rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10506 jiffies, g=49873, q=385 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10506 (4294980064-4294969558), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g49873 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=17897
rcu: rcu_preempt kthread starved for 10506 jiffies! g49873 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:27160 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: 14457 Comm: syz.0.2552 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:asm_exc_int3+0x25/0x40
Code: b1 08 00 00 90 f3 0f 1e fa 0f 1f 00 fc 6a ff f6 44 24 10 03 75 18 ff 74 24 28 ff 74 24 28 ff 74 24 28 ff 74 24 28 ff 74 24 28 <ff> 74 24 28 e8 42 07 00 00 48 89 c4 48 89 e7 e8 b7 ab 7a 0a e9 72
RSP: 0018:ffffc900000077b8 EFLAGS: 00000046
RAX: e5599b9e9088e200 RBX: 0000000000000802 RCX: ffff888020fd8000
RDX: 0000000000010000 RSI: ffffffff81ada91e RDI: ffff88804b027a98
RBP: ffffc90000007918 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f00 R12: dffffc0000000000
R13: ffffffff81ada91e R14: ffff88804b027a98 R15: 1ffff92000000f10
FS:  00007f2b650656c0(0000) GS:ffff8880b8612000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000010f6ca000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
RIP: 0010:lock_release+0x26/0x3e0
Code: 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 a0 5f 03 11 48 89 44 24 28 cc <3a> 03 00 00 65 8b 05 a3 5f 03 11 83 f8 08 0f 83 9a 02 00 00 89 c0
RSP: 0018:ffffc90000007818 EFLAGS: 00000086
 _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:check_preemption_disabled+0x35/0x120
Code: 48 8b 05 be ce 25 07 48 89 44 24 08 65 8b 05 c6 ce 25 07 65 8b 0d bb ce 25 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 9b ce 25 07 <48> 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9
RSP: 0018:ffffc9000ab6f540 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff8164d1ea RCX: e5599b9e9088e200
RDX: 0000000000000001 RSI: ffffffff8be34460 RDI: ffffffff8be34420
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc9000ab6f6b8 R11: ffffffff81ac4d00 R12: 1ffff9200156decd
R13: ffffc9000ab6f6a0 R14: ffffc9000ab6f668 R15: ffffffff8172d195
 rcu_is_watching+0x15/0xb0
 unwind_next_frame+0xd4/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 taskstats_exit+0x14a/0xa30
 do_exit+0x630/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b6418ec29
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:00007f2b650650e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f2b643d5fa8 RCX: 00007f2b6418ec29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2b643d5fa8
RBP: 00007f2b643d5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2b643d6038 R14: 00007ffe33511460 R15: 00007ffe33511548
 </TASK>
