[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.967680] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.035185] random: sshd: uninitialized urandom read (32 bytes read) [ 25.334985] random: sshd: uninitialized urandom read (32 bytes read) [ 25.868210] random: sshd: uninitialized urandom read (32 bytes read) [ 26.989072] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.53' (ECDSA) to the list of known hosts. [ 32.501900] random: sshd: uninitialized urandom read (32 bytes read) 2018/09/07 21:13:50 parsed 1 programs [ 33.558110] random: cc1: uninitialized urandom read (8 bytes read) 2018/09/07 21:13:52 executed programs: 0 [ 34.922738] IPVS: ftp: loaded support on port[0] = 21 [ 35.136255] bridge0: port 1(bridge_slave_0) entered blocking state [ 35.142898] bridge0: port 1(bridge_slave_0) entered disabled state [ 35.150255] device bridge_slave_0 entered promiscuous mode [ 35.168161] bridge0: port 2(bridge_slave_1) entered blocking state [ 35.174553] bridge0: port 2(bridge_slave_1) entered disabled state [ 35.181645] device bridge_slave_1 entered promiscuous mode [ 35.198069] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 35.214613] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 35.258778] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 35.277757] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 35.342823] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 35.350425] team0: Port device team_slave_0 added [ 35.366097] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 35.373197] team0: Port device team_slave_1 added [ 35.388715] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 35.405544] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 35.422167] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 35.439065] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 35.563508] bridge0: port 2(bridge_slave_1) entered blocking state [ 35.569970] bridge0: port 2(bridge_slave_1) entered forwarding state [ 35.576779] bridge0: port 1(bridge_slave_0) entered blocking state [ 35.583160] bridge0: port 1(bridge_slave_0) entered forwarding state [ 36.031397] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 36.037522] 8021q: adding VLAN 0 to HW filter on device bond0 [ 36.082279] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 36.125334] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 36.134417] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 36.140565] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 36.148517] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 36.188009] 8021q: adding VLAN 0 to HW filter on device team0 [ 36.473144] [ 36.474795] ====================================================== [ 36.481087] WARNING: possible circular locking dependency detected [ 36.487384] 4.19.0-rc2+ #226 Not tainted [ 36.491419] ------------------------------------------------------ [ 36.497723] syz-executor0/4564 is trying to acquire lock: [ 36.503236] 00000000eec46650 ((wq_completion)bond_dev->name){+.+.}, at: flush_workqueue+0x2db/0x1e10 [ 36.512501] [ 36.512501] but task is already holding lock: [ 36.518460] 00000000273935fd (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 [ 36.526156] [ 36.526156] which lock already depends on the new lock. [ 36.526156] [ 36.534451] [ 36.534451] the existing dependency chain (in reverse order) is: [ 36.542049] [ 36.542049] -> #2 (rtnl_mutex){+.+.}: [ 36.547331] __mutex_lock+0x171/0x1700 [ 36.551729] mutex_lock_nested+0x16/0x20 [ 36.556293] rtnl_lock+0x17/0x20 [ 36.560162] bond_netdev_notify_work+0x44/0xd0 [ 36.565248] process_one_work+0xc73/0x1aa0 [ 36.569987] worker_thread+0x189/0x13c0 [ 36.574463] kthread+0x35a/0x420 [ 36.578335] ret_from_fork+0x3a/0x50 [ 36.582546] [ 36.582546] -> #1 ((work_completion)(&(&nnw->work)->work)){+.+.}: [ 36.590377] process_one_work+0xc0b/0x1aa0 [ 36.595132] worker_thread+0x189/0x13c0 [ 36.599634] kthread+0x35a/0x420 [ 36.603513] ret_from_fork+0x3a/0x50 [ 36.607731] [ 36.607731] -> #0 ((wq_completion)bond_dev->name){+.+.}: [ 36.614656] lock_acquire+0x1e4/0x4f0 [ 36.618963] flush_workqueue+0x30a/0x1e10 [ 36.623620] drain_workqueue+0x2a9/0x640 [ 36.628192] destroy_workqueue+0xc6/0x9d0 [ 36.632846] __alloc_workqueue_key+0xef9/0x1190 [ 36.638025] bond_init+0x269/0x940 [ 36.642074] register_netdevice+0x337/0x1100 [ 36.646994] bond_newlink+0x49/0xa0 [ 36.651141] rtnl_newlink+0xef4/0x1d50 [ 36.655537] rtnetlink_rcv_msg+0x46e/0xc30 [ 36.660278] netlink_rcv_skb+0x172/0x440 [ 36.664838] rtnetlink_rcv+0x1c/0x20 [ 36.669051] netlink_unicast+0x5a0/0x760 [ 36.673612] netlink_sendmsg+0xa18/0xfc0 [ 36.678179] sock_sendmsg+0xd5/0x120 [ 36.682506] ___sys_sendmsg+0x7fd/0x930 [ 36.687034] __sys_sendmsg+0x11d/0x290 [ 36.691438] __x64_sys_sendmsg+0x78/0xb0 [ 36.696011] do_syscall_64+0x1b9/0x820 [ 36.700405] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 36.706091] [ 36.706091] other info that might help us debug this: [ 36.706091] [ 36.714221] Chain exists of: [ 36.714221] (wq_completion)bond_dev->name --> (work_completion)(&(&nnw->work)->work) --> rtnl_mutex [ 36.714221] [ 36.728055] Possible unsafe locking scenario: [ 36.728055] [ 36.734098] CPU0 CPU1 [ 36.738749] ---- ---- [ 36.743395] lock(rtnl_mutex); [ 36.746659] lock((work_completion)(&(&nnw->work)->work)); [ 36.754974] lock(rtnl_mutex); [ 36.760754] lock((wq_completion)bond_dev->name); [ 36.765673] [ 36.765673] *** DEADLOCK *** [ 36.765673] [ 36.771732] 1 lock held by syz-executor0/4564: [ 36.776294] #0: 00000000273935fd (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 [ 36.784444] [ 36.784444] stack backtrace: [ 36.789030] CPU: 0 PID: 4564 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #226 [ 36.796297] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.805771] Call Trace: [ 36.808348] dump_stack+0x1c9/0x2b4 [ 36.811957] ? dump_stack_print_info.cold.2+0x52/0x52 [ 36.817129] ? vprintk_func+0x81/0x117 [ 36.821113] print_circular_bug.isra.34.cold.55+0x1bd/0x27d [ 36.826810] ? save_trace+0xe0/0x290 [ 36.830514] __lock_acquire+0x3449/0x5020 [ 36.834660] ? mark_held_locks+0x160/0x160 [ 36.838884] ? __lock_is_held+0xb5/0x140 [ 36.842937] ? update_curr+0x344/0xba0 [ 36.846864] ? __account_cfs_rq_runtime+0x770/0x770 [ 36.851873] ? lock_downgrade+0x8f0/0x8f0 [ 36.856006] lock_acquire+0x1e4/0x4f0 [ 36.859795] ? flush_workqueue+0x2db/0x1e10 [ 36.864125] ? lock_release+0x9f0/0x9f0 [ 36.868181] ? lockdep_init_map+0x9/0x10 [ 36.872230] ? __init_waitqueue_head+0x9e/0x150 [ 36.876884] ? init_wait_entry+0x1c0/0x1c0 [ 36.881110] flush_workqueue+0x30a/0x1e10 [ 36.885248] ? flush_workqueue+0x2db/0x1e10 [ 36.889558] ? lock_acquire+0x1e4/0x4f0 [ 36.893521] ? drain_workqueue+0xa9/0x640 [ 36.897655] ? lock_release+0x9f0/0x9f0 [ 36.901616] ? check_same_owner+0x340/0x340 [ 36.905919] ? task_numa_migrate+0x28e0/0x28e0 [ 36.910485] ? __queue_delayed_work+0x390/0x390 [ 36.915139] ? graph_lock+0x170/0x170 [ 36.918923] ? kasan_check_write+0x14/0x20 [ 36.923146] ? __mutex_lock+0x6d0/0x1700 [ 36.927190] ? drain_workqueue+0xa9/0x640 [ 36.931318] ? graph_lock+0x170/0x170 [ 36.935104] ? print_usage_bug+0xc0/0xc0 [ 36.939158] ? find_held_lock+0x36/0x1c0 [ 36.943203] ? lock_downgrade+0x8f0/0x8f0 [ 36.947384] ? graph_lock+0x170/0x170 [ 36.951170] ? graph_lock+0x170/0x170 [ 36.954951] ? find_held_lock+0x36/0x1c0 [ 36.958994] ? kasan_check_write+0x14/0x20 [ 36.963208] ? __mutex_unlock_slowpath+0x197/0x8c0 [ 36.968120] ? wait_for_completion+0x8d0/0x8d0 [ 36.972688] ? do_raw_spin_unlock+0xa7/0x2f0 [ 36.977081] ? trace_hardirqs_on+0x2c0/0x2c0 [ 36.981478] drain_workqueue+0x2a9/0x640 [ 36.985522] ? drain_workqueue+0x2a9/0x640 [ 36.989761] ? flush_workqueue+0x1e10/0x1e10 [ 36.994162] ? save_stack+0xa9/0xd0 [ 36.997782] ? save_stack+0x43/0xd0 [ 37.001393] ? __kasan_slab_free+0x11a/0x170 [ 37.005789] ? kasan_slab_free+0xe/0x10 [ 37.009748] ? print_usage_bug+0xc0/0xc0 [ 37.013834] ? bond_init+0x269/0x940 [ 37.017539] ? register_netdevice+0x337/0x1100 [ 37.022106] ? bond_newlink+0x49/0xa0 [ 37.025890] ? rtnl_newlink+0xef4/0x1d50 [ 37.029930] ? rtnetlink_rcv_msg+0x46e/0xc30 [ 37.034319] ? netlink_rcv_skb+0x172/0x440 [ 37.038530] ? rtnetlink_rcv+0x1c/0x20 [ 37.042405] ? netlink_unicast+0x5a0/0x760 [ 37.046765] ? netlink_sendmsg+0xa18/0xfc0 [ 37.050986] ? sock_sendmsg+0xd5/0x120 [ 37.054861] destroy_workqueue+0xc6/0x9d0 [ 37.058994] ? kasan_check_write+0x14/0x20 [ 37.063211] ? wq_watchdog_timer_fn+0x830/0x830 [ 37.067870] ? mark_held_locks+0xc9/0x160 [ 37.072117] ? _raw_spin_unlock_irqrestore+0x63/0xc0 [ 37.077204] ? kfree+0x111/0x210 [ 37.080553] ? kfree+0x111/0x210 [ 37.083903] ? lockdep_hardirqs_on+0x421/0x5c0 [ 37.088467] ? trace_hardirqs_on+0xbd/0x2c0 [ 37.092771] ? init_rescuer.part.26+0x155/0x190 [ 37.097423] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 37.102509] ? __kasan_slab_free+0x131/0x170 [ 37.107073] ? init_rescuer.part.26+0x155/0x190 [ 37.111733] __alloc_workqueue_key+0xef9/0x1190 [ 37.116395] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 37.121923] ? workqueue_sysfs_register+0x3f0/0x3f0 [ 37.126931] ? put_dec+0xf0/0xf0 [ 37.130329] ? format_decode+0x1b1/0xaf0 [ 37.134385] ? set_precision+0xe0/0xe0 [ 37.138258] ? simple_strtoll+0xa0/0xa0 [ 37.142213] ? graph_lock+0x170/0x170 [ 37.146001] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 37.151525] ? vsnprintf+0x20d/0x1b60 [ 37.155317] ? find_held_lock+0x36/0x1c0 [ 37.159361] ? lock_downgrade+0x8f0/0x8f0 [ 37.163492] ? kasan_check_read+0x11/0x20 [ 37.167622] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 37.172271] bond_init+0x269/0x940 [ 37.175796] ? __dev_get_by_name+0x170/0x170 [ 37.180182] ? bond_arp_rcv+0x11c0/0x11c0 [ 37.184318] ? check_same_owner+0x340/0x340 [ 37.188625] ? rcu_note_context_switch+0x680/0x680 [ 37.193588] ? bond_arp_rcv+0x11c0/0x11c0 [ 37.197725] register_netdevice+0x337/0x1100 [ 37.202117] ? netdev_change_features+0x110/0x110 [ 37.206942] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 37.212460] ? ns_capable_common+0x13f/0x170 [ 37.216852] ? ns_capable+0x22/0x30 [ 37.220469] bond_newlink+0x49/0xa0 [ 37.224084] ? bond_changelink+0x2360/0x2360 [ 37.228481] rtnl_newlink+0xef4/0x1d50 [ 37.232355] ? rtnl_link_unregister+0x390/0x390 [ 37.237010] ? print_usage_bug+0xc0/0xc0 [ 37.241057] ? __lock_acquire+0x7fc/0x5020 [ 37.245276] ? print_usage_bug+0xc0/0xc0 [ 37.249478] ? graph_lock+0x170/0x170 [ 37.253263] ? print_usage_bug+0xc0/0xc0 [ 37.257307] ? mark_held_locks+0x160/0x160 [ 37.261524] ? __lock_acquire+0x7fc/0x5020 [ 37.265743] ? lock_acquire+0x1e4/0x4f0 [ 37.269708] ? rtnetlink_rcv_msg+0x412/0xc30 [ 37.274105] ? lock_release+0x9f0/0x9f0 [ 37.278070] ? check_same_owner+0x340/0x340 [ 37.282383] ? mutex_trylock+0x2b0/0x2b0 [ 37.286456] ? __lock_acquire+0x7fc/0x5020 [ 37.290725] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 37.296250] ? refcount_sub_and_test_checked+0x21a/0x350 [ 37.301696] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 37.307219] ? rtnl_get_link+0x170/0x370 [ 37.311326] ? rtnl_dump_all+0x600/0x600 [ 37.315374] ? rcu_is_watching+0x8c/0x150 [ 37.319507] ? rtnl_link_unregister+0x390/0x390 [ 37.324165] rtnetlink_rcv_msg+0x46e/0xc30 [ 37.328492] ? rtnetlink_put_metrics+0x690/0x690 [ 37.333241] netlink_rcv_skb+0x172/0x440 [ 37.337289] ? rtnetlink_put_metrics+0x690/0x690 [ 37.342022] ? netlink_ack+0xbe0/0xbe0 [ 37.345889] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 37.350548] rtnetlink_rcv+0x1c/0x20 [ 37.354246] netlink_unicast+0x5a0/0x760 [ 37.358288] ? netlink_attachskb+0x9a0/0x9a0 [ 37.362690] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 37.368211] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 37.373213] netlink_sendmsg+0xa18/0xfc0 [ 37.377262] ? netlink_unicast+0x760/0x760 [ 37.381575] ? aa_sock_msg_perm.isra.13+0xba/0x160 [ 37.386496] ? apparmor_socket_sendmsg+0x29/0x30 [ 37.391242] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 37.396766] ? security_socket_sendmsg+0x94/0xc0 [ 37.401502] ? netlink_unicast+0x760/0x760 [ 37.405774] sock_sendmsg+0xd5/0x120 [ 37.409485] ___sys_sendmsg+0x7fd/0x930 [ 37.413446] ? copy_msghdr_from_user+0x580/0x580 [ 37.418186] ? lock_downgrade+0x8f0/0x8f0 [ 37.422323] ? __fget_light+0x2f7/0x440 [ 37.426287] ? fget_raw+0x20/0x20 [ 37.429731] ? __fd_install+0x2db/0x880 [ 37.433693] ? get_unused_fd_flags+0x1a0/0x1a0 [ 37.438265] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 37.443840] ? sockfd_lookup_light+0xc5/0x160 [ 37.448331] __sys_sendmsg+0x11d/0x290 [ 37.452210] ? __ia32_sys_shutdown+0x80/0x80 [ 37.456611] ? __x64_sys_futex+0x47f/0x6a0 [ 37.460831] ? do_syscall_64+0x9a/0x820 [ 37.464793] ? do_syscall_64+0x9a/0x820 [ 37.468754] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 37.473844] ? trace_hardirqs_off+0xb8/0x2c0 [ 37.478240] __x64_sys_sendmsg+0x78/0xb0 [ 37.482284] do_syscall_64+0x1b9/0x820 [ 37.486155] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 37.491506] ? syscall_return_slowpath+0x5e0/0x5e0 [ 37.496425] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 37.501256] ? trace_hardirqs_on_caller+0x2c0/0x2c0 [ 37.506304] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 37.511314] ? prepare_exit_to_usermode+0x291/0x3b0 [ 37.516316] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 37.521148] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 37.526319] RIP: 0033:0x457099 [ 37.529498] Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 37.548384] RSP: 002b:00007ff9f874cc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 37.556073] RAX: ffffffffffffffda RBX: 00007ff9f874d6d4 RCX: 0000000000457099 [ 37.563326] RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004 [ 37.570579] RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 [ 37.577837] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff [ 37.585089] R13: 00000000004d4bf0 R14: 00000000004c9133 R15: 0000000000000000 2018/09/07 21:13:57 executed programs: 128 2018/09/07 21:14:02 executed programs: 391