rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=d92/1/0x4000000000000002 softirq=13060/13060 fqs=132 
	(t=10500 jiffies g=6773 q=234)
rcu: rcu_preempt kthread starved for 10231 jiffies! g6773 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29032    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 1
CPU: 1 PID: 8368 Comm: syz-executor.0 Not tainted 5.4.0-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:1514 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638
 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:__sanitizer_cov_trace_pc+0x48/0x50 kernel/kcov.c:112
Code: 80 13 00 00 83 fa 02 75 21 48 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 8b 89 84 13 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 3a <c3> 0f 1f 80 00 00 00 00 4c 8b 04 24 65 48 8b 04 25 c0 1d 02 00 65
RSP: 0018:ffffc900022d7d08 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81487433 RBX: 0000000000000000 RCX: ffff8880a37c4140
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea00025b6a40
RBP: ffffc900022d7d30 R08: 000000000003a768 R09: ffffed10151462bf
R10: ffffed10151462bf R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff8880a8a315e8
 free_thread_stack+0x168/0x590 kernel/fork.c:280
 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
 schedule+0x181/0x210 kernel/sched/core.c:4155
 exit_to_usermode_loop arch/x86/entry/common.c:150 [inline]
 prepare_exit_to_usermode+0x2d4/0x5b0 arch/x86/entry/common.c:195
 ret_from_intr+0x26/0x36
RIP: 0033:0x40f656
Code: f0 48 31 f7 c1 e8 10 83 f6 3d 31 c6 44 8d 4f 04 41 89 f8 8d 1c f6 89 d8 c1 e8 04 31 c3 69 c3 2d eb d4 27 89 c3 c1 eb 0f 31 c3 <89> f8 89 c6 81 e6 ff 1f 00 00 8b 14 b5 00 00 73 00 41 39 d0 74 23
RSP: 002b:00007ffd1b502a30 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: 00000000e75fbe31 RBX: 00000000e75e708e RCX: 0000001b2e620000
RDX: 00000000a6359deb RSI: 00000000817cb418 RDI: ffffffff7d478479
RBP: 0000000000000358 R08: 000000007d478479 R09: 000000007d47847d
R10: 00007ffd1b502bd0 R11: 0000000000000246 R12: 000000000075bfa8
R13: 0000000080000000 R14: 00007f0ceb950008 R15: 00000000000062d5