rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=21585, q=518 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4294967572-4294957072), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g21585 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=10958
rcu: rcu_preempt kthread starved for 10500 jiffies! g21585 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: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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7862 Comm: syz.3.426 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_release+0x5/0x3e0
Code: 03 48 8b 3c 24 e9 08 fa ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 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 41 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b
RSP: 0018:ffffc900001e0870 EFLAGS: 00000082
RAX: f3f3f300f1f1f1f1 RBX: 0000000000000802 RCX: ffff88811c4b5640
RDX: 0000000000010000 RSI: ffffffff81adad5e RDI: ffff888136627a98
RBP: ffffc900001e0918 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: dffffc0000000000
R13: ffff888136627b00 R14: ffff888136627a80 R15: 1ffff9200003c110
FS:  00007f22fa6226c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001f40 CR3: 000000011bb6a000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _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:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 3b 5b 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90001d473f8 EFLAGS: 00000206
RAX: 3164e1f588a25a00 RBX: 0000000000000000 RCX: 3164e1f588a25a00
RDX: 0000000000000001 RSI: ffffffff8dba9835 RDI: ffffffff8be33e00
RBP: ffffffff8172d195 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc90001d475b8 R11: ffffffff81ac5140 R12: 0000000000000002
R13: ffffffff8e13a160 R14: 0000000000000000 R15: 0000000000000246
 unwind_next_frame+0xc2/0x2390
 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
 alloc_empty_file+0x55/0x1d0
 path_openat+0x107/0x3830
 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: 0033:0x7f22f978d510
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:00007f22fa621f10 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f22f978d510
RDX: 0000000000000002 RSI: 00007f22fa621fa0 RDI: 00000000ffffff9c
RBP: 00007f22fa621fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f22f99d6038 R14: 00007f22f99d5fa0 R15: 00007ffe87799c48
 </TASK>
