[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 12.717146] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 17.558175] random: sshd: uninitialized urandom read (32 bytes read) [ 17.821579] random: sshd: uninitialized urandom read (32 bytes read) [ 18.622769] random: sshd: uninitialized urandom read (32 bytes read) [ 18.753586] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.30' (ECDSA) to the list of known hosts. [ 24.177599] random: sshd: uninitialized urandom read (32 bytes read) 2018/04/30 12:47:27 parsed 1 programs 2018/04/30 12:47:27 executed programs: 0 [ 24.616334] IPVS: Creating netns size=2536 id=1 [ 24.641722] IPVS: Creating netns size=2536 id=2 [ 24.661123] IPVS: Creating netns size=2536 id=3 [ 24.667910] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.676301] IPVS: stopping backup sync thread 3831 ... [ 24.685619] IPVS: stopping backup sync thread 3836 ... [ 24.691826] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.700175] IPVS: stopping backup sync thread 3845 ... [ 24.711961] IPVS: Creating netns size=2536 id=4 [ 24.717463] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.717606] IPVS: stopping backup sync thread 3840 ... [ 24.718397] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.719920] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.729482] IPVS: stopping backup sync thread 3854 ... [ 24.747091] IPVS: stopping backup sync thread 3852 ... [ 24.747687] IPVS: stopping backup sync thread 3848 ... [ 24.749748] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.758666] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.760867] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.832757] IPVS: stopping backup sync thread 3869 ... [ 24.834024] IPVS: stopping backup sync thread 3884 ... [ 24.836543] IPVS: stopping backup sync thread 3864 ... [ 24.841477] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.846751] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.850380] IPVS: stopping backup sync thread 3888 ... [ 24.855286] IPVS: Creating netns size=2536 id=5 [ 24.861232] IPVS: stopping backup sync thread 3872 ... [ 24.866591] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.873764] IPVS: stopping backup sync thread 3890 ... [ 24.877681] IPVS: stopping backup sync thread 3898 ... [ 24.878145] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.889193] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.896638] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.901201] IPVS: stopping backup sync thread 3906 ... [ 24.903199] IPVS: Creating netns size=2536 id=6 [ 24.925774] IPVS: stopping backup sync thread 3924 ... [ 24.928076] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.940098] IPVS: Creating netns size=2536 id=7 [ 24.948467] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 24.966269] IPVS: stopping backup sync thread 3936 ... [ 24.973703] IPVS: Creating netns size=2536 id=8 [ 24.990675] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.013661] IPVS: stopping backup sync thread 3947 ... [ 25.013804] IPVS: stopping backup sync thread 3950 ... [ 25.016597] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.025960] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.035114] IPVS: stopping backup sync thread 3953 ... [ 25.039645] IPVS: stopping backup sync thread 3931 ... [ 25.040214] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.040302] IPVS: stopping backup sync thread 3911 ... [ 25.042308] IPVS: stopping backup sync thread 3957 ... [ 25.048318] IPVS: stopping backup sync thread 3926 ... [ 25.049315] IPVS: stopping backup sync thread 3913 ... [ 25.055052] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.055056] IPVS: stopping backup sync thread 3943 ... [ 25.072582] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.083841] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.086018] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.095266] IPVS: stopping backup sync thread 3971 ... [ 25.095393] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.101662] IPVS: stopping backup sync thread 3980 ... [ 25.101688] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.104178] IPVS: stopping backup sync thread 3982 ... [ 25.113988] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.114249] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.130295] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.284471] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.328720] IPVS: stopping backup sync thread 4003 ... [ 25.341207] IPVS: stopping backup sync thread 4001 ... [ 25.342317] IPVS: stopping backup sync thread 3989 ... [ 25.345090] IPVS: stopping backup sync thread 4000 ... [ 25.345427] IPVS: stopping backup sync thread 3991 ... [ 25.348789] IPVS: stopping backup sync thread 3987 ... [ 25.350487] IPVS: stopping backup sync thread 4010 ... [ 25.351670] IPVS: stopping backup sync thread 3993 ... [ 25.353440] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.353663] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.353988] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.354216] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.367962] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 25.384568] [ 25.384570] ============================================= [ 25.384572] [ INFO: possible recursive locking detected ] [ 25.384576] 4.9.96-g71fce1e #10 Not tainted [ 25.384578] --------------------------------------------- [ 25.384582] syz-executor5/4030 is trying to acquire lock: [ 25.384602] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 25.384603] but task is already holding lock: [ 25.384613] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 25.384614] other info that might help us debug this: [ 25.384616] Possible unsafe locking scenario: [ 25.384616] [ 25.384617] CPU0 [ 25.384618] ---- [ 25.384622] lock(rtnl_mutex); [ 25.384626] lock(rtnl_mutex); [ 25.384627] [ 25.384627] *** DEADLOCK *** [ 25.384627] [ 25.384629] May be due to missing lock nesting notation [ 25.384629] [ 25.384632] 2 locks held by syz-executor5/4030: [ 25.384643] #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 [ 25.384655] #1: (ipvs->sync_mutex){+.+.+.}, at: [] do_ip_vs_set_ctl+0x90d/0xbd0 [ 25.384657] [ 25.384657] stack backtrace: [ 25.384663] CPU: 0 PID: 4030 Comm: syz-executor5 Not tainted 4.9.96-g71fce1e #10 [ 25.384666] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.384677] ffff8801d782f410 ffffffff81eb0b69 ffffffff8539cf30 ffffffff8539cf30 [ 25.384685] ffffffff8539cf30 ffff8801d75ad0e8 a688d1a87b878d66 ffff8801d782f5d0 [ 25.384692] ffffffff81425a1f ffffffff84c98ca0 ffffffff84fee220 ffffffff84c98ca4 [ 25.384694] Call Trace: [ 25.384703] [] dump_stack+0xc1/0x128 [ 25.384713] [] __lock_acquire.cold.59+0x166/0x5f8 [ 25.384722] [] ? debug_check_no_locks_freed+0x210/0x210 [ 25.384729] [] ? __lock_is_held+0xa2/0xf0 [ 25.384736] [] lock_acquire+0x130/0x3e0 [ 25.384742] [] ? rtnl_lock+0x17/0x20 [ 25.384749] [] ? rtnl_lock+0x17/0x20 [ 25.384757] [] mutex_lock_nested+0xc0/0x870 [ 25.384762] [] ? rtnl_lock+0x17/0x20 [ 25.384768] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 25.384775] [] ? qtaguid_untag+0x41a/0x620 [ 25.384782] [] ? mutex_trylock+0x3e0/0x3e0 [ 25.384790] [] ? _raw_spin_unlock_bh+0x30/0x40 [ 25.384796] [] ? qtaguid_untag+0x31e/0x620 [ 25.384802] [] ? __lock_is_held+0xa2/0xf0 [ 25.384809] [] rtnl_lock+0x17/0x20 [ 25.384818] [] ip_mc_drop_socket+0x8c/0x230 [ 25.384824] [] inet_release+0x5b/0x1d0 [ 25.384832] [] sock_release+0x96/0x1c0 [ 25.384839] [] start_sync_thread+0xa0e/0x1ea0 [ 25.384848] [] ? ip_vs_proc_sync_conn+0x952/0x952 [ 25.384854] [] ? ip_vs_sync_conn+0x2a90/0x2a90 [ 25.384861] [] ? mark_held_locks+0xc7/0x130 [ 25.384868] [] ? mutex_lock_nested+0x572/0x870 [ 25.384875] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 25.384881] [] ? mutex_lock_nested+0x596/0x870 [ 25.384887] [] ? do_ip_vs_set_ctl+0x90d/0xbd0 [ 25.384894] [] ? mutex_trylock+0x3e0/0x3e0 [ 25.384900] [] ? memcpy+0x45/0x50 [ 25.384907] [] do_ip_vs_set_ctl+0x91f/0xbd0 [ 25.384913] [] ? __lock_acquire+0x654/0x4070 [ 25.384919] [] ? ip_vs_genl_set_cmd+0x9c0/0x9c0 [ 25.384926] [] ? mutex_lock_nested+0x572/0x870 [ 25.384934] [] ? __mutex_unlock_slowpath+0x25b/0x3c0 [ 25.384942] [] ? __mutex_unlock_slowpath+0x221/0x3c0 [ 25.384949] [] ? __ww_mutex_lock+0x14c0/0x14c0 [ 25.384958] [] ? check_preemption_disabled+0x3b/0x170 [ 25.384965] [] ? mutex_unlock+0x9/0x10 [ 25.384973] [] nf_setsockopt+0x6d/0xc0 [ 25.384980] [] ip_setsockopt+0x9a/0xb0 [ 25.384989] [] udp_setsockopt+0x4a/0x90 [ 25.384997] [] ipv6_setsockopt+0x10a/0x130 [ 25.385004] [] udpv6_setsockopt+0x4a/0x90 [ 25.385010] [] sock_common_setsockopt+0x9a/0xe0 [ 25.385017] [] SyS_setsockopt+0x166/0x260 [ 25.385024] [] ? SyS_recv+0x40/0x40 [ 25.385031] [] ? _raw_spin_unlock_irq+0x27/0x50 [ 25.385039] [] ? do_syscall_64+0x48/0x490 [ 25.385046] [] ? SyS_recv+0x40/0x40 [ 25.385053] [] do_syscall_64+0x1a6/0x490 [ 25.385059] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.386502] IPVS: sync thread started: state = BACKUP, mcast_ifn = lo, syncid = 4, id = 0 [ 26.172853] IPVS: stopping backup sync thread 4038 ... [ 26.189060] IPVS: stopping backup sync thread 4037 ... [ 26.189351] IPVS: stopping backup sync thread 4040 ... [ 26.194483] IPVS: stopping backup sync thread 4039 ... [ 26.194509] IPVS: stopping backup sync thread 4036 ... [ 26.195322] IPVS: stopping backup sync thread 4035 ...