rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=0cac/1/0x4000000000000000 softirq=51225/51225 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=40169, q=266 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12472 Comm: syz.6.1891 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+0x26a/0xd20
Code: 89 fe 48 8b 3c 24 48 83 7c 24 68 00 0f 85 d5 fe ff ff 44 8b 84 24 80 00 00 00 4c 8b 4c 24 70 4c 8d bf f0 0a 00 00 41 83 fd 31 <48> 89 74 24 20 0f 83 5e 0a 00 00 4c 89 6c 24 28 4a 8d 04 ad 00 00
RSP: 0018:ffffc900001e0750 EFLAGS: 00000097
RAX: 0000000000000a0f RBX: ffff888136627a98 RCX: ffffffff9349a310
RDX: 0000000000000000 RSI: 0000000000000067 RDI: ffff88801d3ad640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ada78b
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88801d3ae130
FS:  00007f3c3efb06c0(0000) GS:ffff8881a3c12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34923ffc CR3: 00000001176ae000 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:fput+0x40/0xd0
Code: 01 00 00 bf 01 00 00 00 e8 7d 0c 5b ff 4c 89 f7 be 08 00 00 00 e8 c0 b7 ee ff 49 c7 c7 ff ff ff ff f0 4c 0f c1 bb 60 01 00 00 <49> 8d 77 ff 48 c7 c7 ff ff ff ff e8 a0 c4 8a ff 49 ff cf 78 09 e8
RSP: 0018:ffffc9000175fe90 EFLAGS: 00000257
RAX: 1ffff11003a75d01 RBX: ffff88810a25fe00 RCX: ffffffff82350180
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88810a25ff60
RBP: 0000000000000000 R08: ffff88810a25ff67 R09: 1ffff1102144bfec
R10: dffffc0000000000 R11: ffffed102144bfed R12: 0000000000002402
R13: ffffffff81f2ec50 R14: ffff88810a25ff60 R15: 0000000000000001
 __se_sys_ioctl+0x168/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3c3e18ec29
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:00007f3c3efb0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3c3e3d5fa0 RCX: 00007f3c3e18ec29
RDX: 0000000000000001 RSI: 0000000000002402 RDI: 0000000000000004
RBP: 00007f3c3e211e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3c3e3d6038 R14: 00007f3c3e3d5fa0 R15: 00007ffcc9011848
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g40169 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=16182
rcu: rcu_preempt kthread starved for 10502 jiffies! g40169 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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: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>
