rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12948/1:b..l rcu: (detected by 1, t=10502 jiffies, g=78349, q=703 ncpus=2) task:syz-executor state:R running task stack:20928 pid:12948 tgid:12948 ppid:1 task_flags:0x48054c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:127 sock_def_readable+0x1eb/0x530 net/core/sock.c:3611 __netlink_sendskb net/netlink/af_netlink.c:1263 [inline] netlink_broadcast_deliver net/netlink/af_netlink.c:1399 [inline] do_one_broadcast net/netlink/af_netlink.c:1488 [inline] netlink_broadcast_filtered+0xc2e/0x1000 net/netlink/af_netlink.c:1533 netlink_broadcast+0x37/0x50 net/netlink/af_netlink.c:1557 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline] kobject_uevent_net_broadcast+0x378/0x560 lib/kobject_uevent.c:410 kobject_uevent_env+0x55c/0x9f0 lib/kobject_uevent.c:608 device_del+0x73a/0x8e0 drivers/base/core.c:3896 rfkill_unregister+0xba/0x220 net/rfkill/core.c:1143 hci_unregister_dev+0x374/0x5b0 net/bluetooth/hci_core.c:2732 vhci_release+0x152/0x1a0 drivers/bluetooth/hci_vhci.c:690 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6c5/0x2310 kernel/exit.c:971 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f26eb7915dc RSP: 002b:00007fffad517bb0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: 0000000000000040 RBX: 00007f26ec514620 RCX: 00007f26eb7915dc RDX: 0000000000000040 RSI: 00007f26ec514670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fffad517c04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f26ec514670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10540 jiffies! g78349 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:26880 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: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:profile_pc+0x4/0x40 arch/x86/kernel/time.c:29 Code: 00 00 48 c7 c7 e0 b5 d6 8d 4c 89 f2 e8 a5 16 61 03 31 c0 eb d8 cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <53> 48 89 fb e8 53 b2 5a 00 48 83 eb 80 48 89 d8 48 c1 e8 03 48 b9 RSP: 0018:ffffc90000007c30 EFLAGS: 00000046 RAX: ffffffff81ad99a5 RBX: 0000000000000001 RCX: 0000000000010000 RDX: ffffffff8dc95340 RSI: 0000000000000000 RDI: ffffffff8dc07cd8 RBP: 0000000000000000 R08: ffffffff92853e4b R09: 1ffffffff250a7c9 R10: dffffc0000000000 R11: fffffbfff250a7ca R12: ffff8880b8628ba0 R13: dffffc0000000000 R14: ffffffff8dc07cd8 R15: ffffffff8dc07d60 FS: 0000000000000000(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f74b1facf98 CR3: 0000000099d3d000 CR4: 0000000000350ef0 Call Trace: profile_tick+0x69/0xc0 kernel/profile.c:139 tick_sched_handle kernel/time/tick-sched.c:299 [inline] tick_nohz_handler+0x3f3/0x710 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x4d0/0xc30 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:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 5e 83 b4 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 93 90 0c 00 f3 0f 1e fa fb f4 33 83 b4 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6 RAX: 3a1e245f9cde7400 RBX: ffffffff81978fda RCX: 3a1e245f9cde7400 RDX: 0000000000000001 RSI: ffffffff8d7925c0 RDI: ffffffff8bc08360 RBP: ffffffff8dc07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f822070 R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3a7/0x400 init/main.c:1206 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147