INFO: rcu_preempt self-detected stall on CPU
	0-...: (10500 ticks this GP) idle=5e6/140000000000001/0 softirq=264068/264068 fqs=0 
INFO: rcu_preempt detected stalls on CPUs/tasks:
	 (t=10502 jiffies g=80067 c=80066 q=132)
	0-...: (10500 ticks this GP) idle=5e6/140000000000001/0 softirq=264068/264068 fqs=0 
rcu_preempt kthread starved for 10502 jiffies! g80067 c80066 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=1
rcu_preempt     I30008     8      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
	
 schedule_timeout+0x4af/0xe90 kernel/time/timer.c:1747
(detected by 1, t=10502 jiffies, g=80067, c=80066, q=132)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2662 Comm: syz-executor.3 Not tainted 4.14.215-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809cff2340 task.stack: ffff8880b3f00000
RIP: 0010:io_serial_in+0x13/0x80 drivers/tty/serial/8250/8250_port.c:449
RSP: 0018:ffff8880ba407930 EFLAGS: 00000006
RAX: ffff88809cff2340 RBX: 0000000000000001 RCX: 0000000000005777
RDX: 0000000000010000 RSI: 0000000000000001 RDI: ffffffff8c8bc451
RBP: ffffffff8c8bc380 R08: ffffffff8b9b5678 R09: 00000000000c4043
R10: ffff88809cff2c68 R11: ffff88809cff2340 R12: ffffffff8be748a0
R13: 0000000000000038 R14: ffffffff8c8bc5a0 R15: dffffc0000000000
FS:  00007fb1a140d700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000119c020 CR3: 0000000075e02000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 serial_port_in include/linux/serial_core.h:261 [inline]
 serial8250_console_write+0x245/0x9d0 drivers/tty/serial/8250/8250_port.c:3258
 call_console_drivers kernel/printk/printk.c:1725 [inline]
 console_unlock+0x99d/0xf20 kernel/printk/printk.c:2400
 vprintk_emit+0x224/0x620 kernel/printk/printk.c:1923
 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401
 printk+0x9e/0xbc kernel/printk/printk.c:1996
 printk_stack_address arch/x86/kernel/dumpstack.c:70 [inline]
 show_trace_log_lvl+0x202/0x280 arch/x86/kernel/dumpstack.c:202
 sched_show_task.cold+0x333/0x39a kernel/sched/core.c:5165
 rcu_check_gp_kthread_starvation+0x28d/0x2d4 kernel/rcu/tree.c:1374
 print_cpu_stall kernel/rcu/tree.c:1540 [inline]
 check_cpu_stall kernel/rcu/tree.c:1610 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0x45c/0xd99 kernel/rcu/tree.c:2792
 update_process_times+0x29/0x60 kernel/time/timer.c:1591
 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x92/0x200 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x30b/0xc80 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:27 [inline]
RIP: 0010:queued_write_lock_slowpath+0xcb/0x1d0 kernel/locking/qrwlock.c:139
RSP: 0018:ffff8880b3f07d38 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000101 RBX: ffffffff89dd2ae8 RCX: 00000000000014c8
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff89dd2ae8
RBP: ffffffff89dd2aec R08: ffffffff8b994100 R09: 000000000004059a
R10: ffff88809cff2bf0 R11: ffff88809cff2340 R12: 0000000000000003
R13: fffffbfff13ba55d R14: 00000000000000ff R15: ffffffff88638380
 queued_write_lock include/asm-generic/qrwlock.h:134 [inline]
 do_raw_write_lock+0xc2/0x1d0 kernel/locking/spinlock_debug.c:203
 bt_sock_link+0x1f/0x120 net/bluetooth/af_bluetooth.c:143
 hci_sock_create+0x15c/0x1d0 net/bluetooth/hci_sock.c:2017
 bt_sock_create+0x13b/0x280 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x303/0x620 net/socket.c:1275
 sock_create net/socket.c:1315 [inline]
 SYSC_socket net/socket.c:1345 [inline]
 SyS_socket+0xd1/0x1b0 net/socket.c:1325
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45e219
RSP: 002b:00007fb1a140cc08 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001f
RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00007ffca5c0fc6f R14: 00007fb1a140d9c0 R15: 000000000119bf8c
Code: b3 1c fe eb c9 e8 ae b5 1c fe eb e6 66 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 89 f3 e8 14 c9 f2 fd 48 8d bd d1 00 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 
rcu_preempt kthread starved for 10502 jiffies! g80067 c80066 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=1
rcu_preempt     I
30008     8      2 0x80000000
Call Trace:
 rcu_gp_kthread+0xc0a/0x1e60 kernel/rcu/tree.c:2255
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 kthread+0x30d/0x420 kernel/kthread.c:232
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
 schedule_timeout+0x4af/0xe90 kernel/time/timer.c:1747
NMI backtrace for cpu 0
CPU: 0 PID: 2662 Comm: syz-executor.3 Not tainted 4.14.215-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 rcu_gp_kthread+0xc0a/0x1e60 kernel/rcu/tree.c:2255
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62
 kthread+0x30d/0x420 kernel/kthread.c:232
 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline]
 rcu_dump_cpu_stacks+0x15f/0x19c kernel/rcu/tree.c:1396
 print_cpu_stall kernel/rcu/tree.c:1542 [inline]
 check_cpu_stall kernel/rcu/tree.c:1610 [inline]
 __rcu_pending kernel/rcu/tree.c:3390 [inline]
 rcu_pending kernel/rcu/tree.c:3452 [inline]
 rcu_check_callbacks.cold+0x464/0xd99 kernel/rcu/tree.c:2792
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
 update_process_times+0x29/0x60 kernel/time/timer.c:1591
 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165
 tick_sched_timer+0x92/0x200 kernel/time/tick-sched.c:1223
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x30b/0xc80 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:27 [inline]
RIP: 0010:queued_write_lock_slowpath+0xcb/0x1d0 kernel/locking/qrwlock.c:139
RSP: 0018:ffff8880b3f07d38 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000101 RBX: ffffffff89dd2ae8 RCX: 00000000000014c8
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff89dd2ae8
RBP: ffffffff89dd2aec R08: ffffffff8b994100 R09: 000000000004059a
R10: ffff88809cff2bf0 R11: ffff88809cff2340 R12: 0000000000000003
R13: fffffbfff13ba55d R14: 00000000000000ff R15: ffffffff88638380
 queued_write_lock include/asm-generic/qrwlock.h:134 [inline]
 do_raw_write_lock+0xc2/0x1d0 kernel/locking/spinlock_debug.c:203
 bt_sock_link+0x1f/0x120 net/bluetooth/af_bluetooth.c:143
 hci_sock_create+0x15c/0x1d0 net/bluetooth/hci_sock.c:2017
 bt_sock_create+0x13b/0x280 net/bluetooth/af_bluetooth.c:130
 __sock_create+0x303/0x620 net/socket.c:1275
 sock_create net/socket.c:1315 [inline]
 SYSC_socket net/socket.c:1345 [inline]
 SyS_socket+0xd1/0x1b0 net/socket.c:1325
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45e219
RSP: 002b:00007fb1a140cc08 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e219
RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001f
RBP: 000000000119bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c
R13: 00007ffca5c0fc6f R14: 00007fb1a140d9c0 R15: 000000000119bf8c