syz-executor.1 (16623) used greatest stack depth: 22320 bytes left rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=73a/1/0x4000000000000002 softirq=45898/45898 fqs=510 rcu: (t=10501 jiffies g=55829 q=4576) rcu: rcu_preempt kthread starved for 9478 jiffies! g55829 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I29104 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 schedule_timeout+0x4db/0xfc0 kernel/time/timer.c:1804 rcu_gp_kthread+0xd5c/0x2190 kernel/rcu/tree.c:2202 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 NMI backtrace for cpu 1 CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.19.73 #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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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+0x189/0x1d5 kernel/rcu/tree.c:1340 print_cpu_stall kernel/rcu/tree.c:1478 [inline] check_cpu_stall kernel/rcu/tree.c:1550 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0x5e3/0xd90 kernel/rcu/tree.c:2682 update_process_times+0x32/0x80 kernel/time/timer.c:1636 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:164 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1274 __run_hrtimer kernel/time/hrtimer.c:1398 [inline] __hrtimer_run_queues+0x33b/0xdc0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1067 [inline] smp_apic_timer_interrupt+0x111/0x550 arch/x86/kernel/apic/apic.c:1092 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:hhf_dequeue+0x4e6/0xa00 net/sched/sch_hhf.c:427 Code: 03 42 80 3c 20 00 0f 85 56 04 00 00 4c 89 f8 4c 89 7b 08 48 c1 e8 03 42 80 3c 20 00 0f 85 05 04 00 00 49 89 1f e9 66 fb ff ff 85 a5 dc fb 48 8b 45 b8 4c 8b 75 c8 42 80 3c 20 00 0f 85 13 04 RSP: 0018:ffff8880aa2a6998 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff888075c57580 RBX: ffff888075c574f8 RCX: ffffffff858ebe8e RDX: 0000000000000100 RSI: ffff888075c57580 RDI: ffff888075c57500 RBP: ffff8880aa2a69e8 R08: ffff8880aa2944c0 R09: 0000000000000006 R10: ffff8880aa294e30 R11: 00000000b42a04f8 R12: dffffc0000000000 R13: ffff888075c57240 R14: ffff888075c57580 R15: ffff888075c57590 dequeue_skb net/sched/sch_generic.c:277 [inline] qdisc_restart net/sched/sch_generic.c:380 [inline] __qdisc_run+0x1e7/0x1960 net/sched/sch_generic.c:398 __dev_xmit_skb net/core/dev.c:3501 [inline] __dev_queue_xmit+0x165c/0x2fe0 net/core/dev.c:3811 dev_queue_xmit+0x18/0x20 net/core/dev.c:3876 br_dev_queue_push_xmit+0x405/0x5d0 net/bridge/br_forward.c:56 br_nf_dev_queue_xmit+0x365/0x1610 net/bridge/br_netfilter_hooks.c:779 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] br_nf_post_routing+0x76f/0x12f0 net/bridge/br_netfilter_hooks.c:825 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline] nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:511 nf_hook include/linux/netfilter.h:244 [inline] NF_HOOK include/linux/netfilter.h:287 [inline] br_forward_finish+0x215/0x400 net/bridge/br_forward.c:69 br_nf_hook_thresh+0x2e9/0x370 net/bridge/br_netfilter_hooks.c:1008 br_nf_forward_finish+0x356/0x700 net/bridge/br_netfilter_hooks.c:553 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] br_nf_forward_ip net/bridge/br_netfilter_hooks.c:620 [inline] br_nf_forward_ip+0x6b4/0x17c0 net/bridge/br_netfilter_hooks.c:564 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline] nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:511 nf_hook include/linux/netfilter.h:244 [inline] NF_HOOK include/linux/netfilter.h:287 [inline] __br_forward+0x393/0xb30 net/bridge/br_forward.c:113 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:129 br_flood+0x5fa/0x710 net/bridge/br_forward.c:238 br_handle_frame_finish+0xf72/0x1510 net/bridge/br_input.c:167 br_nf_hook_thresh+0x2e9/0x370 net/bridge/br_netfilter_hooks.c:1008 br_nf_pre_routing_finish_ipv6+0x6ed/0xd70 net/bridge/br_netfilter_ipv6.c:210 NF_HOOK include/linux/netfilter.h:289 [inline] br_nf_pre_routing_ipv6+0x4a5/0x8ca net/bridge/br_netfilter_ipv6.c:240 br_nf_pre_routing+0x1016/0x159c net/bridge/br_netfilter_hooks.c:494 nf_hook_entry_hookfn include/linux/netfilter.h:119 [inline] nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:511 nf_hook include/linux/netfilter.h:244 [inline] NF_HOOK include/linux/netfilter.h:287 [inline] br_handle_frame+0x985/0x1480 net/bridge/br_input.c:306 __netif_receive_skb_core+0xac1/0x3570 net/core/dev.c:4861 __netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:4930 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5044 process_backlog+0x23a/0x7a0 net/core/dev.c:5855 napi_poll net/core/dev.c:6278 [inline] net_rx_action+0x4f5/0x1070 net/core/dev.c:6344 __do_softirq+0x25c/0x921 kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:653 [inline] run_ksoftirqd+0x8e/0x110 kernel/softirq.c:645 smpboot_thread_fn+0x6a3/0xa30 kernel/smpboot.c:164 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415