[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.246' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 28.177868] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10) [ 28.192523] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x1) [ 28.212400] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x1) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.249581] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.320318] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.383645] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x1) [ 28.399823] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10) [ 28.422085] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x1) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.453035] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x1) [ 28.481789] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.516556] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x11) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.573429] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x1) [ 28.592942] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 28.624491] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10) [ 28.659575] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x10) executing program executing program executing program executing program executing program executing program executing program executing program [ 28.673035] Failed to enqueue queue_pair DETACH event datagram for context (ID=0x1) [ 28.695216] [ 28.696865] ============================================ [ 28.702300] WARNING: possible recursive locking detected [ 28.707722] 4.14.274-syzkaller #0 Not tainted [ 28.712186] -------------------------------------------- [ 28.717692] syz-executor275/8396 is trying to acquire lock: [ 28.723470] (qp_broker_list.mutex){+.+.}, at: [] vmci_qp_broker_detach+0x11b/0x1000 [ 28.732905] [ 28.732905] but task is already holding lock: [ 28.738878] (qp_broker_list.mutex){+.+.}, at: [] vmci_qp_broker_detach+0x11b/0x1000 [ 28.748306] [ 28.748306] other info that might help us debug this: [ 28.754944] Possible unsafe locking scenario: [ 28.754944] [ 28.761321] CPU0 [ 28.763876] ---- [ 28.766431] lock(qp_broker_list.mutex); [ 28.770551] lock(qp_broker_list.mutex); [ 28.774729] [ 28.774729] *** DEADLOCK *** [ 28.774729] [ 28.780756] May be due to missing lock nesting notation [ 28.780756] [ 28.787653] 1 lock held by syz-executor275/8396: [ 28.792388] #0: (qp_broker_list.mutex){+.+.}, at: [] vmci_qp_broker_detach+0x11b/0x1000 [ 28.802252] [ 28.802252] stack backtrace: [ 28.806731] CPU: 1 PID: 8396 Comm: syz-executor275 Not tainted 4.14.274-syzkaller #0 [ 28.814583] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.823908] Call Trace: [ 28.826473] dump_stack+0x1b2/0x281 [ 28.830078] __lock_acquire.cold+0x180/0x97c [ 28.834745] ? lock_downgrade+0x740/0x740 [ 28.838880] ? trace_hardirqs_on+0x10/0x10 [ 28.843093] ? depot_save_stack+0x1d3/0x3f0 [ 28.847389] ? lock_acquire+0x170/0x3f0 [ 28.851336] ? lock_downgrade+0x740/0x740 [ 28.855455] ? unwind_get_return_address+0x51/0x90 [ 28.860364] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 28.865439] ? check_preemption_disabled+0x35/0x240 [ 28.870432] lock_acquire+0x170/0x3f0 [ 28.874238] ? vmci_qp_broker_detach+0x11b/0x1000 [ 28.879066] ? vmci_qp_broker_detach+0x11b/0x1000 [ 28.883898] __mutex_lock+0xc4/0x1310 [ 28.887687] ? vmci_qp_broker_detach+0x11b/0x1000 [ 28.892499] ? vmci_host_close+0xf9/0x170 [ 28.896618] ? task_work_run+0x11f/0x190 [ 28.900665] ? do_exit+0xa44/0x2850 [ 28.904265] ? get_signal+0x38d/0x1ca0 [ 28.908124] ? do_signal+0x7c/0x1550 [ 28.911812] ? exit_to_usermode_loop+0x160/0x200 [ 28.916549] ? vmci_qp_broker_detach+0x11b/0x1000 [ 28.921367] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 28.926792] ? lock_downgrade+0x740/0x740 [ 28.930924] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 28.936013] ? debug_check_no_obj_freed+0x2c0/0x680 [ 28.941009] vmci_qp_broker_detach+0x11b/0x1000 [ 28.945678] ? mark_held_locks+0xa6/0xf0 [ 28.949712] ? vmci_qp_broker_set_page_store+0x650/0x650 [ 28.955132] ? vmci_ctx_put+0x428/0xbf0 [ 28.959099] ? trace_hardirqs_on_caller+0x3a8/0x580 [ 28.964093] vmci_ctx_put+0x487/0xbf0 [ 28.967875] ? vmci_ctx_unset_notify+0x250/0x250 [ 28.972607] ? ___preempt_schedule+0x16/0x18 [ 28.976994] ? preempt_schedule_common+0x45/0xc0 [ 28.981722] ? ___preempt_schedule+0x16/0x18 [ 28.986116] vmci_ctx_enqueue_datagram+0x3b1/0x4b0 [ 28.991024] vmci_datagram_dispatch+0x2b8/0x970 [ 28.995664] ? vmci_qp_broker_detach+0xd46/0x1000 [ 29.000478] ? vmci_datagram_destroy_handle+0x60/0x60 [ 29.005640] qp_notify_peer+0x13b/0x1e0 [ 29.009590] ? qp_host_unregister_user_memory+0x2c0/0x2c0 [ 29.015101] vmci_qp_broker_detach+0x8c2/0x1000 [ 29.019742] ? vmci_qp_broker_set_page_store+0x650/0x650 [ 29.025168] ? vmci_ctx_put+0x428/0xbf0 [ 29.029121] ? trace_hardirqs_on_caller+0x3a8/0x580 [ 29.034108] vmci_ctx_put+0x487/0xbf0 [ 29.037881] ? vmci_ctx_unset_notify+0x250/0x250 [ 29.042615] ? lock_acquire+0x170/0x3f0 [ 29.046572] ? lock_downgrade+0x740/0x740 [ 29.050695] ? __fsnotify_update_child_dentry_flags.part.0+0x2e0/0x2e0 [ 29.057344] ? do_raw_spin_unlock+0x164/0x220 [ 29.061809] ? _raw_spin_unlock+0x29/0x40 [ 29.065928] ? vmci_host_poll+0x200/0x200 [ 29.070056] vmci_host_close+0xf9/0x170 [ 29.074005] __fput+0x25f/0x7a0 [ 29.077265] task_work_run+0x11f/0x190 [ 29.081137] do_exit+0xa44/0x2850 [ 29.084565] ? wake_up_q+0x82/0xd0 [ 29.088095] ? mm_update_next_owner+0x5b0/0x5b0 [ 29.092744] ? get_signal+0x323/0x1ca0 [ 29.096626] ? lock_acquire+0x170/0x3f0 [ 29.100578] ? lock_downgrade+0x740/0x740 [ 29.104721] do_group_exit+0x100/0x2e0 [ 29.108586] get_signal+0x38d/0x1ca0 [ 29.112272] ? do_futex+0x127/0x1570 [ 29.115957] ? lock_acquire+0x170/0x3f0 [ 29.119905] ? lock_downgrade+0x740/0x740 [ 29.124028] do_signal+0x7c/0x1550 [ 29.127542] ? trace_hardirqs_on+0x10/0x10 [ 29.131751] ? debug_check_no_obj_freed+0x2c0/0x680 [ 29.136749] ? setup_sigcontext+0x820/0x820 [ 29.141055] ? vmci_host_do_alloc_queuepair.constprop.0+0x350/0x350 [ 29.147439] ? expand_files+0x3cf/0x740 [ 29.151408] ? SyS_dup3+0x2b1/0x360 [ 29.155067] ? SyS_futex+0x1da/0x290 [ 29.158764] ? SyS_futex+0x1e3/0x290 [ 29.162454] ? exit_to_usermode_loop+0x41/0x200 [ 29.167098] exit_to_usermode_loop+0x160/0x200 [ 29.171655] do_syscall_64+0x4a3/0x640 [ 29.175543] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.180720] RIP: 0033:0x7f605595da09 [ 29.184404] RSP: 002b:00007f605590f308 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 29.192084] RAX: 0000000000000001 RBX: 00007f60559e53e8 RCX: 00007f605595da09 [ 29.199331] RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f60559e53ec [ 29.206574] RBP: 00007f60559e53e0 R08: 0000000000000000 R09: 0000000000000000 [ 29.213818] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f60559e53ec executing program executing program [ 29.221148] R13: 00007f60559b3074 R14: 636d762f7665642f R15: 0000000000022000