[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.657672] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.910990] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 24.372317] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 25.414383] random: sshd: uninitialized urandom read (32 bytes read, 116 bits of entropy available) [ 25.570743] random: sshd: uninitialized urandom read (32 bytes read, 119 bits of entropy available) Warning: Permanently added '10.128.10.28' (ECDSA) to the list of known hosts. [ 31.021277] random: sshd: uninitialized urandom read (32 bytes read, 122 bits of entropy available) 2018/04/25 20:29:24 parsed 1 programs 2018/04/25 20:29:24 executed programs: 0 [ 31.470338] IPVS: Creating netns size=2552 id=1 [ 31.552363] IPVS: Creating netns size=2552 id=2 [ 31.565629] IPVS: stopping backup sync thread 3879 ... [ 31.572739] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.592530] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.622650] IPVS: stopping backup sync thread 3881 ... [ 31.630240] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.651360] IPVS: Creating netns size=2552 id=3 [ 31.662451] IPVS: stopping backup sync thread 3889 ... [ 31.667961] IPVS: stopping backup sync thread 3895 ... [ 31.686590] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.697560] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.718481] IPVS: stopping backup sync thread 3901 ... [ 31.735780] IPVS: stopping backup sync thread 3902 ... [ 31.742616] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.746214] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.767897] IPVS: stopping backup sync thread 3911 ... [ 31.788074] IPVS: Creating netns size=2552 id=4 [ 31.797824] IPVS: stopping backup sync thread 3914 ... [ 31.804441] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.822657] IPVS: stopping backup sync thread 3929 ... [ 31.826098] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.847834] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.847927] IPVS: stopping backup sync thread 3928 ... [ 31.856296] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.861529] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.913846] IPVS: stopping backup sync thread 3936 ... [ 31.917011] IPVS: stopping backup sync thread 3938 ... [ 31.919787] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.942326] IPVS: stopping backup sync thread 3951 ... [ 31.949071] IPVS: stopping backup sync thread 3934 ... [ 31.956056] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.959202] IPVS: Creating netns size=2552 id=5 [ 31.971160] IPVS: stopping backup sync thread 3960 ... [ 31.985941] [ 31.986455] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 31.995875] ============================================= [ 32.001396] [ INFO: possible recursive locking detected ] [ 32.006914] 4.4.128-gbd23e3a #20 Not tainted [ 32.011291] --------------------------------------------- [ 32.016814] syz-executor4/3962 is trying to acquire lock: [ 32.022318] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 32.030237] [ 32.030237] but task is already holding lock: [ 32.036178] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 32.044084] [ 32.044084] other info that might help us debug this: [ 32.050717] Possible unsafe locking scenario: [ 32.050717] [ 32.056747] CPU0 [ 32.059307] ---- [ 32.061866] lock(rtnl_mutex); [ 32.065360] lock(rtnl_mutex); [ 32.069290] [ 32.069290] *** DEADLOCK *** [ 32.069290] [ 32.075327] May be due to missing lock nesting notation [ 32.075327] [ 32.082226] 2 locks held by syz-executor4/3962: [ 32.086868] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 32.095346] #1: (ipvs->sync_mutex){+.+.+.}, at: [] do_ip_vs_set_ctl+0x8e0/0xb70 [ 32.105103] [ 32.105103] stack backtrace: [ 32.109569] CPU: 0 PID: 3962 Comm: syz-executor4 Not tainted 4.4.128-gbd23e3a #20 [ 32.117156] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.126481] 0000000000000000 eb7b8944a92df49c ffff8801d8a374f0 ffffffff81e0daad [ 32.134478] ffffffff8539cfa0 ffffffff8539cfa0 ffffffff8539cfa0 ffff8801d8b23900 [ 32.142458] 00000002d87420b6 ffff8801d8a37698 ffffffff8140faf1 ffffffff85749700 [ 32.150462] Call Trace: [ 32.153023] [] dump_stack+0xc1/0x124 [ 32.158358] [] __lock_acquire.cold.58+0x154/0x58a [ 32.164823] [] ? add_lock_to_list.isra.27.constprop.41+0x140/0x1c0 [ 32.172764] [] ? debug_check_no_locks_freed+0x210/0x210 [ 32.179764] [] ? debug_check_no_locks_freed+0x210/0x210 [ 32.186755] [] ? __lock_is_held+0xa2/0xf0 [ 32.192526] [] lock_acquire+0x15e/0x450 [ 32.198120] [] ? rtnl_lock+0x17/0x20 [ 32.203454] [] ? rtnl_lock+0x17/0x20 [ 32.208789] [] mutex_lock_nested+0xbb/0x850 [ 32.214738] [] ? rtnl_lock+0x17/0x20 [ 32.220075] [] ? qtaguid_untag+0x41f/0x620 [ 32.225930] [] ? mutex_lock_killable_nested+0x980/0x980 [ 32.232921] [] ? _raw_spin_unlock_bh+0x30/0x40 [ 32.239124] [] ? qtaguid_untag+0x323/0x620 [ 32.244986] [] ? __lock_is_held+0xa2/0xf0 [ 32.250755] [] rtnl_lock+0x17/0x20 [ 32.255921] [] ip_mc_drop_socket+0x8c/0x230 [ 32.261873] [] inet_release+0x5b/0x1d0 [ 32.267383] [] sock_release+0x96/0x1c0 [ 32.272891] [] start_sync_thread+0xa18/0x1ed0 [ 32.279005] [] ? finish_task_switch+0x1e7/0x4e0 [ 32.285387] [] ? finish_task_switch+0x1bb/0x4e0 [ 32.291690] [] ? ip_vs_proc_sync_conn+0x827/0x827 [ 32.298156] [] ? ip_vs_sync_conn+0x27b0/0x27b0 [ 32.304359] [] ? mark_held_locks+0xc7/0x130 [ 32.310300] [] ? mutex_lock_nested+0x54e/0x850 [ 32.316504] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 32.323315] [] ? mutex_lock_nested+0x574/0x850 [ 32.329519] [] ? do_ip_vs_set_ctl+0x8e0/0xb70 [ 32.335636] [] ? mutex_lock_killable_nested+0x980/0x980 [ 32.342623] [] ? memcpy+0x45/0x50 [ 32.347697] [] do_ip_vs_set_ctl+0x8f2/0xb70 [ 32.353637] [] ? ip_vs_genl_set_cmd+0x970/0x970 [ 32.359929] [] ? debug_check_no_locks_freed+0x210/0x210 [ 32.366912] [] ? mutex_lock_nested+0x54e/0x850 [ 32.373116] [] ? __mutex_unlock_slowpath+0x209/0x3b0 [ 32.379840] [] ? __ww_mutex_lock+0x14c0/0x14c0 [ 32.386048] [] ? sock_has_perm+0x29f/0x400 [ 32.391905] [] ? mutex_unlock+0x9/0x10 [ 32.397418] [] nf_setsockopt+0x6d/0xc0 [ 32.402927] [] ip_setsockopt+0x9a/0xb0 [ 32.408440] [] tcp_setsockopt+0x88/0xe0 [ 32.414046] [] sock_common_setsockopt+0x9a/0xe0 [ 32.420338] [] SyS_setsockopt+0x166/0x260 [ 32.426106] [] ? SyS_recv+0x40/0x40 [ 32.431357] [] ? int_ret_from_sys_call+0x52/0xa3 [ 32.437743] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 32.444208] [] entry_SYSCALL_64_fastpath+0x22/0x9e