rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=706/1/0x4000000000000000 softirq=37489/37489 fqs=0 
	(detected by 1, t=10502 jiffies, g=53845, q=65)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 20401 Comm: syz-executor.0 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:398 [inline]
RIP: 0010:lock_acquire+0x17f/0x720 kernel/locking/lockdep.c:4961
Code: a0 00 00 00 41 57 e8 90 07 00 00 48 83 c4 20 48 8b 6c 24 20 48 ba 00 00 00 00 00 fc ff df 8a 44 15 00 84 c0 0f 85 f5 03 00 00 <4c> 8b 74 24 18 41 ff 0e 0f 85 86 02 00 00 48 c7 c0 f0 c7 4b 89 48
RSP: 0018:ffffc90000007d18 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff815a81e4
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8b3a54f8
RBP: 1ffff1100857dd19 R08: dffffc0000000000 R09: fffffbfff1674aa0
R10: fffffbfff1674aa0 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880ae827598 R15: 0000000000000000
FS:  00007f6fd529f700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3e4583dfc0 CR3: 0000000054305000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x67/0x80 kernel/locking/spinlock.c:167
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x4b1/0x930 kernel/time/hrtimer.c:1584
 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1646
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline]
 __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_apic_timer_interrupt+0xb9/0x130 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:587
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x57/0x80 kernel/locking/spinlock.c:199
Code: 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 00 c8 4b 89 e8 ea 7c 93 f9 48 83 3d 52 a8 2b 01 00 74 25 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 3f 7a 30 f9 65 8b 05 44 de e1 77 85 c0 74 02 5b
RSP: 0018:ffffc900025bfa80 EFLAGS: 00000282
RAX: 1ffffffff1297900 RBX: ffff8880a8f01220 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff88201f7f
RBP: 1ffff920004b7f74 R08: dffffc0000000000 R09: fffffbfff1674ab2
R10: fffffbfff1674ab2 R11: 0000000000000000 R12: 00000000000001e1
R13: 1ffff110151e0282 R14: 0000000000000000 R15: dffffc0000000000
 spin_unlock_irq include/linux/spinlock.h:403 [inline]
 shmem_getpage_gfp+0x1237/0x2c60 mm/shmem.c:1868
 shmem_getpage mm/shmem.c:153 [inline]
 shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2459
 generic_perform_write+0x23b/0x4e0 mm/filemap.c:3318
 __generic_file_write_iter+0x22b/0x4e0 mm/filemap.c:3447
 generic_file_write_iter+0x4a6/0x650 mm/filemap.c:3479
 call_write_iter include/linux/fs.h:1908 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0xa08/0xc70 fs/read_write.c:578
 ksys_pwrite64 fs/read_write.c:685 [inline]
 __do_sys_pwrite64 fs/read_write.c:695 [inline]
 __se_sys_pwrite64 fs/read_write.c:692 [inline]
 __x64_sys_pwrite64+0x151/0x1c0 fs/read_write.c:692
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x415fb7
Code: Bad RIP value.
RSP: 002b:00007f6fd529e9f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000415fb7
RDX: 0000000008100000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000000003 R08: fe03f80fe03f80ff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f6fd529f6d4 R14: 00007f6fd529f9c0 R15: 000000000078bf0c
rcu: rcu_preempt kthread starved for 10502 jiffies! g53845 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:
rcu_preempt     I28912    10      2 0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x7d3/0xc40 kernel/sched/core.c:4178