rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=3634/1/0x4000000000000000 softirq=81485/81486 fqs=41
rcu: 	(detected by 0, t=10502 jiffies, g=80381, q=203 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 22520 Comm: syz.0.4875 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:mark_lock+0x0/0x190
Code: 89 df 48 8b 2c 24 e9 b0 fd ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 83
RSP: 0018:ffffc900001dfe48 EFLAGS: 00000046
RAX: 00000000000c6067 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffff888108608b40 RDI: ffff888108608000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ada78b
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: 0000000000000002
R13: 0000000000000002 R14: ffff888108608b40 R15: 0000000000000000
FS:  00007fa10fb8b6c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3251cff8 CR3: 000000012bcb2000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __lock_acquire+0x65a/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 hrtimer_try_to_cancel+0x22b/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__kernel_text_address+0xd/0x40
Code: e8 18 b1 96 00 eb b3 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 53 48 89 fb e8 43 00 00 00 <85> c0 0f 95 c0 48 81 fb 00 50 0a 91 0f 93 c1 48 81 fb 30 a9 20 91
RSP: 0018:ffffc900001e07b8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8185070a RCX: 1e0270bfc7590101
RDX: 0000000000000002 RSI: ffffffff8dba9863 RDI: ffffffff8185070a
RBP: ffffc900001e0870 R08: ffffc900001e0f50 R09: 0000000000000000
R10: ffffc900001e0838 R11: fffff5200003c109 R12: ffff888108608000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200003c106
 unwind_get_return_address+0x4d/0x90
 arch_stack_walk+0xfc/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kmem_cache_free+0x18f/0x400
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:tomoyo_check_acl+0x191/0x400
Code: c1 e8 03 0f b6 04 18 84 c0 0f 85 02 01 00 00 49 8b 37 48 8b 3c 24 e8 6e bd ff ff 84 c0 0f 85 2d 02 00 00 e8 a1 df 41 fd eb 0c <e8> 9a df 41 fd eb 05 e8 93 df 41 fd 4c 89 f0 48 c1 e8 03 0f b6 04
RSP: 0018:ffffc90009c57b90 EFLAGS: 00000293
RAX: ffffffff847de15d RBX: dffffc0000000000 RCX: 0000000000000002
RDX: ffff888108608000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff88801ff23710 R08: ffff888108608000 R09: 0000000000000002
R10: 000000000000005c R11: ffffffff847e3670 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880355ff080 R15: 0000000000000002
 tomoyo_path_number_perm+0x2dc/0x5a0
 security_file_ioctl+0xcb/0x2d0
 __se_sys_ioctl+0x47/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa10ed8eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa10fb8b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa10efd5fa0 RCX: 00007fa10ed8eba9
RDX: 0000200000000040 RSI: 00000000401054d5 RDI: 0000000000000004
RBP: 00007fa10ee11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa10efd6038 R14: 00007fa10efd5fa0 R15: 00007ffc1fdf19d8
 </TASK>
rcu: rcu_preempt kthread starved for 10418 jiffies! g80381 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:26728 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5910 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events fqdir_free_fn
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70
Code: 08 d0 a0 92 65 8b 15 b8 0e e1 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 <83> fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c
RSP: 0018:ffffc9000412f8b8 EFLAGS: 00000246
RAX: ffffffff81b44b4f RBX: ffffc9000412f908 RCX: ffff888020eb8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000412f9b8 R08: ffffc9000412f767 R09: 1ffff92000825eec
R10: dffffc0000000000 R11: fffff52000825eed R12: 1ffff92000825f21
R13: dffffc0000000000 R14: 1ffff92000825f1c R15: 1ffff92000825f1c
FS:  0000000000000000(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32509ff8 CR3: 00000001016d2000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 smp_call_function_single+0x3bf/0x590
 rcu_barrier+0x360/0x570
 fqdir_free_fn+0x33/0x140
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
