rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=3f6/1/0x4000000000000000 softirq=62546/62547 fqs=1 
	(t=10500 jiffies g=115897 q=209)
rcu: rcu_preempt kthread starved for 10497 jiffies! g115897 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29120    10      2 0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_timeout+0x148/0x250 kernel/time/timer.c:1897
 rcu_gp_fqs_loop kernel/rcu/tree.c:1874 [inline]
 rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2044
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
NMI backtrace for cpu 0
CPU: 0 PID: 5693 Comm: syz-executor.4 Not tainted 5.8.0-rc4-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+0x18f/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:320
 print_cpu_stall kernel/rcu/tree_stall.h:553 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
 rcu_pending kernel/rcu/tree.c:3489 [inline]
 rcu_sched_clock_irq.cold+0x5b3/0xccc kernel/rcu/tree.c:2504
 update_process_times+0x25/0x60 kernel/time/timer.c:1726
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176
 tick_sched_timer+0x108/0x290 kernel/time/tick-sched.c:1320
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline]
 sysvec_apic_timer_interrupt+0x4f/0x120 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline]
RIP: 0010:lock_release+0x481/0x8d0 kernel/locking/lockdep.c:4980
Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 7f 03 00 00 48 83 3d 6b d7 5a 08 00 0f 84 a9 01 00 00 48 8b 3c 24 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c5 48 c7 45 00
RSP: 0018:ffffc90000007c68 EFLAGS: 00000286
RAX: 1ffffffff1369c10 RBX: ffff88802e87a200 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffc90000007d78 RDI: 0000000000000286
RBP: 1ffff92000000f8f R08: 0000000000000001 R09: ffff88802e87aac8
R10: fffffbfff155cb61 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff8163a553 R14: 0000000000000002 R15: ffff88802e87a200
 call_timer_fn+0x227/0x760 kernel/time/timer.c:1407
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers.part.0+0x54c/0xa20 kernel/time/timer.c:1773
 __run_timers kernel/time/timer.c:1745 [inline]
 run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1786
 __do_softirq+0x34c/0xa60 kernel/softirq.c:292
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 do_softirq_own_stack+0x111/0x170 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:387 [inline]
 __irq_exit_rcu kernel/softirq.c:417 [inline]
 irq_exit_rcu+0x229/0x270 kernel/softirq.c:429
 sysvec_apic_timer_interrupt+0x54/0x120 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587
RIP: 0010:arch_local_irq_restore+0x2e/0x50 arch/x86/include/asm/paravirt.h:765
Code: e0 b4 89 53 48 89 fb 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 18 48 83 3d e9 e8 5b 08 00 74 0c 48 89 df 57 9d <0f> 1f 44 00 00 5b c3 0f 0b 48 c7 c7 80 e0 b4 89 e8 2d 16 5a 00 eb
RSP: 0018:ffffc90017287510 EFLAGS: 00000286
RAX: 1ffffffff1369c10 RBX: 0000000000000286 RCX: 1ffff92002e50000
RDX: dffffc0000000000 RSI: ffffffff89bc1160 RDI: 0000000000000286
RBP: ffff88802e87a200 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88802e87aad0 R14: ffff88802e87aad0 R15: 0000000000000286
 lock_is_held_type+0xb0/0xe0 kernel/locking/lockdep.c:4998
 lock_is_held include/linux/lockdep.h:425 [inline]
 schedule_debug kernel/sched/core.c:3983 [inline]
 __schedule+0x1088/0x1eb0 kernel/sched/core.c:4108
 preempt_schedule_irq+0xb0/0x150 kernel/sched/core.c:4436
 idtentry_exit_cond_resched arch/x86/entry/common.c:663 [inline]
 idtentry_exit_cond_rcu+0xc0/0xf0 arch/x86/entry/common.c:710
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587
RIP: 0010:__sanitizer_cov_trace_pc+0x52/0x60 kernel/kcov.c:205
Code: 74 2b 8b 82 e0 13 00 00 83 f8 02 75 20 48 8b 8a e8 13 00 00 8b 92 e4 13 00 00 48 8b 01 48 83 c0 01 48 39 c2 76 07 48 89 34 c1 <48> 89 01 c3 66 2e 0f 1f 84 00 00 00 00 00 41 55 41 54 49 89 fc 55
RSP: 0018:ffffc90017287728 EFLAGS: 00000216
RAX: 0000000000000643 RBX: ffff88809713d082 RCX: ffffc90011d53000
RDX: 0000000000040000 RSI: ffffffff83620b6e RDI: 0000000000000001
RBP: 0000000000000065 R08: 0000000000000d40 R09: ffff88802e87aac8
R10: 000000000000005c R11: 0000000000000000 R12: ffff888040110ff6
R13: 0000000000000009 R14: 0000000000000002 R15: dffffc0000000000
 tomoyo_encode2.part.0+0x10e/0x3a0 security/tomoyo/realpath.c:56
 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline]
 tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x186/0x620 security/tomoyo/realpath.c:288
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x272/0x380 security/tomoyo/file.c:771
 tomoyo_file_open security/tomoyo/tomoyo.c:313 [inline]
 tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:308
 security_file_open+0x52/0x3f0 security/security.c:1574
 do_dentry_open+0x3a0/0x1290 fs/open.c:815
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1bb9/0x2750 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 __do_sys_openat fs/open.c:1209 [inline]
 __se_sys_openat fs/open.c:1204 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1204
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cba9
Code: Bad RIP value.
RSP: 002b:00007feacc7e1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f93e0 RCX: 000000000045cba9
RDX: 2f606557d6081b8a RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007e6 R14: 00000000004cad80 R15: 00007feacc7e26d4