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 '10.128.0.34' (ECDSA) to the list of known hosts. syzkaller login: [ 30.698730] IPVS: ftp: loaded support on port[0] = 21 [ 30.700967] IPVS: ftp: loaded support on port[0] = 21 [ 30.710207] IPVS: ftp: loaded support on port[0] = 21 [ 30.716881] IPVS: ftp: loaded support on port[0] = 21 [ 30.718668] IPVS: ftp: loaded support on port[0] = 21 [ 30.722915] IPVS: ftp: loaded support on port[0] = 21 [ 30.730243] IPVS: ftp: loaded support on port[0] = 21 [ 30.733597] 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 executing program executing program [ 30.900649] IPVS: stopping backup sync thread 4495 ... [ 30.906289] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.906756] IPVS: stopping backup sync thread 4497 ... [ 30.921140] IPVS: stopping backup sync thread 4501 ... [ 30.929934] IPVS: stopping backup sync thread 4502 ... executing program [ 30.952960] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.955188] IPVS: stopping backup sync thread 4513 ... [ 30.966836] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.967901] IPVS: stopping backup sync thread 4520 ... [ 30.975969] IPVS: stopping backup sync thread 4517 ... [ 30.981489] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 30.989803] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 executing program [ 30.995257] IPVS: stopping backup sync thread 4521 ... [ 31.005312] IPVS: stopping backup sync thread 4522 ... [ 31.009957] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.014974] IPVS: stopping backup sync thread 4529 ... [ 31.021992] IPVS: stopping backup sync thread 4526 ... [ 31.022714] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.028373] [ 31.042647] ============================================ [ 31.048079] WARNING: possible recursive locking detected [ 31.053503] 4.16.0+ #3 Not tainted [ 31.057016] -------------------------------------------- [ 31.062450] syzkaller377052/4511 is trying to acquire lock: [ 31.068130] 00000000e6295795 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 31.074955] [ 31.074955] but task is already holding lock: [ 31.080901] 00000000e6295795 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 31.087730] [ 31.087730] other info that might help us debug this: [ 31.094372] Possible unsafe locking scenario: [ 31.094372] [ 31.100399] CPU0 [ 31.102954] ---- [ 31.105512] lock(rtnl_mutex); [ 31.108763] lock(rtnl_mutex); [ 31.112024] [ 31.112024] *** DEADLOCK *** [ 31.112024] [ 31.118059] May be due to missing lock nesting notation [ 31.118059] [ 31.124959] 2 locks held by syzkaller377052/4511: [ 31.129770] #0: 00000000e6295795 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 31.137034] #1: 00000000c2d656ab (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 31.145682] [ 31.145682] stack backtrace: [ 31.150154] CPU: 0 PID: 4511 Comm: syzkaller377052 Not tainted 4.16.0+ #3 [ 31.157057] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.166391] Call Trace: [ 31.168958] dump_stack+0x1b9/0x294 [ 31.172559] ? dump_stack_print_info.cold.2+0x52/0x52 [ 31.177726] ? print_lock+0xd1/0xd6 [ 31.181327] ? vprintk_func+0x81/0xe7 [ 31.185105] __lock_acquire.cold.62+0x18c/0x55b [ 31.189751] ? debug_check_no_locks_freed+0x310/0x310 [ 31.194915] ? account_kernel_stack+0x2bd/0x410 [ 31.199565] ? trace_hardirqs_on+0xd/0x10 [ 31.203687] ? put_task_stack+0x188/0x2c0 [ 31.207811] ? __lock_acquire+0x7f5/0x5140 [ 31.212028] ? copy_overflow+0x20/0x20 [ 31.215893] ? debug_check_no_locks_freed+0x310/0x310 [ 31.221066] ? __schedule+0x809/0x1e30 [ 31.224931] ? graph_lock+0x170/0x170 [ 31.228706] ? kasan_check_read+0x11/0x20 [ 31.232828] ? graph_lock+0x170/0x170 [ 31.236600] ? graph_lock+0x170/0x170 [ 31.240377] lock_acquire+0x1dc/0x520 [ 31.244155] ? rtnl_lock+0x17/0x20 [ 31.247673] ? lock_release+0xa10/0xa10 [ 31.251624] ? check_same_owner+0x320/0x320 [ 31.255935] ? schedule+0xef/0x430 [ 31.259457] ? rcu_note_context_switch+0x710/0x710 [ 31.264360] ? __schedule+0x1e30/0x1e30 [ 31.268311] ? __might_sleep+0x95/0x190 [ 31.272259] ? rtnl_lock+0x17/0x20 [ 31.275772] __mutex_lock+0x16d/0x17f0 [ 31.279639] ? rtnl_lock+0x17/0x20 [ 31.283158] ? rtnl_lock+0x17/0x20 [ 31.286675] ? mutex_trylock+0x2a0/0x2a0 [ 31.290713] ? mark_held_locks+0xc9/0x160 [ 31.294834] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 31.299392] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.303860] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.308849] ? trace_hardirqs_on+0xd/0x10 [ 31.313040] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.317518] ? wait_for_completion_killable+0x56c/0x960 [ 31.322858] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 31.329673] ? lock_downgrade+0x8e0/0x8e0 [ 31.333798] ? kasan_check_read+0x11/0x20 [ 31.337928] ? do_raw_spin_unlock+0x9e/0x2e0 [ 31.342312] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 31.346871] ? wake_up_q+0x100/0x100 [ 31.350563] ? kasan_check_write+0x14/0x20 [ 31.354774] ? do_raw_spin_lock+0xc1/0x200 [ 31.358987] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.364502] ? __kthread_create_on_node+0x34f/0x4c0 [ 31.369492] ? __kthread_parkme+0x280/0x280 [ 31.373802] ? kasan_check_read+0x11/0x20 [ 31.377946] ? do_raw_spin_unlock+0x9e/0x2e0 [ 31.382331] ? __lock_is_held+0xb5/0x140 [ 31.386375] mutex_lock_nested+0x16/0x20 [ 31.390414] ? mutex_lock_nested+0x16/0x20 [ 31.394623] rtnl_lock+0x17/0x20 [ 31.397969] ip_mc_drop_socket+0x8f/0x270 [ 31.402093] inet_release+0x4e/0x1f0 [ 31.405779] sock_release+0x96/0x1b0 [ 31.409472] start_sync_thread+0xdc3/0x2d40 [ 31.413768] ? __lock_acquire+0x7f5/0x5140 [ 31.417978] ? ip_vs_process_message+0xa0a/0xa0a [ 31.422711] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 31.427104] ? graph_lock+0x170/0x170 [ 31.430883] ? lock_downgrade+0x8e0/0x8e0 [ 31.435021] ? lock_downgrade+0x8e0/0x8e0 [ 31.439170] ? kasan_check_read+0x11/0x20 [ 31.443309] ? do_raw_spin_unlock+0x9e/0x2e0 [ 31.447699] ? __local_bh_enable_ip+0x161/0x230 [ 31.452351] ? find_held_lock+0x36/0x1c0 [ 31.456392] ? lock_downgrade+0x8e0/0x8e0 [ 31.460515] ? lock_release+0xa10/0xa10 [ 31.464467] ? check_same_owner+0x320/0x320 [ 31.468768] ? module_unload_free+0x5b0/0x5b0 [ 31.473250] do_ip_vs_set_ctl+0x59c/0x1d30 [ 31.477463] ? find_held_lock+0x36/0x1c0 [ 31.481503] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 31.485982] ? lock_downgrade+0x8e0/0x8e0 [ 31.490203] ? kasan_check_read+0x11/0x20 [ 31.494335] ? rcu_is_watching+0x85/0x140 [ 31.498458] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 31.503623] ? kasan_check_write+0x14/0x20 [ 31.507846] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 31.512754] ? wait_for_completion+0x870/0x870 [ 31.517315] ? module_unload_free+0x5b0/0x5b0 [ 31.521788] ? __fget+0x40c/0x650 [ 31.525221] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.530736] ? mutex_unlock+0xd/0x10 [ 31.534426] nf_setsockopt+0x7d/0xd0 [ 31.538117] ? nf_setsockopt+0x7d/0xd0 [ 31.541981] ip_setsockopt+0xd8/0xf0 [ 31.545671] tcp_setsockopt+0x93/0xe0 [ 31.549451] sock_common_setsockopt+0x9a/0xe0 [ 31.553924] __sys_setsockopt+0x1bd/0x390 [ 31.558056] ? kernel_accept+0x310/0x310 [ 31.562100] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 31.567623] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 31.572444] SyS_setsockopt+0x34/0x50 [ 31.576224] ? SyS_recv+0x40/0x40 [ 31.579653] do_syscall_64+0x29e/0x9d0 [ 31.583514] ? vmalloc_sync_all+0x30/0x30 [ 31.587636] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.592808] ? finish_task_switch+0x1ca/0x810 [ 31.597283] ? syscall_return_slowpath+0x5c0/0x5c0 [ 31.602191] ? syscall_return_slowpath+0x30f/0x5c0 [ 31.607100] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 31.612439] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.617258] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 31.622421] RIP: 0033:0x446ab9 [ 31.625583] RSP: 002b:00007f34a9198da8 EFLAGS: 00000293 ORIG_RAX: 0000000000000036 [ 31.633270] RAX: ffffffffffffffda RBX: 00000000006e29e4 RCX: 0000000000446ab9 [ 31.640520] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 [ 31.647764] RBP: 0000000000000000 R08: 0000000000000018 R09: 0000000000000000 [ 31.655009] R10: 0000000020000080 R11: 0000000000000293 R12: 00000000006e29e0 [ 31.662269] R13: 7475612f7665642f R14: 00007f34a91999c0 R15: 00000000006e2b60