BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 122s! BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 122s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=8/256 pending: defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, perf_sched_delayed, defense_work_handler, cache_reap pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=8/256 in-flight: 25625:bpf_map_free_deferred, 5031:bpf_map_free_deferred pending: defense_work_handler, vmstat_shepherd, defense_work_handler, defense_work_handler, cache_reap, check_corruption workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/512 in-flight: 4597:call_usermodehelper_exec_work workqueue events_power_efficient: flags=0x80 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=3/256 pending: gc_worker, do_cache_clean, neigh_periodic_work pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 pending: neigh_periodic_work workqueue mm_percpu_wq: flags=0x8 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 pending: vmstat_update pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 pending: vmstat_update workqueue writeback: flags=0x4e pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 pending: wb_workfn workqueue ib_addr: flags=0xa0002 pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 pending: process_req workqueue dm_bufio_cache: flags=0x8 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 pending: work_fn workqueue ipv6_addrconf: flags=0x40008 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 pending: addrconf_verify_work pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=123s workers=8 idle: 15008 5125 4 25 5127 1979 pool 4: cpus=0-1 flags=0x4 nice=0 hung=120s workers=8 idle: 4562 93 30140 22 4627 4593 4573 INFO: rcu_sched self-detected stall on CPU 0-...!: (124798 ticks this GP) idle=78a/1/4611686018427387906 softirq=158505/158505 fqs=14 (t=125000 jiffies g=88437 c=88436 q=737) rcu_sched kthread starved for 124939 jiffies! g88437 c88436 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 RCU grace-period kthread stack dump: rcu_sched R running task 23768 9 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3490 schedule+0xef/0x430 kernel/sched/core.c:3549 schedule_timeout+0x138/0x240 kernel/time/timer.c:1801 rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231 kthread+0x345/0x410 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 NMI backtrace for cpu 0 CPU: 0 PID: 3198 Comm: syz-executor6 Not tainted 4.17.0-rc3+ #4 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+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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:156 [inline] rcu_dump_cpu_stacks+0x175/0x1c2 kernel/rcu/tree.c:1376 print_cpu_stall kernel/rcu/tree.c:1525 [inline] check_cpu_stall.isra.61.cold.80+0x36c/0x59a kernel/rcu/tree.c:1593 __rcu_pending kernel/rcu/tree.c:3356 [inline] rcu_pending kernel/rcu/tree.c:3401 [inline] rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763 update_process_times+0x2d/0x70 kernel/time/timer.c:1636 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274 __run_hrtimer kernel/time/hrtimer.c:1398 [inline] __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline] RIP: 0010:lock_acquire+0x257/0x520 kernel/locking/lockdep.c:3923 RSP: 0018:ffff8801b1e6f8d8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 1ffff100363cdf20 RCX: 0000000000000000 RDX: 1ffffffff11a316d RSI: ffff8801a7e5eb38 RDI: 0000000000000286 RBP: ffff8801b1e6f9c8 R08: 0000000000004394 R09: 0000000000000004 R10: ffff8801a7e5ebd8 R11: ffff8801a7e5e300 R12: ffff8801a7e5e300 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 _raw_spin_lock_nested+0x28/0x40 kernel/locking/spinlock.c:354 d_walk+0x3ad/0xc80 fs/dcache.c:1274 shrink_dcache_parent+0x179/0x230 fs/dcache.c:1486 vfs_rmdir+0x202/0x470 fs/namei.c:3850 do_rmdir+0x523/0x610 fs/namei.c:3911 __do_sys_rmdir fs/namei.c:3929 [inline] __se_sys_rmdir fs/namei.c:3927 [inline] __x64_sys_rmdir+0x36/0x40 fs/namei.c:3927 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4556e7 RSP: 002b:00007ffd6f0dcb08 EFLAGS: 00000202 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00000000004556e7 RDX: 0000000000000000 RSI: 00007ffd6f0de8b0 RDI: 00007ffd6f0de8b0 RBP: 00007ffd6f0de8b0 R08: 0000000000000000 R09: 0000000000000001 R10: 000000000000000a R11: 0000000000000202 R12: 0000000001413940 R13: 0000000000000000 R14: 00000000000000a1 R15: 0000000000078348