rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=3da/1/0x4000000000000000 softirq=189518/189518 fqs=2 (t=10500 jiffies g=359493 q=37) rcu: rcu_preempt kthread starved for 10496 jiffies! g359493 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: task:rcu_preempt state:R running task stack:29096 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0xec9/0x2280 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline] rcu_gp_kthread+0xb2c/0x1ca0 kernel/rcu/tree.c:2058 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: 6564 Comm: syz-executor.5 Not tainted 5.9.0-rc6-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+0x198/0x1fd 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+0x1e3/0x21e 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:3637 [inline] rcu_sched_clock_irq.cold+0x4db/0xdfd kernel/rcu/tree.c:2519 update_process_times+0x25/0xa0 kernel/time/timer.c:1710 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x147/0x5f0 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0x4c/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:lock_acquire+0x27b/0xaf0 kernel/locking/lockdep.c:5032 Code: ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 1d 07 00 00 48 83 3d d8 60 a0 08 00 0f 84 73 05 00 00 4c 89 ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 08 48 c7 RSP: 0018:ffffc90000007c28 EFLAGS: 00000286 RAX: 1ffffffff13f8d75 RBX: ffff8880250e2000 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffffc90000007d68 R08: 0000000000000000 R09: ffffffff8d0b7aaf R10: fffffbfff1a16f55 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000286 call_timer_fn+0x12e/0x760 kernel/time/timer.c:1410 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1768 __do_softirq+0x1f8/0xb23 kernel/softirq.c:298 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+0x9d/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x235/0x280 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x4/0x20 kernel/kcov.c:284 Code: 84 00 00 00 00 00 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 cc fe ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 ae fe ff ff 0f 1f 40 00 66 2e 0f 1f RSP: 0018:ffffc90015e779b0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90015e77ad8 RCX: ffffffff816a88c1 RDX: 0000000000040000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: fffff52002bcef5b R08: 0000000000000001 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000000 R12: 000000000118cf48 R13: 0000000000000000 R14: ffffc90015e77ba0 R15: 0000000000000000 futex_wait_setup+0x171/0x2d0 kernel/futex.c:2644 futex_wait+0x1b5/0x560 kernel/futex.c:2685 do_futex+0x15b/0x1a50 kernel/futex.c:3749 __do_sys_futex kernel/futex.c:3810 [inline] __se_sys_futex kernel/futex.c:3778 [inline] __x64_sys_futex+0x378/0x4e0 kernel/futex.c:3778 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e179 Code: 3d b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fdc72376cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000118cf48 RCX: 000000000045e179 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118cf48 RBP: 000000000118cf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffebd640c4f R14: 00007fdc723779c0 R15: 000000000118cf4c