[ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.5' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 36.619161] audit: type=1400 audit(1599090208.816:8): avc: denied { execmem } for pid=6351 comm="syz-executor061" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 36.642529] ip_tables: iptables: counters copy to user failed while replacing table [ 36.654269] IPVS: ftp: loaded support on port[0] = 21 [ 36.690163] ip_tables: iptables: counters copy to user failed while replacing table [ 36.701371] IPVS: ftp: loaded support on port[0] = 21 [ 36.738516] ip_tables: iptables: counters copy to user failed while replacing table [ 36.788963] [ 36.790610] ====================================================== [ 36.797003] WARNING: possible circular locking dependency detected [ 36.803565] 4.14.195-syzkaller #0 Not tainted [ 36.808043] ------------------------------------------------------ [ 36.814455] kworker/u4:5/6312 is trying to acquire lock: [ 36.819971] (&table[i].mutex){+.+.}, at: [] nf_tables_netdev_event+0x10d/0x4d0 [ 36.829345] [ 36.829345] but task is already holding lock: [ 36.835504] (rtnl_mutex){+.+.}, at: [] ip6gre_exit_net+0x70/0x570 [ 36.843446] [ 36.843446] which lock already depends on the new lock. [ 36.843446] [ 36.851749] [ 36.851749] the existing dependency chain (in reverse order) is: [ 36.859656] [ 36.859656] -> #2 (rtnl_mutex){+.+.}: [ 36.864933] __mutex_lock+0xc4/0x1310 [ 36.869415] unregister_netdevice_notifier+0x5e/0x2b0 [ 36.875227] tee_tg_destroy+0x5c/0xb0 [ 36.879550] cleanup_entry+0x1fd/0x2d0 [ 36.884071] __do_replace+0x38d/0x570 [ 36.888465] do_ipt_set_ctl+0x256/0x39e [ 36.893091] nf_setsockopt+0x5f/0xb0 [ 36.897400] ip_setsockopt+0x94/0xb0 [ 36.901621] udp_setsockopt+0x45/0x80 [ 36.905925] SyS_setsockopt+0x110/0x1e0 [ 36.910411] do_syscall_64+0x1d5/0x640 [ 36.914807] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 36.920496] [ 36.920496] -> #1 (&xt[i].mutex){+.+.}: [ 36.926056] __mutex_lock+0xc4/0x1310 [ 36.930364] xt_find_revision+0x88/0x200 [ 36.934931] nfnl_compat_get+0x1f7/0x870 [ 36.939498] nfnetlink_rcv_msg+0x9bb/0xc00 [ 36.944334] netlink_rcv_skb+0x125/0x390 [ 36.948908] nfnetlink_rcv+0x1ab/0x1da0 [ 36.953392] netlink_unicast+0x437/0x610 [ 36.957961] netlink_sendmsg+0x62e/0xb80 [ 36.963824] sock_sendmsg+0xb5/0x100 [ 36.968046] ___sys_sendmsg+0x6c8/0x800 [ 36.972533] __sys_sendmsg+0xa3/0x120 [ 36.976837] SyS_sendmsg+0x27/0x40 [ 36.980896] do_syscall_64+0x1d5/0x640 [ 36.985294] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 36.991015] [ 36.991015] -> #0 (&table[i].mutex){+.+.}: [ 36.996765] lock_acquire+0x170/0x3f0 [ 37.001074] __mutex_lock+0xc4/0x1310 [ 37.005381] nf_tables_netdev_event+0x10d/0x4d0 [ 37.010555] notifier_call_chain+0x108/0x1a0 [ 37.015468] rollback_registered_many+0x70b/0xb30 [ 37.020814] unregister_netdevice_many.part.0+0x18/0x2e0 [ 37.026774] unregister_netdevice_many+0x36/0x50 [ 37.032038] ip6gre_exit_net+0x41e/0x570 [ 37.036605] ops_exit_list+0xa5/0x150 [ 37.040909] cleanup_net+0x3b3/0x840 [ 37.045393] process_one_work+0x793/0x14a0 [ 37.050139] worker_thread+0x5cc/0xff0 [ 37.054530] kthread+0x30d/0x420 [ 37.058405] ret_from_fork+0x24/0x30 [ 37.062621] [ 37.062621] other info that might help us debug this: [ 37.062621] [ 37.070744] Chain exists of: [ 37.070744] &table[i].mutex --> &xt[i].mutex --> rtnl_mutex [ 37.070744] [ 37.081091] Possible unsafe locking scenario: [ 37.081091] [ 37.087247] CPU0 CPU1 [ 37.092049] ---- ---- [ 37.097656] lock(rtnl_mutex); [ 37.100920] lock(&xt[i].mutex); [ 37.107003] lock(rtnl_mutex); [ 37.112791] lock(&table[i].mutex); [ 37.116489] [ 37.116489] *** DEADLOCK *** [ 37.116489] [ 37.122705] 4 locks held by kworker/u4:5/6312: [ 37.127393] #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 [ 37.136412] #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x6e6/0x14a0 [ 37.146024] #2: (net_mutex){+.+.}, at: [] cleanup_net+0x110/0x840 [ 37.155603] #3: (rtnl_mutex){+.+.}, at: [] ip6gre_exit_net+0x70/0x570 [ 37.164211] [ 37.164211] stack backtrace: [ 37.168858] CPU: 1 PID: 6312 Comm: kworker/u4:5 Not tainted 4.14.195-syzkaller #0 [ 37.176674] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 37.186031] Workqueue: netns cleanup_net [ 37.190088] Call Trace: [ 37.192843] dump_stack+0x1b2/0x283 [ 37.196469] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 37.202263] __lock_acquire+0x2e0e/0x3f20 [ 37.206406] ? unwind_next_frame+0x404/0x17d0 [ 37.206414] ? trace_hardirqs_on+0x10/0x10 [ 37.206420] ? check_usage_forwards+0x2d0/0x2d0 [ 37.206430] ? ret_from_fork+0x24/0x30 [ 37.206439] lock_acquire+0x170/0x3f0 [ 37.206448] ? nf_tables_netdev_event+0x10d/0x4d0 [ 37.206455] ? nf_tables_netdev_event+0x10d/0x4d0 [ 37.206461] __mutex_lock+0xc4/0x1310 [ 37.206467] ? nf_tables_netdev_event+0x10d/0x4d0 [ 37.206474] ? nf_tables_netdev_event+0x10d/0x4d0 [ 37.206480] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 37.206487] ? trace_hardirqs_on+0x10/0x10 [ 37.206493] ? trace_hardirqs_on_caller+0x3a8/0x580 [ 37.206501] ? lock_downgrade+0x740/0x740 [ 37.206507] nf_tables_netdev_event+0x10d/0x4d0 [ 37.206517] ? mirred_device_event+0x12f/0x170 [ 37.279566] ? nf_tables_netdev_init_net+0x140/0x140 [ 37.284717] ? mirred_device_event+0x12f/0x170 [ 37.289291] ? __local_bh_enable_ip+0xc1/0x170 [ 37.293992] notifier_call_chain+0x108/0x1a0 [ 37.298508] rollback_registered_many+0x70b/0xb30 [ 37.303416] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 37.308988] ? dev_set_mac_address+0x2d0/0x2d0 [ 37.313568] ? lock_acquire+0x170/0x3f0 [ 37.317533] unregister_netdevice_many.part.0+0x18/0x2e0 [ 37.322971] unregister_netdevice_many+0x36/0x50 [ 37.327717] ip6gre_exit_net+0x41e/0x570 [ 37.332038] ? lock_downgrade+0x740/0x740 [ 37.336317] ? ip6gre_dellink+0x260/0x260 [ 37.340528] ? ip6gre_dellink+0x260/0x260 [ 37.344665] ops_exit_list+0xa5/0x150 [ 37.348452] cleanup_net+0x3b3/0x840 [ 37.352151] ? net_drop_ns+0x70/0x70 [ 37.356489] ? lock_acquire+0x170/0x3f0 [ 37.360534] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 37.366059] process_one_work+0x793/0x14a0 [ 37.370280] ? work_busy+0x320/0x320 [ 37.374074] ? worker_thread+0x158/0xff0 [ 37.378127] ? _raw_spin_unlock_irq+0x24/0x80 [ 37.382607] worker_thread+0x5cc/0xff0 [ 37.386606] ? rescuer_thread+0xc80/0xc80 [ 37.390742] kthread+0x30d/0x420 [ 37.394186] ? kthread_create_on_node+0xd0/0xd0 [ 37.398840] ret_from_fork+0x24/0x30 [ 37.961879] IPVS: ftp: loaded support on port[0] = 21 [ 37.991476] ip_tables: iptables: counters copy to user failed while replacing table [ 38.001848] IPVS: ftp: loaded support on port[0] = 21 [ 38.032987] ip_tables: iptables: counters copy to user failed while replacing table [ 38.640833] IPVS: ftp: loaded support on port[0] = 21 [ 38.671759] ip_tables: iptables: counters copy to user failed while replacing table [ 39.687641] IPVS: ftp: loaded support on port[0] = 21 [ 39.720192] ip_tables: iptables: counters copy to user failed while replacing table [ 40.330661] IPVS: ftp: loaded support on port[0] = 21 [ 40.359925] ip_tables: iptables: counters copy to user failed while replacing table [ 40.370238] IPVS: ftp: loaded support on port[0] = 21 [ 40.401493] ip_tables: iptables: counters copy to user failed while replacing table [ 41.009641] IPVS: ftp: loaded support on port[0] = 21 [ 41.039005] ip_tables: iptables: counters copy to user failed while replacing table [ 42.113220] IPVS: ftp: loaded support on port[0] = 21 [ 42.143113] ip_tables: iptables: counters copy to user failed while replacing table [ 42.808893] IPVS: ftp: loaded support on port[0] = 21 [ 42.838354] ip_tables: iptables: counters copy to user failed while replacing table [ 43.519225] IPVS: ftp: loaded support on port[0] = 21 [ 43.548590] ip_tables: iptables: counters copy to user failed while replacing table [ 43.558906] IPVS: ftp: loaded support on port[0] = 21 [ 43.595075] ip_tables: iptables: counters copy to user failed while replacing table [ 44.218203] IPVS: ftp: loaded support on port[0] = 21 [ 44.255018] ip_tables: iptables: counters copy to user failed while replacing table [ 45.364869] IPVS: ftp: loaded support on port[0] = 21 [ 45.394994] ip_tables: iptables: counters copy to user failed while replacing table [ 46.011530] IPVS: ftp: loaded support on port[0] = 21 [ 46.041134] ip_tables: iptables: counters copy to user failed while replacing table [ 46.051442] IPVS: ftp: loaded support on port[0] = 21 [ 46.082942] ip_tables: iptables: counters copy to user failed while replacing table [ 46.718419] IPVS: ftp: loaded support on port[0] = 21 [ 46.748624] ip_tables: iptables: counters copy to user failed while replacing table [ 46.759278] IPVS: ftp: loaded support on port[0] = 21