rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=61881, q=655 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294984125-4294973623), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g61881 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=18171
rcu: rcu_preempt kthread starved for 10502 jiffies! g61881 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->cpu=1
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 stack:27736 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5059 Comm: udevd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__lock_acquire+0x64c/0x2cf0
Code: ba 01 00 00 00 e8 e4 44 00 00 85 c0 0f 84 f6 0d 00 00 83 bb 74 0b 00 00 00 74 54 48 8b 7c 24 08 4c 89 ee ba 05 00 00 00 eb 38 <85> c9 74 19 31 ed 48 8b 7c 24 08 4c 89 ee 31 d2 e8 af 44 00 00 85
RSP: 0018:ffffc90000a08be0 EFLAGS: 00000046
RAX: 00000000000c406a RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000002 RSI: 0000000000004000 RDI: 0000000000000000
RBP: ffff8881785746b8 R08: ffffffff81b276fa R09: ffff88823c628298
R10: dffffc0000000000 R11: fffffbfff206163f R12: ffffffffffffff02
R13: ffff8881785746b8 R14: ffff888178573b00 R15: 0000000000000000
FS:  00007fe384fc1c80(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc72c7ada40 CR3: 00000001705a4000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lock_acquire+0x106/0x350
 _raw_spin_lock_irq+0x3d/0x50
 __hrtimer_run_queues+0x46a/0xa20
 hrtimer_interrupt+0x44b/0x950
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:widen_string+0x1/0x2a0
Code: 08 48 89 d9 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d eb 15 0f 1f 44 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 50 49 89 cd 49 89 d6 41 89 f4 48 89 fb
RSP: 0018:ffffc90003167340 EFLAGS: 00000286
RAX: ffffffff8ba43599 RBX: dffffc0000000000 RCX: ffffffffffff0a00
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000009
RBP: ffffffff8c20c867 R08: ffff888178573b00 R09: 0000000000000008
R10: 0000000000000007 R11: 0000000000000000 R12: ffffc90003167430
R13: 0000000000000005 R14: 0000000000000405 R15: 0000000000000018
 vsnprintf+0x739/0xee0
 tomoyo_supervisor+0x155/0x1570
 tomoyo_path_permission+0x25a/0x380
 tomoyo_check_open_permission+0x2b2/0x470
 security_file_open+0xa9/0x240
 do_dentry_open+0x4a8/0x13a0
 vfs_open+0x3b/0x340
 path_openat+0x2e08/0x3860
 do_file_open+0x23e/0x4a0
 do_sys_openat2+0x113/0x200
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe384b1a477
Code: 10 00 00 00 44 8b 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 44 89 c2 4c 89 ce bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 76 10 48 8b 15 82 69 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff8e995118 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055a13e65fde0 RCX: 00007fe384b1a477
RDX: 0000000000090800 RSI: 000055a13e647ce0 RDI: 00000000ffffff9c
RBP: 000055a13e695c40 R08: 0000000000090800 R09: 000055a13e647ce0
R10: 0000000000000000 R11: 0000000000000287 R12: 000055a13e647ce0
R13: 00000000000000ff R14: 000055a139d651c4 R15: 0000000000000000
 </TASK>
