[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 25.464916] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 27.763099] random: sshd: uninitialized urandom read (32 bytes read) [ 28.122872] random: sshd: uninitialized urandom read (32 bytes read) [ 28.762869] random: sshd: uninitialized urandom read (32 bytes read) [ 159.917763] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.59' (ECDSA) to the list of known hosts. [ 165.596816] random: sshd: uninitialized urandom read (32 bytes read) 2018/09/21 16:16:38 parsed 1 programs [ 166.804392] random: cc1: uninitialized urandom read (8 bytes read) 2018/09/21 16:16:40 executed programs: 0 [ 168.189106] IPVS: ftp: loaded support on port[0] = 21 [ 168.441924] bridge0: port 1(bridge_slave_0) entered blocking state [ 168.448871] bridge0: port 1(bridge_slave_0) entered disabled state [ 168.456844] device bridge_slave_0 entered promiscuous mode [ 168.475517] bridge0: port 2(bridge_slave_1) entered blocking state [ 168.481937] bridge0: port 2(bridge_slave_1) entered disabled state [ 168.489214] device bridge_slave_1 entered promiscuous mode [ 168.507529] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 168.525242] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 168.575581] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 168.596413] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 168.671821] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 168.679940] team0: Port device team_slave_0 added [ 168.696447] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 168.703620] team0: Port device team_slave_1 added [ 168.720199] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 168.741047] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 168.759878] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 168.780734] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 168.927589] bridge0: port 2(bridge_slave_1) entered blocking state [ 168.934148] bridge0: port 2(bridge_slave_1) entered forwarding state [ 168.941014] bridge0: port 1(bridge_slave_0) entered blocking state [ 168.947392] bridge0: port 1(bridge_slave_0) entered forwarding state [ 169.460146] 8021q: adding VLAN 0 to HW filter on device bond0 [ 169.512561] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 169.563038] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 169.569305] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 169.576226] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 169.628560] 8021q: adding VLAN 0 to HW filter on device team0 [ 169.989329] netlink: 'syz-executor0': attribute type 1 has an invalid length. [ 170.006511] netlink: 'syz-executor0': attribute type 1 has an invalid length. [ 170.014874] [ 170.016854] ====================================================== [ 170.023151] WARNING: possible circular locking dependency detected [ 170.029460] 4.19.0-rc4+ #248 Not tainted [ 170.033654] ------------------------------------------------------ [ 170.039952] syz-executor0/5603 is trying to acquire lock: [ 170.045463] 00000000b6958801 ((wq_completion)bond_dev->name){+.+.}, at: flush_workqueue+0x2db/0x1e10 [ 170.054850] [ 170.054850] but task is already holding lock: [ 170.062108] 00000000402ca962 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x40e/0xc20 [ 170.071265] [ 170.071265] which lock already depends on the new lock. [ 170.071265] [ 170.079564] [ 170.079564] the existing dependency chain (in reverse order) is: [ 170.087164] [ 170.087164] -> #2 (rtnl_mutex){+.+.}: [ 170.092433] __mutex_lock+0x166/0x1700 [ 170.096883] mutex_lock_nested+0x16/0x20 [ 170.101458] rtnl_lock+0x17/0x20 [ 170.105395] bond_netdev_notify_work+0x44/0xd0 [ 170.110593] process_one_work+0xc90/0x1b90 [ 170.115582] worker_thread+0x17f/0x1390 [ 170.120058] kthread+0x35a/0x420 [ 170.123927] ret_from_fork+0x3a/0x50 [ 170.128137] [ 170.128137] -> #1 ((work_completion)(&(&nnw->work)->work)){+.+.}: [ 170.135844] process_one_work+0xc0a/0x1b90 [ 170.140585] worker_thread+0x17f/0x1390 [ 170.145068] kthread+0x35a/0x420 [ 170.149033] ret_from_fork+0x3a/0x50 [ 170.153251] [ 170.153251] -> #0 ((wq_completion)bond_dev->name){+.+.}: [ 170.160223] lock_acquire+0x1ed/0x520 [ 170.164537] flush_workqueue+0x30a/0x1e10 [ 170.169188] drain_workqueue+0x2a9/0x640 [ 170.173861] destroy_workqueue+0xc6/0x9c0 [ 170.178514] __alloc_workqueue_key+0xed8/0x1170 [ 170.183764] bond_init+0x274/0x970 [ 170.187820] register_netdevice+0x332/0x10f0 [ 170.192759] bond_newlink+0x49/0xa0 [ 170.196917] rtnl_newlink+0xec6/0x1d40 [ 170.201310] rtnetlink_rcv_msg+0x46a/0xc20 [ 170.206063] netlink_rcv_skb+0x172/0x440 [ 170.210637] rtnetlink_rcv+0x1c/0x20 [ 170.214876] netlink_unicast+0x5a5/0x760 [ 170.219467] netlink_sendmsg+0xa18/0xfc0 [ 170.224055] sock_sendmsg+0xd5/0x120 [ 170.228285] ___sys_sendmsg+0x7fd/0x930 [ 170.232777] __sys_sendmsg+0x11d/0x280 [ 170.237194] __x64_sys_sendmsg+0x78/0xb0 [ 170.241778] do_syscall_64+0x1b9/0x820 [ 170.246170] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 170.251877] [ 170.251877] other info that might help us debug this: [ 170.251877] [ 170.260027] Chain exists of: [ 170.260027] (wq_completion)bond_dev->name --> (work_completion)(&(&nnw->work)->work) --> rtnl_mutex [ 170.260027] [ 170.273722] Possible unsafe locking scenario: [ 170.273722] [ 170.279760] CPU0 CPU1 [ 170.284436] ---- ---- [ 170.289117] lock(rtnl_mutex); [ 170.292378] lock((work_completion)(&(&nnw->work)->work)); [ 170.300611] lock(rtnl_mutex); [ 170.306389] lock((wq_completion)bond_dev->name); [ 170.311312] [ 170.311312] *** DEADLOCK *** [ 170.311312] [ 170.317359] 1 lock held by syz-executor0/5603: [ 170.321926] #0: 00000000402ca962 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x40e/0xc20 [ 170.330100] [ 170.330100] stack backtrace: [ 170.334583] CPU: 1 PID: 5603 Comm: syz-executor0 Not tainted 4.19.0-rc4+ #248 [ 170.341837] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 170.351171] Call Trace: [ 170.353746] dump_stack+0x1c4/0x2b4 [ 170.357360] ? dump_stack_print_info.cold.2+0x52/0x52 [ 170.362537] ? vprintk_func+0x85/0x181 [ 170.366419] print_circular_bug.isra.33.cold.54+0x1bd/0x27d [ 170.372112] ? save_trace+0xe0/0x290 [ 170.375811] __lock_acquire+0x33e4/0x4ec0 [ 170.379945] ? mark_held_locks+0x130/0x130 [ 170.384177] ? select_idle_sibling+0x986/0xe80 [ 170.388746] ? __lock_is_held+0xb5/0x140 [ 170.392797] ? select_task_rq_fair+0x754/0x34f0 [ 170.397462] lock_acquire+0x1ed/0x520 [ 170.401250] ? flush_workqueue+0x2db/0x1e10 [ 170.405579] ? lock_release+0x970/0x970 [ 170.409583] ? lockdep_init_map+0x9/0x10 [ 170.413638] ? __init_waitqueue_head+0x9e/0x150 [ 170.418299] ? init_wait_entry+0x1c0/0x1c0 [ 170.422534] flush_workqueue+0x30a/0x1e10 [ 170.426665] ? flush_workqueue+0x2db/0x1e10 [ 170.430998] ? lock_acquire+0x1ed/0x520 [ 170.434961] ? drain_workqueue+0xa9/0x640 [ 170.439097] ? lock_release+0x970/0x970 [ 170.443059] ? flush_rcu_work+0x90/0x90 [ 170.447020] ? graph_lock+0x170/0x170 [ 170.450804] ? __mutex_lock+0x85e/0x1700 [ 170.454865] ? rcu_read_lock_sched_held+0x108/0x120 [ 170.459881] ? drain_workqueue+0xa9/0x640 [ 170.464127] ? graph_lock+0x170/0x170 [ 170.467919] ? find_held_lock+0x36/0x1c0 [ 170.471991] ? drain_workqueue+0x13f/0x640 [ 170.476212] ? lock_downgrade+0x900/0x900 [ 170.480347] ? graph_lock+0x170/0x170 [ 170.484134] ? find_held_lock+0x36/0x1c0 [ 170.488184] ? kasan_check_write+0x14/0x20 [ 170.492417] ? __mutex_unlock_slowpath+0x197/0x8c0 [ 170.497331] ? wait_for_completion+0x8a0/0x8a0 [ 170.501916] ? do_raw_spin_unlock+0xa7/0x2f0 [ 170.506339] drain_workqueue+0x2a9/0x640 [ 170.510397] ? drain_workqueue+0x2a9/0x640 [ 170.514626] ? flush_workqueue+0x1e10/0x1e10 [ 170.519018] ? save_stack+0xa9/0xd0 [ 170.522627] ? save_stack+0x43/0xd0 [ 170.526245] ? __kasan_slab_free+0x102/0x150 [ 170.530728] ? kasan_slab_free+0xe/0x10 [ 170.534685] ? kfree+0xcf/0x230 [ 170.537950] ? print_usage_bug+0xc0/0xc0 [ 170.542018] ? register_netdevice+0x332/0x10f0 [ 170.546603] ? bond_newlink+0x49/0xa0 [ 170.550388] ? rtnl_newlink+0xec6/0x1d40 [ 170.554520] ? rtnetlink_rcv_msg+0x46a/0xc20 [ 170.558919] ? netlink_rcv_skb+0x172/0x440 [ 170.563163] ? rtnetlink_rcv+0x1c/0x20 [ 170.567044] ? netlink_unicast+0x5a5/0x760 [ 170.571296] ? netlink_sendmsg+0xa18/0xfc0 [ 170.575526] ? sock_sendmsg+0xd5/0x120 [ 170.579400] destroy_workqueue+0xc6/0x9c0 [ 170.583543] ? kasan_check_write+0x14/0x20 [ 170.587782] ? wq_watchdog_timer_fn+0x810/0x810 [ 170.592440] ? mark_held_locks+0xc7/0x130 [ 170.596585] ? kfree+0x107/0x230 [ 170.599963] ? kfree+0x107/0x230 [ 170.603317] ? lockdep_hardirqs_on+0x421/0x5c0 [ 170.607885] ? trace_hardirqs_on+0xbd/0x310 [ 170.612196] ? init_rescuer.part.25+0x155/0x190 [ 170.616853] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 170.622341] ? __kasan_slab_free+0x119/0x150 [ 170.626760] ? init_rescuer.part.25+0x155/0x190 [ 170.631436] __alloc_workqueue_key+0xed8/0x1170 [ 170.636093] ? workqueue_sysfs_register+0x3f0/0x3f0 [ 170.641104] ? put_dec+0xf0/0xf0 [ 170.644459] ? format_decode+0x1b2/0xaf0 [ 170.648504] ? set_precision+0xe0/0xe0 [ 170.652380] ? simple_strtoll+0xa0/0xa0 [ 170.656342] ? graph_lock+0x170/0x170 [ 170.660134] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 170.665669] ? find_held_lock+0x36/0x1c0 [ 170.669750] ? lock_downgrade+0x900/0x900 [ 170.673887] ? check_preemption_disabled+0x48/0x200 [ 170.678898] ? rcu_read_unlock_special.part.39+0x11f0/0x11f0 [ 170.684685] ? kasan_check_read+0x11/0x20 [ 170.688819] ? rcu_dynticks_curr_cpu_in_eqs+0x9f/0x160 [ 170.694082] ? rcu_bh_qs+0xc0/0xc0 [ 170.697608] bond_init+0x274/0x970 [ 170.701137] ? __dev_get_by_name+0x170/0x170 [ 170.705529] ? bond_set_rx_mode+0x560/0x560 [ 170.709833] ? rtnl_is_locked+0xb5/0xf0 [ 170.713794] ? bond_set_rx_mode+0x560/0x560 [ 170.718108] register_netdevice+0x332/0x10f0 [ 170.722504] ? netdev_change_features+0x110/0x110 [ 170.727338] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 170.732860] ? ns_capable_common+0x13f/0x170 [ 170.737258] bond_newlink+0x49/0xa0 [ 170.740873] ? bond_changelink+0x2370/0x2370 [ 170.745290] rtnl_newlink+0xec6/0x1d40 [ 170.749169] ? rtnl_link_unregister+0x390/0x390 [ 170.753823] ? print_usage_bug+0xc0/0xc0 [ 170.757894] ? __lock_acquire+0x7ec/0x4ec0 [ 170.762142] ? print_usage_bug+0xc0/0xc0 [ 170.766194] ? print_usage_bug+0xc0/0xc0 [ 170.770240] ? mark_held_locks+0x130/0x130 [ 170.774461] ? __lock_acquire+0x7ec/0x4ec0 [ 170.778683] ? lock_acquire+0x1ed/0x520 [ 170.782642] ? rtnetlink_rcv_msg+0x40e/0xc20 [ 170.787059] ? lock_release+0x970/0x970 [ 170.791025] ? arch_local_save_flags+0x40/0x40 [ 170.795621] ? mutex_trylock+0x2b0/0x2b0 [ 170.799673] ? __lock_acquire+0x7ec/0x4ec0 [ 170.804003] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 170.809552] ? refcount_sub_and_test_checked+0x203/0x310 [ 170.815022] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 170.820544] ? rtnl_get_link+0x170/0x370 [ 170.824611] ? rtnl_dump_all+0x600/0x600 [ 170.828663] ? kasan_check_read+0x11/0x20 [ 170.832795] ? rcu_dynticks_curr_cpu_in_eqs+0x9f/0x160 [ 170.838061] ? ns_capable_common+0x13f/0x170 [ 170.842460] ? rtnl_link_unregister+0x390/0x390 [ 170.847116] rtnetlink_rcv_msg+0x46a/0xc20 [ 170.851339] ? rtnetlink_put_metrics+0x690/0x690 [ 170.856085] netlink_rcv_skb+0x172/0x440 [ 170.860142] ? rtnetlink_put_metrics+0x690/0x690 [ 170.865057] ? netlink_ack+0xb80/0xb80 [ 170.868930] rtnetlink_rcv+0x1c/0x20 [ 170.872637] netlink_unicast+0x5a5/0x760 [ 170.876697] ? netlink_attachskb+0x9a0/0x9a0 [ 170.881113] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 170.886640] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 170.891643] netlink_sendmsg+0xa18/0xfc0 [ 170.895693] ? netlink_unicast+0x760/0x760 [ 170.899920] ? aa_sock_msg_perm.isra.12+0xba/0x160 [ 170.904836] ? apparmor_socket_sendmsg+0x29/0x30 [ 170.909578] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 170.915098] ? security_socket_sendmsg+0x94/0xc0 [ 170.919862] ? netlink_unicast+0x760/0x760 [ 170.924084] sock_sendmsg+0xd5/0x120 [ 170.927791] ___sys_sendmsg+0x7fd/0x930 [ 170.931759] ? copy_msghdr_from_user+0x580/0x580 [ 170.936502] ? __fd_install+0x2b5/0x8f0 [ 170.940483] ? check_preemption_disabled+0x48/0x200 [ 170.945489] ? __fget_light+0x2e9/0x430 [ 170.949449] ? fget_raw+0x20/0x20 [ 170.952889] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 170.958439] ? __fd_install+0x2f9/0x8f0 [ 170.962401] ? get_unused_fd_flags+0x1a0/0x1a0 [ 170.966984] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 170.972505] ? sockfd_lookup_light+0xc5/0x160 [ 170.976986] __sys_sendmsg+0x11d/0x280 [ 170.980860] ? __ia32_sys_shutdown+0x80/0x80 [ 170.985258] ? __x64_sys_futex+0x47f/0x6a0 [ 170.989489] ? do_syscall_64+0x9a/0x820 [ 170.993462] ? do_syscall_64+0x9a/0x820 [ 170.997429] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 171.002880] ? trace_hardirqs_off+0xb8/0x310 [ 171.007289] __x64_sys_sendmsg+0x78/0xb0 [ 171.011343] do_syscall_64+0x1b9/0x820 [ 171.015217] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 171.020568] ? syscall_return_slowpath+0x5e0/0x5e0 [ 171.025485] ? trace_hardirqs_on_caller+0x310/0x310 [ 171.030488] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 171.035490] ? recalc_sigpending_tsk+0x180/0x180 [ 171.040243] ? kasan_check_write+0x14/0x20 [ 171.044478] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 171.049307] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 171.054480] RIP: 0033:0x457679 [ 171.057659] Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 171.076559] RSP: 002b:00007f82d5832c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 171.084281] RAX: ffffffffffffffda RBX: 00007f82d58336d4 RCX: 0000000000457679 [ 171.091571] RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004 [ 171.098825] RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 [ 171.106079] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff [ 171.113351] R13: 00000000004d5538 R14: 00000000004c38e7 R15: 0000000000000000 [ 171.130805] kobject: 'loop0' (00000000e35d1a34): kobject_uevent_env [ 171.138420] kobject: 'loop0' (00000000e35d1a34): fill_kobj_path: