rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=e8d/1/0x4000000000000000 softirq=15090/15090 fqs=1 (t=10500 jiffies g=18809 q=35) rcu: rcu_preempt kthread starved for 10495 jiffies! g18809 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: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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9634 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:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:110 Code: c7 00 38 ef 8e e8 28 37 8a 00 eb b0 66 0f 1f 44 00 00 be 01 00 00 00 e9 26 21 2d 00 cc cc cc cc cc cc 89 ff 89 b7 00 c0 5f ff 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb 48 RSP: 0018:ffffc90000007eb8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff8b331a60 RCX: 0000000000000020 RDX: 1ffffffff166634e RSI: 000000000000003e RDI: 0000000000000380 RBP: ffff8880b9c1f300 R08: 000000000000003f R09: 0000000000000000 R10: ffffffff8168e737 R11: 0000000000000000 R12: 000000000000003e R13: 0000000000000020 R14: 0000000000000000 R15: ffff8880b9c223c0 FS: 00007f4189383700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000001d4d7000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x4d/0x80 arch/x86/kernel/apic/apic.c:469 clockevents_program_event+0x254/0x370 kernel/time/clockevents.c:334 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36e/0x790 kernel/time/hrtimer.c:1824 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:__get_user_pages+0x365/0xf80 mm/gup.c:1083 Code: fe 31 ff e8 dd f3 cb ff 4d 85 ff 4c 0f 44 fb e8 f1 ed cb ff 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 20 48 c7 00 00 00 00 00 <48> c7 40 08 00 00 00 00 48 8b 84 24 f0 00 00 00 65 48 2b 04 25 28 RSP: 0018:ffffc9000847f2c0 EFLAGS: 00000286 RAX: fffff5200108fe63 RBX: fffffffffffffff2 RCX: ffffc9000fe16000 RDX: 0000000000040000 RSI: ffffffff81aa20af RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81aa20a3 R11: 0000000000000000 R12: 0000000000000002 R13: ffff8880746fa250 R14: 0000000000000306 R15: fffffffffffffff2 __get_user_pages_locked mm/gup.c:1343 [inline] get_user_pages_unlocked+0x1b3/0x760 mm/gup.c:2067 hva_to_pfn_slow arch/x86/kvm/../../../virt/kvm/kvm_main.c:2269 [inline] hva_to_pfn+0x1c1/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2401 __gfn_to_pfn_memslot+0x229/0x420 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2460 kvm_faultin_pfn+0x3d8/0xbc0 arch/x86/kvm/mmu/mmu.c:3957 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:9735 vcpu_run arch/x86/kvm/x86.c:9802 [inline] kvm_arch_vcpu_ioctl_run+0x47c/0x1b10 arch/x86/kvm/x86.c:10034 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: 0033:0x7f418be0da39 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:00007f4189383188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f418bf10f60 RCX: 00007f418be0da39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f418be67e8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc32e64c2f R14: 00007f4189383300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 9631 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 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:vcpu_enter_guest+0x28cf/0x4410 arch/x86/kvm/x86.c:9717 Code: 3c 02 00 0f 85 9a 17 00 00 48 b8 00 00 00 00 00 00 00 80 49 89 87 80 00 00 00 e8 7c c5 64 00 e8 87 ef 6a 00 fb bf 01 00 00 00 3c 74 3d 00 31 ff 65 44 8b 3d c2 a6 f0 7e 44 89 fe e8 0a ce 64 RSP: 0018:ffffc90006c7fb90 EFLAGS: 00000202 RAX: 000000000082a857 RBX: 1ffff92000d8ff7c RCX: 1ffffffff1fac65a RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffc90006c7fcb0 R08: 0000000000000001 R09: ffffffff8fd05adf R10: 0000000000000001 R11: 0000000000000001 R12: ffff88808a73c340 R13: ffff88808a73c378 R14: 0000000000000000 R15: 0000000000000000 vcpu_run arch/x86/kvm/x86.c:9802 [inline] kvm_arch_vcpu_ioctl_run+0x47c/0x1b10 arch/x86/kvm/x86.c:10034 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: 0033:0x7f79c5d20a39 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:00007f79c3296188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f79c5e23f60 RCX: 00007f79c5d20a39 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f79c5d7ae8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdaffa8fdf R14: 00007f79c3296300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: c7 00 38 ef 8e e8 movl $0xe88eef38,(%rax) 6: 28 37 sub %dh,(%rdi) 8: 8a 00 mov (%rax),%al a: eb b0 jmp 0xffffffbc c: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 12: be 01 00 00 00 mov $0x1,%esi 17: e9 26 21 2d 00 jmpq 0x2d2142 1c: cc int3 1d: cc int3 1e: cc int3 1f: cc int3 20: cc int3 21: cc int3 22: 89 ff mov %edi,%edi 24: 89 b7 00 c0 5f ff mov %esi,-0xa04000(%rdi) * 2a: c3 retq <-- trapping instruction 2b: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 32: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 39: fc ff df 3c: 53 push %rbx 3d: 89 fb mov %edi,%ebx 3f: 48 rex.W