rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=0d2/1/0x4000000000000002 softirq=11505/11505 fqs=148 
	(t=10501 jiffies g=6517 q=294)
rcu: rcu_preempt kthread starved for 10206 jiffies! g6517 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: 8167 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: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:__memcg_kmem_uncharge+0x44/0x1a0 mm/memcontrol.c:2913
Code: fc ff df 4c 8d 77 38 4d 89 f5 49 c1 ed 03 41 80 7c 05 00 00 74 08 4c 89 f7 e8 78 fe fa ff 4d 8b 3e b8 01 00 00 00 89 d9 d3 e0 <4d> 85 ff 0f 84 de 00 00 00 4c 39 3d a4 f0 8c 07 0f 84 2c 01 00 00
RSP: 0018:ffffc90001fa7480 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffffc90002019000 RSI: 0000000000000000 RDI: ffffea0002a3fb80
RBP: ffffc90001fa74b0 R08: 000000000003a728 R09: ffffed1012444f3f
R10: ffffed1012444f3f R11: 0000000000000000 R12: ffffea0002a3fb80
R13: 1ffffd4000547f77 R14: ffffea0002a3fbb8 R15: 0000000000000000
 memcg_kmem_uncharge include/linux/memcontrol.h:1402 [inline]
 free_thread_stack+0x12e/0x590 kernel/fork.c:284
 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_common kernel/sched/core.c:4236 [inline]
 preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261
 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
 _raw_spin_unlock_irq+0x77/0x80 kernel/locking/spinlock.c:199
 spin_unlock_irq include/linux/spinlock.h:388 [inline]
 shmem_add_to_page_cache+0xe67/0x1290 mm/shmem.c:647
 shmem_getpage_gfp+0x1425/0x2f80 mm/shmem.c:1876
 shmem_fault+0x284/0x7f0 mm/shmem.c:2067
 __do_fault+0x144/0x3d0 mm/memory.c:3188
 do_read_fault+0x58a/0x9e0 mm/memory.c:3585
 do_fault mm/memory.c:3714 [inline]
 handle_pte_fault mm/memory.c:3945 [inline]
 __handle_mm_fault mm/memory.c:4075 [inline]
 handle_mm_fault+0x1bb8/0x2890 mm/memory.c:4112
 faultin_page mm/gup.c:640 [inline]
 __get_user_pages+0x1002/0x1610 mm/gup.c:851
 populate_vma_page_range+0x1fd/0x250 mm/gup.c:1235
 __mm_populate+0x278/0x3d0 mm/gup.c:1283
 mm_populate include/linux/mm.h:2347 [inline]
 vm_mmap_pgoff+0x1a0/0x1d0 mm/util.c:511
 ksys_mmap_pgoff+0x104/0x560 mm/mmap.c:1607
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
 __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:91
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a679
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f39959f8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045a679
RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000000020000000
RBP: 000000000075bf20 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 00007f39959f96d4
R13: 00000000004c7861 R14: 00000000004de5a8 R15: 00000000ffffffff