rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=612/1/0x4000000000000002 softirq=13373/13378 fqs=7 
	(t=10500 jiffies g=6609 q=690)
rcu: rcu_preempt kthread starved for 10483 jiffies! g6609 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    28984    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 8236 Comm: udevd Not tainted 5.5.0-rc5-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:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:check_kcov_mode kernel/kcov.c:153 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x14/0x50 kernel/kcov.c:187
Code: 00 00 00 48 8b 3d f4 f4 ed 07 48 89 de e8 84 f4 3b 00 5b 5d c3 cc 48 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 38 5f 8b 7e <f7> c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 83 fa 02 75 21 48 8b 91
RSP: 0018:ffffc900060ff9f0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81489244 RBX: ffffea0002550280 RCX: ffff88808edd84c0
RDX: 0000000000000001 RSI: 00000000fffffffc RDI: ffffea0002550280
RBP: ffffc900060ffa30 R08: dffffc0000000000 R09: fffffbfff124248a
R10: fffffbfff124248a R11: 0000000000000000 R12: ffff888095716c20
R13: dffffc0000000000 R14: 1ffff11012ae2d84 R15: ffff8880a35353f8
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338
 retint_kernel+0x1b/0x2b
RIP: 0010:vm_area_alloc+0x0/0xf0 kernel/fork.c:348
Code: 03 38 c1 0f 8c 08 ff ff ff 48 c7 c7 48 b3 64 89 e8 75 4f 6b 00 e9 f7 fe ff ff 55 48 89 e5 e8 37 e7 2e 00 5d c3 0f 1f 44 00 00 <55> 48 89 e5 41 57 41 56 41 54 53 49 89 ff e8 1d e7 2e 00 48 8b 3d
RSP: 0018:ffffc900060ffc40 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02
RAX: 0000000000000000 RBX: ffff88809ff2a4c0 RCX: ffff88808edd84c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88809ff2a4c0
RBP: ffffc900060ffd28 R08: ffffffff81a60d88 R09: 0000000000000000
R10: fffffbfff12c9766 R11: 0000000000000000 R12: ffff8880a7ef9040
R13: ffff8880a7ef9060 R14: 0000000000000001 R15: 0000000000000001
 do_mmap+0xabb/0x1120 mm/mmap.c:1549
 do_mmap_pgoff include/linux/mm.h:2338 [inline]
 vm_mmap_pgoff+0x13d/0x1d0 mm/util.c:506
 ksys_mmap_pgoff+0x104/0x560 mm/mmap.c:1601
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
 __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:91
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f102142bd0a
Code: b8 ff ff ff ff e9 fa fe ff ff 48 63 fb b8 03 00 00 00 0f 05 b8 ff ff ff ff e9 e6 fe ff ff 90 90 49 89 ca b8 09 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d fe c0 2a 00 31 d2 48 29 c2 64
RSP: 002b:00007ffc743f4158 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000002246430 RCX: 00007f102142bd0a
RDX: 0000000000000003 RSI: 0000000000001000 RDI: 0000000000000000
RBP: 0000000000001000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000420724
R13: 0000000000000002 R14: 0000000000420724 R15: 0000000000420724