rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3663/1:b..l P7213/1:b..l (detected by 0, t=10502 jiffies, g=38389, q=540) task:syz-executor state:R running task stack:21152 pid: 7213 ppid: 7211 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6549 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6574 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x128/0x130 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] __wake_up_common_lock kernel/sched/wait.c:140 [inline] __wake_up_sync_key+0x121/0x1c0 kernel/sched/wait.c:205 sock_def_readable+0x135/0x240 net/core/sock.c:3092 __netlink_sendskb net/netlink/af_netlink.c:1273 [inline] netlink_broadcast_deliver net/netlink/af_netlink.c:1405 [inline] do_one_broadcast net/netlink/af_netlink.c:1490 [inline] netlink_broadcast_filtered+0xc60/0x11a0 net/netlink/af_netlink.c:1534 netlink_broadcast+0x35/0x50 net/netlink/af_netlink.c:1558 uevent_net_broadcast_tagged lib/kobject_uevent.c:372 [inline] kobject_uevent_net_broadcast+0x4c0/0x560 lib/kobject_uevent.c:412 kobject_uevent_env+0x567/0x8d0 lib/kobject_uevent.c:608 device_del+0x9c4/0xbd0 drivers/base/core.c:3613 unregister_netdevice_many+0x13a6/0x18f0 net/core/dev.c:11121 unregister_netdevice_queue+0x2e6/0x350 net/core/dev.c:11027 unregister_netdevice include/linux/netdevice.h:3012 [inline] nsim_destroy+0x44/0x140 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x153/0x1b0 drivers/net/netdevsim/dev.c:1349 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1362 [inline] nsim_dev_reload_destroy+0x15e/0x240 drivers/net/netdevsim/dev.c:1561 nsim_dev_remove+0x59/0x100 drivers/net/netdevsim/dev.c:1577 __device_release_driver drivers/base/dd.c:1227 [inline] device_release_driver_internal+0x4cb/0x7f0 drivers/base/dd.c:1262 bus_remove_device+0x2e5/0x400 drivers/base/bus.c:529 device_del+0x6e2/0xbd0 drivers/base/core.c:3603 device_unregister+0x1c/0xc0 drivers/base/core.c:3636 nsim_bus_dev_del drivers/net/netdevsim/bus.c:454 [inline] del_device_store+0x321/0x470 drivers/net/netdevsim/bus.c:354 kernfs_fop_write_iter+0x3a2/0x4f0 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xacd/0xe50 fs/read_write.c:594 ksys_write+0x1a2/0x2c0 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fbbbb81195f RSP: 002b:00007ffe7b71e590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fbbbb81195f RDX: 0000000000000001 RSI: 00007ffe7b71e5e0 RDI: 0000000000000005 RBP: 00007fbbbb8819dd R08: 0000000000000000 R09: 00007ffe7b71e3e7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007ffe7b71e5e0 R14: 00007fbbbc4dd620 R15: 0000000000000003 task:kworker/u4:7 state:R running task stack:18336 pid: 3663 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627 Code: 2b 00 74 08 4c 89 f7 e8 4c 7b 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc900030b7a20 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000616f50 RCX: 1ffff92000616ef0 RDX: dffffc0000000000 RSI: ffffffff8a8b3cc0 RDI: ffffffff8ad8f7c0 RBP: ffffc900030b7b70 R08: dffffc0000000000 R09: fffffbfff1f8e219 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000616f4c R13: dffffc0000000000 R14: ffffc900030b7a80 R15: 0000000000000246 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] batadv_nc_process_nc_paths+0xb8/0x350 net/batman-adv/network-coding.c:691 batadv_nc_worker+0x3d4/0x5b0 net/batman-adv/network-coding.c:732 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 9318 jiffies! g38389 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:27064 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.165-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562 Code: 8a 43 f7 48 83 e3 08 0f 85 0a 01 00 00 4c 8d 74 24 20 e8 24 07 4a f7 0f 1f 44 00 00 e8 8a 86 43 f7 0f 00 2d c3 50 a6 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 bb 4f 8d f7 RSP: 0018:ffffffff8c607b80 EFLAGS: 000002d3 RAX: ffffffff8a3cdb16 RBX: 0000000000000000 RCX: ffffffff8c6bd5c0 RDX: 0000000000000000 RSI: ffffffff8a8b2a20 RDI: ffffffff8ad8f7c0 RBP: ffffffff8c607c10 R08: ffffffff8186e260 R09: fffffbfff18d7ab9 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff18c0f70 R13: ffff88801853f804 R14: ffffffff8c607ba0 R15: dffffc0000000000 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:697 cpuidle_enter_state+0x521/0xef0 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3e4/0x670 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb