Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 2 UID: 0 PID: 8709 Comm: kworker/u32:17 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:xfrm_state_fini+0x289/0x310 net/xfrm/xfrm_state.c:3306
Code: c4 f7 90 0f 0b 90 e9 e7 fe ff ff e8 31 36 c4 f7 90 0f 0b 90 e9 39 ff ff ff e8 23 36 c4 f7 90 0f 0b 90 eb 8a e8 18 36 c4 f7 90 <0f> 0b 90 e9 d5 fd ff ff e8 1a cd 2b f8 e9 f8 fd ff ff e8 40 cd 2b
RSP: 0018:ffffc90006c77a90 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88802af60000 RCX: fffff52000d8ef23
RDX: ffff888021070000 RSI: ffffffff89f83738 RDI: ffff888021070484
RBP: ffff88802af614c0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffffc90006c77bd8
R13: dffffc0000000000 R14: fffffbfff2055c80 R15: ffffffff902ae3e0
 xfrm_net_exit+0x2d/0x70 net/xfrm/xfrm_policy.c:4354
 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..