syzbot


INFO: rcu detected stall in dummy_timer (4)

Status: upstream: reported C repro on 2022/07/09 03:52
Reported-by: syzbot+879882be5b42e60d4d98@syzkaller.appspotmail.com
First crash: 146d, last: 24d

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: possible deadlock in display_open (log)
Repro: C syz .config
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in dummy_timer (2) 1 1113d 1113d 0/24 auto-closed as invalid on 2020/02/09 05:37
upstream INFO: rcu detected stall in dummy_timer (3) C error 132 279d 867d 22/24 fixed on 2022/03/08 16:11
upstream INFO: rcu detected stall in dummy_timer C 16 1142d 1207d 14/24 fixed on 2019/10/27 22:28
Patch testing requests:
Created Duration User Patch Repo Result
2022/07/09 07:43 18m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c1084b6c5620 OK log

Sample crash report:
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (6833 ticks this GP) idle=b884/1/0x4000000000000000 softirq=5879/5879 fqs=0
	(t=10500 jiffies g=4589 q=224 ncpus=2)
rcu: rcu_preempt kthread starved for 10500 jiffies! g4589 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:28856 pid:   16 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5178 [inline]
 __schedule+0xa00/0x4c10 kernel/sched/core.c:6490
 schedule+0xda/0x1b0 kernel/sched/core.c:6566
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935
 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1657
 rcu_gp_kthread+0x234/0x360 kernel/rcu/tree.c:1854
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 3606 Comm: strace-static-x Not tainted 5.19.0-syzkaller-02972-g200e340f2196 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:514
 print_cpu_stall kernel/rcu/tree_stall.h:658 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:744 [inline]
 rcu_pending kernel/rcu/tree.c:3660 [inline]
 rcu_sched_clock_irq.cold+0x3ff/0x77e kernel/rcu/tree.c:2342
 update_process_times+0x11a/0x1a0 kernel/time/timer.c:1839
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243
 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1480
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194
Code: 74 24 10 e8 7a ed e2 f7 48 89 ef e8 12 6f e3 f7 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 <e8> f3 70 d6 f7 65 8b 05 5c 98 87 76 85 c0 74 0a 5b 5d c3 e8 d0 83
RSP: 0018:ffffc900003f8b08 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff20db4f6
RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001
RBP: ffff8880210a8000 R08: 0000000000000001 R09: ffffffff9068ca0f
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888021b39440
R13: ffff8880170a0100 R14: dffffc0000000000 R15: ffff88807a36b300
 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline]
 dummy_timer+0x12f6/0x32b0 drivers/usb/gadget/udc/dummy_hcd.c:2002
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:finish_task_switch.isra.0+0x2bf/0xc70 kernel/sched/core.c:5058
Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 60 f8 ff ff e8 7b 98 2e 00 fb 65 48 8b 1c 25 80 6f 02 00 <48> 8d bb 98 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc9000310fb38 EFLAGS: 00000206
RAX: 000000000007abc3 RBX: ffff88802499e180 RCX: 1ffffffff1b76681
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000310fb80 R08: 0000000000000001 R09: 0000000000000001
R10: ffffed1017367400 R11: 0000000000000001 R12: ffff8880b9b3a000
R13: ffff888022e641c0 R14: 0000000000000000 R15: ffff8880b9b3aa38
 context_switch kernel/sched/core.c:5181 [inline]
 __schedule+0xa08/0x4c10 kernel/sched/core.c:6490
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6659
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202
 spin_unlock_irq include/linux/spinlock.h:399 [inline]
 ptrace_resume kernel/ptrace.c:885 [inline]
 ptrace_request+0x2db/0x10c0 kernel/ptrace.c:1218
 arch_ptrace+0x36/0x510 arch/x86/kernel/ptrace.c:828
 __do_sys_ptrace kernel/ptrace.c:1296 [inline]
 __se_sys_ptrace kernel/ptrace.c:1269 [inline]
 __x64_sys_ptrace+0x178/0x2a0 kernel/ptrace.c:1269
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x4e6c1a

================================
WARNING: inconsistent lock state
5.19.0-syzkaller-02972-g200e340f2196 #0 Not tainted
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
strace-static-x/3606 [HC1[1]:SC1[1]:HE0:SE0] takes:
ffffffff8beb59b8 (vmap_area_lock){?.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
ffffffff8beb59b8 (vmap_area_lock){?.+.}-{2:2}, at: find_vmap_area+0x1c/0x130 mm/vmalloc.c:1805
{HARDIRQ-ON-W} state was registered at:
  lock_acquire kernel/locking/lockdep.c:5666 [inline]
  lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631
  __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
  _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:349 [inline]
  alloc_vmap_area+0xa49/0x1f00 mm/vmalloc.c:1586
  __get_vm_area_node+0x142/0x3f0 mm/vmalloc.c:2453
  __vmalloc_node_range+0x250/0x13e0 mm/vmalloc.c:3125
  __vmalloc_node mm/vmalloc.c:3230 [inline]
  __vmalloc+0x69/0x80 mm/vmalloc.c:3244
  pcpu_mem_zalloc mm/percpu.c:516 [inline]
  pcpu_mem_zalloc+0x51/0xa0 mm/percpu.c:508
  pcpu_alloc_chunk mm/percpu.c:1454 [inline]
  pcpu_create_chunk+0xd7/0x930 mm/percpu-vm.c:338
  pcpu_alloc+0x1012/0x13d0 mm/percpu.c:1834
  alloc_kmem_cache_cpus.constprop.0+0x29/0xc0 mm/slab.c:1729
  do_tune_cpucache+0x37/0x230 mm/slab.c:3844
  enable_cpucache+0x3c/0xa0 mm/slab.c:3938
  kmem_cache_init_late+0x33/0x66 mm/slab.c:1276
  start_kernel+0x2f5/0x48f init/main.c:1059
  secondary_startup_64_no_verify+0xce/0xdb
irq event stamp: 544503
hardirqs last  enabled at (544502): [<ffffffff897ad6f0>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (544502): [<ffffffff897ad6f0>] _raw_spin_unlock_irqrestore+0x50/0x70 kernel/locking/spinlock.c:194
hardirqs last disabled at (544503): [<ffffffff8977a5bb>] sysvec_apic_timer_interrupt+0xb/0xc0 arch/x86/kernel/apic/apic.c:1106
softirqs last  enabled at (501032): [<ffffffff8147b4e3>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last  enabled at (501032): [<ffffffff8147b4e3>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
softirqs last disabled at (502725): [<ffffffff8147b4e3>] invoke_softirq kernel/softirq.c:445 [inline]
softirqs last disabled at (502725): [<ffffffff8147b4e3>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(vmap_area_lock);
  <Interrupt>
    lock(vmap_area_lock);

 *** DEADLOCK ***

1 lock held by strace-static-x/3606:
 #0: ffffc900003f8d70 ((&dum_hcd->timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline]
 #0: ffffc900003f8d70 ((&dum_hcd->timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1464

stack backtrace:
CPU: 1 PID: 3606 Comm: strace-static-x Not tainted 5.19.0-syzkaller-02972-g200e340f2196 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_usage_bug kernel/locking/lockdep.c:3961 [inline]
 valid_state kernel/locking/lockdep.c:3973 [inline]
 mark_lock_irq kernel/locking/lockdep.c:4176 [inline]
 mark_lock.part.0.cold+0x18/0xd8 kernel/locking/lockdep.c:4632
 mark_lock kernel/locking/lockdep.c:4596 [inline]
 mark_usage kernel/locking/lockdep.c:4524 [inline]
 __lock_acquire+0x14ad/0x5660 kernel/locking/lockdep.c:5007
 lock_acquire kernel/locking/lockdep.c:5666 [inline]
 lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:349 [inline]
 find_vmap_area+0x1c/0x130 mm/vmalloc.c:1805
 check_heap_object mm/usercopy.c:176 [inline]
 __check_object_size mm/usercopy.c:250 [inline]
 __check_object_size+0x1f8/0x700 mm/usercopy.c:212
 check_object_size include/linux/thread_info.h:199 [inline]
 __copy_from_user_inatomic include/linux/uaccess.h:62 [inline]
 copy_from_user_nmi arch/x86/lib/usercopy.c:47 [inline]
 copy_from_user_nmi+0xcb/0x130 arch/x86/lib/usercopy.c:31
 copy_code arch/x86/kernel/dumpstack.c:91 [inline]
 show_opcodes+0x59/0xb0 arch/x86/kernel/dumpstack.c:121
 show_iret_regs+0xd/0x33 arch/x86/kernel/dumpstack.c:149
 __show_regs+0x1e/0x60 arch/x86/kernel/process_64.c:74
 show_trace_log_lvl+0x25b/0x2ba arch/x86/kernel/dumpstack.c:292
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:514
 print_cpu_stall kernel/rcu/tree_stall.h:658 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:744 [inline]
 rcu_pending kernel/rcu/tree.c:3660 [inline]
 rcu_sched_clock_irq.cold+0x3ff/0x77e kernel/rcu/tree.c:2342
 update_process_times+0x11a/0x1a0 kernel/time/timer.c:1839
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243
 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1480
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194
Code: 74 24 10 e8 7a ed e2 f7 48 89 ef e8 12 6f e3 f7 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 <e8> f3 70 d6 f7 65 8b 05 5c 98 87 76 85 c0 74 0a 5b 5d c3 e8 d0 83
RSP: 0018:ffffc900003f8b08 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff20db4f6
RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001
RBP: ffff8880210a8000 R08: 0000000000000001 R09: ffffffff9068ca0f
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888021b39440
R13: ffff8880170a0100 R14: dffffc0000000000 R15: ffff88807a36b300
 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline]
 dummy_timer+0x12f6/0x32b0 drivers/usb/gadget/udc/dummy_hcd.c:2002
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:finish_task_switch.isra.0+0x2bf/0xc70 kernel/sched/core.c:5058
Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 60 f8 ff ff e8 7b 98 2e 00 fb 65 48 8b 1c 25 80 6f 02 00 <48> 8d bb 98 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc9000310fb38 EFLAGS: 00000206
RAX: 000000000007abc3 RBX: ffff88802499e180 RCX: 1ffffffff1b76681
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000310fb80 R08: 0000000000000001 R09: 0000000000000001
R10: ffffed1017367400 R11: 0000000000000001 R12: ffff8880b9b3a000
R13: ffff888022e641c0 R14: 0000000000000000 R15: ffff8880b9b3aa38
 context_switch kernel/sched/core.c:5181 [inline]
 __schedule+0xa08/0x4c10 kernel/sched/core.c:6490
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6659
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202
 spin_unlock_irq include/linux/spinlock.h:399 [inline]
 ptrace_resume kernel/ptrace.c:885 [inline]
 ptrace_request+0x2db/0x10c0 kernel/ptrace.c:1218
 arch_ptrace+0x36/0x510 arch/x86/kernel/ptrace.c:828
 __do_sys_ptrace kernel/ptrace.c:1296 [inline]
 __se_sys_ptrace kernel/ptrace.c:1269 [inline]
 __x64_sys_ptrace+0x178/0x2a0 kernel/ptrace.c:1269
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x4e6c1a
Code: 70 41 83 f8 03 c7 44 24 10 08 00 00 00 48 89 44 24 18 48 8d 44 24 30 8b 70 08 4c 0f 43 d1 48 89 44 24 20 b8 65 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3e 48 85 c0 78 06 41 83 f8 02 76 1b 48 8b 4c
RSP: 002b:00007ffeeade96b0 EFLAGS: 00000206 ORIG_RAX: 0000000000000065
RAX: ffffffffffffffda RBX: 00000000021df2f8 RCX: 00000000004e6c1a
RDX: 0000000000000000 RSI: 0000000000000e1b RDI: 0000000000000018
RBP: 0000000000000018 R08: 0000000000000017 R09: 0000000000000016
R10: 0000000000000000 R11: 0000000000000206 R12: 00000000021e0cf0
R13: 0000000000000000 R14: 000000000000857f R15: 0000000000617180
 </TASK>
Code: 70 41 83 f8 03 c7 44 24 10 08 00 00 00 48 89 44 24 18 48 8d 44 24 30 8b 70 08 4c 0f 43 d1 48 89 44 24 20 b8 65 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3e 48 85 c0 78 06 41 83 f8 02 76 1b 48 8b 4c
RSP: 002b:00007ffeeade96b0 EFLAGS: 00000206 ORIG_RAX: 0000000000000065
RAX: ffffffffffffffda RBX: 00000000021df2f8 RCX: 00000000004e6c1a
RDX: 0000000000000000 RSI: 0000000000000e1b RDI: 0000000000000018
RBP: 0000000000000018 R08: 0000000000000017 R09: 0000000000000016
R10: 0000000000000000 R11: 0000000000000206 R12: 00000000021e0cf0
R13: 0000000000000000 R14: 000000000000857f R15: 0000000000617180
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 3606 Comm: strace-static-x Not tainted 5.19.0-syzkaller-02972-g200e340f2196 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x262/0x3f0 kernel/rcu/tree_stall.h:371
 print_cpu_stall kernel/rcu/tree_stall.h:660 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:744 [inline]
 rcu_pending kernel/rcu/tree.c:3660 [inline]
 rcu_sched_clock_irq.cold+0x404/0x77e kernel/rcu/tree.c:2342
 update_process_times+0x11a/0x1a0 kernel/time/timer.c:1839
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243
 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1480
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194
Code: 74 24 10 e8 7a ed e2 f7 48 89 ef e8 12 6f e3 f7 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 <e8> f3 70 d6 f7 65 8b 05 5c 98 87 76 85 c0 74 0a 5b 5d c3 e8 d0 83
RSP: 0018:ffffc900003f8b08 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff20db4f6
RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001
RBP: ffff8880210a8000 R08: 0000000000000001 R09: ffffffff9068ca0f
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888021b39440
R13: ffff8880170a0100 R14: dffffc0000000000 R15: ffff88807a36b300
 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline]
 dummy_timer+0x12f6/0x32b0 drivers/usb/gadget/udc/dummy_hcd.c:2002
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1474
 expire_timers kernel/time/timer.c:1519 [inline]
 __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1790
 __run_timers kernel/time/timer.c:1768 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:571
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:finish_task_switch.isra.0+0x2bf/0xc70 kernel/sched/core.c:5058
Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 60 f8 ff ff e8 7b 98 2e 00 fb 65 48 8b 1c 25 80 6f 02 00 <48> 8d bb 98 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc9000310fb38 EFLAGS: 00000206
RAX: 000000000007abc3 RBX: ffff88802499e180 RCX: 1ffffffff1b76681
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000310fb80 R08: 0000000000000001 R09: 0000000000000001
R10: ffffed1017367400 R11: 0000000000000001 R12: ffff8880b9b3a000
R13: ffff888022e641c0 R14: 0000000000000000 R15: ffff8880b9b3aa38
 context_switch kernel/sched/core.c:5181 [inline]
 __schedule+0xa08/0x4c10 kernel/sched/core.c:6490
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6659
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202
 spin_unlock_irq include/linux/spinlock.h:399 [inline]
 ptrace_resume kernel/ptrace.c:885 [inline]
 ptrace_request+0x2db/0x10c0 kernel/ptrace.c:1218
 arch_ptrace+0x36/0x510 arch/x86/kernel/ptrace.c:828
 __do_sys_ptrace kernel/ptrace.c:1296 [inline]
 __se_sys_ptrace kernel/ptrace.c:1269 [inline]
 __x64_sys_ptrace+0x178/0x2a0 kernel/ptrace.c:1269
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x4e6c1a
Code: 70 41 83 f8 03 c7 44 24 10 08 00 00 00 48 89 44 24 18 48 8d 44 24 30 8b 70 08 4c 0f 43 d1 48 89 44 24 20 b8 65 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3e 48 85 c0 78 06 41 83 f8 02 76 1b 48 8b 4c
RSP: 002b:00007ffeeade96b0 EFLAGS: 00000206 ORIG_RAX: 0000000000000065
RAX: ffffffffffffffda RBX: 00000000021df2f8 RCX: 00000000004e6c1a
RDX: 0000000000000000 RSI: 0000000000000e1b RDI: 0000000000000018
RBP: 0000000000000018 R08: 0000000000000017 R09: 0000000000000016
R10: 0000000000000000 R11: 0000000000000206 R12: 00000000021e0cf0
R13: 0000000000000000 R14: 000000000000857f R15: 0000000000617180
 </TASK>
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 6-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 1-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 3-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 3-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 3-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 2-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored
imon 3-1:0.0: imon usb_rx_callback_intf0: status(-71): ignored

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2022/11/04 12:51 upstream ee6050c8af96 1c9013ac .config log report syz C
* Struck through repros no longer work on HEAD.
Crashes (18):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2022/08/04 10:44 upstream 200e340f2196 1c9013ac .config log report syz C INFO: rcu detected stall in dummy_timer
ci-upstream-kasan-gce-smack-root 2022/07/05 03:47 upstream c1084b6c5620 bff65f44 .config log report syz C INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/07/30 00:21 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 8288c99fc263 fef302b1 .config log report syz C INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/07/29 21:58 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 8288c99fc263 fef302b1 .config log report syz C INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/07/22 15:36 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 32f02a211b0a 22343af4 .config log report syz C INFO: rcu detected stall in dummy_timer
ci-upstream-kasan-gce 2022/09/21 22:14 upstream 06f7db949993 380f82fb .config log report info INFO: rcu detected stall in dummy_timer
ci-upstream-kasan-gce-root 2022/09/10 04:53 upstream ce888220d5c7 356d8217 .config log report info INFO: rcu detected stall in dummy_timer
ci-upstream-kasan-gce-smack-root 2022/08/26 21:24 upstream 3e5c673f0d75 e5a303f1 .config log report info INFO: rcu detected stall in dummy_timer
ci-upstream-kasan-gce-root 2022/08/17 23:43 upstream 274a2eebf80c 4e72d229 .config log report info INFO: rcu detected stall in dummy_timer
ci-upstream-kasan-gce-386 2022/07/18 12:41 upstream ff6992735ade ff988920 .config log report info INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/09/17 11:10 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 7eb2bf871454 dd9a85ff .config log report info INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/09/13 17:41 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 7eb2bf871454 a08652b0 .config log report info INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/09/09 08:09 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 7eb2bf871454 f3027468 .config log report info INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/08/19 11:45 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing ffcf9c5700e4 26a13b38 .config log report info INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/08/19 03:19 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing ffcf9c5700e4 26a13b38 .config log report info INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/08/11 12:41 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing ffcf9c5700e4 787ed7e0 .config log report info INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/07/14 15:18 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing ddc509e940ba 5d921b08 .config log report info INFO: rcu detected stall in dummy_timer
ci2-upstream-usb 2022/07/13 16:16 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 8affe37c525d 5d921b08 .config log report info INFO: rcu detected stall in dummy_timer
* Struck through repros no longer work on HEAD.