rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=0644/1/0x4000000000000000 softirq=23362/23362 fqs=0
rcu: 	(detected by 1, t=10505 jiffies, g=17289, q=182 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7629 Comm: syz.1.445 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:check_preemption_disabled+0x17/0x120
Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 be 3e 26 07 48 89 44 24 08 <65> 8b 05 c6 3e 26 07 65 8b 0d bb 3e 26 07 f7 c1 ff ff ff 7f 74 23
RSP: 0018:ffffc900000077a8 EFLAGS: 00000082
RAX: e8c4fcfeb76e0000 RBX: 0000000000000000 RCX: e8c4fcfeb76e0000
RDX: 0000000000000000 RSI: ffffffff8d9cdfe0 RDI: ffffffff8be33e80
RBP: ffffffff81ada78b R08: 0000000000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: ffffed1009604f51 R12: 0000000000000000
R13: ffff88804b027a98 R14: 0000000000000001 R15: 0000000000000046
FS:  00007febdd2216c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 0000000026d66000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire+0xe7/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 hrtimer_try_to_cancel+0x22b/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:__fget_files+0x109/0x420
Code: 43 80 3c 26 00 74 08 4c 89 ff e8 32 a3 e6 ff 4d 8b 2f 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 cd 02 00 00 41 8b 45 00 <8b> 4c 24 04 39 c1 48 19 db 49 8d 6d 08 48 89 e8 48 c1 e8 03 42 80
RSP: 0018:ffffc90003f1fd18 EFLAGS: 00000246
RAX: 0000000000000100 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000efd8000 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 0000000000000002 R08: 0000000000000000 R09: ffffffff823cc44a
R10: dffffc0000000000 R11: ffffed1020a9d301 R12: dffffc0000000000
R13: ffff888023867980 R14: 1ffff11020a9d30b R15: ffff8881054e9858
 fdget+0x16c/0x1e0
 __x64_sys_sendmsg+0xf4/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7febdc38eba9
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:00007febdd221038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007febdc5d5fa0 RCX: 00007febdc38eba9
RDX: 0000000004000000 RSI: 00002000000003c0 RDI: ffffffffffffffff
RBP: 00007febdc411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007febdc5d6038 R14: 00007febdc5d5fa0 R15: 00007ffef6c152a8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g17289 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=6608
rcu: rcu_preempt kthread starved for 10505 jiffies! g17289 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26896 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>
