rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=58e/1/0x4000000000000000 softirq=75335/75336 fqs=10 (t=10500 jiffies g=152357 q=72) rcu: rcu_preempt kthread starved for 10479 jiffies! g152357 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29664 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4155 schedule+0xd0/0x2a0 kernel/sched/core.c:4230 schedule_timeout+0x148/0x250 kernel/time/timer.c:1897 rcu_gp_fqs_loop kernel/rcu/tree.c:1856 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2026 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 NMI backtrace for cpu 0 CPU: 0 PID: 10378 Comm: syz-executor.1 Not tainted 5.8.0-rc2-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:320 print_cpu_stall kernel/rcu/tree_stall.h:553 [inline] check_cpu_stall kernel/rcu/tree_stall.h:627 [inline] rcu_pending kernel/rcu/tree.c:3471 [inline] rcu_sched_clock_irq.cold+0x5b3/0xccc kernel/rcu/tree.c:2486 update_process_times+0x25/0x60 kernel/time/timer.c:1726 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x108/0x290 kernel/time/tick-sched.c:1320 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0x128/0x220 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199 Code: c0 50 b5 b4 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d fe 72 cd 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 8b cb 67 f9 65 8b 05 54 bc 1a 78 85 c0 74 02 5d RSP: 0018:ffffc90000007e10 EFLAGS: 00000286 RAX: 1ffffffff13696aa RBX: ffffffff864bd3b0 RCX: 1ffffffff155cb92 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff888043e1ce40 RBP: ffff8880ae6255c0 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90000007e90 R13: 0000000000000000 R14: ffff8880ae6255c0 R15: dffffc0000000000 expire_timers kernel/time/timer.c:1448 [inline] __run_timers.part.0+0x53c/0xa20 kernel/time/timer.c:1773 __run_timers kernel/time/timer.c:1745 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1786 __do_softirq+0x34c/0xa60 kernel/softirq.c:292 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x111/0x170 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:387 [inline] __irq_exit_rcu kernel/softirq.c:417 [inline] irq_exit_rcu+0x229/0x270 kernel/softirq.c:429 sysvec_apic_timer_interrupt+0x12d/0x220 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x8c/0xe0 kernel/locking/spinlock.c:191 Code: 48 c7 c0 40 b5 b4 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 37 48 83 3d ab 6c cd 01 00 74 22 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 45 c5 67 f9 65 8b 05 0e b6 1a 78 RSP: 0018:ffffc9001633fa28 EFLAGS: 00000286 RAX: 1ffffffff13696a8 RBX: 0000000000000286 RCX: 1ffffffff155cb92 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000286 RBP: ffff88804e41ed70 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000286 R14: ffff88804e41ed70 R15: ffff8880ae635e00 try_to_wake_up+0x602/0x1440 kernel/sched/core.c:2642 wake_up_process kernel/sched/core.c:2710 [inline] wake_up_q+0x96/0x100 kernel/sched/core.c:498 futex_wake+0x3e9/0x490 kernel/futex.c:1642 do_futex+0x322/0x1a60 kernel/futex.c:3816 __do_sys_futex kernel/futex.c:3872 [inline] __se_sys_futex kernel/futex.c:3840 [inline] __x64_sys_futex+0x378/0x4e0 kernel/futex.c:3840 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cb19 Code: Bad RIP value. RSP: 002b:00007f2a817a3cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000078bf08 RCX: 000000000045cb19 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000078bf0c RBP: 000000000078bf00 R08: 0000000000000016 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000078bf0c R13: 0000000000c9fb6f R14: 00007f2a817a49c0 R15: 000000000078bf0c