rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=9549, q=18) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294978228-4294967726), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g9549 f0x2 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:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6302 schedule+0xd3/0x270 kernel/sched/core.c:6381 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 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: 6527 Comm: syz-executor554 Not tainted 5.15.0-rc1-next-20210914-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_preemption_disabled+0x13/0x140 lib/smp_processor_id.c:14 Code: 00 e8 31 70 1f f8 eb 99 0f 1f 44 00 00 0f 0b e9 23 ff ff ff cc cc cc 41 56 41 55 49 89 f5 41 54 55 48 89 fd 53 0f 1f 44 00 00 <65> 44 8b 25 2d de ce 76 65 8b 1d be 38 cf 76 81 e3 ff ff ff 7f 31 RSP: 0018:ffffc90002b17300 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880267eb900 RSI: ffffffff89888900 RDI: ffffffff89e43740 RBP: ffffffff89e43740 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff817c3c8c R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff89888900 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000001739300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000007e0ac000 CR4: 00000000001526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sysvec_apic_timer_interrupt+0x73/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 65 8b 05 69 e1 8b 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 f0 01 00 a9 RSP: 0018:ffffc90002b173f0 EFLAGS: 00000282 RAX: 0000000080000000 RBX: fffffffffffffff2 RCX: fffffffffffffff2 RDX: 0000000000000000 RSI: ffff8880267eb900 RDI: 0000000000000003 RBP: ffff888015bab800 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81a96608 R11: 0000000000000000 R12: 0000000020000000 R13: ffff8880267eb900 R14: ffffc90002b17558 R15: ffff888015bab8b8 __get_user_pages_locked mm/gup.c:1366 [inline] get_user_pages_unlocked+0x692/0x760 mm/gup.c:2067 hva_to_pfn_slow arch/x86/kvm/../../../virt/kvm/kvm_main.c:2251 [inline] hva_to_pfn+0x1c1/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2383 __gfn_to_pfn_memslot+0x229/0x420 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2442 kvm_faultin_pfn+0x171/0xbc0 arch/x86/kvm/mmu/mmu.c:3939 direct_page_fault+0xd22/0x2320 arch/x86/kvm/mmu/mmu.c:3989 kvm_mmu_do_page_fault arch/x86/kvm/mmu.h:127 [inline] kvm_mmu_page_fault+0x17e/0x17f0 arch/x86/kvm/mmu/mmu.c:5284 handle_ept_violation+0x29c/0x6e0 arch/x86/kvm/vmx/vmx.c:5324 __vmx_handle_exit arch/x86/kvm/vmx/vmx.c:6033 [inline] vmx_handle_exit+0x4be/0x1950 arch/x86/kvm/vmx/vmx.c:6050 vcpu_enter_guest+0x2a90/0x4410 arch/x86/kvm/x86.c:9721 vcpu_run arch/x86/kvm/x86.c:9788 [inline] kvm_arch_vcpu_ioctl_run+0x47c/0x1b10 arch/x86/kvm/x86.c:10020 kvm_vcpu_ioctl+0x570/0xf30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3749 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: 0033:0x43ff99 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:00007ffdb97777a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 000000000043ff99 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000403770 R13: 0000000000000000 R14: 00007ffdb97777e0 R15: 00007ffdb97777d0 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.108 msecs ---------------- Code disassembly (best guess): 0: 00 e8 add %ch,%al 2: 31 70 1f xor %esi,0x1f(%rax) 5: f8 clc 6: eb 99 jmp 0xffffffa1 8: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) d: 0f 0b ud2 f: e9 23 ff ff ff jmpq 0xffffff37 14: cc int3 15: cc int3 16: cc int3 17: 41 56 push %r14 19: 41 55 push %r13 1b: 49 89 f5 mov %rsi,%r13 1e: 41 54 push %r12 20: 55 push %rbp 21: 48 89 fd mov %rdi,%rbp 24: 53 push %rbx 25: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) * 2a: 65 44 8b 25 2d de ce mov %gs:0x76cede2d(%rip),%r12d # 0x76cede5f <-- trapping instruction 31: 76 32: 65 8b 1d be 38 cf 76 mov %gs:0x76cf38be(%rip),%ebx # 0x76cf38f7 39: 81 e3 ff ff ff 7f and $0x7fffffff,%ebx 3f: 31 .byte 0x31