rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (3 ticks this GP) idle=307/1/0x4000000000000000 softirq=16468/16468 fqs=6 (detected by 0, t=10504 jiffies, g=24309, q=636) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3662 Comm: kworker/1:8 Not tainted 5.15.164-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: usb_hub_wq hub_event RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xe0/0x130 kernel/locking/spinlock.c:194 Code: 4c 89 f7 e8 f2 90 8d f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 e8 97 c6 1a f7 65 8b 05 58 cb c5 75 <85> c0 74 3f 48 c7 04 24 0e 36 e0 45 4b c7 04 2c 00 00 00 00 65 48 RSP: 0000:ffffc90000dd0c20 EFLAGS: 00000013 RAX: 0000000000010002 RBX: 1ffff920001ba188 RCX: 0000000000010003 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffffc90000dd0cb8 R08: dffffc0000000000 R09: fffffbfff22c750d R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff920001ba184 R14: ffffc90000dd0c40 R15: 0000000000000046 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa45d81c020 CR3: 0000000016ba9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_object_activate+0x2f4/0x4e0 lib/debugobjects.c:711 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x30/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1703 [inline] __hrtimer_run_queues+0x6b6/0xcf0 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:check_preemption_disabled+0x19/0x110 lib/smp_processor_id.c:14 Code: cc 48 c7 c7 a0 f7 d8 8a 48 c7 c6 e0 f7 d8 8a eb 00 41 57 41 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 1d 08 f4 ce 75 65 8b 05 71 4e cf 75 a9 ff ff ff 7f 74 22 65 RSP: 0000:ffffc9000317e6f8 EFLAGS: 00000282 RAX: bf42f8f83afb0e00 RBX: ffff888063569bc8 RCX: 00000000000000a8 RDX: 00000000000000a8 RSI: ffffffff8ad8f7e0 RDI: ffffffff8ad8f7a0 RBP: ffff888063569bc8 R08: 00000000000000e8 R09: ffff888063569bc8 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888011df2b40 R13: ffff888011df2b40 R14: ffffffff81fc706b R15: 0000000000000dc0 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline] rcu_is_watching+0x11/0xa0 kernel/rcu/tree.c:1123 trace_kmem_cache_alloc include/trace/events/kmem.h:54 [inline] kmem_cache_alloc+0x128/0x280 mm/slub.c:3235 kmem_cache_zalloc include/linux/slab.h:711 [inline] __kernfs_new_node+0xdb/0x750 fs/kernfs/dir.c:593 kernfs_new_node+0x136/0x230 fs/kernfs/dir.c:669 __kernfs_create_file+0x45/0x2e0 fs/kernfs/file.c:985 sysfs_add_file_mode_ns+0x308/0x3e0 fs/sysfs/file.c:317 sysfs_merge_group+0x1fe/0x450 fs/sysfs/group.c:343 dpm_sysfs_add+0xcf/0x270 drivers/base/power/sysfs.c:707 device_add+0x702/0xfd0 drivers/base/core.c:3369 snd_card_register+0x118/0x6a0 sound/core/init.c:882 try_to_register_card+0x2f5/0x3c0 sound/usb/card.c:753 usb_audio_probe+0x1a7c/0x2090 sound/usb/card.c:918 usb_probe_interface+0x5c0/0xaf0 drivers/usb/core/driver.c:396 really_probe+0x24e/0xb60 drivers/base/dd.c:595 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:755 driver_probe_device+0x50/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b9/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:427 __device_attach+0x359/0x570 drivers/base/dd.c:979 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:487 device_add+0xb48/0xfd0 drivers/base/core.c:3412 usb_set_configuration+0x19dd/0x2020 drivers/usb/core/message.c:2165 usb_generic_driver_probe+0x84/0x140 drivers/usb/core/generic.c:238 usb_probe_device+0x130/0x260 drivers/usb/core/driver.c:293 really_probe+0x24e/0xb60 drivers/base/dd.c:595 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:755 driver_probe_device+0x50/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b9/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:427 __device_attach+0x359/0x570 drivers/base/dd.c:979 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:487 device_add+0xb48/0xfd0 drivers/base/core.c:3412 usb_new_device+0xc17/0x18e0 drivers/usb/core/hub.c:2593 hub_port_connect drivers/usb/core/hub.c:5455 [inline] hub_port_connect_change drivers/usb/core/hub.c:5595 [inline] port_event drivers/usb/core/hub.c:5741 [inline] hub_event+0x2cdf/0x54c0 drivers/usb/core/hub.c:5823 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 timer wakeup didn't happen for 7083 jiffies! g24309 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=9312 rcu: rcu_preempt kthread starved for 7084 jiffies! g24309 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26168 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 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: 3965 Comm: kworker/0:11 Not tainted 5.15.164-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: events fqdir_free_fn 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:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_single+0x297/0x530 kernel/smp.c:758 Code: 00 44 8b 6c 24 48 44 89 ee 83 e6 01 31 ff e8 c0 e4 0b 00 41 83 e5 01 75 0a e8 55 e1 0b 00 e9 eb 00 00 00 f3 90 42 0f b6 04 23 <84> c0 75 15 f7 44 24 48 01 00 00 00 0f 84 cd 00 00 00 e8 32 e1 0b RSP: 0018:ffffc90003687a60 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff920006d0f55 RCX: ffff888023fa5940 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003687b50 R08: ffffffff81748000 R09: ffffed1017367681 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 0000000000000001 R14: ffffc90003687aa8 R15: 0000000000000000 rcu_barrier+0x262/0x4e0 kernel/rcu/tree.c:4078 fqdir_free_fn+0x2e/0x130 net/ipv4/inet_fragment.c:163 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