rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P144/1:b..l (detected by 1, t=10502 jiffies, g=8341, q=434) task:kworker/u4:1 state:R running task stack:24064 pid: 144 ppid: 2 flags:0x00004000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 preempt_schedule_notrace+0xca/0x110 kernel/sched/core.c:6650 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124 trace_kmalloc include/trace/events/kmem.h:46 [inline] kmem_cache_alloc_trace+0x132/0x2a0 mm/slub.c:3251 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] sctp_inet6addr_event+0x37b/0x730 net/sctp/ipv6.c:86 notifier_call_chain kernel/notifier.c:83 [inline] atomic_notifier_call_chain+0x15d/0x280 kernel/notifier.c:198 ipv6_add_addr+0xb30/0xde0 net/ipv6/addrconf.c:1182 addrconf_add_linklocal+0x280/0x6b0 net/ipv6/addrconf.c:3238 addrconf_addr_gen+0x4ee/0x620 net/ipv6/addrconf.c:3369 addrconf_init_auto_addrs+0x6d5/0xa80 net/ipv6/addrconf.c:-1 addrconf_notify+0xa6b/0xf00 net/ipv6/addrconf.c:3662 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 netdev_state_change+0xd2/0x140 net/core/dev.c:1440 linkwatch_do_dev+0x10d/0x160 net/core/link_watch.c:167 __linkwatch_run_queue+0x4a9/0x7b0 net/core/link_watch.c:213 linkwatch_event+0x48/0x50 net/core/link_watch.c:252 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 process_scheduled_works kernel/workqueue.c:2373 [inline] worker_thread+0xdca/0x12a0 kernel/workqueue.c:2459 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 10540 jiffies! g8341 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:28032 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 4402 Comm: syz.1.23 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/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_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 5e bd a9 f7 48 89 df e8 26 92 aa f7 e8 c1 2b cb f7 fb bf 01 00 00 00 76 b5 9e f7 65 8b 05 07 b3 4f 76 85 c0 74 02 5b c3 e8 b4 bd 4d RSP: 0018:ffffc900037bfbc0 EFLAGS: 00000282 RAX: 02a9d0962a07f900 RBX: ffff88807e2f6f00 RCX: 02a9d0962a07f900 RDX: dffffc0000000000 RSI: ffffffff8a0b18a0 RDI: 0000000000000001 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100fc5ede1 R10: ffffed100fc5ede1 R11: 1ffff1100fc5ede0 R12: ffff88807e2f6f00 R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004 spin_unlock_irq include/linux/spinlock.h:414 [inline] get_signal+0x11d6/0x12c0 kernel/signal.c:2903 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 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: 0033:0x7f61e0401fc9 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:00007ffe4d8e3b48 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f61e0658fa0 RCX: 00007f61e0401fc9 RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f61e0484f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f61e0658fa0 R14: 00007f61e0658fa0 R15: 0000000000000004 sched: RT throttling activated