rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=c0e/1/0x4000000000000004 softirq=138784/138796 fqs=0 rcu: (t=10500 jiffies g=199021 q=331) rcu: rcu_preempt kthread starved for 10500 jiffies! g199021 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I29208 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3515 schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x4d8/0xef0 kernel/time/timer.c:1806 rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202 kthread+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 NMI backtrace for cpu 1 CPU: 1 PID: 7158 Comm: syz-executor.2 Not tainted 4.19.133-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+0x1fc/0x2fe lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15f/0x19c kernel/rcu/tree.c:1340 print_cpu_stall kernel/rcu/tree.c:1478 [inline] check_cpu_stall kernel/rcu/tree.c:1550 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0x62d/0xe19 kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 kernel/time/timer.c:1638 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168 tick_sched_timer+0xfc/0x290 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1401 [inline] __hrtimer_run_queues+0x3f6/0xe60 kernel/time/hrtimer.c:1463 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1521 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa3/0xe0 kernel/locking/spinlock.c:184 Code: 48 c7 c0 48 5b d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 2f 48 83 3d 1c 82 98 01 00 74 15 48 89 df 57 9d <0f> 1f 44 00 00 eb b2 e8 ba 85 c6 f9 eb c0 0f 0b 0f 0b 48 c7 c7 48 RSP: 0018:ffff8880ae707c20 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a4b69 RBX: 0000000000000282 RCX: 1ffff110126159b5 RDX: dffffc0000000000 RSI: ffff8880930acd88 RDI: 0000000000000282 RBP: ffff8880ae723a40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000023a40 R14: 0000000000000000 R15: ffff8880ae723a40 __mod_timer kernel/time/timer.c:1059 [inline] mod_timer+0x4ec/0xf30 kernel/time/timer.c:1102 call_timer_fn+0x177/0x700 kernel/time/timer.c:1326 expire_timers+0x243/0x4e0 kernel/time/timer.c:1363 __run_timers kernel/time/timer.c:1684 [inline] run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1697 __do_softirq+0x26c/0x9a0 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:544 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa3/0xe0 kernel/locking/spinlock.c:184 Code: 48 c7 c0 48 5b d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 2f 48 83 3d 1c 82 98 01 00 74 15 48 89 df 57 9d <0f> 1f 44 00 00 eb b2 e8 ba 85 c6 f9 eb c0 0f 0b 0f 0b 48 c7 c7 48 RSP: 0018:ffff8881ea63f8b8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a4b69 RBX: 0000000000000282 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffffffff8ba49b48 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dead000000000200 R13: ffff888090316000 R14: 0000000000000007 R15: dffffc0000000000 __debug_check_no_obj_freed lib/debugobjects.c:798 [inline] debug_check_no_obj_freed+0x201/0x482 lib/debugobjects.c:817 free_pages_prepare mm/page_alloc.c:1055 [inline] free_pcp_prepare mm/page_alloc.c:1069 [inline] free_unref_page_prepare+0x1ea/0x5d0 mm/page_alloc.c:2757 free_unref_page+0x20/0x170 mm/page_alloc.c:2806 __vunmap+0x21b/0x3f0 mm/vmalloc.c:1531 vfree+0x65/0x100 mm/vmalloc.c:1598 kcov_put kernel/kcov.c:237 [inline] kcov_put+0x1f/0x30 kernel/kcov.c:234 kcov_close+0xc/0x10 kernel/kcov.c:323 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbb2/0x2b70 kernel/exit.c:887 do_group_exit+0x125/0x310 kernel/exit.c:990 get_signal+0x3f2/0x1f70 kernel/signal.c:2588 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:821 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c1d9 Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8 RSP: 002b:00007f928e319cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000078bf08 RCX: 000000000045c1d9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078bf08 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffccb1c8b9f R14: 00007f928e31a9c0 R15: 000000000078bf0c