after building ran memtest for a whole day without problem but maybe I'll have to try it again. My log mentions amdgpu after the crash each time so it may be a problem with the graphics card or amdgpu driver. There are a few similar bug posts I've found indicating it might be an amdgpu driver issue. Here are a few.

https://bugzilla.kernel.org/show_bug.cgi?id=204181

https://bugs.freedesktop.org/show_bug.cgi?id=106194

https://bugs.freedesktop.org/show_bug.cgi?id=111234

[Samuel Woon (samuel-w1-deactivatedaccount)]

I'm also encountering this issue, only on 19.10. My GPU is a RX 580. Tested memory for 8 hours using livecd memtest
 BUG: kernel NULL pointer dereference, address: 00000000000002ac
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP NOPTI
 CPU: 9 PID: 340 Comm: kworker/u64:9 Tainted: G W OE 5.3.0-18-generic #19-Ubuntu
 Hardware name: System manufacturer System Product Name/CROSSHAIR VI HERO, BIOS 7501 09/23/2019
 Workqueue: events_unbound commit_work [drm_kms_helper]
 RIP: 0010:dc_stream_log+0x12/0xc0 [amdgpu]
 Code: 83 f1 01 0f b6 c9 e8 8d c2 81 c7 e9 71 ff ff ff 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 f2 bf 04 00 00 00 48 89 e5 53 <8b> 86 ac 02 00 00 48 89 f3 8b 8e 0c 01 00 00 50 8b 86 28 01 00 00
 RSP: 0018:ffffc017c12d7b80 EFLAGS: 00010202
 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000002
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
 RBP: ffffc017c12d7b88 R08: 0000000000000000 R09: 0000000000000001
 R10: ffff9efbcea573c8 R11: 0000000000000000 R12: ffff9efa9f840000
 R13: ffff9efbbae30000 R14: ffff9efa9f840000 R15: ffff9efbbad40000
 FS: 0000000000000000(0000) GS:ffff9efbcea40000(0000) knlGS:0000000000000000
 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00000000000002ac CR3: 00000003fe050000 CR4: 00000000003406e0
 Call Trace:
  dc_commit_state+0x7e/0xb0 [amdgpu]
  amdgpu_dm_atomic_commit_tail+0x3bf/0xfb0 [amdgpu]
  ? cpumask_next_and+0x1e/0x20
  ? free_one_page+0xb7/0x4b0
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? _cond_resched+0x19/0x30
  ? wait_for_completion_timeout+0x3a/0x120
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70
  commit_tail+0x41/0x70 [drm_kms_helper]
  ? commit_tail+0x41/0x70 [drm_kms_helper]
  commit_work+0x12/0x20 [drm_kms_helper]
  process_one_work+0x1db/0x380
  worker_thread+0x4d/0x400
  kthread+0x104/0x140
  ? process_one_work+0x380/0x380
  ? kthread_park+0x80/0x80
  ret_from_fork+0x22/0x40
 Modules linked in: pci_stub vboxpci(OE) vboxnetadp(OE) xfrm_user vboxnetflt(OE) xfrm4_tunnel tunnel4 ipcomp xfrm_ipcomp esp4 l2tp_ppp l2tp_netlink l2tp_core ah4 ip6_udp_tunnel vboxdrv(OE) udp_tunnel af_key xfrm_algo pppox nls_iso8859_1 snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hda_core joydev snd_hwdep input_leds snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer edac_mce_amd kvm_amd kvm irqbypass eeepc_wmi asus_wmi sparse_keymap video wmi_bmof snd k10temp ccp soundcore mac...

[Dmitriy Morozov (dimidr0l)]

[Wed Feb 5 20:09:17 2020] vfio-pci 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[Wed Feb 5 20:09:17 2020] BUG: kernel NULL pointer dereference, address: 0000000000000008
[Wed Feb 5 20:09:17 2020] #PF: supervisor write access in kernel mode
[Wed Feb 5 20:09:17 2020] #PF: error_code(0x0002) - not-present page
[Wed Feb 5 20:09:17 2020] PGD 0 P4D 0
[Wed Feb 5 20:09:17 2020] Oops: 0002 [#1] SMP NOPTI
[Wed Feb 5 20:09:17 2020] CPU: 3 PID: 3306 Comm: tee Not tainted 5.3.0-28-generic #30~18.04.1-Ubuntu
[Wed Feb 5 20:09:17 2020] Hardware name: System manufacturer System Product Name/PRIME H310T, BIOS 2602 07/24/2019
[Wed Feb 5 20:09:17 2020] RIP: 0010:mutex_lock+0x1d/0x40
[Wed Feb 5 20:09:17 2020] Code: 5d c3 90 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb e8 9e e6 ff ff 65 48 8b 14 25 c0 6b 01 00 31 c0 <f0> 48 0f b1 13 75 03 5b 5d c3 48 89 df e8 b1 ff ff ff 5b 5d c3 0f
[Wed Feb 5 20:09:17 2020] RSP: 0018:ffff9d4a42817d38 EFLAGS: 00010246
[Wed Feb 5 20:09:17 2020] RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000000000
[Wed Feb 5 20:09:17 2020] RDX: ffff8cd6d8f6da00 RSI: 0000000000000000 RDI: 0000000000000008
[Wed Feb 5 20:09:17 2020] RBP: ffff9d4a42817d40 R08: ffff8cd6dbc036c0 R09: ffff8cd6dbc03718
[Wed Feb 5 20:09:17 2020] R10: 0000000000000000 R11: ffffffff8285d518 R12: 0000000000000000
[Wed Feb 5 20:09:17 2020] R13: ffffffffc05b0000 R14: ffff9d4a42817ee8 R15: fffffffffffffff2
[Wed Feb 5 20:09:17 2020] FS: 00007f32cfe5f540(0000) GS:ffff8cd6ddd80000(0000) knlGS:0000000000000000
[Wed Feb 5 20:09:17 2020] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[Wed Feb 5 20:09:17 2020] CR2: 0000000000000008 CR3: 0000000458984003 CR4: 00000000003626e0
[Wed Feb 5 20:09:17 2020] Call Trace:
[Wed Feb 5 20:09:17 2020] snd_sof_ipc_free+0x20/0x40 [snd_sof]
[Wed Feb 5 20:09:17 2020] snd_sof_device_remove+0x33/0xa0 [snd_sof]
[Wed Feb 5 20:09:17 2020] sof_pci_remove+0x19/0x30 [sof_pci_dev]
[Wed Feb 5 20:09:17 2020] pci_device_remove+0x3e/0xc0
[Wed Feb 5 20:09:17 2020] device_release_driver_internal+0xe0/0x1b0
[Wed Feb 5 20:09:17 2020] device_driver_detach+0x14/0x20
[Wed Feb 5 20:09:17 2020] unbind_store+0xd1/0x130
[Wed Feb 5 20:09:17 2020] drv_attr_store+0x27/0x40
[Wed Feb 5 20:09:17 2020] sysfs_kf_write+0x3c/0x50
[Wed Feb 5 20:09:17 2020] kernfs_fop_write+0x125/0x1a0
[Wed Feb 5 20:09:17 2020] __vfs_write+0x1b/0x40
[Wed Feb 5 20:09:17 2020] vfs_write+0xb1/0x1a0
[Wed Feb 5 20:09:17 2020] ksys_write+0xa7/0xe0
[Wed Feb 5 20:09:17 2020] __x64_sys_write+0x1a/0x20
[Wed Feb 5 20:09:17 2020] do_syscall_64+0x5a/0x130
[Wed Feb 5 20:09:17 2020] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[Wed Feb 5 20:09:17 2020] RIP: 0033:0x7f32cf963154
[Wed Feb 5 20:09:17 2020] Code: 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8d 05 b1 07 2e 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 41 54 55 49 89 d4 53 48 89 f5
[Wed Feb 5 20:09:17 2020] RSP: 002b:00007ffeacffedb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[Wed Feb 5 20:09:17 2020] RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f32cf963154
[Wed...