rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=24745, q=244 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294965800-4294955300), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g24745 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=11289
rcu: rcu_preempt kthread starved for 10500 jiffies! g24745 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:26632 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9276 Comm: syz.2.1018 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:hrtimer_cancel+0x36/0x50
Code: 12 00 48 89 df e8 9a f9 ff ff 89 c5 31 ff 89 c6 e8 cf 19 12 00 85 ed 78 0c e8 86 15 12 00 eb 1a e8 7f 15 12 00 f3 90 48 89 df <e8> 75 f9 ff ff 85 c0 78 ed 89 c5 e8 6a 15 12 00 89 e8 5b 5d c3 cc
RSP: 0018:ffffc900001e0990 EFLAGS: 00000006
RAX: ffffffff81adb021 RBX: ffff88802f068168 RCX: ffff88810847b980
RDX: 0000000000010000 RSI: 0000000000000004 RDI: ffff88802f068168
RBP: 00000000ffffffff R08: ffff888136627a83 R09: 1ffff11026cc4f50
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: ffff88802f068210
R13: dffffc0000000000 R14: ffff88802f068168 R15: ffffffffffff8e9c
FS:  00007f98ee1b56c0(0000) GS:ffff8881a3c11000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000002e834000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 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+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 3b 7b 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900099174d8 EFLAGS: 00000206
RAX: ea218b25ea234800 RBX: 0000000000000000 RCX: ea218b25ea234800
RDX: 0000000000000000 RSI: ffffffff8dbaa624 RDI: ffffffff8be34480
RBP: ffffffff8172d195 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc90009917698 R11: ffffffff81ac5140 R12: 0000000000000002
R13: ffffffff8e13a160 R14: 0000000000000000 R15: 0000000000000246
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 tomoyo_realpath_from_path+0xe3/0x5d0
 tomoyo_path_perm+0x213/0x4b0
 security_inode_getattr+0x12f/0x330
 __x64_sys_newfstat+0xfc/0x200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98ed38ec29
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:00007f98ee1b5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 00007f98ed5d5fa0 RCX: 00007f98ed38ec29
RDX: 0000000000000000 RSI: 0000200000000340 RDI: 0000000000000006
RBP: 00007f98ed411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f98ed5d6038 R14: 00007f98ed5d5fa0 R15: 00007fff6f7ac9d8
 </TASK>
