rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4504/1:b..l (detected by 1, t=10502 jiffies, g=8577, q=77) task:kworker/u4:9 state:R running task stack:26320 pid: 4504 ppid: 2 flags:0x00004000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_notrace+0xd9/0x120 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+0xb57/0xe10 net/ipv6/addrconf.c:1182 addrconf_add_linklocal+0x26a/0x6c0 net/ipv6/addrconf.c:3238 addrconf_addr_gen+0x559/0x6b0 net/ipv6/addrconf.c:3369 addrconf_init_auto_addrs+0x747/0xb00 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+0xe0/0x160 net/core/dev.c:1440 linkwatch_do_dev+0x10d/0x160 net/core/link_watch.c:167 __linkwatch_run_queue+0x4b1/0x7c0 net/core/link_watch.c:213 linkwatch_event+0x48/0x50 net/core/link_watch.c:252 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 rcu: rcu_preempt kthread starved for 10543 jiffies! g8577 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:28176 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4570 Comm: syz.1.18 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__lock_acquire+0x1072/0x7d10 kernel/locking/lockdep.c:4920 Code: 48 0c 8a 8d 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 28 5b 00 00 41 01 de 83 3d 81 f4 2c 0c 00 4c 8b 7c 24 18 0f 85 f9 02 00 00 <48> 83 7c 24 70 00 0f 84 34 02 00 00 48 8b 44 24 78 48 8d 58 f8 48 RSP: 0018:ffffc900048a7640 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000f3d5c9cf RCX: 00000000966db57a RDX: 00000000aa5b5573 RSI: 00000000a87c38ea RDI: ffffffff901d10c8 RBP: ffffc900048a7890 R08: dffffc0000000000 R09: 1ffffffff203a219 R10: dffffc0000000000 R11: fffffbfff203a21a R12: 000000009707c98c R13: ffff888022e61dc0 R14: 00000000a19d95c8 R15: ffff888022e628f8 FS: 00007f0fe71616c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000058 CR3: 0000000058f9a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:103 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get_with_offset+0xff/0x320 kernel/time/timekeeping.c:874 common_hrtimer_rearm+0x5d/0x110 kernel/time/posix-timers.c:303 posixtimer_rearm+0x131/0x340 kernel/time/posix-timers.c:329 dequeue_signal+0x174/0x440 kernel/signal.c:696 get_signal+0x6fe/0x12c0 kernel/signal.c:2781 arch_do_signal_or_restart+0xe7/0x12c0 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: 0033:0x7f0fe7afdeb7 Code: 83 c8 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 RSP: 002b:00007f0fe71610e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f0fe7d78fa8 RCX: 00007f0fe7afdeb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0fe7d78fa8 RBP: 00007f0fe7d78fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0fe7d79038 R14: 00007ffe812f7a40 R15: 00007ffe812f7b28 sched: RT throttling activated hrtimer: interrupt took 994841216 ns