rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10506 jiffies, g=15657, q=275 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10506 (4294960116-4294949610), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g15657 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=8684
rcu: rcu_preempt kthread starved for 10506 jiffies! g15657 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->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 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>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7892 Comm: syz.1.575 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_acquire+0x649/0xd20
Code: 26 00 00 48 8b 3c 24 85 c0 0f 84 77 06 00 00 83 bf d4 0a 00 00 00 74 55 48 8b 3c 24 4c 89 f6 ba 05 00 00 00 eb 36 85 c9 74 1d <45> 31 ff 48 8b 3c 24 4c 89 f6 31 d2 e8 d6 25 00 00 48 8b 3c 24 85
RSP: 0018:ffffc90000007750 EFLAGS: 00000002
RAX: 00000000000c4067 RBX: 0000000000000002 RCX: 0000000000000001
RDX: 0000000000000002 RSI: 0000000000004000 RDI: ffff888107791cc0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81adabcb
R10: dffffc0000000000 R11: ffffed1009604f51 R12: ffffffffffffff02
R13: 0000000000000002 R14: ffff8881077927b0 R15: 0000000000000000
FS:  00007f21eb3966c0(0000) GS:ffff8880b8611000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558af6a5c8 CR3: 00000000205e2000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 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+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110
Code: 74 05 e8 6b c0 49 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 23 65 12 f6 65 8b 05 6c 41 23 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90006887560 EFLAGS: 00000206
RAX: 3cd5579e9aedb000 RBX: 0000000000000a06 RCX: 3cd5579e9aedb000
RDX: 0000000000000000 RSI: ffffffff8d9baf27 RDI: 0000000000000001
RBP: ffffc900068875f0 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: dffffc0000000000
R13: ffff88810ebffc78 R14: ffffffff99d20388 R15: 1ffff92000d10eac
 debug_object_activate+0x2e2/0x420
 call_rcu+0xaa/0x9c0
 kmem_cache_free+0x309/0x400
 __fput_deferred+0x227/0x390
 fput_close+0x119/0x200
 path_openat+0x313c/0x3830
 do_filp_open+0x1fa/0x410
 do_sys_openat2+0x121/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f21ea58d590
Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 49 94 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 9c 94 02 00 8b 44
RSP: 002b:00007f21eb395f10 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f21ea58d590
RDX: 0000000000000002 RSI: 00007f21eb395fa0 RDI: 00000000ffffff9c
RBP: 00007f21eb395fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f21ea7d6038 R14: 00007f21ea7d5fa0 R15: 00007ffde5e1bb78
 </TASK>
