rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=2c8c/1/0x4000000000000000 softirq=42590/42616 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=33713, q=1762 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9664 Comm: syz-executor Not tainted 6.16.0-rc5-syzkaller-01231-g96698d1898bc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_acquire+0xc9/0x360 kernel/locking/lockdep.c:5867 Code: 03 11 85 c0 0f 85 eb 00 00 00 65 48 8b 04 25 08 10 a1 92 83 b8 ec 0a 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c <8f> 44 24 30 4c 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 fa 48 c7 c7 43 RSP: 0018:ffffc90000a08b38 EFLAGS: 00000046 RAX: ffff88803066da00 RBX: 0000000000000000 RCX: 8d3b7e9b1fbbbe00 RDX: 0000000000000000 RSI: ffffffff8b7382b7 RDI: 1ffffffff3393745 RBP: ffffffff84c7ec0b R08: 0000000000000001 R09: 0000000000000000 R10: ffffc90000a08ca0 R11: fffff52000141196 R12: 0000000000000000 R13: ffffffff99c9ba28 R14: 0000000000000000 R15: 0000000000000001 FS: 000055558c4b5500(0000) GS:ffff888125d0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe03376fd58 CR3: 000000005015e000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 debug_object_activate+0xbb/0x420 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:484 [inline] enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 9b d0 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000aa9ea38 EFLAGS: 00000206 RAX: 8d3b7e9b1fbbbe00 RBX: 0000000000000000 RCX: 8d3b7e9b1fbbbe00 RDX: 0000000000000000 RSI: ffffffff8db8ee7b RDI: ffffffff8be29e00 RBP: ffffffff8172aae5 R08: 0000000000000000 R09: ffffffff8172aae5 R10: ffffc9000aa9ebf8 R11: ffffffff81ad03a0 R12: 0000000000000002 R13: ffffffff8e13f160 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 ref_tracker_alloc+0x17d/0x460 lib/ref_tracker.c:277 __netdev_tracker_alloc include/linux/netdevice.h:4344 [inline] netdev_hold include/linux/netdevice.h:4373 [inline] inetdev_init+0x211/0x500 net/ipv4/devinet.c:286 inetdev_event+0x301/0x15b0 net/ipv4/devinet.c:1591 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2266 [inline] call_netdevice_notifiers net/core/dev.c:2280 [inline] register_netdevice+0x1608/0x1ae0 net/core/dev.c:11183 wg_newlink+0x396/0x650 drivers/net/wireguard/device.c:370 rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3825 __rtnl_newlink net/core/rtnetlink.c:3942 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2551 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x759/0x8e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 __sys_sendto+0x3bd/0x520 net/socket.c:2228 __do_sys_sendto net/socket.c:2235 [inline] __se_sys_sendto net/socket.c:2231 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2231 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a9cb907bc Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007ffceb28abd0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f4a9d8e4620 RCX: 00007f4a9cb907bc RDX: 000000000000003c RSI: 00007f4a9d8e4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffceb28ac24 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f4a9d8e4670 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10496 jiffies! g33713 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=14439 rcu: rcu_preempt kthread starved for 10497 jiffies! g33713 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0x165/0x360 kernel/sched/core.c:6883 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245