rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=412/1/0x4000000000000002 softirq=11250/11254 fqs=39 
	(t=10500 jiffies g=6425 q=81)
rcu: rcu_preempt kthread starved for 10421 jiffies! g6425 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: 8323 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: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:free_thread_stack+0x133/0x590 kernel/fork.c:280
Code: 00 ea ff ff 48 01 c7 be 03 00 00 00 e8 f6 9e 60 00 e9 5d 04 00 00 e8 dc 2a 2e 00 48 89 df 31 f6 e8 a2 a1 6e 00 43 80 3c 2e 00 <74> 08 4c 89 e7 e8 43 a0 69 00 49 8b 1c 24 48 83 c3 08 48 89 d8 48
RSP: 0018:ffffc90002307598 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: ffffea000298de80 RCX: 0000000000000000
RDX: ffffc90001fa9000 RSI: 0000000000000000 RDI: ffffea000298de80
RBP: ffffc900023075d0 R08: 000000000003a728 R09: ffffed10150936a7
R10: ffffed10150936a7 R11: 0000000000000000 R12: ffff888093fa4620
R13: dffffc0000000000 R14: 1ffff110127f48c4 R15: ffff8880a849b528
 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:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:98
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 3c cd 07 48 89 de e8 d4 01 3b 00 5b 5d c3 cc <48> 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 38 84 8b 7e f7 c2
RSP: 0018:ffffc900023077e8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: ffff8880a55ac040 RBX: 0000000000000001 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002307848 R08: ffffffff8354fe7c R09: ffffed1013450e37
R10: ffffed1013450e37 R11: 0000000000000000 R12: 0000000000000001
R13: 00000000000008e0 R14: ffff88809a287180 R15: dffffc0000000000
 tomoyo_path_permission security/tomoyo/file.c:586 [inline]
 tomoyo_check_open_permission+0x3ce/0x9d0 security/tomoyo/file.c:777
 tomoyo_file_open+0x141/0x190 security/tomoyo/tomoyo.c:319
 security_file_open+0x65/0x2f0 security/security.c:1497
 do_dentry_open+0x351/0x10c0 fs/open.c:784
 vfs_open+0x73/0x80 fs/open.c:914
 do_last fs/namei.c:3412 [inline]
 path_openat+0x1397/0x44a0 fs/namei.c:3529
 do_filp_open+0x192/0x3d0 fs/namei.c:3559
 do_sys_open+0x29f/0x560 fs/open.c:1097
 __do_sys_open fs/open.c:1115 [inline]
 __se_sys_open fs/open.c:1110 [inline]
 __x64_sys_open+0x87/0x90 fs/open.c:1110
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x414411
Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f6d4858f7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000414411
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f6d4858f850
RBP: 000000000075bf20 R08: 000000000000000f R09: 0000000000000000
R10: 00007f6d485909d0 R11: 0000000000000293 R12: 00007f6d485906d4
R13: 00000000004caefe R14: 00000000004e4470 R15: 00000000ffffffff