Warning: Permanently added '10.128.10.50' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   46.997950] 
[   46.999820] ======================================================
[   47.006110] WARNING: possible circular locking dependency detected
[   47.012399] 4.20.0-rc2+ #241 Not tainted
[   47.016430] ------------------------------------------------------
[   47.022723] kworker/0:1/12 is trying to acquire lock:
[   47.027887] 00000000d920550f (&mdev->req_queue_mutex){+.+.}, at: v4l2_release+0x1d7/0x3a0
[   47.036188] 
[   47.036188] but task is already holding lock:
[   47.042132] 00000000fb5902c5 ((delayed_fput_work).work){+.+.}, at: process_one_work+0xb9a/0x1c40
[   47.051033] 
[   47.051033] which lock already depends on the new lock.
[   47.051033] 
[   47.059321] 
[   47.059321] the existing dependency chain (in reverse order) is:
[   47.066925] 
[   47.066925] -> #3 ((delayed_fput_work).work){+.+.}:
[   47.073397]        process_one_work+0xc0a/0x1c40
[   47.078130]        worker_thread+0x17f/0x1390
[   47.082608]        kthread+0x35a/0x440
[   47.086478]        ret_from_fork+0x3a/0x50
[   47.090685] 
[   47.090685] -> #2 ((wq_completion)"events"){+.+.}:
[   47.097074]        flush_workqueue+0x30a/0x1e10
[   47.101716]        vim2m_stop_streaming+0x7c/0x2c0
[   47.106620]        __vb2_queue_cancel+0x171/0xd20
[   47.111450]        vb2_core_queue_release+0x26/0x80
[   47.116459]        vb2_queue_release+0x15/0x20
[   47.121016]        v4l2_m2m_ctx_release+0x1e/0x35
[   47.125832]        vim2m_release+0xe6/0x150
[   47.130126]        v4l2_release+0x224/0x3a0
[   47.134433]        __fput+0x385/0xa30
[   47.138207]        ____fput+0x15/0x20
[   47.141982]        task_work_run+0x1e8/0x2a0
[   47.146383]        exit_to_usermode_loop+0x318/0x380
[   47.151469]        do_fast_syscall_32+0xcd5/0xfb2
[   47.156316]        entry_SYSENTER_compat+0x70/0x7f
[   47.161218] 
[   47.161218] -> #1 (&dev->dev_mutex){+.+.}:
[   47.166912]        __mutex_lock+0x166/0x16f0
[   47.171306]        mutex_lock_nested+0x16/0x20
[   47.175952]        vim2m_release+0xbc/0x150
[   47.180263]        v4l2_release+0x224/0x3a0
[   47.184561]        __fput+0x385/0xa30
[   47.188439]        ____fput+0x15/0x20
[   47.192216]        task_work_run+0x1e8/0x2a0
[   47.196597]        exit_to_usermode_loop+0x318/0x380
[   47.201683]        do_syscall_64+0x6be/0x820
[   47.206072]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   47.211892] 
[   47.211892] -> #0 (&mdev->req_queue_mutex){+.+.}:
[   47.218467]        lock_acquire+0x1ed/0x520
[   47.222927]        __mutex_lock+0x166/0x16f0
[   47.227343]        mutex_lock_nested+0x16/0x20
[   47.231920]        v4l2_release+0x1d7/0x3a0
[   47.236219]        __fput+0x385/0xa30
[   47.240007]        delayed_fput+0x55/0x80
[   47.244147]        process_one_work+0xc90/0x1c40
[   47.248894]        worker_thread+0x17f/0x1390
[   47.253367]        kthread+0x35a/0x440
[   47.257229]        ret_from_fork+0x3a/0x50
[   47.261433] 
[   47.261433] other info that might help us debug this:
[   47.261433] 
[   47.269567] Chain exists of:
[   47.269567]   &mdev->req_queue_mutex --> (wq_completion)"events" --> (delayed_fput_work).work
[   47.269567] 
[   47.282555]  Possible unsafe locking scenario:
[   47.282555] 
[   47.288586]        CPU0                    CPU1
[   47.293228]        ----                    ----
[   47.297879]   lock((delayed_fput_work).work);
[   47.302355]                                lock((wq_completion)"events");
[   47.309252]                                lock((delayed_fput_work).work);
[   47.316238]   lock(&mdev->req_queue_mutex);
[   47.320545] 
[   47.320545]  *** DEADLOCK ***
[   47.320545] 
[   47.326583] 2 locks held by kworker/0:1/12:
[   47.330885]  #0: 0000000045ac8ce7 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40
[   47.340142]  #1: 00000000fb5902c5 ((delayed_fput_work).work){+.+.}, at: process_one_work+0xb9a/0x1c40
[   47.349486] 
[   47.349486] stack backtrace:
[   47.353965] CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 4.20.0-rc2+ #241
[   47.360864] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   47.370293] Workqueue: events delayed_fput
[   47.374506] Call Trace:
[   47.377161]  dump_stack+0x244/0x39d
[   47.380771]  ? dump_stack_print_info.cold.1+0x20/0x20
[   47.386046]  ? vprintk_func+0x85/0x181
[   47.390036]  print_circular_bug.isra.35.cold.54+0x1bd/0x27d
[   47.395727]  ? save_trace+0xe0/0x290
[   47.399422]  __lock_acquire+0x3399/0x4c20
[   47.403553]  ? mark_held_locks+0x130/0x130
[   47.407770]  ? __update_load_avg_blocked_se+0x690/0x690
[   47.413115]  ? __update_load_avg_se+0xae0/0xae0
[   47.417761]  ? print_usage_bug+0xc0/0xc0
[   47.421801]  ? lock_unpin_lock+0x4a0/0x4a0
[   47.426014]  ? update_load_avg+0x387/0x2470
[   47.430456]  ? find_held_lock+0x36/0x1c0
[   47.434504]  ? zap_class+0x640/0x640
[   47.438196]  ? __lock_acquire+0x62f/0x4c20
[   47.442412]  ? zap_class+0x640/0x640
[   47.446119]  ? mark_held_locks+0x130/0x130
[   47.450344]  ? add_timer+0x629/0x15a0
[   47.454133]  lock_acquire+0x1ed/0x520
[   47.457917]  ? v4l2_release+0x1d7/0x3a0
[   47.461872]  ? lock_release+0xa00/0xa00
[   47.465831]  ? perf_trace_sched_process_exec+0x860/0x860
[   47.471264]  ? print_usage_bug+0xc0/0xc0
[   47.475306]  ? v4l2_release+0x1d7/0x3a0
[   47.479262]  __mutex_lock+0x166/0x16f0
[   47.483133]  ? v4l2_release+0x1d7/0x3a0
[   47.487088]  ? v4l2_release+0x1d7/0x3a0
[   47.491050]  ? mutex_trylock+0x2b0/0x2b0
[   47.495090]  ? __lock_acquire+0x62f/0x4c20
[   47.499319]  ? mark_held_locks+0x130/0x130
[   47.503539]  ? mark_held_locks+0x130/0x130
[   47.507754]  ? mark_held_locks+0x130/0x130
[   47.511967]  ? lock_downgrade+0x900/0x900
[   47.516110]  ? check_preemption_disabled+0x48/0x280
[   47.521109]  ? zap_class+0x640/0x640
[   47.524804]  ? trace_event_raw_event_lock+0x340/0x340
[   47.530125]  ? zap_class+0x640/0x640
[   47.533836]  ? zap_class+0x640/0x640
[   47.537536]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   47.543058]  ? fsnotify+0x50e/0xef0
[   47.546667]  ? __lock_is_held+0xb5/0x140
[   47.550708]  ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[   47.556223]  ? locks_remove_file+0x3c6/0x5c0
[   47.560617]  ? __sanitizer_cov_trace_const_cmp2+0x18/0x20
[   47.566150]  ? ima_file_free+0x132/0x650
[   47.570192]  ? fsnotify_first_mark+0x350/0x350
[   47.574756]  ? ima_file_check+0x130/0x130
[   47.578898]  ? vivid_remove+0x460/0x460
[   47.582853]  mutex_lock_nested+0x16/0x20
[   47.586892]  ? mutex_lock_nested+0x16/0x20
[   47.591104]  v4l2_release+0x1d7/0x3a0
[   47.594883]  ? dev_debug_store+0x140/0x140
[   47.599104]  __fput+0x385/0xa30
[   47.602364]  ? get_max_files+0x20/0x20
[   47.606406]  delayed_fput+0x55/0x80
[   47.610024]  process_one_work+0xc90/0x1c40
[   47.614245]  ? mark_held_locks+0x130/0x130
[   47.618465]  ? pwq_dec_nr_in_flight+0x4a0/0x4a0
[   47.623207]  ? __switch_to_asm+0x40/0x70
[   47.627263]  ? __switch_to_asm+0x34/0x70
[   47.631304]  ? __switch_to_asm+0x34/0x70
[   47.635347]  ? __switch_to_asm+0x40/0x70
[   47.639386]  ? __switch_to_asm+0x34/0x70
[   47.643424]  ? __switch_to_asm+0x40/0x70
[   47.647599]  ? __switch_to_asm+0x34/0x70
[   47.651650]  ? __switch_to_asm+0x40/0x70
[   47.655693]  ? __schedule+0x8d7/0x21d0
[   47.659565]  ? lock_downgrade+0x900/0x900
[   47.663694]  ? zap_class+0x640/0x640
[   47.667394]  ? find_held_lock+0x36/0x1c0
[   47.671495]  ? lock_acquire+0x1ed/0x520
[   47.675459]  ? worker_thread+0x3e0/0x1390
[   47.679592]  ? kasan_check_read+0x11/0x20
[   47.683786]  ? do_raw_spin_lock+0x14f/0x350
[   47.688090]  ? kasan_check_read+0x11/0x20
[   47.692237]  ? rwlock_bug.part.2+0x90/0x90
[   47.696450]  ? trace_hardirqs_on+0x310/0x310
[   47.700843]  worker_thread+0x17f/0x1390
[   47.704794]  ? __switch_to_asm+0x34/0x70
[   47.708835]  ? process_one_work+0x1c40/0x1c40
[   47.713313]  ? __sched_text_start+0x8/0x8
[   47.717443]  ? __kthread_parkme+0xce/0x1a0
[   47.721657]  ? _raw_spin_unlock_irqrestore+0x82/0xd0
[   47.726786]  ? _raw_spin_unlock_irqrestore+0x82/0xd0
[   47.731882]  ? lockdep_hardirqs_on+0x3bb/0x5b0
[   47.736446]  ? trace_hardirqs_on+0xbd/0x310
[   47.740751]  ? kasan_check_read+0x11/0x20
[   47.744887]  ? __kthread_parkme+0xce/0x1a0
executing program
[   47.749244]  ? trace_hardirqs_off_caller+0x310/0x310
[   47.754343]  ? _raw_spin_unlock_irqrestore+0x6d/0xd0
[   47.759430]  ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[   47.764948]  ? __kthread_parkme+0xfb/0x1a0
[   47.769162]  ? process_one_work+0x1c40/0x1c40
[   47.773640]  kthread+0x35a/0x440
[   47.777083]  ? kthread_stop+0x900/0x900
[   47.781107]  ret_from_fork+0x3a/0x50
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