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 '10.128.0.43' (ECDSA) to the list of known hosts. 2018/04/15 17:38:39 parsed 1 programs 2018/04/15 17:38:39 executed programs: 0 syzkaller login: [ 24.193883] IPVS: Creating netns size=2536 id=1 [ 24.216352] IPVS: Creating netns size=2536 id=2 [ 24.231214] IPVS: stopping backup sync thread 3803 ... [ 24.234950] IPVS: stopping backup sync thread 3806 ... [ 24.241634] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.241653] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.250807] IPVS: Creating netns size=2536 id=3 [ 24.266351] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.273462] IPVS: stopping backup sync thread 3821 ... [ 24.275808] IPVS: Creating netns size=2536 id=4 [ 24.283341] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.291510] IPVS: stopping backup sync thread 3829 ... [ 24.298569] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.310979] IPVS: Creating netns size=2536 id=5 [ 24.315706] IPVS: stopping backup sync thread 3809 ... [ 24.323438] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.343026] IPVS: Creating netns size=2536 id=6 [ 24.346088] IPVS: stopping backup sync thread 3846 ... [ 24.355199] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.377524] IPVS: stopping backup sync thread 3824 ... [ 24.385958] IPVS: Creating netns size=2536 id=7 [ 24.396016] IPVS: stopping backup sync thread 3819 ... [ 24.403212] IPVS: stopping backup sync thread 3866 ... [ 24.409877] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.423063] IPVS: Creating netns size=2536 id=8 [ 24.423946] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.424578] IPVS: stopping backup sync thread 3833 ... [ 24.428064] IPVS: stopping backup sync thread 3882 ... [ 24.429194] IPVS: stopping backup sync thread 3839 ... [ 24.440674] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.453391] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.453710] IPVS: stopping backup sync thread 3848 ... [ 24.453733] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.453757] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.465464] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.465798] IPVS: stopping backup sync thread 3907 ... [ 24.467447] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.489399] IPVS: stopping backup sync thread 3869 ... [ 24.523678] IPVS: stopping backup sync thread 3872 ... [ 24.541191] IPVS: stopping backup sync thread 3900 ... [ 24.541492] IPVS: stopping backup sync thread 3901 ... [ 24.541915] IPVS: stopping backup sync thread 3909 ... [ 24.541939] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.543712] IPVS: stopping backup sync thread 3906 ... [ 24.548375] IPVS: stopping backup sync thread 3889 ... [ 24.548447] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.558144] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 24.559901] IPVS: stopping backup sync thread 3894 ... [ 24.570298] [ 24.570300] ============================================= [ 24.570301] [ INFO: possible recursive locking detected ] [ 24.570304] 4.9.94-g8683408 #3 Not tainted [ 24.570305] --------------------------------------------- [ 24.570307] syz-executor6/3930 is trying to acquire lock: [ 24.570324] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 24.570325] but task is already holding lock: [ 24.570331] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 24.570332] other info that might help us debug this: [ 24.570333] Possible unsafe locking scenario: [ 24.570333] [ 24.570334] CPU0 [ 24.570335] ---- [ 24.570337] lock(rtnl_mutex); [ 24.570339] lock(rtnl_mutex); [ 24.570340] [ 24.570340] *** DEADLOCK *** [ 24.570340] [ 24.570341] May be due to missing lock nesting notation [ 24.570341] [ 24.570343] 2 locks held by syz-executor6/3930: [ 24.570350] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 24.570361] #1: (ipvs->sync_mutex){+.+.+.}, at: [] do_ip_vs_set_ctl+0x90d/0xbd0 [ 24.570361] [ 24.570361] stack backtrace: [ 24.570366] CPU: 1 PID: 3930 Comm: syz-executor6 Not tainted 4.9.94-g8683408 #3 [ 24.570368] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.570375] ffff8801b6daf470 ffffffff81d9b509 ffffffff853730e0 ffffffff853730e0 [ 24.570380] ffffffff853730e0 ffff8801b6cbe8e8 b1a251082d33e5b4 ffff8801b6daf630 [ 24.570385] ffffffff814258ef ffffffff84c6eca0 ffffffff84fc5658 ffffffff84c6eca4 [ 24.570386] Call Trace: [ 24.570395] [] dump_stack+0xc1/0x128 [ 24.570403] [] __lock_acquire.cold.59+0x166/0x5f8 [ 24.570412] [] ? debug_check_no_locks_freed+0x210/0x210 [ 24.570416] [] ? __lock_is_held+0xa2/0xf0 [ 24.570420] [] lock_acquire+0x130/0x3e0 [ 24.570424] [] ? rtnl_lock+0x17/0x20 [ 24.570428] [] ? rtnl_lock+0x17/0x20 [ 24.570437] [] mutex_lock_nested+0xc0/0x870 [ 24.570441] [] ? rtnl_lock+0x17/0x20 [ 24.570445] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 24.570451] [] ? qtaguid_untag+0x41a/0x620 [ 24.570455] [] ? mutex_trylock+0x3e0/0x3e0 [ 24.570459] [] ? _raw_spin_unlock_bh+0x30/0x40 [ 24.570463] [] ? qtaguid_untag+0x31e/0x620 [ 24.570466] [] ? __lock_is_held+0xa2/0xf0 [ 24.570470] [] rtnl_lock+0x17/0x20 [ 24.570478] [] ip_mc_drop_socket+0x8c/0x230 [ 24.570482] [] inet_release+0x5b/0x1d0 [ 24.570488] [] sock_release+0x96/0x1c0 [ 24.570493] [] start_sync_thread+0xa0e/0x1ea0 [ 24.570499] [] ? ip_vs_proc_sync_conn+0x952/0x952 [ 24.570503] [] ? ip_vs_sync_conn+0x2a90/0x2a90 [ 24.570507] [] ? mark_held_locks+0xc7/0x130 [ 24.570511] [] ? mutex_lock_nested+0x572/0x870 [ 24.570515] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 24.570520] [] ? mutex_lock_nested+0x596/0x870 [ 24.570523] [] ? do_ip_vs_set_ctl+0x90d/0xbd0 [ 24.570527] [] ? mutex_trylock+0x3e0/0x3e0 [ 24.570532] [] ? memcpy+0x45/0x50 [ 24.570536] [] do_ip_vs_set_ctl+0x91f/0xbd0 [ 24.570541] [] ? get_futex_key+0x1090/0x1090 [ 24.570545] [] ? ip_vs_genl_set_cmd+0x9c0/0x9c0 [ 24.570549] [] ? mutex_lock_nested+0x572/0x870 [ 24.570554] [] ? __mutex_unlock_slowpath+0x221/0x3c0 [ 24.570558] [] ? __ww_mutex_lock+0x14c0/0x14c0 [ 24.570563] [] ? sock_has_perm+0x1c2/0x3e0 [ 24.570567] [] ? mutex_unlock+0x9/0x10 [ 24.570572] [] ? nf_sockopt_find.constprop.0+0x1b1/0x230 [ 24.570576] [] compat_nf_setsockopt+0x10d/0x130 [ 24.570581] [] compat_ip_setsockopt+0xa7/0xe0 [ 24.570585] [] inet_csk_compat_setsockopt+0x97/0x120 [ 24.570589] [] ? ip_setsockopt+0xb0/0xb0 [ 24.570593] [] compat_tcp_setsockopt+0x3d/0x70 [ 24.570597] [] compat_sock_common_setsockopt+0xb4/0x150 [ 24.570601] [] ? tcp_setsockopt+0xe0/0xe0 [ 24.570607] [] compat_SyS_setsockopt+0x14c/0x2a0 [ 24.570611] [] ? sock_common_setsockopt+0xe0/0xe0 [ 24.570615] [] ? scm_detach_fds_compat+0x3b0/0x3b0 [ 24.570622] [] ? do_fast_syscall_32+0xcf/0x870 [ 24.570626] [] ? scm_detach_fds_compat+0x3b0/0x3b0 [ 24.570630] [] do_fast_syscall_32+0x2f7/0x870 [ 24.570633] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 24.570638] [] entry_SYSENTER_compat+0x90/0xa2 [ 24.573897] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 25.418229] IPVS: stopping backup sync thread 3936 ... [ 25.422763] IPVS: stopping backup sync thread 3943 ... [ 25.448701] IPVS: stopping backup sync thread 3944 ... [ 25.457786] IPVS: stopping backup sync thread 3947 ...