rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=416/1/0x4000000000000002 softirq=13129/13129 fqs=13 (t=10501 jiffies g=6745 q=414) rcu: rcu_preempt kthread starved for 10475 jiffies! g6745 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: 8532 Comm: syz-executor.1 Not tainted 5.5.0-rc5-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: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 RIP: 0010:__memcg_kmem_uncharge+0xd/0x1a0 mm/memcontrol.c:2908 Code: 81 c3 08 02 00 00 48 89 df 4c 89 f6 e8 8c 85 ff ff 5b 41 5e 5d c3 0f 1f 80 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 <50> 89 f3 49 89 fc 48 b8 00 00 00 00 00 fc ff df 4c 8d 77 38 4d 89 RSP: 0018:ffffc900020c7bc0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81489244 RBX: ffffea0002511440 RCX: ffff888099b42500 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0002511440 RBP: ffffc900020c7be8 R08: dffffc0000000000 R09: fffffbfff124248a R10: fffffbfff124248a R11: 0000000000000000 R12: ffff8880a8b8a320 R13: dffffc0000000000 R14: 1ffff11015171464 R15: ffff8880a64ed6f8 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_irq+0xc1/0x140 kernel/sched/core.c:4338 retint_kernel+0x1b/0x2b RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:762 [inline] RIP: 0010:do_user_addr_fault+0x20c/0xaf0 arch/x86/mm/fault.c:1338 Code: 08 00 74 0c 48 c7 c7 78 95 2a 89 e8 ce 8a 7d 00 48 83 3d 6e f9 f4 07 00 0f 84 db 08 00 00 e8 6b 22 41 00 fb 66 0f 1f 44 00 00 <48> 89 e0 bb 54 00 00 00 e9 a1 00 00 00 49 8d 9d 90 00 00 00 48 89 RSP: 0000:ffffc900020c7e48 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81359c15 RBX: 0000000000000003 RCX: ffff888099b42500 RDX: 0000000000000000 RSI: ffffffff813592b3 RDI: ffff888099b42d44 RBP: ffffc900020c7ee0 R08: ffff888099b42d58 R09: fffff52000419000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffc900020c7f58 R14: ffffc900020c7fe0 R15: 1ffff92000418ffc __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: 0033:0x40ff30 Code: 31 c6 44 8d 4f 04 41 89 f8 8d 1c f6 89 d8 c1 e8 04 31 c3 69 c3 2d eb d4 27 89 c3 c1 eb 0f 31 c3 89 f8 89 c6 81 e6 ff 1f 00 00 <8b> 14 b5 00 00 73 00 41 39 d0 74 23 85 d2 74 58 83 c0 01 41 39 c1 RSP: 002b:00007ffd8b10b080 EFLAGS: 00010206 RAX: 00000000817c69ff RBX: 000000004e0fefea RCX: 0000001b30e20000 RDX: 0000000000000484 RSI: 00000000000009ff RDI: ffffffff817c69ff RBP: 0000000000000000 R08: 00000000817c69ff R09: 00000000817c6a03 R10: 00007ffd8b10b220 R11: 0000000000000246 R12: 000000000075bfa8 R13: 0000000080000000 R14: 00007ff5f809b008 R15: 0000000000000000