Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 3 UID: 0 PID: 1146 Comm: kworker/u32:8 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x3d/0x1f0 lib/dump_stack.c:120
 vpanic+0x640/0x6f0 kernel/panic.c:489
 panic+0xca/0xd0 kernel/panic.c:626
 check_panic_on_warn kernel/panic.c:376 [inline]
 check_panic_on_warn+0xab/0xb0 kernel/panic.c:371
 __warn+0xf6/0x3c0 kernel/panic.c:897
 __report_bug lib/bug.c:195 [inline]
 report_bug+0x3c3/0x580 lib/bug.c:215
 handle_bug+0x184/0x210 arch/x86/kernel/traps.c:338
 exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:392
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:616
RIP: 0010:xfrm6_tunnel_net_exit+0x9f/0x160 net/ipv6/xfrm6_tunnel.c:341
Code: 00 00 00 49 8d 3c dc 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 bd 00 00 00 89 e8 49 8b 04 c4 48 85 c0 74 ab e8 92 a7 98 f7 90 <0f> 0b 90 eb a0 4d 8d ac 24 00 08 00 00 31 db 49 be 00 00 00 00 00
RSP: 0018:ffffc90006c6fa90 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: fffff52000d8df23
RDX: ffff888027130000 RSI: ffffffff8a2410ce RDI: ffff888059384000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90836ed7 R11: 0000000000000001 R12: ffff888059384000
R13: dffffc0000000000 R14: fffffbfff2060c68 R15: ffffffff90306320
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
 cleanup_net+0x41b/0x8b0 net/core/net_namespace.c:695
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..