rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=103/1/0x4000000000000000 softirq=14975/14976 fqs=12 (t=10500 jiffies g=20897 q=468) rcu: rcu_preempt kthread starved for 10470 jiffies! g20897 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:28952 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10234 Comm: syz-executor.3 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode+0x31/0x40 kernel/kcov.c:175 Code: 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 64 15 00 00 85 d2 74 0b 8b 86 40 15 00 00 39 f8 0f 94 c0 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 31 c0 65 8b 15 77 d4 RSP: 0018:ffffc90000fd8e90 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 694ee8e5d585680e RCX: 000000721cbfe6df RDX: 0000000000000000 RSI: ffff88807d748180 RDI: 0000000000000003 RBP: 0000000000000000 R08: 694ee8e5d585680e R09: 0000000000000000 R10: ffffffff816598ea R11: 0000000000000000 R12: ffff88807dec1000 R13: ffff8880b9d223c0 R14: 000000721cbfe6df R15: dffffc0000000000 FS: 00007f83788f6700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007002b000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_cmp8+0x1d/0x70 kernel/kcov.c:264 __hrtimer_next_event_base+0x13a/0x260 kernel/time/hrtimer.c:525 __hrtimer_get_next_event kernel/time/hrtimer.c:587 [inline] hrtimer_update_next_event+0xcd/0x2a0 kernel/time/hrtimer.c:612 hrtimer_interrupt+0x324/0x790 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:vmx_do_interrupt_nmi_irqoff+0x10/0x20 arch/x86/kvm/vmx/vmenter.S:327 Code: 41 5b 41 5a 41 59 41 58 5e 5f 5a 59 58 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 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 41 57 48 8d 47 08 RSP: 0018:ffffc9000bcffb48 EFLAGS: 00000082 RAX: 0000000000000001 RBX: ffff88807520c180 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff89400bf0 RBP: ffffc9000bcffb48 R08: 0000000080000000 R09: ffff88807520c3e7 R10: ffffffff811ea28c R11: 0000000000000000 R12: 0000000000000bf0 R13: 0000000089400000 R14: 0000000000000000 R15: ffff88807520c1b0 handle_interrupt_nmi_irqoff arch/x86/kvm/vmx/vmx.c:6347 [inline] handle_external_interrupt_irqoff arch/x86/kvm/vmx/vmx.c:6377 [inline] vmx_handle_exit_irqoff arch/x86/kvm/vmx/vmx.c:6388 [inline] vmx_handle_exit_irqoff+0x4d2/0x750 arch/x86/kvm/vmx/vmx.c:6380 vcpu_enter_guest+0x2698/0x4410 arch/x86/kvm/x86.c:9701 vcpu_run arch/x86/kvm/x86.c:9819 [inline] kvm_arch_vcpu_ioctl_run+0x47c/0x1b10 arch/x86/kvm/x86.c:10051 kvm_vcpu_ioctl+0x570/0xf30 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 fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f837b380a39 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:00007f83788f6188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f837b483f60 RCX: 00007f837b380a39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f837b3dae8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdebaffb1f R14: 00007f83788f6300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 10223 Comm: syz-executor.1 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+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 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.cold+0x9d/0x746 kernel/rcu/tree.c:2599 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x4c/0x60 kernel/kcov.c:202 Code: 0e 85 c9 74 35 8b 82 64 15 00 00 85 c0 74 2b 8b 82 40 15 00 00 83 f8 02 75 20 48 8b 8a 48 15 00 00 8b 92 44 15 00 00 48 8b 01 <48> 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 c3 0f 1f 00 41 55 RSP: 0018:ffffc9000bc87338 EFLAGS: 00000246 RAX: 000000000003ffff RBX: 0000000000000000 RCX: ffffc9000ae91000 RDX: 0000000000040000 RSI: ffffffff81aa6c40 RDI: 0000000000000003 RBP: ffffc9000bc87498 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81aa6c32 R11: 0000000000000000 R12: 0000000020002000 R13: ffffc9000bc87598 R14: 0000000020001000 R15: 0000000000000000 lockless_pages_from_mm mm/gup.c:2666 [inline] internal_get_user_pages_fast+0x230/0x2560 mm/gup.c:2727 get_user_pages_fast_only+0x2b/0x40 mm/gup.c:2781 get_user_page_fast_only include/linux/mm.h:1913 [inline] hva_to_pfn_fast arch/x86/kvm/../../../virt/kvm/kvm_main.c:2237 [inline] hva_to_pfn+0xf1/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2395 __gfn_to_pfn_memslot+0x229/0x420 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2460 kvm_faultin_pfn+0x171/0xbc0 arch/x86/kvm/mmu/mmu.c:3942 direct_page_fault+0xd22/0x2320 arch/x86/kvm/mmu/mmu.c:3992 kvm_mmu_do_page_fault arch/x86/kvm/mmu.h:127 [inline] kvm_mmu_page_fault+0x17e/0x17f0 arch/x86/kvm/mmu/mmu.c:5287 handle_ept_violation+0x29c/0x6e0 arch/x86/kvm/vmx/vmx.c:5325 __vmx_handle_exit arch/x86/kvm/vmx/vmx.c:6038 [inline] vmx_handle_exit+0x4be/0x1950 arch/x86/kvm/vmx/vmx.c:6055 vcpu_enter_guest+0x2a90/0x4410 arch/x86/kvm/x86.c:9752 vcpu_run arch/x86/kvm/x86.c:9819 [inline] kvm_arch_vcpu_ioctl_run+0x47c/0x1b10 arch/x86/kvm/x86.c:10051 kvm_vcpu_ioctl+0x570/0xf30 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 fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f8ad744aa39 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:00007f8ad49c0188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8ad754df60 RCX: 00007f8ad744aa39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f8ad74a4e8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffccaa8ee7f R14: 00007f8ad49c0300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 89 c2 mov %eax,%edx 2: 81 e2 00 01 00 00 and $0x100,%edx 8: a9 00 01 ff 00 test $0xff0100,%eax d: 74 10 je 0x1f f: 31 c0 xor %eax,%eax 11: 85 d2 test %edx,%edx 13: 74 15 je 0x2a 15: 8b 96 64 15 00 00 mov 0x1564(%rsi),%edx 1b: 85 d2 test %edx,%edx 1d: 74 0b je 0x2a 1f: 8b 86 40 15 00 00 mov 0x1540(%rsi),%eax 25: 39 f8 cmp %edi,%eax 27: 0f 94 c0 sete %al * 2a: c3 retq <-- trapping instruction 2b: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 32: 00 00 00 00 36: 0f 1f 00 nopl (%rax) 39: 31 c0 xor %eax,%eax 3b: 65 gs 3c: 8b .byte 0x8b 3d: 15 .byte 0x15 3e: 77 d4 ja 0x14