l2tp_core: sess 4/0: closing session
------------[ cut here ]------------
WARNING: CPU: 1 PID: 17813 at kernel/locking/mutex.c:873 __mutex_trylock_slowpath kernel/locking/mutex.c:873 [inline]
WARNING: CPU: 1 PID: 17813 at kernel/locking/mutex.c:873 mutex_trylock+0x2f9/0x3e0 kernel/locking/mutex.c:908
DEBUG_LOCKS_WARN_ON(in_interrupt())[  208.974508] Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 17813 Comm: syz-executor1 Not tainted 4.9.113-g47bbcd6 #62
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db3077f8 ffffffff81eb32a9 ffffffff83c48980 00000000ffffffff
 0000000000000000 0000000000000001 0000000000000369 ffff8801db3078b8
 ffffffff81421a55 0000000041b58ab3 ffffffff843bb788 ffffffff81421896
Call Trace:
 <IRQ> [  209.027761]  [<ffffffff81eb32a9>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  209.027761]  [<ffffffff81eb32a9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81421a55>] panic+0x1bf/0x3bc kernel/panic.c:179
 [<ffffffff81421d41>] __warn.cold.9+0xc1/0x17f kernel/panic.c:542
 [<ffffffff811366e2>] warn_slowpath_fmt+0xc2/0x100 kernel/panic.c:565
 [<ffffffff839ef099>] __mutex_trylock_slowpath kernel/locking/mutex.c:873 [inline]
 [<ffffffff839ef099>] mutex_trylock+0x2f9/0x3e0 kernel/locking/mutex.c:908
 [<ffffffff81282b49>] exp_funnel_lock kernel/rcu/tree_exp.h:256 [inline]
 [<ffffffff81282b49>] _synchronize_rcu_expedited+0x339/0x840 kernel/rcu/tree_exp.h:569
 [<ffffffff812840a3>] synchronize_rcu_expedited kernel/rcu/tree_exp.h:687 [inline]
 [<ffffffff812840a3>] synchronize_rcu.part.62+0xd3/0x110 kernel/rcu/tree_plugin.h:682
 [<ffffffff81284107>] synchronize_rcu+0x27/0x90 kernel/rcu/tree_plugin.h:685
 [<ffffffff836bd17a>] __l2tp_session_unhash+0x38a/0x520 net/l2tp/l2tp_core.c:1796
 [<ffffffff836bd507>] l2tp_tunnel_closeall+0x1f7/0x350 net/l2tp/l2tp_core.c:1364
 [<ffffffff836bddc2>] l2tp_tunnel_destruct+0x2f2/0x590 net/l2tp/l2tp_core.c:1324
 [<ffffffff83021095>] __sk_destruct+0x55/0x590 net/core/sock.c:1428
 [<ffffffff812877ce>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff812877ce>] rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 [<ffffffff812877ce>] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 [<ffffffff812877ce>] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 [<ffffffff812877ce>] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037
 [<ffffffff83a00b7b>] __do_softirq+0x20b/0x937 kernel/softirq.c:284
 [<ffffffff8114b287>] invoke_softirq kernel/softirq.c:364 [inline]
 [<ffffffff8114b287>] irq_exit+0x147/0x190 kernel/softirq.c:405
 [<ffffffff839ff761>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff839ff761>] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff839fb8f0>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [  209.289667]  [<ffffffff839f969f>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
 <EOI> [  209.289667]  [<ffffffff839f969f>] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline]
 <EOI> [  209.289667]  [<ffffffff839f969f>] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff81f1defc>] __debug_check_no_obj_freed lib/debugobjects.c:733 [inline]
 [<ffffffff81f1defc>] debug_check_no_obj_freed+0x2ec/0x930 lib/debugobjects.c:749
 [<ffffffff8144a49d>] free_pages_prepare mm/page_alloc.c:1073 [inline]
 [<ffffffff8144a49d>] __free_pages_ok+0x1dd/0x1610 mm/page_alloc.c:1275
 [<ffffffff8144b92e>] free_compound_page+0x5e/0x70 mm/page_alloc.c:606
 [<ffffffff81551ce9>] free_transhuge_page+0x99/0xc0 mm/huge_memory.c:2229
 [<ffffffff81463d30>] __put_compound_page+0x80/0xc0 mm/swap.c:94
 [<ffffffff81465924>] release_pages+0x2f4/0x970 mm/swap.c:763
 [<ffffffff81508b47>] free_pages_and_swap_cache+0x117/0x160 mm/swap_state.c:273
 [<ffffffff814c00d4>] tlb_flush_mmu_free+0xb4/0x150 mm/memory.c:259
 [<ffffffff814c850d>] zap_pte_range mm/memory.c:1216 [inline]
 [<ffffffff814c850d>] zap_pmd_range mm/memory.c:1258 [inline]
 [<ffffffff814c850d>] zap_pud_range mm/memory.c:1279 [inline]
 [<ffffffff814c850d>] unmap_page_range+0x104d/0x1730 mm/memory.c:1300
 [<ffffffff814c8cf1>] unmap_single_vma+0x101/0x260 mm/memory.c:1345
 [<ffffffff814c9632>] unmap_vmas+0x102/0x1d0 mm/memory.c:1375
 [<ffffffff814e1d94>] exit_mmap+0x214/0x3f0 mm/mmap.c:3020
 [<ffffffff8112bff3>] __mmput kernel/fork.c:881 [inline]
 [<ffffffff8112bff3>] mmput+0xf3/0x2d0 kernel/fork.c:903
 [<ffffffff81140de6>] exit_mm kernel/exit.c:514 [inline]
 [<ffffffff81140de6>] do_exit+0x906/0x27b0 kernel/exit.c:820
 [<ffffffff81146fa1>] do_group_exit+0x111/0x340 kernel/exit.c:937
 [<ffffffff81169dff>] get_signal+0x4cf/0x1450 kernel/signal.c:2321
 [<ffffffff81052637>] do_signal+0x87/0x19f0 arch/x86/kernel/signal.c:807
 [<ffffffff81005581>] exit_to_usermode_loop+0xe1/0x120 arch/x86/entry/common.c:157
 [<ffffffff810064d4>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff810064d4>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff810064d4>] do_syscall_64+0x364/0x490 arch/x86/entry/common.c:287
 [<ffffffff839f9f93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..