rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=7fa/1/0x4000000000000004 softirq=10410/10410 fqs=0 (t=10500 jiffies g=8977 q=232) rcu: rcu_preempt kthread starved for 10500 jiffies! g8977 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17a0 kernel/sched/core.c:3937 schedule+0xd9/0x260 kernel/sched/core.c:4004 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1893 rcu_gp_fqs_loop kernel/rcu/tree.c:1639 [inline] rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1799 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: 8707 Comm: syz-executor.0 Not tainted 5.3.0-rc6-next-20190830 #75 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+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:2795 [inline] rcu_sched_clock_irq.cold+0x4fd/0xc12 kernel/rcu/tree.c:2244 update_process_times+0x2d/0x70 kernel/time/timer.c:1724 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1299 __run_hrtimer kernel/time/hrtimer.c:1504 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1566 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1628 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1131 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:__sanitizer_cov_trace_pc+0x1a/0x50 kernel/kcov.c:98 Code: 00 00 e9 77 e9 ff ff 90 90 90 90 90 90 90 90 90 55 48 89 e5 65 48 8b 04 25 40 fe 01 00 65 8b 15 e4 a7 8f 7e 81 e2 00 01 1f 00 <48> 8b 75 08 75 2b 8b 90 00 13 00 00 83 fa 02 75 20 48 8b 88 08 13 RSP: 0018:ffff8880ae909508 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: ffff888093d92140 RBX: ffff888090aa6af8 RCX: ffffffff85cb6f79 RDX: 0000000000000100 RSI: ffffffff85cb6f8b RDI: ffff888090aa6b00 RBP: ffff8880ae909508 R08: ffff888093d92140 R09: fffffbfff14ed341 R10: ffff888093d92b70 R11: ffff888093d92140 R12: dffffc0000000000 R13: ffff888090aa6800 R14: ffff888090aa6b98 R15: ffff888090aa6b90 __read_once_size include/linux/compiler.h:176 [inline] list_empty include/linux/list.h:268 [inline] hhf_dequeue+0x51/0xa20 net/sched/sch_hhf.c:427 dequeue_skb net/sched/sch_generic.c:258 [inline] qdisc_restart net/sched/sch_generic.c:361 [inline] __qdisc_run+0x1e7/0x19d0 net/sched/sch_generic.c:379 __dev_xmit_skb net/core/dev.c:3533 [inline] __dev_queue_xmit+0x16f1/0x37c0 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0xf58/0x2550 net/ipv6/ip6_output.c:116 __ip6_finish_output+0x444/0xaa0 net/ipv6/ip6_output.c:142 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x235/0x7f0 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ndisc_send_skb+0xf29/0x14a0 net/ipv6/ndisc.c:505 ndisc_send_rs+0x134/0x6d0 net/ipv6/ndisc.c:699 addrconf_rs_timer+0x30f/0x680 net/ipv6/addrconf.c:3879 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1771 [inline] __run_timers kernel/time/timer.c:1738 [inline] run_timer_softirq+0x6c0/0x17f0 kernel/time/timer.c:1784 __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:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:check_kcov_mode kernel/kcov.c:68 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x1e/0x50 kernel/kcov.c:102 Code: e9 ff ff 90 90 90 90 90 90 90 90 90 55 48 89 e5 65 48 8b 04 25 40 fe 01 00 65 8b 15 e4 a7 8f 7e 81 e2 00 01 1f 00 48 8b 75 08 <75> 2b 8b 90 00 13 00 00 83 fa 02 75 20 48 8b 88 08 13 00 00 8b 80 RSP: 0018:ffff888095827838 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff888093d92140 RBX: 0000000000000000 RCX: ffffffff819e2d4e RDX: 0000000000000000 RSI: ffffffff819e31c1 RDI: 0000000000000001 RBP: ffff888095827838 R08: ffff888093d92140 R09: fffff9400048cb9f R10: fffff9400048cb9e R11: ffffea0002465cf3 R12: ffffea0002465cc0 R13: 8000000091973007 R14: 0000000000000018 R15: dffffc0000000000 __read_once_size include/linux/compiler.h:176 [inline] compound_head include/linux/page-flags.h:174 [inline] PageSwapBacked include/linux/page-flags.h:340 [inline] mm_counter_file include/linux/mm.h:1665 [inline] mm_counter include/linux/mm.h:1674 [inline] copy_one_pte mm/memory.c:774 [inline] copy_pte_range mm/memory.c:823 [inline] copy_pmd_range mm/memory.c:874 [inline] copy_pud_range mm/memory.c:908 [inline] copy_p4d_range mm/memory.c:930 [inline] copy_page_range+0x1051/0x1ed0 mm/memory.c:992 dup_mmap kernel/fork.c:606 [inline] dup_mm+0xa67/0x1430 kernel/fork.c:1364 copy_mm kernel/fork.c:1420 [inline] copy_process+0x2671/0x6830 kernel/fork.c:2015 _do_fork+0x146/0xfa0 kernel/fork.c:2367 __do_sys_clone kernel/fork.c:2522 [inline] __se_sys_clone kernel/fork.c:2503 [inline] __x64_sys_clone+0x1ab/0x270 kernel/fork.c:2503 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457eba Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00 RSP: 002b:00007ffddd38fe40 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffddd38fe40 RCX: 0000000000457eba RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffddd38fe80 R08: 0000000000000001 R09: 0000555556e2a940 R10: 0000555556e2ac10 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffddd38fed0