INFO: rcu_sched self-detected stall on CPU 1-...!: (1 GPs behind) idle=a3e/1/4611686018427387908 softirq=71980/71983 fqs=33 (t=125000 jiffies g=39438 c=39437 q=958) rcu_sched kthread starved for 124829 jiffies! g39438 c39437 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:411 NMI backtrace for cpu 1 CPU: 1 PID: 20560 Comm: syz-executor4 Not tainted 4.16.0+ #1 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:173 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1283 __run_hrtimer kernel/time/hrtimer.c:1386 [inline] __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1448 hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1506 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:862 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline] RIP: 0010:kmem_cache_free+0xb3/0x2d0 mm/slab.c:3757 RSP: 0018:ffff8801db105228 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: ffff8800b055c940 RCX: 1ffff1003b2345a5 RDX: 0000000000000000 RSI: ffff8801d91a2d80 RDI: 0000000000000282 RBP: ffff8801db105248 R08: ffff8801d91a2cb8 R09: 0000000000000002 R10: ffff8801d91a2480 R11: 0000000000000000 R12: ffff8801d9848e40 R13: 0000000000000282 R14: ffffffff85b7f27c R15: 0000000000000000 kfree_skbmem+0x13c/0x210 net/core/skbuff.c:582 __kfree_skb net/core/skbuff.c:642 [inline] kfree_skb+0x19d/0x560 net/core/skbuff.c:659 enqueue_to_backlog+0x2fc/0xc90 net/core/dev.c:3968 netif_rx_internal+0x14d/0xae0 net/core/dev.c:4181 netif_rx+0xba/0x400 net/core/dev.c:4206 loopback_xmit+0x283/0x741 drivers/net/loopback.c:91 __netdev_start_xmit include/linux/netdevice.h:4087 [inline] netdev_start_xmit include/linux/netdevice.h:4096 [inline] xmit_one net/core/dev.c:3053 [inline] dev_hard_start_xmit+0x264/0xc10 net/core/dev.c:3069 __dev_queue_xmit+0x2724/0x34c0 net/core/dev.c:3584 dev_queue_xmit+0x17/0x20 net/core/dev.c:3617 neigh_hh_output include/net/neighbour.h:472 [inline] neigh_output include/net/neighbour.h:480 [inline] ip6_finish_output2+0x134e/0x2810 net/ipv6/ip6_output.c:120 ip6_finish_output+0x5fe/0xbc0 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:277 [inline] ip6_output+0x227/0x9b0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] NF_HOOK include/linux/netfilter.h:288 [inline] ip6_xmit+0xf51/0x23f0 net/ipv6/ip6_output.c:277 sctp_v6_xmit+0x4a5/0x6b0 net/sctp/ipv6.c:225 sctp_packet_transmit+0x26f6/0x3ba0 net/sctp/output.c:650 sctp_outq_flush+0x1373/0x4370 net/sctp/outqueue.c:1197 sctp_outq_uncork+0x6a/0x80 net/sctp/outqueue.c:776 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1820 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline] sctp_do_sm+0x596/0x7160 net/sctp/sm_sideeffect.c:1191 sctp_generate_heartbeat_event+0x218/0x450 net/sctp/sm_sideeffect.c:406 call_timer_fn+0x230/0x940 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x79e/0xc50 kernel/time/timer.c:1666 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1d1/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:525 [inline] smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline] RIP: 0010:lock_release+0x4d4/0xa10 kernel/locking/lockdep.c:3942 RSP: 0018:ffff8801971ce7b0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 1ffff10032e39cfb RCX: 1ffff1003b234595 RDX: 1ffffffff11630ed RSI: 0000000000000002 RDI: 0000000000000282 RBP: ffff8801971ce8e0 R08: 1ffff10032e39cff R09: ffffed003b6246c2 R10: 0000000000000003 R11: 0000000000000001 R12: ffff8801d91a2480 R13: ffffffff88b8df60 R14: ffff8801d91a2480 R15: ffff8801971ce7f8 rcu_lock_release include/linux/rcupdate.h:251 [inline] rcu_read_unlock include/linux/rcupdate.h:688 [inline] __unlock_page_memcg+0x72/0x100 mm/memcontrol.c:1654 unlock_page_memcg+0x2c/0x40 mm/memcontrol.c:1663 page_remove_file_rmap mm/rmap.c:1248 [inline] page_remove_rmap+0x6f2/0x1250 mm/rmap.c:1299 zap_pte_range mm/memory.c:1337 [inline] zap_pmd_range mm/memory.c:1441 [inline] zap_pud_range mm/memory.c:1470 [inline] zap_p4d_range mm/memory.c:1491 [inline] unmap_page_range+0xeb4/0x2200 mm/memory.c:1512 unmap_single_vma+0x1a0/0x310 mm/memory.c:1557 unmap_vmas+0x120/0x1f0 mm/memory.c:1587 exit_mmap+0x265/0x570 mm/mmap.c:3038 __mmput kernel/fork.c:962 [inline] mmput+0x251/0x610 kernel/fork.c:983 exit_mm kernel/exit.c:544 [inline] do_exit+0xe98/0x2730 kernel/exit.c:852 do_group_exit+0x16f/0x430 kernel/exit.c:968 get_signal+0x886/0x1960 kernel/signal.c:2469 do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810 exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x792/0x9d0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x455319 RSP: 002b:00007fa346e81ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000072bf80 RCX: 0000000000455319 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bf80 RBP: 000000000072bf80 R08: 0000000000000000 R09: 000000000072bf58 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000a3e81f R14: 00007fa346e829c0 R15: 0000000000000001