2017/08/23 20:43:55 parsed 1 programs 2017/08/23 20:43:55 executed programs: 0 syzkaller login: [ 29.732083] [ 29.732236] ====================================================== [ 29.732689] WARNING: possible circular locking dependency detected [ 29.733221] 4.13.0-rc6-next-20170823+ #7 Not tainted [ 29.733654] ------------------------------------------------------ [ 29.734166] kworker/0:3/1308 is trying to acquire lock: [ 29.734600] ((shepherd).work){+.+.}, at: [] process_one_work+0xb2c/0x1be0 [ 29.735299] [ 29.735299] but now in release context of a crosslock acquired at the following: [ 29.735941] ((complete)&rcu.completion){+.+.}, at: [] __synchronize_srcu+0x1b5/0x250 [ 29.737061] [ 29.737061] which lock already depends on the new lock. [ 29.737061] [ 29.738228] [ 29.738228] the existing dependency chain (in reverse order) is: [ 29.739280] [ 29.739280] -> #2 ((complete)&rcu.completion){+.+.}: [ 29.740211] __lock_acquire+0x3286/0x4620 [ 29.740857] lock_acquire+0x1d5/0x580 [ 29.741464] wait_for_completion+0xc8/0x770 [ 29.742140] __synchronize_srcu+0x1b5/0x250 [ 29.744272] synchronize_srcu+0x1a3/0x560 [ 29.745046] quarantine_remove_cache+0xd7/0xf0 [ 29.745751] kasan_cache_shrink+0x9/0x10 [ 29.746406] kmem_cache_shrink+0x15/0x30 [ 29.747060] acpi_os_purge_cache+0x15/0x20 [ 29.747725] acpi_purge_cached_objects+0x38/0xc9 [ 29.748502] acpi_initialize_objects+0xc5/0x112 [ 29.750189] acpi_init+0x23c/0x8e6 [ 29.750746] do_one_initcall+0x9e/0x330 [ 29.752397] kernel_init_freeable+0x46e/0x526 [ 29.753127] kernel_init+0x13/0x172 [ 29.753979] ret_from_fork+0x2a/0x40 [ 29.755277] [ 29.755277] -> #1 (cpu_hotplug_lock.rw_sem){++++}: [ 29.757258] __lock_acquire+0x3286/0x4620 [ 29.757885] lock_acquire+0x1d5/0x580 [ 29.759156] cpus_read_lock+0x42/0x90 [ 29.759855] vmstat_shepherd+0x3d/0x1b0 [ 29.761521] process_one_work+0xbfd/0x1be0 [ 29.762194] worker_thread+0x223/0x1860 [ 29.763360] kthread+0x39c/0x470 [ 29.764300] ret_from_fork+0x2a/0x40 [ 29.766270] [ 29.766270] -> #0 ((shepherd).work){+.+.}: [ 29.767110] process_one_work+0xba5/0x1be0 [ 29.768464] worker_thread+0x223/0x1860 [ 29.770202] kthread+0x39c/0x470 [ 29.770727] ret_from_fork+0x2a/0x40 [ 29.771341] 0xffffffffffffffff [ 29.772421] [ 29.772421] other info that might help us debug this: [ 29.772421] [ 29.775104] Chain exists of: [ 29.775104] (shepherd).work --> cpu_hotplug_lock.rw_sem --> (complete)&rcu.completion [ 29.775104] [ 29.777320] Possible unsafe locking scenario by crosslock: [ 29.777320] [ 29.779165] CPU0 CPU1 [ 29.779793] ---- ---- [ 29.781362] lock(cpu_hotplug_lock.rw_sem); [ 29.781973] lock((complete)&rcu.completion); [ 29.783919] lock((shepherd).work); [ 29.786785] unlock((complete)&rcu.completion); [ 29.788183] [ 29.788183] *** DEADLOCK *** [ 29.788183] [ 29.789628] 3 locks held by kworker/0:3/1308: [ 29.791435] #0: ("events_power_efficient"){.+.+}, at: [] process_one_work+0xad4/0x1be0 [ 29.793515] #1: ((&(&sdp->work)->work)){+.+.}, at: [] process_one_work+0xb2c/0x1be0 [ 29.795863] #2: (&x->wait#5){....}, at: [] complete+0x18/0x80 [ 29.797477] [ 29.797477] stack backtrace: [ 29.798350] CPU: 0 PID: 1308 Comm: kworker/0:3 Not tainted 4.13.0-rc6-next-20170823+ #7 [ 29.800436] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 29.802423] Workqueue: events_power_efficient srcu_invoke_callbacks [ 29.804230] Call Trace: [ 29.804595] dump_stack+0x194/0x257 [ 29.806111] ? arch_local_irq_restore+0x53/0x53 [ 29.808706] print_circular_bug+0x503/0x710 [ 29.809398] ? print_circular_bug_entry+0xb0/0xb0 [ 29.810172] check_prev_add+0x865/0x1520 [ 29.810816] ? graph_lock+0x170/0x170 [ 29.811420] ? check_usage+0xb70/0xb70 [ 29.812288] ? hlock_class+0x140/0x140 [ 29.814042] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 29.814853] lock_commit_crosslock+0xe73/0x1d10 [ 29.816465] ? lock_commit_crosslock+0xe73/0x1d10 [ 29.817225] ? check_prev_add+0x1520/0x1520 [ 29.818574] ? lock_acquire+0x1d5/0x580 [ 29.820173] ? complete+0x18/0x80 [ 29.820637] ? lock_release+0xd70/0xd70 [ 29.821240] ? do_raw_spin_trylock+0x190/0x190 [ 29.822535] complete+0x24/0x80 [ 29.823160] wakeme_after_rcu+0xd/0x10 [ 29.824599] srcu_invoke_callbacks+0x280/0x4d0 [ 29.826067] ? srcu_queue_delayed_work_on+0x240/0x240 [ 29.826792] ? __lock_is_held+0xbc/0x140 [ 29.828266] process_one_work+0xbfd/0x1be0 [ 29.828910] ? check_noncircular+0x20/0x20 [ 29.830300] ? pwq_dec_nr_in_flight+0x450/0x450 [ 29.831394] ? finish_task_switch+0x1d3/0x740 [ 29.832380] ? finish_task_switch+0x1aa/0x740 [ 29.833497] ? __sched_text_start+0x8/0x8 [ 29.834405] ? unwind_dump+0x4c0/0x4c0 [ 29.835556] ? check_noncircular+0x20/0x20 [ 29.837134] ? __unwind_start+0x169/0x330 [ 29.837733] ? find_held_lock+0x39/0x1d0 [ 29.839211] ? lock_acquire+0x1d5/0x580 [ 29.839810] ? worker_thread+0x4a3/0x1860 [ 29.840980] ? lock_release+0xd70/0xd70 [ 29.841483] ? do_raw_spin_trylock+0x190/0x190 [ 29.841909] ? find_held_lock+0x39/0x1d0 [ 29.843430] worker_thread+0x223/0x1860 [ 29.843833] ? process_one_work+0x1be0/0x1be0 [ 29.844832] ? check_noncircular+0x20/0x20 [ 29.845897] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.847082] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 29.847988] ? trace_hardirqs_on+0xd/0x10 [ 29.849976] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.850429] ? finish_task_switch+0x1d3/0x740 [ 29.852055] ? finish_task_switch+0x1aa/0x740 [ 29.852480] ? preempt_notifier_dec+0x20/0x20 [ 29.854097] ? __schedule+0x8f0/0x2070 [ 29.854461] ? try_to_wake_up+0xf9/0x1600 [ 29.854846] ? find_held_lock+0x39/0x1d0 [ 29.856378] ? lock_downgrade+0x990/0x990 [ 29.856764] ? kmem_cache_alloc_trace+0x492/0x750 [ 29.858353] ? complete+0x18/0x80 [ 29.858675] ? __schedule+0x2070/0x2070 [ 29.860148] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 29.860650] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 29.862199] ? trace_hardirqs_on+0xd/0x10 [ 29.862611] ? __kthread_parkme+0x173/0x240 [ 29.864037] kthread+0x39c/0x470 [ 29.864406] ? process_one_work+0x1be0/0x1be0 [ 29.865391] ? kthread_create_on_node+0x100/0x100 [ 29.865955] ret_from_fork+0x2a/0x40