rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=4cb/1/0x4000000000000000 softirq=52787/52788 fqs=0 (t=10502 jiffies g=71649 q=1448) rcu: rcu_preempt kthread starved for 10503 jiffies! g71649 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:27536 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145 kthread+0x42e/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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8349 Comm: kworker/u4:15 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: wg-kex-wg0 wg_packet_handshake_send_worker RIP: 0010:poke_int3_handler+0xc0/0x1c0 arch/x86/kernel/alternative.c:1550 Code: d6 ff 4c 39 d1 4c 0f 43 c8 31 c0 48 d1 ee 75 cd eb b6 48 85 c0 0f 84 fb 00 00 00 0f b6 70 08 48 01 f1 0f b6 70 09 44 8d 46 90 <41> 83 f8 10 0f 83 86 00 00 00 83 e6 0f 48 63 40 04 40 80 fe 0b 77 RSP: 0018:ffffc900037af548 EFLAGS: 00000086 RAX: ffffffff8efd6ae0 RBX: ffffc900037af568 RCX: ffffffff815d591d RDX: ffffffff815d5919 RSI: 00000000000000e9 RDI: ffffc900037af568 RBP: 0000000000000000 R08: 0000000000000079 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32123ffc CR3: 0000000042f64000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: exc_int3+0xa/0x70 arch/x86/kernel/traps.c:681 asm_exc_int3+0x35/0x40 arch/x86/include/asm/idtentry.h:605 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline] RIP: 0010:trace_lock_release include/trace/events/lock.h:58 [inline] RIP: 0010:lock_release+0x79/0x8a0 kernel/locking/lockdep.c:5634 Code: 48 c7 44 24 70 a0 58 5d 81 4c 8d 64 24 60 49 c1 ec 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4b 89 04 2c 43 c7 44 2c 08 f8 f3 f3 f3 cc <1f> 44 00 00 65 8b 1d 34 bc a4 7e 83 fb 08 0f 83 4e 05 00 00 89 d8 RSP: 0018:ffffc900037af640 EFLAGS: 00000a06 RAX: f2f2f2f8f1f1f1f1 RBX: ffff888060650c28 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff8533b3f4 RDI: ffff888060650c98 RBP: ffffc900037af748 R08: ffffffff901cb1bf R09: 1ffffffff2039637 R10: dffffc0000000000 R11: fffffbfff2039638 R12: 1ffff920006f5ed4 R13: dffffc0000000000 R14: ffffc900037afb01 R15: ffff888060650b30 up_write+0x29/0x410 kernel/locking/rwsem.c:1603 wg_noise_handshake_create_initiation+0x7b4/0x920 drivers/net/wireguard/noise.c:577 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline] wg_packet_handshake_send_worker+0x18b/0x360 drivers/net/wireguard/send.c:51 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 NMI backtrace for cpu 0 CPU: 0 PID: 15013 Comm: syz.8.1453 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 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_dump_cpu_stacks+0x22d/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31f/0x5f0 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x6ec/0x1120 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:2021 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+0x4b0/0xb60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x397/0x8b0 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+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:67 Code: 44 89 e1 80 e1 07 38 c1 0f 8c 1c fd ff ff 4c 89 e7 e8 61 e0 88 00 e9 0f fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8b 07 00 00 cc cc 00 00 cc cc 00 00 cc cc 31 c0 81 ff 03 00 00 40 0f RSP: 0018:ffffc900000073e8 EFLAGS: 00000202 RAX: ffffffff89e000ca RBX: ffffc90000007488 RCX: 1ffff92000000e01 RDX: ffffc90002fbff58 RSI: ffffffff8df9df30 RDI: ffffc90002fbff50 RBP: ffffc90002fb8000 R08: 0000000000000009 R09: 0000000000000017 R10: dffffc0000000000 R11: fffff52000000e9d R12: 1ffffffff1d2c045 R13: 1ffffffff1d2c045 R14: ffffc90002fc0000 R15: ffffc90002fbff50 deref_stack_reg arch/x86/kernel/unwind_orc.c:360 [inline] unwind_next_frame+0x970/0x1cf0 arch/x86/kernel/unwind_orc.c:539 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x92/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238 dst_alloc+0x101/0x160 net/core/dst.c:88 ip6_dst_alloc net/ipv6/route.c:342 [inline] icmp6_dst_alloc+0x7e/0x470 net/ipv6/route.c:3269 ndisc_send_skb+0x3d1/0x1410 net/ipv6/ndisc.c:493 addrconf_rs_timer+0x367/0x640 net/ipv6/addrconf.c:3959 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1699 [inline] __run_timers+0x56c/0x810 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x336/0x830 kernel/softirq.c:576 do_softirq+0x142/0x210 kernel/softirq.c:477 __local_bh_enable_ip+0x180/0x1c0 kernel/softirq.c:401 rcu_read_unlock_bh include/linux/rcupdate.h:810 [inline] ip_finish_output2+0xd6e/0x10e0 net/ipv4/ip_output.c:229 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip_output+0x2ba/0x3e0 net/ipv4/ip_output.c:434 dst_output include/net/dst.h:452 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x1207/0x1ce0 net/ipv4/ip_output.c:538 __tcp_transmit_skb+0x1ca3/0x31e0 net/ipv4/tcp_output.c:1404 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline] tcp_write_xmit+0x1a90/0x65c0 net/ipv4/tcp_output.c:2718 tcp_sendmsg_locked+0x1ebd/0x3330 net/ipv4/tcp.c:1413 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1460 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2446 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2500 __sys_sendmsg net/socket.c:2529 [inline] __do_sys_sendmsg net/socket.c:2538 [inline] __se_sys_sendmsg+0x1b7/0x2a0 net/socket.c:2536 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fad074e9e59 Code: 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 01 48 RSP: 002b:00007fad05743028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fad07762fa0 RCX: 00007fad074e9e59 RDX: 00000000000052cc RSI: 0000200000000040 RDI: 0000000000000005 RBP: 00007fad0757fe6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fad07763038 R14: 00007fad07762fa0 R15: 00007fff80cfa9c8