rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10500 ticks this GP) idle=188c/0/0x3 softirq=35445/35445 fqs=5249 rcu: hardirqs softirqs csw/system rcu: number: 7985 0 0 rcu: cputime: 142 52346 0 ==> 52500(ms) rcu: (t=10502 jiffies g=30261 q=2582 ncpus=2) CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:fq_flow_add_tail net/sched/sch_fq.c:208 [inline] RIP: 0010:fq_dequeue+0xde9/0x2650 net/sched/sch_fq.c:698 Code: ed bd 8a f8 49 89 1f e9 92 00 00 00 e8 90 4b 27 f8 e9 88 00 00 00 e8 86 4b 27 f8 48 b8 00 00 00 00 00 fc ff df 41 80 3c 06 00 <74> 08 48 89 df e8 bd bd 8a f8 48 8b 44 24 10 48 89 03 4c 8b 74 24 RSP: 0018:ffffc90000007040 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff888024171348 RCX: ffffffff8de95100 RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000004 RBP: ffffc900000071d0 R08: ffffffff8fa39737 R09: 1ffffffff1f472e6 R10: dffffc0000000000 R11: ffffffff8167ba50 R12: 1ffff1100f134e51 R13: ffff8880789a7288 R14: 1ffff1100482e269 R15: 1ffff1100482e269 FS: 0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbc1d7746a0 CR3: 00000000290ca000 CR4: 00000000003526f0 Call Trace: dequeue_skb net/sched/sch_generic.c:294 [inline] qdisc_restart net/sched/sch_generic.c:399 [inline] __qdisc_run+0x23c/0x15f0 net/sched/sch_generic.c:417 __dev_xmit_skb net/core/dev.c:4183 [inline] __dev_queue_xmit+0x1056/0x3b50 net/core/dev.c:4691 dev_queue_xmit include/linux/netdevice.h:3361 [inline] neigh_hh_output include/net/neighbour.h:531 [inline] neigh_output include/net/neighbour.h:545 [inline] ip6_finish_output2+0x11bc/0x16a0 net/ipv6/ip6_output.c:141 ip6_send_skb+0x1d5/0x390 net/ipv6/ip6_output.c:1984 icmp6_send+0x12c6/0x1940 net/ipv6/icmp.c:634 __icmpv6_send include/linux/icmpv6.h:28 [inline] icmpv6_send include/linux/icmpv6.h:49 [inline] ip6_link_failure+0x3b/0x4c0 net/ipv6/route.c:2843 dst_link_failure include/net/dst.h:429 [inline] ndisc_error_report+0x118/0x160 net/ipv6/ndisc.c:732 neigh_invalidate+0x232/0x460 net/core/neighbour.c:1082 neigh_timer_handler+0x949/0x1150 net/core/neighbour.c:1173 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 13 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 37 0e 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c2 RAX: 507221be6bd2db00 RBX: ffffffff819683f8 RCX: 507221be6bd2db00 RDX: 0000000000000001 RSI: ffffffff8d9b8bbd RDI: ffffffff8be33880 RBP: ffffffff8de07eb8 R08: ffff8880b8632f9b R09: 1ffff110170c65f3 R10: dffffc0000000000 R11: ffffed10170c65f4 R12: ffffffff8fa39730 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a20 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:744 start_kernel+0x3a9/0x410 init/main.c:1097 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147