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 '10.128.0.51' (ECDSA) to the list of known hosts. syzkaller login: [ 40.900008] IPVS: ftp: loaded support on port[0] = 21 [ 40.902768] IPVS: ftp: loaded support on port[0] = 21 [ 40.909866] IPVS: ftp: loaded support on port[0] = 21 [ 40.913042] IPVS: ftp: loaded support on port[0] = 21 [ 40.918637] IPVS: ftp: loaded support on port[0] = 21 [ 40.925959] IPVS: ftp: loaded support on port[0] = 21 [ 40.929041] IPVS: ftp: loaded support on port[0] = 21 [ 40.932417] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program [ 41.025174] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 41.025310] IPVS: stopping backup sync thread 4496 ... [ 41.060917] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 executing program executing program executing program executing program executing program [ 41.071116] IPVS: stopping backup sync thread 4502 ... [ 41.073379] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 41.087231] IPVS: stopping backup sync thread 4500 ... [ 41.092976] IPVS: stopping backup sync thread 4508 ... [ 41.100545] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 41.100616] IPVS: stopping backup sync thread 4513 ... [ 41.111423] IPVS: stopping backup sync thread 4522 ... [ 41.114652] [ 41.121366] ============================================ [ 41.126789] WARNING: possible recursive locking detected [ 41.132212] 4.16.0+ #1 Not tainted [ 41.135724] -------------------------------------------- [ 41.141146] syzkaller159081/4505 is trying to acquire lock: [ 41.146832] 00000000dfb0019b (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 41.153659] [ 41.153659] but task is already holding lock: [ 41.159606] 00000000dfb0019b (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 41.166426] [ 41.166426] other info that might help us debug this: [ 41.173064] Possible unsafe locking scenario: [ 41.173064] [ 41.179095] CPU0 [ 41.181649] ---- [ 41.184203] lock(rtnl_mutex); [ 41.187456] lock(rtnl_mutex); [ 41.190709] [ 41.190709] *** DEADLOCK *** [ 41.190709] [ 41.196741] May be due to missing lock nesting notation [ 41.196741] [ 41.203644] 2 locks held by syzkaller159081/4505: [ 41.208454] #0: 00000000dfb0019b (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 41.215711] #1: 0000000028c6bf84 (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 41.224357] [ 41.224357] stack backtrace: [ 41.228833] CPU: 0 PID: 4505 Comm: syzkaller159081 Not tainted 4.16.0+ #1 [ 41.235730] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.245054] Call Trace: [ 41.247619] dump_stack+0x1b9/0x294 [ 41.251221] ? dump_stack_print_info.cold.2+0x52/0x52 [ 41.256385] ? print_lock+0xd1/0xd6 [ 41.259988] ? vprintk_func+0x81/0xe7 [ 41.263765] __lock_acquire.cold.62+0x18c/0x55b [ 41.268409] ? debug_check_no_locks_freed+0x310/0x310 [ 41.273574] ? __enqueue_entity+0x10d/0x1f0 [ 41.277868] ? __lock_is_held+0xb5/0x140 [ 41.281905] ? __lock_acquire+0x7f5/0x5140 [ 41.286115] ? update_curr+0x332/0xbe0 [ 41.289979] ? debug_check_no_locks_freed+0x310/0x310 [ 41.295144] ? select_idle_sibling+0xd70/0xd70 [ 41.299699] ? find_held_lock+0x36/0x1c0 [ 41.303735] ? graph_lock+0x170/0x170 [ 41.307515] ? graph_lock+0x170/0x170 [ 41.311290] ? graph_lock+0x170/0x170 [ 41.315066] lock_acquire+0x1dc/0x520 [ 41.318840] ? rtnl_lock+0x17/0x20 [ 41.322356] ? lock_release+0xa10/0xa10 [ 41.326306] ? check_same_owner+0x320/0x320 [ 41.330599] ? graph_lock+0x170/0x170 [ 41.334377] ? rcu_note_context_switch+0x710/0x710 [ 41.339280] ? __might_sleep+0x95/0x190 [ 41.343229] ? rtnl_lock+0x17/0x20 [ 41.346751] __mutex_lock+0x16d/0x17f0 [ 41.350612] ? rtnl_lock+0x17/0x20 [ 41.354126] ? rtnl_lock+0x17/0x20 [ 41.357640] ? mutex_trylock+0x2a0/0x2a0 [ 41.361674] ? mark_held_locks+0xc9/0x160 [ 41.365798] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 41.370352] ? _raw_spin_unlock_irq+0x27/0x70 [ 41.374824] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.379830] ? trace_hardirqs_on+0xd/0x10 [ 41.383985] ? _raw_spin_unlock_irq+0x27/0x70 [ 41.388475] ? wait_for_completion_killable+0x56c/0x960 [ 41.393814] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 41.400277] ? lock_downgrade+0x8e0/0x8e0 [ 41.404400] ? kasan_check_read+0x11/0x20 [ 41.408520] ? do_raw_spin_unlock+0x9e/0x2e0 [ 41.412904] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 41.417548] ? wake_up_q+0x100/0x100 [ 41.421236] ? kasan_check_write+0x14/0x20 [ 41.425444] ? do_raw_spin_lock+0xc1/0x200 [ 41.429654] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 41.435166] ? __kthread_create_on_node+0x34f/0x4c0 [ 41.440158] ? __kthread_parkme+0x280/0x280 [ 41.444454] ? kasan_check_read+0x11/0x20 [ 41.448575] ? do_raw_spin_unlock+0x9e/0x2e0 [ 41.452959] ? __lock_is_held+0xb5/0x140 [ 41.456994] mutex_lock_nested+0x16/0x20 [ 41.461028] ? mutex_lock_nested+0x16/0x20 [ 41.465238] rtnl_lock+0x17/0x20 [ 41.468582] ip_mc_drop_socket+0x8f/0x270 [ 41.472706] inet_release+0x4e/0x1f0 [ 41.476396] sock_release+0x96/0x1b0 [ 41.480087] start_sync_thread+0xdc3/0x2d40 [ 41.484384] ? __lock_acquire+0x7f5/0x5140 [ 41.488592] ? ip_vs_process_message+0xa0a/0xa0a [ 41.493324] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 41.497706] ? graph_lock+0x170/0x170 [ 41.501478] ? lock_downgrade+0x8e0/0x8e0 [ 41.505601] ? lock_downgrade+0x8e0/0x8e0 [ 41.509723] ? kasan_check_read+0x11/0x20 [ 41.513859] ? do_raw_spin_unlock+0x9e/0x2e0 [ 41.518243] ? __local_bh_enable_ip+0x161/0x230 [ 41.522886] ? find_held_lock+0x36/0x1c0 [ 41.526926] ? lock_downgrade+0x8e0/0x8e0 [ 41.531048] ? lock_release+0xa10/0xa10 [ 41.535000] ? check_same_owner+0x320/0x320 [ 41.539297] ? module_unload_free+0x5b0/0x5b0 [ 41.543771] do_ip_vs_set_ctl+0x59c/0x1d30 [ 41.547980] ? find_held_lock+0x36/0x1c0 [ 41.552016] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 41.556487] ? lock_downgrade+0x8e0/0x8e0 [ 41.560610] ? kasan_check_read+0x11/0x20 [ 41.564736] ? rcu_is_watching+0x85/0x140 [ 41.568859] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 41.574023] ? kasan_check_write+0x14/0x20 [ 41.578233] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 41.583139] ? wait_for_completion+0x870/0x870 [ 41.587700] ? module_unload_free+0x5b0/0x5b0 [ 41.592174] ? kasan_check_read+0x11/0x20 [ 41.596295] ? __lock_is_held+0xb5/0x140 [ 41.600330] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 41.605497] ? mutex_unlock+0xd/0x10 [ 41.609188] nf_setsockopt+0x7d/0xd0 [ 41.612877] ? nf_setsockopt+0x7d/0xd0 [ 41.616744] ip_setsockopt+0xd8/0xf0 [ 41.620436] tcp_setsockopt+0x93/0xe0 [ 41.624214] sock_common_setsockopt+0x9a/0xe0 [ 41.628685] __sys_setsockopt+0x1bd/0x390 [ 41.632811] ? kernel_accept+0x310/0x310 [ 41.636849] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 41.642363] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 41.647181] SyS_setsockopt+0x34/0x50 [ 41.650954] ? SyS_recv+0x40/0x40 [ 41.654380] do_syscall_64+0x29e/0x9d0 [ 41.658241] ? vmalloc_sync_all+0x30/0x30 [ 41.662365] ? _raw_spin_unlock_irq+0x27/0x70 [ 41.666836] ? finish_task_switch+0x1ca/0x810 [ 41.671306] ? syscall_return_slowpath+0x5c0/0x5c0 [ 41.676209] ? syscall_return_slowpath+0x30f/0x5c0 [ 41.681116] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 41.686454] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 41.691273] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 41.696435] RIP: 0033:0x446a99 [ 41.699596] RSP: 002b:00007fab18ef8db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 41.707278] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446a99 [ 41.714522] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000004 [ 41.721767] RBP: 00000000006e29e0 R08: 0000000000000018 R09: 0000000000000000 [ 41.729010] R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000 [ 41.736252] R13: 00007ffe125bf5cf R14: 00007fab18ef99c0 R15: 0000000000000004