INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.394984] sshd (4497) used greatest stack depth: 16712 bytes left Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. [ 29.193760] IPVS: ftp: loaded support on port[0] = 21 [ 29.194846] IPVS: ftp: loaded support on port[0] = 21 [ 29.202269] IPVS: ftp: loaded support on port[0] = 21 [ 29.210201] IPVS: ftp: loaded support on port[0] = 21 [ 29.214096] IPVS: ftp: loaded support on port[0] = 21 [ 29.216233] IPVS: ftp: loaded support on port[0] = 21 [ 29.221767] IPVS: ftp: loaded support on port[0] = 21 [ 29.226160] IPVS: ftp: loaded support on port[0] = 21 executing program executing program [ 29.346539] IPVS: stopping backup sync thread 4529 ... executing program executing program executing program executing program executing program [ 29.384222] IPVS: stopping backup sync thread 4532 ... executing program executing program executing program executing program executing program executing program [ 29.411383] IPVS: stopping backup sync thread 4539 ... [ 29.422917] IPVS: stopping backup sync thread 4546 ... [ 29.431225] IPVS: stopping backup sync thread 4548 ... [ 29.444265] IPVS: stopping backup sync thread 4550 ... [ 29.446649] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 29.450321] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 29.460970] IPVS: stopping backup sync thread 4560 ... [ 29.467758] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 29.472767] [ 29.481177] IPVS: stopping backup sync thread 4564 ... [ 29.481954] ============================================ [ 29.481957] WARNING: possible recursive locking detected [ 29.481964] 4.17.0-rc1+ #9 Not tainted [ 29.481967] -------------------------------------------- [ 29.481973] syzkaller277218/4552 is trying to acquire lock: [ 29.481978] 00000000156eb503 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 29.482009] [ 29.482009] but task is already holding lock: [ 29.525905] 00000000156eb503 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 29.532741] [ 29.532741] other info that might help us debug this: [ 29.539389] Possible unsafe locking scenario: [ 29.539389] [ 29.545429] CPU0 [ 29.548008] ---- [ 29.550590] lock(rtnl_mutex); [ 29.553847] lock(rtnl_mutex); [ 29.557100] [ 29.557100] *** DEADLOCK *** [ 29.557100] [ 29.563135] May be due to missing lock nesting notation [ 29.563135] [ 29.570047] 2 locks held by syzkaller277218/4552: [ 29.574865] #0: 00000000156eb503 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 29.582153] #1: 00000000f3b60a69 (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 29.590809] [ 29.590809] stack backtrace: [ 29.595288] CPU: 1 PID: 4552 Comm: syzkaller277218 Not tainted 4.17.0-rc1+ #9 [ 29.602534] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.611870] Call Trace: [ 29.614446] dump_stack+0x1b9/0x294 [ 29.618054] ? dump_stack_print_info.cold.2+0x52/0x52 [ 29.623231] ? print_lock+0xd1/0xd6 [ 29.626837] ? vprintk_func+0x81/0xe7 [ 29.630623] __lock_acquire.cold.62+0x18c/0x55b [ 29.635281] ? debug_check_no_locks_freed+0x310/0x310 [ 29.640473] ? account_kernel_stack+0x2bd/0x410 [ 29.645128] ? trace_hardirqs_on+0xd/0x10 [ 29.649262] ? put_task_stack+0x188/0x2c0 [ 29.653398] ? __lock_acquire+0x7f5/0x5140 [ 29.657621] ? preempt_notifier_register+0x1e0/0x1e0 [ 29.662706] ? __schedule+0x809/0x1e30 [ 29.666582] ? graph_lock+0x170/0x170 [ 29.670369] ? kasan_check_read+0x11/0x20 [ 29.674498] ? graph_lock+0x170/0x170 [ 29.678278] ? graph_lock+0x170/0x170 [ 29.682057] lock_acquire+0x1dc/0x520 [ 29.685840] ? rtnl_lock+0x17/0x20 [ 29.689358] ? lock_release+0xa10/0xa10 [ 29.693318] ? check_same_owner+0x320/0x320 [ 29.697619] ? schedule+0xef/0x430 [ 29.701142] ? rcu_note_context_switch+0x710/0x710 [ 29.706051] ? __schedule+0x1e30/0x1e30 [ 29.710003] ? __might_sleep+0x95/0x190 [ 29.713963] ? rtnl_lock+0x17/0x20 [ 29.717483] __mutex_lock+0x16d/0x17f0 [ 29.721351] ? rtnl_lock+0x17/0x20 [ 29.724871] ? rtnl_lock+0x17/0x20 [ 29.728396] ? mutex_trylock+0x2a0/0x2a0 [ 29.732444] ? mark_held_locks+0xc9/0x160 [ 29.736580] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 29.741148] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.745630] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 29.750629] ? trace_hardirqs_on+0xd/0x10 [ 29.754765] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.759248] ? wait_for_completion_killable+0x56c/0x960 [ 29.764600] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 29.771071] ? lock_downgrade+0x8e0/0x8e0 [ 29.775200] ? kasan_check_read+0x11/0x20 [ 29.779330] ? do_raw_spin_unlock+0x9e/0x2e0 [ 29.783732] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 29.788291] ? wake_up_q+0x100/0x100 [ 29.791991] ? kasan_check_write+0x14/0x20 [ 29.796218] ? do_raw_spin_lock+0xc1/0x200 [ 29.800434] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.805966] ? __kthread_create_on_node+0x34f/0x4c0 [ 29.810964] ? __kthread_parkme+0x280/0x280 [ 29.815271] ? kasan_check_read+0x11/0x20 [ 29.819408] ? do_raw_spin_unlock+0x9e/0x2e0 [ 29.823804] ? __lock_is_held+0xb5/0x140 [ 29.827852] mutex_lock_nested+0x16/0x20 [ 29.831901] ? mutex_lock_nested+0x16/0x20 [ 29.836126] rtnl_lock+0x17/0x20 [ 29.839471] ip_mc_drop_socket+0x8f/0x270 [ 29.843597] inet_release+0x4e/0x1f0 [ 29.847302] sock_release+0x96/0x1b0 [ 29.851002] start_sync_thread+0xdc3/0x2d40 [ 29.855317] ? ip_vs_process_message+0xa0a/0xa0a [ 29.860060] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 29.864451] ? graph_lock+0x170/0x170 [ 29.868230] ? lock_downgrade+0x8e0/0x8e0 [ 29.872359] ? kasan_check_read+0x11/0x20 [ 29.876489] ? do_raw_spin_unlock+0x9e/0x2e0 [ 29.880874] ? find_held_lock+0x36/0x1c0 [ 29.884915] ? lock_downgrade+0x8e0/0x8e0 [ 29.889049] ? __release_sock+0x3a0/0x3a0 [ 29.893179] ? lock_release+0xa10/0xa10 [ 29.897133] ? check_same_owner+0x320/0x320 [ 29.901434] ? module_unload_free+0x5b0/0x5b0 [ 29.905917] do_ip_vs_set_ctl+0x59c/0x1d30 [ 29.910133] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 29.914611] ? lock_downgrade+0x8e0/0x8e0 [ 29.918740] ? kasan_check_read+0x11/0x20 [ 29.922867] ? rcu_is_watching+0x85/0x140 [ 29.926998] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 29.932175] ? kasan_check_write+0x14/0x20 [ 29.936398] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 29.941305] ? wait_for_completion+0x870/0x870 [ 29.945872] ? module_unload_free+0x5b0/0x5b0 [ 29.950361] nf_setsockopt+0x7d/0xd0 [ 29.954142] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 29.958617] ? nf_setsockopt+0x7d/0xd0 [ 29.962483] ip_setsockopt+0xd8/0xf0 [ 29.966180] raw_setsockopt+0xe2/0x100 [ 29.970053] sock_common_setsockopt+0x9a/0xe0 [ 29.974542] __sys_setsockopt+0x1bd/0x390 [ 29.978682] ? kernel_accept+0x310/0x310 [ 29.982743] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.988272] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 29.993097] __x64_sys_setsockopt+0xbe/0x150 [ 29.997486] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.002482] do_syscall_64+0x1b1/0x800 [ 30.006350] ? finish_task_switch+0x1ca/0x810 [ 30.010823] ? syscall_return_slowpath+0x5c0/0x5c0 [ 30.015740] ? syscall_return_slowpath+0x30f/0x5c0 [ 30.020661] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 30.026008] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.030836] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 30.036005] RIP: 0033:0x446aa9 [ 30.039185] RSP: 002b:00007f837d0c5db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 30.046870] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446aa9 [ 30.054119] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 [ 30.061368] RBP: 00000000006e29e0 R08: 0000000000000018 R09: 0000000000000000 [ 30.068615] R10: 0000000020000040 R11: 0000000000000246 R12: 0000000000000000 [ 30.075861] R13: 00007ffc2f4de32f R14: 00007f837d0c69c0 R15: 00000000006e2b60