INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-next-kasan-gce-0,10.128.0.24' (ECDSA) to the list of known hosts. 2017/08/24 07:38:21 parsed 1 programs 2017/08/24 07:38:21 executed programs: 0 syzkaller login: [ 36.484861] kvm: KVM_SET_TSS_ADDR need to be called before entering vcpu [ 40.736478] [ 40.738116] ====================================================== [ 40.744408] WARNING: possible circular locking dependency detected [ 40.750699] 4.13.0-rc6-next-20170823+ #7 Not tainted [ 40.755772] ------------------------------------------------------ [ 40.762060] kworker/0:1/24 is trying to acquire lock: [ 40.767217] ((shepherd).work){+.+.}, at: [] process_one_work+0xb2c/0x1be0 [ 40.775778] [ 40.775778] but now in release context of a crosslock acquired at the following: [ 40.784765] ((complete)&rcu.completion){+.+.}, at: [] __synchronize_srcu+0x1b5/0x250 [ 40.794370] [ 40.794370] which lock already depends on the new lock. [ 40.794370] [ 40.802667] [ 40.802667] the existing dependency chain (in reverse order) is: [ 40.810261] [ 40.810261] -> #2 ((complete)&rcu.completion){+.+.}: [ 40.816834] __lock_acquire+0x3286/0x4620 [ 40.821478] lock_acquire+0x1d5/0x580 [ 40.825773] wait_for_completion+0xc8/0x770 [ 40.831133] __synchronize_srcu+0x1b5/0x250 [ 40.835953] synchronize_srcu+0x1a3/0x560 [ 40.840596] quarantine_remove_cache+0xd7/0xf0 [ 40.845674] kasan_cache_shrink+0x9/0x10 [ 40.850229] kmem_cache_shrink+0x15/0x30 [ 40.854785] acpi_os_purge_cache+0x15/0x20 [ 40.859518] acpi_purge_cached_objects+0x38/0xc9 [ 40.864768] acpi_initialize_objects+0xc5/0x112 [ 40.869931] acpi_init+0x23c/0x8e6 [ 40.873965] do_one_initcall+0x9e/0x330 [ 40.878436] kernel_init_freeable+0x46e/0x526 [ 40.883422] kernel_init+0x13/0x172 [ 40.887542] ret_from_fork+0x2a/0x40 [ 40.891746] [ 40.891746] -> #1 (cpu_hotplug_lock.rw_sem){++++}: [ 40.898138] __lock_acquire+0x3286/0x4620 [ 40.902781] lock_acquire+0x1d5/0x580 [ 40.907084] cpus_read_lock+0x42/0x90 [ 40.911383] vmstat_shepherd+0x3d/0x1b0 [ 40.915851] process_one_work+0xbfd/0x1be0 [ 40.920577] worker_thread+0x223/0x1860 [ 40.925044] kthread+0x39c/0x470 [ 40.928906] ret_from_fork+0x2a/0x40 [ 40.933110] [ 40.933110] -> #0 ((shepherd).work){+.+.}: [ 40.938807] process_one_work+0xba5/0x1be0 [ 40.943534] worker_thread+0x223/0x1860 [ 40.947999] kthread+0x39c/0x470 [ 40.951862] ret_from_fork+0x2a/0x40 [ 40.956071] 0xffffffffffffffff [ 40.959842] [ 40.959842] other info that might help us debug this: [ 40.959842] [ 40.967957] Chain exists of: [ 40.967957] (shepherd).work --> cpu_hotplug_lock.rw_sem --> (complete)&rcu.completion [ 40.967957] [ 40.981206] Possible unsafe locking scenario by crosslock: [ 40.981206] [ 40.988364] CPU0 CPU1 [ 40.993000] ---- ---- [ 40.997733] lock(cpu_hotplug_lock.rw_sem); [ 41.002115] lock((complete)&rcu.completion); [ 41.006670] lock((shepherd).work); [ 41.012879] unlock((complete)&rcu.completion); [ 41.020131] [ 41.020131] *** DEADLOCK *** [ 41.020131] [ 41.026254] 3 locks held by kworker/0:1/24: [ 41.030544] #0: ("events_power_efficient"){.+.+}, at: [] process_one_work+0xad4/0x1be0 [ 41.040407] #1: ((&(&sdp->work)->work)){+.+.}, at: [] process_one_work+0xb2c/0x1be0 [ 41.049919] #2: (&x->wait#5){....}, at: [] complete+0x18/0x80 [ 41.057525] [ 41.057525] stack backtrace: [ 41.061998] CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.13.0-rc6-next-20170823+ #7 [ 41.069937] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.079275] Workqueue: events_power_efficient srcu_invoke_callbacks [ 41.085652] Call Trace: [ 41.088217] dump_stack+0x194/0x257 [ 41.091820] ? arch_local_irq_restore+0x53/0x53 [ 41.096471] print_circular_bug+0x503/0x710 [ 41.100769] ? print_circular_bug_entry+0xb0/0xb0 [ 41.105588] check_prev_add+0x865/0x1520 [ 41.109628] ? graph_lock+0x170/0x170 [ 41.113415] ? check_usage+0xb70/0xb70 [ 41.117280] ? find_held_lock+0x39/0x1d0 [ 41.121321] ? hlock_class+0x140/0x140 [ 41.125182] ? lock_downgrade+0x990/0x990 [ 41.129301] ? check_noncircular+0x20/0x20 [ 41.133511] lock_commit_crosslock+0xe73/0x1d10 [ 41.138156] ? lock_commit_crosslock+0xe73/0x1d10 [ 41.142970] ? check_noncircular+0x20/0x20 [ 41.147217] ? check_prev_add+0x1520/0x1520 [ 41.151515] ? lock_acquire+0x1d5/0x580 [ 41.155461] ? complete+0x18/0x80 [ 41.158893] ? lock_release+0xd70/0xd70 [ 41.162842] ? check_noncircular+0x20/0x20 [ 41.167056] ? do_raw_spin_trylock+0x190/0x190 [ 41.171618] complete+0x24/0x80 [ 41.174871] wakeme_after_rcu+0xd/0x10 [ 41.178733] srcu_invoke_callbacks+0x280/0x4d0 [ 41.183292] ? srcu_queue_delayed_work_on+0x240/0x240 [ 41.188461] ? __lock_is_held+0xbc/0x140 [ 41.192500] process_one_work+0xbfd/0x1be0 [ 41.196709] ? check_noncircular+0x20/0x20 [ 41.200922] ? pwq_dec_nr_in_flight+0x450/0x450 [ 41.205565] ? finish_task_switch+0x1d3/0x740 [ 41.210048] ? __sched_text_start+0x8/0x8 [ 41.214169] ? unwind_dump+0x4c0/0x4c0 [ 41.218032] ? check_noncircular+0x20/0x20 [ 41.222238] ? __unwind_start+0x169/0x330 [ 41.226365] ? find_held_lock+0x39/0x1d0 [ 41.230409] ? lock_acquire+0x1d5/0x580 [ 41.234355] ? worker_thread+0x4a3/0x1860 [ 41.238476] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 41.243207] ? lock_release+0xd70/0xd70 [ 41.247153] ? do_raw_spin_trylock+0x190/0x190 [ 41.251713] ? retint_kernel+0x10/0x10 [ 41.255580] worker_thread+0x223/0x1860 [ 41.259536] ? process_one_work+0x1be0/0x1be0 [ 41.264007] ? check_noncircular+0x20/0x20 [ 41.268216] ? _raw_spin_unlock_irq+0x27/0x70 [ 41.272687] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.277676] ? trace_hardirqs_on+0xd/0x10 [ 41.281798] ? _raw_spin_unlock_irq+0x27/0x70 [ 41.286267] ? finish_task_switch+0x1d3/0x740 [ 41.290745] ? finish_task_switch+0x1aa/0x740 [ 41.295214] ? preempt_notifier_dec+0x20/0x20 [ 41.299692] ? __schedule+0x8f0/0x2070 [ 41.303556] ? try_to_wake_up+0xf9/0x1600 [ 41.307683] ? find_held_lock+0x39/0x1d0 [ 41.311725] ? lock_downgrade+0x990/0x990 [ 41.315849] ? complete+0x18/0x80 [ 41.319281] ? __schedule+0x2070/0x2070 [ 41.323233] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 41.328314] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.333304] ? trace_hardirqs_on+0xd/0x10 [ 41.337428] ? __kthread_parkme+0x173/0x240 [ 41.341724] kthread+0x39c/0x470 [ 41.345675] ? process_one_work+0x1be0/0x1be0 [ 41.350317] ? kthread_create_on_node+0x100/0x100 [ 41.355137] ret_from_fork+0x2a/0x40 2017/08/24 07:38:26 executed programs: 270