BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 75ba5067 P4D 75ba5067 PUD 1df58067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 2380 Comm: kworker/u4:5 Not tainted 5.17.0-rc7-syzkaller-02443-gd96657dc9238 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc900001d0a60 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88801d82a010 RCX: 0000000000000100
RDX: 1ffff11003b05403 RSI: ffff88806a645dc0 RDI: ffff88805121d400
RBP: ffff88805121d400 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff87bb8a27 R11: 0000000000000000 R12: ffff88806a645dc0
R13: 0000000000000000 R14: ffff88805121db58 R15: ffff888077a4e12c
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000007d10d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __tcp_transmit_skb+0x1098/0x38b0 net/ipv4/tcp_output.c:1371
 tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline]
 tcp_xmit_probe_skb+0x28c/0x320 net/ipv4/tcp_output.c:4006
 tcp_write_wakeup+0x1bd/0x610 net/ipv4/tcp_output.c:4059
 tcp_send_probe0+0x44/0x560 net/ipv4/tcp_output.c:4074
 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline]
 tcp_write_timer_handler+0x9ed/0xbc0 net/ipv4/tcp_timer.c:626
 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
 expire_timers kernel/time/timer.c:1466 [inline]
 __run_timers.part.0+0x67c/0xa30 kernel/time/timer.c:1734
 __run_timers kernel/time/timer.c:1715 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__local_bh_enable_ip+0xa8/0x120 kernel/softirq.c:390
Code: 1d 9d 28 bb 7e 65 8b 05 96 28 bb 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 95 7a 09 00 e8 40 b7 37 00 fb 65 8b 05 78 28 bb 7e <85> c0 74 58 5b 5d c3 65 8b 05 c6 2f bb 7e 85 c0 75 a2 0f 0b eb 9e
RSP: 0018:ffffc9000b047bd8 EFLAGS: 00000202
RAX: 0000000080000000 RBX: 00000000fffffe00 RCX: 1ffffffff1fc0cfe
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff87c03de1 R08: 0000000000000001 R09: ffffffff8fe0194f
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000002 R14: 0000000000000000 R15: ffff888017a06f08
 spin_unlock_bh include/linux/spinlock.h:394 [inline]
 tcp_metrics_flush_all+0x271/0x350 net/ipv4/tcp_metrics.c:898
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:167
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594
 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
 worker_thread+0x657/0x1110 kernel/workqueue.c:2454
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc900001d0a60 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88801d82a010 RCX: 0000000000000100
RDX: 1ffff11003b05403 RSI: ffff88806a645dc0 RDI: ffff88805121d400
RBP: ffff88805121d400 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff87bb8a27 R11: 0000000000000000 R12: ffff88806a645dc0
R13: 0000000000000000 R14: ffff88805121db58 R15: ffff888077a4e12c
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000007d10d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	1d 9d 28 bb 7e       	sbb    $0x7ebb289d,%eax
   5:	65 8b 05 96 28 bb 7e 	mov    %gs:0x7ebb2896(%rip),%eax        # 0x7ebb28a2
   c:	a9 00 ff ff 00       	test   $0xffff00,%eax
  11:	74 45                	je     0x58
  13:	bf 01 00 00 00       	mov    $0x1,%edi
  18:	e8 95 7a 09 00       	callq  0x97ab2
  1d:	e8 40 b7 37 00       	callq  0x37b762
  22:	fb                   	sti
  23:	65 8b 05 78 28 bb 7e 	mov    %gs:0x7ebb2878(%rip),%eax        # 0x7ebb28a2
* 2a:	85 c0                	test   %eax,%eax <-- trapping instruction
  2c:	74 58                	je     0x86
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	c3                   	retq
  31:	65 8b 05 c6 2f bb 7e 	mov    %gs:0x7ebb2fc6(%rip),%eax        # 0x7ebb2ffe
  38:	85 c0                	test   %eax,%eax
  3a:	75 a2                	jne    0xffffffde
  3c:	0f 0b                	ud2
  3e:	eb 9e                	jmp    0xffffffde