syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10500 ticks this GP) idle=5ae/1/0x4000000000000002 softirq=119477/119477 fqs=5250 
rcu: 	 (t=10502 jiffies g=159189 q=1182)
NMI backtrace for cpu 0
CPU: 0 PID: 8786 Comm: kworker/0:5 Not tainted 5.1.0-rc4+ #170
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient gc_worker
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree.c:1223
 print_cpu_stall kernel/rcu/tree.c:1360 [inline]
 check_cpu_stall kernel/rcu/tree.c:1434 [inline]
 rcu_pending kernel/rcu/tree.c:3103 [inline]
 rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2544
 update_process_times+0x32/0x80 kernel/time/timer.c:1635
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:check_memory_region+0x14/0x190 mm/kasan/generic.c:190
Code: 89 e5 e8 9f 58 66 05 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 48 85 f6 0f 84 21 01 00 00 48 b8 ff ff ff ff ff 7f ff ff 55 <0f> b6 d2 48 39 c7 48 89 e5 41 55 41 54 53 0f 86 f6 00 00 00 4c 8d
RSP: 0018:ffff88808a60f928 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: ffff7fffffffffff RBX: ffffe8ffffc780a0 RCX: ffffffff81583787
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffe8ffffc780a0
RBP: ffff88808a60f938 R08: 1ffffd1ffff8f014 R09: fffff91ffff8f015
R10: fffff91ffff8f014 R11: ffffe8ffffc780a3 R12: 0000000000000001
R13: 0000000000000003 R14: fffff91ffff8f014 R15: 0000000000000007
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 virt_spin_lock arch/x86/include/asm/qspinlock.h:83 [inline]
 native_queued_spin_lock_slowpath+0xb7/0x9f0 kernel/locking/qspinlock.c:334
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:654 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:50 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:90 [inline]
 do_raw_spin_lock+0x20e/0x2e0 kernel/locking/spinlock_debug.c:113
 __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_lock+0x37/0x40 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:329 [inline]
 nf_ct_add_to_dying_list+0xdb/0x210 net/netfilter/nf_conntrack_core.c:472
 nf_ct_delete_from_lists+0x3c1/0x530 net/netfilter/nf_conntrack_core.c:619
 nf_ct_delete net/netfilter/nf_conntrack_core.c:646 [inline]
 nf_ct_delete+0x1d0/0x4c0 net/netfilter/nf_conntrack_core.c:624
 nf_ct_kill include/net/netfilter/nf_conntrack.h:219 [inline]
 nf_ct_gc_expired net/netfilter/nf_conntrack_core.c:688 [inline]
 nf_ct_gc_expired+0x2da/0x350 net/netfilter/nf_conntrack_core.c:682
 gc_worker+0xb2a/0xea0 net/netfilter/nf_conntrack_core.c:1234
 process_one_work+0x98e/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352