rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=f36/1/0x4000000000000000 softirq=145376/145377 fqs=14 (t=10500 jiffies g=278069 q=138) rcu: rcu_preempt kthread starved for 10470 jiffies! g278069 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 I28864 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3445 [inline] __schedule+0x8b4/0x1e80 kernel/sched/core.c:4169 schedule+0xd0/0x2a0 kernel/sched/core.c:4244 schedule_timeout+0x148/0x250 kernel/time/timer.c:1897 rcu_gp_fqs_loop kernel/rcu/tree.c:1870 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2040 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 NMI backtrace for cpu 0 CPU: 0 PID: 9872 Comm: syz-executor.3 Not tainted 5.8.0-rc3-next-20200703-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:165 [inline] rcu_dump_cpu_stacks+0x194/0x1cf kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3624 [inline] rcu_sched_clock_irq.cold+0x5b3/0xcbd kernel/rcu/tree.c:2508 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:1328 __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+0x4f/0x120 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 10 ff 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 ee 7a c8 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 db 01 63 f9 65 8b 05 44 7a 15 78 85 c0 74 02 5d RSP: 0018:ffffc90000007e10 EFLAGS: 00000286 RAX: 1ffffffff1369fe2 RBX: ffffffff86505f10 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff87ec83ff RBP: ffff8880ae6255c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 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:706 __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+0x54/0x120 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:seqcount_lockdep_reader_access include/linux/seqlock.h:99 [inline] RIP: 0010:read_seqcount_begin.constprop.0+0x110/0x1f0 include/linux/seqlock.h:182 Code: 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 d0 00 00 00 48 83 3d b0 71 50 08 00 0f 84 92 00 00 00 e8 a5 79 0f 00 48 89 df 57 9d <0f> 1f 44 00 00 e8 96 79 0f 00 44 8b 25 4f ac 58 08 31 ff 44 89 e3 RSP: 0018:ffffc900089a7d98 EFLAGS: 00000216 RAX: 0000000000000051 RBX: 0000000000000216 RCX: ffffc9001003d000 RDX: 0000000000040000 RSI: ffffffff81648d5b RDI: 0000000000000216 RBP: 0000000000000200 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 00007ff891b60c60 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000 ktime_get_ts64+0x50/0x210 kernel/time/timekeeping.c:890 posix_get_monotonic_timespec+0x6c/0x250 kernel/time/posix-timers.c:199 __do_sys_clock_gettime kernel/time/posix-timers.c:1092 [inline] __se_sys_clock_gettime kernel/time/posix-timers.c:1082 [inline] __x64_sys_clock_gettime+0x149/0x240 kernel/time/posix-timers.c:1082 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:367 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45f96a Code: Bad RIP value. RSP: 002b:00007ff891b60c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e4 RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 000000000045f96a RDX: 0000000000000028 RSI: 00007ff891b60c60 RDI: 0000000000000001 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016 R13: 0000000000023a00 R14: 00000000004cbce6 R15: 00007ff891b616d4