rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=93a4/1/0x4000000000000000 softirq=17116/17118 fqs=1 rcu: (detected by 1, t=10506 jiffies, g=11281, q=164 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5925 Comm: kworker/0:5 Not tainted 6.13.0-syzkaller-06167-g0afd22092df4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: usb_hub_wq hub_event RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:299 Code: 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 RSP: 0018:ffffc90000007df8 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff8880b862c880 RCX: ffffffff81a6ff8e RDX: 0000000000000004 RSI: 0000000000000010 RDI: 0000000000000000 RBP: ffff888053e97340 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000005 R12: ffff8880b862c680 R13: 0000000000000010 R14: ffff8880b862c680 R15: ffffffff89690320 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6fa5771d58 CR3: 000000007b30c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: enqueue_hrtimer+0xfa/0x3c0 kernel/time/hrtimer.c:1076 __run_hrtimer kernel/time/hrtimer.c:1755 [inline] __hrtimer_run_queues+0x903/0xae0 kernel/time/hrtimer.c:1802 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1864 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 96 ca 3e f6 48 89 df e8 ee 49 3f f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 35 20 30 f6 65 8b 05 96 f2 ab 74 85 c0 74 16 5b RSP: 0018:ffffc90004b16f78 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff888028ec0000 RCX: 1ffffffff2ddd635 RDX: 0000000000000000 RSI: ffffffff8b6cd840 RDI: ffffffff8bd2e7c0 RBP: 0000000000000246 R08: 0000000000000001 R09: fffffbfff2dd6fa8 R10: ffffffff96eb7d47 R11: 0000000000000006 R12: 0000000000000002 R13: 0000000000000000 R14: ffff8880290db408 R15: ffff8880357e6008 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] dummy_urb_enqueue+0x546/0x8e0 drivers/usb/gadget/udc/dummy_hcd.c:1314 usb_hcd_submit_urb+0x2d1/0x2090 drivers/usb/core/hcd.c:1533 usb_submit_urb+0x87c/0x1730 drivers/usb/core/urb.c:581 usb_start_wait_urb+0x103/0x4c0 drivers/usb/core/message.c:59 usb_internal_control_msg drivers/usb/core/message.c:103 [inline] usb_control_msg+0x327/0x4b0 drivers/usb/core/message.c:154 usb_get_string+0xab/0x1a0 drivers/usb/core/message.c:844 usb_string_sub+0x107/0x390 drivers/usb/core/message.c:883 usb_string+0x307/0x670 drivers/usb/core/message.c:988 usb_cache_string+0x80/0x150 drivers/usb/core/message.c:1030 usb_set_configuration+0x1697/0x1c50 drivers/usb/core/message.c:2182 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534 device_add+0x114b/0x1a70 drivers/base/core.c:3665 usb_new_device+0xd09/0x1a20 drivers/usb/core/hub.c:2651 hub_port_connect drivers/usb/core/hub.c:5523 [inline] hub_port_connect_change drivers/usb/core/hub.c:5663 [inline] port_event drivers/usb/core/hub.c:5823 [inline] hub_event+0x2d9a/0x4e10 drivers/usb/core/hub.c:5905 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10500 jiffies! g11281 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28280 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x1142/0x5b60 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 35 Comm: kworker/u8:2 Not tainted 6.13.0-syzkaller-06167-g0afd22092df4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4cb/0x12c0 kernel/smp.c:885 Code: 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 fc 04 0c 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 e8 0b 00 00 8b 43 08 31 ff 83 e0 01 41 RSP: 0000:ffffc90000ab7928 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8646980 RCX: ffffffff81adc2da RDX: ffff888143ec2440 RSI: ffffffff81adc2b4 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170c8d31 R13: 0000000000000001 R14: ffff8880b873fe00 R15: ffff8880b8646988 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f57c1911d58 CR3: 000000000df80000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_flush arch/x86/kernel/alternative.c:2512 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:849 [inline] toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:841 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244