rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=da94/1/0x4000000000000000 softirq=81876/81877 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=70261, q=296 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 15965 Comm: syz.3.2506 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:hrtimer_cancel+0x3b/0x50
Code: e8 9a f9 ff ff 89 c5 31 ff 89 c6 e8 cf 19 12 00 85 ed 78 0c e8 86 15 12 00 eb 1a e8 7f 15 12 00 f3 90 48 89 df e8 75 f9 ff ff <85> c0 78 ed 89 c5 e8 6a 15 12 00 89 e8 5b 5d c3 cc cc cc cc cc 90
RSP: 0018:ffffc90000007990 EFLAGS: 00000082
RAX: 00000000ffffffff RBX: ffff88802f220168 RCX: 0000000000010000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: 00000000ffffffff R08: ffff88804b027a83 R09: 1ffff11009604f50
R10: dffffc0000000000 R11: ffffed1009604f51 R12: ffff88802f220210
R13: dffffc0000000000 R14: ffff88802f220168 R15: ffffffffffff4907
FS:  00007f628aa4a6c0(0000) GS:ffff8880b8611000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ee0dff8 CR3: 000000010e1e0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 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:do_syscall_64+0xc3/0x3b0
Code: 00 48 8b 7d 08 48 89 7b 18 e8 09 5a 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 79 af 4c f6 90 90 e8 22 af 4c f6 fb 49 8b 57 08 <f6> c2 3f 74 0e 4c 89 f7 4c 89 ee e8 3d a2 2f f6 49 89 c4 90 90 41
RSP: 0018:ffffc90002b0fef0 EFLAGS: 00000286
RAX: 9d3cd23b6e542600 RBX: ffffc90002b0fef0 RCX: 9d3cd23b6e542600
RDX: 0000000000000000 RSI: ffffffff8d9baf27 RDI: ffffffff8be34480
RBP: ffffc90002b0ff48 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: 00000000000000ca
R13: 00000000000000ca R14: ffffc90002b0ff58 R15: ffff8881088e0000
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6289b8ec29
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:00007f628aa4a0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f6289dd5fa8 RCX: 00007f6289b8ec29
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6289dd5fac
RBP: 00007f6289dd5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6289dd6038 R14: 00007ffc18644730 R15: 00007ffc18644818
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g70261 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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  running task     stack:26568 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:
CPU: 1 UID: 0 PID: 15964 Comm: syz.3.2506 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:smp_call_function_single+0x3ae/0x590
Code: e6 01 31 ff e8 83 7a 0b 00 41 83 e6 01 75 11 e8 38 76 0b 00 4d 89 fe eb 3f e8 2e 76 0b 00 eb 3c 4d 89 fe f3 90 43 0f b6 04 2c <84> c0 75 0f f7 03 01 00 00 00 74 1d e8 11 76 0b 00 eb e6 89 d9 80
RSP: 0018:ffffc90002b2fa40 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffc90002b2fa88 RCX: ffff8881075b5640
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002b2fb30 R08: ffffc90002b2f8e7 R09: 1ffff92000565f1c
R10: dffffc0000000000 R11: fffff52000565f1d R12: 1ffff92000565f51
R13: dffffc0000000000 R14: 1ffff92000565f4c R15: 1ffff92000565f4c
FS:  000055556f59a500(0000) GS:ffff8881a3c11000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd5494d8fc8 CR3: 000000010e1e0000 CR4: 00000000000006f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 event_function_call+0x326/0x970
 perf_event_release_kernel+0x15d/0x510
 perf_release+0x38/0x50
 __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: 0033:0x7f6289b8ec29
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:00007ffc18644978 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000007db72 RCX: 00007f6289b8ec29
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f6289dd7da0 R08: 0000000000000001 R09: 0000001d18644c6f
R10: 0000001b2de20000 R11: 0000000000000246 R12: 00007f6289dd5fac
R13: 00007f6289dd5fa0 R14: ffffffffffffffff R15: 00007ffc18644a90
 </TASK>
