rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P59/1:b..l rcu: (detected by 0, t=10502 jiffies, g=9837, q=857 ncpus=2) task:kworker/u4:4 state:R running task stack:23096 pid:59 ppid:2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 unwind_next_frame+0x200f/0x2970 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 ref_tracker_alloc+0x17e/0x460 lib/ref_tracker.c:209 __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline] netdev_hold include/linux/netdevice.h:4139 [inline] dst_init+0xd9/0x460 net/core/dst.c:52 dst_alloc+0x12e/0x170 net/core/dst.c:93 ip6_dst_alloc net/ipv6/route.c:344 [inline] icmp6_dst_alloc+0x7b/0x400 net/ipv6/route.c:3306 ndisc_send_skb+0x419/0x14b0 net/ipv6/ndisc.c:493 ndisc_send_ns+0xcc/0x150 net/ipv6/ndisc.c:671 addrconf_dad_work+0xa25/0x14e0 net/ipv6/addrconf.c:4246 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: rcu_preempt kthread starved for 10528 jiffies! g9837 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:26568 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5985 Comm: syz.2.19 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:usage_skip kernel/locking/lockdep.c:2265 [inline] RIP: 0010:__bfs kernel/locking/lockdep.c:1784 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1844 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2804 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3138 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3253 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3869 [inline] RIP: 0010:__lock_acquire+0x3404/0x7c80 kernel/locking/lockdep.c:5137 Code: 00 00 00 00 00 fc ff df 4d 8b 3e 4d 8d a7 ca 00 00 00 4c 89 e0 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 f7 02 00 00 41 0f b6 04 24 <85> c0 0f 84 a1 00 00 00 83 f8 01 0f 85 a4 fd ff ff 48 8b 44 24 38 RSP: 0018:ffffc900001eff60 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff93678308 RCX: 0000000000000008 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff90711d70 RBP: ffffc900001f01a8 R08: ffffc900001f0137 R09: 0000000000000000 R10: ffffc900001f0100 R11: fffff5200003e027 R12: ffffffff9071481a R13: 1ffffffff26cf063 R14: ffffffff93678318 R15: ffffffff90714750 FS: 00005555656e6500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34263fff CR3: 0000000022704000 CR4: 00000000003506e0 Call Trace: lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 seqcount_lockdep_reader_access+0xb5/0x180 include/linux/seqlock.h:102 read_seqbegin include/linux/seqlock.h:893 [inline] zone_span_seqbegin include/linux/memory_hotplug.h:134 [inline] page_outside_zone_boundaries mm/page_alloc.c:448 [inline] bad_range+0x5f/0x280 mm/page_alloc.c:467 expand+0x79/0x2d0 mm/page_alloc.c:1415 __rmqueue_smallest mm/page_alloc.c:1597 [inline] __rmqueue mm/page_alloc.c:2123 [inline] rmqueue_bulk mm/page_alloc.c:2149 [inline] __rmqueue_pcplist+0xb45/0x1160 mm/page_alloc.c:2722 rmqueue_pcplist mm/page_alloc.c:2764 [inline] rmqueue mm/page_alloc.c:2801 [inline] get_page_from_freelist+0x69d/0x19f0 mm/page_alloc.c:3188 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2e0 mm/slub.c:2081 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] kmem_cache_alloc_node+0x1ea/0x330 mm/slub.c:3540 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1284 [inline] new_skb drivers/block/aoe/aoecmd.c:66 [inline] aoecmd_cfg_pkts drivers/block/aoe/aoecmd.c:430 [inline] aoecmd_cfg+0x29c/0xa00 drivers/block/aoe/aoecmd.c:1374 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 6a 5f f6 f6 48 89 df e8 82 31 f7 f6 e8 5d d8 1a f7 fb bf 01 00 00 00 52 53 ea f6 65 8b 05 43 9a 92 75 85 c0 74 02 5b c3 e8 20 80 8f RSP: 0018:ffffc90003537c78 EFLAGS: 00000286 RAX: 1da867cf7b7a7300 RBX: ffff88807ac35c80 RCX: 1da867cf7b7a7300 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001 RBP: ffff88807ac35f18 R08: ffffffff8e4a212f R09: 1ffffffff1c94425 R10: dffffc0000000000 R11: fffffbfff1c94426 R12: 1ffff1100f586be3 R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000000000000 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x11f5/0x1400 kernel/signal.c:2905 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fdb5b18f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcaa0f86c8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fdb5b3e5fa0 RCX: 00007fdb5b18f749 RDX: 0000200000000240 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fdb5b213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdb5b3e5fa0 R14: 00007fdb5b3e5fa0 R15: 0000000000000004 sched: RT throttling activated