[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.262561] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.779103] random: sshd: uninitialized urandom read (32 bytes read) [ 24.304590] random: sshd: uninitialized urandom read (32 bytes read) [ 25.108397] random: sshd: uninitialized urandom read (32 bytes read) [ 27.072635] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.13' (ECDSA) to the list of known hosts. [ 32.869497] random: sshd: uninitialized urandom read (32 bytes read) 2018/04/24 19:10:05 parsed 1 programs 2018/04/24 19:10:05 executed programs: 0 [ 33.361542] IPVS: ftp: loaded support on port[0] = 21 [ 33.372185] IPVS: ftp: loaded support on port[0] = 21 [ 33.377300] IPVS: ftp: loaded support on port[0] = 21 [ 33.386912] IPVS: ftp: loaded support on port[0] = 21 [ 33.388060] IPVS: ftp: loaded support on port[0] = 21 [ 33.414930] IPVS: ftp: loaded support on port[0] = 21 [ 33.429980] IPVS: ftp: loaded support on port[0] = 21 [ 33.444302] IPVS: ftp: loaded support on port[0] = 21 [ 33.648053] IPVS: stopping backup sync thread 4578 ... [ 33.658745] IPVS: stopping backup sync thread 4580 ... [ 33.670375] IPVS: stopping backup sync thread 4585 ... [ 33.711498] IPVS: stopping backup sync thread 4586 ... [ 33.721746] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 33.732765] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 33.753060] IPVS: stopping backup sync thread 4607 ... [ 33.753108] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 33.778935] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 33.779503] IPVS: stopping backup sync thread 4610 ... [ 33.795131] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 33.798292] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 33.804119] IPVS: stopping backup sync thread 4617 ... [ 33.812099] IPVS: stopping backup sync thread 4616 ... [ 33.818853] [ 33.824209] ============================================ [ 33.829646] WARNING: possible recursive locking detected [ 33.835087] 4.17.0-rc2+ #14 Not tainted [ 33.839049] -------------------------------------------- [ 33.844494] syz-executor5/4576 is trying to acquire lock: [ 33.850022] (ptrval) (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 33.856911] [ 33.856911] but task is already holding lock: [ 33.862880] (ptrval) (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 33.869718] [ 33.869718] other info that might help us debug this: [ 33.876376] Possible unsafe locking scenario: [ 33.876376] [ 33.882418] CPU0 [ 33.884977] ---- [ 33.887535] lock(rtnl_mutex); [ 33.890791] lock(rtnl_mutex); [ 33.894050] [ 33.894050] *** DEADLOCK *** [ 33.894050] [ 33.900091] May be due to missing lock nesting notation [ 33.900091] [ 33.907005] 2 locks held by syz-executor5/4576: [ 33.911657] #0: (ptrval) (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 33.918929] #1: (ptrval) (ipvs->sync_mutex){+.+.}, at: do_ip_vs_set_ctl+0x562/0x1d30 [ 33.927595] [ 33.927595] stack backtrace: [ 33.932084] CPU: 1 PID: 4576 Comm: syz-executor5 Not tainted 4.17.0-rc2+ #14 [ 33.939256] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.948587] Call Trace: [ 33.951170] dump_stack+0x1b9/0x294 [ 33.954785] ? dump_stack_print_info.cold.2+0x52/0x52 [ 33.959957] ? print_lock+0xd1/0xd6 [ 33.963571] ? vprintk_func+0x81/0xe7 [ 33.967352] __lock_acquire.cold.62+0x18c/0x55b [ 33.972014] ? debug_check_no_locks_freed+0x310/0x310 [ 33.977194] ? account_kernel_stack+0x2bd/0x410 [ 33.981847] ? trace_hardirqs_on+0xd/0x10 [ 33.985977] ? put_task_stack+0x188/0x2c0 [ 33.990114] ? __lock_acquire+0x7f5/0x5140 [ 33.994338] ? preempt_notifier_register+0x1e0/0x1e0 [ 33.999432] ? __schedule+0x809/0x1e30 [ 34.003303] ? graph_lock+0x170/0x170 [ 34.007089] ? graph_lock+0x170/0x170 [ 34.010869] ? resched_curr+0x10f/0x190 [ 34.014823] ? graph_lock+0x170/0x170 [ 34.018604] ? graph_lock+0x170/0x170 [ 34.022404] lock_acquire+0x1dc/0x520 [ 34.026191] ? rtnl_lock+0x17/0x20 [ 34.029721] ? lock_release+0xa10/0xa10 [ 34.033693] ? check_same_owner+0x320/0x320 [ 34.037995] ? schedule+0xef/0x430 [ 34.041523] ? rcu_note_context_switch+0x710/0x710 [ 34.046436] ? __schedule+0x1e30/0x1e30 [ 34.050393] ? __might_sleep+0x95/0x190 [ 34.054359] ? rtnl_lock+0x17/0x20 [ 34.057885] __mutex_lock+0x16d/0x17f0 [ 34.061755] ? rtnl_lock+0x17/0x20 [ 34.065276] ? rtnl_lock+0x17/0x20 [ 34.068800] ? mutex_trylock+0x2a0/0x2a0 [ 34.072853] ? mark_held_locks+0xc9/0x160 [ 34.076983] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 34.081549] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.086036] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.091070] ? trace_hardirqs_on+0xd/0x10 [ 34.095214] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.099713] ? wait_for_completion_killable+0x56c/0x960 [ 34.105068] ? wait_for_completion_interruptible_timeout+0x960/0x960 [ 34.111546] ? lock_downgrade+0x8e0/0x8e0 [ 34.115686] ? kasan_check_read+0x11/0x20 [ 34.119817] ? do_raw_spin_unlock+0x9e/0x2e0 [ 34.124206] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 34.128769] ? wake_up_q+0x100/0x100 [ 34.132474] ? kasan_check_write+0x14/0x20 [ 34.136694] ? do_raw_spin_lock+0xc1/0x200 [ 34.140928] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 34.146450] ? __kthread_create_on_node+0x34f/0x4c0 [ 34.151473] ? __kthread_parkme+0x280/0x280 [ 34.155784] ? kasan_check_read+0x11/0x20 [ 34.159915] ? do_raw_spin_unlock+0x9e/0x2e0 [ 34.164303] ? __lock_is_held+0xb5/0x140 [ 34.168350] mutex_lock_nested+0x16/0x20 [ 34.172411] ? mutex_lock_nested+0x16/0x20 [ 34.176629] rtnl_lock+0x17/0x20 [ 34.179986] ip_mc_drop_socket+0x8f/0x270 [ 34.184135] inet_release+0x4e/0x1f0 [ 34.187842] sock_release+0x96/0x1b0 [ 34.191548] start_sync_thread+0xdc3/0x2d40 [ 34.195847] ? ip_vs_process_message+0xa0a/0xa0a [ 34.201138] ? ip_vs_sync_conn+0x33a0/0x33a0 [ 34.205529] ? graph_lock+0x170/0x170 [ 34.209311] ? lock_downgrade+0x8e0/0x8e0 [ 34.213452] ? lock_downgrade+0x8e0/0x8e0 [ 34.217595] ? kasan_check_read+0x11/0x20 [ 34.221734] ? do_raw_spin_unlock+0x9e/0x2e0 [ 34.226142] ? __local_bh_enable_ip+0x161/0x230 [ 34.230793] ? find_held_lock+0x36/0x1c0 [ 34.234857] ? lock_downgrade+0x8e0/0x8e0 [ 34.238998] ? lock_release+0xa10/0xa10 [ 34.242961] ? check_same_owner+0x320/0x320 [ 34.247267] ? module_unload_free+0x5b0/0x5b0 [ 34.251752] do_ip_vs_set_ctl+0x59c/0x1d30 [ 34.255972] ? find_held_lock+0x36/0x1c0 [ 34.260036] ? ip_vs_genl_set_cmd+0xe80/0xe80 [ 34.264525] ? lock_downgrade+0x8e0/0x8e0 [ 34.268669] ? kasan_check_read+0x11/0x20 [ 34.272816] ? rcu_is_watching+0x85/0x140 [ 34.276955] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 34.282133] ? kasan_check_write+0x14/0x20 [ 34.286362] ? __mutex_unlock_slowpath+0x180/0x8a0 [ 34.291285] ? wait_for_completion+0x870/0x870 [ 34.295863] ? module_unload_free+0x5b0/0x5b0 [ 34.300344] ? kasan_check_read+0x11/0x20 [ 34.304473] ? __lock_is_held+0xb5/0x140 [ 34.308521] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 34.313715] ? mutex_unlock+0xd/0x10 [ 34.317423] nf_setsockopt+0x7d/0xd0 [ 34.321123] ? nf_setsockopt+0x7d/0xd0 [ 34.324997] ip_setsockopt+0xd8/0xf0 [ 34.328710] tcp_setsockopt+0x93/0xe0 [ 34.332492] sock_common_setsockopt+0x9a/0xe0 [ 34.336968] __sys_setsockopt+0x1bd/0x390 [ 34.341096] ? kernel_accept+0x310/0x310 [ 34.345145] ? do_futex+0x27d0/0x27d0 [ 34.348935] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 34.353763] __x64_sys_setsockopt+0xbe/0x150 [ 34.358155] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.363153] do_syscall_64+0x1b1/0x800 [ 34.367043] ? syscall_return_slowpath+0x5c0/0x5c0 [ 34.371963] ? syscall_return_slowpath+0x30f/0x5c0 [ 34.376874] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 34.382227] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.387059] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.392225] RIP: 0033:0x455389 [ 34.395392] RSP: 002b:00007fe8d48c6c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 [ 34.403083] RAX: ffffffffffffffda RBX: 00007fe8d48c76d4 RCX: 0000000000455389 [ 34.410344] RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000004 [ 34.417597] RBP: 000000000072bea0 R08: 0000000000000018 R09: 0000000000000000 [ 34.424855] R10: 0000000020000040 R11: 0000000000000246 R12: 00000000ffffffff [ 34.432103] R13: 0000000000000529 R14: 00000000006fac78 R15: 0000000000000000 [ 34.550249] IPVS: stopping backup sync thread 4604 ... [ 34.570989] IPVS: stopping backup sync thread 4603 ...