rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=077c/1/0x4000000000000000 softirq=35477/35481 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9197/1:b..l P5784/1:b..l rcu: (detected by 1, t=10506 jiffies, g=40173, q=904 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9347 Comm: syz.4.759 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:_raw_spin_lock_irqsave+0x4f/0x60 kernel/locking/spinlock.c:166 Code: 8d 7e 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 74 24 10 e8 c0 42 f6 f5 48 83 c4 08 4c 89 f7 e8 04 e4 f6 f5 48 89 d8 <5b> 41 5e e9 74 d2 64 f5 cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 RSP: 0018:ffffc90000007d28 EFLAGS: 00000046 RAX: 0000000000000096 RBX: 0000000000000096 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007ca0 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f94 R12: ffffffff9a6ad588 R13: dffffc0000000000 R14: ffffffff9a6ad590 R15: 0000000000000000 FS: 00007f25068d56c0(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000004460f000 CR4: 0000000000350ef0 Call Trace: debug_object_activate+0x83/0x580 lib/debugobjects.c:835 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] enqueue_hrtimer+0xa9/0x2c0 kernel/time/hrtimer.c:1109 __run_hrtimer kernel/time/hrtimer.c:1946 [inline] __hrtimer_run_queues+0x4d2/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 3d e7 f6 f5 f7 c3 00 02 00 00 74 05 e8 30 7d 22 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 14 68 e8 f5 65 8b 05 0d c0 8d 07 85 c0 74 18 5b 41 5e e9 dc d0 RSP: 0018:ffffc90003cd7d28 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000202 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8dfa6837 RDI: 0000000000000001 RBP: ffffc90003cd7e30 R08: ffffffff9030b6f7 R09: 1ffffffff20616de R10: dffffc0000000000 R11: fffffbfff20616df R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9a48d818 R15: ffffc90003cd7e60 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline] do_settimeofday64+0x336/0x570 kernel/time/timekeeping.c:1584 __do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline] __x64_sys_clock_settime+0x253/0x2a0 kernel/time/posix-timers.c:1108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f250599cdd9 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:00007f25068d5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f2505c16090 RCX: 00007f250599cdd9 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f2505a32d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2505c16128 R14: 00007f2505c16090 R15: 00007ffede7f5598 task:kworker/0:4 state:R running task stack:25912 pid:5784 tgid:5784 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x760 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 e1 11 07 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 cb 7c 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 9b 8d 6e ff cc 48 8d 3d 58 61 92 RSP: 0018:ffffc90004f27940 EFLAGS: 00000282 RAX: e9fd656171652300 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 0000000073768838 RSI: ffffffff8e219b45 RDI: ffffffff8c28af60 RBP: ffffffff89cbca9d R08: ffffffff89cbca9d R09: ffffffff8e95cd60 R10: dffffc0000000000 R11: fffffbfff20616df R12: 0000000000000002 R13: ffffffff8e95cd60 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] gc_worker+0x281/0x1290 net/netfilter/nf_conntrack_core.c:1543 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 task:syz-executor state:R running task stack:23536 pid:9197 tgid:9197 ppid:9183 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x760 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_lock_acquire include/linux/rcupdate.h:300 [inline] RIP: 0010:rcu_read_lock include/linux/rcupdate.h:838 [inline] RIP: 0010:class_rcu_constructor include/linux/rcupdate.h:1181 [inline] RIP: 0010:unwind_next_frame+0xa6/0x2550 arch/x86/kernel/unwind_orc.c:495 Code: c6 1b 00 00 41 8b 06 85 c0 0f 84 4e 02 00 00 89 84 24 8c 00 00 00 4c 89 bc 24 90 00 00 00 e8 71 9c 34 00 4c 8d 3d 00 00 00 00 <48> c7 c7 60 cd 95 8e 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 RSP: 0018:ffffc90002fa68b8 EFLAGS: 00000283 RAX: 0000000000000001 RBX: ffffffff897222f2 RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: ffffffff897222f2 RDI: ffffc90002fa6988 RBP: dffffc0000000000 R08: ffffc90002fa6a50 R09: 0000000000000010 R10: dffffc0000000000 R11: ffffffff81b0ebd0 R12: ffffc90002fa69c0 R13: 1ffff920005f4d31 R14: ffffc90002fa6988 R15: ffffffff8176f256 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6250 [inline] kfree+0x1c5/0x640 mm/slub.c:6565 kobject_uevent_env+0x378/0x9e0 lib/kobject_uevent.c:643 rx_queue_add_kobject net/core/net-sysfs.c:1265 [inline] net_rx_queue_update_kobjects+0x3e5/0x740 net/core/net-sysfs.c:1307 register_queue_kobjects net/core/net-sysfs.c:2099 [inline] netdev_register_kobject+0x21f/0x310 net/core/net-sysfs.c:2347 register_netdevice+0x1456/0x1ec0 net/core/dev.c:11420 ip6gre_newlink_common+0x403/0x5b0 net/ipv6/ip6_gre.c:1966 ip6gre_newlink+0x228/0x350 net/ipv6/ip6_gre.c:1999 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3864 __rtnl_newlink net/core/rtnetlink.c:3995 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4110 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6996 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x672/0x710 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff0dcd5d60e RSP: 002b:00007ffc3dc7e6d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000555575b3a500 RCX: 00007ff0dcd5d60e RDX: 0000000000000054 RSI: 00007ff0ddb44670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffc3dc7e754 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007ff0ddb44670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10506 jiffies! g40173 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:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 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: 1 UID: 0 PID: 6012 Comm: kworker/u8:11 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xfd4/0x13d0 kernel/smp.c:892 Code: 89 ee 83 e6 01 31 ff e8 da 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 85 03 0c 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 6a 03 0c 00 eb e5 44 89 RSP: 0018:ffffc90005677700 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b873c148 RCX: ffff88807d541ec0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90005677840 R08: ffffffff9030b6f7 R09: 1ffffffff20616de R10: dffffc0000000000 R11: fffffbfff20616df R12: 1ffff110170c8589 R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812538d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34d1bff8 CR3: 000000000e74a000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline] smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2983 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906 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