rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=43d/1/0x4000000000000000 softirq=128631/128631 fqs=8 (t=10502 jiffies g=223461 q=280) rcu: rcu_preempt kthread starved for 10486 jiffies! g223461 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: task:rcu_preempt state:R running task stack:26544 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6287 schedule+0x14b/0x210 kernel/sched/core.c:6366 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x1fd/0x770 kernel/rcu/tree.c:1957 rcu_gp_kthread+0xa5/0x350 kernel/rcu/tree.c:2130 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 24595 Comm: syz-executor.4 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__rcu_read_unlock+0x0/0x630 kernel/rcu/tree_plugin.h:415 Code: 60 00 eb b2 44 89 f9 80 e1 07 80 c1 03 38 c1 7c b0 4c 89 ff e8 a1 20 60 00 eb a6 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 00 RSP: 0018:ffffc90000007840 EFLAGS: 00000046 RAX: ffffffff81566c08 RBX: 0000000000000379 RCX: ffff88802e409c80 RDX: 0000000080010001 RSI: 0000000000000004 RDI: ffff8880b9c32508 RBP: ffff88804488c5e8 R08: dffffc0000000000 R09: ffffed10173864a2 R10: ffffed10173864a2 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888082fd1760 R14: ffff888040d3e318 R15: ffff88804488c500 FS: 00007f058ae78700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000003a0d8000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:719 [inline] __task_pid_nr_ns+0x31e/0x3c0 kernel/pid.c:501 perf_event_pid_type kernel/events/core.c:1409 [inline] perf_event_tid kernel/events/core.c:1423 [inline] __perf_event_header__init_id+0x1de/0x500 kernel/events/core.c:6809 perf_prepare_sample+0x10b/0x1770 kernel/events/core.c:7309 __perf_event_output kernel/events/core.c:7487 [inline] perf_event_output_forward+0x176/0x2c0 kernel/events/core.c:7507 __perf_event_overflow+0x1f8/0x380 kernel/events/core.c:9177 perf_swevent_hrtimer+0x3d1/0x530 kernel/events/core.c:10567 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:vmx_do_interrupt_nmi_irqoff+0x10/0x20 Code: 41 5b 41 5a 41 59 41 58 5e 5f 5a 59 58 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 55 48 89 e5 48 83 e4 f0 6a 18 55 9c 6a 10 ff d7 <48> 89 ec 5d c3 cc cc cc cc cc cc cc cc cc cc cc 55 41 56 53 48 89 RSP: 0018:ffffc90005897430 EFLAGS: 00000086 RAX: 0000000000000000 RBX: ffffffff8a000bf0 RCX: 0000000000040000 RDX: 0000000000000bf0 RSI: 0000000000000001 RDI: ffffffff8a000bf0 RBP: ffffc90005897430 R08: ffffffff8124c033 R09: ffffed10148b504d R10: ffffed10148b504d R11: 0000000000000000 R12: fffffe0000000ecb R13: dffffc0000000000 R14: ffff8880a45a8000 R15: fffffe0000000ec8 handle_interrupt_nmi_irqoff arch/x86/kvm/vmx/vmx.c:6352 [inline] handle_external_interrupt_irqoff+0x1ce/0x410 arch/x86/kvm/vmx/vmx.c:6382 vcpu_enter_guest+0x651e/0x96b0 arch/x86/kvm/x86.c:9684 vcpu_run+0x4d3/0xe50 arch/x86/kvm/x86.c:9802 kvm_arch_vcpu_ioctl_run+0x5c0/0xdb0 arch/x86/kvm/x86.c:10034 kvm_vcpu_ioctl+0x894/0xe20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3779 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f058d902a39 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f058ae78188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f058da05f60 RCX: 00007f058d902a39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f058d95cc5f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffccdd5542f R14: 00007f058ae78300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 24584 Comm: syz-executor.5 Not tainted 5.15.0-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:88 [inline] dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x22d/0x390 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq+0x1e33/0x2bc0 kernel/rcu/tree.c:2599 update_process_times+0x197/0x200 kernel/time/timer.c:1785 tick_sched_handle kernel/time/tick-sched.c:226 [inline] tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:vcpu_enter_guest+0x653f/0x96b0 arch/x86/kvm/x86.c:9695 Code: 00 4c 89 ff e8 f2 6a 12 00 48 c7 c7 00 7a 43 8a e8 c6 aa e8 08 65 4c 89 3d 86 10 f0 7e e8 39 36 78 00 fb 49 8d 9f e0 20 00 00 <48> 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 2b 28 bd 00 RSP: 0018:ffffc9000558f480 EFLAGS: 00000282 RAX: ce28eb088dd8f400 RBX: ffff88808ebd20e0 RCX: ffffffff81659711 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000558fb88 R08: dffffc0000000000 R09: fffffbfff1fa37fb R10: fffffbfff1fa37fb R11: 0000000000000000 R12: dffffc0000000000 R13: 00000035dd6cc178 R14: ffffc9000558f5c0 R15: ffff88808ebd0000 vcpu_run+0x4d3/0xe50 arch/x86/kvm/x86.c:9802 kvm_arch_vcpu_ioctl_run+0x5c0/0xdb0 arch/x86/kvm/x86.c:10034 kvm_vcpu_ioctl+0x894/0xe20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3779 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f3956f50a39 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f39544c6188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f3957053f60 RCX: 00007f3956f50a39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f3956faac5f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff77564aaf R14: 00007f39544c6300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 eb add %ch,%bl 2: b2 44 mov $0x44,%dl 4: 89 f9 mov %edi,%ecx 6: 80 e1 07 and $0x7,%cl 9: 80 c1 03 add $0x3,%cl c: 38 c1 cmp %al,%cl e: 7c b0 jl 0xffffffc0 10: 4c 89 ff mov %r15,%rdi 13: e8 a1 20 60 00 callq 0x6020b9 18: eb a6 jmp 0xffffffc0 1a: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 21: 00 00 00 24: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) * 29: 55 push %rbp <-- trapping instruction 2a: 48 89 e5 mov %rsp,%rbp 2d: 41 57 push %r15 2f: 41 56 push %r14 31: 41 55 push %r13 33: 41 54 push %r12 35: 53 push %rbx 36: 48 83 e4 e0 and $0xffffffffffffffe0,%rsp 3a: 48 rex.W 3b: 81 .byte 0x81 3c: ec in (%dx),%al 3d: c0 .byte 0xc0