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 '10.128.0.17' (ECDSA) to the list of known hosts. syzkaller login: [ 28.712189] IPVS: ftp: loaded support on port[0] = 21 [ 28.720285] IPVS: ftp: loaded support on port[0] = 21 [ 28.724709] IPVS: ftp: loaded support on port[0] = 21 [ 28.728421] IPVS: ftp: loaded support on port[0] = 21 [ 28.736101] IPVS: ftp: loaded support on port[0] = 21 [ 28.739413] IPVS: ftp: loaded support on port[0] = 21 [ 28.742474] IPVS: ftp: loaded support on port[0] = 21 [ 28.753881] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program [ 28.845768] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 28.855516] IPVS: stopping backup sync thread 4486 ... executing program executing program executing program executing program [ 28.908667] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 28.908731] IPVS: stopping backup sync thread 4492 ... [ 28.930981] IPVS: stopping backup sync thread 4498 ... [ 28.950086] IPVS: stopping backup sync thread 4502 ... executing program executing program executing program executing program executing program [ 28.963345] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 28.963506] IPVS: stopping backup sync thread 4503 ... [ 28.982190] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 28.984255] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 28.990718] IPVS: stopping backup sync thread 4510 ... [ 29.001163] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 executing program executing program executing program [ 29.005237] IPVS: stopping backup sync thread 4519 ... [ 29.013270] IPVS: stopping backup sync thread 4520 ... [ 29.024418] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 29.028314] IPVS: stopping backup sync thread 4524 ... [ 29.039092] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 29.042114] IPVS: stopping backup sync thread 4526 ... [ 29.050689] IPVS: stopping backup sync thread 4530 ... [ 29.058612] IPVS: stopping backup sync thread 4534 ... executing program executing program executing program executing program [ 29.067599] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 29.067640] IPVS: stopping backup sync thread 4539 ... [ 29.082450] [ 29.084074] ============================================ [ 29.089510] WARNING: possible recursive locking detected [ 29.094951] 4.16.0+ #2 Not tainted [ 29.098474] -------------------------------------------- [ 29.103906] syzkaller908094/4522 is trying to acquire lock: [ 29.109588] 00000000291a591c (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 29.116415] [ 29.116415] but task is already holding lock: [ 29.122362] 00000000291a591c (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 29.129190] [ 29.129190] other info that might help us debug this: [ 29.135831] Possible unsafe locking scenario: [ 29.135831] [ 29.141873] CPU0 [ 29.144428] ---- [ 29.146981] lock(rtnl_mutex); [ 29.150238] lock(rtnl_mutex); [ 29.153500] [ 29.153500] *** DEADLOCK *** [ 29.153500] [ 29.159546] May be due to missing lock nesting notation [ 29.159546] [ 29.166454] 2 locks held by syzkaller908094/4522: [ 29.171275] #0: 00000000291a591c (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 29.178556] #1: 0000000031f16e1a (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 29.187205] [ 29.187205] stack backtrace: [ 29.191680] CPU: 1 PID: 4522 Comm: syzkaller908094 Not tainted 4.16.0+ #2 [ 29.198577] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.207904] Call Trace: [ 29.210467] dump_stack+0x1b9/0x294 [ 29.214072] ? dump_stack_print_info.cold.2+0x52/0x52 [ 29.219240] ? print_lock+0xd1/0xd6 [ 29.222855] ? vprintk_func+0x81/0xe7 [ 29.226638] __lock_acquire.cold.62+0x18c/0x55b [ 29.231286] ? debug_check_no_locks_freed+0x310/0x310 [ 29.236454] ? account_kernel_stack+0x2bd/0x410 [ 29.241102] ? trace_hardirqs_on+0xd/0x10 [ 29.245225] ? put_task_stack+0x188/0x2c0 [ 29.249352] ? __lock_acquire+0x7f5/0x5140 [ 29.253568] ? copy_overflow+0x20/0x20 [ 29.257436] ? debug_check_no_locks_freed+0x310/0x310 [ 29.262603] ? __schedule+0x809/0x1e30 [ 29.266467] ? graph_lock+0x170/0x170 [ 29.270243] ? kasan_check_read+0x11/0x20 [ 29.274369] ? graph_lock+0x170/0x170 [ 29.278149] ? graph_lock+0x170/0x170 [ 29.281933] lock_acquire+0x1dc/0x520 [ 29.285721] ? rtnl_lock+0x17/0x20 [ 29.289247] ? lock_release+0xa10/0xa10 [ 29.293206] ? check_same_owner+0x320/0x320 [ 29.297502] ? schedule+0xef/0x430 [ 29.301024] ? rcu_note_context_switch+0x710/0x710 [ 29.305934] ? __schedule+0x1e30/0x1e30 [ 29.309895] ? __might_sleep+0x95/0x190 [ 29.313861] ? rtnl_lock+0x17/0x20 [ 29.317392] __mutex_lock+0x16d/0x17f0 [ 29.321258] ? rtnl_lock+0x17/0x20 [ 29.324778] ? rtnl_lock+0x17/0x20 [ 29.328303] ? mutex_trylock+0x2a0/0x2a0 [ 29.332353] ? mark_held_locks+0xc9/0x160 [ 29.336484] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 29.341053] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.345529] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 29.350531] ? trace_hardirqs_on+0xd/0x10 [ 29.354657] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.359126] ? wait_for_completion_killable+0x56c/0x960 [ 29.364471] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 29.370939] ? lock_downgrade+0x8e0/0x8e0 [ 29.375063] ? kasan_check_read+0x11/0x20 [ 29.379197] ? do_raw_spin_unlock+0x9e/0x2e0 [ 29.383600] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 29.388159] ? wake_up_q+0x100/0x100 [ 29.391849] ? kasan_check_write+0x14/0x20 [ 29.396060] ? do_raw_spin_lock+0xc1/0x200 [ 29.400276] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.405791] ? __kthread_create_on_node+0x34f/0x4c0 [ 29.410792] ? __kthread_parkme+0x280/0x280 [ 29.415095] ? kasan_check_read+0x11/0x20 [ 29.419222] ? do_raw_spin_unlock+0x9e/0x2e0 [ 29.423604] ? __lock_is_held+0xb5/0x140 [ 29.427639] mutex_lock_nested+0x16/0x20 [ 29.431674] ? mutex_lock_nested+0x16/0x20 [ 29.435892] rtnl_lock+0x17/0x20 [ 29.439252] ip_mc_drop_socket+0x8f/0x270 [ 29.443382] inet_release+0x4e/0x1f0 [ 29.447083] sock_release+0x96/0x1b0 [ 29.450781] start_sync_thread+0xdc3/0x2d40 [ 29.455080] ? ip_vs_process_message+0xa0a/0xa0a [ 29.459814] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 29.464200] ? graph_lock+0x170/0x170 [ 29.467982] ? lock_downgrade+0x8e0/0x8e0 [ 29.472106] ? kasan_check_read+0x11/0x20 [ 29.476232] ? do_raw_spin_unlock+0x9e/0x2e0 [ 29.480616] ? find_held_lock+0x36/0x1c0 [ 29.484655] ? lock_downgrade+0x8e0/0x8e0 [ 29.488778] ? __release_sock+0x3a0/0x3a0 [ 29.492902] ? lock_release+0xa10/0xa10 [ 29.497035] ? check_same_owner+0x320/0x320 [ 29.501339] ? module_unload_free+0x5b0/0x5b0 [ 29.505823] do_ip_vs_set_ctl+0x59c/0x1d30 [ 29.510043] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 29.514527] ? lock_downgrade+0x8e0/0x8e0 [ 29.518659] ? lock_downgrade+0x8e0/0x8e0 [ 29.522784] ? kasan_check_read+0x11/0x20 [ 29.526907] ? rcu_is_watching+0x85/0x140 [ 29.531036] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 29.536203] ? kasan_check_write+0x14/0x20 [ 29.540414] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 29.545322] ? wait_for_completion+0x870/0x870 [ 29.549883] ? module_unload_free+0x5b0/0x5b0 [ 29.554358] ? expand_files.part.8+0x9a0/0x9a0 [ 29.558917] ? vm_insert_mixed_mkwrite+0x40/0x40 [ 29.564627] ? rcu_is_watching+0x85/0x140 [ 29.568753] ? graph_lock+0x170/0x170 [ 29.572534] nf_setsockopt+0x7d/0xd0 [ 29.576234] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 29.580703] ? nf_setsockopt+0x7d/0xd0 [ 29.584568] ip_setsockopt+0xd8/0xf0 [ 29.588256] udp_setsockopt+0x62/0xa0 [ 29.592038] ipv6_setsockopt+0x149/0x170 [ 29.596084] udpv6_setsockopt+0x62/0xa0 [ 29.600041] sock_common_setsockopt+0x9a/0xe0 [ 29.604517] __sys_setsockopt+0x1bd/0x390 [ 29.608641] ? kernel_accept+0x310/0x310 [ 29.612684] ? mm_fault_error+0x380/0x380 [ 29.616816] SyS_setsockopt+0x34/0x50 [ 29.620590] ? SyS_recv+0x40/0x40 [ 29.624025] do_syscall_64+0x29e/0x9d0 [ 29.627892] ? vmalloc_sync_all+0x30/0x30 [ 29.632020] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.636495] ? finish_task_switch+0x1ca/0x810 [ 29.640976] ? syscall_return_slowpath+0x5c0/0x5c0 [ 29.645891] ? syscall_return_slowpath+0x30f/0x5c0 [ 29.650804] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.656327] ? retint_user+0x18/0x18 [ 29.660031] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.664854] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 29.670033] RIP: 0033:0x446bb9 [ 29.673208] RSP: 002b:00007f86f7833db8 EFLAGS: 00000293 ORIG_RAX: 0000000000000036 [ 29.680891] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446bb9 [ 29.688140] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000005 [ 29.695386] RBP: 00000000006e29e0 R08: 0000000000000018 R09: 0000000000000000 [ 29.702633] R10: 0000000020000100 R11: 0000000000000293 R12: 0000000000000000 [ 29.709886] R13: 00007fffba6a4a4f R14: 00007f86f78349c0 R15: 00000000006e2b60