Backtrace

BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0 
Oops: 0002 [#2] SMP PTI
CPU: 0 PID: 3195 Comm: systemd-coredum Tainted: G      D W         5.11.18-300.fc34.x86_64 #1
Hardware name: ASUSTeK COMPUTER INC. X442URR/X442URR, BIOS X442URR.308 05/24/2019
RIP: 0010:blk_flush_plug_list+0x6f/0x100
Code: 00 00 00 00 ad de 49 bc 22 01 00 00 00 00 ad de 49 8b 46 10 48 8b 34 24 48 39 f0 74 5b 49 8b 4e 10 49 8b 56 18 48 8b 44 24 08 <48> 89 59 08 48 89 4c 24 08 48 89 02 48 89 50 08 49 89 76 10 49 89
RSP: 0018:ffffb7f001dc7da0 EFLAGS: 00010203
RAX: ffffb7f001dc7da8 RBX: ffffb7f001dc7da8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffb7f001dc7be0 RDI: ffffb7f001dc7bd0
RBP: 0000000000000001 R08: ffffffffa0b53198 R09: ffffffffa0b53198
R10: 000000000000023e R11: 0000000000000000 R12: dead000000000122
R13: dead000000000100 R14: ffffb7f001dc7bd0 R15: ffff9ae2870a5c30
FS:  0000000000000000(0000) GS:ffff9ae3e6c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 0000000225a10005 CR4: 00000000003706f0
Call Trace:
 schedule+0x83/0xb0
 synchronize_rcu_expedited+0x1be/0x330
 ? cond_synchronize_rcu+0x20/0x20
 ? finish_wait+0x80/0x80
 ? umount_tree+0x227/0x320
 namespace_unlock+0xaa/0x170
 put_mnt_ns+0x69/0x90
 free_nsproxy+0x17/0x1b0
 do_exit+0x35a/0xac0
 ? ksys_read+0x4f/0xc0
 rewind_stack_do_exit+0x17/0x20
RIP: 0033:0x7f9d4d692912
Code: Unable to access opcode bytes at RIP 0x7f9d4d6928e8.
RSP: 002b:00007fffedd88988 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f9d4d692912
RDX: 0000000000020000 RSI: 00007f9d4c33e010 RDI: 0000000000000006
RBP: 0000000000000006 R08: 0000000000000000 R09: 0000000000020000
R10: 00007f9d4cdc58a0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f9d4c33e010 R15: 00007fffedd88a30
Modules linked in: uinput rfcomm snd_seq_dummy snd_hrtimer xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 ip6table_mangle ip6table_nat ip6table_filter ip6_tables iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bridge stp llc ccm cmac bnep sunrpc vfat fat snd_soc_skl snd_soc_hdac_hda snd_hda_ext_core snd_soc_sst_ipc snd_hda_codec_hdmi snd_soc_sst_dsp snd_soc_acpi_intel_match snd_hda_codec_realtek snd_hda_codec_generic snd_soc_acpi uvcvideo ledtrig_audio videobuf2_vmalloc snd_hda_intel videobuf2_memops videobuf2_v4l2 snd_intel_dspcfg videobuf2_common soundwire_intel videodev soundwire_generic_allocation snd_soc_core snd_compress snd_pcm_dmaengine btusb mc soundwire_cadence rtsx_usb_ms snd_hda_codec memstick btrtl btbcm iTCO_wdt x86_pkg_temp_thermal ath10k_pci btintel intel_pmc_bxt intel_powerclamp bluetooth snd_hda_core coretemp ath10k_core ac97_bus iTCO_vendor_support ecdh_generic snd_hwdep snd_seq snd_seq_device
 r8169 kvm_intel ecc spi_pxa2xx_platform ee1004 mac80211 dw_dmac intel_rapl_msr mei_hdcp snd_pcm snd_timer joydev kvm snd ath soundcore cfg80211 irqbypass processor_thermal_device asus_nb_wmi processor_thermal_rfim int3403_thermal processor_thermal_mbox asus_wmi processor_thermal_rapl sparse_keymap rapl libarc4 intel_rapl_common rfkill int340x_thermal_zone i2c_i801 intel_xhci_usb_role_switch mei_me intel_cstate roles intel_uncore intel_pch_thermal intel_soc_dts_iosf pcspkr idma64 int3400_thermal i2c_smbus mei acpi_thermal_rel wmi_bmof acpi_pad asus_wireless zram ip_tables rtsx_usb_sdmmc mmc_core rtsx_usb i915 nouveau hid_multitouch drm_ttm_helper ttm i2c_algo_bit drm_kms_helper crct10dif_pclmul crc32_pclmul crc32c_intel mxm_wmi cec drm ghash_clmulni_intel uas serio_raw usb_storage i2c_hid wmi video pinctrl_sunrisepoint fuse
CR2: 0000000000000008