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 '10.128.10.14' (ECDSA) to the list of known hosts. 2018/04/18 19:28:29 parsed 1 programs 2018/04/18 19:28:29 executed programs: 0 syzkaller login: [ 26.093851] IPVS: Creating netns size=2536 id=1 [ 26.117951] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.130032] IPVS: Creating netns size=2536 id=2 [ 26.141734] IPVS: stopping backup sync thread 3791 ... [ 26.172853] IPVS: Creating netns size=2536 id=3 [ 26.188391] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.201604] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.207732] IPVS: stopping backup sync thread 3819 ... [ 26.208610] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.228647] IPVS: Creating netns size=2536 id=4 [ 26.249229] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.259857] IPVS: Creating netns size=2536 id=5 [ 26.266896] IPVS: stopping backup sync thread 3816 ... [ 26.282601] IPVS: stopping backup sync thread 3825 ... [ 26.287131] IPVS: stopping backup sync thread 3840 ... [ 26.294061] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.303385] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.313246] IPVS: Creating netns size=2536 id=6 [ 26.327020] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.343462] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.358895] IPVS: stopping backup sync thread 3869 ... [ 26.365576] IPVS: stopping backup sync thread 3878 ... [ 26.366796] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.368299] IPVS: Creating netns size=2536 id=7 [ 26.380886] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.384091] IPVS: stopping backup sync thread 3857 ... [ 26.388491] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.394232] IPVS: stopping backup sync thread 3862 ... [ 26.397727] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.402573] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.406632] IPVS: Creating netns size=2536 id=8 [ 26.421008] IPVS: stopping backup sync thread 3902 ... [ 26.429434] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.481578] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.500204] IPVS: stopping backup sync thread 3897 ... [ 26.511635] IPVS: stopping backup sync thread 3912 ... [ 26.517272] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.523707] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.527116] IPVS: stopping backup sync thread 3936 ... [ 26.529283] IPVS: stopping backup sync thread 3906 ... [ 26.535176] IPVS: stopping backup sync thread 3892 ... [ 26.538080] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.540710] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.549968] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.550069] IPVS: stopping backup sync thread 3919 ... [ 26.558270] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.574371] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.625251] IPVS: stopping backup sync thread 3975 ... [ 26.634713] IPVS: stopping backup sync thread 3956 ... [ 26.635261] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.647194] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.649333] IPVS: stopping backup sync thread 3966 ... [ 26.649412] IPVS: stopping backup sync thread 3980 ... [ 26.653490] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.654118] IPVS: stopping backup sync thread 3962 ... [ 26.657560] IPVS: stopping backup sync thread 3985 ... [ 26.669046] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.670152] IPVS: stopping backup sync thread 3973 ... [ 26.672833] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.698508] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.707979] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.748055] IPVS: stopping backup sync thread 4016 ... [ 26.755607] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 26.961945] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 27.007930] IPVS: stopping backup sync thread 4043 ... [ 27.017713] IPVS: stopping backup sync thread 4059 ... [ 27.023496] IPVS: stopping backup sync thread 4019 ... [ 27.030113] IPVS: stopping backup sync thread 4049 ... [ 27.030158] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 27.030784] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 27.039152] IPVS: stopping backup sync thread 4037 ... [ 27.040096] IPVS: stopping backup sync thread 4065 ... [ 27.040175] IPVS: stopping backup sync thread 4030 ... [ 27.040208] IPVS: stopping backup sync thread 4025 ... [ 27.041085] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 27.052103] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 27.056486] IPVS: sync thread started: state = BACKUP, mcast_ifn = tunl0, syncid = 4, id = 0 [ 27.071409] [ 27.071411] ============================================= [ 27.071413] [ INFO: possible recursive locking detected ] [ 27.071418] 4.9.94-g8683408 #3 Not tainted [ 27.071420] --------------------------------------------- [ 27.071423] syz-executor4/4081 is trying to acquire lock: [ 27.071447] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 27.071449] but task is already holding lock: [ 27.071459] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 27.071461] other info that might help us debug this: [ 27.071462] Possible unsafe locking scenario: [ 27.071462] [ 27.071464] CPU0 [ 27.071465] ---- [ 27.071469] lock(rtnl_mutex); [ 27.071472] lock(rtnl_mutex); [ 27.071474] [ 27.071474] *** DEADLOCK *** [ 27.071474] [ 27.071475] May be due to missing lock nesting notation [ 27.071475] [ 27.071479] 2 locks held by syz-executor4/4081: [ 27.071491] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 27.071506] #1: (ipvs->sync_mutex){+.+.+.}, at: [] do_ip_vs_set_ctl+0x90d/0xbd0 [ 27.071507] [ 27.071507] stack backtrace: [ 27.071515] CPU: 1 PID: 4081 Comm: syz-executor4 Not tainted 4.9.94-g8683408 #3 [ 27.071518] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.071530] ffff8801d7867470 ffffffff81d9b509 ffffffff853730e0 ffffffff853730e0 [ 27.071539] ffffffff853730e0 ffff8801d8c150e8 957a330be9dd4e8d ffff8801d7867630 [ 27.071547] ffffffff814258ef ffffffff84c6eca0 ffffffff84fc5588 ffffffff84c6eca4 [ 27.071548] Call Trace: [ 27.071559] [] dump_stack+0xc1/0x128 [ 27.071570] [] __lock_acquire.cold.59+0x166/0x5f8 [ 27.071582] [] ? debug_check_no_locks_freed+0x210/0x210 [ 27.071590] [] ? __lock_is_held+0xa2/0xf0 [ 27.071605] [] lock_acquire+0x130/0x3e0 [ 27.071612] [] ? rtnl_lock+0x17/0x20 [ 27.071619] [] ? rtnl_lock+0x17/0x20 [ 27.071630] [] mutex_lock_nested+0xc0/0x870 [ 27.071637] [] ? rtnl_lock+0x17/0x20 [ 27.071645] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.071653] [] ? qtaguid_untag+0x41a/0x620 [ 27.071661] [] ? mutex_trylock+0x3e0/0x3e0 [ 27.071668] [] ? _raw_spin_unlock_bh+0x30/0x40 [ 27.071676] [] ? qtaguid_untag+0x31e/0x620 [ 27.071683] [] rtnl_lock+0x17/0x20 [ 27.071694] [] ip_mc_drop_socket+0x8c/0x230 [ 27.071701] [] inet_release+0x5b/0x1d0 [ 27.071709] [] sock_release+0x96/0x1c0 [ 27.071717] [] start_sync_thread+0xa0e/0x1ea0 [ 27.071725] [] ? ip_vs_proc_sync_conn+0x952/0x952 [ 27.071732] [] ? ip_vs_sync_conn+0x2a90/0x2a90 [ 27.071739] [] ? mark_held_locks+0xc7/0x130 [ 27.071745] [] ? mutex_lock_nested+0x572/0x870 [ 27.071752] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.071760] [] ? mutex_lock_nested+0x596/0x870 [ 27.071766] [] ? do_ip_vs_set_ctl+0x90d/0xbd0 [ 27.071773] [] ? mutex_trylock+0x3e0/0x3e0 [ 27.071781] [] ? memcpy+0x45/0x50 [ 27.071788] [] do_ip_vs_set_ctl+0x91f/0xbd0 [ 27.071798] [] ? get_futex_key+0x1090/0x1090 [ 27.071804] [] ? ip_vs_genl_set_cmd+0x9c0/0x9c0 [ 27.071812] [] ? mutex_lock_nested+0x572/0x870 [ 27.071820] [] ? __mutex_unlock_slowpath+0x221/0x3c0 [ 27.071826] [] ? __ww_mutex_lock+0x14c0/0x14c0 [ 27.071833] [] ? sock_has_perm+0x1c2/0x3e0 [ 27.071840] [] ? mutex_unlock+0x9/0x10 [ 27.071849] [] ? nf_sockopt_find.constprop.0+0x1b1/0x230 [ 27.071857] [] compat_nf_setsockopt+0x10d/0x130 [ 27.071867] [] compat_ip_setsockopt+0xa7/0xe0 [ 27.071876] [] inet_csk_compat_setsockopt+0x97/0x120 [ 27.071882] [] ? ip_setsockopt+0xb0/0xb0 [ 27.071889] [] compat_tcp_setsockopt+0x3d/0x70 [ 27.071896] [] compat_sock_common_setsockopt+0xb4/0x150 [ 27.071902] [] ? tcp_setsockopt+0xe0/0xe0 [ 27.071909] [] compat_SyS_setsockopt+0x14c/0x2a0 [ 27.071915] [] ? sock_common_setsockopt+0xe0/0xe0 [ 27.071922] [] ? scm_detach_fds_compat+0x3b0/0x3b0 [ 27.071931] [] ? do_fast_syscall_32+0xcf/0x870 [ 27.071938] [] ? scm_detach_fds_compat+0x3b0/0x3b0 [ 27.071944] [] do_fast_syscall_32+0x2f7/0x870 [ 27.071950] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 27.071957] [] entry_SYSENTER_compat+0x90/0xa2 [ 27.889257] IPVS: stopping backup sync thread 4109 ... [ 27.894908] IPVS: stopping backup sync thread 4101 ... [ 27.900346] IPVS: stopping backup sync thread 4105 ... [ 27.905192] IPVS: stopping backup sync thread 4121 ... [ 27.905671] IPVS: stopping backup sync thread 4116 ...