rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=c12/1/0x4000000000000002 softirq=10817/10817 fqs=2787 
	(t=10500 jiffies g=5949 q=167)
rcu: rcu_preempt kthread starved for 4915 jiffies! g5949 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29032    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 8211 Comm: syz-executor.0 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0xe25/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:free_thread_stack+0x18b/0x590 kernel/fork.c:284
Code: ff ff e8 28 04 00 00 43 80 3c 2e 00 74 08 4c 89 e7 e8 09 a4 69 00 49 8b 1c 24 48 83 c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 <74> 08 48 89 df e8 eb a3 69 00 48 8b 1b e9 82 ff ff ff e8 de 2c 2e
RSP: 0018:ffffc90002347958 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff1101386aa11 RBX: ffff88809c355088 RCX: ffff888098fa6440
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea0002616280
RBP: ffffc90002347990 R08: 000000000003a768 R09: ffffed1015095eaf
R10: ffffed1015095eaf R11: 0000000000000000 R12: ffff88809c355120
R13: dffffc0000000000 R14: 1ffff1101386aa24 R15: ffff8880a84af568
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338
 retint_kernel+0x1b/0x2b
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
RIP: 0010:slab_alloc mm/slab.c:3313 [inline]
RIP: 0010:kmem_cache_alloc+0x1a8/0x2e0 mm/slab.c:3484
Code: 8b 7d d0 57 9d 0f 1f 44 00 00 e8 83 b1 ca ff eb 1e e8 1c af ca ff 48 83 3d 7c 10 59 07 00 0f 84 33 01 00 00 48 8b 7d d0 57 9d <0f> 1f 44 00 00 41 0f 18 0e e9 21 00 00 00 89 d8 c1 e8 08 83 e0 01
RSP: 0000:ffffc90002347ba0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: ffff888098fa6cd4 RBX: 0000000000000cc0 RCX: ffffffff815c0597
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000286
RBP: ffffc90002347bd8 R08: ffff888098fa6c98 R09: fffffbfff13c852d
R10: fffffbfff13c852d R11: 0000000000000000 R12: ffff88821bc46700
R13: ffff8880984b0380 R14: ffff88809281bd90 R15: 0000000000000cc0
 anon_vma_chain_alloc mm/rmap.c:130 [inline]
 __anon_vma_prepare+0x68/0x4c0 mm/rmap.c:184
 anon_vma_prepare include/linux/rmap.h:153 [inline]
 do_anonymous_page+0x1227/0x1610 mm/memory.c:3096
 handle_pte_fault mm/memory.c:3943 [inline]
 __handle_mm_fault mm/memory.c:4075 [inline]
 handle_mm_fault+0x1bce/0x2890 mm/memory.c:4112
 do_user_addr_fault+0x589/0xaf0 arch/x86/mm/fault.c:1441
 __do_page_fault+0xd3/0x1f0 arch/x86/mm/fault.c:1506
 do_page_fault+0x99/0xb0 arch/x86/mm/fault.c:1530
 page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1203
RIP: 0033:0x411e6f
Code: 0f 84 c8 02 00 00 48 83 bd 78 ff ff ff 00 0f 84 f9 04 00 00 48 8b 95 68 ff ff ff 44 89 95 38 ff ff ff 4c 8d ac 10 00 f7 ff ff <49> 89 85 90 06 00 00 49 8d 85 10 03 00 00 49 89 95 98 06 00 00 41
RSP: 002b:00007ffee0518280 EFLAGS: 00010206
RAX: 00007f862c0ea000 RBX: 0000000000020000 RCX: 000000000045a6ca
RDX: 0000000000021000 RSI: 0000000000021000 RDI: 0000000000000000
RBP: 00007ffee0518360 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffee0518450
R13: 00007f862c10a700 R14: 0000000000000000 R15: 000000000075bf2c