rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2671 jiffies s: 52073 root: 0x1/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 56 Comm: kworker/u4:4 Not tainted 6.4.0-rc5-syzkaller-00016-ga4d7d7011219 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Workqueue: netns cleanup_net RIP: 0010:fq_pie_qdisc_dequeue+0x62f/0x9c0 net/sched/sch_fq_pie.c:247 Code: 24 42 80 3c 20 00 0f 85 04 03 00 00 48 8b 85 e0 02 00 00 48 39 04 24 0f 85 52 fa ff ff 45 31 ff e9 8d fd ff ff e8 f1 2b 45 f9 <48> 8d bd 28 03 00 00 48 89 fa 48 c1 ea 03 42 0f b6 14 22 84 d2 74 RSP: 0018:ffffc90000007620 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88807ba048f0 RCX: 0000000000000100 RDX: ffff888017671dc0 RSI: ffffffff883f1a4f RDI: 0000000000000005 RBP: ffff888072a98800 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000002 R12: dffffc0000000000 R13: ffff888072a98ae0 R14: ffff888072a98af0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4999184c18 CR3: 000000000c571000 CR4: 00000000003506f0 Call Trace: dequeue_skb net/sched/sch_generic.c:292 [inline] qdisc_restart net/sched/sch_generic.c:397 [inline] __qdisc_run+0x1b2/0x1780 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3868 [inline] __dev_queue_xmit+0x2215/0x3b10 net/core/dev.c:4210 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_connected_output+0x3c2/0x550 net/core/neighbour.c:1581 neigh_output include/net/neighbour.h:544 [inline] ip6_finish_output2+0x55a/0x1560 net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline] ip6_finish_output+0x69a/0x1170 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip6_output+0x1f1/0x540 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:458 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ndisc_send_skb+0xa63/0x1850 net/ipv6/ndisc.c:508 ndisc_send_rs+0x132/0x6f0 net/ipv6/ndisc.c:718 addrconf_rs_timer+0x3f1/0x870 net/ipv6/addrconf.c:3936 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers+0x29b/0x4b0 kernel/time/timer.c:1751 __run_timers kernel/time/timer.c:2022 [inline] __run_timers kernel/time/timer.c:1995 [inline] run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x114/0x190 kernel/softirq.c:650 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:lock_acquire+0x1f5/0x520 kernel/locking/lockdep.c:5673 Code: 97 9c 7e 83 f8 01 0f 85 b9 02 00 00 9c 58 f6 c4 02 0f 85 a4 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90001577a38 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920002aef49 RCX: 1412e1d9f5811a25 RDX: 1ffff11002ece510 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff91529d07 R10: fffffbfff22a53a0 R11: 1ffffffff18f47d1 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8c7990c0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:327 [inline] rcu_read_lock include/linux/rcupdate.h:773 [inline] inet_twsk_purge+0x132/0x900 net/ipv4/inet_timewait_sock.c:292 ops_exit_list+0x125/0x170 net/core/net_namespace.c:175 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:614 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308