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: [ 34.385431] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program [ 34.413399] IPVS: ftp: loaded support on port[0] = 21 [ 34.418497] IPVS: stopping backup sync thread 4426 ... [ 34.433554] IPVS: stopping backup sync thread 4429 ... [ 34.448709] IPVS: ftp: loaded support on port[0] = 21 [ 34.451162] IPVS: stopping backup sync thread 4434 ... executing program executing program executing program executing program [ 34.462068] IPVS: stopping backup sync thread 4435 ... [ 34.466074] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 [ 34.475165] IPVS: stopping backup sync thread 4438 ... [ 34.481363] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 [ 34.498466] IPVS: ftp: loaded support on port[0] = 21 [ 34.503817] IPVS: stopping backup sync thread 4443 ... executing program executing program [ 34.517085] IPVS: stopping backup sync thread 4445 ... [ 34.520080] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 [ 34.528784] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 [ 34.531941] IPVS: stopping backup sync thread 4449 ... [ 34.540102] IPVS: stopping backup sync thread 4450 ... [ 34.546251] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 executing program executing program executing program executing program executing program [ 34.567509] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 [ 34.567551] IPVS: stopping backup sync thread 4453 ... [ 34.584126] IPVS: stopping backup sync thread 4456 ... [ 34.589949] IPVS: ftp: loaded support on port[0] = 21 [ 34.603979] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 [ 34.604334] IPVS: stopping backup sync thread 4462 ... [ 34.618296] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 [ 34.618605] IPVS: stopping backup sync thread 4466 ... [ 34.632326] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 0, id = 0 [ 34.632739] IPVS: stopping backup sync thread 4467 ... [ 34.643764] [ 34.647837] ============================================ [ 34.653253] WARNING: possible recursive locking detected [ 34.658675] 4.16.0-rc7+ #3 Not tainted [ 34.662529] -------------------------------------------- [ 34.667985] syzkaller982306/4465 is trying to acquire lock: [ 34.673674] (rtnl_mutex){+.+.}, at: [<0000000015f99aa6>] rtnl_lock+0x17/0x20 [ 34.680934] [ 34.680934] but task is already holding lock: [ 34.686879] (rtnl_mutex){+.+.}, at: [<0000000015f99aa6>] rtnl_lock+0x17/0x20 [ 34.694130] [ 34.694130] other info that might help us debug this: [ 34.700761] Possible unsafe locking scenario: [ 34.700761] [ 34.706784] CPU0 [ 34.709333] ---- [ 34.711884] lock(rtnl_mutex); [ 34.715131] lock(rtnl_mutex); [ 34.718377] [ 34.718377] *** DEADLOCK *** [ 34.718377] [ 34.724401] May be due to missing lock nesting notation [ 34.724401] [ 34.731294] 2 locks held by syzkaller982306/4465: [ 34.736101] #0: (rtnl_mutex){+.+.}, at: [<0000000015f99aa6>] rtnl_lock+0x17/0x20 [ 34.743784] #1: (ipvs->sync_mutex){+.+.}, at: [<000000008e567985>] do_ip_vs_set_ctl+0x10f8/0x1cc0 [ 34.752942] [ 34.752942] stack backtrace: [ 34.757408] CPU: 0 PID: 4465 Comm: syzkaller982306 Not tainted 4.16.0-rc7+ #3 [ 34.764648] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.773969] Call Trace: [ 34.776532] dump_stack+0x194/0x24d [ 34.780131] ? arch_local_irq_restore+0x53/0x53 [ 34.784773] __lock_acquire+0xe8f/0x3e00 [ 34.788803] ? rcu_read_unlock+0x35/0x70 [ 34.792836] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 34.797996] ? account_entity_enqueue+0x3c8/0x6e0 [ 34.802812] ? __lock_acquire+0x664/0x3e00 [ 34.807018] ? __enqueue_entity+0x109/0x1e0 [ 34.811317] ? select_idle_sibling+0x86d/0xda0 [ 34.815878] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 34.821041] ? find_held_lock+0x35/0x1d0 [ 34.825074] ? select_task_rq_fair+0xaa7/0x2910 [ 34.829711] ? lock_downgrade+0x980/0x980 [ 34.833829] ? __lock_acquire+0x664/0x3e00 [ 34.838040] ? trace_hardirqs_off+0x10/0x10 [ 34.842332] ? trace_hardirqs_off+0x10/0x10 [ 34.846622] ? trace_hardirqs_off+0x10/0x10 [ 34.850912] ? trace_hardirqs_off+0x10/0x10 [ 34.855207] ? dequeue_task_fair+0x490/0x490 [ 34.859586] lock_acquire+0x1d5/0x580 [ 34.863355] ? lock_acquire+0x1d5/0x580 [ 34.867298] ? rtnl_lock+0x17/0x20 [ 34.870805] ? lock_release+0xa40/0xa40 [ 34.874765] ? check_same_owner+0x320/0x320 [ 34.879062] ? try_to_wake_up+0xf9/0x15f0 [ 34.883178] ? rcu_note_context_switch+0x710/0x710 [ 34.888080] ? __might_sleep+0x95/0x190 [ 34.892028] ? rtnl_lock+0x17/0x20 [ 34.895541] __mutex_lock+0x16f/0x1a80 [ 34.899397] ? rtnl_lock+0x17/0x20 [ 34.902916] ? wait_for_completion_killable+0x63e/0x820 [ 34.908249] ? lock_downgrade+0x980/0x980 [ 34.912364] ? rtnl_lock+0x17/0x20 [ 34.915875] ? mutex_lock_io_nested+0x1900/0x1900 [ 34.920702] ? mark_held_locks+0xaf/0x100 [ 34.924819] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.929287] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.934273] ? trace_hardirqs_on+0xd/0x10 [ 34.938392] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.942858] ? wait_for_completion_killable+0x63e/0x820 [ 34.948198] ? wait_for_completion_interruptible_timeout+0x820/0x820 [ 34.954660] ? lock_downgrade+0x980/0x980 [ 34.958781] ? lock_release+0xa40/0xa40 [ 34.962726] ? __kthread_create_on_node+0x127/0x480 [ 34.967714] ? do_raw_spin_trylock+0x190/0x190 [ 34.972267] ? wake_up_q+0xe0/0xe0 [ 34.975777] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 34.981286] ? __kthread_create_on_node+0x36e/0x480 [ 34.986272] ? print_irqtrace_events+0x270/0x270 [ 34.991023] ? kthread_park+0x130/0x130 [ 34.994984] ? __lock_is_held+0xb6/0x140 [ 34.999025] mutex_lock_nested+0x16/0x20 [ 35.003062] ? mutex_lock_nested+0x16/0x20 [ 35.007267] rtnl_lock+0x17/0x20 [ 35.010603] ip_mc_drop_socket+0x88/0x230 [ 35.014722] inet_release+0x4e/0x1c0 [ 35.018427] sock_release+0x8d/0x1e0 [ 35.022113] start_sync_thread+0x2213/0x2b70 [ 35.026493] ? do_ip_vs_set_ctl+0x10f8/0x1cc0 [ 35.030958] ? ip_vs_process_message_v0+0x870/0x870 [ 35.035946] ? ip_vs_sync_conn+0x3950/0x3950 [ 35.040336] ? find_held_lock+0x35/0x1d0 [ 35.044371] ? release_sock+0x1d4/0x2a0 [ 35.048314] ? trace_hardirqs_off+0x10/0x10 [ 35.052603] ? lock_release+0xa40/0xa40 [ 35.056545] ? lock_acquire+0x1d5/0x580 [ 35.060487] ? lock_sock_nested+0xa3/0x110 [ 35.064689] ? lock_acquire+0x1d5/0x580 [ 35.068635] ? find_held_lock+0x35/0x1d0 [ 35.072843] ? __might_fault+0x110/0x1d0 [ 35.076902] ? lock_sock_nested+0x91/0x110 [ 35.081106] ? lock_release+0xa40/0xa40 [ 35.085051] ? check_same_owner+0x320/0x320 [ 35.089343] ? module_unload_free+0x5b0/0x5b0 [ 35.093810] ? __might_sleep+0x95/0x190 [ 35.097761] do_ip_vs_set_ctl+0x1139/0x1cc0 [ 35.102055] ? do_ip_vs_set_ctl+0x1139/0x1cc0 [ 35.106522] ? ip_vs_genl_dump_services+0x440/0x440 [ 35.111509] ? nf_sockopt_find.constprop.0+0x1a7/0x220 [ 35.116756] ? lock_downgrade+0x980/0x980 [ 35.120872] ? lock_release+0xa40/0xa40 [ 35.124817] ? __lock_is_held+0xb6/0x140 [ 35.128854] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 35.133668] ? wait_for_completion+0x770/0x770 [ 35.138222] ? module_unload_free+0x5b0/0x5b0 [ 35.142690] ? handle_mm_fault+0x35b/0xb10 [ 35.146899] nf_setsockopt+0x67/0xc0 [ 35.150582] ? nf_setsockopt+0x67/0xc0 [ 35.154439] ip_setsockopt+0x97/0xa0 [ 35.158121] tcp_setsockopt+0x82/0xd0 [ 35.161890] sock_common_setsockopt+0x95/0xd0 [ 35.166354] SyS_setsockopt+0x189/0x360 [ 35.170299] ? SyS_recv+0x40/0x40 [ 35.173720] ? mm_fault_error+0x2c0/0x2c0 [ 35.177843] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 35.183354] ? do_syscall_64+0xb7/0x940 [ 35.187300] ? SyS_recv+0x40/0x40 [ 35.190732] do_syscall_64+0x281/0x940 [ 35.194594] ? __do_page_fault+0xc90/0xc90 [ 35.198802] ? _raw_spin_unlock_irq+0x27/0x70 [ 35.203269] ? finish_task_switch+0x1c1/0x7e0 [ 35.207736] ? syscall_return_slowpath+0x550/0x550 [ 35.212639] ? syscall_return_slowpath+0x2ac/0x550 [ 35.217552] ? prepare_exit_to_usermode+0x350/0x350 [ 35.222542] ? retint_user+0x18/0x18 [ 35.226278] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 35.231096] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 35.236255] RIP: 0033:0x446c39 [ 35.239423] RSP: 002b:00007f6b5b1dfce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 35.247099] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446c39 [ 35.254338] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 [ 35.261576] RBP: 00000000006e29e0 R08: 0000000000000018 R09: 0000000000000000 [ 35.268815] R10: 0000000020000040 R11: 0000000000000246 R12: 0000000000000000 [ 35.276141] R13: 00007ffca18c70bf R14: 00007f6b5b1e09c0 R15: 00000000006e2b60