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 '10.128.0.54' (ECDSA) to the list of known hosts. syzkaller login: [ 51.551696] IPVS: ftp: loaded support on port[0] = 21 [ 51.553532] IPVS: ftp: loaded support on port[0] = 21 [ 51.561156] IPVS: ftp: loaded support on port[0] = 21 [ 51.565667] IPVS: ftp: loaded support on port[0] = 21 [ 51.570936] IPVS: ftp: loaded support on port[0] = 21 [ 51.578424] IPVS: ftp: loaded support on port[0] = 21 [ 51.580203] IPVS: ftp: loaded support on port[0] = 21 [ 51.585180] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 51.683872] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.690460] IPVS: stopping backup sync thread 4478 ... [ 51.697912] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.701123] IPVS: stopping backup sync thread 4479 ... [ 51.726987] IPVS: stopping backup sync thread 4484 ... executing program executing program executing program executing program [ 51.748644] IPVS: stopping backup sync thread 4490 ... [ 51.748779] IPVS: stopping backup sync thread 4494 ... [ 51.755411] IPVS: stopping backup sync thread 4499 ... [ 51.763673] IPVS: stopping backup sync thread 4500 ... [ 51.771668] IPVS: stopping backup sync thread 4504 ... [ 51.777424] IPVS: stopping backup sync thread 4506 ... [ 51.777908] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.784526] IPVS: stopping backup sync thread 4510 ... executing program executing program executing program executing program executing program executing program executing program [ 51.797095] IPVS: stopping backup sync thread 4512 ... [ 51.804202] IPVS: stopping backup sync thread 4513 ... [ 51.804259] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.816360] IPVS: stopping backup sync thread 4522 ... [ 51.822512] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.827432] IPVS: stopping backup sync thread 4523 ... [ 51.835563] IPVS: stopping backup sync thread 4528 ... executing program executing program [ 51.844250] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.848570] IPVS: stopping backup sync thread 4531 ... [ 51.859473] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.859559] IPVS: stopping backup sync thread 4535 ... [ 51.870717] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.874306] IPVS: stopping backup sync thread 4539 ... [ 51.883650] IPVS: stopping backup sync thread 4541 ... executing program [ 51.890681] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.893738] IPVS: stopping backup sync thread 4544 ... [ 51.901538] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 3, id = 0 [ 51.906919] [ 51.916483] ============================================ [ 51.921908] WARNING: possible recursive locking detected [ 51.927331] 4.16.0+ #8 Not tainted [ 51.930843] -------------------------------------------- [ 51.936280] syzkaller932845/4536 is trying to acquire lock: [ 51.941972] 000000001e96ebee (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 51.948802] [ 51.948802] but task is already holding lock: [ 51.954745] 000000001e96ebee (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 51.961568] [ 51.961568] other info that might help us debug this: [ 51.968225] Possible unsafe locking scenario: [ 51.968225] [ 51.974264] CPU0 [ 51.976819] ---- [ 51.979373] lock(rtnl_mutex); [ 51.982627] lock(rtnl_mutex); [ 51.985891] [ 51.985891] *** DEADLOCK *** [ 51.985891] [ 51.991926] May be due to missing lock nesting notation [ 51.991926] [ 51.998840] 2 locks held by syzkaller932845/4536: [ 52.003663] #0: 000000001e96ebee (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 52.010939] #1: 000000009ed9b9e3 (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 52.019602] [ 52.019602] stack backtrace: [ 52.024088] CPU: 0 PID: 4536 Comm: syzkaller932845 Not tainted 4.16.0+ #8 [ 52.030994] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.040332] Call Trace: [ 52.042923] dump_stack+0x1b9/0x294 [ 52.046529] ? dump_stack_print_info.cold.2+0x52/0x52 [ 52.051705] ? print_lock+0xd1/0xd6 [ 52.055316] ? vprintk_func+0x81/0xe7 [ 52.059113] __lock_acquire.cold.62+0x18c/0x55b [ 52.063761] ? debug_check_no_locks_freed+0x310/0x310 [ 52.068931] ? _raw_spin_unlock_irq+0x27/0x70 [ 52.073492] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 52.078485] ? __lock_acquire+0x7f5/0x5140 [ 52.082710] ? copy_overflow+0x20/0x20 [ 52.086576] ? debug_check_no_locks_freed+0x310/0x310 [ 52.091755] ? __schedule+0x809/0x1e30 [ 52.095618] ? graph_lock+0x170/0x170 [ 52.099394] ? graph_lock+0x170/0x170 [ 52.103449] ? rcu_is_watching+0x85/0x140 [ 52.107585] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 52.112751] ? graph_lock+0x170/0x170 [ 52.116526] ? graph_lock+0x170/0x170 [ 52.120304] lock_acquire+0x1dc/0x520 [ 52.124098] ? rtnl_lock+0x17/0x20 [ 52.127613] ? lock_release+0xa10/0xa10 [ 52.131583] ? check_same_owner+0x320/0x320 [ 52.135883] ? schedule+0xef/0x430 [ 52.139409] ? rcu_note_context_switch+0x710/0x710 [ 52.144317] ? __schedule+0x1e30/0x1e30 [ 52.148270] ? __might_sleep+0x95/0x190 [ 52.152225] ? rtnl_lock+0x17/0x20 [ 52.155741] __mutex_lock+0x16d/0x17f0 [ 52.159615] ? rtnl_lock+0x17/0x20 [ 52.163131] ? rtnl_lock+0x17/0x20 [ 52.166658] ? mutex_trylock+0x2a0/0x2a0 [ 52.170700] ? mark_held_locks+0xc9/0x160 [ 52.174825] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 52.179384] ? _raw_spin_unlock_irq+0x27/0x70 [ 52.183858] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 52.188864] ? trace_hardirqs_on+0xd/0x10 [ 52.192988] ? _raw_spin_unlock_irq+0x27/0x70 [ 52.197473] ? wait_for_completion_killable+0x56c/0x960 [ 52.202816] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 52.209286] ? lock_downgrade+0x8e0/0x8e0 [ 52.213412] ? kasan_check_read+0x11/0x20 [ 52.217538] ? do_raw_spin_unlock+0x9e/0x2e0 [ 52.221923] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 52.226498] ? wake_up_q+0x100/0x100 [ 52.230195] ? kasan_check_write+0x14/0x20 [ 52.234410] ? do_raw_spin_lock+0xc1/0x200 [ 52.238621] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 52.244139] ? __kthread_create_on_node+0x34f/0x4c0 [ 52.249142] ? __kthread_parkme+0x280/0x280 [ 52.253461] ? kasan_check_read+0x11/0x20 [ 52.257605] ? do_raw_spin_unlock+0x9e/0x2e0 [ 52.262010] ? __lock_is_held+0xb5/0x140 [ 52.266063] mutex_lock_nested+0x16/0x20 [ 52.270119] ? mutex_lock_nested+0x16/0x20 [ 52.274343] rtnl_lock+0x17/0x20 [ 52.277701] ip_mc_drop_socket+0x8f/0x270 [ 52.281842] inet_release+0x4e/0x1f0 [ 52.285550] sock_release+0x96/0x1b0 [ 52.289257] start_sync_thread+0xdc3/0x2d40 [ 52.293571] ? ip_vs_process_message+0xa0a/0xa0a [ 52.298321] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 52.302722] ? graph_lock+0x170/0x170 [ 52.306508] ? lock_downgrade+0x8e0/0x8e0 [ 52.310645] ? kasan_check_read+0x11/0x20 [ 52.314780] ? do_raw_spin_unlock+0x9e/0x2e0 [ 52.319166] ? find_held_lock+0x36/0x1c0 [ 52.323206] ? lock_downgrade+0x8e0/0x8e0 [ 52.327329] ? __release_sock+0x3a0/0x3a0 [ 52.331450] ? lock_release+0xa10/0xa10 [ 52.335401] ? check_same_owner+0x320/0x320 [ 52.339698] ? module_unload_free+0x5b0/0x5b0 [ 52.344174] do_ip_vs_set_ctl+0x59c/0x1d30 [ 52.348388] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 52.352868] ? lock_downgrade+0x8e0/0x8e0 [ 52.356994] ? kasan_check_read+0x11/0x20 [ 52.361119] ? rcu_is_watching+0x85/0x140 [ 52.365243] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 52.370411] ? kasan_check_write+0x14/0x20 [ 52.374624] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 52.379530] ? wait_for_completion+0x870/0x870 [ 52.384110] ? module_unload_free+0x5b0/0x5b0 [ 52.388579] ? find_held_lock+0x36/0x1c0 [ 52.392621] nf_setsockopt+0x7d/0xd0 [ 52.396313] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 52.400790] ? nf_setsockopt+0x7d/0xd0 [ 52.404663] ip_setsockopt+0xd8/0xf0 [ 52.408362] raw_setsockopt+0xe2/0x100 [ 52.412234] sock_common_setsockopt+0x9a/0xe0 [ 52.416715] __sys_setsockopt+0x1bd/0x390 [ 52.420841] ? kernel_accept+0x310/0x310 [ 52.424885] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 52.430409] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 52.435254] SyS_setsockopt+0x34/0x50 [ 52.439048] ? SyS_recv+0x40/0x40 [ 52.442487] do_syscall_64+0x29e/0x9d0 [ 52.446363] ? vmalloc_sync_all+0x30/0x30 [ 52.450490] ? kasan_check_write+0x14/0x20 [ 52.454701] ? syscall_return_slowpath+0x5c0/0x5c0 [ 52.459620] ? syscall_return_slowpath+0x30f/0x5c0 [ 52.464529] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 52.469872] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 52.474693] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 52.479872] RIP: 0033:0x446b29 [ 52.483040] RSP: 002b:00007f946de8edb8 EFLAGS: 00000297 ORIG_RAX: 0000000000000036 [ 52.490748] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446b29 [ 52.497997] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 [ 52.505249] RBP: 00000000006e29e0 R08: 0000000000000018 R09: 0000000000000000 [ 52.512501] R10: 0000000020000040 R11: 0000000000000297 R12: 0000000000000000 [ 52.519747] R13: 00007ffc73977c0f R14: 00007f946de8f9c0 R15: 00000000006e2b60