mceusb 1-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (8800 ticks this GP) idle=6de/1/0x4000000000000000 softirq=24017/24017 fqs=0 (t=10500 jiffies g=32757 q=691) rcu: rcu_preempt kthread starved for 10500 jiffies! g32757 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:29168 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x911/0x21b0 kernel/sched/core.c:5073 schedule+0xcf/0x270 kernel/sched/core.c:5152 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892 rcu_gp_fqs_loop kernel/rcu/tree.c:2005 [inline] rcu_gp_kthread+0xd07/0x2250 kernel/rcu/tree.c:2178 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted 5.12.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound call_usermodehelper_exec_work Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation+0x1c7/0x1e4 kernel/rcu/tree_stall.h:478 print_cpu_stall kernel/rcu/tree_stall.h:620 [inline] check_cpu_stall kernel/rcu/tree_stall.h:697 [inline] rcu_pending kernel/rcu/tree.c:3830 [inline] rcu_sched_clock_irq.cold+0x4f2/0x11dd kernel/rcu/tree.c:2650 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191 Code: 74 24 10 e8 fa 6d 54 f8 48 89 ef e8 22 24 55 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 13 f2 48 f8 65 8b 05 dc bc fc 76 85 c0 74 0a 5b 5d c3 e8 80 ad RSP: 0018:ffffc90000007b28 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1f5e5ea RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001 RBP: ffff88801c570000 R08: 0000000000000001 R09: ffffffff8fa98997 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8881440b9440 R13: ffff888013478f00 R14: dffffc0000000000 R15: ffff8880118c6e00 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline] dummy_timer+0x12f1/0x32a0 drivers/usb/gadget/udc/dummy_hcd.c:1985 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431 expire_timers kernel/time/timer.c:1476 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745 __run_timers kernel/time/timer.c:1726 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 do_softirq.part.0+0xd9/0x130 kernel/softirq.c:248 do_softirq kernel/softirq.c:240 [inline] __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:198 local_bh_enable include/linux/bottom_half.h:32 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:78 [inline] fpu__copy+0x182/0x660 arch/x86/kernel/fpu/core.c:246 dup_task_struct kernel/fork.c:873 [inline] copy_process+0x902/0x71a0 kernel/fork.c:1948 kernel_clone+0xe7/0xab0 kernel/fork.c:2500 kernel_thread+0xb5/0xf0 kernel/fork.c:2552 call_usermodehelper_exec_work kernel/umh.c:172 [inline] call_usermodehelper_exec_work+0xcc/0x180 kernel/umh.c:158 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 NMI backtrace for cpu 0 CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted 5.12.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound call_usermodehelper_exec_work Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x222/0x2a7 kernel/rcu/tree_stall.h:341 print_cpu_stall kernel/rcu/tree_stall.h:622 [inline] check_cpu_stall kernel/rcu/tree_stall.h:697 [inline] rcu_pending kernel/rcu/tree.c:3830 [inline] rcu_sched_clock_irq.cold+0x4f7/0x11dd kernel/rcu/tree.c:2650 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191 Code: 74 24 10 e8 fa 6d 54 f8 48 89 ef e8 22 24 55 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 13 f2 48 f8 65 8b 05 dc bc fc 76 85 c0 74 0a 5b 5d c3 e8 80 ad RSP: 0018:ffffc90000007b28 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1f5e5ea RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001 RBP: ffff88801c570000 R08: 0000000000000001 R09: ffffffff8fa98997 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8881440b9440 R13: ffff888013478f00 R14: dffffc0000000000 R15: ffff8880118c6e00 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline] dummy_timer+0x12f1/0x32a0 drivers/usb/gadget/udc/dummy_hcd.c:1985 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431 expire_timers kernel/time/timer.c:1476 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745 __run_timers kernel/time/timer.c:1726 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 do_softirq.part.0+0xd9/0x130 kernel/softirq.c:248 do_softirq kernel/softirq.c:240 [inline] __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:198 local_bh_enable include/linux/bottom_half.h:32 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:78 [inline] fpu__copy+0x182/0x660 arch/x86/kernel/fpu/core.c:246 dup_task_struct kernel/fork.c:873 [inline] copy_process+0x902/0x71a0 kernel/fork.c:1948 kernel_clone+0xe7/0xab0 kernel/fork.c:2500 kernel_thread+0xb5/0xf0 kernel/fork.c:2552 call_usermodehelper_exec_work kernel/umh.c:172 [inline] call_usermodehelper_exec_work+0xcc/0x180 kernel/umh.c:158 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 mceusb 5-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 1-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71 mceusb 5-1:0.0: Error: urb status = -71 mceusb 4-1:0.0: Error: urb status = -71