syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=6c6/1/0x4000000000000002 softirq=10646/10647 fqs=11 
	(t=10501 jiffies g=6937 q=411)
rcu: rcu_preempt kthread starved for 10480 jiffies! g6937 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    28984    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: 8567 Comm: syz-executor.0 Not tainted 5.5.0-rc5-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:1517 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641
 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:mod_memcg_page_state+0x0/0x190 include/linux/memcontrol.h:652
Code: 48 8b 3b e8 32 7e 60 00 eb 0c e8 eb 27 2e 00 eb 05 e8 e4 27 2e 00 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 44 00 00 <55> 48 89 e5 41 57 41 56 41 54 53 41 89 f6 48 89 fb e8 ba 27 2e 00
RSP: 0018:ffffc900022278c0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff110121ac9d1 RBX: ffff888090d64e88 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea00022f2800
RBP: ffffc90002227900 R08: dffffc0000000000 R09: fffffbfff124248a
R10: fffffbfff124248a R11: 0000000000000000 R12: ffff888090d64f20
R13: dffffc0000000000 R14: 1ffff110121ac9e4 R15: ffff888095a57438
 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:debug_lockdep_rcu_enabled+0x4/0xe0 kernel/rcu/update.c:250
Code: 38 c1 7c e3 48 c7 c7 04 29 a3 89 e8 46 df 4f 00 eb d5 0f 1f 40 00 55 48 89 e5 e8 a7 b7 00 00 e8 a2 b8 00 00 5d c3 55 48 89 e5 <41> 57 41 56 53 48 c7 c0 5c b2 64 89 48 c1 e8 03 49 bf 00 00 00 00
RSP: 0000:ffffc90002227b18 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81a4a3e5 RBX: 00000000000001ba RCX: ffff88809ed320c0
RDX: 0000000000000000 RSI: 0000000000001212 RDI: ffffffff88e5598d
RBP: ffffc90002227b18 R08: ffffffff81a4a47f R09: ffff88808d40e6a8
R10: ffffed1011a81cd7 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000180 R14: ffff88809ed334a8 R15: ffff888069bbb000
 ___might_sleep+0x20/0x5e0 kernel/sched/core.c:6765
 process_huge_page mm/memory.c:4626 [inline]
 clear_huge_page+0x220/0x8a0 mm/memory.c:4687
 __do_huge_pmd_anonymous_page+0x21a/0x1010 mm/huge_memory.c:596
 do_huge_pmd_anonymous_page+0x91a/0xe50 mm/huge_memory.c:764
 create_huge_pmd mm/memory.c:3888 [inline]
 __handle_mm_fault mm/memory.c:4098 [inline]
 handle_mm_fault+0x2017/0x2890 mm/memory.c:4164
 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: 0033:0x4005c0
Code: 01 e9 cd 01 00 00 48 8b 44 24 10 48 0b 44 24 28 75 20 48 8b 14 24 48 8b 7c 24 20 be 02 00 00 00 e8 a5 55 00 00 48 8b 4c 24 08 <66> 89 01 e9 a1 01 00 00 48 8b 44 24 08 48 8b 14 24 be 02 00 00 00
RSP: 002b:00007ffc073c5d20 EFLAGS: 00010206
RAX: 000000000000000a RBX: 000000000075c9a0 RCX: 00000000208c0000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 000000000000000a
RBP: 00000000007602f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffc073c5e30 R11: 0000000000000246 R12: 000000000075bf20
R13: 00000000000102c6 R14: 00000000007602f8 R15: 000000000075bf2c