rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=aa7/1/0x4000000000000000 softirq=115924/115928 fqs=6 (t=10502 jiffies g=170477 q=207) rcu: rcu_preempt kthread starved for 10490 jiffies! g170477 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: 21974 Comm: syz-executor.2 Not tainted 5.15.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:is_idle_task include/linux/sched.h:1864 [inline] RIP: 0010:irqentry_enter+0x1a/0x50 kernel/entry/common.c:352 Code: 00 e8 1a 02 00 00 eb e2 0f 1f 84 00 00 00 00 00 53 f6 87 88 00 00 00 03 74 07 e8 71 ff ff ff eb 22 65 48 8b 04 25 c0 ef 01 00 <8a> 58 2c 48 8b 7c 24 08 e8 09 f3 ff ff f6 c3 02 75 0b eb 17 e8 5d RSP: 0018:ffffc9000f1ff360 EFLAGS: 00000046 RAX: ffff888087211c80 RBX: ffffc9000f1ff388 RCX: ffffffff8a000e37 RDX: 0000000000000000 RSI: ffffffff8a000bfa RDI: ffffc9000f1ff388 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fc444f40700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000000b5894000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sysvec_apic_timer_interrupt+0xa/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:ffffc9000f1ff430 EFLAGS: 00000086 RAX: 0000000000000000 RBX: ffffffff8a000bf0 RCX: 0000000000040000 RDX: 0000000000000bf0 RSI: 0000000000000001 RDI: ffffffff8a000bf0 RBP: ffffc9000f1ff430 R08: ffffffff8124e123 R09: ffffed101154804d R10: ffffed101154804d R11: 0000000000000000 R12: fffffe0000000ecb R13: dffffc0000000000 R14: ffff88808aa40000 R15: fffffe0000000ec8 handle_interrupt_nmi_irqoff arch/x86/kvm/vmx/vmx.c:6347 [inline] handle_external_interrupt_irqoff+0x1ce/0x410 arch/x86/kvm/vmx/vmx.c:6377 vcpu_enter_guest+0x67b4/0x9650 arch/x86/kvm/x86.c:9701 vcpu_run+0x4d3/0xe50 arch/x86/kvm/x86.c:9819 kvm_arch_vcpu_ioctl_run+0x5c0/0xdb0 arch/x86/kvm/x86.c:10051 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: 0033:0x7fc4479caa39 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:00007fc444f40188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc447addf60 RCX: 00007fc4479caa39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007fc447a24e8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd226a3faf R14: 00007fc444f40300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 21964 Comm: syz-executor.4 Not tainted 5.15.0-rc7-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:__sanitizer_cov_trace_pc+0x42/0x60 kernel/kcov.c:202 Code: ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 64 15 00 00 00 74 2c 8b 91 40 15 00 00 83 fa 02 75 21 48 8b 91 48 15 00 00 48 8b 32 <48> 8d 7e 01 8b 89 44 15 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 RSP: 0018:ffffc9000f1c67f8 EFLAGS: 00000246 RAX: ffffffff81bd53df RBX: 0000000000000000 RCX: ffff888098988000 RDX: ffffc90012279000 RSI: 000000000003ffff RDI: 0000000000000000 RBP: ffffc9000f1c6a30 R08: ffffffff81bd53ce R09: ffffed10173a64a2 R10: ffffed10173a64a2 R11: 0000000000000000 R12: ffff888098988000 R13: dffffc0000000000 R14: ffff8880712a1318 R15: 0000000000000000 handle_mm_fault+0x1cf/0x2560 mm/memory.c:4786 faultin_page mm/gup.c:937 [inline] __get_user_pages+0x4da/0x11f0 mm/gup.c:1158 __get_user_pages_locked mm/gup.c:1343 [inline] get_user_pages_unlocked+0x224/0x8f0 mm/gup.c:2067 hva_to_pfn_slow+0x128/0x510 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2269 hva_to_pfn+0x233/0xbe0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2401 kvm_faultin_pfn+0x366/0x900 arch/x86/kvm/mmu/mmu.c:3942 direct_page_fault+0x11f0/0x2b00 arch/x86/kvm/mmu/mmu.c:3992 kvm_mmu_do_page_fault arch/x86/kvm/mmu.h:127 [inline] kvm_mmu_page_fault+0x1a3/0x13d0 arch/x86/kvm/mmu/mmu.c:5287 vmx_handle_exit+0x26/0x160 arch/x86/kvm/vmx/vmx.c:6055 vcpu_enter_guest+0x6aa9/0x9650 arch/x86/kvm/x86.c:9752 vcpu_run+0x4d3/0xe50 arch/x86/kvm/x86.c:9819 kvm_arch_vcpu_ioctl_run+0x5c0/0xdb0 arch/x86/kvm/x86.c:10051 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: 0033:0x7f9fae783a39 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:00007f9fabcf9188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9fae896f60 RCX: 00007f9fae783a39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f9fae7dde8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe3b2795cf R14: 00007f9fabcf9300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 00 e8 add %ch,%al 2: 1a 02 sbb (%rdx),%al 4: 00 00 add %al,(%rax) 6: eb e2 jmp 0xffffffea 8: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) f: 00 10: 53 push %rbx 11: f6 87 88 00 00 00 03 testb $0x3,0x88(%rdi) 18: 74 07 je 0x21 1a: e8 71 ff ff ff callq 0xffffff90 1f: eb 22 jmp 0x43 21: 65 48 8b 04 25 c0 ef mov %gs:0x1efc0,%rax 28: 01 00 * 2a: 8a 58 2c mov 0x2c(%rax),%bl <-- trapping instruction 2d: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi 32: e8 09 f3 ff ff callq 0xfffff340 37: f6 c3 02 test $0x2,%bl 3a: 75 0b jne 0x47 3c: eb 17 jmp 0x55 3e: e8 .byte 0xe8 3f: 5d pop %rbp