rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=64d/1/0x4000000000000002 softirq=10515/10516 fqs=5207 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4967/1:b..l (detected by 1, t=10502 jiffies, g=14641, q=179053) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5390 Comm: syz.1.33 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:debug_lockdep_rcu_enabled+0x9/0x30 kernel/rcu/update.c:280 Code: 20 26 2b 8a 48 c7 c6 a0 4a 2b 8a e8 f1 0a f5 ff 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 31 c0 83 3d fb 75 cd 03 00 <74> 1d 83 3d 72 a8 cd 03 00 74 14 65 48 8b 0d 24 01 46 76 31 c0 83 RSP: 0018:ffffc90000007320 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff8880b90351c8 RCX: ffff88801dc01dc0 RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffc900000074d7 R09: ffffc900000074a0 R10: dffffc0000000000 R11: fffff52000000e9b R12: dffffc0000000000 R13: ffffc90000007506 R14: ffffffff8c125da0 R15: dffffc0000000000 FS: 00005555742c7500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e563fff CR3: 000000002abdd000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:104 [inline] rcu_read_lock_held+0x6/0x40 kernel/rcu/update.c:309 perf_get_guest_cbs include/linux/perf_event.h:1274 [inline] perf_misc_flags+0x56/0x1b0 arch/x86/events/core.c:2961 perf_prepare_sample+0x132/0x1cd0 kernel/events/core.c:7622 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_swevent_overflow kernel/events/core.c:9591 [inline] perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 12 f2 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc90000007b00 EFLAGS: 00000206 RAX: 4d0262eb48d7c400 RBX: 1ffff92000000f64 RCX: 4d0262eb48d7c400 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f980 RBP: ffffc90000007bd8 R08: ffff8880b903b30b R09: 1ffff11017207661 R10: dffffc0000000000 R11: ffffed1017207662 R12: ffffffff8c322f00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4f2/0xb70 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 2f 8a 8c f7 65 8b 05 d0 97 3c 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000120fb60 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 4d0262eb48d7c400 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: 0000000000000001 RBP: ffffc9000120fbf8 R08: ffff8880b903b30b R09: 1ffff11017207661 R10: dffffc0000000000 R11: ffffed1017207662 R12: dffffc0000000000 R13: ffff88805725f028 R14: ffffffff96582a98 R15: 1ffff92000241f6c __debug_check_no_obj_freed lib/debugobjects.c:982 [inline] debug_check_no_obj_freed+0x515/0x530 lib/debugobjects.c:1003 slab_free_hook mm/slub.c:1685 [inline] slab_free_freelist_hook+0x8b/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kmem_cache_free+0x8f/0x210 mm/slub.c:3520 __dentry_kill+0x4ef/0x650 fs/dcache.c:600 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xd8/0x1a0 fs/dcache.c:893 __fput+0x5ee/0x930 fs/file_table.c:319 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f85efd4de79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdf8cdc168 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f85effbada0 RCX: 00007f85efd4de79 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f85effbada0 R08: 00007f85effb9038 R09: 0000000000000000 R10: 000000000003fde0 R11: 0000000000000246 R12: 000000000001f6ef R13: 00007f85effb8fac R14: 000000000001f3e1 R15: 00007ffdf8cdc270 task:kworker/0:24 state:R running task stack:23920 pid: 4967 ppid: 2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6596 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __local_bh_enable_ip+0x147/0x1c0 kernel/softirq.c:408 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline] ip6_finish_output2+0x1127/0x1510 net/ipv6/ip6_output.c:131 dst_output include/net/dst.h:452 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ndisc_send_skb+0xc2a/0x1500 net/ipv6/ndisc.c:513 ndisc_send_ns+0x648/0x850 net/ipv6/ndisc.c:655 addrconf_dad_work+0xa63/0x1540 net/ipv6/addrconf.c:4198 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287