rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10506 jiffies, g=33025, q=116 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10492 (4294972674-4294962182), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10491 jiffies! g33025 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=15385
rcu: rcu_preempt kthread starved for 10492 jiffies! g33025 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:26664 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: 10736 Comm: syz.1.1397 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+0x70/0x3e0
Code: e8 45 f1 08 00 84 c0 75 0d f6 05 fb 0b f0 0d 01 0f 84 ad 02 00 00 83 3d 9d 58 06 0e 00 0f 84 44 02 00 00 65 8b 05 60 8f 03 11 <85> c0 0f 85 35 02 00 00 65 4c 8b 3c 25 08 d0 a0 92 41 83 bf ec 0a
RSP: 0018:ffffc900001e0818 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffffffff81ada91e RCX: 54246b250ce4a100
RDX: ffffffff81ada91e RSI: ffffffff8be33de0 RDI: ffffffff8be33da0
RBP: ffffc900001e0918 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: dffffc0000000000
R13: ffffffff81ada91e R14: ffff888136627a98 R15: ffff888136627a98
FS:  00007f59efa096c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c11ff8 CR3: 000000002648c000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000200000000300
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _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+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:do_syscall_64+0xc3/0x3b0
Code: 00 48 8b 7d 08 48 89 7b 18 e8 09 5a 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 d9 6a 4d f6 90 90 e8 82 6a 4d f6 fb 49 8b 57 08 <f6> c2 3f 74 0e 4c 89 f7 4c 89 ee e8 fd 5d 30 f6 49 89 c4 90 90 41
RSP: 0018:ffffc9000786fef0 EFLAGS: 00000286
RAX: 54246b250ce4a100 RBX: ffffc9000786fef0 RCX: 54246b250ce4a100
RDX: 0000000000000000 RSI: ffffffff8d9ba160 RDI: ffffffff8be33e00
RBP: ffffc9000786ff48 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: 0000000000000101
R13: 0000000000000101 R14: ffffc9000786ff58 R15: ffff88802e430000
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f59eeb8eba9
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:00007f59efa09038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f59eedd5fa0 RCX: 00007f59eeb8eba9
RDX: 00000000000026e1 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f59eec11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f59eedd6038 R14: 00007f59eedd5fa0 R15: 00007ffccf1a9ab8
 </TASK>
