[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 23.714414] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 27.242595] random: sshd: uninitialized urandom read (32 bytes read) [ 27.524669] random: sshd: uninitialized urandom read (32 bytes read) [ 28.077578] random: sshd: uninitialized urandom read (32 bytes read) [ 115.302277] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.52' (ECDSA) to the list of known hosts. [ 120.834588] random: sshd: uninitialized urandom read (32 bytes read) 2018/09/04 17:29:40 parsed 1 programs [ 122.116056] random: cc1: uninitialized urandom read (8 bytes read) 2018/09/04 17:29:42 executed programs: 0 [ 123.522815] IPVS: ftp: loaded support on port[0] = 21 [ 123.627934] ip (4707) used greatest stack depth: 17000 bytes left [ 123.746646] bridge0: port 1(bridge_slave_0) entered blocking state [ 123.753095] bridge0: port 1(bridge_slave_0) entered disabled state [ 123.760646] device bridge_slave_0 entered promiscuous mode [ 123.778467] bridge0: port 2(bridge_slave_1) entered blocking state [ 123.784966] bridge0: port 2(bridge_slave_1) entered disabled state [ 123.792353] device bridge_slave_1 entered promiscuous mode [ 123.809980] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 123.827236] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 123.874092] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 123.894148] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 123.965271] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 123.972974] team0: Port device team_slave_0 added [ 123.990320] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 123.997659] team0: Port device team_slave_1 added [ 124.014048] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 124.033079] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 124.052511] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 124.071404] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 124.205969] bridge0: port 2(bridge_slave_1) entered blocking state [ 124.212854] bridge0: port 2(bridge_slave_1) entered forwarding state [ 124.219932] bridge0: port 1(bridge_slave_0) entered blocking state [ 124.226669] bridge0: port 1(bridge_slave_0) entered forwarding state [ 124.709656] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 124.716033] 8021q: adding VLAN 0 to HW filter on device bond0 [ 124.722841] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 124.773088] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 124.823338] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 124.829655] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 124.837635] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 124.883896] 8021q: adding VLAN 0 to HW filter on device team0 [ 125.304608] [ 125.306571] ====================================================== [ 125.313184] WARNING: possible circular locking dependency detected [ 125.319635] 4.19.0-rc2+ #220 Not tainted [ 125.323689] ------------------------------------------------------ [ 125.330438] syz-executor0/4972 is trying to acquire lock: [ 125.336049] 00000000a432d798 ((wq_completion)bond_dev->name){+.+.}, at: flush_workqueue+0x2db/0x1e10 [ 125.345882] [ 125.345882] but task is already holding lock: [ 125.351846] 000000006d1321a4 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 [ 125.359920] [ 125.359920] which lock already depends on the new lock. [ 125.359920] [ 125.368379] [ 125.368379] the existing dependency chain (in reverse order) is: [ 125.376339] [ 125.376339] -> #2 (rtnl_mutex){+.+.}: [ 125.381766] __mutex_lock+0x171/0x1700 [ 125.386172] mutex_lock_nested+0x16/0x20 [ 125.390911] rtnl_lock+0x17/0x20 [ 125.394920] bond_netdev_notify_work+0x44/0xd0 [ 125.400277] process_one_work+0xc73/0x1aa0 [ 125.405234] worker_thread+0x189/0x13c0 [ 125.410155] kthread+0x35a/0x420 [ 125.414716] ret_from_fork+0x3a/0x50 [ 125.419471] [ 125.419471] -> #1 ((work_completion)(&(&nnw->work)->work)){+.+.}: [ 125.427901] process_one_work+0xc0b/0x1aa0 [ 125.432818] worker_thread+0x189/0x13c0 [ 125.437557] kthread+0x35a/0x420 [ 125.441446] ret_from_fork+0x3a/0x50 [ 125.446080] [ 125.446080] -> #0 ((wq_completion)bond_dev->name){+.+.}: [ 125.453031] lock_acquire+0x1e4/0x4f0 [ 125.457698] flush_workqueue+0x30a/0x1e10 [ 125.462368] drain_workqueue+0x2a9/0x640 [ 125.467394] destroy_workqueue+0xc6/0x9d0 [ 125.472064] __alloc_workqueue_key+0xef9/0x1190 [ 125.477401] bond_init+0x269/0x940 [ 125.481610] register_netdevice+0x337/0x1100 [ 125.486686] bond_newlink+0x49/0xa0 [ 125.491137] rtnl_newlink+0xef4/0x1d50 [ 125.495996] rtnetlink_rcv_msg+0x46e/0xc30 [ 125.500941] netlink_rcv_skb+0x172/0x440 [ 125.505742] rtnetlink_rcv+0x1c/0x20 [ 125.510217] netlink_unicast+0x5a0/0x760 [ 125.514960] netlink_sendmsg+0xa18/0xfc0 [ 125.519786] sock_sendmsg+0xd5/0x120 [ 125.524394] ___sys_sendmsg+0x7fd/0x930 [ 125.529350] __sys_sendmsg+0x11d/0x290 [ 125.533850] __x64_sys_sendmsg+0x78/0xb0 [ 125.538429] do_syscall_64+0x1b9/0x820 [ 125.543049] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 125.548751] [ 125.548751] other info that might help us debug this: [ 125.548751] [ 125.557101] Chain exists of: [ 125.557101] (wq_completion)bond_dev->name --> (work_completion)(&(&nnw->work)->work) --> rtnl_mutex [ 125.557101] [ 125.571253] Possible unsafe locking scenario: [ 125.571253] [ 125.577524] CPU0 CPU1 [ 125.582360] ---- ---- [ 125.587254] lock(rtnl_mutex); [ 125.590741] lock((work_completion)(&(&nnw->work)->work)); [ 125.599079] lock(rtnl_mutex); [ 125.604872] lock((wq_completion)bond_dev->name); [ 125.609949] [ 125.609949] *** DEADLOCK *** [ 125.609949] [ 125.616272] 1 lock held by syz-executor0/4972: [ 125.621524] #0: 000000006d1321a4 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 [ 125.630257] [ 125.630257] stack backtrace: [ 125.635065] CPU: 0 PID: 4972 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #220 [ 125.642634] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 125.652739] Call Trace: [ 125.655338] dump_stack+0x1c9/0x2b4 [ 125.659077] ? dump_stack_print_info.cold.2+0x52/0x52 [ 125.664404] ? vprintk_func+0x81/0x117 [ 125.668609] print_circular_bug.isra.34.cold.55+0x1bd/0x27d [ 125.675268] ? save_trace+0xe0/0x290 [ 125.679119] __lock_acquire+0x3449/0x5020 [ 125.683594] ? mark_held_locks+0x160/0x160 [ 125.687918] ? mark_held_locks+0x160/0x160 [ 125.692153] ? __lock_is_held+0xb5/0x140 [ 125.696586] ? __account_cfs_rq_runtime+0x770/0x770 [ 125.701753] ? set_next_entity+0x2f0/0xa80 [ 125.706332] lock_acquire+0x1e4/0x4f0 [ 125.710588] ? flush_workqueue+0x2db/0x1e10 [ 125.715198] ? lock_release+0x9f0/0x9f0 [ 125.719453] ? lockdep_init_map+0x9/0x10 [ 125.723526] ? __init_waitqueue_head+0x9e/0x150 [ 125.728222] ? init_wait_entry+0x1c0/0x1c0 [ 125.732835] flush_workqueue+0x30a/0x1e10 [ 125.737318] ? flush_workqueue+0x2db/0x1e10 [ 125.742022] ? lock_acquire+0x1e4/0x4f0 [ 125.745994] ? drain_workqueue+0xa9/0x640 [ 125.750401] ? lock_release+0x9f0/0x9f0 [ 125.754374] ? check_same_owner+0x340/0x340 [ 125.758834] ? __queue_delayed_work+0x390/0x390 [ 125.763500] ? graph_lock+0x170/0x170 [ 125.767300] ? kasan_check_write+0x14/0x20 [ 125.771852] ? __mutex_lock+0x6d0/0x1700 [ 125.776258] ? drain_workqueue+0xa9/0x640 [ 125.780501] ? finish_task_switch+0x2ca/0x870 [ 125.785775] ? find_held_lock+0x36/0x1c0 [ 125.789967] ? lock_downgrade+0x8f0/0x8f0 [ 125.794424] ? __schedule+0x884/0x1df0 [ 125.798431] ? graph_lock+0x170/0x170 [ 125.802228] ? find_held_lock+0x36/0x1c0 [ 125.806421] ? kasan_check_write+0x14/0x20 [ 125.810831] ? __mutex_unlock_slowpath+0x197/0x8c0 [ 125.816185] ? wait_for_completion+0x8d0/0x8d0 [ 125.821148] ? do_raw_spin_unlock+0xa7/0x2f0 [ 125.826002] ? trace_hardirqs_on+0x2c0/0x2c0 [ 125.831004] drain_workqueue+0x2a9/0x640 [ 125.835257] ? drain_workqueue+0x2a9/0x640 [ 125.839496] ? flush_workqueue+0x1e10/0x1e10 [ 125.843911] ? save_stack+0xa9/0xd0 [ 125.847557] ? save_stack+0x43/0xd0 [ 125.851343] ? __kasan_slab_free+0x11a/0x170 [ 125.855869] ? kasan_slab_free+0xe/0x10 [ 125.860151] ? print_usage_bug+0xc0/0xc0 [ 125.864424] ? bond_init+0x269/0x940 [ 125.868376] ? register_netdevice+0x337/0x1100 [ 125.873274] ? bond_newlink+0x49/0xa0 [ 125.877204] ? rtnl_newlink+0xef4/0x1d50 [ 125.881263] ? rtnetlink_rcv_msg+0x46e/0xc30 [ 125.885766] ? netlink_rcv_skb+0x172/0x440 [ 125.890389] ? rtnetlink_rcv+0x1c/0x20 [ 125.894403] ? netlink_unicast+0x5a0/0x760 [ 125.898857] ? netlink_sendmsg+0xa18/0xfc0 [ 125.903371] ? sock_sendmsg+0xd5/0x120 [ 125.907285] destroy_workqueue+0xc6/0x9d0 [ 125.911593] ? kasan_check_write+0x14/0x20 [ 125.916338] ? wq_watchdog_timer_fn+0x830/0x830 [ 125.921497] ? mark_held_locks+0xc9/0x160 [ 125.925836] ? _raw_spin_unlock_irqrestore+0x63/0xc0 [ 125.930965] ? kfree+0x111/0x210 [ 125.934589] ? kfree+0x111/0x210 [ 125.938052] ? lockdep_hardirqs_on+0x421/0x5c0 [ 125.943036] ? trace_hardirqs_on+0xbd/0x2c0 [ 125.947821] ? init_rescuer.part.26+0x155/0x190 [ 125.953008] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 125.958300] ? __kasan_slab_free+0x131/0x170 [ 125.962827] ? init_rescuer.part.26+0x155/0x190 [ 125.967800] __alloc_workqueue_key+0xef9/0x1190 [ 125.972805] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 125.978844] ? workqueue_sysfs_register+0x3f0/0x3f0 [ 125.984024] ? put_dec+0xf0/0xf0 [ 125.987570] ? format_decode+0x1b1/0xaf0 [ 125.991859] ? set_precision+0xe0/0xe0 [ 125.996051] ? simple_strtoll+0xa0/0xa0 [ 126.000156] ? graph_lock+0x170/0x170 [ 126.004425] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 126.010298] ? vsnprintf+0x20d/0x1b60 [ 126.014467] ? find_held_lock+0x36/0x1c0 [ 126.018591] ? lock_downgrade+0x8f0/0x8f0 [ 126.023033] ? kasan_check_read+0x11/0x20 [ 126.027302] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 126.032311] bond_init+0x269/0x940 [ 126.036164] ? __dev_get_by_name+0x170/0x170 [ 126.040703] ? bond_arp_rcv+0x11c0/0x11c0 [ 126.045032] ? check_same_owner+0x340/0x340 [ 126.049779] ? rcu_note_context_switch+0x680/0x680 [ 126.055611] ? bond_arp_rcv+0x11c0/0x11c0 [ 126.059959] register_netdevice+0x337/0x1100 [ 126.064807] ? netdev_change_features+0x110/0x110 [ 126.069651] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 126.075332] ? ns_capable_common+0x13f/0x170 [ 126.080053] bond_newlink+0x49/0xa0 [ 126.083756] ? bond_changelink+0x2360/0x2360 [ 126.088341] rtnl_newlink+0xef4/0x1d50 [ 126.092232] ? rtnl_link_unregister+0x390/0x390 [ 126.097589] ? print_usage_bug+0xc0/0xc0 [ 126.101969] ? __lock_acquire+0x7fc/0x5020 [ 126.106290] ? print_usage_bug+0xc0/0xc0 [ 126.110494] ? graph_lock+0x170/0x170 [ 126.114506] ? print_usage_bug+0xc0/0xc0 [ 126.118744] ? mark_held_locks+0x160/0x160 [ 126.123272] ? __lock_acquire+0x7fc/0x5020 [ 126.127893] ? lock_acquire+0x1e4/0x4f0 [ 126.132009] ? rtnetlink_rcv_msg+0x412/0xc30 [ 126.136587] ? lock_release+0x9f0/0x9f0 [ 126.140901] ? check_same_owner+0x340/0x340 [ 126.145592] ? mutex_trylock+0x2b0/0x2b0 [ 126.149869] ? __lock_acquire+0x7fc/0x5020 [ 126.154330] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 126.159870] ? refcount_sub_and_test_checked+0x21a/0x350 [ 126.165333] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 126.171054] ? rtnl_get_link+0x170/0x370 [ 126.175338] ? rtnl_dump_all+0x600/0x600 [ 126.179400] ? rcu_is_watching+0x8c/0x150 [ 126.183740] ? rtnl_link_unregister+0x390/0x390 [ 126.188499] rtnetlink_rcv_msg+0x46e/0xc30 [ 126.192846] ? rtnetlink_put_metrics+0x690/0x690 [ 126.197604] netlink_rcv_skb+0x172/0x440 [ 126.201743] ? rtnetlink_put_metrics+0x690/0x690 [ 126.206497] ? netlink_ack+0xbe0/0xbe0 [ 126.210384] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 126.215054] rtnetlink_rcv+0x1c/0x20 [ 126.218769] netlink_unicast+0x5a0/0x760 [ 126.222974] ? netlink_attachskb+0x9a0/0x9a0 [ 126.227396] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 126.232955] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 126.238239] netlink_sendmsg+0xa18/0xfc0 [ 126.242937] ? netlink_unicast+0x760/0x760 [ 126.247196] ? aa_sock_msg_perm.isra.13+0xba/0x160 [ 126.252230] ? apparmor_socket_sendmsg+0x29/0x30 [ 126.256996] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 126.262568] ? security_socket_sendmsg+0x94/0xc0 [ 126.267501] ? netlink_unicast+0x760/0x760 [ 126.271736] sock_sendmsg+0xd5/0x120 [ 126.275668] ___sys_sendmsg+0x7fd/0x930 [ 126.279648] ? copy_msghdr_from_user+0x580/0x580 [ 126.284594] ? lock_downgrade+0x8f0/0x8f0 [ 126.288802] ? __fget_light+0x2f7/0x440 [ 126.292898] ? fget_raw+0x20/0x20 [ 126.296642] ? __fd_install+0x2db/0x880 [ 126.300787] ? get_unused_fd_flags+0x1a0/0x1a0 [ 126.305375] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 126.311021] ? sockfd_lookup_light+0xc5/0x160 [ 126.315517] __sys_sendmsg+0x11d/0x290 [ 126.319433] ? __ia32_sys_shutdown+0x80/0x80 [ 126.323844] ? __x64_sys_futex+0x47f/0x6a0 [ 126.328077] ? do_syscall_64+0x9a/0x820 [ 126.332208] ? do_syscall_64+0x9a/0x820 [ 126.336204] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 126.341440] ? trace_hardirqs_off+0xb8/0x2b0 [ 126.345902] __x64_sys_sendmsg+0x78/0xb0 [ 126.350105] do_syscall_64+0x1b9/0x820 [ 126.354045] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 126.359742] ? syscall_return_slowpath+0x5e0/0x5e0 [ 126.364863] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 126.370023] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 126.375038] ? recalc_sigpending_tsk+0x180/0x180 [ 126.380116] ? kasan_check_write+0x14/0x20 [ 126.384588] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 126.389528] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 126.394882] RIP: 0033:0x457099 [ 126.398255] 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 [ 126.417448] RSP: 002b:00007fbaf84e6c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 126.425280] RAX: ffffffffffffffda RBX: 00007fbaf84e76d4 RCX: 0000000000457099 [ 126.432584] RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004 [ 126.439850] RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 [ 126.447116] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff [ 126.454469] R13: 00000000004d4890 R14: 00000000004c8ee5 R15: 0000000000000000 2018/09/04 17:29:47 executed programs: 114 2018/09/04 17:29:52 executed programs: 373