rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=c8e/1/0x4000000000000004 softirq=81389/81390 fqs=3071 (t=10501 jiffies g=131505 q=1236) rcu: rcu_preempt kthread starved for 4357 jiffies! g131505 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I29112 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 0 CPU: 0 PID: 7417 Comm: syz-executor.1 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:__sanitizer_cov_trace_const_cmp1+0x11/0x20 kernel/kcov.c:175 Code: bf 06 00 00 00 48 89 e5 48 8b 4d 08 e8 18 ff ff ff 5d c3 66 0f 1f 44 00 00 55 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 48 89 e5 <48> 8b 4d 08 e8 f6 fe ff ff 5d c3 0f 1f 40 00 55 0f b7 d6 0f b7 f7 RSP: 0018:ffff8880ae808dd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffff888099ec0c38 RCX: ffffffff85c7df19 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8880ae808dd8 R08: ffff8880a3f88500 R09: fffffbfff14e9755 R10: ffff8880a3f88ea8 R11: ffff8880a3f88500 R12: dffffc0000000000 R13: ffff888099ec0940 R14: 0000000000000001 R15: 0000000000000000 __list_del_entry include/linux/list.h:131 [inline] list_move_tail include/linux/list.h:213 [inline] hhf_dequeue+0x5d1/0xa20 net/sched/sch_hhf.c:439 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_resolve_output net/core/neighbour.c:1490 [inline] neigh_resolve_output+0x5a5/0x970 net/core/neighbour.c:1470 neigh_output include/net/neighbour.h:511 [inline] ip6_finish_output2+0x1034/0x2520 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:arch_local_irq_restore+0x35/0x60 arch/x86/include/asm/paravirt.h:768 Code: 48 b9 00 00 00 00 00 fc ff df 48 c1 ea 03 48 89 e5 48 83 ec 08 80 3c 0a 00 75 18 48 83 3d c2 56 4f 07 00 74 0c 48 89 c7 57 9d <0f> 1f 44 00 00 c9 c3 0f 0b 48 89 7d f8 48 c7 c7 50 f4 f2 88 e8 22 RSP: 0018:ffff888067fdf748 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000286 RBX: dffffc0000000000 RCX: dffffc0000000000 RDX: 1ffffffff11e5e8a RSI: 0000000000000006 RDI: 0000000000000286 RBP: ffff888067fdf750 R08: ffff8880a3f88500 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888067fdf830 R13: ffff888067fdf838 R14: ffff888067fdf830 R15: 000000000000000f free_unref_page_list+0x4f3/0x700 mm/page_alloc.c:3099 release_pages+0xd9a/0x1a50 mm/swap.c:800 __pagevec_release+0x88/0x120 mm/swap.c:820 pagevec_release include/linux/pagevec.h:88 [inline] shmem_undo_range+0xde8/0x2160 mm/shmem.c:855 shmem_truncate_range+0x27/0xa0 mm/shmem.c:977 shmem_evict_inode+0x311/0xad0 mm/shmem.c:1077 evict+0x306/0x680 fs/inode.c:571 iput_final fs/inode.c:1560 [inline] iput+0x530/0x8b0 fs/inode.c:1586 dentry_unlink_inode+0x2d9/0x400 fs/dcache.c:374 __dentry_kill+0x38b/0x600 fs/dcache.c:579 dentry_kill fs/dcache.c:686 [inline] dput+0x819/0xde0 fs/dcache.c:859 __fput+0x424/0x890 fs/file_table.c:293 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299 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:00007f662e61bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: 0000000020000000 RBX: 0000000000000006 RCX: 00000000004598e9 RDX: ffffffffffffffff RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 000000000075bfc8 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 00007f662e61c6d4 R13: 00000000004c5db4 R14: 00000000004da890 R15: 00000000ffffffff