Backtrace

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0 
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 39774 Comm: kworker/u16:8 Not tainted 5.17.4-200.fc35.x86_64 #1
Hardware name: LENOVO 81Q9/LNVNB161216, BIOS AUCN59WW 02/24/2021
Workqueue: netns cleanup_net
RIP: 0010:rb_erase+0x106/0x350
Code: 00 00 48 89 10 48 8b 02 a8 01 0f 84 35 02 00 00 48 83 e0 fc 75 01 c3 48 89 d1 48 89 c2 48 8b 42 08 48 39 c8 75 af 48 8b 42 10 <f6> 00 01 0f 84 1d 01 00 00 48 8b 70 10 48 85 f6 74 05 f6 06 01 74
RSP: 0018:ffffb77209f5bda0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff90dc6deba900 RCX: 0000000000000000
RDX: ffff90d9a15c52d0 RSI: ffff90d8af4c5550 RDI: ffff90d9a15c5290
RBP: ffff90d9a15c5240 R08: ffff90dc6deba950 R09: 0000000000000000
R10: ffff90d9a15c52b0 R11: 0000000000000000 R12: ffff90dcd9788540
R13: ffffb77209f5be50 R14: ffff90d9a162b2a0 R15: ffff90d9a162b254
FS:  0000000000000000(0000) GS:ffff90dd1a800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001410d2004 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
 <TASK>
 drop_sysctl_table+0xa1/0x140
 ? preempt_count_add+0x68/0xa0
 unregister_sysctl_table.part.0+0x3b/0x90
 ipv6_frags_exit_net+0x1a/0x40
 ops_exit_list+0x30/0x60
 cleanup_net+0x203/0x390
 process_one_work+0x1e2/0x3b0
 worker_thread+0x50/0x3a0
 ? rescuer_thread+0x370/0x370
 kthread+0xe5/0x110
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x1f/0x30
 </TASK>
Modules linked in: snd_usb_audio snd_usbmidi_lib snd_rawmidi r8153_ecm cdc_ether usbnet r8152 uas usb_storage mii xt_nat veth xt_conntrack xt_MASQUERADE nf_conntrack_netlink xt_addrtype nft_compat br_netfilter bridge stp llc uinput rfcomm snd_seq_dummy snd_hrtimer nft_objref nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables nfnetlink qrtr bnep sunrpc snd_soc_skl_hda_dsp snd_soc_intel_hda_dsp_common snd_soc_hdac_hdmi vfat fat squashfs loop snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_soc_dmic snd_sof_pci_intel_icl snd_sof_intel_hda_common soundwire_intel soundwire_generic_allocation soundwire_cadence snd_sof_intel_hda snd_sof_pci snd_sof_xtensa_dsp snd_sof snd_soc_hdac_hda snd_hda_ext_core snd_soc_acpi_intel_match snd_soc_acpi soundwire_bus ledtrig_audio snd_soc_core
 iwlmvm snd_compress ac97_bus snd_pcm_dmaengine snd_hda_intel intel_tcc_cooling x86_pkg_temp_thermal snd_intel_dspcfg snd_intel_sdw_acpi intel_powerclamp mac80211 snd_hda_codec coretemp kvm_intel snd_hda_core snd_hwdep libarc4 kvm uvcvideo snd_seq snd_seq_device iTCO_wdt videobuf2_vmalloc intel_pmc_bxt iTCO_vendor_support mei_hdcp mei_pxp intel_rapl_msr snd_pcm irqbypass btusb iwlwifi rapl videobuf2_memops btrtl intel_cstate snd_timer videobuf2_v4l2 btbcm intel_uncore btintel snd videobuf2_common iwlmei btmtk i2c_i801 think_lmi pcspkr firmware_attributes_class intel_wmi_thunderbolt wmi_bmof i2c_smbus processor_thermal_device_pci_legacy soundcore bluetooth mei_me videodev hid_sensor_accel_3d processor_thermal_device cfg80211 hid_sensor_trigger processor_thermal_rfim hid_sensor_iio_common processor_thermal_mbox processor_thermal_rapl industrialio_triggered_buffer intel_rapl_common kfifo_buf idma64 joydev mc mei thunderbolt ecdh_generic industrialio intel_soc_dts_iosf
 ideapad_laptop sparse_keymap platform_profile int3403_thermal rfkill soc_button_array int340x_thermal_zone int3400_thermal acpi_thermal_rel acpi_tad acpi_pad zram ip_tables hid_sensor_hub intel_ishtp_hid i915 i2c_algo_bit drm_kms_helper cec wacom ttm nvme intel_ish_ipc ucsi_acpi hid_multitouch crct10dif_pclmul crc32_pclmul crc32c_intel drm ghash_clmulni_intel nvme_core typec_ucsi serio_raw typec i2c_hid_acpi intel_ishtp wmi i2c_hid video pinctrl_icelake ipmi_devintf ipmi_msghandler fuse
CR2: 0000000000000000