syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=862/1/0x4000000000000002 softirq=11027/11027 fqs=0 
	(t=10501 jiffies g=6441 q=71)
rcu: rcu_preempt kthread starved for 10502 jiffies! g6441 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: 8180 Comm: udevd 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:mod_memcg_page_state+0x161/0x190 include/linux/memcontrol.h:655
Code: 3c 20 00 74 0c 48 c7 c7 28 96 0a 89 e8 a8 9e 69 00 48 83 3d c8 21 c2 07 00 74 2d e8 99 27 2e 00 4c 89 ff 57 9d 0f 1f 44 00 00 <5b> 41 5c 41 5e 41 5f 5d c3 e8 81 27 2e 00 0f 0b e8 7a 27 2e 00 0f
RSP: 0000:ffffc90002087ae8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81487433 RBX: 0000000000000000 RCX: ffff8880a8060600
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea00022edb00
RBP: ffffc90002087b08 R08: 000000000003a768 R09: ffffed10126efb47
R10: ffffed10126efb47 R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff88809377da28
 free_thread_stack+0x168/0x590 kernel/fork.c:280
 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:check_memory_region_inline mm/kasan/generic.c:173 [inline]
RIP: 0010:check_memory_region+0xf/0x2e0 mm/kasan/generic.c:192
Code: 88 4c 89 fe 31 c0 e8 03 8b ad ff eb cf cc cc cc cc cc cc cc cc cc cc cc cc cc cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 b0 01 <48> 85 f6 0f 84 fd 01 00 00 48 89 fb 48 c1 eb 2f 48 81 fb fe ff 01
RSP: 0000:ffffc90002087d68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff8880a8060601 RBX: 0000000000000001 RCX: ffffffff815ae658
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8880a84354b0
RBP: ffffc90002087d90 R08: dffffc0000000000 R09: fffff52000410fbd
R10: fffff52000410fbd R11: 0000000000000000 R12: ffff8880a84354b0
R13: ffff8880a84354b8 R14: 1ffff92000410fbc R15: ffffc90002087de0
 __kasan_check_write+0x14/0x20 mm/kasan/common.c:100
 atomic64_add_return include/asm-generic/atomic-instrumented.h:881 [inline]
 atomic_long_add_return_release include/asm-generic/atomic-long.h:70 [inline]
 __up_read+0x238/0x740 kernel/locking/rwsem.c:1437
 up_read+0x1d/0x20 kernel/locking/rwsem.c:1577
 do_user_addr_fault+0x5ba/0xaf0 arch/x86/mm/fault.c:1467
 __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: 0033:0x7fb86604e317
Code: 24 30 48 8b 40 08 48 89 44 24 70 48 8b 86 f8 02 00 00 48 85 c0 0f 84 fc 04 00 00 8b 96 f0 02 00 00 8b 8e f4 02 00 00 44 21 c2 <48> 8b 14 d0 4c 89 e8 48 d3 e8 48 89 c1 83 e1 3f 48 89 d0 48 d3 e8
RSP: 002b:00007ffd59c1ac20 EFLAGS: 00010202
RAX: 00007fb865c1d290 RBX: 00007fb86625c050 RCX: 0000000000000009
RDX: 0000000000000007 RSI: 00007fb8662639b0 RDI: 0000000000401790
RBP: 0000000000000002 R08: 0000000003f0b27f R09: 0000000000000005
R10: 0000000000000008 R11: 00007ffd59c1ac70 R12: 0000000000000007
R13: 00000000fc2c9fc5 R14: 0000000000000000 R15: 00007ffd59c1adf8