rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=49193, q=677 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294981722-4294971220), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g49193 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=23479
rcu: rcu_preempt kthread starved for 10502 jiffies! g49193 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: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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14509 Comm: syz.8.2494 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:validate_chain+0xaa/0x2140
Code: dc a5 e5 ff 90 0f 0b 90 90 90 48 bb eb 83 b5 80 46 86 c8 61 49 0f af df 48 c1 eb 2d 48 8b 04 dd 40 a3 64 93 48 85 c0 0f 94 c1 <48> 83 c0 f8 0f 94 c2 08 ca 0f 84 24 01 00 00 e8 e2 9b ff ff 83 3d
RSP: 0018:ffffc90000007638 EFLAGS: 00000086
RAX: ffffffff93a8c018 RBX: 000000000002c50a RCX: 0000000000040000
RDX: 0000000000000001 RSI: ffff8880210b4470 RDI: ffff8880210b3980
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81ada78b
R10: dffffc0000000000 R11: ffffed1009604f51 R12: 0000000000000001
R13: ffff8880210b4470 R14: ffff8880210b4470 R15: d6bf87c490213bdc
FS:  00007f4dca4666c0(0000) GS:ffff8880b8612000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32763fff CR3: 0000000037722000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __lock_acquire+0xab9/0xd20
 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: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 39 eb 4c f6 90 90 e8 e2 ea 4c f6 fb 49 8b 57 08 <f6> c2 3f 74 0e 4c 89 f7 4c 89 ee e8 fd dd 2f f6 49 89 c4 90 90 41
RSP: 0018:ffffc900046afef0 EFLAGS: 00000286
RAX: f4ec1d6f49114a00 RBX: ffffc900046afef0 RCX: f4ec1d6f49114a00
RDX: 0000000000000000 RSI: ffffffff8d9bab7c RDI: ffffffff8be34280
RBP: ffffc900046aff48 R08: ffffffff8fa3b337 R09: 1ffffffff1f47666
R10: dffffc0000000000 R11: fffffbfff1f47667 R12: 0000000000000010
R13: 0000000000000010 R14: ffffc900046aff58 R15: ffff8880210b3980
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4dc958ec29
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:00007f4dca466038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4dc97d5fa0 RCX: 00007f4dc958ec29
RDX: 0000000000000006 RSI: 0000000000002402 RDI: 0000000000000003
RBP: 00007f4dc9611e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4dc97d6038 R14: 00007f4dc97d5fa0 R15: 00007ffc0b7866e8
 </TASK>
