===============================
[ INFO: suspicious RCU usage. ]
4.9.119-g9dc978d #27 Not tainted
-------------------------------
kernel/rcu/tree_plugin.h:678 Illegal synchronize_rcu() in RCU read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 0
3 locks held by blkid/19647:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff814e9b5d>] do_mprotect_pkey+0x18d/0x890 mm/mprotect.c:388
 #1:  (rcu_read_lock){......}, at: [<ffffffff81cf7be0>] INIT_LIST_HEAD include/linux/list.h:28 [inline]
 #1:  (rcu_read_lock){......}, at: [<ffffffff81cf7be0>] avc_compute_av+0xb0/0x610 security/selinux/avc.c:975
 #2:  (rcu_callback){......}, at: [<ffffffff812878ae>] __rcu_reclaim kernel/rcu/rcu.h:108 [inline]
 #2:  (rcu_callback){......}, at: [<ffffffff812878ae>] rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 #2:  (rcu_callback){......}, at: [<ffffffff812878ae>] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 #2:  (rcu_callback){......}, at: [<ffffffff812878ae>] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 #2:  (rcu_callback){......}, at: [<ffffffff812878ae>] rcu_process_callbacks+0x98e/0x12b0 kernel/rcu/tree.c:3037

stack backtrace:
CPU: 0 PID: 19647 Comm: blkid Not tainted 4.9.119-g9dc978d #27
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db207d60 ffffffff81eb4be9 ffff8801bace0000 0000000000000000
 0000000000000002 ffffffff83c6df20 ffff8801cadde158 ffff8801db207d90
 ffffffff81426330 ffff8801cadde000 ffff8801cb46dd48 ffff8801cb46d548
Call Trace:
 <IRQ> [  451.952769]  [<ffffffff81eb4be9>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  451.952769]  [<ffffffff81eb4be9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81426330>] lockdep_rcu_suspicious.cold.48+0x110/0x141 kernel/locking/lockdep.c:4455
 [<ffffffff81284148>] synchronize_rcu+0x68/0x90 kernel/rcu/tree_plugin.h:675
 [<ffffffff836bfe3a>] __l2tp_session_unhash+0x38a/0x520 net/l2tp/l2tp_core.c:1796
 [<ffffffff836c01c7>] l2tp_tunnel_closeall+0x1f7/0x350 net/l2tp/l2tp_core.c:1364
 [<ffffffff836c0a82>] l2tp_tunnel_destruct+0x2f2/0x590 net/l2tp/l2tp_core.c:1324
 [<ffffffff830230f5>] __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
 [<ffffffff83a038bb>] __do_softirq+0x20b/0x937 kernel/softirq.c:284
 [<ffffffff8114b277>] invoke_softirq kernel/softirq.c:364 [inline]
 [<ffffffff8114b277>] irq_exit+0x147/0x190 kernel/softirq.c:405
 [<ffffffff83a024a1>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff83a024a1>] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff839fe630>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [  452.066523]  [<ffffffff839fc3cf>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
 <EOI> [  452.066523]  [<ffffffff839fc3cf>] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline]
 <EOI> [  452.066523]  [<ffffffff839fc3cf>] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff81cf7059>] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline]
 [<ffffffff81cf7059>] avc_reclaim_node security/selinux/avc.c:543 [inline]
 [<ffffffff81cf7059>] avc_alloc_node+0x289/0x3d0 security/selinux/avc.c:561
 [<ffffffff81cf7ca8>] avc_insert security/selinux/avc.c:672 [inline]
 [<ffffffff81cf7ca8>] avc_compute_av+0x178/0x610 security/selinux/avc.c:978
 [<ffffffff81cf9d84>] avc_has_perm_noaudit security/selinux/avc.c:1114 [inline]
 [<ffffffff81cf9d84>] avc_has_perm+0x364/0x4f0 security/selinux/avc.c:1148
 [<ffffffff81d040aa>] inode_has_perm.isra.32+0x10a/0x160 security/selinux/hooks.c:1704
 [<ffffffff81d04353>] file_has_perm+0x253/0x330 security/selinux/hooks.c:1794
 [<ffffffff81d04a43>] file_map_prot_check+0x1e3/0x310 security/selinux/hooks.c:3519
 [<ffffffff81d152bf>] selinux_file_mprotect+0xef/0x5d0 security/selinux/hooks.c:3583
 [<ffffffff81cf1a03>] security_file_mprotect+0x83/0xc0 security/security.c:852
 [<ffffffff814e9e14>] do_mprotect_pkey+0x444/0x890 mm/mprotect.c:453
 [<ffffffff814ea28a>] SYSC_mprotect mm/mprotect.c:485 [inline]
 [<ffffffff814ea28a>] SyS_mprotect+0x2a/0x40 mm/mprotect.c:482
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fccd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
BUG: sleeping function called from invalid context at kernel/rcu/tree_exp.h:281
in_atomic(): 1, irqs_disabled(): 0, pid: 19647, name: blkid
INFO: lockdep is turned off.
Preemption disabled at:[  452.241694] [<ffffffff81cf6f03>] avc_reclaim_node security/selinux/avc.c:528 [inline]
Preemption disabled at:[  452.241694] [<ffffffff81cf6f03>] avc_alloc_node+0x133/0x3d0 security/selinux/avc.c:561
CPU: 0 PID: 19647 Comm: blkid Not tainted 4.9.119-g9dc978d #27
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801db2079b0 ffffffff81eb4be9 ffffffff81cf6f03 0000000000000000
 0000000000000102 ffff8801bace0000 ffff8801bace0000 ffff8801db2079e8
 ffffffff81424630 ffff8801bace0000 ffffffff83c6d460 0000000000000119
Call Trace:
 <IRQ> [  452.292672]  [<ffffffff81eb4be9>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  452.292672]  [<ffffffff81eb4be9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81424630>] ___might_sleep.cold.123+0x1bc/0x1f5 kernel/sched/core.c:7988
 [<ffffffff811bb6c5>] __might_sleep+0x95/0x1a0 kernel/sched/core.c:7945
 [<ffffffff81282e10>] exp_funnel_lock kernel/rcu/tree_exp.h:279 [inline]
 [<ffffffff81282e10>] _synchronize_rcu_expedited+0x600/0x840 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
 [<ffffffff836bfe3a>] __l2tp_session_unhash+0x38a/0x520 net/l2tp/l2tp_core.c:1796
 [<ffffffff836c01c7>] l2tp_tunnel_closeall+0x1f7/0x350 net/l2tp/l2tp_core.c:1364
 [<ffffffff836c0a82>] l2tp_tunnel_destruct+0x2f2/0x590 net/l2tp/l2tp_core.c:1324
 [<ffffffff830230f5>] __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
 [<ffffffff83a038bb>] __do_softirq+0x20b/0x937 kernel/softirq.c:284
 [<ffffffff8114b277>] invoke_softirq kernel/softirq.c:364 [inline]
 [<ffffffff8114b277>] irq_exit+0x147/0x190 kernel/softirq.c:405
 [<ffffffff83a024a1>] exiting_irq arch/x86/include/asm/apic.h:659 [inline]
 [<ffffffff83a024a1>] smp_apic_timer_interrupt+0x81/0xa0 arch/x86/kernel/apic/apic.c:960
 [<ffffffff839fe630>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [  452.517321]  [<ffffffff839fc3cf>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
 <EOI> [  452.517321]  [<ffffffff839fc3cf>] ? __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:162 [inline]
 <EOI> [  452.517321]  [<ffffffff839fc3cf>] ? _raw_spin_unlock_irqrestore+0x5f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff81cf7059>] spin_unlock_irqrestore include/linux/spinlock.h:362 [inline]
 [<ffffffff81cf7059>] avc_reclaim_node security/selinux/avc.c:543 [inline]
 [<ffffffff81cf7059>] avc_alloc_node+0x289/0x3d0 security/selinux/avc.c:561
 [<ffffffff81cf7ca8>] avc_insert security/selinux/avc.c:672 [inline]
 [<ffffffff81cf7ca8>] avc_compute_av+0x178/0x610 security/selinux/avc.c:978
 [<ffffffff81cf9d84>] avc_has_perm_noaudit security/selinux/avc.c:1114 [inline]
 [<ffffffff81cf9d84>] avc_has_perm+0x364/0x4f0 security/selinux/avc.c:1148
 [<ffffffff81d040aa>] inode_has_perm.isra.32+0x10a/0x160 security/selinux/hooks.c:1704
 [<ffffffff81d04353>] file_has_perm+0x253/0x330 security/selinux/hooks.c:1794
 [<ffffffff81d04a43>] file_map_prot_check+0x1e3/0x310 security/selinux/hooks.c:3519
 [<ffffffff81d152bf>] selinux_file_mprotect+0xef/0x5d0 security/selinux/hooks.c:3583
 [<ffffffff81cf1a03>] security_file_mprotect+0x83/0xc0 security/security.c:852
 [<ffffffff814e9e14>] do_mprotect_pkey+0x444/0x890 mm/mprotect.c:453
 [<ffffffff814ea28a>] SYSC_mprotect mm/mprotect.c:485 [inline]
 [<ffffffff814ea28a>] SyS_mprotect+0x2a/0x40 mm/mprotect.c:482
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839fccd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
BUG: scheduling while atomic: blkid/19647/0x00000102
INFO: lockdep is turned off.
Modules linked in:
Preemption disabled at:[  452.686632] [<ffffffff81cf6f03>] avc_reclaim_node security/selinux/avc.c:528 [inline]
Preemption disabled at:[  452.686632] [<ffffffff81cf6f03>] avc_alloc_node+0x133/0x3d0 security/selinux/avc.c:561