------------[ cut here ]------------
WARNING: CPU: 0 PID: 31878 at kernel/locking/mutex.c:873 __mutex_trylock_slowpath kernel/locking/mutex.c:873 [inline]
WARNING: CPU: 0 PID: 31878 at kernel/locking/mutex.c:873 mutex_trylock+0x2f9/0x3e0 kernel/locking/mutex.c:908
DEBUG_LOCKS_WARN_ON(in_interrupt())[  560.308934] Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 31878 Comm: syz-executor3 Not tainted 4.9.106-g8b94b87 #46
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db2077f8 ffffffff81eb4209 ffffffff83c48b40 00000000ffffffff
 0000000000000000 0000000000000000 0000000000000369 ffff8801db2078b8
 ffffffff81421de5 0000000041b58ab3 ffffffff843b9990 ffffffff81421c26
Call Trace:
 <IRQ> [  560.362024]  [<ffffffff81eb4209>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  560.362024]  [<ffffffff81eb4209>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81421de5>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff814220d1>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff81136662>] warn_slowpath_fmt+0xc2/0x100 kernel/panic.c:565
 [<ffffffff839eec09>] __mutex_trylock_slowpath kernel/locking/mutex.c:873 [inline]
 [<ffffffff839eec09>] mutex_trylock+0x2f9/0x3e0 kernel/locking/mutex.c:908
 [<ffffffff81282f59>] exp_funnel_lock kernel/rcu/tree_exp.h:256 [inline]
 [<ffffffff81282f59>] _synchronize_rcu_expedited+0x339/0x840 kernel/rcu/tree_exp.h:569
 [<ffffffff812844b3>] synchronize_rcu_expedited kernel/rcu/tree_exp.h:687 [inline]
 [<ffffffff812844b3>] synchronize_rcu.part.62+0xd3/0x110 kernel/rcu/tree_plugin.h:682
 [<ffffffff81284517>] synchronize_rcu+0x27/0x90 kernel/rcu/tree_plugin.h:685
 [<ffffffff836bccaa>] __l2tp_session_unhash+0x38a/0x520 net/l2tp/l2tp_core.c:1796
 [<ffffffff836bd037>] l2tp_tunnel_closeall+0x1f7/0x350 net/l2tp/l2tp_core.c:1364
 [<ffffffff836bd8f2>] l2tp_tunnel_destruct+0x2f2/0x590 net/l2tp/l2tp_core.c:1324
 [<ffffffff83021095>] __sk_destruct+0x55/0x590 net/core/sock.c:1428
 [<ffffffff81287bde>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff81287bde>] rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 [<ffffffff81287bde>] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 [<ffffffff81287bde>] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 [<ffffffff81287bde>] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037
 [<ffffffff83a006fb>] __do_softirq+0x20b/0x937 kernel/softirq.c:284
 [<ffffffff8114b227>] invoke_softirq kernel/softirq.c:364 [inline]
 [<ffffffff8114b227>] irq_exit+0x147/0x190 kernel/softirq.c:405
 [<ffffffff839ff2e1>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff839ff2e1>] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff839fb470>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [  560.636578]  [<ffffffff81ee2069>] ? clear_page_c_e+0x9/0x10 arch/x86/lib/clear_page_64.S:54
 [<ffffffff81546717>] __do_huge_pmd_anonymous_page mm/huge_memory.c:559 [inline]
 [<ffffffff81546717>] do_huge_pmd_anonymous_page+0x3c7/0x10f0 mm/huge_memory.c:701
 [<ffffffff814d14de>] create_huge_pmd mm/memory.c:3423 [inline]
 [<ffffffff814d14de>] __handle_mm_fault mm/memory.c:3573 [inline]
 [<ffffffff814d14de>] handle_mm_fault+0x1a9e/0x28e0 mm/memory.c:3634
 [<ffffffff810db9bf>] __do_page_fault+0x5af/0xd50 arch/x86/mm/fault.c:1407
 [<ffffffff810dc187>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1470
 [<ffffffff839fac88>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:951
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..