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 '10.128.0.22' (ECDSA) to the list of known hosts. syzkaller login: [ 45.334423] IPVS: ftp: loaded support on port[0] = 21 [ 45.335484] IPVS: ftp: loaded support on port[0] = 21 [ 45.346104] IPVS: ftp: loaded support on port[0] = 21 [ 45.348299] IPVS: ftp: loaded support on port[0] = 21 [ 45.352521] IPVS: ftp: loaded support on port[0] = 21 [ 45.359296] IPVS: ftp: loaded support on port[0] = 21 [ 45.366923] IPVS: ftp: loaded support on port[0] = 21 [ 45.369729] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program [ 45.468465] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 45.477402] IPVS: stopping backup sync thread 4479 ... [ 45.485631] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 45.493114] IPVS: stopping backup sync thread 4487 ... [ 45.501506] IPVS: stopping backup sync thread 4484 ... [ 45.503124] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 executing program executing program executing program executing program executing program executing program executing program [ 45.507636] IPVS: stopping backup sync thread 4489 ... [ 45.520535] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 45.520585] IPVS: stopping backup sync thread 4494 ... [ 45.544947] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 45.558773] IPVS: stopping backup sync thread 4505 ... executing program [ 45.563044] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 45.564477] IPVS: stopping backup sync thread 4511 ... [ 45.572539] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 45.583084] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 45.586422] IPVS: stopping backup sync thread 4515 ... [ 45.595087] [ 45.601525] ============================================ [ 45.606952] WARNING: possible recursive locking detected [ 45.612388] 4.16.0+ #3 Not tainted [ 45.615900] -------------------------------------------- [ 45.621322] syzkaller380250/4504 is trying to acquire lock: [ 45.627024] 00000000662daf53 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 45.633852] [ 45.633852] but task is already holding lock: [ 45.639794] 00000000662daf53 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 45.646623] [ 45.646623] other info that might help us debug this: [ 45.653258] Possible unsafe locking scenario: [ 45.653258] [ 45.659288] CPU0 [ 45.661855] ---- [ 45.664407] lock(rtnl_mutex); [ 45.667660] lock(rtnl_mutex); [ 45.670913] [ 45.670913] *** DEADLOCK *** [ 45.670913] [ 45.676950] May be due to missing lock nesting notation [ 45.676950] [ 45.683852] 2 locks held by syzkaller380250/4504: [ 45.688663] #0: 00000000662daf53 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 45.695930] #1: 0000000056a513cb (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 45.704585] [ 45.704585] stack backtrace: [ 45.709070] CPU: 0 PID: 4504 Comm: syzkaller380250 Not tainted 4.16.0+ #3 [ 45.715992] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.725321] Call Trace: [ 45.727887] dump_stack+0x1b9/0x294 [ 45.731507] ? dump_stack_print_info.cold.2+0x52/0x52 [ 45.736672] ? print_lock+0xd1/0xd6 [ 45.740274] ? vprintk_func+0x81/0xe7 [ 45.744051] __lock_acquire.cold.62+0x18c/0x55b [ 45.748697] ? debug_check_no_locks_freed+0x310/0x310 [ 45.753860] ? account_kernel_stack+0x2bd/0x410 [ 45.758501] ? trace_hardirqs_on+0xd/0x10 [ 45.762623] ? put_task_stack+0x188/0x2c0 [ 45.766746] ? __lock_acquire+0x7f5/0x5140 [ 45.770959] ? copy_overflow+0x20/0x20 [ 45.774825] ? debug_check_no_locks_freed+0x310/0x310 [ 45.779992] ? __schedule+0x809/0x1e30 [ 45.783855] ? graph_lock+0x170/0x170 [ 45.787631] ? graph_lock+0x170/0x170 [ 45.791410] ? rcu_is_watching+0x85/0x140 [ 45.795537] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 45.800710] ? graph_lock+0x170/0x170 [ 45.804484] ? graph_lock+0x170/0x170 [ 45.808259] lock_acquire+0x1dc/0x520 [ 45.812049] ? rtnl_lock+0x17/0x20 [ 45.815573] ? lock_release+0xa10/0xa10 [ 45.819526] ? check_same_owner+0x320/0x320 [ 45.823823] ? schedule+0xef/0x430 [ 45.827338] ? rcu_note_context_switch+0x710/0x710 [ 45.832243] ? __schedule+0x1e30/0x1e30 [ 45.836192] ? __might_sleep+0x95/0x190 [ 45.840141] ? rtnl_lock+0x17/0x20 [ 45.843655] __mutex_lock+0x16d/0x17f0 [ 45.847518] ? rtnl_lock+0x17/0x20 [ 45.851032] ? rtnl_lock+0x17/0x20 [ 45.854545] ? mutex_trylock+0x2a0/0x2a0 [ 45.858580] ? mark_held_locks+0xc9/0x160 [ 45.862714] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 45.867273] ? _raw_spin_unlock_irq+0x27/0x70 [ 45.871742] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 45.876733] ? trace_hardirqs_on+0xd/0x10 [ 45.880855] ? _raw_spin_unlock_irq+0x27/0x70 [ 45.885327] ? wait_for_completion_killable+0x56c/0x960 [ 45.890668] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 45.897133] ? lock_downgrade+0x8e0/0x8e0 [ 45.901274] ? kasan_check_read+0x11/0x20 [ 45.905398] ? do_raw_spin_unlock+0x9e/0x2e0 [ 45.909782] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 45.914337] ? wake_up_q+0x100/0x100 [ 45.918027] ? kasan_check_write+0x14/0x20 [ 45.922237] ? do_raw_spin_lock+0xc1/0x200 [ 45.926449] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 45.931961] ? __kthread_create_on_node+0x34f/0x4c0 [ 45.936951] ? __kthread_parkme+0x280/0x280 [ 45.941247] ? kasan_check_read+0x11/0x20 [ 45.945368] ? do_raw_spin_unlock+0x9e/0x2e0 [ 45.949750] ? __lock_is_held+0xb5/0x140 [ 45.953784] mutex_lock_nested+0x16/0x20 [ 45.957818] ? mutex_lock_nested+0x16/0x20 [ 45.962026] rtnl_lock+0x17/0x20 [ 45.965369] ip_mc_drop_socket+0x8f/0x270 [ 45.969490] inet_release+0x4e/0x1f0 [ 45.973178] sock_release+0x96/0x1b0 [ 45.976868] start_sync_thread+0xdc3/0x2d40 [ 45.981167] ? ip_vs_process_message+0xa0a/0xa0a [ 45.985897] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 45.990278] ? graph_lock+0x170/0x170 [ 45.994053] ? lock_downgrade+0x8e0/0x8e0 [ 45.998174] ? lock_downgrade+0x8e0/0x8e0 [ 46.002296] ? kasan_check_read+0x11/0x20 [ 46.006418] ? do_raw_spin_unlock+0x9e/0x2e0 [ 46.010803] ? __local_bh_enable_ip+0x161/0x230 [ 46.015445] ? find_held_lock+0x36/0x1c0 [ 46.019483] ? lock_downgrade+0x8e0/0x8e0 [ 46.023603] ? lock_release+0xa10/0xa10 [ 46.027550] ? check_same_owner+0x320/0x320 [ 46.031847] ? module_unload_free+0x5b0/0x5b0 [ 46.036318] do_ip_vs_set_ctl+0x59c/0x1d30 [ 46.040526] ? find_held_lock+0x36/0x1c0 [ 46.044560] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 46.049030] ? lock_downgrade+0x8e0/0x8e0 [ 46.053163] ? kasan_check_read+0x11/0x20 [ 46.057286] ? rcu_is_watching+0x85/0x140 [ 46.061408] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 46.066575] ? kasan_check_write+0x14/0x20 [ 46.070787] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 46.075692] ? wait_for_completion+0x870/0x870 [ 46.080248] ? vm_insert_mixed_mkwrite+0x40/0x40 [ 46.084980] ? module_unload_free+0x5b0/0x5b0 [ 46.089446] ? find_held_lock+0x36/0x1c0 [ 46.093483] ? mutex_unlock+0xd/0x10 [ 46.097173] nf_setsockopt+0x7d/0xd0 [ 46.100861] ? nf_setsockopt+0x7d/0xd0 [ 46.104724] ip_setsockopt+0xd8/0xf0 [ 46.108411] tcp_setsockopt+0x93/0xe0 [ 46.112199] sock_common_setsockopt+0x9a/0xe0 [ 46.116668] __sys_setsockopt+0x1bd/0x390 [ 46.120814] ? kernel_accept+0x310/0x310 [ 46.124854] ? mm_fault_error+0x380/0x380 [ 46.128976] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 46.133791] SyS_setsockopt+0x34/0x50 [ 46.137565] ? SyS_recv+0x40/0x40 [ 46.140994] do_syscall_64+0x29e/0x9d0 [ 46.144857] ? vmalloc_sync_all+0x30/0x30 [ 46.148990] ? _raw_spin_unlock_irq+0x27/0x70 [ 46.153469] ? finish_task_switch+0x1ca/0x810 [ 46.157940] ? syscall_return_slowpath+0x5c0/0x5c0 [ 46.162842] ? syscall_return_slowpath+0x30f/0x5c0 [ 46.167747] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 46.173266] ? retint_user+0x18/0x18 [ 46.176960] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 46.181784] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 46.186955] RIP: 0033:0x446a39 [ 46.190123] RSP: 002b:00007f7e9f166db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 46.197806] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446a39 [ 46.205052] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 [ 46.212300] RBP: 00000000006e29e0 R08: 0000000000000018 R09: 0000000000000000 [ 46.219547] R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000 [ 46.226792] R13: 00007ffc576dfa8f R14: 00007f7e9f1679c0 R15: 00000000006e2b60 [ 46.239204] IPVS: stopping backup sync thread 4501 ...