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 '10.128.0.10' (ECDSA) to the list of known hosts. 2018/04/20 23:55:58 parsed 1 programs 2018/04/20 23:55:58 executed programs: 0 syzkaller login: [ 25.019997] IPVS: Creating netns size=2536 id=1 [ 25.045777] IPVS: Creating netns size=2536 id=2 [ 25.060505] IPVS: stopping backup sync thread 3826 ... [ 25.071559] IPVS: stopping backup sync thread 3834 ... [ 25.077398] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 25.084297] IPVS: stopping backup sync thread 3839 ... [ 25.087279] IPVS: Creating netns size=2536 id=3 [ 25.088511] IPVS: stopping backup sync thread 3841 ... [ 25.113806] IPVS: stopping backup sync thread 3849 ... [ 25.120097] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 25.128285] IPVS: stopping backup sync thread 3854 ... [ 25.128918] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 0, id = 0 [ 25.128938] IPVS: stopping backup sync thread 3856 ... [ 25.131707] IPVS: Creating netns size=2536 id=4 [ 25.159813] IPVS: stopping backup sync thread 3862 ... [ 25.166171] IPVS: stopping backup sync thread 3866 ... [ 25.172410] [ 25.172413] ============================================= [ 25.172414] [ INFO: possible recursive locking detected ] [ 25.172419] 4.9.95-g13cc540 #2 Not tainted [ 25.172420] --------------------------------------------- [ 25.172424] syz-executor0/3860 is trying to acquire lock: [ 25.172445] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 25.172446] but task is already holding lock: [ 25.172456] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 25.172458] other info that might help us debug this: [ 25.172459] Possible unsafe locking scenario: [ 25.172459] [ 25.172461] CPU0 [ 25.172462] ---- [ 25.172466] lock(rtnl_mutex); [ 25.172469] lock(rtnl_mutex); [ 25.172470] [ 25.172470] *** DEADLOCK *** [ 25.172470] [ 25.172472] May be due to missing lock nesting notation [ 25.172472] [ 25.172475] 2 locks held by syz-executor0/3860: [ 25.172486] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 25.172500] #1: (ipvs->sync_mutex){+.+.+.}, at: [] do_ip_vs_set_ctl+0x90d/0xbd0 [ 25.172502] [ 25.172502] stack backtrace: [ 25.172508] CPU: 1 PID: 3860 Comm: syz-executor0 Not tainted 4.9.95-g13cc540 #2 [ 25.172512] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.172524] ffff8801c2c8f480 ffffffff81eb0ba9 ffffffff8539d0e0 ffffffff8539d0e0 [ 25.172538] ffffffff8539d0e0 ffff8801d90350e8 6990255cf51cba53 ffff8801c2c8f640 [ 25.172547] ffffffff814259ef ffffffff84c98ca0 ffffffff84febc78 ffffffff84c98ca4 [ 25.172549] Call Trace: [ 25.172559] [] dump_stack+0xc1/0x128 [ 25.172572] [] __lock_acquire.cold.59+0x166/0x5f8 [ 25.172583] [] ? debug_check_no_locks_freed+0x210/0x210 [ 25.172591] [] ? __lock_is_held+0xa2/0xf0 [ 25.172598] [] lock_acquire+0x130/0x3e0 [ 25.172605] [] ? rtnl_lock+0x17/0x20 [ 25.172612] [] ? rtnl_lock+0x17/0x20 [ 25.172623] [] mutex_lock_nested+0xc0/0x870 [ 25.172628] [] ? rtnl_lock+0x17/0x20 [ 25.172635] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 25.172644] [] ? qtaguid_untag+0x41a/0x620 [ 25.172650] [] ? mutex_trylock+0x3e0/0x3e0 [ 25.172656] [] ? _raw_spin_unlock_bh+0x30/0x40 [ 25.172662] [] ? qtaguid_untag+0x31e/0x620 [ 25.172668] [] ? __lock_is_held+0xa2/0xf0 [ 25.172674] [] rtnl_lock+0x17/0x20 [ 25.172683] [] ip_mc_drop_socket+0x8c/0x230 [ 25.172690] [] inet_release+0x5b/0x1d0 [ 25.172699] [] sock_release+0x96/0x1c0 [ 25.172707] [] start_sync_thread+0xa0e/0x1ea0 [ 25.172716] [] ? ip_vs_proc_sync_conn+0x952/0x952 [ 25.172722] [] ? ip_vs_sync_conn+0x2a90/0x2a90 [ 25.172728] [] ? mark_held_locks+0xc7/0x130 [ 25.172735] [] ? mutex_lock_nested+0x572/0x870 [ 25.172741] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 25.172748] [] ? mutex_lock_nested+0x596/0x870 [ 25.172754] [] ? do_ip_vs_set_ctl+0x90d/0xbd0 [ 25.172760] [] ? mutex_trylock+0x3e0/0x3e0 [ 25.172767] [] ? memcpy+0x45/0x50 [ 25.172772] [] do_ip_vs_set_ctl+0x91f/0xbd0 [ 25.172778] [] ? ip_vs_genl_set_cmd+0x9c0/0x9c0 [ 25.172785] [] ? mutex_lock_nested+0x572/0x870 [ 25.172793] [] ? __mutex_unlock_slowpath+0x221/0x3c0 [ 25.172799] [] ? __ww_mutex_lock+0x14c0/0x14c0 [ 25.172809] [] ? sock_has_perm+0x292/0x3e0 [ 25.172815] [] ? mutex_unlock+0x9/0x10 [ 25.172825] [] ? nf_sockopt_find.constprop.0+0x1b1/0x230 [ 25.172832] [] nf_setsockopt+0x6d/0xc0 [ 25.172839] [] ip_setsockopt+0x9a/0xb0 [ 25.172846] [] tcp_setsockopt+0x88/0xe0 [ 25.172853] [] sock_common_setsockopt+0x9a/0xe0 [ 25.172860] [] SyS_setsockopt+0x166/0x260 [ 25.172866] [] ? SyS_recv+0x40/0x40 [ 25.172876] [] ? __do_page_fault+0x183/0xd50 [ 25.172883] [] ? move_addr_to_kernel+0x50/0x50 [ 25.172892] [] ? do_syscall_64+0x48/0x490 [ 25.172898] [] ? SyS_recv+0x40/0x40 [ 25.172904] [] do_syscall_64+0x1a6/0x490 [ 25.172911] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.187220] IPVS: Creating netns size=2536 id=5