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 '10.128.0.39' (ECDSA) to the list of known hosts. syzkaller login: [ 30.291882] IPVS: ftp: loaded support on port[0] = 21 [ 30.292389] IPVS: ftp: loaded support on port[0] = 21 [ 30.301740] IPVS: ftp: loaded support on port[0] = 21 [ 30.306355] IPVS: ftp: loaded support on port[0] = 21 [ 30.310111] IPVS: ftp: loaded support on port[0] = 21 [ 30.316587] IPVS: ftp: loaded support on port[0] = 21 [ 30.319705] IPVS: ftp: loaded support on port[0] = 21 [ 30.324452] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program [ 30.463889] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.492639] IPVS: stopping backup sync thread 4555 ... executing program executing program executing program executing program executing program executing program executing program executing program [ 30.534451] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.545711] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.564577] IPVS: stopping backup sync thread 4562 ... [ 30.569126] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.576745] IPVS: stopping backup sync thread 4568 ... executing program executing program executing program executing program [ 30.585500] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.588981] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.603252] IPVS: stopping backup sync thread 4579 ... [ 30.609671] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.613569] IPVS: stopping backup sync thread 4577 ... [ 30.626298] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.628960] IPVS: stopping backup sync thread 4587 ... [ 30.635148] [ 30.641708] ============================================ [ 30.644538] IPVS: stopping backup sync thread 4583 ... [ 30.647225] WARNING: possible recursive locking detected [ 30.647234] 4.16.0+ #2 Not tainted [ 30.647236] -------------------------------------------- [ 30.647242] syzkaller103517/4584 is trying to acquire lock: [ 30.647249] 000000003c4165fe (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 30.647279] [ 30.647279] but task is already holding lock: [ 30.647282] 000000003c4165fe (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 30.692299] [ 30.692299] other info that might help us debug this: [ 30.698972] Possible unsafe locking scenario: [ 30.698972] [ 30.705021] CPU0 [ 30.707598] ---- [ 30.710168] lock(rtnl_mutex); [ 30.713432] lock(rtnl_mutex); [ 30.716696] [ 30.716696] *** DEADLOCK *** [ 30.716696] [ 30.722748] May be due to missing lock nesting notation [ 30.722748] [ 30.729680] 2 locks held by syzkaller103517/4584: [ 30.734532] #0: 000000003c4165fe (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 30.741833] #1: 00000000fc4e0826 (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 30.750526] [ 30.750526] stack backtrace: [ 30.755034] CPU: 1 PID: 4584 Comm: syzkaller103517 Not tainted 4.16.0+ #2 [ 30.761955] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.771299] Call Trace: [ 30.773899] dump_stack+0x1b9/0x294 [ 30.777548] ? dump_stack_print_info.cold.2+0x52/0x52 [ 30.782749] ? print_lock+0xd1/0xd6 [ 30.786380] ? vprintk_func+0x81/0xe7 [ 30.790198] __lock_acquire.cold.62+0x18c/0x55b [ 30.794891] ? debug_check_no_locks_freed+0x310/0x310 [ 30.800093] ? __enqueue_entity+0x10d/0x1f0 [ 30.804436] ? __lock_acquire+0x7f5/0x5140 [ 30.808702] ? put_prev_task_fair+0x80/0x80 [ 30.813038] ? debug_check_no_locks_freed+0x310/0x310 [ 30.818256] ? select_idle_sibling+0xd70/0xd70 [ 30.823044] ? lock_downgrade+0x8e0/0x8e0 [ 30.827196] ? graph_lock+0x170/0x170 [ 30.831092] ? graph_lock+0x170/0x170 [ 30.834911] ? rcu_is_watching+0x85/0x140 [ 30.839075] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 30.844272] ? graph_lock+0x170/0x170 [ 30.848105] ? graph_lock+0x170/0x170 [ 30.851916] lock_acquire+0x1dc/0x520 [ 30.855722] ? rtnl_lock+0x17/0x20 [ 30.859262] ? lock_release+0xa10/0xa10 [ 30.863244] ? check_same_owner+0x320/0x320 [ 30.867573] ? graph_lock+0x170/0x170 [ 30.871376] ? rcu_note_context_switch+0x710/0x710 [ 30.876304] ? __might_sleep+0x95/0x190 [ 30.880283] ? rtnl_lock+0x17/0x20 [ 30.883834] __mutex_lock+0x16d/0x17f0 [ 30.887734] ? rtnl_lock+0x17/0x20 [ 30.891274] ? rtnl_lock+0x17/0x20 [ 30.894819] ? mutex_trylock+0x2a0/0x2a0 [ 30.898887] ? mark_held_locks+0xc9/0x160 [ 30.903041] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 30.907641] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.912146] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 30.917167] ? trace_hardirqs_on+0xd/0x10 [ 30.921335] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.925844] ? wait_for_completion_killable+0x56c/0x960 [ 30.931229] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 30.937723] ? lock_downgrade+0x8e0/0x8e0 [ 30.941878] ? kasan_check_read+0x11/0x20 [ 30.946131] ? do_raw_spin_unlock+0x9e/0x2e0 [ 30.950565] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 30.955166] ? wake_up_q+0x100/0x100 [ 30.958892] ? kasan_check_write+0x14/0x20 [ 30.963192] ? do_raw_spin_lock+0xc1/0x200 [ 30.967454] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 30.973004] ? __kthread_create_on_node+0x34f/0x4c0 [ 30.978044] ? __kthread_parkme+0x280/0x280 [ 30.982375] ? kasan_check_read+0x11/0x20 [ 30.986525] ? do_raw_spin_unlock+0x9e/0x2e0 [ 30.990935] ? __lock_is_held+0xb5/0x140 [ 30.994994] mutex_lock_nested+0x16/0x20 [ 30.999066] ? mutex_lock_nested+0x16/0x20 [ 31.003305] rtnl_lock+0x17/0x20 [ 31.006680] ip_mc_drop_socket+0x8f/0x270 [ 31.010846] inet_release+0x4e/0x1f0 [ 31.014565] sock_release+0x96/0x1b0 [ 31.018292] start_sync_thread+0xdc3/0x2d40 [ 31.022614] ? ip_vs_process_message+0xa0a/0xa0a [ 31.027376] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 31.031802] ? graph_lock+0x170/0x170 [ 31.035623] ? lock_downgrade+0x8e0/0x8e0 [ 31.039776] ? kasan_check_read+0x11/0x20 [ 31.043921] ? do_raw_spin_unlock+0x9e/0x2e0 [ 31.048338] ? find_held_lock+0x36/0x1c0 [ 31.052401] ? lock_downgrade+0x8e0/0x8e0 [ 31.056647] ? __release_sock+0x3a0/0x3a0 [ 31.060800] ? lock_release+0xa10/0xa10 [ 31.064775] ? check_same_owner+0x320/0x320 [ 31.069104] ? module_unload_free+0x5b0/0x5b0 [ 31.073602] do_ip_vs_set_ctl+0x59c/0x1d30 [ 31.077835] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 31.082331] ? lock_downgrade+0x8e0/0x8e0 [ 31.086486] ? kasan_check_read+0x11/0x20 [ 31.090643] ? rcu_is_watching+0x85/0x140 [ 31.094799] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 31.100001] ? kasan_check_write+0x14/0x20 [ 31.104245] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 31.109614] ? wait_for_completion+0x870/0x870 [ 31.114212] ? module_unload_free+0x5b0/0x5b0 [ 31.118722] nf_setsockopt+0x7d/0xd0 [ 31.122442] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 31.126938] ? nf_setsockopt+0x7d/0xd0 [ 31.130828] ip_setsockopt+0xd8/0xf0 [ 31.134577] udp_setsockopt+0x62/0xa0 [ 31.138393] sock_common_setsockopt+0x9a/0xe0 [ 31.142898] __sys_setsockopt+0x1bd/0x390 [ 31.147060] ? kernel_accept+0x310/0x310 [ 31.151119] ? lock_downgrade+0x8e0/0x8e0 [ 31.155274] ? kasan_check_read+0x11/0x20 [ 31.159435] ? do_raw_spin_unlock+0x9e/0x2e0 [ 31.163861] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 31.168469] SyS_setsockopt+0x34/0x50 [ 31.172278] ? SyS_recv+0x40/0x40 [ 31.175749] do_syscall_64+0x29e/0x9d0 [ 31.179649] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.184162] ? finish_task_switch+0x1ca/0x810 [ 31.188681] ? syscall_return_slowpath+0x5c0/0x5c0 [ 31.193609] ? syscall_return_slowpath+0x30f/0x5c0 [ 31.198548] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 31.203928] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.208783] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 31.213975] RIP: 0033:0x447a99 [ 31.217166] RSP: 002b:00007f0d311bbce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 31.224985] RAX: ffffffffffffffda RBX: 00000000006e39fc RCX: 0000000000447a99 executing program [ 31.232249] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 [ 31.239538] RBP: 00000000006e39f8 R08: 0000000000000018 R09: 0000000000000000 [ 31.246802] R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000 [ 31.254070] R13: 00007ffcc339179f R14: 00007f0d311bc9c0 R15: 0000000000002710 [ 31.270340] IPVS: stopping backup sync thread 4592 ...