[....] 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[ 21.431477] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.976461] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 26.365040] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 27.298960] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.38' (ECDSA) to the list of known hosts. 2018/04/28 15:53:51 parsed 1 programs 2018/04/28 15:53:51 executed programs: 0 [ 43.287439] IPVS: Creating netns size=2552 id=1 [ 43.330639] IPVS: Creating netns size=2552 id=2 [ 43.363872] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.364423] IPVS: stopping backup sync thread 3890 ... [ 43.382381] IPVS: Unknown mcast interface: ipddp0 [ 43.389020] IPVS: stopping backup sync thread 3897 ... [ 43.394514] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.397201] IPVS: Creating netns size=2552 id=3 [ 43.401973] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.405472] IPVS: Unknown mcast interface: ipddp0 [ 43.406053] IPVS: stopping backup sync thread 3900 ... [ 43.408496] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.430903] IPVS: stopping backup sync thread 3902 ... [ 43.447691] IPVS: stopping backup sync thread 3910 ... [ 43.451343] IPVS: stopping backup sync thread 3913 ... [ 43.451423] IPVS: Unknown mcast interface: ipddp0 [ 43.452279] IPVS: stopping backup sync thread 3915 ... [ 43.470164] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.476570] IPVS: stopping backup sync thread 3921 ... [ 43.476668] IPVS: Unknown mcast interface: ipddp0 [ 43.479733] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.479752] IPVS: stopping backup sync thread 3923 ... [ 43.479837] IPVS: stopping backup sync thread 3924 ... [ 43.480045] IPVS: Unknown mcast interface: ipddp0 [ 43.480649] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.480662] IPVS: stopping backup sync thread 3926 ... [ 43.483763] IPVS: Creating netns size=2552 id=4 [ 43.523180] IPVS: stopping backup sync thread 3932 ... [ 43.523800] IPVS: stopping backup sync thread 3933 ... [ 43.527805] IPVS: Unknown mcast interface: ipddp0 [ 43.533381] IPVS: stopping backup sync thread 3935 ... [ 43.534438] IPVS: Unknown mcast interface: ipddp0 [ 43.544548] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.544560] IPVS: stopping backup sync thread 3937 ... [ 43.568621] IPVS: stopping backup sync thread 3942 ... [ 43.568736] IPVS: Unknown mcast interface: ipddp0 [ 43.572336] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.572927] IPVS: stopping backup sync thread 3944 ... [ 43.586591] IPVS: stopping backup sync thread 3946 ... [ 43.586664] IPVS: Unknown mcast interface: ipddp0 [ 43.589557] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.589643] IPVS: stopping backup sync thread 3950 ... [ 43.612376] IPVS: stopping backup sync thread 3955 ... [ 43.612508] IPVS: Unknown mcast interface: ipddp0 [ 43.617899] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.617938] IPVS: stopping backup sync thread 3957 ... [ 43.648779] IPVS: stopping backup sync thread 3964 ... [ 43.650620] IPVS: Creating netns size=2552 id=5 [ 43.658838] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.662412] IPVS: Unknown mcast interface: ipddp0 [ 43.665257] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.666359] IPVS: stopping backup sync thread 3966 ... [ 43.693725] IPVS: Unknown mcast interface: ipddp0 [ 43.699547] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.710514] IPVS: stopping backup sync thread 3975 ... [ 43.712562] IPVS: stopping backup sync thread 3971 ... [ 43.723790] IPVS: Unknown mcast interface: ipddp0 [ 43.731058] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.742305] IPVS: Creating netns size=2552 id=6 [ 43.756573] IPVS: stopping backup sync thread 3991 ... [ 43.762366] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.762390] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.762977] IPVS: Unknown mcast interface: ipddp0 [ 43.764843] IPVS: stopping backup sync thread 3995 ... [ 43.771503] IPVS: stopping backup sync thread 3996 ... [ 43.771569] IPVS: Unknown mcast interface: ipddp0 [ 43.772274] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.772281] IPVS: stopping backup sync thread 3998 ... [ 43.799806] IPVS: stopping backup sync thread 3992 ... [ 43.805176] IPVS: stopping backup sync thread 3980 ... [ 43.805209] IPVS: stopping backup sync thread 4002 ... [ 43.809234] IPVS: Unknown mcast interface: ipddp0 [ 43.809316] IPVS: Unknown mcast interface: ipddp0 [ 43.810536] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.820221] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.863713] IPVS: stopping backup sync thread 4015 ... [ 43.865105] IPVS: Unknown mcast interface: ipddp0 [ 43.865787] IPVS: stopping backup sync thread 4017 ... [ 43.876338] IPVS: Creating netns size=2552 id=7 [ 43.883881] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.894463] IPVS: Unknown mcast interface: ipddp0 [ 43.900681] IPVS: stopping backup sync thread 4021 ... [ 43.933026] IPVS: stopping backup sync thread 4029 ... [ 43.938536] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 43.944306] IPVS: Creating netns size=2552 id=8 [ 43.957384] IPVS: Unknown mcast interface: ipddp0 [ 43.968071] [ 43.969699] ============================================= [ 43.975216] [ INFO: possible recursive locking detected ] [ 43.980727] 4.4.129-g23eaecc #27 Not tainted [ 43.985107] --------------------------------------------- [ 43.990617] syz-executor2/4028 is trying to acquire lock: [ 43.996121] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 44.004030] [ 44.004030] but task is already holding lock: [ 44.009969] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 44.017881] [ 44.017881] other info that might help us debug this: [ 44.024515] Possible unsafe locking scenario: [ 44.024515] [ 44.030550] CPU0 [ 44.033113] ---- [ 44.035665] lock(rtnl_mutex); [ 44.039145] lock(rtnl_mutex); [ 44.042635] [ 44.042635] *** DEADLOCK *** [ 44.042635] [ 44.048667] May be due to missing lock nesting notation [ 44.048667] [ 44.055565] 2 locks held by syz-executor2/4028: [ 44.060209] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 44.068742] #1: (ipvs->sync_mutex){+.+.+.}, at: [] do_ip_vs_set_ctl+0x8e0/0xb70 [ 44.078499] [ 44.078499] stack backtrace: [ 44.082972] CPU: 0 PID: 4028 Comm: syz-executor2 Not tainted 4.4.129-g23eaecc #27 [ 44.090566] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.099900] 0000000000000000 13ef75391debfdf8 ffff8800babf74f0 ffffffff81e0dc8d [ 44.107974] ffffffff8539cdf0 ffffffff8539cdf0 ffffffff8539cdf0 ffff8800ac843900 [ 44.115989] 00000002d47440b5 ffff8800babf7698 ffffffff8140fb11 ffffffff85748000 [ 44.123978] Call Trace: [ 44.126538] [] dump_stack+0xc1/0x124 [ 44.131876] [] __lock_acquire.cold.58+0x154/0x58a [ 44.138349] [] ? add_lock_to_list.isra.27.constprop.41+0x140/0x1c0 [ 44.146293] [] ? debug_check_no_locks_freed+0x210/0x210 [ 44.153277] [] ? retint_kernel+0x2d/0x2d [ 44.158958] [] ? trace_hardirqs_on_caller+0x266/0x590 [ 44.165773] [] ? __lock_is_held+0xa2/0xf0 [ 44.171542] [] lock_acquire+0x15e/0x450 [ 44.177140] [] ? rtnl_lock+0x17/0x20 [ 44.182475] [] ? rtnl_lock+0x17/0x20 [ 44.187810] [] mutex_lock_nested+0xbb/0x850 [ 44.193750] [] ? rtnl_lock+0x17/0x20 [ 44.199086] [] ? qtaguid_untag+0x41f/0x620 [ 44.204941] [] ? mutex_lock_killable_nested+0x980/0x980 [ 44.211926] [] ? _raw_spin_unlock_bh+0x30/0x40 [ 44.218134] [] ? qtaguid_untag+0x323/0x620 [ 44.223990] [] ? __lock_is_held+0xa2/0xf0 [ 44.229758] [] rtnl_lock+0x17/0x20 [ 44.234920] [] ip_mc_drop_socket+0x8c/0x230 [ 44.240866] [] inet_release+0x5b/0x1d0 [ 44.246373] [] sock_release+0x96/0x1c0 [ 44.251884] [] start_sync_thread+0xa18/0x1ed0 [ 44.258012] [] ? finish_task_switch+0x1e7/0x4e0 [ 44.264303] [] ? finish_task_switch+0x1bb/0x4e0 [ 44.270604] [] ? ip_vs_proc_sync_conn+0x827/0x827 [ 44.277080] [] ? ip_vs_sync_conn+0x27b0/0x27b0 [ 44.283288] [] ? mark_held_locks+0xc7/0x130 [ 44.289236] [] ? mutex_lock_nested+0x54e/0x850 [ 44.295441] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 44.302252] [] ? mutex_lock_nested+0x574/0x850 [ 44.308456] [] ? do_ip_vs_set_ctl+0x8e0/0xb70 [ 44.314572] [] ? mutex_lock_killable_nested+0x980/0x980 [ 44.321556] [] ? memcpy+0x45/0x50 [ 44.326632] [] do_ip_vs_set_ctl+0x8f2/0xb70 [ 44.332575] [] ? ip_vs_genl_set_cmd+0x970/0x970 [ 44.338878] [] ? debug_check_no_locks_freed+0x210/0x210 [ 44.345882] [] ? mutex_lock_nested+0x54e/0x850 [ 44.352097] [] ? __mutex_unlock_slowpath+0x209/0x3b0 [ 44.358826] [] ? __ww_mutex_lock+0x14c0/0x14c0 [ 44.365039] [] ? sock_has_perm+0x29f/0x400 [ 44.370896] [] ? mutex_unlock+0x9/0x10 [ 44.376411] [] nf_setsockopt+0x6d/0xc0 [ 44.381922] [] ip_setsockopt+0x9a/0xb0 [ 44.387432] [] tcp_setsockopt+0x88/0xe0 [ 44.393040] [] sock_common_setsockopt+0x9a/0xe0 [ 44.399360] [] SyS_setsockopt+0x166/0x260 [ 44.405141] [] ? SyS_recv+0x40/0x40 [ 44.410408] [] ? move_addr_to_kernel+0x50/0x50 [ 44.416624] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 44.423104] [] entry_SYSCALL_64_fastpath+0x22/0x9e