rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9672/2:b..l P1443/4:b..l P37/1:b..l P8553/6:b..l rcu: (detected by 1, t=10502 jiffies, g=66101, q=311 ncpus=2) task:kworker/u8:3 state:R running task stack:21952 pid:8553 tgid:8553 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5402 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7204 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7528 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:__local_bh_enable_ip+0x2a/0x2b0 kernel/softirq.c:260 Code: f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 89 f3 65 8b 05 19 73 ed 10 a9 ff ff ff 7f 74 05 45 31 ff eb 0b 9c 41 5f 41 c1 ef 09 <41> 83 e7 01 65 8b 05 fb 72 ed 10 a9 00 00 0f 00 0f 85 91 01 00 00 RSP: 0018:ffffc90005b9f3f0 EFLAGS: 00000202 RAX: 0000000080000000 RBX: 0000000000000200 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000200 RDI: ffffffff88fd9226 RBP: 0000000000000000 R08: ffffffff8f8d03f7 R09: 1ffffffff1f1a07e R10: dffffc0000000000 R11: fffffbfff1f1a07f R12: 0000000000000090 R13: ffffffff88fd9226 R14: 0000000000000820 R15: 0000000000000001 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x1aa/0x7d0 net/core/skbuff.c:697 alloc_skb include/linux/skbuff.h:1382 [inline] nlmsg_new include/net/netlink.h:1055 [inline] __neigh_notify+0x15c/0x310 net/core/neighbour.c:3573 neigh_notify net/core/neighbour.c:3595 [inline] neigh_cleanup_and_release+0xc2/0x2d0 net/core/neighbour.c:119 neigh_remove_one+0x46d/0x4c0 net/core/neighbour.c:249 neigh_forced_gc net/core/neighbour.c:280 [inline] neigh_alloc net/core/neighbour.c:512 [inline] ___neigh_create+0x4ad/0x2360 net/core/neighbour.c:655 ip6_finish_output2+0x729/0x1430 net/ipv6/ip6_output.c:128 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:488 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xd0b/0x1670 net/ipv6/ndisc.c:512 ndisc_send_ns+0xd7/0x160 net/ipv6/ndisc.c:671 addrconf_dad_work+0xbea/0x1680 net/ipv6/addrconf.c:4309 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318 process_scheduled_works kernel/workqueue.c:3401 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3482 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 task:kworker/1:1 state:D stack:24272 pid:37 tgid:37 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient neigh_managed_work Call Trace: context_switch kernel/sched/core.c:5402 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7204 __schedule_loop kernel/sched/core.c:7283 [inline] schedule_rtlock+0x30/0x70 kernel/sched/core.c:7362 rtlock_slowlock_locked+0x3638/0x3c80 kernel/locking/rtmutex.c:1891 rtlock_slowlock kernel/locking/rtmutex.c:1918 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57 spin_lock_bh include/linux/spinlock_rt.h:90 [inline] neigh_managed_work+0x4e/0x250 net/core/neighbour.c:1669 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318 process_scheduled_works kernel/workqueue.c:3401 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3482 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 task:kworker/u8:12 state:R running task stack:19416 pid:1443 tgid:1443 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker Call Trace: context_switch kernel/sched/core.c:5402 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7204 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7528 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5874 Code: ff ff ff e8 c1 51 8f 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 fb 7b d4 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d d8 85 ef RSP: 0000:ffffc90006767378 EFLAGS: 00000286 RAX: 0d4a70170bab8a00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 000000009349cfab RSI: ffffffff8d8b03aa RDI: ffffffff8baa2980 RBP: ffffffff8176c406 R08: ffffffff8176c406 R09: ffffffff8dfcac60 R10: ffffc900067674d8 R11: ffffffff81b02a50 R12: 0000000000000002 R13: ffffffff8dfcac60 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_dst_trace_buffer+0x108/0x5b0 net/core/dst.c:102 dst_hold include/net/dst.h:261 [inline] dst_cache_per_cpu_dst_set+0xe4/0x1c0 net/core/dst_cache.c:34 dst_cache_set_ip6+0x40a/0x580 net/core/dst_cache.c:131 send6+0x533/0x910 drivers/net/wireguard/socket.c:147 wg_socket_send_skb_to_peer+0x128/0x200 drivers/net/wireguard/socket.c:177 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x203/0x350 drivers/net/wireguard/send.c:51 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318 process_scheduled_works kernel/workqueue.c:3401 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3482 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 task:syz-executor state:R running task stack:21040 pid:9672 tgid:9672 ppid:9659 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5402 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7204 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7385 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 class_preempt_destructor include/linux/preempt.h:468 [inline] __migrate_enable include/linux/sched.h:2503 [inline] migrate_enable include/linux/sched.h:2543 [inline] rt_spin_unlock+0xf0/0x200 kernel/locking/spinlock_rt.c:81 spin_unlock include/linux/spinlock_rt.h:109 [inline] copy_pte_range mm/memory.c:1347 [inline] copy_pmd_range+0x49f7/0x5550 mm/memory.c:1408 copy_pud_range mm/memory.c:1445 [inline] copy_p4d_range mm/memory.c:1469 [inline] copy_page_range+0xb3f/0x1150 mm/memory.c:1555 dup_mmap+0xf5a/0x1d70 mm/mmap.c:1840 dup_mm kernel/fork.c:1542 [inline] copy_mm+0x11a/0x480 kernel/fork.c:1594 copy_process+0x1e30/0x43d0 kernel/fork.c:2291 kernel_clone+0x2d7/0x940 kernel/fork.c:2749 __do_sys_clone kernel/fork.c:2890 [inline] __se_sys_clone kernel/fork.c:2874 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2874 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb27dff58d2 RSP: 002b:00007ffd563adb70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd563adb70 RCX: 00007fb27dff58d2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd563adcfc R08: 0000000000000000 R09: 0000000000000001 R10: 0000555571d8f7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000000b8dab R15: 00007ffd563add50 rcu: rcu_preempt kthread timer wakeup didn't happen for 10301 jiffies! g66101 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=37549 rcu: rcu_preempt kthread starved for 10302 jiffies! g66101 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27672 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5402 [inline] __schedule+0x16f9/0x5500 kernel/sched/core.c:7204 __schedule_loop kernel/sched/core.c:7283 [inline] schedule+0x164/0x360 kernel/sched/core.c:7298 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11b0 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 6b 5f 02 c3 cc cc cc cc 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 43 73 19 00 fb f4 3c cb 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8dc07dc0 EFLAGS: 00000246 RAX: 00000000003df4af RBX: ffffffff8199a80a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d64b655 RDI: ffffffff8baa2980 RBP: ffffffff8dc07eb0 R08: ffff8880b8633d5b R09: 1ffff110170c67ab R10: dffffc0000000000 R11: ffffed10170c67ac R12: 0000000000000000 R13: 1ffffffff1b9fde8 R14: 0000000000000000 R15: 1ffffffff1b9fde8 FS: 0000000000000000(0000) GS:ffff888125ecd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f57ff55fd48 CR3: 000000004185e000 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:717 start_kernel+0x392/0x3e0 init/main.c:1175 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/0x157