[    2.094753] ip (255) used greatest stack depth: 12136 bytes left
[    4.727060] BUG: kernel NULL pointer dereference, address: 0000000000000000
[    4.727137] #PF: supervisor write access in kernel mode
[    4.727190] #PF: error_code(0x0002) - not-present page
[    4.727224] PGD 0 P4D 0 
[    4.727250] Oops: Oops: 0002 [#1] SMP
[    4.727289] CPU: 0 UID: 0 PID: 68 Comm: kworker/u16:1 Not tainted 6.18.0-rc5-virtme #1 PREEMPT(voluntary) 
[    4.727367] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    4.727417] Workqueue: netns cleanup_net
[    4.727457] RIP: 0010:work_grab_pending+0x2f/0x1b0
[    4.727514] Code: 83 e6 01 41 57 41 56 4c 8d 77 20 41 55 41 54 41 89 f4 55 48 89 d5 53 48 89 fb 9c 58 fa 48 89 45 00 45 85 e4 0f 85 8a 00 00 00 <f0> 48 0f ba 2b 00 41 0f 92 c5 72 0e 5b 44 89 e8 5d 41 5c 41 5d 41
[    4.727659] RSP: 0018:ffffb88b8025fbb8 EFLAGS: 00010046
[    4.727711] RAX: 0000000000000246 RBX: 0000000000000000 RCX: 0000000000000800
[    4.727774] RDX: ffffb88b8025fbf0 RSI: 0000000000000000 RDI: 0000000000000000
[    4.727846] RBP: ffffb88b8025fbf0 R08: ffff9d73413a4d83 R09: 0000000000000002
[    4.727905] R10: ffff9d737ec28640 R11: ffff9d73413a4590 R12: 0000000000000000
[    4.727963] R13: ffffb88b8025fce8 R14: 0000000000000020 R15: ffffb88b8025fdf0
[    4.728024] FS:  0000000000000000(0000) GS:ffff9d73cf3d8000(0000) knlGS:0000000000000000
[    4.728086] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.728143] CR2: 0000000000000000 CR3: 0000000006deb006 CR4: 0000000000772ef0
[    4.728198] PKRU: 55555554
[    4.728220] Call Trace:
[    4.728239]  <TASK>
[    4.728273]  __cancel_work+0x29/0xe0
[    4.728312]  ? queue_delayed_work_on+0x54/0x60
[    4.728355]  __cancel_work_sync+0x16/0x80
[    4.728392]  __dev_close_many+0x11b/0x280
[    4.728426]  netif_close_many+0x98/0x160
[    4.728461]  unregister_netdevice_many_notify+0x1d8/0xa50
[    4.728504]  ? unregister_netdevice_queue+0x29/0xe0
[    4.728563]  default_device_exit_batch+0x29b/0x300
[    4.728612]  ops_undo_list+0xec/0x1f0
[    4.728648]  cleanup_net+0x1b7/0x2b0
[    4.728681]  process_one_work+0x162/0x380
[    4.728718]  worker_thread+0x299/0x3c0
[    4.728761]  ? rescuer_thread+0x4c0/0x4c0
[    4.728798]  kthread+0x101/0x1f0
[    4.728834]  ? kthreads_online_cpu+0x110/0x110
[    4.728882]  ? kthreads_online_cpu+0x110/0x110
[    4.728920]  ret_from_fork+0x11c/0x140
[    4.728959]  ? kthreads_online_cpu+0x110/0x110
[    4.729002]  ret_from_fork_asm+0x11/0x20
[    4.729040]  </TASK>
[    4.729070] Modules linked in: nft_synproxy nf_synproxy_core nft_ct nf_tables veth nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4
[    4.729163] CR2: 0000000000000000
[    4.729190] ---[ end trace 0000000000000000 ]---
[    4.729233] RIP: 0010:work_grab_pending+0x2f/0x1b0
[    4.729277] Code: 83 e6 01 41 57 41 56 4c 8d 77 20 41 55 41 54 41 89 f4 55 48 89 d5 53 48 89 fb 9c 58 fa 48 89 45 00 45 85 e4 0f 85 8a 00 00 00 <f0> 48 0f ba 2b 00 41 0f 92 c5 72 0e 5b 44 89 e8 5d 41 5c 41 5d 41
[    4.729411] RSP: 0018:ffffb88b8025fbb8 EFLAGS: 00010046
[    4.729454] RAX: 0000000000000246 RBX: 0000000000000000 RCX: 0000000000000800
[    4.729513] RDX: ffffb88b8025fbf0 RSI: 0000000000000000 RDI: 0000000000000000
[    4.729591] RBP: ffffb88b8025fbf0 R08: ffff9d73413a4d83 R09: 0000000000000002
[    4.729646] R10: ffff9d737ec28640 R11: ffff9d73413a4590 R12: 0000000000000000
[    4.729700] R13: ffffb88b8025fce8 R14: 0000000000000020 R15: ffffb88b8025fdf0
[    4.729758] FS:  0000000000000000(0000) GS:ffff9d73cf3d8000(0000) knlGS:0000000000000000
[    4.729820] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.729876] CR2: 0000000000000000 CR3: 0000000006deb006 CR4: 0000000000772ef0
[    4.729941] PKRU: 55555554
[    4.729964] note: kworker/u16:1[68] exited with irqs disabled