rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=22257, q=338 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294964760-4294954260), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g22257 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=8716
rcu: rcu_preempt kthread starved for 10500 jiffies! g22257 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:26728 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: 8665 Comm: syz.4.711 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:strlen+0x8/0x70
Code: 80 e1 07 38 c1 7c db e8 36 08 ad f6 eb d4 90 0f 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 <41> 54 53 48 c7 c0 ff ff ff ff 49 be 00 00 00 00 00 fc ff df 48 89
RSP: 0018:ffffc900001e0708 EFLAGS: 00000086
RAX: ffffffff8b8cf500 RBX: ffff888136627ab0 RCX: ffff8881256e0000
RDX: ffffffff81adad5e RSI: ffff888136627a98 RDI: ffffffff8b8cf500
RBP: ffffc900001e0808 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: 1ffff9200003c0ec
R13: ffffffff81adad5e R14: ffffffff8e009240 R15: dffffc0000000000
FS:  00007fe3406bd6c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33623ffc CR3: 000000011fcde000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 perf_trace_lock+0xc2/0x3b0
 lock_release+0x3b2/0x3e0
 _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:security_d_instantiate+0x0/0x200
Code: e9 95 fd ff ff e8 a0 ff 44 fd e9 95 fd ff ff e8 96 ff 44 fd e9 95 fd ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 57 41 56 53 48 89 f3 49 89 fe e8 6b ff 44 fd 48
RSP: 0018:ffffc90002f1fd38 EFLAGS: 00000283
RAX: ffffffff823a8c5a RBX: ffff8881117ec2c0 RCX: 0000000000080000
RDX: ffffc90003261000 RSI: ffff8881117ec2c0 RDI: ffff888111782468
RBP: ffffc90002f1fe30 R08: ffff88811178259f R09: 0000000000000000
R10: ffff888111782578 R11: 0000000000000000 R12: ffff888100aba820
R13: ffffffff8f59dc50 R14: ffff888111782468 R15: ffff888111782598
 d_instantiate+0x55/0xa0
 alloc_file_pseudo+0xf6/0x210
 sock_alloc_file+0xb8/0x2e0
 __sys_socket+0x13d/0x1b0
 __x64_sys_socket+0x7a/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe33f78eba9
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:00007fe3406bd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007fe33f9d5fa0 RCX: 00007fe33f78eba9
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000010
RBP: 00007fe33f811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe33f9d6038 R14: 00007fe33f9d5fa0 R15: 00007ffd54a922e8
 </TASK>
