[[0;32m OK [0m] Started getty on tty2-tty6 if dbus and logind are not available.
[[0;32m OK [0m] Started OpenBSD Secure Shell server.
[[0;32m OK [0m] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch.
[[0;32m OK [0m] Reached target Login Prompts.
[[0;32m OK [0m] Reached target Multi-User System.
[[0;32m OK [0m] Reached target Graphical Interface.
Starting Update UTMP about System Runlevel Changes...
Starting Load/Save RF Kill Switch Status...
[[0;32m OK [0m] Started Update UTMP about System Runlevel Changes.
[[0;32m OK [0m] Started Load/Save RF Kill Switch Status.
Debian GNU/Linux 9 syzkaller ttyS0
Warning: Permanently added '10.128.0.216' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [ 27.418623]
[ 27.420271] ======================================================
[ 27.426562] WARNING: possible circular locking dependency detected
[ 27.432864] 4.14.294-syzkaller #0 Not tainted
[ 27.437332] ------------------------------------------------------
[ 27.443639] syz-executor424/7961 is trying to acquire lock:
[ 27.449755] (event_mutex){+.+.}, at: [<ffffffff815b1463>] perf_trace_destroy+0x23/0xf0
[ 27.457883]
[ 27.457883] but task is already holding lock:
[ 27.463831] (&event->child_mutex){+.+.}, at: [<ffffffff81659408>] perf_event_release_kernel+0x208/0x8a0
[ 27.473436]
[ 27.473436] which lock already depends on the new lock.
[ 27.473436]
[ 27.481730]
[ 27.481730] the existing dependency chain (in reverse order) is:
[ 27.489327]
[ 27.489327] -> #5 (&event->child_mutex){+.+.}:
[ 27.495464] __mutex_lock+0xc4/0x1310
[ 27.499763] perf_event_for_each_child+0x82/0x140
[ 27.505198] _perf_ioctl+0x3db/0x1a60
[ 27.509531] perf_ioctl+0x55/0x80
[ 27.513480] do_vfs_ioctl+0x75a/0xff0
[ 27.517773] SyS_ioctl+0x7f/0xb0
[ 27.521636] do_syscall_64+0x1d5/0x640
[ 27.526022] entry_SYSCALL_64_after_hwframe+0x46/0xbb
[ 27.531706]
[ 27.531706] -> #4 (&cpuctx_mutex){+.+.}:
[ 27.537226] __mutex_lock+0xc4/0x1310
[ 27.541528] perf_event_init_cpu+0xb7/0x170
[ 27.546348] perf_event_init+0x2cc/0x308
[ 27.550903] start_kernel+0x45d/0x763
[ 27.555199] secondary_startup_64+0xa5/0xb0
[ 27.560013]
[ 27.560013] -> #3 (pmus_lock){+.+.}:
[ 27.565189] __mutex_lock+0xc4/0x1310
[ 27.569542] perf_event_init_cpu+0x2c/0x170
[ 27.574360] cpuhp_invoke_callback+0x1e6/0x1a80
[ 27.579535] _cpu_up+0x21e/0x520
[ 27.583396] do_cpu_up+0x9a/0x160
[ 27.587345] smp_init+0x197/0x1ac
[ 27.591357] kernel_init_freeable+0x406/0x626
[ 27.596368] kernel_init+0xd/0x16a
[ 27.600401] ret_from_fork+0x24/0x30
[ 27.604605]
[ 27.604605] -> #2 (cpu_hotplug_lock.rw_sem){++++}:
[ 27.611064] cpus_read_lock+0x39/0xc0
[ 27.615557] static_key_slow_inc+0xe/0x20
[ 27.620206] tracepoint_add_func+0x747/0xa40
[ 27.625127] tracepoint_probe_register+0x8c/0xc0
[ 27.630392] trace_event_reg+0x272/0x330
[ 27.634956] perf_trace_init+0x424/0xa30
[ 27.639523] perf_tp_event_init+0x79/0xf0
[ 27.644177] perf_try_init_event+0x15b/0x1f0
[ 27.649088] perf_event_alloc.part.0+0xe2d/0x2640
[ 27.654441] SyS_perf_event_open+0x683/0x2530
[ 27.659446] do_syscall_64+0x1d5/0x640
[ 27.663833] entry_SYSCALL_64_after_hwframe+0x46/0xbb
[ 27.669513]
[ 27.669513] -> #1 (tracepoints_mutex){+.+.}:
[ 27.675384] __mutex_lock+0xc4/0x1310
[ 27.679682] tracepoint_probe_register+0x68/0xc0
[ 27.684933] trace_event_reg+0x272/0x330
[ 27.689592] perf_trace_init+0x424/0xa30
[ 27.694152] perf_tp_event_init+0x79/0xf0
[ 27.698808] perf_try_init_event+0x15b/0x1f0
[ 27.703748] perf_event_alloc.part.0+0xe2d/0x2640
[ 27.709091] SyS_perf_event_open+0x683/0x2530
[ 27.714088] do_syscall_64+0x1d5/0x640
[ 27.718565] entry_SYSCALL_64_after_hwframe+0x46/0xbb
[ 27.724249]
[ 27.724249] -> #0 (event_mutex){+.+.}:
[ 27.729601] lock_acquire+0x170/0x3f0
[ 27.733909] __mutex_lock+0xc4/0x1310
[ 27.738227] perf_trace_destroy+0x23/0xf0
[ 27.742874] _free_event+0x321/0xe20
[ 27.747080] free_event+0x32/0x40
[ 27.751027] perf_event_release_kernel+0x368/0x8a0
[ 27.756451] perf_release+0x33/0x40
[ 27.760572] __fput+0x25f/0x7a0
[ 27.764352] task_work_run+0x11f/0x190
[ 27.768735] do_exit+0xa44/0x2850
[ 27.772686] SyS_exit+0x1e/0x20
[ 27.776459] do_syscall_64+0x1d5/0x640
[ 27.780841] entry_SYSCALL_64_after_hwframe+0x46/0xbb
[ 27.786522]
[ 27.786522] other info that might help us debug this:
[ 27.786522]
[ 27.794637] Chain exists of:
[ 27.794637] event_mutex --> &cpuctx_mutex --> &event->child_mutex
[ 27.794637]
[ 27.805367] Possible unsafe locking scenario:
[ 27.805367]
[ 27.811397] CPU0 CPU1
[ 27.816044] ---- ----
[ 27.820681] lock(&event->child_mutex);
[ 27.824722] lock(&cpuctx_mutex);
[ 27.830764] lock(&event->child_mutex);
[ 27.837315] lock(event_mutex);
[ 27.840653]
[ 27.840653] *** DEADLOCK ***
[ 27.840653]
[ 27.846686] 2 locks held by syz-executor424/7961:
[ 27.851498] #0: (&ctx->mutex){+.+.}, at: [<ffffffff816593fe>] perf_event_release_kernel+0x1fe/0x8a0
[ 27.860847] #1: (&event->child_mutex){+.+.}, at: [<ffffffff81659408>] perf_event_release_kernel+0x208/0x8a0
[ 27.870880]
[ 27.870880] stack backtrace:
[ 27.875351] CPU: 0 PID: 7961 Comm: syz-executor424 Not tainted 4.14.294-syzkaller #0
[ 27.883203] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2022
[ 27.892551] Call Trace:
[ 27.895223] dump_stack+0x1b2/0x281
[ 27.898830] print_circular_bug.constprop.0.cold+0x2d7/0x41e
[ 27.904608] __lock_acquire+0x2e0e/0x3f20
[ 27.908733] ? trace_hardirqs_on+0x10/0x10
[ 27.912944] ? perf_group_detach+0x7f0/0x7f0
[ 27.917415] ? generic_exec_single+0x27e/0x420
[ 27.921972] ? smp_call_function_single+0x1b1/0x370
[ 27.926964] lock_acquire+0x170/0x3f0
[ 27.930741] ? perf_trace_destroy+0x23/0xf0
[ 27.935060] ? perf_trace_destroy+0x23/0xf0
[ 27.939444] __mutex_lock+0xc4/0x1310
[ 27.943219] ? perf_trace_destroy+0x23/0xf0
[ 27.947515] ? task_function_call+0xed/0x130
[ 27.951897] ? pmu_dev_release+0x20/0x20
[ 27.955934] ? perf_trace_destroy+0x23/0xf0
[ 27.960233] ? __ww_mutex_wakeup_for_backoff+0x210/0x210
[ 27.965743] ? event_function_call+0x1fa/0x3c0
[ 27.970305] ? event_sched_out+0x11b0/0x11b0
[ 27.974691] ? rcu_lockdep_current_cpu_online+0xed/0x140
[ 27.980123] ? perf_tp_event_init+0xf0/0xf0
[ 27.984424] perf_trace_destroy+0x23/0xf0
[ 27.988545] ? perf_tp_event_init+0xf0/0xf0
[ 27.992930] _free_event+0x321/0xe20
[ 27.996643] free_event+0x32/0x40
[ 28.000070] perf_event_release_kernel+0x368/0x8a0
[ 28.004987] ? perf_event_release_kernel+0x8a0/0x8a0
[ 28.010085] perf_release+0x33/0x40
[ 28.013691] __fput+0x25f/0x7a0
[ 28.017037] task_work_run+0x11f/0x190
[ 28.020918] do_exit+0xa44/0x2850
[ 28.024349] ? get_timespec64+0xb1/0xf0
[ 28.028315] ? timespec_trunc+0x120/0x120
[ 28.032439] ? mm_update_next_owner+0x5b0/0x5b0
[ 28.037087] ? SyS_clock_nanosleep+0x210/0x2d0
[ 28.041641] ? compat_SyS_clock_getres+0x180/0x180
[ 28.046700] ? __do_page_fault+0x159/0xad0
[ 28.050926] SyS_exit+0x1e/0x20
[ 28.054182] ? complete_and_exit+0x40/0x40
[ 28.058393] do_syscall_64+0x1d5/0x640
[ 28.062256] entry_SYSCALL_64_after_hwframe+0x46/0xbb
[ 28.067420] RIP: 0033:0x7f2b75a992a9
[