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 '10.128.0.38' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 23.350499] IPVS: ftp: loaded support on port[0] = 21 executing program executing program [ 23.391721] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.392269] IPVS: stopping backup sync thread 4425 ... [ 23.419238] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.420823] IPVS: stopping backup sync thread 4429 ... executing program executing program [ 23.445004] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.453954] IPVS: stopping backup sync thread 4433 ... [ 23.471670] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.472113] IPVS: stopping backup sync thread 4437 ... executing program executing program [ 23.495927] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.496459] IPVS: stopping backup sync thread 4441 ... [ 23.522420] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.522874] IPVS: stopping backup sync thread 4445 ... executing program executing program [ 23.545972] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.546484] IPVS: stopping backup sync thread 4449 ... [ 23.570881] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.571477] IPVS: stopping backup sync thread 4453 ... executing program executing program [ 23.594439] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.595202] IPVS: stopping backup sync thread 4457 ... [ 23.618831] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.619297] IPVS: stopping backup sync thread 4461 ... executing program executing program [ 23.644931] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.645479] IPVS: stopping backup sync thread 4465 ... [ 23.669543] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.678552] IPVS: stopping backup sync thread 4469 ... executing program executing program [ 23.694601] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.694936] IPVS: stopping backup sync thread 4473 ... [ 23.719207] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.720076] IPVS: stopping backup sync thread 4477 ... executing program executing program [ 23.742593] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.744073] IPVS: stopping backup sync thread 4481 ... [ 23.768913] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.769375] IPVS: stopping backup sync thread 4485 ... executing program executing program [ 23.793379] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.794304] IPVS: stopping backup sync thread 4489 ... [ 23.817788] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.819074] IPVS: stopping backup sync thread 4494 ... executing program executing program [ 23.841883] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.842395] IPVS: stopping backup sync thread 4498 ... [ 23.866960] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.867427] IPVS: stopping backup sync thread 4502 ... executing program executing program [ 23.890416] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.892283] IPVS: stopping backup sync thread 4506 ... [ 23.915128] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.915586] IPVS: stopping backup sync thread 4510 ... executing program executing program [ 23.939748] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.941577] IPVS: stopping backup sync thread 4514 ... [ 23.965277] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 23.966398] IPVS: stopping backup sync thread 4518 ... [ 23.989576] IPVS: stopping backup sync thread 4522 ... executing program executing program [ 23.989896] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 24.014294] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 24.014779] IPVS: stopping backup sync thread 4526 ... [ 24.038751] IPVS: sync thread started: state = BACKUP, mcast_ifn = sit0, syncid = 0, id = 0 [ 24.047709] IPVS: stopping backup sync thread 4530 ... [ 24.053469] [ 24.055087] ============================================ [ 24.060502] WARNING: possible recursive locking detected [ 24.065920] 4.16.0-rc7+ #368 Not tainted [ 24.069953] -------------------------------------------- [ 24.075369] syzkaller522199/4529 is trying to acquire lock: [ 24.081051] (rtnl_mutex){+.+.}, at: [<00000000922f8c06>] rtnl_lock+0x17/0x20 [ 24.088312] [ 24.088312] but task is already holding lock: [ 24.094250] (rtnl_mutex){+.+.}, at: [<00000000922f8c06>] rtnl_lock+0x17/0x20 [ 24.101504] [ 24.101504] other info that might help us debug this: [ 24.108136] Possible unsafe locking scenario: [ 24.108136] [ 24.114162] CPU0 [ 24.116713] ---- [ 24.119261] lock(rtnl_mutex); [ 24.122511] lock(rtnl_mutex); [ 24.125758] [ 24.125758] *** DEADLOCK *** [ 24.125758] [ 24.131783] May be due to missing lock nesting notation [ 24.131783] [ 24.138680] 2 locks held by syzkaller522199/4529: [ 24.143486] #0: (rtnl_mutex){+.+.}, at: [<00000000922f8c06>] rtnl_lock+0x17/0x20 [ 24.151175] #1: (ipvs->sync_mutex){+.+.}, at: [<00000000bb2216e5>] do_ip_vs_set_ctl+0x10f8/0x1cc0 [ 24.160333] [ 24.160333] stack backtrace: [ 24.164797] CPU: 1 PID: 4529 Comm: syzkaller522199 Not tainted 4.16.0-rc7+ #368 [ 24.172214] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.181536] Call Trace: [ 24.184098] dump_stack+0x194/0x24d [ 24.187694] ? arch_local_irq_restore+0x53/0x53 [ 24.192334] __lock_acquire+0xe8f/0x3e00 [ 24.196382] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 24.201545] ? _raw_spin_unlock_irq+0x27/0x70 [ 24.206013] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 24.211004] ? __lock_acquire+0x664/0x3e00 [ 24.215215] ? finish_task_switch+0x182/0x7e0 [ 24.219684] ? copy_overflow+0x20/0x20 [ 24.223549] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 24.228710] ? __schedule+0x903/0x1ec0 [ 24.232570] ? __sched_text_start+0x8/0x8 [ 24.236686] ? trace_hardirqs_off+0x10/0x10 [ 24.240981] ? trace_hardirqs_off+0x10/0x10 [ 24.245272] ? trace_hardirqs_off+0x10/0x10 [ 24.249564] ? trace_hardirqs_off+0x10/0x10 [ 24.253855] ? trace_hardirqs_off+0x10/0x10 [ 24.258148] lock_acquire+0x1d5/0x580 [ 24.261915] ? lock_acquire+0x1d5/0x580 [ 24.265863] ? rtnl_lock+0x17/0x20 [ 24.269372] ? lock_release+0xa40/0xa40 [ 24.273316] ? check_same_owner+0x320/0x320 [ 24.277611] ? __schedule+0x1ec0/0x1ec0 [ 24.281561] ? rcu_note_context_switch+0x710/0x710 [ 24.286464] ? __might_sleep+0x95/0x190 [ 24.290407] ? rtnl_lock+0x17/0x20 [ 24.293915] __mutex_lock+0x16f/0x1a80 [ 24.297771] ? rtnl_lock+0x17/0x20 [ 24.301280] ? wait_for_completion_killable+0x63e/0x820 [ 24.306615] ? lock_downgrade+0x980/0x980 [ 24.310739] ? rtnl_lock+0x17/0x20 [ 24.314249] ? mutex_lock_io_nested+0x1900/0x1900 [ 24.319063] ? mark_held_locks+0xaf/0x100 [ 24.323180] ? _raw_spin_unlock_irq+0x27/0x70 [ 24.327645] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 24.332628] ? trace_hardirqs_on+0xd/0x10 [ 24.336748] ? _raw_spin_unlock_irq+0x27/0x70 [ 24.341214] ? wait_for_completion_killable+0x63e/0x820 [ 24.346548] ? wait_for_completion_interruptible_timeout+0x820/0x820 [ 24.353013] ? lock_downgrade+0x980/0x980 [ 24.357137] ? lock_release+0xa40/0xa40 [ 24.361084] ? __kthread_create_on_node+0x127/0x480 [ 24.366070] ? do_raw_spin_trylock+0x190/0x190 [ 24.370622] ? wake_up_q+0xe0/0xe0 [ 24.374132] ? entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 24.379468] ? __kthread_create_on_node+0x36e/0x480 [ 24.384453] ? print_irqtrace_events+0x270/0x270 [ 24.389176] ? kthread_park+0x130/0x130 [ 24.393122] ? lock_release+0xa40/0xa40 [ 24.397070] ? __lock_is_held+0xb6/0x140 [ 24.401109] mutex_lock_nested+0x16/0x20 [ 24.405139] ? mutex_lock_nested+0x16/0x20 [ 24.409343] rtnl_lock+0x17/0x20 [ 24.412681] ip_mc_drop_socket+0x88/0x230 [ 24.416797] inet_release+0x4e/0x1c0 [ 24.420570] sock_release+0x8d/0x1e0 [ 24.424253] start_sync_thread+0x2213/0x2b70 [ 24.428632] ? do_ip_vs_set_ctl+0x10f8/0x1cc0 [ 24.433099] ? ip_vs_process_message_v0+0x870/0x870 [ 24.438086] ? ip_vs_sync_conn+0x3950/0x3950 [ 24.442468] ? trace_hardirqs_off+0x10/0x10 [ 24.446761] ? lock_downgrade+0x980/0x980 [ 24.450880] ? lock_release+0xa40/0xa40 [ 24.454830] ? lock_acquire+0x1d5/0x580 [ 24.458772] ? lock_acquire+0x1d5/0x580 [ 24.462715] ? find_held_lock+0x35/0x1d0 [ 24.466748] ? __might_fault+0x110/0x1d0 [ 24.470778] ? lock_release+0xa40/0xa40 [ 24.474723] ? check_same_owner+0x320/0x320 [ 24.479018] ? module_unload_free+0x5b0/0x5b0 [ 24.483486] ? __might_sleep+0x95/0x190 [ 24.487434] do_ip_vs_set_ctl+0x1139/0x1cc0 [ 24.491735] ? do_ip_vs_set_ctl+0x1139/0x1cc0 [ 24.496202] ? find_held_lock+0x35/0x1d0 [ 24.500233] ? ip_vs_genl_dump_services+0x440/0x440 [ 24.505230] ? nf_sockopt_find.constprop.0+0x1a7/0x220 [ 24.510475] ? lock_downgrade+0x980/0x980 [ 24.514619] ? __lock_is_held+0xb6/0x140 [ 24.518653] ? __mutex_unlock_slowpath+0xe9/0xac0 [ 24.523465] ? wait_for_completion+0x770/0x770 [ 24.528021] ? lock_downgrade+0x980/0x980 [ 24.532145] ? module_unload_free+0x5b0/0x5b0 [ 24.536611] ? __lock_is_held+0xb6/0x140 [ 24.540645] ? mutex_unlock+0xd/0x10 [ 24.544333] nf_setsockopt+0x67/0xc0 [ 24.548024] ? nf_setsockopt+0x67/0xc0 [ 24.551888] ip_setsockopt+0x97/0xa0 [ 24.555574] udp_setsockopt+0x45/0x80 [ 24.559347] sock_common_setsockopt+0x95/0xd0 [ 24.563812] SyS_setsockopt+0x189/0x360 [ 24.567754] ? SyS_recv+0x40/0x40 [ 24.571177] ? key_get_type_from_user.constprop.8+0xd0/0xd0 [ 24.576856] ? move_addr_to_kernel+0x60/0x60 [ 24.581233] ? do_syscall_64+0xb7/0x940 [ 24.585177] ? SyS_recv+0x40/0x40 [ 24.588601] do_syscall_64+0x281/0x940 [ 24.592455] ? __do_page_fault+0xc90/0xc90 [ 24.596661] ? _raw_spin_unlock_irq+0x27/0x70 [ 24.601124] ? finish_task_switch+0x1c1/0x7e0 [ 24.605588] ? syscall_return_slowpath+0x550/0x550 [ 24.610488] ? syscall_return_slowpath+0x2ac/0x550 [ 24.615388] ? prepare_exit_to_usermode+0x350/0x350 [ 24.620373] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 24.625710] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 24.630523] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 24.635682] RIP: 0033:0x447939 [ 24.638841] RSP: 002b:00007f8e02bc2da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 24.646535] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000447939 [ 24.653772] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000004 [ 24.661013] RBP: 00000000006e39e4 R08: 0000000000000018 R09: 0000000000000000 [ 24.668257] R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e39e0 [ 24.675499] R13: 00676e697279656b R14: 00007f8e02bc39c0 R15: 0000000000000004