2017/08/23 08:31:10 parsed 1 programs 2017/08/23 08:31:10 executed programs: 0 syzkaller login: [ 31.248200] hrtimer: interrupt took 417320 ns 2017/08/23 08:31:15 executed programs: 677 [ 36.777296] [ 36.777628] ====================================================== [ 36.778267] WARNING: possible circular locking dependency detected [ 36.778914] 4.13.0-rc6-next-20170823+ #7 Not tainted [ 36.779472] ------------------------------------------------------ [ 36.780125] kworker/0:1/36 is trying to acquire lock: [ 36.780618] ((shepherd).work){+.+.}, at: [] process_one_work+0xb2c/0x1be0 [ 36.781307] [ 36.781307] but now in release context of a crosslock acquired at the following: [ 36.782251] ((complete)&rcu.completion){+.+.}, at: [] __synchronize_srcu+0x1b5/0x250 [ 36.783182] [ 36.783182] which lock already depends on the new lock. [ 36.783182] [ 36.783756] [ 36.783756] the existing dependency chain (in reverse order) is: [ 36.784420] [ 36.784420] -> #2 ((complete)&rcu.completion){+.+.}: [ 36.784880] __lock_acquire+0x3286/0x4620 [ 36.785314] lock_acquire+0x1d5/0x580 [ 36.785786] wait_for_completion+0xc8/0x770 [ 36.786295] __synchronize_srcu+0x1b5/0x250 [ 36.786817] synchronize_srcu+0x1a3/0x560 [ 36.787330] quarantine_remove_cache+0xd7/0xf0 [ 36.787868] kasan_cache_shrink+0x9/0x10 [ 36.788325] kmem_cache_shrink+0x15/0x30 [ 36.788706] acpi_os_purge_cache+0x15/0x20 [ 36.789115] acpi_purge_cached_objects+0x38/0xc9 [ 36.789549] acpi_initialize_objects+0xc5/0x112 [ 36.790068] acpi_init+0x23c/0x8e6 [ 36.790966] do_one_initcall+0x9e/0x330 [ 36.791776] kernel_init_freeable+0x46e/0x526 [ 36.792687] kernel_init+0x13/0x172 [ 36.793468] ret_from_fork+0x2a/0x40 [ 36.794250] [ 36.794250] -> #1 (cpu_hotplug_lock.rw_sem){++++}: [ 36.795450] __lock_acquire+0x3286/0x4620 [ 36.796316] lock_acquire+0x1d5/0x580 [ 36.797115] cpus_read_lock+0x42/0x90 [ 36.797886] vmstat_shepherd+0x3d/0x1b0 [ 36.798664] process_one_work+0xbfd/0x1be0 [ 36.799511] worker_thread+0x223/0x1860 [ 36.800272] kthread+0x39c/0x470 [ 36.800972] ret_from_fork+0x2a/0x40 [ 36.801749] [ 36.801749] -> #0 ((shepherd).work){+.+.}: [ 36.802791] process_one_work+0xba5/0x1be0 [ 36.803665] worker_thread+0x223/0x1860 [ 36.804493] kthread+0x39c/0x470 [ 36.805212] ret_from_fork+0x2a/0x40 [ 36.805995] 0xffffffffffffffff [ 36.806641] [ 36.806641] other info that might help us debug this: [ 36.806641] [ 36.808156] Chain exists of: [ 36.808156] (shepherd).work --> cpu_hotplug_lock.rw_sem --> (complete)&rcu.completion [ 36.808156] [ 36.810473] Possible unsafe locking scenario by crosslock: [ 36.810473] [ 36.812050] CPU0 CPU1 [ 36.817448] ---- ---- [ 36.818377] lock(cpu_hotplug_lock.rw_sem); [ 36.819267] lock((complete)&rcu.completion); [ 36.820143] lock((shepherd).work); [ 36.821374] unlock((complete)&rcu.completion); [ 36.822714] [ 36.822714] *** DEADLOCK *** [ 36.822714] [ 36.824049] 3 locks held by kworker/0:1/36: [ 36.824806] #0: ("events_power_efficient"){.+.+}, at: [] process_one_work+0xad4/0x1be0 [ 36.826413] #1: ((&(&sdp->work)->work)){+.+.}, at: [] process_one_work+0xb2c/0x1be0 [ 36.827913] #2: (&x->wait#5){....}, at: [] complete+0x18/0x80 [ 36.829112] [ 36.829112] stack backtrace: [ 36.829967] CPU: 0 PID: 36 Comm: kworker/0:1 Not tainted 4.13.0-rc6-next-20170823+ #7 [ 36.831367] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 36.832588] Workqueue: events_power_efficient srcu_invoke_callbacks [ 36.834685] Call Trace: [ 36.835183] dump_stack+0x194/0x257 [ 36.835809] ? arch_local_irq_restore+0x53/0x53 [ 36.836518] print_circular_bug+0x503/0x710 [ 36.837370] ? print_circular_bug_entry+0xb0/0xb0 [ 36.838106] check_prev_add+0x865/0x1520 [ 36.838705] ? _raw_spin_unlock_irq+0x27/0x70 [ 36.839537] ? graph_lock+0x170/0x170 [ 36.840290] ? check_usage+0xb70/0xb70 [ 36.841043] ? find_held_lock+0x39/0x1d0 [ 36.841608] ? hlock_class+0x140/0x140 [ 36.842173] ? lock_downgrade+0x990/0x990 [ 36.842882] ? check_noncircular+0x20/0x20 [ 36.843724] lock_commit_crosslock+0xe73/0x1d10 [ 36.844610] ? lock_commit_crosslock+0xe73/0x1d10 [ 36.845302] ? check_noncircular+0x20/0x20 [ 36.845884] ? check_prev_add+0x1520/0x1520 [ 36.846693] ? lock_acquire+0x1d5/0x580 [ 36.847410] ? complete+0x18/0x80 [ 36.848073] ? lock_release+0xd70/0xd70 [ 36.848735] ? check_noncircular+0x20/0x20 [ 36.849324] ? do_raw_spin_trylock+0x190/0x190 [ 36.850238] complete+0x24/0x80 [ 36.850873] wakeme_after_rcu+0xd/0x10 [ 36.851601] srcu_invoke_callbacks+0x280/0x4d0 [ 36.852270] ? srcu_queue_delayed_work_on+0x240/0x240 [ 36.852996] ? __lock_is_held+0xbc/0x140 [ 36.853716] process_one_work+0xbfd/0x1be0 [ 36.855322] ? check_noncircular+0x20/0x20 [ 36.855694] ? pwq_dec_nr_in_flight+0x450/0x450 [ 36.856113] ? finish_task_switch+0x1d3/0x740 [ 36.856508] ? __sched_text_start+0x8/0x8 [ 36.856867] ? check_noncircular+0x20/0x20 [ 36.857247] ? retint_kernel+0x10/0x10 [ 36.857602] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.858043] ? find_held_lock+0x39/0x1d0 [ 36.858411] ? lock_acquire+0x1d5/0x580 [ 36.858786] ? worker_thread+0x4a3/0x1860 [ 36.859186] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 36.859651] ? lock_release+0xd70/0xd70 [ 36.860005] ? do_raw_spin_trylock+0x190/0x190 [ 36.860418] ? retint_kernel+0x10/0x10 [ 36.860789] worker_thread+0x223/0x1860 [ 36.861184] ? process_one_work+0x1be0/0x1be0 [ 36.861838] ? check_noncircular+0x20/0x20 [ 36.862618] ? _raw_spin_unlock_irq+0x27/0x70 [ 36.863447] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.864373] ? trace_hardirqs_on+0xd/0x10 [ 36.865026] ? _raw_spin_unlock_irq+0x27/0x70 [ 36.865683] ? finish_task_switch+0x1d3/0x740 [ 36.866507] ? finish_task_switch+0x1aa/0x740 [ 36.867204] ? preempt_notifier_dec+0x20/0x20 [ 36.867985] ? __schedule+0x8f0/0x2070 [ 36.868662] ? __x2apic_send_IPI_dest.constprop.7+0x5b/0x80 [ 36.869580] ? try_to_wake_up+0xf9/0x1600 [ 36.870332] ? lock_commit_crosslock+0xe73/0x1d10 [ 36.870997] ? find_held_lock+0x39/0x1d0 [ 36.871747] ? lock_downgrade+0x990/0x990 [ 36.872422] ? complete+0x18/0x80 [ 36.872877] ? __schedule+0x2070/0x2070 [ 36.873542] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 36.874399] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.876660] ? trace_hardirqs_on+0xd/0x10 [ 36.877411] ? __kthread_parkme+0x173/0x240 [ 36.878104] kthread+0x39c/0x470 [ 36.878705] ? process_one_work+0x1be0/0x1be0 [ 36.879346] ? kthread_create_on_node+0x100/0x100 [ 36.880160] ret_from_fork+0x2a/0x40