[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.201801] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.877476] random: sshd: uninitialized urandom read (32 bytes read) [ 24.192793] random: sshd: uninitialized urandom read (32 bytes read) [ 24.949825] random: sshd: uninitialized urandom read (32 bytes read) [ 37.362836] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.31' (ECDSA) to the list of known hosts. [ 42.782772] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 43.211428] [ 43.213076] ===================================== [ 43.217887] WARNING: bad unlock balance detected! [ 43.222699] 4.17.0-rc5+ #58 Not tainted [ 43.226642] ------------------------------------- [ 43.231454] kworker/u4:0/6 is trying to release lock (&file->mut) at: [ 43.238016] [] ucma_event_handler+0x780/0xff0 [ 43.244041] but there are no more locks to release! [ 43.249026] [ 43.249026] other info that might help us debug this: [ 43.255668] 4 locks held by kworker/u4:0/6: [ 43.259958] #0: (ptrval) ((wq_completion)"ib_addr"){+.+.}, at: process_one_work+0xaef/0x1b50 [ 43.269302] #1: (ptrval) ((work_completion)(&(&req->work)->work)){+.+.}, at: process_one_work+0xb46/0x1b50 [ 43.279861] #2: (ptrval) (&id_priv->handler_mutex){+.+.}, at: addr_handler+0xa6/0x3d0 [ 43.288593] #3: (ptrval) (&file->mut){+.+.}, at: ucma_event_handler+0x10e/0xff0 [ 43.296804] [ 43.296804] stack backtrace: [ 43.301275] CPU: 1 PID: 6 Comm: kworker/u4:0 Not tainted 4.17.0-rc5+ #58 [ 43.308082] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.317416] Workqueue: ib_addr process_one_req [ 43.321968] Call Trace: [ 43.324533] dump_stack+0x1b9/0x294 [ 43.328136] ? dump_stack_print_info.cold.2+0x52/0x52 [ 43.333301] ? print_lock+0xd1/0xd6 [ 43.336903] ? vprintk_func+0x81/0xe7 [ 43.340678] ? ucma_event_handler+0x780/0xff0 [ 43.345148] print_unlock_imbalance_bug.cold.50+0xcc/0xd8 [ 43.350658] lock_release+0x77a/0xa10 [ 43.354433] ? ucma_event_handler+0x780/0xff0 [ 43.358900] ? lock_downgrade+0x8e0/0x8e0 [ 43.363023] ? lock_downgrade+0x8e0/0x8e0 [ 43.367147] ? mark_held_locks+0xc9/0x160 [ 43.371270] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 43.375827] __mutex_unlock_slowpath+0xeb/0x8a0 [ 43.380470] ? wait_for_completion+0x870/0x870 [ 43.385028] ? __wake_up_common_lock+0x1c2/0x300 [ 43.389756] ? __wake_up_common+0x730/0x730 [ 43.394053] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 43.399562] ? ib_copy_ah_attr_to_user+0x539/0x930 [ 43.404467] mutex_unlock+0xd/0x10 [ 43.407981] ucma_event_handler+0x780/0xff0 [ 43.412279] ? _raw_read_unlock_irqrestore+0x61/0xc0 [ 43.417358] ? ucma_destroy_id+0x540/0x540 [ 43.421566] ? cma_comp_exch+0xab/0xd0 [ 43.425427] addr_handler+0x2bd/0x3d0 [ 43.429206] ? cma_work_handler+0x1f0/0x1f0 [ 43.433500] ? graph_lock+0x170/0x170 [ 43.437276] ? cma_work_handler+0x1f0/0x1f0 [ 43.441572] process_one_req+0x2e8/0x750 [ 43.445608] ? addr_resolve+0xc20/0xc20 [ 43.449558] ? __lock_is_held+0xb5/0x140 [ 43.453603] process_one_work+0xc1e/0x1b50 [ 43.457814] ? finish_task_switch+0x182/0x840 [ 43.462284] ? pwq_dec_nr_in_flight+0x490/0x490 [ 43.466926] ? __schedule+0x809/0x1e30 [ 43.470786] ? retint_kernel+0x10/0x10 [ 43.474646] ? graph_lock+0x170/0x170 [ 43.478420] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.483410] ? retint_kernel+0x10/0x10 [ 43.487269] ? find_held_lock+0x36/0x1c0 [ 43.491303] ? lock_acquire+0x1dc/0x520 [ 43.495566] ? worker_thread+0x41f/0x1440 [ 43.499688] ? lock_downgrade+0x8e0/0x8e0 [ 43.503810] ? lock_release+0xa10/0xa10 [ 43.507761] ? kasan_check_read+0x11/0x20 [ 43.511882] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 43.516441] worker_thread+0x1cc/0x1440 [ 43.520390] ? process_one_work+0x1b50/0x1b50 [ 43.524867] ? graph_lock+0x170/0x170 [ 43.528640] ? find_held_lock+0x36/0x1c0 [ 43.532676] ? find_held_lock+0x36/0x1c0 [ 43.536717] ? __schedule+0x1e30/0x1e30 [ 43.540668] ? do_raw_spin_unlock+0x9e/0x2e0 [ 43.545051] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 43.549614] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 43.555125] ? __kthread_parkme+0x111/0x1d0 executing program executing program executing program [ 43.559428] ? parse_args.cold.15+0x1b3/0x1b3 [ 43.563896] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.568888] ? trace_hardirqs_on+0xd/0x10 [ 43.573010] kthread+0x345/0x410 [ 43.576352] ? process_one_work+0x1b50/0x1b50 [ 43.580820] ? kthread_bind+0x40/0x40 [ 43.584602] ret_from_fork+0x3a/0x50