rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=6477, q=15) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294978624-4294968122), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g6477 f0x2 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:26576 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: NMI backtrace for cpu 1 CPU: 1 PID: 6512 Comm: syz-executor558 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_check_gp_kthread_starvation+0x1ff/0x270 kernel/rcu/tree_stall.h:481 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq+0x23d5/0x2bc0 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:handle_mm_fault+0x1fdf/0x2560 Code: e8 66 b6 13 00 41 89 c6 89 c6 81 e6 00 08 00 00 31 ff e8 f4 47 c6 ff 44 89 f0 25 00 08 00 00 0f 85 0b 02 00 00 e8 d1 43 c6 ff <8b> 84 24 94 00 00 00 85 c0 75 0a e8 c1 43 c6 ff e9 9f 00 00 00 4d RSP: 0018:ffffc900011ee800 EFLAGS: 00000293 RAX: ffffffff81bd6e63 RBX: 1ffff9200023dd34 RCX: ffff88801bd79c80 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc900011eea30 R08: ffffffff81be704f R09: ffffed10173a64a2 R10: ffffed10173a64a2 R11: 0000000000000000 R12: ffff88801bd79c80 R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000 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: 0033:0x7f5e59994139 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd4243dee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f5e59994139 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5e59957910 R13: 0000000000000000 R14: 00007ffd4243df20 R15: 00007ffd4243df10 ---------------- Code disassembly (best guess): 0: e8 66 b6 13 00 callq 0x13b66b 5: 41 89 c6 mov %eax,%r14d 8: 89 c6 mov %eax,%esi a: 81 e6 00 08 00 00 and $0x800,%esi 10: 31 ff xor %edi,%edi 12: e8 f4 47 c6 ff callq 0xffc6480b 17: 44 89 f0 mov %r14d,%eax 1a: 25 00 08 00 00 and $0x800,%eax 1f: 0f 85 0b 02 00 00 jne 0x230 25: e8 d1 43 c6 ff callq 0xffc643fb * 2a: 8b 84 24 94 00 00 00 mov 0x94(%rsp),%eax <-- trapping instruction 31: 85 c0 test %eax,%eax 33: 75 0a jne 0x3f 35: e8 c1 43 c6 ff callq 0xffc643fb 3a: e9 9f 00 00 00 jmpq 0xde 3f: 4d rex.WRB