rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7820/3:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=18685, q=412 ncpus=2)
task:syz.5.400       state:R  running task     stack:20688 pid:7820  tgid:7820  ppid:6783   task_flags:0x400640 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
 filemap_map_pages+0x1121/0x1740
 __handle_mm_fault+0x34ac/0x5440
 handle_mm_fault+0x40a/0x8e0
 __get_user_pages+0x1699/0x2ce0
 get_dump_page+0x1ac/0x3f0
 dump_user_range+0x1de/0xc90
 elf_core_dump+0x3364/0x3960
 coredump_write+0x1169/0x1900
 vfs_coredump+0x1daa/0x2a50
 get_signal+0x1108/0x1340
 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: 0033:0x7f257838ec31
RSP: 002b:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f25785d5fa0 RCX: 00007f257838ec29
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007f2578411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f25785d6038 R14: 00007f25785d5fa0 R15: 00007fff040e8fe8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g18685 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=6678
rcu: rcu_preempt kthread starved for 10502 jiffies! g18685 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: 7831 Comm: syz.5.403 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+0xa4f/0xd20
Code: e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 78 40 00 0f 84 8c 02 00 00 41 8b 46 20 25 ff 1f 00 00 48 0f a3 05 b1 66 b6 11 <73> 10 48 69 c0 c8 00 00 00 48 8d 80 30 83 f3 92 eb 40 83 3d 18 f6
RSP: 0018:ffffc90000007750 EFLAGS: 00000003
RAX: 0000000000000067 RBX: 0000000000000000 RCX: 0000000090213bdc
RDX: 00000000001a71fd RSI: 00000000727d5714 RDI: ffff88811df2ba00
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81ac490b
R10: dffffc0000000000 R11: ffffed1009644f59 R12: 0000000000000068
R13: ffff88811df2c530 R14: ffff88811df2c530 R15: d6bf87c490213bdc
FS:  00007f25792116c0(0000) GS:ffff8880b8d73000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000108c6e000 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_release+0x2b5/0x3e0
Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 7b ad ae 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900026df7f0 EFLAGS: 00000206
RAX: cc0370f6e9ea1d00 RBX: 0000000000000206 RCX: cc0370f6e9ea1d00
RDX: 0000000000000000 RSI: ffffffff8d71ebcb RDI: ffffffff8b9ec2e0
RBP: ffff88811df2c530 R08: ffffc900026df978 R09: 0000000000000000
R10: ffffc900026df9d8 R11: fffff520004dbf3d R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8dd3a960 R15: ffff88811df2ba00
 unwind_next_frame+0x19a9/0x2390
 __unwind_start+0x5b9/0x760
 arch_stack_walk+0xe4/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 getname_flags+0xb8/0x540
 do_sys_openat2+0xbc/0x1c0
 __x64_sys_openat+0x138/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f257838ec29
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:00007f2579211038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f25785d5fa0 RCX: 00007f257838ec29
RDX: 00000000000026e1 RSI: 0000000000000000 RDI: ffffffffffffff9c
RBP: 00007f2578411e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f25785d6038 R14: 00007f25785d5fa0 R15: 00007fff040e8fe8
 </TASK>
