rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=256/1/0x4000000000000002 softirq=12743/12743 fqs=7 (t=10501 jiffies g=6613 q=156) rcu: rcu_preempt kthread starved for 10488 jiffies! g6613 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29104 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: 8258 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: __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 RIP: 0010:__memcg_kmem_uncharge+0x219/0x2e0 mm/memcontrol.c:2925 Code: 4b 0d 89 e8 59 97 00 00 bf 01 00 00 00 e8 2f e3 9b ff 65 8b 05 d4 fd 4a 7e 85 c0 74 53 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f <5d> c3 49 8d 5f 10 48 89 df be 08 00 00 00 e8 04 c1 fa ff 48 8b 45 RSP: 0018:ffffc900026c7878 EFLAGS: 00000296 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffffea00025312c0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea00025312c0 RBP: ffffc900026c7878 R08: 000000000003a768 R09: ffffed101520beaf R10: ffffed101520beaf R11: 0000000000000000 R12: ffff8880a14456a0 R13: dffffc0000000000 R14: 1ffff11014288ad4 R15: ffff8880a905f568 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 __kunmap_atomic include/linux/highmem.h:102 [inline] clear_highpage include/linux/highmem.h:215 [inline] kernel_init_free_pages mm/page_alloc.c:1125 [inline] prep_new_page+0x161/0x2e0 mm/page_alloc.c:2171 get_page_from_freelist+0x850/0xaa0 mm/page_alloc.c:3695 __alloc_pages_nodemask+0x264/0x5d0 mm/page_alloc.c:4756 __alloc_pages include/linux/gfp.h:496 [inline] __alloc_pages_node include/linux/gfp.h:509 [inline] alloc_pages_vma+0x94a/0xd50 mm/mempolicy.c:2151 do_huge_pmd_anonymous_page+0x883/0xe50 mm/huge_memory.c:758 create_huge_pmd mm/memory.c:3836 [inline] __handle_mm_fault mm/memory.c:4046 [inline] handle_mm_fault+0x2017/0x2890 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: 0033:0x4418d1 Code: 2e 0f 1f 84 00 00 00 00 00 48 83 fa 20 48 89 f8 73 77 f6 c2 01 74 0b 0f b6 0e 88 0f 48 ff c6 48 ff c7 f6 c2 02 74 12 0f b7 0e <66> 89 0f 48 83 c6 02 48 83 c7 02 0f 1f 40 00 f6 c2 04 74 0c 8b 0e RSP: 002b:00007ffd92b36be8 EFLAGS: 00010202 RAX: 0000000020000080 RBX: 0000000000000000 RCX: 0000000000007865 RDX: 0000000000000006 RSI: 0000000000760020 RDI: 0000000020000080 RBP: 0000000000760000 R08: 0000000000000000 R09: 0000000000000004 R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd92b36dd0 R14: 0000000000760008 R15: 00007ffd92b36de0