rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=0b2/1/0x4000000000000004 softirq=31579/31579 fqs=0 (t=10501 jiffies g=41869 q=621) rcu: rcu_preempt kthread starved for 10502 jiffies! g41869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I29520 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3880 schedule+0xd9/0x260 kernel/sched/core.c:3947 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1807 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline] rcu_gp_kthread+0x9b2/0x18c0 kernel/rcu/tree.c:1768 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: 15366 Comm: syz-executor.3 Not tainted 5.3.0-rc7+ #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+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:2736 [inline] rcu_sched_clock_irq.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183 update_process_times+0x32/0x80 kernel/time/timer.c:1639 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 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:__list_del_entry include/linux/list.h:131 [inline] RIP: 0010:list_move_tail include/linux/list.h:213 [inline] RIP: 0010:hhf_dequeue+0x5d1/0xa20 net/sched/sch_hhf.c:439 Code: d2 0f 85 3f 04 00 00 45 0f af b5 14 03 00 00 48 89 df 45 01 fe 44 89 73 10 e8 5b 71 76 fd 31 ff 41 89 c6 89 c6 e8 bf 95 aa fb <45> 84 f6 74 63 e8 75 94 aa fb 48 89 d8 48 c1 e8 03 42 80 3c 20 00 RSP: 0018:ffff8880ae908e78 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000702 RBX: ffff888093c714f8 RCX: ffffffff85c7e0d1 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8880ae908ec8 R08: ffff888097d02300 R09: fffffbfff14e9555 R10: ffff888097d02d20 R11: ffff888097d02300 R12: dffffc0000000000 R13: ffff888093c71200 R14: 0000000000000001 R15: 0000000000000000 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+0x16f1/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 br_dev_queue_push_xmit+0x3f3/0x5c0 net/bridge/br_forward.c:52 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] br_forward_finish+0xfa/0x400 net/bridge/br_forward.c:65 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] __br_forward+0x641/0xb00 net/bridge/br_forward.c:109 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:125 maybe_deliver+0x2c7/0x390 net/bridge/br_forward.c:181 br_flood+0x13a/0x3d0 net/bridge/br_forward.c:223 br_dev_xmit+0x98c/0x15a0 net/bridge/br_device.c:100 __netdev_start_xmit include/linux/netdevice.h:4419 [inline] netdev_start_xmit include/linux/netdevice.h:4433 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296 __dev_queue_xmit+0x2b15/0x3650 net/core/dev.c:3869 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+0xf58/0x2520 net/ipv6/ip6_output.c:116 __ip6_finish_output+0x444/0xa50 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+0x235/0x7c0 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+0xf29/0x1450 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:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __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:537 [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:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:95 Code: 25 d4 7c 39 09 41 bc f4 ff ff ff e8 6d 9f e9 ff 48 c7 05 be 7c 39 09 00 00 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 a4 88 8f 7e 81 e2 00 RSP: 0018:ffff88805e0177b8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000002 RBX: ffffea0001d51908 RCX: ffffffff818ebc84 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffff88805e0178f8 R08: ffff888097d02300 R09: fffff940003aa329 R10: fffff940003aa328 R11: ffffea0001d51947 R12: 0000000000000000 R13: ffff888094861d20 R14: ffffea0001d51940 R15: ffff88805e0178d0 do_fault_around mm/memory.c:3441 [inline] do_read_fault mm/memory.c:3475 [inline] do_fault mm/memory.c:3609 [inline] handle_pte_fault mm/memory.c:3840 [inline] __handle_mm_fault+0x3241/0x3f20 mm/memory.c:3964 handle_mm_fault+0x1b5/0x6b0 mm/memory.c:4001 faultin_page mm/gup.c:651 [inline] __get_user_pages+0x7d4/0x1b30 mm/gup.c:854 populate_vma_page_range+0x20d/0x2a0 mm/gup.c:1230 __mm_populate+0x204/0x380 mm/gup.c:1278 mm_populate include/linux/mm.h:2383 [inline] vm_mmap_pgoff+0x213/0x230 mm/util.c:396 ksys_mmap_pgoff+0xf7/0x630 mm/mmap.c:1611 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4598e9 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f35adeb9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000004598e9 RDX: 0000000000000006 RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 000000000075bf20 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 00007f35adeba6d4 R13: 00000000004c5db4 R14: 00000000004da890 R15: 00000000ffffffff