rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=0d2/1/0x4000000000000002 softirq=11215/11215 fqs=39 
	(t=10501 jiffies g=6601 q=423)
rcu: rcu_preempt kthread starved for 10424 jiffies! g6601 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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 1
CPU: 1 PID: 8351 Comm: rsyslogd 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:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:183
Code: 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 53 48 89 fb e8 13 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
RSP: 0018:ffffc90001be7a50 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff110127e82e1 RBX: ffffea00027cf700 RCX: ffff88808c2065c0
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea00027cf700
RBP: ffffc90001be7a90 R08: 000000000003a728 R09: ffffed101477be81
R10: ffffed101477be81 R11: 0000000000000000 R12: ffff88809fec9ca0
R13: dffffc0000000000 R14: 1ffff11013fd9394 R15: ffff8880a3bdf3f8
 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
 do_syslog+0xdb0/0x1770 kernel/printk/printk.c:1525
 kmsg_read+0x94/0xd0 fs/proc/kmsg.c:40
 proc_reg_read+0x1e2/0x2d0 fs/proc/inode.c:223
 __vfs_read+0xb8/0x730 fs/read_write.c:425
 vfs_read+0x1dd/0x420 fs/read_write.c:461
 ksys_read+0x117/0x220 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x7b/0x90 fs/read_write.c:595
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7ff10c5f41fd
Code: d1 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 5e fa ff ff 48 89 04 24 b8 00 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 a7 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ff109b93e30 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00000000014ad650 RCX: 00007ff10c5f41fd
RDX: 0000000000000fff RSI: 00007ff10b3c85a0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000001498260 R09: 0000000004000001
R10: 0000000000000001 R11: 0000000000000293 R12: 000000000065e420
R13: 00007ff109b949c0 R14: 00007ff10cc39040 R15: 0000000000000003