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 '10.128.0.41' (ECDSA) to the list of known hosts. syzkaller login: [ 30.019771] IPVS: ftp: loaded support on port[0] = 21 [ 30.019777] IPVS: ftp: loaded support on port[0] = 21 [ 30.031368] IPVS: ftp: loaded support on port[0] = 21 [ 30.035531] IPVS: ftp: loaded support on port[0] = 21 [ 30.039131] IPVS: ftp: loaded support on port[0] = 21 [ 30.044585] IPVS: ftp: loaded support on port[0] = 21 [ 30.048738] IPVS: ftp: loaded support on port[0] = 21 [ 30.052564] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program [ 30.179153] IPVS: stopping backup sync thread 4492 ... executing program executing program executing program executing program [ 30.201458] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.210435] IPVS: stopping backup sync thread 4503 ... [ 30.213326] IPVS: stopping backup sync thread 4501 ... [ 30.225506] IPVS: stopping backup sync thread 4509 ... [ 30.229985] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.233929] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 executing program executing program executing program executing program [ 30.240310] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.254982] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.260315] IPVS: stopping backup sync thread 4516 ... [ 30.272822] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.272839] IPVS: stopping backup sync thread 4521 ... [ 30.283972] IPVS: stopping backup sync thread 4528 ... [ 30.287445] [ 30.293522] ============================================ executing program executing program [ 30.297460] IPVS: stopping backup sync thread 4515 ... [ 30.298957] WARNING: possible recursive locking detected [ 30.298962] 4.16.0+ #5 Not tainted [ 30.298964] -------------------------------------------- [ 30.298968] syzkaller409319/4508 is trying to acquire lock: [ 30.298972] 0000000054ef9768 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 30.298996] [ 30.298996] but task is already holding lock: [ 30.337086] 0000000054ef9768 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 30.343925] [ 30.343925] other info that might help us debug this: [ 30.350575] Possible unsafe locking scenario: [ 30.350575] [ 30.356606] CPU0 [ 30.359162] ---- [ 30.361718] lock(rtnl_mutex); [ 30.364978] lock(rtnl_mutex); [ 30.368231] [ 30.368231] *** DEADLOCK *** [ 30.368231] [ 30.374273] May be due to missing lock nesting notation [ 30.374273] [ 30.381184] 2 locks held by syzkaller409319/4508: [ 30.386006] #0: 0000000054ef9768 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 30.393279] #1: 000000001913b2ba (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 30.401946] [ 30.401946] stack backtrace: [ 30.406427] CPU: 1 PID: 4508 Comm: syzkaller409319 Not tainted 4.16.0+ #5 [ 30.413335] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.422662] Call Trace: [ 30.425232] dump_stack+0x1b9/0x294 [ 30.428835] ? dump_stack_print_info.cold.2+0x52/0x52 [ 30.434004] ? print_lock+0xd1/0xd6 [ 30.437610] ? vprintk_func+0x81/0xe7 [ 30.441389] __lock_acquire.cold.62+0x18c/0x55b [ 30.446039] ? debug_check_no_locks_freed+0x310/0x310 [ 30.451207] ? __enqueue_entity+0x10d/0x1f0 [ 30.455511] ? __lock_acquire+0x7f5/0x5140 [ 30.459730] ? put_prev_task_fair+0x80/0x80 [ 30.464034] ? debug_check_no_locks_freed+0x310/0x310 [ 30.469210] ? trace_hardirqs_on+0xd/0x10 [ 30.473336] ? debug_check_no_locks_freed+0x310/0x310 [ 30.478506] ? select_idle_sibling+0xd70/0xd70 [ 30.483063] ? lock_downgrade+0x8e0/0x8e0 [ 30.487188] ? graph_lock+0x170/0x170 [ 30.490965] ? graph_lock+0x170/0x170 [ 30.494743] ? rcu_is_watching+0x85/0x140 [ 30.498868] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 30.504100] ? graph_lock+0x170/0x170 [ 30.507876] ? graph_lock+0x170/0x170 [ 30.511651] lock_acquire+0x1dc/0x520 [ 30.515432] ? rtnl_lock+0x17/0x20 [ 30.518948] ? lock_release+0xa10/0xa10 [ 30.522898] ? check_same_owner+0x320/0x320 [ 30.527204] ? graph_lock+0x170/0x170 [ 30.530984] ? rcu_note_context_switch+0x710/0x710 [ 30.535891] ? __might_sleep+0x95/0x190 [ 30.539840] ? rtnl_lock+0x17/0x20 [ 30.543355] __mutex_lock+0x16d/0x17f0 [ 30.547217] ? rtnl_lock+0x17/0x20 [ 30.550731] ? rtnl_lock+0x17/0x20 [ 30.554249] ? mutex_trylock+0x2a0/0x2a0 [ 30.558289] ? mark_held_locks+0xc9/0x160 [ 30.562413] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 30.566971] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.571454] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.576457] ? trace_hardirqs_on+0xd/0x10 [ 30.580580] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.585055] ? wait_for_completion_killable+0x56c/0x960 [ 30.590397] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 30.596869] ? lock_downgrade+0x8e0/0x8e0 [ 30.600996] ? kasan_check_read+0x11/0x20 [ 30.605121] ? do_raw_spin_unlock+0x9e/0x2e0 [ 30.609504] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 30.614064] ? wake_up_q+0x100/0x100 [ 30.617756] ? kasan_check_write+0x14/0x20 [ 30.621965] ? do_raw_spin_lock+0xc1/0x200 [ 30.626181] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.631696] ? __kthread_create_on_node+0x34f/0x4c0 [ 30.636687] ? __kthread_parkme+0x280/0x280 [ 30.640996] ? kasan_check_read+0x11/0x20 [ 30.645120] ? do_raw_spin_unlock+0x9e/0x2e0 [ 30.649513] ? __lock_is_held+0xb5/0x140 [ 30.653553] mutex_lock_nested+0x16/0x20 [ 30.657677] ? mutex_lock_nested+0x16/0x20 [ 30.661888] rtnl_lock+0x17/0x20 [ 30.665232] ip_mc_drop_socket+0x8f/0x270 [ 30.669355] inet_release+0x4e/0x1f0 [ 30.673049] sock_release+0x96/0x1b0 [ 30.676742] start_sync_thread+0xdc3/0x2d40 [ 30.681058] ? ip_vs_process_message+0xa0a/0xa0a [ 30.685790] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 30.690173] ? graph_lock+0x170/0x170 [ 30.693950] ? lock_downgrade+0x8e0/0x8e0 [ 30.698073] ? lock_downgrade+0x8e0/0x8e0 [ 30.702200] ? kasan_check_read+0x11/0x20 [ 30.706339] ? do_raw_spin_unlock+0x9e/0x2e0 [ 30.710741] ? __local_bh_enable_ip+0x161/0x230 [ 30.715402] ? find_held_lock+0x36/0x1c0 [ 30.719447] ? lock_downgrade+0x8e0/0x8e0 [ 30.723572] ? lock_release+0xa10/0xa10 [ 30.727525] ? check_same_owner+0x320/0x320 [ 30.731834] ? module_unload_free+0x5b0/0x5b0 [ 30.736327] do_ip_vs_set_ctl+0x59c/0x1d30 [ 30.740557] ? find_held_lock+0x36/0x1c0 [ 30.744596] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 30.749068] ? lock_downgrade+0x8e0/0x8e0 [ 30.753194] ? kasan_check_read+0x11/0x20 [ 30.757316] ? rcu_is_watching+0x85/0x140 [ 30.761444] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 30.766612] ? kasan_check_write+0x14/0x20 [ 30.770828] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 30.775746] ? wait_for_completion+0x870/0x870 [ 30.780311] ? vm_insert_mixed_mkwrite+0x40/0x40 [ 30.785052] ? module_unload_free+0x5b0/0x5b0 [ 30.789523] ? find_held_lock+0x36/0x1c0 [ 30.793564] ? mutex_unlock+0xd/0x10 [ 30.797257] nf_setsockopt+0x7d/0xd0 [ 30.800946] ? nf_setsockopt+0x7d/0xd0 [ 30.804810] ip_setsockopt+0xd8/0xf0 [ 30.808502] tcp_setsockopt+0x93/0xe0 [ 30.812279] sock_common_setsockopt+0x9a/0xe0 [ 30.816767] __sys_setsockopt+0x1bd/0x390 [ 30.820898] ? kernel_accept+0x310/0x310 [ 30.824940] ? mm_fault_error+0x380/0x380 [ 30.829065] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 30.833886] SyS_setsockopt+0x34/0x50 [ 30.837677] ? SyS_recv+0x40/0x40 [ 30.841123] do_syscall_64+0x29e/0x9d0 [ 30.845007] ? vmalloc_sync_all+0x30/0x30 [ 30.849135] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.853609] ? finish_task_switch+0x1ca/0x810 [ 30.858092] ? syscall_return_slowpath+0x5c0/0x5c0 [ 30.863005] ? syscall_return_slowpath+0x30f/0x5c0 [ 30.867918] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.873432] ? retint_user+0x18/0x18 [ 30.877125] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.881956] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 30.887135] RIP: 0033:0x447c09 [ 30.890303] RSP: 002b:00007f165ec14db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 30.897989] RAX: ffffffffffffffda RBX: 0000000000700024 RCX: 0000000000447c09 [ 30.905245] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 [ 30.912491] RBP: 0000000000700020 R08: 0000000000000018 R09: 0000000000000000 [ 30.919753] R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000 [ 30.927021] R13: 000000000080fe4f R14: 00007f165ec159c0 R15: 0000000000002710