usbtmc 5-1:0.0: unknown status received: -71 usbtmc 6-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 6-1:0.0: unknown status received: -71 rcu: INFO: rcu_sched detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=443761, q=96) rcu: All QSes seen, last rcu_sched kthread activity 10489 (4295207084-4295196595), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_sched kthread starved for 10489 jiffies! g443761 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_sched kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_sched state:R running task stack:29088 pid: 11 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4322 [inline] __schedule+0x920/0x1fa0 kernel/sched/core.c:5073 schedule+0xcb/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+0xa36/0x1ba0 kernel/rcu/tree.c:2178 kthread+0x38c/0x460 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: 6218 Comm: kworker/u4:3 Not tainted 5.12.0-rc7-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+0x143/0x1db lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x46/0xe0 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1da/0x200 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_other_cpu_stall kernel/rcu/tree_stall.h:582 [inline] check_cpu_stall kernel/rcu/tree_stall.h:706 [inline] rcu_pending kernel/rcu/tree.c:3830 [inline] rcu_sched_clock_irq.cold+0xa0c/0xada kernel/rcu/tree.c:2650 update_process_times+0x139/0x1b0 kernel/time/timer.c:1796 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1a4/0x2c0 kernel/time/tick-sched.c:1369 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xd80 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x2fc/0x9b0 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0xf5/0x420 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x2f/0x90 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+0x3a/0x50 kernel/locking/spinlock.c:192 Code: 10 e8 ca 7c 75 fb 48 89 ef e8 a2 30 76 fb 81 e3 00 02 00 00 75 17 9c 58 f6 c4 02 75 17 48 85 db 74 01 fb 65 ff 0d 36 18 50 7a <5b> 5d c3 e8 be 62 94 fb eb e2 e8 b7 85 fe ff eb e2 0f 1f 44 00 00 RSP: 0018:ffffc90000007b28 EFLAGS: 00000202 RAX: 0000000000000016 RBX: 0000000000000200 RCX: 1ffffffff1446e6a RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff85b1d6d2 RBP: ffff8881090d8000 R08: 0000000000000001 R09: ffffffff8a1fe7b7 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888103073440 R13: ffff88811232ad00 R14: dffffc0000000000 R15: ffff88810d0b1000 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline] dummy_timer+0x12f1/0x32a0 drivers/usb/gadget/udc/dummy_hcd.c:1985 call_timer_fn+0x1a5/0x630 kernel/time/timer.c:1431 expire_timers kernel/time/timer.c:1476 [inline] __run_timers.part.0+0x67c/0xa10 kernel/time/timer.c:1745 __run_timers kernel/time/timer.c:1726 [inline] run_timer_softirq+0x80/0x120 kernel/time/timer.c:1758 __do_softirq+0x1b0/0x944 kernel/softirq.c:345 do_softirq.part.0+0x92/0xd0 kernel/softirq.c:248 do_softirq arch/x86/include/asm/preempt.h:27 [inline] __local_bh_enable_ip+0xd3/0xf0 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+0x182/0x5e0 arch/x86/kernel/fpu/core.c:246 dup_task_struct kernel/fork.c:873 [inline] copy_process+0x902/0x6d10 kernel/fork.c:1948 kernel_clone+0xe7/0xa70 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/0x1580 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71 usbtmc 5-1:0.0: unknown status received: -71