rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (2 ticks this GP) idle=e284/1/0x4000000000000000 softirq=180172/180172 fqs=3 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P30482/1:b..l P5275/1:b..l rcu: (detected by 0, t=10502 jiffies, g=220189, q=789 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5280 Comm: syz.1.8340 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:mark_usage kernel/locking/lockdep.c:-1 [inline] RIP: 0010:__lock_acquire+0x6a0/0x2cf0 kernel/locking/lockdep.c:5191 Code: 1a 48 8b 7c 24 08 4c 89 ee ba 04 00 00 00 e8 87 44 00 00 85 c0 0f 84 99 0d 00 00 41 8b 45 20 a9 00 00 18 00 0f 84 bc 00 00 00 <4c> 8b 74 24 08 4c 89 f7 4c 89 ee ba 08 00 00 00 e8 5b 44 00 00 31 RSP: 0018:ffffc90000a08b80 EFLAGS: 00000006 RAX: 00000000000c4000 RBX: ffff88804f666868 RCX: ffffffff93e6a4b0 RDX: 0000000000000000 RSI: ffff88804f666848 RDI: ffff88804f665c40 RBP: 0000000000000000 R08: ffffffff84b9bfec R09: ffffffff9a757060 R10: ffff888045bac308 R11: ffffed1008b75863 R12: 0000000000000002 R13: ffff88804f666848 R14: ffff88804f665c40 R15: 0000000000000003 FS: 00007f893c8dc6c0(0000) GS:ffff888125343000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000012c0 CR3: 00000000aaa32000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 debug_object_deactivate+0x6c/0x3a0 lib/debugobjects.c:890 debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline] __run_hrtimer kernel/time/hrtimer.c:1898 [inline] __hrtimer_run_queues+0x23a/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 0d 1c ec f5 f7 c3 00 02 00 00 74 05 e8 10 38 17 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 a4 ad dd f5 65 8b 05 9d d0 87 07 85 c0 74 18 5b 41 5e e9 41 48 RSP: 0018:ffffc90004136ee8 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000282 RCX: 0000000080000202 RDX: 0000000000000002 RSI: ffffffff8dfb6c9c RDI: 0000000000000001 RBP: ffffc900041371d0 R08: ffffffff903219b7 R09: 1ffffffff2064336 R10: dffffc0000000000 R11: fffffbfff2064337 R12: ffff888045bac290 R13: dffffc0000000000 R14: ffff888045bac2a8 R15: ffff888045bac2f8 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] taprio_change+0x30fe/0x3e50 net/sched/sch_taprio.c:1986 taprio_init+0x96f/0xbe0 net/sched/sch_taprio.c:2125 qdisc_create+0x7c4/0xf20 net/sched/sch_api.c:1319 __tc_modify_qdisc net/sched/sch_api.c:1753 [inline] tc_modify_qdisc+0x16f0/0x2290 net/sched/sch_api.c:1817 rtnetlink_rcv_msg+0x77e/0xbe0 net/core/rtnetlink.c:7004 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_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 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: 0033:0x7f893b99c819 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:00007f893c8dc028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f893bc15fa0 RCX: 00007f893b99c819 RDX: 0000000000000010 RSI: 00002000000012c0 RDI: 0000000000000006 RBP: 00007f893ba32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f893bc16038 R14: 00007f893bc15fa0 R15: 00007fff9fe2eb68 task:syz.3.8341 state:R running task stack:25112 pid:5275 tgid:5275 ppid:28614 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7364 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1959 [inline] zap_pmd_range mm/memory.c:2021 [inline] zap_pud_range mm/memory.c:2049 [inline] zap_p4d_range mm/memory.c:2070 [inline] unmap_page_range+0x3b71/0x48f0 mm/memory.c:2091 unmap_single_vma mm/memory.c:2133 [inline] unmap_vmas+0x48f/0x6a0 mm/memory.c:2171 exit_mmap+0x280/0x9e0 mm/mmap.c:1302 __mmput+0x118/0x430 kernel/fork.c:1177 exit_mm+0x18e/0x250 kernel/exit.c:581 do_exit+0x6a2/0x23c0 kernel/exit.c:965 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119 __do_sys_exit_group kernel/exit.c:1130 [inline] __se_sys_exit_group kernel/exit.c:1128 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1128 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f483dd9c819 RSP: 002b:00007ffebe5d9b58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f483dd9c819 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffebe5d9bbc R08: 0000000000000000 R09: 00000000000927c0 R10: 00007f483e016038 R11: 0000000000000246 R12: 00000000000001f2 R13: 00000000000927c0 R14: 00000000000f72e0 R15: 00007ffebe5d9c10 task:syz-executor state:R running task stack:22264 pid:30482 tgid:30482 ppid:30468 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7507 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x7f/0x3c0 kernel/locking/lockdep.c:5881 Code: d6 a5 90 0e 00 0f 84 1c 02 00 00 65 8b 05 e9 6e 9c 11 85 c0 0f 85 0d 02 00 00 65 4c 8b 3d 31 29 9c 11 41 83 bf 8c 0b 00 00 00 <0f> 85 f7 01 00 00 49 81 3e c0 a4 01 94 0f 84 ea 01 00 00 9c 5b fa RSP: 0018:ffffc9000581eed0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff914cbc01 RCX: 0000000080000001 RDX: ffffc9000581f001 RSI: ffffffff8c27efe0 RDI: ffffffff8c27efa0 RBP: dffffc0000000000 R08: ffffc9000581fee0 R09: 0000000000000000 R10: ffffc9000581f058 R11: fffff52000b03e0d R12: ffffc9000581fef0 R13: ffffffff81766536 R14: ffffffff8e95d020 R15: ffff88806a725c40 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0x1bba/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978 ___free_pages_bulk mm/kasan/shadow.c:333 [inline] __kasan_populate_vmalloc_do mm/kasan/shadow.c:385 [inline] __kasan_populate_vmalloc+0x137/0x1d0 mm/kasan/shadow.c:424 kasan_populate_vmalloc include/linux/kasan.h:580 [inline] alloc_vmap_area+0xd47/0x1480 mm/vmalloc.c:2129 __get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3232 __vmalloc_node_range_noprof+0x372/0x1730 mm/vmalloc.c:4024 __vmalloc_node_noprof mm/vmalloc.c:4124 [inline] vzalloc_noprof+0xb2/0xe0 mm/vmalloc.c:4202 alloc_counters+0x64/0x5d0 net/ipv4/netfilter/ip_tables.c:799 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:821 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1022 [inline] do_ipt_get_ctl+0xada/0x1240 net/ipv4/netfilter/ip_tables.c:1668 nf_getsockopt+0x26e/0x290 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x19e/0x230 net/ipv4/ip_sockglue.c:1777 do_sock_getsockopt+0x51d/0x7e0 net/socket.c:2487 __sys_getsockopt net/socket.c:2518 [inline] __do_sys_getsockopt net/socket.c:2525 [inline] __se_sys_getsockopt net/socket.c:2522 [inline] __x64_sys_getsockopt+0x1a4/0x240 net/socket.c:2522 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: 0033:0x7fdb2f79dfea RSP: 002b:00007ffdff132ba8 EFLAGS: 00000216 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007ffdff132c30 RCX: 00007fdb2f79dfea RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007ffdff132bcc R09: 0000000000000000 R10: 00007ffdff132c30 R11: 0000000000000216 R12: 00007fdb2f9ebac0 R13: 00007ffdff132bcc R14: 0000000000000000 R15: 00007fdb2f9ec180 rcu: rcu_preempt kthread starved for 10496 jiffies! g220189 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] schedule+0x164/0x360 kernel/sched/core.c:7277 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: 0 UID: 0 PID: 30893 Comm: kworker/u8:2 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+0xe32/0x1210 kernel/smp.c:892 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 77 e7 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 22 e3 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 06 e3 RSP: 0018:ffffc900043b7700 EFLAGS: 00000293 RAX: ffffffff81b97aea RBX: 1ffff110170e8165 RCX: ffff8880325bdc40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900043b7840 R08: ffffffff903219b7 R09: 1ffffffff2064336 R10: dffffc0000000000 R11: fffffbfff2064337 R12: ffff8880b8740b28 R13: dffffc0000000000 R14: ffff8880b863c148 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125243000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fadc701c368 CR3: 000000000e74a000 CR4: 00000000003526f0 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:2761 [inline] smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2971 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:900 process_one_work kernel/workqueue.c:3288 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3371 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3452 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