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 Warning: Permanently added '10.128.0.4' (ECDSA) to the list of known hosts. syzkaller login: [ 37.157994] IPVS: ftp: loaded support on port[0] = 21 [ 37.158070] IPVS: ftp: loaded support on port[0] = 21 [ 37.167865] IPVS: ftp: loaded support on port[0] = 21 [ 37.172123] IPVS: ftp: loaded support on port[0] = 21 [ 37.176249] IPVS: ftp: loaded support on port[0] = 21 [ 37.182210] IPVS: ftp: loaded support on port[0] = 21 [ 37.187290] IPVS: ftp: loaded support on port[0] = 21 [ 37.193229] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program [ 37.295972] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 37.304583] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 37.319148] IPVS: stopping backup sync thread 4545 ... [ 37.326326] IPVS: stopping backup sync thread 4550 ... [ 37.333180] IPVS: stopping backup sync thread 4548 ... executing program executing program executing program executing program executing program executing program executing program [ 37.351420] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 37.361240] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 37.363870] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 37.378709] IPVS: stopping backup sync thread 4565 ... [ 37.382259] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 37.385814] IPVS: stopping backup sync thread 4556 ... [ 37.398291] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 37.399510] IPVS: stopping backup sync thread 4570 ... [ 37.409201] [ 37.413626] ============================================ [ 37.419073] WARNING: possible recursive locking detected [ 37.421936] IPVS: stopping backup sync thread 4567 ... [ 37.424500] 4.16.0+ #1 Not tainted [ 37.424503] -------------------------------------------- [ 37.424507] syzkaller492405/4566 is trying to acquire lock: [ 37.424511] 00000000282b24cd (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 37.424539] [ 37.424539] but task is already holding lock: [ 37.457235] 00000000282b24cd (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 37.464069] [ 37.464069] other info that might help us debug this: [ 37.470709] Possible unsafe locking scenario: [ 37.470709] [ 37.476755] CPU0 [ 37.479311] ---- [ 37.481864] lock(rtnl_mutex); [ 37.485118] lock(rtnl_mutex); [ 37.488371] [ 37.488371] *** DEADLOCK *** [ 37.488371] [ 37.494404] May be due to missing lock nesting notation [ 37.494404] [ 37.501314] 2 locks held by syzkaller492405/4566: [ 37.506128] #0: 00000000282b24cd (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 37.513406] #1: 00000000362b868f (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 37.522065] [ 37.522065] stack backtrace: [ 37.526561] CPU: 1 PID: 4566 Comm: syzkaller492405 Not tainted 4.16.0+ #1 [ 37.533460] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.542786] Call Trace: [ 37.545367] dump_stack+0x1b9/0x294 [ 37.548977] ? dump_stack_print_info.cold.2+0x52/0x52 [ 37.554144] ? print_lock+0xd1/0xd6 [ 37.557762] ? vprintk_func+0x81/0xe7 [ 37.561551] __lock_acquire.cold.62+0x18c/0x55b [ 37.566203] ? debug_check_no_locks_freed+0x310/0x310 [ 37.571371] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.575841] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 37.580832] ? trace_hardirqs_on+0xd/0x10 [ 37.584959] ? __lock_acquire+0x7f5/0x5140 [ 37.589168] ? copy_overflow+0x20/0x20 [ 37.593043] ? __schedule+0x809/0x1e30 [ 37.596905] ? graph_lock+0x170/0x170 [ 37.600683] ? kasan_check_read+0x11/0x20 [ 37.604806] ? graph_lock+0x170/0x170 [ 37.608579] ? graph_lock+0x170/0x170 [ 37.612369] lock_acquire+0x1dc/0x520 [ 37.616169] ? rtnl_lock+0x17/0x20 [ 37.619698] ? lock_release+0xa10/0xa10 [ 37.623650] ? check_same_owner+0x320/0x320 [ 37.627952] ? schedule+0xef/0x430 [ 37.631470] ? rcu_note_context_switch+0x710/0x710 [ 37.636373] ? __schedule+0x1e30/0x1e30 [ 37.640321] ? __might_sleep+0x95/0x190 [ 37.644272] ? rtnl_lock+0x17/0x20 [ 37.647796] __mutex_lock+0x16d/0x17f0 [ 37.651746] ? rtnl_lock+0x17/0x20 [ 37.655262] ? rtnl_lock+0x17/0x20 [ 37.658776] ? mutex_trylock+0x2a0/0x2a0 [ 37.662813] ? mark_held_locks+0xc9/0x160 [ 37.666937] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 37.671491] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.675970] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 37.680963] ? trace_hardirqs_on+0xd/0x10 [ 37.685087] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.689557] ? wait_for_completion_killable+0x56c/0x960 [ 37.694901] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 37.701385] ? lock_downgrade+0x8e0/0x8e0 [ 37.705517] ? kasan_check_read+0x11/0x20 [ 37.709650] ? do_raw_spin_unlock+0x9e/0x2e0 [ 37.714033] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 37.718593] ? wake_up_q+0x100/0x100 [ 37.722283] ? kasan_check_write+0x14/0x20 [ 37.726493] ? do_raw_spin_lock+0xc1/0x200 [ 37.730707] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 37.736228] ? __kthread_create_on_node+0x34f/0x4c0 [ 37.741220] ? __kthread_parkme+0x280/0x280 [ 37.745518] ? kasan_check_read+0x11/0x20 [ 37.749642] ? do_raw_spin_unlock+0x9e/0x2e0 [ 37.754025] ? __lock_is_held+0xb5/0x140 [ 37.758072] mutex_lock_nested+0x16/0x20 [ 37.762111] ? mutex_lock_nested+0x16/0x20 [ 37.766332] rtnl_lock+0x17/0x20 [ 37.769677] ip_mc_drop_socket+0x8f/0x270 [ 37.773804] inet_release+0x4e/0x1f0 [ 37.777495] sock_release+0x96/0x1b0 [ 37.781184] start_sync_thread+0xdc3/0x2d40 [ 37.785483] ? __lock_acquire+0x7f5/0x5140 [ 37.789693] ? ip_vs_process_message+0xa0a/0xa0a [ 37.794423] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 37.798807] ? graph_lock+0x170/0x170 [ 37.802581] ? lock_downgrade+0x8e0/0x8e0 [ 37.806705] ? lock_downgrade+0x8e0/0x8e0 [ 37.810833] ? kasan_check_read+0x11/0x20 [ 37.814958] ? do_raw_spin_unlock+0x9e/0x2e0 [ 37.819348] ? __local_bh_enable_ip+0x161/0x230 [ 37.823994] ? find_held_lock+0x36/0x1c0 [ 37.828029] ? lock_downgrade+0x8e0/0x8e0 [ 37.832151] ? lock_release+0xa10/0xa10 [ 37.836101] ? check_same_owner+0x320/0x320 [ 37.840413] ? module_unload_free+0x5b0/0x5b0 [ 37.844899] do_ip_vs_set_ctl+0x59c/0x1d30 [ 37.849109] ? find_held_lock+0x36/0x1c0 [ 37.853147] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 37.857616] ? lock_downgrade+0x8e0/0x8e0 [ 37.861741] ? kasan_check_read+0x11/0x20 [ 37.865864] ? rcu_is_watching+0x85/0x140 [ 37.869987] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 37.875156] ? kasan_check_write+0x14/0x20 [ 37.879369] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 37.884274] ? wait_for_completion+0x870/0x870 [ 37.888836] ? module_unload_free+0x5b0/0x5b0 [ 37.893306] ? fget_raw+0x20/0x20 [ 37.896737] ? mutex_unlock+0xd/0x10 [ 37.900430] nf_setsockopt+0x7d/0xd0 [ 37.904118] ? nf_setsockopt+0x7d/0xd0 [ 37.907984] ip_setsockopt+0xd8/0xf0 [ 37.911675] tcp_setsockopt+0x93/0xe0 [ 37.915455] sock_common_setsockopt+0x9a/0xe0 [ 37.919928] __sys_setsockopt+0x1bd/0x390 [ 37.924053] ? kernel_accept+0x310/0x310 [ 37.928090] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 37.933607] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 37.938425] SyS_setsockopt+0x34/0x50 [ 37.942198] ? SyS_recv+0x40/0x40 [ 37.945630] do_syscall_64+0x29e/0x9d0 [ 37.949493] ? vmalloc_sync_all+0x30/0x30 [ 37.953617] ? _raw_spin_unlock_irq+0x27/0x70 [ 37.958090] ? finish_task_switch+0x1ca/0x810 [ 37.962562] ? syscall_return_slowpath+0x5c0/0x5c0 [ 37.967468] ? syscall_return_slowpath+0x30f/0x5c0 [ 37.972374] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 37.977715] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 37.982532] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 37.987696] RIP: 0033:0x447839 [ 37.990859] RSP: 002b:00007f3bf6ce5ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 executing program [ 37.998540] RAX: ffffffffffffffda RBX: 00000000006e39e4 RCX: 0000000000447839 [ 38.005782] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 [ 38.013026] RBP: 00000000006e39e0 R08: 0000000000000018 R09: 0000000000000000 [ 38.020269] R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000 [ 38.027513] R13: 00007ffe27c01acf R14: 00007f3bf6ce69c0 R15: 0000000000002710 [ 38.039658] IPVS: stopping backup sync thread 4576 ...