rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=f224/1/0x4000000000000000 softirq=14828/14828 fqs=44
rcu: 	(detected by 0, t=10506 jiffies, g=8969, q=192 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6112 Comm: syz.2.62 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+0x33/0x50
Code: e8 42 15 12 00 48 89 df e8 9a f9 ff ff 89 c5 31 ff 89 c6 e8 6f 19 12 00 85 ed 78 0c e8 26 15 12 00 eb 1a e8 1f 15 12 00 f3 90 <48> 89 df e8 75 f9 ff ff 85 c0 78 ed 89 c5 e8 0a 15 12 00 89 e8 5b
RSP: 0018:ffffc900001e0990 EFLAGS: 00000006
RAX: ffffffff81adabe1 RBX: ffff88803230a0a8 RCX: ffff888108ee0000
RDX: 0000000000010000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: 00000000ffffffff R08: ffff888136627a83 R09: 1ffff11026cc4f50
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: ffff88803230a150
R13: dffffc0000000000 R14: ffff88803230a0a8 R15: ffffffffffff71c0
FS:  00007f8ef9bd86c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32716ff8 CR3: 000000010d6de000 CR4: 00000000000006f0
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:__futex_unqueue+0x102/0x160
Code: 44 26 70 00 4c 8b 7b 30 4d 8d 77 f8 49 8d 77 40 48 89 df e8 c0 24 c2 09 4c 89 f7 be 04 00 00 00 e8 c3 28 70 00 f0 41 ff 4f f8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 3f 23 ca 09 cc e8 19 a8 0c 00 90
RSP: 0018:ffffc90004d47b70 EFLAGS: 00000246
RAX: ffffffff8b754801 RBX: ffffc90004d67aa0 RCX: ffffffff81b318cd
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88810e7842c0
RBP: 0000000000000001 R08: ffff88810e7842c3 R09: 1ffff11021cf0858
R10: dffffc0000000000 R11: ffffed1021cf0859 R12: dffffc0000000000
R13: ffffc90004d67ad0 R14: ffff88810e7842c0 R15: ffff88810e7842c8
 futex_wake_mark+0xe2/0x200
 futex_wake+0x3bb/0x560
 do_futex+0x395/0x420
 __se_sys_futex+0x36f/0x400
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ef8d8eba9
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:00007f8ef9bd80e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f8ef8fd5fa8 RCX: 00007f8ef8d8eba9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f8ef8fd5fac
RBP: 00007f8ef8fd5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ef8fd6038 R14: 00007ffdd8c8a7d0 R15: 00007ffdd8c8a8b8
 </TASK>
rcu: rcu_preempt kthread starved for 10285 jiffies! g8969 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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  running task     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:
CPU: 0 UID: 0 PID: 5848 Comm: syz-executor 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_many_cond+0xd38/0x12d0
Code: 89 ee 83 e6 01 31 ff e8 56 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 01 5f 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 e5 5e 0b 00 eb e4 44
RSP: 0000:ffffc900025df720 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff11026cc7f61 RCX: ffff888022d95640
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900025df8a0 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: ffff88813663fb08
R13: dffffc0000000000 R14: ffff88804b03b1c0 R15: 0000000000000001
FS:  00005555916c5500(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555916e05c8 CR3: 000000010ecbe000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x6b1/0x12d0
 ptep_clear_flush+0x120/0x170
 do_wp_page+0x1bc2/0x5800
 __handle_mm_fault+0x1033/0x5440
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa81/0x1390
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7fd31194d02f
Code: 8d 34 19 48 39 d5 48 89 75 60 0f 95 c2 48 29 d8 48 83 c1 10 0f b6 d2 48 83 c8 01 48 c1 e2 02 48 09 da 48 83 ca 01 48 89 51 f8 <48> 89 46 08 eb 80 48 8d 0d 31 e9 0e 00 48 8d 15 35 fb 0e 00 bf 01
RSP: 002b:00007ffd1eced040 EFLAGS: 00010206
RAX: 0000000000006a41 RBX: 0000000000008040 RCX: 00005555916d8590
RDX: 0000000000008041 RSI: 00005555916e05c0 RDI: 0000000000000004
RBP: 00007fd311ba7cc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000802 R12: 0000000000008030
R13: 0000000000000076 R14: 00007fd311ba7d20 R15: 0000000000000000
 </TASK>
