rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=120669, q=322 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295008185-4294997683), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g120669 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=40792
rcu: rcu_preempt kthread starved for 10502 jiffies! g120669 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:27736 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17ba/0x5670
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 18491 Comm: syz.7.2249 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:do_raw_spin_unlock+0xd1/0x210
Code: 84 c0 0f 85 16 01 00 00 41 8b 07 65 8b 0d 2b 5f 96 11 39 c8 0f 85 a8 00 00 00 43 80 7c 25 00 00 74 08 4c 89 f7 e8 2f af 8e 00 <49> c7 06 ff ff ff ff 42 0f b6 44 25 00 84 c0 0f 85 fd 00 00 00 c7
RSP: 0018:ffffc90004d17c90 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff8f160ae0 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8f160ae0
RBP: 1ffffffff1e2c15d R08: ffffffff8f160ae3 R09: 1ffffffff1e2c15c
R10: dffffc0000000000 R11: fffffbfff1e2c15d R12: dffffc0000000000
R13: 1ffffffff1e2c15e R14: ffffffff8f160af0 R15: ffffffff8f160ae8
FS:  000055555a26a500(0000) GS:ffff8882a9296000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2e555456b8 CR3: 00000001724a4000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _raw_spin_unlock_irqrestore+0x23/0x80
 vga_arb_release+0x27f/0x5d0
 __fput+0x44f/0xa60
 task_work_run+0x1d9/0x270
 exit_to_user_mode_loop+0xed/0x480
 do_syscall_64+0x33e/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2d0339cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff0aec188 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffff0aec270 RCX: 00007f2d0339cdd9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000093d7a R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b31b20000 R11: 0000000000000246 R12: 00007ffff0aec2b0
R13: 00007f2d03615fac R14: 0000000000093db8 R15: 00007f2d03615fa0
 </TASK>
