rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=b7e4/1/0x4000000000000000 softirq=21885/21885 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=13045, q=339 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6812 Comm: syz.6.187 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:lock_release+0x44/0x3e0
Code: 8b 05 a0 4f 03 11 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 a3 4f 03 11 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 8c 27 06 0e <73> 16 e8 45 f1 08 00 84 c0 75 0d f6 05 fb 0b f0 0d 01 0f 84 ad 02
RSP: 0000:ffffc90002a2f758 EFLAGS: 00000093
RAX: 0000000000000000 RBX: 0000000000000802 RCX: ffff888106b5b980
RDX: 0000000000010000 RSI: ffffffff81ada91e RDI: ffff88804b027a98
RBP: ffffc90002a2f858 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000545ee8 R12: dffffc0000000000
R13: ffffffff81ada91e R14: ffff88804b027a98 R15: 1ffff92000545ef8
FS:  00007f78b3e836c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31416ff8 CR3: 0000000039ef8000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 _raw_spin_unlock_irqrestore+0x70/0x110
 hrtimer_try_to_cancel+0x3be/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: 0033:0x7f78b2f8eba9
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:00007f78b3e830e8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f78b31d5fa8 RCX: 00007f78b2f8eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f78b31d5fa8
RBP: 00007f78b31d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78b31d6038 R14: 00007ffe2b1ba720 R15: 00007ffe2b1ba808
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g13045 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=7885
rcu: rcu_preempt kthread starved for 10502 jiffies! g13045 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27224 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>
