rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=29969 jiffies, g=98417, q=63659) rcu: All QSes seen, last rcu_preempt kthread activity 29969 (4295033690-4295003721), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.1 R running task 26816 24157 9537 0x00000008 Call Trace: sched_show_task kernel/sched/core.c:5952 [inline] sched_show_task.cold+0x2e2/0x343 kernel/sched/core.c:5927 print_other_cpu_stall kernel/rcu/tree_stall.h:430 [inline] check_cpu_stall kernel/rcu/tree_stall.h:558 [inline] rcu_pending kernel/rcu/tree.c:3030 [inline] rcu_sched_clock_irq.cold+0xb35/0xc55 kernel/rcu/tree.c:2276 update_process_times+0x25/0x60 kernel/time/timer.c:1726 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:171 tick_sched_timer+0x4e/0x140 kernel/time/tick-sched.c:1314 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x32c/0xdd0 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x312/0x770 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline] smp_apic_timer_interrupt+0x15b/0x600 arch/x86/kernel/apic/apic.c:1144 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:__do_softirq+0x22f/0x99d kernel/softirq.c:278 Code: c7 c0 d0 b4 73 89 48 c1 e8 03 42 80 3c 30 00 0f 85 be 06 00 00 48 83 3d ae b2 93 01 00 0f 84 e1 05 00 00 fb 66 0f 1f 44 00 00 <48> c7 44 24 08 00 91 60 89 b8 ff ff ff ff 0f bc 04 24 83 c0 01 89 RSP: 0018:ffffc90000da8f38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff12e769a RBX: ffff88809ff4c640 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88809ff4ced4 RBP: 0000000000000025 R08: ffff88809ff4c640 R09: fffffbfff180e59b R10: fffffbfff180e59a R11: ffffffff8c072cd7 R12: 0000000000000025 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x192/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] do_IRQ+0xde/0x280 arch/x86/kernel/irq.c:263 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607 RIP: 0010:vcpu_enter_guest+0x2141/0x6120 arch/x86/kvm/x86.c:8343 Code: ff df 48 c1 e8 03 80 3c 10 00 0f 85 0e 37 00 00 48 83 3d 71 ad 65 08 00 0f 84 de 1a 00 00 e8 06 0c 64 00 fb 66 0f 1f 44 00 00 01 00 00 00 e8 75 aa 40 00 31 ff 65 8b 1d 04 17 f4 7e 89 de e8 RSP: 0018:ffffc9000282fb50 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffda RAX: 0000000000040000 RBX: 0000000000000001 RCX: ffffc900049f9000 RDX: 0000000000040000 RSI: ffffffff810e076a RDI: ffff88809ff4ced4 RBP: ffffc9000282fcc0 R08: ffff88809ff4c640 R09: fffffbfff180e59b R10: fffffbfff180e59a R11: ffffffff8c072cd7 R12: ffff88806167042c R13: 0000000000000001 R14: ffff888061670438 R15: ffff888061670400 vcpu_run arch/x86/kvm/x86.c:8511 [inline] kvm_arch_vcpu_ioctl_run+0x41c/0x1790 arch/x86/kvm/x86.c:8733 kvm_vcpu_ioctl+0x493/0xe60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2932 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c4a9 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5329649c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f532964a6d4 RCX: 000000000045c4a9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000007 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003bf R14: 00000000004c60e4 R15: 000000000076bf2c rcu: rcu_preempt kthread starved for 29969 jiffies! g98417 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29384 10 2 0x80004000 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_timeout+0x474/0xba0 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1658 [inline] rcu_gp_kthread+0x9d9/0x17d0 kernel/rcu/tree.c:1818 kthread+0x357/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352