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 '10.128.0.55' (ECDSA) to the list of known hosts. 2018/04/20 06:13:38 parsed 1 programs 2018/04/20 06:13:38 executed programs: 0 syzkaller login: [ 21.635325] IPVS: Creating netns size=2536 id=1 [ 21.657735] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.657837] IPVS: stopping backup sync thread 3814 ... [ 21.672364] IPVS: Creating netns size=2536 id=2 [ 21.672889] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.672922] IPVS: stopping backup sync thread 3818 ... [ 21.690268] IPVS: stopping backup sync thread 3822 ... [ 21.690973] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.691005] IPVS: stopping backup sync thread 3824 ... [ 21.706471] IPVS: stopping backup sync thread 3828 ... [ 21.707121] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.707151] IPVS: stopping backup sync thread 3830 ... [ 21.723164] IPVS: stopping backup sync thread 3834 ... [ 21.723755] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.723786] IPVS: stopping backup sync thread 3836 ... [ 21.738580] IPVS: stopping backup sync thread 3840 ... [ 21.739165] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.739195] IPVS: stopping backup sync thread 3842 ... [ 21.755797] IPVS: stopping backup sync thread 3846 ... [ 21.756460] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.756491] IPVS: stopping backup sync thread 3848 ... [ 21.773043] IPVS: stopping backup sync thread 3852 ... [ 21.773706] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.773737] IPVS: stopping backup sync thread 3854 ... [ 21.788645] IPVS: stopping backup sync thread 3858 ... [ 21.789252] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.789282] IPVS: stopping backup sync thread 3860 ... [ 21.805829] IPVS: stopping backup sync thread 3864 ... [ 21.806441] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.806473] IPVS: stopping backup sync thread 3866 ... [ 21.858731] IPVS: stopping backup sync thread 3874 ... [ 21.864849] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.865017] IPVS: Creating netns size=2536 id=3 [ 21.874400] IPVS: stopping backup sync thread 3877 ... [ 21.891028] IPVS: stopping backup sync thread 3885 ... [ 21.896557] IPVS: Creating netns size=2536 id=4 [ 21.897049] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.897090] IPVS: stopping backup sync thread 3888 ... [ 21.930558] IPVS: stopping backup sync thread 3895 ... [ 21.936261] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.945508] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.946909] IPVS: Creating netns size=2536 id=5 [ 21.953905] IPVS: stopping backup sync thread 3899 ... [ 21.970307] IPVS: stopping backup sync thread 3906 ... [ 21.975900] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 21.985127] IPVS: Creating netns size=2536 id=6 [ 21.993248] IPVS: stopping backup sync thread 3913 ... [ 21.999488] IPVS: stopping backup sync thread 3918 ... [ 22.005258] [ 22.005260] ============================================= [ 22.005262] [ INFO: possible recursive locking detected ] [ 22.005266] 4.9.94-g8683408 #4 Not tainted [ 22.005268] --------------------------------------------- [ 22.005271] syz-executor4/3911 is trying to acquire lock: [ 22.005291] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 22.005293] but task is already holding lock: [ 22.005303] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 22.005305] other info that might help us debug this: [ 22.005306] Possible unsafe locking scenario: [ 22.005306] [ 22.005308] CPU0 [ 22.005309] ---- [ 22.005312] lock(rtnl_mutex); [ 22.005316] lock(rtnl_mutex); [ 22.005318] [ 22.005318] *** DEADLOCK *** [ 22.005318] [ 22.005319] May be due to missing lock nesting notation [ 22.005319] [ 22.005323] 2 locks held by syz-executor4/3911: [ 22.005334] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 22.005347] #1: (ipvs->sync_mutex){+.+.+.}, at: [] do_ip_vs_set_ctl+0x90d/0xbd0 [ 22.005348] [ 22.005348] stack backtrace: [ 22.005354] CPU: 0 PID: 3911 Comm: syz-executor4 Not tainted 4.9.94-g8683408 #4 [ 22.005357] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 22.005368] ffff8801b6a57470 ffffffff81eb0aa9 ffffffff8539d0e0 ffffffff8539d0e0 [ 22.005377] ffffffff8539d0e0 ffff8801b68bb8e8 040505bd965bed0c ffff8801b6a57630 [ 22.005385] ffffffff814258ef ffffffff84c98ca0 ffffffff84fede90 ffffffff84c98ca4 [ 22.005386] Call Trace: [ 22.005397] [] dump_stack+0xc1/0x128 [ 22.005409] [] __lock_acquire.cold.59+0x166/0x5f8 [ 22.005418] [] ? debug_check_no_locks_freed+0x210/0x210 [ 22.005427] [] ? __lock_is_held+0xa2/0xf0 [ 22.005433] [] lock_acquire+0x130/0x3e0 [ 22.005438] [] ? rtnl_lock+0x17/0x20 [ 22.005445] [] ? rtnl_lock+0x17/0x20 [ 22.005454] [] mutex_lock_nested+0xc0/0x870 [ 22.005460] [] ? rtnl_lock+0x17/0x20 [ 22.005468] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 22.005475] [] ? qtaguid_untag+0x41a/0x620 [ 22.005482] [] ? mutex_trylock+0x3e0/0x3e0 [ 22.005489] [] ? _raw_spin_unlock_bh+0x30/0x40 [ 22.005495] [] ? qtaguid_untag+0x31e/0x620 [ 22.005501] [] ? __lock_is_held+0xa2/0xf0 [ 22.005508] [] rtnl_lock+0x17/0x20 [ 22.005516] [] ip_mc_drop_socket+0x8c/0x230 [ 22.005522] [] inet_release+0x5b/0x1d0 [ 22.005530] [] sock_release+0x96/0x1c0 [ 22.005538] [] start_sync_thread+0xa0e/0x1ea0 [ 22.005545] [] ? ip_vs_proc_sync_conn+0x952/0x952 [ 22.005552] [] ? ip_vs_sync_conn+0x2a90/0x2a90 [ 22.005558] [] ? mark_held_locks+0xc7/0x130 [ 22.005573] [] ? mutex_lock_nested+0x572/0x870 [ 22.005580] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 22.005586] [] ? mutex_lock_nested+0x596/0x870 [ 22.005592] [] ? do_ip_vs_set_ctl+0x90d/0xbd0 [ 22.005599] [] ? mutex_trylock+0x3e0/0x3e0 [ 22.005606] [] ? memcpy+0x45/0x50 [ 22.005612] [] do_ip_vs_set_ctl+0x91f/0xbd0 [ 22.005620] [] ? get_futex_key+0x1090/0x1090 [ 22.005627] [] ? ip_vs_genl_set_cmd+0x9c0/0x9c0 [ 22.005634] [] ? mutex_lock_nested+0x572/0x870 [ 22.005641] [] ? __mutex_unlock_slowpath+0x221/0x3c0 [ 22.005648] [] ? __ww_mutex_lock+0x14c0/0x14c0 [ 22.005656] [] ? sock_has_perm+0x1c2/0x3e0 [ 22.005663] [] ? mutex_unlock+0x9/0x10 [ 22.005672] [] ? nf_sockopt_find.constprop.0+0x1b1/0x230 [ 22.005679] [] compat_nf_setsockopt+0x10d/0x130 [ 22.005686] [] compat_ip_setsockopt+0xa7/0xe0 [ 22.005693] [] inet_csk_compat_setsockopt+0x97/0x120 [ 22.005699] [] ? ip_setsockopt+0xb0/0xb0 [ 22.005706] [] compat_tcp_setsockopt+0x3d/0x70 [ 22.005713] [] compat_sock_common_setsockopt+0xb4/0x150 [ 22.005719] [] ? tcp_setsockopt+0xe0/0xe0 [ 22.005728] [] compat_SyS_setsockopt+0x14c/0x2a0 [ 22.005734] [] ? sock_common_setsockopt+0xe0/0xe0 [ 22.005741] [] ? scm_detach_fds_compat+0x3b0/0x3b0 [ 22.005748] [] ? do_fast_syscall_32+0xcf/0x870 [ 22.005755] [] ? scm_detach_fds_compat+0x3b0/0x3b0 [ 22.005761] [] do_fast_syscall_32+0x2f7/0x870 [ 22.005768] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 22.005775] [] entry_SYSENTER_compat+0x90/0xa2 [ 22.007082] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 22.023459] IPVS: Creating netns size=2536 id=7