rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=d22/1/0x4000000000000004 softirq=198647/198655 fqs=6 (t=10500 jiffies g=268837 q=135) rcu: rcu_preempt kthread starved for 10487 jiffies! g268837 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I29128 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4081 schedule+0xdc/0x2b0 kernel/sched/core.c:4155 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1821 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 2671 Comm: syz-executor.4 Not tainted 5.5.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq.cold+0x509/0xc0d kernel/rcu/tree.c:2271 update_process_times+0x2d/0x70 kernel/time/timer.c:1726 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:__kasan_check_write+0x1/0x20 mm/kasan/common.c:101 Code: 3e ef ff ff cc cc cc cc cc 55 89 f6 31 d2 48 89 e5 48 8b 4d 08 e8 1f 2a 00 00 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 <89> f6 ba 01 00 00 00 48 89 e5 48 8b 4d 08 e8 fc 29 00 00 5d c3 66 RSP: 0018:ffffc90000da8c18 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: 1ffff920001b5186 RCX: 0000000000000000 RDX: 00000000ffffffff RSI: 0000000000000004 RDI: ffff8880a34830a0 RBP: ffffc90000da8cb8 R08: 0000000000003375 R09: fffffbfff165ebbc R10: ffff8880a2978f50 R11: ffff8880a2978640 R12: ffff8880a34830a0 R13: ffff8880a34830a8 R14: ffff8880a34830b0 R15: ffffc90000da8c90 __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_lock+0x37/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] mrp_join_timer+0x2b/0x80 net/802/mrp.c:590 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:qlink_to_object mm/kasan/quarantine.c:137 [inline] RIP: 0010:qlink_free mm/kasan/quarantine.c:142 [inline] RIP: 0010:qlist_free_all+0x39/0x150 mm/kasan/quarantine.c:167 Code: 53 48 83 ec 08 48 8b 37 48 85 f6 0f 84 0d 01 00 00 4d 85 e4 49 89 fe 4d 89 e7 0f 84 8c 00 00 00 49 63 87 34 01 00 00 4c 8b 2e <48> 29 c6 48 83 3d dc 50 e0 07 00 0f 84 f2 00 00 00 9c 58 0f 1f 44 RSP: 0018:ffffc900084b75c8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 0000000000000282 RCX: ffffea00013a5987 RDX: 0000000000000000 RSI: ffff8880a2dd8000 RDI: 0000000000000007 RBP: ffffc900084b75f8 R08: ffff8880a2978640 R09: fffffbfff165eba8 R10: fffffbfff165eba7 R11: ffffffff8b2f5d3f R12: 0000000000000000 R13: ffff8880a6fdccc0 R14: ffffc900084b7608 R15: ffff8880aa402000 quarantine_reduce+0x15e/0x1a0 mm/kasan/quarantine.c:260 __kasan_kmalloc.constprop.0+0xa3/0xe0 mm/kasan/common.c:494 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:521 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3484 __d_alloc+0x2e/0x8c0 fs/dcache.c:1690 d_alloc+0x4d/0x280 fs/dcache.c:1769 d_alloc_parallel+0xf4/0x1c00 fs/dcache.c:2521 __lookup_slow+0x1ab/0x500 fs/namei.c:1648 lookup_one_len+0x16d/0x1a0 fs/namei.c:2530 start_creating+0xc5/0x1d0 fs/debugfs/inode.c:335 __debugfs_create_file+0x65/0x3f0 fs/debugfs/inode.c:380 debugfs_create_file+0x5a/0x70 fs/debugfs/inode.c:437 kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:656 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3544 [inline] kvm_dev_ioctl+0x8b4/0x17d0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3571 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:545 [inline] do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45af49 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:00007f8681e85c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49 RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8681e866d4 R13: 00000000004c44de R14: 00000000004dadb0 R15: 00000000ffffffff