rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=2de/1/0x4000000000000000 softirq=68912/68913 fqs=2 (t=30002 jiffies g=113433 q=57966) rcu: rcu_preempt kthread starved for 30002 jiffies! g113433 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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 28896 10 2 0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1916 rcu_gp_fqs_loop kernel/rcu/tree.c:1887 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2057 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 NMI backtrace for cpu 1 CPU: 1 PID: 1350 Comm: syz-executor.5 Not tainted 5.8.0-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: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:3635 [inline] rcu_sched_clock_irq.cold+0x5b3/0xccd kernel/rcu/tree.c:2518 update_process_times+0x25/0xa0 kernel/time/timer.c:1738 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: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+0x4c/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:592 RIP: 0010:__do_softirq+0x1c2/0xa24 kernel/softirq.c:284 Code: c7 c0 98 fd b4 89 48 c1 e8 03 42 80 3c 30 00 0f 85 b9 07 00 00 48 83 3d e3 fb 94 01 00 0f 84 6f 06 00 00 fb 66 0f 1f 44 00 00 <48> c7 44 24 08 c0 90 a0 89 b8 ff ff ff ff 0f bc 04 24 83 c0 01 89 RSP: 0018:ffffc90000da8f70 EFLAGS: 00000282 RAX: 1ffffffff1369fb3 RBX: ffff888053dae540 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff88200197 RBP: ffffc90005e1fab8 R08: 0000000000000001 R09: ffffffff8c5acb77 R10: fffffbfff18b596e R11: 0000000000000001 R12: ffff88809ff3b000 R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff815eb4c0 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+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+0x1f3/0x230 kernel/softirq.c:435 common_interrupt+0xa3/0x1f0 arch/x86/kernel/irq.c:239 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:583 RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:207 [inline] RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:111 [inline] RIP: 0010:kvm_test_request include/linux/kvm_host.h:1253 [inline] RIP: 0010:kvm_check_request include/linux/kvm_host.h:1263 [inline] RIP: 0010:vcpu_enter_guest+0x52d/0x3b20 arch/x86/kvm/x86.c:8359 Code: 11 00 00 e8 45 e2 64 00 be 08 00 00 00 4c 89 ef e8 88 2e a4 00 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 93 2f 00 00 4d 8b 74 24 38 31 ff 49 c1 ee 09 41 83 e6 01 44 RSP: 0018:ffffc90005e1fbd0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff810f27d8 RDX: 1ffff1100767887f RSI: 0000000000000008 RDI: ffff88803b3c43f8 RBP: ffffc90005e1fcd0 R08: 0000000000000000 R09: ffff88803b3c43ff R10: ffffed100767887f R11: 0000000000000000 R12: ffff88803b3c43c0 R13: ffff88803b3c43f8 R14: 0000000000000000 R15: ffff88803b3c44b0 vcpu_run arch/x86/kvm/x86.c:8664 [inline] kvm_arch_vcpu_ioctl_run+0x4b7/0x1840 arch/x86/kvm/x86.c:8885 kvm_vcpu_ioctl+0x467/0xdf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3166 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cce9 Code: 2d b6 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f700e8cac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000010a80 RCX: 000000000045cce9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007fff3bca246f R14: 00007f700e8cb9c0 R15: 000000000078bf0c