rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=b394/1/0x4000000000000000 softirq=87519/87520 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11488/1:b..l (detected by 0, t=10502 jiffies, g=136325, q=44 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 22137 Comm: syz.2.4991 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:_raw_spin_lock_irqsave+0xe6/0x100 kernel/locking/spinlock.c:162 Code: 48 c7 04 24 0e 36 e0 45 4b c7 04 27 00 00 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 48 75 10 4c 89 f0 48 8d 65 e0 5b 41 5c <41> 5e 41 5f 5d c3 e8 ef e5 f5 ff 66 2e 0f 1f 84 00 00 00 00 00 0f RSP: 0018:ffffc900001e0ca0 EFLAGS: 00000046 RAX: 0000000000000806 RBX: ffff88802dd8c340 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900001e0ba0 RBP: ffffc900001e0cb0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200003c174 R12: ffffffff96e7ac88 R13: ffff88802dd8c340 R14: 0000000000000806 R15: 1ffff9200003c184 FS: 00007f7c53f3a6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7c53f39ff8 CR3: 000000007e2c7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_object_activate+0x68/0x4f0 lib/debugobjects.c:747 debug_hrtimer_activate kernel/time/hrtimer.c:448 [inline] debug_activate kernel/time/hrtimer.c:502 [inline] enqueue_hrtimer+0x37/0x410 kernel/time/hrtimer.c:1097 __run_hrtimer kernel/time/hrtimer.c:1768 [inline] __hrtimer_run_queues+0x63e/0xc90 kernel/time/hrtimer.c:1815 hrtimer_interrupt+0x399/0x980 kernel/time/hrtimer.c:1877 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 3f 89 1e f7 65 8b 05 b0 3a c8 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90003eb7920 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: 3054a25baeca3a00 RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 0000000000000001 RBP: ffffc90003eb79b0 R08: ffffffff90b10247 R09: 1ffffffff2162048 R10: dffffc0000000000 R11: fffffbfff2162049 R12: dffffc0000000000 R13: ffff8880b8e2a5c0 R14: ffff8880b8e2a5c0 R15: 1ffff920007d6f24 clock_was_set+0x17c/0x8d0 kernel/time/hrtimer.c:984 timekeeping_inject_offset+0x5cc/0x670 kernel/time/timekeeping.c:1395 do_adjtimex+0x45a/0xa00 kernel/time/timekeeping.c:2444 do_clock_adjtime kernel/time/posix-timers.c:1155 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1167 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1158 [inline] __x64_sys_clock_adjtime+0x240/0x320 kernel/time/posix-timers.c:1158 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7c52f9e019 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:00007f7c53f3a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f7c53226090 RCX: 00007f7c52f9e019 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000 RBP: 00007f7c5303500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7c53226128 R14: 00007f7c53226090 R15: 00007ffe959dafb8 task:kworker/u4:40 state:R running task stack:20528 pid:11488 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6732 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6756 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x10d/0x120 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock kernel/sched/wait.c:140 [inline] __wake_up_sync_key+0x128/0x190 kernel/sched/wait.c:208 sock_def_readable+0x15b/0x280 net/core/sock.c:3325 __netlink_sendskb net/netlink/af_netlink.c:1264 [inline] netlink_broadcast_deliver net/netlink/af_netlink.c:1399 [inline] do_one_broadcast net/netlink/af_netlink.c:1484 [inline] netlink_broadcast+0xd19/0x10f0 net/netlink/af_netlink.c:1524 uevent_net_broadcast_tagged lib/kobject_uevent.c:372 [inline] kobject_uevent_net_broadcast+0x497/0x530 lib/kobject_uevent.c:412 kobject_uevent_env+0x555/0x890 lib/kobject_uevent.c:608 netdev_queue_add_kobject net/core/net-sysfs.c:1675 [inline] netdev_queue_update_kobjects+0x238/0x480 net/core/net-sysfs.c:1716 register_queue_kobjects net/core/net-sysfs.c:1777 [inline] netdev_register_kobject+0x273/0x320 net/core/net-sysfs.c:2017 register_netdevice+0x133a/0x1b80 net/core/dev.c:10243 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x353/0x400 drivers/net/netdevsim/netdev.c:365 __nsim_dev_port_add+0x75b/0xbc0 drivers/net/netdevsim/dev.c:1396 nsim_dev_port_add_all+0x35/0xe0 drivers/net/netdevsim/dev.c:1454 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1506 [inline] nsim_dev_reload_up+0x47a/0x770 drivers/net/netdevsim/dev.c:988 devlink_reload+0x2c1/0x690 net/devlink/leftover.c:4479 devlink_pernet_pre_exit+0x122/0x280 net/devlink/leftover.c:12503 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x58e/0xba0 net/core/net_namespace.c:620 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10502 jiffies! g136325 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:27888 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 21199 Comm: kworker/u4:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0x1148/0x1250 kernel/smp.c:998 Code: 41 8b 1f 89 de 83 e6 01 31 ff e8 73 ff 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 0a e8 ff fb 0a 00 e9 34 ff ff ff f3 90 <41> 0f b6 04 1c 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 17 ff ff ff RSP: 0018:ffffc90003b17800 EFLAGS: 00000293 RAX: ffffffff81773243 RBX: dffffc0000000000 RCX: ffff8880283a0000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003b17960 R08: ffffffff90b10247 R09: 1ffffffff2162048 R10: dffffc0000000000 R11: fffffbfff2162049 R12: 1ffff110171e8219 R13: ffff8880b8e3bdc0 R14: 0000000000000001 R15: ffff8880b8f410c8 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7c53f3ad58 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1574 [inline] text_poke_bp_batch+0x2b7/0x850 arch/x86/kernel/alternative.c:1774 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 toggle_allocation_gate+0xba/0x470 mm/kfence/core.c:821 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295