rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=20913, q=516 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294960255-4294949753), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g20913 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=6707
rcu: rcu_preempt kthread starved for 10502 jiffies! g20913 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+0x3fc/0x770
 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: 7509 Comm: syz.6.274 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_acquire+0x332/0xd20
Code: e5 15 09 d5 09 cd 44 09 f5 41 89 6c c7 20 45 89 44 c7 24 4c 89 7c 24 10 4d 8d 34 c7 81 e5 ff 1f 00 00 48 0f a3 2d fe b1 0a 12 <73> 10 48 69 c5 c8 00 00 00 48 8d 80 10 13 49 93 eb 40 83 3d 65 41
RSP: 0018:ffffc900062cfb10 EFLAGS: 00000003
RAX: 0000000000000005 RBX: ffffffff8e9158d8 RCX: 00000000000001ec
RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffff888108fc9cc0
RBP: 00000000000001ec R08: 0000000000000000 R09: ffffffff85120ad2
R10: dffffc0000000000 R11: fffffbfff1d22b19 R12: 0000000000000000
R13: 0000000000000000 R14: ffff888108fca7d8 R15: ffff888108fca7b0
FS:  0000555577808500(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000003c0 CR3: 0000000033350000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 vga_arb_release+0x232/0xaa0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f40ad18ebe9
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:00007ffe9c49f518 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f40ad3b7da0 RCX: 00007f40ad18ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f40ad3b7da0 R08: 0000000000000000 R09: 0000000d9c49f80f
R10: 000000000003fd5c R11: 0000000000000246 R12: 000000000001ef79
R13: 00007f40ad3b6090 R14: ffffffffffffffff R15: 00007ffe9c49f630
 </TASK>
