rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P57/2:b..l rcu: (detected by 0, t=10502 jiffies, g=19281, q=442 ncpus=2) task:kworker/u8:4 state:R running task stack:23416 pid:57 tgid:57 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7364 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0xe1/0x130 kernel/softirq.c:457 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:912 [inline] __dev_queue_xmit+0x1f8e/0x38f0 net/core/dev.c:4910 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246 dst_output include/net/dst.h:470 [inline] NF_HOOK+0x177/0x4f0 include/linux/netfilter.h:318 mld_sendpack+0x8b4/0xe40 net/ipv6/mcast.c:1855 ipv6_mc_dad_complete+0x88/0x540 net/ipv6/mcast.c:2279 addrconf_dad_completed+0x8a7/0xe60 net/ipv6/addrconf.c:4352 addrconf_dad_work+0xc5e/0x14c0 net/ipv6/addrconf.c:-1 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10435 jiffies! g19281 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] schedule+0x164/0x360 kernel/sched/core.c:7277 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: 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 03/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 5b 9f 02 e9 93 f3 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 b3 70 2b 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8ea07dc0 EFLAGS: 00000242 RAX: 0000000000109dfd RBX: ffffffff819ad70a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8e31177c RDI: ffffffff8c4a9e60 RBP: ffffffff8ea07eb0 R08: ffff8880b86339db R09: 1ffff110170c673b R10: dffffc0000000000 R11: ffffed10170c673c R12: 0000000000000000 R13: 1ffffffff1d525d8 R14: 0000000000000000 R15: 1ffffffff1d525d8 FS: 0000000000000000(0000) GS:ffff888124dec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000080 CR3: 00000000788fc000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 rest_init+0x2de/0x300 init/main.c:762 start_kernel+0x38a/0x3e0 init/main.c:1220 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147