rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5967/1:b..l rcu: (detected by 1, t=20176 jiffies, g=13489, q=335 ncpus=2) task:syz-executor state:R running task stack:21272 pid:5967 tgid:5967 ppid:5958 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872 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 14 f5 da 10 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000425e9d0 EFLAGS: 00000206 RAX: 9a1c7ebedfaf4200 RBX: 0000000000000000 RCX: 9a1c7ebedfaf4200 RDX: 0000000003b19173 RSI: ffffffff8d96aaff RDI: ffffffff8bbffbe0 RBP: ffffffff8262df0c R08: ffffffff8262df0c R09: ffffffff8df41cc0 R10: dffffc0000000000 R11: ffffed102808a025 R12: 0000000000000002 R13: ffffffff8df41cc0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75 kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline] kernfs_parent+0x51/0x190 fs/kernfs/kernfs-internal.h:133 kernfs_add_one+0x49/0x530 fs/kernfs/dir.c:792 __kernfs_create_file+0x22b/0x2e0 fs/kernfs/file.c:1086 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x667/0x1110 fs/sysfs/group.c:183 internal_create_groups fs/sysfs/group.c:223 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:249 device_add_groups drivers/base/core.c:2836 [inline] device_add_attrs+0xe0/0x5a0 drivers/base/core.c:2900 device_add+0x496/0xb50 drivers/base/core.c:3643 wiphy_register+0x1d2e/0x2d20 net/wireless/core.c:1035 ieee80211_register_hw+0x3473/0x40d0 net/mac80211/main.c:1590 mac80211_hwsim_new_radio+0x2f8b/0x5240 drivers/net/wireless/virtual/mac80211_hwsim.c:5810 hwsim_new_radio_nl+0xf5b/0x1bd0 drivers/net/wireless/virtual/mac80211_hwsim.c:6504 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:733 __sys_sendto+0x3bd/0x520 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2200 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f15e5d915dc RSP: 002b:00007fff8fc354d0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f15e6b14620 RCX: 00007f15e5d915dc RDX: 0000000000000024 RSI: 00007f15e6b14670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fff8fc35524 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f15e6b14670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 20176 jiffies! g13489 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:27112 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3434 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__kasan_check_write+0xa/0x20 mm/kasan/shadow.c:37 Code: ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 89 f6 48 8b 0c 24 01 00 00 00 e9 bc e4 ff ff 66 66 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90000007b78 EFLAGS: 00000046 RAX: 1ffff11006477e41 RBX: ffff8880323bf000 RCX: ffffffff892cf03d RDX: 0000000000010000 RSI: 0000000000000008 RDI: ffff8880323bf198 RBP: ffffc90000007c60 R08: ffffffff89663f38 R09: ffffffff8df41cc0 R10: dffffc0000000000 R11: ffffed1006477e56 R12: ffff8880323bf320 R13: 1ffff92000000f74 R14: ffff8880323bf208 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88812608e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0000a00a8 CR3: 000000000dd3a000 CR4: 0000000000350ef0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline] __netif_schedule+0xbd/0x2e0 net/core/dev.c:3384 advance_sched+0xa9a/0xc90 net/sched/sch_taprio.c:992 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xccf/0x12b0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 6a 95 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 15 91 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 f9 90 RSP: 0018:ffffc9000c2f7620 EFLAGS: 00000293 RAX: ffffffff81b5ba87 RBX: 1ffff11017128101 RCX: ffff888030029e80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000c2f77a0 R08: ffffffff8f812d77 R09: 1ffffffff1f025ae R10: dffffc0000000000 R11: fffffbfff1f025af R12: ffff8880b8940808 R13: dffffc0000000000 R14: ffff8880b883b9c0 R15: 0000000000000001 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2921 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+0xad/0x240 mm/kfence/core.c:854 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246