rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P17340/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=83581, q=566 ncpus=2)
task:dhcpcd-run-hook state:R  running task     stack:24048 pid:17340 tgid:17340 ppid:5594   task_flags:0x400000 flags:0x00004002
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
 change_protection+0x36d6/0x4060
 mprotect_fixup+0x6fe/0x9c0
 do_mprotect_pkey+0x8cd/0xce0
 __x64_sys_mprotect+0x80/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e22fcbbb7
RSP: 002b:00007ffdcf51aea8 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007f0e22fa6a00 RCX: 00007f0e22fcbbb7
RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007f0e22d2e000
RBP: 00007ffdcf51afc0 R08: 00007ffdcf51ae38 R09: 00007f0e22fa6500
R10: 00007f0e22d22c08 R11: 0000000000000206 R12: 00007f0e22fa6a00
R13: 00007f0e22fd3eda R14: 00007f0e22d2ef98 R15: 00007f0e22d2ed98
 </TASK>
rcu: rcu_preempt kthread starved for 10489 jiffies! g83581 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:26440 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17343 Comm: syz.7.2540 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:do_raw_spin_unlock+0x61/0x240
Code: 4e ad de 0f 85 f3 00 00 00 48 89 df be 04 00 00 00 e8 63 cf 85 00 48 89 d8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 74 01 00 00 <83> 3b 00 0f 84 ea 00 00 00 4c 8d 73 10 4d 89 f5 49 c1 ed 03 43 80
RSP: 0018:ffffc900001e0848 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888136627a80 RCX: ffffffff819e1c4d
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888136627a80
RBP: ffffc900001e0918 R08: ffff888136627a83 R09: 1ffff11026cc4f50
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: dffffc0000000000
R13: ffff888136627b00 R14: ffff888136627a84 R15: 1ffff9200003c110
FS:  00007f35877f66c0(0000) GS:ffff8881a3c11000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000010f45c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_unlock_irqrestore+0x78/0x110
 hrtimer_try_to_cancel+0x3be/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:unwind_next_frame+0x2b4/0x2390
Code: 00 00 fc ff df 0f 84 03 02 00 00 4a 8d 14 ad 50 ae b1 8f 45 29 e8 4a 8d 1c 82 48 83 c3 fc 49 89 d5 48 39 da 0f 86 1c 10 00 00 <49> 29 d5 e9 80 00 00 00 31 db e9 eb 16 00 00 49 81 fc 00 70 0a 91
RSP: 0018:ffffc9000345f758 EFLAGS: 00000202
RAX: ffffffff8fb6ed9c RBX: ffffffff8fb6eda0 RCX: ffffffff8fb6eda4
RDX: ffffffff8fb6eda0 RSI: ffffffff9032a89c RDI: ffffffff8be34420
RBP: ffffffff8fb6eda4 R08: 0000000000000007 R09: ffffffff8172d195
R10: ffffc9000345f8d8 R11: fffff5200068bf1d R12: ffffffff81699b03
R13: ffffffff8fb6eda0 R14: ffffc9000345f888 R15: ffffffff8fb6eda0
 __unwind_start+0x5b9/0x760
 arch_stack_walk+0xe4/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 find_get_pmu_context+0x8b/0x890
 __se_sys_perf_event_open+0xbfd/0x1d70
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f358958ec29
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:00007f35877f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f35897d5fa0 RCX: 00007f358958ec29
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007f3589611e41 R08: 000000000000000a R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f35897d6038 R14: 00007f35897d5fa0 R15: 00007ffd02467b58
 </TASK>
