rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9503/1:b..l
rcu: 	(detected by 1, t=10504 jiffies, g=27709, q=152 ncpus=2)
task:syz.7.669       state:R  running task     stack:20624 pid:9503  tgid:9503  ppid:7451   task_flags:0x40064c flags:0x00080001
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 preempt_schedule_common+0x83/0xd0
 preempt_schedule+0xae/0xc0
 preempt_schedule_thunk+0x16/0x30
 _raw_spin_unlock+0x3f/0x50
 unmap_page_range+0x3a79/0x4370
 unmap_vmas+0x399/0x580
 exit_mmap+0x248/0xb50
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 get_signal+0x1285/0x1340
 arch_do_signal_or_restart+0xa0/0x790
 irqentry_exit_to_user_mode+0x7e/0x110
 exc_page_fault+0x9f/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f129f38ec31
RSP: 002b:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f129f5d5fa0 RCX: 00007f129f38ec29
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007f129f411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f129f5d6038 R14: 00007f129f5d5fa0 R15: 00007ffd280d58e8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g27709 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=14383
rcu: rcu_preempt kthread starved for 10500 jiffies! g27709 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:27256 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9526 Comm: syz.7.676 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+0x252/0xd20
Code: e9 78 0a 00 00 48 c7 c7 50 b6 c0 8d 49 89 f7 4c 89 ee e8 b1 ca 20 03 4c 89 fe 48 8b 3c 24 48 83 7c 24 68 00 0f 85 d5 fe ff ff <44> 8b 84 24 80 00 00 00 4c 8b 4c 24 70 4c 8d bf 30 0b 00 00 41 83
RSP: 0018:ffffc90000007750 EFLAGS: 00000046
RAX: 0000000000000a0f RBX: ffff88804b227ad8 RCX: ffffffff92f38330
RDX: 0000000000000003 RSI: 0000000000000067 RDI: ffff88801e769d00
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: ffffed1009644f59 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f12a019d6c0(0000) GS:ffff8880b8d73000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003000 CR3: 000000003c0d4000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire+0x120/0x360
 _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+0x3b8/0x500
 __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:lock_is_held_type+0x137/0x190
Code: 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 39 62 13 07 <48> 3b 44 24 08 75 43 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9000322f660 EFLAGS: 00000206
RAX: bca3d354931b9500 RBX: 0000000000000001 RCX: bca3d354931b9500
RDX: ffff88801e769d00 RSI: ffffffff8d71ebcb RDI: ffffffff8b9ec2e0
RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffffff820a62c1
R10: dffffc0000000000 R11: fffffbfff1eb9aa7 R12: 0000000000000246
R13: ffff88801e769d00 R14: ffffffff8dd3a960 R15: 0000000000000002
 count_memcg_event_mm+0x103/0x260
 handle_mm_fault+0x50f/0x8e0
 do_user_addr_fault+0x764/0x1380
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30
RIP: 0010:rep_movs_alternative+0x75/0x90
Code: 05 e9 7f 0e 04 00 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 29 f8 48 01 c7 48 01 c6 48 29 c1 48 89 c8 48 c1 e9 03 83 e0 07 <f3> 48 a5 89 c1 85 c9 75 91 e9 4d 0e 04 00 48 8d 0c c8 eb 86 cc cc
RSP: 0018:ffffc9000322f8f8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88801f746000 RCX: 0000000000000038
RDX: 0000000000000001 RSI: 0000200000003000 RDI: ffff88801f746e40
RBP: ffffc9000322fa68 R08: ffff88801f746fff R09: 1ffff11003ee8dff
R10: dffffc0000000000 R11: ffffed1003ee8e00 R12: 1ffff92000645faf
R13: 00002000000021c0 R14: ffffc9000322fd88 R15: 0000000000001000
 _copy_from_iter+0x24f/0x1790
 copy_page_from_iter+0xdd/0x170
 anon_pipe_write+0x9f8/0x1460
 vfs_write+0x5c9/0xb30
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f129f38ec29
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:00007f12a019d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f129f5d5fa0 RCX: 00007f129f38ec29
RDX: 00000000fffffdef RSI: 00002000000001c0 RDI: 0000000000000000
RBP: 00007f129f411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f129f5d6038 R14: 00007f129f5d5fa0 R15: 00007ffd280d58e8
 </TASK>
