[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 23.494863] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 27.388051] random: sshd: uninitialized urandom read (32 bytes read) [ 27.730836] random: sshd: uninitialized urandom read (32 bytes read) [ 28.281788] random: sshd: uninitialized urandom read (32 bytes read) [ 28.461442] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.17' (ECDSA) to the list of known hosts. [ 34.038919] random: sshd: uninitialized urandom read (32 bytes read) 2018/09/02 13:05:58 parsed 1 programs [ 35.229297] random: cc1: uninitialized urandom read (8 bytes read) 2018/09/02 13:06:00 executed programs: 0 [ 36.384083] IPVS: ftp: loaded support on port[0] = 21 [ 36.604812] bridge0: port 1(bridge_slave_0) entered blocking state [ 36.611695] bridge0: port 1(bridge_slave_0) entered disabled state [ 36.620590] device bridge_slave_0 entered promiscuous mode [ 36.638261] bridge0: port 2(bridge_slave_1) entered blocking state [ 36.644655] bridge0: port 2(bridge_slave_1) entered disabled state [ 36.652256] device bridge_slave_1 entered promiscuous mode [ 36.668507] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 36.685010] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 36.730448] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 36.749596] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 36.817513] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 36.825060] team0: Port device team_slave_0 added [ 36.840892] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 36.848300] team0: Port device team_slave_1 added [ 36.864144] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 36.881737] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 36.899084] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 36.916714] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 37.048903] bridge0: port 2(bridge_slave_1) entered blocking state [ 37.055383] bridge0: port 2(bridge_slave_1) entered forwarding state [ 37.062216] bridge0: port 1(bridge_slave_0) entered blocking state [ 37.068719] bridge0: port 1(bridge_slave_0) entered forwarding state [ 37.528518] IPv6: ADDRCONF(NETDEV_UP): bond0: link is not ready [ 37.534921] 8021q: adding VLAN 0 to HW filter on device bond0 [ 37.564650] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 37.584080] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 37.633049] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 37.639567] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 37.647098] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 37.687098] 8021q: adding VLAN 0 to HW filter on device team0 [ 38.000440] [ 38.002086] ====================================================== [ 38.008393] WARNING: possible circular locking dependency detected [ 38.014700] 4.19.0-rc1+ #218 Not tainted [ 38.018748] ------------------------------------------------------ [ 38.025053] syz-executor0/4926 is trying to acquire lock: [ 38.030576] 0000000088b58ff8 ((wq_completion)bond_dev->name){+.+.}, at: flush_workqueue+0x2db/0x1e10 [ 38.039850] [ 38.039850] but task is already holding lock: [ 38.045844] 0000000088764206 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 [ 38.053781] [ 38.053781] which lock already depends on the new lock. [ 38.053781] [ 38.062199] [ 38.062199] the existing dependency chain (in reverse order) is: [ 38.069956] [ 38.069956] -> #2 (rtnl_mutex){+.+.}: [ 38.075257] __mutex_lock+0x171/0x1700 [ 38.079658] mutex_lock_nested+0x16/0x20 [ 38.084589] rtnl_lock+0x17/0x20 [ 38.088477] bond_netdev_notify_work+0x44/0xd0 [ 38.093574] process_one_work+0xc73/0x1aa0 [ 38.098320] worker_thread+0x189/0x13c0 [ 38.102932] kthread+0x35a/0x420 [ 38.106814] ret_from_fork+0x3a/0x50 [ 38.111036] [ 38.111036] -> #1 ((work_completion)(&(&nnw->work)->work)){+.+.}: [ 38.118836] process_one_work+0xc0b/0x1aa0 [ 38.123762] worker_thread+0x189/0x13c0 [ 38.128368] kthread+0x35a/0x420 [ 38.132257] ret_from_fork+0x3a/0x50 [ 38.136477] [ 38.136477] -> #0 ((wq_completion)bond_dev->name){+.+.}: [ 38.143561] lock_acquire+0x1e4/0x4f0 [ 38.147911] flush_workqueue+0x30a/0x1e10 [ 38.152572] drain_workqueue+0x2a9/0x640 [ 38.157153] destroy_workqueue+0xc6/0x9d0 [ 38.161954] __alloc_workqueue_key+0xef9/0x1190 [ 38.167137] bond_init+0x269/0x940 [ 38.171274] register_netdevice+0x337/0x1100 [ 38.176281] bond_newlink+0x49/0xa0 [ 38.180429] rtnl_newlink+0xef4/0x1d50 [ 38.184831] rtnetlink_rcv_msg+0x46e/0xc30 [ 38.189604] netlink_rcv_skb+0x172/0x440 [ 38.194180] rtnetlink_rcv+0x1c/0x20 [ 38.198404] netlink_unicast+0x5a0/0x760 [ 38.202977] netlink_sendmsg+0xa18/0xfc0 [ 38.207550] sock_sendmsg+0xd5/0x120 [ 38.211778] ___sys_sendmsg+0x7fd/0x930 [ 38.216267] __sys_sendmsg+0x11d/0x290 [ 38.220668] __x64_sys_sendmsg+0x78/0xb0 [ 38.225370] do_syscall_64+0x1b9/0x820 [ 38.229894] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.235599] [ 38.235599] other info that might help us debug this: [ 38.235599] [ 38.243730] Chain exists of: [ 38.243730] (wq_completion)bond_dev->name --> (work_completion)(&(&nnw->work)->work) --> rtnl_mutex [ 38.243730] [ 38.257537] Possible unsafe locking scenario: [ 38.257537] [ 38.263589] CPU0 CPU1 [ 38.268244] ---- ---- [ 38.272900] lock(rtnl_mutex); [ 38.276169] lock((work_completion)(&(&nnw->work)->work)); [ 38.284386] lock(rtnl_mutex); [ 38.290174] lock((wq_completion)bond_dev->name); [ 38.295092] [ 38.295092] *** DEADLOCK *** [ 38.295092] [ 38.301297] 1 lock held by syz-executor0/4926: [ 38.305888] #0: 0000000088764206 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 [ 38.314063] [ 38.314063] stack backtrace: [ 38.318688] CPU: 0 PID: 4926 Comm: syz-executor0 Not tainted 4.19.0-rc1+ #218 [ 38.325953] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.335298] Call Trace: [ 38.337908] dump_stack+0x1c9/0x2b4 [ 38.341616] ? dump_stack_print_info.cold.2+0x52/0x52 [ 38.346969] ? vprintk_func+0x81/0x117 [ 38.350878] print_circular_bug.isra.34.cold.55+0x1bd/0x27d [ 38.356583] ? save_trace+0xe0/0x290 [ 38.360403] __lock_acquire+0x3449/0x5020 [ 38.364552] ? mark_held_locks+0x160/0x160 [ 38.368791] ? mark_held_locks+0x160/0x160 [ 38.373127] ? __lock_is_held+0xb5/0x140 [ 38.377192] ? __account_cfs_rq_runtime+0x770/0x770 [ 38.382204] ? set_next_entity+0x2f0/0xa80 [ 38.386432] lock_acquire+0x1e4/0x4f0 [ 38.390227] ? flush_workqueue+0x2db/0x1e10 [ 38.394667] ? lock_release+0x9f0/0x9f0 [ 38.398637] ? lockdep_init_map+0x9/0x10 [ 38.402692] ? __init_waitqueue_head+0x9e/0x150 [ 38.407355] ? init_wait_entry+0x1c0/0x1c0 [ 38.411706] flush_workqueue+0x30a/0x1e10 [ 38.415972] ? flush_workqueue+0x2db/0x1e10 [ 38.420290] ? lock_acquire+0x1e4/0x4f0 [ 38.424256] ? drain_workqueue+0xa9/0x640 [ 38.428401] ? lock_release+0x9f0/0x9f0 [ 38.432371] ? check_same_owner+0x340/0x340 [ 38.436685] ? __queue_delayed_work+0x390/0x390 [ 38.441434] ? graph_lock+0x170/0x170 [ 38.445413] ? kasan_check_write+0x14/0x20 [ 38.449892] ? __mutex_lock+0x6d0/0x1700 [ 38.453975] ? drain_workqueue+0xa9/0x640 [ 38.458134] ? finish_task_switch+0x2ca/0x870 [ 38.462625] ? find_held_lock+0x36/0x1c0 [ 38.466701] ? lock_downgrade+0x8f0/0x8f0 [ 38.470850] ? __schedule+0x884/0x1df0 [ 38.474761] ? graph_lock+0x170/0x170 [ 38.478555] ? find_held_lock+0x36/0x1c0 [ 38.482613] ? kasan_check_write+0x14/0x20 [ 38.486844] ? __mutex_unlock_slowpath+0x197/0x8c0 [ 38.491806] ? wait_for_completion+0x8d0/0x8d0 [ 38.496496] ? do_raw_spin_unlock+0xa7/0x2f0 [ 38.500915] ? trace_hardirqs_on+0x2c0/0x2c0 [ 38.505334] drain_workqueue+0x2a9/0x640 [ 38.509392] ? drain_workqueue+0x2a9/0x640 [ 38.513624] ? flush_workqueue+0x1e10/0x1e10 [ 38.518131] ? save_stack+0xa9/0xd0 [ 38.521759] ? save_stack+0x43/0xd0 [ 38.525391] ? __kasan_slab_free+0x11a/0x170 [ 38.529809] ? kasan_slab_free+0xe/0x10 [ 38.533781] ? print_usage_bug+0xc0/0xc0 [ 38.538038] ? bond_init+0x269/0x940 [ 38.541754] ? register_netdevice+0x337/0x1100 [ 38.546431] ? bond_newlink+0x49/0xa0 [ 38.550341] ? rtnl_newlink+0xef4/0x1d50 [ 38.554507] ? rtnetlink_rcv_msg+0x46e/0xc30 [ 38.558919] ? netlink_rcv_skb+0x172/0x440 [ 38.563158] ? rtnetlink_rcv+0x1c/0x20 [ 38.567048] ? netlink_unicast+0x5a0/0x760 [ 38.571285] ? netlink_sendmsg+0xa18/0xfc0 [ 38.575516] ? sock_sendmsg+0xd5/0x120 [ 38.579404] destroy_workqueue+0xc6/0x9d0 [ 38.583559] ? kasan_check_write+0x14/0x20 [ 38.587817] ? wq_watchdog_timer_fn+0x830/0x830 [ 38.592503] ? mark_held_locks+0xc9/0x160 [ 38.596901] ? _raw_spin_unlock_irqrestore+0x63/0xc0 [ 38.602107] ? kfree+0x111/0x210 [ 38.605473] ? kfree+0x111/0x210 [ 38.608837] ? lockdep_hardirqs_on+0x421/0x5c0 [ 38.613455] ? trace_hardirqs_on+0xbd/0x2c0 [ 38.617777] ? init_rescuer.part.26+0x155/0x190 [ 38.622547] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 38.627653] ? __kasan_slab_free+0x131/0x170 [ 38.632261] ? init_rescuer.part.26+0x155/0x190 [ 38.637083] __alloc_workqueue_key+0xef9/0x1190 [ 38.641913] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.647450] ? workqueue_sysfs_register+0x3f0/0x3f0 [ 38.652556] ? put_dec+0xf0/0xf0 [ 38.655925] ? format_decode+0x1b1/0xaf0 [ 38.660076] ? set_precision+0xe0/0xe0 [ 38.663976] ? simple_strtoll+0xa0/0xa0 [ 38.667987] ? graph_lock+0x170/0x170 [ 38.671801] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 38.677335] ? vsnprintf+0x20d/0x1b60 [ 38.681132] ? find_held_lock+0x36/0x1c0 [ 38.685191] ? lock_downgrade+0x8f0/0x8f0 [ 38.689609] ? kasan_check_read+0x11/0x20 [ 38.693760] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 38.698430] bond_init+0x269/0x940 [ 38.701982] ? __dev_get_by_name+0x170/0x170 [ 38.706403] ? bond_arp_rcv+0x11c0/0x11c0 [ 38.710561] ? check_same_owner+0x340/0x340 [ 38.714914] ? rcu_note_context_switch+0x680/0x680 [ 38.719849] ? bond_arp_rcv+0x11c0/0x11c0 [ 38.724205] register_netdevice+0x337/0x1100 [ 38.728624] ? netdev_change_features+0x110/0x110 [ 38.733471] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.739091] ? ns_capable_common+0x13f/0x170 [ 38.743631] ? ns_capable+0x22/0x30 [ 38.747258] bond_newlink+0x49/0xa0 [ 38.751002] ? bond_changelink+0x2360/0x2360 [ 38.755542] rtnl_newlink+0xef4/0x1d50 [ 38.759431] ? rtnl_link_unregister+0x390/0x390 [ 38.764376] ? print_usage_bug+0xc0/0xc0 [ 38.768447] ? __lock_acquire+0x7fc/0x5020 [ 38.772691] ? print_usage_bug+0xc0/0xc0 [ 38.776753] ? graph_lock+0x170/0x170 [ 38.780750] ? print_usage_bug+0xc0/0xc0 [ 38.784805] ? mark_held_locks+0x160/0x160 [ 38.789042] ? __lock_acquire+0x7fc/0x5020 [ 38.793274] ? lock_acquire+0x1e4/0x4f0 [ 38.797247] ? rtnetlink_rcv_msg+0x412/0xc30 [ 38.801651] ? lock_release+0x9f0/0x9f0 [ 38.805632] ? check_same_owner+0x340/0x340 [ 38.809991] ? mutex_trylock+0x2b0/0x2b0 [ 38.814064] ? __lock_acquire+0x7fc/0x5020 [ 38.818301] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.823837] ? refcount_sub_and_test_checked+0x21a/0x350 [ 38.829333] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 38.834901] ? rtnl_get_link+0x170/0x370 [ 38.838981] ? rtnl_dump_all+0x600/0x600 [ 38.843059] ? rcu_is_watching+0x8c/0x150 [ 38.847204] ? rtnl_link_unregister+0x390/0x390 [ 38.851908] rtnetlink_rcv_msg+0x46e/0xc30 [ 38.856289] ? rtnetlink_put_metrics+0x690/0x690 [ 38.861068] netlink_rcv_skb+0x172/0x440 [ 38.865129] ? rtnetlink_put_metrics+0x690/0x690 [ 38.869911] ? netlink_ack+0xbe0/0xbe0 [ 38.873808] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 38.878475] rtnetlink_rcv+0x1c/0x20 [ 38.882184] netlink_unicast+0x5a0/0x760 [ 38.886241] ? netlink_attachskb+0x9a0/0x9a0 [ 38.890645] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.896181] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 38.901193] netlink_sendmsg+0xa18/0xfc0 [ 38.905249] ? netlink_unicast+0x760/0x760 [ 38.909482] ? aa_sock_msg_perm.isra.13+0xba/0x160 [ 38.914407] ? apparmor_socket_sendmsg+0x29/0x30 [ 38.919162] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.924705] ? security_socket_sendmsg+0x94/0xc0 [ 38.929493] ? netlink_unicast+0x760/0x760 [ 38.933731] sock_sendmsg+0xd5/0x120 [ 38.937595] ___sys_sendmsg+0x7fd/0x930 [ 38.941570] ? copy_msghdr_from_user+0x580/0x580 [ 38.946323] ? lock_downgrade+0x8f0/0x8f0 [ 38.950558] ? __fget_light+0x2f7/0x440 [ 38.954530] ? fget_raw+0x20/0x20 [ 38.957993] ? __fd_install+0x2db/0x880 [ 38.961992] ? get_unused_fd_flags+0x1a0/0x1a0 [ 38.966589] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 38.972124] ? sockfd_lookup_light+0xc5/0x160 [ 38.976616] __sys_sendmsg+0x11d/0x290 [ 38.980819] ? __ia32_sys_shutdown+0x80/0x80 [ 38.985230] ? __x64_sys_futex+0x47f/0x6a0 [ 38.989463] ? do_syscall_64+0x9a/0x820 [ 38.993441] ? do_syscall_64+0x9a/0x820 [ 38.997570] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 39.002667] ? trace_hardirqs_off+0xb8/0x2b0 [ 39.007069] __x64_sys_sendmsg+0x78/0xb0 [ 39.011126] do_syscall_64+0x1b9/0x820 [ 39.015010] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 39.020366] ? syscall_return_slowpath+0x5e0/0x5e0 [ 39.025295] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 39.030305] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 39.035442] ? recalc_sigpending_tsk+0x180/0x180 [ 39.040199] ? kasan_check_write+0x14/0x20 [ 39.044440] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.049290] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 39.054490] RIP: 0033:0x457099 [ 39.057821] 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 [ 39.076720] RSP: 002b:00007fb23b292c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 39.084424] RAX: ffffffffffffffda RBX: 00007fb23b2936d4 RCX: 0000000000457099 [ 39.091842] RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004 [ 39.099139] RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 [ 39.106403] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff [ 39.113678] R13: 00000000004d4890 R14: 00000000004c8ee5 R15: 0000000000000000 2018/09/02 13:06:05 executed programs: 120 2018/09/02 13:06:10 executed programs: 380