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possible deadlock in scheduler_tick

Status: fixed on 2022/03/16 16:02
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+b282b65c2c68492df769@syzkaller.appspotmail.com
Fix commit: a83829f56c7c KVM: x86: disable interrupts while pvclock_gtod_sync_lock is taken 8228c77d8b56 KVM: x86: switch pvclock_gtod_sync_lock to a raw spinlock
First crash: 1132d, last: 1116d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ Duplicate bugs (1)
duplicates (1):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
possible deadlock in kvm_synchronize_tsc kvm C unreliable 4 1131d 1128d 0/26 closed as dup on 2021/03/24 12:17
▶ ▼ Discussions (3)
Title Replies (including bot) Last reply
[PATCH 5.14 000/125] 5.14.16-rc1 review 130 (130) 2021/11/02 07:19
[PATCH 0/2] KVM: x86: fix lockdep splat due to Xen runstate update 14 (14) 2021/10/25 12:15
[syzbot] possible deadlock in scheduler_tick 2 (3) 2021/03/24 12:19
▶ ▼ Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in scheduler_tick (2) ntfs3 C 10 324d 341d 23/26 fixed on 2023/09/28 17:51
linux-6.1 possible deadlock in scheduler_tick origin:upstream C 237 15d 36d 0/3 upstream: reported C repro on 2024/03/20 00:02
upstream possible deadlock in scheduler_tick (3) bpf net C 1174 47m 35d 24/26 upstream: reported C repro on 2024/03/20 18:46
linux-5.15 possible deadlock in scheduler_tick C 162 15d 39d 0/3 upstream: reported C repro on 2024/03/16 21:21

Sample crash report:
=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
5.12.0-rc3-syzkaller #0 Not tainted
-----------------------------------------------------
syz-executor030/8435 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffffc90001a2a230 (&kvm->arch.pvclock_gtod_sync_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline]
ffffc90001a2a230 (&kvm->arch.pvclock_gtod_sync_lock){+.+.}-{2:2}, at: get_kvmclock_ns+0x25/0x390 arch/x86/kvm/x86.c:2587

and this task is already holding:
ffff8880b9d35198 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1321 [inline]
ffff8880b9d35198 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x21c/0x21b0 kernel/sched/core.c:4990
which would create a new lock dependency:
 (&rq->lock){-.-.}-{2:2} -> (&kvm->arch.pvclock_gtod_sync_lock){+.+.}-{2:2}

but this new dependency connects a HARDIRQ-irq-safe lock:
 (&rq->lock){-.-.}-{2:2}

... which became HARDIRQ-irq-safe at:
  lock_acquire kernel/locking/lockdep.c:5510 [inline]
  lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
  __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
  _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
  rq_lock kernel/sched/sched.h:1321 [inline]
  scheduler_tick+0xa4/0x4b0 kernel/sched/core.c:4538
  update_process_times+0x191/0x200 kernel/time/timer.c:1801
  tick_periodic+0x79/0x230 kernel/time/tick-common.c:100
  tick_handle_periodic+0x41/0x120 kernel/time/tick-common.c:112
  timer_interrupt+0x3f/0x60 arch/x86/kernel/time.c:57
  __handle_irq_event_percpu+0x303/0x8f0 kernel/irq/handle.c:156
  handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
  handle_irq_event+0x102/0x290 kernel/irq/handle.c:213
  handle_level_irq+0x256/0x6e0 kernel/irq/chip.c:650
  generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
  handle_irq arch/x86/kernel/irq.c:231 [inline]
  __common_interrupt+0x9e/0x200 arch/x86/kernel/irq.c:250
  common_interrupt+0x9f/0xd0 arch/x86/kernel/irq.c:240
  asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:623
  __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
  _raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191
  __setup_irq+0xc72/0x1ce0 kernel/irq/manage.c:1737
  request_threaded_irq+0x28a/0x3b0 kernel/irq/manage.c:2127
  request_irq include/linux/interrupt.h:160 [inline]
  setup_default_timer_irq arch/x86/kernel/time.c:70 [inline]
  hpet_time_init+0x28/0x42 arch/x86/kernel/time.c:82
  x86_late_time_init+0x58/0x94 arch/x86/kernel/time.c:94
  start_kernel+0x3ee/0x496 init/main.c:1028
  secondary_startup_64_no_verify+0xb0/0xbb

to a HARDIRQ-irq-unsafe lock:
 (&kvm->arch.pvclock_gtod_sync_lock){+.+.}-{2:2}

... which became HARDIRQ-irq-unsafe at:
...
  lock_acquire kernel/locking/lockdep.c:5510 [inline]
  lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
  __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
  _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
  spin_lock include/linux/spinlock.h:354 [inline]
  kvm_synchronize_tsc+0x459/0x1230 arch/x86/kvm/x86.c:2332
  kvm_arch_vcpu_postcreate+0x73/0x180 arch/x86/kvm/x86.c:10183
  kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3239 [inline]
  kvm_vm_ioctl+0x1b2d/0x2800 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3839
  kvm_vm_compat_ioctl+0x125/0x230 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4052
  __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
  do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline]
  __do_fast_syscall_32+0x56/0x90 arch/x86/entry/common.c:140
  do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:165
  entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&kvm->arch.pvclock_gtod_sync_lock);
                               local_irq_disable();
                               lock(&rq->lock);
                               lock(&kvm->arch.pvclock_gtod_sync_lock);
  <Interrupt>
    lock(&rq->lock);

 *** DEADLOCK ***

1 lock held by syz-executor030/8435:
 #0: ffff8880b9d35198 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1321 [inline]
 #0: ffff8880b9d35198 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x21c/0x21b0 kernel/sched/core.c:4990

the dependencies between HARDIRQ-irq-safe lock and the holding lock:
-> (&rq->lock){-.-.}-{2:2} {
   IN-HARDIRQ-W at:
                    lock_acquire kernel/locking/lockdep.c:5510 [inline]
                    lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
                    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                    _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
                    rq_lock kernel/sched/sched.h:1321 [inline]
                    scheduler_tick+0xa4/0x4b0 kernel/sched/core.c:4538
                    update_process_times+0x191/0x200 kernel/time/timer.c:1801
                    tick_periodic+0x79/0x230 kernel/time/tick-common.c:100
                    tick_handle_periodic+0x41/0x120 kernel/time/tick-common.c:112
                    timer_interrupt+0x3f/0x60 arch/x86/kernel/time.c:57
                    __handle_irq_event_percpu+0x303/0x8f0 kernel/irq/handle.c:156
                    handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
                    handle_irq_event+0x102/0x290 kernel/irq/handle.c:213
                    handle_level_irq+0x256/0x6e0 kernel/irq/chip.c:650
                    generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
                    handle_irq arch/x86/kernel/irq.c:231 [inline]
                    __common_interrupt+0x9e/0x200 arch/x86/kernel/irq.c:250
                    common_interrupt+0x9f/0xd0 arch/x86/kernel/irq.c:240
                    asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:623
                    __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
                    _raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191
                    __setup_irq+0xc72/0x1ce0 kernel/irq/manage.c:1737
                    request_threaded_irq+0x28a/0x3b0 kernel/irq/manage.c:2127
                    request_irq include/linux/interrupt.h:160 [inline]
                    setup_default_timer_irq arch/x86/kernel/time.c:70 [inline]
                    hpet_time_init+0x28/0x42 arch/x86/kernel/time.c:82
                    x86_late_time_init+0x58/0x94 arch/x86/kernel/time.c:94
                    start_kernel+0x3ee/0x496 init/main.c:1028
                    secondary_startup_64_no_verify+0xb0/0xbb
   IN-SOFTIRQ-W at:
                    lock_acquire kernel/locking/lockdep.c:5510 [inline]
                    lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
                    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                    _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
                    rq_lock kernel/sched/sched.h:1321 [inline]
                    ttwu_queue kernel/sched/core.c:3184 [inline]
                    try_to_wake_up+0x5e6/0x14a0 kernel/sched/core.c:3464
                    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
                    invoke_softirq kernel/softirq.c:221 [inline]
                    __irq_exit_rcu kernel/softirq.c:422 [inline]
                    irq_exit_rcu+0x134/0x200 kernel/softirq.c:434
                    sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
                    asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
                    rdtsc_ordered arch/x86/include/asm/msr.h:234 [inline]
                    delay_tsc+0x45/0xb0 arch/x86/lib/delay.c:72
                    try_check_zero+0x223/0x430 kernel/rcu/srcutree.c:707
                    srcu_advance_state kernel/rcu/srcutree.c:1229 [inline]
                    process_srcu+0x2f2/0xe90 kernel/rcu/srcutree.c:1327
                    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
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5510 [inline]
                   lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
                   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
                   _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159
                   rq_attach_root+0x20/0x2e0 kernel/sched/topology.c:470
                   sched_init+0x6e8/0xbf3 kernel/sched/core.c:8213
                   start_kernel+0x18e/0x496 init/main.c:920
                   secondary_startup_64_no_verify+0xb0/0xbb
 }
 ... key      at: [<ffffffff8f39a7c0>] __key.298+0x0/0x40
 ... acquired at:
   lock_acquire kernel/locking/lockdep.c:5510 [inline]
   lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
   _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
   spin_lock include/linux/spinlock.h:354 [inline]
   get_kvmclock_ns+0x25/0x390 arch/x86/kvm/x86.c:2587
   kvm_xen_update_runstate+0x3d/0x2c0 arch/x86/kvm/xen.c:69
   kvm_xen_update_runstate_guest+0x74/0x320 arch/x86/kvm/xen.c:100
   kvm_xen_runstate_set_preempted arch/x86/kvm/xen.h:96 [inline]
   kvm_arch_vcpu_put+0x2d8/0x5a0 arch/x86/kvm/x86.c:4062
   kvm_sched_out+0xbf/0x100 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4876
   __fire_sched_out_preempt_notifiers kernel/sched/core.c:3922 [inline]
   fire_sched_out_preempt_notifiers kernel/sched/core.c:3930 [inline]
   prepare_task_switch kernel/sched/core.c:4126 [inline]
   context_switch kernel/sched/core.c:4274 [inline]
   __schedule+0xfd0/0x21b0 kernel/sched/core.c:5073
   preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5530
   irqentry_exit_cond_resched kernel/entry/common.c:392 [inline]
   irqentry_exit_cond_resched kernel/entry/common.c:384 [inline]
   irqentry_exit+0x7a/0xa0 kernel/entry/common.c:428
   asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
   __vmcs_writel arch/x86/kvm/vmx/vmx_ops.h:176 [inline]
   vmcs_write16 arch/x86/kvm/vmx/vmx_ops.h:185 [inline]
   seg_setup+0x66/0x2a0 arch/x86/kvm/vmx/vmx.c:3633
   vmx_vcpu_reset+0x20a/0xee0 arch/x86/kvm/vmx/vmx.c:4455
   kvm_arch_vcpu_create+0x765/0xbb0 arch/x86/kvm/x86.c:10152
   kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3201 [inline]
   kvm_vm_ioctl+0x1702/0x2800 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3839
   kvm_vm_compat_ioctl+0x125/0x230 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4052
   __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
   do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline]
   __do_fast_syscall_32+0x56/0x90 arch/x86/entry/common.c:140
   do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:165
   entry_SYSENTER_compat_after_hwframe+0x4d/0x5c


the dependencies between the lock to be acquired
 and HARDIRQ-irq-unsafe lock:
-> (&kvm->arch.pvclock_gtod_sync_lock){+.+.}-{2:2} {
   HARDIRQ-ON-W at:
                    lock_acquire kernel/locking/lockdep.c:5510 [inline]
                    lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
                    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                    _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
                    spin_lock include/linux/spinlock.h:354 [inline]
                    kvm_synchronize_tsc+0x459/0x1230 arch/x86/kvm/x86.c:2332
                    kvm_arch_vcpu_postcreate+0x73/0x180 arch/x86/kvm/x86.c:10183
                    kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3239 [inline]
                    kvm_vm_ioctl+0x1b2d/0x2800 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3839
                    kvm_vm_compat_ioctl+0x125/0x230 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4052
                    __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
                    do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline]
                    __do_fast_syscall_32+0x56/0x90 arch/x86/entry/common.c:140
                    do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:165
                    entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
   SOFTIRQ-ON-W at:
                    lock_acquire kernel/locking/lockdep.c:5510 [inline]
                    lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
                    __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                    _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
                    spin_lock include/linux/spinlock.h:354 [inline]
                    kvm_synchronize_tsc+0x459/0x1230 arch/x86/kvm/x86.c:2332
                    kvm_arch_vcpu_postcreate+0x73/0x180 arch/x86/kvm/x86.c:10183
                    kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3239 [inline]
                    kvm_vm_ioctl+0x1b2d/0x2800 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3839
                    kvm_vm_compat_ioctl+0x125/0x230 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4052
                    __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
                    do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline]
                    __do_fast_syscall_32+0x56/0x90 arch/x86/entry/common.c:140
                    do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:165
                    entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5510 [inline]
                   lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
                   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
                   _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
                   spin_lock include/linux/spinlock.h:354 [inline]
                   kvm_synchronize_tsc+0x459/0x1230 arch/x86/kvm/x86.c:2332
                   kvm_arch_vcpu_postcreate+0x73/0x180 arch/x86/kvm/x86.c:10183
                   kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3239 [inline]
                   kvm_vm_ioctl+0x1b2d/0x2800 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3839
                   kvm_vm_compat_ioctl+0x125/0x230 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4052
                   __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
                   do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline]
                   __do_fast_syscall_32+0x56/0x90 arch/x86/entry/common.c:140
                   do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:165
                   entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
 }
 ... key      at: [<ffffffff8f371000>] __key.4+0x0/0x40
 ... acquired at:
   lock_acquire kernel/locking/lockdep.c:5510 [inline]
   lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
   __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
   _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
   spin_lock include/linux/spinlock.h:354 [inline]
   get_kvmclock_ns+0x25/0x390 arch/x86/kvm/x86.c:2587
   kvm_xen_update_runstate+0x3d/0x2c0 arch/x86/kvm/xen.c:69
   kvm_xen_update_runstate_guest+0x74/0x320 arch/x86/kvm/xen.c:100
   kvm_xen_runstate_set_preempted arch/x86/kvm/xen.h:96 [inline]
   kvm_arch_vcpu_put+0x2d8/0x5a0 arch/x86/kvm/x86.c:4062
   kvm_sched_out+0xbf/0x100 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4876
   __fire_sched_out_preempt_notifiers kernel/sched/core.c:3922 [inline]
   fire_sched_out_preempt_notifiers kernel/sched/core.c:3930 [inline]
   prepare_task_switch kernel/sched/core.c:4126 [inline]
   context_switch kernel/sched/core.c:4274 [inline]
   __schedule+0xfd0/0x21b0 kernel/sched/core.c:5073
   preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5530
   irqentry_exit_cond_resched kernel/entry/common.c:392 [inline]
   irqentry_exit_cond_resched kernel/entry/common.c:384 [inline]
   irqentry_exit+0x7a/0xa0 kernel/entry/common.c:428
   asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
   __vmcs_writel arch/x86/kvm/vmx/vmx_ops.h:176 [inline]
   vmcs_write16 arch/x86/kvm/vmx/vmx_ops.h:185 [inline]
   seg_setup+0x66/0x2a0 arch/x86/kvm/vmx/vmx.c:3633
   vmx_vcpu_reset+0x20a/0xee0 arch/x86/kvm/vmx/vmx.c:4455
   kvm_arch_vcpu_create+0x765/0xbb0 arch/x86/kvm/x86.c:10152
   kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3201 [inline]
   kvm_vm_ioctl+0x1702/0x2800 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3839
   kvm_vm_compat_ioctl+0x125/0x230 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4052
   __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
   do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline]
   __do_fast_syscall_32+0x56/0x90 arch/x86/entry/common.c:140
   do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:165
   entry_SYSENTER_compat_after_hwframe+0x4d/0x5c


stack backtrace:
CPU: 1 PID: 8435 Comm: syz-executor030 Not tainted 5.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_bad_irq_dependency kernel/locking/lockdep.c:2460 [inline]
 check_irq_usage.cold+0x50d/0x744 kernel/locking/lockdep.c:2689
 check_prev_add kernel/locking/lockdep.c:2940 [inline]
 check_prevs_add kernel/locking/lockdep.c:3059 [inline]
 validate_chain kernel/locking/lockdep.c:3674 [inline]
 __lock_acquire+0x2b2c/0x54c0 kernel/locking/lockdep.c:4900
 lock_acquire kernel/locking/lockdep.c:5510 [inline]
 lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:354 [inline]
 get_kvmclock_ns+0x25/0x390 arch/x86/kvm/x86.c:2587
 kvm_xen_update_runstate+0x3d/0x2c0 arch/x86/kvm/xen.c:69
 kvm_xen_update_runstate_guest+0x74/0x320 arch/x86/kvm/xen.c:100
 kvm_xen_runstate_set_preempted arch/x86/kvm/xen.h:96 [inline]
 kvm_arch_vcpu_put+0x2d8/0x5a0 arch/x86/kvm/x86.c:4062
 kvm_sched_out+0xbf/0x100 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4876
 __fire_sched_out_preempt_notifiers kernel/sched/core.c:3922 [inline]
 fire_sched_out_preempt_notifiers kernel/sched/core.c:3930 [inline]
 prepare_task_switch kernel/sched/core.c:4126 [inline]
 context_switch kernel/sched/core.c:4274 [inline]
 __schedule+0xfd0/0x21b0 kernel/sched/core.c:5073
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:5530
 irqentry_exit_cond_resched kernel/entry/common.c:392 [inline]
 irqentry_exit_cond_resched kernel/entry/common.c:384 [inline]
 irqentry_exit+0x7a/0xa0 kernel/entry/common.c:428
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:__vmcs_writel arch/x86/kvm/vmx/vmx_ops.h:176 [inline]
RIP: 0010:vmcs_write16 arch/x86/kvm/vmx/vmx_ops.h:185 [inline]
RIP: 0010:seg_setup+0x66/0x2a0 arch/x86/kvm/vmx/vmx.c:3633
Code: 84 c0 74 08 3c 03 0f 8e 32 02 00 00 48 89 d8 48 c1 e0 04 44 8b a0 80 72 64 89 0f 1f 44 00 00 e8 d0 31 56 00 31 c0 44 0f 79 e0 <2e> 0f 86 db 01 00 00 e8 be 31 56 00 e8 b9 31 56 00 48 89 df 48 b8
RSP: 0018:ffffc9000183f988 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801ba39c40 RSI: ffffffff811db9b0 RDI: ffffffff89647280
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffc90001a2a16b
R10: ffffffff811dba9b R11: 0000000000000000 R12: 0000000000000800
R13: 1ffff92000307f35 R14: ffff88801755e170 R15: 0000000000000040
 vmx_vcpu_reset+0x20a/0xee0 arch/x86/kvm/vmx/vmx.c:4455
 kvm_arch_vcpu_create+0x765/0xbb0 arch/x86/kvm/x86.c:10152
 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3201 [inline]
 kvm_vm_ioctl+0x1702/0x2800 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3839
 kvm_vm_compat_ioctl+0x125/0x230 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4052
 __do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
 do_syscall_32_irqs_on arch/x86/entry/common.c:77 [inline]
 __do_fast_syscall_32+0x56/0x90 arch/x86/entry/common.c:140
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:165
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f50549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000ffce641c EFLAGS: 00000217 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000000ae41
RDX: 0000000000000000 RSI: 0000000000000036 RDI: 0000000000000004
RBP: 000000004038ae7a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Crashes (99):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/03/20 17:46 upstream 1c273e10bc0c 17810eae .config console log report syz C ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/04/02 02:08 upstream ffd9fb546d49 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/04/01 20:13 upstream ffd9fb546d49 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/04/01 19:12 upstream ffd9fb546d49 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/04/01 05:49 upstream d19cc4bfbff1 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/04/01 04:11 upstream d19cc4bfbff1 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/31 20:32 upstream 5e46d1b78a03 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/31 13:37 upstream 5e46d1b78a03 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/31 12:15 upstream 5e46d1b78a03 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/31 10:14 upstream 2bb25b3a748a 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/31 08:43 upstream 2bb25b3a748a 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/30 07:46 upstream 1e43c377a79f 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/29 20:57 upstream 1e43c377a79f 6a81331a .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/29 14:01 upstream a5e13c6df0e4 a8529b82 .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/29 04:44 upstream 81b1d39fd39a a8529b82 .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in scheduler_tick
2021/03/26 19:25 upstream db24726bfefa a8529b82 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/26 17:40 upstream db24726bfefa a8529b82 .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/26 11:05 upstream db24726bfefa 6a383ecf .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/25 19:46 upstream e138138003eb 6a383ecf .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/25 18:42 upstream e138138003eb 6a383ecf .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/24 20:53 upstream 4ee998b0ef8b 607e3baf .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/24 18:09 upstream 7acac4b3196c 607e3baf .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/24 15:20 upstream 7acac4b3196c 607e3baf .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/23 20:30 upstream 7acac4b3196c e613994b .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/23 18:12 upstream 7acac4b3196c e613994b .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/23 17:01 upstream 84196390620a e613994b .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/23 16:05 upstream 84196390620a e613994b .config console log report info ci-upstream-kasan-gce-smack-root possible deadlock in scheduler_tick
2021/03/23 02:04 upstream 84196390620a 8092f30d .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/23 01:06 upstream 84196390620a 8092f30d .config console log report info ci-upstream-kasan-gce-selinux-root possible deadlock in scheduler_tick
2021/03/20 06:40 upstream 1c273e10bc0c 3d01c4de .config console log report info ci-upstream-kasan-gce possible deadlock in scheduler_tick
2021/03/31 15:36 upstream 5e46d1b78a03 6a81331a .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/30 22:34 upstream 2bb25b3a748a 6a81331a .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/29 23:06 upstream 1e43c377a79f 6a81331a .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/29 16:24 upstream a5e13c6df0e4 a8529b82 .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/29 01:19 upstream 36a14638f7c0 a8529b82 .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/28 22:37 upstream 36a14638f7c0 a8529b82 .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/27 10:42 upstream 0f4498cef9f5 a8529b82 .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/27 09:17 upstream 0f4498cef9f5 a8529b82 .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/26 15:28 upstream db24726bfefa a8529b82 .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/26 10:21 upstream db24726bfefa 6a383ecf .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/26 09:16 upstream db24726bfefa 6a383ecf .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/26 08:09 upstream db24726bfefa 6a383ecf .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/25 21:05 upstream e138138003eb 6a383ecf .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/25 09:56 upstream 4ee998b0ef8b 607e3baf .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/25 00:47 upstream 4ee998b0ef8b 607e3baf .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/23 22:51 upstream 7acac4b3196c e613994b .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/23 21:49 upstream 7acac4b3196c e613994b .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/23 21:27 upstream 7acac4b3196c e613994b .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/03/23 16:49 upstream 84196390620a e613994b .config console log report info ci-upstream-kasan-gce-386 possible deadlock in scheduler_tick
2021/04/05 05:15 linux-next 454c576c3f5e 6a81331a .config console log report info ci-upstream-linux-next-kasan-gce-root possible deadlock in scheduler_tick
2021/03/25 07:43 linux-next 20f1b5f9c07c 607e3baf .config console log report info ci-upstream-linux-next-kasan-gce-root possible deadlock in scheduler_tick
* Struck through repros no longer work on HEAD.