------------[ cut here ]------------
WARNING: CPU: 1 PID: 5939 at net/ipv6/xfrm6_tunnel.c:341 xfrm6_tunnel_net_exit+0x7e/0x100 net/ipv6/xfrm6_tunnel.c:341
Modules linked in:
CPU: 1 UID: 0 PID: 5939 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:xfrm6_tunnel_net_exit+0x7e/0x100 net/ipv6/xfrm6_tunnel.c:341
Code: a8 da de f7 4b 83 3c 2c 00 75 19 e8 ac 5c 7b f7 49 81 fd f8 07 00 00 74 1d e8 9e 5c 7b f7 49 83 c5 08 eb c9 e8 93 5c 7b f7 90 <0f> 0b 90 49 81 fd f8 07 00 00 75 e3 48 81 c3 00 08 00 00 45 31 f6
RSP: 0018:ffffc900030af8b0 EFLAGS: 00010293
RAX: ffffffff8a44646d RBX: ffff888107a34000 RCX: ffff888020409cc0
RDX: 0000000000000000 RSI: ffffffff8d9ba160 RDI: ffff888107a34000
RBP: ffffc900030af9b0 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffff888107a34000
R13: 0000000000000000 R14: ffff888118440000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e07718580 CR3: 0000000111734000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 ops_exit_list net/core/net_namespace.c:198 [inline]
 ops_undo_list+0x49a/0x990 net/core/net_namespace.c:251
 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
